xref: /openbmc/linux/drivers/scsi/sg.c (revision 97da55fc)
1 /*
2  *  History:
3  *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
4  *           to allow user process control of SCSI devices.
5  *  Development Sponsored by Killy Corp. NY NY
6  *
7  * Original driver (sg.c):
8  *        Copyright (C) 1992 Lawrence Foard
9  * Version 2 and 3 extensions to driver:
10  *        Copyright (C) 1998 - 2005 Douglas Gilbert
11  *
12  *  Modified  19-JAN-1998  Richard Gooch <rgooch@atnf.csiro.au>  Devfs support
13  *
14  * This program is free software; you can redistribute it and/or modify
15  * it under the terms of the GNU General Public License as published by
16  * the Free Software Foundation; either version 2, or (at your option)
17  * any later version.
18  *
19  */
20 
21 static int sg_version_num = 30534;	/* 2 digits for each component */
22 #define SG_VERSION_STR "3.5.34"
23 
24 /*
25  *  D. P. Gilbert (dgilbert@interlog.com, dougg@triode.net.au), notes:
26  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
27  *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
28  *        (otherwise the macros compile to empty statements).
29  *
30  */
31 #include <linux/module.h>
32 
33 #include <linux/fs.h>
34 #include <linux/kernel.h>
35 #include <linux/sched.h>
36 #include <linux/string.h>
37 #include <linux/mm.h>
38 #include <linux/errno.h>
39 #include <linux/mtio.h>
40 #include <linux/ioctl.h>
41 #include <linux/slab.h>
42 #include <linux/fcntl.h>
43 #include <linux/init.h>
44 #include <linux/poll.h>
45 #include <linux/moduleparam.h>
46 #include <linux/cdev.h>
47 #include <linux/idr.h>
48 #include <linux/seq_file.h>
49 #include <linux/blkdev.h>
50 #include <linux/delay.h>
51 #include <linux/blktrace_api.h>
52 #include <linux/mutex.h>
53 #include <linux/ratelimit.h>
54 
55 #include "scsi.h"
56 #include <scsi/scsi_dbg.h>
57 #include <scsi/scsi_host.h>
58 #include <scsi/scsi_driver.h>
59 #include <scsi/scsi_ioctl.h>
60 #include <scsi/sg.h>
61 
62 #include "scsi_logging.h"
63 
64 #ifdef CONFIG_SCSI_PROC_FS
65 #include <linux/proc_fs.h>
66 static char *sg_version_date = "20061027";
67 
68 static int sg_proc_init(void);
69 static void sg_proc_cleanup(void);
70 #endif
71 
72 #define SG_ALLOW_DIO_DEF 0
73 
74 #define SG_MAX_DEVS 32768
75 
76 /*
77  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
78  * Then when using 32 bit integers x * m may overflow during the calculation.
79  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
80  * calculates the same, but prevents the overflow when both m and d
81  * are "small" numbers (like HZ and USER_HZ).
82  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
83  * in 32 bits.
84  */
85 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
86 
87 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
88 
89 int sg_big_buff = SG_DEF_RESERVED_SIZE;
90 /* N.B. This variable is readable and writeable via
91    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
92    of this size (or less if there is not enough memory) will be reserved
93    for use by this file descriptor. [Deprecated usage: this variable is also
94    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
95    the kernel (i.e. it is not a module).] */
96 static int def_reserved_size = -1;	/* picks up init parameter */
97 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
98 
99 static int scatter_elem_sz = SG_SCATTER_SZ;
100 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
101 
102 #define SG_SECTOR_SZ 512
103 
104 static int sg_add(struct device *, struct class_interface *);
105 static void sg_remove(struct device *, struct class_interface *);
106 
107 static DEFINE_SPINLOCK(sg_open_exclusive_lock);
108 
109 static DEFINE_IDR(sg_index_idr);
110 static DEFINE_RWLOCK(sg_index_lock);	/* Also used to lock
111 							   file descriptor list for device */
112 
113 static struct class_interface sg_interface = {
114 	.add_dev	= sg_add,
115 	.remove_dev	= sg_remove,
116 };
117 
118 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
119 	unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
120 	unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
121 	unsigned bufflen;	/* Size of (aggregate) data buffer */
122 	struct page **pages;
123 	int page_order;
124 	char dio_in_use;	/* 0->indirect IO (or mmap), 1->dio */
125 	unsigned char cmd_opcode; /* first byte of command */
126 } Sg_scatter_hold;
127 
128 struct sg_device;		/* forward declarations */
129 struct sg_fd;
130 
131 typedef struct sg_request {	/* SG_MAX_QUEUE requests outstanding per file */
132 	struct sg_request *nextrp;	/* NULL -> tail request (slist) */
133 	struct sg_fd *parentfp;	/* NULL -> not in use */
134 	Sg_scatter_hold data;	/* hold buffer, perhaps scatter list */
135 	sg_io_hdr_t header;	/* scsi command+info, see <scsi/sg.h> */
136 	unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
137 	char res_used;		/* 1 -> using reserve buffer, 0 -> not ... */
138 	char orphan;		/* 1 -> drop on sight, 0 -> normal */
139 	char sg_io_owned;	/* 1 -> packet belongs to SG_IO */
140 	/* done protected by rq_list_lock */
141 	char done;		/* 0->before bh, 1->before read, 2->read */
142 	struct request *rq;
143 	struct bio *bio;
144 	struct execute_work ew;
145 } Sg_request;
146 
147 typedef struct sg_fd {		/* holds the state of a file descriptor */
148 	/* sfd_siblings is protected by sg_index_lock */
149 	struct list_head sfd_siblings;
150 	struct sg_device *parentdp;	/* owning device */
151 	wait_queue_head_t read_wait;	/* queue read until command done */
152 	rwlock_t rq_list_lock;	/* protect access to list in req_arr */
153 	int timeout;		/* defaults to SG_DEFAULT_TIMEOUT      */
154 	int timeout_user;	/* defaults to SG_DEFAULT_TIMEOUT_USER */
155 	Sg_scatter_hold reserve;	/* buffer held for this file descriptor */
156 	unsigned save_scat_len;	/* original length of trunc. scat. element */
157 	Sg_request *headrp;	/* head of request slist, NULL->empty */
158 	struct fasync_struct *async_qp;	/* used by asynchronous notification */
159 	Sg_request req_arr[SG_MAX_QUEUE];	/* used as singly-linked list */
160 	char low_dma;		/* as in parent but possibly overridden to 1 */
161 	char force_packid;	/* 1 -> pack_id input to read(), 0 -> ignored */
162 	char cmd_q;		/* 1 -> allow command queuing, 0 -> don't */
163 	char next_cmd_len;	/* 0 -> automatic (def), >0 -> use on next write() */
164 	char keep_orphan;	/* 0 -> drop orphan (def), 1 -> keep for read() */
165 	char mmap_called;	/* 0 -> mmap() never called on this fd */
166 	struct kref f_ref;
167 	struct execute_work ew;
168 } Sg_fd;
169 
170 typedef struct sg_device { /* holds the state of each scsi generic device */
171 	struct scsi_device *device;
172 	wait_queue_head_t o_excl_wait;	/* queue open() when O_EXCL in use */
173 	int sg_tablesize;	/* adapter's max scatter-gather table size */
174 	u32 index;		/* device index number */
175 	/* sfds is protected by sg_index_lock */
176 	struct list_head sfds;
177 	volatile char detached;	/* 0->attached, 1->detached pending removal */
178 	/* exclude protected by sg_open_exclusive_lock */
179 	char exclude;		/* opened for exclusive access */
180 	char sgdebug;		/* 0->off, 1->sense, 9->dump dev, 10-> all devs */
181 	struct gendisk *disk;
182 	struct cdev * cdev;	/* char_dev [sysfs: /sys/cdev/major/sg<n>] */
183 	struct kref d_ref;
184 } Sg_device;
185 
186 /* tasklet or soft irq callback */
187 static void sg_rq_end_io(struct request *rq, int uptodate);
188 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
189 static int sg_finish_rem_req(Sg_request * srp);
190 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
191 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
192 			   Sg_request * srp);
193 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
194 			const char __user *buf, size_t count, int blocking,
195 			int read_only, int sg_io_owned, Sg_request **o_srp);
196 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
197 			   unsigned char *cmnd, int timeout, int blocking);
198 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
199 static void sg_remove_scat(Sg_scatter_hold * schp);
200 static void sg_build_reserve(Sg_fd * sfp, int req_size);
201 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
202 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
203 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
204 static void sg_remove_sfp(struct kref *);
205 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
206 static Sg_request *sg_add_request(Sg_fd * sfp);
207 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
208 static int sg_res_in_use(Sg_fd * sfp);
209 static Sg_device *sg_get_dev(int dev);
210 static void sg_put_dev(Sg_device *sdp);
211 
212 #define SZ_SG_HEADER sizeof(struct sg_header)
213 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
214 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
215 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
216 
217 static int sg_allow_access(struct file *filp, unsigned char *cmd)
218 {
219 	struct sg_fd *sfp = filp->private_data;
220 
221 	if (sfp->parentdp->device->type == TYPE_SCANNER)
222 		return 0;
223 
224 	return blk_verify_command(cmd, filp->f_mode & FMODE_WRITE);
225 }
226 
227 static int get_exclude(Sg_device *sdp)
228 {
229 	unsigned long flags;
230 	int ret;
231 
232 	spin_lock_irqsave(&sg_open_exclusive_lock, flags);
233 	ret = sdp->exclude;
234 	spin_unlock_irqrestore(&sg_open_exclusive_lock, flags);
235 	return ret;
236 }
237 
238 static int set_exclude(Sg_device *sdp, char val)
239 {
240 	unsigned long flags;
241 
242 	spin_lock_irqsave(&sg_open_exclusive_lock, flags);
243 	sdp->exclude = val;
244 	spin_unlock_irqrestore(&sg_open_exclusive_lock, flags);
245 	return val;
246 }
247 
248 static int sfds_list_empty(Sg_device *sdp)
249 {
250 	unsigned long flags;
251 	int ret;
252 
253 	read_lock_irqsave(&sg_index_lock, flags);
254 	ret = list_empty(&sdp->sfds);
255 	read_unlock_irqrestore(&sg_index_lock, flags);
256 	return ret;
257 }
258 
259 static int
260 sg_open(struct inode *inode, struct file *filp)
261 {
262 	int dev = iminor(inode);
263 	int flags = filp->f_flags;
264 	struct request_queue *q;
265 	Sg_device *sdp;
266 	Sg_fd *sfp;
267 	int res;
268 	int retval;
269 
270 	nonseekable_open(inode, filp);
271 	SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
272 	sdp = sg_get_dev(dev);
273 	if (IS_ERR(sdp)) {
274 		retval = PTR_ERR(sdp);
275 		sdp = NULL;
276 		goto sg_put;
277 	}
278 
279 	/* This driver's module count bumped by fops_get in <linux/fs.h> */
280 	/* Prevent the device driver from vanishing while we sleep */
281 	retval = scsi_device_get(sdp->device);
282 	if (retval)
283 		goto sg_put;
284 
285 	retval = scsi_autopm_get_device(sdp->device);
286 	if (retval)
287 		goto sdp_put;
288 
289 	if (!((flags & O_NONBLOCK) ||
290 	      scsi_block_when_processing_errors(sdp->device))) {
291 		retval = -ENXIO;
292 		/* we are in error recovery for this device */
293 		goto error_out;
294 	}
295 
