Btrfs: Integrate metadata reservation with start_transaction
authorYan, Zheng <zheng.yan@oracle.com>
Sun, 16 May 2010 14:48:46 +0000 (10:48 -0400)
committerChris Mason <chris.mason@oracle.com>
Tue, 25 May 2010 14:34:50 +0000 (10:34 -0400)
Besides simplify the code, this change makes sure all metadata
reservation for normal metadata operations are released after
committing transaction.

Changes since V1:

Add code that check if unlink and rmdir will free space.

Add ENOSPC handling for clone ioctl.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
15 files changed:
fs/btrfs/ctree.h
fs/btrfs/delayed-ref.c
fs/btrfs/delayed-ref.h
fs/btrfs/disk-io.c
fs/btrfs/extent-tree.c
fs/btrfs/file.c
fs/btrfs/inode-item.c
fs/btrfs/inode.c
fs/btrfs/ioctl.c
fs/btrfs/relocation.c
fs/btrfs/super.c
fs/btrfs/transaction.c
fs/btrfs/transaction.h
fs/btrfs/volumes.c
fs/btrfs/xattr.c

index 7d24796..e0aa9fb 100644 (file)
@@ -34,6 +34,7 @@
 
 struct btrfs_trans_handle;
 struct btrfs_transaction;
+struct btrfs_pending_snapshot;
 extern struct kmem_cache *btrfs_trans_handle_cachep;
 extern struct kmem_cache *btrfs_transaction_cachep;
 extern struct kmem_cache *btrfs_bit_radix_cachep;
@@ -970,6 +971,7 @@ struct btrfs_fs_info {
        int do_barriers;
        int closing;
        int log_root_recovering;
+       int enospc_unlink;
 
        u64 total_pinned;
 
@@ -1995,6 +1997,9 @@ void btrfs_put_block_group(struct btrfs_block_group_cache *cache);
 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
                           struct btrfs_root *root, unsigned long count);
 int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len);
+int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
+                            struct btrfs_root *root, u64 bytenr,
+                            u64 num_bytes, u64 *refs, u64 *flags);
 int btrfs_pin_extent(struct btrfs_root *root,
                     u64 bytenr, u64 num, int reserved);
 int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans,
@@ -2075,8 +2080,6 @@ u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags);
 void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *ionde);
 void btrfs_clear_space_info_full(struct btrfs_fs_info *info);
 
-int btrfs_reserve_metadata_space(struct btrfs_root *root, int num_items);
-int btrfs_unreserve_metadata_space(struct btrfs_root *root, int num_items);
 int btrfs_unreserve_metadata_for_delalloc(struct btrfs_root *root,
                                          struct inode *inode, int num_items);
 int btrfs_reserve_metadata_for_delalloc(struct btrfs_root *root,
@@ -2089,6 +2092,13 @@ void btrfs_delalloc_reserve_space(struct btrfs_root *root, struct inode *inode,
                                 u64 bytes);
 void btrfs_delalloc_free_space(struct btrfs_root *root, struct inode *inode,
                              u64 bytes);
+int btrfs_trans_reserve_metadata(struct btrfs_trans_handle *trans,
+                               struct btrfs_root *root,
+                               int num_items, int *retries);
+void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans,
+                               struct btrfs_root *root);
+int btrfs_snap_reserve_metadata(struct btrfs_trans_handle *trans,
+                               struct btrfs_pending_snapshot *pending);
 void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv);
 struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root);
 void btrfs_free_block_rsv(struct btrfs_root *root,
@@ -2296,6 +2306,12 @@ int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
                           struct btrfs_root *root,
                           const char *name, int name_len,
                           u64 inode_objectid, u64 ref_objectid, u64 *index);
+struct btrfs_inode_ref *
+btrfs_lookup_inode_ref(struct btrfs_trans_handle *trans,
+                       struct btrfs_root *root,
+                       struct btrfs_path *path,
+                       const char *name, int name_len,
+                       u64 inode_objectid, u64 ref_objectid, int mod);
 int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
                             struct btrfs_root *root,
                             struct btrfs_path *path, u64 objectid);
index 902ce50..e807b14 100644 (file)
@@ -319,107 +319,6 @@ out:
 }
 
 /*
- * helper function to lookup reference count and flags of extent.
- *
- * the head node for delayed ref is used to store the sum of all the
- * reference count modifications queued up in the rbtree. the head
- * node may also store the extent flags to set. This way you can check
- * to see what the reference count and extent flags would be if all of
- * the delayed refs are not processed.
- */
-int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
-                            struct btrfs_root *root, u64 bytenr,
-                            u64 num_bytes, u64 *refs, u64 *flags)
-{
-       struct btrfs_delayed_ref_node *ref;
-       struct btrfs_delayed_ref_head *head;
-       struct btrfs_delayed_ref_root *delayed_refs;
-       struct btrfs_path *path;
-       struct btrfs_extent_item *ei;
-       struct extent_buffer *leaf;
-       struct btrfs_key key;
-       u32 item_size;
-       u64 num_refs;
-       u64 extent_flags;
-       int ret;
-
-       path = btrfs_alloc_path();
-       if (!path)
-               return -ENOMEM;
-
-       key.objectid = bytenr;
-       key.type = BTRFS_EXTENT_ITEM_KEY;
-       key.offset = num_bytes;
-       delayed_refs = &trans->transaction->delayed_refs;
-again:
-       ret = btrfs_search_slot(trans, root->fs_info->extent_root,
-                               &key, path, 0, 0);
-       if (ret < 0)
-               goto out;
-
-       if (ret == 0) {
-               leaf = path->nodes[0];
-               item_size = btrfs_item_size_nr(leaf, path->slots[0]);
-               if (item_size >= sizeof(*ei)) {
-                       ei = btrfs_item_ptr(leaf, path->slots[0],
-                                           struct btrfs_extent_item);
-                       num_refs = btrfs_extent_refs(leaf, ei);
-                       extent_flags = btrfs_extent_flags(leaf, ei);
-               } else {
-#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
-                       struct btrfs_extent_item_v0 *ei0;
-                       BUG_ON(item_size != sizeof(*ei0));
-                       ei0 = btrfs_item_ptr(leaf, path->slots[0],
-                                            struct btrfs_extent_item_v0);
-                       num_refs = btrfs_extent_refs_v0(leaf, ei0);
-                       /* FIXME: this isn't correct for data */
-                       extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
-#else
-                       BUG();
-#endif
-               }
-               BUG_ON(num_refs == 0);
-       } else {
-               num_refs = 0;
-               extent_flags = 0;
-               ret = 0;
-       }
-
-       spin_lock(&delayed_refs->lock);
-       ref = find_ref_head(&delayed_refs->root, bytenr, NULL);
-       if (ref) {
-               head = btrfs_delayed_node_to_head(ref);
-               if (!mutex_trylock(&head->mutex)) {
-                       atomic_inc(&ref->refs);
-                       spin_unlock(&delayed_refs->lock);
-
-                       btrfs_release_path(root->fs_info->extent_root, path);
-
-                       mutex_lock(&head->mutex);
-                       mutex_unlock(&head->mutex);
-                       btrfs_put_delayed_ref(ref);
-                       goto again;
-               }
-               if (head->extent_op && head->extent_op->update_flags)
-                       extent_flags |= head->extent_op->flags_to_set;
-               else
-                       BUG_ON(num_refs == 0);
-
-               num_refs += ref->ref_mod;
-               mutex_unlock(&head->mutex);
-       }
-       WARN_ON(num_refs == 0);
-       if (refs)
-               *refs = num_refs;
-       if (flags)
-               *flags = extent_flags;
-out:
-       spin_unlock(&delayed_refs->lock);
-       btrfs_free_path(path);
-       return ret;
-}
-
-/*
  * helper function to update an extent delayed ref in the
  * rbtree.  existing and update must both have the same
  * bytenr and parent
index f6fc67d..50e3cf9 100644 (file)
@@ -167,9 +167,6 @@ int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans,
 struct btrfs_delayed_ref_head *
 btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr);
 int btrfs_delayed_ref_pending(struct btrfs_trans_handle *trans, u64 bytenr);
-int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
-                            struct btrfs_root *root, u64 bytenr,
-                            u64 num_bytes, u64 *refs, u64 *flags);
 int btrfs_update_delayed_ref(struct btrfs_trans_handle *trans,
                          u64 bytenr, u64 num_bytes, u64 orig_parent,
                          u64 parent, u64 orig_ref_root, u64 ref_root,
index 574594c..054b447 100644 (file)
@@ -1522,7 +1522,7 @@ static int transaction_kthread(void *arg)
                        goto sleep;
                }
                mutex_unlock(&root->fs_info->trans_mutex);
-               trans = btrfs_start_transaction(root, 1);
+               trans = btrfs_join_transaction(root, 1);
                ret = btrfs_commit_transaction(trans, root);
 
 sleep:
@@ -2409,11 +2409,11 @@ int btrfs_commit_super(struct btrfs_root *root)
        down_write(&root->fs_info->cleanup_work_sem);
        up_write(&root->fs_info->cleanup_work_sem);
 
