1 files changed, 112 insertions, 141 deletions

diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index fdc6618c1f61..f6f5fc7d0cee 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -43,6 +43,7 @@ static int sg_version_num = 30534;	/* 2 digits for each component */
 #include <linux/poll.h>
 #include <linux/moduleparam.h>
 #include <linux/cdev.h>
+#include <linux/idr.h>
 #include <linux/seq_file.h>
 #include <linux/blkdev.h>
 #include <linux/delay.h>
@@ -99,12 +100,11 @@ static int scatter_elem_sz_prev = SG_SCATTER_SZ;
 #define SG_SECTOR_SZ 512
 #define SG_SECTOR_MSK (SG_SECTOR_SZ - 1)
 
-#define SG_DEV_ARR_LUMP 32	/* amount to over allocate sg_dev_arr by */
-
 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
+static DEFINE_IDR(sg_index_idr);
+static DEFINE_RWLOCK(sg_index_lock);	/* Also used to lock
 							   file descriptor list for device */
 
 static struct class_interface sg_interface = {
@@ -162,6 +162,7 @@ typedef struct sg_device { /* holds the state of each scsi generic device */
 	struct scsi_device *device;
 	wait_queue_head_t o_excl_wait;	/* queue open() when O_EXCL in use */
 	int sg_tablesize;	/* adapter's max scatter-gather table size */
+	u32 index;		/* device index number */
 	Sg_fd *headfp;		/* first open fd belonging to this device */
 	volatile char detached;	/* 0->attached, 1->detached pending removal */
 	volatile char exclude;	/* opened for exclusive access */
@@ -209,10 +210,6 @@ static Sg_device *sg_get_dev(int dev);
 static int sg_last_dev(void);
 #endif
 
-static Sg_device **sg_dev_arr = NULL;
-static int sg_dev_max;
-static int sg_nr_dev;
-
 #define SZ_SG_HEADER sizeof(struct sg_header)
 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
@@ -1331,40 +1328,35 @@ static struct class *sg_sysfs_class;
 
 static int sg_sysfs_valid = 0;
 
-static int sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
+static Sg_device *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;
+	int error;
+	u32 k;
 
 	sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
 	if (!sdp) {
 		printk(KERN_WARNING "kmalloc Sg_device failure\n");
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
+	}
+	error = -ENOMEM;
+	if (!idr_pre_get(&sg_index_idr, GFP_KERNEL)) {
+		printk(KERN_WARNING "idr expansion Sg_device failure\n");
+		goto out;
 	}
 
-	write_lock_irqsave(&sg_dev_arr_lock, iflags);
-	if (unlikely(sg_nr_dev >= sg_dev_max)) {	/* try to resize */
-		Sg_device **tmp_da;
-		int tmp_dev_max = sg_nr_dev + SG_DEV_ARR_LUMP;
-		write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
-
-		tmp_da = kzalloc(tmp_dev_max * sizeof(Sg_device *), GFP_KERNEL);
-		if (unlikely(!tmp_da))
-			goto expand_failed;
+	write_lock_irqsave(&sg_index_lock, iflags);
+	error = idr_get_new(&sg_index_idr, sdp, &k);
+	write_unlock_irqrestore(&sg_index_lock, iflags);
 
-		write_lock_irqsave(&sg_dev_arr_lock, iflags);
-		memcpy(tmp_da, sg_dev_arr, sg_dev_max * sizeof(Sg_device *));
-		old_sg_dev_arr = sg_dev_arr;
-		sg_dev_arr = tmp_da;
-		sg_dev_max = tmp_dev_max;
+	if (error) {
+		printk(KERN_WARNING "idr allocation Sg_device failure: %d\n",
+		       error);
+		goto out;
 	}
 
-	for (k = 0; k < sg_dev_max; k++)
-		if (!sg_dev_arr[k])
-			break;
 	if (unlikely(k >= SG_MAX_DEVS))
 		goto overflow;
 
@@ -1375,25 +1367,17 @@ static int sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
 	sdp->device = scsidp;
 	init_waitqueue_head(&sdp->o_excl_wait);
 	sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments);
+	sdp->index = k;
 
