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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, 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(&sdp->open_rel_lock);
253 retval = wait_event_interruptible(sdp->open_wait,
254 (atomic_read(&sdp->detaching) ||
255 !sdp->open_cnt));
256 mutex_lock(&sdp->open_rel_lock);
257
258 if (retval) /* -ERESTARTSYS */
259 return retval;
260 if (atomic_read(&sdp->detaching))
261 return -ENODEV;
262 }
263 } else {
264 while (sdp->exclude) {
265 mutex_unlock(&sdp->open_rel_lock);
266 retval = wait_event_interruptible(sdp->open_wait,
267 (atomic_read(&sdp->detaching) ||
268 !sdp->exclude));
269 mutex_lock(&sdp->open_rel_lock);
270
271 if (retval) /* -ERESTARTSYS */
272 return retval;
273 if (atomic_read(&sdp->detaching))
274 return -ENODEV;
275 }
276 }
277
278 return retval;
279}
280
281/* Returns 0 on success, else a negated errno value */
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 Sg_device *sdp;
289 Sg_fd *sfp;
290 int retval;
291
292 nonseekable_open(inode, filp);
293 if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
294 return -EPERM; /* Can't lock it with read only access */
295 sdp = sg_get_dev(dev);
296 if (IS_ERR(sdp))
297 return PTR_ERR(sdp);
298
299 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
300 "sg_open: flags=0x%x\n", flags));
301
302 /* This driver's module count bumped by fops_get in <linux/fs.h> */
303 /* Prevent the device driver from vanishing while we sleep */
304 retval = scsi_device_get(sdp->device);
305 if (retval)
306 goto sg_put;
307
308 retval = scsi_autopm_get_device(sdp->device);
309 if (retval)
310 goto sdp_put;
311
312 /* scsi_block_when_processing_errors() may block so bypass
313 * check if O_NONBLOCK. Permits SCSI commands to be issued
314 * during error recovery. Tread carefully. */
315 if (!((flags & O_NONBLOCK) ||
316 scsi_block_when_processing_errors(sdp->device))) {
317 retval = -ENXIO;
318 /* we are in error recovery for this device */
319 goto error_out;
320 }
321
322 mutex_lock(&sdp->open_rel_lock);
323 if (flags & O_NONBLOCK) {
324 if (flags & O_EXCL) {
325 if (sdp->open_cnt > 0) {
326 retval = -EBUSY;
327 goto error_mutex_locked;
328 }
329 } else {
330 if (sdp->exclude) {
331 retval = -EBUSY;
332 goto error_mutex_locked;
333 }
334 }
335 } else {
336 retval = open_wait(sdp, flags);
337 if (retval) /* -ERESTARTSYS or -ENODEV */
338 goto error_mutex_locked;
339 }
340
341 /* N.B. at this point we are holding the open_rel_lock */
342 if (flags & O_EXCL)
343 sdp->exclude = true;
344
345 if (sdp->open_cnt < 1) { /* no existing opens */
346 sdp->sgdebug = 0;
347 q = sdp->device->request_queue;
348 sdp->sg_tablesize = queue_max_segments(q);
349 }
350 sfp = sg_add_sfp(sdp);
351 if (IS_ERR(sfp)) {
352 retval = PTR_ERR(sfp);
353 goto out_undo;
354 }
355
356 filp->private_data = sfp;
357 sdp->open_cnt++;
358 mutex_unlock(&sdp->open_rel_lock);
359
360 retval = 0;
361sg_put:
362 kref_put(&sdp->d_ref, sg_device_destroy);
363 return retval;
364
365out_undo:
366 if (flags & O_EXCL) {
367 sdp->exclude = false; /* undo if error */
368 wake_up_interruptible(&sdp->open_wait);
369 }
370error_mutex_locked:
371 mutex_unlock(&sdp->open_rel_lock);
372error_out:
373 scsi_autopm_put_device(sdp->device);
374sdp_put:
375 scsi_device_put(sdp->device);
376 goto sg_put;
377}
378
379/* Release resources associated with a successful sg_open()
380 * Returns 0 on success, else a negated errno value */
381static int
382sg_release(struct inode *inode, struct file *filp)
383{
384 Sg_device *sdp;
385 Sg_fd *sfp;
386
387 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
388 return -ENXIO;
389 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
390
391 mutex_lock(&sdp->open_rel_lock);
392 scsi_autopm_put_device(sdp->device);
393 kref_put(&sfp->f_ref, sg_remove_sfp);
394 sdp->open_cnt--;
395
396 /* possibly many open()s waiting on exlude clearing, start many;
397 * only open(O_EXCL)s wait on 0==open_cnt so only start one */
398 if (sdp->exclude) {
399 sdp->exclude = false;
400 wake_up_interruptible_all(&sdp->open_wait);
401 } else if (0 == sdp->open_cnt) {
402 wake_up_interruptible(&sdp->open_wait);
403 }
404 mutex_unlock(&sdp->open_rel_lock);
405 return 0;
406}
407
408static int get_sg_io_pack_id(int *pack_id, void __user *buf, size_t count)
409{
410 struct sg_header __user *old_hdr = buf;
411 int reply_len;
412
413 if (count >= SZ_SG_HEADER) {
414 /* negative reply_len means v3 format, otherwise v1/v2 */
415 if (get_user(reply_len, &old_hdr->reply_len))
416 return -EFAULT;
417
418 if (reply_len >= 0)
419 return get_user(*pack_id, &old_hdr->pack_id);
420
421 if (in_compat_syscall() &&
422 count >= sizeof(struct compat_sg_io_hdr)) {
423 struct compat_sg_io_hdr __user *hp = buf;
424
425 return get_user(*pack_id, &hp->pack_id);
426 }
427
428 if (count >= sizeof(struct sg_io_hdr)) {
429 struct sg_io_hdr __user *hp = buf;
430
431 return get_user(*pack_id, &hp->pack_id);
432 }
433 }
434
435 /* no valid header was passed, so ignore the pack_id */
436 *pack_id = -1;
437 return 0;
438}
439
440static ssize_t
441sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
442{
443 Sg_device *sdp;
444 Sg_fd *sfp;
445 Sg_request *srp;
446 int req_pack_id = -1;
447 bool busy;
448 sg_io_hdr_t *hp;
449 struct sg_header *old_hdr;
450 int retval;
451
452 /*
453 * This could cause a response to be stranded. Close the associated
454 * file descriptor to free up any resources being held.
455 */
456 retval = sg_check_file_access(filp, __func__);
457 if (retval)
458 return retval;
459
460 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
461 return -ENXIO;
462 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
463 "sg_read: count=%d\n", (int) count));
464
465 if (sfp->force_packid)
466 retval = get_sg_io_pack_id(&req_pack_id, buf, count);
467 if (retval)
468 return retval;
469
470 srp = sg_get_rq_mark(sfp, req_pack_id, &busy);
471 if (!srp) { /* now wait on packet to arrive */
472 if (filp->f_flags & O_NONBLOCK)
473 return -EAGAIN;
474 retval = wait_event_interruptible(sfp->read_wait,
475 ((srp = sg_get_rq_mark(sfp, req_pack_id, &busy)) ||
476 (!busy && atomic_read(&sdp->detaching))));
477 if (!srp)
478 /* signal or detaching */
479 return retval ? retval : -ENODEV;
480 }
481 if (srp->header.interface_id != '\0')
482 return sg_new_read(sfp, buf, count, srp);
483
484 hp = &srp->header;
485 old_hdr = kzalloc(SZ_SG_HEADER, GFP_KERNEL);
486 if (!old_hdr)
487 return -ENOMEM;
488
489 old_hdr->reply_len = (int) hp->timeout;
490 old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
491 old_hdr->pack_id = hp->pack_id;
492 old_hdr->twelve_byte =
493 ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
494 old_hdr->target_status = hp->masked_status;
495 old_hdr->host_status = hp->host_status;
496 old_hdr->driver_status = hp->driver_status;
497 if ((CHECK_CONDITION & hp->masked_status) ||
498 (srp->sense_b[0] & 0x70) == 0x70) {
499 old_hdr->driver_status = DRIVER_SENSE;
500 memcpy(old_hdr->sense_buffer, srp->sense_b,
501 sizeof (old_hdr->sense_buffer));
502 }
503 switch (hp->host_status) {
504 /* This setup of 'result' is for backward compatibility and is best
505 ignored by the user who should use target, host + driver status */
506 case DID_OK:
507 case DID_PASSTHROUGH:
508 case DID_SOFT_ERROR:
509 old_hdr->result = 0;
510 break;
511 case DID_NO_CONNECT:
512 case DID_BUS_BUSY:
513 case DID_TIME_OUT:
514 old_hdr->result = EBUSY;
515 break;
516 case DID_BAD_TARGET:
517 case DID_ABORT:
518 case DID_PARITY:
519 case DID_RESET:
520 case DID_BAD_INTR:
521 old_hdr->result = EIO;
522 break;
523 case DID_ERROR:
524 old_hdr->result = (srp->sense_b[0] == 0 &&
525 hp->masked_status == GOOD) ? 0 : EIO;
526 break;
527 default:
528 old_hdr->result = EIO;
529 break;
530 }
531
532 /* Now copy the result back to the user buffer. */
533 if (count >= SZ_SG_HEADER) {
534 if (copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
535 retval = -EFAULT;
536 goto free_old_hdr;
537 }
538 buf += SZ_SG_HEADER;
539 if (count > old_hdr->reply_len)
540 count = old_hdr->reply_len;
541 if (count > SZ_SG_HEADER) {
542 if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
543 retval = -EFAULT;
544 goto free_old_hdr;
545 }
546 }
547 } else
548 count = (old_hdr->result == 0) ? 0 : -EIO;
549 sg_finish_rem_req(srp);
550 sg_remove_request(sfp, srp);
551 retval = count;
552free_old_hdr:
553 kfree(old_hdr);
554 return retval;
555}
556
557static ssize_t
558sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
559{
560 sg_io_hdr_t *hp = &srp->header;
561 int err = 0, err2;
562 int len;
563
564 if (in_compat_syscall()) {
565 if (count < sizeof(struct compat_sg_io_hdr)) {
566 err = -EINVAL;
567 goto err_out;
568 }
569 } else if (count < SZ_SG_IO_HDR) {
570 err = -EINVAL;
571 goto err_out;
572 }
573 hp->sb_len_wr = 0;
574 if ((hp->mx_sb_len > 0) && hp->sbp) {
575 if ((CHECK_CONDITION & hp->masked_status) ||
576 (srp->sense_b[0] & 0x70) == 0x70) {
577 int sb_len = SCSI_SENSE_BUFFERSIZE;
578 sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
579 len = 8 + (int) srp->sense_b[7]; /* Additional sense length field */
580 len = (len > sb_len) ? sb_len : len;
581 if (copy_to_user(hp->sbp, srp->sense_b, len)) {
582 err = -EFAULT;
583 goto err_out;
584 }
585 hp->driver_status = DRIVER_SENSE;
586 hp->sb_len_wr = len;
587 }
588 }
589 if (hp->masked_status || hp->host_status || hp->driver_status)
590 hp->info |= SG_INFO_CHECK;
591 err = put_sg_io_hdr(hp, buf);
592err_out:
593 err2 = sg_finish_rem_req(srp);
594 sg_remove_request(sfp, srp);
595 return err ? : err2 ? : count;
596}
597
598static ssize_t
599sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
600{
601 int mxsize, cmd_size, k;
602 int input_size, blocking;
603 unsigned char opcode;
604 Sg_device *sdp;
605 Sg_fd *sfp;
606 Sg_request *srp;
607 struct sg_header old_hdr;
608 sg_io_hdr_t *hp;
609 unsigned char cmnd[SG_MAX_CDB_SIZE];
610 int retval;
611
612 retval = sg_check_file_access(filp, __func__);
613 if (retval)
614 return retval;
615
616 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
617 return -ENXIO;
618 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
619 "sg_write: count=%d\n", (int) count));
620 if (atomic_read(&sdp->detaching))
621 return -ENODEV;
622 if (!((filp->f_flags & O_NONBLOCK) ||
623 scsi_block_when_processing_errors(sdp->device)))
624 return -ENXIO;
625
626 if (count < SZ_SG_HEADER)
627 return -EIO;
628 if (copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
629 return -EFAULT;
630 blocking = !(filp->f_flags & O_NONBLOCK);
631 if (old_hdr.reply_len < 0)
632 return sg_new_write(sfp, filp, buf, count,
633 blocking, 0, 0, NULL);
634 if (count < (SZ_SG_HEADER + 6))
635 return -EIO; /* The minimum scsi command length is 6 bytes. */
636
637 buf += SZ_SG_HEADER;
638 if (get_user(opcode, buf))
639 return -EFAULT;
640
641 if (!(srp = sg_add_request(sfp))) {
642 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
643 "sg_write: queue full\n"));
644 return -EDOM;
645 }
646 mutex_lock(&sfp->f_mutex);
647 if (sfp->next_cmd_len > 0) {
648 cmd_size = sfp->next_cmd_len;
649 sfp->next_cmd_len = 0; /* reset so only this write() effected */
650 } else {
651 cmd_size = COMMAND_SIZE(opcode); /* based on SCSI command group */
652 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
653 cmd_size = 12;
654 }
655 mutex_unlock(&sfp->f_mutex);
656 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
657 "sg_write: scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
658/* Determine buffer size. */
659 input_size = count - cmd_size;
660 mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
661 mxsize -= SZ_SG_HEADER;
662 input_size -= SZ_SG_HEADER;
663 if (input_size < 0) {
664 sg_remove_request(sfp, srp);
665 return -EIO; /* User did not pass enough bytes for this command. */
666 }
667 hp = &srp->header;
668 hp->interface_id = '\0'; /* indicator of old interface tunnelled */
669 hp->cmd_len = (unsigned char) cmd_size;
670 hp->iovec_count = 0;
671 hp->mx_sb_len = 0;
672 if (input_size > 0)
673 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
674 SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
675 else
676 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
677 hp->dxfer_len = mxsize;
678 if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
679 (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
680 hp->dxferp = (char __user *)buf + cmd_size;
681 else
682 hp->dxferp = NULL;
683 hp->sbp = NULL;
684 hp->timeout = old_hdr.reply_len; /* structure abuse ... */
685 hp->flags = input_size; /* structure abuse ... */
686 hp->pack_id = old_hdr.pack_id;
687 hp->usr_ptr = NULL;
688 if (copy_from_user(cmnd, buf, cmd_size)) {
689 sg_remove_request(sfp, srp);
690 return -EFAULT;
691 }
692 /*
693 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
694 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
695 * is a non-zero input_size, so emit a warning.
696 */
697 if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
698 printk_ratelimited(KERN_WARNING
699 "sg_write: data in/out %d/%d bytes "
700 "for SCSI command 0x%x-- guessing "
701 "data in;\n program %s not setting "
702 "count and/or reply_len properly\n",
703 old_hdr.reply_len - (int)SZ_SG_HEADER,
704 input_size, (unsigned int) cmnd[0],
705 current->comm);
706 }
707 k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
708 return (k < 0) ? k : count;
709}
710
711static ssize_t
712sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
713 size_t count, int blocking, int read_only, int sg_io_owned,
714 Sg_request **o_srp)
715{
716 int k;
717 Sg_request *srp;
718 sg_io_hdr_t *hp;
719 unsigned char cmnd[SG_MAX_CDB_SIZE];
720 int timeout;
721 unsigned long ul_timeout;
722
723 if (count < SZ_SG_IO_HDR)
724 return -EINVAL;
725
726 sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
727 if (!(srp = sg_add_request(sfp))) {
728 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
729 "sg_new_write: queue full\n"));
730 return -EDOM;
731 }
732 srp->sg_io_owned = sg_io_owned;
733 hp = &srp->header;
734 if (get_sg_io_hdr(hp, buf)) {
735 sg_remove_request(sfp, srp);
736 return -EFAULT;
737 }
738 if (hp->interface_id != 'S') {
739 sg_remove_request(sfp, srp);
740 return -ENOSYS;
741 }
742 if (hp->flags & SG_FLAG_MMAP_IO) {
743 if (hp->dxfer_len > sfp->reserve.bufflen) {
744 sg_remove_request(sfp, srp);
745 return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
746 }
747 if (hp->flags & SG_FLAG_DIRECT_IO) {
748 sg_remove_request(sfp, srp);
749 return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
750 }
751 if (sfp->res_in_use) {
752 sg_remove_request(sfp, srp);
753 return -EBUSY; /* reserve buffer already being used */
754 }
755 }
756 ul_timeout = msecs_to_jiffies(srp->header.timeout);
757 timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
758 if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
759 sg_remove_request(sfp, srp);
760 return -EMSGSIZE;
761 }
762 if (copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
763 sg_remove_request(sfp, srp);
764 return -EFAULT;
765 }
766 if (read_only && sg_allow_access(file, cmnd)) {
767 sg_remove_request(sfp, srp);
768 return -EPERM;
769 }
770 k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
771 if (k < 0)
772 return k;
773 if (o_srp)
774 *o_srp = srp;
775 return count;
776}
777
778static int
779sg_common_write(Sg_fd * sfp, Sg_request * srp,
780 unsigned char *cmnd, int timeout, int blocking)
781{
782 int k, at_head;
783 Sg_device *sdp = sfp->parentdp;
784 sg_io_hdr_t *hp = &srp->header;
785
786 srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
787 hp->status = 0;
788 hp->masked_status = 0;
789 hp->msg_status = 0;
790 hp->info = 0;
791 hp->host_status = 0;
792 hp->driver_status = 0;
793 hp->resid = 0;
794 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
795 "sg_common_write: scsi opcode=0x%02x, cmd_size=%d\n",
796 (int) cmnd[0], (int) hp->cmd_len));
797
798 if (hp->dxfer_len >= SZ_256M) {
799 sg_remove_request(sfp, srp);
800 return -EINVAL;
801 }
802
803 k = sg_start_req(srp, cmnd);
804 if (k) {
805 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
806 "sg_common_write: start_req err=%d\n", k));
807 sg_finish_rem_req(srp);
808 sg_remove_request(sfp, srp);
809 return k; /* probably out of space --> ENOMEM */
810 }
811 if (atomic_read(&sdp->detaching)) {
812 if (srp->bio) {
813 blk_mq_free_request(srp->rq);
814 srp->rq = NULL;
815 }
816
817 sg_finish_rem_req(srp);
818 sg_remove_request(sfp, srp);
819 return -ENODEV;
820 }
821
822 hp->duration = jiffies_to_msecs(jiffies);
823 if (hp->interface_id != '\0' && /* v3 (or later) interface */
824 (SG_FLAG_Q_AT_TAIL & hp->flags))
825 at_head = 0;
826 else
827 at_head = 1;
828
829 srp->rq->timeout = timeout;
830 kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
831 srp->rq->end_io = sg_rq_end_io;
832 blk_execute_rq_nowait(srp->rq, at_head);
833 return 0;
834}
835
836static int srp_done(Sg_fd *sfp, Sg_request *srp)
837{
838 unsigned long flags;
839 int ret;
840
841 read_lock_irqsave(&sfp->rq_list_lock, flags);
842 ret = srp->done;
843 read_unlock_irqrestore(&sfp->rq_list_lock, flags);
844 return ret;
845}
846
847static int max_sectors_bytes(struct request_queue *q)
848{
849 unsigned int max_sectors = queue_max_sectors(q);
850
851 max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
852
853 return max_sectors << 9;
854}
855
856static void
857sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
858{
859 Sg_request *srp;
860 int val;
861 unsigned int ms;
862
863 val = 0;
864 list_for_each_entry(srp, &sfp->rq_list, entry) {
865 if (val >= SG_MAX_QUEUE)
866 break;
867 rinfo[val].req_state = srp->done + 1;
868 rinfo[val].problem =
869 srp->header.masked_status &
870 srp->header.host_status &
871 srp->header.driver_status;
872 if (srp->done)
873 rinfo[val].duration =
874 srp->header.duration;
875 else {
876 ms = jiffies_to_msecs(jiffies);
877 rinfo[val].duration =
878 (ms > srp->header.duration) ?
