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perf intel-pt: Factor out intel_pt_8b_tsc()
[linux/fpc-iii.git] / drivers / scsi / sg.c
blobcce7575063839abc5aebd02f4f03933508b3039c
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 ssize_t
409 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
410 {
411 Sg_device *sdp;
412 Sg_fd *sfp;
413 Sg_request *srp;
414 int req_pack_id = -1;
415 sg_io_hdr_t *hp;
416 struct sg_header *old_hdr = NULL;
417 int retval = 0;
418
419 /*
420 * This could cause a response to be stranded. Close the associated
421 * file descriptor to free up any resources being held.
422 */
423 retval = sg_check_file_access(filp, __func__);
424 if (retval)
425 return retval;
426
427 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
428 return -ENXIO;
429 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
430 "sg_read: count=%d\n", (int) count));
431
432 if (!access_ok(buf, count))
433 return -EFAULT;
434 if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
435 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
436 if (!old_hdr)
437 return -ENOMEM;
438 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
439 retval = -EFAULT;
440 goto free_old_hdr;
441 }
442 if (old_hdr->reply_len < 0) {
443 if (count >= SZ_SG_IO_HDR) {
444 sg_io_hdr_t *new_hdr;
445 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
446 if (!new_hdr) {
447 retval = -ENOMEM;
448 goto free_old_hdr;
449 }
450 retval =__copy_from_user
451 (new_hdr, buf, SZ_SG_IO_HDR);
452 req_pack_id = new_hdr->pack_id;
453 kfree(new_hdr);
454 if (retval) {
455 retval = -EFAULT;
456 goto free_old_hdr;
457 }
458 }
459 } else
460 req_pack_id = old_hdr->pack_id;
461 }
462 srp = sg_get_rq_mark(sfp, req_pack_id);
463 if (!srp) { /* now wait on packet to arrive */
464 if (atomic_read(&sdp->detaching)) {
465 retval = -ENODEV;
466 goto free_old_hdr;
467 }
468 if (filp->f_flags & O_NONBLOCK) {
469 retval = -EAGAIN;
470 goto free_old_hdr;
471 }
472 retval = wait_event_interruptible(sfp->read_wait,
473 (atomic_read(&sdp->detaching) ||
474 (srp = sg_get_rq_mark(sfp, req_pack_id))));
475 if (atomic_read(&sdp->detaching)) {
476 retval = -ENODEV;
477 goto free_old_hdr;
478 }
479 if (retval) {
480 /* -ERESTARTSYS as signal hit process */
481 goto free_old_hdr;
482 }
483 }
484 if (srp->header.interface_id != '\0') {
485 retval = sg_new_read(sfp, buf, count, srp);
486 goto free_old_hdr;
487 }
488
489 hp = &srp->header;
490 if (old_hdr == NULL) {
491 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
492 if (! old_hdr) {
493 retval = -ENOMEM;
494 goto free_old_hdr;
495 }
496 }
497 memset(old_hdr, 0, SZ_SG_HEADER);
498 old_hdr->reply_len = (int) hp->timeout;
499 old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
500 old_hdr->pack_id = hp->pack_id;
501 old_hdr->twelve_byte =
502 ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
503 old_hdr->target_status = hp->masked_status;
504 old_hdr->host_status = hp->host_status;
505 old_hdr->driver_status = hp->driver_status;
506 if ((CHECK_CONDITION & hp->masked_status) ||
507 (DRIVER_SENSE & hp->driver_status))
508 memcpy(old_hdr->sense_buffer, srp->sense_b,
509 sizeof (old_hdr->sense_buffer));
510 switch (hp->host_status) {
511 /* This setup of 'result' is for backward compatibility and is best
512 ignored by the user who should use target, host + driver status */
513 case DID_OK:
514 case DID_PASSTHROUGH:
515 case DID_SOFT_ERROR:
516 old_hdr->result = 0;
517 break;
518 case DID_NO_CONNECT:
519 case DID_BUS_BUSY:
520 case DID_TIME_OUT:
521 old_hdr->result = EBUSY;
522 break;
523 case DID_BAD_TARGET:
524 case DID_ABORT:
525 case DID_PARITY:
526 case DID_RESET:
527 case DID_BAD_INTR:
528 old_hdr->result = EIO;
529 break;
530 case DID_ERROR:
531 old_hdr->result = (srp->sense_b[0] == 0 &&
532 hp->masked_status == GOOD) ? 0 : EIO;
533 break;
534 default:
535 old_hdr->result = EIO;
536 break;
537 }
538
539 /* Now copy the result back to the user buffer. */
540 if (count >= SZ_SG_HEADER) {
541 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
542 retval = -EFAULT;
543 goto free_old_hdr;
544 }
545 buf += SZ_SG_HEADER;
546 if (count > old_hdr->reply_len)
547 count = old_hdr->reply_len;
548 if (count > SZ_SG_HEADER) {
549 if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
550 retval = -EFAULT;
551 goto free_old_hdr;
552 }
553 }
554 } else
555 count = (old_hdr->result == 0) ? 0 : -EIO;
556 sg_finish_rem_req(srp);
557 sg_remove_request(sfp, srp);
558 retval = count;
559 free_old_hdr:
560 kfree(old_hdr);
561 return retval;
562 }
563
564 static ssize_t
565 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
566 {
567 sg_io_hdr_t *hp = &srp->header;
568 int err = 0, err2;
569 int len;
570
571 if (count < SZ_SG_IO_HDR) {
572 err = -EINVAL;
573 goto err_out;
574 }
575 hp->sb_len_wr = 0;
576 if ((hp->mx_sb_len > 0) && hp->sbp) {
577 if ((CHECK_CONDITION & hp->masked_status) ||
578 (DRIVER_SENSE & hp->driver_status)) {
579 int sb_len = SCSI_SENSE_BUFFERSIZE;
580 sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
581 len = 8 + (int) srp->sense_b[7]; /* Additional sense length field */
582 len = (len > sb_len) ? sb_len : len;
583 if (copy_to_user(hp->sbp, srp->sense_b, len)) {
584 err = -EFAULT;
585 goto err_out;
586 }
587 hp->sb_len_wr = len;
588 }
589 }
590 if (hp->masked_status || hp->host_status || hp->driver_status)
591 hp->info |= SG_INFO_CHECK;
592 if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
593 err = -EFAULT;
594 goto err_out;
595 }
596 err_out:
597 err2 = sg_finish_rem_req(srp);
598 sg_remove_request(sfp, srp);
599 return err ? : err2 ? : count;
600 }
601
602 static ssize_t
603 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
604 {
605 int mxsize, cmd_size, k;
606 int input_size, blocking;
607 unsigned char opcode;
608 Sg_device *sdp;
609 Sg_fd *sfp;
610 Sg_request *srp;
611 struct sg_header old_hdr;
612 sg_io_hdr_t *hp;
613 unsigned char cmnd[SG_MAX_CDB_SIZE];
614 int retval;
615
616 retval = sg_check_file_access(filp, __func__);
617 if (retval)
618 return retval;
619
620 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
621 return -ENXIO;
622 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
623 "sg_write: count=%d\n", (int) count));
624 if (atomic_read(&sdp->detaching))
625 return -ENODEV;
626 if (!((filp->f_flags & O_NONBLOCK) ||
627 scsi_block_when_processing_errors(sdp->device)))
628 return -ENXIO;
629
630 if (!access_ok(buf, count))
631 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
632 if (count < SZ_SG_HEADER)
633 return -EIO;
634 if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
635 return -EFAULT;
636 blocking = !(filp->f_flags & O_NONBLOCK);
637 if (old_hdr.reply_len < 0)
638 return sg_new_write(sfp, filp, buf, count,
639 blocking, 0, 0, NULL);
640 if (count < (SZ_SG_HEADER + 6))
641 return -EIO; /* The minimum scsi command length is 6 bytes. */
642
643 if (!(srp = sg_add_request(sfp))) {
644 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
645 "sg_write: queue full\n"));
646 return -EDOM;
647 }
648 buf += SZ_SG_HEADER;
649 __get_user(opcode, buf);
650 mutex_lock(&sfp->f_mutex);
651 if (sfp->next_cmd_len > 0) {
652 cmd_size = sfp->next_cmd_len;
653 sfp->next_cmd_len = 0; /* reset so only this write() effected */
654 } else {
655 cmd_size = COMMAND_SIZE(opcode); /* based on SCSI command group */
656 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
657 cmd_size = 12;
658 }
659 mutex_unlock(&sfp->f_mutex);
660 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
661 "sg_write: scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
662 /* Determine buffer size. */
663 input_size = count - cmd_size;
664 mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
665 mxsize -= SZ_SG_HEADER;
666 input_size -= SZ_SG_HEADER;
667 if (input_size < 0) {
668 sg_remove_request(sfp, srp);
669 return -EIO; /* User did not pass enough bytes for this command. */
670 }
671 hp = &srp->header;
672 hp->interface_id = '\0'; /* indicator of old interface tunnelled */
673 hp->cmd_len = (unsigned char) cmd_size;
674 hp->iovec_count = 0;
675 hp->mx_sb_len = 0;
676 if (input_size > 0)
677 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
678 SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
679 else
680 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
681 hp->dxfer_len = mxsize;
682 if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
683 (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
684 hp->dxferp = (char __user *)buf + cmd_size;
685 else
686 hp->dxferp = NULL;
687 hp->sbp = NULL;
688 hp->timeout = old_hdr.reply_len; /* structure abuse ... */
689 hp->flags = input_size; /* structure abuse ... */
690 hp->pack_id = old_hdr.pack_id;
691 hp->usr_ptr = NULL;
692 if (__copy_from_user(cmnd, buf, cmd_size))
693 return -EFAULT;
694 /*
695 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
696 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
697 * is a non-zero input_size, so emit a warning.
