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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/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 (DRIVER_SENSE & hp->driver_status))
502 memcpy(old_hdr->sense_buffer, srp->sense_b,
503 sizeof (old_hdr->sense_buffer));
504 switch (hp->host_status) {
505 /* This setup of 'result' is for backward compatibility and is best
506 ignored by the user who should use target, host + driver status */
507 case DID_OK:
508 case DID_PASSTHROUGH:
509 case DID_SOFT_ERROR:
510 old_hdr->result = 0;
511 break;
512 case DID_NO_CONNECT:
513 case DID_BUS_BUSY:
514 case DID_TIME_OUT:
515 old_hdr->result = EBUSY;
516 break;
517 case DID_BAD_TARGET:
518 case DID_ABORT:
519 case DID_PARITY:
520 case DID_RESET:
521 case DID_BAD_INTR:
522 old_hdr->result = EIO;
523 break;
524 case DID_ERROR:
525 old_hdr->result = (srp->sense_b[0] == 0 &&
526 hp->masked_status == GOOD) ? 0 : EIO;
527 break;
528 default:
529 old_hdr->result = EIO;
530 break;
531 }
532
533 /* Now copy the result back to the user buffer. */
534 if (count >= SZ_SG_HEADER) {
535 if (copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
536 retval = -EFAULT;
537 goto free_old_hdr;
538 }
539 buf += SZ_SG_HEADER;
540 if (count > old_hdr->reply_len)
541 count = old_hdr->reply_len;
542 if (count > SZ_SG_HEADER) {
543 if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
544 retval = -EFAULT;
545 goto free_old_hdr;
546 }
547 }
548 } else
549 count = (old_hdr->result == 0) ? 0 : -EIO;
550 sg_finish_rem_req(srp);
551 sg_remove_request(sfp, srp);
552 retval = count;
553free_old_hdr:
554 kfree(old_hdr);
555 return retval;
556}
557
558static ssize_t
559sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
560{
561 sg_io_hdr_t *hp = &srp->header;
562 int err = 0, err2;
563 int len;
564
565 if (in_compat_syscall()) {
566 if (count < sizeof(struct compat_sg_io_hdr)) {
567 err = -EINVAL;
568 goto err_out;
569 }
570 } else if (count < SZ_SG_IO_HDR) {
571 err = -EINVAL;
572 goto err_out;
573 }
574 hp->sb_len_wr = 0;
575 if ((hp->mx_sb_len > 0) && hp->sbp) {
576 if ((CHECK_CONDITION & hp->masked_status) ||
577 (DRIVER_SENSE & hp->driver_status)) {
578 int sb_len = SCSI_SENSE_BUFFERSIZE;
579 sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
580 len = 8 + (int) srp->sense_b[7]; /* Additional sense length field */
581 len = (len > sb_len) ? sb_len : len;
582 if (copy_to_user(hp->sbp, srp->sense_b, len)) {
583 err = -EFAULT;
584 goto err_out;
585 }
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 scsi_req_free_cmd(scsi_req(srp->rq));
814 blk_put_request(srp->rq);
815 srp->rq = NULL;
816 }
817
818 sg_finish_rem_req(srp);
819 sg_remove_request(sfp, srp);
820 return -ENODEV;
821 }
822
823 hp->duration = jiffies_to_msecs(jiffies);
824 if (hp->interface_id != '\0' && /* v3 (or later) interface */
825 (SG_FLAG_Q_AT_TAIL & hp->flags))
826 at_head = 0;
827 else
828 at_head = 1;
829
830 srp->rq->timeout = timeout;
831 kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
832 blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
833 srp->rq, at_head, sg_rq_end_io);
834 return 0;
835}
836
837static int srp_done(Sg_fd *sfp, Sg_request *srp)
838{
839 unsigned long flags;
840 int ret;
841
842 read_lock_irqsave(&sfp->rq_list_lock, flags);
843 ret = srp->done;
844 read_unlock_irqrestore(&sfp->rq_list_lock, flags);
845 return ret;
846}
847
848static int max_sectors_bytes(struct request_queue *q)
849{
850 unsigned int max_sectors = queue_max_sectors(q);
851
852 max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
853
854 return max_sectors << 9;
855}
856
857static void
858sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
859{
860 Sg_request *srp;
861 int val;
862 unsigned int ms;
863
864 val = 0;
865 list_for_each_entry(srp, &sfp->rq_list, entry) {
866 if (val >= SG_MAX_QUEUE)
867 break;
868 rinfo[val].req_state = srp->done + 1;
869 rinfo[val].problem =
870 srp->header.masked_status &
871 srp->header.host_status &
872 srp->header.driver_status;
873 if (srp->done)
874 rinfo[val].duration =
875 srp->header.duration;
876 else {
877 ms = jiffies_to_msecs(jiffies);
878 rinfo[val].duration =
879 (ms > srp->header.duration) ?
880 (ms - srp->header.duration) : 0;
881 }
882 rinfo[val].orphan = srp->orphan;
883 rinfo[val].sg_io_owned = srp->sg_io_owned;
884 rinfo[val].pack_id = srp->header.pack_id;
885 rinfo[val].usr_ptr = srp->header.usr_ptr;
886 val++;
887 }
888}
889
890#ifdef CONFIG_COMPAT
891struct compat_sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
892 char req_state;
893 char orphan;
894 char sg_io_owned;
895 char problem;
896 int pack_id;
897 compat_uptr_t usr_ptr;
898 unsigned int duration;
899 int unused;
900};
901
902static int put_compat_request_table(struct compat_sg_req_info __user *o,
903 struct sg_req_info *rinfo)
904{
905 int i;
906 for (i = 0; i < SG_MAX_QUEUE; i++) {
907 if (copy_to_user(o + i, rinfo + i, offsetof(sg_req_info_t, usr_ptr)) ||
908 put_user((uintptr_t)rinfo[i].usr_ptr, &o[i].usr_ptr) ||
909 put_user(rinfo[i].duration, &o[i].duration) ||
910 put_user(rinfo[i].unused, &o[i].unused))
911 return -EFAULT;
912 }
913 return 0;
914}
915#endif
916
917static long
918sg_ioctl_common(struct file *filp, Sg_device *sdp, Sg_fd *sfp,
919 unsigned int cmd_in, void __user *p)
920{
921 int __user *ip = p;
922 int result, val, read_only;
923 Sg_request *srp;
924 unsigned long iflags;
925
926 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
927 "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
928 read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
929
930 switch (cmd_in) {
931 case SG_IO:
932 if (atomic_read(&sdp->detaching))
933 return -ENODEV;
934 if (!scsi_block_when_processing_errors(sdp->device))
935 return -ENXIO;
936 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
937 1, read_only, 1, &srp);
938 if (result < 0)
939 return result;
940 result = wait_event_interruptible(sfp->read_wait,
941 (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
942 if (atomic_read(&sdp->detaching))
943 return -ENODEV;
944 write_lock_irq(&sfp->rq_list_lock);
945 if (srp->done) {
946 srp->done = 2;
947 write_unlock_irq(&sfp->rq_list_lock);
948 result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
949 return (result < 0) ? result : 0;
950 }
951 srp->orphan = 1;
952 write_unlock_irq(&sfp->rq_list_lock);
953 return result; /* -ERESTARTSYS because signal hit process */
954 case SG_SET_TIMEOUT:
955 result = get_user(val, ip);
956 if (result)
957 return result;
958 if (val < 0)
959 return -EIO;
960 if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
961 val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
962 INT_MAX);
963 sfp->timeout_user = val;
964 sfp->timeout = mult_frac(val, HZ, USER_HZ);
965
966 return 0;
967 case SG_GET_TIMEOUT: /* N.B. User receives timeout as return value */
968 /* strange ..., for backward compatibility */
969 return sfp->timeout_user;
970 case SG_SET_FORCE_LOW_DMA:
971 /*
972 * N.B. This ioctl never worked properly, but failed to
973 * return an error value. So returning '0' to keep compability
974 * with legacy applications.
975 */
976 return 0;
977 case SG_GET_LOW_DMA:
978 return put_user((int) sdp->device->host->unchecked_isa_dma, ip);
979 case SG_GET_SCSI_ID:
980 {
981 sg_scsi_id_t v;
982
983 if (atomic_read(&sdp->detaching))
984 return -ENODEV;
985 memset(&v, 0, sizeof(v));
986 v.host_no = sdp->device->host->host_no;
987 v.channel = sdp->device->channel;
988 v.scsi_id = sdp->device->id;
989 v.lun = sdp->device->lun;
990 v.scsi_type = sdp->device->type;
991 v.h_cmd_per_lun = sdp->device->host->cmd_per_lun;
992 v.d_queue_depth = sdp->device->queue_depth;
993 if (copy_to_user(p, &v, sizeof(sg_scsi_id_t)))
994 return -EFAULT;
995 return 0;
996 }
997 case SG_SET_FORCE_PACK_ID:
998 result = get_user(val, ip);
999 if (result)
1000 return result;
1001 sfp->force_packid = val ? 1 : 0;
1002 return 0;
1003 case SG_GET_PACK_ID:
1004 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1005 list_for_each_entry(srp, &sfp->rq_list, entry) {
1006 if ((1 == srp->done) && (!srp->sg_io_owned)) {
1007 read_unlock_irqrestore(&sfp->rq_list_lock,
1008 iflags);
1009 return put_user(srp->header.pack_id, ip);
1010 }
1011 }
1012 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1013 return put_user(-1, ip);
1014 case SG_GET_NUM_WAITING:
1015 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1016 val = 0;
1017 list_for_each_entry(srp, &sfp->rq_list, entry) {
1018 if ((1 == srp->done) && (!srp->sg_io_owned))
1019 ++val;
1020 }
1021 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1022 return put_user(val, ip);
1023 case SG_GET_SG_TABLESIZE:
1024 return put_user(sdp->sg_tablesize, ip);
1025 case SG_SET_RESERVED_SIZE:
1026 result = get_user(val, ip);
1027 if (result)
1028 return result;
1029 if (val < 0)
1030 return -EINVAL;
1031 val = min_t(int, val,
1032 max_sectors_bytes(sdp->device->request_queue));
1033 mutex_lock(&sfp->f_mutex);
1034 if (val != sfp->reserve.bufflen) {
1035 if (sfp->mmap_called ||
1036 sfp->res_in_use) {
1037 mutex_unlock(&sfp->f_mutex);
1038 return -EBUSY;
1039 }
1040
1041 sg_remove_scat(sfp, &sfp->reserve);
1042 sg_build_reserve(sfp, val);
1043 }
1044 mutex_unlock(&sfp->f_mutex);
1045 return 0;
1046 case SG_GET_RESERVED_SIZE:
1047 val = min_t(int, sfp->reserve.bufflen,
1048 max_sectors_bytes(sdp->device->request_queue));
1049 return put_user(val, ip);
1050 case SG_SET_COMMAND_Q:
1051 result = get_user(val, ip);
1052 if (result)
1053 return result;
1054 sfp->cmd_q = val ? 1 : 0;
1055 return 0;
1056 case SG_GET_COMMAND_Q:
1057 return put_user((int) sfp->cmd_q, ip);
1058 case SG_SET_KEEP_ORPHAN:
1059 result = get_user(val, ip);
1060 if (result)
1061 return result;
1062 sfp->keep_orphan = val;
1063 return 0;
1064 case SG_GET_KEEP_ORPHAN:
1065 return put_user((int) sfp->keep_orphan, ip);
1066 case SG_NEXT_CMD_LEN:
1067 result = get_user(val, ip);
1068 if (result)
1069 return result;
1070 if (val > SG_MAX_CDB_SIZE)
1071 return -ENOMEM;
1072 sfp->next_cmd_len = (val > 0) ? val : 0;
1073 return 0;
1074 case SG_GET_VERSION_NUM:
1075 return put_user(sg_version_num, ip);
1076 case SG_GET_ACCESS_COUNT:
1077 /* faked - we don't have a real access count anymore */
1078 val = (sdp->device ? 1 : 0);
1079 return put_user(val, ip);
1080 case SG_GET_REQUEST_TABLE:
1081 {
1082 sg_req_info_t *rinfo;
1083
1084 rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
1085 GFP_KERNEL);
1086 if (!rinfo)
1087 return -ENOMEM;
1088 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1089 sg_fill_request_table(sfp, rinfo);
1090 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1091 #ifdef CONFIG_COMPAT
1092 if (in_compat_syscall())
1093 result = put_compat_request_table(p, rinfo);
1094 else
1095 #endif
1096 result = copy_to_user(p, rinfo,
1097 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1098 result = result ? -EFAULT : 0;
1099 kfree(rinfo);
1100 return result;
1101 }
1102 case SG_EMULATED_HOST:
1103 if (atomic_read(&sdp->detaching))
1104 return -ENODEV;
1105 return put_user(sdp->device->host->hostt->emulated, ip);
1106 case SCSI_IOCTL_SEND_COMMAND:
1107 if (atomic_read(&sdp->detaching))
1108 return -ENODEV;
1109 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1110 case SG_SET_DEBUG:
1111 result = get_user(val, ip);
1112 if (result)
1113 return result;
1114 sdp->sgdebug = (char) val;
1115 return 0;
1116 case BLKSECTGET:
1117 return put_user(max_sectors_bytes(sdp->device->request_queue),
1118 ip);
1119 case BLKTRACESETUP:
1120 return blk_trace_setup(sdp->device->request_queue,
1121 sdp->disk->disk_name,
1122 MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1123 NULL, p);
1124 case BLKTRACESTART:
1125 return blk_trace_startstop(sdp->device->request_queue, 1);
1126 case BLKTRACESTOP:
1127 return blk_trace_startstop(sdp->device->request_queue, 0);
1128 case BLKTRACETEARDOWN:
1129 return blk_trace_remove(sdp->device->request_queue);
1130 case SCSI_IOCTL_GET_IDLUN:
1131 case SCSI_IOCTL_GET_BUS_NUMBER:
1132 case SCSI_IOCTL_PROBE_HOST:
1133 case SG_GET_TRANSFORM:
1134 case SG_SCSI_RESET:
1135 if (atomic_read(&sdp->detaching))
1136 return -ENODEV;
1137 break;
1138 default:
1139 if (read_only)
1140 return -EPERM; /* don't know so take safe approach */
1141 break;
1142 }
1143
1144 result = scsi_ioctl_block_when_processing_errors(sdp->device,
1145 cmd_in, filp->f_flags & O_NDELAY);
1146 if (result)
1147 return result;
1148
1149 return -ENOIOCTLCMD;
1150}
1151
1152static long
1153sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1154{
1155 void __user *p = (void __user *)arg;
1156 Sg_device *sdp;
1157 Sg_fd *sfp;
1158 int ret;
1159
1160 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1161 return -ENXIO;