-       trans = btrfs_start_transaction(root, 1);
+       trans = btrfs_join_transaction(root, 1);
        ret = btrfs_commit_transaction(trans, root);
        BUG_ON(ret);
        /* run commit again to drop the original snapshot */
-       trans = btrfs_start_transaction(root, 1);
+       trans = btrfs_join_transaction(root, 1);
        btrfs_commit_transaction(trans, root);
        ret = btrfs_write_and_wait_transaction(NULL, root);
        BUG_ON(ret);
index 3367278..657df6e 100644 (file)
@@ -616,6 +616,113 @@ int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
 }
 
 /*
+ * helper function to lookup reference count and flags of extent.
+ *
+ * the head node for delayed ref is used to store the sum of all the
+ * reference count modifications queued up in the rbtree. the head
+ * node may also store the extent flags to set. This way you can check
+ * to see what the reference count and extent flags would be if all of
+ * the delayed refs are not processed.
+ */
+int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
+                            struct btrfs_root *root, u64 bytenr,
+                            u64 num_bytes, u64 *refs, u64 *flags)
+{
+       struct btrfs_delayed_ref_head *head;
+       struct btrfs_delayed_ref_root *delayed_refs;
+       struct btrfs_path *path;
+       struct btrfs_extent_item *ei;
+       struct extent_buffer *leaf;
+       struct btrfs_key key;
+       u32 item_size;
+       u64 num_refs;
+       u64 extent_flags;
+       int ret;
+
+       path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
+
+       key.objectid = bytenr;
+       key.type = BTRFS_EXTENT_ITEM_KEY;
+       key.offset = num_bytes;
+       if (!trans) {
+               path->skip_locking = 1;
+               path->search_commit_root = 1;
+       }
+again:
+       ret = btrfs_search_slot(trans, root->fs_info->extent_root,
+                               &key, path, 0, 0);
+       if (ret < 0)
+               goto out_free;
+
+       if (ret == 0) {
+               leaf = path->nodes[0];
+               item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+               if (item_size >= sizeof(*ei)) {
+                       ei = btrfs_item_ptr(leaf, path->slots[0],
+                                           struct btrfs_extent_item);
+                       num_refs = btrfs_extent_refs(leaf, ei);
+                       extent_flags = btrfs_extent_flags(leaf, ei);
+               } else {
+#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
+                       struct btrfs_extent_item_v0 *ei0;
+                       BUG_ON(item_size != sizeof(*ei0));
+                       ei0 = btrfs_item_ptr(leaf, path->slots[0],
+                                            struct btrfs_extent_item_v0);
+                       num_refs = btrfs_extent_refs_v0(leaf, ei0);
+                       /* FIXME: this isn't correct for data */
+                       extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
+#else
+                       BUG();
+#endif
+               }
+               BUG_ON(num_refs == 0);
+       } else {
+               num_refs = 0;
+               extent_flags = 0;
+               ret = 0;
+       }
+
+       if (!trans)
+               goto out;
+
+       delayed_refs = &trans->transaction->delayed_refs;
+       spin_lock(&delayed_refs->lock);
+       head = btrfs_find_delayed_ref_head(trans, bytenr);
+       if (head) {
+               if (!mutex_trylock(&head->mutex)) {
+                       atomic_inc(&head->node.refs);
+                       spin_unlock(&delayed_refs->lock);
+
+                       btrfs_release_path(root->fs_info->extent_root, path);
+
+                       mutex_lock(&head->mutex);
+                       mutex_unlock(&head->mutex);
+                       btrfs_put_delayed_ref(&head->node);
+                       goto again;
+               }
+               if (head->extent_op && head->extent_op->update_flags)
+                       extent_flags |= head->extent_op->flags_to_set;
+               else
+                       BUG_ON(num_refs == 0);
+
+               num_refs += head->node.ref_mod;
+               mutex_unlock(&head->mutex);
+       }
+       spin_unlock(&delayed_refs->lock);
+out:
+       WARN_ON(num_refs == 0);
+       if (refs)
+               *refs = num_refs;
+       if (flags)
+               *flags = extent_flags;
+out_free:
+       btrfs_free_path(path);
+       return ret;
+}
+
+/*
  * Back reference rules.  Back refs have three main goals:
  *
  * 1) differentiate between all holders of references to an extent so that
@@ -2949,113 +3056,6 @@ again:
 }
 
 /*
- * unreserve num_items number of items worth of metadata space.  This needs to
- * be paired with btrfs_reserve_metadata_space.
- *
- * NOTE: if you have the option, run this _AFTER_ you do a
- * btrfs_end_transaction, since btrfs_end_transaction will run delayed ref
- * oprations which will result in more used metadata, so we want to make sure we
- * can do that without issue.
- */
-int btrfs_unreserve_metadata_space(struct btrfs_root *root, int num_items)
-{
-       struct btrfs_fs_info *info = root->fs_info;
-       struct btrfs_space_info *meta_sinfo;
-       u64 num_bytes;
-       u64 alloc_target;
-       bool bug = false;
-
-       /* get the space info for where the metadata will live */
-       alloc_target = btrfs_get_alloc_profile(root, 0);
-       meta_sinfo = __find_space_info(info, alloc_target);
-
-       num_bytes = calculate_bytes_needed(root, num_items);
-
-       spin_lock(&meta_sinfo->lock);
-       if (meta_sinfo->bytes_may_use < num_bytes) {
-               bug = true;
-               meta_sinfo->bytes_may_use = 0;
-       } else {
-               meta_sinfo->bytes_may_use -= num_bytes;
-       }
-       spin_unlock(&meta_sinfo->lock);
-
-       BUG_ON(bug);
-
-       return 0;
-}
-
-/*
- * Reserve some metadata space for use.  We'll calculate the worste case number
- * of bytes that would be needed to modify num_items number of items.  If we
- * have space, fantastic, if not, you get -ENOSPC.  Please call
- * btrfs_unreserve_metadata_space when you are done for the _SAME_ number of
- * items you reserved, since whatever metadata you needed should have already
- * been allocated.
- *
- * This will commit the transaction to make more space if we don't have enough
- * metadata space.  THe only time we don't do this is if we're reserving space
- * inside of a transaction, then we will just return -ENOSPC and it is the
- * callers responsibility to handle it properly.
- */
-int btrfs_reserve_metadata_space(struct btrfs_root *root, int num_items)
-{
-       struct btrfs_fs_info *info = root->fs_info;
-       struct btrfs_space_info *meta_sinfo;
-       u64 num_bytes;
-       u64 used;
-       u64 alloc_target;
-       int retries = 0;
-
-       /* get the space info for where the metadata will live */
-       alloc_target = btrfs_get_alloc_profile(root, 0);
-       meta_sinfo = __find_space_info(info, alloc_target);
-
-       num_bytes = calculate_bytes_needed(root, num_items);
-again:
-       spin_lock(&meta_sinfo->lock);
-
-       if (unlikely(!meta_sinfo->bytes_root))
-               meta_sinfo->bytes_root = calculate_bytes_needed(root, 6);
-
-       if (!retries)
-               meta_sinfo->bytes_may_use += num_bytes;
-
-       used = meta_sinfo->bytes_used + meta_sinfo->bytes_reserved +
-               meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly +
-               meta_sinfo->bytes_super + meta_sinfo->bytes_root +
-               meta_sinfo->bytes_may_use + meta_sinfo->bytes_delalloc;
-
-       if (used > meta_sinfo->total_bytes) {
-               retries++;
-               if (retries == 1) {
-                       if (maybe_allocate_chunk(NULL, root, meta_sinfo,
-                                                num_bytes))
-                               goto again;
-                       retries++;
-               } else {
-                       spin_unlock(&meta_sinfo->lock);
-               }
-
-               if (retries == 2) {
-                       shrink_delalloc(NULL, root, meta_sinfo, num_bytes);
-                       goto again;
-               }
-               spin_lock(&meta_sinfo->lock);
-               meta_sinfo->bytes_may_use -= num_bytes;
-               spin_unlock(&meta_sinfo->lock);
-
-               dump_space_info(meta_sinfo, 0, 0);
-               return -ENOSPC;
-       }
-
-       check_force_delalloc(meta_sinfo);
-       spin_unlock(&meta_sinfo->lock);
-
-       return 0;
-}
-
-/*
  * This will check the space that the inode allocates from to make sure we have
  * enough space for bytes.
  */
@@ -3095,9 +3095,9 @@ again:
                        spin_unlock(&data_sinfo->lock);
 alloc:
                        alloc_target = btrfs_get_alloc_profile(root, 1);
-                       trans = btrfs_start_transaction(root, 1);
-                       if (!trans)
-                               return -ENOMEM;
+                       trans = btrfs_join_transaction(root, 1);
+                       if (IS_ERR(trans))
+                               return PTR_ERR(trans);
 
