Merge ../scsi-misc-2.6
[linux-3.10.git] / drivers / scsi / sg.c
index 51292f2..65eef33 100644 (file)
@@ -28,7 +28,6 @@ static int sg_version_num = 30533;    /* 2 digits for each component */
  *        (otherwise the macros compile to empty statements).
  *
  */
-#include <linux/config.h>
 #include <linux/module.h>
 
 #include <linux/fs.h>
@@ -44,11 +43,11 @@ static int sg_version_num = 30533;  /* 2 digits for each component */
 #include <linux/poll.h>
 #include <linux/smp_lock.h>
 #include <linux/moduleparam.h>
-#include <linux/devfs_fs_kernel.h>
 #include <linux/cdev.h>
 #include <linux/seq_file.h>
 #include <linux/blkdev.h>
 #include <linux/delay.h>
+#include <linux/scatterlist.h>
 
 #include "scsi.h"
 #include <scsi/scsi_dbg.h>
@@ -61,16 +60,12 @@ static int sg_version_num = 30533;  /* 2 digits for each component */
 
 #ifdef CONFIG_SCSI_PROC_FS
 #include <linux/proc_fs.h>
-static char *sg_version_date = "20050328";
+static char *sg_version_date = "20050908";
 
 static int sg_proc_init(void);
 static void sg_proc_cleanup(void);
 #endif
 
-#ifndef LINUX_VERSION_CODE
-#include <linux/version.h>
-#endif                         /* LINUX_VERSION_CODE */
-
 #define SG_ALLOW_DIO_DEF 0
 #define SG_ALLOW_DIO_CODE /* compile out by commenting this define */
 
@@ -104,10 +99,8 @@ static int sg_allow_dio = SG_ALLOW_DIO_DEF;
 
 #define SG_DEV_ARR_LUMP 32     /* amount to over allocate sg_dev_arr by */
 
-static int sg_add(struct class_device *);
-static void sg_remove(struct class_device *);
-
-static Scsi_Request *dummy_cmdp;       /* only used for sizeof */
+static int sg_add(struct class_device *, struct class_interface *);
+static void sg_remove(struct class_device *, struct class_interface *);
 
 static DEFINE_RWLOCK(sg_dev_arr_lock); /* Also used to lock
                                                           file descriptor list for device */
@@ -122,7 +115,7 @@ typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
        unsigned short sglist_len; /* size of malloc'd scatter-gather list ++ */
        unsigned bufflen;       /* Size of (aggregate) data buffer */
        unsigned b_malloc_len;  /* actual len malloc'ed in buffer */
-       void *buffer;           /* Data buffer or scatter list (k_use_sg>0) */
+       struct scatterlist *buffer;/* scatter list */
        char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
        unsigned char cmd_opcode; /* first byte of command */
 } Sg_scatter_hold;
@@ -131,12 +124,11 @@ struct sg_device;         /* forward declarations */
 struct sg_fd;
 
 typedef struct sg_request {    /* SG_MAX_QUEUE requests outstanding per file */
-       Scsi_Request *my_cmdp;  /* != 0  when request with lower levels */
        struct sg_request *nextrp;      /* NULL -> tail request (slist) */
        struct sg_fd *parentfp; /* NULL -> not in use */
        Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
        sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
-       unsigned char sense_b[sizeof (dummy_cmdp->sr_sense_buffer)];
+       unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
        char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
        char orphan;            /* 1 -> drop on sight, 0 -> normal */
        char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
@@ -177,7 +169,8 @@ typedef struct sg_device { /* holds the state of each scsi generic device */
 } Sg_device;
 
 static int sg_fasync(int fd, struct file *filp, int mode);
-static void sg_cmd_done(Scsi_Cmnd * SCpnt);    /* tasklet or soft irq callback */
+/* tasklet or soft irq callback */
+static void sg_cmd_done(void *data, char *sense, int result, int resid);
 static int sg_start_req(Sg_request * srp);
 static void sg_finish_rem_req(Sg_request * srp);
 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
@@ -198,8 +191,8 @@ static void sg_remove_scat(Sg_scatter_hold * schp);
 static void sg_build_reserve(Sg_fd * sfp, int req_size);
 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
-static char *sg_page_malloc(int rqSz, int lowDma, int *retSzp);
-static void sg_page_free(char *buff, int size);
+static struct page *sg_page_malloc(int rqSz, int lowDma, int *retSzp);
+static void sg_page_free(struct page *page, int size);
 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
 static int sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
 static void __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
@@ -210,7 +203,6 @@ static int sg_res_in_use(Sg_fd * sfp);
 static int sg_allow_access(unsigned char opcode, char dev_type);
 static int sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len);
 static Sg_device *sg_get_dev(int dev);
-static inline unsigned char *sg_scatg2virt(const struct scatterlist *sclp);
 #ifdef CONFIG_SCSI_PROC_FS
 static int sg_last_dev(void);
 #endif
@@ -229,6 +221,7 @@ sg_open(struct inode *inode, struct file *filp)
 {
        int dev = iminor(inode);
        int flags = filp->f_flags;
+       struct request_queue *q;
        Sg_device *sdp;
        Sg_fd *sfp;
        int res;
@@ -290,7 +283,9 @@ sg_open(struct inode *inode, struct file *filp)
        }
        if (!sdp->headfp) {     /* no existing opens on this device */
                sdp->sgdebug = 0;
-               sdp->sg_tablesize = sdp->device->host->sg_tablesize;
+               q = sdp->device->request_queue;
+               sdp->sg_tablesize = min(q->max_hw_segments,
+                                       q->max_phys_segments);
        }
        if ((sfp = sg_add_sfp(sdp, dev)))
                filp->private_data = sfp;
@@ -343,6 +338,7 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
                return -ENXIO;
        SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
                                   sdp->disk->disk_name, (int) count));
+
        if (!access_ok(VERIFY_WRITE, buf, count))
                return -EFAULT;
        if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
@@ -475,8 +471,7 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
        sg_finish_rem_req(srp);
        retval = count;
 free_old_hdr:
-       if (old_hdr)
-               kfree(old_hdr);
+       kfree(old_hdr);
        return retval;
 }
 
@@ -495,7 +490,7 @@ sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
        if ((hp->mx_sb_len > 0) && hp->sbp) {
                if ((CHECK_CONDITION & hp->masked_status) ||
                    (DRIVER_SENSE & hp->driver_status)) {
-                       int sb_len = sizeof (dummy_cmdp->sr_sense_buffer);
+                       int sb_len = SCSI_SENSE_BUFFERSIZE;
                        sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
                        len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
                        len = (len > sb_len) ? sb_len : len;
@@ -529,7 +524,7 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
        Sg_request *srp;
        struct sg_header old_hdr;
        sg_io_hdr_t *hp;
-       unsigned char cmnd[sizeof (dummy_cmdp->sr_cmnd)];
+       unsigned char cmnd[MAX_COMMAND_SIZE];
 
        if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
                return -ENXIO;
@@ -628,7 +623,7 @@ sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
        int k;
        Sg_request *srp;
        sg_io_hdr_t *hp;
-       unsigned char cmnd[sizeof (dummy_cmdp->sr_cmnd)];
+       unsigned char cmnd[MAX_COMMAND_SIZE];
        int timeout;
        unsigned long ul_timeout;
 
