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(&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(&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 retval = scsi_autopm_get_device(device);
311 if (retval)
312 goto sdp_put;
313
314 /* scsi_block_when_processing_errors() may block so bypass
315 * check if O_NONBLOCK. Permits SCSI commands to be issued
316 * during error recovery. Tread carefully. */
317 if (!((flags & O_NONBLOCK) ||
318 scsi_block_when_processing_errors(device))) {
319 retval = -ENXIO;
320 /* we are in error recovery for this device */
321 goto error_out;
322 }
323
324 mutex_lock(&sdp->open_rel_lock);
325 if (flags & O_NONBLOCK) {
326 if (flags & O_EXCL) {
327 if (sdp->open_cnt > 0) {
328 retval = -EBUSY;
329 goto error_mutex_locked;
330 }
331 } else {
332 if (sdp->exclude) {
333 retval = -EBUSY;
334 goto error_mutex_locked;
335 }
336 }
337 } else {
338 retval = open_wait(sdp, flags);
339 if (retval) /* -ERESTARTSYS or -ENODEV */
340 goto error_mutex_locked;
341 }
342
343 /* N.B. at this point we are holding the open_rel_lock */
344 if (flags & O_EXCL)
345 sdp->exclude = true;
346
347 if (sdp->open_cnt < 1) { /* no existing opens */
348 sdp->sgdebug = 0;
349 q = device->request_queue;
350 sdp->sg_tablesize = queue_max_segments(q);
351 }
352 sfp = sg_add_sfp(sdp);
353 if (IS_ERR(ptr: sfp)) {
354 retval = PTR_ERR(ptr: sfp);
355 goto out_undo;
356 }
357
358 filp->private_data = sfp;
359 sdp->open_cnt++;
360 mutex_unlock(lock: &sdp->open_rel_lock);
361
362 retval = 0;
363sg_put:
364 kref_put(kref: &sdp->d_ref, release: sg_device_destroy);
365 return retval;
366
367out_undo:
368 if (flags & O_EXCL) {
369 sdp->exclude = false; /* undo if error */
370 wake_up_interruptible(&sdp->open_wait);
371 }
372error_mutex_locked:
373 mutex_unlock(lock: &sdp->open_rel_lock);
374error_out:
375 scsi_autopm_put_device(device);
376sdp_put:
377 kref_put(kref: &sdp->d_ref, release: sg_device_destroy);
378 scsi_device_put(device);
379 return retval;
380}
381
382/* Release resources associated with a successful sg_open()
383 * Returns 0 on success, else a negated errno value */
384static int
385sg_release(struct inode *inode, struct file *filp)
386{
387 Sg_device *sdp;
388 Sg_fd *sfp;
389
390 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
391 return -ENXIO;
392 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
393
394 mutex_lock(&sdp->open_rel_lock);
395 scsi_autopm_put_device(sdp->device);
396 kref_put(kref: &sfp->f_ref, release: sg_remove_sfp);
397 sdp->open_cnt--;
398
399 /* possibly many open()s waiting on exlude clearing, start many;
400 * only open(O_EXCL)s wait on 0==open_cnt so only start one */
401 if (sdp->exclude) {
402 sdp->exclude = false;
403 wake_up_interruptible_all(&sdp->open_wait);
404 } else if (0 == sdp->open_cnt) {
405 wake_up_interruptible(&sdp->open_wait);
406 }
407 mutex_unlock(lock: &sdp->open_rel_lock);
408 return 0;
409}
410
411static int get_sg_io_pack_id(int *pack_id, void __user *buf, size_t count)
412{
413 struct sg_header __user *old_hdr = buf;
414 int reply_len;
415
416 if (count >= SZ_SG_HEADER) {
417 /* negative reply_len means v3 format, otherwise v1/v2 */
418 if (get_user(reply_len, &old_hdr->reply_len))
419 return -EFAULT;
420
421 if (reply_len >= 0)
422 return get_user(*pack_id, &old_hdr->pack_id);
423
424 if (in_compat_syscall() &&
425 count >= sizeof(struct compat_sg_io_hdr)) {
426 struct compat_sg_io_hdr __user *hp = buf;
427
428 return get_user(*pack_id, &hp->pack_id);
429 }
430
431 if (count >= sizeof(struct sg_io_hdr)) {
432 struct sg_io_hdr __user *hp = buf;
433
434 return get_user(*pack_id, &hp->pack_id);
435 }
436 }
437
438 /* no valid header was passed, so ignore the pack_id */
439 *pack_id = -1;
440 return 0;
441}
442
443static ssize_t
444sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
445{
446 Sg_device *sdp;
447 Sg_fd *sfp;
448 Sg_request *srp;
449 int req_pack_id = -1;
450 bool busy;
451 sg_io_hdr_t *hp;
452 struct sg_header *old_hdr;
453 int retval;
454
455 /*
456 * This could cause a response to be stranded. Close the associated
457 * file descriptor to free up any resources being held.
458 */
459 retval = sg_check_file_access(filp, caller: __func__);
460 if (retval)
461 return retval;
462
463 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
464 return -ENXIO;
465 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
466 "sg_read: count=%d\n", (int) count));
467
468 if (sfp->force_packid)
469 retval = get_sg_io_pack_id(pack_id: &req_pack_id, buf, count);
470 if (retval)
471 return retval;
472
473 srp = sg_get_rq_mark(sfp, pack_id: req_pack_id, busy: &busy);
474 if (!srp) { /* now wait on packet to arrive */
475 if (filp->f_flags & O_NONBLOCK)
476 return -EAGAIN;
477 retval = wait_event_interruptible(sfp->read_wait,
478 ((srp = sg_get_rq_mark(sfp, req_pack_id, &busy)) ||
479 (!busy && atomic_read(&sdp->detaching))));
480 if (!srp)
481 /* signal or detaching */
482 return retval ? retval : -ENODEV;
483 }
484 if (srp->header.interface_id != '\0')
485 return sg_new_read(sfp, buf, count, srp);
486
487 hp = &srp->header;
488 old_hdr = kzalloc(SZ_SG_HEADER, GFP_KERNEL);
489 if (!old_hdr)
490 return -ENOMEM;
491
492 old_hdr->reply_len = (int) hp->timeout;
493 old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
494 old_hdr->pack_id = hp->pack_id;
495 old_hdr->twelve_byte =
496 ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
497 old_hdr->target_status = hp->masked_status;
498 old_hdr->host_status = hp->host_status;
499 old_hdr->driver_status = hp->driver_status;
500 if ((CHECK_CONDITION & hp->masked_status) ||
501 (srp->sense_b[0] & 0x70) == 0x70) {
502 old_hdr->driver_status = DRIVER_SENSE;
503 memcpy(old_hdr->sense_buffer, srp->sense_b,
504 sizeof (old_hdr->sense_buffer));
505 }
506 switch (hp->host_status) {
507 /* This setup of 'result' is for backward compatibility and is best
508 ignored by the user who should use target, host + driver status */
509 case DID_OK:
510 case DID_PASSTHROUGH:
511 case DID_SOFT_ERROR:
512 old_hdr->result = 0;
513 break;
514 case DID_NO_CONNECT:
515 case DID_BUS_BUSY:
516 case DID_TIME_OUT:
517 old_hdr->result = EBUSY;
518 break;
519 case DID_BAD_TARGET:
520 case DID_ABORT:
521 case DID_PARITY:
522 case DID_RESET:
523 case DID_BAD_INTR:
524 old_hdr->result = EIO;
525 break;
526 case DID_ERROR:
527 old_hdr->result = (srp->sense_b[0] == 0 &&
528 hp->masked_status == GOOD) ? 0 : EIO;
529 break;
530 default:
531 old_hdr->result = EIO;
532 break;
533 }
534
535 /* Now copy the result back to the user buffer. */
536 if (count >= SZ_SG_HEADER) {
537 if (copy_to_user(to: buf, from: old_hdr, SZ_SG_HEADER)) {
538 retval = -EFAULT;
539 goto free_old_hdr;
540 }
541 buf += SZ_SG_HEADER;
542 if (count > old_hdr->reply_len)
543 count = old_hdr->reply_len;
544 if (count > SZ_SG_HEADER) {
545 if (sg_read_oxfer(srp, outp: buf, num_read_xfer: count - SZ_SG_HEADER)) {
546 retval = -EFAULT;
547 goto free_old_hdr;
548 }
549 }
550 } else
551 count = (old_hdr->result == 0) ? 0 : -EIO;
552 sg_finish_rem_req(srp);
553 sg_remove_request(sfp, srp);
554 retval = count;
555free_old_hdr:
556 kfree(objp: old_hdr);
557 return retval;
558}
559
560static ssize_t
561sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
562{
563 sg_io_hdr_t *hp = &srp->header;
564 int err = 0, err2;
565 int len;
566
567 if (in_compat_syscall()) {
568 if (count < sizeof(struct compat_sg_io_hdr)) {
569 err = -EINVAL;
570 goto err_out;
571 }
572 } else if (count < SZ_SG_IO_HDR) {
573 err = -EINVAL;
574 goto err_out;
575 }
576 hp->sb_len_wr = 0;
577 if ((hp->mx_sb_len > 0) && hp->sbp) {
578 if ((CHECK_CONDITION & hp->masked_status) ||
579 (srp->sense_b[0] & 0x70) == 0x70) {
580 int sb_len = SCSI_SENSE_BUFFERSIZE;
581 sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
582 len = 8 + (int) srp->sense_b[7]; /* Additional sense length field */
583 len = (len > sb_len) ? sb_len : len;
584 if (copy_to_user(to: hp->sbp, from: srp->sense_b, n: len)) {
585 err = -EFAULT;
586 goto err_out;
587 }
588 hp->driver_status = DRIVER_SENSE;
589 hp->sb_len_wr = len;
590 }
591 }
592 if (hp->masked_status || hp->host_status || hp->driver_status)
593 hp->info |= SG_INFO_CHECK;
594 err = put_sg_io_hdr(hdr: hp, argp: buf);
595err_out:
596 err2 = sg_finish_rem_req(srp);
597 sg_remove_request(sfp, srp);
598 return err ? : err2 ? : count;
599}
600
601static ssize_t
602sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