-	sg_nr_dev++;
-	sg_dev_arr[k] = sdp;
-	write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
-	error = k;
-
+	error = 0;
  out:
-	if (error < 0)
+	if (error) {
 		kfree(sdp);
-	kfree(old_sg_dev_arr);
-	return error;
-
- expand_failed:
-	printk(KERN_WARNING "sg_alloc: device array cannot be resized\n");
-	error = -ENOMEM;
-	goto out;
+		return ERR_PTR(error);
+	}
+	return sdp;
 
  overflow:
-	write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
 	sdev_printk(KERN_WARNING, scsidp,
 		    "Unable to attach sg device type=%d, minor "
 		    "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
@@ -1408,7 +1392,7 @@ sg_add(struct class_device *cl_dev, struct class_interface *cl_intf)
 	struct gendisk *disk;
 	Sg_device *sdp = NULL;
 	struct cdev * cdev = NULL;
-	int error, k;
+	int error;
 	unsigned long iflags;
 
 	disk = alloc_disk(1);
@@ -1427,15 +1411,15 @@ sg_add(struct class_device *cl_dev, struct class_interface *cl_intf)
 	cdev->owner = THIS_MODULE;
 	cdev->ops = &sg_fops;
 
-	error = sg_alloc(disk, scsidp);
-	if (error < 0) {
+	sdp = sg_alloc(disk, scsidp);
+	if (IS_ERR(sdp)) {
 		printk(KERN_WARNING "sg_alloc failed\n");
+		error = PTR_ERR(sdp);
 		goto out;
 	}
-	k = error;
-	sdp = sg_dev_arr[k];
 
-	error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, k), 1);
+	class_set_devdata(cl_dev, sdp);
+	error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
 	if (error)
 		goto cdev_add_err;
 
@@ -1444,8 +1428,8 @@ sg_add(struct class_device *cl_dev, struct class_interface *cl_intf)
 		struct class_device * sg_class_member;
 
 		sg_class_member = class_device_create(sg_sysfs_class, NULL,
-				MKDEV(SCSI_GENERIC_MAJOR, k), 
-				cl_dev->dev, "%s", 
+				MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
+				cl_dev->dev, "%s",
 				disk->disk_name);
 		if (IS_ERR(sg_class_member))
 			printk(KERN_WARNING "sg_add: "
@@ -1455,21 +1439,21 @@ sg_add(struct class_device *cl_dev, struct class_interface *cl_intf)
 					  &sg_class_member->kobj, "generic");
 		if (error)
 			printk(KERN_ERR "sg_add: unable to make symlink "
-					"'generic' back to sg%d\n", k);
+					"'generic' back to sg%d\n", sdp->index);
 	} else
-		printk(KERN_WARNING "sg_add: sg_sys INvalid\n");
+		printk(KERN_WARNING "sg_add: sg_sys Invalid\n");
 
 	sdev_printk(KERN_NOTICE, scsidp,
-		    "Attached scsi generic sg%d type %d\n", k,scsidp->type);
+		    "Attached scsi generic sg%d type %d\n", sdp->index,
+		    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);
+	write_lock_irqsave(&sg_index_lock, iflags);
+	idr_remove(&sg_index_idr, sdp->index);
+	write_unlock_irqrestore(&sg_index_lock, iflags);
+	kfree(sdp);
 
 out:
 	put_disk(disk);
@@ -1482,64 +1466,56 @@ static void
 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;
+	Sg_device *sdp = class_get_devdata(cl_dev);
 	unsigned long iflags;
 	Sg_fd *sfp;
 	Sg_fd *tsfp;
 	Sg_request *srp;
 	Sg_request *tsrp;
-	int k, delay;
+	int delay;
 
