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Linux 5.1.15
[linux/fpc-iii.git] / drivers / scsi / sg.c
blobd3f15319b9b3c05ddd4801b54537b981c067a0d6
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
19 static 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 #include <linux/cred.h> /* for sg_check_file_access() */
55
56 #include "scsi.h"
57 #include <scsi/scsi_dbg.h>
58 #include <scsi/scsi_host.h>
59 #include <scsi/scsi_driver.h>
60 #include <scsi/scsi_ioctl.h>
61 #include <scsi/sg.h>
62
63 #include "scsi_logging.h"
64
65 #ifdef CONFIG_SCSI_PROC_FS
66 #include <linux/proc_fs.h>
67 static char *sg_version_date = "20140603";
68
69 static int sg_proc_init(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
84 int sg_big_buff = SG_DEF_RESERVED_SIZE;
85 /* N.B. This variable is readable and writeable via
86 /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
87 of this size (or less if there is not enough memory) will be reserved
88 for use by this file descriptor. [Deprecated usage: this variable is also
89 readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
90 the kernel (i.e. it is not a module).] */
91 static int def_reserved_size = -1; /* picks up init parameter */
92 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
93
94 static int scatter_elem_sz = SG_SCATTER_SZ;
95 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
96
97 #define SG_SECTOR_SZ 512
98
99 static int sg_add_device(struct device *, struct class_interface *);
100 static void sg_remove_device(struct device *, struct class_interface *);
101
102 static DEFINE_IDR(sg_index_idr);
103 static DEFINE_RWLOCK(sg_index_lock); /* Also used to lock
104 file descriptor list for device */
105
106 static struct class_interface sg_interface = {
107 .add_dev = sg_add_device,
108 .remove_dev = sg_remove_device,
109 };
110
111 typedef 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
121 struct sg_device; /* forward declarations */
122 struct sg_fd;
123
124 typedef 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
140 typedef 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
162 typedef 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 */
180 static void sg_rq_end_io(struct request *rq, blk_status_t status);
181 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
182 static int sg_finish_rem_req(Sg_request * srp);
183 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
184 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
185 Sg_request * srp);
186 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
187 const char __user *buf, size_t count, int blocking,
188 int read_only, int sg_io_owned, Sg_request **o_srp);
189 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
190 unsigned char *cmnd, int timeout, int blocking);
191 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
192 static void sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp);
193 static void sg_build_reserve(Sg_fd * sfp, int req_size);
194 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
195 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
196 static Sg_fd *sg_add_sfp(Sg_device * sdp);
197 static void sg_remove_sfp(struct kref *);
198 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
199 static Sg_request *sg_add_request(Sg_fd * sfp);
200 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
201 static Sg_device *sg_get_dev(int dev);
202 static 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
213 /*
214 * The SCSI interfaces that use read() and write() as an asynchronous variant of
215 * ioctl(..., SG_IO, ...) are fundamentally unsafe, since there are lots of ways
216 * to trigger read() and write() calls from various contexts with elevated
217 * privileges. This can lead to kernel memory corruption (e.g. if these
218 * interfaces are called through splice()) and privilege escalation inside
219 * userspace (e.g. if a process with access to such a device passes a file
220 * descriptor to a SUID binary as stdin/stdout/stderr).
221 *
222 * This function provides protection for the legacy API by restricting the
223 * calling context.
224 */
225 static int sg_check_file_access(struct file *filp, const char *caller)
226 {
227 if (filp->f_cred != current_real_cred()) {
228 pr_err_once("%s: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
229 caller, task_tgid_vnr(current), current->comm);
230 return -EPERM;
231 }
232 if (uaccess_kernel()) {
233 pr_err_once("%s: process %d (%s) called from kernel context, this is not allowed.\n",
234 caller, task_tgid_vnr(current), current->comm);
235 return -EACCES;
236 }
237 return 0;
238 }
239
240 static int sg_allow_access(struct file *filp, unsigned char *cmd)
241 {
242 struct sg_fd *sfp = filp->private_data;
243
244 if (sfp->parentdp->device->type == TYPE_SCANNER)
245 return 0;
246
247 return blk_verify_command(cmd, filp->f_mode);
248 }
249
250 static int
251 open_wait(Sg_device *sdp, int flags)
252 {
253 int retval = 0;
254
255 if (flags & O_EXCL) {
256 while (sdp->open_cnt > 0) {
257 mutex_unlock(&sdp->open_rel_lock);
258 retval = wait_event_interruptible(sdp->open_wait,
259 (atomic_read(&sdp->detaching) ||
260 !sdp->open_cnt));
261 mutex_lock(&sdp->open_rel_lock);
262
263 if (retval) /* -ERESTARTSYS */
264 return retval;
265 if (atomic_read(&sdp->detaching))
266 return -ENODEV;
267 }
268 } else {
269 while (sdp->exclude) {
270 mutex_unlock(&sdp->open_rel_lock);
271 retval = wait_event_interruptible(sdp->open_wait,
272 (atomic_read(&sdp->detaching) ||
273 !sdp->exclude));
274 mutex_lock(&sdp->open_rel_lock);
275
276 if (retval) /* -ERESTARTSYS */
277 return retval;
278 if (atomic_read(&sdp->detaching))
279 return -ENODEV;
280 }
281 }
282
283 return retval;
284 }
285
286 /* Returns 0 on success, else a negated errno value */
287 static int
288 sg_open(struct inode *inode, struct file *filp)
289 {
290 int dev = iminor(inode);
291 int flags = filp->f_flags;
292 struct request_queue *q;
293 Sg_device *sdp;
294 Sg_fd *sfp;
295 int retval;
296
297 nonseekable_open(inode, filp);
298 if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
299 return -EPERM; /* Can't lock it with read only access */
300 sdp = sg_get_dev(dev);
301 if (IS_ERR(sdp))
302 return PTR_ERR(sdp);
303
304 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
305 "sg_open: flags=0x%x\n", flags));
306
307 /* This driver's module count bumped by fops_get in <linux/fs.h> */
308 /* Prevent the device driver from vanishing while we sleep */
309 retval = scsi_device_get(sdp->device);
310 if (retval)
311 goto sg_put;
312
313 retval = scsi_autopm_get_device(sdp->device);
314 if (retval)
315 goto sdp_put;
316
317 /* scsi_block_when_processing_errors() may block so bypass
318 * check if O_NONBLOCK. Permits SCSI commands to be issued
319 * during error recovery. Tread carefully. */
320 if (!((flags & O_NONBLOCK) ||
321 scsi_block_when_processing_errors(sdp->device))) {
322 retval = -ENXIO;
323 /* we are in error recovery for this device */
324 goto error_out;
325 }
326
327 mutex_lock(&sdp->open_rel_lock);
328 if (flags & O_NONBLOCK) {
329 if (flags & O_EXCL) {
330 if (sdp->open_cnt > 0) {
331 retval = -EBUSY;
332 goto error_mutex_locked;
333 }
334 } else {
335 if (sdp->exclude) {
336 retval = -EBUSY;
337 goto error_mutex_locked;
338 }
339 }
340 } else {
341 retval = open_wait(sdp, flags);
342 if (retval) /* -ERESTARTSYS or -ENODEV */
343 goto error_mutex_locked;
344 }
345
346 /* N.B. at this point we are holding the open_rel_lock */
347 if (flags & O_EXCL)
348 sdp->exclude = true;
349
350 if (sdp->open_cnt < 1) { /* no existing opens */
351 sdp->sgdebug = 0;
352 q = sdp->device->request_queue;
353 sdp->sg_tablesize = queue_max_segments(q);
354 }
355 sfp = sg_add_sfp(sdp);
356 if (IS_ERR(sfp)) {
357 retval = PTR_ERR(sfp);
358 goto out_undo;
359 }
360
361 filp->private_data = sfp;
362 sdp->open_cnt++;
363 mutex_unlock(&sdp->open_rel_lock);
364
365 retval = 0;
366 sg_put:
367 kref_put(&sdp->d_ref, sg_device_destroy);
368 return retval;
369
370 out_undo:
371 if (flags & O_EXCL) {
372 sdp->exclude = false; /* undo if error */
373 wake_up_interruptible(&sdp->open_wait);
374 }
375 error_mutex_locked:
376 mutex_unlock(&sdp->open_rel_lock);
377 error_out:
378 scsi_autopm_put_device(sdp->device);
379 sdp_put:
380 scsi_device_put(sdp->device);
381 goto sg_put;
382 }
383
384 /* Release resources associated with a successful sg_open()
385 * Returns 0 on success, else a negated errno value */
386 static int
387 sg_release(struct inode *inode, struct file *filp)
388 {
389 Sg_device *sdp;
390 Sg_fd *sfp;
391
392 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
393 return -ENXIO;
394 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
395
396 mutex_lock(&sdp->open_rel_lock);
397 scsi_autopm_put_device(sdp->device);
398 kref_put(&sfp->f_ref, sg_remove_sfp);
399 sdp->open_cnt--;
400
401 /* possibly many open()s waiting on exlude clearing, start many;
402 * only open(O_EXCL)s wait on 0==open_cnt so only start one */
403 if (sdp->exclude) {
404 sdp->exclude = false;
405 wake_up_interruptible_all(&sdp->open_wait);
406 } else if (0 == sdp->open_cnt) {
407 wake_up_interruptible(&sdp->open_wait);
408 }
409 mutex_unlock(&sdp->open_rel_lock);
410 return 0;
411 }
412
413 static ssize_t
414 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
415 {
416 Sg_device *sdp;
417 Sg_fd *sfp;
418 Sg_request *srp;
419 int req_pack_id = -1;
420 sg_io_hdr_t *hp;
421 struct sg_header *old_hdr = NULL;
422 int retval = 0;
423
424 /*
425 * This could cause a response to be stranded. Close the associated
426 * file descriptor to free up any resources being held.
