diff mbox series

[v5,05/18] scsi: Add support for block PR read keys/reservation

Message ID 20230324181741.13908-6-michael.christie@oracle.com (mailing list archive)
State Superseded
Headers show
Series Use block pr_ops in LIO | expand

Commit Message

Mike Christie March 24, 2023, 6:17 p.m. UTC
This adds support in sd.c for the block PR read keys and read reservation
callouts, so upper layers like LIO can get the PR info that's been setup
using the existing pr callouts and return it to initiators.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 drivers/scsi/sd.c            | 91 ++++++++++++++++++++++++++++++++++++
 include/scsi/scsi_block_pr.h | 20 ++++++++
 include/scsi/scsi_proto.h    |  5 ++
 3 files changed, 116 insertions(+)
diff mbox series

Patch

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 7ebf59114da1..2895a8f1bbfa 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1723,6 +1723,95 @@  static int sd_scsi_to_pr_err(struct scsi_sense_hdr *sshdr, int result)
 	}
 }
 
+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 };
+	const struct scsi_exec_args exec_args = {
+		.sshdr = &sshdr,
+	};
+	int result;
+
+	put_unaligned_be16(data_len, &cmd[7]);
+
+	result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_IN, data, data_len,
+				   SD_TIMEOUT, sdkp->max_retries, &exec_args);
+	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);
+	}
+
+	if (result <= 0)
+		return result;
+
+	return sd_scsi_to_pr_err(&sshdr, result);
+}
+
+static int sd_pr_read_keys(struct block_device *bdev, struct pr_keys *keys_info)
+{
+	int result, i, data_offset, num_copy_keys;
+	u32 num_keys = keys_info->num_keys;
+	int data_len = num_keys * 8 + 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(num_keys, 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] = { };
+	int result, len;
+
+	result = sd_pr_in_command(bdev, READ_RESERVATION, data, sizeof(data));
+	if (result)
+		return result;
+
+	len = get_unaligned_be32(&data[4]);
+	if (!len)
+		return 0;
+
+	/* 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)
 {
@@ -1804,6 +1893,8 @@  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 44766d7a81d8..9695cda4e9ce 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)
 	return 0;
 }
 
+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;
+	}
+
+	return 0;
+}
+
 #endif
diff --git a/include/scsi/scsi_proto.h b/include/scsi/scsi_proto.h
index fbe5bdfe4d6e..07d65c1f59db 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