@@ -696,11 +691,9 @@ static int
 sg_common_write(Sg_fd * sfp, Sg_request * srp,
                unsigned char *cmnd, int timeout, int blocking)
 {
-       int k;
-       Scsi_Request *SRpnt;
+       int k, data_dir;
        Sg_device *sdp = sfp->parentdp;
        sg_io_hdr_t *hp = &srp->header;
-       request_queue_t *q;
 
        srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
        hp->status = 0;
@@ -727,51 +720,37 @@ sg_common_write(Sg_fd * sfp, Sg_request * srp,
                sg_finish_rem_req(srp);
                return -ENODEV;
        }
-       SRpnt = scsi_allocate_request(sdp->device, GFP_ATOMIC);
-       if (SRpnt == NULL) {
-               SCSI_LOG_TIMEOUT(1, printk("sg_write: no mem\n"));
-               sg_finish_rem_req(srp);
-               return -ENOMEM;
-       }
 
-       srp->my_cmdp = SRpnt;
-       q = SRpnt->sr_device->request_queue;
-       SRpnt->sr_request->rq_disk = sdp->disk;
-       SRpnt->sr_sense_buffer[0] = 0;
-       SRpnt->sr_cmd_len = hp->cmd_len;
-       SRpnt->sr_use_sg = srp->data.k_use_sg;
-       SRpnt->sr_sglist_len = srp->data.sglist_len;
-       SRpnt->sr_bufflen = srp->data.bufflen;
-       SRpnt->sr_underflow = 0;
-       SRpnt->sr_buffer = srp->data.buffer;
        switch (hp->dxfer_direction) {
        case SG_DXFER_TO_FROM_DEV:
        case SG_DXFER_FROM_DEV:
-               SRpnt->sr_data_direction = DMA_FROM_DEVICE;
+               data_dir = DMA_FROM_DEVICE;
                break;
        case SG_DXFER_TO_DEV:
-               SRpnt->sr_data_direction = DMA_TO_DEVICE;
+               data_dir = DMA_TO_DEVICE;
                break;
        case SG_DXFER_UNKNOWN:
-               SRpnt->sr_data_direction = DMA_BIDIRECTIONAL;
+               data_dir = DMA_BIDIRECTIONAL;
                break;
        default:
-               SRpnt->sr_data_direction = DMA_NONE;
+               data_dir = DMA_NONE;
                break;
        }
-       SRpnt->upper_private_data = srp;
-       srp->data.k_use_sg = 0;
-       srp->data.sglist_len = 0;
-       srp->data.bufflen = 0;
-       srp->data.buffer = NULL;
        hp->duration = jiffies_to_msecs(jiffies);
 /* Now send everything of to mid-level. The next time we hear about this
    packet is when sg_cmd_done() is called (i.e. a callback). */
-       scsi_do_req(SRpnt, (void *) cmnd,
-                   (void *) SRpnt->sr_buffer, hp->dxfer_len,
-                   sg_cmd_done, timeout, SG_DEFAULT_RETRIES);
-       /* dxfer_len overwrites SRpnt->sr_bufflen, hence need for b_malloc_len */
-       return 0;
+       if (scsi_execute_async(sdp->device, cmnd, hp->cmd_len, data_dir, srp->data.buffer,
+                               hp->dxfer_len, srp->data.k_use_sg, timeout,
+                               SG_DEFAULT_RETRIES, srp, sg_cmd_done,
+                               GFP_ATOMIC)) {
+               SCSI_LOG_TIMEOUT(1, printk("sg_write: scsi_execute_async failed\n"));
+               /*
+                * most likely out of mem, but could also be a bad map
+                */
+               sg_finish_rem_req(srp);
+               return -ENOMEM;
+       } else
+               return 0;
 }
 
 static int
@@ -1027,8 +1006,7 @@ sg_ioctl(struct inode *inode, struct file *filp,
                if (sdp->detached)
                        return -ENODEV;
                if (filp->f_flags & O_NONBLOCK) {
-                       if (test_bit(SHOST_RECOVERY,
-                                    &sdp->device->host->shost_state))
+                       if (scsi_host_in_recovery(sdp->device->host))
                                return -EBUSY;
                } else if (!scsi_block_when_processing_errors(sdp->device))
                        return -EBUSY;
@@ -1066,7 +1044,7 @@ sg_ioctl(struct inode *inode, struct file *filp,
                        if (!sg_allow_access(opcode, sdp->device->type))
                                return -EPERM;
                }
-               return scsi_ioctl_send_command(sdp->device, p);
+               return sg_scsi_ioctl(filp, sdp->device->request_queue, NULL, p);
        case SG_SET_DEBUG:
                result = get_user(val, ip);
                if (result)
@@ -1161,63 +1139,15 @@ sg_fasync(int fd, struct file *filp, int mode)
        return (retval < 0) ? retval : 0;
 }
 
-static inline unsigned char *
-sg_scatg2virt(const struct scatterlist *sclp)
-{
-       return (sclp && sclp->page) ?
-           (unsigned char *) page_address(sclp->page) + sclp->offset : NULL;
-}
-
-/* When startFinish==1 increments page counts for pages other than the 
-   first of scatter gather elements obtained from __get_free_pages().
-   When startFinish==0 decrements ... */
-static void
-sg_rb_correct4mmap(Sg_scatter_hold * rsv_schp, int startFinish)
-{
-       void *page_ptr;
-       struct page *page;
-       int k, m;
-
-       SCSI_LOG_TIMEOUT(3, printk("sg_rb_correct4mmap: startFinish=%d, scatg=%d\n", 
-                                  startFinish, rsv_schp->k_use_sg));
-       /* N.B. correction _not_ applied to base page of each allocation */
-       if (rsv_schp->k_use_sg) {       /* reserve buffer is a scatter gather list */
-               struct scatterlist *sclp = rsv_schp->buffer;
-
-               for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sclp) {
-                       for (m = PAGE_SIZE; m < sclp->length; m += PAGE_SIZE) {
-                               page_ptr = sg_scatg2virt(sclp) + m;
-                               page = virt_to_page(page_ptr);
-                               if (startFinish)
-                                       get_page(page);
-                               else {
-                                       if (page_count(page) > 0)
-                                               __put_page(page);
-                               }
-                       }
-               }
-       } else {                /* reserve buffer is just a single allocation */
-               for (m = PAGE_SIZE; m < rsv_schp->bufflen; m += PAGE_SIZE) {
-                       page_ptr = (unsigned char *) rsv_schp->buffer + m;
-                       page = virt_to_page(page_ptr);
-                       if (startFinish)
-                               get_page(page);
-                       else {
-                               if (page_count(page) > 0)
-                                       __put_page(page);
-                       }
-               }
-       }
-}
-
 static struct page *
 sg_vma_nopage(struct vm_area_struct *vma, unsigned long addr, int *type)
 {
        Sg_fd *sfp;
        struct page *page = NOPAGE_SIGBUS;
-       void *page_ptr = NULL;
-       unsigned long offset;
+       unsigned long offset, len, sa;
        Sg_scatter_hold *rsv_schp;
+       struct scatterlist *sg;
+       int k;
 