296 	if (flags & O_EXCL) {
297 		if (O_RDONLY == (flags & O_ACCMODE)) {
298 			retval = -EPERM; /* Can't lock it with read only access */
299 			goto error_out;
300 		}
301 		if (!sfds_list_empty(sdp) && (flags & O_NONBLOCK)) {
302 			retval = -EBUSY;
303 			goto error_out;
304 		}
305 		res = wait_event_interruptible(sdp->o_excl_wait,
306 					   ((!sfds_list_empty(sdp) || get_exclude(sdp)) ? 0 : set_exclude(sdp, 1)));
307 		if (res) {
308 			retval = res;	/* -ERESTARTSYS because signal hit process */
309 			goto error_out;
310 		}
311 	} else if (get_exclude(sdp)) {	/* some other fd has an exclusive lock on dev */
312 		if (flags & O_NONBLOCK) {
313 			retval = -EBUSY;
314 			goto error_out;
315 		}
316 		res = wait_event_interruptible(sdp->o_excl_wait, !get_exclude(sdp));
317 		if (res) {
318 			retval = res;	/* -ERESTARTSYS because signal hit process */
319 			goto error_out;
320 		}
321 	}
322 	if (sdp->detached) {
323 		retval = -ENODEV;
324 		goto error_out;
325 	}
326 	if (sfds_list_empty(sdp)) {	/* no existing opens on this device */
327 		sdp->sgdebug = 0;
328 		q = sdp->device->request_queue;
329 		sdp->sg_tablesize = queue_max_segments(q);
330 	}
331 	if ((sfp = sg_add_sfp(sdp, dev)))
332 		filp->private_data = sfp;
333 	else {
334 		if (flags & O_EXCL) {
335 			set_exclude(sdp, 0);	/* undo if error */
336 			wake_up_interruptible(&sdp->o_excl_wait);
337 		}
338 		retval = -ENOMEM;
339 		goto error_out;
340 	}
341 	retval = 0;
342 error_out:
343 	if (retval) {
344 		scsi_autopm_put_device(sdp->device);
345 sdp_put:
346 		scsi_device_put(sdp->device);
347 	}
348 sg_put:
349 	if (sdp)
350 		sg_put_dev(sdp);
351 	return retval;
352 }
353 
354 /* Following function was formerly called 'sg_close' */
355 static int
356 sg_release(struct inode *inode, struct file *filp)
357 {
358 	Sg_device *sdp;
359 	Sg_fd *sfp;
360 
361 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
362 		return -ENXIO;
363 	SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
364 
365 	set_exclude(sdp, 0);
366 	wake_up_interruptible(&sdp->o_excl_wait);
367 
368 	scsi_autopm_put_device(sdp->device);
369 	kref_put(&sfp->f_ref, sg_remove_sfp);
370 	return 0;
371 }
372 
373 static ssize_t
374 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
375 {
376 	Sg_device *sdp;
377 	Sg_fd *sfp;
378 	Sg_request *srp;
379 	int req_pack_id = -1;
380 	sg_io_hdr_t *hp;
381 	struct sg_header *old_hdr = NULL;
382 	int retval = 0;
383 
384 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
385 		return -ENXIO;
386 	SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
387 				   sdp->disk->disk_name, (int) count));
388 
389 	if (!access_ok(VERIFY_WRITE, buf, count))
390 		return -EFAULT;
391 	if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
392 		old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
393 		if (!old_hdr)
394 			return -ENOMEM;
395 		if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
396 			retval = -EFAULT;
397 			goto free_old_hdr;
398 		}
399 		if (old_hdr->reply_len < 0) {
400 			if (count >= SZ_SG_IO_HDR) {
401 				sg_io_hdr_t *new_hdr;
402 				new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
403 				if (!new_hdr) {
404 					retval = -ENOMEM;
405 					goto free_old_hdr;
406 				}
407 				retval =__copy_from_user
408 				    (new_hdr, buf, SZ_SG_IO_HDR);
409 				req_pack_id = new_hdr->pack_id;
410 				kfree(new_hdr);
411 				if (retval) {
412 					retval = -EFAULT;
413 					goto free_old_hdr;
414 				}
415 			}
416 		} else
417 			req_pack_id = old_hdr->pack_id;
418 	}
419 	srp = sg_get_rq_mark(sfp, req_pack_id);
420 	if (!srp) {		/* now wait on packet to arrive */
421 		if (sdp->detached) {
422 			retval = -ENODEV;
423 			goto free_old_hdr;
424 		}
425 		if (filp->f_flags & O_NONBLOCK) {
426 			retval = -EAGAIN;
427 			goto free_old_hdr;
428 		}
429 		retval = wait_event_interruptible(sfp->read_wait,
430 			(sdp->detached ||
431 			(srp = sg_get_rq_mark(sfp, req_pack_id))));
432 		if (sdp->detached) {
433 			retval = -ENODEV;
434 			goto free_old_hdr;
435 		}
436 		if (retval) {
437 			/* -ERESTARTSYS as signal hit process */
438 			goto free_old_hdr;
439 		}
440 	}
441 	if (srp->header.interface_id != '\0') {
442 		retval = sg_new_read(sfp, buf, count, srp);
443 		goto free_old_hdr;
444 	}
445 
446 	hp = &srp->header;
447 	if (old_hdr == NULL) {
448 		old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
449 		if (! old_hdr) {
450 			retval = -ENOMEM;
451 			goto free_old_hdr;
452 		}
453 	}
454 	memset(old_hdr, 0, SZ_SG_HEADER);
455 	old_hdr->reply_len = (int) hp->timeout;
456 	old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
457 	old_hdr->pack_id = hp->pack_id;
458 	old_hdr->twelve_byte =
459 	    ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
460 	old_hdr->target_status = hp->masked_status;
461 	old_hdr->host_status = hp->host_status;
462 	old_hdr->driver_status = hp->driver_status;
463 	if ((CHECK_CONDITION & hp->masked_status) ||
464 	    (DRIVER_SENSE & hp->driver_status))
465 		memcpy(old_hdr->sense_buffer, srp->sense_b,
466 		       sizeof (old_hdr->sense_buffer));
467 	switch (hp->host_status) {
468 	/* This setup of 'result' is for backward compatibility and is best
469 	   ignored by the user who should use target, host + driver status */
470 	case DID_OK:
471 	case DID_PASSTHROUGH:
472 	case DID_SOFT_ERROR:
473 		old_hdr->result = 0;
474 		break;
475 	case DID_NO_CONNECT:
476 	case DID_BUS_BUSY:
477 	case DID_TIME_OUT:
478 		old_hdr->result = EBUSY;
479 		break;
480 	case DID_BAD_TARGET:
481 	case DID_ABORT:
482 	case DID_PARITY:
483 	case DID_RESET:
484 	case DID_BAD_INTR:
485 		old_hdr->result = EIO;
486 		break;
487 	case DID_ERROR:
488 		old_hdr->result = (srp->sense_b[0] == 0 &&
489 				  hp->masked_status == GOOD) ? 0 : EIO;
490 		break;
491 	default:
492 		old_hdr->result = EIO;
493 		break;
494 	}
495 
496 	/* Now copy the result back to the user buffer.  */
497 	if (count >= SZ_SG_HEADER) {
498 		if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
499 			retval = -EFAULT;
500 			goto free_old_hdr;
501 		}
502 		buf += SZ_SG_HEADER;
503 		if (count > old_hdr->reply_len)
504 			count = old_hdr->reply_len;
505 		if (count > SZ_SG_HEADER) {
506 			if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
507 				retval = -EFAULT;
508 				goto free_old_hdr;
509 			}
510 		}
511 	} else
512 		count = (old_hdr->result == 0) ? 0 : -EIO;
513 	sg_finish_rem_req(srp);
514 	retval = count;
515 free_old_hdr:
516 	kfree(old_hdr);
517 	return retval;
518 }
519 
520 static ssize_t
521 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
522 {
523 	sg_io_hdr_t *hp = &srp->header;
524 	int err = 0;
525 	int len;
526 
527 	if (count < SZ_SG_IO_HDR) {
528 		err = -EINVAL;
529 		goto err_out;
530 	}
531 	hp->sb_len_wr = 0;
532 	if ((hp->mx_sb_len > 0) && hp->sbp) {
533 		if ((CHECK_CONDITION & hp->masked_status) ||
534 		    (DRIVER_SENSE & hp->driver_status)) {
535 			int sb_len = SCSI_SENSE_BUFFERSIZE;
536 			sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
537 			len = 8 + (int) srp->sense_b[7];	/* Additional sense length field */
538 			len = (len > sb_len) ? sb_len : len;
539 			if (copy_to_user(hp->sbp, srp->sense_b, len)) {
540 				err = -EFAULT;
541 				goto err_out;
542 			}
543 			hp->sb_len_wr = len;
544 		}
545 	}
546 	if (hp->masked_status || hp->host_status || hp->driver_status)
547 		hp->info |= SG_INFO_CHECK;
548 	if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
549 		err = -EFAULT;
550 		goto err_out;
551 	}
552 err_out:
553 	err = sg_finish_rem_req(srp);
554 	return (0 == err) ? count : err;
555 }
556 
557 static ssize_t
558 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
559 {
560 	int mxsize, cmd_size, k;
561 	int input_size, blocking;
562 	unsigned char opcode;
563 	Sg_device *sdp;
564 	Sg_fd *sfp;
565 	Sg_request *srp;
566 	struct sg_header old_hdr;
567 	sg_io_hdr_t *hp;
568 	unsigned char cmnd[MAX_COMMAND_SIZE];
569 
570 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
571 		return -ENXIO;
572 	SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
573 				   sdp->disk->disk_name, (int) count));
574 	if (sdp->detached)
575 		return -ENODEV;
576 	if (!((filp->f_flags & O_NONBLOCK) ||
577 	      scsi_block_when_processing_errors(sdp->device)))
578 		return -ENXIO;
579 
580 	if (!access_ok(VERIFY_READ, buf, count))
581 		return -EFAULT;	/* protects following copy_from_user()s + get_user()s */
582 	if (count < SZ_SG_HEADER)
583 		return -EIO;
584 	if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
585 		return -EFAULT;
586 	blocking = !(filp->f_flags & O_NONBLOCK);
587 	if (old_hdr.reply_len < 0)
588 		return sg_new_write(sfp, filp, buf, count,
589 				    blocking, 0, 0, NULL);
590 	if (count < (SZ_SG_HEADER + 6))
591 		return -EIO;	/* The minimum scsi command length is 6 bytes. */
592 
593 	if (!(srp = sg_add_request(sfp))) {
594 		SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
595 		return -EDOM;
596 	}
597 	buf += SZ_SG_HEADER;
598 	__get_user(opcode, buf);
599 	if (sfp->next_cmd_len > 0) {
600 		if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
601 			SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
602 			sfp->next_cmd_len = 0;
603 			sg_remove_request(sfp, srp);
604 			return -EIO;
605 		}
606 		cmd_size = sfp->next_cmd_len;
607 		sfp->next_cmd_len = 0;	/* reset so only this write() effected */
608 	} else {
609 		cmd_size = COMMAND_SIZE(opcode);	/* based on SCSI command group */
610 		if ((opcode >= 0xc0) && old_hdr.twelve_byte)
611 			cmd_size = 12;
612 	}
613 	SCSI_LOG_TIMEOUT(4, printk(
614 		"sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
615 /* Determine buffer size.  */
616 	input_size = count - cmd_size;
617 	mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
618 	mxsize -= SZ_SG_HEADER;
619 	input_size -= SZ_SG_HEADER;
620 	if (input_size < 0) {
621 		sg_remove_request(sfp, srp);
622 		return -EIO;	/* User did not pass enough bytes for this command. */
623 	}
624 	hp = &srp->header;
625 	hp->interface_id = '\0';	/* indicator of old interface tunnelled */
626 	hp->cmd_len = (unsigned char) cmd_size;
627 	hp->iovec_count = 0;
628 	hp->mx_sb_len = 0;
629 	if (input_size > 0)
630 		hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
631 		    SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
632 	else
633 		hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
634 	hp->dxfer_len = mxsize;
635 	if (hp->dxfer_direction == SG_DXFER_TO_DEV)
636 		hp->dxferp = (char __user *)buf + cmd_size;
637 	else
638 		hp->dxferp = NULL;
639 	hp->sbp = NULL;
640 	hp->timeout = old_hdr.reply_len;	/* structure abuse ... */
641 	hp->flags = input_size;	/* structure abuse ... */
642 	hp->pack_id = old_hdr.pack_id;
643 	hp->usr_ptr = NULL;
644 	if (__copy_from_user(cmnd, buf, cmd_size))
645 		return -EFAULT;
646 	/*
647 	 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
648 	 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
649 	 * is a non-zero input_size, so emit a warning.
