From ecda7c0280e6b3398459dc589b9a41c1adb45529 Mon Sep 17 00:00:00 2001 From: Nikos Tsironis Date: Wed, 4 Dec 2019 16:07:41 +0200 Subject: dm thin metadata: Add support for a pre-commit callback 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: stable@vger.kernel.org Signed-off-by: Nikos Tsironis Acked-by: Joe Thornber Signed-off-by: Mike Snitzer --- 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 @@ -188,6 +188,15 @@ struct dm_pool_metadata { unsigned long flags; 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 -- cgit v1.2.3