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author | Liu Bo <bo.li.liu@oracle.com> | 2016-07-14 18:40:27 -0700 |
---|---|---|
committer | David Sterba <dsterba@suse.com> | 2016-07-15 11:45:29 +0200 |
commit | addd7e7f208d5dfcf369c60ff1cb4d2bf8b5ab30 (patch) | |
tree | 514e820854132c4bfe430c6cf5e5ca2a96bc6996 /btrfs-map-logical.c | |
parent | ebbddd7fd4307a692355490494ebc53ef0689f39 (diff) |
Btrfs-progs: fix btrfs-map-logical to only print extent mapping info
I have a valid btrfs image which contains,
...
item 10 key (1103101952 BLOCK_GROUP_ITEM 1288372224) itemoff 15947 itemsize 24
block group used 655360 chunk_objectid 256 flags DATA|RAID5
item 11 key (1103364096 EXTENT_ITEM 131072) itemoff 15894 itemsize 53
extent refs 1 gen 11 flags DATA
extent data backref root 5 objectid 258 offset 0 count 1
item 12 key (1103888384 EXTENT_ITEM 262144) itemoff 15841 itemsize 53
extent refs 1 gen 15 flags DATA
extent data backref root 1 objectid 256 offset 0 count 1
item 13 key (1104281600 EXTENT_ITEM 262144) itemoff 15788 itemsize 53
extent refs 1 gen 15 flags DATA
extent data backref root 1 objectid 257 offset 0 count 1
...
The extent [1103364096, 131072) has length 131072, but if we run
"btrfs-map-logical -l 1103364096 -b $((65536 * 3)) /dev/sda"
it will return mapping info 's of non-existing extents.
It's because it assumes that extents's are contiguous on logical address,
when it's not true, after one loop (cur_logical += cur_len) and mapping
the next extent, we can get an extent that is out of our search range and
we end up with a negative @real_len and printing all mapping infos till
the disk end.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'btrfs-map-logical.c')
-rw-r--r-- | btrfs-map-logical.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/btrfs-map-logical.c b/btrfs-map-logical.c index fd0286d5..f421a50f 100644 --- a/btrfs-map-logical.c +++ b/btrfs-map-logical.c @@ -329,6 +329,11 @@ int main(int argc, char **argv) goto out_close_fd; if (ret > 0) break; + /* check again if there is overlap. */ + if (cur_logical + cur_len < logical || + cur_logical >= logical + bytes) + break; + real_logical = max(logical, cur_logical); real_len = min(logical + bytes, cur_logical + cur_len) - real_logical; |