[PATCH] cciss: new disk register/deregister routines

This patch removes a couple of functions dealing with configuration and
replaces them with new functions.  This implementation fixes some bugs
associated with the ACUXE.  It also allows a logical volume to be removed from
the middle without deleting all volumes behind it.

If a user has 5 logical volumes and decides he wants to reconfigure volume
number 3, he can now do that without removing volumes 4 & 5 first.  This code
has been tested in our labs against all application software.

Signed-off-by: Chase Maupin <chase.maupin@hp.com>
Signed-off-by: Mike Miller <mike.miller@hp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 333 insertions, 190 deletions

diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index 8bcd6c498c60..3c6a6a21d540 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -155,15 +155,24 @@ static int cciss_ioctl(struct inode *inode, struct file *filep,
 
 static int revalidate_allvol(ctlr_info_t *host);
 static int cciss_revalidate(struct gendisk *disk);
-static int deregister_disk(struct gendisk *disk);
-static int register_new_disk(ctlr_info_t *h);
+static int rebuild_lun_table(ctlr_info_t *h, struct gendisk *del_disk);
+static int deregister_disk(struct gendisk *disk, drive_info_struct *drv, int clear_all);
 
+static void cciss_read_capacity(int ctlr, int logvol, ReadCapdata_struct *buf,
+        int withirq, unsigned int *total_size, unsigned int *block_size);
+static void cciss_geometry_inquiry(int ctlr, int logvol,
+                        int withirq, unsigned int total_size,
+                        unsigned int block_size, InquiryData_struct *inq_buff,
+                        drive_info_struct *drv);
 static void cciss_getgeometry(int cntl_num);
 
 static void start_io( ctlr_info_t *h);
 static int sendcmd( __u8 cmd, int ctlr, void *buff, size_t size,
         unsigned int use_unit_num, unsigned int log_unit, __u8 page_code,
         unsigned char *scsi3addr, int cmd_type);
+static int sendcmd_withirq(__u8 cmd, int ctlr, void *buff, size_t size,
+        unsigned int use_unit_num, unsigned int log_unit, __u8  page_code,
+        int cmd_type);
 
 #ifdef CONFIG_PROC_FS
 static int cciss_proc_get_info(char *buffer, char **start, off_t offset, 
@@ -280,7 +289,7 @@ static int cciss_proc_get_info(char *buffer, char **start, off_t offset,
         for(i=0; i<=h->highest_lun; i++) {
 
                 drv = &h->drv[i];
-                if (drv->block_size == 0)
+                if (drv->heads == 0)
                         continue;
 
                 vol_sz = drv->nr_blocks;
@@ -471,6 +480,8 @@ static int cciss_open(struct inode *inode, struct file *filep)
         if (host->busy_initializing)
                 return -EBUSY;
 
+        if (host->busy_initializing || drv->busy_configuring)
+                return -EBUSY;
         /*
          * Root is allowed to open raw volume zero even if it's not configured
          * so array config can still work. Root is also allowed to open any
@@ -814,10 +825,10 @@ static int cciss_ioctl(struct inode *inode, struct file *filep,
                 return(0);
         }
         case CCISS_DEREGDISK:
-                return deregister_disk(disk);
+                return rebuild_lun_table(host, disk);
 
         case CCISS_REGNEWD:
-                return register_new_disk(host);
+                return rebuild_lun_table(host, NULL);
 
         case CCISS_PASSTHRU:
         {
@@ -1161,48 +1172,323 @@ static int revalidate_allvol(ctlr_info_t *host)
         return 0;
 }
 
