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sg.c
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sg.c
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/*
* History:
* Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
* to allow user process control of SCSI devices.
* Development Sponsored by Killy Corp. NY NY
*
* Original driver (sg.c):
* Copyright (C) 1992 Lawrence Foard
* Version 2 and 3 extensions to driver:
* Copyright (C) 1998 - 2005 Douglas Gilbert
*
* Modified 19-JAN-1998 Richard Gooch <rgooch@atnf.csiro.au> Devfs support
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
*/
static int sg_version_num = 30534; /* 2 digits for each component */
#define SG_VERSION_STR "3.5.34"
/*
* D. P. Gilbert (dgilbert@interlog.com, dougg@triode.net.au), notes:
* - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
* the kernel/module needs to be built with CONFIG_SCSI_LOGGING
* (otherwise the macros compile to empty statements).
*
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/mtio.h>
#include <linux/ioctl.h>
#include <linux/slab.h>
#include <linux/fcntl.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <linux/moduleparam.h>
#include <linux/cdev.h>
#include <linux/idr.h>
#include <linux/seq_file.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/blktrace_api.h>
#include <linux/mutex.h>
#include <linux/ratelimit.h>
#include "scsi.h"
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_driver.h>
#include <scsi/scsi_ioctl.h>
#include <scsi/sg.h>
#include "scsi_logging.h"
#ifdef CONFIG_SCSI_PROC_FS
#include <linux/proc_fs.h>
static char *sg_version_date = "20061027";
static int sg_proc_init(void);
static void sg_proc_cleanup(void);
#endif
#define SG_ALLOW_DIO_DEF 0
#define SG_MAX_DEVS 32768
/*
* Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
* Then when using 32 bit integers x * m may overflow during the calculation.
* Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
* calculates the same, but prevents the overflow when both m and d
* are "small" numbers (like HZ and USER_HZ).
* Of course an overflow is inavoidable if the result of muldiv doesn't fit
* in 32 bits.
*/
#define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
#define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
int sg_big_buff = SG_DEF_RESERVED_SIZE;
/* N.B. This variable is readable and writeable via
/proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
of this size (or less if there is not enough memory) will be reserved
for use by this file descriptor. [Deprecated usage: this variable is also
readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
the kernel (i.e. it is not a module).] */
static int def_reserved_size = -1; /* picks up init parameter */
static int sg_allow_dio = SG_ALLOW_DIO_DEF;
static int scatter_elem_sz = SG_SCATTER_SZ;
static int scatter_elem_sz_prev = SG_SCATTER_SZ;
#define SG_SECTOR_SZ 512
static int sg_add(struct device *, struct class_interface *);
static void sg_remove(struct device *, struct class_interface *);
static DEFINE_SPINLOCK(sg_open_exclusive_lock);
static DEFINE_IDR(sg_index_idr);
static DEFINE_RWLOCK(sg_index_lock); /* Also used to lock
file descriptor list for device */
static struct class_interface sg_interface = {
.add_dev = sg_add,
.remove_dev = sg_remove,
};
typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
unsigned bufflen; /* Size of (aggregate) data buffer */
struct page **pages;
int page_order;
char dio_in_use; /* 0->indirect IO (or mmap), 1->dio */
unsigned char cmd_opcode; /* first byte of command */
} Sg_scatter_hold;
struct sg_device; /* forward declarations */
struct sg_fd;
typedef struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */
struct sg_request *nextrp; /* NULL -> tail request (slist) */
struct sg_fd *parentfp; /* NULL -> not in use */
Sg_scatter_hold data; /* hold buffer, perhaps scatter list */
