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| author |   Martin K. Petersen <martin.petersen@oracle.com> | 2017-04-05 19:21:24 +0200 |
|---|---|---|
| committer |   Jens Axboe <axboe@fb.com> | 2017-04-08 11:25:38 -0600 |
| commit | e6bd931284b4b9bc17a2995257a0769370bc5202 (patch) | |
| tree | e12c369f377128d409423f3dcc926445950bb1f8 /drivers/scsi/sd.h | |
| parent | block: remove the discard_zeroes_data flag (diff) | |
| download | linux-dev-e6bd931284b4b9bc17a2995257a0769370bc5202.tar.xz linux-dev-e6bd931284b4b9bc17a2995257a0769370bc5202.zip | |
scsi: sd: Separate zeroout and discard command choices
Now that zeroout and discards are distinct operations we need to
separate the policy of choosing the appropriate command. Create a
zeroing_mode which can be one of:
write: Zeroout assist not present, use regular WRITE
writesame: Allow WRITE SAME(10/16) with a zeroed payload
writesame_16_unmap: Allow WRITE SAME(16) with UNMAP
writesame_10_unmap: Allow WRITE SAME(10) with UNMAP
The last two are conditional on the device being thin provisioned with
LBPRZ=1 and LBPWS=1 or LBPWS10=1 respectively.
Whether to set the UNMAP bit or not depends on the REQ_NOUNMAP flag. And
if none of the _unmap variants are supported, regular WRITE SAME will be
used if the device supports it.
The zeroout_mode is exported in sysfs and the detected mode for a given
device can be overridden using the string constants above.
With this change in place we can now issue WRITE SAME(16) with UNMAP set
for block zeroing applications that require hard guarantees and
logical_block_size granularity. And at the same time use the UNMAP
command with the device's preferred granulary and alignment for discard
operations.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'drivers/scsi/sd.h')
| -rw-r--r-- | drivers/scsi/sd.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h index 4dac35e96a75..a2c4b5c35379 100644 --- a/drivers/scsi/sd.h +++ b/drivers/scsi/sd.h @@ -59,6 +59,13 @@ enum { SD_LBP_DISABLE, /* Discard disabled due to failed cmd */ }; +enum { + SD_ZERO_WRITE = 0, /* Use WRITE(10/16) command */ + SD_ZERO_WS, /* Use WRITE SAME(10/16) command */ + SD_ZERO_WS16_UNMAP, /* Use WRITE SAME(16) with UNMAP */ + SD_ZERO_WS10_UNMAP, /* Use WRITE SAME(10) with UNMAP */ +}; + struct scsi_disk { struct scsi_driver *driver; /* always &sd_template */ struct scsi_device *device; @@ -89,6 +96,7 @@ struct scsi_disk { u8 write_prot; u8 protection_type;/* Data Integrity Field */ u8 provisioning_mode; + u8 zeroing_mode; unsigned ATO : 1; /* state of disk ATO bit */ unsigned cache_override : 1; /* temp override of WCE,RCD */ unsigned WCE : 1; /* state of disk WCE bit */ |