diff options
authorDamien Le Moal <>2019-04-18 18:03:07 +0900
committerGreg Kroah-Hartman <>2019-05-25 18:22:19 +0200
commitfab2e96c6be0078059ce77f2ee0fb2b8d7c22124 (patch)
parentef3f84246954dbfb603fb100f6f5391f938a9134 (diff)
dm zoned: Fix zone report handling
commit 7aedf75ff740a98f3683439449cd91c8662d03b2 upstream. The function blkdev_report_zones() returns success even if no zone information is reported (empty report). Empty zone reports can only happen if the report start sector passed exceeds the device capacity. The conditions for this to happen are either a bug in the caller code, or, a change in the device that forced the low level driver to change the device capacity to a value that is lower than the report start sector. This situation includes a failed disk revalidation resulting in the disk capacity being changed to 0. If this change happens while dm-zoned is in its initialization phase executing dmz_init_zones(), this function may enter an infinite loop and hang the system. To avoid this, add a check to disallow empty zone reports and bail out early. Also fix the function dmz_update_zone() to make sure that the report for the requested zone was correctly obtained. Fixes: 3b1a94c88b79 ("dm zoned: drive-managed zoned block device target") Cc: Signed-off-by: Damien Le Moal <> Reviewed-by: Shaun Tancheff <> Signed-off-by: Damien Le Moal <> Signed-off-by: Mike Snitzer <> Signed-off-by: Greg Kroah-Hartman <>
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/md/dm-zoned-metadata.c b/drivers/md/dm-zoned-metadata.c
index fa68336560c3..d8334cd45d7c 100644
--- a/drivers/md/dm-zoned-metadata.c
+++ b/drivers/md/dm-zoned-metadata.c
@@ -1169,6 +1169,9 @@ static int dmz_init_zones(struct dmz_metadata *zmd)
goto out;
+ if (!nr_blkz)
+ break;
/* Process report */
for (i = 0; i < nr_blkz; i++) {
ret = dmz_init_zone(zmd, zone, &blkz[i]);
@@ -1204,6 +1207,8 @@ static int dmz_update_zone(struct dmz_metadata *zmd, struct dm_zone *zone)
/* Get zone information from disk */
ret = blkdev_report_zones(zmd->dev->bdev, dmz_start_sect(zmd, zone),
&blkz, &nr_blkz, GFP_NOIO);
+ if (!nr_blkz)
+ ret = -EIO;
if (ret) {
dmz_dev_err(zmd->dev, "Get zone %u report failed",
dmz_id(zmd, zone));