Commit d6db8ad7 authored by Miao Xie's avatar Miao Xie Committed by Ben Hutchings

Btrfs: fix inode caching vs tree log

commit 1c70d8fb upstream.

Currently, with inode cache enabled, we will reuse its inode id immediately
after unlinking file, we may hit something like following:

|->iput inode
|->return inode id into inode cache
|->create dir,fsync
|->power off

An easy way to reproduce this problem is:

mkfs.btrfs -f /dev/sdb
mount /dev/sdb /mnt -o inode_cache,commit=100
dd if=/dev/zero of=/mnt/data bs=1M count=10 oflag=sync
inode_id=`ls -i /mnt/data | awk '{print $1}'`
rm -f /mnt/data

i=1
while [ 1 ]
do
        mkdir /mnt/dir_$i
        test1=`stat /mnt/dir_$i | grep Inode: | awk '{print $4}'`
        if [ $test1 -eq $inode_id ]
        then
		dd if=/dev/zero of=/mnt/dir_$i/data bs=1M count=1 oflag=sync
		echo b > /proc/sysrq-trigger
	fi
	sleep 1
        i=$(($i+1))
done

mount /dev/sdb /mnt
umount /dev/sdb
btrfs check /dev/sdb

We fix this problem by adding unlinked inode's id into pinned tree,
and we can not reuse them until committing transaction.
Signed-off-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: default avatarWang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: default avatarChris Mason <clm@fb.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
parent 8bbfb31d
......@@ -207,24 +207,14 @@ int btrfs_find_free_ino(struct btrfs_root *root, u64 *objectid)
void btrfs_return_ino(struct btrfs_root *root, u64 objectid)
{
struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
struct btrfs_free_space_ctl *pinned = root->free_ino_pinned;
if (!btrfs_test_opt(root, INODE_MAP_CACHE))
return;
again:
if (root->cached == BTRFS_CACHE_FINISHED) {
__btrfs_add_free_space(ctl, objectid, 1);
__btrfs_add_free_space(pinned, objectid, 1);
} else {
/*
* If we are in the process of caching free ino chunks,
* to avoid adding the same inode number to the free_ino
* tree twice due to cross transaction, we'll leave it
* in the pinned tree until a transaction is committed
* or the caching work is done.
*/
mutex_lock(&root->fs_commit_mutex);
spin_lock(&root->cache_lock);
if (root->cached == BTRFS_CACHE_FINISHED) {
......@@ -236,11 +226,7 @@ void btrfs_return_ino(struct btrfs_root *root, u64 objectid)
start_caching(root);
if (objectid <= root->cache_progress ||
objectid >= root->highest_objectid)
__btrfs_add_free_space(ctl, objectid, 1);
else
__btrfs_add_free_space(pinned, objectid, 1);
__btrfs_add_free_space(pinned, objectid, 1);
mutex_unlock(&root->fs_commit_mutex);
}
......
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