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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 - 2014 Douglas Gilbert
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2, or (at your option)
15 * any later version.
16 *
17 */
18
19static int sg_version_num = 30536; /* 2 digits for each component */
20#define SG_VERSION_STR "3.5.36"
21
22/*
23 * D. P. Gilbert (dgilbert@interlog.com), notes:
24 * - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
25 * the kernel/module needs to be built with CONFIG_SCSI_LOGGING
26 * (otherwise the macros compile to empty statements).
27 *
28 */
29#include <linux/module.h>
30
31#include <linux/fs.h>
32#include <linux/kernel.h>
33#include <linux/sched.h>
34#include <linux/string.h>
35#include <linux/mm.h>
36#include <linux/errno.h>
37#include <linux/mtio.h>
38#include <linux/ioctl.h>
39#include <linux/slab.h>
40#include <linux/fcntl.h>
41#include <linux/init.h>
42#include <linux/poll.h>
43#include <linux/moduleparam.h>
44#include <linux/cdev.h>
45#include <linux/idr.h>
46#include <linux/seq_file.h>
47#include <linux/blkdev.h>
48#include <linux/delay.h>
49#include <linux/blktrace_api.h>
50#include <linux/mutex.h>
51#include <linux/atomic.h>
52#include <linux/ratelimit.h>
53#include <linux/uio.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>
66static char *sg_version_date = "20140603";
67
68static int sg_proc_init(void);
69static void sg_proc_cleanup(void);
70#endif
71
72#define SG_ALLOW_DIO_DEF 0
73
74#define SG_MAX_DEVS 32768
75
76/* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
77 * of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater
78 * than 16 bytes are "variable length" whose length is a multiple of 4
79 */
80#define SG_MAX_CDB_SIZE 252
81
82#define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
83
84int sg_big_buff = SG_DEF_RESERVED_SIZE;
85/* N.B. This variable is readable and writeable via
86 /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
87 of this size (or less if there is not enough memory) will be reserved
88 for use by this file descriptor. [Deprecated usage: this variable is also
89 readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
90 the kernel (i.e. it is not a module).] */
91static int def_reserved_size = -1; /* picks up init parameter */
92static int sg_allow_dio = SG_ALLOW_DIO_DEF;
93
94static int scatter_elem_sz = SG_SCATTER_SZ;
95static int scatter_elem_sz_prev = SG_SCATTER_SZ;
96
97#define SG_SECTOR_SZ 512
98
99static int sg_add_device(struct device *, struct class_interface *);
100static void sg_remove_device(struct device *, struct class_interface *);
101
102static DEFINE_IDR(sg_index_idr);
103static DEFINE_RWLOCK(sg_index_lock); /* Also used to lock
104 file descriptor list for device */
105
106static struct class_interface sg_interface = {
107 .add_dev = sg_add_device,
108 .remove_dev = sg_remove_device,
109};
110
111typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
112 unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
113 unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
114 unsigned bufflen; /* Size of (aggregate) data buffer */
115 struct page **pages;
116 int page_order;
117 char dio_in_use; /* 0->indirect IO (or mmap), 1->dio */
118 unsigned char cmd_opcode; /* first byte of command */
119} Sg_scatter_hold;
120
121struct sg_device; /* forward declarations */
122struct sg_fd;
123
124typedef struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */
125 struct list_head entry; /* list entry */
126 struct sg_fd *parentfp; /* NULL -> not in use */
127 Sg_scatter_hold data; /* hold buffer, perhaps scatter list */
128 sg_io_hdr_t header; /* scsi command+info, see <scsi/sg.h> */
129 unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
130 char res_used; /* 1 -> using reserve buffer, 0 -> not ... */
131 char orphan; /* 1 -> drop on sight, 0 -> normal */
132 char sg_io_owned; /* 1 -> packet belongs to SG_IO */
133 /* done protected by rq_list_lock */
134 char done; /* 0->before bh, 1->before read, 2->read */
135 struct request *rq;
136 struct bio *bio;
137 struct execute_work ew;
138} Sg_request;
139
140typedef struct sg_fd { /* holds the state of a file descriptor */
141 struct list_head sfd_siblings; /* protected by device's sfd_lock */
142 struct sg_device *parentdp; /* owning device */
143 wait_queue_head_t read_wait; /* queue read until command done */
144 rwlock_t rq_list_lock; /* protect access to list in req_arr */
145 struct mutex f_mutex; /* protect against changes in this fd */
146 int timeout; /* defaults to SG_DEFAULT_TIMEOUT */
147 int timeout_user; /* defaults to SG_DEFAULT_TIMEOUT_USER */
148 Sg_scatter_hold reserve; /* buffer held for this file descriptor */
149 struct list_head rq_list; /* head of request list */
150 struct fasync_struct *async_qp; /* used by asynchronous notification */
151 Sg_request req_arr[SG_MAX_QUEUE]; /* used as singly-linked list */
152 char force_packid; /* 1 -> pack_id input to read(), 0 -> ignored */
153 char cmd_q; /* 1 -> allow command queuing, 0 -> don't */
154 unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */
155 char keep_orphan; /* 0 -> drop orphan (def), 1 -> keep for read() */
156 char mmap_called; /* 0 -> mmap() never called on this fd */
157 char res_in_use; /* 1 -> 'reserve' array in use */
158 struct kref f_ref;
159 struct execute_work ew;
160} Sg_fd;
161
162typedef struct sg_device { /* holds the state of each scsi generic device */
163 struct scsi_device *device;
164 wait_queue_head_t open_wait; /* queue open() when O_EXCL present */
165 struct mutex open_rel_lock; /* held when in open() or release() */
166 int sg_tablesize; /* adapter's max scatter-gather table size */
167 u32 index; /* device index number */
168 struct list_head sfds;
169 rwlock_t sfd_lock; /* protect access to sfd list */
170 atomic_t detaching; /* 0->device usable, 1->device detaching */
171 bool exclude; /* 1->open(O_EXCL) succeeded and is active */
172 int open_cnt; /* count of opens (perhaps < num(sfds) ) */
173 char sgdebug; /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
174 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 */
180static void sg_rq_end_io(struct request *rq, blk_status_t status);
181static int sg_start_req(Sg_request *srp, unsigned char *cmd);
182static int sg_finish_rem_req(Sg_request * srp);
183static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
184static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
185 Sg_request * srp);
186static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
187 const char __user *buf, size_t count, int blocking,
188 int read_only, int sg_io_owned, Sg_request **o_srp);
189static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
190 unsigned char *cmnd, int timeout, int blocking);
191static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
192static void sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp);
193static void sg_build_reserve(Sg_fd * sfp, int req_size);
194static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
195static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
196static Sg_fd *sg_add_sfp(Sg_device * sdp);
197static void sg_remove_sfp(struct kref *);
198static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
199static Sg_request *sg_add_request(Sg_fd * sfp);
200static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
201static Sg_device *sg_get_dev(int dev);
202static void sg_device_destroy(struct kref *kref);
203
204#define SZ_SG_HEADER sizeof(struct sg_header)
205#define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
206#define SZ_SG_IOVEC sizeof(sg_iovec_t)
207#define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
208
209#define sg_printk(prefix, sdp, fmt, a...) \
210 sdev_prefix_printk(prefix, (sdp)->device, \
211 (sdp)->disk->disk_name, fmt, ##a)
212
213static int sg_allow_access(struct file *filp, unsigned char *cmd)
214{
215 struct sg_fd *sfp = filp->private_data;
216
217 if (sfp->parentdp->device->type == TYPE_SCANNER)
218 return 0;
219
220 return blk_verify_command(cmd, filp->f_mode);
221}
222
223static int
224open_wait(Sg_device *sdp, int flags)
225{
226 int retval = 0;
227
228 if (flags & O_EXCL) {
229 while (sdp->open_cnt > 0) {
230 mutex_unlock(&sdp->open_rel_lock);
231 retval = wait_event_interruptible(sdp->open_wait,
232 (atomic_read(&sdp->detaching) ||
233 !sdp->open_cnt));
234 mutex_lock(&sdp->open_rel_lock);
235
236 if (retval) /* -ERESTARTSYS */
237 return retval;
238 if (atomic_read(&sdp->detaching))
239 return -ENODEV;
240 }
241 } else {
242 while (sdp->exclude) {
243 mutex_unlock(&sdp->open_rel_lock);
244 retval = wait_event_interruptible(sdp->open_wait,
245 (atomic_read(&sdp->detaching) ||
246 !sdp->exclude));
247 mutex_lock(&sdp->open_rel_lock);
248
249 if (retval) /* -ERESTARTSYS */
250 return retval;
251 if (atomic_read(&sdp->detaching))
252 return -ENODEV;
253 }
254 }
255
256 return retval;
257}
258
259/* Returns 0 on success, else a negated errno value */
260static int
261sg_open(struct inode *inode, struct file *filp)
262{
263 int dev = iminor(inode);
264 int flags = filp->f_flags;
265 struct request_queue *q;
266 Sg_device *sdp;
267 Sg_fd *sfp;
268 int retval;
269
270 nonseekable_open(inode, filp);
271 if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
272 return -EPERM; /* Can't lock it with read only access */
273 sdp = sg_get_dev(dev);
274 if (IS_ERR(sdp))
275 return PTR_ERR(sdp);
276
277 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
278 "sg_open: flags=0x%x\n", flags));
279
280 /* This driver's module count bumped by fops_get in <linux/fs.h> */
281 /* Prevent the device driver from vanishing while we sleep */
282 retval = scsi_device_get(sdp->device);
283 if (retval)
284 goto sg_put;
285
286 retval = scsi_autopm_get_device(sdp->device);
287 if (retval)
288 goto sdp_put;
289
290 /* scsi_block_when_processing_errors() may block so bypass
291 * check if O_NONBLOCK. Permits SCSI commands to be issued
292 * during error recovery. Tread carefully. */
293 if (!((flags & O_NONBLOCK) ||
294 scsi_block_when_processing_errors(sdp->device))) {
295 retval = -ENXIO;
296 /* we are in error recovery for this device */
297 goto error_out;
298 }
299
300 mutex_lock(&sdp->open_rel_lock);
301 if (flags & O_NONBLOCK) {
302 if (flags & O_EXCL) {
303 if (sdp->open_cnt > 0) {
304 retval = -EBUSY;
305 goto error_mutex_locked;
306 }
307 } else {
308 if (sdp->exclude) {
309 retval = -EBUSY;
310 goto error_mutex_locked;
311 }
312 }
313 } else {
314 retval = open_wait(sdp, flags);
315 if (retval) /* -ERESTARTSYS or -ENODEV */
316 goto error_mutex_locked;
317 }
318
319 /* N.B. at this point we are holding the open_rel_lock */
320 if (flags & O_EXCL)
321 sdp->exclude = true;
322
323 if (sdp->open_cnt < 1) { /* no existing opens */
324 sdp->sgdebug = 0;
325 q = sdp->device->request_queue;
326 sdp->sg_tablesize = queue_max_segments(q);
327 }
328 sfp = sg_add_sfp(sdp);
329 if (IS_ERR(sfp)) {
330 retval = PTR_ERR(sfp);
331 goto out_undo;
332 }
333
334 filp->private_data = sfp;
335 sdp->open_cnt++;
336 mutex_unlock(&sdp->open_rel_lock);
337
338 retval = 0;
339sg_put:
340 kref_put(&sdp->d_ref, sg_device_destroy);
341 return retval;
342
343out_undo:
344 if (flags & O_EXCL) {
345 sdp->exclude = false; /* undo if error */
346 wake_up_interruptible(&sdp->open_wait);
347 }
348error_mutex_locked:
349 mutex_unlock(&sdp->open_rel_lock);
350error_out:
351 scsi_autopm_put_device(sdp->device);
352sdp_put:
353 scsi_device_put(sdp->device);
354 goto sg_put;
355}
356
357/* Release resources associated with a successful sg_open()
358 * Returns 0 on success, else a negated errno value */
359static int
360sg_release(struct inode *inode, struct file *filp)
361{
362 Sg_device *sdp;
363 Sg_fd *sfp;
364
365 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
366 return -ENXIO;
367 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
368
369 mutex_lock(&sdp->open_rel_lock);
370 scsi_autopm_put_device(sdp->device);
371 kref_put(&sfp->f_ref, sg_remove_sfp);
372 sdp->open_cnt--;
373
374 /* possibly many open()s waiting on exlude clearing, start many;
375 * only open(O_EXCL)s wait on 0==open_cnt so only start one */
376 if (sdp->exclude) {
377 sdp->exclude = false;
378 wake_up_interruptible_all(&sdp->open_wait);
379 } else if (0 == sdp->open_cnt) {
380 wake_up_interruptible(&sdp->open_wait);
381 }
382 mutex_unlock(&sdp->open_rel_lock);
383 return 0;
384}
385
386static ssize_t
387sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
388{
389 Sg_device *sdp;
390 Sg_fd *sfp;
391 Sg_request *srp;
392 int req_pack_id = -1;
393 sg_io_hdr_t *hp;
394 struct sg_header *old_hdr = NULL;
395 int retval = 0;
396
397 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
398 return -ENXIO;
399 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
400 "sg_read: count=%d\n", (int) count));
401
402 if (!access_ok(VERIFY_WRITE, buf, count))
403 return -EFAULT;
404 if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
405 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
406 if (!old_hdr)
407 return -ENOMEM;
408 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
409 retval = -EFAULT;
410 goto free_old_hdr;
411 }
412 if (old_hdr->reply_len < 0) {
413 if (count >= SZ_SG_IO_HDR) {
414 sg_io_hdr_t *new_hdr;
415 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
416 if (!new_hdr) {
417 retval = -ENOMEM;
418 goto free_old_hdr;
419 }
420 retval =__copy_from_user
421 (new_hdr, buf, SZ_SG_IO_HDR);
422 req_pack_id = new_hdr->pack_id;
423 kfree(new_hdr);
424 if (retval) {
425 retval = -EFAULT;
426 goto free_old_hdr;
427 }
428 }
429 } else
430 req_pack_id = old_hdr->pack_id;
431 }
432 srp = sg_get_rq_mark(sfp, req_pack_id);
433 if (!srp) { /* now wait on packet to arrive */
434 if (atomic_read(&sdp->detaching)) {
435 retval = -ENODEV;
436 goto free_old_hdr;
437 }
438 if (filp->f_flags & O_NONBLOCK) {
439 retval = -EAGAIN;
440 goto free_old_hdr;
441 }
442 retval = wait_event_interruptible(sfp->read_wait,
443 (atomic_read(&sdp->detaching) ||
444 (srp = sg_get_rq_mark(sfp, req_pack_id))));
445 if (atomic_read(&sdp->detaching)) {
446 retval = -ENODEV;
447 goto free_old_hdr;
448 }
449 if (retval) {
450 /* -ERESTARTSYS as signal hit process */
451 goto free_old_hdr;
452 }
453 }
454 if (srp->header.interface_id != '\0') {
455 retval = sg_new_read(sfp, buf, count, srp);
456 goto free_old_hdr;
457 }
458
459 hp = &srp->header;
460 if (old_hdr == NULL) {
461 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
462 if (! old_hdr) {
463 retval = -ENOMEM;
464 goto free_old_hdr;
465 }
466 }
467 memset(old_hdr, 0, SZ_SG_HEADER);
468 old_hdr->reply_len = (int) hp->timeout;
469 old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
470 old_hdr->pack_id = hp->pack_id;
471 old_hdr->twelve_byte =
472 ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
473 old_hdr->target_status = hp->masked_status;
474 old_hdr->host_status = hp->host_status;
475 old_hdr->driver_status = hp->driver_status;
476 if ((CHECK_CONDITION & hp->masked_status) ||
477 (DRIVER_SENSE & hp->driver_status))
478 memcpy(old_hdr->sense_buffer, srp->sense_b,
479 sizeof (old_hdr->sense_buffer));
480 switch (hp->host_status) {
481 /* This setup of 'result' is for backward compatibility and is best
482 ignored by the user who should use target, host + driver status */
483 case DID_OK:
484 case DID_PASSTHROUGH:
485 case DID_SOFT_ERROR:
486 old_hdr->result = 0;
487 break;
488 case DID_NO_CONNECT:
489 case DID_BUS_BUSY:
490 case DID_TIME_OUT:
491 old_hdr->result = EBUSY;
492 break;
493 case DID_BAD_TARGET:
494 case DID_ABORT:
495 case DID_PARITY:
496 case DID_RESET:
497 case DID_BAD_INTR:
498 old_hdr->result = EIO;
499 break;
500 case DID_ERROR:
501 old_hdr->result = (srp->sense_b[0] == 0 &&
502 hp->masked_status == GOOD) ? 0 : EIO;
503 break;
504 default:
505 old_hdr->result = EIO;
506 break;
507 }
508
509 /* Now copy the result back to the user buffer. */
510 if (count >= SZ_SG_HEADER) {
511 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
512 retval = -EFAULT;
513 goto free_old_hdr;
514 }
515 buf += SZ_SG_HEADER;
516 if (count > old_hdr->reply_len)
517 count = old_hdr->reply_len;
518 if (count > SZ_SG_HEADER) {
519 if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
520 retval = -EFAULT;
521 goto free_old_hdr;
522 }
523 }
524 } else
525 count = (old_hdr->result == 0) ? 0 : -EIO;
526 sg_finish_rem_req(srp);
527 sg_remove_request(sfp, srp);
528 retval = count;
529free_old_hdr:
530 kfree(old_hdr);
531 return retval;
532}
533
534static ssize_t
535sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
536{
537 sg_io_hdr_t *hp = &srp->header;
538 int err = 0, err2;
539 int len;
540
541 if (count < SZ_SG_IO_HDR) {
542 err = -EINVAL;
543 goto err_out;
544 }
545 hp->sb_len_wr = 0;
546 if ((hp->mx_sb_len > 0) && hp->sbp) {
547 if ((CHECK_CONDITION & hp->masked_status) ||
548 (DRIVER_SENSE & hp->driver_status)) {
549 int sb_len = SCSI_SENSE_BUFFERSIZE;
550 sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
551 len = 8 + (int) srp->sense_b[7]; /* Additional sense length field */
552 len = (len > sb_len) ? sb_len : len;
553 if (copy_to_user(hp->sbp, srp->sense_b, len)) {
554 err = -EFAULT;
555 goto err_out;
556 }
557 hp->sb_len_wr = len;
558 }
559 }
560 if (hp->masked_status || hp->host_status || hp->driver_status)
561 hp->info |= SG_INFO_CHECK;
562 if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
563 err = -EFAULT;
564 goto err_out;
565 }
566err_out:
567 err2 = sg_finish_rem_req(srp);
568 sg_remove_request(sfp, srp);
569 return err ? : err2 ? : count;
570}
571
572static ssize_t
573sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
574{
575 int mxsize, cmd_size, k;
576 int input_size, blocking;
577 unsigned char opcode;
578 Sg_device *sdp;
579 Sg_fd *sfp;
580 Sg_request *srp;
581 struct sg_header old_hdr;
582 sg_io_hdr_t *hp;
583 unsigned char cmnd[SG_MAX_CDB_SIZE];
584
585 if (unlikely(uaccess_kernel()))
586 return -EINVAL;
587
588 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
589 return -ENXIO;
590 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
591 "sg_write: count=%d\n", (int) count));
592 if (atomic_read(&sdp->detaching))
593 return -ENODEV;
594 if (!((filp->f_flags & O_NONBLOCK) ||
595 scsi_block_when_processing_errors(sdp->device)))
596 return -ENXIO;
597
598 if (!access_ok(VERIFY_READ, buf, count))
599 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
600 if (count < SZ_SG_HEADER)
601 return -EIO;
602 if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
603 return -EFAULT;
604 blocking = !(filp->f_flags & O_NONBLOCK);
605 if (old_hdr.reply_len < 0)
606 return sg_new_write(sfp, filp, buf, count,
607 blocking, 0, 0, NULL);
608 if (count < (SZ_SG_HEADER + 6))
609 return -EIO; /* The minimum scsi command length is 6 bytes. */
610
611 if (!(srp = sg_add_request(sfp))) {
612 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
613 "sg_write: queue full\n"));
614 return -EDOM;
615 }
616 buf += SZ_SG_HEADER;
617 __get_user(opcode, buf);
618 mutex_lock(&sfp->f_mutex);
619 if (sfp->next_cmd_len > 0) {
620 cmd_size = sfp->next_cmd_len;
621 sfp->next_cmd_len = 0; /* reset so only this write() effected */
622 } else {
623 cmd_size = COMMAND_SIZE(opcode); /* based on SCSI command group */
624 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
625 cmd_size = 12;
626 }
627 mutex_unlock(&sfp->f_mutex);
628 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
629 "sg_write: scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
630/* Determine buffer size. */
631 input_size = count - cmd_size;
632 mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
633 mxsize -= SZ_SG_HEADER;
634 input_size -= SZ_SG_HEADER;
635 if (input_size < 0) {
636 sg_remove_request(sfp, srp);
637 return -EIO; /* User did not pass enough bytes for this command. */
638 }
639 hp = &srp->header;
640 hp->interface_id = '\0'; /* indicator of old interface tunnelled */
641 hp->cmd_len = (unsigned char) cmd_size;
642 hp->iovec_count = 0;
643 hp->mx_sb_len = 0;
644 if (input_size > 0)
645 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
646 SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
647 else
648 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
649 hp->dxfer_len = mxsize;
650 if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
651 (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
652 hp->dxferp = (char __user *)buf + cmd_size;
653 else
654 hp->dxferp = NULL;
655 hp->sbp = NULL;
656 hp->timeout = old_hdr.reply_len; /* structure abuse ... */
657 hp->flags = input_size; /* structure abuse ... */
658 hp->pack_id = old_hdr.pack_id;
659 hp->usr_ptr = NULL;
660 if (__copy_from_user(cmnd, buf, cmd_size))
661 return -EFAULT;
662 /*
663 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
664 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
665 * is a non-zero input_size, so emit a warning.
