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linux/drivers/scsi/sd.c
Alan Stern b4d38e38e6 [SCSI] Reduce polling in sd.c 
If a drive reports that no media is present, there's no point in
continuing to ask it about media status.  This patch (as696) cuts the
TUR polling short as soon as the drive reports no media instead of
going a full 3 iterations.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-11-15 12:11:36 -06:00

1846 lines
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/*
* sd.c Copyright (C) 1992 Drew Eckhardt
* Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
*
* Linux scsi disk driver
* Initial versions: Drew Eckhardt
* Subsequent revisions: Eric Youngdale
* Modification history:
* - Drew Eckhardt <drew@colorado.edu> original
* - Eric Youngdale <eric@andante.org> add scatter-gather, multiple
* outstanding request, and other enhancements.
* Support loadable low-level scsi drivers.
* - Jirka Hanika <geo@ff.cuni.cz> support more scsi disks using
* eight major numbers.
* - Richard Gooch <rgooch@atnf.csiro.au> support devfs.
* - Torben Mathiasen <tmm@image.dk> Resource allocation fixes in
* sd_init and cleanups.
* - Alex Davis <letmein@erols.com> Fix problem where partition info
* not being read in sd_open. Fix problem where removable media
* could be ejected after sd_open.
* - Douglas Gilbert <dgilbert@interlog.com> cleanup for lk 2.5.x
* - Badari Pulavarty <pbadari@us.ibm.com>, Matthew Wilcox
* <willy@debian.org>, Kurt Garloff <garloff@suse.de>:
* Support 32k/1M disks.
*
* Logging policy (needs CONFIG_SCSI_LOGGING defined):
* - setting up transfer: SCSI_LOG_HLQUEUE levels 1 and 2
* - end of transfer (bh + scsi_lib): SCSI_LOG_HLCOMPLETE level 1
* - entering sd_ioctl: SCSI_LOG_IOCTL level 1
* - entering other commands: SCSI_LOG_HLQUEUE level 3
* Note: when the logging level is set by the user, it must be greater
* than the level indicated above to trigger output.
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/bio.h>
#include <linux/genhd.h>
#include <linux/hdreg.h>
#include <linux/errno.h>
#include <linux/idr.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/blkpg.h>
#include <linux/delay.h>
#include <linux/mutex.h>
#include <asm/uaccess.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_driver.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_ioctl.h>
#include <scsi/scsicam.h>
#include "scsi_logging.h"
/*
* More than enough for everybody ;) The huge number of majors
* is a leftover from 16bit dev_t days, we don't really need that
* much numberspace.
*/
#define SD_MAJORS 16
MODULE_AUTHOR("Eric Youngdale");
MODULE_DESCRIPTION("SCSI disk (sd) driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK0_MAJOR);
MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK1_MAJOR);
MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK2_MAJOR);
MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK3_MAJOR);
MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK4_MAJOR);
MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK5_MAJOR);
MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK6_MAJOR);
MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK7_MAJOR);
MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK8_MAJOR);
MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK9_MAJOR);
MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK10_MAJOR);
MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK11_MAJOR);
MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK12_MAJOR);
MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK13_MAJOR);
MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK14_MAJOR);
MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK15_MAJOR);
/*
* This is limited by the naming scheme enforced in sd_probe,
* add another character to it if you really need more disks.
*/
#define SD_MAX_DISKS (((26 * 26) + 26 + 1) * 26)
/*
* Time out in seconds for disks and Magneto-opticals (which are slower).
*/
#define SD_TIMEOUT (30 * HZ)
#define SD_MOD_TIMEOUT (75 * HZ)
/*
* Number of allowed retries
*/
#define SD_MAX_RETRIES 5
#define SD_PASSTHROUGH_RETRIES 1
/*
* Size of the initial data buffer for mode and read capacity data
*/
#define SD_BUF_SIZE 512
struct scsi_disk {
struct scsi_driver *driver; /* always &sd_template */
struct scsi_device *device;
struct class_device cdev;
struct gendisk *disk;
unsigned int openers; /* protected by BKL for now, yuck */
sector_t capacity; /* size in 512-byte sectors */
u32 index;
u8 media_present;
u8 write_prot;
unsigned WCE : 1; /* state of disk WCE bit */
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);
/* This semaphore is used to mediate the 0->1 reference get in the
* face of object destruction (i.e. we can't allow a get on an
* object after last put) */
static DEFINE_MUTEX(sd_ref_mutex);
static int sd_revalidate_disk(struct gendisk *disk);
static void sd_rw_intr(struct scsi_cmnd * SCpnt);
static int sd_probe(struct device *);
static int sd_remove(struct device *);
static void sd_shutdown(struct device *dev);
static void sd_rescan(struct device *);
static int sd_init_command(struct scsi_cmnd *);
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 < ARRAY_SIZE(sd_cache_types); 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_t(size_t, 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_store_allow_restart(struct class_device *cdev, const char *buf,
size_t count)
{
struct scsi_disk *sdkp = to_scsi_disk(cdev);
struct scsi_device *sdp = sdkp->device;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
if (sdp->type != TYPE_DISK)
return -EINVAL;
sdp->allow_restart = simple_strtoul(buf, NULL, 10);
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 ssize_t sd_show_allow_restart(struct class_device *cdev, char *buf)
{
struct scsi_disk *sdkp = to_scsi_disk(cdev);
return snprintf(buf, 40, "%d\n", sdkp->device->allow_restart);
}
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(allow_restart, S_IRUGO|S_IWUSR, sd_show_allow_restart,
sd_store_allow_restart),
__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,
.gendrv = {
.name = "sd",
.probe = sd_probe,
.remove = sd_remove,
.shutdown = sd_shutdown,
},
.rescan = sd_rescan,
.init_command = sd_init_command,
.issue_flush = sd_issue_flush,
};
/*
* Device no to disk mapping:
*
* major disc2 disc p1
* |............|.............|....|....| <- dev_t
* 31 20 19 8 7 4 3 0
*
* Inside a major, we have 16k disks, however mapped non-
* contiguously. The first 16 disks are for major0, the next
* ones with major1, ... Disk 256 is for major0 again, disk 272
* for major1, ...
* As we stay compatible with our numbering scheme, we can reuse
* the well-know SCSI majors 8, 65--71, 136--143.