603{
604 int mxsize, cmd_size, k;
605 int input_size, blocking;
606 unsigned char opcode;
607 Sg_device *sdp;
608 Sg_fd *sfp;
609 Sg_request *srp;
610 struct sg_header old_hdr;
611 sg_io_hdr_t *hp;
612 unsigned char cmnd[SG_MAX_CDB_SIZE];
613 int retval;
614
615 retval = sg_check_file_access(filp, caller: __func__);
616 if (retval)
617 return retval;
618
619 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
620 return -ENXIO;
621 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
622 "sg_write: count=%d\n", (int) count));
623 if (atomic_read(v: &sdp->detaching))
624 return -ENODEV;
625 if (!((filp->f_flags & O_NONBLOCK) ||
626 scsi_block_when_processing_errors(sdp->device)))
627 return -ENXIO;
628
629 if (count < SZ_SG_HEADER)
630 return -EIO;
631 if (copy_from_user(to: &old_hdr, from: buf, SZ_SG_HEADER))
632 return -EFAULT;
633 blocking = !(filp->f_flags & O_NONBLOCK);
634 if (old_hdr.reply_len < 0)
635 return sg_new_write(sfp, file: filp, buf, count,
636 blocking, read_only: 0, sg_io_owned: 0, NULL);
637 if (count < (SZ_SG_HEADER + 6))
638 return -EIO; /* The minimum scsi command length is 6 bytes. */
639
640 buf += SZ_SG_HEADER;
641 if (get_user(opcode, buf))
642 return -EFAULT;
643
644 if (!(srp = sg_add_request(sfp))) {
645 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
646 "sg_write: queue full\n"));
647 return -EDOM;
648 }
649 mutex_lock(&sfp->f_mutex);
650 if (sfp->next_cmd_len > 0) {
651 cmd_size = sfp->next_cmd_len;
652 sfp->next_cmd_len = 0; /* reset so only this write() effected */
653 } else {
654 cmd_size = COMMAND_SIZE(opcode); /* based on SCSI command group */
655 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
656 cmd_size = 12;
657 }
658 mutex_unlock(lock: &sfp->f_mutex);
659 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
660 "sg_write: scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
661/* Determine buffer size. */
662 input_size = count - cmd_size;
663 mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
664 mxsize -= SZ_SG_HEADER;
665 input_size -= SZ_SG_HEADER;
666 if (input_size < 0) {
667 sg_remove_request(sfp, srp);
668 return -EIO; /* User did not pass enough bytes for this command. */
669 }
670 hp = &srp->header;
671 hp->interface_id = '\0'; /* indicator of old interface tunnelled */
672 hp->cmd_len = (unsigned char) cmd_size;
673 hp->iovec_count = 0;
674 hp->mx_sb_len = 0;
675 if (input_size > 0)
676 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
677 SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
678 else
679 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
680 hp->dxfer_len = mxsize;
681 if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
682 (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
683 hp->dxferp = (char __user *)buf + cmd_size;
684 else
685 hp->dxferp = NULL;
686 hp->sbp = NULL;
687 hp->timeout = old_hdr.reply_len; /* structure abuse ... */
688 hp->flags = input_size; /* structure abuse ... */
689 hp->pack_id = old_hdr.pack_id;
690 hp->usr_ptr = NULL;
691 if (copy_from_user(to: cmnd, from: buf, n: cmd_size)) {
692 sg_remove_request(sfp, srp);
693 return -EFAULT;
694 }
695 /*
696 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
697 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
698 * is a non-zero input_size, so emit a warning.
699 */
700 if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
701 printk_ratelimited(KERN_WARNING
702 "sg_write: data in/out %d/%d bytes "
703 "for SCSI command 0x%x-- guessing "
704 "data in;\n program %s not setting "
705 "count and/or reply_len properly\n",
706 old_hdr.reply_len - (int)SZ_SG_HEADER,
707 input_size, (unsigned int) cmnd[0],
708 current->comm);
709 }
710 k = sg_common_write(sfp, srp, cmnd, timeout: sfp->timeout, blocking);
711 return (k < 0) ? k : count;
712}
713
714static ssize_t
715sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
716 size_t count, int blocking, int read_only, int sg_io_owned,
717 Sg_request **o_srp)
718{
719 int k;
720 Sg_request *srp;
721 sg_io_hdr_t *hp;
722 unsigned char cmnd[SG_MAX_CDB_SIZE];
723 int timeout;
724 unsigned long ul_timeout;
725
726 if (count < SZ_SG_IO_HDR)
727 return -EINVAL;
728
729 sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
730 if (!(srp = sg_add_request(sfp))) {
731 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
732 "sg_new_write: queue full\n"));
733 return -EDOM;
734 }
735 srp->sg_io_owned = sg_io_owned;
736 hp = &srp->header;
737 if (get_sg_io_hdr(hdr: hp, argp: buf)) {
738 sg_remove_request(sfp, srp);
739 return -EFAULT;
740 }
741 if (hp->interface_id != 'S') {
742 sg_remove_request(sfp, srp);
743 return -ENOSYS;
744 }
745 if (hp->flags & SG_FLAG_MMAP_IO) {
746 if (hp->dxfer_len > sfp->reserve.bufflen) {
747 sg_remove_request(sfp, srp);
748 return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
749 }
750 if (hp->flags & SG_FLAG_DIRECT_IO) {
751 sg_remove_request(sfp, srp);
752 return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
753 }
754 if (sfp->res_in_use) {
755 sg_remove_request(sfp, srp);
756 return -EBUSY; /* reserve buffer already being used */
757 }
758 }
759 ul_timeout = msecs_to_jiffies(m: srp->header.timeout);
760 timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
761 if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
762 sg_remove_request(sfp, srp);
763 return -EMSGSIZE;
764 }
765 if (copy_from_user(to: cmnd, from: hp->cmdp, n: hp->cmd_len)) {
766 sg_remove_request(sfp, srp);
767 return -EFAULT;
768 }
769 if (read_only && sg_allow_access(filp: file, cmd: cmnd)) {
770 sg_remove_request(sfp, srp);
771 return -EPERM;
772 }
773 k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
774 if (k < 0)
775 return k;
776 if (o_srp)
777 *o_srp = srp;
778 return count;
779}
780
781static int
782sg_common_write(Sg_fd * sfp, Sg_request * srp,
783 unsigned char *cmnd, int timeout, int blocking)
784{
785 int k, at_head;
786 Sg_device *sdp = sfp->parentdp;
787 sg_io_hdr_t *hp = &srp->header;
788
789 srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
790 hp->status = 0;
791 hp->masked_status = 0;
792 hp->msg_status = 0;
793 hp->info = 0;
794 hp->host_status = 0;
795 hp->driver_status = 0;
796 hp->resid = 0;
797 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
798 "sg_common_write: scsi opcode=0x%02x, cmd_size=%d\n",
799 (int) cmnd[0], (int) hp->cmd_len));
800
801 if (hp->dxfer_len >= SZ_256M) {
802 sg_remove_request(sfp, srp);
803 return -EINVAL;
804 }
805
806 k = sg_start_req(srp, cmd: cmnd);
807 if (k) {
808 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
809 "sg_common_write: start_req err=%d\n", k));
810 sg_finish_rem_req(srp);
811 sg_remove_request(sfp, srp);
812 return k; /* probably out of space --> ENOMEM */
813 }
814 if (atomic_read(v: &sdp->detaching)) {
815 if (srp->bio) {
816 blk_mq_free_request(rq: srp->rq);
817 srp->rq = NULL;
818 }
819
820 sg_finish_rem_req(srp);
821 sg_remove_request(sfp, srp);
822 return -ENODEV;
823 }
824
825 hp->duration = jiffies_to_msecs(j: jiffies);
826 if (hp->interface_id != '\0' && /* v3 (or later) interface */
827 (SG_FLAG_Q_AT_TAIL & hp->flags))
828 at_head = 0;
829 else
830 at_head = 1;
831
832 srp->rq->timeout = timeout;
833 kref_get(kref: &sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
834 srp->rq->end_io = sg_rq_end_io;
835 blk_execute_rq_nowait(rq: srp->rq, at_head);
836 return 0;
837}
838
839static int srp_done(Sg_fd *sfp, Sg_request *srp)
840{
841 unsigned long flags;
842 int ret;
843
844 read_lock_irqsave(&sfp->rq_list_lock, flags);
845 ret = srp->done;
846 read_unlock_irqrestore(&sfp->rq_list_lock, flags);
847 return ret;
848}
849
850static int max_sectors_bytes(struct request_queue *q)
851{
852 unsigned int max_sectors = queue_max_sectors(q);
853
854 max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
855
856 return max_sectors << 9;
857}
858
859static void
860sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
861{
862 Sg_request *srp;
863 int val;
864 unsigned int ms;
865
866 val = 0;
867 list_for_each_entry(srp, &sfp->rq_list, entry) {
868 if (val >= SG_MAX_QUEUE)
869 break;
870 rinfo[val].req_state = srp->done + 1;
871 rinfo[val].problem =
872 srp->header.masked_status &
873 srp->header.host_status &
874 srp->header.driver_status;
875 if (srp->done)
876 rinfo[val].duration =
877 srp->header.duration;
878 else {
879 ms = jiffies_to_msecs(j: jiffies);
880 rinfo[val].duration =
881 (ms > srp->header.duration) ?
