sg.c

   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	struct scsi_device *device;
 289	Sg_device *sdp;
 290	Sg_fd *sfp;
 291	int retval;
 292
 293	nonseekable_open(inode, filp);
 294	if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
 295		return -EPERM; /* Can't lock it with read only access */
 296	sdp = sg_get_dev(dev);
 297	if (IS_ERR(sdp))
 298		return PTR_ERR(sdp);
 299
 300	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 301				      "sg_open: flags=0x%x\n", flags));
 302
 303	/* This driver's module count bumped by fops_get in <linux/fs.h> */
 304	/* Prevent the device driver from vanishing while we sleep */
 305	device = sdp->device;
 306	retval = scsi_device_get(device);
 307	if (retval)
 308		goto sg_put;
 309
 310	/* scsi_block_when_processing_errors() may block so bypass
 311	 * check if O_NONBLOCK. Permits SCSI commands to be issued
 312	 * during error recovery. Tread carefully. */
 313	if (!((flags & O_NONBLOCK) ||
 314	      scsi_block_when_processing_errors(device))) {
 315		retval = -ENXIO;
 316		/* we are in error recovery for this device */
 317		goto sdp_put;
 318	}
 319
 320	mutex_lock(&sdp->open_rel_lock);
 321	if (flags & O_NONBLOCK) {
 322		if (flags & O_EXCL) {
 323			if (sdp->open_cnt > 0) {
 324				retval = -EBUSY;
 325				goto error_mutex_locked;
 326			}
 327		} else {
 328			if (sdp->exclude) {
 329				retval = -EBUSY;
 330				goto error_mutex_locked;
 331			}
 332		}
 333	} else {
 334		retval = open_wait(sdp, flags);
 335		if (retval) /* -ERESTARTSYS or -ENODEV */
 336			goto error_mutex_locked;
 337	}
 338
 339	/* N.B. at this point we are holding the open_rel_lock */
 340	if (flags & O_EXCL)
 341		sdp->exclude = true;
 342
 343	if (sdp->open_cnt < 1) {  /* no existing opens */
 344		sdp->sgdebug = 0;
 345		q = device->request_queue;
 346		sdp->sg_tablesize = queue_max_segments(q);
 347	}
 348	sfp = sg_add_sfp(sdp);
 349	if (IS_ERR(sfp)) {
 350		retval = PTR_ERR(sfp);
 351		goto out_undo;
 352	}
 353
 354	filp->private_data = sfp;
 355	sdp->open_cnt++;
 356	mutex_unlock(&sdp->open_rel_lock);
 357
 358	retval = 0;
 359sg_put:
 360	kref_put(&sdp->d_ref, sg_device_destroy);
 361	return retval;
 362
 363out_undo:
 364	if (flags & O_EXCL) {
 365		sdp->exclude = false;   /* undo if error */
 366		wake_up_interruptible(&sdp->open_wait);
 367	}
 368error_mutex_locked:
 369	mutex_unlock(&sdp->open_rel_lock);
 370sdp_put:
 371	kref_put(&sdp->d_ref, sg_device_destroy);
 372	scsi_device_put(device);
 373	return retval;
 374}
 375
 376/* Release resources associated with a successful sg_open()
 377 * Returns 0 on success, else a negated errno value */
 378static int
 379sg_release(struct inode *inode, struct file *filp)
 380{
 381	Sg_device *sdp;
 382	Sg_fd *sfp;
 383
 384	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 385		return -ENXIO;
 386	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
 387
 388	mutex_lock(&sdp->open_rel_lock);
 389	sdp->open_cnt--;
 390
 391	/* possibly many open()s waiting on exlude clearing, start many;
 392	 * only open(O_EXCL)s wait on 0==open_cnt so only start one */
 393	if (sdp->exclude) {
 394		sdp->exclude = false;
 395		wake_up_interruptible_all(&sdp->open_wait);
 396	} else if (0 == sdp->open_cnt) {
 397		wake_up_interruptible(&sdp->open_wait);
 398	}
 399	mutex_unlock(&sdp->open_rel_lock);
 400	kref_put(&sfp->f_ref, sg_remove_sfp);
 401	return 0;
 402}
 403
 404static int get_sg_io_pack_id(int *pack_id, void __user *buf, size_t count)
 405{
 406	struct sg_header __user *old_hdr = buf;
 407	int reply_len;
 408
 409	if (count >= SZ_SG_HEADER) {
 410		/* negative reply_len means v3 format, otherwise v1/v2 */
 411		if (get_user(reply_len, &old_hdr->reply_len))
 412			return -EFAULT;
 413
 414		if (reply_len >= 0)
 415			return get_user(*pack_id, &old_hdr->pack_id);
 416
 417		if (in_compat_syscall() &&
 418		    count >= sizeof(struct compat_sg_io_hdr)) {
 419			struct compat_sg_io_hdr __user *hp = buf;
 420
 421			return get_user(*pack_id, &hp->pack_id);
 422		}
 423
 424		if (count >= sizeof(struct sg_io_hdr)) {
 425			struct sg_io_hdr __user *hp = buf;
 426
 427			return get_user(*pack_id, &hp->pack_id);
 428		}
 429	}
 430
 431	/* no valid header was passed, so ignore the pack_id */
 432	*pack_id = -1;
 433	return 0;
 434}
 435
 436static ssize_t
 437sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 438{
 439	Sg_device *sdp;
 440	Sg_fd *sfp;
 441	Sg_request *srp;
 442	int req_pack_id = -1;
 443	bool busy;
 444	sg_io_hdr_t *hp;
 445	struct sg_header *old_hdr;
 446	int retval;
 447
 448	/*
 449	 * This could cause a response to be stranded. Close the associated
 450	 * file descriptor to free up any resources being held.
 451	 */
 452	retval = sg_check_file_access(filp, __func__);
 453	if (retval)
 454		return retval;
 455
 456	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 457		return -ENXIO;
 458	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 459				      "sg_read: count=%d\n", (int) count));
 460
 461	if (sfp->force_packid)
 462		retval = get_sg_io_pack_id(&req_pack_id, buf, count);
 463	if (retval)
 464		return retval;
 465
 466	srp = sg_get_rq_mark(sfp, req_pack_id, &busy);
 467	if (!srp) {		/* now wait on packet to arrive */
 468		if (filp->f_flags & O_NONBLOCK)
 469			return -EAGAIN;
 470		retval = wait_event_interruptible(sfp->read_wait,
 471			((srp = sg_get_rq_mark(sfp, req_pack_id, &busy)) ||
 472			(!busy && atomic_read(&sdp->detaching))));
 473		if (!srp)
 474			/* signal or detaching */
 475			return retval ? retval : -ENODEV;
 476	}
 477	if (srp->header.interface_id != '\0')
 478		return sg_new_read(sfp, buf, count, srp);
 479
 480	hp = &srp->header;
 481	old_hdr = kzalloc(SZ_SG_HEADER, GFP_KERNEL);
 482	if (!old_hdr)
 483		return -ENOMEM;
 484
 485	old_hdr->reply_len = (int) hp->timeout;
 486	old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 487	old_hdr->pack_id = hp->pack_id;
 488	old_hdr->twelve_byte =
 489	    ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 490	old_hdr->target_status = hp->masked_status;
 491	old_hdr->host_status = hp->host_status;
 492	old_hdr->driver_status = hp->driver_status;
 493	if ((CHECK_CONDITION & hp->masked_status) ||
 494	    (srp->sense_b[0] & 0x70) == 0x70) {
 495		old_hdr->driver_status = DRIVER_SENSE;
 496		memcpy(old_hdr->sense_buffer, srp->sense_b,
 497		       sizeof (old_hdr->sense_buffer));
 498	}
 499	switch (hp->host_status) {
 500	/* This setup of 'result' is for backward compatibility and is best
 501	   ignored by the user who should use target, host + driver status */
 502	case DID_OK:
 503	case DID_PASSTHROUGH:
 504	case DID_SOFT_ERROR:
 505		old_hdr->result = 0;
 506		break;
 507	case DID_NO_CONNECT:
 508	case DID_BUS_BUSY:
 509	case DID_TIME_OUT:
 510		old_hdr->result = EBUSY;
 511		break;
 512	case DID_BAD_TARGET:
 513	case DID_ABORT:
 514	case DID_PARITY:
 515	case DID_RESET:
 516	case DID_BAD_INTR:
 517		old_hdr->result = EIO;
 518		break;
 519	case DID_ERROR:
 520		old_hdr->result = (srp->sense_b[0] == 0 && 
 521				  hp->masked_status == GOOD) ? 0 : EIO;
 522		break;
 523	default:
 524		old_hdr->result = EIO;
 525		break;
 526	}
 527
 528	/* Now copy the result back to the user buffer.  */
 529	if (count >= SZ_SG_HEADER) {
 530		if (copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 531			retval = -EFAULT;
 532			goto free_old_hdr;
 533		}
 534		buf += SZ_SG_HEADER;
 535		if (count > old_hdr->reply_len)
 536			count = old_hdr->reply_len;
 537		if (count > SZ_SG_HEADER) {
 538			if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 539				retval = -EFAULT;
 540				goto free_old_hdr;
 541			}
 542		}
 543	} else
 544		count = (old_hdr->result == 0) ? 0 : -EIO;
 545	sg_finish_rem_req(srp);
 546	sg_remove_request(sfp, srp);
 547	retval = count;
 548free_old_hdr:
 549	kfree(old_hdr);
 550	return retval;
 551}
 552
 553static ssize_t
 554sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 555{
 556	sg_io_hdr_t *hp = &srp->header;
 557	int err = 0, err2;
 558	int len;
 559
 560	if (in_compat_syscall()) {
 561		if (count < sizeof(struct compat_sg_io_hdr)) {
 562			err = -EINVAL;
 563			goto err_out;
 564		}
 565	} else if (count < SZ_SG_IO_HDR) {
 566		err = -EINVAL;
 567		goto err_out;
 568	}
 569	hp->sb_len_wr = 0;
 570	if ((hp->mx_sb_len > 0) && hp->sbp) {
 571		if ((CHECK_CONDITION & hp->masked_status) ||
 572		    (srp->sense_b[0] & 0x70) == 0x70) {
 573			int sb_len = SCSI_SENSE_BUFFERSIZE;
 574			sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 575			len = 8 + (int) srp->sense_b[7];	/* Additional sense length field */
 576			len = (len > sb_len) ? sb_len : len;
 577			if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 578				err = -EFAULT;
 579				goto err_out;
 580			}
 581			hp->driver_status = DRIVER_SENSE;
 582			hp->sb_len_wr = len;
 583		}
 584	}
 585	if (hp->masked_status || hp->host_status || hp->driver_status)
 586		hp->info |= SG_INFO_CHECK;
 587	err = put_sg_io_hdr(hp, buf);
 588err_out:
 589	err2 = sg_finish_rem_req(srp);
 590	sg_remove_request(sfp, srp);
 591	return err ? : err2 ? : count;
 592}
 593
 594static ssize_t
 595sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 596{
 597	int mxsize, cmd_size, k;
 598	int input_size, blocking;
 599	unsigned char opcode;
 600	Sg_device *sdp;
 601	Sg_fd *sfp;
 602	Sg_request *srp;
 603	struct sg_header old_hdr;
 604	sg_io_hdr_t *hp;
 605	unsigned char cmnd[SG_MAX_CDB_SIZE];
 606	int retval;
 607
 608	retval = sg_check_file_access(filp, __func__);
 609	if (retval)
 610		return retval;
 611
 612	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 613		return -ENXIO;
 614	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 615				      "sg_write: count=%d\n", (int) count));
 616	if (atomic_read(&sdp->detaching))
 617		return -ENODEV;
 618	if (!((filp->f_flags & O_NONBLOCK) ||
 619	      scsi_block_when_processing_errors(sdp->device)))
 620		return -ENXIO;
 621
 622	if (count < SZ_SG_HEADER)
 623		return -EIO;
 624	if (copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 625		return -EFAULT;
 626	blocking = !(filp->f_flags & O_NONBLOCK);
 627	if (old_hdr.reply_len < 0)
 628		return sg_new_write(sfp, filp, buf, count,
 629				    blocking, 0, 0, NULL);
 630	if (count < (SZ_SG_HEADER + 6))
 631		return -EIO;	/* The minimum scsi command length is 6 bytes. */
 632
 633	buf += SZ_SG_HEADER;
 634	if (get_user(opcode, buf))
 635		return -EFAULT;
 636
 637	if (!(srp = sg_add_request(sfp))) {
 638		SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
 639					      "sg_write: queue full\n"));
 640		return -EDOM;
 641	}
 642	mutex_lock(&sfp->f_mutex);
 643	if (sfp->next_cmd_len > 0) {
 644		cmd_size = sfp->next_cmd_len;
 645		sfp->next_cmd_len = 0;	/* reset so only this write() effected */
 646	} else {
 647		cmd_size = COMMAND_SIZE(opcode);	/* based on SCSI command group */
 648		if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 649			cmd_size = 12;
 650	}
 651	mutex_unlock(&sfp->f_mutex);
 652	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
 653		"sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 654/* Determine buffer size.  */
 655	input_size = count - cmd_size;
 656	mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 657	mxsize -= SZ_SG_HEADER;
 658	input_size -= SZ_SG_HEADER;
 659	if (input_size < 0) {
 660		sg_remove_request(sfp, srp);
 661		return -EIO;	/* User did not pass enough bytes for this command. */
 662	}
 663	hp = &srp->header;
 664	hp->interface_id = '\0';	/* indicator of old interface tunnelled */
 665	hp->cmd_len = (unsigned char) cmd_size;
 666	hp->iovec_count = 0;
 667	hp->mx_sb_len = 0;
 668	if (input_size > 0)
 669		hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 670		    SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 671	else
 672		hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 673	hp->dxfer_len = mxsize;
 674	if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
 675	    (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
 676		hp->dxferp = (char __user *)buf + cmd_size;
 677	else
 678		hp->dxferp = NULL;
 679	hp->sbp = NULL;
 680	hp->timeout = old_hdr.reply_len;	/* structure abuse ... */
 681	hp->flags = input_size;	/* structure abuse ... */
 682	hp->pack_id = old_hdr.pack_id;
 683	hp->usr_ptr = NULL;
 684	if (copy_from_user(cmnd, buf, cmd_size)) {
 685		sg_remove_request(sfp, srp);
 686		return -EFAULT;
 687	}
 688	/*
 689	 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 690	 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 691	 * is a non-zero input_size, so emit a warning.
 692	 */
 693	if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 694		printk_ratelimited(KERN_WARNING
 695				   "sg_write: data in/out %d/%d bytes "
 696				   "for SCSI command 0x%x-- guessing "
 697				   "data in;\n   program %s not setting "
 698				   "count and/or reply_len properly\n",
 699				   old_hdr.reply_len - (int)SZ_SG_HEADER,
 700				   input_size, (unsigned int) cmnd[0],
 701				   current->comm);
 702	}
 703	k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 704	return (k < 0) ? k : count;
 705}
 706
 707static ssize_t
 708sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 709		 size_t count, int blocking, int read_only, int sg_io_owned,
 710		 Sg_request **o_srp)
 711{
 712	int k;
 713	Sg_request *srp;
 714	sg_io_hdr_t *hp;
 715	unsigned char cmnd[SG_MAX_CDB_SIZE];
 716	int timeout;
 717	unsigned long ul_timeout;
 718
 719	if (count < SZ_SG_IO_HDR)
 720		return -EINVAL;
 721
 722	sfp->cmd_q = 1;	/* when sg_io_hdr seen, set command queuing on */
 723	if (!(srp = sg_add_request(sfp))) {
 724		SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 725					      "sg_new_write: queue full\n"));
 726		return -EDOM;
 727	}
 728	srp->sg_io_owned = sg_io_owned;
 729	hp = &srp->header;
 730	if (get_sg_io_hdr(hp, buf)) {
 731		sg_remove_request(sfp, srp);
 732		return -EFAULT;
 733	}
 734	hp->duration = jiffies_to_msecs(jiffies);
 735
 736	if (hp->interface_id != 'S') {
 737		sg_remove_request(sfp, srp);
 738		return -ENOSYS;
 739	}
 740	if (hp->flags & SG_FLAG_MMAP_IO) {
 741		if (hp->dxfer_len > sfp->reserve.bufflen) {
 742			sg_remove_request(sfp, srp);
 743			return -ENOMEM;	/* MMAP_IO size must fit in reserve buffer */
 744		}
 745		if (hp->flags & SG_FLAG_DIRECT_IO) {
 746			sg_remove_request(sfp, srp);
 747			return -EINVAL;	/* either MMAP_IO or DIRECT_IO (not both) */
 748		}
 749		if (sfp->res_in_use) {
 750			sg_remove_request(sfp, srp);
 751			return -EBUSY;	/* reserve buffer already being used */
 752		}
 753	}
 754	ul_timeout = msecs_to_jiffies(srp->header.timeout);
 755	timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 756	if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 757		sg_remove_request(sfp, srp);
 758		return -EMSGSIZE;
 759	}
 760	if (copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 761		sg_remove_request(sfp, srp);
 762		return -EFAULT;
 763	}
 764	if (read_only && sg_allow_access(file, cmnd)) {
 765		sg_remove_request(sfp, srp);
 766		return -EPERM;
 767	}
 768	k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 769	if (k < 0)
 770		return k;
 771	if (o_srp)
 772		*o_srp = srp;
 773	return count;
 774}
 775
 776static int
 777sg_common_write(Sg_fd * sfp, Sg_request * srp,
 778		unsigned char *cmnd, int timeout, int blocking)
 779{
 780	int k, at_head;
 781	Sg_device *sdp = sfp->parentdp;
 782	sg_io_hdr_t *hp = &srp->header;
 783
 784	srp->data.cmd_opcode = cmnd[0];	/* hold opcode of command */
 785	hp->status = 0;
 786	hp->masked_status = 0;
 787	hp->msg_status = 0;
 788	hp->info = 0;
 789	hp->host_status = 0;
 790	hp->driver_status = 0;
 791	hp->resid = 0;
 792	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
 793			"sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 794			(int) cmnd[0], (int) hp->cmd_len));
 795
 796	if (hp->dxfer_len >= SZ_256M) {
 797		sg_remove_request(sfp, srp);
 798		return -EINVAL;
 799	}
 800
 801	k = sg_start_req(srp, cmnd);
 802	if (k) {
 803		SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 804			"sg_common_write: start_req err=%d\n", k));
 805		sg_finish_rem_req(srp);
 806		sg_remove_request(sfp, srp);
 807		return k;	/* probably out of space --> ENOMEM */
 808	}
 809	if (atomic_read(&sdp->detaching)) {
 810		if (srp->bio) {
 811			blk_mq_free_request(srp->rq);
 812			srp->rq = NULL;
 813		}
 814
 815		sg_finish_rem_req(srp);
 816		sg_remove_request(sfp, srp);
 817		return -ENODEV;
 818	}
 819
 820	if (hp->interface_id != '\0' &&	/* v3 (or later) interface */
 821	    (SG_FLAG_Q_AT_TAIL & hp->flags))
 822		at_head = 0;
 823	else
 824		at_head = 1;
 825
 826	srp->rq->timeout = timeout;
 827	kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
 828	srp->rq->end_io = sg_rq_end_io;
 829	blk_execute_rq_nowait(srp->rq, at_head);
 830	return 0;
 831}
 832
 833static int srp_done(Sg_fd *sfp, Sg_request *srp)
 834{
 835	unsigned long flags;
 836	int ret;
 837
 838	read_lock_irqsave(&sfp->rq_list_lock, flags);
 839	ret = srp->done;
 840	read_unlock_irqrestore(&sfp->rq_list_lock, flags);
 841	return ret;
 842}
 843
 844static int max_sectors_bytes(struct request_queue *q)
 845{
 846	unsigned int max_sectors = queue_max_sectors(q);
 847
 848	max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
 849
 850	return max_sectors << 9;
 851}
 852
 853static void
 854sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
 855{
 856	Sg_request *srp;
 857	int val;
 858	unsigned int ms;
 859
 860	val = 0;
 861	list_for_each_entry(srp, &sfp->rq_list, entry) {
 862		if (val >= SG_MAX_QUEUE)
 863			break;
 864		rinfo[val].req_state = srp->done + 1;
 865		rinfo[val].problem =
 866			srp->header.masked_status &
 867			srp->header.host_status &
 868			srp->header.driver_status;
 869		if (srp->done)
 870			rinfo[val].duration =
 871				srp->header.duration;
 872		else {
 873			ms = jiffies_to_msecs(jiffies);
 874			rinfo[val].duration =
 875				(ms > srp->header.duration) ?