*/
static int sd_major(int major_idx)
{
switch (major_idx) {
case 0:
return SCSI_DISK0_MAJOR;
case 1 ... 7:
return SCSI_DISK1_MAJOR + major_idx - 1;
case 8 ... 15:
return SCSI_DISK8_MAJOR + major_idx - 8;
default:
BUG();
return 0; /* shut up gcc */
}
}
static inline struct scsi_disk *scsi_disk(struct gendisk *disk)
{
return container_of(disk->private_data, struct scsi_disk, driver);
}
static struct scsi_disk *__scsi_disk_get(struct gendisk *disk)
{
struct scsi_disk *sdkp = NULL;
if (disk->private_data) {
sdkp = scsi_disk(disk);
if (scsi_device_get(sdkp->device) == 0)
class_device_get(&sdkp->cdev);
else
sdkp = NULL;
}
return sdkp;
}
static struct scsi_disk *scsi_disk_get(struct gendisk *disk)
{
struct scsi_disk *sdkp;
mutex_lock(&sd_ref_mutex);
sdkp = __scsi_disk_get(disk);
mutex_unlock(&sd_ref_mutex);
return sdkp;
}
static struct scsi_disk *scsi_disk_get_from_dev(struct device *dev)
{
struct scsi_disk *sdkp;
mutex_lock(&sd_ref_mutex);
sdkp = dev_get_drvdata(dev);
if (sdkp)
sdkp = __scsi_disk_get(sdkp->disk);
mutex_unlock(&sd_ref_mutex);
return sdkp;
}
static void scsi_disk_put(struct scsi_disk *sdkp)
{
struct scsi_device *sdev = sdkp->device;
mutex_lock(&sd_ref_mutex);
class_device_put(&sdkp->cdev);
scsi_device_put(sdev);
mutex_unlock(&sd_ref_mutex);
}
/**
* sd_init_command - build a scsi (read or write) command from
* information in the request structure.
* @SCpnt: pointer to mid-level's per scsi command structure that
* contains request and into which the scsi command is written
*
* Returns 1 if successful and 0 if error (or cannot be done now).
**/
static int sd_init_command(struct scsi_cmnd * SCpnt)
{
struct scsi_device *sdp = SCpnt->device;
struct request *rq = SCpnt->request;
struct gendisk *disk = rq->rq_disk;
sector_t block = rq->sector;
unsigned int this_count = SCpnt->request_bufflen >> 9;
unsigned int timeout = sdp->timeout;
SCSI_LOG_HLQUEUE(1, printk("sd_init_command: disk=%s, block=%llu, "
"count=%d\n", disk->disk_name,
(unsigned long long)block, this_count));
if (!sdp || !scsi_device_online(sdp) ||
block + rq->nr_sectors > get_capacity(disk)) {
SCSI_LOG_HLQUEUE(2, printk("Finishing %ld sectors\n",
rq->nr_sectors));
SCSI_LOG_HLQUEUE(2, printk("Retry with 0x%p\n", SCpnt));
return 0;
}
if (sdp->changed) {
/*
* quietly refuse to do anything to a changed disc until
* the changed bit has been reset
*/
/* printk("SCSI disk has been changed. Prohibiting further I/O.\n"); */
return 0;
}
SCSI_LOG_HLQUEUE(2, printk("%s : block=%llu\n",
disk->disk_name, (unsigned long long)block));
/*
* If we have a 1K hardware sectorsize, prevent access to single
* 512 byte sectors. In theory we could handle this - in fact
* the scsi cdrom driver must be able to handle this because
* we typically use 1K blocksizes, and cdroms typically have
* 2K hardware sectorsizes. Of course, things are simpler
* with the cdrom, since it is read-only. For performance
* reasons, the filesystems should be able to handle this
* and not force the scsi disk driver to use bounce buffers
* for this.
*/
if (sdp->sector_size == 1024) {
if ((block & 1) || (rq->nr_sectors & 1)) {
printk(KERN_ERR "sd: Bad block number requested");
return 0;
} else {
block = block >> 1;
this_count = this_count >> 1;
}
}
if (sdp->sector_size == 2048) {
if ((block & 3) || (rq->nr_sectors & 3)) {
printk(KERN_ERR "sd: Bad block number requested");
return 0;
} else {
block = block >> 2;
this_count = this_count >> 2;
}
}
if (sdp->sector_size == 4096) {
if ((block & 7) || (rq->nr_sectors & 7)) {
printk(KERN_ERR "sd: Bad block number requested");
return 0;
} else {
block = block >> 3;
this_count = this_count >> 3;
}
}
if (rq_data_dir(rq) == WRITE) {
if (!sdp->writeable) {
return 0;
}
SCpnt->cmnd[0] = WRITE_6;
SCpnt->sc_data_direction = DMA_TO_DEVICE;
} else if (rq_data_dir(rq) == READ) {
SCpnt->cmnd[0] = READ_6;
SCpnt->sc_data_direction = DMA_FROM_DEVICE;
} else {
printk(KERN_ERR "sd: Unknown command %x\n", rq->cmd_flags);
return 0;
}
SCSI_LOG_HLQUEUE(2, printk("%s : %s %d/%ld 512 byte blocks.\n",
disk->disk_name, (rq_data_dir(rq) == WRITE) ?
"writing" : "reading", this_count, rq->nr_sectors));
SCpnt->cmnd[1] = 0;
if (block > 0xffffffff) {
SCpnt->cmnd[0] += READ_16 - READ_6;
SCpnt->cmnd[1] |= blk_fua_rq(rq) ? 0x8 : 0;
SCpnt->cmnd[2] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0;
SCpnt->cmnd[3] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0;
SCpnt->cmnd[4] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0;
SCpnt->cmnd[5] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0;
SCpnt->cmnd[6] = (unsigned char) (block >> 24) & 0xff;
SCpnt->cmnd[7] = (unsigned char) (block >> 16) & 0xff;
SCpnt->cmnd[8] = (unsigned char) (block >> 8) & 0xff;
SCpnt->cmnd[9] = (unsigned char) block & 0xff;
SCpnt->cmnd[10] = (unsigned char) (this_count >> 24) & 0xff;
SCpnt->cmnd[11] = (unsigned char) (this_count >> 16) & 0xff;
SCpnt->cmnd[12] = (unsigned char) (this_count >> 8) & 0xff;
SCpnt->cmnd[13] = (unsigned char) this_count & 0xff;
SCpnt->cmnd[14] = SCpnt->cmnd[15] = 0;
} else if ((this_count > 0xff) || (block > 0x1fffff) ||
SCpnt->device->use_10_for_rw) {
if (this_count > 0xffff)
this_count = 0xffff;
SCpnt->cmnd[0] += READ_10 - READ_6;
SCpnt->cmnd[1] |= blk_fua_rq(rq) ? 0x8 : 0;
SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
SCpnt->cmnd[5] = (unsigned char) block & 0xff;
SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
} else {
if (unlikely(blk_fua_rq(rq))) {
/*
* This happens only if this drive failed
* 10byte rw command with ILLEGAL_REQUEST
* during operation and thus turned off
* use_10_for_rw.
