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;