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Btrfs: add snapshot/subvolume destroy ioctl

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This patch adds snapshot/subvolume destroy ioctl.  A subvolume that isn't being
used and doesn't contains links to other subvolumes can be destroyed.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Yan, Zheng 2009-09-21 16:00:26 -04:00 committed by Chris Mason
parent 4df27c4d5c
commit 76dda93c6a
12 changed files with 610 additions and 238 deletions
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12
fs/btrfs/ctree.h
View file

@ -839,9 +839,7 @@ struct btrfs_fs_info {
struct mutex transaction_kthread_mutex;
struct mutex cleaner_mutex;
struct mutex chunk_mutex;
struct mutex drop_mutex;
struct mutex volume_mutex;
struct mutex tree_reloc_mutex;
/*
* this protects the ordered operations list only while we are
* processing all of the entries on it. This way we make
@ -852,6 +850,10 @@ struct btrfs_fs_info {
struct mutex ordered_operations_mutex;
struct rw_semaphore extent_commit_sem;
struct rw_semaphore subvol_sem;
struct srcu_struct subvol_srcu;
struct list_head trans_list;
struct list_head hashers;
struct list_head dead_roots;
@ -2142,6 +2144,7 @@ int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, struct
int btrfs_search_root(struct btrfs_root *root, u64 search_start,
u64 *found_objectid);
int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid);
int btrfs_find_orphan_roots(struct btrfs_root *tree_root);
int btrfs_set_root_node(struct btrfs_root_item *item,
struct extent_buffer *node);
/* dir-item.c */
@ -2273,7 +2276,7 @@ int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end);
int btrfs_writepages(struct address_space *mapping,
struct writeback_control *wbc);
int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
struct btrfs_root *new_root, struct dentry *dentry,
struct btrfs_root *new_root,
u64 new_dirid, u64 alloc_hint);
int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
size_t size, struct bio *bio, unsigned long bio_flags);
@ -2289,6 +2292,7 @@ int btrfs_write_inode(struct inode *inode, int wait);
void btrfs_dirty_inode(struct inode *inode);
struct inode *btrfs_alloc_inode(struct super_block *sb);
void btrfs_destroy_inode(struct inode *inode);
void btrfs_drop_inode(struct inode *inode);
int btrfs_init_cachep(void);
void btrfs_destroy_cachep(void);
long btrfs_ioctl_trans_end(struct file *file);
@ -2306,6 +2310,8 @@ int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode);
int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode);
void btrfs_orphan_cleanup(struct btrfs_root *root);
int btrfs_cont_expand(struct inode *inode, loff_t size);
int btrfs_invalidate_inodes(struct btrfs_root *root);
extern struct dentry_operations btrfs_dentry_operations;
/* ioctl.c */
long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);

