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sg.c
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sg.c
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 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 - 2014 Douglas Gilbert
*/
static int sg_version_num = 30536; /* 2 digits for each component */
#define SG_VERSION_STR "3.5.36"
/*
* D. P. Gilbert (dgilbert@interlog.com), 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/major.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/atomic.h>
#include <linux/ratelimit.h>
#include <linux/uio.h>
#include <linux/cred.h> /* for sg_check_file_access() */
#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/scsi_tcq.h>
#include <scsi/sg.h>
#include "scsi_logging.h"
#ifdef CONFIG_SCSI_PROC_FS
#include <linux/proc_fs.h>
static char *sg_version_date = "20140603";
static int sg_proc_init(void);
#endif
#define SG_ALLOW_DIO_DEF 0
#define SG_MAX_DEVS 32768
/* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
* of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater
* than 16 bytes are "variable length" whose length is a multiple of 4
*/
#define SG_MAX_CDB_SIZE 252
#define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
static 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_device(struct device *, struct class_interface *);
static void sg_remove_device(struct device *, struct class_interface *);
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_device,
.remove_dev = sg_remove_device,
};
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 list_head entry; /* list entry */
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 */
struct list_head sfd_siblings; /* protected by device's sfd_lock */
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 */
struct mutex f_mutex; /* protect against changes in this fd */
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 */
struct list_head rq_list; /* head of request list */
struct fasync_struct *async_qp; /* used by asynchronous notification */
Sg_request req_arr[SG_MAX_QUEUE]; /* used as singly-linked list */
char force_packid; /* 1 -> pack_id input to read(), 0 -> ignored */
char cmd_q; /* 1 -> allow command queuing, 0 -> don't */
unsigned char next_cmd_len; /* 0: automatic, >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 */
char res_in_use; /* 1 -> 'reserve' array in use */
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 open_wait; /* queue open() when O_EXCL present */
struct mutex open_rel_lock; /* held when in open() or release() */
int sg_tablesize; /* adapter's max scatter-gather table size */
u32 index; /* device index number */
struct list_head sfds;
rwlock_t sfd_lock; /* protect access to sfd list */
atomic_t detaching; /* 0->device usable, 1->device detaching */
bool exclude; /* 1->open(O_EXCL) succeeded and is active */
int open_cnt; /* count of opens (perhaps < num(sfds) ) */
char sgdebug; /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
char name[DISK_NAME_LEN];
struct cdev * cdev; /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
struct kref d_ref;
} Sg_device;
/* tasklet or soft irq callback */
static enum rq_end_io_ret sg_rq_end_io(struct request *rq, blk_status_t status);
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_fd * sfp, 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);
static void sg_remove_sfp(struct kref *);
static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id, bool *busy);
static Sg_request *sg_add_request(Sg_fd * sfp);
static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
static Sg_device *sg_get_dev(int dev);
static void sg_device_destroy(struct kref *kref);
#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)
#define sg_printk(prefix, sdp, fmt, a...) \
sdev_prefix_printk(prefix, (sdp)->device, (sdp)->name, fmt, ##a)
/*
* The SCSI interfaces that use read() and write() as an asynchronous variant of
* ioctl(..., SG_IO, ...) are fundamentally unsafe, since there are lots of ways
* to trigger read() and write() calls from various contexts with elevated
* privileges. This can lead to kernel memory corruption (e.g. if these
* interfaces are called through splice()) and privilege escalation inside
* userspace (e.g. if a process with access to such a device passes a file
* descriptor to a SUID binary as stdin/stdout/stderr).
*
* This function provides protection for the legacy API by restricting the
* calling context.