666 */
667 if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
668 printk_ratelimited(KERN_WARNING
669 "sg_write: data in/out %d/%d bytes "
670 "for SCSI command 0x%x-- guessing "
671 "data in;\n program %s not setting "
672 "count and/or reply_len properly\n",
673 old_hdr.reply_len - (int)SZ_SG_HEADER,
674 input_size, (unsigned int) cmnd[0],
675 current->comm);
676 }
677 k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
678 return (k < 0) ? k : count;
679}
680
681static ssize_t
682sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
683 size_t count, int blocking, int read_only, int sg_io_owned,
684 Sg_request **o_srp)
685{
686 int k;
687 Sg_request *srp;
688 sg_io_hdr_t *hp;
689 unsigned char cmnd[SG_MAX_CDB_SIZE];
690 int timeout;
691 unsigned long ul_timeout;
692
693 if (count < SZ_SG_IO_HDR)
694 return -EINVAL;
695 if (!access_ok(VERIFY_READ, buf, count))
696 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
697
698 sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
699 if (!(srp = sg_add_request(sfp))) {
700 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
701 "sg_new_write: queue full\n"));
702 return -EDOM;
703 }
704 srp->sg_io_owned = sg_io_owned;
705 hp = &srp->header;
706 if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
707 sg_remove_request(sfp, srp);
708 return -EFAULT;
709 }
710 if (hp->interface_id != 'S') {
711 sg_remove_request(sfp, srp);
712 return -ENOSYS;
713 }
714 if (hp->flags & SG_FLAG_MMAP_IO) {
715 if (hp->dxfer_len > sfp->reserve.bufflen) {
716 sg_remove_request(sfp, srp);
717 return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
718 }
719 if (hp->flags & SG_FLAG_DIRECT_IO) {
720 sg_remove_request(sfp, srp);
721 return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
722 }
723 if (sfp->res_in_use) {
724 sg_remove_request(sfp, srp);
725 return -EBUSY; /* reserve buffer already being used */
726 }
727 }
728 ul_timeout = msecs_to_jiffies(srp->header.timeout);
729 timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
730 if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
731 sg_remove_request(sfp, srp);
732 return -EMSGSIZE;
733 }
734 if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
735 sg_remove_request(sfp, srp);
736 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
737 }
738 if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
739 sg_remove_request(sfp, srp);
740 return -EFAULT;
741 }
742 if (read_only && sg_allow_access(file, cmnd)) {
743 sg_remove_request(sfp, srp);
744 return -EPERM;
745 }
746 k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
747 if (k < 0)
748 return k;
749 if (o_srp)
750 *o_srp = srp;
751 return count;
752}
753
754static int
755sg_common_write(Sg_fd * sfp, Sg_request * srp,
756 unsigned char *cmnd, int timeout, int blocking)
757{
758 int k, at_head;
759 Sg_device *sdp = sfp->parentdp;
760 sg_io_hdr_t *hp = &srp->header;
761
762 srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
763 hp->status = 0;
764 hp->masked_status = 0;
765 hp->msg_status = 0;
766 hp->info = 0;
767 hp->host_status = 0;
768 hp->driver_status = 0;
769 hp->resid = 0;
770 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
771 "sg_common_write: scsi opcode=0x%02x, cmd_size=%d\n",
772 (int) cmnd[0], (int) hp->cmd_len));
773
774 if (hp->dxfer_len >= SZ_256M)
775 return -EINVAL;
776
777 k = sg_start_req(srp, cmnd);
778 if (k) {
779 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
780 "sg_common_write: start_req err=%d\n", k));
781 sg_finish_rem_req(srp);
782 sg_remove_request(sfp, srp);
783 return k; /* probably out of space --> ENOMEM */
784 }
785 if (atomic_read(&sdp->detaching)) {
786 if (srp->bio) {
787 scsi_req_free_cmd(scsi_req(srp->rq));
788 blk_end_request_all(srp->rq, BLK_STS_IOERR);
789 srp->rq = NULL;
790 }
791
792 sg_finish_rem_req(srp);
793 sg_remove_request(sfp, srp);
794 return -ENODEV;
795 }
796
797 hp->duration = jiffies_to_msecs(jiffies);
798 if (hp->interface_id != '\0' && /* v3 (or later) interface */
799 (SG_FLAG_Q_AT_TAIL & hp->flags))
800 at_head = 0;
801 else
802 at_head = 1;
803
804 srp->rq->timeout = timeout;
805 kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
806 blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
807 srp->rq, at_head, sg_rq_end_io);
808 return 0;
809}
810
811static int srp_done(Sg_fd *sfp, Sg_request *srp)
812{
813 unsigned long flags;
814 int ret;
815
816 read_lock_irqsave(&sfp->rq_list_lock, flags);
817 ret = srp->done;
818 read_unlock_irqrestore(&sfp->rq_list_lock, flags);
819 return ret;
820}
821
822static int max_sectors_bytes(struct request_queue *q)
823{
824 unsigned int max_sectors = queue_max_sectors(q);
825
826 max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
827
828 return max_sectors << 9;
829}
830
831static void
832sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
833{
834 Sg_request *srp;
835 int val;
836 unsigned int ms;
837
838 val = 0;
839 list_for_each_entry(srp, &sfp->rq_list, entry) {
840 if (val >= SG_MAX_QUEUE)
841 break;
842 rinfo[val].req_state = srp->done + 1;
843 rinfo[val].problem =
844 srp->header.masked_status &
845 srp->header.host_status &
846 srp->header.driver_status;
847 if (srp->done)
848 rinfo[val].duration =
849 srp->header.duration;
850 else {
851 ms = jiffies_to_msecs(jiffies);
852 rinfo[val].duration =
853 (ms > srp->header.duration) ?
854 (ms - srp->header.duration) : 0;
855 }
856 rinfo[val].orphan = srp->orphan;
857 rinfo[val].sg_io_owned = srp->sg_io_owned;
858 rinfo[val].pack_id = srp->header.pack_id;
859 rinfo[val].usr_ptr = srp->header.usr_ptr;
860 val++;
861 }
862}
863
864static long
865sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
866{
867 void __user *p = (void __user *)arg;
868 int __user *ip = p;
869 int result, val, read_only;
870 Sg_device *sdp;
871 Sg_fd *sfp;
872 Sg_request *srp;
873 unsigned long iflags;
874
875 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
876 return -ENXIO;
877
878 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
879 "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
880 read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
881
882 switch (cmd_in) {
883 case SG_IO:
884 if (atomic_read(&sdp->detaching))
885 return -ENODEV;
886 if (!scsi_block_when_processing_errors(sdp->device))
887 return -ENXIO;
888 if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
889 return -EFAULT;
890 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
891 1, read_only, 1, &srp);
892 if (result < 0)
893 return result;
894 result = wait_event_interruptible(sfp->read_wait,
895 (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
896 if (atomic_read(&sdp->detaching))
897 return -ENODEV;
898 write_lock_irq(&sfp->rq_list_lock);
899 if (srp->done) {
900 srp->done = 2;
901 write_unlock_irq(&sfp->rq_list_lock);
902 result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
903 return (result < 0) ? result : 0;
904 }
905 srp->orphan = 1;
906 write_unlock_irq(&sfp->rq_list_lock);
907 return result; /* -ERESTARTSYS because signal hit process */
908 case SG_SET_TIMEOUT:
909 result = get_user(val, ip);
910 if (result)
911 return result;
912 if (val < 0)
913 return -EIO;
914 if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
915 val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
916 INT_MAX);
917 sfp->timeout_user = val;
918 sfp->timeout = mult_frac(val, HZ, USER_HZ);
919
920 return 0;
921 case SG_GET_TIMEOUT: /* N.B. User receives timeout as return value */
922 /* strange ..., for backward compatibility */
923 return sfp->timeout_user;
924 case SG_SET_FORCE_LOW_DMA:
925 /*
926 * N.B. This ioctl never worked properly, but failed to
927 * return an error value. So returning '0' to keep compability
928 * with legacy applications.
929 */
930 return 0;
931 case SG_GET_LOW_DMA:
932 return put_user((int) sdp->device->host->unchecked_isa_dma, ip);
933 case SG_GET_SCSI_ID:
934 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
935 return -EFAULT;
936 else {
937 sg_scsi_id_t __user *sg_idp = p;
938
939 if (atomic_read(&sdp->detaching))
940 return -ENODEV;
941 __put_user((int) sdp->device->host->host_no,
942 &sg_idp->host_no);
943 __put_user((int) sdp->device->channel,
944 &sg_idp->channel);
945 __put_user((int) sdp->device->id, &sg_idp->scsi_id);
946 __put_user((int) sdp->device->lun, &sg_idp->lun);
947 __put_user((int) sdp->device->type, &sg_idp->scsi_type);
948 __put_user((short) sdp->device->host->cmd_per_lun,
949 &sg_idp->h_cmd_per_lun);
950 __put_user((short) sdp->device->queue_depth,
951 &sg_idp->d_queue_depth);
952 __put_user(0, &sg_idp->unused[0]);
953 __put_user(0, &sg_idp->unused[1]);
954 return 0;
955 }
956 case SG_SET_FORCE_PACK_ID:
957 result = get_user(val, ip);
958 if (result)
959 return result;
960 sfp->force_packid = val ? 1 : 0;
961 return 0;
962 case SG_GET_PACK_ID:
963 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
964 return -EFAULT;
965 read_lock_irqsave(&sfp->rq_list_lock, iflags);
966 list_for_each_entry(srp, &sfp->rq_list, entry) {
967 if ((1 == srp->done) && (!srp->sg_io_owned)) {
968 read_unlock_irqrestore(&sfp->rq_list_lock,
969 iflags);
970 __put_user(srp->header.pack_id, ip);
971 return 0;
972 }
973 }
974 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
975 __put_user(-1, ip);
976 return 0;
977 case SG_GET_NUM_WAITING:
978 read_lock_irqsave(&sfp->rq_list_lock, iflags);
979 val = 0;
980 list_for_each_entry(srp, &sfp->rq_list, entry) {
981 if ((1 == srp->done) && (!srp->sg_io_owned))
982 ++val;
983 }
984 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
985 return put_user(val, ip);
986 case SG_GET_SG_TABLESIZE:
987 return put_user(sdp->sg_tablesize, ip);
988 case SG_SET_RESERVED_SIZE:
989 result = get_user(val, ip);
990 if (result)
991 return result;
992 if (val < 0)
993 return -EINVAL;
994 val = min_t(int, val,
995 max_sectors_bytes(sdp->device->request_queue));
996 mutex_lock(&sfp->f_mutex);
997 if (val != sfp->reserve.bufflen) {
998 if (sfp->mmap_called ||
999 sfp->res_in_use) {
1000 mutex_unlock(&sfp->f_mutex);
1001 return -EBUSY;
1002 }
1003
1004 sg_remove_scat(sfp, &sfp->reserve);
1005 sg_build_reserve(sfp, val);
1006 }
1007 mutex_unlock(&sfp->f_mutex);
1008 return 0;
1009 case SG_GET_RESERVED_SIZE:
1010 val = min_t(int, sfp->reserve.bufflen,
1011 max_sectors_bytes(sdp->device->request_queue));
1012 return put_user(val, ip);
1013 case SG_SET_COMMAND_Q:
1014 result = get_user(val, ip);
1015 if (result)
1016 return result;
1017 sfp->cmd_q = val ? 1 : 0;
1018 return 0;
1019 case SG_GET_COMMAND_Q:
1020 return put_user((int) sfp->cmd_q, ip);
1021 case SG_SET_KEEP_ORPHAN:
1022 result = get_user(val, ip);
1023 if (result)
1024 return result;
1025 sfp->keep_orphan = val;
1026 return 0;
1027 case SG_GET_KEEP_ORPHAN:
1028 return put_user((int) sfp->keep_orphan, ip);
1029 case SG_NEXT_CMD_LEN:
1030 result = get_user(val, ip);
1031 if (result)
1032 return result;
1033 if (val > SG_MAX_CDB_SIZE)
1034 return -ENOMEM;
1035 sfp->next_cmd_len = (val > 0) ? val : 0;
1036 return 0;
1037 case SG_GET_VERSION_NUM:
1038 return put_user(sg_version_num, ip);
1039 case SG_GET_ACCESS_COUNT:
1040 /* faked - we don't have a real access count anymore */
1041 val = (sdp->device ? 1 : 0);
1042 return put_user(val, ip);
1043 case SG_GET_REQUEST_TABLE:
1044 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
1045 return -EFAULT;
1046 else {
1047 sg_req_info_t *rinfo;
1048
1049 rinfo = kzalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
1050 GFP_KERNEL);
1051 if (!rinfo)
1052 return -ENOMEM;
1053 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1054 sg_fill_request_table(sfp, rinfo);
1055 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1056 result = __copy_to_user(p, rinfo,
1057 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1058 result = result ? -EFAULT : 0;
1059 kfree(rinfo);
1060 return result;
1061 }
1062 case SG_EMULATED_HOST:
1063 if (atomic_read(&sdp->detaching))
1064 return -ENODEV;
1065 return put_user(sdp->device->host->hostt->emulated, ip);
1066 case SCSI_IOCTL_SEND_COMMAND:
1067 if (atomic_read(&sdp->detaching))
1068 return -ENODEV;
1069 if (read_only) {
1070 unsigned char opcode = WRITE_6;
1071 Scsi_Ioctl_Command __user *siocp = p;
1072
1073 if (copy_from_user(&opcode, siocp->data, 1))
1074 return -EFAULT;
1075 if (sg_allow_access(filp, &opcode))
1076 return -EPERM;
1077 }
1078 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1079 case SG_SET_DEBUG:
1080 result = get_user(val, ip);
1081 if (result)
1082 return result;
1083 sdp->sgdebug = (char) val;
1084 return 0;
1085 case BLKSECTGET:
1086 return put_user(max_sectors_bytes(sdp->device->request_queue),
1087 ip);
1088 case BLKTRACESETUP:
1089 return blk_trace_setup(sdp->device->request_queue,
1090 sdp->disk->disk_name,
1091 MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1092 NULL, p);
1093 case BLKTRACESTART:
1094 return blk_trace_startstop(sdp->device->request_queue, 1);
1095 case BLKTRACESTOP:
1096 return blk_trace_startstop(sdp->device->request_queue, 0);
1097 case BLKTRACETEARDOWN:
1098 return blk_trace_remove(sdp->device->request_queue);
1099 case SCSI_IOCTL_GET_IDLUN:
1100 case SCSI_IOCTL_GET_BUS_NUMBER:
1101 case SCSI_IOCTL_PROBE_HOST:
1102 case SG_GET_TRANSFORM:
1103 case SG_SCSI_RESET:
1104 if (atomic_read(&sdp->detaching))
1105 return -ENODEV;
1106 break;
1107 default:
1108 if (read_only)
1109 return -EPERM; /* don't know so take safe approach */
1110 break;
1111 }
1112
1113 result = scsi_ioctl_block_when_processing_errors(sdp->device,
1114 cmd_in, filp->f_flags & O_NDELAY);
1115 if (result)
1116 return result;
1117 return scsi_ioctl(sdp->device, cmd_in, p);
1118}
1119
1120#ifdef CONFIG_COMPAT
1121static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1122{
1123 Sg_device *sdp;
1124 Sg_fd *sfp;
1125 struct scsi_device *sdev;
1126
1127 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1128 return -ENXIO;
1129
1130 sdev = sdp->device;
1131 if (sdev->host->hostt->compat_ioctl) {
1132 int ret;
1133
1134 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1135
1136 return ret;
1137 }
1138
1139 return -ENOIOCTLCMD;
1140}
1141#endif
1142
1143static __poll_t
1144sg_poll(struct file *filp, poll_table * wait)
1145{
1146 __poll_t res = 0;
1147 Sg_device *sdp;
1148 Sg_fd *sfp;
1149 Sg_request *srp;
1150 int count = 0;
1151 unsigned long iflags;
1152
1153 sfp = filp->private_data;
1154 if (!sfp)
1155 return EPOLLERR;
1156 sdp = sfp->parentdp;
1157 if (!sdp)
1158 return EPOLLERR;
1159 poll_wait(filp, &sfp->read_wait, wait);
1160 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1161 list_for_each_entry(srp, &sfp->rq_list, entry) {
1162 /* if any read waiting, flag it */
1163 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1164 res = EPOLLIN | EPOLLRDNORM;
1165 ++count;
1166 }
1167 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1168
1169 if (atomic_read(&sdp->detaching))
1170 res |= EPOLLHUP;
1171 else if (!sfp->cmd_q) {
1172 if (0 == count)
1173 res |= EPOLLOUT | EPOLLWRNORM;
1174 } else if (count < SG_MAX_QUEUE)
1175 res |= EPOLLOUT | EPOLLWRNORM;
1176 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1177 "sg_poll: res=0x%x\n", (__force u32) res));
1178 return res;
1179}
1180
1181static int
1182sg_fasync(int fd, struct file *filp, int mode)
1183{
1184 Sg_device *sdp;
1185 Sg_fd *sfp;
1186
1187 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1188 return -ENXIO;
1189 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1190 "sg_fasync: mode=%d\n", mode));
1191
1192 return fasync_helper(fd, filp, mode, &sfp->async_qp);
1193}
1194
1195static int
1196sg_vma_fault(struct vm_fault *vmf)
1197{
1198 struct vm_area_struct *vma = vmf->vma;
1199 Sg_fd *sfp;
1200 unsigned long offset, len, sa;
1201 Sg_scatter_hold *rsv_schp;
1202 int k, length;
1203
1204 if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1205 return VM_FAULT_SIGBUS;
1206 rsv_schp = &sfp->reserve;
1207 offset = vmf->pgoff << PAGE_SHIFT;
1208 if (offset >= rsv_schp->bufflen)
1209 return VM_FAULT_SIGBUS;
1210 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1211 "sg_vma_fault: offset=%lu, scatg=%d\n",
1212 offset, rsv_schp->k_use_sg));
1213 sa = vma->vm_start;
1214 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1215 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1216 len = vma->vm_end - sa;
1217 len = (len < length) ? len : length;
1218 if (offset < len) {
1219 struct page *page = nth_page(rsv_schp->pages[k],
1220 offset >> PAGE_SHIFT);
1221 get_page(page); /* increment page count */
1222 vmf->page = page;
1223 return 0; /* success */
1224 }
1225 sa += len;
1226 offset -= len;
1227 }
1228
1229 return VM_FAULT_SIGBUS;
1230}
1231
1232static const struct vm_operations_struct sg_mmap_vm_ops = {
1233 .fault = sg_vma_fault,
1234};
1235
1236static int
1237sg_mmap(struct file *filp, struct vm_area_struct *vma)
1238{
1239 Sg_fd *sfp;
1240 unsigned long req_sz, len, sa;
1241 Sg_scatter_hold *rsv_schp;
1242 int k, length;
1243 int ret = 0;
1244
1245 if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1246 return -ENXIO;
1247 req_sz = vma->vm_end - vma->vm_start;
1248 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1249 "sg_mmap starting, vm_start=%p, len=%d\n",
1250 (void *) vma->vm_start, (int) req_sz));
1251 if (vma->vm_pgoff)
1252 return -EINVAL; /* want no offset */
1253 rsv_schp = &sfp->reserve;
1254 mutex_lock(&sfp->f_mutex);
1255 if (req_sz > rsv_schp->bufflen) {
1256 ret = -ENOMEM; /* cannot map more than reserved buffer */
1257 goto out;
1258 }
1259
1260 sa = vma->vm_start;
1261 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1262 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1263 len = vma->vm_end - sa;
1264 len = (len < length) ? len : length;
1265 sa += len;
1266 }
1267
1268 sfp->mmap_called = 1;
1269 vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
1270 vma->vm_private_data = sfp;
1271 vma->vm_ops = &sg_mmap_vm_ops;
1272out:
1273 mutex_unlock(&sfp->f_mutex);
1274 return ret;
1275}
1276
1277static void
1278sg_rq_end_io_usercontext(struct work_struct *work)
1279{
1280 struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1281 struct sg_fd *sfp = srp->parentfp;
1282
1283 sg_finish_rem_req(srp);
1284 sg_remove_request(sfp, srp);
1285 kref_put(&sfp->f_ref, sg_remove_sfp);
1286}
1287
1288/*
1289 * This function is a "bottom half" handler that is called by the mid
1290 * level when a command is completed (or has failed).
1291 */
1292static void
1293sg_rq_end_io(struct request *rq, blk_status_t status)
1294{
1295 struct sg_request *srp = rq->end_io_data;
1296 struct scsi_request *req = scsi_req(rq);
1297 Sg_device *sdp;
1298 Sg_fd *sfp;
1299 unsigned long iflags;
1300 unsigned int ms;
1301 char *sense;
1302 int result, resid, done = 1;
1303
1304 if (WARN_ON(srp->done != 0))
1305 return;
1306
1307 sfp = srp->parentfp;
1308 if (WARN_ON(sfp == NULL))
1309 return;
1310
1311 sdp = sfp->parentdp;
1312 if (unlikely(atomic_read(&sdp->detaching)))
1313 pr_info("%s: device detaching\n", __func__);
1314
1315 sense = req->sense;
1316 result = req->result;
1317 resid = req->resid_len;
1318
1319 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1320 "sg_cmd_done: pack_id=%d, res=0x%x\n",
1321 srp->header.pack_id, result));
1322 srp->header.resid = resid;
1323 ms = jiffies_to_msecs(jiffies);
1324 srp->header.duration = (ms > srp->header.duration) ?
1325 (ms - srp->header.duration) : 0;
1326 if (0 != result) {
1327 struct scsi_sense_hdr sshdr;
1328
1329 srp->header.status = 0xff & result;
1330 srp->header.masked_status = status_byte(result);
1331 srp->header.msg_status = msg_byte(result);
1332 srp->header.host_status = host_byte(result);
1333 srp->header.driver_status = driver_byte(result);
1334 if ((sdp->sgdebug > 0) &&
1335 ((CHECK_CONDITION == srp->header.masked_status) ||
1336 (COMMAND_TERMINATED == srp->header.masked_status)))
1337 __scsi_print_sense(sdp->device, __func__, sense,
1338 SCSI_SENSE_BUFFERSIZE);
1339
1340 /* Following if statement is a patch supplied by Eric Youngdale */
1341 if (driver_byte(result) != 0
1342 && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1343 && !scsi_sense_is_deferred(&sshdr)
1344 && sshdr.sense_key == UNIT_ATTENTION
1345 && sdp->device->removable) {
1346 /* Detected possible disc change. Set the bit - this */
1347 /* may be used if there are filesystems using this device */
1348 sdp->device->changed = 1;
1349 }
1350 }
1351
1352 if (req->sense_len)
1353 memcpy(srp->sense_b, req->sense, SCSI_SENSE_BUFFERSIZE);
1354
1355 /* Rely on write phase to clean out srp status values, so no "else" */
1356
1357 /*
1358 * Free the request as soon as it is complete so that its resources
1359 * can be reused without waiting for userspace to read() the
1360 * result. But keep the associated bio (if any) around until
1361 * blk_rq_unmap_user() can be called from user context.
1362 */
1363 srp->rq = NULL;
1364 scsi_req_free_cmd(scsi_req(rq));
1365 __blk_put_request(rq->q, rq);
1366
1367 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1368 if (unlikely(srp->orphan)) {
1369 if (sfp->keep_orphan)
1370 srp->sg_io_owned = 0;
1371 else
1372 done = 0;
1373 }
1374 srp->done = done;
1375 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1376
1377 if (likely(done)) {
1378 /* Now wake up any sg_read() that is waiting for this
1379 * packet.
1380 */
1381 wake_up_interruptible(&sfp->read_wait);
1382 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1383 kref_put(&sfp->f_ref, sg_remove_sfp);
1384 } else {
1385 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1386 schedule_work(&srp->ew.work);
1387 }
1388}
1389
1390static const struct file_operations sg_fops = {
1391 .owner = THIS_MODULE,
1392 .read = sg_read,
1393 .write = sg_write,
1394 .poll = sg_poll,
1395 .unlocked_ioctl = sg_ioctl,
1396#ifdef CONFIG_COMPAT
1397 .compat_ioctl = sg_compat_ioctl,
1398#endif
1399 .open = sg_open,
1400 .mmap = sg_mmap,
1401 .release = sg_release,
1402 .fasync = sg_fasync,
1403 .llseek = no_llseek,
1404};
1405
1406static struct class *sg_sysfs_class;
1407
1408static int sg_sysfs_valid = 0;
1409
1410static Sg_device *
1411sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1412{
1413 struct request_queue *q = scsidp->request_queue;
1414 Sg_device *sdp;
1415 unsigned long iflags;
1416 int error;
1417 u32 k;
1418
1419 sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1420 if (!sdp) {
1421 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1422 "failure\n", __func__);
1423 return ERR_PTR(-ENOMEM);
1424 }
1425
1426 idr_preload(GFP_KERNEL);
1427 write_lock_irqsave(&sg_index_lock, iflags);
1428
1429 error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1430 if (error < 0) {
1431 if (error == -ENOSPC) {
1432 sdev_printk(KERN_WARNING, scsidp,
1433 "Unable to attach sg device type=%d, minor number exceeds %d\n",
1434 scsidp->type, SG_MAX_DEVS - 1);
1435 error = -ENODEV;
1436 } else {
1437 sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1438 "allocation Sg_device failure: %d\n",
1439 __func__, error);
1440 }
1441 goto out_unlock;
1442 }
1443 k = error;
1444
1445 SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1446 "sg_alloc: dev=%d \n", k));
1447 sprintf(disk->disk_name, "sg%d", k);
1448 disk->first_minor = k;
1449 sdp->disk = disk;
1450 sdp->device = scsidp;
1451 mutex_init(&sdp->open_rel_lock);
1452 INIT_LIST_HEAD(&sdp->sfds);
1453 init_waitqueue_head(&sdp->open_wait);
1454 atomic_set(&sdp->detaching, 0);
1455 rwlock_init(&sdp->sfd_lock);
1456 sdp->sg_tablesize = queue_max_segments(q);
1457 sdp->index = k;
1458 kref_init(&sdp->d_ref);
1459 error = 0;
1460
1461out_unlock:
1462 write_unlock_irqrestore(&sg_index_lock, iflags);
1463 idr_preload_end();
1464
1465 if (error) {
1466 kfree(sdp);
1467 return ERR_PTR(error);
1468 }
1469 return sdp;
1470}
1471
1472static int
1473sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
1474{
1475 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1476 struct gendisk *disk;
1477 Sg_device *sdp = NULL;
1478 struct cdev * cdev = NULL;
1479 int error;
1480 unsigned long iflags;
1481
1482 disk = alloc_disk(1);
1483 if (!disk) {
1484 pr_warn("%s: alloc_disk failed\n", __func__);
1485 return -ENOMEM;
1486 }
1487 disk->major = SCSI_GENERIC_MAJOR;
1488
1489 error = -ENOMEM;
1490 cdev = cdev_alloc();
1491 if (!cdev) {
1492 pr_warn("%s: cdev_alloc failed\n", __func__);
1493 goto out;
1494 }
1495 cdev->owner = THIS_MODULE;
1496 cdev->ops = &sg_fops;
1497
1498 sdp = sg_alloc(disk, scsidp);
1499 if (IS_ERR(sdp)) {
1500 pr_warn("%s: sg_alloc failed\n", __func__);
1501 error = PTR_ERR(sdp);
1502 goto out;
1503 }
1504
1505 error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1506 if (error)
1507 goto cdev_add_err;
1508
1509 sdp->cdev = cdev;
1510 if (sg_sysfs_valid) {
1511 struct device *sg_class_member;
1512
1513 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1514 MKDEV(SCSI_GENERIC_MAJOR,
1515 sdp->index),
1516 sdp, "%s", disk->disk_name);
1517 if (IS_ERR(sg_class_member)) {
1518 pr_err("%s: device_create failed\n", __func__);
1519 error = PTR_ERR(sg_class_member);
1520 goto cdev_add_err;
1521 }
1522 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1523 &sg_class_member->kobj, "generic");
1524 if (error)
1525 pr_err("%s: unable to make symlink 'generic' back "
1526 "to sg%d\n", __func__, sdp->index);
1527 } else
1528 pr_warn("%s: sg_sys Invalid\n", __func__);
1529
1530 sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1531 "type %d\n", sdp->index, scsidp->type);
1532
1533 dev_set_drvdata(cl_dev, sdp);
1534
1535 return 0;
1536
1537cdev_add_err:
1538 write_lock_irqsave(&sg_index_lock, iflags);
1539 idr_remove(&sg_index_idr, sdp->index);
1540 write_unlock_irqrestore(&sg_index_lock, iflags);
1541 kfree(sdp);
1542
1543out:
1544 put_disk(disk);
1545 if (cdev)
1546 cdev_del(cdev);
1547 return error;
1548}
1549
1550static void
1551sg_device_destroy(struct kref *kref)
1552{
1553 struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1554 unsigned long flags;
1555
1556 /* CAUTION! Note that the device can still be found via idr_find()
1557 * even though the refcount is 0. Therefore, do idr_remove() BEFORE
1558 * any other cleanup.
1559 */
1560
1561 write_lock_irqsave(&sg_index_lock, flags);
1562 idr_remove(&sg_index_idr, sdp->index);
1563 write_unlock_irqrestore(&sg_index_lock, flags);
1564
1565 SCSI_LOG_TIMEOUT(3,
1566 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1567
1568 put_disk(sdp->disk);
1569 kfree(sdp);
1570}
1571
1572static void
1573sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
1574{
1575 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1576 Sg_device *sdp = dev_get_drvdata(cl_dev);
1577 unsigned long iflags;
1578 Sg_fd *sfp;
1579 int val;
1580
1581 if (!sdp)
1582 return;
1583 /* want sdp->detaching non-zero as soon as possible */
1584 val = atomic_inc_return(&sdp->detaching);
1585 if (val > 1)
1586 return; /* only want to do following once per device */
1587
1588 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1589 "%s\n", __func__));
1590
1591 read_lock_irqsave(&sdp->sfd_lock, iflags);
1592 list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1593 wake_up_interruptible_all(&sfp->read_wait);
1594 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1595 }
1596 wake_up_interruptible_all(&sdp->open_wait);
1597 read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1598
1599 sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1600 device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1601 cdev_del(sdp->cdev);
1602 sdp->cdev = NULL;
1603
1604 kref_put(&sdp->d_ref, sg_device_destroy);
1605}
1606
1607module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1608module_param_named(def_reserved_size, def_reserved_size, int,
1609 S_IRUGO | S_IWUSR);
1610module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1611
1612MODULE_AUTHOR("Douglas Gilbert");
1613MODULE_DESCRIPTION("SCSI generic (sg) driver");
1614MODULE_LICENSE("GPL");
1615MODULE_VERSION(SG_VERSION_STR);
1616MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1617
1618MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1619 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1620MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1621MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1622
1623static int __init
1624init_sg(void)
1625{
1626 int rc;
1627
1628 if (scatter_elem_sz < PAGE_SIZE) {
1629 scatter_elem_sz = PAGE_SIZE;
1630 scatter_elem_sz_prev = scatter_elem_sz;
1631 }
1632 if (def_reserved_size >= 0)
1633 sg_big_buff = def_reserved_size;
1634 else
1635 def_reserved_size = sg_big_buff;
1636
1637 rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1638 SG_MAX_DEVS, "sg");
1639 if (rc)
1640 return rc;
1641 sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1642 if ( IS_ERR(sg_sysfs_class) ) {
1643 rc = PTR_ERR(sg_sysfs_class);
1644 goto err_out;
1645 }
1646 sg_sysfs_valid = 1;
1647 rc = scsi_register_interface(&sg_interface);
1648 if (0 == rc) {
1649#ifdef CONFIG_SCSI_PROC_FS
1650 sg_proc_init();
1651#endif /* CONFIG_SCSI_PROC_FS */
1652 return 0;
1653 }
1654 class_destroy(sg_sysfs_class);
1655err_out:
1656 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1657 return rc;
1658}
1659
1660static void __exit
1661exit_sg(void)
1662{
1663#ifdef CONFIG_SCSI_PROC_FS
1664 sg_proc_cleanup();
1665#endif /* CONFIG_SCSI_PROC_FS */
1666 scsi_unregister_interface(&sg_interface);
1667 class_destroy(sg_sysfs_class);
1668 sg_sysfs_valid = 0;
1669 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1670 SG_MAX_DEVS);
1671 idr_destroy(&sg_index_idr);
1672}
1673
1674static int
1675sg_start_req(Sg_request *srp, unsigned char *cmd)
1676{
1677 int res;
1678 struct request *rq;
1679 struct scsi_request *req;
1680 Sg_fd *sfp = srp->parentfp;
1681 sg_io_hdr_t *hp = &srp->header;
1682 int dxfer_len = (int) hp->dxfer_len;
1683 int dxfer_dir = hp->dxfer_direction;
1684 unsigned int iov_count = hp->iovec_count;
1685 Sg_scatter_hold *req_schp = &srp->data;
1686 Sg_scatter_hold *rsv_schp = &sfp->reserve;
1687 struct request_queue *q = sfp->parentdp->device->request_queue;
1688 struct rq_map_data *md, map_data;
1689 int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1690 unsigned char *long_cmdp = NULL;
1691
1692 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1693 "sg_start_req: dxfer_len=%d\n",
1694 dxfer_len));
1695
1696 if (hp->cmd_len > BLK_MAX_CDB) {
1697 long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
1698 if (!long_cmdp)
1699 return -ENOMEM;
1700 }
1701
1702 /*
1703 * NOTE
1704 *
1705 * With scsi-mq enabled, there are a fixed number of preallocated
1706 * requests equal in number to shost->can_queue. If all of the
1707 * preallocated requests are already in use, then using GFP_ATOMIC with
1708 * blk_get_request() will return -EWOULDBLOCK, whereas using GFP_KERNEL
1709 * will cause blk_get_request() to sleep until an active command
1710 * completes, freeing up a request. Neither option is ideal, but
1711 * GFP_KERNEL is the better choice to prevent userspace from getting an
1712 * unexpected EWOULDBLOCK.
1713 *
1714 * With scsi-mq disabled, blk_get_request() with GFP_KERNEL usually
1715 * does not sleep except under memory pressure.
1716 */
1717 rq = blk_get_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
1718 REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, GFP_KERNEL);
1719 if (IS_ERR(rq)) {
1720 kfree(long_cmdp);
1721 return PTR_ERR(rq);
1722 }
1723 req = scsi_req(rq);
1724
1725 if (hp->cmd_len > BLK_MAX_CDB)
1726 req->cmd = long_cmdp;
1727 memcpy(req->cmd, cmd, hp->cmd_len);
1728 req->cmd_len = hp->cmd_len;
1729
1730 srp->rq = rq;
1731 rq->end_io_data = srp;
1732 req->retries = SG_DEFAULT_RETRIES;
1733
1734 if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1735 return 0;
1736
1737 if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1738 dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1739 !sfp->parentdp->device->host->unchecked_isa_dma &&
1740 blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1741 md = NULL;
1742 else
1743 md = &map_data;
1744
1745 if (md) {
1746 mutex_lock(&sfp->f_mutex);
1747 if (dxfer_len <= rsv_schp->bufflen &&
1748 !sfp->res_in_use) {
1749 sfp->res_in_use = 1;
1750 sg_link_reserve(sfp, srp, dxfer_len);
1751 } else if (hp->flags & SG_FLAG_MMAP_IO) {
1752 res = -EBUSY; /* sfp->res_in_use == 1 */
1753 if (dxfer_len > rsv_schp->bufflen)
1754 res = -ENOMEM;
1755 mutex_unlock(&sfp->f_mutex);
1756 return res;
1757 } else {
1758 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1759 if (res) {
1760 mutex_unlock(&sfp->f_mutex);
1761 return res;
1762 }
1763 }
1764 mutex_unlock(&sfp->f_mutex);
1765
1766 md->pages = req_schp->pages;
1767 md->page_order = req_schp->page_order;
1768 md->nr_entries = req_schp->k_use_sg;
1769 md->offset = 0;
1770 md->null_mapped = hp->dxferp ? 0 : 1;
1771 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1772 md->from_user = 1;
1773 else
1774 md->from_user = 0;
1775 }
1776
1777 if (iov_count) {
1778 struct iovec *iov = NULL;
1779 struct iov_iter i;
1780
1781 res = import_iovec(rw, hp->dxferp, iov_count, 0, &iov, &i);
1782 if (res < 0)
1783 return res;
1784
1785 iov_iter_truncate(&i, hp->dxfer_len);
1786 if (!iov_iter_count(&i)) {
1787 kfree(iov);
1788 return -EINVAL;
1789 }
1790
1791 res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
1792 kfree(iov);
1793 } else
1794 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1795 hp->dxfer_len, GFP_ATOMIC);
1796
1797 if (!res) {
1798 srp->bio = rq->bio;
1799
1800 if (!md) {
1801 req_schp->dio_in_use = 1;
1802 hp->info |= SG_INFO_DIRECT_IO;
1803 }
1804 }
1805 return res;
1806}
1807
1808static int
1809sg_finish_rem_req(Sg_request *srp)
1810{
1811 int ret = 0;
1812
1813 Sg_fd *sfp = srp->parentfp;
1814 Sg_scatter_hold *req_schp = &srp->data;
1815
1816 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1817 "sg_finish_rem_req: res_used=%d\n",
1818 (int) srp->res_used));
1819 if (srp->bio)
1820 ret = blk_rq_unmap_user(srp->bio);
1821
1822 if (srp->rq) {
1823 scsi_req_free_cmd(scsi_req(srp->rq));
1824 blk_put_request(srp->rq);
1825 }
1826
1827 if (srp->res_used)
1828 sg_unlink_reserve(sfp, srp);
1829 else
1830 sg_remove_scat(sfp, req_schp);
1831
1832 return ret;
1833}
1834
1835static int
1836sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1837{
1838 int sg_bufflen = tablesize * sizeof(struct page *);
1839 gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1840
1841 schp->pages = kzalloc(sg_bufflen, gfp_flags);
1842 if (!schp->pages)
1843 return -ENOMEM;
1844 schp->sglist_len = sg_bufflen;
1845 return tablesize; /* number of scat_gath elements allocated */
1846}
1847
1848static int
1849sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1850{
1851 int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1852 int sg_tablesize = sfp->parentdp->sg_tablesize;
1853 int blk_size = buff_size, order;
1854 gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1855 struct sg_device *sdp = sfp->parentdp;
1856
1857 if (blk_size < 0)
1858 return -EFAULT;
1859 if (0 == blk_size)
1860 ++blk_size; /* don't know why */
1861 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1862 blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1863 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1864 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1865 buff_size, blk_size));
1866
1867 /* N.B. ret_sz carried into this block ... */
1868 mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1869 if (mx_sc_elems < 0)
1870 return mx_sc_elems; /* most likely -ENOMEM */
1871
1872 num = scatter_elem_sz;
1873 if (unlikely(num != scatter_elem_sz_prev)) {
1874 if (num < PAGE_SIZE) {
1875 scatter_elem_sz = PAGE_SIZE;
1876 scatter_elem_sz_prev = PAGE_SIZE;
1877 } else
1878 scatter_elem_sz_prev = num;
1879 }
1880
1881 if (sdp->device->host->unchecked_isa_dma)
1882 gfp_mask |= GFP_DMA;
1883
1884 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1885 gfp_mask |= __GFP_ZERO;
1886
1887 order = get_order(num);
1888retry:
1889 ret_sz = 1 << (PAGE_SHIFT + order);
1890
1891 for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1892 k++, rem_sz -= ret_sz) {
1893
1894 num = (rem_sz > scatter_elem_sz_prev) ?