1162
1163 ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
1164 if (ret != -ENOIOCTLCMD)
1165 return ret;
1166
1167 return scsi_ioctl(sdp->device, cmd_in, p);
1168}
1169
1170#ifdef CONFIG_COMPAT
1171static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1172{
1173 void __user *p = compat_ptr(arg);
1174 Sg_device *sdp;
1175 Sg_fd *sfp;
1176 int ret;
1177
1178 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1179 return -ENXIO;
1180
1181 ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
1182 if (ret != -ENOIOCTLCMD)
1183 return ret;
1184
1185 return scsi_compat_ioctl(sdp->device, cmd_in, p);
1186}
1187#endif
1188
1189static __poll_t
1190sg_poll(struct file *filp, poll_table * wait)
1191{
1192 __poll_t res = 0;
1193 Sg_device *sdp;
1194 Sg_fd *sfp;
1195 Sg_request *srp;
1196 int count = 0;
1197 unsigned long iflags;
1198
1199 sfp = filp->private_data;
1200 if (!sfp)
1201 return EPOLLERR;
1202 sdp = sfp->parentdp;
1203 if (!sdp)
1204 return EPOLLERR;
1205 poll_wait(filp, &sfp->read_wait, wait);
1206 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1207 list_for_each_entry(srp, &sfp->rq_list, entry) {
1208 /* if any read waiting, flag it */
1209 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1210 res = EPOLLIN | EPOLLRDNORM;
1211 ++count;
1212 }
1213 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1214
1215 if (atomic_read(&sdp->detaching))
1216 res |= EPOLLHUP;
1217 else if (!sfp->cmd_q) {
1218 if (0 == count)
1219 res |= EPOLLOUT | EPOLLWRNORM;
1220 } else if (count < SG_MAX_QUEUE)
1221 res |= EPOLLOUT | EPOLLWRNORM;
1222 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1223 "sg_poll: res=0x%x\n", (__force u32) res));
1224 return res;
1225}
1226
1227static int
1228sg_fasync(int fd, struct file *filp, int mode)
1229{
1230 Sg_device *sdp;
1231 Sg_fd *sfp;
1232
1233 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1234 return -ENXIO;
1235 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1236 "sg_fasync: mode=%d\n", mode));
1237
1238 return fasync_helper(fd, filp, mode, &sfp->async_qp);
1239}
1240
1241static vm_fault_t
1242sg_vma_fault(struct vm_fault *vmf)
1243{
1244 struct vm_area_struct *vma = vmf->vma;
1245 Sg_fd *sfp;
1246 unsigned long offset, len, sa;
1247 Sg_scatter_hold *rsv_schp;
1248 int k, length;
1249
1250 if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1251 return VM_FAULT_SIGBUS;
1252 rsv_schp = &sfp->reserve;
1253 offset = vmf->pgoff << PAGE_SHIFT;
1254 if (offset >= rsv_schp->bufflen)
1255 return VM_FAULT_SIGBUS;
1256 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1257 "sg_vma_fault: offset=%lu, scatg=%d\n",
1258 offset, rsv_schp->k_use_sg));
1259 sa = vma->vm_start;
1260 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1261 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1262 len = vma->vm_end - sa;
1263 len = (len < length) ? len : length;
1264 if (offset < len) {
1265 struct page *page = nth_page(rsv_schp->pages[k],
1266 offset >> PAGE_SHIFT);
1267 get_page(page); /* increment page count */
1268 vmf->page = page;
1269 return 0; /* success */
1270 }
1271 sa += len;
1272 offset -= len;
1273 }
1274
1275 return VM_FAULT_SIGBUS;
1276}
1277
1278static const struct vm_operations_struct sg_mmap_vm_ops = {
1279 .fault = sg_vma_fault,
1280};
1281
1282static int
1283sg_mmap(struct file *filp, struct vm_area_struct *vma)
1284{
1285 Sg_fd *sfp;
1286 unsigned long req_sz, len, sa;
1287 Sg_scatter_hold *rsv_schp;
1288 int k, length;
1289 int ret = 0;
1290
1291 if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1292 return -ENXIO;
1293 req_sz = vma->vm_end - vma->vm_start;
1294 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1295 "sg_mmap starting, vm_start=%p, len=%d\n",
1296 (void *) vma->vm_start, (int) req_sz));
1297 if (vma->vm_pgoff)
1298 return -EINVAL; /* want no offset */
1299 rsv_schp = &sfp->reserve;
1300 mutex_lock(&sfp->f_mutex);
1301 if (req_sz > rsv_schp->bufflen) {
1302 ret = -ENOMEM; /* cannot map more than reserved buffer */
1303 goto out;
1304 }
1305
1306 sa = vma->vm_start;
1307 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1308 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1309 len = vma->vm_end - sa;
1310 len = (len < length) ? len : length;
1311 sa += len;
1312 }
1313
1314 sfp->mmap_called = 1;
1315 vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
1316 vma->vm_private_data = sfp;
1317 vma->vm_ops = &sg_mmap_vm_ops;
1318out:
1319 mutex_unlock(&sfp->f_mutex);
1320 return ret;
1321}
1322
1323static void
1324sg_rq_end_io_usercontext(struct work_struct *work)
1325{
1326 struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1327 struct sg_fd *sfp = srp->parentfp;
1328
1329 sg_finish_rem_req(srp);
1330 sg_remove_request(sfp, srp);
1331 kref_put(&sfp->f_ref, sg_remove_sfp);
1332}
1333
1334/*
1335 * This function is a "bottom half" handler that is called by the mid
1336 * level when a command is completed (or has failed).
1337 */
1338static void
1339sg_rq_end_io(struct request *rq, blk_status_t status)
1340{
1341 struct sg_request *srp = rq->end_io_data;
1342 struct scsi_request *req = scsi_req(rq);
1343 Sg_device *sdp;
1344 Sg_fd *sfp;
1345 unsigned long iflags;
1346 unsigned int ms;
1347 char *sense;
1348 int result, resid, done = 1;
1349
1350 if (WARN_ON(srp->done != 0))
1351 return;
1352
1353 sfp = srp->parentfp;
1354 if (WARN_ON(sfp == NULL))
1355 return;
1356
1357 sdp = sfp->parentdp;
1358 if (unlikely(atomic_read(&sdp->detaching)))
1359 pr_info("%s: device detaching\n", __func__);
1360
1361 sense = req->sense;
1362 result = req->result;
1363 resid = req->resid_len;
1364
1365 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1366 "sg_cmd_done: pack_id=%d, res=0x%x\n",
1367 srp->header.pack_id, result));
1368 srp->header.resid = resid;
1369 ms = jiffies_to_msecs(jiffies);
1370 srp->header.duration = (ms > srp->header.duration) ?
1371 (ms - srp->header.duration) : 0;
1372 if (0 != result) {
1373 struct scsi_sense_hdr sshdr;
1374
1375 srp->header.status = 0xff & result;
1376 srp->header.masked_status = status_byte(result);
1377 srp->header.msg_status = msg_byte(result);
1378 srp->header.host_status = host_byte(result);
1379 srp->header.driver_status = driver_byte(result);
1380 if ((sdp->sgdebug > 0) &&
1381 ((CHECK_CONDITION == srp->header.masked_status) ||
1382 (COMMAND_TERMINATED == srp->header.masked_status)))
1383 __scsi_print_sense(sdp->device, __func__, sense,
1384 SCSI_SENSE_BUFFERSIZE);
1385
1386 /* Following if statement is a patch supplied by Eric Youngdale */
1387 if (driver_byte(result) != 0
1388 && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1389 && !scsi_sense_is_deferred(&sshdr)
1390 && sshdr.sense_key == UNIT_ATTENTION
1391 && sdp->device->removable) {
1392 /* Detected possible disc change. Set the bit - this */
1393 /* may be used if there are filesystems using this device */
1394 sdp->device->changed = 1;
1395 }
1396 }
1397
1398 if (req->sense_len)
1399 memcpy(srp->sense_b, req->sense, SCSI_SENSE_BUFFERSIZE);
1400
1401 /* Rely on write phase to clean out srp status values, so no "else" */
1402
1403 /*
1404 * Free the request as soon as it is complete so that its resources
1405 * can be reused without waiting for userspace to read() the
1406 * result. But keep the associated bio (if any) around until
1407 * blk_rq_unmap_user() can be called from user context.
1408 */
1409 srp->rq = NULL;
1410 scsi_req_free_cmd(scsi_req(rq));
1411 blk_put_request(rq);
1412
1413 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1414 if (unlikely(srp->orphan)) {
1415 if (sfp->keep_orphan)
1416 srp->sg_io_owned = 0;
1417 else
1418 done = 0;
1419 }
1420 srp->done = done;
1421 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1422
1423 if (likely(done)) {
1424 /* Now wake up any sg_read() that is waiting for this
1425 * packet.
1426 */
1427 wake_up_interruptible(&sfp->read_wait);
1428 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1429 kref_put(&sfp->f_ref, sg_remove_sfp);
1430 } else {
1431 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1432 schedule_work(&srp->ew.work);
1433 }
1434}
1435
1436static const struct file_operations sg_fops = {
1437 .owner = THIS_MODULE,
1438 .read = sg_read,
1439 .write = sg_write,
1440 .poll = sg_poll,
1441 .unlocked_ioctl = sg_ioctl,
1442#ifdef CONFIG_COMPAT
1443 .compat_ioctl = sg_compat_ioctl,
1444#endif
1445 .open = sg_open,
1446 .mmap = sg_mmap,
1447 .release = sg_release,
1448 .fasync = sg_fasync,
1449 .llseek = no_llseek,
1450};
1451
1452static struct class *sg_sysfs_class;
1453
1454static int sg_sysfs_valid = 0;
1455
1456static Sg_device *
1457sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1458{
1459 struct request_queue *q = scsidp->request_queue;
1460 Sg_device *sdp;
1461 unsigned long iflags;
1462 int error;
1463 u32 k;
1464
1465 sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1466 if (!sdp) {
1467 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1468 "failure\n", __func__);
1469 return ERR_PTR(-ENOMEM);
1470 }
1471
1472 idr_preload(GFP_KERNEL);
1473 write_lock_irqsave(&sg_index_lock, iflags);
1474
1475 error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1476 if (error < 0) {
1477 if (error == -ENOSPC) {
1478 sdev_printk(KERN_WARNING, scsidp,
1479 "Unable to attach sg device type=%d, minor number exceeds %d\n",
1480 scsidp->type, SG_MAX_DEVS - 1);
1481 error = -ENODEV;
1482 } else {
1483 sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1484 "allocation Sg_device failure: %d\n",
1485 __func__, error);
1486 }
1487 goto out_unlock;
1488 }
1489 k = error;
1490
1491 SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1492 "sg_alloc: dev=%d \n", k));
1493 sprintf(disk->disk_name, "sg%d", k);
1494 disk->first_minor = k;
1495 sdp->disk = disk;
1496 sdp->device = scsidp;
1497 mutex_init(&sdp->open_rel_lock);
1498 INIT_LIST_HEAD(&sdp->sfds);
1499 init_waitqueue_head(&sdp->open_wait);
1500 atomic_set(&sdp->detaching, 0);
1501 rwlock_init(&sdp->sfd_lock);
1502 sdp->sg_tablesize = queue_max_segments(q);
1503 sdp->index = k;
1504 kref_init(&sdp->d_ref);
1505 error = 0;
1506
1507out_unlock:
1508 write_unlock_irqrestore(&sg_index_lock, iflags);
1509 idr_preload_end();
1510
1511 if (error) {
1512 kfree(sdp);
1513 return ERR_PTR(error);
1514 }
1515 return sdp;
1516}
1517
1518static int
1519sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
1520{
1521 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1522 struct gendisk *disk;
1523 Sg_device *sdp = NULL;
1524 struct cdev * cdev = NULL;
1525 int error;
1526 unsigned long iflags;
1527
1528 disk = alloc_disk(1);
1529 if (!disk) {
1530 pr_warn("%s: alloc_disk failed\n", __func__);
1531 return -ENOMEM;
1532 }
1533 disk->major = SCSI_GENERIC_MAJOR;
1534
1535 error = -ENOMEM;
1536 cdev = cdev_alloc();
1537 if (!cdev) {
1538 pr_warn("%s: cdev_alloc failed\n", __func__);
1539 goto out;
1540 }
1541 cdev->owner = THIS_MODULE;
1542 cdev->ops = &sg_fops;
1543
1544 sdp = sg_alloc(disk, scsidp);
1545 if (IS_ERR(sdp)) {
1546 pr_warn("%s: sg_alloc failed\n", __func__);
1547 error = PTR_ERR(sdp);
1548 goto out;
1549 }
1550
1551 error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1552 if (error)
1553 goto cdev_add_err;
1554
1555 sdp->cdev = cdev;
1556 if (sg_sysfs_valid) {
1557 struct device *sg_class_member;
1558
1559 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1560 MKDEV(SCSI_GENERIC_MAJOR,
1561 sdp->index),
1562 sdp, "%s", disk->disk_name);
1563 if (IS_ERR(sg_class_member)) {
1564 pr_err("%s: device_create failed\n", __func__);
1565 error = PTR_ERR(sg_class_member);
1566 goto cdev_add_err;
1567 }
1568 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1569 &sg_class_member->kobj, "generic");
1570 if (error)
1571 pr_err("%s: unable to make symlink 'generic' back "
1572 "to sg%d\n", __func__, sdp->index);
1573 } else
1574 pr_warn("%s: sg_sys Invalid\n", __func__);
1575
1576 sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1577 "type %d\n", sdp->index, scsidp->type);
1578
1579 dev_set_drvdata(cl_dev, sdp);
1580
1581 return 0;
1582
1583cdev_add_err:
1584 write_lock_irqsave(&sg_index_lock, iflags);
1585 idr_remove(&sg_index_idr, sdp->index);
1586 write_unlock_irqrestore(&sg_index_lock, iflags);
1587 kfree(sdp);
1588
1589out:
1590 put_disk(disk);
1591 if (cdev)
1592 cdev_del(cdev);
1593 return error;
1594}
1595
1596static void
1597sg_device_destroy(struct kref *kref)
1598{
1599 struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1600 unsigned long flags;
1601
1602 /* CAUTION! Note that the device can still be found via idr_find()
1603 * even though the refcount is 0. Therefore, do idr_remove() BEFORE
1604 * any other cleanup.
