Merge branch 'for-chris' of git://git.jan-o-sch.net/btrfs-unstable into integration

1 files changed, 140 insertions, 47 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 1c1cf216be80..a44072a692ab 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1871,20 +1871,24 @@ static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
                          struct btrfs_root *root,
                          u64 bytenr, u64 num_bytes, u64 parent,
-                         u64 root_objectid, u64 owner, u64 offset)
+                         u64 root_objectid, u64 owner, u64 offset, int for_cow)
 {
         int ret;
+        struct btrfs_fs_info *fs_info = root->fs_info;
+
         BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID &&
                root_objectid == BTRFS_TREE_LOG_OBJECTID);
 
         if (owner < BTRFS_FIRST_FREE_OBJECTID) {
-                ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
+                ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
+                                        num_bytes,
                                         parent, root_objectid, (int)owner,
-                                        BTRFS_ADD_DELAYED_REF, NULL);
+                                        BTRFS_ADD_DELAYED_REF, NULL, for_cow);
         } else {
-                ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
+                ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr,
+                                        num_bytes,
                                         parent, root_objectid, owner, offset,
-                                        BTRFS_ADD_DELAYED_REF, NULL);
+                                        BTRFS_ADD_DELAYED_REF, NULL, for_cow);
         }
         return ret;
 }
@@ -2232,6 +2236,28 @@ static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
                 }
 
                 /*
+                 * locked_ref is the head node, so we have to go one
+                 * node back for any delayed ref updates
+                 */
+                ref = select_delayed_ref(locked_ref);
+
+                if (ref && ref->seq &&
+                    btrfs_check_delayed_seq(delayed_refs, ref->seq)) {
+                        /*
+                         * there are still refs with lower seq numbers in the
+                         * process of being added. Don't run this ref yet.
+                         */
+                        list_del_init(&locked_ref->cluster);
+                        mutex_unlock(&locked_ref->mutex);
+                        locked_ref = NULL;
+                        delayed_refs->num_heads_ready++;
+                        spin_unlock(&delayed_refs->lock);
+                        cond_resched();
+                        spin_lock(&delayed_refs->lock);
+                        continue;
+                }
+
+                /*
                  * record the must insert reserved flag before we
                  * drop the spin lock.
                  */
@@ -2241,11 +2267,6 @@ static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
                 extent_op = locked_ref->extent_op;
                 locked_ref->extent_op = NULL;
 
-                /*
-                 * locked_ref is the head node, so we have to go one
-                 * node back for any delayed ref updates
-                 */
-                ref = select_delayed_ref(locked_ref);
                 if (!ref) {
                         /* All delayed refs have been processed, Go ahead
                          * and send the head node to run_one_delayed_ref,
@@ -2276,7 +2297,12 @@ static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
                 ref->in_tree = 0;
                 rb_erase(&ref->rb_node, &delayed_refs->root);
                 delayed_refs->num_entries--;
-
+                /*
+                 * we modified num_entries, but as we're currently running
+                 * delayed refs, skip
+                 *     wake_up(&delayed_refs->seq_wait);
+                 * here.
+                 */
                 spin_unlock(&delayed_refs->lock);
 
                 ret = run_one_delayed_ref(trans, root, ref, extent_op,
@@ -2297,6 +2323,23 @@ next:
         return count;
 }
 
+
+static void wait_for_more_refs(struct btrfs_delayed_ref_root *delayed_refs,
+                        unsigned long num_refs)
+{
+        struct list_head *first_seq = delayed_refs->seq_head.next;
+
+        spin_unlock(&delayed_refs->lock);
+        pr_debug("waiting for more refs (num %ld, first %p)\n",
+                 num_refs, first_seq);
+        wait_event(delayed_refs->seq_wait,
+                   num_refs != delayed_refs->num_entries ||
+                   delayed_refs->seq_head.next != first_seq);
+        pr_debug("done waiting for more refs (num %ld, first %p)\n",
+                 delayed_refs->num_entries, delayed_refs->seq_head.next);
+        spin_lock(&delayed_refs->lock);
+}
+
 /*
  * this starts processing the delayed reference count updates and
  * extent insertions we have queued up so far.  count can be
@@ -2312,8 +2355,11 @@ int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
         struct btrfs_delayed_ref_node *ref;
         struct list_head cluster;
         int ret;
+        u64 delayed_start;
         int run_all = count == (unsigned long)-1;
         int run_most = 0;
+        unsigned long num_refs = 0;
+        int consider_waiting;
 
