1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  History:
   4 *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
   5 *           to allow user process control of SCSI devices.
   6 *  Development Sponsored by Killy Corp. NY NY
   7 *
   8 * Original driver (sg.c):
   9 *        Copyright (C) 1992 Lawrence Foard
  10 * Version 2 and 3 extensions to driver:
  11 *        Copyright (C) 1998 - 2014 Douglas Gilbert
  12 */
  13
  14static int sg_version_num = 30536;	/* 2 digits for each component */
  15#define SG_VERSION_STR "3.5.36"
  16
  17/*
  18 *  D. P. Gilbert (dgilbert@interlog.com), notes:
  19 *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
  20 *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
  21 *        (otherwise the macros compile to empty statements).
  22 *
  23 */
  24#include <linux/module.h>
  25
  26#include <linux/fs.h>
  27#include <linux/kernel.h>
  28#include <linux/sched.h>
  29#include <linux/string.h>
  30#include <linux/mm.h>
  31#include <linux/errno.h>
  32#include <linux/mtio.h>
  33#include <linux/ioctl.h>
  34#include <linux/major.h>
  35#include <linux/slab.h>
  36#include <linux/fcntl.h>
  37#include <linux/init.h>
  38#include <linux/poll.h>
  39#include <linux/moduleparam.h>
  40#include <linux/cdev.h>
  41#include <linux/idr.h>
  42#include <linux/seq_file.h>
  43#include <linux/blkdev.h>
  44#include <linux/delay.h>
  45#include <linux/blktrace_api.h>
  46#include <linux/mutex.h>
  47#include <linux/atomic.h>
  48#include <linux/ratelimit.h>
  49#include <linux/uio.h>
  50#include <linux/cred.h> /* for sg_check_file_access() */
  51
  52#include <scsi/scsi.h>
  53#include <scsi/scsi_cmnd.h>
  54#include <scsi/scsi_dbg.h>
  55#include <scsi/scsi_device.h>
  56#include <scsi/scsi_driver.h>
  57#include <scsi/scsi_eh.h>
  58#include <scsi/scsi_host.h>
  59#include <scsi/scsi_ioctl.h>
  60#include <scsi/scsi_tcq.h>
  61#include <scsi/sg.h>
  62
  63#include "scsi_logging.h"
  64
  65#ifdef CONFIG_SCSI_PROC_FS
  66#include <linux/proc_fs.h>
  67static char *sg_version_date = "20140603";
  68
  69static int sg_proc_init(void);
  70#endif
  71
  72#define SG_ALLOW_DIO_DEF 0
  73
  74#define SG_MAX_DEVS (1 << MINORBITS)
  75
  76/* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
  77 * of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater
  78 * than 16 bytes are "variable length" whose length is a multiple of 4
  79 */
  80#define SG_MAX_CDB_SIZE 252
  81
  82#define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  83
  84static int sg_big_buff = SG_DEF_RESERVED_SIZE;
  85/* N.B. This variable is readable and writeable via
  86   /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  87   of this size (or less if there is not enough memory) will be reserved
  88   for use by this file descriptor. [Deprecated usage: this variable is also
  89   readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  90   the kernel (i.e. it is not a module).] */
  91static int def_reserved_size = -1;	/* picks up init parameter */
  92static int sg_allow_dio = SG_ALLOW_DIO_DEF;
  93
  94static int scatter_elem_sz = SG_SCATTER_SZ;
  95static int scatter_elem_sz_prev = SG_SCATTER_SZ;
  96
  97#define SG_SECTOR_SZ 512
  98
  99static int sg_add_device(struct device *);
 100static void sg_remove_device(struct device *);
 101
 102static DEFINE_IDR(sg_index_idr);
 103static DEFINE_RWLOCK(sg_index_lock);	/* Also used to lock
 104							   file descriptor list for device */
 105
 106static struct class_interface sg_interface = {
 107	.add_dev        = sg_add_device,
 108	.remove_dev     = sg_remove_device,
 109};
 110
 111typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 112	unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 113	unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 114	unsigned bufflen;	/* Size of (aggregate) data buffer */
 115	struct page **pages;
 116	int page_order;
 117	char dio_in_use;	/* 0->indirect IO (or mmap), 1->dio */
 118	unsigned char cmd_opcode; /* first byte of command */
 119} Sg_scatter_hold;
 120
 121struct sg_device;		/* forward declarations */
 122struct sg_fd;
 123
 124typedef struct sg_request {	/* SG_MAX_QUEUE requests outstanding per file */
 125	struct list_head entry;	/* list entry */
 126	struct sg_fd *parentfp;	/* NULL -> not in use */
 127	Sg_scatter_hold data;	/* hold buffer, perhaps scatter list */
 128	sg_io_hdr_t header;	/* scsi command+info, see <scsi/sg.h> */
 129	unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 130	char res_used;		/* 1 -> using reserve buffer, 0 -> not ... */
 131	char orphan;		/* 1 -> drop on sight, 0 -> normal */
 132	char sg_io_owned;	/* 1 -> packet belongs to SG_IO */
 133	/* done protected by rq_list_lock */
 134	char done;		/* 0->before bh, 1->before read, 2->read */
 135	struct request *rq;
 136	struct bio *bio;
 137	struct execute_work ew;
 138} Sg_request;
 139
 140typedef struct sg_fd {		/* holds the state of a file descriptor */
 141	struct list_head sfd_siblings;  /* protected by device's sfd_lock */
 142	struct sg_device *parentdp;	/* owning device */
 143	wait_queue_head_t read_wait;	/* queue read until command done */
 144	rwlock_t rq_list_lock;	/* protect access to list in req_arr */
 145	struct mutex f_mutex;	/* protect against changes in this fd */
 146	int timeout;		/* defaults to SG_DEFAULT_TIMEOUT      */
 147	int timeout_user;	/* defaults to SG_DEFAULT_TIMEOUT_USER */
 148	Sg_scatter_hold reserve;	/* buffer held for this file descriptor */
 149	struct list_head rq_list; /* head of request list */
 150	struct fasync_struct *async_qp;	/* used by asynchronous notification */
 151	Sg_request req_arr[SG_MAX_QUEUE];	/* used as singly-linked list */
 152	char force_packid;	/* 1 -> pack_id input to read(), 0 -> ignored */
 153	char cmd_q;		/* 1 -> allow command queuing, 0 -> don't */
 154	unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */
 155	char keep_orphan;	/* 0 -> drop orphan (def), 1 -> keep for read() */
 156	char mmap_called;	/* 0 -> mmap() never called on this fd */
 157	char res_in_use;	/* 1 -> 'reserve' array in use */
 158	struct kref f_ref;
 159	struct execute_work ew;
 160} Sg_fd;
 161
 162typedef struct sg_device { /* holds the state of each scsi generic device */
 163	struct scsi_device *device;
 164	wait_queue_head_t open_wait;    /* queue open() when O_EXCL present */
 165	struct mutex open_rel_lock;     /* held when in open() or release() */
 166	int sg_tablesize;	/* adapter's max scatter-gather table size */
 167	u32 index;		/* device index number */
 168	struct list_head sfds;
 169	rwlock_t sfd_lock;      /* protect access to sfd list */
 170	atomic_t detaching;     /* 0->device usable, 1->device detaching */
 171	bool exclude;		/* 1->open(O_EXCL) succeeded and is active */
 172	int open_cnt;		/* count of opens (perhaps < num(sfds) ) */
 173	char sgdebug;		/* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 174	char name[DISK_NAME_LEN];
 175	struct cdev * cdev;	/* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 176	struct kref d_ref;
 177} Sg_device;
 178
 179/* tasklet or soft irq callback */
 180static enum rq_end_io_ret sg_rq_end_io(struct request *rq, blk_status_t status);
 181static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 182static int sg_finish_rem_req(Sg_request * srp);
 183static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 184static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 185			   Sg_request * srp);
 186static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
 187			const char __user *buf, size_t count, int blocking,
 188			int read_only, int sg_io_owned, Sg_request **o_srp);
 189static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 190			   unsigned char *cmnd, int timeout, int blocking);
 191static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 192static void sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp);
 193static void sg_build_reserve(Sg_fd * sfp, int req_size);
 194static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 195static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 196static Sg_fd *sg_add_sfp(Sg_device * sdp);
 197static void sg_remove_sfp(struct kref *);
 198static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id, bool *busy);
 199static Sg_request *sg_add_request(Sg_fd * sfp);
 200static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 201static Sg_device *sg_get_dev(int dev);
 202static void sg_device_destroy(struct kref *kref);
 203
 204#define SZ_SG_HEADER sizeof(struct sg_header)
 205#define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 206#define SZ_SG_IOVEC sizeof(sg_iovec_t)
 207#define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 208
 209#define sg_printk(prefix, sdp, fmt, a...) \
 210	sdev_prefix_printk(prefix, (sdp)->device, (sdp)->name, fmt, ##a)
 211
 212/*
 213 * The SCSI interfaces that use read() and write() as an asynchronous variant of
 214 * ioctl(..., SG_IO, ...) are fundamentally unsafe, since there are lots of ways
 215 * to trigger read() and write() calls from various contexts with elevated
 216 * privileges. This can lead to kernel memory corruption (e.g. if these
 217 * interfaces are called through splice()) and privilege escalation inside
 218 * userspace (e.g. if a process with access to such a device passes a file
 219 * descriptor to a SUID binary as stdin/stdout/stderr).
 220 *
 221 * This function provides protection for the legacy API by restricting the
 222 * calling context.