                        ret = do_chunk_alloc(trans, root->fs_info->extent_root,
                                             bytes + 2 * 1024 * 1024,
@@ -3118,8 +3118,8 @@ alloc:
                if (!committed && !root->fs_info->open_ioctl_trans) {
                        committed = 1;
                        trans = btrfs_join_transaction(root, 1);
-                       if (!trans)
-                               return -ENOMEM;
+                       if (IS_ERR(trans))
+                               return PTR_ERR(trans);
                        ret = btrfs_commit_transaction(trans, root);
                        if (ret)
                                return ret;
@@ -3701,6 +3701,59 @@ static void init_global_block_rsv(struct btrfs_fs_info *fs_info)
        fs_info->chunk_root->block_rsv = &fs_info->chunk_block_rsv;
 }
 
+static u64 calc_trans_metadata_size(struct btrfs_root *root, int num_items)
+{
+       return (root->leafsize + root->nodesize * (BTRFS_MAX_LEVEL - 1)) *
+               3 * num_items;
+}
+
+int btrfs_trans_reserve_metadata(struct btrfs_trans_handle *trans,
+                                struct btrfs_root *root,
+                                int num_items, int *retries)
+{
+       u64 num_bytes;
+       int ret;
+
+       if (num_items == 0 || root->fs_info->chunk_root == root)
+               return 0;
+
+       num_bytes = calc_trans_metadata_size(root, num_items);
+       ret = btrfs_block_rsv_add(trans, root, &root->fs_info->trans_block_rsv,
+                                 num_bytes, retries);
+       if (!ret) {
+               trans->bytes_reserved += num_bytes;
+               trans->block_rsv = &root->fs_info->trans_block_rsv;
+       }
+       return ret;
+}
+
+void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans,
+                                 struct btrfs_root *root)
+{
+       if (!trans->bytes_reserved)
+               return;
+
+       BUG_ON(trans->block_rsv != &root->fs_info->trans_block_rsv);
+       btrfs_block_rsv_release(root, trans->block_rsv,
+                               trans->bytes_reserved);
+       trans->bytes_reserved = 0;
+}
+
+int btrfs_snap_reserve_metadata(struct btrfs_trans_handle *trans,
+                               struct btrfs_pending_snapshot *pending)
+{
+       struct btrfs_root *root = pending->root;
+       struct btrfs_block_rsv *src_rsv = get_block_rsv(trans, root);
+       struct btrfs_block_rsv *dst_rsv = &pending->block_rsv;
+       /*
+        * two for root back/forward refs, two for directory entries
+        * and one for root of the snapshot.
+        */
+       u64 num_bytes = calc_trans_metadata_size(root, 5);
+       dst_rsv->space_info = src_rsv->space_info;
+       return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
+}
+
 static int update_block_group(struct btrfs_trans_handle *trans,
                              struct btrfs_root *root,
                              u64 bytenr, u64 num_bytes, int alloc)
@@ -5824,7 +5877,7 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref)
        wc = kzalloc(sizeof(*wc), GFP_NOFS);
        BUG_ON(!wc);
 
-       trans = btrfs_start_transaction(tree_root, 1);
+       trans = btrfs_start_transaction(tree_root, 0);
 
        if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
                level = btrfs_header_level(root->node);
@@ -5920,7 +5973,9 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref)
                        BUG_ON(ret);
 
                        btrfs_end_transaction(trans, tree_root);
-                       trans = btrfs_start_transaction(tree_root, 1);
+                       trans = btrfs_start_transaction(tree_root, 0);
+                       if (IS_ERR(trans))
+                               return PTR_ERR(trans);
                } else {
                        unsigned long update;
                        update = trans->delayed_ref_updates;
index 29ff749..41e09e2 100644 (file)
@@ -126,8 +126,7 @@ static noinline int dirty_and_release_pages(struct btrfs_trans_handle *trans,
        end_of_last_block = start_pos + num_bytes - 1;
        err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
                                        NULL);
-       if (err)
-               return err;
+       BUG_ON(err);
 
        for (i = 0; i < num_pages; i++) {
                struct page *p = pages[i];
@@ -142,7 +141,7 @@ static noinline int dirty_and_release_pages(struct btrfs_trans_handle *trans,
                 * at this time.
                 */
        }
-       return err;
+       return 0;
 }
 
 /*
@@ -1008,7 +1007,7 @@ out_nolock:
                        num_written = err;
 
                if ((file->f_flags & O_DSYNC) || IS_SYNC(inode)) {
-                       trans = btrfs_start_transaction(root, 1);
+                       trans = btrfs_start_transaction(root, 0);
                        ret = btrfs_log_dentry_safe(trans, root,
                                                    file->f_dentry);
                        if (ret == 0) {
@@ -1104,9 +1103,9 @@ int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync)
        if (file && file->private_data)
                btrfs_ioctl_trans_end(file);
 
-       trans = btrfs_start_transaction(root, 1);
-       if (!trans) {
-               ret = -ENOMEM;
+       trans = btrfs_start_transaction(root, 0);
+       if (IS_ERR(trans)) {
+               ret = PTR_ERR(trans);
                goto out;
        }
 
index 72ce3c1..64f1150 100644 (file)
@@ -49,6 +49,33 @@ static int find_name_in_backref(struct btrfs_path *path, const char *name,
        return 0;
 }
 
+struct btrfs_inode_ref *
+btrfs_lookup_inode_ref(struct btrfs_trans_handle *trans,
+                       struct btrfs_root *root,
+                       struct btrfs_path *path,
+                       const char *name, int name_len,
+                       u64 inode_objectid, u64 ref_objectid, int mod)
+{
+       struct btrfs_key key;
+       struct btrfs_inode_ref *ref;
+       int ins_len = mod < 0 ? -1 : 0;
+       int cow = mod != 0;
+       int ret;
+
+       key.objectid = inode_objectid;
+       key.type = BTRFS_INODE_REF_KEY;
+       key.offset = ref_objectid;
+
+       ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
+       if (ret < 0)
+               return ERR_PTR(ret);
+       if (ret > 0)
+               return NULL;
+       if (!find_name_in_backref(path, name, name_len, &ref))
+               return NULL;
+       return ref;
+}
+
 int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
                           struct btrfs_root *root,
                           const char *name, int name_len,
index f444250..c4b0fd1 100644 (file)
@@ -2135,7 +2135,7 @@ void btrfs_orphan_cleanup(struct btrfs_root *root)
                 * do a destroy_inode
                 */
                if (is_bad_inode(inode)) {
-                       trans = btrfs_start_transaction(root, 1);
+                       trans = btrfs_start_transaction(root, 0);
                        btrfs_orphan_del(trans, inode);
                        btrfs_end_transaction(trans, root);
                        iput(inode);
@@ -2478,29 +2478,201 @@ out:
        return ret;
 }
 
-static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
+/* helper to check if there is any shared block in the path */
+static int check_path_shared(struct btrfs_root *root,
+                            struct btrfs_path *path)
+{
+       struct extent_buffer *eb;
+       int level;
+       int ret;
+       u64 refs;
+
+       for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
+               if (!path->nodes[level])
+                       break;
+               eb = path->nodes[level];
+               if (!btrfs_block_can_be_shared(root, eb))
+                       continue;
+               ret = btrfs_lookup_extent_info(NULL, root, eb->start, eb->len,
+                                              &refs, NULL);
+               if (refs > 1)
+                       return 1;
+       }
+       return 0;
+}
+
+/*
+ * helper to start transaction for unlink and rmdir.
+ *
+ * unlink and rmdir are special in btrfs, they do not always free space.
+ * so in enospc case, we should make sure they will free space before
+ * allowing them to use the global metadata reservation.
+ */
+static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
+                                                      struct dentry *dentry)
 {
-       struct btrfs_root *root;
        struct btrfs_trans_handle *trans;
+       struct btrfs_root *root = BTRFS_I(dir)->root;
+       struct btrfs_path *path;
+       struct btrfs_inode_ref *ref;
+       struct btrfs_dir_item *di;
        struct inode *inode = dentry->d_inode;
+       u64 index;
+       int check_link = 1;
+       int err = -ENOSPC;
        int ret;
-       unsigned long nr = 0;
 
