Eric Lee / smarc-ti-linux-kernel

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Commit 8ca15e05e6ac2745725d2d62394cfbe4ac335e84

Authored by Josef Bacik
Committed by Chris Mason
1 parent b76bb70136
Exists in master and in 20 other branches dlt-processor-sdk-linux-03.00.00.04, newt-ti-linux-3.12.y, processor-sdk-linux-01.00.00, processor-sdk-linux-02.00.01, smarc-ti-linux-3.12.10, smarc-ti-linux-3.12.y, smarc-ti-linux-3.14.y, smarc-ti-linux-3.15.y, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04, ti-linux-3.12.y, ti-linux-3.14.y, ti-linux-3.15.y, ti-lsk-linux-4.1.y

Btrfs: fix backref walking when we hit a compressed extent 

If you do btrfs inspect-internal logical-resolve on a compressed extent that has
been partly overwritten it won't find anything.  This is because we try and
match the extent offset we've searched for based on the extent offset in the
data extent entry.  However this doesn't work for compressed extents because the
offsets are for the uncompressed size, not the compressed size.  So instead only
do this check if we are not compressed, that way we can get an actual entry for
the physical offset rather than nothing for compressed.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

Showing 1 changed file with 15 additions and 8 deletions Side-by-side Diff

... ... @@ -36,24 +36,31 @@
36 36 u64 extent_item_pos,
37 37 struct extent_inode_elem **eie)
38 38 {
39   - u64 data_offset;
40   - u64 data_len;
  39 + u64 offset = 0;
41 40 struct extent_inode_elem *e;
42 41  
43   - data_offset = btrfs_file_extent_offset(eb, fi);
44   - data_len = btrfs_file_extent_num_bytes(eb, fi);
  42 + if (!btrfs_file_extent_compression(eb, fi) &&
  43 + !btrfs_file_extent_encryption(eb, fi) &&
  44 + !btrfs_file_extent_other_encoding(eb, fi)) {
  45 + u64 data_offset;
  46 + u64 data_len;
45 47  
46   - if (extent_item_pos < data_offset ||
47   - extent_item_pos >= data_offset + data_len)
48   - return 1;
  48 + data_offset = btrfs_file_extent_offset(eb, fi);
  49 + data_len = btrfs_file_extent_num_bytes(eb, fi);
49 50  
  51 + if (extent_item_pos < data_offset ||
  52 + extent_item_pos >= data_offset + data_len)
  53 + return 1;
  54 + offset = extent_item_pos - data_offset;
  55 + }
  56 +
50 57 e = kmalloc(sizeof(*e), GFP_NOFS);
51 58 if (!e)
52 59 return -ENOMEM;
53 60  
54 61 e->next = *eie;
55 62 e->inum = key->objectid;
56   - e->offset = key->offset + (extent_item_pos - data_offset);
  63 + e->offset = key->offset + offset;
57 64 *eie = e;
58 65  
59 66 return 0;