879 (ms - srp->header.duration) : 0;
880 }
881 rinfo[val].orphan = srp->orphan;
882 rinfo[val].sg_io_owned = srp->sg_io_owned;
883 rinfo[val].pack_id = srp->header.pack_id;
884 rinfo[val].usr_ptr = srp->header.usr_ptr;
885 val++;
886 }
887}
888
889#ifdef CONFIG_COMPAT
890struct compat_sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
891 char req_state;
892 char orphan;
893 char sg_io_owned;
894 char problem;
895 int pack_id;
896 compat_uptr_t usr_ptr;
897 unsigned int duration;
898 int unused;
899};
900
901static int put_compat_request_table(struct compat_sg_req_info __user *o,
902 struct sg_req_info *rinfo)
903{
904 int i;
905 for (i = 0; i < SG_MAX_QUEUE; i++) {
906 if (copy_to_user(o + i, rinfo + i, offsetof(sg_req_info_t, usr_ptr)) ||
907 put_user((uintptr_t)rinfo[i].usr_ptr, &o[i].usr_ptr) ||
908 put_user(rinfo[i].duration, &o[i].duration) ||
909 put_user(rinfo[i].unused, &o[i].unused))
910 return -EFAULT;
911 }
912 return 0;
913}
914#endif
915
916static long
917sg_ioctl_common(struct file *filp, Sg_device *sdp, Sg_fd *sfp,
918 unsigned int cmd_in, void __user *p)
919{
920 int __user *ip = p;
921 int result, val, read_only;
922 Sg_request *srp;
923 unsigned long iflags;
924
925 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
926 "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
927 read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
928
929 switch (cmd_in) {
930 case SG_IO:
931 if (atomic_read(&sdp->detaching))
932 return -ENODEV;
933 if (!scsi_block_when_processing_errors(sdp->device))
934 return -ENXIO;
935 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
936 1, read_only, 1, &srp);
937 if (result < 0)
938 return result;
939 result = wait_event_interruptible(sfp->read_wait,
940 srp_done(sfp, srp));
941 write_lock_irq(&sfp->rq_list_lock);
942 if (srp->done) {
943 srp->done = 2;
944 write_unlock_irq(&sfp->rq_list_lock);
945 result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
946 return (result < 0) ? result : 0;
947 }
948 srp->orphan = 1;
949 write_unlock_irq(&sfp->rq_list_lock);
950 return result; /* -ERESTARTSYS because signal hit process */
951 case SG_SET_TIMEOUT:
952 result = get_user(val, ip);
953 if (result)
954 return result;
955 if (val < 0)
956 return -EIO;
957 if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
958 val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
959 INT_MAX);
960 sfp->timeout_user = val;
961 sfp->timeout = mult_frac(val, HZ, USER_HZ);
962
963 return 0;
964 case SG_GET_TIMEOUT: /* N.B. User receives timeout as return value */
965 /* strange ..., for backward compatibility */
966 return sfp->timeout_user;
967 case SG_SET_FORCE_LOW_DMA:
968 /*
969 * N.B. This ioctl never worked properly, but failed to
970 * return an error value. So returning '0' to keep compability
971 * with legacy applications.
972 */
973 return 0;
974 case SG_GET_LOW_DMA:
975 return put_user(0, ip);
976 case SG_GET_SCSI_ID:
977 {
978 sg_scsi_id_t v;
979
980 if (atomic_read(&sdp->detaching))
981 return -ENODEV;
982 memset(&v, 0, sizeof(v));
983 v.host_no = sdp->device->host->host_no;
984 v.channel = sdp->device->channel;
985 v.scsi_id = sdp->device->id;
986 v.lun = sdp->device->lun;
987 v.scsi_type = sdp->device->type;
988 v.h_cmd_per_lun = sdp->device->host->cmd_per_lun;
989 v.d_queue_depth = sdp->device->queue_depth;
990 if (copy_to_user(p, &v, sizeof(sg_scsi_id_t)))
991 return -EFAULT;
992 return 0;
993 }
994 case SG_SET_FORCE_PACK_ID:
995 result = get_user(val, ip);
996 if (result)
997 return result;
998 sfp->force_packid = val ? 1 : 0;
999 return 0;
1000 case SG_GET_PACK_ID:
1001 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1002 list_for_each_entry(srp, &sfp->rq_list, entry) {
1003 if ((1 == srp->done) && (!srp->sg_io_owned)) {
1004 read_unlock_irqrestore(&sfp->rq_list_lock,
1005 iflags);
1006 return put_user(srp->header.pack_id, ip);
1007 }
1008 }
1009 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1010 return put_user(-1, ip);
1011 case SG_GET_NUM_WAITING:
1012 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1013 val = 0;
1014 list_for_each_entry(srp, &sfp->rq_list, entry) {
1015 if ((1 == srp->done) && (!srp->sg_io_owned))
1016 ++val;
1017 }
1018 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1019 return put_user(val, ip);
1020 case SG_GET_SG_TABLESIZE:
1021 return put_user(sdp->sg_tablesize, ip);
1022 case SG_SET_RESERVED_SIZE:
1023 result = get_user(val, ip);
1024 if (result)
1025 return result;
1026 if (val < 0)
1027 return -EINVAL;
1028 val = min_t(int, val,
1029 max_sectors_bytes(sdp->device->request_queue));
1030 mutex_lock(&sfp->f_mutex);
1031 if (val != sfp->reserve.bufflen) {
1032 if (sfp->mmap_called ||
1033 sfp->res_in_use) {
1034 mutex_unlock(&sfp->f_mutex);
1035 return -EBUSY;
1036 }
1037
1038 sg_remove_scat(sfp, &sfp->reserve);
1039 sg_build_reserve(sfp, val);
1040 }
1041 mutex_unlock(&sfp->f_mutex);
1042 return 0;
1043 case SG_GET_RESERVED_SIZE:
1044 val = min_t(int, sfp->reserve.bufflen,
1045 max_sectors_bytes(sdp->device->request_queue));
1046 return put_user(val, ip);
1047 case SG_SET_COMMAND_Q:
1048 result = get_user(val, ip);
1049 if (result)
1050 return result;
1051 sfp->cmd_q = val ? 1 : 0;
1052 return 0;
1053 case SG_GET_COMMAND_Q:
1054 return put_user((int) sfp->cmd_q, ip);
1055 case SG_SET_KEEP_ORPHAN:
1056 result = get_user(val, ip);
1057 if (result)
1058 return result;
1059 sfp->keep_orphan = val;
1060 return 0;
1061 case SG_GET_KEEP_ORPHAN:
1062 return put_user((int) sfp->keep_orphan, ip);
1063 case SG_NEXT_CMD_LEN:
1064 result = get_user(val, ip);
1065 if (result)
1066 return result;
1067 if (val > SG_MAX_CDB_SIZE)
1068 return -ENOMEM;
1069 sfp->next_cmd_len = (val > 0) ? val : 0;
1070 return 0;
1071 case SG_GET_VERSION_NUM:
1072 return put_user(sg_version_num, ip);
1073 case SG_GET_ACCESS_COUNT:
1074 /* faked - we don't have a real access count anymore */
1075 val = (sdp->device ? 1 : 0);
1076 return put_user(val, ip);
1077 case SG_GET_REQUEST_TABLE:
1078 {
1079 sg_req_info_t *rinfo;
1080
1081 rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
1082 GFP_KERNEL);
1083 if (!rinfo)
1084 return -ENOMEM;
1085 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1086 sg_fill_request_table(sfp, rinfo);
1087 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1088 #ifdef CONFIG_COMPAT
1089 if (in_compat_syscall())
1090 result = put_compat_request_table(p, rinfo);
1091 else
1092 #endif
1093 result = copy_to_user(p, rinfo,
1094 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1095 result = result ? -EFAULT : 0;
1096 kfree(rinfo);
1097 return result;
1098 }
1099 case SG_EMULATED_HOST:
1100 if (atomic_read(&sdp->detaching))
1101 return -ENODEV;
1102 return put_user(sdp->device->host->hostt->emulated, ip);
1103 case SCSI_IOCTL_SEND_COMMAND:
1104 if (atomic_read(&sdp->detaching))
1105 return -ENODEV;
1106 return scsi_ioctl(sdp->device, filp->f_mode & FMODE_WRITE,
1107 cmd_in, p);
1108 case SG_SET_DEBUG:
1109 result = get_user(val, ip);
1110 if (result)
1111 return result;
1112 sdp->sgdebug = (char) val;
1113 return 0;
1114 case BLKSECTGET:
1115 return put_user(max_sectors_bytes(sdp->device->request_queue),
1116 ip);
1117 case BLKTRACESETUP:
1118 return blk_trace_setup(sdp->device->request_queue, sdp->name,
1119 MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1120 NULL, p);
1121 case BLKTRACESTART:
1122 return blk_trace_startstop(sdp->device->request_queue, 1);
1123 case BLKTRACESTOP:
1124 return blk_trace_startstop(sdp->device->request_queue, 0);
1125 case BLKTRACETEARDOWN:
1126 return blk_trace_remove(sdp->device->request_queue);
1127 case SCSI_IOCTL_GET_IDLUN:
1128 case SCSI_IOCTL_GET_BUS_NUMBER:
1129 case SCSI_IOCTL_PROBE_HOST:
1130 case SG_GET_TRANSFORM:
1131 case SG_SCSI_RESET:
1132 if (atomic_read(&sdp->detaching))
1133 return -ENODEV;
1134 break;
1135 default:
1136 if (read_only)
1137 return -EPERM; /* don't know so take safe approach */
1138 break;
1139 }
1140
1141 result = scsi_ioctl_block_when_processing_errors(sdp->device,
1142 cmd_in, filp->f_flags & O_NDELAY);
1143 if (result)
1144 return result;
1145
1146 return -ENOIOCTLCMD;
1147}
1148
1149static long
1150sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1151{
1152 void __user *p = (void __user *)arg;
1153 Sg_device *sdp;
1154 Sg_fd *sfp;
1155 int ret;
1156
1157 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1158 return -ENXIO;
1159
1160 ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
1161 if (ret != -ENOIOCTLCMD)
1162 return ret;
1163 return scsi_ioctl(sdp->device, filp->f_mode & FMODE_WRITE, cmd_in, p);
1164}
1165
1166static __poll_t
1167sg_poll(struct file *filp, poll_table * wait)
1168{
1169 __poll_t res = 0;
1170 Sg_device *sdp;
1171 Sg_fd *sfp;
1172 Sg_request *srp;
1173 int count = 0;
1174 unsigned long iflags;
1175
1176 sfp = filp->private_data;
1177 if (!sfp)
1178 return EPOLLERR;
1179 sdp = sfp->parentdp;
1180 if (!sdp)
1181 return EPOLLERR;
1182 poll_wait(filp, &sfp->read_wait, wait);
1183 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1184 list_for_each_entry(srp, &sfp->rq_list, entry) {
1185 /* if any read waiting, flag it */
1186 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1187 res = EPOLLIN | EPOLLRDNORM;
1188 ++count;
1189 }
1190 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1191
1192 if (atomic_read(&sdp->detaching))
1193 res |= EPOLLHUP;
1194 else if (!sfp->cmd_q) {
1195 if (0 == count)
1196 res |= EPOLLOUT | EPOLLWRNORM;
1197 } else if (count < SG_MAX_QUEUE)
1198 res |= EPOLLOUT | EPOLLWRNORM;
1199 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1200 "sg_poll: res=0x%x\n", (__force u32) res));
1201 return res;
1202}
1203
1204static int
1205sg_fasync(int fd, struct file *filp, int mode)
1206{
1207 Sg_device *sdp;
1208 Sg_fd *sfp;
1209
1210 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1211 return -ENXIO;
1212 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1213 "sg_fasync: mode=%d\n", mode));
1214
1215 return fasync_helper(fd, filp, mode, &sfp->async_qp);
1216}
1217
1218static vm_fault_t
1219sg_vma_fault(struct vm_fault *vmf)
1220{
1221 struct vm_area_struct *vma = vmf->vma;
1222 Sg_fd *sfp;
1223 unsigned long offset, len, sa;
1224 Sg_scatter_hold *rsv_schp;
1225 int k, length;
1226
1227 if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1228 return VM_FAULT_SIGBUS;
1229 rsv_schp = &sfp->reserve;
1230 offset = vmf->pgoff << PAGE_SHIFT;
1231 if (offset >= rsv_schp->bufflen)
1232 return VM_FAULT_SIGBUS;
1233 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1234 "sg_vma_fault: offset=%lu, scatg=%d\n",
1235 offset, rsv_schp->k_use_sg));
1236 sa = vma->vm_start;
1237 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1238 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1239 len = vma->vm_end - sa;
1240 len = (len < length) ? len : length;
1241 if (offset < len) {
1242 struct page *page = nth_page(rsv_schp->pages[k],
1243 offset >> PAGE_SHIFT);
1244 get_page(page); /* increment page count */
1245 vmf->page = page;
1246 return 0; /* success */
1247 }
1248 sa += len;
1249 offset -= len;
1250 }
1251
1252 return VM_FAULT_SIGBUS;
1253}
1254
1255static const struct vm_operations_struct sg_mmap_vm_ops = {
1256 .fault = sg_vma_fault,
1257};
1258
1259static int
1260sg_mmap(struct file *filp, struct vm_area_struct *vma)
1261{
1262 Sg_fd *sfp;
1263 unsigned long req_sz, len, sa;
1264 Sg_scatter_hold *rsv_schp;
1265 int k, length;
1266 int ret = 0;
1267
1268 if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1269 return -ENXIO;
1270 req_sz = vma->vm_end - vma->vm_start;
1271 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1272 "sg_mmap starting, vm_start=%p, len=%d\n",
1273 (void *) vma->vm_start, (int) req_sz));
1274 if (vma->vm_pgoff)
1275 return -EINVAL; /* want no offset */
1276 rsv_schp = &sfp->reserve;
1277 mutex_lock(&sfp->f_mutex);
1278 if (req_sz > rsv_schp->bufflen) {
1279 ret = -ENOMEM; /* cannot map more than reserved buffer */
1280 goto out;
1281 }
1282
1283 sa = vma->vm_start;
1284 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1285 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1286 len = vma->vm_end - sa;
1287 len = (len < length) ? len : length;
1288 sa += len;
1289 }
1290
1291 sfp->mmap_called = 1;
1292 vm_flags_set(vma, VM_IO | VM_DONTEXPAND | VM_DONTDUMP);
1293 vma->vm_private_data = sfp;
1294 vma->vm_ops = &sg_mmap_vm_ops;
1295out:
1296 mutex_unlock(&sfp->f_mutex);
1297 return ret;
1298}
1299
1300static void
1301sg_rq_end_io_usercontext(struct work_struct *work)
1302{
1303 struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1304 struct sg_fd *sfp = srp->parentfp;
1305
1306 sg_finish_rem_req(srp);
1307 sg_remove_request(sfp, srp);
1308 kref_put(&sfp->f_ref, sg_remove_sfp);
1309}
1310
1311/*
1312 * This function is a "bottom half" handler that is called by the mid
1313 * level when a command is completed (or has failed).
1314 */
1315static enum rq_end_io_ret
1316sg_rq_end_io(struct request *rq, blk_status_t status)
1317{
1318 struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
1319 struct sg_request *srp = rq->end_io_data;
1320 Sg_device *sdp;
1321 Sg_fd *sfp;
1322 unsigned long iflags;
1323 unsigned int ms;
1324 char *sense;
1325 int result, resid, done = 1;
1326
1327 if (WARN_ON(srp->done != 0))
1328 return RQ_END_IO_NONE;
1329
1330 sfp = srp->parentfp;
1331 if (WARN_ON(sfp == NULL))
1332 return RQ_END_IO_NONE;
1333
1334 sdp = sfp->parentdp;
1335 if (unlikely(atomic_read(&sdp->detaching)))
1336 pr_info("%s: device detaching\n", __func__);
1337
1338 sense = scmd->sense_buffer;
1339 result = scmd->result;
1340 resid = scmd->resid_len;
1341
1342 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1343 "sg_cmd_done: pack_id=%d, res=0x%x\n",
1344 srp->header.pack_id, result));
1345 srp->header.resid = resid;
1346 ms = jiffies_to_msecs(jiffies);
1347 srp->header.duration = (ms > srp->header.duration) ?
