xref: /linux/drivers/scsi/sg.c (revision 8b1935e6a36b0967efc593d67ed3aebbfbc1f5b1)
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/fcntl.h>
42 #include <linux/init.h>
43 #include <linux/poll.h>
44 #include <linux/moduleparam.h>
45 #include <linux/cdev.h>
46 #include <linux/idr.h>
47 #include <linux/seq_file.h>
48 #include <linux/blkdev.h>
49 #include <linux/delay.h>
50 #include <linux/blktrace_api.h>
51 #include <linux/smp_lock.h>
52 
53 #include "scsi.h"
54 #include <scsi/scsi_dbg.h>
55 #include <scsi/scsi_host.h>
56 #include <scsi/scsi_driver.h>
57 #include <scsi/scsi_ioctl.h>
58 #include <scsi/sg.h>
59 
60 #include "scsi_logging.h"
61 
62 #ifdef CONFIG_SCSI_PROC_FS
63 #include <linux/proc_fs.h>
64 static char *sg_version_date = "20061027";
65 
66 static int sg_proc_init(void);
67 static void sg_proc_cleanup(void);
68 #endif
69 
70 #define SG_ALLOW_DIO_DEF 0
71 
72 #define SG_MAX_DEVS 32768
73 
74 /*
75  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
76  * Then when using 32 bit integers x * m may overflow during the calculation.
77  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
78  * calculates the same, but prevents the overflow when both m and d
79  * are "small" numbers (like HZ and USER_HZ).
80  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
81  * in 32 bits.
82  */
83 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
84 
85 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
86 
87 int sg_big_buff = SG_DEF_RESERVED_SIZE;
88 /* N.B. This variable is readable and writeable via
89    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
90    of this size (or less if there is not enough memory) will be reserved
91    for use by this file descriptor. [Deprecated usage: this variable is also
92    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
93    the kernel (i.e. it is not a module).] */
94 static int def_reserved_size = -1;	/* picks up init parameter */
95 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
96 
97 static int scatter_elem_sz = SG_SCATTER_SZ;
98 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
99 
100 #define SG_SECTOR_SZ 512
101 
102 static int sg_add(struct device *, struct class_interface *);
103 static void sg_remove(struct device *, struct class_interface *);
104 
105 static DEFINE_IDR(sg_index_idr);
106 static DEFINE_RWLOCK(sg_index_lock);	/* Also used to lock
107 							   file descriptor list for device */
108 
109 static struct class_interface sg_interface = {
110 	.add_dev	= sg_add,
111 	.remove_dev	= sg_remove,
112 };
113 
114 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
115 	unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
116 	unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
117 	unsigned bufflen;	/* Size of (aggregate) data buffer */
118 	struct page **pages;
119 	int page_order;
120 	char dio_in_use;	/* 0->indirect IO (or mmap), 1->dio */
121 	unsigned char cmd_opcode; /* first byte of command */
122 } Sg_scatter_hold;
123 
124 struct sg_device;		/* forward declarations */
125 struct sg_fd;
126 
127 typedef struct sg_request {	/* SG_MAX_QUEUE requests outstanding per file */
128 	struct sg_request *nextrp;	/* NULL -> tail request (slist) */
129 	struct sg_fd *parentfp;	/* NULL -> not in use */
130 	Sg_scatter_hold data;	/* hold buffer, perhaps scatter list */
131 	sg_io_hdr_t header;	/* scsi command+info, see <scsi/sg.h> */
132 	unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
133 	char res_used;		/* 1 -> using reserve buffer, 0 -> not ... */
134 	char orphan;		/* 1 -> drop on sight, 0 -> normal */
135 	char sg_io_owned;	/* 1 -> packet belongs to SG_IO */
136 	volatile char done;	/* 0->before bh, 1->before read, 2->read */
137 	struct request *rq;
138 	struct bio *bio;
139 	struct execute_work ew;
140 } Sg_request;
141 
142 typedef struct sg_fd {		/* holds the state of a file descriptor */
143 	struct list_head sfd_siblings;
144 	struct sg_device *parentdp;	/* owning device */
145 	wait_queue_head_t read_wait;	/* queue read until command done */
146 	rwlock_t rq_list_lock;	/* protect access to list in req_arr */
147 	int timeout;		/* defaults to SG_DEFAULT_TIMEOUT      */
148 	int timeout_user;	/* defaults to SG_DEFAULT_TIMEOUT_USER */
149 	Sg_scatter_hold reserve;	/* buffer held for this file descriptor */
150 	unsigned save_scat_len;	/* original length of trunc. scat. element */
151 	Sg_request *headrp;	/* head of request slist, NULL->empty */
152 	struct fasync_struct *async_qp;	/* used by asynchronous notification */
153 	Sg_request req_arr[SG_MAX_QUEUE];	/* used as singly-linked list */
154 	char low_dma;		/* as in parent but possibly overridden to 1 */
155 	char force_packid;	/* 1 -> pack_id input to read(), 0 -> ignored */
156 	volatile char closed;	/* 1 -> fd closed but request(s) outstanding */
157 	char cmd_q;		/* 1 -> allow command queuing, 0 -> don't */
158 	char next_cmd_len;	/* 0 -> automatic (def), >0 -> use on next write() */
159 	char keep_orphan;	/* 0 -> drop orphan (def), 1 -> keep for read() */
160 	char mmap_called;	/* 0 -> mmap() never called on this fd */
161 	struct kref f_ref;
162 	struct execute_work ew;
163 } Sg_fd;
164 
165 typedef struct sg_device { /* holds the state of each scsi generic device */
166 	struct scsi_device *device;
167 	wait_queue_head_t o_excl_wait;	/* queue open() when O_EXCL in use */
168 	int sg_tablesize;	/* adapter's max scatter-gather table size */
169 	u32 index;		/* device index number */
170 	struct list_head sfds;
171 	volatile char detached;	/* 0->attached, 1->detached pending removal */
172 	volatile char exclude;	/* opened for exclusive access */
173 	char sgdebug;		/* 0->off, 1->sense, 9->dump dev, 10-> all devs */
174 	struct gendisk *disk;
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 */
180 static void sg_rq_end_io(struct request *rq, int uptodate);
181 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
182 static int sg_finish_rem_req(Sg_request * srp);
183 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
184 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
185 			   Sg_request * srp);
186 static 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);
189 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
190 			   unsigned char *cmnd, int timeout, int blocking);
191 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
192 static void sg_remove_scat(Sg_scatter_hold * schp);
193 static void sg_build_reserve(Sg_fd * sfp, int req_size);
194 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
195 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
196 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
197 static void sg_remove_sfp(struct kref *);
198 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
199 static Sg_request *sg_add_request(Sg_fd * sfp);
200 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
201 static int sg_res_in_use(Sg_fd * sfp);
202 static Sg_device *sg_get_dev(int dev);
203 static void sg_put_dev(Sg_device *sdp);
204 
205 #define SZ_SG_HEADER sizeof(struct sg_header)
206 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
207 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
208 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
209 
210 static int sg_allow_access(struct file *filp, unsigned char *cmd)
211 {
212 	struct sg_fd *sfp = (struct sg_fd *)filp->private_data;
213 
214 	if (sfp->parentdp->device->type == TYPE_SCANNER)
215 		return 0;
216 
217 	return blk_verify_command(cmd, filp->f_mode & FMODE_WRITE);
218 }
219 
220 static int
221 sg_open(struct inode *inode, struct file *filp)
222 {
223 	int dev = iminor(inode);
224 	int flags = filp->f_flags;
225 	struct request_queue *q;
226 	Sg_device *sdp;
227 	Sg_fd *sfp;
228 	int res;
229 	int retval;
230 
231 	lock_kernel();
232 	nonseekable_open(inode, filp);
233 	SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
234 	sdp = sg_get_dev(dev);
235 	if (IS_ERR(sdp)) {
236 		retval = PTR_ERR(sdp);
237 		sdp = NULL;
238 		goto sg_put;
239 	}
240 
241 	/* This driver's module count bumped by fops_get in <linux/fs.h> */
242 	/* Prevent the device driver from vanishing while we sleep */
243 	retval = scsi_device_get(sdp->device);
244 	if (retval)
245 		goto sg_put;
246 
247 	if (!((flags & O_NONBLOCK) ||
248 	      scsi_block_when_processing_errors(sdp->device))) {
249 		retval = -ENXIO;
250 		/* we are in error recovery for this device */
251 		goto error_out;
252 	}
253 
254 	if (flags & O_EXCL) {
255 		if (O_RDONLY == (flags & O_ACCMODE)) {
256 			retval = -EPERM; /* Can't lock it with read only access */
257 			goto error_out;
258 		}
259 		if (!list_empty(&sdp->sfds) && (flags & O_NONBLOCK)) {
260 			retval = -EBUSY;
261 			goto error_out;
262 		}
263 		res = 0;
264 		__wait_event_interruptible(sdp->o_excl_wait,
265 					   ((!list_empty(&sdp->sfds) || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
266 		if (res) {
267 			retval = res;	/* -ERESTARTSYS because signal hit process */
268 			goto error_out;
269 		}
270 	} else if (sdp->exclude) {	/* some other fd has an exclusive lock on dev */
271 		if (flags & O_NONBLOCK) {
272 			retval = -EBUSY;
273 			goto error_out;
274 		}
275 		res = 0;
276 		__wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
277 					   res);
278 		if (res) {
279 			retval = res;	/* -ERESTARTSYS because signal hit process */
280 			goto error_out;
281 		}
282 	}
283 	if (sdp->detached) {
284 		retval = -ENODEV;
285 		goto error_out;
286 	}
287 	if (list_empty(&sdp->sfds)) {	/* no existing opens on this device */
288 		sdp->sgdebug = 0;
289 		q = sdp->device->request_queue;
290 		sdp->sg_tablesize = queue_max_segments(q);
291 	}
292 	if ((sfp = sg_add_sfp(sdp, dev)))
293 		filp->private_data = sfp;
294 	else {
295 		if (flags & O_EXCL) {