427 */
428 retval = sg_check_file_access(filp, __func__);
429 if (retval)
430 return retval;
431
432 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
433 return -ENXIO;
434 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
435 "sg_read: count=%d\n", (int) count));
436
437 if (!access_ok(buf, count))
438 return -EFAULT;
439 if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
440 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
441 if (!old_hdr)
442 return -ENOMEM;
443 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
444 retval = -EFAULT;
445 goto free_old_hdr;
446 }
447 if (old_hdr->reply_len < 0) {
448 if (count >= SZ_SG_IO_HDR) {
449 sg_io_hdr_t *new_hdr;
450 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
451 if (!new_hdr) {
452 retval = -ENOMEM;
453 goto free_old_hdr;
454 }
455 retval =__copy_from_user
456 (new_hdr, buf, SZ_SG_IO_HDR);
457 req_pack_id = new_hdr->pack_id;
458 kfree(new_hdr);
459 if (retval) {
460 retval = -EFAULT;
461 goto free_old_hdr;
462 }
463 }
464 } else
465 req_pack_id = old_hdr->pack_id;
466 }
467 srp = sg_get_rq_mark(sfp, req_pack_id);
468 if (!srp) { /* now wait on packet to arrive */
469 if (atomic_read(&sdp->detaching)) {
470 retval = -ENODEV;
471 goto free_old_hdr;
472 }
473 if (filp->f_flags & O_NONBLOCK) {
474 retval = -EAGAIN;
475 goto free_old_hdr;
476 }
477 retval = wait_event_interruptible(sfp->read_wait,
478 (atomic_read(&sdp->detaching) ||
479 (srp = sg_get_rq_mark(sfp, req_pack_id))));
480 if (atomic_read(&sdp->detaching)) {
481 retval = -ENODEV;
482 goto free_old_hdr;
483 }
484 if (retval) {
485 /* -ERESTARTSYS as signal hit process */
486 goto free_old_hdr;
487 }
488 }
489 if (srp->header.interface_id != '\0') {
490 retval = sg_new_read(sfp, buf, count, srp);
491 goto free_old_hdr;
492 }
493
494 hp = &srp->header;
495 if (old_hdr == NULL) {
496 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
497 if (! old_hdr) {
498 retval = -ENOMEM;
499 goto free_old_hdr;
500 }
501 }
502 memset(old_hdr, 0, SZ_SG_HEADER);
503 old_hdr->reply_len = (int) hp->timeout;
504 old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
505 old_hdr->pack_id = hp->pack_id;
506 old_hdr->twelve_byte =
507 ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
508 old_hdr->target_status = hp->masked_status;
509 old_hdr->host_status = hp->host_status;
510 old_hdr->driver_status = hp->driver_status;
511 if ((CHECK_CONDITION & hp->masked_status) ||
512 (DRIVER_SENSE & hp->driver_status))
513 memcpy(old_hdr->sense_buffer, srp->sense_b,
514 sizeof (old_hdr->sense_buffer));
515 switch (hp->host_status) {
516 /* This setup of 'result' is for backward compatibility and is best
517 ignored by the user who should use target, host + driver status */
518 case DID_OK:
519 case DID_PASSTHROUGH:
520 case DID_SOFT_ERROR:
521 old_hdr->result = 0;
522 break;
523 case DID_NO_CONNECT:
524 case DID_BUS_BUSY:
525 case DID_TIME_OUT:
526 old_hdr->result = EBUSY;
527 break;
528 case DID_BAD_TARGET:
529 case DID_ABORT:
530 case DID_PARITY:
531 case DID_RESET:
532 case DID_BAD_INTR:
533 old_hdr->result = EIO;
534 break;
535 case DID_ERROR:
536 old_hdr->result = (srp->sense_b[0] == 0 &&
537 hp->masked_status == GOOD) ? 0 : EIO;
538 break;
539 default:
540 old_hdr->result = EIO;
541 break;
542 }
543
544 /* Now copy the result back to the user buffer. */
545 if (count >= SZ_SG_HEADER) {
546 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
547 retval = -EFAULT;
548 goto free_old_hdr;
549 }
550 buf += SZ_SG_HEADER;
551 if (count > old_hdr->reply_len)
552 count = old_hdr->reply_len;
553 if (count > SZ_SG_HEADER) {
554 if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
555 retval = -EFAULT;
556 goto free_old_hdr;
557 }
558 }
559 } else
560 count = (old_hdr->result == 0) ? 0 : -EIO;
561 sg_finish_rem_req(srp);
562 sg_remove_request(sfp, srp);
563 retval = count;
564 free_old_hdr:
565 kfree(old_hdr);
566 return retval;
567 }
568
569 static ssize_t
570 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
571 {
572 sg_io_hdr_t *hp = &srp->header;
573 int err = 0, err2;
574 int len;
575
576 if (count < SZ_SG_IO_HDR) {
577 err = -EINVAL;
578 goto err_out;
579 }
580 hp->sb_len_wr = 0;
581 if ((hp->mx_sb_len > 0) && hp->sbp) {
582 if ((CHECK_CONDITION & hp->masked_status) ||
583 (DRIVER_SENSE & hp->driver_status)) {
584 int sb_len = SCSI_SENSE_BUFFERSIZE;
585 sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
586 len = 8 + (int) srp->sense_b[7]; /* Additional sense length field */
587 len = (len > sb_len) ? sb_len : len;
588 if (copy_to_user(hp->sbp, srp->sense_b, len)) {
589 err = -EFAULT;
590 goto err_out;
591 }
592 hp->sb_len_wr = len;
593 }
594 }
595 if (hp->masked_status || hp->host_status || hp->driver_status)
596 hp->info |= SG_INFO_CHECK;
597 if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
598 err = -EFAULT;
599 goto err_out;
600 }
601 err_out:
602 err2 = sg_finish_rem_req(srp);
603 sg_remove_request(sfp, srp);
604 return err ? : err2 ? : count;
605 }
606
607 static ssize_t
608 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
609 {
610 int mxsize, cmd_size, k;
611 int input_size, blocking;
612 unsigned char opcode;
613 Sg_device *sdp;
614 Sg_fd *sfp;
615 Sg_request *srp;
616 struct sg_header old_hdr;
617 sg_io_hdr_t *hp;
618 unsigned char cmnd[SG_MAX_CDB_SIZE];
619 int retval;
620
621 retval = sg_check_file_access(filp, __func__);
622 if (retval)
623 return retval;
624
625 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
626 return -ENXIO;
627 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
628 "sg_write: count=%d\n", (int) count));
629 if (atomic_read(&sdp->detaching))
630 return -ENODEV;
631 if (!((filp->f_flags & O_NONBLOCK) ||
632 scsi_block_when_processing_errors(sdp->device)))
633 return -ENXIO;
634
635 if (!access_ok(buf, count))
636 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
637 if (count < SZ_SG_HEADER)
638 return -EIO;
639 if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
640 return -EFAULT;
641 blocking = !(filp->f_flags & O_NONBLOCK);
642 if (old_hdr.reply_len < 0)
643 return sg_new_write(sfp, filp, buf, count,
644 blocking, 0, 0, NULL);
645 if (count < (SZ_SG_HEADER + 6))
646 return -EIO; /* The minimum scsi command length is 6 bytes. */
647
648 if (!(srp = sg_add_request(sfp))) {
649 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
650 "sg_write: queue full\n"));
651 return -EDOM;
652 }
653 buf += SZ_SG_HEADER;
654 __get_user(opcode, buf);
655 mutex_lock(&sfp->f_mutex);
656 if (sfp->next_cmd_len > 0) {
657 cmd_size = sfp->next_cmd_len;
658 sfp->next_cmd_len = 0; /* reset so only this write() effected */
659 } else {
660 cmd_size = COMMAND_SIZE(opcode); /* based on SCSI command group */
661 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
662 cmd_size = 12;
663 }
664 mutex_unlock(&sfp->f_mutex);
665 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
666 "sg_write: scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
667 /* Determine buffer size. */
668 input_size = count - cmd_size;
669 mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
670 mxsize -= SZ_SG_HEADER;
671 input_size -= SZ_SG_HEADER;
672 if (input_size < 0) {
673 sg_remove_request(sfp, srp);
674 return -EIO; /* User did not pass enough bytes for this command. */
675 }
676 hp = &srp->header;
677 hp->interface_id = '\0'; /* indicator of old interface tunnelled */
678 hp->cmd_len = (unsigned char) cmd_size;
679 hp->iovec_count = 0;
680 hp->mx_sb_len = 0;
681 if (input_size > 0)
682 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
683 SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
684 else
685 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
686 hp->dxfer_len = mxsize;
687 if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
688 (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
689 hp->dxferp = (char __user *)buf + cmd_size;
690 else
691 hp->dxferp = NULL;
692 hp->sbp = NULL;
693 hp->timeout = old_hdr.reply_len; /* structure abuse ... */
694 hp->flags = input_size; /* structure abuse ... */
695 hp->pack_id = old_hdr.pack_id;
696 hp->usr_ptr = NULL;
697 if (__copy_from_user(cmnd, buf, cmd_size))
698 return -EFAULT;
699 /*
700 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
701 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
702 * is a non-zero input_size, so emit a warning.