1348 (ms - srp->header.duration) : 0;
1349 if (0 != result) {
1350 struct scsi_sense_hdr sshdr;
1351
1352 srp->header.status = 0xff & result;
1353 srp->header.masked_status = sg_status_byte(result);
1354 srp->header.msg_status = COMMAND_COMPLETE;
1355 srp->header.host_status = host_byte(result);
1356 srp->header.driver_status = driver_byte(result);
1357 if ((sdp->sgdebug > 0) &&
1358 ((CHECK_CONDITION == srp->header.masked_status) ||
1359 (COMMAND_TERMINATED == srp->header.masked_status)))
1360 __scsi_print_sense(sdp->device, __func__, sense,
1361 SCSI_SENSE_BUFFERSIZE);
1362
1363 /* Following if statement is a patch supplied by Eric Youngdale */
1364 if (driver_byte(result) != 0
1365 && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1366 && !scsi_sense_is_deferred(&sshdr)
1367 && sshdr.sense_key == UNIT_ATTENTION
1368 && sdp->device->removable) {
1369 /* Detected possible disc change. Set the bit - this */
1370 /* may be used if there are filesystems using this device */
1371 sdp->device->changed = 1;
1372 }
1373 }
1374
1375 if (scmd->sense_len)
1376 memcpy(srp->sense_b, scmd->sense_buffer, SCSI_SENSE_BUFFERSIZE);
1377
1378 /* Rely on write phase to clean out srp status values, so no "else" */
1379
1380 /*
1381 * Free the request as soon as it is complete so that its resources
1382 * can be reused without waiting for userspace to read() the
1383 * result. But keep the associated bio (if any) around until
1384 * blk_rq_unmap_user() can be called from user context.
1385 */
1386 srp->rq = NULL;
1387 blk_mq_free_request(rq);
1388
1389 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1390 if (unlikely(srp->orphan)) {
1391 if (sfp->keep_orphan)
1392 srp->sg_io_owned = 0;
1393 else
1394 done = 0;
1395 }
1396 srp->done = done;
1397 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1398
1399 if (likely(done)) {
1400 /* Now wake up any sg_read() that is waiting for this
1401 * packet.
1402 */
1403 wake_up_interruptible(&sfp->read_wait);
1404 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1405 kref_put(&sfp->f_ref, sg_remove_sfp);
1406 } else {
1407 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1408 schedule_work(&srp->ew.work);
1409 }
1410 return RQ_END_IO_NONE;
1411}
1412
1413static const struct file_operations sg_fops = {
1414 .owner = THIS_MODULE,
1415 .read = sg_read,
1416 .write = sg_write,
1417 .poll = sg_poll,
1418 .unlocked_ioctl = sg_ioctl,
1419 .compat_ioctl = compat_ptr_ioctl,
1420 .open = sg_open,
1421 .mmap = sg_mmap,
1422 .release = sg_release,
1423 .fasync = sg_fasync,
1424 .llseek = no_llseek,
1425};
1426
1427static struct class *sg_sysfs_class;
1428
1429static int sg_sysfs_valid = 0;
1430
1431static Sg_device *
1432sg_alloc(struct scsi_device *scsidp)
1433{
1434 struct request_queue *q = scsidp->request_queue;
1435 Sg_device *sdp;
1436 unsigned long iflags;
1437 int error;
1438 u32 k;
1439
1440 sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1441 if (!sdp) {
1442 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1443 "failure\n", __func__);
1444 return ERR_PTR(-ENOMEM);
1445 }
1446
1447 idr_preload(GFP_KERNEL);
1448 write_lock_irqsave(&sg_index_lock, iflags);
1449
1450 error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1451 if (error < 0) {
1452 if (error == -ENOSPC) {
1453 sdev_printk(KERN_WARNING, scsidp,
1454 "Unable to attach sg device type=%d, minor number exceeds %d\n",
1455 scsidp->type, SG_MAX_DEVS - 1);
1456 error = -ENODEV;
1457 } else {
1458 sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1459 "allocation Sg_device failure: %d\n",
1460 __func__, error);
1461 }
1462 goto out_unlock;
1463 }
1464 k = error;
1465
1466 SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1467 "sg_alloc: dev=%d \n", k));
1468 sprintf(sdp->name, "sg%d", k);
1469 sdp->device = scsidp;
1470 mutex_init(&sdp->open_rel_lock);
1471 INIT_LIST_HEAD(&sdp->sfds);
1472 init_waitqueue_head(&sdp->open_wait);
1473 atomic_set(&sdp->detaching, 0);
1474 rwlock_init(&sdp->sfd_lock);
1475 sdp->sg_tablesize = queue_max_segments(q);
1476 sdp->index = k;
1477 kref_init(&sdp->d_ref);
1478 error = 0;
1479
1480out_unlock:
1481 write_unlock_irqrestore(&sg_index_lock, iflags);
1482 idr_preload_end();
1483
1484 if (error) {
1485 kfree(sdp);
1486 return ERR_PTR(error);
1487 }
1488 return sdp;
1489}
1490
1491static int
1492sg_add_device(struct device *cl_dev)
1493{
1494 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1495 Sg_device *sdp = NULL;
1496 struct cdev * cdev = NULL;
1497 int error;
1498 unsigned long iflags;
1499
1500 if (!blk_get_queue(scsidp->request_queue)) {
1501 pr_warn("%s: get scsi_device queue failed\n", __func__);
1502 return -ENODEV;
1503 }
1504
1505 error = -ENOMEM;
1506 cdev = cdev_alloc();
1507 if (!cdev) {
1508 pr_warn("%s: cdev_alloc failed\n", __func__);
1509 goto out;
1510 }
1511 cdev->owner = THIS_MODULE;
1512 cdev->ops = &sg_fops;
1513
1514 sdp = sg_alloc(scsidp);
1515 if (IS_ERR(sdp)) {
1516 pr_warn("%s: sg_alloc failed\n", __func__);
1517 error = PTR_ERR(sdp);
1518 goto out;
1519 }
1520
1521 error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1522 if (error)
1523 goto cdev_add_err;
1524
1525 sdp->cdev = cdev;
1526 if (sg_sysfs_valid) {
1527 struct device *sg_class_member;
1528
1529 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1530 MKDEV(SCSI_GENERIC_MAJOR,
1531 sdp->index),
1532 sdp, "%s", sdp->name);
1533 if (IS_ERR(sg_class_member)) {
1534 pr_err("%s: device_create failed\n", __func__);
1535 error = PTR_ERR(sg_class_member);
1536 goto cdev_add_err;
1537 }
1538 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1539 &sg_class_member->kobj, "generic");
1540 if (error)
1541 pr_err("%s: unable to make symlink 'generic' back "
1542 "to sg%d\n", __func__, sdp->index);
1543 } else
1544 pr_warn("%s: sg_sys Invalid\n", __func__);
1545
1546 sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1547 "type %d\n", sdp->index, scsidp->type);
1548
1549 dev_set_drvdata(cl_dev, sdp);
1550
1551 return 0;
1552
1553cdev_add_err:
1554 write_lock_irqsave(&sg_index_lock, iflags);
1555 idr_remove(&sg_index_idr, sdp->index);
1556 write_unlock_irqrestore(&sg_index_lock, iflags);
1557 kfree(sdp);
1558
1559out:
1560 if (cdev)
1561 cdev_del(cdev);
1562 blk_put_queue(scsidp->request_queue);
1563 return error;
1564}
1565
1566static void
1567sg_device_destroy(struct kref *kref)
1568{
1569 struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1570 struct request_queue *q = sdp->device->request_queue;
1571 unsigned long flags;
1572
1573 /* CAUTION! Note that the device can still be found via idr_find()
1574 * even though the refcount is 0. Therefore, do idr_remove() BEFORE
1575 * any other cleanup.
1576 */
1577
1578 blk_trace_remove(q);
1579 blk_put_queue(q);
1580
1581 write_lock_irqsave(&sg_index_lock, flags);
1582 idr_remove(&sg_index_idr, sdp->index);
1583 write_unlock_irqrestore(&sg_index_lock, flags);
1584
1585 SCSI_LOG_TIMEOUT(3,
1586 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1587
1588 kfree(sdp);
1589}
1590
1591static void
1592sg_remove_device(struct device *cl_dev)
1593{
1594 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1595 Sg_device *sdp = dev_get_drvdata(cl_dev);
1596 unsigned long iflags;
1597 Sg_fd *sfp;
1598 int val;
1599
1600 if (!sdp)
1601 return;
1602 /* want sdp->detaching non-zero as soon as possible */
1603 val = atomic_inc_return(&sdp->detaching);
1604 if (val > 1)
1605 return; /* only want to do following once per device */
1606
1607 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1608 "%s\n", __func__));
1609
1610 read_lock_irqsave(&sdp->sfd_lock, iflags);
1611 list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1612 wake_up_interruptible_all(&sfp->read_wait);
1613 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1614 }
1615 wake_up_interruptible_all(&sdp->open_wait);
1616 read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1617
1618 sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1619 device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1620 cdev_del(sdp->cdev);
1621 sdp->cdev = NULL;
1622
1623 kref_put(&sdp->d_ref, sg_device_destroy);
1624}
1625
1626module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1627module_param_named(def_reserved_size, def_reserved_size, int,
1628 S_IRUGO | S_IWUSR);
1629module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1630
1631MODULE_AUTHOR("Douglas Gilbert");
1632MODULE_DESCRIPTION("SCSI generic (sg) driver");
1633MODULE_LICENSE("GPL");
1634MODULE_VERSION(SG_VERSION_STR);
1635MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1636
1637MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1638 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1639MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1640MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1641
1642#ifdef CONFIG_SYSCTL
1643#include <linux/sysctl.h>
1644
1645static struct ctl_table sg_sysctls[] = {
1646 {
1647 .procname = "sg-big-buff",
1648 .data = &sg_big_buff,
1649 .maxlen = sizeof(int),
1650 .mode = 0444,
1651 .proc_handler = proc_dointvec,
1652 },
1653};
1654
1655static struct ctl_table_header *hdr;
1656static void register_sg_sysctls(void)
1657{
1658 if (!hdr)
1659 hdr = register_sysctl("kernel", sg_sysctls);
1660}
1661
1662static void unregister_sg_sysctls(void)
1663{
1664 if (hdr)
1665 unregister_sysctl_table(hdr);
1666}
1667#else
1668#define register_sg_sysctls() do { } while (0)
1669#define unregister_sg_sysctls() do { } while (0)
1670#endif /* CONFIG_SYSCTL */
1671
1672static int __init
1673init_sg(void)
1674{
1675 int rc;
1676
1677 if (scatter_elem_sz < PAGE_SIZE) {
1678 scatter_elem_sz = PAGE_SIZE;
1679 scatter_elem_sz_prev = scatter_elem_sz;
1680 }
1681 if (def_reserved_size >= 0)
1682 sg_big_buff = def_reserved_size;
1683 else
1684 def_reserved_size = sg_big_buff;
1685
1686 rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1687 SG_MAX_DEVS, "sg");
1688 if (rc)
1689 return rc;
1690 sg_sysfs_class = class_create("scsi_generic");
1691 if ( IS_ERR(sg_sysfs_class) ) {
1692 rc = PTR_ERR(sg_sysfs_class);
1693 goto err_out;
1694 }
1695 sg_sysfs_valid = 1;
1696 rc = scsi_register_interface(&sg_interface);
1697 if (0 == rc) {
1698#ifdef CONFIG_SCSI_PROC_FS
1699 sg_proc_init();
1700#endif /* CONFIG_SCSI_PROC_FS */
1701 return 0;
1702 }
1703 class_destroy(sg_sysfs_class);
1704 register_sg_sysctls();
1705err_out:
1706 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1707 return rc;
1708}
1709
1710static void __exit
1711exit_sg(void)
1712{
1713 unregister_sg_sysctls();
1714#ifdef CONFIG_SCSI_PROC_FS
1715 remove_proc_subtree("scsi/sg", NULL);
1716#endif /* CONFIG_SCSI_PROC_FS */
1717 scsi_unregister_interface(&sg_interface);
1718 class_destroy(sg_sysfs_class);
1719 sg_sysfs_valid = 0;
1720 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1721 SG_MAX_DEVS);
1722 idr_destroy(&sg_index_idr);
1723}
1724
1725static int
1726sg_start_req(Sg_request *srp, unsigned char *cmd)
1727{
1728 int res;
1729 struct request *rq;
1730 Sg_fd *sfp = srp->parentfp;
1731 sg_io_hdr_t *hp = &srp->header;
1732 int dxfer_len = (int) hp->dxfer_len;
1733 int dxfer_dir = hp->dxfer_direction;
1734 unsigned int iov_count = hp->iovec_count;
1735 Sg_scatter_hold *req_schp = &srp->data;
1736 Sg_scatter_hold *rsv_schp = &sfp->reserve;
1737 struct request_queue *q = sfp->parentdp->device->request_queue;
1738 struct rq_map_data *md, map_data;
1739 int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? ITER_SOURCE : ITER_DEST;
1740 struct scsi_cmnd *scmd;
1741
1742 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1743 "sg_start_req: dxfer_len=%d\n",
1744 dxfer_len));
1745
1746 /*
1747 * NOTE
1748 *
1749 * With scsi-mq enabled, there are a fixed number of preallocated
1750 * requests equal in number to shost->can_queue. If all of the
1751 * preallocated requests are already in use, then scsi_alloc_request()
1752 * will sleep until an active command completes, freeing up a request.
1753 * Although waiting in an asynchronous interface is less than ideal, we
1754 * do not want to use BLK_MQ_REQ_NOWAIT here because userspace might
1755 * not expect an EWOULDBLOCK from this condition.
1756 */
1757 rq = scsi_alloc_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
1758 REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
1759 if (IS_ERR(rq))
1760 return PTR_ERR(rq);
1761 scmd = blk_mq_rq_to_pdu(rq);
1762
1763 if (hp->cmd_len > sizeof(scmd->cmnd)) {
1764 blk_mq_free_request(rq);
1765 return -EINVAL;
1766 }
1767
1768 memcpy(scmd->cmnd, cmd, hp->cmd_len);
1769 scmd->cmd_len = hp->cmd_len;
1770
1771 srp->rq = rq;
1772 rq->end_io_data = srp;
1773 scmd->allowed = SG_DEFAULT_RETRIES;
1774
1775 if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1776 return 0;
1777
1778 if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1779 dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1780 blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1781 md = NULL;
1782 else
1783 md = &map_data;
1784
1785 if (md) {
1786 mutex_lock(&sfp->f_mutex);
1787 if (dxfer_len <= rsv_schp->bufflen &&
1788 !sfp->res_in_use) {
1789 sfp->res_in_use = 1;
1790 sg_link_reserve(sfp, srp, dxfer_len);
1791 } else if (hp->flags & SG_FLAG_MMAP_IO) {
1792 res = -EBUSY; /* sfp->res_in_use == 1 */
1793 if (dxfer_len > rsv_schp->bufflen)
1794 res = -ENOMEM;
1795 mutex_unlock(&sfp->f_mutex);
1796 return res;
1797 } else {
1798 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1799 if (res) {
1800 mutex_unlock(&sfp->f_mutex);
1801 return res;
1802 }
1803 }
1804 mutex_unlock(&sfp->f_mutex);
1805
1806 md->pages = req_schp->pages;
1807 md->page_order = req_schp->page_order;
1808 md->nr_entries = req_schp->k_use_sg;
1809 md->offset = 0;
1810 md->null_mapped = hp->dxferp ? 0 : 1;
1811 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1812 md->from_user = 1;
1813 else
1814 md->from_user = 0;
1815 }
1816
1817 res = blk_rq_map_user_io(rq, md, hp->dxferp, hp->dxfer_len,
1818 GFP_ATOMIC, iov_count, iov_count, 1, rw);
1819 if (!res) {
1820 srp->bio = rq->bio;
1821
1822 if (!md) {
1823 req_schp->dio_in_use = 1;
1824 hp->info |= SG_INFO_DIRECT_IO;
1825 }
1826 }
1827 return res;
1828}
1829
1830static int
1831sg_finish_rem_req(Sg_request *srp)
1832{
1833 int ret = 0;
1834
1835 Sg_fd *sfp = srp->parentfp;
1836 Sg_scatter_hold *req_schp = &srp->data;
1837
1838 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1839 "sg_finish_rem_req: res_used=%d\n",
1840 (int) srp->res_used));
1841 if (srp->bio)
1842 ret = blk_rq_unmap_user(srp->bio);
1843
1844 if (srp->rq)
1845 blk_mq_free_request(srp->rq);
1846
1847 if (srp->res_used)
1848 sg_unlink_reserve(sfp, srp);
1849 else
1850 sg_remove_scat(sfp, req_schp);
1851
1852 return ret;
1853}
1854
1855static int
1856sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1857{
1858 int sg_bufflen = tablesize * sizeof(struct page *);
1859 gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1860
1861 schp->pages = kzalloc(sg_bufflen, gfp_flags);
1862 if (!schp->pages)
1863 return -ENOMEM;
1864 schp->sglist_len = sg_bufflen;
1865 return tablesize; /* number of scat_gath elements allocated */
1866}
1867
1868static int
1869sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1870{
1871 int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1872 int sg_tablesize = sfp->parentdp->sg_tablesize;
1873 int blk_size = buff_size, order;
1874 gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
1875
1876 if (blk_size < 0)
1877 return -EFAULT;
1878 if (0 == blk_size)
1879 ++blk_size; /* don't know why */
1880 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1881 blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1882 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1883 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1884 buff_size, blk_size));
1885
1886 /* N.B. ret_sz carried into this block ... */
1887 mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1888 if (mx_sc_elems < 0)
1889 return mx_sc_elems; /* most likely -ENOMEM */
1890
1891 num = scatter_elem_sz;
1892 if (unlikely(num != scatter_elem_sz_prev)) {
1893 if (num < PAGE_SIZE) {
1894 scatter_elem_sz = PAGE_SIZE;
1895 scatter_elem_sz_prev = PAGE_SIZE;
1896 } else
1897 scatter_elem_sz_prev = num;
1898 }
1899
1900 order = get_order(num);
1901retry:
1902 ret_sz = 1 << (PAGE_SHIFT + order);
1903
1904 for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1905 k++, rem_sz -= ret_sz) {
1906
1907 num = (rem_sz > scatter_elem_sz_prev) ?
