2.6.38-stable review patch. If anyone has any objections, please let us know.
------------------ From: "Martin K. Petersen" <[email protected]> commit a934a00a69e940b126b9bdbf83e630ef5fe43523 upstream. 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 <[email protected]> Signed-off-by: Martin K. Petersen <[email protected]> Acked-by: Mike Snitzer <[email protected]> Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- block/blk-settings.c | 3 ++- block/blk-sysfs.c | 3 ++- include/linux/blkdev.h | 7 +++++-- 3 files changed, 9 insertions(+), 4 deletions(-) --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -120,7 +120,7 @@ void blk_set_default_limits(struct queue lim->discard_granularity = 0; lim->discard_alignment = 0; lim->discard_misaligned = 0; - lim->discard_zeroes_data = -1; + lim->discard_zeroes_data = 1; lim->logical_block_size = lim->physical_block_size = lim->io_min = 512; lim->bounce_pfn = (unsigned long)(BLK_BOUNCE_ANY >> PAGE_SHIFT); lim->alignment_offset = 0; @@ -174,6 +174,7 @@ void blk_queue_make_request(struct reque blk_set_default_limits(&q->limits); blk_queue_max_hw_sectors(q, BLK_SAFE_MAX_SECTORS); + q->limits.discard_zeroes_data = 0; /* * If the caller didn't supply a lock, fall back to our embedded --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -152,7 +152,8 @@ static ssize_t queue_discard_granularity 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) --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -252,7 +252,7 @@ struct queue_limits { unsigned char misaligned; unsigned char discard_misaligned; unsigned char cluster; - signed char discard_zeroes_data; + unsigned char discard_zeroes_data; }; struct request_queue @@ -1032,13 +1032,16 @@ static inline int queue_limit_discard_al { unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1); + if (!lim->max_discard_sectors) + return 0; + return (lim->discard_granularity + lim->discard_alignment - alignment) & (lim->discard_granularity - 1); } static inline unsigned int queue_discard_zeroes_data(struct request_queue *q) { - if (q->limits.discard_zeroes_data == 1) + if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1) return 1; return 0; _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