*/
static int sg_check_file_access(struct file *filp, const char *caller)
{
if (filp->f_cred != current_real_cred()) {
pr_err_once("%s: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
caller, task_tgid_vnr(current), current->comm);
return -EPERM;
}
return 0;
}
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;
if (!scsi_cmd_allowed(cmd, filp->f_mode))
return -EPERM;
return 0;
}
static int
open_wait(Sg_device *sdp, int flags)
{
int retval = 0;
if (flags & O_EXCL) {
while (sdp->open_cnt > 0) {
mutex_unlock(&sdp->open_rel_lock);
retval = wait_event_interruptible(sdp->open_wait,
(atomic_read(&sdp->detaching) ||
!sdp->open_cnt));
mutex_lock(&sdp->open_rel_lock);
if (retval) /* -ERESTARTSYS */
return retval;
if (atomic_read(&sdp->detaching))
return -ENODEV;
}
} else {
while (sdp->exclude) {
mutex_unlock(&sdp->open_rel_lock);
retval = wait_event_interruptible(sdp->open_wait,
(atomic_read(&sdp->detaching) ||
!sdp->exclude));
mutex_lock(&sdp->open_rel_lock);
if (retval) /* -ERESTARTSYS */
return retval;
if (atomic_read(&sdp->detaching))
return -ENODEV;
}
}
return retval;
}
/* Returns 0 on success, else a negated errno value */
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 retval;
nonseekable_open(inode, filp);
if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
return -EPERM; /* Can't lock it with read only access */
sdp = sg_get_dev(dev);
if (IS_ERR(sdp))
return PTR_ERR(sdp);
SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
"sg_open: flags=0x%x\n", flags));
/* 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;
/* scsi_block_when_processing_errors() may block so bypass
* check if O_NONBLOCK. Permits SCSI commands to be issued
* during error recovery. Tread carefully. */
if (!((flags & O_NONBLOCK) ||
scsi_block_when_processing_errors(sdp->device))) {
retval = -ENXIO;
/* we are in error recovery for this device */
goto error_out;
}
mutex_lock(&sdp->open_rel_lock);
if (flags & O_NONBLOCK) {
if (flags & O_EXCL) {
if (sdp->open_cnt > 0) {
retval = -EBUSY;
goto error_mutex_locked;
}
} else {
if (sdp->exclude) {
retval = -EBUSY;
goto error_mutex_locked;
}
}
} else {
retval = open_wait(sdp, flags);
if (retval) /* -ERESTARTSYS or -ENODEV */
goto error_mutex_locked;
}
/* N.B. at this point we are holding the open_rel_lock */
if (flags & O_EXCL)
sdp->exclude = true;
if (sdp->open_cnt < 1) { /* no existing opens */
sdp->sgdebug = 0;
q = sdp->device->request_queue;
sdp->sg_tablesize = queue_max_segments(q);
}
sfp = sg_add_sfp(sdp);
if (IS_ERR(sfp)) {
retval = PTR_ERR(sfp);
goto out_undo;
}
filp->private_data = sfp;
sdp->open_cnt++;
mutex_unlock(&sdp->open_rel_lock);
retval = 0;
sg_put:
kref_put(&sdp->d_ref, sg_device_destroy);
return retval;
out_undo:
if (flags & O_EXCL) {
sdp->exclude = false; /* undo if error */
wake_up_interruptible(&sdp->open_wait);
}
error_mutex_locked:
mutex_unlock(&sdp->open_rel_lock);
error_out:
scsi_autopm_put_device(sdp->device);
sdp_put:
scsi_device_put(sdp->device);
goto sg_put;
}
/* Release resources associated with a successful sg_open()
* Returns 0 on success, else a negated errno value */
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, sg_printk(KERN_INFO, sdp, "sg_release\n"));
mutex_lock(&sdp->open_rel_lock);
scsi_autopm_put_device(sdp->device);
kref_put(&sfp->f_ref, sg_remove_sfp);
sdp->open_cnt--;
/* possibly many open()s waiting on exlude clearing, start many;
* only open(O_EXCL)s wait on 0==open_cnt so only start one */
if (sdp->exclude) {
sdp->exclude = false;
wake_up_interruptible_all(&sdp->open_wait);
} else if (0 == sdp->open_cnt) {
wake_up_interruptible(&sdp->open_wait);
}
mutex_unlock(&sdp->open_rel_lock);
return 0;
}
static int get_sg_io_pack_id(int *pack_id, void __user *buf, size_t count)
{
struct sg_header __user *old_hdr = buf;
int reply_len;
if (count >= SZ_SG_HEADER) {
/* negative reply_len means v3 format, otherwise v1/v2 */
if (get_user(reply_len, &old_hdr->reply_len))
return -EFAULT;
if (reply_len >= 0)
return get_user(*pack_id, &old_hdr->pack_id);
if (in_compat_syscall() &&
count >= sizeof(struct compat_sg_io_hdr)) {
struct compat_sg_io_hdr __user *hp = buf;
return get_user(*pack_id, &hp->pack_id);
}
if (count >= sizeof(struct sg_io_hdr)) {
struct sg_io_hdr __user *hp = buf;
return get_user(*pack_id, &hp->pack_id);
}
}
/* no valid header was passed, so ignore the pack_id */
*pack_id = -1;
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;
bool busy;
sg_io_hdr_t *hp;
struct sg_header *old_hdr;
int retval;
/*
* This could cause a response to be stranded. Close the associated
* file descriptor to free up any resources being held.
