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.
Fixes: e809d5f0b5c9 ("tmpfs: per-superblock i_ino support")
Cc: Chris Down <chris@xxxxxxxxxxxxxx>
Signed-off-by: Byron Stanoszek <gandalf@xxxxxxxxx>