tmpfs: fixups to use of the new mount API

Several fixups to shmem_parse_param() and tmpfs use of new mount API:

mm/shmem.c manages filesystem named "tmpfs": revert "shmem" to "tmpfs"
in its mount error messages.

/sys/kernel/mm/transparent_hugepage/shmem_enabled has valid options
"deny" and "force", but they are not valid as tmpfs "huge" options.

The "size" param is an alternative to "nr_blocks", and needs to be
recognized as changing max_blocks.  And where there's ambiguity, it's
better to mention "size" than "nr_blocks" in messages, since "size" is
the variant shown in /proc/mounts.

shmem_apply_options() left ctx->mpol as the new mpol, so then it was
freed in shmem_free_fc(), and the filesystem went on to use-after-free.

shmem_parse_param() issue "tmpfs: Bad value for '%s'" messages just
like fs_parse() would, instead of a different wording.  Where config
disables "mpol" or "huge", say "tmpfs: Unsupported parameter '%s'".

Fixes: 144df3b288c41 ("vfs: Convert ramfs, shmem, tmpfs, devtmpfs, rootfs to use the new mount API")
Signed-off-by: Hugh Dickins <>
Cc: David Howells <>
Cc: Al Viro <>
Signed-off-by: Andrew Morton <>
1 file changed