296 			sdp->exclude = 0;	/* undo if error */
297 			wake_up_interruptible(&sdp->o_excl_wait);
298 		}
299 		retval = -ENOMEM;
300 		goto error_out;
301 	}
302 	retval = 0;
303 error_out:
304 	if (retval)
305 		scsi_device_put(sdp->device);
306 sg_put:
307 	if (sdp)
308 		sg_put_dev(sdp);
309 	unlock_kernel();
310 	return retval;
311 }
312 
313 /* Following function was formerly called 'sg_close' */
314 static int
315 sg_release(struct inode *inode, struct file *filp)
316 {
317 	Sg_device *sdp;
318 	Sg_fd *sfp;
319 
320 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
321 		return -ENXIO;
322 	SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
323 
324 	sfp->closed = 1;
325 
326 	sdp->exclude = 0;
327 	wake_up_interruptible(&sdp->o_excl_wait);
328 
329 	kref_put(&sfp->f_ref, sg_remove_sfp);
330 	return 0;
331 }
332 
333 static ssize_t
334 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
335 {
336 	Sg_device *sdp;
337 	Sg_fd *sfp;
338 	Sg_request *srp;
339 	int req_pack_id = -1;
340 	sg_io_hdr_t *hp;
341 	struct sg_header *old_hdr = NULL;
342 	int retval = 0;
343 
344 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
345 		return -ENXIO;
346 	SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
347 				   sdp->disk->disk_name, (int) count));
348 
349 	if (!access_ok(VERIFY_WRITE, buf, count))
350 		return -EFAULT;
351 	if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
352 		old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
353 		if (!old_hdr)
354 			return -ENOMEM;
355 		if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
356 			retval = -EFAULT;
357 			goto free_old_hdr;
358 		}
359 		if (old_hdr->reply_len < 0) {
360 			if (count >= SZ_SG_IO_HDR) {
361 				sg_io_hdr_t *new_hdr;
362 				new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
363 				if (!new_hdr) {
364 					retval = -ENOMEM;
365 					goto free_old_hdr;
366 				}
367 				retval =__copy_from_user
368 				    (new_hdr, buf, SZ_SG_IO_HDR);
369 				req_pack_id = new_hdr->pack_id;
370 				kfree(new_hdr);
371 				if (retval) {
372 					retval = -EFAULT;
373 					goto free_old_hdr;
374 				}
375 			}
376 		} else
377 			req_pack_id = old_hdr->pack_id;
378 	}
379 	srp = sg_get_rq_mark(sfp, req_pack_id);
380 	if (!srp) {		/* now wait on packet to arrive */
381 		if (sdp->detached) {
382 			retval = -ENODEV;
383 			goto free_old_hdr;
384 		}
385 		if (filp->f_flags & O_NONBLOCK) {
386 			retval = -EAGAIN;
387 			goto free_old_hdr;
388 		}
389 		while (1) {
390 			retval = 0; /* following macro beats race condition */
391 			__wait_event_interruptible(sfp->read_wait,
392 				(sdp->detached ||
393 				(srp = sg_get_rq_mark(sfp, req_pack_id))),
394 				retval);
395 			if (sdp->detached) {
396 				retval = -ENODEV;
397 				goto free_old_hdr;
398 			}
399 			if (0 == retval)
400 				break;
401 
402 			/* -ERESTARTSYS as signal hit process */
403 			goto free_old_hdr;
404 		}
405 	}
406 	if (srp->header.interface_id != '\0') {
407 		retval = sg_new_read(sfp, buf, count, srp);
408 		goto free_old_hdr;
409 	}
410 
411 	hp = &srp->header;
412 	if (old_hdr == NULL) {
413 		old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
414 		if (! old_hdr) {
415 			retval = -ENOMEM;
416 			goto free_old_hdr;
417 		}
418 	}
419 	memset(old_hdr, 0, SZ_SG_HEADER);
420 	old_hdr->reply_len = (int) hp->timeout;
421 	old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
422 	old_hdr->pack_id = hp->pack_id;
423 	old_hdr->twelve_byte =
424 	    ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
425 	old_hdr->target_status = hp->masked_status;
426 	old_hdr->host_status = hp->host_status;
427 	old_hdr->driver_status = hp->driver_status;
428 	if ((CHECK_CONDITION & hp->masked_status) ||
429 	    (DRIVER_SENSE & hp->driver_status))
430 		memcpy(old_hdr->sense_buffer, srp->sense_b,
431 		       sizeof (old_hdr->sense_buffer));
432 	switch (hp->host_status) {
433 	/* This setup of 'result' is for backward compatibility and is best
434 	   ignored by the user who should use target, host + driver status */
435 	case DID_OK:
436 	case DID_PASSTHROUGH:
437 	case DID_SOFT_ERROR:
438 		old_hdr->result = 0;
439 		break;
440 	case DID_NO_CONNECT:
441 	case DID_BUS_BUSY:
442 	case DID_TIME_OUT:
443 		old_hdr->result = EBUSY;
444 		break;
445 	case DID_BAD_TARGET:
446 	case DID_ABORT:
447 	case DID_PARITY:
448 	case DID_RESET:
449 	case DID_BAD_INTR:
450 		old_hdr->result = EIO;
451 		break;
452 	case DID_ERROR:
453 		old_hdr->result = (srp->sense_b[0] == 0 &&
454 				  hp->masked_status == GOOD) ? 0 : EIO;
455 		break;
456 	default:
457 		old_hdr->result = EIO;
458 		break;
459 	}
460 
461 	/* Now copy the result back to the user buffer.  */
462 	if (count >= SZ_SG_HEADER) {
463 		if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
464 			retval = -EFAULT;
465 			goto free_old_hdr;
466 		}
467 		buf += SZ_SG_HEADER;
468 		if (count > old_hdr->reply_len)
469 			count = old_hdr->reply_len;
470 		if (count > SZ_SG_HEADER) {
471 			if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
472 				retval = -EFAULT;
473 				goto free_old_hdr;
474 			}
475 		}
476 	} else
477 		count = (old_hdr->result == 0) ? 0 : -EIO;
478 	sg_finish_rem_req(srp);
479 	retval = count;
480 free_old_hdr:
481 	kfree(old_hdr);
482 	return retval;
483 }
484 
485 static ssize_t
486 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
487 {
488 	sg_io_hdr_t *hp = &srp->header;
489 	int err = 0;
490 	int len;
491 
492 	if (count < SZ_SG_IO_HDR) {
493 		err = -EINVAL;
494 		goto err_out;
495 	}
496 	hp->sb_len_wr = 0;
497 	if ((hp->mx_sb_len > 0) && hp->sbp) {
498 		if ((CHECK_CONDITION & hp->masked_status) ||
499 		    (DRIVER_SENSE & hp->driver_status)) {
500 			int sb_len = SCSI_SENSE_BUFFERSIZE;
501 			sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
502 			len = 8 + (int) srp->sense_b[7];	/* Additional sense length field */
503 			len = (len > sb_len) ? sb_len : len;
504 			if (copy_to_user(hp->sbp, srp->sense_b, len)) {
505 				err = -EFAULT;
506 				goto err_out;
507 			}
508 			hp->sb_len_wr = len;
509 		}
510 	}
511 	if (hp->masked_status || hp->host_status || hp->driver_status)
512 		hp->info |= SG_INFO_CHECK;
513 	if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
514 		err = -EFAULT;
515 		goto err_out;
516 	}
517 err_out:
518 	err = sg_finish_rem_req(srp);
519 	return (0 == err) ? count : err;
520 }
521 
522 static ssize_t
523 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
524 {
525 	int mxsize, cmd_size, k;
526 	int input_size, blocking;
527 	unsigned char opcode;
528 	Sg_device *sdp;
529 	Sg_fd *sfp;
530 	Sg_request *srp;
531 	struct sg_header old_hdr;
532 	sg_io_hdr_t *hp;
533 	unsigned char cmnd[MAX_COMMAND_SIZE];
534 
535 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
536 		return -ENXIO;
537 	SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
538 				   sdp->disk->disk_name, (int) count));
539 	if (sdp->detached)
540 		return -ENODEV;
541 	if (!((filp->f_flags & O_NONBLOCK) ||
542 	      scsi_block_when_processing_errors(sdp->device)))
543 		return -ENXIO;
544 
545 	if (!access_ok(VERIFY_READ, buf, count))
546 		return -EFAULT;	/* protects following copy_from_user()s + get_user()s */
547 	if (count < SZ_SG_HEADER)
548 		return -EIO;
549 	if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
550 		return -EFAULT;
551 	blocking = !(filp->f_flags & O_NONBLOCK);
552 	if (old_hdr.reply_len < 0)
553 		return sg_new_write(sfp, filp, buf, count,
554 				    blocking, 0, 0, NULL);
555 	if (count < (SZ_SG_HEADER + 6))
556 		return -EIO;	/* The minimum scsi command length is 6 bytes. */
557 
558 	if (!(srp = sg_add_request(sfp))) {
559 		SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
560 		return -EDOM;
561 	}
562 	buf += SZ_SG_HEADER;
563 	__get_user(opcode, buf);
564 	if (sfp->next_cmd_len > 0) {
565 		if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
566 			SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
567 			sfp->next_cmd_len = 0;
568 			sg_remove_request(sfp, srp);
569 			return -EIO;
570 		}
571 		cmd_size = sfp->next_cmd_len;
572 		sfp->next_cmd_len = 0;	/* reset so only this write() effected */
573 	} else {
574 		cmd_size = COMMAND_SIZE(opcode);	/* based on SCSI command group */
575 		if ((opcode >= 0xc0) && old_hdr.twelve_byte)
576 			cmd_size = 12;
577 	}
578 	SCSI_LOG_TIMEOUT(4, printk(
579 		"sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
580 /* Determine buffer size.  */
581 	input_size = count - cmd_size;
582 	mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
583 	mxsize -= SZ_SG_HEADER;
584 	input_size -= SZ_SG_HEADER;
585 	if (input_size < 0) {
586 		sg_remove_request(sfp, srp);
587 		return -EIO;	/* User did not pass enough bytes for this command. */
588 	}
589 	hp = &srp->header;
590 	hp->interface_id = '\0';	/* indicator of old interface tunnelled */
591 	hp->cmd_len = (unsigned char) cmd_size;
592 	hp->iovec_count = 0;
593 	hp->mx_sb_len = 0;
594 	if (input_size > 0)
595 		hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
596 		    SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
597 	else
598 		hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
599 	hp->dxfer_len = mxsize;
600 	if (hp->dxfer_direction == SG_DXFER_TO_DEV)
601 		hp->dxferp = (char __user *)buf + cmd_size;
602 	else
603 		hp->dxferp = NULL;
604 	hp->sbp = NULL;
605 	hp->timeout = old_hdr.reply_len;	/* structure abuse ... */
606 	hp->flags = input_size;	/* structure abuse ... */
607 	hp->pack_id = old_hdr.pack_id;
608 	hp->usr_ptr = NULL;
609 	if (__copy_from_user(cmnd, buf, cmd_size))
610 		return -EFAULT;
611 	/*
612 	 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
613 	 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
614 	 * is a non-zero input_size, so emit a warning.