*/
retval = sg_check_file_access(filp, __func__);
if (retval)
return retval;
if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
return -ENXIO;
SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
"sg_read: count=%d\n", (int) count));
if (sfp->force_packid)
retval = get_sg_io_pack_id(&req_pack_id, buf, count);
if (retval)
return retval;
srp = sg_get_rq_mark(sfp, req_pack_id, &busy);
if (!srp) { /* now wait on packet to arrive */
if (filp->f_flags & O_NONBLOCK)
return -EAGAIN;
retval = wait_event_interruptible(sfp->read_wait,
((srp = sg_get_rq_mark(sfp, req_pack_id, &busy)) ||
(!busy && atomic_read(&sdp->detaching))));
if (!srp)
/* signal or detaching */
return retval ? retval : -ENODEV;
}
if (srp->header.interface_id != '\0')
return sg_new_read(sfp, buf, count, srp);
hp = &srp->header;
old_hdr = kzalloc(SZ_SG_HEADER, GFP_KERNEL);
if (!old_hdr)
return -ENOMEM;
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) ||
(srp->sense_b[0] & 0x70) == 0x70) {
old_hdr->driver_status = DRIVER_SENSE;
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);
sg_remove_request(sfp, 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, err2;
int len;
if (in_compat_syscall()) {
if (count < sizeof(struct compat_sg_io_hdr)) {
err = -EINVAL;
goto err_out;
}
} else 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) ||
(srp->sense_b[0] & 0x70) == 0x70) {
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->driver_status = DRIVER_SENSE;
hp->sb_len_wr = len;
}
}
if (hp->masked_status || hp->host_status || hp->driver_status)
hp->info |= SG_INFO_CHECK;
err = put_sg_io_hdr(hp, buf);
err_out:
err2 = sg_finish_rem_req(srp);
sg_remove_request(sfp, srp);
return err ? : err2 ? : count;
}
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[SG_MAX_CDB_SIZE];
int retval;
retval = sg_check_file_access(filp, __func__);
if (retval)
return retval;
if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
return -ENXIO;
SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
"sg_write: count=%d\n", (int) count));
if (atomic_read(&sdp->detaching))
return -ENODEV;
if (!((filp->f_flags & O_NONBLOCK) ||
scsi_block_when_processing_errors(sdp->device)))
return -ENXIO;
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. */
buf += SZ_SG_HEADER;
if (get_user(opcode, buf))
return -EFAULT;
if (!(srp = sg_add_request(sfp))) {
SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
"sg_write: queue full\n"));
return -EDOM;
}
mutex_lock(&sfp->f_mutex);
if (sfp->next_cmd_len > 0) {
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;
}
mutex_unlock(&sfp->f_mutex);
SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
"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->dxfer_direction == SG_DXFER_TO_FROM_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)) {
sg_remove_request(sfp, srp);
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) {
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);
}
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[SG_MAX_CDB_SIZE];
int timeout;
unsigned long ul_timeout;
if (count < SZ_SG_IO_HDR)
return -EINVAL;
sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
if (!(srp = sg_add_request(sfp))) {
SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
"sg_new_write: queue full\n"));
return -EDOM;
}
srp->sg_io_owned = sg_io_owned;
hp = &srp->header;
if (get_sg_io_hdr(hp, buf)) {
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 (sfp->res_in_use) {
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 (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, at_head;
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, sg_printk(KERN_INFO, sfp->parentdp,
"sg_common_write: scsi opcode=0x%02x, cmd_size=%d\n",
(int) cmnd[0], (int) hp->cmd_len));
if (hp->dxfer_len >= SZ_256M) {
sg_remove_request(sfp, srp);