1895 scatter_elem_sz_prev : rem_sz;
1896
1897 schp->pages[k] = alloc_pages(gfp_mask | __GFP_ZERO, order);
1898 if (!schp->pages[k])
1899 goto out;
1900
1901 if (num == scatter_elem_sz_prev) {
1902 if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1903 scatter_elem_sz = ret_sz;
1904 scatter_elem_sz_prev = ret_sz;
1905 }
1906 }
1907
1908 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1909 "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1910 k, num, ret_sz));
1911 } /* end of for loop */
1912
1913 schp->page_order = order;
1914 schp->k_use_sg = k;
1915 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1916 "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1917 k, rem_sz));
1918
1919 schp->bufflen = blk_size;
1920 if (rem_sz > 0) /* must have failed */
1921 return -ENOMEM;
1922 return 0;
1923out:
1924 for (i = 0; i < k; i++)
1925 __free_pages(schp->pages[i], order);
1926
1927 if (--order >= 0)
1928 goto retry;
1929
1930 return -ENOMEM;
1931}
1932
1933static void
1934sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1935{
1936 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1937 "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1938 if (schp->pages && schp->sglist_len > 0) {
1939 if (!schp->dio_in_use) {
1940 int k;
1941
1942 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1943 SCSI_LOG_TIMEOUT(5,
1944 sg_printk(KERN_INFO, sfp->parentdp,
1945 "sg_remove_scat: k=%d, pg=0x%p\n",
1946 k, schp->pages[k]));
1947 __free_pages(schp->pages[k], schp->page_order);
1948 }
1949
1950 kfree(schp->pages);
1951 }
1952 }
1953 memset(schp, 0, sizeof (*schp));
1954}
1955
1956static int
1957sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1958{
1959 Sg_scatter_hold *schp = &srp->data;
1960 int k, num;
1961
1962 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1963 "sg_read_oxfer: num_read_xfer=%d\n",
1964 num_read_xfer));
1965 if ((!outp) || (num_read_xfer <= 0))
1966 return 0;
1967
1968 num = 1 << (PAGE_SHIFT + schp->page_order);
1969 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1970 if (num > num_read_xfer) {
1971 if (__copy_to_user(outp, page_address(schp->pages[k]),
1972 num_read_xfer))
1973 return -EFAULT;
1974 break;
1975 } else {
1976 if (__copy_to_user(outp, page_address(schp->pages[k]),
1977 num))
1978 return -EFAULT;
1979 num_read_xfer -= num;
1980 if (num_read_xfer <= 0)
1981 break;
1982 outp += num;
1983 }
1984 }
1985
1986 return 0;
1987}
1988
1989static void
1990sg_build_reserve(Sg_fd * sfp, int req_size)
1991{
1992 Sg_scatter_hold *schp = &sfp->reserve;
1993
1994 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1995 "sg_build_reserve: req_size=%d\n", req_size));
1996 do {
1997 if (req_size < PAGE_SIZE)
1998 req_size = PAGE_SIZE;
1999 if (0 == sg_build_indirect(schp, sfp, req_size))
2000 return;
2001 else
2002 sg_remove_scat(sfp, schp);
2003 req_size >>= 1; /* divide by 2 */
2004 } while (req_size > (PAGE_SIZE / 2));
2005}
2006
2007static void
2008sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2009{
2010 Sg_scatter_hold *req_schp = &srp->data;
2011 Sg_scatter_hold *rsv_schp = &sfp->reserve;
2012 int k, num, rem;
2013
2014 srp->res_used = 1;
2015 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2016 "sg_link_reserve: size=%d\n", size));
2017 rem = size;
2018
2019 num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
2020 for (k = 0; k < rsv_schp->k_use_sg; k++) {
2021 if (rem <= num) {
2022 req_schp->k_use_sg = k + 1;
2023 req_schp->sglist_len = rsv_schp->sglist_len;
2024 req_schp->pages = rsv_schp->pages;
2025
2026 req_schp->bufflen = size;
2027 req_schp->page_order = rsv_schp->page_order;
2028 break;
2029 } else
2030 rem -= num;
2031 }
2032
2033 if (k >= rsv_schp->k_use_sg)
2034 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2035 "sg_link_reserve: BAD size\n"));
2036}
2037
2038static void
2039sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2040{
2041 Sg_scatter_hold *req_schp = &srp->data;
2042
2043 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2044 "sg_unlink_reserve: req->k_use_sg=%d\n",
2045 (int) req_schp->k_use_sg));
2046 req_schp->k_use_sg = 0;
2047 req_schp->bufflen = 0;
2048 req_schp->pages = NULL;
2049 req_schp->page_order = 0;
2050 req_schp->sglist_len = 0;
2051 srp->res_used = 0;
2052 /* Called without mutex lock to avoid deadlock */
2053 sfp->res_in_use = 0;
2054}
2055
2056static Sg_request *
2057sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2058{
2059 Sg_request *resp;
2060 unsigned long iflags;
2061
2062 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2063 list_for_each_entry(resp, &sfp->rq_list, entry) {
2064 /* look for requests that are ready + not SG_IO owned */
2065 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2066 ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2067 resp->done = 2; /* guard against other readers */
2068 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2069 return resp;
2070 }
2071 }
2072 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2073 return NULL;
2074}
2075
2076/* always adds to end of list */
2077static Sg_request *
2078sg_add_request(Sg_fd * sfp)
2079{
2080 int k;
2081 unsigned long iflags;
2082 Sg_request *rp = sfp->req_arr;
2083
2084 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2085 if (!list_empty(&sfp->rq_list)) {
2086 if (!sfp->cmd_q)
2087 goto out_unlock;
2088
2089 for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2090 if (!rp->parentfp)
2091 break;
2092 }
2093 if (k >= SG_MAX_QUEUE)
2094 goto out_unlock;
2095 }
2096 memset(rp, 0, sizeof (Sg_request));
2097 rp->parentfp = sfp;
2098 rp->header.duration = jiffies_to_msecs(jiffies);
2099 list_add_tail(&rp->entry, &sfp->rq_list);
2100 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2101 return rp;
2102out_unlock:
2103 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2104 return NULL;
2105}
2106
2107/* Return of 1 for found; 0 for not found */
2108static int
2109sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2110{
2111 unsigned long iflags;
2112 int res = 0;
2113
2114 if (!sfp || !srp || list_empty(&sfp->rq_list))
2115 return res;
2116 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2117 if (!list_empty(&srp->entry)) {
2118 list_del(&srp->entry);
2119 srp->parentfp = NULL;
2120 res = 1;
2121 }
2122 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2123 return res;
2124}
2125
2126static Sg_fd *
2127sg_add_sfp(Sg_device * sdp)
2128{
2129 Sg_fd *sfp;
2130 unsigned long iflags;
2131 int bufflen;
2132
2133 sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2134 if (!sfp)
2135 return ERR_PTR(-ENOMEM);
2136
2137 init_waitqueue_head(&sfp->read_wait);
2138 rwlock_init(&sfp->rq_list_lock);
2139 INIT_LIST_HEAD(&sfp->rq_list);
2140 kref_init(&sfp->f_ref);
2141 mutex_init(&sfp->f_mutex);
2142 sfp->timeout = SG_DEFAULT_TIMEOUT;
2143 sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2144 sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2145 sfp->cmd_q = SG_DEF_COMMAND_Q;
2146 sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2147 sfp->parentdp = sdp;
2148 write_lock_irqsave(&sdp->sfd_lock, iflags);
2149 if (atomic_read(&sdp->detaching)) {
2150 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2151 return ERR_PTR(-ENODEV);
2152 }
2153 list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2154 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2155 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2156 "sg_add_sfp: sfp=0x%p\n", sfp));
2157 if (unlikely(sg_big_buff != def_reserved_size))
2158 sg_big_buff = def_reserved_size;
2159
2160 bufflen = min_t(int, sg_big_buff,
2161 max_sectors_bytes(sdp->device->request_queue));
2162 sg_build_reserve(sfp, bufflen);
2163 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2164 "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2165 sfp->reserve.bufflen,
2166 sfp->reserve.k_use_sg));
2167
2168 kref_get(&sdp->d_ref);
2169 __module_get(THIS_MODULE);
2170 return sfp;
2171}
2172
2173static void
2174sg_remove_sfp_usercontext(struct work_struct *work)
2175{
2176 struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2177 struct sg_device *sdp = sfp->parentdp;
2178 Sg_request *srp;
2179 unsigned long iflags;
2180
2181 /* Cleanup any responses which were never read(). */
2182 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2183 while (!list_empty(&sfp->rq_list)) {
2184 srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2185 sg_finish_rem_req(srp);
2186 list_del(&srp->entry);
2187 srp->parentfp = NULL;
2188 }
2189 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2190
2191 if (sfp->reserve.bufflen > 0) {
2192 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2193 "sg_remove_sfp: bufflen=%d, k_use_sg=%d\n",
2194 (int) sfp->reserve.bufflen,
2195 (int) sfp->reserve.k_use_sg));
2196 sg_remove_scat(sfp, &sfp->reserve);
2197 }
2198
2199 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2200 "sg_remove_sfp: sfp=0x%p\n", sfp));
2201 kfree(sfp);
2202
2203 scsi_device_put(sdp->device);
2204 kref_put(&sdp->d_ref, sg_device_destroy);
2205 module_put(THIS_MODULE);
2206}
2207
2208static void
2209sg_remove_sfp(struct kref *kref)
2210{
2211 struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2212 struct sg_device *sdp = sfp->parentdp;
2213 unsigned long iflags;
2214
2215 write_lock_irqsave(&sdp->sfd_lock, iflags);
2216 list_del(&sfp->sfd_siblings);
2217 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2218
2219 INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2220 schedule_work(&sfp->ew.work);
2221}
2222
2223#ifdef CONFIG_SCSI_PROC_FS
2224static int
2225sg_idr_max_id(int id, void *p, void *data)
2226{
2227 int *k = data;
2228
2229 if (*k < id)
2230 *k = id;
2231
2232 return 0;
2233}
2234
2235static int
2236sg_last_dev(void)
2237{
2238 int k = -1;
2239 unsigned long iflags;
2240
2241 read_lock_irqsave(&sg_index_lock, iflags);
2242 idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2243 read_unlock_irqrestore(&sg_index_lock, iflags);
2244 return k + 1; /* origin 1 */
2245}
2246#endif
2247
2248/* must be called with sg_index_lock held */
2249static Sg_device *sg_lookup_dev(int dev)
2250{
2251 return idr_find(&sg_index_idr, dev);
2252}
2253
2254static Sg_device *
2255sg_get_dev(int dev)
2256{
2257 struct sg_device *sdp;
2258 unsigned long flags;
2259
2260 read_lock_irqsave(&sg_index_lock, flags);
2261 sdp = sg_lookup_dev(dev);
2262 if (!sdp)
2263 sdp = ERR_PTR(-ENXIO);
2264 else if (atomic_read(&sdp->detaching)) {
2265 /* If sdp->detaching, then the refcount may already be 0, in
2266 * which case it would be a bug to do kref_get().
2267 */
2268 sdp = ERR_PTR(-ENODEV);
2269 } else
2270 kref_get(&sdp->d_ref);
2271 read_unlock_irqrestore(&sg_index_lock, flags);
2272
2273 return sdp;
2274}
2275
2276#ifdef CONFIG_SCSI_PROC_FS
2277
2278static struct proc_dir_entry *sg_proc_sgp = NULL;
2279
2280static char sg_proc_sg_dirname[] = "scsi/sg";
2281
2282static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2283
2284static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2285static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2286 size_t count, loff_t *off);
2287static const struct file_operations adio_fops = {
2288 .owner = THIS_MODULE,
2289 .open = sg_proc_single_open_adio,
2290 .read = seq_read,
2291 .llseek = seq_lseek,
2292 .write = sg_proc_write_adio,
2293 .release = single_release,
2294};
2295
2296static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2297static ssize_t sg_proc_write_dressz(struct file *filp,
2298 const char __user *buffer, size_t count, loff_t *off);
2299static const struct file_operations dressz_fops = {
2300 .owner = THIS_MODULE,
2301 .open = sg_proc_single_open_dressz,
2302 .read = seq_read,
2303 .llseek = seq_lseek,
2304 .write = sg_proc_write_dressz,
2305 .release = single_release,
2306};
2307
2308static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2309static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2310static const struct file_operations version_fops = {
2311 .owner = THIS_MODULE,
2312 .open = sg_proc_single_open_version,
2313 .read = seq_read,
2314 .llseek = seq_lseek,
2315 .release = single_release,
2316};
2317
2318static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2319static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2320static const struct file_operations devhdr_fops = {
2321 .owner = THIS_MODULE,
2322 .open = sg_proc_single_open_devhdr,
2323 .read = seq_read,
2324 .llseek = seq_lseek,
2325 .release = single_release,
2326};
2327
2328static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2329static int sg_proc_open_dev(struct inode *inode, struct file *file);
2330static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2331static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2332static void dev_seq_stop(struct seq_file *s, void *v);
2333static const struct file_operations dev_fops = {
2334 .owner = THIS_MODULE,
2335 .open = sg_proc_open_dev,
2336 .read = seq_read,
2337 .llseek = seq_lseek,
2338 .release = seq_release,
2339};
2340static const struct seq_operations dev_seq_ops = {
2341 .start = dev_seq_start,
2342 .next = dev_seq_next,
2343 .stop = dev_seq_stop,
2344 .show = sg_proc_seq_show_dev,
2345};
2346
2347static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2348static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2349static const struct file_operations devstrs_fops = {
2350 .owner = THIS_MODULE,
2351 .open = sg_proc_open_devstrs,
2352 .read = seq_read,
2353 .llseek = seq_lseek,
2354 .release = seq_release,
2355};
2356static const struct seq_operations devstrs_seq_ops = {
2357 .start = dev_seq_start,
2358 .next = dev_seq_next,
2359 .stop = dev_seq_stop,
2360 .show = sg_proc_seq_show_devstrs,
2361};
2362
2363static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2364static int sg_proc_open_debug(struct inode *inode, struct file *file);
2365static const struct file_operations debug_fops = {
2366 .owner = THIS_MODULE,
2367 .open = sg_proc_open_debug,
2368 .read = seq_read,
2369 .llseek = seq_lseek,
2370 .release = seq_release,
2371};
2372static const struct seq_operations debug_seq_ops = {
2373 .start = dev_seq_start,
2374 .next = dev_seq_next,
2375 .stop = dev_seq_stop,
2376 .show = sg_proc_seq_show_debug,
2377};
2378
2379
2380struct sg_proc_leaf {
2381 const char * name;
2382 const struct file_operations * fops;
2383};
2384
2385static const struct sg_proc_leaf sg_proc_leaf_arr[] = {
2386 {"allow_dio", &adio_fops},
2387 {"debug", &debug_fops},
2388 {"def_reserved_size", &dressz_fops},
2389 {"device_hdr", &devhdr_fops},
2390 {"devices", &dev_fops},
2391 {"device_strs", &devstrs_fops},
2392 {"version", &version_fops}
2393};
2394
2395static int
2396sg_proc_init(void)
2397{
2398 int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2399 int k;
2400
2401 sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2402 if (!sg_proc_sgp)
2403 return 1;
2404 for (k = 0; k < num_leaves; ++k) {
2405 const struct sg_proc_leaf *leaf = &sg_proc_leaf_arr[k];
2406 umode_t mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2407 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2408 }
2409 return 0;
2410}
2411
2412static void
2413sg_proc_cleanup(void)
2414{
2415 int k;
2416 int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2417
2418 if (!sg_proc_sgp)
2419 return;
2420 for (k = 0; k < num_leaves; ++k)
2421 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2422 remove_proc_entry(sg_proc_sg_dirname, NULL);
2423}
2424
2425
2426static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2427{
2428 seq_printf(s, "%d\n", *((int *)s->private));
2429 return 0;
2430}
2431
2432static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2433{
2434 return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2435}
2436
2437static ssize_t
2438sg_proc_write_adio(struct file *filp, const char __user *buffer,
2439 size_t count, loff_t *off)
2440{
2441 int err;
2442 unsigned long num;
2443
2444 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2445 return -EACCES;
2446 err = kstrtoul_from_user(buffer, count, 0, &num);
2447 if (err)
2448 return err;
2449 sg_allow_dio = num ? 1 : 0;
2450 return count;
2451}
2452
2453static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2454{
2455 return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2456}
2457
2458static ssize_t
2459sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2460 size_t count, loff_t *off)
2461{
2462 int err;
2463 unsigned long k = ULONG_MAX;
2464
2465 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2466 return -EACCES;
2467
2468 err = kstrtoul_from_user(buffer, count, 0, &k);
2469 if (err)
2470 return err;
2471 if (k <= 1048576) { /* limit "big buff" to 1 MB */
2472 sg_big_buff = k;
2473 return count;
2474 }
2475 return -ERANGE;
2476}
2477
2478static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2479{
2480 seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2481 sg_version_date);
2482 return 0;
2483}
2484
2485static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2486{
2487 return single_open(file, sg_proc_seq_show_version, NULL);
2488}
2489
2490static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2491{
2492 seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2493 return 0;
2494}
2495
2496static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2497{
2498 return single_open(file, sg_proc_seq_show_devhdr, NULL);
2499}
2500
2501struct sg_proc_deviter {
2502 loff_t index;
2503 size_t max;
2504};
2505
2506static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2507{
2508 struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2509
2510 s->private = it;
2511 if (! it)
2512 return NULL;
2513
2514 it->index = *pos;
2515 it->max = sg_last_dev();
2516 if (it->index >= it->max)
2517 return NULL;
2518 return it;
2519}
2520
2521static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2522{
2523 struct sg_proc_deviter * it = s->private;
2524
2525 *pos = ++it->index;
2526 return (it->index < it->max) ? it : NULL;
2527}
2528
2529static void dev_seq_stop(struct seq_file *s, void *v)
2530{
2531 kfree(s->private);
2532}
2533
2534static int sg_proc_open_dev(struct inode *inode, struct file *file)
2535{
2536 return seq_open(file, &dev_seq_ops);
2537}
2538
2539static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2540{
2541 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2542 Sg_device *sdp;
2543 struct scsi_device *scsidp;
2544 unsigned long iflags;
2545
2546 read_lock_irqsave(&sg_index_lock, iflags);
2547 sdp = it ? sg_lookup_dev(it->index) : NULL;
2548 if ((NULL == sdp) || (NULL == sdp->device) ||
2549 (atomic_read(&sdp->detaching)))
2550 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2551 else {
2552 scsidp = sdp->device;
2553 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2554 scsidp->host->host_no, scsidp->channel,
2555 scsidp->id, scsidp->lun, (int) scsidp->type,
2556 1,
2557 (int) scsidp->queue_depth,
2558 (int) atomic_read(&scsidp->device_busy),
2559 (int) scsi_device_online(scsidp));
2560 }
2561 read_unlock_irqrestore(&sg_index_lock, iflags);
2562 return 0;
2563}
2564
2565static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2566{
2567 return seq_open(file, &devstrs_seq_ops);
2568}
2569
2570static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2571{
2572 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2573 Sg_device *sdp;
2574 struct scsi_device *scsidp;
2575 unsigned long iflags;
2576
2577 read_lock_irqsave(&sg_index_lock, iflags);
2578 sdp = it ? sg_lookup_dev(it->index) : NULL;
2579 scsidp = sdp ? sdp->device : NULL;
2580 if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2581 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2582 scsidp->vendor, scsidp->model, scsidp->rev);
2583 else
2584 seq_puts(s, "<no active device>\n");
2585 read_unlock_irqrestore(&sg_index_lock, iflags);
2586 return 0;
2587}
2588
2589/* must be called while holding sg_index_lock */
2590static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2591{
2592 int k, new_interface, blen, usg;
2593 Sg_request *srp;
2594 Sg_fd *fp;
2595 const sg_io_hdr_t *hp;
2596 const char * cp;
2597 unsigned int ms;
2598
2599 k = 0;
2600 list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2601 k++;
2602 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2603 seq_printf(s, " FD(%d): timeout=%dms bufflen=%d "
2604 "(res)sgat=%d low_dma=%d\n", k,
2605 jiffies_to_msecs(fp->timeout),
2606 fp->reserve.bufflen,
2607 (int) fp->reserve.k_use_sg,
2608 (int) sdp->device->host->unchecked_isa_dma);
2609 seq_printf(s, " cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2610 (int) fp->cmd_q, (int) fp->force_packid,
2611 (int) fp->keep_orphan);
2612 list_for_each_entry(srp, &fp->rq_list, entry) {
2613 hp = &srp->header;
2614 new_interface = (hp->interface_id == '\0') ? 0 : 1;
2615 if (srp->res_used) {
2616 if (new_interface &&
2617 (SG_FLAG_MMAP_IO & hp->flags))
2618 cp = " mmap>> ";
2619 else
2620 cp = " rb>> ";
2621 } else {
2622 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2623 cp = " dio>> ";
2624 else
2625 cp = " ";
2626 }
2627 seq_puts(s, cp);
2628 blen = srp->data.bufflen;
2629 usg = srp->data.k_use_sg;
2630 seq_puts(s, srp->done ?
2631 ((1 == srp->done) ? "rcv:" : "fin:")
2632 : "act:");
2633 seq_printf(s, " id=%d blen=%d",
2634 srp->header.pack_id, blen);
2635 if (srp->done)
2636 seq_printf(s, " dur=%d", hp->duration);
2637 else {
2638 ms = jiffies_to_msecs(jiffies);
2639 seq_printf(s, " t_o/elap=%d/%d",
2640 (new_interface ? hp->timeout :
2641 jiffies_to_msecs(fp->timeout)),
2642 (ms > hp->duration ? ms - hp->duration : 0));
2643 }
2644 seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2645 (int) srp->data.cmd_opcode);
2646 }
2647 if (list_empty(&fp->rq_list))
2648 seq_puts(s, " No requests active\n");
2649 read_unlock(&fp->rq_list_lock);
2650 }
2651}
2652
2653static int sg_proc_open_debug(struct inode *inode, struct file *file)
2654{
2655 return seq_open(file, &debug_seq_ops);
2656}
2657
2658static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2659{
2660 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2661 Sg_device *sdp;
2662 unsigned long iflags;
2663
2664 if (it && (0 == it->index))
2665 seq_printf(s, "max_active_device=%d def_reserved_size=%d\n",
2666 (int)it->max, sg_big_buff);
2667
2668 read_lock_irqsave(&sg_index_lock, iflags);
2669 sdp = it ? sg_lookup_dev(it->index) : NULL;
2670 if (NULL == sdp)
2671 goto skip;
2672 read_lock(&sdp->sfd_lock);
2673 if (!list_empty(&sdp->sfds)) {
2674 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2675 if (atomic_read(&sdp->detaching))
2676 seq_puts(s, "detaching pending close ");
2677 else if (sdp->device) {
2678 struct scsi_device *scsidp = sdp->device;
2679
2680 seq_printf(s, "%d:%d:%d:%llu em=%d",
2681 scsidp->host->host_no,
2682 scsidp->channel, scsidp->id,
2683 scsidp->lun,
2684 scsidp->host->hostt->emulated);
2685 }
2686 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2687 sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2688 sg_proc_debug_helper(s, sdp);
2689 }
2690 read_unlock(&sdp->sfd_lock);
2691skip:
2692 read_unlock_irqrestore(&sg_index_lock, iflags);
2693 return 0;
2694}
2695
2696#endif /* CONFIG_SCSI_PROC_FS */
2697
2698module_init(init_sg);
2699module_exit(exit_sg);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * History:
4 * Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
5 * to allow user process control of SCSI devices.
