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Btrfs: Give each subvol and snapshot their own anonymous devid

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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>
This commit is contained in:
Chris Mason
2008-11-17 20:42:26 -05:00
parent 3de4586c52
commit 3394e1607e
5 changed files with 34 additions and 6 deletions
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15
fs/btrfs/inode.c
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@ -2212,7 +2212,12 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
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 @@ int btrfs_create_subvol_root(struct btrfs_root *new_root, struct dentry *dentry,
if (error)
return error;
atomic_inc(&inode->i_count);
d_instantiate(dentry, inode);
return 0;
}
@ -4548,6 +4552,7 @@ static int btrfs_getattr(struct vfsmount *mnt,
{
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 @@ static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
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 int btrfs_permission(struct inode *inode, int mask)
}
static struct inode_operations btrfs_dir_inode_operations = {
.getattr = btrfs_getattr,
.lookup = btrfs_lookup,
.create = btrfs_create,
.unlink = btrfs_unlink,