SG: Change sg_set_page() to take length and offset argument
[safe/jmp/linux-2.6] / drivers / scsi / st.c
index da97662..98dfd6e 100644 (file)
@@ -9,7 +9,7 @@
    Steve Hirsch, Andreas Koppenh"ofer, Michael Leodolter, Eyal Lebedinsky,
    Michael Schaefer, J"org Weule, and Eric Youngdale.
 
-   Copyright 1992 - 2005 Kai Makisara
+   Copyright 1992 - 2007 Kai Makisara
    email Kai.Makisara@kolumbus.fi
 
    Some small formal changes - aeb, 950809
@@ -17,7 +17,7 @@
    Last modified: 18-JAN-1998 Richard Gooch <rgooch@atnf.csiro.au> Devfs support
  */
 
-static char *verstr = "20050830";
+static const char *verstr = "20070203";
 
 #include <linux/module.h>
 
@@ -35,9 +35,9 @@ static char *verstr = "20050830";
 #include <linux/spinlock.h>
 #include <linux/blkdev.h>
 #include <linux/moduleparam.h>
-#include <linux/devfs_fs_kernel.h>
 #include <linux/cdev.h>
 #include <linux/delay.h>
+#include <linux/mutex.h>
 
 #include <asm/uaccess.h>
 #include <asm/dma.h>
@@ -50,7 +50,6 @@ static char *verstr = "20050830";
 #include <scsi/scsi_eh.h>
 #include <scsi/scsi_host.h>
 #include <scsi/scsi_ioctl.h>
-#include <scsi/scsi_request.h>
 #include <scsi/sg.h>
 
 
@@ -87,8 +86,10 @@ static int st_nr_dev;
 static struct class *st_sysfs_class;
 
 MODULE_AUTHOR("Kai Makisara");
-MODULE_DESCRIPTION("SCSI Tape Driver");
+MODULE_DESCRIPTION("SCSI tape (st) driver");
 MODULE_LICENSE("GPL");
+MODULE_ALIAS_CHARDEV_MAJOR(SCSI_TAPE_MAJOR);
+MODULE_ALIAS_SCSI_DEVICE(TYPE_TAPE);
 
 /* Set 'perm' (4th argument) to 0 to disable module_param's definition
  * of sysfs parameters (which module_param doesn't yet support).
@@ -134,7 +135,7 @@ static struct st_dev_parm {
 #endif
 /* Bit reversed order to get same names for same minors with all
    mode counts */
-static char *st_formats[] = {
+static const char *st_formats[] = {
        "",  "r", "k", "s", "l", "t", "o", "u",
        "m", "v", "p", "x", "a", "y", "q", "z"}; 
 
@@ -188,19 +189,16 @@ static int from_buffer(struct st_buffer *, char __user *, int);
 static void move_buffer_data(struct st_buffer *, int);
 static void buf_to_sg(struct st_buffer *, unsigned int);
 
-static int st_map_user_pages(struct scatterlist *, const unsigned int, 
-                            unsigned long, size_t, int, unsigned long);
 static int sgl_map_user_pages(struct scatterlist *, const unsigned int, 
                              unsigned long, size_t, int);
 static int sgl_unmap_user_pages(struct scatterlist *, const unsigned int, int);
 
 static int st_probe(struct device *);
 static int st_remove(struct device *);
-static int st_init_command(struct scsi_cmnd *);
 
-static void do_create_driverfs_files(void);
-static void do_remove_driverfs_files(void);
-static void do_create_class_files(struct scsi_tape *, int, int);
+static int do_create_sysfs_files(void);
+static void do_remove_sysfs_files(void);
+static int do_create_class_files(struct scsi_tape *, int, int);
 
 static struct scsi_driver st_template = {
        .owner                  = THIS_MODULE,
@@ -209,7 +207,6 @@ static struct scsi_driver st_template = {
                .probe          = st_probe,
                .remove         = st_remove,
        },
-       .init_command           = st_init_command,
 };
 
 static int st_compression(struct scsi_tape *, int);
@@ -223,7 +220,7 @@ static void scsi_tape_release(struct kref *);
 
 #define to_scsi_tape(obj) container_of(obj, struct scsi_tape, kref)
 
-static DECLARE_MUTEX(st_ref_sem);
+static DEFINE_MUTEX(st_ref_mutex);
 
 \f
 #include "osst_detect.h"
@@ -240,7 +237,7 @@ static struct scsi_tape *scsi_tape_get(int dev)
 {
        struct scsi_tape *STp = NULL;
 
-       down(&st_ref_sem);
+       mutex_lock(&st_ref_mutex);
        write_lock(&st_dev_arr_lock);
 
        if (dev < st_dev_max && scsi_tapes != NULL)
@@ -262,7 +259,7 @@ out_put:
        STp = NULL;
 out:
        write_unlock(&st_dev_arr_lock);
-       up(&st_ref_sem);
+       mutex_unlock(&st_ref_mutex);
        return STp;
 }
 
@@ -270,10 +267,10 @@ static void scsi_tape_put(struct scsi_tape *STp)
 {
        struct scsi_device *sdev = STp->device;
 
-       down(&st_ref_sem);
+       mutex_lock(&st_ref_mutex);
        kref_put(&STp->kref, scsi_tape_release);
        scsi_device_put(sdev);
-       up(&st_ref_sem);
+       mutex_unlock(&st_ref_mutex);
 }
 
 struct st_reject_data {
@@ -313,12 +310,13 @@ static inline char *tape_name(struct scsi_tape *tape)
 }
 
 
-static void st_analyze_sense(struct scsi_request *SRpnt, struct st_cmdstatus *s)
+static void st_analyze_sense(struct st_request *SRpnt, struct st_cmdstatus *s)
 {
        const u8 *ucp;
-       const u8 *sense = SRpnt->sr_sense_buffer;
+       const u8 *sense = SRpnt->sense;
 
-       s->have_sense = scsi_request_normalize_sense(SRpnt, &s->sense_hdr);
+       s->have_sense = scsi_normalize_sense(SRpnt->sense,
+                               SCSI_SENSE_BUFFERSIZE, &s->sense_hdr);
        s->flags = 0;
 
        if (s->have_sense) {
@@ -345,9 +343,9 @@ static void st_analyze_sense(struct scsi_request *SRpnt, struct st_cmdstatus *s)
 
 
 /* Convert the result to success code */
-static int st_chk_result(struct scsi_tape *STp, struct scsi_request * SRpnt)
+static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt)
 {
-       int result = SRpnt->sr_result;
+       int result = SRpnt->result;
        u8 scode;
        DEB(const char *stp;)
        char *name = tape_name(STp);
@@ -366,13 +364,12 @@ static int st_chk_result(struct scsi_tape *STp, struct scsi_request * SRpnt)
 