6 * Development Sponsored by Killy Corp. NY NY
7 *
8 * Original driver (sg.c):
9 * Copyright (C) 1992 Lawrence Foard
10 * Version 2 and 3 extensions to driver:
11 * Copyright (C) 1998 - 2014 Douglas Gilbert
12 */
13
14static int sg_version_num = 30536; /* 2 digits for each component */
15#define SG_VERSION_STR "3.5.36"
16
17/*
18 * D. P. Gilbert (dgilbert@interlog.com), notes:
19 * - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
20 * the kernel/module needs to be built with CONFIG_SCSI_LOGGING
21 * (otherwise the macros compile to empty statements).
22 *
23 */
24#include <linux/module.h>
25
26#include <linux/fs.h>
27#include <linux/kernel.h>
28#include <linux/sched.h>
29#include <linux/string.h>
30#include <linux/mm.h>
31#include <linux/errno.h>
32#include <linux/mtio.h>
33#include <linux/ioctl.h>
34#include <linux/slab.h>
35#include <linux/fcntl.h>
36#include <linux/init.h>
37#include <linux/poll.h>
38#include <linux/moduleparam.h>
39#include <linux/cdev.h>
40#include <linux/idr.h>
41#include <linux/seq_file.h>
42#include <linux/blkdev.h>
43#include <linux/delay.h>
44#include <linux/blktrace_api.h>
45#include <linux/mutex.h>
46#include <linux/atomic.h>
47#include <linux/ratelimit.h>
48#include <linux/uio.h>
49#include <linux/cred.h> /* for sg_check_file_access() */
50
51#include "scsi.h"
52#include <scsi/scsi_dbg.h>
53#include <scsi/scsi_host.h>
54#include <scsi/scsi_driver.h>
55#include <scsi/scsi_ioctl.h>
56#include <scsi/sg.h>
57
58#include "scsi_logging.h"
59
60#ifdef CONFIG_SCSI_PROC_FS
61#include <linux/proc_fs.h>
62static char *sg_version_date = "20140603";
63
64static int sg_proc_init(void);
65#endif
66
67#define SG_ALLOW_DIO_DEF 0
68
69#define SG_MAX_DEVS 32768
70
71/* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
72 * of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater
73 * than 16 bytes are "variable length" whose length is a multiple of 4
74 */
75#define SG_MAX_CDB_SIZE 252
76
77#define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
78
79int sg_big_buff = SG_DEF_RESERVED_SIZE;
80/* N.B. This variable is readable and writeable via
81 /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
82 of this size (or less if there is not enough memory) will be reserved
83 for use by this file descriptor. [Deprecated usage: this variable is also
84 readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
85 the kernel (i.e. it is not a module).] */
86static int def_reserved_size = -1; /* picks up init parameter */
87static int sg_allow_dio = SG_ALLOW_DIO_DEF;
88
89static int scatter_elem_sz = SG_SCATTER_SZ;
90static int scatter_elem_sz_prev = SG_SCATTER_SZ;
91
92#define SG_SECTOR_SZ 512
93
94static int sg_add_device(struct device *, struct class_interface *);
95static void sg_remove_device(struct device *, struct class_interface *);
96
97static DEFINE_IDR(sg_index_idr);
98static DEFINE_RWLOCK(sg_index_lock); /* Also used to lock
99 file descriptor list for device */
100
101static struct class_interface sg_interface = {
102 .add_dev = sg_add_device,
103 .remove_dev = sg_remove_device,
104};
105
106typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
107 unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
108 unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
109 unsigned bufflen; /* Size of (aggregate) data buffer */
110 struct page **pages;
111 int page_order;
112 char dio_in_use; /* 0->indirect IO (or mmap), 1->dio */
113 unsigned char cmd_opcode; /* first byte of command */
114} Sg_scatter_hold;
115
116struct sg_device; /* forward declarations */
117struct sg_fd;
118
119typedef struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */
120 struct list_head entry; /* list entry */
121 struct sg_fd *parentfp; /* NULL -> not in use */
122 Sg_scatter_hold data; /* hold buffer, perhaps scatter list */
123 sg_io_hdr_t header; /* scsi command+info, see <scsi/sg.h> */
124 unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
125 char res_used; /* 1 -> using reserve buffer, 0 -> not ... */
126 char orphan; /* 1 -> drop on sight, 0 -> normal */
127 char sg_io_owned; /* 1 -> packet belongs to SG_IO */
128 /* done protected by rq_list_lock */
129 char done; /* 0->before bh, 1->before read, 2->read */
130 struct request *rq;
131 struct bio *bio;
132 struct execute_work ew;
133} Sg_request;
134
135typedef struct sg_fd { /* holds the state of a file descriptor */
136 struct list_head sfd_siblings; /* protected by device's sfd_lock */
137 struct sg_device *parentdp; /* owning device */
138 wait_queue_head_t read_wait; /* queue read until command done */
139 rwlock_t rq_list_lock; /* protect access to list in req_arr */
140 struct mutex f_mutex; /* protect against changes in this fd */
141 int timeout; /* defaults to SG_DEFAULT_TIMEOUT */
142 int timeout_user; /* defaults to SG_DEFAULT_TIMEOUT_USER */
143 Sg_scatter_hold reserve; /* buffer held for this file descriptor */
144 struct list_head rq_list; /* head of request list */
145 struct fasync_struct *async_qp; /* used by asynchronous notification */
146 Sg_request req_arr[SG_MAX_QUEUE]; /* used as singly-linked list */
147 char force_packid; /* 1 -> pack_id input to read(), 0 -> ignored */
148 char cmd_q; /* 1 -> allow command queuing, 0 -> don't */
149 unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */
150 char keep_orphan; /* 0 -> drop orphan (def), 1 -> keep for read() */
151 char mmap_called; /* 0 -> mmap() never called on this fd */
152 char res_in_use; /* 1 -> 'reserve' array in use */
153 struct kref f_ref;
154 struct execute_work ew;
155} Sg_fd;
156
157typedef struct sg_device { /* holds the state of each scsi generic device */
158 struct scsi_device *device;
159 wait_queue_head_t open_wait; /* queue open() when O_EXCL present */
160 struct mutex open_rel_lock; /* held when in open() or release() */
161 int sg_tablesize; /* adapter's max scatter-gather table size */
162 u32 index; /* device index number */
163 struct list_head sfds;
164 rwlock_t sfd_lock; /* protect access to sfd list */
165 atomic_t detaching; /* 0->device usable, 1->device detaching */
166 bool exclude; /* 1->open(O_EXCL) succeeded and is active */
167 int open_cnt; /* count of opens (perhaps < num(sfds) ) */
168 char sgdebug; /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
169 struct gendisk *disk;
170 struct cdev * cdev; /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
171 struct kref d_ref;
172} Sg_device;
173
174/* tasklet or soft irq callback */
175static void sg_rq_end_io(struct request *rq, blk_status_t status);
176static int sg_start_req(Sg_request *srp, unsigned char *cmd);
177static int sg_finish_rem_req(Sg_request * srp);
178static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
179static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
180 Sg_request * srp);
181static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
182 const char __user *buf, size_t count, int blocking,
183 int read_only, int sg_io_owned, Sg_request **o_srp);
184static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
185 unsigned char *cmnd, int timeout, int blocking);
186static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
187static void sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp);
188static void sg_build_reserve(Sg_fd * sfp, int req_size);
189static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
190static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
191static Sg_fd *sg_add_sfp(Sg_device * sdp);
192static void sg_remove_sfp(struct kref *);
193static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
194static Sg_request *sg_add_request(Sg_fd * sfp);
195static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
196static Sg_device *sg_get_dev(int dev);
197static void sg_device_destroy(struct kref *kref);
198
199#define SZ_SG_HEADER sizeof(struct sg_header)
200#define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
201#define SZ_SG_IOVEC sizeof(sg_iovec_t)
202#define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
203
204#define sg_printk(prefix, sdp, fmt, a...) \
205 sdev_prefix_printk(prefix, (sdp)->device, \
206 (sdp)->disk->disk_name, fmt, ##a)
207
208/*
209 * The SCSI interfaces that use read() and write() as an asynchronous variant of
210 * ioctl(..., SG_IO, ...) are fundamentally unsafe, since there are lots of ways
211 * to trigger read() and write() calls from various contexts with elevated
212 * privileges. This can lead to kernel memory corruption (e.g. if these
213 * interfaces are called through splice()) and privilege escalation inside
214 * userspace (e.g. if a process with access to such a device passes a file
215 * descriptor to a SUID binary as stdin/stdout/stderr).
216 *
217 * This function provides protection for the legacy API by restricting the
218 * calling context.
219 */
220static int sg_check_file_access(struct file *filp, const char *caller)
221{
222 if (filp->f_cred != current_real_cred()) {
223 pr_err_once("%s: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
224 caller, task_tgid_vnr(current), current->comm);
225 return -EPERM;
226 }
227 if (uaccess_kernel()) {
228 pr_err_once("%s: process %d (%s) called from kernel context, this is not allowed.\n",
229 caller, task_tgid_vnr(current), current->comm);
230 return -EACCES;
231 }
232 return 0;
233}
234
235static int sg_allow_access(struct file *filp, unsigned char *cmd)
236{
237 struct sg_fd *sfp = filp->private_data;
238
239 if (sfp->parentdp->device->type == TYPE_SCANNER)
240 return 0;
241
242 return blk_verify_command(cmd, filp->f_mode);
243}
244
245static int
246open_wait(Sg_device *sdp, int flags)
247{
248 int retval = 0;
249
250 if (flags & O_EXCL) {
251 while (sdp->open_cnt > 0) {
252 mutex_unlock(&sdp->open_rel_lock);
253 retval = wait_event_interruptible(sdp->open_wait,
254 (atomic_read(&sdp->detaching) ||
255 !sdp->open_cnt));
256 mutex_lock(&sdp->open_rel_lock);
257
258 if (retval) /* -ERESTARTSYS */
259 return retval;
260 if (atomic_read(&sdp->detaching))
261 return -ENODEV;
262 }
263 } else {
264 while (sdp->exclude) {
265 mutex_unlock(&sdp->open_rel_lock);
266 retval = wait_event_interruptible(sdp->open_wait,
267 (atomic_read(&sdp->detaching) ||
268 !sdp->exclude));
269 mutex_lock(&sdp->open_rel_lock);
270
271 if (retval) /* -ERESTARTSYS */
272 return retval;
273 if (atomic_read(&sdp->detaching))
274 return -ENODEV;
275 }
276 }
277
278 return retval;
279}
280
281/* Returns 0 on success, else a negated errno value */
282static int
283sg_open(struct inode *inode, struct file *filp)
284{
285 int dev = iminor(inode);
286 int flags = filp->f_flags;
287 struct request_queue *q;
288 Sg_device *sdp;
289 Sg_fd *sfp;
290 int retval;
291
292 nonseekable_open(inode, filp);
293 if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
294 return -EPERM; /* Can't lock it with read only access */
295 sdp = sg_get_dev(dev);
296 if (IS_ERR(sdp))
297 return PTR_ERR(sdp);
298
299 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
300 "sg_open: flags=0x%x\n", flags));
301
302 /* This driver's module count bumped by fops_get in <linux/fs.h> */
303 /* Prevent the device driver from vanishing while we sleep */
304 retval = scsi_device_get(sdp->device);
305 if (retval)
306 goto sg_put;
307
308 retval = scsi_autopm_get_device(sdp->device);
309 if (retval)
310 goto sdp_put;
311
312 /* scsi_block_when_processing_errors() may block so bypass
313 * check if O_NONBLOCK. Permits SCSI commands to be issued
314 * during error recovery. Tread carefully. */
315 if (!((flags & O_NONBLOCK) ||
316 scsi_block_when_processing_errors(sdp->device))) {
317 retval = -ENXIO;
318 /* we are in error recovery for this device */
319 goto error_out;
320 }
321
322 mutex_lock(&sdp->open_rel_lock);
323 if (flags & O_NONBLOCK) {
324 if (flags & O_EXCL) {
325 if (sdp->open_cnt > 0) {
326 retval = -EBUSY;
327 goto error_mutex_locked;
328 }
329 } else {
330 if (sdp->exclude) {
331 retval = -EBUSY;
332 goto error_mutex_locked;
333 }
334 }
335 } else {
336 retval = open_wait(sdp, flags);
337 if (retval) /* -ERESTARTSYS or -ENODEV */
338 goto error_mutex_locked;
339 }
340
341 /* N.B. at this point we are holding the open_rel_lock */
342 if (flags & O_EXCL)
343 sdp->exclude = true;
344
345 if (sdp->open_cnt < 1) { /* no existing opens */
346 sdp->sgdebug = 0;
347 q = sdp->device->request_queue;
348 sdp->sg_tablesize = queue_max_segments(q);
349 }
350 sfp = sg_add_sfp(sdp);
351 if (IS_ERR(sfp)) {
352 retval = PTR_ERR(sfp);
353 goto out_undo;
354 }
355
356 filp->private_data = sfp;
357 sdp->open_cnt++;
358 mutex_unlock(&sdp->open_rel_lock);
359
360 retval = 0;
361sg_put:
362 kref_put(&sdp->d_ref, sg_device_destroy);
363 return retval;
364
365out_undo:
366 if (flags & O_EXCL) {
367 sdp->exclude = false; /* undo if error */
368 wake_up_interruptible(&sdp->open_wait);
369 }
370error_mutex_locked:
371 mutex_unlock(&sdp->open_rel_lock);
372error_out:
373 scsi_autopm_put_device(sdp->device);
374sdp_put:
375 scsi_device_put(sdp->device);
376 goto sg_put;
377}
378
379/* Release resources associated with a successful sg_open()
380 * Returns 0 on success, else a negated errno value */
381static int
382sg_release(struct inode *inode, struct file *filp)
383{
384 Sg_device *sdp;
385 Sg_fd *sfp;
386
387 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
388 return -ENXIO;
389 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
390
391 mutex_lock(&sdp->open_rel_lock);
392 scsi_autopm_put_device(sdp->device);
393 kref_put(&sfp->f_ref, sg_remove_sfp);
394 sdp->open_cnt--;
395
396 /* possibly many open()s waiting on exlude clearing, start many;
397 * only open(O_EXCL)s wait on 0==open_cnt so only start one */
398 if (sdp->exclude) {
399 sdp->exclude = false;
400 wake_up_interruptible_all(&sdp->open_wait);
401 } else if (0 == sdp->open_cnt) {
402 wake_up_interruptible(&sdp->open_wait);
403 }
404 mutex_unlock(&sdp->open_rel_lock);
405 return 0;
406}
407
408static int get_sg_io_pack_id(int *pack_id, void __user *buf, size_t count)
409{
410 struct sg_header __user *old_hdr = buf;
411 int reply_len;
412
413 if (count >= SZ_SG_HEADER) {
414 /* negative reply_len means v3 format, otherwise v1/v2 */
415 if (get_user(reply_len, &old_hdr->reply_len))
416 return -EFAULT;
417
418 if (reply_len >= 0)
419 return get_user(*pack_id, &old_hdr->pack_id);
420
421 if (in_compat_syscall() &&
422 count >= sizeof(struct compat_sg_io_hdr)) {
423 struct compat_sg_io_hdr __user *hp = buf;
424
425 return get_user(*pack_id, &hp->pack_id);
426 }
427
428 if (count >= sizeof(struct sg_io_hdr)) {
429 struct sg_io_hdr __user *hp = buf;
430
431 return get_user(*pack_id, &hp->pack_id);
432 }
433 }
434
435 /* no valid header was passed, so ignore the pack_id */
436 *pack_id = -1;
437 return 0;
438}
439
440static ssize_t
441sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
442{
443 Sg_device *sdp;
444 Sg_fd *sfp;
445 Sg_request *srp;
446 int req_pack_id = -1;
447 sg_io_hdr_t *hp;
448 struct sg_header *old_hdr;
449 int retval;
450
451 /*
452 * This could cause a response to be stranded. Close the associated
453 * file descriptor to free up any resources being held.
454 */
455 retval = sg_check_file_access(filp, __func__);
456 if (retval)
457 return retval;
458
459 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
460 return -ENXIO;
461 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
462 "sg_read: count=%d\n", (int) count));
463
464 if (sfp->force_packid)
465 retval = get_sg_io_pack_id(&req_pack_id, buf, count);
466 if (retval)
467 return retval;
468
469 srp = sg_get_rq_mark(sfp, req_pack_id);
470 if (!srp) { /* now wait on packet to arrive */
471 if (atomic_read(&sdp->detaching))
472 return -ENODEV;
473 if (filp->f_flags & O_NONBLOCK)
474 return -EAGAIN;
475 retval = wait_event_interruptible(sfp->read_wait,
476 (atomic_read(&sdp->detaching) ||
477 (srp = sg_get_rq_mark(sfp, req_pack_id))));
478 if (atomic_read(&sdp->detaching))
479 return -ENODEV;
480 if (retval)
481 /* -ERESTARTSYS as signal hit process */
482 return retval;
483 }
484 if (srp->header.interface_id != '\0')
485 return sg_new_read(sfp, buf, count, srp);
486
487 hp = &srp->header;
488 old_hdr = kzalloc(SZ_SG_HEADER, GFP_KERNEL);
489 if (!old_hdr)
490 return -ENOMEM;
491
492 old_hdr->reply_len = (int) hp->timeout;
493 old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
494 old_hdr->pack_id = hp->pack_id;
495 old_hdr->twelve_byte =
496 ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
497 old_hdr->target_status = hp->masked_status;
498 old_hdr->host_status = hp->host_status;
499 old_hdr->driver_status = hp->driver_status;
500 if ((CHECK_CONDITION & hp->masked_status) ||
501 (DRIVER_SENSE & hp->driver_status))
502 memcpy(old_hdr->sense_buffer, srp->sense_b,
503 sizeof (old_hdr->sense_buffer));
504 switch (hp->host_status) {
505 /* This setup of 'result' is for backward compatibility and is best
506 ignored by the user who should use target, host + driver status */
507 case DID_OK:
508 case DID_PASSTHROUGH:
509 case DID_SOFT_ERROR:
510 old_hdr->result = 0;
511 break;
512 case DID_NO_CONNECT:
513 case DID_BUS_BUSY:
514 case DID_TIME_OUT:
515 old_hdr->result = EBUSY;
516 break;
517 case DID_BAD_TARGET:
518 case DID_ABORT:
519 case DID_PARITY:
520 case DID_RESET:
521 case DID_BAD_INTR:
522 old_hdr->result = EIO;
523 break;
524 case DID_ERROR:
525 old_hdr->result = (srp->sense_b[0] == 0 &&
526 hp->masked_status == GOOD) ? 0 : EIO;
527 break;
528 default:
529 old_hdr->result = EIO;
530 break;
531 }
532
533 /* Now copy the result back to the user buffer. */
534 if (count >= SZ_SG_HEADER) {
535 if (copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
536 retval = -EFAULT;
537 goto free_old_hdr;
538 }
539 buf += SZ_SG_HEADER;
540 if (count > old_hdr->reply_len)
541 count = old_hdr->reply_len;
542 if (count > SZ_SG_HEADER) {
543 if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
544 retval = -EFAULT;
545 goto free_old_hdr;
546 }
547 }
548 } else
549 count = (old_hdr->result == 0) ? 0 : -EIO;
550 sg_finish_rem_req(srp);
551 sg_remove_request(sfp, srp);
552 retval = count;
553free_old_hdr:
554 kfree(old_hdr);
555 return retval;
556}
557
558static ssize_t
559sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
560{
561 sg_io_hdr_t *hp = &srp->header;
562 int err = 0, err2;
563 int len;
564
565 if (in_compat_syscall()) {
566 if (count < sizeof(struct compat_sg_io_hdr)) {
567 err = -EINVAL;
568 goto err_out;
569 }
570 } else if (count < SZ_SG_IO_HDR) {
571 err = -EINVAL;
572 goto err_out;
573 }
574 hp->sb_len_wr = 0;
575 if ((hp->mx_sb_len > 0) && hp->sbp) {
576 if ((CHECK_CONDITION & hp->masked_status) ||
577 (DRIVER_SENSE & hp->driver_status)) {
578 int sb_len = SCSI_SENSE_BUFFERSIZE;
579 sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
580 len = 8 + (int) srp->sense_b[7]; /* Additional sense length field */
581 len = (len > sb_len) ? sb_len : len;
582 if (copy_to_user(hp->sbp, srp->sense_b, len)) {
583 err = -EFAULT;
584 goto err_out;
585 }
586 hp->sb_len_wr = len;
587 }
588 }
589 if (hp->masked_status || hp->host_status || hp->driver_status)
590 hp->info |= SG_INFO_CHECK;
591 err = put_sg_io_hdr(hp, buf);
592err_out:
593 err2 = sg_finish_rem_req(srp);
594 sg_remove_request(sfp, srp);
595 return err ? : err2 ? : count;
596}
597
598static ssize_t
599sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
600{
601 int mxsize, cmd_size, k;
602 int input_size, blocking;
603 unsigned char opcode;
604 Sg_device *sdp;
605 Sg_fd *sfp;
606 Sg_request *srp;
607 struct sg_header old_hdr;
608 sg_io_hdr_t *hp;
609 unsigned char cmnd[SG_MAX_CDB_SIZE];
610 int retval;
611
612 retval = sg_check_file_access(filp, __func__);
613 if (retval)
614 return retval;
615
616 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
617 return -ENXIO;
618 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
619 "sg_write: count=%d\n", (int) count));
620 if (atomic_read(&sdp->detaching))
621 return -ENODEV;
622 if (!((filp->f_flags & O_NONBLOCK) ||
623 scsi_block_when_processing_errors(sdp->device)))
624 return -ENXIO;
625
626 if (count < SZ_SG_HEADER)
627 return -EIO;
628 if (copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
629 return -EFAULT;
630 blocking = !(filp->f_flags & O_NONBLOCK);
631 if (old_hdr.reply_len < 0)
632 return sg_new_write(sfp, filp, buf, count,
633 blocking, 0, 0, NULL);
634 if (count < (SZ_SG_HEADER + 6))
635 return -EIO; /* The minimum scsi command length is 6 bytes. */
636
637 buf += SZ_SG_HEADER;
638 if (get_user(opcode, buf))
639 return -EFAULT;
640
641 if (!(srp = sg_add_request(sfp))) {
642 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
643 "sg_write: queue full\n"));
644 return -EDOM;
645 }
646 mutex_lock(&sfp->f_mutex);
647 if (sfp->next_cmd_len > 0) {
648 cmd_size = sfp->next_cmd_len;
649 sfp->next_cmd_len = 0; /* reset so only this write() effected */
650 } else {
651 cmd_size = COMMAND_SIZE(opcode); /* based on SCSI command group */
652 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
653 cmd_size = 12;
654 }
655 mutex_unlock(&sfp->f_mutex);
656 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
657 "sg_write: scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
658/* Determine buffer size. */
659 input_size = count - cmd_size;
660 mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
661 mxsize -= SZ_SG_HEADER;
662 input_size -= SZ_SG_HEADER;
663 if (input_size < 0) {
664 sg_remove_request(sfp, srp);
665 return -EIO; /* User did not pass enough bytes for this command. */
666 }
667 hp = &srp->header;
668 hp->interface_id = '\0'; /* indicator of old interface tunnelled */
669 hp->cmd_len = (unsigned char) cmd_size;
670 hp->iovec_count = 0;
671 hp->mx_sb_len = 0;
672 if (input_size > 0)
673 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
674 SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
675 else
676 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
677 hp->dxfer_len = mxsize;
678 if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
679 (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
680 hp->dxferp = (char __user *)buf + cmd_size;
681 else
682 hp->dxferp = NULL;
683 hp->sbp = NULL;
684 hp->timeout = old_hdr.reply_len; /* structure abuse ... */
685 hp->flags = input_size; /* structure abuse ... */
686 hp->pack_id = old_hdr.pack_id;
687 hp->usr_ptr = NULL;
688 if (copy_from_user(cmnd, buf, cmd_size)) {
689 sg_remove_request(sfp, srp);
690 return -EFAULT;
691 }
692 /*
693 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
694 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
695 * is a non-zero input_size, so emit a warning.
696 */
697 if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
698 printk_ratelimited(KERN_WARNING
699 "sg_write: data in/out %d/%d bytes "
700 "for SCSI command 0x%x-- guessing "
701 "data in;\n program %s not setting "
702 "count and/or reply_len properly\n",
703 old_hdr.reply_len - (int)SZ_SG_HEADER,
704 input_size, (unsigned int) cmnd[0],
705 current->comm);
706 }
707 k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
708 return (k < 0) ? k : count;
709}
710
711static ssize_t
712sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
713 size_t count, int blocking, int read_only, int sg_io_owned,
714 Sg_request **o_srp)
715{
716 int k;
717 Sg_request *srp;
718 sg_io_hdr_t *hp;
719 unsigned char cmnd[SG_MAX_CDB_SIZE];
720 int timeout;
721 unsigned long ul_timeout;
722
723 if (count < SZ_SG_IO_HDR)
724 return -EINVAL;
725
726 sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
727 if (!(srp = sg_add_request(sfp))) {
728 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
729 "sg_new_write: queue full\n"));
730 return -EDOM;
731 }
732 srp->sg_io_owned = sg_io_owned;
733 hp = &srp->header;
734 if (get_sg_io_hdr(hp, buf)) {
735 sg_remove_request(sfp, srp);
736 return -EFAULT;
737 }
738 if (hp->interface_id != 'S') {
739 sg_remove_request(sfp, srp);
740 return -ENOSYS;
741 }
742 if (hp->flags & SG_FLAG_MMAP_IO) {
743 if (hp->dxfer_len > sfp->reserve.bufflen) {
744 sg_remove_request(sfp, srp);
745 return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
746 }
747 if (hp->flags & SG_FLAG_DIRECT_IO) {
748 sg_remove_request(sfp, srp);
749 return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
750 }
751 if (sfp->res_in_use) {
752 sg_remove_request(sfp, srp);
753 return -EBUSY; /* reserve buffer already being used */
754 }
755 }
756 ul_timeout = msecs_to_jiffies(srp->header.timeout);
757 timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
758 if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
759 sg_remove_request(sfp, srp);
760 return -EMSGSIZE;
761 }
762 if (copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
763 sg_remove_request(sfp, srp);
764 return -EFAULT;
765 }
766 if (read_only && sg_allow_access(file, cmnd)) {
767 sg_remove_request(sfp, srp);
768 return -EPERM;
769 }
770 k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
771 if (k < 0)
772 return k;
773 if (o_srp)
774 *o_srp = srp;
775 return count;
776}
777
778static int
779sg_common_write(Sg_fd * sfp, Sg_request * srp,
780 unsigned char *cmnd, int timeout, int blocking)
781{
782 int k, at_head;
783 Sg_device *sdp = sfp->parentdp;
784 sg_io_hdr_t *hp = &srp->header;
785
786 srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
787 hp->status = 0;
788 hp->masked_status = 0;
789 hp->msg_status = 0;
790 hp->info = 0;
791 hp->host_status = 0;
792 hp->driver_status = 0;
793 hp->resid = 0;
794 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
795 "sg_common_write: scsi opcode=0x%02x, cmd_size=%d\n",
796 (int) cmnd[0], (int) hp->cmd_len));
797
798 if (hp->dxfer_len >= SZ_256M) {
799 sg_remove_request(sfp, srp);
800 return -EINVAL;
801 }
802
803 k = sg_start_req(srp, cmnd);
804 if (k) {
805 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
806 "sg_common_write: start_req err=%d\n", k));
807 sg_finish_rem_req(srp);
808 sg_remove_request(sfp, srp);
809 return k; /* probably out of space --> ENOMEM */
810 }
811 if (atomic_read(&sdp->detaching)) {
812 if (srp->bio) {
813 scsi_req_free_cmd(scsi_req(srp->rq));
814 blk_put_request(srp->rq);
815 srp->rq = NULL;
816 }
817
818 sg_finish_rem_req(srp);
819 sg_remove_request(sfp, srp);
820 return -ENODEV;
821 }
822
823 hp->duration = jiffies_to_msecs(jiffies);
824 if (hp->interface_id != '\0' && /* v3 (or later) interface */
825 (SG_FLAG_Q_AT_TAIL & hp->flags))
826 at_head = 0;
827 else
828 at_head = 1;
829
830 srp->rq->timeout = timeout;
831 kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
832 blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
833 srp->rq, at_head, sg_rq_end_io);
834 return 0;
835}
836
837static int srp_done(Sg_fd *sfp, Sg_request *srp)
838{
839 unsigned long flags;
840 int ret;
841
842 read_lock_irqsave(&sfp->rq_list_lock, flags);
843 ret = srp->done;
844 read_unlock_irqrestore(&sfp->rq_list_lock, flags);
845 return ret;
846}
847
848static int max_sectors_bytes(struct request_queue *q)
849{
850 unsigned int max_sectors = queue_max_sectors(q);
851
852 max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
853
854 return max_sectors << 9;
855}
856
857static void
858sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
859{
860 Sg_request *srp;
861 int val;
862 unsigned int ms;
863
864 val = 0;
865 list_for_each_entry(srp, &sfp->rq_list, entry) {
866 if (val >= SG_MAX_QUEUE)
867 break;
868 rinfo[val].req_state = srp->done + 1;
869 rinfo[val].problem =
870 srp->header.masked_status &
871 srp->header.host_status &
872 srp->header.driver_status;
873 if (srp->done)
874 rinfo[val].duration =
875 srp->header.duration;
876 else {
877 ms = jiffies_to_msecs(jiffies);
878 rinfo[val].duration =
879 (ms > srp->header.duration) ?
880 (ms - srp->header.duration) : 0;
881 }
882 rinfo[val].orphan = srp->orphan;
883 rinfo[val].sg_io_owned = srp->sg_io_owned;
884 rinfo[val].pack_id = srp->header.pack_id;
885 rinfo[val].usr_ptr = srp->header.usr_ptr;
886 val++;
887 }
888}
889
890#ifdef CONFIG_COMPAT
891struct compat_sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
892 char req_state;
893 char orphan;
894 char sg_io_owned;
895 char problem;
896 int pack_id;
897 compat_uptr_t usr_ptr;
898 unsigned int duration;
899 int unused;
900};
901
902static int put_compat_request_table(struct compat_sg_req_info __user *o,
903 struct sg_req_info *rinfo)
904{
905 int i;
906 for (i = 0; i < SG_MAX_QUEUE; i++) {
907 if (copy_to_user(o + i, rinfo + i, offsetof(sg_req_info_t, usr_ptr)) ||
908 put_user((uintptr_t)rinfo[i].usr_ptr, &o[i].usr_ptr) ||
909 put_user(rinfo[i].duration, &o[i].duration) ||
910 put_user(rinfo[i].unused, &o[i].unused))
911 return -EFAULT;
912 }
913 return 0;
914}
915#endif
916
917static long
918sg_ioctl_common(struct file *filp, Sg_device *sdp, Sg_fd *sfp,
919 unsigned int cmd_in, void __user *p)
920{
921 int __user *ip = p;
922 int result, val, read_only;
923 Sg_request *srp;
924 unsigned long iflags;
925
926 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
927 "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
928 read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
929
930 switch (cmd_in) {
931 case SG_IO:
932 if (atomic_read(&sdp->detaching))
933 return -ENODEV;
934 if (!scsi_block_when_processing_errors(sdp->device))
935 return -ENXIO;
936 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
937 1, read_only, 1, &srp);
938 if (result < 0)
939 return result;
940 result = wait_event_interruptible(sfp->read_wait,
941 (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
942 if (atomic_read(&sdp->detaching))
943 return -ENODEV;
944 write_lock_irq(&sfp->rq_list_lock);
945 if (srp->done) {
946 srp->done = 2;
947 write_unlock_irq(&sfp->rq_list_lock);
948 result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
949 return (result < 0) ? result : 0;
950 }
951 srp->orphan = 1;
952 write_unlock_irq(&sfp->rq_list_lock);
953 return result; /* -ERESTARTSYS because signal hit process */
954 case SG_SET_TIMEOUT:
955 result = get_user(val, ip);
956 if (result)
957 return result;
958 if (val < 0)
959 return -EIO;
960 if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
961 val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
962 INT_MAX);
963 sfp->timeout_user = val;
964 sfp->timeout = mult_frac(val, HZ, USER_HZ);
965
966 return 0;
967 case SG_GET_TIMEOUT: /* N.B. User receives timeout as return value */
968 /* strange ..., for backward compatibility */
969 return sfp->timeout_user;
970 case SG_SET_FORCE_LOW_DMA:
971 /*
972 * N.B. This ioctl never worked properly, but failed to
973 * return an error value. So returning '0' to keep compability
974 * with legacy applications.
975 */
976 return 0;
977 case SG_GET_LOW_DMA:
978 return put_user((int) sdp->device->host->unchecked_isa_dma, ip);
979 case SG_GET_SCSI_ID:
980 {
981 sg_scsi_id_t v;
982
983 if (atomic_read(&sdp->detaching))
984 return -ENODEV;
985 memset(&v, 0, sizeof(v));
986 v.host_no = sdp->device->host->host_no;
987 v.channel = sdp->device->channel;
988 v.scsi_id = sdp->device->id;
989 v.lun = sdp->device->lun;
990 v.scsi_type = sdp->device->type;
991 v.h_cmd_per_lun = sdp->device->host->cmd_per_lun;
992 v.d_queue_depth = sdp->device->queue_depth;
993 if (copy_to_user(p, &v, sizeof(sg_scsi_id_t)))
994 return -EFAULT;
995 return 0;
996 }
997 case SG_SET_FORCE_PACK_ID:
998 result = get_user(val, ip);
999 if (result)
1000 return result;
1001 sfp->force_packid = val ? 1 : 0;
1002 return 0;
1003 case SG_GET_PACK_ID:
1004 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1005 list_for_each_entry(srp, &sfp->rq_list, entry) {
1006 if ((1 == srp->done) && (!srp->sg_io_owned)) {
1007 read_unlock_irqrestore(&sfp->rq_list_lock,
1008 iflags);
1009 return put_user(srp->header.pack_id, ip);
1010 }
1011 }
1012 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1013 return put_user(-1, ip);
1014 case SG_GET_NUM_WAITING:
1015 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1016 val = 0;
1017 list_for_each_entry(srp, &sfp->rq_list, entry) {
1018 if ((1 == srp->done) && (!srp->sg_io_owned))
1019 ++val;
1020 }
1021 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1022 return put_user(val, ip);
1023 case SG_GET_SG_TABLESIZE:
1024 return put_user(sdp->sg_tablesize, ip);
1025 case SG_SET_RESERVED_SIZE:
1026 result = get_user(val, ip);
1027 if (result)
1028 return result;
1029 if (val < 0)
1030 return -EINVAL;
1031 val = min_t(int, val,
1032 max_sectors_bytes(sdp->device->request_queue));
1033 mutex_lock(&sfp->f_mutex);
1034 if (val != sfp->reserve.bufflen) {
1035 if (sfp->mmap_called ||
1036 sfp->res_in_use) {
1037 mutex_unlock(&sfp->f_mutex);
1038 return -EBUSY;
1039 }
1040
1041 sg_remove_scat(sfp, &sfp->reserve);
1042 sg_build_reserve(sfp, val);
1043 }
1044 mutex_unlock(&sfp->f_mutex);
1045 return 0;
1046 case SG_GET_RESERVED_SIZE:
1047 val = min_t(int, sfp->reserve.bufflen,
1048 max_sectors_bytes(sdp->device->request_queue));
1049 return put_user(val, ip);
1050 case SG_SET_COMMAND_Q:
1051 result = get_user(val, ip);
1052 if (result)
1053 return result;
1054 sfp->cmd_q = val ? 1 : 0;
1055 return 0;
1056 case SG_GET_COMMAND_Q:
1057 return put_user((int) sfp->cmd_q, ip);
1058 case SG_SET_KEEP_ORPHAN:
1059 result = get_user(val, ip);
1060 if (result)
1061 return result;
1062 sfp->keep_orphan = val;
1063 return 0;
1064 case SG_GET_KEEP_ORPHAN:
1065 return put_user((int) sfp->keep_orphan, ip);
1066 case SG_NEXT_CMD_LEN:
1067 result = get_user(val, ip);
1068 if (result)
1069 return result;
1070 if (val > SG_MAX_CDB_SIZE)
1071 return -ENOMEM;
1072 sfp->next_cmd_len = (val > 0) ? val : 0;
1073 return 0;
1074 case SG_GET_VERSION_NUM:
1075 return put_user(sg_version_num, ip);
1076 case SG_GET_ACCESS_COUNT:
1077 /* faked - we don't have a real access count anymore */
1078 val = (sdp->device ? 1 : 0);
1079 return put_user(val, ip);
1080 case SG_GET_REQUEST_TABLE:
1081 {
1082 sg_req_info_t *rinfo;
1083
1084 rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
1085 GFP_KERNEL);
1086 if (!rinfo)
1087 return -ENOMEM;
1088 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1089 sg_fill_request_table(sfp, rinfo);
1090 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1091 #ifdef CONFIG_COMPAT
1092 if (in_compat_syscall())
1093 result = put_compat_request_table(p, rinfo);
1094 else
1095 #endif
1096 result = copy_to_user(p, rinfo,
1097 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1098 result = result ? -EFAULT : 0;
1099 kfree(rinfo);
1100 return result;
1101 }
1102 case SG_EMULATED_HOST:
1103 if (atomic_read(&sdp->detaching))
1104 return -ENODEV;
1105 return put_user(sdp->device->host->hostt->emulated, ip);
1106 case SCSI_IOCTL_SEND_COMMAND:
1107 if (atomic_read(&sdp->detaching))
1108 return -ENODEV;
1109 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1110 case SG_SET_DEBUG:
1111 result = get_user(val, ip);
1112 if (result)
1113 return result;
1114 sdp->sgdebug = (char) val;
1115 return 0;
1116 case BLKSECTGET:
1117 return put_user(max_sectors_bytes(sdp->device->request_queue),
1118 ip);
1119 case BLKTRACESETUP:
1120 return blk_trace_setup(sdp->device->request_queue,
1121 sdp->disk->disk_name,
1122 MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1123 NULL, p);
1124 case BLKTRACESTART:
1125 return blk_trace_startstop(sdp->device->request_queue, 1);
1126 case BLKTRACESTOP:
1127 return blk_trace_startstop(sdp->device->request_queue, 0);
1128 case BLKTRACETEARDOWN:
1129 return blk_trace_remove(sdp->device->request_queue);
1130 case SCSI_IOCTL_GET_IDLUN:
1131 case SCSI_IOCTL_GET_BUS_NUMBER:
1132 case SCSI_IOCTL_PROBE_HOST:
1133 case SG_GET_TRANSFORM:
1134 case SG_SCSI_RESET:
1135 if (atomic_read(&sdp->detaching))
1136 return -ENODEV;
1137 break;
1138 default:
1139 if (read_only)
1140 return -EPERM; /* don't know so take safe approach */
1141 break;
1142 }
1143
1144 result = scsi_ioctl_block_when_processing_errors(sdp->device,
1145 cmd_in, filp->f_flags & O_NDELAY);
1146 if (result)
1147 return result;
1148
1149 return -ENOIOCTLCMD;
1150}
1151
1152static long
1153sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1154{
1155 void __user *p = (void __user *)arg;
1156 Sg_device *sdp;
1157 Sg_fd *sfp;
1158 int ret;
1159
1160 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1161 return -ENXIO;
1162
1163 ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
1164 if (ret != -ENOIOCTLCMD)
1165 return ret;
1166
1167 return scsi_ioctl(sdp->device, cmd_in, p);
1168}
1169
1170#ifdef CONFIG_COMPAT
1171static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1172{
1173 void __user *p = compat_ptr(arg);
1174 Sg_device *sdp;
1175 Sg_fd *sfp;
1176 int ret;
1177
1178 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1179 return -ENXIO;
1180
1181 ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
1182 if (ret != -ENOIOCTLCMD)
1183 return ret;
1184
1185 return scsi_compat_ioctl(sdp->device, cmd_in, p);
1186}
1187#endif
1188
1189static __poll_t
1190sg_poll(struct file *filp, poll_table * wait)
1191{
1192 __poll_t res = 0;
1193 Sg_device *sdp;
1194 Sg_fd *sfp;
1195 Sg_request *srp;
1196 int count = 0;
1197 unsigned long iflags;
1198
1199 sfp = filp->private_data;
1200 if (!sfp)
1201 return EPOLLERR;
1202 sdp = sfp->parentdp;
1203 if (!sdp)
1204 return EPOLLERR;
1205 poll_wait(filp, &sfp->read_wait, wait);
1206 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1207 list_for_each_entry(srp, &sfp->rq_list, entry) {
1208 /* if any read waiting, flag it */
1209 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1210 res = EPOLLIN | EPOLLRDNORM;
1211 ++count;
1212 }
1213 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1214
1215 if (atomic_read(&sdp->detaching))
1216 res |= EPOLLHUP;
1217 else if (!sfp->cmd_q) {
1218 if (0 == count)
1219 res |= EPOLLOUT | EPOLLWRNORM;
1220 } else if (count < SG_MAX_QUEUE)
1221 res |= EPOLLOUT | EPOLLWRNORM;
1222 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1223 "sg_poll: res=0x%x\n", (__force u32) res));
1224 return res;
1225}
1226
1227static int
1228sg_fasync(int fd, struct file *filp, int mode)
1229{
1230 Sg_device *sdp;
1231 Sg_fd *sfp;
1232
1233 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1234 return -ENXIO;
1235 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1236 "sg_fasync: mode=%d\n", mode));
1237
1238 return fasync_helper(fd, filp, mode, &sfp->async_qp);
1239}
1240
1241static vm_fault_t
1242sg_vma_fault(struct vm_fault *vmf)
1243{
1244 struct vm_area_struct *vma = vmf->vma;
1245 Sg_fd *sfp;
1246 unsigned long offset, len, sa;
1247 Sg_scatter_hold *rsv_schp;
1248 int k, length;
1249
1250 if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1251 return VM_FAULT_SIGBUS;
1252 rsv_schp = &sfp->reserve;
1253 offset = vmf->pgoff << PAGE_SHIFT;
1254 if (offset >= rsv_schp->bufflen)
1255 return VM_FAULT_SIGBUS;
1256 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1257 "sg_vma_fault: offset=%lu, scatg=%d\n",
1258 offset, rsv_schp->k_use_sg));
1259 sa = vma->vm_start;
1260 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1261 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1262 len = vma->vm_end - sa;
1263 len = (len < length) ? len : length;
1264 if (offset < len) {
1265 struct page *page = nth_page(rsv_schp->pages[k],
1266 offset >> PAGE_SHIFT);
1267 get_page(page); /* increment page count */
1268 vmf->page = page;
1269 return 0; /* success */
1270 }
1271 sa += len;
1272 offset -= len;
1273 }
1274
1275 return VM_FAULT_SIGBUS;
1276}
1277
1278static const struct vm_operations_struct sg_mmap_vm_ops = {
1279 .fault = sg_vma_fault,
1280};
1281
1282static int
1283sg_mmap(struct file *filp, struct vm_area_struct *vma)
1284{
1285 Sg_fd *sfp;
1286 unsigned long req_sz, len, sa;
1287 Sg_scatter_hold *rsv_schp;
1288 int k, length;
1289 int ret = 0;
1290
1291 if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1292 return -ENXIO;
1293 req_sz = vma->vm_end - vma->vm_start;
1294 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1295 "sg_mmap starting, vm_start=%p, len=%d\n",
1296 (void *) vma->vm_start, (int) req_sz));
1297 if (vma->vm_pgoff)
1298 return -EINVAL; /* want no offset */
1299 rsv_schp = &sfp->reserve;
1300 mutex_lock(&sfp->f_mutex);
1301 if (req_sz > rsv_schp->bufflen) {
1302 ret = -ENOMEM; /* cannot map more than reserved buffer */
1303 goto out;
1304 }
1305
1306 sa = vma->vm_start;
1307 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1308 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1309 len = vma->vm_end - sa;
1310 len = (len < length) ? len : length;
1311 sa += len;
1312 }
1313
1314 sfp->mmap_called = 1;
1315 vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
1316 vma->vm_private_data = sfp;
1317 vma->vm_ops = &sg_mmap_vm_ops;
1318out:
1319 mutex_unlock(&sfp->f_mutex);
1320 return ret;
1321}
1322
1323static void
1324sg_rq_end_io_usercontext(struct work_struct *work)
1325{
1326 struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1327 struct sg_fd *sfp = srp->parentfp;
1328
1329 sg_finish_rem_req(srp);
1330 sg_remove_request(sfp, srp);
1331 kref_put(&sfp->f_ref, sg_remove_sfp);
1332}
1333
1334/*
1335 * This function is a "bottom half" handler that is called by the mid
1336 * level when a command is completed (or has failed).