703 */
704 if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
705 printk_ratelimited(KERN_WARNING
706 "sg_write: data in/out %d/%d bytes "
707 "for SCSI command 0x%x-- guessing "
708 "data in;\n program %s not setting "
709 "count and/or reply_len properly\n",
710 old_hdr.reply_len - (int)SZ_SG_HEADER,
711 input_size, (unsigned int) cmnd[0],
712 current->comm);
713 }
714 k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
715 return (k < 0) ? k : count;
716 }
717
718 static ssize_t
719 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
720 size_t count, int blocking, int read_only, int sg_io_owned,
721 Sg_request **o_srp)
722 {
723 int k;
724 Sg_request *srp;
725 sg_io_hdr_t *hp;
726 unsigned char cmnd[SG_MAX_CDB_SIZE];
727 int timeout;
728 unsigned long ul_timeout;
729
730 if (count < SZ_SG_IO_HDR)
731 return -EINVAL;
732 if (!access_ok(buf, count))
733 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
734
735 sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
736 if (!(srp = sg_add_request(sfp))) {
737 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
738 "sg_new_write: queue full\n"));
739 return -EDOM;
740 }
741 srp->sg_io_owned = sg_io_owned;
742 hp = &srp->header;
743 if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
744 sg_remove_request(sfp, srp);
745 return -EFAULT;
746 }
747 if (hp->interface_id != 'S') {
748 sg_remove_request(sfp, srp);
749 return -ENOSYS;
750 }
751 if (hp->flags & SG_FLAG_MMAP_IO) {
752 if (hp->dxfer_len > sfp->reserve.bufflen) {
753 sg_remove_request(sfp, srp);
754 return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
755 }
756 if (hp->flags & SG_FLAG_DIRECT_IO) {
757 sg_remove_request(sfp, srp);
758 return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
759 }
760 if (sfp->res_in_use) {
761 sg_remove_request(sfp, srp);
762 return -EBUSY; /* reserve buffer already being used */
763 }
764 }
765 ul_timeout = msecs_to_jiffies(srp->header.timeout);
766 timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
767 if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
768 sg_remove_request(sfp, srp);
769 return -EMSGSIZE;
770 }
771 if (!access_ok(hp->cmdp, hp->cmd_len)) {
772 sg_remove_request(sfp, srp);
773 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
774 }
775 if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
776 sg_remove_request(sfp, srp);
777 return -EFAULT;
778 }
779 if (read_only && sg_allow_access(file, cmnd)) {
780 sg_remove_request(sfp, srp);
781 return -EPERM;
782 }
783 k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
784 if (k < 0)
785 return k;
786 if (o_srp)
787 *o_srp = srp;
788 return count;
789 }
790
791 static int
792 sg_common_write(Sg_fd * sfp, Sg_request * srp,
793 unsigned char *cmnd, int timeout, int blocking)
794 {
795 int k, at_head;
796 Sg_device *sdp = sfp->parentdp;
797 sg_io_hdr_t *hp = &srp->header;
798
799 srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
800 hp->status = 0;
801 hp->masked_status = 0;
802 hp->msg_status = 0;
803 hp->info = 0;
804 hp->host_status = 0;
805 hp->driver_status = 0;
806 hp->resid = 0;
807 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
808 "sg_common_write: scsi opcode=0x%02x, cmd_size=%d\n",
809 (int) cmnd[0], (int) hp->cmd_len));
810
811 if (hp->dxfer_len >= SZ_256M)
812 return -EINVAL;
813
814 k = sg_start_req(srp, cmnd);
815 if (k) {
816 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
817 "sg_common_write: start_req err=%d\n", k));
818 sg_finish_rem_req(srp);
819 sg_remove_request(sfp, srp);
820 return k; /* probably out of space --> ENOMEM */
821 }
822 if (atomic_read(&sdp->detaching)) {
823 if (srp->bio) {
824 scsi_req_free_cmd(scsi_req(srp->rq));
825 blk_put_request(srp->rq);
826 srp->rq = NULL;
827 }
828
829 sg_finish_rem_req(srp);
830 sg_remove_request(sfp, srp);
831 return -ENODEV;
832 }
833
834 hp->duration = jiffies_to_msecs(jiffies);
835 if (hp->interface_id != '\0' && /* v3 (or later) interface */
836 (SG_FLAG_Q_AT_TAIL & hp->flags))
837 at_head = 0;
838 else
839 at_head = 1;
840
841 srp->rq->timeout = timeout;
842 kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
843 blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
844 srp->rq, at_head, sg_rq_end_io);
845 return 0;
846 }
847
848 static int srp_done(Sg_fd *sfp, Sg_request *srp)
849 {
850 unsigned long flags;
851 int ret;
852
853 read_lock_irqsave(&sfp->rq_list_lock, flags);
854 ret = srp->done;
855 read_unlock_irqrestore(&sfp->rq_list_lock, flags);
856 return ret;
857 }
858
859 static int max_sectors_bytes(struct request_queue *q)
860 {
861 unsigned int max_sectors = queue_max_sectors(q);
862
863 max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
864
865 return max_sectors << 9;
866 }
867
868 static void
869 sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
870 {
871 Sg_request *srp;
872 int val;
873 unsigned int ms;
874
875 val = 0;
876 list_for_each_entry(srp, &sfp->rq_list, entry) {
877 if (val >= SG_MAX_QUEUE)
878 break;
879 rinfo[val].req_state = srp->done + 1;
880 rinfo[val].problem =
881 srp->header.masked_status &
882 srp->header.host_status &
883 srp->header.driver_status;
884 if (srp->done)
885 rinfo[val].duration =
886 srp->header.duration;
887 else {
888 ms = jiffies_to_msecs(jiffies);
889 rinfo[val].duration =
890 (ms > srp->header.duration) ?
891 (ms - srp->header.duration) : 0;
892 }
893 rinfo[val].orphan = srp->orphan;
894 rinfo[val].sg_io_owned = srp->sg_io_owned;
895 rinfo[val].pack_id = srp->header.pack_id;
896 rinfo[val].usr_ptr = srp->header.usr_ptr;
897 val++;
898 }
899 }
900
901 static long
902 sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
903 {
904 void __user *p = (void __user *)arg;
905 int __user *ip = p;
906 int result, val, read_only;
907 Sg_device *sdp;
908 Sg_fd *sfp;
909 Sg_request *srp;
910 unsigned long iflags;
911
912 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
913 return -ENXIO;
914
915 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
916 "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
917 read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
918
919 switch (cmd_in) {
920 case SG_IO:
921 if (atomic_read(&sdp->detaching))
922 return -ENODEV;
923 if (!scsi_block_when_processing_errors(sdp->device))
924 return -ENXIO;
925 if (!access_ok(p, SZ_SG_IO_HDR))
926 return -EFAULT;
927 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
928 1, read_only, 1, &srp);
929 if (result < 0)
930 return result;
931 result = wait_event_interruptible(sfp->read_wait,
932 (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
933 if (atomic_read(&sdp->detaching))
934 return -ENODEV;
935 write_lock_irq(&sfp->rq_list_lock);
936 if (srp->done) {
937 srp->done = 2;
938 write_unlock_irq(&sfp->rq_list_lock);
939 result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
940 return (result < 0) ? result : 0;
941 }
942 srp->orphan = 1;
943 write_unlock_irq(&sfp->rq_list_lock);
944 return result; /* -ERESTARTSYS because signal hit process */
945 case SG_SET_TIMEOUT:
946 result = get_user(val, ip);
947 if (result)
948 return result;
949 if (val < 0)
950 return -EIO;
951 if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
952 val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
953 INT_MAX);
954 sfp->timeout_user = val;
955 sfp->timeout = mult_frac(val, HZ, USER_HZ);
956
957 return 0;
958 case SG_GET_TIMEOUT: /* N.B. User receives timeout as return value */
959 /* strange ..., for backward compatibility */
960 return sfp->timeout_user;
961 case SG_SET_FORCE_LOW_DMA:
962 /*
963 * N.B. This ioctl never worked properly, but failed to
964 * return an error value. So returning '0' to keep compability
965 * with legacy applications.
