x86/kprobes: Fix crash when probing CS CALL instructionsgrafted

When using eBPF to probe CS CALL instructions within a function,
a crash can be triggered.

The eBPF tool probes offset 257 of the __hrtimer_run_queues()
function:

<__hrtimer_run_queues+249>:  nopl   0x0(%rax,%rax,1)
<__hrtimer_run_queues+254>:  mov    %r14,%rdi
<__hrtimer_run_queues+257>:  cs call <__x86_indirect_thunk_r12>
<__hrtimer_run_queues+263>:  mov    %eax,%r12d
<__hrtimer_run_queues+266>:  xchg   %ax,%ax
<__hrtimer_run_queues+268>:  mov    %r13,%rdi

Which triggers this crash:

  BUG: unable to handle page fault for address: 00000000000f41c9
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 0 P4D 0
  Oops: 0002 [#1] SMP NOPTI
  CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P
  RIP: 0010:__hrtimer_run_queues+0x106/0x230

Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is
at the 6th byte of the above CS CALL instruction. Since the CS CALL
instruction occupies 6 bytes, the exception occurred in the middle of that
call instruction.

The root cause is that when using eBPF tools to probe in the middle of a
function, a kprobe with INT3 is used as the underlying implementation.

During single-step emulation of the original CALL instruction,
int3_emulate_call() assumes that the probed CALL instruction is 5 bytes
long. However, the actual CS-prefixed CALL instruction occupies 6 bytes,
so it constructs an incorrect exception return address. When the CPU
returns from the kprobe handler, the next instruction to be executed is at
the address of the last byte of that CS CALL instruction. Coincidentally,
starting from that address, the CPU fetches and decodes a completely
different instruction, which ultimately triggers a kernel crash.

Fix the issue by using the actual instruction length obtained from
the instruction decoder when constructing the exception return
address, rather than relying on the hardcoded CALL_INSN_SIZE macro.

[ mingo: Refined the changelog ]

Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Jinke Han <jinkehan@didiglobal.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000

1 files changed, 752 insertions, 0 deletions

diff --git a/fs/hfs/inode.c b/fs/hfs/inode.c
new file mode 100644
index 000000000..2aef3c36a
--- /dev/null
+++ b/fs/hfs/inode.c
@@ -0,0 +1,752 @@
+/*
+ *  linux/fs/hfs/inode.c
+ *
+ * Copyright (C) 1995-1997  Paul H. Hargrove
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ * This file may be distributed under the terms of the GNU General Public License.
+ *
+ * This file contains inode-related functions which do not depend on
+ * which scheme is being used to represent forks.
+ *
+ * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
+ */
+
+#include <linux/pagemap.h>
+#include <linux/mpage.h>
+#include <linux/sched.h>
+#include <linux/cred.h>
+#include <linux/uio.h>
+#include <linux/xattr.h>
+#include <linux/blkdev.h>
+#include <linux/fileattr.h>
+
+#include "hfs_fs.h"
+#include "btree.h"
+
+static const struct file_operations hfs_file_operations;