615 	 */
616 	if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
617 		static char cmd[TASK_COMM_LEN];
618 		if (strcmp(current->comm, cmd) && printk_ratelimit()) {
619 			printk(KERN_WARNING
620 			       "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
621 			       "guessing data in;\n   "
622 			       "program %s not setting count and/or reply_len properly\n",
623 			       old_hdr.reply_len - (int)SZ_SG_HEADER,
624 			       input_size, (unsigned int) cmnd[0],
625 			       current->comm);
626 			strcpy(cmd, current->comm);
627 		}
628 	}
629 	k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
630 	return (k < 0) ? k : count;
631 }
632 
633 static ssize_t
634 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
635 		 size_t count, int blocking, int read_only, int sg_io_owned,
636 		 Sg_request **o_srp)
637 {
638 	int k;
639 	Sg_request *srp;
640 	sg_io_hdr_t *hp;
641 	unsigned char cmnd[MAX_COMMAND_SIZE];
642 	int timeout;
643 	unsigned long ul_timeout;
644 
645 	if (count < SZ_SG_IO_HDR)
646 		return -EINVAL;
647 	if (!access_ok(VERIFY_READ, buf, count))
648 		return -EFAULT; /* protects following copy_from_user()s + get_user()s */
649 
650 	sfp->cmd_q = 1;	/* when sg_io_hdr seen, set command queuing on */
651 	if (!(srp = sg_add_request(sfp))) {
652 		SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
653 		return -EDOM;
654 	}
655 	srp->sg_io_owned = sg_io_owned;
656 	hp = &srp->header;
657 	if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
658 		sg_remove_request(sfp, srp);
659 		return -EFAULT;
660 	}
661 	if (hp->interface_id != 'S') {
662 		sg_remove_request(sfp, srp);
663 		return -ENOSYS;
664 	}
665 	if (hp->flags & SG_FLAG_MMAP_IO) {
666 		if (hp->dxfer_len > sfp->reserve.bufflen) {
667 			sg_remove_request(sfp, srp);
668 			return -ENOMEM;	/* MMAP_IO size must fit in reserve buffer */
669 		}
670 		if (hp->flags & SG_FLAG_DIRECT_IO) {
671 			sg_remove_request(sfp, srp);
672 			return -EINVAL;	/* either MMAP_IO or DIRECT_IO (not both) */
673 		}
674 		if (sg_res_in_use(sfp)) {
675 			sg_remove_request(sfp, srp);
676 			return -EBUSY;	/* reserve buffer already being used */
677 		}
678 	}
679 	ul_timeout = msecs_to_jiffies(srp->header.timeout);
680 	timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
681 	if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
682 		sg_remove_request(sfp, srp);
683 		return -EMSGSIZE;
684 	}
685 	if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
686 		sg_remove_request(sfp, srp);
687 		return -EFAULT;	/* protects following copy_from_user()s + get_user()s */
688 	}
689 	if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
690 		sg_remove_request(sfp, srp);
691 		return -EFAULT;
692 	}
693 	if (read_only && sg_allow_access(file, cmnd)) {
694 		sg_remove_request(sfp, srp);
695 		return -EPERM;
696 	}
697 	k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
698 	if (k < 0)
699 		return k;
700 	if (o_srp)
701 		*o_srp = srp;
702 	return count;
703 }
704 
705 static int
706 sg_common_write(Sg_fd * sfp, Sg_request * srp,
707 		unsigned char *cmnd, int timeout, int blocking)
708 {
709 	int k, data_dir;
710 	Sg_device *sdp = sfp->parentdp;
711 	sg_io_hdr_t *hp = &srp->header;
712 
713 	srp->data.cmd_opcode = cmnd[0];	/* hold opcode of command */
714 	hp->status = 0;
715 	hp->masked_status = 0;
716 	hp->msg_status = 0;
717 	hp->info = 0;
718 	hp->host_status = 0;
719 	hp->driver_status = 0;
720 	hp->resid = 0;
721 	SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
722 			  (int) cmnd[0], (int) hp->cmd_len));
723 
724 	k = sg_start_req(srp, cmnd);
725 	if (k) {
726 		SCSI_LOG_TIMEOUT(1, printk("sg_common_write: start_req err=%d\n", k));
727 		sg_finish_rem_req(srp);
728 		return k;	/* probably out of space --> ENOMEM */
729 	}
730 	if (sdp->detached) {
731 		sg_finish_rem_req(srp);
732 		return -ENODEV;
733 	}
734 
735 	switch (hp->dxfer_direction) {
736 	case SG_DXFER_TO_FROM_DEV:
737 	case SG_DXFER_FROM_DEV:
738 		data_dir = DMA_FROM_DEVICE;
739 		break;
740 	case SG_DXFER_TO_DEV:
741 		data_dir = DMA_TO_DEVICE;
742 		break;
743 	case SG_DXFER_UNKNOWN:
744 		data_dir = DMA_BIDIRECTIONAL;
745 		break;
746 	default:
747 		data_dir = DMA_NONE;
748 		break;
749 	}
750 	hp->duration = jiffies_to_msecs(jiffies);
751 
752 	srp->rq->timeout = timeout;
753 	kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
754 	blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
755 			      srp->rq, 1, sg_rq_end_io);
756 	return 0;
757 }
758 
759 static int
760 sg_ioctl(struct inode *inode, struct file *filp,
761 	 unsigned int cmd_in, unsigned long arg)
762 {
763 	void __user *p = (void __user *)arg;
764 	int __user *ip = p;
765 	int result, val, read_only;
766 	Sg_device *sdp;
767 	Sg_fd *sfp;
768 	Sg_request *srp;
769 	unsigned long iflags;
770 
771 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
772 		return -ENXIO;
773 
774 	SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
775 				   sdp->disk->disk_name, (int) cmd_in));
776 	read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
777 
778 	switch (cmd_in) {
779 	case SG_IO:
780 		{
781 			int blocking = 1;	/* ignore O_NONBLOCK flag */
782 
783 			if (sdp->detached)
784 				return -ENODEV;
785 			if (!scsi_block_when_processing_errors(sdp->device))
786 				return -ENXIO;
787 			if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
788 				return -EFAULT;
789 			result =
790 			    sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
791 					 blocking, read_only, 1, &srp);
792 			if (result < 0)
793 				return result;
794 			while (1) {
795 				result = 0;	/* following macro to beat race condition */
796 				__wait_event_interruptible(sfp->read_wait,
797 					(srp->done || sdp->detached),
798 					result);
799 				if (sdp->detached)
800 					return -ENODEV;
801 				write_lock_irq(&sfp->rq_list_lock);
802 				if (srp->done) {
803 					srp->done = 2;
804 					write_unlock_irq(&sfp->rq_list_lock);
805 					break;
806 				}
807 				srp->orphan = 1;
808 				write_unlock_irq(&sfp->rq_list_lock);
809 				return result;	/* -ERESTARTSYS because signal hit process */
810 			}
811 			result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
812 			return (result < 0) ? result : 0;
813 		}
814 	case SG_SET_TIMEOUT:
815 		result = get_user(val, ip);
816 		if (result)
817 			return result;
818 		if (val < 0)
819 			return -EIO;
820 		if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
821 		    val = MULDIV (INT_MAX, USER_HZ, HZ);
822 		sfp->timeout_user = val;
823 		sfp->timeout = MULDIV (val, HZ, USER_HZ);
824 
825 		return 0;
826 	case SG_GET_TIMEOUT:	/* N.B. User receives timeout as return value */
827 				/* strange ..., for backward compatibility */
828 		return sfp->timeout_user;
829 	case SG_SET_FORCE_LOW_DMA:
830 		result = get_user(val, ip);
831 		if (result)
832 			return result;
833 		if (val) {
834 			sfp->low_dma = 1;
835 			if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
836 				val = (int) sfp->reserve.bufflen;
837 				sg_remove_scat(&sfp->reserve);
838 				sg_build_reserve(sfp, val);
839 			}
840 		} else {
841 			if (sdp->detached)
842 				return -ENODEV;
843 			sfp->low_dma = sdp->device->host->unchecked_isa_dma;
844 		}
845 		return 0;
846 	case SG_GET_LOW_DMA:
847 		return put_user((int) sfp->low_dma, ip);
848 	case SG_GET_SCSI_ID:
849 		if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
850 			return -EFAULT;
851 		else {
852 			sg_scsi_id_t __user *sg_idp = p;
853 
854 			if (sdp->detached)
855 				return -ENODEV;
856 			__put_user((int) sdp->device->host->host_no,
857 				   &sg_idp->host_no);
858 			__put_user((int) sdp->device->channel,
859 				   &sg_idp->channel);
860 			__put_user((int) sdp->device->id, &sg_idp->scsi_id);
861 			__put_user((int) sdp->device->lun, &sg_idp->lun);
862 			__put_user((int) sdp->device->type, &sg_idp->scsi_type);
863 			__put_user((short) sdp->device->host->cmd_per_lun,
864 				   &sg_idp->h_cmd_per_lun);
865 			__put_user((short) sdp->device->queue_depth,
866 				   &sg_idp->d_queue_depth);
867 			__put_user(0, &sg_idp->unused[0]);
868 			__put_user(0, &sg_idp->unused[1]);
869 			return 0;
870 		}
871 	case SG_SET_FORCE_PACK_ID:
872 		result = get_user(val, ip);
873 		if (result)
874 			return result;
875 		sfp->force_packid = val ? 1 : 0;
876 		return 0;
877 	case SG_GET_PACK_ID:
878 		if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
879 			return -EFAULT;
880 		read_lock_irqsave(&sfp->rq_list_lock, iflags);
881 		for (srp = sfp->headrp; srp; srp = srp->nextrp) {
882 			if ((1 == srp->done) && (!srp->sg_io_owned)) {
883 				read_unlock_irqrestore(&sfp->rq_list_lock,
884 						       iflags);
885 				__put_user(srp->header.pack_id, ip);
886 				return 0;
887 			}
888 		}
889 		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
890 		__put_user(-1, ip);
891 		return 0;
892 	case SG_GET_NUM_WAITING:
893 		read_lock_irqsave(&sfp->rq_list_lock, iflags);
894 		for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
895 			if ((1 == srp->done) && (!srp->sg_io_owned))
896 				++val;
897 		}
898 		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
899 		return put_user(val, ip);
900 	case SG_GET_SG_TABLESIZE:
901 		return put_user(sdp->sg_tablesize, ip);
902 	case SG_SET_RESERVED_SIZE:
903 		result = get_user(val, ip);
904 		if (result)
905 			return result;
906                 if (val < 0)
907                         return -EINVAL;
908 		val = min_t(int, val,
909 			    queue_max_sectors(sdp->device->request_queue) * 512);
910 		if (val != sfp->reserve.bufflen) {
911 			if (sg_res_in_use(sfp) || sfp->mmap_called)
912 				return -EBUSY;
913 			sg_remove_scat(&sfp->reserve);
914 			sg_build_reserve(sfp, val);
915 		}
916 		return 0;
917 	case SG_GET_RESERVED_SIZE:
918 		val = min_t(int, sfp->reserve.bufflen,
919 			    queue_max_sectors(sdp->device->request_queue) * 512);
920 		return put_user(val, ip);
921 	case SG_SET_COMMAND_Q:
922 		result = get_user(val, ip);
923 		if (result)
924 			return result;
925 		sfp->cmd_q = val ? 1 : 0;
926 		return 0;
927 	case SG_GET_COMMAND_Q:
928 		return put_user((int) sfp->cmd_q, ip);
929 	case SG_SET_KEEP_ORPHAN:
930 		result = get_user(val, ip);
931 		if (result)
932 			return result;
933 		sfp->keep_orphan = val;
934 		return 0;
935 	case SG_GET_KEEP_ORPHAN:
936 		return put_user((int) sfp->keep_orphan, ip);
937 	case SG_NEXT_CMD_LEN:
938 		result = get_user(val, ip);
939 		if (result)
940 			return result;
941 		sfp->next_cmd_len = (val > 0) ? val : 0;
942 		return 0;
943 	case SG_GET_VERSION_NUM:
944 		return put_user(sg_version_num, ip);
945 	case SG_GET_ACCESS_COUNT:
946 		/* faked - we don't have a real access count anymore */
947 		val = (sdp->device ? 1 : 0);
948 		return put_user(val, ip);
949 	case SG_GET_REQUEST_TABLE:
950 		if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
951 			return -EFAULT;
952 		else {
953 			sg_req_info_t *rinfo;
954 			unsigned int ms;
955 
956 			rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
957 								GFP_KERNEL);
958 			if (!rinfo)
959 				return -ENOMEM;
960 			read_lock_irqsave(&sfp->rq_list_lock, iflags);
961 			for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
962 			     ++val, srp = srp ? srp->nextrp : srp) {
963 				memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
964 				if (srp) {
965 					rinfo[val].req_state = srp->done + 1;
966 					rinfo[val].problem =
967 					    srp->header.masked_status &
968 					    srp->header.host_status &
969 					    srp->header.driver_status;
970 					if (srp->done)
971 						rinfo[val].duration =
972 							srp->header.duration;
973 					else {
974 						ms = jiffies_to_msecs(jiffies);
975 						rinfo[val].duration =
976 						    (ms > srp->header.duration) ?