966 */
967 return 0;
968 case SG_GET_LOW_DMA:
969 return put_user((int) sdp->device->host->unchecked_isa_dma, ip);
970 case SG_GET_SCSI_ID:
971 if (!access_ok(p, sizeof (sg_scsi_id_t)))
972 return -EFAULT;
973 else {
974 sg_scsi_id_t __user *sg_idp = p;
975
976 if (atomic_read(&sdp->detaching))
977 return -ENODEV;
978 __put_user((int) sdp->device->host->host_no,
979 &sg_idp->host_no);
980 __put_user((int) sdp->device->channel,
981 &sg_idp->channel);
982 __put_user((int) sdp->device->id, &sg_idp->scsi_id);
983 __put_user((int) sdp->device->lun, &sg_idp->lun);
984 __put_user((int) sdp->device->type, &sg_idp->scsi_type);
985 __put_user((short) sdp->device->host->cmd_per_lun,
986 &sg_idp->h_cmd_per_lun);
987 __put_user((short) sdp->device->queue_depth,
988 &sg_idp->d_queue_depth);
989 __put_user(0, &sg_idp->unused[0]);
990 __put_user(0, &sg_idp->unused[1]);
991 return 0;
992 }
993 case SG_SET_FORCE_PACK_ID:
994 result = get_user(val, ip);
995 if (result)
996 return result;
997 sfp->force_packid = val ? 1 : 0;
998 return 0;
999 case SG_GET_PACK_ID:
1000 if (!access_ok(ip, sizeof (int)))
1001 return -EFAULT;
1002 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1003 list_for_each_entry(srp, &sfp->rq_list, entry) {
1004 if ((1 == srp->done) && (!srp->sg_io_owned)) {
1005 read_unlock_irqrestore(&sfp->rq_list_lock,
1006 iflags);
1007 __put_user(srp->header.pack_id, ip);
1008 return 0;
1009 }
1010 }
1011 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1012 __put_user(-1, ip);
1013 return 0;
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 if (!access_ok(p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
1082 return -EFAULT;
1083 else {
1084 sg_req_info_t *rinfo;
1085
1086 rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
1087 GFP_KERNEL);
1088 if (!rinfo)
1089 return -ENOMEM;
1090 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1091 sg_fill_request_table(sfp, rinfo);
1092 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1093 result = __copy_to_user(p, rinfo,
1094 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1095 result = result ? -EFAULT : 0;
1096 kfree(rinfo);
1097 return result;
1098 }
1099 case SG_EMULATED_HOST:
1100 if (atomic_read(&sdp->detaching))
1101 return -ENODEV;
1102 return put_user(sdp->device->host->hostt->emulated, ip);
1103 case SCSI_IOCTL_SEND_COMMAND:
1104 if (atomic_read(&sdp->detaching))
1105 return -ENODEV;
1106 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1107 case SG_SET_DEBUG:
1108 result = get_user(val, ip);
1109 if (result)
1110 return result;
1111 sdp->sgdebug = (char) val;
1112 return 0;
1113 case BLKSECTGET:
1114 return put_user(max_sectors_bytes(sdp->device->request_queue),
1115 ip);
1116 case BLKTRACESETUP:
1117 return blk_trace_setup(sdp->device->request_queue,
1118 sdp->disk->disk_name,
1119 MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1120 NULL, p);
1121 case BLKTRACESTART:
1122 return blk_trace_startstop(sdp->device->request_queue, 1);
1123 case BLKTRACESTOP:
1124 return blk_trace_startstop(sdp->device->request_queue, 0);
1125 case BLKTRACETEARDOWN:
1126 return blk_trace_remove(sdp->device->request_queue);
1127 case SCSI_IOCTL_GET_IDLUN:
1128 case SCSI_IOCTL_GET_BUS_NUMBER:
1129 case SCSI_IOCTL_PROBE_HOST:
1130 case SG_GET_TRANSFORM:
1131 case SG_SCSI_RESET:
1132 if (atomic_read(&sdp->detaching))
1133 return -ENODEV;
1134 break;
1135 default:
1136 if (read_only)
1137 return -EPERM; /* don't know so take safe approach */
1138 break;
1139 }
1140
1141 result = scsi_ioctl_block_when_processing_errors(sdp->device,
1142 cmd_in, filp->f_flags & O_NDELAY);
1143 if (result)
1144 return result;
1145 return scsi_ioctl(sdp->device, cmd_in, p);
1146 }
1147
1148 #ifdef CONFIG_COMPAT
1149 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1150 {
1151 Sg_device *sdp;
1152 Sg_fd *sfp;
1153 struct scsi_device *sdev;
1154
1155 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1156 return -ENXIO;
1157
1158 sdev = sdp->device;
1159 if (sdev->host->hostt->compat_ioctl) {
1160 int ret;
1161
1162 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1163
1164 return ret;
1165 }
1166
1167 return -ENOIOCTLCMD;
1168 }
1169 #endif
1170
1171 static __poll_t
1172 sg_poll(struct file *filp, poll_table * wait)
1173 {
1174 __poll_t res = 0;
1175 Sg_device *sdp;
1176 Sg_fd *sfp;
1177 Sg_request *srp;
1178 int count = 0;
1179 unsigned long iflags;
1180
1181 sfp = filp->private_data;
1182 if (!sfp)
1183 return EPOLLERR;
1184 sdp = sfp->parentdp;
1185 if (!sdp)
1186 return EPOLLERR;
1187 poll_wait(filp, &sfp->read_wait, wait);
1188 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1189 list_for_each_entry(srp, &sfp->rq_list, entry) {
1190 /* if any read waiting, flag it */
1191 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1192 res = EPOLLIN | EPOLLRDNORM;
1193 ++count;
1194 }
1195 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1196
1197 if (atomic_read(&sdp->detaching))
1198 res |= EPOLLHUP;
1199 else if (!sfp->cmd_q) {
1200 if (0 == count)
1201 res |= EPOLLOUT | EPOLLWRNORM;
1202 } else if (count < SG_MAX_QUEUE)
1203 res |= EPOLLOUT | EPOLLWRNORM;
1204 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1205 "sg_poll: res=0x%x\n", (__force u32) res));
1206 return res;
1207 }
1208
1209 static int
1210 sg_fasync(int fd, struct file *filp, int mode)
1211 {
1212 Sg_device *sdp;
1213 Sg_fd *sfp;
1214
1215 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1216 return -ENXIO;
1217 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1218 "sg_fasync: mode=%d\n", mode));
1219
1220 return fasync_helper(fd, filp, mode, &sfp->async_qp);
1221 }
1222
1223 static vm_fault_t
1224 sg_vma_fault(struct vm_fault *vmf)
1225 {
1226 struct vm_area_struct *vma = vmf->vma;
1227 Sg_fd *sfp;
1228 unsigned long offset, len, sa;
1229 Sg_scatter_hold *rsv_schp;
1230 int k, length;
1231
1232 if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1233 return VM_FAULT_SIGBUS;
1234 rsv_schp = &sfp->reserve;
1235 offset = vmf->pgoff << PAGE_SHIFT;
1236 if (offset >= rsv_schp->bufflen)
1237 return VM_FAULT_SIGBUS;
1238 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1239 "sg_vma_fault: offset=%lu, scatg=%d\n",
1240 offset, rsv_schp->k_use_sg));
1241 sa = vma->vm_start;
1242 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1243 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1244 len = vma->vm_end - sa;
1245 len = (len < length) ? len : length;
1246 if (offset < len) {
1247 struct page *page = nth_page(rsv_schp->pages[k],
1248 offset >> PAGE_SHIFT);
1249 get_page(page); /* increment page count */
1250 vmf->page = page;
1251 return 0; /* success */
1252 }
1253 sa += len;
1254 offset -= len;
1255 }
1256
1257 return VM_FAULT_SIGBUS;
1258 }
1259
1260 static const struct vm_operations_struct sg_mmap_vm_ops = {
1261 .fault = sg_vma_fault,
1262 };
1263
1264 static int
1265 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1266 {
1267 Sg_fd *sfp;
1268 unsigned long req_sz, len, sa;
1269 Sg_scatter_hold *rsv_schp;
1270 int k, length;
1271 int ret = 0;
1272
1273 if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1274 return -ENXIO;
1275 req_sz = vma->vm_end - vma->vm_start;
1276 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1277 "sg_mmap starting, vm_start=%p, len=%d\n",
1278 (void *) vma->vm_start, (int) req_sz));
1279 if (vma->vm_pgoff)
1280 return -EINVAL; /* want no offset */
1281 rsv_schp = &sfp->reserve;
1282 mutex_lock(&sfp->f_mutex);
1283 if (req_sz > rsv_schp->bufflen) {
1284 ret = -ENOMEM; /* cannot map more than reserved buffer */
1285 goto out;
1286 }
1287
1288 sa = vma->vm_start;
1289 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1290 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1291 len = vma->vm_end - sa;
1292 len = (len < length) ? len : length;
1293 sa += len;
1294 }
1295
1296 sfp->mmap_called = 1;
1297 vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
1298 vma->vm_private_data = sfp;
1299 vma->vm_ops = &sg_mmap_vm_ops;
1300 out:
1301 mutex_unlock(&sfp->f_mutex);
1302 return ret;
1303 }
1304
1305 static void
1306 sg_rq_end_io_usercontext(struct work_struct *work)
1307 {
1308 struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1309 struct sg_fd *sfp = srp->parentfp;
1310
1311 sg_finish_rem_req(srp);
1312 sg_remove_request(sfp, srp);
1313 kref_put(&sfp->f_ref, sg_remove_sfp);
1314 }
1315
1316 /*
1317 * This function is a "bottom half" handler that is called by the mid
1318 * level when a command is completed (or has failed).
1319 */
1320 static void
1321 sg_rq_end_io(struct request *rq, blk_status_t status)
1322 {
1323 struct sg_request *srp = rq->end_io_data;
1324 struct scsi_request *req = scsi_req(rq);
1325 Sg_device *sdp;
1326 Sg_fd *sfp;
1327 unsigned long iflags;
1328 unsigned int ms;
1329 char *sense;
1330 int result, resid, done = 1;
1331
1332 if (WARN_ON(srp->done != 0))
1333 return;
1334
1335 sfp = srp->parentfp;
1336 if (WARN_ON(sfp == NULL))
1337 return;
1338
1339 sdp = sfp->parentdp;
1340 if (unlikely(atomic_read(&sdp->detaching)))
1341 pr_info("%s: device detaching\n", __func__);
1342
1343 sense = req->sense;
1344 result = req->result;
1345 resid = req->resid_len;
1346
1347 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1348 "sg_cmd_done: pack_id=%d, res=0x%x\n",
1349 srp->header.pack_id, result));
1350 srp->header.resid = resid;
1351 ms = jiffies_to_msecs(jiffies);
1352 srp->header.duration = (ms > srp->header.duration) ?
1353 (ms - srp->header.duration) : 0;
1354 if (0 != result) {
1355 struct scsi_sense_hdr sshdr;
1356
1357 srp->header.status = 0xff & result;
1358 srp->header.masked_status = status_byte(result);
1359 srp->header.msg_status = msg_byte(result);
1360 srp->header.host_status = host_byte(result);
1361 srp->header.driver_status = driver_byte(result);
1362 if ((sdp->sgdebug > 0) &&
1363 ((CHECK_CONDITION == srp->header.masked_status) ||
1364 (COMMAND_TERMINATED == srp->header.masked_status)))
1365 __scsi_print_sense(sdp->device, __func__, sense,
1366 SCSI_SENSE_BUFFERSIZE);
1367
1368 /* Following if statement is a patch supplied by Eric Youngdale */
1369 if (driver_byte(result) != 0
1370 && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1371 && !scsi_sense_is_deferred(&sshdr)
1372 && sshdr.sense_key == UNIT_ATTENTION
1373 && sdp->device->removable) {
1374 /* Detected possible disc change. Set the bit - this */
1375 /* may be used if there are filesystems using this device */
1376 sdp->device->changed = 1;
1377 }
1378 }
1379
1380 if (req->sense_len)
1381 memcpy(srp->sense_b, req->sense, SCSI_SENSE_BUFFERSIZE);
1382
1383 /* Rely on write phase to clean out srp status values, so no "else" */
1384
1385 /*
1386 * Free the request as soon as it is complete so that its resources
1387 * can be reused without waiting for userspace to read() the
1388 * result. But keep the associated bio (if any) around until
1389 * blk_rq_unmap_user() can be called from user context.
