bsg: replace SG v3 with SG v4

This patch replaces SG v3 in bsg with SG v4 (except for SG_IO).

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 121 insertions, 77 deletions

diff --git a/block/bsg.c b/block/bsg.c
index 53a09a52d154..6d139d20ec99 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -103,8 +103,8 @@ struct bsg_command {
         struct request *rq;
         struct bio *bio;
         int err;
-        struct sg_io_hdr hdr;
-        struct sg_io_hdr __user *uhdr;
+        struct sg_io_v4 hdr;
+        struct sg_io_v4 __user *uhdr;
         char sense[SCSI_SENSE_BUFFERSIZE];
 };
 
@@ -235,57 +235,82 @@ static struct bsg_command *bsg_get_command(struct bsg_device *bd)
         return bc;
 }
 
+static int blk_fill_sgv4_hdr_rq(request_queue_t *q, struct request *rq,
+                                struct sg_io_v4 *hdr, int has_write_perm)
+{
+        memset(rq->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */
+
+        if (copy_from_user(rq->cmd, (void *)(unsigned long)hdr->request,
+                           hdr->request_len))
+                return -EFAULT;
+        if (blk_verify_command(rq->cmd, has_write_perm))
+                return -EPERM;
+
+        /*
+         * fill in request structure
+         */
+        rq->cmd_len = hdr->request_len;
+        rq->cmd_type = REQ_TYPE_BLOCK_PC;
+
+        rq->timeout = (hdr->timeout * HZ) / 1000;
+        if (!rq->timeout)
+                rq->timeout = q->sg_timeout;
+        if (!rq->timeout)
+                rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
+
+        return 0;
+}
+
 /*
- * Check if sg_io_hdr from user is allowed and valid
+ * Check if sg_io_v4 from user is allowed and valid
  */
 static int
-bsg_validate_sghdr(request_queue_t *q, struct sg_io_hdr *hdr, int *rw)
+bsg_validate_sgv4_hdr(request_queue_t *q, struct sg_io_v4 *hdr, int *rw)
 {
-        if (hdr->interface_id != 'S')
+        if (hdr->guard != 'Q')
                 return -EINVAL;
-        if (hdr->cmd_len > BLK_MAX_CDB)
+        if (hdr->request_len > BLK_MAX_CDB)
                 return -EINVAL;
-        if (hdr->dxfer_len > (q->max_sectors << 9))
+        if (hdr->dout_xfer_len > (q->max_sectors << 9) ||
+            hdr->din_xfer_len > (q->max_sectors << 9))
                 return -EIO;
 
+        /* not supported currently */
+        if (hdr->protocol || hdr->subprotocol)
+                return -EINVAL;
+
         /*
          * looks sane, if no data then it should be fine from our POV
          */
-        if (!hdr->dxfer_len)
+        if (!hdr->dout_xfer_len && !hdr->din_xfer_len)
                 return 0;
 
-        switch (hdr->dxfer_direction) {
-                case SG_DXFER_TO_FROM_DEV:
-                case SG_DXFER_FROM_DEV:
-                        *rw = READ;
-                        break;
-                case SG_DXFER_TO_DEV:
-                        *rw = WRITE;
-                        break;
-                default:
-                        return -EINVAL;
-        }
+        /* not supported currently */
+        if (hdr->dout_xfer_len && hdr->din_xfer_len)
+                return -EINVAL;
+
+        *rw = hdr->dout_xfer_len ? WRITE : READ;
 
         return 0;
 }
 
 /*
- * map sg_io_hdr to a request. for scatter-gather sg_io_hdr, we map
- * each segment to a bio and string multiple bio's to the request
+ * map sg_io_v4 to a request.
  */
 static struct request *
-bsg_map_hdr(struct bsg_device *bd, int rw, struct sg_io_hdr *hdr)
+bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr)
 {
         request_queue_t *q = bd->queue;
-        struct sg_iovec iov;
-        struct sg_iovec __user *u_iov;
         struct request *rq;
-        int ret, i = 0;
+        int ret, rw;
+        unsigned int dxfer_len;
+        void *dxferp = NULL;
 
-        dprintk("map hdr %p/%d/%d\n", hdr->dxferp, hdr->dxfer_len,
-                                        hdr->iovec_count);
+        dprintk("map hdr %llx/%u %llx/%u\n", (unsigned long long) hdr->dout_xferp,
+                hdr->dout_xfer_len, (unsigned long long) hdr->din_xferp,
+                hdr->din_xfer_len);
 
