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Merge branch 'nvme-5.7' of git://git.infradead.org/nvme into block-5.7
[thirdparty/linux.git] / drivers / scsi / sg.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * History:
4 * Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
5 * to allow user process control of SCSI devices.
6 * Development Sponsored by Killy Corp. NY NY
7 *
8 * Original driver (sg.c):
9 * Copyright (C) 1992 Lawrence Foard
10 * Version 2 and 3 extensions to driver:
11 * Copyright (C) 1998 - 2014 Douglas Gilbert
12 */
13
14 static 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>
62 static char *sg_version_date = "20140603";
63
64 static 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
79 int 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).] */
86 static int def_reserved_size = -1; /* picks up init parameter */
87 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
88
89 static int scatter_elem_sz = SG_SCATTER_SZ;
90 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
91
92 #define SG_SECTOR_SZ 512
93
94 static int sg_add_device(struct device *, struct class_interface *);
95 static void sg_remove_device(struct device *, struct class_interface *);
96
97 static DEFINE_IDR(sg_index_idr);
98 static DEFINE_RWLOCK(sg_index_lock); /* Also used to lock
99 file descriptor list for device */
100
101 static struct class_interface sg_interface = {
102 .add_dev = sg_add_device,
103 .remove_dev = sg_remove_device,
104 };
105
106 typedef 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
116 struct sg_device; /* forward declarations */
117 struct sg_fd;
118
119 typedef 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
135 typedef 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
157 typedef 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 */
175 static void sg_rq_end_io(struct request *rq, blk_status_t status);
176 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
177 static int sg_finish_rem_req(Sg_request * srp);
178 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
179 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
180 Sg_request * srp);
181 static 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);
184 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
185 unsigned char *cmnd, int timeout, int blocking);
186 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
187 static void sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp);
188 static void sg_build_reserve(Sg_fd * sfp, int req_size);
189 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
190 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
191 static Sg_fd *sg_add_sfp(Sg_device * sdp);
192 static void sg_remove_sfp(struct kref *);
193 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
194 static Sg_request *sg_add_request(Sg_fd * sfp);
195 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
196 static Sg_device *sg_get_dev(int dev);
197 static 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 */
220 static 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
235 static 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
245 static int
246 open_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 */
282 static int
283 sg_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;
361 sg_put:
362 kref_put(&sdp->d_ref, sg_device_destroy);
363 return retval;
364
365 out_undo:
366 if (flags & O_EXCL) {
367 sdp->exclude = false; /* undo if error */
368 wake_up_interruptible(&sdp->open_wait);
369 }
370 error_mutex_locked:
371 mutex_unlock(&sdp->open_rel_lock);
372 error_out:
373 scsi_autopm_put_device(sdp->device);
374 sdp_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 */
381 static int
382 sg_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
408 static 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
440 static ssize_t
441 sg_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;
553 free_old_hdr:
554 kfree(old_hdr);
555 return retval;
556 }
557
558 static ssize_t
559 sg_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);
592 err_out:
593 err2 = sg_finish_rem_req(srp);
594 sg_remove_request(sfp, srp);
595 return err ? : err2 ? : count;
596 }
597
598 static ssize_t
599 sg_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 return -EFAULT;
690 /*
691 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
692 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
693 * is a non-zero input_size, so emit a warning.
694 */
695 if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
696 printk_ratelimited(KERN_WARNING
697 "sg_write: data in/out %d/%d bytes "
698 "for SCSI command 0x%x-- guessing "
699 "data in;\n program %s not setting "
700 "count and/or reply_len properly\n",
701 old_hdr.reply_len - (int)SZ_SG_HEADER,
702 input_size, (unsigned int) cmnd[0],
703 current->comm);
704 }
705 k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
706 return (k < 0) ? k : count;
707 }
708
709 static ssize_t
710 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
711 size_t count, int blocking, int read_only, int sg_io_owned,
712 Sg_request **o_srp)
713 {
714 int k;
715 Sg_request *srp;
716 sg_io_hdr_t *hp;
717 unsigned char cmnd[SG_MAX_CDB_SIZE];
718 int timeout;
719 unsigned long ul_timeout;
720
721 if (count < SZ_SG_IO_HDR)
722 return -EINVAL;
723
724 sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
725 if (!(srp = sg_add_request(sfp))) {
726 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
727 "sg_new_write: queue full\n"));
728 return -EDOM;
729 }
730 srp->sg_io_owned = sg_io_owned;
731 hp = &srp->header;
732 if (get_sg_io_hdr(hp, buf)) {
733 sg_remove_request(sfp, srp);
734 return -EFAULT;
735 }
736 if (hp->interface_id != 'S') {
737 sg_remove_request(sfp, srp);
738 return -ENOSYS;
739 }
740 if (hp->flags & SG_FLAG_MMAP_IO) {
741 if (hp->dxfer_len > sfp->reserve.bufflen) {
742 sg_remove_request(sfp, srp);
743 return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
744 }
745 if (hp->flags & SG_FLAG_DIRECT_IO) {
746 sg_remove_request(sfp, srp);
747 return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
748 }
749 if (sfp->res_in_use) {
750 sg_remove_request(sfp, srp);
751 return -EBUSY; /* reserve buffer already being used */
752 }
753 }
754 ul_timeout = msecs_to_jiffies(srp->header.timeout);
755 timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
756 if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
757 sg_remove_request(sfp, srp);
758 return -EMSGSIZE;
759 }
760 if (copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
761 sg_remove_request(sfp, srp);
762 return -EFAULT;
763 }
764 if (read_only && sg_allow_access(file, cmnd)) {
765 sg_remove_request(sfp, srp);
766 return -EPERM;
767 }
768 k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
769 if (k < 0)
770 return k;
771 if (o_srp)
772 *o_srp = srp;
773 return count;
774 }
775
776 static int
777 sg_common_write(Sg_fd * sfp, Sg_request * srp,
778 unsigned char *cmnd, int timeout, int blocking)
779 {
780 int k, at_head;
781 Sg_device *sdp = sfp->parentdp;
782 sg_io_hdr_t *hp = &srp->header;
783
784 srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
785 hp->status = 0;
786 hp->masked_status = 0;
787 hp->msg_status = 0;
788 hp->info = 0;
789 hp->host_status = 0;
790 hp->driver_status = 0;
791 hp->resid = 0;
792 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
793 "sg_common_write: scsi opcode=0x%02x, cmd_size=%d\n",
794 (int) cmnd[0], (int) hp->cmd_len));
795
796 if (hp->dxfer_len >= SZ_256M)
797 return -EINVAL;
798
799 k = sg_start_req(srp, cmnd);
800 if (k) {
801 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
802 "sg_common_write: start_req err=%d\n", k));
803 sg_finish_rem_req(srp);
804 sg_remove_request(sfp, srp);
805 return k; /* probably out of space --> ENOMEM */
806 }
807 if (atomic_read(&sdp->detaching)) {
808 if (srp->bio) {
809 scsi_req_free_cmd(scsi_req(srp->rq));
810 blk_put_request(srp->rq);
811 srp->rq = NULL;
812 }
813
814 sg_finish_rem_req(srp);
815 sg_remove_request(sfp, srp);
816 return -ENODEV;
817 }
818
819 hp->duration = jiffies_to_msecs(jiffies);
820 if (hp->interface_id != '\0' && /* v3 (or later) interface */
821 (SG_FLAG_Q_AT_TAIL & hp->flags))
822 at_head = 0;
823 else
824 at_head = 1;
825
826 srp->rq->timeout = timeout;
827 kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
828 blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
829 srp->rq, at_head, sg_rq_end_io);
830 return 0;
831 }
832
833 static int srp_done(Sg_fd *sfp, Sg_request *srp)
834 {
835 unsigned long flags;
836 int ret;
837
838 read_lock_irqsave(&sfp->rq_list_lock, flags);
839 ret = srp->done;
840 read_unlock_irqrestore(&sfp->rq_list_lock, flags);
841 return ret;
842 }
843
844 static int max_sectors_bytes(struct request_queue *q)
845 {
846 unsigned int max_sectors = queue_max_sectors(q);
847
848 max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
849
850 return max_sectors << 9;
851 }
852
853 static void
854 sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
855 {
856 Sg_request *srp;
857 int val;
858 unsigned int ms;
859
860 val = 0;
861 list_for_each_entry(srp, &sfp->rq_list, entry) {
862 if (val >= SG_MAX_QUEUE)
863 break;
864 rinfo[val].req_state = srp->done + 1;
865 rinfo[val].problem =
866 srp->header.masked_status &
867 srp->header.host_status &
868 srp->header.driver_status;
869 if (srp->done)
870 rinfo[val].duration =
871 srp->header.duration;
872 else {
873 ms = jiffies_to_msecs(jiffies);
874 rinfo[val].duration =
875 (ms > srp->header.duration) ?