882 (ms - srp->header.duration) : 0;
883 }
884 rinfo[val].orphan = srp->orphan;
885 rinfo[val].sg_io_owned = srp->sg_io_owned;
886 rinfo[val].pack_id = srp->header.pack_id;
887 rinfo[val].usr_ptr = srp->header.usr_ptr;
888 val++;
889 }
890}
891
892#ifdef CONFIG_COMPAT
893struct compat_sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
894 char req_state;
895 char orphan;
896 char sg_io_owned;
897 char problem;
898 int pack_id;
899 compat_uptr_t usr_ptr;
900 unsigned int duration;
901 int unused;
902};
903
904static int put_compat_request_table(struct compat_sg_req_info __user *o,
905 struct sg_req_info *rinfo)
906{
907 int i;
908 for (i = 0; i < SG_MAX_QUEUE; i++) {
909 if (copy_to_user(to: o + i, from: rinfo + i, offsetof(sg_req_info_t, usr_ptr)) ||
910 put_user((uintptr_t)rinfo[i].usr_ptr, &o[i].usr_ptr) ||
911 put_user(rinfo[i].duration, &o[i].duration) ||
912 put_user(rinfo[i].unused, &o[i].unused))
913 return -EFAULT;
914 }
915 return 0;
916}
917#endif
918
919static long
920sg_ioctl_common(struct file *filp, Sg_device *sdp, Sg_fd *sfp,
921 unsigned int cmd_in, void __user *p)
922{
923 int __user *ip = p;
924 int result, val, read_only;
925 Sg_request *srp;
926 unsigned long iflags;
927
928 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
929 "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
930 read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
931
932 switch (cmd_in) {
933 case SG_IO:
934 if (atomic_read(v: &sdp->detaching))
935 return -ENODEV;
936 if (!scsi_block_when_processing_errors(sdp->device))
937 return -ENXIO;
938 result = sg_new_write(sfp, file: filp, buf: p, SZ_SG_IO_HDR,
939 blocking: 1, read_only, sg_io_owned: 1, o_srp: &srp);
940 if (result < 0)
941 return result;
942 result = wait_event_interruptible(sfp->read_wait,
943 srp_done(sfp, srp));
944 write_lock_irq(&sfp->rq_list_lock);
945 if (srp->done) {
946 srp->done = 2;
947 write_unlock_irq(&sfp->rq_list_lock);
948 result = sg_new_read(sfp, buf: p, SZ_SG_IO_HDR, srp);
949 return (result < 0) ? result : 0;
950 }
951 srp->orphan = 1;
952 write_unlock_irq(&sfp->rq_list_lock);
953 return result; /* -ERESTARTSYS because signal hit process */
954 case SG_SET_TIMEOUT:
955 result = get_user(val, ip);
956 if (result)
957 return result;
958 if (val < 0)
959 return -EIO;
960 if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
961 val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
962 INT_MAX);
963 sfp->timeout_user = val;
964 sfp->timeout = mult_frac(val, HZ, USER_HZ);
965
966 return 0;
967 case SG_GET_TIMEOUT: /* N.B. User receives timeout as return value */
968 /* strange ..., for backward compatibility */
969 return sfp->timeout_user;
970 case SG_SET_FORCE_LOW_DMA:
971 /*
972 * N.B. This ioctl never worked properly, but failed to
973 * return an error value. So returning '0' to keep compability
974 * with legacy applications.
975 */
976 return 0;
977 case SG_GET_LOW_DMA:
978 return put_user(0, ip);
979 case SG_GET_SCSI_ID:
980 {
981 sg_scsi_id_t v;
982
983 if (atomic_read(v: &sdp->detaching))
984 return -ENODEV;
985 memset(&v, 0, sizeof(v));
986 v.host_no = sdp->device->host->host_no;
987 v.channel = sdp->device->channel;
988 v.scsi_id = sdp->device->id;
989 v.lun = sdp->device->lun;
990 v.scsi_type = sdp->device->type;
991 v.h_cmd_per_lun = sdp->device->host->cmd_per_lun;
992 v.d_queue_depth = sdp->device->queue_depth;
993 if (copy_to_user(to: p, from: &v, n: sizeof(sg_scsi_id_t)))
994 return -EFAULT;
995 return 0;
996 }
997 case SG_SET_FORCE_PACK_ID:
998 result = get_user(val, ip);
999 if (result)
1000 return result;
1001 sfp->force_packid = val ? 1 : 0;
1002 return 0;
1003 case SG_GET_PACK_ID:
1004 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1005 list_for_each_entry(srp, &sfp->rq_list, entry) {
1006 if ((1 == srp->done) && (!srp->sg_io_owned)) {
1007 read_unlock_irqrestore(&sfp->rq_list_lock,
1008 iflags);
1009 return put_user(srp->header.pack_id, ip);
1010 }
1011 }
1012 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1013 return put_user(-1, ip);
1014 case SG_GET_NUM_WAITING:
1015 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1016 val = 0;
1017 list_for_each_entry(srp, &sfp->rq_list, entry) {
1018 if ((1 == srp->done) && (!srp->sg_io_owned))
1019 ++val;
1020 }
1021 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1022 return put_user(val, ip);
1023 case SG_GET_SG_TABLESIZE:
1024 return put_user(sdp->sg_tablesize, ip);
1025 case SG_SET_RESERVED_SIZE:
1026 result = get_user(val, ip);
1027 if (result)
1028 return result;
1029 if (val < 0)
1030 return -EINVAL;
1031 val = min_t(int, val,
1032 max_sectors_bytes(sdp->device->request_queue));
1033 mutex_lock(&sfp->f_mutex);
1034 if (val != sfp->reserve.bufflen) {
1035 if (sfp->mmap_called ||
1036 sfp->res_in_use) {
1037 mutex_unlock(lock: &sfp->f_mutex);
1038 return -EBUSY;
1039 }
1040
1041 sg_remove_scat(sfp, schp: &sfp->reserve);
1042 sg_build_reserve(sfp, req_size: val);
1043 }
1044 mutex_unlock(lock: &sfp->f_mutex);
1045 return 0;
1046 case SG_GET_RESERVED_SIZE:
1047 val = min_t(int, sfp->reserve.bufflen,
1048 max_sectors_bytes(sdp->device->request_queue));
1049 return put_user(val, ip);
1050 case SG_SET_COMMAND_Q:
1051 result = get_user(val, ip);
1052 if (result)
1053 return result;
1054 sfp->cmd_q = val ? 1 : 0;
1055 return 0;
1056 case SG_GET_COMMAND_Q:
1057 return put_user((int) sfp->cmd_q, ip);
1058 case SG_SET_KEEP_ORPHAN:
1059 result = get_user(val, ip);
1060 if (result)
1061 return result;
1062 sfp->keep_orphan = val;
1063 return 0;
1064 case SG_GET_KEEP_ORPHAN:
1065 return put_user((int) sfp->keep_orphan, ip);
1066 case SG_NEXT_CMD_LEN:
1067 result = get_user(val, ip);
1068 if (result)
1069 return result;
1070 if (val > SG_MAX_CDB_SIZE)
1071 return -ENOMEM;
1072 sfp->next_cmd_len = (val > 0) ? val : 0;
1073 return 0;
1074 case SG_GET_VERSION_NUM:
1075 return put_user(sg_version_num, ip);
1076 case SG_GET_ACCESS_COUNT:
1077 /* faked - we don't have a real access count anymore */
1078 val = (sdp->device ? 1 : 0);
1079 return put_user(val, ip);
1080 case SG_GET_REQUEST_TABLE:
1081 {
1082 sg_req_info_t *rinfo;
1083
1084 rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
1085 GFP_KERNEL);
1086 if (!rinfo)
1087 return -ENOMEM;
1088 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1089 sg_fill_request_table(sfp, rinfo);
1090 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1091 #ifdef CONFIG_COMPAT
1092 if (in_compat_syscall())
1093 result = put_compat_request_table(o: p, rinfo);
1094 else
1095 #endif
1096 result = copy_to_user(to: p, from: rinfo,
1097 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1098 result = result ? -EFAULT : 0;
1099 kfree(objp: rinfo);
1100 return result;
1101 }
1102 case SG_EMULATED_HOST:
1103 if (atomic_read(v: &sdp->detaching))
1104 return -ENODEV;
1105 return put_user(sdp->device->host->hostt->emulated, ip);
1106 case SCSI_IOCTL_SEND_COMMAND:
1107 if (atomic_read(v: &sdp->detaching))
1108 return -ENODEV;
1109 return scsi_ioctl(sdev: sdp->device, open_for_write: filp->f_mode & FMODE_WRITE,
1110 cmd: cmd_in, arg: p);
1111 case SG_SET_DEBUG:
1112 result = get_user(val, ip);
1113 if (result)
1114 return result;
1115 sdp->sgdebug = (char) val;
1116 return 0;
1117 case BLKSECTGET:
1118 return put_user(max_sectors_bytes(sdp->device->request_queue),
1119 ip);
1120 case BLKTRACESETUP:
1121 return blk_trace_setup(q: sdp->device->request_queue, name: sdp->name,
1122 MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1123 NULL, arg: p);
1124 case BLKTRACESTART:
1125 return blk_trace_startstop(q: sdp->device->request_queue, start: 1);
1126 case BLKTRACESTOP:
1127 return blk_trace_startstop(q: sdp->device->request_queue, start: 0);
1128 case BLKTRACETEARDOWN:
1129 return blk_trace_remove(q: sdp->device->request_queue);
1130 case SCSI_IOCTL_GET_IDLUN:
1131 case SCSI_IOCTL_GET_BUS_NUMBER:
1132 case SCSI_IOCTL_PROBE_HOST:
1133 case SG_GET_TRANSFORM:
1134 case SG_SCSI_RESET:
1135 if (atomic_read(v: &sdp->detaching))
1136 return -ENODEV;
1137 break;
1138 default:
1139 if (read_only)
1140 return -EPERM; /* don't know so take safe approach */
1141 break;
1142 }
1143
1144 result = scsi_ioctl_block_when_processing_errors(sdev: sdp->device,
1145 cmd: cmd_in, ndelay: filp->f_flags & O_NDELAY);
1146 if (result)
1147 return result;
1148
1149 return -ENOIOCTLCMD;
1150}
1151
1152static long
1153sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1154{
1155 void __user *p = (void __user *)arg;
1156 Sg_device *sdp;
1157 Sg_fd *sfp;
1158 int ret;
1159
1160 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1161 return -ENXIO;
1162
1163 ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
1164 if (ret != -ENOIOCTLCMD)
1165 return ret;
1166 return scsi_ioctl(sdev: sdp->device, open_for_write: filp->f_mode & FMODE_WRITE, cmd: cmd_in, arg: p);
1167}
1168
1169static __poll_t
1170sg_poll(struct file *filp, poll_table * wait)
1171{
1172 __poll_t res = 0;
1173 Sg_device *sdp;
1174 Sg_fd *sfp;
1175 Sg_request *srp;
1176 int count = 0;
1177 unsigned long iflags;
1178
1179 sfp = filp->private_data;
1180 if (!sfp)
1181 return EPOLLERR;
1182 sdp = sfp->parentdp;
1183 if (!sdp)
1184 return EPOLLERR;
1185 poll_wait(filp, wait_address: &sfp->read_wait, p: wait);
1186 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1187 list_for_each_entry(srp, &sfp->rq_list, entry) {
1188 /* if any read waiting, flag it */
1189 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1190 res = EPOLLIN | EPOLLRDNORM;
1191 ++count;
1192 }
1193 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1194
1195 if (atomic_read(v: &sdp->detaching))
1196 res |= EPOLLHUP;
1197 else if (!sfp->cmd_q) {
1198 if (0 == count)
1199 res |= EPOLLOUT | EPOLLWRNORM;
1200 } else if (count < SG_MAX_QUEUE)
1201 res |= EPOLLOUT | EPOLLWRNORM;
1202 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1203 "sg_poll: res=0x%x\n", (__force u32) res));
1204 return res;
1205}
1206
1207static int
1208sg_fasync(int fd, struct file *filp, int mode)
1209{
1210 Sg_device *sdp;
1211 Sg_fd *sfp;
1212
1213 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1214 return -ENXIO;
1215 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1216 "sg_fasync: mode=%d\n", mode));
1217
1218 return fasync_helper(fd, filp, mode, &sfp->async_qp);
1219}
1220
1221static vm_fault_t
1222sg_vma_fault(struct vm_fault *vmf)
1223{
1224 struct vm_area_struct *vma = vmf->vma;
1225 Sg_fd *sfp;
1226 unsigned long offset, len, sa;
1227 Sg_scatter_hold *rsv_schp;
1228 int k, length;
1229
1230 if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1231 return VM_FAULT_SIGBUS;
1232 rsv_schp = &sfp->reserve;
1233 offset = vmf->pgoff << PAGE_SHIFT;
1234 if (offset >= rsv_schp->bufflen)
1235 return VM_FAULT_SIGBUS;
1236 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1237 "sg_vma_fault: offset=%lu, scatg=%d\n",
1238 offset, rsv_schp->k_use_sg));
1239 sa = vma->vm_start;
1240 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1241 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1242 len = vma->vm_end - sa;
1243 len = (len < length) ? len : length;
1244 if (offset < len) {
1245 struct page *page = nth_page(rsv_schp->pages[k],
1246 offset >> PAGE_SHIFT);
1247 get_page(page); /* increment page count */
1248 vmf->page = page;
1249 return 0; /* success */
1250 }
1251 sa += len;
1252 offset -= len;
1253 }
1254
1255 return VM_FAULT_SIGBUS;
1256}
1257
1258static const struct vm_operations_struct sg_mmap_vm_ops = {
1259 .fault = sg_vma_fault,
1260};
1261
1262static int
1263sg_mmap(struct file *filp, struct vm_area_struct *vma)
1264{
1265 Sg_fd *sfp;
1266 unsigned long req_sz, len, sa;
1267 Sg_scatter_hold *rsv_schp;
1268 int k, length;
1269 int ret = 0;
1270
1271 if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1272 return -ENXIO;
1273 req_sz = vma->vm_end - vma->vm_start;
1274 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1275 "sg_mmap starting, vm_start=%p, len=%d\n",
1276 (void *) vma->vm_start, (int) req_sz));
1277 if (vma->vm_pgoff)
1278 return -EINVAL; /* want no offset */
1279 rsv_schp = &sfp->reserve;
1280 mutex_lock(&sfp->f_mutex);
1281 if (req_sz > rsv_schp->bufflen) {
1282 ret = -ENOMEM; /* cannot map more than reserved buffer */
1283 goto out;
1284 }
1285
1286 sa = vma->vm_start;
1287 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1288 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1289 len = vma->vm_end - sa;
1290 len = (len < length) ? len : length;
1291 sa += len;
1292 }
1293
1294 sfp->mmap_called = 1;
1295 vm_flags_set(vma, VM_IO | VM_DONTEXPAND | VM_DONTDUMP);
1296 vma->vm_private_data = sfp;
1297 vma->vm_ops = &sg_mmap_vm_ops;
1298out:
1299 mutex_unlock(lock: &sfp->f_mutex);
1300 return ret;
1301}
1302
1303static void
1304sg_rq_end_io_usercontext(struct work_struct *work)
1305{
1306 struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1307 struct sg_fd *sfp = srp->parentfp;
1308
1309 sg_finish_rem_req(srp);
1310 sg_remove_request(sfp, srp);
1311 kref_put(kref: &sfp->f_ref, release: sg_remove_sfp);
1312}
1313
1314/*
1315 * This function is a "bottom half" handler that is called by the mid
1316 * level when a command is completed (or has failed).
1317 */
1318static enum rq_end_io_ret
1319sg_rq_end_io(struct request *rq, blk_status_t status)
1320{
1321 struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
1322 struct sg_request *srp = rq->end_io_data;
1323 Sg_device *sdp;
1324 Sg_fd *sfp;
1325 unsigned long iflags;
1326 unsigned int ms;
1327 char *sense;
1328 int result, resid, done = 1;
1329
1330 if (WARN_ON(srp->done != 0))
1331 return RQ_END_IO_NONE;
1332
1333 sfp = srp->parentfp;
1334 if (WARN_ON(sfp == NULL))
1335 return RQ_END_IO_NONE;
1336
1337 sdp = sfp->parentdp;
1338 if (unlikely(atomic_read(&sdp->detaching)))
1339 pr_info("%s: device detaching\n", __func__);
1340
1341 sense = scmd->sense_buffer;
1342 result = scmd->result;
1343 resid = scmd->resid_len;
1344
1345 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1346 "sg_cmd_done: pack_id=%d, res=0x%x\n",
1347 srp->header.pack_id, result));
1348 srp->header.resid = resid;
1349 ms = jiffies_to_msecs(j: jiffies);
1350 srp->header.duration = (ms > srp->header.duration) ?
1351 (ms - srp->header.duration) : 0;
1352 if (0 != result) {
1353 struct scsi_sense_hdr sshdr;
1354
1355 srp->header.status = 0xff & result;
1356 srp->header.masked_status = sg_status_byte(result);
1357 srp->header.msg_status = COMMAND_COMPLETE;
1358 srp->header.host_status = host_byte(result);
1359 srp->header.driver_status = driver_byte(result);
1360 if ((sdp->sgdebug > 0) &&
1361 ((CHECK_CONDITION == srp->header.masked_status) ||
1362 (COMMAND_TERMINATED == srp->header.masked_status)))
1363 __scsi_print_sense(sdp->device, name: __func__, sense_buffer: sense,
1364 SCSI_SENSE_BUFFERSIZE);
1365
1366 /* Following if statement is a patch supplied by Eric Youngdale */
1367 if (driver_byte(result) != 0
1368 && scsi_normalize_sense(sense_buffer: sense, SCSI_SENSE_BUFFERSIZE, sshdr: &sshdr)
1369 && !scsi_sense_is_deferred(sshdr: &sshdr)
1370 && sshdr.sense_key == UNIT_ATTENTION
1371 && sdp->device->removable) {
1372 /* Detected possible disc change. Set the bit - this */
1373 /* may be used if there are filesystems using this device */
1374 sdp->device->changed = 1;
1375 }
1376 }
1377
1378 if (scmd->sense_len)
1379 memcpy(srp->sense_b, scmd->sense_buffer, SCSI_SENSE_BUFFERSIZE);
1380
1381 /* Rely on write phase to clean out srp status values, so no "else" */
1382
1383 /*
1384 * Free the request as soon as it is complete so that its resources
1385 * can be reused without waiting for userspace to read() the
1386 * result. But keep the associated bio (if any) around until
1387 * blk_rq_unmap_user() can be called from user context.