        if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
                return page;
@@ -1227,30 +1157,21 @@ sg_vma_nopage(struct vm_area_struct *vma, unsigned long addr, int *type)
                return page;
        SCSI_LOG_TIMEOUT(3, printk("sg_vma_nopage: offset=%lu, scatg=%d\n",
                                   offset, rsv_schp->k_use_sg));
-       if (rsv_schp->k_use_sg) {       /* reserve buffer is a scatter gather list */
-               int k;
-               unsigned long sa = vma->vm_start;
-               unsigned long len;
-               struct scatterlist *sclp = rsv_schp->buffer;
-
-               for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
-                    ++k, ++sclp) {
-                       len = vma->vm_end - sa;
-                       len = (len < sclp->length) ? len : sclp->length;
-                       if (offset < len) {
-                               page_ptr = sg_scatg2virt(sclp) + offset;
-                               page = virt_to_page(page_ptr);
-                               get_page(page); /* increment page count */
-                               break;
-                       }
-                       sa += len;
-                       offset -= len;
+       sg = rsv_schp->buffer;
+       sa = vma->vm_start;
+       for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
+            ++k, ++sg) {
+               len = vma->vm_end - sa;
+               len = (len < sg->length) ? len : sg->length;
+               if (offset < len) {
+                       page = sg->page;
+                       get_page(page); /* increment page count */
+                       break;
                }
-       } else {                /* reserve buffer is just a single allocation */
-               page_ptr = (unsigned char *) rsv_schp->buffer + offset;
-               page = virt_to_page(page_ptr);
-               get_page(page); /* increment page count */
+               sa += len;
+               offset -= len;
        }
+
        if (type)
                *type = VM_FAULT_MINOR;
        return page;
@@ -1264,8 +1185,10 @@ static int
 sg_mmap(struct file *filp, struct vm_area_struct *vma)
 {
        Sg_fd *sfp;
-       unsigned long req_sz;
+       unsigned long req_sz, len, sa;
        Sg_scatter_hold *rsv_schp;
+       int k;
+       struct scatterlist *sg;
 
        if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
                return -ENXIO;
@@ -1278,29 +1201,17 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma)
        if (req_sz > rsv_schp->bufflen)
                return -ENOMEM; /* cannot map more than reserved buffer */
 
-       if (rsv_schp->k_use_sg) { /* reserve buffer is a scatter gather list */
-               int k;
-               unsigned long sa = vma->vm_start;
-               unsigned long len;
-               struct scatterlist *sclp = rsv_schp->buffer;
-
-               for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
-                    ++k, ++sclp) {
-                       if (0 != sclp->offset)
-                               return -EFAULT; /* non page aligned memory ?? */
-                       len = vma->vm_end - sa;
-                       len = (len < sclp->length) ? len : sclp->length;
-                       sa += len;
-               }
-       } else {        /* reserve buffer is just a single allocation */
-               if ((unsigned long) rsv_schp->buffer & (PAGE_SIZE - 1))
-                       return -EFAULT; /* non page aligned memory ?? */
+       sa = vma->vm_start;
+       sg = rsv_schp->buffer;
+       for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
+            ++k, ++sg) {
+               len = vma->vm_end - sa;
+               len = (len < sg->length) ? len : sg->length;
+               sa += len;
        }
-       if (0 == sfp->mmap_called) {
-               sg_rb_correct4mmap(rsv_schp, 1);        /* do only once per fd lifetime */
-               sfp->mmap_called = 1;
-       }
-       vma->vm_flags |= (VM_RESERVED | VM_IO);
+
+       sfp->mmap_called = 1;
+       vma->vm_flags |= VM_RESERVED;
        vma->vm_private_data = sfp;
        vma->vm_ops = &sg_mmap_vm_ops;
        return 0;
@@ -1309,21 +1220,16 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma)
 /* This function is a "bottom half" handler that is called by the
  * mid level when a command is completed (or has failed). */
 static void
-sg_cmd_done(Scsi_Cmnd * SCpnt)
+sg_cmd_done(void *data, char *sense, int result, int resid)
 {
-       Scsi_Request *SRpnt = NULL;
+       Sg_request *srp = data;
        Sg_device *sdp = NULL;
        Sg_fd *sfp;
-       Sg_request *srp = NULL;
        unsigned long iflags;
        unsigned int ms;
 
-       if (SCpnt && (SRpnt = SCpnt->sc_request))
-               srp = (Sg_request *) SRpnt->upper_private_data;
        if (NULL == srp) {
                printk(KERN_ERR "sg_cmd_done: NULL request\n");
-               if (SRpnt)
-                       scsi_release_request(SRpnt);
                return;
        }
        sfp = srp->parentfp;
@@ -1331,49 +1237,34 @@ sg_cmd_done(Scsi_Cmnd * SCpnt)
                sdp = sfp->parentdp;
        if ((NULL == sdp) || sdp->detached) {
                printk(KERN_INFO "sg_cmd_done: device detached\n");
-               scsi_release_request(SRpnt);
                return;
        }
 
-       /* First transfer ownership of data buffers to sg_device object. */
-       srp->data.k_use_sg = SRpnt->sr_use_sg;
-       srp->data.sglist_len = SRpnt->sr_sglist_len;
-       srp->data.bufflen = SRpnt->sr_bufflen;
-       srp->data.buffer = SRpnt->sr_buffer;
-       /* now clear out request structure */
-       SRpnt->sr_use_sg = 0;
-       SRpnt->sr_sglist_len = 0;
-       SRpnt->sr_bufflen = 0;
-       SRpnt->sr_buffer = NULL;
-       SRpnt->sr_underflow = 0;
-       SRpnt->sr_request->rq_disk = NULL; /* "sg" _disowns_ request blk */
-
-       srp->my_cmdp = NULL;
 
        SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
-               sdp->disk->disk_name, srp->header.pack_id, (int) SRpnt->sr_result));
-       srp->header.resid = SCpnt->resid;
+               sdp->disk->disk_name, srp->header.pack_id, result));
+       srp->header.resid = resid;
        ms = jiffies_to_msecs(jiffies);
        srp->header.duration = (ms > srp->header.duration) ?
                                (ms - srp->header.duration) : 0;
-       if (0 != SRpnt->sr_result) {
+       if (0 != result) {
                struct scsi_sense_hdr sshdr;
 
-               memcpy(srp->sense_b, SRpnt->sr_sense_buffer,
-                      sizeof (srp->sense_b));
-               srp->header.status = 0xff & SRpnt->sr_result;
-               srp->header.masked_status = status_byte(SRpnt->sr_result);
-               srp->header.msg_status = msg_byte(SRpnt->sr_result);
-               srp->header.host_status = host_byte(SRpnt->sr_result);
-               srp->header.driver_status = driver_byte(SRpnt->sr_result);
+               memcpy(srp->sense_b, sense, sizeof (srp->sense_b));
+               srp->header.status = 0xff & result;
+               srp->header.masked_status = status_byte(result);
+               srp->header.msg_status = msg_byte(result);
+               srp->header.host_status = host_byte(result);
+               srp->header.driver_status = driver_byte(result);
                if ((sdp->sgdebug > 0) &&
                    ((CHECK_CONDITION == srp->header.masked_status) ||
                     (COMMAND_TERMINATED == srp->header.masked_status)))
-                       scsi_print_req_sense("sg_cmd_done", SRpnt);
+                       __scsi_print_sense("sg_cmd_done", sense,
+                                          SCSI_SENSE_BUFFERSIZE);
 