876 (ms - srp->header.duration) : 0;
877 }
878 rinfo[val].orphan = srp->orphan;
879 rinfo[val].sg_io_owned = srp->sg_io_owned;
880 rinfo[val].pack_id = srp->header.pack_id;
881 rinfo[val].usr_ptr = srp->header.usr_ptr;
882 val++;
883 }
884 }
885
886 #ifdef CONFIG_COMPAT
887 struct compat_sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
888 char req_state;
889 char orphan;
890 char sg_io_owned;
891 char problem;
892 int pack_id;
893 compat_uptr_t usr_ptr;
894 unsigned int duration;
895 int unused;
896 };
897
898 static int put_compat_request_table(struct compat_sg_req_info __user *o,
899 struct sg_req_info *rinfo)
900 {
901 int i;
902 for (i = 0; i < SG_MAX_QUEUE; i++) {
903 if (copy_to_user(o + i, rinfo + i, offsetof(sg_req_info_t, usr_ptr)) ||
904 put_user((uintptr_t)rinfo[i].usr_ptr, &o[i].usr_ptr) ||
905 put_user(rinfo[i].duration, &o[i].duration) ||
906 put_user(rinfo[i].unused, &o[i].unused))
907 return -EFAULT;
908 }
909 return 0;
910 }
911 #endif
912
913 static long
914 sg_ioctl_common(struct file *filp, Sg_device *sdp, Sg_fd *sfp,
915 unsigned int cmd_in, void __user *p)
916 {
917 int __user *ip = p;
918 int result, val, read_only;
919 Sg_request *srp;
920 unsigned long iflags;
921
922 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
923 "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
924 read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
925
926 switch (cmd_in) {
927 case SG_IO:
928 if (atomic_read(&sdp->detaching))
929 return -ENODEV;
930 if (!scsi_block_when_processing_errors(sdp->device))
931 return -ENXIO;
932 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
933 1, read_only, 1, &srp);
934 if (result < 0)
935 return result;
936 result = wait_event_interruptible(sfp->read_wait,
937 (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
938 if (atomic_read(&sdp->detaching))
939 return -ENODEV;
940 write_lock_irq(&sfp->rq_list_lock);
941 if (srp->done) {
942 srp->done = 2;
943 write_unlock_irq(&sfp->rq_list_lock);
944 result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
945 return (result < 0) ? result : 0;
946 }
947 srp->orphan = 1;
948 write_unlock_irq(&sfp->rq_list_lock);
949 return result; /* -ERESTARTSYS because signal hit process */
950 case SG_SET_TIMEOUT:
951 result = get_user(val, ip);
952 if (result)
953 return result;
954 if (val < 0)
955 return -EIO;
956 if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
957 val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
958 INT_MAX);
959 sfp->timeout_user = val;
960 sfp->timeout = mult_frac(val, HZ, USER_HZ);
961
962 return 0;
963 case SG_GET_TIMEOUT: /* N.B. User receives timeout as return value */
964 /* strange ..., for backward compatibility */
965 return sfp->timeout_user;
966 case SG_SET_FORCE_LOW_DMA:
967 /*
968 * N.B. This ioctl never worked properly, but failed to
969 * return an error value. So returning '0' to keep compability
970 * with legacy applications.
971 */
972 return 0;
973 case SG_GET_LOW_DMA:
974 return put_user((int) sdp->device->host->unchecked_isa_dma, ip);
975 case SG_GET_SCSI_ID:
976 {
977 sg_scsi_id_t v;
978
979 if (atomic_read(&sdp->detaching))
980 return -ENODEV;
981 memset(&v, 0, sizeof(v));
982 v.host_no = sdp->device->host->host_no;
983 v.channel = sdp->device->channel;
984 v.scsi_id = sdp->device->id;
985 v.lun = sdp->device->lun;
986 v.scsi_type = sdp->device->type;
987 v.h_cmd_per_lun = sdp->device->host->cmd_per_lun;
988 v.d_queue_depth = sdp->device->queue_depth;
989 if (copy_to_user(p, &v, sizeof(sg_scsi_id_t)))
990 return -EFAULT;
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 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1001 list_for_each_entry(srp, &sfp->rq_list, entry) {
1002 if ((1 == srp->done) && (!srp->sg_io_owned)) {
1003 read_unlock_irqrestore(&sfp->rq_list_lock,
1004 iflags);
1005 return put_user(srp->header.pack_id, ip);
1006 }
1007 }
1008 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1009 return put_user(-1, ip);
1010 case SG_GET_NUM_WAITING:
1011 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1012 val = 0;
1013 list_for_each_entry(srp, &sfp->rq_list, entry) {
1014 if ((1 == srp->done) && (!srp->sg_io_owned))
1015 ++val;
1016 }
1017 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1018 return put_user(val, ip);
1019 case SG_GET_SG_TABLESIZE:
1020 return put_user(sdp->sg_tablesize, ip);
1021 case SG_SET_RESERVED_SIZE:
1022 result = get_user(val, ip);
1023 if (result)
1024 return result;
1025 if (val < 0)
1026 return -EINVAL;
1027 val = min_t(int, val,
1028 max_sectors_bytes(sdp->device->request_queue));
1029 mutex_lock(&sfp->f_mutex);
1030 if (val != sfp->reserve.bufflen) {
1031 if (sfp->mmap_called ||
1032 sfp->res_in_use) {
1033 mutex_unlock(&sfp->f_mutex);
1034 return -EBUSY;
1035 }
1036
1037 sg_remove_scat(sfp, &sfp->reserve);
1038 sg_build_reserve(sfp, val);
1039 }
1040 mutex_unlock(&sfp->f_mutex);
1041 return 0;
1042 case SG_GET_RESERVED_SIZE:
1043 val = min_t(int, sfp->reserve.bufflen,
1044 max_sectors_bytes(sdp->device->request_queue));
1045 return put_user(val, ip);
1046 case SG_SET_COMMAND_Q:
1047 result = get_user(val, ip);
1048 if (result)
1049 return result;
1050 sfp->cmd_q = val ? 1 : 0;
1051 return 0;
1052 case SG_GET_COMMAND_Q:
1053 return put_user((int) sfp->cmd_q, ip);
1054 case SG_SET_KEEP_ORPHAN:
1055 result = get_user(val, ip);
1056 if (result)
1057 return result;
1058 sfp->keep_orphan = val;
1059 return 0;
1060 case SG_GET_KEEP_ORPHAN:
1061 return put_user((int) sfp->keep_orphan, ip);
1062 case SG_NEXT_CMD_LEN:
1063 result = get_user(val, ip);
1064 if (result)
1065 return result;
1066 if (val > SG_MAX_CDB_SIZE)
1067 return -ENOMEM;
1068 sfp->next_cmd_len = (val > 0) ? val : 0;
1069 return 0;
1070 case SG_GET_VERSION_NUM:
1071 return put_user(sg_version_num, ip);
1072 case SG_GET_ACCESS_COUNT:
1073 /* faked - we don't have a real access count anymore */
1074 val = (sdp->device ? 1 : 0);
1075 return put_user(val, ip);
1076 case SG_GET_REQUEST_TABLE:
1077 {
1078 sg_req_info_t *rinfo;
1079
1080 rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
1081 GFP_KERNEL);
1082 if (!rinfo)
1083 return -ENOMEM;
1084 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1085 sg_fill_request_table(sfp, rinfo);
1086 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1087 #ifdef CONFIG_COMPAT
1088 if (in_compat_syscall())
1089 result = put_compat_request_table(p, rinfo);
1090 else
1091 #endif
1092 result = copy_to_user(p, rinfo,
1093 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1094 result = result ? -EFAULT : 0;
1095 kfree(rinfo);
1096 return result;
1097 }
1098 case SG_EMULATED_HOST:
1099 if (atomic_read(&sdp->detaching))
