4 files changed, 31 insertions, 20 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 86e84a8579e3..7ce3f83c5dd6 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1011,9 +1011,16 @@ void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
         spin_lock(&em_tree->lock);
         em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
         spin_unlock(&em_tree->lock);
-        if (!em)
+        if (!em) {
+                __unplug_io_fn(bdi, page);
                 return;
+        }
 
+        if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
+                free_extent_map(em);
+                __unplug_io_fn(bdi, page);
+                return;
+        }
         offset = offset - em->start;
         btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
                           em->block_start + offset, page);
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 9965993748d0..e3547a992d5c 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1949,18 +1949,18 @@ printk("2bad mapping end %Lu cur %Lu\n", end, cur);
                                                           cur + iosize - 1);
                 }
                 if (!ret) {
-                        unsigned long nr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
-                        nr -= page->index;
+                        unsigned long pnr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
+                        pnr -= page->index;
                         ret = submit_extent_page(READ, tree, page,
                                          sector, iosize, page_offset,
-                                         bdev, bio, nr,
+                                         bdev, bio, pnr,
                                          end_bio_extent_readpage, mirror_num);
+                        nr++;
                 }
                 if (ret)
                         SetPageError(page);
                 cur = cur + iosize;
                 page_offset += iosize;
-                nr++;
         }
         if (!nr) {
                 if (!PageError(page))
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 28e667052ec3..0e90315ea803 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -611,22 +611,25 @@ int btrfs_readpage_io_hook(struct page *page, u64 start, u64 end)
             btrfs_test_flag(inode, NODATASUM))
                 return 0;
 
+        /*
+         * It is possible there is an ordered extent that has
+         * not yet finished for this range in the file.  If so,
+         * that extent will have a csum cached, and it will insert
+         * the sum after all the blocks in the extent are fully
+         * on disk.  So, look for an ordered extent and use the
+         * sum if found.  We have to do this before looking in the
+         * btree because csum items are pre-inserted based on
+         * the file size.  btrfs_lookup_csum might find an item
+         * that still hasn't been fully filled.
+         */
+        ret = btrfs_find_ordered_sum(inode, start, &csum);
+        if (ret == 0)
+                goto found;
+
+        ret = 0;
         path = btrfs_alloc_path();
-        mutex_lock(&BTRFS_I(inode)->csum_mutex);
         item = btrfs_lookup_csum(NULL, root, path, inode->i_ino, start, 0);
         if (IS_ERR(item)) {
-                /*
-                 * It is possible there is an ordered extent that has
-                 * not yet finished for this range in the file.  If so,
-                 * that extent will have a csum cached, and it will insert
-                 * the sum after all the blocks in the extent are fully
-                 * on disk.  So, look for an ordered extent and use the
-                 * sum if found.
-                 */
-                ret = btrfs_find_ordered_sum(inode, start, &csum);
-                if (ret == 0)
-                        goto found;
-
                 ret = PTR_ERR(item);
                 /* a csum that isn't present is a preallocated region. */
                 if (ret == -ENOENT || ret == -EFBIG)
@@ -641,7 +644,6 @@ int btrfs_readpage_io_hook(struct page *page, u64 start, u64 end)
 found:
         set_state_private(io_tree, start, csum);
 out:
-        mutex_unlock(&BTRFS_I(inode)->csum_mutex);
         if (path)
                 btrfs_free_path(path);
         return ret;
@@ -1375,7 +1377,7 @@ again:
                 }
                 if (!PageUptodate(page)) {
                         ret = -EIO;
-                        goto out;
+                        goto out_unlock;
                 }
         }
         wait_on_page_writeback(page);
@@ -1406,6 +1408,7 @@ again:
         set_page_dirty(page);
         unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
 
+out_unlock:
         unlock_page(page);
         page_cache_release(page);
 out:
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index b695f5b29c45..e42fd233e04c 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -557,6 +557,7 @@ int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u32 *sum)
         }
 out:
         mutex_unlock(&tree->mutex);
+        btrfs_put_ordered_extent(ordered);
         return ret;
 }