This is a note to let you know that I've just added the patch titled dm thin metadata: Add support for a pre-commit callback to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: dm-thin-metadata-add-support-for-a-pre-commit-callback.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From ecda7c0280e6b3398459dc589b9a41c1adb45529 Mon Sep 17 00:00:00 2001 From: Nikos Tsironis <ntsironis@xxxxxxxxxxx> Date: Wed, 4 Dec 2019 16:07:41 +0200 Subject: dm thin metadata: Add support for a pre-commit callback From: Nikos Tsironis <ntsironis@xxxxxxxxxxx> commit ecda7c0280e6b3398459dc589b9a41c1adb45529 upstream. 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@xxxxxxxxxxxxxxx Signed-off-by: Nikos Tsironis <ntsironis@xxxxxxxxxxx> Acked-by: Joe Thornber <ejt@xxxxxxxxxx> Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/md/dm-thin-metadata.c | 29 +++++++++++++++++++++++++++++ drivers/md/dm-thin-metadata.h | 7 +++++++ 2 files changed, 36 insertions(+) --- 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. */ @@ -791,6 +800,14 @@ static int __commit_transaction(struct d */ BUILD_BUG_ON(sizeof(struct thin_disk_superblock) > 512); + 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; @@ -864,6 +881,8 @@ struct dm_pool_metadata *dm_pool_metadat pmd->fail_io = 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) { @@ -2008,6 +2027,16 @@ int dm_pool_register_metadata_threshold( 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; --- 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 */ 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 Patches currently in stable-queue which might be from ntsironis@xxxxxxxxxxx are queue-4.14/dm-thin-flush-data-device-before-committing-metadata.patch queue-4.14/dm-thin-metadata-add-support-for-a-pre-commit-callback.patch