*/
printk(KERN_ERR "sd: FUA write on READ/WRITE(6) drive\n");
return 0;
}
SCpnt->cmnd[1] |= (unsigned char) ((block >> 16) & 0x1f);
SCpnt->cmnd[2] = (unsigned char) ((block >> 8) & 0xff);
SCpnt->cmnd[3] = (unsigned char) block & 0xff;
SCpnt->cmnd[4] = (unsigned char) this_count;
SCpnt->cmnd[5] = 0;
}
SCpnt->request_bufflen = this_count * sdp->sector_size;
/*
* We shouldn't disconnect in the middle of a sector, so with a dumb
* host adapter, it's safe to assume that we can at least transfer
* this many bytes between each connect / disconnect.
*/
SCpnt->transfersize = sdp->sector_size;
SCpnt->underflow = this_count << 9;
SCpnt->allowed = SD_MAX_RETRIES;
SCpnt->timeout_per_command = timeout;
/*
* This is the completion routine we use. This is matched in terms
* of capability to this function.
*/
SCpnt->done = sd_rw_intr;
/*
* This indicates that the command is ready from our end to be
* queued.
*/
return 1;
}
/**
* sd_open - open a scsi disk device
* @inode: only i_rdev member may be used
* @filp: only f_mode and f_flags may be used
*
* Returns 0 if successful. Returns a negated errno value in case
* of error.
*
* Note: This can be called from a user context (e.g. fsck(1) )
* or from within the kernel (e.g. as a result of a mount(1) ).
* In the latter case @inode and @filp carry an abridged amount
* of information as noted above.
**/
static int sd_open(struct inode *inode, struct file *filp)
{
struct gendisk *disk = inode->i_bdev->bd_disk;
struct scsi_disk *sdkp;
struct scsi_device *sdev;
int retval;
if (!(sdkp = scsi_disk_get(disk)))
return -ENXIO;
SCSI_LOG_HLQUEUE(3, printk("sd_open: disk=%s\n", disk->disk_name));
sdev = sdkp->device;
/*
* If the device is in error recovery, wait until it is done.
* If the device is offline, then disallow any access to it.
*/
retval = -ENXIO;
if (!scsi_block_when_processing_errors(sdev))
goto error_out;
if (sdev->removable || sdkp->write_prot)
check_disk_change(inode->i_bdev);
/*
* If the drive is empty, just let the open fail.
*/
retval = -ENOMEDIUM;
if (sdev->removable && !sdkp->media_present &&
!(filp->f_flags & O_NDELAY))
goto error_out;
/*
* If the device has the write protect tab set, have the open fail
* if the user expects to be able to write to the thing.
*/
retval = -EROFS;
if (sdkp->write_prot && (filp->f_mode & FMODE_WRITE))
goto error_out;
/*
* It is possible that the disk changing stuff resulted in
* the device being taken offline. If this is the case,
* report this to the user, and don't pretend that the
* open actually succeeded.
*/
retval = -ENXIO;
if (!scsi_device_online(sdev))
goto error_out;
if (!sdkp->openers++ && sdev->removable) {
if (scsi_block_when_processing_errors(sdev))
scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
}
return 0;
error_out:
scsi_disk_put(sdkp);
return retval;
}
/**
* sd_release - invoked when the (last) close(2) is called on this
* scsi disk.
* @inode: only i_rdev member may be used
* @filp: only f_mode and f_flags may be used
*
* Returns 0.
*
* Note: may block (uninterruptible) if error recovery is underway
* on this disk.
**/
static int sd_release(struct inode *inode, struct file *filp)
{
struct gendisk *disk = inode->i_bdev->bd_disk;
struct scsi_disk *sdkp = scsi_disk(disk);
struct scsi_device *sdev = sdkp->device;
SCSI_LOG_HLQUEUE(3, printk("sd_release: disk=%s\n", disk->disk_name));
if (!--sdkp->openers && sdev->removable) {
if (scsi_block_when_processing_errors(sdev))
scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
}
/*
* XXX and what if there are packets in flight and this close()
* XXX is followed by a "rmmod sd_mod"?
*/
scsi_disk_put(sdkp);
return 0;
}
static int sd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
struct scsi_device *sdp = sdkp->device;
struct Scsi_Host *host = sdp->host;
int diskinfo[4];
/* default to most commonly used values */
diskinfo[0] = 0x40; /* 1 << 6 */
diskinfo[1] = 0x20; /* 1 << 5 */
diskinfo[2] = sdkp->capacity >> 11;
/* override with calculated, extended default, or driver values */
if (host->hostt->bios_param)
host->hostt->bios_param(sdp, bdev, sdkp->capacity, diskinfo);
else
scsicam_bios_param(bdev, sdkp->capacity, diskinfo);
geo->heads = diskinfo[0];
geo->sectors = diskinfo[1];
geo->cylinders = diskinfo[2];
return 0;
}
/**
* sd_ioctl - process an ioctl
* @inode: only i_rdev/i_bdev members may be used
* @filp: only f_mode and f_flags may be used
* @cmd: ioctl command number
* @arg: this is third argument given to ioctl(2) system call.
* Often contains a pointer.
*
* Returns 0 if successful (some ioctls return postive numbers on
* success as well). Returns a negated errno value in case of error.
*
* Note: most ioctls are forward onto the block subsystem or further
* down in the scsi subsytem.
**/
static int sd_ioctl(struct inode * inode, struct file * filp,
unsigned int cmd, unsigned long arg)
{
struct block_device *bdev = inode->i_bdev;
struct gendisk *disk = bdev->bd_disk;
struct scsi_device *sdp = scsi_disk(disk)->device;
void __user *p = (void __user *)arg;
int error;
SCSI_LOG_IOCTL(1, printk("sd_ioctl: disk=%s, cmd=0x%x\n",
disk->disk_name, cmd));
/*
* If we are in the middle of error recovery, don't let anyone
* else try and use this device. Also, if error recovery fails, it
* may try and take the device offline, in which case all further
* access to the device is prohibited.
*/
error = scsi_nonblockable_ioctl(sdp, cmd, p, filp);
if (!scsi_block_when_processing_errors(sdp) || !error)
return error;
/*
* Send SCSI addressing ioctls directly to mid level, send other
* ioctls to block level and then onto mid level if they can't be
* resolved.
