20 files changed, 207 insertions, 26 deletions

diff --git a/drivers/block/DAC960.c b/drivers/block/DAC960.c
index c5f22bb0a48e..4e2c367fec11 100644
--- a/drivers/block/DAC960.c
+++ b/drivers/block/DAC960.c
@@ -79,23 +79,28 @@ static int DAC960_open(struct block_device *bdev, fmode_t mode)
         struct gendisk *disk = bdev->bd_disk;
         DAC960_Controller_T *p = disk->queue->queuedata;
         int drive_nr = (long)disk->private_data;
+        int ret = -ENXIO;
 
+        lock_kernel();
         if (p->FirmwareType == DAC960_V1_Controller) {
                 if (p->V1.LogicalDriveInformation[drive_nr].
                     LogicalDriveState == DAC960_V1_LogicalDrive_Offline)
-                        return -ENXIO;
+                        goto out;
         } else {
                 DAC960_V2_LogicalDeviceInfo_T *i =
                         p->V2.LogicalDeviceInformation[drive_nr];
                 if (!i || i->LogicalDeviceState == DAC960_V2_LogicalDevice_Offline)
-                        return -ENXIO;
+                        goto out;
         }
 
         check_disk_change(bdev);
 
         if (!get_capacity(p->disks[drive_nr]))
-                return -ENXIO;
-        return 0;
+                goto out;
+        ret = 0;
+out:
+        unlock_kernel();
+        return ret;
 }
 
 static int DAC960_getgeo(struct block_device *bdev, struct hd_geometry *geo)
diff --git a/drivers/block/amiflop.c b/drivers/block/amiflop.c
index 0fa26359304c..76f114f0bba3 100644
--- a/drivers/block/amiflop.c
+++ b/drivers/block/amiflop.c
@@ -1555,10 +1555,13 @@ static int floppy_open(struct block_device *bdev, fmode_t mode)
         int old_dev;
         unsigned long flags;
 
+        lock_kernel();
         old_dev = fd_device[drive];
 
-        if (fd_ref[drive] && old_dev != system)
+        if (fd_ref[drive] && old_dev != system) {
+                unlock_kernel();
                 return -EBUSY;
+        }
 
         if (mode & (FMODE_READ|FMODE_WRITE)) {
                 check_disk_change(bdev);
@@ -1571,8 +1574,10 @@ static int floppy_open(struct block_device *bdev, fmode_t mode)
                         fd_deselect (drive);
                         rel_fdc();
 
-                        if (wrprot)
+                        if (wrprot) {
+                                unlock_kernel();
                                 return -EROFS;
+                        }
                 }
         }
 
@@ -1589,6 +1594,7 @@ static int floppy_open(struct block_device *bdev, fmode_t mode)
         printk(KERN_INFO "fd%d: accessing %s-disk with %s-layout\n",drive,
                unit[drive].type->name, data_types[system].name);
 
+        unlock_kernel();
         return 0;
 }
 
@@ -1597,6 +1603,7 @@ static int floppy_release(struct gendisk *disk, fmode_t mode)
         struct amiga_floppy_struct *p = disk->private_data;
         int drive = p - unit;
 
+        lock_kernel();
         if (unit[drive].dirty == 1) {
                 del_timer (flush_track_timer + drive);
                 non_int_flush_track (drive);
@@ -1610,6 +1617,7 @@ static int floppy_release(struct gendisk *disk, fmode_t mode)
 /* the mod_use counter is handled this way */
         floppy_off (drive | 0x40000000);
 #endif
+        unlock_kernel();
         return 0;
 }
 
diff --git a/drivers/block/aoe/aoeblk.c b/drivers/block/aoe/aoeblk.c
index 65deffde60ac..a946929735a5 100644
--- a/drivers/block/aoe/aoeblk.c
+++ b/drivers/block/aoe/aoeblk.c
@@ -12,6 +12,7 @@
 #include <linux/slab.h>
 #include <linux/genhd.h>
 #include <linux/netdevice.h>
+#include <linux/smp_lock.h>
 #include "aoe.h"
 
 static struct kmem_cache *buf_pool_cache;
@@ -124,13 +125,16 @@ aoeblk_open(struct block_device *bdev, fmode_t mode)
         struct aoedev *d = bdev->bd_disk->private_data;
         ulong flags;
 