81
fs/btrfs/disk-io.c
View file

@ -1378,8 +1378,10 @@ static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
err = bdi_register(bdi, NULL, "btrfs-%d",
atomic_inc_return(&btrfs_bdi_num));
if (err)
if (err) {
bdi_destroy(bdi);
return err;
}
bdi->ra_pages = default_backing_dev_info.ra_pages;
bdi->unplug_io_fn = btrfs_unplug_io_fn;
@ -1469,9 +1471,12 @@ static int cleaner_kthread(void *arg)
break;
vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
mutex_lock(&root->fs_info->cleaner_mutex);
btrfs_clean_old_snapshots(root);
mutex_unlock(&root->fs_info->cleaner_mutex);
if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
mutex_trylock(&root->fs_info->cleaner_mutex)) {
btrfs_clean_old_snapshots(root);
mutex_unlock(&root->fs_info->cleaner_mutex);
}
if (freezing(current)) {
refrigerator();
@ -1576,7 +1581,26 @@ struct btrfs_root *open_ctree(struct super_block *sb,
err = -ENOMEM;
goto fail;
}
INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
ret = init_srcu_struct(&fs_info->subvol_srcu);
if (ret) {
err = ret;
goto fail;
}
ret = setup_bdi(fs_info, &fs_info->bdi);
if (ret) {
err = ret;
goto fail_srcu;
}
fs_info->btree_inode = new_inode(sb);
if (!fs_info->btree_inode) {
err = -ENOMEM;
goto fail_bdi;
}
INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
INIT_LIST_HEAD(&fs_info->trans_list);
INIT_LIST_HEAD(&fs_info->dead_roots);
INIT_LIST_HEAD(&fs_info->hashers);
@ -1586,6 +1610,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
spin_lock_init(&fs_info->delalloc_lock);
spin_lock_init(&fs_info->new_trans_lock);
spin_lock_init(&fs_info->ref_cache_lock);
spin_lock_init(&fs_info->fs_roots_radix_lock);
init_completion(&fs_info->kobj_unregister);
fs_info->tree_root = tree_root;
@ -1604,11 +1629,6 @@ struct btrfs_root *open_ctree(struct super_block *sb,
fs_info->sb = sb;
fs_info->max_extent = (u64)-1;
fs_info->max_inline = 8192 * 1024;
if (setup_bdi(fs_info, &fs_info->bdi))
goto fail_bdi;
fs_info->btree_inode = new_inode(sb);
fs_info->btree_inode->i_ino = 1;
fs_info->btree_inode->i_nlink = 1;
fs_info->metadata_ratio = 8;
fs_info->thread_pool_size = min_t(unsigned long,
@ -1620,6 +1640,8 @@ struct btrfs_root *open_ctree(struct super_block *sb,
sb->s_blocksize = 4096;
sb->s_blocksize_bits = blksize_bits(4096);
fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
fs_info->btree_inode->i_nlink = 1;
/*
* we set the i_size on the btree inode to the max possible int.
* the real end of the address space is determined by all of
@ -1638,6 +1660,11 @@ struct btrfs_root *open_ctree(struct super_block *sb,
BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
BTRFS_I(fs_info->btree_inode)->root = tree_root;
memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
sizeof(struct btrfs_key));
BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
spin_lock_init(&fs_info->block_group_cache_lock);
fs_info->block_group_cache_tree.rb_node = NULL;
@ -1648,21 +1675,16 @@ struct btrfs_root *open_ctree(struct super_block *sb,
fs_info->pinned_extents = &fs_info->freed_extents[0];
fs_info->do_barriers = 1;
BTRFS_I(fs_info->btree_inode)->root = tree_root;
memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
sizeof(struct btrfs_key));
insert_inode_hash(fs_info->btree_inode);
mutex_init(&fs_info->trans_mutex);
mutex_init(&fs_info->ordered_operations_mutex);
mutex_init(&fs_info->tree_log_mutex);
mutex_init(&fs_info->drop_mutex);
mutex_init(&fs_info->chunk_mutex);
mutex_init(&fs_info->transaction_kthread_mutex);
mutex_init(&fs_info->cleaner_mutex);
mutex_init(&fs_info->volume_mutex);
mutex_init(&fs_info->tree_reloc_mutex);
init_rwsem(&fs_info->extent_commit_sem);
init_rwsem(&fs_info->subvol_sem);
btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
@ -1941,6 +1963,9 @@ printk("thread pool is %d\n", fs_info->thread_pool_size);
}
}
ret = btrfs_find_orphan_roots(tree_root);
BUG_ON(ret);
if (!(sb->s_flags & MS_RDONLY)) {
ret = btrfs_recover_relocation(tree_root);
BUG_ON(ret);
@ -2000,6 +2025,8 @@ printk("thread pool is %d\n", fs_info->thread_pool_size);
btrfs_mapping_tree_free(&fs_info->mapping_tree);
fail_bdi:
bdi_destroy(&fs_info->bdi);
fail_srcu:
cleanup_srcu_struct(&fs_info->subvol_srcu);
fail:
kfree(extent_root);
kfree(tree_root);
@ -2263,6 +2290,10 @@ int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
radix_tree_delete(&fs_info->fs_roots_radix,
(unsigned long)root->root_key.objectid);
spin_unlock(&fs_info->fs_roots_radix_lock);
if (btrfs_root_refs(&root->root_item) == 0)
synchronize_srcu(&fs_info->subvol_srcu);
free_fs_root(root);
return 0;
}
@ -2286,6 +2317,20 @@ static int del_fs_roots(struct btrfs_fs_info *fs_info)
struct btrfs_root *gang[8];
int i;
while (!list_empty(&fs_info->dead_roots)) {
gang[0] = list_entry(fs_info->dead_roots.next,
struct btrfs_root, root_list);
list_del(&gang[0]->root_list);
if (gang[0]->in_radix) {
btrfs_free_fs_root(fs_info, gang[0]);
} else {
free_extent_buffer(gang[0]->node);
free_extent_buffer(gang[0]->commit_root);
kfree(gang[0]);
}
}
while (1) {
ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
(void **)gang, 0,
@ -2315,9 +2360,6 @@ int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
root_objectid = gang[ret - 1]->root_key.objectid + 1;
for (i = 0; i < ret; i++) {
root_objectid = gang[i]->root_key.objectid;
ret = btrfs_find_dead_roots(fs_info->tree_root,
root_objectid);
BUG_ON(ret);
btrfs_orphan_cleanup(gang[i]);
}
root_objectid++;
@ -2405,6 +2447,7 @@ int close_ctree(struct btrfs_root *root)
btrfs_mapping_tree_free(&fs_info->mapping_tree);
bdi_destroy(&fs_info->bdi);
cleanup_srcu_struct(&fs_info->subvol_srcu);
kfree(fs_info->extent_root);
kfree(fs_info->tree_root);

