1 files changed, 197 insertions, 55 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 359a754c782c..e238a0cdac67 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1568,23 +1568,23 @@ static int remove_extent_backref(struct btrfs_trans_handle *trans,
         return ret;
 }
 
-#ifdef BIO_RW_DISCARD
 static void btrfs_issue_discard(struct block_device *bdev,
                                 u64 start, u64 len)
 {
         blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL,
                              DISCARD_FL_BARRIER);
 }
-#endif
 
 static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
                                 u64 num_bytes)
 {
-#ifdef BIO_RW_DISCARD
         int ret;
         u64 map_length = num_bytes;
         struct btrfs_multi_bio *multi = NULL;
 
+        if (!btrfs_test_opt(root, DISCARD))
+                return 0;
+
         /* Tell the block device(s) that the sectors can be discarded */
         ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
                               bytenr, &map_length, &multi, 0);
@@ -1604,9 +1604,6 @@ static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
         }
 
         return ret;
-#else
-        return 0;
-#endif
 }
 
 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
@@ -2824,14 +2821,17 @@ int btrfs_unreserve_metadata_for_delalloc(struct btrfs_root *root,
                                            num_items);
 
         spin_lock(&meta_sinfo->lock);
-        if (BTRFS_I(inode)->delalloc_reserved_extents <=
-            BTRFS_I(inode)->delalloc_extents) {
+        spin_lock(&BTRFS_I(inode)->accounting_lock);
+        if (BTRFS_I(inode)->reserved_extents <=
+            BTRFS_I(inode)->outstanding_extents) {
+                spin_unlock(&BTRFS_I(inode)->accounting_lock);
                 spin_unlock(&meta_sinfo->lock);
                 return 0;
         }
+        spin_unlock(&BTRFS_I(inode)->accounting_lock);
 
-        BTRFS_I(inode)->delalloc_reserved_extents--;
-        BUG_ON(BTRFS_I(inode)->delalloc_reserved_extents < 0);
+        BTRFS_I(inode)->reserved_extents--;
+        BUG_ON(BTRFS_I(inode)->reserved_extents < 0);
 
         if (meta_sinfo->bytes_delalloc < num_bytes) {
                 bug = true;
@@ -2864,6 +2864,107 @@ static void check_force_delalloc(struct btrfs_space_info *meta_sinfo)
                 meta_sinfo->force_delalloc = 0;
 }
 