-       root = BTRFS_I(dir)->root;
+       trans = btrfs_start_transaction(root, 10);
+       if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
+               return trans;
 
-       /*
-        * 5 items for unlink inode
-        * 1 for orphan
-        */
-       ret = btrfs_reserve_metadata_space(root, 6);
-       if (ret)
-               return ret;
+       if (inode->i_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
+               return ERR_PTR(-ENOSPC);
 
-       trans = btrfs_start_transaction(root, 1);
+       /* check if there is someone else holds reference */
+       if (S_ISDIR(inode->i_mode) && atomic_read(&inode->i_count) > 1)
+               return ERR_PTR(-ENOSPC);
+
+       if (atomic_read(&inode->i_count) > 2)
+               return ERR_PTR(-ENOSPC);
+
+       if (xchg(&root->fs_info->enospc_unlink, 1))
+               return ERR_PTR(-ENOSPC);
+
+       path = btrfs_alloc_path();
+       if (!path) {
+               root->fs_info->enospc_unlink = 0;
+               return ERR_PTR(-ENOMEM);
+       }
+
+       trans = btrfs_start_transaction(root, 0);
        if (IS_ERR(trans)) {
-               btrfs_unreserve_metadata_space(root, 6);
-               return PTR_ERR(trans);
+               btrfs_free_path(path);
+               root->fs_info->enospc_unlink = 0;
+               return trans;
+       }
+
+       path->skip_locking = 1;
+       path->search_commit_root = 1;
+
+       ret = btrfs_lookup_inode(trans, root, path,
+                               &BTRFS_I(dir)->location, 0);
+       if (ret < 0) {
+               err = ret;
+               goto out;
+       }
+       if (ret == 0) {
+               if (check_path_shared(root, path))
+                       goto out;
+       } else {
+               check_link = 0;
        }
+       btrfs_release_path(root, path);
+
+       ret = btrfs_lookup_inode(trans, root, path,
+                               &BTRFS_I(inode)->location, 0);
+       if (ret < 0) {
+               err = ret;
+               goto out;
+       }
+       if (ret == 0) {
+               if (check_path_shared(root, path))
+                       goto out;
+       } else {
+               check_link = 0;
+       }
+       btrfs_release_path(root, path);
+
+       if (ret == 0 && S_ISREG(inode->i_mode)) {
+               ret = btrfs_lookup_file_extent(trans, root, path,
+                                              inode->i_ino, (u64)-1, 0);
+               if (ret < 0) {
+                       err = ret;
+                       goto out;
+               }
+               BUG_ON(ret == 0);
+               if (check_path_shared(root, path))
+                       goto out;
+               btrfs_release_path(root, path);
+       }
+
+       if (!check_link) {
+               err = 0;
+               goto out;
+       }
+
+       di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
+                               dentry->d_name.name, dentry->d_name.len, 0);
+       if (IS_ERR(di)) {
+               err = PTR_ERR(di);
+               goto out;
+       }
+       if (di) {
+               if (check_path_shared(root, path))
+                       goto out;
+       } else {
+               err = 0;
+               goto out;
+       }
+       btrfs_release_path(root, path);
+
+       ref = btrfs_lookup_inode_ref(trans, root, path,
+                               dentry->d_name.name, dentry->d_name.len,
+                               inode->i_ino, dir->i_ino, 0);
+       if (IS_ERR(ref)) {
+               err = PTR_ERR(ref);
+               goto out;
+       }
+       BUG_ON(!ref);
+       if (check_path_shared(root, path))
+               goto out;
+       index = btrfs_inode_ref_index(path->nodes[0], ref);
+       btrfs_release_path(root, path);
+
+       di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino, index,
+                               dentry->d_name.name, dentry->d_name.len, 0);
+       if (IS_ERR(di)) {
+               err = PTR_ERR(di);
+               goto out;
+       }
+       BUG_ON(ret == -ENOENT);
+       if (check_path_shared(root, path))
+               goto out;
+
+       err = 0;
+out:
+       btrfs_free_path(path);
+       if (err) {
+               btrfs_end_transaction(trans, root);
+               root->fs_info->enospc_unlink = 0;
+               return ERR_PTR(err);
+       }
+
+       trans->block_rsv = &root->fs_info->global_block_rsv;
+       return trans;
+}
+
+static void __unlink_end_trans(struct btrfs_trans_handle *trans,
+                              struct btrfs_root *root)
+{
+       if (trans->block_rsv == &root->fs_info->global_block_rsv) {
+               BUG_ON(!root->fs_info->enospc_unlink);
+               root->fs_info->enospc_unlink = 0;
+       }
+       btrfs_end_transaction_throttle(trans, root);
+}
+
+static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+       struct btrfs_root *root = BTRFS_I(dir)->root;
+       struct btrfs_trans_handle *trans;
+       struct inode *inode = dentry->d_inode;
+       int ret;
+       unsigned long nr = 0;
+
+       trans = __unlink_start_trans(dir, dentry);
+       if (IS_ERR(trans))
+               return PTR_ERR(trans);
 
        btrfs_set_trans_block_group(trans, dir);
 
@@ -2508,14 +2680,15 @@ static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
 
        ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
                                 dentry->d_name.name, dentry->d_name.len);
+       BUG_ON(ret);
 
-       if (inode->i_nlink == 0)
+       if (inode->i_nlink == 0) {
                ret = btrfs_orphan_add(trans, inode);
+               BUG_ON(ret);
+       }
 
        nr = trans->blocks_used;
-
-       btrfs_end_transaction_throttle(trans, root);
-       btrfs_unreserve_metadata_space(root, 6);
+       __unlink_end_trans(trans, root);
        btrfs_btree_balance_dirty(root, nr);
        return ret;
 }
@@ -2587,7 +2760,6 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
 {
        struct inode *inode = dentry->d_inode;
        int err = 0;
-       int ret;
        struct btrfs_root *root = BTRFS_I(dir)->root;
        struct btrfs_trans_handle *trans;
        unsigned long nr = 0;
@@ -2596,15 +2768,9 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
            inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
                return -ENOTEMPTY;
 
-       ret = btrfs_reserve_metadata_space(root, 5);
-       if (ret)
-               return ret;
-
-       trans = btrfs_start_transaction(root, 1);
-       if (IS_ERR(trans)) {
-               btrfs_unreserve_metadata_space(root, 5);
+       trans = __unlink_start_trans(dir, dentry);
+       if (IS_ERR(trans))
                return PTR_ERR(trans);
-       }
 
        btrfs_set_trans_block_group(trans, dir);
 
@@ -2627,12 +2793,9 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
                btrfs_i_size_write(inode, 0);
 out:
        nr = trans->blocks_used;
-       ret = btrfs_end_transaction_throttle(trans, root);
-       btrfs_unreserve_metadata_space(root, 5);
+       __unlink_end_trans(trans, root);
        btrfs_btree_balance_dirty(root, nr);
 
-       if (ret && !err)
-               err = ret;
        return err;
 }
 
@@ -3145,7 +3308,7 @@ int btrfs_cont_expand(struct inode *inode, loff_t size)
        struct btrfs_trans_handle *trans;
        struct btrfs_root *root = BTRFS_I(inode)->root;
        struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
-       struct extent_map *em;
+       struct extent_map *em = NULL;
        struct extent_state *cached_state = NULL;
        u64 mask = root->sectorsize - 1;
        u64 hole_start = (inode->i_size + mask) & ~mask;
@@ -3183,11 +3346,11 @@ int btrfs_cont_expand(struct inode *inode, loff_t size)
                        u64 hint_byte = 0;
                        hole_size = last_byte - cur_offset;
 
-                       err = btrfs_reserve_metadata_space(root, 2);
-                       if (err)
+                       trans = btrfs_start_transaction(root, 2);
+                       if (IS_ERR(trans)) {
+                               err = PTR_ERR(trans);
                                break;
-
-                       trans = btrfs_start_transaction(root, 1);
+                       }
                        btrfs_set_trans_block_group(trans, inode);
 
                        err = btrfs_drop_extents(trans, inode, cur_offset,
@@ -3205,14 +3368,15 @@ int btrfs_cont_expand(struct inode *inode, loff_t size)
                                        last_byte - 1, 0);
 
                        btrfs_end_transaction(trans, root);
-                       btrfs_unreserve_metadata_space(root, 2);
                }
                free_extent_map(em);
+               em = NULL;
                cur_offset = last_byte;
                if (cur_offset >= block_end)
                        break;
        }
 