698 */
699 if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
700 printk_ratelimited(KERN_WARNING
701 "sg_write: data in/out %d/%d bytes "
702 "for SCSI command 0x%x-- guessing "
703 "data in;\n program %s not setting "
704 "count and/or reply_len properly\n",
705 old_hdr.reply_len - (int)SZ_SG_HEADER,
706 input_size, (unsigned int) cmnd[0],
707 current->comm);
708 }
709 k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
710 return (k < 0) ? k : count;
711 }
712
713 static ssize_t
714 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
715 size_t count, int blocking, int read_only, int sg_io_owned,
716 Sg_request **o_srp)
717 {
718 int k;
719 Sg_request *srp;
720 sg_io_hdr_t *hp;
721 unsigned char cmnd[SG_MAX_CDB_SIZE];
722 int timeout;
723 unsigned long ul_timeout;
724
725 if (count < SZ_SG_IO_HDR)
726 return -EINVAL;
727 if (!access_ok(buf, count))
728 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
729
730 sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
731 if (!(srp = sg_add_request(sfp))) {
732 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
733 "sg_new_write: queue full\n"));
734 return -EDOM;
735 }
736 srp->sg_io_owned = sg_io_owned;
737 hp = &srp->header;
738 if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
739 sg_remove_request(sfp, srp);
740 return -EFAULT;
741 }
742 if (hp->interface_id != 'S') {
743 sg_remove_request(sfp, srp);
744 return -ENOSYS;
745 }
746 if (hp->flags & SG_FLAG_MMAP_IO) {
747 if (hp->dxfer_len > sfp->reserve.bufflen) {
748 sg_remove_request(sfp, srp);
749 return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
750 }
751 if (hp->flags & SG_FLAG_DIRECT_IO) {
752 sg_remove_request(sfp, srp);
753 return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
754 }
755 if (sfp->res_in_use) {
756 sg_remove_request(sfp, srp);
757 return -EBUSY; /* reserve buffer already being used */
758 }
759 }
760 ul_timeout = msecs_to_jiffies(srp->header.timeout);
761 timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
762 if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
763 sg_remove_request(sfp, srp);
764 return -EMSGSIZE;
765 }
766 if (!access_ok(hp->cmdp, hp->cmd_len)) {
767 sg_remove_request(sfp, srp);
768 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
769 }
770 if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
771 sg_remove_request(sfp, srp);
772 return -EFAULT;
773 }
774 if (read_only && sg_allow_access(file, cmnd)) {
775 sg_remove_request(sfp, srp);
776 return -EPERM;
777 }
778 k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
779 if (k < 0)
780 return k;
781 if (o_srp)
782 *o_srp = srp;
783 return count;
784 }
785
786 static int
787 sg_common_write(Sg_fd * sfp, Sg_request * srp,
788 unsigned char *cmnd, int timeout, int blocking)
789 {
790 int k, at_head;
791 Sg_device *sdp = sfp->parentdp;
792 sg_io_hdr_t *hp = &srp->header;
793
794 srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
795 hp->status = 0;
796 hp->masked_status = 0;
797 hp->msg_status = 0;
798 hp->info = 0;
799 hp->host_status = 0;
800 hp->driver_status = 0;
801 hp->resid = 0;
802 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
803 "sg_common_write: scsi opcode=0x%02x, cmd_size=%d\n",
804 (int) cmnd[0], (int) hp->cmd_len));
805
806 if (hp->dxfer_len >= SZ_256M)
807 return -EINVAL;
808
809 k = sg_start_req(srp, cmnd);
810 if (k) {
811 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
812 "sg_common_write: start_req err=%d\n", k));
813 sg_finish_rem_req(srp);
814 sg_remove_request(sfp, srp);
815 return k; /* probably out of space --> ENOMEM */
816 }
817 if (atomic_read(&sdp->detaching)) {
818 if (srp->bio) {
819 scsi_req_free_cmd(scsi_req(srp->rq));
820 blk_put_request(srp->rq);
821 srp->rq = NULL;
822 }
823
824 sg_finish_rem_req(srp);
825 sg_remove_request(sfp, srp);
826 return -ENODEV;
827 }
828
829 hp->duration = jiffies_to_msecs(jiffies);
830 if (hp->interface_id != '\0' && /* v3 (or later) interface */
831 (SG_FLAG_Q_AT_TAIL & hp->flags))
832 at_head = 0;
833 else
834 at_head = 1;
835
836 srp->rq->timeout = timeout;
837 kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
838 blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
839 srp->rq, at_head, sg_rq_end_io);
840 return 0;
841 }
842
843 static int srp_done(Sg_fd *sfp, Sg_request *srp)
844 {
845 unsigned long flags;
846 int ret;
847
848 read_lock_irqsave(&sfp->rq_list_lock, flags);
849 ret = srp->done;
850 read_unlock_irqrestore(&sfp->rq_list_lock, flags);
851 return ret;
852 }
853
854 static int max_sectors_bytes(struct request_queue *q)
855 {
856 unsigned int max_sectors = queue_max_sectors(q);
857
858 max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
859
860 return max_sectors << 9;
861 }
862
863 static void
864 sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
865 {
866 Sg_request *srp;
867 int val;
868 unsigned int ms;
869
870 val = 0;
871 list_for_each_entry(srp, &sfp->rq_list, entry) {
872 if (val >= SG_MAX_QUEUE)
873 break;
874 rinfo[val].req_state = srp->done + 1;
875 rinfo[val].problem =
876 srp->header.masked_status &
877 srp->header.host_status &
878 srp->header.driver_status;
879 if (srp->done)
880 rinfo[val].duration =
881 srp->header.duration;
882 else {
883 ms = jiffies_to_msecs(jiffies);
884 rinfo[val].duration =
885 (ms > srp->header.duration) ?
886 (ms - srp->header.duration) : 0;
887 }
888 rinfo[val].orphan = srp->orphan;
889 rinfo[val].sg_io_owned = srp->sg_io_owned;
890 rinfo[val].pack_id = srp->header.pack_id;
891 rinfo[val].usr_ptr = srp->header.usr_ptr;
892 val++;
893 }
894 }
895
896 static long
897 sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
898 {
899 void __user *p = (void __user *)arg;
900 int __user *ip = p;
901 int result, val, read_only;
902 Sg_device *sdp;
903 Sg_fd *sfp;
904 Sg_request *srp;
905 unsigned long iflags;
906
907 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
908 return -ENXIO;
909
910 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
911 "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
912 read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
913
914 switch (cmd_in) {
915 case SG_IO:
916 if (atomic_read(&sdp->detaching))
917 return -ENODEV;
918 if (!scsi_block_when_processing_errors(sdp->device))
919 return -ENXIO;
920 if (!access_ok(p, SZ_SG_IO_HDR))
921 return -EFAULT;
922 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
923 1, read_only, 1, &srp);
924 if (result < 0)
925 return result;
926 result = wait_event_interruptible(sfp->read_wait,
927 (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
928 if (atomic_read(&sdp->detaching))
929 return -ENODEV;
930 write_lock_irq(&sfp->rq_list_lock);
931 if (srp->done) {
932 srp->done = 2;
933 write_unlock_irq(&sfp->rq_list_lock);
934 result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
935 return (result < 0) ? result : 0;
936 }
937 srp->orphan = 1;
938 write_unlock_irq(&sfp->rq_list_lock);
939 return result; /* -ERESTARTSYS because signal hit process */
940 case SG_SET_TIMEOUT:
941 result = get_user(val, ip);
942 if (result)
943 return result;
944 if (val < 0)
945 return -EIO;
946 if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
947 val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
948 INT_MAX);
949 sfp->timeout_user = val;
950 sfp->timeout = mult_frac(val, HZ, USER_HZ);
951
952 return 0;
953 case SG_GET_TIMEOUT: /* N.B. User receives timeout as return value */
954 /* strange ..., for backward compatibility */
955 return sfp->timeout_user;
956 case SG_SET_FORCE_LOW_DMA:
957 /*
958 * N.B. This ioctl never worked properly, but failed to
959 * return an error value. So returning '0' to keep compability
960 * with legacy applications.