+        lock_kernel();
         spin_lock_irqsave(&d->lock, flags);
         if (d->flags & DEVFL_UP) {
                 d->nopen++;
                 spin_unlock_irqrestore(&d->lock, flags);
+                unlock_kernel();
                 return 0;
         }
         spin_unlock_irqrestore(&d->lock, flags);
+        unlock_kernel();
         return -ENODEV;
 }
 
diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c
index 1bb8bfcfdbd9..aceb96476524 100644
--- a/drivers/block/ataflop.c
+++ b/drivers/block/ataflop.c
@@ -1850,22 +1850,34 @@ static int floppy_open(struct block_device *bdev, fmode_t mode)
         return 0;
 }
 
+static int floppy_unlocked_open(struct block_device *bdev, fmode_t mode)
+{
+        int ret;
+
+        lock_kernel();
+        ret = floppy_open(bdev, mode);
+        unlock_kernel();
+
+        return ret;
+}
 
 static int floppy_release(struct gendisk *disk, fmode_t mode)
 {
         struct atari_floppy_struct *p = disk->private_data;
+        lock_kernel();
         if (p->ref < 0)
                 p->ref = 0;
         else if (!p->ref--) {
                 printk(KERN_ERR "floppy_release with fd_ref == 0");
                 p->ref = 0;
         }
+        unlock_kernel();
         return 0;
 }
 
 static const struct block_device_operations floppy_fops = {
         .owner          = THIS_MODULE,
-        .open           = floppy_open,
+        .open           = floppy_unlocked_open,
         .release        = floppy_release,
         .ioctl          = fd_ioctl,
         .media_changed  = check_floppy_change,
diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index a6c0494dd054..665a470310a9 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -178,6 +178,7 @@ static void do_cciss_request(struct request_queue *q);
 static irqreturn_t do_cciss_intx(int irq, void *dev_id);
 static irqreturn_t do_cciss_msix_intr(int irq, void *dev_id);
 static int cciss_open(struct block_device *bdev, fmode_t mode);
+static int cciss_unlocked_open(struct block_device *bdev, fmode_t mode);
 static int cciss_release(struct gendisk *disk, fmode_t mode);
 static int do_ioctl(struct block_device *bdev, fmode_t mode,
                     unsigned int cmd, unsigned long arg);
@@ -237,7 +238,7 @@ static int cciss_compat_ioctl(struct block_device *, fmode_t,
 
 static const struct block_device_operations cciss_fops = {
         .owner = THIS_MODULE,
-        .open = cciss_open,
+        .open = cciss_unlocked_open,
         .release = cciss_release,
         .ioctl = do_ioctl,
         .getgeo = cciss_getgeo,
@@ -1042,13 +1043,28 @@ static int cciss_open(struct block_device *bdev, fmode_t mode)
         return 0;
 }
 
+static int cciss_unlocked_open(struct block_device *bdev, fmode_t mode)
+{
+        int ret;
+
+        lock_kernel();
+        ret = cciss_open(bdev, mode);
+        unlock_kernel();
+
+        return ret;
+}
+
 /*
  * Close.  Sync first.
  */
 static int cciss_release(struct gendisk *disk, fmode_t mode)
 {
-        ctlr_info_t *host = get_host(disk);
-        drive_info_struct *drv = get_drv(disk);
+        ctlr_info_t *host;
+        drive_info_struct *drv;
+
+        lock_kernel();
+        host = get_host(disk);
+        drv = get_drv(disk);
 
 #ifdef CCISS_DEBUG
         printk(KERN_DEBUG "cciss_release %s\n", disk->disk_name);
@@ -1056,6 +1072,7 @@ static int cciss_release(struct gendisk *disk, fmode_t mode)
 
         drv->usage_count--;
         host->usage_count--;
+        unlock_kernel();
         return 0;
 }
 
diff --git a/drivers/block/cpqarray.c b/drivers/block/cpqarray.c
index c459aeea3c0c..28937b661564 100644
--- a/drivers/block/cpqarray.c
+++ b/drivers/block/cpqarray.c
@@ -158,7 +158,7 @@ static int sendcmd(
         unsigned int blkcnt,
         unsigned int log_unit );
 
