1 files changed, 70 insertions, 90 deletions

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 7dc36fab4afc..81376d94cd3c 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -55,6 +55,7 @@ static noinline int join_transaction(struct btrfs_root *root, int nofail)
         struct btrfs_transaction *cur_trans;
 
         spin_lock(&root->fs_info->trans_lock);
+loop:
         if (root->fs_info->trans_no_join) {
                 if (!nofail) {
                         spin_unlock(&root->fs_info->trans_lock);
@@ -75,16 +76,18 @@ static noinline int join_transaction(struct btrfs_root *root, int nofail)
         cur_trans = kmem_cache_alloc(btrfs_transaction_cachep, GFP_NOFS);
         if (!cur_trans)
                 return -ENOMEM;
+
         spin_lock(&root->fs_info->trans_lock);
         if (root->fs_info->running_transaction) {
+                /*
+                 * someone started a transaction after we unlocked.  Make sure
+                 * to redo the trans_no_join checks above
+                 */
                 kmem_cache_free(btrfs_transaction_cachep, cur_trans);
                 cur_trans = root->fs_info->running_transaction;
-                atomic_inc(&cur_trans->use_count);
-                atomic_inc(&cur_trans->num_writers);
-                cur_trans->num_joined++;
-                spin_unlock(&root->fs_info->trans_lock);
-                return 0;
+                goto loop;
         }
+
         atomic_set(&cur_trans->num_writers, 1);
         cur_trans->num_joined = 0;
         init_waitqueue_head(&cur_trans->writer_wait);
@@ -275,7 +278,7 @@ static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
          */
         if (num_items > 0 && root != root->fs_info->chunk_root) {
                 num_bytes = btrfs_calc_trans_metadata_size(root, num_items);
-                ret = btrfs_block_rsv_add(NULL, root,
+                ret = btrfs_block_rsv_add(root,
                                           &root->fs_info->trans_block_rsv,
                                           num_bytes);
                 if (ret)
@@ -418,8 +421,8 @@ static int should_end_transaction(struct btrfs_trans_handle *trans,
                                   struct btrfs_root *root)
 {
         int ret;
-        ret = btrfs_block_rsv_check(trans, root,
-                                    &root->fs_info->global_block_rsv, 0, 5);
+
+        ret = btrfs_block_rsv_check(root, &root->fs_info->global_block_rsv, 5);
         return ret ? 1 : 0;
 }
 
@@ -427,17 +430,26 @@ int btrfs_should_end_transaction(struct btrfs_trans_handle *trans,
                                  struct btrfs_root *root)
 {
         struct btrfs_transaction *cur_trans = trans->transaction;
+        struct btrfs_block_rsv *rsv = trans->block_rsv;
         int updates;
 
         smp_mb();
         if (cur_trans->blocked || cur_trans->delayed_refs.flushing)
                 return 1;
 
+        /*
+         * We need to do this in case we're deleting csums so the global block
+         * rsv get's used instead of the csum block rsv.
+         */
+        trans->block_rsv = NULL;
+
         updates = trans->delayed_ref_updates;
         trans->delayed_ref_updates = 0;
         if (updates)
                 btrfs_run_delayed_refs(trans, root, updates);
 
+        trans->block_rsv = rsv;
+
         return should_end_transaction(trans, root);
 }
 
@@ -453,6 +465,8 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
                 return 0;
         }
 
+        btrfs_trans_release_metadata(trans, root);
+        trans->block_rsv = NULL;
         while (count < 4) {
                 unsigned long cur = trans->delayed_ref_updates;
                 trans->delayed_ref_updates = 0;
@@ -473,8 +487,6 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
                 count++;
         }
 