-static int deregister_disk(struct gendisk *disk)
+/* This function will check the usage_count of the drive to be updated/added.
+ * If the usage_count is zero then the drive information will be updated and
+ * the disk will be re-registered with the kernel.  If not then it will be
+ * left alone for the next reboot.  The exception to this is disk 0 which
+ * will always be left registered with the kernel since it is also the
+ * controller node.  Any changes to disk 0 will show up on the next
+ * reboot.
+*/
+static void cciss_update_drive_info(int ctlr, int drv_index)
+  {
+        ctlr_info_t *h = hba[ctlr];
+        struct gendisk *disk;
+        ReadCapdata_struct *size_buff = NULL;
+        InquiryData_struct *inq_buff = NULL;
+        unsigned int block_size;
+        unsigned int total_size;
+        unsigned long flags = 0;
+        int ret = 0;
+
+        /* if the disk already exists then deregister it before proceeding*/
+        if (h->drv[drv_index].raid_level != -1){
+                spin_lock_irqsave(CCISS_LOCK(h->ctlr), flags);
+                h->drv[drv_index].busy_configuring = 1;
+                spin_unlock_irqrestore(CCISS_LOCK(h->ctlr), flags);
+                ret = deregister_disk(h->gendisk[drv_index],
+                        &h->drv[drv_index], 0);
+                h->drv[drv_index].busy_configuring = 0;
+        }
+
+        /* If the disk is in use return */
+        if (ret)
+                return;
+
+
+        /* Get information about the disk and modify the driver sturcture */
+        size_buff = kmalloc(sizeof( ReadCapdata_struct), GFP_KERNEL);
+        if (size_buff == NULL)
+                goto mem_msg;
+        inq_buff = kmalloc(sizeof( InquiryData_struct), GFP_KERNEL);
+        if (inq_buff == NULL)
+                goto mem_msg;
+
+        cciss_read_capacity(ctlr, drv_index, size_buff, 1,
+                &total_size, &block_size);
+        cciss_geometry_inquiry(ctlr, drv_index, 1, total_size, block_size,
+                inq_buff, &h->drv[drv_index]);
+
+        ++h->num_luns;
+        disk = h->gendisk[drv_index];
+        set_capacity(disk, h->drv[drv_index].nr_blocks);
+
+
+        /* if it's the controller it's already added */
+        if (drv_index){
+                disk->queue = blk_init_queue(do_cciss_request, &h->lock);
+
+                /* Set up queue information */
+                disk->queue->backing_dev_info.ra_pages = READ_AHEAD;
+                blk_queue_bounce_limit(disk->queue, hba[ctlr]->pdev->dma_mask);
+
+                /* This is a hardware imposed limit. */
+                blk_queue_max_hw_segments(disk->queue, MAXSGENTRIES);
+
+                /* This is a limit in the driver and could be eliminated. */
+                blk_queue_max_phys_segments(disk->queue, MAXSGENTRIES);
+
+                blk_queue_max_sectors(disk->queue, 512);
+
+                disk->queue->queuedata = hba[ctlr];
+
+                blk_queue_hardsect_size(disk->queue,
+                        hba[ctlr]->drv[drv_index].block_size);
+
+                h->drv[drv_index].queue = disk->queue;
+                add_disk(disk);
+        }
+
+freeret:
+        kfree(size_buff);
+        kfree(inq_buff);
+        return;
+mem_msg:
+        printk(KERN_ERR "cciss: out of memory\n");
+        goto freeret;
+}
+
+/* This function will find the first index of the controllers drive array
+ * that has a -1 for the raid_level and will return that index.  This is
+ * where new drives will be added.  If the index to be returned is greater
+ * than the highest_lun index for the controller then highest_lun is set
+ * to this new index.  If there are no available indexes then -1 is returned.
+*/
+static int cciss_find_free_drive_index(int ctlr)
+{
+        int i;
+
+        for (i=0; i < CISS_MAX_LUN; i++){
+                if (hba[ctlr]->drv[i].raid_level == -1){
+                        if (i > hba[ctlr]->highest_lun)
+                                hba[ctlr]->highest_lun = i;
+                        return i;
+                }
+        }
+        return -1;
+}
+
+/* This function will add and remove logical drives from the Logical
+ * drive array of the controller and maintain persistancy of ordering
+ * so that mount points are preserved until the next reboot.  This allows
+ * for the removal of logical drives in the middle of the drive array
+ * without a re-ordering of those drives.
+ * INPUT
+ * h            = The controller to perform the operations on
+ * del_disk     = The disk to remove if specified.  If the value given
+ *                is NULL then no disk is removed.
+*/
+static int rebuild_lun_table(ctlr_info_t *h, struct gendisk *del_disk)
 {
+        int ctlr = h->ctlr;
+        int num_luns;
+        ReportLunData_struct *ld_buff = NULL;
+        drive_info_struct *drv = NULL;
+        int return_code;
+        int listlength = 0;
+        int i;
+        int drv_found;
+        int drv_index = 0;
+        __u32 lunid = 0;
         unsigned long flags;
+
+        /* Set busy_configuring flag for this operation */
+        spin_lock_irqsave(CCISS_LOCK(h->ctlr), flags);
+        if (h->num_luns >= CISS_MAX_LUN){
+                spin_unlock_irqrestore(CCISS_LOCK(h->ctlr), flags);
+                return -EINVAL;
+        }
+
+        if (h->busy_configuring){
+                spin_unlock_irqrestore(CCISS_LOCK(h->ctlr), flags);
+                return -EBUSY;
+        }
+        h->busy_configuring = 1;
+
+        /* if del_disk is NULL then we are being called to add a new disk
