1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * History:
4 * Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
5 * to allow user process control of SCSI devices.
6 * Development Sponsored by Killy Corp. NY NY
7 *
8 * Original driver (sg.c):
9 * Copyright (C) 1992 Lawrence Foard
10 * Version 2 and 3 extensions to driver:
11 * Copyright (C) 1998 - 2014 Douglas Gilbert
12 */
13
14static int sg_version_num = 30536; /* 2 digits for each component */
15#define SG_VERSION_STR "3.5.36"
16
17/*
18 * D. P. Gilbert (dgilbert@interlog.com), notes:
19 * - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
20 * the kernel/module needs to be built with CONFIG_SCSI_LOGGING
21 * (otherwise the macros compile to empty statements).
22 *
23 */
24#include <linux/module.h>
25
26#include <linux/fs.h>
27#include <linux/kernel.h>
28#include <linux/sched.h>
29#include <linux/string.h>
30#include <linux/mm.h>
31#include <linux/errno.h>
32#include <linux/mtio.h>
33#include <linux/ioctl.h>
34#include <linux/major.h>
35#include <linux/slab.h>
36#include <linux/fcntl.h>
37#include <linux/init.h>
38#include <linux/poll.h>
39#include <linux/moduleparam.h>
40#include <linux/cdev.h>
41#include <linux/idr.h>
42#include <linux/seq_file.h>
43#include <linux/blkdev.h>
44#include <linux/delay.h>
45#include <linux/blktrace_api.h>
46#include <linux/mutex.h>
47#include <linux/atomic.h>
48#include <linux/ratelimit.h>
49#include <linux/uio.h>
50#include <linux/cred.h> /* for sg_check_file_access() */
51
52#include <scsi/scsi.h>
53#include <scsi/scsi_cmnd.h>
54#include <scsi/scsi_dbg.h>
55#include <scsi/scsi_device.h>
56#include <scsi/scsi_driver.h>
57#include <scsi/scsi_eh.h>
58#include <scsi/scsi_host.h>
59#include <scsi/scsi_ioctl.h>
60#include <scsi/scsi_tcq.h>
61#include <scsi/sg.h>
62
63#include "scsi_logging.h"
64
65#ifdef CONFIG_SCSI_PROC_FS
66#include <linux/proc_fs.h>
67static char *sg_version_date = "20140603";
68
69static int sg_proc_init(void);
70#endif
71
72#define SG_ALLOW_DIO_DEF 0
73
74#define SG_MAX_DEVS (1 << MINORBITS)
75
76/* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
77 * of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater
78 * than 16 bytes are "variable length" whose length is a multiple of 4
79 */
80#define SG_MAX_CDB_SIZE 252
81
82#define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
83
84static int sg_big_buff = SG_DEF_RESERVED_SIZE;
85/* N.B. This variable is readable and writeable via
86 /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
87 of this size (or less if there is not enough memory) will be reserved
88 for use by this file descriptor. [Deprecated usage: this variable is also
89 readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
90 the kernel (i.e. it is not a module).] */
91static int def_reserved_size = -1; /* picks up init parameter */
92static int sg_allow_dio = SG_ALLOW_DIO_DEF;
93
94static int scatter_elem_sz = SG_SCATTER_SZ;
95static int scatter_elem_sz_prev = SG_SCATTER_SZ;
96
97#define SG_SECTOR_SZ 512
98
99static int sg_add_device(struct device *);
100static void sg_remove_device(struct device *);
101
102static DEFINE_IDR(sg_index_idr);
103static DEFINE_RWLOCK(sg_index_lock); /* Also used to lock
104 file descriptor list for device */
105
106static struct class_interface sg_interface = {
107 .add_dev = sg_add_device,
108 .remove_dev = sg_remove_device,
109};
110
111typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
112 unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
113 unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
114 unsigned bufflen; /* Size of (aggregate) data buffer */
115 struct page **pages;
116 int page_order;
117 char dio_in_use; /* 0->indirect IO (or mmap), 1->dio */
118 unsigned char cmd_opcode; /* first byte of command */
119} Sg_scatter_hold;
120
121struct sg_device; /* forward declarations */
122struct sg_fd;
123
124typedef struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */
125 struct list_head entry; /* list entry */
126 struct sg_fd *parentfp; /* NULL -> not in use */
127 Sg_scatter_hold data; /* hold buffer, perhaps scatter list */
128 sg_io_hdr_t header; /* scsi command+info, see <scsi/sg.h> */
129 unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
130 char res_used; /* 1 -> using reserve buffer, 0 -> not ... */
131 char orphan; /* 1 -> drop on sight, 0 -> normal */
132 char sg_io_owned; /* 1 -> packet belongs to SG_IO */
133 /* done protected by rq_list_lock */
134 char done; /* 0->before bh, 1->before read, 2->read */
135 struct request *rq;
136 struct bio *bio;
137 struct execute_work ew;
138} Sg_request;
139
140typedef struct sg_fd { /* holds the state of a file descriptor */
141 struct list_head sfd_siblings; /* protected by device's sfd_lock */
142 struct sg_device *parentdp; /* owning device */
143 wait_queue_head_t read_wait; /* queue read until command done */
144 rwlock_t rq_list_lock; /* protect access to list in req_arr */
145 struct mutex f_mutex; /* protect against changes in this fd */
146 int timeout; /* defaults to SG_DEFAULT_TIMEOUT */
147 int timeout_user; /* defaults to SG_DEFAULT_TIMEOUT_USER */
148 Sg_scatter_hold reserve; /* buffer held for this file descriptor */
149 struct list_head rq_list; /* head of request list */
150 struct fasync_struct *async_qp; /* used by asynchronous notification */
151 Sg_request req_arr[SG_MAX_QUEUE]; /* used as singly-linked list */
152 char force_packid; /* 1 -> pack_id input to read(), 0 -> ignored */
153 char cmd_q; /* 1 -> allow command queuing, 0 -> don't */
154 unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */
155 char keep_orphan; /* 0 -> drop orphan (def), 1 -> keep for read() */
156 char mmap_called; /* 0 -> mmap() never called on this fd */
157 char res_in_use; /* 1 -> 'reserve' array in use */
158 struct kref f_ref;
159 struct execute_work ew;
160} Sg_fd;
161
162typedef struct sg_device { /* holds the state of each scsi generic device */
163 struct scsi_device *device;
164 wait_queue_head_t open_wait; /* queue open() when O_EXCL present */
165 struct mutex open_rel_lock; /* held when in open() or release() */
166 int sg_tablesize; /* adapter's max scatter-gather table size */
167 u32 index; /* device index number */
168 struct list_head sfds;
169 rwlock_t sfd_lock; /* protect access to sfd list */
170 atomic_t detaching; /* 0->device usable, 1->device detaching */
171 bool exclude; /* 1->open(O_EXCL) succeeded and is active */
172 int open_cnt; /* count of opens (perhaps < num(sfds) ) */
173 char sgdebug; /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
174 char name[DISK_NAME_LEN];
175 struct cdev * cdev; /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
176 struct kref d_ref;
177} Sg_device;
178
179/* tasklet or soft irq callback */
180static enum rq_end_io_ret sg_rq_end_io(struct request *rq, blk_status_t status);
181static int sg_start_req(Sg_request *srp, unsigned char *cmd);
182static int sg_finish_rem_req(Sg_request * srp);
183static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
184static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
185 Sg_request * srp);
186static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
187 const char __user *buf, size_t count, int blocking,
188 int read_only, int sg_io_owned, Sg_request **o_srp);
189static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
190 unsigned char *cmnd, int timeout, int blocking);
191static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
192static void sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp);
193static void sg_build_reserve(Sg_fd * sfp, int req_size);
194static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
195static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
196static Sg_fd *sg_add_sfp(Sg_device * sdp);
197static void sg_remove_sfp(struct kref *);
198static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id, bool *busy);
199static Sg_request *sg_add_request(Sg_fd * sfp);
200static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
201static Sg_device *sg_get_dev(int dev);
202static void sg_device_destroy(struct kref *kref);
203
204#define SZ_SG_HEADER sizeof(struct sg_header)
205#define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
206#define SZ_SG_IOVEC sizeof(sg_iovec_t)
207#define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
208
209#define sg_printk(prefix, sdp, fmt, a...) \
210 sdev_prefix_printk(prefix, (sdp)->device, (sdp)->name, fmt, ##a)
211
212/*
213 * The SCSI interfaces that use read() and write() as an asynchronous variant of
214 * ioctl(..., SG_IO, ...) are fundamentally unsafe, since there are lots of ways
215 * to trigger read() and write() calls from various contexts with elevated
216 * privileges. This can lead to kernel memory corruption (e.g. if these
217 * interfaces are called through splice()) and privilege escalation inside
218 * userspace (e.g. if a process with access to such a device passes a file
219 * descriptor to a SUID binary as stdin/stdout/stderr).
220 *
221 * This function provides protection for the legacy API by restricting the
222 * calling context.
