KVM: Don't pre-reserve xarray entries when storing empty/NULL attributesgrafted

Skip the xarray reservation loop when clearing all memory attributes, as
storing NULL only erases the entry and never needs to allocate, so no
reservation (and no cleanup of a failed one) is required in that case.

Suggested-by: Sean Christopherson <seanjc@google.com>
Cc: David Ballesteros <davimaba.v@proton.me>
Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com
[sean: split to separate patch]
Signed-off-by: Sean Christopherson <seanjc@google.com>

17 files changed, 6605 insertions, 0 deletions

diff --git a/fs/hpfs/Kconfig b/fs/hpfs/Kconfig
new file mode 100644
index 000000000..ac1e9318e
--- /dev/null
+++ b/fs/hpfs/Kconfig
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config HPFS_FS
+	tristate "OS/2 HPFS file system support"
+	depends on BLOCK
+	select BUFFER_HEAD
+	select FS_IOMAP
+	help
+	  OS/2 is IBM's operating system for PC's, the same as Warp, and HPFS
+	  is the file system used for organizing files on OS/2 hard disk
+	  partitions. Say Y if you want to be able to read files from and
+	  write files to an OS/2 HPFS partition on your hard drive. OS/2
+	  floppies however are in regular MSDOS format, so you don't need this
+	  option in order to be able to read them. Read
+	  <file:Documentation/filesystems/hpfs.rst>.
+
+	  To compile this file system support as a module, choose M here: the
+	  module will be called hpfs.  If unsure, say N.
diff --git a/fs/hpfs/Makefile b/fs/hpfs/Makefile
new file mode 100644
index 000000000..153c17382
--- /dev/null
+++ b/fs/hpfs/Makefile
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the Linux hpfs filesystem routines.
+#
+
+obj-$(CONFIG_HPFS_FS) += hpfs.o
+
+hpfs-objs := alloc.o anode.o buffer.o dentry.o dir.o dnode.o ea.o file.o \
+	     inode.o map.o name.o namei.o super.o
diff --git a/fs/hpfs/alloc.c b/fs/hpfs/alloc.c
new file mode 100644
index 000000000..f51503726
--- /dev/null
+++ b/fs/hpfs/alloc.c
@@ -0,0 +1,582 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/hpfs/alloc.c
+ *
+ *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
+ *
+ *  HPFS bitmap operations
+ */
+
+#include "hpfs_fn.h"
+
+static void hpfs_claim_alloc(struct super_block *s, secno sec)
+{
+	struct hpfs_sb_info *sbi = hpfs_sb(s);
+	if (sbi->sb_n_free != (unsigned)-1) {
+		if (unlikely(!sbi->sb_n_free)) {
+			hpfs_error(s, "free count underflow, allocating sector %08x", sec);
+			sbi->sb_n_free = -1;
+			return;
+		}
+		sbi->sb_n_free--;
+	}
+}
+
+static void hpfs_claim_free(struct super_block *s, secno sec)
+{
+	struct hpfs_sb_info *sbi = hpfs_sb(s);
+	if (sbi->sb_n_free != (unsigned)-1) {
+		if (unlikely(sbi->sb_n_free >= sbi->sb_fs_size)) {
+			hpfs_error(s, "free count overflow, freeing sector %08x", sec);
+			sbi->sb_n_free = -1;
+			return;
+		}
+		sbi->sb_n_free++;
+	}
+}
+
+static void hpfs_claim_dirband_alloc(struct super_block *s, secno sec)
+{
+	struct hpfs_sb_info *sbi = hpfs_sb(s);
+	if (sbi->sb_n_free_dnodes != (unsigned)-1) {
+		if (unlikely(!sbi->sb_n_free_dnodes)) {
+			hpfs_error(s, "dirband free count underflow, allocating sector %08x", sec);
+			sbi->sb_n_free_dnodes = -1;
+			return;
+		}
+		sbi->sb_n_free_dnodes--;
+	}
+}
+
+static void hpfs_claim_dirband_free(struct super_block *s, secno sec)
+{
+	struct hpfs_sb_info *sbi = hpfs_sb(s);
+	if (sbi->sb_n_free_dnodes != (unsigned)-1) {
+		if (unlikely(sbi->sb_n_free_dnodes >= sbi->sb_dirband_size / 4)) {
+			hpfs_error(s, "dirband free count overflow, freeing sector %08x", sec);
+			sbi->sb_n_free_dnodes = -1;
+			return;
+		}
+		sbi->sb_n_free_dnodes++;
+	}
+}
+
+/*
+ * Check if a sector is allocated in bitmap
+ * This is really slow. Turned on only if chk==2
+ */
+
+static int chk_if_allocated(struct super_block *s, secno sec, char *msg)
+{
+	struct quad_buffer_head qbh;
+	__le32 *bmp;
+	if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "chk"))) goto fail;
+	if ((le32_to_cpu(bmp[(sec & 0x3fff) >> 5]) >> (sec & 0x1f)) & 1) {
+		hpfs_error(s, "sector '%s' - %08x not allocated in bitmap", msg, sec);
+		goto fail1;
+	}
+	hpfs_brelse4(&qbh);
+	if (sec >= hpfs_sb(s)->sb_dirband_start && sec < hpfs_sb(s)->sb_dirband_start + hpfs_sb(s)->sb_dirband_size) {
+		unsigned ssec = (sec - hpfs_sb(s)->sb_dirband_start) / 4;
+		if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) goto fail;
+		if ((le32_to_cpu(bmp[ssec >> 5]) >> (ssec & 0x1f)) & 1) {
+			hpfs_error(s, "sector '%s' - %08x not allocated in directory bitmap", msg, sec);
+			goto fail1;
+		}
+		hpfs_brelse4(&qbh);
+	}
+	return 0;
+	fail1:
+	hpfs_brelse4(&qbh);
+	fail:
+	return 1;
+}
+
+/*
+ * Check if sector(s) have proper number and additionally check if they're
+ * allocated in bitmap.
+ */
+	
+int hpfs_chk_sectors(struct super_block *s, secno start, int len, char *msg)
+{
+	if (start + len < start || start < 0x12 ||
+	    start + len > hpfs_sb(s)->sb_fs_size) {
+	    	hpfs_error(s, "sector(s) '%s' badly placed at %08x", msg, start);
+		return 1;
+	}
+	if (hpfs_sb(s)->sb_chk>=2) {
+		int i;
+		for (i = 0; i < len; i++)
+			if (chk_if_allocated(s, start + i, msg)) return 1;
+	}
+	return 0;
+}
+
+static secno alloc_in_bmp(struct super_block *s, secno near, unsigned n, unsigned forward)
+{
+	struct quad_buffer_head qbh;
+	__le32 *bmp;
+	unsigned bs = near & ~0x3fff;
+	unsigned nr = (near & 0x3fff) & ~(n - 1);
+	/*unsigned mnr;*/
+	unsigned i, q;
+	int a, b;
+	secno ret = 0;
+	if (n != 1 && n != 4) {
+		hpfs_error(s, "Bad allocation size: %d", n);
+		return 0;
+	}
+	if (bs != ~0x3fff) {
+		if (!(bmp = hpfs_map_bitmap(s, near >> 14, &qbh, "aib"))) goto uls;
+	} else {
+		if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) goto uls;
+	}
+	if (!tstbits(bmp, nr, n + forward)) {
+		ret = bs + nr;
+		goto rt;
+	}
+	q = nr + n; b = 0;
+	while ((a = tstbits(bmp, q, n + forward)) != 0) {
+		q += a;
+		if (n != 1) q = ((q-1)&~(n-1))+n;
+		if (!b) {
+			if (q>>5 != nr>>5) {
+				b = 1;
+				q = nr & 0x1f;
+			}
+		} else if (q > nr) break;
+	}
+	if (!a) {
+		ret = bs + q;
+		goto rt;
+	}
+	nr >>= 5;
+	/*for (i = nr + 1; i != nr; i++, i &= 0x1ff) */
+	i = nr;
+	do {
+		if (!le32_to_cpu(bmp[i])) goto cont;
+		if (n + forward >= 0x3f && le32_to_cpu(bmp[i]) != 0xffffffff) goto cont;
+		q = i<<5;
+		if (i > 0) {
+			unsigned k = le32_to_cpu(bmp[i-1]);
+			while (k & 0x80000000) {
+				q--; k <<= 1;
+			}
+		}
+		if (n != 1) q = ((q-1)&~(n-1))+n;
+		while ((a = tstbits(bmp, q, n + forward)) != 0) {
+			q += a;
+			if (n != 1) q = ((q-1)&~(n-1))+n;
+			if (q>>5 > i) break;
+		}
+		if (!a) {
+			ret = bs + q;
+			goto rt;
+		}
+		cont:
+		i++, i &= 0x1ff;
+	} while (i != nr);
+	rt:
+	if (ret) {
+		if (hpfs_sb(s)->sb_chk && ((ret >> 14) != (bs >> 14) || (le32_to_cpu(bmp[(ret & 0x3fff) >> 5]) | ~(((1 << n) - 1) << (ret & 0x1f))) != 0xffffffff)) {
+			hpfs_error(s, "Allocation doesn't work! Wanted %d, allocated at %08x", n, ret);
+			ret = 0;
+			goto b;
+		}
+		bmp[(ret & 0x3fff) >> 5] &= cpu_to_le32(~(((1 << n) - 1) << (ret & 0x1f)));
+		hpfs_mark_4buffers_dirty(&qbh);
+	}
+	b:
+	hpfs_brelse4(&qbh);
+	uls:
+	return ret;
+}
+
+/*
+ * Allocation strategy:	1) search place near the sector specified
+ *			2) search bitmap where free sectors last found
+ *			3) search all bitmaps
+ *			4) search all bitmaps ignoring number of pre-allocated
+ *				sectors
+ */
+
+secno hpfs_alloc_sector(struct super_block *s, secno near, unsigned n, int forward)
+{
+	secno sec;
+	int i;
+	unsigned n_bmps;
+	struct hpfs_sb_info *sbi = hpfs_sb(s);
+	int f_p = 0;
+	int near_bmp;
+	if (forward < 0) {
+		forward = -forward;
+		f_p = 1;
+	}
+	n_bmps = (sbi->sb_fs_size + 0x4000 - 1) >> 14;
+	if (near && near < sbi->sb_fs_size) {
+		if ((sec = alloc_in_bmp(s, near, n, f_p ? forward : forward/4))) goto ret;
+		near_bmp = near >> 14;
+	} else near_bmp = n_bmps / 2;
+	/*
+	if (b != -1) {
+		if ((sec = alloc_in_bmp(s, b<<14, n, f_p ? forward : forward/2))) {
+			b &= 0x0fffffff;
+			goto ret;
+		}
+		if (b > 0x10000000) if ((sec = alloc_in_bmp(s, (b&0xfffffff)<<14, n, f_p ? forward : 0))) goto ret;
+	*/
+	if (!f_p) if (forward > sbi->sb_max_fwd_alloc) forward = sbi->sb_max_fwd_alloc;
+	less_fwd:
+	for (i = 0; i < n_bmps; i++) {
+		if (near_bmp+i < n_bmps && ((sec = alloc_in_bmp(s, (near_bmp+i) << 14, n, forward)))) {
+			sbi->sb_c_bitmap = near_bmp+i;
+			goto ret;
+		}	
+		if (!forward) {
+			if (near_bmp-i-1 >= 0 && ((sec = alloc_in_bmp(s, (near_bmp-i-1) << 14, n, forward)))) {
+				sbi->sb_c_bitmap = near_bmp-i-1;
+				goto ret;
+			}
+		} else {
+			if (near_bmp+i >= n_bmps && ((sec = alloc_in_bmp(s, (near_bmp+i-n_bmps) << 14, n, forward)))) {
+				sbi->sb_c_bitmap = near_bmp+i-n_bmps;
+				goto ret;
+			}
+		}
+		if (i == 1 && sbi->sb_c_bitmap != -1 && ((sec = alloc_in_bmp(s, (sbi->sb_c_bitmap) << 14, n, forward)))) {
+			goto ret;
+		}
+	}
+	if (!f_p) {
+		if (forward) {
+			sbi->sb_max_fwd_alloc = forward * 3 / 4;
+			forward /= 2;
+			goto less_fwd;
+		}
+	}
+	sec = 0;
+	ret:
+	if (sec) {
+		i = 0;
+		do
+			hpfs_claim_alloc(s, sec + i);
+		while (unlikely(++i < n));
+	}
+	if (sec && f_p) {
+		for (i = 0; i < forward; i++) {
+			if (!hpfs_alloc_if_possible(s, sec + n + i)) {
+				hpfs_error(s, "Prealloc doesn't work! Wanted %d, allocated at %08x, can't allocate %d", forward, sec, i);
+				sec = 0;
+				break;
+			}
+		}
+	}
+	return sec;
+}
+
+static secno alloc_in_dirband(struct super_block *s, secno near)
+{
+	unsigned nr = near;
+	secno sec;
+	struct hpfs_sb_info *sbi = hpfs_sb(s);
+	if (nr < sbi->sb_dirband_start)
+		nr = sbi->sb_dirband_start;
+	if (nr >= sbi->sb_dirband_start + sbi->sb_dirband_size)
+		nr = sbi->sb_dirband_start + sbi->sb_dirband_size - 4;
+	nr -= sbi->sb_dirband_start;
+	nr >>= 2;
+	sec = alloc_in_bmp(s, (~0x3fff) | nr, 1, 0);
+	if (!sec) return 0;
+	hpfs_claim_dirband_alloc(s, sec);
+	return ((sec & 0x3fff) << 2) + sbi->sb_dirband_start;
+}
+
+/* Alloc sector if it's free */
+
+int hpfs_alloc_if_possible(struct super_block *s, secno sec)
+{
+	struct quad_buffer_head qbh;
+	__le32 *bmp;
+	if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "aip"))) goto end;
+	if (le32_to_cpu(bmp[(sec & 0x3fff) >> 5]) & (1 << (sec & 0x1f))) {
+		bmp[(sec & 0x3fff) >> 5] &= cpu_to_le32(~(1 << (sec & 0x1f)));
+		hpfs_mark_4buffers_dirty(&qbh);
+		hpfs_brelse4(&qbh);
+		hpfs_claim_alloc(s, sec);
+		return 1;
+	}
+	hpfs_brelse4(&qbh);
+	end:
+	return 0;
+}
+
+/* Free sectors in bitmaps */
+
+void hpfs_free_sectors(struct super_block *s, secno sec, unsigned n)
+{
+	struct quad_buffer_head qbh;
+	__le32 *bmp;
+	struct hpfs_sb_info *sbi = hpfs_sb(s);
+	/*pr_info("2 - ");*/
+	if (!n) return;
+	if (sec < 0x12) {
+		hpfs_error(s, "Trying to free reserved sector %08x", sec);
+		return;
+	}
+	sbi->sb_max_fwd_alloc += n > 0xffff ? 0xffff : n;
+	if (sbi->sb_max_fwd_alloc > 0xffffff) sbi->sb_max_fwd_alloc = 0xffffff;
+	new_map:
+	if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "free"))) {
+		return;
+	}	
+	new_tst:
+	if ((le32_to_cpu(bmp[(sec & 0x3fff) >> 5]) >> (sec & 0x1f) & 1)) {
+		hpfs_error(s, "sector %08x not allocated", sec);
+		hpfs_brelse4(&qbh);
+		return;
+	}
+	bmp[(sec & 0x3fff) >> 5] |= cpu_to_le32(1 << (sec & 0x1f));
+	hpfs_claim_free(s, sec);
+	if (!--n) {
+		hpfs_mark_4buffers_dirty(&qbh);
+		hpfs_brelse4(&qbh);
+		return;
+	}	
+	if (!(++sec & 0x3fff)) {
+		hpfs_mark_4buffers_dirty(&qbh);
+		hpfs_brelse4(&qbh);
+		goto new_map;
+	}
+	goto new_tst;
+}
+
+/*
+ * Check if there are at least n free dnodes on the filesystem.
+ * Called before adding to dnode. If we run out of space while
+ * splitting dnodes, it would corrupt dnode tree.
+ */
+
+int hpfs_check_free_dnodes(struct super_block *s, int n)
+{
+	int n_bmps = (hpfs_sb(s)->sb_fs_size + 0x4000 - 1) >> 14;
+	int b = hpfs_sb(s)->sb_c_bitmap & 0x0fffffff;
+	int i, j;
+	__le32 *bmp;
+	struct quad_buffer_head qbh;
+	if ((bmp = hpfs_map_dnode_bitmap(s, &qbh))) {
+		for (j = 0; j < 512; j++) {
+			unsigned k;
+			if (!le32_to_cpu(bmp[j])) continue;
+			for (k = le32_to_cpu(bmp[j]); k; k >>= 1) if (k & 1) if (!--n) {
+				hpfs_brelse4(&qbh);
+				return 0;
+			}
+		}
+		hpfs_brelse4(&qbh);
+	}
+	i = 0;
+	if (hpfs_sb(s)->sb_c_bitmap != -1) {
+		bmp = hpfs_map_bitmap(s, b, &qbh, "chkdn1");
+		goto chk_bmp;
+	}
+	chk_next:
+	if (i == b) i++;
+	if (i >= n_bmps) return 1;
+	bmp = hpfs_map_bitmap(s, i, &qbh, "chkdn2");
+	chk_bmp:
+	if (bmp) {
+		for (j = 0; j < 512; j++) {
+			u32 k;
+			if (!le32_to_cpu(bmp[j])) continue;
+			for (k = 0xf; k; k <<= 4)
+				if ((le32_to_cpu(bmp[j]) & k) == k) {
+					if (!--n) {
+						hpfs_brelse4(&qbh);
+						return 0;
+					}
+				}
+		}
+		hpfs_brelse4(&qbh);
+	}
+	i++;
+	goto chk_next;
+}
+
+void hpfs_free_dnode(struct super_block *s, dnode_secno dno)
+{
+	if (hpfs_sb(s)->sb_chk) if (dno & 3) {
+		hpfs_error(s, "hpfs_free_dnode: dnode %08x not aligned", dno);
+		return;
+	}
+	if (dno < hpfs_sb(s)->sb_dirband_start ||
+	    dno >= hpfs_sb(s)->sb_dirband_start + hpfs_sb(s)->sb_dirband_size) {
+		hpfs_free_sectors(s, dno, 4);
+	} else {
+		struct quad_buffer_head qbh;
+		__le32 *bmp;
+		unsigned ssec = (dno - hpfs_sb(s)->sb_dirband_start) / 4;
+		if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) {
+			return;
+		}
+		bmp[ssec >> 5] |= cpu_to_le32(1 << (ssec & 0x1f));
+		hpfs_mark_4buffers_dirty(&qbh);
+		hpfs_brelse4(&qbh);
+		hpfs_claim_dirband_free(s, dno);
+	}
+}
+
+struct dnode *hpfs_alloc_dnode(struct super_block *s, secno near,
+			 dnode_secno *dno, struct quad_buffer_head *qbh)
+{
+	struct dnode *d;
+	if (hpfs_get_free_dnodes(s) > FREE_DNODES_ADD) {
+		if (!(*dno = alloc_in_dirband(s, near)))
+			if (!(*dno = hpfs_alloc_sector(s, near, 4, 0))) return NULL;
+	} else {
+		if (!(*dno = hpfs_alloc_sector(s, near, 4, 0)))
+			if (!(*dno = alloc_in_dirband(s, near))) return NULL;
+	}
+	if (!(d = hpfs_get_4sectors(s, *dno, qbh))) {
+		hpfs_free_dnode(s, *dno);
+		return NULL;
+	}
+	memset(d, 0, 2048);
+	d->magic = cpu_to_le32(DNODE_MAGIC);
+	d->first_free = cpu_to_le32(52);
+	d->dirent[0] = 32;
+	d->dirent[2] = 8;
+	d->dirent[30] = 1;
+	d->dirent[31] = 255;
+	d->self = cpu_to_le32(*dno);
+	return d;
+}
+
+struct fnode *hpfs_alloc_fnode(struct super_block *s, secno near, fnode_secno *fno,
+			  struct buffer_head **bh)
+{
+	struct fnode *f;
+	if (!(*fno = hpfs_alloc_sector(s, near, 1, FNODE_ALLOC_FWD))) return NULL;
+	if (!(f = hpfs_get_sector(s, *fno, bh))) {
+		hpfs_free_sectors(s, *fno, 1);
+		return NULL;
+	}	
+	memset(f, 0, 512);
+	f->magic = cpu_to_le32(FNODE_MAGIC);
+	f->ea_offs = cpu_to_le16(0xc4);
+	f->btree.n_free_nodes = 8;
+	f->btree.first_free = cpu_to_le16(8);
+	return f;
+}
+
+struct anode *hpfs_alloc_anode(struct super_block *s, secno near, anode_secno *ano,
+			  struct buffer_head **bh)
+{
+	struct anode *a;
+	if (!(*ano = hpfs_alloc_sector(s, near, 1, ANODE_ALLOC_FWD))) return NULL;
+	if (!(a = hpfs_get_sector(s, *ano, bh))) {
+		hpfs_free_sectors(s, *ano, 1);
+		return NULL;
+	}
+	memset(a, 0, 512);
+	a->magic = cpu_to_le32(ANODE_MAGIC);
+	a->self = cpu_to_le32(*ano);
+	a->btree.n_free_nodes = 40;
+	a->btree.n_used_nodes = 0;
+	a->btree.first_free = cpu_to_le16(8);
+	return a;
+}
+
+static unsigned find_run(__le32 *bmp, unsigned *idx)
+{
+	unsigned len;
+	while (tstbits(bmp, *idx, 1)) {
+		(*idx)++;
+		if (unlikely(*idx >= 0x4000))
+			return 0;
+	}
+	len = 1;
+	while (!tstbits(bmp, *idx + len, 1))
+		len++;
+	return len;
+}
+
+static int do_trim(struct super_block *s, secno start, unsigned len, secno limit_start, secno limit_end, unsigned minlen, unsigned *result)
+{
+	int err;
+	secno end;
+	if (fatal_signal_pending(current))
+		return -EINTR;
+	end = start + len;
+	if (start < limit_start)
+		start = limit_start;
+	if (end > limit_end)
+		end = limit_end;
+	if (start >= end)
+		return 0;
+	if (end - start < minlen)
+		return 0;
+	err = sb_issue_discard(s, start, end - start, GFP_NOFS, 0);
+	if (err)
+		return err;
+	*result += end - start;
+	return 0;
+}
+
+int hpfs_trim_fs(struct super_block *s, u64 start, u64 end, u64 minlen, unsigned *result)
+{
+	int err = 0;
+	struct hpfs_sb_info *sbi = hpfs_sb(s);
+	unsigned idx, len, start_bmp, end_bmp;
+	__le32 *bmp;
+	struct quad_buffer_head qbh;
+
+	*result = 0;
+	if (!end || end > sbi->sb_fs_size)
+		end = sbi->sb_fs_size;
+	if (start >= sbi->sb_fs_size)
+		return 0;
+	if (minlen > 0x4000)
+		return 0;
+	if (start < sbi->sb_dirband_start + sbi->sb_dirband_size && end > sbi->sb_dirband_start) {
+		hpfs_lock(s);
+		if (sb_rdonly(s)) {
+			err = -EROFS;
+			goto unlock_1;
+		}
+		if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) {
+			err = -EIO;
+			goto unlock_1;
+		}
+		idx = 0;
+		while ((len = find_run(bmp, &idx)) && !err) {
+			err = do_trim(s, sbi->sb_dirband_start + idx * 4, len * 4, start, end, minlen, result);
+			idx += len;
+		}
+		hpfs_brelse4(&qbh);
+unlock_1:
+		hpfs_unlock(s);
+	}
+	start_bmp = start >> 14;
+	end_bmp = (end + 0x3fff) >> 14;
+	while (start_bmp < end_bmp && !err) {
+		hpfs_lock(s);
+		if (sb_rdonly(s)) {
+			err = -EROFS;
+			goto unlock_2;
+		}
+		if (!(bmp = hpfs_map_bitmap(s, start_bmp, &qbh, "trim"))) {
+			err = -EIO;
+			goto unlock_2;
+		}
+		idx = 0;
+		while ((len = find_run(bmp, &idx)) && !err) {
+			err = do_trim(s, (start_bmp << 14) + idx, len, start, end, minlen, result);
+			idx += len;
+		}
+		hpfs_brelse4(&qbh);
+unlock_2:
+		hpfs_unlock(s);
+		start_bmp++;
+	}
+	return err;
+}
diff --git a/fs/hpfs/anode.c b/fs/hpfs/anode.c
new file mode 100644
index 000000000..a4f5321ea
--- /dev/null
+++ b/fs/hpfs/anode.c
@@ -0,0 +1,498 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/hpfs/anode.c
+ *
+ *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
+ *
+ *  handling HPFS anode tree that contains file allocation info
+ */
+
+#include "hpfs_fn.h"
+
+/* Find a sector in allocation tree */
+
+secno hpfs_bplus_lookup(struct super_block *s, struct inode *inode,
+		   struct bplus_header *btree, unsigned sec,
+		   struct buffer_head *bh)
+{
+	anode_secno a = -1;
+	struct anode *anode;
+	int i;
+	int c1, c2 = 0;
+	go_down:
+	if (hpfs_sb(s)->sb_chk) if (hpfs_stop_cycles(s, a, &c1, &c2, "hpfs_bplus_lookup")) return -1;
+	if (bp_internal(btree)) {
+		for (i = 0; i < btree->n_used_nodes; i++)
+			if (le32_to_cpu(btree->u.internal[i].file_secno) > sec) {
+				a = le32_to_cpu(btree->u.internal[i].down);
+				brelse(bh);
+				if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
+				btree = GET_BTREE_PTR(&anode->btree);
+				goto go_down;
+			}
+		hpfs_error(s, "sector %08x not found in internal anode %08x", sec, a);
+		brelse(bh);
+		return -1;
+	}
+	for (i = 0; i < btree->n_used_nodes; i++)
+		if (le32_to_cpu(btree->u.external[i].file_secno) <= sec &&
+		    le32_to_cpu(btree->u.external[i].file_secno) + le32_to_cpu(btree->u.external[i].length) > sec) {
+			a = le32_to_cpu(btree->u.external[i].disk_secno) + sec - le32_to_cpu(btree->u.external[i].file_secno);
+			if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, a, 1, "data")) {
+				brelse(bh);
+				return -1;
+			}
+			if (inode) {
+				struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
+				hpfs_inode->i_file_sec = le32_to_cpu(btree->u.external[i].file_secno);
+				hpfs_inode->i_disk_sec = le32_to_cpu(btree->u.external[i].disk_secno);
+				hpfs_inode->i_n_secs = le32_to_cpu(btree->u.external[i].length);
+			}
+			brelse(bh);
+			return a;
+		}
+	hpfs_error(s, "sector %08x not found in external anode %08x", sec, a);
+	brelse(bh);
+	return -1;
+}
+
+/* Add a sector to tree */
+
+secno hpfs_add_sector_to_btree(struct super_block *s, secno node, int fnod, unsigned fsecno)
+{
+	struct bplus_header *btree;
+	struct anode *anode = NULL, *ranode = NULL;
+	struct fnode *fnode;
+	anode_secno a, na = -1, ra, up = -1;
+	secno se;
+	struct buffer_head *bh, *bh1, *bh2;
+	int n;
+	unsigned fs;
+	int c1, c2 = 0;
+
+	if (fnod) {
+		if (!(fnode = hpfs_map_fnode(s, node, &bh))) return -1;
+		btree = GET_BTREE_PTR(&fnode->btree);
+	} else {
+		if (!(anode = hpfs_map_anode(s, node, &bh))) return -1;
+		btree = GET_BTREE_PTR(&anode->btree);
+	}
+	a = node;
+	go_down:
+	if ((n = btree->n_used_nodes - 1) < -!!fnod) {
+		hpfs_error(s, "anode %08x has no entries", a);
+		brelse(bh);
+		return -1;
+	}
+	if (bp_internal(btree)) {
+		a = le32_to_cpu(btree->u.internal[n].down);
+		btree->u.internal[n].file_secno = cpu_to_le32(-1);
+		mark_buffer_dirty(bh);
+		brelse(bh);
+		if (hpfs_sb(s)->sb_chk)
+			if (hpfs_stop_cycles(s, a, &c1, &c2, "hpfs_add_sector_to_btree #1")) return -1;
+		if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
+		btree = GET_BTREE_PTR(&anode->btree);
+		goto go_down;
+	}
+	if (n >= 0) {
+		if (le32_to_cpu(btree->u.external[n].file_secno) + le32_to_cpu(btree->u.external[n].length) != fsecno) {
+			hpfs_error(s, "allocated size %08x, trying to add sector %08x, %cnode %08x",
+				le32_to_cpu(btree->u.external[n].file_secno) + le32_to_cpu(btree->u.external[n].length), fsecno,
+				fnod?'f':'a', node);
+			brelse(bh);
+			return -1;
+		}
+		if (hpfs_alloc_if_possible(s, se = le32_to_cpu(btree->u.external[n].disk_secno) + le32_to_cpu(btree->u.external[n].length))) {
+			le32_add_cpu(&btree->u.external[n].length, 1);
+			mark_buffer_dirty(bh);
+			brelse(bh);
+			return se;
+		}
+	} else {
+		if (fsecno) {
+			hpfs_error(s, "empty file %08x, trying to add sector %08x", node, fsecno);
+			brelse(bh);
+			return -1;
+		}
+		se = !fnod ? node : (node + 16384) & ~16383;
+	}	
+	if (!(se = hpfs_alloc_sector(s, se, 1, fsecno*ALLOC_M>ALLOC_FWD_MAX ? ALLOC_FWD_MAX : fsecno*ALLOC_M<ALLOC_FWD_MIN ? ALLOC_FWD_MIN : fsecno*ALLOC_M))) {
+		brelse(bh);
+		return -1;
+	}
+	fs = n < 0 ? 0 : le32_to_cpu(btree->u.external[n].file_secno) + le32_to_cpu(btree->u.external[n].length);
+	if (!btree->n_free_nodes) {
+		up = a != node ? le32_to_cpu(anode->up) : -1;
+		if (!(anode = hpfs_alloc_anode(s, a, &na, &bh1))) {
+			brelse(bh);
+			hpfs_free_sectors(s, se, 1);
+			return -1;
+		}
+		if (a == node && fnod) {
+			anode->up = cpu_to_le32(node);
+			anode->btree.flags |= BP_fnode_parent;
+			anode->btree.n_used_nodes = btree->n_used_nodes;
+			anode->btree.first_free = btree->first_free;
+			anode->btree.n_free_nodes = 40 - anode->btree.n_used_nodes;
+			memcpy(&anode->u, &btree->u, btree->n_used_nodes * 12);
+			btree->flags |= BP_internal;
+			btree->n_free_nodes = 11;
+			btree->n_used_nodes = 1;
+			btree->first_free = cpu_to_le16((char *)&(btree->u.internal[1]) - (char *)btree);
+			btree->u.internal[0].file_secno = cpu_to_le32(-1);
+			btree->u.internal[0].down = cpu_to_le32(na);
+			mark_buffer_dirty(bh);
+		} else if (!(ranode = hpfs_alloc_anode(s, /*a*/0, &ra, &bh2))) {
+			brelse(bh);
+			brelse(bh1);
+			hpfs_free_sectors(s, se, 1);
+			hpfs_free_sectors(s, na, 1);
+			return -1;
+		}
+		brelse(bh);
+		bh = bh1;
+		btree = GET_BTREE_PTR(&anode->btree);
+	}
+	btree->n_free_nodes--; n = btree->n_used_nodes++;
+	le16_add_cpu(&btree->first_free, 12);
+	btree->u.external[n].disk_secno = cpu_to_le32(se);
+	btree->u.external[n].file_secno = cpu_to_le32(fs);
+	btree->u.external[n].length = cpu_to_le32(1);
+	mark_buffer_dirty(bh);
+	brelse(bh);
+	if ((a == node && fnod) || na == -1) return se;
+	c2 = 0;
+	while (up != (anode_secno)-1) {
+		struct anode *new_anode;
+		if (hpfs_sb(s)->sb_chk)
+			if (hpfs_stop_cycles(s, up, &c1, &c2, "hpfs_add_sector_to_btree #2")) return -1;
+		if (up != node || !fnod) {
+			if (!(anode = hpfs_map_anode(s, up, &bh))) return -1;
+			btree = GET_BTREE_PTR(&anode->btree);
+		} else {
+			if (!(fnode = hpfs_map_fnode(s, up, &bh))) return -1;
+			btree = GET_BTREE_PTR(&fnode->btree);
+		}
+		if (btree->n_free_nodes) {
+			btree->n_free_nodes--; n = btree->n_used_nodes++;
+			le16_add_cpu(&btree->first_free, 8);
+			btree->u.internal[n].file_secno = cpu_to_le32(-1);
+			btree->u.internal[n].down = cpu_to_le32(na);
+			btree->u.internal[n-1].file_secno = cpu_to_le32(fs);
+			mark_buffer_dirty(bh);
+			brelse(bh);
+			brelse(bh2);
+			hpfs_free_sectors(s, ra, 1);
+			if ((anode = hpfs_map_anode(s, na, &bh))) {
+				anode->up = cpu_to_le32(up);
+				if (up == node && fnod)
+					anode->btree.flags |= BP_fnode_parent;
+				else
+					anode->btree.flags &= ~BP_fnode_parent;
+				mark_buffer_dirty(bh);
+				brelse(bh);
+			}
+			return se;
+		}
+		up = up != node ? le32_to_cpu(anode->up) : -1;
+		btree->u.internal[btree->n_used_nodes - 1].file_secno = cpu_to_le32(/*fs*/-1);
+		mark_buffer_dirty(bh);
+		brelse(bh);
+		a = na;
+		if ((new_anode = hpfs_alloc_anode(s, a, &na, &bh))) {
+			anode = new_anode;
+			/*anode->up = cpu_to_le32(up != -1 ? up : ra);*/
+			anode->btree.flags |= BP_internal;
+			anode->btree.n_used_nodes = 1;
+			anode->btree.n_free_nodes = 59;
+			anode->btree.first_free = cpu_to_le16(16);
+			GET_BTREE_PTR(&anode->btree)->u.internal[0].down = cpu_to_le32(a);
+			GET_BTREE_PTR(&anode->btree)->u.internal[0].file_secno = cpu_to_le32(-1);
+			mark_buffer_dirty(bh);
+			brelse(bh);
+			if ((anode = hpfs_map_anode(s, a, &bh))) {
+				anode->up = cpu_to_le32(na);
+				mark_buffer_dirty(bh);
+				brelse(bh);
+			}
+		} else na = a;
+	}
+	if ((anode = hpfs_map_anode(s, na, &bh))) {
+		anode->up = cpu_to_le32(node);
+		if (fnod)
+			anode->btree.flags |= BP_fnode_parent;
+		mark_buffer_dirty(bh);
+		brelse(bh);
+	}
+	if (!fnod) {
+		if (!(anode = hpfs_map_anode(s, node, &bh))) {
+			brelse(bh2);
+			return -1;
+		}
+		btree = GET_BTREE_PTR(&anode->btree);
+	} else {
+		if (!(fnode = hpfs_map_fnode(s, node, &bh))) {
+			brelse(bh2);
+			return -1;
+		}
+		btree = GET_BTREE_PTR(&fnode->btree);
+	}
+	ranode->up = cpu_to_le32(node);
+	memcpy(&ranode->btree, btree, le16_to_cpu(btree->first_free));
+	if (fnod)
+		ranode->btree.flags |= BP_fnode_parent;
+	GET_BTREE_PTR(&ranode->btree)->n_free_nodes = (bp_internal(GET_BTREE_PTR(&ranode->btree)) ? 60 : 40) - GET_BTREE_PTR(&ranode->btree)->n_used_nodes;
+	if (bp_internal(GET_BTREE_PTR(&ranode->btree))) for (n = 0; n < GET_BTREE_PTR(&ranode->btree)->n_used_nodes; n++) {
+		struct anode *unode;
+		if ((unode = hpfs_map_anode(s, le32_to_cpu(ranode->u.internal[n].down), &bh1))) {
+			unode->up = cpu_to_le32(ra);
+			unode->btree.flags &= ~BP_fnode_parent;
+			mark_buffer_dirty(bh1);
+			brelse(bh1);
+		}
+	}
+	btree->flags |= BP_internal;
+	btree->n_free_nodes = fnod ? 10 : 58;
+	btree->n_used_nodes = 2;
+	btree->first_free = cpu_to_le16((char *)&btree->u.internal[2] - (char *)btree);
+	btree->u.internal[0].file_secno = cpu_to_le32(fs);
+	btree->u.internal[0].down = cpu_to_le32(ra);
+	btree->u.internal[1].file_secno = cpu_to_le32(-1);
+	btree->u.internal[1].down = cpu_to_le32(na);
+	mark_buffer_dirty(bh);
+	brelse(bh);
+	mark_buffer_dirty(bh2);
+	brelse(bh2);
+	return se;
+}
+
+/*
+ * Remove allocation tree. Recursion would look much nicer but
+ * I want to avoid it because it can cause stack overflow.