-static int ida_open(struct block_device *bdev, fmode_t mode);
+static int ida_unlocked_open(struct block_device *bdev, fmode_t mode);
 static int ida_release(struct gendisk *disk, fmode_t mode);
 static int ida_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg);
 static int ida_getgeo(struct block_device *bdev, struct hd_geometry *geo);
@@ -196,7 +196,7 @@ static inline ctlr_info_t *get_host(struct gendisk *disk)
 
 static const struct block_device_operations ida_fops  = {
         .owner          = THIS_MODULE,
-        .open           = ida_open,
+        .open           = ida_unlocked_open,
         .release        = ida_release,
         .ioctl          = ida_ioctl,
         .getgeo         = ida_getgeo,
@@ -841,13 +841,29 @@ static int ida_open(struct block_device *bdev, fmode_t mode)
         return 0;
 }
 
+static int ida_unlocked_open(struct block_device *bdev, fmode_t mode)
+{
+        int ret;
+
+        lock_kernel();
+        ret = ida_open(bdev, mode);
+        unlock_kernel();
+
+        return ret;
+}
+
 /*
  * Close.  Sync first.
  */
 static int ida_release(struct gendisk *disk, fmode_t mode)
 {
-        ctlr_info_t *host = get_host(disk);
+        ctlr_info_t *host;
+
+        lock_kernel();
+        host = get_host(disk);
         host->usage_count--;
+        unlock_kernel();
+
         return 0;
 }
 
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index e2ab13d99d69..d2b6764a7b1f 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2604,6 +2604,7 @@ static int drbd_open(struct block_device *bdev, fmode_t mode)
         unsigned long flags;
         int rv = 0;
 
+        lock_kernel();
         spin_lock_irqsave(&mdev->req_lock, flags);
         /* to have a stable mdev->state.role
          * and no race with updating open_cnt */
@@ -2618,6 +2619,7 @@ static int drbd_open(struct block_device *bdev, fmode_t mode)
         if (!rv)
                 mdev->open_cnt++;
         spin_unlock_irqrestore(&mdev->req_lock, flags);
+        unlock_kernel();
 
         return rv;
 }
@@ -2625,7 +2627,9 @@ static int drbd_open(struct block_device *bdev, fmode_t mode)
 static int drbd_release(struct gendisk *gd, fmode_t mode)
 {
         struct drbd_conf *mdev = gd->private_data;
+        lock_kernel();
         mdev->open_cnt--;
+        unlock_kernel();
         return 0;
 }
 
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 40419b066aa9..3126d5122b2b 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -3616,6 +3616,7 @@ static int floppy_release(struct gendisk *disk, fmode_t mode)
 {
         int drive = (long)disk->private_data;
 
+        lock_kernel();
         mutex_lock(&open_lock);
         if (UDRS->fd_ref < 0)
                 UDRS->fd_ref = 0;
@@ -3626,6 +3627,7 @@ static int floppy_release(struct gendisk *disk, fmode_t mode)
         if (!UDRS->fd_ref)
                 opened_bdev[drive] = NULL;
         mutex_unlock(&open_lock);
+        unlock_kernel();
 
         return 0;
 }
@@ -3643,6 +3645,7 @@ static int floppy_open(struct block_device *bdev, fmode_t mode)
         int res = -EBUSY;
         char *tmp;
 
+        lock_kernel();
         mutex_lock(&open_lock);
         old_dev = UDRS->fd_device;
         if (opened_bdev[drive] && opened_bdev[drive] != bdev)
@@ -3719,6 +3722,7 @@ static int floppy_open(struct block_device *bdev, fmode_t mode)
                         goto out;
         }
         mutex_unlock(&open_lock);
+        unlock_kernel();
         return 0;
 out:
         if (UDRS->fd_ref < 0)
@@ -3729,6 +3733,7 @@ out:
                 opened_bdev[drive] = NULL;
 out2:
         mutex_unlock(&open_lock);
+        unlock_kernel();
         return res;
 }
 