1100 return -ENODEV;
1101 return put_user(sdp->device->host->hostt->emulated, ip);
1102 case SCSI_IOCTL_SEND_COMMAND:
1103 if (atomic_read(&sdp->detaching))
1104 return -ENODEV;
1105 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1106 case SG_SET_DEBUG:
1107 result = get_user(val, ip);
1108 if (result)
1109 return result;
1110 sdp->sgdebug = (char) val;
1111 return 0;
1112 case BLKSECTGET:
1113 return put_user(max_sectors_bytes(sdp->device->request_queue),
1114 ip);
1115 case BLKTRACESETUP:
1116 return blk_trace_setup(sdp->device->request_queue,
1117 sdp->disk->disk_name,
1118 MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1119 NULL, p);
1120 case BLKTRACESTART:
1121 return blk_trace_startstop(sdp->device->request_queue, 1);
1122 case BLKTRACESTOP:
1123 return blk_trace_startstop(sdp->device->request_queue, 0);
1124 case BLKTRACETEARDOWN:
1125 return blk_trace_remove(sdp->device->request_queue);
1126 case SCSI_IOCTL_GET_IDLUN:
1127 case SCSI_IOCTL_GET_BUS_NUMBER:
1128 case SCSI_IOCTL_PROBE_HOST:
1129 case SG_GET_TRANSFORM:
1130 case SG_SCSI_RESET:
1131 if (atomic_read(&sdp->detaching))
1132 return -ENODEV;
1133 break;
1134 default:
1135 if (read_only)
1136 return -EPERM; /* don't know so take safe approach */
1137 break;
1138 }
1139
1140 result = scsi_ioctl_block_when_processing_errors(sdp->device,
1141 cmd_in, filp->f_flags & O_NDELAY);
1142 if (result)
1143 return result;
1144
1145 return -ENOIOCTLCMD;
1146 }
1147
1148 static long
1149 sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1150 {
1151 void __user *p = (void __user *)arg;
1152 Sg_device *sdp;
1153 Sg_fd *sfp;
1154 int ret;
1155
1156 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1157 return -ENXIO;
1158
1159 ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
1160 if (ret != -ENOIOCTLCMD)
1161 return ret;
1162
1163 return scsi_ioctl(sdp->device, cmd_in, p);
1164 }
1165
1166 #ifdef CONFIG_COMPAT
1167 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1168 {
1169 void __user *p = compat_ptr(arg);
1170 Sg_device *sdp;
1171 Sg_fd *sfp;
1172 int ret;
1173
1174 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1175 return -ENXIO;
1176
1177 ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
1178 if (ret != -ENOIOCTLCMD)
1179 return ret;
1180
1181 return scsi_compat_ioctl(sdp->device, cmd_in, p);
1182 }
1183 #endif
1184
1185 static __poll_t
1186 sg_poll(struct file *filp, poll_table * wait)
1187 {
1188 __poll_t res = 0;
1189 Sg_device *sdp;
1190 Sg_fd *sfp;
1191 Sg_request *srp;
1192 int count = 0;
1193 unsigned long iflags;
1194
1195 sfp = filp->private_data;
1196 if (!sfp)
1197 return EPOLLERR;
1198 sdp = sfp->parentdp;
1199 if (!sdp)
1200 return EPOLLERR;
1201 poll_wait(filp, &sfp->read_wait, wait);
1202 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1203 list_for_each_entry(srp, &sfp->rq_list, entry) {
1204 /* if any read waiting, flag it */
1205 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1206 res = EPOLLIN | EPOLLRDNORM;
1207 ++count;
1208 }
1209 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1210
1211 if (atomic_read(&sdp->detaching))
1212 res |= EPOLLHUP;
1213 else if (!sfp->cmd_q) {
1214 if (0 == count)
1215 res |= EPOLLOUT | EPOLLWRNORM;
1216 } else if (count < SG_MAX_QUEUE)
1217 res |= EPOLLOUT | EPOLLWRNORM;
1218 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1219 "sg_poll: res=0x%x\n", (__force u32) res));
1220 return res;
1221 }
1222
1223 static int
1224 sg_fasync(int fd, struct file *filp, int mode)
1225 {
1226 Sg_device *sdp;
1227 Sg_fd *sfp;
1228
1229 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1230 return -ENXIO;
1231 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1232 "sg_fasync: mode=%d\n", mode));
1233
1234 return fasync_helper(fd, filp, mode, &sfp->async_qp);
1235 }
1236
1237 static vm_fault_t
1238 sg_vma_fault(struct vm_fault *vmf)
1239 {
1240 struct vm_area_struct *vma = vmf->vma;
1241 Sg_fd *sfp;
1242 unsigned long offset, len, sa;
1243 Sg_scatter_hold *rsv_schp;
1244 int k, length;
1245
1246 if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1247 return VM_FAULT_SIGBUS;
1248 rsv_schp = &sfp->reserve;
1249 offset = vmf->pgoff << PAGE_SHIFT;
1250 if (offset >= rsv_schp->bufflen)
1251 return VM_FAULT_SIGBUS;
1252 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1253 "sg_vma_fault: offset=%lu, scatg=%d\n",
1254 offset, rsv_schp->k_use_sg));
1255 sa = vma->vm_start;
1256 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1257 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1258 len = vma->vm_end - sa;
1259 len = (len < length) ? len : length;
1260 if (offset < len) {
1261 struct page *page = nth_page(rsv_schp->pages[k],
1262 offset >> PAGE_SHIFT);
1263 get_page(page); /* increment page count */
1264 vmf->page = page;
1265 return 0; /* success */
1266 }
1267 sa += len;
1268 offset -= len;
1269 }
1270
1271 return VM_FAULT_SIGBUS;
1272 }
1273
1274 static const struct vm_operations_struct sg_mmap_vm_ops = {
1275 .fault = sg_vma_fault,
1276 };
1277
1278 static int
1279 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1280 {
1281 Sg_fd *sfp;
1282 unsigned long req_sz, len, sa;
1283 Sg_scatter_hold *rsv_schp;
1284 int k, length;
1285 int ret = 0;
1286
1287 if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1288 return -ENXIO;
1289 req_sz = vma->vm_end - vma->vm_start;
1290 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1291 "sg_mmap starting, vm_start=%p, len=%d\n",
1292 (void *) vma->vm_start, (int) req_sz));
1293 if (vma->vm_pgoff)
1294 return -EINVAL; /* want no offset */
1295 rsv_schp = &sfp->reserve;
1296 mutex_lock(&sfp->f_mutex);
1297 if (req_sz > rsv_schp->bufflen) {
1298 ret = -ENOMEM; /* cannot map more than reserved buffer */
1299 goto out;
1300 }
1301
1302 sa = vma->vm_start;
1303 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1304 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1305 len = vma->vm_end - sa;
1306 len = (len < length) ? len : length;
1307 sa += len;
1308 }
1309
1310 sfp->mmap_called = 1;
1311 vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
1312 vma->vm_private_data = sfp;
1313 vma->vm_ops = &sg_mmap_vm_ops;
1314 out:
1315 mutex_unlock(&sfp->f_mutex);
1316 return ret;
1317 }
1318
1319 static void
1320 sg_rq_end_io_usercontext(struct work_struct *work)
1321 {
1322 struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1323 struct sg_fd *sfp = srp->parentfp;
1324
1325 sg_finish_rem_req(srp);
1326 sg_remove_request(sfp, srp);
1327 kref_put(&sfp->f_ref, sg_remove_sfp);
1328 }
1329
1330 /*
1331 * This function is a "bottom half" handler that is called by the mid
1332 * level when a command is completed (or has failed).
