Btrfs: Give each subvol and snapshot their own anonymous devid
Each subvolume has its own private inode number space, and so we need
to fill in different device numbers for each subvolume to avoid confusing
applications.
This commit puts a struct super_block into struct btrfs_root so it can
call set_anon_super() and get a different device number generated for
each root.
btrfs_rename is changed to prevent renames across subvols.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index e163b1b..7ef79ce 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2212,7 +2212,12 @@
struct btrfs_trans_handle *trans;
unsigned long nr = 0;
- if (inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
+ /*
+ * the FIRST_FREE_OBJECTID check makes sure we don't try to rmdir
+ * the root of a subvolume or snapshot
+ */
+ if (inode->i_size > BTRFS_EMPTY_DIR_SIZE ||
+ inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) {
return -ENOTEMPTY;
}
@@ -4410,7 +4415,6 @@
if (error)
return error;
- atomic_inc(&inode->i_count);
d_instantiate(dentry, inode);
return 0;
}
@@ -4548,6 +4552,7 @@
{
struct inode *inode = dentry->d_inode;
generic_fillattr(inode, stat);
+ stat->dev = BTRFS_I(inode)->root->anon_super.s_dev;
stat->blksize = PAGE_CACHE_SIZE;
stat->blocks = (inode_get_bytes(inode) +
BTRFS_I(inode)->delalloc_bytes) >> 9;
@@ -4565,6 +4570,11 @@
u64 index = 0;
int ret;
+ /* we're not allowed to rename between subvolumes */
+ if (BTRFS_I(old_inode)->root->root_key.objectid !=
+ BTRFS_I(new_dir)->root->root_key.objectid)
+ return -EXDEV;
+
if (S_ISDIR(old_inode->i_mode) && new_inode &&
new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
return -ENOTEMPTY;
@@ -4920,6 +4930,7 @@
}
static struct inode_operations btrfs_dir_inode_operations = {
+ .getattr = btrfs_getattr,
.lookup = btrfs_lookup,
.create = btrfs_create,
.unlink = btrfs_unlink,