 223 */
 224static int sg_check_file_access(struct file *filp, const char *caller)
 225{
 226	if (filp->f_cred != current_real_cred()) {
 227		pr_err_once("%s: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
 228			caller, task_tgid_vnr(current), current->comm);
 229		return -EPERM;
 230	}
 231	return 0;
 232}
 233
 234static int sg_allow_access(struct file *filp, unsigned char *cmd)
 235{
 236	struct sg_fd *sfp = filp->private_data;
 237
 238	if (sfp->parentdp->device->type == TYPE_SCANNER)
 239		return 0;
 240	if (!scsi_cmd_allowed(cmd, filp->f_mode & FMODE_WRITE))
 241		return -EPERM;
 242	return 0;
 243}
 244
 245static int
 246open_wait(Sg_device *sdp, int flags)
 247{
 248	int retval = 0;
 249
 250	if (flags & O_EXCL) {
 251		while (sdp->open_cnt > 0) {
 252			mutex_unlock(&sdp->open_rel_lock);
 253			retval = wait_event_interruptible(sdp->open_wait,
 254					(atomic_read(&sdp->detaching) ||
 255					 !sdp->open_cnt));
 256			mutex_lock(&sdp->open_rel_lock);
 257
 258			if (retval) /* -ERESTARTSYS */
 259				return retval;
 260			if (atomic_read(&sdp->detaching))
 261				return -ENODEV;
 262		}
 263	} else {
 264		while (sdp->exclude) {
 265			mutex_unlock(&sdp->open_rel_lock);
 266			retval = wait_event_interruptible(sdp->open_wait,
 267					(atomic_read(&sdp->detaching) ||
 268					 !sdp->exclude));
 269			mutex_lock(&sdp->open_rel_lock);
 270
 271			if (retval) /* -ERESTARTSYS */
 272				return retval;
 273			if (atomic_read(&sdp->detaching))
 274				return -ENODEV;
 275		}
 276	}
 277
 278	return retval;
 279}
 280
 281/* Returns 0 on success, else a negated errno value */
 282static int
 283sg_open(struct inode *inode, struct file *filp)
 284{
 285	int dev = iminor(inode);
 286	int flags = filp->f_flags;
 287	struct request_queue *q;
 288	Sg_device *sdp;
 289	Sg_fd *sfp;
 290	int retval;
 291
 292	nonseekable_open(inode, filp);
 293	if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
 294		return -EPERM; /* Can't lock it with read only access */
 295	sdp = sg_get_dev(dev);
 296	if (IS_ERR(sdp))
 297		return PTR_ERR(sdp);
 298
 299	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 300				      "sg_open: flags=0x%x\n", flags));
 301
 302	/* This driver's module count bumped by fops_get in <linux/fs.h> */
 303	/* Prevent the device driver from vanishing while we sleep */
 304	retval = scsi_device_get(sdp->device);
 305	if (retval)
 306		goto sg_put;
 307
 308	retval = scsi_autopm_get_device(sdp->device);
 309	if (retval)
 310		goto sdp_put;
 311
 312	/* scsi_block_when_processing_errors() may block so bypass
 313	 * check if O_NONBLOCK. Permits SCSI commands to be issued
 314	 * during error recovery. Tread carefully. */
 315	if (!((flags & O_NONBLOCK) ||
 316	      scsi_block_when_processing_errors(sdp->device))) {
 317		retval = -ENXIO;
 318		/* we are in error recovery for this device */
 319		goto error_out;
 320	}
 321
 322	mutex_lock(&sdp->open_rel_lock);
 323	if (flags & O_NONBLOCK) {
 324		if (flags & O_EXCL) {
 325			if (sdp->open_cnt > 0) {
 326				retval = -EBUSY;
 327				goto error_mutex_locked;
 328			}
 329		} else {
 330			if (sdp->exclude) {
 331				retval = -EBUSY;
 332				goto error_mutex_locked;
 333			}
 334		}
 335	} else {
 336		retval = open_wait(sdp, flags);
 337		if (retval) /* -ERESTARTSYS or -ENODEV */
 338			goto error_mutex_locked;
 339	}
 340
 341	/* N.B. at this point we are holding the open_rel_lock */
 342	if (flags & O_EXCL)
 343		sdp->exclude = true;
 344
 345	if (sdp->open_cnt < 1) {  /* no existing opens */
 346		sdp->sgdebug = 0;
 347		q = sdp->device->request_queue;
 348		sdp->sg_tablesize = queue_max_segments(q);
 349	}
 350	sfp = sg_add_sfp(sdp);
 351	if (IS_ERR(sfp)) {
 352		retval = PTR_ERR(sfp);
 353		goto out_undo;
 354	}
 355
 356	filp->private_data = sfp;
 357	sdp->open_cnt++;
 358	mutex_unlock(&sdp->open_rel_lock);
 359
 360	retval = 0;
 361sg_put:
 362	kref_put(&sdp->d_ref, sg_device_destroy);
 363	return retval;
 364
 365out_undo:
 366	if (flags & O_EXCL) {
 367		sdp->exclude = false;   /* undo if error */
 368		wake_up_interruptible(&sdp->open_wait);
 369	}
 370error_mutex_locked:
 371	mutex_unlock(&sdp->open_rel_lock);
 372error_out:
 373	scsi_autopm_put_device(sdp->device);
 374sdp_put:
 375	scsi_device_put(sdp->device);
 376	goto sg_put;
 377}
 378
 379/* Release resources associated with a successful sg_open()
 380 * Returns 0 on success, else a negated errno value */
 381static int
 382sg_release(struct inode *inode, struct file *filp)
 383{
 384	Sg_device *sdp;
 385	Sg_fd *sfp;
 386
 387	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 388		return -ENXIO;
 389	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
 390
 391	mutex_lock(&sdp->open_rel_lock);
 392	scsi_autopm_put_device(sdp->device);
 393	kref_put(&sfp->f_ref, sg_remove_sfp);
 394	sdp->open_cnt--;
 395
 396	/* possibly many open()s waiting on exlude clearing, start many;
 397	 * only open(O_EXCL)s wait on 0==open_cnt so only start one */
 398	if (sdp->exclude) {
 399		sdp->exclude = false;
 400		wake_up_interruptible_all(&sdp->open_wait);
 401	} else if (0 == sdp->open_cnt) {
 402		wake_up_interruptible(&sdp->open_wait);
 403	}
 404	mutex_unlock(&sdp->open_rel_lock);
 405	return 0;
 406}
 407
 408static int get_sg_io_pack_id(int *pack_id, void __user *buf, size_t count)
 409{
 410	struct sg_header __user *old_hdr = buf;
 411	int reply_len;
 412
 413	if (count >= SZ_SG_HEADER) {
 414		/* negative reply_len means v3 format, otherwise v1/v2 */
 415		if (get_user(reply_len, &old_hdr->reply_len))
 416			return -EFAULT;
 417
 418		if (reply_len >= 0)
 419			return get_user(*pack_id, &old_hdr->pack_id);
 420
 421		if (in_compat_syscall() &&
 422		    count >= sizeof(struct compat_sg_io_hdr)) {
 423			struct compat_sg_io_hdr __user *hp = buf;
 424
 425			return get_user(*pack_id, &hp->pack_id);
 426		}
 427
 428		if (count >= sizeof(struct sg_io_hdr)) {
 429			struct sg_io_hdr __user *hp = buf;
 430
 431			return get_user(*pack_id, &hp->pack_id);
 432		}
 433	}
 434
 435	/* no valid header was passed, so ignore the pack_id */
 436	*pack_id = -1;
 437	return 0;
 438}
 439
 440static ssize_t
 441sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 442{
 443	Sg_device *sdp;
 444	Sg_fd *sfp;
 445	Sg_request *srp;
 446	int req_pack_id = -1;
 447	bool busy;
 448	sg_io_hdr_t *hp;
 449	struct sg_header *old_hdr;
 450	int retval;
 451
 452	/*
 453	 * This could cause a response to be stranded. Close the associated
 454	 * file descriptor to free up any resources being held.
 455	 */
 456	retval = sg_check_file_access(filp, __func__);
 457	if (retval)
 458		return retval;
 459
 460	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 461		return -ENXIO;
 462	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 463				      "sg_read: count=%d\n", (int) count));
 464
 465	if (sfp->force_packid)
 466		retval = get_sg_io_pack_id(&req_pack_id, buf, count);
 467	if (retval)
 468		return retval;
 469
 470	srp = sg_get_rq_mark(sfp, req_pack_id, &busy);
 471	if (!srp) {		/* now wait on packet to arrive */
 472		if (filp->f_flags & O_NONBLOCK)
 473			return -EAGAIN;
 474		retval = wait_event_interruptible(sfp->read_wait,
 475			((srp = sg_get_rq_mark(sfp, req_pack_id, &busy)) ||
 476			(!busy && atomic_read(&sdp->detaching))));
 477		if (!srp)
 478			/* signal or detaching */
 479			return retval ? retval : -ENODEV;
 480	}
 481	if (srp->header.interface_id != '\0')
 482		return sg_new_read(sfp, buf, count, srp);
 483
 484	hp = &srp->header;
 485	old_hdr = kzalloc(SZ_SG_HEADER, GFP_KERNEL);
 486	if (!old_hdr)
 487		return -ENOMEM;
 488
 489	old_hdr->reply_len = (int) hp->timeout;
 490	old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 491	old_hdr->pack_id = hp->pack_id;
 492	old_hdr->twelve_byte =
 493	    ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 494	old_hdr->target_status = hp->masked_status;
 495	old_hdr->host_status = hp->host_status;
 496	old_hdr->driver_status = hp->driver_status;
 497	if ((CHECK_CONDITION & hp->masked_status) ||
 498	    (srp->sense_b[0] & 0x70) == 0x70) {
 499		old_hdr->driver_status = DRIVER_SENSE;
 500		memcpy(old_hdr->sense_buffer, srp->sense_b,
 501		       sizeof (old_hdr->sense_buffer));
 502	}
 503	switch (hp->host_status) {
 504	/* This setup of 'result' is for backward compatibility and is best
 505	   ignored by the user who should use target, host + driver status */
 506	case DID_OK:
 507	case DID_PASSTHROUGH:
 508	case DID_SOFT_ERROR:
 509		old_hdr->result = 0;
 510		break;
 511	case DID_NO_CONNECT:
 512	case DID_BUS_BUSY:
 513	case DID_TIME_OUT:
 514		old_hdr->result = EBUSY;
 515		break;
 516	case DID_BAD_TARGET:
 517	case DID_ABORT:
 518	case DID_PARITY:
 519	case DID_RESET:
 520	case DID_BAD_INTR:
 521		old_hdr->result = EIO;
 522		break;
 523	case DID_ERROR:
 524		old_hdr->result = (srp->sense_b[0] == 0 && 
 525				  hp->masked_status == GOOD) ? 0 : EIO;
 526		break;
 527	default:
 528		old_hdr->result = EIO;
 529		break;
 530	}
 531
 532	/* Now copy the result back to the user buffer.  */
 533	if (count >= SZ_SG_HEADER) {
 534		if (copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 535			retval = -EFAULT;
 536			goto free_old_hdr;
 537		}
 538		buf += SZ_SG_HEADER;
 539		if (count > old_hdr->reply_len)
 540			count = old_hdr->reply_len;
 541		if (count > SZ_SG_HEADER) {
 542			if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 543				retval = -EFAULT;
 544				goto free_old_hdr;
 545			}
 546		}
 547	} else
 548		count = (old_hdr->result == 0) ? 0 : -EIO;
 549	sg_finish_rem_req(srp);
 550	sg_remove_request(sfp, srp);
 551	retval = count;
 552free_old_hdr:
 553	kfree(old_hdr);
 554	return retval;
 555}
 556
 557static ssize_t
 558sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 559{
 560	sg_io_hdr_t *hp = &srp->header;
 561	int err = 0, err2;
 562	int len;
 563
 564	if (in_compat_syscall()) {