1333 */
1334 static void
1335 sg_rq_end_io(struct request *rq, blk_status_t status)
1336 {
1337 struct sg_request *srp = rq->end_io_data;
1338 struct scsi_request *req = scsi_req(rq);
1339 Sg_device *sdp;
1340 Sg_fd *sfp;
1341 unsigned long iflags;
1342 unsigned int ms;
1343 char *sense;
1344 int result, resid, done = 1;
1345
1346 if (WARN_ON(srp->done != 0))
1347 return;
1348
1349 sfp = srp->parentfp;
1350 if (WARN_ON(sfp == NULL))
1351 return;
1352
1353 sdp = sfp->parentdp;
1354 if (unlikely(atomic_read(&sdp->detaching)))
1355 pr_info("%s: device detaching\n", __func__);
1356
1357 sense = req->sense;
1358 result = req->result;
1359 resid = req->resid_len;
1360
1361 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1362 "sg_cmd_done: pack_id=%d, res=0x%x\n",
1363 srp->header.pack_id, result));
1364 srp->header.resid = resid;
1365 ms = jiffies_to_msecs(jiffies);
1366 srp->header.duration = (ms > srp->header.duration) ?
1367 (ms - srp->header.duration) : 0;
1368 if (0 != result) {
1369 struct scsi_sense_hdr sshdr;
1370
1371 srp->header.status = 0xff & result;
1372 srp->header.masked_status = status_byte(result);
1373 srp->header.msg_status = msg_byte(result);
1374 srp->header.host_status = host_byte(result);
1375 srp->header.driver_status = driver_byte(result);
1376 if ((sdp->sgdebug > 0) &&
1377 ((CHECK_CONDITION == srp->header.masked_status) ||
1378 (COMMAND_TERMINATED == srp->header.masked_status)))
1379 __scsi_print_sense(sdp->device, __func__, sense,
1380 SCSI_SENSE_BUFFERSIZE);
1381
1382 /* Following if statement is a patch supplied by Eric Youngdale */
1383 if (driver_byte(result) != 0
1384 && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1385 && !scsi_sense_is_deferred(&sshdr)
1386 && sshdr.sense_key == UNIT_ATTENTION
1387 && sdp->device->removable) {
1388 /* Detected possible disc change. Set the bit - this */
1389 /* may be used if there are filesystems using this device */
1390 sdp->device->changed = 1;
1391 }
1392 }
1393
1394 if (req->sense_len)
1395 memcpy(srp->sense_b, req->sense, SCSI_SENSE_BUFFERSIZE);
1396
1397 /* Rely on write phase to clean out srp status values, so no "else" */
1398
1399 /*
1400 * Free the request as soon as it is complete so that its resources
1401 * can be reused without waiting for userspace to read() the
1402 * result. But keep the associated bio (if any) around until
1403 * blk_rq_unmap_user() can be called from user context.
1404 */
1405 srp->rq = NULL;
1406 scsi_req_free_cmd(scsi_req(rq));
1407 blk_put_request(rq);
1408
1409 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1410 if (unlikely(srp->orphan)) {
1411 if (sfp->keep_orphan)
1412 srp->sg_io_owned = 0;
1413 else
1414 done = 0;
1415 }
1416 srp->done = done;
1417 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1418
1419 if (likely(done)) {
1420 /* Now wake up any sg_read() that is waiting for this
1421 * packet.
1422 */
1423 wake_up_interruptible(&sfp->read_wait);
1424 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1425 kref_put(&sfp->f_ref, sg_remove_sfp);
1426 } else {
1427 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1428 schedule_work(&srp->ew.work);
1429 }
1430 }
1431
1432 static const struct file_operations sg_fops = {
1433 .owner = THIS_MODULE,
1434 .read = sg_read,
1435 .write = sg_write,
1436 .poll = sg_poll,
1437 .unlocked_ioctl = sg_ioctl,
1438 #ifdef CONFIG_COMPAT
1439 .compat_ioctl = sg_compat_ioctl,
1440 #endif
1441 .open = sg_open,
1442 .mmap = sg_mmap,
1443 .release = sg_release,
1444 .fasync = sg_fasync,
1445 .llseek = no_llseek,
1446 };
1447
1448 static struct class *sg_sysfs_class;
1449
1450 static int sg_sysfs_valid = 0;
1451
1452 static Sg_device *
1453 sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1454 {
1455 struct request_queue *q = scsidp->request_queue;
1456 Sg_device *sdp;
1457 unsigned long iflags;
1458 int error;
1459 u32 k;
1460
1461 sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1462 if (!sdp) {
1463 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1464 "failure\n", __func__);
1465 return ERR_PTR(-ENOMEM);
1466 }
1467
1468 idr_preload(GFP_KERNEL);
1469 write_lock_irqsave(&sg_index_lock, iflags);
1470
1471 error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1472 if (error < 0) {
1473 if (error == -ENOSPC) {
1474 sdev_printk(KERN_WARNING, scsidp,
1475 "Unable to attach sg device type=%d, minor number exceeds %d\n",
1476 scsidp->type, SG_MAX_DEVS - 1);
1477 error = -ENODEV;
1478 } else {
1479 sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1480 "allocation Sg_device failure: %d\n",
1481 __func__, error);
1482 }
1483 goto out_unlock;
1484 }
1485 k = error;
1486
1487 SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1488 "sg_alloc: dev=%d \n", k));
1489 sprintf(disk->disk_name, "sg%d", k);
1490 disk->first_minor = k;
1491 sdp->disk = disk;
1492 sdp->device = scsidp;
1493 mutex_init(&sdp->open_rel_lock);
1494 INIT_LIST_HEAD(&sdp->sfds);
1495 init_waitqueue_head(&sdp->open_wait);
1496 atomic_set(&sdp->detaching, 0);
1497 rwlock_init(&sdp->sfd_lock);
1498 sdp->sg_tablesize = queue_max_segments(q);
1499 sdp->index = k;
1500 kref_init(&sdp->d_ref);
1501 error = 0;
1502
1503 out_unlock:
1504 write_unlock_irqrestore(&sg_index_lock, iflags);
1505 idr_preload_end();
1506
1507 if (error) {
1508 kfree(sdp);
1509 return ERR_PTR(error);
1510 }
1511 return sdp;
1512 }
1513
1514 static int
1515 sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
1516 {
1517 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1518 struct gendisk *disk;
1519 Sg_device *sdp = NULL;
1520 struct cdev * cdev = NULL;
1521 int error;
1522 unsigned long iflags;
1523
1524 disk = alloc_disk(1);
1525 if (!disk) {
1526 pr_warn("%s: alloc_disk failed\n", __func__);
1527 return -ENOMEM;
1528 }
1529 disk->major = SCSI_GENERIC_MAJOR;
1530
1531 error = -ENOMEM;
1532 cdev = cdev_alloc();
1533 if (!cdev) {
1534 pr_warn("%s: cdev_alloc failed\n", __func__);
1535 goto out;
1536 }
1537 cdev->owner = THIS_MODULE;
1538 cdev->ops = &sg_fops;
1539
1540 sdp = sg_alloc(disk, scsidp);
1541 if (IS_ERR(sdp)) {
1542 pr_warn("%s: sg_alloc failed\n", __func__);
1543 error = PTR_ERR(sdp);
1544 goto out;
1545 }
1546
1547 error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1548 if (error)
1549 goto cdev_add_err;
1550
1551 sdp->cdev = cdev;
1552 if (sg_sysfs_valid) {
1553 struct device *sg_class_member;
1554
1555 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1556 MKDEV(SCSI_GENERIC_MAJOR,
1557 sdp->index),
1558 sdp, "%s", disk->disk_name);
1559 if (IS_ERR(sg_class_member)) {
1560 pr_err("%s: device_create failed\n", __func__);
1561 error = PTR_ERR(sg_class_member);
1562 goto cdev_add_err;
1563 }
1564 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1565 &sg_class_member->kobj, "generic");
1566 if (error)
1567 pr_err("%s: unable to make symlink 'generic' back "
1568 "to sg%d\n", __func__, sdp->index);
1569 } else
1570 pr_warn("%s: sg_sys Invalid\n", __func__);
1571
1572 sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1573 "type %d\n", sdp->index, scsidp->type);
1574
1575 dev_set_drvdata(cl_dev, sdp);
1576
1577 return 0;
1578
1579 cdev_add_err:
1580 write_lock_irqsave(&sg_index_lock, iflags);
1581 idr_remove(&sg_index_idr, sdp->index);
1582 write_unlock_irqrestore(&sg_index_lock, iflags);
1583 kfree(sdp);
1584
1585 out:
1586 put_disk(disk);
1587 if (cdev)
1588 cdev_del(cdev);
1589 return error;
1590 }
1591
1592 static void
1593 sg_device_destroy(struct kref *kref)
1594 {
1595 struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1596 unsigned long flags;
1597
1598 /* CAUTION! Note that the device can still be found via idr_find()
1599 * even though the refcount is 0. Therefore, do idr_remove() BEFORE
1600 * any other cleanup.