977 						    (ms - srp->header.duration) : 0;
978 					}
979 					rinfo[val].orphan = srp->orphan;
980 					rinfo[val].sg_io_owned =
981 							srp->sg_io_owned;
982 					rinfo[val].pack_id =
983 							srp->header.pack_id;
984 					rinfo[val].usr_ptr =
985 							srp->header.usr_ptr;
986 				}
987 			}
988 			read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
989 			result = __copy_to_user(p, rinfo,
990 						SZ_SG_REQ_INFO * SG_MAX_QUEUE);
991 			result = result ? -EFAULT : 0;
992 			kfree(rinfo);
993 			return result;
994 		}
995 	case SG_EMULATED_HOST:
996 		if (sdp->detached)
997 			return -ENODEV;
998 		return put_user(sdp->device->host->hostt->emulated, ip);
999 	case SG_SCSI_RESET:
1000 		if (sdp->detached)
1001 			return -ENODEV;
1002 		if (filp->f_flags & O_NONBLOCK) {
1003 			if (scsi_host_in_recovery(sdp->device->host))
1004 				return -EBUSY;
1005 		} else if (!scsi_block_when_processing_errors(sdp->device))
1006 			return -EBUSY;
1007 		result = get_user(val, ip);
1008 		if (result)
1009 			return result;
1010 		if (SG_SCSI_RESET_NOTHING == val)
1011 			return 0;
1012 		switch (val) {
1013 		case SG_SCSI_RESET_DEVICE:
1014 			val = SCSI_TRY_RESET_DEVICE;
1015 			break;
1016 		case SG_SCSI_RESET_TARGET:
1017 			val = SCSI_TRY_RESET_TARGET;
1018 			break;
1019 		case SG_SCSI_RESET_BUS:
1020 			val = SCSI_TRY_RESET_BUS;
1021 			break;
1022 		case SG_SCSI_RESET_HOST:
1023 			val = SCSI_TRY_RESET_HOST;
1024 			break;
1025 		default:
1026 			return -EINVAL;
1027 		}
1028 		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1029 			return -EACCES;
1030 		return (scsi_reset_provider(sdp->device, val) ==
1031 			SUCCESS) ? 0 : -EIO;
1032 	case SCSI_IOCTL_SEND_COMMAND:
1033 		if (sdp->detached)
1034 			return -ENODEV;
1035 		if (read_only) {
1036 			unsigned char opcode = WRITE_6;
1037 			Scsi_Ioctl_Command __user *siocp = p;
1038 
1039 			if (copy_from_user(&opcode, siocp->data, 1))
1040 				return -EFAULT;
1041 			if (sg_allow_access(filp, &opcode))
1042 				return -EPERM;
1043 		}
1044 		return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1045 	case SG_SET_DEBUG:
1046 		result = get_user(val, ip);
1047 		if (result)
1048 			return result;
1049 		sdp->sgdebug = (char) val;
1050 		return 0;
1051 	case SCSI_IOCTL_GET_IDLUN:
1052 	case SCSI_IOCTL_GET_BUS_NUMBER:
1053 	case SCSI_IOCTL_PROBE_HOST:
1054 	case SG_GET_TRANSFORM:
1055 		if (sdp->detached)
1056 			return -ENODEV;
1057 		return scsi_ioctl(sdp->device, cmd_in, p);
1058 	case BLKSECTGET:
1059 		return put_user(queue_max_sectors(sdp->device->request_queue) * 512,
1060 				ip);
1061 	case BLKTRACESETUP:
1062 		return blk_trace_setup(sdp->device->request_queue,
1063 				       sdp->disk->disk_name,
1064 				       MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1065 				       NULL,
1066 				       (char *)arg);
1067 	case BLKTRACESTART:
1068 		return blk_trace_startstop(sdp->device->request_queue, 1);
1069 	case BLKTRACESTOP:
1070 		return blk_trace_startstop(sdp->device->request_queue, 0);
1071 	case BLKTRACETEARDOWN:
1072 		return blk_trace_remove(sdp->device->request_queue);
1073 	default:
1074 		if (read_only)
1075 			return -EPERM;	/* don't know so take safe approach */
1076 		return scsi_ioctl(sdp->device, cmd_in, p);
1077 	}
1078 }
1079 
1080 #ifdef CONFIG_COMPAT
1081 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1082 {
1083 	Sg_device *sdp;
1084 	Sg_fd *sfp;
1085 	struct scsi_device *sdev;
1086 
1087 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1088 		return -ENXIO;
1089 
1090 	sdev = sdp->device;
1091 	if (sdev->host->hostt->compat_ioctl) {
1092 		int ret;
1093 
1094 		ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1095 
1096 		return ret;
1097 	}
1098 
1099 	return -ENOIOCTLCMD;
1100 }
1101 #endif
1102 
1103 static unsigned int
1104 sg_poll(struct file *filp, poll_table * wait)
1105 {
1106 	unsigned int res = 0;
1107 	Sg_device *sdp;
1108 	Sg_fd *sfp;
1109 	Sg_request *srp;
1110 	int count = 0;
1111 	unsigned long iflags;
1112 
1113 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1114 	    || sfp->closed)
1115 		return POLLERR;
1116 	poll_wait(filp, &sfp->read_wait, wait);
1117 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
1118 	for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1119 		/* if any read waiting, flag it */
1120 		if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1121 			res = POLLIN | POLLRDNORM;
1122 		++count;
1123 	}
1124 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1125 
1126 	if (sdp->detached)
1127 		res |= POLLHUP;
1128 	else if (!sfp->cmd_q) {
1129 		if (0 == count)
1130 			res |= POLLOUT | POLLWRNORM;
1131 	} else if (count < SG_MAX_QUEUE)
1132 		res |= POLLOUT | POLLWRNORM;
1133 	SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1134 				   sdp->disk->disk_name, (int) res));
1135 	return res;
1136 }
1137 
1138 static int
1139 sg_fasync(int fd, struct file *filp, int mode)
1140 {
1141 	Sg_device *sdp;
1142 	Sg_fd *sfp;
1143 
1144 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1145 		return -ENXIO;
1146 	SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1147 				   sdp->disk->disk_name, mode));
1148 
1149 	return fasync_helper(fd, filp, mode, &sfp->async_qp);
1150 }
1151 
1152 static int
1153 sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1154 {
1155 	Sg_fd *sfp;
1156 	unsigned long offset, len, sa;
1157 	Sg_scatter_hold *rsv_schp;
1158 	int k, length;
1159 
1160 	if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1161 		return VM_FAULT_SIGBUS;
1162 	rsv_schp = &sfp->reserve;
1163 	offset = vmf->pgoff << PAGE_SHIFT;
1164 	if (offset >= rsv_schp->bufflen)
1165 		return VM_FAULT_SIGBUS;
1166 	SCSI_LOG_TIMEOUT(3, printk("sg_vma_fault: offset=%lu, scatg=%d\n",
1167 				   offset, rsv_schp->k_use_sg));
1168 	sa = vma->vm_start;
1169 	length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1170 	for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1171 		len = vma->vm_end - sa;
1172 		len = (len < length) ? len : length;
1173 		if (offset < len) {
1174 			struct page *page = nth_page(rsv_schp->pages[k],
1175 						     offset >> PAGE_SHIFT);
1176 			get_page(page);	/* increment page count */
1177 			vmf->page = page;
1178 			return 0; /* success */
1179 		}
1180 		sa += len;
1181 		offset -= len;
1182 	}
1183 
1184 	return VM_FAULT_SIGBUS;
1185 }
1186 
1187 static const struct vm_operations_struct sg_mmap_vm_ops = {
1188 	.fault = sg_vma_fault,
1189 };
1190 
1191 static int
1192 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1193 {
1194 	Sg_fd *sfp;
1195 	unsigned long req_sz, len, sa;
1196 	Sg_scatter_hold *rsv_schp;
1197 	int k, length;
1198 
1199 	if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1200 		return -ENXIO;
1201 	req_sz = vma->vm_end - vma->vm_start;
1202 	SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1203 				   (void *) vma->vm_start, (int) req_sz));
1204 	if (vma->vm_pgoff)
1205 		return -EINVAL;	/* want no offset */
1206 	rsv_schp = &sfp->reserve;
1207 	if (req_sz > rsv_schp->bufflen)
1208 		return -ENOMEM;	/* cannot map more than reserved buffer */
1209 
1210 	sa = vma->vm_start;
1211 	length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1212 	for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1213 		len = vma->vm_end - sa;
1214 		len = (len < length) ? len : length;
1215 		sa += len;
1216 	}
1217 
1218 	sfp->mmap_called = 1;
1219 	vma->vm_flags |= VM_RESERVED;
1220 	vma->vm_private_data = sfp;
1221 	vma->vm_ops = &sg_mmap_vm_ops;
1222 	return 0;
1223 }
1224 
1225 static void sg_rq_end_io_usercontext(struct work_struct *work)
1226 {
1227 	struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1228 	struct sg_fd *sfp = srp->parentfp;
1229 
1230 	sg_finish_rem_req(srp);
1231 	kref_put(&sfp->f_ref, sg_remove_sfp);
1232 }
1233 
1234 /*
1235  * This function is a "bottom half" handler that is called by the mid
1236  * level when a command is completed (or has failed).
1237  */
1238 static void sg_rq_end_io(struct request *rq, int uptodate)
1239 {
1240 	struct sg_request *srp = rq->end_io_data;
1241 	Sg_device *sdp;
1242 	Sg_fd *sfp;
1243 	unsigned long iflags;
1244 	unsigned int ms;
1245 	char *sense;
1246 	int result, resid, done = 1;
1247 
1248 	if (WARN_ON(srp->done != 0))
1249 		return;
1250 
1251 	sfp = srp->parentfp;
1252 	if (WARN_ON(sfp == NULL))
1253 		return;
1254 
1255 	sdp = sfp->parentdp;
1256 	if (unlikely(sdp->detached))
1257 		printk(KERN_INFO "sg_rq_end_io: device detached\n");
1258 
1259 	sense = rq->sense;
1260 	result = rq->errors;
1261 	resid = rq->resid_len;
1262 
1263 	SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1264 		sdp->disk->disk_name, srp->header.pack_id, result));
1265 	srp->header.resid = resid;
1266 	ms = jiffies_to_msecs(jiffies);
1267 	srp->header.duration = (ms > srp->header.duration) ?
