linux/drivers/scsi/sd.h
Martin K. Petersen e6bd931284 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>
2017-04-08 11:25:38 -06:00

321 lines
8.2 KiB
C

#ifndef _SCSI_DISK_H
#define _SCSI_DISK_H
/*
* More than enough for everybody ;) The huge number of majors
* is a leftover from 16bit dev_t days, we don't really need that
* much numberspace.
*/
#define SD_MAJORS 16
/*
* Time out in seconds for disks and Magneto-opticals (which are slower).
*/
#define SD_TIMEOUT (30 * HZ)
#define SD_MOD_TIMEOUT (75 * HZ)
/*
* Flush timeout is a multiplier over the standard device timeout which is
* user modifiable via sysfs but initially set to SD_TIMEOUT
*/
#define SD_FLUSH_TIMEOUT_MULTIPLIER 2
#define SD_WRITE_SAME_TIMEOUT (120 * HZ)
/*
* Number of allowed retries
*/
#define SD_MAX_RETRIES 5
#define SD_PASSTHROUGH_RETRIES 1
#define SD_MAX_MEDIUM_TIMEOUTS 2
/*
* Size of the initial data buffer for mode and read capacity data
*/
#define SD_BUF_SIZE 512
/*
* Number of sectors at the end of the device to avoid multi-sector
* accesses to in the case of last_sector_bug
*/
#define SD_LAST_BUGGY_SECTORS 8
enum {
SD_EXT_CDB_SIZE = 32, /* Extended CDB size */
SD_MEMPOOL_SIZE = 2, /* CDB pool size */
};
enum {
SD_DEF_XFER_BLOCKS = 0xffff,
SD_MAX_XFER_BLOCKS = 0xffffffff,
SD_MAX_WS10_BLOCKS = 0xffff,
SD_MAX_WS16_BLOCKS = 0x7fffff,
};
enum {
SD_LBP_FULL = 0, /* Full logical block provisioning */
SD_LBP_UNMAP, /* Use UNMAP command */
SD_LBP_WS16, /* Use WRITE SAME(16) with UNMAP bit */
SD_LBP_WS10, /* Use WRITE SAME(10) with UNMAP bit */
SD_LBP_ZERO, /* Use WRITE SAME(10) with zero payload */
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;
struct device dev;
struct gendisk *disk;
#ifdef CONFIG_BLK_DEV_ZONED
unsigned int nr_zones;
unsigned int zone_blocks;
unsigned int zone_shift;
unsigned long *zones_wlock;
unsigned int zones_optimal_open;
unsigned int zones_optimal_nonseq;
unsigned int zones_max_open;
#endif
atomic_t openers;
sector_t capacity; /* size in logical blocks */
u32 max_xfer_blocks;
u32 opt_xfer_blocks;
u32 max_ws_blocks;
u32 max_unmap_blocks;
u32 unmap_granularity;
u32 unmap_alignment;
u32 index;
unsigned int physical_block_size;
unsigned int max_medium_access_timeouts;
unsigned int medium_access_timed_out;
u8 media_present;
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 */
unsigned RCD : 1; /* state of disk RCD bit, unused */
unsigned DPOFUA : 1; /* state of disk DPOFUA bit */
unsigned first_scan : 1;
unsigned lbpme : 1;
unsigned lbprz : 1;
unsigned lbpu : 1;
unsigned lbpws : 1;
unsigned lbpws10 : 1;
unsigned lbpvpd : 1;
unsigned ws10 : 1;
unsigned ws16 : 1;
unsigned rc_basis: 2;
unsigned zoned: 2;
unsigned urswrz : 1;
};
#define to_scsi_disk(obj) container_of(obj,struct scsi_disk,dev)
static inline struct scsi_disk *scsi_disk(struct gendisk *disk)
{
return container_of(disk->private_data, struct scsi_disk, driver);
}
#define sd_printk(prefix, sdsk, fmt, a...) \
(sdsk)->disk ? \
sdev_prefix_printk(prefix, (sdsk)->device, \
(sdsk)->disk->disk_name, fmt, ##a) : \
sdev_printk(prefix, (sdsk)->device, fmt, ##a)
#define sd_first_printk(prefix, sdsk, fmt, a...) \
do { \
if ((sdkp)->first_scan) \
sd_printk(prefix, sdsk, fmt, ##a); \
} while (0)
static inline int scsi_medium_access_command(struct scsi_cmnd *scmd)
{
switch (scmd->cmnd[0]) {
case READ_6:
case READ_10:
case READ_12:
case READ_16:
case SYNCHRONIZE_CACHE:
case VERIFY:
case VERIFY_12:
case VERIFY_16:
case WRITE_6:
case WRITE_10:
case WRITE_12:
case WRITE_16:
case WRITE_SAME:
case WRITE_SAME_16:
case UNMAP:
return 1;
case VARIABLE_LENGTH_CMD:
switch (scmd->cmnd[9]) {
case READ_32:
case VERIFY_32:
case WRITE_32:
case WRITE_SAME_32:
return 1;
}
}
return 0;
}
static inline sector_t logical_to_sectors(struct scsi_device *sdev, sector_t blocks)
{
return blocks << (ilog2(sdev->sector_size) - 9);
}
static inline unsigned int logical_to_bytes(struct scsi_device *sdev, sector_t blocks)
{
return blocks * sdev->sector_size;
}
static inline sector_t sectors_to_logical(struct scsi_device *sdev, sector_t sector)
{
return sector >> (ilog2(sdev->sector_size) - 9);
}
/*
* Look up the DIX operation based on whether the command is read or
* write and whether dix and dif are enabled.