1908 scatter_elem_sz_prev : rem_sz;
1909
1910 schp->pages[k] = alloc_pages(gfp_mask, order);
1911 if (!schp->pages[k])
1912 goto out;
1913
1914 if (num == scatter_elem_sz_prev) {
1915 if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1916 scatter_elem_sz = ret_sz;
1917 scatter_elem_sz_prev = ret_sz;
1918 }
1919 }
1920
1921 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1922 "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1923 k, num, ret_sz));
1924 } /* end of for loop */
1925
1926 schp->page_order = order;
1927 schp->k_use_sg = k;
1928 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1929 "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1930 k, rem_sz));
1931
1932 schp->bufflen = blk_size;
1933 if (rem_sz > 0) /* must have failed */
1934 return -ENOMEM;
1935 return 0;
1936out:
1937 for (i = 0; i < k; i++)
1938 __free_pages(schp->pages[i], order);
1939
1940 if (--order >= 0)
1941 goto retry;
1942
1943 return -ENOMEM;
1944}
1945
1946static void
1947sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1948{
1949 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1950 "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1951 if (schp->pages && schp->sglist_len > 0) {
1952 if (!schp->dio_in_use) {
1953 int k;
1954
1955 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1956 SCSI_LOG_TIMEOUT(5,
1957 sg_printk(KERN_INFO, sfp->parentdp,
1958 "sg_remove_scat: k=%d, pg=0x%p\n",
1959 k, schp->pages[k]));
1960 __free_pages(schp->pages[k], schp->page_order);
1961 }
1962
1963 kfree(schp->pages);
1964 }
1965 }
1966 memset(schp, 0, sizeof (*schp));
1967}
1968
1969static int
1970sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1971{
1972 Sg_scatter_hold *schp = &srp->data;
1973 int k, num;
1974
1975 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1976 "sg_read_oxfer: num_read_xfer=%d\n",
1977 num_read_xfer));
1978 if ((!outp) || (num_read_xfer <= 0))
1979 return 0;
1980
1981 num = 1 << (PAGE_SHIFT + schp->page_order);
1982 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1983 if (num > num_read_xfer) {
1984 if (copy_to_user(outp, page_address(schp->pages[k]),
1985 num_read_xfer))
1986 return -EFAULT;
1987 break;
1988 } else {
1989 if (copy_to_user(outp, page_address(schp->pages[k]),
1990 num))
1991 return -EFAULT;
1992 num_read_xfer -= num;
1993 if (num_read_xfer <= 0)
1994 break;
1995 outp += num;
1996 }
1997 }
1998
1999 return 0;
2000}
2001
2002static void
2003sg_build_reserve(Sg_fd * sfp, int req_size)
2004{
2005 Sg_scatter_hold *schp = &sfp->reserve;
2006
2007 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2008 "sg_build_reserve: req_size=%d\n", req_size));
2009 do {
2010 if (req_size < PAGE_SIZE)
2011 req_size = PAGE_SIZE;
2012 if (0 == sg_build_indirect(schp, sfp, req_size))
2013 return;
2014 else
2015 sg_remove_scat(sfp, schp);
2016 req_size >>= 1; /* divide by 2 */
2017 } while (req_size > (PAGE_SIZE / 2));
2018}
2019
2020static void
2021sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2022{
2023 Sg_scatter_hold *req_schp = &srp->data;
2024 Sg_scatter_hold *rsv_schp = &sfp->reserve;
2025 int k, num, rem;
2026
2027 srp->res_used = 1;
2028 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2029 "sg_link_reserve: size=%d\n", size));
2030 rem = size;
2031
2032 num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
2033 for (k = 0; k < rsv_schp->k_use_sg; k++) {
2034 if (rem <= num) {
2035 req_schp->k_use_sg = k + 1;
2036 req_schp->sglist_len = rsv_schp->sglist_len;
2037 req_schp->pages = rsv_schp->pages;
2038
2039 req_schp->bufflen = size;
2040 req_schp->page_order = rsv_schp->page_order;
2041 break;
2042 } else
2043 rem -= num;
2044 }
2045
2046 if (k >= rsv_schp->k_use_sg)
2047 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2048 "sg_link_reserve: BAD size\n"));
2049}
2050
2051static void
2052sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2053{
2054 Sg_scatter_hold *req_schp = &srp->data;
2055
2056 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2057 "sg_unlink_reserve: req->k_use_sg=%d\n",
2058 (int) req_schp->k_use_sg));
2059 req_schp->k_use_sg = 0;
2060 req_schp->bufflen = 0;
2061 req_schp->pages = NULL;
2062 req_schp->page_order = 0;
2063 req_schp->sglist_len = 0;
2064 srp->res_used = 0;
2065 /* Called without mutex lock to avoid deadlock */
2066 sfp->res_in_use = 0;
2067}
2068
2069static Sg_request *
2070sg_get_rq_mark(Sg_fd * sfp, int pack_id, bool *busy)
2071{
2072 Sg_request *resp;
2073 unsigned long iflags;
2074
2075 *busy = false;
2076 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2077 list_for_each_entry(resp, &sfp->rq_list, entry) {
2078 /* look for requests that are not SG_IO owned */
2079 if ((!resp->sg_io_owned) &&
2080 ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2081 switch (resp->done) {
2082 case 0: /* request active */
2083 *busy = true;
2084 break;
2085 case 1: /* request done; response ready to return */
2086 resp->done = 2; /* guard against other readers */
2087 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2088 return resp;
2089 case 2: /* response already being returned */
2090 break;
2091 }
2092 }
2093 }
2094 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2095 return NULL;
2096}
2097
2098/* always adds to end of list */
2099static Sg_request *
2100sg_add_request(Sg_fd * sfp)
2101{
2102 int k;
2103 unsigned long iflags;
2104 Sg_request *rp = sfp->req_arr;
2105
2106 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2107 if (!list_empty(&sfp->rq_list)) {
2108 if (!sfp->cmd_q)
2109 goto out_unlock;
2110
2111 for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2112 if (!rp->parentfp)
2113 break;
2114 }
2115 if (k >= SG_MAX_QUEUE)
2116 goto out_unlock;
2117 }
2118 memset(rp, 0, sizeof (Sg_request));
2119 rp->parentfp = sfp;
2120 rp->header.duration = jiffies_to_msecs(jiffies);
2121 list_add_tail(&rp->entry, &sfp->rq_list);
2122 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2123 return rp;
2124out_unlock:
2125 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2126 return NULL;
2127}
2128
2129/* Return of 1 for found; 0 for not found */
2130static int
2131sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2132{
2133 unsigned long iflags;
2134 int res = 0;
2135
2136 if (!sfp || !srp || list_empty(&sfp->rq_list))
2137 return res;
2138 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2139 if (!list_empty(&srp->entry)) {
2140 list_del(&srp->entry);
2141 srp->parentfp = NULL;
2142 res = 1;
2143 }
2144 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2145
2146 /*
2147 * If the device is detaching, wakeup any readers in case we just
2148 * removed the last response, which would leave nothing for them to
2149 * return other than -ENODEV.
2150 */
2151 if (unlikely(atomic_read(&sfp->parentdp->detaching)))
2152 wake_up_interruptible_all(&sfp->read_wait);
2153
2154 return res;
2155}
2156
2157static Sg_fd *
2158sg_add_sfp(Sg_device * sdp)
2159{
2160 Sg_fd *sfp;
2161 unsigned long iflags;
2162 int bufflen;
2163
2164 sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2165 if (!sfp)
2166 return ERR_PTR(-ENOMEM);
2167
2168 init_waitqueue_head(&sfp->read_wait);
2169 rwlock_init(&sfp->rq_list_lock);
2170 INIT_LIST_HEAD(&sfp->rq_list);
2171 kref_init(&sfp->f_ref);
2172 mutex_init(&sfp->f_mutex);
2173 sfp->timeout = SG_DEFAULT_TIMEOUT;
2174 sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2175 sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2176 sfp->cmd_q = SG_DEF_COMMAND_Q;
2177 sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2178 sfp->parentdp = sdp;
2179 write_lock_irqsave(&sdp->sfd_lock, iflags);
2180 if (atomic_read(&sdp->detaching)) {
2181 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2182 kfree(sfp);
2183 return ERR_PTR(-ENODEV);
2184 }
2185 list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2186 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2187 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2188 "sg_add_sfp: sfp=0x%p\n", sfp));
2189 if (unlikely(sg_big_buff != def_reserved_size))
2190 sg_big_buff = def_reserved_size;
2191
2192 bufflen = min_t(int, sg_big_buff,
2193 max_sectors_bytes(sdp->device->request_queue));
2194 sg_build_reserve(sfp, bufflen);
2195 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2196 "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2197 sfp->reserve.bufflen,
2198 sfp->reserve.k_use_sg));
2199
2200 kref_get(&sdp->d_ref);
2201 __module_get(THIS_MODULE);
2202 return sfp;
2203}
2204
2205static void
2206sg_remove_sfp_usercontext(struct work_struct *work)
2207{
2208 struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2209 struct sg_device *sdp = sfp->parentdp;
2210 Sg_request *srp;
2211 unsigned long iflags;
2212
2213 /* Cleanup any responses which were never read(). */
2214 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2215 while (!list_empty(&sfp->rq_list)) {
2216 srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2217 sg_finish_rem_req(srp);
2218 list_del(&srp->entry);
2219 srp->parentfp = NULL;
2220 }
2221 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2222
2223 if (sfp->reserve.bufflen > 0) {
2224 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2225 "sg_remove_sfp: bufflen=%d, k_use_sg=%d\n",
2226 (int) sfp->reserve.bufflen,
2227 (int) sfp->reserve.k_use_sg));
2228 sg_remove_scat(sfp, &sfp->reserve);
2229 }
2230
2231 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2232 "sg_remove_sfp: sfp=0x%p\n", sfp));
2233 kfree(sfp);
2234
2235 scsi_device_put(sdp->device);
2236 kref_put(&sdp->d_ref, sg_device_destroy);
2237 module_put(THIS_MODULE);
2238}
2239
2240static void
2241sg_remove_sfp(struct kref *kref)
2242{
2243 struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2244 struct sg_device *sdp = sfp->parentdp;
2245 unsigned long iflags;
2246
2247 write_lock_irqsave(&sdp->sfd_lock, iflags);
2248 list_del(&sfp->sfd_siblings);
2249 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2250
2251 INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2252 schedule_work(&sfp->ew.work);
2253}
2254
2255#ifdef CONFIG_SCSI_PROC_FS
2256static int
2257sg_idr_max_id(int id, void *p, void *data)
2258{
2259 int *k = data;
2260
2261 if (*k < id)
2262 *k = id;
2263
2264 return 0;
2265}
2266
2267static int
2268sg_last_dev(void)
2269{
2270 int k = -1;
2271 unsigned long iflags;
2272
2273 read_lock_irqsave(&sg_index_lock, iflags);
2274 idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2275 read_unlock_irqrestore(&sg_index_lock, iflags);
2276 return k + 1; /* origin 1 */
2277}
2278#endif
2279
2280/* must be called with sg_index_lock held */
2281static Sg_device *sg_lookup_dev(int dev)
2282{
2283 return idr_find(&sg_index_idr, dev);
2284}
2285
2286static Sg_device *
2287sg_get_dev(int dev)
2288{
2289 struct sg_device *sdp;
2290 unsigned long flags;
2291
2292 read_lock_irqsave(&sg_index_lock, flags);
2293 sdp = sg_lookup_dev(dev);
2294 if (!sdp)
2295 sdp = ERR_PTR(-ENXIO);
2296 else if (atomic_read(&sdp->detaching)) {
2297 /* If sdp->detaching, then the refcount may already be 0, in
2298 * which case it would be a bug to do kref_get().
2299 */
2300 sdp = ERR_PTR(-ENODEV);
2301 } else
2302 kref_get(&sdp->d_ref);
2303 read_unlock_irqrestore(&sg_index_lock, flags);
2304
2305 return sdp;
2306}
2307
2308#ifdef CONFIG_SCSI_PROC_FS
2309static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2310
2311static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2312static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2313 size_t count, loff_t *off);
2314static const struct proc_ops adio_proc_ops = {
2315 .proc_open = sg_proc_single_open_adio,
2316 .proc_read = seq_read,
2317 .proc_lseek = seq_lseek,
2318 .proc_write = sg_proc_write_adio,
2319 .proc_release = single_release,
2320};
2321
2322static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2323static ssize_t sg_proc_write_dressz(struct file *filp,
2324 const char __user *buffer, size_t count, loff_t *off);
2325static const struct proc_ops dressz_proc_ops = {
2326 .proc_open = sg_proc_single_open_dressz,
2327 .proc_read = seq_read,
2328 .proc_lseek = seq_lseek,
2329 .proc_write = sg_proc_write_dressz,
2330 .proc_release = single_release,
2331};
2332
2333static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2334static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2335static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2336static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2337static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2338static void dev_seq_stop(struct seq_file *s, void *v);
2339static const struct seq_operations dev_seq_ops = {
2340 .start = dev_seq_start,
2341 .next = dev_seq_next,
2342 .stop = dev_seq_stop,
2343 .show = sg_proc_seq_show_dev,
2344};
2345
2346static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2347static const struct seq_operations devstrs_seq_ops = {
2348 .start = dev_seq_start,
2349 .next = dev_seq_next,
2350 .stop = dev_seq_stop,
2351 .show = sg_proc_seq_show_devstrs,
2352};
2353
2354static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2355static const struct seq_operations debug_seq_ops = {
2356 .start = dev_seq_start,
2357 .next = dev_seq_next,
2358 .stop = dev_seq_stop,
2359 .show = sg_proc_seq_show_debug,
2360};
2361
2362static int
2363sg_proc_init(void)
2364{
2365 struct proc_dir_entry *p;
2366
2367 p = proc_mkdir("scsi/sg", NULL);
2368 if (!p)
2369 return 1;
2370
2371 proc_create("allow_dio", S_IRUGO | S_IWUSR, p, &adio_proc_ops);
2372 proc_create_seq("debug", S_IRUGO, p, &debug_seq_ops);
2373 proc_create("def_reserved_size", S_IRUGO | S_IWUSR, p, &dressz_proc_ops);
2374 proc_create_single("device_hdr", S_IRUGO, p, sg_proc_seq_show_devhdr);
2375 proc_create_seq("devices", S_IRUGO, p, &dev_seq_ops);
2376 proc_create_seq("device_strs", S_IRUGO, p, &devstrs_seq_ops);
2377 proc_create_single("version", S_IRUGO, p, sg_proc_seq_show_version);
2378 return 0;
2379}
2380
2381
2382static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2383{
2384 seq_printf(s, "%d\n", *((int *)s->private));
2385 return 0;
2386}
2387
2388static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2389{
2390 return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2391}
2392
2393static ssize_t
2394sg_proc_write_adio(struct file *filp, const char __user *buffer,
2395 size_t count, loff_t *off)
2396{
2397 int err;
2398 unsigned long num;
2399
2400 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2401 return -EACCES;
2402 err = kstrtoul_from_user(buffer, count, 0, &num);
2403 if (err)
2404 return err;
2405 sg_allow_dio = num ? 1 : 0;
2406 return count;
2407}
2408
2409static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2410{
2411 return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2412}
2413
2414static ssize_t
2415sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2416 size_t count, loff_t *off)
2417{
2418 int err;
2419 unsigned long k = ULONG_MAX;
2420
2421 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2422 return -EACCES;
2423
2424 err = kstrtoul_from_user(buffer, count, 0, &k);
2425 if (err)
2426 return err;
2427 if (k <= 1048576) { /* limit "big buff" to 1 MB */
2428 sg_big_buff = k;
2429 return count;
2430 }
2431 return -ERANGE;
2432}
2433
2434static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2435{
2436 seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2437 sg_version_date);
2438 return 0;
2439}
2440
2441static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2442{
2443 seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2444 return 0;
2445}
2446
2447struct sg_proc_deviter {
2448 loff_t index;
2449 size_t max;
2450};
2451
2452static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2453{
2454 struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2455
2456 s->private = it;
2457 if (! it)
2458 return NULL;
2459
2460 it->index = *pos;
2461 it->max = sg_last_dev();
2462 if (it->index >= it->max)
2463 return NULL;
2464 return it;
2465}
2466
2467static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2468{
2469 struct sg_proc_deviter * it = s->private;
2470
2471 *pos = ++it->index;
2472 return (it->index < it->max) ? it : NULL;
2473}
2474
2475static void dev_seq_stop(struct seq_file *s, void *v)
2476{
2477 kfree(s->private);
2478}
2479
2480static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2481{
2482 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2483 Sg_device *sdp;
2484 struct scsi_device *scsidp;
2485 unsigned long iflags;
2486
2487 read_lock_irqsave(&sg_index_lock, iflags);
2488 sdp = it ? sg_lookup_dev(it->index) : NULL;
2489 if ((NULL == sdp) || (NULL == sdp->device) ||
2490 (atomic_read(&sdp->detaching)))
2491 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2492 else {
2493 scsidp = sdp->device;
2494 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2495 scsidp->host->host_no, scsidp->channel,
2496 scsidp->id, scsidp->lun, (int) scsidp->type,
2497 1,
2498 (int) scsidp->queue_depth,
2499 (int) scsi_device_busy(scsidp),
2500 (int) scsi_device_online(scsidp));
2501 }
2502 read_unlock_irqrestore(&sg_index_lock, iflags);
2503 return 0;
2504}
2505
2506static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2507{
2508 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2509 Sg_device *sdp;
2510 struct scsi_device *scsidp;
2511 unsigned long iflags;
2512
2513 read_lock_irqsave(&sg_index_lock, iflags);
2514 sdp = it ? sg_lookup_dev(it->index) : NULL;
2515 scsidp = sdp ? sdp->device : NULL;
2516 if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2517 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2518 scsidp->vendor, scsidp->model, scsidp->rev);
2519 else
2520 seq_puts(s, "<no active device>\n");
2521 read_unlock_irqrestore(&sg_index_lock, iflags);
2522 return 0;
2523}
2524
2525/* must be called while holding sg_index_lock */
2526static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2527{
2528 int k, new_interface, blen, usg;
2529 Sg_request *srp;
2530 Sg_fd *fp;
2531 const sg_io_hdr_t *hp;
2532 const char * cp;
2533 unsigned int ms;
2534
2535 k = 0;
2536 list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2537 k++;
2538 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2539 seq_printf(s, " FD(%d): timeout=%dms bufflen=%d "
2540 "(res)sgat=%d low_dma=%d\n", k,
2541 jiffies_to_msecs(fp->timeout),
2542 fp->reserve.bufflen,
2543 (int) fp->reserve.k_use_sg, 0);
2544 seq_printf(s, " cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2545 (int) fp->cmd_q, (int) fp->force_packid,
2546 (int) fp->keep_orphan);
2547 list_for_each_entry(srp, &fp->rq_list, entry) {
2548 hp = &srp->header;
2549 new_interface = (hp->interface_id == '\0') ? 0 : 1;
2550 if (srp->res_used) {
2551 if (new_interface &&
2552 (SG_FLAG_MMAP_IO & hp->flags))
2553 cp = " mmap>> ";
2554 else
2555 cp = " rb>> ";
2556 } else {
2557 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2558 cp = " dio>> ";
2559 else
2560 cp = " ";
2561 }
2562 seq_puts(s, cp);
2563 blen = srp->data.bufflen;
2564 usg = srp->data.k_use_sg;
2565 seq_puts(s, srp->done ?