650 	 */
651 	if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
652 		static char cmd[TASK_COMM_LEN];
653 		if (strcmp(current->comm, cmd)) {
654 			printk_ratelimited(KERN_WARNING
655 					   "sg_write: data in/out %d/%d bytes "
656 					   "for SCSI command 0x%x-- guessing "
657 					   "data in;\n   program %s not setting "
658 					   "count and/or reply_len properly\n",
659 					   old_hdr.reply_len - (int)SZ_SG_HEADER,
660 					   input_size, (unsigned int) cmnd[0],
661 					   current->comm);
662 			strcpy(cmd, current->comm);
663 		}
664 	}
665 	k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
666 	return (k < 0) ? k : count;
667 }
668 
669 static ssize_t
670 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
671 		 size_t count, int blocking, int read_only, int sg_io_owned,
672 		 Sg_request **o_srp)
673 {
674 	int k;
675 	Sg_request *srp;
676 	sg_io_hdr_t *hp;
677 	unsigned char cmnd[MAX_COMMAND_SIZE];
678 	int timeout;
679 	unsigned long ul_timeout;
680 
681 	if (count < SZ_SG_IO_HDR)
682 		return -EINVAL;
683 	if (!access_ok(VERIFY_READ, buf, count))
684 		return -EFAULT; /* protects following copy_from_user()s + get_user()s */
685 
686 	sfp->cmd_q = 1;	/* when sg_io_hdr seen, set command queuing on */
687 	if (!(srp = sg_add_request(sfp))) {
688 		SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
689 		return -EDOM;
690 	}
691 	srp->sg_io_owned = sg_io_owned;
692 	hp = &srp->header;
693 	if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
694 		sg_remove_request(sfp, srp);
695 		return -EFAULT;
696 	}
697 	if (hp->interface_id != 'S') {
698 		sg_remove_request(sfp, srp);
699 		return -ENOSYS;
700 	}
701 	if (hp->flags & SG_FLAG_MMAP_IO) {
702 		if (hp->dxfer_len > sfp->reserve.bufflen) {
703 			sg_remove_request(sfp, srp);
704 			return -ENOMEM;	/* MMAP_IO size must fit in reserve buffer */
705 		}
706 		if (hp->flags & SG_FLAG_DIRECT_IO) {
707 			sg_remove_request(sfp, srp);
708 			return -EINVAL;	/* either MMAP_IO or DIRECT_IO (not both) */
709 		}
710 		if (sg_res_in_use(sfp)) {
711 			sg_remove_request(sfp, srp);
712 			return -EBUSY;	/* reserve buffer already being used */
713 		}
714 	}
715 	ul_timeout = msecs_to_jiffies(srp->header.timeout);
716 	timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
717 	if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
718 		sg_remove_request(sfp, srp);
719 		return -EMSGSIZE;
720 	}
721 	if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
722 		sg_remove_request(sfp, srp);
723 		return -EFAULT;	/* protects following copy_from_user()s + get_user()s */
724 	}
725 	if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
726 		sg_remove_request(sfp, srp);
727 		return -EFAULT;
728 	}
729 	if (read_only && sg_allow_access(file, cmnd)) {
730 		sg_remove_request(sfp, srp);
731 		return -EPERM;
732 	}
733 	k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
734 	if (k < 0)
735 		return k;
736 	if (o_srp)
737 		*o_srp = srp;
738 	return count;
739 }
740 
741 static int
742 sg_common_write(Sg_fd * sfp, Sg_request * srp,
743 		unsigned char *cmnd, int timeout, int blocking)
744 {
745 	int k, data_dir;
746 	Sg_device *sdp = sfp->parentdp;
747 	sg_io_hdr_t *hp = &srp->header;
748 
749 	srp->data.cmd_opcode = cmnd[0];	/* hold opcode of command */
750 	hp->status = 0;
751 	hp->masked_status = 0;
752 	hp->msg_status = 0;
753 	hp->info = 0;
754 	hp->host_status = 0;
755 	hp->driver_status = 0;
756 	hp->resid = 0;
757 	SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
758 			  (int) cmnd[0], (int) hp->cmd_len));
759 
760 	k = sg_start_req(srp, cmnd);
761 	if (k) {
762 		SCSI_LOG_TIMEOUT(1, printk("sg_common_write: start_req err=%d\n", k));
763 		sg_finish_rem_req(srp);
764 		return k;	/* probably out of space --> ENOMEM */
765 	}
766 	if (sdp->detached) {
767 		if (srp->bio)
768 			blk_end_request_all(srp->rq, -EIO);
769 		sg_finish_rem_req(srp);
770 		return -ENODEV;
771 	}
772 
773 	switch (hp->dxfer_direction) {
774 	case SG_DXFER_TO_FROM_DEV:
775 	case SG_DXFER_FROM_DEV:
776 		data_dir = DMA_FROM_DEVICE;
777 		break;
778 	case SG_DXFER_TO_DEV:
779 		data_dir = DMA_TO_DEVICE;
780 		break;
781 	case SG_DXFER_UNKNOWN:
782 		data_dir = DMA_BIDIRECTIONAL;
783 		break;
784 	default:
785 		data_dir = DMA_NONE;
786 		break;
787 	}
788 	hp->duration = jiffies_to_msecs(jiffies);
789 
790 	srp->rq->timeout = timeout;
791 	kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
792 	blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
793 			      srp->rq, 1, sg_rq_end_io);
794 	return 0;
795 }
796 
797 static int srp_done(Sg_fd *sfp, Sg_request *srp)
798 {
799 	unsigned long flags;
800 	int ret;
801 
802 	read_lock_irqsave(&sfp->rq_list_lock, flags);
803 	ret = srp->done;
804 	read_unlock_irqrestore(&sfp->rq_list_lock, flags);
805 	return ret;
806 }
807 
808 static long
809 sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
810 {
811 	void __user *p = (void __user *)arg;
812 	int __user *ip = p;
813 	int result, val, read_only;
814 	Sg_device *sdp;
815 	Sg_fd *sfp;
816 	Sg_request *srp;
817 	unsigned long iflags;
818 
819 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
820 		return -ENXIO;
821 
822 	SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
823 				   sdp->disk->disk_name, (int) cmd_in));
824 	read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
825 
826 	switch (cmd_in) {
827 	case SG_IO:
828 		if (sdp->detached)
829 			return -ENODEV;
830 		if (!scsi_block_when_processing_errors(sdp->device))
831 			return -ENXIO;
832 		if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
833 			return -EFAULT;
834 		result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
835 				 1, read_only, 1, &srp);
836 		if (result < 0)
837 			return result;
838 		result = wait_event_interruptible(sfp->read_wait,
839 			(srp_done(sfp, srp) || sdp->detached));
840 		if (sdp->detached)
841 			return -ENODEV;
842 		write_lock_irq(&sfp->rq_list_lock);
843 		if (srp->done) {
844 			srp->done = 2;
845 			write_unlock_irq(&sfp->rq_list_lock);
846 			result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
847 			return (result < 0) ? result : 0;
848 		}
849 		srp->orphan = 1;
850 		write_unlock_irq(&sfp->rq_list_lock);
851 		return result;	/* -ERESTARTSYS because signal hit process */
852 	case SG_SET_TIMEOUT:
853 		result = get_user(val, ip);
854 		if (result)
855 			return result;
856 		if (val < 0)
857 			return -EIO;
858 		if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
859 		    val = MULDIV (INT_MAX, USER_HZ, HZ);
860 		sfp->timeout_user = val;
861 		sfp->timeout = MULDIV (val, HZ, USER_HZ);
862 
863 		return 0;
864 	case SG_GET_TIMEOUT:	/* N.B. User receives timeout as return value */
865 				/* strange ..., for backward compatibility */
866 		return sfp->timeout_user;
867 	case SG_SET_FORCE_LOW_DMA:
868 		result = get_user(val, ip);
869 		if (result)
870 			return result;
871 		if (val) {
872 			sfp->low_dma = 1;
873 			if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
874 				val = (int) sfp->reserve.bufflen;
875 				sg_remove_scat(&sfp->reserve);
876 				sg_build_reserve(sfp, val);
877 			}
878 		} else {
879 			if (sdp->detached)
880 				return -ENODEV;
881 			sfp->low_dma = sdp->device->host->unchecked_isa_dma;
882 		}
883 		return 0;
884 	case SG_GET_LOW_DMA:
885 		return put_user((int) sfp->low_dma, ip);
886 	case SG_GET_SCSI_ID:
887 		if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
888 			return -EFAULT;
889 		else {
890 			sg_scsi_id_t __user *sg_idp = p;
891 
892 			if (sdp->detached)
893 				return -ENODEV;
894 			__put_user((int) sdp->device->host->host_no,
895 				   &sg_idp->host_no);
896 			__put_user((int) sdp->device->channel,
897 				   &sg_idp->channel);
898 			__put_user((int) sdp->device->id, &sg_idp->scsi_id);
899 			__put_user((int) sdp->device->lun, &sg_idp->lun);
900 			__put_user((int) sdp->device->type, &sg_idp->scsi_type);
901 			__put_user((short) sdp->device->host->cmd_per_lun,
902 				   &sg_idp->h_cmd_per_lun);
903 			__put_user((short) sdp->device->queue_depth,
904 				   &sg_idp->d_queue_depth);
905 			__put_user(0, &sg_idp->unused[0]);
906 			__put_user(0, &sg_idp->unused[1]);
907 			return 0;
908 		}
909 	case SG_SET_FORCE_PACK_ID:
910 		result = get_user(val, ip);
911 		if (result)
912 			return result;
913 		sfp->force_packid = val ? 1 : 0;
914 		return 0;
915 	case SG_GET_PACK_ID:
916 		if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
917 			return -EFAULT;
918 		read_lock_irqsave(&sfp->rq_list_lock, iflags);
919 		for (srp = sfp->headrp; srp; srp = srp->nextrp) {
920 			if ((1 == srp->done) && (!srp->sg_io_owned)) {
921 				read_unlock_irqrestore(&sfp->rq_list_lock,
922 						       iflags);
923 				__put_user(srp->header.pack_id, ip);
924 				return 0;
925 			}
926 		}
927 		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
928 		__put_user(-1, ip);
929 		return 0;
930 	case SG_GET_NUM_WAITING:
931 		read_lock_irqsave(&sfp->rq_list_lock, iflags);
932 		for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
933 			if ((1 == srp->done) && (!srp->sg_io_owned))
934 				++val;
935 		}
936 		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
937 		return put_user(val, ip);
938 	case SG_GET_SG_TABLESIZE:
939 		return put_user(sdp->sg_tablesize, ip);
940 	case SG_SET_RESERVED_SIZE:
941 		result = get_user(val, ip);
942 		if (result)
943 			return result;
944                 if (val < 0)
945                         return -EINVAL;
946 		val = min_t(int, val,
947 			    queue_max_sectors(sdp->device->request_queue) * 512);
948 		if (val != sfp->reserve.bufflen) {
949 			if (sg_res_in_use(sfp) || sfp->mmap_called)
950 				return -EBUSY;
951 			sg_remove_scat(&sfp->reserve);
952 			sg_build_reserve(sfp, val);
953 		}
954 		return 0;
955 	case SG_GET_RESERVED_SIZE:
956 		val = min_t(int, sfp->reserve.bufflen,
957 			    queue_max_sectors(sdp->device->request_queue) * 512);
958 		return put_user(val, ip);
959 	case SG_SET_COMMAND_Q:
960 		result = get_user(val, ip);
961 		if (result)
962 			return result;
963 		sfp->cmd_q = val ? 1 : 0;
964 		return 0;
965 	case SG_GET_COMMAND_Q:
966 		return put_user((int) sfp->cmd_q, ip);
967 	case SG_SET_KEEP_ORPHAN:
968 		result = get_user(val, ip);
969 		if (result)
970 			return result;
971 		sfp->keep_orphan = val;
972 		return 0;
973 	case SG_GET_KEEP_ORPHAN:
974 		return put_user((int) sfp->keep_orphan, ip);
975 	case SG_NEXT_CMD_LEN:
976 		result = get_user(val, ip);
977 		if (result)
978 			return result;
979 		sfp->next_cmd_len = (val > 0) ? val : 0;
980 		return 0;
981 	case SG_GET_VERSION_NUM:
982 		return put_user(sg_version_num, ip);
983 	case SG_GET_ACCESS_COUNT:
984 		/* faked - we don't have a real access count anymore */
985 		val = (sdp->device ? 1 : 0);
986 		return put_user(val, ip);
987 	case SG_GET_REQUEST_TABLE:
988 		if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
989 			return -EFAULT;
990 		else {
991 			sg_req_info_t *rinfo;
992 			unsigned int ms;
993 
994 			rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
995 								GFP_KERNEL);
996 			if (!rinfo)
997 				return -ENOMEM;
998 			read_lock_irqsave(&sfp->rq_list_lock, iflags);
999 			for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
1000 			     ++val, srp = srp ? srp->nextrp : srp) {
1001 				memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
1002 				if (srp) {
1003 					rinfo[val].req_state = srp->done + 1;
1004 					rinfo[val].problem =
1005 					    srp->header.masked_status &
1006 					    srp->header.host_status &
1007 					    srp->header.driver_status;
1008 					if (srp->done)
1009 						rinfo[val].duration =
1010 							srp->header.duration;
1011 					else {
1012 						ms = jiffies_to_msecs(jiffies);
1013 						rinfo[val].duration =
1014 						    (ms > srp->header.duration) ?
1015 						    (ms - srp->header.duration) : 0;
1016 					}
1017 					rinfo[val].orphan = srp->orphan;
1018 					rinfo[val].sg_io_owned =
1019 							srp->sg_io_owned;
1020 					rinfo[val].pack_id =
1021 							srp->header.pack_id;
1022 					rinfo[val].usr_ptr =
1023 							srp->header.usr_ptr;
1024 				}
1025 			}
1026 			read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1027 			result = __copy_to_user(p, rinfo,
1028 						SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1029 			result = result ? -EFAULT : 0;
1030 			kfree(rinfo);
1031 			return result;
1032 		}
1033 	case SG_EMULATED_HOST:
1034 		if (sdp->detached)
1035 			return -ENODEV;
1036 		return put_user(sdp->device->host->hostt->emulated, ip);
1037 	case SG_SCSI_RESET:
1038 		if (sdp->detached)
1039 			return -ENODEV;
1040 		if (filp->f_flags & O_NONBLOCK) {
1041 			if (scsi_host_in_recovery(sdp->device->host))
1042 				return -EBUSY;
1043 		} else if (!scsi_block_when_processing_errors(sdp->device))
1044 			return -EBUSY;
1045 		result = get_user(val, ip);
1046 		if (result)
1047 			return result;
1048 		if (SG_SCSI_RESET_NOTHING == val)
1049 			return 0;
1050 		switch (val) {
1051 		case SG_SCSI_RESET_DEVICE:
1052 			val = SCSI_TRY_RESET_DEVICE;
1053 			break;
1054 		case SG_SCSI_RESET_TARGET:
1055 			val = SCSI_TRY_RESET_TARGET;
1056 			break;
1057 		case SG_SCSI_RESET_BUS:
1058 			val = SCSI_TRY_RESET_BUS;
1059 			break;
1060 		case SG_SCSI_RESET_HOST:
1061 			val = SCSI_TRY_RESET_HOST;
1062 			break;
1063 		default:
1064 			return -EINVAL;
1065 		}
1066 		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1067 			return -EACCES;
1068 		return (scsi_reset_provider(sdp->device, val) ==
1069 			SUCCESS) ? 0 : -EIO;
1070 	case SCSI_IOCTL_SEND_COMMAND:
1071 		if (sdp->detached)
1072 			return -ENODEV;
1073 		if (read_only) {
1074 			unsigned char opcode = WRITE_6;
1075 			Scsi_Ioctl_Command __user *siocp = p;
1076 
1077 			if (copy_from_user(&opcode, siocp->data, 1))
1078 				return -EFAULT;
1079 			if (sg_allow_access(filp, &opcode))
1080 				return -EPERM;
1081 		}
1082 		return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1083 	case SG_SET_DEBUG:
1084 		result = get_user(val, ip);
1085 		if (result)
1086 			return result;
1087 		sdp->sgdebug = (char) val;
1088 		return 0;
1089 	case SCSI_IOCTL_GET_IDLUN:
1090 	case SCSI_IOCTL_GET_BUS_NUMBER:
1091 	case SCSI_IOCTL_PROBE_HOST:
1092 	case SG_GET_TRANSFORM:
1093 		if (sdp->detached)
1094 			return -ENODEV;
1095 		return scsi_ioctl(sdp->device, cmd_in, p);
1096 	case BLKSECTGET:
1097 		return put_user(queue_max_sectors(sdp->device->request_queue) * 512,
1098 				ip);
1099 	case BLKTRACESETUP:
1100 		return blk_trace_setup(sdp->device->request_queue,
1101 				       sdp->disk->disk_name,
1102 				       MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1103 				       NULL,
1104 				       (char *)arg);
1105 	case BLKTRACESTART:
1106 		return blk_trace_startstop(sdp->device->request_queue, 1);
1107 	case BLKTRACESTOP:
1108 		return blk_trace_startstop(sdp->device->request_queue, 0);
1109 	case BLKTRACETEARDOWN:
1110 		return blk_trace_remove(sdp->device->request_queue);
1111 	default:
1112 		if (read_only)
1113 			return -EPERM;	/* don't know so take safe approach */
1114 		return scsi_ioctl(sdp->device, cmd_in, p);
1115 	}
1116 }
1117 
1118 #ifdef CONFIG_COMPAT
1119 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1120 {
1121 	Sg_device *sdp;
1122 	Sg_fd *sfp;
1123 	struct scsi_device *sdev;
1124 
1125 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1126 		return -ENXIO;
1127 
1128 	sdev = sdp->device;
1129 	if (sdev->host->hostt->compat_ioctl) {
1130 		int ret;
1131 
1132 		ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1133 
1134 		return ret;
1135 	}
1136 
1137 	return -ENOIOCTLCMD;
1138 }
1139 #endif
1140 
1141 static unsigned int
1142 sg_poll(struct file *filp, poll_table * wait)
1143 {
1144 	unsigned int res = 0;
1145 	Sg_device *sdp;
1146 	Sg_fd *sfp;
1147 	Sg_request *srp;
1148 	int count = 0;
1149 	unsigned long iflags;
1150 
1151 	sfp = filp->private_data;
1152 	if (!sfp)
1153 		return POLLERR;
1154 	sdp = sfp->parentdp;
1155 	if (!sdp)
1156 		return POLLERR;
1157 	poll_wait(filp, &sfp->read_wait, wait);
1158 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
1159 	for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1160 		/* if any read waiting, flag it */
1161 		if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1162 			res = POLLIN | POLLRDNORM;
1163 		++count;
1164 	}
1165 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1166 
1167 	if (sdp->detached)
1168 		res |= POLLHUP;
1169 	else if (!sfp->cmd_q) {
1170 		if (0 == count)
1171 			res |= POLLOUT | POLLWRNORM;
1172 	} else if (count < SG_MAX_QUEUE)
1173 		res |= POLLOUT | POLLWRNORM;
1174 	SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1175 				   sdp->disk->disk_name, (int) res));
1176 	return res;
1177 }
1178 
1179 static int
1180 sg_fasync(int fd, struct file *filp, int mode)
1181 {
1182 	Sg_device *sdp;
1183 	Sg_fd *sfp;
1184 
1185 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1186 		return -ENXIO;
1187 	SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1188 				   sdp->disk->disk_name, mode));
1189 
1190 	return fasync_helper(fd, filp, mode, &sfp->async_qp);
1191 }
1192 
1193 static int
1194 sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1195 {
1196 	Sg_fd *sfp;
1197 	unsigned long offset, len, sa;
1198 	Sg_scatter_hold *rsv_schp;
1199 	int k, length;
1200 
1201 	if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1202 		return VM_FAULT_SIGBUS;
1203 	rsv_schp = &sfp->reserve;
1204 	offset = vmf->pgoff << PAGE_SHIFT;
1205 	if (offset >= rsv_schp->bufflen)
1206 		return VM_FAULT_SIGBUS;
1207 	SCSI_LOG_TIMEOUT(3, printk("sg_vma_fault: offset=%lu, scatg=%d\n",
1208 				   offset, rsv_schp->k_use_sg));
1209 	sa = vma->vm_start;
1210 	length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1211 	for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1212 		len = vma->vm_end - sa;
1213 		len = (len < length) ? len : length;
1214 		if (offset < len) {
1215 			struct page *page = nth_page(rsv_schp->pages[k],
1216 						     offset >> PAGE_SHIFT);
1217 			get_page(page);	/* increment page count */
1218 			vmf->page = page;
1219 			return 0; /* success */
1220 		}
1221 		sa += len;
1222 		offset -= len;
1223 	}
1224 
1225 	return VM_FAULT_SIGBUS;
1226 }
1227 
1228 static const struct vm_operations_struct sg_mmap_vm_ops = {
1229 	.fault = sg_vma_fault,
1230 };
1231 
1232 static int
1233 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1234 {
1235 	Sg_fd *sfp;
1236 	unsigned long req_sz, len, sa;
1237 	Sg_scatter_hold *rsv_schp;
1238 	int k, length;
1239 
1240 	if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1241 		return -ENXIO;
1242 	req_sz = vma->vm_end - vma->vm_start;
1243 	SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1244 				   (void *) vma->vm_start, (int) req_sz));
1245 	if (vma->vm_pgoff)
1246 		return -EINVAL;	/* want no offset */
1247 	rsv_schp = &sfp->reserve;
1248 	if (req_sz > rsv_schp->bufflen)
1249 		return -ENOMEM;	/* cannot map more than reserved buffer */
1250 
1251 	sa = vma->vm_start;
1252 	length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1253 	for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1254 		len = vma->vm_end - sa;
1255 		len = (len < length) ? len : length;
1256 		sa += len;
1257 	}
1258 
1259 	sfp->mmap_called = 1;
1260 	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
1261 	vma->vm_private_data = sfp;
1262 	vma->vm_ops = &sg_mmap_vm_ops;
1263 	return 0;
1264 }
1265 
1266 static void sg_rq_end_io_usercontext(struct work_struct *work)
1267 {
1268 	struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1269 	struct sg_fd *sfp = srp->parentfp;
1270 
1271 	sg_finish_rem_req(srp);
1272 	kref_put(&sfp->f_ref, sg_remove_sfp);
1273 }
1274 
1275 /*
1276  * This function is a "bottom half" handler that is called by the mid
1277  * level when a command is completed (or has failed).