                /* Following if statement is a patch supplied by Eric Youngdale */
-               if (driver_byte(SRpnt->sr_result) != 0
-                   && scsi_command_normalize_sense(SCpnt, &sshdr)
+               if (driver_byte(result) != 0
+                   && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
                    && !scsi_sense_is_deferred(&sshdr)
                    && sshdr.sense_key == UNIT_ATTENTION
                    && sdp->device->removable) {
@@ -1384,8 +1275,6 @@ sg_cmd_done(Scsi_Cmnd * SCpnt)
        }
        /* Rely on write phase to clean out srp status values, so no "else" */
 
-       scsi_release_request(SRpnt);
-       SRpnt = NULL;
        if (sfp->closed) {      /* whoops this fd already released, cleanup */
                SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
                sg_finish_rem_req(srp);
@@ -1436,12 +1325,13 @@ static int sg_sysfs_valid = 0;
 
 static int sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
 {
+       struct request_queue *q = scsidp->request_queue;
        Sg_device *sdp;
        unsigned long iflags;
        void *old_sg_dev_arr = NULL;
        int k, error;
 
-       sdp = kmalloc(sizeof(Sg_device), GFP_KERNEL);
+       sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
        if (!sdp) {
                printk(KERN_WARNING "kmalloc Sg_device failure\n");
                return -ENOMEM;
@@ -1453,12 +1343,11 @@ static int sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
                int tmp_dev_max = sg_nr_dev + SG_DEV_ARR_LUMP;
                write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
 
-               tmp_da = kmalloc(tmp_dev_max * sizeof(Sg_device *), GFP_KERNEL);
+               tmp_da = kzalloc(tmp_dev_max * sizeof(Sg_device *), GFP_KERNEL);
                if (unlikely(!tmp_da))
                        goto expand_failed;
 
                write_lock_irqsave(&sg_dev_arr_lock, iflags);
-               memset(tmp_da, 0, tmp_dev_max * sizeof(Sg_device *));
                memcpy(tmp_da, sg_dev_arr, sg_dev_max * sizeof(Sg_device *));
                old_sg_dev_arr = sg_dev_arr;
                sg_dev_arr = tmp_da;
@@ -1471,14 +1360,13 @@ static int sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
        if (unlikely(k >= SG_MAX_DEVS))
                goto overflow;
 
-       memset(sdp, 0, sizeof(*sdp));
        SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
        sprintf(disk->disk_name, "sg%d", k);
        disk->first_minor = k;
        sdp->disk = disk;
        sdp->device = scsidp;
        init_waitqueue_head(&sdp->o_excl_wait);
-       sdp->sg_tablesize = scsidp->host ? scsidp->host->sg_tablesize : 0;
+       sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments);
 
        sg_nr_dev++;
        sg_dev_arr[k] = sdp;
@@ -1498,22 +1386,22 @@ static int sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
 
  overflow:
        write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
-       printk(KERN_WARNING
-              "Unable to attach sg device <%d, %d, %d, %d> type=%d, minor "
-              "number exceeds %d\n", scsidp->host->host_no, scsidp->channel,
-              scsidp->id, scsidp->lun, scsidp->type, SG_MAX_DEVS - 1);
+       sdev_printk(KERN_WARNING, scsidp,
+                   "Unable to attach sg device type=%d, minor "
+                   "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
        error = -ENODEV;
        goto out;
 }
 
 static int
-sg_add(struct class_device *cl_dev)
+sg_add(struct class_device *cl_dev, struct class_interface *cl_intf)
 {
        struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
        struct gendisk *disk;
        Sg_device *sdp = NULL;
        struct cdev * cdev = NULL;
        int error, k;
+       unsigned long iflags;
 
        disk = alloc_disk(1);
        if (!disk) {
@@ -1539,19 +1427,15 @@ sg_add(struct class_device *cl_dev)
        k = error;
        sdp = sg_dev_arr[k];
 
-       devfs_mk_cdev(MKDEV(SCSI_GENERIC_MAJOR, k),
-                       S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP,
-                       "%s/generic", scsidp->devfs_name);
        error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, k), 1);
-       if (error) {
-               devfs_remove("%s/generic", scsidp->devfs_name);
-               goto out;
-       }
+       if (error)
+               goto cdev_add_err;
+
        sdp->cdev = cdev;
        if (sg_sysfs_valid) {
                struct class_device * sg_class_member;
 
-               sg_class_member = class_device_create(sg_sysfs_class,
+               sg_class_member = class_device_create(sg_sysfs_class, NULL,
                                MKDEV(SCSI_GENERIC_MAJOR, k), 
                                cl_dev->dev, "%s", 
                                disk->disk_name);
@@ -1567,14 +1451,18 @@ sg_add(struct class_device *cl_dev)
        } else
                printk(KERN_WARNING "sg_add: sg_sys INvalid\n");
 
-       printk(KERN_NOTICE
-              "Attached scsi generic sg%d at scsi%d, channel"
-              " %d, id %d, lun %d,  type %d\n", k,
-              scsidp->host->host_no, scsidp->channel, scsidp->id,
-              scsidp->lun, scsidp->type);
+       sdev_printk(KERN_NOTICE, scsidp,
+                   "Attached scsi generic sg%d type %d\n", k,scsidp->type);
 
        return 0;
 
+cdev_add_err:
+       write_lock_irqsave(&sg_dev_arr_lock, iflags);
+       kfree(sg_dev_arr[k]);
+       sg_dev_arr[k] = NULL;
+       sg_nr_dev--;
+       write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
+
 out:
        put_disk(disk);
        if (cdev)
@@ -1583,7 +1471,7 @@ out:
 }
 
 static void
-sg_remove(struct class_device *cl_dev)
+sg_remove(struct class_device *cl_dev, struct class_interface *cl_intf)
 {
        struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
        Sg_device *sdp = NULL;
@@ -1639,7 +1527,6 @@ sg_remove(struct class_device *cl_dev)
                class_device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, k));
                cdev_del(sdp->cdev);
                sdp->cdev = NULL;
-               devfs_remove("%s/generic", scsidp->devfs_name);
                put_disk(sdp->disk);
                sdp->disk = NULL;
                if (NULL == sdp->headfp)
@@ -1661,6 +1548,7 @@ MODULE_AUTHOR("Douglas Gilbert");
 MODULE_DESCRIPTION("SCSI generic (sg) driver");
 MODULE_LICENSE("GPL");
 MODULE_VERSION(SG_VERSION_STR);
+MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
 
 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
@@ -1707,10 +1595,8 @@ exit_sg(void)
        sg_sysfs_valid = 0;
        unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
                                 SG_MAX_DEVS);
-       if (sg_dev_arr != NULL) {
-               kfree((char *) sg_dev_arr);
-               sg_dev_arr = NULL;
-       }
+       kfree((char *)sg_dev_arr);
+       sg_dev_arr = NULL;
        sg_dev_max = 0;
 }
 
@@ -1764,43 +1650,42 @@ sg_finish_rem_req(Sg_request * srp)
 static int
 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
 {
-       int ret_sz;
-       int elem_sz = sizeof (struct scatterlist);
-       int sg_bufflen = tablesize * elem_sz;
-       int mx_sc_elems = tablesize;
+       int sg_bufflen = tablesize * sizeof(struct scatterlist);
+       gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
 
