[SCSI] sd: Support disks formatted with DIF Type 2

Disks formatted with DIF Type 2 reject READ/WRITE 6/10/12/16 commands
when protection is enabled.  Only the 32-byte variants are supported.

Implement support for issusing 32-byte READ/WRITE and enable Type 2
drives in the protection type detection logic.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

3 files changed, 78 insertions, 11 deletions

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 1e0a0b07dab6..9093c7261f33 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -116,6 +116,9 @@ static DEFINE_IDA(sd_index_ida);
  * object after last put) */
 static DEFINE_MUTEX(sd_ref_mutex);
 
+struct kmem_cache *sd_cdb_cache;
+mempool_t *sd_cdb_pool;
+
 static const char *sd_cache_types[] = {
         "write through", "none", "write back",
         "write back, no read (daft)"
@@ -413,6 +416,7 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
         sector_t threshold;
         unsigned int this_count = blk_rq_sectors(rq);
         int ret, host_dif;
+        unsigned char protect;
 
         if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
                 ret = scsi_setup_blk_pc_cmnd(sdp, rq);
@@ -545,13 +549,49 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
         /* Set RDPROTECT/WRPROTECT if disk is formatted with DIF */
         host_dif = scsi_host_dif_capable(sdp->host, sdkp->protection_type);
         if (host_dif)
-                SCpnt->cmnd[1] = 1 << 5;
+                protect = 1 << 5;
         else
-                SCpnt->cmnd[1] = 0;
+                protect = 0;
+
+        if (host_dif == SD_DIF_TYPE2_PROTECTION) {
+                SCpnt->cmnd = mempool_alloc(sd_cdb_pool, GFP_ATOMIC);
+
+                if (unlikely(SCpnt->cmnd == NULL)) {
+                        ret = BLKPREP_DEFER;
+                        goto out;
+                }
 
-        if (block > 0xffffffff) {
+                SCpnt->cmd_len = SD_EXT_CDB_SIZE;
+                memset(SCpnt->cmnd, 0, SCpnt->cmd_len);
+                SCpnt->cmnd[0] = VARIABLE_LENGTH_CMD;
+                SCpnt->cmnd[7] = 0x18;
+                SCpnt->cmnd[9] = (rq_data_dir(rq) == READ) ? READ_32 : WRITE_32;
+                SCpnt->cmnd[10] = protect | (blk_fua_rq(rq) ? 0x8 : 0);
+
+                /* LBA */
+                SCpnt->cmnd[12] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0;
+                SCpnt->cmnd[13] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0;
+                SCpnt->cmnd[14] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0;
+                SCpnt->cmnd[15] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0;
+                SCpnt->cmnd[16] = (unsigned char) (block >> 24) & 0xff;
+                SCpnt->cmnd[17] = (unsigned char) (block >> 16) & 0xff;
+                SCpnt->cmnd[18] = (unsigned char) (block >> 8) & 0xff;
+                SCpnt->cmnd[19] = (unsigned char) block & 0xff;
+
+                /* Expected Indirect LBA */
+                SCpnt->cmnd[20] = (unsigned char) (block >> 24) & 0xff;
+                SCpnt->cmnd[21] = (unsigned char) (block >> 16) & 0xff;
+                SCpnt->cmnd[22] = (unsigned char) (block >> 8) & 0xff;
+                SCpnt->cmnd[23] = (unsigned char) block & 0xff;
+
+                /* Transfer length */
+                SCpnt->cmnd[28] = (unsigned char) (this_count >> 24) & 0xff;
+                SCpnt->cmnd[29] = (unsigned char) (this_count >> 16) & 0xff;
+                SCpnt->cmnd[30] = (unsigned char) (this_count >> 8) & 0xff;
+                SCpnt->cmnd[31] = (unsigned char) this_count & 0xff;
+        } else if (block > 0xffffffff) {
                 SCpnt->cmnd[0] += READ_16 - READ_6;
-                SCpnt->cmnd[1] |= blk_fua_rq(rq) ? 0x8 : 0;
+                SCpnt->cmnd[1] = protect | (blk_fua_rq(rq) ? 0x8 : 0);
                 SCpnt->cmnd[2] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0;
                 SCpnt->cmnd[3] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0;
                 SCpnt->cmnd[4] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0;
@@ -572,7 +612,7 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
                         this_count = 0xffff;
 