+static const struct inode_operations hfs_file_inode_operations;
+
+/*================ Variable-like macros ================*/
+
+#define HFS_VALID_MODE_BITS  (S_IFREG | S_IFDIR | S_IRWXUGO)
+
+static int hfs_read_folio(struct file *file, struct folio *folio)
+{
+	return block_read_full_folio(folio, hfs_get_block);
+}
+
+static void hfs_write_failed(struct address_space *mapping, loff_t to)
+{
+	struct inode *inode = mapping->host;
+
+	if (to > inode->i_size) {
+		truncate_pagecache(inode, inode->i_size);
+		hfs_file_truncate(inode);
+	}
+}
+
+int hfs_write_begin(const struct kiocb *iocb, struct address_space *mapping,
+		    loff_t pos, unsigned int len, struct folio **foliop,
+		    void **fsdata)
+{
+	struct inode *inode = mapping->host;
+	struct hfs_sb_info *sbi = HFS_SB(inode->i_sb);
+	loff_t total_capacity;
+	int ret;
+
+	total_capacity = (loff_t)sbi->fs_ablocks * sbi->alloc_blksz;
+
+	if (pos >= total_capacity)
+		return -EFBIG;
+
+	ret = cont_write_begin(iocb, mapping, pos, len, foliop, fsdata,
+				hfs_get_block,
+				&HFS_I(inode)->phys_size);
+	if (unlikely(ret))
+		hfs_write_failed(mapping, pos + len);
+
+	return ret;
+}
+
+static sector_t hfs_bmap(struct address_space *mapping, sector_t block)
+{
+	return generic_block_bmap(mapping, block, hfs_get_block);
+}
+
+static bool hfs_release_folio(struct folio *folio, gfp_t mask)
+{
+	struct inode *inode = folio->mapping->host;
+	struct super_block *sb = inode->i_sb;
+	struct hfs_btree *tree;
+	struct hfs_bnode *node;
+	u32 nidx;
+	int i;
+	bool res = true;
+
+	switch (inode->i_ino) {
+	case HFS_EXT_CNID:
+		tree = HFS_SB(sb)->ext_tree;
+		break;
+	case HFS_CAT_CNID:
+		tree = HFS_SB(sb)->cat_tree;
+		break;
+	default:
+		BUG();
+		return false;
+	}
+
+	if (!tree)
+		return false;
+
+	if (tree->node_size >= PAGE_SIZE) {
+		nidx = folio->index >> (tree->node_size_shift - PAGE_SHIFT);
+		spin_lock(&tree->hash_lock);
+		node = hfs_bnode_findhash(tree, nidx);
+		if (!node)
+			;
+		else if (atomic_read(&node->refcnt))
+			res = false;
+		if (res && node) {
+			hfs_bnode_unhash(node);
+			hfs_bnode_free(node);
+		}
+		spin_unlock(&tree->hash_lock);
+	} else {
+		nidx = folio->index << (PAGE_SHIFT - tree->node_size_shift);
+		i = 1 << (PAGE_SHIFT - tree->node_size_shift);
+		spin_lock(&tree->hash_lock);
+		do {
+			node = hfs_bnode_findhash(tree, nidx++);
+			if (!node)
+				continue;
+			if (atomic_read(&node->refcnt)) {
+				res = false;
+				break;
+			}
+			hfs_bnode_unhash(node);
+			hfs_bnode_free(node);
+		} while (--i && nidx < tree->node_count);
+		spin_unlock(&tree->hash_lock);
+	}
+	return res ? try_to_free_buffers(folio) : false;
+}
+
+static ssize_t hfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
+{
+	struct file *file = iocb->ki_filp;
+	struct address_space *mapping = file->f_mapping;
+	struct inode *inode = mapping->host;
+	size_t count = iov_iter_count(iter);
+	ssize_t ret;
+
+	ret = blockdev_direct_IO(iocb, inode, iter, hfs_get_block);
+
+	/*
+	 * In case of error extending write may have instantiated a few
+	 * blocks outside i_size. Trim these off again.