961 */
962 return 0;
963 case SG_GET_LOW_DMA:
964 return put_user((int) sdp->device->host->unchecked_isa_dma, ip);
965 case SG_GET_SCSI_ID:
966 if (!access_ok(p, sizeof (sg_scsi_id_t)))
967 return -EFAULT;
968 else {
969 sg_scsi_id_t __user *sg_idp = p;
970
971 if (atomic_read(&sdp->detaching))
972 return -ENODEV;
973 __put_user((int) sdp->device->host->host_no,
974 &sg_idp->host_no);
975 __put_user((int) sdp->device->channel,
976 &sg_idp->channel);
977 __put_user((int) sdp->device->id, &sg_idp->scsi_id);
978 __put_user((int) sdp->device->lun, &sg_idp->lun);
979 __put_user((int) sdp->device->type, &sg_idp->scsi_type);
980 __put_user((short) sdp->device->host->cmd_per_lun,
981 &sg_idp->h_cmd_per_lun);
982 __put_user((short) sdp->device->queue_depth,
983 &sg_idp->d_queue_depth);
984 __put_user(0, &sg_idp->unused[0]);
985 __put_user(0, &sg_idp->unused[1]);
986 return 0;
987 }
988 case SG_SET_FORCE_PACK_ID:
989 result = get_user(val, ip);
990 if (result)
991 return result;
992 sfp->force_packid = val ? 1 : 0;
993 return 0;
994 case SG_GET_PACK_ID:
995 if (!access_ok(ip, sizeof (int)))
996 return -EFAULT;
997 read_lock_irqsave(&sfp->rq_list_lock, iflags);
998 list_for_each_entry(srp, &sfp->rq_list, entry) {
999 if ((1 == srp->done) && (!srp->sg_io_owned)) {
1000 read_unlock_irqrestore(&sfp->rq_list_lock,
1001 iflags);
1002 __put_user(srp->header.pack_id, ip);
1003 return 0;
1004 }
1005 }
1006 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1007 __put_user(-1, ip);
1008 return 0;
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 if (!access_ok(p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
1077 return -EFAULT;
1078 else {
1079 sg_req_info_t *rinfo;
1080
1081 rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
1082 GFP_KERNEL);
1083 if (!rinfo)
1084 return -ENOMEM;
1085 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1086 sg_fill_request_table(sfp, rinfo);
1087 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1088 result = __copy_to_user(p, rinfo,
1089 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1090 result = result ? -EFAULT : 0;
1091 kfree(rinfo);
1092 return result;
1093 }
1094 case SG_EMULATED_HOST:
1095 if (atomic_read(&sdp->detaching))
1096 return -ENODEV;
1097 return put_user(sdp->device->host->hostt->emulated, ip);
1098 case SCSI_IOCTL_SEND_COMMAND:
1099 if (atomic_read(&sdp->detaching))
1100 return -ENODEV;
1101 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1102 case SG_SET_DEBUG:
1103 result = get_user(val, ip);
1104 if (result)
1105 return result;
1106 sdp->sgdebug = (char) val;
1107 return 0;
1108 case BLKSECTGET:
1109 return put_user(max_sectors_bytes(sdp->device->request_queue),
1110 ip);
1111 case BLKTRACESETUP:
1112 return blk_trace_setup(sdp->device->request_queue,
1113 sdp->disk->disk_name,
1114 MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1115 NULL, p);
1116 case BLKTRACESTART:
1117 return blk_trace_startstop(sdp->device->request_queue, 1);
1118 case BLKTRACESTOP:
1119 return blk_trace_startstop(sdp->device->request_queue, 0);
1120 case BLKTRACETEARDOWN:
1121 return blk_trace_remove(sdp->device->request_queue);
1122 case SCSI_IOCTL_GET_IDLUN:
1123 case SCSI_IOCTL_GET_BUS_NUMBER:
1124 case SCSI_IOCTL_PROBE_HOST:
1125 case SG_GET_TRANSFORM:
1126 case SG_SCSI_RESET:
1127 if (atomic_read(&sdp->detaching))
1128 return -ENODEV;
1129 break;
1130 default:
1131 if (read_only)
1132 return -EPERM; /* don't know so take safe approach */
1133 break;
1134 }
1135
1136 result = scsi_ioctl_block_when_processing_errors(sdp->device,
1137 cmd_in, filp->f_flags & O_NDELAY);
1138 if (result)
1139 return result;
1140 return scsi_ioctl(sdp->device, cmd_in, p);
1141 }
1142
1143 #ifdef CONFIG_COMPAT
1144 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1145 {
1146 Sg_device *sdp;
1147 Sg_fd *sfp;
1148 struct scsi_device *sdev;
1149
1150 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1151 return -ENXIO;
1152
1153 sdev = sdp->device;
1154 if (sdev->host->hostt->compat_ioctl) {
1155 int ret;
1156
1157 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1158
1159 return ret;
1160 }
1161
1162 return -ENOIOCTLCMD;
1163 }
1164 #endif
1165
1166 static __poll_t
1167 sg_poll(struct file *filp, poll_table * wait)
1168 {
1169 __poll_t res = 0;
1170 Sg_device *sdp;
1171 Sg_fd *sfp;
1172 Sg_request *srp;
1173 int count = 0;
1174 unsigned long iflags;
1175
1176 sfp = filp->private_data;
1177 if (!sfp)
1178 return EPOLLERR;
1179 sdp = sfp->parentdp;
1180 if (!sdp)
1181 return EPOLLERR;
1182 poll_wait(filp, &sfp->read_wait, wait);
1183 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1184 list_for_each_entry(srp, &sfp->rq_list, entry) {
1185 /* if any read waiting, flag it */
1186 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1187 res = EPOLLIN | EPOLLRDNORM;
1188 ++count;
1189 }
1190 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1191
1192 if (atomic_read(&sdp->detaching))
1193 res |= EPOLLHUP;
1194 else if (!sfp->cmd_q) {
1195 if (0 == count)
1196 res |= EPOLLOUT | EPOLLWRNORM;
1197 } else if (count < SG_MAX_QUEUE)
1198 res |= EPOLLOUT | EPOLLWRNORM;
1199 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1200 "sg_poll: res=0x%x\n", (__force u32) res));
1201 return res;
1202 }
1203
1204 static int
1205 sg_fasync(int fd, struct file *filp, int mode)
1206 {
1207 Sg_device *sdp;
1208 Sg_fd *sfp;
1209
1210 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1211 return -ENXIO;
1212 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1213 "sg_fasync: mode=%d\n", mode));
1214
1215 return fasync_helper(fd, filp, mode, &sfp->async_qp);
1216 }
1217
1218 static vm_fault_t
1219 sg_vma_fault(struct vm_fault *vmf)
1220 {
1221 struct vm_area_struct *vma = vmf->vma;
1222 Sg_fd *sfp;
1223 unsigned long offset, len, sa;
1224 Sg_scatter_hold *rsv_schp;
1225 int k, length;
1226
1227 if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1228 return VM_FAULT_SIGBUS;
1229 rsv_schp = &sfp->reserve;
1230 offset = vmf->pgoff << PAGE_SHIFT;
1231 if (offset >= rsv_schp->bufflen)
1232 return VM_FAULT_SIGBUS;
1233 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1234 "sg_vma_fault: offset=%lu, scatg=%d\n",
1235 offset, rsv_schp->k_use_sg));
1236 sa = vma->vm_start;
1237 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1238 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1239 len = vma->vm_end - sa;
1240 len = (len < length) ? len : length;
1241 if (offset < len) {
1242 struct page *page = nth_page(rsv_schp->pages[k],
1243 offset >> PAGE_SHIFT);
1244 get_page(page); /* increment page count */
1245 vmf->page = page;
1246 return 0; /* success */
1247 }
1248 sa += len;
1249 offset -= len;
1250 }
1251
1252 return VM_FAULT_SIGBUS;
1253 }
1254
1255 static const struct vm_operations_struct sg_mmap_vm_ops = {
1256 .fault = sg_vma_fault,
1257 };
1258
1259 static int
1260 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1261 {
1262 Sg_fd *sfp;
1263 unsigned long req_sz, len, sa;
1264 Sg_scatter_hold *rsv_schp;
1265 int k, length;
1266 int ret = 0;
1267
1268 if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1269 return -ENXIO;
1270 req_sz = vma->vm_end - vma->vm_start;
1271 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1272 "sg_mmap starting, vm_start=%p, len=%d\n",
1273 (void *) vma->vm_start, (int) req_sz));
1274 if (vma->vm_pgoff)
1275 return -EINVAL; /* want no offset */
1276 rsv_schp = &sfp->reserve;
1277 mutex_lock(&sfp->f_mutex);
1278 if (req_sz > rsv_schp->bufflen) {
1279 ret = -ENOMEM; /* cannot map more than reserved buffer */
1280 goto out;
1281 }
1282
1283 sa = vma->vm_start;
1284 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1285 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1286 len = vma->vm_end - sa;
1287 len = (len < length) ? len : length;
1288 sa += len;
1289 }
1290
1291 sfp->mmap_called = 1;
1292 vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
1293 vma->vm_private_data = sfp;
1294 vma->vm_ops = &sg_mmap_vm_ops;
1295 out:
1296 mutex_unlock(&sfp->f_mutex);
1297 return ret;
1298 }
1299
1300 static void
1301 sg_rq_end_io_usercontext(struct work_struct *work)
1302 {
1303 struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1304 struct sg_fd *sfp = srp->parentfp;
1305
1306 sg_finish_rem_req(srp);
1307 sg_remove_request(sfp, srp);
1308 kref_put(&sfp->f_ref, sg_remove_sfp);
1309 }
1310
1311 /*
1312 * This function is a "bottom half" handler that is called by the mid
1313 * level when a command is completed (or has failed).