1601 */
1602
1603 write_lock_irqsave(&sg_index_lock, flags);
1604 idr_remove(&sg_index_idr, sdp->index);
1605 write_unlock_irqrestore(&sg_index_lock, flags);
1606
1607 SCSI_LOG_TIMEOUT(3,
1608 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1609
1610 put_disk(sdp->disk);
1611 kfree(sdp);
1612 }
1613
1614 static void
1615 sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
1616 {
1617 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1618 Sg_device *sdp = dev_get_drvdata(cl_dev);
1619 unsigned long iflags;
1620 Sg_fd *sfp;
1621 int val;
1622
1623 if (!sdp)
1624 return;
1625 /* want sdp->detaching non-zero as soon as possible */
1626 val = atomic_inc_return(&sdp->detaching);
1627 if (val > 1)
1628 return; /* only want to do following once per device */
1629
1630 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1631 "%s\n", __func__));
1632
1633 read_lock_irqsave(&sdp->sfd_lock, iflags);
1634 list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1635 wake_up_interruptible_all(&sfp->read_wait);
1636 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1637 }
1638 wake_up_interruptible_all(&sdp->open_wait);
1639 read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1640
1641 sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1642 device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1643 cdev_del(sdp->cdev);
1644 sdp->cdev = NULL;
1645
1646 kref_put(&sdp->d_ref, sg_device_destroy);
1647 }
1648
1649 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1650 module_param_named(def_reserved_size, def_reserved_size, int,
1651 S_IRUGO | S_IWUSR);
1652 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1653
1654 MODULE_AUTHOR("Douglas Gilbert");
1655 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1656 MODULE_LICENSE("GPL");
1657 MODULE_VERSION(SG_VERSION_STR);
1658 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1659
1660 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1661 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1662 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1663 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1664
1665 static int __init
1666 init_sg(void)
1667 {
1668 int rc;
1669
1670 if (scatter_elem_sz < PAGE_SIZE) {
1671 scatter_elem_sz = PAGE_SIZE;
1672 scatter_elem_sz_prev = scatter_elem_sz;
1673 }
1674 if (def_reserved_size >= 0)
1675 sg_big_buff = def_reserved_size;
1676 else
1677 def_reserved_size = sg_big_buff;
1678
1679 rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1680 SG_MAX_DEVS, "sg");
1681 if (rc)
1682 return rc;
1683 sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1684 if ( IS_ERR(sg_sysfs_class) ) {
1685 rc = PTR_ERR(sg_sysfs_class);
1686 goto err_out;
1687 }
1688 sg_sysfs_valid = 1;
1689 rc = scsi_register_interface(&sg_interface);
1690 if (0 == rc) {
1691 #ifdef CONFIG_SCSI_PROC_FS
1692 sg_proc_init();
1693 #endif /* CONFIG_SCSI_PROC_FS */
1694 return 0;
1695 }
1696 class_destroy(sg_sysfs_class);
1697 err_out:
1698 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1699 return rc;
1700 }
1701
1702 static void __exit
1703 exit_sg(void)
1704 {
1705 #ifdef CONFIG_SCSI_PROC_FS
1706 remove_proc_subtree("scsi/sg", NULL);
1707 #endif /* CONFIG_SCSI_PROC_FS */
1708 scsi_unregister_interface(&sg_interface);
1709 class_destroy(sg_sysfs_class);
1710 sg_sysfs_valid = 0;
1711 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1712 SG_MAX_DEVS);
1713 idr_destroy(&sg_index_idr);
1714 }
1715
1716 static int
1717 sg_start_req(Sg_request *srp, unsigned char *cmd)
1718 {
1719 int res;
1720 struct request *rq;
1721 struct scsi_request *req;
1722 Sg_fd *sfp = srp->parentfp;
1723 sg_io_hdr_t *hp = &srp->header;
1724 int dxfer_len = (int) hp->dxfer_len;
1725 int dxfer_dir = hp->dxfer_direction;
1726 unsigned int iov_count = hp->iovec_count;
1727 Sg_scatter_hold *req_schp = &srp->data;
1728 Sg_scatter_hold *rsv_schp = &sfp->reserve;
1729 struct request_queue *q = sfp->parentdp->device->request_queue;
1730 struct rq_map_data *md, map_data;
1731 int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1732 unsigned char *long_cmdp = NULL;
1733
1734 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1735 "sg_start_req: dxfer_len=%d\n",
1736 dxfer_len));
1737
1738 if (hp->cmd_len > BLK_MAX_CDB) {
1739 long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
1740 if (!long_cmdp)
1741 return -ENOMEM;
1742 }
1743
1744 /*
1745 * NOTE
1746 *
1747 * With scsi-mq enabled, there are a fixed number of preallocated
1748 * requests equal in number to shost->can_queue. If all of the
1749 * preallocated requests are already in use, then blk_get_request()
1750 * will sleep until an active command completes, freeing up a request.
1751 * Although waiting in an asynchronous interface is less than ideal, we
1752 * do not want to use BLK_MQ_REQ_NOWAIT here because userspace might
1753 * not expect an EWOULDBLOCK from this condition.
1754 */
1755 rq = blk_get_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
1756 REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
1757 if (IS_ERR(rq)) {
1758 kfree(long_cmdp);
1759 return PTR_ERR(rq);
1760 }
1761 req = scsi_req(rq);
1762
1763 if (hp->cmd_len > BLK_MAX_CDB)
1764 req->cmd = long_cmdp;
1765 memcpy(req->cmd, cmd, hp->cmd_len);
1766 req->cmd_len = hp->cmd_len;
1767
1768 srp->rq = rq;
1769 rq->end_io_data = srp;
1770 req->retries = SG_DEFAULT_RETRIES;
1771
1772 if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1773 return 0;
1774
1775 if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1776 dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1777 !sfp->parentdp->device->host->unchecked_isa_dma &&
1778 blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1779 md = NULL;
1780 else
1781 md = &map_data;
1782
1783 if (md) {
1784 mutex_lock(&sfp->f_mutex);
1785 if (dxfer_len <= rsv_schp->bufflen &&
1786 !sfp->res_in_use) {
1787 sfp->res_in_use = 1;
1788 sg_link_reserve(sfp, srp, dxfer_len);
1789 } else if (hp->flags & SG_FLAG_MMAP_IO) {
1790 res = -EBUSY; /* sfp->res_in_use == 1 */
1791 if (dxfer_len > rsv_schp->bufflen)
1792 res = -ENOMEM;
1793 mutex_unlock(&sfp->f_mutex);
1794 return res;
1795 } else {
1796 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1797 if (res) {
1798 mutex_unlock(&sfp->f_mutex);
1799 return res;
1800 }
1801 }
1802 mutex_unlock(&sfp->f_mutex);
1803
1804 md->pages = req_schp->pages;
1805 md->page_order = req_schp->page_order;
1806 md->nr_entries = req_schp->k_use_sg;
1807 md->offset = 0;
1808 md->null_mapped = hp->dxferp ? 0 : 1;
1809 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1810 md->from_user = 1;
1811 else
1812 md->from_user = 0;
1813 }
1814
1815 if (iov_count) {
1816 struct iovec *iov = NULL;
1817 struct iov_iter i;
1818
1819 #ifdef CONFIG_COMPAT
1820 if (in_compat_syscall())
1821 res = compat_import_iovec(rw, hp->dxferp, iov_count,
1822 0, &iov, &i);
1823 else