 565		if (count < sizeof(struct compat_sg_io_hdr)) {
 566			err = -EINVAL;
 567			goto err_out;
 568		}
 569	} else if (count < SZ_SG_IO_HDR) {
 570		err = -EINVAL;
 571		goto err_out;
 572	}
 573	hp->sb_len_wr = 0;
 574	if ((hp->mx_sb_len > 0) && hp->sbp) {
 575		if ((CHECK_CONDITION & hp->masked_status) ||
 576		    (srp->sense_b[0] & 0x70) == 0x70) {
 577			int sb_len = SCSI_SENSE_BUFFERSIZE;
 578			sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 579			len = 8 + (int) srp->sense_b[7];	/* Additional sense length field */
 580			len = (len > sb_len) ? sb_len : len;
 581			if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 582				err = -EFAULT;
 583				goto err_out;
 584			}
 585			hp->driver_status = DRIVER_SENSE;
 586			hp->sb_len_wr = len;
 587		}
 588	}
 589	if (hp->masked_status || hp->host_status || hp->driver_status)
 590		hp->info |= SG_INFO_CHECK;
 591	err = put_sg_io_hdr(hp, buf);
 592err_out:
 593	err2 = sg_finish_rem_req(srp);
 594	sg_remove_request(sfp, srp);
 595	return err ? : err2 ? : count;
 596}
 597
 598static ssize_t
 599sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 600{
 601	int mxsize, cmd_size, k;
 602	int input_size, blocking;
 603	unsigned char opcode;
 604	Sg_device *sdp;
 605	Sg_fd *sfp;
 606	Sg_request *srp;
 607	struct sg_header old_hdr;
 608	sg_io_hdr_t *hp;
 609	unsigned char cmnd[SG_MAX_CDB_SIZE];
 610	int retval;
 611
 612	retval = sg_check_file_access(filp, __func__);
 613	if (retval)
 614		return retval;
 615
 616	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 617		return -ENXIO;
 618	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 619				      "sg_write: count=%d\n", (int) count));
 620	if (atomic_read(&sdp->detaching))
 621		return -ENODEV;
 622	if (!((filp->f_flags & O_NONBLOCK) ||
 623	      scsi_block_when_processing_errors(sdp->device)))
 624		return -ENXIO;
 625
 626	if (count < SZ_SG_HEADER)
 627		return -EIO;
 628	if (copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 629		return -EFAULT;
 630	blocking = !(filp->f_flags & O_NONBLOCK);
 631	if (old_hdr.reply_len < 0)
 632		return sg_new_write(sfp, filp, buf, count,
 633				    blocking, 0, 0, NULL);
 634	if (count < (SZ_SG_HEADER + 6))
 635		return -EIO;	/* The minimum scsi command length is 6 bytes. */
 636
 637	buf += SZ_SG_HEADER;
 638	if (get_user(opcode, buf))
 639		return -EFAULT;
 640
 641	if (!(srp = sg_add_request(sfp))) {
 642		SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
 643					      "sg_write: queue full\n"));
 644		return -EDOM;
 645	}
 646	mutex_lock(&sfp->f_mutex);
 647	if (sfp->next_cmd_len > 0) {
 648		cmd_size = sfp->next_cmd_len;
 649		sfp->next_cmd_len = 0;	/* reset so only this write() effected */
 650	} else {
 651		cmd_size = COMMAND_SIZE(opcode);	/* based on SCSI command group */
 652		if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 653			cmd_size = 12;
 654	}
 655	mutex_unlock(&sfp->f_mutex);
 656	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
 657		"sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 658/* Determine buffer size.  */
 659	input_size = count - cmd_size;
 660	mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 661	mxsize -= SZ_SG_HEADER;
 662	input_size -= SZ_SG_HEADER;
 663	if (input_size < 0) {
 664		sg_remove_request(sfp, srp);
 665		return -EIO;	/* User did not pass enough bytes for this command. */
 666	}
 667	hp = &srp->header;
 668	hp->interface_id = '\0';	/* indicator of old interface tunnelled */
 669	hp->cmd_len = (unsigned char) cmd_size;
 670	hp->iovec_count = 0;
 671	hp->mx_sb_len = 0;
 672	if (input_size > 0)
 673		hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 674		    SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 675	else
 676		hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 677	hp->dxfer_len = mxsize;
 678	if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
 679	    (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
 680		hp->dxferp = (char __user *)buf + cmd_size;
 681	else
 682		hp->dxferp = NULL;
 683	hp->sbp = NULL;
 684	hp->timeout = old_hdr.reply_len;	/* structure abuse ... */
 685	hp->flags = input_size;	/* structure abuse ... */
 686	hp->pack_id = old_hdr.pack_id;
 687	hp->usr_ptr = NULL;
 688	if (copy_from_user(cmnd, buf, cmd_size)) {
 689		sg_remove_request(sfp, srp);
 690		return -EFAULT;
 691	}
 692	/*
 693	 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 694	 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 695	 * is a non-zero input_size, so emit a warning.
 696	 */
 697	if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 698		printk_ratelimited(KERN_WARNING
 699				   "sg_write: data in/out %d/%d bytes "
 700				   "for SCSI command 0x%x-- guessing "
 701				   "data in;\n   program %s not setting "
 702				   "count and/or reply_len properly\n",
 703				   old_hdr.reply_len - (int)SZ_SG_HEADER,
 704				   input_size, (unsigned int) cmnd[0],
 705				   current->comm);
 706	}
 707	k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 708	return (k < 0) ? k : count;
 709}
 710
 711static ssize_t
 712sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 713		 size_t count, int blocking, int read_only, int sg_io_owned,
 714		 Sg_request **o_srp)
 715{
 716	int k;
 717	Sg_request *srp;
 718	sg_io_hdr_t *hp;
 719	unsigned char cmnd[SG_MAX_CDB_SIZE];
 720	int timeout;
 721	unsigned long ul_timeout;
 722
 723	if (count < SZ_SG_IO_HDR)
 724		return -EINVAL;
 725
 726	sfp->cmd_q = 1;	/* when sg_io_hdr seen, set command queuing on */
 727	if (!(srp = sg_add_request(sfp))) {
 728		SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 729					      "sg_new_write: queue full\n"));
 730		return -EDOM;
 731	}
 732	srp->sg_io_owned = sg_io_owned;
 733	hp = &srp->header;
 734	if (get_sg_io_hdr(hp, buf)) {
 735		sg_remove_request(sfp, srp);
 736		return -EFAULT;
 737	}
 738	if (hp->interface_id != 'S') {
 739		sg_remove_request(sfp, srp);
 740		return -ENOSYS;
 741	}
 742	if (hp->flags & SG_FLAG_MMAP_IO) {
 743		if (hp->dxfer_len > sfp->reserve.bufflen) {
 744			sg_remove_request(sfp, srp);
 745			return -ENOMEM;	/* MMAP_IO size must fit in reserve buffer */
 746		}
 747		if (hp->flags & SG_FLAG_DIRECT_IO) {
 748			sg_remove_request(sfp, srp);
 749			return -EINVAL;	/* either MMAP_IO or DIRECT_IO (not both) */
 750		}
 751		if (sfp->res_in_use) {
 752			sg_remove_request(sfp, srp);
 753			return -EBUSY;	/* reserve buffer already being used */
 754		}
 755	}
 756	ul_timeout = msecs_to_jiffies(srp->header.timeout);
 757	timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 758	if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 759		sg_remove_request(sfp, srp);
 760		return -EMSGSIZE;
 761	}
 762	if (copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 763		sg_remove_request(sfp, srp);
 764		return -EFAULT;
 765	}
 766	if (read_only && sg_allow_access(file, cmnd)) {
 767		sg_remove_request(sfp, srp);
 768		return -EPERM;
 769	}
 770	k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 771	if (k < 0)
 772		return k;
 773	if (o_srp)
 774		*o_srp = srp;
 775	return count;
 776}
 777
 778static int
 779sg_common_write(Sg_fd * sfp, Sg_request * srp,
 780		unsigned char *cmnd, int timeout, int blocking)
 781{
 782	int k, at_head;
 783	Sg_device *sdp = sfp->parentdp;
 784	sg_io_hdr_t *hp = &srp->header;
 785
 786	srp->data.cmd_opcode = cmnd[0];	/* hold opcode of command */
 787	hp->status = 0;
 788	hp->masked_status = 0;
 789	hp->msg_status = 0;
 790	hp->info = 0;
 791	hp->host_status = 0;
 792	hp->driver_status = 0;
 793	hp->resid = 0;
 794	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
 795			"sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 796			(int) cmnd[0], (int) hp->cmd_len));
 797
 798	if (hp->dxfer_len >= SZ_256M) {
 799		sg_remove_request(sfp, srp);
 800		return -EINVAL;
 801	}
 802
 803	k = sg_start_req(srp, cmnd);
 804	if (k) {
 805		SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 806			"sg_common_write: start_req err=%d\n", k));
 807		sg_finish_rem_req(srp);
 808		sg_remove_request(sfp, srp);
 809		return k;	/* probably out of space --> ENOMEM */
 810	}
 811	if (atomic_read(&sdp->detaching)) {
 812		if (srp->bio) {
 813			blk_mq_free_request(srp->rq);
 814			srp->rq = NULL;
 815		}
 816
 817		sg_finish_rem_req(srp);
 818		sg_remove_request(sfp, srp);
 819		return -ENODEV;
 820	}
 821
 822	hp->duration = jiffies_to_msecs(jiffies);
 823	if (hp->interface_id != '\0' &&	/* v3 (or later) interface */
 824	    (SG_FLAG_Q_AT_TAIL & hp->flags))
 825		at_head = 0;
 826	else
 827		at_head = 1;
 828
 829	srp->rq->timeout = timeout;
 830	kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
 831	srp->rq->end_io = sg_rq_end_io;
 832	blk_execute_rq_nowait(srp->rq, at_head);
 833	return 0;
 834}
 835
 836static int srp_done(Sg_fd *sfp, Sg_request *srp)
 837{
 838	unsigned long flags;
 839	int ret;
 840
 841	read_lock_irqsave(&sfp->rq_list_lock, flags);
 842	ret = srp->done;
 843	read_unlock_irqrestore(&sfp->rq_list_lock, flags);
 844	return ret;
 845}
 846
 847static int max_sectors_bytes(struct request_queue *q)
 848{
 849	unsigned int max_sectors = queue_max_sectors(q);
 850
 851	max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
 852
 853	return max_sectors << 9;
 854}
 855
 856static void
 857sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
 858{
 859	Sg_request *srp;
 860	int val;
 861	unsigned int ms;
 862
 863	val = 0;
 864	list_for_each_entry(srp, &sfp->rq_list, entry) {
 865		if (val >= SG_MAX_QUEUE)
 866			break;
 867		rinfo[val].req_state = srp->done + 1;
 868		rinfo[val].problem =
 869			srp->header.masked_status &
 870			srp->header.host_status &
 871			srp->header.driver_status;
 872		if (srp->done)
 873			rinfo[val].duration =
 874				srp->header.duration;
 875		else {
 876			ms = jiffies_to_msecs(jiffies);
 877			rinfo[val].duration =
 878				(ms > srp->header.duration) ?