-	if (NULL == sg_dev_arr)
+	if (!sdp)
 		return;
+
 	delay = 0;
-	write_lock_irqsave(&sg_dev_arr_lock, iflags);
-	for (k = 0; k < sg_dev_max; k++) {
-		sdp = sg_dev_arr[k];
-		if ((NULL == sdp) || (sdp->device != scsidp))
-			continue;	/* dirty but lowers nesting */
-		if (sdp->headfp) {
-			sdp->detached = 1;
-			for (sfp = sdp->headfp; sfp; sfp = tsfp) {
-				tsfp = sfp->nextfp;
-				for (srp = sfp->headrp; srp; srp = tsrp) {
-					tsrp = srp->nextrp;
-					if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
-						sg_finish_rem_req(srp);
-				}
-				if (sfp->closed) {
-					scsi_device_put(sdp->device);
-					__sg_remove_sfp(sdp, sfp);
-				} else {
-					delay = 1;
-					wake_up_interruptible(&sfp->read_wait);
-					kill_fasync(&sfp->async_qp, SIGPOLL,
-						    POLL_HUP);
-				}
+	write_lock_irqsave(&sg_index_lock, iflags);
+	if (sdp->headfp) {
+		sdp->detached = 1;
+		for (sfp = sdp->headfp; sfp; sfp = tsfp) {
+			tsfp = sfp->nextfp;
+			for (srp = sfp->headrp; srp; srp = tsrp) {
+				tsrp = srp->nextrp;
+				if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
+					sg_finish_rem_req(srp);
 			}
-			SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d, dirty\n", k));
-			if (NULL == sdp->headfp) {
-				sg_dev_arr[k] = NULL;
+			if (sfp->closed) {
+				scsi_device_put(sdp->device);
+				__sg_remove_sfp(sdp, sfp);
+			} else {
+				delay = 1;
+				wake_up_interruptible(&sfp->read_wait);
+				kill_fasync(&sfp->async_qp, SIGPOLL,
+					    POLL_HUP);
 			}
-		} else {	/* nothing active, simple case */
-			SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d\n", k));
-			sg_dev_arr[k] = NULL;
 		}
-		sg_nr_dev--;
-		break;
-	}
-	write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
-
-	if (sdp) {
-		sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
-		class_device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, k));
-		cdev_del(sdp->cdev);
-		sdp->cdev = NULL;
-		put_disk(sdp->disk);
-		sdp->disk = NULL;
-		if (NULL == sdp->headfp)
-			kfree((char *) sdp);
-	}
+		SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d, dirty\n", sdp->index));
+		if (NULL == sdp->headfp) {
+			idr_remove(&sg_index_idr, sdp->index);
+		}
+	} else {	/* nothing active, simple case */
+		SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d\n", sdp->index));
+		idr_remove(&sg_index_idr, sdp->index);
+	}
+	write_unlock_irqrestore(&sg_index_lock, iflags);
+
+	sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
+	class_device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
+	cdev_del(sdp->cdev);
+	sdp->cdev = NULL;
+	put_disk(sdp->disk);
+	sdp->disk = NULL;
+	if (NULL == sdp->headfp)
+		kfree(sdp);
 
 	if (delay)
 		msleep(10);	/* dirty detach so delay device destruction */
@@ -1609,9 +1585,7 @@ exit_sg(void)
 	sg_sysfs_valid = 0;
 	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
 				 SG_MAX_DEVS);
-	kfree((char *)sg_dev_arr);
-	sg_dev_arr = NULL;
-	sg_dev_max = 0;
+	idr_destroy(&sg_index_idr);
 }
 
 static int
@@ -2331,10 +2305,10 @@ sg_get_nth_sfp(Sg_device * sdp, int nth)
 	unsigned long iflags;
 	int k;
 
