SCSI: fix race in device_create

There is a race from when a device is created with device_create() and
then the drvdata is set with a call to dev_set_drvdata() in which a
sysfs file could be open, yet the drvdata will be NULL, causing all
sorts of bad things to happen.

This patch fixes the problem by using the new function,
device_create_drvdata().  It fixes the problem in all of the scsi
drivers that need it.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Doug Gilbert <dgilbert@interlog.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/scsi/ch.c b/drivers/scsi/ch.c
index 75c84d7..c4b938b 100644 (file)
--- a/drivers/scsi/ch.c
+++ b/drivers/scsi/ch.c
@@ -910,9 +910,9 @@ static int ch_probe(struct device *dev)
        ch->minor = minor;
        sprintf(ch->name,"ch%d",ch->minor);
 
-       class_dev = device_create(ch_sysfs_class, dev,
-                                 MKDEV(SCSI_CHANGER_MAJOR,ch->minor),
-                                 "s%s", ch->name);
+       class_dev = device_create_drvdata(ch_sysfs_class, dev,
+                                         MKDEV(SCSI_CHANGER_MAJOR, ch->minor),
+                                         ch, "s%s", ch->name);
        if (IS_ERR(class_dev)) {
                printk(KERN_WARNING "ch%d: device_create failed\n",
                       ch->minor);
@@ -926,7 +926,6 @@ static int ch_probe(struct device *dev)
        if (init)
                ch_init_elem(ch);
 
-       dev_set_drvdata(dev, ch);
        sdev_printk(KERN_INFO, sd, "Attached scsi changer %s\n", ch->name);
 
        return 0;

diff --git a/drivers/scsi/osst.c b/drivers/scsi/osst.c
index 31f7aec..243d8be 100644 (file)
--- a/drivers/scsi/osst.c
+++ b/drivers/scsi/osst.c
@@ -5695,13 +5695,12 @@ static int osst_sysfs_add(dev_t dev, struct device *device, struct osst_tape * S
        struct device *osst_member;
        int err;
 
-       osst_member = device_create(osst_sysfs_class, device, dev, "%s", name);
+       osst_member = device_create_drvdata(osst_sysfs_class, device, dev, STp, "%s", name);
        if (IS_ERR(osst_member)) {
                printk(KERN_WARNING "osst :W: Unable to add sysfs class member %s\n", name);
                return PTR_ERR(osst_member);
        }
 
-       dev_set_drvdata(osst_member, STp);
        err = device_create_file(osst_member, &dev_attr_ADR_rev);
        if (err)
                goto err_out;

diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index c9d7f72..ea0edd1 100644 (file)
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1441,17 +1441,18 @@ sg_add(struct device *cl_dev, struct class_interface *cl_intf)
        if (sg_sysfs_valid) {
                struct device *sg_class_member;
 
-               sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
-                                               MKDEV(SCSI_GENERIC_MAJOR,
-                                                     sdp->index),
-                                               "%s", disk->disk_name);
+               sg_class_member = device_create_drvdata(sg_sysfs_class,
+                                                       cl_dev->parent,
+                                                       MKDEV(SCSI_GENERIC_MAJOR,
+                                                             sdp->index),
+                                                       sdp,
+                                                       "%s", disk->disk_name);
                if (IS_ERR(sg_class_member)) {
                        printk(KERN_ERR "sg_add: "
                               "device_create failed\n");
                        error = PTR_ERR(sg_class_member);
                        goto cdev_add_err;
                }
-               dev_set_drvdata(sg_class_member, sdp);
                error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
                                          &sg_class_member->kobj, "generic");
                if (error)

diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index e8db66a..6e5a5bb 100644 (file)
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -4424,17 +4424,19 @@ static int do_create_class_files(struct scsi_tape *STp, int dev_num, int mode)
                snprintf(name, 10, "%s%s%s", rew ? "n" : "",
                         STp->disk->disk_name, st_formats[i]);
                st_class_member =
-                       device_create(st_sysfs_class, &STp->device->sdev_gendev,
-                                     MKDEV(SCSI_TAPE_MAJOR,
-                                               TAPE_MINOR(dev_num, mode, rew)),
-                                     "%s", name);
+                       device_create_drvdata(st_sysfs_class,
+                                             &STp->device->sdev_gendev,
+                                             MKDEV(SCSI_TAPE_MAJOR,
+                                                   TAPE_MINOR(dev_num,
+                                                             mode, rew)),
+                                             &STp->modes[mode],
+                                             "%s", name);
                if (IS_ERR(st_class_member)) {
                        printk(KERN_WARNING "st%d: device_create failed\n",
                               dev_num);
                        error = PTR_ERR(st_class_member);
                        goto out;
                }
-               dev_set_drvdata(st_class_member, &STp->modes[mode]);
 
                error = device_create_file(st_class_member,
                                           &dev_attr_defined);