1390 */
1391 srp->rq = NULL;
1392 scsi_req_free_cmd(scsi_req(rq));
1393 blk_put_request(rq);
1394
1395 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1396 if (unlikely(srp->orphan)) {
1397 if (sfp->keep_orphan)
1398 srp->sg_io_owned = 0;
1399 else
1400 done = 0;
1401 }
1402 srp->done = done;
1403 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1404
1405 if (likely(done)) {
1406 /* Now wake up any sg_read() that is waiting for this
1407 * packet.
1408 */
1409 wake_up_interruptible(&sfp->read_wait);
1410 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1411 kref_put(&sfp->f_ref, sg_remove_sfp);
1412 } else {
1413 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1414 schedule_work(&srp->ew.work);
1415 }
1416 }
1417
1418 static const struct file_operations sg_fops = {
1419 .owner = THIS_MODULE,
1420 .read = sg_read,
1421 .write = sg_write,
1422 .poll = sg_poll,
1423 .unlocked_ioctl = sg_ioctl,
1424 #ifdef CONFIG_COMPAT
1425 .compat_ioctl = sg_compat_ioctl,
1426 #endif
1427 .open = sg_open,
1428 .mmap = sg_mmap,
1429 .release = sg_release,
1430 .fasync = sg_fasync,
1431 .llseek = no_llseek,
1432 };
1433
1434 static struct class *sg_sysfs_class;
1435
1436 static int sg_sysfs_valid = 0;
1437
1438 static Sg_device *
1439 sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1440 {
1441 struct request_queue *q = scsidp->request_queue;
1442 Sg_device *sdp;
1443 unsigned long iflags;
1444 int error;
1445 u32 k;
1446
1447 sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1448 if (!sdp) {
1449 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1450 "failure\n", __func__);
1451 return ERR_PTR(-ENOMEM);
1452 }
1453
1454 idr_preload(GFP_KERNEL);
1455 write_lock_irqsave(&sg_index_lock, iflags);
1456
1457 error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1458 if (error < 0) {
1459 if (error == -ENOSPC) {
1460 sdev_printk(KERN_WARNING, scsidp,
1461 "Unable to attach sg device type=%d, minor number exceeds %d\n",
1462 scsidp->type, SG_MAX_DEVS - 1);
1463 error = -ENODEV;
1464 } else {
1465 sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1466 "allocation Sg_device failure: %d\n",
1467 __func__, error);
1468 }
1469 goto out_unlock;
1470 }
1471 k = error;
1472
1473 SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1474 "sg_alloc: dev=%d \n", k));
1475 sprintf(disk->disk_name, "sg%d", k);
1476 disk->first_minor = k;
1477 sdp->disk = disk;
1478 sdp->device = scsidp;
1479 mutex_init(&sdp->open_rel_lock);
1480 INIT_LIST_HEAD(&sdp->sfds);
1481 init_waitqueue_head(&sdp->open_wait);
1482 atomic_set(&sdp->detaching, 0);
1483 rwlock_init(&sdp->sfd_lock);
1484 sdp->sg_tablesize = queue_max_segments(q);
1485 sdp->index = k;
1486 kref_init(&sdp->d_ref);
1487 error = 0;
1488
1489 out_unlock:
1490 write_unlock_irqrestore(&sg_index_lock, iflags);
1491 idr_preload_end();
1492
1493 if (error) {
1494 kfree(sdp);
1495 return ERR_PTR(error);
1496 }
1497 return sdp;
1498 }
1499
1500 static int
1501 sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
1502 {
1503 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1504 struct gendisk *disk;
1505 Sg_device *sdp = NULL;
1506 struct cdev * cdev = NULL;
1507 int error;
1508 unsigned long iflags;
1509
1510 disk = alloc_disk(1);
1511 if (!disk) {
1512 pr_warn("%s: alloc_disk failed\n", __func__);
1513 return -ENOMEM;
1514 }
1515 disk->major = SCSI_GENERIC_MAJOR;
1516
1517 error = -ENOMEM;
1518 cdev = cdev_alloc();
1519 if (!cdev) {
1520 pr_warn("%s: cdev_alloc failed\n", __func__);
1521 goto out;
1522 }
1523 cdev->owner = THIS_MODULE;
1524 cdev->ops = &sg_fops;
1525
1526 sdp = sg_alloc(disk, scsidp);
1527 if (IS_ERR(sdp)) {
1528 pr_warn("%s: sg_alloc failed\n", __func__);
1529 error = PTR_ERR(sdp);
1530 goto out;
1531 }
1532
1533 error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1534 if (error)
1535 goto cdev_add_err;
1536
1537 sdp->cdev = cdev;
1538 if (sg_sysfs_valid) {
1539 struct device *sg_class_member;
1540
1541 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1542 MKDEV(SCSI_GENERIC_MAJOR,
1543 sdp->index),
1544 sdp, "%s", disk->disk_name);
1545 if (IS_ERR(sg_class_member)) {
1546 pr_err("%s: device_create failed\n", __func__);
1547 error = PTR_ERR(sg_class_member);
1548 goto cdev_add_err;
1549 }
1550 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1551 &sg_class_member->kobj, "generic");
1552 if (error)
1553 pr_err("%s: unable to make symlink 'generic' back "
1554 "to sg%d\n", __func__, sdp->index);
1555 } else
1556 pr_warn("%s: sg_sys Invalid\n", __func__);
1557
1558 sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1559 "type %d\n", sdp->index, scsidp->type);
1560
1561 dev_set_drvdata(cl_dev, sdp);
1562
1563 return 0;
1564
1565 cdev_add_err:
1566 write_lock_irqsave(&sg_index_lock, iflags);
1567 idr_remove(&sg_index_idr, sdp->index);
1568 write_unlock_irqrestore(&sg_index_lock, iflags);
1569 kfree(sdp);
1570
1571 out:
1572 put_disk(disk);
1573 if (cdev)
1574 cdev_del(cdev);
1575 return error;
1576 }
1577
1578 static void
1579 sg_device_destroy(struct kref *kref)
1580 {
1581 struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1582 unsigned long flags;
1583
1584 /* CAUTION! Note that the device can still be found via idr_find()
1585 * even though the refcount is 0. Therefore, do idr_remove() BEFORE
1586 * any other cleanup.
1587 */
1588
1589 write_lock_irqsave(&sg_index_lock, flags);
1590 idr_remove(&sg_index_idr, sdp->index);
1591 write_unlock_irqrestore(&sg_index_lock, flags);
1592
1593 SCSI_LOG_TIMEOUT(3,
1594 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1595
1596 put_disk(sdp->disk);
1597 kfree(sdp);
1598 }
1599
1600 static void
1601 sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
1602 {
1603 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1604 Sg_device *sdp = dev_get_drvdata(cl_dev);
1605 unsigned long iflags;
1606 Sg_fd *sfp;
1607 int val;
1608
1609 if (!sdp)
1610 return;
1611 /* want sdp->detaching non-zero as soon as possible */
1612 val = atomic_inc_return(&sdp->detaching);
1613 if (val > 1)
1614 return; /* only want to do following once per device */
1615
1616 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1617 "%s\n", __func__));
1618
1619 read_lock_irqsave(&sdp->sfd_lock, iflags);
1620 list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1621 wake_up_interruptible_all(&sfp->read_wait);
1622 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1623 }
1624 wake_up_interruptible_all(&sdp->open_wait);
1625 read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1626
1627 sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1628 device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1629 cdev_del(sdp->cdev);
1630 sdp->cdev = NULL;
1631
1632 kref_put(&sdp->d_ref, sg_device_destroy);
1633 }
1634
1635 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1636 module_param_named(def_reserved_size, def_reserved_size, int,
1637 S_IRUGO | S_IWUSR);
1638 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1639
1640 MODULE_AUTHOR("Douglas Gilbert");
1641 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1642 MODULE_LICENSE("GPL");
1643 MODULE_VERSION(SG_VERSION_STR);
1644 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1645
1646 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1647 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1648 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1649 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1650
1651 static int __init
1652 init_sg(void)
1653 {
1654 int rc;
1655
1656 if (scatter_elem_sz < PAGE_SIZE) {
1657 scatter_elem_sz = PAGE_SIZE;
1658 scatter_elem_sz_prev = scatter_elem_sz;
1659 }
1660 if (def_reserved_size >= 0)
1661 sg_big_buff = def_reserved_size;
1662 else
1663 def_reserved_size = sg_big_buff;
1664
1665 rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1666 SG_MAX_DEVS, "sg");
1667 if (rc)
1668 return rc;
1669 sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1670 if ( IS_ERR(sg_sysfs_class) ) {
1671 rc = PTR_ERR(sg_sysfs_class);
1672 goto err_out;
1673 }
1674 sg_sysfs_valid = 1;
1675 rc = scsi_register_interface(&sg_interface);
1676 if (0 == rc) {
1677 #ifdef CONFIG_SCSI_PROC_FS
1678 sg_proc_init();
1679 #endif /* CONFIG_SCSI_PROC_FS */
1680 return 0;
1681 }
1682 class_destroy(sg_sysfs_class);
1683 err_out:
1684 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1685 return rc;
1686 }
1687
1688 static void __exit
1689 exit_sg(void)
1690 {
1691 #ifdef CONFIG_SCSI_PROC_FS
1692 remove_proc_subtree("scsi/sg", NULL);
1693 #endif /* CONFIG_SCSI_PROC_FS */
1694 scsi_unregister_interface(&sg_interface);
1695 class_destroy(sg_sysfs_class);
1696 sg_sysfs_valid = 0;
1697 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1698 SG_MAX_DEVS);
1699 idr_destroy(&sg_index_idr);
1700 }
1701
1702 static int
1703 sg_start_req(Sg_request *srp, unsigned char *cmd)
1704 {
1705 int res;
1706 struct request *rq;
1707 struct scsi_request *req;
1708 Sg_fd *sfp = srp->parentfp;
1709 sg_io_hdr_t *hp = &srp->header;
1710 int dxfer_len = (int) hp->dxfer_len;
1711 int dxfer_dir = hp->dxfer_direction;
1712 unsigned int iov_count = hp->iovec_count;
1713 Sg_scatter_hold *req_schp = &srp->data;
1714 Sg_scatter_hold *rsv_schp = &sfp->reserve;
1715 struct request_queue *q = sfp->parentdp->device->request_queue;
1716 struct rq_map_data *md, map_data;
1717 int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1718 unsigned char *long_cmdp = NULL;
1719
1720 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1721 "sg_start_req: dxfer_len=%d\n",
1722 dxfer_len));
1723
1724 if (hp->cmd_len > BLK_MAX_CDB) {
1725 long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
1726 if (!long_cmdp)
1727 return -ENOMEM;
1728 }
1729
1730 /*
1731 * NOTE
1732 *
1733 * With scsi-mq enabled, there are a fixed number of preallocated
1734 * requests equal in number to shost->can_queue. If all of the
1735 * preallocated requests are already in use, then blk_get_request()
1736 * will sleep until an active command completes, freeing up a request.
