Btrfs: Data ordered fixes

* In btrfs_delete_inode, wait for ordered extents after calling
truncate_inode_pages.  This is much faster, and more correct

* Properly clear our the PageChecked bit everywhere we redirty the page.

* Change the writepage fixup handler to lock the page range and check to
see if an ordered extent had been inserted since the improperly dirtied
page was discovered

* Wait for ordered extents outside the transaction.  This isn't required
for locking rules but does improve transaction latencies

* Reduce contention on the alloc_mutex by dropping it while incrementing
refs on a node/leaf and while dropping refs on a leaf.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

4 files changed, 43 insertions, 10 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index be2aef1cb7ae..ccd49322f793 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -934,7 +934,6 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
         if (!root->ref_cows)
                 return 0;
 
-        mutex_lock(&root->fs_info->alloc_mutex);
         level = btrfs_header_level(buf);
         nritems = btrfs_header_nritems(buf);
         for (i = 0; i < nritems; i++) {
@@ -951,29 +950,36 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                         disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
                         if (disk_bytenr == 0)
                                 continue;
+
+                        mutex_lock(&root->fs_info->alloc_mutex);
                         ret = __btrfs_inc_extent_ref(trans, root, disk_bytenr,
                                     btrfs_file_extent_disk_num_bytes(buf, fi),
                                     root->root_key.objectid, trans->transid,
                                     key.objectid, key.offset);
+                        mutex_unlock(&root->fs_info->alloc_mutex);
                         if (ret) {
                                 faili = i;
+                                WARN_ON(1);
                                 goto fail;
                         }
                 } else {
                         bytenr = btrfs_node_blockptr(buf, i);
                         btrfs_node_key_to_cpu(buf, &key, i);
+
+                        mutex_lock(&root->fs_info->alloc_mutex);
                         ret = __btrfs_inc_extent_ref(trans, root, bytenr,
                                            btrfs_level_size(root, level - 1),
                                            root->root_key.objectid,
                                            trans->transid,
                                            level - 1, key.objectid);
+                        mutex_unlock(&root->fs_info->alloc_mutex);
                         if (ret) {
                                 faili = i;
+                                WARN_ON(1);
                                 goto fail;
                         }
                 }
         }
-        mutex_unlock(&root->fs_info->alloc_mutex);
         return 0;
 fail:
         WARN_ON(1);
@@ -1004,7 +1010,6 @@ fail:
                 }
         }
 #endif
-        mutex_unlock(&root->fs_info->alloc_mutex);
         return ret;
 }
 
@@ -2180,6 +2185,8 @@ static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans,
         leaf_owner = btrfs_header_owner(leaf);
         leaf_generation = btrfs_header_generation(leaf);
 
+        mutex_unlock(&root->fs_info->alloc_mutex);
+
         for (i = 0; i < nritems; i++) {
                 u64 disk_bytenr;
 
@@ -2197,12 +2204,17 @@ static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans,
                 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
                 if (disk_bytenr == 0)
                         continue;
+
+                mutex_lock(&root->fs_info->alloc_mutex);
                 ret = __btrfs_free_extent(trans, root, disk_bytenr,
                                 btrfs_file_extent_disk_num_bytes(leaf, fi),
                                 leaf_owner, leaf_generation,
                                 key.objectid, key.offset, 0);
+                mutex_unlock(&root->fs_info->alloc_mutex);
                 BUG_ON(ret);
         }
+
+        mutex_lock(&root->fs_info->alloc_mutex);
         return 0;
 }
 