         DEB(
         if (debugging) {
-                printk(ST_DEB_MSG "%s: Error: %x, cmd: %x %x %x %x %x %x Len: %d\n",
+                printk(ST_DEB_MSG "%s: Error: %x, cmd: %x %x %x %x %x %x\n",
                       name, result,
-                      SRpnt->sr_cmnd[0], SRpnt->sr_cmnd[1], SRpnt->sr_cmnd[2],
-                      SRpnt->sr_cmnd[3], SRpnt->sr_cmnd[4], SRpnt->sr_cmnd[5],
-                      SRpnt->sr_bufflen);
+                      SRpnt->cmd[0], SRpnt->cmd[1], SRpnt->cmd[2],
+                      SRpnt->cmd[3], SRpnt->cmd[4], SRpnt->cmd[5]);
                if (cmdstatp->have_sense)
-                       scsi_print_req_sense("st", SRpnt);
+                        __scsi_print_sense(name, SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
        } ) /* end DEB */
        if (!debugging) { /* Abnormal conditions for tape */
                if (!cmdstatp->have_sense)
@@ -386,20 +383,20 @@ static int st_chk_result(struct scsi_tape *STp, struct scsi_request * SRpnt)
                         /* scode != UNIT_ATTENTION && */
                         scode != BLANK_CHECK &&
                         scode != VOLUME_OVERFLOW &&
-                        SRpnt->sr_cmnd[0] != MODE_SENSE &&
-                        SRpnt->sr_cmnd[0] != TEST_UNIT_READY) {
-                               printk(KERN_WARNING "%s: Error with sense data: ", name);
-                               scsi_print_req_sense("st", SRpnt);
+                        SRpnt->cmd[0] != MODE_SENSE &&
+                        SRpnt->cmd[0] != TEST_UNIT_READY) {
+
+                       __scsi_print_sense(name, SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
                }
        }
 
        if (cmdstatp->fixed_format &&
            STp->cln_mode >= EXTENDED_SENSE_START) {  /* Only fixed format sense */
                if (STp->cln_sense_value)
-                       STp->cleaning_req |= ((SRpnt->sr_sense_buffer[STp->cln_mode] &
+                       STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
                                               STp->cln_sense_mask) == STp->cln_sense_value);
                else
-                       STp->cleaning_req |= ((SRpnt->sr_sense_buffer[STp->cln_mode] &
+                       STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
                                               STp->cln_sense_mask) != 0);
        }
        if (cmdstatp->have_sense &&
@@ -411,8 +408,8 @@ static int st_chk_result(struct scsi_tape *STp, struct scsi_request * SRpnt)
        if (cmdstatp->have_sense &&
            scode == RECOVERED_ERROR
 #if ST_RECOVERED_WRITE_FATAL
-           && SRpnt->sr_cmnd[0] != WRITE_6
-           && SRpnt->sr_cmnd[0] != WRITE_FILEMARKS
+           && SRpnt->cmd[0] != WRITE_6
+           && SRpnt->cmd[0] != WRITE_FILEMARKS
 #endif
            ) {
                STp->recover_count++;
@@ -420,9 +417,9 @@ static int st_chk_result(struct scsi_tape *STp, struct scsi_request * SRpnt)
 
                 DEB(
                if (debugging) {
-                       if (SRpnt->sr_cmnd[0] == READ_6)
+                       if (SRpnt->cmd[0] == READ_6)
                                stp = "read";
-                       else if (SRpnt->sr_cmnd[0] == WRITE_6)
+                       else if (SRpnt->cmd[0] == WRITE_6)
                                stp = "write";
                        else
                                stp = "ioctl";
@@ -438,28 +435,37 @@ static int st_chk_result(struct scsi_tape *STp, struct scsi_request * SRpnt)
 
 
 /* Wakeup from interrupt */
-static void st_sleep_done(struct scsi_cmnd * SCpnt)
+static void st_sleep_done(void *data, char *sense, int result, int resid)
 {
-       struct scsi_tape *STp = container_of(SCpnt->request->rq_disk->private_data,
-                                            struct scsi_tape, driver);
+       struct st_request *SRpnt = data;
+       struct scsi_tape *STp = SRpnt->stp;
 
-       (STp->buffer)->cmdstat.midlevel_result = SCpnt->result;
-       SCpnt->request->rq_status = RQ_SCSI_DONE;
+       memcpy(SRpnt->sense, sense, SCSI_SENSE_BUFFERSIZE);
+       (STp->buffer)->cmdstat.midlevel_result = SRpnt->result = result;
        DEB( STp->write_pending = 0; )
 
-       if (SCpnt->request->waiting)
-               complete(SCpnt->request->waiting);
+       if (SRpnt->waiting)
+               complete(SRpnt->waiting);
+}
+
+static struct st_request *st_allocate_request(void)
+{
+       return kzalloc(sizeof(struct st_request), GFP_KERNEL);
+}
+
+static void st_release_request(struct st_request *streq)
+{
+       kfree(streq);
 }
 
 /* Do the scsi command. Waits until command performed if do_wait is true.
    Otherwise write_behind_check() is used to check that the command
    has finished. */
-static struct scsi_request *
-st_do_scsi(struct scsi_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd,
+static struct st_request *
+st_do_scsi(struct st_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd,
           int bytes, int direction, int timeout, int retries, int do_wait)
 {
        struct completion *waiting;
-       unsigned char *bp;
 
        /* if async, make sure there's no command outstanding */
        if (!do_wait && ((STp->buffer)->last_SRpnt)) {
@@ -473,7 +479,7 @@ st_do_scsi(struct scsi_request * SRpnt, struct scsi_tape * STp, unsigned char *c
        }
 
        if (SRpnt == NULL) {
-               SRpnt = scsi_allocate_request(STp->device, GFP_ATOMIC);
+               SRpnt = st_allocate_request();
                if (SRpnt == NULL) {
                        DEBC( printk(KERN_ERR "%s: Can't get SCSI request.\n",
                                     tape_name(STp)); );
@@ -483,6 +489,7 @@ st_do_scsi(struct scsi_request * SRpnt, struct scsi_tape * STp, unsigned char *c
                                (STp->buffer)->syscall_result = (-EBUSY);
                        return NULL;
                }
+               SRpnt->stp = STp;
        }
 
        /* If async IO, set last_SRpnt. This ptr tells write_behind_check
@@ -492,32 +499,28 @@ st_do_scsi(struct scsi_request * SRpnt, struct scsi_tape * STp, unsigned char *c
 
        waiting = &STp->wait;
        init_completion(waiting);
-       SRpnt->sr_use_sg = STp->buffer->do_dio || (bytes > (STp->buffer)->frp[0].length);
-       if (SRpnt->sr_use_sg) {
-               if (!STp->buffer->do_dio)
-                       buf_to_sg(STp->buffer, bytes);
-               SRpnt->sr_use_sg = (STp->buffer)->sg_segs;
-               bp = (char *) &((STp->buffer)->sg[0]);
-       } else
-               bp = (STp->buffer)->b_data;
-       SRpnt->sr_data_direction = direction;
-       SRpnt->sr_cmd_len = 0;
-       SRpnt->sr_request->waiting = waiting;
-       SRpnt->sr_request->rq_status = RQ_SCSI_BUSY;
-       SRpnt->sr_request->rq_disk = STp->disk;
-       SRpnt->sr_request->end_io = blk_end_sync_rq;
-       STp->buffer->cmdstat.have_sense = 0;
+       SRpnt->waiting = waiting;
 
-       scsi_do_req(SRpnt, (void *) cmd, bp, bytes,
-                   st_sleep_done, timeout, retries);
+       if (!STp->buffer->do_dio)
+               buf_to_sg(STp->buffer, bytes);
 
-       if (do_wait) {
+       memcpy(SRpnt->cmd, cmd, sizeof(SRpnt->cmd));
+       STp->buffer->cmdstat.have_sense = 0;
+       STp->buffer->syscall_result = 0;
+
+       if (scsi_execute_async(STp->device, cmd, COMMAND_SIZE(cmd[0]), direction,
+                       &((STp->buffer)->sg[0]), bytes, (STp->buffer)->sg_segs,
+                              timeout, retries, SRpnt, st_sleep_done, GFP_KERNEL)) {
+               /* could not allocate the buffer or request was too large */
+               (STp->buffer)->syscall_result = (-EBUSY);
+               (STp->buffer)->last_SRpnt = NULL;
+       }
+       else if (do_wait) {
                wait_for_completion(waiting);
-               SRpnt->sr_request->waiting = NULL;
-               if (SRpnt->sr_request->rq_status != RQ_SCSI_DONE)
-                       SRpnt->sr_result |= (DRIVER_ERROR << 24);
+               SRpnt->waiting = NULL;
                (STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
        }
+
        return SRpnt;
 }
 
@@ -532,7 +535,7 @@ static int write_behind_check(struct scsi_tape * STp)
        struct st_buffer *STbuffer;
        struct st_partstat *STps;
        struct st_cmdstatus *cmdstatp;
-       struct scsi_request *SRpnt;
+       struct st_request *SRpnt;
 