+	 */
+	if (unlikely(iov_iter_rw(iter) == WRITE && ret < 0)) {
+		loff_t isize = i_size_read(inode);
+		loff_t end = iocb->ki_pos + count;
+
+		if (end > isize)
+			hfs_write_failed(mapping, end);
+	}
+
+	return ret;
+}
+
+static int hfs_writepages(struct address_space *mapping,
+			  struct writeback_control *wbc)
+{
+	return mpage_writepages(mapping, wbc, hfs_get_block);
+}
+
+const struct address_space_operations hfs_btree_aops = {
+	.dirty_folio	= block_dirty_folio,
+	.invalidate_folio = block_invalidate_folio,
+	.read_folio	= hfs_read_folio,
+	.writepages	= hfs_writepages,
+	.write_begin	= hfs_write_begin,
+	.write_end	= generic_write_end,
+	.migrate_folio	= buffer_migrate_folio,
+	.bmap		= hfs_bmap,
+	.release_folio	= hfs_release_folio,
+};
+
+const struct address_space_operations hfs_aops = {
+	.dirty_folio	= block_dirty_folio,
+	.invalidate_folio = block_invalidate_folio,
+	.read_folio	= hfs_read_folio,
+	.write_begin	= hfs_write_begin,
+	.write_end	= generic_write_end,
+	.bmap		= hfs_bmap,
+	.direct_IO	= hfs_direct_IO,
+	.writepages	= hfs_writepages,
+	.migrate_folio	= buffer_migrate_folio,
+};
+
+/*
+ * hfs_new_inode
+ */
+struct inode *hfs_new_inode(struct inode *dir, const struct qstr *name, umode_t mode)
+{
+	struct super_block *sb = dir->i_sb;
+	struct inode *inode = new_inode(sb);
+	s64 next_id;
+	s64 file_count;
+	s64 folder_count;
+	int err = -ENOMEM;
+
+	if (!inode)
+		goto out_err;
+
+	err = -ERANGE;
+
+	mutex_init(&HFS_I(inode)->extents_lock);
+	hfs_cat_build_key(sb, (btree_key *)&HFS_I(inode)->cat_key, dir->i_ino, name);
+	next_id = atomic64_inc_return(&HFS_SB(sb)->next_id);
+	if (next_id > U32_MAX) {
+		atomic64_dec(&HFS_SB(sb)->next_id);
+		pr_err("cannot create new inode: next CNID exceeds limit\n");
+		goto out_discard;
+	}
+	inode->i_ino = (u32)next_id - 1;
+	inode->i_mode = mode;
+	inode->i_uid = current_fsuid();
+	inode->i_gid = current_fsgid();
+	set_nlink(inode, 1);
+	simple_inode_init_ts(inode);
+	HFS_I(inode)->flags = 0;
+	HFS_I(inode)->rsrc_inode = NULL;
+	HFS_I(inode)->fs_blocks = 0;
+	HFS_I(inode)->tz_secondswest = sys_tz.tz_minuteswest * 60;
+	if (S_ISDIR(mode)) {
+		inode->i_size = 2;
+		folder_count = atomic64_inc_return(&HFS_SB(sb)->folder_count);
+		if (folder_count> U32_MAX) {
+			atomic64_dec(&HFS_SB(sb)->folder_count);
+			pr_err("cannot create new inode: folder count exceeds limit\n");
+			goto out_discard;
+		}
+		if (dir->i_ino == HFS_ROOT_CNID)
+			HFS_SB(sb)->root_dirs++;
+		inode->i_op = &hfs_dir_inode_operations;
+		inode->i_fop = &hfs_dir_operations;
+		inode->i_mode |= S_IRWXUGO;
+		inode->i_mode &= ~HFS_SB(inode->i_sb)->s_dir_umask;
+	} else if (S_ISREG(mode)) {
+		HFS_I(inode)->clump_blocks = HFS_SB(sb)->clumpablks;
+		file_count = atomic64_inc_return(&HFS_SB(sb)->file_count);
+		if (file_count > U32_MAX) {
+			atomic64_dec(&HFS_SB(sb)->file_count);