*/
switch (cmd) {
case SCSI_IOCTL_GET_IDLUN:
case SCSI_IOCTL_GET_BUS_NUMBER:
return scsi_ioctl(sdp, cmd, p);
default:
error = scsi_cmd_ioctl(filp, disk, cmd, p);
if (error != -ENOTTY)
return error;
}
return scsi_ioctl(sdp, cmd, p);
}
static void set_media_not_present(struct scsi_disk *sdkp)
{
sdkp->media_present = 0;
sdkp->capacity = 0;
sdkp->device->changed = 1;
}
/**
* sd_media_changed - check if our medium changed
* @disk: kernel device descriptor
*
* Returns 0 if not applicable or no change; 1 if change
*
* Note: this function is invoked from the block subsystem.
**/
static int sd_media_changed(struct gendisk *disk)
{
struct scsi_disk *sdkp = scsi_disk(disk);
struct scsi_device *sdp = sdkp->device;
int retval;
SCSI_LOG_HLQUEUE(3, printk("sd_media_changed: disk=%s\n",
disk->disk_name));
if (!sdp->removable)
return 0;
/*
* If the device is offline, don't send any commands - just pretend as
* if the command failed. If the device ever comes back online, we
* can deal with it then. It is only because of unrecoverable errors
* that we would ever take a device offline in the first place.
*/
if (!scsi_device_online(sdp))
goto not_present;
/*
* Using TEST_UNIT_READY enables differentiation between drive with
* no cartridge loaded - NOT READY, drive with changed cartridge -
* UNIT ATTENTION, or with same cartridge - GOOD STATUS.
*
* Drives that auto spin down. eg iomega jaz 1G, will be started
* by sd_spinup_disk() from sd_revalidate_disk(), which happens whenever
* sd_revalidate() is called.
*/
retval = -ENODEV;
if (scsi_block_when_processing_errors(sdp))
retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES);
/*
* Unable to test, unit probably not ready. This usually
* means there is no disc in the drive. Mark as changed,
* and we will figure it out later once the drive is
* available again.
*/
if (retval)
goto not_present;
/*
* For removable scsi disk we have to recognise the presence
* of a disk in the drive. This is kept in the struct scsi_disk
* struct and tested at open ! Daniel Roche (dan@lectra.fr)
*/
sdkp->media_present = 1;
retval = sdp->changed;
sdp->changed = 0;
return retval;
not_present:
set_media_not_present(sdkp);
return 1;
}
static int sd_sync_cache(struct scsi_device *sdp)
{
int retries, res;
struct scsi_sense_hdr sshdr;
if (!scsi_device_online(sdp))
return -ENODEV;
for (retries = 3; retries > 0; --retries) {
unsigned char cmd[10] = { 0 };
cmd[0] = SYNCHRONIZE_CACHE;
/*
* Leave the rest of the command zero to indicate
* flush everything.
*/
res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
SD_TIMEOUT, SD_MAX_RETRIES);
if (res == 0)
break;
}
if (res) { printk(KERN_WARNING "FAILED\n status = %x, message = %02x, "
"host = %d, driver = %02x\n ",
status_byte(res), msg_byte(res),
host_byte(res), driver_byte(res));
if (driver_byte(res) & DRIVER_SENSE)
scsi_print_sense_hdr("sd", &sshdr);
}
return res;
}
static int sd_issue_flush(struct device *dev, sector_t *error_sector)
{
int ret = 0;
struct scsi_device *sdp = to_scsi_device(dev);
struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
if (!sdkp)
return -ENODEV;
if (sdkp->WCE)
ret = sd_sync_cache(sdp);
scsi_disk_put(sdkp);
return ret;
}
static void sd_prepare_flush(request_queue_t *q, struct request *rq)
{
memset(rq->cmd, 0, sizeof(rq->cmd));
rq->cmd_type = REQ_TYPE_BLOCK_PC;
rq->timeout = SD_TIMEOUT;
rq->cmd[0] = SYNCHRONIZE_CACHE;
rq->cmd_len = 10;
}
static void sd_rescan(struct device *dev)
{
struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
if (sdkp) {
sd_revalidate_disk(sdkp->disk);
scsi_disk_put(sdkp);
}
}
#ifdef CONFIG_COMPAT
/*
* This gets directly called from VFS. When the ioctl
* is not recognized we go back to the other translation paths.
*/
static long sd_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct block_device *bdev = file->f_dentry->d_inode->i_bdev;
struct gendisk *disk = bdev->bd_disk;
struct scsi_device *sdev = scsi_disk(disk)->device;
/*
* If we are in the middle of error recovery, don't let anyone
* else try and use this device. Also, if error recovery fails, it
* may try and take the device offline, in which case all further
* access to the device is prohibited.
*/
if (!scsi_block_when_processing_errors(sdev))
return -ENODEV;
if (sdev->host->hostt->compat_ioctl) {
int ret;
ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
return ret;
}
/*
* Let the static ioctl translation table take care of it.
*/
return -ENOIOCTLCMD;
}
#endif
static struct block_device_operations sd_fops = {
.owner = THIS_MODULE,
.open = sd_open,
.release = sd_release,
.ioctl = sd_ioctl,
.getgeo = sd_getgeo,
#ifdef CONFIG_COMPAT
.compat_ioctl = sd_compat_ioctl,
#endif
.media_changed = sd_media_changed,
.revalidate_disk = sd_revalidate_disk,
};
/**
* sd_rw_intr - bottom half handler: called when the lower level
* driver has completed (successfully or otherwise) a scsi command.
* @SCpnt: mid-level's per command structure.
*
* Note: potentially run from within an ISR. Must not block.