         if (root == root->fs_info->extent_root)
                 root = root->fs_info->tree_root;
@@ -2325,6 +2371,7 @@ int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
         delayed_refs = &trans->transaction->delayed_refs;
         INIT_LIST_HEAD(&cluster);
 again:
+        consider_waiting = 0;
         spin_lock(&delayed_refs->lock);
         if (count == 0) {
                 count = delayed_refs->num_entries * 2;
@@ -2341,11 +2388,35 @@ again:
                  * of refs to process starting at the first one we are able to
                  * lock
                  */
+                delayed_start = delayed_refs->run_delayed_start;
                 ret = btrfs_find_ref_cluster(trans, &cluster,
                                              delayed_refs->run_delayed_start);
                 if (ret)
                         break;
 
+                if (delayed_start >= delayed_refs->run_delayed_start) {
+                        if (consider_waiting == 0) {
+                                /*
+                                 * btrfs_find_ref_cluster looped. let's do one
+                                 * more cycle. if we don't run any delayed ref
+                                 * during that cycle (because we can't because
+                                 * all of them are blocked) and if the number of
+                                 * refs doesn't change, we avoid busy waiting.
+                                 */
+                                consider_waiting = 1;
+                                num_refs = delayed_refs->num_entries;
+                        } else {
+                                wait_for_more_refs(delayed_refs, num_refs);
+                                /*
+                                 * after waiting, things have changed. we
+                                 * dropped the lock and someone else might have
+                                 * run some refs, built new clusters and so on.
+                                 * therefore, we restart staleness detection.
+                                 */
+                                consider_waiting = 0;
+                        }
+                }
+
                 ret = run_clustered_refs(trans, root, &cluster);
                 BUG_ON(ret < 0);
 
@@ -2353,6 +2424,11 @@ again:
 
                 if (count == 0)
                         break;
+
+                if (ret || delayed_refs->run_delayed_start == 0) {
+                        /* refs were run, let's reset staleness detection */
+                        consider_waiting = 0;
+                }
         }
 
         if (run_all) {
@@ -2410,7 +2486,8 @@ int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
         extent_op->update_key = 0;
         extent_op->is_data = is_data ? 1 : 0;
 
-        ret = btrfs_add_delayed_extent_op(trans, bytenr, num_bytes, extent_op);
+        ret = btrfs_add_delayed_extent_op(root->fs_info, trans, bytenr,
+                                          num_bytes, extent_op);
         if (ret)
                 kfree(extent_op);
         return ret;
@@ -2595,7 +2672,7 @@ out:
 static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
                            struct btrfs_root *root,
                            struct extent_buffer *buf,
-                           int full_backref, int inc)
+                           int full_backref, int inc, int for_cow)
 {
         u64 bytenr;
         u64 num_bytes;
@@ -2608,7 +2685,7 @@ static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
         int level;
         int ret = 0;
         int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
-                            u64, u64, u64, u64, u64, u64);
+                            u64, u64, u64, u64, u64, u64, int);
 
         ref_root = btrfs_header_owner(buf);
         nritems = btrfs_header_nritems(buf);
@@ -2645,14 +2722,15 @@ static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
                         key.offset -= btrfs_file_extent_offset(buf, fi);
                         ret = process_func(trans, root, bytenr, num_bytes,
                                            parent, ref_root, key.objectid,
-                                           key.offset);
+                                           key.offset, for_cow);
                         if (ret)
                                 goto fail;
                 } else {
                         bytenr = btrfs_node_blockptr(buf, i);
                         num_bytes = btrfs_level_size(root, level - 1);
                         ret = process_func(trans, root, bytenr, num_bytes,
-                                           parent, ref_root, level - 1, 0);
+                                           parent, ref_root, level - 1, 0,
+                                           for_cow);
                         if (ret)
                                 goto fail;
                 }
@@ -2664,15 +2742,15 @@ fail:
 }
 