+			pr_err("cannot create new inode: file count exceeds limit\n");
+			goto out_discard;
+		}
+		if (dir->i_ino == HFS_ROOT_CNID)
+			HFS_SB(sb)->root_files++;
+		inode->i_op = &hfs_file_inode_operations;
+		inode->i_fop = &hfs_file_operations;
+		inode->i_mapping->a_ops = &hfs_aops;
+		inode->i_mode |= S_IRUGO|S_IXUGO;
+		if (mode & S_IWUSR)
+			inode->i_mode |= S_IWUGO;
+		inode->i_mode &= ~HFS_SB(inode->i_sb)->s_file_umask;
+		HFS_I(inode)->phys_size = 0;
+		HFS_I(inode)->alloc_blocks = 0;
+		HFS_I(inode)->first_blocks = 0;
+		HFS_I(inode)->cached_start = 0;
+		HFS_I(inode)->cached_blocks = 0;
+		memset(HFS_I(inode)->first_extents, 0, sizeof(hfs_extent_rec));
+		memset(HFS_I(inode)->cached_extents, 0, sizeof(hfs_extent_rec));
+	}
+	insert_inode_hash(inode);
+	mark_inode_dirty(inode);
+	set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
+	hfs_mark_mdb_dirty(sb);
+
+	return inode;
+
+	out_discard:
+		iput(inode);
+	out_err:
+		return ERR_PTR(err);
+}
+
+void hfs_delete_inode(struct inode *inode)
+{
+	struct super_block *sb = inode->i_sb;
+
+	hfs_dbg("ino %llu\n", inode->i_ino);
+	if (S_ISDIR(inode->i_mode)) {
+		atomic64_dec(&HFS_SB(sb)->folder_count);
+		if (HFS_I(inode)->cat_key.ParID == cpu_to_be32(HFS_ROOT_CNID))
+			HFS_SB(sb)->root_dirs--;
+		set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
+		hfs_mark_mdb_dirty(sb);
+		return;
+	}
+
+	atomic64_dec(&HFS_SB(sb)->file_count);
+	if (HFS_I(inode)->cat_key.ParID == cpu_to_be32(HFS_ROOT_CNID))
+		HFS_SB(sb)->root_files--;
+	if (S_ISREG(inode->i_mode)) {
+		if (!inode->i_nlink) {
+			inode->i_size = 0;
+			hfs_file_truncate(inode);
+		}
+	}
+	set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
+	hfs_mark_mdb_dirty(sb);
+}
+
+void hfs_inode_read_fork(struct inode *inode, struct hfs_extent *ext,
+			 __be32 __log_size, __be32 phys_size, u32 clump_size)
+{
+	struct super_block *sb = inode->i_sb;
+	u32 log_size = be32_to_cpu(__log_size);
+	u16 count;
+	int i;
+
+	memcpy(HFS_I(inode)->first_extents, ext, sizeof(hfs_extent_rec));
+	for (count = 0, i = 0; i < 3; i++)
+		count += be16_to_cpu(ext[i].count);
+	HFS_I(inode)->first_blocks = count;
+	HFS_I(inode)->cached_start = 0;
+	HFS_I(inode)->cached_blocks = 0;
+
+	inode->i_size = HFS_I(inode)->phys_size = log_size;
+	HFS_I(inode)->fs_blocks = (log_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
+	inode_set_bytes(inode, HFS_I(inode)->fs_blocks << sb->s_blocksize_bits);
+	HFS_I(inode)->alloc_blocks = be32_to_cpu(phys_size) /
+				     HFS_SB(sb)->alloc_blksz;
+	HFS_I(inode)->clump_blocks = clump_size / HFS_SB(sb)->alloc_blksz;
+	if (!HFS_I(inode)->clump_blocks)
+		HFS_I(inode)->clump_blocks = HFS_SB(sb)->clumpablks;
+}
+
+struct hfs_iget_data {
+	struct hfs_cat_key *key;
+	hfs_cat_rec *rec;
+};
+
+static int hfs_test_inode(struct inode *inode, void *data)
+{
+	struct hfs_iget_data *idata = data;
