sd: Honor block layer integrity handling flags

A set of flags introduced in the block layer enable better control over
how protection information is handled. These flags are useful for both
error injection and data recovery purposes. Checking can be enabled and
disabled for controller and disk, and the guard tag format is now a
per-I/O property.

Update sd_protect_op to communicate the relevant information to the
low-level device driver via a set of flags in scsi_cmnd.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 26 insertions, 10 deletions

diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index 73f349044941..522a5f27f553 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -10,9 +10,10 @@
 #include <scsi/scsi_device.h>
 
 struct Scsi_Host;
-struct scsi_device;
 struct scsi_driver;
 
+#include <scsi/scsi_device.h>
+
 /*
  * MAX_COMMAND_SIZE is:
  * The longest fixed-length SCSI CDB as per the SCSI standard.
@@ -81,6 +82,7 @@ struct scsi_cmnd {
 
         unsigned char prot_op;
         unsigned char prot_type;
+        unsigned char prot_flags;
 
         unsigned short cmd_len;
         enum dma_data_direction sc_data_direction;
@@ -252,6 +254,14 @@ static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
         return scmd->prot_op;
 }
 
+enum scsi_prot_flags {
+        SCSI_PROT_TRANSFER_PI           = 1 << 0,
+        SCSI_PROT_GUARD_CHECK           = 1 << 1,
+        SCSI_PROT_REF_CHECK             = 1 << 2,
+        SCSI_PROT_REF_INCREMENT         = 1 << 3,
+        SCSI_PROT_IP_CHECKSUM           = 1 << 4,
+};
+
 /*
  * The controller usually does not know anything about the target it
  * is communicating with.  However, when DIX is enabled the controller
@@ -280,6 +290,17 @@ static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
         return blk_rq_pos(scmd->request);
 }
 
+static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
+{
+        return scmd->device->sector_size;
+}
+
+static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
+{
+        return blk_rq_pos(scmd->request) >>
+                (ilog2(scsi_prot_interval(scmd)) - 9) & 0xffffffff;
+}
+
 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
 {
         return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
@@ -316,17 +337,12 @@ static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
 {
         unsigned int xfer_len = scsi_out(scmd)->length;
-        unsigned int prot_op = scsi_get_prot_op(scmd);
-        unsigned int sector_size = scmd->device->sector_size;
+        unsigned int prot_interval = scsi_prot_interval(scmd);
 
-        switch (prot_op) {
-        case SCSI_PROT_NORMAL:
-        case SCSI_PROT_WRITE_STRIP:
-        case SCSI_PROT_READ_INSERT:
-                return xfer_len;
-        }
+        if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
+                xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
 
-        return xfer_len + (xfer_len >> ilog2(sector_size)) * 8;
+        return xfer_len;
 }
 
 #endif /* _SCSI_SCSI_CMND_H */