-       schp->buffer = sg_page_malloc(sg_bufflen, sfp->low_dma, &ret_sz);
+       /*
+        * TODO: test without low_dma, we should not need it since
+        * the block layer will bounce the buffer for us
+        *
+        * XXX(hch): we shouldn't need GFP_DMA for the actual S/G list.
+        */
+       if (sfp->low_dma)
+                gfp_flags |= GFP_DMA;
+       schp->buffer = kzalloc(sg_bufflen, gfp_flags);
        if (!schp->buffer)
                return -ENOMEM;
-       else if (ret_sz != sg_bufflen) {
-               sg_bufflen = ret_sz;
-               mx_sc_elems = sg_bufflen / elem_sz;
-       }
        schp->sglist_len = sg_bufflen;
-       memset(schp->buffer, 0, sg_bufflen);
-       return mx_sc_elems;     /* number of scat_gath elements allocated */
+       return tablesize;       /* number of scat_gath elements allocated */
 }
 
 #ifdef SG_ALLOW_DIO_CODE
 /* vvvvvvvv  following code borrowed from st driver's direct IO vvvvvvvvv */
-       /* hopefully this generic code will moved to a library */
+       /* TODO: hopefully we can use the generic block layer code */
 
 /* 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)
+                 unsigned long uaddr, size_t count, int rw)
 {
+       unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
+       unsigned long start = uaddr >> PAGE_SHIFT;
+       const int nr_pages = end - start;
        int res, i, j;
-       unsigned int nr_pages;
        struct page **pages;
 
-       nr_pages = ((uaddr & ~PAGE_MASK) + count + ~PAGE_MASK) >> PAGE_SHIFT;
-
        /* User attempted Overflow! */
        if ((uaddr + count) < uaddr)
                return -EINVAL;
@@ -1839,21 +1724,17 @@ st_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages,
                  * probably wrong function for rw==WRITE
                  */
                flush_dcache_page(pages[i]);
-               if (page_to_pfn(pages[i]) > max_pfn)
-                       goto out_unlock;
                /* ?? Is locking needed? I don't think so */
                /* if (TestSetPageLocked(pages[i]))
                   goto out_unlock; */
         }
 
-       /* Populate the scatter/gather list */
-       sgl[0].page = pages[0]; 
+       sgl[0].page = pages[0];
        sgl[0].offset = 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;
                        count -= PAGE_SIZE;
@@ -1866,14 +1747,12 @@ st_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages,
        kfree(pages);
        return nr_pages;
 
- out_unlock:
-       /* for (j=0; j < i; j++)
-          unlock_page(pages[j]); */
-       res = 0;
  out_unmap:
-       if (res > 0)
+       if (res > 0) {
                for (j=0; j < res; j++)
                        page_cache_release(pages[j]);
+               res = 0;
+       }
        kfree(pages);
        return res;
 }
@@ -1887,13 +1766,15 @@ st_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_pages,
        int i;
 
        for (i=0; i < nr_pages; i++) {
-               if (dirtied && !PageReserved(sgl[i].page))
-                       SetPageDirty(sgl[i].page);
-               /* unlock_page(sgl[i].page); */
+               struct page *page = sgl[i].page;
+
+               if (dirtied)
+                       SetPageDirty(page);
+               /* unlock_page(page); */
                /* FIXME: cache flush missing for rw==READ
                 * FIXME: call the correct reference counting function
                 */
-               page_cache_release(sgl[i].page);
+               page_cache_release(page);
        }
 
        return 0;
@@ -1911,22 +1792,24 @@ sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len)
        sg_io_hdr_t *hp = &srp->header;
        Sg_scatter_hold *schp = &srp->data;
        int sg_tablesize = sfp->parentdp->sg_tablesize;
-       struct scatterlist *sgl;
        int mx_sc_elems, res;
        struct scsi_device *sdev = sfp->parentdp->device;
 
        if (((unsigned long)hp->dxferp &
                        queue_dma_alignment(sdev->request_queue)) != 0)
                return 1;
+
        mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
         if (mx_sc_elems <= 0) {
                 return 1;
         }
-       sgl = (struct scatterlist *)schp->buffer;
-       res = st_map_user_pages(sgl, mx_sc_elems, (unsigned long)hp->dxferp, dxfer_len, 
-                               (SG_DXFER_TO_DEV == hp->dxfer_direction) ? 1 : 0, ULONG_MAX);
-       if (res <= 0)
+       res = st_map_user_pages(schp->buffer, mx_sc_elems,
+                               (unsigned long)hp->dxferp, dxfer_len, 
+                               (SG_DXFER_TO_DEV == hp->dxfer_direction) ? 1 : 0);
+       if (res <= 0) {
+               sg_remove_scat(schp);
                return 1;
+       }
        schp->k_use_sg = res;
        schp->dio_in_use = 1;
        hp->info |= SG_INFO_DIRECT_IO;
@@ -1939,9 +1822,11 @@ sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len)
 static int
 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
 {
-       int ret_sz;
+       struct scatterlist *sg;
+       int ret_sz = 0, k, rem_sz, num, mx_sc_elems;
+       int sg_tablesize = sfp->parentdp->sg_tablesize;
        int blk_size = buff_size;
-       unsigned char *p = NULL;
+       struct page *p = NULL;
 
        if ((blk_size < 0) || (!sfp))
                return -EFAULT;
@@ -1951,61 +1836,35 @@ sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
        blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
        SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
                                   buff_size, blk_size));
-       if (blk_size <= SG_SCATTER_SZ) {
-               p = sg_page_malloc(blk_size, sfp->low_dma, &ret_sz);
-               if (!p)
-                       return -ENOMEM;
-               if (blk_size == ret_sz) {       /* got it on the first attempt */
-                       schp->k_use_sg = 0;
-                       schp->buffer = p;
-                       schp->bufflen = blk_size;
-                       schp->b_malloc_len = blk_size;
-                       return 0;
-               }
-       } else {
-               p = sg_page_malloc(SG_SCATTER_SZ, sfp->low_dma, &ret_sz);
+
+       /* N.B. ret_sz carried into this block ... */
+       mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
+       if (mx_sc_elems < 0)
+               return mx_sc_elems;     /* most likely -ENOMEM */
+
+       for (k = 0, sg = schp->buffer, rem_sz = blk_size;
+            (rem_sz > 0) && (k < mx_sc_elems);
+            ++k, rem_sz -= ret_sz, ++sg) {
+               
+               num = (rem_sz > SG_SCATTER_SZ) ? SG_SCATTER_SZ : rem_sz;
+               p = sg_page_malloc(num, sfp->low_dma, &ret_sz);
                if (!p)
                        return -ENOMEM;
-       }
-/* Want some local declarations, so start new block ... */
-       {                       /* lets try and build a scatter gather list */
-               struct scatterlist *sclp;
-               int k, rem_sz, num;
-               int mx_sc_elems;
-               int sg_tablesize = sfp->parentdp->sg_tablesize;
-               int first = 1;
-
-               /* N.B. ret_sz carried into this block ... */
-               mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
-               if (mx_sc_elems < 0)
-                       return mx_sc_elems;     /* most likely -ENOMEM */
-
-               for (k = 0, sclp = schp->buffer, rem_sz = blk_size;
-                    (rem_sz > 0) && (k < mx_sc_elems);
-                    ++k, rem_sz -= ret_sz, ++sclp) {
-                       if (first)
-                               first = 0;
-                       else {
-                               num =
-                                   (rem_sz >
-                                    SG_SCATTER_SZ) ? SG_SCATTER_SZ : rem_sz;
-                               p = sg_page_malloc(num, sfp->low_dma, &ret_sz);
-                               if (!p)
-                                       break;
-                       }
-                       sclp->page = virt_to_page(p);
-                       sclp->offset = offset_in_page(p);
-                       sclp->length = ret_sz;
-
-                       SCSI_LOG_TIMEOUT(5, printk("sg_build_build: k=%d, a=0x%p, len=%d\n",
-                                         k, sg_scatg2virt(sclp), ret_sz));
-               }               /* end of for loop */
-               schp->k_use_sg = k;
-               SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, rem_sz=%d\n", k, rem_sz));
-               schp->bufflen = blk_size;
-               if (rem_sz > 0) /* must have failed */
-                       return -ENOMEM;
-       }
+
+               sg->page = p;
+               sg->length = ret_sz;
+
+               SCSI_LOG_TIMEOUT(5, printk("sg_build_build: k=%d, a=0x%p, len=%d\n",
+                                 k, p, ret_sz));
+       }               /* end of for loop */
+
+       schp->k_use_sg = k;
+       SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, rem_sz=%d\n", k, rem_sz));
+
+       schp->bufflen = blk_size;
+       if (rem_sz > 0) /* must have failed */
+               return -ENOMEM;
+
        return 0;
 }
 