1337 */
1338static void
1339sg_rq_end_io(struct request *rq, blk_status_t status)
1340{
1341 struct sg_request *srp = rq->end_io_data;
1342 struct scsi_request *req = scsi_req(rq);
1343 Sg_device *sdp;
1344 Sg_fd *sfp;
1345 unsigned long iflags;
1346 unsigned int ms;
1347 char *sense;
1348 int result, resid, done = 1;
1349
1350 if (WARN_ON(srp->done != 0))
1351 return;
1352
1353 sfp = srp->parentfp;
1354 if (WARN_ON(sfp == NULL))
1355 return;
1356
1357 sdp = sfp->parentdp;
1358 if (unlikely(atomic_read(&sdp->detaching)))
1359 pr_info("%s: device detaching\n", __func__);
1360
1361 sense = req->sense;
1362 result = req->result;
1363 resid = req->resid_len;
1364
1365 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1366 "sg_cmd_done: pack_id=%d, res=0x%x\n",
1367 srp->header.pack_id, result));
1368 srp->header.resid = resid;
1369 ms = jiffies_to_msecs(jiffies);
1370 srp->header.duration = (ms > srp->header.duration) ?
1371 (ms - srp->header.duration) : 0;
1372 if (0 != result) {
1373 struct scsi_sense_hdr sshdr;
1374
1375 srp->header.status = 0xff & result;
1376 srp->header.masked_status = status_byte(result);
1377 srp->header.msg_status = msg_byte(result);
1378 srp->header.host_status = host_byte(result);
1379 srp->header.driver_status = driver_byte(result);
1380 if ((sdp->sgdebug > 0) &&
1381 ((CHECK_CONDITION == srp->header.masked_status) ||
1382 (COMMAND_TERMINATED == srp->header.masked_status)))
1383 __scsi_print_sense(sdp->device, __func__, sense,
1384 SCSI_SENSE_BUFFERSIZE);
1385
1386 /* Following if statement is a patch supplied by Eric Youngdale */
1387 if (driver_byte(result) != 0
1388 && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1389 && !scsi_sense_is_deferred(&sshdr)
1390 && sshdr.sense_key == UNIT_ATTENTION
1391 && sdp->device->removable) {
1392 /* Detected possible disc change. Set the bit - this */
1393 /* may be used if there are filesystems using this device */
1394 sdp->device->changed = 1;
1395 }
1396 }
1397
1398 if (req->sense_len)
1399 memcpy(srp->sense_b, req->sense, SCSI_SENSE_BUFFERSIZE);
1400
1401 /* Rely on write phase to clean out srp status values, so no "else" */
1402
1403 /*
1404 * Free the request as soon as it is complete so that its resources
1405 * can be reused without waiting for userspace to read() the
1406 * result. But keep the associated bio (if any) around until
1407 * blk_rq_unmap_user() can be called from user context.
1408 */
1409 srp->rq = NULL;
1410 scsi_req_free_cmd(scsi_req(rq));
1411 blk_put_request(rq);
1412
1413 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1414 if (unlikely(srp->orphan)) {
1415 if (sfp->keep_orphan)
1416 srp->sg_io_owned = 0;
1417 else
1418 done = 0;
1419 }
1420 srp->done = done;
1421 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1422
1423 if (likely(done)) {
1424 /* Now wake up any sg_read() that is waiting for this
1425 * packet.
1426 */
1427 wake_up_interruptible(&sfp->read_wait);
1428 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1429 kref_put(&sfp->f_ref, sg_remove_sfp);
1430 } else {
1431 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1432 schedule_work(&srp->ew.work);
1433 }
1434}
1435
1436static const struct file_operations sg_fops = {
1437 .owner = THIS_MODULE,
1438 .read = sg_read,
1439 .write = sg_write,
1440 .poll = sg_poll,
1441 .unlocked_ioctl = sg_ioctl,
1442#ifdef CONFIG_COMPAT
1443 .compat_ioctl = sg_compat_ioctl,
1444#endif
1445 .open = sg_open,
1446 .mmap = sg_mmap,
1447 .release = sg_release,
1448 .fasync = sg_fasync,
1449 .llseek = no_llseek,
1450};
1451
1452static struct class *sg_sysfs_class;
1453
1454static int sg_sysfs_valid = 0;
1455
1456static Sg_device *
1457sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1458{
1459 struct request_queue *q = scsidp->request_queue;
1460 Sg_device *sdp;
1461 unsigned long iflags;
1462 int error;
1463 u32 k;
1464
1465 sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1466 if (!sdp) {
1467 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1468 "failure\n", __func__);
1469 return ERR_PTR(-ENOMEM);
1470 }
1471
1472 idr_preload(GFP_KERNEL);
1473 write_lock_irqsave(&sg_index_lock, iflags);
1474
1475 error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1476 if (error < 0) {
1477 if (error == -ENOSPC) {
1478 sdev_printk(KERN_WARNING, scsidp,
1479 "Unable to attach sg device type=%d, minor number exceeds %d\n",
1480 scsidp->type, SG_MAX_DEVS - 1);
1481 error = -ENODEV;
1482 } else {
1483 sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1484 "allocation Sg_device failure: %d\n",
1485 __func__, error);
1486 }
1487 goto out_unlock;
1488 }
1489 k = error;
1490
1491 SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1492 "sg_alloc: dev=%d \n", k));
1493 sprintf(disk->disk_name, "sg%d", k);
1494 disk->first_minor = k;
1495 sdp->disk = disk;
1496 sdp->device = scsidp;
1497 mutex_init(&sdp->open_rel_lock);
1498 INIT_LIST_HEAD(&sdp->sfds);
1499 init_waitqueue_head(&sdp->open_wait);
1500 atomic_set(&sdp->detaching, 0);
1501 rwlock_init(&sdp->sfd_lock);
1502 sdp->sg_tablesize = queue_max_segments(q);
1503 sdp->index = k;
1504 kref_init(&sdp->d_ref);
1505 error = 0;
1506
1507out_unlock:
1508 write_unlock_irqrestore(&sg_index_lock, iflags);
1509 idr_preload_end();
1510
1511 if (error) {
1512 kfree(sdp);
1513 return ERR_PTR(error);
1514 }
1515 return sdp;
1516}
1517
1518static int
1519sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
1520{
1521 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1522 struct gendisk *disk;
1523 Sg_device *sdp = NULL;
1524 struct cdev * cdev = NULL;
1525 int error;
1526 unsigned long iflags;
1527
1528 disk = alloc_disk(1);
1529 if (!disk) {
1530 pr_warn("%s: alloc_disk failed\n", __func__);
1531 return -ENOMEM;
1532 }
1533 disk->major = SCSI_GENERIC_MAJOR;
1534
1535 error = -ENOMEM;
1536 cdev = cdev_alloc();
1537 if (!cdev) {
1538 pr_warn("%s: cdev_alloc failed\n", __func__);
1539 goto out;
1540 }
1541 cdev->owner = THIS_MODULE;
1542 cdev->ops = &sg_fops;
1543
1544 sdp = sg_alloc(disk, scsidp);
1545 if (IS_ERR(sdp)) {
1546 pr_warn("%s: sg_alloc failed\n", __func__);
1547 error = PTR_ERR(sdp);
1548 goto out;
1549 }
1550
1551 error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1552 if (error)
1553 goto cdev_add_err;
1554
1555 sdp->cdev = cdev;
1556 if (sg_sysfs_valid) {
1557 struct device *sg_class_member;
1558
1559 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1560 MKDEV(SCSI_GENERIC_MAJOR,
1561 sdp->index),
1562 sdp, "%s", disk->disk_name);
1563 if (IS_ERR(sg_class_member)) {
1564 pr_err("%s: device_create failed\n", __func__);
1565 error = PTR_ERR(sg_class_member);
1566 goto cdev_add_err;
1567 }
1568 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1569 &sg_class_member->kobj, "generic");
1570 if (error)
1571 pr_err("%s: unable to make symlink 'generic' back "
1572 "to sg%d\n", __func__, sdp->index);
1573 } else
1574 pr_warn("%s: sg_sys Invalid\n", __func__);
1575
1576 sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1577 "type %d\n", sdp->index, scsidp->type);
1578
1579 dev_set_drvdata(cl_dev, sdp);
1580
1581 return 0;
1582
1583cdev_add_err:
1584 write_lock_irqsave(&sg_index_lock, iflags);
1585 idr_remove(&sg_index_idr, sdp->index);
1586 write_unlock_irqrestore(&sg_index_lock, iflags);
1587 kfree(sdp);
1588
1589out:
1590 put_disk(disk);
1591 if (cdev)
1592 cdev_del(cdev);
1593 return error;
1594}
1595
1596static void
1597sg_device_destroy(struct kref *kref)
1598{
1599 struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1600 unsigned long flags;
1601
1602 /* CAUTION! Note that the device can still be found via idr_find()
1603 * even though the refcount is 0. Therefore, do idr_remove() BEFORE
1604 * any other cleanup.
1605 */
1606
1607 write_lock_irqsave(&sg_index_lock, flags);
1608 idr_remove(&sg_index_idr, sdp->index);
1609 write_unlock_irqrestore(&sg_index_lock, flags);
1610
1611 SCSI_LOG_TIMEOUT(3,
1612 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1613
1614 put_disk(sdp->disk);
1615 kfree(sdp);
1616}
1617
1618static void
1619sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
1620{
1621 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1622 Sg_device *sdp = dev_get_drvdata(cl_dev);
1623 unsigned long iflags;
1624 Sg_fd *sfp;
1625 int val;
1626
1627 if (!sdp)
1628 return;
1629 /* want sdp->detaching non-zero as soon as possible */
1630 val = atomic_inc_return(&sdp->detaching);
1631 if (val > 1)
1632 return; /* only want to do following once per device */
1633
1634 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1635 "%s\n", __func__));
1636
1637 read_lock_irqsave(&sdp->sfd_lock, iflags);
1638 list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1639 wake_up_interruptible_all(&sfp->read_wait);
1640 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1641 }
1642 wake_up_interruptible_all(&sdp->open_wait);
1643 read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1644
1645 sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1646 device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1647 cdev_del(sdp->cdev);
1648 sdp->cdev = NULL;
1649
1650 kref_put(&sdp->d_ref, sg_device_destroy);
1651}
1652
1653module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1654module_param_named(def_reserved_size, def_reserved_size, int,
1655 S_IRUGO | S_IWUSR);
1656module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1657
1658MODULE_AUTHOR("Douglas Gilbert");
1659MODULE_DESCRIPTION("SCSI generic (sg) driver");
1660MODULE_LICENSE("GPL");
1661MODULE_VERSION(SG_VERSION_STR);
1662MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1663
1664MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1665 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1666MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1667MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1668
1669static int __init
1670init_sg(void)
1671{
1672 int rc;
1673
1674 if (scatter_elem_sz < PAGE_SIZE) {
1675 scatter_elem_sz = PAGE_SIZE;
1676 scatter_elem_sz_prev = scatter_elem_sz;
1677 }
1678 if (def_reserved_size >= 0)
1679 sg_big_buff = def_reserved_size;
1680 else
1681 def_reserved_size = sg_big_buff;
1682
1683 rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1684 SG_MAX_DEVS, "sg");
1685 if (rc)
1686 return rc;
1687 sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1688 if ( IS_ERR(sg_sysfs_class) ) {
1689 rc = PTR_ERR(sg_sysfs_class);
1690 goto err_out;
1691 }
1692 sg_sysfs_valid = 1;
1693 rc = scsi_register_interface(&sg_interface);
1694 if (0 == rc) {
1695#ifdef CONFIG_SCSI_PROC_FS
1696 sg_proc_init();
1697#endif /* CONFIG_SCSI_PROC_FS */
1698 return 0;
1699 }
1700 class_destroy(sg_sysfs_class);
1701err_out:
1702 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1703 return rc;
1704}
1705
1706static void __exit
1707exit_sg(void)
1708{
1709#ifdef CONFIG_SCSI_PROC_FS
1710 remove_proc_subtree("scsi/sg", NULL);
1711#endif /* CONFIG_SCSI_PROC_FS */
1712 scsi_unregister_interface(&sg_interface);
1713 class_destroy(sg_sysfs_class);
1714 sg_sysfs_valid = 0;
1715 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1716 SG_MAX_DEVS);
1717 idr_destroy(&sg_index_idr);
1718}
1719
1720static int
1721sg_start_req(Sg_request *srp, unsigned char *cmd)
1722{
1723 int res;
1724 struct request *rq;
1725 struct scsi_request *req;
1726 Sg_fd *sfp = srp->parentfp;
1727 sg_io_hdr_t *hp = &srp->header;
1728 int dxfer_len = (int) hp->dxfer_len;
1729 int dxfer_dir = hp->dxfer_direction;
1730 unsigned int iov_count = hp->iovec_count;
1731 Sg_scatter_hold *req_schp = &srp->data;
1732 Sg_scatter_hold *rsv_schp = &sfp->reserve;
1733 struct request_queue *q = sfp->parentdp->device->request_queue;
1734 struct rq_map_data *md, map_data;
1735 int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1736 unsigned char *long_cmdp = NULL;
1737
1738 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1739 "sg_start_req: dxfer_len=%d\n",
1740 dxfer_len));
1741
1742 if (hp->cmd_len > BLK_MAX_CDB) {
1743 long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
1744 if (!long_cmdp)
1745 return -ENOMEM;
1746 }
1747
1748 /*
1749 * NOTE
1750 *
1751 * With scsi-mq enabled, there are a fixed number of preallocated
1752 * requests equal in number to shost->can_queue. If all of the
1753 * preallocated requests are already in use, then blk_get_request()
1754 * will sleep until an active command completes, freeing up a request.
1755 * Although waiting in an asynchronous interface is less than ideal, we
1756 * do not want to use BLK_MQ_REQ_NOWAIT here because userspace might
1757 * not expect an EWOULDBLOCK from this condition.
1758 */
1759 rq = blk_get_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
1760 REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
1761 if (IS_ERR(rq)) {
1762 kfree(long_cmdp);
1763 return PTR_ERR(rq);
1764 }
1765 req = scsi_req(rq);
1766
1767 if (hp->cmd_len > BLK_MAX_CDB)
1768 req->cmd = long_cmdp;
1769 memcpy(req->cmd, cmd, hp->cmd_len);
1770 req->cmd_len = hp->cmd_len;
1771
1772 srp->rq = rq;
1773 rq->end_io_data = srp;
1774 req->retries = SG_DEFAULT_RETRIES;
1775
1776 if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1777 return 0;
1778
1779 if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1780 dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1781 !sfp->parentdp->device->host->unchecked_isa_dma &&
1782 blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1783 md = NULL;
1784 else
1785 md = &map_data;
1786
1787 if (md) {
1788 mutex_lock(&sfp->f_mutex);
1789 if (dxfer_len <= rsv_schp->bufflen &&
1790 !sfp->res_in_use) {
1791 sfp->res_in_use = 1;
1792 sg_link_reserve(sfp, srp, dxfer_len);
1793 } else if (hp->flags & SG_FLAG_MMAP_IO) {
1794 res = -EBUSY; /* sfp->res_in_use == 1 */
1795 if (dxfer_len > rsv_schp->bufflen)
1796 res = -ENOMEM;
1797 mutex_unlock(&sfp->f_mutex);
1798 return res;
1799 } else {
1800 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1801 if (res) {
1802 mutex_unlock(&sfp->f_mutex);
1803 return res;
1804 }
1805 }
1806 mutex_unlock(&sfp->f_mutex);
1807
1808 md->pages = req_schp->pages;
1809 md->page_order = req_schp->page_order;
1810 md->nr_entries = req_schp->k_use_sg;
1811 md->offset = 0;
1812 md->null_mapped = hp->dxferp ? 0 : 1;
1813 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1814 md->from_user = 1;
1815 else
1816 md->from_user = 0;
1817 }
1818
1819 if (iov_count) {
1820 struct iovec *iov = NULL;
1821 struct iov_iter i;
1822
1823#ifdef CONFIG_COMPAT
1824 if (in_compat_syscall())
1825 res = compat_import_iovec(rw, hp->dxferp, iov_count,
1826 0, &iov, &i);
1827 else
1828#endif
1829 res = import_iovec(rw, hp->dxferp, iov_count,
1830 0, &iov, &i);
1831 if (res < 0)
1832 return res;
1833
1834 iov_iter_truncate(&i, hp->dxfer_len);
1835 if (!iov_iter_count(&i)) {
1836 kfree(iov);
1837 return -EINVAL;
1838 }
1839
1840 res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
1841 kfree(iov);
1842 } else
1843 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1844 hp->dxfer_len, GFP_ATOMIC);
1845
1846 if (!res) {
1847 srp->bio = rq->bio;
1848
1849 if (!md) {
1850 req_schp->dio_in_use = 1;
1851 hp->info |= SG_INFO_DIRECT_IO;
1852 }
1853 }
1854 return res;
1855}
1856
1857static int
1858sg_finish_rem_req(Sg_request *srp)
1859{
1860 int ret = 0;
1861
1862 Sg_fd *sfp = srp->parentfp;
1863 Sg_scatter_hold *req_schp = &srp->data;
1864
1865 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1866 "sg_finish_rem_req: res_used=%d\n",
1867 (int) srp->res_used));
1868 if (srp->bio)
1869 ret = blk_rq_unmap_user(srp->bio);
1870
1871 if (srp->rq) {
1872 scsi_req_free_cmd(scsi_req(srp->rq));
1873 blk_put_request(srp->rq);
1874 }
1875
1876 if (srp->res_used)
1877 sg_unlink_reserve(sfp, srp);
1878 else
1879 sg_remove_scat(sfp, req_schp);
1880
1881 return ret;
1882}
1883
1884static int
1885sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1886{
1887 int sg_bufflen = tablesize * sizeof(struct page *);
1888 gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1889
1890 schp->pages = kzalloc(sg_bufflen, gfp_flags);
1891 if (!schp->pages)
1892 return -ENOMEM;
1893 schp->sglist_len = sg_bufflen;
1894 return tablesize; /* number of scat_gath elements allocated */
1895}
1896
1897static int
1898sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1899{
1900 int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1901 int sg_tablesize = sfp->parentdp->sg_tablesize;
1902 int blk_size = buff_size, order;
1903 gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
1904 struct sg_device *sdp = sfp->parentdp;
1905
1906 if (blk_size < 0)
1907 return -EFAULT;
1908 if (0 == blk_size)
1909 ++blk_size; /* don't know why */
1910 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1911 blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1912 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1913 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1914 buff_size, blk_size));
1915
1916 /* N.B. ret_sz carried into this block ... */
1917 mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1918 if (mx_sc_elems < 0)
1919 return mx_sc_elems; /* most likely -ENOMEM */
1920
1921 num = scatter_elem_sz;
1922 if (unlikely(num != scatter_elem_sz_prev)) {
1923 if (num < PAGE_SIZE) {
1924 scatter_elem_sz = PAGE_SIZE;
1925 scatter_elem_sz_prev = PAGE_SIZE;
1926 } else
1927 scatter_elem_sz_prev = num;
1928 }
1929
1930 if (sdp->device->host->unchecked_isa_dma)
1931 gfp_mask |= GFP_DMA;
1932
1933 order = get_order(num);
1934retry:
1935 ret_sz = 1 << (PAGE_SHIFT + order);
1936
1937 for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1938 k++, rem_sz -= ret_sz) {
1939
1940 num = (rem_sz > scatter_elem_sz_prev) ?