*/
static inline unsigned int sd_prot_op(bool write, bool dix, bool dif)
{
/* Lookup table: bit 2 (write), bit 1 (dix), bit 0 (dif) */
const unsigned int ops[] = { /* wrt dix dif */
SCSI_PROT_NORMAL, /* 0 0 0 */
SCSI_PROT_READ_STRIP, /* 0 0 1 */
SCSI_PROT_READ_INSERT, /* 0 1 0 */
SCSI_PROT_READ_PASS, /* 0 1 1 */
SCSI_PROT_NORMAL, /* 1 0 0 */
SCSI_PROT_WRITE_INSERT, /* 1 0 1 */
SCSI_PROT_WRITE_STRIP, /* 1 1 0 */
SCSI_PROT_WRITE_PASS, /* 1 1 1 */
};
return ops[write << 2 | dix << 1 | dif];
}
/*
* Returns a mask of the protection flags that are valid for a given DIX
* operation.
*/
static inline unsigned int sd_prot_flag_mask(unsigned int prot_op)
{
const unsigned int flag_mask[] = {
[SCSI_PROT_NORMAL] = 0,
[SCSI_PROT_READ_STRIP] = SCSI_PROT_TRANSFER_PI |
SCSI_PROT_GUARD_CHECK |
SCSI_PROT_REF_CHECK |
SCSI_PROT_REF_INCREMENT,
[SCSI_PROT_READ_INSERT] = SCSI_PROT_REF_INCREMENT |
SCSI_PROT_IP_CHECKSUM,
[SCSI_PROT_READ_PASS] = SCSI_PROT_TRANSFER_PI |
SCSI_PROT_GUARD_CHECK |
SCSI_PROT_REF_CHECK |
SCSI_PROT_REF_INCREMENT |
SCSI_PROT_IP_CHECKSUM,
[SCSI_PROT_WRITE_INSERT] = SCSI_PROT_TRANSFER_PI |
SCSI_PROT_REF_INCREMENT,
[SCSI_PROT_WRITE_STRIP] = SCSI_PROT_GUARD_CHECK |
SCSI_PROT_REF_CHECK |
SCSI_PROT_REF_INCREMENT |
SCSI_PROT_IP_CHECKSUM,
[SCSI_PROT_WRITE_PASS] = SCSI_PROT_TRANSFER_PI |
SCSI_PROT_GUARD_CHECK |
SCSI_PROT_REF_CHECK |
SCSI_PROT_REF_INCREMENT |
SCSI_PROT_IP_CHECKSUM,
};
return flag_mask[prot_op];
}
#ifdef CONFIG_BLK_DEV_INTEGRITY
extern void sd_dif_config_host(struct scsi_disk *);
extern void sd_dif_prepare(struct scsi_cmnd *scmd);
extern void sd_dif_complete(struct scsi_cmnd *, unsigned int);
#else /* CONFIG_BLK_DEV_INTEGRITY */
static inline void sd_dif_config_host(struct scsi_disk *disk)
{
}
static inline int sd_dif_prepare(struct scsi_cmnd *scmd)
{
return 0;
}
static inline void sd_dif_complete(struct scsi_cmnd *cmd, unsigned int a)
{
}
#endif /* CONFIG_BLK_DEV_INTEGRITY */
static inline int sd_is_zoned(struct scsi_disk *sdkp)
{
return sdkp->zoned == 1 || sdkp->device->type == TYPE_ZBC;
}
#ifdef CONFIG_BLK_DEV_ZONED
extern int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buffer);
extern void sd_zbc_remove(struct scsi_disk *sdkp);
extern void sd_zbc_print_zones(struct scsi_disk *sdkp);
extern int sd_zbc_setup_write_cmnd(struct scsi_cmnd *cmd);
extern void sd_zbc_cancel_write_cmnd(struct scsi_cmnd *cmd);
extern int sd_zbc_setup_report_cmnd(struct scsi_cmnd *cmd);
extern int sd_zbc_setup_reset_cmnd(struct scsi_cmnd *cmd);
extern void sd_zbc_complete(struct scsi_cmnd *cmd, unsigned int good_bytes,
struct scsi_sense_hdr *sshdr);
#else /* CONFIG_BLK_DEV_ZONED */
static inline int sd_zbc_read_zones(struct scsi_disk *sdkp,
unsigned char *buf)
{
return 0;
}
static inline void sd_zbc_remove(struct scsi_disk *sdkp) {}
static inline void sd_zbc_print_zones(struct scsi_disk *sdkp) {}
static inline int sd_zbc_setup_write_cmnd(struct scsi_cmnd *cmd)
{
/* Let the drive fail requests */
return BLKPREP_OK;
}
static inline void sd_zbc_cancel_write_cmnd(struct scsi_cmnd *cmd) {}
static inline int sd_zbc_setup_report_cmnd(struct scsi_cmnd *cmd)
{
return BLKPREP_INVALID;
}
static inline int sd_zbc_setup_reset_cmnd(struct scsi_cmnd *cmd)
{
return BLKPREP_INVALID;
}
static inline void sd_zbc_complete(struct scsi_cmnd *cmd,
unsigned int good_bytes,
struct scsi_sense_hdr *sshdr) {}
#endif /* CONFIG_BLK_DEV_ZONED */
#endif /* _SCSI_DISK_H */