@@ -2014,6 +1873,7 @@ sg_write_xfer(Sg_request * srp)
 {
        sg_io_hdr_t *hp = &srp->header;
        Sg_scatter_hold *schp = &srp->data;
+       struct scatterlist *sg = schp->buffer;
        int num_xfer = 0;
        int j, k, onum, usglen, ksglen, res;
        int iovec_count = (int) hp->iovec_count;
@@ -2042,63 +1902,45 @@ sg_write_xfer(Sg_request * srp)
        } else
                onum = 1;
 
-       if (0 == schp->k_use_sg) {      /* kernel has single buffer */
-               for (j = 0, p = schp->buffer; j < onum; ++j) {
-                       res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
-                       if (res)
-                               return res;
-                       usglen = (num_xfer > usglen) ? usglen : num_xfer;
-                       if (__copy_from_user(p, up, usglen))
-                               return -EFAULT;
-                       p += usglen;
-                       num_xfer -= usglen;
-                       if (num_xfer <= 0)
-                               return 0;
-               }
-       } else {                /* kernel using scatter gather list */
-               struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
-
-               ksglen = (int) sclp->length;
-               p = sg_scatg2virt(sclp);
-               for (j = 0, k = 0; j < onum; ++j) {
-                       res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
-                       if (res)
-                               return res;
-
-                       for (; p; ++sclp, ksglen = (int) sclp->length,
-                                 p = sg_scatg2virt(sclp)) {
-                               if (usglen <= 0)
-                                       break;
-                               if (ksglen > usglen) {
-                                       if (usglen >= num_xfer) {
-                                               if (__copy_from_user
-                                                   (p, up, num_xfer))
-                                                       return -EFAULT;
-                                               return 0;
-                                       }
-                                       if (__copy_from_user(p, up, usglen))
-                                               return -EFAULT;
-                                       p += usglen;
-                                       ksglen -= usglen;
-                                       break;
-                               } else {
-                                       if (ksglen >= num_xfer) {
-                                               if (__copy_from_user
-                                                   (p, up, num_xfer))
-                                                       return -EFAULT;
-                                               return 0;
-                                       }
-                                       if (__copy_from_user(p, up, ksglen))
+       ksglen = sg->length;
+       p = page_address(sg->page);
+       for (j = 0, k = 0; j < onum; ++j) {
+               res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
+               if (res)
+                       return res;
+
+               for (; p; ++sg, ksglen = sg->length,
+                    p = page_address(sg->page)) {
+                       if (usglen <= 0)
+                               break;
+                       if (ksglen > usglen) {
+                               if (usglen >= num_xfer) {
+                                       if (__copy_from_user(p, up, num_xfer))
                                                return -EFAULT;
-                                       up += ksglen;
-                                       usglen -= ksglen;
+                                       return 0;
                                }
-                               ++k;
-                               if (k >= schp->k_use_sg)
+                               if (__copy_from_user(p, up, usglen))
+                                       return -EFAULT;
+                               p += usglen;
+                               ksglen -= usglen;
+                               break;
+                       } else {
+                               if (ksglen >= num_xfer) {
+                                       if (__copy_from_user(p, up, num_xfer))
+                                               return -EFAULT;
                                        return 0;
+                               }
+                               if (__copy_from_user(p, up, ksglen))
+                                       return -EFAULT;
+                               up += ksglen;
+                               usglen -= ksglen;
                        }
+                       ++k;
+                       if (k >= schp->k_use_sg)
+                               return 0;
                }
        }
+
        return 0;
 }
 
@@ -2136,29 +1978,25 @@ sg_remove_scat(Sg_scatter_hold * schp)
 {
        SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
        if (schp->buffer && (schp->sglist_len > 0)) {
-               struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
+               struct scatterlist *sg = schp->buffer;
 
                if (schp->dio_in_use) {
 #ifdef SG_ALLOW_DIO_CODE
-                       st_unmap_user_pages(sclp, schp->k_use_sg, TRUE);
+                       st_unmap_user_pages(sg, schp->k_use_sg, TRUE);
 #endif
                } else {
                        int k;
 
-                       for (k = 0; (k < schp->k_use_sg) && sg_scatg2virt(sclp);
-                            ++k, ++sclp) {
+                       for (k = 0; (k < schp->k_use_sg) && sg->page;
+                            ++k, ++sg) {
                                SCSI_LOG_TIMEOUT(5, printk(
                                    "sg_remove_scat: k=%d, a=0x%p, len=%d\n",
-                                   k, sg_scatg2virt(sclp), sclp->length));
-                               sg_page_free(sg_scatg2virt(sclp), sclp->length);
-                               sclp->page = NULL;
-                               sclp->offset = 0;
-                               sclp->length = 0;
+                                   k, sg->page, sg->length));
+                               sg_page_free(sg->page, sg->length);
                        }
                }
-               sg_page_free(schp->buffer, schp->sglist_len);
-       } else if (schp->buffer)
-               sg_page_free(schp->buffer, schp->b_malloc_len);
+               kfree(schp->buffer);
+       }
        memset(schp, 0, sizeof (*schp));
 }
 
@@ -2167,6 +2005,7 @@ sg_read_xfer(Sg_request * srp)
 {
        sg_io_hdr_t *hp = &srp->header;
        Sg_scatter_hold *schp = &srp->data;
+       struct scatterlist *sg = schp->buffer;
        int num_xfer = 0;
        int j, k, onum, usglen, ksglen, res;
        int iovec_count = (int) hp->iovec_count;
@@ -2195,63 +2034,45 @@ sg_read_xfer(Sg_request * srp)
        } else
                onum = 1;
 