+       free_extent_map(em);
        unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
                             GFP_NOFS);
        return err;
@@ -3239,10 +3403,6 @@ static int btrfs_setattr_size(struct inode *inode, struct iattr *attr)
                }
        }
 
-       ret = btrfs_reserve_metadata_space(root, 1);
-       if (ret)
-               return ret;
-
        trans = btrfs_start_transaction(root, 1);
        btrfs_set_trans_block_group(trans, inode);
 
@@ -3251,7 +3411,6 @@ static int btrfs_setattr_size(struct inode *inode, struct iattr *attr)
 
        nr = trans->blocks_used;
        btrfs_end_transaction(trans, root);
-       btrfs_unreserve_metadata_space(root, 1);
        btrfs_btree_balance_dirty(root, nr);
 
        if (attr->ia_size > inode->i_size) {
@@ -4223,26 +4382,21 @@ static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
        if (!new_valid_dev(rdev))
                return -EINVAL;
 
+       err = btrfs_find_free_objectid(NULL, root, dir->i_ino, &objectid);
+       if (err)
+               return err;
+
        /*
         * 2 for inode item and ref
         * 2 for dir items
         * 1 for xattr if selinux is on
         */
-       err = btrfs_reserve_metadata_space(root, 5);
-       if (err)
-               return err;
+       trans = btrfs_start_transaction(root, 5);
+       if (IS_ERR(trans))
+               return PTR_ERR(trans);
 
-       trans = btrfs_start_transaction(root, 1);
-       if (!trans)
-               goto fail;
        btrfs_set_trans_block_group(trans, dir);
 
-       err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
-       if (err) {
-               err = -ENOSPC;
-               goto out_unlock;
-       }
-
        inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
                                dentry->d_name.len,
                                dentry->d_parent->d_inode->i_ino, objectid,
@@ -4271,13 +4425,11 @@ static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
 out_unlock:
        nr = trans->blocks_used;
        btrfs_end_transaction_throttle(trans, root);
-fail:
-       btrfs_unreserve_metadata_space(root, 5);
+       btrfs_btree_balance_dirty(root, nr);
        if (drop_inode) {
                inode_dec_link_count(inode);
                iput(inode);
        }
-       btrfs_btree_balance_dirty(root, nr);
        return err;
 }
 
@@ -4287,32 +4439,26 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
        struct btrfs_trans_handle *trans;
        struct btrfs_root *root = BTRFS_I(dir)->root;
        struct inode *inode = NULL;
-       int err;
        int drop_inode = 0;
+       int err;
        unsigned long nr = 0;
        u64 objectid;
        u64 index = 0;
 
+       err = btrfs_find_free_objectid(NULL, root, dir->i_ino, &objectid);
+       if (err)
+               return err;
        /*
         * 2 for inode item and ref
         * 2 for dir items
         * 1 for xattr if selinux is on
         */
-       err = btrfs_reserve_metadata_space(root, 5);
-       if (err)
-               return err;
+       trans = btrfs_start_transaction(root, 5);
+       if (IS_ERR(trans))
+               return PTR_ERR(trans);
 
-       trans = btrfs_start_transaction(root, 1);
-       if (!trans)
-               goto fail;
        btrfs_set_trans_block_group(trans, dir);
 
-       err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
-       if (err) {
-               err = -ENOSPC;
-               goto out_unlock;
-       }
-
        inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
                                dentry->d_name.len,
                                dentry->d_parent->d_inode->i_ino,
@@ -4344,8 +4490,6 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
 out_unlock:
        nr = trans->blocks_used;
        btrfs_end_transaction_throttle(trans, root);
-fail:
-       btrfs_unreserve_metadata_space(root, 5);
        if (drop_inode) {
                inode_dec_link_count(inode);
                iput(inode);
@@ -4372,21 +4516,21 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
        if (root->objectid != BTRFS_I(inode)->root->objectid)
                return -EPERM;
 
-       /*
-        * 1 item for inode ref
-        * 2 items for dir items
-        */
-       err = btrfs_reserve_metadata_space(root, 3);
-       if (err)
-               return err;
-
        btrfs_inc_nlink(inode);
 
        err = btrfs_set_inode_index(dir, &index);
        if (err)
                goto fail;
 
-       trans = btrfs_start_transaction(root, 1);
+       /*
+        * 1 item for inode ref
+        * 2 items for dir items
+        */
+       trans = btrfs_start_transaction(root, 3);
+       if (IS_ERR(trans)) {
+               err = PTR_ERR(trans);
+               goto fail;
+       }
 
        btrfs_set_trans_block_group(trans, dir);
        atomic_inc(&inode->i_count);
@@ -4405,7 +4549,6 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
        nr = trans->blocks_used;
        btrfs_end_transaction_throttle(trans, root);
 fail:
-       btrfs_unreserve_metadata_space(root, 3);
        if (drop_inode) {
                inode_dec_link_count(inode);
                iput(inode);
@@ -4425,28 +4568,20 @@ static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
        u64 index = 0;
        unsigned long nr = 1;
 
+       err = btrfs_find_free_objectid(NULL, root, dir->i_ino, &objectid);
+       if (err)
+               return err;
+
        /*
         * 2 items for inode and ref
         * 2 items for dir items
         * 1 for xattr if selinux is on
         */
-       err = btrfs_reserve_metadata_space(root, 5);
-       if (err)
-               return err;
-
-       trans = btrfs_start_transaction(root, 1);
-       if (!trans) {
-               err = -ENOMEM;
-               goto out_unlock;
-       }
+       trans = btrfs_start_transaction(root, 5);
+       if (IS_ERR(trans))
+               return PTR_ERR(trans);
        btrfs_set_trans_block_group(trans, dir);
 
-       err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
-       if (err) {
-               err = -ENOSPC;
-               goto out_fail;
-       }
-
        inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
                                dentry->d_name.len,
                                dentry->d_parent->d_inode->i_ino, objectid,
@@ -4486,9 +4621,6 @@ static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 out_fail:
        nr = trans->blocks_used;
        btrfs_end_transaction_throttle(trans, root);
-
-out_unlock:
-       btrfs_unreserve_metadata_space(root, 5);
        if (drop_on_err)
                iput(inode);
        btrfs_btree_balance_dirty(root, nr);
@@ -5426,19 +5558,6 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
        if (S_ISDIR(old_inode->i_mode) && new_inode &&
            new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
                return -ENOTEMPTY;
-
-       /*
-        * We want to reserve the absolute worst case amount of items.  So if
-        * both inodes are subvols and we need to unlink them then that would
-        * require 4 item modifications, but if they are both normal inodes it
-        * would require 5 item modifications, so we'll assume their normal
-        * inodes.  So 5 * 2 is 10, plus 1 for the new link, so 11 total items
-        * should cover the worst case number of items we'll modify.
-        */
-       ret = btrfs_reserve_metadata_space(root, 11);
-       if (ret)
-               return ret;
-
        /*
         * we're using rename to replace one file with another.
         * and the replacement file is large.  Start IO on it now so
@@ -5451,8 +5570,18 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
        /* 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);
+       /*
+        * We want to reserve the absolute worst case amount of items.  So if
+        * both inodes are subvols and we need to unlink them then that would
+        * require 4 item modifications, but if they are both normal inodes it
+        * would require 5 item modifications, so we'll assume their normal
+        * inodes.  So 5 * 2 is 10, plus 1 for the new link, so 11 total items
+        * should cover the worst case number of items we'll modify.
+        */
+       trans = btrfs_start_transaction(root, 20);
+       if (IS_ERR(trans))
+               return PTR_ERR(trans);
 
-       trans = btrfs_start_transaction(root, 1);
        btrfs_set_trans_block_group(trans, new_dir);
 
        if (dest != root)
@@ -5551,7 +5680,6 @@ out_fail:
        if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
                up_read(&root->fs_info->subvol_sem);
 
-       btrfs_unreserve_metadata_space(root, 11);
        return ret;
 }
 
@@ -5658,26 +5786,20 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
        if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
                return -ENAMETOOLONG;
 
+       err = btrfs_find_free_objectid(NULL, root, dir->i_ino, &objectid);
+       if (err)
+               return err;
        /*
         * 2 items for inode item and ref
         * 2 items for dir items
         * 1 item for xattr if selinux is on
         */
-       err = btrfs_reserve_metadata_space(root, 5);
-       if (err)
-               return err;
+       trans = btrfs_start_transaction(root, 5);
+       if (IS_ERR(trans))
+               return PTR_ERR(trans);
 
-       trans = btrfs_start_transaction(root, 1);
-       if (!trans)
-               goto out_fail;
        btrfs_set_trans_block_group(trans, dir);
 