+	hfs_cat_rec *rec;
+
+	rec = idata->rec;
+	switch (rec->type) {
+	case HFS_CDR_DIR:
+		return inode->i_ino == be32_to_cpu(rec->dir.DirID);
+	case HFS_CDR_FIL:
+		return inode->i_ino == be32_to_cpu(rec->file.FlNum);
+	default:
+		BUG();
+		return 1;
+	}
+}
+
+/*
+ * hfs_read_inode
+ */
+static int hfs_read_inode(struct inode *inode, void *data)
+{
+	struct hfs_iget_data *idata = data;
+	struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
+	hfs_cat_rec *rec;
+	struct timespec64 mtime;
+
+	HFS_I(inode)->flags = 0;
+	HFS_I(inode)->rsrc_inode = NULL;
+	mutex_init(&HFS_I(inode)->extents_lock);
+
+	/* Initialize the inode */
+	inode->i_uid = hsb->s_uid;
+	inode->i_gid = hsb->s_gid;
+	set_nlink(inode, 1);
+
+	if (idata->key)
+		HFS_I(inode)->cat_key = *idata->key;
+	else
+		HFS_I(inode)->flags |= HFS_FLG_RSRC;
+	HFS_I(inode)->tz_secondswest = sys_tz.tz_minuteswest * 60;
+
+	rec = idata->rec;
+	switch (rec->type) {
+	case HFS_CDR_FIL:
+		if (!hfs_is_valid_cnid(be32_to_cpu(rec->file.FlNum), rec->type))
+			return -EIO;
+
+		if (!HFS_IS_RSRC(inode)) {
+			hfs_inode_read_fork(inode, rec->file.ExtRec, rec->file.LgLen,
+					    rec->file.PyLen, be16_to_cpu(rec->file.ClpSize));
+		} else {
+			hfs_inode_read_fork(inode, rec->file.RExtRec, rec->file.RLgLen,
+					    rec->file.RPyLen, be16_to_cpu(rec->file.ClpSize));
+		}
+
+		inode->i_ino = be32_to_cpu(rec->file.FlNum);
+		inode->i_mode = S_IRUGO | S_IXUGO;
+		if (!(rec->file.Flags & HFS_FIL_LOCK))
+			inode->i_mode |= S_IWUGO;
+		inode->i_mode &= ~hsb->s_file_umask;
+		inode->i_mode |= S_IFREG;
+		mtime = hfs_m_to_utime(rec->file.MdDat);
+		inode_set_ctime_to_ts(inode, mtime);
+		inode_set_atime_to_ts(inode, mtime);
+		inode_set_mtime_to_ts(inode, mtime);
+		inode->i_op = &hfs_file_inode_operations;
+		inode->i_fop = &hfs_file_operations;
+		inode->i_mapping->a_ops = &hfs_aops;
+		break;
+	case HFS_CDR_DIR:
+		if (!hfs_is_valid_cnid(be32_to_cpu(rec->dir.DirID), rec->type))
+			return -EIO;
+
+		inode->i_ino = be32_to_cpu(rec->dir.DirID);
+		inode->i_size = be16_to_cpu(rec->dir.Val) + 2;
+		HFS_I(inode)->fs_blocks = 0;
+		inode->i_mode = S_IFDIR | (S_IRWXUGO & ~hsb->s_dir_umask);
+		mtime = hfs_m_to_utime(rec->dir.MdDat);
+		inode_set_ctime_to_ts(inode, mtime);
+		inode_set_atime_to_ts(inode, mtime);
+		inode_set_mtime_to_ts(inode, mtime);
+		inode->i_op = &hfs_dir_inode_operations;
+		inode->i_fop = &hfs_dir_operations;
+		break;
+	default:
+		make_bad_inode(inode);
+	}
+	return 0;
+}
+
+/*
+ * __hfs_iget()
+ *
+ * Given the MDB for a HFS filesystem, a 'key' and an 'entry' in
+ * the catalog B-tree and the 'type' of the desired file return the
+ * inode for that file/directory or NULL.  Note that 'type' indicates
+ * whether we want the actual file or directory, or the corresponding
+ * metadata (AppleDouble header file or CAP metadata file).