 879				(ms - srp->header.duration) : 0;
 880		}
 881		rinfo[val].orphan = srp->orphan;
 882		rinfo[val].sg_io_owned = srp->sg_io_owned;
 883		rinfo[val].pack_id = srp->header.pack_id;
 884		rinfo[val].usr_ptr = srp->header.usr_ptr;
 885		val++;
 886	}
 887}
 888
 889#ifdef CONFIG_COMPAT
 890struct compat_sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
 891	char req_state;
 892	char orphan;
 893	char sg_io_owned;
 894	char problem;
 895	int pack_id;
 896	compat_uptr_t usr_ptr;
 897	unsigned int duration;
 898	int unused;
 899};
 900
 901static int put_compat_request_table(struct compat_sg_req_info __user *o,
 902				    struct sg_req_info *rinfo)
 903{
 904	int i;
 905	for (i = 0; i < SG_MAX_QUEUE; i++) {
 906		if (copy_to_user(o + i, rinfo + i, offsetof(sg_req_info_t, usr_ptr)) ||
 907		    put_user((uintptr_t)rinfo[i].usr_ptr, &o[i].usr_ptr) ||
 908		    put_user(rinfo[i].duration, &o[i].duration) ||
 909		    put_user(rinfo[i].unused, &o[i].unused))
 910			return -EFAULT;
 911	}
 912	return 0;
 913}
 914#endif
 915
 916static long
 917sg_ioctl_common(struct file *filp, Sg_device *sdp, Sg_fd *sfp,
 918		unsigned int cmd_in, void __user *p)
 919{
 920	int __user *ip = p;
 921	int result, val, read_only;
 922	Sg_request *srp;
 923	unsigned long iflags;
 924
 925	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 926				   "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
 927	read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 928
 929	switch (cmd_in) {
 930	case SG_IO:
 931		if (atomic_read(&sdp->detaching))
 932			return -ENODEV;
 933		if (!scsi_block_when_processing_errors(sdp->device))
 934			return -ENXIO;
 935		result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 936				 1, read_only, 1, &srp);
 937		if (result < 0)
 938			return result;
 939		result = wait_event_interruptible(sfp->read_wait,
 940			srp_done(sfp, srp));
 941		write_lock_irq(&sfp->rq_list_lock);
 942		if (srp->done) {
 943			srp->done = 2;
 944			write_unlock_irq(&sfp->rq_list_lock);
 945			result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 946			return (result < 0) ? result : 0;
 947		}
 948		srp->orphan = 1;
 949		write_unlock_irq(&sfp->rq_list_lock);
 950		return result;	/* -ERESTARTSYS because signal hit process */
 951	case SG_SET_TIMEOUT:
 952		result = get_user(val, ip);
 953		if (result)
 954			return result;
 955		if (val < 0)
 956			return -EIO;
 957		if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
 958			val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
 959				    INT_MAX);
 960		sfp->timeout_user = val;
 961		sfp->timeout = mult_frac(val, HZ, USER_HZ);
 962
 963		return 0;
 964	case SG_GET_TIMEOUT:	/* N.B. User receives timeout as return value */
 965				/* strange ..., for backward compatibility */
 966		return sfp->timeout_user;
 967	case SG_SET_FORCE_LOW_DMA:
 968		/*
 969		 * N.B. This ioctl never worked properly, but failed to
 970		 * return an error value. So returning '0' to keep compability
 971		 * with legacy applications.
 972		 */
 973		return 0;
 974	case SG_GET_LOW_DMA:
 975		return put_user(0, ip);
 976	case SG_GET_SCSI_ID:
 977		{
 978			sg_scsi_id_t v;
 979
 980			if (atomic_read(&sdp->detaching))
 981				return -ENODEV;
 982			memset(&v, 0, sizeof(v));
 983			v.host_no = sdp->device->host->host_no;
 984			v.channel = sdp->device->channel;
 985			v.scsi_id = sdp->device->id;
 986			v.lun = sdp->device->lun;
 987			v.scsi_type = sdp->device->type;
 988			v.h_cmd_per_lun = sdp->device->host->cmd_per_lun;
 989			v.d_queue_depth = sdp->device->queue_depth;
 990			if (copy_to_user(p, &v, sizeof(sg_scsi_id_t)))
 991				return -EFAULT;
 992			return 0;
 993		}
 994	case SG_SET_FORCE_PACK_ID:
 995		result = get_user(val, ip);
 996		if (result)
 997			return result;
 998		sfp->force_packid = val ? 1 : 0;
 999		return 0;
1000	case SG_GET_PACK_ID:
1001		read_lock_irqsave(&sfp->rq_list_lock, iflags);
1002		list_for_each_entry(srp, &sfp->rq_list, entry) {
1003			if ((1 == srp->done) && (!srp->sg_io_owned)) {
1004				read_unlock_irqrestore(&sfp->rq_list_lock,
1005						       iflags);
1006				return put_user(srp->header.pack_id, ip);
1007			}
1008		}
1009		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1010		return put_user(-1, ip);
1011	case SG_GET_NUM_WAITING:
1012		read_lock_irqsave(&sfp->rq_list_lock, iflags);
1013		val = 0;
1014		list_for_each_entry(srp, &sfp->rq_list, entry) {
1015			if ((1 == srp->done) && (!srp->sg_io_owned))
1016				++val;
1017		}
1018		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1019		return put_user(val, ip);
1020	case SG_GET_SG_TABLESIZE:
1021		return put_user(sdp->sg_tablesize, ip);
1022	case SG_SET_RESERVED_SIZE:
1023		result = get_user(val, ip);
1024		if (result)
1025			return result;
1026                if (val < 0)
1027                        return -EINVAL;
1028		val = min_t(int, val,
1029			    max_sectors_bytes(sdp->device->request_queue));
1030		mutex_lock(&sfp->f_mutex);
1031		if (val != sfp->reserve.bufflen) {
1032			if (sfp->mmap_called ||
1033			    sfp->res_in_use) {
1034				mutex_unlock(&sfp->f_mutex);
1035				return -EBUSY;
1036			}
1037
1038			sg_remove_scat(sfp, &sfp->reserve);
1039			sg_build_reserve(sfp, val);
1040		}
1041		mutex_unlock(&sfp->f_mutex);
1042		return 0;
1043	case SG_GET_RESERVED_SIZE:
1044		val = min_t(int, sfp->reserve.bufflen,
1045			    max_sectors_bytes(sdp->device->request_queue));
1046		return put_user(val, ip);
1047	case SG_SET_COMMAND_Q:
1048		result = get_user(val, ip);
1049		if (result)
1050			return result;
1051		sfp->cmd_q = val ? 1 : 0;
1052		return 0;
1053	case SG_GET_COMMAND_Q:
1054		return put_user((int) sfp->cmd_q, ip);
1055	case SG_SET_KEEP_ORPHAN:
1056		result = get_user(val, ip);
1057		if (result)
1058			return result;
1059		sfp->keep_orphan = val;
1060		return 0;
1061	case SG_GET_KEEP_ORPHAN:
1062		return put_user((int) sfp->keep_orphan, ip);
1063	case SG_NEXT_CMD_LEN:
1064		result = get_user(val, ip);
1065		if (result)
1066			return result;
1067		if (val > SG_MAX_CDB_SIZE)
1068			return -ENOMEM;
1069		sfp->next_cmd_len = (val > 0) ? val : 0;
1070		return 0;
1071	case SG_GET_VERSION_NUM:
1072		return put_user(sg_version_num, ip);
1073	case SG_GET_ACCESS_COUNT:
1074		/* faked - we don't have a real access count anymore */
1075		val = (sdp->device ? 1 : 0);
1076		return put_user(val, ip);
1077	case SG_GET_REQUEST_TABLE:
1078		{
1079			sg_req_info_t *rinfo;
1080
1081			rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
1082					GFP_KERNEL);
1083			if (!rinfo)
1084				return -ENOMEM;
1085			read_lock_irqsave(&sfp->rq_list_lock, iflags);
1086			sg_fill_request_table(sfp, rinfo);
1087			read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1088	#ifdef CONFIG_COMPAT
1089			if (in_compat_syscall())
1090				result = put_compat_request_table(p, rinfo);
1091			else
1092	#endif
1093				result = copy_to_user(p, rinfo,
1094						      SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1095			result = result ? -EFAULT : 0;
1096			kfree(rinfo);
1097			return result;
1098		}
1099	case SG_EMULATED_HOST:
1100		if (atomic_read(&sdp->detaching))
1101			return -ENODEV;
1102		return put_user(sdp->device->host->hostt->emulated, ip);
1103	case SCSI_IOCTL_SEND_COMMAND:
1104		if (atomic_read(&sdp->detaching))
1105			return -ENODEV;
1106		return scsi_ioctl(sdp->device, filp->f_mode & FMODE_WRITE,
1107				  cmd_in, p);
1108	case SG_SET_DEBUG:
1109		result = get_user(val, ip);
1110		if (result)
1111			return result;
1112		sdp->sgdebug = (char) val;
1113		return 0;
1114	case BLKSECTGET:
1115		return put_user(max_sectors_bytes(sdp->device->request_queue),
1116				ip);
1117	case BLKTRACESETUP:
1118		return blk_trace_setup(sdp->device->request_queue, sdp->name,
1119				       MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1120				       NULL, p);
1121	case BLKTRACESTART:
1122		return blk_trace_startstop(sdp->device->request_queue, 1);
1123	case BLKTRACESTOP:
1124		return blk_trace_startstop(sdp->device->request_queue, 0);
1125	case BLKTRACETEARDOWN:
1126		return blk_trace_remove(sdp->device->request_queue);
1127	case SCSI_IOCTL_GET_IDLUN:
1128	case SCSI_IOCTL_GET_BUS_NUMBER:
1129	case SCSI_IOCTL_PROBE_HOST:
1130	case SG_GET_TRANSFORM:
1131	case SG_SCSI_RESET:
1132		if (atomic_read(&sdp->detaching))
1133			return -ENODEV;
1134		break;
1135	default:
1136		if (read_only)
1137			return -EPERM;	/* don't know so take safe approach */
1138		break;
1139	}
1140
1141	result = scsi_ioctl_block_when_processing_errors(sdp->device,
1142			cmd_in, filp->f_flags & O_NDELAY);
1143	if (result)
1144		return result;
1145
1146	return -ENOIOCTLCMD;
1147}
1148
1149static long
1150sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1151{
1152	void __user *p = (void __user *)arg;
1153	Sg_device *sdp;
1154	Sg_fd *sfp;
1155	int ret;
1156
1157	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1158		return -ENXIO;
1159
1160	ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
1161	if (ret != -ENOIOCTLCMD)
1162		return ret;
1163	return scsi_ioctl(sdp->device, filp->f_mode & FMODE_WRITE, cmd_in, p);
1164}
1165
1166static __poll_t
1167sg_poll(struct file *filp, poll_table * wait)
1168{
1169	__poll_t res = 0;
1170	Sg_device *sdp;
1171	Sg_fd *sfp;
1172	Sg_request *srp;
1173	int count = 0;
1174	unsigned long iflags;
1175
1176	sfp = filp->private_data;
1177	if (!sfp)
1178		return EPOLLERR;
1179	sdp = sfp->parentdp;
1180	if (!sdp)
1181		return EPOLLERR;
1182	poll_wait(filp, &sfp->read_wait, wait);
1183	read_lock_irqsave(&sfp->rq_list_lock, iflags);
1184	list_for_each_entry(srp, &sfp->rq_list, entry) {
1185		/* if any read waiting, flag it */
1186		if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1187			res = EPOLLIN | EPOLLRDNORM;
1188		++count;
1189	}
1190	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1191
1192	if (atomic_read(&sdp->detaching))
1193		res |= EPOLLHUP;
1194	else if (!sfp->cmd_q) {
1195		if (0 == count)
1196			res |= EPOLLOUT | EPOLLWRNORM;
1197	} else if (count < SG_MAX_QUEUE)
1198		res |= EPOLLOUT | EPOLLWRNORM;
1199	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1200				      "sg_poll: res=0x%x\n", (__force u32) res));
1201	return res;
1202}
1203
1204static int
1205sg_fasync(int fd, struct file *filp, int mode)
1206{
1207	Sg_device *sdp;
1208	Sg_fd *sfp;
1209
1210	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1211		return -ENXIO;
1212	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1213				      "sg_fasync: mode=%d\n", mode));
1214
1215	return fasync_helper(fd, filp, mode, &sfp->async_qp);
1216}
1217
1218static vm_fault_t
1219sg_vma_fault(struct vm_fault *vmf)
1220{
1221	struct vm_area_struct *vma = vmf->vma;
1222	Sg_fd *sfp;
1223	unsigned long offset, len, sa;
1224	Sg_scatter_hold *rsv_schp;
1225	int k, length;
1226
1227	if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1228		return VM_FAULT_SIGBUS;
1229	rsv_schp = &sfp->reserve;
1230	offset = vmf->pgoff << PAGE_SHIFT;
1231	if (offset >= rsv_schp->bufflen)
1232		return VM_FAULT_SIGBUS;
1233	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1234				      "sg_vma_fault: offset=%lu, scatg=%d\n",
1235				      offset, rsv_schp->k_use_sg));
1236	sa = vma->vm_start;
1237	length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1238	for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1239		len = vma->vm_end - sa;
1240		len = (len < length) ? len : length;
1241		if (offset < len) {
1242			struct page *page = nth_page(rsv_schp->pages[k],
1243						     offset >> PAGE_SHIFT);
1244			get_page(page);	/* increment page count */
1245			vmf->page = page;
1246			return 0; /* success */
1247		}
1248		sa += len;
1249		offset -= len;
1250	}
1251
1252	return VM_FAULT_SIGBUS;
1253}
1254
1255static const struct vm_operations_struct sg_mmap_vm_ops = {
1256	.fault = sg_vma_fault,
1257};
1258
1259static int
1260sg_mmap(struct file *filp, struct vm_area_struct *vma)
1261{
1262	Sg_fd *sfp;
1263	unsigned long req_sz, len, sa;
1264	Sg_scatter_hold *rsv_schp;
1265	int k, length;
1266	int ret = 0;
1267
1268	if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1269		return -ENXIO;
1270	req_sz = vma->vm_end - vma->vm_start;
1271	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1272				      "sg_mmap starting, vm_start=%p, len=%d\n",
1273				      (void *) vma->vm_start, (int) req_sz));
1274	if (vma->vm_pgoff)
1275		return -EINVAL;	/* want no offset */
1276	rsv_schp = &sfp->reserve;
1277	mutex_lock(&sfp->f_mutex);
1278	if (req_sz > rsv_schp->bufflen) {
1279		ret = -ENOMEM;	/* cannot map more than reserved buffer */
1280		goto out;
1281	}
1282
1283	sa = vma->vm_start;
1284	length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1285	for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1286		len = vma->vm_end - sa;
1287		len = (len < length) ? len : length;
1288		sa += len;
1289	}
1290
1291	sfp->mmap_called = 1;
1292	vm_flags_set(vma, VM_IO | VM_DONTEXPAND | VM_DONTDUMP);
1293	vma->vm_private_data = sfp;
1294	vma->vm_ops = &sg_mmap_vm_ops;
1295out:
1296	mutex_unlock(&sfp->f_mutex);
1297	return ret;
1298}
1299
1300static void
1301sg_rq_end_io_usercontext(struct work_struct *work)
1302{
1303	struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1304	struct sg_fd *sfp = srp->parentfp;
1305
1306	sg_finish_rem_req(srp);
1307	sg_remove_request(sfp, srp);
1308	kref_put(&sfp->f_ref, sg_remove_sfp);
1309}
1310
1311/*
1312 * This function is a "bottom half" handler that is called by the mid
1313 * level when a command is completed (or has failed).
1314 */
1315static enum rq_end_io_ret
1316sg_rq_end_io(struct request *rq, blk_status_t status)
1317{
1318	struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
1319	struct sg_request *srp = rq->end_io_data;
1320	Sg_device *sdp;
1321	Sg_fd *sfp;
1322	unsigned long iflags;
1323	unsigned int ms;
1324	char *sense;
1325	int result, resid, done = 1;
1326
1327	if (WARN_ON(srp->done != 0))
1328		return RQ_END_IO_NONE;
1329
1330	sfp = srp->parentfp;
1331	if (WARN_ON(sfp == NULL))
1332		return RQ_END_IO_NONE;
1333
1334	sdp = sfp->parentdp;
1335	if (unlikely(atomic_read(&sdp->detaching)))
1336		pr_info("%s: device detaching\n", __func__);
1337
1338	sense = scmd->sense_buffer;
1339	result = scmd->result;
1340	resid = scmd->resid_len;
1341
1342	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1343				      "sg_cmd_done: pack_id=%d, res=0x%x\n",
1344				      srp->header.pack_id, result));
1345	srp->header.resid = resid;
1346	ms = jiffies_to_msecs(jiffies);
1347	srp->header.duration = (ms > srp->header.duration) ?
1348				(ms - srp->header.duration) : 0;
1349	if (0 != result) {
1350		struct scsi_sense_hdr sshdr;
1351
1352		srp->header.status = 0xff & result;
1353		srp->header.masked_status = sg_status_byte(result);
1354		srp->header.msg_status = COMMAND_COMPLETE;
1355		srp->header.host_status = host_byte(result);
1356		srp->header.driver_status = driver_byte(result);
1357		if ((sdp->sgdebug > 0) &&
1358		    ((CHECK_CONDITION == srp->header.masked_status) ||
1359		     (COMMAND_TERMINATED == srp->header.masked_status)))
1360			__scsi_print_sense(sdp->device, __func__, sense,
1361					   SCSI_SENSE_BUFFERSIZE);
1362
1363		/* Following if statement is a patch supplied by Eric Youngdale */
1364		if (driver_byte(result) != 0
1365		    && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1366		    && !scsi_sense_is_deferred(&sshdr)
1367		    && sshdr.sense_key == UNIT_ATTENTION
1368		    && sdp->device->removable) {
1369			/* Detected possible disc change. Set the bit - this */
1370			/* may be used if there are filesystems using this device */
1371			sdp->device->changed = 1;
1372		}
1373	}
1374
1375	if (scmd->sense_len)
1376		memcpy(srp->sense_b, scmd->sense_buffer, SCSI_SENSE_BUFFERSIZE);
1377
1378	/* Rely on write phase to clean out srp status values, so no "else" */
1379
1380	/*
1381	 * Free the request as soon as it is complete so that its resources
1382	 * can be reused without waiting for userspace to read() the
1383	 * result.  But keep the associated bio (if any) around until
1384	 * blk_rq_unmap_user() can be called from user context.
1385	 */
1386	srp->rq = NULL;
1387	blk_mq_free_request(rq);
1388
1389	write_lock_irqsave(&sfp->rq_list_lock, iflags);
1390	if (unlikely(srp->orphan)) {
1391		if (sfp->keep_orphan)
1392			srp->sg_io_owned = 0;
1393		else
1394			done = 0;
1395	}
1396	srp->done = done;
1397	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1398
1399	if (likely(done)) {
1400		/* Now wake up any sg_read() that is waiting for this
1401		 * packet.
1402		 */
1403		wake_up_interruptible(&sfp->read_wait);
1404		kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1405		kref_put(&sfp->f_ref, sg_remove_sfp);
1406	} else {
1407		INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1408		schedule_work(&srp->ew.work);
1409	}
1410	return RQ_END_IO_NONE;
1411}
1412
1413static const struct file_operations sg_fops = {
1414	.owner = THIS_MODULE,
1415	.read = sg_read,
1416	.write = sg_write,
1417	.poll = sg_poll,
1418	.unlocked_ioctl = sg_ioctl,
1419	.compat_ioctl = compat_ptr_ioctl,
1420	.open = sg_open,
1421	.mmap = sg_mmap,
1422	.release = sg_release,
1423	.fasync = sg_fasync,
1424	.llseek = no_llseek,
1425};
1426
1427static struct class *sg_sysfs_class;
1428
1429static int sg_sysfs_valid = 0;
1430
1431static Sg_device *
1432sg_alloc(struct scsi_device *scsidp)
1433{
1434	struct request_queue *q = scsidp->request_queue;
1435	Sg_device *sdp;
1436	unsigned long iflags;
1437	int error;
1438	u32 k;
1439
1440	sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1441	if (!sdp) {
1442		sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1443			    "failure\n", __func__);
1444		return ERR_PTR(-ENOMEM);
1445	}
1446
1447	idr_preload(GFP_KERNEL);
1448	write_lock_irqsave(&sg_index_lock, iflags);
1449
1450	error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1451	if (error < 0) {
1452		if (error == -ENOSPC) {
1453			sdev_printk(KERN_WARNING, scsidp,
1454				    "Unable to attach sg device type=%d, minor number exceeds %d\n",
1455				    scsidp->type, SG_MAX_DEVS - 1);
1456			error = -ENODEV;
1457		} else {
1458			sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1459				    "allocation Sg_device failure: %d\n",
1460				    __func__, error);
1461		}
1462		goto out_unlock;
1463	}
1464	k = error;
1465
1466	SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1467					"sg_alloc: dev=%d \n", k));
1468	sprintf(sdp->name, "sg%d", k);
1469	sdp->device = scsidp;
1470	mutex_init(&sdp->open_rel_lock);
1471	INIT_LIST_HEAD(&sdp->sfds);
1472	init_waitqueue_head(&sdp->open_wait);
1473	atomic_set(&sdp->detaching, 0);
1474	rwlock_init(&sdp->sfd_lock);
1475	sdp->sg_tablesize = queue_max_segments(q);
1476	sdp->index = k;
1477	kref_init(&sdp->d_ref);
1478	error = 0;
1479
1480out_unlock:
1481	write_unlock_irqrestore(&sg_index_lock, iflags);
1482	idr_preload_end();
1483
1484	if (error) {
1485		kfree(sdp);
1486		return ERR_PTR(error);
1487	}
1488	return sdp;
1489}
1490
1491static int
1492sg_add_device(struct device *cl_dev)
1493{
1494	struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1495	Sg_device *sdp = NULL;
1496	struct cdev * cdev = NULL;
1497	int error;
1498	unsigned long iflags;
1499
1500	if (!blk_get_queue(scsidp->request_queue)) {
1501		pr_warn("%s: get scsi_device queue failed\n", __func__);
1502		return -ENODEV;
1503	}
1504
1505	error = -ENOMEM;
1506	cdev = cdev_alloc();
1507	if (!cdev) {
1508		pr_warn("%s: cdev_alloc failed\n", __func__);
1509		goto out;
1510	}
1511	cdev->owner = THIS_MODULE;
1512	cdev->ops = &sg_fops;
1513
1514	sdp = sg_alloc(scsidp);
1515	if (IS_ERR(sdp)) {
1516		pr_warn("%s: sg_alloc failed\n", __func__);
1517		error = PTR_ERR(sdp);
1518		goto out;
1519	}
1520
1521	error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1522	if (error)
1523		goto cdev_add_err;
1524
1525	sdp->cdev = cdev;
1526	if (sg_sysfs_valid) {
1527		struct device *sg_class_member;
1528
1529		sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1530						MKDEV(SCSI_GENERIC_MAJOR,
1531						      sdp->index),
1532						sdp, "%s", sdp->name);
1533		if (IS_ERR(sg_class_member)) {
1534			pr_err("%s: device_create failed\n", __func__);
1535			error = PTR_ERR(sg_class_member);
1536			goto cdev_add_err;
1537		}
1538		error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1539					  &sg_class_member->kobj, "generic");
1540		if (error)
1541			pr_err("%s: unable to make symlink 'generic' back "
1542			       "to sg%d\n", __func__, sdp->index);
1543	} else
1544		pr_warn("%s: sg_sys Invalid\n", __func__);
1545
1546	sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1547		    "type %d\n", sdp->index, scsidp->type);
1548
1549	dev_set_drvdata(cl_dev, sdp);
1550
1551	return 0;
1552
1553cdev_add_err:
1554	write_lock_irqsave(&sg_index_lock, iflags);
1555	idr_remove(&sg_index_idr, sdp->index);
1556	write_unlock_irqrestore(&sg_index_lock, iflags);
1557	kfree(sdp);
1558
1559out:
1560	if (cdev)
1561		cdev_del(cdev);
1562	blk_put_queue(scsidp->request_queue);
1563	return error;
1564}
1565
1566static void
1567sg_device_destroy(struct kref *kref)
1568{
1569	struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1570	struct request_queue *q = sdp->device->request_queue;
1571	unsigned long flags;
1572
1573	/* CAUTION!  Note that the device can still be found via idr_find()
1574	 * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1575	 * any other cleanup.