        STbuffer = STp->buffer;
        if (!STbuffer->writing)
@@ -548,12 +551,10 @@ static int write_behind_check(struct scsi_tape * STp)
        wait_for_completion(&(STp->wait));
        SRpnt = STbuffer->last_SRpnt;
        STbuffer->last_SRpnt = NULL;
-       SRpnt->sr_request->waiting = NULL;
-       if (SRpnt->sr_request->rq_status != RQ_SCSI_DONE)
-               SRpnt->sr_result |= (DRIVER_ERROR << 24);
+       SRpnt->waiting = NULL;
 
        (STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
-       scsi_release_request(SRpnt);
+       st_release_request(SRpnt);
 
        STbuffer->buffer_bytes -= STbuffer->writing;
        STps = &(STp->ps[STp->partition]);
@@ -593,7 +594,7 @@ static int write_behind_check(struct scsi_tape * STp)
    it messes up the block number). */
 static int cross_eof(struct scsi_tape * STp, int forward)
 {
-       struct scsi_request *SRpnt;
+       struct st_request *SRpnt;
        unsigned char cmd[MAX_COMMAND_SIZE];
 
        cmd[0] = SPACE;
@@ -613,7 +614,7 @@ static int cross_eof(struct scsi_tape * STp, int forward)
        if (!SRpnt)
                return (STp->buffer)->syscall_result;
 
-       scsi_release_request(SRpnt);
+       st_release_request(SRpnt);
        SRpnt = NULL;
 
        if ((STp->buffer)->cmdstat.midlevel_result != 0)
@@ -630,7 +631,7 @@ static int flush_write_buffer(struct scsi_tape * STp)
        int offset, transfer, blks;
        int result;
        unsigned char cmd[MAX_COMMAND_SIZE];
-       struct scsi_request *SRpnt;
+       struct st_request *SRpnt;
        struct st_partstat *STps;
 
        result = write_behind_check(STp);
@@ -688,7 +689,7 @@ static int flush_write_buffer(struct scsi_tape * STp)
                        STp->dirty = 0;
                        (STp->buffer)->buffer_bytes = 0;
                }
-               scsi_release_request(SRpnt);
+               st_release_request(SRpnt);
                SRpnt = NULL;
        }
        return result;
@@ -785,7 +786,7 @@ static int set_mode_densblk(struct scsi_tape * STp, struct st_modedef * STm)
 }
 
 
-/* Lock or unlock the drive door. Don't use when scsi_request allocated. */
+/* Lock or unlock the drive door. Don't use when st_request allocated. */
 static int do_door_lock(struct scsi_tape * STp, int do_lock)
 {
        int retval, cmd;
@@ -844,7 +845,7 @@ static int test_ready(struct scsi_tape *STp, int do_wait)
        int attentions, waits, max_wait, scode;
        int retval = CHKRES_READY, new_session = 0;
        unsigned char cmd[MAX_COMMAND_SIZE];
-       struct scsi_request *SRpnt = NULL;
+       struct st_request *SRpnt = NULL;
        struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 
        max_wait = do_wait ? ST_BLOCK_SECONDS : 0;
@@ -903,7 +904,7 @@ static int test_ready(struct scsi_tape *STp, int do_wait)
        }
 
        if (SRpnt != NULL)
-               scsi_release_request(SRpnt);
+               st_release_request(SRpnt);
        return retval;
 }
 
@@ -918,11 +919,11 @@ static int check_tape(struct scsi_tape *STp, struct file *filp)
        int i, retval, new_session = 0, do_wait;
        unsigned char cmd[MAX_COMMAND_SIZE], saved_cleaning;
        unsigned short st_flags = filp->f_flags;
-       struct scsi_request *SRpnt = NULL;
+       struct st_request *SRpnt = NULL;
        struct st_modedef *STm;
        struct st_partstat *STps;
        char *name = tape_name(STp);
-       struct inode *inode = filp->f_dentry->d_inode;
+       struct inode *inode = filp->f_path.dentry->d_inode;
        int mode = TAPE_MODE(inode);
 
        STp->ready = ST_READY;
@@ -993,13 +994,13 @@ static int check_tape(struct scsi_tape *STp, struct file *filp)
                        goto err_out;
                }
 
-               if (!SRpnt->sr_result && !STp->buffer->cmdstat.have_sense) {
+               if (!SRpnt->result && !STp->buffer->cmdstat.have_sense) {
                        STp->max_block = ((STp->buffer)->b_data[1] << 16) |
                            ((STp->buffer)->b_data[2] << 8) | (STp->buffer)->b_data[3];
                        STp->min_block = ((STp->buffer)->b_data[4] << 8) |
                            (STp->buffer)->b_data[5];
                        if ( DEB( debugging || ) !STp->inited)
-                               printk(KERN_WARNING
+                               printk(KERN_INFO
                                        "%s: Block limits %d - %d bytes.\n", name,
                                        STp->min_block, STp->max_block);
                } else {
@@ -1045,7 +1046,7 @@ static int check_tape(struct scsi_tape *STp, struct file *filp)
                }
                STp->drv_write_prot = ((STp->buffer)->b_data[2] & 0x80) != 0;
        }
-       scsi_release_request(SRpnt);
+       st_release_request(SRpnt);
        SRpnt = NULL;
         STp->inited = 1;
 
@@ -1168,6 +1169,7 @@ static int st_open(struct inode *inode, struct file *filp)
                STps = &(STp->ps[i]);
                STps->rw = ST_IDLE;
        }
+       STp->try_dio_now = STp->try_dio;
        STp->recover_count = 0;
        DEB( STp->nbr_waits = STp->nbr_finished = 0;
             STp->nbr_requests = STp->nbr_dio = STp->nbr_pages = STp->nbr_combinable = 0; )
@@ -1177,7 +1179,10 @@ static int st_open(struct inode *inode, struct file *filp)
                goto err_out;
        if ((filp->f_flags & O_NONBLOCK) == 0 &&
            retval != CHKRES_READY) {
-               retval = (-EIO);
+               if (STp->ready == NO_TAPE)
+                       retval = (-ENOMEDIUM);
+               else
+                       retval = (-EIO);
                goto err_out;
        }
        return 0;
@@ -1192,11 +1197,11 @@ static int st_open(struct inode *inode, struct file *filp)
 \f
 
 /* Flush the tape buffer before close */
-static int st_flush(struct file *filp)
+static int st_flush(struct file *filp, fl_owner_t id)
 {
        int result = 0, result2;
        unsigned char cmd[MAX_COMMAND_SIZE];
-       struct scsi_request *SRpnt;
+       struct st_request *SRpnt;
        struct scsi_tape *STp = filp->private_data;
        struct st_modedef *STm = &(STp->modes[STp->current_mode]);
        struct st_partstat *STps = &(STp->ps[STp->partition]);
@@ -1221,7 +1226,7 @@ static int st_flush(struct file *filp)
        }
 