223 */
224static int sg_check_file_access(struct file *filp, const char *caller)
225{
226 if (filp->f_cred != current_real_cred()) {
227 pr_err_once("%s: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
228 caller, task_tgid_vnr(current), current->comm);
229 return -EPERM;
230 }
231 return 0;
232}
233
234static int sg_allow_access(struct file *filp, unsigned char *cmd)
235{
236 struct sg_fd *sfp = filp->private_data;
237
238 if (sfp->parentdp->device->type == TYPE_SCANNER)
239 return 0;
240 if (!scsi_cmd_allowed(cmd, open_for_write: filp->f_mode & FMODE_WRITE))
241 return -EPERM;
242 return 0;
243}
244
245static int
246open_wait(Sg_device *sdp, int flags)
247{
248 int retval = 0;
249
250 if (flags & O_EXCL) {
251 while (sdp->open_cnt > 0) {
252 mutex_unlock(lock: &sdp->open_rel_lock);
253 retval = wait_event_interruptible(sdp->open_wait,
254 (atomic_read(&sdp->detaching) ||
255 !sdp->open_cnt));
256 mutex_lock(lock: &sdp->open_rel_lock);
257
258 if (retval) /* -ERESTARTSYS */
259 return retval;
260 if (atomic_read(v: &sdp->detaching))
261 return -ENODEV;
262 }
263 } else {
264 while (sdp->exclude) {
265 mutex_unlock(lock: &sdp->open_rel_lock);
266 retval = wait_event_interruptible(sdp->open_wait,
267 (atomic_read(&sdp->detaching) ||
268 !sdp->exclude));
269 mutex_lock(lock: &sdp->open_rel_lock);
270
271 if (retval) /* -ERESTARTSYS */
272 return retval;
273 if (atomic_read(v: &sdp->detaching))
274 return -ENODEV;
275 }
276 }
277
278 return retval;
279}
280
281/* Returns 0 on success, else a negated errno value */
282static int
283sg_open(struct inode *inode, struct file *filp)
284{
285 int dev = iminor(inode);
286 int flags = filp->f_flags;
287 struct request_queue *q;
288 struct scsi_device *device;
289 Sg_device *sdp;
290 Sg_fd *sfp;
291 int retval;
292
293 nonseekable_open(inode, filp);
294 if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
295 return -EPERM; /* Can't lock it with read only access */
296 sdp = sg_get_dev(dev);
297 if (IS_ERR(ptr: sdp))
298 return PTR_ERR(ptr: sdp);
299
300 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
301 "sg_open: flags=0x%x\n", flags));
302
303 /* This driver's module count bumped by fops_get in <linux/fs.h> */
304 /* Prevent the device driver from vanishing while we sleep */
305 device = sdp->device;
306 retval = scsi_device_get(device);
307 if (retval)
308 goto sg_put;
309
310 /* scsi_block_when_processing_errors() may block so bypass
311 * check if O_NONBLOCK. Permits SCSI commands to be issued
312 * during error recovery. Tread carefully. */
313 if (!((flags & O_NONBLOCK) ||
314 scsi_block_when_processing_errors(device))) {
315 retval = -ENXIO;
316 /* we are in error recovery for this device */
317 goto sdp_put;
318 }
319
320 mutex_lock(lock: &sdp->open_rel_lock);
321 if (flags & O_NONBLOCK) {
322 if (flags & O_EXCL) {
323 if (sdp->open_cnt > 0) {
324 retval = -EBUSY;
325 goto error_mutex_locked;
326 }
327 } else {
328 if (sdp->exclude) {
329 retval = -EBUSY;
330 goto error_mutex_locked;
331 }
332 }
333 } else {
334 retval = open_wait(sdp, flags);
335 if (retval) /* -ERESTARTSYS or -ENODEV */
336 goto error_mutex_locked;
337 }
338
339 /* N.B. at this point we are holding the open_rel_lock */
340 if (flags & O_EXCL)
341 sdp->exclude = true;
342
343 if (sdp->open_cnt < 1) { /* no existing opens */
344 sdp->sgdebug = 0;
345 q = device->request_queue;
346 sdp->sg_tablesize = queue_max_segments(q);
347 }
348 sfp = sg_add_sfp(sdp);
349 if (IS_ERR(ptr: sfp)) {
350 retval = PTR_ERR(ptr: sfp);
351 goto out_undo;
352 }
353
354 filp->private_data = sfp;
355 sdp->open_cnt++;
356 mutex_unlock(lock: &sdp->open_rel_lock);
357
358 retval = 0;
359sg_put:
360 kref_put(kref: &sdp->d_ref, release: sg_device_destroy);
361 return retval;
362
363out_undo:
364 if (flags & O_EXCL) {
365 sdp->exclude = false; /* undo if error */
366 wake_up_interruptible(&sdp->open_wait);
367 }
368error_mutex_locked:
369 mutex_unlock(lock: &sdp->open_rel_lock);
370sdp_put:
371 kref_put(kref: &sdp->d_ref, release: sg_device_destroy);
372 scsi_device_put(device);
373 return retval;
374}
375
376/* Release resources associated with a successful sg_open()
377 * Returns 0 on success, else a negated errno value */
378static int
379sg_release(struct inode *inode, struct file *filp)
380{
381 Sg_device *sdp;
382 Sg_fd *sfp;
383
384 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
385 return -ENXIO;
386 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
387
388 mutex_lock(lock: &sdp->open_rel_lock);
389 sdp->open_cnt--;
390
391 /* possibly many open()s waiting on exlude clearing, start many;
392 * only open(O_EXCL)s wait on 0==open_cnt so only start one */
393 if (sdp->exclude) {
394 sdp->exclude = false;
395 wake_up_interruptible_all(&sdp->open_wait);
396 } else if (0 == sdp->open_cnt) {
397 wake_up_interruptible(&sdp->open_wait);
398 }
399 mutex_unlock(lock: &sdp->open_rel_lock);
400 kref_put(kref: &sfp->f_ref, release: sg_remove_sfp);
401 return 0;
402}
403
404static int get_sg_io_pack_id(int *pack_id, void __user *buf, size_t count)
405{
406 struct sg_header __user *old_hdr = buf;
407 int reply_len;
408
409 if (count >= SZ_SG_HEADER) {
410 /* negative reply_len means v3 format, otherwise v1/v2 */
411 if (get_user(reply_len, &old_hdr->reply_len))
412 return -EFAULT;
413
414 if (reply_len >= 0)
415 return get_user(*pack_id, &old_hdr->pack_id);
416
417 if (in_compat_syscall() &&
418 count >= sizeof(struct compat_sg_io_hdr)) {
419 struct compat_sg_io_hdr __user *hp = buf;
420
421 return get_user(*pack_id, &hp->pack_id);
422 }
423
424 if (count >= sizeof(struct sg_io_hdr)) {
425 struct sg_io_hdr __user *hp = buf;
426
427 return get_user(*pack_id, &hp->pack_id);
428 }
429 }
430
431 /* no valid header was passed, so ignore the pack_id */
432 *pack_id = -1;
433 return 0;
434}
435
436static ssize_t
437sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
438{
439 Sg_device *sdp;
440 Sg_fd *sfp;
441 Sg_request *srp;
442 int req_pack_id = -1;
443 bool busy;
444 sg_io_hdr_t *hp;
445 struct sg_header *old_hdr;
446 int retval;
447
448 /*
449 * This could cause a response to be stranded. Close the associated
450 * file descriptor to free up any resources being held.
451 */
452 retval = sg_check_file_access(filp, caller: __func__);
453 if (retval)
454 return retval;
455
456 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
457 return -ENXIO;
458 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
459 "sg_read: count=%d\n", (int) count));
460
461 if (sfp->force_packid)
462 retval = get_sg_io_pack_id(pack_id: &req_pack_id, buf, count);
463 if (retval)
464 return retval;
465
466 srp = sg_get_rq_mark(sfp, pack_id: req_pack_id, busy: &busy);
467 if (!srp) { /* now wait on packet to arrive */
468 if (filp->f_flags & O_NONBLOCK)
469 return -EAGAIN;
470 retval = wait_event_interruptible(sfp->read_wait,
471 ((srp = sg_get_rq_mark(sfp, req_pack_id, &busy)) ||
472 (!busy && atomic_read(&sdp->detaching))));
473 if (!srp)
474 /* signal or detaching */
475 return retval ? retval : -ENODEV;
476 }
477 if (srp->header.interface_id != '\0')
478 return sg_new_read(sfp, buf, count, srp);
479
480 hp = &srp->header;
481 old_hdr = kzalloc(SZ_SG_HEADER, GFP_KERNEL);
482 if (!old_hdr)
483 return -ENOMEM;
484
485 old_hdr->reply_len = (int) hp->timeout;
486 old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
487 old_hdr->pack_id = hp->pack_id;
488 old_hdr->twelve_byte =
489 ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
490 old_hdr->target_status = hp->masked_status;
491 old_hdr->host_status = hp->host_status;
492 old_hdr->driver_status = hp->driver_status;
493 if ((CHECK_CONDITION & hp->masked_status) ||
494 (srp->sense_b[0] & 0x70) == 0x70) {
495 old_hdr->driver_status = DRIVER_SENSE;
496 memcpy(to: old_hdr->sense_buffer, from: srp->sense_b,
497 len: sizeof (old_hdr->sense_buffer));
498 }
499 switch (hp->host_status) {
500 /* This setup of 'result' is for backward compatibility and is best
501 ignored by the user who should use target, host + driver status */
502 case DID_OK:
503 case DID_PASSTHROUGH:
504 case DID_SOFT_ERROR:
505 old_hdr->result = 0;
506 break;
507 case DID_NO_CONNECT:
508 case DID_BUS_BUSY:
509 case DID_TIME_OUT:
510 old_hdr->result = EBUSY;
511 break;
512 case DID_BAD_TARGET:
513 case DID_ABORT:
514 case DID_PARITY:
515 case DID_RESET:
516 case DID_BAD_INTR:
517 old_hdr->result = EIO;
518 break;
519 case DID_ERROR:
520 old_hdr->result = (srp->sense_b[0] == 0 &&
521 hp->masked_status == GOOD) ? 0 : EIO;
522 break;
523 default:
524 old_hdr->result = EIO;
525 break;
526 }
527
528 /* Now copy the result back to the user buffer. */
529 if (count >= SZ_SG_HEADER) {
530 if (copy_to_user(to: buf, from: old_hdr, SZ_SG_HEADER)) {
531 retval = -EFAULT;
532 goto free_old_hdr;
533 }
534 buf += SZ_SG_HEADER;
535 if (count > old_hdr->reply_len)
536 count = old_hdr->reply_len;
537 if (count > SZ_SG_HEADER) {
538 if (sg_read_oxfer(srp, outp: buf, num_read_xfer: count - SZ_SG_HEADER)) {
539 retval = -EFAULT;
540 goto free_old_hdr;
541 }
542 }
543 } else
544 count = (old_hdr->result == 0) ? 0 : -EIO;
545 sg_finish_rem_req(srp);
546 sg_remove_request(sfp, srp);
547 retval = count;
548free_old_hdr:
549 kfree(objp: old_hdr);
550 return retval;
551}
552
553static ssize_t
554sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
555{
556 sg_io_hdr_t *hp = &srp->header;
557 int err = 0, err2;
558 int len;
559
560 if (in_compat_syscall()) {
561 if (count < sizeof(struct compat_sg_io_hdr)) {
562 err = -EINVAL;
563 goto err_out;
564 }
565 } else if (count < SZ_SG_IO_HDR) {
566 err = -EINVAL;
567 goto err_out;
568 }
569 hp->sb_len_wr = 0;
570 if ((hp->mx_sb_len > 0) && hp->sbp) {
571 if ((CHECK_CONDITION & hp->masked_status) ||
572 (srp->sense_b[0] & 0x70) == 0x70) {
573 int sb_len = SCSI_SENSE_BUFFERSIZE;
574 sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
575 len = 8 + (int) srp->sense_b[7]; /* Additional sense length field */
576 len = (len > sb_len) ? sb_len : len;
577 if (copy_to_user(to: hp->sbp, from: srp->sense_b, n: len)) {
578 err = -EFAULT;
579 goto err_out;
580 }
581 hp->driver_status = DRIVER_SENSE;
582 hp->sb_len_wr = len;
583 }
584 }
585 if (hp->masked_status || hp->host_status || hp->driver_status)
586 hp->info |= SG_INFO_CHECK;
587 err = put_sg_io_hdr(hdr: hp, argp: buf);
588err_out:
589 err2 = sg_finish_rem_req(srp);
590 sg_remove_request(sfp, srp);
591 return err ? : err2 ? : count;
592}
593
594static ssize_t
595sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
596{
597 int mxsize, cmd_size, k;
598 int input_size, blocking;
599 unsigned char opcode;
600 Sg_device *sdp;
601 Sg_fd *sfp;
602 Sg_request *srp;
603 struct sg_header old_hdr;
604 sg_io_hdr_t *hp;
605 unsigned char cmnd[SG_MAX_CDB_SIZE];
606 int retval;
607
608 retval = sg_check_file_access(filp, caller: __func__);
609 if (retval)
610 return retval;
611
612 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
613 return -ENXIO;
614 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
615 "sg_write: count=%d\n", (int) count));
616 if (atomic_read(v: &sdp->detaching))
617 return -ENODEV;
618 if (!((filp->f_flags & O_NONBLOCK) ||
619 scsi_block_when_processing_errors(sdp->device)))
620 return -ENXIO;
621
622 if (count < SZ_SG_HEADER)
623 return -EIO;
624 if (copy_from_user(to: &old_hdr, from: buf, SZ_SG_HEADER))
625 return -EFAULT;
626 blocking = !(filp->f_flags & O_NONBLOCK);
627 if (old_hdr.reply_len < 0)
628 return sg_new_write(sfp, file: filp, buf, count,
629 blocking, read_only: 0, sg_io_owned: 0, NULL);
630 if (count < (SZ_SG_HEADER + 6))
631 return -EIO; /* The minimum scsi command length is 6 bytes. */
632
633 buf += SZ_SG_HEADER;
634 if (get_user(opcode, buf))
635 return -EFAULT;
636
637 if (!(srp = sg_add_request(sfp))) {
638 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
639 "sg_write: queue full\n"));
640 return -EDOM;
641 }
642 mutex_lock(lock: &sfp->f_mutex);
643 if (sfp->next_cmd_len > 0) {
644 cmd_size = sfp->next_cmd_len;
645 sfp->next_cmd_len = 0; /* reset so only this write() effected */
646 } else {
647 cmd_size = COMMAND_SIZE(opcode); /* based on SCSI command group */
648 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
649 cmd_size = 12;
650 }
651 mutex_unlock(lock: &sfp->f_mutex);
652 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
653 "sg_write: scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
654/* Determine buffer size. */
655 input_size = count - cmd_size;
656 mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
657 mxsize -= SZ_SG_HEADER;
658 input_size -= SZ_SG_HEADER;
659 if (input_size < 0) {
660 sg_remove_request(sfp, srp);
661 return -EIO; /* User did not pass enough bytes for this command. */
662 }
663 hp = &srp->header;
664 hp->interface_id = '\0'; /* indicator of old interface tunnelled */
665 hp->cmd_len = (unsigned char) cmd_size;
666 hp->iovec_count = 0;
667 hp->mx_sb_len = 0;
668 if (input_size > 0)
669 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
670 SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
671 else
672 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
673 hp->dxfer_len = mxsize;
674 if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
675 (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
676 hp->dxferp = (char __user *)buf + cmd_size;
677 else
678 hp->dxferp = NULL;
679 hp->sbp = NULL;
680 hp->timeout = old_hdr.reply_len; /* structure abuse ... */
681 hp->flags = input_size; /* structure abuse ... */
682 hp->pack_id = old_hdr.pack_id;
683 hp->usr_ptr = NULL;
684 if (copy_from_user(to: cmnd, from: buf, n: cmd_size)) {
685 sg_remove_request(sfp, srp);
686 return -EFAULT;
687 }
688 /*
689 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
690 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
691 * is a non-zero input_size, so emit a warning.
