sg: char_devs + seq_file lk2.6.0t9

From: 	Douglas Gilbert <dougg@torque.net>

This is an updated patch for the sg driver that takes into
account Patrick LaVarre's fix for negative reserved buffer
sizes found in lk 2.6.0-test9.

So it has the same changelog to the patch I sent on 2003/10/11:
     - add "struct cdev" [char_devs] objects to increase
       maximum number of sg devices from 256 to 8192
     - use seq_file interface for /proc/scsi/sg/*
       pseudo files
     - sysfs symlinks between the sysfs scsi device and the
       corresponding sg cdev node (and vice versa)

An edited "tree" output showing an example of these symlinks
was included in my previous post.

As noted in another thread, st (and osst) may need "cdevs"
and sysfs symlinks so SCSI tape devices have sysfs visibility
in lk 2.6 .

Also if both st and sg had sysfs visibility then Patrick
Mansfield's scsi_id program could be made to work for tape
drives (enclosures, tape robots, etc) by following these
symlinks.

drivers/scsi/sg.c

@@ -18,8 +18,7 @@
  *
  */
 #include <linux/config.h>
-static char *sg_version_str = "3.5.29 [20030529]";
-static int sg_version_num = 30529;	/* 2 digits for each component */
+static int sg_version_num = 30530;	/* 2 digits for each component */
 /*
  *  D. P. Gilbert (dgilbert@interlog.com, dougg@triode.net.au), notes:
  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
@@ -56,6 +55,8 @@ static int sg_version_num = 30529;	/* 2 digits for each component */
 #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 <asm/io.h>
 #include <asm/uaccess.h>
@@ -72,6 +73,8 @@ static int sg_version_num = 30529;	/* 2 digits for each component */
 
 #ifdef CONFIG_SCSI_PROC_FS
 #include <linux/proc_fs.h>
+static char *sg_version_str = "3.5.30 [20031010]";
+
 static int sg_proc_init(void);
 static void sg_proc_cleanup(void);
 #endif
@@ -83,7 +86,7 @@ static void sg_proc_cleanup(void);
 #define SG_ALLOW_DIO_DEF 0
 #define SG_ALLOW_DIO_CODE /* compile out by commenting this define */
 
-#define SG_MAX_DEVS_MASK (256 - 1)
+#define SG_MAX_DEVS 8192
 
 /*
  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
@@ -182,6 +185,7 @@ typedef struct sg_device { /* holds the state of each scsi generic device */
 	volatile char exclude;	/* opened for exclusive access */
 	char sgdebug;		/* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 	struct gendisk *disk;
+	struct cdev * cdev;	/* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 } Sg_device;
 
 static int sg_fasync(int fd, struct file *filp, int mode);
@@ -219,7 +223,6 @@ static int sg_ms_to_jif(unsigned int msecs);
 static inline unsigned sg_jif_to_ms(int jifs);
 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 void sg_unmap_and(Sg_scatter_hold * schp, int free_also);
 static Sg_device *sg_get_dev(int dev);
 static inline unsigned char *sg_scatg2virt(const struct scatterlist *sclp);
 #ifdef CONFIG_SCSI_PROC_FS
@@ -1324,18 +1327,22 @@ static struct file_operations sg_fops = {
 };
 
 static int
-sg_add(struct class_device *cdev)
+sg_add(struct class_device *cl_dev)
 {
-	struct scsi_device *scsidp = to_scsi_device(cdev->dev);
+	struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
 	struct gendisk *disk;
 	Sg_device *sdp = NULL;
 	unsigned long iflags;
+	struct cdev * cdev = NULL;
 	int k, error;
 
 	disk = alloc_disk(1);
 	if (!disk)
 		return -ENOMEM;
 