sg_io_hdr_t header; /* scsi command+info, see <scsi/sg.h> */
unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
char res_used; /* 1 -> using reserve buffer, 0 -> not ... */
char orphan; /* 1 -> drop on sight, 0 -> normal */
char sg_io_owned; /* 1 -> packet belongs to SG_IO */
/* done protected by rq_list_lock */
char done; /* 0->before bh, 1->before read, 2->read */
struct request *rq;
struct bio *bio;
struct execute_work ew;
} Sg_request;
typedef struct sg_fd { /* holds the state of a file descriptor */
/* sfd_siblings is protected by sg_index_lock */
struct list_head sfd_siblings;
struct sg_device *parentdp; /* owning device */
wait_queue_head_t read_wait; /* queue read until command done */
rwlock_t rq_list_lock; /* protect access to list in req_arr */
int timeout; /* defaults to SG_DEFAULT_TIMEOUT */
int timeout_user; /* defaults to SG_DEFAULT_TIMEOUT_USER */
Sg_scatter_hold reserve; /* buffer held for this file descriptor */
unsigned save_scat_len; /* original length of trunc. scat. element */
Sg_request *headrp; /* head of request slist, NULL->empty */
struct fasync_struct *async_qp; /* used by asynchronous notification */
Sg_request req_arr[SG_MAX_QUEUE]; /* used as singly-linked list */
char low_dma; /* as in parent but possibly overridden to 1 */
char force_packid; /* 1 -> pack_id input to read(), 0 -> ignored */
char cmd_q; /* 1 -> allow command queuing, 0 -> don't */
char next_cmd_len; /* 0 -> automatic (def), >0 -> use on next write() */
char keep_orphan; /* 0 -> drop orphan (def), 1 -> keep for read() */
char mmap_called; /* 0 -> mmap() never called on this fd */
struct kref f_ref;
struct execute_work ew;
} Sg_fd;
typedef struct sg_device { /* holds the state of each scsi generic device */
struct scsi_device *device;
wait_queue_head_t o_excl_wait; /* queue open() when O_EXCL in use */
int sg_tablesize; /* adapter's max scatter-gather table size */
u32 index; /* device index number */
/* sfds is protected by sg_index_lock */
struct list_head sfds;
volatile char detached; /* 0->attached, 1->detached pending removal */
/* exclude protected by sg_open_exclusive_lock */
char exclude; /* opened for exclusive access */
char sgdebug; /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
struct gendisk *disk;
struct cdev * cdev; /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
struct kref d_ref;
} Sg_device;
/* tasklet or soft irq callback */
static void sg_rq_end_io(struct request *rq, int uptodate);
static int sg_start_req(Sg_request *srp, unsigned char *cmd);
static int sg_finish_rem_req(Sg_request * srp);
static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
Sg_request * srp);
static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
const char __user *buf, size_t count, int blocking,
int read_only, int sg_io_owned, Sg_request **o_srp);
static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
unsigned char *cmnd, int timeout, int blocking);
static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
static void sg_remove_scat(Sg_scatter_hold * schp);
static void sg_build_reserve(Sg_fd * sfp, int req_size);
static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
static void sg_remove_sfp(struct kref *);
static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
static Sg_request *sg_add_request(Sg_fd * sfp);
static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
static int sg_res_in_use(Sg_fd * sfp);
static Sg_device *sg_get_dev(int dev);
static void sg_put_dev(Sg_device *sdp);
#define SZ_SG_HEADER sizeof(struct sg_header)
#define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
#define SZ_SG_IOVEC sizeof(sg_iovec_t)
#define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
static int sg_allow_access(struct file *filp, unsigned char *cmd)
{
struct sg_fd *sfp = filp->private_data;
if (sfp->parentdp->device->type == TYPE_SCANNER)
return 0;
return blk_verify_command(cmd, filp->f_mode & FMODE_WRITE);
}
static int get_exclude(Sg_device *sdp)
{
unsigned long flags;
int ret;
spin_lock_irqsave(&sg_open_exclusive_lock, flags);
ret = sdp->exclude;
spin_unlock_irqrestore(&sg_open_exclusive_lock, flags);
return ret;
}
static int set_exclude(Sg_device *sdp, char val)
{
unsigned long flags;
spin_lock_irqsave(&sg_open_exclusive_lock, flags);
sdp->exclude = val;
spin_unlock_irqrestore(&sg_open_exclusive_lock, flags);
return val;
}
static int sfds_list_empty(Sg_device *sdp)
{
unsigned long flags;
int ret;
read_lock_irqsave(&sg_index_lock, flags);
ret = list_empty(&sdp->sfds);
read_unlock_irqrestore(&sg_index_lock, flags);
return ret;
}
static int
sg_open(struct inode *inode, struct file *filp)
{
int dev = iminor(inode);
int flags = filp->f_flags;
struct request_queue *q;
Sg_device *sdp;
Sg_fd *sfp;
int res;
int retval;
nonseekable_open(inode, filp);
SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
sdp = sg_get_dev(dev);
if (IS_ERR(sdp)) {
retval = PTR_ERR(sdp);
sdp = NULL;
goto sg_put;
}
/* This driver's module count bumped by fops_get in <linux/fs.h> */
/* Prevent the device driver from vanishing while we sleep */
retval = scsi_device_get(sdp->device);
if (retval)
goto sg_put;
retval = scsi_autopm_get_device(sdp->device);
if (retval)
goto sdp_put;
if (!((flags & O_NONBLOCK) ||
scsi_block_when_processing_errors(sdp->device))) {
retval = -ENXIO;
/* we are in error recovery for this device */
goto error_out;
}
if (flags & O_EXCL) {
if (O_RDONLY == (flags & O_ACCMODE)) {
retval = -EPERM; /* Can't lock it with read only access */
goto error_out;
}
if (!sfds_list_empty(sdp) && (flags & O_NONBLOCK)) {
retval = -EBUSY;
goto error_out;
}
res = wait_event_interruptible(sdp->o_excl_wait,
((!sfds_list_empty(sdp) || get_exclude(sdp)) ? 0 : set_exclude(sdp, 1)));
if (res) {
retval = res; /* -ERESTARTSYS because signal hit process */
goto error_out;
}
} else if (get_exclude(sdp)) { /* some other fd has an exclusive lock on dev */
if (flags & O_NONBLOCK) {
retval = -EBUSY;
goto error_out;
}
res = wait_event_interruptible(sdp->o_excl_wait, !get_exclude(sdp));
if (res) {
retval = res; /* -ERESTARTSYS because signal hit process */
goto error_out;
}
}
if (sdp->detached) {
retval = -ENODEV;
goto error_out;
}
if (sfds_list_empty(sdp)) { /* no existing opens on this device */
sdp->sgdebug = 0;
q = sdp->device->request_queue;
sdp->sg_tablesize = queue_max_segments(q);
}
if ((sfp = sg_add_sfp(sdp, dev)))
filp->private_data = sfp;
else {
if (flags & O_EXCL) {
set_exclude(sdp, 0); /* undo if error */
wake_up_interruptible(&sdp->o_excl_wait);
}
retval = -ENOMEM;
goto error_out;
}
retval = 0;
error_out:
if (retval) {
scsi_autopm_put_device(sdp->device);
sdp_put:
scsi_device_put(sdp->device);
}
sg_put:
if (sdp)
sg_put_dev(sdp);
return retval;
}
/* Following function was formerly called 'sg_close' */
static int
sg_release(struct inode *inode, struct file *filp)
{
Sg_device *sdp;
Sg_fd *sfp;
if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
return -ENXIO;
SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
set_exclude(sdp, 0);
wake_up_interruptible(&sdp->o_excl_wait);
scsi_autopm_put_device(sdp->device);
kref_put(&sfp->f_ref, sg_remove_sfp);
return 0;
}
static ssize_t
sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
{
Sg_device *sdp;
Sg_fd *sfp;
Sg_request *srp;
int req_pack_id = -1;
sg_io_hdr_t *hp;
struct sg_header *old_hdr = NULL;
int retval = 0;
if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
return -ENXIO;
SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
sdp->disk->disk_name, (int) count));
if (!access_ok(VERIFY_WRITE, buf, count))
return -EFAULT;
if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
if (!old_hdr)
return -ENOMEM;
if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
retval = -EFAULT;
goto free_old_hdr;
}
