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authorJonathan Brassow <jbrassow@redhat.com>2007-07-12 17:28:25 +0100
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-12 15:01:08 -0700
commit943317efdbc295e8a28df3f5cbd549d066ee8b4a (patch)
tree63eea4f14c4b3913b6755d802afb7631007a9e0e /drivers/md
parent0764147b111b8ca886e4f2e9c9e019106b09b657 (diff)
downloadblackbird-op-linux-943317efdbc295e8a28df3f5cbd549d066ee8b4a.tar.gz
blackbird-op-linux-943317efdbc295e8a28df3f5cbd549d066ee8b4a.zip
dm raid1: clear region outside spinlock
A clear_region function is permitted to block (in practice, rare) but gets called in rh_update_states() with a spinlock held. The bits being marked and cleared by the above functions are used to update the on-disk log, but are never read directly. We can perform these operations outside the spinlock since the bits are only changed within one thread viz. - mark_region in rh_inc() - clear_region in rh_update_states(). So, we grab the clean_regions list items via list_splice() within the spinlock and defer clear_region() until we iterate over the list for deletion - similar to how the recovered_regions list is already handled. We then move the flush() call down to ensure it encapsulates the changes which are done by the later calls to clear_region(). Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/dm-raid1.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index b3bba98af772..04dce7a66494 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -378,10 +378,8 @@ static void rh_update_states(struct region_hash *rh)
list_splice(&rh->clean_regions, &clean);
INIT_LIST_HEAD(&rh->clean_regions);
- list_for_each_entry (reg, &clean, list) {
- rh->log->type->clear_region(rh->log, reg->key);
+ list_for_each_entry(reg, &clean, list)
list_del(&reg->hash_list);
- }
}
if (!list_empty(&rh->recovered_regions)) {
@@ -405,10 +403,12 @@ static void rh_update_states(struct region_hash *rh)
mempool_free(reg, rh->region_pool);
}
- rh->log->type->flush(rh->log);
-
- list_for_each_entry_safe (reg, next, &clean, list)
+ list_for_each_entry_safe(reg, next, &clean, list) {
+ rh->log->type->clear_region(rh->log, reg->key);
mempool_free(reg, rh->region_pool);
+ }
+
+ rh->log->type->flush(rh->log);
}
static void rh_inc(struct region_hash *rh, region_t region)
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