-        btrfs_trans_release_metadata(trans, root);
-
         if (lock && !atomic_read(&root->fs_info->open_ioctl_trans) &&
             should_end_transaction(trans, root)) {
                 trans->transaction->blocked = 1;
@@ -562,50 +574,21 @@ int btrfs_end_transaction_dmeta(struct btrfs_trans_handle *trans,
 int btrfs_write_marked_extents(struct btrfs_root *root,
                                struct extent_io_tree *dirty_pages, int mark)
 {
-        int ret;
         int err = 0;
         int werr = 0;
-        struct page *page;
-        struct inode *btree_inode = root->fs_info->btree_inode;
+        struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
         u64 start = 0;
         u64 end;
-        unsigned long index;
-
-        while (1) {
-                ret = find_first_extent_bit(dirty_pages, start, &start, &end,
-                                            mark);
-                if (ret)
-                        break;
-                while (start <= end) {
-                        cond_resched();
-
-                        index = start >> PAGE_CACHE_SHIFT;
-                        start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
-                        page = find_get_page(btree_inode->i_mapping, index);
-                        if (!page)
-                                continue;
-
-                        btree_lock_page_hook(page);
-                        if (!page->mapping) {
-                                unlock_page(page);
-                                page_cache_release(page);
-                                continue;
-                        }
 
-                        if (PageWriteback(page)) {
-                                if (PageDirty(page))
-                                        wait_on_page_writeback(page);
-                                else {
-                                        unlock_page(page);
-                                        page_cache_release(page);
-                                        continue;
-                                }
-                        }
-                        err = write_one_page(page, 0);
-                        if (err)
-                                werr = err;
-                        page_cache_release(page);
-                }
+        while (!find_first_extent_bit(dirty_pages, start, &start, &end,
+                                      mark)) {
+                convert_extent_bit(dirty_pages, start, end, EXTENT_NEED_WAIT, mark,
+                                   GFP_NOFS);
+                err = filemap_fdatawrite_range(mapping, start, end);
+                if (err)
+                        werr = err;
+                cond_resched();
+                start = end + 1;
         }
         if (err)
                 werr = err;
@@ -621,39 +604,20 @@ int btrfs_write_marked_extents(struct btrfs_root *root,
 int btrfs_wait_marked_extents(struct btrfs_root *root,
                               struct extent_io_tree *dirty_pages, int mark)
 {
-        int ret;
         int err = 0;
         int werr = 0;
-        struct page *page;
-        struct inode *btree_inode = root->fs_info->btree_inode;
+        struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
         u64 start = 0;
         u64 end;
-        unsigned long index;
-
-        while (1) {
-                ret = find_first_extent_bit(dirty_pages, start, &start, &end,
-                                            mark);
-                if (ret)
-                        break;
 
-                clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS);
-                while (start <= end) {
-                        index = start >> PAGE_CACHE_SHIFT;
-                        start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
-                        page = find_get_page(btree_inode->i_mapping, index);
-                        if (!page)
-                                continue;
-                        if (PageDirty(page)) {
-                                btree_lock_page_hook(page);
-                                wait_on_page_writeback(page);
-                                err = write_one_page(page, 0);
-                                if (err)
-                                        werr = err;
-                        }
-                        wait_on_page_writeback(page);
-                        page_cache_release(page);
-                        cond_resched();
-                }
+        while (!find_first_extent_bit(dirty_pages, start, &start, &end,
+                                      EXTENT_NEED_WAIT)) {
+                clear_extent_bits(dirty_pages, start, end, EXTENT_NEED_WAIT, GFP_NOFS);
+                err = filemap_fdatawait_range(mapping, start, end);
+                if (err)
+                        werr = err;
+                cond_resched();
+                start = end + 1;
         }
         if (err)
                 werr = err;
@@ -673,7 +637,12 @@ int btrfs_write_and_wait_marked_extents(struct btrfs_root *root,
 
         ret = btrfs_write_marked_extents(root, dirty_pages, mark);
         ret2 = btrfs_wait_marked_extents(root, dirty_pages, mark);
-        return ret || ret2;
+
+        if (ret)
+                return ret;
+        if (ret2)
+                return ret2;
+        return 0;
 }
 
 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
@@ -816,6 +785,10 @@ static noinline int commit_fs_roots(struct btrfs_trans_handle *trans,
 
                         btrfs_save_ino_cache(root, trans);
 
