1 files changed, 43 insertions, 13 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index f81a48c47fe0..4f8fb1130cf3 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7540,6 +7540,27 @@ static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
         return em;
 }
 
+
+static int btrfs_get_blocks_direct_read(struct extent_map *em,
+                                        struct buffer_head *bh_result,
+                                        struct inode *inode,
+                                        u64 start, u64 len)
+{
+        if (em->block_start == EXTENT_MAP_HOLE ||
+                        test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
+                return -ENOENT;
+
+        len = min(len, em->len - (start - em->start));
+
+        bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
+                inode->i_blkbits;
+        bh_result->b_size = len;
+        bh_result->b_bdev = em->bdev;
+        set_buffer_mapped(bh_result);
+
+        return 0;
+}
+
 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
                                    struct buffer_head *bh_result, int create)
 {
@@ -7608,11 +7629,29 @@ static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
                 goto unlock_err;
         }
 
-        /* Just a good old fashioned hole, return */
-        if (!create && (em->block_start == EXTENT_MAP_HOLE ||
-                        test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
+        if (!create) {
+                ret = btrfs_get_blocks_direct_read(em, bh_result, inode,
+                                                   start, len);
+                /* Can be negative only if we read from a hole */
+                if (ret < 0) {
+                        ret = 0;
+                        free_extent_map(em);
+                        goto unlock_err;
+                }
+                /*
+                 * We need to unlock only the end area that we aren't using.
+                 * The rest is going to be unlocked by the endio routine.
+                 */
+                lockstart = start + bh_result->b_size;
+                if (lockstart < lockend) {
+                        clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
+                                         lockend, unlock_bits, 1, 0,
+                                         &cached_state);
+                } else {
+                        free_extent_state(cached_state);
+                }
                 free_extent_map(em);
-                goto unlock_err;
+                return 0;
         }
 
         /*
@@ -7624,12 +7663,6 @@ static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
          * just use the extent.
          *
          */
-        if (!create) {
-                len = min(len, em->len - (start - em->start));
-                lockstart = start + len;
-                goto unlock;
-        }
-
         if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
             ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
              em->block_start != EXTENT_MAP_HOLE)) {
@@ -7716,10 +7749,7 @@ unlock:
                 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
                                  lockend, unlock_bits, 1, 0,
                                  &cached_state);
-        } else {
-                free_extent_state(cached_state);
         }
-
         free_extent_map(em);
 
         return 0;