The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x d1aa0c04294e29883d65eac6c2f72fe95cc7c049 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024111703-shopper-overtly-8e35@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From d1aa0c04294e29883d65eac6c2f72fe95cc7c049 Mon Sep 17 00:00:00 2001 From: Andrew Morton akpm@linux-foundation.org Date: Fri, 15 Nov 2024 16:57:24 -0800 Subject: [PATCH] mm: revert "mm: shmem: fix data-race in shmem_getattr()"

Revert d949d1d14fa2 ("mm: shmem: fix data-race in shmem_getattr()") as suggested by Chuck [1]. It is causing deadlocks when accessing tmpfs over NFS.

As Hugh commented, "added just to silence a syzbot sanitizer splat: added where there has never been any practical problem".

Link: https://lkml.kernel.org/r/ZzdxKF39VEmXSSyN@tissot.1015granger.net [1] Fixes: d949d1d14fa2 ("mm: shmem: fix data-race in shmem_getattr()") Acked-by: Hugh Dickins hughd@google.com Cc: Chuck Lever chuck.lever@oracle.com Cc: Jeongjun Park aha310510@gmail.com Cc: Yu Zhao yuzhao@google.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org

diff --git a/mm/shmem.c b/mm/shmem.c index e87f5d6799a7..568bb290bdce 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1166,9 +1166,7 @@ static int shmem_getattr(struct mnt_idmap *idmap, stat->attributes_mask |= (STATX_ATTR_APPEND | STATX_ATTR_IMMUTABLE | STATX_ATTR_NODUMP); - inode_lock_shared(inode); generic_fillattr(idmap, request_mask, inode, stat); - inode_unlock_shared(inode);

if (shmem_huge_global_enabled(inode, 0, 0, false, NULL, 0)) stat->blksize = HPAGE_PMD_SIZE;