692 */
693 if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
694 printk_ratelimited(KERN_WARNING
695 "sg_write: data in/out %d/%d bytes "
696 "for SCSI command 0x%x-- guessing "
697 "data in;\n program %s not setting "
698 "count and/or reply_len properly\n",
699 old_hdr.reply_len - (int)SZ_SG_HEADER,
700 input_size, (unsigned int) cmnd[0],
701 current->comm);
702 }
703 k = sg_common_write(sfp, srp, cmnd, timeout: sfp->timeout, blocking);
704 return (k < 0) ? k : count;
705}
706
707static ssize_t
708sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
709 size_t count, int blocking, int read_only, int sg_io_owned,
710 Sg_request **o_srp)
711{
712 int k;
713 Sg_request *srp;
714 sg_io_hdr_t *hp;
715 unsigned char cmnd[SG_MAX_CDB_SIZE];
716 int timeout;
717 unsigned long ul_timeout;
718
719 if (count < SZ_SG_IO_HDR)
720 return -EINVAL;
721
722 sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
723 if (!(srp = sg_add_request(sfp))) {
724 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
725 "sg_new_write: queue full\n"));
726 return -EDOM;
727 }
728 srp->sg_io_owned = sg_io_owned;
729 hp = &srp->header;
730 if (get_sg_io_hdr(hdr: hp, argp: buf)) {
731 sg_remove_request(sfp, srp);
732 return -EFAULT;
733 }
734 if (hp->interface_id != 'S') {
735 sg_remove_request(sfp, srp);
736 return -ENOSYS;
737 }
738 if (hp->flags & SG_FLAG_MMAP_IO) {
739 if (hp->dxfer_len > sfp->reserve.bufflen) {
740 sg_remove_request(sfp, srp);
741 return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
742 }
743 if (hp->flags & SG_FLAG_DIRECT_IO) {
744 sg_remove_request(sfp, srp);
745 return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
746 }
747 if (sfp->res_in_use) {
748 sg_remove_request(sfp, srp);
749 return -EBUSY; /* reserve buffer already being used */
750 }
751 }
752 ul_timeout = msecs_to_jiffies(m: srp->header.timeout);
753 timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
754 if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
755 sg_remove_request(sfp, srp);
756 return -EMSGSIZE;
757 }
758 if (copy_from_user(to: cmnd, from: hp->cmdp, n: hp->cmd_len)) {
759 sg_remove_request(sfp, srp);
760 return -EFAULT;
761 }
762 if (read_only && sg_allow_access(filp: file, cmd: cmnd)) {
763 sg_remove_request(sfp, srp);
764 return -EPERM;
765 }
766 k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
767 if (k < 0)
768 return k;
769 if (o_srp)
770 *o_srp = srp;
771 return count;
772}
773
774static int
775sg_common_write(Sg_fd * sfp, Sg_request * srp,
776 unsigned char *cmnd, int timeout, int blocking)
777{
778 int k, at_head;
779 Sg_device *sdp = sfp->parentdp;
780 sg_io_hdr_t *hp = &srp->header;
781
782 srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
783 hp->status = 0;
784 hp->masked_status = 0;
785 hp->msg_status = 0;
786 hp->info = 0;
787 hp->host_status = 0;
788 hp->driver_status = 0;
789 hp->resid = 0;
790 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
791 "sg_common_write: scsi opcode=0x%02x, cmd_size=%d\n",
792 (int) cmnd[0], (int) hp->cmd_len));
793
794 if (hp->dxfer_len >= SZ_256M) {
795 sg_remove_request(sfp, srp);
796 return -EINVAL;
797 }
798
799 k = sg_start_req(srp, cmd: cmnd);
800 if (k) {
801 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
802 "sg_common_write: start_req err=%d\n", k));
803 sg_finish_rem_req(srp);
804 sg_remove_request(sfp, srp);
805 return k; /* probably out of space --> ENOMEM */
806 }
807 if (atomic_read(v: &sdp->detaching)) {
808 if (srp->bio) {
809 blk_mq_free_request(rq: srp->rq);
810 srp->rq = NULL;
811 }
812
813 sg_finish_rem_req(srp);
814 sg_remove_request(sfp, srp);
815 return -ENODEV;
816 }
817
818 hp->duration = jiffies_to_msecs(j: jiffies);
819 if (hp->interface_id != '\0' && /* v3 (or later) interface */
820 (SG_FLAG_Q_AT_TAIL & hp->flags))
821 at_head = 0;
822 else
823 at_head = 1;
824
825 srp->rq->timeout = timeout;
826 kref_get(kref: &sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
827 srp->rq->end_io = sg_rq_end_io;
828 blk_execute_rq_nowait(rq: srp->rq, at_head);
829 return 0;
830}
831
832static int srp_done(Sg_fd *sfp, Sg_request *srp)
833{
834 unsigned long flags;
835 int ret;
836
837 read_lock_irqsave(&sfp->rq_list_lock, flags);
838 ret = srp->done;
839 read_unlock_irqrestore(&sfp->rq_list_lock, flags);
840 return ret;
841}
842
843static int max_sectors_bytes(struct request_queue *q)
844{
845 unsigned int max_sectors = queue_max_sectors(q);
846
847 max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
848
849 return max_sectors << 9;
850}
851
852static void
853sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
854{
855 Sg_request *srp;
856 int val;
857 unsigned int ms;
858
859 val = 0;
860 list_for_each_entry(srp, &sfp->rq_list, entry) {
861 if (val >= SG_MAX_QUEUE)
862 break;
863 rinfo[val].req_state = srp->done + 1;
864 rinfo[val].problem =
865 srp->header.masked_status &
866 srp->header.host_status &
867 srp->header.driver_status;
868 if (srp->done)
869 rinfo[val].duration =
870 srp->header.duration;
871 else {
872 ms = jiffies_to_msecs(j: jiffies);
873 rinfo[val].duration =
874 (ms > srp->header.duration) ?
875 (ms - srp->header.duration) : 0;
876 }
877 rinfo[val].orphan = srp->orphan;
878 rinfo[val].sg_io_owned = srp->sg_io_owned;
879 rinfo[val].pack_id = srp->header.pack_id;
880 rinfo[val].usr_ptr = srp->header.usr_ptr;
881 val++;
882 }
883}
884
885#ifdef CONFIG_COMPAT
886struct compat_sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
887 char req_state;
888 char orphan;
889 char sg_io_owned;
890 char problem;
891 int pack_id;
892 compat_uptr_t usr_ptr;
893 unsigned int duration;
894 int unused;
895};
896
897static int put_compat_request_table(struct compat_sg_req_info __user *o,
898 struct sg_req_info *rinfo)
899{
900 int i;
901 for (i = 0; i < SG_MAX_QUEUE; i++) {
902 if (copy_to_user(to: o + i, from: rinfo + i, offsetof(sg_req_info_t, usr_ptr)) ||
903 put_user((uintptr_t)rinfo[i].usr_ptr, &o[i].usr_ptr) ||
904 put_user(rinfo[i].duration, &o[i].duration) ||
905 put_user(rinfo[i].unused, &o[i].unused))
906 return -EFAULT;
907 }
908 return 0;
909}
910#endif
911
912static long
913sg_ioctl_common(struct file *filp, Sg_device *sdp, Sg_fd *sfp,
914 unsigned int cmd_in, void __user *p)
915{
916 int __user *ip = p;
917 int result, val, read_only;
918 Sg_request *srp;
919 unsigned long iflags;
920
921 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
922 "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
923 read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
924
925 switch (cmd_in) {
926 case SG_IO:
927 if (atomic_read(v: &sdp->detaching))
928 return -ENODEV;
929 if (!scsi_block_when_processing_errors(sdp->device))
930 return -ENXIO;
931 result = sg_new_write(sfp, file: filp, buf: p, SZ_SG_IO_HDR,
932 blocking: 1, read_only, sg_io_owned: 1, o_srp: &srp);
933 if (result < 0)
934 return result;
935 result = wait_event_interruptible(sfp->read_wait,
936 srp_done(sfp, srp));
937 write_lock_irq(&sfp->rq_list_lock);
938 if (srp->done) {
939 srp->done = 2;
940 write_unlock_irq(&sfp->rq_list_lock);
941 result = sg_new_read(sfp, buf: p, SZ_SG_IO_HDR, srp);
942 return (result < 0) ? result : 0;
943 }
944 srp->orphan = 1;
945 write_unlock_irq(&sfp->rq_list_lock);
946 return result; /* -ERESTARTSYS because signal hit process */
947 case SG_SET_TIMEOUT:
948 result = get_user(val, ip);
949 if (result)
950 return result;
951 if (val < 0)
952 return -EIO;
953 if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
954 val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
955 INT_MAX);
956 sfp->timeout_user = val;
957 sfp->timeout = mult_frac(val, HZ, USER_HZ);
958
959 return 0;
960 case SG_GET_TIMEOUT: /* N.B. User receives timeout as return value */
961 /* strange ..., for backward compatibility */
962 return sfp->timeout_user;
963 case SG_SET_FORCE_LOW_DMA:
964 /*
965 * N.B. This ioctl never worked properly, but failed to
966 * return an error value. So returning '0' to keep compability
967 * with legacy applications.
