[SCSI] SCSI st: fix error handling in module init, sysfs

- Notice and handle sysfs errors in module init, tape init

- Properly unwind errors in module init

- Remove bogus st_sysfs_class==NULL test, it is guaranteed !NULL at that point

Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 78 insertions, 37 deletions

diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 7f669b600677..3babdc76b3fb 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -195,9 +195,9 @@ static int sgl_unmap_user_pages(struct scatterlist *, const unsigned int, int);
 static int st_probe(struct device *);
 static int st_remove(struct device *);
 
-static void do_create_driverfs_files(void);
+static int do_create_driverfs_files(void);
 static void do_remove_driverfs_files(void);
-static void do_create_class_files(struct scsi_tape *, int, int);
+static int do_create_class_files(struct scsi_tape *, int, int);
 
 static struct scsi_driver st_template = {
         .owner                  = THIS_MODULE,
@@ -4048,7 +4048,9 @@ static int st_probe(struct device *dev)
                         STm->cdevs[j] = cdev;
 
                 }
-                do_create_class_files(tpnt, dev_num, mode);
+                error = do_create_class_files(tpnt, dev_num, mode);
+                if (error)
+                        goto out_free_tape;
         }
 
         sdev_printk(KERN_WARNING, SDp,
@@ -4157,32 +4159,45 @@ static void scsi_tape_release(struct kref *kref)
 
 static int __init init_st(void)
 {
+        int err;
+
         validate_options();
 
-        printk(KERN_INFO
-                "st: Version %s, fixed bufsize %d, s/g segs %d\n",
+        printk(KERN_INFO "st: Version %s, fixed bufsize %d, s/g segs %d\n",
                 verstr, st_fixed_buffer_size, st_max_sg_segs);
 
         st_sysfs_class = class_create(THIS_MODULE, "scsi_tape");
         if (IS_ERR(st_sysfs_class)) {
-                st_sysfs_class = NULL;
                 printk(KERN_ERR "Unable create sysfs class for SCSI tapes\n");
-                return 1;
+                return PTR_ERR(st_sysfs_class);
         }
 
-        if (!register_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
-                                    ST_MAX_TAPE_ENTRIES, "st")) {
-                if (scsi_register_driver(&st_template.gendrv) == 0) {
-                        do_create_driverfs_files();
-                        return 0;
-                }
-                unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
-                                         ST_MAX_TAPE_ENTRIES);
+        err = register_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
+                                     ST_MAX_TAPE_ENTRIES, "st");
+        if (err) {
+                printk(KERN_ERR "Unable to get major %d for SCSI tapes\n",
+                       SCSI_TAPE_MAJOR);
+                goto err_class;
         }
-        class_destroy(st_sysfs_class);
 
-        printk(KERN_ERR "Unable to get major %d for SCSI tapes\n", SCSI_TAPE_MAJOR);
-        return 1;
+        err = scsi_register_driver(&st_template.gendrv);
+        if (err)
+                goto err_chrdev;
+
+        err = do_create_driverfs_files();
+        if (err)
+                goto err_scsidrv;
+
+        return 0;
+
+err_scsidrv:
+        scsi_unregister_driver(&st_template.gendrv);
+err_chrdev:
+        unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
+                                 ST_MAX_TAPE_ENTRIES);
+err_class:
+        class_destroy(st_sysfs_class);
+        return err;
 }
 
 static void __exit exit_st(void)
@@ -4225,14 +4240,33 @@ static ssize_t st_version_show(struct device_driver *ddd, char *buf)
 }
 static DRIVER_ATTR(version, S_IRUGO, st_version_show, NULL);
 
-static void do_create_driverfs_files(void)
+static int do_create_driverfs_files(void)
 {
         struct device_driver *driverfs = &st_template.gendrv;
+        int err;
+
+        err = driver_create_file(driverfs, &driver_attr_try_direct_io);
+        if (err)
+                return err;
+        err = driver_create_file(driverfs, &driver_attr_fixed_buffer_size);
+        if (err)
+                goto err_try_direct_io;
+        err = driver_create_file(driverfs, &driver_attr_max_sg_segs);
+        if (err)
+                goto err_attr_fixed_buf;
+        err = driver_create_file(driverfs, &driver_attr_version);
+        if (err)
+                goto err_attr_max_sg;
 
-        driver_create_file(driverfs, &driver_attr_try_direct_io);
-        driver_create_file(driverfs, &driver_attr_fixed_buffer_size);
-        driver_create_file(driverfs, &driver_attr_max_sg_segs);
-        driver_create_file(driverfs, &driver_attr_version);
+        return 0;
+
+err_attr_max_sg:
+        driver_remove_file(driverfs, &driver_attr_max_sg_segs);
+err_attr_fixed_buf:
+        driver_remove_file(driverfs, &driver_attr_fixed_buffer_size);
+err_try_direct_io:
+        driver_remove_file(driverfs, &driver_attr_try_direct_io);
+        return err;
 }
 
 static void do_remove_driverfs_files(void)
@@ -4293,15 +4327,12 @@ static ssize_t st_defcompression_show(struct class_device *class_dev, char *buf)
 
 CLASS_DEVICE_ATTR(default_compression, S_IRUGO, st_defcompression_show, NULL);
 
-static void do_create_class_files(struct scsi_tape *STp, int dev_num, int mode)
+static int do_create_class_files(struct scsi_tape *STp, int dev_num, int mode)
 {
         int i, rew, error;
         char name[10];
         struct class_device *st_class_member;
 
-        if (!st_sysfs_class)
-                return;
-
         for (rew=0; rew < 2; rew++) {
                 /* Make sure that the minor numbers corresponding to the four
                    first modes always get the same names */
@@ -4316,18 +4347,24 @@ static void do_create_class_files(struct scsi_tape *STp, int dev_num, int mode)
                 if (IS_ERR(st_class_member)) {
                         printk(KERN_WARNING "st%d: class_device_create failed\n",
                                dev_num);
+                        error = PTR_ERR(st_class_member);
                         goto out;
                 }
                 class_set_devdata(st_class_member, &STp->modes[mode]);
 
-                class_device_create_file(st_class_member,
-                                         &class_device_attr_defined);
-                class_device_create_file(st_class_member,
-                                         &class_device_attr_default_blksize);
-                class_device_create_file(st_class_member,
-                                         &class_device_attr_default_density);
-                class_device_create_file(st_class_member,
-                                         &class_device_attr_default_compression);
+                error = class_device_create_file(st_class_member,
+                                               &class_device_attr_defined);
+                if (error) goto out;
+                error = class_device_create_file(st_class_member,
+                                            &class_device_attr_default_blksize);
+                if (error) goto out;
+                error = class_device_create_file(st_class_member,
+                                            &class_device_attr_default_density);
+                if (error) goto out;
+                error = class_device_create_file(st_class_member,
+                                        &class_device_attr_default_compression);
+                if (error) goto out;
+
                 if (mode == 0 && rew == 0) {
                         error = sysfs_create_link(&STp->device->sdev_gendev.kobj,
                                                   &st_class_member->kobj,
@@ -4336,11 +4373,15 @@ static void do_create_class_files(struct scsi_tape *STp, int dev_num, int mode)
                                 printk(KERN_ERR
                                        "st%d: Can't create sysfs link from SCSI device.\n",
                                        dev_num);
+                                goto out;
                         }
                 }
         }
- out:
-        return;
+
+        return 0;
+
+out:
+        return error;
 }
 
 /* The following functions may be useful for a larger audience. */