-	read_lock_irqsave(&sg_dev_arr_lock, iflags);
+	read_lock_irqsave(&sg_index_lock, iflags);
 	for (k = 0, resp = sdp->headfp; resp && (k < nth);
 	     ++k, resp = resp->nextfp) ;
-	read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
+	read_unlock_irqrestore(&sg_index_lock, iflags);
 	return resp;
 }
 #endif
@@ -2361,7 +2335,7 @@ sg_add_sfp(Sg_device * sdp, int dev)
 	sfp->cmd_q = SG_DEF_COMMAND_Q;
 	sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
 	sfp->parentdp = sdp;
-	write_lock_irqsave(&sg_dev_arr_lock, iflags);
+	write_lock_irqsave(&sg_index_lock, iflags);
 	if (!sdp->headfp)
 		sdp->headfp = sfp;
 	else {			/* add to tail of existing list */
@@ -2370,7 +2344,7 @@ sg_add_sfp(Sg_device * sdp, int dev)
 			pfp = pfp->nextfp;
 		pfp->nextfp = sfp;
 	}
-	write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
+	write_unlock_irqrestore(&sg_index_lock, iflags);
 	SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
 	if (unlikely(sg_big_buff != def_reserved_size))
 		sg_big_buff = def_reserved_size;
@@ -2431,22 +2405,14 @@ sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
 	if (0 == dirty) {
 		unsigned long iflags;
 
-		write_lock_irqsave(&sg_dev_arr_lock, iflags);
+		write_lock_irqsave(&sg_index_lock, iflags);
 		__sg_remove_sfp(sdp, sfp);
 		if (sdp->detached && (NULL == sdp->headfp)) {
-			int k, maxd;
-
-			maxd = sg_dev_max;
-			for (k = 0; k < maxd; ++k) {
-				if (sdp == sg_dev_arr[k])
-					break;
-			}
-			if (k < maxd)
-				sg_dev_arr[k] = NULL;
-			kfree((char *) sdp);
+			idr_remove(&sg_index_idr, sdp->index);
+			kfree(sdp);
 			res = 1;
 		}
-		write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
+		write_unlock_irqrestore(&sg_index_lock, iflags);
 	} else {
 		/* MOD_INC's to inhibit unloading sg and associated adapter driver */
 		/* only bump the access_count if we actually succeeded in
@@ -2546,16 +2512,25 @@ sg_allow_access(unsigned char opcode, char dev_type)
 
 #ifdef CONFIG_SCSI_PROC_FS
 static int
+sg_idr_max_id(int id, void *p, void *data)
+{
+	int *k = data;
+
+	if (*k < id)
+		*k = id;
+
+	return 0;
+}
+
+static int
 sg_last_dev(void)
 {
-	int k;
+	int k = 0;
 	unsigned long iflags;
 
-	read_lock_irqsave(&sg_dev_arr_lock, iflags);
-	for (k = sg_dev_max - 1; k >= 0; --k)
-		if (sg_dev_arr[k] && sg_dev_arr[k]->device)
-			break;
-	read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
+	read_lock_irqsave(&sg_index_lock, iflags);
+	idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
+	read_unlock_irqrestore(&sg_index_lock, iflags);
 	return k + 1;		/* origin 1 */
 }
 #endif
@@ -2563,15 +2538,13 @@ sg_last_dev(void)
 static Sg_device *
 sg_get_dev(int dev)
 {
-	Sg_device *sdp = NULL;
+	Sg_device *sdp;
 	unsigned long iflags;
 
-	if (sg_dev_arr && (dev >= 0)) {
-		read_lock_irqsave(&sg_dev_arr_lock, iflags);
-		if (dev < sg_dev_max)
-			sdp = sg_dev_arr[dev];
-		read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
-	}
+	read_lock_irqsave(&sg_index_lock, iflags);
+	sdp = idr_find(&sg_index_idr, dev);
+	read_unlock_irqrestore(&sg_index_lock, iflags);
+
 	return sdp;
 }
 
@@ -2805,8 +2778,6 @@ static void * dev_seq_start(struct seq_file *s, loff_t *pos)
 	if (! it)
 		return NULL;
 
-	if (NULL == sg_dev_arr)
-		return NULL;
 	it->index = *pos;
 	it->max = sg_last_dev();
 	if (it->index >= it->max)
@@ -2942,8 +2913,8 @@ static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
 	Sg_device *sdp;
 
 	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, "max_active_device=%d(origin 1)\n",
+			   (int)it->max);
 		seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
 	}
 	sdp = it ? sg_get_dev(it->index) : NULL;