-       if (0 == schp->k_use_sg) {      /* kernel has single buffer */
-               for (j = 0, p = schp->buffer; j < onum; ++j) {
-                       res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
-                       if (res)
-                               return res;
-                       usglen = (num_xfer > usglen) ? usglen : num_xfer;
-                       if (__copy_to_user(up, p, usglen))
-                               return -EFAULT;
-                       p += usglen;
-                       num_xfer -= usglen;
-                       if (num_xfer <= 0)
-                               return 0;
-               }
-       } else {                /* kernel using scatter gather list */
-               struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
-
-               ksglen = (int) sclp->length;
-               p = sg_scatg2virt(sclp);
-               for (j = 0, k = 0; j < onum; ++j) {
-                       res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
-                       if (res)
-                               return res;
-
-                       for (; p; ++sclp, ksglen = (int) sclp->length,
-                                 p = sg_scatg2virt(sclp)) {
-                               if (usglen <= 0)
-                                       break;
-                               if (ksglen > usglen) {
-                                       if (usglen >= num_xfer) {
-                                               if (__copy_to_user
-                                                   (up, p, num_xfer))
-                                                       return -EFAULT;
-                                               return 0;
-                                       }
-                                       if (__copy_to_user(up, p, usglen))
-                                               return -EFAULT;
-                                       p += usglen;
-                                       ksglen -= usglen;
-                                       break;
-                               } else {
-                                       if (ksglen >= num_xfer) {
-                                               if (__copy_to_user
-                                                   (up, p, num_xfer))
-                                                       return -EFAULT;
-                                               return 0;
-                                       }
-                                       if (__copy_to_user(up, p, ksglen))
+       p = page_address(sg->page);
+       ksglen = sg->length;
+       for (j = 0, k = 0; j < onum; ++j) {
+               res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
+               if (res)
+                       return res;
+
+               for (; p; ++sg, ksglen = sg->length,
+                    p = page_address(sg->page)) {
+                       if (usglen <= 0)
+                               break;
+                       if (ksglen > usglen) {
+                               if (usglen >= num_xfer) {
+                                       if (__copy_to_user(up, p, num_xfer))
                                                return -EFAULT;
-                                       up += ksglen;
-                                       usglen -= ksglen;
+                                       return 0;
                                }
-                               ++k;
-                               if (k >= schp->k_use_sg)
+                               if (__copy_to_user(up, p, usglen))
+                                       return -EFAULT;
+                               p += usglen;
+                               ksglen -= usglen;
+                               break;
+                       } else {
+                               if (ksglen >= num_xfer) {
+                                       if (__copy_to_user(up, p, num_xfer))
+                                               return -EFAULT;
                                        return 0;
+                               }
+                               if (__copy_to_user(up, p, ksglen))
+                                       return -EFAULT;
+                               up += ksglen;
+                               usglen -= ksglen;
                        }
+                       ++k;
+                       if (k >= schp->k_use_sg)
+                               return 0;
                }
        }
+
        return 0;
 }
 
@@ -2259,37 +2080,32 @@ static int
 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
 {
        Sg_scatter_hold *schp = &srp->data;
+       struct scatterlist *sg = schp->buffer;
+       int k, num;
 
        SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
                                   num_read_xfer));
        if ((!outp) || (num_read_xfer <= 0))
                return 0;
-       if (schp->k_use_sg > 0) {
-               int k, num;
-               struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
-
-               for (k = 0; (k < schp->k_use_sg) && sg_scatg2virt(sclp);
-                    ++k, ++sclp) {
-                       num = (int) sclp->length;
-                       if (num > num_read_xfer) {
-                               if (__copy_to_user
-                                   (outp, sg_scatg2virt(sclp), num_read_xfer))
-                                       return -EFAULT;
+
+       for (k = 0; (k < schp->k_use_sg) && sg->page; ++k, ++sg) {
+               num = sg->length;
+               if (num > num_read_xfer) {
+                       if (__copy_to_user(outp, page_address(sg->page),
+                                          num_read_xfer))
+                               return -EFAULT;
+                       break;
+               } else {
+                       if (__copy_to_user(outp, page_address(sg->page),
+                                          num))
+                               return -EFAULT;
+                       num_read_xfer -= num;
+                       if (num_read_xfer <= 0)
                                break;
-                       } else {
-                               if (__copy_to_user
-                                   (outp, sg_scatg2virt(sclp), num))
-                                       return -EFAULT;
-                               num_read_xfer -= num;
-                               if (num_read_xfer <= 0)
-                                       break;
-                               outp += num;
-                       }
+                       outp += num;
                }
-       } else {
-               if (__copy_to_user(outp, schp->buffer, num_read_xfer))
-                       return -EFAULT;
        }
+
        return 0;
 }
 
@@ -2315,44 +2131,31 @@ sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
 {
        Sg_scatter_hold *req_schp = &srp->data;
        Sg_scatter_hold *rsv_schp = &sfp->reserve;
+       struct scatterlist *sg = rsv_schp->buffer;
+       int k, num, rem;
 
        srp->res_used = 1;
        SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
-       size = (size + 1) & (~1);       /* round to even for aha1542 */
-       if (rsv_schp->k_use_sg > 0) {
-               int k, num;
-               int rem = size;
-               struct scatterlist *sclp =
-                   (struct scatterlist *) rsv_schp->buffer;
-
-               for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sclp) {
-                       num = (int) sclp->length;
-                       if (rem <= num) {
-                               if (0 == k) {
-                                       req_schp->k_use_sg = 0;
-                                       req_schp->buffer = sg_scatg2virt(sclp);
-                               } else {
-                                       sfp->save_scat_len = num;
-                                       sclp->length = (unsigned) rem;
-                                       req_schp->k_use_sg = k + 1;
-                                       req_schp->sglist_len =
-                                           rsv_schp->sglist_len;
-                                       req_schp->buffer = rsv_schp->buffer;
-                               }
-                               req_schp->bufflen = size;
-                               req_schp->b_malloc_len = rsv_schp->b_malloc_len;
-                               break;
-                       } else
-                               rem -= num;
-               }
-               if (k >= rsv_schp->k_use_sg)
-                       SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
-       } else {
-               req_schp->k_use_sg = 0;
-               req_schp->bufflen = size;
-               req_schp->buffer = rsv_schp->buffer;
-               req_schp->b_malloc_len = rsv_schp->b_malloc_len;
+       rem = size;
+
+       for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sg) {
+               num = sg->length;
+               if (rem <= num) {
+                       sfp->save_scat_len = num;
+                       sg->length = rem;
+                       req_schp->k_use_sg = k + 1;
+                       req_schp->sglist_len = rsv_schp->sglist_len;
+                       req_schp->buffer = rsv_schp->buffer;
+
+                       req_schp->bufflen = size;
+                       req_schp->b_malloc_len = rsv_schp->b_malloc_len;
+                       break;
+               } else
+                       rem -= num;
        }
+
+       if (k >= rsv_schp->k_use_sg)
+               SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
 }
 
 static void
@@ -2364,11 +2167,10 @@ sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
        SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
                                   (int) req_schp->k_use_sg));
        if ((rsv_schp->k_use_sg > 0) && (req_schp->k_use_sg > 0)) {
-               struct scatterlist *sclp =
-                   (struct scatterlist *) rsv_schp->buffer;
+               struct scatterlist *sg = rsv_schp->buffer;
 