+ */
+
+void hpfs_remove_btree(struct super_block *s, struct bplus_header *btree)
+{
+	struct bplus_header *btree1 = btree;
+	struct anode *anode = NULL;
+	anode_secno ano = 0, oano;
+	struct buffer_head *bh;
+	int level = 0;
+	int pos = 0;
+	int i;
+	int c1, c2 = 0;
+	int d1, d2;
+	go_down:
+	d2 = 0;
+	while (bp_internal(btree1)) {
+		ano = le32_to_cpu(btree1->u.internal[pos].down);
+		if (level) brelse(bh);
+		if (hpfs_sb(s)->sb_chk)
+			if (hpfs_stop_cycles(s, ano, &d1, &d2, "hpfs_remove_btree #1"))
+				return;
+		if (!(anode = hpfs_map_anode(s, ano, &bh))) return;
+		btree1 = GET_BTREE_PTR(&anode->btree);
+		level++;
+		pos = 0;
+	}
+	for (i = 0; i < btree1->n_used_nodes; i++)
+		hpfs_free_sectors(s, le32_to_cpu(btree1->u.external[i].disk_secno), le32_to_cpu(btree1->u.external[i].length));
+	go_up:
+	if (!level) return;
+	brelse(bh);
+	if (hpfs_sb(s)->sb_chk)
+		if (hpfs_stop_cycles(s, ano, &c1, &c2, "hpfs_remove_btree #2")) return;
+	hpfs_free_sectors(s, ano, 1);
+	oano = ano;
+	ano = le32_to_cpu(anode->up);
+	if (--level) {
+		if (!(anode = hpfs_map_anode(s, ano, &bh))) return;
+		btree1 = GET_BTREE_PTR(&anode->btree);
+	} else btree1 = btree;
+	for (i = 0; i < btree1->n_used_nodes; i++) {
+		if (le32_to_cpu(btree1->u.internal[i].down) == oano) {
+			if ((pos = i + 1) < btree1->n_used_nodes)
+				goto go_down;
+			else
+				goto go_up;
+		}
+	}
+	hpfs_error(s,
+		   "reference to anode %08x not found in anode %08x "
+		   "(probably bad up pointer)",
+		   oano, level ? ano : -1);
+	if (level)
+		brelse(bh);
+}
+
+/* Just a wrapper around hpfs_bplus_lookup .. used for reading eas */
+
+static secno anode_lookup(struct super_block *s, anode_secno a, unsigned sec)
+{
+	struct anode *anode;
+	struct buffer_head *bh;
+	if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
+	return hpfs_bplus_lookup(s, NULL, GET_BTREE_PTR(&anode->btree), sec, bh);
+}
+
+int hpfs_ea_read(struct super_block *s, secno a, int ano, unsigned pos,
+	    unsigned len, char *buf)
+{
+	struct buffer_head *bh;
+	char *data;
+	secno sec;
+	unsigned l;
+	while (len) {
+		if (ano) {
+			if ((sec = anode_lookup(s, a, pos >> 9)) == -1)
+				return -1;
+		} else sec = a + (pos >> 9);
+		if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, sec, 1, "ea #1")) return -1;
+		if (!(data = hpfs_map_sector(s, sec, &bh, (len - 1) >> 9)))
+			return -1;
+		l = 0x200 - (pos & 0x1ff); if (l > len) l = len;
+		memcpy(buf, data + (pos & 0x1ff), l);
+		brelse(bh);
+		buf += l; pos += l; len -= l;
+	}
+	return 0;
+}
+
+int hpfs_ea_write(struct super_block *s, secno a, int ano, unsigned pos,
+	     unsigned len, const char *buf)
+{
+	struct buffer_head *bh;
+	char *data;
+	secno sec;
+	unsigned l;
+	while (len) {
+		if (ano) {
+			if ((sec = anode_lookup(s, a, pos >> 9)) == -1)
+				return -1;
+		} else sec = a + (pos >> 9);
+		if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, sec, 1, "ea #2")) return -1;
+		if (!(data = hpfs_map_sector(s, sec, &bh, (len - 1) >> 9)))
+			return -1;
+		l = 0x200 - (pos & 0x1ff); if (l > len) l = len;
+		memcpy(data + (pos & 0x1ff), buf, l);
+		mark_buffer_dirty(bh);
+		brelse(bh);
+		buf += l; pos += l; len -= l;
+	}
+	return 0;
+}
+
+void hpfs_ea_remove(struct super_block *s, secno a, int ano, unsigned len)
+{
+	struct anode *anode;
+	struct buffer_head *bh;
+	if (ano) {
+		if (!(anode = hpfs_map_anode(s, a, &bh))) return;
+		hpfs_remove_btree(s, GET_BTREE_PTR(&anode->btree));
+		brelse(bh);
+		hpfs_free_sectors(s, a, 1);
+	} else hpfs_free_sectors(s, a, (len + 511) >> 9);
+}
+
+/* Truncate allocation tree. Doesn't join anodes - I hope it doesn't matter */
+
+void hpfs_truncate_btree(struct super_block *s, secno f, int fno, unsigned secs)
+{
+	struct fnode *fnode;
+	struct anode *anode;
+	struct buffer_head *bh;
+	struct bplus_header *btree;
+	anode_secno node = f;
+	int i, j, nodes;
+	int c1, c2 = 0;
+	if (fno) {
+		if (!(fnode = hpfs_map_fnode(s, f, &bh))) return;
+		btree = GET_BTREE_PTR(&fnode->btree);
+	} else {
+		if (!(anode = hpfs_map_anode(s, f, &bh))) return;
+		btree = GET_BTREE_PTR(&anode->btree);
+	}
+	if (!secs) {
+		hpfs_remove_btree(s, btree);
+		if (fno) {
+			btree->n_free_nodes = 8;
+			btree->n_used_nodes = 0;
+			btree->first_free = cpu_to_le16(8);
+			btree->flags &= ~BP_internal;
+			mark_buffer_dirty(bh);
+		} else hpfs_free_sectors(s, f, 1);
+		brelse(bh);
+		return;
+	}
+	while (bp_internal(btree)) {
+		nodes = btree->n_used_nodes + btree->n_free_nodes;
+		for (i = 0; i < btree->n_used_nodes; i++)
+			if (le32_to_cpu(btree->u.internal[i].file_secno) >= secs) goto f;
+		brelse(bh);
+		hpfs_error(s, "internal btree %08x doesn't end with -1", node);
+		return;
+		f:
+		for (j = i + 1; j < btree->n_used_nodes; j++)
+			hpfs_ea_remove(s, le32_to_cpu(btree->u.internal[j].down), 1, 0);
+		btree->n_used_nodes = i + 1;
+		btree->n_free_nodes = nodes - btree->n_used_nodes;
+		btree->first_free = cpu_to_le16(8 + 8 * btree->n_used_nodes);
+		mark_buffer_dirty(bh);
+		if (btree->u.internal[i].file_secno == cpu_to_le32(secs)) {
+			brelse(bh);
+			return;
+		}
+		node = le32_to_cpu(btree->u.internal[i].down);
+		brelse(bh);
+		if (hpfs_sb(s)->sb_chk)
+			if (hpfs_stop_cycles(s, node, &c1, &c2, "hpfs_truncate_btree"))
+				return;
+		if (!(anode = hpfs_map_anode(s, node, &bh))) return;
+		btree = GET_BTREE_PTR(&anode->btree);
+	}	
+	nodes = btree->n_used_nodes + btree->n_free_nodes;
+	for (i = 0; i < btree->n_used_nodes; i++)
+		if (le32_to_cpu(btree->u.external[i].file_secno) + le32_to_cpu(btree->u.external[i].length) >= secs) goto ff;
+	brelse(bh);
+	return;
+	ff:
+	if (secs <= le32_to_cpu(btree->u.external[i].file_secno)) {
+		hpfs_error(s, "there is an allocation error in file %08x, sector %08x", f, secs);
+		if (i) i--;
+	}
+	else if (le32_to_cpu(btree->u.external[i].file_secno) + le32_to_cpu(btree->u.external[i].length) > secs) {
+		hpfs_free_sectors(s, le32_to_cpu(btree->u.external[i].disk_secno) + secs -
+			le32_to_cpu(btree->u.external[i].file_secno), le32_to_cpu(btree->u.external[i].length)
+			- secs + le32_to_cpu(btree->u.external[i].file_secno)); /* I hope gcc optimizes this :-) */
+		btree->u.external[i].length = cpu_to_le32(secs - le32_to_cpu(btree->u.external[i].file_secno));
+	}
+	for (j = i + 1; j < btree->n_used_nodes; j++)
+		hpfs_free_sectors(s, le32_to_cpu(btree->u.external[j].disk_secno), le32_to_cpu(btree->u.external[j].length));
+	btree->n_used_nodes = i + 1;
+	btree->n_free_nodes = nodes - btree->n_used_nodes;
+	btree->first_free = cpu_to_le16(8 + 12 * btree->n_used_nodes);
+	mark_buffer_dirty(bh);
+	brelse(bh);
+}
+
+/* Remove file or directory and it's eas - note that directory must
+   be empty when this is called. */
+
+void hpfs_remove_fnode(struct super_block *s, fnode_secno fno)
+{
+	struct buffer_head *bh;
+	struct fnode *fnode;
+	struct extended_attribute *ea;
+	struct extended_attribute *ea_end;
+	if (!(fnode = hpfs_map_fnode(s, fno, &bh))) return;
+	if (!fnode_is_dir(fnode)) hpfs_remove_btree(s, GET_BTREE_PTR(&fnode->btree));
+	else hpfs_remove_dtree(s, le32_to_cpu(fnode->u.external[0].disk_secno));
+	ea_end = fnode_end_ea(fnode);
+	for (ea = fnode_ea(fnode); ea < ea_end; ea = next_ea(ea))
+		if (ea_indirect(ea))
+			hpfs_ea_remove(s, ea_sec(ea), ea_in_anode(ea), ea_len(ea));
+	hpfs_ea_ext_remove(s, le32_to_cpu(fnode->ea_secno), fnode_in_anode(fnode), le32_to_cpu(fnode->ea_size_l));
+	brelse(bh);
+	hpfs_free_sectors(s, fno, 1);
+}
diff --git a/fs/hpfs/buffer.c b/fs/hpfs/buffer.c
new file mode 100644
index 000000000..d39246865
--- /dev/null
+++ b/fs/hpfs/buffer.c
@@ -0,0 +1,232 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/hpfs/buffer.c
+ *
+ *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
+ *
+ *  general buffer i/o
+ */
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/blkdev.h>
+#include "hpfs_fn.h"
+
+secno hpfs_search_hotfix_map(struct super_block *s, secno sec)
+{
+	unsigned i;
+	struct hpfs_sb_info *sbi = hpfs_sb(s);
+	for (i = 0; unlikely(i < sbi->n_hotfixes); i++) {
+		if (sbi->hotfix_from[i] == sec) {
+			return sbi->hotfix_to[i];
+		}
+	}
+	return sec;
+}
+
+unsigned hpfs_search_hotfix_map_for_range(struct super_block *s, secno sec, unsigned n)
+{
+	unsigned i;
+	struct hpfs_sb_info *sbi = hpfs_sb(s);
+	for (i = 0; unlikely(i < sbi->n_hotfixes); i++) {
+		if (sbi->hotfix_from[i] >= sec && sbi->hotfix_from[i] < sec + n) {
+			n = sbi->hotfix_from[i] - sec;
+		}
+	}
+	return n;
+}
+
+void hpfs_prefetch_sectors(struct super_block *s, unsigned secno, int n)
+{
+	struct buffer_head *bh;
+	struct blk_plug plug;
+
+	if (n <= 0 || unlikely(secno >= hpfs_sb(s)->sb_fs_size))
+		return;
+
+	if (unlikely(hpfs_search_hotfix_map_for_range(s, secno, n) != n))
+		return;
+
+	bh = sb_find_get_block(s, secno);
+	if (bh) {
+		if (buffer_uptodate(bh)) {
+			brelse(bh);
+			return;
+		}
+		brelse(bh);
+	}
+
+	blk_start_plug(&plug);
+	while (n > 0) {
+		if (unlikely(secno >= hpfs_sb(s)->sb_fs_size))
+			break;
+		sb_breadahead(s, secno);
+		secno++;
+		n--;
+	}
+	blk_finish_plug(&plug);
+}
+
+/* Map a sector into a buffer and return pointers to it and to the buffer. */
+
+void *hpfs_map_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp,
+		 int ahead)
+{
+	struct buffer_head *bh;
+
+	hpfs_lock_assert(s);
+
+	hpfs_prefetch_sectors(s, secno, ahead);
+
+	cond_resched();
+
+	*bhp = bh = sb_bread(s, hpfs_search_hotfix_map(s, secno));
+	if (bh != NULL)
+		return bh->b_data;
+	else {
+		pr_err("%s(): read error\n", __func__);
+		return NULL;
+	}
+}
+
+/* Like hpfs_map_sector but don't read anything */
+
+void *hpfs_get_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp)
+{
+	struct buffer_head *bh;
+	/*return hpfs_map_sector(s, secno, bhp, 0);*/
+
+	hpfs_lock_assert(s);
+
+	cond_resched();
+
+	if ((*bhp = bh = sb_getblk(s, hpfs_search_hotfix_map(s, secno))) != NULL) {
+		if (!buffer_uptodate(bh)) wait_on_buffer(bh);
+		set_buffer_uptodate(bh);
+		return bh->b_data;
+	} else {
+		pr_err("%s(): getblk failed\n", __func__);
+		return NULL;
+	}
+}
+
+/* Map 4 sectors into a 4buffer and return pointers to it and to the buffer. */
+
+void *hpfs_map_4sectors(struct super_block *s, unsigned secno, struct quad_buffer_head *qbh,
+		   int ahead)
+{
+	char *data;
+
+	hpfs_lock_assert(s);
+
+	cond_resched();
+
+	if (secno & 3) {
+		pr_err("%s(): unaligned read\n", __func__);
+		return NULL;
+	}
+
+	hpfs_prefetch_sectors(s, secno, 4 + ahead);
+
+	if (!hpfs_map_sector(s, secno + 0, &qbh->bh[0], 0)) goto bail0;
+	if (!hpfs_map_sector(s, secno + 1, &qbh->bh[1], 0)) goto bail1;
+	if (!hpfs_map_sector(s, secno + 2, &qbh->bh[2], 0)) goto bail2;
+	if (!hpfs_map_sector(s, secno + 3, &qbh->bh[3], 0)) goto bail3;
+
+	if (likely(qbh->bh[1]->b_data == qbh->bh[0]->b_data + 1 * 512) &&
+	    likely(qbh->bh[2]->b_data == qbh->bh[0]->b_data + 2 * 512) &&
+	    likely(qbh->bh[3]->b_data == qbh->bh[0]->b_data + 3 * 512)) {
+		return qbh->data = qbh->bh[0]->b_data;
+	}
+
+	qbh->data = data = kmalloc(2048, GFP_NOFS);
+	if (!data) {
+		pr_err("%s(): out of memory\n", __func__);
+		goto bail4;
+	}
+
+	memcpy(data + 0 * 512, qbh->bh[0]->b_data, 512);
+	memcpy(data + 1 * 512, qbh->bh[1]->b_data, 512);
+	memcpy(data + 2 * 512, qbh->bh[2]->b_data, 512);
+	memcpy(data + 3 * 512, qbh->bh[3]->b_data, 512);
+
+	return data;
+
+ bail4:
+	brelse(qbh->bh[3]);
+ bail3:
+	brelse(qbh->bh[2]);
+ bail2:
+	brelse(qbh->bh[1]);
+ bail1:
+	brelse(qbh->bh[0]);
+ bail0:
+	return NULL;
+}
+
+/* Don't read sectors */
+
+void *hpfs_get_4sectors(struct super_block *s, unsigned secno,
+                          struct quad_buffer_head *qbh)
+{
+	cond_resched();
+
+	hpfs_lock_assert(s);
+
+	if (secno & 3) {
+		pr_err("%s(): unaligned read\n", __func__);
+		return NULL;
+	}
+
+	if (!hpfs_get_sector(s, secno + 0, &qbh->bh[0])) goto bail0;
+	if (!hpfs_get_sector(s, secno + 1, &qbh->bh[1])) goto bail1;
+	if (!hpfs_get_sector(s, secno + 2, &qbh->bh[2])) goto bail2;
+	if (!hpfs_get_sector(s, secno + 3, &qbh->bh[3])) goto bail3;
+
+	if (likely(qbh->bh[1]->b_data == qbh->bh[0]->b_data + 1 * 512) &&
+	    likely(qbh->bh[2]->b_data == qbh->bh[0]->b_data + 2 * 512) &&
+	    likely(qbh->bh[3]->b_data == qbh->bh[0]->b_data + 3 * 512)) {
+		return qbh->data = qbh->bh[0]->b_data;
+	}
+
+	if (!(qbh->data = kmalloc(2048, GFP_NOFS))) {
+		pr_err("%s(): out of memory\n", __func__);
+		goto bail4;
+	}
+	return qbh->data;
+
+bail4:
+	brelse(qbh->bh[3]);
+bail3:
+	brelse(qbh->bh[2]);
+bail2:
+	brelse(qbh->bh[1]);
+bail1:
+	brelse(qbh->bh[0]);
+bail0:
+	return NULL;
+}
+	
+
+void hpfs_brelse4(struct quad_buffer_head *qbh)
+{
+	if (unlikely(qbh->data != qbh->bh[0]->b_data))
+		kfree(qbh->data);
+	brelse(qbh->bh[0]);
+	brelse(qbh->bh[1]);
+	brelse(qbh->bh[2]);
+	brelse(qbh->bh[3]);
+}	
+
+void hpfs_mark_4buffers_dirty(struct quad_buffer_head *qbh)
+{
+	if (unlikely(qbh->data != qbh->bh[0]->b_data)) {
+		memcpy(qbh->bh[0]->b_data, qbh->data + 0 * 512, 512);
+		memcpy(qbh->bh[1]->b_data, qbh->data + 1 * 512, 512);
+		memcpy(qbh->bh[2]->b_data, qbh->data + 2 * 512, 512);
+		memcpy(qbh->bh[3]->b_data, qbh->data + 3 * 512, 512);
+	}
+	mark_buffer_dirty(qbh->bh[0]);
+	mark_buffer_dirty(qbh->bh[1]);
+	mark_buffer_dirty(qbh->bh[2]);
+	mark_buffer_dirty(qbh->bh[3]);
+}
diff --git a/fs/hpfs/dentry.c b/fs/hpfs/dentry.c
new file mode 100644
index 000000000..89a36fdc6
--- /dev/null
+++ b/fs/hpfs/dentry.c
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/hpfs/dentry.c
+ *
+ *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
+ *
+ *  dcache operations
+ */
+
+#include "hpfs_fn.h"
+
+/*
+ * Note: the dentry argument is the parent dentry.
+ */
+
+static int hpfs_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
+{
+	unsigned long	 hash;
+	int		 i;
+	unsigned l = qstr->len;
+
+	if (l == 1) if (qstr->name[0]=='.') goto x;
+	if (l == 2) if (qstr->name[0]=='.' || qstr->name[1]=='.') goto x;
+	hpfs_adjust_length(qstr->name, &l);
+	/*if (hpfs_chk_name(qstr->name,&l))*/
+		/*return -ENAMETOOLONG;*/
+		/*return -ENOENT;*/
+	x:
+
+	hash = init_name_hash(dentry);
+	for (i = 0; i < l; i++)
+		hash = partial_name_hash(hpfs_upcase(hpfs_sb(dentry->d_sb)->sb_cp_table,qstr->name[i]), hash);
+	qstr->hash = end_name_hash(hash);
+
+	return 0;
+}
+
+static int hpfs_compare_dentry(const struct dentry *dentry,
+		unsigned int len, const char *str, const struct qstr *name)
+{
+	unsigned al = len;
+	unsigned bl = name->len;
+
+	hpfs_adjust_length(str, &al);
+	/*hpfs_adjust_length(b->name, &bl);*/
+
+	/*
+	 * 'str' is the nane of an already existing dentry, so the name
+	 * must be valid. 'name' must be validated first.
+	 */
+
+	if (hpfs_chk_name(name->name, &bl))
+		return 1;
+	if (hpfs_compare_names(dentry->d_sb, str, al, name->name, bl, 0))
+		return 1;
+	return 0;
+}
+
+const struct dentry_operations hpfs_dentry_operations = {
+	.d_hash		= hpfs_hash_dentry,
+	.d_compare	= hpfs_compare_dentry,
+};
diff --git a/fs/hpfs/dir.c b/fs/hpfs/dir.c
new file mode 100644
index 000000000..3bf11202e
--- /dev/null
+++ b/fs/hpfs/dir.c
@@ -0,0 +1,331 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/hpfs/dir.c
+ *
+ *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
+ *
+ *  directory VFS functions
+ */
+
+#include <linux/slab.h>
+#include "hpfs_fn.h"
+
+static int hpfs_dir_release(struct inode *inode, struct file *filp)
+{
+	hpfs_lock(inode->i_sb);
+	hpfs_del_pos(inode, &filp->f_pos);
+	/*hpfs_write_if_changed(inode);*/
+	hpfs_unlock(inode->i_sb);
+	return 0;
+}
+
+/* This is slow, but it's not used often */
+
+static loff_t hpfs_dir_lseek(struct file *filp, loff_t off, int whence)
+{
+	loff_t new_off = off + (whence == 1 ? filp->f_pos : 0);
+	loff_t pos;
+	struct quad_buffer_head qbh;
+	struct inode *i = file_inode(filp);
+	struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
+	struct super_block *s = i->i_sb;
+
+	/* Somebody else will have to figure out what to do here */
+	if (whence == SEEK_DATA || whence == SEEK_HOLE)
+		return -EINVAL;
+
+	inode_lock(i);
+	hpfs_lock(s);
+
+	/*pr_info("dir lseek\n");*/
+	if (new_off == 0 || new_off == 1 || new_off == 11 || new_off == 12 || new_off == 13) goto ok;
+	pos = ((loff_t) hpfs_de_as_down_as_possible(s, hpfs_inode->i_dno) << 4) + 1;
+	while (pos != new_off) {
+		if (map_pos_dirent(i, &pos, &qbh)) hpfs_brelse4(&qbh);
+		else goto fail;
+		if (pos == 12) goto fail;
+	}
+	if (unlikely(hpfs_add_pos(i, &filp->f_pos) < 0)) {
+		hpfs_unlock(s);
+		inode_unlock(i);
+		return -ENOMEM;
+	}
+ok:
+	filp->f_pos = new_off;
+	hpfs_unlock(s);
+	inode_unlock(i);
+	return new_off;
+fail:
+	/*pr_warn("illegal lseek: %016llx\n", new_off);*/
+	hpfs_unlock(s);
+	inode_unlock(i);
+	return -ESPIPE;
+}
+
+static int hpfs_readdir(struct file *file, struct dir_context *ctx)
+{
+	struct inode *inode = file_inode(file);
+	struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
+	struct quad_buffer_head qbh;
+	struct hpfs_dirent *de;
+	int lc;
+	loff_t next_pos;
+	unsigned char *tempname;
+	int c1, c2 = 0;
+	int ret = 0;
+
+	hpfs_lock(inode->i_sb);
+
+	if (hpfs_sb(inode->i_sb)->sb_chk) {
+		if (hpfs_chk_sectors(inode->i_sb, inode->i_ino, 1, "dir_fnode")) {
+			ret = -EFSERROR;
+			goto out;
+		}
+		if (hpfs_chk_sectors(inode->i_sb, hpfs_inode->i_dno, 4, "dir_dnode")) {
+			ret = -EFSERROR;
+			goto out;
+		}
+	}
+	if (hpfs_sb(inode->i_sb)->sb_chk >= 2) {
+		struct buffer_head *bh;
+		struct fnode *fno;
+		int e = 0;
+		if (!(fno = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) {
+			ret = -EIOERROR;
+			goto out;
+		}
+		if (!fnode_is_dir(fno)) {
+			e = 1;
+			hpfs_error(inode->i_sb, "not a directory, fnode %08llx",
+					inode->i_ino);
+		}
+		if (hpfs_inode->i_dno != le32_to_cpu(fno->u.external[0].disk_secno)) {
+			e = 1;
+			hpfs_error(inode->i_sb, "corrupted inode: i_dno == %08x, fnode -> dnode == %08x", hpfs_inode->i_dno, le32_to_cpu(fno->u.external[0].disk_secno));
+		}
+		brelse(bh);
+		if (e) {
+			ret = -EFSERROR;
+			goto out;
+		}
+	}
+	lc = hpfs_sb(inode->i_sb)->sb_lowercase;
+	if (ctx->pos == 12) { /* diff -r requires this (note, that diff -r */
+		ctx->pos = 13; /* also fails on msdos filesystem in 2.0) */
+		goto out;
+	}
+	if (ctx->pos == 13) {
+		ret = -ENOENT;
+		goto out;
+	}
+	
+	while (1) {
+		again:
+		/* This won't work when cycle is longer than number of dirents
+		   accepted by filldir, but what can I do?
+		   maybe killall -9 ls helps */
+		if (hpfs_sb(inode->i_sb)->sb_chk)
+			if (hpfs_stop_cycles(inode->i_sb, ctx->pos, &c1, &c2, "hpfs_readdir")) {
+				ret = -EFSERROR;
+				goto out;
+			}
+		if (ctx->pos == 12)
+			goto out;
+		if (ctx->pos == 3 || ctx->pos == 4 || ctx->pos == 5) {
+			pr_err("pos==%d\n", (int)ctx->pos);
+			goto out;
+		}
+		if (ctx->pos == 0) {
+			if (!dir_emit_dot(file, ctx))
+				goto out;
+			ctx->pos = 11;
+		}
+		if (ctx->pos == 11) {
+			if (!dir_emit(ctx, "..", 2, hpfs_inode->i_parent_dir, DT_DIR))
+				goto out;
+			ctx->pos = 1;
+		}
+		if (ctx->pos == 1) {
+			ret = hpfs_add_pos(inode, &file->f_pos);
+			if (unlikely(ret < 0))
+				goto out;
+			ctx->pos = ((loff_t) hpfs_de_as_down_as_possible(inode->i_sb, hpfs_inode->i_dno) << 4) + 1;
+		}
+		next_pos = ctx->pos;
+		if (!(de = map_pos_dirent(inode, &next_pos, &qbh))) {
+			ctx->pos = next_pos;
+			ret = -EIOERROR;
+			goto out;
+		}
+		if (de->first || de->last) {
+			if (hpfs_sb(inode->i_sb)->sb_chk) {
+				if (de->first && !de->last && (de->namelen != 2
+				    || de ->name[0] != 1 || de->name[1] != 1))
+					hpfs_error(inode->i_sb, "hpfs_readdir: bad ^A^A entry; pos = %08lx", (unsigned long)ctx->pos);
+				if (de->last && (de->namelen != 1 || de ->name[0] != 255))
+					hpfs_error(inode->i_sb, "hpfs_readdir: bad \\377 entry; pos = %08lx", (unsigned long)ctx->pos);
+			}
+			hpfs_brelse4(&qbh);
+			ctx->pos = next_pos;
+			goto again;
+		}
+		tempname = hpfs_translate_name(inode->i_sb, de->name, de->namelen, lc, de->not_8x3);
+		if (!dir_emit(ctx, tempname, de->namelen, le32_to_cpu(de->fnode), DT_UNKNOWN)) {
+			if (tempname != de->name) kfree(tempname);
+			hpfs_brelse4(&qbh);
+			goto out;
+		}
+		ctx->pos = next_pos;
+		if (tempname != de->name) kfree(tempname);
+		hpfs_brelse4(&qbh);
+	}
+out:
+	hpfs_unlock(inode->i_sb);
+	return ret;
+}
+
+/*
+ * lookup.  Search the specified directory for the specified name, set
+ * *result to the corresponding inode.
+ *
+ * lookup uses the inode number to tell read_inode whether it is reading
+ * the inode of a directory or a file -- file ino's are odd, directory
+ * ino's are even.  read_inode avoids i/o for file inodes; everything
+ * needed is up here in the directory.  (And file fnodes are out in
+ * the boondocks.)
+ *
+ *    - M.P.: this is over, sometimes we've got to read file's fnode for eas
+ *	      inode numbers are just fnode sector numbers; iget lock is used
+ *	      to tell read_inode to read fnode or not.
+ */
+
+struct dentry *hpfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
+{
+	const unsigned char *name = dentry->d_name.name;
+	unsigned len = dentry->d_name.len;
+	struct quad_buffer_head qbh;
+	struct hpfs_dirent *de;
+	ino_t ino;
+	int err;
+	struct inode *result = NULL;
+	struct hpfs_inode_info *hpfs_result;
+
+	hpfs_lock(dir->i_sb);
+	if ((err = hpfs_chk_name(name, &len))) {
+		if (err == -ENAMETOOLONG) {
+			hpfs_unlock(dir->i_sb);
+			return ERR_PTR(-ENAMETOOLONG);
+		}
+		goto end_add;
+	}
+
+	/*
+	 * '.' and '..' will never be passed here.
+	 */
+
+	de = map_dirent(dir, hpfs_i(dir)->i_dno, name, len, NULL, &qbh);
+
+	/*
+	 * This is not really a bailout, just means file not found.
+	 */
+
+	if (!de) goto end;
+
+	/*
+	 * Get inode number, what we're after.
+	 */
+
+	ino = le32_to_cpu(de->fnode);
+
+	/*
+	 * Go find or make an inode.