+	cdev = cdev_alloc();
+	if (! cdev)
+		return -ENOMEM;
 	write_lock_irqsave(&sg_dev_arr_lock, iflags);
 	if (sg_nr_dev >= sg_dev_max) {	/* try to resize */
 		Sg_device **tmp_da;
@@ -1363,13 +1370,13 @@ sg_add(struct class_device *cdev)
 	for (k = 0; k < sg_dev_max; k++)
 		if (!sg_dev_arr[k])
 			break;
-	if (k > SG_MAX_DEVS_MASK) {
+	if (k >= SG_MAX_DEVS) {
 		write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
 		printk(KERN_WARNING
 		       "Unable to attach sg device <%d, %d, %d, %d>"
-		       " type=%d, minor number exceed %d\n",
+		       " type=%d, minor number exceeds %d\n",
 		       scsidp->host->host_no, scsidp->channel, scsidp->id,
-		       scsidp->lun, scsidp->type, SG_MAX_DEVS_MASK);
+		       scsidp->lun, scsidp->type, SG_MAX_DEVS - 1);
 		if (NULL != sdp)
 			vfree((char *) sdp);
 		error = -ENODEV;
@@ -1395,15 +1402,14 @@ sg_add(struct class_device *cdev)
 	SCSI_LOG_TIMEOUT(3, printk("sg_attach: dev=%d \n", k));
 	memset(sdp, 0, sizeof(*sdp));
 	sprintf(disk->disk_name, "sg%d", k);
+	strncpy(cdev->kobj.name, disk->disk_name, KOBJ_NAME_LEN);
+	cdev->owner = THIS_MODULE;
+	cdev->ops = &sg_fops;
 	disk->major = SCSI_GENERIC_MAJOR;
 	disk->first_minor = k;
 	sdp->disk = disk;
 	sdp->device = scsidp;
 	init_waitqueue_head(&sdp->o_excl_wait);
-	sdp->headfp = NULL;
-	sdp->exclude = 0;
-	sdp->sgdebug = 0;
-	sdp->detached = 0;
 	sdp->sg_tablesize = scsidp->host ? scsidp->host->sg_tablesize : 0;
 
 	sg_nr_dev++;
@@ -1413,6 +1419,22 @@ sg_add(struct class_device *cdev)
 	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;
+	}
+	sdp->cdev = cdev;
+	error = sysfs_create_link(&cdev->kobj, &scsidp->sdev_gendev.kobj, 
+				  "device");
+	if (error)
+		printk(KERN_ERR "sg_attach: unable to make symlink 'device'"
+		       " for sg%d\n", k);
+	error = sysfs_create_link(&scsidp->sdev_gendev.kobj, &cdev->kobj, 
+				  "generic");
+	if (error)
+		printk(KERN_ERR "sg_attach: unable to make symlink 'generic'"
+		       " back to sg%d\n", k);
 
 	printk(KERN_NOTICE
 	       "Attached scsi generic sg%d at scsi%d, channel"
@@ -1424,13 +1446,15 @@ sg_add(struct class_device *cdev)
 
 out:
 	put_disk(disk);
+	if (cdev)
+		kobject_put(&cdev->kobj);
 	return error;
 }
 
 static void
-sg_remove(struct class_device *cdev)
+sg_remove(struct class_device *cl_dev)
 {
-	struct scsi_device *scsidp = to_scsi_device(cdev->dev);
+	struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
 	Sg_device *sdp = NULL;
 	unsigned long iflags;
 	Sg_fd *sfp;
@@ -1480,6 +1504,10 @@ sg_remove(struct class_device *cdev)
 	write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
 
 	if (sdp) {
+		sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
+		sysfs_remove_link(&sdp->cdev->kobj, "device");
+		cdev_del(sdp->cdev);
+		sdp->cdev = NULL;
 		devfs_remove("%s/generic", scsidp->devfs_name);
 		put_disk(sdp->disk);
 		sdp->disk = NULL;
@@ -1512,12 +1540,14 @@ init_sg(void)
 	if (def_reserved_size >= 0)
 		sg_big_buff = def_reserved_size;
 