1605 */
1606
1607 write_lock_irqsave(&sg_index_lock, flags);
1608 idr_remove(&sg_index_idr, sdp->index);
1609 write_unlock_irqrestore(&sg_index_lock, flags);
1610
1611 SCSI_LOG_TIMEOUT(3,
1612 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1613
1614 put_disk(sdp->disk);
1615 kfree(sdp);
1616}
1617
1618static void
1619sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
1620{
1621 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1622 Sg_device *sdp = dev_get_drvdata(cl_dev);
1623 unsigned long iflags;
1624 Sg_fd *sfp;
1625 int val;
1626
1627 if (!sdp)
1628 return;
1629 /* want sdp->detaching non-zero as soon as possible */
1630 val = atomic_inc_return(&sdp->detaching);
1631 if (val > 1)
1632 return; /* only want to do following once per device */
1633
1634 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1635 "%s\n", __func__));
1636
1637 read_lock_irqsave(&sdp->sfd_lock, iflags);
1638 list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1639 wake_up_interruptible_all(&sfp->read_wait);
1640 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1641 }
1642 wake_up_interruptible_all(&sdp->open_wait);
1643 read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1644
1645 sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1646 device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1647 cdev_del(sdp->cdev);
1648 sdp->cdev = NULL;
1649
1650 kref_put(&sdp->d_ref, sg_device_destroy);
1651}
1652
1653module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1654module_param_named(def_reserved_size, def_reserved_size, int,
1655 S_IRUGO | S_IWUSR);
1656module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1657
1658MODULE_AUTHOR("Douglas Gilbert");
1659MODULE_DESCRIPTION("SCSI generic (sg) driver");
1660MODULE_LICENSE("GPL");
1661MODULE_VERSION(SG_VERSION_STR);
1662MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1663
1664MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1665 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1666MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1667MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1668
1669static int __init
1670init_sg(void)
1671{
1672 int rc;
1673
1674 if (scatter_elem_sz < PAGE_SIZE) {
1675 scatter_elem_sz = PAGE_SIZE;
1676 scatter_elem_sz_prev = scatter_elem_sz;
1677 }
1678 if (def_reserved_size >= 0)
1679 sg_big_buff = def_reserved_size;
1680 else
1681 def_reserved_size = sg_big_buff;
1682
1683 rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1684 SG_MAX_DEVS, "sg");
1685 if (rc)
1686 return rc;
1687 sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1688 if ( IS_ERR(sg_sysfs_class) ) {
1689 rc = PTR_ERR(sg_sysfs_class);
1690 goto err_out;
1691 }
1692 sg_sysfs_valid = 1;
1693 rc = scsi_register_interface(&sg_interface);
1694 if (0 == rc) {
1695#ifdef CONFIG_SCSI_PROC_FS
1696 sg_proc_init();
1697#endif /* CONFIG_SCSI_PROC_FS */
1698 return 0;
1699 }
1700 class_destroy(sg_sysfs_class);
1701err_out:
1702 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1703 return rc;
1704}
1705
1706static void __exit
1707exit_sg(void)
1708{
1709#ifdef CONFIG_SCSI_PROC_FS
1710 remove_proc_subtree("scsi/sg", NULL);
1711#endif /* CONFIG_SCSI_PROC_FS */
1712 scsi_unregister_interface(&sg_interface);
1713 class_destroy(sg_sysfs_class);
1714 sg_sysfs_valid = 0;
1715 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1716 SG_MAX_DEVS);
1717 idr_destroy(&sg_index_idr);
1718}
1719
1720static int
1721sg_start_req(Sg_request *srp, unsigned char *cmd)
1722{
1723 int res;
1724 struct request *rq;
1725 struct scsi_request *req;
1726 Sg_fd *sfp = srp->parentfp;
1727 sg_io_hdr_t *hp = &srp->header;
1728 int dxfer_len = (int) hp->dxfer_len;
1729 int dxfer_dir = hp->dxfer_direction;
1730 unsigned int iov_count = hp->iovec_count;
1731 Sg_scatter_hold *req_schp = &srp->data;
1732 Sg_scatter_hold *rsv_schp = &sfp->reserve;
1733 struct request_queue *q = sfp->parentdp->device->request_queue;
1734 struct rq_map_data *md, map_data;
1735 int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1736 unsigned char *long_cmdp = NULL;
1737
1738 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1739 "sg_start_req: dxfer_len=%d\n",
1740 dxfer_len));
1741
1742 if (hp->cmd_len > BLK_MAX_CDB) {
1743 long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
1744 if (!long_cmdp)
1745 return -ENOMEM;
1746 }
1747
1748 /*
1749 * NOTE
1750 *
1751 * With scsi-mq enabled, there are a fixed number of preallocated
1752 * requests equal in number to shost->can_queue. If all of the
1753 * preallocated requests are already in use, then blk_get_request()
1754 * will sleep until an active command completes, freeing up a request.
1755 * Although waiting in an asynchronous interface is less than ideal, we
1756 * do not want to use BLK_MQ_REQ_NOWAIT here because userspace might
1757 * not expect an EWOULDBLOCK from this condition.
1758 */
1759 rq = blk_get_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
1760 REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
1761 if (IS_ERR(rq)) {
1762 kfree(long_cmdp);
1763 return PTR_ERR(rq);
1764 }
1765 req = scsi_req(rq);
1766
1767 if (hp->cmd_len > BLK_MAX_CDB)
1768 req->cmd = long_cmdp;
1769 memcpy(req->cmd, cmd, hp->cmd_len);
1770 req->cmd_len = hp->cmd_len;
1771
1772 srp->rq = rq;
1773 rq->end_io_data = srp;
1774 req->retries = SG_DEFAULT_RETRIES;
1775
1776 if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1777 return 0;
1778
1779 if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1780 dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1781 !sfp->parentdp->device->host->unchecked_isa_dma &&
1782 blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1783 md = NULL;
1784 else
1785 md = &map_data;
1786
1787 if (md) {
1788 mutex_lock(&sfp->f_mutex);
1789 if (dxfer_len <= rsv_schp->bufflen &&
1790 !sfp->res_in_use) {
1791 sfp->res_in_use = 1;
1792 sg_link_reserve(sfp, srp, dxfer_len);
1793 } else if (hp->flags & SG_FLAG_MMAP_IO) {
1794 res = -EBUSY; /* sfp->res_in_use == 1 */
1795 if (dxfer_len > rsv_schp->bufflen)
1796 res = -ENOMEM;
1797 mutex_unlock(&sfp->f_mutex);
1798 return res;
1799 } else {
1800 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1801 if (res) {
1802 mutex_unlock(&sfp->f_mutex);
1803 return res;
1804 }
1805 }
1806 mutex_unlock(&sfp->f_mutex);
1807
1808 md->pages = req_schp->pages;
1809 md->page_order = req_schp->page_order;
1810 md->nr_entries = req_schp->k_use_sg;
1811 md->offset = 0;
1812 md->null_mapped = hp->dxferp ? 0 : 1;
1813 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1814 md->from_user = 1;
1815 else
1816 md->from_user = 0;
1817 }
1818
1819 if (iov_count) {
1820 struct iovec *iov = NULL;
1821 struct iov_iter i;
1822
1823#ifdef CONFIG_COMPAT
1824 if (in_compat_syscall())
1825 res = compat_import_iovec(rw, hp->dxferp, iov_count,
1826 0, &iov, &i);
1827 else
1828#endif
1829 res = import_iovec(rw, hp->dxferp, iov_count,
1830 0, &iov, &i);
1831 if (res < 0)
1832 return res;
1833
1834 iov_iter_truncate(&i, hp->dxfer_len);
1835 if (!iov_iter_count(&i)) {
1836 kfree(iov);
1837 return -EINVAL;
1838 }
1839
1840 res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
1841 kfree(iov);
1842 } else
1843 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1844 hp->dxfer_len, GFP_ATOMIC);
1845
1846 if (!res) {
1847 srp->bio = rq->bio;
1848
1849 if (!md) {
1850 req_schp->dio_in_use = 1;
1851 hp->info |= SG_INFO_DIRECT_IO;
1852 }
1853 }
1854 return res;
1855}
1856
1857static int
1858sg_finish_rem_req(Sg_request *srp)
1859{
1860 int ret = 0;
1861
1862 Sg_fd *sfp = srp->parentfp;
1863 Sg_scatter_hold *req_schp = &srp->data;
1864
1865 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1866 "sg_finish_rem_req: res_used=%d\n",
1867 (int) srp->res_used));
1868 if (srp->bio)
1869 ret = blk_rq_unmap_user(srp->bio);
1870
1871 if (srp->rq) {
1872 scsi_req_free_cmd(scsi_req(srp->rq));
1873 blk_put_request(srp->rq);
1874 }
1875
1876 if (srp->res_used)
1877 sg_unlink_reserve(sfp, srp);
1878 else
1879 sg_remove_scat(sfp, req_schp);
1880
1881 return ret;
1882}
1883
1884static int
1885sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1886{
1887 int sg_bufflen = tablesize * sizeof(struct page *);
1888 gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1889
1890 schp->pages = kzalloc(sg_bufflen, gfp_flags);
1891 if (!schp->pages)
1892 return -ENOMEM;
1893 schp->sglist_len = sg_bufflen;
1894 return tablesize; /* number of scat_gath elements allocated */
1895}
1896
1897static int
1898sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1899{
1900 int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1901 int sg_tablesize = sfp->parentdp->sg_tablesize;
1902 int blk_size = buff_size, order;
1903 gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
1904 struct sg_device *sdp = sfp->parentdp;
1905
1906 if (blk_size < 0)
1907 return -EFAULT;
1908 if (0 == blk_size)
1909 ++blk_size; /* don't know why */
1910 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1911 blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1912 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1913 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1914 buff_size, blk_size));
1915
1916 /* N.B. ret_sz carried into this block ... */
1917 mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1918 if (mx_sc_elems < 0)
1919 return mx_sc_elems; /* most likely -ENOMEM */
1920
1921 num = scatter_elem_sz;
1922 if (unlikely(num != scatter_elem_sz_prev)) {
1923 if (num < PAGE_SIZE) {
1924 scatter_elem_sz = PAGE_SIZE;
1925 scatter_elem_sz_prev = PAGE_SIZE;
1926 } else
1927 scatter_elem_sz_prev = num;
1928 }
1929
1930 if (sdp->device->host->unchecked_isa_dma)
1931 gfp_mask |= GFP_DMA;
1932
1933 order = get_order(num);
1934retry:
1935 ret_sz = 1 << (PAGE_SHIFT + order);
1936
1937 for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1938 k++, rem_sz -= ret_sz) {
1939
1940 num = (rem_sz > scatter_elem_sz_prev) ?