 876				(ms - srp->header.duration) : 0;
 877		}
 878		rinfo[val].orphan = srp->orphan;
 879		rinfo[val].sg_io_owned = srp->sg_io_owned;
 880		rinfo[val].pack_id = srp->header.pack_id;
 881		rinfo[val].usr_ptr = srp->header.usr_ptr;
 882		val++;
 883	}
 884}
 885
 886#ifdef CONFIG_COMPAT
 887struct compat_sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
 888	char req_state;
 889	char orphan;
 890	char sg_io_owned;
 891	char problem;
 892	int pack_id;
 893	compat_uptr_t usr_ptr;
 894	unsigned int duration;
 895	int unused;
 896};
 897
 898static int put_compat_request_table(struct compat_sg_req_info __user *o,
 899				    struct sg_req_info *rinfo)
 900{
 901	int i;
 902	for (i = 0; i < SG_MAX_QUEUE; i++) {
 903		if (copy_to_user(o + i, rinfo + i, offsetof(sg_req_info_t, usr_ptr)) ||
 904		    put_user((uintptr_t)rinfo[i].usr_ptr, &o[i].usr_ptr) ||
 905		    put_user(rinfo[i].duration, &o[i].duration) ||
 906		    put_user(rinfo[i].unused, &o[i].unused))
 907			return -EFAULT;
 908	}
 909	return 0;
 910}
 911#endif
 912
 913static long
 914sg_ioctl_common(struct file *filp, Sg_device *sdp, Sg_fd *sfp,
 915		unsigned int cmd_in, void __user *p)
 916{
 917	int __user *ip = p;
 918	int result, val, read_only;
 919	Sg_request *srp;
 920	unsigned long iflags;
 921
 922	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 923				   "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
 924	read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 925
 926	switch (cmd_in) {
 927	case SG_IO:
 928		if (atomic_read(&sdp->detaching))
 929			return -ENODEV;
 930		if (!scsi_block_when_processing_errors(sdp->device))
 931			return -ENXIO;
 932		result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 933				 1, read_only, 1, &srp);
 934		if (result < 0)
 935			return result;
 936		result = wait_event_interruptible(sfp->read_wait,
 937			srp_done(sfp, srp));
 938		write_lock_irq(&sfp->rq_list_lock);
 939		if (srp->done) {
 940			srp->done = 2;
 941			write_unlock_irq(&sfp->rq_list_lock);
 942			result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 943			return (result < 0) ? result : 0;
 944		}
 945		srp->orphan = 1;
 946		write_unlock_irq(&sfp->rq_list_lock);
 947		return result;	/* -ERESTARTSYS because signal hit process */
 948	case SG_SET_TIMEOUT:
 949		result = get_user(val, ip);
 950		if (result)
 951			return result;
 952		if (val < 0)
 953			return -EIO;
 954		if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
 955			val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
 956				    INT_MAX);
 957		sfp->timeout_user = val;
 958		sfp->timeout = mult_frac(val, HZ, USER_HZ);
 959
 960		return 0;
 961	case SG_GET_TIMEOUT:	/* N.B. User receives timeout as return value */
 962				/* strange ..., for backward compatibility */
 963		return sfp->timeout_user;
 964	case SG_SET_FORCE_LOW_DMA:
 965		/*
 966		 * N.B. This ioctl never worked properly, but failed to
 967		 * return an error value. So returning '0' to keep compability
 968		 * with legacy applications.
 969		 */
 970		return 0;
 971	case SG_GET_LOW_DMA:
 972		return put_user(0, ip);
 973	case SG_GET_SCSI_ID:
 974		{
 975			sg_scsi_id_t v;
 976
 977			if (atomic_read(&sdp->detaching))
 978				return -ENODEV;
 979			memset(&v, 0, sizeof(v));
 980			v.host_no = sdp->device->host->host_no;
 981			v.channel = sdp->device->channel;
 982			v.scsi_id = sdp->device->id;
 983			v.lun = sdp->device->lun;
 984			v.scsi_type = sdp->device->type;
 985			v.h_cmd_per_lun = sdp->device->host->cmd_per_lun;
 986			v.d_queue_depth = sdp->device->queue_depth;
 987			if (copy_to_user(p, &v, sizeof(sg_scsi_id_t)))
 988				return -EFAULT;
 989			return 0;
 990		}
 991	case SG_SET_FORCE_PACK_ID:
 992		result = get_user(val, ip);
 993		if (result)
 994			return result;
 995		sfp->force_packid = val ? 1 : 0;
 996		return 0;
 997	case SG_GET_PACK_ID:
 998		read_lock_irqsave(&sfp->rq_list_lock, iflags);
 999		list_for_each_entry(srp, &sfp->rq_list, entry) {
1000			if ((1 == srp->done) && (!srp->sg_io_owned)) {
1001				read_unlock_irqrestore(&sfp->rq_list_lock,
1002						       iflags);
1003				return put_user(srp->header.pack_id, ip);
1004			}
1005		}
1006		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1007		return put_user(-1, ip);
1008	case SG_GET_NUM_WAITING:
1009		read_lock_irqsave(&sfp->rq_list_lock, iflags);
1010		val = 0;
1011		list_for_each_entry(srp, &sfp->rq_list, entry) {
1012			if ((1 == srp->done) && (!srp->sg_io_owned))
1013				++val;
1014		}
1015		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1016		return put_user(val, ip);
1017	case SG_GET_SG_TABLESIZE:
1018		return put_user(sdp->sg_tablesize, ip);
1019	case SG_SET_RESERVED_SIZE:
1020		result = get_user(val, ip);
1021		if (result)
1022			return result;
1023                if (val < 0)
1024                        return -EINVAL;
1025		val = min_t(int, val,
1026			    max_sectors_bytes(sdp->device->request_queue));
1027		mutex_lock(&sfp->f_mutex);
1028		if (val != sfp->reserve.bufflen) {
1029			if (sfp->mmap_called ||
1030			    sfp->res_in_use) {
1031				mutex_unlock(&sfp->f_mutex);
1032				return -EBUSY;
1033			}
1034
1035			sg_remove_scat(sfp, &sfp->reserve);
1036			sg_build_reserve(sfp, val);
1037		}
1038		mutex_unlock(&sfp->f_mutex);
1039		return 0;
1040	case SG_GET_RESERVED_SIZE:
1041		val = min_t(int, sfp->reserve.bufflen,
1042			    max_sectors_bytes(sdp->device->request_queue));
1043		return put_user(val, ip);
1044	case SG_SET_COMMAND_Q:
1045		result = get_user(val, ip);
1046		if (result)
1047			return result;
1048		sfp->cmd_q = val ? 1 : 0;
1049		return 0;
1050	case SG_GET_COMMAND_Q:
1051		return put_user((int) sfp->cmd_q, ip);
1052	case SG_SET_KEEP_ORPHAN:
1053		result = get_user(val, ip);
1054		if (result)
1055			return result;
1056		sfp->keep_orphan = val;
1057		return 0;
1058	case SG_GET_KEEP_ORPHAN:
1059		return put_user((int) sfp->keep_orphan, ip);
1060	case SG_NEXT_CMD_LEN:
1061		result = get_user(val, ip);
1062		if (result)
1063			return result;
1064		if (val > SG_MAX_CDB_SIZE)
1065			return -ENOMEM;
1066		sfp->next_cmd_len = (val > 0) ? val : 0;
1067		return 0;
1068	case SG_GET_VERSION_NUM:
1069		return put_user(sg_version_num, ip);
1070	case SG_GET_ACCESS_COUNT:
1071		/* faked - we don't have a real access count anymore */
1072		val = (sdp->device ? 1 : 0);
1073		return put_user(val, ip);
1074	case SG_GET_REQUEST_TABLE:
1075		{
1076			sg_req_info_t *rinfo;
1077
1078			rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
1079					GFP_KERNEL);
1080			if (!rinfo)
1081				return -ENOMEM;
1082			read_lock_irqsave(&sfp->rq_list_lock, iflags);
1083			sg_fill_request_table(sfp, rinfo);
1084			read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1085	#ifdef CONFIG_COMPAT
1086			if (in_compat_syscall())
1087				result = put_compat_request_table(p, rinfo);
1088			else
1089	#endif
1090				result = copy_to_user(p, rinfo,
1091						      SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1092			result = result ? -EFAULT : 0;
1093			kfree(rinfo);
1094			return result;
1095		}
1096	case SG_EMULATED_HOST:
1097		if (atomic_read(&sdp->detaching))
1098			return -ENODEV;
1099		return put_user(sdp->device->host->hostt->emulated, ip);
1100	case SCSI_IOCTL_SEND_COMMAND:
1101		if (atomic_read(&sdp->detaching))
1102			return -ENODEV;
1103		return scsi_ioctl(sdp->device, filp->f_mode & FMODE_WRITE,
1104				  cmd_in, p);
1105	case SG_SET_DEBUG:
1106		result = get_user(val, ip);
1107		if (result)
1108			return result;
1109		sdp->sgdebug = (char) val;
1110		return 0;
1111	case BLKSECTGET:
1112		return put_user(max_sectors_bytes(sdp->device->request_queue),
1113				ip);
1114	case BLKTRACESETUP:
1115		return blk_trace_setup(sdp->device->request_queue, sdp->name,
1116				       MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1117				       NULL, p);
1118	case BLKTRACESTART:
1119		return blk_trace_startstop(sdp->device->request_queue, 1);
1120	case BLKTRACESTOP:
1121		return blk_trace_startstop(sdp->device->request_queue, 0);
1122	case BLKTRACETEARDOWN:
1123		return blk_trace_remove(sdp->device->request_queue);
1124	case SCSI_IOCTL_GET_IDLUN:
1125	case SCSI_IOCTL_GET_BUS_NUMBER:
1126	case SCSI_IOCTL_PROBE_HOST:
1127	case SG_GET_TRANSFORM:
1128	case SG_SCSI_RESET:
1129		if (atomic_read(&sdp->detaching))
1130			return -ENODEV;
1131		break;
1132	default:
1133		if (read_only)
1134			return -EPERM;	/* don't know so take safe approach */
1135		break;
1136	}
1137
1138	result = scsi_ioctl_block_when_processing_errors(sdp->device,
1139			cmd_in, filp->f_flags & O_NDELAY);
1140	if (result)
1141		return result;
1142
1143	return -ENOIOCTLCMD;
1144}
1145
1146static long
1147sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1148{
1149	void __user *p = (void __user *)arg;
1150	Sg_device *sdp;
1151	Sg_fd *sfp;
1152	int ret;
1153
1154	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1155		return -ENXIO;
1156
1157	ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
1158	if (ret != -ENOIOCTLCMD)
1159		return ret;
1160	return scsi_ioctl(sdp->device, filp->f_mode & FMODE_WRITE, cmd_in, p);
1161}
1162
1163static __poll_t
1164sg_poll(struct file *filp, poll_table * wait)
1165{
1166	__poll_t res = 0;
1167	Sg_device *sdp;
1168	Sg_fd *sfp;
1169	Sg_request *srp;
1170	int count = 0;
1171	unsigned long iflags;
1172
1173	sfp = filp->private_data;
1174	if (!sfp)
1175		return EPOLLERR;
1176	sdp = sfp->parentdp;
1177	if (!sdp)
1178		return EPOLLERR;
1179	poll_wait(filp, &sfp->read_wait, wait);
1180	read_lock_irqsave(&sfp->rq_list_lock, iflags);
1181	list_for_each_entry(srp, &sfp->rq_list, entry) {
1182		/* if any read waiting, flag it */
1183		if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1184			res = EPOLLIN | EPOLLRDNORM;
1185		++count;
1186	}
1187	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1188
1189	if (atomic_read(&sdp->detaching))
1190		res |= EPOLLHUP;
1191	else if (!sfp->cmd_q) {
1192		if (0 == count)
1193			res |= EPOLLOUT | EPOLLWRNORM;
1194	} else if (count < SG_MAX_QUEUE)
1195		res |= EPOLLOUT | EPOLLWRNORM;
1196	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1197				      "sg_poll: res=0x%x\n", (__force u32) res));
1198	return res;
1199}
1200
1201static int
1202sg_fasync(int fd, struct file *filp, int mode)
1203{
1204	Sg_device *sdp;
1205	Sg_fd *sfp;
1206
1207	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1208		return -ENXIO;
1209	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1210				      "sg_fasync: mode=%d\n", mode));
1211
1212	return fasync_helper(fd, filp, mode, &sfp->async_qp);
1213}
1214
1215static vm_fault_t
1216sg_vma_fault(struct vm_fault *vmf)
1217{
1218	struct vm_area_struct *vma = vmf->vma;
1219	Sg_fd *sfp;
1220	unsigned long offset, len, sa;
1221	Sg_scatter_hold *rsv_schp;
1222	int k, length;
1223
1224	if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1225		return VM_FAULT_SIGBUS;
1226	rsv_schp = &sfp->reserve;
1227	offset = vmf->pgoff << PAGE_SHIFT;
1228	if (offset >= rsv_schp->bufflen)
1229		return VM_FAULT_SIGBUS;
1230	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1231				      "sg_vma_fault: offset=%lu, scatg=%d\n",
1232				      offset, rsv_schp->k_use_sg));
1233	sa = vma->vm_start;
1234	length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1235	for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1236		len = vma->vm_end - sa;
1237		len = (len < length) ? len : length;
1238		if (offset < len) {
1239			struct page *page = rsv_schp->pages[k] + (offset >> PAGE_SHIFT);
1240			get_page(page);	/* increment page count */
1241			vmf->page = page;
1242			return 0; /* success */
1243		}
1244		sa += len;
1245		offset -= len;
1246	}
1247
1248	return VM_FAULT_SIGBUS;
1249}
1250
1251static const struct vm_operations_struct sg_mmap_vm_ops = {
1252	.fault = sg_vma_fault,
1253};
1254
1255static int
1256sg_mmap(struct file *filp, struct vm_area_struct *vma)
1257{
1258	Sg_fd *sfp;
1259	unsigned long req_sz, len, sa;
1260	Sg_scatter_hold *rsv_schp;
1261	int k, length;
1262	int ret = 0;
1263
1264	if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1265		return -ENXIO;
1266	req_sz = vma->vm_end - vma->vm_start;
1267	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1268				      "sg_mmap starting, vm_start=%p, len=%d\n",
1269				      (void *) vma->vm_start, (int) req_sz));
1270	if (vma->vm_pgoff)
1271		return -EINVAL;	/* want no offset */
1272	rsv_schp = &sfp->reserve;
1273	mutex_lock(&sfp->f_mutex);
1274	if (req_sz > rsv_schp->bufflen) {
1275		ret = -ENOMEM;	/* cannot map more than reserved buffer */
1276		goto out;
1277	}
1278
1279	sa = vma->vm_start;
1280	length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1281	for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1282		len = vma->vm_end - sa;
1283		len = (len < length) ? len : length;
1284		sa += len;
1285	}
1286
1287	sfp->mmap_called = 1;
1288	vm_flags_set(vma, VM_IO | VM_DONTEXPAND | VM_DONTDUMP);
1289	vma->vm_private_data = sfp;
1290	vma->vm_ops = &sg_mmap_vm_ops;
1291out:
1292	mutex_unlock(&sfp->f_mutex);
1293	return ret;
1294}
1295
1296static void
1297sg_rq_end_io_usercontext(struct work_struct *work)
1298{
1299	struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1300	struct sg_fd *sfp = srp->parentfp;
1301
1302	sg_finish_rem_req(srp);
1303	sg_remove_request(sfp, srp);
1304	kref_put(&sfp->f_ref, sg_remove_sfp);
1305}
1306
1307/*
1308 * This function is a "bottom half" handler that is called by the mid
1309 * level when a command is completed (or has failed).
1310 */
1311static enum rq_end_io_ret
1312sg_rq_end_io(struct request *rq, blk_status_t status)
1313{
1314	struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
1315	struct sg_request *srp = rq->end_io_data;
1316	Sg_device *sdp;
1317	Sg_fd *sfp;
1318	unsigned long iflags;
1319	unsigned int ms;
1320	char *sense;
1321	int result, resid, done = 1;
1322
1323	if (WARN_ON(srp->done != 0))
1324		return RQ_END_IO_NONE;
1325
1326	sfp = srp->parentfp;
1327	if (WARN_ON(sfp == NULL))
1328		return RQ_END_IO_NONE;
1329
1330	sdp = sfp->parentdp;
1331	if (unlikely(atomic_read(&sdp->detaching)))
1332		pr_info("%s: device detaching\n", __func__);
1333
1334	sense = scmd->sense_buffer;
1335	result = scmd->result;
1336	resid = scmd->resid_len;
1337
1338	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1339				      "sg_cmd_done: pack_id=%d, res=0x%x\n",
1340				      srp->header.pack_id, result));
1341	srp->header.resid = resid;
1342	if (0 != result) {
1343		struct scsi_sense_hdr sshdr;
1344
1345		srp->header.status = 0xff & result;
1346		srp->header.masked_status = sg_status_byte(result);
1347		srp->header.msg_status = COMMAND_COMPLETE;
1348		srp->header.host_status = host_byte(result);
1349		srp->header.driver_status = driver_byte(result);
1350		if ((sdp->sgdebug > 0) &&
1351		    ((CHECK_CONDITION == srp->header.masked_status) ||
1352		     (COMMAND_TERMINATED == srp->header.masked_status)))
1353			__scsi_print_sense(sdp->device, __func__, sense,
1354					   SCSI_SENSE_BUFFERSIZE);
1355
1356		/* Following if statement is a patch supplied by Eric Youngdale */
1357		if (driver_byte(result) != 0
1358		    && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1359		    && !scsi_sense_is_deferred(&sshdr)
1360		    && sshdr.sense_key == UNIT_ATTENTION
1361		    && sdp->device->removable) {
1362			/* Detected possible disc change. Set the bit - this */
1363			/* may be used if there are filesystems using this device */
1364			sdp->device->changed = 1;
1365		}
1366	}
1367
1368	if (scmd->sense_len)
1369		memcpy(srp->sense_b, scmd->sense_buffer, SCSI_SENSE_BUFFERSIZE);
1370
1371	/* Rely on write phase to clean out srp status values, so no "else" */
1372
1373	/*
1374	 * Free the request as soon as it is complete so that its resources
1375	 * can be reused without waiting for userspace to read() the
1376	 * result.  But keep the associated bio (if any) around until
1377	 * blk_rq_unmap_user() can be called from user context.
1378	 */
1379	srp->rq = NULL;
1380	blk_mq_free_request(rq);
1381
1382	write_lock_irqsave(&sfp->rq_list_lock, iflags);
1383	if (unlikely(srp->orphan)) {
1384		if (sfp->keep_orphan)
1385			srp->sg_io_owned = 0;
1386		else
1387			done = 0;
1388	}
1389	srp->done = done;
1390	ms = jiffies_to_msecs(jiffies);
1391	srp->header.duration = (ms > srp->header.duration) ?