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index d285a5481965..f3c636d23718 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -67,6 +67,7 @@
 #include <linux/compat.h>
 #include <linux/suspend.h>
 #include <linux/freezer.h>
+#include <linux/smp_lock.h>
 #include <linux/writeback.h>
 #include <linux/buffer_head.h>          /* for invalidate_bdev() */
 #include <linux/completion.h>
@@ -1408,9 +1409,11 @@ static int lo_open(struct block_device *bdev, fmode_t mode)
 {
         struct loop_device *lo = bdev->bd_disk->private_data;
 
+        lock_kernel();
         mutex_lock(&lo->lo_ctl_mutex);
         lo->lo_refcnt++;
         mutex_unlock(&lo->lo_ctl_mutex);
+        unlock_kernel();
 
         return 0;
 }
@@ -1420,6 +1423,7 @@ static int lo_release(struct gendisk *disk, fmode_t mode)
         struct loop_device *lo = disk->private_data;
         int err;
 
+        lock_kernel();
         mutex_lock(&lo->lo_ctl_mutex);
 
         if (--lo->lo_refcnt)
@@ -1444,6 +1448,7 @@ static int lo_release(struct gendisk *disk, fmode_t mode)
 out:
         mutex_unlock(&lo->lo_ctl_mutex);
 out_unlocked:
+        lock_kernel();
         return 0;
 }
 
diff --git a/drivers/block/paride/pcd.c b/drivers/block/paride/pcd.c
index daba7a62a663..76f8565e1e8d 100644
--- a/drivers/block/paride/pcd.c
+++ b/drivers/block/paride/pcd.c
@@ -225,13 +225,21 @@ static char *pcd_buf;		/* buffer for request in progress */
 static int pcd_block_open(struct block_device *bdev, fmode_t mode)
 {
         struct pcd_unit *cd = bdev->bd_disk->private_data;
-        return cdrom_open(&cd->info, bdev, mode);
+        int ret;
+
+        lock_kernel();
+        ret = cdrom_open(&cd->info, bdev, mode);
+        unlock_kernel();
+
+        return ret;
 }
 
 static int pcd_block_release(struct gendisk *disk, fmode_t mode)
 {
         struct pcd_unit *cd = disk->private_data;
+        lock_kernel();
         cdrom_release(&cd->info, mode);
+        unlock_kernel();
         return 0;
 }
 
diff --git a/drivers/block/paride/pd.c b/drivers/block/paride/pd.c
index c4d6ed9846ca..985f0d4f1d1e 100644
--- a/drivers/block/paride/pd.c
+++ b/drivers/block/paride/pd.c
@@ -736,12 +736,14 @@ static int pd_open(struct block_device *bdev, fmode_t mode)
 {
         struct pd_unit *disk = bdev->bd_disk->private_data;
 
+        lock_kernel();
         disk->access++;
 
         if (disk->removable) {
                 pd_special_command(disk, pd_media_check);
                 pd_special_command(disk, pd_door_lock);
         }
+        unlock_kernel();
         return 0;
 }
 
@@ -783,8 +785,10 @@ static int pd_release(struct gendisk *p, fmode_t mode)
 {
         struct pd_unit *disk = p->private_data;
 
+        lock_kernel();
         if (!--disk->access && disk->removable)
                 pd_special_command(disk, pd_door_unlock);
+        unlock_kernel();
 
         return 0;
 }
diff --git a/drivers/block/paride/pf.c b/drivers/block/paride/pf.c
index 38b4d566b816..4457b494882a 100644
--- a/drivers/block/paride/pf.c
+++ b/drivers/block/paride/pf.c
@@ -300,20 +300,26 @@ static void __init pf_init_units(void)
 static int pf_open(struct block_device *bdev, fmode_t mode)
 {
         struct pf_unit *pf = bdev->bd_disk->private_data;
+        int ret;
 
+        lock_kernel();
         pf_identify(pf);
 
+        ret = -ENODEV;
         if (pf->media_status == PF_NM)
-                return -ENODEV;
+                goto out;
 
+        ret = -EROFS;
         if ((pf->media_status == PF_RO) && (mode & FMODE_WRITE))
-                return -EROFS;
+                goto out;
 