968 */
969 return 0;
970 case SG_GET_LOW_DMA:
971 return put_user(0, ip);
972 case SG_GET_SCSI_ID:
973 {
974 sg_scsi_id_t v;
975
976 if (atomic_read(v: &sdp->detaching))
977 return -ENODEV;
978 memset(s: &v, c: 0, n: sizeof(v));
979 v.host_no = sdp->device->host->host_no;
980 v.channel = sdp->device->channel;
981 v.scsi_id = sdp->device->id;
982 v.lun = sdp->device->lun;
983 v.scsi_type = sdp->device->type;
984 v.h_cmd_per_lun = sdp->device->host->cmd_per_lun;
985 v.d_queue_depth = sdp->device->queue_depth;
986 if (copy_to_user(to: p, from: &v, n: sizeof(sg_scsi_id_t)))
987 return -EFAULT;
988 return 0;
989 }
990 case SG_SET_FORCE_PACK_ID:
991 result = get_user(val, ip);
992 if (result)
993 return result;
994 sfp->force_packid = val ? 1 : 0;
995 return 0;
996 case SG_GET_PACK_ID:
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 return put_user(srp->header.pack_id, ip);
1003 }
1004 }
1005 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1006 return put_user(-1, ip);
1007 case SG_GET_NUM_WAITING:
1008 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1009 val = 0;
1010 list_for_each_entry(srp, &sfp->rq_list, entry) {
1011 if ((1 == srp->done) && (!srp->sg_io_owned))
1012 ++val;
1013 }
1014 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1015 return put_user(val, ip);
1016 case SG_GET_SG_TABLESIZE:
1017 return put_user(sdp->sg_tablesize, ip);
1018 case SG_SET_RESERVED_SIZE:
1019 result = get_user(val, ip);
1020 if (result)
1021 return result;
1022 if (val < 0)
1023 return -EINVAL;
1024 val = min_t(int, val,
1025 max_sectors_bytes(sdp->device->request_queue));
1026 mutex_lock(lock: &sfp->f_mutex);
1027 if (val != sfp->reserve.bufflen) {
1028 if (sfp->mmap_called ||
1029 sfp->res_in_use) {
1030 mutex_unlock(lock: &sfp->f_mutex);
1031 return -EBUSY;
1032 }
1033
1034 sg_remove_scat(sfp, schp: &sfp->reserve);
1035 sg_build_reserve(sfp, req_size: val);
1036 }
1037 mutex_unlock(lock: &sfp->f_mutex);
1038 return 0;
1039 case SG_GET_RESERVED_SIZE:
1040 val = min_t(int, sfp->reserve.bufflen,
1041 max_sectors_bytes(sdp->device->request_queue));
1042 return put_user(val, ip);
1043 case SG_SET_COMMAND_Q:
1044 result = get_user(val, ip);
1045 if (result)
1046 return result;
1047 sfp->cmd_q = val ? 1 : 0;
1048 return 0;
1049 case SG_GET_COMMAND_Q:
1050 return put_user((int) sfp->cmd_q, ip);
1051 case SG_SET_KEEP_ORPHAN:
1052 result = get_user(val, ip);
1053 if (result)
1054 return result;
1055 sfp->keep_orphan = val;
1056 return 0;
1057 case SG_GET_KEEP_ORPHAN:
1058 return put_user((int) sfp->keep_orphan, ip);
1059 case SG_NEXT_CMD_LEN:
1060 result = get_user(val, ip);
1061 if (result)
1062 return result;
1063 if (val > SG_MAX_CDB_SIZE)
1064 return -ENOMEM;
1065 sfp->next_cmd_len = (val > 0) ? val : 0;
1066 return 0;
1067 case SG_GET_VERSION_NUM:
1068 return put_user(sg_version_num, ip);
1069 case SG_GET_ACCESS_COUNT:
1070 /* faked - we don't have a real access count anymore */
1071 val = (sdp->device ? 1 : 0);
1072 return put_user(val, ip);
1073 case SG_GET_REQUEST_TABLE:
1074 {
1075 sg_req_info_t *rinfo;
1076
1077 rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
1078 GFP_KERNEL);
1079 if (!rinfo)
1080 return -ENOMEM;
1081 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1082 sg_fill_request_table(sfp, rinfo);
1083 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1084 #ifdef CONFIG_COMPAT
1085 if (in_compat_syscall())
1086 result = put_compat_request_table(o: p, rinfo);
1087 else
1088 #endif
1089 result = copy_to_user(to: p, from: rinfo,
1090 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1091 result = result ? -EFAULT : 0;
1092 kfree(objp: rinfo);
1093 return result;
1094 }
1095 case SG_EMULATED_HOST:
1096 if (atomic_read(v: &sdp->detaching))
1097 return -ENODEV;
1098 return put_user(sdp->device->host->hostt->emulated, ip);
1099 case SCSI_IOCTL_SEND_COMMAND:
1100 if (atomic_read(v: &sdp->detaching))
1101 return -ENODEV;
1102 return scsi_ioctl(sdev: sdp->device, open_for_write: filp->f_mode & FMODE_WRITE,
1103 cmd: cmd_in, arg: p);
1104 case SG_SET_DEBUG:
1105 result = get_user(val, ip);
1106 if (result)
1107 return result;
1108 sdp->sgdebug = (char) val;
1109 return 0;
1110 case BLKSECTGET:
1111 return put_user(max_sectors_bytes(sdp->device->request_queue),
1112 ip);
1113 case BLKTRACESETUP:
1114 return blk_trace_setup(q: sdp->device->request_queue, name: sdp->name,
1115 MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1116 NULL, arg: p);
1117 case BLKTRACESTART:
1118 return blk_trace_startstop(q: sdp->device->request_queue, start: 1);
1119 case BLKTRACESTOP:
1120 return blk_trace_startstop(q: sdp->device->request_queue, start: 0);
1121 case BLKTRACETEARDOWN:
1122 return blk_trace_remove(q: sdp->device->request_queue);
1123 case SCSI_IOCTL_GET_IDLUN:
1124 case SCSI_IOCTL_GET_BUS_NUMBER:
1125 case SCSI_IOCTL_PROBE_HOST:
1126 case SG_GET_TRANSFORM:
1127 case SG_SCSI_RESET:
1128 if (atomic_read(v: &sdp->detaching))
1129 return -ENODEV;
1130 break;
1131 default:
1132 if (read_only)
1133 return -EPERM; /* don't know so take safe approach */
1134 break;
1135 }
1136
1137 result = scsi_ioctl_block_when_processing_errors(sdev: sdp->device,
1138 cmd: cmd_in, ndelay: filp->f_flags & O_NDELAY);
1139 if (result)
1140 return result;
1141
1142 return -ENOIOCTLCMD;
1143}
1144
1145static long
1146sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1147{
1148 void __user *p = (void __user *)arg;
1149 Sg_device *sdp;
1150 Sg_fd *sfp;
1151 int ret;
1152
1153 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1154 return -ENXIO;
1155
1156 ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
1157 if (ret != -ENOIOCTLCMD)
1158 return ret;
1159 return scsi_ioctl(sdev: sdp->device, open_for_write: filp->f_mode & FMODE_WRITE, cmd: cmd_in, arg: p);
1160}
1161
1162static __poll_t
1163sg_poll(struct file *filp, poll_table * wait)
1164{
1165 __poll_t res = 0;
1166 Sg_device *sdp;
1167 Sg_fd *sfp;
1168 Sg_request *srp;
1169 int count = 0;
1170 unsigned long iflags;
1171
1172 sfp = filp->private_data;
1173 if (!sfp)
1174 return EPOLLERR;
1175 sdp = sfp->parentdp;
1176 if (!sdp)
1177 return EPOLLERR;
1178 poll_wait(filp, wait_address: &sfp->read_wait, p: wait);
1179 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1180 list_for_each_entry(srp, &sfp->rq_list, entry) {
1181 /* if any read waiting, flag it */
1182 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1183 res = EPOLLIN | EPOLLRDNORM;
1184 ++count;
1185 }
1186 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1187
1188 if (atomic_read(v: &sdp->detaching))
1189 res |= EPOLLHUP;
1190 else if (!sfp->cmd_q) {
1191 if (0 == count)
1192 res |= EPOLLOUT | EPOLLWRNORM;
1193 } else if (count < SG_MAX_QUEUE)
1194 res |= EPOLLOUT | EPOLLWRNORM;
1195 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1196 "sg_poll: res=0x%x\n", (__force u32) res));
1197 return res;
1198}
1199
1200static int
1201sg_fasync(int fd, struct file *filp, int mode)
1202{
1203 Sg_device *sdp;
1204 Sg_fd *sfp;
1205
1206 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1207 return -ENXIO;
1208 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1209 "sg_fasync: mode=%d\n", mode));
1210
1211 return fasync_helper(fd, filp, mode, &sfp->async_qp);
1212}
1213
1214static vm_fault_t
1215sg_vma_fault(struct vm_fault *vmf)
1216{
1217 struct vm_area_struct *vma = vmf->vma;
1218 Sg_fd *sfp;
1219 unsigned long offset, len, sa;
1220 Sg_scatter_hold *rsv_schp;
1221 int k, length;
1222
1223 if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1224 return VM_FAULT_SIGBUS;
1225 rsv_schp = &sfp->reserve;
1226 offset = vmf->pgoff << PAGE_SHIFT;
1227 if (offset >= rsv_schp->bufflen)
1228 return VM_FAULT_SIGBUS;
1229 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1230 "sg_vma_fault: offset=%lu, scatg=%d\n",
1231 offset, rsv_schp->k_use_sg));
1232 sa = vma->vm_start;
1233 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1234 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1235 len = vma->vm_end - sa;
1236 len = (len < length) ? len : length;
1237 if (offset < len) {
1238 struct page *page = rsv_schp->pages[k] + (offset >> PAGE_SHIFT);
1239 get_page(page); /* increment page count */
1240 vmf->page = page;
1241 return 0; /* success */
1242 }
1243 sa += len;
1244 offset -= len;
1245 }
1246
1247 return VM_FAULT_SIGBUS;
1248}
1249
1250static const struct vm_operations_struct sg_mmap_vm_ops = {
1251 .fault = sg_vma_fault,
1252};
1253
1254static int
1255sg_mmap(struct file *filp, struct vm_area_struct *vma)
1256{
1257 Sg_fd *sfp;
1258 unsigned long req_sz, len, sa;
1259 Sg_scatter_hold *rsv_schp;
1260 int k, length;
1261 int ret = 0;
1262
1263 if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1264 return -ENXIO;
1265 req_sz = vma->vm_end - vma->vm_start;
1266 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1267 "sg_mmap starting, vm_start=%p, len=%d\n",
1268 (void *) vma->vm_start, (int) req_sz));
1269 if (vma->vm_pgoff)
1270 return -EINVAL; /* want no offset */
1271 rsv_schp = &sfp->reserve;
1272 mutex_lock(lock: &sfp->f_mutex);
1273 if (req_sz > rsv_schp->bufflen) {
1274 ret = -ENOMEM; /* cannot map more than reserved buffer */
1275 goto out;
1276 }
1277
1278 sa = vma->vm_start;
1279 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1280 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1281 len = vma->vm_end - sa;
1282 len = (len < length) ? len : length;
1283 sa += len;
1284 }
1285
1286 sfp->mmap_called = 1;
1287 vm_flags_set(vma, VM_IO | VM_DONTEXPAND | VM_DONTDUMP);
1288 vma->vm_private_data = sfp;
1289 vma->vm_ops = &sg_mmap_vm_ops;
1290out:
1291 mutex_unlock(lock: &sfp->f_mutex);
1292 return ret;
1293}
1294
1295static void
1296sg_rq_end_io_usercontext(struct work_struct *work)
1297{
1298 struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1299 struct sg_fd *sfp = srp->parentfp;
1300
1301 sg_finish_rem_req(srp);
1302 sg_remove_request(sfp, srp);
1303 kref_put(kref: &sfp->f_ref, release: sg_remove_sfp);
1304}
1305
1306/*
1307 * This function is a "bottom half" handler that is called by the mid
1308 * level when a command is completed (or has failed).