if (old_hdr->reply_len < 0) {
if (count >= SZ_SG_IO_HDR) {
sg_io_hdr_t *new_hdr;
new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
if (!new_hdr) {
retval = -ENOMEM;
goto free_old_hdr;
}
retval =__copy_from_user
(new_hdr, buf, SZ_SG_IO_HDR);
req_pack_id = new_hdr->pack_id;
kfree(new_hdr);
if (retval) {
retval = -EFAULT;
goto free_old_hdr;
}
}
} else
req_pack_id = old_hdr->pack_id;
}
srp = sg_get_rq_mark(sfp, req_pack_id);
if (!srp) { /* now wait on packet to arrive */
if (sdp->detached) {
retval = -ENODEV;
goto free_old_hdr;
}
if (filp->f_flags & O_NONBLOCK) {
retval = -EAGAIN;
goto free_old_hdr;
}
retval = wait_event_interruptible(sfp->read_wait,
(sdp->detached ||
(srp = sg_get_rq_mark(sfp, req_pack_id))));
if (sdp->detached) {
retval = -ENODEV;
goto free_old_hdr;
}
if (retval) {
/* -ERESTARTSYS as signal hit process */
goto free_old_hdr;
}
}
if (srp->header.interface_id != '\0') {
retval = sg_new_read(sfp, buf, count, srp);
goto free_old_hdr;
}
hp = &srp->header;
if (old_hdr == NULL) {
old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
if (! old_hdr) {
retval = -ENOMEM;
goto free_old_hdr;
}
}
memset(old_hdr, 0, SZ_SG_HEADER);
old_hdr->reply_len = (int) hp->timeout;
old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
old_hdr->pack_id = hp->pack_id;
old_hdr->twelve_byte =
((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
old_hdr->target_status = hp->masked_status;
old_hdr->host_status = hp->host_status;
old_hdr->driver_status = hp->driver_status;
if ((CHECK_CONDITION & hp->masked_status) ||
(DRIVER_SENSE & hp->driver_status))
memcpy(old_hdr->sense_buffer, srp->sense_b,
sizeof (old_hdr->sense_buffer));
switch (hp->host_status) {
/* This setup of 'result' is for backward compatibility and is best
ignored by the user who should use target, host + driver status */
case DID_OK:
case DID_PASSTHROUGH:
case DID_SOFT_ERROR:
old_hdr->result = 0;
break;
case DID_NO_CONNECT:
case DID_BUS_BUSY:
case DID_TIME_OUT:
old_hdr->result = EBUSY;
break;
case DID_BAD_TARGET:
case DID_ABORT:
case DID_PARITY:
case DID_RESET:
case DID_BAD_INTR:
old_hdr->result = EIO;
break;
case DID_ERROR:
old_hdr->result = (srp->sense_b[0] == 0 &&
hp->masked_status == GOOD) ? 0 : EIO;
break;
default:
old_hdr->result = EIO;
break;
}
/* Now copy the result back to the user buffer. */
if (count >= SZ_SG_HEADER) {
if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
retval = -EFAULT;
goto free_old_hdr;
}
buf += SZ_SG_HEADER;
if (count > old_hdr->reply_len)
count = old_hdr->reply_len;
if (count > SZ_SG_HEADER) {
if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
retval = -EFAULT;
goto free_old_hdr;
}
}
} else
count = (old_hdr->result == 0) ? 0 : -EIO;
sg_finish_rem_req(srp);
retval = count;
free_old_hdr:
kfree(old_hdr);
return retval;
}
static ssize_t
sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
{
sg_io_hdr_t *hp = &srp->header;
int err = 0;
int len;
if (count < SZ_SG_IO_HDR) {
err = -EINVAL;
goto err_out;
}
hp->sb_len_wr = 0;
if ((hp->mx_sb_len > 0) && hp->sbp) {
if ((CHECK_CONDITION & hp->masked_status) ||
(DRIVER_SENSE & hp->driver_status)) {
int sb_len = SCSI_SENSE_BUFFERSIZE;
sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
len = 8 + (int) srp->sense_b[7]; /* Additional sense length field */
len = (len > sb_len) ? sb_len : len;
if (copy_to_user(hp->sbp, srp->sense_b, len)) {
err = -EFAULT;
goto err_out;
}
hp->sb_len_wr = len;
}
}
if (hp->masked_status || hp->host_status || hp->driver_status)
hp->info |= SG_INFO_CHECK;
if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
err = -EFAULT;
goto err_out;
}
err_out:
err = sg_finish_rem_req(srp);
return (0 == err) ? count : err;
}
static ssize_t
sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
{
int mxsize, cmd_size, k;
int input_size, blocking;
unsigned char opcode;
Sg_device *sdp;
Sg_fd *sfp;
Sg_request *srp;
struct sg_header old_hdr;
sg_io_hdr_t *hp;
unsigned char cmnd[MAX_COMMAND_SIZE];
if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
return -ENXIO;
SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
sdp->disk->disk_name, (int) count));
if (sdp->detached)
return -ENODEV;
if (!((filp->f_flags & O_NONBLOCK) ||
scsi_block_when_processing_errors(sdp->device)))
return -ENXIO;
if (!access_ok(VERIFY_READ, buf, count))
return -EFAULT; /* protects following copy_from_user()s + get_user()s */
if (count < SZ_SG_HEADER)
return -EIO;
if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
return -EFAULT;
blocking = !(filp->f_flags & O_NONBLOCK);
if (old_hdr.reply_len < 0)
return sg_new_write(sfp, filp, buf, count,
blocking, 0, 0, NULL);
if (count < (SZ_SG_HEADER + 6))
return -EIO; /* The minimum scsi command length is 6 bytes. */
if (!(srp = sg_add_request(sfp))) {
SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
return -EDOM;
}
buf += SZ_SG_HEADER;
__get_user(opcode, buf);
if (sfp->next_cmd_len > 0) {
if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
sfp->next_cmd_len = 0;
sg_remove_request(sfp, srp);
return -EIO;
}
cmd_size = sfp->next_cmd_len;
sfp->next_cmd_len = 0; /* reset so only this write() effected */
} else {
cmd_size = COMMAND_SIZE(opcode); /* based on SCSI command group */
if ((opcode >= 0xc0) && old_hdr.twelve_byte)
cmd_size = 12;
}
SCSI_LOG_TIMEOUT(4, printk(
"sg_write: scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
/* Determine buffer size. */
input_size = count - cmd_size;
mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
mxsize -= SZ_SG_HEADER;
input_size -= SZ_SG_HEADER;
if (input_size < 0) {
sg_remove_request(sfp, srp);
return -EIO; /* User did not pass enough bytes for this command. */
}
hp = &srp->header;
hp->interface_id = '\0'; /* indicator of old interface tunnelled */
hp->cmd_len = (unsigned char) cmd_size;
hp->iovec_count = 0;
hp->mx_sb_len = 0;
if (input_size > 0)
hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
else
hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
hp->dxfer_len = mxsize;
if (hp->dxfer_direction == SG_DXFER_TO_DEV)
hp->dxferp = (char __user *)buf + cmd_size;
else
hp->dxferp = NULL;
hp->sbp = NULL;
hp->timeout = old_hdr.reply_len; /* structure abuse ... */
hp->flags = input_size; /* structure abuse ... */
hp->pack_id = old_hdr.pack_id;
hp->usr_ptr = NULL;
if (__copy_from_user(cmnd, buf, cmd_size))
return -EFAULT;
/*
* SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
* but is is possible that the app intended SG_DXFER_TO_DEV, because there
* is a non-zero input_size, so emit a warning.
*/
if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
static char cmd[TASK_COMM_LEN];
if (strcmp(current->comm, cmd)) {
printk_ratelimited(KERN_WARNING
"sg_write: data in/out %d/%d bytes "
"for SCSI command 0x%x-- guessing "
"data in;\n program %s not setting "
"count and/or reply_len properly\n",
old_hdr.reply_len - (int)SZ_SG_HEADER,
input_size, (unsigned int) cmnd[0],
current->comm);
strcpy(cmd, current->comm);
}
}
k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
return (k < 0) ? k : count;
}
static ssize_t
sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
size_t count, int blocking, int read_only, int sg_io_owned,
Sg_request **o_srp)
{
int k;
Sg_request *srp;
sg_io_hdr_t *hp;
unsigned char cmnd[MAX_COMMAND_SIZE];
int timeout;
unsigned long ul_timeout;
if (count < SZ_SG_IO_HDR)
return -EINVAL;
if (!access_ok(VERIFY_READ, buf, count))
return -EFAULT; /* protects following copy_from_user()s + get_user()s */
sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
if (!(srp = sg_add_request(sfp))) {
SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
return -EDOM;
}
srp->sg_io_owned = sg_io_owned;
hp = &srp->header;
if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
sg_remove_request(sfp, srp);
return -EFAULT;
}
if (hp->interface_id != 'S') {