1392				(ms - srp->header.duration) : 0;
1393	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1394
1395	if (likely(done)) {
1396		/* Now wake up any sg_read() that is waiting for this
1397		 * packet.
1398		 */
1399		wake_up_interruptible(&sfp->read_wait);
1400		kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1401		kref_put(&sfp->f_ref, sg_remove_sfp);
1402	} else {
1403		INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1404		schedule_work(&srp->ew.work);
1405	}
1406	return RQ_END_IO_NONE;
1407}
1408
1409static const struct file_operations sg_fops = {
1410	.owner = THIS_MODULE,
1411	.read = sg_read,
1412	.write = sg_write,
1413	.poll = sg_poll,
1414	.unlocked_ioctl = sg_ioctl,
1415	.compat_ioctl = compat_ptr_ioctl,
1416	.open = sg_open,
1417	.mmap = sg_mmap,
1418	.release = sg_release,
1419	.fasync = sg_fasync,
1420};
1421
1422static const struct class sg_sysfs_class = {
1423	.name = "scsi_generic"
1424};
1425
1426static int sg_sysfs_valid = 0;
1427
1428static Sg_device *
1429sg_alloc(struct scsi_device *scsidp)
1430{
1431	struct request_queue *q = scsidp->request_queue;
1432	Sg_device *sdp;
1433	unsigned long iflags;
1434	int error;
1435	u32 k;
1436
1437	sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1438	if (!sdp) {
1439		sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1440			    "failure\n", __func__);
1441		return ERR_PTR(-ENOMEM);
1442	}
1443
1444	idr_preload(GFP_KERNEL);
1445	write_lock_irqsave(&sg_index_lock, iflags);
1446
1447	error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1448	if (error < 0) {
1449		if (error == -ENOSPC) {
1450			sdev_printk(KERN_WARNING, scsidp,
1451				    "Unable to attach sg device type=%d, minor number exceeds %d\n",
1452				    scsidp->type, SG_MAX_DEVS - 1);
1453			error = -ENODEV;
1454		} else {
1455			sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1456				    "allocation Sg_device failure: %d\n",
1457				    __func__, error);
1458		}
1459		goto out_unlock;
1460	}
1461	k = error;
1462
1463	SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1464					"sg_alloc: dev=%d \n", k));
1465	sprintf(sdp->name, "sg%d", k);
1466	sdp->device = scsidp;
1467	mutex_init(&sdp->open_rel_lock);
1468	INIT_LIST_HEAD(&sdp->sfds);
1469	init_waitqueue_head(&sdp->open_wait);
1470	atomic_set(&sdp->detaching, 0);
1471	rwlock_init(&sdp->sfd_lock);
1472	sdp->sg_tablesize = queue_max_segments(q);
1473	sdp->index = k;
1474	kref_init(&sdp->d_ref);
1475	error = 0;
1476
1477out_unlock:
1478	write_unlock_irqrestore(&sg_index_lock, iflags);
1479	idr_preload_end();
1480
1481	if (error) {
1482		kfree(sdp);
1483		return ERR_PTR(error);
1484	}
1485	return sdp;
1486}
1487
1488static int
1489sg_add_device(struct device *cl_dev)
1490{
1491	struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1492	Sg_device *sdp = NULL;
1493	struct cdev * cdev = NULL;
1494	int error;
1495	unsigned long iflags;
1496
1497	if (!blk_get_queue(scsidp->request_queue)) {
1498		pr_warn("%s: get scsi_device queue failed\n", __func__);
1499		return -ENODEV;
1500	}
1501
1502	error = -ENOMEM;
1503	cdev = cdev_alloc();
1504	if (!cdev) {
1505		pr_warn("%s: cdev_alloc failed\n", __func__);
1506		goto out;
1507	}
1508	cdev->owner = THIS_MODULE;
1509	cdev->ops = &sg_fops;
1510
1511	sdp = sg_alloc(scsidp);
1512	if (IS_ERR(sdp)) {
1513		pr_warn("%s: sg_alloc failed\n", __func__);
1514		error = PTR_ERR(sdp);
1515		goto out;
1516	}
1517
1518	error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1519	if (error)
1520		goto cdev_add_err;
1521
1522	sdp->cdev = cdev;
1523	if (sg_sysfs_valid) {
1524		struct device *sg_class_member;
1525
1526		sg_class_member = device_create(&sg_sysfs_class, cl_dev->parent,
1527						MKDEV(SCSI_GENERIC_MAJOR,
1528						      sdp->index),
1529						sdp, "%s", sdp->name);
1530		if (IS_ERR(sg_class_member)) {
1531			pr_err("%s: device_create failed\n", __func__);
1532			error = PTR_ERR(sg_class_member);
1533			goto cdev_add_err;
1534		}
1535		error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1536					  &sg_class_member->kobj, "generic");
1537		if (error)
1538			pr_err("%s: unable to make symlink 'generic' back "
1539			       "to sg%d\n", __func__, sdp->index);
1540	} else
1541		pr_warn("%s: sg_sys Invalid\n", __func__);
1542
1543	sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1544		    "type %d\n", sdp->index, scsidp->type);
1545
1546	dev_set_drvdata(cl_dev, sdp);
1547
1548	return 0;
1549
1550cdev_add_err:
1551	write_lock_irqsave(&sg_index_lock, iflags);
1552	idr_remove(&sg_index_idr, sdp->index);
1553	write_unlock_irqrestore(&sg_index_lock, iflags);
1554	kfree(sdp);
1555
1556out:
1557	if (cdev)
1558		cdev_del(cdev);
1559	blk_put_queue(scsidp->request_queue);
1560	return error;
1561}
1562
1563static void
1564sg_device_destroy(struct kref *kref)
1565{
1566	struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1567	struct request_queue *q = sdp->device->request_queue;
1568	unsigned long flags;
1569
1570	/* CAUTION!  Note that the device can still be found via idr_find()
1571	 * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1572	 * any other cleanup.
1573	 */
1574
1575	blk_trace_remove(q);
1576	blk_put_queue(q);
1577
1578	write_lock_irqsave(&sg_index_lock, flags);
1579	idr_remove(&sg_index_idr, sdp->index);
1580	write_unlock_irqrestore(&sg_index_lock, flags);
1581
1582	SCSI_LOG_TIMEOUT(3,
1583		sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1584
1585	kfree(sdp);
1586}
1587
1588static void
1589sg_remove_device(struct device *cl_dev)
1590{
1591	struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1592	Sg_device *sdp = dev_get_drvdata(cl_dev);
1593	unsigned long iflags;
1594	Sg_fd *sfp;
1595	int val;
1596
1597	if (!sdp)
1598		return;
1599	/* want sdp->detaching non-zero as soon as possible */
1600	val = atomic_inc_return(&sdp->detaching);
1601	if (val > 1)
1602		return; /* only want to do following once per device */
1603
1604	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1605				      "%s\n", __func__));
1606
1607	read_lock_irqsave(&sdp->sfd_lock, iflags);
1608	list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1609		wake_up_interruptible_all(&sfp->read_wait);
1610		kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1611	}
1612	wake_up_interruptible_all(&sdp->open_wait);
1613	read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1614
1615	sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1616	device_destroy(&sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1617	cdev_del(sdp->cdev);
1618	sdp->cdev = NULL;
1619
1620	kref_put(&sdp->d_ref, sg_device_destroy);
1621}
1622
1623module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1624module_param_named(def_reserved_size, def_reserved_size, int,
1625		   S_IRUGO | S_IWUSR);
1626module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1627
1628MODULE_AUTHOR("Douglas Gilbert");
1629MODULE_DESCRIPTION("SCSI generic (sg) driver");
1630MODULE_LICENSE("GPL");
1631MODULE_VERSION(SG_VERSION_STR);
1632MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1633
1634MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1635                "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1636MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1637MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1638
1639#ifdef CONFIG_SYSCTL
1640#include <linux/sysctl.h>
1641
1642static const struct ctl_table sg_sysctls[] = {
1643	{
1644		.procname	= "sg-big-buff",
1645		.data		= &sg_big_buff,
1646		.maxlen		= sizeof(int),
1647		.mode		= 0444,
1648		.proc_handler	= proc_dointvec,
1649	},
1650};
1651
1652static struct ctl_table_header *hdr;
1653static void register_sg_sysctls(void)
1654{
1655	if (!hdr)
1656		hdr = register_sysctl("kernel", sg_sysctls);
1657}
1658
1659static void unregister_sg_sysctls(void)
1660{
1661	unregister_sysctl_table(hdr);
1662}
1663#else
1664#define register_sg_sysctls() do { } while (0)
1665#define unregister_sg_sysctls() do { } while (0)
1666#endif /* CONFIG_SYSCTL */
1667
1668static int __init
1669init_sg(void)
1670{
1671	int rc;
1672
1673	if (scatter_elem_sz < PAGE_SIZE) {
1674		scatter_elem_sz = PAGE_SIZE;
1675		scatter_elem_sz_prev = scatter_elem_sz;
1676	}
1677	if (def_reserved_size >= 0)
1678		sg_big_buff = def_reserved_size;
1679	else
1680		def_reserved_size = sg_big_buff;
1681
1682	rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), 
1683				    SG_MAX_DEVS, "sg");
1684	if (rc)
1685		return rc;
1686	rc = class_register(&sg_sysfs_class);
1687	if (rc)
1688		goto err_out;
1689	sg_sysfs_valid = 1;
1690	rc = scsi_register_interface(&sg_interface);
1691	if (0 == rc) {
1692#ifdef CONFIG_SCSI_PROC_FS
1693		sg_proc_init();
1694#endif				/* CONFIG_SCSI_PROC_FS */
1695		return 0;
1696	}
1697	class_unregister(&sg_sysfs_class);
1698	register_sg_sysctls();
1699err_out:
1700	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1701	return rc;
1702}
1703
1704static void __exit
1705exit_sg(void)
1706{
1707	unregister_sg_sysctls();
1708#ifdef CONFIG_SCSI_PROC_FS
1709	remove_proc_subtree("scsi/sg", NULL);
1710#endif				/* CONFIG_SCSI_PROC_FS */
1711	scsi_unregister_interface(&sg_interface);
1712	class_unregister(&sg_sysfs_class);
1713	sg_sysfs_valid = 0;
1714	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1715				 SG_MAX_DEVS);
1716	idr_destroy(&sg_index_idr);
1717}
1718
1719static int
1720sg_start_req(Sg_request *srp, unsigned char *cmd)
1721{
1722	int res;
1723	struct request *rq;
1724	Sg_fd *sfp = srp->parentfp;
1725	sg_io_hdr_t *hp = &srp->header;
1726	int dxfer_len = (int) hp->dxfer_len;
1727	int dxfer_dir = hp->dxfer_direction;
1728	unsigned int iov_count = hp->iovec_count;
1729	Sg_scatter_hold *req_schp = &srp->data;
1730	Sg_scatter_hold *rsv_schp = &sfp->reserve;
1731	struct request_queue *q = sfp->parentdp->device->request_queue;
1732	struct rq_map_data *md, map_data;
1733	int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? ITER_SOURCE : ITER_DEST;
1734	struct scsi_cmnd *scmd;
1735
1736	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1737				      "sg_start_req: dxfer_len=%d\n",
1738				      dxfer_len));
1739
1740	/*
1741	 * NOTE
1742	 *
1743	 * With scsi-mq enabled, there are a fixed number of preallocated
1744	 * requests equal in number to shost->can_queue.  If all of the
1745	 * preallocated requests are already in use, then scsi_alloc_request()
1746	 * will sleep until an active command completes, freeing up a request.
