[PATCH v3 04/19] scsi: Add support for block PR read keys/reservation

Mike Christie
2022-10-26T23:20:20Z

This adds support in sd.c for the block PR read keys and read reservation
callouts.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
---
drivers/scsi/sd.c | 104 +++++++++++++++++++++++++++++++++++
include/scsi/scsi_block_pr.h | 20 +++++++
include/scsi/scsi_proto.h | 5 ++
3 files changed, 129 insertions(+)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index ad9374b07585..86b602399000 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1695,6 +1695,108 @@ static int sd_get_unique_id(struct gendisk *disk, u8 id[16],
return ret;
}

+static int sd_pr_in_command(struct block_device *bdev, u8 sa,
+ unsigned char *data, int data_len)
+{
+ struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
+ struct scsi_device *sdev = sdkp->device;
+ struct scsi_sense_hdr sshdr;
+ u8 cmd[10] = { PERSISTENT_RESERVE_IN, sa };
+ struct scsi_failure failures[] = {
+ {
+ .sense = UNIT_ATTENTION,
+ .asc = SCMD_FAILURE_ASC_ANY,
+ .ascq = SCMD_FAILURE_ASCQ_ANY,
+ .allowed = 5,
+ .result = SAM_STAT_CHECK_CONDITION,
+ },
+ {},
+ };
+ int result;
+
+ put_unaligned_be16(data_len, &cmd[7]);
+
+ result = scsi_exec_req(((struct scsi_exec_args) {
+ .sdev = sdev,
+ .cmd = cmd,
+ .data_dir = DMA_FROM_DEVICE,
+ .buf = data,
+ .buf_len = data_len,
+ .sshdr = &sshdr,
+ .timeout = SD_TIMEOUT,
+ .retries = sdkp->max_retries,
+ .failures = failures }));
+ if (scsi_status_is_check_condition(result) &&
+ 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_read_keys(struct block_device *bdev, struct pr_keys *keys_info,
+ u32 keys_len)
+{
+ int result, i, data_offset, num_copy_keys;
+ int data_len = keys_len + 8;
+ u8 *data;
+
+ data = kzalloc(data_len, GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ result = sd_pr_in_command(bdev, READ_KEYS, data, data_len);
+ if (result)
+ goto free_data;
+
+ keys_info->generation = get_unaligned_be32(&data[0]);
+ keys_info->num_keys = get_unaligned_be32(&data[4]) / 8;
+
+ data_offset = 8;
+ num_copy_keys = min(keys_len / 8, keys_info->num_keys);
+
+ for (i = 0; i < num_copy_keys; i++) {
+ keys_info->keys[i] = get_unaligned_be64(&data[data_offset]);
+ data_offset += 8;
+ }
+
+free_data:
+ kfree(data);
+ return result;
+}
+
+static int sd_pr_read_reservation(struct block_device *bdev,
+ struct pr_held_reservation *rsv)
+{
+ struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
+ struct scsi_device *sdev = sdkp->device;
+ u8 data[24] = { 0, };
+ int result, len;
+
+ result = sd_pr_in_command(bdev, READ_RESERVATION, data, sizeof(data));
+ if (result)
+ return result;
+
+ memset(rsv, 0, sizeof(*rsv));
+ len = get_unaligned_be32(&data[4]);
+ if (!len)
+ return result;
+
+ /* Make sure we have at least the key and type */
+ if (len < 14) {
+ sdev_printk(KERN_INFO, sdev,
+ "READ RESERVATION failed due to short return buffer of %d bytes\n",
+ len);
+ return -EINVAL;
+ }
+
+ rsv->generation = get_unaligned_be32(&data[0]);
+ rsv->key = get_unaligned_be64(&data[8]);
+ rsv->type = scsi_pr_type_to_block(data[21] & 0x0f);
+ return 0;
+}
+
static int sd_pr_out_command(struct block_device *bdev, u8 sa,
u64 key, u64 sa_key, enum scsi_pr_type type, u8 flags)
{
@@ -1787,6 +1889,8 @@ static const struct pr_ops sd_pr_ops = {
.pr_release = sd_pr_release,
.pr_preempt = sd_pr_preempt,
.pr_clear = sd_pr_clear,
+ .pr_read_keys = sd_pr_read_keys,
+ .pr_read_reservation = sd_pr_read_reservation,
};

static void scsi_disk_free_disk(struct gendisk *disk)
diff --git a/include/scsi/scsi_block_pr.h b/include/scsi/scsi_block_pr.h
index 6e99f844330d..137bf2247273 100644
--- a/include/scsi/scsi_block_pr.h
+++ b/include/scsi/scsi_block_pr.h
@@ -33,4 +33,24 @@ static inline enum scsi_pr_type block_pr_type_to_scsi(enum pr_type type)
}
};

+static inline enum pr_type scsi_pr_type_to_block(enum scsi_pr_type type)
+{
+ switch (type) {
+ case SCSI_PR_WRITE_EXCLUSIVE:
+ return PR_WRITE_EXCLUSIVE;
+ case SCSI_PR_EXCLUSIVE_ACCESS:
+ return PR_EXCLUSIVE_ACCESS;
+ case SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY:
+ return PR_WRITE_EXCLUSIVE_REG_ONLY;
+ case SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY:
+ return PR_EXCLUSIVE_ACCESS_REG_ONLY;
+ case SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS:
+ return PR_WRITE_EXCLUSIVE_ALL_REGS;
+ case SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS:
+ return PR_EXCLUSIVE_ACCESS_ALL_REGS;
+ default:
+ return 0;
+ }
+}
+
#endif
diff --git a/include/scsi/scsi_proto.h b/include/scsi/scsi_proto.h
index c03e35fc382c..0fd6e295375a 100644
--- a/include/scsi/scsi_proto.h
+++ b/include/scsi/scsi_proto.h
@@ -151,6 +151,11 @@
#define ZO_FINISH_ZONE 0x02
#define ZO_OPEN_ZONE 0x03
#define ZO_RESET_WRITE_POINTER 0x04
+/* values for PR in service action */
+#define READ_KEYS 0x00
+#define READ_RESERVATION 0x01
+#define REPORT_CAPABILITES 0x02
+#define READ_FULL_STATUS 0x03
/* values for variable length command */
#define XDREAD_32 0x03
#define XDWRITE_32 0x04
--
2.25.1