+	 */
+
+	result = iget_locked(dir->i_sb, ino);
+	if (!result) {
+		hpfs_error(dir->i_sb, "hpfs_lookup: can't get inode");
+		result = ERR_PTR(-ENOMEM);
+		goto bail1;
+	}
+	if (inode_state_read_once(result) & I_NEW) {
+		hpfs_init_inode(result);
+		if (de->directory)
+			hpfs_read_inode(result);
+		else if (le32_to_cpu(de->ea_size) && hpfs_sb(dir->i_sb)->sb_eas)
+			hpfs_read_inode(result);
+		else {
+			result->i_mode |= S_IFREG;
+			result->i_mode &= ~0111;
+			result->i_op = &hpfs_file_iops;
+			result->i_fop = &hpfs_file_ops;
+			set_nlink(result, 1);
+		}
+		unlock_new_inode(result);
+	}
+	hpfs_result = hpfs_i(result);
+	if (!de->directory) hpfs_result->i_parent_dir = dir->i_ino;
+
+	if (de->has_acl || de->has_xtd_perm) if (!sb_rdonly(dir->i_sb)) {
+		hpfs_error(result->i_sb, "ACLs or XPERM found. This is probably HPFS386. This driver doesn't support it now. Send me some info on these structures");
+		iput(result);
+		result = ERR_PTR(-EINVAL);
+		goto bail1;
+	}
+
+	/*
+	 * Fill in the info from the directory if this is a newly created
+	 * inode.
+	 */
+
+	if (!inode_get_ctime_sec(result)) {
+		time64_t csec = local_to_gmt(dir->i_sb, le32_to_cpu(de->creation_date));
+
+		inode_set_ctime(result, csec ? csec : 1, 0);
+		inode_set_mtime(result,
+				local_to_gmt(dir->i_sb, le32_to_cpu(de->write_date)),
+				0);
+		inode_set_atime(result,
+				local_to_gmt(dir->i_sb, le32_to_cpu(de->read_date)),
+				0);
+		hpfs_result->i_ea_size = le32_to_cpu(de->ea_size);
+		if (!hpfs_result->i_ea_mode && de->read_only)
+			result->i_mode &= ~0222;
+		if (!de->directory) {
+			if (result->i_size == -1) {
+				result->i_size = le32_to_cpu(de->file_size);
+				result->i_data.a_ops = &hpfs_aops;
+				hpfs_i(result)->mmu_private = result->i_size;
+			/*
+			 * i_blocks should count the fnode and any anodes.
+			 * We count 1 for the fnode and don't bother about
+			 * anodes -- the disk heads are on the directory band
+			 * and we want them to stay there.
+			 */
+				result->i_blocks = 1 + ((result->i_size + 511) >> 9);
+			}
+		}
+	}
+
+bail1:
+	hpfs_brelse4(&qbh);
+
+	/*
+	 * Made it.
+	 */
+
+end:
+end_add:
+	hpfs_unlock(dir->i_sb);
+	return d_splice_alias(result, dentry);
+}
+
+const struct file_operations hpfs_dir_ops =
+{
+	.llseek		= hpfs_dir_lseek,
+	.read		= generic_read_dir,
+	.iterate_shared	= hpfs_readdir,
+	.release	= hpfs_dir_release,
+	.fsync		= hpfs_file_fsync,
+	.unlocked_ioctl	= hpfs_ioctl,
+	.compat_ioctl	= compat_ptr_ioctl,
+};
diff --git a/fs/hpfs/dnode.c b/fs/hpfs/dnode.c
new file mode 100644
index 000000000..8c6aa060f
--- /dev/null
+++ b/fs/hpfs/dnode.c
@@ -0,0 +1,1095 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/hpfs/dnode.c
+ *
+ *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
+ *
+ *  handling directory dnode tree - adding, deleteing & searching for dirents
+ */
+
+#include "hpfs_fn.h"
+
+static loff_t get_pos(struct dnode *d, struct hpfs_dirent *fde)
+{
+	struct hpfs_dirent *de;
+	struct hpfs_dirent *de_end = dnode_end_de(d);
+	int i = 1;
+	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de)) {
+		if (de == fde) return ((loff_t) le32_to_cpu(d->self) << 4) | (loff_t)i;
+		i++;
+	}
+	pr_info("%s(): not_found\n", __func__);
+	return ((loff_t)le32_to_cpu(d->self) << 4) | (loff_t)1;
+}
+
+int hpfs_add_pos(struct inode *inode, loff_t *pos)
+{
+	struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
+	int i = 0;
+	loff_t **ppos;
+
+	if (hpfs_inode->i_rddir_off)
+		for (; hpfs_inode->i_rddir_off[i]; i++)
+			if (hpfs_inode->i_rddir_off[i] == pos)
+				return 0;
+	if (!(i&0x0f)) {
+		ppos = kmalloc_objs(loff_t *, i + 0x11, GFP_NOFS);
+		if (!ppos) {
+			pr_err("out of memory for position list\n");
+			return -ENOMEM;
+		}
+		if (hpfs_inode->i_rddir_off) {
+			memcpy(ppos, hpfs_inode->i_rddir_off, i * sizeof(loff_t));
+			kfree(hpfs_inode->i_rddir_off);
+		}
+		hpfs_inode->i_rddir_off = ppos;
+	}
+	hpfs_inode->i_rddir_off[i] = pos;
+	hpfs_inode->i_rddir_off[i + 1] = NULL;
+	return 0;
+}
+
+void hpfs_del_pos(struct inode *inode, loff_t *pos)
+{
+	struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
+	loff_t **i, **j;
+
+	if (!hpfs_inode->i_rddir_off) goto not_f;
+	for (i = hpfs_inode->i_rddir_off; *i; i++) if (*i == pos) goto fnd;
+	goto not_f;
+	fnd:
+	for (j = i + 1; *j; j++) ;
+	*i = *(j - 1);
+	*(j - 1) = NULL;
+	if (j - 1 == hpfs_inode->i_rddir_off) {
+		kfree(hpfs_inode->i_rddir_off);
+		hpfs_inode->i_rddir_off = NULL;
+	}
+	return;
+	not_f:
+	/*pr_warn("position pointer %p->%08x not found\n",
+		  pos, (int)*pos);*/
+	return;
+}
+
+static void for_all_poss(struct inode *inode, void (*f)(loff_t *, loff_t, loff_t),
+			 loff_t p1, loff_t p2)
+{
+	struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
+	loff_t **i;
+
+	if (!hpfs_inode->i_rddir_off) return;
+	for (i = hpfs_inode->i_rddir_off; *i; i++) (*f)(*i, p1, p2);
+	return;
+}
+
+static void hpfs_pos_subst(loff_t *p, loff_t f, loff_t t)
+{
+	if (*p == f) *p = t;
+}
+
+/*void hpfs_hpfs_pos_substd(loff_t *p, loff_t f, loff_t t)
+{
+	if ((*p & ~0x3f) == (f & ~0x3f)) *p = (t & ~0x3f) | (*p & 0x3f);
+}*/
+
+static void hpfs_pos_ins(loff_t *p, loff_t d, loff_t c)
+{
+	if ((*p & ~0x3f) == (d & ~0x3f) && (*p & 0x3f) >= (d & 0x3f)) {
+		int n = (*p & 0x3f) + c;
+		if (n > 0x3f)
+			pr_err("%s(): %08x + %d\n",
+				__func__, (int)*p, (int)c >> 8);
+		else
+			*p = (*p & ~0x3f) | n;
+	}
+}
+
+static void hpfs_pos_del(loff_t *p, loff_t d, loff_t c)
+{
+	if ((*p & ~0x3f) == (d & ~0x3f) && (*p & 0x3f) >= (d & 0x3f)) {
+		int n = (*p & 0x3f) - c;
+		if (n < 1)
+			pr_err("%s(): %08x - %d\n",
+				__func__, (int)*p, (int)c >> 8);
+		else
+			*p = (*p & ~0x3f) | n;
+	}
+}
+
+static struct hpfs_dirent *dnode_pre_last_de(struct dnode *d)
+{
+	struct hpfs_dirent *de, *de_end, *dee = NULL, *deee = NULL;
+	de_end = dnode_end_de(d);
+	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de)) {
+		deee = dee; dee = de;
+	}	
+	return deee;
+}
+
+static struct hpfs_dirent *dnode_last_de(struct dnode *d)
+{
+	struct hpfs_dirent *de, *de_end, *dee = NULL;
+	de_end = dnode_end_de(d);
+	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de)) {
+		dee = de;
+	}	
+	return dee;
+}
+
+static void set_last_pointer(struct super_block *s, struct dnode *d, dnode_secno ptr)
+{
+	struct hpfs_dirent *de;
+	if (!(de = dnode_last_de(d))) {
+		hpfs_error(s, "set_last_pointer: empty dnode %08x", le32_to_cpu(d->self));
+		return;
+	}
+	if (hpfs_sb(s)->sb_chk) {
+		if (de->down) {
+			hpfs_error(s, "set_last_pointer: dnode %08x has already last pointer %08x",
+				le32_to_cpu(d->self), de_down_pointer(de));
+			return;
+		}
+		if (le16_to_cpu(de->length) != 32) {
+			hpfs_error(s, "set_last_pointer: bad last dirent in dnode %08x", le32_to_cpu(d->self));
+			return;
+		}
+	}
+	if (ptr) {
+		le32_add_cpu(&d->first_free, 4);
+		if (le32_to_cpu(d->first_free) > 2048) {
+			hpfs_error(s, "set_last_pointer: too long dnode %08x", le32_to_cpu(d->self));
+			le32_add_cpu(&d->first_free, -4);
+			return;
+		}
+		de->length = cpu_to_le16(36);
+		de->down = 1;
+		*(__le32 *)((char *)de + 32) = cpu_to_le32(ptr);
+	}
+}
+
+/* Add an entry to dnode and don't care if it grows over 2048 bytes */
+
+struct hpfs_dirent *hpfs_add_de(struct super_block *s, struct dnode *d,
+				const unsigned char *name,
+				unsigned namelen, secno down_ptr)
+{
+	struct hpfs_dirent *de;
+	struct hpfs_dirent *de_end = dnode_end_de(d);
+	unsigned d_size = de_size(namelen, down_ptr);
+	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de)) {
+		int c = hpfs_compare_names(s, name, namelen, de->name, de->namelen, de->last);
+		if (!c) {
+			hpfs_error(s, "name (%c,%d) already exists in dnode %08x", *name, namelen, le32_to_cpu(d->self));
+			return NULL;
+		}
+		if (c < 0) break;
+	}
+	memmove((char *)de + d_size, de, (char *)de_end - (char *)de);
+	memset(de, 0, d_size);
+	if (down_ptr) {
+		*(__le32 *)((char *)de + d_size - 4) = cpu_to_le32(down_ptr);
+		de->down = 1;
+	}
+	de->length = cpu_to_le16(d_size);
+	de->not_8x3 = hpfs_is_name_long(name, namelen);
+	de->namelen = namelen;
+	memcpy(de->name, name, namelen);
+	le32_add_cpu(&d->first_free, d_size);
+	return de;
+}
+
+/* Delete dirent and don't care about its subtree */
+
+static void hpfs_delete_de(struct super_block *s, struct dnode *d,
+			   struct hpfs_dirent *de)
+{
+	if (de->last) {
+		hpfs_error(s, "attempt to delete last dirent in dnode %08x", le32_to_cpu(d->self));
+		return;
+	}
+	d->first_free = cpu_to_le32(le32_to_cpu(d->first_free) - le16_to_cpu(de->length));
+	memmove(de, de_next_de(de), le32_to_cpu(d->first_free) + (char *)d - (char *)de);
+}
+
+static void fix_up_ptrs(struct super_block *s, struct dnode *d)
+{
+	struct hpfs_dirent *de;
+	struct hpfs_dirent *de_end = dnode_end_de(d);
+	dnode_secno dno = le32_to_cpu(d->self);
+	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de))
+		if (de->down) {
+			struct quad_buffer_head qbh;
+			struct dnode *dd;
+			if ((dd = hpfs_map_dnode(s, de_down_pointer(de), &qbh))) {
+				if (le32_to_cpu(dd->up) != dno || dd->root_dnode) {
+					dd->up = cpu_to_le32(dno);
+					dd->root_dnode = 0;
+					hpfs_mark_4buffers_dirty(&qbh);
+				}
+				hpfs_brelse4(&qbh);
+			}
+		}
+}
+
+/* Add an entry to dnode and do dnode splitting if required */
+
+static int hpfs_add_to_dnode(struct inode *i, dnode_secno dno,
+			     const unsigned char *name, unsigned namelen,
+			     struct hpfs_dirent *new_de, dnode_secno down_ptr)
+{
+	struct quad_buffer_head qbh, qbh1, qbh2;
+	struct dnode *d, *ad, *rd, *nd = NULL;
+	dnode_secno adno, rdno;
+	struct hpfs_dirent *de;
+	struct hpfs_dirent nde;
+	unsigned char *nname;
+	int h;
+	int pos;
+	struct buffer_head *bh;
+	struct fnode *fnode;
+	int c1, c2 = 0;
+	if (!(nname = kmalloc(256, GFP_NOFS))) {
+		pr_err("out of memory, can't add to dnode\n");
+		return 1;
+	}
+	go_up:
+	if (namelen >= 256) {
+		hpfs_error(i->i_sb, "%s(): namelen == %d", __func__, namelen);
+		kfree(nd);
+		kfree(nname);
+		return 1;
+	}
+	if (!(d = hpfs_map_dnode(i->i_sb, dno, &qbh))) {
+		kfree(nd);
+		kfree(nname);
+		return 1;
+	}
+	go_up_a:
+	if (hpfs_sb(i->i_sb)->sb_chk)
+		if (hpfs_stop_cycles(i->i_sb, dno, &c1, &c2, "hpfs_add_to_dnode")) {
+			hpfs_brelse4(&qbh);
+			kfree(nd);
+			kfree(nname);
+			return 1;
+		}
+	if (le32_to_cpu(d->first_free) + de_size(namelen, down_ptr) <= 2048) {
+		loff_t t;
+		copy_de(de=hpfs_add_de(i->i_sb, d, name, namelen, down_ptr), new_de);
+		t = get_pos(d, de);
+		for_all_poss(i, hpfs_pos_ins, t, 1);
+		for_all_poss(i, hpfs_pos_subst, 4, t);
+		for_all_poss(i, hpfs_pos_subst, 5, t + 1);
+		hpfs_mark_4buffers_dirty(&qbh);
+		hpfs_brelse4(&qbh);
+		kfree(nd);
+		kfree(nname);
+		return 0;
+	}
+	if (!nd) if (!(nd = kmalloc(0x924, GFP_NOFS))) {
+		/* 0x924 is a max size of dnode after adding a dirent with
+		   max name length. We alloc this only once. There must
+		   not be any error while splitting dnodes, otherwise the
+		   whole directory, not only file we're adding, would
+		   be lost. */
+		pr_err("out of memory for dnode splitting\n");
+		hpfs_brelse4(&qbh);
+		kfree(nname);
+		return 1;
+	}	
+	memcpy(nd, d, le32_to_cpu(d->first_free));
+	copy_de(de = hpfs_add_de(i->i_sb, nd, name, namelen, down_ptr), new_de);
+	for_all_poss(i, hpfs_pos_ins, get_pos(nd, de), 1);
+	h = ((char *)dnode_last_de(nd) - (char *)nd) / 2 + 10;
+	if (!(ad = hpfs_alloc_dnode(i->i_sb, le32_to_cpu(d->up), &adno, &qbh1))) {
+		hpfs_error(i->i_sb, "unable to alloc dnode - dnode tree will be corrupted");
+		hpfs_brelse4(&qbh);
+		kfree(nd);
+		kfree(nname);
+		return 1;
+	}
+	i->i_size += 2048;
+	i->i_blocks += 4;
+	pos = 1;
+	for (de = dnode_first_de(nd); (char *)de_next_de(de) - (char *)nd < h; de = de_next_de(de)) {
+		copy_de(hpfs_add_de(i->i_sb, ad, de->name, de->namelen, de->down ? de_down_pointer(de) : 0), de);
+		for_all_poss(i, hpfs_pos_subst, ((loff_t)dno << 4) | pos, ((loff_t)adno << 4) | pos);
+		pos++;
+	}
+	copy_de(new_de = &nde, de);
+	memcpy(nname, de->name, de->namelen);
+	name = nname;
+	namelen = de->namelen;
+	for_all_poss(i, hpfs_pos_subst, ((loff_t)dno << 4) | pos, 4);
+	down_ptr = adno;
+	set_last_pointer(i->i_sb, ad, de->down ? de_down_pointer(de) : 0);
+	de = de_next_de(de);
+	memmove((char *)nd + 20, de, le32_to_cpu(nd->first_free) + (char *)nd - (char *)de);
+	le32_add_cpu(&nd->first_free, -((char *)de - (char *)nd - 20));
+	memcpy(d, nd, le32_to_cpu(nd->first_free));
+	for_all_poss(i, hpfs_pos_del, (loff_t)dno << 4, pos);
+	fix_up_ptrs(i->i_sb, ad);
+	if (!d->root_dnode) {
+		ad->up = d->up;
+		dno = le32_to_cpu(ad->up);
+		hpfs_mark_4buffers_dirty(&qbh);
+		hpfs_brelse4(&qbh);
+		hpfs_mark_4buffers_dirty(&qbh1);
+		hpfs_brelse4(&qbh1);
+		goto go_up;
+	}
+	if (!(rd = hpfs_alloc_dnode(i->i_sb, le32_to_cpu(d->up), &rdno, &qbh2))) {
+		hpfs_error(i->i_sb, "unable to alloc dnode - dnode tree will be corrupted");
+		hpfs_brelse4(&qbh);
+		hpfs_brelse4(&qbh1);
+		kfree(nd);
+		kfree(nname);
+		return 1;
+	}
+	i->i_size += 2048;
+	i->i_blocks += 4;
+	rd->root_dnode = 1;
+	rd->up = d->up;
+	if (!(fnode = hpfs_map_fnode(i->i_sb, le32_to_cpu(d->up), &bh))) {
+		hpfs_free_dnode(i->i_sb, rdno);
+		hpfs_brelse4(&qbh);
+		hpfs_brelse4(&qbh1);
+		hpfs_brelse4(&qbh2);
+		kfree(nd);
+		kfree(nname);
+		return 1;
+	}
+	fnode->u.external[0].disk_secno = cpu_to_le32(rdno);
+	mark_buffer_dirty(bh);
+	brelse(bh);
+	hpfs_i(i)->i_dno = rdno;
+	d->up = ad->up = cpu_to_le32(rdno);
+	d->root_dnode = ad->root_dnode = 0;
+	hpfs_mark_4buffers_dirty(&qbh);
+	hpfs_brelse4(&qbh);
+	hpfs_mark_4buffers_dirty(&qbh1);
+	hpfs_brelse4(&qbh1);
+	qbh = qbh2;
+	set_last_pointer(i->i_sb, rd, dno);
+	dno = rdno;
+	d = rd;
+	goto go_up_a;
+}
+
+/*
+ * Add an entry to directory btree.
+ * I hate such crazy directory structure.
+ * It's easy to read but terrible to write.
+ * I wrote this directory code 4 times.
+ * I hope, now it's finally bug-free.
+ */
+
+int hpfs_add_dirent(struct inode *i,
+		    const unsigned char *name, unsigned namelen,
+		    struct hpfs_dirent *new_de)
+{
+	struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
+	struct dnode *d;
+	struct hpfs_dirent *de, *de_end;
+	struct quad_buffer_head qbh;
+	dnode_secno dno;
+	int c;
+	int c1, c2 = 0;
+	dno = hpfs_inode->i_dno;
+	down:
+	if (hpfs_sb(i->i_sb)->sb_chk)
+		if (hpfs_stop_cycles(i->i_sb, dno, &c1, &c2, "hpfs_add_dirent")) return 1;
+	if (!(d = hpfs_map_dnode(i->i_sb, dno, &qbh))) return 1;
+	de_end = dnode_end_de(d);
+	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de)) {
+		if (!(c = hpfs_compare_names(i->i_sb, name, namelen, de->name, de->namelen, de->last))) {
+			hpfs_brelse4(&qbh);
+			return -1;
+		}	
+		if (c < 0) {
+			if (de->down) {
+				dno = de_down_pointer(de);
+				hpfs_brelse4(&qbh);
+				goto down;
+			}
+			break;
+		}
+	}
+	hpfs_brelse4(&qbh);
+	if (hpfs_check_free_dnodes(i->i_sb, FREE_DNODES_ADD)) {
+		c = 1;
+		goto ret;
+	}	
+	c = hpfs_add_to_dnode(i, dno, name, namelen, new_de, 0);
+	ret:
+	return c;
+}
+
+/* 
+ * Find dirent with higher name in 'from' subtree and move it to 'to' dnode.
+ * Return the dnode we moved from (to be checked later if it's empty)
+ */
+
+static secno move_to_top(struct inode *i, dnode_secno from, dnode_secno to)
+{
+	dnode_secno dno, ddno;
+	dnode_secno chk_up = to;
+	struct dnode *dnode;
+	struct quad_buffer_head qbh;
+	struct hpfs_dirent *de, *nde;
+	int a;
+	loff_t t;
+	int c1, c2 = 0;
+	dno = from;
+	while (1) {
+		if (hpfs_sb(i->i_sb)->sb_chk)
+			if (hpfs_stop_cycles(i->i_sb, dno, &c1, &c2, "move_to_top"))
+				return 0;
+		if (!(dnode = hpfs_map_dnode(i->i_sb, dno, &qbh))) return 0;
+		if (hpfs_sb(i->i_sb)->sb_chk) {
+			if (le32_to_cpu(dnode->up) != chk_up) {
+				hpfs_error(i->i_sb, "move_to_top: up pointer from %08x should be %08x, is %08x",
+					dno, chk_up, le32_to_cpu(dnode->up));
+				hpfs_brelse4(&qbh);
+				return 0;
+			}
+			chk_up = dno;
+		}
+		if (!(de = dnode_last_de(dnode))) {
+			hpfs_error(i->i_sb, "move_to_top: dnode %08x has no last de", dno);
+			hpfs_brelse4(&qbh);
+			return 0;
+		}
+		if (!de->down) break;
+		dno = de_down_pointer(de);
+		hpfs_brelse4(&qbh);
+	}
+	while (!(de = dnode_pre_last_de(dnode))) {
+		dnode_secno up = le32_to_cpu(dnode->up);
+		hpfs_brelse4(&qbh);
+		hpfs_free_dnode(i->i_sb, dno);
+		i->i_size -= 2048;
+		i->i_blocks -= 4;
+		for_all_poss(i, hpfs_pos_subst, ((loff_t)dno << 4) | 1, 5);
+		if (up == to) return to;
+		if (!(dnode = hpfs_map_dnode(i->i_sb, up, &qbh))) return 0;
+		if (dnode->root_dnode) {
+			hpfs_error(i->i_sb, "move_to_top: got to root_dnode while moving from %08x to %08x", from, to);
+			hpfs_brelse4(&qbh);
+			return 0;
+		}
+		de = dnode_last_de(dnode);
+		if (!de || !de->down) {
+			hpfs_error(i->i_sb, "move_to_top: dnode %08x doesn't point down to %08x", up, dno);
+			hpfs_brelse4(&qbh);
+			return 0;
+		}
+		le32_add_cpu(&dnode->first_free, -4);
+		le16_add_cpu(&de->length, -4);
+		de->down = 0;
+		hpfs_mark_4buffers_dirty(&qbh);
+		dno = up;
+	}
+	t = get_pos(dnode, de);
+	for_all_poss(i, hpfs_pos_subst, t, 4);
+	for_all_poss(i, hpfs_pos_subst, t + 1, 5);
+	if (!(nde = kmalloc(le16_to_cpu(de->length), GFP_NOFS))) {
+		hpfs_error(i->i_sb, "out of memory for dirent - directory will be corrupted");
+		hpfs_brelse4(&qbh);
+		return 0;
+	}
+	memcpy(nde, de, le16_to_cpu(de->length));
+	ddno = de->down ? de_down_pointer(de) : 0;
+	hpfs_delete_de(i->i_sb, dnode, de);
+	set_last_pointer(i->i_sb, dnode, ddno);
+	hpfs_mark_4buffers_dirty(&qbh);
+	hpfs_brelse4(&qbh);
+	a = hpfs_add_to_dnode(i, to, nde->name, nde->namelen, nde, from);
+	kfree(nde);
+	if (a) return 0;
+	return dno;
+}
+
+/* 
+ * Check if a dnode is empty and delete it from the tree
+ * (chkdsk doesn't like empty dnodes)
+ */
+
+static void delete_empty_dnode(struct inode *i, dnode_secno dno)
+{
+	struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
+	struct quad_buffer_head qbh;
+	struct dnode *dnode;
+	dnode_secno down, up, ndown;
+	int p;
+	struct hpfs_dirent *de;
+	int c1, c2 = 0;
+	try_it_again:
+	if (hpfs_stop_cycles(i->i_sb, dno, &c1, &c2, "delete_empty_dnode")) return;
+	if (!(dnode = hpfs_map_dnode(i->i_sb, dno, &qbh))) return;
+	if (le32_to_cpu(dnode->first_free) > 56) goto end;
+	if (le32_to_cpu(dnode->first_free) == 52 || le32_to_cpu(dnode->first_free) == 56) {
+		struct hpfs_dirent *de_end;
+		int root = dnode->root_dnode;
+		up = le32_to_cpu(dnode->up);
+		de = dnode_first_de(dnode);
+		down = de->down ? de_down_pointer(de) : 0;
+		if (hpfs_sb(i->i_sb)->sb_chk) if (root && !down) {
+			hpfs_error(i->i_sb, "delete_empty_dnode: root dnode %08x is empty", dno);
+			goto end;
+		}
+		hpfs_brelse4(&qbh);
+		hpfs_free_dnode(i->i_sb, dno);
+		i->i_size -= 2048;
+		i->i_blocks -= 4;
+		if (root) {
+			struct fnode *fnode;
+			struct buffer_head *bh;
+			struct dnode *d1;
+			struct quad_buffer_head qbh1;
+			if (hpfs_sb(i->i_sb)->sb_chk)
+				if (up != i->i_ino) {
+					hpfs_error(i->i_sb,
+						   "bad pointer to fnode, dnode %08x, pointing to %08x, should be %08llx",
+						   dno, up,
+						   i->i_ino);
+					return;
+				}
+			if ((d1 = hpfs_map_dnode(i->i_sb, down, &qbh1))) {
+				d1->up = cpu_to_le32(up);
+				d1->root_dnode = 1;
+				hpfs_mark_4buffers_dirty(&qbh1);
+				hpfs_brelse4(&qbh1);
+			}
+			if ((fnode = hpfs_map_fnode(i->i_sb, up, &bh))) {
+				fnode->u.external[0].disk_secno = cpu_to_le32(down);
+				mark_buffer_dirty(bh);
+				brelse(bh);
+			}
+			hpfs_inode->i_dno = down;
+			for_all_poss(i, hpfs_pos_subst, ((loff_t)dno << 4) | 1, (loff_t) 12);
+			return;
+		}
+		if (!(dnode = hpfs_map_dnode(i->i_sb, up, &qbh))) return;
+		p = 1;
+		de_end = dnode_end_de(dnode);
+		for (de = dnode_first_de(dnode); de < de_end; de = de_next_de(de), p++)
+			if (de->down) if (de_down_pointer(de) == dno) goto fnd;
+		hpfs_error(i->i_sb, "delete_empty_dnode: pointer to dnode %08x not found in dnode %08x", dno, up);
+		goto end;
+		fnd:
+		for_all_poss(i, hpfs_pos_subst, ((loff_t)dno << 4) | 1, ((loff_t)up << 4) | p);
+		if (!down) {
+			de->down = 0;
+			le16_add_cpu(&de->length, -4);
+			le32_add_cpu(&dnode->first_free, -4);
+			memmove(de_next_de(de), (char *)de_next_de(de) + 4,
+				(char *)dnode + le32_to_cpu(dnode->first_free) - (char *)de_next_de(de));
+		} else {
+			struct dnode *d1;
+			struct quad_buffer_head qbh1;
+			*(dnode_secno *) ((void *) de + le16_to_cpu(de->length) - 4) = down;
+			if ((d1 = hpfs_map_dnode(i->i_sb, down, &qbh1))) {
+				d1->up = cpu_to_le32(up);
+				hpfs_mark_4buffers_dirty(&qbh1);
+				hpfs_brelse4(&qbh1);
+			}
+		}
+	} else {
+		hpfs_error(i->i_sb, "delete_empty_dnode: dnode %08x, first_free == %03x", dno, le32_to_cpu(dnode->first_free));
+		goto end;
+	}
+
+	if (!de->last) {
+		struct hpfs_dirent *de_next = de_next_de(de);
+		struct hpfs_dirent *de_cp;
+		struct dnode *d1;
+		struct quad_buffer_head qbh1;
+		if (!de_next->down) goto endm;
+		ndown = de_down_pointer(de_next);
+		if (!(de_cp = kmalloc(le16_to_cpu(de->length), GFP_NOFS))) {
+			pr_err("out of memory for dtree balancing\n");
+			goto endm;
+		}
+		memcpy(de_cp, de, le16_to_cpu(de->length));
+		hpfs_delete_de(i->i_sb, dnode, de);
+		hpfs_mark_4buffers_dirty(&qbh);
+		hpfs_brelse4(&qbh);
+		for_all_poss(i, hpfs_pos_subst, ((loff_t)up << 4) | p, 4);
+		for_all_poss(i, hpfs_pos_del, ((loff_t)up << 4) | p, 1);
+		if (de_cp->down) if ((d1 = hpfs_map_dnode(i->i_sb, de_down_pointer(de_cp), &qbh1))) {
+			d1->up = cpu_to_le32(ndown);
+			hpfs_mark_4buffers_dirty(&qbh1);
+			hpfs_brelse4(&qbh1);
+		}
+		hpfs_add_to_dnode(i, ndown, de_cp->name, de_cp->namelen, de_cp, de_cp->down ? de_down_pointer(de_cp) : 0);
+		/*pr_info("UP-TO-DNODE: %08x (ndown = %08x, down = %08x, dno = %08x)\n",
+		  up, ndown, down, dno);*/
+		dno = up;
+		kfree(de_cp);
+		goto try_it_again;
+	} else {
+		struct hpfs_dirent *de_prev = dnode_pre_last_de(dnode);
+		struct hpfs_dirent *de_cp;
+		struct dnode *d1;
+		struct quad_buffer_head qbh1;
+		dnode_secno dlp;
+		if (!de_prev) {
+			hpfs_error(i->i_sb, "delete_empty_dnode: empty dnode %08x", up);
+			hpfs_mark_4buffers_dirty(&qbh);
+			hpfs_brelse4(&qbh);
+			dno = up;
+			goto try_it_again;
+		}
+		if (!de_prev->down) goto endm;
+		ndown = de_down_pointer(de_prev);
+		if ((d1 = hpfs_map_dnode(i->i_sb, ndown, &qbh1))) {
+			struct hpfs_dirent *del = dnode_last_de(d1);
+			dlp = del->down ? de_down_pointer(del) : 0;
+			if (!dlp && down) {
+				if (le32_to_cpu(d1->first_free) > 2044) {
+					if (hpfs_sb(i->i_sb)->sb_chk >= 2) {
+						pr_err("unbalanced dnode tree, see hpfs.txt 4 more info\n");
+						pr_err("terminating balancing operation\n");
+					}
+					hpfs_brelse4(&qbh1);
+					goto endm;
+				}
+				if (hpfs_sb(i->i_sb)->sb_chk >= 2) {
+					pr_err("unbalanced dnode tree, see hpfs.txt 4 more info\n");
+					pr_err("goin'on\n");
+				}
+				le16_add_cpu(&del->length, 4);
+				del->down = 1;
+				le32_add_cpu(&d1->first_free, 4);
+			}
+			if (dlp && !down) {
+				le16_add_cpu(&del->length, -4);
+				del->down = 0;
+				le32_add_cpu(&d1->first_free, -4);
+			} else if (down)
+				*(__le32 *) ((void *) del + le16_to_cpu(del->length) - 4) = cpu_to_le32(down);
+		} else goto endm;
+		if (!(de_cp = kmalloc(le16_to_cpu(de_prev->length), GFP_NOFS))) {
+			pr_err("out of memory for dtree balancing\n");
+			hpfs_brelse4(&qbh1);
+			goto endm;
+		}
+		hpfs_mark_4buffers_dirty(&qbh1);
+		hpfs_brelse4(&qbh1);
+		memcpy(de_cp, de_prev, le16_to_cpu(de_prev->length));
+		hpfs_delete_de(i->i_sb, dnode, de_prev);
+		if (!de_prev->down) {
+			le16_add_cpu(&de_prev->length, 4);
+			de_prev->down = 1;
+			le32_add_cpu(&dnode->first_free, 4);
+		}
+		*(__le32 *) ((void *) de_prev + le16_to_cpu(de_prev->length) - 4) = cpu_to_le32(ndown);
+		hpfs_mark_4buffers_dirty(&qbh);
+		hpfs_brelse4(&qbh);
+		for_all_poss(i, hpfs_pos_subst, ((loff_t)up << 4) | (p - 1), 4);
+		for_all_poss(i, hpfs_pos_subst, ((loff_t)up << 4) | p, ((loff_t)up << 4) | (p - 1));
+		if (down) if ((d1 = hpfs_map_dnode(i->i_sb, de_down_pointer(de), &qbh1))) {
+			d1->up = cpu_to_le32(ndown);
+			hpfs_mark_4buffers_dirty(&qbh1);
+			hpfs_brelse4(&qbh1);
+		}