1747	 * Although waiting in an asynchronous interface is less than ideal, we
1748	 * do not want to use BLK_MQ_REQ_NOWAIT here because userspace might
1749	 * not expect an EWOULDBLOCK from this condition.
1750	 */
1751	rq = scsi_alloc_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
1752			REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
1753	if (IS_ERR(rq))
1754		return PTR_ERR(rq);
1755	scmd = blk_mq_rq_to_pdu(rq);
1756
1757	if (hp->cmd_len > sizeof(scmd->cmnd)) {
1758		blk_mq_free_request(rq);
1759		return -EINVAL;
1760	}
1761
1762	memcpy(scmd->cmnd, cmd, hp->cmd_len);
1763	scmd->cmd_len = hp->cmd_len;
1764
1765	srp->rq = rq;
1766	rq->end_io_data = srp;
1767	scmd->allowed = SG_DEFAULT_RETRIES;
1768
1769	if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1770		return 0;
1771
1772	if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1773	    dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1774	    blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1775		md = NULL;
1776	else
1777		md = &map_data;
1778
1779	if (md) {
1780		mutex_lock(&sfp->f_mutex);
1781		if (dxfer_len <= rsv_schp->bufflen &&
1782		    !sfp->res_in_use) {
1783			sfp->res_in_use = 1;
1784			sg_link_reserve(sfp, srp, dxfer_len);
1785		} else if (hp->flags & SG_FLAG_MMAP_IO) {
1786			res = -EBUSY; /* sfp->res_in_use == 1 */
1787			if (dxfer_len > rsv_schp->bufflen)
1788				res = -ENOMEM;
1789			mutex_unlock(&sfp->f_mutex);
1790			return res;
1791		} else {
1792			res = sg_build_indirect(req_schp, sfp, dxfer_len);
1793			if (res) {
1794				mutex_unlock(&sfp->f_mutex);
1795				return res;
1796			}
1797		}
1798		mutex_unlock(&sfp->f_mutex);
1799
1800		md->pages = req_schp->pages;
1801		md->page_order = req_schp->page_order;
1802		md->nr_entries = req_schp->k_use_sg;
1803		md->offset = 0;
1804		md->null_mapped = hp->dxferp ? 0 : 1;
1805		if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1806			md->from_user = 1;
1807		else
1808			md->from_user = 0;
1809	}
1810
1811	res = blk_rq_map_user_io(rq, md, hp->dxferp, hp->dxfer_len,
1812			GFP_ATOMIC, iov_count, iov_count, 1, rw);
1813	if (!res) {
1814		srp->bio = rq->bio;
1815
1816		if (!md) {
1817			req_schp->dio_in_use = 1;
1818			hp->info |= SG_INFO_DIRECT_IO;
1819		}
1820	}
1821	return res;
1822}
1823
1824static int
1825sg_finish_rem_req(Sg_request *srp)
1826{
1827	int ret = 0;
1828
1829	Sg_fd *sfp = srp->parentfp;
1830	Sg_scatter_hold *req_schp = &srp->data;
1831
1832	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1833				      "sg_finish_rem_req: res_used=%d\n",
1834				      (int) srp->res_used));
1835	if (srp->bio)
1836		ret = blk_rq_unmap_user(srp->bio);
1837
1838	if (srp->rq)
1839		blk_mq_free_request(srp->rq);
1840
1841	if (srp->res_used)
1842		sg_unlink_reserve(sfp, srp);
1843	else
1844		sg_remove_scat(sfp, req_schp);
1845
1846	return ret;
1847}
1848
1849static int
1850sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1851{
1852	int sg_bufflen = tablesize * sizeof(struct page *);
1853	gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1854
1855	schp->pages = kzalloc(sg_bufflen, gfp_flags);
1856	if (!schp->pages)
1857		return -ENOMEM;
1858	schp->sglist_len = sg_bufflen;
1859	return tablesize;	/* number of scat_gath elements allocated */
1860}
1861
1862static int
1863sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1864{
1865	int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1866	int sg_tablesize = sfp->parentdp->sg_tablesize;
1867	int blk_size = buff_size, order;
1868	gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
1869
1870	if (blk_size < 0)
1871		return -EFAULT;
1872	if (0 == blk_size)
1873		++blk_size;	/* don't know why */
1874	/* round request up to next highest SG_SECTOR_SZ byte boundary */
1875	blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1876	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1877		"sg_build_indirect: buff_size=%d, blk_size=%d\n",
1878		buff_size, blk_size));
1879
1880	/* N.B. ret_sz carried into this block ... */
1881	mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1882	if (mx_sc_elems < 0)
1883		return mx_sc_elems;	/* most likely -ENOMEM */
1884
1885	num = scatter_elem_sz;
1886	if (unlikely(num != scatter_elem_sz_prev)) {
1887		if (num < PAGE_SIZE) {
1888			scatter_elem_sz = PAGE_SIZE;
1889			scatter_elem_sz_prev = PAGE_SIZE;
1890		} else
1891			scatter_elem_sz_prev = num;
1892	}
1893
1894	order = get_order(num);
1895retry:
1896	ret_sz = 1 << (PAGE_SHIFT + order);
1897
1898	for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1899	     k++, rem_sz -= ret_sz) {
1900
1901		num = (rem_sz > scatter_elem_sz_prev) ?
