Merge tag 'for-5.2/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/…

…kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - Fix incorrect uses of kstrndup and DM logging macros in DM's early
   init code.

 - Fix DM log-writes target's handling of super block sectors so updates
   are made in order through use of completion.

 - Fix DM core's argument splitting code to avoid undefined behaviour
   reported as a side-effect of UBSAN analysis on ppc64le.

 - Fix DM verity target to limit the amount of error messages that can
   result from a corrupt block being found.

* tag 'for-5.2/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm verity: use message limit for data block corruption message
  dm table: don't copy from a NULL pointer in realloc_argv()
  dm log writes: make sure super sector log updates are written in order
  dm init: remove trailing newline from calls to DMERR() and DMINFO()
  dm init: fix incorrect uses of kstrndup()

drivers/md/dm-init.c

@@ -140,8 +140,8 @@ static char __init *dm_parse_table_entry(struct dm_device *dev, char *str)
 		return ERR_PTR(-EINVAL);
 	}
 	/* target_args */
-	dev->target_args_array[n] = kstrndup(field[3], GFP_KERNEL,
-					     DM_MAX_STR_SIZE);
+	dev->target_args_array[n] = kstrndup(field[3], DM_MAX_STR_SIZE,
+					     GFP_KERNEL);
 	if (!dev->target_args_array[n])
 		return ERR_PTR(-ENOMEM);
 
@@ -272,18 +272,18 @@ static int __init dm_init_init(void)
 		return 0;
 
 	if (strlen(create) >= DM_MAX_STR_SIZE) {
-		DMERR("Argument is too big. Limit is %d\n", DM_MAX_STR_SIZE);
+		DMERR("Argument is too big. Limit is %d", DM_MAX_STR_SIZE);
 		return -EINVAL;
 	}
-	str = kstrndup(create, GFP_KERNEL, DM_MAX_STR_SIZE);
+	str = kstrndup(create, DM_MAX_STR_SIZE, GFP_KERNEL);
 	if (!str)
 		return -ENOMEM;
 
 	r = dm_parse_devices(&devices, str);
 	if (r)
 		goto out;
 
-	DMINFO("waiting for all devices to be available before creating mapped devices\n");
+	DMINFO("waiting for all devices to be available before creating mapped devices");
 	wait_for_device_probe();
 
 	list_for_each_entry(dev, &devices, list) {

drivers/md/dm-log-writes.c

@@ -60,6 +60,7 @@
 
 #define WRITE_LOG_VERSION 1ULL
 #define WRITE_LOG_MAGIC 0x6a736677736872ULL
+#define WRITE_LOG_SUPER_SECTOR 0
 
 /*
  * The disk format for this is braindead simple.
@@ -115,6 +116,7 @@ struct log_writes_c {
 	struct list_head logging_blocks;
 	wait_queue_head_t wait;
 	struct task_struct *log_kthread;
+	struct completion super_done;
 };
 
 struct pending_block {
@@ -180,6 +182,14 @@ static void log_end_io(struct bio *bio)
 	bio_put(bio);
 }
 
+static void log_end_super(struct bio *bio)
+{
+	struct log_writes_c *lc = bio->bi_private;
+
+	complete(&lc->super_done);
+	log_end_io(bio);
+}
+
 /*
  * Meant to be called if there is an error, it will free all the pages
  * associated with the block.
@@ -215,7 +225,8 @@ static int write_metadata(struct log_writes_c *lc, void *entry,
 	bio->bi_iter.bi_size = 0;
 	bio->bi_iter.bi_sector = sector;
 	bio_set_dev(bio, lc->logdev->bdev);
-	bio->bi_end_io = log_end_io;
+	bio->bi_end_io = (sector == WRITE_LOG_SUPER_SECTOR) ?
+			  log_end_super : log_end_io;
 	bio->bi_private = lc;
 	bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
 
@@ -418,11 +429,18 @@ static int log_super(struct log_writes_c *lc)
 	super.nr_entries = cpu_to_le64(lc->logged_entries);
 	super.sectorsize = cpu_to_le32(lc->sectorsize);
 
-	if (write_metadata(lc, &super, sizeof(super), NULL, 0, 0)) {
+	if (write_metadata(lc, &super, sizeof(super), NULL, 0,
+			   WRITE_LOG_SUPER_SECTOR)) {
 		DMERR("Couldn't write super");
 		return -1;
 	}
 
+	/*
+	 * Super sector should be writen in-order, otherwise the
+	 * nr_entries could be rewritten incorrectly by an old bio.
+	 */
+	wait_for_completion_io(&lc->super_done);
+
 	return 0;
 }
 
@@ -531,6 +549,7 @@ static int log_writes_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	INIT_LIST_HEAD(&lc->unflushed_blocks);
 	INIT_LIST_HEAD(&lc->logging_blocks);
 	init_waitqueue_head(&lc->wait);
+	init_completion(&lc->super_done);
 	atomic_set(&lc->io_blocks, 0);
 	atomic_set(&lc->pending_blocks, 0);
 

drivers/md/dm-table.c

@@ -561,7 +561,7 @@ static char **realloc_argv(unsigned *size, char **old_argv)
 		gfp = GFP_NOIO;
 	}
 	argv = kmalloc_array(new_size, sizeof(*argv), gfp);
-	if (argv) {
+	if (argv && old_argv) {
 		memcpy(argv, old_argv, *size * sizeof(*argv));
 		*size = new_size;
 	}

drivers/md/dm-verity-target.c

@@ -235,8 +235,8 @@ static int verity_handle_err(struct dm_verity *v, enum verity_block_type type,
 		BUG();
 	}
 
-	DMERR("%s: %s block %llu is corrupted", v->data_dev->name, type_str,
-		block);
+	DMERR_LIMIT("%s: %s block %llu is corrupted", v->data_dev->name,
+		    type_str, block);
 
 	if (v->corrupted_errs == DM_VERITY_MAX_CORRUPTED_ERRS)
 		DMERR("%s: reached maximum errors", v->data_dev->name);