This is a note to let you know that I've just added the patch titled
btrfs: fix space cache inconsistency after error loading it from disk
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
btrfs-fix-space-cache-inconsistency-after-error-loading-it-from-disk.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 0004ff15ea26015a0a3a6182dca3b9d1df32e2b7 Mon Sep 17 00:00:00 2001
From: Filipe Manana <fdmanana@xxxxxxxx>
Date: Thu, 4 May 2023 12:04:18 +0100
Subject: btrfs: fix space cache inconsistency after error loading it from disk
From: Filipe Manana <fdmanana@xxxxxxxx>
commit 0004ff15ea26015a0a3a6182dca3b9d1df32e2b7 upstream.
When loading a free space cache from disk, at __load_free_space_cache(),
if we fail to insert a bitmap entry, we still increment the number of
total bitmaps in the btrfs_free_space_ctl structure, which is incorrect
since we failed to add the bitmap entry. On error we then empty the
cache by calling __btrfs_remove_free_space_cache(), which will result
in getting the total bitmaps counter set to 1.
A failure to load a free space cache is not critical, so if a failure
happens we just rebuild the cache by scanning the extent tree, which
happens at block-group.c:caching_thread(). Yet the failure will result
in having the total bitmaps of the btrfs_free_space_ctl always bigger
by 1 then the number of bitmap entries we have. So fix this by having
the total bitmaps counter be incremented only if we successfully added
the bitmap entry.
Fixes: a67509c30079 ("Btrfs: add a io_ctl struct and helpers for dealing with the space cache")
Reviewed-by: Anand Jain <anand.jain@xxxxxxxxxx>
CC: stable@xxxxxxxxxxxxxxx # 4.4+
Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/btrfs/free-space-cache.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -825,15 +825,16 @@ static int __load_free_space_cache(struc
}
spin_lock(&ctl->tree_lock);
ret = link_free_space(ctl, e);
- ctl->total_bitmaps++;
- recalculate_thresholds(ctl);
- spin_unlock(&ctl->tree_lock);
if (ret) {
+ spin_unlock(&ctl->tree_lock);
btrfs_err(fs_info,
"Duplicate entries in free space cache, dumping");
kmem_cache_free(btrfs_free_space_cachep, e);
goto free_cache;
}
+ ctl->total_bitmaps++;
+ recalculate_thresholds(ctl);
+ spin_unlock(&ctl->tree_lock);
list_add_tail(&e->list, &bitmaps);
}
Patches currently in stable-queue which might be from fdmanana@xxxxxxxx are
queue-5.15/btrfs-fix-btrfs_prev_leaf-to-not-return-the-same-key-twice.patch
queue-5.15/btrfs-fix-space-cache-inconsistency-after-error-loading-it-from-disk.patch