1941 scatter_elem_sz_prev : rem_sz;
1942
1943 schp->pages[k] = alloc_pages(gfp_mask, order);
1944 if (!schp->pages[k])
1945 goto out;
1946
1947 if (num == scatter_elem_sz_prev) {
1948 if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1949 scatter_elem_sz = ret_sz;
1950 scatter_elem_sz_prev = ret_sz;
1951 }
1952 }
1953
1954 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1955 "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1956 k, num, ret_sz));
1957 } /* end of for loop */
1958
1959 schp->page_order = order;
1960 schp->k_use_sg = k;
1961 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1962 "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1963 k, rem_sz));
1964
1965 schp->bufflen = blk_size;
1966 if (rem_sz > 0) /* must have failed */
1967 return -ENOMEM;
1968 return 0;
1969out:
1970 for (i = 0; i < k; i++)
1971 __free_pages(schp->pages[i], order);
1972
1973 if (--order >= 0)
1974 goto retry;
1975
1976 return -ENOMEM;
1977}
1978
1979static void
1980sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1981{
1982 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1983 "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1984 if (schp->pages && schp->sglist_len > 0) {
1985 if (!schp->dio_in_use) {
1986 int k;
1987
1988 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1989 SCSI_LOG_TIMEOUT(5,
1990 sg_printk(KERN_INFO, sfp->parentdp,
1991 "sg_remove_scat: k=%d, pg=0x%p\n",
1992 k, schp->pages[k]));
1993 __free_pages(schp->pages[k], schp->page_order);
1994 }
1995
1996 kfree(schp->pages);
1997 }
1998 }
1999 memset(schp, 0, sizeof (*schp));
2000}
2001
2002static int
2003sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
2004{
2005 Sg_scatter_hold *schp = &srp->data;
2006 int k, num;
2007
2008 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2009 "sg_read_oxfer: num_read_xfer=%d\n",
2010 num_read_xfer));
2011 if ((!outp) || (num_read_xfer <= 0))
2012 return 0;
2013
2014 num = 1 << (PAGE_SHIFT + schp->page_order);
2015 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
2016 if (num > num_read_xfer) {
2017 if (copy_to_user(outp, page_address(schp->pages[k]),
2018 num_read_xfer))
2019 return -EFAULT;
2020 break;
2021 } else {
2022 if (copy_to_user(outp, page_address(schp->pages[k]),
2023 num))
2024 return -EFAULT;
2025 num_read_xfer -= num;
2026 if (num_read_xfer <= 0)
2027 break;
2028 outp += num;
2029 }
2030 }
2031
2032 return 0;
2033}
2034
2035static void
2036sg_build_reserve(Sg_fd * sfp, int req_size)
2037{
2038 Sg_scatter_hold *schp = &sfp->reserve;
2039
2040 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2041 "sg_build_reserve: req_size=%d\n", req_size));
2042 do {
2043 if (req_size < PAGE_SIZE)
2044 req_size = PAGE_SIZE;
2045 if (0 == sg_build_indirect(schp, sfp, req_size))
2046 return;
2047 else
2048 sg_remove_scat(sfp, schp);
2049 req_size >>= 1; /* divide by 2 */
2050 } while (req_size > (PAGE_SIZE / 2));
2051}
2052
2053static void
2054sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2055{
2056 Sg_scatter_hold *req_schp = &srp->data;
2057 Sg_scatter_hold *rsv_schp = &sfp->reserve;
2058 int k, num, rem;
2059
2060 srp->res_used = 1;
2061 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2062 "sg_link_reserve: size=%d\n", size));
2063 rem = size;
2064
2065 num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
2066 for (k = 0; k < rsv_schp->k_use_sg; k++) {
2067 if (rem <= num) {
2068 req_schp->k_use_sg = k + 1;
2069 req_schp->sglist_len = rsv_schp->sglist_len;
2070 req_schp->pages = rsv_schp->pages;
2071
2072 req_schp->bufflen = size;
2073 req_schp->page_order = rsv_schp->page_order;
2074 break;
2075 } else
2076 rem -= num;
2077 }
2078
2079 if (k >= rsv_schp->k_use_sg)
2080 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2081 "sg_link_reserve: BAD size\n"));
2082}
2083
2084static void
2085sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2086{
2087 Sg_scatter_hold *req_schp = &srp->data;
2088
2089 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2090 "sg_unlink_reserve: req->k_use_sg=%d\n",
2091 (int) req_schp->k_use_sg));
2092 req_schp->k_use_sg = 0;
2093 req_schp->bufflen = 0;
2094 req_schp->pages = NULL;
2095 req_schp->page_order = 0;
2096 req_schp->sglist_len = 0;
2097 srp->res_used = 0;
2098 /* Called without mutex lock to avoid deadlock */
2099 sfp->res_in_use = 0;
2100}
2101
2102static Sg_request *
2103sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2104{
2105 Sg_request *resp;
2106 unsigned long iflags;
2107
2108 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2109 list_for_each_entry(resp, &sfp->rq_list, entry) {
2110 /* look for requests that are ready + not SG_IO owned */
2111 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2112 ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2113 resp->done = 2; /* guard against other readers */
2114 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2115 return resp;
2116 }
2117 }
2118 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2119 return NULL;
2120}
2121
2122/* always adds to end of list */
2123static Sg_request *
2124sg_add_request(Sg_fd * sfp)
2125{
2126 int k;
2127 unsigned long iflags;
2128 Sg_request *rp = sfp->req_arr;
2129
2130 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2131 if (!list_empty(&sfp->rq_list)) {
2132 if (!sfp->cmd_q)
2133 goto out_unlock;
2134
2135 for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2136 if (!rp->parentfp)
2137 break;
2138 }
2139 if (k >= SG_MAX_QUEUE)
2140 goto out_unlock;
2141 }
2142 memset(rp, 0, sizeof (Sg_request));
2143 rp->parentfp = sfp;
2144 rp->header.duration = jiffies_to_msecs(jiffies);
2145 list_add_tail(&rp->entry, &sfp->rq_list);
2146 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2147 return rp;
2148out_unlock:
2149 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2150 return NULL;
2151}
2152
2153/* Return of 1 for found; 0 for not found */
2154static int
2155sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2156{
2157 unsigned long iflags;
2158 int res = 0;
2159
2160 if (!sfp || !srp || list_empty(&sfp->rq_list))
2161 return res;
2162 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2163 if (!list_empty(&srp->entry)) {
2164 list_del(&srp->entry);
2165 srp->parentfp = NULL;
2166 res = 1;
2167 }
2168 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2169 return res;
2170}
2171
2172static Sg_fd *
2173sg_add_sfp(Sg_device * sdp)
2174{
2175 Sg_fd *sfp;
2176 unsigned long iflags;
2177 int bufflen;
2178
2179 sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2180 if (!sfp)
2181 return ERR_PTR(-ENOMEM);
2182
2183 init_waitqueue_head(&sfp->read_wait);
2184 rwlock_init(&sfp->rq_list_lock);
2185 INIT_LIST_HEAD(&sfp->rq_list);
2186 kref_init(&sfp->f_ref);
2187 mutex_init(&sfp->f_mutex);
2188 sfp->timeout = SG_DEFAULT_TIMEOUT;
2189 sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2190 sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2191 sfp->cmd_q = SG_DEF_COMMAND_Q;
2192 sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2193 sfp->parentdp = sdp;
2194 write_lock_irqsave(&sdp->sfd_lock, iflags);
2195 if (atomic_read(&sdp->detaching)) {
2196 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2197 kfree(sfp);
2198 return ERR_PTR(-ENODEV);
2199 }
2200 list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2201 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2202 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2203 "sg_add_sfp: sfp=0x%p\n", sfp));
2204 if (unlikely(sg_big_buff != def_reserved_size))
2205 sg_big_buff = def_reserved_size;
2206
2207 bufflen = min_t(int, sg_big_buff,
2208 max_sectors_bytes(sdp->device->request_queue));
2209 sg_build_reserve(sfp, bufflen);
2210 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2211 "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2212 sfp->reserve.bufflen,
2213 sfp->reserve.k_use_sg));
2214
2215 kref_get(&sdp->d_ref);
2216 __module_get(THIS_MODULE);
2217 return sfp;
2218}
2219
2220static void
2221sg_remove_sfp_usercontext(struct work_struct *work)
2222{
2223 struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2224 struct sg_device *sdp = sfp->parentdp;
2225 Sg_request *srp;
2226 unsigned long iflags;
2227
2228 /* Cleanup any responses which were never read(). */
2229 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2230 while (!list_empty(&sfp->rq_list)) {
2231 srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2232 sg_finish_rem_req(srp);
2233 list_del(&srp->entry);
2234 srp->parentfp = NULL;
2235 }
2236 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2237
2238 if (sfp->reserve.bufflen > 0) {
2239 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2240 "sg_remove_sfp: bufflen=%d, k_use_sg=%d\n",
2241 (int) sfp->reserve.bufflen,
2242 (int) sfp->reserve.k_use_sg));
2243 sg_remove_scat(sfp, &sfp->reserve);
2244 }
2245
2246 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2247 "sg_remove_sfp: sfp=0x%p\n", sfp));
2248 kfree(sfp);
2249
2250 scsi_device_put(sdp->device);
2251 kref_put(&sdp->d_ref, sg_device_destroy);
2252 module_put(THIS_MODULE);
2253}
2254
2255static void
2256sg_remove_sfp(struct kref *kref)
2257{
2258 struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2259 struct sg_device *sdp = sfp->parentdp;
2260 unsigned long iflags;
2261
2262 write_lock_irqsave(&sdp->sfd_lock, iflags);
2263 list_del(&sfp->sfd_siblings);
2264 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2265
2266 INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2267 schedule_work(&sfp->ew.work);
2268}
2269
2270#ifdef CONFIG_SCSI_PROC_FS
2271static int
2272sg_idr_max_id(int id, void *p, void *data)
2273{
2274 int *k = data;
2275
2276 if (*k < id)
2277 *k = id;
2278
2279 return 0;
2280}
2281
2282static int
2283sg_last_dev(void)
2284{
2285 int k = -1;
2286 unsigned long iflags;
2287
2288 read_lock_irqsave(&sg_index_lock, iflags);
2289 idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2290 read_unlock_irqrestore(&sg_index_lock, iflags);
2291 return k + 1; /* origin 1 */
2292}
2293#endif
2294
2295/* must be called with sg_index_lock held */
2296static Sg_device *sg_lookup_dev(int dev)
2297{
2298 return idr_find(&sg_index_idr, dev);
2299}
2300
2301static Sg_device *
2302sg_get_dev(int dev)
2303{
2304 struct sg_device *sdp;
2305 unsigned long flags;
2306
2307 read_lock_irqsave(&sg_index_lock, flags);
2308 sdp = sg_lookup_dev(dev);
2309 if (!sdp)
2310 sdp = ERR_PTR(-ENXIO);
2311 else if (atomic_read(&sdp->detaching)) {
2312 /* If sdp->detaching, then the refcount may already be 0, in
2313 * which case it would be a bug to do kref_get().
2314 */
2315 sdp = ERR_PTR(-ENODEV);
2316 } else
2317 kref_get(&sdp->d_ref);
2318 read_unlock_irqrestore(&sg_index_lock, flags);
2319
2320 return sdp;
2321}
2322
2323#ifdef CONFIG_SCSI_PROC_FS
2324static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2325
2326static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2327static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2328 size_t count, loff_t *off);
2329static const struct proc_ops adio_proc_ops = {
2330 .proc_open = sg_proc_single_open_adio,
2331 .proc_read = seq_read,
2332 .proc_lseek = seq_lseek,
2333 .proc_write = sg_proc_write_adio,
2334 .proc_release = single_release,
2335};
2336
2337static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2338static ssize_t sg_proc_write_dressz(struct file *filp,
2339 const char __user *buffer, size_t count, loff_t *off);
2340static const struct proc_ops dressz_proc_ops = {
2341 .proc_open = sg_proc_single_open_dressz,
2342 .proc_read = seq_read,
2343 .proc_lseek = seq_lseek,
2344 .proc_write = sg_proc_write_dressz,
2345 .proc_release = single_release,
2346};
2347
2348static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2349static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2350static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2351static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2352static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2353static void dev_seq_stop(struct seq_file *s, void *v);
2354static const struct seq_operations dev_seq_ops = {
2355 .start = dev_seq_start,
2356 .next = dev_seq_next,
2357 .stop = dev_seq_stop,
2358 .show = sg_proc_seq_show_dev,
2359};
2360
2361static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2362static const struct seq_operations devstrs_seq_ops = {
2363 .start = dev_seq_start,
2364 .next = dev_seq_next,
2365 .stop = dev_seq_stop,
2366 .show = sg_proc_seq_show_devstrs,
2367};
2368
2369static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2370static const struct seq_operations debug_seq_ops = {
2371 .start = dev_seq_start,
2372 .next = dev_seq_next,
2373 .stop = dev_seq_stop,
2374 .show = sg_proc_seq_show_debug,
2375};
2376
2377static int
2378sg_proc_init(void)
2379{
2380 struct proc_dir_entry *p;
2381
2382 p = proc_mkdir("scsi/sg", NULL);
2383 if (!p)
2384 return 1;
2385
2386 proc_create("allow_dio", S_IRUGO | S_IWUSR, p, &adio_proc_ops);
2387 proc_create_seq("debug", S_IRUGO, p, &debug_seq_ops);
2388 proc_create("def_reserved_size", S_IRUGO | S_IWUSR, p, &dressz_proc_ops);
2389 proc_create_single("device_hdr", S_IRUGO, p, sg_proc_seq_show_devhdr);
2390 proc_create_seq("devices", S_IRUGO, p, &dev_seq_ops);
2391 proc_create_seq("device_strs", S_IRUGO, p, &devstrs_seq_ops);
2392 proc_create_single("version", S_IRUGO, p, sg_proc_seq_show_version);
2393 return 0;
2394}
2395
2396
2397static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2398{
2399 seq_printf(s, "%d\n", *((int *)s->private));
2400 return 0;
2401}
2402
2403static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2404{
2405 return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2406}
2407
2408static ssize_t
2409sg_proc_write_adio(struct file *filp, const char __user *buffer,
2410 size_t count, loff_t *off)
2411{
2412 int err;
2413 unsigned long num;
2414
2415 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2416 return -EACCES;
2417 err = kstrtoul_from_user(buffer, count, 0, &num);
2418 if (err)
2419 return err;
2420 sg_allow_dio = num ? 1 : 0;
2421 return count;
2422}
2423
2424static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2425{
2426 return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2427}
2428
2429static ssize_t
2430sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2431 size_t count, loff_t *off)
2432{
2433 int err;
2434 unsigned long k = ULONG_MAX;
2435
2436 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2437 return -EACCES;
2438
2439 err = kstrtoul_from_user(buffer, count, 0, &k);
2440 if (err)
2441 return err;
2442 if (k <= 1048576) { /* limit "big buff" to 1 MB */
2443 sg_big_buff = k;
2444 return count;
2445 }
2446 return -ERANGE;
2447}
2448
2449static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2450{
2451 seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2452 sg_version_date);
2453 return 0;
2454}
2455
2456static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2457{
2458 seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2459 return 0;
2460}
2461
2462struct sg_proc_deviter {
2463 loff_t index;
2464 size_t max;
2465};
2466
2467static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2468{
2469 struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2470
2471 s->private = it;
2472 if (! it)
2473 return NULL;
2474
2475 it->index = *pos;
2476 it->max = sg_last_dev();
2477 if (it->index >= it->max)
2478 return NULL;
2479 return it;
2480}
2481
2482static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2483{
2484 struct sg_proc_deviter * it = s->private;
2485
2486 *pos = ++it->index;
2487 return (it->index < it->max) ? it : NULL;
2488}
2489
2490static void dev_seq_stop(struct seq_file *s, void *v)
2491{
2492 kfree(s->private);
2493}
2494
2495static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2496{
2497 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2498 Sg_device *sdp;
2499 struct scsi_device *scsidp;
2500 unsigned long iflags;
2501
2502 read_lock_irqsave(&sg_index_lock, iflags);
2503 sdp = it ? sg_lookup_dev(it->index) : NULL;
2504 if ((NULL == sdp) || (NULL == sdp->device) ||
2505 (atomic_read(&sdp->detaching)))
2506 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2507 else {
2508 scsidp = sdp->device;
2509 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2510 scsidp->host->host_no, scsidp->channel,
2511 scsidp->id, scsidp->lun, (int) scsidp->type,
2512 1,
2513 (int) scsidp->queue_depth,
2514 (int) atomic_read(&scsidp->device_busy),
2515 (int) scsi_device_online(scsidp));
2516 }
2517 read_unlock_irqrestore(&sg_index_lock, iflags);
2518 return 0;
2519}
2520
2521static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2522{
2523 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2524 Sg_device *sdp;
2525 struct scsi_device *scsidp;
2526 unsigned long iflags;
2527
2528 read_lock_irqsave(&sg_index_lock, iflags);
2529 sdp = it ? sg_lookup_dev(it->index) : NULL;
2530 scsidp = sdp ? sdp->device : NULL;
2531 if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2532 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2533 scsidp->vendor, scsidp->model, scsidp->rev);
2534 else
2535 seq_puts(s, "<no active device>\n");
2536 read_unlock_irqrestore(&sg_index_lock, iflags);
2537 return 0;
2538}
2539
2540/* must be called while holding sg_index_lock */
2541static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2542{
2543 int k, new_interface, blen, usg;
2544 Sg_request *srp;
2545 Sg_fd *fp;
2546 const sg_io_hdr_t *hp;
2547 const char * cp;
2548 unsigned int ms;
2549
2550 k = 0;
2551 list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2552 k++;
2553 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2554 seq_printf(s, " FD(%d): timeout=%dms bufflen=%d "
2555 "(res)sgat=%d low_dma=%d\n", k,
2556 jiffies_to_msecs(fp->timeout),
2557 fp->reserve.bufflen,
2558 (int) fp->reserve.k_use_sg,
2559 (int) sdp->device->host->unchecked_isa_dma);
2560 seq_printf(s, " cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2561 (int) fp->cmd_q, (int) fp->force_packid,
2562 (int) fp->keep_orphan);
2563 list_for_each_entry(srp, &fp->rq_list, entry) {
2564 hp = &srp->header;
2565 new_interface = (hp->interface_id == '\0') ? 0 : 1;
2566 if (srp->res_used) {
2567 if (new_interface &&
2568 (SG_FLAG_MMAP_IO & hp->flags))
2569 cp = " mmap>> ";
2570 else
2571 cp = " rb>> ";
2572 } else {
2573 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2574 cp = " dio>> ";
2575 else
2576 cp = " ";
2577 }
2578 seq_puts(s, cp);
2579 blen = srp->data.bufflen;
2580 usg = srp->data.k_use_sg;
2581 seq_puts(s, srp->done ?