2566 ((1 == srp->done) ? "rcv:" : "fin:")
2567 : "act:");
2568 seq_printf(s, " id=%d blen=%d",
2569 srp->header.pack_id, blen);
2570 if (srp->done)
2571 seq_printf(s, " dur=%d", hp->duration);
2572 else {
2573 ms = jiffies_to_msecs(jiffies);
2574 seq_printf(s, " t_o/elap=%d/%d",
2575 (new_interface ? hp->timeout :
2576 jiffies_to_msecs(fp->timeout)),
2577 (ms > hp->duration ? ms - hp->duration : 0));
2578 }
2579 seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2580 (int) srp->data.cmd_opcode);
2581 }
2582 if (list_empty(&fp->rq_list))
2583 seq_puts(s, " No requests active\n");
2584 read_unlock(&fp->rq_list_lock);
2585 }
2586}
2587
2588static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2589{
2590 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2591 Sg_device *sdp;
2592 unsigned long iflags;
2593
2594 if (it && (0 == it->index))
2595 seq_printf(s, "max_active_device=%d def_reserved_size=%d\n",
2596 (int)it->max, sg_big_buff);
2597
2598 read_lock_irqsave(&sg_index_lock, iflags);
2599 sdp = it ? sg_lookup_dev(it->index) : NULL;
2600 if (NULL == sdp)
2601 goto skip;
2602 read_lock(&sdp->sfd_lock);
2603 if (!list_empty(&sdp->sfds)) {
2604 seq_printf(s, " >>> device=%s ", sdp->name);
2605 if (atomic_read(&sdp->detaching))
2606 seq_puts(s, "detaching pending close ");
2607 else if (sdp->device) {
2608 struct scsi_device *scsidp = sdp->device;
2609
2610 seq_printf(s, "%d:%d:%d:%llu em=%d",
2611 scsidp->host->host_no,
2612 scsidp->channel, scsidp->id,
2613 scsidp->lun,
2614 scsidp->host->hostt->emulated);
2615 }
2616 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2617 sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2618 sg_proc_debug_helper(s, sdp);
2619 }
2620 read_unlock(&sdp->sfd_lock);
2621skip:
2622 read_unlock_irqrestore(&sg_index_lock, iflags);
2623 return 0;
2624}
2625
2626#endif /* CONFIG_SCSI_PROC_FS */
2627
2628module_init(init_sg);
2629module_exit(exit_sg);
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/slab.h>
35#include <linux/fcntl.h>
36#include <linux/init.h>
37#include <linux/poll.h>
38#include <linux/moduleparam.h>
39#include <linux/cdev.h>
40#include <linux/idr.h>
41#include <linux/seq_file.h>
42#include <linux/blkdev.h>
43#include <linux/delay.h>
44#include <linux/blktrace_api.h>
45#include <linux/mutex.h>
46#include <linux/atomic.h>
47#include <linux/ratelimit.h>
48#include <linux/uio.h>
49#include <linux/cred.h> /* for sg_check_file_access() */
50
51#include "scsi.h"
52#include <scsi/scsi_dbg.h>
53#include <scsi/scsi_host.h>
54#include <scsi/scsi_driver.h>
55#include <scsi/scsi_ioctl.h>
56#include <scsi/sg.h>
57
58#include "scsi_logging.h"
59
60#ifdef CONFIG_SCSI_PROC_FS
61#include <linux/proc_fs.h>
62static char *sg_version_date = "20140603";
63
64static int sg_proc_init(void);
65#endif
66
67#define SG_ALLOW_DIO_DEF 0
68
69#define SG_MAX_DEVS 32768
70
71/* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
72 * of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater
73 * than 16 bytes are "variable length" whose length is a multiple of 4
74 */
75#define SG_MAX_CDB_SIZE 252
76
77#define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
78
79int sg_big_buff = SG_DEF_RESERVED_SIZE;
80/* N.B. This variable is readable and writeable via
81 /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
82 of this size (or less if there is not enough memory) will be reserved
83 for use by this file descriptor. [Deprecated usage: this variable is also
84 readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
85 the kernel (i.e. it is not a module).] */
86static int def_reserved_size = -1; /* picks up init parameter */
87static int sg_allow_dio = SG_ALLOW_DIO_DEF;
88
89static int scatter_elem_sz = SG_SCATTER_SZ;
90static int scatter_elem_sz_prev = SG_SCATTER_SZ;
91
92#define SG_SECTOR_SZ 512
93
94static int sg_add_device(struct device *, struct class_interface *);
95static void sg_remove_device(struct device *, struct class_interface *);
96
97static DEFINE_IDR(sg_index_idr);
98static DEFINE_RWLOCK(sg_index_lock); /* Also used to lock
99 file descriptor list for device */
100
101static struct class_interface sg_interface = {
102 .add_dev = sg_add_device,
103 .remove_dev = sg_remove_device,
104};
105
106typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
107 unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
108 unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
109 unsigned bufflen; /* Size of (aggregate) data buffer */
110 struct page **pages;
111 int page_order;
112 char dio_in_use; /* 0->indirect IO (or mmap), 1->dio */
113 unsigned char cmd_opcode; /* first byte of command */
114} Sg_scatter_hold;
115
116struct sg_device; /* forward declarations */
117struct sg_fd;
118
119typedef struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */
120 struct list_head entry; /* list entry */
121 struct sg_fd *parentfp; /* NULL -> not in use */
122 Sg_scatter_hold data; /* hold buffer, perhaps scatter list */
123 sg_io_hdr_t header; /* scsi command+info, see <scsi/sg.h> */
124 unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
125 char res_used; /* 1 -> using reserve buffer, 0 -> not ... */
126 char orphan; /* 1 -> drop on sight, 0 -> normal */
127 char sg_io_owned; /* 1 -> packet belongs to SG_IO */
128 /* done protected by rq_list_lock */
129 char done; /* 0->before bh, 1->before read, 2->read */
130 struct request *rq;
131 struct bio *bio;
132 struct execute_work ew;
133} Sg_request;
134
135typedef struct sg_fd { /* holds the state of a file descriptor */
136 struct list_head sfd_siblings; /* protected by device's sfd_lock */
137 struct sg_device *parentdp; /* owning device */
138 wait_queue_head_t read_wait; /* queue read until command done */
139 rwlock_t rq_list_lock; /* protect access to list in req_arr */
140 struct mutex f_mutex; /* protect against changes in this fd */
141 int timeout; /* defaults to SG_DEFAULT_TIMEOUT */
142 int timeout_user; /* defaults to SG_DEFAULT_TIMEOUT_USER */
143 Sg_scatter_hold reserve; /* buffer held for this file descriptor */
144 struct list_head rq_list; /* head of request list */
145 struct fasync_struct *async_qp; /* used by asynchronous notification */
146 Sg_request req_arr[SG_MAX_QUEUE]; /* used as singly-linked list */
147 char force_packid; /* 1 -> pack_id input to read(), 0 -> ignored */
148 char cmd_q; /* 1 -> allow command queuing, 0 -> don't */
149 unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */
150 char keep_orphan; /* 0 -> drop orphan (def), 1 -> keep for read() */
151 char mmap_called; /* 0 -> mmap() never called on this fd */
152 char res_in_use; /* 1 -> 'reserve' array in use */
153 struct kref f_ref;
154 struct execute_work ew;
155} Sg_fd;
156
157typedef struct sg_device { /* holds the state of each scsi generic device */
158 struct scsi_device *device;
159 wait_queue_head_t open_wait; /* queue open() when O_EXCL present */
160 struct mutex open_rel_lock; /* held when in open() or release() */
161 int sg_tablesize; /* adapter's max scatter-gather table size */
162 u32 index; /* device index number */
163 struct list_head sfds;
164 rwlock_t sfd_lock; /* protect access to sfd list */
165 atomic_t detaching; /* 0->device usable, 1->device detaching */
166 bool exclude; /* 1->open(O_EXCL) succeeded and is active */
167 int open_cnt; /* count of opens (perhaps < num(sfds) ) */
168 char sgdebug; /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
169 struct gendisk *disk;
170 struct cdev * cdev; /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
171 struct kref d_ref;
172} Sg_device;
173
174/* tasklet or soft irq callback */
175static void sg_rq_end_io(struct request *rq, blk_status_t status);
176static int sg_start_req(Sg_request *srp, unsigned char *cmd);
177static int sg_finish_rem_req(Sg_request * srp);
178static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
179static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
180 Sg_request * srp);
181static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
182 const char __user *buf, size_t count, int blocking,
183 int read_only, int sg_io_owned, Sg_request **o_srp);
184static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
185 unsigned char *cmnd, int timeout, int blocking);
186static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
187static void sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp);
188static void sg_build_reserve(Sg_fd * sfp, int req_size);
189static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
190static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
191static Sg_fd *sg_add_sfp(Sg_device * sdp);
192static void sg_remove_sfp(struct kref *);
193static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
194static Sg_request *sg_add_request(Sg_fd * sfp);
195static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
196static Sg_device *sg_get_dev(int dev);
197static void sg_device_destroy(struct kref *kref);
198
199#define SZ_SG_HEADER sizeof(struct sg_header)
200#define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
201#define SZ_SG_IOVEC sizeof(sg_iovec_t)
202#define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
203
204#define sg_printk(prefix, sdp, fmt, a...) \
205 sdev_prefix_printk(prefix, (sdp)->device, \
206 (sdp)->disk->disk_name, fmt, ##a)
207
208/*
209 * The SCSI interfaces that use read() and write() as an asynchronous variant of
210 * ioctl(..., SG_IO, ...) are fundamentally unsafe, since there are lots of ways
211 * to trigger read() and write() calls from various contexts with elevated
212 * privileges. This can lead to kernel memory corruption (e.g. if these
213 * interfaces are called through splice()) and privilege escalation inside
214 * userspace (e.g. if a process with access to such a device passes a file
215 * descriptor to a SUID binary as stdin/stdout/stderr).
216 *
217 * This function provides protection for the legacy API by restricting the
218 * calling context.
219 */
220static int sg_check_file_access(struct file *filp, const char *caller)
221{
222 if (filp->f_cred != current_real_cred()) {
223 pr_err_once("%s: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
224 caller, task_tgid_vnr(current), current->comm);
225 return -EPERM;
226 }
227 if (uaccess_kernel()) {
228 pr_err_once("%s: process %d (%s) called from kernel context, this is not allowed.\n",
229 caller, task_tgid_vnr(current), current->comm);
230 return -EACCES;
231 }
232 return 0;
233}
234
235static int sg_allow_access(struct file *filp, unsigned char *cmd)
236{
237 struct sg_fd *sfp = filp->private_data;
238
239 if (sfp->parentdp->device->type == TYPE_SCANNER)
240 return 0;
241
242 return blk_verify_command(cmd, filp->f_mode);
243}
244
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(&sdp->open_rel_lock);
253 retval = wait_event_interruptible(sdp->open_wait,
254 (atomic_read(&sdp->detaching) ||
255 !sdp->open_cnt));
256 mutex_lock(&sdp->open_rel_lock);
257
258 if (retval) /* -ERESTARTSYS */
259 return retval;
260 if (atomic_read(&sdp->detaching))
261 return -ENODEV;
262 }
263 } else {
264 while (sdp->exclude) {
265 mutex_unlock(&sdp->open_rel_lock);
266 retval = wait_event_interruptible(sdp->open_wait,
267 (atomic_read(&sdp->detaching) ||
268 !sdp->exclude));
269 mutex_lock(&sdp->open_rel_lock);
270
271 if (retval) /* -ERESTARTSYS */
272 return retval;
273 if (atomic_read(&sdp->detaching))
274 return -ENODEV;
275 }
276 }
277
278 return retval;
279}
280
281/* Returns 0 on success, else a negated errno value */
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 Sg_device *sdp;
289 Sg_fd *sfp;
290 int retval;
291
292 nonseekable_open(inode, filp);
293 if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
294 return -EPERM; /* Can't lock it with read only access */
295 sdp = sg_get_dev(dev);
296 if (IS_ERR(sdp))
297 return PTR_ERR(sdp);
298
299 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
300 "sg_open: flags=0x%x\n", flags));
301
302 /* This driver's module count bumped by fops_get in <linux/fs.h> */
303 /* Prevent the device driver from vanishing while we sleep */
304 retval = scsi_device_get(sdp->device);
305 if (retval)
306 goto sg_put;
307
308 retval = scsi_autopm_get_device(sdp->device);
309 if (retval)
310 goto sdp_put;
311
312 /* scsi_block_when_processing_errors() may block so bypass
313 * check if O_NONBLOCK. Permits SCSI commands to be issued
314 * during error recovery. Tread carefully. */
315 if (!((flags & O_NONBLOCK) ||
316 scsi_block_when_processing_errors(sdp->device))) {
317 retval = -ENXIO;
318 /* we are in error recovery for this device */
319 goto error_out;
320 }
321
322 mutex_lock(&sdp->open_rel_lock);
323 if (flags & O_NONBLOCK) {
324 if (flags & O_EXCL) {
325 if (sdp->open_cnt > 0) {
326 retval = -EBUSY;
327 goto error_mutex_locked;
328 }
329 } else {
330 if (sdp->exclude) {
331 retval = -EBUSY;
332 goto error_mutex_locked;
333 }
334 }
335 } else {
336 retval = open_wait(sdp, flags);
337 if (retval) /* -ERESTARTSYS or -ENODEV */
338 goto error_mutex_locked;
339 }
340
341 /* N.B. at this point we are holding the open_rel_lock */
342 if (flags & O_EXCL)
343 sdp->exclude = true;
344
345 if (sdp->open_cnt < 1) { /* no existing opens */
346 sdp->sgdebug = 0;
347 q = sdp->device->request_queue;
348 sdp->sg_tablesize = queue_max_segments(q);
349 }
350 sfp = sg_add_sfp(sdp);
351 if (IS_ERR(sfp)) {
352 retval = PTR_ERR(sfp);
353 goto out_undo;
354 }
355
356 filp->private_data = sfp;
357 sdp->open_cnt++;
358 mutex_unlock(&sdp->open_rel_lock);
359
360 retval = 0;
361sg_put:
362 kref_put(&sdp->d_ref, sg_device_destroy);
363 return retval;
364
365out_undo:
366 if (flags & O_EXCL) {
367 sdp->exclude = false; /* undo if error */
368 wake_up_interruptible(&sdp->open_wait);
369 }
370error_mutex_locked:
371 mutex_unlock(&sdp->open_rel_lock);
372error_out:
373 scsi_autopm_put_device(sdp->device);
374sdp_put:
375 scsi_device_put(sdp->device);
376 goto sg_put;
377}
378
379/* Release resources associated with a successful sg_open()
380 * Returns 0 on success, else a negated errno value */
381static int
382sg_release(struct inode *inode, struct file *filp)
383{
384 Sg_device *sdp;
385 Sg_fd *sfp;
386
387 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
388 return -ENXIO;
389 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
390
391 mutex_lock(&sdp->open_rel_lock);
392 scsi_autopm_put_device(sdp->device);
393 kref_put(&sfp->f_ref, sg_remove_sfp);
394 sdp->open_cnt--;
395
396 /* possibly many open()s waiting on exlude clearing, start many;
397 * only open(O_EXCL)s wait on 0==open_cnt so only start one */
398 if (sdp->exclude) {
399 sdp->exclude = false;
400 wake_up_interruptible_all(&sdp->open_wait);
401 } else if (0 == sdp->open_cnt) {
402 wake_up_interruptible(&sdp->open_wait);
403 }
404 mutex_unlock(&sdp->open_rel_lock);
405 return 0;
406}
407
408static int get_sg_io_pack_id(int *pack_id, void __user *buf, size_t count)
409{
410 struct sg_header __user *old_hdr = buf;
411 int reply_len;
412
413 if (count >= SZ_SG_HEADER) {
414 /* negative reply_len means v3 format, otherwise v1/v2 */
415 if (get_user(reply_len, &old_hdr->reply_len))
416 return -EFAULT;
417
418 if (reply_len >= 0)
419 return get_user(*pack_id, &old_hdr->pack_id);
420
421 if (in_compat_syscall() &&
422 count >= sizeof(struct compat_sg_io_hdr)) {
423 struct compat_sg_io_hdr __user *hp = buf;
424
425 return get_user(*pack_id, &hp->pack_id);
426 }
427
428 if (count >= sizeof(struct sg_io_hdr)) {
429 struct sg_io_hdr __user *hp = buf;
430
431 return get_user(*pack_id, &hp->pack_id);
432 }
433 }
434
435 /* no valid header was passed, so ignore the pack_id */
436 *pack_id = -1;
437 return 0;
438}
439
440static ssize_t
441sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
442{
443 Sg_device *sdp;
444 Sg_fd *sfp;
445 Sg_request *srp;
446 int req_pack_id = -1;
447 sg_io_hdr_t *hp;
448 struct sg_header *old_hdr;
449 int retval;
450
451 /*
452 * This could cause a response to be stranded. Close the associated
453 * file descriptor to free up any resources being held.