+struct async_flush {
+        struct btrfs_root *root;
+        struct btrfs_space_info *info;
+        struct btrfs_work work;
+};
+
+static noinline void flush_delalloc_async(struct btrfs_work *work)
+{
+        struct async_flush *async;
+        struct btrfs_root *root;
+        struct btrfs_space_info *info;
+
+        async = container_of(work, struct async_flush, work);
+        root = async->root;
+        info = async->info;
+
+        btrfs_start_delalloc_inodes(root);
+        wake_up(&info->flush_wait);
+        btrfs_wait_ordered_extents(root, 0);
+
+        spin_lock(&info->lock);
+        info->flushing = 0;
+        spin_unlock(&info->lock);
+        wake_up(&info->flush_wait);
+
+        kfree(async);
+}
+
+static void wait_on_flush(struct btrfs_space_info *info)
+{
+        DEFINE_WAIT(wait);
+        u64 used;
+
+        while (1) {
+                prepare_to_wait(&info->flush_wait, &wait,
+                                TASK_UNINTERRUPTIBLE);
+                spin_lock(&info->lock);
+                if (!info->flushing) {
+                        spin_unlock(&info->lock);
+                        break;
+                }
+
+                used = info->bytes_used + info->bytes_reserved +
+                        info->bytes_pinned + info->bytes_readonly +
+                        info->bytes_super + info->bytes_root +
+                        info->bytes_may_use + info->bytes_delalloc;
+                if (used < info->total_bytes) {
+                        spin_unlock(&info->lock);
+                        break;
+                }
+                spin_unlock(&info->lock);
+                schedule();
+        }
+        finish_wait(&info->flush_wait, &wait);
+}
+
+static void flush_delalloc(struct btrfs_root *root,
+                                 struct btrfs_space_info *info)
+{
+        struct async_flush *async;
+        bool wait = false;
+
+        spin_lock(&info->lock);
+
+        if (!info->flushing) {
+                info->flushing = 1;
+                init_waitqueue_head(&info->flush_wait);
+        } else {
+                wait = true;
+        }
+
+        spin_unlock(&info->lock);
+
+        if (wait) {
+                wait_on_flush(info);
+                return;
+        }
+
+        async = kzalloc(sizeof(*async), GFP_NOFS);
+        if (!async)
+                goto flush;
+
+        async->root = root;
+        async->info = info;
+        async->work.func = flush_delalloc_async;
+
+        btrfs_queue_worker(&root->fs_info->enospc_workers,
+                           &async->work);
+        wait_on_flush(info);
+        return;
+
+flush:
+        btrfs_start_delalloc_inodes(root);
+        btrfs_wait_ordered_extents(root, 0);
+
+        spin_lock(&info->lock);
+        info->flushing = 0;
+        spin_unlock(&info->lock);
+        wake_up(&info->flush_wait);
+}
+
 static int maybe_allocate_chunk(struct btrfs_root *root,
                                  struct btrfs_space_info *info)
 {
@@ -2894,7 +2995,7 @@ static int maybe_allocate_chunk(struct btrfs_root *root,
         if (!info->allocating_chunk) {
                 info->force_alloc = 1;
                 info->allocating_chunk = 1;
-                init_waitqueue_head(&info->wait);
+                init_waitqueue_head(&info->allocate_wait);
         } else {
                 wait = true;
         }
@@ -2902,7 +3003,7 @@ static int maybe_allocate_chunk(struct btrfs_root *root,
         spin_unlock(&info->lock);
 
         if (wait) {
-                wait_event(info->wait,
+                wait_event(info->allocate_wait,
                            !info->allocating_chunk);
                 return 1;
         }
@@ -2923,7 +3024,7 @@ out:
         spin_lock(&info->lock);
         info->allocating_chunk = 0;
         spin_unlock(&info->lock);
-        wake_up(&info->wait);
+        wake_up(&info->allocate_wait);
 
         if (ret)
                 return 0;
@@ -2981,21 +3082,20 @@ again:
                         filemap_flush(inode->i_mapping);
                         goto again;
                 } else if (flushed == 3) {
-                        btrfs_start_delalloc_inodes(root);
-                        btrfs_wait_ordered_extents(root, 0);
+                        flush_delalloc(root, meta_sinfo);
                         goto again;
                 }
                 spin_lock(&meta_sinfo->lock);
                 meta_sinfo->bytes_delalloc -= num_bytes;
                 spin_unlock(&meta_sinfo->lock);
                 printk(KERN_ERR "enospc, has %d, reserved %d\n",
-                       BTRFS_I(inode)->delalloc_extents,
-                       BTRFS_I(inode)->delalloc_reserved_extents);
+                       BTRFS_I(inode)->outstanding_extents,
+                       BTRFS_I(inode)->reserved_extents);
                 dump_space_info(meta_sinfo, 0, 0);
                 return -ENOSPC;
         }
 
-        BTRFS_I(inode)->delalloc_reserved_extents++;
+        BTRFS_I(inode)->reserved_extents++;
         check_force_delalloc(meta_sinfo);
         spin_unlock(&meta_sinfo->lock);
 
@@ -3094,8 +3194,7 @@ again:
                 }
 
                 if (retries == 2) {
-                        btrfs_start_delalloc_inodes(root);
-                        btrfs_wait_ordered_extents(root, 0);
+                        flush_delalloc(root, meta_sinfo);
                         goto again;
                 }
                 spin_lock(&meta_sinfo->lock);
@@ -3588,6 +3687,14 @@ static int pin_down_bytes(struct btrfs_trans_handle *trans,
         if (is_data)
                 goto pinit;
 