-        ret = bsg_validate_sghdr(q, hdr, &rw);
+        ret = bsg_validate_sgv4_hdr(q, hdr, &rw);
         if (ret)
                 return ERR_PTR(ret);
 
@@ -293,44 +318,29 @@ bsg_map_hdr(struct bsg_device *bd, int rw, struct sg_io_hdr *hdr)
          * map scatter-gather elements seperately and string them to request
          */
         rq = blk_get_request(q, rw, GFP_KERNEL);
-        ret = blk_fill_sghdr_rq(q, rq, hdr, test_bit(BSG_F_WRITE_PERM,
-                                &bd->flags));
+        ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, test_bit(BSG_F_WRITE_PERM,
+                                                       &bd->flags));
         if (ret) {
                 blk_put_request(rq);
                 return ERR_PTR(ret);
         }
 
-        if (!hdr->iovec_count) {
-                ret = blk_rq_map_user(q, rq, hdr->dxferp, hdr->dxfer_len);
-                if (ret)
-                        goto out;
-        }
-
-        u_iov = hdr->dxferp;
-        for (ret = 0, i = 0; i < hdr->iovec_count; i++, u_iov++) {
-                if (copy_from_user(&iov, u_iov, sizeof(iov))) {
-                        ret = -EFAULT;
-                        break;
-                }
-
-                if (!iov.iov_len || !iov.iov_base) {
-                        ret = -EINVAL;
-                        break;
+        if (hdr->dout_xfer_len) {
+                dxfer_len = hdr->dout_xfer_len;
+                dxferp = (void*)(unsigned long)hdr->dout_xferp;
+        } else if (hdr->din_xfer_len) {
+                dxfer_len = hdr->din_xfer_len;
+                dxferp = (void*)(unsigned long)hdr->din_xferp;
+        } else
+                dxfer_len = 0;
+
+        if (dxfer_len) {
+                ret = blk_rq_map_user(q, rq, dxferp, dxfer_len);
+                if (ret) {
+                        dprintk("failed map at %d\n", ret);
+                        blk_put_request(rq);
+                        rq = ERR_PTR(ret);
                 }
-
-                ret = blk_rq_map_user(q, rq, iov.iov_base, iov.iov_len);
-                if (ret)
-                        break;
-        }
-
-        /*
-         * bugger, cleanup
-         */
-        if (ret) {
-out:
-                dprintk("failed map at %d: %d\n", i, ret);
-                blk_unmap_sghdr_rq(rq, hdr);
-                rq = ERR_PTR(ret);
         }
 
         return rq;
@@ -346,7 +356,7 @@ static void bsg_rq_end_io(struct request *rq, int uptodate)
         struct bsg_device *bd = bc->bd;
         unsigned long flags;
 
-        dprintk("%s: finished rq %p bc %p, bio %p offset %d stat %d\n",
+        dprintk("%s: finished rq %p bc %p, bio %p offset %Zd stat %d\n",
                 bd->name, rq, bc, bc->bio, bc - bd->cmd_map, uptodate);
 
         bc->hdr.duration = jiffies_to_msecs(jiffies - bc->hdr.duration);
@@ -434,6 +444,42 @@ bsg_get_done_cmd_nosignals(struct bsg_device *bd)
         return __bsg_get_done_cmd(bd, TASK_UNINTERRUPTIBLE);
 }
 
+static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
+                                    struct bio *bio)
+{
+        int ret = 0;
+
+        dprintk("rq %p bio %p %u\n", rq, bio, rq->errors);
+        /*
+         * fill in all the output members
+         */
+        hdr->device_status = status_byte(rq->errors);
+        hdr->transport_status = host_byte(rq->errors);
+        hdr->driver_status = driver_byte(rq->errors);
+        hdr->info = 0;
+        if (hdr->device_status || hdr->transport_status || hdr->driver_status)
+                hdr->info |= SG_INFO_CHECK;
+        hdr->din_resid = rq->data_len;
+        hdr->response_len = 0;
+
+        if (rq->sense_len && hdr->response) {
+                int len = min((unsigned int) hdr->max_response_len,
+                              rq->sense_len);
+
+                ret = copy_to_user((void*)(unsigned long)hdr->response,
+                                   rq->sense, len);
+                if (!ret)
+                        hdr->response_len = len;
+                else
+                        ret = -EFAULT;
+        }
+
+        blk_rq_unmap_user(bio);
+        blk_put_request(rq);
+
+        return ret;
+}
+
 static int bsg_complete_all_commands(struct bsg_device *bd)
 {
         struct bsg_command *bc;
@@ -476,7 +522,7 @@ static int bsg_complete_all_commands(struct bsg_device *bd)
                         break;
                 }
 