1268 				(ms - srp->header.duration) : 0;
1269 	if (0 != result) {
1270 		struct scsi_sense_hdr sshdr;
1271 
1272 		srp->header.status = 0xff & result;
1273 		srp->header.masked_status = status_byte(result);
1274 		srp->header.msg_status = msg_byte(result);
1275 		srp->header.host_status = host_byte(result);
1276 		srp->header.driver_status = driver_byte(result);
1277 		if ((sdp->sgdebug > 0) &&
1278 		    ((CHECK_CONDITION == srp->header.masked_status) ||
1279 		     (COMMAND_TERMINATED == srp->header.masked_status)))
1280 			__scsi_print_sense("sg_cmd_done", sense,
1281 					   SCSI_SENSE_BUFFERSIZE);
1282 
1283 		/* Following if statement is a patch supplied by Eric Youngdale */
1284 		if (driver_byte(result) != 0
1285 		    && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1286 		    && !scsi_sense_is_deferred(&sshdr)
1287 		    && sshdr.sense_key == UNIT_ATTENTION
1288 		    && sdp->device->removable) {
1289 			/* Detected possible disc change. Set the bit - this */
1290 			/* may be used if there are filesystems using this device */
1291 			sdp->device->changed = 1;
1292 		}
1293 	}
1294 	/* Rely on write phase to clean out srp status values, so no "else" */
1295 
1296 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
1297 	if (unlikely(srp->orphan)) {
1298 		if (sfp->keep_orphan)
1299 			srp->sg_io_owned = 0;
1300 		else
1301 			done = 0;
1302 	}
1303 	srp->done = done;
1304 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1305 
1306 	if (likely(done)) {
1307 		/* Now wake up any sg_read() that is waiting for this
1308 		 * packet.
1309 		 */
1310 		wake_up_interruptible(&sfp->read_wait);
1311 		kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1312 		kref_put(&sfp->f_ref, sg_remove_sfp);
1313 	} else {
1314 		INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1315 		schedule_work(&srp->ew.work);
1316 	}
1317 }
1318 
1319 static const struct file_operations sg_fops = {
1320 	.owner = THIS_MODULE,
1321 	.read = sg_read,
1322 	.write = sg_write,
1323 	.poll = sg_poll,
1324 	.ioctl = sg_ioctl,
1325 #ifdef CONFIG_COMPAT
1326 	.compat_ioctl = sg_compat_ioctl,
1327 #endif
1328 	.open = sg_open,
1329 	.mmap = sg_mmap,
1330 	.release = sg_release,
1331 	.fasync = sg_fasync,
1332 };
1333 
1334 static struct class *sg_sysfs_class;
1335 
1336 static int sg_sysfs_valid = 0;
1337 
1338 static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1339 {
1340 	struct request_queue *q = scsidp->request_queue;
1341 	Sg_device *sdp;
1342 	unsigned long iflags;
1343 	int error;
1344 	u32 k;
1345 
1346 	sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1347 	if (!sdp) {
1348 		printk(KERN_WARNING "kmalloc Sg_device failure\n");
1349 		return ERR_PTR(-ENOMEM);
1350 	}
1351 
1352 	if (!idr_pre_get(&sg_index_idr, GFP_KERNEL)) {
1353 		printk(KERN_WARNING "idr expansion Sg_device failure\n");
1354 		error = -ENOMEM;
1355 		goto out;
1356 	}
1357 
1358 	write_lock_irqsave(&sg_index_lock, iflags);
1359 
1360 	error = idr_get_new(&sg_index_idr, sdp, &k);
1361 	if (error) {
1362 		write_unlock_irqrestore(&sg_index_lock, iflags);
1363 		printk(KERN_WARNING "idr allocation Sg_device failure: %d\n",
1364 		       error);
1365 		goto out;
1366 	}
1367 
1368 	if (unlikely(k >= SG_MAX_DEVS))
1369 		goto overflow;
1370 
1371 	SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1372 	sprintf(disk->disk_name, "sg%d", k);
1373 	disk->first_minor = k;
1374 	sdp->disk = disk;
1375 	sdp->device = scsidp;
1376 	INIT_LIST_HEAD(&sdp->sfds);
1377 	init_waitqueue_head(&sdp->o_excl_wait);
1378 	sdp->sg_tablesize = queue_max_segments(q);
1379 	sdp->index = k;
1380 	kref_init(&sdp->d_ref);
1381 
1382 	write_unlock_irqrestore(&sg_index_lock, iflags);
1383 
1384 	error = 0;
1385  out:
1386 	if (error) {
1387 		kfree(sdp);
1388 		return ERR_PTR(error);
1389 	}
1390 	return sdp;
1391 
1392  overflow:
1393 	idr_remove(&sg_index_idr, k);
1394 	write_unlock_irqrestore(&sg_index_lock, iflags);
1395 	sdev_printk(KERN_WARNING, scsidp,
1396 		    "Unable to attach sg device type=%d, minor "
1397 		    "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1398 	error = -ENODEV;
1399 	goto out;
1400 }
1401 
1402 static int
1403 sg_add(struct device *cl_dev, struct class_interface *cl_intf)
1404 {
1405 	struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1406 	struct gendisk *disk;
1407 	Sg_device *sdp = NULL;
1408 	struct cdev * cdev = NULL;
1409 	int error;
1410 	unsigned long iflags;
1411 
1412 	disk = alloc_disk(1);
1413 	if (!disk) {
1414 		printk(KERN_WARNING "alloc_disk failed\n");
1415 		return -ENOMEM;
1416 	}
1417 	disk->major = SCSI_GENERIC_MAJOR;
1418 
1419 	error = -ENOMEM;
1420 	cdev = cdev_alloc();
1421 	if (!cdev) {
1422 		printk(KERN_WARNING "cdev_alloc failed\n");
1423 		goto out;
1424 	}
1425 	cdev->owner = THIS_MODULE;
1426 	cdev->ops = &sg_fops;
1427 
1428 	sdp = sg_alloc(disk, scsidp);
1429 	if (IS_ERR(sdp)) {
1430 		printk(KERN_WARNING "sg_alloc failed\n");
1431 		error = PTR_ERR(sdp);
1432 		goto out;
1433 	}
1434 
1435 	error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1436 	if (error)
1437 		goto cdev_add_err;
1438 
1439 	sdp->cdev = cdev;
1440 	if (sg_sysfs_valid) {
1441 		struct device *sg_class_member;
1442 
1443 		sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1444 						MKDEV(SCSI_GENERIC_MAJOR,
1445 						      sdp->index),
1446 						sdp, "%s", disk->disk_name);
1447 		if (IS_ERR(sg_class_member)) {
1448 			printk(KERN_ERR "sg_add: "
1449 			       "device_create failed\n");
1450 			error = PTR_ERR(sg_class_member);
1451 			goto cdev_add_err;
1452 		}
1453 		error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1454 					  &sg_class_member->kobj, "generic");
1455 		if (error)
1456 			printk(KERN_ERR "sg_add: unable to make symlink "
1457 					"'generic' back to sg%d\n", sdp->index);
1458 	} else
1459 		printk(KERN_WARNING "sg_add: sg_sys Invalid\n");
1460 
1461 	sdev_printk(KERN_NOTICE, scsidp,
1462 		    "Attached scsi generic sg%d type %d\n", sdp->index,
1463 		    scsidp->type);
1464 
1465 	dev_set_drvdata(cl_dev, sdp);
1466 
1467 	return 0;
1468 
1469 cdev_add_err:
1470 	write_lock_irqsave(&sg_index_lock, iflags);
1471 	idr_remove(&sg_index_idr, sdp->index);
1472 	write_unlock_irqrestore(&sg_index_lock, iflags);
1473 	kfree(sdp);
1474 
1475 out:
1476 	put_disk(disk);
1477 	if (cdev)
1478 		cdev_del(cdev);
1479 	return error;
1480 }
1481 
1482 static void sg_device_destroy(struct kref *kref)
1483 {
1484 	struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1485 	unsigned long flags;
1486 
1487 	/* CAUTION!  Note that the device can still be found via idr_find()
1488 	 * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1489 	 * any other cleanup.