1824 #endif
1825 res = import_iovec(rw, hp->dxferp, iov_count,
1826 0, &iov, &i);
1827 if (res < 0)
1828 return res;
1829
1830 iov_iter_truncate(&i, hp->dxfer_len);
1831 if (!iov_iter_count(&i)) {
1832 kfree(iov);
1833 return -EINVAL;
1834 }
1835
1836 res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
1837 kfree(iov);
1838 } else
1839 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1840 hp->dxfer_len, GFP_ATOMIC);
1841
1842 if (!res) {
1843 srp->bio = rq->bio;
1844
1845 if (!md) {
1846 req_schp->dio_in_use = 1;
1847 hp->info |= SG_INFO_DIRECT_IO;
1848 }
1849 }
1850 return res;
1851 }
1852
1853 static int
1854 sg_finish_rem_req(Sg_request *srp)
1855 {
1856 int ret = 0;
1857
1858 Sg_fd *sfp = srp->parentfp;
1859 Sg_scatter_hold *req_schp = &srp->data;
1860
1861 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1862 "sg_finish_rem_req: res_used=%d\n",
1863 (int) srp->res_used));
1864 if (srp->bio)
1865 ret = blk_rq_unmap_user(srp->bio);
1866
1867 if (srp->rq) {
1868 scsi_req_free_cmd(scsi_req(srp->rq));
1869 blk_put_request(srp->rq);
1870 }
1871
1872 if (srp->res_used)
1873 sg_unlink_reserve(sfp, srp);
1874 else
1875 sg_remove_scat(sfp, req_schp);
1876
1877 return ret;
1878 }
1879
1880 static int
1881 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1882 {
1883 int sg_bufflen = tablesize * sizeof(struct page *);
1884 gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1885
1886 schp->pages = kzalloc(sg_bufflen, gfp_flags);
1887 if (!schp->pages)
1888 return -ENOMEM;
1889 schp->sglist_len = sg_bufflen;
1890 return tablesize; /* number of scat_gath elements allocated */
1891 }
1892
1893 static int
1894 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1895 {
1896 int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1897 int sg_tablesize = sfp->parentdp->sg_tablesize;
1898 int blk_size = buff_size, order;
1899 gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
1900 struct sg_device *sdp = sfp->parentdp;
1901
1902 if (blk_size < 0)
1903 return -EFAULT;
1904 if (0 == blk_size)
1905 ++blk_size; /* don't know why */
1906 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1907 blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1908 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1909 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1910 buff_size, blk_size));
1911
1912 /* N.B. ret_sz carried into this block ... */
1913 mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1914 if (mx_sc_elems < 0)
1915 return mx_sc_elems; /* most likely -ENOMEM */
1916
1917 num = scatter_elem_sz;
1918 if (unlikely(num != scatter_elem_sz_prev)) {
1919 if (num < PAGE_SIZE) {
1920 scatter_elem_sz = PAGE_SIZE;
1921 scatter_elem_sz_prev = PAGE_SIZE;
1922 } else
1923 scatter_elem_sz_prev = num;
1924 }
1925
1926 if (sdp->device->host->unchecked_isa_dma)
1927 gfp_mask |= GFP_DMA;
1928
1929 order = get_order(num);
1930 retry:
1931 ret_sz = 1 << (PAGE_SHIFT + order);
1932
1933 for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1934 k++, rem_sz -= ret_sz) {
1935
1936 num = (rem_sz > scatter_elem_sz_prev) ?
1937 scatter_elem_sz_prev : rem_sz;
1938
1939 schp->pages[k] = alloc_pages(gfp_mask, order);
1940 if (!schp->pages[k])
1941 goto out;
1942
1943 if (num == scatter_elem_sz_prev) {
1944 if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1945 scatter_elem_sz = ret_sz;
1946 scatter_elem_sz_prev = ret_sz;
1947 }
1948 }
1949
1950 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1951 "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1952 k, num, ret_sz));
1953 } /* end of for loop */
1954
1955 schp->page_order = order;
1956 schp->k_use_sg = k;
1957 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1958 "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1959 k, rem_sz));
1960
1961 schp->bufflen = blk_size;
1962 if (rem_sz > 0) /* must have failed */
1963 return -ENOMEM;
1964 return 0;
1965 out:
1966 for (i = 0; i < k; i++)
1967 __free_pages(schp->pages[i], order);
1968
1969 if (--order >= 0)
1970 goto retry;
1971
1972 return -ENOMEM;
1973 }
1974
1975 static void
1976 sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1977 {
1978 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1979 "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1980 if (schp->pages && schp->sglist_len > 0) {
1981 if (!schp->dio_in_use) {
1982 int k;
1983
1984 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1985 SCSI_LOG_TIMEOUT(5,
1986 sg_printk(KERN_INFO, sfp->parentdp,
1987 "sg_remove_scat: k=%d, pg=0x%p\n",
1988 k, schp->pages[k]));
1989 __free_pages(schp->pages[k], schp->page_order);
1990 }
1991
1992 kfree(schp->pages);
1993 }
1994 }
1995 memset(schp, 0, sizeof (*schp));
1996 }
1997
1998 static int
1999 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
2000 {
2001 Sg_scatter_hold *schp = &srp->data;
2002 int k, num;
2003
2004 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2005 "sg_read_oxfer: num_read_xfer=%d\n",
2006 num_read_xfer));
2007 if ((!outp) || (num_read_xfer <= 0))
2008 return 0;
2009
2010 num = 1 << (PAGE_SHIFT + schp->page_order);
2011 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
2012 if (num > num_read_xfer) {
2013 if (copy_to_user(outp, page_address(schp->pages[k]),
2014 num_read_xfer))
2015 return -EFAULT;
2016 break;
2017 } else {
2018 if (copy_to_user(outp, page_address(schp->pages[k]),
2019 num))
2020 return -EFAULT;
2021 num_read_xfer -= num;
2022 if (num_read_xfer <= 0)
2023 break;
2024 outp += num;
2025 }
2026 }
2027
2028 return 0;
2029 }
2030
2031 static void
2032 sg_build_reserve(Sg_fd * sfp, int req_size)
2033 {
2034 Sg_scatter_hold *schp = &sfp->reserve;
2035
2036 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2037 "sg_build_reserve: req_size=%d\n", req_size));
2038 do {
2039 if (req_size < PAGE_SIZE)
2040 req_size = PAGE_SIZE;
2041 if (0 == sg_build_indirect(schp, sfp, req_size))
2042 return;
2043 else
2044 sg_remove_scat(sfp, schp);
2045 req_size >>= 1; /* divide by 2 */
2046 } while (req_size > (PAGE_SIZE / 2));
2047 }
2048
2049 static void
2050 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2051 {
2052 Sg_scatter_hold *req_schp = &srp->data;
2053 Sg_scatter_hold *rsv_schp = &sfp->reserve;
2054 int k, num, rem;
2055
2056 srp->res_used = 1;
2057 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2058 "sg_link_reserve: size=%d\n", size));
2059 rem = size;
2060
2061 num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
2062 for (k = 0; k < rsv_schp->k_use_sg; k++) {
2063 if (rem <= num) {
2064 req_schp->k_use_sg = k + 1;
2065 req_schp->sglist_len = rsv_schp->sglist_len;
2066 req_schp->pages = rsv_schp->pages;
2067
2068 req_schp->bufflen = size;
2069 req_schp->page_order = rsv_schp->page_order;
2070 break;
2071 } else
2072 rem -= num;
2073 }
2074
2075 if (k >= rsv_schp->k_use_sg)
2076 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2077 "sg_link_reserve: BAD size\n"));