+		hpfs_add_to_dnode(i, ndown, de_cp->name, de_cp->namelen, de_cp, dlp);
+		dno = up;
+		kfree(de_cp);
+		goto try_it_again;
+	}
+	endm:
+	hpfs_mark_4buffers_dirty(&qbh);
+	end:
+	hpfs_brelse4(&qbh);
+}
+
+
+/* Delete dirent from directory */
+
+int hpfs_remove_dirent(struct inode *i, dnode_secno dno, struct hpfs_dirent *de,
+		       struct quad_buffer_head *qbh, int depth)
+{
+	struct dnode *dnode = qbh->data;
+	dnode_secno down = 0;
+	loff_t t;
+	if (de->first || de->last) {
+		hpfs_error(i->i_sb, "hpfs_remove_dirent: attempt to delete first or last dirent in dnode %08x", dno);
+		hpfs_brelse4(qbh);
+		return 1;
+	}
+	if (de->down) down = de_down_pointer(de);
+	if (depth && (de->down || (de == dnode_first_de(dnode) && de_next_de(de)->last))) {
+		if (hpfs_check_free_dnodes(i->i_sb, FREE_DNODES_DEL)) {
+			hpfs_brelse4(qbh);
+			return 2;
+		}
+	}
+	for_all_poss(i, hpfs_pos_del, (t = get_pos(dnode, de)) + 1, 1);
+	hpfs_delete_de(i->i_sb, dnode, de);
+	hpfs_mark_4buffers_dirty(qbh);
+	hpfs_brelse4(qbh);
+	if (down) {
+		dnode_secno a = move_to_top(i, down, dno);
+		for_all_poss(i, hpfs_pos_subst, 5, t);
+		if (a) delete_empty_dnode(i, a);
+		return !a;
+	}
+	delete_empty_dnode(i, dno);
+	return 0;
+}
+
+void hpfs_count_dnodes(struct super_block *s, dnode_secno dno, int *n_dnodes,
+		       int *n_subdirs, int *n_items)
+{
+	struct dnode *dnode;
+	struct quad_buffer_head qbh;
+	struct hpfs_dirent *de;
+	dnode_secno ptr, odno = 0;
+	int c1, c2 = 0;
+	int d1, d2 = 0;
+	go_down:
+	if (n_dnodes) (*n_dnodes)++;
+	if (hpfs_sb(s)->sb_chk)
+		if (hpfs_stop_cycles(s, dno, &c1, &c2, "hpfs_count_dnodes #1")) return;
+	ptr = 0;
+	go_up:
+	if (!(dnode = hpfs_map_dnode(s, dno, &qbh))) return;
+	if (hpfs_sb(s)->sb_chk) if (odno && odno != -1 && le32_to_cpu(dnode->up) != odno)
+		hpfs_error(s, "hpfs_count_dnodes: bad up pointer; dnode %08x, down %08x points to %08x", odno, dno, le32_to_cpu(dnode->up));
+	de = dnode_first_de(dnode);
+	if (ptr) while(1) {
+		if (de->down) if (de_down_pointer(de) == ptr) goto process_de;
+		if (de->last) {
+			hpfs_brelse4(&qbh);
+			hpfs_error(s, "hpfs_count_dnodes: pointer to dnode %08x not found in dnode %08x, got here from %08x",
+				ptr, dno, odno);
+			return;
+		}
+		de = de_next_de(de);
+	}
+	next_de:
+	if (de->down) {
+		odno = dno;
+		dno = de_down_pointer(de);
+		hpfs_brelse4(&qbh);
+		goto go_down;
+	}
+	process_de:
+	if (!de->first && !de->last && de->directory && n_subdirs) (*n_subdirs)++;
+	if (!de->first && !de->last && n_items) (*n_items)++;
+	if ((de = de_next_de(de)) < dnode_end_de(dnode)) goto next_de;
+	ptr = dno;
+	dno = le32_to_cpu(dnode->up);
+	if (dnode->root_dnode) {
+		hpfs_brelse4(&qbh);
+		return;
+	}
+	hpfs_brelse4(&qbh);
+	if (hpfs_sb(s)->sb_chk)
+		if (hpfs_stop_cycles(s, ptr, &d1, &d2, "hpfs_count_dnodes #2")) return;
+	odno = -1;
+	goto go_up;
+}
+
+static struct hpfs_dirent *map_nth_dirent(struct super_block *s, dnode_secno dno, int n,
+					  struct quad_buffer_head *qbh, struct dnode **dn)
+{
+	int i;
+	struct hpfs_dirent *de, *de_end;
+	struct dnode *dnode;
+	dnode = hpfs_map_dnode(s, dno, qbh);
+	if (!dnode) return NULL;
+	if (dn) *dn=dnode;
+	de = dnode_first_de(dnode);
+	de_end = dnode_end_de(dnode);
+	for (i = 1; de < de_end; i++, de = de_next_de(de)) {
+		if (i == n) {
+			return de;
+		}	
+		if (de->last) break;
+	}
+	hpfs_brelse4(qbh);
+	hpfs_error(s, "map_nth_dirent: n too high; dnode = %08x, requested %08x", dno, n);
+	return NULL;
+}
+
+dnode_secno hpfs_de_as_down_as_possible(struct super_block *s, dnode_secno dno)
+{
+	struct quad_buffer_head qbh;
+	dnode_secno d = dno;
+	dnode_secno up = 0;
+	struct hpfs_dirent *de;
+	int c1, c2 = 0;
+
+	again:
+	if (hpfs_sb(s)->sb_chk)
+		if (hpfs_stop_cycles(s, d, &c1, &c2, "hpfs_de_as_down_as_possible"))
+			return d;
+	if (!(de = map_nth_dirent(s, d, 1, &qbh, NULL))) return dno;
+	if (hpfs_sb(s)->sb_chk)
+		if (up && le32_to_cpu(((struct dnode *)qbh.data)->up) != up)
+			hpfs_error(s, "hpfs_de_as_down_as_possible: bad up pointer; dnode %08x, down %08x points to %08x", up, d, le32_to_cpu(((struct dnode *)qbh.data)->up));
+	if (!de->down) {
+		hpfs_brelse4(&qbh);
+		return d;
+	}
+	up = d;
+	d = de_down_pointer(de);
+	hpfs_brelse4(&qbh);
+	goto again;
+}
+
+struct hpfs_dirent *map_pos_dirent(struct inode *inode, loff_t *posp,
+				   struct quad_buffer_head *qbh)
+{
+	loff_t pos;
+	unsigned c;
+	dnode_secno dno;
+	struct hpfs_dirent *de, *d;
+	struct hpfs_dirent *up_de;
+	struct hpfs_dirent *end_up_de;
+	struct dnode *dnode;
+	struct dnode *up_dnode;
+	struct quad_buffer_head qbh0;
+
+	pos = *posp;
+	dno = pos >> 6 << 2;
+	pos &= 077;
+	if (!(de = map_nth_dirent(inode->i_sb, dno, pos, qbh, &dnode)))
+		goto bail;
+
+	/* Going to the next dirent */
+	if ((d = de_next_de(de)) < dnode_end_de(dnode)) {
+		if (!(++*posp & 077)) {
+			hpfs_error(inode->i_sb,
+				"map_pos_dirent: pos crossed dnode boundary; pos = %08llx",
+				(unsigned long long)*posp);
+			goto bail;
+		}
+		/* We're going down the tree */
+		if (d->down) {
+			*posp = ((loff_t) hpfs_de_as_down_as_possible(inode->i_sb, de_down_pointer(d)) << 4) + 1;
+		}
+	
+		return de;
+	}
+
+	/* Going up */
+	if (dnode->root_dnode) goto bail;
+
+	if (!(up_dnode = hpfs_map_dnode(inode->i_sb, le32_to_cpu(dnode->up), &qbh0)))
+		goto bail;
+
+	end_up_de = dnode_end_de(up_dnode);
+	c = 0;
+	for (up_de = dnode_first_de(up_dnode); up_de < end_up_de;
+	     up_de = de_next_de(up_de)) {
+		if (!(++c & 077)) hpfs_error(inode->i_sb,
+			"map_pos_dirent: pos crossed dnode boundary; dnode = %08x", le32_to_cpu(dnode->up));
+		if (up_de->down && de_down_pointer(up_de) == dno) {
+			*posp = ((loff_t) le32_to_cpu(dnode->up) << 4) + c;
+			hpfs_brelse4(&qbh0);
+			return de;
+		}
+	}
+	
+	hpfs_error(inode->i_sb, "map_pos_dirent: pointer to dnode %08x not found in parent dnode %08x",
+		dno, le32_to_cpu(dnode->up));
+	hpfs_brelse4(&qbh0);
+	
+	bail:
+	*posp = 12;
+	return de;
+}
+
+/* Find a dirent in tree */
+
+struct hpfs_dirent *map_dirent(struct inode *inode, dnode_secno dno,
+			       const unsigned char *name, unsigned len,
+			       dnode_secno *dd, struct quad_buffer_head *qbh)
+{
+	struct dnode *dnode;
+	struct hpfs_dirent *de;
+	struct hpfs_dirent *de_end;
+	int c1, c2 = 0;
+
+	if (!S_ISDIR(inode->i_mode)) hpfs_error(inode->i_sb, "map_dirent: not a directory\n");
+	again:
+	if (hpfs_sb(inode->i_sb)->sb_chk)
+		if (hpfs_stop_cycles(inode->i_sb, dno, &c1, &c2, "map_dirent")) return NULL;
+	if (!(dnode = hpfs_map_dnode(inode->i_sb, dno, qbh))) return NULL;
+	
+	de_end = dnode_end_de(dnode);
+	for (de = dnode_first_de(dnode); de < de_end; de = de_next_de(de)) {
+		int t = hpfs_compare_names(inode->i_sb, name, len, de->name, de->namelen, de->last);
+		if (!t) {
+			if (dd) *dd = dno;
+			return de;
+		}
+		if (t < 0) {
+			if (de->down) {
+				dno = de_down_pointer(de);
+				hpfs_brelse4(qbh);
+				goto again;
+			}
+		break;
+		}
+	}
+	hpfs_brelse4(qbh);
+	return NULL;
+}
+
+/*
+ * Remove empty directory. In normal cases it is only one dnode with two
+ * entries, but we must handle also such obscure cases when it's a tree
+ * of empty dnodes.
+ */
+
+void hpfs_remove_dtree(struct super_block *s, dnode_secno dno)
+{
+	struct quad_buffer_head qbh;
+	struct dnode *dnode;
+	struct hpfs_dirent *de;
+	dnode_secno d1, d2, rdno = dno;
+	while (1) {
+		if (!(dnode = hpfs_map_dnode(s, dno, &qbh))) return;
+		de = dnode_first_de(dnode);
+		if (de->last) {
+			if (de->down) d1 = de_down_pointer(de);
+			else goto error;
+			hpfs_brelse4(&qbh);
+			hpfs_free_dnode(s, dno);
+			dno = d1;
+		} else break;
+	}
+	if (!de->first) goto error;
+	d1 = de->down ? de_down_pointer(de) : 0;
+	de = de_next_de(de);
+	if (!de->last) goto error;
+	d2 = de->down ? de_down_pointer(de) : 0;
+	hpfs_brelse4(&qbh);
+	hpfs_free_dnode(s, dno);
+	do {
+		while (d1) {
+			if (!(dnode = hpfs_map_dnode(s, dno = d1, &qbh))) return;
+			de = dnode_first_de(dnode);
+			if (!de->last) goto error;
+			d1 = de->down ? de_down_pointer(de) : 0;
+			hpfs_brelse4(&qbh);
+			hpfs_free_dnode(s, dno);
+		}
+		d1 = d2;
+		d2 = 0;
+	} while (d1);
+	return;
+	error:
+	hpfs_brelse4(&qbh);
+	hpfs_free_dnode(s, dno);
+	hpfs_error(s, "directory %08x is corrupted or not empty", rdno);
+}
+
+/* 
+ * Find dirent for specified fnode. Use truncated 15-char name in fnode as
+ * a help for searching.
+ */
+
+struct hpfs_dirent *map_fnode_dirent(struct super_block *s, fnode_secno fno,
+				     struct fnode *f, struct quad_buffer_head *qbh)
+{
+	unsigned char *name1;
+	unsigned char *name2;
+	int name1len, name2len;
+	struct dnode *d;
+	dnode_secno dno, downd;
+	struct fnode *upf;
+	struct buffer_head *bh;
+	struct hpfs_dirent *de, *de_end;
+	int c;
+	int c1, c2 = 0;
+	int d1, d2 = 0;
+	name1 = f->name;
+	if (!(name2 = kmalloc(256, GFP_NOFS))) {
+		pr_err("out of memory, can't map dirent\n");
+		return NULL;
+	}
+	if (f->len <= 15)
+		memcpy(name2, name1, name1len = name2len = f->len);
+	else {
+		memcpy(name2, name1, 15);
+		memset(name2 + 15, 0xff, 256 - 15);
+		/*name2[15] = 0xff;*/
+		name1len = 15; name2len = 256;
+	}
+	if (!(upf = hpfs_map_fnode(s, le32_to_cpu(f->up), &bh))) {
+		kfree(name2);
+		return NULL;
+	}	
+	if (!fnode_is_dir(upf)) {
+		brelse(bh);
+		hpfs_error(s, "fnode %08x has non-directory parent %08x", fno, le32_to_cpu(f->up));
+		kfree(name2);
+		return NULL;
+	}
+	dno = le32_to_cpu(upf->u.external[0].disk_secno);
+	brelse(bh);
+	go_down:
+	downd = 0;
+	go_up:
+	if (!(d = hpfs_map_dnode(s, dno, qbh))) {
+		kfree(name2);
+		return NULL;
+	}
+	de_end = dnode_end_de(d);
+	de = dnode_first_de(d);
+	if (downd) {
+		while (de < de_end) {
+			if (de->down) if (de_down_pointer(de) == downd) goto f;
+			de = de_next_de(de);
+		}
+		hpfs_error(s, "pointer to dnode %08x not found in dnode %08x", downd, dno);
+		hpfs_brelse4(qbh);
+		kfree(name2);
+		return NULL;
+	}
+	next_de:
+	if (le32_to_cpu(de->fnode) == fno) {
+		kfree(name2);
+		return de;
+	}
+	c = hpfs_compare_names(s, name1, name1len, de->name, de->namelen, de->last);
+	if (c < 0 && de->down) {
+		dno = de_down_pointer(de);
+		hpfs_brelse4(qbh);
+		if (hpfs_sb(s)->sb_chk)
+			if (hpfs_stop_cycles(s, dno, &c1, &c2, "map_fnode_dirent #1")) {
+				kfree(name2);
+				return NULL;
+		}
+		goto go_down;
+	}
+	f:
+	if (le32_to_cpu(de->fnode) == fno) {
+		kfree(name2);
+		return de;
+	}
+	c = hpfs_compare_names(s, name2, name2len, de->name, de->namelen, de->last);
+	if (c < 0 && !de->last) goto not_found;
+	if ((de = de_next_de(de)) < de_end) goto next_de;
+	if (d->root_dnode) goto not_found;
+	downd = dno;
+	dno = le32_to_cpu(d->up);
+	hpfs_brelse4(qbh);
+	if (hpfs_sb(s)->sb_chk)
+		if (hpfs_stop_cycles(s, downd, &d1, &d2, "map_fnode_dirent #2")) {
+			kfree(name2);
+			return NULL;
+		}
+	goto go_up;
+	not_found:
+	hpfs_brelse4(qbh);
+	hpfs_error(s, "dirent for fnode %08x not found", fno);
+	kfree(name2);
+	return NULL;
+}
diff --git a/fs/hpfs/ea.c b/fs/hpfs/ea.c
new file mode 100644
index 000000000..4664f9ab0
--- /dev/null
+++ b/fs/hpfs/ea.c
@@ -0,0 +1,368 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/hpfs/ea.c
+ *
+ *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
+ *
+ *  handling extended attributes
+ */
+
+#include "hpfs_fn.h"
+
+/* Remove external extended attributes. ano specifies whether a is a 
+   direct sector where eas starts or an anode */
+
+void hpfs_ea_ext_remove(struct super_block *s, secno a, int ano, unsigned len)
+{
+	unsigned pos = 0;
+	while (pos < len) {
+		char ex[4 + 255 + 1 + 8];
+		struct extended_attribute *ea = (struct extended_attribute *)ex;
+		if (pos + 4 > len) {
+			hpfs_error(s, "EAs don't end correctly, %s %08x, len %08x",
+				ano ? "anode" : "sectors", a, len);
+			return;
+		}
+		if (hpfs_ea_read(s, a, ano, pos, 4, ex)) return;
+		if (ea_indirect(ea)) {
+			if (ea_valuelen(ea) != 8) {
+				hpfs_error(s, "ea_indirect(ea) set while ea->valuelen!=8, %s %08x, pos %08x",
+					ano ? "anode" : "sectors", a, pos);
+				return;
+			}
+			if (hpfs_ea_read(s, a, ano, pos + 4, ea->namelen + 9, ex+4))
+				return;
+			hpfs_ea_remove(s, ea_sec(ea), ea_in_anode(ea), ea_len(ea));
+		}
+		pos += ea->namelen + ea_valuelen(ea) + 5;
+	}
+	if (!ano) hpfs_free_sectors(s, a, (len+511) >> 9);
+	else {
+		struct buffer_head *bh;
+		struct anode *anode;
+		if ((anode = hpfs_map_anode(s, a, &bh))) {
+			hpfs_remove_btree(s, GET_BTREE_PTR(&anode->btree));
+			brelse(bh);
+			hpfs_free_sectors(s, a, 1);
+		}
+	}
+}
+
+static char *get_indirect_ea(struct super_block *s, int ano, secno a, int size)
+{
+	char *ret;
+	if (!(ret = kmalloc(size + 1, GFP_NOFS))) {
+		pr_err("out of memory for EA\n");
+		return NULL;
+	}
+	if (hpfs_ea_read(s, a, ano, 0, size, ret)) {
+		kfree(ret);
+		return NULL;
+	}
+	ret[size] = 0;
+	return ret;
+}
+
+static void set_indirect_ea(struct super_block *s, int ano, secno a,
+			    const char *data, int size)
+{
+	hpfs_ea_write(s, a, ano, 0, size, data);
+}
+
+/* Read an extended attribute named 'key' into the provided buffer */
+
+int hpfs_read_ea(struct super_block *s, struct fnode *fnode, char *key,
+		char *buf, int size)
+{
+	unsigned pos;
+	int ano, len;
+	secno a;
+	char ex[4 + 255 + 1 + 8];
+	struct extended_attribute *ea;
+	struct extended_attribute *ea_end = fnode_end_ea(fnode);
+	for (ea = fnode_ea(fnode); ea < ea_end; ea = next_ea(ea))
+		if (!strcmp(ea->name, key)) {
+			if (ea_indirect(ea))
+				goto indirect;
+			if (ea_valuelen(ea) >= size)
+				return -EINVAL;
+			memcpy(buf, ea_data(ea), ea_valuelen(ea));
+			buf[ea_valuelen(ea)] = 0;
+			return 0;
+		}
+	a = le32_to_cpu(fnode->ea_secno);
+	len = le32_to_cpu(fnode->ea_size_l);
+	ano = fnode_in_anode(fnode);
+	pos = 0;
+	while (pos < len) {
+		ea = (struct extended_attribute *)ex;
+		if (pos + 4 > len) {
+			hpfs_error(s, "EAs don't end correctly, %s %08x, len %08x",
+				ano ? "anode" : "sectors", a, len);
+			return -EIO;
+		}
+		if (hpfs_ea_read(s, a, ano, pos, 4, ex)) return -EIO;
+		if (hpfs_ea_read(s, a, ano, pos + 4, ea->namelen + 1 + (ea_indirect(ea) ? 8 : 0), ex + 4))
+			return -EIO;
+		if (!strcmp(ea->name, key)) {
+			if (ea_indirect(ea))
+				goto indirect;
+			if (ea_valuelen(ea) >= size)
+				return -EINVAL;
+			if (hpfs_ea_read(s, a, ano, pos + 4 + ea->namelen + 1, ea_valuelen(ea), buf))
+				return -EIO;
+			buf[ea_valuelen(ea)] = 0;
+			return 0;
+		}
+		pos += ea->namelen + ea_valuelen(ea) + 5;
+	}
+	return -ENOENT;
+indirect:
+	if (ea_len(ea) >= size)
+		return -EINVAL;
+	if (hpfs_ea_read(s, ea_sec(ea), ea_in_anode(ea), 0, ea_len(ea), buf))
+		return -EIO;
+	buf[ea_len(ea)] = 0;
+	return 0;
+}
+
+/* Read an extended attribute named 'key' */
+char *hpfs_get_ea(struct super_block *s, struct fnode *fnode, char *key, int *size)
+{
+	char *ret;
+	unsigned pos;
+	int ano, len;
+	secno a;
+	struct extended_attribute *ea;
+	struct extended_attribute *ea_end = fnode_end_ea(fnode);
+	for (ea = fnode_ea(fnode); ea < ea_end; ea = next_ea(ea))
+		if (!strcmp(ea->name, key)) {
+			if (ea_indirect(ea))
+				return get_indirect_ea(s, ea_in_anode(ea), ea_sec(ea), *size = ea_len(ea));
+			if (!(ret = kmalloc((*size = ea_valuelen(ea)) + 1, GFP_NOFS))) {
+				pr_err("out of memory for EA\n");
+				return NULL;
+			}
+			memcpy(ret, ea_data(ea), ea_valuelen(ea));
+			ret[ea_valuelen(ea)] = 0;
+			return ret;
+		}
+	a = le32_to_cpu(fnode->ea_secno);
+	len = le32_to_cpu(fnode->ea_size_l);
+	ano = fnode_in_anode(fnode);
+	pos = 0;
+	while (pos < len) {
+		char ex[4 + 255 + 1 + 8];
+		ea = (struct extended_attribute *)ex;
+		if (pos + 4 > len) {
+			hpfs_error(s, "EAs don't end correctly, %s %08x, len %08x",
+				ano ? "anode" : "sectors", a, len);
+			return NULL;
+		}
+		if (hpfs_ea_read(s, a, ano, pos, 4, ex)) return NULL;
+		if (hpfs_ea_read(s, a, ano, pos + 4, ea->namelen + 1 + (ea_indirect(ea) ? 8 : 0), ex + 4))
+			return NULL;
+		if (!strcmp(ea->name, key)) {
+			if (ea_indirect(ea))
+				return get_indirect_ea(s, ea_in_anode(ea), ea_sec(ea), *size = ea_len(ea));
+			if (!(ret = kmalloc((*size = ea_valuelen(ea)) + 1, GFP_NOFS))) {
+				pr_err("out of memory for EA\n");
+				return NULL;
+			}
+			if (hpfs_ea_read(s, a, ano, pos + 4 + ea->namelen + 1, ea_valuelen(ea), ret)) {
+				kfree(ret);
+				return NULL;
+			}
+			ret[ea_valuelen(ea)] = 0;
+			return ret;
+		}
+		pos += ea->namelen + ea_valuelen(ea) + 5;
+	}
+	return NULL;
+}
+
+/* 
+ * Update or create extended attribute 'key' with value 'data'. Note that
+ * when this ea exists, it MUST have the same size as size of data.
+ * This driver can't change sizes of eas ('cause I just don't need it).
+ */
+
+void hpfs_set_ea(struct inode *inode, struct fnode *fnode, const char *key,
+		 const char *data, int size)
+{
+	fnode_secno fno = inode->i_ino;
+	struct super_block *s = inode->i_sb;
+	unsigned pos;
+	int ano, len;
+	secno a;
+	unsigned char h[4];
+	struct extended_attribute *ea;
+	struct extended_attribute *ea_end = fnode_end_ea(fnode);
+	for (ea = fnode_ea(fnode); ea < ea_end; ea = next_ea(ea))
+		if (!strcmp(ea->name, key)) {
+			if (ea_indirect(ea)) {
+				if (ea_len(ea) == size)
+					set_indirect_ea(s, ea_in_anode(ea), ea_sec(ea), data, size);
+			} else if (ea_valuelen(ea) == size) {
+				memcpy(ea_data(ea), data, size);
+			}
+			return;
+		}
+	a = le32_to_cpu(fnode->ea_secno);
+	len = le32_to_cpu(fnode->ea_size_l);
+	ano = fnode_in_anode(fnode);
+	pos = 0;
+	while (pos < len) {
+		char ex[4 + 255 + 1 + 8];
+		ea = (struct extended_attribute *)ex;
+		if (pos + 4 > len) {
+			hpfs_error(s, "EAs don't end correctly, %s %08x, len %08x",
+				ano ? "anode" : "sectors", a, len);
+			return;
+		}
+		if (hpfs_ea_read(s, a, ano, pos, 4, ex)) return;
+		if (hpfs_ea_read(s, a, ano, pos + 4, ea->namelen + 1 + (ea_indirect(ea) ? 8 : 0), ex + 4))
+			return;
+		if (!strcmp(ea->name, key)) {
+			if (ea_indirect(ea)) {
+				if (ea_len(ea) == size)
+					set_indirect_ea(s, ea_in_anode(ea), ea_sec(ea), data, size);
+			}
+			else {
+				if (ea_valuelen(ea) == size)
+					hpfs_ea_write(s, a, ano, pos + 4 + ea->namelen + 1, size, data);
+			}
+			return;
+		}
+		pos += ea->namelen + ea_valuelen(ea) + 5;
+	}
+	if (!le16_to_cpu(fnode->ea_offs)) {
+		/*if (le16_to_cpu(fnode->ea_size_s)) {
+			hpfs_error(s, "fnode %08x: ea_size_s == %03x, ea_offs == 0",
+				inode->i_ino, le16_to_cpu(fnode->ea_size_s));
+			return;
+		}*/
+		fnode->ea_offs = cpu_to_le16(0xc4);
+	}
+	if (le16_to_cpu(fnode->ea_offs) < 0xc4 || le16_to_cpu(fnode->ea_offs) + le16_to_cpu(fnode->acl_size_s) + le16_to_cpu(fnode->ea_size_s) > 0x200) {
+		hpfs_error(s, "fnode %08llx: ea_offs == %03x, ea_size_s == %03x",
+			inode->i_ino,
+			le16_to_cpu(fnode->ea_offs), le16_to_cpu(fnode->ea_size_s));
+		return;
+	}
+	if ((le16_to_cpu(fnode->ea_size_s) || !le32_to_cpu(fnode->ea_size_l)) &&
+	     le16_to_cpu(fnode->ea_offs) + le16_to_cpu(fnode->acl_size_s) + le16_to_cpu(fnode->ea_size_s) + strlen(key) + size + 5 <= 0x200) {
+		ea = fnode_end_ea(fnode);
+		*(char *)ea = 0;
+		ea->namelen = strlen(key);
+		ea->valuelen_lo = size;
+		ea->valuelen_hi = size >> 8;
+		strcpy(ea->name, key);
+		memcpy(ea_data(ea), data, size);
+		fnode->ea_size_s = cpu_to_le16(le16_to_cpu(fnode->ea_size_s) + strlen(key) + size + 5);
+		goto ret;
+	}
+	/* Most the code here is 99.9993422% unused. I hope there are no bugs.
+	   But what .. HPFS.IFS has also bugs in ea management. */
+	if (le16_to_cpu(fnode->ea_size_s) && !le32_to_cpu(fnode->ea_size_l)) {
+		secno n;
+		struct buffer_head *bh;
+		char *data;
+		if (!(n = hpfs_alloc_sector(s, fno, 1, 0))) return;
+		if (!(data = hpfs_get_sector(s, n, &bh))) {
+			hpfs_free_sectors(s, n, 1);
+			return;
+		}
+		memcpy(data, fnode_ea(fnode), le16_to_cpu(fnode->ea_size_s));
+		fnode->ea_size_l = cpu_to_le32(le16_to_cpu(fnode->ea_size_s));
+		fnode->ea_size_s = cpu_to_le16(0);
+		fnode->ea_secno = cpu_to_le32(n);
+		fnode->flags &= ~FNODE_anode;
+		mark_buffer_dirty(bh);
+		brelse(bh);
+	}
+	pos = le32_to_cpu(fnode->ea_size_l) + 5 + strlen(key) + size;
+	len = (le32_to_cpu(fnode->ea_size_l) + 511) >> 9;
+	if (pos >= 30000) goto bail;
+	while (((pos + 511) >> 9) > len) {
+		if (!len) {
+			secno q = hpfs_alloc_sector(s, fno, 1, 0);
+			if (!q) goto bail;
+			fnode->ea_secno = cpu_to_le32(q);
+			fnode->flags &= ~FNODE_anode;
+			len++;
+		} else if (!fnode_in_anode(fnode)) {
+			if (hpfs_alloc_if_possible(s, le32_to_cpu(fnode->ea_secno) + len)) {
+				len++;
+			} else {
+				/* Aargh... don't know how to create ea anodes :-( */
+				/*struct buffer_head *bh;
+				struct anode *anode;
+				anode_secno a_s;
+				if (!(anode = hpfs_alloc_anode(s, fno, &a_s, &bh)))
+					goto bail;
+				anode->up = cpu_to_le32(fno);
+				anode->btree.fnode_parent = 1;
+				anode->btree.n_free_nodes--;
+				anode->btree.n_used_nodes++;
+				anode->btree.first_free = cpu_to_le16(le16_to_cpu(anode->btree.first_free) + 12);
+				anode->u.external[0].disk_secno = cpu_to_le32(le32_to_cpu(fnode->ea_secno));
+				anode->u.external[0].file_secno = cpu_to_le32(0);
+				anode->u.external[0].length = cpu_to_le32(len);
+				mark_buffer_dirty(bh);
+				brelse(bh);
+				fnode->flags |= FNODE_anode;
+				fnode->ea_secno = cpu_to_le32(a_s);*/
+				secno new_sec;
+				int i;
+				if (!(new_sec = hpfs_alloc_sector(s, fno, 1, 1 - ((pos + 511) >> 9))))
+					goto bail;
+				for (i = 0; i < len; i++) {
+					struct buffer_head *bh1, *bh2;
+					void *b1, *b2;
+					if (!(b1 = hpfs_map_sector(s, le32_to_cpu(fnode->ea_secno) + i, &bh1, len - i - 1))) {
+						hpfs_free_sectors(s, new_sec, (pos + 511) >> 9);
+						goto bail;
+					}
+					if (!(b2 = hpfs_get_sector(s, new_sec + i, &bh2))) {
+						brelse(bh1);
+						hpfs_free_sectors(s, new_sec, (pos + 511) >> 9);
+						goto bail;
+					}
+					memcpy(b2, b1, 512);
+					brelse(bh1);
+					mark_buffer_dirty(bh2);
+					brelse(bh2);
+				}
+				hpfs_free_sectors(s, le32_to_cpu(fnode->ea_secno), len);
+				fnode->ea_secno = cpu_to_le32(new_sec);
+				len = (pos + 511) >> 9;
+			}
+		}
+		if (fnode_in_anode(fnode)) {
+			if (hpfs_add_sector_to_btree(s, le32_to_cpu(fnode->ea_secno),
+						     0, len) != -1) {
+				len++;
+			} else {
+				goto bail;
+			}
+		}
+	}
+	h[0] = 0;
+	h[1] = strlen(key);
+	h[2] = size & 0xff;
+	h[3] = size >> 8;
+	if (hpfs_ea_write(s, le32_to_cpu(fnode->ea_secno), fnode_in_anode(fnode), le32_to_cpu(fnode->ea_size_l), 4, h)) goto bail;
+	if (hpfs_ea_write(s, le32_to_cpu(fnode->ea_secno), fnode_in_anode(fnode), le32_to_cpu(fnode->ea_size_l) + 4, h[1] + 1, key)) goto bail;
+	if (hpfs_ea_write(s, le32_to_cpu(fnode->ea_secno), fnode_in_anode(fnode), le32_to_cpu(fnode->ea_size_l) + 5 + h[1], size, data)) goto bail;
+	fnode->ea_size_l = cpu_to_le32(pos);
+	ret:
+	hpfs_i(inode)->i_ea_size += 5 + strlen(key) + size;
+	return;
+	bail:
+	if (le32_to_cpu(fnode->ea_secno))
+		if (fnode_in_anode(fnode)) hpfs_truncate_btree(s, le32_to_cpu(fnode->ea_secno), 1, (le32_to_cpu(fnode->ea_size_l) + 511) >> 9);
+		else hpfs_free_sectors(s, le32_to_cpu(fnode->ea_secno) + ((le32_to_cpu(fnode->ea_size_l) + 511) >> 9), len - ((le32_to_cpu(fnode->ea_size_l) + 511) >> 9));
+	else fnode->ea_secno = fnode->ea_size_l = cpu_to_le32(0);
+}
+	
diff --git a/fs/hpfs/file.c b/fs/hpfs/file.c
new file mode 100644
index 000000000..6a629ab95
--- /dev/null
+++ b/fs/hpfs/file.c
@@ -0,0 +1,276 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/hpfs/file.c
+ *
+ *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
+ *
+ *  file VFS functions
+ */
+
+#include "hpfs_fn.h"
+#include <linux/mpage.h>
+#include <linux/iomap.h>
+#include <linux/fiemap.h>
+
+#define BLOCKS(size) (((size) + 511) >> 9)
+
+static int hpfs_file_release(struct inode *inode, struct file *file)
+{
+	hpfs_lock(inode->i_sb);
+	hpfs_write_if_changed(inode);
+	hpfs_unlock(inode->i_sb);
+	return 0;
+}
+
+int hpfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
+{
+	struct inode *inode = file->f_mapping->host;
+	int ret;
+
+	ret = file_write_and_wait_range(file, start, end);
+	if (ret)
+		return ret;
+	return sync_blockdev(inode->i_sb->s_bdev);
+}
+
+/*
+ * generic_file_read often calls bmap with non-existing sector,
+ * so we must ignore such errors.