+        /*
+         * discard is sloooow, and so triggering discards on
+         * individual btree blocks isn't a good plan.  Just
+         * pin everything in discard mode.
+         */
+        if (btrfs_test_opt(root, DISCARD))
+                goto pinit;
+
         buf = btrfs_find_tree_block(root, bytenr, num_bytes);
         if (!buf)
                 goto pinit;
@@ -4029,6 +4136,7 @@ static noinline int find_free_extent(struct btrfs_trans_handle *trans,
         int loop = 0;
         bool found_uncached_bg = false;
         bool failed_cluster_refill = false;
+        bool failed_alloc = false;
 
         WARN_ON(num_bytes < root->sectorsize);
         btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
@@ -4233,14 +4341,23 @@ refill_cluster:
 
                 offset = btrfs_find_space_for_alloc(block_group, search_start,
                                                     num_bytes, empty_size);
-                if (!offset && (cached || (!cached &&
-                                           loop == LOOP_CACHING_NOWAIT))) {
-                        goto loop;
-                } else if (!offset && (!cached &&
-                                       loop > LOOP_CACHING_NOWAIT)) {
+                /*
+                 * If we didn't find a chunk, and we haven't failed on this
+                 * block group before, and this block group is in the middle of
+                 * caching and we are ok with waiting, then go ahead and wait
+                 * for progress to be made, and set failed_alloc to true.
+                 *
+                 * If failed_alloc is true then we've already waited on this
+                 * block group once and should move on to the next block group.
+                 */
+                if (!offset && !failed_alloc && !cached &&
+                    loop > LOOP_CACHING_NOWAIT) {
                         wait_block_group_cache_progress(block_group,
-                                        num_bytes + empty_size);
+                                                num_bytes + empty_size);
+                        failed_alloc = true;
                         goto have_block_group;
+                } else if (!offset) {
+                        goto loop;
                 }
 checks:
                 search_start = stripe_align(root, offset);
@@ -4288,6 +4405,7 @@ checks:
                 break;
 loop:
                 failed_cluster_refill = false;
+                failed_alloc = false;
                 btrfs_put_block_group(block_group);
         }
         up_read(&space_info->groups_sem);
@@ -4799,6 +4917,7 @@ static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
         u64 bytenr;
         u64 generation;
         u64 refs;
+        u64 flags;
         u64 last = 0;
         u32 nritems;
         u32 blocksize;
@@ -4836,15 +4955,19 @@ static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
                     generation <= root->root_key.offset)
                         continue;
 
+                /* We don't lock the tree block, it's OK to be racy here */
+                ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize,
+                                               &refs, &flags);
+                BUG_ON(ret);
+                BUG_ON(refs == 0);
+
                 if (wc->stage == DROP_REFERENCE) {
-                        ret = btrfs_lookup_extent_info(trans, root,
-                                                bytenr, blocksize,
-                                                &refs, NULL);
-                        BUG_ON(ret);
-                        BUG_ON(refs == 0);
                         if (refs == 1)
                                 goto reada;
 
+                        if (wc->level == 1 &&
+                            (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
+                                continue;
                         if (!wc->update_ref ||
                             generation <= root->root_key.offset)
                                 continue;
@@ -4853,6 +4976,10 @@ static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
                                                   &wc->update_progress);
                         if (ret < 0)
                                 continue;
+                } else {
+                        if (wc->level == 1 &&
+                            (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
+                                continue;
                 }
 reada:
                 ret = readahead_tree_block(root, bytenr, blocksize,
@@ -4876,7 +5003,7 @@ reada:
 static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
                                    struct btrfs_root *root,
                                    struct btrfs_path *path,
-                                   struct walk_control *wc)
+                                   struct walk_control *wc, int lookup_info)
 {
         int level = wc->level;
         struct extent_buffer *eb = path->nodes[level];
@@ -4891,8 +5018,9 @@ static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
          * when reference count of tree block is 1, it won't increase
          * again. once full backref flag is set, we never clear it.
          */
-        if ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
-            (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag))) {
+        if (lookup_info &&
+            ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
+             (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) {
                 BUG_ON(!path->locks[level]);
                 ret = btrfs_lookup_extent_info(trans, root,
                                                eb->start, eb->len,
@@ -4953,7 +5081,7 @@ static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
 static noinline int do_walk_down(struct btrfs_trans_handle *trans,
                                  struct btrfs_root *root,
                                  struct btrfs_path *path,
-                                 struct walk_control *wc)
+                                 struct walk_control *wc, int *lookup_info)
 {
         u64 bytenr;
         u64 generation;
@@ -4973,8 +5101,10 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
          * for the subtree
          */
         if (wc->stage == UPDATE_BACKREF &&
-            generation <= root->root_key.offset)
+            generation <= root->root_key.offset) {
+                *lookup_info = 1;
                 return 1;
+        }
 
         bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
         blocksize = btrfs_level_size(root, level - 1);
@@ -4987,14 +5117,19 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
         btrfs_tree_lock(next);
         btrfs_set_lock_blocking(next);
 
-        if (wc->stage == DROP_REFERENCE) {
-                ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize,
-                                               &wc->refs[level - 1],
-                                               &wc->flags[level - 1]);
-                BUG_ON(ret);
-                BUG_ON(wc->refs[level - 1] == 0);
+        ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize,
+                                       &wc->refs[level - 1],
+                                       &wc->flags[level - 1]);
+        BUG_ON(ret);
+        BUG_ON(wc->refs[level - 1] == 0);
+        *lookup_info = 0;
 
+        if (wc->stage == DROP_REFERENCE) {
                 if (wc->refs[level - 1] > 1) {
+                        if (level == 1 &&
+                            (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
+                                goto skip;
+
                         if (!wc->update_ref ||
                             generation <= root->root_key.offset)
                                 goto skip;
@@ -5008,12 +5143,17 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
                         wc->stage = UPDATE_BACKREF;
                         wc->shared_level = level - 1;
                 }
+        } else {
+                if (level == 1 &&
+                    (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
+                        goto skip;
         }
 
         if (!btrfs_buffer_uptodate(next, generation)) {
                 btrfs_tree_unlock(next);
                 free_extent_buffer(next);
                 next = NULL;
+                *lookup_info = 1;
         }
 
         if (!next) {
@@ -5036,21 +5176,22 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
 skip:
         wc->refs[level - 1] = 0;
         wc->flags[level - 1] = 0;
+        if (wc->stage == DROP_REFERENCE) {
+                if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
+                        parent = path->nodes[level]->start;
+                } else {
+                        BUG_ON(root->root_key.objectid !=
+                               btrfs_header_owner(path->nodes[level]));
+                        parent = 0;
+                }
 
-        if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
-                parent = path->nodes[level]->start;
-        } else {
-                BUG_ON(root->root_key.objectid !=
-                       btrfs_header_owner(path->nodes[level]));
-                parent = 0;
+                ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
+                                        root->root_key.objectid, level - 1, 0);
+                BUG_ON(ret);
         }
-
-        ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
-                                root->root_key.objectid, level - 1, 0);
-        BUG_ON(ret);
-
         btrfs_tree_unlock(next);
         free_extent_buffer(next);
+        *lookup_info = 1;
         return 1;
 }
 
@@ -5164,6 +5305,7 @@ static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
                                    struct walk_control *wc)
 {
         int level = wc->level;
+        int lookup_info = 1;
         int ret;
 
         while (level >= 0) {
@@ -5171,14 +5313,14 @@ static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
                     btrfs_header_nritems(path->nodes[level]))
                         break;
 
-                ret = walk_down_proc(trans, root, path, wc);
+                ret = walk_down_proc(trans, root, path, wc, lookup_info);
                 if (ret > 0)
                         break;
 
                 if (level == 0)
                         break;
 
-                ret = do_walk_down(trans, root, path, wc);
+                ret = do_walk_down(trans, root, path, wc, &lookup_info);
                 if (ret > 0) {
                         path->slots[level]++;
                         continue;