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| author | Martin K. Petersen <martin.petersen@oracle.com> | 2015-11-13 22:46:48 +0100 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2015-11-26 03:38:58 +0100 |
| commit | ca369d51b3e1649be4a72addd6d6a168cfb3f537 (patch) | |
| tree | 38f0d07a92f6939da923b0ef8948ea6e8b44b2a6 /block/blk-sysfs.c | |
| parent | scsi_debug: fix prevent_allow+verify regressions (diff) | |
| download | linux-ca369d51b3e1649be4a72addd6d6a168cfb3f537.tar.xz 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-sysfs.c')
| -rw-r--r-- | block/blk-sysfs.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 3e44a9da2a13..55c637b9c42b 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -205,6 +205,9 @@ queue_max_sectors_store(struct request_queue *q, const char *page, size_t count) if (ret < 0) return ret; + max_hw_sectors_kb = min_not_zero(max_hw_sectors_kb, (unsigned long) + q->limits.max_dev_sectors >> 1); + if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb) return -EINVAL; |