+ */
+
+static secno hpfs_bmap(struct inode *inode, unsigned file_secno, unsigned *n_secs)
+{
+	struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
+	unsigned n, disk_secno;
+	struct fnode *fnode;
+	struct buffer_head *bh;
+	if (BLOCKS(hpfs_i(inode)->mmu_private) <= file_secno) return 0;
+	n = file_secno - hpfs_inode->i_file_sec;
+	if (n < hpfs_inode->i_n_secs) {
+		*n_secs = hpfs_inode->i_n_secs - n;
+		return hpfs_inode->i_disk_sec + n;
+	}
+	if (!(fnode = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) return 0;
+	disk_secno = hpfs_bplus_lookup(inode->i_sb, inode,
+				       GET_BTREE_PTR(&fnode->btree),
+				       file_secno, bh);
+	if (disk_secno == -1) return 0;
+	if (hpfs_chk_sectors(inode->i_sb, disk_secno, 1, "bmap")) return 0;
+	n = file_secno - hpfs_inode->i_file_sec;
+	if (n < hpfs_inode->i_n_secs) {
+		*n_secs = hpfs_inode->i_n_secs - n;
+		return hpfs_inode->i_disk_sec + n;
+	}
+	*n_secs = 1;
+	return disk_secno;
+}
+
+void hpfs_truncate(struct inode *i)
+{
+	if (IS_IMMUTABLE(i)) return /*-EPERM*/;
+	hpfs_lock_assert(i->i_sb);
+
+	hpfs_i(i)->i_n_secs = 0;
+	i->i_blocks = 1 + ((i->i_size + 511) >> 9);
+	hpfs_i(i)->mmu_private = i->i_size;
+	hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9));
+	hpfs_write_inode(i);
+	hpfs_i(i)->i_n_secs = 0;
+}
+
+static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
+{
+	int r;
+	secno s;
+	unsigned n_secs;
+	hpfs_lock(inode->i_sb);
+	s = hpfs_bmap(inode, iblock, &n_secs);
+	if (s) {
+		if (bh_result->b_size >> 9 < n_secs)
+			n_secs = bh_result->b_size >> 9;
+		n_secs = hpfs_search_hotfix_map_for_range(inode->i_sb, s, n_secs);
+		if (unlikely(!n_secs)) {
+			s = hpfs_search_hotfix_map(inode->i_sb, s);
+			n_secs = 1;
+		}
+		map_bh(bh_result, inode->i_sb, s);
+		bh_result->b_size = n_secs << 9;
+		goto ret_0;
+	}
+	if (!create) goto ret_0;
+	if (iblock<<9 != hpfs_i(inode)->mmu_private) {
+		BUG();
+		r = -EIO;
+		goto ret_r;
+	}
+	if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) {
+		hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1);
+		r = -ENOSPC;
+		goto ret_r;
+	}
+	inode->i_blocks++;
+	hpfs_i(inode)->mmu_private += 512;
+	set_buffer_new(bh_result);
+	map_bh(bh_result, inode->i_sb, hpfs_search_hotfix_map(inode->i_sb, s));
+	ret_0:
+	r = 0;
+	ret_r:
+	hpfs_unlock(inode->i_sb);
+	return r;
+}
+
+static int hpfs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
+		unsigned flags, struct iomap *iomap, struct iomap *srcmap)
+{
+	struct super_block *sb = inode->i_sb;
+	unsigned int blkbits = inode->i_blkbits;
+	unsigned int n_secs;
+	secno s;
+
+	if (WARN_ON_ONCE(flags & (IOMAP_WRITE | IOMAP_ZERO)))
+		return -EINVAL;
+
+	iomap->bdev = inode->i_sb->s_bdev;
+	iomap->offset = offset;
+
+	hpfs_lock(sb);
+	s = hpfs_bmap(inode, offset >> blkbits, &n_secs);
+	if (s) {
+		n_secs = hpfs_search_hotfix_map_for_range(sb, s,
+				min_t(loff_t, n_secs, length));
+		if (unlikely(!n_secs)) {
+			s = hpfs_search_hotfix_map(sb, s);
+			n_secs = 1;
+		}
+		iomap->type = IOMAP_MAPPED;
+		iomap->flags = IOMAP_F_MERGED;
+		iomap->addr = (u64)s << blkbits;
+		iomap->length = (u64)n_secs << blkbits;
+	} else {
+		iomap->type = IOMAP_HOLE;
+		iomap->addr = IOMAP_NULL_ADDR;
+		iomap->length = 1 << blkbits;
+	}
+
+	hpfs_unlock(sb);
+	return 0;
+}
+
+static DEFINE_IOMAP_ITER_NEXT(hpfs_iomap_next, hpfs_iomap_begin);
+
+static const struct iomap_ops hpfs_iomap_ops = {
+	.iomap_next		= hpfs_iomap_next,
+};
+
+static int hpfs_read_folio(struct file *file, struct folio *folio)
+{
+	return mpage_read_folio(folio, hpfs_get_block);
+}
+
+static void hpfs_readahead(struct readahead_control *rac)
+{
+	mpage_readahead(rac, hpfs_get_block);
+}
+
+static int hpfs_writepages(struct address_space *mapping,
+			   struct writeback_control *wbc)
+{
+	return mpage_writepages(mapping, wbc, hpfs_get_block);
+}
+
+static void hpfs_write_failed(struct address_space *mapping, loff_t to)
+{
+	struct inode *inode = mapping->host;
+
+	hpfs_lock(inode->i_sb);
+
+	if (to > inode->i_size) {
+		truncate_pagecache(inode, inode->i_size);
+		hpfs_truncate(inode);
+	}
+
+	hpfs_unlock(inode->i_sb);
+}
+
+static int hpfs_write_begin(const struct kiocb *iocb,
+			    struct address_space *mapping,
+			    loff_t pos, unsigned len,
+			    struct folio **foliop, void **fsdata)
+{
+	int ret;
+
+	ret = cont_write_begin(iocb, mapping, pos, len, foliop, fsdata,
+				hpfs_get_block,
+				&hpfs_i(mapping->host)->mmu_private);
+	if (unlikely(ret))
+		hpfs_write_failed(mapping, pos + len);
+
+	return ret;
+}
+
+static int hpfs_write_end(const struct kiocb *iocb,
+			  struct address_space *mapping,
+			  loff_t pos, unsigned len, unsigned copied,
+			  struct folio *folio, void *fsdata)
+{
+	struct inode *inode = mapping->host;
+	int err;
+	err = generic_write_end(iocb, mapping, pos, len, copied, folio, fsdata);
+	if (err < len)
+		hpfs_write_failed(mapping, pos + len);
+	if (!(err < 0)) {
+		/* make sure we write it on close, if not earlier */
+		hpfs_lock(inode->i_sb);
+		hpfs_i(inode)->i_dirty = 1;
+		hpfs_unlock(inode->i_sb);
+	}
+	return err;
+}
+
+static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block)
+{
+	return generic_block_bmap(mapping, block, hpfs_get_block);
+}
+
+static int hpfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, u64 start, u64 len)
+{
+	int ret;
+
+	inode_lock(inode);
+	len = min_t(u64, len, i_size_read(inode));
+	ret = iomap_fiemap(inode, fieinfo, start, len, &hpfs_iomap_ops);
+	inode_unlock(inode);
+
+	return ret;
+}
+
+const struct address_space_operations hpfs_aops = {
+	.dirty_folio	= block_dirty_folio,
+	.invalidate_folio = block_invalidate_folio,
+	.read_folio = hpfs_read_folio,
+	.readahead = hpfs_readahead,
+	.writepages = hpfs_writepages,
+	.write_begin = hpfs_write_begin,
+	.write_end = hpfs_write_end,
+	.bmap = _hpfs_bmap,
+	.migrate_folio = buffer_migrate_folio,
+};
+
+const struct file_operations hpfs_file_ops =
+{
+	.llseek		= generic_file_llseek,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
+	.mmap_prepare	= generic_file_mmap_prepare,
+	.release	= hpfs_file_release,
+	.fsync		= hpfs_file_fsync,
+	.splice_read	= filemap_splice_read,
+	.unlocked_ioctl	= hpfs_ioctl,
+	.compat_ioctl	= compat_ptr_ioctl,
+};
+
+const struct inode_operations hpfs_file_iops =
+{
+	.setattr	= hpfs_setattr,
+	.fiemap		= hpfs_fiemap,
+};
diff --git a/fs/hpfs/hpfs.h b/fs/hpfs/hpfs.h
new file mode 100644
index 000000000..353f73c91
--- /dev/null
+++ b/fs/hpfs/hpfs.h
@@ -0,0 +1,579 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  linux/fs/hpfs/hpfs.h
+ *
+ *  HPFS structures by Chris Smith, 1993
+ *
+ *  a little bit modified by Mikulas Patocka, 1998-1999
+ */
+
+/* The paper
+
+     Duncan, Roy
+     Design goals and implementation of the new High Performance File System
+     Microsoft Systems Journal  Sept 1989  v4 n5 p1(13)
+
+   describes what HPFS looked like when it was new, and it is the source
+   of most of the information given here.  The rest is conjecture.
+
+   For definitive information on the Duncan paper, see it, not this file.
+   For definitive information on HPFS, ask somebody else -- this is guesswork.
+   There are certain to be many mistakes. */
+
+#if !defined(__LITTLE_ENDIAN) && !defined(__BIG_ENDIAN)
+#error unknown endian
+#endif
+
+/* Notation */
+
+typedef u32 secno;			/* sector number, partition relative */
+
+typedef secno dnode_secno;		/* sector number of a dnode */
+typedef secno fnode_secno;		/* sector number of an fnode */
+typedef secno anode_secno;		/* sector number of an anode */
+
+typedef u32 time32_t;		/* 32-bit time_t type */
+
+/* sector 0 */
+
+/* The boot block is very like a FAT boot block, except that the
+   29h signature byte is 28h instead, and the ID string is "HPFS". */
+
+#define BB_MAGIC 0xaa55
+
+struct hpfs_boot_block
+{
+  u8 jmp[3];
+  u8 oem_id[8];
+  u8 bytes_per_sector[2];	/* 512 */
+  u8 sectors_per_cluster;
+  u8 n_reserved_sectors[2];
+  u8 n_fats;
+  u8 n_rootdir_entries[2];
+  u8 n_sectors_s[2];
+  u8 media_byte;
+  __le16 sectors_per_fat;
+  __le16 sectors_per_track;
+  __le16 heads_per_cyl;
+  __le32 n_hidden_sectors;
+  __le32 n_sectors_l;		/* size of partition */
+  u8 drive_number;
+  u8 mbz;
+  u8 sig_28h;			/* 28h */
+  u8 vol_serno[4];
+  u8 vol_label[11];
+  u8 sig_hpfs[8];		/* "HPFS    " */
+  u8 pad[448];
+  __le16 magic;			/* aa55 */
+};
+
+
+/* sector 16 */
+
+/* The super block has the pointer to the root directory. */
+
+#define SB_MAGIC 0xf995e849
+
+struct hpfs_super_block
+{
+  __le32 magic;				/* f995 e849 */
+  __le32 magic1;			/* fa53 e9c5, more magic? */
+  u8 version;				/* version of a filesystem  usually 2 */
+  u8 funcversion;			/* functional version - oldest version
+  					   of filesystem that can understand
+					   this disk */
+  __le16 zero;				/* 0 */
+  __le32 root;				/* fnode of root directory */
+  __le32 n_sectors;			/* size of filesystem */
+  __le32 n_badblocks;			/* number of bad blocks */
+  __le32 bitmaps;			/* pointers to free space bit maps */
+  __le32 zero1;				/* 0 */
+  __le32 badblocks;			/* bad block list */
+  __le32 zero3;				/* 0 */
+  __le32 last_chkdsk;			/* date last checked, 0 if never */
+  __le32 last_optimize;			/* date last optimized, 0 if never */
+  __le32 n_dir_band;			/* number of sectors in dir band */
+  __le32 dir_band_start;			/* first sector in dir band */
+  __le32 dir_band_end;			/* last sector in dir band */
+  __le32 dir_band_bitmap;		/* free space map, 1 dnode per bit */
+  u8 volume_name[32];			/* not used */
+  __le32 user_id_table;			/* 8 preallocated sectors - user id */
+  u32 zero6[103];			/* 0 */
+};
+
+
+/* sector 17 */
+
+/* The spare block has pointers to spare sectors.  */
+
+#define SP_MAGIC 0xf9911849
+
+struct hpfs_spare_block
+{
+  __le32 magic;				/* f991 1849 */
+  __le32 magic1;				/* fa52 29c5, more magic? */
+
+#ifdef __LITTLE_ENDIAN
+  u8 dirty: 1;				/* 0 clean, 1 "improperly stopped" */
+  u8 sparedir_used: 1;			/* spare dirblks used */
+  u8 hotfixes_used: 1;			/* hotfixes used */
+  u8 bad_sector: 1;			/* bad sector, corrupted disk (???) */
+  u8 bad_bitmap: 1;			/* bad bitmap */
+  u8 fast: 1;				/* partition was fast formatted */
+  u8 old_wrote: 1;			/* old version wrote to partition */
+  u8 old_wrote_1: 1;			/* old version wrote to partition (?) */
+#else
+  u8 old_wrote_1: 1;			/* old version wrote to partition (?) */
+  u8 old_wrote: 1;			/* old version wrote to partition */
+  u8 fast: 1;				/* partition was fast formatted */
+  u8 bad_bitmap: 1;			/* bad bitmap */
+  u8 bad_sector: 1;			/* bad sector, corrupted disk (???) */
+  u8 hotfixes_used: 1;			/* hotfixes used */
+  u8 sparedir_used: 1;			/* spare dirblks used */
+  u8 dirty: 1;				/* 0 clean, 1 "improperly stopped" */
+#endif
+
+#ifdef __LITTLE_ENDIAN
+  u8 install_dasd_limits: 1;		/* HPFS386 flags */
+  u8 resynch_dasd_limits: 1;
+  u8 dasd_limits_operational: 1;
+  u8 multimedia_active: 1;
+  u8 dce_acls_active: 1;
+  u8 dasd_limits_dirty: 1;
+  u8 flag67: 2;
+#else
+  u8 flag67: 2;
+  u8 dasd_limits_dirty: 1;
+  u8 dce_acls_active: 1;
+  u8 multimedia_active: 1;
+  u8 dasd_limits_operational: 1;
+  u8 resynch_dasd_limits: 1;
+  u8 install_dasd_limits: 1;		/* HPFS386 flags */
+#endif
+
+  u8 mm_contlgulty;
+  u8 unused;
+
+  __le32 hotfix_map;			/* info about remapped bad sectors */
+  __le32 n_spares_used;			/* number of hotfixes */
+  __le32 n_spares;			/* number of spares in hotfix map */
+  __le32 n_dnode_spares_free;		/* spare dnodes unused */
+  __le32 n_dnode_spares;		/* length of spare_dnodes[] list,
+					   follows in this block*/
+  __le32 code_page_dir;			/* code page directory block */
+  __le32 n_code_pages;			/* number of code pages */
+  __le32 super_crc;			/* on HPFS386 and LAN Server this is
+  					   checksum of superblock, on normal
+					   OS/2 unused */
+  __le32 spare_crc;			/* on HPFS386 checksum of spareblock */
+  __le32 zero1[15];			/* unused */
+  __le32 spare_dnodes[100];		/* emergency free dnode list */
+  __le32 zero2[1];			/* room for more? */
+};
+
+/* The bad block list is 4 sectors long.  The first word must be zero,
+   the remaining words give n_badblocks bad block numbers.
+   I bet you can see it coming... */
+
+#define BAD_MAGIC 0
+       
+/* The hotfix map is 4 sectors long.  It looks like
+
+       secno from[n_spares];
+       secno to[n_spares];
+
+   The to[] list is initialized to point to n_spares preallocated empty
+   sectors.  The from[] list contains the sector numbers of bad blocks
+   which have been remapped to corresponding sectors in the to[] list.
+   n_spares_used gives the length of the from[] list. */
+
+
+/* Sectors 18 and 19 are preallocated and unused.
+   Maybe they're spares for 16 and 17, but simple substitution fails. */
+
+
+/* The code page info pointed to by the spare block consists of an index
+   block and blocks containing uppercasing tables.  I don't know what
+   these are for (CHKDSK, maybe?) -- OS/2 does not seem to use them
+   itself.  Linux doesn't use them either. */
+
+/* block pointed to by spareblock->code_page_dir */
+
+#define CP_DIR_MAGIC 0x494521f7
+
+struct code_page_directory
+{
+  __le32 magic;				/* 4945 21f7 */
+  __le32 n_code_pages;			/* number of pointers following */
+  __le32 zero1[2];
+  struct {
+    __le16 ix;				/* index */
+    __le16 code_page_number;		/* code page number */
+    __le32 bounds;			/* matches corresponding word
+					   in data block */
+    __le32 code_page_data;		/* sector number of a code_page_data
+					   containing c.p. array */
+    __le16 index;			/* index in c.p. array in that sector*/
+    __le16 unknown;			/* some unknown value; usually 0;
+    					   2 in Japanese version */
+  } array[31];				/* unknown length */
+};
+
+/* blocks pointed to by code_page_directory */
+
+#define CP_DATA_MAGIC 0x894521f7
+
+struct code_page_data
+{
+  __le32 magic;				/* 8945 21f7 */
+  __le32 n_used;			/* # elements used in c_p_data[] */
+  __le32 bounds[3];			/* looks a bit like
+					     (beg1,end1), (beg2,end2)
+					   one byte each */
+  __le16 offs[3];			/* offsets from start of sector
+					   to start of c_p_data[ix] */
+  struct {
+    __le16 ix;				/* index */
+    __le16 code_page_number;		/* code page number */
+    __le16 unknown;			/* the same as in cp directory */
+    u8 map[128];			/* upcase table for chars 80..ff */
+    __le16 zero2;
+  } code_page[3];
+  u8 incognita[78];
+};
+
+
+/* Free space bitmaps are 4 sectors long, which is 16384 bits.
+   16384 sectors is 8 meg, and each 8 meg band has a 4-sector bitmap.
+   Bit order in the maps is little-endian.  0 means taken, 1 means free.
+
+   Bit map sectors are marked allocated in the bit maps, and so are sectors 
+   off the end of the partition.
+
+   Band 0 is sectors 0-3fff, its map is in sectors 18-1b.
+   Band 1 is 4000-7fff, its map is in 7ffc-7fff.
+   Band 2 is 8000-ffff, its map is in 8000-8003.
+   The remaining bands have maps in their first (even) or last (odd) 4 sectors
+     -- if the last, partial, band is odd its map is in its last 4 sectors.
+
+   The bitmap locations are given in a table pointed to by the super block.
+   No doubt they aren't constrained to be at 18, 7ffc, 8000, ...; that is
+   just where they usually are.
+
+   The "directory band" is a bunch of sectors preallocated for dnodes.
+   It has a 4-sector free space bitmap of its own.  Each bit in the map
+   corresponds to one 4-sector dnode, bit 0 of the map corresponding to
+   the first 4 sectors of the directory band.  The entire band is marked
+   allocated in the main bitmap.   The super block gives the locations
+   of the directory band and its bitmap.  ("band" doesn't mean it is
+   8 meg long; it isn't.)  */
+
+
+/* dnode: directory.  4 sectors long */
+
+/* A directory is a tree of dnodes.  The fnode for a directory
+   contains one pointer, to the root dnode of the tree.  The fnode
+   never moves, the dnodes do the B-tree thing, splitting and merging
+   as files are added and removed.  */
+
+#define DNODE_MAGIC   0x77e40aae
+
+struct dnode {
+  __le32 magic;				/* 77e4 0aae */
+  __le32 first_free;			/* offset from start of dnode to
+					   first free dir entry */
+#ifdef __LITTLE_ENDIAN
+  u8 root_dnode: 1;			/* Is it root dnode? */
+  u8 increment_me: 7;			/* some kind of activity counter? */
+					/* Neither HPFS.IFS nor CHKDSK cares
+					   if you change this word */
+#else
+  u8 increment_me: 7;			/* some kind of activity counter? */
+					/* Neither HPFS.IFS nor CHKDSK cares
+					   if you change this word */
+  u8 root_dnode: 1;			/* Is it root dnode? */
+#endif
+  u8 increment_me2[3];
+  __le32 up;				/* (root dnode) directory's fnode
+					   (nonroot) parent dnode */
+  __le32 self;			/* pointer to this dnode */
+  u8 dirent[2028];			/* one or more dirents */
+};
+
+struct hpfs_dirent {
+  __le16 length;			/* offset to next dirent */
+
+#ifdef __LITTLE_ENDIAN
+  u8 first: 1;				/* set on phony ^A^A (".") entry */
+  u8 has_acl: 1;
+  u8 down: 1;				/* down pointer present (after name) */
+  u8 last: 1;				/* set on phony \377 entry */
+  u8 has_ea: 1;				/* entry has EA */
+  u8 has_xtd_perm: 1;			/* has extended perm list (???) */
+  u8 has_explicit_acl: 1;
+  u8 has_needea: 1;			/* ?? some EA has NEEDEA set
+					   I have no idea why this is
+					   interesting in a dir entry */
+#else
+  u8 has_needea: 1;			/* ?? some EA has NEEDEA set
+					   I have no idea why this is
+					   interesting in a dir entry */
+  u8 has_explicit_acl: 1;
+  u8 has_xtd_perm: 1;			/* has extended perm list (???) */
+  u8 has_ea: 1;				/* entry has EA */
+  u8 last: 1;				/* set on phony \377 entry */
+  u8 down: 1;				/* down pointer present (after name) */
+  u8 has_acl: 1;
+  u8 first: 1;				/* set on phony ^A^A (".") entry */
+#endif
+
+#ifdef __LITTLE_ENDIAN
+  u8 read_only: 1;			/* dos attrib */
+  u8 hidden: 1;				/* dos attrib */
+  u8 system: 1;				/* dos attrib */
+  u8 flag11: 1;				/* would be volume label dos attrib */
+  u8 directory: 1;			/* dos attrib */
+  u8 archive: 1;			/* dos attrib */
+  u8 not_8x3: 1;			/* name is not 8.3 */
+  u8 flag15: 1;
+#else
+  u8 flag15: 1;
+  u8 not_8x3: 1;			/* name is not 8.3 */
+  u8 archive: 1;			/* dos attrib */
+  u8 directory: 1;			/* dos attrib */
+  u8 flag11: 1;				/* would be volume label dos attrib */
+  u8 system: 1;				/* dos attrib */
+  u8 hidden: 1;				/* dos attrib */
+  u8 read_only: 1;			/* dos attrib */
+#endif
+
+  __le32 fnode;				/* fnode giving allocation info */
+  __le32 write_date;			/* mtime */
+  __le32 file_size;			/* file length, bytes */
+  __le32 read_date;			/* atime */
+  __le32 creation_date;			/* ctime */
+  __le32 ea_size;			/* total EA length, bytes */
+  u8 no_of_acls;			/* number of ACL's (low 3 bits) */
+  u8 ix;				/* code page index (of filename), see
+					   struct code_page_data */
+  u8 namelen;				/* file name length */
+  u8 name[];				/* file name */
+  /* dnode_secno down;	  btree down pointer, if present,
+     			  follows name on next word boundary, or maybe it
+			  precedes next dirent, which is on a word boundary. */
+};
+
+
+/* B+ tree: allocation info in fnodes and anodes */
+
+/* dnodes point to fnodes which are responsible for listing the sectors
+   assigned to the file.  This is done with trees of (length,address)
+   pairs.  (Actually triples, of (length, file-address, disk-address)
+   which can represent holes.  Find out if HPFS does that.)
+   At any rate, fnodes contain a small tree; if subtrees are needed
+   they occupy essentially a full block in anodes.  A leaf-level tree node
+   has 3-word entries giving sector runs, a non-leaf node has 2-word
+   entries giving subtree pointers.  A flag in the header says which. */
+
+struct bplus_leaf_node
+{
+  __le32 file_secno;			/* first file sector in extent */
+  __le32 length;			/* length, sectors */
+  __le32 disk_secno;			/* first corresponding disk sector */
+};
+
+struct bplus_internal_node
+{
+  __le32 file_secno;			/* subtree maps sectors < this  */
+  __le32 down;				/* pointer to subtree */
+};
+
+enum {
+	BP_hbff = 1,
+	BP_fnode_parent = 0x20,
+	BP_binary_search = 0x40,
+	BP_internal = 0x80
+};
+
+/**
+ * GET_BTREE_PTR() - Get a pointer to struct bplus_header
+ *
+ * Wrapper around container_of() to retrieve a pointer to struct
+ * bplus_header from a pointer to struct bplus_header_fixed.
+ *
+ * @ptr: Pointer to struct bplus_header_fixed.
+ *
+ */
+#define GET_BTREE_PTR(ptr) \
+	container_of(ptr, struct bplus_header, __hdr)
+
+struct bplus_header
+{
+	/* New members MUST be added within the struct_group() macro below. */
+	struct_group_tagged(bplus_header_fixed, __hdr,
+		u8 flags;		/* bit 0 - high bit of first free entry offset
+					   bit 5 - we're pointed to by an fnode,
+					   the data btree or some ea or the
+					   main ea bootage pointer ea_secno
+					   bit 6 - suggest binary search (unused)
+					   bit 7 - 1 -> (internal) tree of anodes
+						   0 -> (leaf) list of extents */
+		u8 fill[3];
+		u8 n_free_nodes;	/* free nodes in following array */
+		u8 n_used_nodes;	/* used nodes in following array */
+		__le16 first_free;	/* offset from start of header to
+					   first free node in array */
+	);
+	union {
+		/* (internal) 2-word entries giving subtree pointers */
+		DECLARE_FLEX_ARRAY(struct bplus_internal_node, internal);
+		/* (external) 3-word entries giving sector runs */
+		DECLARE_FLEX_ARRAY(struct bplus_leaf_node, external);
+	} u;
+};
+static_assert(offsetof(struct bplus_header, u.internal) == sizeof(struct bplus_header_fixed),
+	      "struct member likely outside of struct_group_tagged()");
+
+static inline bool bp_internal(struct bplus_header *bp)
+{
+	return bp->flags & BP_internal;
+}
+
+static inline bool bp_fnode_parent(struct bplus_header *bp)
+{
+	return bp->flags & BP_fnode_parent;
+}
+
+/* fnode: root of allocation b+ tree, and EA's */
+
+/* Every file and every directory has one fnode, pointed to by the directory
+   entry and pointing to the file's sectors or directory's root dnode.  EA's
+   are also stored here, and there are said to be ACL's somewhere here too. */
+
+#define FNODE_MAGIC 0xf7e40aae
+
+enum {FNODE_anode = cpu_to_le16(2), FNODE_dir = cpu_to_le16(256)};
+struct fnode
+{
+  __le32 magic;				/* f7e4 0aae */
+  __le32 zero1[2];			/* read history */
+  u8 len, name[15];			/* true length, truncated name */
+  __le32 up;				/* pointer to file's directory fnode */
+  __le32 acl_size_l;
+  __le32 acl_secno;
+  __le16 acl_size_s;
+  u8 acl_anode;
+  u8 zero2;				/* history bit count */
+  __le32 ea_size_l;			/* length of disk-resident ea's */
+  __le32 ea_secno;			/* first sector of disk-resident ea's*/
+  __le16 ea_size_s;			/* length of fnode-resident ea's */
+
+  __le16 flags;				/* bit 1 set -> ea_secno is an anode */
+					/* bit 8 set -> directory.  first & only extent
+					   points to dnode. */
+  struct bplus_header_fixed btree;	/* b+ tree, 8 extents or 12 subtrees */
+  union {
+    struct bplus_leaf_node external[8];
+    struct bplus_internal_node internal[12];
+  } u;
+
+  __le32 file_size;			/* file length, bytes */
+  __le32 n_needea;			/* number of EA's with NEEDEA set */
+  u8 user_id[16];			/* unused */
+  __le16 ea_offs;			/* offset from start of fnode
+					   to first fnode-resident ea */
+  u8 dasd_limit_treshhold;
+  u8 dasd_limit_delta;
+  __le32 dasd_limit;
+  __le32 dasd_usage;
+  u8 ea[316];				/* zero or more EA's, packed together
+					   with no alignment padding.
+					   (Do not use this name, get here
+					   via fnode + ea_offs. I think.) */
+};
+
+static inline bool fnode_in_anode(struct fnode *p)
+{
+	return (p->flags & FNODE_anode) != 0;
+}
+
+static inline bool fnode_is_dir(struct fnode *p)
+{
+	return (p->flags & FNODE_dir) != 0;
+}
+
+
+/* anode: 99.44% pure allocation tree */
+
+#define ANODE_MAGIC 0x37e40aae
+
+struct anode
+{
+  __le32 magic;				/* 37e4 0aae */
+  __le32 self;				/* pointer to this anode */
+  __le32 up;				/* parent anode or fnode */
+
+  struct bplus_header_fixed btree;	/* b+tree, 40 extents or 60 subtrees */
+  union {
+    struct bplus_leaf_node external[40];
+    struct bplus_internal_node internal[60];
+  } u;
+
+  __le32 fill[3];			/* unused */
+};
+
+
+/* extended attributes.
+
+   A file's EA info is stored as a list of (name,value) pairs.  It is
+   usually in the fnode, but (if it's large) it is moved to a single
+   sector run outside the fnode, or to multiple runs with an anode tree
+   that points to them.
+
+   The value of a single EA is stored along with the name, or (if large)
+   it is moved to a single sector run, or multiple runs pointed to by an
+   anode tree, pointed to by the value field of the (name,value) pair.
+
+   Flags in the EA tell whether the value is immediate, in a single sector
+   run, or in multiple runs.  Flags in the fnode tell whether the EA list
+   is immediate, in a single run, or in multiple runs. */
+
+enum {EA_indirect = 1, EA_anode = 2, EA_needea = 128 };
+struct extended_attribute
+{
+  u8 flags;				/* bit 0 set -> value gives sector number
+					   where real value starts */
+					/* bit 1 set -> sector is an anode
+					   that points to fragmented value */
+					/* bit 7 set -> required ea */
+  u8 namelen;				/* length of name, bytes */
+  u8 valuelen_lo;			/* length of value, bytes */
+  u8 valuelen_hi;			/* length of value, bytes */
+  u8 name[];
+  /*
+    u8 name[namelen];			ascii attrib name
+    u8 nul;				terminating '\0', not counted
+    u8 value[valuelen];			value, arbitrary
+      if this.flags & 1, valuelen is 8 and the value is
+        u32 length;			real length of value, bytes
+        secno secno;			sector address where it starts
+      if this.anode, the above sector number is the root of an anode tree
+        which points to the value.
