1 files changed, 113 insertions, 23 deletions

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 3b01e5d6221c..024ef86c5242 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -47,7 +47,6 @@
 #include <linux/init.h>
 #include <linux/blkdev.h>
 #include <linux/blkpg.h>
-#include <linux/kref.h>
 #include <linux/delay.h>
 #include <linux/mutex.h>
 #include <asm/uaccess.h>
@@ -115,12 +114,10 @@ MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK15_MAJOR);
  */
 #define SD_BUF_SIZE             512
 
-static void scsi_disk_release(struct kref *kref);
-
 struct scsi_disk {
         struct scsi_driver *driver;     /* always &sd_template */
         struct scsi_device *device;
-        struct kref     kref;
+        struct class_device cdev;
         struct gendisk  *disk;
         unsigned int    openers;        /* protected by BKL for now, yuck */
         sector_t        capacity;       /* size in 512-byte sectors */
@@ -131,6 +128,7 @@ struct scsi_disk {
         unsigned        RCD : 1;        /* state of disk RCD bit, unused */
         unsigned        DPOFUA : 1;     /* state of disk DPOFUA bit */
 };
+#define to_scsi_disk(obj) container_of(obj,struct scsi_disk,cdev)
 
 static DEFINE_IDR(sd_index_idr);
 static DEFINE_SPINLOCK(sd_index_lock);
@@ -152,6 +150,92 @@ static int sd_issue_flush(struct device *, sector_t *);
 static void sd_prepare_flush(request_queue_t *, struct request *);
 static void sd_read_capacity(struct scsi_disk *sdkp, char *diskname,
                              unsigned char *buffer);
+static void scsi_disk_release(struct class_device *cdev);
+
+static const char *sd_cache_types[] = {
+        "write through", "none", "write back",
+        "write back, no read (daft)"
+};
+
+static ssize_t sd_store_cache_type(struct class_device *cdev, const char *buf,
+                                   size_t count)
+{
+        int i, ct = -1, rcd, wce, sp;
+        struct scsi_disk *sdkp = to_scsi_disk(cdev);
+        struct scsi_device *sdp = sdkp->device;
+        char buffer[64];
+        char *buffer_data;
+        struct scsi_mode_data data;
+        struct scsi_sense_hdr sshdr;
+        int len;
+
+        if (sdp->type != TYPE_DISK)
+                /* no cache control on RBC devices; theoretically they
+                 * can do it, but there's probably so many exceptions
+                 * it's not worth the risk */
+                return -EINVAL;
+
+        for (i = 0; i < sizeof(sd_cache_types)/sizeof(sd_cache_types[0]); i++) {
+                const int len = strlen(sd_cache_types[i]);
+                if (strncmp(sd_cache_types[i], buf, len) == 0 &&
+                    buf[len] == '\n') {
+                        ct = i;
+                        break;
+                }
+        }
+        if (ct < 0)
+                return -EINVAL;
+        rcd = ct & 0x01 ? 1 : 0;
+        wce = ct & 0x02 ? 1 : 0;
+        if (scsi_mode_sense(sdp, 0x08, 8, buffer, sizeof(buffer), SD_TIMEOUT,
+                            SD_MAX_RETRIES, &data, NULL))
+                return -EINVAL;
+        len = min(sizeof(buffer), data.length - data.header_length -
+                  data.block_descriptor_length);
+        buffer_data = buffer + data.header_length +
+                data.block_descriptor_length;
+        buffer_data[2] &= ~0x05;
+        buffer_data[2] |= wce << 2 | rcd;
+        sp = buffer_data[0] & 0x80 ? 1 : 0;
+
+        if (scsi_mode_select(sdp, 1, sp, 8, buffer_data, len, SD_TIMEOUT,
+                             SD_MAX_RETRIES, &data, &sshdr)) {
+                if (scsi_sense_valid(&sshdr))
+                        scsi_print_sense_hdr(sdkp->disk->disk_name, &sshdr);
+                return -EINVAL;
+        }
+        sd_revalidate_disk(sdkp->disk);
+        return count;
+}
+
+static ssize_t sd_show_cache_type(struct class_device *cdev, char *buf)
+{
+        struct scsi_disk *sdkp = to_scsi_disk(cdev);
+        int ct = sdkp->RCD + 2*sdkp->WCE;
+
+        return snprintf(buf, 40, "%s\n", sd_cache_types[ct]);
+}
+
+static ssize_t sd_show_fua(struct class_device *cdev, char *buf)
+{
+        struct scsi_disk *sdkp = to_scsi_disk(cdev);
+
+        return snprintf(buf, 20, "%u\n", sdkp->DPOFUA);
+}
+
+static struct class_device_attribute sd_disk_attrs[] = {
+        __ATTR(cache_type, S_IRUGO|S_IWUSR, sd_show_cache_type,
+               sd_store_cache_type),
+        __ATTR(FUA, S_IRUGO, sd_show_fua, NULL),
+        __ATTR_NULL,
+};
+
+static struct class sd_disk_class = {
+        .name           = "scsi_disk",
+        .owner          = THIS_MODULE,
+        .release        = scsi_disk_release,
+        .class_dev_attrs = sd_disk_attrs,
+};
 
 static struct scsi_driver sd_template = {
         .owner                  = THIS_MODULE,
@@ -195,8 +279,6 @@ static int sd_major(int major_idx)
         }
 }
 
