path: root/block/blk-sysfs.c
diff options
authorMartin K. Petersen <martin.petersen@oracle.com>2011-05-18 10:37:35 +0200
committerJens Axboe <jaxboe@fusionio.com>2011-05-18 10:37:35 +0200
commita934a00a69e940b126b9bdbf83e630ef5fe43523 (patch)
treeb3f82d7b0a6c34c4d449debd2d1d242bdbf84b56 /block/blk-sysfs.c
parentbbdd304cf66fbf2b4b2d28418dc619d443635e83 (diff)
block: Fix discard topology stacking and reporting
In some cases we would end up stacking discard_zeroes_data incorrectly. Fix this by enabling the feature by default for stacking drivers and clearing it for low-level drivers. Incorporating a device that does not support dzd will then cause the feature to be disabled in the stacking driver. Also ensure that the maximum discard value does not overflow when exported in sysfs and return 0 in the alignment and dzd fields for devices that don't support discard. Reported-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@kernel.org Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Diffstat (limited to 'block/blk-sysfs.c')
1 files changed, 2 insertions, 1 deletions
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 6d735122bc59..53bd0c77bfda 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -152,7 +152,8 @@ static ssize_t queue_discard_granularity_show(struct request_queue *q, char *pag
static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
- return queue_var_show(q->limits.max_discard_sectors << 9, page);
+ return sprintf(page, "%llu\n",
+ (unsigned long long)q->limits.max_discard_sectors << 9);
static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)