diff options
author | Martin K. Petersen <martin.petersen@oracle.com> | 2015-11-13 16:46:48 -0500 |
---|---|---|
committer | Martin K. Petersen <martin.petersen@oracle.com> | 2015-11-25 21:38:58 -0500 |
commit | ca369d51b3e1649be4a72addd6d6a168cfb3f537 (patch) | |
tree | 38f0d07a92f6939da923b0ef8948ea6e8b44b2a6 /block/blk-settings.c | |
parent | f7f9f26b139e53d798ea76465223a5f237d90fd3 (diff) | |
download | linux-ca369d51b3e1649be4a72addd6d6a168cfb3f537.tar.gz linux-ca369d51b3e1649be4a72addd6d6a168cfb3f537.tar.bz2 linux-ca369d51b3e1649be4a72addd6d6a168cfb3f537.zip |
block/sd: Fix device-imposed transfer length limits
Commit 4f258a46346c ("sd: Fix maximum I/O size for BLOCK_PC requests")
had the unfortunate side-effect of removing an implicit clamp to
BLK_DEF_MAX_SECTORS for REQ_TYPE_FS requests in the block layer
code. This caused problems for some SMR drives.
Debugging this issue revealed a few problems with the existing
infrastructure since the block layer didn't know how to deal with
device-imposed limits, only limits set by the I/O controller.
- Introduce a new queue limit, max_dev_sectors, which is used by the
ULD to signal the maximum sectors for a REQ_TYPE_FS request.
- Ensure that max_dev_sectors is correctly stacked and taken into
account when overriding max_sectors through sysfs.
- Rework sd_read_block_limits() so it saves the max_xfer and opt_xfer
values for later processing.
- In sd_revalidate() set the queue's max_dev_sectors based on the
MAXIMUM TRANSFER LENGTH value in the Block Limits VPD. If this value
is not reported, fall back to a cap based on the CDB TRANSFER LENGTH
field size.
- In sd_revalidate(), use OPTIMAL TRANSFER LENGTH from the Block Limits
VPD--if reported and sane--to signal the preferred device transfer
size for FS requests. Otherwise use BLK_DEF_MAX_SECTORS.
- blk_limits_max_hw_sectors() is no longer used and can be removed.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=93581
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: sweeneygj@gmx.com
Tested-by: Arzeets <anatol.pomozov@gmail.com>
Tested-by: David Eisner <david.eisner@oriel.oxon.org>
Tested-by: Mario Kicherer <dev@kicherer.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'block/blk-settings.c')
-rw-r--r-- | block/blk-settings.c | 36 |
1 files changed, 16 insertions, 20 deletions
diff --git a/block/blk-settings.c b/block/blk-settings.c index 7d8f129a1516..dd4973583978 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -91,7 +91,8 @@ void blk_set_default_limits(struct queue_limits *lim) lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK; lim->virt_boundary_mask = 0; lim->max_segment_size = BLK_MAX_SEGMENT_SIZE; - lim->max_sectors = lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS; + lim->max_sectors = lim->max_dev_sectors = lim->max_hw_sectors = + BLK_SAFE_MAX_SECTORS; lim->chunk_sectors = 0; lim->max_write_same_sectors = 0; lim->max_discard_sectors = 0; @@ -127,6 +128,7 @@ void blk_set_stacking_limits(struct queue_limits *lim) lim->max_hw_sectors = UINT_MAX; lim->max_segment_size = UINT_MAX; lim->max_sectors = UINT_MAX; + lim->max_dev_sectors = UINT_MAX; lim->max_write_same_sectors = UINT_MAX; } EXPORT_SYMBOL(blk_set_stacking_limits); @@ -214,8 +216,8 @@ void blk_queue_bounce_limit(struct request_queue *q, u64 max_addr) EXPORT_SYMBOL(blk_queue_bounce_limit); /** - * blk_limits_max_hw_sectors - set hard and soft limit of max sectors for request - * @limits: the queue limits + * blk_queue_max_hw_sectors - set max sectors for a request for this queue + * @q: the request queue for the device * @max_hw_sectors: max hardware sectors in the usual 512b unit * * Description: @@ -224,13 +226,19 @@ EXPORT_SYMBOL(blk_queue_bounce_limit); * the device driver based upon the capabilities of the I/O * controller. * + * max_dev_sectors is a hard limit imposed by the storage device for + * READ/WRITE requests. It is set by the disk driver. + * * max_sectors is a soft limit imposed by the block layer for * filesystem type requests. This value can be overridden on a * per-device basis in /sys/block/<device>/queue/max_sectors_kb. * The soft limit can not exceed max_hw_sectors. **/ -void blk_limits_max_hw_sectors(struct queue_limits *limits, unsigned int max_hw_sectors) +void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_sectors) { + struct queue_limits *limits = &q->limits; + unsigned int max_sectors; + if ((max_hw_sectors << 9) < PAGE_CACHE_SIZE) { max_hw_sectors = 1 << (PAGE_CACHE_SHIFT - 9); printk(KERN_INFO "%s: set to minimum %d\n", @@ -238,22 +246,9 @@ void blk_limits_max_hw_sectors(struct queue_limits *limits, unsigned int max_hw_ } limits->max_hw_sectors = max_hw_sectors; - limits->max_sectors = min_t(unsigned int, max_hw_sectors, - BLK_DEF_MAX_SECTORS); -} -EXPORT_SYMBOL(blk_limits_max_hw_sectors); - -/** - * blk_queue_max_hw_sectors - set max sectors for a request for this queue - * @q: the request queue for the device - * @max_hw_sectors: max hardware sectors in the usual 512b unit - * - * Description: - * See description for blk_limits_max_hw_sectors(). - **/ -void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_sectors) -{ - blk_limits_max_hw_sectors(&q->limits, max_hw_sectors); + max_sectors = min_not_zero(max_hw_sectors, limits->max_dev_sectors); + max_sectors = min_t(unsigned int, max_sectors, BLK_DEF_MAX_SECTORS); + limits->max_sectors = max_sectors; } EXPORT_SYMBOL(blk_queue_max_hw_sectors); @@ -527,6 +522,7 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors); t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors); + t->max_dev_sectors = min_not_zero(t->max_dev_sectors, b->max_dev_sectors); t->max_write_same_sectors = min(t->max_write_same_sectors, b->max_write_same_sectors); t->bounce_pfn = min_not_zero(t->bounce_pfn, b->bounce_pfn); |