1388 */
1389 srp->rq = NULL;
1390 blk_mq_free_request(rq);
1391
1392 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1393 if (unlikely(srp->orphan)) {
1394 if (sfp->keep_orphan)
1395 srp->sg_io_owned = 0;
1396 else
1397 done = 0;
1398 }
1399 srp->done = done;
1400 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1401
1402 if (likely(done)) {
1403 /* Now wake up any sg_read() that is waiting for this
1404 * packet.
1405 */
1406 wake_up_interruptible(&sfp->read_wait);
1407 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1408 kref_put(kref: &sfp->f_ref, release: sg_remove_sfp);
1409 } else {
1410 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1411 schedule_work(work: &srp->ew.work);
1412 }
1413 return RQ_END_IO_NONE;
1414}
1415
1416static const struct file_operations sg_fops = {
1417 .owner = THIS_MODULE,
1418 .read = sg_read,
1419 .write = sg_write,
1420 .poll = sg_poll,
1421 .unlocked_ioctl = sg_ioctl,
1422 .compat_ioctl = compat_ptr_ioctl,
1423 .open = sg_open,
1424 .mmap = sg_mmap,
1425 .release = sg_release,
1426 .fasync = sg_fasync,
1427 .llseek = no_llseek,
1428};
1429
1430static const struct class sg_sysfs_class = {
1431 .name = "scsi_generic"
1432};
1433
1434static int sg_sysfs_valid = 0;
1435
1436static Sg_device *
1437sg_alloc(struct scsi_device *scsidp)
1438{
1439 struct request_queue *q = scsidp->request_queue;
1440 Sg_device *sdp;
1441 unsigned long iflags;
1442 int error;
1443 u32 k;
1444
1445 sdp = kzalloc(size: sizeof(Sg_device), GFP_KERNEL);
1446 if (!sdp) {
1447 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1448 "failure\n", __func__);
1449 return ERR_PTR(error: -ENOMEM);
1450 }
1451
1452 idr_preload(GFP_KERNEL);
1453 write_lock_irqsave(&sg_index_lock, iflags);
1454
1455 error = idr_alloc(&sg_index_idr, ptr: sdp, start: 0, SG_MAX_DEVS, GFP_NOWAIT);
1456 if (error < 0) {
1457 if (error == -ENOSPC) {
1458 sdev_printk(KERN_WARNING, scsidp,
1459 "Unable to attach sg device type=%d, minor number exceeds %d\n",
1460 scsidp->type, SG_MAX_DEVS - 1);
1461 error = -ENODEV;
1462 } else {
1463 sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1464 "allocation Sg_device failure: %d\n",
1465 __func__, error);
1466 }
1467 goto out_unlock;
1468 }
1469 k = error;
1470
1471 SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1472 "sg_alloc: dev=%d \n", k));
1473 sprintf(buf: sdp->name, fmt: "sg%d", k);
1474 sdp->device = scsidp;
1475 mutex_init(&sdp->open_rel_lock);
1476 INIT_LIST_HEAD(list: &sdp->sfds);
1477 init_waitqueue_head(&sdp->open_wait);
1478 atomic_set(v: &sdp->detaching, i: 0);
1479 rwlock_init(&sdp->sfd_lock);
1480 sdp->sg_tablesize = queue_max_segments(q);
1481 sdp->index = k;
1482 kref_init(kref: &sdp->d_ref);
1483 error = 0;
1484
1485out_unlock:
1486 write_unlock_irqrestore(&sg_index_lock, iflags);
1487 idr_preload_end();
1488
1489 if (error) {
1490 kfree(objp: sdp);
1491 return ERR_PTR(error);
1492 }
1493 return sdp;
1494}
1495
1496static int
1497sg_add_device(struct device *cl_dev)
1498{
1499 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1500 Sg_device *sdp = NULL;
1501 struct cdev * cdev = NULL;
1502 int error;
1503 unsigned long iflags;
1504
1505 if (!blk_get_queue(scsidp->request_queue)) {
1506 pr_warn("%s: get scsi_device queue failed\n", __func__);
1507 return -ENODEV;
1508 }
1509
1510 error = -ENOMEM;
1511 cdev = cdev_alloc();
1512 if (!cdev) {
1513 pr_warn("%s: cdev_alloc failed\n", __func__);
1514 goto out;
1515 }
1516 cdev->owner = THIS_MODULE;
1517 cdev->ops = &sg_fops;
1518
1519 sdp = sg_alloc(scsidp);
1520 if (IS_ERR(ptr: sdp)) {
1521 pr_warn("%s: sg_alloc failed\n", __func__);
1522 error = PTR_ERR(ptr: sdp);
1523 goto out;
1524 }
1525
1526 error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1527 if (error)
1528 goto cdev_add_err;
1529
1530 sdp->cdev = cdev;
1531 if (sg_sysfs_valid) {
1532 struct device *sg_class_member;
1533
1534 sg_class_member = device_create(cls: &sg_sysfs_class, parent: cl_dev->parent,
1535 MKDEV(SCSI_GENERIC_MAJOR,
1536 sdp->index),
1537 drvdata: sdp, fmt: "%s", sdp->name);
1538 if (IS_ERR(ptr: sg_class_member)) {
1539 pr_err("%s: device_create failed\n", __func__);
1540 error = PTR_ERR(ptr: sg_class_member);
1541 goto cdev_add_err;
1542 }
1543 error = sysfs_create_link(kobj: &scsidp->sdev_gendev.kobj,
1544 target: &sg_class_member->kobj, name: "generic");
1545 if (error)
1546 pr_err("%s: unable to make symlink 'generic' back "
1547 "to sg%d\n", __func__, sdp->index);
1548 } else
1549 pr_warn("%s: sg_sys Invalid\n", __func__);
1550
1551 sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1552 "type %d\n", sdp->index, scsidp->type);
1553
1554 dev_set_drvdata(dev: cl_dev, data: sdp);
1555
1556 return 0;
1557
1558cdev_add_err:
1559 write_lock_irqsave(&sg_index_lock, iflags);
1560 idr_remove(&sg_index_idr, id: sdp->index);
1561 write_unlock_irqrestore(&sg_index_lock, iflags);
1562 kfree(objp: sdp);
1563
1564out:
1565 if (cdev)
1566 cdev_del(cdev);
1567 blk_put_queue(scsidp->request_queue);
1568 return error;
1569}
1570
1571static void
1572sg_device_destroy(struct kref *kref)
1573{
1574 struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1575 struct request_queue *q = sdp->device->request_queue;
1576 unsigned long flags;
1577
1578 /* CAUTION! Note that the device can still be found via idr_find()
1579 * even though the refcount is 0. Therefore, do idr_remove() BEFORE
1580 * any other cleanup.
