From a2982cc922c3068783eb9a1f77a5626a1ec36a1f Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Thu, 9 Jun 2016 15:34:02 -0500 Subject: vfs: Generalize filesystem nodev handling. Introduce a function may_open_dev that tests MNT_NODEV and a new superblock flab SB_I_NODEV. Use this new function in all of the places where MNT_NODEV was previously tested. Add the new SB_I_NODEV s_iflag to proc, sysfs, and mqueuefs as those filesystems should never support device nodes, and a simple superblock flags makes that very hard to get wrong. With SB_I_NODEV set if any device nodes somehow manage to show up on on a filesystem those device nodes will be unopenable. Acked-by: Seth Forshee Signed-off-by: "Eric W. Biederman" --- fs/block_dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/block_dev.c') diff --git a/fs/block_dev.c b/fs/block_dev.c index 71ccab1d22c6..30b8d568203a 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1857,7 +1857,7 @@ struct block_device *lookup_bdev(const char *pathname) if (!S_ISBLK(inode->i_mode)) goto fail; error = -EACCES; - if (path.mnt->mnt_flags & MNT_NODEV) + if (!may_open_dev(&path)) goto fail; error = -ENOMEM; bdev = bd_acquire(inode); -- cgit v1.2.3