bsg: support for full generic block layer SG v3

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 102 insertions, 61 deletions

diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index e83f1dbf7c29..88fd008d38bd 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -41,8 +41,6 @@ const unsigned char scsi_command_size[8] =
 
 EXPORT_SYMBOL(scsi_command_size);
 
-#define BLK_DEFAULT_TIMEOUT     (60 * HZ)
-
 #include <scsi/sg.h>
 
 static int sg_get_version(int __user *p)
@@ -114,7 +112,7 @@ static int sg_emulated_host(request_queue_t *q, int __user *p)
 #define safe_for_read(cmd)      [cmd] = CMD_READ_SAFE
 #define safe_for_write(cmd)     [cmd] = CMD_WRITE_SAFE
 
-static int verify_command(struct file *file, unsigned char *cmd)
+static int verify_command(unsigned char *cmd, int has_write_perm)
 {
         static unsigned char cmd_type[256] = {
 
@@ -193,18 +191,11 @@ static int verify_command(struct file *file, unsigned char *cmd)
                 safe_for_write(GPCMD_SET_STREAMING),
         };
         unsigned char type = cmd_type[cmd[0]];
-        int has_write_perm = 0;
 
         /* Anybody who can open the device can do a read-safe command */
         if (type & CMD_READ_SAFE)
                 return 0;
 
-        /*
-         * file can be NULL from ioctl_by_bdev()...
-         */
-        if (file)
-                has_write_perm = file->f_mode & FMODE_WRITE;
-
         /* Write-safe commands just require a writable open.. */
         if ((type & CMD_WRITE_SAFE) && has_write_perm)
                 return 0;
@@ -222,24 +213,104 @@ static int verify_command(struct file *file, unsigned char *cmd)
         return -EPERM;
 }
 
+int blk_fill_sghdr_rq(request_queue_t *q, struct request *rq,
+                      struct sg_io_hdr *hdr, int has_write_perm)
+{
+        memset(rq->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */
+
+        if (copy_from_user(rq->cmd, hdr->cmdp, hdr->cmd_len))
+                return -EFAULT;
+        if (verify_command(rq->cmd, has_write_perm))
+                return -EPERM;
+
+        /*
+         * fill in request structure
+         */
+        rq->cmd_len = hdr->cmd_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;
+}
+EXPORT_SYMBOL_GPL(blk_fill_sghdr_rq);
+
+/*
+ * unmap a request that was previously mapped to this sg_io_hdr. handles
+ * both sg and non-sg sg_io_hdr.
+ */
+int blk_unmap_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr)
+{
+        struct bio *bio = rq->bio;
+
+        /*
+         * also releases request
+         */
+        if (!hdr->iovec_count)
+                return blk_rq_unmap_user(bio, hdr->dxfer_len);
+
+        rq_for_each_bio(bio, rq)
+                bio_unmap_user(bio);
+
+        blk_put_request(rq);
+        return 0;
+}
+EXPORT_SYMBOL_GPL(blk_unmap_sghdr_rq);
+
+int blk_complete_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr,
+                          struct bio *bio)
+{
+        int r, ret = 0;
+
+        /*
+         * fill in all the output members
+         */
+        hdr->status = rq->errors & 0xff;
+        hdr->masked_status = status_byte(rq->errors);
+        hdr->msg_status = msg_byte(rq->errors);
+        hdr->host_status = host_byte(rq->errors);
+        hdr->driver_status = driver_byte(rq->errors);
+        hdr->info = 0;
+        if (hdr->masked_status || hdr->host_status || hdr->driver_status)
+                hdr->info |= SG_INFO_CHECK;
+        hdr->resid = rq->data_len;
+        hdr->sb_len_wr = 0;
+
+        if (rq->sense_len && hdr->sbp) {
+                int len = min((unsigned int) hdr->mx_sb_len, rq->sense_len);
+
+                if (!copy_to_user(hdr->sbp, rq->sense, len))
+                        hdr->sb_len_wr = len;
+                else
+                        ret = -EFAULT;
+        }
+
+        rq->bio = bio;
+        r = blk_unmap_sghdr_rq(rq, hdr);
+        if (ret)
+                r = ret;
+
+        return r;
+}
+EXPORT_SYMBOL_GPL(blk_complete_sghdr_rq);
+
 static int sg_io(struct file *file, request_queue_t *q,
                 struct gendisk *bd_disk, struct sg_io_hdr *hdr)
 {
-        unsigned long start_time, timeout;
-        int writing = 0, ret = 0;
+        unsigned long start_time;
+        int writing = 0, ret = 0, has_write_perm = 0;
         struct request *rq;
         char sense[SCSI_SENSE_BUFFERSIZE];
-        unsigned char cmd[BLK_MAX_CDB];
         struct bio *bio;
 
         if (hdr->interface_id != 'S')
                 return -EINVAL;
         if (hdr->cmd_len > BLK_MAX_CDB)
                 return -EINVAL;
-        if (copy_from_user(cmd, hdr->cmdp, hdr->cmd_len))
-                return -EFAULT;
-        if (verify_command(file, cmd))
-                return -EPERM;
 
         if (hdr->dxfer_len > (q->max_hw_sectors << 9))
                 return -EIO;
@@ -260,25 +331,14 @@ static int sg_io(struct file *file, request_queue_t *q,
         if (!rq)
                 return -ENOMEM;
 