1490 	 */
1491 
1492 	write_lock_irqsave(&sg_index_lock, flags);
1493 	idr_remove(&sg_index_idr, sdp->index);
1494 	write_unlock_irqrestore(&sg_index_lock, flags);
1495 
1496 	SCSI_LOG_TIMEOUT(3,
1497 		printk("sg_device_destroy: %s\n",
1498 			sdp->disk->disk_name));
1499 
1500 	put_disk(sdp->disk);
1501 	kfree(sdp);
1502 }
1503 
1504 static void sg_remove(struct device *cl_dev, struct class_interface *cl_intf)
1505 {
1506 	struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1507 	Sg_device *sdp = dev_get_drvdata(cl_dev);
1508 	unsigned long iflags;
1509 	Sg_fd *sfp;
1510 
1511 	if (!sdp || sdp->detached)
1512 		return;
1513 
1514 	SCSI_LOG_TIMEOUT(3, printk("sg_remove: %s\n", sdp->disk->disk_name));
1515 
1516 	/* Need a write lock to set sdp->detached. */
1517 	write_lock_irqsave(&sg_index_lock, iflags);
1518 	sdp->detached = 1;
1519 	list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1520 		wake_up_interruptible(&sfp->read_wait);
1521 		kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1522 	}
1523 	write_unlock_irqrestore(&sg_index_lock, iflags);
1524 
1525 	sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1526 	device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1527 	cdev_del(sdp->cdev);
1528 	sdp->cdev = NULL;
1529 
1530 	sg_put_dev(sdp);
1531 }
1532 
1533 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1534 module_param_named(def_reserved_size, def_reserved_size, int,
1535 		   S_IRUGO | S_IWUSR);
1536 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1537 
1538 MODULE_AUTHOR("Douglas Gilbert");
1539 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1540 MODULE_LICENSE("GPL");
1541 MODULE_VERSION(SG_VERSION_STR);
1542 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1543 
1544 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1545                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1546 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1547 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1548 
1549 static int __init
1550 init_sg(void)
1551 {
1552 	int rc;
1553 
1554 	if (scatter_elem_sz < PAGE_SIZE) {
1555 		scatter_elem_sz = PAGE_SIZE;
1556 		scatter_elem_sz_prev = scatter_elem_sz;
1557 	}
1558 	if (def_reserved_size >= 0)
1559 		sg_big_buff = def_reserved_size;
1560 	else
1561 		def_reserved_size = sg_big_buff;
1562 
1563 	rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1564 				    SG_MAX_DEVS, "sg");
1565 	if (rc)
1566 		return rc;
1567         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1568         if ( IS_ERR(sg_sysfs_class) ) {
1569 		rc = PTR_ERR(sg_sysfs_class);
1570 		goto err_out;
1571         }
1572 	sg_sysfs_valid = 1;
1573 	rc = scsi_register_interface(&sg_interface);
1574 	if (0 == rc) {
1575 #ifdef CONFIG_SCSI_PROC_FS
1576 		sg_proc_init();
1577 #endif				/* CONFIG_SCSI_PROC_FS */
1578 		return 0;
1579 	}
1580 	class_destroy(sg_sysfs_class);
1581 err_out:
1582 	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1583 	return rc;
1584 }
1585 
1586 static void __exit
1587 exit_sg(void)
1588 {
1589 #ifdef CONFIG_SCSI_PROC_FS
1590 	sg_proc_cleanup();
1591 #endif				/* CONFIG_SCSI_PROC_FS */
1592 	scsi_unregister_interface(&sg_interface);
1593 	class_destroy(sg_sysfs_class);
1594 	sg_sysfs_valid = 0;
1595 	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1596 				 SG_MAX_DEVS);
1597 	idr_destroy(&sg_index_idr);
1598 }
1599 
1600 static int sg_start_req(Sg_request *srp, unsigned char *cmd)
1601 {
1602 	int res;
1603 	struct request *rq;
1604 	Sg_fd *sfp = srp->parentfp;
1605 	sg_io_hdr_t *hp = &srp->header;
1606 	int dxfer_len = (int) hp->dxfer_len;
1607 	int dxfer_dir = hp->dxfer_direction;
1608 	unsigned int iov_count = hp->iovec_count;
1609 	Sg_scatter_hold *req_schp = &srp->data;
1610 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
1611 	struct request_queue *q = sfp->parentdp->device->request_queue;
1612 	struct rq_map_data *md, map_data;
1613 	int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1614 
1615 	SCSI_LOG_TIMEOUT(4, printk(KERN_INFO "sg_start_req: dxfer_len=%d\n",
1616 				   dxfer_len));
1617 
1618 	rq = blk_get_request(q, rw, GFP_ATOMIC);
1619 	if (!rq)
1620 		return -ENOMEM;
1621 
1622 	memcpy(rq->cmd, cmd, hp->cmd_len);
1623 
1624 	rq->cmd_len = hp->cmd_len;
1625 	rq->cmd_type = REQ_TYPE_BLOCK_PC;
1626 
1627 	srp->rq = rq;
1628 	rq->end_io_data = srp;
1629 	rq->sense = srp->sense_b;
1630 	rq->retries = SG_DEFAULT_RETRIES;
1631 
1632 	if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1633 		return 0;
1634 
1635 	if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1636 	    dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1637 	    !sfp->parentdp->device->host->unchecked_isa_dma &&
1638 	    blk_rq_aligned(q, hp->dxferp, dxfer_len))
1639 		md = NULL;
1640 	else
1641 		md = &map_data;
1642 
1643 	if (md) {
1644 		if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen)
1645 			sg_link_reserve(sfp, srp, dxfer_len);
1646 		else {
1647 			res = sg_build_indirect(req_schp, sfp, dxfer_len);
1648 			if (res)
1649 				return res;
1650 		}
1651 
1652 		md->pages = req_schp->pages;
1653 		md->page_order = req_schp->page_order;
1654 		md->nr_entries = req_schp->k_use_sg;
1655 		md->offset = 0;
1656 		md->null_mapped = hp->dxferp ? 0 : 1;
1657 		if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1658 			md->from_user = 1;
1659 		else
1660 			md->from_user = 0;
1661 	}
1662 
1663 	if (iov_count) {
1664 		int len, size = sizeof(struct sg_iovec) * iov_count;
1665 		struct iovec *iov;
1666 
1667 		iov = kmalloc(size, GFP_ATOMIC);
1668 		if (!iov)
1669 			return -ENOMEM;
1670 
1671 		if (copy_from_user(iov, hp->dxferp, size)) {
1672 			kfree(iov);
1673 			return -EFAULT;
1674 		}
1675 
1676 		len = iov_length(iov, iov_count);
1677 		if (hp->dxfer_len < len) {
1678 			iov_count = iov_shorten(iov, iov_count, hp->dxfer_len);
1679 			len = hp->dxfer_len;
1680 		}
1681 
1682 		res = blk_rq_map_user_iov(q, rq, md, (struct sg_iovec *)iov,
1683 					  iov_count,
1684 					  len, GFP_ATOMIC);
1685 		kfree(iov);
1686 	} else
1687 		res = blk_rq_map_user(q, rq, md, hp->dxferp,
1688 				      hp->dxfer_len, GFP_ATOMIC);
1689 
1690 	if (!res) {
1691 		srp->bio = rq->bio;
1692 
1693 		if (!md) {
1694 			req_schp->dio_in_use = 1;
1695 			hp->info |= SG_INFO_DIRECT_IO;
1696 		}
1697 	}
1698 	return res;
1699 }
1700 
1701 static int sg_finish_rem_req(Sg_request * srp)
1702 {
1703 	int ret = 0;
1704 
1705 	Sg_fd *sfp = srp->parentfp;
1706 	Sg_scatter_hold *req_schp = &srp->data;
1707 
1708 	SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1709 	if (srp->rq) {
1710 		if (srp->bio)
1711 			ret = blk_rq_unmap_user(srp->bio);
1712 
1713 		blk_put_request(srp->rq);
1714 	}
1715 
1716 	if (srp->res_used)
1717 		sg_unlink_reserve(sfp, srp);
1718 	else
1719 		sg_remove_scat(req_schp);
1720 
1721 	sg_remove_request(sfp, srp);
1722 
1723 	return ret;
1724 }
1725 
1726 static int
1727 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1728 {
1729 	int sg_bufflen = tablesize * sizeof(struct page *);
1730 	gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1731 
1732 	schp->pages = kzalloc(sg_bufflen, gfp_flags);
1733 	if (!schp->pages)
1734 		return -ENOMEM;
1735 	schp->sglist_len = sg_bufflen;
1736 	return tablesize;	/* number of scat_gath elements allocated */
1737 }
1738 
1739 static int
1740 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1741 {
1742 	int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1743 	int sg_tablesize = sfp->parentdp->sg_tablesize;
1744 	int blk_size = buff_size, order;
1745 	gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1746 
1747 	if (blk_size < 0)
1748 		return -EFAULT;
1749 	if (0 == blk_size)
1750 		++blk_size;	/* don't know why */
1751 	/* round request up to next highest SG_SECTOR_SZ byte boundary */
1752 	blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1753 	SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1754 				   buff_size, blk_size));
1755 
1756 	/* N.B. ret_sz carried into this block ... */
1757 	mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1758 	if (mx_sc_elems < 0)
1759 		return mx_sc_elems;	/* most likely -ENOMEM */
1760 
1761 	num = scatter_elem_sz;
1762 	if (unlikely(num != scatter_elem_sz_prev)) {
1763 		if (num < PAGE_SIZE) {
1764 			scatter_elem_sz = PAGE_SIZE;
1765 			scatter_elem_sz_prev = PAGE_SIZE;
1766 		} else
1767 			scatter_elem_sz_prev = num;
1768 	}
1769 
1770 	if (sfp->low_dma)
1771 		gfp_mask |= GFP_DMA;
1772 
1773 	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1774 		gfp_mask |= __GFP_ZERO;
1775 
1776 	order = get_order(num);
1777 retry:
1778 	ret_sz = 1 << (PAGE_SHIFT + order);
1779 
1780 	for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1781 	     k++, rem_sz -= ret_sz) {
1782 
1783 		num = (rem_sz > scatter_elem_sz_prev) ?
1784 			scatter_elem_sz_prev : rem_sz;
1785 
1786 		schp->pages[k] = alloc_pages(gfp_mask, order);
1787 		if (!schp->pages[k])
1788 			goto out;
1789 
1790 		if (num == scatter_elem_sz_prev) {
1791 			if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1792 				scatter_elem_sz = ret_sz;
1793 				scatter_elem_sz_prev = ret_sz;
1794 			}
1795 		}
1796 
1797 		SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k=%d, num=%d, "
1798 				 "ret_sz=%d\n", k, num, ret_sz));
1799 	}		/* end of for loop */
1800 
1801 	schp->page_order = order;
1802 	schp->k_use_sg = k;
1803 	SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, "
1804 			 "rem_sz=%d\n", k, rem_sz));
1805 
1806 	schp->bufflen = blk_size;
1807 	if (rem_sz > 0)	/* must have failed */
1808 		return -ENOMEM;
1809 	return 0;
1810 out:
1811 	for (i = 0; i < k; i++)
1812 		__free_pages(schp->pages[i], order);
1813 
1814 	if (--order >= 0)
1815 		goto retry;
1816 
1817 	return -ENOMEM;
1818 }
1819 
1820 static void
1821 sg_remove_scat(Sg_scatter_hold * schp)
1822 {
1823 	SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1824 	if (schp->pages && schp->sglist_len > 0) {