1581 */
1582
1583 blk_trace_remove(q);
1584 blk_put_queue(q);
1585
1586 write_lock_irqsave(&sg_index_lock, flags);
1587 idr_remove(&sg_index_idr, id: sdp->index);
1588 write_unlock_irqrestore(&sg_index_lock, flags);
1589
1590 SCSI_LOG_TIMEOUT(3,
1591 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1592
1593 kfree(objp: sdp);
1594}
1595
1596static void
1597sg_remove_device(struct device *cl_dev)
1598{
1599 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1600 Sg_device *sdp = dev_get_drvdata(dev: cl_dev);
1601 unsigned long iflags;
1602 Sg_fd *sfp;
1603 int val;
1604
1605 if (!sdp)
1606 return;
1607 /* want sdp->detaching non-zero as soon as possible */
1608 val = atomic_inc_return(v: &sdp->detaching);
1609 if (val > 1)
1610 return; /* only want to do following once per device */
1611
1612 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1613 "%s\n", __func__));
1614
1615 read_lock_irqsave(&sdp->sfd_lock, iflags);
1616 list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1617 wake_up_interruptible_all(&sfp->read_wait);
1618 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1619 }
1620 wake_up_interruptible_all(&sdp->open_wait);
1621 read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1622
1623 sysfs_remove_link(kobj: &scsidp->sdev_gendev.kobj, name: "generic");
1624 device_destroy(cls: &sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1625 cdev_del(sdp->cdev);
1626 sdp->cdev = NULL;
1627
1628 kref_put(kref: &sdp->d_ref, release: sg_device_destroy);
1629}
1630
1631module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1632module_param_named(def_reserved_size, def_reserved_size, int,
1633 S_IRUGO | S_IWUSR);
1634module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1635
1636MODULE_AUTHOR("Douglas Gilbert");
1637MODULE_DESCRIPTION("SCSI generic (sg) driver");
1638MODULE_LICENSE("GPL");
1639MODULE_VERSION(SG_VERSION_STR);
1640MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1641
1642MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1643 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1644MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1645MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1646
1647#ifdef CONFIG_SYSCTL
1648#include <linux/sysctl.h>
1649
1650static struct ctl_table sg_sysctls[] = {
1651 {
1652 .procname = "sg-big-buff",
1653 .data = &sg_big_buff,
1654 .maxlen = sizeof(int),
1655 .mode = 0444,
1656 .proc_handler = proc_dointvec,
1657 },
1658};
1659
1660static struct ctl_table_header *hdr;
1661static void register_sg_sysctls(void)
1662{
1663 if (!hdr)
1664 hdr = register_sysctl("kernel", sg_sysctls);
1665}
1666
1667static void unregister_sg_sysctls(void)
1668{
1669 if (hdr)
1670 unregister_sysctl_table(table: hdr);
1671}
1672#else
1673#define register_sg_sysctls() do { } while (0)
1674#define unregister_sg_sysctls() do { } while (0)
1675#endif /* CONFIG_SYSCTL */
1676
1677static int __init
1678init_sg(void)
1679{
1680 int rc;
1681
1682 if (scatter_elem_sz < PAGE_SIZE) {
1683 scatter_elem_sz = PAGE_SIZE;
1684 scatter_elem_sz_prev = scatter_elem_sz;
1685 }
1686 if (def_reserved_size >= 0)
1687 sg_big_buff = def_reserved_size;
1688 else
1689 def_reserved_size = sg_big_buff;
1690
1691 rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1692 SG_MAX_DEVS, "sg");
1693 if (rc)
1694 return rc;
1695 rc = class_register(class: &sg_sysfs_class);
1696 if (rc)
1697 goto err_out;
1698 sg_sysfs_valid = 1;
1699 rc = scsi_register_interface(&sg_interface);
1700 if (0 == rc) {
1701#ifdef CONFIG_SCSI_PROC_FS
1702 sg_proc_init();
1703#endif /* CONFIG_SCSI_PROC_FS */
1704 return 0;
1705 }
1706 class_unregister(class: &sg_sysfs_class);
1707 register_sg_sysctls();
1708err_out:
1709 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1710 return rc;
1711}
1712
1713static void __exit
1714exit_sg(void)
1715{
1716 unregister_sg_sysctls();
1717#ifdef CONFIG_SCSI_PROC_FS
1718 remove_proc_subtree("scsi/sg", NULL);
1719#endif /* CONFIG_SCSI_PROC_FS */
1720 scsi_unregister_interface(&sg_interface);
1721 class_unregister(class: &sg_sysfs_class);
1722 sg_sysfs_valid = 0;
1723 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1724 SG_MAX_DEVS);
1725 idr_destroy(&sg_index_idr);
1726}
1727
1728static int
1729sg_start_req(Sg_request *srp, unsigned char *cmd)
1730{
1731 int res;
1732 struct request *rq;
1733 Sg_fd *sfp = srp->parentfp;
1734 sg_io_hdr_t *hp = &srp->header;
1735 int dxfer_len = (int) hp->dxfer_len;
1736 int dxfer_dir = hp->dxfer_direction;
1737 unsigned int iov_count = hp->iovec_count;
1738 Sg_scatter_hold *req_schp = &srp->data;
1739 Sg_scatter_hold *rsv_schp = &sfp->reserve;
1740 struct request_queue *q = sfp->parentdp->device->request_queue;
1741 struct rq_map_data *md, map_data;
1742 int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? ITER_SOURCE : ITER_DEST;
1743 struct scsi_cmnd *scmd;
1744
1745 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1746 "sg_start_req: dxfer_len=%d\n",
1747 dxfer_len));
1748
1749 /*
1750 * NOTE
1751 *
1752 * With scsi-mq enabled, there are a fixed number of preallocated
1753 * requests equal in number to shost->can_queue. If all of the
1754 * preallocated requests are already in use, then scsi_alloc_request()
1755 * will sleep until an active command completes, freeing up a request.
1756 * Although waiting in an asynchronous interface is less than ideal, we
1757 * do not want to use BLK_MQ_REQ_NOWAIT here because userspace might
1758 * not expect an EWOULDBLOCK from this condition.
1759 */
1760 rq = scsi_alloc_request(q, opf: hp->dxfer_direction == SG_DXFER_TO_DEV ?
1761 REQ_OP_DRV_OUT : REQ_OP_DRV_IN, flags: 0);
1762 if (IS_ERR(ptr: rq))
1763 return PTR_ERR(ptr: rq);
1764 scmd = blk_mq_rq_to_pdu(rq);
1765
1766 if (hp->cmd_len > sizeof(scmd->cmnd)) {
1767 blk_mq_free_request(rq);
1768 return -EINVAL;
1769 }
1770
1771 memcpy(scmd->cmnd, cmd, hp->cmd_len);
1772 scmd->cmd_len = hp->cmd_len;
1773
1774 srp->rq = rq;
1775 rq->end_io_data = srp;
1776 scmd->allowed = SG_DEFAULT_RETRIES;
1777
1778 if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1779 return 0;
1780
1781 if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1782 dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1783 blk_rq_aligned(q, addr: (unsigned long)hp->dxferp, len: dxfer_len))
1784 md = NULL;
1785 else
1786 md = &map_data;
1787
1788 if (md) {
1789 mutex_lock(&sfp->f_mutex);
1790 if (dxfer_len <= rsv_schp->bufflen &&
1791 !sfp->res_in_use) {
1792 sfp->res_in_use = 1;
1793 sg_link_reserve(sfp, srp, size: dxfer_len);
1794 } else if (hp->flags & SG_FLAG_MMAP_IO) {
1795 res = -EBUSY; /* sfp->res_in_use == 1 */
1796 if (dxfer_len > rsv_schp->bufflen)
1797 res = -ENOMEM;
1798 mutex_unlock(lock: &sfp->f_mutex);
1799 return res;
1800 } else {
1801 res = sg_build_indirect(schp: req_schp, sfp, buff_size: dxfer_len);
1802 if (res) {
1803 mutex_unlock(lock: &sfp->f_mutex);
1804 return res;
1805 }
1806 }
1807 mutex_unlock(lock: &sfp->f_mutex);
1808
1809 md->pages = req_schp->pages;
1810 md->page_order = req_schp->page_order;
1811 md->nr_entries = req_schp->k_use_sg;
1812 md->offset = 0;
1813 md->null_mapped = hp->dxferp ? 0 : 1;
1814 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1815 md->from_user = 1;
1816 else
1817 md->from_user = 0;
1818 }
1819
1820 res = blk_rq_map_user_io(rq, md, hp->dxferp, hp->dxfer_len,
1821 GFP_ATOMIC, iov_count, iov_count, 1, rw);
1822 if (!res) {
1823 srp->bio = rq->bio;
1824
1825 if (!md) {
1826 req_schp->dio_in_use = 1;
1827 hp->info |= SG_INFO_DIRECT_IO;
1828 }
1829 }
1830 return res;
1831}
1832
1833static int
1834sg_finish_rem_req(Sg_request *srp)
1835{
1836 int ret = 0;
1837
1838 Sg_fd *sfp = srp->parentfp;
1839 Sg_scatter_hold *req_schp = &srp->data;
1840
1841 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1842 "sg_finish_rem_req: res_used=%d\n",
1843 (int) srp->res_used));
1844 if (srp->bio)
1845 ret = blk_rq_unmap_user(srp->bio);
1846
1847 if (srp->rq)
1848 blk_mq_free_request(rq: srp->rq);
1849
1850 if (srp->res_used)
1851 sg_unlink_reserve(sfp, srp);
1852 else
1853 sg_remove_scat(sfp, schp: req_schp);
1854
1855 return ret;
1856}
1857
1858static int
1859sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1860{
1861 int sg_bufflen = tablesize * sizeof(struct page *);
1862 gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1863
1864 schp->pages = kzalloc(size: sg_bufflen, flags: gfp_flags);
1865 if (!schp->pages)
1866 return -ENOMEM;
1867 schp->sglist_len = sg_bufflen;
1868 return tablesize; /* number of scat_gath elements allocated */
1869}
1870
1871static int
1872sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1873{
1874 int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1875 int sg_tablesize = sfp->parentdp->sg_tablesize;
1876 int blk_size = buff_size, order;
1877 gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
1878
1879 if (blk_size < 0)
1880 return -EFAULT;
1881 if (0 == blk_size)
1882 ++blk_size; /* don't know why */
1883 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1884 blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1885 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1886 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1887 buff_size, blk_size));
1888
1889 /* N.B. ret_sz carried into this block ... */
1890 mx_sc_elems = sg_build_sgat(schp, sfp, tablesize: sg_tablesize);
1891 if (mx_sc_elems < 0)
1892 return mx_sc_elems; /* most likely -ENOMEM */
1893
1894 num = scatter_elem_sz;
1895 if (unlikely(num != scatter_elem_sz_prev)) {
1896 if (num < PAGE_SIZE) {
1897 scatter_elem_sz = PAGE_SIZE;
1898 scatter_elem_sz_prev = PAGE_SIZE;
1899 } else
1900 scatter_elem_sz_prev = num;
1901 }
1902
1903 order = get_order(size: num);
1904retry:
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: 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;
1939out:
1940 for (i = 0; i < k; i++)
1941 __free_pages(page: schp->pages[i], order);
1942
1943 if (--order >= 0)
1944 goto retry;
1945
1946 return -ENOMEM;
1947}
1948
1949static void
1950sg_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(page: schp->pages[k], order: schp->page_order);
1964 }
1965
1966 kfree(objp: schp->pages);
1967 }
1968 }
1969 memset(schp, 0, sizeof (*schp));
1970}
1971
1972static int
1973sg_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(to: outp, page_address(schp->pages[k]),
1988 n: num_read_xfer))
1989 return -EFAULT;
1990 break;
1991 } else {
1992 if (copy_to_user(to: outp, page_address(schp->pages[k]),
1993 n: 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
2005static void
2006sg_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, buff_size: 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
2023static void
2024sg_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
2054static void
2055sg_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
2072static Sg_request *
2073sg_get_rq_mark(Sg_fd * sfp, int pack_id, bool *busy)
2074{
2075 Sg_request *resp;
2076 unsigned long iflags;
2077
2078 *busy = false;
2079 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2080 list_for_each_entry(resp, &sfp->rq_list, entry) {
2081 /* look for requests that are not SG_IO owned */
2082 if ((!resp->sg_io_owned) &&
2083 ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2084 switch (resp->done) {
2085 case 0: /* request active */
2086 *busy = true;
2087 break;
2088 case 1: /* request done; response ready to return */
2089 resp->done = 2; /* guard against other readers */
2090 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2091 return resp;
2092 case 2: /* response already being returned */
2093 break;
2094 }
2095 }
2096 }
2097 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2098 return NULL;
2099}
2100
2101/* always adds to end of list */
2102static Sg_request *
2103sg_add_request(Sg_fd * sfp)
2104{
2105 int k;
2106 unsigned long iflags;
2107 Sg_request *rp = sfp->req_arr;
2108
2109 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2110 if (!list_empty(head: &sfp->rq_list)) {
2111 if (!sfp->cmd_q)
2112 goto out_unlock;
2113
2114 for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2115 if (!rp->parentfp)
2116 break;
2117 }
2118 if (k >= SG_MAX_QUEUE)
2119 goto out_unlock;
2120 }
2121 memset(rp, 0, sizeof (Sg_request));
2122 rp->parentfp = sfp;
2123 rp->header.duration = jiffies_to_msecs(j: jiffies);
2124 list_add_tail(new: &rp->entry, head: &sfp->rq_list);
2125 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2126 return rp;
2127out_unlock:
2128 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2129 return NULL;
2130}
2131
2132/* Return of 1 for found; 0 for not found */
2133static int
2134sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2135{
2136 unsigned long iflags;
2137 int res = 0;
2138
2139 if (!sfp || !srp || list_empty(head: &sfp->rq_list))
2140 return res;
2141 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2142 if (!list_empty(head: &srp->entry)) {
2143 list_del(entry: &srp->entry);
2144 srp->parentfp = NULL;
2145 res = 1;
2146 }
2147 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2148
2149 /*
2150 * If the device is detaching, wakeup any readers in case we just
2151 * removed the last response, which would leave nothing for them to
2152 * return other than -ENODEV.