137
fs/btrfs/export.c
View file

@ -28,7 +28,7 @@ static int btrfs_encode_fh(struct dentry *dentry, u32 *fh, int *max_len,
len = BTRFS_FID_SIZE_NON_CONNECTABLE;
type = FILEID_BTRFS_WITHOUT_PARENT;
fid->objectid = BTRFS_I(inode)->location.objectid;
fid->objectid = inode->i_ino;
fid->root_objectid = BTRFS_I(inode)->root->objectid;
fid->gen = inode->i_generation;
@ -60,34 +60,61 @@ static int btrfs_encode_fh(struct dentry *dentry, u32 *fh, int *max_len,
}
static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
u64 root_objectid, u32 generation)
u64 root_objectid, u32 generation,
int check_generation)
{
struct btrfs_fs_info *fs_info = btrfs_sb(sb)->fs_info;
struct btrfs_root *root;
struct dentry *dentry;
struct inode *inode;
struct btrfs_key key;
int index;
int err = 0;
if (objectid < BTRFS_FIRST_FREE_OBJECTID)
return ERR_PTR(-ESTALE);
key.objectid = root_objectid;
btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
key.offset = (u64)-1;
root = btrfs_read_fs_root_no_name(btrfs_sb(sb)->fs_info, &key);
if (IS_ERR(root))
return ERR_CAST(root);
index = srcu_read_lock(&fs_info->subvol_srcu);
root = btrfs_read_fs_root_no_name(fs_info, &key);
if (IS_ERR(root)) {
err = PTR_ERR(root);
goto fail;
}
if (btrfs_root_refs(&root->root_item) == 0) {
err = -ENOENT;
goto fail;
}
key.objectid = objectid;
btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
key.offset = 0;
inode = btrfs_iget(sb, &key, root);
if (IS_ERR(inode))
return (void *)inode;
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto fail;
}
if (generation != inode->i_generation) {
srcu_read_unlock(&fs_info->subvol_srcu, index);
if (check_generation && generation != inode->i_generation) {
iput(inode);
return ERR_PTR(-ESTALE);
}
return d_obtain_alias(inode);
dentry = d_obtain_alias(inode);
if (!IS_ERR(dentry))
dentry->d_op = &btrfs_dentry_operations;
return dentry;
fail:
srcu_read_unlock(&fs_info->subvol_srcu, index);
return ERR_PTR(err);
}
static struct dentry *btrfs_fh_to_parent(struct super_block *sb, struct fid *fh,
@ -111,7 +138,7 @@ static struct dentry *btrfs_fh_to_parent(struct super_block *sb, struct fid *fh,
objectid = fid->parent_objectid;
generation = fid->parent_gen;
return btrfs_get_dentry(sb, objectid, root_objectid, generation);
return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
}
static struct dentry *btrfs_fh_to_dentry(struct super_block *sb, struct fid *fh,
@ -133,66 +160,76 @@ static struct dentry *btrfs_fh_to_dentry(struct super_block *sb, struct fid *fh,
root_objectid = fid->root_objectid;
generation = fid->gen;
return btrfs_get_dentry(sb, objectid, root_objectid, generation);
return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
}
static struct dentry *btrfs_get_parent(struct dentry *child)
{
struct inode *dir = child->d_inode;
static struct dentry *dentry;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_key key;
struct btrfs_path *path;
struct extent_buffer *leaf;
int slot;
u64 objectid;
struct btrfs_root_ref *ref;
struct btrfs_key key;
struct btrfs_key found_key;
int ret;
path = btrfs_alloc_path();
key.objectid = dir->i_ino;
btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
key.offset = (u64)-1;
if (dir->i_ino == BTRFS_FIRST_FREE_OBJECTID) {
key.objectid = root->root_key.objectid;
key.type = BTRFS_ROOT_BACKREF_KEY;
key.offset = (u64)-1;
root = root->fs_info->tree_root;
} else {
key.objectid = dir->i_ino;
key.type = BTRFS_INODE_REF_KEY;
key.offset = (u64)-1;
}
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0) {
/* Error */
btrfs_free_path(path);
return ERR_PTR(ret);
}
leaf = path->nodes[0];
slot = path->slots[0];
if (ret) {
/* btrfs_search_slot() returns the slot where we'd want to
insert a backref for parent inode #0xFFFFFFFFFFFFFFFF.
The _real_ backref, telling us what the parent inode
_actually_ is, will be in the slot _before_ the one
that btrfs_search_slot() returns. */
if (!slot) {
/* Unless there is _no_ key in the tree before... */
btrfs_free_path(path);
return ERR_PTR(-EIO);
}
slot--;
if (ret < 0)
goto fail;
BUG_ON(ret == 0);
if (path->slots[0] == 0) {
ret = -ENOENT;
goto fail;
}
btrfs_item_key_to_cpu(leaf, &key, slot);
path->slots[0]--;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != key.objectid || found_key.type != key.type) {
ret = -ENOENT;
goto fail;
}
if (found_key.type == BTRFS_ROOT_BACKREF_KEY) {
ref = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_root_ref);
key.objectid = btrfs_root_ref_dirid(leaf, ref);
} else {
key.objectid = found_key.offset;
}
btrfs_free_path(path);
if (key.objectid != dir->i_ino || key.type != BTRFS_INODE_REF_KEY)
return ERR_PTR(-EINVAL);
if (found_key.type == BTRFS_ROOT_BACKREF_KEY) {
return btrfs_get_dentry(root->fs_info->sb, key.objectid,
found_key.offset, 0, 0);
}
objectid = key.offset;
/* If we are already at the root of a subvol, return the real root */
if (objectid == dir->i_ino)
return dget(dir->i_sb->s_root);
/* Build a new key for the inode item */
key.objectid = objectid;
btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
return d_obtain_alias(btrfs_iget(root->fs_info->sb, &key, root));
dentry = d_obtain_alias(btrfs_iget(root->fs_info->sb, &key, root));
if (!IS_ERR(dentry))
dentry->d_op = &btrfs_dentry_operations;
return dentry;
fail:
btrfs_free_path(path);
return ERR_PTR(ret);
}
const struct export_operations btrfs_export_ops = {