1278  */
1279 static void sg_rq_end_io(struct request *rq, int uptodate)
1280 {
1281 	struct sg_request *srp = rq->end_io_data;
1282 	Sg_device *sdp;
1283 	Sg_fd *sfp;
1284 	unsigned long iflags;
1285 	unsigned int ms;
1286 	char *sense;
1287 	int result, resid, done = 1;
1288 
1289 	if (WARN_ON(srp->done != 0))
1290 		return;
1291 
1292 	sfp = srp->parentfp;
1293 	if (WARN_ON(sfp == NULL))
1294 		return;
1295 
1296 	sdp = sfp->parentdp;
1297 	if (unlikely(sdp->detached))
1298 		printk(KERN_INFO "sg_rq_end_io: device detached\n");
1299 
1300 	sense = rq->sense;
1301 	result = rq->errors;
1302 	resid = rq->resid_len;
1303 
1304 	SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1305 		sdp->disk->disk_name, srp->header.pack_id, result));
1306 	srp->header.resid = resid;
1307 	ms = jiffies_to_msecs(jiffies);
1308 	srp->header.duration = (ms > srp->header.duration) ?
1309 				(ms - srp->header.duration) : 0;
1310 	if (0 != result) {
1311 		struct scsi_sense_hdr sshdr;
1312 
1313 		srp->header.status = 0xff & result;
1314 		srp->header.masked_status = status_byte(result);
1315 		srp->header.msg_status = msg_byte(result);
1316 		srp->header.host_status = host_byte(result);
1317 		srp->header.driver_status = driver_byte(result);
1318 		if ((sdp->sgdebug > 0) &&
1319 		    ((CHECK_CONDITION == srp->header.masked_status) ||
1320 		     (COMMAND_TERMINATED == srp->header.masked_status)))
1321 			__scsi_print_sense("sg_cmd_done", sense,
1322 					   SCSI_SENSE_BUFFERSIZE);
1323 
1324 		/* Following if statement is a patch supplied by Eric Youngdale */
1325 		if (driver_byte(result) != 0
1326 		    && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1327 		    && !scsi_sense_is_deferred(&sshdr)
1328 		    && sshdr.sense_key == UNIT_ATTENTION
1329 		    && sdp->device->removable) {
1330 			/* Detected possible disc change. Set the bit - this */
1331 			/* may be used if there are filesystems using this device */
1332 			sdp->device->changed = 1;
1333 		}
1334 	}
1335 	/* Rely on write phase to clean out srp status values, so no "else" */
1336 
1337 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
1338 	if (unlikely(srp->orphan)) {
1339 		if (sfp->keep_orphan)
1340 			srp->sg_io_owned = 0;
1341 		else
1342 			done = 0;
1343 	}
1344 	srp->done = done;
1345 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1346 
1347 	if (likely(done)) {
1348 		/* Now wake up any sg_read() that is waiting for this
1349 		 * packet.
1350 		 */
1351 		wake_up_interruptible(&sfp->read_wait);
1352 		kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1353 		kref_put(&sfp->f_ref, sg_remove_sfp);
1354 	} else {
1355 		INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1356 		schedule_work(&srp->ew.work);
1357 	}
1358 }
1359 
1360 static const struct file_operations sg_fops = {
1361 	.owner = THIS_MODULE,
1362 	.read = sg_read,
1363 	.write = sg_write,
1364 	.poll = sg_poll,
1365 	.unlocked_ioctl = sg_ioctl,
1366 #ifdef CONFIG_COMPAT
1367 	.compat_ioctl = sg_compat_ioctl,
1368 #endif
1369 	.open = sg_open,
1370 	.mmap = sg_mmap,
1371 	.release = sg_release,
1372 	.fasync = sg_fasync,
1373 	.llseek = no_llseek,
1374 };
1375 
1376 static struct class *sg_sysfs_class;
1377 
1378 static int sg_sysfs_valid = 0;
1379 
1380 static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1381 {
1382 	struct request_queue *q = scsidp->request_queue;
1383 	Sg_device *sdp;
1384 	unsigned long iflags;
1385 	int error;
1386 	u32 k;
1387 
1388 	sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1389 	if (!sdp) {
1390 		printk(KERN_WARNING "kmalloc Sg_device failure\n");
1391 		return ERR_PTR(-ENOMEM);
1392 	}
1393 
1394 	idr_preload(GFP_KERNEL);
1395 	write_lock_irqsave(&sg_index_lock, iflags);
1396 
1397 	error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1398 	if (error < 0) {
1399 		if (error == -ENOSPC) {
1400 			sdev_printk(KERN_WARNING, scsidp,
1401 				    "Unable to attach sg device type=%d, minor number exceeds %d\n",
1402 				    scsidp->type, SG_MAX_DEVS - 1);
1403 			error = -ENODEV;
1404 		} else {
1405 			printk(KERN_WARNING
1406 			       "idr allocation Sg_device failure: %d\n", error);
1407 		}
1408 		goto out_unlock;
1409 	}
1410 	k = error;
1411 
1412 	SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1413 	sprintf(disk->disk_name, "sg%d", k);
1414 	disk->first_minor = k;
1415 	sdp->disk = disk;
1416 	sdp->device = scsidp;
1417 	INIT_LIST_HEAD(&sdp->sfds);
1418 	init_waitqueue_head(&sdp->o_excl_wait);
1419 	sdp->sg_tablesize = queue_max_segments(q);
1420 	sdp->index = k;
1421 	kref_init(&sdp->d_ref);
1422 	error = 0;
1423 
1424 out_unlock:
1425 	write_unlock_irqrestore(&sg_index_lock, iflags);
1426 	idr_preload_end();
1427 
1428 	if (error) {
1429 		kfree(sdp);
1430 		return ERR_PTR(error);
1431 	}
1432 	return sdp;
1433 }
1434 
1435 static int
1436 sg_add(struct device *cl_dev, struct class_interface *cl_intf)
1437 {
1438 	struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1439 	struct gendisk *disk;
1440 	Sg_device *sdp = NULL;
1441 	struct cdev * cdev = NULL;
1442 	int error;
1443 	unsigned long iflags;
1444 
1445 	disk = alloc_disk(1);
1446 	if (!disk) {
1447 		printk(KERN_WARNING "alloc_disk failed\n");
1448 		return -ENOMEM;
1449 	}
1450 	disk->major = SCSI_GENERIC_MAJOR;
1451 
1452 	error = -ENOMEM;
1453 	cdev = cdev_alloc();
1454 	if (!cdev) {
1455 		printk(KERN_WARNING "cdev_alloc failed\n");
1456 		goto out;
1457 	}
1458 	cdev->owner = THIS_MODULE;
1459 	cdev->ops = &sg_fops;
1460 
1461 	sdp = sg_alloc(disk, scsidp);
1462 	if (IS_ERR(sdp)) {
1463 		printk(KERN_WARNING "sg_alloc failed\n");
1464 		error = PTR_ERR(sdp);
1465 		goto out;
1466 	}
1467 
1468 	error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1469 	if (error)
1470 		goto cdev_add_err;
1471 
1472 	sdp->cdev = cdev;
1473 	if (sg_sysfs_valid) {
1474 		struct device *sg_class_member;
1475 
1476 		sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1477 						MKDEV(SCSI_GENERIC_MAJOR,
1478 						      sdp->index),
1479 						sdp, "%s", disk->disk_name);
1480 		if (IS_ERR(sg_class_member)) {
1481 			printk(KERN_ERR "sg_add: "
1482 			       "device_create failed\n");
1483 			error = PTR_ERR(sg_class_member);
1484 			goto cdev_add_err;
1485 		}
1486 		error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1487 					  &sg_class_member->kobj, "generic");
1488 		if (error)
1489 			printk(KERN_ERR "sg_add: unable to make symlink "
1490 					"'generic' back to sg%d\n", sdp->index);
1491 	} else
1492 		printk(KERN_WARNING "sg_add: sg_sys Invalid\n");
1493 
1494 	sdev_printk(KERN_NOTICE, scsidp,
1495 		    "Attached scsi generic sg%d type %d\n", sdp->index,
1496 		    scsidp->type);
1497 
1498 	dev_set_drvdata(cl_dev, sdp);
1499 
1500 	return 0;
1501 
1502 cdev_add_err:
1503 	write_lock_irqsave(&sg_index_lock, iflags);
1504 	idr_remove(&sg_index_idr, sdp->index);
1505 	write_unlock_irqrestore(&sg_index_lock, iflags);
1506 	kfree(sdp);
1507 
1508 out:
1509 	put_disk(disk);
1510 	if (cdev)
1511 		cdev_del(cdev);
1512 	return error;
1513 }
1514 
1515 static void sg_device_destroy(struct kref *kref)
1516 {
1517 	struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1518 	unsigned long flags;
1519 
1520 	/* CAUTION!  Note that the device can still be found via idr_find()
1521 	 * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1522 	 * any other cleanup.