-	rc = register_chrdev(SCSI_GENERIC_MAJOR, "sg", &sg_fops);
+	rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), 
+				    SG_MAX_DEVS, "sg");
 	if (rc)
 		return rc;
 	rc = scsi_register_interface(&sg_interface);
 	if (rc) {
-		unregister_chrdev(SCSI_GENERIC_MAJOR, "sg");
+		unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
+				         SG_MAX_DEVS);
 		return rc;
 	}
 #ifdef CONFIG_SCSI_PROC_FS
@@ -1533,7 +1563,8 @@ exit_sg(void)
 	sg_proc_cleanup();
 #endif				/* CONFIG_SCSI_PROC_FS */
 	scsi_unregister_interface(&sg_interface);
-	unregister_chrdev(SCSI_GENERIC_MAJOR, "sg");
+	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
+				 SG_MAX_DEVS);
 	if (sg_dev_arr != NULL) {
 		vfree((char *) sg_dev_arr);
 		sg_dev_arr = NULL;
@@ -1581,7 +1612,6 @@ sg_finish_rem_req(Sg_request * srp)
 	Sg_scatter_hold *req_schp = &srp->data;
 
 	SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
-	// sg_unmap_and(&srp->data, 1);
 	if (srp->res_used)
 		sg_unlink_reserve(sfp, srp);
 	else
@@ -2589,78 +2619,99 @@ static struct proc_dir_entry *sg_proc_sgp = NULL;
 
 static char sg_proc_sg_dirname[] = "scsi/sg";
 
-static int sg_proc_adio_read(char *buffer, char **start, off_t offset,
-			     int size, int *eof, void *data);
-static int sg_proc_adio_info(char *buffer, int *len, off_t * begin,
-			     off_t offset, int size);
-static int sg_proc_adio_write(struct file *filp, const char *buffer,
-			      unsigned long count, void *data);
-static int sg_proc_dressz_read(char *buffer, char **start, off_t offset,
-			       int size, int *eof, void *data);
-static int sg_proc_dressz_info(char *buffer, int *len, off_t * begin,
-			       off_t offset, int size);
-static int sg_proc_dressz_write(struct file *filp, const char *buffer,
-				unsigned long count, void *data);
-static int sg_proc_debug_read(char *buffer, char **start, off_t offset,
-			      int size, int *eof, void *data);
-static int sg_proc_debug_info(char *buffer, int *len, off_t * begin,
-			      off_t offset, int size);
-static int sg_proc_dev_read(char *buffer, char **start, off_t offset,
-			    int size, int *eof, void *data);
-static int sg_proc_dev_info(char *buffer, int *len, off_t * begin,
-			    off_t offset, int size);
-static int sg_proc_devhdr_read(char *buffer, char **start, off_t offset,
-			       int size, int *eof, void *data);
-static int sg_proc_devhdr_info(char *buffer, int *len, off_t * begin,
-			       off_t offset, int size);
-static int sg_proc_devstrs_read(char *buffer, char **start, off_t offset,
-				int size, int *eof, void *data);
-static int sg_proc_devstrs_info(char *buffer, int *len, off_t * begin,
-				off_t offset, int size);
-static int sg_proc_version_read(char *buffer, char **start, off_t offset,
-				int size, int *eof, void *data);
-static int sg_proc_version_info(char *buffer, int *len, off_t * begin,
-				off_t offset, int size);
+static int sg_proc_seq_show_int(struct seq_file *s, void *v);
+
+static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
+static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
+			          size_t count, loff_t *off);
+static struct file_operations adio_fops = {
+	/* .owner, .read and .llseek added in sg_proc_init() */
+	.open = sg_proc_single_open_adio,
+	.write = sg_proc_write_adio,
+	.release = single_release,
+};
+
+static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
+static ssize_t sg_proc_write_dressz(struct file *filp, 
+		const char __user *buffer, size_t count, loff_t *off);
+static struct file_operations dressz_fops = {
+	.open = sg_proc_single_open_dressz,
+	.write = sg_proc_write_dressz,
+	.release = single_release,
+};
+
+static int sg_proc_seq_show_version(struct seq_file *s, void *v);
+static int sg_proc_single_open_version(struct inode *inode, struct file *file);
+static struct file_operations version_fops = {
+	.open = sg_proc_single_open_version,
+	.release = single_release,
+};
+
+static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
+static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
+static struct file_operations devhdr_fops = {
+	.open = sg_proc_single_open_devhdr,
+	.release = single_release,
+};
+
+static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
+static int sg_proc_open_dev(struct inode *inode, struct file *file);
+static void * dev_seq_start(struct seq_file *s, loff_t *pos);
+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);
+static struct file_operations dev_fops = {
+	.open = sg_proc_open_dev,
+	.release = seq_release,
+};
+static struct seq_operations dev_seq_ops = {
+	.start = dev_seq_start,
+	.next  = dev_seq_next,
+	.stop  = dev_seq_stop,
+	.show  = sg_proc_seq_show_dev,
+};
+
+static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
+static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
+static struct file_operations devstrs_fops = {
+	.open = sg_proc_open_devstrs,
+	.release = seq_release,
+};
+static struct seq_operations devstrs_seq_ops = {
+	.start = dev_seq_start,
+	.next  = dev_seq_next,
+	.stop  = dev_seq_stop,
+	.show  = sg_proc_seq_show_devstrs,
+};
+
+static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
+static int sg_proc_open_debug(struct inode *inode, struct file *file);
+static struct file_operations debug_fops = {
+	.open = sg_proc_open_debug,
+	.release = seq_release,
+};
+static struct seq_operations debug_seq_ops = {
+	.start = dev_seq_start,
+	.next  = dev_seq_next,
+	.stop  = dev_seq_stop,
+	.show  = sg_proc_seq_show_debug,
+};
+
 