-       err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
-       if (err) {
-               err = -ENOSPC;
-               goto out_unlock;
-       }
-
        inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
                                dentry->d_name.len,
                                dentry->d_parent->d_inode->i_ino, objectid,
@@ -5749,8 +5871,6 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
 out_unlock:
        nr = trans->blocks_used;
        btrfs_end_transaction_throttle(trans, root);
-out_fail:
-       btrfs_unreserve_metadata_space(root, 5);
        if (drop_inode) {
                inode_dec_link_count(inode);
                iput(inode);
@@ -5771,21 +5891,18 @@ static int prealloc_file_range(struct inode *inode, u64 start, u64 end,
        u64 i_size;
 
        while (num_bytes > 0) {
-               trans = btrfs_start_transaction(root, 1);
+               trans = btrfs_start_transaction(root, 3);
+               if (IS_ERR(trans)) {
+                       ret = PTR_ERR(trans);
+                       break;
+               }
 
                ret = btrfs_reserve_extent(trans, root, num_bytes,
                                           root->sectorsize, 0, alloc_hint,
                                           (u64)-1, &ins, 1);
                if (ret) {
-                       WARN_ON(1);
-                       goto stop_trans;
-               }
-
-               ret = btrfs_reserve_metadata_space(root, 3);
-               if (ret) {
-                       btrfs_free_reserved_extent(root, ins.objectid,
-                                                  ins.offset);
-                       goto stop_trans;
+                       btrfs_end_transaction(trans, root);
+                       break;
                }
 
                ret = insert_reserved_file_extent(trans, inode,
@@ -5819,14 +5936,8 @@ static int prealloc_file_range(struct inode *inode, u64 start, u64 end,
                BUG_ON(ret);
 
                btrfs_end_transaction(trans, root);
-               btrfs_unreserve_metadata_space(root, 3);
        }
        return ret;
-
-stop_trans:
-       btrfs_end_transaction(trans, root);
-       return ret;
-
 }
 
 static long btrfs_fallocate(struct inode *inode, int mode,
index 97a9783..3066da4 100644 (file)
@@ -239,23 +239,19 @@ static noinline int create_subvol(struct btrfs_root *root,
        u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
        u64 index = 0;
 
+       ret = btrfs_find_free_objectid(NULL, root->fs_info->tree_root,
+                                      0, &objectid);
+       if (ret)
+               return ret;
        /*
         * 1 - inode item
         * 2 - refs
         * 1 - root item
         * 2 - dir items
         */
-       ret = btrfs_reserve_metadata_space(root, 6);
-       if (ret)
-               return ret;
-
-       trans = btrfs_start_transaction(root, 1);
-       BUG_ON(!trans);
-
-       ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
-                                      0, &objectid);
-       if (ret)
-               goto fail;
+       trans = btrfs_start_transaction(root, 6);
+       if (IS_ERR(trans))
+               return PTR_ERR(trans);
 
        leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
                                      0, objectid, NULL, 0, 0, 0);
@@ -345,13 +341,10 @@ fail:
        err = btrfs_commit_transaction(trans, root);
        if (err && !ret)
                ret = err;
-
-       btrfs_unreserve_metadata_space(root, 6);
        return ret;
 }
 
-static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
-                          char *name, int namelen)
+static int create_snapshot(struct btrfs_root *root, struct dentry *dentry)
 {
        struct inode *inode;
        struct btrfs_pending_snapshot *pending_snapshot;
@@ -361,40 +354,33 @@ static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
        if (!root->ref_cows)
                return -EINVAL;
 
-       /*
-        * 1 - inode item
-        * 2 - refs
-        * 1 - root item
-        * 2 - dir items
-        */
-       ret = btrfs_reserve_metadata_space(root, 6);
-       if (ret)
-               goto fail;
-
        pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
-       if (!pending_snapshot) {
-               ret = -ENOMEM;
-               btrfs_unreserve_metadata_space(root, 6);
-               goto fail;
-       }
-       pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS);
-       if (!pending_snapshot->name) {
-               ret = -ENOMEM;
-               kfree(pending_snapshot);
-               btrfs_unreserve_metadata_space(root, 6);
-               goto fail;
-       }
-       memcpy(pending_snapshot->name, name, namelen);
-       pending_snapshot->name[namelen] = '\0';
+       if (!pending_snapshot)
+               return -ENOMEM;
+
+       btrfs_init_block_rsv(&pending_snapshot->block_rsv);
        pending_snapshot->dentry = dentry;
-       trans = btrfs_start_transaction(root, 1);
-       BUG_ON(!trans);
        pending_snapshot->root = root;
+
+       trans = btrfs_start_transaction(root->fs_info->extent_root, 5);
+       if (IS_ERR(trans)) {
+               ret = PTR_ERR(trans);
+               goto fail;
+       }
+
+       ret = btrfs_snap_reserve_metadata(trans, pending_snapshot);
+       BUG_ON(ret);
+
        list_add(&pending_snapshot->list,
                 &trans->transaction->pending_snapshots);
-       ret = btrfs_commit_transaction(trans, root);
+       ret = btrfs_commit_transaction(trans, root->fs_info->extent_root);
        BUG_ON(ret);
-       btrfs_unreserve_metadata_space(root, 6);
+
+       ret = pending_snapshot->error;
+       if (ret)
+               goto fail;
+
+       btrfs_orphan_cleanup(pending_snapshot->snap);
 
        inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry);
        if (IS_ERR(inode)) {
@@ -405,6 +391,7 @@ static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
        d_instantiate(dentry, inode);
        ret = 0;
 fail:
+       kfree(pending_snapshot);
        return ret;
 }
 
@@ -456,8 +443,7 @@ static noinline int btrfs_mksubvol(struct path *parent,
                goto out_up_read;
 
        if (snap_src) {
-               error = create_snapshot(snap_src, dentry,
-                                       name, namelen);
+               error = create_snapshot(snap_src, dentry);
        } else {
                error = create_subvol(BTRFS_I(dir)->root, dentry,
                                      name, namelen);
@@ -811,7 +797,7 @@ static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
                device->name, (unsigned long long)new_size);
 
        if (new_size > old_size) {
-               trans = btrfs_start_transaction(root, 1);
+               trans = btrfs_start_transaction(root, 0);
                ret = btrfs_grow_device(trans, device, new_size);
                btrfs_commit_transaction(trans, root);
        } else {
@@ -1300,7 +1286,13 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
        if (err)
                goto out_up_write;
 
-       trans = btrfs_start_transaction(root, 1);
+       trans = btrfs_start_transaction(root, 0);
+       if (IS_ERR(trans)) {
+               err = PTR_ERR(trans);
+               goto out;
+       }
+       trans->block_rsv = &root->fs_info->global_block_rsv;
+
        ret = btrfs_unlink_subvol(trans, root, dir,
                                dest->root_key.objectid,
                                dentry->d_name.name,
@@ -1550,12 +1542,6 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
                btrfs_wait_ordered_range(src, off, off+len);
        }
 
-       trans = btrfs_start_transaction(root, 1);
-       BUG_ON(!trans);
-
-       /* punch hole in destination first */
-       btrfs_drop_extents(trans, inode, off, off + len, &hint_byte, 1);
-
        /* clone data */
        key.objectid = src->i_ino;
        key.type = BTRFS_EXTENT_DATA_KEY;
@@ -1566,7 +1552,7 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
                 * note the key will change type as we walk through the
                 * tree.
                 */
-               ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
+               ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
                if (ret < 0)
                        goto out;
 
@@ -1629,12 +1615,31 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
                        new_key.objectid = inode->i_ino;
                        new_key.offset = key.offset + destoff - off;
 
+                       trans = btrfs_start_transaction(root, 1);
+                       if (IS_ERR(trans)) {
+                               ret = PTR_ERR(trans);
+                               goto out;
+                       }
+
                        if (type == BTRFS_FILE_EXTENT_REG ||
                            type == BTRFS_FILE_EXTENT_PREALLOC) {
+                               if (off > key.offset) {
+                                       datao += off - key.offset;
+                                       datal -= off - key.offset;
+                               }
+
+                               if (key.offset + datal > off + len)
+                                       datal = off + len - key.offset;
+
+                               ret = btrfs_drop_extents(trans, inode,
+                                                        new_key.offset,
+                                                        new_key.offset + datal,
+                                                        &hint_byte, 1);
+                               BUG_ON(ret);
+
                                ret = btrfs_insert_empty_item(trans, root, path,
                                                              &new_key, size);
-                               if (ret)
-                                       goto out;
+                               BUG_ON(ret);
 
                                leaf = path->nodes[0];
                                slot = path->slots[0];
@@ -1645,14 +1650,6 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
                                extent = btrfs_item_ptr(leaf, slot,
                                                struct btrfs_file_extent_item);
 