1737 * Although waiting in an asynchronous interface is less than ideal, we
1738 * do not want to use BLK_MQ_REQ_NOWAIT here because userspace might
1739 * not expect an EWOULDBLOCK from this condition.
1740 */
1741 rq = blk_get_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
1742 REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
1743 if (IS_ERR(rq)) {
1744 kfree(long_cmdp);
1745 return PTR_ERR(rq);
1746 }
1747 req = scsi_req(rq);
1748
1749 if (hp->cmd_len > BLK_MAX_CDB)
1750 req->cmd = long_cmdp;
1751 memcpy(req->cmd, cmd, hp->cmd_len);
1752 req->cmd_len = hp->cmd_len;
1753
1754 srp->rq = rq;
1755 rq->end_io_data = srp;
1756 req->retries = SG_DEFAULT_RETRIES;
1757
1758 if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1759 return 0;
1760
1761 if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1762 dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1763 !sfp->parentdp->device->host->unchecked_isa_dma &&
1764 blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1765 md = NULL;
1766 else
1767 md = &map_data;
1768
1769 if (md) {
1770 mutex_lock(&sfp->f_mutex);
1771 if (dxfer_len <= rsv_schp->bufflen &&
1772 !sfp->res_in_use) {
1773 sfp->res_in_use = 1;
1774 sg_link_reserve(sfp, srp, dxfer_len);
1775 } else if (hp->flags & SG_FLAG_MMAP_IO) {
1776 res = -EBUSY; /* sfp->res_in_use == 1 */
1777 if (dxfer_len > rsv_schp->bufflen)
1778 res = -ENOMEM;
1779 mutex_unlock(&sfp->f_mutex);
1780 return res;
1781 } else {
1782 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1783 if (res) {
1784 mutex_unlock(&sfp->f_mutex);
1785 return res;
1786 }
1787 }
1788 mutex_unlock(&sfp->f_mutex);
1789
1790 md->pages = req_schp->pages;
1791 md->page_order = req_schp->page_order;
1792 md->nr_entries = req_schp->k_use_sg;
1793 md->offset = 0;
1794 md->null_mapped = hp->dxferp ? 0 : 1;
1795 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1796 md->from_user = 1;
1797 else
1798 md->from_user = 0;
1799 }
1800
1801 if (iov_count) {
1802 struct iovec *iov = NULL;
1803 struct iov_iter i;
1804
1805 res = import_iovec(rw, hp->dxferp, iov_count, 0, &iov, &i);
1806 if (res < 0)
1807 return res;
1808
1809 iov_iter_truncate(&i, hp->dxfer_len);
1810 if (!iov_iter_count(&i)) {
1811 kfree(iov);
1812 return -EINVAL;
1813 }
1814
1815 res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
1816 kfree(iov);
1817 } else
1818 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1819 hp->dxfer_len, GFP_ATOMIC);
1820
1821 if (!res) {
1822 srp->bio = rq->bio;
1823
1824 if (!md) {
1825 req_schp->dio_in_use = 1;
1826 hp->info |= SG_INFO_DIRECT_IO;
1827 }
1828 }
1829 return res;
1830 }
1831
1832 static int
1833 sg_finish_rem_req(Sg_request *srp)
1834 {
1835 int ret = 0;
1836
1837 Sg_fd *sfp = srp->parentfp;
1838 Sg_scatter_hold *req_schp = &srp->data;
1839
1840 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1841 "sg_finish_rem_req: res_used=%d\n",
1842 (int) srp->res_used));
1843 if (srp->bio)
1844 ret = blk_rq_unmap_user(srp->bio);
1845
1846 if (srp->rq) {
1847 scsi_req_free_cmd(scsi_req(srp->rq));
1848 blk_put_request(srp->rq);
1849 }
1850
1851 if (srp->res_used)
1852 sg_unlink_reserve(sfp, srp);
1853 else
1854 sg_remove_scat(sfp, req_schp);
1855
1856 return ret;
1857 }
1858
1859 static int
1860 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1861 {
1862 int sg_bufflen = tablesize * sizeof(struct page *);
1863 gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1864
1865 schp->pages = kzalloc(sg_bufflen, gfp_flags);
1866 if (!schp->pages)
1867 return -ENOMEM;
1868 schp->sglist_len = sg_bufflen;
1869 return tablesize; /* number of scat_gath elements allocated */
1870 }
1871
1872 static int
1873 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1874 {
1875 int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1876 int sg_tablesize = sfp->parentdp->sg_tablesize;
1877 int blk_size = buff_size, order;
1878 gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
1879 struct sg_device *sdp = sfp->parentdp;
1880
1881 if (blk_size < 0)
1882 return -EFAULT;
1883 if (0 == blk_size)
1884 ++blk_size; /* don't know why */
1885 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1886 blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1887 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1888 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1889 buff_size, blk_size));
1890
1891 /* N.B. ret_sz carried into this block ... */
1892 mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1893 if (mx_sc_elems < 0)
1894 return mx_sc_elems; /* most likely -ENOMEM */
1895
1896 num = scatter_elem_sz;
1897 if (unlikely(num != scatter_elem_sz_prev)) {
1898 if (num < PAGE_SIZE) {
1899 scatter_elem_sz = PAGE_SIZE;
1900 scatter_elem_sz_prev = PAGE_SIZE;
1901 } else
1902 scatter_elem_sz_prev = num;
1903 }
1904
1905 if (sdp->device->host->unchecked_isa_dma)
1906 gfp_mask |= GFP_DMA;
1907
1908 order = get_order(num);
1909 retry:
1910 ret_sz = 1 << (PAGE_SHIFT + order);
1911
1912 for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1913 k++, rem_sz -= ret_sz) {
1914
1915 num = (rem_sz > scatter_elem_sz_prev) ?