1314 */
1315 static void
1316 sg_rq_end_io(struct request *rq, blk_status_t status)
1317 {
1318 struct sg_request *srp = rq->end_io_data;
1319 struct scsi_request *req = scsi_req(rq);
1320 Sg_device *sdp;
1321 Sg_fd *sfp;
1322 unsigned long iflags;
1323 unsigned int ms;
1324 char *sense;
1325 int result, resid, done = 1;
1326
1327 if (WARN_ON(srp->done != 0))
1328 return;
1329
1330 sfp = srp->parentfp;
1331 if (WARN_ON(sfp == NULL))
1332 return;
1333
1334 sdp = sfp->parentdp;
1335 if (unlikely(atomic_read(&sdp->detaching)))
1336 pr_info("%s: device detaching\n", __func__);
1337
1338 sense = req->sense;
1339 result = req->result;
1340 resid = req->resid_len;
1341
1342 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1343 "sg_cmd_done: pack_id=%d, res=0x%x\n",
1344 srp->header.pack_id, result));
1345 srp->header.resid = resid;
1346 ms = jiffies_to_msecs(jiffies);
1347 srp->header.duration = (ms > srp->header.duration) ?
1348 (ms - srp->header.duration) : 0;
1349 if (0 != result) {
1350 struct scsi_sense_hdr sshdr;
1351
1352 srp->header.status = 0xff & result;
1353 srp->header.masked_status = status_byte(result);
1354 srp->header.msg_status = msg_byte(result);
1355 srp->header.host_status = host_byte(result);
1356 srp->header.driver_status = driver_byte(result);
1357 if ((sdp->sgdebug > 0) &&
1358 ((CHECK_CONDITION == srp->header.masked_status) ||
1359 (COMMAND_TERMINATED == srp->header.masked_status)))
1360 __scsi_print_sense(sdp->device, __func__, sense,
1361 SCSI_SENSE_BUFFERSIZE);
1362
1363 /* Following if statement is a patch supplied by Eric Youngdale */
1364 if (driver_byte(result) != 0
1365 && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1366 && !scsi_sense_is_deferred(&sshdr)
1367 && sshdr.sense_key == UNIT_ATTENTION
1368 && sdp->device->removable) {
1369 /* Detected possible disc change. Set the bit - this */
1370 /* may be used if there are filesystems using this device */
1371 sdp->device->changed = 1;
1372 }
1373 }
1374
1375 if (req->sense_len)
1376 memcpy(srp->sense_b, req->sense, SCSI_SENSE_BUFFERSIZE);
1377
1378 /* Rely on write phase to clean out srp status values, so no "else" */
1379
1380 /*
1381 * Free the request as soon as it is complete so that its resources
1382 * can be reused without waiting for userspace to read() the
1383 * result. But keep the associated bio (if any) around until
1384 * blk_rq_unmap_user() can be called from user context.
1385 */
1386 srp->rq = NULL;
1387 scsi_req_free_cmd(scsi_req(rq));
1388 blk_put_request(rq);
1389
1390 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1391 if (unlikely(srp->orphan)) {
1392 if (sfp->keep_orphan)
1393 srp->sg_io_owned = 0;
1394 else
1395 done = 0;
1396 }
1397 srp->done = done;
1398 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1399
1400 if (likely(done)) {
1401 /* Now wake up any sg_read() that is waiting for this
1402 * packet.
1403 */
1404 wake_up_interruptible(&sfp->read_wait);
1405 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1406 kref_put(&sfp->f_ref, sg_remove_sfp);
1407 } else {
1408 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1409 schedule_work(&srp->ew.work);
1410 }
1411 }
1412
1413 static const struct file_operations sg_fops = {
1414 .owner = THIS_MODULE,
1415 .read = sg_read,
1416 .write = sg_write,
1417 .poll = sg_poll,
1418 .unlocked_ioctl = sg_ioctl,
1419 #ifdef CONFIG_COMPAT
1420 .compat_ioctl = sg_compat_ioctl,
1421 #endif
1422 .open = sg_open,
1423 .mmap = sg_mmap,
1424 .release = sg_release,
1425 .fasync = sg_fasync,
1426 .llseek = no_llseek,
1427 };
1428
1429 static struct class *sg_sysfs_class;
1430
1431 static int sg_sysfs_valid = 0;
1432
1433 static Sg_device *
1434 sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1435 {
1436 struct request_queue *q = scsidp->request_queue;
1437 Sg_device *sdp;
1438 unsigned long iflags;
1439 int error;
1440 u32 k;
1441
1442 sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1443 if (!sdp) {
1444 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1445 "failure\n", __func__);
1446 return ERR_PTR(-ENOMEM);
1447 }
1448
1449 idr_preload(GFP_KERNEL);
1450 write_lock_irqsave(&sg_index_lock, iflags);
1451
1452 error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1453 if (error < 0) {
1454 if (error == -ENOSPC) {
1455 sdev_printk(KERN_WARNING, scsidp,
1456 "Unable to attach sg device type=%d, minor number exceeds %d\n",
1457 scsidp->type, SG_MAX_DEVS - 1);
1458 error = -ENODEV;
1459 } else {
1460 sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1461 "allocation Sg_device failure: %d\n",
1462 __func__, error);
1463 }
1464 goto out_unlock;
1465 }
1466 k = error;
1467
1468 SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1469 "sg_alloc: dev=%d \n", k));
1470 sprintf(disk->disk_name, "sg%d", k);
1471 disk->first_minor = k;
1472 sdp->disk = disk;
1473 sdp->device = scsidp;
1474 mutex_init(&sdp->open_rel_lock);
1475 INIT_LIST_HEAD(&sdp->sfds);
1476 init_waitqueue_head(&sdp->open_wait);
1477 atomic_set(&sdp->detaching, 0);
1478 rwlock_init(&sdp->sfd_lock);
1479 sdp->sg_tablesize = queue_max_segments(q);
1480 sdp->index = k;
1481 kref_init(&sdp->d_ref);
1482 error = 0;
1483
1484 out_unlock:
1485 write_unlock_irqrestore(&sg_index_lock, iflags);
1486 idr_preload_end();
1487
1488 if (error) {
1489 kfree(sdp);
1490 return ERR_PTR(error);
1491 }
1492 return sdp;
1493 }
1494
1495 static int
1496 sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
1497 {
1498 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1499 struct gendisk *disk;
1500 Sg_device *sdp = NULL;
1501 struct cdev * cdev = NULL;
1502 int error;
1503 unsigned long iflags;
1504
1505 disk = alloc_disk(1);
1506 if (!disk) {
1507 pr_warn("%s: alloc_disk failed\n", __func__);
1508 return -ENOMEM;
1509 }
1510 disk->major = SCSI_GENERIC_MAJOR;
1511
1512 error = -ENOMEM;
1513 cdev = cdev_alloc();
1514 if (!cdev) {
1515 pr_warn("%s: cdev_alloc failed\n", __func__);
1516 goto out;
1517 }
1518 cdev->owner = THIS_MODULE;
1519 cdev->ops = &sg_fops;
1520
1521 sdp = sg_alloc(disk, scsidp);
1522 if (IS_ERR(sdp)) {
1523 pr_warn("%s: sg_alloc failed\n", __func__);
1524 error = PTR_ERR(sdp);
1525 goto out;
1526 }
1527
1528 error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1529 if (error)
1530 goto cdev_add_err;
1531
1532 sdp->cdev = cdev;
1533 if (sg_sysfs_valid) {
1534 struct device *sg_class_member;
1535
1536 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1537 MKDEV(SCSI_GENERIC_MAJOR,
1538 sdp->index),
1539 sdp, "%s", disk->disk_name);
1540 if (IS_ERR(sg_class_member)) {
1541 pr_err("%s: device_create failed\n", __func__);
1542 error = PTR_ERR(sg_class_member);
1543 goto cdev_add_err;
1544 }
1545 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1546 &sg_class_member->kobj, "generic");
1547 if (error)
1548 pr_err("%s: unable to make symlink 'generic' back "
1549 "to sg%d\n", __func__, sdp->index);
1550 } else
1551 pr_warn("%s: sg_sys Invalid\n", __func__);
1552
1553 sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1554 "type %d\n", sdp->index, scsidp->type);
1555
1556 dev_set_drvdata(cl_dev, sdp);
1557
1558 return 0;
1559
1560 cdev_add_err:
1561 write_lock_irqsave(&sg_index_lock, iflags);
1562 idr_remove(&sg_index_idr, sdp->index);
1563 write_unlock_irqrestore(&sg_index_lock, iflags);
1564 kfree(sdp);
1565
1566 out:
1567 put_disk(disk);
1568 if (cdev)
1569 cdev_del(cdev);
1570 return error;
1571 }
1572
1573 static void
1574 sg_device_destroy(struct kref *kref)
1575 {
1576 struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1577 unsigned long flags;
1578
1579 /* CAUTION! Note that the device can still be found via idr_find()
1580 * even though the refcount is 0. Therefore, do idr_remove() BEFORE
1581 * any other cleanup.