+ */
+struct inode *hfs_iget(struct super_block *sb, struct hfs_cat_key *key, hfs_cat_rec *rec)
+{
+	struct hfs_iget_data data = { key, rec };
+	struct inode *inode;
+	u32 cnid;
+
+	switch (rec->type) {
+	case HFS_CDR_DIR:
+		cnid = be32_to_cpu(rec->dir.DirID);
+		break;
+	case HFS_CDR_FIL:
+		cnid = be32_to_cpu(rec->file.FlNum);
+		break;
+	default:
+		return NULL;
+	}
+	inode = iget5_locked(sb, cnid, hfs_test_inode, hfs_read_inode, &data);
+	if (inode && (inode_state_read_once(inode) & I_NEW))
+		unlock_new_inode(inode);
+	return inode;
+}
+
+void hfs_inode_write_fork(struct inode *inode, struct hfs_extent *ext,
+			  __be32 *log_size, __be32 *phys_size)
+{
+	memcpy(ext, HFS_I(inode)->first_extents, sizeof(hfs_extent_rec));
+
+	if (log_size)
+		*log_size = cpu_to_be32(inode->i_size);
+	if (phys_size)
+		*phys_size = cpu_to_be32(HFS_I(inode)->alloc_blocks *
+					 HFS_SB(inode->i_sb)->alloc_blksz);
+}
+
+int hfs_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+	struct inode *main_inode = inode;
+	struct hfs_find_data fd;
+	hfs_cat_rec rec;
+	int res;
+
+	hfs_dbg("ino %llu\n", inode->i_ino);
+	res = hfs_ext_write_extent(inode);
+	if (res)
+		return res;
+
+	if (inode->i_ino < HFS_FIRSTUSER_CNID) {
+		switch (inode->i_ino) {
+		case HFS_ROOT_CNID:
+			break;
+		case HFS_EXT_CNID:
+			hfs_btree_write(HFS_SB(inode->i_sb)->ext_tree);
+			return 0;
+		case HFS_CAT_CNID:
+			hfs_btree_write(HFS_SB(inode->i_sb)->cat_tree);
+			return 0;
+		default:
+			BUG();
+			return -EIO;
+		}
+	}
+
+	if (HFS_IS_RSRC(inode))
+		main_inode = HFS_I(inode)->rsrc_inode;
+
+	if (!main_inode->i_nlink)
+		return 0;
+
+	if (hfs_find_init(HFS_SB(main_inode->i_sb)->cat_tree, &fd))
+		/* panic? */
+		return -EIO;
+
+	res = -EIO;
+	if (HFS_I(main_inode)->cat_key.CName.len > HFS_NAMELEN)
+		goto out;
+	fd.search_key->cat = HFS_I(main_inode)->cat_key;
+	if (hfs_brec_find(&fd))
+		goto out;
+
+	if (S_ISDIR(main_inode->i_mode)) {
+		if (fd.entrylength < sizeof(struct hfs_cat_dir))
+			goto out;
+		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
+			   sizeof(struct hfs_cat_dir));
+		if (rec.type != HFS_CDR_DIR ||
+		    be32_to_cpu(rec.dir.DirID) != inode->i_ino) {
+		}
+
+		rec.dir.MdDat = hfs_u_to_mtime(inode_get_mtime(inode));
+		rec.dir.Val = cpu_to_be16(inode->i_size - 2);
+
+		hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
+			    sizeof(struct hfs_cat_dir));
+	} else if (HFS_IS_RSRC(inode)) {
+		if (fd.entrylength < sizeof(struct hfs_cat_file))
+			goto out;
+		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
+			       sizeof(struct hfs_cat_file));
+		hfs_inode_write_fork(inode, rec.file.RExtRec,
+				     &rec.file.RLgLen, &rec.file.RPyLen);
+		hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
+				sizeof(struct hfs_cat_file));
+	} else {
+		if (fd.entrylength < sizeof(struct hfs_cat_file))
+			goto out;