return -EINVAL;
}
k = sg_start_req(srp, cmnd);
if (k) {
SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
"sg_common_write: start_req err=%d\n", k));
sg_finish_rem_req(srp);
sg_remove_request(sfp, srp);
return k; /* probably out of space --> ENOMEM */
}
if (atomic_read(&sdp->detaching)) {
if (srp->bio) {
blk_mq_free_request(srp->rq);
srp->rq = NULL;
}
sg_finish_rem_req(srp);
sg_remove_request(sfp, srp);
return -ENODEV;
}
hp->duration = jiffies_to_msecs(jiffies);
if (hp->interface_id != '\0' && /* v3 (or later) interface */
(SG_FLAG_Q_AT_TAIL & hp->flags))
at_head = 0;
else
at_head = 1;
srp->rq->timeout = timeout;
kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
srp->rq->end_io = sg_rq_end_io;
blk_execute_rq_nowait(srp->rq, at_head);
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 int max_sectors_bytes(struct request_queue *q)
{
unsigned int max_sectors = queue_max_sectors(q);
max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
return max_sectors << 9;
}
static void
sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
{
Sg_request *srp;
int val;
unsigned int ms;
val = 0;
list_for_each_entry(srp, &sfp->rq_list, entry) {
if (val >= SG_MAX_QUEUE)
break;
rinfo[val].req_state = srp->done + 1;
rinfo[val].problem =
srp->header.masked_status &
srp->header.host_status &
srp->header.driver_status;
if (srp->done)
rinfo[val].duration =
srp->header.duration;
else {
ms = jiffies_to_msecs(jiffies);
rinfo[val].duration =
(ms > srp->header.duration) ?
(ms - srp->header.duration) : 0;
}
rinfo[val].orphan = srp->orphan;
rinfo[val].sg_io_owned = srp->sg_io_owned;
rinfo[val].pack_id = srp->header.pack_id;
rinfo[val].usr_ptr = srp->header.usr_ptr;
val++;
}
}
#ifdef CONFIG_COMPAT
struct compat_sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
char req_state;
char orphan;
char sg_io_owned;
char problem;
int pack_id;
compat_uptr_t usr_ptr;
unsigned int duration;
int unused;
};
static int put_compat_request_table(struct compat_sg_req_info __user *o,
struct sg_req_info *rinfo)
{
int i;
for (i = 0; i < SG_MAX_QUEUE; i++) {
if (copy_to_user(o + i, rinfo + i, offsetof(sg_req_info_t, usr_ptr)) ||
put_user((uintptr_t)rinfo[i].usr_ptr, &o[i].usr_ptr) ||
put_user(rinfo[i].duration, &o[i].duration) ||
put_user(rinfo[i].unused, &o[i].unused))
return -EFAULT;
}
return 0;
}
#endif
static long
sg_ioctl_common(struct file *filp, Sg_device *sdp, Sg_fd *sfp,
unsigned int cmd_in, void __user *p)
{
int __user *ip = p;
int result, val, read_only;
Sg_request *srp;
unsigned long iflags;
SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
"sg_ioctl: cmd=0x%x\n", (int) cmd_in));
read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
switch (cmd_in) {
case SG_IO:
if (atomic_read(&sdp->detaching))
return -ENODEV;
if (!scsi_block_when_processing_errors(sdp->device))
return -ENXIO;
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));
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 >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
INT_MAX);
sfp->timeout_user = val;
sfp->timeout = mult_frac(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:
/*
* N.B. This ioctl never worked properly, but failed to
* return an error value. So returning '0' to keep compability
* with legacy applications.
*/
return 0;
case SG_GET_LOW_DMA:
return put_user(0, ip);
case SG_GET_SCSI_ID:
{
sg_scsi_id_t v;
if (atomic_read(&sdp->detaching))
return -ENODEV;
memset(&v, 0, sizeof(v));
v.host_no = sdp->device->host->host_no;
v.channel = sdp->device->channel;
v.scsi_id = sdp->device->id;
v.lun = sdp->device->lun;
v.scsi_type = sdp->device->type;
v.h_cmd_per_lun = sdp->device->host->cmd_per_lun;
v.d_queue_depth = sdp->device->queue_depth;
if (copy_to_user(p, &v, sizeof(sg_scsi_id_t)))
return -EFAULT;
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: