[PATCH AUTOSEL 6.1 02/12] nfs: propagate readlink errors in nfs_symlink_filler

[Sasha Levin]

From: Sagi Grimberg <sagi@xxxxxxxxxxx>

[ Upstream commit 134d0b3f2440cdddd12fc3444c9c0f62331ce6fc ]

There is an inherent race where a symlink file may have been overriden
(by a different client) between lookup and readlink, resulting in a
spurious EIO error returned to userspace. Fix this by propagating back
ESTALE errors such that the vfs will retry the lookup/get_link (similar
to nfs4_file_open) at least once.

Cc: Dan Aloni <dan.aloni@xxxxxxxxxxxx>
Signed-off-by: Sagi Grimberg <sagi@xxxxxxxxxxx>
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/nfs/symlink.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/nfs/symlink.c b/fs/nfs/symlink.c
index 0e27a2e4e68b8..13818129d268f 100644
--- a/fs/nfs/symlink.c
+++ b/fs/nfs/symlink.c
@@ -41,7 +41,7 @@ static int nfs_symlink_filler(struct file *file, struct folio *folio)
 error:
 	folio_set_error(folio);
 	folio_unlock(folio);
-	return -EIO;
+	return error;
 }
 
 static const char *nfs_get_link(struct dentry *dentry,
-- 
2.43.0