 struct sg_proc_leaf {
 	const char * name;
-	read_proc_t * rf;
-	write_proc_t * wf;
+	struct file_operations * fops;
 };
 
 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
-	{"allow_dio", sg_proc_adio_read, sg_proc_adio_write},
-	{"def_reserved_size", sg_proc_dressz_read, sg_proc_dressz_write},
-	{"debug", sg_proc_debug_read, NULL},
-	{"devices", sg_proc_dev_read, NULL},
-	{"device_hdr", sg_proc_devhdr_read, NULL},
-	{"device_strs", sg_proc_devstrs_read, NULL},
-	{"version", sg_proc_version_read, NULL}
+	{"allow_dio", &adio_fops},
+	{"debug", &debug_fops},
+	{"def_reserved_size", &dressz_fops},
+	{"device_hdr", &devhdr_fops},
+	{"devices", &dev_fops},
+	{"device_strs", &devstrs_fops},
+	{"version", &version_fops}
 };
 
-#define PRINT_PROC(fmt,args...)                                 \
-    do {                                                        \
-	*len += sprintf(buffer + *len, fmt, ##args);            \
-	if (*begin + *len > offset + size)                      \
-	    return 0;                                           \
-	if (*begin + *len < offset) {                           \
-	    *begin += *len;                                     \
-	    *len = 0;                                           \
-	}                                                       \
-    } while(0)
-
-#define SG_PROC_READ_FN(infofp)                                 \
-    do {                                                        \
-	int len = 0;                                            \
-	off_t begin = 0;                                        \
-	*eof = infofp(buffer, &len, &begin, offset, size);      \
-	if (offset >= (begin + len))                            \
-	    return 0;                                           \
-	*start = buffer + offset - begin;			\
-	return (size < (begin + len - offset)) ?                \
-				size : begin + len - offset;    \
-    } while(0)
-
 static int
 sg_proc_init(void)
 {
@@ -2676,12 +2727,13 @@ sg_proc_init(void)
 		return 1;
 	for (k = 0; k < num_leaves; ++k) {
 		leaf = &sg_proc_leaf_arr[k];
-		mask = leaf->wf ? S_IRUGO | S_IWUSR : S_IRUGO;
+		mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
 		pdep = create_proc_entry(leaf->name, mask, sg_proc_sgp);
 		if (pdep) {
-			pdep->read_proc = leaf->rf;
-			if (leaf->wf)
-				pdep->write_proc = leaf->wf;
+			leaf->fops->owner = THIS_MODULE,
+			leaf->fops->read = seq_read,
+			leaf->fops->llseek = seq_lseek,
+			pdep->proc_fops = leaf->fops;
 		}
 	}
 	return 0;
@@ -2701,23 +2753,21 @@ sg_proc_cleanup(void)
 	remove_proc_entry(sg_proc_sg_dirname, NULL);
 }
 