        DEBC( if (STp->nbr_requests)
-               printk(KERN_WARNING "%s: Number of r/w requests %d, dio used in %d, pages %d (%d).\n",
+               printk(KERN_DEBUG "%s: Number of r/w requests %d, dio used in %d, pages %d (%d).\n",
                       name, STp->nbr_requests, STp->nbr_dio, STp->nbr_pages, STp->nbr_combinable));
 
        if (STps->rw == ST_WRITING && !STp->pos_unknown) {
@@ -1249,7 +1254,7 @@ static int st_flush(struct file *filp)
                      cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
                     (!cmdstatp->remainder_valid || cmdstatp->uremainder64 == 0))) {
                        /* Write successful at EOM */
-                       scsi_release_request(SRpnt);
+                       st_release_request(SRpnt);
                        SRpnt = NULL;
                        if (STps->drv_file >= 0)
                                STps->drv_file++;
@@ -1259,7 +1264,7 @@ static int st_flush(struct file *filp)
                        STps->eof = ST_FM;
                }
                else { /* Write error */
-                       scsi_release_request(SRpnt);
+                       st_release_request(SRpnt);
                        SRpnt = NULL;
                        printk(KERN_ERR "%s: Error on write filemark.\n", name);
                        if (result == 0)
@@ -1397,14 +1402,14 @@ static int setup_buffering(struct scsi_tape *STp, const char __user *buf,
        struct st_buffer *STbp = STp->buffer;
 
        if (is_read)
-               i = STp->try_dio && try_rdio;
+               i = STp->try_dio_now && try_rdio;
        else
-               i = STp->try_dio && try_wdio;
+               i = STp->try_dio_now && try_wdio;
+
        if (i && ((unsigned long)buf & queue_dma_alignment(
                                        STp->device->request_queue)) == 0) {
-               i = st_map_user_pages(&(STbp->sg[0]), STbp->use_sg,
-                                     (unsigned long)buf, count, (is_read ? READ : WRITE),
-                                     STp->max_pfn);
+               i = sgl_map_user_pages(&(STbp->sg[0]), STbp->use_sg,
+                                     (unsigned long)buf, count, (is_read ? READ : WRITE));
                if (i > 0) {
                        STbp->do_dio = i;
                        STbp->buffer_bytes = 0;   /* can be used as transfer counter */
@@ -1449,14 +1454,15 @@ static int setup_buffering(struct scsi_tape *STp, const char __user *buf,
 
 
 /* Can be called more than once after each setup_buffer() */
-static void release_buffering(struct scsi_tape *STp)
+static void release_buffering(struct scsi_tape *STp, int is_read)
 {
        struct st_buffer *STbp;
 
        STbp = STp->buffer;
        if (STbp->do_dio) {
-               sgl_unmap_user_pages(&(STbp->sg[0]), STbp->do_dio, 0);
+               sgl_unmap_user_pages(&(STbp->sg[0]), STbp->do_dio, is_read);
                STbp->do_dio = 0;
+               STbp->sg_segs = 0;
        }
 }
 
@@ -1472,14 +1478,14 @@ st_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
        int async_write;
        unsigned char cmd[MAX_COMMAND_SIZE];
        const char __user *b_point;
-       struct scsi_request *SRpnt = NULL;
+       struct st_request *SRpnt = NULL;
        struct scsi_tape *STp = filp->private_data;
        struct st_modedef *STm;
        struct st_partstat *STps;
        struct st_buffer *STbp;
        char *name = tape_name(STp);
 
-       if (down_interruptible(&STp->lock))
+       if (mutex_lock_interruptible(&STp->lock))
                return -ERESTARTSYS;
 
        retval = rw_checks(STp, filp, count);
@@ -1595,7 +1601,7 @@ st_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
                        STm->do_async_writes && STps->eof < ST_EOM_OK;
 
                if (STp->block_size != 0 && STm->do_buffer_writes &&
-                   !(STp->try_dio && try_wdio) && STps->eof < ST_EOM_OK &&
+                   !(STp->try_dio_now && try_wdio) && STps->eof < ST_EOM_OK &&
                    STbp->buffer_bytes < STbp->buffer_size) {
                        STp->dirty = 1;
                        /* Don't write a buffer that is not full enough. */
@@ -1624,7 +1630,7 @@ st_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
                        retval = STbp->syscall_result;
                        goto out;
                }
-               if (async_write) {
+               if (async_write && !STbp->syscall_result) {
                        STbp->writing = transfer;
                        STp->dirty = !(STbp->writing ==
                                       STbp->buffer_bytes);
@@ -1698,7 +1704,7 @@ st_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
                        } else {
                                count += do_count;
                                STps->drv_block = (-1);         /* Too cautious? */
-                               retval = (-EIO);
+                               retval = STbp->syscall_result;
                        }
 
                }
@@ -1728,9 +1734,9 @@ st_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 
  out:
        if (SRpnt != NULL)
-               scsi_release_request(SRpnt);
-       release_buffering(STp);
-       up(&STp->lock);
+               st_release_request(SRpnt);
+       release_buffering(STp, 0);
+       mutex_unlock(&STp->lock);
 
        return retval;
 }
@@ -1742,11 +1748,11 @@ st_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
    Does release user buffer mapping if it is set.
 */
 static long read_tape(struct scsi_tape *STp, long count,
-                     struct scsi_request ** aSRpnt)
+                     struct st_request ** aSRpnt)
 {
        int transfer, blks, bytes;
        unsigned char cmd[MAX_COMMAND_SIZE];
-       struct scsi_request *SRpnt;
+       struct st_request *SRpnt;
        struct st_modedef *STm;
        struct st_partstat *STps;
        struct st_buffer *STbp;
@@ -1765,7 +1771,7 @@ static long read_tape(struct scsi_tape *STp, long count,
        if (STp->block_size == 0)
                blks = bytes = count;
        else {
-               if (!(STp->try_dio && try_rdio) && STm->do_read_ahead) {
+               if (!(STp->try_dio_now && try_rdio) && STm->do_read_ahead) {
                        blks = (STp->buffer)->buffer_blocks;
                        bytes = blks * STp->block_size;
                } else {
@@ -1787,7 +1793,7 @@ static long read_tape(struct scsi_tape *STp, long count,
        SRpnt = *aSRpnt;
        SRpnt = st_do_scsi(SRpnt, STp, cmd, bytes, DMA_FROM_DEVICE,
                           STp->device->timeout, MAX_RETRIES, 1);
-       release_buffering(STp);
+       release_buffering(STp, 1);
        *aSRpnt = SRpnt;
        if (!SRpnt)
                return STbp->syscall_result;
@@ -1802,10 +1808,10 @@ static long read_tape(struct scsi_tape *STp, long count,
                retval = 1;
                DEBC(printk(ST_DEB_MSG "%s: Sense: %2x %2x %2x %2x %2x %2x %2x %2x\n",
                             name,
-                            SRpnt->sr_sense_buffer[0], SRpnt->sr_sense_buffer[1],
-                            SRpnt->sr_sense_buffer[2], SRpnt->sr_sense_buffer[3],
-                            SRpnt->sr_sense_buffer[4], SRpnt->sr_sense_buffer[5],
-                            SRpnt->sr_sense_buffer[6], SRpnt->sr_sense_buffer[7]));
+                            SRpnt->sense[0], SRpnt->sense[1],
+                            SRpnt->sense[2], SRpnt->sense[3],
+                            SRpnt->sense[4], SRpnt->sense[5],
+                            SRpnt->sense[6], SRpnt->sense[7]));
                if (cmdstatp->have_sense) {
 
                        if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
@@ -1835,7 +1841,7 @@ static long read_tape(struct scsi_tape *STp, long count,
                                                }
                                                STbp->buffer_bytes = bytes - transfer;
                                        } else {
-                                               scsi_release_request(SRpnt);
+                                               st_release_request(SRpnt);
                                                SRpnt = *aSRpnt = NULL;
                                                if (transfer == blks) { /* We did not get anything, error */
                                                        printk(KERN_NOTICE "%s: Incorrect block size.\n", name);
@@ -1929,14 +1935,14 @@ st_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
        ssize_t retval = 0;
        ssize_t i, transfer;
        int special, do_dio = 0;
-       struct scsi_request *SRpnt = NULL;
+       struct st_request *SRpnt = NULL;
        struct scsi_tape *STp = filp->private_data;
        struct st_modedef *STm;
        struct st_partstat *STps;
        struct st_buffer *STbp = STp->buffer;
        DEB( char *name = tape_name(STp); )
 
-       if (down_interruptible(&STp->lock))
+       if (mutex_lock_interruptible(&STp->lock))
                return -ERESTARTSYS;
 
        retval = rw_checks(STp, filp, count);
@@ -1944,10 +1950,12 @@ st_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
                goto out;
 