1582 */
1583
1584 write_lock_irqsave(&sg_index_lock, flags);
1585 idr_remove(&sg_index_idr, sdp->index);
1586 write_unlock_irqrestore(&sg_index_lock, flags);
1587
1588 SCSI_LOG_TIMEOUT(3,
1589 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1590
1591 put_disk(sdp->disk);
1592 kfree(sdp);
1593 }
1594
1595 static void
1596 sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
1597 {
1598 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1599 Sg_device *sdp = dev_get_drvdata(cl_dev);
1600 unsigned long iflags;
1601 Sg_fd *sfp;
1602 int val;
1603
1604 if (!sdp)
1605 return;
1606 /* want sdp->detaching non-zero as soon as possible */
1607 val = atomic_inc_return(&sdp->detaching);
1608 if (val > 1)
1609 return; /* only want to do following once per device */
1610
1611 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1612 "%s\n", __func__));
1613
1614 read_lock_irqsave(&sdp->sfd_lock, iflags);
1615 list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1616 wake_up_interruptible_all(&sfp->read_wait);
1617 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1618 }
1619 wake_up_interruptible_all(&sdp->open_wait);
1620 read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1621
1622 sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1623 device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1624 cdev_del(sdp->cdev);
1625 sdp->cdev = NULL;
1626
1627 kref_put(&sdp->d_ref, sg_device_destroy);
1628 }
1629
1630 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1631 module_param_named(def_reserved_size, def_reserved_size, int,
1632 S_IRUGO | S_IWUSR);
1633 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1634
1635 MODULE_AUTHOR("Douglas Gilbert");
1636 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1637 MODULE_LICENSE("GPL");
1638 MODULE_VERSION(SG_VERSION_STR);
1639 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1640
1641 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1642 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1643 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1644 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1645
1646 static int __init
1647 init_sg(void)
1648 {
1649 int rc;
1650
1651 if (scatter_elem_sz < PAGE_SIZE) {
1652 scatter_elem_sz = PAGE_SIZE;
1653 scatter_elem_sz_prev = scatter_elem_sz;
1654 }
1655 if (def_reserved_size >= 0)
1656 sg_big_buff = def_reserved_size;
1657 else
1658 def_reserved_size = sg_big_buff;
1659
1660 rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1661 SG_MAX_DEVS, "sg");
1662 if (rc)
1663 return rc;
1664 sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1665 if ( IS_ERR(sg_sysfs_class) ) {
1666 rc = PTR_ERR(sg_sysfs_class);
1667 goto err_out;
1668 }
1669 sg_sysfs_valid = 1;
1670 rc = scsi_register_interface(&sg_interface);
1671 if (0 == rc) {
1672 #ifdef CONFIG_SCSI_PROC_FS
1673 sg_proc_init();
1674 #endif /* CONFIG_SCSI_PROC_FS */
1675 return 0;
1676 }
1677 class_destroy(sg_sysfs_class);
1678 err_out:
1679 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1680 return rc;
1681 }
1682
1683 static void __exit
1684 exit_sg(void)
1685 {
1686 #ifdef CONFIG_SCSI_PROC_FS
1687 remove_proc_subtree("scsi/sg", NULL);
1688 #endif /* CONFIG_SCSI_PROC_FS */
1689 scsi_unregister_interface(&sg_interface);
1690 class_destroy(sg_sysfs_class);
1691 sg_sysfs_valid = 0;
1692 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1693 SG_MAX_DEVS);
1694 idr_destroy(&sg_index_idr);
1695 }
1696
1697 static int
1698 sg_start_req(Sg_request *srp, unsigned char *cmd)
1699 {
1700 int res;
1701 struct request *rq;
1702 struct scsi_request *req;
1703 Sg_fd *sfp = srp->parentfp;
1704 sg_io_hdr_t *hp = &srp->header;
1705 int dxfer_len = (int) hp->dxfer_len;
1706 int dxfer_dir = hp->dxfer_direction;
1707 unsigned int iov_count = hp->iovec_count;
1708 Sg_scatter_hold *req_schp = &srp->data;
1709 Sg_scatter_hold *rsv_schp = &sfp->reserve;
1710 struct request_queue *q = sfp->parentdp->device->request_queue;
1711 struct rq_map_data *md, map_data;
1712 int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1713 unsigned char *long_cmdp = NULL;
1714
1715 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1716 "sg_start_req: dxfer_len=%d\n",
1717 dxfer_len));
1718
1719 if (hp->cmd_len > BLK_MAX_CDB) {
1720 long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
1721 if (!long_cmdp)
1722 return -ENOMEM;
1723 }
1724
1725 /*
1726 * NOTE
1727 *
1728 * With scsi-mq enabled, there are a fixed number of preallocated
1729 * requests equal in number to shost->can_queue. If all of the
1730 * preallocated requests are already in use, then blk_get_request()
1731 * will sleep until an active command completes, freeing up a request.
1732 * Although waiting in an asynchronous interface is less than ideal, we
1733 * do not want to use BLK_MQ_REQ_NOWAIT here because userspace might
1734 * not expect an EWOULDBLOCK from this condition.