-static int
-sg_proc_adio_read(char *buffer, char **start, off_t offset,
-		  int size, int *eof, void *data)
+
+static int sg_proc_seq_show_int(struct seq_file *s, void *v)
 {
-	SG_PROC_READ_FN(sg_proc_adio_info);
+	seq_printf(s, "%d\n", *((int *)s->private));
+	return 0;
 }
 
-static int
-sg_proc_adio_info(char *buffer, int *len, off_t * begin, off_t offset, int size)
+static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
 {
-	PRINT_PROC("%d\n", sg_allow_dio);
-	return 1;
+	return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
 }
 
-static int
-sg_proc_adio_write(struct file *filp, const char *buffer,
-		   unsigned long count, void *data)
+static ssize_t 
+sg_proc_write_adio(struct file *filp, const char __user *buffer,
+		   size_t count, loff_t *off)
 {
 	int num;
 	char buff[11];
@@ -2732,24 +2782,14 @@ sg_proc_adio_write(struct file *filp, const char *buffer,
 	return count;
 }
 
-static int
-sg_proc_dressz_read(char *buffer, char **start, off_t offset,
-		    int size, int *eof, void *data)
-{
-	SG_PROC_READ_FN(sg_proc_dressz_info);
-}
-
-static int
-sg_proc_dressz_info(char *buffer, int *len, off_t * begin,
-		    off_t offset, int size)
+static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
 {
-	PRINT_PROC("%d\n", sg_big_buff);
-	return 1;
+	return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
 }
 
-static int
-sg_proc_dressz_write(struct file *filp, const char *buffer,
-		     unsigned long count, void *data)
+static ssize_t 
+sg_proc_write_dressz(struct file *filp, const char __user *buffer,
+		     size_t count, loff_t *off)
 {
 	int num;
 	unsigned long k = ULONG_MAX;
@@ -2769,15 +2809,111 @@ sg_proc_dressz_write(struct file *filp, const char *buffer,
 	return -ERANGE;
 }
 
-static int
-sg_proc_debug_read(char *buffer, char **start, off_t offset,
-		   int size, int *eof, void *data)
+static int sg_proc_seq_show_version(struct seq_file *s, void *v)
+{
+	seq_printf(s, "%d\t%s\n", sg_version_num, sg_version_str);
+	return 0;
+}
+
+static int sg_proc_single_open_version(struct inode *inode, struct file *file)
+{
+	return single_open(file, sg_proc_seq_show_version, NULL);
+}
+
+static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
+{
+	seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
+		   "online\n");
+	return 0;
+}
+
+static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
+{
+	return single_open(file, sg_proc_seq_show_devhdr, NULL);
+}
+
+struct sg_proc_deviter {
+	loff_t	index;
+	size_t	max;
+};
+
+static void * dev_seq_start(struct seq_file *s, loff_t *pos)
+{
+	struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
+
+	if (! it)
+		return NULL;
+	if (NULL == sg_dev_arr)
+		goto err1;
+	it->index = *pos;
+	it->max = sg_last_dev();
+	if (it->index >= it->max)
+		goto err1;
+	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;
+
+	*pos = ++it->index;
+	return (it->index < it->max) ? it : NULL;
+}
+
+static void dev_seq_stop(struct seq_file *s, void *v)
+{
+	kfree (v);
+}
+
+static int sg_proc_open_dev(struct inode *inode, struct file *file)
+{
+        return seq_open(file, &dev_seq_ops);
+}
+
+static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
+{
+	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
+	Sg_device *sdp;
+	struct scsi_device *scsidp;
+
+	sdp = it ? sg_get_dev(it->index) : NULL;
+	if (sdp && (scsidp = sdp->device) && (!sdp->detached))
+		seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
+			      scsidp->host->host_no, scsidp->channel,
+			      scsidp->id, scsidp->lun, (int) scsidp->type,
+			      (int) atomic_read(&scsidp->access_count),
+			      (int) scsidp->queue_depth,
+			      (int) scsidp->device_busy,
+			      (int) scsidp->online);
+	else
+		seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
+	return 0;
+}
+
+static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
 {
-	SG_PROC_READ_FN(sg_proc_debug_info);
+        return seq_open(file, &devstrs_seq_ops);
 }
 