1523 	 */
1524 
1525 	write_lock_irqsave(&sg_index_lock, flags);
1526 	idr_remove(&sg_index_idr, sdp->index);
1527 	write_unlock_irqrestore(&sg_index_lock, flags);
1528 
1529 	SCSI_LOG_TIMEOUT(3,
1530 		printk("sg_device_destroy: %s\n",
1531 			sdp->disk->disk_name));
1532 
1533 	put_disk(sdp->disk);
1534 	kfree(sdp);
1535 }
1536 
1537 static void sg_remove(struct device *cl_dev, struct class_interface *cl_intf)
1538 {
1539 	struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1540 	Sg_device *sdp = dev_get_drvdata(cl_dev);
1541 	unsigned long iflags;
1542 	Sg_fd *sfp;
1543 
1544 	if (!sdp || sdp->detached)
1545 		return;
1546 
1547 	SCSI_LOG_TIMEOUT(3, printk("sg_remove: %s\n", sdp->disk->disk_name));
1548 
1549 	/* Need a write lock to set sdp->detached. */
1550 	write_lock_irqsave(&sg_index_lock, iflags);
1551 	sdp->detached = 1;
1552 	list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1553 		wake_up_interruptible(&sfp->read_wait);
1554 		kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1555 	}
1556 	write_unlock_irqrestore(&sg_index_lock, iflags);
1557 
1558 	sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1559 	device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1560 	cdev_del(sdp->cdev);
1561 	sdp->cdev = NULL;
1562 
1563 	sg_put_dev(sdp);
1564 }
1565 
1566 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1567 module_param_named(def_reserved_size, def_reserved_size, int,
1568 		   S_IRUGO | S_IWUSR);
1569 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1570 
1571 MODULE_AUTHOR("Douglas Gilbert");
1572 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1573 MODULE_LICENSE("GPL");
1574 MODULE_VERSION(SG_VERSION_STR);
1575 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1576 
1577 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1578                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1579 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1580 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1581 
1582 static int __init
1583 init_sg(void)
1584 {
1585 	int rc;
1586 
1587 	if (scatter_elem_sz < PAGE_SIZE) {
1588 		scatter_elem_sz = PAGE_SIZE;
1589 		scatter_elem_sz_prev = scatter_elem_sz;
1590 	}
1591 	if (def_reserved_size >= 0)
1592 		sg_big_buff = def_reserved_size;
1593 	else
1594 		def_reserved_size = sg_big_buff;
1595 
1596 	rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1597 				    SG_MAX_DEVS, "sg");
1598 	if (rc)
1599 		return rc;
1600         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1601         if ( IS_ERR(sg_sysfs_class) ) {
1602 		rc = PTR_ERR(sg_sysfs_class);
1603 		goto err_out;
1604         }
1605 	sg_sysfs_valid = 1;
1606 	rc = scsi_register_interface(&sg_interface);
1607 	if (0 == rc) {
1608 #ifdef CONFIG_SCSI_PROC_FS
1609 		sg_proc_init();
1610 #endif				/* CONFIG_SCSI_PROC_FS */
1611 		return 0;
1612 	}
1613 	class_destroy(sg_sysfs_class);
1614 err_out:
1615 	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1616 	return rc;
1617 }
1618 
1619 static void __exit
1620 exit_sg(void)
1621 {
1622 #ifdef CONFIG_SCSI_PROC_FS
1623 	sg_proc_cleanup();
1624 #endif				/* CONFIG_SCSI_PROC_FS */
1625 	scsi_unregister_interface(&sg_interface);
1626 	class_destroy(sg_sysfs_class);
1627 	sg_sysfs_valid = 0;
1628 	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1629 				 SG_MAX_DEVS);
1630 	idr_destroy(&sg_index_idr);
1631 }
1632 
1633 static int sg_start_req(Sg_request *srp, unsigned char *cmd)
1634 {
1635 	int res;
1636 	struct request *rq;
1637 	Sg_fd *sfp = srp->parentfp;
1638 	sg_io_hdr_t *hp = &srp->header;
1639 	int dxfer_len = (int) hp->dxfer_len;
1640 	int dxfer_dir = hp->dxfer_direction;
1641 	unsigned int iov_count = hp->iovec_count;
1642 	Sg_scatter_hold *req_schp = &srp->data;
1643 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
1644 	struct request_queue *q = sfp->parentdp->device->request_queue;
1645 	struct rq_map_data *md, map_data;
1646 	int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1647 
1648 	SCSI_LOG_TIMEOUT(4, printk(KERN_INFO "sg_start_req: dxfer_len=%d\n",
1649 				   dxfer_len));
1650 
1651 	rq = blk_get_request(q, rw, GFP_ATOMIC);
1652 	if (!rq)
1653 		return -ENOMEM;
1654 
1655 	memcpy(rq->cmd, cmd, hp->cmd_len);
1656 
1657 	rq->cmd_len = hp->cmd_len;
1658 	rq->cmd_type = REQ_TYPE_BLOCK_PC;
1659 
1660 	srp->rq = rq;
1661 	rq->end_io_data = srp;
1662 	rq->sense = srp->sense_b;
1663 	rq->retries = SG_DEFAULT_RETRIES;
1664 
1665 	if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1666 		return 0;
1667 
1668 	if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1669 	    dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1670 	    !sfp->parentdp->device->host->unchecked_isa_dma &&
1671 	    blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1672 		md = NULL;
1673 	else
1674 		md = &map_data;
1675 
1676 	if (md) {
1677 		if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen)
1678 			sg_link_reserve(sfp, srp, dxfer_len);
1679 		else {
1680 			res = sg_build_indirect(req_schp, sfp, dxfer_len);
1681 			if (res)
1682 				return res;
1683 		}
1684 
1685 		md->pages = req_schp->pages;
1686 		md->page_order = req_schp->page_order;
1687 		md->nr_entries = req_schp->k_use_sg;
1688 		md->offset = 0;
1689 		md->null_mapped = hp->dxferp ? 0 : 1;
1690 		if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1691 			md->from_user = 1;
1692 		else
1693 			md->from_user = 0;
1694 	}
1695 
1696 	if (iov_count) {
1697 		int len, size = sizeof(struct sg_iovec) * iov_count;
1698 		struct iovec *iov;
1699 
1700 		iov = memdup_user(hp->dxferp, size);
1701 		if (IS_ERR(iov))
1702 			return PTR_ERR(iov);
1703 
1704 		len = iov_length(iov, iov_count);
1705 		if (hp->dxfer_len < len) {
1706 			iov_count = iov_shorten(iov, iov_count, hp->dxfer_len);
1707 			len = hp->dxfer_len;
1708 		}
1709 
1710 		res = blk_rq_map_user_iov(q, rq, md, (struct sg_iovec *)iov,
1711 					  iov_count,
1712 					  len, GFP_ATOMIC);
1713 		kfree(iov);
1714 	} else
1715 		res = blk_rq_map_user(q, rq, md, hp->dxferp,
1716 				      hp->dxfer_len, GFP_ATOMIC);
1717 
1718 	if (!res) {
1719 		srp->bio = rq->bio;
1720 
1721 		if (!md) {
1722 			req_schp->dio_in_use = 1;
1723 			hp->info |= SG_INFO_DIRECT_IO;
1724 		}
1725 	}
1726 	return res;
1727 }
1728 
1729 static int sg_finish_rem_req(Sg_request * srp)
1730 {
1731 	int ret = 0;
1732 
1733 	Sg_fd *sfp = srp->parentfp;
1734 	Sg_scatter_hold *req_schp = &srp->data;
1735 
1736 	SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1737 	if (srp->rq) {
1738 		if (srp->bio)
1739 			ret = blk_rq_unmap_user(srp->bio);
1740 
1741 		blk_put_request(srp->rq);
1742 	}
1743 
1744 	if (srp->res_used)
1745 		sg_unlink_reserve(sfp, srp);
1746 	else
1747 		sg_remove_scat(req_schp);
1748 
1749 	sg_remove_request(sfp, srp);
1750 
1751 	return ret;
1752 }
1753 
1754 static int
1755 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1756 {
1757 	int sg_bufflen = tablesize * sizeof(struct page *);
1758 	gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1759 
1760 	schp->pages = kzalloc(sg_bufflen, gfp_flags);
1761 	if (!schp->pages)
1762 		return -ENOMEM;
1763 	schp->sglist_len = sg_bufflen;
1764 	return tablesize;	/* number of scat_gath elements allocated */
1765 }
1766 
1767 static int
1768 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1769 {
1770 	int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1771 	int sg_tablesize = sfp->parentdp->sg_tablesize;
1772 	int blk_size = buff_size, order;
1773 	gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1774 
1775 	if (blk_size < 0)
1776 		return -EFAULT;
1777 	if (0 == blk_size)
1778 		++blk_size;	/* don't know why */
1779 	/* round request up to next highest SG_SECTOR_SZ byte boundary */
1780 	blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1781 	SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1782 				   buff_size, blk_size));
1783 
1784 	/* N.B. ret_sz carried into this block ... */
1785 	mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1786 	if (mx_sc_elems < 0)
1787 		return mx_sc_elems;	/* most likely -ENOMEM */
1788 
1789 	num = scatter_elem_sz;
1790 	if (unlikely(num != scatter_elem_sz_prev)) {
1791 		if (num < PAGE_SIZE) {
1792 			scatter_elem_sz = PAGE_SIZE;
1793 			scatter_elem_sz_prev = PAGE_SIZE;
1794 		} else
1795 			scatter_elem_sz_prev = num;
1796 	}
1797 
1798 	if (sfp->low_dma)
1799 		gfp_mask |= GFP_DMA;
1800 
1801 	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1802 		gfp_mask |= __GFP_ZERO;
1803 
1804 	order = get_order(num);
1805 retry:
1806 	ret_sz = 1 << (PAGE_SHIFT + order);
1807 
1808 	for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1809 	     k++, rem_sz -= ret_sz) {
1810 
1811 		num = (rem_sz > scatter_elem_sz_prev) ?
