FAILED: patch "[PATCH] mm: revert "mm: shmem: fix data-race in shmem_getattr()"" failed to apply to 5.10-stable tree

The patch below does not apply to the 5.10-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 <[email protected]>.

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-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x d1aa0c04294e29883d65eac6c2f72fe95cc7c049
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2024111703-uncork-sincerity-4d6e@gregkh' --subject-prefix 'PATCH 5.10.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 <[email protected]>
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".

index e87f5d6799a7..568bb290bdce 100644
@@ -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;

For 5.10 and 5.4 and 4.19 please use this replacement patch:

From 98dfa72dd24347bfcbb9a60ac65ad42130ff44f5 Mon Sep 17 00:00:00 2001
From: Andrew Morton <[email protected]>
Date: Fri, 15 Nov 2024 16:57:24 -0800
Subject: [PATCH] mm: revert "mm: shmem: fix data-race in shmem_getattr()"

commit d1aa0c04294e29883d65eac6c2f72fe95cc7c049 upstream.

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".

---
 mm/shmem.c | 2 --
 1 file changed, 2 deletions(-)

index 8239a0beb01c..e173d83b4448 100644
@@ -1077,9 +1077,7 @@ static int shmem_getattr(const struct path *path, struct kstat *stat,
 		shmem_recalc_inode(inode);
 		spin_unlock_irq(&info->lock);
 	}
-	inode_lock_shared(inode);
 	generic_fillattr(inode, stat);
-	inode_unlock_shared(inode);
 
 	if (is_huge_enabled(sb_info))
 		stat->blksize = HPAGE_PMD_SIZE;

2.47.0.338.g60cca15819-goog

All now queued up, thanks!

greg k-h