Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 498 insertions, 0 deletions

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);
+}