[dm-devel] [PATCH v5 13/13] dm snapshot: report merge failure in status
Mike Snitzer
snitzer at redhat.com
Sat Dec 5 18:44:38 UTC 2009
Set 'merge_failed' flag if a snapshot fails to merge. Update
snapshot_status() to report "Merge failed" if 'merge_failed' is set.
Signed-off-by: Mike Snitzer <snitzer at redhat.com>
---
NOTE: Revised slightly so all other merge failures in merge_callback()
properly set 'merge_failed'
---
drivers/md/dm-snap.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
Index: linux-2.6-dev/drivers/md/dm-snap.c
===================================================================
--- linux-2.6-dev.orig/drivers/md/dm-snap.c
+++ linux-2.6-dev/drivers/md/dm-snap.c
@@ -102,6 +102,9 @@ struct dm_snapshot {
spinlock_t tracked_chunk_lock;
struct hlist_head tracked_chunk_hash[DM_TRACKED_CHUNK_HASH_SIZE];
+ /* Merge operation failed if this is set */
+ int merge_failed;
+
/* Merge operation is in progress */
int merge_running;
@@ -775,9 +778,13 @@ static void snapshot_merge_process(struc
linear_chunks = s->store->type->prepare_merge(s->store,
&old_chunk, &new_chunk);
if (linear_chunks <= 0) {
- if (linear_chunks < 0)
+ if (linear_chunks < 0) {
DMERR("Read error in exception store, "
"shutting down merge");
+ down_write(&s->lock);
+ s->merge_failed = 1;
+ up_write(&s->lock);
+ }
goto shut;
}
/* Adjust old_chunk and new_chunk to reflect start of linear region */
@@ -914,6 +921,7 @@ static void merge_callback(int read_err,
shut:
down_write(&s->lock);
+ s->merge_failed = 1;
release_write_interlock(s, 1);
s->merge_running = 0;
}
@@ -1002,6 +1010,7 @@ static int snapshot_ctr(struct dm_target
init_rwsem(&s->lock);
INIT_LIST_HEAD(&s->list);
spin_lock_init(&s->pe_lock);
+ s->merge_failed = 0;
s->merge_running = 0;
s->merge_shutdown = 0;
s->merge_write_interlock = 0;
@@ -1741,6 +1750,8 @@ static int snapshot_status(struct dm_tar
if (!snap->valid)
DMEMIT("Invalid");
+ else if (snap->merge_failed)
+ DMEMIT("Merge failed");
else {
if (snap->store->type->usage) {
sector_t total_sectors, sectors_allocated,
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