1941 scatter_elem_sz_prev : rem_sz;
1942
1943 schp->pages[k] = alloc_pages(gfp_mask, order);
1944 if (!schp->pages[k])
1945 goto out;
1946
1947 if (num == scatter_elem_sz_prev) {
1948 if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1949 scatter_elem_sz = ret_sz;
1950 scatter_elem_sz_prev = ret_sz;
1951 }
1952 }
1953
1954 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1955 "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1956 k, num, ret_sz));
1957 } /* end of for loop */
1958
1959 schp->page_order = order;
1960 schp->k_use_sg = k;
1961 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1962 "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1963 k, rem_sz));
1964
1965 schp->bufflen = blk_size;
1966 if (rem_sz > 0) /* must have failed */
1967 return -ENOMEM;
1968 return 0;
1969out:
1970 for (i = 0; i < k; i++)
1971 __free_pages(schp->pages[i], order);
1972
1973 if (--order >= 0)
1974 goto retry;
1975
1976 return -ENOMEM;
1977}
1978
1979static void
1980sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1981{
1982 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1983 "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1984 if (schp->pages && schp->sglist_len > 0) {
1985 if (!schp->dio_in_use) {
1986 int k;
1987
1988 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1989 SCSI_LOG_TIMEOUT(5,
1990 sg_printk(KERN_INFO, sfp->parentdp,
1991 "sg_remove_scat: k=%d, pg=0x%p\n",
1992 k, schp->pages[k]));
1993 __free_pages(schp->pages[k], schp->page_order);
1994 }
1995
1996 kfree(schp->pages);
1997 }
1998 }
1999 memset(schp, 0, sizeof (*schp));
2000}
2001
2002static int
2003sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
2004{
2005 Sg_scatter_hold *schp = &srp->data;
2006 int k, num;
2007
2008 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2009 "sg_read_oxfer: num_read_xfer=%d\n",
2010 num_read_xfer));
2011 if ((!outp) || (num_read_xfer <= 0))
2012 return 0;
2013
2014 num = 1 << (PAGE_SHIFT + schp->page_order);
2015 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
2016 if (num > num_read_xfer) {
2017 if (copy_to_user(outp, page_address(schp->pages[k]),
2018 num_read_xfer))
2019 return -EFAULT;
2020 break;
2021 } else {
2022 if (copy_to_user(outp, page_address(schp->pages[k]),
2023 num))
2024 return -EFAULT;
2025 num_read_xfer -= num;
2026 if (num_read_xfer <= 0)
2027 break;
2028 outp += num;
2029 }
2030 }
2031
2032 return 0;
2033}
2034
2035static void
2036sg_build_reserve(Sg_fd * sfp, int req_size)
2037{
2038 Sg_scatter_hold *schp = &sfp->reserve;
2039
2040 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2041 "sg_build_reserve: req_size=%d\n", req_size));
2042 do {
2043 if (req_size < PAGE_SIZE)
2044 req_size = PAGE_SIZE;
2045 if (0 == sg_build_indirect(schp, sfp, req_size))
2046 return;
2047 else
2048 sg_remove_scat(sfp, schp);
2049 req_size >>= 1; /* divide by 2 */
2050 } while (req_size > (PAGE_SIZE / 2));
2051}
2052
2053static void
2054sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2055{
2056 Sg_scatter_hold *req_schp = &srp->data;
2057 Sg_scatter_hold *rsv_schp = &sfp->reserve;
2058 int k, num, rem;
2059
2060 srp->res_used = 1;
2061 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2062 "sg_link_reserve: size=%d\n", size));
2063 rem = size;
2064
2065 num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
2066 for (k = 0; k < rsv_schp->k_use_sg; k++) {
2067 if (rem <= num) {
2068 req_schp->k_use_sg = k + 1;
2069 req_schp->sglist_len = rsv_schp->sglist_len;
2070 req_schp->pages = rsv_schp->pages;
2071
2072 req_schp->bufflen = size;
2073 req_schp->page_order = rsv_schp->page_order;
2074 break;
2075 } else
2076 rem -= num;
2077 }
2078
2079 if (k >= rsv_schp->k_use_sg)
2080 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2081 "sg_link_reserve: BAD size\n"));
2082}
2083
2084static void
2085sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2086{
2087 Sg_scatter_hold *req_schp = &srp->data;
2088
2089 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2090 "sg_unlink_reserve: req->k_use_sg=%d\n",
2091 (int) req_schp->k_use_sg));
2092 req_schp->k_use_sg = 0;
2093 req_schp->bufflen = 0;
2094 req_schp->pages = NULL;
2095 req_schp->page_order = 0;
2096 req_schp->sglist_len = 0;
2097 srp->res_used = 0;
2098 /* Called without mutex lock to avoid deadlock */
2099 sfp->res_in_use = 0;
2100}
2101
2102static Sg_request *
2103sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2104{
2105 Sg_request *resp;
2106 unsigned long iflags;
2107
2108 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2109 list_for_each_entry(resp, &sfp->rq_list, entry) {
2110 /* look for requests that are ready + not SG_IO owned */
2111 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2112 ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2113 resp->done = 2; /* guard against other readers */
2114 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2115 return resp;
2116 }
2117 }
2118 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2119 return NULL;
2120}
2121
2122/* always adds to end of list */
2123static Sg_request *
2124sg_add_request(Sg_fd * sfp)
2125{
2126 int k;
2127 unsigned long iflags;
2128 Sg_request *rp = sfp->req_arr;
2129
2130 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2131 if (!list_empty(&sfp->rq_list)) {
2132 if (!sfp->cmd_q)
2133 goto out_unlock;
2134
2135 for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2136 if (!rp->parentfp)
2137 break;
2138 }
2139 if (k >= SG_MAX_QUEUE)
2140 goto out_unlock;
2141 }
2142 memset(rp, 0, sizeof (Sg_request));
2143 rp->parentfp = sfp;
2144 rp->header.duration = jiffies_to_msecs(jiffies);
2145 list_add_tail(&rp->entry, &sfp->rq_list);
2146 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2147 return rp;
2148out_unlock:
2149 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2150 return NULL;
2151}
2152
2153/* Return of 1 for found; 0 for not found */
2154static int
2155sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2156{
2157 unsigned long iflags;
2158 int res = 0;
2159
2160 if (!sfp || !srp || list_empty(&sfp->rq_list))
2161 return res;
2162 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2163 if (!list_empty(&srp->entry)) {
2164 list_del(&srp->entry);
2165 srp->parentfp = NULL;
2166 res = 1;
2167 }
2168 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2169 return res;
2170}
2171
2172static Sg_fd *
2173sg_add_sfp(Sg_device * sdp)
2174{
2175 Sg_fd *sfp;
2176 unsigned long iflags;
2177 int bufflen;
2178
2179 sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2180 if (!sfp)
2181 return ERR_PTR(-ENOMEM);
2182
2183 init_waitqueue_head(&sfp->read_wait);
2184 rwlock_init(&sfp->rq_list_lock);
2185 INIT_LIST_HEAD(&sfp->rq_list);
2186 kref_init(&sfp->f_ref);
2187 mutex_init(&sfp->f_mutex);
2188 sfp->timeout = SG_DEFAULT_TIMEOUT;
2189 sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2190 sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2191 sfp->cmd_q = SG_DEF_COMMAND_Q;
2192 sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2193 sfp->parentdp = sdp;
2194 write_lock_irqsave(&sdp->sfd_lock, iflags);
2195 if (atomic_read(&sdp->detaching)) {
2196 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2197 kfree(sfp);
2198 return ERR_PTR(-ENODEV);
2199 }
2200 list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2201 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2202 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2203 "sg_add_sfp: sfp=0x%p\n", sfp));
2204 if (unlikely(sg_big_buff != def_reserved_size))
2205 sg_big_buff = def_reserved_size;
2206
2207 bufflen = min_t(int, sg_big_buff,
2208 max_sectors_bytes(sdp->device->request_queue));
2209 sg_build_reserve(sfp, bufflen);
2210 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2211 "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2212 sfp->reserve.bufflen,
2213 sfp->reserve.k_use_sg));
2214
2215 kref_get(&sdp->d_ref);
2216 __module_get(THIS_MODULE);
2217 return sfp;
2218}
2219
2220static void
2221sg_remove_sfp_usercontext(struct work_struct *work)
2222{
2223 struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2224 struct sg_device *sdp = sfp->parentdp;
2225 Sg_request *srp;
2226 unsigned long iflags;
2227
2228 /* Cleanup any responses which were never read(). */
2229 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2230 while (!list_empty(&sfp->rq_list)) {
2231 srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2232 sg_finish_rem_req(srp);
2233 list_del(&srp->entry);
2234 srp->parentfp = NULL;
2235 }
2236 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2237
2238 if (sfp->reserve.bufflen > 0) {
2239 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2240 "sg_remove_sfp: bufflen=%d, k_use_sg=%d\n",
2241 (int) sfp->reserve.bufflen,
2242 (int) sfp->reserve.k_use_sg));
2243 sg_remove_scat(sfp, &sfp->reserve);
2244 }
2245
2246 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2247 "sg_remove_sfp: sfp=0x%p\n", sfp));
2248 kfree(sfp);
2249
2250 scsi_device_put(sdp->device);
2251 kref_put(&sdp->d_ref, sg_device_destroy);
2252 module_put(THIS_MODULE);
2253}
2254
2255static void
2256sg_remove_sfp(struct kref *kref)
2257{
2258 struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2259 struct sg_device *sdp = sfp->parentdp;
2260 unsigned long iflags;
2261
2262 write_lock_irqsave(&sdp->sfd_lock, iflags);
2263 list_del(&sfp->sfd_siblings);
2264 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2265
2266 INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2267 schedule_work(&sfp->ew.work);
2268}
2269
2270#ifdef CONFIG_SCSI_PROC_FS
2271static int
2272sg_idr_max_id(int id, void *p, void *data)
2273{
2274 int *k = data;
2275
2276 if (*k < id)
2277 *k = id;
2278
2279 return 0;
2280}
2281
2282static int
2283sg_last_dev(void)
2284{
2285 int k = -1;
2286 unsigned long iflags;
2287
2288 read_lock_irqsave(&sg_index_lock, iflags);
2289 idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2290 read_unlock_irqrestore(&sg_index_lock, iflags);
2291 return k + 1; /* origin 1 */
2292}
2293#endif
2294
2295/* must be called with sg_index_lock held */
2296static Sg_device *sg_lookup_dev(int dev)
2297{
2298 return idr_find(&sg_index_idr, dev);
2299}
2300
2301static Sg_device *
2302sg_get_dev(int dev)
2303{
2304 struct sg_device *sdp;
2305 unsigned long flags;
2306
2307 read_lock_irqsave(&sg_index_lock, flags);
2308 sdp = sg_lookup_dev(dev);
2309 if (!sdp)
2310 sdp = ERR_PTR(-ENXIO);
2311 else if (atomic_read(&sdp->detaching)) {
2312 /* If sdp->detaching, then the refcount may already be 0, in
2313 * which case it would be a bug to do kref_get().
2314 */
2315 sdp = ERR_PTR(-ENODEV);
2316 } else
2317 kref_get(&sdp->d_ref);
2318 read_unlock_irqrestore(&sg_index_lock, flags);
2319
2320 return sdp;
2321}
2322
2323#ifdef CONFIG_SCSI_PROC_FS
2324static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2325
2326static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2327static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2328 size_t count, loff_t *off);
2329static const struct proc_ops adio_proc_ops = {
2330 .proc_open = sg_proc_single_open_adio,
2331 .proc_read = seq_read,
2332 .proc_lseek = seq_lseek,
2333 .proc_write = sg_proc_write_adio,
2334 .proc_release = single_release,
2335};
2336
2337static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2338static ssize_t sg_proc_write_dressz(struct file *filp,
2339 const char __user *buffer, size_t count, loff_t *off);
2340static const struct proc_ops dressz_proc_ops = {
2341 .proc_open = sg_proc_single_open_dressz,
2342 .proc_read = seq_read,
2343 .proc_lseek = seq_lseek,
2344 .proc_write = sg_proc_write_dressz,
2345 .proc_release = single_release,
2346};
2347
2348static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2349static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2350static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2351static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2352static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2353static void dev_seq_stop(struct seq_file *s, void *v);
2354static const struct seq_operations dev_seq_ops = {
2355 .start = dev_seq_start,
2356 .next = dev_seq_next,
2357 .stop = dev_seq_stop,
2358 .show = sg_proc_seq_show_dev,
2359};
2360
2361static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2362static const struct seq_operations devstrs_seq_ops = {
2363 .start = dev_seq_start,
2364 .next = dev_seq_next,
2365 .stop = dev_seq_stop,
2366 .show = sg_proc_seq_show_devstrs,
2367};
2368
2369static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2370static const struct seq_operations debug_seq_ops = {
2371 .start = dev_seq_start,
2372 .next = dev_seq_next,
2373 .stop = dev_seq_stop,
2374 .show = sg_proc_seq_show_debug,
2375};
2376
2377static int
2378sg_proc_init(void)
2379{
2380 struct proc_dir_entry *p;
2381
2382 p = proc_mkdir("scsi/sg", NULL);
2383 if (!p)
2384 return 1;
2385
2386 proc_create("allow_dio", S_IRUGO | S_IWUSR, p, &adio_proc_ops);
2387 proc_create_seq("debug", S_IRUGO, p, &debug_seq_ops);
2388 proc_create("def_reserved_size", S_IRUGO | S_IWUSR, p, &dressz_proc_ops);
2389 proc_create_single("device_hdr", S_IRUGO, p, sg_proc_seq_show_devhdr);
2390 proc_create_seq("devices", S_IRUGO, p, &dev_seq_ops);
2391 proc_create_seq("device_strs", S_IRUGO, p, &devstrs_seq_ops);
2392 proc_create_single("version", S_IRUGO, p, sg_proc_seq_show_version);
2393 return 0;
2394}
2395
2396
2397static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2398{
2399 seq_printf(s, "%d\n", *((int *)s->private));
2400 return 0;
2401}
2402
2403static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2404{
2405 return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2406}
2407
2408static ssize_t
2409sg_proc_write_adio(struct file *filp, const char __user *buffer,
2410 size_t count, loff_t *off)
2411{
2412 int err;
2413 unsigned long num;
2414
2415 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2416 return -EACCES;
2417 err = kstrtoul_from_user(buffer, count, 0, &num);
2418 if (err)
2419 return err;
2420 sg_allow_dio = num ? 1 : 0;
2421 return count;
2422}
2423
2424static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2425{
2426 return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2427}
2428
2429static ssize_t
2430sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2431 size_t count, loff_t *off)
2432{
2433 int err;
2434 unsigned long k = ULONG_MAX;
2435
2436 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2437 return -EACCES;
2438
2439 err = kstrtoul_from_user(buffer, count, 0, &k);
2440 if (err)
2441 return err;
2442 if (k <= 1048576) { /* limit "big buff" to 1 MB */
2443 sg_big_buff = k;
2444 return count;
2445 }
2446 return -ERANGE;
2447}
2448
2449static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2450{
2451 seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2452 sg_version_date);
2453 return 0;
2454}
2455
2456static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2457{
2458 seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2459 return 0;
2460}
2461
2462struct sg_proc_deviter {
2463 loff_t index;
2464 size_t max;
2465};
2466
2467static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2468{
2469 struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2470
2471 s->private = it;
2472 if (! it)
2473 return NULL;
2474
2475 it->index = *pos;
2476 it->max = sg_last_dev();
2477 if (it->index >= it->max)
2478 return NULL;
2479 return it;
2480}
2481
2482static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2483{
2484 struct sg_proc_deviter * it = s->private;
2485
2486 *pos = ++it->index;
2487 return (it->index < it->max) ? it : NULL;
2488}
2489
2490static void dev_seq_stop(struct seq_file *s, void *v)
2491{
2492 kfree(s->private);
2493}
2494
2495static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2496{
2497 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2498 Sg_device *sdp;
2499 struct scsi_device *scsidp;
2500 unsigned long iflags;
2501
2502 read_lock_irqsave(&sg_index_lock, iflags);
2503 sdp = it ? sg_lookup_dev(it->index) : NULL;
2504 if ((NULL == sdp) || (NULL == sdp->device) ||
2505 (atomic_read(&sdp->detaching)))
2506 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2507 else {
2508 scsidp = sdp->device;
2509 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2510 scsidp->host->host_no, scsidp->channel,
2511 scsidp->id, scsidp->lun, (int) scsidp->type,
2512 1,
2513 (int) scsidp->queue_depth,
2514 (int) atomic_read(&scsidp->device_busy),
2515 (int) scsi_device_online(scsidp));
2516 }
2517 read_unlock_irqrestore(&sg_index_lock, iflags);
2518 return 0;
2519}
2520
2521static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2522{
2523 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2524 Sg_device *sdp;
2525 struct scsi_device *scsidp;
2526 unsigned long iflags;
2527
2528 read_lock_irqsave(&sg_index_lock, iflags);
2529 sdp = it ? sg_lookup_dev(it->index) : NULL;
2530 scsidp = sdp ? sdp->device : NULL;
2531 if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2532 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2533 scsidp->vendor, scsidp->model, scsidp->rev);
2534 else
2535 seq_puts(s, "<no active device>\n");
2536 read_unlock_irqrestore(&sg_index_lock, iflags);
2537 return 0;
2538}
2539
2540/* must be called while holding sg_index_lock */
2541static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2542{
2543 int k, new_interface, blen, usg;
2544 Sg_request *srp;
2545 Sg_fd *fp;
2546 const sg_io_hdr_t *hp;
2547 const char * cp;
2548 unsigned int ms;
2549
2550 k = 0;
2551 list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2552 k++;
2553 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2554 seq_printf(s, " FD(%d): timeout=%dms bufflen=%d "
2555 "(res)sgat=%d low_dma=%d\n", k,
2556 jiffies_to_msecs(fp->timeout),
2557 fp->reserve.bufflen,
2558 (int) fp->reserve.k_use_sg,
2559 (int) sdp->device->host->unchecked_isa_dma);
2560 seq_printf(s, " cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2561 (int) fp->cmd_q, (int) fp->force_packid,
2562 (int) fp->keep_orphan);
2563 list_for_each_entry(srp, &fp->rq_list, entry) {
2564 hp = &srp->header;
2565 new_interface = (hp->interface_id == '\0') ? 0 : 1;
2566 if (srp->res_used) {
2567 if (new_interface &&
2568 (SG_FLAG_MMAP_IO & hp->flags))
2569 cp = " mmap>> ";
2570 else
2571 cp = " rb>> ";
2572 } else {
2573 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2574 cp = " dio>> ";
2575 else
2576 cp = " ";
2577 }
2578 seq_puts(s, cp);
2579 blen = srp->data.bufflen;
2580 usg = srp->data.k_use_sg;
2581 seq_puts(s, srp->done ?
2582 ((1 == srp->done) ? "rcv:" : "fin:")
2583 : "act:");
2584 seq_printf(s, " id=%d blen=%d",
2585 srp->header.pack_id, blen);
2586 if (srp->done)
2587 seq_printf(s, " dur=%d", hp->duration);
2588 else {
2589 ms = jiffies_to_msecs(jiffies);
2590 seq_printf(s, " t_o/elap=%d/%d",
2591 (new_interface ? hp->timeout :
2592 jiffies_to_msecs(fp->timeout)),
2593 (ms > hp->duration ? ms - hp->duration : 0));
2594 }
2595 seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2596 (int) srp->data.cmd_opcode);
2597 }
2598 if (list_empty(&fp->rq_list))
2599 seq_puts(s, " No requests active\n");
2600 read_unlock(&fp->rq_list_lock);
2601 }
2602}
2603
2604static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2605{
2606 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2607 Sg_device *sdp;
2608 unsigned long iflags;
2609
2610 if (it && (0 == it->index))
2611 seq_printf(s, "max_active_device=%d def_reserved_size=%d\n",
2612 (int)it->max, sg_big_buff);
2613
2614 read_lock_irqsave(&sg_index_lock, iflags);
2615 sdp = it ? sg_lookup_dev(it->index) : NULL;
2616 if (NULL == sdp)
2617 goto skip;
2618 read_lock(&sdp->sfd_lock);
2619 if (!list_empty(&sdp->sfds)) {
2620 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2621 if (atomic_read(&sdp->detaching))
2622 seq_puts(s, "detaching pending close ");
2623 else if (sdp->device) {
2624 struct scsi_device *scsidp = sdp->device;
2625
2626 seq_printf(s, "%d:%d:%d:%llu em=%d",
2627 scsidp->host->host_no,
2628 scsidp->channel, scsidp->id,
2629 scsidp->lun,
2630 scsidp->host->hostt->emulated);
2631 }
2632 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2633 sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2634 sg_proc_debug_helper(s, sdp);
2635 }
2636 read_unlock(&sdp->sfd_lock);
2637skip:
2638 read_unlock_irqrestore(&sg_index_lock, iflags);
2639 return 0;
2640}
2641
2642#endif /* CONFIG_SCSI_PROC_FS */
2643
2644module_init(init_sg);
2645module_exit(exit_sg);