1916 scatter_elem_sz_prev : rem_sz;
1917
1918 schp->pages[k] = alloc_pages(gfp_mask, order);
1919 if (!schp->pages[k])
1920 goto out;
1921
1922 if (num == scatter_elem_sz_prev) {
1923 if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1924 scatter_elem_sz = ret_sz;
1925 scatter_elem_sz_prev = ret_sz;
1926 }
1927 }
1928
1929 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1930 "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1931 k, num, ret_sz));
1932 } /* end of for loop */
1933
1934 schp->page_order = order;
1935 schp->k_use_sg = k;
1936 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1937 "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1938 k, rem_sz));
1939
1940 schp->bufflen = blk_size;
1941 if (rem_sz > 0) /* must have failed */
1942 return -ENOMEM;
1943 return 0;
1944 out:
1945 for (i = 0; i < k; i++)
1946 __free_pages(schp->pages[i], order);
1947
1948 if (--order >= 0)
1949 goto retry;
1950
1951 return -ENOMEM;
1952 }
1953
1954 static void
1955 sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1956 {
1957 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1958 "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1959 if (schp->pages && schp->sglist_len > 0) {
1960 if (!schp->dio_in_use) {
1961 int k;
1962
1963 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1964 SCSI_LOG_TIMEOUT(5,
1965 sg_printk(KERN_INFO, sfp->parentdp,
1966 "sg_remove_scat: k=%d, pg=0x%p\n",
1967 k, schp->pages[k]));
1968 __free_pages(schp->pages[k], schp->page_order);
1969 }
1970
1971 kfree(schp->pages);
1972 }
1973 }
1974 memset(schp, 0, sizeof (*schp));
1975 }
1976
1977 static int
1978 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1979 {
1980 Sg_scatter_hold *schp = &srp->data;
1981 int k, num;
1982
1983 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1984 "sg_read_oxfer: num_read_xfer=%d\n",
1985 num_read_xfer));
1986 if ((!outp) || (num_read_xfer <= 0))
1987 return 0;
1988
1989 num = 1 << (PAGE_SHIFT + schp->page_order);
1990 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1991 if (num > num_read_xfer) {
1992 if (__copy_to_user(outp, page_address(schp->pages[k]),
1993 num_read_xfer))
1994 return -EFAULT;
1995 break;
1996 } else {
1997 if (__copy_to_user(outp, page_address(schp->pages[k]),
1998 num))
1999 return -EFAULT;
2000 num_read_xfer -= num;
2001 if (num_read_xfer <= 0)
2002 break;
2003 outp += num;
2004 }
2005 }
2006
2007 return 0;
2008 }
2009
2010 static void
2011 sg_build_reserve(Sg_fd * sfp, int req_size)
2012 {
2013 Sg_scatter_hold *schp = &sfp->reserve;
2014
2015 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2016 "sg_build_reserve: req_size=%d\n", req_size));
2017 do {
2018 if (req_size < PAGE_SIZE)
2019 req_size = PAGE_SIZE;
2020 if (0 == sg_build_indirect(schp, sfp, req_size))
2021 return;
2022 else
2023 sg_remove_scat(sfp, schp);
2024 req_size >>= 1; /* divide by 2 */
2025 } while (req_size > (PAGE_SIZE / 2));
2026 }
2027
2028 static void
2029 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2030 {
2031 Sg_scatter_hold *req_schp = &srp->data;
2032 Sg_scatter_hold *rsv_schp = &sfp->reserve;
2033 int k, num, rem;
2034
2035 srp->res_used = 1;
2036 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2037 "sg_link_reserve: size=%d\n", size));
2038 rem = size;
2039
2040 num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
2041 for (k = 0; k < rsv_schp->k_use_sg; k++) {
2042 if (rem <= num) {
2043 req_schp->k_use_sg = k + 1;
2044 req_schp->sglist_len = rsv_schp->sglist_len;
2045 req_schp->pages = rsv_schp->pages;
2046
2047 req_schp->bufflen = size;
2048 req_schp->page_order = rsv_schp->page_order;
2049 break;
2050 } else
2051 rem -= num;
2052 }
2053
2054 if (k >= rsv_schp->k_use_sg)
2055 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2056 "sg_link_reserve: BAD size\n"));
2057 }
2058
2059 static void
2060 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2061 {
2062 Sg_scatter_hold *req_schp = &srp->data;
2063
2064 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2065 "sg_unlink_reserve: req->k_use_sg=%d\n",
2066 (int) req_schp->k_use_sg));
2067 req_schp->k_use_sg = 0;
2068 req_schp->bufflen = 0;
2069 req_schp->pages = NULL;
2070 req_schp->page_order = 0;
2071 req_schp->sglist_len = 0;
2072 srp->res_used = 0;
2073 /* Called without mutex lock to avoid deadlock */
2074 sfp->res_in_use = 0;
2075 }
2076
2077 static Sg_request *
2078 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2079 {
2080 Sg_request *resp;
2081 unsigned long iflags;
2082
2083 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2084 list_for_each_entry(resp, &sfp->rq_list, entry) {
2085 /* look for requests that are ready + not SG_IO owned */
2086 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2087 ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2088 resp->done = 2; /* guard against other readers */
2089 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2090 return resp;
2091 }
2092 }
2093 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2094 return NULL;
2095 }
2096
2097 /* always adds to end of list */
2098 static Sg_request *
2099 sg_add_request(Sg_fd * sfp)
2100 {
2101 int k;
2102 unsigned long iflags;
2103 Sg_request *rp = sfp->req_arr;
2104
2105 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2106 if (!list_empty(&sfp->rq_list)) {
2107 if (!sfp->cmd_q)
2108 goto out_unlock;
2109
2110 for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2111 if (!rp->parentfp)
2112 break;
2113 }
2114 if (k >= SG_MAX_QUEUE)
2115 goto out_unlock;
2116 }
2117 memset(rp, 0, sizeof (Sg_request));
2118 rp->parentfp = sfp;
2119 rp->header.duration = jiffies_to_msecs(jiffies);
2120 list_add_tail(&rp->entry, &sfp->rq_list);
2121 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2122 return rp;
2123 out_unlock:
2124 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2125 return NULL;
2126 }
2127
2128 /* Return of 1 for found; 0 for not found */
2129 static int
2130 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2131 {
2132 unsigned long iflags;
2133 int res = 0;
2134
2135 if (!sfp || !srp || list_empty(&sfp->rq_list))
2136 return res;
2137 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2138 if (!list_empty(&srp->entry)) {
2139 list_del(&srp->entry);
2140 srp->parentfp = NULL;
2141 res = 1;
2142 }
2143 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2144 return res;
2145 }
2146
2147 static Sg_fd *
2148 sg_add_sfp(Sg_device * sdp)
2149 {
2150 Sg_fd *sfp;
2151 unsigned long iflags;
2152 int bufflen;
2153
2154 sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2155 if (!sfp)
2156 return ERR_PTR(-ENOMEM);
2157
2158 init_waitqueue_head(&sfp->read_wait);
2159 rwlock_init(&sfp->rq_list_lock);
2160 INIT_LIST_HEAD(&sfp->rq_list);
2161 kref_init(&sfp->f_ref);
2162 mutex_init(&sfp->f_mutex);
2163 sfp->timeout = SG_DEFAULT_TIMEOUT;
2164 sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2165 sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2166 sfp->cmd_q = SG_DEF_COMMAND_Q;
2167 sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2168 sfp->parentdp = sdp;
2169 write_lock_irqsave(&sdp->sfd_lock, iflags);
2170 if (atomic_read(&sdp->detaching)) {
2171 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2172 kfree(sfp);
2173 return ERR_PTR(-ENODEV);
2174 }
2175 list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2176 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2177 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2178 "sg_add_sfp: sfp=0x%p\n", sfp));
2179 if (unlikely(sg_big_buff != def_reserved_size))
2180 sg_big_buff = def_reserved_size;
2181
2182 bufflen = min_t(int, sg_big_buff,
2183 max_sectors_bytes(sdp->device->request_queue));
2184 sg_build_reserve(sfp, bufflen);
2185 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2186 "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2187 sfp->reserve.bufflen,
2188 sfp->reserve.k_use_sg));
2189
2190 kref_get(&sdp->d_ref);
2191 __module_get(THIS_MODULE);
2192 return sfp;
2193 }
2194
2195 static void
2196 sg_remove_sfp_usercontext(struct work_struct *work)
2197 {
2198 struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2199 struct sg_device *sdp = sfp->parentdp;
2200 Sg_request *srp;
2201 unsigned long iflags;
2202
2203 /* Cleanup any responses which were never read(). */
2204 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2205 while (!list_empty(&sfp->rq_list)) {
2206 srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2207 sg_finish_rem_req(srp);
2208 list_del(&srp->entry);
2209 srp->parentfp = NULL;
2210 }
2211 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2212
2213 if (sfp->reserve.bufflen > 0) {
2214 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2215 "sg_remove_sfp: bufflen=%d, k_use_sg=%d\n",
2216 (int) sfp->reserve.bufflen,
2217 (int) sfp->reserve.k_use_sg));
2218 sg_remove_scat(sfp, &sfp->reserve);
2219 }
2220
2221 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2222 "sg_remove_sfp: sfp=0x%p\n", sfp));
2223 kfree(sfp);
2224
2225 scsi_device_put(sdp->device);
2226 kref_put(&sdp->d_ref, sg_device_destroy);
2227 module_put(THIS_MODULE);
2228 }
2229
2230 static void
2231 sg_remove_sfp(struct kref *kref)
2232 {
2233 struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2234 struct sg_device *sdp = sfp->parentdp;
2235 unsigned long iflags;
2236
2237 write_lock_irqsave(&sdp->sfd_lock, iflags);
2238 list_del(&sfp->sfd_siblings);
2239 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2240
2241 INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2242 schedule_work(&sfp->ew.work);
2243 }
2244
2245 #ifdef CONFIG_SCSI_PROC_FS
2246 static int
2247 sg_idr_max_id(int id, void *p, void *data)
2248 {
2249 int *k = data;
2250
2251 if (*k < id)
2252 *k = id;
2253
2254 return 0;
2255 }
2256
2257 static int
2258 sg_last_dev(void)
2259 {
2260 int k = -1;
2261 unsigned long iflags;
2262
2263 read_lock_irqsave(&sg_index_lock, iflags);
2264 idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2265 read_unlock_irqrestore(&sg_index_lock, iflags);
2266 return k + 1; /* origin 1 */
2267 }
2268 #endif
2269
2270 /* must be called with sg_index_lock held */
2271 static Sg_device *sg_lookup_dev(int dev)
2272 {
2273 return idr_find(&sg_index_idr, dev);
2274 }
2275
2276 static Sg_device *
2277 sg_get_dev(int dev)
2278 {
2279 struct sg_device *sdp;
2280 unsigned long flags;
2281
2282 read_lock_irqsave(&sg_index_lock, flags);
2283 sdp = sg_lookup_dev(dev);
2284 if (!sdp)
2285 sdp = ERR_PTR(-ENXIO);
2286 else if (atomic_read(&sdp->detaching)) {
2287 /* If sdp->detaching, then the refcount may already be 0, in
2288 * which case it would be a bug to do kref_get().