1576	 */
1577
1578	blk_trace_remove(q);
1579	blk_put_queue(q);
1580
1581	write_lock_irqsave(&sg_index_lock, flags);
1582	idr_remove(&sg_index_idr, sdp->index);
1583	write_unlock_irqrestore(&sg_index_lock, flags);
1584
1585	SCSI_LOG_TIMEOUT(3,
1586		sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1587
1588	kfree(sdp);
1589}
1590
1591static void
1592sg_remove_device(struct device *cl_dev)
1593{
1594	struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1595	Sg_device *sdp = dev_get_drvdata(cl_dev);
1596	unsigned long iflags;
1597	Sg_fd *sfp;
1598	int val;
1599
1600	if (!sdp)
1601		return;
1602	/* want sdp->detaching non-zero as soon as possible */
1603	val = atomic_inc_return(&sdp->detaching);
1604	if (val > 1)
1605		return; /* only want to do following once per device */
1606
1607	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1608				      "%s\n", __func__));
1609
1610	read_lock_irqsave(&sdp->sfd_lock, iflags);
1611	list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1612		wake_up_interruptible_all(&sfp->read_wait);
1613		kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1614	}
1615	wake_up_interruptible_all(&sdp->open_wait);
1616	read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1617
1618	sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1619	device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1620	cdev_del(sdp->cdev);
1621	sdp->cdev = NULL;
1622
1623	kref_put(&sdp->d_ref, sg_device_destroy);
1624}
1625
1626module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1627module_param_named(def_reserved_size, def_reserved_size, int,
1628		   S_IRUGO | S_IWUSR);
1629module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1630
1631MODULE_AUTHOR("Douglas Gilbert");
1632MODULE_DESCRIPTION("SCSI generic (sg) driver");
1633MODULE_LICENSE("GPL");
1634MODULE_VERSION(SG_VERSION_STR);
1635MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1636
1637MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1638                "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1639MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1640MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1641
1642#ifdef CONFIG_SYSCTL
1643#include <linux/sysctl.h>
1644
1645static struct ctl_table sg_sysctls[] = {
1646	{
1647		.procname	= "sg-big-buff",
1648		.data		= &sg_big_buff,
1649		.maxlen		= sizeof(int),
1650		.mode		= 0444,
1651		.proc_handler	= proc_dointvec,
1652	},
 
1653};
1654
1655static struct ctl_table_header *hdr;
1656static void register_sg_sysctls(void)
1657{
1658	if (!hdr)
1659		hdr = register_sysctl("kernel", sg_sysctls);
1660}
1661
1662static void unregister_sg_sysctls(void)
1663{
1664	if (hdr)
1665		unregister_sysctl_table(hdr);
1666}
1667#else
1668#define register_sg_sysctls() do { } while (0)
1669#define unregister_sg_sysctls() do { } while (0)
1670#endif /* CONFIG_SYSCTL */
1671
1672static int __init
1673init_sg(void)
1674{
1675	int rc;
1676
1677	if (scatter_elem_sz < PAGE_SIZE) {
1678		scatter_elem_sz = PAGE_SIZE;
1679		scatter_elem_sz_prev = scatter_elem_sz;
1680	}
1681	if (def_reserved_size >= 0)
1682		sg_big_buff = def_reserved_size;
1683	else
1684		def_reserved_size = sg_big_buff;
1685
1686	rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), 
1687				    SG_MAX_DEVS, "sg");
1688	if (rc)
1689		return rc;
1690        sg_sysfs_class = class_create("scsi_generic");
1691        if ( IS_ERR(sg_sysfs_class) ) {
1692		rc = PTR_ERR(sg_sysfs_class);
1693		goto err_out;
1694        }
1695	sg_sysfs_valid = 1;
1696	rc = scsi_register_interface(&sg_interface);
1697	if (0 == rc) {
1698#ifdef CONFIG_SCSI_PROC_FS
1699		sg_proc_init();
1700#endif				/* CONFIG_SCSI_PROC_FS */
1701		return 0;
1702	}
1703	class_destroy(sg_sysfs_class);
1704	register_sg_sysctls();
1705err_out:
1706	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1707	return rc;
1708}
1709
1710static void __exit
1711exit_sg(void)
1712{
1713	unregister_sg_sysctls();
1714#ifdef CONFIG_SCSI_PROC_FS
1715	remove_proc_subtree("scsi/sg", NULL);
1716#endif				/* CONFIG_SCSI_PROC_FS */
1717	scsi_unregister_interface(&sg_interface);
1718	class_destroy(sg_sysfs_class);
1719	sg_sysfs_valid = 0;
1720	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1721				 SG_MAX_DEVS);
1722	idr_destroy(&sg_index_idr);
1723}
1724
1725static int
1726sg_start_req(Sg_request *srp, unsigned char *cmd)
1727{
1728	int res;
1729	struct request *rq;
1730	Sg_fd *sfp = srp->parentfp;
1731	sg_io_hdr_t *hp = &srp->header;
1732	int dxfer_len = (int) hp->dxfer_len;
1733	int dxfer_dir = hp->dxfer_direction;
1734	unsigned int iov_count = hp->iovec_count;
1735	Sg_scatter_hold *req_schp = &srp->data;
1736	Sg_scatter_hold *rsv_schp = &sfp->reserve;
1737	struct request_queue *q = sfp->parentdp->device->request_queue;
1738	struct rq_map_data *md, map_data;
1739	int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? ITER_SOURCE : ITER_DEST;
1740	struct scsi_cmnd *scmd;
1741
1742	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1743				      "sg_start_req: dxfer_len=%d\n",
1744				      dxfer_len));
1745
1746	/*
1747	 * NOTE
1748	 *
1749	 * With scsi-mq enabled, there are a fixed number of preallocated
1750	 * requests equal in number to shost->can_queue.  If all of the
1751	 * preallocated requests are already in use, then scsi_alloc_request()
1752	 * will sleep until an active command completes, freeing up a request.
1753	 * Although waiting in an asynchronous interface is less than ideal, we
1754	 * do not want to use BLK_MQ_REQ_NOWAIT here because userspace might
1755	 * not expect an EWOULDBLOCK from this condition.
1756	 */
1757	rq = scsi_alloc_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
1758			REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
1759	if (IS_ERR(rq))
1760		return PTR_ERR(rq);
1761	scmd = blk_mq_rq_to_pdu(rq);
1762
1763	if (hp->cmd_len > sizeof(scmd->cmnd)) {
1764		blk_mq_free_request(rq);
1765		return -EINVAL;
1766	}
1767
1768	memcpy(scmd->cmnd, cmd, hp->cmd_len);
1769	scmd->cmd_len = hp->cmd_len;
1770
1771	srp->rq = rq;
1772	rq->end_io_data = srp;
1773	scmd->allowed = SG_DEFAULT_RETRIES;
1774
1775	if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1776		return 0;
1777
1778	if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1779	    dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1780	    blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1781		md = NULL;
1782	else
1783		md = &map_data;
1784
1785	if (md) {
1786		mutex_lock(&sfp->f_mutex);
1787		if (dxfer_len <= rsv_schp->bufflen &&
1788		    !sfp->res_in_use) {
1789			sfp->res_in_use = 1;
1790			sg_link_reserve(sfp, srp, dxfer_len);
1791		} else if (hp->flags & SG_FLAG_MMAP_IO) {
1792			res = -EBUSY; /* sfp->res_in_use == 1 */
1793			if (dxfer_len > rsv_schp->bufflen)
1794				res = -ENOMEM;
1795			mutex_unlock(&sfp->f_mutex);
1796			return res;
1797		} else {
1798			res = sg_build_indirect(req_schp, sfp, dxfer_len);
1799			if (res) {
1800				mutex_unlock(&sfp->f_mutex);
1801				return res;
1802			}
1803		}
1804		mutex_unlock(&sfp->f_mutex);
1805
1806		md->pages = req_schp->pages;
1807		md->page_order = req_schp->page_order;
1808		md->nr_entries = req_schp->k_use_sg;
1809		md->offset = 0;
1810		md->null_mapped = hp->dxferp ? 0 : 1;
1811		if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1812			md->from_user = 1;
1813		else
1814			md->from_user = 0;
1815	}
1816
1817	res = blk_rq_map_user_io(rq, md, hp->dxferp, hp->dxfer_len,
1818			GFP_ATOMIC, iov_count, iov_count, 1, rw);
1819	if (!res) {
1820		srp->bio = rq->bio;
1821
1822		if (!md) {
1823			req_schp->dio_in_use = 1;
1824			hp->info |= SG_INFO_DIRECT_IO;
1825		}
1826	}
1827	return res;
1828}
1829
1830static int
1831sg_finish_rem_req(Sg_request *srp)
1832{
1833	int ret = 0;
1834
1835	Sg_fd *sfp = srp->parentfp;
1836	Sg_scatter_hold *req_schp = &srp->data;
1837
1838	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1839				      "sg_finish_rem_req: res_used=%d\n",
1840				      (int) srp->res_used));
1841	if (srp->bio)
1842		ret = blk_rq_unmap_user(srp->bio);
1843
1844	if (srp->rq)
1845		blk_mq_free_request(srp->rq);
1846
1847	if (srp->res_used)
1848		sg_unlink_reserve(sfp, srp);
1849	else
1850		sg_remove_scat(sfp, req_schp);
1851
1852	return ret;
1853}
1854
1855static int
1856sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1857{
1858	int sg_bufflen = tablesize * sizeof(struct page *);
1859	gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1860
1861	schp->pages = kzalloc(sg_bufflen, gfp_flags);
1862	if (!schp->pages)
1863		return -ENOMEM;
1864	schp->sglist_len = sg_bufflen;
1865	return tablesize;	/* number of scat_gath elements allocated */
1866}
1867
1868static int
1869sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1870{
1871	int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1872	int sg_tablesize = sfp->parentdp->sg_tablesize;
1873	int blk_size = buff_size, order;
1874	gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
1875
1876	if (blk_size < 0)
1877		return -EFAULT;
1878	if (0 == blk_size)
1879		++blk_size;	/* don't know why */
1880	/* round request up to next highest SG_SECTOR_SZ byte boundary */
1881	blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1882	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1883		"sg_build_indirect: buff_size=%d, blk_size=%d\n",
1884		buff_size, blk_size));
1885
1886	/* N.B. ret_sz carried into this block ... */
1887	mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1888	if (mx_sc_elems < 0)
1889		return mx_sc_elems;	/* most likely -ENOMEM */
1890
1891	num = scatter_elem_sz;
1892	if (unlikely(num != scatter_elem_sz_prev)) {
1893		if (num < PAGE_SIZE) {
1894			scatter_elem_sz = PAGE_SIZE;
1895			scatter_elem_sz_prev = PAGE_SIZE;
1896		} else
1897			scatter_elem_sz_prev = num;
1898	}
1899
1900	order = get_order(num);
1901retry:
1902	ret_sz = 1 << (PAGE_SHIFT + order);
1903
1904	for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1905	     k++, rem_sz -= ret_sz) {
1906
1907		num = (rem_sz > scatter_elem_sz_prev) ?