1735 */
1736 rq = blk_get_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
1737 REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
1738 if (IS_ERR(rq)) {
1739 kfree(long_cmdp);
1740 return PTR_ERR(rq);
1741 }
1742 req = scsi_req(rq);
1743
1744 if (hp->cmd_len > BLK_MAX_CDB)
1745 req->cmd = long_cmdp;
1746 memcpy(req->cmd, cmd, hp->cmd_len);
1747 req->cmd_len = hp->cmd_len;
1748
1749 srp->rq = rq;
1750 rq->end_io_data = srp;
1751 req->retries = SG_DEFAULT_RETRIES;
1752
1753 if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1754 return 0;
1755
1756 if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1757 dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1758 !sfp->parentdp->device->host->unchecked_isa_dma &&
1759 blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1760 md = NULL;
1761 else
1762 md = &map_data;
1763
1764 if (md) {
1765 mutex_lock(&sfp->f_mutex);
1766 if (dxfer_len <= rsv_schp->bufflen &&
1767 !sfp->res_in_use) {
1768 sfp->res_in_use = 1;
1769 sg_link_reserve(sfp, srp, dxfer_len);
1770 } else if (hp->flags & SG_FLAG_MMAP_IO) {
1771 res = -EBUSY; /* sfp->res_in_use == 1 */
1772 if (dxfer_len > rsv_schp->bufflen)
1773 res = -ENOMEM;
1774 mutex_unlock(&sfp->f_mutex);
1775 return res;
1776 } else {
1777 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1778 if (res) {
1779 mutex_unlock(&sfp->f_mutex);
1780 return res;
1781 }
1782 }
1783 mutex_unlock(&sfp->f_mutex);
1784
1785 md->pages = req_schp->pages;
1786 md->page_order = req_schp->page_order;
1787 md->nr_entries = req_schp->k_use_sg;
1788 md->offset = 0;
1789 md->null_mapped = hp->dxferp ? 0 : 1;
1790 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1791 md->from_user = 1;
1792 else
1793 md->from_user = 0;
1794 }
1795
1796 if (iov_count) {
1797 struct iovec *iov = NULL;
1798 struct iov_iter i;
1799
1800 res = import_iovec(rw, hp->dxferp, iov_count, 0, &iov, &i);
1801 if (res < 0)
1802 return res;
1803
1804 iov_iter_truncate(&i, hp->dxfer_len);
1805 if (!iov_iter_count(&i)) {
1806 kfree(iov);
1807 return -EINVAL;
1808 }
1809
1810 res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
1811 kfree(iov);
1812 } else
1813 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1814 hp->dxfer_len, GFP_ATOMIC);
1815
1816 if (!res) {
1817 srp->bio = rq->bio;
1818
1819 if (!md) {
1820 req_schp->dio_in_use = 1;
1821 hp->info |= SG_INFO_DIRECT_IO;
1822 }
1823 }
1824 return res;
1825 }
1826
1827 static int
1828 sg_finish_rem_req(Sg_request *srp)
1829 {
1830 int ret = 0;
1831
1832 Sg_fd *sfp = srp->parentfp;
1833 Sg_scatter_hold *req_schp = &srp->data;
1834
1835 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1836 "sg_finish_rem_req: res_used=%d\n",
1837 (int) srp->res_used));
1838 if (srp->bio)
1839 ret = blk_rq_unmap_user(srp->bio);
1840
1841 if (srp->rq) {
1842 scsi_req_free_cmd(scsi_req(srp->rq));
1843 blk_put_request(srp->rq);
1844 }
1845
1846 if (srp->res_used)
1847 sg_unlink_reserve(sfp, srp);
1848 else
1849 sg_remove_scat(sfp, req_schp);
1850
1851 return ret;
1852 }
1853
1854 static int
1855 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1856 {
1857 int sg_bufflen = tablesize * sizeof(struct page *);
1858 gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1859
1860 schp->pages = kzalloc(sg_bufflen, gfp_flags);
1861 if (!schp->pages)
1862 return -ENOMEM;
1863 schp->sglist_len = sg_bufflen;
1864 return tablesize; /* number of scat_gath elements allocated */
1865 }
1866
1867 static int
1868 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1869 {
1870 int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1871 int sg_tablesize = sfp->parentdp->sg_tablesize;
1872 int blk_size = buff_size, order;
1873 gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
1874 struct sg_device *sdp = sfp->parentdp;
1875
1876 if (blk_size < 0)
1877 return -EFAULT;
1878 if (0 == blk_size)
1879 ++blk_size; /* don't know why */
1880 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1881 blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1882 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1883 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1884 buff_size, blk_size));
1885
1886 /* N.B. ret_sz carried into this block ... */
1887 mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1888 if (mx_sc_elems < 0)
1889 return mx_sc_elems; /* most likely -ENOMEM */
1890
1891 num = scatter_elem_sz;
1892 if (unlikely(num != scatter_elem_sz_prev)) {
1893 if (num < PAGE_SIZE) {
1894 scatter_elem_sz = PAGE_SIZE;
1895 scatter_elem_sz_prev = PAGE_SIZE;
1896 } else
1897 scatter_elem_sz_prev = num;
1898 }
1899
1900 if (sdp->device->host->unchecked_isa_dma)
1901 gfp_mask |= GFP_DMA;
1902
1903 order = get_order(num);
1904 retry:
1905 ret_sz = 1 << (PAGE_SHIFT + order);
1906
1907 for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1908 k++, rem_sz -= ret_sz) {
1909
1910 num = (rem_sz > scatter_elem_sz_prev) ?
1911 scatter_elem_sz_prev : rem_sz;
1912
1913 schp->pages[k] = alloc_pages(gfp_mask, order);
1914 if (!schp->pages[k])
1915 goto out;
1916
1917 if (num == scatter_elem_sz_prev) {
1918 if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1919 scatter_elem_sz = ret_sz;
1920 scatter_elem_sz_prev = ret_sz;
1921 }
1922 }
1923
1924 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1925 "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1926 k, num, ret_sz));
1927 } /* end of for loop */
1928
1929 schp->page_order = order;
1930 schp->k_use_sg = k;
1931 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1932 "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1933 k, rem_sz));
1934
1935 schp->bufflen = blk_size;
1936 if (rem_sz > 0) /* must have failed */
1937 return -ENOMEM;
1938 return 0;
1939 out:
1940 for (i = 0; i < k; i++)
1941 __free_pages(schp->pages[i], order);
1942
1943 if (--order >= 0)
1944 goto retry;
1945
1946 return -ENOMEM;
1947 }
1948
1949 static void
1950 sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1951 {
1952 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1953 "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1954 if (schp->pages && schp->sglist_len > 0) {
1955 if (!schp->dio_in_use) {
1956 int k;
1957
1958 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1959 SCSI_LOG_TIMEOUT(5,
1960 sg_printk(KERN_INFO, sfp->parentdp,
1961 "sg_remove_scat: k=%d, pg=0x%p\n",
1962 k, schp->pages[k]));
1963 __free_pages(schp->pages[k], schp->page_order);
1964 }
1965
1966 kfree(schp->pages);
1967 }
1968 }
1969 memset(schp, 0, sizeof (*schp));
1970 }
1971
1972 static int
1973 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1974 {
1975 Sg_scatter_hold *schp = &srp->data;
1976 int k, num;
1977
1978 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1979 "sg_read_oxfer: num_read_xfer=%d\n",
1980 num_read_xfer));
1981 if ((!outp) || (num_read_xfer <= 0))
1982 return 0;
1983
1984 num = 1 << (PAGE_SHIFT + schp->page_order);
1985 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1986 if (num > num_read_xfer) {
1987 if (__copy_to_user(outp, page_address(schp->pages[k]),
1988 num_read_xfer))
1989 return -EFAULT;
1990 break;
1991 } else {
1992 if (__copy_to_user(outp, page_address(schp->pages[k]),
1993 num))
1994 return -EFAULT;
1995 num_read_xfer -= num;
1996 if (num_read_xfer <= 0)
1997 break;
1998 outp += num;
1999 }
2000 }
2001
2002 return 0;
2003 }
2004
2005 static void
2006 sg_build_reserve(Sg_fd * sfp, int req_size)
2007 {
2008 Sg_scatter_hold *schp = &sfp->reserve;
2009
2010 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2011 "sg_build_reserve: req_size=%d\n", req_size));
2012 do {
2013 if (req_size < PAGE_SIZE)
2014 req_size = PAGE_SIZE;
2015 if (0 == sg_build_indirect(schp, sfp, req_size))
2016 return;
2017 else
2018 sg_remove_scat(sfp, schp);
2019 req_size >>= 1; /* divide by 2 */
