static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
u64 root_objectid, u32 generation)
{
struct btrfs_root *root;
struct inode *inode;
struct btrfs_key key;
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);
key.objectid = objectid;
btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
key.offset = 0;
inode = btrfs_iget(sb, &key, root, NULL);
if (IS_ERR(inode))
return (void *)inode;
if (generation != inode->i_generation) {
iput(inode);
return ERR_PTR(-ESTALE);
}
return d_obtain_alias(inode);
}
static struct dentry *btrfs_get_parent(struct dentry *child)
{
struct inode *dir = child->d_inode;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_key key;
struct btrfs_path *path;
struct extent_buffer *leaf;
int slot;
u64 objectid;
int ret;
path = btrfs_alloc_path();
key.objectid = dir->i_ino;
btrfs_set_key_type(&key, 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--;
}
btrfs_item_key_to_cpu(leaf, &key, slot);
btrfs_free_path(path);
if (key.objectid != dir->i_ino || key.type != BTRFS_INODE_REF_KEY)
return ERR_PTR(-EINVAL);
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.offset = 0;
return d_obtain_alias(btrfs_iget(root->fs_info->sb, &key, root, NULL));
}
static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
u64 root_objectid, u32 generation,
int check_generation)
{
struct btrfs_fs_info *fs_info = btrfs_sb(sb);
struct btrfs_root *root;
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;
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, NULL);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto fail;
}
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);
fail:
srcu_read_unlock(&fs_info->subvol_srcu, index);
return ERR_PTR(err);
}
/*
* run through the list of inodes in the FS that need
* defragging
*/
int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info)
{
struct inode_defrag *defrag;
struct btrfs_root *inode_root;
struct inode *inode;
struct rb_node *n;
struct btrfs_key key;
struct btrfs_ioctl_defrag_range_args range;
u64 first_ino = 0;
u64 root_objectid = 0;
int num_defrag;
int defrag_batch = 1024;
memset(&range, 0, sizeof(range));
range.len = (u64)-1;
atomic_inc(&fs_info->defrag_running);
spin_lock(&fs_info->defrag_inodes_lock);
while(1) {
n = NULL;
/* find an inode to defrag */
defrag = btrfs_find_defrag_inode(fs_info, root_objectid,
first_ino, &n);
if (!defrag) {
if (n) {
defrag = rb_entry(n, struct inode_defrag,
rb_node);
} else if (root_objectid || first_ino) {
root_objectid = 0;
first_ino = 0;
continue;
} else {
break;
}
}
/* remove it from the rbtree */
first_ino = defrag->ino + 1;
root_objectid = defrag->root;
rb_erase(&defrag->rb_node, &fs_info->defrag_inodes);
if (btrfs_fs_closing(fs_info))
goto next_free;
spin_unlock(&fs_info->defrag_inodes_lock);
/* get the inode */
key.objectid = defrag->root;
btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
key.offset = (u64)-1;
inode_root = btrfs_read_fs_root_no_name(fs_info, &key);
if (IS_ERR(inode_root))
goto next;
key.objectid = defrag->ino;
btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
key.offset = 0;
inode = btrfs_iget(fs_info->sb, &key, inode_root, NULL);
if (IS_ERR(inode))
goto next;
/* do a chunk of defrag */
clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
range.start = defrag->last_offset;
num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid,
defrag_batch);
/*
* if we filled the whole defrag batch, there
* must be more work to do. Queue this defrag
* again
*/
if (num_defrag == defrag_batch) {
defrag->last_offset = range.start;
__btrfs_add_inode_defrag(inode, defrag);
/*
* we don't want to kfree defrag, we added it back to
* the rbtree
*/
defrag = NULL;
} else if (defrag->last_offset && !defrag->cycled) {
/*
* we didn't fill our defrag batch, but
* we didn't start at zero. Make sure we loop
* around to the start of the file.
*/
defrag->last_offset = 0;
defrag->cycled = 1;
__btrfs_add_inode_defrag(inode, defrag);
defrag = NULL;
}
iput(inode);
next:
spin_lock(&fs_info->defrag_inodes_lock);
next_free:
kfree(defrag);
}