**/
static void sd_rw_intr(struct scsi_cmnd * SCpnt)
{
int result = SCpnt->result;
unsigned int xfer_size = SCpnt->request_bufflen;
unsigned int good_bytes = result ? 0 : xfer_size;
u64 start_lba = SCpnt->request->sector;
u64 bad_lba;
struct scsi_sense_hdr sshdr;
int sense_valid = 0;
int sense_deferred = 0;
int info_valid;
if (result) {
sense_valid = scsi_command_normalize_sense(SCpnt, &sshdr);
if (sense_valid)
sense_deferred = scsi_sense_is_deferred(&sshdr);
}
#ifdef CONFIG_SCSI_LOGGING
SCSI_LOG_HLCOMPLETE(1, printk("sd_rw_intr: %s: res=0x%x\n",
SCpnt->request->rq_disk->disk_name, result));
if (sense_valid) {
SCSI_LOG_HLCOMPLETE(1, printk("sd_rw_intr: sb[respc,sk,asc,"
"ascq]=%x,%x,%x,%x\n", sshdr.response_code,
sshdr.sense_key, sshdr.asc, sshdr.ascq));
}
#endif
if (driver_byte(result) != DRIVER_SENSE &&
(!sense_valid || sense_deferred))
goto out;
switch (sshdr.sense_key) {
case HARDWARE_ERROR:
case MEDIUM_ERROR:
if (!blk_fs_request(SCpnt->request))
goto out;
info_valid = scsi_get_sense_info_fld(SCpnt->sense_buffer,
SCSI_SENSE_BUFFERSIZE,
&bad_lba);
if (!info_valid)
goto out;
if (xfer_size <= SCpnt->device->sector_size)
goto out;
switch (SCpnt->device->sector_size) {
case 256:
start_lba <<= 1;
break;
case 512:
break;
case 1024:
start_lba >>= 1;
break;
case 2048:
start_lba >>= 2;
break;
case 4096:
start_lba >>= 3;
break;
default:
/* Print something here with limiting frequency. */
goto out;
break;
}
/* This computation should always be done in terms of
* the resolution of the device's medium.
*/
good_bytes = (bad_lba - start_lba)*SCpnt->device->sector_size;
break;
case RECOVERED_ERROR:
case NO_SENSE:
/* Inform the user, but make sure that it's not treated
* as a hard error.
*/
scsi_print_sense("sd", SCpnt);
SCpnt->result = 0;
memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
good_bytes = xfer_size;
break;
case ILLEGAL_REQUEST:
if (SCpnt->device->use_10_for_rw &&
(SCpnt->cmnd[0] == READ_10 ||
SCpnt->cmnd[0] == WRITE_10))
SCpnt->device->use_10_for_rw = 0;
if (SCpnt->device->use_10_for_ms &&
(SCpnt->cmnd[0] == MODE_SENSE_10 ||
SCpnt->cmnd[0] == MODE_SELECT_10))
SCpnt->device->use_10_for_ms = 0;
break;
default:
break;
}
out:
scsi_io_completion(SCpnt, good_bytes);
}
static int media_not_present(struct scsi_disk *sdkp,
struct scsi_sense_hdr *sshdr)
{
if (!scsi_sense_valid(sshdr))
return 0;
/* not invoked for commands that could return deferred errors */
if (sshdr->sense_key != NOT_READY &&
sshdr->sense_key != UNIT_ATTENTION)
return 0;
if (sshdr->asc != 0x3A) /* medium not present */
return 0;
set_media_not_present(sdkp);
return 1;
}
/*
* spinup disk - called only in sd_revalidate_disk()
*/
static void
sd_spinup_disk(struct scsi_disk *sdkp, char *diskname)
{
unsigned char cmd[10];
unsigned long spintime_expire = 0;
int retries, spintime;
unsigned int the_result;
struct scsi_sense_hdr sshdr;
int sense_valid = 0;
spintime = 0;
/* Spin up drives, as required. Only do this at boot time */
/* Spinup needs to be done for module loads too. */
do {
retries = 0;
do {
cmd[0] = TEST_UNIT_READY;
memset((void *) &cmd[1], 0, 9);
the_result = scsi_execute_req(sdkp->device, cmd,
DMA_NONE, NULL, 0,
&sshdr, SD_TIMEOUT,
SD_MAX_RETRIES);
/*
* If the drive has indicated to us that it
* doesn't have any media in it, don't bother
* with any more polling.
*/
if (media_not_present(sdkp, &sshdr))
return;
if (the_result)
sense_valid = scsi_sense_valid(&sshdr);
retries++;
} while (retries < 3 &&
(!scsi_status_is_good(the_result) ||
((driver_byte(the_result) & DRIVER_SENSE) &&
sense_valid && sshdr.sense_key == UNIT_ATTENTION)));
if ((driver_byte(the_result) & DRIVER_SENSE) == 0) {
/* no sense, TUR either succeeded or failed
* with a status error */
if(!spintime && !scsi_status_is_good(the_result))
printk(KERN_NOTICE "%s: Unit Not Ready, "
"error = 0x%x\n", diskname, the_result);
break;
}
/*
* The device does not want the automatic start to be issued.
*/
if (sdkp->device->no_start_on_add) {
break;
}
/*
* If manual intervention is required, or this is an
* absent USB storage device, a spinup is meaningless.
*/
if (sense_valid &&
sshdr.sense_key == NOT_READY &&
sshdr.asc == 4 && sshdr.ascq == 3) {
break; /* manual intervention required */
/*
* Issue command to spin up drive when not ready
*/
} else if (sense_valid && sshdr.sense_key == NOT_READY) {
if (!spintime) {
printk(KERN_NOTICE "%s: Spinning up disk...",
diskname);
cmd[0] = START_STOP;
cmd[1] = 1; /* Return immediately */
memset((void *) &cmd[2], 0, 8);
cmd[4] = 1; /* Start spin cycle */
scsi_execute_req(sdkp->device, cmd, DMA_NONE,
NULL, 0, &sshdr,
SD_TIMEOUT, SD_MAX_RETRIES);
spintime_expire = jiffies + 100 * HZ;
spintime = 1;
}
/* Wait 1 second for next try */
msleep(1000);
printk(".");
/*
* Wait for USB flash devices with slow firmware.
* Yes, this sense key/ASC combination shouldn't
* occur here. It's characteristic of these devices.
