4.19-stable review patch. If anyone has any objections, please let me know.
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From: Damien Le Moal damien.lemoal@wdc.com
commit 33c2865f8d011a2ca9f67124ddab9dc89382e9f1 upstream.
Since the ref field of struct dmz_mblock is always used with the spinlock of struct dmz_metadata locked, there is no need to use an atomic_t type. Change the type of the ref field to an unsigne integer.
Fixes: 3b1a94c88b79 ("dm zoned: drive-managed zoned block device target") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal damien.lemoal@wdc.com Signed-off-by: Mike Snitzer snitzer@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/md/dm-zoned-metadata.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-)
--- a/drivers/md/dm-zoned-metadata.c +++ b/drivers/md/dm-zoned-metadata.c @@ -99,7 +99,7 @@ struct dmz_mblock { struct rb_node node; struct list_head link; sector_t no; - atomic_t ref; + unsigned int ref; unsigned long state; struct page *page; void *data; @@ -296,7 +296,7 @@ static struct dmz_mblock *dmz_alloc_mblo
RB_CLEAR_NODE(&mblk->node); INIT_LIST_HEAD(&mblk->link); - atomic_set(&mblk->ref, 0); + mblk->ref = 0; mblk->state = 0; mblk->no = mblk_no; mblk->data = page_address(mblk->page); @@ -397,7 +397,7 @@ static struct dmz_mblock *dmz_fetch_mblo return NULL;
spin_lock(&zmd->mblk_lock); - atomic_inc(&mblk->ref); + mblk->ref++; set_bit(DMZ_META_READING, &mblk->state); dmz_insert_mblock(zmd, mblk); spin_unlock(&zmd->mblk_lock); @@ -484,7 +484,8 @@ static void dmz_release_mblock(struct dm
spin_lock(&zmd->mblk_lock);
- if (atomic_dec_and_test(&mblk->ref)) { + mblk->ref--; + if (mblk->ref == 0) { if (test_bit(DMZ_META_ERROR, &mblk->state)) { rb_erase(&mblk->node, &zmd->mblk_rbtree); dmz_free_mblock(zmd, mblk); @@ -511,7 +512,8 @@ static struct dmz_mblock *dmz_get_mblock mblk = dmz_lookup_mblock(zmd, mblk_no); if (mblk) { /* Cache hit: remove block from LRU list */ - if (atomic_inc_return(&mblk->ref) == 1 && + mblk->ref++; + if (mblk->ref == 1 && !test_bit(DMZ_META_DIRTY, &mblk->state)) list_del_init(&mblk->link); } @@ -753,7 +755,7 @@ int dmz_flush_metadata(struct dmz_metada
spin_lock(&zmd->mblk_lock); clear_bit(DMZ_META_DIRTY, &mblk->state); - if (atomic_read(&mblk->ref) == 0) + if (mblk->ref == 0) list_add_tail(&mblk->link, &zmd->mblk_lru_list); spin_unlock(&zmd->mblk_lock); } @@ -2308,7 +2310,7 @@ static void dmz_cleanup_metadata(struct mblk = list_first_entry(&zmd->mblk_dirty_list, struct dmz_mblock, link); dmz_dev_warn(zmd->dev, "mblock %llu still in dirty list (ref %u)", - (u64)mblk->no, atomic_read(&mblk->ref)); + (u64)mblk->no, mblk->ref); list_del_init(&mblk->link); rb_erase(&mblk->node, &zmd->mblk_rbtree); dmz_free_mblock(zmd, mblk); @@ -2326,8 +2328,8 @@ static void dmz_cleanup_metadata(struct root = &zmd->mblk_rbtree; rbtree_postorder_for_each_entry_safe(mblk, next, root, node) { dmz_dev_warn(zmd->dev, "mblock %llu ref %u still in rbtree", - (u64)mblk->no, atomic_read(&mblk->ref)); - atomic_set(&mblk->ref, 0); + (u64)mblk->no, mblk->ref); + mblk->ref = 0; dmz_free_mblock(zmd, mblk); }