21
fs/btrfs/extent-tree.c
View file

@ -5463,9 +5463,24 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref)
ret = btrfs_del_root(trans, tree_root, &root->root_key);
BUG_ON(ret);
free_extent_buffer(root->node);
free_extent_buffer(root->commit_root);
kfree(root);
if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
ret = btrfs_find_last_root(tree_root, root->root_key.objectid,
NULL, NULL);
BUG_ON(ret < 0);
if (ret > 0) {
ret = btrfs_del_orphan_item(trans, tree_root,
root->root_key.objectid);
BUG_ON(ret);
}
}
if (root->in_radix) {
btrfs_free_fs_root(tree_root->fs_info, root);
} else {
free_extent_buffer(root->node);
free_extent_buffer(root->commit_root);
kfree(root);
}
out:
btrfs_end_transaction(trans, tree_root);
kfree(wc);

134
fs/btrfs/inode.c
View file

@ -3089,6 +3089,11 @@ void btrfs_delete_inode(struct inode *inode)
}
btrfs_wait_ordered_range(inode, 0, (u64)-1);
if (inode->i_nlink > 0) {
BUG_ON(btrfs_root_refs(&root->root_item) != 0);
goto no_delete;
}
btrfs_i_size_write(inode, 0);
trans = btrfs_join_transaction(root, 1);
@ -3225,11 +3230,13 @@ static void inode_tree_add(struct inode *inode)
struct btrfs_inode *entry;
struct rb_node **p;
struct rb_node *parent;
again:
p = &root->inode_tree.rb_node;
parent = NULL;
if (hlist_unhashed(&inode->i_hash))
return;
spin_lock(&root->inode_lock);
while (*p) {
parent = *p;
@ -3256,13 +3263,87 @@ static void inode_tree_add(struct inode *inode)
static void inode_tree_del(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
int empty = 0;
spin_lock(&root->inode_lock);
if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
empty = RB_EMPTY_ROOT(&root->inode_tree);
}
spin_unlock(&root->inode_lock);
if (empty && btrfs_root_refs(&root->root_item) == 0) {
synchronize_srcu(&root->fs_info->subvol_srcu);
spin_lock(&root->inode_lock);
empty = RB_EMPTY_ROOT(&root->inode_tree);
spin_unlock(&root->inode_lock);
if (empty)
btrfs_add_dead_root(root);
}
}
int btrfs_invalidate_inodes(struct btrfs_root *root)
{
struct rb_node *node;
struct rb_node *prev;
struct btrfs_inode *entry;
struct inode *inode;
u64 objectid = 0;
WARN_ON(btrfs_root_refs(&root->root_item) != 0);
spin_lock(&root->inode_lock);
again:
node = root->inode_tree.rb_node;
prev = NULL;
while (node) {
prev = node;
entry = rb_entry(node, struct btrfs_inode, rb_node);
if (objectid < entry->vfs_inode.i_ino)
node = node->rb_left;
else if (objectid > entry->vfs_inode.i_ino)
node = node->rb_right;
else
break;
}
if (!node) {
while (prev) {
entry = rb_entry(prev, struct btrfs_inode, rb_node);
if (objectid <= entry->vfs_inode.i_ino) {
node = prev;
break;
}
prev = rb_next(prev);
}
}
while (node) {
entry = rb_entry(node, struct btrfs_inode, rb_node);
objectid = entry->vfs_inode.i_ino + 1;
inode = igrab(&entry->vfs_inode);
if (inode) {
spin_unlock(&root->inode_lock);
if (atomic_read(&inode->i_count) > 1)
d_prune_aliases(inode);
/*
* btrfs_drop_inode will remove it from
* the inode cache when its usage count
* hits zero.
*/
iput(inode);
cond_resched();
spin_lock(&root->inode_lock);
goto again;
}
if (cond_resched_lock(&root->inode_lock))
goto again;
node = rb_next(node);
}
spin_unlock(&root->inode_lock);
return 0;
}
static noinline void init_btrfs_i(struct inode *inode)
@ -3379,8 +3460,11 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_root *sub_root = root;
struct btrfs_key location;
int index;
int ret;
dentry->d_op = &btrfs_dentry_operations;
if (dentry->d_name.len > BTRFS_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
@ -3399,6 +3483,7 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
index = srcu_read_lock(&root->fs_info->subvol_srcu);
ret = fixup_tree_root_location(root, dir, dentry,
&location, &sub_root);
if (ret < 0) {
@ -3409,9 +3494,24 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
} else {
inode = btrfs_iget(dir->i_sb, &location, sub_root);
}
srcu_read_unlock(&root->fs_info->subvol_srcu, index);
return inode;
}
static int btrfs_dentry_delete(struct dentry *dentry)
{
struct btrfs_root *root;
if (!dentry->d_inode)
return 0;
root = BTRFS_I(dentry->d_inode)->root;
if (btrfs_root_refs(&root->root_item) == 0)
return 1;
return 0;
}
static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nd)
{
@ -4773,11 +4873,11 @@ static void btrfs_truncate(struct inode *inode)
* create a new subvolume directory/inode (helper for the ioctl).
*/
int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
struct btrfs_root *new_root, struct dentry *dentry,
struct btrfs_root *new_root,
u64 new_dirid, u64 alloc_hint)
{
struct inode *inode;
int error;
int err;
u64 index = 0;
inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, new_dirid,
@ -4790,11 +4890,10 @@ int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
inode->i_nlink = 1;
btrfs_i_size_write(inode, 0);
error = btrfs_update_inode(trans, new_root, inode);
if (error)
return error;
err = btrfs_update_inode(trans, new_root, inode);
BUG_ON(err);
d_instantiate(dentry, inode);
iput(inode);
return 0;
}
@ -4872,6 +4971,16 @@ void btrfs_destroy_inode(struct inode *inode)
kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
}
void btrfs_drop_inode(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
if (inode->i_nlink > 0 && btrfs_root_refs(&root->root_item) == 0)
generic_delete_inode(inode);
else
generic_drop_inode(inode);
}
static void init_once(void *foo)
{
struct btrfs_inode *ei = (struct btrfs_inode *) foo;
@ -4973,6 +5082,10 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
filemap_flush(old_inode->i_mapping);
/* close the racy window with snapshot create/destroy ioctl */
if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
down_read(&root->fs_info->subvol_sem);
trans = btrfs_start_transaction(root, 1);
if (dest != root)
@ -5062,6 +5175,8 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
btrfs_end_transaction_throttle(trans, root);
if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
up_read(&root->fs_info->subvol_sem);
return ret;
}
@ -5420,6 +5535,7 @@ static struct inode_operations btrfs_dir_ro_inode_operations = {
.lookup = btrfs_lookup,
.permission = btrfs_permission,
};
static struct file_operations btrfs_dir_file_operations = {
.llseek = generic_file_llseek,
.read = generic_read_dir,
@ -5506,3 +5622,7 @@ static struct inode_operations btrfs_symlink_inode_operations = {
.listxattr = btrfs_listxattr,
.removexattr = btrfs_removexattr,
};
struct dentry_operations btrfs_dentry_operations = {
.d_delete = btrfs_dentry_delete,
};