        STm = &(STp->modes[STp->current_mode]);
-       if (!(STm->do_read_ahead) && STp->block_size != 0 &&
-           (count % STp->block_size) != 0) {
-               retval = (-EINVAL);     /* Read must be integral number of blocks */
-               goto out;
+       if (STp->block_size != 0 && (count % STp->block_size) != 0) {
+               if (!STm->do_read_ahead) {
+                       retval = (-EINVAL);     /* Read must be integral number of blocks */
+                       goto out;
+               }
+               STp->try_dio_now = 0;  /* Direct i/o can't handle split blocks */
        }
 
        STps = &(STp->ps[STp->partition]);
@@ -2054,14 +2062,14 @@ st_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 
  out:
        if (SRpnt != NULL) {
-               scsi_release_request(SRpnt);
+               st_release_request(SRpnt);
                SRpnt = NULL;
        }
        if (do_dio) {
-               release_buffering(STp);
+               release_buffering(STp, 1);
                STbp->buffer_bytes = 0;
        }
-       up(&STp->lock);
+       mutex_unlock(&STp->lock);
 
        return retval;
 }
@@ -2284,7 +2292,7 @@ static int st_set_options(struct scsi_tape *STp, long options)
 static int read_mode_page(struct scsi_tape *STp, int page, int omit_block_descs)
 {
        unsigned char cmd[MAX_COMMAND_SIZE];
-       struct scsi_request *SRpnt = NULL;
+       struct st_request *SRpnt = NULL;
 
        memset(cmd, 0, MAX_COMMAND_SIZE);
        cmd[0] = MODE_SENSE;
@@ -2298,7 +2306,7 @@ static int read_mode_page(struct scsi_tape *STp, int page, int omit_block_descs)
        if (SRpnt == NULL)
                return (STp->buffer)->syscall_result;
 
-       scsi_release_request(SRpnt);
+       st_release_request(SRpnt);
 
        return (STp->buffer)->syscall_result;
 }
@@ -2310,7 +2318,7 @@ static int write_mode_page(struct scsi_tape *STp, int page, int slow)
 {
        int pgo;
        unsigned char cmd[MAX_COMMAND_SIZE];
-       struct scsi_request *SRpnt = NULL;
+       struct st_request *SRpnt = NULL;
 
        memset(cmd, 0, MAX_COMMAND_SIZE);
        cmd[0] = MODE_SELECT;
@@ -2329,7 +2337,7 @@ static int write_mode_page(struct scsi_tape *STp, int page, int slow)
        if (SRpnt == NULL)
                return (STp->buffer)->syscall_result;
 
-       scsi_release_request(SRpnt);
+       st_release_request(SRpnt);
 
        return (STp->buffer)->syscall_result;
 }
@@ -2412,7 +2420,7 @@ static int do_load_unload(struct scsi_tape *STp, struct file *filp, int load_cod
        DEB( char *name = tape_name(STp); )
        unsigned char cmd[MAX_COMMAND_SIZE];
        struct st_partstat *STps;
-       struct scsi_request *SRpnt;
+       struct st_request *SRpnt;
 
        if (STp->ready != ST_READY && !load_code) {
                if (STp->ready == ST_NO_TAPE)
@@ -2455,7 +2463,7 @@ static int do_load_unload(struct scsi_tape *STp, struct file *filp, int load_cod
                return (STp->buffer)->syscall_result;
 
        retval = (STp->buffer)->syscall_result;
-       scsi_release_request(SRpnt);
+       st_release_request(SRpnt);
 
        if (!retval) {  /* SCSI command successful */
 
@@ -2503,7 +2511,7 @@ static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned lon
        int ioctl_result;
        int chg_eof = 1;
        unsigned char cmd[MAX_COMMAND_SIZE];
-       struct scsi_request *SRpnt;
+       struct st_request *SRpnt;
        struct st_partstat *STps;
        int fileno, blkno, at_sm, undone;
        int datalen = 0, direction = DMA_NONE;
@@ -2757,7 +2765,7 @@ static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned lon
        ioctl_result = (STp->buffer)->syscall_result;
 
        if (!ioctl_result) {    /* SCSI command successful */
-               scsi_release_request(SRpnt);
+               st_release_request(SRpnt);
                SRpnt = NULL;
                STps->drv_block = blkno;
                STps->drv_file = fileno;
@@ -2812,15 +2820,18 @@ static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned lon
 
                if (cmd_in == MTWEOF &&
                    cmdstatp->have_sense &&
-                   (cmdstatp->flags & SENSE_EOM) &&
-                   (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
-                    cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
-                   undone == 0) {
-                       ioctl_result = 0;       /* EOF written succesfully at EOM */
-                       if (fileno >= 0)
-                               fileno++;
+                   (cmdstatp->flags & SENSE_EOM)) {
+                       if (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
+                           cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) {
+                               ioctl_result = 0;       /* EOF(s) written successfully at EOM */
+                               STps->eof = ST_NOEOF;
+                       } else {  /* Writing EOF(s) failed */
+                               if (fileno >= 0)
+                                       fileno -= undone;
+                               if (undone < arg)
+                                       STps->eof = ST_NOEOF;
+                       }
                        STps->drv_file = fileno;
-                       STps->eof = ST_NOEOF;
                } else if ((cmd_in == MTFSF) || (cmd_in == MTFSFM)) {
                        if (fileno >= 0)
                                STps->drv_file = fileno - undone;
@@ -2872,7 +2883,7 @@ static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned lon
                                /* Try the other possible state of Page Format if not
                                   already tried */
                                STp->use_pf = !STp->use_pf | PF_TESTED;
-                               scsi_release_request(SRpnt);
+                               st_release_request(SRpnt);
                                SRpnt = NULL;
                                return st_int_ioctl(STp, cmd_in, arg);
                        }
@@ -2882,7 +2893,7 @@ static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned lon
                if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
                        STps->eof = ST_EOD;
 
-               scsi_release_request(SRpnt);
+               st_release_request(SRpnt);
                SRpnt = NULL;
        }
 
@@ -2898,7 +2909,7 @@ static int get_location(struct scsi_tape *STp, unsigned int *block, int *partiti
 {
        int result;
        unsigned char scmd[MAX_COMMAND_SIZE];
-       struct scsi_request *SRpnt;
+       struct st_request *SRpnt;
        DEB( char *name = tape_name(STp); )
 
        if (STp->ready != ST_READY)
@@ -2944,7 +2955,7 @@ static int get_location(struct scsi_tape *STp, unsigned int *block, int *partiti
                 DEBC(printk(ST_DEB_MSG "%s: Got tape pos. blk %d part %d.\n", name,
                             *block, *partition));
        }
-       scsi_release_request(SRpnt);
+       st_release_request(SRpnt);
        SRpnt = NULL;
 
        return result;
@@ -2961,7 +2972,7 @@ static int set_location(struct scsi_tape *STp, unsigned int block, int partition
        unsigned int blk;
        int timeout;
        unsigned char scmd[MAX_COMMAND_SIZE];
-       struct scsi_request *SRpnt;
+       struct st_request *SRpnt;
        DEB( char *name = tape_name(STp); )
 
        if (STp->ready != ST_READY)
@@ -3047,7 +3058,7 @@ static int set_location(struct scsi_tape *STp, unsigned int block, int partition
                result = 0;
        }
 
-       scsi_release_request(SRpnt);
+       st_release_request(SRpnt);
        SRpnt = NULL;
 
        return result;
@@ -3215,7 +3226,7 @@ static int st_ioctl(struct inode *inode, struct file *file,
        char *name = tape_name(STp);
        void __user *p = (void __user *)arg;
 
-       if (down_interruptible(&STp->lock))
+       if (mutex_lock_interruptible(&STp->lock))
                return -ERESTARTSYS;
 
