Btrfs: Create orphan inode records to prevent lost files after a crash
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 2d885354..0c9ec8a 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -78,6 +78,8 @@
[S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
};
+static void btrfs_truncate(struct inode *inode);
+
int btrfs_check_free_space(struct btrfs_root *root, u64 num_required,
int for_del)
{
@@ -826,6 +828,190 @@
return -EIO;
}
+/*
+ * This creates an orphan entry for the given inode in case something goes
+ * wrong in the middle of an unlink/truncate.
+ */
+int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret = 0;
+
+ spin_lock(&root->orphan_lock);
+
+ /* already on the orphan list, we're good */
+ if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
+ spin_unlock(&root->orphan_lock);
+ return 0;
+ }
+
+ list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
+
+ spin_unlock(&root->orphan_lock);
+
+ /*
+ * insert an orphan item to track this unlinked/truncated file
+ */
+ ret = btrfs_insert_orphan_item(trans, root, inode->i_ino);
+
+ return ret;
+}
+
+/*
+ * We have done the truncate/delete so we can go ahead and remove the orphan
+ * item for this particular inode.
+ */
+int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret = 0;
+
+ spin_lock(&root->orphan_lock);
+
+ if (list_empty(&BTRFS_I(inode)->i_orphan)) {
+ spin_unlock(&root->orphan_lock);
+ return 0;
+ }
+
+ list_del_init(&BTRFS_I(inode)->i_orphan);
+ if (!trans) {
+ spin_unlock(&root->orphan_lock);
+ return 0;
+ }
+
+ spin_unlock(&root->orphan_lock);
+
+ ret = btrfs_del_orphan_item(trans, root, inode->i_ino);
+
+ return ret;
+}
+
+/*
+ * this cleans up any orphans that may be left on the list from the last use
+ * of this root.
+ */
+void btrfs_orphan_cleanup(struct btrfs_root *root)
+{
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_item *item;
+ struct btrfs_key key, found_key;
+ struct btrfs_trans_handle *trans;
+ struct inode *inode;
+ int ret = 0, nr_unlink = 0, nr_truncate = 0;
+
+ /* don't do orphan cleanup if the fs is readonly. */
+ if (root->inode->i_sb->s_flags & MS_RDONLY)
+ return;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return;
+ path->reada = -1;
+
+ key.objectid = BTRFS_ORPHAN_OBJECTID;
+ btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
+ key.offset = (u64)-1;
+
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, root->inode);
+
+ while (1) {
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0) {
+ printk(KERN_ERR "Error searching slot for orphan: %d"
+ "\n", ret);
+ break;
+ }
+
+ /*
+ * if ret == 0 means we found what we were searching for, which
+ * is weird, but possible, so only screw with path if we didnt
+ * find the key and see if we have stuff that matches
+ */
+ if (ret > 0) {
+ if (path->slots[0] == 0)
+ break;
+ path->slots[0]--;
+ }
+
+ /* pull out the item */
+ leaf = path->nodes[0];
+ item = btrfs_item_nr(leaf, path->slots[0]);
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+ /* make sure the item matches what we want */
+ if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
+ break;
+ if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
+ break;
+
+ /* release the path since we're done with it */
+ btrfs_release_path(root, path);
+
+ /*
+ * this is where we are basically btrfs_lookup, without the
+ * crossing root thing. we store the inode number in the
+ * offset of the orphan item.
+ */
+ inode = btrfs_iget_locked(root->inode->i_sb,
+ found_key.offset, root);
+ if (!inode)
+ break;
+
+ if (inode->i_state & I_NEW) {
+ BTRFS_I(inode)->root = root;
+
+ /* have to set the location manually */
+ BTRFS_I(inode)->location.objectid = inode->i_ino;
+ BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
+ BTRFS_I(inode)->location.offset = 0;
+
+ btrfs_read_locked_inode(inode);
+ unlock_new_inode(inode);
+ }
+
+ /*
+ * add this inode to the orphan list so btrfs_orphan_del does
+ * the proper thing when we hit it
+ */
+ spin_lock(&root->orphan_lock);
+ list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
+ spin_unlock(&root->orphan_lock);
+
+ /*
+ * if this is a bad inode, means we actually succeeded in
+ * removing the inode, but not the orphan record, which means
+ * we need to manually delete the orphan since iput will just
+ * do a destroy_inode
+ */
+ if (is_bad_inode(inode)) {
+ btrfs_orphan_del(trans, inode);
+ iput(inode);
+ continue;
+ }
+
+ /* if we have links, this was a truncate, lets do that */
+ if (inode->i_nlink) {
+ nr_truncate++;
+ btrfs_truncate(inode);
+ } else {
+ nr_unlink++;
+ }
+
+ /* this will do delete_inode and everything for us */
+ iput(inode);
+ }
+
+ if (nr_unlink)
+ printk(KERN_INFO "btrfs: unlinked %d orphans\n", nr_unlink);
+ if (nr_truncate)
+ printk(KERN_INFO "btrfs: truncated %d orphans\n", nr_truncate);
+
+ btrfs_free_path(path);
+ btrfs_end_transaction(trans, root);
+}
+
void btrfs_read_locked_inode(struct inode *inode)
{
struct btrfs_path *path;
@@ -1067,6 +1253,7 @@
{
struct btrfs_root *root;
struct btrfs_trans_handle *trans;
+ struct inode *inode = dentry->d_inode;
int ret;
unsigned long nr = 0;
@@ -1080,6 +1267,10 @@
btrfs_set_trans_block_group(trans, dir);
ret = btrfs_unlink_trans(trans, root, dir, dentry);
+
+ if (inode->i_nlink == 0)
+ ret = btrfs_orphan_add(trans, inode);
+
nr = trans->blocks_used;
btrfs_end_transaction_throttle(trans, root);
@@ -1108,12 +1299,17 @@
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, dir);
+ err = btrfs_orphan_add(trans, inode);
+ if (err)
+ goto fail_trans;
+
/* now the directory is empty */
err = btrfs_unlink_trans(trans, root, dir, dentry);
if (!err) {
btrfs_i_size_write(inode, 0);
}
+fail_trans:
nr = trans->blocks_used;
ret = btrfs_end_transaction_throttle(trans, root);
fail:
@@ -1131,6 +1327,9 @@
*
* csum items that cross the new i_size are truncated to the new size
* as well.
+ *
+ * min_type is the minimum key type to truncate down to. If set to 0, this
+ * will kill all the items on this inode, including the INODE_ITEM_KEY.
*/
static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
@@ -1495,6 +1694,7 @@
truncate_inode_pages(&inode->i_data, 0);
if (is_bad_inode(inode)) {
+ btrfs_orphan_del(NULL, inode);
goto no_delete;
}
btrfs_wait_ordered_range(inode, 0, (u64)-1);
@@ -1504,8 +1704,12 @@
btrfs_set_trans_block_group(trans, inode);
ret = btrfs_truncate_in_trans(trans, root, inode, 0);
- if (ret)
+ if (ret) {
+ btrfs_orphan_del(NULL, inode);
goto no_delete_lock;
+ }
+
+ btrfs_orphan_del(trans, inode);
nr = trans->blocks_used;
clear_inode(inode);
@@ -1688,7 +1892,7 @@
struct btrfs_root *root = bi->root;
struct btrfs_root *sub_root = root;
struct btrfs_key location;
- int ret;
+ int ret, do_orphan = 0;
if (dentry->d_name.len > BTRFS_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
@@ -1706,6 +1910,7 @@
return ERR_PTR(ret);
if (ret > 0)
return ERR_PTR(-ENOENT);
+
inode = btrfs_iget_locked(dir->i_sb, location.objectid,
sub_root);
if (!inode)
@@ -1715,6 +1920,7 @@
if (sub_root != root) {
igrab(inode);
sub_root->inode = inode;
+ do_orphan = 1;
}
BTRFS_I(inode)->root = sub_root;
memcpy(&BTRFS_I(inode)->location, &location,
@@ -1723,6 +1929,10 @@
unlock_new_inode(inode);
}
}
+
+ if (unlikely(do_orphan))
+ btrfs_orphan_cleanup(sub_root);
+
return d_splice_alias(inode, dentry);
}
@@ -2964,12 +3174,19 @@
btrfs_set_trans_block_group(trans, inode);
btrfs_i_size_write(inode, inode->i_size);
+ ret = btrfs_orphan_add(trans, inode);
+ if (ret)
+ goto out;
/* FIXME, add redo link to tree so we don't leak on crash */
ret = btrfs_truncate_in_trans(trans, root, inode,
BTRFS_EXTENT_DATA_KEY);
btrfs_update_inode(trans, root, inode);
- nr = trans->blocks_used;
+ ret = btrfs_orphan_del(trans, inode);
+ BUG_ON(ret);
+
+out:
+ nr = trans->blocks_used;
ret = btrfs_end_transaction_throttle(trans, root);
BUG_ON(ret);
btrfs_btree_balance_dirty(root, nr);
@@ -3046,6 +3263,7 @@
btrfs_ordered_inode_tree_init(&ei->ordered_tree);
ei->i_acl = BTRFS_ACL_NOT_CACHED;
ei->i_default_acl = BTRFS_ACL_NOT_CACHED;
+ INIT_LIST_HEAD(&ei->i_orphan);
return &ei->vfs_inode;
}
@@ -3062,6 +3280,14 @@
BTRFS_I(inode)->i_default_acl != BTRFS_ACL_NOT_CACHED)
posix_acl_release(BTRFS_I(inode)->i_default_acl);
+ spin_lock(&BTRFS_I(inode)->root->orphan_lock);
+ if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
+ printk(KERN_ERR "BTRFS: inode %lu: inode still on the orphan"
+ " list\n", inode->i_ino);
+ dump_stack();
+ }
+ spin_unlock(&BTRFS_I(inode)->root->orphan_lock);
+
while(1) {
ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
if (!ordered)
@@ -3202,6 +3428,11 @@
ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
if (ret)
goto out_fail;
+ if (new_inode->i_nlink == 0) {
+ ret = btrfs_orphan_add(trans, new_inode);
+ if (ret)
+ goto out_fail;
+ }
}
ret = btrfs_set_inode_index(new_dir, old_inode);
if (ret)