*/
} else if (sense_valid &&
sshdr.sense_key == UNIT_ATTENTION &&
sshdr.asc == 0x28) {
if (!spintime) {
spintime_expire = jiffies + 5 * HZ;
spintime = 1;
}
/* Wait 1 second for next try */
msleep(1000);
} else {
/* we don't understand the sense code, so it's
* probably pointless to loop */
if(!spintime) {
printk(KERN_NOTICE "%s: Unit Not Ready, "
"sense:\n", diskname);
scsi_print_sense_hdr("", &sshdr);
}
break;
}
} while (spintime && time_before_eq(jiffies, spintime_expire));
if (spintime) {
if (scsi_status_is_good(the_result))
printk("ready\n");
else
printk("not responding...\n");
}
}
/*
* read disk capacity
*/
static void
sd_read_capacity(struct scsi_disk *sdkp, char *diskname,
unsigned char *buffer)
{
unsigned char cmd[16];
int the_result, retries;
int sector_size = 0;
int longrc = 0;
struct scsi_sense_hdr sshdr;
int sense_valid = 0;
struct scsi_device *sdp = sdkp->device;
repeat:
retries = 3;
do {
if (longrc) {
memset((void *) cmd, 0, 16);
cmd[0] = SERVICE_ACTION_IN;
cmd[1] = SAI_READ_CAPACITY_16;
cmd[13] = 12;
memset((void *) buffer, 0, 12);
} else {
cmd[0] = READ_CAPACITY;
memset((void *) &cmd[1], 0, 9);
memset((void *) buffer, 0, 8);
}
the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
buffer, longrc ? 12 : 8, &sshdr,
SD_TIMEOUT, SD_MAX_RETRIES);
if (media_not_present(sdkp, &sshdr))
return;
if (the_result)
sense_valid = scsi_sense_valid(&sshdr);
retries--;
} while (the_result && retries);
if (the_result && !longrc) {
printk(KERN_NOTICE "%s : READ CAPACITY failed.\n"
"%s : status=%x, message=%02x, host=%d, driver=%02x \n",
diskname, diskname,
status_byte(the_result),
msg_byte(the_result),
host_byte(the_result),
driver_byte(the_result));
if (driver_byte(the_result) & DRIVER_SENSE)
scsi_print_sense_hdr("sd", &sshdr);
else
printk("%s : sense not available. \n", diskname);
/* Set dirty bit for removable devices if not ready -
* sometimes drives will not report this properly. */
if (sdp->removable &&
sense_valid && sshdr.sense_key == NOT_READY)
sdp->changed = 1;
/* Either no media are present but the drive didn't tell us,
or they are present but the read capacity command fails */
/* sdkp->media_present = 0; -- not always correct */
sdkp->capacity = 0; /* unknown mapped to zero - as usual */
return;
} else if (the_result && longrc) {
/* READ CAPACITY(16) has been failed */
printk(KERN_NOTICE "%s : READ CAPACITY(16) failed.\n"
"%s : status=%x, message=%02x, host=%d, driver=%02x \n",
diskname, diskname,
status_byte(the_result),
msg_byte(the_result),
host_byte(the_result),
driver_byte(the_result));
printk(KERN_NOTICE "%s : use 0xffffffff as device size\n",
diskname);
sdkp->capacity = 1 + (sector_t) 0xffffffff;
goto got_data;
}
if (!longrc) {
sector_size = (buffer[4] << 24) |
(buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
if (buffer[0] == 0xff && buffer[1] == 0xff &&
buffer[2] == 0xff && buffer[3] == 0xff) {
if(sizeof(sdkp->capacity) > 4) {
printk(KERN_NOTICE "%s : very big device. try to use"
" READ CAPACITY(16).\n", diskname);
longrc = 1;
goto repeat;
}
printk(KERN_ERR "%s: too big for this kernel. Use a "
"kernel compiled with support for large block "
"devices.\n", diskname);
sdkp->capacity = 0;
goto got_data;
}
sdkp->capacity = 1 + (((sector_t)buffer[0] << 24) |
(buffer[1] << 16) |
(buffer[2] << 8) |
buffer[3]);
} else {
sdkp->capacity = 1 + (((u64)buffer[0] << 56) |
((u64)buffer[1] << 48) |
((u64)buffer[2] << 40) |
((u64)buffer[3] << 32) |
((sector_t)buffer[4] << 24) |
((sector_t)buffer[5] << 16) |
((sector_t)buffer[6] << 8) |
(sector_t)buffer[7]);
sector_size = (buffer[8] << 24) |
(buffer[9] << 16) | (buffer[10] << 8) | buffer[11];
}
/* Some devices return the total number of sectors, not the
* highest sector number. Make the necessary adjustment. */
if (sdp->fix_capacity)
--sdkp->capacity;
got_data:
if (sector_size == 0) {
sector_size = 512;
printk(KERN_NOTICE "%s : sector size 0 reported, "
"assuming 512.\n", diskname);
}
if (sector_size != 512 &&
sector_size != 1024 &&
sector_size != 2048 &&
sector_size != 4096 &&
sector_size != 256) {
printk(KERN_NOTICE "%s : unsupported sector size "
"%d.\n", diskname, sector_size);
/*
* The user might want to re-format the drive with
* a supported sectorsize. Once this happens, it
* would be relatively trivial to set the thing up.
* For this reason, we leave the thing in the table.
*/
sdkp->capacity = 0;
/*
* set a bogus sector size so the normal read/write
* logic in the block layer will eventually refuse any
* request on this device without tripping over power
* of two sector size assumptions
*/
sector_size = 512;
}
{
/*
* The msdos fs needs to know the hardware sector size
* So I have created this table. See ll_rw_blk.c
* Jacques Gelinas (Jacques@solucorp.qc.ca)
*/
int hard_sector = sector_size;
sector_t sz = (sdkp->capacity/2) * (hard_sector/256);
request_queue_t *queue = sdp->request_queue;
sector_t mb = sz;
blk_queue_hardsect_size(queue, hard_sector);
/* avoid 64-bit division on 32-bit platforms */
sector_div(sz, 625);
mb -= sz - 974;
sector_div(mb, 1950);
printk(KERN_NOTICE "SCSI device %s: "
"%llu %d-byte hdwr sectors (%llu MB)\n",
diskname, (unsigned long long)sdkp->capacity,
hard_sector, (unsigned long long)mb);
}
/* Rescale capacity to 512-byte units */
if (sector_size == 4096)
sdkp->capacity <<= 3;
else if (sector_size == 2048)
sdkp->capacity <<= 2;
else if (sector_size == 1024)
sdkp->capacity <<= 1;
else if (sector_size == 256)
sdkp->capacity >>= 1;
sdkp->device->sector_size = sector_size;
}
/* called with buffer of length 512 */
static inline int
sd_do_mode_sense(struct scsi_device *sdp, int dbd, int modepage,
unsigned char *buffer, int len, struct scsi_mode_data *data,
struct scsi_sense_hdr *sshdr)
{
return scsi_mode_sense(sdp, dbd, modepage, buffer, len,
SD_TIMEOUT, SD_MAX_RETRIES, data,
sshdr);
}
/*
* read write protect setting, if possible - called only in sd_revalidate_disk()
* called with buffer of length SD_BUF_SIZE
*/
static void
sd_read_write_protect_flag(struct scsi_disk *sdkp, char *diskname,
unsigned char *buffer)
{
int res;
struct scsi_device *sdp = sdkp->device;
struct scsi_mode_data data;
set_disk_ro(sdkp->disk, 0);
if (sdp->skip_ms_page_3f) {
printk(KERN_NOTICE "%s: assuming Write Enabled\n", diskname);
return;
}
if (sdp->use_192_bytes_for_3f) {
res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 192, &data, NULL);
} else {
/*
* First attempt: ask for all pages (0x3F), but only 4 bytes.