         DEB(
@@ -3526,7 +3537,7 @@ static int st_ioctl(struct inode *inode, struct file *file,
                        retval = (-EFAULT);
                goto out;
        }
-       up(&STp->lock);
+       mutex_unlock(&STp->lock);
        switch (cmd_in) {
                case SCSI_IOCTL_GET_IDLUN:
                case SCSI_IOCTL_GET_BUS_NUMBER:
@@ -3538,7 +3549,8 @@ static int st_ioctl(struct inode *inode, struct file *file,
                            !capable(CAP_SYS_RAWIO))
                                i = -EPERM;
                        else
-                               i = scsi_cmd_ioctl(file, STp->disk, cmd_in, p);
+                               i = scsi_cmd_ioctl(file, STp->disk->queue,
+                                                  STp->disk, cmd_in, p);
                        if (i != -ENOTTY)
                                return i;
                        break;
@@ -3551,7 +3563,7 @@ static int st_ioctl(struct inode *inode, struct file *file,
        return retval;
 
  out:
-       up(&STp->lock);
+       mutex_unlock(&STp->lock);
        return retval;
 }
 
@@ -3577,7 +3589,7 @@ static long st_compat_ioctl(struct file *file, unsigned int cmd, unsigned long a
 static struct st_buffer *
  new_tape_buffer(int from_initialization, int need_dma, int max_sg)
 {
-       int i, got = 0, segs = 0;
+       int i, got = 0;
        gfp_t priority;
        struct st_buffer *tb;
 
@@ -3588,19 +3600,15 @@ static struct st_buffer *
 
        i = sizeof(struct st_buffer) + (max_sg - 1) * sizeof(struct scatterlist) +
                max_sg * sizeof(struct st_buf_fragment);
-       tb = kmalloc(i, priority);
+       tb = kzalloc(i, priority);
        if (!tb) {
                printk(KERN_NOTICE "st: Can't allocate new tape buffer.\n");
                return NULL;
        }
-       memset(tb, 0, i);
-       tb->frp_segs = tb->orig_frp_segs = segs;
+       tb->frp_segs = tb->orig_frp_segs = 0;
        tb->use_sg = max_sg;
-       if (segs > 0)
-               tb->b_data = page_address(tb->sg[0].page);
        tb->frp = (struct st_buf_fragment *)(&(tb->sg[0]) + max_sg);
 
-       tb->in_use = 1;
        tb->dma = need_dma;
        tb->buffer_size = got;
 
@@ -3628,7 +3636,7 @@ static int enlarge_buffer(struct st_buffer * STbuffer, int new_size, int need_dm
        priority = GFP_KERNEL | __GFP_NOWARN;
        if (need_dma)
                priority |= GFP_DMA;
-       for (b_size = PAGE_SIZE, order=0;
+       for (b_size = PAGE_SIZE, order=0; order <= 6 &&
             b_size < new_size - STbuffer->buffer_size;
             order++, b_size *= 2)
                ;  /* empty */
@@ -3670,6 +3678,7 @@ static void normalize_buffer(struct st_buffer * STbuffer)
        }
        STbuffer->frp_segs = STbuffer->orig_frp_segs;
        STbuffer->frp_sg_current = 0;
+       STbuffer->sg_segs = 0;
 }
 
 
@@ -3788,13 +3797,11 @@ static void buf_to_sg(struct st_buffer *STbp, unsigned int length)
        sg = &(STbp->sg[0]);
        frp = STbp->frp;
        for (i=count=0; count < length; i++) {
-               sg[i].page = frp[i].page;
                if (length - count > frp[i].length)
-                       sg[i].length = frp[i].length;
+                       sg_set_page(&sg[i], frp[i].page, frp[i].length, 0);
                else
-                       sg[i].length = length - count;
+                       sg_set_page(&sg[i], frp[i].page, length - count, 0);
                count += sg[i].length;
-               sg[i].offset = 0;
        }
        STbp->sg_segs = i;
        STbp->frp_sg_current = length;
@@ -3839,7 +3846,7 @@ static int __init st_setup(char *str)
                                        break;
                                }
                        }
-                       if (i >= sizeof(parms) / sizeof(struct st_dev_parm))
+                       if (i >= ARRAY_SIZE(parms))
                                 printk(KERN_WARNING "st: invalid parameter in '%s'\n",
                                        stp);
                        stp = strchr(stp, ',');
@@ -3857,7 +3864,7 @@ __setup("st=", st_setup);
 
 #endif
 
-static struct file_operations st_fops =
+static const struct file_operations st_fops =
 {
        .owner =        THIS_MODULE,
        .read =         st_read,
@@ -3882,19 +3889,17 @@ static int st_probe(struct device *dev)
        struct st_buffer *buffer;
        int i, j, mode, dev_num, error;
        char *stp;
-       u64 bounce_limit;
 
        if (SDp->type != TYPE_TAPE)
                return -ENODEV;
        if ((stp = st_incompatible(SDp))) {
-               printk(KERN_INFO
-                      "st: Found incompatible tape at scsi%d, channel %d, id %d, lun %d\n",
-                      SDp->host->host_no, SDp->channel, SDp->id, SDp->lun);
+               sdev_printk(KERN_INFO, SDp, "Found incompatible tape\n");
                printk(KERN_INFO "st: The suggested driver is %s.\n", stp);
                return -ENODEV;
        }
 
-       i = SDp->host->sg_tablesize;
+       i = min(SDp->request_queue->max_hw_segments,
+               SDp->request_queue->max_phys_segments);
        if (st_max_sg_segs < i)
                i = st_max_sg_segs;
        buffer = new_tape_buffer(1, (SDp->host)->unchecked_isa_dma, i);
@@ -3925,14 +3930,13 @@ static int st_probe(struct device *dev)
                        goto out_put_disk;
                }
 
-               tmp_da = kmalloc(tmp_dev_max * sizeof(struct scsi_tape *), GFP_ATOMIC);
+               tmp_da = kzalloc(tmp_dev_max * sizeof(struct scsi_tape *), GFP_ATOMIC);
                if (tmp_da == NULL) {
                        write_unlock(&st_dev_arr_lock);
                        printk(KERN_ERR "st: Can't extend device array.\n");
                        goto out_put_disk;
                }
 
-               memset(tmp_da, 0, tmp_dev_max * sizeof(struct scsi_tape *));
                if (scsi_tapes != NULL) {
                        memcpy(tmp_da, scsi_tapes,
                               st_dev_max * sizeof(struct scsi_tape *));
@@ -3949,13 +3953,12 @@ static int st_probe(struct device *dev)
        if (i >= st_dev_max)
                panic("scsi_devices corrupt (st)");
 
-       tpnt = kmalloc(sizeof(struct scsi_tape), GFP_ATOMIC);
+       tpnt = kzalloc(sizeof(struct scsi_tape), GFP_ATOMIC);
        if (tpnt == NULL) {
                write_unlock(&st_dev_arr_lock);
                printk(KERN_ERR "st: Can't allocate device descriptor.\n");
                goto out_put_disk;
        }
-       memset(tpnt, 0, sizeof(struct scsi_tape));
        kref_init(&tpnt->kref);
        tpnt->disk = disk;
        sprintf(disk->disk_name, "st%d", i);
@@ -3996,11 +3999,6 @@ static int st_probe(struct device *dev)
        tpnt->long_timeout = ST_LONG_TIMEOUT;
        tpnt->try_dio = try_direct_io && !SDp->host->unchecked_isa_dma;
 
-       bounce_limit = scsi_calculate_bounce_limit(SDp->host) >> PAGE_SHIFT;
-       if (bounce_limit > ULONG_MAX)
-               bounce_limit = ULONG_MAX;
-       tpnt->max_pfn = bounce_limit;
-
        for (i = 0; i < ST_NBR_MODES; i++) {
                STm = &(tpnt->modes[i]);
                STm->defined = 0;
@@ -4029,7 +4027,7 @@ static int st_probe(struct device *dev)
 
        tpnt->density_changed = tpnt->compression_changed =
            tpnt->blksize_changed = 0;
-       init_MUTEX(&tpnt->lock);
+       mutex_init(&tpnt->lock);
 
        st_nr_dev++;
        write_unlock(&st_dev_arr_lock);
@@ -4059,30 +4057,16 @@ static int st_probe(struct device *dev)
                        STm->cdevs[j] = cdev;
 