2582 ((1 == srp->done) ? "rcv:" : "fin:")
2583 : "act:");
2584 seq_printf(s, " id=%d blen=%d",
2585 srp->header.pack_id, blen);
2586 if (srp->done)
2587 seq_printf(s, " dur=%d", hp->duration);
2588 else {
2589 ms = jiffies_to_msecs(jiffies);
2590 seq_printf(s, " t_o/elap=%d/%d",
2591 (new_interface ? hp->timeout :
2592 jiffies_to_msecs(fp->timeout)),
2593 (ms > hp->duration ? ms - hp->duration : 0));
2594 }
2595 seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2596 (int) srp->data.cmd_opcode);
2597 }
2598 if (list_empty(&fp->rq_list))
2599 seq_puts(s, " No requests active\n");
2600 read_unlock(&fp->rq_list_lock);
2601 }
2602}
2603
2604static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2605{
2606 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2607 Sg_device *sdp;
2608 unsigned long iflags;
2609
2610 if (it && (0 == it->index))
2611 seq_printf(s, "max_active_device=%d def_reserved_size=%d\n",
2612 (int)it->max, sg_big_buff);
2613
2614 read_lock_irqsave(&sg_index_lock, iflags);
2615 sdp = it ? sg_lookup_dev(it->index) : NULL;
2616 if (NULL == sdp)
2617 goto skip;
2618 read_lock(&sdp->sfd_lock);
2619 if (!list_empty(&sdp->sfds)) {
2620 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2621 if (atomic_read(&sdp->detaching))
2622 seq_puts(s, "detaching pending close ");
2623 else if (sdp->device) {
2624 struct scsi_device *scsidp = sdp->device;
2625
2626 seq_printf(s, "%d:%d:%d:%llu em=%d",
2627 scsidp->host->host_no,
2628 scsidp->channel, scsidp->id,
2629 scsidp->lun,
2630 scsidp->host->hostt->emulated);
2631 }
2632 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2633 sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2634 sg_proc_debug_helper(s, sdp);
2635 }
2636 read_unlock(&sdp->sfd_lock);
2637skip:
2638 read_unlock_irqrestore(&sg_index_lock, iflags);
2639 return 0;
2640}
2641
2642#endif /* CONFIG_SCSI_PROC_FS */
2643
2644module_init(init_sg);
2645module_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/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 struct scsi_device *device;
289 Sg_device *sdp;
290 Sg_fd *sfp;
291 int retval;
292
293 nonseekable_open(inode, filp);
294 if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
295 return -EPERM; /* Can't lock it with read only access */
296 sdp = sg_get_dev(dev);
297 if (IS_ERR(sdp))
298 return PTR_ERR(sdp);
299
300 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
301 "sg_open: flags=0x%x\n", flags));
302
303 /* This driver's module count bumped by fops_get in <linux/fs.h> */
304 /* Prevent the device driver from vanishing while we sleep */
305 device = sdp->device;
306 retval = scsi_device_get(device);
307 if (retval)
308 goto sg_put;
309
310 /* scsi_block_when_processing_errors() may block so bypass
311 * check if O_NONBLOCK. Permits SCSI commands to be issued
312 * during error recovery. Tread carefully. */
313 if (!((flags & O_NONBLOCK) ||
314 scsi_block_when_processing_errors(device))) {
315 retval = -ENXIO;
316 /* we are in error recovery for this device */
317 goto sdp_put;
318 }
319
320 mutex_lock(&sdp->open_rel_lock);
321 if (flags & O_NONBLOCK) {
322 if (flags & O_EXCL) {
323 if (sdp->open_cnt > 0) {
324 retval = -EBUSY;
325 goto error_mutex_locked;
326 }
327 } else {
328 if (sdp->exclude) {
329 retval = -EBUSY;
330 goto error_mutex_locked;
331 }
332 }
333 } else {
334 retval = open_wait(sdp, flags);
335 if (retval) /* -ERESTARTSYS or -ENODEV */
336 goto error_mutex_locked;
337 }
338
339 /* N.B. at this point we are holding the open_rel_lock */
340 if (flags & O_EXCL)
341 sdp->exclude = true;
342
343 if (sdp->open_cnt < 1) { /* no existing opens */
344 sdp->sgdebug = 0;
345 q = device->request_queue;
346 sdp->sg_tablesize = queue_max_segments(q);
347 }
348 sfp = sg_add_sfp(sdp);
349 if (IS_ERR(sfp)) {
350 retval = PTR_ERR(sfp);
351 goto out_undo;
352 }
353
354 filp->private_data = sfp;
355 sdp->open_cnt++;
356 mutex_unlock(&sdp->open_rel_lock);
357
358 retval = 0;
359sg_put:
360 kref_put(&sdp->d_ref, sg_device_destroy);
361 return retval;
362
363out_undo:
364 if (flags & O_EXCL) {
365 sdp->exclude = false; /* undo if error */
366 wake_up_interruptible(&sdp->open_wait);
367 }
368error_mutex_locked:
369 mutex_unlock(&sdp->open_rel_lock);
370sdp_put:
371 kref_put(&sdp->d_ref, sg_device_destroy);
372 scsi_device_put(device);
373 return retval;
374}
375
376/* Release resources associated with a successful sg_open()
377 * Returns 0 on success, else a negated errno value */
378static int
379sg_release(struct inode *inode, struct file *filp)
380{
381 Sg_device *sdp;
382 Sg_fd *sfp;
383
384 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
385 return -ENXIO;
386 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
387
388 mutex_lock(&sdp->open_rel_lock);
389 sdp->open_cnt--;
390
391 /* possibly many open()s waiting on exlude clearing, start many;
392 * only open(O_EXCL)s wait on 0==open_cnt so only start one */
393 if (sdp->exclude) {
394 sdp->exclude = false;
395 wake_up_interruptible_all(&sdp->open_wait);
396 } else if (0 == sdp->open_cnt) {
397 wake_up_interruptible(&sdp->open_wait);
398 }
399 mutex_unlock(&sdp->open_rel_lock);
400 kref_put(&sfp->f_ref, sg_remove_sfp);
401 return 0;
402}
403
404static int get_sg_io_pack_id(int *pack_id, void __user *buf, size_t count)
405{
406 struct sg_header __user *old_hdr = buf;
407 int reply_len;
408
409 if (count >= SZ_SG_HEADER) {
410 /* negative reply_len means v3 format, otherwise v1/v2 */
411 if (get_user(reply_len, &old_hdr->reply_len))
412 return -EFAULT;
413
414 if (reply_len >= 0)
415 return get_user(*pack_id, &old_hdr->pack_id);
416
417 if (in_compat_syscall() &&
418 count >= sizeof(struct compat_sg_io_hdr)) {
419 struct compat_sg_io_hdr __user *hp = buf;
420
421 return get_user(*pack_id, &hp->pack_id);
422 }
423
424 if (count >= sizeof(struct sg_io_hdr)) {
425 struct sg_io_hdr __user *hp = buf;
426
427 return get_user(*pack_id, &hp->pack_id);
428 }
429 }
430
431 /* no valid header was passed, so ignore the pack_id */
432 *pack_id = -1;
433 return 0;
434}
435
436static ssize_t
437sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
438{
439 Sg_device *sdp;
440 Sg_fd *sfp;
441 Sg_request *srp;
442 int req_pack_id = -1;
443 bool busy;
444 sg_io_hdr_t *hp;
445 struct sg_header *old_hdr;
446 int retval;
447
448 /*
449 * This could cause a response to be stranded. Close the associated
450 * file descriptor to free up any resources being held.
451 */
452 retval = sg_check_file_access(filp, __func__);
453 if (retval)
454 return retval;
455
456 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
457 return -ENXIO;
458 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
459 "sg_read: count=%d\n", (int) count));
460
461 if (sfp->force_packid)
462 retval = get_sg_io_pack_id(&req_pack_id, buf, count);
463 if (retval)
464 return retval;
465
466 srp = sg_get_rq_mark(sfp, req_pack_id, &busy);
467 if (!srp) { /* now wait on packet to arrive */
468 if (filp->f_flags & O_NONBLOCK)
469 return -EAGAIN;
470 retval = wait_event_interruptible(sfp->read_wait,
471 ((srp = sg_get_rq_mark(sfp, req_pack_id, &busy)) ||
472 (!busy && atomic_read(&sdp->detaching))));
473 if (!srp)
474 /* signal or detaching */
475 return retval ? retval : -ENODEV;
476 }
477 if (srp->header.interface_id != '\0')
478 return sg_new_read(sfp, buf, count, srp);
479
480 hp = &srp->header;
481 old_hdr = kzalloc(SZ_SG_HEADER, GFP_KERNEL);
482 if (!old_hdr)
483 return -ENOMEM;
484
485 old_hdr->reply_len = (int) hp->timeout;
486 old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
487 old_hdr->pack_id = hp->pack_id;
488 old_hdr->twelve_byte =
489 ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
490 old_hdr->target_status = hp->masked_status;
491 old_hdr->host_status = hp->host_status;
492 old_hdr->driver_status = hp->driver_status;
493 if ((CHECK_CONDITION & hp->masked_status) ||
494 (srp->sense_b[0] & 0x70) == 0x70) {
495 old_hdr->driver_status = DRIVER_SENSE;
496 memcpy(old_hdr->sense_buffer, srp->sense_b,
497 sizeof (old_hdr->sense_buffer));
498 }
499 switch (hp->host_status) {
500 /* This setup of 'result' is for backward compatibility and is best
501 ignored by the user who should use target, host + driver status */
502 case DID_OK:
503 case DID_PASSTHROUGH:
504 case DID_SOFT_ERROR:
505 old_hdr->result = 0;
506 break;
507 case DID_NO_CONNECT:
508 case DID_BUS_BUSY:
509 case DID_TIME_OUT:
510 old_hdr->result = EBUSY;
511 break;
512 case DID_BAD_TARGET:
513 case DID_ABORT:
514 case DID_PARITY:
515 case DID_RESET:
516 case DID_BAD_INTR:
517 old_hdr->result = EIO;
518 break;
519 case DID_ERROR:
520 old_hdr->result = (srp->sense_b[0] == 0 &&
521 hp->masked_status == GOOD) ? 0 : EIO;
522 break;
523 default:
524 old_hdr->result = EIO;
525 break;
526 }
527
528 /* Now copy the result back to the user buffer. */
529 if (count >= SZ_SG_HEADER) {
530 if (copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
531 retval = -EFAULT;
532 goto free_old_hdr;
533 }
534 buf += SZ_SG_HEADER;
535 if (count > old_hdr->reply_len)
536 count = old_hdr->reply_len;
537 if (count > SZ_SG_HEADER) {
538 if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
539 retval = -EFAULT;
540 goto free_old_hdr;
541 }
542 }
543 } else
544 count = (old_hdr->result == 0) ? 0 : -EIO;
545 sg_finish_rem_req(srp);
546 sg_remove_request(sfp, srp);
547 retval = count;
548free_old_hdr:
549 kfree(old_hdr);
550 return retval;
551}
552
553static ssize_t
554sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
555{
556 sg_io_hdr_t *hp = &srp->header;
557 int err = 0, err2;
558 int len;
559
560 if (in_compat_syscall()) {
561 if (count < sizeof(struct compat_sg_io_hdr)) {
562 err = -EINVAL;
563 goto err_out;
564 }
565 } else if (count < SZ_SG_IO_HDR) {
566 err = -EINVAL;
567 goto err_out;
568 }
569 hp->sb_len_wr = 0;
570 if ((hp->mx_sb_len > 0) && hp->sbp) {
571 if ((CHECK_CONDITION & hp->masked_status) ||
572 (srp->sense_b[0] & 0x70) == 0x70) {
573 int sb_len = SCSI_SENSE_BUFFERSIZE;
574 sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
575 len = 8 + (int) srp->sense_b[7]; /* Additional sense length field */
576 len = (len > sb_len) ? sb_len : len;
577 if (copy_to_user(hp->sbp, srp->sense_b, len)) {
578 err = -EFAULT;
579 goto err_out;
580 }
581 hp->driver_status = DRIVER_SENSE;
582 hp->sb_len_wr = len;
583 }
584 }
585 if (hp->masked_status || hp->host_status || hp->driver_status)
586 hp->info |= SG_INFO_CHECK;
587 err = put_sg_io_hdr(hp, buf);
588err_out:
589 err2 = sg_finish_rem_req(srp);
590 sg_remove_request(sfp, srp);
591 return err ? : err2 ? : count;
592}
593
594static ssize_t
595sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
596{
597 int mxsize, cmd_size, k;
598 int input_size, blocking;
599 unsigned char opcode;
600 Sg_device *sdp;
601 Sg_fd *sfp;
602 Sg_request *srp;
603 struct sg_header old_hdr;
604 sg_io_hdr_t *hp;
605 unsigned char cmnd[SG_MAX_CDB_SIZE];
606 int retval;
607
608 retval = sg_check_file_access(filp, __func__);
609 if (retval)
610 return retval;
611
612 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
613 return -ENXIO;
614 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
615 "sg_write: count=%d\n", (int) count));
616 if (atomic_read(&sdp->detaching))
617 return -ENODEV;
618 if (!((filp->f_flags & O_NONBLOCK) ||
619 scsi_block_when_processing_errors(sdp->device)))
620 return -ENXIO;
621
622 if (count < SZ_SG_HEADER)
623 return -EIO;
624 if (copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
625 return -EFAULT;
626 blocking = !(filp->f_flags & O_NONBLOCK);
627 if (old_hdr.reply_len < 0)
628 return sg_new_write(sfp, filp, buf, count,
629 blocking, 0, 0, NULL);
630 if (count < (SZ_SG_HEADER + 6))
631 return -EIO; /* The minimum scsi command length is 6 bytes. */
632
633 buf += SZ_SG_HEADER;
634 if (get_user(opcode, buf))
635 return -EFAULT;
636
637 if (!(srp = sg_add_request(sfp))) {
638 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
639 "sg_write: queue full\n"));
640 return -EDOM;
641 }
642 mutex_lock(&sfp->f_mutex);
643 if (sfp->next_cmd_len > 0) {
644 cmd_size = sfp->next_cmd_len;
645 sfp->next_cmd_len = 0; /* reset so only this write() effected */
646 } else {
647 cmd_size = COMMAND_SIZE(opcode); /* based on SCSI command group */
648 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
649 cmd_size = 12;
650 }
651 mutex_unlock(&sfp->f_mutex);
652 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
653 "sg_write: scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
654/* Determine buffer size. */
655 input_size = count - cmd_size;
656 mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
657 mxsize -= SZ_SG_HEADER;
658 input_size -= SZ_SG_HEADER;
659 if (input_size < 0) {
660 sg_remove_request(sfp, srp);
661 return -EIO; /* User did not pass enough bytes for this command. */
662 }
663 hp = &srp->header;
664 hp->interface_id = '\0'; /* indicator of old interface tunnelled */
665 hp->cmd_len = (unsigned char) cmd_size;
666 hp->iovec_count = 0;
667 hp->mx_sb_len = 0;
668 if (input_size > 0)
669 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
670 SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
671 else
672 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
673 hp->dxfer_len = mxsize;
674 if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
675 (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
676 hp->dxferp = (char __user *)buf + cmd_size;
677 else
678 hp->dxferp = NULL;
679 hp->sbp = NULL;
680 hp->timeout = old_hdr.reply_len; /* structure abuse ... */
681 hp->flags = input_size; /* structure abuse ... */
682 hp->pack_id = old_hdr.pack_id;
683 hp->usr_ptr = NULL;
684 if (copy_from_user(cmnd, buf, cmd_size)) {
685 sg_remove_request(sfp, srp);
686 return -EFAULT;
687 }
688 /*
689 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
690 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
691 * is a non-zero input_size, so emit a warning.