+  */
+};
+
+static inline bool ea_indirect(struct extended_attribute *ea)
+{
+	return ea->flags & EA_indirect;
+}
+
+static inline bool ea_in_anode(struct extended_attribute *ea)
+{
+	return ea->flags & EA_anode;
+}
+
+/*
+   Local Variables:
+   comment-column: 40
+   End:
+*/
diff --git a/fs/hpfs/hpfs_fn.h b/fs/hpfs/hpfs_fn.h
new file mode 100644
index 000000000..237c1c23e
--- /dev/null
+++ b/fs/hpfs/hpfs_fn.h
@@ -0,0 +1,379 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  linux/fs/hpfs/hpfs_fn.h
+ *
+ *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
+ *
+ *  function headers
+ */
+
+//#define DBG
+//#define DEBUG_LOCKS
+#ifdef pr_fmt
+#undef pr_fmt
+#endif
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/mutex.h>
+#include <linux/pagemap.h>
+#include <linux/buffer_head.h>
+#include <linux/slab.h>
+#include <linux/sched/signal.h>
+#include <linux/blkdev.h>
+#include <linux/unaligned.h>
+
+#include "hpfs.h"
+
+#define EIOERROR  EIO
+#define EFSERROR  EUCLEAN
+
+#define ANODE_ALLOC_FWD	512
+#define FNODE_ALLOC_FWD	0
+#define ALLOC_FWD_MIN	16
+#define ALLOC_FWD_MAX	128
+#define ALLOC_M		1
+#define FNODE_RD_AHEAD	16
+#define ANODE_RD_AHEAD	0
+#define DNODE_RD_AHEAD	72
+#define COUNT_RD_AHEAD	62
+
+#define FREE_DNODES_ADD	58
+#define FREE_DNODES_DEL	29
+
+#define CHKCOND(x,y) if (!(x)) printk y
+
+struct hpfs_inode_info {
+	loff_t mmu_private;
+	ino_t i_parent_dir;	/* (directories) gives fnode of parent dir */
+	unsigned i_dno;		/* (directories) root dnode */
+	unsigned i_dpos;	/* (directories) temp for readdir */
+	unsigned i_dsubdno;	/* (directories) temp for readdir */
+	unsigned i_file_sec;	/* (files) minimalist cache of alloc info */
+	unsigned i_disk_sec;	/* (files) minimalist cache of alloc info */
+	unsigned i_n_secs;	/* (files) minimalist cache of alloc info */
+	unsigned i_ea_size;	/* size of extended attributes */
+	unsigned i_ea_mode : 1;	/* file's permission is stored in ea */
+	unsigned i_ea_uid : 1;	/* file's uid is stored in ea */
+	unsigned i_ea_gid : 1;	/* file's gid is stored in ea */
+	unsigned i_dirty : 1;
+	loff_t **i_rddir_off;
+	struct inode vfs_inode;
+};
+
+struct hpfs_sb_info {
+	struct mutex hpfs_mutex;	/* global hpfs lock */
+	ino_t sb_root;			/* inode number of root dir */
+	unsigned sb_fs_size;		/* file system size, sectors */
+	unsigned sb_bitmaps;		/* sector number of bitmap list */
+	unsigned sb_dirband_start;	/* directory band start sector */
+	unsigned sb_dirband_size;	/* directory band size, dnodes */
+	unsigned sb_dmap;		/* sector number of dnode bit map */
+	unsigned sb_n_free;		/* free blocks for statfs, or -1 */
+	unsigned sb_n_free_dnodes;	/* free dnodes for statfs, or -1 */
+	kuid_t sb_uid;			/* uid from mount options */
+	kgid_t sb_gid;			/* gid from mount options */
+	umode_t sb_mode;		/* mode from mount options */
+	unsigned sb_eas : 2;		/* eas: 0-ignore, 1-ro, 2-rw */
+	unsigned sb_err : 2;		/* on errs: 0-cont, 1-ro, 2-panic */
+	unsigned sb_chk : 2;		/* checks: 0-no, 1-normal, 2-strict */
+	unsigned sb_lowercase : 1;	/* downcase filenames hackery */
+	unsigned sb_was_error : 1;	/* there was an error, set dirty flag */
+	unsigned sb_chkdsk : 2;		/* chkdsk: 0-no, 1-on errs, 2-allways */
+	unsigned char *sb_cp_table;	/* code page tables: */
+					/* 	128 bytes uppercasing table & */
+					/*	128 bytes lowercasing table */
+	__le32 *sb_bmp_dir;		/* main bitmap directory */
+	unsigned sb_c_bitmap;		/* current bitmap */
+	unsigned sb_max_fwd_alloc;	/* max forwad allocation */
+	int sb_timeshift;
+	struct rcu_head rcu;
+
+	unsigned n_hotfixes;
+	secno hotfix_from[256];
+	secno hotfix_to[256];
+};
+
+/* Four 512-byte buffers and the 2k block obtained by concatenating them */
+
+struct quad_buffer_head {
+	struct buffer_head *bh[4];
+	void *data;
+};
+
+/* The b-tree down pointer from a dir entry */
+
+static inline dnode_secno de_down_pointer (struct hpfs_dirent *de)
+{
+  CHKCOND(de->down,("HPFS: de_down_pointer: !de->down\n"));
+  return le32_to_cpu(*(__le32 *) ((void *) de + le16_to_cpu(de->length) - 4));
+}
+
+/* The first dir entry in a dnode */
+
+static inline struct hpfs_dirent *dnode_first_de (struct dnode *dnode)
+{
+  return (void *) dnode->dirent;
+}
+
+/* The end+1 of the dir entries */
+
+static inline struct hpfs_dirent *dnode_end_de (struct dnode *dnode)
+{
+  CHKCOND(le32_to_cpu(dnode->first_free)>=0x14 && le32_to_cpu(dnode->first_free)<=0xa00,("HPFS: dnode_end_de: dnode->first_free = %x\n",(unsigned)le32_to_cpu(dnode->first_free)));
+  return (void *) dnode + le32_to_cpu(dnode->first_free);
+}
+
+/* The dir entry after dir entry de */
+
+static inline struct hpfs_dirent *de_next_de (struct hpfs_dirent *de)
+{
+  CHKCOND(le16_to_cpu(de->length)>=0x20 && le16_to_cpu(de->length)<0x800,("HPFS: de_next_de: de->length = %x\n",(unsigned)le16_to_cpu(de->length)));
+  return (void *) de + le16_to_cpu(de->length);
+}
+
+static inline struct extended_attribute *fnode_ea(struct fnode *fnode)
+{
+	return (struct extended_attribute *)((char *)fnode + le16_to_cpu(fnode->ea_offs) + le16_to_cpu(fnode->acl_size_s));
+}
+
+static inline struct extended_attribute *fnode_end_ea(struct fnode *fnode)
+{
+	return (struct extended_attribute *)((char *)fnode + le16_to_cpu(fnode->ea_offs) + le16_to_cpu(fnode->acl_size_s) + le16_to_cpu(fnode->ea_size_s));
+}
+
+static unsigned ea_valuelen(struct extended_attribute *ea)
+{
+	return ea->valuelen_lo + 256 * ea->valuelen_hi;
+}
+
+static inline struct extended_attribute *next_ea(struct extended_attribute *ea)
+{
+	return (struct extended_attribute *)((char *)ea + 5 + ea->namelen + ea_valuelen(ea));
+}
+
+static inline secno ea_sec(struct extended_attribute *ea)
+{
+	return le32_to_cpu(get_unaligned((__le32 *)((char *)ea + 9 + ea->namelen)));
+}
+
+static inline secno ea_len(struct extended_attribute *ea)
+{
+	return le32_to_cpu(get_unaligned((__le32 *)((char *)ea + 5 + ea->namelen)));
+}
+
+static inline char *ea_data(struct extended_attribute *ea)
+{
+	return (char *)((char *)ea + 5 + ea->namelen);
+}
+
+static inline unsigned de_size(int namelen, secno down_ptr)
+{
+	return ((0x1f + namelen + 3) & ~3) + (down_ptr ? 4 : 0);
+}
+
+static inline void copy_de(struct hpfs_dirent *dst, struct hpfs_dirent *src)
+{
+	int a;
+	int n;
+	if (!dst || !src) return;
+	a = dst->down;
+	n = dst->not_8x3;
+	memcpy((char *)dst + 2, (char *)src + 2, 28);
+	dst->down = a;
+	dst->not_8x3 = n;
+}
+
+static inline unsigned tstbits(__le32 *bmp, unsigned b, unsigned n)
+{
+	int i;
+	if ((b >= 0x4000) || (b + n - 1 >= 0x4000)) return n;
+	if (!((le32_to_cpu(bmp[(b & 0x3fff) >> 5]) >> (b & 0x1f)) & 1)) return 1;
+	for (i = 1; i < n; i++)
+		if (!((le32_to_cpu(bmp[((b+i) & 0x3fff) >> 5]) >> ((b+i) & 0x1f)) & 1))
+			return i + 1;
+	return 0;
+}
+
+/* alloc.c */
+
+int hpfs_chk_sectors(struct super_block *, secno, int, char *);
+secno hpfs_alloc_sector(struct super_block *, secno, unsigned, int);
+int hpfs_alloc_if_possible(struct super_block *, secno);
+void hpfs_free_sectors(struct super_block *, secno, unsigned);
+int hpfs_check_free_dnodes(struct super_block *, int);
+void hpfs_free_dnode(struct super_block *, secno);
+struct dnode *hpfs_alloc_dnode(struct super_block *, secno, dnode_secno *, struct quad_buffer_head *);
+struct fnode *hpfs_alloc_fnode(struct super_block *, secno, fnode_secno *, struct buffer_head **);
+struct anode *hpfs_alloc_anode(struct super_block *, secno, anode_secno *, struct buffer_head **);
+int hpfs_trim_fs(struct super_block *, u64, u64, u64, unsigned *);
+
+/* anode.c */
+
+secno hpfs_bplus_lookup(struct super_block *, struct inode *, struct bplus_header *, unsigned, struct buffer_head *);
+secno hpfs_add_sector_to_btree(struct super_block *, secno, int, unsigned);
+void hpfs_remove_btree(struct super_block *, struct bplus_header *);
+int hpfs_ea_read(struct super_block *, secno, int, unsigned, unsigned, char *);
+int hpfs_ea_write(struct super_block *, secno, int, unsigned, unsigned, const char *);
+void hpfs_ea_remove(struct super_block *, secno, int, unsigned);
+void hpfs_truncate_btree(struct super_block *, secno, int, unsigned);
+void hpfs_remove_fnode(struct super_block *, fnode_secno fno);
+
+/* buffer.c */
+
+secno hpfs_search_hotfix_map(struct super_block *s, secno sec);
+unsigned hpfs_search_hotfix_map_for_range(struct super_block *s, secno sec, unsigned n);
+void hpfs_prefetch_sectors(struct super_block *, unsigned, int);
+void *hpfs_map_sector(struct super_block *, unsigned, struct buffer_head **, int);
+void *hpfs_get_sector(struct super_block *, unsigned, struct buffer_head **);
+void *hpfs_map_4sectors(struct super_block *, unsigned, struct quad_buffer_head *, int);
+void *hpfs_get_4sectors(struct super_block *, unsigned, struct quad_buffer_head *);
+void hpfs_brelse4(struct quad_buffer_head *);
+void hpfs_mark_4buffers_dirty(struct quad_buffer_head *);
+
+/* dentry.c */
+
+extern const struct dentry_operations hpfs_dentry_operations;
+
+/* dir.c */
+
+struct dentry *hpfs_lookup(struct inode *, struct dentry *, unsigned int);
+extern const struct file_operations hpfs_dir_ops;
+
+/* dnode.c */
+
+int hpfs_add_pos(struct inode *, loff_t *);
+void hpfs_del_pos(struct inode *, loff_t *);
+struct hpfs_dirent *hpfs_add_de(struct super_block *, struct dnode *,
+				const unsigned char *, unsigned, secno);
+int hpfs_add_dirent(struct inode *, const unsigned char *, unsigned,
+		    struct hpfs_dirent *);
+int hpfs_remove_dirent(struct inode *, dnode_secno, struct hpfs_dirent *, struct quad_buffer_head *, int);
+void hpfs_count_dnodes(struct super_block *, dnode_secno, int *, int *, int *);
+dnode_secno hpfs_de_as_down_as_possible(struct super_block *, dnode_secno dno);
+struct hpfs_dirent *map_pos_dirent(struct inode *, loff_t *, struct quad_buffer_head *);
+struct hpfs_dirent *map_dirent(struct inode *, dnode_secno,
+			       const unsigned char *, unsigned, dnode_secno *,
+			       struct quad_buffer_head *);
+void hpfs_remove_dtree(struct super_block *, dnode_secno);
+struct hpfs_dirent *map_fnode_dirent(struct super_block *, fnode_secno, struct fnode *, struct quad_buffer_head *);
+
+/* ea.c */
+
+void hpfs_ea_ext_remove(struct super_block *, secno, int, unsigned);
+int hpfs_read_ea(struct super_block *, struct fnode *, char *, char *, int);
+char *hpfs_get_ea(struct super_block *, struct fnode *, char *, int *);
+void hpfs_set_ea(struct inode *, struct fnode *, const char *,
+		 const char *, int);
+
+/* file.c */
+
+int hpfs_file_fsync(struct file *, loff_t, loff_t, int);
+void hpfs_truncate(struct inode *);
+extern const struct file_operations hpfs_file_ops;
+extern const struct inode_operations hpfs_file_iops;
+extern const struct address_space_operations hpfs_aops;
+
+/* inode.c */
+
+void hpfs_init_inode(struct inode *);
+void hpfs_read_inode(struct inode *);
+void hpfs_write_inode(struct inode *);
+void hpfs_write_inode_nolock(struct inode *);
+int hpfs_setattr(struct mnt_idmap *, struct dentry *, struct iattr *);
+void hpfs_write_if_changed(struct inode *);
+void hpfs_evict_inode(struct inode *);
+
+/* map.c */
+
+__le32 *hpfs_map_dnode_bitmap(struct super_block *, struct quad_buffer_head *);
+__le32 *hpfs_map_bitmap(struct super_block *, unsigned, struct quad_buffer_head *, char *);
+void hpfs_prefetch_bitmap(struct super_block *, unsigned);
+unsigned char *hpfs_load_code_page(struct super_block *, secno);
+__le32 *hpfs_load_bitmap_directory(struct super_block *, secno bmp);
+void hpfs_load_hotfix_map(struct super_block *s, struct hpfs_spare_block *spareblock);
+struct fnode *hpfs_map_fnode(struct super_block *s, ino_t, struct buffer_head **);
+struct anode *hpfs_map_anode(struct super_block *s, anode_secno, struct buffer_head **);
+struct dnode *hpfs_map_dnode(struct super_block *s, dnode_secno, struct quad_buffer_head *);
+dnode_secno hpfs_fnode_dno(struct super_block *s, ino_t ino);
+
+/* name.c */
+
+unsigned char hpfs_upcase(unsigned char *, unsigned char);
+int hpfs_chk_name(const unsigned char *, unsigned *);
+unsigned char *hpfs_translate_name(struct super_block *, unsigned char *, unsigned, int, int);
+int hpfs_compare_names(struct super_block *, const unsigned char *, unsigned,
+		       const unsigned char *, unsigned, int);
+int hpfs_is_name_long(const unsigned char *, unsigned);
+void hpfs_adjust_length(const unsigned char *, unsigned *);
+
+/* namei.c */
+
+extern const struct inode_operations hpfs_dir_iops;
+extern const struct address_space_operations hpfs_symlink_aops;
+
+static inline struct hpfs_inode_info *hpfs_i(struct inode *inode)
+{
+	return container_of(inode, struct hpfs_inode_info, vfs_inode);
+}
+
+static inline struct hpfs_sb_info *hpfs_sb(struct super_block *sb)
+{
+	return sb->s_fs_info;
+}
+
+/* super.c */
+
+__printf(2, 3)
+void hpfs_error(struct super_block *, const char *, ...);
+int hpfs_stop_cycles(struct super_block *, int, int *, int *, char *);
+unsigned hpfs_get_free_dnodes(struct super_block *);
+long hpfs_ioctl(struct file *file, unsigned cmd, unsigned long arg);
+
+/*
+ * local time (HPFS) to GMT (Unix)
+ */
+
+static inline time64_t local_to_gmt(struct super_block *s, time64_t t)
+{
+	extern struct timezone sys_tz;
+	return t + sys_tz.tz_minuteswest * 60 + hpfs_sb(s)->sb_timeshift;
+}
+
+static inline time32_t gmt_to_local(struct super_block *s, time64_t t)
+{
+	extern struct timezone sys_tz;
+	return t - sys_tz.tz_minuteswest * 60 - hpfs_sb(s)->sb_timeshift;
+}
+
+static inline time32_t local_get_seconds(struct super_block *s)
+{
+	return gmt_to_local(s, ktime_get_real_seconds());
+}
+
+/*
+ * Locking:
+ *
+ * hpfs_lock() locks the whole filesystem. It must be taken
+ * on any method called by the VFS.
+ *
+ * We don't do any per-file locking anymore, it is hard to
+ * review and HPFS is not performance-sensitive anyway.
+ */
+static inline void hpfs_lock(struct super_block *s)
+{
+	struct hpfs_sb_info *sbi = hpfs_sb(s);
+	mutex_lock(&sbi->hpfs_mutex);
+}
+
+static inline void hpfs_unlock(struct super_block *s)
+{
+	struct hpfs_sb_info *sbi = hpfs_sb(s);
+	mutex_unlock(&sbi->hpfs_mutex);
+}
+
+static inline void hpfs_lock_assert(struct super_block *s)
+{
+	struct hpfs_sb_info *sbi = hpfs_sb(s);
+	WARN_ON(!mutex_is_locked(&sbi->hpfs_mutex));
+}
diff --git a/fs/hpfs/inode.c b/fs/hpfs/inode.c
new file mode 100644
index 000000000..1b4fcf760
--- /dev/null
+++ b/fs/hpfs/inode.c
@@ -0,0 +1,318 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/hpfs/inode.c
+ *
+ *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
+ *
+ *  inode VFS functions
+ */
+
+#include <linux/slab.h>
+#include <linux/user_namespace.h>
+#include "hpfs_fn.h"
+
+void hpfs_init_inode(struct inode *i)
+{
+	struct super_block *sb = i->i_sb;
+	struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
+
+	i->i_uid = hpfs_sb(sb)->sb_uid;
+	i->i_gid = hpfs_sb(sb)->sb_gid;
+	i->i_mode = hpfs_sb(sb)->sb_mode;
+	i->i_size = -1;
+	i->i_blocks = -1;
+	
+	hpfs_inode->i_dno = 0;
+	hpfs_inode->i_n_secs = 0;
+	hpfs_inode->i_file_sec = 0;
+	hpfs_inode->i_disk_sec = 0;
+	hpfs_inode->i_dpos = 0;
+	hpfs_inode->i_dsubdno = 0;
+	hpfs_inode->i_ea_mode = 0;
+	hpfs_inode->i_ea_uid = 0;
+	hpfs_inode->i_ea_gid = 0;
+	hpfs_inode->i_ea_size = 0;
+
+	hpfs_inode->i_rddir_off = NULL;
+	hpfs_inode->i_dirty = 0;
+
+	inode_set_ctime(i, 0, 0);
+	inode_set_mtime(i, 0, 0);
+	inode_set_atime(i, 0, 0);
+}
+
+void hpfs_read_inode(struct inode *i)
+{
+	struct buffer_head *bh;
+	struct fnode *fnode;
+	struct super_block *sb = i->i_sb;
+	struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
+	void *ea;
+	int ea_size;
+
+	if (!(fnode = hpfs_map_fnode(sb, i->i_ino, &bh))) {
+		/*i->i_mode |= S_IFREG;
+		i->i_mode &= ~0111;
+		i->i_op = &hpfs_file_iops;
+		i->i_fop = &hpfs_file_ops;
+		clear_nlink(i);*/
+		make_bad_inode(i);
+		return;
+	}
+	if (hpfs_sb(i->i_sb)->sb_eas) {
+		if ((ea = hpfs_get_ea(i->i_sb, fnode, "UID", &ea_size))) {
+			if (ea_size == 2) {
+				i_uid_write(i, le16_to_cpu(*(__le16*)ea));
+				hpfs_inode->i_ea_uid = 1;
+			}
+			kfree(ea);
+		}
+		if ((ea = hpfs_get_ea(i->i_sb, fnode, "GID", &ea_size))) {
+			if (ea_size == 2) {
+				i_gid_write(i, le16_to_cpu(*(__le16*)ea));
+				hpfs_inode->i_ea_gid = 1;
+			}
+			kfree(ea);
+		}
+		if ((ea = hpfs_get_ea(i->i_sb, fnode, "SYMLINK", &ea_size))) {
+			kfree(ea);
+			i->i_mode = S_IFLNK | 0777;
+			i->i_op = &page_symlink_inode_operations;
+			inode_nohighmem(i);
+			i->i_data.a_ops = &hpfs_symlink_aops;
+			set_nlink(i, 1);
+			i->i_size = ea_size;
+			i->i_blocks = 1;
+			brelse(bh);
+			return;
+		}
+		if ((ea = hpfs_get_ea(i->i_sb, fnode, "MODE", &ea_size))) {
+			int rdev = 0;
+			umode_t mode = hpfs_sb(sb)->sb_mode;
+			if (ea_size == 2) {
+				mode = le16_to_cpu(*(__le16*)ea);
+				hpfs_inode->i_ea_mode = 1;
+			}
+			kfree(ea);
+			i->i_mode = mode;
+			if (S_ISBLK(mode) || S_ISCHR(mode)) {
+				if ((ea = hpfs_get_ea(i->i_sb, fnode, "DEV", &ea_size))) {
+					if (ea_size == 4)
+						rdev = le32_to_cpu(*(__le32*)ea);
+					kfree(ea);
+				}
+			}
+			if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
+				brelse(bh);
+				set_nlink(i, 1);
+				i->i_size = 0;
+				i->i_blocks = 1;
+				init_special_inode(i, mode,
+					new_decode_dev(rdev));
+				return;
+			}
+		}
+	}
+	if (fnode_is_dir(fnode)) {
+		int n_dnodes, n_subdirs;
+		i->i_mode |= S_IFDIR;
+		i->i_op = &hpfs_dir_iops;
+		i->i_fop = &hpfs_dir_ops;
+		hpfs_inode->i_parent_dir = le32_to_cpu(fnode->up);
+		hpfs_inode->i_dno = le32_to_cpu(fnode->u.external[0].disk_secno);
+		if (hpfs_sb(sb)->sb_chk >= 2) {
+			struct buffer_head *bh0;
+			if (hpfs_map_fnode(sb, hpfs_inode->i_parent_dir, &bh0)) brelse(bh0);
+		}
+		n_dnodes = 0; n_subdirs = 0;
+		hpfs_count_dnodes(i->i_sb, hpfs_inode->i_dno, &n_dnodes, &n_subdirs, NULL);
+		i->i_blocks = 4 * n_dnodes;
+		i->i_size = 2048 * n_dnodes;
+		set_nlink(i, 2 + n_subdirs);
+	} else {
+		i->i_mode |= S_IFREG;
+		if (!hpfs_inode->i_ea_mode) i->i_mode &= ~0111;
+		i->i_op = &hpfs_file_iops;
+		i->i_fop = &hpfs_file_ops;
+		set_nlink(i, 1);
+		i->i_size = le32_to_cpu(fnode->file_size);
+		i->i_blocks = ((i->i_size + 511) >> 9) + 1;
+		i->i_data.a_ops = &hpfs_aops;
+		hpfs_i(i)->mmu_private = i->i_size;
+	}
+	brelse(bh);
+}
+
+static void hpfs_write_inode_ea(struct inode *i, struct fnode *fnode)
+{
+	struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
+	/*if (le32_to_cpu(fnode->acl_size_l) || le16_to_cpu(fnode->acl_size_s)) {
+		   Some unknown structures like ACL may be in fnode,
+		   we'd better not overwrite them
+		hpfs_error(i->i_sb, "fnode %08x has some unknown HPFS386 structures", i->i_ino);
+	} else*/ if (hpfs_sb(i->i_sb)->sb_eas >= 2) {
+		__le32 ea;
+		if (!uid_eq(i->i_uid, hpfs_sb(i->i_sb)->sb_uid) || hpfs_inode->i_ea_uid) {
+			ea = cpu_to_le32(i_uid_read(i));
+			hpfs_set_ea(i, fnode, "UID", (char*)&ea, 2);
+			hpfs_inode->i_ea_uid = 1;
+		}
+		if (!gid_eq(i->i_gid, hpfs_sb(i->i_sb)->sb_gid) || hpfs_inode->i_ea_gid) {
+			ea = cpu_to_le32(i_gid_read(i));
+			hpfs_set_ea(i, fnode, "GID", (char *)&ea, 2);
+			hpfs_inode->i_ea_gid = 1;
+		}
+		if (!S_ISLNK(i->i_mode))
+			if ((i->i_mode != ((hpfs_sb(i->i_sb)->sb_mode & ~(S_ISDIR(i->i_mode) ? 0 : 0111))
+			  | (S_ISDIR(i->i_mode) ? S_IFDIR : S_IFREG))
+			  && i->i_mode != ((hpfs_sb(i->i_sb)->sb_mode & ~(S_ISDIR(i->i_mode) ? 0222 : 0333))
+			  | (S_ISDIR(i->i_mode) ? S_IFDIR : S_IFREG))) || hpfs_inode->i_ea_mode) {
+				ea = cpu_to_le32(i->i_mode);
+				/* sick, but legal */
+				hpfs_set_ea(i, fnode, "MODE", (char *)&ea, 2);
+				hpfs_inode->i_ea_mode = 1;
+			}
+		if (S_ISBLK(i->i_mode) || S_ISCHR(i->i_mode)) {
+			ea = cpu_to_le32(new_encode_dev(i->i_rdev));
+			hpfs_set_ea(i, fnode, "DEV", (char *)&ea, 4);
+		}
+	}
+}
+
+void hpfs_write_inode(struct inode *i)
+{
+	struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
+	struct inode *parent;
+	if (i->i_ino == hpfs_sb(i->i_sb)->sb_root) return;
+	if (hpfs_inode->i_rddir_off && !icount_read_once(i)) {
+		if (*hpfs_inode->i_rddir_off)
+			pr_err("write_inode: some position still there\n");
+		kfree(hpfs_inode->i_rddir_off);
+		hpfs_inode->i_rddir_off = NULL;
+	}
+	if (!i->i_nlink) {
+		return;
+	}
+	parent = iget_locked(i->i_sb, hpfs_inode->i_parent_dir);
+	if (parent) {
+		hpfs_inode->i_dirty = 0;
+		if (inode_state_read_once(parent) & I_NEW) {
+			hpfs_init_inode(parent);
+			hpfs_read_inode(parent);
+			unlock_new_inode(parent);
+		}
+		hpfs_write_inode_nolock(i);
+		iput(parent);
+	}
+}
+
+void hpfs_write_inode_nolock(struct inode *i)
+{
+	struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
+	struct buffer_head *bh;
+	struct fnode *fnode;
+	struct quad_buffer_head qbh;
+	struct hpfs_dirent *de;
+	if (i->i_ino == hpfs_sb(i->i_sb)->sb_root) return;
+	if (!(fnode = hpfs_map_fnode(i->i_sb, i->i_ino, &bh))) return;
+	if (i->i_ino != hpfs_sb(i->i_sb)->sb_root && i->i_nlink) {
+		if (!(de = map_fnode_dirent(i->i_sb, i->i_ino, fnode, &qbh))) {
+			brelse(bh);
+			return;
+		}
+	} else de = NULL;
+	if (S_ISREG(i->i_mode)) {
+		fnode->file_size = cpu_to_le32(i->i_size);
+		if (de) de->file_size = cpu_to_le32(i->i_size);
+	} else if (S_ISDIR(i->i_mode)) {
+		fnode->file_size = cpu_to_le32(0);
+		if (de) de->file_size = cpu_to_le32(0);
+	}
+	hpfs_write_inode_ea(i, fnode);
+	if (de) {
+		de->write_date = cpu_to_le32(gmt_to_local(i->i_sb, inode_get_mtime_sec(i)));
+		de->read_date = cpu_to_le32(gmt_to_local(i->i_sb, inode_get_atime_sec(i)));
+		de->creation_date = cpu_to_le32(gmt_to_local(i->i_sb, inode_get_ctime_sec(i)));
+		de->read_only = !(i->i_mode & 0222);
+		de->ea_size = cpu_to_le32(hpfs_inode->i_ea_size);
+		hpfs_mark_4buffers_dirty(&qbh);
+		hpfs_brelse4(&qbh);
+	}
+	if (S_ISDIR(i->i_mode)) {
+		if ((de = map_dirent(i, hpfs_inode->i_dno, "\001\001", 2, NULL, &qbh))) {
+			de->write_date = cpu_to_le32(gmt_to_local(i->i_sb, inode_get_mtime_sec(i)));
+			de->read_date = cpu_to_le32(gmt_to_local(i->i_sb, inode_get_atime_sec(i)));
+			de->creation_date = cpu_to_le32(gmt_to_local(i->i_sb, inode_get_ctime_sec(i)));
+			de->read_only = !(i->i_mode & 0222);
+			de->ea_size = cpu_to_le32(/*hpfs_inode->i_ea_size*/0);
+			de->file_size = cpu_to_le32(0);
+			hpfs_mark_4buffers_dirty(&qbh);
+			hpfs_brelse4(&qbh);
+		} else
+			hpfs_error(i->i_sb,
+				"directory %08llx doesn't have '.' entry",
+				i->i_ino);
+	}
+	mark_buffer_dirty(bh);
+	brelse(bh);
+}
+
+int hpfs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
+		 struct iattr *attr)
+{
+	struct inode *inode = d_inode(dentry);
+	int error = -EINVAL;
+
+	hpfs_lock(inode->i_sb);
+	if (inode->i_ino == hpfs_sb(inode->i_sb)->sb_root)
+		goto out_unlock;
+	if ((attr->ia_valid & ATTR_UID) &&
+	    from_kuid(&init_user_ns, attr->ia_uid) >= 0x10000)
+		goto out_unlock;
+	if ((attr->ia_valid & ATTR_GID) &&
+	    from_kgid(&init_user_ns, attr->ia_gid) >= 0x10000)
+		goto out_unlock;
+	if ((attr->ia_valid & ATTR_SIZE) && attr->ia_size > inode->i_size)
+		goto out_unlock;
+
+	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
+	if (error)
+		goto out_unlock;
+
+	if ((attr->ia_valid & ATTR_SIZE) &&
+	    attr->ia_size != i_size_read(inode)) {
+		error = inode_newsize_ok(inode, attr->ia_size);
+		if (error)
+			goto out_unlock;
+
+		truncate_setsize(inode, attr->ia_size);
+		hpfs_truncate(inode);
+	}
+
+	setattr_copy(&nop_mnt_idmap, inode, attr);
+
+	hpfs_write_inode(inode);
+
+ out_unlock:
+	hpfs_unlock(inode->i_sb);
+	return error;
+}
+
+void hpfs_write_if_changed(struct inode *inode)
+{
+	struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
+
+	if (hpfs_inode->i_dirty)
+		hpfs_write_inode(inode);
+}
+
+void hpfs_evict_inode(struct inode *inode)
+{
+	truncate_inode_pages_final(&inode->i_data);
+	clear_inode(inode);
+	if (!inode->i_nlink) {
+		hpfs_lock(inode->i_sb);
+		hpfs_remove_fnode(inode->i_sb, inode->i_ino);
+		hpfs_unlock(inode->i_sb);
+	}
+}
diff --git a/fs/hpfs/map.c b/fs/hpfs/map.c
new file mode 100644
index 000000000..be7323350
--- /dev/null
+++ b/fs/hpfs/map.c
@@ -0,0 +1,335 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/hpfs/map.c
+ *
+ *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
+ *
+ *  mapping structures to memory with some minimal checks
+ */
+
+#include "hpfs_fn.h"
+
+__le32 *hpfs_map_dnode_bitmap(struct super_block *s, struct quad_buffer_head *qbh)
+{
+	return hpfs_map_4sectors(s, hpfs_sb(s)->sb_dmap, qbh, 0);
+}
+
+__le32 *hpfs_map_bitmap(struct super_block *s, unsigned bmp_block,
+			 struct quad_buffer_head *qbh, char *id)
+{
+	secno sec;
+	__le32 *ret;
+	unsigned n_bands = (hpfs_sb(s)->sb_fs_size + 0x3fff) >> 14;
+	if (hpfs_sb(s)->sb_chk) if (bmp_block >= n_bands) {
+		hpfs_error(s, "hpfs_map_bitmap called with bad parameter: %08x at %s", bmp_block, id);
+		return NULL;
+	}
+	sec = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block]);
+	if (!sec || sec > hpfs_sb(s)->sb_fs_size-4) {
+		hpfs_error(s, "invalid bitmap block pointer %08x -> %08x at %s", bmp_block, sec, id);
+		return NULL;
+	}
+	ret = hpfs_map_4sectors(s, sec, qbh, 4);
+	if (ret) hpfs_prefetch_bitmap(s, bmp_block + 1);
+	return ret;
+}
+
+void hpfs_prefetch_bitmap(struct super_block *s, unsigned bmp_block)
+{
+	unsigned to_prefetch, next_prefetch;
+	unsigned n_bands = (hpfs_sb(s)->sb_fs_size + 0x3fff) >> 14;
+	if (unlikely(bmp_block >= n_bands))
+		return;
+	to_prefetch = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block]);
+	if (unlikely(bmp_block + 1 >= n_bands))
+		next_prefetch = 0;
+	else
+		next_prefetch = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block + 1]);
+	hpfs_prefetch_sectors(s, to_prefetch, 4 + 4 * (to_prefetch + 4 == next_prefetch));
+}
+
+/*
+ * Load first code page into kernel memory, return pointer to 256-byte array,
+ * first 128 bytes are uppercasing table for chars 128-255, next 128 bytes are
+ * lowercasing table
+ */
+
+unsigned char *hpfs_load_code_page(struct super_block *s, secno cps)
+{
+	struct buffer_head *bh;
+	secno cpds;
+	unsigned cpi;
+	unsigned char *ptr;
+	unsigned char *cp_table;
+	int i;
+	struct code_page_data *cpd;
+	struct code_page_directory *cp = hpfs_map_sector(s, cps, &bh, 0);
+	if (!cp) return NULL;
+	if (le32_to_cpu(cp->magic) != CP_DIR_MAGIC) {
+		pr_err("Code page directory magic doesn't match (magic = %08x)\n",
+			le32_to_cpu(cp->magic));
+		brelse(bh);
+		return NULL;
+	}
+	if (!le32_to_cpu(cp->n_code_pages)) {
+		pr_err("n_code_pages == 0\n");
+		brelse(bh);
+		return NULL;
+	}
+	cpds = le32_to_cpu(cp->array[0].code_page_data);
+	cpi = le16_to_cpu(cp->array[0].index);
+	brelse(bh);
+
+	if (cpi >= 3) {
+		pr_err("Code page index out of array\n");
+		return NULL;
+	}
+	
+	if (!(cpd = hpfs_map_sector(s, cpds, &bh, 0))) return NULL;
+	if (le16_to_cpu(cpd->offs[cpi]) > 0x178) {
+		pr_err("Code page index out of sector\n");
+		brelse(bh);
+		return NULL;
+	}
+	ptr = (unsigned char *)cpd + le16_to_cpu(cpd->offs[cpi]) + 6;
+	if (!(cp_table = kmalloc(256, GFP_KERNEL))) {
+		pr_err("out of memory for code page table\n");
+		brelse(bh);
+		return NULL;
+	}
+	memcpy(cp_table, ptr, 128);
+	brelse(bh);
+
+	/* Try to build lowercasing table from uppercasing one */
+
+	for (i=128; i<256; i++) cp_table[i]=i;
+	for (i=128; i<256; i++) if (cp_table[i-128]!=i && cp_table[i-128]>=128)
+		cp_table[cp_table[i-128]] = i;
+	
+	return cp_table;
+}
+
+__le32 *hpfs_load_bitmap_directory(struct super_block *s, secno bmp)
+{
+	struct buffer_head *bh;
+	int n = (hpfs_sb(s)->sb_fs_size + 0x200000 - 1) >> 21;
+	int i;
+	__le32 *b;
+	if (!(b = kmalloc_array(n, 512, GFP_KERNEL))) {
+		pr_err("can't allocate memory for bitmap directory\n");
+		return NULL;
+	}	
+	for (i=0;i<n;i++) {
+		__le32 *d = hpfs_map_sector(s, bmp+i, &bh, n - i - 1);
+		if (!d) {
+			kfree(b);
+			return NULL;
+		}
+		memcpy((char *)b + 512 * i, d, 512);
+		brelse(bh);
+	}
+	return b;
+}
+
+void hpfs_load_hotfix_map(struct super_block *s, struct hpfs_spare_block *spareblock)
+{
+	struct quad_buffer_head qbh;
+	__le32 *directory;
+	u32 n_hotfixes, n_used_hotfixes;
+	unsigned i;
+
+	n_hotfixes = le32_to_cpu(spareblock->n_spares);
+	n_used_hotfixes = le32_to_cpu(spareblock->n_spares_used);
+
+	if (n_hotfixes > 256 || n_used_hotfixes > n_hotfixes) {
+		hpfs_error(s, "invalid number of hotfixes: %u, used: %u", n_hotfixes, n_used_hotfixes);
+		return;
+	}
+	if (!(directory = hpfs_map_4sectors(s, le32_to_cpu(spareblock->hotfix_map), &qbh, 0))) {
+		hpfs_error(s, "can't load hotfix map");
+		return;
+	}
+	for (i = 0; i < n_used_hotfixes; i++) {
+		hpfs_sb(s)->hotfix_from[i] = le32_to_cpu(directory[i]);
+		hpfs_sb(s)->hotfix_to[i] = le32_to_cpu(directory[n_hotfixes + i]);
+	}
+	hpfs_sb(s)->n_hotfixes = n_used_hotfixes;
+	hpfs_brelse4(&qbh);
+}
+
+/*
+ * Load fnode to memory
+ */
+