-static int sg_proc_debug_helper(char *buffer, int *len, off_t * begin,
-				off_t offset, int size, Sg_device * sdp)
+static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
+{
+	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
+	Sg_device *sdp;
+	struct scsi_device *scsidp;
+
+	sdp = it ? sg_get_dev(it->index) : NULL;
+	if (sdp && (scsidp = sdp->device) && (!sdp->detached))
+		seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
+			   scsidp->vendor, scsidp->model, scsidp->rev);
+	else
+		seq_printf(s, "<no active device>\n");
+	return 0;
+}
+
+static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
 {
 	int k, m, new_interface, blen, usg;
 	Sg_request *srp;
@@ -2786,13 +2922,13 @@ static int sg_proc_debug_helper(char *buffer, int *len, off_t * begin,
 	const char * cp;
 
 	for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
-		PRINT_PROC("   FD(%d): timeout=%dms bufflen=%d "
+		seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
 			   "(res)sgat=%d low_dma=%d\n", k + 1,
 			   sg_jif_to_ms(fp->timeout),
 			   fp->reserve.bufflen,
 			   (int) fp->reserve.k_use_sg,
 			   (int) fp->low_dma);
-		PRINT_PROC("   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
+		seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
 			   (int) fp->cmd_q, (int) fp->force_packid,
 			   (int) fp->keep_orphan, (int) fp->closed);
 		for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
@@ -2810,165 +2946,75 @@ static int sg_proc_debug_helper(char *buffer, int *len, off_t * begin,
 				else
 					cp = "     ";
 			}
-			PRINT_PROC(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;
-			PRINT_PROC(srp->done ? 
+			seq_printf(s, srp->done ? 
 				   ((1 == srp->done) ?  "rcv:" : "fin:")
 				   : (srp->my_cmdp ? "act:" : "prior:"));
-			PRINT_PROC(" id=%d blen=%d",
+			seq_printf(s, " id=%d blen=%d",
 				   srp->header.pack_id, blen);
 			if (srp->done)
-				PRINT_PROC(" dur=%d", hp->duration);
+				seq_printf(s, " dur=%d", hp->duration);
 			else
-				PRINT_PROC(" t_o/elap=%d/%d",
+				seq_printf(s, " t_o/elap=%d/%d",
 				  new_interface ? hp->timeout : sg_jif_to_ms(fp->timeout),
 				  sg_jif_to_ms(hp->duration ? (jiffies - hp->duration) : 0));
-			PRINT_PROC("ms sgat=%d op=0x%02x\n", usg,
+			seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
 				   (int) srp->data.cmd_opcode);
 		}
 		if (0 == m)
-			PRINT_PROC("     No requests active\n");
+			seq_printf(s, "     No requests active\n");
 	}
-	return 1;
 }
 
-static int
-sg_proc_debug_info(char *buffer, int *len, off_t * begin,
-		   off_t offset, int size)
+static int sg_proc_open_debug(struct inode *inode, struct file *file)
+{
+        return seq_open(file, &debug_seq_ops);
+}
+
+static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
 {
+	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
 	Sg_device *sdp;
-	int j, max_dev;
 
-	if (NULL == sg_dev_arr) {
-		PRINT_PROC("sg_dev_arr NULL, driver not initialized\n");
-		return 1;
+	if (it && (0 == it->index)) {
+		seq_printf(s, "dev_max(currently)=%d max_active_device=%d "
+			   "(origin 1)\n", sg_dev_max, (int)it->max);
+		seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
 	}
-	max_dev = sg_last_dev();
-	PRINT_PROC("dev_max(currently)=%d max_active_device=%d (origin 1)\n",
-		   sg_dev_max, max_dev);
-	PRINT_PROC(" def_reserved_size=%d\n", sg_big_buff);
-	for (j = 0; j < max_dev; ++j) {
-		if ((sdp = sg_get_dev(j))) {
+	sdp = it ? sg_get_dev(it->index) : NULL;
+	if (sdp) {
 		struct scsi_device *scsidp = sdp->device;
 
 		if (NULL == scsidp) {
-				PRINT_PROC("device %d detached ??\n", j);
-				continue;
+			seq_printf(s, "device %d detached ??\n", 
+				   (int)it->index);
+			return 0;
 		}
 