692 */
693 if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
694 printk_ratelimited(KERN_WARNING
695 "sg_write: data in/out %d/%d bytes "
696 "for SCSI command 0x%x-- guessing "
697 "data in;\n program %s not setting "
698 "count and/or reply_len properly\n",
699 old_hdr.reply_len - (int)SZ_SG_HEADER,
700 input_size, (unsigned int) cmnd[0],
701 current->comm);
702 }
703 k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
704 return (k < 0) ? k : count;
705}
706
707static ssize_t
708sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
709 size_t count, int blocking, int read_only, int sg_io_owned,
710 Sg_request **o_srp)
711{
712 int k;
713 Sg_request *srp;
714 sg_io_hdr_t *hp;
715 unsigned char cmnd[SG_MAX_CDB_SIZE];
716 int timeout;
717 unsigned long ul_timeout;
718
719 if (count < SZ_SG_IO_HDR)
720 return -EINVAL;
721
722 sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
723 if (!(srp = sg_add_request(sfp))) {
724 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
725 "sg_new_write: queue full\n"));
726 return -EDOM;
727 }
728 srp->sg_io_owned = sg_io_owned;
729 hp = &srp->header;
730 if (get_sg_io_hdr(hp, buf)) {
731 sg_remove_request(sfp, srp);
732 return -EFAULT;
733 }
734 if (hp->interface_id != 'S') {
735 sg_remove_request(sfp, srp);
736 return -ENOSYS;
737 }
738 if (hp->flags & SG_FLAG_MMAP_IO) {
739 if (hp->dxfer_len > sfp->reserve.bufflen) {
740 sg_remove_request(sfp, srp);
741 return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
742 }
743 if (hp->flags & SG_FLAG_DIRECT_IO) {
744 sg_remove_request(sfp, srp);
745 return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
746 }
747 if (sfp->res_in_use) {
748 sg_remove_request(sfp, srp);
749 return -EBUSY; /* reserve buffer already being used */
750 }
751 }
752 ul_timeout = msecs_to_jiffies(srp->header.timeout);
753 timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
754 if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
755 sg_remove_request(sfp, srp);
756 return -EMSGSIZE;
757 }
758 if (copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
759 sg_remove_request(sfp, srp);
760 return -EFAULT;
761 }
762 if (read_only && sg_allow_access(file, cmnd)) {
763 sg_remove_request(sfp, srp);
764 return -EPERM;
765 }
766 k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
767 if (k < 0)
768 return k;
769 if (o_srp)
770 *o_srp = srp;
771 return count;
772}
773
774static int
775sg_common_write(Sg_fd * sfp, Sg_request * srp,
776 unsigned char *cmnd, int timeout, int blocking)
777{
778 int k, at_head;
779 Sg_device *sdp = sfp->parentdp;
780 sg_io_hdr_t *hp = &srp->header;
781
782 srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
783 hp->status = 0;
784 hp->masked_status = 0;
785 hp->msg_status = 0;
786 hp->info = 0;
787 hp->host_status = 0;
788 hp->driver_status = 0;
789 hp->resid = 0;
790 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
791 "sg_common_write: scsi opcode=0x%02x, cmd_size=%d\n",
792 (int) cmnd[0], (int) hp->cmd_len));
793
794 if (hp->dxfer_len >= SZ_256M) {
795 sg_remove_request(sfp, srp);
796 return -EINVAL;
797 }
798
799 k = sg_start_req(srp, cmnd);
800 if (k) {
801 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
802 "sg_common_write: start_req err=%d\n", k));
803 sg_finish_rem_req(srp);
804 sg_remove_request(sfp, srp);
805 return k; /* probably out of space --> ENOMEM */
806 }
807 if (atomic_read(&sdp->detaching)) {
808 if (srp->bio) {
809 blk_mq_free_request(srp->rq);
810 srp->rq = NULL;
811 }
812
813 sg_finish_rem_req(srp);
814 sg_remove_request(sfp, srp);
815 return -ENODEV;
816 }
817
818 hp->duration = jiffies_to_msecs(jiffies);
819 if (hp->interface_id != '\0' && /* v3 (or later) interface */
820 (SG_FLAG_Q_AT_TAIL & hp->flags))
821 at_head = 0;
822 else
823 at_head = 1;
824
825 srp->rq->timeout = timeout;
826 kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
827 srp->rq->end_io = sg_rq_end_io;
828 blk_execute_rq_nowait(srp->rq, at_head);
829 return 0;
830}
831
832static int srp_done(Sg_fd *sfp, Sg_request *srp)
833{
834 unsigned long flags;
835 int ret;
836
837 read_lock_irqsave(&sfp->rq_list_lock, flags);
838 ret = srp->done;
839 read_unlock_irqrestore(&sfp->rq_list_lock, flags);
840 return ret;
841}
842
843static int max_sectors_bytes(struct request_queue *q)
844{
845 unsigned int max_sectors = queue_max_sectors(q);
846
847 max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
848
849 return max_sectors << 9;
850}
851
852static void
853sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
854{
855 Sg_request *srp;
856 int val;
857 unsigned int ms;
858
859 val = 0;
860 list_for_each_entry(srp, &sfp->rq_list, entry) {
861 if (val >= SG_MAX_QUEUE)
862 break;
863 rinfo[val].req_state = srp->done + 1;
864 rinfo[val].problem =
865 srp->header.masked_status &
866 srp->header.host_status &
867 srp->header.driver_status;
868 if (srp->done)
869 rinfo[val].duration =
870 srp->header.duration;
871 else {
872 ms = jiffies_to_msecs(jiffies);
873 rinfo[val].duration =
874 (ms > srp->header.duration) ?
875 (ms - srp->header.duration) : 0;
876 }
877 rinfo[val].orphan = srp->orphan;
878 rinfo[val].sg_io_owned = srp->sg_io_owned;
879 rinfo[val].pack_id = srp->header.pack_id;
880 rinfo[val].usr_ptr = srp->header.usr_ptr;
881 val++;
882 }
883}
884
885#ifdef CONFIG_COMPAT
886struct compat_sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
887 char req_state;
888 char orphan;
889 char sg_io_owned;
890 char problem;
891 int pack_id;
892 compat_uptr_t usr_ptr;
893 unsigned int duration;
894 int unused;
895};
896
897static int put_compat_request_table(struct compat_sg_req_info __user *o,
898 struct sg_req_info *rinfo)
899{
900 int i;
901 for (i = 0; i < SG_MAX_QUEUE; i++) {
902 if (copy_to_user(o + i, rinfo + i, offsetof(sg_req_info_t, usr_ptr)) ||
903 put_user((uintptr_t)rinfo[i].usr_ptr, &o[i].usr_ptr) ||
904 put_user(rinfo[i].duration, &o[i].duration) ||
905 put_user(rinfo[i].unused, &o[i].unused))
906 return -EFAULT;
907 }
908 return 0;
909}
910#endif
911
912static long
913sg_ioctl_common(struct file *filp, Sg_device *sdp, Sg_fd *sfp,
914 unsigned int cmd_in, void __user *p)
915{
916 int __user *ip = p;
917 int result, val, read_only;
918 Sg_request *srp;
919 unsigned long iflags;
920
921 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
922 "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
923 read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
924
925 switch (cmd_in) {
926 case SG_IO:
927 if (atomic_read(&sdp->detaching))
928 return -ENODEV;
929 if (!scsi_block_when_processing_errors(sdp->device))
930 return -ENXIO;
931 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
932 1, read_only, 1, &srp);
933 if (result < 0)
934 return result;
935 result = wait_event_interruptible(sfp->read_wait,
936 srp_done(sfp, srp));
937 write_lock_irq(&sfp->rq_list_lock);
938 if (srp->done) {
939 srp->done = 2;
940 write_unlock_irq(&sfp->rq_list_lock);
941 result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
942 return (result < 0) ? result : 0;
943 }
944 srp->orphan = 1;
945 write_unlock_irq(&sfp->rq_list_lock);
946 return result; /* -ERESTARTSYS because signal hit process */
947 case SG_SET_TIMEOUT:
948 result = get_user(val, ip);
949 if (result)
950 return result;
951 if (val < 0)
952 return -EIO;
953 if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
954 val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
955 INT_MAX);
956 sfp->timeout_user = val;
957 sfp->timeout = mult_frac(val, HZ, USER_HZ);
958
959 return 0;
960 case SG_GET_TIMEOUT: /* N.B. User receives timeout as return value */
961 /* strange ..., for backward compatibility */
962 return sfp->timeout_user;
963 case SG_SET_FORCE_LOW_DMA:
964 /*
965 * N.B. This ioctl never worked properly, but failed to
966 * return an error value. So returning '0' to keep compability
967 * with legacy applications.
