Commit bb3e96d6 authored Sep 18, 2020 by Byron Stanoszek Committed by Linus Torvalds Sep 19, 2020

tmpfs: restore functionality of nr_inodes=0



Commit e809d5f0 ("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.

Fixes: e809d5f0 ("tmpfs: per-superblock i_ino support")
Signed-off-by: Byron Stanoszek <gandalf@winds.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Chris Down <chris@chrisdown.name>
Link: https://lkml.kernel.org/r/20200902035715.16414-1-gandalf@winds.org


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 0964730b

mm/shmem.c

+6 −4

Original line number	Diff line number	Diff line
		@@ -279,11 +279,13 @@ static int shmem_reserve_inode(struct super_block sb, ino_t inop)

		if (!(sb->s_flags & SB_KERNMOUNT)) {
		spin_lock(&sbinfo->stat_lock);
		if (sbinfo->max_inodes) {
		if (!sbinfo->free_inodes) {
		spin_unlock(&sbinfo->stat_lock);
		return -ENOSPC;
		}
		sbinfo->free_inodes--;
		}
		if (inop) {
		ino = sbinfo->next_ino++;
		if (unlikely(is_zero_ino(ino)))

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