+		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
+			   sizeof(struct hfs_cat_file));
+		if (rec.type != HFS_CDR_FIL ||
+		    be32_to_cpu(rec.file.FlNum) != inode->i_ino) {
+		}
+
+		if (inode->i_mode & S_IWUSR)
+			rec.file.Flags &= ~HFS_FIL_LOCK;
+		else
+			rec.file.Flags |= HFS_FIL_LOCK;
+		hfs_inode_write_fork(inode, rec.file.ExtRec, &rec.file.LgLen, &rec.file.PyLen);
+		rec.file.MdDat = hfs_u_to_mtime(inode_get_mtime(inode));
+
+		hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
+			    sizeof(struct hfs_cat_file));
+	}
+	res = 0;
+out:
+	hfs_find_exit(&fd);
+	return res;
+}
+
+static struct dentry *hfs_file_lookup(struct inode *dir, struct dentry *dentry,
+				      unsigned int flags)
+{
+	struct inode *inode = NULL;
+	hfs_cat_rec rec;
+	struct hfs_find_data fd;
+	int res;
+
+	if (HFS_IS_RSRC(dir) || strcmp(dentry->d_name.name, "rsrc"))
+		goto out;
+
+	inode = HFS_I(dir)->rsrc_inode;
+	if (inode)
+		goto out;
+
+	inode = new_inode(dir->i_sb);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+
+	res = hfs_find_init(HFS_SB(dir->i_sb)->cat_tree, &fd);
+	if (res) {
+		iput(inode);
+		return ERR_PTR(res);
+	}
+	fd.search_key->cat = HFS_I(dir)->cat_key;
+	res = hfs_brec_read(&fd, &rec, sizeof(rec));
+	if (!res) {
+		struct hfs_iget_data idata = { NULL, &rec };
+		res = hfs_read_inode(inode, &idata);
+	}
+	hfs_find_exit(&fd);
+	if (res) {
+		iput(inode);
+		return ERR_PTR(res);
+	}
+
+	if (is_bad_inode(inode)) {
+		iput(inode);
+		return ERR_PTR(-EIO);
+	}
+	HFS_I(inode)->rsrc_inode = dir;
+	HFS_I(dir)->rsrc_inode = inode;
+	igrab(dir);
+	inode_fake_hash(inode);
+	mark_inode_dirty(inode);
+	dont_mount(dentry);
+out:
+	return d_splice_alias(inode, dentry);
+}
+
+void hfs_evict_inode(struct inode *inode)
+{
+	truncate_inode_pages_final(&inode->i_data);
+	clear_inode(inode);
+	if (HFS_IS_RSRC(inode) && HFS_I(inode)->rsrc_inode) {
+		HFS_I(HFS_I(inode)->rsrc_inode)->rsrc_inode = NULL;
+		iput(HFS_I(inode)->rsrc_inode);
+	}
+}
+
+static int hfs_file_open(struct inode *inode, struct file *file)
+{
+	if (HFS_IS_RSRC(inode))
+		inode = HFS_I(inode)->rsrc_inode;
+	atomic_inc(&HFS_I(inode)->opencnt);
+	return 0;
+}
+
+static int hfs_file_release(struct inode *inode, struct file *file)
+{
+	//struct super_block *sb = inode->i_sb;
+
+	if (HFS_IS_RSRC(inode))
+		inode = HFS_I(inode)->rsrc_inode;
+	if (atomic_dec_and_test(&HFS_I(inode)->opencnt)) {
+		inode_lock(inode);
+		hfs_file_truncate(inode);
+		//if (inode->i_flags & S_DEAD) {
+		//	hfs_delete_cat(inode->i_ino, HFSPLUS_SB(sb).hidden_dir, NULL);
+		//	hfs_delete_inode(inode);
+		//}
+		inode_unlock(inode);
+	}
+	return 0;
+}
+
+int hfs_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
+		      struct iattr *attr)
+{
+	struct inode *inode = d_inode(dentry);
+	struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
+	int error;
+
