Commit 10975933 authored Nov 20, 2014 by Miklos Szeredi Committed by Al Viro Dec 17, 2014

init: fix read-write root mount



If mount flags don't have MS_RDONLY, iso9660 returns EACCES without actually
checking if it's an iso image.

This tricks mount_block_root() into retrying with MS_RDONLY.  This results
in a read-only root despite the "rw" boot parameter if the actual
filesystem was checked after iso9660.

I believe the behavior of iso9660 is okay, while that of mount_block_root()
is not.  It should rather try all types without MS_RDONLY and only then
retry with MS_RDONLY.

This change also makes the code more robust against the case when EACCES is
returned despite MS_RDONLY, which would've resulted in a lockup.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

parent 7d65cf10

init/do_mounts.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -395,8 +395,6 @@ void __init mount_block_root(char *name, int flags)
		case 0:
		goto out;
		case -EACCES:
		flags \|= MS_RDONLY;
		goto retry;
		case -EINVAL:
		continue;
		}
		@@ -419,6 +417,10 @@ void __init mount_block_root(char *name, int flags)
		#endif
		panic("VFS: Unable to mount root fs on %s", b);
		}
		if (!(flags & MS_RDONLY)) {
		flags \|= MS_RDONLY;
		goto retry;
		}

		printk("List of all partitions:\n");
		printk_all_partitions();