                }
-               do_create_class_files(tpnt, dev_num, mode);
+               error = do_create_class_files(tpnt, dev_num, mode);
+               if (error)
+                       goto out_free_tape;
        }
 
-       for (mode = 0; mode < ST_NBR_MODES; ++mode) {
-               /* Make sure that the minor numbers corresponding to the four
-                  first modes always get the same names */
-               i = mode << (4 - ST_NBR_MODE_BITS);
-               /*  Rewind entry  */
-               devfs_mk_cdev(MKDEV(SCSI_TAPE_MAJOR, TAPE_MINOR(dev_num, mode, 0)),
-                             S_IFCHR | S_IRUGO | S_IWUGO,
-                             "%s/mt%s", SDp->devfs_name, st_formats[i]);
-               /*  No-rewind entry  */
-               devfs_mk_cdev(MKDEV(SCSI_TAPE_MAJOR, TAPE_MINOR(dev_num, mode, 1)),
-                             S_IFCHR | S_IRUGO | S_IWUGO,
-                             "%s/mt%sn", SDp->devfs_name, st_formats[i]);
-       }
-       disk->number = devfs_register_tape(SDp->devfs_name);
-
-       printk(KERN_WARNING
-       "Attached scsi tape %s at scsi%d, channel %d, id %d, lun %d\n",
-              tape_name(tpnt), SDp->host->host_no, SDp->channel, SDp->id, SDp->lun);
-       printk(KERN_WARNING "%s: try direct i/o: %s (alignment %d B), max page reachable by HBA %lu\n",
-              tape_name(tpnt), tpnt->try_dio ? "yes" : "no",
-              queue_dma_alignment(SDp->request_queue) + 1, tpnt->max_pfn);
+       sdev_printk(KERN_NOTICE, SDp,
+                   "Attached scsi tape %s\n", tape_name(tpnt));
+       sdev_printk(KERN_INFO, SDp, "%s: try direct i/o: %s (alignment %d B)\n",
+                   tape_name(tpnt), tpnt->try_dio ? "yes" : "no",
+                   queue_dma_alignment(SDp->request_queue) + 1);
 
        return 0;
 
@@ -4110,8 +4094,7 @@ out_free_tape:
        write_unlock(&st_dev_arr_lock);
 out_put_disk:
        put_disk(disk);
-       if (tpnt)
-               kfree(tpnt);
+       kfree(tpnt);
 out_buffer_free:
        kfree(buffer);
 out:
@@ -4132,13 +4115,9 @@ static int st_remove(struct device *dev)
                        scsi_tapes[i] = NULL;
                        st_nr_dev--;
                        write_unlock(&st_dev_arr_lock);
-                       devfs_unregister_tape(tpnt->disk->number);
                        sysfs_remove_link(&tpnt->device->sdev_gendev.kobj,
                                          "tape");
                        for (mode = 0; mode < ST_NBR_MODES; ++mode) {
-                               j = mode << (4 - ST_NBR_MODE_BITS);
-                               devfs_remove("%s/mt%s", SDp->devfs_name, st_formats[j]);
-                               devfs_remove("%s/mt%sn", SDp->devfs_name, st_formats[j]);
                                for (j=0; j < 2; j++) {
                                        class_device_destroy(st_sysfs_class,
                                                             MKDEV(SCSI_TAPE_MAJOR,
@@ -4148,9 +4127,9 @@ static int st_remove(struct device *dev)
                                }
                        }
 
-                       down(&st_ref_sem);
+                       mutex_lock(&st_ref_mutex);
                        kref_put(&tpnt->kref, scsi_tape_release);
-                       up(&st_ref_sem);
+                       mutex_unlock(&st_ref_mutex);
                        return 0;
                }
        }
@@ -4163,7 +4142,7 @@ static int st_remove(struct device *dev)
  *      scsi_tape_release - Called to free the Scsi_Tape structure
  *      @kref: pointer to embedded kref
  *
- *      st_ref_sem must be held entering this routine.  Because it is
+ *      st_ref_mutex must be held entering this routine.  Because it is
  *      called on last put, you should always use the scsi_tape_get()
  *      scsi_tape_put() helpers which manipulate the semaphore directly
  *      and never do a direct kref_put().
@@ -4187,75 +4166,52 @@ static void scsi_tape_release(struct kref *kref)
        return;
 }
 
-static void st_intr(struct scsi_cmnd *SCpnt)
-{
-       scsi_io_completion(SCpnt, (SCpnt->result ? 0: SCpnt->bufflen), 1);
-}
-
-/*
- * st_init_command: only called via the scsi_cmd_ioctl (block SG_IO)
- * interface for REQ_BLOCK_PC commands.
- */
-static int st_init_command(struct scsi_cmnd *SCpnt)
-{
-       struct request *rq;
-
-       if (!(SCpnt->request->flags & REQ_BLOCK_PC))
-               return 0;
-
-       rq = SCpnt->request;
-       if (sizeof(rq->cmd) > sizeof(SCpnt->cmnd))
-               return 0;
-
-       memcpy(SCpnt->cmnd, rq->cmd, sizeof(SCpnt->cmnd));
-       SCpnt->cmd_len = rq->cmd_len;
-
-       if (rq_data_dir(rq) == WRITE)
-               SCpnt->sc_data_direction = DMA_TO_DEVICE;
-       else if (rq->data_len)
-               SCpnt->sc_data_direction = DMA_FROM_DEVICE;
-       else
-               SCpnt->sc_data_direction = DMA_NONE;
-
-       SCpnt->timeout_per_command = rq->timeout;
-       SCpnt->transfersize = rq->data_len;
-       SCpnt->done = st_intr;
-       return 1;
-}
-
 static int __init init_st(void)
 {
+       int err;
+
        validate_options();
 
-       printk(KERN_INFO
-               "st: Version %s, fixed bufsize %d, s/g segs %d\n",
+       printk(KERN_INFO "st: Version %s, fixed bufsize %d, s/g segs %d\n",
                verstr, st_fixed_buffer_size, st_max_sg_segs);
 
        st_sysfs_class = class_create(THIS_MODULE, "scsi_tape");
        if (IS_ERR(st_sysfs_class)) {
-               st_sysfs_class = NULL;
                printk(KERN_ERR "Unable create sysfs class for SCSI tapes\n");
-               return 1;
+               return PTR_ERR(st_sysfs_class);
        }
 
-       if (!register_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
-                                   ST_MAX_TAPE_ENTRIES, "st")) {
-               if (scsi_register_driver(&st_template.gendrv) == 0) {
-                       do_create_driverfs_files();
-                       return 0;
-               }
-               unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
-                                        ST_MAX_TAPE_ENTRIES);
+       err = register_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
+                                    ST_MAX_TAPE_ENTRIES, "st");
+       if (err) {
+               printk(KERN_ERR "Unable to get major %d for SCSI tapes\n",
+                      SCSI_TAPE_MAJOR);
+               goto err_class;
        }
-       class_destroy(st_sysfs_class);
 