sg_remove_request(sfp, srp);
return -ENOSYS;
}
if (hp->flags & SG_FLAG_MMAP_IO) {
if (hp->dxfer_len > sfp->reserve.bufflen) {
sg_remove_request(sfp, srp);
return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
}
if (hp->flags & SG_FLAG_DIRECT_IO) {
sg_remove_request(sfp, srp);
return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
}
if (sg_res_in_use(sfp)) {
sg_remove_request(sfp, srp);
return -EBUSY; /* reserve buffer already being used */
}
}
ul_timeout = msecs_to_jiffies(srp->header.timeout);
timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
sg_remove_request(sfp, srp);
return -EMSGSIZE;
}
if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
sg_remove_request(sfp, srp);
return -EFAULT; /* protects following copy_from_user()s + get_user()s */
}
if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
sg_remove_request(sfp, srp);
return -EFAULT;
}
if (read_only && sg_allow_access(file, cmnd)) {
sg_remove_request(sfp, srp);
return -EPERM;
}
k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
if (k < 0)
return k;
if (o_srp)
*o_srp = srp;
return count;
}
static int
sg_common_write(Sg_fd * sfp, Sg_request * srp,
unsigned char *cmnd, int timeout, int blocking)
{
int k, data_dir;
Sg_device *sdp = sfp->parentdp;
sg_io_hdr_t *hp = &srp->header;
srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
hp->status = 0;
hp->masked_status = 0;
hp->msg_status = 0;
hp->info = 0;
hp->host_status = 0;
hp->driver_status = 0;
hp->resid = 0;
SCSI_LOG_TIMEOUT(4, printk("sg_common_write: scsi opcode=0x%02x, cmd_size=%d\n",
(int) cmnd[0], (int) hp->cmd_len));
k = sg_start_req(srp, cmnd);
if (k) {
SCSI_LOG_TIMEOUT(1, printk("sg_common_write: start_req err=%d\n", k));
sg_finish_rem_req(srp);
return k; /* probably out of space --> ENOMEM */
}
if (sdp->detached) {
if (srp->bio)
blk_end_request_all(srp->rq, -EIO);
sg_finish_rem_req(srp);
return -ENODEV;
}
switch (hp->dxfer_direction) {
case SG_DXFER_TO_FROM_DEV:
case SG_DXFER_FROM_DEV:
data_dir = DMA_FROM_DEVICE;
break;
case SG_DXFER_TO_DEV:
data_dir = DMA_TO_DEVICE;
break;
case SG_DXFER_UNKNOWN:
data_dir = DMA_BIDIRECTIONAL;
break;
default:
data_dir = DMA_NONE;
break;
}
hp->duration = jiffies_to_msecs(jiffies);
srp->rq->timeout = timeout;
kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
srp->rq, 1, sg_rq_end_io);
return 0;
}
static int srp_done(Sg_fd *sfp, Sg_request *srp)
{
unsigned long flags;
int ret;
read_lock_irqsave(&sfp->rq_list_lock, flags);
ret = srp->done;
read_unlock_irqrestore(&sfp->rq_list_lock, flags);
return ret;
}
static long
sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
{
void __user *p = (void __user *)arg;
int __user *ip = p;
int result, val, read_only;
Sg_device *sdp;
Sg_fd *sfp;
Sg_request *srp;
unsigned long iflags;
if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
return -ENXIO;
SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
sdp->disk->disk_name, (int) cmd_in));
read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
switch (cmd_in) {
case SG_IO:
if (sdp->detached)
return -ENODEV;
if (!scsi_block_when_processing_errors(sdp->device))
return -ENXIO;
if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
return -EFAULT;
result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
1, read_only, 1, &srp);
if (result < 0)
return result;
result = wait_event_interruptible(sfp->read_wait,
(srp_done(sfp, srp) || sdp->detached));
if (sdp->detached)
return -ENODEV;
write_lock_irq(&sfp->rq_list_lock);
if (srp->done) {
srp->done = 2;
write_unlock_irq(&sfp->rq_list_lock);
result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
return (result < 0) ? result : 0;
}
srp->orphan = 1;
write_unlock_irq(&sfp->rq_list_lock);
return result; /* -ERESTARTSYS because signal hit process */
case SG_SET_TIMEOUT:
result = get_user(val, ip);
if (result)
return result;
if (val < 0)
return -EIO;