1825 		if (!schp->dio_in_use) {
1826 			int k;
1827 
1828 			for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1829 				SCSI_LOG_TIMEOUT(5, printk(
1830 				    "sg_remove_scat: k=%d, pg=0x%p\n",
1831 				    k, schp->pages[k]));
1832 				__free_pages(schp->pages[k], schp->page_order);
1833 			}
1834 
1835 			kfree(schp->pages);
1836 		}
1837 	}
1838 	memset(schp, 0, sizeof (*schp));
1839 }
1840 
1841 static int
1842 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1843 {
1844 	Sg_scatter_hold *schp = &srp->data;
1845 	int k, num;
1846 
1847 	SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
1848 				   num_read_xfer));
1849 	if ((!outp) || (num_read_xfer <= 0))
1850 		return 0;
1851 
1852 	num = 1 << (PAGE_SHIFT + schp->page_order);
1853 	for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1854 		if (num > num_read_xfer) {
1855 			if (__copy_to_user(outp, page_address(schp->pages[k]),
1856 					   num_read_xfer))
1857 				return -EFAULT;
1858 			break;
1859 		} else {
1860 			if (__copy_to_user(outp, page_address(schp->pages[k]),
1861 					   num))
1862 				return -EFAULT;
1863 			num_read_xfer -= num;
1864 			if (num_read_xfer <= 0)
1865 				break;
1866 			outp += num;
1867 		}
1868 	}
1869 
1870 	return 0;
1871 }
1872 
1873 static void
1874 sg_build_reserve(Sg_fd * sfp, int req_size)
1875 {
1876 	Sg_scatter_hold *schp = &sfp->reserve;
1877 
1878 	SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
1879 	do {
1880 		if (req_size < PAGE_SIZE)
1881 			req_size = PAGE_SIZE;
1882 		if (0 == sg_build_indirect(schp, sfp, req_size))
1883 			return;
1884 		else
1885 			sg_remove_scat(schp);
1886 		req_size >>= 1;	/* divide by 2 */
1887 	} while (req_size > (PAGE_SIZE / 2));
1888 }
1889 
1890 static void
1891 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1892 {
1893 	Sg_scatter_hold *req_schp = &srp->data;
1894 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
1895 	int k, num, rem;
1896 
1897 	srp->res_used = 1;
1898 	SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
1899 	rem = size;
1900 
1901 	num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1902 	for (k = 0; k < rsv_schp->k_use_sg; k++) {
1903 		if (rem <= num) {
1904 			req_schp->k_use_sg = k + 1;
1905 			req_schp->sglist_len = rsv_schp->sglist_len;
1906 			req_schp->pages = rsv_schp->pages;
1907 
1908 			req_schp->bufflen = size;
1909 			req_schp->page_order = rsv_schp->page_order;
1910 			break;
1911 		} else
1912 			rem -= num;
1913 	}
1914 
1915 	if (k >= rsv_schp->k_use_sg)
1916 		SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
1917 }
1918 
1919 static void
1920 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
1921 {
1922 	Sg_scatter_hold *req_schp = &srp->data;
1923 
1924 	SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
1925 				   (int) req_schp->k_use_sg));
1926 	req_schp->k_use_sg = 0;
1927 	req_schp->bufflen = 0;
1928 	req_schp->pages = NULL;
1929 	req_schp->page_order = 0;
1930 	req_schp->sglist_len = 0;
1931 	sfp->save_scat_len = 0;
1932 	srp->res_used = 0;
1933 }
1934 
1935 static Sg_request *
1936 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
1937 {
1938 	Sg_request *resp;
1939 	unsigned long iflags;
1940 
1941 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
1942 	for (resp = sfp->headrp; resp; resp = resp->nextrp) {
1943 		/* look for requests that are ready + not SG_IO owned */
1944 		if ((1 == resp->done) && (!resp->sg_io_owned) &&
1945 		    ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
1946 			resp->done = 2;	/* guard against other readers */
1947 			break;
1948 		}
1949 	}
1950 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1951 	return resp;
1952 }
1953 
1954 /* always adds to end of list */
1955 static Sg_request *
1956 sg_add_request(Sg_fd * sfp)
1957 {
1958 	int k;
1959 	unsigned long iflags;
1960 	Sg_request *resp;
1961 	Sg_request *rp = sfp->req_arr;
1962 
1963 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
1964 	resp = sfp->headrp;
1965 	if (!resp) {
1966 		memset(rp, 0, sizeof (Sg_request));
1967 		rp->parentfp = sfp;
1968 		resp = rp;
1969 		sfp->headrp = resp;
1970 	} else {
1971 		if (0 == sfp->cmd_q)
1972 			resp = NULL;	/* command queuing disallowed */
1973 		else {
1974 			for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
1975 				if (!rp->parentfp)
1976 					break;
1977 			}
1978 			if (k < SG_MAX_QUEUE) {
1979 				memset(rp, 0, sizeof (Sg_request));
1980 				rp->parentfp = sfp;
1981 				while (resp->nextrp)
1982 					resp = resp->nextrp;
1983 				resp->nextrp = rp;
1984 				resp = rp;
1985 			} else
1986 				resp = NULL;
1987 		}
1988 	}
1989 	if (resp) {
1990 		resp->nextrp = NULL;
1991 		resp->header.duration = jiffies_to_msecs(jiffies);
1992 	}
1993 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1994 	return resp;
1995 }
1996 
1997 /* Return of 1 for found; 0 for not found */
1998 static int
1999 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2000 {
2001 	Sg_request *prev_rp;
2002 	Sg_request *rp;
2003 	unsigned long iflags;
2004 	int res = 0;
2005 
2006 	if ((!sfp) || (!srp) || (!sfp->headrp))
2007 		return res;
2008 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2009 	prev_rp = sfp->headrp;
2010 	if (srp == prev_rp) {
2011 		sfp->headrp = prev_rp->nextrp;
2012 		prev_rp->parentfp = NULL;
2013 		res = 1;
2014 	} else {
2015 		while ((rp = prev_rp->nextrp)) {
2016 			if (srp == rp) {
2017 				prev_rp->nextrp = rp->nextrp;
2018 				rp->parentfp = NULL;
2019 				res = 1;
2020 				break;
2021 			}
2022 			prev_rp = rp;
2023 		}
2024 	}
2025 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2026 	return res;
2027 }
2028 
2029 static Sg_fd *
2030 sg_add_sfp(Sg_device * sdp, int dev)
2031 {
2032 	Sg_fd *sfp;
2033 	unsigned long iflags;
2034 	int bufflen;
2035 
2036 	sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2037 	if (!sfp)
2038 		return NULL;
2039 
2040 	init_waitqueue_head(&sfp->read_wait);
2041 	rwlock_init(&sfp->rq_list_lock);
2042 
2043 	kref_init(&sfp->f_ref);
2044 	sfp->timeout = SG_DEFAULT_TIMEOUT;
2045 	sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2046 	sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2047 	sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2048 	    sdp->device->host->unchecked_isa_dma : 1;
2049 	sfp->cmd_q = SG_DEF_COMMAND_Q;
2050 	sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2051 	sfp->parentdp = sdp;
2052 	write_lock_irqsave(&sg_index_lock, iflags);
2053 	list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2054 	write_unlock_irqrestore(&sg_index_lock, iflags);
2055 	SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2056 	if (unlikely(sg_big_buff != def_reserved_size))
2057 		sg_big_buff = def_reserved_size;
2058 
2059 	bufflen = min_t(int, sg_big_buff,
2060 			queue_max_sectors(sdp->device->request_queue) * 512);
2061 	sg_build_reserve(sfp, bufflen);
2062 	SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2063 			   sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2064 
2065 	kref_get(&sdp->d_ref);
2066 	__module_get(THIS_MODULE);
2067 	return sfp;
2068 }
2069 
2070 static void sg_remove_sfp_usercontext(struct work_struct *work)
2071 {
2072 	struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2073 	struct sg_device *sdp = sfp->parentdp;
2074 
2075 	/* Cleanup any responses which were never read(). */
2076 	while (sfp->headrp)
2077 		sg_finish_rem_req(sfp->headrp);
2078 
2079 	if (sfp->reserve.bufflen > 0) {
2080 		SCSI_LOG_TIMEOUT(6,
2081 			printk("sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2082 				(int) sfp->reserve.bufflen,
2083 				(int) sfp->reserve.k_use_sg));
2084 		sg_remove_scat(&sfp->reserve);
2085 	}
2086 
2087 	SCSI_LOG_TIMEOUT(6,
2088 		printk("sg_remove_sfp: %s, sfp=0x%p\n",
2089 			sdp->disk->disk_name,
2090 			sfp));
2091 	kfree(sfp);
2092 
2093 	scsi_device_put(sdp->device);
2094 	sg_put_dev(sdp);
2095 	module_put(THIS_MODULE);
2096 }
2097 
2098 static void sg_remove_sfp(struct kref *kref)
2099 {
2100 	struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2101 	struct sg_device *sdp = sfp->parentdp;
2102 	unsigned long iflags;
2103 
2104 	write_lock_irqsave(&sg_index_lock, iflags);
2105 	list_del(&sfp->sfd_siblings);
2106 	write_unlock_irqrestore(&sg_index_lock, iflags);
2107 	wake_up_interruptible(&sdp->o_excl_wait);
2108 
2109 	INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2110 	schedule_work(&sfp->ew.work);
2111 }
2112 
2113 static int
2114 sg_res_in_use(Sg_fd * sfp)
2115 {
2116 	const Sg_request *srp;
2117 	unsigned long iflags;
2118 
2119 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
2120 	for (srp = sfp->headrp; srp; srp = srp->nextrp)
2121 		if (srp->res_used)
2122 			break;
2123 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2124 	return srp ? 1 : 0;
2125 }
2126 
2127 #ifdef CONFIG_SCSI_PROC_FS
2128 static int
2129 sg_idr_max_id(int id, void *p, void *data)
2130 {
2131 	int *k = data;
2132 
2133 	if (*k < id)
2134 		*k = id;
2135 
2136 	return 0;
2137 }
2138 
2139 static int
2140 sg_last_dev(void)
2141 {
2142 	int k = -1;
2143 	unsigned long iflags;
2144 
2145 	read_lock_irqsave(&sg_index_lock, iflags);
2146 	idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2147 	read_unlock_irqrestore(&sg_index_lock, iflags);
2148 	return k + 1;		/* origin 1 */
2149 }
2150 #endif
2151 
2152 /* must be called with sg_index_lock held */
2153 static Sg_device *sg_lookup_dev(int dev)
2154 {
2155 	return idr_find(&sg_index_idr, dev);
2156 }
2157 
2158 static Sg_device *sg_get_dev(int dev)
2159 {
2160 	struct sg_device *sdp;
2161 	unsigned long flags;
2162 
2163 	read_lock_irqsave(&sg_index_lock, flags);
2164 	sdp = sg_lookup_dev(dev);
2165 	if (!sdp)
2166 		sdp = ERR_PTR(-ENXIO);
2167 	else if (sdp->detached) {
2168 		/* If sdp->detached, then the refcount may already be 0, in
2169 		 * which case it would be a bug to do kref_get().
