Commit 0a8eba9b authored Jun 14, 2009 by Mike Frysinger Committed by Linus Torvalds Jun 14, 2009

ramfs: ignore unknown mount options



On systems where CONFIG_SHMEM is disabled, mounting tmpfs filesystems can
fail when tmpfs options are used.  This is because tmpfs creates a small
wrapper around ramfs which rejects unknown options, and ramfs itself only
supports a tiny subset of what tmpfs supports.  This makes it pretty hard
to use the same userspace systems across different configuration systems.
As such, ramfs should ignore the tmpfs options when tmpfs is merely a
wrapper around ramfs.

This used to work before commit c3b1b1cb as previously, ramfs would
ignore all options.  But now, we get:
ramfs: bad mount option: size=10M
mount: mounting mdev on /dev failed: Invalid argument

Another option might be to restore the previous behavior, where ramfs
simply ignored all unknown mount options ... which is what Hugh prefers.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Acked-by: Matt Mackall <mpm@selenic.com>
Acked-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 45e3e193

fs/ramfs/inode.c

+6 −3

Original line number	Diff line number	Diff line
		@@ -202,9 +202,12 @@ static int ramfs_parse_options(char data, struct ramfs_mount_opts opts)
		return -EINVAL;
		opts->mode = option & S_IALLUGO;
		break;
		default:
		printk(KERN_ERR "ramfs: bad mount option: %s\n", p);
		return -EINVAL;
		/*
		* We might like to report bad mount options here;
		* but traditionally ramfs has ignored all mount options,
		* and as it is used as a !CONFIG_SHMEM simple substitute
		* for tmpfs, better continue to ignore other mount options.
		*/
		}
		}

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