This is a note to let you know that I've just added the patch titled nilfs2: prevent kernel bug at submit_bh_wbc() to the 6.8-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: nilfs2-prevent-kernel-bug-at-submit_bh_wbc.patch and it can be found in the queue-6.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 5829198e24223ae756c3fb748360ab08bef11f8c Author: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx> Date: Wed Mar 13 19:58:27 2024 +0900 nilfs2: prevent kernel bug at submit_bh_wbc() [ Upstream commit 269cdf353b5bdd15f1a079671b0f889113865f20 ] Fix a bug where nilfs_get_block() returns a successful status when searching and inserting the specified block both fail inconsistently. If this inconsistent behavior is not due to a previously fixed bug, then an unexpected race is occurring, so return a temporary error -EAGAIN instead. This prevents callers such as __block_write_begin_int() from requesting a read into a buffer that is not mapped, which would cause the BUG_ON check for the BH_Mapped flag in submit_bh_wbc() to fail. Link: https://lkml.kernel.org/r/20240313105827.5296-3-konishi.ryusuke@xxxxxxxxx Fixes: 1f5abe7e7dbc ("nilfs2: replace BUG_ON and BUG calls triggerable from ioctl") Signed-off-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c index 9c334c722fc1c..5a888b2c1803d 100644 --- a/fs/nilfs2/inode.c +++ b/fs/nilfs2/inode.c @@ -112,7 +112,7 @@ int nilfs_get_block(struct inode *inode, sector_t blkoff, "%s (ino=%lu): a race condition while inserting a data block at offset=%llu", __func__, inode->i_ino, (unsigned long long)blkoff); - err = 0; + err = -EAGAIN; } nilfs_transaction_abort(inode->i_sb); goto out;