1309 */
1310static enum rq_end_io_ret
1311sg_rq_end_io(struct request *rq, blk_status_t status)
1312{
1313 struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
1314 struct sg_request *srp = rq->end_io_data;
1315 Sg_device *sdp;
1316 Sg_fd *sfp;
1317 unsigned long iflags;
1318 unsigned int ms;
1319 char *sense;
1320 int result, resid, done = 1;
1321
1322 if (WARN_ON(srp->done != 0))
1323 return RQ_END_IO_NONE;
1324
1325 sfp = srp->parentfp;
1326 if (WARN_ON(sfp == NULL))
1327 return RQ_END_IO_NONE;
1328
1329 sdp = sfp->parentdp;
1330 if (unlikely(atomic_read(&sdp->detaching)))
1331 pr_info("%s: device detaching\n", __func__);
1332
1333 sense = scmd->sense_buffer;
1334 result = scmd->result;
1335 resid = scmd->resid_len;
1336
1337 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1338 "sg_cmd_done: pack_id=%d, res=0x%x\n",
1339 srp->header.pack_id, result));
1340 srp->header.resid = resid;
1341 ms = jiffies_to_msecs(j: jiffies);
1342 srp->header.duration = (ms > srp->header.duration) ?
1343 (ms - srp->header.duration) : 0;
1344 if (0 != result) {
1345 struct scsi_sense_hdr sshdr;
1346
1347 srp->header.status = 0xff & result;
1348 srp->header.masked_status = sg_status_byte(result);
1349 srp->header.msg_status = COMMAND_COMPLETE;
1350 srp->header.host_status = host_byte(result);
1351 srp->header.driver_status = driver_byte(result);
1352 if ((sdp->sgdebug > 0) &&
1353 ((CHECK_CONDITION == srp->header.masked_status) ||
1354 (COMMAND_TERMINATED == srp->header.masked_status)))
1355 __scsi_print_sense(sdp->device, name: __func__, sense_buffer: sense,
1356 SCSI_SENSE_BUFFERSIZE);
1357
1358 /* Following if statement is a patch supplied by Eric Youngdale */
1359 if (driver_byte(result) != 0
1360 && scsi_normalize_sense(sense_buffer: sense, SCSI_SENSE_BUFFERSIZE, sshdr: &sshdr)
1361 && !scsi_sense_is_deferred(sshdr: &sshdr)
1362 && sshdr.sense_key == UNIT_ATTENTION
1363 && sdp->device->removable) {
1364 /* Detected possible disc change. Set the bit - this */
1365 /* may be used if there are filesystems using this device */
1366 sdp->device->changed = 1;
1367 }
1368 }
1369
1370 if (scmd->sense_len)
1371 memcpy(to: srp->sense_b, from: scmd->sense_buffer, SCSI_SENSE_BUFFERSIZE);
1372
1373 /* Rely on write phase to clean out srp status values, so no "else" */
1374
1375 /*
1376 * Free the request as soon as it is complete so that its resources
1377 * can be reused without waiting for userspace to read() the
1378 * result. But keep the associated bio (if any) around until
1379 * blk_rq_unmap_user() can be called from user context.
1380 */
1381 srp->rq = NULL;
1382 blk_mq_free_request(rq);
1383
1384 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1385 if (unlikely(srp->orphan)) {
1386 if (sfp->keep_orphan)
1387 srp->sg_io_owned = 0;
1388 else
1389 done = 0;
1390 }
1391 srp->done = done;
1392 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1393
1394 if (likely(done)) {
1395 /* Now wake up any sg_read() that is waiting for this
1396 * packet.
1397 */
1398 wake_up_interruptible(&sfp->read_wait);
1399 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1400 kref_put(kref: &sfp->f_ref, release: sg_remove_sfp);
1401 } else {
1402 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1403 schedule_work(work: &srp->ew.work);
1404 }
1405 return RQ_END_IO_NONE;
1406}
1407
1408static const struct file_operations sg_fops = {
1409 .owner = THIS_MODULE,
1410 .read = sg_read,
1411 .write = sg_write,
1412 .poll = sg_poll,
1413 .unlocked_ioctl = sg_ioctl,
1414 .compat_ioctl = compat_ptr_ioctl,
1415 .open = sg_open,
1416 .mmap = sg_mmap,
1417 .release = sg_release,
1418 .fasync = sg_fasync,
1419};
1420
1421static const struct class sg_sysfs_class = {
1422 .name = "scsi_generic"
1423};
1424
1425static int sg_sysfs_valid = 0;
1426
1427static Sg_device *
1428sg_alloc(struct scsi_device *scsidp)
1429{
1430 struct request_queue *q = scsidp->request_queue;
1431 Sg_device *sdp;
1432 unsigned long iflags;
1433 int error;
1434 u32 k;
1435
1436 sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1437 if (!sdp) {
1438 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1439 "failure\n", __func__);
1440 return ERR_PTR(error: -ENOMEM);
1441 }
1442
1443 idr_preload(GFP_KERNEL);
1444 write_lock_irqsave(&sg_index_lock, iflags);
1445
1446 error = idr_alloc(&sg_index_idr, ptr: sdp, start: 0, SG_MAX_DEVS, GFP_NOWAIT);
1447 if (error < 0) {
1448 if (error == -ENOSPC) {
1449 sdev_printk(KERN_WARNING, scsidp,
1450 "Unable to attach sg device type=%d, minor number exceeds %d\n",
1451 scsidp->type, SG_MAX_DEVS - 1);
1452 error = -ENODEV;
1453 } else {
1454 sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1455 "allocation Sg_device failure: %d\n",
1456 __func__, error);
1457 }
1458 goto out_unlock;
1459 }
1460 k = error;
1461
1462 SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1463 "sg_alloc: dev=%d \n", k));
1464 sprintf(buf: sdp->name, fmt: "sg%d", k);
1465 sdp->device = scsidp;
1466 mutex_init(&sdp->open_rel_lock);
1467 INIT_LIST_HEAD(list: &sdp->sfds);
1468 init_waitqueue_head(&sdp->open_wait);
1469 atomic_set(v: &sdp->detaching, i: 0);
1470 rwlock_init(&sdp->sfd_lock);
1471 sdp->sg_tablesize = queue_max_segments(q);
1472 sdp->index = k;
1473 kref_init(kref: &sdp->d_ref);
1474 error = 0;
1475
1476out_unlock:
1477 write_unlock_irqrestore(&sg_index_lock, iflags);
1478 idr_preload_end();
1479
1480 if (error) {
1481 kfree(objp: sdp);
1482 return ERR_PTR(error);
1483 }
1484 return sdp;
1485}
1486
1487static int
1488sg_add_device(struct device *cl_dev)
1489{
1490 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1491 Sg_device *sdp = NULL;
1492 struct cdev * cdev = NULL;
1493 int error;
1494 unsigned long iflags;
1495
1496 if (!blk_get_queue(scsidp->request_queue)) {
1497 pr_warn("%s: get scsi_device queue failed\n", __func__);
1498 return -ENODEV;
1499 }
1500
1501 error = -ENOMEM;
1502 cdev = cdev_alloc();
1503 if (!cdev) {
1504 pr_warn("%s: cdev_alloc failed\n", __func__);
1505 goto out;
1506 }
1507 cdev->owner = THIS_MODULE;
1508 cdev->ops = &sg_fops;
1509
1510 sdp = sg_alloc(scsidp);
1511 if (IS_ERR(ptr: sdp)) {
1512 pr_warn("%s: sg_alloc failed\n", __func__);
1513 error = PTR_ERR(ptr: sdp);
1514 goto out;
1515 }
1516
1517 error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1518 if (error)
1519 goto cdev_add_err;
1520
1521 sdp->cdev = cdev;
1522 if (sg_sysfs_valid) {
1523 struct device *sg_class_member;
1524
1525 sg_class_member = device_create(cls: &sg_sysfs_class, parent: cl_dev->parent,
1526 MKDEV(SCSI_GENERIC_MAJOR,
1527 sdp->index),
1528 drvdata: sdp, fmt: "%s", sdp->name);
1529 if (IS_ERR(ptr: sg_class_member)) {
1530 pr_err("%s: device_create failed\n", __func__);
1531 error = PTR_ERR(ptr: sg_class_member);
1532 goto cdev_add_err;
1533 }
1534 error = sysfs_create_link(kobj: &scsidp->sdev_gendev.kobj,
1535 target: &sg_class_member->kobj, name: "generic");
1536 if (error)
1537 pr_err("%s: unable to make symlink 'generic' back "
1538 "to sg%d\n", __func__, sdp->index);
1539 } else
1540 pr_warn("%s: sg_sys Invalid\n", __func__);
1541
1542 sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1543 "type %d\n", sdp->index, scsidp->type);
1544
1545 dev_set_drvdata(dev: cl_dev, data: sdp);
1546
1547 return 0;
1548
1549cdev_add_err:
1550 write_lock_irqsave(&sg_index_lock, iflags);
1551 idr_remove(&sg_index_idr, id: sdp->index);
1552 write_unlock_irqrestore(&sg_index_lock, iflags);
1553 kfree(objp: sdp);
1554
1555out:
1556 if (cdev)
1557 cdev_del(cdev);
1558 blk_put_queue(scsidp->request_queue);
1559 return error;
1560}
1561
1562static void
1563sg_device_destroy(struct kref *kref)
1564{
1565 struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1566 struct request_queue *q = sdp->device->request_queue;
1567 unsigned long flags;
1568
1569 /* CAUTION! Note that the device can still be found via idr_find()
1570 * even though the refcount is 0. Therefore, do idr_remove() BEFORE
1571 * any other cleanup.