-                tret = blk_complete_sghdr_rq(bc->rq, &bc->hdr, bc->bio);
+                tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio);
                 if (!ret)
                         ret = tret;
 
@@ -495,11 +541,11 @@ __bsg_read(char __user *buf, size_t count, bsg_command_callback get_bc,
         struct bsg_command *bc;
         int nr_commands, ret;
 
-        if (count % sizeof(struct sg_io_hdr))
+        if (count % sizeof(struct sg_io_v4))
                 return -EINVAL;
 
         ret = 0;
-        nr_commands = count / sizeof(struct sg_io_hdr);
+        nr_commands = count / sizeof(struct sg_io_v4);
         while (nr_commands) {
                 bc = get_bc(bd, iov);
                 if (IS_ERR(bc)) {
@@ -512,7 +558,7 @@ __bsg_read(char __user *buf, size_t count, bsg_command_callback get_bc,
                  * after completing the request. so do that here,
                  * bsg_complete_work() cannot do that for us
                  */
-                ret = blk_complete_sghdr_rq(bc->rq, &bc->hdr, bc->bio);
+                ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio);
 
                 if (copy_to_user(buf, (char *) &bc->hdr, sizeof(bc->hdr)))
                         ret = -EFAULT;
@@ -522,8 +568,8 @@ __bsg_read(char __user *buf, size_t count, bsg_command_callback get_bc,
                 if (ret)
                         break;
 
-                buf += sizeof(struct sg_io_hdr);
-                *bytes_read += sizeof(struct sg_io_hdr);
+                buf += sizeof(struct sg_io_v4);
+                *bytes_read += sizeof(struct sg_io_v4);
                 nr_commands--;
         }
 
@@ -582,16 +628,15 @@ static ssize_t __bsg_write(struct bsg_device *bd, const char __user *buf,
         struct request *rq;
         int ret, nr_commands;
 
-        if (count % sizeof(struct sg_io_hdr))
+        if (count % sizeof(struct sg_io_v4))
                 return -EINVAL;
 
-        nr_commands = count / sizeof(struct sg_io_hdr);
+        nr_commands = count / sizeof(struct sg_io_v4);
         rq = NULL;
         bc = NULL;
         ret = 0;
         while (nr_commands) {
                 request_queue_t *q = bd->queue;
-                int rw = READ;
 
                 bc = bsg_get_command(bd);
                 if (!bc)
@@ -602,7 +647,7 @@ static ssize_t __bsg_write(struct bsg_device *bd, const char __user *buf,
                         break;
                 }
 
-                bc->uhdr = (struct sg_io_hdr __user *) buf;
+                bc->uhdr = (struct sg_io_v4 __user *) buf;
                 if (copy_from_user(&bc->hdr, buf, sizeof(bc->hdr))) {
                         ret = -EFAULT;
                         break;
@@ -611,7 +656,7 @@ static ssize_t __bsg_write(struct bsg_device *bd, const char __user *buf,
                 /*
                  * get a request, fill in the blanks, and add to request queue
                  */
-                rq = bsg_map_hdr(bd, rw, &bc->hdr);
+                rq = bsg_map_hdr(bd, &bc->hdr);
                 if (IS_ERR(rq)) {
                         ret = PTR_ERR(rq);
                         rq = NULL;
@@ -622,12 +667,10 @@ static ssize_t __bsg_write(struct bsg_device *bd, const char __user *buf,
                 bc = NULL;
                 rq = NULL;
                 nr_commands--;
-                buf += sizeof(struct sg_io_hdr);
-                *bytes_read += sizeof(struct sg_io_hdr);
+                buf += sizeof(struct sg_io_v4);
+                *bytes_read += sizeof(struct sg_io_v4);
         }
 
-        if (rq)
-                blk_unmap_sghdr_rq(rq, &bc->hdr);
         if (bc)
                 bsg_free_command(bc);
 
@@ -898,11 +941,12 @@ bsg_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
         case SG_GET_RESERVED_SIZE:
         case SG_SET_RESERVED_SIZE:
         case SG_EMULATED_HOST:
-        case SG_IO:
         case SCSI_IOCTL_SEND_COMMAND: {
                 void __user *uarg = (void __user *) arg;
                 return scsi_cmd_ioctl(file, bd->disk, cmd, uarg);
         }
+        case SG_IO:
+                return -EINVAL;
         /*
          * block device ioctls
          */