+         * and update the logical drive table.  If it is not NULL then
+         * we will check if the disk is in use or not.
+         */
+        if (del_disk != NULL){
+                drv = get_drv(del_disk);
+                drv->busy_configuring = 1;
+                spin_unlock_irqrestore(CCISS_LOCK(h->ctlr), flags);
+                return_code = deregister_disk(del_disk, drv, 1);
+                drv->busy_configuring = 0;
+                h->busy_configuring = 0;
+                return return_code;
+        } else {
+                spin_unlock_irqrestore(CCISS_LOCK(h->ctlr), flags);
+                if (!capable(CAP_SYS_RAWIO))
+                        return -EPERM;
+
+                ld_buff = kzalloc(sizeof(ReportLunData_struct), GFP_KERNEL);
+                if (ld_buff == NULL)
+                        goto mem_msg;
+
+                return_code = sendcmd_withirq(CISS_REPORT_LOG, ctlr, ld_buff,
+                                sizeof(ReportLunData_struct), 0, 0, 0,
+                                TYPE_CMD);
+
+                if (return_code == IO_OK){
+                        listlength |= (0xff & (unsigned int)(ld_buff->LUNListLength[0])) << 24;
+                        listlength |= (0xff & (unsigned int)(ld_buff->LUNListLength[1])) << 16;
+                        listlength |= (0xff & (unsigned int)(ld_buff->LUNListLength[2])) << 8;
+                        listlength |= 0xff & (unsigned int)(ld_buff->LUNListLength[3]);
+                } else{ /* reading number of logical volumes failed */
+                        printk(KERN_WARNING "cciss: report logical volume"
+                                " command failed\n");
+                        listlength = 0;
+                        goto freeret;
+                }
+
+                num_luns = listlength / 8;      /* 8 bytes per entry */
+                if (num_luns > CISS_MAX_LUN){
+                        num_luns = CISS_MAX_LUN;
+                        printk(KERN_WARNING "cciss: more luns configured"
+                                " on controller than can be handled by"
+                                " this driver.\n");
+                }
+
+                /* Compare controller drive array to drivers drive array.
+                * Check for updates in the drive information and any new drives
+                * on the controller.
+                */
+                for (i=0; i < num_luns; i++){
+                        int j;
+
+                        drv_found = 0;
+
+                        lunid = (0xff &
+                                (unsigned int)(ld_buff->LUN[i][3])) << 24;
+                        lunid |= (0xff &
+                                (unsigned int)(ld_buff->LUN[i][2])) << 16;
+                        lunid |= (0xff &
+                                (unsigned int)(ld_buff->LUN[i][1])) << 8;
+                        lunid |= 0xff &
+                                (unsigned int)(ld_buff->LUN[i][0]);
+
+                        /* Find if the LUN is already in the drive array
+                         * of the controller.  If so then update its info
+                         * if not is use.  If it does not exist then find
+                         * the first free index and add it.
+                        */
+                        for (j=0; j <= h->highest_lun; j++){
+                                if (h->drv[j].LunID == lunid){
+                                        drv_index = j;
+                                        drv_found = 1;
+                                }
+                        }
+
+                        /* check if the drive was found already in the array */
+                        if (!drv_found){
+                                drv_index = cciss_find_free_drive_index(ctlr);
+                                if (drv_index == -1)
+                                        goto freeret;
+
+                        }
+                        h->drv[drv_index].LunID = lunid;
+                        cciss_update_drive_info(ctlr, drv_index);
+                } /* end for */
+        } /* end else */
+
+freeret:
+        kfree(ld_buff);
+        h->busy_configuring = 0;
+        /* We return -1 here to tell the ACU that we have registered/updated
+         * all of the drives that we can and to keep it from calling us
+         * additional times.
+        */
+        return -1;
+mem_msg:
+        printk(KERN_ERR "cciss: out of memory\n");
+        goto freeret;
+}
+
+/* This function will deregister the disk and it's queue from the
+ * kernel.  It must be called with the controller lock held and the
+ * drv structures busy_configuring flag set.  It's parameters are:
+ *
+ * disk = This is the disk to be deregistered
+ * drv  = This is the drive_info_struct associated with the disk to be
+ *        deregistered.  It contains information about the disk used
+ *        by the driver.
+ * clear_all = This flag determines whether or not the disk information
+ *             is going to be completely cleared out and the highest_lun
+ *             reset.  Sometimes we want to clear out information about
+ *             the disk in preperation for re-adding it.  In this case
+ *             the highest_lun should be left unchanged and the LunID
+ *             should not be cleared.
+*/
+static int deregister_disk(struct gendisk *disk, drive_info_struct *drv,
+                           int clear_all)
+{
         ctlr_info_t *h = get_host(disk);
-        drive_info_struct *drv = get_drv(disk);
-        int ctlr = h->ctlr;
 
         if (!capable(CAP_SYS_RAWIO))
                 return -EPERM;
 
-        spin_lock_irqsave(CCISS_LOCK(ctlr), flags);
         /* make sure logical volume is NOT is use */
-        if( drv->usage_count > 1) {
-                spin_unlock_irqrestore(CCISS_LOCK(ctlr), flags);
+        if(clear_all || (h->gendisk[0] == disk)) {
+        if (drv->usage_count > 1)
                 return -EBUSY;
         }
-        drv->usage_count++;
-        spin_unlock_irqrestore(CCISS_LOCK(ctlr), flags);
+        else
+                if( drv->usage_count > 0 )
+                        return -EBUSY;
 
-        /* invalidate the devices and deregister the disk */ 
-        if (disk->flags & GENHD_FL_UP)
+        /* invalidate the devices and deregister the disk.  If it is disk
+         * zero do not deregister it but just zero out it's values.  This
+         * allows us to delete disk zero but keep the controller registered.
+        */
+        if (h->gendisk[0] != disk){
+                if (disk->flags & GENHD_FL_UP){
+                        blk_cleanup_queue(disk->queue);
                 del_gendisk(disk);
+                        drv->queue = NULL;
+                }
+        }
+
+        --h->num_luns;
+        /* zero out the disk size info */
+        drv->nr_blocks = 0;
+        drv->block_size = 0;
+        drv->heads = 0;
+        drv->sectors = 0;
+        drv->cylinders = 0;
+        drv->raid_level = -1;   /* This can be used as a flag variable to
+                                 * indicate that this element of the drive
+                                 * array is free.
+                                */
+
+        if (clear_all){
         /* check to see if it was the last disk */
         if (drv == h->drv + h->highest_lun) {
                 /* if so, find the new hightest lun */
                 int i, newhighest =-1;
                 for(i=0; i<h->highest_lun; i++) {
                         /* if the disk has size > 0, it is available */
-                        if (h->drv[i].nr_blocks)
+                                if (h->drv[i].heads)
                                 newhighest = i;
                 }
                 h->highest_lun = newhighest;
-                                
         }
-        --h->num_luns;
-        /* zero out the disk size info */ 
-        drv->nr_blocks = 0;
-        drv->block_size = 0;
-        drv->cylinders = 0;
+
         drv->LunID = 0;
+        }
         return(0);
 }
+
 static int fill_cmd(CommandList_struct *c, __u8 cmd, int ctlr, void *buff,
         size_t size,
         unsigned int use_unit_num, /* 0: address the controller,
@@ -1513,164 +1799,6 @@ cciss_read_capacity(int ctlr, int logvol, ReadCapdata_struct *buf,
         return;
 }
 
-static int register_new_disk(ctlr_info_t *h)
-{
-        struct gendisk *disk;
-        int ctlr = h->ctlr;
-        int i;
-        int num_luns;
-        int logvol;
-        int new_lun_found = 0;
-        int new_lun_index = 0;
-        int free_index_found = 0;
-        int free_index = 0;
-        ReportLunData_struct *ld_buff = NULL;
-        ReadCapdata_struct *size_buff = NULL;
-        InquiryData_struct *inq_buff = NULL;
-        int return_code;
-        int listlength = 0;
-        __u32 lunid = 0;
-        unsigned int block_size;
-        unsigned int total_size;
-
-        if (!capable(CAP_SYS_RAWIO))
-                return -EPERM;
-        /* if we have no space in our disk array left to add anything */
-        if(  h->num_luns >= CISS_MAX_LUN)
-                return -EINVAL;
-        
-        ld_buff = kmalloc(sizeof(ReportLunData_struct), GFP_KERNEL);
-        if (ld_buff == NULL)
-                goto mem_msg;
-        memset(ld_buff, 0, sizeof(ReportLunData_struct));
-        size_buff = kmalloc(sizeof( ReadCapdata_struct), GFP_KERNEL);
-        if (size_buff == NULL)
-                goto mem_msg;
-        inq_buff = kmalloc(sizeof( InquiryData_struct), GFP_KERNEL);
-        if (inq_buff == NULL)
-                goto mem_msg;
-        
-        return_code = sendcmd_withirq(CISS_REPORT_LOG, ctlr, ld_buff, 
-                        sizeof(ReportLunData_struct), 0, 0, 0, TYPE_CMD);
-
-        if( return_code == IO_OK)
-        {
-                
-                // printk("LUN Data\n--------------------------\n");
-
-                listlength |= (0xff & (unsigned int)(ld_buff->LUNListLength[0])) << 24;
-                listlength |= (0xff & (unsigned int)(ld_buff->LUNListLength[1])) << 16;
-                listlength |= (0xff & (unsigned int)(ld_buff->LUNListLength[2])) << 8;  
-                listlength |= 0xff & (unsigned int)(ld_buff->LUNListLength[3]);
-        } else /* reading number of logical volumes failed */
-        {
-                printk(KERN_WARNING "cciss: report logical volume"
-                        " command failed\n");
-                listlength = 0;
-                goto free_err;
-        }
-        num_luns = listlength / 8; // 8 bytes pre entry
-        if (num_luns > CISS_MAX_LUN)
-        {
-                num_luns = CISS_MAX_LUN;
-        }
-#ifdef CCISS_DEBUG
-        printk(KERN_DEBUG "Length = %x %x %x %x = %d\n", ld_buff->LUNListLength[0],
-                ld_buff->LUNListLength[1], ld_buff->LUNListLength[2],
-                ld_buff->LUNListLength[3],  num_luns);
-#endif 
-        for(i=0; i<  num_luns; i++)
-        {
-                int j;
-                int lunID_found = 0;
-
-                lunid = (0xff & (unsigned int)(ld_buff->LUN[i][3])) << 24;
-                lunid |= (0xff & (unsigned int)(ld_buff->LUN[i][2])) << 16;
-                lunid |= (0xff & (unsigned int)(ld_buff->LUN[i][1])) << 8;
-                lunid |= 0xff & (unsigned int)(ld_buff->LUN[i][0]);
-                
-                /* check to see if this is a new lun */ 
-                for(j=0; j <= h->highest_lun; j++)
-                {
-#ifdef CCISS_DEBUG
-                        printk("Checking %d %x against %x\n", j,h->drv[j].LunID,
-                                                lunid);
-#endif /* CCISS_DEBUG */
-                        if (h->drv[j].LunID == lunid)
-                        {
-                                lunID_found = 1;
-                                break;
-                        }
-                        
-                }
-                if( lunID_found == 1)
-                        continue;
-                else
-                {       /* It is the new lun we have been looking for */
-#ifdef CCISS_DEBUG
-                        printk("new lun found at %d\n", i);
-#endif /* CCISS_DEBUG */
-                        new_lun_index = i;
-                        new_lun_found = 1;
-                        break;  
-                }
-         }
-         if (!new_lun_found)
-         {
-                printk(KERN_WARNING "cciss:  New Logical Volume not found\n");
-                goto free_err;
-         }
-         /* Now find the free index     */
-        for(i=0; i <CISS_MAX_LUN; i++)
-        {
-#ifdef CCISS_DEBUG
-                printk("Checking Index %d\n", i);
-#endif /* CCISS_DEBUG */
-                if(h->drv[i].LunID == 0)
-                {
-#ifdef CCISS_DEBUG
-                        printk("free index found at %d\n", i);
-#endif /* CCISS_DEBUG */
-                        free_index_found = 1;
-                        free_index = i;
-                        break;
-                }
-        }
-        if (!free_index_found)
-        {
-                printk(KERN_WARNING "cciss: unable to find free slot for disk\n");
-                goto free_err;
-         }
-
-        logvol = free_index;
-        h->drv[logvol].LunID = lunid;
-                /* there could be gaps in lun numbers, track hightest */
-        if(h->highest_lun < lunid)
-                h->highest_lun = logvol;
-        cciss_read_capacity(ctlr, logvol, size_buff, 1,
-                &total_size, &block_size);
-        cciss_geometry_inquiry(ctlr, logvol, 1, total_size, block_size,
-                        inq_buff, &h->drv[logvol]);
-        h->drv[logvol].usage_count = 0;
-        ++h->num_luns;
-        /* setup partitions per disk */
-        disk = h->gendisk[logvol];
-        set_capacity(disk, h->drv[logvol].nr_blocks);
-        /* if it's the controller it's already added */
-        if(logvol)
-                add_disk(disk);
-freeret:
-        kfree(ld_buff);
-        kfree(size_buff);
-        kfree(inq_buff);
-        return (logvol);
-mem_msg:
-        printk(KERN_ERR "cciss: out of memory\n");
-free_err:
-        logvol = -1;
-        goto freeret;
-}
-
 static int cciss_revalidate(struct gendisk *disk)
 {
         ctlr_info_t *h = get_host(disk);
@@ -2652,12 +2780,16 @@ static void cciss_getgeometry(int cntl_num)
 #endif /* CCISS_DEBUG */
 
         hba[cntl_num]->highest_lun = hba[cntl_num]->num_luns-1;
-        for(i=0; i<  hba[cntl_num]->num_luns; i++)
+//      for(i=0; i<  hba[cntl_num]->num_luns; i++)
+        for(i=0; i < CISS_MAX_LUN; i++)
         {
-
-                lunid = (0xff & (unsigned int)(ld_buff->LUN[i][3])) << 24;
-                lunid |= (0xff & (unsigned int)(ld_buff->LUN[i][2])) << 16;
-                lunid |= (0xff & (unsigned int)(ld_buff->LUN[i][1])) << 8;
+                if (i < hba[cntl_num]->num_luns){
+                        lunid = (0xff & (unsigned int)(ld_buff->LUN[i][3]))
+                                 << 24;
+                        lunid |= (0xff & (unsigned int)(ld_buff->LUN[i][2]))
+                                 << 16;
+                        lunid |= (0xff & (unsigned int)(ld_buff->LUN[i][1]))
+                                 << 8;
                 lunid |= 0xff & (unsigned int)(ld_buff->LUN[i][0]);
                 
                 hba[cntl_num]->drv[i].LunID = lunid;
@@ -2665,13 +2797,18 @@ static void cciss_getgeometry(int cntl_num)
 
 #ifdef CCISS_DEBUG
                 printk(KERN_DEBUG "LUN[%d]:  %x %x %x %x = %x\n", i, 
-                ld_buff->LUN[i][0], ld_buff->LUN[i][1],ld_buff->LUN[i][2], 
-                ld_buff->LUN[i][3], hba[cntl_num]->drv[i].LunID);
+                        ld_buff->LUN[i][0], ld_buff->LUN[i][1],
+                        ld_buff->LUN[i][2], ld_buff->LUN[i][3],
+                        hba[cntl_num]->drv[i].LunID);
 #endif /* CCISS_DEBUG */
                 cciss_read_capacity(cntl_num, i, size_buff, 0,
                         &total_size, &block_size);
-                cciss_geometry_inquiry(cntl_num, i, 0, total_size, block_size,
-                        inq_buff, &hba[cntl_num]->drv[i]);
+                        cciss_geometry_inquiry(cntl_num, i, 0, total_size,
+                                block_size, inq_buff, &hba[cntl_num]->drv[i]);
+                } else {
+                        /* initialize raid_level to indicate a free space */
+                        hba[cntl_num]->drv[i].raid_level = -1;
+                }
         }
         kfree(ld_buff);
         kfree(size_buff);
diff --git a/drivers/block/cciss.h b/drivers/block/cciss.h
index 11ee83504b38..dec27a961120 100644
--- a/drivers/block/cciss.h
+++ b/drivers/block/cciss.h
@@ -35,7 +35,13 @@ typedef struct _drive_info_struct
         int     heads;
         int     sectors;
         int     cylinders;
-        int     raid_level;
+        int     raid_level; /* set to -1 to indicate that
+                             * the drive is not in use/configured
+                            */
+        int     busy_configuring; /*This is set when the drive is being removed
+                                   *to prevent it from being opened or it's queue
+                                   *from being started.
+                                  */
 } drive_info_struct;
 
 struct ctlr_info