2153 */
2154 if (unlikely(atomic_read(&sfp->parentdp->detaching)))
2155 wake_up_interruptible_all(&sfp->read_wait);
2156
2157 return res;
2158}
2159
2160static Sg_fd *
2161sg_add_sfp(Sg_device * sdp)
2162{
2163 Sg_fd *sfp;
2164 unsigned long iflags;
2165 int bufflen;
2166
2167 sfp = kzalloc(size: sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2168 if (!sfp)
2169 return ERR_PTR(error: -ENOMEM);
2170
2171 init_waitqueue_head(&sfp->read_wait);
2172 rwlock_init(&sfp->rq_list_lock);
2173 INIT_LIST_HEAD(list: &sfp->rq_list);
2174 kref_init(kref: &sfp->f_ref);
2175 mutex_init(&sfp->f_mutex);
2176 sfp->timeout = SG_DEFAULT_TIMEOUT;
2177 sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2178 sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2179 sfp->cmd_q = SG_DEF_COMMAND_Q;
2180 sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2181 sfp->parentdp = sdp;
2182 write_lock_irqsave(&sdp->sfd_lock, iflags);
2183 if (atomic_read(v: &sdp->detaching)) {
2184 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2185 kfree(objp: sfp);
2186 return ERR_PTR(error: -ENODEV);
2187 }
2188 list_add_tail(new: &sfp->sfd_siblings, head: &sdp->sfds);
2189 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2190 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2191 "sg_add_sfp: sfp=0x%p\n", sfp));
2192 if (unlikely(sg_big_buff != def_reserved_size))
2193 sg_big_buff = def_reserved_size;
2194
2195 bufflen = min_t(int, sg_big_buff,
2196 max_sectors_bytes(sdp->device->request_queue));
2197 sg_build_reserve(sfp, req_size: bufflen);
2198 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2199 "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2200 sfp->reserve.bufflen,
2201 sfp->reserve.k_use_sg));
2202
2203 kref_get(kref: &sdp->d_ref);
2204 __module_get(THIS_MODULE);
2205 return sfp;
2206}
2207
2208static void
2209sg_remove_sfp_usercontext(struct work_struct *work)
2210{
2211 struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2212 struct sg_device *sdp = sfp->parentdp;
2213 struct scsi_device *device = sdp->device;
2214 Sg_request *srp;
2215 unsigned long iflags;
2216
2217 /* Cleanup any responses which were never read(). */
2218 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2219 while (!list_empty(head: &sfp->rq_list)) {
2220 srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2221 sg_finish_rem_req(srp);
2222 list_del(entry: &srp->entry);
2223 srp->parentfp = NULL;
2224 }
2225 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2226
2227 if (sfp->reserve.bufflen > 0) {
2228 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2229 "sg_remove_sfp: bufflen=%d, k_use_sg=%d\n",
2230 (int) sfp->reserve.bufflen,
2231 (int) sfp->reserve.k_use_sg));
2232 sg_remove_scat(sfp, schp: &sfp->reserve);
2233 }
2234
2235 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2236 "sg_remove_sfp: sfp=0x%p\n", sfp));
2237 kfree(objp: sfp);
2238
2239 kref_put(kref: &sdp->d_ref, release: sg_device_destroy);
2240 scsi_device_put(device);
2241 module_put(THIS_MODULE);
2242}
2243
2244static void
2245sg_remove_sfp(struct kref *kref)
2246{
2247 struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2248 struct sg_device *sdp = sfp->parentdp;
2249 unsigned long iflags;
2250
2251 write_lock_irqsave(&sdp->sfd_lock, iflags);
2252 list_del(entry: &sfp->sfd_siblings);
2253 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2254
2255 INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2256 schedule_work(work: &sfp->ew.work);
2257}
2258
2259#ifdef CONFIG_SCSI_PROC_FS
2260static int
2261sg_idr_max_id(int id, void *p, void *data)
2262{
2263 int *k = data;
2264
2265 if (*k < id)
2266 *k = id;
2267
2268 return 0;
2269}
2270
2271static int
2272sg_last_dev(void)
2273{
2274 int k = -1;
2275 unsigned long iflags;
2276
2277 read_lock_irqsave(&sg_index_lock, iflags);
2278 idr_for_each(&sg_index_idr, fn: sg_idr_max_id, data: &k);
2279 read_unlock_irqrestore(&sg_index_lock, iflags);
2280 return k + 1; /* origin 1 */
2281}
2282#endif
2283
2284/* must be called with sg_index_lock held */
2285static Sg_device *sg_lookup_dev(int dev)
2286{
2287 return idr_find(&sg_index_idr, id: dev);
2288}
2289
2290static Sg_device *
2291sg_get_dev(int dev)
2292{
2293 struct sg_device *sdp;
2294 unsigned long flags;
2295
2296 read_lock_irqsave(&sg_index_lock, flags);
2297 sdp = sg_lookup_dev(dev);
2298 if (!sdp)
2299 sdp = ERR_PTR(error: -ENXIO);
2300 else if (atomic_read(v: &sdp->detaching)) {
2301 /* If sdp->detaching, then the refcount may already be 0, in
2302 * which case it would be a bug to do kref_get().
