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| author | Joe Thornber <ejt@redhat.com> | 2015-12-02 13:24:39 +0100 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2015-12-02 19:26:49 +0100 |
| commit | 993ceab91986e2e737ce9a3e23bebc8cce649240 (patch) | |
| tree | 271d69ac484060b565f25614cf25a5595b036a6c /drivers/md/dm-thin-metadata.c | |
| parent | dm btree: fix leak of bufio-backed block in btree_split_sibling error path (diff) | |
| download | linux-993ceab91986e2e737ce9a3e23bebc8cce649240.tar.xz linux-993ceab91986e2e737ce9a3e23bebc8cce649240.zip | |
dm thin metadata: fix bug in dm_thin_remove_range()
dm_btree_remove_leaves() only unmaps a contiguous region so we need a
loop, in __remove_range(), to handle ranges that contain multiple
regions.
A new btree function, dm_btree_lookup_next(), is introduced which is
more efficiently able to skip over regions of the thin device which
aren't mapped. __remove_range() uses dm_btree_lookup_next() for each
iteration of __remove_range()'s loop.
Also, improve description of dm_btree_remove_leaves().
Fixes: 6550f075 ("dm thin metadata: add dm_thin_remove_range()")
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 4.1+
Diffstat (limited to '')
| -rw-r--r-- | drivers/md/dm-thin-metadata.c | 28 |
1 files changed, 23 insertions, 5 deletions
diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c index 1fa45695b68a..67871e74c82b 100644 --- a/drivers/md/dm-thin-metadata.c +++ b/drivers/md/dm-thin-metadata.c @@ -1538,7 +1538,7 @@ static int __remove(struct dm_thin_device *td, dm_block_t block) static int __remove_range(struct dm_thin_device *td, dm_block_t begin, dm_block_t end) { int r; - unsigned count; + unsigned count, total_count = 0; struct dm_pool_metadata *pmd = td->pmd; dm_block_t keys[1] = { td->id }; __le64 value; @@ -1561,11 +1561,29 @@ static int __remove_range(struct dm_thin_device *td, dm_block_t begin, dm_block_ if (r) return r; - r = dm_btree_remove_leaves(&pmd->bl_info, mapping_root, &begin, end, &mapping_root, &count); - if (r) - return r; + /* + * Remove leaves stops at the first unmapped entry, so we have to + * loop round finding mapped ranges. + */ + while (begin < end) { + r = dm_btree_lookup_next(&pmd->bl_info, mapping_root, &begin, &begin, &value); + if (r == -ENODATA) + break; + + if (r) + return r; + + if (begin >= end) + break; + + r = dm_btree_remove_leaves(&pmd->bl_info, mapping_root, &begin, end, &mapping_root, &count); + if (r) + return r; + + total_count += count; + } - td->mapped_blocks -= count; + td->mapped_blocks -= total_count; td->changed = 1; /* |