320
fs/btrfs/ioctl.c
View file

@ -230,8 +230,8 @@ static noinline int create_subvol(struct btrfs_root *root,
struct btrfs_root_item root_item;
struct btrfs_inode_item *inode_item;
struct extent_buffer *leaf;
struct btrfs_root *new_root = root;
struct inode *dir;
struct btrfs_root *new_root;
struct inode *dir = dentry->d_parent->d_inode;
int ret;
int err;
u64 objectid;
@ -241,7 +241,7 @@ static noinline int create_subvol(struct btrfs_root *root,
ret = btrfs_check_metadata_free_space(root);
if (ret)
goto fail_commit;
return ret;
trans = btrfs_start_transaction(root, 1);
BUG_ON(!trans);
@ -304,11 +304,17 @@ static noinline int create_subvol(struct btrfs_root *root,
if (ret)
goto fail;
key.offset = (u64)-1;
new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
BUG_ON(IS_ERR(new_root));
btrfs_record_root_in_trans(trans, new_root);
ret = btrfs_create_subvol_root(trans, new_root, new_dirid,
BTRFS_I(dir)->block_group);
/*
* insert the directory item
*/
key.offset = (u64)-1;
dir = dentry->d_parent->d_inode;
ret = btrfs_set_inode_index(dir, &index);
BUG_ON(ret);
@ -325,30 +331,15 @@ static noinline int create_subvol(struct btrfs_root *root,
ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
objectid, root->root_key.objectid,
dir->i_ino, index, name, namelen);
BUG_ON(ret);
ret = btrfs_commit_transaction(trans, root);
if (ret)
goto fail_commit;
new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
BUG_ON(!new_root);
trans = btrfs_start_transaction(new_root, 1);
BUG_ON(!trans);
ret = btrfs_create_subvol_root(trans, new_root, dentry, new_dirid,
BTRFS_I(dir)->block_group);
if (ret)
goto fail;
d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
fail:
nr = trans->blocks_used;
err = btrfs_commit_transaction(trans, new_root);
err = btrfs_commit_transaction(trans, root);
if (err && !ret)
ret = err;
fail_commit:
btrfs_btree_balance_dirty(root, nr);
return ret;
}
@ -409,14 +400,15 @@ static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
* sys_mkdirat and vfs_mkdir, but we only do a single component lookup
* inside this filesystem so it's quite a bit simpler.
*/
static noinline int btrfs_mksubvol(struct path *parent, char *name,
int mode, int namelen,
static noinline int btrfs_mksubvol(struct path *parent,
char *name, int namelen,
struct btrfs_root *snap_src)
{
struct inode *dir = parent->dentry->d_inode;
struct dentry *dentry;
int error;
mutex_lock_nested(&parent->dentry->d_inode->i_mutex, I_MUTEX_PARENT);
mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
dentry = lookup_one_len(name, parent->dentry, namelen);
error = PTR_ERR(dentry);
@ -427,99 +419,39 @@ static noinline int btrfs_mksubvol(struct path *parent, char *name,
if (dentry->d_inode)
goto out_dput;
if (!IS_POSIXACL(parent->dentry->d_inode))
mode &= ~current_umask();
error = mnt_want_write(parent->mnt);
if (error)
goto out_dput;
error = btrfs_may_create(parent->dentry->d_inode, dentry);
error = btrfs_may_create(dir, dentry);
if (error)
goto out_drop_write;
/*
* Actually perform the low-level subvolume creation after all
* this VFS fuzz.
*
* Eventually we want to pass in an inode under which we create this
* subvolume, but for now all are under the filesystem root.
*
* Also we should pass on the mode eventually to allow creating new
* subvolume with specific mode bits.
*/
down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
goto out_up_read;
if (snap_src) {
struct dentry *dir = dentry->d_parent;
struct dentry *test = dir->d_parent;
struct btrfs_path *path = btrfs_alloc_path();
int ret;
u64 test_oid;
u64 parent_oid = BTRFS_I(dir->d_inode)->root->root_key.objectid;
test_oid = snap_src->root_key.objectid;
ret = btrfs_find_root_ref(snap_src->fs_info->tree_root,
path, parent_oid, test_oid);
if (ret == 0)
goto create;
btrfs_release_path(snap_src->fs_info->tree_root, path);
/* we need to make sure we aren't creating a directory loop
* by taking a snapshot of something that has our current
* subvol in its directory tree. So, this loops through
* the dentries and checks the forward refs for each subvolume
* to see if is references the subvolume where we are
* placing this new snapshot.
*/
while (1) {
if (!test ||
dir == snap_src->fs_info->sb->s_root ||
test == snap_src->fs_info->sb->s_root ||
test->d_inode->i_sb != snap_src->fs_info->sb) {
break;
}
if (S_ISLNK(test->d_inode->i_mode)) {
printk(KERN_INFO "Btrfs symlink in snapshot "
"path, failed\n");
error = -EMLINK;
btrfs_free_path(path);
goto out_drop_write;
}
test_oid =
BTRFS_I(test->d_inode)->root->root_key.objectid;
ret = btrfs_find_root_ref(snap_src->fs_info->tree_root,
path, test_oid, parent_oid);
if (ret == 0) {
printk(KERN_INFO "Btrfs snapshot creation "
"failed, looping\n");
error = -EMLINK;
btrfs_free_path(path);
goto out_drop_write;
}
btrfs_release_path(snap_src->fs_info->tree_root, path);
test = test->d_parent;
}
create:
btrfs_free_path(path);
error = create_snapshot(snap_src, dentry, name, namelen);
error = create_snapshot(snap_src, dentry,
name, namelen);
} else {
error = create_subvol(BTRFS_I(parent->dentry->d_inode)->root,
dentry, name, namelen);
error = create_subvol(BTRFS_I(dir)->root, dentry,
name, namelen);
}
if (error)
goto out_drop_write;
fsnotify_mkdir(parent->dentry->d_inode, dentry);
if (!error)
fsnotify_mkdir(dir, dentry);
out_up_read:
up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
out_drop_write:
mnt_drop_write(parent->mnt);
out_dput:
dput(dentry);
out_unlock:
mutex_unlock(&parent->dentry->d_inode->i_mutex);
mutex_unlock(&dir->i_mutex);
return error;
}
static int btrfs_defrag_file(struct file *file)
{
struct inode *inode = fdentry(file)->d_inode;
@ -597,7 +529,8 @@ static int btrfs_defrag_file(struct file *file)
return 0;
}
static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
void __user *arg)
{
u64 new_size;
u64 old_size;
@ -706,10 +639,7 @@ static noinline int btrfs_ioctl_snap_create(struct file *file,
{
struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
struct btrfs_ioctl_vol_args *vol_args;
struct btrfs_dir_item *di;
struct btrfs_path *path;
struct file *src_file;
u64 root_dirid;
int namelen;
int ret = 0;
@ -727,32 +657,9 @@ static noinline int btrfs_ioctl_snap_create(struct file *file,
goto out;
}
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
path, root_dirid,
vol_args->name, namelen, 0);
btrfs_free_path(path);
if (di && !IS_ERR(di)) {
ret = -EEXIST;
goto out;
}
if (IS_ERR(di)) {
ret = PTR_ERR(di);
goto out;
}
if (subvol) {
ret = btrfs_mksubvol(&file->f_path, vol_args->name,
file->f_path.dentry->d_inode->i_mode,
namelen, NULL);
ret = btrfs_mksubvol(&file->f_path, vol_args->name, namelen,
NULL);
} else {
struct inode *src_inode;
src_file = fget(vol_args->fd);
@ -769,17 +676,156 @@ static noinline int btrfs_ioctl_snap_create(struct file *file,
fput(src_file);
goto out;
}
ret = btrfs_mksubvol(&file->f_path, vol_args->name,
file->f_path.dentry->d_inode->i_mode,
namelen, BTRFS_I(src_inode)->root);
ret = btrfs_mksubvol(&file->f_path, vol_args->name, namelen,
BTRFS_I(src_inode)->root);
fput(src_file);
}
out:
kfree(vol_args);
return ret;
}
/*
* helper to check if the subvolume references other subvolumes
*/
static noinline int may_destroy_subvol(struct btrfs_root *root)
{
struct btrfs_path *path;
struct btrfs_key key;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = root->root_key.objectid;
key.type = BTRFS_ROOT_REF_KEY;
key.offset = (u64)-1;
ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
&key, path, 0, 0);
if (ret < 0)
goto out;
BUG_ON(ret == 0);
ret = 0;
if (path->slots[0] > 0) {
path->slots[0]--;
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
if (key.objectid == root->root_key.objectid &&
key.type == BTRFS_ROOT_REF_KEY)
ret = -ENOTEMPTY;
}
out:
btrfs_free_path(path);
return ret;
}
static noinline int btrfs_ioctl_snap_destroy(struct file *file,
void __user *arg)
{
struct dentry *parent = fdentry(file);
struct dentry *dentry;
struct inode *dir = parent->d_inode;
struct inode *inode;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_root *dest = NULL;
struct btrfs_ioctl_vol_args *vol_args;
struct btrfs_trans_handle *trans;
int namelen;
int ret;
int err = 0;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args))
return PTR_ERR(vol_args);
vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
namelen = strlen(vol_args->name);
if (strchr(vol_args->name, '/') ||
strncmp(vol_args->name, "..", namelen) == 0) {
err = -EINVAL;
goto out;
}
err = mnt_want_write(file->f_path.mnt);
if (err)
goto out;
mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
dentry = lookup_one_len(vol_args->name, parent, namelen);
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
goto out_unlock_dir;
}
if (!dentry->d_inode) {
err = -ENOENT;
goto out_dput;
}
inode = dentry->d_inode;
if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) {
err = -EINVAL;
goto out_dput;
}
dest = BTRFS_I(inode)->root;
mutex_lock(&inode->i_mutex);
err = d_invalidate(dentry);
if (err)
goto out_unlock;
down_write(&root->fs_info->subvol_sem);
err = may_destroy_subvol(dest);
if (err)
goto out_up_write;
trans = btrfs_start_transaction(root, 1);
ret = btrfs_unlink_subvol(trans, root, dir,
dest->root_key.objectid,
dentry->d_name.name,
dentry->d_name.len);
BUG_ON(ret);
btrfs_record_root_in_trans(trans, dest);
memset(&dest->root_item.drop_progress, 0,
sizeof(dest->root_item.drop_progress));
dest->root_item.drop_level = 0;
btrfs_set_root_refs(&dest->root_item, 0);
ret = btrfs_insert_orphan_item(trans,
root->fs_info->tree_root,
dest->root_key.objectid);
BUG_ON(ret);
ret = btrfs_commit_transaction(trans, root);
BUG_ON(ret);
inode->i_flags |= S_DEAD;
out_up_write:
up_write(&root->fs_info->subvol_sem);
out_unlock:
mutex_unlock(&inode->i_mutex);
if (!err) {
btrfs_invalidate_inodes(dest);
d_delete(dentry);
}
out_dput:
dput(dentry);
out_unlock_dir:
mutex_unlock(&dir->i_mutex);
mnt_drop_write(file->f_path.mnt);
out:
kfree(vol_args);
return err;
}
static int btrfs_ioctl_defrag(struct file *file)
{
struct inode *inode = fdentry(file)->d_inode;
@ -853,8 +899,8 @@ static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
return ret;
}
static long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
u64 off, u64 olen, u64 destoff)
static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
u64 off, u64 olen, u64 destoff)
{
struct inode *inode = fdentry(file)->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
@ -1246,6 +1292,8 @@ long btrfs_ioctl(struct file *file, unsigned int
return btrfs_ioctl_snap_create(file, argp, 0);
case BTRFS_IOC_SUBVOL_CREATE:
return btrfs_ioctl_snap_create(file, argp, 1);
case BTRFS_IOC_SNAP_DESTROY:
return btrfs_ioctl_snap_destroy(file, argp);
case BTRFS_IOC_DEFRAG:
return btrfs_ioctl_defrag(file);
case BTRFS_IOC_RESIZE:

3
fs/btrfs/ioctl.h
View file

@ -65,5 +65,6 @@ struct btrfs_ioctl_clone_range_args {
#define BTRFS_IOC_SUBVOL_CREATE _IOW(BTRFS_IOCTL_MAGIC, 14, \
struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_SNAP_DESTROY _IOW(BTRFS_IOCTL_MAGIC, 15, \
struct btrfs_ioctl_vol_args)
#endif

41
fs/btrfs/relocation.c
View file

@ -3203,6 +3203,7 @@ static int check_extent_flags(u64 flags)
return 0;
}
static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
{
struct rb_root blocks = RB_ROOT;
@ -3220,6 +3221,9 @@ static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
if (!path)
return -ENOMEM;
rc->extents_found = 0;
rc->extents_skipped = 0;
rc->search_start = rc->block_group->key.objectid;
clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY,
GFP_NOFS);
@ -3475,14 +3479,15 @@ int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start)
btrfs_wait_ordered_extents(fs_info->tree_root, 0);
while (1) {
mutex_lock(&fs_info->cleaner_mutex);
btrfs_clean_old_snapshots(fs_info->tree_root);
mutex_unlock(&fs_info->cleaner_mutex);
rc->extents_found = 0;
rc->extents_skipped = 0;
mutex_lock(&fs_info->cleaner_mutex);
btrfs_clean_old_snapshots(fs_info->tree_root);
ret = relocate_block_group(rc);
mutex_unlock(&fs_info->cleaner_mutex);
if (ret < 0) {
err = ret;
break;
@ -3530,6 +3535,26 @@ int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start)
return err;
}
static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
{
struct btrfs_trans_handle *trans;
int ret;
trans = btrfs_start_transaction(root->fs_info->tree_root, 1);
memset(&root->root_item.drop_progress, 0,
sizeof(root->root_item.drop_progress));
root->root_item.drop_level = 0;
btrfs_set_root_refs(&root->root_item, 0);
ret = btrfs_update_root(trans, root->fs_info->tree_root,
&root->root_key, &root->root_item);
BUG_ON(ret);
ret = btrfs_end_transaction(trans, root->fs_info->tree_root);
BUG_ON(ret);
return 0;
}
/*
* recover relocation interrupted by system crash.
*
@ -3589,8 +3614,12 @@ int btrfs_recover_relocation(struct btrfs_root *root)
fs_root = read_fs_root(root->fs_info,
reloc_root->root_key.offset);
if (IS_ERR(fs_root)) {
err = PTR_ERR(fs_root);
goto out;
ret = PTR_ERR(fs_root);
if (ret != -ENOENT) {
err = ret;
goto out;
}
mark_garbage_root(reloc_root);
}
}