* We have to start carefully: some devices hang if we ask
* for more than is available.
*/
res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 4, &data, NULL);
/*
* Second attempt: ask for page 0 When only page 0 is
* implemented, a request for page 3F may return Sense Key
* 5: Illegal Request, Sense Code 24: Invalid field in
* CDB.
*/
if (!scsi_status_is_good(res))
res = sd_do_mode_sense(sdp, 0, 0, buffer, 4, &data, NULL);
/*
* Third attempt: ask 255 bytes, as we did earlier.
*/
if (!scsi_status_is_good(res))
res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 255,
&data, NULL);
}
if (!scsi_status_is_good(res)) {
printk(KERN_WARNING
"%s: test WP failed, assume Write Enabled\n", diskname);
} else {
sdkp->write_prot = ((data.device_specific & 0x80) != 0);
set_disk_ro(sdkp->disk, sdkp->write_prot);
printk(KERN_NOTICE "%s: Write Protect is %s\n", diskname,
sdkp->write_prot ? "on" : "off");
printk(KERN_DEBUG "%s: Mode Sense: %02x %02x %02x %02x\n",
diskname, buffer[0], buffer[1], buffer[2], buffer[3]);
}
}
/*
* sd_read_cache_type - called only from sd_revalidate_disk()
* called with buffer of length SD_BUF_SIZE
*/
static void
sd_read_cache_type(struct scsi_disk *sdkp, char *diskname,
unsigned char *buffer)
{
int len = 0, res;
struct scsi_device *sdp = sdkp->device;
int dbd;
int modepage;
struct scsi_mode_data data;
struct scsi_sense_hdr sshdr;
if (sdp->skip_ms_page_8)
goto defaults;
if (sdp->type == TYPE_RBC) {
modepage = 6;
dbd = 8;
} else {
modepage = 8;
dbd = 0;
}
/* cautiously ask */
res = sd_do_mode_sense(sdp, dbd, modepage, buffer, 4, &data, &sshdr);
if (!scsi_status_is_good(res))
goto bad_sense;
if (!data.header_length) {
modepage = 6;
printk(KERN_ERR "%s: missing header in MODE_SENSE response\n",
diskname);
}
/* that went OK, now ask for the proper length */
len = data.length;
/*
* We're only interested in the first three bytes, actually.
* But the data cache page is defined for the first 20.
*/
if (len < 3)
goto bad_sense;
if (len > 20)
len = 20;
/* Take headers and block descriptors into account */
len += data.header_length + data.block_descriptor_length;
if (len > SD_BUF_SIZE)
goto bad_sense;
/* Get the data */
res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr);
if (scsi_status_is_good(res)) {
int ct = 0;
int offset = data.header_length + data.block_descriptor_length;
if (offset >= SD_BUF_SIZE - 2) {
printk(KERN_ERR "%s: malformed MODE SENSE response",
diskname);
goto defaults;
}
if ((buffer[offset] & 0x3f) != modepage) {
printk(KERN_ERR "%s: got wrong page\n", diskname);
goto defaults;
}
if (modepage == 8) {
sdkp->WCE = ((buffer[offset + 2] & 0x04) != 0);
sdkp->RCD = ((buffer[offset + 2] & 0x01) != 0);
} else {
sdkp->WCE = ((buffer[offset + 2] & 0x01) == 0);
sdkp->RCD = 0;
}
sdkp->DPOFUA = (data.device_specific & 0x10) != 0;
if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw) {
printk(KERN_NOTICE "SCSI device %s: uses "
"READ/WRITE(6), disabling FUA\n", diskname);
sdkp->DPOFUA = 0;
}
ct = sdkp->RCD + 2*sdkp->WCE;
printk(KERN_NOTICE "SCSI device %s: drive cache: %s%s\n",
diskname, sd_cache_types[ct],
sdkp->DPOFUA ? " w/ FUA" : "");
return;
}
bad_sense:
if (scsi_sense_valid(&sshdr) &&
sshdr.sense_key == ILLEGAL_REQUEST &&
sshdr.asc == 0x24 && sshdr.ascq == 0x0)
printk(KERN_NOTICE "%s: cache data unavailable\n",
diskname); /* Invalid field in CDB */
else
printk(KERN_ERR "%s: asking for cache data failed\n",
diskname);
defaults:
printk(KERN_ERR "%s: assuming drive cache: write through\n",
diskname);
sdkp->WCE = 0;
sdkp->RCD = 0;
sdkp->DPOFUA = 0;
}
/**
* sd_revalidate_disk - called the first time a new disk is seen,
* performs disk spin up, read_capacity, etc.
* @disk: struct gendisk we care about
**/
static int sd_revalidate_disk(struct gendisk *disk)
{
struct scsi_disk *sdkp = scsi_disk(disk);
struct scsi_device *sdp = sdkp->device;
unsigned char *buffer;
unsigned ordered;
SCSI_LOG_HLQUEUE(3, printk("sd_revalidate_disk: disk=%s\n", disk->disk_name));
/*
* If the device is offline, don't try and read capacity or any
* of the other niceties.
*/
if (!scsi_device_online(sdp))
goto out;
buffer = kmalloc(SD_BUF_SIZE, GFP_KERNEL | __GFP_DMA);
if (!buffer) {
printk(KERN_WARNING "(sd_revalidate_disk:) Memory allocation "
"failure.\n");
goto out;
}
/* defaults, until the device tells us otherwise */
sdp->sector_size = 512;
sdkp->capacity = 0;
sdkp->media_present = 1;
sdkp->write_prot = 0;
sdkp->WCE = 0;
sdkp->RCD = 0;
sd_spinup_disk(sdkp, disk->disk_name);
/*
* Without media there is no reason to ask; moreover, some devices
* react badly if we do.
*/
if (sdkp->media_present) {
sd_read_capacity(sdkp, disk->disk_name, buffer);
sd_read_write_protect_flag(sdkp, disk->disk_name, buffer);
sd_read_cache_type(sdkp, disk->disk_name, buffer);
}
/*
* We now have all cache related info, determine how we deal
* with ordered requests. Note that as the current SCSI
* dispatch function can alter request order, we cannot use
* QUEUE_ORDERED_TAG_* even when ordered tag is supported.
