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authorJeff Mahoney <jeffm@suse.de>2011-08-15 21:27:21 +0400
committerChris Mason <chris.mason@oracle.com>2011-08-18 18:16:03 +0400
commitcb6db4e57632ba8589cc2f9fe1d0aa9116b87ab8 (patch)
tree6cfeb1989e0ffdd9b536f908eb97269d0ddcbe65 /fs
parent93ee7a9340d64f20295aacc3fb6a22b759323280 (diff)
downloadlinux-cb6db4e57632ba8589cc2f9fe1d0aa9116b87ab8.tar.xz
btrfs: btrfs_permission's RO check shouldn't apply to device nodes
This patch tightens the read-only access checks in btrfs_permission to match the constraints in inode_permission. Currently, even though the device node itself will be unmodified, read-write access to device nodes is denied to when the device node resides on a read-only subvolume or a is a file that has been marked read-only by the btrfs conversion utility. With this patch applied, the check only affects regular files, directories, and symlinks. It also restructures the code a bit so that we don't duplicate the MAY_WRITE check for both tests. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs')
-rw-r--r--fs/btrfs/inode.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 15fceefbca0a..0ccc7438ad34 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7354,11 +7354,15 @@ static int btrfs_set_page_dirty(struct page *page)
static int btrfs_permission(struct inode *inode, int mask)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
+ umode_t mode = inode->i_mode;
- if (btrfs_root_readonly(root) && (mask & MAY_WRITE))
- return -EROFS;
- if ((BTRFS_I(inode)->flags & BTRFS_INODE_READONLY) && (mask & MAY_WRITE))
- return -EACCES;
+ if (mask & MAY_WRITE &&
+ (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
+ if (btrfs_root_readonly(root))
+ return -EROFS;
+ if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
+ return -EACCES;
+ }
return generic_permission(inode, mask);
}