Merge tag 'for-6.18/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mikulas Patocka:

 - dm-pcache fixes

 - fix a regression with empty flush bios

 - dm-verity: fix unreliable memory allocation with GFP_NOWAIT

* tag 'for-6.18/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm-verity: fix unreliable memory allocation
  dm: fix failure when empty flush's bi_sector points beyond the device end
  dm-pcache: zero cache_info before default init
  dm-pcache: reuse meta_addr in pcache_meta_find_latest
  dm-pcache: allow built-in build and rename flush helper

Author: torvalds

drivers/md/dm-pcache/Makefile

@@ -1,3 +1,3 @@
 dm-pcache-y := dm_pcache.o cache_dev.o segment.o backing_dev.o cache.o cache_gc.o cache_writeback.o cache_segment.o cache_key.o cache_req.o
 
-obj-m += dm-pcache.o
+obj-$(CONFIG_DM_PCACHE) += dm-pcache.o

drivers/md/dm-pcache/cache.c

@@ -181,7 +181,7 @@ static void cache_info_init_default(struct pcache_cache *cache)
 {
 	struct pcache_cache_info *cache_info = &cache->cache_info;
 
-	cache_info->header.seq = 0;
+	memset(cache_info, 0, sizeof(*cache_info));
 	cache_info->n_segs = cache->cache_dev->seg_num;
 	cache_info_set_gc_percent(cache_info, PCACHE_CACHE_GC_PERCENT_DEFAULT);
 }
@@ -411,7 +411,7 @@ void pcache_cache_stop(struct dm_pcache *pcache)
 {
 	struct pcache_cache *cache = &pcache->cache;
 
-	cache_flush(cache);
+	pcache_cache_flush(cache);
 
 	cancel_delayed_work_sync(&cache->gc_work);
 	flush_work(&cache->clean_work);

drivers/md/dm-pcache/cache.h

@@ -339,7 +339,7 @@ void cache_seg_put(struct pcache_cache_segment *cache_seg);
 void cache_seg_set_next_seg(struct pcache_cache_segment *cache_seg, u32 seg_id);
 
 /* cache request*/
-int cache_flush(struct pcache_cache *cache);
+int pcache_cache_flush(struct pcache_cache *cache);
 void miss_read_end_work_fn(struct work_struct *work);
 int pcache_cache_handle_req(struct pcache_cache *cache, struct pcache_request *pcache_req);
 

drivers/md/dm-pcache/cache_req.c

@@ -790,7 +790,7 @@ static int cache_write(struct pcache_cache *cache, struct pcache_request *pcache
 }
 
 /**
- * cache_flush - Flush all ksets to persist any pending cache data
+ * pcache_cache_flush - Flush all ksets to persist any pending cache data
  * @cache: Pointer to the cache structure
  *
  * This function iterates through all ksets associated with the provided `cache`
@@ -802,7 +802,7 @@ static int cache_write(struct pcache_cache *cache, struct pcache_request *pcache
  * the respective error code, preventing the flush operation from proceeding to
  * subsequent ksets.
  */
-int cache_flush(struct pcache_cache *cache)
+int pcache_cache_flush(struct pcache_cache *cache)
 {
 	struct pcache_cache_kset *kset;
 	int ret;
@@ -827,7 +827,7 @@ int pcache_cache_handle_req(struct pcache_cache *cache, struct pcache_request *p
 	struct bio *bio = pcache_req->bio;
 
 	if (unlikely(bio->bi_opf & REQ_PREFLUSH))
-		return cache_flush(cache);
+		return pcache_cache_flush(cache);
 
 	if (bio_data_dir(bio) == READ)
 		return cache_read(cache, pcache_req);

drivers/md/dm-pcache/pcache_internal.h

@@ -99,7 +99,7 @@ static inline void __must_check *pcache_meta_find_latest(struct pcache_meta_head
 		/* Update latest if a more recent sequence is found */
 		if (!latest || pcache_meta_seq_after(meta->seq, seq_latest)) {
 			seq_latest = meta->seq;
-			latest = (void *)header + (i * meta_max_size);
+			latest = meta_addr;
 		}
 	}
 

drivers/md/dm-verity-fec.c

@@ -320,11 +320,7 @@ static int fec_alloc_bufs(struct dm_verity *v, struct dm_verity_fec_io *fio)
 		if (fio->bufs[n])
 			continue;
 
-		fio->bufs[n] = mempool_alloc(&v->fec->prealloc_pool, GFP_NOWAIT);
-		if (unlikely(!fio->bufs[n])) {
-			DMERR("failed to allocate FEC buffer");
-			return -ENOMEM;
-		}
+		fio->bufs[n] = mempool_alloc(&v->fec->prealloc_pool, GFP_NOIO);
 	}
 
 	/* try to allocate the maximum number of buffers */

drivers/md/dm.c

@@ -2005,7 +2005,7 @@ static void dm_split_and_process_bio(struct mapped_device *md,
 		 * linear target or multiple linear targets pointing to the same
 		 * device), we can send the flush with data directly to it.
 		 */
-		if (map->flush_bypasses_map) {
+		if (bio->bi_iter.bi_size && map->flush_bypasses_map) {
 			struct list_head *devices = dm_table_get_devices(map);
 			if (devices->next == devices->prev)
 				goto send_preflush_with_data;