1572 */
1573
1574 blk_trace_remove(q);
1575 blk_put_queue(q);
1576
1577 write_lock_irqsave(&sg_index_lock, flags);
1578 idr_remove(&sg_index_idr, id: sdp->index);
1579 write_unlock_irqrestore(&sg_index_lock, flags);
1580
1581 SCSI_LOG_TIMEOUT(3,
1582 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1583
1584 kfree(objp: sdp);
1585}
1586
1587static void
1588sg_remove_device(struct device *cl_dev)
1589{
1590 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1591 Sg_device *sdp = dev_get_drvdata(dev: cl_dev);
1592 unsigned long iflags;
1593 Sg_fd *sfp;
1594 int val;
1595
1596 if (!sdp)
1597 return;
1598 /* want sdp->detaching non-zero as soon as possible */
1599 val = atomic_inc_return(v: &sdp->detaching);
1600 if (val > 1)
1601 return; /* only want to do following once per device */
1602
1603 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1604 "%s\n", __func__));
1605
1606 read_lock_irqsave(&sdp->sfd_lock, iflags);
1607 list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1608 wake_up_interruptible_all(&sfp->read_wait);
1609 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1610 }
1611 wake_up_interruptible_all(&sdp->open_wait);
1612 read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1613
1614 sysfs_remove_link(kobj: &scsidp->sdev_gendev.kobj, name: "generic");
1615 device_destroy(cls: &sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1616 cdev_del(sdp->cdev);
1617 sdp->cdev = NULL;
1618
1619 kref_put(kref: &sdp->d_ref, release: sg_device_destroy);
1620}
1621
1622module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1623module_param_named(def_reserved_size, def_reserved_size, int,
1624 S_IRUGO | S_IWUSR);
1625module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1626
1627MODULE_AUTHOR("Douglas Gilbert");
1628MODULE_DESCRIPTION("SCSI generic (sg) driver");
1629MODULE_LICENSE("GPL");
1630MODULE_VERSION(SG_VERSION_STR);
1631MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1632
1633MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1634 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1635MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1636MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1637
1638#ifdef CONFIG_SYSCTL
1639#include <linux/sysctl.h>
1640
1641static const struct ctl_table sg_sysctls[] = {
1642 {
1643 .procname = "sg-big-buff",
1644 .data = &sg_big_buff,
1645 .maxlen = sizeof(int),
1646 .mode = 0444,
1647 .proc_handler = proc_dointvec,
1648 },
1649};
1650
1651static struct ctl_table_header *hdr;
1652static void register_sg_sysctls(void)
1653{
1654 if (!hdr)
1655 hdr = register_sysctl("kernel", sg_sysctls);
1656}
1657
1658static void unregister_sg_sysctls(void)
1659{
1660 unregister_sysctl_table(table: hdr);
1661}
1662#else
1663#define register_sg_sysctls() do { } while (0)
1664#define unregister_sg_sysctls() do { } while (0)
1665#endif /* CONFIG_SYSCTL */
1666
1667static int __init
1668init_sg(void)
1669{
1670 int rc;
1671
1672 if (scatter_elem_sz < PAGE_SIZE) {
1673 scatter_elem_sz = PAGE_SIZE;
1674 scatter_elem_sz_prev = scatter_elem_sz;
1675 }
1676 if (def_reserved_size >= 0)
1677 sg_big_buff = def_reserved_size;
1678 else
1679 def_reserved_size = sg_big_buff;
1680
1681 rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1682 SG_MAX_DEVS, "sg");
1683 if (rc)
1684 return rc;
1685 rc = class_register(class: &sg_sysfs_class);
1686 if (rc)
1687 goto err_out;
1688 sg_sysfs_valid = 1;
1689 rc = scsi_register_interface(&sg_interface);
1690 if (0 == rc) {
1691#ifdef CONFIG_SCSI_PROC_FS
1692 sg_proc_init();
1693#endif /* CONFIG_SCSI_PROC_FS */
1694 return 0;
1695 }
1696 class_unregister(class: &sg_sysfs_class);
1697 register_sg_sysctls();
1698err_out:
1699 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1700 return rc;
1701}
1702
1703static void __exit
1704exit_sg(void)
1705{
1706 unregister_sg_sysctls();
1707#ifdef CONFIG_SCSI_PROC_FS
1708 remove_proc_subtree("scsi/sg", NULL);
1709#endif /* CONFIG_SCSI_PROC_FS */
1710 scsi_unregister_interface(&sg_interface);
1711 class_unregister(class: &sg_sysfs_class);
1712 sg_sysfs_valid = 0;
1713 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1714 SG_MAX_DEVS);
1715 idr_destroy(&sg_index_idr);
1716}
1717
1718static int
1719sg_start_req(Sg_request *srp, unsigned char *cmd)
1720{
1721 int res;
1722 struct request *rq;
1723 Sg_fd *sfp = srp->parentfp;
1724 sg_io_hdr_t *hp = &srp->header;
1725 int dxfer_len = (int) hp->dxfer_len;
1726 int dxfer_dir = hp->dxfer_direction;
1727 unsigned int iov_count = hp->iovec_count;
1728 Sg_scatter_hold *req_schp = &srp->data;
1729 Sg_scatter_hold *rsv_schp = &sfp->reserve;
1730 struct request_queue *q = sfp->parentdp->device->request_queue;
1731 struct rq_map_data *md, map_data;
1732 int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? ITER_SOURCE : ITER_DEST;
1733 struct scsi_cmnd *scmd;
1734
1735 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1736 "sg_start_req: dxfer_len=%d\n",
1737 dxfer_len));
1738
1739 /*
1740 * NOTE
1741 *
1742 * With scsi-mq enabled, there are a fixed number of preallocated
1743 * requests equal in number to shost->can_queue. If all of the
1744 * preallocated requests are already in use, then scsi_alloc_request()
1745 * will sleep until an active command completes, freeing up a request.
1746 * Although waiting in an asynchronous interface is less than ideal, we
1747 * do not want to use BLK_MQ_REQ_NOWAIT here because userspace might
1748 * not expect an EWOULDBLOCK from this condition.
1749 */
1750 rq = scsi_alloc_request(q, opf: hp->dxfer_direction == SG_DXFER_TO_DEV ?
1751 REQ_OP_DRV_OUT : REQ_OP_DRV_IN, flags: 0);
1752 if (IS_ERR(ptr: rq))
1753 return PTR_ERR(ptr: rq);
1754 scmd = blk_mq_rq_to_pdu(rq);
1755
1756 if (hp->cmd_len > sizeof(scmd->cmnd)) {
1757 blk_mq_free_request(rq);
1758 return -EINVAL;
1759 }
1760
1761 memcpy(to: scmd->cmnd, from: cmd, len: hp->cmd_len);
1762 scmd->cmd_len = hp->cmd_len;
1763
1764 srp->rq = rq;
1765 rq->end_io_data = srp;
1766 scmd->allowed = SG_DEFAULT_RETRIES;
1767
1768 if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1769 return 0;
1770
1771 if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1772 dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1773 blk_rq_aligned(q, addr: (unsigned long)hp->dxferp, len: dxfer_len))
1774 md = NULL;
1775 else
1776 md = &map_data;
1777
1778 if (md) {
1779 mutex_lock(lock: &sfp->f_mutex);
1780 if (dxfer_len <= rsv_schp->bufflen &&
1781 !sfp->res_in_use) {
1782 sfp->res_in_use = 1;
1783 sg_link_reserve(sfp, srp, size: dxfer_len);
1784 } else if (hp->flags & SG_FLAG_MMAP_IO) {
1785 res = -EBUSY; /* sfp->res_in_use == 1 */
1786 if (dxfer_len > rsv_schp->bufflen)
1787 res = -ENOMEM;
1788 mutex_unlock(lock: &sfp->f_mutex);
1789 return res;
1790 } else {
1791 res = sg_build_indirect(schp: req_schp, sfp, buff_size: dxfer_len);
1792 if (res) {
1793 mutex_unlock(lock: &sfp->f_mutex);
1794 return res;
1795 }
1796 }
1797 mutex_unlock(lock: &sfp->f_mutex);
1798
1799 md->pages = req_schp->pages;
1800 md->page_order = req_schp->page_order;
1801 md->nr_entries = req_schp->k_use_sg;
1802 md->offset = 0;
1803 md->null_mapped = hp->dxferp ? 0 : 1;
1804 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1805 md->from_user = 1;
1806 else
1807 md->from_user = 0;
1808 }
1809
1810 res = blk_rq_map_user_io(rq, md, hp->dxferp, hp->dxfer_len,
1811 GFP_ATOMIC, iov_count, iov_count, 1, rw);
1812 if (!res) {
1813 srp->bio = rq->bio;
1814
1815 if (!md) {
1816 req_schp->dio_in_use = 1;
1817 hp->info |= SG_INFO_DIRECT_IO;
1818 }
1819 }
1820 return res;
1821}
1822
1823static int
1824sg_finish_rem_req(Sg_request *srp)
1825{
1826 int ret = 0;
1827
1828 Sg_fd *sfp = srp->parentfp;
1829 Sg_scatter_hold *req_schp = &srp->data;
1830
1831 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1832 "sg_finish_rem_req: res_used=%d\n",
1833 (int) srp->res_used));
1834 if (srp->bio)
1835 ret = blk_rq_unmap_user(srp->bio);
1836
1837 if (srp->rq)
1838 blk_mq_free_request(rq: srp->rq);
1839
1840 if (srp->res_used)
1841 sg_unlink_reserve(sfp, srp);
1842 else
1843 sg_remove_scat(sfp, schp: req_schp);
1844
1845 return ret;
1846}
1847
1848static int
1849sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1850{
1851 int sg_bufflen = tablesize * sizeof(struct page *);
1852 gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1853
1854 schp->pages = kzalloc(sg_bufflen, gfp_flags);
1855 if (!schp->pages)
1856 return -ENOMEM;
1857 schp->sglist_len = sg_bufflen;
1858 return tablesize; /* number of scat_gath elements allocated */
1859}
1860
1861static int
1862sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1863{
1864 int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1865 int sg_tablesize = sfp->parentdp->sg_tablesize;
1866 int blk_size = buff_size, order;
1867 gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
1868
1869 if (blk_size < 0)
1870 return -EFAULT;
1871 if (0 == blk_size)
1872 ++blk_size; /* don't know why */
1873 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1874 blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1875 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1876 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1877 buff_size, blk_size));
1878
1879 /* N.B. ret_sz carried into this block ... */
1880 mx_sc_elems = sg_build_sgat(schp, sfp, tablesize: sg_tablesize);
1881 if (mx_sc_elems < 0)
1882 return mx_sc_elems; /* most likely -ENOMEM */
1883
1884 num = scatter_elem_sz;
1885 if (unlikely(num != scatter_elem_sz_prev)) {
1886 if (num < PAGE_SIZE) {
1887 scatter_elem_sz = PAGE_SIZE;
1888 scatter_elem_sz_prev = PAGE_SIZE;
1889 } else
1890 scatter_elem_sz_prev = num;
1891 }
1892
1893 order = get_order(size: num);
1894retry:
1895 ret_sz = 1 << (PAGE_SHIFT + order);
1896
1897 for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1898 k++, rem_sz -= ret_sz) {
1899
1900 num = (rem_sz > scatter_elem_sz_prev) ?