1908			scatter_elem_sz_prev : rem_sz;
1909
1910		schp->pages[k] = alloc_pages(gfp_mask, order);
1911		if (!schp->pages[k])
1912			goto out;
1913
1914		if (num == scatter_elem_sz_prev) {
1915			if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1916				scatter_elem_sz = ret_sz;
1917				scatter_elem_sz_prev = ret_sz;
1918			}
1919		}
1920
1921		SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1922				 "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1923				 k, num, ret_sz));
1924	}		/* end of for loop */
1925
1926	schp->page_order = order;
1927	schp->k_use_sg = k;
1928	SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1929			 "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1930			 k, rem_sz));
1931
1932	schp->bufflen = blk_size;
1933	if (rem_sz > 0)	/* must have failed */
1934		return -ENOMEM;
1935	return 0;
1936out:
1937	for (i = 0; i < k; i++)
1938		__free_pages(schp->pages[i], order);
1939
1940	if (--order >= 0)
1941		goto retry;
1942
1943	return -ENOMEM;
1944}
1945
1946static void
1947sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1948{
1949	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1950			 "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1951	if (schp->pages && schp->sglist_len > 0) {
1952		if (!schp->dio_in_use) {
1953			int k;
1954
1955			for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1956				SCSI_LOG_TIMEOUT(5,
1957					sg_printk(KERN_INFO, sfp->parentdp,
1958					"sg_remove_scat: k=%d, pg=0x%p\n",
1959					k, schp->pages[k]));
1960				__free_pages(schp->pages[k], schp->page_order);
1961			}
1962
1963			kfree(schp->pages);
1964		}
1965	}
1966	memset(schp, 0, sizeof (*schp));
1967}
1968
1969static int
1970sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1971{
1972	Sg_scatter_hold *schp = &srp->data;
1973	int k, num;
1974
1975	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1976			 "sg_read_oxfer: num_read_xfer=%d\n",
1977			 num_read_xfer));
1978	if ((!outp) || (num_read_xfer <= 0))
1979		return 0;
1980
1981	num = 1 << (PAGE_SHIFT + schp->page_order);
1982	for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1983		if (num > num_read_xfer) {
1984			if (copy_to_user(outp, page_address(schp->pages[k]),
1985					   num_read_xfer))
1986				return -EFAULT;
1987			break;
1988		} else {
1989			if (copy_to_user(outp, page_address(schp->pages[k]),
1990					   num))
1991				return -EFAULT;
1992			num_read_xfer -= num;
1993			if (num_read_xfer <= 0)
1994				break;
1995			outp += num;
1996		}
1997	}
1998
1999	return 0;
2000}
2001
2002static void
2003sg_build_reserve(Sg_fd * sfp, int req_size)
2004{
2005	Sg_scatter_hold *schp = &sfp->reserve;
2006
2007	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2008			 "sg_build_reserve: req_size=%d\n", req_size));
2009	do {
2010		if (req_size < PAGE_SIZE)
2011			req_size = PAGE_SIZE;
2012		if (0 == sg_build_indirect(schp, sfp, req_size))
2013			return;
2014		else
2015			sg_remove_scat(sfp, schp);
2016		req_size >>= 1;	/* divide by 2 */
2017	} while (req_size > (PAGE_SIZE / 2));
2018}
2019
2020static void
2021sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2022{
2023	Sg_scatter_hold *req_schp = &srp->data;
2024	Sg_scatter_hold *rsv_schp = &sfp->reserve;
2025	int k, num, rem;
2026
2027	srp->res_used = 1;
2028	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2029			 "sg_link_reserve: size=%d\n", size));
2030	rem = size;
2031
2032	num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
2033	for (k = 0; k < rsv_schp->k_use_sg; k++) {
2034		if (rem <= num) {
2035			req_schp->k_use_sg = k + 1;
2036			req_schp->sglist_len = rsv_schp->sglist_len;
2037			req_schp->pages = rsv_schp->pages;
2038
2039			req_schp->bufflen = size;
2040			req_schp->page_order = rsv_schp->page_order;
2041			break;
2042		} else
2043			rem -= num;
2044	}
2045
2046	if (k >= rsv_schp->k_use_sg)
2047		SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2048				 "sg_link_reserve: BAD size\n"));
2049}
2050
2051static void
2052sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2053{
2054	Sg_scatter_hold *req_schp = &srp->data;
2055
2056	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2057				      "sg_unlink_reserve: req->k_use_sg=%d\n",
2058				      (int) req_schp->k_use_sg));
2059	req_schp->k_use_sg = 0;
2060	req_schp->bufflen = 0;
2061	req_schp->pages = NULL;
2062	req_schp->page_order = 0;
2063	req_schp->sglist_len = 0;
2064	srp->res_used = 0;
2065	/* Called without mutex lock to avoid deadlock */
2066	sfp->res_in_use = 0;
2067}
2068
2069static Sg_request *
2070sg_get_rq_mark(Sg_fd * sfp, int pack_id, bool *busy)
2071{
2072	Sg_request *resp;
2073	unsigned long iflags;
2074
2075	*busy = false;
2076	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2077	list_for_each_entry(resp, &sfp->rq_list, entry) {
2078		/* look for requests that are not SG_IO owned */
2079		if ((!resp->sg_io_owned) &&
2080		    ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2081			switch (resp->done) {
2082			case 0: /* request active */
2083				*busy = true;
2084				break;
2085			case 1: /* request done; response ready to return */
2086				resp->done = 2;	/* guard against other readers */
2087				write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2088				return resp;
2089			case 2: /* response already being returned */
2090				break;
2091			}
2092		}
2093	}
2094	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2095	return NULL;
2096}
2097
2098/* always adds to end of list */
2099static Sg_request *
2100sg_add_request(Sg_fd * sfp)
2101{
2102	int k;
2103	unsigned long iflags;
2104	Sg_request *rp = sfp->req_arr;
2105
2106	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2107	if (!list_empty(&sfp->rq_list)) {
2108		if (!sfp->cmd_q)
2109			goto out_unlock;
2110
2111		for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2112			if (!rp->parentfp)
2113				break;
2114		}
2115		if (k >= SG_MAX_QUEUE)
2116			goto out_unlock;
2117	}
2118	memset(rp, 0, sizeof (Sg_request));
2119	rp->parentfp = sfp;
2120	rp->header.duration = jiffies_to_msecs(jiffies);
2121	list_add_tail(&rp->entry, &sfp->rq_list);
2122	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2123	return rp;
2124out_unlock:
2125	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2126	return NULL;
2127}
2128
2129/* Return of 1 for found; 0 for not found */
2130static int
2131sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2132{
2133	unsigned long iflags;
2134	int res = 0;
2135
2136	if (!sfp || !srp || list_empty(&sfp->rq_list))
2137		return res;
2138	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2139	if (!list_empty(&srp->entry)) {
2140		list_del(&srp->entry);
2141		srp->parentfp = NULL;
2142		res = 1;
2143	}
2144	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2145
2146	/*
2147	 * If the device is detaching, wakeup any readers in case we just
2148	 * removed the last response, which would leave nothing for them to
2149	 * return other than -ENODEV.
2150	 */
2151	if (unlikely(atomic_read(&sfp->parentdp->detaching)))
2152		wake_up_interruptible_all(&sfp->read_wait);
2153
2154	return res;
2155}
2156
2157static Sg_fd *
2158sg_add_sfp(Sg_device * sdp)
2159{
2160	Sg_fd *sfp;
2161	unsigned long iflags;
2162	int bufflen;
2163
2164	sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2165	if (!sfp)
2166		return ERR_PTR(-ENOMEM);
2167
2168	init_waitqueue_head(&sfp->read_wait);
2169	rwlock_init(&sfp->rq_list_lock);
2170	INIT_LIST_HEAD(&sfp->rq_list);
2171	kref_init(&sfp->f_ref);
2172	mutex_init(&sfp->f_mutex);
2173	sfp->timeout = SG_DEFAULT_TIMEOUT;
2174	sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2175	sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2176	sfp->cmd_q = SG_DEF_COMMAND_Q;
2177	sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2178	sfp->parentdp = sdp;
2179	write_lock_irqsave(&sdp->sfd_lock, iflags);
2180	if (atomic_read(&sdp->detaching)) {
2181		write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2182		kfree(sfp);
2183		return ERR_PTR(-ENODEV);
2184	}
2185	list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2186	write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2187	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2188				      "sg_add_sfp: sfp=0x%p\n", sfp));
2189	if (unlikely(sg_big_buff != def_reserved_size))
2190		sg_big_buff = def_reserved_size;
2191
2192	bufflen = min_t(int, sg_big_buff,
2193			max_sectors_bytes(sdp->device->request_queue));
2194	sg_build_reserve(sfp, bufflen);
2195	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2196				      "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2197				      sfp->reserve.bufflen,
2198				      sfp->reserve.k_use_sg));
2199
2200	kref_get(&sdp->d_ref);
2201	__module_get(THIS_MODULE);
2202	return sfp;
2203}
2204
2205static void
2206sg_remove_sfp_usercontext(struct work_struct *work)
2207{
2208	struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2209	struct sg_device *sdp = sfp->parentdp;
2210	Sg_request *srp;
2211	unsigned long iflags;
2212
2213	/* Cleanup any responses which were never read(). */
2214	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2215	while (!list_empty(&sfp->rq_list)) {
2216		srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2217		sg_finish_rem_req(srp);
2218		list_del(&srp->entry);
2219		srp->parentfp = NULL;
2220	}
2221	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2222
2223	if (sfp->reserve.bufflen > 0) {
2224		SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2225				"sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2226				(int) sfp->reserve.bufflen,
2227				(int) sfp->reserve.k_use_sg));
2228		sg_remove_scat(sfp, &sfp->reserve);
2229	}
2230
2231	SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2232			"sg_remove_sfp: sfp=0x%p\n", sfp));
2233	kfree(sfp);
2234
2235	scsi_device_put(sdp->device);
2236	kref_put(&sdp->d_ref, sg_device_destroy);
2237	module_put(THIS_MODULE);
2238}
2239
2240static void
2241sg_remove_sfp(struct kref *kref)
2242{
2243	struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2244	struct sg_device *sdp = sfp->parentdp;
2245	unsigned long iflags;
2246
2247	write_lock_irqsave(&sdp->sfd_lock, iflags);
2248	list_del(&sfp->sfd_siblings);
2249	write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2250
2251	INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2252	schedule_work(&sfp->ew.work);
2253}
2254
2255#ifdef CONFIG_SCSI_PROC_FS
2256static int
2257sg_idr_max_id(int id, void *p, void *data)
2258{
2259	int *k = data;
2260
2261	if (*k < id)
2262		*k = id;
2263
2264	return 0;
2265}
2266
2267static int
2268sg_last_dev(void)
2269{
2270	int k = -1;
2271	unsigned long iflags;
2272
2273	read_lock_irqsave(&sg_index_lock, iflags);
2274	idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2275	read_unlock_irqrestore(&sg_index_lock, iflags);
2276	return k + 1;		/* origin 1 */
2277}
2278#endif
2279
2280/* must be called with sg_index_lock held */
2281static Sg_device *sg_lookup_dev(int dev)
2282{
2283	return idr_find(&sg_index_idr, dev);
2284}
2285
2286static Sg_device *
2287sg_get_dev(int dev)
2288{
2289	struct sg_device *sdp;
2290	unsigned long flags;
2291
2292	read_lock_irqsave(&sg_index_lock, flags);
2293	sdp = sg_lookup_dev(dev);
2294	if (!sdp)
2295		sdp = ERR_PTR(-ENXIO);
2296	else if (atomic_read(&sdp->detaching)) {
2297		/* If sdp->detaching, then the refcount may already be 0, in
2298		 * which case it would be a bug to do kref_get().