-                               if (off > key.offset) {
-                                       datao += off - key.offset;
-                                       datal -= off - key.offset;
-                               }
-
-                               if (key.offset + datal > off + len)
-                                       datal = off + len - key.offset;
-
                                /* disko == 0 means it's a hole */
                                if (!disko)
                                        datao = 0;
@@ -1683,14 +1680,21 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
 
                                if (comp && (skip || trim)) {
                                        ret = -EINVAL;
+                                       btrfs_end_transaction(trans, root);
                                        goto out;
                                }
                                size -= skip + trim;
                                datal -= skip + trim;
+
+                               ret = btrfs_drop_extents(trans, inode,
+                                                        new_key.offset,
+                                                        new_key.offset + datal,
+                                                        &hint_byte, 1);
+                               BUG_ON(ret);
+
                                ret = btrfs_insert_empty_item(trans, root, path,
                                                              &new_key, size);
-                               if (ret)
-                                       goto out;
+                               BUG_ON(ret);
 
                                if (skip) {
                                        u32 start =
@@ -1708,8 +1712,17 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
                        }
 
                        btrfs_mark_buffer_dirty(leaf);
-               }
+                       btrfs_release_path(root, path);
 
+                       inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+                       if (new_key.offset + datal > inode->i_size)
+                               btrfs_i_size_write(inode,
+                                                  new_key.offset + datal);
+                       BTRFS_I(inode)->flags = BTRFS_I(src)->flags;
+                       ret = btrfs_update_inode(trans, root, inode);
+                       BUG_ON(ret);
+                       btrfs_end_transaction(trans, root);
+               }
 next:
                btrfs_release_path(root, path);
                key.offset++;
@@ -1717,17 +1730,7 @@ next:
        ret = 0;
 out:
        btrfs_release_path(root, path);
-       if (ret == 0) {
-               inode->i_mtime = inode->i_ctime = CURRENT_TIME;
-               if (destoff + olen > inode->i_size)
-                       btrfs_i_size_write(inode, destoff + olen);
-               BTRFS_I(inode)->flags = BTRFS_I(src)->flags;
-               ret = btrfs_update_inode(trans, root, inode);
-       }
-       btrfs_end_transaction(trans, root);
        unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
-       if (ret)
-               vmtruncate(inode, 0);
 out_unlock:
        mutex_unlock(&src->i_mutex);
        mutex_unlock(&inode->i_mutex);
index d565b45..145a468 100644 (file)
@@ -1649,7 +1649,7 @@ static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
        }
 
        if (level == 0 && rc->stage == UPDATE_DATA_PTRS) {
-               trans = btrfs_start_transaction(root, 1);
+               trans = btrfs_start_transaction(root, 0);
 
                leaf = path->nodes[0];
                btrfs_item_key_to_cpu(leaf, &key, 0);
@@ -1675,7 +1675,7 @@ static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
        while (1) {
                leaf = NULL;
                replaced = 0;
-               trans = btrfs_start_transaction(root, 1);
+               trans = btrfs_start_transaction(root, 0);
                max_level = level;
 
                ret = walk_down_reloc_tree(reloc_root, path, &level);
@@ -1803,7 +1803,7 @@ static void merge_func(struct btrfs_work *work)
 
                merge_reloc_root(async->rc, root);
 
-               trans = btrfs_start_transaction(root, 1);
+               trans = btrfs_start_transaction(root, 0);
                btrfs_update_reloc_root(trans, root);
                btrfs_end_transaction(trans, root);
        }
@@ -3297,11 +3297,11 @@ static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
        rc->create_reloc_root = 1;
        set_reloc_control(rc);
 
-       trans = btrfs_start_transaction(rc->extent_root, 1);
+       trans = btrfs_join_transaction(rc->extent_root, 1);
        btrfs_commit_transaction(trans, rc->extent_root);
 
        while (1) {
-               trans = btrfs_start_transaction(rc->extent_root, 1);
+               trans = btrfs_start_transaction(rc->extent_root, 0);
 
                ret = find_next_extent(trans, rc, path);
                if (ret < 0)
@@ -3411,7 +3411,7 @@ static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
        smp_mb();
 
        if (rc->extents_found > 0) {
-               trans = btrfs_start_transaction(rc->extent_root, 1);
+               trans = btrfs_join_transaction(rc->extent_root, 1);
                btrfs_commit_transaction(trans, rc->extent_root);
        }
 
@@ -3420,7 +3420,7 @@ static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
        unset_reloc_control(rc);
 
        /* get rid of pinned extents */
-       trans = btrfs_start_transaction(rc->extent_root, 1);
+       trans = btrfs_join_transaction(rc->extent_root, 1);
        btrfs_commit_transaction(trans, rc->extent_root);
 
        return err;
@@ -3475,7 +3475,7 @@ static struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
        if (IS_ERR(root))
                return ERR_CAST(root);
 
-       trans = btrfs_start_transaction(root, 1);
+       trans = btrfs_start_transaction(root, 6);
        BUG_ON(!trans);
 
        err = btrfs_find_free_objectid(trans, root, objectid, &objectid);
@@ -3619,7 +3619,7 @@ 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);
+       trans = btrfs_start_transaction(root->fs_info->tree_root, 0);
 
        memset(&root->root_item.drop_progress, 0,
                sizeof(root->root_item.drop_progress));
index 55265c2..38d91c7 100644 (file)
@@ -498,7 +498,7 @@ int btrfs_sync_fs(struct super_block *sb, int wait)
        btrfs_start_delalloc_inodes(root, 0);
        btrfs_wait_ordered_extents(root, 0, 0);
 
-       trans = btrfs_start_transaction(root, 1);
+       trans = btrfs_start_transaction(root, 0);
        ret = btrfs_commit_transaction(trans, root);
        return ret;
 }
index 21ad37c..2616491 100644 (file)
@@ -165,53 +165,89 @@ enum btrfs_trans_type {
        TRANS_USERSPACE,
 };
 
+static int may_wait_transaction(struct btrfs_root *root, int type)
+{
+       if (!root->fs_info->log_root_recovering &&
+           ((type == TRANS_START && !root->fs_info->open_ioctl_trans) ||
+            type == TRANS_USERSPACE))
+               return 1;
+       return 0;
+}
+
 static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
-                                            int num_blocks, int type)
+                                                   u64 num_items, int type)
 {
-       struct btrfs_trans_handle *h =
-               kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
+       struct btrfs_trans_handle *h;
+       struct btrfs_transaction *cur_trans;
+       int retries = 0;
        int ret;
+again:
+       h = kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
+       if (!h)
+               return ERR_PTR(-ENOMEM);
 
        mutex_lock(&root->fs_info->trans_mutex);
-       if (!root->fs_info->log_root_recovering &&
-           ((type == TRANS_START && !root->fs_info->open_ioctl_trans) ||
-            type == TRANS_USERSPACE))
+       if (may_wait_transaction(root, type))
                wait_current_trans(root);
+
        ret = join_transaction(root);
        BUG_ON(ret);
 
-       h->transid = root->fs_info->running_transaction->transid;
-       h->transaction = root->fs_info->running_transaction;
-       h->blocks_reserved = num_blocks;
+       cur_trans = root->fs_info->running_transaction;
+       cur_trans->use_count++;
+       mutex_unlock(&root->fs_info->trans_mutex);
+
+       h->transid = cur_trans->transid;
+       h->transaction = cur_trans;
        h->blocks_used = 0;
        h->block_group = 0;
+       h->bytes_reserved = 0;
        h->delayed_ref_updates = 0;
        h->block_rsv = NULL;
 
-       if (!current->journal_info && type != TRANS_USERSPACE)
-               current->journal_info = h;
+       smp_mb();
+       if (cur_trans->blocked && may_wait_transaction(root, type)) {
+               btrfs_commit_transaction(h, root);
+               goto again;
+       }
+
+       if (num_items > 0) {
+               ret = btrfs_trans_reserve_metadata(h, root, num_items,
+                                                  &retries);
+               if (ret == -EAGAIN) {
+                       btrfs_commit_transaction(h, root);
+                       goto again;
+               }
+               if (ret < 0) {
+                       btrfs_end_transaction(h, root);
+                       return ERR_PTR(ret);
+               }
+       }
 
-       root->fs_info->running_transaction->use_count++;
+       mutex_lock(&root->fs_info->trans_mutex);
        record_root_in_trans(h, root);
        mutex_unlock(&root->fs_info->trans_mutex);
+
+       if (!current->journal_info && type != TRANS_USERSPACE)
+               current->journal_info = h;
        return h;
 }
 
