commit 1a2180f6859c73c674809f9f82e36c94084682ba upstream.
Max Kellermann recently reported psi_group_cpu.tasks[NR_MEMSTALL] is incorrect in the 6.11.9 kernel.
The root cause appears to be that, since the problematic commit, bio can be NULL, causing psi_memstall_leave() to be skipped in z_erofs_submit_queue().
Reported-by: Max Kellermann max.kellermann@ionos.com Closes: https://lore.kernel.org/r/CAKPOu+8tvSowiJADW2RuKyofL_CSkm_SuyZA7ME5vMLWmL6pq... Fixes: 9e2f9d34dd12 ("erofs: handle overlapped pclusters out of crafted images properly") Reviewed-by: Chao Yu chao@kernel.org Link: https://lore.kernel.org/r/20241127085236.3538334-1-hsiangkao@linux.alibaba.c... Signed-off-by: Gao Xiang hsiangkao@linux.alibaba.com --- fs/erofs/zdata.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c index 9fa07436a4da..496e4c7c52a4 100644 --- a/fs/erofs/zdata.c +++ b/fs/erofs/zdata.c @@ -1730,11 +1730,10 @@ static void z_erofs_submit_queue(struct z_erofs_decompress_frontend *f, move_to_bypass_jobqueue(pcl, qtail, owned_head); } while (owned_head != Z_EROFS_PCLUSTER_TAIL);
- if (bio) { + if (bio) submit_bio(bio); - if (memstall) - psi_memstall_leave(&pflags); - } + if (memstall) + psi_memstall_leave(&pflags);
/* * although background is preferred, no one is pending for submission.