On 12/5/19 9:40 PM, Mike Snitzer wrote:
On Wed, Dec 04 2019 at 9:07P -0500,
Nikos Tsironis <[email protected]> wrote:
Add support for one pre-commit callback which is run right before the
metadata are committed.
This allows the thin provisioning target to run a callback before the
metadata are committed and is required by the next commit.
Cc: [email protected]
Signed-off-by: Nikos Tsironis <[email protected]>
---
drivers/md/dm-thin-metadata.c | 29 +++++++++++++++++++++++++++++
drivers/md/dm-thin-metadata.h | 7 +++++++
2 files changed, 36 insertions(+)
diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c
index 4c68a7b93d5e..b88d6d701f5b 100644
--- a/drivers/md/dm-thin-metadata.c
+++ b/drivers/md/dm-thin-metadata.c
@@ -189,6 +189,15 @@ struct dm_pool_metadata {
sector_t data_block_size;
/*
+ * Pre-commit callback.
+ *
+ * This allows the thin provisioning target to run a callback before
+ * the metadata are committed.
+ */
+ dm_pool_pre_commit_fn pre_commit_fn;
+ void *pre_commit_context;
+
+ /*
* We reserve a section of the metadata for commit overhead.
* All reported space does *not* include this.
*/
@@ -826,6 +835,14 @@ static int __commit_transaction(struct dm_pool_metadata
*pmd)
if (unlikely(!pmd->in_service))
return 0;
+ if (pmd->pre_commit_fn) {
+ r = pmd->pre_commit_fn(pmd->pre_commit_context);
+ if (r < 0) {
+ DMERR("pre-commit callback failed");
+ return r;
+ }
+ }
+
r = __write_changed_details(pmd);
if (r < 0)
return r;
@@ -892,6 +909,8 @@ struct dm_pool_metadata *dm_pool_metadata_open(struct
block_device *bdev,
pmd->in_service = false;
pmd->bdev = bdev;
pmd->data_block_size = data_block_size;
+ pmd->pre_commit_fn = NULL;
+ pmd->pre_commit_context = NULL;
r = __create_persistent_data_objects(pmd, format_device);
if (r) {
@@ -2044,6 +2063,16 @@ int dm_pool_register_metadata_threshold(struct
dm_pool_metadata *pmd,
return r;
}
+void dm_pool_register_pre_commit_callback(struct dm_pool_metadata *pmd,
+ dm_pool_pre_commit_fn fn,
+ void *context)
+{
+ pmd_write_lock_in_core(pmd);
+ pmd->pre_commit_fn = fn;
+ pmd->pre_commit_context = context;
+ pmd_write_unlock(pmd);
+}
+
int dm_pool_metadata_set_needs_check(struct dm_pool_metadata *pmd)
{
int r = -EINVAL;
diff --git a/drivers/md/dm-thin-metadata.h b/drivers/md/dm-thin-metadata.h
index f6be0d733c20..7ef56bd2a7e3 100644
--- a/drivers/md/dm-thin-metadata.h
+++ b/drivers/md/dm-thin-metadata.h
@@ -230,6 +230,13 @@ bool dm_pool_metadata_needs_check(struct dm_pool_metadata
*pmd);
*/
void dm_pool_issue_prefetches(struct dm_pool_metadata *pmd);
+/* Pre-commit callback */
+typedef int (*dm_pool_pre_commit_fn)(void *context);
+
+void dm_pool_register_pre_commit_callback(struct dm_pool_metadata *pmd,
+ dm_pool_pre_commit_fn fn,
+ void *context);
+
/*----------------------------------------------------------------*/
#endif
--
2.11.0
I have this incremental, not seeing need to avoid using blkdev_issue_flush
Ack,
Nikos.
---
drivers/md/dm-thin.c | 12 +-----------
1 file changed, 1 insertion(+), 11 deletions(-)
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index 9c9a323c0c30..255a52f7bbf0 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -3203,18 +3203,8 @@ static void metadata_low_callback(void *context)
static int metadata_pre_commit_callback(void *context)
{
struct pool_c *pt = context;
- struct bio bio;
- int r;
-
- bio_init(&bio, NULL, 0);
- bio_set_dev(&bio, pt->data_dev->bdev);
- bio.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
-
- r = submit_bio_wait(&bio);
- bio_uninit(&bio);
-
- return r;
+ return blkdev_issue_flush(pt->data_dev->bdev, GFP_NOIO, NULL);
}
static sector_t get_dev_size(struct block_device *bdev)
--
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