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sd: implement the Persistent Reservation API

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This is a mostly trivial mapping to the PERSISTENT RESERVE IN/OUT
commands.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Christoph Hellwig 2015-10-15 14:10:49 +02:00 committed by Jens Axboe
parent bbd3e06436
commit 924d55b063
1 changed files with 96 additions and 0 deletions
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96
drivers/scsi/sd.c
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@ -51,6 +51,7 @@
#include <linux/async.h>
#include <linux/slab.h>
#include <linux/pm_runtime.h>
#include <linux/pr.h>
#include <asm/uaccess.h>
#include <asm/unaligned.h>
@ -1535,6 +1536,100 @@ static int sd_compat_ioctl(struct block_device *bdev, fmode_t mode,
}
#endif
static char sd_pr_type(enum pr_type type)
{
switch (type) {
case PR_WRITE_EXCLUSIVE:
return 0x01;
case PR_EXCLUSIVE_ACCESS:
return 0x03;
case PR_WRITE_EXCLUSIVE_REG_ONLY:
return 0x05;
case PR_EXCLUSIVE_ACCESS_REG_ONLY:
return 0x06;
case PR_WRITE_EXCLUSIVE_ALL_REGS:
return 0x07;
case PR_EXCLUSIVE_ACCESS_ALL_REGS:
return 0x08;
default:
return 0;
}
};
static int sd_pr_command(struct block_device *bdev, u8 sa,
u64 key, u64 sa_key, u8 type, u8 flags)
{
struct scsi_device *sdev = scsi_disk(bdev->bd_disk)->device;
struct scsi_sense_hdr sshdr;
int result;
u8 cmd[16] = { 0, };
u8 data[24] = { 0, };
cmd[0] = PERSISTENT_RESERVE_OUT;
cmd[1] = sa;
cmd[2] = type;
put_unaligned_be32(sizeof(data), &cmd[5]);
put_unaligned_be64(key, &data[0]);
put_unaligned_be64(sa_key, &data[8]);
data[20] = flags;
result = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, &data, sizeof(data),
&sshdr, SD_TIMEOUT, SD_MAX_RETRIES, NULL);
if ((driver_byte(result) & DRIVER_SENSE) &&
(scsi_sense_valid(&sshdr))) {
sdev_printk(KERN_INFO, sdev, "PR command failed: %d\n", result);
scsi_print_sense_hdr(sdev, NULL, &sshdr);
}
return result;
}
static int sd_pr_register(struct block_device *bdev, u64 old_key, u64 new_key,
u32 flags)
{
if (flags & ~PR_FL_IGNORE_KEY)
return -EOPNOTSUPP;
return sd_pr_command(bdev, (flags & PR_FL_IGNORE_KEY) ? 0x06 : 0x00,
old_key, new_key, 0,
(1 << 0) /* APTPL */ |
(1 << 2) /* ALL_TG_PT */);
}
static int sd_pr_reserve(struct block_device *bdev, u64 key, enum pr_type type,
u32 flags)
{
if (flags)
return -EOPNOTSUPP;
return sd_pr_command(bdev, 0x01, key, 0, sd_pr_type(type), 0);
}
static int sd_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
{
return sd_pr_command(bdev, 0x02, key, 0, sd_pr_type(type), 0);
}
static int sd_pr_preempt(struct block_device *bdev, u64 old_key, u64 new_key,
enum pr_type type, bool abort)
{
return sd_pr_command(bdev, abort ? 0x05 : 0x04, old_key, new_key,
sd_pr_type(type), 0);
}
static int sd_pr_clear(struct block_device *bdev, u64 key)
{
return sd_pr_command(bdev, 0x03, key, 0, 0, 0);
}
static const struct pr_ops sd_pr_ops = {
.pr_register = sd_pr_register,
.pr_reserve = sd_pr_reserve,
.pr_release = sd_pr_release,
.pr_preempt = sd_pr_preempt,
.pr_clear = sd_pr_clear,
};
static const struct block_device_operations sd_fops = {
.owner = THIS_MODULE,
.open = sd_open,
@ -1547,6 +1642,7 @@ static const struct block_device_operations sd_fops = {
.check_events = sd_check_events,
.revalidate_disk = sd_revalidate_disk,
.unlock_native_capacity = sd_unlock_native_capacity,
.pr_ops = &sd_pr_ops,
};
/**