Btrfs: use the commit_root for reading free_space_inode crcs

[pandora-kernel.git] / fs / btrfs / file-item.c

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 90d4ee5..08bcfa9 100644 (file)
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -177,6 +177,15 @@ static int __btrfs_lookup_bio_sums(struct btrfs_root *root,
 
        WARN_ON(bio->bi_vcnt <= 0);
 
+       /*
+        * the free space stuff is only read when it hasn't been
+        * updated in the current transaction.  So, we can safely
+        * read from the commit root and sidestep a nasty deadlock
+        * between reading the free space cache and updating the csum tree.
+        */
+       if (btrfs_is_free_space_inode(root, inode))
+               path->search_commit_root = 1;
+
        disk_bytenr = (u64)bio->bi_sector << 9;
        if (dio)
                offset = logical_offset;
@@ -664,10 +673,6 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
        struct btrfs_sector_sum *sector_sum;
        u32 nritems;
        u32 ins_size;
-       char *eb_map;
-       char *eb_token;
-       unsigned long map_len;
-       unsigned long map_start;
        u16 csum_size =
                btrfs_super_csum_size(&root->fs_info->super_copy);
 
@@ -814,30 +819,9 @@ found:
        item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
        item_end = (struct btrfs_csum_item *)((unsigned char *)item_end +
                                      btrfs_item_size_nr(leaf, path->slots[0]));
-       eb_token = NULL;
 next_sector:
 
-       if (!eb_token ||
-          (unsigned long)item + csum_size >= map_start + map_len) {
-               int err;
-
-               if (eb_token)
-                       unmap_extent_buffer(leaf, eb_token, KM_USER1);
-               eb_token = NULL;
-               err = map_private_extent_buffer(leaf, (unsigned long)item,
-                                               csum_size,
-                                               &eb_token, &eb_map,
-                                               &map_start, &map_len, KM_USER1);
-               if (err)
-                       eb_token = NULL;
-       }
-       if (eb_token) {
-               memcpy(eb_token + ((unsigned long)item & (PAGE_CACHE_SIZE - 1)),
-                      &sector_sum->sum, csum_size);
-       } else {
-               write_extent_buffer(leaf, &sector_sum->sum,
-                                   (unsigned long)item, csum_size);
-       }
+       write_extent_buffer(leaf, &sector_sum->sum, (unsigned long)item, csum_size);
 
        total_bytes += root->sectorsize;
        sector_sum++;
@@ -850,10 +834,7 @@ next_sector:
                        goto next_sector;
                }
        }
-       if (eb_token) {
-               unmap_extent_buffer(leaf, eb_token, KM_USER1);
-               eb_token = NULL;
-       }
+
        btrfs_mark_buffer_dirty(path->nodes[0]);
        if (total_bytes < sums->len) {
                btrfs_release_path(path);