1902			scatter_elem_sz_prev : rem_sz;
1903
1904		schp->pages[k] = alloc_pages(gfp_mask, order);
1905		if (!schp->pages[k])
1906			goto out;
1907
1908		if (num == scatter_elem_sz_prev) {
1909			if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1910				scatter_elem_sz = ret_sz;
1911				scatter_elem_sz_prev = ret_sz;
1912			}
1913		}
1914
1915		SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1916				 "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1917				 k, num, ret_sz));
1918	}		/* end of for loop */
1919
1920	schp->page_order = order;
1921	schp->k_use_sg = k;
1922	SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1923			 "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1924			 k, rem_sz));
1925
1926	schp->bufflen = blk_size;
1927	if (rem_sz > 0)	/* must have failed */
1928		return -ENOMEM;
1929	return 0;
1930out:
1931	for (i = 0; i < k; i++)
1932		__free_pages(schp->pages[i], order);
1933
1934	if (--order >= 0)
1935		goto retry;
1936
1937	return -ENOMEM;
1938}
1939
1940static void
1941sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1942{
1943	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1944			 "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1945	if (schp->pages && schp->sglist_len > 0) {
1946		if (!schp->dio_in_use) {
1947			int k;
1948
1949			for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1950				SCSI_LOG_TIMEOUT(5,
1951					sg_printk(KERN_INFO, sfp->parentdp,
1952					"sg_remove_scat: k=%d, pg=0x%p\n",
1953					k, schp->pages[k]));
1954				__free_pages(schp->pages[k], schp->page_order);
1955			}
1956
1957			kfree(schp->pages);
1958		}
1959	}
1960	memset(schp, 0, sizeof (*schp));
1961}
1962
1963static int
1964sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1965{
1966	Sg_scatter_hold *schp = &srp->data;
1967	int k, num;
1968
1969	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1970			 "sg_read_oxfer: num_read_xfer=%d\n",
1971			 num_read_xfer));
1972	if ((!outp) || (num_read_xfer <= 0))
1973		return 0;
1974
1975	num = 1 << (PAGE_SHIFT + schp->page_order);
1976	for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1977		if (num > num_read_xfer) {
1978			if (copy_to_user(outp, page_address(schp->pages[k]),
1979					   num_read_xfer))
1980				return -EFAULT;
1981			break;
1982		} else {
1983			if (copy_to_user(outp, page_address(schp->pages[k]),
1984					   num))
1985				return -EFAULT;
1986			num_read_xfer -= num;
1987			if (num_read_xfer <= 0)
1988				break;
1989			outp += num;
1990		}
1991	}
1992
1993	return 0;
1994}
1995
1996static void
1997sg_build_reserve(Sg_fd * sfp, int req_size)
1998{
1999	Sg_scatter_hold *schp = &sfp->reserve;
2000
2001	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2002			 "sg_build_reserve: req_size=%d\n", req_size));
2003	do {
2004		if (req_size < PAGE_SIZE)
2005			req_size = PAGE_SIZE;
2006		if (0 == sg_build_indirect(schp, sfp, req_size))
2007			return;
2008		else
2009			sg_remove_scat(sfp, schp);
2010		req_size >>= 1;	/* divide by 2 */
2011	} while (req_size > (PAGE_SIZE / 2));
2012}
2013
2014static void
2015sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2016{
2017	Sg_scatter_hold *req_schp = &srp->data;
2018	Sg_scatter_hold *rsv_schp = &sfp->reserve;
2019	int k, num, rem;
2020
2021	srp->res_used = 1;
2022	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2023			 "sg_link_reserve: size=%d\n", size));
2024	rem = size;
2025
2026	num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
2027	for (k = 0; k < rsv_schp->k_use_sg; k++) {
2028		if (rem <= num) {
2029			req_schp->k_use_sg = k + 1;
2030			req_schp->sglist_len = rsv_schp->sglist_len;
2031			req_schp->pages = rsv_schp->pages;
2032
2033			req_schp->bufflen = size;
2034			req_schp->page_order = rsv_schp->page_order;
2035			break;
2036		} else
2037			rem -= num;
2038	}
2039
2040	if (k >= rsv_schp->k_use_sg)
2041		SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2042				 "sg_link_reserve: BAD size\n"));
2043}
2044
2045static void
2046sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2047{
2048	Sg_scatter_hold *req_schp = &srp->data;
2049
2050	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2051				      "sg_unlink_reserve: req->k_use_sg=%d\n",
2052				      (int) req_schp->k_use_sg));
2053	req_schp->k_use_sg = 0;
2054	req_schp->bufflen = 0;
2055	req_schp->pages = NULL;
2056	req_schp->page_order = 0;
2057	req_schp->sglist_len = 0;
2058	srp->res_used = 0;
2059	/* Called without mutex lock to avoid deadlock */
2060	sfp->res_in_use = 0;
2061}
2062
2063static Sg_request *
2064sg_get_rq_mark(Sg_fd * sfp, int pack_id, bool *busy)
2065{
2066	Sg_request *resp;
2067	unsigned long iflags;
2068
2069	*busy = false;
2070	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2071	list_for_each_entry(resp, &sfp->rq_list, entry) {
2072		/* look for requests that are not SG_IO owned */
2073		if ((!resp->sg_io_owned) &&
2074		    ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2075			switch (resp->done) {
2076			case 0: /* request active */
2077				*busy = true;
2078				break;
2079			case 1: /* request done; response ready to return */
2080				resp->done = 2;	/* guard against other readers */
2081				write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2082				return resp;
2083			case 2: /* response already being returned */
2084				break;
2085			}
2086		}
2087	}
2088	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2089	return NULL;
2090}
2091
2092/* always adds to end of list */
2093static Sg_request *
2094sg_add_request(Sg_fd * sfp)
2095{
2096	int k;
2097	unsigned long iflags;
2098	Sg_request *rp = sfp->req_arr;
2099
2100	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2101	if (!list_empty(&sfp->rq_list)) {
2102		if (!sfp->cmd_q)
2103			goto out_unlock;
2104
2105		for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2106			if (!rp->parentfp)
2107				break;
2108		}
2109		if (k >= SG_MAX_QUEUE)
2110			goto out_unlock;
2111	}
2112	memset(rp, 0, sizeof (Sg_request));
2113	rp->parentfp = sfp;
2114	rp->header.duration = jiffies_to_msecs(jiffies);
2115	list_add_tail(&rp->entry, &sfp->rq_list);
2116	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2117	return rp;
2118out_unlock:
2119	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2120	return NULL;
2121}
2122
2123/* Return of 1 for found; 0 for not found */
2124static int
2125sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2126{
2127	unsigned long iflags;
2128	int res = 0;
2129
2130	if (!sfp || !srp || list_empty(&sfp->rq_list))
2131		return res;
2132	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2133	if (!list_empty(&srp->entry)) {
2134		list_del(&srp->entry);
2135		srp->parentfp = NULL;
2136		res = 1;
2137	}
2138	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2139
2140	/*
2141	 * If the device is detaching, wakeup any readers in case we just
2142	 * removed the last response, which would leave nothing for them to
2143	 * return other than -ENODEV.
2144	 */
2145	if (unlikely(atomic_read(&sfp->parentdp->detaching)))
2146		wake_up_interruptible_all(&sfp->read_wait);
2147
2148	return res;
2149}
2150
2151static Sg_fd *
2152sg_add_sfp(Sg_device * sdp)
2153{
2154	Sg_fd *sfp;
2155	unsigned long iflags;
2156	int bufflen;
2157
2158	sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2159	if (!sfp)
2160		return ERR_PTR(-ENOMEM);
2161
2162	init_waitqueue_head(&sfp->read_wait);
2163	rwlock_init(&sfp->rq_list_lock);
2164	INIT_LIST_HEAD(&sfp->rq_list);
2165	kref_init(&sfp->f_ref);
2166	mutex_init(&sfp->f_mutex);
2167	sfp->timeout = SG_DEFAULT_TIMEOUT;
2168	sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2169	sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2170	sfp->cmd_q = SG_DEF_COMMAND_Q;
2171	sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2172	sfp->parentdp = sdp;
2173	write_lock_irqsave(&sdp->sfd_lock, iflags);
2174	if (atomic_read(&sdp->detaching)) {
2175		write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2176		kfree(sfp);
2177		return ERR_PTR(-ENODEV);
2178	}
2179	list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2180	write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2181	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2182				      "sg_add_sfp: sfp=0x%p\n", sfp));
2183	if (unlikely(sg_big_buff != def_reserved_size))
2184		sg_big_buff = def_reserved_size;
2185
2186	bufflen = min_t(int, sg_big_buff,
2187			max_sectors_bytes(sdp->device->request_queue));
2188	sg_build_reserve(sfp, bufflen);
2189	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2190				      "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2191				      sfp->reserve.bufflen,
2192				      sfp->reserve.k_use_sg));
2193
2194	kref_get(&sdp->d_ref);
2195	__module_get(THIS_MODULE);
2196	return sfp;
2197}
2198
2199static void
2200sg_remove_sfp_usercontext(struct work_struct *work)
2201{
2202	struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2203	struct sg_device *sdp = sfp->parentdp;
2204	struct scsi_device *device = sdp->device;
2205	Sg_request *srp;
2206	unsigned long iflags;
2207
2208	/* Cleanup any responses which were never read(). */
2209	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2210	while (!list_empty(&sfp->rq_list)) {
2211		srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2212		list_del(&srp->entry);
2213		write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2214
2215		sg_finish_rem_req(srp);
2216		/*
2217		 * sg_rq_end_io() uses srp->parentfp. Hence, only clear
2218		 * srp->parentfp after blk_mq_free_request() has been called.
2219		 */
2220		srp->parentfp = NULL;
2221
2222		write_lock_irqsave(&sfp->rq_list_lock, iflags);
2223	}
2224	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2225
2226	if (sfp->reserve.bufflen > 0) {
2227		SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2228				"sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2229				(int) sfp->reserve.bufflen,
2230				(int) sfp->reserve.k_use_sg));
2231		sg_remove_scat(sfp, &sfp->reserve);
2232	}
2233
2234	SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2235			"sg_remove_sfp: sfp=0x%p\n", sfp));
2236	kfree(sfp);
2237
2238	kref_put(&sdp->d_ref, sg_device_destroy);
2239	scsi_device_put(device);
2240	module_put(THIS_MODULE);
2241}
2242
2243static void
2244sg_remove_sfp(struct kref *kref)
2245{
2246	struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2247	struct sg_device *sdp = sfp->parentdp;
2248	unsigned long iflags;
2249
2250	write_lock_irqsave(&sdp->sfd_lock, iflags);
2251	list_del(&sfp->sfd_siblings);
2252	write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2253
2254	INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2255	schedule_work(&sfp->ew.work);
2256}
2257
2258#ifdef CONFIG_SCSI_PROC_FS
2259static int
2260sg_idr_max_id(int id, void *p, void *data)
2261{
2262	int *k = data;
2263
2264	if (*k < id)
2265		*k = id;
2266
2267	return 0;
2268}
2269
2270static int
2271sg_last_dev(void)
2272{
2273	int k = -1;
2274	unsigned long iflags;
2275
2276	read_lock_irqsave(&sg_index_lock, iflags);
2277	idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2278	read_unlock_irqrestore(&sg_index_lock, iflags);
2279	return k + 1;		/* origin 1 */
2280}
2281#endif
2282
2283/* must be called with sg_index_lock held */
2284static Sg_device *sg_lookup_dev(int dev)
2285{
2286	return idr_find(&sg_index_idr, dev);
2287}
2288
2289static Sg_device *
2290sg_get_dev(int dev)
2291{
2292	struct sg_device *sdp;
2293	unsigned long flags;
2294
2295	read_lock_irqsave(&sg_index_lock, flags);
2296	sdp = sg_lookup_dev(dev);
2297	if (!sdp)
2298		sdp = ERR_PTR(-ENXIO);
2299	else if (atomic_read(&sdp->detaching)) {
2300		/* If sdp->detaching, then the refcount may already be 0, in
2301		 * which case it would be a bug to do kref_get().
