This is a note to let you know that I've just added the patch titled
btrfs: set cache_block_group_error if we find an error
to the 4.19-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-set-cache_block_group_error-if-we-find-an-error.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 92fb94b69c6accf1e49fff699640fa0ce03dc910 Mon Sep 17 00:00:00 2001
From: Josef Bacik <josef@xxxxxxxxxxxxxx>
Date: Wed, 2 Aug 2023 09:20:24 -0400
Subject: btrfs: set cache_block_group_error if we find an error
From: Josef Bacik <josef@xxxxxxxxxxxxxx>
commit 92fb94b69c6accf1e49fff699640fa0ce03dc910 upstream.
We set cache_block_group_error if btrfs_cache_block_group() returns an
error, this is because we could end up not finding space to allocate and
mistakenly return -ENOSPC, and which could then abort the transaction
with the incorrect errno, and in the case of ENOSPC result in a
WARN_ON() that will trip up tests like generic/475.
However there's the case where multiple threads can be racing, one
thread gets the proper error, and the other thread doesn't actually call
btrfs_cache_block_group(), it instead sees ->cached ==
BTRFS_CACHE_ERROR. Again the result is the same, we fail to allocate
our space and return -ENOSPC. Instead we need to set
cache_block_group_error to -EIO in this case to make sure that if we do
not make our allocation we get the appropriate error returned back to
the caller.
CC: stable@xxxxxxxxxxxxxxx # 4.14+
Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/btrfs/extent-tree.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -7392,8 +7392,11 @@ have_block_group:
ret = 0;
}
- if (unlikely(block_group->cached == BTRFS_CACHE_ERROR))
+ if (unlikely(block_group->cached == BTRFS_CACHE_ERROR)) {
+ if (!cache_block_group_error)
+ cache_block_group_error = -EIO;
goto loop;
+ }
/*
* Ok we want to try and use the cluster allocator, so
Patches currently in stable-queue which might be from josef@xxxxxxxxxxxxxx are
queue-4.19/btrfs-don-t-stop-integrity-writeback-too-early.patch
queue-4.19/btrfs-set-cache_block_group_error-if-we-find-an-error.patch
queue-4.19/btrfs-don-t-wait-for-writeback-on-clean-pages-in-extent_write_cache_pages.patch
