Merge tag 'for-6.9/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - Fix a memory leak in DM integrity recheck code that was added during
   the 6.9 merge. Also fix the recheck code to ensure it issues bios
   with proper alignment.

 - Fix DM snapshot's dm_exception_table_exit() to schedule while
   handling an large exception table during snapshot device shutdown.

* tag 'for-6.9/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm-integrity: align the outgoing bio in integrity_recheck
  dm snapshot: fix lockup in dm_exception_table_exit
  dm-integrity: fix a memory leak when rechecking the data

2 files changed, 16 insertions, 6 deletions

diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
index d822ab2f739b..37b9f8f1ae1a 100644
--- a/drivers/md/dm-integrity.c
+++ b/drivers/md/dm-integrity.c
@@ -1699,7 +1699,6 @@ static noinline void integrity_recheck(struct dm_integrity_io *dio, char *checks
 	struct bio_vec bv;
 	sector_t sector, logical_sector, area, offset;
 	struct page *page;
-	void *buffer;
 
 	get_area_and_offset(ic, dio->range.logical_sector, &area, &offset);
 	dio->metadata_block = get_metadata_sector_and_offset(ic, area, offset,
@@ -1708,13 +1707,14 @@ static noinline void integrity_recheck(struct dm_integrity_io *dio, char *checks
 	logical_sector = dio->range.logical_sector;
 
 	page = mempool_alloc(&ic->recheck_pool, GFP_NOIO);
-	buffer = page_to_virt(page);
 
 	__bio_for_each_segment(bv, bio, iter, dio->bio_details.bi_iter) {
 		unsigned pos = 0;
 
 		do {
+			sector_t alignment;
 			char *mem;
+			char *buffer = page_to_virt(page);
 			int r;
 			struct dm_io_request io_req;
 			struct dm_io_region io_loc;
@@ -1727,6 +1727,14 @@ static noinline void integrity_recheck(struct dm_integrity_io *dio, char *checks
 			io_loc.sector = sector;
 			io_loc.count = ic->sectors_per_block;
 
+			/* Align the bio to logical block size */
+			alignment = dio->range.logical_sector | bio_sectors(bio) | (PAGE_SIZE >> SECTOR_SHIFT);
+			alignment &= -alignment;
+			io_loc.sector = round_down(io_loc.sector, alignment);
+			io_loc.count += sector - io_loc.sector;
+			buffer += (sector - io_loc.sector) << SECTOR_SHIFT;
+			io_loc.count = round_up(io_loc.count, alignment);
+
 			r = dm_io(&io_req, 1, &io_loc, NULL, IOPRIO_DEFAULT);
 			if (unlikely(r)) {
 				dio->bi_status = errno_to_blk_status(r);
@@ -1848,12 +1856,12 @@ again:
 			r = dm_integrity_rw_tag(ic, checksums, &dio->metadata_block, &dio->metadata_offset,
 						checksums_ptr - checksums, dio->op == REQ_OP_READ ? TAG_CMP : TAG_WRITE);
 			if (unlikely(r)) {
+				if (likely(checksums != checksums_onstack))
+					kfree(checksums);
 				if (r > 0) {
-					integrity_recheck(dio, checksums);
+					integrity_recheck(dio, checksums_onstack);
 					goto skip_io;
 				}
-				if (likely(checksums != checksums_onstack))
-					kfree(checksums);
 				goto error;
 			}
 
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index bf7a574499a3..0ace06d1bee3 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -684,8 +684,10 @@ static void dm_exception_table_exit(struct dm_exception_table *et,
 	for (i = 0; i < size; i++) {
 		slot = et->table + i;
 
-		hlist_bl_for_each_entry_safe(ex, pos, n, slot, hash_list)
+		hlist_bl_for_each_entry_safe(ex, pos, n, slot, hash_list) {
 			kmem_cache_free(mem, ex);
+			cond_resched();
+		}
 	}
 
 	kvfree(et->table);