This is a note to let you know that I've just added the patch titled xfs: terminate perag iteration reliably on agcount 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: xfs-terminate-perag-iteration-reliably-on-agcount.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 foo@baz Sat Jul 23 05:23:15 PM CEST 2022 From: Leah Rumancik <leah.rumancik@xxxxxxxxx> Date: Thu, 21 Jul 2022 14:36:08 -0700 Subject: xfs: terminate perag iteration reliably on agcount To: stable@xxxxxxxxxxxxxxx, linux-xfs@xxxxxxxxxxxxxxx Cc: amir73il@xxxxxxxxx, Brian Foster <bfoster@xxxxxxxxxx>, Dave Chinner <dchinner@xxxxxxxxxx>, "Darrick J . Wong" <djwong@xxxxxxxxxx>, Leah Rumancik <leah.rumancik@xxxxxxxxx> Message-ID: <20220721213610.2794134-5-leah.rumancik@xxxxxxxxx> From: Brian Foster <bfoster@xxxxxxxxxx> [ Upstream commit 8ed004eb9d07a5d6114db3e97a166707c186262d ] The for_each_perag_from() iteration macro relies on sb_agcount to process every perag currently within EOFS from a given starting point. It's perfectly valid to have perag structures beyond sb_agcount, however, such as if a growfs is in progress. If a perag loop happens to race with growfs in this manner, it will actually attempt to process the post-EOFS perag where ->pag_agno == sb_agcount. This is reproduced by xfs/104 and manifests as the following assert failure in superblock write verifier context: XFS: Assertion failed: agno < mp->m_sb.sb_agcount, file: fs/xfs/libxfs/xfs_types.c, line: 22 Update the corresponding macro to only process perags that are within the current sb_agcount. Fixes: 58d43a7e3263 ("xfs: pass perags around in fsmap data dev functions") Signed-off-by: Brian Foster <bfoster@xxxxxxxxxx> Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx> Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx> Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx> Signed-off-by: Leah Rumancik <leah.rumancik@xxxxxxxxx> Acked-by: Darrick J. Wong <djwong@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/xfs/libxfs/xfs_ag.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/xfs/libxfs/xfs_ag.h +++ b/fs/xfs/libxfs/xfs_ag.h @@ -142,7 +142,7 @@ xfs_perag_next( (pag) = xfs_perag_next((pag), &(agno))) #define for_each_perag_from(mp, agno, pag) \ - for_each_perag_range((mp), (agno), (mp)->m_sb.sb_agcount, (pag)) + for_each_perag_range((mp), (agno), (mp)->m_sb.sb_agcount - 1, (pag)) #define for_each_perag(mp, agno, pag) \ Patches currently in stable-queue which might be from leah.rumancik@xxxxxxxxx are queue-5.15/xfs-prevent-a-warn_once-in-xfs_ioc_attr_list.patch queue-5.15/xfs-rename-the-next_agno-perag-iteration-variable.patch queue-5.15/xfs-fix-perag-reference-leak-on-iteration-race-with-growfs.patch queue-5.15/xfs-terminate-perag-iteration-reliably-on-agcount.patch queue-5.15/xfs-fold-perag-loop-iteration-logic-into-helper-function.patch queue-5.15/xfs-fix-maxlevels-comparisons-in-the-btree-staging-code.patch