+        ret = 0;
         pf->access++;
         if (pf->removable)
                 pf_lock(pf, 1);
-
-        return 0;
+out:
+        unlock_kernel();
+        return ret;
 }
 
 static int pf_getgeo(struct block_device *bdev, struct hd_geometry *geo)
@@ -354,14 +360,18 @@ static int pf_release(struct gendisk *disk, fmode_t mode)
 {
         struct pf_unit *pf = disk->private_data;
 
-        if (pf->access <= 0)
+        lock_kernel();
+        if (pf->access <= 0) {
+                unlock_kernel();
                 return -EINVAL;
+        }
 
         pf->access--;
 
         if (!pf->access && pf->removable)
                 pf_lock(pf, 0);
 
+        unlock_kernel();
         return 0;
 
 }
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 40f1e31f42c4..b1cbeb59bb76 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -2383,6 +2383,7 @@ static int pkt_open(struct block_device *bdev, fmode_t mode)
 
         VPRINTK(DRIVER_NAME": entering open\n");
 
+        lock_kernel();
         mutex_lock(&ctl_mutex);
         pd = pkt_find_dev_from_minor(MINOR(bdev->bd_dev));
         if (!pd) {
@@ -2410,6 +2411,7 @@ static int pkt_open(struct block_device *bdev, fmode_t mode)
         }
 
         mutex_unlock(&ctl_mutex);
+        unlock_kernel();
         return 0;
 
 out_dec:
@@ -2417,6 +2419,7 @@ out_dec:
 out:
         VPRINTK(DRIVER_NAME": failed open (%d)\n", ret);
         mutex_unlock(&ctl_mutex);
+        unlock_kernel();
         return ret;
 }
 
@@ -2425,6 +2428,7 @@ static int pkt_close(struct gendisk *disk, fmode_t mode)
         struct pktcdvd_device *pd = disk->private_data;
         int ret = 0;
 
+        lock_kernel();
         mutex_lock(&ctl_mutex);
         pd->refcnt--;
         BUG_ON(pd->refcnt < 0);
@@ -2433,6 +2437,7 @@ static int pkt_close(struct gendisk *disk, fmode_t mode)
                 pkt_release_dev(pd, flush);
         }
         mutex_unlock(&ctl_mutex);
+        unlock_kernel();
         return ret;
 }
 
diff --git a/drivers/block/swim.c b/drivers/block/swim.c
index f04f74e3758f..2e46815876df 100644
--- a/drivers/block/swim.c
+++ b/drivers/block/swim.c
@@ -662,11 +662,23 @@ out:
         return err;
 }
 
+static int floppy_unlocked_open(struct block_device *bdev, fmode_t mode)
+{
+        int ret;
+
+        lock_kernel();
+        ret = floppy_open(bdev, mode);
+        unlock_kernel();
+
+        return ret;
+}
+
 static int floppy_release(struct gendisk *disk, fmode_t mode)
 {
         struct floppy_state *fs = disk->private_data;
         struct swim __iomem *base = fs->swd->base;
 
+        lock_kernel();
         if (fs->ref_count < 0)
                 fs->ref_count = 0;
         else if (fs->ref_count > 0)
@@ -674,6 +686,7 @@ static int floppy_release(struct gendisk *disk, fmode_t mode)
 
         if (fs->ref_count == 0)
                 swim_motor(base, OFF);
+        unlock_kernel();
 
         return 0;
 }
@@ -754,7 +767,7 @@ static int floppy_revalidate(struct gendisk *disk)
 
 static const struct block_device_operations floppy_fops = {
         .owner           = THIS_MODULE,
-        .open            = floppy_open,
+        .open            = floppy_unlocked_open,
         .release         = floppy_release,
         .ioctl           = floppy_ioctl,
         .getgeo          = floppy_getgeo,
diff --git a/drivers/block/swim3.c b/drivers/block/swim3.c
index f3657b2a5386..cc6a3864822c 100644
--- a/drivers/block/swim3.c
+++ b/drivers/block/swim3.c
@@ -949,15 +949,28 @@ static int floppy_open(struct block_device *bdev, fmode_t mode)
         return 0;
 }
 