1901 scatter_elem_sz_prev : rem_sz;
1902
1903 schp->pages[k] = alloc_pages(gfp_mask, order);
1904 if (!schp->pages[k])
1905 goto out;
1906
1907 if (num == scatter_elem_sz_prev) {
1908 if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1909 scatter_elem_sz = ret_sz;
1910 scatter_elem_sz_prev = ret_sz;
1911 }
1912 }
1913
1914 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1915 "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1916 k, num, ret_sz));
1917 } /* end of for loop */
1918
1919 schp->page_order = order;
1920 schp->k_use_sg = k;
1921 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1922 "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1923 k, rem_sz));
1924
1925 schp->bufflen = blk_size;
1926 if (rem_sz > 0) /* must have failed */
1927 return -ENOMEM;
1928 return 0;
1929out:
1930 for (i = 0; i < k; i++)
1931 __free_pages(page: schp->pages[i], order);
1932
1933 if (--order >= 0)
1934 goto retry;
1935
1936 return -ENOMEM;
1937}
1938
1939static void
1940sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1941{
1942 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1943 "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1944 if (schp->pages && schp->sglist_len > 0) {
1945 if (!schp->dio_in_use) {
1946 int k;
1947
1948 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1949 SCSI_LOG_TIMEOUT(5,
1950 sg_printk(KERN_INFO, sfp->parentdp,
1951 "sg_remove_scat: k=%d, pg=0x%p\n",
1952 k, schp->pages[k]));
1953 __free_pages(page: schp->pages[k], order: schp->page_order);
1954 }
1955
1956 kfree(objp: schp->pages);
1957 }
1958 }
1959 memset(s: schp, c: 0, n: sizeof (*schp));
1960}
1961
1962static int
1963sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1964{
1965 Sg_scatter_hold *schp = &srp->data;
1966 int k, num;
1967
1968 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1969 "sg_read_oxfer: num_read_xfer=%d\n",
1970 num_read_xfer));
1971 if ((!outp) || (num_read_xfer <= 0))
1972 return 0;
1973
1974 num = 1 << (PAGE_SHIFT + schp->page_order);
1975 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1976 if (num > num_read_xfer) {
1977 if (copy_to_user(to: outp, page_address(schp->pages[k]),
1978 n: num_read_xfer))
1979 return -EFAULT;
1980 break;
1981 } else {
1982 if (copy_to_user(to: outp, page_address(schp->pages[k]),
1983 n: num))
1984 return -EFAULT;
1985 num_read_xfer -= num;
1986 if (num_read_xfer <= 0)
1987 break;
1988 outp += num;
1989 }
1990 }
1991
1992 return 0;
1993}
1994
1995static void
1996sg_build_reserve(Sg_fd * sfp, int req_size)
1997{
1998 Sg_scatter_hold *schp = &sfp->reserve;
1999
2000 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2001 "sg_build_reserve: req_size=%d\n", req_size));
2002 do {
2003 if (req_size < PAGE_SIZE)
2004 req_size = PAGE_SIZE;
2005 if (0 == sg_build_indirect(schp, sfp, buff_size: req_size))
2006 return;
2007 else
2008 sg_remove_scat(sfp, schp);
2009 req_size >>= 1; /* divide by 2 */
2010 } while (req_size > (PAGE_SIZE / 2));
2011}
2012
2013static void
2014sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2015{
2016 Sg_scatter_hold *req_schp = &srp->data;
2017 Sg_scatter_hold *rsv_schp = &sfp->reserve;
2018 int k, num, rem;
2019
2020 srp->res_used = 1;
2021 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2022 "sg_link_reserve: size=%d\n", size));
2023 rem = size;
2024
2025 num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
2026 for (k = 0; k < rsv_schp->k_use_sg; k++) {
2027 if (rem <= num) {
2028 req_schp->k_use_sg = k + 1;
2029 req_schp->sglist_len = rsv_schp->sglist_len;
2030 req_schp->pages = rsv_schp->pages;
2031
2032 req_schp->bufflen = size;
2033 req_schp->page_order = rsv_schp->page_order;
2034 break;
2035 } else
2036 rem -= num;
2037 }
2038
2039 if (k >= rsv_schp->k_use_sg)
2040 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2041 "sg_link_reserve: BAD size\n"));
2042}
2043
2044static void
2045sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2046{
2047 Sg_scatter_hold *req_schp = &srp->data;
2048
2049 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2050 "sg_unlink_reserve: req->k_use_sg=%d\n",
2051 (int) req_schp->k_use_sg));
2052 req_schp->k_use_sg = 0;
2053 req_schp->bufflen = 0;
2054 req_schp->pages = NULL;
2055 req_schp->page_order = 0;
2056 req_schp->sglist_len = 0;
2057 srp->res_used = 0;
2058 /* Called without mutex lock to avoid deadlock */
2059 sfp->res_in_use = 0;
2060}
2061
2062static Sg_request *
2063sg_get_rq_mark(Sg_fd * sfp, int pack_id, bool *busy)
2064{
2065 Sg_request *resp;
2066 unsigned long iflags;
2067
2068 *busy = false;
2069 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2070 list_for_each_entry(resp, &sfp->rq_list, entry) {
2071 /* look for requests that are not SG_IO owned */
2072 if ((!resp->sg_io_owned) &&
2073 ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2074 switch (resp->done) {
2075 case 0: /* request active */
2076 *busy = true;
2077 break;
2078 case 1: /* request done; response ready to return */
2079 resp->done = 2; /* guard against other readers */
2080 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2081 return resp;
2082 case 2: /* response already being returned */
2083 break;
2084 }
2085 }
2086 }
2087 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2088 return NULL;
2089}
2090
2091/* always adds to end of list */
2092static Sg_request *
2093sg_add_request(Sg_fd * sfp)
2094{
2095 int k;
2096 unsigned long iflags;
2097 Sg_request *rp = sfp->req_arr;
2098
2099 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2100 if (!list_empty(head: &sfp->rq_list)) {
2101 if (!sfp->cmd_q)
2102 goto out_unlock;
2103
2104 for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2105 if (!rp->parentfp)
2106 break;
2107 }
2108 if (k >= SG_MAX_QUEUE)
2109 goto out_unlock;
2110 }
2111 memset(s: rp, c: 0, n: sizeof (Sg_request));
2112 rp->parentfp = sfp;
2113 rp->header.duration = jiffies_to_msecs(j: jiffies);
2114 list_add_tail(new: &rp->entry, head: &sfp->rq_list);
2115 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2116 return rp;
2117out_unlock:
2118 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2119 return NULL;
2120}
2121
2122/* Return of 1 for found; 0 for not found */
2123static int
2124sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2125{
2126 unsigned long iflags;
2127 int res = 0;
2128
2129 if (!sfp || !srp || list_empty(head: &sfp->rq_list))
2130 return res;
2131 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2132 if (!list_empty(head: &srp->entry)) {
2133 list_del(entry: &srp->entry);
2134 srp->parentfp = NULL;
2135 res = 1;
2136 }
2137 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2138
2139 /*
2140 * If the device is detaching, wakeup any readers in case we just
2141 * removed the last response, which would leave nothing for them to
2142 * return other than -ENODEV.
2143 */
2144 if (unlikely(atomic_read(&sfp->parentdp->detaching)))
2145 wake_up_interruptible_all(&sfp->read_wait);
2146
2147 return res;
2148}
2149
2150static Sg_fd *
2151sg_add_sfp(Sg_device * sdp)
2152{
2153 Sg_fd *sfp;
2154 unsigned long iflags;
2155 int bufflen;
2156
2157 sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2158 if (!sfp)
2159 return ERR_PTR(error: -ENOMEM);
2160
2161 init_waitqueue_head(&sfp->read_wait);
2162 rwlock_init(&sfp->rq_list_lock);
2163 INIT_LIST_HEAD(list: &sfp->rq_list);
2164 kref_init(kref: &sfp->f_ref);
2165 mutex_init(&sfp->f_mutex);
2166 sfp->timeout = SG_DEFAULT_TIMEOUT;
2167 sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2168 sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2169 sfp->cmd_q = SG_DEF_COMMAND_Q;
2170 sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2171 sfp->parentdp = sdp;
2172 write_lock_irqsave(&sdp->sfd_lock, iflags);
2173 if (atomic_read(v: &sdp->detaching)) {
2174 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2175 kfree(objp: sfp);
2176 return ERR_PTR(error: -ENODEV);
2177 }
2178 list_add_tail(new: &sfp->sfd_siblings, head: &sdp->sfds);
2179 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2180 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2181 "sg_add_sfp: sfp=0x%p\n", sfp));
2182 if (unlikely(sg_big_buff != def_reserved_size))
2183 sg_big_buff = def_reserved_size;
2184
2185 bufflen = min_t(int, sg_big_buff,
2186 max_sectors_bytes(sdp->device->request_queue));
2187 sg_build_reserve(sfp, req_size: bufflen);
2188 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2189 "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2190 sfp->reserve.bufflen,
2191 sfp->reserve.k_use_sg));
2192
2193 kref_get(kref: &sdp->d_ref);
2194 __module_get(THIS_MODULE);
2195 return sfp;
2196}
2197
2198static void
2199sg_remove_sfp_usercontext(struct work_struct *work)
2200{
2201 struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2202 struct sg_device *sdp = sfp->parentdp;
2203 struct scsi_device *device = sdp->device;
2204 Sg_request *srp;
2205 unsigned long iflags;
2206
2207 /* Cleanup any responses which were never read(). */
2208 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2209 while (!list_empty(head: &sfp->rq_list)) {
2210 srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2211 sg_finish_rem_req(srp);
2212 list_del(entry: &srp->entry);
2213 srp->parentfp = NULL;
2214 }
2215 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2216
2217 if (sfp->reserve.bufflen > 0) {
2218 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2219 "sg_remove_sfp: bufflen=%d, k_use_sg=%d\n",
2220 (int) sfp->reserve.bufflen,
2221 (int) sfp->reserve.k_use_sg));
2222 sg_remove_scat(sfp, schp: &sfp->reserve);
2223 }
2224
2225 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2226 "sg_remove_sfp: sfp=0x%p\n", sfp));
2227 kfree(objp: sfp);
2228
2229 kref_put(kref: &sdp->d_ref, release: sg_device_destroy);
2230 scsi_device_put(device);
2231 module_put(THIS_MODULE);
2232}
2233
2234static void
2235sg_remove_sfp(struct kref *kref)
2236{
2237 struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2238 struct sg_device *sdp = sfp->parentdp;
2239 unsigned long iflags;
2240
2241 write_lock_irqsave(&sdp->sfd_lock, iflags);
2242 list_del(entry: &sfp->sfd_siblings);
2243 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2244
2245 INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2246 schedule_work(work: &sfp->ew.work);
2247}
2248
2249#ifdef CONFIG_SCSI_PROC_FS
2250static int
2251sg_idr_max_id(int id, void *p, void *data)
2252{
2253 int *k = data;
2254
2255 if (*k < id)
2256 *k = id;
2257
2258 return 0;
2259}
2260
2261static int
2262sg_last_dev(void)
2263{
2264 int k = -1;
2265 unsigned long iflags;
2266
2267 read_lock_irqsave(&sg_index_lock, iflags);
2268 idr_for_each(&sg_index_idr, fn: sg_idr_max_id, data: &k);
2269 read_unlock_irqrestore(&sg_index_lock, iflags);
2270 return k + 1; /* origin 1 */
2271}
2272#endif
2273
2274/* must be called with sg_index_lock held */
2275static Sg_device *sg_lookup_dev(int dev)
2276{
2277 return idr_find(&sg_index_idr, id: dev);
2278}
2279
2280static Sg_device *
2281sg_get_dev(int dev)
2282{
2283 struct sg_device *sdp;
2284 unsigned long flags;
2285
2286 read_lock_irqsave(&sg_index_lock, flags);
2287 sdp = sg_lookup_dev(dev);
2288 if (!sdp)
2289 sdp = ERR_PTR(error: -ENXIO);
2290 else if (atomic_read(v: &sdp->detaching)) {
2291 /* If sdp->detaching, then the refcount may already be 0, in
2292 * which case it would be a bug to do kref_get().