*/
if (sdkp->WCE)
ordered = sdkp->DPOFUA
? QUEUE_ORDERED_DRAIN_FUA : QUEUE_ORDERED_DRAIN_FLUSH;
else
ordered = QUEUE_ORDERED_DRAIN;
blk_queue_ordered(sdkp->disk->queue, ordered, sd_prepare_flush);
set_capacity(disk, sdkp->capacity);
kfree(buffer);
out:
return 0;
}
/**
* sd_probe - called during driver initialization and whenever a
* new scsi device is attached to the system. It is called once
* for each scsi device (not just disks) present.
* @dev: pointer to device object
*
* Returns 0 if successful (or not interested in this scsi device
* (e.g. scanner)); 1 when there is an error.
*
* Note: this function is invoked from the scsi mid-level.
* This function sets up the mapping between a given
* <host,channel,id,lun> (found in sdp) and new device name
* (e.g. /dev/sda). More precisely it is the block device major
* and minor number that is chosen here.
*
* Assume sd_attach is not re-entrant (for time being)
* Also think about sd_attach() and sd_remove() running coincidentally.
**/
static int sd_probe(struct device *dev)
{
struct scsi_device *sdp = to_scsi_device(dev);
struct scsi_disk *sdkp;
struct gendisk *gd;
u32 index;
int error;
error = -ENODEV;
if (sdp->type != TYPE_DISK && sdp->type != TYPE_MOD && sdp->type != TYPE_RBC)
goto out;
SCSI_LOG_HLQUEUE(3, sdev_printk(KERN_INFO, sdp,
"sd_attach\n"));
error = -ENOMEM;
sdkp = kzalloc(sizeof(*sdkp), GFP_KERNEL);
if (!sdkp)
goto out;
gd = alloc_disk(16);
if (!gd)
goto out_free;
if (!idr_pre_get(&sd_index_idr, GFP_KERNEL))
goto out_put;
spin_lock(&sd_index_lock);
error = idr_get_new(&sd_index_idr, NULL, &index);
spin_unlock(&sd_index_lock);
if (index >= SD_MAX_DISKS)
error = -EBUSY;
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;
sdkp->index = index;
sdkp->openers = 0;
if (!sdp->timeout) {
if (sdp->type != TYPE_MOD)
sdp->timeout = SD_TIMEOUT;
else
sdp->timeout = SD_MOD_TIMEOUT;
}
gd->major = sd_major((index & 0xf0) >> 4);
gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00);
gd->minors = 16;
gd->fops = &sd_fops;
if (index < 26) {
sprintf(gd->disk_name, "sd%c", 'a' + index % 26);
} else if (index < (26 + 1) * 26) {
sprintf(gd->disk_name, "sd%c%c",
'a' + index / 26 - 1,'a' + index % 26);
} else {
const unsigned int m1 = (index / 26 - 1) / 26 - 1;
const unsigned int m2 = (index / 26 - 1) % 26;
const unsigned int m3 = index % 26;
sprintf(gd->disk_name, "sd%c%c%c",
'a' + m1, 'a' + m2, 'a' + m3);
}
gd->private_data = &sdkp->driver;
gd->queue = sdkp->device->request_queue;
sd_revalidate_disk(gd);
gd->driverfs_dev = &sdp->sdev_gendev;
gd->flags = GENHD_FL_DRIVERFS;
if (sdp->removable)
gd->flags |= GENHD_FL_REMOVABLE;
dev_set_drvdata(dev, sdkp);
add_disk(gd);
sdev_printk(KERN_NOTICE, sdp, "Attached scsi %sdisk %s\n",
sdp->removable ? "removable " : "", gd->disk_name);
return 0;
out_put:
put_disk(gd);
out_free:
kfree(sdkp);
out:
return error;
}
/**
* sd_remove - called whenever a scsi disk (previously recognized by
* sd_probe) is detached from the system. It is called (potentially
* multiple times) during sd module unload.
* @sdp: pointer to mid level scsi device object
*
* Note: this function is invoked from the scsi mid-level.
* This function potentially frees up a device name (e.g. /dev/sdc)
* that could be re-used by a subsequent sd_probe().
* This function is not called when the built-in sd driver is "exit-ed".
**/
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);
class_device_put(&sdkp->cdev);
mutex_unlock(&sd_ref_mutex);
return 0;
}
/**
* scsi_disk_release - Called to free the scsi_disk structure
* @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 class_device_put().
**/
static void scsi_disk_release(struct class_device *cdev)
{
struct scsi_disk *sdkp = to_scsi_disk(cdev);
struct gendisk *disk = sdkp->disk;
spin_lock(&sd_index_lock);
idr_remove(&sd_index_idr, sdkp->index);
spin_unlock(&sd_index_lock);
disk->private_data = NULL;
put_disk(disk);
put_device(&sdkp->device->sdev_gendev);
kfree(sdkp);
}
/*
* Send a SYNCHRONIZE CACHE instruction down to the device through
* the normal SCSI command structure. Wait for the command to
* complete.
*/
static void sd_shutdown(struct device *dev)
{
struct scsi_device *sdp = to_scsi_device(dev);
struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
if (!sdkp)
return; /* this can happen */
if (sdkp->WCE) {
printk(KERN_NOTICE "Synchronizing SCSI cache for disk %s: \n",
sdkp->disk->disk_name);
sd_sync_cache(sdp);
}
scsi_disk_put(sdkp);
}
/**
* init_sd - entry point for this driver (both when built in or when
* a module).
*
* Note: this function registers this driver with the scsi mid-level.
**/
static int __init init_sd(void)
{
int majors = 0, i, err;
SCSI_LOG_HLQUEUE(3, printk("init_sd: sd driver entry point\n"));
for (i = 0; i < SD_MAJORS; i++)
if (register_blkdev(sd_major(i), "sd") == 0)
majors++;
if (!majors)
return -ENODEV;
err = class_register(&sd_disk_class);
if (err)
goto err_out;
err = scsi_register_driver(&sd_template.gendrv);
if (err)
goto err_out_class;
return 0;
err_out_class:
class_unregister(&sd_disk_class);
err_out:
for (i = 0; i < SD_MAJORS; i++)
unregister_blkdev(sd_major(i), "sd");
return err;
}
/**
* exit_sd - exit point for this driver (when it is a module).
*
* Note: this function unregisters this driver from the scsi mid-level.
**/
static void __exit exit_sd(void)
{
int i;
SCSI_LOG_HLQUEUE(3, printk("exit_sd: exiting sd driver\n"));
scsi_unregister_driver(&sd_template.gendrv);
class_unregister(&sd_disk_class);
for (i = 0; i < SD_MAJORS; i++)
unregister_blkdev(sd_major(i), "sd");
}
module_init(init_sd);
module_exit(exit_sd);
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