454 */
455 retval = sg_check_file_access(filp, __func__);
456 if (retval)
457 return retval;
458
459 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
460 return -ENXIO;
461 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
462 "sg_read: count=%d\n", (int) count));
463
464 if (sfp->force_packid)
465 retval = get_sg_io_pack_id(&req_pack_id, buf, count);
466 if (retval)
467 return retval;
468
469 srp = sg_get_rq_mark(sfp, req_pack_id);
470 if (!srp) { /* now wait on packet to arrive */
471 if (atomic_read(&sdp->detaching))
472 return -ENODEV;
473 if (filp->f_flags & O_NONBLOCK)
474 return -EAGAIN;
475 retval = wait_event_interruptible(sfp->read_wait,
476 (atomic_read(&sdp->detaching) ||
477 (srp = sg_get_rq_mark(sfp, req_pack_id))));
478 if (atomic_read(&sdp->detaching))
479 return -ENODEV;
480 if (retval)
481 /* -ERESTARTSYS as signal hit process */
482 return retval;
483 }
484 if (srp->header.interface_id != '\0')
485 return sg_new_read(sfp, buf, count, srp);
486
487 hp = &srp->header;
488 old_hdr = kzalloc(SZ_SG_HEADER, GFP_KERNEL);
489 if (!old_hdr)
490 return -ENOMEM;
491
492 old_hdr->reply_len = (int) hp->timeout;
493 old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
494 old_hdr->pack_id = hp->pack_id;
495 old_hdr->twelve_byte =
496 ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
497 old_hdr->target_status = hp->masked_status;
498 old_hdr->host_status = hp->host_status;
499 old_hdr->driver_status = hp->driver_status;
500 if ((CHECK_CONDITION & hp->masked_status) ||
501 (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(buf, 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, buf, 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(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(hp->sbp, srp->sense_b, 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(hp, 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, __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(&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(&old_hdr, 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, filp, buf, count,
636 blocking, 0, 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(&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(cmnd, buf, 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, 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(hp, 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(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(cmnd, hp->cmdp, hp->cmd_len)) {
766 sg_remove_request(sfp, srp);
767 return -EFAULT;
768 }
769 if (read_only && sg_allow_access(file, 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, 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(&sdp->detaching)) {
815 if (srp->bio) {
816 scsi_req_free_cmd(scsi_req(srp->rq));
817 blk_put_request(srp->rq);
818 srp->rq = NULL;
819 }
820
821 sg_finish_rem_req(srp);
822 sg_remove_request(sfp, srp);
823 return -ENODEV;
824 }
825
826 hp->duration = jiffies_to_msecs(jiffies);
827 if (hp->interface_id != '\0' && /* v3 (or later) interface */
828 (SG_FLAG_Q_AT_TAIL & hp->flags))
829 at_head = 0;
830 else
831 at_head = 1;
832
833 srp->rq->timeout = timeout;
834 kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
835 blk_execute_rq_nowait(sdp->disk, srp->rq, at_head, sg_rq_end_io);
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(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(o + i, 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(&sdp->detaching))
935 return -ENODEV;
936 if (!scsi_block_when_processing_errors(sdp->device))
937 return -ENXIO;
938 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
939 1, read_only, 1, &srp);
940 if (result < 0)
941 return result;
942 result = wait_event_interruptible(sfp->read_wait,
943 (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
944 if (atomic_read(&sdp->detaching))
945 return -ENODEV;
946 write_lock_irq(&sfp->rq_list_lock);
947 if (srp->done) {
948 srp->done = 2;
949 write_unlock_irq(&sfp->rq_list_lock);
950 result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
951 return (result < 0) ? result : 0;
952 }
953 srp->orphan = 1;
954 write_unlock_irq(&sfp->rq_list_lock);
955 return result; /* -ERESTARTSYS because signal hit process */
956 case SG_SET_TIMEOUT:
957 result = get_user(val, ip);
958 if (result)
959 return result;
960 if (val < 0)
961 return -EIO;
962 if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
963 val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
964 INT_MAX);
965 sfp->timeout_user = val;
966 sfp->timeout = mult_frac(val, HZ, USER_HZ);
967
968 return 0;
969 case SG_GET_TIMEOUT: /* N.B. User receives timeout as return value */
970 /* strange ..., for backward compatibility */
971 return sfp->timeout_user;
972 case SG_SET_FORCE_LOW_DMA:
973 /*
974 * N.B. This ioctl never worked properly, but failed to
975 * return an error value. So returning '0' to keep compability
976 * with legacy applications.
977 */
978 return 0;
979 case SG_GET_LOW_DMA:
980 return put_user(0, ip);
981 case SG_GET_SCSI_ID:
982 {
983 sg_scsi_id_t v;
984
985 if (atomic_read(&sdp->detaching))
986 return -ENODEV;
987 memset(&v, 0, sizeof(v));
988 v.host_no = sdp->device->host->host_no;
989 v.channel = sdp->device->channel;
990 v.scsi_id = sdp->device->id;
991 v.lun = sdp->device->lun;
992 v.scsi_type = sdp->device->type;
993 v.h_cmd_per_lun = sdp->device->host->cmd_per_lun;
994 v.d_queue_depth = sdp->device->queue_depth;
995 if (copy_to_user(p, &v, sizeof(sg_scsi_id_t)))
996 return -EFAULT;
997 return 0;
998 }
999 case SG_SET_FORCE_PACK_ID:
1000 result = get_user(val, ip);
1001 if (result)
1002 return result;
1003 sfp->force_packid = val ? 1 : 0;
1004 return 0;
1005 case SG_GET_PACK_ID:
1006 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1007 list_for_each_entry(srp, &sfp->rq_list, entry) {
1008 if ((1 == srp->done) && (!srp->sg_io_owned)) {
1009 read_unlock_irqrestore(&sfp->rq_list_lock,
1010 iflags);
1011 return put_user(srp->header.pack_id, ip);
1012 }
1013 }
1014 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1015 return put_user(-1, ip);
1016 case SG_GET_NUM_WAITING:
1017 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1018 val = 0;
1019 list_for_each_entry(srp, &sfp->rq_list, entry) {
1020 if ((1 == srp->done) && (!srp->sg_io_owned))
1021 ++val;
1022 }
1023 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1024 return put_user(val, ip);
1025 case SG_GET_SG_TABLESIZE:
1026 return put_user(sdp->sg_tablesize, ip);
1027 case SG_SET_RESERVED_SIZE:
1028 result = get_user(val, ip);
1029 if (result)
1030 return result;
1031 if (val < 0)
1032 return -EINVAL;
1033 val = min_t(int, val,
1034 max_sectors_bytes(sdp->device->request_queue));
1035 mutex_lock(&sfp->f_mutex);
1036 if (val != sfp->reserve.bufflen) {
1037 if (sfp->mmap_called ||
1038 sfp->res_in_use) {
1039 mutex_unlock(&sfp->f_mutex);
1040 return -EBUSY;
1041 }
1042
1043 sg_remove_scat(sfp, &sfp->reserve);
1044 sg_build_reserve(sfp, val);
1045 }
1046 mutex_unlock(&sfp->f_mutex);
1047 return 0;
1048 case SG_GET_RESERVED_SIZE:
1049 val = min_t(int, sfp->reserve.bufflen,
1050 max_sectors_bytes(sdp->device->request_queue));
1051 return put_user(val, ip);
1052 case SG_SET_COMMAND_Q:
1053 result = get_user(val, ip);
1054 if (result)
1055 return result;
1056 sfp->cmd_q = val ? 1 : 0;
1057 return 0;
1058 case SG_GET_COMMAND_Q:
1059 return put_user((int) sfp->cmd_q, ip);
1060 case SG_SET_KEEP_ORPHAN:
1061 result = get_user(val, ip);
1062 if (result)
1063 return result;
1064 sfp->keep_orphan = val;
1065 return 0;
1066 case SG_GET_KEEP_ORPHAN:
1067 return put_user((int) sfp->keep_orphan, ip);
1068 case SG_NEXT_CMD_LEN:
1069 result = get_user(val, ip);
1070 if (result)
1071 return result;
1072 if (val > SG_MAX_CDB_SIZE)
1073 return -ENOMEM;
1074 sfp->next_cmd_len = (val > 0) ? val : 0;
1075 return 0;
1076 case SG_GET_VERSION_NUM:
1077 return put_user(sg_version_num, ip);
1078 case SG_GET_ACCESS_COUNT:
1079 /* faked - we don't have a real access count anymore */
1080 val = (sdp->device ? 1 : 0);
1081 return put_user(val, ip);
1082 case SG_GET_REQUEST_TABLE:
1083 {
1084 sg_req_info_t *rinfo;
1085
1086 rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
1087 GFP_KERNEL);
1088 if (!rinfo)
1089 return -ENOMEM;
1090 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1091 sg_fill_request_table(sfp, rinfo);
1092 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1093 #ifdef CONFIG_COMPAT
1094 if (in_compat_syscall())
1095 result = put_compat_request_table(p, rinfo);
1096 else
1097 #endif
1098 result = copy_to_user(p, rinfo,
1099 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1100 result = result ? -EFAULT : 0;
1101 kfree(rinfo);
1102 return result;
1103 }
1104 case SG_EMULATED_HOST:
1105 if (atomic_read(&sdp->detaching))
1106 return -ENODEV;
1107 return put_user(sdp->device->host->hostt->emulated, ip);
1108 case SCSI_IOCTL_SEND_COMMAND:
1109 if (atomic_read(&sdp->detaching))
1110 return -ENODEV;
1111 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1112 case SG_SET_DEBUG:
1113 result = get_user(val, ip);
1114 if (result)
1115 return result;
1116 sdp->sgdebug = (char) val;
1117 return 0;
1118 case BLKSECTGET:
1119 return put_user(max_sectors_bytes(sdp->device->request_queue),
1120 ip);
1121 case BLKTRACESETUP:
1122 return blk_trace_setup(sdp->device->request_queue,
1123 sdp->disk->disk_name,
1124 MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1125 NULL, p);
1126 case BLKTRACESTART:
1127 return blk_trace_startstop(sdp->device->request_queue, 1);
1128 case BLKTRACESTOP:
1129 return blk_trace_startstop(sdp->device->request_queue, 0);
1130 case BLKTRACETEARDOWN:
1131 return blk_trace_remove(sdp->device->request_queue);
1132 case SCSI_IOCTL_GET_IDLUN:
1133 case SCSI_IOCTL_GET_BUS_NUMBER:
1134 case SCSI_IOCTL_PROBE_HOST:
1135 case SG_GET_TRANSFORM:
1136 case SG_SCSI_RESET:
1137 if (atomic_read(&sdp->detaching))
1138 return -ENODEV;
1139 break;
1140 default:
1141 if (read_only)
1142 return -EPERM; /* don't know so take safe approach */
1143 break;
1144 }
1145
1146 result = scsi_ioctl_block_when_processing_errors(sdp->device,
1147 cmd_in, filp->f_flags & O_NDELAY);
1148 if (result)
1149 return result;
1150
1151 return -ENOIOCTLCMD;
1152}
1153
1154static long
1155sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1156{
1157 void __user *p = (void __user *)arg;
1158 Sg_device *sdp;
1159 Sg_fd *sfp;
1160 int ret;
1161
1162 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1163 return -ENXIO;
1164
1165 ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
1166 if (ret != -ENOIOCTLCMD)
1167 return ret;
1168
1169 return scsi_ioctl(sdp->device, cmd_in, p);
1170}
1171
1172#ifdef CONFIG_COMPAT
1173static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1174{
1175 void __user *p = compat_ptr(arg);
1176 Sg_device *sdp;
1177 Sg_fd *sfp;
1178 int ret;
1179
1180 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1181 return -ENXIO;
1182
1183 ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
1184 if (ret != -ENOIOCTLCMD)
1185 return ret;
1186
1187 return scsi_compat_ioctl(sdp->device, cmd_in, p);
1188}
1189#endif
1190
1191static __poll_t
1192sg_poll(struct file *filp, poll_table * wait)
1193{
1194 __poll_t res = 0;
1195 Sg_device *sdp;
1196 Sg_fd *sfp;
1197 Sg_request *srp;
1198 int count = 0;
1199 unsigned long iflags;
1200
1201 sfp = filp->private_data;
1202 if (!sfp)
1203 return EPOLLERR;
1204 sdp = sfp->parentdp;
1205 if (!sdp)
1206 return EPOLLERR;
1207 poll_wait(filp, &sfp->read_wait, wait);
1208 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1209 list_for_each_entry(srp, &sfp->rq_list, entry) {
1210 /* if any read waiting, flag it */
1211 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1212 res = EPOLLIN | EPOLLRDNORM;
1213 ++count;
1214 }
1215 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1216
1217 if (atomic_read(&sdp->detaching))
1218 res |= EPOLLHUP;
1219 else if (!sfp->cmd_q) {
1220 if (0 == count)
1221 res |= EPOLLOUT | EPOLLWRNORM;
1222 } else if (count < SG_MAX_QUEUE)
1223 res |= EPOLLOUT | EPOLLWRNORM;
1224 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1225 "sg_poll: res=0x%x\n", (__force u32) res));
1226 return res;
1227}
1228
1229static int
1230sg_fasync(int fd, struct file *filp, int mode)
1231{
1232 Sg_device *sdp;
1233 Sg_fd *sfp;
1234
1235 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1236 return -ENXIO;
1237 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1238 "sg_fasync: mode=%d\n", mode));
1239
1240 return fasync_helper(fd, filp, mode, &sfp->async_qp);
1241}
1242
1243static vm_fault_t
1244sg_vma_fault(struct vm_fault *vmf)
1245{
1246 struct vm_area_struct *vma = vmf->vma;
1247 Sg_fd *sfp;
1248 unsigned long offset, len, sa;
1249 Sg_scatter_hold *rsv_schp;
1250 int k, length;
1251
1252 if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1253 return VM_FAULT_SIGBUS;
1254 rsv_schp = &sfp->reserve;
1255 offset = vmf->pgoff << PAGE_SHIFT;
1256 if (offset >= rsv_schp->bufflen)
1257 return VM_FAULT_SIGBUS;
1258 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1259 "sg_vma_fault: offset=%lu, scatg=%d\n",
1260 offset, rsv_schp->k_use_sg));
1261 sa = vma->vm_start;
1262 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1263 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1264 len = vma->vm_end - sa;
1265 len = (len < length) ? len : length;
1266 if (offset < len) {
1267 struct page *page = nth_page(rsv_schp->pages[k],
1268 offset >> PAGE_SHIFT);
1269 get_page(page); /* increment page count */
1270 vmf->page = page;
1271 return 0; /* success */
1272 }
1273 sa += len;
1274 offset -= len;
1275 }
1276
1277 return VM_FAULT_SIGBUS;
1278}
1279
1280static const struct vm_operations_struct sg_mmap_vm_ops = {
1281 .fault = sg_vma_fault,
1282};
1283
1284static int
1285sg_mmap(struct file *filp, struct vm_area_struct *vma)
1286{
1287 Sg_fd *sfp;
1288 unsigned long req_sz, len, sa;
1289 Sg_scatter_hold *rsv_schp;
1290 int k, length;
1291 int ret = 0;
1292
1293 if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1294 return -ENXIO;
1295 req_sz = vma->vm_end - vma->vm_start;
1296 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1297 "sg_mmap starting, vm_start=%p, len=%d\n",
1298 (void *) vma->vm_start, (int) req_sz));
1299 if (vma->vm_pgoff)
1300 return -EINVAL; /* want no offset */
1301 rsv_schp = &sfp->reserve;
1302 mutex_lock(&sfp->f_mutex);
1303 if (req_sz > rsv_schp->bufflen) {
1304 ret = -ENOMEM; /* cannot map more than reserved buffer */
1305 goto out;
1306 }
1307
1308 sa = vma->vm_start;
1309 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1310 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1311 len = vma->vm_end - sa;
1312 len = (len < length) ? len : length;
1313 sa += len;
1314 }
1315
1316 sfp->mmap_called = 1;
1317 vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
1318 vma->vm_private_data = sfp;
1319 vma->vm_ops = &sg_mmap_vm_ops;
1320out:
1321 mutex_unlock(&sfp->f_mutex);
1322 return ret;
1323}
1324
1325static void
1326sg_rq_end_io_usercontext(struct work_struct *work)
1327{
1328 struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1329 struct sg_fd *sfp = srp->parentfp;
1330
1331 sg_finish_rem_req(srp);
1332 sg_remove_request(sfp, srp);
1333 kref_put(&sfp->f_ref, sg_remove_sfp);
1334}
1335
1336/*
1337 * This function is a "bottom half" handler that is called by the mid
1338 * level when a command is completed (or has failed).
1339 */
1340static void
1341sg_rq_end_io(struct request *rq, blk_status_t status)
1342{
1343 struct sg_request *srp = rq->end_io_data;
1344 struct scsi_request *req = scsi_req(rq);
1345 Sg_device *sdp;
1346 Sg_fd *sfp;
1347 unsigned long iflags;
1348 unsigned int ms;
1349 char *sense;
1350 int result, resid, done = 1;
1351
1352 if (WARN_ON(srp->done != 0))
1353 return;
1354
1355 sfp = srp->parentfp;
1356 if (WARN_ON(sfp == NULL))
1357 return;
1358
1359 sdp = sfp->parentdp;
1360 if (unlikely(atomic_read(&sdp->detaching)))
1361 pr_info("%s: device detaching\n", __func__);
1362
1363 sense = req->sense;
1364 result = req->result;
1365 resid = req->resid_len;
1366
1367 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1368 "sg_cmd_done: pack_id=%d, res=0x%x\n",
1369 srp->header.pack_id, result));
1370 srp->header.resid = resid;
1371 ms = jiffies_to_msecs(jiffies);
1372 srp->header.duration = (ms > srp->header.duration) ?
1373 (ms - srp->header.duration) : 0;
1374 if (0 != result) {
1375 struct scsi_sense_hdr sshdr;
1376
1377 srp->header.status = 0xff & result;
1378 srp->header.masked_status = status_byte(result);
1379 srp->header.msg_status = COMMAND_COMPLETE;
1380 srp->header.host_status = host_byte(result);
1381 srp->header.driver_status = driver_byte(result);
1382 if ((sdp->sgdebug > 0) &&
1383 ((CHECK_CONDITION == srp->header.masked_status) ||
1384 (COMMAND_TERMINATED == srp->header.masked_status)))
1385 __scsi_print_sense(sdp->device, __func__, sense,
1386 SCSI_SENSE_BUFFERSIZE);
1387
1388 /* Following if statement is a patch supplied by Eric Youngdale */
1389 if (driver_byte(result) != 0
1390 && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1391 && !scsi_sense_is_deferred(&sshdr)
1392 && sshdr.sense_key == UNIT_ATTENTION
1393 && sdp->device->removable) {
1394 /* Detected possible disc change. Set the bit - this */
1395 /* may be used if there are filesystems using this device */
1396 sdp->device->changed = 1;
1397 }
1398 }
1399
1400 if (req->sense_len)
1401 memcpy(srp->sense_b, req->sense, SCSI_SENSE_BUFFERSIZE);
1402
1403 /* Rely on write phase to clean out srp status values, so no "else" */
1404
1405 /*
1406 * Free the request as soon as it is complete so that its resources
1407 * can be reused without waiting for userspace to read() the
1408 * result. But keep the associated bio (if any) around until
1409 * blk_rq_unmap_user() can be called from user context.