-#define to_scsi_disk(obj) container_of(obj,struct scsi_disk,kref)
-
 static inline struct scsi_disk *scsi_disk(struct gendisk *disk)
 {
         return container_of(disk->private_data, struct scsi_disk, driver);
@@ -209,7 +291,7 @@ static struct scsi_disk *__scsi_disk_get(struct gendisk *disk)
         if (disk->private_data) {
                 sdkp = scsi_disk(disk);
                 if (scsi_device_get(sdkp->device) == 0)
-                        kref_get(&sdkp->kref);
+                        class_device_get(&sdkp->cdev);
                 else
                         sdkp = NULL;
         }
@@ -243,7 +325,7 @@ static void scsi_disk_put(struct scsi_disk *sdkp)
         struct scsi_device *sdev = sdkp->device;
 
         mutex_lock(&sd_ref_mutex);
-        kref_put(&sdkp->kref, scsi_disk_release);
+        class_device_put(&sdkp->cdev);
         scsi_device_put(sdev);
         mutex_unlock(&sd_ref_mutex);
 }
@@ -1381,10 +1463,6 @@ sd_read_cache_type(struct scsi_disk *sdkp, char *diskname,
         res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr);
 
         if (scsi_status_is_good(res)) {
-                const char *types[] = {
-                        "write through", "none", "write back",
-                        "write back, no read (daft)"
-                };
                 int ct = 0;
                 int offset = data.header_length + data.block_descriptor_length;
 
@@ -1417,7 +1495,7 @@ sd_read_cache_type(struct scsi_disk *sdkp, char *diskname,
                 ct =  sdkp->RCD + 2*sdkp->WCE;
 
                 printk(KERN_NOTICE "SCSI device %s: drive cache: %s%s\n",
-                       diskname, types[ct],
+                       diskname, sd_cache_types[ct],
                        sdkp->DPOFUA ? " w/ FUA" : "");
 
                 return;
@@ -1548,8 +1626,6 @@ static int sd_probe(struct device *dev)
         if (!sdkp)
                 goto out;
 
-        kref_init(&sdkp->kref);
-
         gd = alloc_disk(16);
         if (!gd)
                 goto out_free;
@@ -1566,7 +1642,16 @@ static int sd_probe(struct device *dev)
         if (error)
                 goto out_put;
 
+        class_device_initialize(&sdkp->cdev);
+        sdkp->cdev.dev = &sdp->sdev_gendev;
+        sdkp->cdev.class = &sd_disk_class;
+        strncpy(sdkp->cdev.class_id, sdp->sdev_gendev.bus_id, BUS_ID_SIZE);
+
+        if (class_device_add(&sdkp->cdev))
+                goto out_put;
+
         get_device(&sdp->sdev_gendev);
+
         sdkp->device = sdp;
         sdkp->driver = &sd_template;
         sdkp->disk = gd;
@@ -1616,11 +1701,11 @@ static int sd_probe(struct device *dev)
 
         return 0;
 
-out_put:
+ out_put:
         put_disk(gd);
-out_free:
+ out_free:
         kfree(sdkp);
-out:
+ out:
         return error;
 }
 
@@ -1639,12 +1724,13 @@ static int sd_remove(struct device *dev)
 {
         struct scsi_disk *sdkp = dev_get_drvdata(dev);
 
+        class_device_del(&sdkp->cdev);
         del_gendisk(sdkp->disk);
         sd_shutdown(dev);
 
         mutex_lock(&sd_ref_mutex);
         dev_set_drvdata(dev, NULL);
-        kref_put(&sdkp->kref, scsi_disk_release);
+        class_device_put(&sdkp->cdev);
         mutex_unlock(&sd_ref_mutex);
 
         return 0;
@@ -1652,16 +1738,16 @@ static int sd_remove(struct device *dev)
 
 /**
  *      scsi_disk_release - Called to free the scsi_disk structure
- *      @kref: pointer to embedded kref
+ *      @cdev: pointer to embedded class device
  *
  *      sd_ref_mutex must be held entering this routine.  Because it is
  *      called on last put, you should always use the scsi_disk_get()
  *      scsi_disk_put() helpers which manipulate the semaphore directly
- *      and never do a direct kref_put().
+ *      and never do a direct class_device_put().
  **/
-static void scsi_disk_release(struct kref *kref)
+static void scsi_disk_release(struct class_device *cdev)
 {
-        struct scsi_disk *sdkp = to_scsi_disk(kref);
+        struct scsi_disk *sdkp = to_scsi_disk(cdev);
         struct gendisk *disk = sdkp->disk;
         
         spin_lock(&sd_index_lock);
@@ -1715,6 +1801,8 @@ static int __init init_sd(void)
         if (!majors)
                 return -ENODEV;
 
+        class_register(&sd_disk_class);
+
         return scsi_register_driver(&sd_template.gendrv);
 }
 
@@ -1732,6 +1820,8 @@ static void __exit exit_sd(void)
         scsi_unregister_driver(&sd_template.gendrv);
         for (i = 0; i < SD_MAJORS; i++)
                 unregister_blkdev(sd_major(i), "sd");
+
+        class_unregister(&sd_disk_class);
 }
 
 module_init(init_sd);