1812 			scatter_elem_sz_prev : rem_sz;
1813 
1814 		schp->pages[k] = alloc_pages(gfp_mask, order);
1815 		if (!schp->pages[k])
1816 			goto out;
1817 
1818 		if (num == scatter_elem_sz_prev) {
1819 			if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1820 				scatter_elem_sz = ret_sz;
1821 				scatter_elem_sz_prev = ret_sz;
1822 			}
1823 		}
1824 
1825 		SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k=%d, num=%d, "
1826 				 "ret_sz=%d\n", k, num, ret_sz));
1827 	}		/* end of for loop */
1828 
1829 	schp->page_order = order;
1830 	schp->k_use_sg = k;
1831 	SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, "
1832 			 "rem_sz=%d\n", k, rem_sz));
1833 
1834 	schp->bufflen = blk_size;
1835 	if (rem_sz > 0)	/* must have failed */
1836 		return -ENOMEM;
1837 	return 0;
1838 out:
1839 	for (i = 0; i < k; i++)
1840 		__free_pages(schp->pages[i], order);
1841 
1842 	if (--order >= 0)
1843 		goto retry;
1844 
1845 	return -ENOMEM;
1846 }
1847 
1848 static void
1849 sg_remove_scat(Sg_scatter_hold * schp)
1850 {
1851 	SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1852 	if (schp->pages && schp->sglist_len > 0) {
1853 		if (!schp->dio_in_use) {
1854 			int k;
1855 
1856 			for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1857 				SCSI_LOG_TIMEOUT(5, printk(
1858 				    "sg_remove_scat: k=%d, pg=0x%p\n",
1859 				    k, schp->pages[k]));
1860 				__free_pages(schp->pages[k], schp->page_order);
1861 			}
1862 
1863 			kfree(schp->pages);
1864 		}
1865 	}
1866 	memset(schp, 0, sizeof (*schp));
1867 }
1868 
1869 static int
1870 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1871 {
1872 	Sg_scatter_hold *schp = &srp->data;
1873 	int k, num;
1874 
1875 	SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
1876 				   num_read_xfer));
1877 	if ((!outp) || (num_read_xfer <= 0))
1878 		return 0;
1879 
1880 	num = 1 << (PAGE_SHIFT + schp->page_order);
1881 	for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1882 		if (num > num_read_xfer) {
1883 			if (__copy_to_user(outp, page_address(schp->pages[k]),
1884 					   num_read_xfer))
1885 				return -EFAULT;
1886 			break;
1887 		} else {
1888 			if (__copy_to_user(outp, page_address(schp->pages[k]),
1889 					   num))
1890 				return -EFAULT;
1891 			num_read_xfer -= num;
1892 			if (num_read_xfer <= 0)
1893 				break;
1894 			outp += num;
1895 		}
1896 	}
1897 
1898 	return 0;
1899 }
1900 
1901 static void
1902 sg_build_reserve(Sg_fd * sfp, int req_size)
1903 {
1904 	Sg_scatter_hold *schp = &sfp->reserve;
1905 
1906 	SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
1907 	do {
1908 		if (req_size < PAGE_SIZE)
1909 			req_size = PAGE_SIZE;
1910 		if (0 == sg_build_indirect(schp, sfp, req_size))
1911 			return;
1912 		else
1913 			sg_remove_scat(schp);
1914 		req_size >>= 1;	/* divide by 2 */
1915 	} while (req_size > (PAGE_SIZE / 2));
1916 }
1917 
1918 static void
1919 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1920 {
1921 	Sg_scatter_hold *req_schp = &srp->data;
1922 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
1923 	int k, num, rem;
1924 
1925 	srp->res_used = 1;
1926 	SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
1927 	rem = size;
1928 
1929 	num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1930 	for (k = 0; k < rsv_schp->k_use_sg; k++) {
1931 		if (rem <= num) {
1932 			req_schp->k_use_sg = k + 1;
1933 			req_schp->sglist_len = rsv_schp->sglist_len;
1934 			req_schp->pages = rsv_schp->pages;
1935 
1936 			req_schp->bufflen = size;
1937 			req_schp->page_order = rsv_schp->page_order;
1938 			break;
1939 		} else
1940 			rem -= num;
1941 	}
1942 
1943 	if (k >= rsv_schp->k_use_sg)
1944 		SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
1945 }
1946 
1947 static void
1948 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
1949 {
1950 	Sg_scatter_hold *req_schp = &srp->data;
1951 
1952 	SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
1953 				   (int) req_schp->k_use_sg));
1954 	req_schp->k_use_sg = 0;
1955 	req_schp->bufflen = 0;
1956 	req_schp->pages = NULL;
1957 	req_schp->page_order = 0;
1958 	req_schp->sglist_len = 0;
1959 	sfp->save_scat_len = 0;
1960 	srp->res_used = 0;
1961 }
1962 
1963 static Sg_request *
1964 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
1965 {
1966 	Sg_request *resp;
1967 	unsigned long iflags;
1968 
1969 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
1970 	for (resp = sfp->headrp; resp; resp = resp->nextrp) {
1971 		/* look for requests that are ready + not SG_IO owned */
1972 		if ((1 == resp->done) && (!resp->sg_io_owned) &&
1973 		    ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
1974 			resp->done = 2;	/* guard against other readers */
1975 			break;
1976 		}
1977 	}
1978 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1979 	return resp;
1980 }
1981 
1982 /* always adds to end of list */
1983 static Sg_request *
1984 sg_add_request(Sg_fd * sfp)
1985 {
1986 	int k;
1987 	unsigned long iflags;
1988 	Sg_request *resp;
1989 	Sg_request *rp = sfp->req_arr;
1990 
1991 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
1992 	resp = sfp->headrp;
1993 	if (!resp) {
1994 		memset(rp, 0, sizeof (Sg_request));
1995 		rp->parentfp = sfp;
1996 		resp = rp;
1997 		sfp->headrp = resp;
1998 	} else {
1999 		if (0 == sfp->cmd_q)
2000 			resp = NULL;	/* command queuing disallowed */
2001 		else {
2002 			for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2003 				if (!rp->parentfp)
2004 					break;
2005 			}
2006 			if (k < SG_MAX_QUEUE) {
2007 				memset(rp, 0, sizeof (Sg_request));
2008 				rp->parentfp = sfp;
2009 				while (resp->nextrp)
2010 					resp = resp->nextrp;
2011 				resp->nextrp = rp;
2012 				resp = rp;
2013 			} else
2014 				resp = NULL;
2015 		}
2016 	}
2017 	if (resp) {
2018 		resp->nextrp = NULL;
2019 		resp->header.duration = jiffies_to_msecs(jiffies);
2020 	}
2021 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2022 	return resp;
2023 }
2024 
2025 /* Return of 1 for found; 0 for not found */
2026 static int
2027 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2028 {
2029 	Sg_request *prev_rp;
2030 	Sg_request *rp;
2031 	unsigned long iflags;
2032 	int res = 0;
2033 
2034 	if ((!sfp) || (!srp) || (!sfp->headrp))
2035 		return res;
2036 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2037 	prev_rp = sfp->headrp;
2038 	if (srp == prev_rp) {
2039 		sfp->headrp = prev_rp->nextrp;
2040 		prev_rp->parentfp = NULL;
2041 		res = 1;
2042 	} else {
2043 		while ((rp = prev_rp->nextrp)) {
2044 			if (srp == rp) {
2045 				prev_rp->nextrp = rp->nextrp;
2046 				rp->parentfp = NULL;
2047 				res = 1;
2048 				break;
2049 			}
2050 			prev_rp = rp;
2051 		}
2052 	}
2053 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2054 	return res;
2055 }
2056 
2057 static Sg_fd *
2058 sg_add_sfp(Sg_device * sdp, int dev)
2059 {
2060 	Sg_fd *sfp;
2061 	unsigned long iflags;
2062 	int bufflen;
2063 
2064 	sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2065 	if (!sfp)
2066 		return NULL;
2067 
2068 	init_waitqueue_head(&sfp->read_wait);
2069 	rwlock_init(&sfp->rq_list_lock);
2070 
2071 	kref_init(&sfp->f_ref);
2072 	sfp->timeout = SG_DEFAULT_TIMEOUT;
2073 	sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2074 	sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2075 	sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2076 	    sdp->device->host->unchecked_isa_dma : 1;
2077 	sfp->cmd_q = SG_DEF_COMMAND_Q;
2078 	sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2079 	sfp->parentdp = sdp;
2080 	write_lock_irqsave(&sg_index_lock, iflags);
2081 	list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2082 	write_unlock_irqrestore(&sg_index_lock, iflags);
2083 	SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2084 	if (unlikely(sg_big_buff != def_reserved_size))
2085 		sg_big_buff = def_reserved_size;
2086 
2087 	bufflen = min_t(int, sg_big_buff,
2088 			queue_max_sectors(sdp->device->request_queue) * 512);
2089 	sg_build_reserve(sfp, bufflen);
2090 	SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2091 			   sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2092 
2093 	kref_get(&sdp->d_ref);
2094 	__module_get(THIS_MODULE);
2095 	return sfp;
2096 }
2097 
2098 static void sg_remove_sfp_usercontext(struct work_struct *work)
2099 {
2100 	struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2101 	struct sg_device *sdp = sfp->parentdp;
2102 
2103 	/* Cleanup any responses which were never read(). */
2104 	while (sfp->headrp)
2105 		sg_finish_rem_req(sfp->headrp);
2106 
2107 	if (sfp->reserve.bufflen > 0) {
2108 		SCSI_LOG_TIMEOUT(6,
2109 			printk("sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2110 				(int) sfp->reserve.bufflen,
2111 				(int) sfp->reserve.k_use_sg));
2112 		sg_remove_scat(&sfp->reserve);
2113 	}
2114 
2115 	SCSI_LOG_TIMEOUT(6,
2116 		printk("sg_remove_sfp: %s, sfp=0x%p\n",
2117 			sdp->disk->disk_name,
2118 			sfp));
2119 	kfree(sfp);
2120 
2121 	scsi_device_put(sdp->device);
2122 	sg_put_dev(sdp);
2123 	module_put(THIS_MODULE);
2124 }
2125 
2126 static void sg_remove_sfp(struct kref *kref)
2127 {
2128 	struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2129 	struct sg_device *sdp = sfp->parentdp;
2130 	unsigned long iflags;
2131 
2132 	write_lock_irqsave(&sg_index_lock, iflags);
2133 	list_del(&sfp->sfd_siblings);
2134 	write_unlock_irqrestore(&sg_index_lock, iflags);
2135 	wake_up_interruptible(&sdp->o_excl_wait);
2136 
2137 	INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2138 	schedule_work(&sfp->ew.work);
2139 }
2140 
2141 static int
2142 sg_res_in_use(Sg_fd * sfp)
2143 {
2144 	const Sg_request *srp;
2145 	unsigned long iflags;
2146 
2147 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
2148 	for (srp = sfp->headrp; srp; srp = srp->nextrp)
2149 		if (srp->res_used)
2150 			break;
2151 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2152 	return srp ? 1 : 0;
2153 }
2154 
2155 #ifdef CONFIG_SCSI_PROC_FS
2156 static int
2157 sg_idr_max_id(int id, void *p, void *data)
2158 {
2159 	int *k = data;
2160 
2161 	if (*k < id)
2162 		*k = id;
2163 
2164 	return 0;
2165 }
2166 
2167 static int
2168 sg_last_dev(void)
2169 {
2170 	int k = -1;
2171 	unsigned long iflags;
2172 
2173 	read_lock_irqsave(&sg_index_lock, iflags);
2174 	idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2175 	read_unlock_irqrestore(&sg_index_lock, iflags);
2176 	return k + 1;		/* origin 1 */
2177 }
2178 #endif
2179 
2180 /* must be called with sg_index_lock held */
2181 static Sg_device *sg_lookup_dev(int dev)
2182 {
2183 	return idr_find(&sg_index_idr, dev);
2184 }
2185 
2186 static Sg_device *sg_get_dev(int dev)
2187 {
2188 	struct sg_device *sdp;
2189 	unsigned long flags;
2190 
2191 	read_lock_irqsave(&sg_index_lock, flags);
2192 	sdp = sg_lookup_dev(dev);
2193 	if (!sdp)
2194 		sdp = ERR_PTR(-ENXIO);
2195 	else if (sdp->detached) {
2196 		/* If sdp->detached, then the refcount may already be 0, in
2197 		 * which case it would be a bug to do kref_get().
2198 		 */
2199 		sdp = ERR_PTR(-ENODEV);
2200 	} else
2201 		kref_get(&sdp->d_ref);
2202 	read_unlock_irqrestore(&sg_index_lock, flags);
2203 
2204 	return sdp;
2205 }
2206 
2207 static void sg_put_dev(struct sg_device *sdp)
2208 {
2209 	kref_put(&sdp->d_ref, sg_device_destroy);
2210 }
2211 
2212 #ifdef CONFIG_SCSI_PROC_FS
2213 
2214 static struct proc_dir_entry *sg_proc_sgp = NULL;
2215 
2216 static char sg_proc_sg_dirname[] = "scsi/sg";
2217 
2218 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2219 
2220 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2221 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2222 			          size_t count, loff_t *off);
2223 static const struct file_operations adio_fops = {
2224 	.owner = THIS_MODULE,
2225 	.open = sg_proc_single_open_adio,
2226 	.read = seq_read,
2227 	.llseek = seq_lseek,
2228 	.write = sg_proc_write_adio,
2229 	.release = single_release,
2230 };
2231 
2232 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2233 static ssize_t sg_proc_write_dressz(struct file *filp,
2234 		const char __user *buffer, size_t count, loff_t *off);
2235 static const struct file_operations dressz_fops = {
2236 	.owner = THIS_MODULE,
2237 	.open = sg_proc_single_open_dressz,
2238 	.read = seq_read,
2239 	.llseek = seq_lseek,
2240 	.write = sg_proc_write_dressz,
2241 	.release = single_release,
2242 };
2243 
2244 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2245 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2246 static const struct file_operations version_fops = {
2247 	.owner = THIS_MODULE,
2248 	.open = sg_proc_single_open_version,
2249 	.read = seq_read,
2250 	.llseek = seq_lseek,
2251 	.release = single_release,
2252 };
2253 
2254 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2255 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2256 static const struct file_operations devhdr_fops = {
2257 	.owner = THIS_MODULE,
2258 	.open = sg_proc_single_open_devhdr,
2259 	.read = seq_read,
2260 	.llseek = seq_lseek,
2261 	.release = single_release,
2262 };
2263 
2264 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2265 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2266 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2267 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2268 static void dev_seq_stop(struct seq_file *s, void *v);
2269 static const struct file_operations dev_fops = {
2270 	.owner = THIS_MODULE,
2271 	.open = sg_proc_open_dev,
2272 	.read = seq_read,
2273 	.llseek = seq_lseek,
2274 	.release = seq_release,
2275 };
2276 static const struct seq_operations dev_seq_ops = {
2277 	.start = dev_seq_start,
2278 	.next  = dev_seq_next,
2279 	.stop  = dev_seq_stop,
2280 	.show  = sg_proc_seq_show_dev,
2281 };
2282 
2283 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2284 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2285 static const struct file_operations devstrs_fops = {
2286 	.owner = THIS_MODULE,
2287 	.open = sg_proc_open_devstrs,
2288 	.read = seq_read,
2289 	.llseek = seq_lseek,
2290 	.release = seq_release,
2291 };
2292 static const struct seq_operations devstrs_seq_ops = {
2293 	.start = dev_seq_start,
2294 	.next  = dev_seq_next,
2295 	.stop  = dev_seq_stop,
2296 	.show  = sg_proc_seq_show_devstrs,
2297 };
2298 
2299 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2300 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2301 static const struct file_operations debug_fops = {
2302 	.owner = THIS_MODULE,
2303 	.open = sg_proc_open_debug,
2304 	.read = seq_read,
2305 	.llseek = seq_lseek,
2306 	.release = seq_release,
2307 };
2308 static const struct seq_operations debug_seq_ops = {
2309 	.start = dev_seq_start,
2310 	.next  = dev_seq_next,
2311 	.stop  = dev_seq_stop,
2312 	.show  = sg_proc_seq_show_debug,
2313 };
2314 
2315 
2316 struct sg_proc_leaf {
2317 	const char * name;
2318 	const struct file_operations * fops;
2319 };
2320 
2321 static const struct sg_proc_leaf sg_proc_leaf_arr[] = {
2322 	{"allow_dio", &adio_fops},
2323 	{"debug", &debug_fops},
2324 	{"def_reserved_size", &dressz_fops},
2325 	{"device_hdr", &devhdr_fops},
2326 	{"devices", &dev_fops},
2327 	{"device_strs", &devstrs_fops},
2328 	{"version", &version_fops}
2329 };
2330 
2331 static int
2332 sg_proc_init(void)
2333 {
2334 	int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2335 	int k;
2336 
2337 	sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2338 	if (!sg_proc_sgp)
2339 		return 1;
2340 	for (k = 0; k < num_leaves; ++k) {
2341 		const struct sg_proc_leaf *leaf = &sg_proc_leaf_arr[k];
2342 		umode_t mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2343 		proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2344 	}
2345 	return 0;
2346 }
2347 
2348 static void
2349 sg_proc_cleanup(void)
2350 {
2351 	int k;
2352 	int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2353 
2354 	if (!sg_proc_sgp)
2355 		return;
2356 	for (k = 0; k < num_leaves; ++k)
2357 		remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2358 	remove_proc_entry(sg_proc_sg_dirname, NULL);
2359 }
2360 
2361 
2362 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2363 {
2364 	seq_printf(s, "%d\n", *((int *)s->private));
2365 	return 0;
2366 }
2367 
2368 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2369 {
2370 	return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2371 }
2372 
2373 static ssize_t
2374 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2375 		   size_t count, loff_t *off)
2376 {
2377 	int err;
2378 	unsigned long num;
2379 
2380 	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2381 		return -EACCES;
2382 	err = kstrtoul_from_user(buffer, count, 0, &num);
2383 	if (err)
2384 		return err;
2385 	sg_allow_dio = num ? 1 : 0;
2386 	return count;
2387 }
2388 
2389 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2390 {
2391 	return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2392 }
2393 
2394 static ssize_t
2395 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2396 		     size_t count, loff_t *off)
2397 {
2398 	int err;
2399 	unsigned long k = ULONG_MAX;
2400 
2401 	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2402 		return -EACCES;
2403 
2404 	err = kstrtoul_from_user(buffer, count, 0, &k);
2405 	if (err)
2406 		return err;
2407 	if (k <= 1048576) {	/* limit "big buff" to 1 MB */
2408 		sg_big_buff = k;
2409 		return count;
2410 	}
2411 	return -ERANGE;
2412 }
2413 
2414 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2415 {
2416 	seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2417 		   sg_version_date);
2418 	return 0;
2419 }
2420 
2421 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2422 {
2423 	return single_open(file, sg_proc_seq_show_version, NULL);
2424 }
2425 
2426 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2427 {
2428 	seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2429 		   "online\n");
2430 	return 0;
2431 }
2432 
2433 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2434 {
2435 	return single_open(file, sg_proc_seq_show_devhdr, NULL);
2436 }
2437 
2438 struct sg_proc_deviter {
2439 	loff_t	index;
2440 	size_t	max;
2441 };
2442 
2443 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2444 {
2445 	struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2446 
2447 	s->private = it;
2448 	if (! it)
2449 		return NULL;
2450 
2451 	it->index = *pos;
2452 	it->max = sg_last_dev();
2453 	if (it->index >= it->max)
2454 		return NULL;
2455 	return it;
2456 }
2457 
2458 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2459 {
2460 	struct sg_proc_deviter * it = s->private;
2461 
2462 	*pos = ++it->index;
2463 	return (it->index < it->max) ? it : NULL;
2464 }
2465 
2466 static void dev_seq_stop(struct seq_file *s, void *v)
2467 {
2468 	kfree(s->private);
2469 }
2470 
2471 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2472 {
2473         return seq_open(file, &dev_seq_ops);
2474 }
2475 
2476 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2477 {
2478 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2479 	Sg_device *sdp;
2480 	struct scsi_device *scsidp;
2481 	unsigned long iflags;
2482 
2483 	read_lock_irqsave(&sg_index_lock, iflags);
2484 	sdp = it ? sg_lookup_dev(it->index) : NULL;
2485 	if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2486 		seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2487 			      scsidp->host->host_no, scsidp->channel,
2488 			      scsidp->id, scsidp->lun, (int) scsidp->type,
2489 			      1,
2490 			      (int) scsidp->queue_depth,
2491 			      (int) scsidp->device_busy,
2492 			      (int) scsi_device_online(scsidp));
2493 	else
2494 		seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2495 	read_unlock_irqrestore(&sg_index_lock, iflags);
2496 	return 0;
2497 }
2498 
2499 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2500 {
2501         return seq_open(file, &devstrs_seq_ops);
2502 }
2503 
2504 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2505 {
2506 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2507 	Sg_device *sdp;
2508 	struct scsi_device *scsidp;
2509 	unsigned long iflags;
2510 
2511 	read_lock_irqsave(&sg_index_lock, iflags);
2512 	sdp = it ? sg_lookup_dev(it->index) : NULL;
2513 	if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2514 		seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2515 			   scsidp->vendor, scsidp->model, scsidp->rev);
2516 	else
2517 		seq_printf(s, "<no active device>\n");
2518 	read_unlock_irqrestore(&sg_index_lock, iflags);
2519 	return 0;
2520 }
2521 
2522 /* must be called while holding sg_index_lock */
2523 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2524 {
2525 	int k, m, new_interface, blen, usg;
2526 	Sg_request *srp;
2527 	Sg_fd *fp;
2528 	const sg_io_hdr_t *hp;
2529 	const char * cp;
2530 	unsigned int ms;
2531 
2532 	k = 0;
2533 	list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2534 		k++;
2535 		read_lock(&fp->rq_list_lock); /* irqs already disabled */
2536 		seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2537 			   "(res)sgat=%d low_dma=%d\n", k,
2538 			   jiffies_to_msecs(fp->timeout),
2539 			   fp->reserve.bufflen,
2540 			   (int) fp->reserve.k_use_sg,
2541 			   (int) fp->low_dma);
2542 		seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2543 			   (int) fp->cmd_q, (int) fp->force_packid,
2544 			   (int) fp->keep_orphan);
2545 		for (m = 0, srp = fp->headrp;
2546 				srp != NULL;
2547 				++m, srp = srp->nextrp) {
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_printf(s, cp);
2563 			blen = srp->data.bufflen;
2564 			usg = srp->data.k_use_sg;
2565 			seq_printf(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 (0 == m)
2583 			seq_printf(s, "     No requests active\n");
2584 		read_unlock(&fp->rq_list_lock);
2585 	}
2586 }
2587 
2588 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2589 {
2590         return seq_open(file, &debug_seq_ops);
2591 }
2592 
2593 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2594 {
2595 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2596 	Sg_device *sdp;
2597 	unsigned long iflags;
2598 
2599 	if (it && (0 == it->index)) {
2600 		seq_printf(s, "max_active_device=%d(origin 1)\n",
2601 			   (int)it->max);
2602 		seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2603 	}
2604 
2605 	read_lock_irqsave(&sg_index_lock, iflags);
2606 	sdp = it ? sg_lookup_dev(it->index) : NULL;
2607 	if (sdp && !list_empty(&sdp->sfds)) {
2608 		struct scsi_device *scsidp = sdp->device;
2609 
2610 		seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2611 		if (sdp->detached)
2612 			seq_printf(s, "detached pending close ");
2613 		else
2614 			seq_printf
2615 			    (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2616 			     scsidp->host->host_no,
2617 			     scsidp->channel, scsidp->id,
2618 			     scsidp->lun,
2619 			     scsidp->host->hostt->emulated);
2620 		seq_printf(s, " sg_tablesize=%d excl=%d\n",
2621 			   sdp->sg_tablesize, get_exclude(sdp));
2622 		sg_proc_debug_helper(s, sdp);
2623 	}
2624 	read_unlock_irqrestore(&sg_index_lock, iflags);
2625 	return 0;
2626 }
2627 
2628 #endif				/* CONFIG_SCSI_PROC_FS */
2629 
2630 module_init(init_sg);
2631 module_exit(exit_sg);
2632