2078 }
2079
2080 static void
2081 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2082 {
2083 Sg_scatter_hold *req_schp = &srp->data;
2084
2085 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2086 "sg_unlink_reserve: req->k_use_sg=%d\n",
2087 (int) req_schp->k_use_sg));
2088 req_schp->k_use_sg = 0;
2089 req_schp->bufflen = 0;
2090 req_schp->pages = NULL;
2091 req_schp->page_order = 0;
2092 req_schp->sglist_len = 0;
2093 srp->res_used = 0;
2094 /* Called without mutex lock to avoid deadlock */
2095 sfp->res_in_use = 0;
2096 }
2097
2098 static Sg_request *
2099 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2100 {
2101 Sg_request *resp;
2102 unsigned long iflags;
2103
2104 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2105 list_for_each_entry(resp, &sfp->rq_list, entry) {
2106 /* look for requests that are ready + not SG_IO owned */
2107 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2108 ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2109 resp->done = 2; /* guard against other readers */
2110 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2111 return resp;
2112 }
2113 }
2114 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2115 return NULL;
2116 }
2117
2118 /* always adds to end of list */
2119 static Sg_request *
2120 sg_add_request(Sg_fd * sfp)
2121 {
2122 int k;
2123 unsigned long iflags;
2124 Sg_request *rp = sfp->req_arr;
2125
2126 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2127 if (!list_empty(&sfp->rq_list)) {
2128 if (!sfp->cmd_q)
2129 goto out_unlock;
2130
2131 for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2132 if (!rp->parentfp)
2133 break;
2134 }
2135 if (k >= SG_MAX_QUEUE)
2136 goto out_unlock;
2137 }
2138 memset(rp, 0, sizeof (Sg_request));
2139 rp->parentfp = sfp;
2140 rp->header.duration = jiffies_to_msecs(jiffies);
2141 list_add_tail(&rp->entry, &sfp->rq_list);
2142 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2143 return rp;
2144 out_unlock:
2145 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2146 return NULL;
2147 }
2148
2149 /* Return of 1 for found; 0 for not found */
2150 static int
2151 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2152 {
2153 unsigned long iflags;
2154 int res = 0;
2155
2156 if (!sfp || !srp || list_empty(&sfp->rq_list))
2157 return res;
2158 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2159 if (!list_empty(&srp->entry)) {
2160 list_del(&srp->entry);
2161 srp->parentfp = NULL;
2162 res = 1;
2163 }
2164 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2165 return res;
2166 }
2167
2168 static Sg_fd *
2169 sg_add_sfp(Sg_device * sdp)
2170 {
2171 Sg_fd *sfp;
2172 unsigned long iflags;
2173 int bufflen;
2174
2175 sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2176 if (!sfp)
2177 return ERR_PTR(-ENOMEM);
2178
2179 init_waitqueue_head(&sfp->read_wait);
2180 rwlock_init(&sfp->rq_list_lock);
2181 INIT_LIST_HEAD(&sfp->rq_list);
2182 kref_init(&sfp->f_ref);
2183 mutex_init(&sfp->f_mutex);
2184 sfp->timeout = SG_DEFAULT_TIMEOUT;
2185 sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2186 sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2187 sfp->cmd_q = SG_DEF_COMMAND_Q;
2188 sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2189 sfp->parentdp = sdp;
2190 write_lock_irqsave(&sdp->sfd_lock, iflags);
2191 if (atomic_read(&sdp->detaching)) {
2192 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2193 kfree(sfp);
2194 return ERR_PTR(-ENODEV);
2195 }
2196 list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2197 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2198 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2199 "sg_add_sfp: sfp=0x%p\n", sfp));
2200 if (unlikely(sg_big_buff != def_reserved_size))
2201 sg_big_buff = def_reserved_size;
2202
2203 bufflen = min_t(int, sg_big_buff,
2204 max_sectors_bytes(sdp->device->request_queue));
2205 sg_build_reserve(sfp, bufflen);
2206 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2207 "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2208 sfp->reserve.bufflen,
2209 sfp->reserve.k_use_sg));
2210
2211 kref_get(&sdp->d_ref);
2212 __module_get(THIS_MODULE);
2213 return sfp;
2214 }
2215
2216 static void
2217 sg_remove_sfp_usercontext(struct work_struct *work)
2218 {
2219 struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2220 struct sg_device *sdp = sfp->parentdp;
2221 Sg_request *srp;
2222 unsigned long iflags;
2223
2224 /* Cleanup any responses which were never read(). */
2225 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2226 while (!list_empty(&sfp->rq_list)) {
2227 srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2228 sg_finish_rem_req(srp);
2229 list_del(&srp->entry);
2230 srp->parentfp = NULL;
2231 }
2232 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2233
2234 if (sfp->reserve.bufflen > 0) {
2235 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2236 "sg_remove_sfp: bufflen=%d, k_use_sg=%d\n",
2237 (int) sfp->reserve.bufflen,
2238 (int) sfp->reserve.k_use_sg));
2239 sg_remove_scat(sfp, &sfp->reserve);
2240 }
2241
2242 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2243 "sg_remove_sfp: sfp=0x%p\n", sfp));
2244 kfree(sfp);
2245
2246 scsi_device_put(sdp->device);
2247 kref_put(&sdp->d_ref, sg_device_destroy);
2248 module_put(THIS_MODULE);
2249 }
2250
2251 static void
2252 sg_remove_sfp(struct kref *kref)
2253 {
2254 struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2255 struct sg_device *sdp = sfp->parentdp;
2256 unsigned long iflags;
2257
2258 write_lock_irqsave(&sdp->sfd_lock, iflags);
2259 list_del(&sfp->sfd_siblings);
2260 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2261
2262 INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2263 schedule_work(&sfp->ew.work);
2264 }
2265
2266 #ifdef CONFIG_SCSI_PROC_FS
2267 static int
2268 sg_idr_max_id(int id, void *p, void *data)
2269 {
2270 int *k = data;
2271
2272 if (*k < id)
2273 *k = id;
2274
2275 return 0;
2276 }
2277
2278 static int
2279 sg_last_dev(void)
2280 {
2281 int k = -1;
2282 unsigned long iflags;
2283
2284 read_lock_irqsave(&sg_index_lock, iflags);
2285 idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2286 read_unlock_irqrestore(&sg_index_lock, iflags);
2287 return k + 1; /* origin 1 */
2288 }
2289 #endif
2290
2291 /* must be called with sg_index_lock held */
2292 static Sg_device *sg_lookup_dev(int dev)
2293 {
2294 return idr_find(&sg_index_idr, dev);
2295 }
2296
2297 static Sg_device *
2298 sg_get_dev(int dev)
2299 {
2300 struct sg_device *sdp;
2301 unsigned long flags;
2302
2303 read_lock_irqsave(&sg_index_lock, flags);
2304 sdp = sg_lookup_dev(dev);
2305 if (!sdp)
2306 sdp = ERR_PTR(-ENXIO);
2307 else if (atomic_read(&sdp->detaching)) {
2308 /* If sdp->detaching, then the refcount may already be 0, in
2309 * which case it would be a bug to do kref_get().