+                        /* see comments in should_cow_block() */
+                        root->force_cow = 0;
+                        smp_wmb();
+
                         if (root->commit_root != root->node) {
                                 mutex_lock(&root->fs_commit_mutex);
                                 switch_commit_root(root);
@@ -884,6 +857,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
         struct btrfs_root *tree_root = fs_info->tree_root;
         struct btrfs_root *root = pending->root;
         struct btrfs_root *parent_root;
+        struct btrfs_block_rsv *rsv;
         struct inode *parent_inode;
         struct dentry *parent;
         struct dentry *dentry;
@@ -895,6 +869,8 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
         u64 objectid;
         u64 root_flags;
 
+        rsv = trans->block_rsv;
+
         new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
         if (!new_root_item) {
                 pending->error = -ENOMEM;
@@ -908,11 +884,10 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
         }
 
         btrfs_reloc_pre_snapshot(trans, pending, &to_reserve);
-        btrfs_orphan_pre_snapshot(trans, pending, &to_reserve);
 
         if (to_reserve > 0) {
-                ret = btrfs_block_rsv_add(trans, root, &pending->block_rsv,
-                                          to_reserve);
+                ret = btrfs_block_rsv_add_noflush(root, &pending->block_rsv,
+                                                  to_reserve);
                 if (ret) {
                         pending->error = ret;
                         goto fail;
@@ -976,6 +951,10 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
         btrfs_tree_unlock(old);
         free_extent_buffer(old);
 
+        /* see comments in should_cow_block() */
+        root->force_cow = 1;
+        smp_wmb();
+
         btrfs_set_root_node(new_root_item, tmp);
         /* record when the snapshot was created in key.offset */
         key.offset = trans->transid;
@@ -999,9 +978,9 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
         BUG_ON(IS_ERR(pending->snap));
 
         btrfs_reloc_post_snapshot(trans, pending);
-        btrfs_orphan_post_snapshot(trans, pending);
 fail:
         kfree(new_root_item);
+        trans->block_rsv = rsv;
         btrfs_block_rsv_release(root, &pending->block_rsv, (u64)-1);
         return 0;
 }
@@ -1028,7 +1007,7 @@ static void update_super_roots(struct btrfs_root *root)
         struct btrfs_root_item *root_item;
         struct btrfs_super_block *super;
 
-        super = &root->fs_info->super_copy;
+        super = root->fs_info->super_copy;
 
         root_item = &root->fs_info->chunk_root->root_item;
         super->chunk_root = root_item->bytenr;
@@ -1039,7 +1018,7 @@ static void update_super_roots(struct btrfs_root *root)
         super->root = root_item->bytenr;
         super->generation = root_item->generation;
         super->root_level = root_item->level;
-        if (super->cache_generation != 0 || btrfs_test_opt(root, SPACE_CACHE))
+        if (btrfs_test_opt(root, SPACE_CACHE))
                 super->cache_generation = root_item->generation;
 }
 
@@ -1164,14 +1143,15 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 
         btrfs_run_ordered_operations(root, 0);
 
+        btrfs_trans_release_metadata(trans, root);
+        trans->block_rsv = NULL;
+
         /* make a pass through all the delayed refs we have so far
          * any runnings procs may add more while we are here
          */
         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
@@ -1337,12 +1317,12 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
         update_super_roots(root);
 
         if (!root->fs_info->log_root_recovering) {
-                btrfs_set_super_log_root(&root->fs_info->super_copy, 0);
-                btrfs_set_super_log_root_level(&root->fs_info->super_copy, 0);
+                btrfs_set_super_log_root(root->fs_info->super_copy, 0);
+                btrfs_set_super_log_root_level(root->fs_info->super_copy, 0);
         }
 
-        memcpy(&root->fs_info->super_for_commit, &root->fs_info->super_copy,
-               sizeof(root->fs_info->super_copy));
+        memcpy(root->fs_info->super_for_commit, root->fs_info->super_copy,
+               sizeof(*root->fs_info->super_copy));
 
         trans->transaction->blocked = 0;
         spin_lock(&root->fs_info->trans_lock);