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yaml
---
r: 22652
b: refs/heads/master
c: 6bdaa1f
h: refs/heads/master
v: v3
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James Bottomley authored and James Bottomley committed Mar 19, 2006
1 parent aed0203 commit 297771c
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Showing 2 changed files with 114 additions and 24 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 5baba830e93732e802dc7e0a362eb730e1917f58
refs/heads/master: 6bdaa1f17dd32ec62345c7b57842f53e6278a2fa
136 changes: 113 additions & 23 deletions trunk/drivers/scsi/sd.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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>
Expand Down Expand Up @@ -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 */
Expand All @@ -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);
Expand All @@ -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,
Expand Down Expand Up @@ -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);
Expand All @@ -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;
}
Expand Down Expand Up @@ -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);
}
Expand Down Expand Up @@ -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;

Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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;
Expand All @@ -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;
Expand Down Expand Up @@ -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;
}

Expand All @@ -1639,29 +1724,30 @@ 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;
}

/**
* 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);
Expand Down Expand Up @@ -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);
}

Expand All @@ -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);
Expand Down

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