if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
val = MULDIV (INT_MAX, USER_HZ, HZ);
sfp->timeout_user = val;
sfp->timeout = MULDIV (val, HZ, USER_HZ);
return 0;
case SG_GET_TIMEOUT: /* N.B. User receives timeout as return value */
/* strange ..., for backward compatibility */
return sfp->timeout_user;
case SG_SET_FORCE_LOW_DMA:
result = get_user(val, ip);
if (result)
return result;
if (val) {
sfp->low_dma = 1;
if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
val = (int) sfp->reserve.bufflen;
sg_remove_scat(&sfp->reserve);
sg_build_reserve(sfp, val);
}
} else {
if (sdp->detached)
return -ENODEV;
sfp->low_dma = sdp->device->host->unchecked_isa_dma;
}
return 0;
case SG_GET_LOW_DMA:
return put_user((int) sfp->low_dma, ip);
case SG_GET_SCSI_ID:
if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
return -EFAULT;
else {
sg_scsi_id_t __user *sg_idp = p;
if (sdp->detached)
return -ENODEV;
__put_user((int) sdp->device->host->host_no,
&sg_idp->host_no);
__put_user((int) sdp->device->channel,
&sg_idp->channel);
__put_user((int) sdp->device->id, &sg_idp->scsi_id);
__put_user((int) sdp->device->lun, &sg_idp->lun);
__put_user((int) sdp->device->type, &sg_idp->scsi_type);
__put_user((short) sdp->device->host->cmd_per_lun,
&sg_idp->h_cmd_per_lun);
__put_user((short) sdp->device->queue_depth,
&sg_idp->d_queue_depth);
__put_user(0, &sg_idp->unused[0]);
__put_user(0, &sg_idp->unused[1]);
return 0;
}
case SG_SET_FORCE_PACK_ID:
result = get_user(val, ip);
if (result)
return result;
sfp->force_packid = val ? 1 : 0;
return 0;
case SG_GET_PACK_ID:
if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
return -EFAULT;
read_lock_irqsave(&sfp->rq_list_lock, iflags);
for (srp = sfp->headrp; srp; srp = srp->nextrp) {
if ((1 == srp->done) && (!srp->sg_io_owned)) {
read_unlock_irqrestore(&sfp->rq_list_lock,
iflags);
__put_user(srp->header.pack_id, ip);
return 0;
}
}
read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
__put_user(-1, ip);
return 0;
case SG_GET_NUM_WAITING:
read_lock_irqsave(&sfp->rq_list_lock, iflags);
for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
if ((1 == srp->done) && (!srp->sg_io_owned))
++val;
}
read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
return put_user(val, ip);
case SG_GET_SG_TABLESIZE:
return put_user(sdp->sg_tablesize, ip);
case SG_SET_RESERVED_SIZE:
result = get_user(val, ip);
if (result)
return result;
if (val < 0)
return -EINVAL;
val = min_t(int, val,
queue_max_sectors(sdp->device->request_queue) * 512);
if (val != sfp->reserve.bufflen) {
if (sg_res_in_use(sfp) || sfp->mmap_called)
return -EBUSY;
sg_remove_scat(&sfp->reserve);
sg_build_reserve(sfp, val);
}
return 0;
case SG_GET_RESERVED_SIZE:
val = min_t(int, sfp->reserve.bufflen,
queue_max_sectors(sdp->device->request_queue) * 512);
return put_user(val, ip);
case SG_SET_COMMAND_Q:
result = get_user(val, ip);
if (result)
return result;
sfp->cmd_q = val ? 1 : 0;
return 0;
case SG_GET_COMMAND_Q:
return put_user((int) sfp->cmd_q, ip);
case SG_SET_KEEP_ORPHAN:
result = get_user(val, ip);
if (result)
return result;
sfp->keep_orphan = val;
return 0;
case SG_GET_KEEP_ORPHAN:
return put_user((int) sfp->keep_orphan, ip);
case SG_NEXT_CMD_LEN:
result = get_user(val, ip);
if (result)
return result;
sfp->next_cmd_len = (val > 0) ? val : 0;
return 0;
case SG_GET_VERSION_NUM:
return put_user(sg_version_num, ip);
case SG_GET_ACCESS_COUNT:
/* faked - we don't have a real access count anymore */
val = (sdp->device ? 1 : 0);
return put_user(val, ip);
case SG_GET_REQUEST_TABLE:
if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
return -EFAULT;
else {
sg_req_info_t *rinfo;
unsigned int ms;
rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
GFP_KERNEL);
if (!rinfo)
return -ENOMEM;
read_lock_irqsave(&sfp->rq_list_lock, iflags);
for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
++val, srp = srp ? srp->nextrp : srp) {