                 SCpnt->cmnd[0] += READ_10 - READ_6;
-                SCpnt->cmnd[1] |= blk_fua_rq(rq) ? 0x8 : 0;
+                SCpnt->cmnd[1] = protect | (blk_fua_rq(rq) ? 0x8 : 0);
                 SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
                 SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
                 SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
@@ -1047,6 +1087,7 @@ static int sd_done(struct scsi_cmnd *SCpnt)
         int result = SCpnt->result;
         unsigned int good_bytes = result ? 0 : scsi_bufflen(SCpnt);
         struct scsi_sense_hdr sshdr;
+        struct scsi_disk *sdkp = scsi_disk(SCpnt->request->rq_disk);
         int sense_valid = 0;
         int sense_deferred = 0;
 
@@ -1108,6 +1149,10 @@ static int sd_done(struct scsi_cmnd *SCpnt)
         if (rq_data_dir(SCpnt->request) == READ && scsi_prot_sg_count(SCpnt))
                 sd_dif_complete(SCpnt, good_bytes);
 
+        if (scsi_host_dif_capable(sdkp->device->host, sdkp->protection_type)
+            == SD_DIF_TYPE2_PROTECTION && SCpnt->cmnd != SCpnt->request->cmd)
+                mempool_free(SCpnt->cmnd, sd_cdb_pool);
+
         return good_bytes;
 }
 
@@ -1271,12 +1316,7 @@ void sd_read_protection_type(struct scsi_disk *sdkp, unsigned char *buffer)
 
         sdkp->protection_type = type;
 
-        switch (type) {
-        case SD_DIF_TYPE1_PROTECTION:
-        case SD_DIF_TYPE3_PROTECTION:
-                break;
-
-        default:
+        if (type > SD_DIF_TYPE3_PROTECTION) {
                 sd_printk(KERN_ERR, sdkp, "formatted with unsupported " \
                           "protection type %u. Disabling disk!\n", type);
                 sdkp->capacity = 0;
@@ -2323,8 +2363,24 @@ static int __init init_sd(void)
         if (err)
                 goto err_out_class;
 
+        sd_cdb_cache = kmem_cache_create("sd_ext_cdb", SD_EXT_CDB_SIZE,
+                                         0, 0, NULL);
+        if (!sd_cdb_cache) {
+                printk(KERN_ERR "sd: can't init extended cdb cache\n");
+                goto err_out_class;
+        }
+
+        sd_cdb_pool = mempool_create_slab_pool(SD_MEMPOOL_SIZE, sd_cdb_cache);
+        if (!sd_cdb_pool) {
+                printk(KERN_ERR "sd: can't init extended cdb pool\n");
+                goto err_out_cache;
+        }
+
         return 0;
 
+err_out_cache:
+        kmem_cache_destroy(sd_cdb_cache);
+
 err_out_class:
         class_unregister(&sd_disk_class);
 err_out:
@@ -2344,6 +2400,9 @@ static void __exit exit_sd(void)
 
         SCSI_LOG_HLQUEUE(3, printk("exit_sd: exiting sd driver\n"));
 
+        mempool_destroy(sd_cdb_pool);
+        kmem_cache_destroy(sd_cdb_cache);
+
         scsi_unregister_driver(&sd_template.gendrv);
         class_unregister(&sd_disk_class);
 
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index ce1f5f899fe3..e374804d26fb 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -37,6 +37,11 @@
  */
 #define SD_LAST_BUGGY_SECTORS   8
 
+enum {
+        SD_EXT_CDB_SIZE = 32,   /* Extended CDB size */
+        SD_MEMPOOL_SIZE = 2,    /* CDB pool size */
+};
+
 struct scsi_disk {
         struct scsi_driver *driver;     /* always &sd_template */
         struct scsi_device *device;
diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h
index 084478e14d24..34c46ab5c31b 100644
--- a/include/scsi/scsi.h
+++ b/include/scsi/scsi.h
@@ -129,6 +129,9 @@ struct scsi_cmnd;
 #define MI_REPORT_TARGET_PGS  0x0a
 /* values for maintenance out */
 #define MO_SET_TARGET_PGS     0x0a
+/* values for variable length command */
+#define READ_32               0x09
+#define WRITE_32              0x0b
 
 /* Values for T10/04-262r7 */
 #define ATA_16                0x85      /* 16-byte pass-thru */