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| author | Liu Bo <liubo2009@cn.fujitsu.com> | 2012-04-12 16:03:56 -0400 |
|---|---|---|
| committer | Chris Mason <chris.mason@oracle.com> | 2012-04-12 16:03:56 -0400 |
| commit | b89203f74bdfcb15407d54d3f257b16a2ea19e62 (patch) | |
| tree | a0cbfbc0bf259b4382b881a9108b21dc88525389 | |
| parent | d95603b262edb53d6016a8df0c150371d4d61e67 (diff) | |
| download | linux-b89203f74bdfcb15407d54d3f257b16a2ea19e62.tar.bz2 | |
Btrfs: fix eof while discarding extents
We miscalculate the length of extents we're discarding, and it leads to
an eof of device.
Reported-by: Daniel Blueman <daniel@quora.org>
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
| -rw-r--r-- | fs/btrfs/volumes.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index a872b48be0ae..759d02486d7c 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -3833,6 +3833,7 @@ static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw, int sub_stripes = 0; u64 stripes_per_dev = 0; u32 remaining_stripes = 0; + u32 last_stripe = 0; if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) { @@ -3846,6 +3847,8 @@ static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw, stripe_nr_orig, factor, &remaining_stripes); + div_u64_rem(stripe_nr_end - 1, factor, &last_stripe); + last_stripe *= sub_stripes; } for (i = 0; i < num_stripes; i++) { @@ -3858,16 +3861,29 @@ static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw, BTRFS_BLOCK_GROUP_RAID10)) { bbio->stripes[i].length = stripes_per_dev * map->stripe_len; + if (i / sub_stripes < remaining_stripes) bbio->stripes[i].length += map->stripe_len; + + /* + * Special for the first stripe and + * the last stripe: + * + * |-------|...|-------| + * |----------| + * off end_off + */ if (i < sub_stripes) bbio->stripes[i].length -= stripe_offset; - if ((i / sub_stripes + 1) % - sub_stripes == remaining_stripes) + + if (stripe_index >= last_stripe && + stripe_index <= (last_stripe + + sub_stripes - 1)) bbio->stripes[i].length -= stripe_end_offset; + if (i == sub_stripes - 1) stripe_offset = 0; } else |