Btrfs: fix backref walking when we hit a compressed extent

[linux-imx.git] / fs / btrfs / backref.c

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index eaf133384a8f97497098ab82cc94a67862116705..30dbe1c618577bcfd7c7f47f3403845d35b7ee91 100644 (file)
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -36,16 +36,23 @@ static int check_extent_in_eb(struct btrfs_key *key, struct extent_buffer *eb,
                                u64 extent_item_pos,
                                struct extent_inode_elem **eie)
 {
-       u64 data_offset;
-       u64 data_len;
+       u64 offset = 0;
        struct extent_inode_elem *e;
 
-       data_offset = btrfs_file_extent_offset(eb, fi);
-       data_len = btrfs_file_extent_num_bytes(eb, fi);
+       if (!btrfs_file_extent_compression(eb, fi) &&
+           !btrfs_file_extent_encryption(eb, fi) &&
+           !btrfs_file_extent_other_encoding(eb, fi)) {
+               u64 data_offset;
+               u64 data_len;
 
-       if (extent_item_pos < data_offset ||
-           extent_item_pos >= data_offset + data_len)
-               return 1;
+               data_offset = btrfs_file_extent_offset(eb, fi);
+               data_len = btrfs_file_extent_num_bytes(eb, fi);
+
+               if (extent_item_pos < data_offset ||
+                   extent_item_pos >= data_offset + data_len)
+                       return 1;
+               offset = extent_item_pos - data_offset;
+       }
 
        e = kmalloc(sizeof(*e), GFP_NOFS);
        if (!e)
@@ -53,7 +60,7 @@ static int check_extent_in_eb(struct btrfs_key *key, struct extent_buffer *eb,
 
        e->next = *eie;
        e->inum = key->objectid;
-       e->offset = key->offset + (extent_item_pos - data_offset);
+       e->offset = key->offset + offset;
        *eie = e;
 
        return 0;