+	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
+	if (error)
+		return error;
+
+	/* no uig/gid changes and limit which mode bits can be set */
+	if (((attr->ia_valid & ATTR_UID) &&
+	     (!uid_eq(attr->ia_uid, hsb->s_uid))) ||
+	    ((attr->ia_valid & ATTR_GID) &&
+	     (!gid_eq(attr->ia_gid, hsb->s_gid))) ||
+	    ((attr->ia_valid & ATTR_MODE) &&
+	     ((S_ISDIR(inode->i_mode) &&
+	       (attr->ia_mode != inode->i_mode)) ||
+	      (attr->ia_mode & ~HFS_VALID_MODE_BITS)))) {
+		return hsb->s_quiet ? 0 : error;
+	}
+
+	/* map file permissions to the closest allowable permissions in HFS */
+	if (attr->ia_valid & ATTR_MODE) {
+		/* Only the 'w' bits can ever change and only all together. */
+		if (attr->ia_mode & S_IWUSR)
+			attr->ia_mode = inode->i_mode | S_IWUGO;
+		else
+			attr->ia_mode = inode->i_mode & ~S_IWUGO;
+		attr->ia_mode &= S_ISDIR(inode->i_mode) ? ~hsb->s_dir_umask: ~hsb->s_file_umask;
+	}
+
+	if ((attr->ia_valid & ATTR_SIZE) &&
+	    attr->ia_size != i_size_read(inode)) {
+		inode_dio_wait(inode);
+
+		error = inode_newsize_ok(inode, attr->ia_size);
+		if (error)
+			return error;
+
+		truncate_setsize(inode, attr->ia_size);
+		hfs_file_truncate(inode);
+		inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
+	}
+
+	setattr_copy(&nop_mnt_idmap, inode, attr);
+	mark_inode_dirty(inode);
+	return 0;
+}
+
+static int hfs_file_fsync(struct file *filp, loff_t start, loff_t end,
+			  int datasync)
+{
+	struct inode *inode = filp->f_mapping->host;
+	struct super_block * sb;
+	int ret, err;
+
+	ret = file_write_and_wait_range(filp, start, end);
+	if (ret)
+		return ret;
+	inode_lock(inode);
+
+	/* sync the inode to buffers */
+	ret = write_inode_now(inode, 0);
+
+	/* sync the superblock to buffers */
+	sb = inode->i_sb;
+	flush_delayed_work(&HFS_SB(sb)->mdb_work);
+	/* .. finally sync the buffers to disk */
+	err = sync_blockdev(sb->s_bdev);
+	if (!ret)
+		ret = err;
+	inode_unlock(inode);
+	return ret;
+}
+
+int hfs_fileattr_get(struct dentry *dentry, struct file_kattr *fa)
+{
+	/*
+	 * HFS compares filenames using Mac OS Roman case folding, so
+	 * lookup is always case-insensitive. Names are stored on disk
+	 * with case intact; CASENONPRESERVING stays clear.
+	 */
+	fa->fsx_xflags |= FS_XFLAG_CASEFOLD;
+	fa->flags |= FS_CASEFOLD_FL;
+	return 0;
+}
+
+static const struct file_operations hfs_file_operations = {
+	.llseek		= generic_file_llseek,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
+	.mmap_prepare	= generic_file_mmap_prepare,
+	.splice_read	= filemap_splice_read,
+	.splice_write	= iter_file_splice_write,
+	.fsync		= hfs_file_fsync,
+	.open		= hfs_file_open,
+	.release	= hfs_file_release,
+};
+
+static const struct inode_operations hfs_file_inode_operations = {
+	.lookup		= hfs_file_lookup,
+	.setattr	= hfs_inode_setattr,
+	.listxattr	= generic_listxattr,
+	.fileattr_get	= hfs_fileattr_get,
+};