+struct fnode *hpfs_map_fnode(struct super_block *s, ino_t ino, struct buffer_head **bhp)
+{
+	struct fnode *fnode;
+	if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, ino, 1, "fnode")) {
+		return NULL;
+	}
+	if ((fnode = hpfs_map_sector(s, ino, bhp, FNODE_RD_AHEAD))) {
+		if (hpfs_sb(s)->sb_chk) {
+			struct extended_attribute *ea;
+			struct extended_attribute *ea_end;
+			if (le32_to_cpu(fnode->magic) != FNODE_MAGIC) {
+				hpfs_error(s, "bad magic on fnode %08lx",
+					(unsigned long)ino);
+				goto bail;
+			}
+			if (!fnode_is_dir(fnode)) {
+				if ((unsigned)fnode->btree.n_used_nodes + (unsigned)fnode->btree.n_free_nodes !=
+				    (bp_internal(GET_BTREE_PTR(&fnode->btree)) ? 12 : 8)) {
+					hpfs_error(s,
+					   "bad number of nodes in fnode %08lx",
+					    (unsigned long)ino);
+					goto bail;
+				}
+				if (le16_to_cpu(fnode->btree.first_free) !=
+				    8 + fnode->btree.n_used_nodes * (bp_internal(GET_BTREE_PTR(&fnode->btree)) ? 8 : 12)) {
+					hpfs_error(s,
+					    "bad first_free pointer in fnode %08lx",
+					    (unsigned long)ino);
+					goto bail;
+				}
+			}
+			if (le16_to_cpu(fnode->ea_size_s) && (le16_to_cpu(fnode->ea_offs) < 0xc4 ||
+			   le16_to_cpu(fnode->ea_offs) + le16_to_cpu(fnode->acl_size_s) + le16_to_cpu(fnode->ea_size_s) > 0x200)) {
+				hpfs_error(s,
+					"bad EA info in fnode %08lx: ea_offs == %04x ea_size_s == %04x",
+					(unsigned long)ino,
+					le16_to_cpu(fnode->ea_offs), le16_to_cpu(fnode->ea_size_s));
+				goto bail;
+			}
+			ea = fnode_ea(fnode);
+			ea_end = fnode_end_ea(fnode);
+			while (ea != ea_end) {
+				if (ea > ea_end) {
+					hpfs_error(s, "bad EA in fnode %08lx",
+						(unsigned long)ino);
+					goto bail;
+				}
+				ea = next_ea(ea);
+			}
+		}
+	}
+	return fnode;
+	bail:
+	brelse(*bhp);
+	return NULL;
+}
+
+struct anode *hpfs_map_anode(struct super_block *s, anode_secno ano, struct buffer_head **bhp)
+{
+	struct anode *anode;
+	if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, ano, 1, "anode")) return NULL;
+	if ((anode = hpfs_map_sector(s, ano, bhp, ANODE_RD_AHEAD)))
+		if (hpfs_sb(s)->sb_chk) {
+			if (le32_to_cpu(anode->magic) != ANODE_MAGIC) {
+				hpfs_error(s, "bad magic on anode %08x", ano);
+				goto bail;
+			}
+			if (le32_to_cpu(anode->self) != ano) {
+				hpfs_error(s, "self pointer invalid on anode %08x", ano);
+				goto bail;
+			}
+			if ((unsigned)anode->btree.n_used_nodes + (unsigned)anode->btree.n_free_nodes !=
+			    (bp_internal(GET_BTREE_PTR(&anode->btree)) ? 60 : 40)) {
+				hpfs_error(s, "bad number of nodes in anode %08x", ano);
+				goto bail;
+			}
+			if (le16_to_cpu(anode->btree.first_free) !=
+			    8 + anode->btree.n_used_nodes * (bp_internal(GET_BTREE_PTR(&anode->btree)) ? 8 : 12)) {
+				hpfs_error(s, "bad first_free pointer in anode %08x", ano);
+				goto bail;
+			}
+		}
+	return anode;
+	bail:
+	brelse(*bhp);
+	return NULL;
+}
+
+/*
+ * Load dnode to memory and do some checks
+ */
+
+struct dnode *hpfs_map_dnode(struct super_block *s, unsigned secno,
+			     struct quad_buffer_head *qbh)
+{
+	struct dnode *dnode;
+	if (hpfs_sb(s)->sb_chk) {
+		if (hpfs_chk_sectors(s, secno, 4, "dnode")) return NULL;
+		if (secno & 3) {
+			hpfs_error(s, "dnode %08x not byte-aligned", secno);
+			return NULL;
+		}	
+	}
+	if ((dnode = hpfs_map_4sectors(s, secno, qbh, DNODE_RD_AHEAD)))
+		if (hpfs_sb(s)->sb_chk) {
+			unsigned p, pp = 0;
+			unsigned char *d = (unsigned char *)dnode;
+			int b = 0;
+			if (le32_to_cpu(dnode->magic) != DNODE_MAGIC) {
+				hpfs_error(s, "bad magic on dnode %08x", secno);
+				goto bail;
+			}
+			if (le32_to_cpu(dnode->self) != secno)
+				hpfs_error(s, "bad self pointer on dnode %08x self = %08x", secno, le32_to_cpu(dnode->self));
+			/* Check dirents - bad dirents would cause infinite
+			   loops or shooting to memory */
+			if (le32_to_cpu(dnode->first_free) > 2048) {
+				hpfs_error(s, "dnode %08x has first_free == %08x", secno, le32_to_cpu(dnode->first_free));
+				goto bail;
+			}
+			for (p = 20; p < le32_to_cpu(dnode->first_free); p += d[p] + (d[p+1] << 8)) {
+				struct hpfs_dirent *de = (struct hpfs_dirent *)((char *)dnode + p);
+				if (le16_to_cpu(de->length) > 292 || (le16_to_cpu(de->length) < 32) || (le16_to_cpu(de->length) & 3) || p + le16_to_cpu(de->length) > 2048) {
+					hpfs_error(s, "bad dirent size in dnode %08x, dirent %03x, last %03x", secno, p, pp);
+					goto bail;
+				}
+				if (((31 + de->namelen + de->down*4 + 3) & ~3) != le16_to_cpu(de->length)) {
+					if (((31 + de->namelen + de->down*4 + 3) & ~3) < le16_to_cpu(de->length) && s->s_flags & SB_RDONLY) goto ok;
+					hpfs_error(s, "namelen does not match dirent size in dnode %08x, dirent %03x, last %03x", secno, p, pp);
+					goto bail;
+				}
+				ok:
+				if (hpfs_sb(s)->sb_chk >= 2) b |= 1 << de->down;
+				if (de->down) if (de_down_pointer(de) < 0x10) {
+					hpfs_error(s, "bad down pointer in dnode %08x, dirent %03x, last %03x", secno, p, pp);
+					goto bail;
+				}
+				pp = p;
+				
+			}
+			if (p != le32_to_cpu(dnode->first_free)) {
+				hpfs_error(s, "size on last dirent does not match first_free; dnode %08x", secno);
+				goto bail;
+			}
+			if (d[pp + 30] != 1 || d[pp + 31] != 255) {
+				hpfs_error(s, "dnode %08x does not end with \\377 entry", secno);
+				goto bail;
+			}
+			if (b == 3)
+				pr_err("unbalanced dnode tree, dnode %08x; see hpfs.txt 4 more info\n",
+					secno);
+		}
+	return dnode;
+	bail:
+	hpfs_brelse4(qbh);
+	return NULL;
+}
+
+dnode_secno hpfs_fnode_dno(struct super_block *s, ino_t ino)
+{
+	struct buffer_head *bh;
+	struct fnode *fnode;
+	dnode_secno dno;
+
+	fnode = hpfs_map_fnode(s, ino, &bh);
+	if (!fnode)
+		return 0;
+
+	dno = le32_to_cpu(fnode->u.external[0].disk_secno);
+	brelse(bh);
+	return dno;
+}
diff --git a/fs/hpfs/name.c b/fs/hpfs/name.c
new file mode 100644
index 000000000..ef7ba77f3
--- /dev/null
+++ b/fs/hpfs/name.c
@@ -0,0 +1,114 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/hpfs/name.c
+ *
+ *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
+ *
+ *  operations with filenames
+ */
+
+#include "hpfs_fn.h"
+
+static inline int not_allowed_char(unsigned char c)
+{
+	return c<' ' || c=='"' || c=='*' || c=='/' || c==':' || c=='<' ||
+	      c=='>' || c=='?' || c=='\\' || c=='|';
+}
+
+static inline int no_dos_char(unsigned char c)
+{	/* Characters that are allowed in HPFS but not in DOS */
+	return c=='+' || c==',' || c==';' || c=='=' || c=='[' || c==']';
+}
+
+static inline unsigned char upcase(unsigned char *dir, unsigned char a)
+{
+	if (a<128 || a==255) return a>='a' && a<='z' ? a - 0x20 : a;
+	if (!dir) return a;
+	return dir[a-128];
+}
+
+unsigned char hpfs_upcase(unsigned char *dir, unsigned char a)
+{
+	return upcase(dir, a);
+}
+
+static inline unsigned char locase(unsigned char *dir, unsigned char a)
+{
+	if (a<128 || a==255) return a>='A' && a<='Z' ? a + 0x20 : a;
+	if (!dir) return a;
+	return dir[a];
+}
+
+int hpfs_chk_name(const unsigned char *name, unsigned *len)
+{
+	int i;
+	if (*len > 254) return -ENAMETOOLONG;
+	hpfs_adjust_length(name, len);
+	if (!*len) return -EINVAL;
+	for (i = 0; i < *len; i++) if (not_allowed_char(name[i])) return -EINVAL;
+	if (*len == 1) if (name[0] == '.') return -EINVAL;
+	if (*len == 2) if (name[0] == '.' && name[1] == '.') return -EINVAL;
+	return 0;
+}
+
+unsigned char *hpfs_translate_name(struct super_block *s, unsigned char *from,
+			  unsigned len, int lc, int lng)
+{
+	unsigned char *to;
+	int i;
+	if (hpfs_sb(s)->sb_chk >= 2) if (hpfs_is_name_long(from, len) != lng) {
+		pr_err("Long name flag mismatch - name ");
+		for (i = 0; i < len; i++)
+			pr_cont("%c", from[i]);
+		pr_cont(" misidentified as %s.\n", lng ? "short" : "long");
+		pr_err("It's nothing serious. It could happen because of bug in OS/2.\nSet checks=normal to disable this message.\n");
+	}
+	if (!lc) return from;
+	if (!(to = kmalloc(len, GFP_KERNEL))) {
+		pr_err("can't allocate memory for name conversion buffer\n");
+		return from;
+	}
+	for (i = 0; i < len; i++) to[i] = locase(hpfs_sb(s)->sb_cp_table,from[i]);
+	return to;
+}
+
+int hpfs_compare_names(struct super_block *s,
+		       const unsigned char *n1, unsigned l1,
+		       const unsigned char *n2, unsigned l2, int last)
+{
+	unsigned l = l1 < l2 ? l1 : l2;
+	unsigned i;
+	if (last) return -1;
+	for (i = 0; i < l; i++) {
+		unsigned char c1 = upcase(hpfs_sb(s)->sb_cp_table,n1[i]);
+		unsigned char c2 = upcase(hpfs_sb(s)->sb_cp_table,n2[i]);
+		if (c1 < c2) return -1;
+		if (c1 > c2) return 1;
+	}
+	if (l1 < l2) return -1;
+	if (l1 > l2) return 1;
+	return 0;
+}
+
+int hpfs_is_name_long(const unsigned char *name, unsigned len)
+{
+	int i,j;
+	for (i = 0; i < len && name[i] != '.'; i++)
+		if (no_dos_char(name[i])) return 1;
+	if (!i || i > 8) return 1;
+	if (i == len) return 0;
+	for (j = i + 1; j < len; j++)
+		if (name[j] == '.' || no_dos_char(name[i])) return 1;
+	return j - i > 4;
+}
+
+/* OS/2 clears dots and spaces at the end of file name, so we have to */
+
+void hpfs_adjust_length(const unsigned char *name, unsigned *len)
+{
+	if (!*len) return;
+	if (*len == 1 && name[0] == '.') return;
+	if (*len == 2 && name[0] == '.' && name[1] == '.') return;
+	while (*len && (name[*len - 1] == '.' || name[*len - 1] == ' '))
+		(*len)--;
+}
diff --git a/fs/hpfs/namei.c b/fs/hpfs/namei.c
new file mode 100644
index 000000000..9446f4038
--- /dev/null
+++ b/fs/hpfs/namei.c
@@ -0,0 +1,621 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/hpfs/namei.c
+ *
+ *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
+ *
+ *  adding & removing files & directories
+ */
+#include <linux/sched.h>
+#include "hpfs_fn.h"
+
+static void hpfs_update_directory_times(struct inode *dir)
+{
+	time64_t t = local_to_gmt(dir->i_sb, local_get_seconds(dir->i_sb));
+	if (t == inode_get_mtime_sec(dir) &&
+	    t == inode_get_ctime_sec(dir))
+		return;
+	inode_set_mtime_to_ts(dir, inode_set_ctime(dir, t, 0));
+	hpfs_write_inode_nolock(dir);
+}
+
+static struct dentry *hpfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
+				 struct dentry *dentry, umode_t mode)
+{
+	const unsigned char *name = dentry->d_name.name;
+	unsigned len = dentry->d_name.len;
+	struct quad_buffer_head qbh0;
+	struct buffer_head *bh;
+	struct hpfs_dirent *de;
+	struct fnode *fnode;
+	struct dnode *dnode;
+	struct inode *result;
+	fnode_secno fno;
+	dnode_secno dno;
+	int r;
+	struct hpfs_dirent dee;
+	int err;
+	if ((err = hpfs_chk_name(name, &len))) return ERR_PTR(err==-ENOENT ? -EINVAL : err);
+	hpfs_lock(dir->i_sb);
+	err = -ENOSPC;
+	fnode = hpfs_alloc_fnode(dir->i_sb, hpfs_i(dir)->i_dno, &fno, &bh);
+	if (!fnode)
+		goto bail;
+	dnode = hpfs_alloc_dnode(dir->i_sb, fno, &dno, &qbh0);
+	if (!dnode)
+		goto bail1;
+	memset(&dee, 0, sizeof dee);
+	dee.directory = 1;
+	if (!(mode & 0222)) dee.read_only = 1;
+	/*dee.archive = 0;*/
+	dee.hidden = name[0] == '.';
+	dee.fnode = cpu_to_le32(fno);
+	dee.creation_date = dee.write_date = dee.read_date = cpu_to_le32(local_get_seconds(dir->i_sb));
+	result = new_inode(dir->i_sb);
+	if (!result) {
+		err = -ENOMEM;
+		goto bail2;
+	}
+	hpfs_init_inode(result);
+	result->i_ino = fno;
+	hpfs_i(result)->i_parent_dir = dir->i_ino;
+	hpfs_i(result)->i_dno = dno;
+	inode_set_mtime_to_ts(result,
+			      inode_set_atime_to_ts(result, inode_set_ctime(result, local_to_gmt(dir->i_sb, le32_to_cpu(dee.creation_date)), 0)));
+	hpfs_i(result)->i_ea_size = 0;
+	result->i_mode |= S_IFDIR;
+	result->i_op = &hpfs_dir_iops;
+	result->i_fop = &hpfs_dir_ops;
+	result->i_blocks = 4;
+	result->i_size = 2048;
+	set_nlink(result, 2);
+	if (dee.read_only)
+		result->i_mode &= ~0222;
+
+	r = hpfs_add_dirent(dir, name, len, &dee);
+	if (r == 1)
+		goto bail3;
+	if (r == -1) {
+		err = -EEXIST;
+		goto bail3;
+	}
+	fnode->len = len;
+	memcpy(fnode->name, name, len > 15 ? 15 : len);
+	fnode->up = cpu_to_le32(dir->i_ino);
+	fnode->flags |= FNODE_dir;
+	fnode->btree.n_free_nodes = 7;
+	fnode->btree.n_used_nodes = 1;
+	fnode->btree.first_free = cpu_to_le16(0x14);
+	fnode->u.external[0].disk_secno = cpu_to_le32(dno);
+	fnode->u.external[0].file_secno = cpu_to_le32(-1);
+	dnode->root_dnode = 1;
+	dnode->up = cpu_to_le32(fno);
+	de = hpfs_add_de(dir->i_sb, dnode, "\001\001", 2, 0);
+	de->creation_date = de->write_date = de->read_date = cpu_to_le32(local_get_seconds(dir->i_sb));
+	if (!(mode & 0222)) de->read_only = 1;
+	de->first = de->directory = 1;
+	/*de->hidden = de->system = 0;*/
+	de->fnode = cpu_to_le32(fno);
+	mark_buffer_dirty(bh);
+	brelse(bh);
+	hpfs_mark_4buffers_dirty(&qbh0);
+	hpfs_brelse4(&qbh0);
+	inc_nlink(dir);
+	insert_inode_hash(result);
+
+	if (!uid_eq(result->i_uid, current_fsuid()) ||
+	    !gid_eq(result->i_gid, current_fsgid()) ||
+	    result->i_mode != mode) {
+		result->i_uid = current_fsuid();
+		result->i_gid = current_fsgid();
+		result->i_mode = mode;
+		hpfs_write_inode_nolock(result);
+	}
+	hpfs_update_directory_times(dir);
+	d_instantiate(dentry, result);
+	hpfs_unlock(dir->i_sb);
+	return NULL;
+bail3:
+	iput(result);
+bail2:
+	hpfs_brelse4(&qbh0);
+	hpfs_free_dnode(dir->i_sb, dno);
+bail1:
+	brelse(bh);
+	hpfs_free_sectors(dir->i_sb, fno, 1);
+bail:
+	hpfs_unlock(dir->i_sb);
+	return ERR_PTR(err);
+}
+
+static int hpfs_create(struct mnt_idmap *idmap, struct inode *dir,
+		       struct dentry *dentry, umode_t mode)
+{
+	const unsigned char *name = dentry->d_name.name;
+	unsigned len = dentry->d_name.len;
+	struct inode *result = NULL;
+	struct buffer_head *bh;
+	struct fnode *fnode;
+	fnode_secno fno;
+	int r;
+	struct hpfs_dirent dee;
+	int err;
+	if ((err = hpfs_chk_name(name, &len)))
+		return err==-ENOENT ? -EINVAL : err;
+	hpfs_lock(dir->i_sb);
+	err = -ENOSPC;
+	fnode = hpfs_alloc_fnode(dir->i_sb, hpfs_i(dir)->i_dno, &fno, &bh);
+	if (!fnode)
+		goto bail;
+	memset(&dee, 0, sizeof dee);
+	if (!(mode & 0222)) dee.read_only = 1;
+	dee.archive = 1;
+	dee.hidden = name[0] == '.';
+	dee.fnode = cpu_to_le32(fno);
+	dee.creation_date = dee.write_date = dee.read_date = cpu_to_le32(local_get_seconds(dir->i_sb));
+
+	result = new_inode(dir->i_sb);
+	if (!result) {
+		err = -ENOMEM;
+		goto bail1;
+	}
+	hpfs_init_inode(result);
+	result->i_ino = fno;
+	result->i_mode |= S_IFREG;
+	result->i_mode &= ~0111;
+	result->i_op = &hpfs_file_iops;
+	result->i_fop = &hpfs_file_ops;
+	set_nlink(result, 1);
+	hpfs_i(result)->i_parent_dir = dir->i_ino;
+	inode_set_mtime_to_ts(result,
+			      inode_set_atime_to_ts(result, inode_set_ctime(result, local_to_gmt(dir->i_sb, le32_to_cpu(dee.creation_date)), 0)));
+	hpfs_i(result)->i_ea_size = 0;
+	if (dee.read_only)
+		result->i_mode &= ~0222;
+	result->i_blocks = 1;
+	result->i_size = 0;
+	result->i_data.a_ops = &hpfs_aops;
+	hpfs_i(result)->mmu_private = 0;
+
+	r = hpfs_add_dirent(dir, name, len, &dee);
+	if (r == 1)
+		goto bail2;
+	if (r == -1) {
+		err = -EEXIST;
+		goto bail2;
+	}
+	fnode->len = len;
+	memcpy(fnode->name, name, len > 15 ? 15 : len);
+	fnode->up = cpu_to_le32(dir->i_ino);
+	mark_buffer_dirty(bh);
+	brelse(bh);
+
+	insert_inode_hash(result);
+
+	if (!uid_eq(result->i_uid, current_fsuid()) ||
+	    !gid_eq(result->i_gid, current_fsgid()) ||
+	    result->i_mode != (mode | S_IFREG)) {
+		result->i_uid = current_fsuid();
+		result->i_gid = current_fsgid();
+		result->i_mode = mode | S_IFREG;
+		hpfs_write_inode_nolock(result);
+	}
+	hpfs_update_directory_times(dir);
+	d_instantiate(dentry, result);
+	hpfs_unlock(dir->i_sb);
+	return 0;
+
+bail2:
+	iput(result);
+bail1:
+	brelse(bh);
+	hpfs_free_sectors(dir->i_sb, fno, 1);
+bail:
+	hpfs_unlock(dir->i_sb);
+	return err;
+}
+
+static int hpfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
+		      struct dentry *dentry, umode_t mode, dev_t rdev)
+{
+	const unsigned char *name = dentry->d_name.name;
+	unsigned len = dentry->d_name.len;
+	struct buffer_head *bh;
+	struct fnode *fnode;
+	fnode_secno fno;
+	int r;
+	struct hpfs_dirent dee;
+	struct inode *result = NULL;
+	int err;
+	if ((err = hpfs_chk_name(name, &len))) return err==-ENOENT ? -EINVAL : err;
+	if (hpfs_sb(dir->i_sb)->sb_eas < 2) return -EPERM;
+	hpfs_lock(dir->i_sb);
+	err = -ENOSPC;
+	fnode = hpfs_alloc_fnode(dir->i_sb, hpfs_i(dir)->i_dno, &fno, &bh);
+	if (!fnode)
+		goto bail;
+	memset(&dee, 0, sizeof dee);
+	if (!(mode & 0222)) dee.read_only = 1;
+	dee.archive = 1;
+	dee.hidden = name[0] == '.';
+	dee.fnode = cpu_to_le32(fno);
+	dee.creation_date = dee.write_date = dee.read_date = cpu_to_le32(local_get_seconds(dir->i_sb));
+
+	result = new_inode(dir->i_sb);
+	if (!result) {
+		err = -ENOMEM;
+		goto bail1;
+	}
+	hpfs_init_inode(result);
+	result->i_ino = fno;
+	hpfs_i(result)->i_parent_dir = dir->i_ino;
+	inode_set_mtime_to_ts(result,
+			      inode_set_atime_to_ts(result, inode_set_ctime(result, local_to_gmt(dir->i_sb, le32_to_cpu(dee.creation_date)), 0)));
+	hpfs_i(result)->i_ea_size = 0;
+	result->i_uid = current_fsuid();
+	result->i_gid = current_fsgid();
+	set_nlink(result, 1);
+	result->i_size = 0;
+	result->i_blocks = 1;
+	init_special_inode(result, mode, rdev);
+
+	r = hpfs_add_dirent(dir, name, len, &dee);
+	if (r == 1)
+		goto bail2;
+	if (r == -1) {
+		err = -EEXIST;
+		goto bail2;
+	}
+	fnode->len = len;
+	memcpy(fnode->name, name, len > 15 ? 15 : len);
+	fnode->up = cpu_to_le32(dir->i_ino);
+	mark_buffer_dirty(bh);
+
+	insert_inode_hash(result);
+
+	hpfs_write_inode_nolock(result);
+	hpfs_update_directory_times(dir);
+	d_instantiate(dentry, result);
+	brelse(bh);
+	hpfs_unlock(dir->i_sb);
+	return 0;
+bail2:
+	iput(result);
+bail1:
+	brelse(bh);
+	hpfs_free_sectors(dir->i_sb, fno, 1);
+bail:
+	hpfs_unlock(dir->i_sb);
+	return err;
+}
+
+static int hpfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
+			struct dentry *dentry, const char *symlink)
+{
+	const unsigned char *name = dentry->d_name.name;
+	unsigned len = dentry->d_name.len;
+	struct buffer_head *bh;
+	struct fnode *fnode;
+	fnode_secno fno;
+	int r;
+	struct hpfs_dirent dee;
+	struct inode *result;
+	int err;
+	if ((err = hpfs_chk_name(name, &len))) return err==-ENOENT ? -EINVAL : err;
+	hpfs_lock(dir->i_sb);
+	if (hpfs_sb(dir->i_sb)->sb_eas < 2) {
+		hpfs_unlock(dir->i_sb);
+		return -EPERM;
+	}
+	err = -ENOSPC;
+	fnode = hpfs_alloc_fnode(dir->i_sb, hpfs_i(dir)->i_dno, &fno, &bh);
+	if (!fnode)
+		goto bail;
+	memset(&dee, 0, sizeof dee);
+	dee.archive = 1;
+	dee.hidden = name[0] == '.';
+	dee.fnode = cpu_to_le32(fno);
+	dee.creation_date = dee.write_date = dee.read_date = cpu_to_le32(local_get_seconds(dir->i_sb));
+
+	result = new_inode(dir->i_sb);
+	if (!result) {
+		err = -ENOMEM;
+		goto bail1;
+	}
+	result->i_ino = fno;
+	hpfs_init_inode(result);
+	hpfs_i(result)->i_parent_dir = dir->i_ino;
+	inode_set_mtime_to_ts(result,
+			      inode_set_atime_to_ts(result, inode_set_ctime(result, local_to_gmt(dir->i_sb, le32_to_cpu(dee.creation_date)), 0)));
+	hpfs_i(result)->i_ea_size = 0;
+	result->i_mode = S_IFLNK | 0777;
+	result->i_uid = current_fsuid();
+	result->i_gid = current_fsgid();
+	result->i_blocks = 1;
+	set_nlink(result, 1);
+	result->i_size = strlen(symlink);
+	inode_nohighmem(result);
+	result->i_op = &page_symlink_inode_operations;
+	result->i_data.a_ops = &hpfs_symlink_aops;
+
+	r = hpfs_add_dirent(dir, name, len, &dee);
+	if (r == 1)
+		goto bail2;
+	if (r == -1) {
+		err = -EEXIST;
+		goto bail2;
+	}
+	fnode->len = len;
+	memcpy(fnode->name, name, len > 15 ? 15 : len);
+	fnode->up = cpu_to_le32(dir->i_ino);
+	hpfs_set_ea(result, fnode, "SYMLINK", symlink, strlen(symlink));
+	mark_buffer_dirty(bh);
+	brelse(bh);
+
+	insert_inode_hash(result);
+
+	hpfs_write_inode_nolock(result);
+	hpfs_update_directory_times(dir);
+	d_instantiate(dentry, result);
+	hpfs_unlock(dir->i_sb);
+	return 0;
+bail2:
+	iput(result);
+bail1:
+	brelse(bh);
+	hpfs_free_sectors(dir->i_sb, fno, 1);
+bail:
+	hpfs_unlock(dir->i_sb);
+	return err;
+}
+
+static int hpfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+	const unsigned char *name = dentry->d_name.name;
+	unsigned len = dentry->d_name.len;
+	struct quad_buffer_head qbh;
+	struct hpfs_dirent *de;
+	struct inode *inode = d_inode(dentry);
+	dnode_secno dno;
+	int r;
+	int err;
+
+	hpfs_lock(dir->i_sb);
+	hpfs_adjust_length(name, &len);
+
+	err = -ENOENT;
+	de = map_dirent(dir, hpfs_i(dir)->i_dno, name, len, &dno, &qbh);
+	if (!de)
+		goto out;
+
+	err = -EPERM;
+	if (de->first)
+		goto out1;
+
+	err = -EISDIR;
+	if (de->directory)
+		goto out1;
+
+	r = hpfs_remove_dirent(dir, dno, de, &qbh, 1);
+	switch (r) {
+	case 1:
+		hpfs_error(dir->i_sb, "there was error when removing dirent");
+		err = -EFSERROR;
+		break;
+	case 2:		/* no space for deleting */
+		err = -ENOSPC;
+		break;
+	default:
+		drop_nlink(inode);
+		err = 0;
+	}
+	goto out;
+
+out1:
+	hpfs_brelse4(&qbh);
+out:
+	if (!err)
+		hpfs_update_directory_times(dir);
+	hpfs_unlock(dir->i_sb);
+	return err;
+}
+
+static int hpfs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+	const unsigned char *name = dentry->d_name.name;
+	unsigned len = dentry->d_name.len;
+	struct quad_buffer_head qbh;
+	struct hpfs_dirent *de;
+	struct inode *inode = d_inode(dentry);
+	dnode_secno dno;
+	int n_items = 0;
+	int err;
+	int r;
+
+	hpfs_adjust_length(name, &len);
+	hpfs_lock(dir->i_sb);
+	err = -ENOENT;
+	de = map_dirent(dir, hpfs_i(dir)->i_dno, name, len, &dno, &qbh);
+	if (!de)
+		goto out;
+
+	err = -EPERM;
+	if (de->first)
+		goto out1;
+
+	err = -ENOTDIR;
+	if (!de->directory)
+		goto out1;
+
+	hpfs_count_dnodes(dir->i_sb, hpfs_i(inode)->i_dno, NULL, NULL, &n_items);
+	err = -ENOTEMPTY;
+	if (n_items)
+		goto out1;
+
+	r = hpfs_remove_dirent(dir, dno, de, &qbh, 1);
+	switch (r) {
+	case 1:
+		hpfs_error(dir->i_sb, "there was error when removing dirent");
+		err = -EFSERROR;
+		break;
+	case 2:
+		err = -ENOSPC;
+		break;
+	default:
+		drop_nlink(dir);
+		clear_nlink(inode);
+		err = 0;
+	}
+	goto out;
+out1:
+	hpfs_brelse4(&qbh);
+out:
+	if (!err)
+		hpfs_update_directory_times(dir);
+	hpfs_unlock(dir->i_sb);
+	return err;
+}
+
+static int hpfs_symlink_read_folio(struct file *file, struct folio *folio)
+{
+	char *link = folio_address(folio);
+	struct inode *i = folio->mapping->host;
+	struct fnode *fnode;
+	struct buffer_head *bh;
+	int err;
+
+	err = -EIO;
+	hpfs_lock(i->i_sb);
+	if (!(fnode = hpfs_map_fnode(i->i_sb, i->i_ino, &bh)))
+		goto fail;
+	err = hpfs_read_ea(i->i_sb, fnode, "SYMLINK", link, PAGE_SIZE);
+	brelse(bh);
+fail:
+	hpfs_unlock(i->i_sb);
+	folio_end_read(folio, err == 0);
+	return err;
+}
+
+const struct address_space_operations hpfs_symlink_aops = {
+	.read_folio	= hpfs_symlink_read_folio
+};
+
+static int hpfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
+		       struct dentry *old_dentry, struct inode *new_dir,
+		       struct dentry *new_dentry, unsigned int flags)
+{
+	const unsigned char *old_name = old_dentry->d_name.name;
+	unsigned old_len = old_dentry->d_name.len;
+	const unsigned char *new_name = new_dentry->d_name.name;
+	unsigned new_len = new_dentry->d_name.len;
+	struct inode *i = d_inode(old_dentry);
+	struct inode *new_inode = d_inode(new_dentry);
+	struct quad_buffer_head qbh, qbh1;
+	struct hpfs_dirent *dep, *nde;
+	struct hpfs_dirent de;
+	dnode_secno dno;
+	int r;
+	struct buffer_head *bh;
+	struct fnode *fnode;
+	int err;
+
+	if (flags & ~RENAME_NOREPLACE)
+		return -EINVAL;
+
+	if ((err = hpfs_chk_name(new_name, &new_len))) return err;
+	err = 0;
+	hpfs_adjust_length(old_name, &old_len);
+
+	hpfs_lock(i->i_sb);
+	/* order doesn't matter, due to VFS exclusion */
+	
+	/* Erm? Moving over the empty non-busy directory is perfectly legal */
+	if (new_inode && S_ISDIR(new_inode->i_mode)) {
+		err = -EINVAL;
+		goto end1;
+	}
+
+	if (!(dep = map_dirent(old_dir, hpfs_i(old_dir)->i_dno, old_name, old_len, &dno, &qbh))) {
+		hpfs_error(i->i_sb, "lookup succeeded but map dirent failed");
+		err = -ENOENT;
+		goto end1;
+	}
+	copy_de(&de, dep);
+	de.hidden = new_name[0] == '.';
+
+	if (new_inode) {
+		int r;
+		if ((r = hpfs_remove_dirent(old_dir, dno, dep, &qbh, 1)) != 2) {
+			if ((nde = map_dirent(new_dir, hpfs_i(new_dir)->i_dno, new_name, new_len, NULL, &qbh1))) {
+				clear_nlink(new_inode);
+				copy_de(nde, &de);
+				memcpy(nde->name, new_name, new_len);
+				hpfs_mark_4buffers_dirty(&qbh1);
+				hpfs_brelse4(&qbh1);
+				goto end;
+			}
+			hpfs_error(new_dir->i_sb, "hpfs_rename: could not find dirent");
+			err = -EFSERROR;
+			goto end1;
+		}
+		err = -ENOSPC;
+		goto end1;
+	}
+
+	if (new_dir == old_dir) hpfs_brelse4(&qbh);
+
+	if ((r = hpfs_add_dirent(new_dir, new_name, new_len, &de))) {
+		if (r == -1) hpfs_error(new_dir->i_sb, "hpfs_rename: dirent already exists!");
+		err = r == 1 ? -ENOSPC : -EFSERROR;
+		if (new_dir != old_dir) hpfs_brelse4(&qbh);
+		goto end1;
+	}
+	
+	if (new_dir == old_dir)
+		if (!(dep = map_dirent(old_dir, hpfs_i(old_dir)->i_dno, old_name, old_len, &dno, &qbh))) {
+			hpfs_error(i->i_sb, "lookup succeeded but map dirent failed at #2");
+			err = -ENOENT;
+			goto end1;
+		}
+
+	if ((r = hpfs_remove_dirent(old_dir, dno, dep, &qbh, 0))) {
+		hpfs_error(i->i_sb, "hpfs_rename: could not remove dirent");
+		err = r == 2 ? -ENOSPC : -EFSERROR;
+		goto end1;
+	}
+
+end:
+	hpfs_i(i)->i_parent_dir = new_dir->i_ino;
+	if (S_ISDIR(i->i_mode)) {
+		inc_nlink(new_dir);
+		drop_nlink(old_dir);
+	}
+	if ((fnode = hpfs_map_fnode(i->i_sb, i->i_ino, &bh))) {
+		fnode->up = cpu_to_le32(new_dir->i_ino);
+		fnode->len = new_len;
+		memcpy(fnode->name, new_name, new_len>15?15:new_len);
+		if (new_len < 15) memset(&fnode->name[new_len], 0, 15 - new_len);
+		mark_buffer_dirty(bh);
+		brelse(bh);
+	}
+end1:
+	if (!err) {
+		hpfs_update_directory_times(old_dir);
+		hpfs_update_directory_times(new_dir);
+	}
+	hpfs_unlock(i->i_sb);
+	return err;
+}
+
+const struct inode_operations hpfs_dir_iops =
+{
+	.create		= hpfs_create,
+	.lookup		= hpfs_lookup,
+	.unlink		= hpfs_unlink,
+	.symlink	= hpfs_symlink,
+	.mkdir		= hpfs_mkdir,
+	.rmdir		= hpfs_rmdir,
+	.mknod		= hpfs_mknod,
+	.rename		= hpfs_rename,
+	.setattr	= hpfs_setattr,
+};
diff --git a/fs/hpfs/super.c b/fs/hpfs/super.c
new file mode 100644
index 000000000..8fbdbf080
--- /dev/null
+++ b/fs/hpfs/super.c
@@ -0,0 +1,789 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/fs/hpfs/super.c
+ *
+ *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
+ *
+ *  mounting, unmounting, error handling
+ */
+
+#include "hpfs_fn.h"
+#include <linux/module.h>
+#include <linux/fs_struct.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
+#include <linux/init.h>
+#include <linux/statfs.h>
+#include <linux/magic.h>
+#include <linux/sched.h>
+#include <linux/bitmap.h>
+#include <linux/slab.h>
+#include <linux/seq_file.h>
+
+/* Mark the filesystem dirty, so that chkdsk checks it when os/2 booted */
+
+static void mark_dirty(struct super_block *s, int remount)
+{
+	if (hpfs_sb(s)->sb_chkdsk && (remount || !sb_rdonly(s))) {
+		struct buffer_head *bh;
+		struct hpfs_spare_block *sb;
+		if ((sb = hpfs_map_sector(s, 17, &bh, 0))) {
+			sb->dirty = 1;
+			sb->old_wrote = 0;
+			mark_buffer_dirty(bh);
+			sync_dirty_buffer(bh);
+			brelse(bh);
+		}
+	}
+}
+
+/* Mark the filesystem clean (mark it dirty for chkdsk if chkdsk==2 or if there
+   were errors) */
+
+static void unmark_dirty(struct super_block *s)
+{
+	struct buffer_head *bh;
+	struct hpfs_spare_block *sb;
+	if (sb_rdonly(s)) return;
+	sync_blockdev(s->s_bdev);
+	if ((sb = hpfs_map_sector(s, 17, &bh, 0))) {
+		sb->dirty = hpfs_sb(s)->sb_chkdsk > 1 - hpfs_sb(s)->sb_was_error;
+		sb->old_wrote = hpfs_sb(s)->sb_chkdsk >= 2 && !hpfs_sb(s)->sb_was_error;
+		mark_buffer_dirty(bh);
+		sync_dirty_buffer(bh);
+		brelse(bh);
+	}
+}
+
+/* Filesystem error... */
+void hpfs_error(struct super_block *s, const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	pr_err("filesystem error: %pV", &vaf);
+
+	va_end(args);
+
+	if (!hpfs_sb(s)->sb_was_error) {
+		if (hpfs_sb(s)->sb_err == 2) {
+			pr_cont("; crashing the system because you wanted it\n");
+			mark_dirty(s, 0);
+			panic("HPFS panic");
+		} else if (hpfs_sb(s)->sb_err == 1) {
+			if (sb_rdonly(s))
+				pr_cont("; already mounted read-only\n");
+			else {
+				pr_cont("; remounting read-only\n");
+				mark_dirty(s, 0);
+				s->s_flags |= SB_RDONLY;
+			}
+		} else if (sb_rdonly(s))
+				pr_cont("; going on - but anything won't be destroyed because it's read-only\n");
+		else
+			pr_cont("; corrupted filesystem mounted read/write - your computer will explode within 20 seconds ... but you wanted it so!\n");
+	} else
+		pr_cont("\n");
+	hpfs_sb(s)->sb_was_error = 1;
+}
+
+/*
+ * A little trick to detect cycles in many hpfs structures and don't let the
+ * kernel crash on corrupted filesystem. When first called, set c2 to 0.