1410 */
1411 srp->rq = NULL;
1412 scsi_req_free_cmd(scsi_req(rq));
1413 blk_put_request(rq);
1414
1415 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1416 if (unlikely(srp->orphan)) {
1417 if (sfp->keep_orphan)
1418 srp->sg_io_owned = 0;
1419 else
1420 done = 0;
1421 }
1422 srp->done = done;
1423 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1424
1425 if (likely(done)) {
1426 /* Now wake up any sg_read() that is waiting for this
1427 * packet.
1428 */
1429 wake_up_interruptible(&sfp->read_wait);
1430 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1431 kref_put(&sfp->f_ref, sg_remove_sfp);
1432 } else {
1433 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1434 schedule_work(&srp->ew.work);
1435 }
1436}
1437
1438static const struct file_operations sg_fops = {
1439 .owner = THIS_MODULE,
1440 .read = sg_read,
1441 .write = sg_write,
1442 .poll = sg_poll,
1443 .unlocked_ioctl = sg_ioctl,
1444#ifdef CONFIG_COMPAT
1445 .compat_ioctl = sg_compat_ioctl,
1446#endif
1447 .open = sg_open,
1448 .mmap = sg_mmap,
1449 .release = sg_release,
1450 .fasync = sg_fasync,
1451 .llseek = no_llseek,
1452};
1453
1454static struct class *sg_sysfs_class;
1455
1456static int sg_sysfs_valid = 0;
1457
1458static Sg_device *
1459sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1460{
1461 struct request_queue *q = scsidp->request_queue;
1462 Sg_device *sdp;
1463 unsigned long iflags;
1464 int error;
1465 u32 k;
1466
1467 sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1468 if (!sdp) {
1469 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1470 "failure\n", __func__);
1471 return ERR_PTR(-ENOMEM);
1472 }
1473
1474 idr_preload(GFP_KERNEL);
1475 write_lock_irqsave(&sg_index_lock, iflags);
1476
1477 error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1478 if (error < 0) {
1479 if (error == -ENOSPC) {
1480 sdev_printk(KERN_WARNING, scsidp,
1481 "Unable to attach sg device type=%d, minor number exceeds %d\n",
1482 scsidp->type, SG_MAX_DEVS - 1);
1483 error = -ENODEV;
1484 } else {
1485 sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1486 "allocation Sg_device failure: %d\n",
1487 __func__, error);
1488 }
1489 goto out_unlock;
1490 }
1491 k = error;
1492
1493 SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1494 "sg_alloc: dev=%d \n", k));
1495 sprintf(disk->disk_name, "sg%d", k);
1496 disk->first_minor = k;
1497 sdp->disk = disk;
1498 sdp->device = scsidp;
1499 mutex_init(&sdp->open_rel_lock);
1500 INIT_LIST_HEAD(&sdp->sfds);
1501 init_waitqueue_head(&sdp->open_wait);
1502 atomic_set(&sdp->detaching, 0);
1503 rwlock_init(&sdp->sfd_lock);
1504 sdp->sg_tablesize = queue_max_segments(q);
1505 sdp->index = k;
1506 kref_init(&sdp->d_ref);
1507 error = 0;
1508
1509out_unlock:
1510 write_unlock_irqrestore(&sg_index_lock, iflags);
1511 idr_preload_end();
1512
1513 if (error) {
1514 kfree(sdp);
1515 return ERR_PTR(error);
1516 }
1517 return sdp;
1518}
1519
1520static int
1521sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
1522{
1523 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1524 struct gendisk *disk;
1525 Sg_device *sdp = NULL;
1526 struct cdev * cdev = NULL;
1527 int error;
1528 unsigned long iflags;
1529
1530 disk = alloc_disk(1);
1531 if (!disk) {
1532 pr_warn("%s: alloc_disk failed\n", __func__);
1533 return -ENOMEM;
1534 }
1535 disk->major = SCSI_GENERIC_MAJOR;
1536
1537 error = -ENOMEM;
1538 cdev = cdev_alloc();
1539 if (!cdev) {
1540 pr_warn("%s: cdev_alloc failed\n", __func__);
1541 goto out;
1542 }
1543 cdev->owner = THIS_MODULE;
1544 cdev->ops = &sg_fops;
1545
1546 sdp = sg_alloc(disk, scsidp);
1547 if (IS_ERR(sdp)) {
1548 pr_warn("%s: sg_alloc failed\n", __func__);
1549 error = PTR_ERR(sdp);
1550 goto out;
1551 }
1552
1553 error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1554 if (error)
1555 goto cdev_add_err;
1556
1557 sdp->cdev = cdev;
1558 if (sg_sysfs_valid) {
1559 struct device *sg_class_member;
1560
1561 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1562 MKDEV(SCSI_GENERIC_MAJOR,
1563 sdp->index),
1564 sdp, "%s", disk->disk_name);
1565 if (IS_ERR(sg_class_member)) {
1566 pr_err("%s: device_create failed\n", __func__);
1567 error = PTR_ERR(sg_class_member);
1568 goto cdev_add_err;
1569 }
1570 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1571 &sg_class_member->kobj, "generic");
1572 if (error)
1573 pr_err("%s: unable to make symlink 'generic' back "
1574 "to sg%d\n", __func__, sdp->index);
1575 } else
1576 pr_warn("%s: sg_sys Invalid\n", __func__);
1577
1578 sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1579 "type %d\n", sdp->index, scsidp->type);
1580
1581 dev_set_drvdata(cl_dev, sdp);
1582
1583 return 0;
1584
1585cdev_add_err:
1586 write_lock_irqsave(&sg_index_lock, iflags);
1587 idr_remove(&sg_index_idr, sdp->index);
1588 write_unlock_irqrestore(&sg_index_lock, iflags);
1589 kfree(sdp);
1590
1591out:
1592 put_disk(disk);
1593 if (cdev)
1594 cdev_del(cdev);
1595 return error;
1596}
1597
1598static void
1599sg_device_destroy(struct kref *kref)
1600{
1601 struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1602 unsigned long flags;
1603
1604 /* CAUTION! Note that the device can still be found via idr_find()
1605 * even though the refcount is 0. Therefore, do idr_remove() BEFORE
1606 * any other cleanup.
1607 */
1608
1609 write_lock_irqsave(&sg_index_lock, flags);
1610 idr_remove(&sg_index_idr, sdp->index);
1611 write_unlock_irqrestore(&sg_index_lock, flags);
1612
1613 SCSI_LOG_TIMEOUT(3,
1614 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1615
1616 put_disk(sdp->disk);
1617 kfree(sdp);
1618}
1619
1620static void
1621sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
1622{
1623 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1624 Sg_device *sdp = dev_get_drvdata(cl_dev);
1625 unsigned long iflags;
1626 Sg_fd *sfp;
1627 int val;
1628
1629 if (!sdp)
1630 return;
1631 /* want sdp->detaching non-zero as soon as possible */
1632 val = atomic_inc_return(&sdp->detaching);
1633 if (val > 1)
1634 return; /* only want to do following once per device */
1635
1636 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1637 "%s\n", __func__));
1638
1639 read_lock_irqsave(&sdp->sfd_lock, iflags);
1640 list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1641 wake_up_interruptible_all(&sfp->read_wait);
1642 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1643 }
1644 wake_up_interruptible_all(&sdp->open_wait);
1645 read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1646
1647 sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1648 device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1649 cdev_del(sdp->cdev);
1650 sdp->cdev = NULL;
1651
1652 kref_put(&sdp->d_ref, sg_device_destroy);
1653}
1654
1655module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1656module_param_named(def_reserved_size, def_reserved_size, int,
1657 S_IRUGO | S_IWUSR);
1658module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1659
1660MODULE_AUTHOR("Douglas Gilbert");
1661MODULE_DESCRIPTION("SCSI generic (sg) driver");
1662MODULE_LICENSE("GPL");
1663MODULE_VERSION(SG_VERSION_STR);
1664MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1665
1666MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1667 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1668MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1669MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1670
1671static int __init
1672init_sg(void)
1673{
1674 int rc;
1675
1676 if (scatter_elem_sz < PAGE_SIZE) {
1677 scatter_elem_sz = PAGE_SIZE;
1678 scatter_elem_sz_prev = scatter_elem_sz;
1679 }
1680 if (def_reserved_size >= 0)
1681 sg_big_buff = def_reserved_size;
1682 else
1683 def_reserved_size = sg_big_buff;
1684
1685 rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1686 SG_MAX_DEVS, "sg");
1687 if (rc)
1688 return rc;
1689 sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1690 if ( IS_ERR(sg_sysfs_class) ) {
1691 rc = PTR_ERR(sg_sysfs_class);
1692 goto err_out;
1693 }
1694 sg_sysfs_valid = 1;
1695 rc = scsi_register_interface(&sg_interface);
1696 if (0 == rc) {
1697#ifdef CONFIG_SCSI_PROC_FS
1698 sg_proc_init();
1699#endif /* CONFIG_SCSI_PROC_FS */
1700 return 0;
1701 }
1702 class_destroy(sg_sysfs_class);
1703err_out:
1704 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1705 return rc;
1706}
1707
1708static void __exit
1709exit_sg(void)
1710{
1711#ifdef CONFIG_SCSI_PROC_FS
1712 remove_proc_subtree("scsi/sg", NULL);
1713#endif /* CONFIG_SCSI_PROC_FS */
1714 scsi_unregister_interface(&sg_interface);
1715 class_destroy(sg_sysfs_class);
1716 sg_sysfs_valid = 0;
1717 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1718 SG_MAX_DEVS);
1719 idr_destroy(&sg_index_idr);
1720}
1721
1722static int
1723sg_start_req(Sg_request *srp, unsigned char *cmd)
1724{
1725 int res;
1726 struct request *rq;
1727 struct scsi_request *req;
1728 Sg_fd *sfp = srp->parentfp;
1729 sg_io_hdr_t *hp = &srp->header;
1730 int dxfer_len = (int) hp->dxfer_len;
1731 int dxfer_dir = hp->dxfer_direction;
1732 unsigned int iov_count = hp->iovec_count;
1733 Sg_scatter_hold *req_schp = &srp->data;
1734 Sg_scatter_hold *rsv_schp = &sfp->reserve;
1735 struct request_queue *q = sfp->parentdp->device->request_queue;
1736 struct rq_map_data *md, map_data;
1737 int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1738 unsigned char *long_cmdp = NULL;
1739
1740 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1741 "sg_start_req: dxfer_len=%d\n",
1742 dxfer_len));
1743
1744 if (hp->cmd_len > BLK_MAX_CDB) {
1745 long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
1746 if (!long_cmdp)
1747 return -ENOMEM;
1748 }
1749
1750 /*
1751 * NOTE
1752 *
1753 * With scsi-mq enabled, there are a fixed number of preallocated
1754 * requests equal in number to shost->can_queue. If all of the
1755 * preallocated requests are already in use, then blk_get_request()
1756 * will sleep until an active command completes, freeing up a request.
1757 * Although waiting in an asynchronous interface is less than ideal, we
1758 * do not want to use BLK_MQ_REQ_NOWAIT here because userspace might
1759 * not expect an EWOULDBLOCK from this condition.
1760 */
1761 rq = blk_get_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
1762 REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
1763 if (IS_ERR(rq)) {
1764 kfree(long_cmdp);
1765 return PTR_ERR(rq);
1766 }
1767 req = scsi_req(rq);
1768
1769 if (hp->cmd_len > BLK_MAX_CDB)
1770 req->cmd = long_cmdp;
1771 memcpy(req->cmd, cmd, hp->cmd_len);
1772 req->cmd_len = hp->cmd_len;
1773
1774 srp->rq = rq;
1775 rq->end_io_data = srp;
1776 req->retries = 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, (unsigned long)hp->dxferp, 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, 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(&sfp->f_mutex);
1799 return res;
1800 } else {
1801 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1802 if (res) {
1803 mutex_unlock(&sfp->f_mutex);
1804 return res;
1805 }
1806 }
1807 mutex_unlock(&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 if (iov_count) {
1821 struct iovec *iov = NULL;
1822 struct iov_iter i;
1823
1824 res = import_iovec(rw, hp->dxferp, iov_count, 0, &iov, &i);
1825 if (res < 0)
1826 return res;
1827
1828 iov_iter_truncate(&i, hp->dxfer_len);
1829 if (!iov_iter_count(&i)) {
1830 kfree(iov);
1831 return -EINVAL;
1832 }
1833
1834 res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
1835 kfree(iov);
1836 } else
1837 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1838 hp->dxfer_len, GFP_ATOMIC);
1839
1840 if (!res) {
1841 srp->bio = rq->bio;
1842
1843 if (!md) {
1844 req_schp->dio_in_use = 1;
1845 hp->info |= SG_INFO_DIRECT_IO;
1846 }
1847 }
1848 return res;
1849}
1850
1851static int
1852sg_finish_rem_req(Sg_request *srp)
1853{
1854 int ret = 0;
1855
1856 Sg_fd *sfp = srp->parentfp;
1857 Sg_scatter_hold *req_schp = &srp->data;
1858
1859 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1860 "sg_finish_rem_req: res_used=%d\n",
1861 (int) srp->res_used));
1862 if (srp->bio)
1863 ret = blk_rq_unmap_user(srp->bio);
1864
1865 if (srp->rq) {
1866 scsi_req_free_cmd(scsi_req(srp->rq));
1867 blk_put_request(srp->rq);
1868 }
1869
1870 if (srp->res_used)
1871 sg_unlink_reserve(sfp, srp);
1872 else
1873 sg_remove_scat(sfp, req_schp);
1874
1875 return ret;
1876}
1877
1878static int
1879sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1880{
1881 int sg_bufflen = tablesize * sizeof(struct page *);
1882 gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1883
1884 schp->pages = kzalloc(sg_bufflen, gfp_flags);
1885 if (!schp->pages)
1886 return -ENOMEM;
1887 schp->sglist_len = sg_bufflen;
1888 return tablesize; /* number of scat_gath elements allocated */
1889}
1890
1891static int
1892sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1893{
1894 int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1895 int sg_tablesize = sfp->parentdp->sg_tablesize;
1896 int blk_size = buff_size, order;
1897 gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
1898
1899 if (blk_size < 0)
1900 return -EFAULT;
1901 if (0 == blk_size)
1902 ++blk_size; /* don't know why */
1903 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1904 blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1905 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1906 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1907 buff_size, blk_size));
1908
1909 /* N.B. ret_sz carried into this block ... */
1910 mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1911 if (mx_sc_elems < 0)
1912 return mx_sc_elems; /* most likely -ENOMEM */
1913
1914 num = scatter_elem_sz;
1915 if (unlikely(num != scatter_elem_sz_prev)) {
1916 if (num < PAGE_SIZE) {
1917 scatter_elem_sz = PAGE_SIZE;
1918 scatter_elem_sz_prev = PAGE_SIZE;
1919 } else
1920 scatter_elem_sz_prev = num;
1921 }
1922
1923 order = get_order(num);
1924retry:
1925 ret_sz = 1 << (PAGE_SHIFT + order);
1926
1927 for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1928 k++, rem_sz -= ret_sz) {
1929
1930 num = (rem_sz > scatter_elem_sz_prev) ?