2299		 */
2300		sdp = ERR_PTR(-ENODEV);
2301	} else
2302		kref_get(&sdp->d_ref);
2303	read_unlock_irqrestore(&sg_index_lock, flags);
2304
2305	return sdp;
2306}
2307
2308#ifdef CONFIG_SCSI_PROC_FS
2309static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2310
2311static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2312static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2313			          size_t count, loff_t *off);
2314static const struct proc_ops adio_proc_ops = {
2315	.proc_open	= sg_proc_single_open_adio,
2316	.proc_read	= seq_read,
2317	.proc_lseek	= seq_lseek,
2318	.proc_write	= sg_proc_write_adio,
2319	.proc_release	= single_release,
2320};
2321
2322static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2323static ssize_t sg_proc_write_dressz(struct file *filp, 
2324		const char __user *buffer, size_t count, loff_t *off);
2325static const struct proc_ops dressz_proc_ops = {
2326	.proc_open	= sg_proc_single_open_dressz,
2327	.proc_read	= seq_read,
2328	.proc_lseek	= seq_lseek,
2329	.proc_write	= sg_proc_write_dressz,
2330	.proc_release	= single_release,
2331};
2332
2333static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2334static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2335static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2336static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2337static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2338static void dev_seq_stop(struct seq_file *s, void *v);
2339static const struct seq_operations dev_seq_ops = {
2340	.start = dev_seq_start,
2341	.next  = dev_seq_next,
2342	.stop  = dev_seq_stop,
2343	.show  = sg_proc_seq_show_dev,
2344};
2345
2346static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2347static const struct seq_operations devstrs_seq_ops = {
2348	.start = dev_seq_start,
2349	.next  = dev_seq_next,
2350	.stop  = dev_seq_stop,
2351	.show  = sg_proc_seq_show_devstrs,
2352};
2353
2354static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2355static const struct seq_operations debug_seq_ops = {
2356	.start = dev_seq_start,
2357	.next  = dev_seq_next,
2358	.stop  = dev_seq_stop,
2359	.show  = sg_proc_seq_show_debug,
2360};
2361
2362static int
2363sg_proc_init(void)
2364{
2365	struct proc_dir_entry *p;
2366
2367	p = proc_mkdir("scsi/sg", NULL);
2368	if (!p)
2369		return 1;
2370
2371	proc_create("allow_dio", S_IRUGO | S_IWUSR, p, &adio_proc_ops);
2372	proc_create_seq("debug", S_IRUGO, p, &debug_seq_ops);
2373	proc_create("def_reserved_size", S_IRUGO | S_IWUSR, p, &dressz_proc_ops);
2374	proc_create_single("device_hdr", S_IRUGO, p, sg_proc_seq_show_devhdr);
2375	proc_create_seq("devices", S_IRUGO, p, &dev_seq_ops);
2376	proc_create_seq("device_strs", S_IRUGO, p, &devstrs_seq_ops);
2377	proc_create_single("version", S_IRUGO, p, sg_proc_seq_show_version);
2378	return 0;
2379}
2380
2381
2382static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2383{
2384	seq_printf(s, "%d\n", *((int *)s->private));
2385	return 0;
2386}
2387
2388static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2389{
2390	return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2391}
2392
2393static ssize_t 
2394sg_proc_write_adio(struct file *filp, const char __user *buffer,
2395		   size_t count, loff_t *off)
2396{
2397	int err;
2398	unsigned long num;
2399
2400	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2401		return -EACCES;
2402	err = kstrtoul_from_user(buffer, count, 0, &num);
2403	if (err)
2404		return err;
2405	sg_allow_dio = num ? 1 : 0;
2406	return count;
2407}
2408
2409static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2410{
2411	return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2412}
2413
2414static ssize_t 
2415sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2416		     size_t count, loff_t *off)
2417{
2418	int err;
2419	unsigned long k = ULONG_MAX;
2420
2421	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2422		return -EACCES;
2423
2424	err = kstrtoul_from_user(buffer, count, 0, &k);
2425	if (err)
2426		return err;
2427	if (k <= 1048576) {	/* limit "big buff" to 1 MB */
2428		sg_big_buff = k;
2429		return count;
2430	}
2431	return -ERANGE;
2432}
2433
2434static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2435{
2436	seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2437		   sg_version_date);
2438	return 0;
2439}
2440
2441static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2442{
2443	seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2444	return 0;
2445}
2446
2447struct sg_proc_deviter {
2448	loff_t	index;
2449	size_t	max;
2450};
2451
2452static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2453{
2454	struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2455
2456	s->private = it;
2457	if (! it)
2458		return NULL;
2459
2460	it->index = *pos;
2461	it->max = sg_last_dev();
2462	if (it->index >= it->max)
2463		return NULL;
2464	return it;
2465}
2466
2467static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2468{
2469	struct sg_proc_deviter * it = s->private;
2470
2471	*pos = ++it->index;
2472	return (it->index < it->max) ? it : NULL;
2473}
2474
2475static void dev_seq_stop(struct seq_file *s, void *v)
2476{
2477	kfree(s->private);
2478}
2479
2480static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2481{
2482	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2483	Sg_device *sdp;
2484	struct scsi_device *scsidp;
2485	unsigned long iflags;
2486
2487	read_lock_irqsave(&sg_index_lock, iflags);
2488	sdp = it ? sg_lookup_dev(it->index) : NULL;
2489	if ((NULL == sdp) || (NULL == sdp->device) ||
2490	    (atomic_read(&sdp->detaching)))
2491		seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2492	else {
2493		scsidp = sdp->device;
2494		seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2495			      scsidp->host->host_no, scsidp->channel,
2496			      scsidp->id, scsidp->lun, (int) scsidp->type,
2497			      1,
2498			      (int) scsidp->queue_depth,
2499			      (int) scsi_device_busy(scsidp),
2500			      (int) scsi_device_online(scsidp));
2501	}
2502	read_unlock_irqrestore(&sg_index_lock, iflags);
2503	return 0;
2504}
2505
2506static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2507{
2508	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2509	Sg_device *sdp;
2510	struct scsi_device *scsidp;
2511	unsigned long iflags;
2512
2513	read_lock_irqsave(&sg_index_lock, iflags);
2514	sdp = it ? sg_lookup_dev(it->index) : NULL;
2515	scsidp = sdp ? sdp->device : NULL;
2516	if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2517		seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2518			   scsidp->vendor, scsidp->model, scsidp->rev);
2519	else
2520		seq_puts(s, "<no active device>\n");
2521	read_unlock_irqrestore(&sg_index_lock, iflags);
2522	return 0;
2523}
2524
2525/* must be called while holding sg_index_lock */
2526static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2527{
2528	int k, new_interface, blen, usg;
2529	Sg_request *srp;
2530	Sg_fd *fp;
2531	const sg_io_hdr_t *hp;
2532	const char * cp;
2533	unsigned int ms;
2534
2535	k = 0;
2536	list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2537		k++;
2538		read_lock(&fp->rq_list_lock); /* irqs already disabled */
2539		seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2540			   "(res)sgat=%d low_dma=%d\n", k,
2541			   jiffies_to_msecs(fp->timeout),
2542			   fp->reserve.bufflen,
2543			   (int) fp->reserve.k_use_sg, 0);
2544		seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2545			   (int) fp->cmd_q, (int) fp->force_packid,
2546			   (int) fp->keep_orphan);
2547		list_for_each_entry(srp, &fp->rq_list, entry) {
2548			hp = &srp->header;
2549			new_interface = (hp->interface_id == '\0') ? 0 : 1;
2550			if (srp->res_used) {
2551				if (new_interface &&
2552				    (SG_FLAG_MMAP_IO & hp->flags))
2553					cp = "     mmap>> ";
2554				else
2555					cp = "     rb>> ";
2556			} else {
2557				if (SG_INFO_DIRECT_IO_MASK & hp->info)
2558					cp = "     dio>> ";
2559				else
2560					cp = "     ";
2561			}
2562			seq_puts(s, cp);
2563			blen = srp->data.bufflen;
2564			usg = srp->data.k_use_sg;
2565			seq_puts(s, srp->done ?
2566				 ((1 == srp->done) ?  "rcv:" : "fin:")
2567				  : "act:");
2568			seq_printf(s, " id=%d blen=%d",
2569				   srp->header.pack_id, blen);
2570			if (srp->done)
2571				seq_printf(s, " dur=%d", hp->duration);
2572			else {
2573				ms = jiffies_to_msecs(jiffies);
2574				seq_printf(s, " t_o/elap=%d/%d",
2575					(new_interface ? hp->timeout :
2576						  jiffies_to_msecs(fp->timeout)),
2577					(ms > hp->duration ? ms - hp->duration : 0));
2578			}
2579			seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2580				   (int) srp->data.cmd_opcode);
2581		}
2582		if (list_empty(&fp->rq_list))
2583			seq_puts(s, "     No requests active\n");
2584		read_unlock(&fp->rq_list_lock);
2585	}
2586}
2587
2588static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2589{
2590	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2591	Sg_device *sdp;
2592	unsigned long iflags;
2593
2594	if (it && (0 == it->index))
2595		seq_printf(s, "max_active_device=%d  def_reserved_size=%d\n",
2596			   (int)it->max, sg_big_buff);
2597
2598	read_lock_irqsave(&sg_index_lock, iflags);
2599	sdp = it ? sg_lookup_dev(it->index) : NULL;
2600	if (NULL == sdp)
2601		goto skip;
2602	read_lock(&sdp->sfd_lock);
2603	if (!list_empty(&sdp->sfds)) {
2604		seq_printf(s, " >>> device=%s ", sdp->name);
2605		if (atomic_read(&sdp->detaching))
2606			seq_puts(s, "detaching pending close ");
2607		else if (sdp->device) {
2608			struct scsi_device *scsidp = sdp->device;
2609
2610			seq_printf(s, "%d:%d:%d:%llu   em=%d",
2611				   scsidp->host->host_no,
2612				   scsidp->channel, scsidp->id,
2613				   scsidp->lun,
2614				   scsidp->host->hostt->emulated);
2615		}
2616		seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2617			   sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2618		sg_proc_debug_helper(s, sdp);
2619	}
2620	read_unlock(&sdp->sfd_lock);
2621skip:
2622	read_unlock_irqrestore(&sg_index_lock, iflags);
2623	return 0;
2624}
2625
2626#endif				/* CONFIG_SCSI_PROC_FS */
2627
2628module_init(init_sg);
2629module_exit(exit_sg);