+static int floppy_unlocked_open(struct block_device *bdev, fmode_t mode)
+{
+        int ret;
+
+        lock_kernel();
+        ret = floppy_open(bdev, mode);
+        unlock_kernel();
+
+        return ret;
+}
+
 static int floppy_release(struct gendisk *disk, fmode_t mode)
 {
         struct floppy_state *fs = disk->private_data;
         struct swim3 __iomem *sw = fs->swim3;
+        lock_kernel();
         if (fs->ref_count > 0 && --fs->ref_count == 0) {
                 swim3_action(fs, MOTOR_OFF);
                 out_8(&sw->control_bic, 0xff);
                 swim3_select(fs, RELAX);
         }
+        unlock_kernel();
         return 0;
 }
 
@@ -1008,7 +1021,7 @@ static int floppy_revalidate(struct gendisk *disk)
 }
 
 static const struct block_device_operations floppy_fops = {
-        .open           = floppy_open,
+        .open           = floppy_unlocked_open,
         .release        = floppy_release,
         .ioctl          = floppy_ioctl,
         .media_changed  = floppy_check_change,
diff --git a/drivers/block/ub.c b/drivers/block/ub.c
index 102ed52d0e0f..c48e14878582 100644
--- a/drivers/block/ub.c
+++ b/drivers/block/ub.c
@@ -1711,6 +1711,18 @@ err_open:
         return rc;
 }
 
+static int ub_bd_unlocked_open(struct block_device *bdev, fmode_t mode)
+{
+        int ret;
+
+        lock_kernel();
+        ret = ub_bd_open(bdev, mode);
+        unlock_kernel();
+
+        return ret;
+}
+
+
 /*
  */
 static int ub_bd_release(struct gendisk *disk, fmode_t mode)
@@ -1718,7 +1730,10 @@ static int ub_bd_release(struct gendisk *disk, fmode_t mode)
         struct ub_lun *lun = disk->private_data;
         struct ub_dev *sc = lun->udev;
 
+        lock_kernel();
         ub_put(sc);
+        unlock_kernel();
+
         return 0;
 }
 
@@ -1798,7 +1813,7 @@ static int ub_bd_media_changed(struct gendisk *disk)
 
 static const struct block_device_operations ub_bd_fops = {
         .owner          = THIS_MODULE,
-        .open           = ub_bd_open,
+        .open           = ub_bd_unlocked_open,
         .release        = ub_bd_release,
         .ioctl          = ub_bd_ioctl,
         .media_changed  = ub_bd_media_changed,
diff --git a/drivers/block/viodasd.c b/drivers/block/viodasd.c
index 5663d3c284c8..f651e51a3319 100644
--- a/drivers/block/viodasd.c
+++ b/drivers/block/viodasd.c
@@ -41,6 +41,7 @@
 #include <linux/errno.h>
 #include <linux/init.h>
 #include <linux/string.h>
+#include <linux/smp_lock.h>
 #include <linux/dma-mapping.h>
 #include <linux/completion.h>
 #include <linux/device.h>
@@ -175,6 +176,18 @@ static int viodasd_open(struct block_device *bdev, fmode_t mode)
         return 0;
 }
 
+static int viodasd_unlocked_open(struct block_device *bdev, fmode_t mode)
+{
+        int ret;
+
+        lock_kernel();
+        ret = viodasd_open(bdev, mode);
+        unlock_kernel();
+
+        return ret;
+}
+
+
 /*
  * External release entry point.
  */
@@ -183,6 +196,7 @@ static int viodasd_release(struct gendisk *disk, fmode_t mode)
         struct viodasd_device *d = disk->private_data;
         HvLpEvent_Rc hvrc;
 
+        lock_kernel();
         /* Send the event to OS/400.  We DON'T expect a response */
         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
                         HvLpEvent_Type_VirtualIo,
@@ -195,6 +209,9 @@ static int viodasd_release(struct gendisk *disk, fmode_t mode)
                         0, 0, 0);
         if (hvrc != 0)
                 pr_warning("HV close call failed %d\n", (int)hvrc);
+
+        unlock_kernel();
+
         return 0;
 }
 
@@ -219,7 +236,7 @@ static int viodasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
  */
 static const struct block_device_operations viodasd_fops = {
         .owner = THIS_MODULE,
-        .open = viodasd_open,
+        .open = viodasd_unlocked_open,
         .release = viodasd_release,
         .getgeo = viodasd_getgeo,
 };
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 9119cd3d56a4..91374282755d 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -41,6 +41,7 @@
 #include <linux/cdrom.h>
 #include <linux/module.h>
 #include <linux/slab.h>
+#include <linux/smp_lock.h>
 #include <linux/scatterlist.h>
 
 #include <xen/xen.h>
@@ -1018,13 +1019,18 @@ static int blkfront_is_ready(struct xenbus_device *dev)
 static int blkif_open(struct block_device *bdev, fmode_t mode)
 {
         struct blkfront_info *info = bdev->bd_disk->private_data;
+
+        lock_kernel();
         info->users++;
+        unlock_kernel();
+
         return 0;
 }
 
 static int blkif_release(struct gendisk *disk, fmode_t mode)
 {
         struct blkfront_info *info = disk->private_data;
+        lock_kernel();
         info->users--;
         if (info->users == 0) {
                 /* Check whether we have been instructed to close.  We will
@@ -1036,6 +1042,7 @@ static int blkif_release(struct gendisk *disk, fmode_t mode)
                 if (state == XenbusStateClosing && info->is_ready)
                         blkfront_closing(dev);
         }
+        unlock_kernel();
         return 0;
 }
 
diff --git a/drivers/block/xsysace.c b/drivers/block/xsysace.c
index ac278ac908d5..b71888b909a0 100644
--- a/drivers/block/xsysace.c
+++ b/drivers/block/xsysace.c
@@ -89,6 +89,7 @@
 #include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/blkdev.h>
+#include <linux/smp_lock.h>
 #include <linux/ata.h>
 #include <linux/hdreg.h>
 #include <linux/platform_device.h>
@@ -901,11 +902,14 @@ static int ace_open(struct block_device *bdev, fmode_t mode)
 
         dev_dbg(ace->dev, "ace_open() users=%i\n", ace->users + 1);
 
+        lock_kernel();
         spin_lock_irqsave(&ace->lock, flags);
         ace->users++;
         spin_unlock_irqrestore(&ace->lock, flags);
 
         check_disk_change(bdev);
+        unlock_kernel();
+
         return 0;
 }
 
@@ -917,6 +921,7 @@ static int ace_release(struct gendisk *disk, fmode_t mode)
 
         dev_dbg(ace->dev, "ace_release() users=%i\n", ace->users - 1);
 
+        lock_kernel();
         spin_lock_irqsave(&ace->lock, flags);
         ace->users--;
         if (ace->users == 0) {
@@ -924,6 +929,7 @@ static int ace_release(struct gendisk *disk, fmode_t mode)
                 ace_out(ace, ACE_CTRL, val & ~ACE_CTRL_LOCKREQ);
         }
         spin_unlock_irqrestore(&ace->lock, flags);
+        unlock_kernel();
         return 0;
 }
 
diff --git a/drivers/block/z2ram.c b/drivers/block/z2ram.c
index 9114654b54d9..d75b2bb601ad 100644
--- a/drivers/block/z2ram.c
+++ b/drivers/block/z2ram.c
@@ -33,6 +33,7 @@
 #include <linux/module.h>
 #include <linux/blkdev.h>
 #include <linux/bitops.h>
+#include <linux/smp_lock.h>
 #include <linux/slab.h>
 
 #include <asm/setup.h>
@@ -153,6 +154,7 @@ static int z2_open(struct block_device *bdev, fmode_t mode)
 
     device = MINOR(bdev->bd_dev);
 
+    lock_kernel();
     if ( current_device != -1 && current_device != device )
     {
         rc = -EBUSY;
@@ -294,20 +296,25 @@ static int z2_open(struct block_device *bdev, fmode_t mode)
         set_capacity(z2ram_gendisk, z2ram_size >> 9);
     }
 
+    unlock_kernel();
     return 0;
 
 err_out_kfree:
     kfree(z2ram_map);
 err_out:
+    unlock_kernel();
     return rc;
 }
 
 static int
 z2_release(struct gendisk *disk, fmode_t mode)
 {
-    if ( current_device == -1 )
-        return 0;     
-
+    lock_kernel();
+    if ( current_device == -1 ) {
+        unlock_kernel();
+        return 0;
+    }
+    unlock_kernel();
     /*
      * FIXME: unmap memory
      */