1931 scatter_elem_sz_prev : rem_sz;
1932
1933 schp->pages[k] = alloc_pages(gfp_mask, order);
1934 if (!schp->pages[k])
1935 goto out;
1936
1937 if (num == scatter_elem_sz_prev) {
1938 if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1939 scatter_elem_sz = ret_sz;
1940 scatter_elem_sz_prev = ret_sz;
1941 }
1942 }
1943
1944 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1945 "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1946 k, num, ret_sz));
1947 } /* end of for loop */
1948
1949 schp->page_order = order;
1950 schp->k_use_sg = k;
1951 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1952 "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1953 k, rem_sz));
1954
1955 schp->bufflen = blk_size;
1956 if (rem_sz > 0) /* must have failed */
1957 return -ENOMEM;
1958 return 0;
1959out:
1960 for (i = 0; i < k; i++)
1961 __free_pages(schp->pages[i], order);
1962
1963 if (--order >= 0)
1964 goto retry;
1965
1966 return -ENOMEM;
1967}
1968
1969static void
1970sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1971{
1972 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1973 "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1974 if (schp->pages && schp->sglist_len > 0) {
1975 if (!schp->dio_in_use) {
1976 int k;
1977
1978 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1979 SCSI_LOG_TIMEOUT(5,
1980 sg_printk(KERN_INFO, sfp->parentdp,
1981 "sg_remove_scat: k=%d, pg=0x%p\n",
1982 k, schp->pages[k]));
1983 __free_pages(schp->pages[k], schp->page_order);
1984 }
1985
1986 kfree(schp->pages);
1987 }
1988 }
1989 memset(schp, 0, sizeof (*schp));
1990}
1991
1992static int
1993sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1994{
1995 Sg_scatter_hold *schp = &srp->data;
1996 int k, num;
1997
1998 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1999 "sg_read_oxfer: num_read_xfer=%d\n",
2000 num_read_xfer));
2001 if ((!outp) || (num_read_xfer <= 0))
2002 return 0;
2003
2004 num = 1 << (PAGE_SHIFT + schp->page_order);
2005 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
2006 if (num > num_read_xfer) {
2007 if (copy_to_user(outp, page_address(schp->pages[k]),
2008 num_read_xfer))
2009 return -EFAULT;
2010 break;
2011 } else {
2012 if (copy_to_user(outp, page_address(schp->pages[k]),
2013 num))
2014 return -EFAULT;
2015 num_read_xfer -= num;
2016 if (num_read_xfer <= 0)
2017 break;
2018 outp += num;
2019 }
2020 }
2021
2022 return 0;
2023}
2024
2025static void
2026sg_build_reserve(Sg_fd * sfp, int req_size)
2027{
2028 Sg_scatter_hold *schp = &sfp->reserve;
2029
2030 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2031 "sg_build_reserve: req_size=%d\n", req_size));
2032 do {
2033 if (req_size < PAGE_SIZE)
2034 req_size = PAGE_SIZE;
2035 if (0 == sg_build_indirect(schp, sfp, req_size))
2036 return;
2037 else
2038 sg_remove_scat(sfp, schp);
2039 req_size >>= 1; /* divide by 2 */
2040 } while (req_size > (PAGE_SIZE / 2));
2041}
2042
2043static void
2044sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2045{
2046 Sg_scatter_hold *req_schp = &srp->data;
2047 Sg_scatter_hold *rsv_schp = &sfp->reserve;
2048 int k, num, rem;
2049
2050 srp->res_used = 1;
2051 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2052 "sg_link_reserve: size=%d\n", size));
2053 rem = size;
2054
2055 num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
2056 for (k = 0; k < rsv_schp->k_use_sg; k++) {
2057 if (rem <= num) {
2058 req_schp->k_use_sg = k + 1;
2059 req_schp->sglist_len = rsv_schp->sglist_len;
2060 req_schp->pages = rsv_schp->pages;
2061
2062 req_schp->bufflen = size;
2063 req_schp->page_order = rsv_schp->page_order;
2064 break;
2065 } else
2066 rem -= num;
2067 }
2068
2069 if (k >= rsv_schp->k_use_sg)
2070 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2071 "sg_link_reserve: BAD size\n"));
2072}
2073
2074static void
2075sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2076{
2077 Sg_scatter_hold *req_schp = &srp->data;
2078
2079 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2080 "sg_unlink_reserve: req->k_use_sg=%d\n",
2081 (int) req_schp->k_use_sg));
2082 req_schp->k_use_sg = 0;
2083 req_schp->bufflen = 0;
2084 req_schp->pages = NULL;
2085 req_schp->page_order = 0;
2086 req_schp->sglist_len = 0;
2087 srp->res_used = 0;
2088 /* Called without mutex lock to avoid deadlock */
2089 sfp->res_in_use = 0;
2090}
2091
2092static Sg_request *
2093sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2094{
2095 Sg_request *resp;
2096 unsigned long iflags;
2097
2098 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2099 list_for_each_entry(resp, &sfp->rq_list, entry) {
2100 /* look for requests that are ready + not SG_IO owned */
2101 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2102 ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2103 resp->done = 2; /* guard against other readers */
2104 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2105 return resp;
2106 }
2107 }
2108 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2109 return NULL;
2110}
2111
2112/* always adds to end of list */
2113static Sg_request *
2114sg_add_request(Sg_fd * sfp)
2115{
2116 int k;
2117 unsigned long iflags;
2118 Sg_request *rp = sfp->req_arr;
2119
2120 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2121 if (!list_empty(&sfp->rq_list)) {
2122 if (!sfp->cmd_q)
2123 goto out_unlock;
2124
2125 for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2126 if (!rp->parentfp)
2127 break;
2128 }
2129 if (k >= SG_MAX_QUEUE)
2130 goto out_unlock;
2131 }
2132 memset(rp, 0, sizeof (Sg_request));
2133 rp->parentfp = sfp;
2134 rp->header.duration = jiffies_to_msecs(jiffies);
2135 list_add_tail(&rp->entry, &sfp->rq_list);
2136 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2137 return rp;
2138out_unlock:
2139 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2140 return NULL;
2141}
2142
2143/* Return of 1 for found; 0 for not found */
2144static int
2145sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2146{
2147 unsigned long iflags;
2148 int res = 0;
2149
2150 if (!sfp || !srp || list_empty(&sfp->rq_list))
2151 return res;
2152 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2153 if (!list_empty(&srp->entry)) {
2154 list_del(&srp->entry);
2155 srp->parentfp = NULL;
2156 res = 1;
2157 }
2158 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2159 return res;
2160}
2161
2162static Sg_fd *
2163sg_add_sfp(Sg_device * sdp)
2164{
2165 Sg_fd *sfp;
2166 unsigned long iflags;
2167 int bufflen;
2168
2169 sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2170 if (!sfp)
2171 return ERR_PTR(-ENOMEM);
2172
2173 init_waitqueue_head(&sfp->read_wait);
2174 rwlock_init(&sfp->rq_list_lock);
2175 INIT_LIST_HEAD(&sfp->rq_list);
2176 kref_init(&sfp->f_ref);
2177 mutex_init(&sfp->f_mutex);
2178 sfp->timeout = SG_DEFAULT_TIMEOUT;
2179 sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2180 sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2181 sfp->cmd_q = SG_DEF_COMMAND_Q;
2182 sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2183 sfp->parentdp = sdp;
2184 write_lock_irqsave(&sdp->sfd_lock, iflags);
2185 if (atomic_read(&sdp->detaching)) {
2186 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2187 kfree(sfp);
2188 return ERR_PTR(-ENODEV);
2189 }
2190 list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2191 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2192 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2193 "sg_add_sfp: sfp=0x%p\n", sfp));
2194 if (unlikely(sg_big_buff != def_reserved_size))
2195 sg_big_buff = def_reserved_size;
2196
2197 bufflen = min_t(int, sg_big_buff,
2198 max_sectors_bytes(sdp->device->request_queue));
2199 sg_build_reserve(sfp, bufflen);
2200 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2201 "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2202 sfp->reserve.bufflen,
2203 sfp->reserve.k_use_sg));
2204
2205 kref_get(&sdp->d_ref);
2206 __module_get(THIS_MODULE);
2207 return sfp;
2208}
2209
2210static void
2211sg_remove_sfp_usercontext(struct work_struct *work)
2212{
2213 struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2214 struct sg_device *sdp = sfp->parentdp;
2215 Sg_request *srp;
2216 unsigned long iflags;
2217
2218 /* Cleanup any responses which were never read(). */
2219 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2220 while (!list_empty(&sfp->rq_list)) {
2221 srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2222 sg_finish_rem_req(srp);
2223 list_del(&srp->entry);
2224 srp->parentfp = NULL;
2225 }
2226 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2227
2228 if (sfp->reserve.bufflen > 0) {
2229 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2230 "sg_remove_sfp: bufflen=%d, k_use_sg=%d\n",
2231 (int) sfp->reserve.bufflen,
2232 (int) sfp->reserve.k_use_sg));
2233 sg_remove_scat(sfp, &sfp->reserve);
2234 }
2235
2236 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2237 "sg_remove_sfp: sfp=0x%p\n", sfp));
2238 kfree(sfp);
2239
2240 scsi_device_put(sdp->device);
2241 kref_put(&sdp->d_ref, sg_device_destroy);
2242 module_put(THIS_MODULE);
2243}
2244
2245static void
2246sg_remove_sfp(struct kref *kref)
2247{
2248 struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2249 struct sg_device *sdp = sfp->parentdp;
2250 unsigned long iflags;
2251
2252 write_lock_irqsave(&sdp->sfd_lock, iflags);
2253 list_del(&sfp->sfd_siblings);
2254 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2255
2256 INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2257 schedule_work(&sfp->ew.work);
2258}
2259
2260#ifdef CONFIG_SCSI_PROC_FS
2261static int
2262sg_idr_max_id(int id, void *p, void *data)
2263{
2264 int *k = data;
2265
2266 if (*k < id)
2267 *k = id;
2268
2269 return 0;
2270}
2271
2272static int
2273sg_last_dev(void)
2274{
2275 int k = -1;
2276 unsigned long iflags;
2277
2278 read_lock_irqsave(&sg_index_lock, iflags);
2279 idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2280 read_unlock_irqrestore(&sg_index_lock, iflags);
2281 return k + 1; /* origin 1 */
2282}
2283#endif
2284
2285/* must be called with sg_index_lock held */
2286static Sg_device *sg_lookup_dev(int dev)
2287{
2288 return idr_find(&sg_index_idr, dev);
2289}
2290
2291static Sg_device *
2292sg_get_dev(int dev)
2293{
2294 struct sg_device *sdp;
2295 unsigned long flags;
2296
2297 read_lock_irqsave(&sg_index_lock, flags);
2298 sdp = sg_lookup_dev(dev);
2299 if (!sdp)
2300 sdp = ERR_PTR(-ENXIO);
2301 else if (atomic_read(&sdp->detaching)) {
2302 /* If sdp->detaching, then the refcount may already be 0, in
2303 * which case it would be a bug to do kref_get().
2304 */
2305 sdp = ERR_PTR(-ENODEV);
2306 } else
2307 kref_get(&sdp->d_ref);
2308 read_unlock_irqrestore(&sg_index_lock, flags);
2309
2310 return sdp;
2311}
2312
2313#ifdef CONFIG_SCSI_PROC_FS
2314static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2315
2316static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2317static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2318 size_t count, loff_t *off);
2319static const struct proc_ops adio_proc_ops = {
2320 .proc_open = sg_proc_single_open_adio,
2321 .proc_read = seq_read,
2322 .proc_lseek = seq_lseek,
2323 .proc_write = sg_proc_write_adio,
2324 .proc_release = single_release,
2325};
2326
2327static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2328static ssize_t sg_proc_write_dressz(struct file *filp,
2329 const char __user *buffer, size_t count, loff_t *off);
2330static const struct proc_ops dressz_proc_ops = {
2331 .proc_open = sg_proc_single_open_dressz,
2332 .proc_read = seq_read,
2333 .proc_lseek = seq_lseek,
2334 .proc_write = sg_proc_write_dressz,
2335 .proc_release = single_release,
2336};
2337
2338static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2339static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2340static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2341static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2342static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2343static void dev_seq_stop(struct seq_file *s, void *v);
2344static const struct seq_operations dev_seq_ops = {
2345 .start = dev_seq_start,
2346 .next = dev_seq_next,
2347 .stop = dev_seq_stop,
2348 .show = sg_proc_seq_show_dev,
2349};
2350
2351static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2352static const struct seq_operations devstrs_seq_ops = {
2353 .start = dev_seq_start,
2354 .next = dev_seq_next,
2355 .stop = dev_seq_stop,
2356 .show = sg_proc_seq_show_devstrs,
2357};
2358
2359static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2360static const struct seq_operations debug_seq_ops = {
2361 .start = dev_seq_start,
2362 .next = dev_seq_next,
2363 .stop = dev_seq_stop,
2364 .show = sg_proc_seq_show_debug,
2365};
2366
2367static int
2368sg_proc_init(void)
2369{
2370 struct proc_dir_entry *p;
2371
2372 p = proc_mkdir("scsi/sg", NULL);
2373 if (!p)
2374 return 1;
2375
2376 proc_create("allow_dio", S_IRUGO | S_IWUSR, p, &adio_proc_ops);
2377 proc_create_seq("debug", S_IRUGO, p, &debug_seq_ops);
2378 proc_create("def_reserved_size", S_IRUGO | S_IWUSR, p, &dressz_proc_ops);
2379 proc_create_single("device_hdr", S_IRUGO, p, sg_proc_seq_show_devhdr);
2380 proc_create_seq("devices", S_IRUGO, p, &dev_seq_ops);
2381 proc_create_seq("device_strs", S_IRUGO, p, &devstrs_seq_ops);
2382 proc_create_single("version", S_IRUGO, p, sg_proc_seq_show_version);
2383 return 0;
2384}
2385
2386
2387static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2388{
2389 seq_printf(s, "%d\n", *((int *)s->private));
2390 return 0;
2391}
2392
2393static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2394{
2395 return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2396}
2397
2398static ssize_t
2399sg_proc_write_adio(struct file *filp, const char __user *buffer,
2400 size_t count, loff_t *off)
2401{
2402 int err;
2403 unsigned long num;
2404
2405 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2406 return -EACCES;
2407 err = kstrtoul_from_user(buffer, count, 0, &num);
2408 if (err)
2409 return err;
2410 sg_allow_dio = num ? 1 : 0;
2411 return count;
2412}
2413
2414static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2415{
2416 return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2417}
2418
2419static ssize_t
2420sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2421 size_t count, loff_t *off)
2422{
2423 int err;
2424 unsigned long k = ULONG_MAX;
2425
2426 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2427 return -EACCES;
2428
2429 err = kstrtoul_from_user(buffer, count, 0, &k);
2430 if (err)
2431 return err;
2432 if (k <= 1048576) { /* limit "big buff" to 1 MB */
2433 sg_big_buff = k;
2434 return count;
2435 }
2436 return -ERANGE;
2437}
2438
2439static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2440{
2441 seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2442 sg_version_date);
2443 return 0;
2444}
2445
2446static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2447{
2448 seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2449 return 0;
2450}
2451
2452struct sg_proc_deviter {
2453 loff_t index;
2454 size_t max;
2455};
2456
2457static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2458{
2459 struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2460
2461 s->private = it;
2462 if (! it)
2463 return NULL;
2464
2465 it->index = *pos;
2466 it->max = sg_last_dev();
2467 if (it->index >= it->max)
2468 return NULL;
2469 return it;
2470}
2471
2472static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2473{
2474 struct sg_proc_deviter * it = s->private;
2475
2476 *pos = ++it->index;
2477 return (it->index < it->max) ? it : NULL;
2478}
2479
2480static void dev_seq_stop(struct seq_file *s, void *v)
2481{
2482 kfree(s->private);
2483}
2484
2485static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2486{
2487 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2488 Sg_device *sdp;
2489 struct scsi_device *scsidp;
2490 unsigned long iflags;
2491
2492 read_lock_irqsave(&sg_index_lock, iflags);
2493 sdp = it ? sg_lookup_dev(it->index) : NULL;
2494 if ((NULL == sdp) || (NULL == sdp->device) ||
2495 (atomic_read(&sdp->detaching)))
2496 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2497 else {
2498 scsidp = sdp->device;
2499 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2500 scsidp->host->host_no, scsidp->channel,
2501 scsidp->id, scsidp->lun, (int) scsidp->type,
2502 1,
2503 (int) scsidp->queue_depth,
2504 (int) scsi_device_busy(scsidp),
2505 (int) scsi_device_online(scsidp));
2506 }
2507 read_unlock_irqrestore(&sg_index_lock, iflags);
2508 return 0;
2509}
2510
2511static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2512{
2513 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2514 Sg_device *sdp;
2515 struct scsi_device *scsidp;
2516 unsigned long iflags;
2517
2518 read_lock_irqsave(&sg_index_lock, iflags);
2519 sdp = it ? sg_lookup_dev(it->index) : NULL;
2520 scsidp = sdp ? sdp->device : NULL;
2521 if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2522 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2523 scsidp->vendor, scsidp->model, scsidp->rev);
2524 else
2525 seq_puts(s, "<no active device>\n");
2526 read_unlock_irqrestore(&sg_index_lock, iflags);
2527 return 0;
2528}
2529
2530/* must be called while holding sg_index_lock */
2531static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2532{
2533 int k, new_interface, blen, usg;
2534 Sg_request *srp;
2535 Sg_fd *fp;
2536 const sg_io_hdr_t *hp;
2537 const char * cp;
2538 unsigned int ms;
2539
2540 k = 0;
2541 list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2542 k++;
2543 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2544 seq_printf(s, " FD(%d): timeout=%dms bufflen=%d "
2545 "(res)sgat=%d low_dma=%d\n", k,
2546 jiffies_to_msecs(fp->timeout),
2547 fp->reserve.bufflen,
2548 (int) fp->reserve.k_use_sg, 0);
2549 seq_printf(s, " cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2550 (int) fp->cmd_q, (int) fp->force_packid,
2551 (int) fp->keep_orphan);
2552 list_for_each_entry(srp, &fp->rq_list, entry) {
2553 hp = &srp->header;
2554 new_interface = (hp->interface_id == '\0') ? 0 : 1;
2555 if (srp->res_used) {
2556 if (new_interface &&
2557 (SG_FLAG_MMAP_IO & hp->flags))
2558 cp = " mmap>> ";
2559 else
2560 cp = " rb>> ";
2561 } else {
2562 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2563 cp = " dio>> ";
2564 else
2565 cp = " ";
2566 }
2567 seq_puts(s, cp);
2568 blen = srp->data.bufflen;
2569 usg = srp->data.k_use_sg;
2570 seq_puts(s, srp->done ?
2571 ((1 == srp->done) ? "rcv:" : "fin:")
2572 : "act:");
2573 seq_printf(s, " id=%d blen=%d",
2574 srp->header.pack_id, blen);
2575 if (srp->done)
2576 seq_printf(s, " dur=%d", hp->duration);
2577 else {
2578 ms = jiffies_to_msecs(jiffies);
2579 seq_printf(s, " t_o/elap=%d/%d",
2580 (new_interface ? hp->timeout :
2581 jiffies_to_msecs(fp->timeout)),
2582 (ms > hp->duration ? ms - hp->duration : 0));
2583 }
2584 seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2585 (int) srp->data.cmd_opcode);
2586 }
2587 if (list_empty(&fp->rq_list))
2588 seq_puts(s, " No requests active\n");
2589 read_unlock(&fp->rq_list_lock);
2590 }
2591}
2592
2593static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2594{
2595 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2596 Sg_device *sdp;
2597 unsigned long iflags;
2598
2599 if (it && (0 == it->index))
2600 seq_printf(s, "max_active_device=%d def_reserved_size=%d\n",
2601 (int)it->max, sg_big_buff);
2602
2603 read_lock_irqsave(&sg_index_lock, iflags);
2604 sdp = it ? sg_lookup_dev(it->index) : NULL;
2605 if (NULL == sdp)
2606 goto skip;
2607 read_lock(&sdp->sfd_lock);
2608 if (!list_empty(&sdp->sfds)) {
2609 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2610 if (atomic_read(&sdp->detaching))
2611 seq_puts(s, "detaching pending close ");
2612 else if (sdp->device) {
2613 struct scsi_device *scsidp = sdp->device;
2614
2615 seq_printf(s, "%d:%d:%d:%llu em=%d",
2616 scsidp->host->host_no,
2617 scsidp->channel, scsidp->id,
2618 scsidp->lun,
2619 scsidp->host->hostt->emulated);
2620 }
2621 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2622 sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2623 sg_proc_debug_helper(s, sdp);
2624 }
2625 read_unlock(&sdp->sfd_lock);
2626skip:
2627 read_unlock_irqrestore(&sg_index_lock, iflags);
2628 return 0;
2629}
2630
2631#endif /* CONFIG_SCSI_PROC_FS */
2632
2633module_init(init_sg);
2634module_exit(exit_sg);