2302		 */
2303		sdp = ERR_PTR(-ENODEV);
2304	} else
2305		kref_get(&sdp->d_ref);
2306	read_unlock_irqrestore(&sg_index_lock, flags);
2307
2308	return sdp;
2309}
2310
2311#ifdef CONFIG_SCSI_PROC_FS
2312static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2313
2314static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2315static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2316			          size_t count, loff_t *off);
2317static const struct proc_ops adio_proc_ops = {
2318	.proc_open	= sg_proc_single_open_adio,
2319	.proc_read	= seq_read,
2320	.proc_lseek	= seq_lseek,
2321	.proc_write	= sg_proc_write_adio,
2322	.proc_release	= single_release,
2323};
2324
2325static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2326static ssize_t sg_proc_write_dressz(struct file *filp, 
2327		const char __user *buffer, size_t count, loff_t *off);
2328static const struct proc_ops dressz_proc_ops = {
2329	.proc_open	= sg_proc_single_open_dressz,
2330	.proc_read	= seq_read,
2331	.proc_lseek	= seq_lseek,
2332	.proc_write	= sg_proc_write_dressz,
2333	.proc_release	= single_release,
2334};
2335
2336static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2337static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2338static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2339static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2340static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2341static void dev_seq_stop(struct seq_file *s, void *v);
2342static const struct seq_operations dev_seq_ops = {
2343	.start = dev_seq_start,
2344	.next  = dev_seq_next,
2345	.stop  = dev_seq_stop,
2346	.show  = sg_proc_seq_show_dev,
2347};
2348
2349static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2350static const struct seq_operations devstrs_seq_ops = {
2351	.start = dev_seq_start,
2352	.next  = dev_seq_next,
2353	.stop  = dev_seq_stop,
2354	.show  = sg_proc_seq_show_devstrs,
2355};
2356
2357static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2358static const struct seq_operations debug_seq_ops = {
2359	.start = dev_seq_start,
2360	.next  = dev_seq_next,
2361	.stop  = dev_seq_stop,
2362	.show  = sg_proc_seq_show_debug,
2363};
2364
2365static int
2366sg_proc_init(void)
2367{
2368	struct proc_dir_entry *p;
2369
2370	p = proc_mkdir("scsi/sg", NULL);
2371	if (!p)
2372		return 1;
2373
2374	proc_create("allow_dio", S_IRUGO | S_IWUSR, p, &adio_proc_ops);
2375	proc_create_seq("debug", S_IRUGO, p, &debug_seq_ops);
2376	proc_create("def_reserved_size", S_IRUGO | S_IWUSR, p, &dressz_proc_ops);
2377	proc_create_single("device_hdr", S_IRUGO, p, sg_proc_seq_show_devhdr);
2378	proc_create_seq("devices", S_IRUGO, p, &dev_seq_ops);
2379	proc_create_seq("device_strs", S_IRUGO, p, &devstrs_seq_ops);
2380	proc_create_single("version", S_IRUGO, p, sg_proc_seq_show_version);
2381	return 0;
2382}
2383
2384
2385static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2386{
2387	seq_printf(s, "%d\n", *((int *)s->private));
2388	return 0;
2389}
2390
2391static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2392{
2393	return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2394}
2395
2396static ssize_t 
2397sg_proc_write_adio(struct file *filp, const char __user *buffer,
2398		   size_t count, loff_t *off)
2399{
2400	int err;
2401	unsigned long num;
2402
2403	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2404		return -EACCES;
2405	err = kstrtoul_from_user(buffer, count, 0, &num);
2406	if (err)
2407		return err;
2408	sg_allow_dio = num ? 1 : 0;
2409	return count;
2410}
2411
2412static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2413{
2414	return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2415}
2416
2417static ssize_t 
2418sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2419		     size_t count, loff_t *off)
2420{
2421	int err;
2422	unsigned long k = ULONG_MAX;
2423
2424	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2425		return -EACCES;
2426
2427	err = kstrtoul_from_user(buffer, count, 0, &k);
2428	if (err)
2429		return err;
2430	if (k <= 1048576) {	/* limit "big buff" to 1 MB */
2431		sg_big_buff = k;
2432		return count;
2433	}
2434	return -ERANGE;
2435}
2436
2437static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2438{
2439	seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2440		   sg_version_date);
2441	return 0;
2442}
2443
2444static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2445{
2446	seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2447	return 0;
2448}
2449
2450struct sg_proc_deviter {
2451	loff_t	index;
2452	size_t	max;
2453};
2454
2455static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2456{
2457	struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2458
2459	s->private = it;
2460	if (! it)
2461		return NULL;
2462
2463	it->index = *pos;
2464	it->max = sg_last_dev();
2465	if (it->index >= it->max)
2466		return NULL;
2467	return it;
2468}
2469
2470static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2471{
2472	struct sg_proc_deviter * it = s->private;
2473
2474	*pos = ++it->index;
2475	return (it->index < it->max) ? it : NULL;
2476}
2477
2478static void dev_seq_stop(struct seq_file *s, void *v)
2479{
2480	kfree(s->private);
2481}
2482
2483static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2484{
2485	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2486	Sg_device *sdp;
2487	struct scsi_device *scsidp;
2488	unsigned long iflags;
2489
2490	read_lock_irqsave(&sg_index_lock, iflags);
2491	sdp = it ? sg_lookup_dev(it->index) : NULL;
2492	if ((NULL == sdp) || (NULL == sdp->device) ||
2493	    (atomic_read(&sdp->detaching)))
2494		seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2495	else {
2496		scsidp = sdp->device;
2497		seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2498			      scsidp->host->host_no, scsidp->channel,
2499			      scsidp->id, scsidp->lun, (int) scsidp->type,
2500			      1,
2501			      (int) scsidp->queue_depth,
2502			      (int) scsi_device_busy(scsidp),
2503			      (int) scsi_device_online(scsidp));
2504	}
2505	read_unlock_irqrestore(&sg_index_lock, iflags);
2506	return 0;
2507}
2508
2509static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2510{
2511	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2512	Sg_device *sdp;
2513	struct scsi_device *scsidp;
2514	unsigned long iflags;
2515
2516	read_lock_irqsave(&sg_index_lock, iflags);
2517	sdp = it ? sg_lookup_dev(it->index) : NULL;
2518	scsidp = sdp ? sdp->device : NULL;
2519	if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2520		seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2521			   scsidp->vendor, scsidp->model, scsidp->rev);
2522	else
2523		seq_puts(s, "<no active device>\n");
2524	read_unlock_irqrestore(&sg_index_lock, iflags);
2525	return 0;
2526}
2527
2528/* must be called while holding sg_index_lock */
2529static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2530{
2531	int k, new_interface, blen, usg;
2532	Sg_request *srp;
2533	Sg_fd *fp;
2534	const sg_io_hdr_t *hp;
2535	const char * cp;
2536	unsigned int ms;
2537	unsigned int duration;
2538
2539	k = 0;
2540	list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2541		k++;
2542		read_lock(&fp->rq_list_lock); /* irqs already disabled */
2543		seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2544			   "(res)sgat=%d low_dma=%d\n", k,
2545			   jiffies_to_msecs(fp->timeout),
2546			   fp->reserve.bufflen,
2547			   (int) fp->reserve.k_use_sg, 0);
2548		seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2549			   (int) fp->cmd_q, (int) fp->force_packid,
2550			   (int) fp->keep_orphan);
2551		list_for_each_entry(srp, &fp->rq_list, entry) {
2552			hp = &srp->header;
2553			new_interface = (hp->interface_id == '\0') ? 0 : 1;
2554			if (srp->res_used) {
2555				if (new_interface &&
2556				    (SG_FLAG_MMAP_IO & hp->flags))
2557					cp = "     mmap>> ";
2558				else
2559					cp = "     rb>> ";
2560			} else {
2561				if (SG_INFO_DIRECT_IO_MASK & hp->info)
2562					cp = "     dio>> ";
2563				else
2564					cp = "     ";
2565			}
2566			seq_puts(s, cp);
2567			blen = srp->data.bufflen;
2568			usg = srp->data.k_use_sg;
2569			seq_puts(s, srp->done ?
2570				 ((1 == srp->done) ?  "rcv:" : "fin:")
2571				  : "act:");
2572			seq_printf(s, " id=%d blen=%d",
2573				   srp->header.pack_id, blen);
2574			if (srp->done)
2575				seq_printf(s, " dur=%u", hp->duration);
2576			else {
2577				ms = jiffies_to_msecs(jiffies);
2578				duration = READ_ONCE(hp->duration);
2579				if (duration)
2580					duration = (ms > duration ?
2581						    ms - duration : 0);
2582				seq_printf(s, " t_o/elap=%u/%u",
2583					(new_interface ? hp->timeout :
2584						  jiffies_to_msecs(fp->timeout)),
2585					duration);
2586			}
2587			seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2588				   (int) srp->data.cmd_opcode);
2589		}
2590		if (list_empty(&fp->rq_list))
2591			seq_puts(s, "     No requests active\n");
2592		read_unlock(&fp->rq_list_lock);
2593	}
2594}
2595
2596static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2597{
2598	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2599	Sg_device *sdp;
2600	unsigned long iflags;
2601
2602	if (it && (0 == it->index))
2603		seq_printf(s, "max_active_device=%d  def_reserved_size=%d\n",
2604			   (int)it->max, sg_big_buff);
2605
2606	read_lock_irqsave(&sg_index_lock, iflags);
2607	sdp = it ? sg_lookup_dev(it->index) : NULL;
2608	if (NULL == sdp)
2609		goto skip;
2610	read_lock(&sdp->sfd_lock);
2611	if (!list_empty(&sdp->sfds)) {
2612		seq_printf(s, " >>> device=%s ", sdp->name);
2613		if (atomic_read(&sdp->detaching))
2614			seq_puts(s, "detaching pending close ");
2615		else if (sdp->device) {
2616			struct scsi_device *scsidp = sdp->device;
2617
2618			seq_printf(s, "%d:%d:%d:%llu   em=%d",
2619				   scsidp->host->host_no,
2620				   scsidp->channel, scsidp->id,
2621				   scsidp->lun,
2622				   scsidp->host->hostt->emulated);
2623		}
2624		seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2625			   sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2626		sg_proc_debug_helper(s, sdp);
2627	}
2628	read_unlock(&sdp->sfd_lock);
2629skip:
2630	read_unlock_irqrestore(&sg_index_lock, iflags);
2631	return 0;
2632}
2633
2634#endif				/* CONFIG_SCSI_PROC_FS */
2635
2636module_init(init_sg);
2637module_exit(exit_sg);