2293 */
2294 sdp = ERR_PTR(error: -ENODEV);
2295 } else
2296 kref_get(kref: &sdp->d_ref);
2297 read_unlock_irqrestore(&sg_index_lock, flags);
2298
2299 return sdp;
2300}
2301
2302#ifdef CONFIG_SCSI_PROC_FS
2303static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2304
2305static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2306static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2307 size_t count, loff_t *off);
2308static const struct proc_ops adio_proc_ops = {
2309 .proc_open = sg_proc_single_open_adio,
2310 .proc_read = seq_read,
2311 .proc_lseek = seq_lseek,
2312 .proc_write = sg_proc_write_adio,
2313 .proc_release = single_release,
2314};
2315
2316static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2317static ssize_t sg_proc_write_dressz(struct file *filp,
2318 const char __user *buffer, size_t count, loff_t *off);
2319static const struct proc_ops dressz_proc_ops = {
2320 .proc_open = sg_proc_single_open_dressz,
2321 .proc_read = seq_read,
2322 .proc_lseek = seq_lseek,
2323 .proc_write = sg_proc_write_dressz,
2324 .proc_release = single_release,
2325};
2326
2327static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2328static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2329static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2330static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2331static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2332static void dev_seq_stop(struct seq_file *s, void *v);
2333static const struct seq_operations dev_seq_ops = {
2334 .start = dev_seq_start,
2335 .next = dev_seq_next,
2336 .stop = dev_seq_stop,
2337 .show = sg_proc_seq_show_dev,
2338};
2339
2340static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2341static const struct seq_operations devstrs_seq_ops = {
2342 .start = dev_seq_start,
2343 .next = dev_seq_next,
2344 .stop = dev_seq_stop,
2345 .show = sg_proc_seq_show_devstrs,
2346};
2347
2348static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2349static const struct seq_operations debug_seq_ops = {
2350 .start = dev_seq_start,
2351 .next = dev_seq_next,
2352 .stop = dev_seq_stop,
2353 .show = sg_proc_seq_show_debug,
2354};
2355
2356static int
2357sg_proc_init(void)
2358{
2359 struct proc_dir_entry *p;
2360
2361 p = proc_mkdir("scsi/sg", NULL);
2362 if (!p)
2363 return 1;
2364
2365 proc_create(name: "allow_dio", S_IRUGO | S_IWUSR, parent: p, proc_ops: &adio_proc_ops);
2366 proc_create_seq("debug", S_IRUGO, p, &debug_seq_ops);
2367 proc_create(name: "def_reserved_size", S_IRUGO | S_IWUSR, parent: p, proc_ops: &dressz_proc_ops);
2368 proc_create_single("device_hdr", S_IRUGO, p, sg_proc_seq_show_devhdr);
2369 proc_create_seq("devices", S_IRUGO, p, &dev_seq_ops);
2370 proc_create_seq("device_strs", S_IRUGO, p, &devstrs_seq_ops);
2371 proc_create_single("version", S_IRUGO, p, sg_proc_seq_show_version);
2372 return 0;
2373}
2374
2375
2376static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2377{
2378 seq_printf(m: s, fmt: "%d\n", *((int *)s->private));
2379 return 0;
2380}
2381
2382static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2383{
2384 return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2385}
2386
2387static ssize_t
2388sg_proc_write_adio(struct file *filp, const char __user *buffer,
2389 size_t count, loff_t *off)
2390{
2391 int err;
2392 unsigned long num;
2393
2394 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2395 return -EACCES;
2396 err = kstrtoul_from_user(s: buffer, count, base: 0, res: &num);
2397 if (err)
2398 return err;
2399 sg_allow_dio = num ? 1 : 0;
2400 return count;
2401}
2402
2403static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2404{
2405 return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2406}
2407
2408static ssize_t
2409sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2410 size_t count, loff_t *off)
2411{
2412 int err;
2413 unsigned long k = ULONG_MAX;
2414
2415 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2416 return -EACCES;
2417
2418 err = kstrtoul_from_user(s: buffer, count, base: 0, res: &k);
2419 if (err)
2420 return err;
2421 if (k <= 1048576) { /* limit "big buff" to 1 MB */
2422 sg_big_buff = k;
2423 return count;
2424 }
2425 return -ERANGE;
2426}
2427
2428static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2429{
2430 seq_printf(m: s, fmt: "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2431 sg_version_date);
2432 return 0;
2433}
2434
2435static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2436{
2437 seq_puts(m: s, s: "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2438 return 0;
2439}
2440
2441struct sg_proc_deviter {
2442 loff_t index;
2443 size_t max;
2444};
2445
2446static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2447{
2448 struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2449
2450 s->private = it;
2451 if (! it)
2452 return NULL;
2453
2454 it->index = *pos;
2455 it->max = sg_last_dev();
2456 if (it->index >= it->max)
2457 return NULL;
2458 return it;
2459}
2460
2461static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2462{
2463 struct sg_proc_deviter * it = s->private;
2464
2465 *pos = ++it->index;
2466 return (it->index < it->max) ? it : NULL;
2467}
2468
2469static void dev_seq_stop(struct seq_file *s, void *v)
2470{
2471 kfree(objp: s->private);
2472}
2473
2474static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2475{
2476 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2477 Sg_device *sdp;
2478 struct scsi_device *scsidp;
2479 unsigned long iflags;
2480
2481 read_lock_irqsave(&sg_index_lock, iflags);
2482 sdp = it ? sg_lookup_dev(dev: it->index) : NULL;
2483 if ((NULL == sdp) || (NULL == sdp->device) ||
2484 (atomic_read(v: &sdp->detaching)))
2485 seq_puts(m: s, s: "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2486 else {
2487 scsidp = sdp->device;
2488 seq_printf(m: s, fmt: "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2489 scsidp->host->host_no, scsidp->channel,
2490 scsidp->id, scsidp->lun, (int) scsidp->type,
2491 1,
2492 (int) scsidp->queue_depth,
2493 (int) scsi_device_busy(sdev: scsidp),
2494 (int) scsi_device_online(sdev: scsidp));
2495 }
2496 read_unlock_irqrestore(&sg_index_lock, iflags);
2497 return 0;
2498}
2499
2500static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2501{
2502 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2503 Sg_device *sdp;
2504 struct scsi_device *scsidp;
2505 unsigned long iflags;
2506
2507 read_lock_irqsave(&sg_index_lock, iflags);
2508 sdp = it ? sg_lookup_dev(dev: it->index) : NULL;
2509 scsidp = sdp ? sdp->device : NULL;
2510 if (sdp && scsidp && (!atomic_read(v: &sdp->detaching)))
2511 seq_printf(m: s, fmt: "%8.8s\t%16.16s\t%4.4s\n",
2512 scsidp->vendor, scsidp->model, scsidp->rev);
2513 else
2514 seq_puts(m: s, s: "<no active device>\n");
2515 read_unlock_irqrestore(&sg_index_lock, iflags);
2516 return 0;
2517}
2518
2519/* must be called while holding sg_index_lock */
2520static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2521{
2522 int k, new_interface, blen, usg;
2523 Sg_request *srp;
2524 Sg_fd *fp;
2525 const sg_io_hdr_t *hp;
2526 const char * cp;
2527 unsigned int ms;
2528
2529 k = 0;
2530 list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2531 k++;
2532 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2533 seq_printf(m: s, fmt: " FD(%d): timeout=%dms bufflen=%d "
2534 "(res)sgat=%d low_dma=%d\n", k,
2535 jiffies_to_msecs(j: fp->timeout),
2536 fp->reserve.bufflen,
2537 (int) fp->reserve.k_use_sg, 0);
2538 seq_printf(m: s, fmt: " cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2539 (int) fp->cmd_q, (int) fp->force_packid,
2540 (int) fp->keep_orphan);
2541 list_for_each_entry(srp, &fp->rq_list, entry) {
2542 hp = &srp->header;
2543 new_interface = (hp->interface_id == '\0') ? 0 : 1;
2544 if (srp->res_used) {
2545 if (new_interface &&
2546 (SG_FLAG_MMAP_IO & hp->flags))
2547 cp = " mmap>> ";
2548 else
2549 cp = " rb>> ";
2550 } else {
2551 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2552 cp = " dio>> ";
2553 else
2554 cp = " ";
2555 }
2556 seq_puts(m: s, s: cp);
2557 blen = srp->data.bufflen;
2558 usg = srp->data.k_use_sg;
2559 seq_puts(m: s, s: srp->done ?
2560 ((1 == srp->done) ? "rcv:" : "fin:")
2561 : "act:");
2562 seq_printf(m: s, fmt: " id=%d blen=%d",
2563 srp->header.pack_id, blen);
2564 if (srp->done)
2565 seq_printf(m: s, fmt: " dur=%d", hp->duration);
2566 else {
2567 ms = jiffies_to_msecs(j: jiffies);
2568 seq_printf(m: s, fmt: " t_o/elap=%d/%d",
2569 (new_interface ? hp->timeout :
2570 jiffies_to_msecs(j: fp->timeout)),
2571 (ms > hp->duration ? ms - hp->duration : 0));
2572 }
2573 seq_printf(m: s, fmt: "ms sgat=%d op=0x%02x\n", usg,
2574 (int) srp->data.cmd_opcode);
2575 }
2576 if (list_empty(head: &fp->rq_list))
2577 seq_puts(m: s, s: " No requests active\n");
2578 read_unlock(&fp->rq_list_lock);
2579 }
2580}
2581
2582static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2583{
2584 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2585 Sg_device *sdp;
2586 unsigned long iflags;
2587
2588 if (it && (0 == it->index))
2589 seq_printf(m: s, fmt: "max_active_device=%d def_reserved_size=%d\n",
2590 (int)it->max, sg_big_buff);
2591
2592 read_lock_irqsave(&sg_index_lock, iflags);
2593 sdp = it ? sg_lookup_dev(dev: it->index) : NULL;
2594 if (NULL == sdp)
2595 goto skip;
2596 read_lock(&sdp->sfd_lock);
2597 if (!list_empty(head: &sdp->sfds)) {
2598 seq_printf(m: s, fmt: " >>> device=%s ", sdp->name);
2599 if (atomic_read(v: &sdp->detaching))
2600 seq_puts(m: s, s: "detaching pending close ");
2601 else if (sdp->device) {
2602 struct scsi_device *scsidp = sdp->device;
2603
2604 seq_printf(m: s, fmt: "%d:%d:%d:%llu em=%d",
2605 scsidp->host->host_no,
2606 scsidp->channel, scsidp->id,
2607 scsidp->lun,
2608 scsidp->host->hostt->emulated);
2609 }
2610 seq_printf(m: s, fmt: " sg_tablesize=%d excl=%d open_cnt=%d\n",
2611 sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2612 sg_proc_debug_helper(s, sdp);
2613 }
2614 read_unlock(&sdp->sfd_lock);
2615skip:
2616 read_unlock_irqrestore(&sg_index_lock, iflags);
2617 return 0;
2618}
2619
2620#endif /* CONFIG_SCSI_PROC_FS */
2621
2622module_init(init_sg);
2623module_exit(exit_sg);
2624