2020 } while (req_size > (PAGE_SIZE / 2));
2021 }
2022
2023 static void
2024 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2025 {
2026 Sg_scatter_hold *req_schp = &srp->data;
2027 Sg_scatter_hold *rsv_schp = &sfp->reserve;
2028 int k, num, rem;
2029
2030 srp->res_used = 1;
2031 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2032 "sg_link_reserve: size=%d\n", size));
2033 rem = size;
2034
2035 num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
2036 for (k = 0; k < rsv_schp->k_use_sg; k++) {
2037 if (rem <= num) {
2038 req_schp->k_use_sg = k + 1;
2039 req_schp->sglist_len = rsv_schp->sglist_len;
2040 req_schp->pages = rsv_schp->pages;
2041
2042 req_schp->bufflen = size;
2043 req_schp->page_order = rsv_schp->page_order;
2044 break;
2045 } else
2046 rem -= num;
2047 }
2048
2049 if (k >= rsv_schp->k_use_sg)
2050 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2051 "sg_link_reserve: BAD size\n"));
2052 }
2053
2054 static void
2055 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2056 {
2057 Sg_scatter_hold *req_schp = &srp->data;
2058
2059 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2060 "sg_unlink_reserve: req->k_use_sg=%d\n",
2061 (int) req_schp->k_use_sg));
2062 req_schp->k_use_sg = 0;
2063 req_schp->bufflen = 0;
2064 req_schp->pages = NULL;
2065 req_schp->page_order = 0;
2066 req_schp->sglist_len = 0;
2067 srp->res_used = 0;
2068 /* Called without mutex lock to avoid deadlock */
2069 sfp->res_in_use = 0;
2070 }
2071
2072 static Sg_request *
2073 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2074 {
2075 Sg_request *resp;
2076 unsigned long iflags;
2077
2078 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2079 list_for_each_entry(resp, &sfp->rq_list, entry) {
2080 /* look for requests that are ready + not SG_IO owned */
2081 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2082 ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2083 resp->done = 2; /* guard against other readers */
2084 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2085 return resp;
2086 }
2087 }
2088 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2089 return NULL;
2090 }
2091
2092 /* always adds to end of list */
2093 static Sg_request *
2094 sg_add_request(Sg_fd * sfp)
2095 {
2096 int k;
2097 unsigned long iflags;
2098 Sg_request *rp = sfp->req_arr;
2099
2100 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2101 if (!list_empty(&sfp->rq_list)) {
2102 if (!sfp->cmd_q)
2103 goto out_unlock;
2104
2105 for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2106 if (!rp->parentfp)
2107 break;
2108 }
2109 if (k >= SG_MAX_QUEUE)
2110 goto out_unlock;
2111 }
2112 memset(rp, 0, sizeof (Sg_request));
2113 rp->parentfp = sfp;
2114 rp->header.duration = jiffies_to_msecs(jiffies);
2115 list_add_tail(&rp->entry, &sfp->rq_list);
2116 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2117 return rp;
2118 out_unlock:
2119 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2120 return NULL;
2121 }
2122
2123 /* Return of 1 for found; 0 for not found */
2124 static int
2125 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2126 {
2127 unsigned long iflags;
2128 int res = 0;
2129
2130 if (!sfp || !srp || list_empty(&sfp->rq_list))
2131 return res;
2132 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2133 if (!list_empty(&srp->entry)) {
2134 list_del(&srp->entry);
2135 srp->parentfp = NULL;
2136 res = 1;
2137 }
2138 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2139 return res;
2140 }
2141
2142 static Sg_fd *
2143 sg_add_sfp(Sg_device * sdp)
2144 {
2145 Sg_fd *sfp;
2146 unsigned long iflags;
2147 int bufflen;
2148
2149 sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2150 if (!sfp)
2151 return ERR_PTR(-ENOMEM);
2152
2153 init_waitqueue_head(&sfp->read_wait);
2154 rwlock_init(&sfp->rq_list_lock);
2155 INIT_LIST_HEAD(&sfp->rq_list);
2156 kref_init(&sfp->f_ref);
2157 mutex_init(&sfp->f_mutex);
2158 sfp->timeout = SG_DEFAULT_TIMEOUT;
2159 sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2160 sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2161 sfp->cmd_q = SG_DEF_COMMAND_Q;
2162 sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2163 sfp->parentdp = sdp;
2164 write_lock_irqsave(&sdp->sfd_lock, iflags);
2165 if (atomic_read(&sdp->detaching)) {
2166 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2167 kfree(sfp);
2168 return ERR_PTR(-ENODEV);
2169 }
2170 list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2171 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2172 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2173 "sg_add_sfp: sfp=0x%p\n", sfp));
2174 if (unlikely(sg_big_buff != def_reserved_size))
2175 sg_big_buff = def_reserved_size;
2176
2177 bufflen = min_t(int, sg_big_buff,
2178 max_sectors_bytes(sdp->device->request_queue));
2179 sg_build_reserve(sfp, bufflen);
2180 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2181 "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2182 sfp->reserve.bufflen,
2183 sfp->reserve.k_use_sg));
2184
2185 kref_get(&sdp->d_ref);
2186 __module_get(THIS_MODULE);
2187 return sfp;
2188 }
2189
2190 static void
2191 sg_remove_sfp_usercontext(struct work_struct *work)
2192 {
2193 struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2194 struct sg_device *sdp = sfp->parentdp;
2195 Sg_request *srp;
2196 unsigned long iflags;
2197
2198 /* Cleanup any responses which were never read(). */
2199 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2200 while (!list_empty(&sfp->rq_list)) {
2201 srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2202 sg_finish_rem_req(srp);
2203 list_del(&srp->entry);
2204 srp->parentfp = NULL;
2205 }
2206 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2207
2208 if (sfp->reserve.bufflen > 0) {
2209 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2210 "sg_remove_sfp: bufflen=%d, k_use_sg=%d\n",
2211 (int) sfp->reserve.bufflen,
2212 (int) sfp->reserve.k_use_sg));
2213 sg_remove_scat(sfp, &sfp->reserve);
2214 }
2215
2216 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2217 "sg_remove_sfp: sfp=0x%p\n", sfp));
2218 kfree(sfp);
2219
2220 scsi_device_put(sdp->device);
2221 kref_put(&sdp->d_ref, sg_device_destroy);
2222 module_put(THIS_MODULE);
2223 }
2224
2225 static void
2226 sg_remove_sfp(struct kref *kref)
2227 {
2228 struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2229 struct sg_device *sdp = sfp->parentdp;
2230 unsigned long iflags;
2231
2232 write_lock_irqsave(&sdp->sfd_lock, iflags);
2233 list_del(&sfp->sfd_siblings);
2234 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2235
2236 INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2237 schedule_work(&sfp->ew.work);
2238 }
2239
2240 #ifdef CONFIG_SCSI_PROC_FS
2241 static int
2242 sg_idr_max_id(int id, void *p, void *data)
2243 {
2244 int *k = data;
2245
2246 if (*k < id)
2247 *k = id;
2248
2249 return 0;
2250 }
2251
2252 static int
2253 sg_last_dev(void)
2254 {
2255 int k = -1;
2256 unsigned long iflags;
2257
2258 read_lock_irqsave(&sg_index_lock, iflags);
2259 idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2260 read_unlock_irqrestore(&sg_index_lock, iflags);
2261 return k + 1; /* origin 1 */
2262 }
2263 #endif
2264
2265 /* must be called with sg_index_lock held */
2266 static Sg_device *sg_lookup_dev(int dev)
2267 {
2268 return idr_find(&sg_index_idr, dev);
2269 }
2270
2271 static Sg_device *
2272 sg_get_dev(int dev)
2273 {
2274 struct sg_device *sdp;
2275 unsigned long flags;
2276
2277 read_lock_irqsave(&sg_index_lock, flags);
2278 sdp = sg_lookup_dev(dev);
2279 if (!sdp)
2280 sdp = ERR_PTR(-ENXIO);
2281 else if (atomic_read(&sdp->detaching)) {
2282 /* If sdp->detaching, then the refcount may already be 0, in
2283 * which case it would be a bug to do kref_get().