 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
-                                                  int num_blocks)
+                                                  int num_items)
 {
-       return start_transaction(root, num_blocks, TRANS_START);
+       return start_transaction(root, num_items, TRANS_START);
 }
 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root,
                                                   int num_blocks)
 {
-       return start_transaction(root, num_blocks, TRANS_JOIN);
+       return start_transaction(root, 0, TRANS_JOIN);
 }
 
 struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *r,
                                                         int num_blocks)
 {
-       return start_transaction(r, num_blocks, TRANS_USERSPACE);
+       return start_transaction(r, 0, TRANS_USERSPACE);
 }
 
 /* wait for a transaction commit to be fully complete */
@@ -312,6 +348,8 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
                count++;
        }
 
+       btrfs_trans_release_metadata(trans, root);
+
        mutex_lock(&info->trans_mutex);
        cur_trans = info->running_transaction;
        WARN_ON(cur_trans != trans->transaction);
@@ -757,47 +795,49 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
        struct btrfs_root *root = pending->root;
        struct btrfs_root *parent_root;
        struct inode *parent_inode;
+       struct dentry *dentry;
        struct extent_buffer *tmp;
        struct extent_buffer *old;
        int ret;
-       u64 objectid;
-       int namelen;
        u64 index = 0;
-
-       parent_inode = pending->dentry->d_parent->d_inode;
-       parent_root = BTRFS_I(parent_inode)->root;
+       u64 objectid;
 
        new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
        if (!new_root_item) {
-               ret = -ENOMEM;
+               pending->error = -ENOMEM;
                goto fail;
        }
+
        ret = btrfs_find_free_objectid(trans, tree_root, 0, &objectid);
-       if (ret)
+       if (ret) {
+               pending->error = ret;
                goto fail;
+       }
 
        key.objectid = objectid;
-       /* record when the snapshot was created in key.offset */
-       key.offset = trans->transid;
-       btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
+       key.offset = (u64)-1;
+       key.type = BTRFS_ROOT_ITEM_KEY;
 
-       memcpy(&pending->root_key, &key, sizeof(key));
-       pending->root_key.offset = (u64)-1;
+       trans->block_rsv = &pending->block_rsv;
 
+       dentry = pending->dentry;
+       parent_inode = dentry->d_parent->d_inode;
+       parent_root = BTRFS_I(parent_inode)->root;
        record_root_in_trans(trans, parent_root);
+
        /*
         * insert the directory item
         */
-       namelen = strlen(pending->name);
        ret = btrfs_set_inode_index(parent_inode, &index);
        BUG_ON(ret);
        ret = btrfs_insert_dir_item(trans, parent_root,
-                           pending->name, namelen,
-                           parent_inode->i_ino,
-                           &pending->root_key, BTRFS_FT_DIR, index);
+                               dentry->d_name.name, dentry->d_name.len,
+                               parent_inode->i_ino, &key,
+                               BTRFS_FT_DIR, index);
        BUG_ON(ret);
 
-       btrfs_i_size_write(parent_inode, parent_inode->i_size + namelen * 2);
+       btrfs_i_size_write(parent_inode, parent_inode->i_size +
+                                        dentry->d_name.len * 2);
        ret = btrfs_update_inode(trans, parent_root, parent_inode);
        BUG_ON(ret);
 
@@ -814,22 +854,29 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
        free_extent_buffer(old);
 
        btrfs_set_root_node(new_root_item, tmp);
-       ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
-                               new_root_item);
-       BUG_ON(ret);
+       /* record when the snapshot was created in key.offset */
+       key.offset = trans->transid;
+       ret = btrfs_insert_root(trans, tree_root, &key, new_root_item);
        btrfs_tree_unlock(tmp);
        free_extent_buffer(tmp);
+       BUG_ON(ret);
 
-       ret = btrfs_add_root_ref(trans, parent_root->fs_info->tree_root,
-                                pending->root_key.objectid,
+       /*
+        * insert root back/forward references
+        */
+       ret = btrfs_add_root_ref(trans, tree_root, objectid,
                                 parent_root->root_key.objectid,
-                                parent_inode->i_ino, index, pending->name,
-                                namelen);
+                                parent_inode->i_ino, index,
+                                dentry->d_name.name, dentry->d_name.len);
        BUG_ON(ret);
 
+       key.offset = (u64)-1;
+       pending->snap = btrfs_read_fs_root_no_name(root->fs_info, &key);
+       BUG_ON(IS_ERR(pending->snap));
 fail:
        kfree(new_root_item);
-       return ret;
+       btrfs_block_rsv_release(root, &pending->block_rsv, (u64)-1);
+       return 0;
 }
 
 /*
@@ -898,6 +945,8 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
        ret = btrfs_run_delayed_refs(trans, root, 0);
        BUG_ON(ret);
 
+       btrfs_trans_release_metadata(trans, root);
+
        cur_trans = trans->transaction;
        /*
         * set the flushing flag so procs in this transaction have to
index 56e728d..14b3841 100644 (file)
@@ -57,8 +57,11 @@ struct btrfs_trans_handle {
 struct btrfs_pending_snapshot {
        struct dentry *dentry;
        struct btrfs_root *root;
-       char *name;
-       struct btrfs_key root_key;
+       struct btrfs_root *snap;
+       /* block reservation for the operation */
+       struct btrfs_block_rsv block_rsv;
+       /* extra metadata reseration for relocation */
+       int error;
        struct list_head list;
 };
 
@@ -85,11 +88,11 @@ static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
                          struct btrfs_root *root);
 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
-                                                  int num_blocks);
+                                                  int num_items);
 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root,
-                                                  int num_blocks);
+                                                 int num_blocks);
 struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *r,
-                                                  int num_blocks);
+                                                        int num_blocks);
 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
                                     struct btrfs_root *root);
 int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
index 8db7b14..d6e3af8 100644 (file)
@@ -1097,7 +1097,7 @@ static int btrfs_rm_dev_item(struct btrfs_root *root,
        if (!path)
                return -ENOMEM;
 
-       trans = btrfs_start_transaction(root, 1);
+       trans = btrfs_start_transaction(root, 0);
        key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
        key.type = BTRFS_DEV_ITEM_KEY;
        key.offset = device->devid;
@@ -1486,7 +1486,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
                goto error;
        }
 
-       trans = btrfs_start_transaction(root, 1);
+       trans = btrfs_start_transaction(root, 0);
        lock_chunks(root);
 
        device->barriers = 1;
@@ -1751,9 +1751,10 @@ static int btrfs_relocate_chunk(struct btrfs_root *root,
 
        /* step one, relocate all the extents inside this chunk */
        ret = btrfs_relocate_block_group(extent_root, chunk_offset);
-       BUG_ON(ret);
+       if (ret)
+               return ret;
 
-       trans = btrfs_start_transaction(root, 1);
+       trans = btrfs_start_transaction(root, 0);
        BUG_ON(!trans);
 
        lock_chunks(root);
@@ -1925,7 +1926,7 @@ int btrfs_balance(struct btrfs_root *dev_root)
                        break;
                BUG_ON(ret);
 
-               trans = btrfs_start_transaction(dev_root, 1);
+               trans = btrfs_start_transaction(dev_root, 0);
                BUG_ON(!trans);
 
                ret = btrfs_grow_device(trans, device, old_size);
@@ -2094,11 +2095,7 @@ again:
        }
 
        /* Shrinking succeeded, else we would be at "done". */
-       trans = btrfs_start_transaction(root, 1);
-       if (!trans) {
-               ret = -ENOMEM;
-               goto done;
-       }
+       trans = btrfs_start_transaction(root, 0);
        lock_chunks(root);
 
        device->disk_total_bytes = new_size;
index 193b58f..007fae5 100644 (file)
@@ -154,15 +154,10 @@ int __btrfs_setxattr(struct btrfs_trans_handle *trans,
        if (trans)
                return do_setxattr(trans, inode, name, value, size, flags);
 
-       ret = btrfs_reserve_metadata_space(root, 2);
-       if (ret)
-               return ret;
+       trans = btrfs_start_transaction(root, 2);
+       if (IS_ERR(trans))
+               return PTR_ERR(trans);
 
-       trans = btrfs_start_transaction(root, 1);
-       if (!trans) {
-               ret = -ENOMEM;
-               goto out;
-       }
        btrfs_set_trans_block_group(trans, inode);
 
        ret = do_setxattr(trans, inode, name, value, size, flags);
@@ -174,7 +169,6 @@ int __btrfs_setxattr(struct btrfs_trans_handle *trans,
        BUG_ON(ret);
 out:
        btrfs_end_transaction_throttle(trans, root);
-       btrfs_unreserve_metadata_space(root, 2);
        return ret;
 }