From: Byron Stanoszek <gandalf@xxxxxxxxx>
Subject: tmpfs: restore functionality of nr_inodes=0
Commit e809d5f0b5c9 ("tmpfs: per-superblock i_ino support") made changes
to shmem_reserve_inode() in mm/shmem.c, however the original test for
(sbinfo->max_inodes) got dropped. This causes mounting tmpfs with option
nr_inodes=0 to fail:
# mount -ttmpfs -onr_inodes=0 none /ext0
mount: /ext0: mount(2) system call failed: Cannot allocate memory.
This patch restores the nr_inodes=0 functionality.
Link: https://lkml.kernel.org/r/20200902035715.16414-1-gandalf@xxxxxxxxx
Fixes: e809d5f0b5c9 ("tmpfs: per-superblock i_ino support")
Signed-off-by: Byron Stanoszek <gandalf@xxxxxxxxx>
Acked-by: Hugh Dickins <hughd@xxxxxxxxxx>
Acked-by: Chris Down <chris@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/shmem.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
--- a/mm/shmem.c~tmpfs-restore-functionality-of-nr_inodes=0
+++ a/mm/shmem.c
@@ -279,11 +279,13 @@ static int shmem_reserve_inode(struct su
if (!(sb->s_flags & SB_KERNMOUNT)) {
spin_lock(&sbinfo->stat_lock);
- if (!sbinfo->free_inodes) {
- spin_unlock(&sbinfo->stat_lock);
- return -ENOSPC;
+ if (sbinfo->max_inodes) {
+ if (!sbinfo->free_inodes) {
+ spin_unlock(&sbinfo->stat_lock);
+ return -ENOSPC;
+ }
+ sbinfo->free_inodes--;
}
- sbinfo->free_inodes--;
if (inop) {
ino = sbinfo->next_ino++;
if (unlikely(is_zero_ino(ino)))
_