2284 */
2285 sdp = ERR_PTR(-ENODEV);
2286 } else
2287 kref_get(&sdp->d_ref);
2288 read_unlock_irqrestore(&sg_index_lock, flags);
2289
2290 return sdp;
2291 }
2292
2293 #ifdef CONFIG_SCSI_PROC_FS
2294 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2295
2296 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2297 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2298 size_t count, loff_t *off);
2299 static const struct file_operations adio_fops = {
2300 .owner = THIS_MODULE,
2301 .open = sg_proc_single_open_adio,
2302 .read = seq_read,
2303 .llseek = seq_lseek,
2304 .write = sg_proc_write_adio,
2305 .release = single_release,
2306 };
2307
2308 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2309 static ssize_t sg_proc_write_dressz(struct file *filp,
2310 const char __user *buffer, size_t count, loff_t *off);
2311 static const struct file_operations dressz_fops = {
2312 .owner = THIS_MODULE,
2313 .open = sg_proc_single_open_dressz,
2314 .read = seq_read,
2315 .llseek = seq_lseek,
2316 .write = sg_proc_write_dressz,
2317 .release = single_release,
2318 };
2319
2320 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2321 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2322 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2323 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2324 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2325 static void dev_seq_stop(struct seq_file *s, void *v);
2326 static const struct seq_operations dev_seq_ops = {
2327 .start = dev_seq_start,
2328 .next = dev_seq_next,
2329 .stop = dev_seq_stop,
2330 .show = sg_proc_seq_show_dev,
2331 };
2332
2333 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2334 static const struct seq_operations devstrs_seq_ops = {
2335 .start = dev_seq_start,
2336 .next = dev_seq_next,
2337 .stop = dev_seq_stop,
2338 .show = sg_proc_seq_show_devstrs,
2339 };
2340
2341 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2342 static const struct seq_operations debug_seq_ops = {
2343 .start = dev_seq_start,
2344 .next = dev_seq_next,
2345 .stop = dev_seq_stop,
2346 .show = sg_proc_seq_show_debug,
2347 };
2348
2349 static int
2350 sg_proc_init(void)
2351 {
2352 struct proc_dir_entry *p;
2353
2354 p = proc_mkdir("scsi/sg", NULL);
2355 if (!p)
2356 return 1;
2357
2358 proc_create("allow_dio", S_IRUGO | S_IWUSR, p, &adio_fops);
2359 proc_create_seq("debug", S_IRUGO, p, &debug_seq_ops);
2360 proc_create("def_reserved_size", S_IRUGO | S_IWUSR, p, &dressz_fops);
2361 proc_create_single("device_hdr", S_IRUGO, p, sg_proc_seq_show_devhdr);
2362 proc_create_seq("devices", S_IRUGO, p, &dev_seq_ops);
2363 proc_create_seq("device_strs", S_IRUGO, p, &devstrs_seq_ops);
2364 proc_create_single("version", S_IRUGO, p, sg_proc_seq_show_version);
2365 return 0;
2366 }
2367
2368
2369 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2370 {
2371 seq_printf(s, "%d\n", *((int *)s->private));
2372 return 0;
2373 }
2374
2375 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2376 {
2377 return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2378 }
2379
2380 static ssize_t
2381 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2382 size_t count, loff_t *off)
2383 {
2384 int err;
2385 unsigned long num;
2386
2387 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2388 return -EACCES;
2389 err = kstrtoul_from_user(buffer, count, 0, &num);
2390 if (err)
2391 return err;
2392 sg_allow_dio = num ? 1 : 0;
2393 return count;
2394 }
2395
2396 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2397 {
2398 return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2399 }
2400
2401 static ssize_t
2402 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2403 size_t count, loff_t *off)
2404 {
2405 int err;
2406 unsigned long k = ULONG_MAX;
2407
2408 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2409 return -EACCES;
2410
2411 err = kstrtoul_from_user(buffer, count, 0, &k);
2412 if (err)
2413 return err;
2414 if (k <= 1048576) { /* limit "big buff" to 1 MB */
2415 sg_big_buff = k;
2416 return count;
2417 }
2418 return -ERANGE;
2419 }
2420
2421 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2422 {
2423 seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2424 sg_version_date);
2425 return 0;
2426 }
2427
2428 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2429 {
2430 seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2431 return 0;
2432 }
2433
2434 struct sg_proc_deviter {
2435 loff_t index;
2436 size_t max;
2437 };
2438
2439 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2440 {
2441 struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2442
2443 s->private = it;
2444 if (! it)
2445 return NULL;
2446
2447 it->index = *pos;
2448 it->max = sg_last_dev();
2449 if (it->index >= it->max)
2450 return NULL;
2451 return it;
2452 }
2453
2454 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2455 {
2456 struct sg_proc_deviter * it = s->private;
2457
2458 *pos = ++it->index;
2459 return (it->index < it->max) ? it : NULL;
2460 }
2461
2462 static void dev_seq_stop(struct seq_file *s, void *v)
2463 {
2464 kfree(s->private);
2465 }
2466
2467 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2468 {
2469 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2470 Sg_device *sdp;
2471 struct scsi_device *scsidp;
2472 unsigned long iflags;
2473
2474 read_lock_irqsave(&sg_index_lock, iflags);
2475 sdp = it ? sg_lookup_dev(it->index) : NULL;
2476 if ((NULL == sdp) || (NULL == sdp->device) ||
2477 (atomic_read(&sdp->detaching)))
2478 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2479 else {
2480 scsidp = sdp->device;
2481 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2482 scsidp->host->host_no, scsidp->channel,
2483 scsidp->id, scsidp->lun, (int) scsidp->type,
2484 1,
2485 (int) scsidp->queue_depth,
2486 (int) atomic_read(&scsidp->device_busy),
2487 (int) scsi_device_online(scsidp));
2488 }
2489 read_unlock_irqrestore(&sg_index_lock, iflags);
2490 return 0;
2491 }
2492
2493 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2494 {
2495 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2496 Sg_device *sdp;
2497 struct scsi_device *scsidp;
2498 unsigned long iflags;
2499
2500 read_lock_irqsave(&sg_index_lock, iflags);
2501 sdp = it ? sg_lookup_dev(it->index) : NULL;
2502 scsidp = sdp ? sdp->device : NULL;
2503 if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2504 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2505 scsidp->vendor, scsidp->model, scsidp->rev);
2506 else
2507 seq_puts(s, "<no active device>\n");
2508 read_unlock_irqrestore(&sg_index_lock, iflags);
2509 return 0;
2510 }
2511
2512 /* must be called while holding sg_index_lock */
2513 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2514 {
2515 int k, new_interface, blen, usg;
2516 Sg_request *srp;
2517 Sg_fd *fp;
2518 const sg_io_hdr_t *hp;
2519 const char * cp;
2520 unsigned int ms;
2521
2522 k = 0;
2523 list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2524 k++;
2525 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2526 seq_printf(s, " FD(%d): timeout=%dms bufflen=%d "
2527 "(res)sgat=%d low_dma=%d\n", k,
2528 jiffies_to_msecs(fp->timeout),
2529 fp->reserve.bufflen,
2530 (int) fp->reserve.k_use_sg,
2531 (int) sdp->device->host->unchecked_isa_dma);
2532 seq_printf(s, " cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2533 (int) fp->cmd_q, (int) fp->force_packid,
2534 (int) fp->keep_orphan);
2535 list_for_each_entry(srp, &fp->rq_list, entry) {
2536 hp = &srp->header;
2537 new_interface = (hp->interface_id == '\0') ? 0 : 1;
2538 if (srp->res_used) {
2539 if (new_interface &&
2540 (SG_FLAG_MMAP_IO & hp->flags))
2541 cp = " mmap>> ";
2542 else
2543 cp = " rb>> ";
2544 } else {
2545 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2546 cp = " dio>> ";
2547 else
2548 cp = " ";
2549 }
2550 seq_puts(s, cp);
2551 blen = srp->data.bufflen;
2552 usg = srp->data.k_use_sg;
2553 seq_puts(s, srp->done ?
2554 ((1 == srp->done) ? "rcv:" : "fin:")
2555 : "act:");
2556 seq_printf(s, " id=%d blen=%d",
2557 srp->header.pack_id, blen);
2558 if (srp->done)
2559 seq_printf(s, " dur=%d", hp->duration);
2560 else {
2561 ms = jiffies_to_msecs(jiffies);
2562 seq_printf(s, " t_o/elap=%d/%d",
2563 (new_interface ? hp->timeout :
2564 jiffies_to_msecs(fp->timeout)),
2565 (ms > hp->duration ? ms - hp->duration : 0));
2566 }
2567 seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2568 (int) srp->data.cmd_opcode);
2569 }
2570 if (list_empty(&fp->rq_list))
2571 seq_puts(s, " No requests active\n");
2572 read_unlock(&fp->rq_list_lock);
2573 }
2574 }
2575
2576 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2577 {
2578 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2579 Sg_device *sdp;
2580 unsigned long iflags;
2581
2582 if (it && (0 == it->index))
2583 seq_printf(s, "max_active_device=%d def_reserved_size=%d\n",
2584 (int)it->max, sg_big_buff);
2585
2586 read_lock_irqsave(&sg_index_lock, iflags);
2587 sdp = it ? sg_lookup_dev(it->index) : NULL;
2588 if (NULL == sdp)
2589 goto skip;
2590 read_lock(&sdp->sfd_lock);
2591 if (!list_empty(&sdp->sfds)) {
2592 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2593 if (atomic_read(&sdp->detaching))
2594 seq_puts(s, "detaching pending close ");
2595 else if (sdp->device) {
2596 struct scsi_device *scsidp = sdp->device;
2597
2598 seq_printf(s, "%d:%d:%d:%llu em=%d",
2599 scsidp->host->host_no,
2600 scsidp->channel, scsidp->id,
2601 scsidp->lun,
2602 scsidp->host->hostt->emulated);
2603 }
2604 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2605 sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2606 sg_proc_debug_helper(s, sdp);
2607 }
2608 read_unlock(&sdp->sfd_lock);
2609 skip:
2610 read_unlock_irqrestore(&sg_index_lock, iflags);
2611 return 0;
2612 }
2613
2614 #endif /* CONFIG_SCSI_PROC_FS */
2615
2616 module_init(init_sg);
2617 module_exit(exit_sg);
Linux with added FPC-III support