968 */
969 return 0;
970 case SG_GET_LOW_DMA:
971 return put_user(0, ip);
972 case SG_GET_SCSI_ID:
973 {
974 sg_scsi_id_t v;
975
976 if (atomic_read(&sdp->detaching))
977 return -ENODEV;
978 memset(&v, 0, sizeof(v));
979 v.host_no = sdp->device->host->host_no;
980 v.channel = sdp->device->channel;
981 v.scsi_id = sdp->device->id;
982 v.lun = sdp->device->lun;
983 v.scsi_type = sdp->device->type;
984 v.h_cmd_per_lun = sdp->device->host->cmd_per_lun;
985 v.d_queue_depth = sdp->device->queue_depth;
986 if (copy_to_user(p, &v, sizeof(sg_scsi_id_t)))
987 return -EFAULT;
988 return 0;
989 }
990 case SG_SET_FORCE_PACK_ID:
991 result = get_user(val, ip);
992 if (result)
993 return result;
994 sfp->force_packid = val ? 1 : 0;
995 return 0;
996 case SG_GET_PACK_ID:
997 read_lock_irqsave(&sfp->rq_list_lock, iflags);
998 list_for_each_entry(srp, &sfp->rq_list, entry) {
999 if ((1 == srp->done) && (!srp->sg_io_owned)) {
1000 read_unlock_irqrestore(&sfp->rq_list_lock,
1001 iflags);
1002 return put_user(srp->header.pack_id, ip);
1003 }
1004 }
1005 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1006 return put_user(-1, ip);
1007 case SG_GET_NUM_WAITING:
1008 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1009 val = 0;
1010 list_for_each_entry(srp, &sfp->rq_list, entry) {
1011 if ((1 == srp->done) && (!srp->sg_io_owned))
1012 ++val;
1013 }
1014 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1015 return put_user(val, ip);
1016 case SG_GET_SG_TABLESIZE:
1017 return put_user(sdp->sg_tablesize, ip);
1018 case SG_SET_RESERVED_SIZE:
1019 result = get_user(val, ip);
1020 if (result)
1021 return result;
1022 if (val < 0)
1023 return -EINVAL;
1024 val = min_t(int, val,
1025 max_sectors_bytes(sdp->device->request_queue));
1026 mutex_lock(&sfp->f_mutex);
1027 if (val != sfp->reserve.bufflen) {
1028 if (sfp->mmap_called ||
1029 sfp->res_in_use) {
1030 mutex_unlock(&sfp->f_mutex);
1031 return -EBUSY;
1032 }
1033
1034 sg_remove_scat(sfp, &sfp->reserve);
1035 sg_build_reserve(sfp, val);
1036 }
1037 mutex_unlock(&sfp->f_mutex);
1038 return 0;
1039 case SG_GET_RESERVED_SIZE:
1040 val = min_t(int, sfp->reserve.bufflen,
1041 max_sectors_bytes(sdp->device->request_queue));
1042 return put_user(val, ip);
1043 case SG_SET_COMMAND_Q:
1044 result = get_user(val, ip);
1045 if (result)
1046 return result;
1047 sfp->cmd_q = val ? 1 : 0;
1048 return 0;
1049 case SG_GET_COMMAND_Q:
1050 return put_user((int) sfp->cmd_q, ip);
1051 case SG_SET_KEEP_ORPHAN:
1052 result = get_user(val, ip);
1053 if (result)
1054 return result;
1055 sfp->keep_orphan = val;
1056 return 0;
1057 case SG_GET_KEEP_ORPHAN:
1058 return put_user((int) sfp->keep_orphan, ip);
1059 case SG_NEXT_CMD_LEN:
1060 result = get_user(val, ip);
1061 if (result)
1062 return result;
1063 if (val > SG_MAX_CDB_SIZE)
1064 return -ENOMEM;
1065 sfp->next_cmd_len = (val > 0) ? val : 0;
1066 return 0;
1067 case SG_GET_VERSION_NUM:
1068 return put_user(sg_version_num, ip);
1069 case SG_GET_ACCESS_COUNT:
1070 /* faked - we don't have a real access count anymore */
1071 val = (sdp->device ? 1 : 0);
1072 return put_user(val, ip);
1073 case SG_GET_REQUEST_TABLE:
1074 {
1075 sg_req_info_t *rinfo;
1076
1077 rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
1078 GFP_KERNEL);
1079 if (!rinfo)
1080 return -ENOMEM;
1081 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1082 sg_fill_request_table(sfp, rinfo);
1083 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1084 #ifdef CONFIG_COMPAT
1085 if (in_compat_syscall())
1086 result = put_compat_request_table(p, rinfo);
1087 else
1088 #endif
1089 result = copy_to_user(p, rinfo,
1090 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1091 result = result ? -EFAULT : 0;
1092 kfree(rinfo);
1093 return result;
1094 }
1095 case SG_EMULATED_HOST:
1096 if (atomic_read(&sdp->detaching))
1097 return -ENODEV;
1098 return put_user(sdp->device->host->hostt->emulated, ip);
1099 case SCSI_IOCTL_SEND_COMMAND:
1100 if (atomic_read(&sdp->detaching))
1101 return -ENODEV;
1102 return scsi_ioctl(sdp->device, filp->f_mode & FMODE_WRITE,
1103 cmd_in, p);
1104 case SG_SET_DEBUG:
1105 result = get_user(val, ip);
1106 if (result)
1107 return result;
1108 sdp->sgdebug = (char) val;
1109 return 0;
1110 case BLKSECTGET:
1111 return put_user(max_sectors_bytes(sdp->device->request_queue),
1112 ip);
1113 case BLKTRACESETUP:
1114 return blk_trace_setup(sdp->device->request_queue, sdp->name,
1115 MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1116 NULL, p);
1117 case BLKTRACESTART:
1118 return blk_trace_startstop(sdp->device->request_queue, 1);
1119 case BLKTRACESTOP:
1120 return blk_trace_startstop(sdp->device->request_queue, 0);
1121 case BLKTRACETEARDOWN:
1122 return blk_trace_remove(sdp->device->request_queue);
1123 case SCSI_IOCTL_GET_IDLUN:
1124 case SCSI_IOCTL_GET_BUS_NUMBER:
1125 case SCSI_IOCTL_PROBE_HOST:
1126 case SG_GET_TRANSFORM:
1127 case SG_SCSI_RESET:
1128 if (atomic_read(&sdp->detaching))
1129 return -ENODEV;
1130 break;
1131 default:
1132 if (read_only)
1133 return -EPERM; /* don't know so take safe approach */
1134 break;
1135 }
1136
1137 result = scsi_ioctl_block_when_processing_errors(sdp->device,
1138 cmd_in, filp->f_flags & O_NDELAY);
1139 if (result)
1140 return result;
1141
1142 return -ENOIOCTLCMD;
1143}
1144
1145static long
1146sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1147{
1148 void __user *p = (void __user *)arg;
1149 Sg_device *sdp;
1150 Sg_fd *sfp;
1151 int ret;
1152
1153 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1154 return -ENXIO;
1155
1156 ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
1157 if (ret != -ENOIOCTLCMD)
1158 return ret;
1159 return scsi_ioctl(sdp->device, filp->f_mode & FMODE_WRITE, cmd_in, p);
1160}
1161
1162static __poll_t
1163sg_poll(struct file *filp, poll_table * wait)
1164{
1165 __poll_t res = 0;
1166 Sg_device *sdp;
1167 Sg_fd *sfp;
1168 Sg_request *srp;
1169 int count = 0;
1170 unsigned long iflags;
1171
1172 sfp = filp->private_data;
1173 if (!sfp)
1174 return EPOLLERR;
1175 sdp = sfp->parentdp;
1176 if (!sdp)
1177 return EPOLLERR;
1178 poll_wait(filp, &sfp->read_wait, wait);
1179 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1180 list_for_each_entry(srp, &sfp->rq_list, entry) {
1181 /* if any read waiting, flag it */
1182 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1183 res = EPOLLIN | EPOLLRDNORM;
1184 ++count;
1185 }
1186 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1187
1188 if (atomic_read(&sdp->detaching))
1189 res |= EPOLLHUP;
1190 else if (!sfp->cmd_q) {
1191 if (0 == count)
1192 res |= EPOLLOUT | EPOLLWRNORM;
1193 } else if (count < SG_MAX_QUEUE)
1194 res |= EPOLLOUT | EPOLLWRNORM;
1195 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1196 "sg_poll: res=0x%x\n", (__force u32) res));
1197 return res;
1198}
1199
1200static int
1201sg_fasync(int fd, struct file *filp, int mode)
1202{
1203 Sg_device *sdp;
1204 Sg_fd *sfp;
1205
1206 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1207 return -ENXIO;
1208 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1209 "sg_fasync: mode=%d\n", mode));
1210
1211 return fasync_helper(fd, filp, mode, &sfp->async_qp);
1212}
1213
1214static vm_fault_t
1215sg_vma_fault(struct vm_fault *vmf)
1216{
1217 struct vm_area_struct *vma = vmf->vma;
1218 Sg_fd *sfp;
1219 unsigned long offset, len, sa;
1220 Sg_scatter_hold *rsv_schp;
1221 int k, length;
1222
1223 if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1224 return VM_FAULT_SIGBUS;
1225 rsv_schp = &sfp->reserve;
1226 offset = vmf->pgoff << PAGE_SHIFT;
1227 if (offset >= rsv_schp->bufflen)
1228 return VM_FAULT_SIGBUS;
1229 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1230 "sg_vma_fault: offset=%lu, scatg=%d\n",
1231 offset, rsv_schp->k_use_sg));
1232 sa = vma->vm_start;
1233 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1234 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1235 len = vma->vm_end - sa;
1236 len = (len < length) ? len : length;
1237 if (offset < len) {
1238 struct page *page = nth_page(rsv_schp->pages[k],
1239 offset >> PAGE_SHIFT);
1240 get_page(page); /* increment page count */
1241 vmf->page = page;
1242 return 0; /* success */
1243 }
1244 sa += len;
1245 offset -= len;
1246 }
1247
1248 return VM_FAULT_SIGBUS;
1249}
1250
1251static const struct vm_operations_struct sg_mmap_vm_ops = {
1252 .fault = sg_vma_fault,
1253};
1254
1255static int
1256sg_mmap(struct file *filp, struct vm_area_struct *vma)
1257{
1258 Sg_fd *sfp;
1259 unsigned long req_sz, len, sa;
1260 Sg_scatter_hold *rsv_schp;
1261 int k, length;
1262 int ret = 0;
1263
1264 if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1265 return -ENXIO;
1266 req_sz = vma->vm_end - vma->vm_start;
1267 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1268 "sg_mmap starting, vm_start=%p, len=%d\n",
1269 (void *) vma->vm_start, (int) req_sz));
1270 if (vma->vm_pgoff)
1271 return -EINVAL; /* want no offset */
1272 rsv_schp = &sfp->reserve;
1273 mutex_lock(&sfp->f_mutex);
1274 if (req_sz > rsv_schp->bufflen) {
1275 ret = -ENOMEM; /* cannot map more than reserved buffer */
1276 goto out;
1277 }
1278
1279 sa = vma->vm_start;
1280 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1281 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1282 len = vma->vm_end - sa;
1283 len = (len < length) ? len : length;
1284 sa += len;
1285 }
1286
1287 sfp->mmap_called = 1;
1288 vm_flags_set(vma, VM_IO | VM_DONTEXPAND | VM_DONTDUMP);
1289 vma->vm_private_data = sfp;
1290 vma->vm_ops = &sg_mmap_vm_ops;
1291out:
1292 mutex_unlock(&sfp->f_mutex);
1293 return ret;
1294}
1295
1296static void
1297sg_rq_end_io_usercontext(struct work_struct *work)
1298{
1299 struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1300 struct sg_fd *sfp = srp->parentfp;
1301
1302 sg_finish_rem_req(srp);
1303 sg_remove_request(sfp, srp);
1304 kref_put(&sfp->f_ref, sg_remove_sfp);
1305}
1306
1307/*
1308 * This function is a "bottom half" handler that is called by the mid
1309 * level when a command is completed (or has failed).
1310 */
1311static enum rq_end_io_ret
1312sg_rq_end_io(struct request *rq, blk_status_t status)
1313{
1314 struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
1315 struct sg_request *srp = rq->end_io_data;
1316 Sg_device *sdp;
1317 Sg_fd *sfp;
1318 unsigned long iflags;
1319 unsigned int ms;
1320 char *sense;
1321 int result, resid, done = 1;
1322
1323 if (WARN_ON(srp->done != 0))
1324 return RQ_END_IO_NONE;
1325
1326 sfp = srp->parentfp;
1327 if (WARN_ON(sfp == NULL))
1328 return RQ_END_IO_NONE;
1329
1330 sdp = sfp->parentdp;
1331 if (unlikely(atomic_read(&sdp->detaching)))
1332 pr_info("%s: device detaching\n", __func__);
1333
1334 sense = scmd->sense_buffer;
1335 result = scmd->result;
1336 resid = scmd->resid_len;
1337
1338 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1339 "sg_cmd_done: pack_id=%d, res=0x%x\n",
1340 srp->header.pack_id, result));
1341 srp->header.resid = resid;
1342 ms = jiffies_to_msecs(jiffies);
1343 srp->header.duration = (ms > srp->header.duration) ?
1344 (ms - srp->header.duration) : 0;
1345 if (0 != result) {
1346 struct scsi_sense_hdr sshdr;
1347
1348 srp->header.status = 0xff & result;
1349 srp->header.masked_status = sg_status_byte(result);
1350 srp->header.msg_status = COMMAND_COMPLETE;
1351 srp->header.host_status = host_byte(result);
1352 srp->header.driver_status = driver_byte(result);
1353 if ((sdp->sgdebug > 0) &&
1354 ((CHECK_CONDITION == srp->header.masked_status) ||
1355 (COMMAND_TERMINATED == srp->header.masked_status)))
1356 __scsi_print_sense(sdp->device, __func__, sense,
1357 SCSI_SENSE_BUFFERSIZE);
1358
1359 /* Following if statement is a patch supplied by Eric Youngdale */
1360 if (driver_byte(result) != 0
1361 && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1362 && !scsi_sense_is_deferred(&sshdr)
1363 && sshdr.sense_key == UNIT_ATTENTION
1364 && sdp->device->removable) {
1365 /* Detected possible disc change. Set the bit - this */
1366 /* may be used if there are filesystems using this device */
1367 sdp->device->changed = 1;
1368 }
1369 }
1370
1371 if (scmd->sense_len)
1372 memcpy(srp->sense_b, scmd->sense_buffer, SCSI_SENSE_BUFFERSIZE);
1373
1374 /* Rely on write phase to clean out srp status values, so no "else" */
1375
1376 /*
1377 * Free the request as soon as it is complete so that its resources
1378 * can be reused without waiting for userspace to read() the
1379 * result. But keep the associated bio (if any) around until
1380 * blk_rq_unmap_user() can be called from user context.
1381 */
1382 srp->rq = NULL;
1383 blk_mq_free_request(rq);
1384
1385 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1386 if (unlikely(srp->orphan)) {
1387 if (sfp->keep_orphan)
1388 srp->sg_io_owned = 0;
1389 else
1390 done = 0;
1391 }
1392 srp->done = done;
1393 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1394
1395 if (likely(done)) {
1396 /* Now wake up any sg_read() that is waiting for this
1397 * packet.