                if (sfp->save_scat_len > 0)
-                       (sclp + (req_schp->k_use_sg - 1))->length =
+                       (sg + (req_schp->k_use_sg - 1))->length =
                            (unsigned) sfp->save_scat_len;
                else
                        SCSI_LOG_TIMEOUT(1, printk ("sg_unlink_reserve: BAD save_scat_len\n"));
@@ -2454,7 +2256,6 @@ sg_add_request(Sg_fd * sfp)
        if (resp) {
                resp->nextrp = NULL;
                resp->header.duration = jiffies_to_msecs(jiffies);
-               resp->my_cmdp = NULL;
        }
        write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
        return resp;
@@ -2472,8 +2273,6 @@ sg_remove_request(Sg_fd * sfp, Sg_request * srp)
        if ((!sfp) || (!srp) || (!sfp->headrp))
                return res;
        write_lock_irqsave(&sfp->rq_list_lock, iflags);
-       if (srp->my_cmdp)
-               srp->my_cmdp->upper_private_data = NULL;
        prev_rp = sfp->headrp;
        if (srp == prev_rp) {
                sfp->headrp = prev_rp->nextrp;
@@ -2516,10 +2315,10 @@ sg_add_sfp(Sg_device * sdp, int dev)
        Sg_fd *sfp;
        unsigned long iflags;
 
-       sfp = (Sg_fd *) sg_page_malloc(sizeof (Sg_fd), 0, NULL);
+       sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
        if (!sfp)
                return NULL;
-       memset(sfp, 0, sizeof (Sg_fd));
+
        init_waitqueue_head(&sfp->read_wait);
        rwlock_init(&sfp->rq_list_lock);
 
@@ -2570,13 +2369,11 @@ __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
                SCSI_LOG_TIMEOUT(6, 
                        printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
                        (int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
-               if (sfp->mmap_called)
-                       sg_rb_correct4mmap(&sfp->reserve, 0);   /* undo correction */
                sg_remove_scat(&sfp->reserve);
        }
        sfp->parentdp = NULL;
        SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
-       sg_page_free((char *) sfp, sizeof (Sg_fd));
+       kfree(sfp);
 }
 
 /* Returns 0 in normal case, 1 when detached and sdp object removed */
@@ -2641,11 +2438,11 @@ sg_res_in_use(Sg_fd * sfp)
 }
 
 /* If retSzp==NULL want exact size or fail */
-static char *
+static struct page *
 sg_page_malloc(int rqSz, int lowDma, int *retSzp)
 {
-       char *resp = NULL;
-       int page_mask;
+       struct page *resp = NULL;
+       gfp_t page_mask;
        int order, a_size;
        int resSz = rqSz;
 
@@ -2653,22 +2450,22 @@ sg_page_malloc(int rqSz, int lowDma, int *retSzp)
                return resp;
 
        if (lowDma)
-               page_mask = GFP_ATOMIC | GFP_DMA | __GFP_NOWARN;
+               page_mask = GFP_ATOMIC | GFP_DMA | __GFP_COMP | __GFP_NOWARN;
        else
-               page_mask = GFP_ATOMIC | __GFP_NOWARN;
+               page_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
 
        for (order = 0, a_size = PAGE_SIZE; a_size < rqSz;
             order++, a_size <<= 1) ;
-       resp = (char *) __get_free_pages(page_mask, order);
+       resp = alloc_pages(page_mask, order);
        while ((!resp) && order && retSzp) {
                --order;
                a_size >>= 1;   /* divide by 2, until PAGE_SIZE */
-               resp = (char *) __get_free_pages(page_mask, order);     /* try half */
+               resp =  alloc_pages(page_mask, order);  /* try half */
                resSz = a_size;
        }
        if (resp) {
                if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
-                       memset(resp, 0, resSz);
+                       memset(page_address(resp), 0, resSz);
                if (retSzp)
                        *retSzp = resSz;
        }
@@ -2676,15 +2473,15 @@ sg_page_malloc(int rqSz, int lowDma, int *retSzp)
 }
 
 static void
-sg_page_free(char *buff, int size)
+sg_page_free(struct page *page, int size)
 {
        int order, a_size;
 
-       if (!buff)
+       if (!page)
                return;
        for (order = 0, a_size = PAGE_SIZE; a_size < size;
             order++, a_size <<= 1) ;
-       free_pages((unsigned long) buff, order);
+       __free_pages(page, order);
 }
 
 #ifndef MAINTENANCE_IN_CMD
@@ -2845,13 +2642,11 @@ static int
 sg_proc_init(void)
 {
        int k, mask;
-       int num_leaves =
-           sizeof (sg_proc_leaf_arr) / sizeof (sg_proc_leaf_arr[0]);
+       int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
        struct proc_dir_entry *pdep;
        struct sg_proc_leaf * leaf;
 
-       sg_proc_sgp = create_proc_entry(sg_proc_sg_dirname,
-                                       S_IFDIR | S_IRUGO | S_IXUGO, NULL);
+       sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
        if (!sg_proc_sgp)
                return 1;
        for (k = 0; k < num_leaves; ++k) {
@@ -2872,8 +2667,7 @@ static void
 sg_proc_cleanup(void)
 {
        int k;
-       int num_leaves =
-           sizeof (sg_proc_leaf_arr) / sizeof (sg_proc_leaf_arr[0]);
+       int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
 
        if (!sg_proc_sgp)
                return;
@@ -2971,23 +2765,22 @@ static void * dev_seq_start(struct seq_file *s, loff_t *pos)
 {
        struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
 
+       s->private = it;
        if (! it)
                return NULL;
+
        if (NULL == sg_dev_arr)
-               goto err1;
+               return NULL;
        it->index = *pos;
        it->max = sg_last_dev();
        if (it->index >= it->max)
-               goto err1;
+               return NULL;
        return it;
-err1:
-       kfree(it);
-       return NULL;
 }
 
 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
 {
-       struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
+       struct sg_proc_deviter * it = s->private;
 
        *pos = ++it->index;
        return (it->index < it->max) ? it : NULL;
@@ -2995,7 +2788,7 @@ static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
 
 static void dev_seq_stop(struct seq_file *s, void *v)
 {
-       kfree (v);
+       kfree(s->private);
 }
 
 static int sg_proc_open_dev(struct inode *inode, struct file *file)
@@ -3078,13 +2871,11 @@ static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
                                        cp = "     ";
                        }
                        seq_printf(s, cp);
-                       blen = srp->my_cmdp ? 
-                               srp->my_cmdp->sr_bufflen : srp->data.bufflen;
-                       usg = srp->my_cmdp ? 
-                               srp->my_cmdp->sr_use_sg : srp->data.k_use_sg;
+                       blen = srp->data.bufflen;
+                       usg = srp->data.k_use_sg;
                        seq_printf(s, srp->done ? 
                                   ((1 == srp->done) ?  "rcv:" : "fin:")
-                                  : (srp->my_cmdp ? "act:" : "prior:"));
+                                  : "act:");
                        seq_printf(s, " id=%d blen=%d",
                                   srp->header.pack_id, blen);
                        if (srp->done)
@@ -3153,4 +2944,3 @@ static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
 
 module_init(init_sg);
 module_exit(exit_sg);
-MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);