-       printk(KERN_ERR "Unable to get major %d for SCSI tapes\n", SCSI_TAPE_MAJOR);
-       return 1;
+       err = scsi_register_driver(&st_template.gendrv);
+       if (err)
+               goto err_chrdev;
+
+       err = do_create_sysfs_files();
+       if (err)
+               goto err_scsidrv;
+
+       return 0;
+
+err_scsidrv:
+       scsi_unregister_driver(&st_template.gendrv);
+err_chrdev:
+       unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
+                                ST_MAX_TAPE_ENTRIES);
+err_class:
+       class_destroy(st_sysfs_class);
+       return err;
 }
 
 static void __exit exit_st(void)
 {
-       do_remove_driverfs_files();
+       do_remove_sysfs_files();
        scsi_unregister_driver(&st_template.gendrv);
        unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
                                 ST_MAX_TAPE_ENTRIES);
@@ -4293,24 +4249,43 @@ static ssize_t st_version_show(struct device_driver *ddd, char *buf)
 }
 static DRIVER_ATTR(version, S_IRUGO, st_version_show, NULL);
 
-static void do_create_driverfs_files(void)
+static int do_create_sysfs_files(void)
 {
-       struct device_driver *driverfs = &st_template.gendrv;
+       struct device_driver *sysfs = &st_template.gendrv;
+       int err;
+
+       err = driver_create_file(sysfs, &driver_attr_try_direct_io);
+       if (err)
+               return err;
+       err = driver_create_file(sysfs, &driver_attr_fixed_buffer_size);
+       if (err)
+               goto err_try_direct_io;
+       err = driver_create_file(sysfs, &driver_attr_max_sg_segs);
+       if (err)
+               goto err_attr_fixed_buf;
+       err = driver_create_file(sysfs, &driver_attr_version);
+       if (err)
+               goto err_attr_max_sg;
+
+       return 0;
 
-       driver_create_file(driverfs, &driver_attr_try_direct_io);
-       driver_create_file(driverfs, &driver_attr_fixed_buffer_size);
-       driver_create_file(driverfs, &driver_attr_max_sg_segs);
-       driver_create_file(driverfs, &driver_attr_version);
+err_attr_max_sg:
+       driver_remove_file(sysfs, &driver_attr_max_sg_segs);
+err_attr_fixed_buf:
+       driver_remove_file(sysfs, &driver_attr_fixed_buffer_size);
+err_try_direct_io:
+       driver_remove_file(sysfs, &driver_attr_try_direct_io);
+       return err;
 }
 
-static void do_remove_driverfs_files(void)
+static void do_remove_sysfs_files(void)
 {
-       struct device_driver *driverfs = &st_template.gendrv;
+       struct device_driver *sysfs = &st_template.gendrv;
 
-       driver_remove_file(driverfs, &driver_attr_version);
-       driver_remove_file(driverfs, &driver_attr_max_sg_segs);
-       driver_remove_file(driverfs, &driver_attr_fixed_buffer_size);
-       driver_remove_file(driverfs, &driver_attr_try_direct_io);
+       driver_remove_file(sysfs, &driver_attr_version);
+       driver_remove_file(sysfs, &driver_attr_max_sg_segs);
+       driver_remove_file(sysfs, &driver_attr_fixed_buffer_size);
+       driver_remove_file(sysfs, &driver_attr_try_direct_io);
 }
 
 
@@ -4361,15 +4336,12 @@ static ssize_t st_defcompression_show(struct class_device *class_dev, char *buf)
 
 CLASS_DEVICE_ATTR(default_compression, S_IRUGO, st_defcompression_show, NULL);
 
-static void do_create_class_files(struct scsi_tape *STp, int dev_num, int mode)
+static int do_create_class_files(struct scsi_tape *STp, int dev_num, int mode)
 {
        int i, rew, error;
        char name[10];
        struct class_device *st_class_member;
 
-       if (!st_sysfs_class)
-               return;
-
        for (rew=0; rew < 2; rew++) {
                /* Make sure that the minor numbers corresponding to the four
                   first modes always get the same names */
@@ -4384,18 +4356,24 @@ static void do_create_class_files(struct scsi_tape *STp, int dev_num, int mode)
                if (IS_ERR(st_class_member)) {
                        printk(KERN_WARNING "st%d: class_device_create failed\n",
                               dev_num);
+                       error = PTR_ERR(st_class_member);
                        goto out;
                }
                class_set_devdata(st_class_member, &STp->modes[mode]);
 
-               class_device_create_file(st_class_member,
-                                        &class_device_attr_defined);
-               class_device_create_file(st_class_member,
-                                        &class_device_attr_default_blksize);
-               class_device_create_file(st_class_member,
-                                        &class_device_attr_default_density);
-               class_device_create_file(st_class_member,
-                                        &class_device_attr_default_compression);
+               error = class_device_create_file(st_class_member,
+                                              &class_device_attr_defined);
+               if (error) goto out;
+               error = class_device_create_file(st_class_member,
+                                           &class_device_attr_default_blksize);
+               if (error) goto out;
+               error = class_device_create_file(st_class_member,
+                                           &class_device_attr_default_density);
+               if (error) goto out;
+               error = class_device_create_file(st_class_member,
+                                       &class_device_attr_default_compression);
+               if (error) goto out;
+
                if (mode == 0 && rew == 0) {
                        error = sysfs_create_link(&STp->device->sdev_gendev.kobj,
                                                  &st_class_member->kobj,
@@ -4404,40 +4382,16 @@ static void do_create_class_files(struct scsi_tape *STp, int dev_num, int mode)
                                printk(KERN_ERR
                                       "st%d: Can't create sysfs link from SCSI device.\n",
                                       dev_num);
+                               goto out;
                        }
                }
        }
- out:
-       return;
-}
-
 
-/* Pin down user pages and put them into a scatter gather list. Returns <= 0 if
-   - mapping of all pages not successful
-   - any page is above max_pfn
-   (i.e., either completely successful or fails)
-*/
-static int st_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages, 
-                            unsigned long uaddr, size_t count, int rw,
-                            unsigned long max_pfn)
-{
-       int i, nr_pages;
-
-       nr_pages = sgl_map_user_pages(sgl, max_pages, uaddr, count, rw);
-       if (nr_pages <= 0)
-               return nr_pages;
-
-       for (i=0; i < nr_pages; i++) {
-               if (page_to_pfn(sgl[i].page) > max_pfn)
-                       goto out_unmap;
-       }
-       return nr_pages;
-
- out_unmap:
-       sgl_unmap_user_pages(sgl, nr_pages, 0);
        return 0;
-}
 
+out:
+       return error;
+}
 
 /* The following functions may be useful for a larger audience. */
 static int sgl_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages, 
@@ -4490,15 +4444,13 @@ static int sgl_map_user_pages(struct scatterlist *sgl, const unsigned int max_pa
         }
 
        /* Populate the scatter/gather list */
-       sgl[0].page = pages[0]; 
-       sgl[0].offset = uaddr & ~PAGE_MASK;
+       sg_set_page(&sgl[0], pages[0], 0, uaddr & ~PAGE_MASK);
        if (nr_pages > 1) {
                sgl[0].length = PAGE_SIZE - sgl[0].offset;
                count -= sgl[0].length;
                for (i=1; i < nr_pages ; i++) {
-                       sgl[i].offset = 0;
-                       sgl[i].page = pages[i]; 
-                       sgl[i].length = count < PAGE_SIZE ? count : PAGE_SIZE;
+                       sg_set_page(&sgl[i], pages[i],
+                                   count < PAGE_SIZE ? count : PAGE_SIZE, 0);;
                        count -= PAGE_SIZE;
                }
        }
@@ -4513,6 +4465,7 @@ static int sgl_map_user_pages(struct scatterlist *sgl, const unsigned int max_pa
        if (res > 0) {
                for (j=0; j < res; j++)
                        page_cache_release(pages[j]);
+               res = 0;
        }
        kfree(pages);
        return res;
@@ -4526,10 +4479,8 @@ static int sgl_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_p
        int i;
 
        for (i=0; i < nr_pages; i++) {
-               struct page *page = sgl[i].page;
+               struct page *page = sg_page(&sgl[i]);
 
-               /* XXX: just for debug. Remove when PageReserved is removed */
-               BUG_ON(PageReserved(page));
                if (dirtied)
                        SetPageDirty(page);
                /* FIXME: cache flush missing for rw==READ