2170 		 */
2171 		sdp = ERR_PTR(-ENODEV);
2172 	} else
2173 		kref_get(&sdp->d_ref);
2174 	read_unlock_irqrestore(&sg_index_lock, flags);
2175 
2176 	return sdp;
2177 }
2178 
2179 static void sg_put_dev(struct sg_device *sdp)
2180 {
2181 	kref_put(&sdp->d_ref, sg_device_destroy);
2182 }
2183 
2184 #ifdef CONFIG_SCSI_PROC_FS
2185 
2186 static struct proc_dir_entry *sg_proc_sgp = NULL;
2187 
2188 static char sg_proc_sg_dirname[] = "scsi/sg";
2189 
2190 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2191 
2192 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2193 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2194 			          size_t count, loff_t *off);
2195 static const struct file_operations adio_fops = {
2196 	.owner = THIS_MODULE,
2197 	.open = sg_proc_single_open_adio,
2198 	.read = seq_read,
2199 	.llseek = seq_lseek,
2200 	.write = sg_proc_write_adio,
2201 	.release = single_release,
2202 };
2203 
2204 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2205 static ssize_t sg_proc_write_dressz(struct file *filp,
2206 		const char __user *buffer, size_t count, loff_t *off);
2207 static const struct file_operations dressz_fops = {
2208 	.owner = THIS_MODULE,
2209 	.open = sg_proc_single_open_dressz,
2210 	.read = seq_read,
2211 	.llseek = seq_lseek,
2212 	.write = sg_proc_write_dressz,
2213 	.release = single_release,
2214 };
2215 
2216 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2217 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2218 static const struct file_operations version_fops = {
2219 	.owner = THIS_MODULE,
2220 	.open = sg_proc_single_open_version,
2221 	.read = seq_read,
2222 	.llseek = seq_lseek,
2223 	.release = single_release,
2224 };
2225 
2226 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2227 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2228 static const struct file_operations devhdr_fops = {
2229 	.owner = THIS_MODULE,
2230 	.open = sg_proc_single_open_devhdr,
2231 	.read = seq_read,
2232 	.llseek = seq_lseek,
2233 	.release = single_release,
2234 };
2235 
2236 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2237 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2238 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2239 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2240 static void dev_seq_stop(struct seq_file *s, void *v);
2241 static const struct file_operations dev_fops = {
2242 	.owner = THIS_MODULE,
2243 	.open = sg_proc_open_dev,
2244 	.read = seq_read,
2245 	.llseek = seq_lseek,
2246 	.release = seq_release,
2247 };
2248 static const struct seq_operations dev_seq_ops = {
2249 	.start = dev_seq_start,
2250 	.next  = dev_seq_next,
2251 	.stop  = dev_seq_stop,
2252 	.show  = sg_proc_seq_show_dev,
2253 };
2254 
2255 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2256 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2257 static const struct file_operations devstrs_fops = {
2258 	.owner = THIS_MODULE,
2259 	.open = sg_proc_open_devstrs,
2260 	.read = seq_read,
2261 	.llseek = seq_lseek,
2262 	.release = seq_release,
2263 };
2264 static const struct seq_operations devstrs_seq_ops = {
2265 	.start = dev_seq_start,
2266 	.next  = dev_seq_next,
2267 	.stop  = dev_seq_stop,
2268 	.show  = sg_proc_seq_show_devstrs,
2269 };
2270 
2271 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2272 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2273 static const struct file_operations debug_fops = {
2274 	.owner = THIS_MODULE,
2275 	.open = sg_proc_open_debug,
2276 	.read = seq_read,
2277 	.llseek = seq_lseek,
2278 	.release = seq_release,
2279 };
2280 static const struct seq_operations debug_seq_ops = {
2281 	.start = dev_seq_start,
2282 	.next  = dev_seq_next,
2283 	.stop  = dev_seq_stop,
2284 	.show  = sg_proc_seq_show_debug,
2285 };
2286 
2287 
2288 struct sg_proc_leaf {
2289 	const char * name;
2290 	const struct file_operations * fops;
2291 };
2292 
2293 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2294 	{"allow_dio", &adio_fops},
2295 	{"debug", &debug_fops},
2296 	{"def_reserved_size", &dressz_fops},
2297 	{"device_hdr", &devhdr_fops},
2298 	{"devices", &dev_fops},
2299 	{"device_strs", &devstrs_fops},
2300 	{"version", &version_fops}
2301 };
2302 
2303 static int
2304 sg_proc_init(void)
2305 {
2306 	int k, mask;
2307 	int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2308 	struct sg_proc_leaf * leaf;
2309 
2310 	sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2311 	if (!sg_proc_sgp)
2312 		return 1;
2313 	for (k = 0; k < num_leaves; ++k) {
2314 		leaf = &sg_proc_leaf_arr[k];
2315 		mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2316 		proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2317 	}
2318 	return 0;
2319 }
2320 
2321 static void
2322 sg_proc_cleanup(void)
2323 {
2324 	int k;
2325 	int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2326 
2327 	if (!sg_proc_sgp)
2328 		return;
2329 	for (k = 0; k < num_leaves; ++k)
2330 		remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2331 	remove_proc_entry(sg_proc_sg_dirname, NULL);
2332 }
2333 
2334 
2335 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2336 {
2337 	seq_printf(s, "%d\n", *((int *)s->private));
2338 	return 0;
2339 }
2340 
2341 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2342 {
2343 	return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2344 }
2345 
2346 static ssize_t
2347 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2348 		   size_t count, loff_t *off)
2349 {
2350 	int num;
2351 	char buff[11];
2352 
2353 	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2354 		return -EACCES;
2355 	num = (count < 10) ? count : 10;
2356 	if (copy_from_user(buff, buffer, num))
2357 		return -EFAULT;
2358 	buff[num] = '\0';
2359 	sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2360 	return count;
2361 }
2362 
2363 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2364 {
2365 	return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2366 }
2367 
2368 static ssize_t
2369 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2370 		     size_t count, loff_t *off)
2371 {
2372 	int num;
2373 	unsigned long k = ULONG_MAX;
2374 	char buff[11];
2375 
2376 	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2377 		return -EACCES;
2378 	num = (count < 10) ? count : 10;
2379 	if (copy_from_user(buff, buffer, num))
2380 		return -EFAULT;
2381 	buff[num] = '\0';
2382 	k = simple_strtoul(buff, NULL, 10);
2383 	if (k <= 1048576) {	/* limit "big buff" to 1 MB */
2384 		sg_big_buff = k;
2385 		return count;
2386 	}
2387 	return -ERANGE;
2388 }
2389 
2390 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2391 {
2392 	seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2393 		   sg_version_date);
2394 	return 0;
2395 }
2396 
2397 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2398 {
2399 	return single_open(file, sg_proc_seq_show_version, NULL);
2400 }
2401 
2402 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2403 {
2404 	seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2405 		   "online\n");
2406 	return 0;
2407 }
2408 
2409 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2410 {
2411 	return single_open(file, sg_proc_seq_show_devhdr, NULL);
2412 }
2413 
2414 struct sg_proc_deviter {
2415 	loff_t	index;
2416 	size_t	max;
2417 };
2418 
2419 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2420 {
2421 	struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2422 
2423 	s->private = it;
2424 	if (! it)
2425 		return NULL;
2426 
2427 	it->index = *pos;
2428 	it->max = sg_last_dev();
2429 	if (it->index >= it->max)
2430 		return NULL;
2431 	return it;
2432 }
2433 
2434 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2435 {
2436 	struct sg_proc_deviter * it = s->private;
2437 
2438 	*pos = ++it->index;
2439 	return (it->index < it->max) ? it : NULL;
2440 }
2441 
2442 static void dev_seq_stop(struct seq_file *s, void *v)
2443 {
2444 	kfree(s->private);
2445 }
2446 
2447 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2448 {
2449         return seq_open(file, &dev_seq_ops);
2450 }
2451 
2452 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2453 {
2454 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2455 	Sg_device *sdp;
2456 	struct scsi_device *scsidp;
2457 	unsigned long iflags;
2458 
2459 	read_lock_irqsave(&sg_index_lock, iflags);
2460 	sdp = it ? sg_lookup_dev(it->index) : NULL;
2461 	if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2462 		seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2463 			      scsidp->host->host_no, scsidp->channel,
2464 			      scsidp->id, scsidp->lun, (int) scsidp->type,
2465 			      1,
2466 			      (int) scsidp->queue_depth,
2467 			      (int) scsidp->device_busy,
2468 			      (int) scsi_device_online(scsidp));
2469 	else
2470 		seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2471 	read_unlock_irqrestore(&sg_index_lock, iflags);
2472 	return 0;
2473 }
2474 
2475 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2476 {
2477         return seq_open(file, &devstrs_seq_ops);
2478 }
2479 
2480 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2481 {
2482 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2483 	Sg_device *sdp;
2484 	struct scsi_device *scsidp;
2485 	unsigned long iflags;
2486 
2487 	read_lock_irqsave(&sg_index_lock, iflags);
2488 	sdp = it ? sg_lookup_dev(it->index) : NULL;
2489 	if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2490 		seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2491 			   scsidp->vendor, scsidp->model, scsidp->rev);
2492 	else
2493 		seq_printf(s, "<no active device>\n");
2494 	read_unlock_irqrestore(&sg_index_lock, iflags);
2495 	return 0;
2496 }
2497 
2498 /* must be called while holding sg_index_lock */
2499 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2500 {
2501 	int k, m, new_interface, blen, usg;
2502 	Sg_request *srp;
2503 	Sg_fd *fp;
2504 	const sg_io_hdr_t *hp;
2505 	const char * cp;
2506 	unsigned int ms;
2507 
2508 	k = 0;
2509 	list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2510 		k++;
2511 		read_lock(&fp->rq_list_lock); /* irqs already disabled */
2512 		seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2513 			   "(res)sgat=%d low_dma=%d\n", k,
2514 			   jiffies_to_msecs(fp->timeout),
2515 			   fp->reserve.bufflen,
2516 			   (int) fp->reserve.k_use_sg,
2517 			   (int) fp->low_dma);
2518 		seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2519 			   (int) fp->cmd_q, (int) fp->force_packid,
2520 			   (int) fp->keep_orphan, (int) fp->closed);
2521 		for (m = 0, srp = fp->headrp;
2522 				srp != NULL;
2523 				++m, srp = srp->nextrp) {
2524 			hp = &srp->header;
2525 			new_interface = (hp->interface_id == '\0') ? 0 : 1;
2526 			if (srp->res_used) {
2527 				if (new_interface &&
2528 				    (SG_FLAG_MMAP_IO & hp->flags))
2529 					cp = "     mmap>> ";
2530 				else
2531 					cp = "     rb>> ";
2532 			} else {
2533 				if (SG_INFO_DIRECT_IO_MASK & hp->info)
2534 					cp = "     dio>> ";
2535 				else
2536 					cp = "     ";
2537 			}
2538 			seq_printf(s, cp);
2539 			blen = srp->data.bufflen;
2540 			usg = srp->data.k_use_sg;
2541 			seq_printf(s, srp->done ?
2542 				   ((1 == srp->done) ?  "rcv:" : "fin:")
2543 				   : "act:");
2544 			seq_printf(s, " id=%d blen=%d",
2545 				   srp->header.pack_id, blen);
2546 			if (srp->done)
2547 				seq_printf(s, " dur=%d", hp->duration);
2548 			else {
2549 				ms = jiffies_to_msecs(jiffies);
2550 				seq_printf(s, " t_o/elap=%d/%d",
2551 					(new_interface ? hp->timeout :
2552 						  jiffies_to_msecs(fp->timeout)),
2553 					(ms > hp->duration ? ms - hp->duration : 0));
2554 			}
2555 			seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2556 				   (int) srp->data.cmd_opcode);
2557 		}
2558 		if (0 == m)
2559 			seq_printf(s, "     No requests active\n");
2560 		read_unlock(&fp->rq_list_lock);
2561 	}
2562 }
2563 
2564 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2565 {
2566         return seq_open(file, &debug_seq_ops);
2567 }
2568 
2569 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2570 {
2571 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2572 	Sg_device *sdp;
2573 	unsigned long iflags;
2574 
2575 	if (it && (0 == it->index)) {
2576 		seq_printf(s, "max_active_device=%d(origin 1)\n",
2577 			   (int)it->max);
2578 		seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2579 	}
2580 
2581 	read_lock_irqsave(&sg_index_lock, iflags);
2582 	sdp = it ? sg_lookup_dev(it->index) : NULL;
2583 	if (sdp && !list_empty(&sdp->sfds)) {
2584 		struct scsi_device *scsidp = sdp->device;
2585 
2586 		seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2587 		if (sdp->detached)
2588 			seq_printf(s, "detached pending close ");
2589 		else
2590 			seq_printf
2591 			    (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2592 			     scsidp->host->host_no,
2593 			     scsidp->channel, scsidp->id,
2594 			     scsidp->lun,
2595 			     scsidp->host->hostt->emulated);
2596 		seq_printf(s, " sg_tablesize=%d excl=%d\n",
2597 			   sdp->sg_tablesize, sdp->exclude);
2598 		sg_proc_debug_helper(s, sdp);
2599 	}
2600 	read_unlock_irqrestore(&sg_index_lock, iflags);
2601 	return 0;
2602 }
2603 
2604 #endif				/* CONFIG_SCSI_PROC_FS */
2605 
2606 module_init(init_sg);
2607 module_exit(exit_sg);
2608