75
fs/btrfs/root-tree.c
View file

@ -94,17 +94,23 @@ int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
goto out;
BUG_ON(ret == 0);
l = path->nodes[0];
BUG_ON(path->slots[0] == 0);
slot = path->slots[0] - 1;
btrfs_item_key_to_cpu(l, &found_key, slot);
if (found_key.objectid != objectid) {
if (path->slots[0] == 0) {
ret = 1;
goto out;
}
read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot),
sizeof(*item));
memcpy(key, &found_key, sizeof(found_key));
l = path->nodes[0];
slot = path->slots[0] - 1;
btrfs_item_key_to_cpu(l, &found_key, slot);
if (found_key.objectid != objectid ||
found_key.type != BTRFS_ROOT_ITEM_KEY) {
ret = 1;
goto out;
}
if (item)
read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot),
sizeof(*item));
if (key)
memcpy(key, &found_key, sizeof(found_key));
ret = 0;
out:
btrfs_free_path(path);
@ -249,6 +255,59 @@ int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid)
return ret;
}
int btrfs_find_orphan_roots(struct btrfs_root *tree_root)
{
struct extent_buffer *leaf;
struct btrfs_path *path;
struct btrfs_key key;
int err = 0;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = BTRFS_ORPHAN_OBJECTID;
key.type = BTRFS_ORPHAN_ITEM_KEY;
key.offset = 0;
while (1) {
ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
if (ret < 0) {
err = ret;
break;
}
leaf = path->nodes[0];
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(tree_root, path);
if (ret < 0)
err = ret;
if (ret != 0)
break;
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
btrfs_release_path(tree_root, path);
if (key.objectid != BTRFS_ORPHAN_OBJECTID ||
key.type != BTRFS_ORPHAN_ITEM_KEY)
break;
ret = btrfs_find_dead_roots(tree_root, key.offset);
if (ret) {
err = ret;
break;
}
key.offset++;
}
btrfs_free_path(path);
return err;
}
/* drop the root item for 'key' from 'root' */
int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct btrfs_key *key)

1
fs/btrfs/super.c
View file

@ -676,6 +676,7 @@ static int btrfs_unfreeze(struct super_block *sb)
}
static struct super_operations btrfs_super_ops = {
.drop_inode = btrfs_drop_inode,
.delete_inode = btrfs_delete_inode,
.put_super = btrfs_put_super,
.sync_fs = btrfs_sync_fs,

10
fs/btrfs/transaction.c
View file

@ -104,7 +104,6 @@ static noinline int record_root_in_trans(struct btrfs_trans_handle *trans,
{
if (root->ref_cows && root->last_trans < trans->transid) {
WARN_ON(root == root->fs_info->extent_root);
WARN_ON(root->root_item.refs == 0);
WARN_ON(root->commit_root != root->node);
radix_tree_tag_set(&root->fs_info->fs_roots_radix,
@ -1078,8 +1077,13 @@ int btrfs_clean_old_snapshots(struct btrfs_root *root)
while (!list_empty(&list)) {
root = list_entry(list.next, struct btrfs_root, root_list);
list_del_init(&root->root_list);
btrfs_drop_snapshot(root, 0);
list_del(&root->root_list);
if (btrfs_header_backref_rev(root->node) <
BTRFS_MIXED_BACKREF_REV)
btrfs_drop_snapshot(root, 0);
else
btrfs_drop_snapshot(root, 1);
}
return 0;
}

13
fs/btrfs/tree-log.c
View file

@ -2841,7 +2841,7 @@ static noinline int check_parent_dirs_for_sync(struct btrfs_trans_handle *trans,
if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
break;
if (parent == sb->s_root)
if (IS_ROOT(parent))
break;
parent = parent->d_parent;
@ -2880,6 +2880,12 @@ int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
goto end_no_trans;
}
if (root != BTRFS_I(inode)->root ||
btrfs_root_refs(&root->root_item) == 0) {
ret = 1;
goto end_no_trans;
}
ret = check_parent_dirs_for_sync(trans, inode, parent,
sb, last_committed);
if (ret)
@ -2907,12 +2913,15 @@ int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
break;
inode = parent->d_inode;
if (root != BTRFS_I(inode)->root)
break;
if (BTRFS_I(inode)->generation >
root->fs_info->last_trans_committed) {
ret = btrfs_log_inode(trans, root, inode, inode_only);
BUG_ON(ret);
}
if (parent == sb->s_root)
if (IS_ROOT(parent))
break;
parent = parent->d_parent;