-        /*
-         * fill in request structure
-         */
-        rq->cmd_len = hdr->cmd_len;
-        memset(rq->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */
-        memcpy(rq->cmd, cmd, hdr->cmd_len);
-
-        memset(sense, 0, sizeof(sense));
-        rq->sense = sense;
-        rq->sense_len = 0;
-
-        rq->cmd_type = REQ_TYPE_BLOCK_PC;
+        if (file)
+                has_write_perm = file->f_mode & FMODE_WRITE;
 
-        timeout = msecs_to_jiffies(hdr->timeout);
-        rq->timeout = (timeout < INT_MAX) ? timeout : INT_MAX;
-        if (!rq->timeout)
-                rq->timeout = q->sg_timeout;
-        if (!rq->timeout)
-                rq->timeout = BLK_DEFAULT_TIMEOUT;
+        if (blk_fill_sghdr_rq(q, rq, hdr, has_write_perm)) {
+                blk_rq_unmap_user(bio, hdr->dxfer_len);
+                blk_put_request(rq);
+                return -EFAULT;
+        }
 
         if (hdr->iovec_count) {
                 const int size = sizeof(struct sg_iovec) * hdr->iovec_count;
@@ -306,6 +366,9 @@ static int sg_io(struct file *file, request_queue_t *q,
                 goto out;
 
         bio = rq->bio;
+        memset(sense, 0, sizeof(sense));
+        rq->sense = sense;
+        rq->sense_len = 0;
         rq->retries = 0;
 
         start_time = jiffies;
@@ -316,31 +379,9 @@ static int sg_io(struct file *file, request_queue_t *q,
          */
         blk_execute_rq(q, bd_disk, rq, 0);
 
-        /* write to all output members */
-        hdr->status = 0xff & rq->errors;
-        hdr->masked_status = status_byte(rq->errors);
-        hdr->msg_status = msg_byte(rq->errors);
-        hdr->host_status = host_byte(rq->errors);
-        hdr->driver_status = driver_byte(rq->errors);
-        hdr->info = 0;
-        if (hdr->masked_status || hdr->host_status || hdr->driver_status)
-                hdr->info |= SG_INFO_CHECK;
-        hdr->resid = rq->data_len;
         hdr->duration = ((jiffies - start_time) * 1000) / HZ;
-        hdr->sb_len_wr = 0;
-
-        if (rq->sense_len && hdr->sbp) {
-                int len = min((unsigned int) hdr->mx_sb_len, rq->sense_len);
-
-                if (!copy_to_user(hdr->sbp, rq->sense, len))
-                        hdr->sb_len_wr = len;
-        }
-
-        if (blk_rq_unmap_user(bio))
-                ret = -EFAULT;
 
-        /* may not have succeeded, but output values written to control
-         * structure (struct sg_io_hdr).  */
+        return blk_complete_sghdr_rq(rq, hdr, bio);
 out:
         blk_put_request(rq);
         return ret;
@@ -427,7 +468,7 @@ int sg_scsi_ioctl(struct file *file, struct request_queue *q,
         if (in_len && copy_from_user(buffer, sic->data + cmdlen, in_len))
                 goto error;
 
-        err = verify_command(file, rq->cmd);
+        err = verify_command(rq->cmd, file->f_mode & FMODE_WRITE);
         if (err)
                 goto error;
 
@@ -454,7 +495,7 @@ int sg_scsi_ioctl(struct file *file, struct request_queue *q,
                 rq->retries = 1;
                 break;
         default:
-                rq->timeout = BLK_DEFAULT_TIMEOUT;
+                rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
                 break;
         }
 
@@ -501,7 +542,7 @@ static int __blk_send_generic(request_queue_t *q, struct gendisk *bd_disk, int c
         rq->cmd_type = REQ_TYPE_BLOCK_PC;
         rq->data = NULL;
         rq->data_len = 0;
-        rq->timeout = BLK_DEFAULT_TIMEOUT;
+        rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
         memset(rq->cmd, 0, sizeof(rq->cmd));
         rq->cmd[0] = cmd;
         rq->cmd[4] = data;