2303 */
2304 sdp = ERR_PTR(error: -ENODEV);
2305 } else
2306 kref_get(kref: &sdp->d_ref);
2307 read_unlock_irqrestore(&sg_index_lock, flags);
2308
2309 return sdp;
2310}
2311
2312#ifdef CONFIG_SCSI_PROC_FS
2313static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2314
2315static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2316static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2317 size_t count, loff_t *off);
2318static const struct proc_ops adio_proc_ops = {
2319 .proc_open = sg_proc_single_open_adio,
2320 .proc_read = seq_read,
2321 .proc_lseek = seq_lseek,
2322 .proc_write = sg_proc_write_adio,
2323 .proc_release = single_release,
2324};
2325
2326static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2327static ssize_t sg_proc_write_dressz(struct file *filp,
2328 const char __user *buffer, size_t count, loff_t *off);
2329static const struct proc_ops dressz_proc_ops = {
2330 .proc_open = sg_proc_single_open_dressz,
2331 .proc_read = seq_read,
2332 .proc_lseek = seq_lseek,
2333 .proc_write = sg_proc_write_dressz,
2334 .proc_release = single_release,
2335};
2336
2337static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2338static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2339static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2340static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2341static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2342static void dev_seq_stop(struct seq_file *s, void *v);
2343static const struct seq_operations dev_seq_ops = {
2344 .start = dev_seq_start,
2345 .next = dev_seq_next,
2346 .stop = dev_seq_stop,
2347 .show = sg_proc_seq_show_dev,
2348};
2349
2350static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2351static const struct seq_operations devstrs_seq_ops = {
2352 .start = dev_seq_start,
2353 .next = dev_seq_next,
2354 .stop = dev_seq_stop,
2355 .show = sg_proc_seq_show_devstrs,
2356};
2357
2358static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2359static const struct seq_operations debug_seq_ops = {
2360 .start = dev_seq_start,
2361 .next = dev_seq_next,
2362 .stop = dev_seq_stop,
2363 .show = sg_proc_seq_show_debug,
2364};
2365
2366static int
2367sg_proc_init(void)
2368{
2369 struct proc_dir_entry *p;
2370
2371 p = proc_mkdir("scsi/sg", NULL);
2372 if (!p)
2373 return 1;
2374
2375 proc_create(name: "allow_dio", S_IRUGO | S_IWUSR, parent: p, proc_ops: &adio_proc_ops);
2376 proc_create_seq("debug", S_IRUGO, p, &debug_seq_ops);
2377 proc_create(name: "def_reserved_size", S_IRUGO | S_IWUSR, parent: p, proc_ops: &dressz_proc_ops);
2378 proc_create_single("device_hdr", S_IRUGO, p, sg_proc_seq_show_devhdr);
2379 proc_create_seq("devices", S_IRUGO, p, &dev_seq_ops);
2380 proc_create_seq("device_strs", S_IRUGO, p, &devstrs_seq_ops);
2381 proc_create_single("version", S_IRUGO, p, sg_proc_seq_show_version);
2382 return 0;
2383}
2384
2385
2386static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2387{
2388 seq_printf(m: s, fmt: "%d\n", *((int *)s->private));
2389 return 0;
2390}
2391
2392static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2393{
2394 return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2395}
2396
2397static ssize_t
2398sg_proc_write_adio(struct file *filp, const char __user *buffer,
2399 size_t count, loff_t *off)
2400{
2401 int err;
2402 unsigned long num;
2403
2404 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2405 return -EACCES;
2406 err = kstrtoul_from_user(s: buffer, count, base: 0, res: &num);
2407 if (err)
2408 return err;
2409 sg_allow_dio = num ? 1 : 0;
2410 return count;
2411}
2412
2413static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2414{
2415 return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2416}
2417
2418static ssize_t
2419sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2420 size_t count, loff_t *off)
2421{
2422 int err;
2423 unsigned long k = ULONG_MAX;
2424
2425 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2426 return -EACCES;
2427
2428 err = kstrtoul_from_user(s: buffer, count, base: 0, res: &k);
2429 if (err)
2430 return err;
2431 if (k <= 1048576) { /* limit "big buff" to 1 MB */
2432 sg_big_buff = k;
2433 return count;
2434 }
2435 return -ERANGE;
2436}
2437
2438static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2439{
2440 seq_printf(m: s, fmt: "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2441 sg_version_date);
2442 return 0;
2443}
2444
2445static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2446{
2447 seq_puts(m: s, s: "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2448 return 0;
2449}
2450
2451struct sg_proc_deviter {
2452 loff_t index;
2453 size_t max;
2454};
2455
2456static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2457{
2458 struct sg_proc_deviter * it = kmalloc(size: sizeof(*it), GFP_KERNEL);
2459
2460 s->private = it;
2461 if (! it)
2462 return NULL;
2463
2464 it->index = *pos;
2465 it->max = sg_last_dev();
2466 if (it->index >= it->max)
2467 return NULL;
2468 return it;
2469}
2470
2471static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2472{
2473 struct sg_proc_deviter * it = s->private;
2474
2475 *pos = ++it->index;
2476 return (it->index < it->max) ? it : NULL;
2477}
2478
2479static void dev_seq_stop(struct seq_file *s, void *v)
2480{
2481 kfree(objp: s->private);
2482}
2483
2484static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2485{
2486 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2487 Sg_device *sdp;
2488 struct scsi_device *scsidp;
2489 unsigned long iflags;
2490
2491 read_lock_irqsave(&sg_index_lock, iflags);
2492 sdp = it ? sg_lookup_dev(dev: it->index) : NULL;
2493 if ((NULL == sdp) || (NULL == sdp->device) ||
2494 (atomic_read(v: &sdp->detaching)))
2495 seq_puts(m: s, s: "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2496 else {
2497 scsidp = sdp->device;
2498 seq_printf(m: s, fmt: "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2499 scsidp->host->host_no, scsidp->channel,
2500 scsidp->id, scsidp->lun, (int) scsidp->type,
2501 1,
2502 (int) scsidp->queue_depth,
2503 (int) scsi_device_busy(sdev: scsidp),
2504 (int) scsi_device_online(sdev: scsidp));
2505 }
2506 read_unlock_irqrestore(&sg_index_lock, iflags);
2507 return 0;
2508}
2509
2510static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2511{
2512 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2513 Sg_device *sdp;
2514 struct scsi_device *scsidp;
2515 unsigned long iflags;
2516
2517 read_lock_irqsave(&sg_index_lock, iflags);
2518 sdp = it ? sg_lookup_dev(dev: it->index) : NULL;
2519 scsidp = sdp ? sdp->device : NULL;
2520 if (sdp && scsidp && (!atomic_read(v: &sdp->detaching)))
2521 seq_printf(m: s, fmt: "%8.8s\t%16.16s\t%4.4s\n",
2522 scsidp->vendor, scsidp->model, scsidp->rev);
2523 else
2524 seq_puts(m: s, s: "<no active device>\n");
2525 read_unlock_irqrestore(&sg_index_lock, iflags);
2526 return 0;
2527}
2528
2529/* must be called while holding sg_index_lock */
2530static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2531{
2532 int k, new_interface, blen, usg;
2533 Sg_request *srp;
2534 Sg_fd *fp;
2535 const sg_io_hdr_t *hp;
2536 const char * cp;
2537 unsigned int ms;
2538
2539 k = 0;
2540 list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2541 k++;
2542 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2543 seq_printf(m: s, fmt: " FD(%d): timeout=%dms bufflen=%d "
2544 "(res)sgat=%d low_dma=%d\n", k,
2545 jiffies_to_msecs(j: fp->timeout),
2546 fp->reserve.bufflen,
2547 (int) fp->reserve.k_use_sg, 0);
2548 seq_printf(m: s, fmt: " cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2549 (int) fp->cmd_q, (int) fp->force_packid,
2550 (int) fp->keep_orphan);
2551 list_for_each_entry(srp, &fp->rq_list, entry) {
2552 hp = &srp->header;
2553 new_interface = (hp->interface_id == '\0') ? 0 : 1;
2554 if (srp->res_used) {
2555 if (new_interface &&
2556 (SG_FLAG_MMAP_IO & hp->flags))
2557 cp = " mmap>> ";
2558 else
2559 cp = " rb>> ";
2560 } else {
2561 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2562 cp = " dio>> ";
2563 else
2564 cp = " ";
2565 }
2566 seq_puts(m: s, s: cp);
2567 blen = srp->data.bufflen;
2568 usg = srp->data.k_use_sg;
2569 seq_puts(m: s, s: srp->done ?
2570 ((1 == srp->done) ? "rcv:" : "fin:")
2571 : "act:");
2572 seq_printf(m: s, fmt: " id=%d blen=%d",
2573 srp->header.pack_id, blen);
2574 if (srp->done)
2575 seq_printf(m: s, fmt: " dur=%d", hp->duration);
2576 else {
2577 ms = jiffies_to_msecs(j: jiffies);
2578 seq_printf(m: s, fmt: " t_o/elap=%d/%d",
2579 (new_interface ? hp->timeout :
2580 jiffies_to_msecs(j: fp->timeout)),
2581 (ms > hp->duration ? ms - hp->duration : 0));
2582 }
2583 seq_printf(m: s, fmt: "ms sgat=%d op=0x%02x\n", usg,
2584 (int) srp->data.cmd_opcode);
2585 }
2586 if (list_empty(head: &fp->rq_list))
2587 seq_puts(m: s, s: " No requests active\n");
2588 read_unlock(&fp->rq_list_lock);
2589 }
2590}
2591
2592static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2593{
2594 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2595 Sg_device *sdp;
2596 unsigned long iflags;
2597
2598 if (it && (0 == it->index))
2599 seq_printf(m: s, fmt: "max_active_device=%d def_reserved_size=%d\n",
2600 (int)it->max, sg_big_buff);
2601
2602 read_lock_irqsave(&sg_index_lock, iflags);
2603 sdp = it ? sg_lookup_dev(dev: it->index) : NULL;
2604 if (NULL == sdp)
2605 goto skip;
2606 read_lock(&sdp->sfd_lock);
2607 if (!list_empty(head: &sdp->sfds)) {
2608 seq_printf(m: s, fmt: " >>> device=%s ", sdp->name);
2609 if (atomic_read(v: &sdp->detaching))
2610 seq_puts(m: s, s: "detaching pending close ");
2611 else if (sdp->device) {
2612 struct scsi_device *scsidp = sdp->device;
2613
2614 seq_printf(m: s, fmt: "%d:%d:%d:%llu em=%d",
2615 scsidp->host->host_no,
2616 scsidp->channel, scsidp->id,
2617 scsidp->lun,
2618 scsidp->host->hostt->emulated);
2619 }
2620 seq_printf(m: s, fmt: " sg_tablesize=%d excl=%d open_cnt=%d\n",
2621 sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2622 sg_proc_debug_helper(s, sdp);
2623 }
2624 read_unlock(&sdp->sfd_lock);
2625skip:
2626 read_unlock_irqrestore(&sg_index_lock, iflags);
2627 return 0;
2628}
2629
2630#endif /* CONFIG_SCSI_PROC_FS */
2631
2632module_init(init_sg);
2633module_exit(exit_sg);
2634

source code of linux/drivers/scsi/sg.c