From 924d55b06347d813b38c51e75ce1a6666c113933 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 15 Oct 2015 14:10:49 +0200 Subject: [PATCH] sd: implement the Persistent Reservation API This is a mostly trivial mapping to the PERSISTENT RESERVE IN/OUT commands. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/scsi/sd.c | 96 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 96 insertions(+) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 3f370228bf31..a1eeb202160f 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -51,6 +51,7 @@ #include #include #include +#include #include #include @@ -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, }; /** -- 2.20.1