2289 */
2290 sdp = ERR_PTR(-ENODEV);
2291 } else
2292 kref_get(&sdp->d_ref);
2293 read_unlock_irqrestore(&sg_index_lock, flags);
2294
2295 return sdp;
2296 }
2297
2298 #ifdef CONFIG_SCSI_PROC_FS
2299 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2300
2301 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2302 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2303 size_t count, loff_t *off);
2304 static const struct file_operations adio_fops = {
2305 .owner = THIS_MODULE,
2306 .open = sg_proc_single_open_adio,
2307 .read = seq_read,
2308 .llseek = seq_lseek,
2309 .write = sg_proc_write_adio,
2310 .release = single_release,
2311 };
2312
2313 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2314 static ssize_t sg_proc_write_dressz(struct file *filp,
2315 const char __user *buffer, size_t count, loff_t *off);
2316 static const struct file_operations dressz_fops = {
2317 .owner = THIS_MODULE,
2318 .open = sg_proc_single_open_dressz,
2319 .read = seq_read,
2320 .llseek = seq_lseek,
2321 .write = sg_proc_write_dressz,
2322 .release = single_release,
2323 };
2324
2325 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2326 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2327 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2328 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2329 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2330 static void dev_seq_stop(struct seq_file *s, void *v);
2331 static const struct seq_operations dev_seq_ops = {
2332 .start = dev_seq_start,
2333 .next = dev_seq_next,
2334 .stop = dev_seq_stop,
2335 .show = sg_proc_seq_show_dev,
2336 };
2337
2338 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2339 static const struct seq_operations devstrs_seq_ops = {
2340 .start = dev_seq_start,
2341 .next = dev_seq_next,
2342 .stop = dev_seq_stop,
2343 .show = sg_proc_seq_show_devstrs,
2344 };
2345
2346 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2347 static const struct seq_operations debug_seq_ops = {
2348 .start = dev_seq_start,
2349 .next = dev_seq_next,
2350 .stop = dev_seq_stop,
2351 .show = sg_proc_seq_show_debug,
2352 };
2353
2354 static int
2355 sg_proc_init(void)
2356 {
2357 struct proc_dir_entry *p;
2358
2359 p = proc_mkdir("scsi/sg", NULL);
2360 if (!p)
2361 return 1;
2362
2363 proc_create("allow_dio", S_IRUGO | S_IWUSR, p, &adio_fops);
2364 proc_create_seq("debug", S_IRUGO, p, &debug_seq_ops);
2365 proc_create("def_reserved_size", S_IRUGO | S_IWUSR, p, &dressz_fops);
2366 proc_create_single("device_hdr", S_IRUGO, p, sg_proc_seq_show_devhdr);
2367 proc_create_seq("devices", S_IRUGO, p, &dev_seq_ops);
2368 proc_create_seq("device_strs", S_IRUGO, p, &devstrs_seq_ops);
2369 proc_create_single("version", S_IRUGO, p, sg_proc_seq_show_version);
2370 return 0;
2371 }
2372
2373
2374 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2375 {
2376 seq_printf(s, "%d\n", *((int *)s->private));
2377 return 0;
2378 }
2379
2380 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2381 {
2382 return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2383 }
2384
2385 static ssize_t
2386 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2387 size_t count, loff_t *off)
2388 {
2389 int err;
2390 unsigned long num;
2391
2392 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2393 return -EACCES;
2394 err = kstrtoul_from_user(buffer, count, 0, &num);
2395 if (err)
2396 return err;
2397 sg_allow_dio = num ? 1 : 0;
2398 return count;
2399 }
2400
2401 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2402 {
2403 return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2404 }
2405
2406 static ssize_t
2407 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2408 size_t count, loff_t *off)
2409 {
2410 int err;
2411 unsigned long k = ULONG_MAX;
2412
2413 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2414 return -EACCES;
2415
2416 err = kstrtoul_from_user(buffer, count, 0, &k);
2417 if (err)
2418 return err;
2419 if (k <= 1048576) { /* limit "big buff" to 1 MB */
2420 sg_big_buff = k;
2421 return count;
2422 }
2423 return -ERANGE;
2424 }
2425
2426 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2427 {
2428 seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2429 sg_version_date);
2430 return 0;
2431 }
2432
2433 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2434 {
2435 seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2436 return 0;
2437 }
2438
2439 struct sg_proc_deviter {
2440 loff_t index;
2441 size_t max;
2442 };
2443
2444 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2445 {
2446 struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2447
2448 s->private = it;
2449 if (! it)
2450 return NULL;
2451
2452 it->index = *pos;
2453 it->max = sg_last_dev();
2454 if (it->index >= it->max)
2455 return NULL;
2456 return it;
2457 }
2458
2459 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2460 {
2461 struct sg_proc_deviter * it = s->private;
2462
2463 *pos = ++it->index;
2464 return (it->index < it->max) ? it : NULL;
2465 }
2466
2467 static void dev_seq_stop(struct seq_file *s, void *v)
2468 {
2469 kfree(s->private);
2470 }
2471
2472 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2473 {
2474 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2475 Sg_device *sdp;
2476 struct scsi_device *scsidp;
2477 unsigned long iflags;
2478
2479 read_lock_irqsave(&sg_index_lock, iflags);
2480 sdp = it ? sg_lookup_dev(it->index) : NULL;
2481 if ((NULL == sdp) || (NULL == sdp->device) ||
2482 (atomic_read(&sdp->detaching)))
2483 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2484 else {
2485 scsidp = sdp->device;
2486 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2487 scsidp->host->host_no, scsidp->channel,
2488 scsidp->id, scsidp->lun, (int) scsidp->type,
2489 1,
2490 (int) scsidp->queue_depth,
2491 (int) atomic_read(&scsidp->device_busy),
2492 (int) scsi_device_online(scsidp));
2493 }
2494 read_unlock_irqrestore(&sg_index_lock, iflags);
2495 return 0;
2496 }
2497
2498 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2499 {
2500 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2501 Sg_device *sdp;
2502 struct scsi_device *scsidp;
2503 unsigned long iflags;
2504
2505 read_lock_irqsave(&sg_index_lock, iflags);
2506 sdp = it ? sg_lookup_dev(it->index) : NULL;
2507 scsidp = sdp ? sdp->device : NULL;
2508 if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2509 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2510 scsidp->vendor, scsidp->model, scsidp->rev);
2511 else
2512 seq_puts(s, "<no active device>\n");
2513 read_unlock_irqrestore(&sg_index_lock, iflags);
2514 return 0;
2515 }
2516
2517 /* must be called while holding sg_index_lock */
2518 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2519 {
2520 int k, new_interface, blen, usg;
2521 Sg_request *srp;
2522 Sg_fd *fp;
2523 const sg_io_hdr_t *hp;
2524 const char * cp;
2525 unsigned int ms;
2526
2527 k = 0;
2528 list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2529 k++;
2530 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2531 seq_printf(s, " FD(%d): timeout=%dms bufflen=%d "
2532 "(res)sgat=%d low_dma=%d\n", k,
2533 jiffies_to_msecs(fp->timeout),
2534 fp->reserve.bufflen,
2535 (int) fp->reserve.k_use_sg,
2536 (int) sdp->device->host->unchecked_isa_dma);
2537 seq_printf(s, " cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2538 (int) fp->cmd_q, (int) fp->force_packid,
2539 (int) fp->keep_orphan);
2540 list_for_each_entry(srp, &fp->rq_list, entry) {
2541 hp = &srp->header;
2542 new_interface = (hp->interface_id == '\0') ? 0 : 1;
2543 if (srp->res_used) {
2544 if (new_interface &&
2545 (SG_FLAG_MMAP_IO & hp->flags))
2546 cp = " mmap>> ";
2547 else
2548 cp = " rb>> ";
2549 } else {
2550 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2551 cp = " dio>> ";
2552 else
2553 cp = " ";
2554 }
2555 seq_puts(s, cp);
2556 blen = srp->data.bufflen;
2557 usg = srp->data.k_use_sg;
2558 seq_puts(s, srp->done ?
2559 ((1 == srp->done) ? "rcv:" : "fin:")
2560 : "act:");
2561 seq_printf(s, " id=%d blen=%d",
2562 srp->header.pack_id, blen);
2563 if (srp->done)
2564 seq_printf(s, " dur=%d", hp->duration);
2565 else {
2566 ms = jiffies_to_msecs(jiffies);
2567 seq_printf(s, " t_o/elap=%d/%d",
2568 (new_interface ? hp->timeout :
2569 jiffies_to_msecs(fp->timeout)),
2570 (ms > hp->duration ? ms - hp->duration : 0));
2571 }
2572 seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2573 (int) srp->data.cmd_opcode);
2574 }
2575 if (list_empty(&fp->rq_list))
2576 seq_puts(s, " No requests active\n");
2577 read_unlock(&fp->rq_list_lock);
2578 }
2579 }
2580
2581 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2582 {
2583 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2584 Sg_device *sdp;
2585 unsigned long iflags;
2586
2587 if (it && (0 == it->index))
2588 seq_printf(s, "max_active_device=%d def_reserved_size=%d\n",
2589 (int)it->max, sg_big_buff);
2590
2591 read_lock_irqsave(&sg_index_lock, iflags);
2592 sdp = it ? sg_lookup_dev(it->index) : NULL;
2593 if (NULL == sdp)
2594 goto skip;
2595 read_lock(&sdp->sfd_lock);
2596 if (!list_empty(&sdp->sfds)) {
2597 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2598 if (atomic_read(&sdp->detaching))
2599 seq_puts(s, "detaching pending close ");
2600 else if (sdp->device) {
2601 struct scsi_device *scsidp = sdp->device;
2602
2603 seq_printf(s, "%d:%d:%d:%llu em=%d",
2604 scsidp->host->host_no,
2605 scsidp->channel, scsidp->id,
2606 scsidp->lun,
2607 scsidp->host->hostt->emulated);
2608 }
2609 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2610 sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2611 sg_proc_debug_helper(s, sdp);
2612 }
2613 read_unlock(&sdp->sfd_lock);
2614 skip:
2615 read_unlock_irqrestore(&sg_index_lock, iflags);
2616 return 0;
2617 }
2618
2619 #endif /* CONFIG_SCSI_PROC_FS */
2620
2621 module_init(init_sg);
2622 module_exit(exit_sg);
Linux with added FPC-III support