 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-                  struct extent_buffer *buf, int full_backref)
+                  struct extent_buffer *buf, int full_backref, int for_cow)
 {
-        return __btrfs_mod_ref(trans, root, buf, full_backref, 1);
+        return __btrfs_mod_ref(trans, root, buf, full_backref, 1, for_cow);
 }
 
 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-                  struct extent_buffer *buf, int full_backref)
+                  struct extent_buffer *buf, int full_backref, int for_cow)
 {
-        return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
+        return __btrfs_mod_ref(trans, root, buf, full_backref, 0, for_cow);
 }
 
 static int write_one_cache_group(struct btrfs_trans_handle *trans,
@@ -4954,6 +5032,8 @@ static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
         rb_erase(&head->node.rb_node, &delayed_refs->root);
 
         delayed_refs->num_entries--;
+        if (waitqueue_active(&delayed_refs->seq_wait))
+                wake_up(&delayed_refs->seq_wait);
 
         /*
          * we don't take a ref on the node because we're removing it from the
@@ -4981,16 +5061,17 @@ out:
 void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
                            struct btrfs_root *root,
                            struct extent_buffer *buf,
-                           u64 parent, int last_ref)
+                           u64 parent, int last_ref, int for_cow)
 {
         struct btrfs_block_group_cache *cache = NULL;
         int ret;
 
         if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
-                ret = btrfs_add_delayed_tree_ref(trans, buf->start, buf->len,
-                                                parent, root->root_key.objectid,
-                                                btrfs_header_level(buf),
-                                                BTRFS_DROP_DELAYED_REF, NULL);
+                ret = btrfs_add_delayed_tree_ref(root->fs_info, trans,
+                                        buf->start, buf->len,
+                                        parent, root->root_key.objectid,
+                                        btrfs_header_level(buf),
+                                        BTRFS_DROP_DELAYED_REF, NULL, for_cow);
                 BUG_ON(ret);
         }
 
@@ -5025,12 +5106,12 @@ out:
         btrfs_put_block_group(cache);
 }
 
-int btrfs_free_extent(struct btrfs_trans_handle *trans,
-                      struct btrfs_root *root,
-                      u64 bytenr, u64 num_bytes, u64 parent,
-                      u64 root_objectid, u64 owner, u64 offset)
+int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+                      u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid,
+                      u64 owner, u64 offset, int for_cow)
 {
         int ret;
+        struct btrfs_fs_info *fs_info = root->fs_info;
 
         /*
          * tree log blocks never actually go into the extent allocation
@@ -5042,14 +5123,17 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans,
                 btrfs_pin_extent(root, bytenr, num_bytes, 1);
                 ret = 0;
         } else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
-                ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
+                ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
+                                        num_bytes,
                                         parent, root_objectid, (int)owner,
-                                        BTRFS_DROP_DELAYED_REF, NULL);
+                                        BTRFS_DROP_DELAYED_REF, NULL, for_cow);
                 BUG_ON(ret);
         } else {
-                ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
-                                        parent, root_objectid, owner,
-                                        offset, BTRFS_DROP_DELAYED_REF, NULL);
+                ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr,
+                                                num_bytes,
+                                                parent, root_objectid, owner,
+                                                offset, BTRFS_DROP_DELAYED_REF,
+                                                NULL, for_cow);
                 BUG_ON(ret);
         }
         return ret;
@@ -5877,9 +5961,10 @@ int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
 
         BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
 
-        ret = btrfs_add_delayed_data_ref(trans, ins->objectid, ins->offset,
-                                         0, root_objectid, owner, offset,
-                                         BTRFS_ADD_DELAYED_EXTENT, NULL);
+        ret = btrfs_add_delayed_data_ref(root->fs_info, trans, ins->objectid,
+                                         ins->offset, 0,
+                                         root_objectid, owner, offset,
+                                         BTRFS_ADD_DELAYED_EXTENT, NULL, 0);
         return ret;
 }
 