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index eccdb9562ba8..591a30208acd 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -75,6 +75,7 @@ static void btrfs_drop_pages(struct page **pages, size_t num_pages)
         for (i = 0; i < num_pages; i++) {
                 if (!pages[i])
                         break;
+                ClearPageChecked(pages[i]);
                 unlock_page(pages[i]);
                 mark_page_accessed(pages[i]);
                 page_cache_release(pages[i]);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 50ee4befac8e..8fb6dc25e7a5 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -418,7 +418,7 @@ void btrfs_writepage_fixup_worker(struct btrfs_work *work)
 
         fixup = container_of(work, struct btrfs_writepage_fixup, work);
         page = fixup->page;
-
+again:
         lock_page(page);
         if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
                 ClearPageChecked(page);
@@ -430,9 +430,21 @@ void btrfs_writepage_fixup_worker(struct btrfs_work *work)
         page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
 
         lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end, GFP_NOFS);
-        ordered = btrfs_lookup_ordered_extent(inode, page_start);
-        if (ordered)
+
+        /* already ordered? We're done */
+        if (test_range_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
+                             EXTENT_ORDERED, 0)) {
                 goto out;
+        }
+
+        ordered = btrfs_lookup_ordered_extent(inode, page_start);
+        if (ordered) {
+                unlock_extent(&BTRFS_I(inode)->io_tree, page_start,
+                              page_end, GFP_NOFS);
+                unlock_page(page);
+                btrfs_start_ordered_extent(inode, ordered, 1);
+                goto again;
+        }
 
         set_extent_delalloc(&BTRFS_I(inode)->io_tree, page_start, page_end,
                             GFP_NOFS);
@@ -1465,11 +1477,11 @@ void btrfs_delete_inode(struct inode *inode)
         unsigned long nr;
         int ret;
 
-        btrfs_wait_ordered_range(inode, 0, (u64)-1);
         truncate_inode_pages(&inode->i_data, 0);
         if (is_bad_inode(inode)) {
                 goto no_delete;
         }
+        btrfs_wait_ordered_range(inode, 0, (u64)-1);
 
         btrfs_i_size_write(inode, 0);
         trans = btrfs_start_transaction(root, 1);
@@ -2707,6 +2719,7 @@ static void btrfs_invalidatepage(struct page *page, unsigned long offset)
                  1, 1, GFP_NOFS);
         __btrfs_releasepage(page, GFP_NOFS);
 
+        ClearPageChecked(page);
         if (PagePrivate(page)) {
                 invalidate_extent_lru(tree, page_offset(page),
                                       PAGE_CACHE_SIZE);
@@ -2818,10 +2831,10 @@ static void btrfs_truncate(struct inode *inode)
                 return;
 
         btrfs_truncate_page(inode->i_mapping, inode->i_size);
+        btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
 
         trans = btrfs_start_transaction(root, 1);
         btrfs_set_trans_block_group(trans, inode);
-        btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
         btrfs_i_size_write(inode, inode->i_size);
 
         /* FIXME, add redo link to tree so we don't leak on crash */
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index c2b4a9c4ddb6..0d87795fdd8f 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -336,7 +336,7 @@ void btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
                 orig_end = start + len - 1;
                 wait_end = orig_end;
         }
-
+again:
         /* start IO across the range first to instantiate any delalloc
          * extents
          */
@@ -369,6 +369,14 @@ void btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
                         break;
                 end--;
         }
+        if (test_range_bit(&BTRFS_I(inode)->io_tree, start, orig_end,
+                           EXTENT_ORDERED | EXTENT_DELALLOC, 0)) {
+                printk("inode %lu still ordered or delalloc after wait "
+                       "%llu %llu\n", inode->i_ino,
+                       (unsigned long long)start,
+                       (unsigned long long)orig_end);
+                goto again;
+        }
 }
 
 /*
@@ -545,7 +553,6 @@ int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u32 *sum)
                         sector_sums = &ordered_sum->sums;
                         for (i = 0; i < num_sectors; i++) {
                                 if (sector_sums[i].offset == offset) {
-printk("find ordered sum inode %lu offset %Lu\n", inode->i_ino, offset);
                                         *sum = sector_sums[i].sum;
                                         ret = 0;
                                         goto out;