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