@@ -6049,7 +6134,7 @@ struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
                                         struct btrfs_root *root, u32 blocksize,
                                         u64 parent, u64 root_objectid,
                                         struct btrfs_disk_key *key, int level,
-                                        u64 hint, u64 empty_size)
+                                        u64 hint, u64 empty_size, int for_cow)
 {
         struct btrfs_key ins;
         struct btrfs_block_rsv *block_rsv;
@@ -6093,10 +6178,11 @@ struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
                 extent_op->update_flags = 1;
                 extent_op->is_data = 0;
 
-                ret = btrfs_add_delayed_tree_ref(trans, ins.objectid,
+                ret = btrfs_add_delayed_tree_ref(root->fs_info, trans,
+                                        ins.objectid,
                                         ins.offset, parent, root_objectid,
                                         level, BTRFS_ADD_DELAYED_EXTENT,
-                                        extent_op);
+                                        extent_op, for_cow);
                 BUG_ON(ret);
         }
         return buf;
@@ -6113,6 +6199,7 @@ struct walk_control {
         int keep_locks;
         int reada_slot;
         int reada_count;
+        int for_reloc;
 };
 
 #define DROP_REFERENCE  1
@@ -6251,9 +6338,9 @@ static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
         /* wc->stage == UPDATE_BACKREF */
         if (!(wc->flags[level] & flag)) {
                 BUG_ON(!path->locks[level]);
-                ret = btrfs_inc_ref(trans, root, eb, 1);
+                ret = btrfs_inc_ref(trans, root, eb, 1, wc->for_reloc);
                 BUG_ON(ret);
-                ret = btrfs_dec_ref(trans, root, eb, 0);
+                ret = btrfs_dec_ref(trans, root, eb, 0, wc->for_reloc);
                 BUG_ON(ret);
                 ret = btrfs_set_disk_extent_flags(trans, root, eb->start,
                                                   eb->len, flag, 0);
@@ -6397,7 +6484,7 @@ skip:
                 }
 
                 ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
-                                        root->root_key.objectid, level - 1, 0);
+                                root->root_key.objectid, level - 1, 0, 0);
                 BUG_ON(ret);
         }
         btrfs_tree_unlock(next);
@@ -6471,9 +6558,11 @@ static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
         if (wc->refs[level] == 1) {
                 if (level == 0) {
                         if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
-                                ret = btrfs_dec_ref(trans, root, eb, 1);
+                                ret = btrfs_dec_ref(trans, root, eb, 1,
+                                                    wc->for_reloc);
                         else
-                                ret = btrfs_dec_ref(trans, root, eb, 0);
+                                ret = btrfs_dec_ref(trans, root, eb, 0,
+                                                    wc->for_reloc);
                         BUG_ON(ret);
                 }
                 /* make block locked assertion in clean_tree_block happy */
@@ -6500,7 +6589,7 @@ static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
                                btrfs_header_owner(path->nodes[level + 1]));
         }
 
-        btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1);
+        btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1, 0);
 out:
         wc->refs[level] = 0;
         wc->flags[level] = 0;
@@ -6584,7 +6673,8 @@ static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
  * blocks are properly updated.
  */
 void btrfs_drop_snapshot(struct btrfs_root *root,
-                         struct btrfs_block_rsv *block_rsv, int update_ref)
+                         struct btrfs_block_rsv *block_rsv, int update_ref,
+                         int for_reloc)
 {
         struct btrfs_path *path;
         struct btrfs_trans_handle *trans;
@@ -6672,6 +6762,7 @@ void btrfs_drop_snapshot(struct btrfs_root *root,
         wc->stage = DROP_REFERENCE;
         wc->update_ref = update_ref;
         wc->keep_locks = 0;
+        wc->for_reloc = for_reloc;
         wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
 
         while (1) {
@@ -6756,6 +6847,7 @@ out:
  * drop subtree rooted at tree block 'node'.
  *
  * NOTE: this function will unlock and release tree block 'node'
+ * only used by relocation code
  */
 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
                         struct btrfs_root *root,
@@ -6800,6 +6892,7 @@ int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
         wc->stage = DROP_REFERENCE;
         wc->update_ref = 0;
         wc->keep_locks = 1;
+        wc->for_reloc = 1;
         wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
 
         while (1) {