+ *
+ * BTW. chkdsk doesn't detect cycles correctly. When I had 2 lost directories
+ * nested each in other, chkdsk locked up happilly.
+ */
+
+int hpfs_stop_cycles(struct super_block *s, int key, int *c1, int *c2,
+		char *msg)
+{
+	if (*c2 && *c1 == key) {
+		hpfs_error(s, "cycle detected on key %08x in %s", key, msg);
+		return 1;
+	}
+	(*c2)++;
+	if (!((*c2 - 1) & *c2)) *c1 = key;
+	return 0;
+}
+
+static void free_sbi(struct hpfs_sb_info *sbi)
+{
+	kfree(sbi->sb_cp_table);
+	kfree(sbi->sb_bmp_dir);
+	kfree(sbi);
+}
+
+static void lazy_free_sbi(struct rcu_head *rcu)
+{
+	free_sbi(container_of(rcu, struct hpfs_sb_info, rcu));
+}
+
+static void hpfs_put_super(struct super_block *s)
+{
+	hpfs_lock(s);
+	unmark_dirty(s);
+	hpfs_unlock(s);
+	call_rcu(&hpfs_sb(s)->rcu, lazy_free_sbi);
+}
+
+static unsigned hpfs_count_one_bitmap(struct super_block *s, secno secno)
+{
+	struct quad_buffer_head qbh;
+	unsigned long *bits;
+	unsigned count;
+
+	bits = hpfs_map_4sectors(s, secno, &qbh, 0);
+	if (!bits)
+		return (unsigned)-1;
+	count = bitmap_weight(bits, 2048 * BITS_PER_BYTE);
+	hpfs_brelse4(&qbh);
+	return count;
+}
+
+static unsigned count_bitmaps(struct super_block *s)
+{
+	unsigned n, count, n_bands;
+	n_bands = (hpfs_sb(s)->sb_fs_size + 0x3fff) >> 14;
+	count = 0;
+	for (n = 0; n < COUNT_RD_AHEAD; n++) {
+		hpfs_prefetch_bitmap(s, n);
+	}
+	for (n = 0; n < n_bands; n++) {
+		unsigned c;
+		hpfs_prefetch_bitmap(s, n + COUNT_RD_AHEAD);
+		c = hpfs_count_one_bitmap(s, le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[n]));
+		if (c != (unsigned)-1)
+			count += c;
+	}
+	return count;
+}
+
+unsigned hpfs_get_free_dnodes(struct super_block *s)
+{
+	struct hpfs_sb_info *sbi = hpfs_sb(s);
+	if (sbi->sb_n_free_dnodes == (unsigned)-1) {
+		unsigned c = hpfs_count_one_bitmap(s, sbi->sb_dmap);
+		if (c == (unsigned)-1)
+			return 0;
+		sbi->sb_n_free_dnodes = c;
+	}
+	return sbi->sb_n_free_dnodes;
+}
+
+static int hpfs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	struct super_block *s = dentry->d_sb;
+	struct hpfs_sb_info *sbi = hpfs_sb(s);
+	u64 id = huge_encode_dev(s->s_bdev->bd_dev);
+
+	hpfs_lock(s);
+
+	if (sbi->sb_n_free == (unsigned)-1)
+		sbi->sb_n_free = count_bitmaps(s);
+
+	buf->f_type = s->s_magic;
+	buf->f_bsize = 512;
+	buf->f_blocks = sbi->sb_fs_size;
+	buf->f_bfree = sbi->sb_n_free;
+	buf->f_bavail = sbi->sb_n_free;
+	buf->f_files = sbi->sb_dirband_size / 4;
+	buf->f_ffree = hpfs_get_free_dnodes(s);
+	buf->f_fsid = u64_to_fsid(id);
+	buf->f_namelen = 254;
+
+	hpfs_unlock(s);
+
+	return 0;
+}
+
+
+long hpfs_ioctl(struct file *file, unsigned cmd, unsigned long arg)
+{
+	switch (cmd) {
+		case FITRIM: {
+			struct fstrim_range range;
+			secno n_trimmed;
+			int r;
+			if (!capable(CAP_SYS_ADMIN))
+				return -EPERM;
+			if (copy_from_user(&range, (struct fstrim_range __user *)arg, sizeof(range)))
+				return -EFAULT;
+			r = hpfs_trim_fs(file_inode(file)->i_sb, range.start >> 9, (range.start + range.len) >> 9, (range.minlen + 511) >> 9, &n_trimmed);
+			if (r)
+				return r;
+			range.len = (u64)n_trimmed << 9;
+			if (copy_to_user((struct fstrim_range __user *)arg, &range, sizeof(range)))
+				return -EFAULT;
+			return 0;
+		}
+		default: {
+			return -ENOIOCTLCMD;
+		}
+	}
+}
+
+
+static struct kmem_cache * hpfs_inode_cachep;
+
+static struct inode *hpfs_alloc_inode(struct super_block *sb)
+{
+	struct hpfs_inode_info *ei;
+	ei = alloc_inode_sb(sb, hpfs_inode_cachep, GFP_NOFS);
+	if (!ei)
+		return NULL;
+	return &ei->vfs_inode;
+}
+
+static void hpfs_free_inode(struct inode *inode)
+{
+	kmem_cache_free(hpfs_inode_cachep, hpfs_i(inode));
+}
+
+static void init_once(void *foo)
+{
+	struct hpfs_inode_info *ei = (struct hpfs_inode_info *) foo;
+
+	inode_init_once(&ei->vfs_inode);
+}
+
+static int init_inodecache(void)
+{
+	hpfs_inode_cachep = kmem_cache_create("hpfs_inode_cache",
+					     sizeof(struct hpfs_inode_info),
+					     0, (SLAB_RECLAIM_ACCOUNT|
+						SLAB_ACCOUNT),
+					     init_once);
+	if (hpfs_inode_cachep == NULL)
+		return -ENOMEM;
+	return 0;
+}
+
+static void destroy_inodecache(void)
+{
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
+	kmem_cache_destroy(hpfs_inode_cachep);
+}
+
+enum {
+	Opt_help, Opt_uid, Opt_gid, Opt_umask, Opt_case,
+	Opt_check, Opt_err, Opt_eas, Opt_chkdsk, Opt_timeshift,
+};
+
+static const struct constant_table hpfs_param_case[] = {
+	{"asis",	0},
+	{"lower",	1},
+	{}
+};
+
+static const struct constant_table hpfs_param_check[] = {
+	{"none",	0},
+	{"normal",	1},
+	{"strict",	2},
+	{}
+};
+
+static const struct constant_table hpfs_param_err[] = {
+	{"continue",	0},
+	{"remount-ro",	1},
+	{"panic",	2},
+	{}
+};
+
+static const struct constant_table hpfs_param_eas[] = {
+	{"no",		0},
+	{"ro",		1},
+	{"rw",		2},
+	{}
+};
+
+static const struct constant_table hpfs_param_chkdsk[] = {
+	{"no",		0},
+	{"errors",	1},
+	{"always",	2},
+	{}
+};
+
+static const struct fs_parameter_spec hpfs_param_spec[] = {
+	fsparam_flag	("help",	Opt_help),
+	fsparam_uid	("uid",		Opt_uid),
+	fsparam_gid	("gid",		Opt_gid),
+	fsparam_u32oct	("umask",	Opt_umask),
+	fsparam_enum	("case",	Opt_case,	hpfs_param_case),
+	fsparam_enum	("check",	Opt_check,	hpfs_param_check),
+	fsparam_enum	("errors",	Opt_err,	hpfs_param_err),
+	fsparam_enum	("eas",		Opt_eas,	hpfs_param_eas),
+	fsparam_enum	("chkdsk",	Opt_chkdsk,	hpfs_param_chkdsk),
+	fsparam_s32	("timeshift",	Opt_timeshift),
+	{}
+};
+
+struct hpfs_fc_context {
+	kuid_t uid;
+	kgid_t gid;
+	umode_t umask;
+	int lowercase;
+	int eas;
+	int chk;
+	int errs;
+	int chkdsk;
+	int timeshift;
+};
+
+static inline void hpfs_help(void)
+{
+	pr_info("\n\
+HPFS filesystem options:\n\
+      help              do not mount and display this text\n\
+      uid=xxx           set uid of files that don't have uid specified in eas\n\
+      gid=xxx           set gid of files that don't have gid specified in eas\n\
+      umask=xxx         set mode of files that don't have mode specified in eas\n\
+      case=lower        lowercase all files\n\
+      case=asis         do not lowercase files (default)\n\
+      check=none        no fs checks - kernel may crash on corrupted filesystem\n\
+      check=normal      do some checks - it should not crash (default)\n\
+      check=strict      do extra time-consuming checks, used for debugging\n\
+      errors=continue   continue on errors\n\
+      errors=remount-ro remount read-only if errors found (default)\n\
+      errors=panic      panic on errors\n\
+      chkdsk=no         do not mark fs for chkdsking even if there were errors\n\
+      chkdsk=errors     mark fs dirty if errors found (default)\n\
+      chkdsk=always     always mark fs dirty - used for debugging\n\
+      eas=no            ignore extended attributes\n\
+      eas=ro            read but do not write extended attributes\n\
+      eas=rw            r/w eas => enables chmod, chown, mknod, ln -s (default)\n\
+      timeshift=nnn	add nnn seconds to file times\n\
+\n");
+}
+
+static int hpfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+	struct hpfs_fc_context *ctx = fc->fs_private;
+	struct fs_parse_result result;
+	int opt;
+
+	opt = fs_parse(fc, hpfs_param_spec, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case Opt_help:
+		hpfs_help();
+		return -EINVAL;
+	case Opt_uid:
+		ctx->uid = result.uid;
+		break;
+	case Opt_gid:
+		ctx->gid = result.gid;
+		break;
+	case Opt_umask:
+		ctx->umask = result.uint_32;
+		break;
+	case Opt_case:
+		ctx->lowercase = result.uint_32;
+		break;
+	case Opt_check:
+		ctx->chk = result.uint_32;
+		break;
+	case Opt_err:
+		ctx->errs = result.uint_32;
+		break;
+	case Opt_eas:
+		ctx->eas = result.uint_32;
+		break;
+	case Opt_chkdsk:
+		ctx->chkdsk = result.uint_32;
+		break;
+	case Opt_timeshift:
+		{
+			char *rhs = param->string;
+			int timeshift;
+
+			if (kstrtoint(rhs, 0, &timeshift))
+				return -EINVAL;
+			ctx->timeshift = timeshift;
+			break;
+		}
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int hpfs_reconfigure(struct fs_context *fc)
+{
+	struct hpfs_fc_context *ctx = fc->fs_private;
+	struct super_block *s = fc->root->d_sb;
+	struct hpfs_sb_info *sbi = hpfs_sb(s);
+
+	sync_filesystem(s);
+
+	fc->sb_flags |= SB_NOATIME;
+
+	hpfs_lock(s);
+
+	if (ctx->timeshift != sbi->sb_timeshift) {
+		pr_err("timeshift can't be changed using remount.\n");
+		goto out_err;
+	}
+
+	unmark_dirty(s);
+
+	sbi->sb_uid = ctx->uid; sbi->sb_gid = ctx->gid;
+	sbi->sb_mode = 0777 & ~ctx->umask;
+	sbi->sb_lowercase = ctx->lowercase;
+	sbi->sb_eas = ctx->eas; sbi->sb_chk = ctx->chk;
+	sbi->sb_chkdsk = ctx->chkdsk;
+	sbi->sb_err = ctx->errs; sbi->sb_timeshift = ctx->timeshift;
+
+	if (!(fc->sb_flags & SB_RDONLY)) mark_dirty(s, 1);
+
+	hpfs_unlock(s);
+	return 0;
+
+out_err:
+	hpfs_unlock(s);
+	return -EINVAL;
+}
+
+static int hpfs_show_options(struct seq_file *seq, struct dentry *root)
+{
+	struct hpfs_sb_info *sbi = hpfs_sb(root->d_sb);
+
+	seq_printf(seq, ",uid=%u", from_kuid_munged(&init_user_ns, sbi->sb_uid));
+	seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, sbi->sb_gid));
+	seq_printf(seq, ",umask=%03o", (~sbi->sb_mode & 0777));
+	if (sbi->sb_lowercase)
+		seq_printf(seq, ",case=lower");
+	if (!sbi->sb_chk)
+		seq_printf(seq, ",check=none");
+	if (sbi->sb_chk == 2)
+		seq_printf(seq, ",check=strict");
+	if (!sbi->sb_err)
+		seq_printf(seq, ",errors=continue");
+	if (sbi->sb_err == 2)
+		seq_printf(seq, ",errors=panic");
+	if (!sbi->sb_chkdsk)
+		seq_printf(seq, ",chkdsk=no");
+	if (sbi->sb_chkdsk == 2)
+		seq_printf(seq, ",chkdsk=always");
+	if (!sbi->sb_eas)
+		seq_printf(seq, ",eas=no");
+	if (sbi->sb_eas == 1)
+		seq_printf(seq, ",eas=ro");
+	if (sbi->sb_timeshift)
+		seq_printf(seq, ",timeshift=%d", sbi->sb_timeshift);
+	return 0;
+}
+
+/* Super operations */
+
+static const struct super_operations hpfs_sops =
+{
+	.alloc_inode	= hpfs_alloc_inode,
+	.free_inode	= hpfs_free_inode,
+	.evict_inode	= hpfs_evict_inode,
+	.put_super	= hpfs_put_super,
+	.statfs		= hpfs_statfs,
+	.show_options	= hpfs_show_options,
+};
+
+static int hpfs_fill_super(struct super_block *s, struct fs_context *fc)
+{
+	struct hpfs_fc_context *ctx = fc->fs_private;
+	struct buffer_head *bh0, *bh1, *bh2;
+	struct hpfs_boot_block *bootblock;
+	struct hpfs_super_block *superblock;
+	struct hpfs_spare_block *spareblock;
+	struct hpfs_sb_info *sbi;
+	struct inode *root;
+	int silent = fc->sb_flags & SB_SILENT;
+
+	dnode_secno root_dno;
+	struct hpfs_dirent *de = NULL;
+	struct quad_buffer_head qbh;
+
+	sbi = kzalloc_obj(*sbi);
+	if (!sbi) {
+		return -ENOMEM;
+	}
+	s->s_fs_info = sbi;
+
+	mutex_init(&sbi->hpfs_mutex);
+	hpfs_lock(s);
+
+	/*sbi->sb_mounting = 1;*/
+	if (!sb_set_blocksize(s, 512))
+		goto bail0;
+	sbi->sb_fs_size = -1;
+	if (!(bootblock = hpfs_map_sector(s, 0, &bh0, 0))) goto bail1;
+	if (!(superblock = hpfs_map_sector(s, 16, &bh1, 1))) goto bail2;
+	if (!(spareblock = hpfs_map_sector(s, 17, &bh2, 0))) goto bail3;
+
+	/* Check magics */
+	if (/*le16_to_cpu(bootblock->magic) != BB_MAGIC
+	    ||*/ le32_to_cpu(superblock->magic) != SB_MAGIC
+	    || le32_to_cpu(spareblock->magic) != SP_MAGIC) {
+		if (!silent)
+			pr_err("Bad magic ... probably not HPFS\n");
+		goto bail4;
+	}
+
+	/* Check version */
+	if (!sb_rdonly(s) && superblock->funcversion != 2 && superblock->funcversion != 3) {
+		pr_err("Bad version %d,%d. Mount readonly to go around\n",
+			(int)superblock->version, (int)superblock->funcversion);
+		pr_err("please try recent version of HPFS driver at http://artax.karlin.mff.cuni.cz/~mikulas/vyplody/hpfs/index-e.cgi and if it still can't understand this format, contact author - mikulas@artax.karlin.mff.cuni.cz\n");
+		goto bail4;
+	}
+
+	s->s_flags |= SB_NOATIME;
+
+	/* Fill superblock stuff */
+	s->s_magic = HPFS_SUPER_MAGIC;
+	s->s_op = &hpfs_sops;
+	set_default_d_op(s, &hpfs_dentry_operations);
+	s->s_time_min =  local_to_gmt(s, 0);
+	s->s_time_max =  local_to_gmt(s, U32_MAX);
+
+	sbi->sb_root = le32_to_cpu(superblock->root);
+	sbi->sb_fs_size = le32_to_cpu(superblock->n_sectors);
+	sbi->sb_bitmaps = le32_to_cpu(superblock->bitmaps);
+	sbi->sb_dirband_start = le32_to_cpu(superblock->dir_band_start);
+	sbi->sb_dirband_size = le32_to_cpu(superblock->n_dir_band);
+	sbi->sb_dmap = le32_to_cpu(superblock->dir_band_bitmap);
+	sbi->sb_uid = ctx->uid;
+	sbi->sb_gid = ctx->gid;
+	sbi->sb_mode = 0777 & ~ctx->umask;
+	sbi->sb_n_free = -1;
+	sbi->sb_n_free_dnodes = -1;
+	sbi->sb_lowercase = ctx->lowercase;
+	sbi->sb_eas = ctx->eas;
+	sbi->sb_chk = ctx->chk;
+	sbi->sb_chkdsk = ctx->chkdsk;
+	sbi->sb_err = ctx->errs;
+	sbi->sb_timeshift = ctx->timeshift;
+	sbi->sb_was_error = 0;
+	sbi->sb_cp_table = NULL;
+	sbi->sb_c_bitmap = -1;
+	sbi->sb_max_fwd_alloc = 0xffffff;
+
+	if (sbi->sb_fs_size >= 0x80000000) {
+		hpfs_error(s, "invalid size in superblock: %08x",
+			(unsigned)sbi->sb_fs_size);
+		goto bail4;
+	}
+
+	if (spareblock->n_spares_used)
+		hpfs_load_hotfix_map(s, spareblock);
+
+	/* Load bitmap directory */
+	if (!(sbi->sb_bmp_dir = hpfs_load_bitmap_directory(s, le32_to_cpu(superblock->bitmaps))))
+		goto bail4;
+	
+	/* Check for general fs errors*/
+	if (spareblock->dirty && !spareblock->old_wrote) {
+		if (sbi->sb_err == 2) {
+			pr_err("Improperly stopped, not mounted\n");
+			goto bail4;
+		}
+		hpfs_error(s, "improperly stopped");
+	}
+
+	if (!sb_rdonly(s)) {
+		spareblock->dirty = 1;
+		spareblock->old_wrote = 0;
+		mark_buffer_dirty(bh2);
+	}
+
+	if (le32_to_cpu(spareblock->n_dnode_spares) != le32_to_cpu(spareblock->n_dnode_spares_free)) {
+		if (sbi->sb_err >= 2) {
+			pr_err("Spare dnodes used, try chkdsk\n");
+			mark_dirty(s, 0);
+			goto bail4;
+		}
+		hpfs_error(s, "warning: spare dnodes used, try chkdsk");
+		if (sbi->sb_err == 0)
+			pr_err("Proceeding, but your filesystem could be corrupted if you delete files or directories\n");
+	}
+	if (sbi->sb_chk) {
+		unsigned a;
+		if (le32_to_cpu(superblock->dir_band_end) - le32_to_cpu(superblock->dir_band_start) + 1 != le32_to_cpu(superblock->n_dir_band) ||
+		    le32_to_cpu(superblock->dir_band_end) < le32_to_cpu(superblock->dir_band_start) || le32_to_cpu(superblock->n_dir_band) > 0x4000) {
+			hpfs_error(s, "dir band size mismatch: dir_band_start==%08x, dir_band_end==%08x, n_dir_band==%08x",
+				le32_to_cpu(superblock->dir_band_start), le32_to_cpu(superblock->dir_band_end), le32_to_cpu(superblock->n_dir_band));
+			goto bail4;
+		}
+		a = sbi->sb_dirband_size;
+		sbi->sb_dirband_size = 0;
+		if (hpfs_chk_sectors(s, le32_to_cpu(superblock->dir_band_start), le32_to_cpu(superblock->n_dir_band), "dir_band") ||
+		    hpfs_chk_sectors(s, le32_to_cpu(superblock->dir_band_bitmap), 4, "dir_band_bitmap") ||
+		    hpfs_chk_sectors(s, le32_to_cpu(superblock->bitmaps), 4, "bitmaps")) {
+			mark_dirty(s, 0);
+			goto bail4;
+		}
+		sbi->sb_dirband_size = a;
+	} else
+		pr_err("You really don't want any checks? You are crazy...\n");
+
+	/* Load code page table */
+	if (le32_to_cpu(spareblock->n_code_pages))
+		if (!(sbi->sb_cp_table = hpfs_load_code_page(s, le32_to_cpu(spareblock->code_page_dir))))
+			pr_err("code page support is disabled\n");
+
+	brelse(bh2);
+	brelse(bh1);
+	brelse(bh0);
+
+	root = iget_locked(s, sbi->sb_root);
+	if (!root)
+		goto bail0;
+	hpfs_init_inode(root);
+	hpfs_read_inode(root);
+	unlock_new_inode(root);
+	s->s_root = d_make_root(root);
+	if (!s->s_root)
+		goto bail0;
+
+	/*
+	 * find the root directory's . pointer & finish filling in the inode
+	 */
+
+	root_dno = hpfs_fnode_dno(s, sbi->sb_root);
+	if (root_dno)
+		de = map_dirent(root, root_dno, "\001\001", 2, NULL, &qbh);
+	if (!de)
+		hpfs_error(s, "unable to find root dir");
+	else {
+		inode_set_atime(root,
+				local_to_gmt(s, le32_to_cpu(de->read_date)),
+				0);
+		inode_set_mtime(root,
+				local_to_gmt(s, le32_to_cpu(de->write_date)),
+				0);
+		inode_set_ctime(root,
+				local_to_gmt(s, le32_to_cpu(de->creation_date)),
+				0);
+		hpfs_i(root)->i_ea_size = le32_to_cpu(de->ea_size);
+		hpfs_i(root)->i_parent_dir = root->i_ino;
+		if (root->i_size == -1)
+			root->i_size = 2048;
+		if (root->i_blocks == -1)
+			root->i_blocks = 5;
+		hpfs_brelse4(&qbh);
+	}
+	hpfs_unlock(s);
+	return 0;
+
+bail4:	brelse(bh2);
+bail3:	brelse(bh1);
+bail2:	brelse(bh0);
+bail1:
+bail0:
+	hpfs_unlock(s);
+	free_sbi(sbi);
+	return -EINVAL;
+}
+
+static int hpfs_get_tree(struct fs_context *fc)
+{
+	return get_tree_bdev(fc, hpfs_fill_super);
+}
+
+static void hpfs_free_fc(struct fs_context *fc)
+{
+	kfree(fc->fs_private);
+}
+
+static const struct fs_context_operations hpfs_fc_context_ops = {
+	.parse_param	= hpfs_parse_param,
+	.get_tree	= hpfs_get_tree,
+	.reconfigure	= hpfs_reconfigure,
+	.free		= hpfs_free_fc,
+};
+
+static int hpfs_init_fs_context(struct fs_context *fc)
+{
+	struct hpfs_fc_context *ctx;
+
+	ctx = kzalloc_obj(struct hpfs_fc_context);
+	if (!ctx)
+		return -ENOMEM;
+
+	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
+		struct super_block *sb = fc->root->d_sb;
+		struct hpfs_sb_info *sbi = hpfs_sb(sb);
+
+		ctx->uid = sbi->sb_uid;
+		ctx->gid = sbi->sb_gid;
+		ctx->umask = 0777 & ~sbi->sb_mode;
+		ctx->lowercase = sbi->sb_lowercase;
+		ctx->eas = sbi->sb_eas;
+		ctx->chk = sbi->sb_chk;
+		ctx->chkdsk = sbi->sb_chkdsk;
+		ctx->errs = sbi->sb_err;
+		ctx->timeshift = sbi->sb_timeshift;
+
+	} else {
+		ctx->uid = current_uid();
+		ctx->gid = current_gid();
+		ctx->umask = current_umask();
+		ctx->lowercase = 0;
+		ctx->eas = 2;
+		ctx->chk = 1;
+		ctx->errs = 1;
+		ctx->chkdsk = 1;
+		ctx->timeshift = 0;
+	}
+
+	fc->fs_private = ctx;
+	fc->ops = &hpfs_fc_context_ops;
+
+	return 0;
+};
+
+static struct file_system_type hpfs_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "hpfs",
+	.kill_sb	= kill_block_super,
+	.fs_flags	= FS_REQUIRES_DEV,
+	.init_fs_context = hpfs_init_fs_context,
+	.parameters	= hpfs_param_spec,
+};
+MODULE_ALIAS_FS("hpfs");
+
+static int __init init_hpfs_fs(void)
+{
+	int err = init_inodecache();
+	if (err)
+		goto out1;
+	err = register_filesystem(&hpfs_fs_type);
+	if (err)
+		goto out;
+	return 0;
+out:
+	destroy_inodecache();
+out1:
+	return err;
+}
+
+static void __exit exit_hpfs_fs(void)
+{
+	unregister_filesystem(&hpfs_fs_type);
+	destroy_inodecache();
+}
+
+module_init(init_hpfs_fs)
+module_exit(exit_hpfs_fs)
+MODULE_DESCRIPTION("OS/2 HPFS file system support");
+MODULE_LICENSE("GPL");