[PATCH 3.5 43/88] dm space map common: make sure new space is used during extend

From: Luis Henriques
Date: Fri Feb 07 2014 - 06:42:25 EST


3.5.7.30 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Joe Thornber <ejt@xxxxxxxxxx>

commit 12c91a5c2d2a8e8cc40a9552313e1e7b0a2d9ee3 upstream.

When extending a low level space map we should update nr_blocks at
the start so the new space is used for the index entries.

Otherwise extend can fail, e.g.: sm_metadata_extend call sequence
that fails:
-> sm_ll_extend
-> dm_tm_new_block -> dm_sm_new_block -> sm_bootstrap_new_block
=> returns -ENOSPC because smm->begin == smm->ll.nr_blocks

Signed-off-by: Joe Thornber <ejt@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
drivers/md/persistent-data/dm-space-map-common.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/md/persistent-data/dm-space-map-common.c b/drivers/md/persistent-data/dm-space-map-common.c
index ff3beed..79c02d9 100644
--- a/drivers/md/persistent-data/dm-space-map-common.c
+++ b/drivers/md/persistent-data/dm-space-map-common.c
@@ -244,6 +244,10 @@ int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks)
return -EINVAL;
}

+ /*
+ * We need to set this before the dm_tm_new_block() call below.
+ */
+ ll->nr_blocks = nr_blocks;
for (i = old_blocks; i < blocks; i++) {
struct dm_block *b;
struct disk_index_entry idx;
@@ -251,6 +255,7 @@ int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks)
r = dm_tm_new_block(ll->tm, &dm_sm_bitmap_validator, &b);
if (r < 0)
return r;
+
idx.blocknr = cpu_to_le64(dm_block_location(b));

r = dm_tm_unlock(ll->tm, b);
@@ -265,7 +270,6 @@ int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks)
return r;
}

- ll->nr_blocks = nr_blocks;
return 0;
}

--
1.8.3.2

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