2310 */
2311 sdp = ERR_PTR(-ENODEV);
2312 } else
2313 kref_get(&sdp->d_ref);
2314 read_unlock_irqrestore(&sg_index_lock, flags);
2315
2316 return sdp;
2317 }
2318
2319 #ifdef CONFIG_SCSI_PROC_FS
2320 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2321
2322 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2323 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2324 size_t count, loff_t *off);
2325 static const struct proc_ops adio_proc_ops = {
2326 .proc_open = sg_proc_single_open_adio,
2327 .proc_read = seq_read,
2328 .proc_lseek = seq_lseek,
2329 .proc_write = sg_proc_write_adio,
2330 .proc_release = single_release,
2331 };
2332
2333 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2334 static ssize_t sg_proc_write_dressz(struct file *filp,
2335 const char __user *buffer, size_t count, loff_t *off);
2336 static const struct proc_ops dressz_proc_ops = {
2337 .proc_open = sg_proc_single_open_dressz,
2338 .proc_read = seq_read,
2339 .proc_lseek = seq_lseek,
2340 .proc_write = sg_proc_write_dressz,
2341 .proc_release = single_release,
2342 };
2343
2344 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2345 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2346 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2347 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2348 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2349 static void dev_seq_stop(struct seq_file *s, void *v);
2350 static const struct seq_operations dev_seq_ops = {
2351 .start = dev_seq_start,
2352 .next = dev_seq_next,
2353 .stop = dev_seq_stop,
2354 .show = sg_proc_seq_show_dev,
2355 };
2356
2357 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2358 static const struct seq_operations devstrs_seq_ops = {
2359 .start = dev_seq_start,
2360 .next = dev_seq_next,
2361 .stop = dev_seq_stop,
2362 .show = sg_proc_seq_show_devstrs,
2363 };
2364
2365 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2366 static const struct seq_operations debug_seq_ops = {
2367 .start = dev_seq_start,
2368 .next = dev_seq_next,
2369 .stop = dev_seq_stop,
2370 .show = sg_proc_seq_show_debug,
2371 };
2372
2373 static int
2374 sg_proc_init(void)
2375 {
2376 struct proc_dir_entry *p;
2377
2378 p = proc_mkdir("scsi/sg", NULL);
2379 if (!p)
2380 return 1;
2381
2382 proc_create("allow_dio", S_IRUGO | S_IWUSR, p, &adio_proc_ops);
2383 proc_create_seq("debug", S_IRUGO, p, &debug_seq_ops);
2384 proc_create("def_reserved_size", S_IRUGO | S_IWUSR, p, &dressz_proc_ops);
2385 proc_create_single("device_hdr", S_IRUGO, p, sg_proc_seq_show_devhdr);
2386 proc_create_seq("devices", S_IRUGO, p, &dev_seq_ops);
2387 proc_create_seq("device_strs", S_IRUGO, p, &devstrs_seq_ops);
2388 proc_create_single("version", S_IRUGO, p, sg_proc_seq_show_version);
2389 return 0;
2390 }
2391
2392
2393 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2394 {
2395 seq_printf(s, "%d\n", *((int *)s->private));
2396 return 0;
2397 }
2398
2399 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2400 {
2401 return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2402 }
2403
2404 static ssize_t
2405 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2406 size_t count, loff_t *off)
2407 {
2408 int err;
2409 unsigned long num;
2410
2411 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2412 return -EACCES;
2413 err = kstrtoul_from_user(buffer, count, 0, &num);
2414 if (err)
2415 return err;
2416 sg_allow_dio = num ? 1 : 0;
2417 return count;
2418 }
2419
2420 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2421 {
2422 return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2423 }
2424
2425 static ssize_t
2426 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2427 size_t count, loff_t *off)
2428 {
2429 int err;
2430 unsigned long k = ULONG_MAX;
2431
2432 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2433 return -EACCES;
2434
2435 err = kstrtoul_from_user(buffer, count, 0, &k);
2436 if (err)
2437 return err;
2438 if (k <= 1048576) { /* limit "big buff" to 1 MB */
2439 sg_big_buff = k;
2440 return count;
2441 }
2442 return -ERANGE;
2443 }
2444
2445 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2446 {
2447 seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2448 sg_version_date);
2449 return 0;
2450 }
2451
2452 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2453 {
2454 seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2455 return 0;
2456 }
2457
2458 struct sg_proc_deviter {
2459 loff_t index;
2460 size_t max;
2461 };
2462
2463 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2464 {
2465 struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2466
2467 s->private = it;
2468 if (! it)
2469 return NULL;
2470
2471 it->index = *pos;
2472 it->max = sg_last_dev();
2473 if (it->index >= it->max)
2474 return NULL;
2475 return it;
2476 }
2477
2478 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2479 {
2480 struct sg_proc_deviter * it = s->private;
2481
2482 *pos = ++it->index;
2483 return (it->index < it->max) ? it : NULL;
2484 }
2485
2486 static void dev_seq_stop(struct seq_file *s, void *v)
2487 {
2488 kfree(s->private);
2489 }
2490
2491 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2492 {
2493 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2494 Sg_device *sdp;
2495 struct scsi_device *scsidp;
2496 unsigned long iflags;
2497
2498 read_lock_irqsave(&sg_index_lock, iflags);
2499 sdp = it ? sg_lookup_dev(it->index) : NULL;
2500 if ((NULL == sdp) || (NULL == sdp->device) ||
2501 (atomic_read(&sdp->detaching)))
2502 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2503 else {
2504 scsidp = sdp->device;
2505 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2506 scsidp->host->host_no, scsidp->channel,
2507 scsidp->id, scsidp->lun, (int) scsidp->type,
2508 1,
2509 (int) scsidp->queue_depth,
2510 (int) atomic_read(&scsidp->device_busy),
2511 (int) scsi_device_online(scsidp));
2512 }
2513 read_unlock_irqrestore(&sg_index_lock, iflags);
2514 return 0;
2515 }
2516
2517 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2518 {
2519 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2520 Sg_device *sdp;
2521 struct scsi_device *scsidp;
2522 unsigned long iflags;
2523
2524 read_lock_irqsave(&sg_index_lock, iflags);
2525 sdp = it ? sg_lookup_dev(it->index) : NULL;
2526 scsidp = sdp ? sdp->device : NULL;
2527 if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2528 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2529 scsidp->vendor, scsidp->model, scsidp->rev);
2530 else
2531 seq_puts(s, "<no active device>\n");
2532 read_unlock_irqrestore(&sg_index_lock, iflags);
2533 return 0;
2534 }
2535
2536 /* must be called while holding sg_index_lock */
2537 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2538 {
2539 int k, new_interface, blen, usg;
2540 Sg_request *srp;
2541 Sg_fd *fp;
2542 const sg_io_hdr_t *hp;
2543 const char * cp;
2544 unsigned int ms;
2545
2546 k = 0;
2547 list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2548 k++;
2549 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2550 seq_printf(s, " FD(%d): timeout=%dms bufflen=%d "
2551 "(res)sgat=%d low_dma=%d\n", k,
2552 jiffies_to_msecs(fp->timeout),
2553 fp->reserve.bufflen,
2554 (int) fp->reserve.k_use_sg,
2555 (int) sdp->device->host->unchecked_isa_dma);
2556 seq_printf(s, " cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2557 (int) fp->cmd_q, (int) fp->force_packid,
2558 (int) fp->keep_orphan);
2559 list_for_each_entry(srp, &fp->rq_list, entry) {
2560 hp = &srp->header;
2561 new_interface = (hp->interface_id == '\0') ? 0 : 1;
2562 if (srp->res_used) {
2563 if (new_interface &&
2564 (SG_FLAG_MMAP_IO & hp->flags))
2565 cp = " mmap>> ";
2566 else
2567 cp = " rb>> ";
2568 } else {
2569 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2570 cp = " dio>> ";
2571 else
2572 cp = " ";
2573 }
2574 seq_puts(s, cp);
2575 blen = srp->data.bufflen;
2576 usg = srp->data.k_use_sg;
2577 seq_puts(s, srp->done ?
2578 ((1 == srp->done) ? "rcv:" : "fin:")
2579 : "act:");
2580 seq_printf(s, " id=%d blen=%d",
2581 srp->header.pack_id, blen);
2582 if (srp->done)
2583 seq_printf(s, " dur=%d", hp->duration);
2584 else {
2585 ms = jiffies_to_msecs(jiffies);
2586 seq_printf(s, " t_o/elap=%d/%d",
2587 (new_interface ? hp->timeout :
2588 jiffies_to_msecs(fp->timeout)),
2589 (ms > hp->duration ? ms - hp->duration : 0));
2590 }
2591 seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2592 (int) srp->data.cmd_opcode);
2593 }
2594 if (list_empty(&fp->rq_list))
2595 seq_puts(s, " No requests active\n");
2596 read_unlock(&fp->rq_list_lock);
2597 }
2598 }
2599
2600 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2601 {
2602 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2603 Sg_device *sdp;
2604 unsigned long iflags;
2605
2606 if (it && (0 == it->index))
2607 seq_printf(s, "max_active_device=%d def_reserved_size=%d\n",
2608 (int)it->max, sg_big_buff);
2609
2610 read_lock_irqsave(&sg_index_lock, iflags);
2611 sdp = it ? sg_lookup_dev(it->index) : NULL;
2612 if (NULL == sdp)
2613 goto skip;
2614 read_lock(&sdp->sfd_lock);
2615 if (!list_empty(&sdp->sfds)) {
2616 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2617 if (atomic_read(&sdp->detaching))
2618 seq_puts(s, "detaching pending close ");
2619 else if (sdp->device) {
2620 struct scsi_device *scsidp = sdp->device;
2621
2622 seq_printf(s, "%d:%d:%d:%llu em=%d",
2623 scsidp->host->host_no,
2624 scsidp->channel, scsidp->id,
2625 scsidp->lun,
2626 scsidp->host->hostt->emulated);
2627 }
2628 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2629 sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2630 sg_proc_debug_helper(s, sdp);
2631 }
2632 read_unlock(&sdp->sfd_lock);
2633 skip:
2634 read_unlock_irqrestore(&sg_index_lock, iflags);
2635 return 0;
2636 }
2637
2638 #endif /* CONFIG_SCSI_PROC_FS */
2639
2640 module_init(init_sg);
2641 module_exit(exit_sg);
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