 		if (sg_get_nth_sfp(sdp, 0)) {
-				PRINT_PROC(" >>> device=%s ",
+			seq_printf(s, " >>> device=%s ",
 				sdp->disk->disk_name);
 			if (sdp->detached)
-					PRINT_PROC("detached pending close ");
+				seq_printf(s, "detached pending close ");
 			else
-					PRINT_PROC
-					    ("scsi%d chan=%d id=%d lun=%d   em=%d",
+				seq_printf
+				    (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
 				     scsidp->host->host_no,
 				     scsidp->channel, scsidp->id,
 				     scsidp->lun,
 				     scsidp->host->hostt->emulated);
-				PRINT_PROC(" sg_tablesize=%d excl=%d\n",
+			seq_printf(s, " sg_tablesize=%d excl=%d\n",
 				   sdp->sg_tablesize, sdp->exclude);
 		}
-			if (0 == sg_proc_debug_helper(buffer, len, begin,
-						      offset, size, sdp))
-				return 0;
-		}
+		sg_proc_debug_helper(s, sdp);
 	}
-	return 1;
-}
-
-static int
-sg_proc_dev_read(char *buffer, char **start, off_t offset,
-		 int size, int *eof, void *data)
-{
-	SG_PROC_READ_FN(sg_proc_dev_info);
-}
-
-static int
-sg_proc_dev_info(char *buffer, int *len, off_t * begin, off_t offset, int size)
-{
-	Sg_device *sdp;
-	int j, max_dev;
-	struct scsi_device *scsidp;
-
-	max_dev = sg_last_dev();
-	for (j = 0; j < max_dev; ++j) {
-		sdp = sg_get_dev(j);
-		if (sdp && (scsidp = sdp->device) && (!sdp->detached))
-			PRINT_PROC("%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
-				   scsidp->host->host_no, scsidp->channel,
-				   scsidp->id, scsidp->lun, (int) scsidp->type,
-				   (int) atomic_read(&scsidp->access_count),
-				   (int) scsidp->queue_depth,
-				   (int) scsidp->device_busy,
-				   (int) scsidp->online);
-		else
-			PRINT_PROC("-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
-	}
-	return 1;
-}
-
-static int
-sg_proc_devhdr_read(char *buffer, char **start, off_t offset,
-		    int size, int *eof, void *data)
-{
-	SG_PROC_READ_FN(sg_proc_devhdr_info);
-}
-
-static int
-sg_proc_devhdr_info(char *buffer, int *len, off_t * begin,
-		    off_t offset, int size)
-{
-	PRINT_PROC("host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
-	return 1;
-}
-
-static int
-sg_proc_devstrs_read(char *buffer, char **start, off_t offset,
-		     int size, int *eof, void *data)
-{
-	SG_PROC_READ_FN(sg_proc_devstrs_info);
-}
-
-static int
-sg_proc_devstrs_info(char *buffer, int *len, off_t * begin,
-		     off_t offset, int size)
-{
-	Sg_device *sdp;
-	int j, max_dev;
-	struct scsi_device *scsidp;
-
-	max_dev = sg_last_dev();
-	for (j = 0; j < max_dev; ++j) {
-		sdp = sg_get_dev(j);
-		if (sdp && (scsidp = sdp->device) && (!sdp->detached))
-			PRINT_PROC("%8.8s\t%16.16s\t%4.4s\n",
-				   scsidp->vendor, scsidp->model, scsidp->rev);
-		else
-			PRINT_PROC("<no active device>\n");
-	}
-	return 1;
-}
-
-static int
-sg_proc_version_read(char *buffer, char **start, off_t offset,
-		     int size, int *eof, void *data)
-{
-	SG_PROC_READ_FN(sg_proc_version_info);
+	return 0;
 }
 
-static int
-sg_proc_version_info(char *buffer, int *len, off_t * begin,
-		     off_t offset, int size)
-{
-	PRINT_PROC("%d\t%s\n", sg_version_num, sg_version_str);
-	return 1;
-}
 #endif				/* CONFIG_SCSI_PROC_FS */
 
 module_init(init_sg);