1398 */
1399 wake_up_interruptible(&sfp->read_wait);
1400 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1401 kref_put(&sfp->f_ref, sg_remove_sfp);
1402 } else {
1403 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1404 schedule_work(&srp->ew.work);
1405 }
1406 return RQ_END_IO_NONE;
1407}
1408
1409static const struct file_operations sg_fops = {
1410 .owner = THIS_MODULE,
1411 .read = sg_read,
1412 .write = sg_write,
1413 .poll = sg_poll,
1414 .unlocked_ioctl = sg_ioctl,
1415 .compat_ioctl = compat_ptr_ioctl,
1416 .open = sg_open,
1417 .mmap = sg_mmap,
1418 .release = sg_release,
1419 .fasync = sg_fasync,
1420};
1421
1422static const struct class sg_sysfs_class = {
1423 .name = "scsi_generic"
1424};
1425
1426static int sg_sysfs_valid = 0;
1427
1428static Sg_device *
1429sg_alloc(struct scsi_device *scsidp)
1430{
1431 struct request_queue *q = scsidp->request_queue;
1432 Sg_device *sdp;
1433 unsigned long iflags;
1434 int error;
1435 u32 k;
1436
1437 sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1438 if (!sdp) {
1439 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1440 "failure\n", __func__);
1441 return ERR_PTR(-ENOMEM);
1442 }
1443
1444 idr_preload(GFP_KERNEL);
1445 write_lock_irqsave(&sg_index_lock, iflags);
1446
1447 error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1448 if (error < 0) {
1449 if (error == -ENOSPC) {
1450 sdev_printk(KERN_WARNING, scsidp,
1451 "Unable to attach sg device type=%d, minor number exceeds %d\n",
1452 scsidp->type, SG_MAX_DEVS - 1);
1453 error = -ENODEV;
1454 } else {
1455 sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1456 "allocation Sg_device failure: %d\n",
1457 __func__, error);
1458 }
1459 goto out_unlock;
1460 }
1461 k = error;
1462
1463 SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1464 "sg_alloc: dev=%d \n", k));
1465 sprintf(sdp->name, "sg%d", k);
1466 sdp->device = scsidp;
1467 mutex_init(&sdp->open_rel_lock);
1468 INIT_LIST_HEAD(&sdp->sfds);
1469 init_waitqueue_head(&sdp->open_wait);
1470 atomic_set(&sdp->detaching, 0);
1471 rwlock_init(&sdp->sfd_lock);
1472 sdp->sg_tablesize = queue_max_segments(q);
1473 sdp->index = k;
1474 kref_init(&sdp->d_ref);
1475 error = 0;
1476
1477out_unlock:
1478 write_unlock_irqrestore(&sg_index_lock, iflags);
1479 idr_preload_end();
1480
1481 if (error) {
1482 kfree(sdp);
1483 return ERR_PTR(error);
1484 }
1485 return sdp;
1486}
1487
1488static int
1489sg_add_device(struct device *cl_dev)
1490{
1491 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1492 Sg_device *sdp = NULL;
1493 struct cdev * cdev = NULL;
1494 int error;
1495 unsigned long iflags;
1496
1497 if (!blk_get_queue(scsidp->request_queue)) {
1498 pr_warn("%s: get scsi_device queue failed\n", __func__);
1499 return -ENODEV;
1500 }
1501
1502 error = -ENOMEM;
1503 cdev = cdev_alloc();
1504 if (!cdev) {
1505 pr_warn("%s: cdev_alloc failed\n", __func__);
1506 goto out;
1507 }
1508 cdev->owner = THIS_MODULE;
1509 cdev->ops = &sg_fops;
1510
1511 sdp = sg_alloc(scsidp);
1512 if (IS_ERR(sdp)) {
1513 pr_warn("%s: sg_alloc failed\n", __func__);
1514 error = PTR_ERR(sdp);
1515 goto out;
1516 }
1517
1518 error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1519 if (error)
1520 goto cdev_add_err;
1521
1522 sdp->cdev = cdev;
1523 if (sg_sysfs_valid) {
1524 struct device *sg_class_member;
1525
1526 sg_class_member = device_create(&sg_sysfs_class, cl_dev->parent,
1527 MKDEV(SCSI_GENERIC_MAJOR,
1528 sdp->index),
1529 sdp, "%s", sdp->name);
1530 if (IS_ERR(sg_class_member)) {
1531 pr_err("%s: device_create failed\n", __func__);
1532 error = PTR_ERR(sg_class_member);
1533 goto cdev_add_err;
1534 }
1535 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1536 &sg_class_member->kobj, "generic");
1537 if (error)
1538 pr_err("%s: unable to make symlink 'generic' back "
1539 "to sg%d\n", __func__, sdp->index);
1540 } else
1541 pr_warn("%s: sg_sys Invalid\n", __func__);
1542
1543 sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1544 "type %d\n", sdp->index, scsidp->type);
1545
1546 dev_set_drvdata(cl_dev, sdp);
1547
1548 return 0;
1549
1550cdev_add_err:
1551 write_lock_irqsave(&sg_index_lock, iflags);
1552 idr_remove(&sg_index_idr, sdp->index);
1553 write_unlock_irqrestore(&sg_index_lock, iflags);
1554 kfree(sdp);
1555
1556out:
1557 if (cdev)
1558 cdev_del(cdev);
1559 blk_put_queue(scsidp->request_queue);
1560 return error;
1561}
1562
1563static void
1564sg_device_destroy(struct kref *kref)
1565{
1566 struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1567 struct request_queue *q = sdp->device->request_queue;
1568 unsigned long flags;
1569
1570 /* CAUTION! Note that the device can still be found via idr_find()
1571 * even though the refcount is 0. Therefore, do idr_remove() BEFORE
1572 * any other cleanup.
1573 */
1574
1575 blk_trace_remove(q);
1576 blk_put_queue(q);
1577
1578 write_lock_irqsave(&sg_index_lock, flags);
1579 idr_remove(&sg_index_idr, sdp->index);
1580 write_unlock_irqrestore(&sg_index_lock, flags);
1581
1582 SCSI_LOG_TIMEOUT(3,
1583 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1584
1585 kfree(sdp);
1586}
1587
1588static void
1589sg_remove_device(struct device *cl_dev)
1590{
1591 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1592 Sg_device *sdp = dev_get_drvdata(cl_dev);
1593 unsigned long iflags;
1594 Sg_fd *sfp;
1595 int val;
1596
1597 if (!sdp)
1598 return;
1599 /* want sdp->detaching non-zero as soon as possible */
1600 val = atomic_inc_return(&sdp->detaching);
1601 if (val > 1)
1602 return; /* only want to do following once per device */
1603
1604 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1605 "%s\n", __func__));
1606
1607 read_lock_irqsave(&sdp->sfd_lock, iflags);
1608 list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1609 wake_up_interruptible_all(&sfp->read_wait);
1610 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1611 }
1612 wake_up_interruptible_all(&sdp->open_wait);
1613 read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1614
1615 sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1616 device_destroy(&sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1617 cdev_del(sdp->cdev);
1618 sdp->cdev = NULL;
1619
1620 kref_put(&sdp->d_ref, sg_device_destroy);
1621}
1622
1623module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1624module_param_named(def_reserved_size, def_reserved_size, int,
1625 S_IRUGO | S_IWUSR);
1626module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1627
1628MODULE_AUTHOR("Douglas Gilbert");
1629MODULE_DESCRIPTION("SCSI generic (sg) driver");
1630MODULE_LICENSE("GPL");
1631MODULE_VERSION(SG_VERSION_STR);
1632MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1633
1634MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1635 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1636MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1637MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1638
1639#ifdef CONFIG_SYSCTL
1640#include <linux/sysctl.h>
1641
1642static struct ctl_table sg_sysctls[] = {
1643 {
1644 .procname = "sg-big-buff",
1645 .data = &sg_big_buff,
1646 .maxlen = sizeof(int),
1647 .mode = 0444,
1648 .proc_handler = proc_dointvec,
1649 },
1650};
1651
1652static struct ctl_table_header *hdr;
1653static void register_sg_sysctls(void)
1654{
1655 if (!hdr)
1656 hdr = register_sysctl("kernel", sg_sysctls);
1657}
1658
1659static void unregister_sg_sysctls(void)
1660{
1661 if (hdr)
1662 unregister_sysctl_table(hdr);
1663}
1664#else
1665#define register_sg_sysctls() do { } while (0)
1666#define unregister_sg_sysctls() do { } while (0)
1667#endif /* CONFIG_SYSCTL */
1668
1669static int __init
1670init_sg(void)
1671{
1672 int rc;
1673
1674 if (scatter_elem_sz < PAGE_SIZE) {
1675 scatter_elem_sz = PAGE_SIZE;
1676 scatter_elem_sz_prev = scatter_elem_sz;
1677 }
1678 if (def_reserved_size >= 0)
1679 sg_big_buff = def_reserved_size;
1680 else
1681 def_reserved_size = sg_big_buff;
1682
1683 rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1684 SG_MAX_DEVS, "sg");
1685 if (rc)
1686 return rc;
1687 rc = class_register(&sg_sysfs_class);
1688 if (rc)
1689 goto err_out;
1690 sg_sysfs_valid = 1;
1691 rc = scsi_register_interface(&sg_interface);
1692 if (0 == rc) {
1693#ifdef CONFIG_SCSI_PROC_FS
1694 sg_proc_init();
1695#endif /* CONFIG_SCSI_PROC_FS */
1696 return 0;
1697 }
1698 class_unregister(&sg_sysfs_class);
1699 register_sg_sysctls();
1700err_out:
1701 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1702 return rc;
1703}
1704
1705static void __exit
1706exit_sg(void)
1707{
1708 unregister_sg_sysctls();
1709#ifdef CONFIG_SCSI_PROC_FS
1710 remove_proc_subtree("scsi/sg", NULL);
1711#endif /* CONFIG_SCSI_PROC_FS */
1712 scsi_unregister_interface(&sg_interface);
1713 class_unregister(&sg_sysfs_class);
1714 sg_sysfs_valid = 0;
1715 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1716 SG_MAX_DEVS);
1717 idr_destroy(&sg_index_idr);
1718}
1719
1720static int
1721sg_start_req(Sg_request *srp, unsigned char *cmd)
1722{
1723 int res;
1724 struct request *rq;
1725 Sg_fd *sfp = srp->parentfp;
1726 sg_io_hdr_t *hp = &srp->header;
1727 int dxfer_len = (int) hp->dxfer_len;
1728 int dxfer_dir = hp->dxfer_direction;
1729 unsigned int iov_count = hp->iovec_count;
1730 Sg_scatter_hold *req_schp = &srp->data;
1731 Sg_scatter_hold *rsv_schp = &sfp->reserve;
1732 struct request_queue *q = sfp->parentdp->device->request_queue;
1733 struct rq_map_data *md, map_data;
1734 int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? ITER_SOURCE : ITER_DEST;
1735 struct scsi_cmnd *scmd;
1736
1737 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1738 "sg_start_req: dxfer_len=%d\n",
1739 dxfer_len));
1740
1741 /*
1742 * NOTE
1743 *
1744 * With scsi-mq enabled, there are a fixed number of preallocated
1745 * requests equal in number to shost->can_queue. If all of the
1746 * preallocated requests are already in use, then scsi_alloc_request()
1747 * will sleep until an active command completes, freeing up a request.
1748 * Although waiting in an asynchronous interface is less than ideal, we
1749 * do not want to use BLK_MQ_REQ_NOWAIT here because userspace might
1750 * not expect an EWOULDBLOCK from this condition.
1751 */
1752 rq = scsi_alloc_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
1753 REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
1754 if (IS_ERR(rq))
1755 return PTR_ERR(rq);
1756 scmd = blk_mq_rq_to_pdu(rq);
1757
1758 if (hp->cmd_len > sizeof(scmd->cmnd)) {
1759 blk_mq_free_request(rq);
1760 return -EINVAL;
1761 }
1762
1763 memcpy(scmd->cmnd, cmd, hp->cmd_len);
1764 scmd->cmd_len = hp->cmd_len;
1765
1766 srp->rq = rq;
1767 rq->end_io_data = srp;
1768 scmd->allowed = SG_DEFAULT_RETRIES;
1769
1770 if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1771 return 0;
1772
1773 if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1774 dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1775 blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1776 md = NULL;
1777 else
1778 md = &map_data;
1779
1780 if (md) {
1781 mutex_lock(&sfp->f_mutex);
1782 if (dxfer_len <= rsv_schp->bufflen &&
1783 !sfp->res_in_use) {
1784 sfp->res_in_use = 1;
1785 sg_link_reserve(sfp, srp, dxfer_len);
1786 } else if (hp->flags & SG_FLAG_MMAP_IO) {
1787 res = -EBUSY; /* sfp->res_in_use == 1 */
1788 if (dxfer_len > rsv_schp->bufflen)
1789 res = -ENOMEM;
1790 mutex_unlock(&sfp->f_mutex);
1791 return res;
1792 } else {
1793 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1794 if (res) {
1795 mutex_unlock(&sfp->f_mutex);
1796 return res;
1797 }
1798 }
1799 mutex_unlock(&sfp->f_mutex);
1800
1801 md->pages = req_schp->pages;
1802 md->page_order = req_schp->page_order;
1803 md->nr_entries = req_schp->k_use_sg;
1804 md->offset = 0;
1805 md->null_mapped = hp->dxferp ? 0 : 1;
1806 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1807 md->from_user = 1;
1808 else
1809 md->from_user = 0;
1810 }
1811
1812 res = blk_rq_map_user_io(rq, md, hp->dxferp, hp->dxfer_len,
1813 GFP_ATOMIC, iov_count, iov_count, 1, rw);
1814 if (!res) {
1815 srp->bio = rq->bio;
1816
1817 if (!md) {
1818 req_schp->dio_in_use = 1;
1819 hp->info |= SG_INFO_DIRECT_IO;
1820 }
1821 }
1822 return res;
1823}
1824
1825static int
1826sg_finish_rem_req(Sg_request *srp)
1827{
1828 int ret = 0;
1829
1830 Sg_fd *sfp = srp->parentfp;
1831 Sg_scatter_hold *req_schp = &srp->data;
1832
1833 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1834 "sg_finish_rem_req: res_used=%d\n",
1835 (int) srp->res_used));
1836 if (srp->bio)
1837 ret = blk_rq_unmap_user(srp->bio);
1838
1839 if (srp->rq)
1840 blk_mq_free_request(srp->rq);
1841
1842 if (srp->res_used)
1843 sg_unlink_reserve(sfp, srp);
1844 else
1845 sg_remove_scat(sfp, req_schp);
1846
1847 return ret;
1848}
1849
1850static int
1851sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1852{
1853 int sg_bufflen = tablesize * sizeof(struct page *);
1854 gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1855
1856 schp->pages = kzalloc(sg_bufflen, gfp_flags);
1857 if (!schp->pages)
1858 return -ENOMEM;
1859 schp->sglist_len = sg_bufflen;
1860 return tablesize; /* number of scat_gath elements allocated */
1861}
1862
1863static int
1864sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1865{
1866 int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1867 int sg_tablesize = sfp->parentdp->sg_tablesize;
1868 int blk_size = buff_size, order;
1869 gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
1870
1871 if (blk_size < 0)
1872 return -EFAULT;
1873 if (0 == blk_size)
1874 ++blk_size; /* don't know why */
1875 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1876 blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1877 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1878 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1879 buff_size, blk_size));
1880
1881 /* N.B. ret_sz carried into this block ... */
1882 mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1883 if (mx_sc_elems < 0)
1884 return mx_sc_elems; /* most likely -ENOMEM */
1885
1886 num = scatter_elem_sz;
1887 if (unlikely(num != scatter_elem_sz_prev)) {
1888 if (num < PAGE_SIZE) {
1889 scatter_elem_sz = PAGE_SIZE;
1890 scatter_elem_sz_prev = PAGE_SIZE;
1891 } else
1892 scatter_elem_sz_prev = num;
1893 }
1894
1895 order = get_order(num);
1896retry:
1897 ret_sz = 1 << (PAGE_SHIFT + order);
1898
1899 for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1900 k++, rem_sz -= ret_sz) {
1901
1902 num = (rem_sz > scatter_elem_sz_prev) ?
1903 scatter_elem_sz_prev : rem_sz;
1904
1905 schp->pages[k] = alloc_pages(gfp_mask, order);
1906 if (!schp->pages[k])
1907 goto out;
1908
1909 if (num == scatter_elem_sz_prev) {
1910 if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1911 scatter_elem_sz = ret_sz;
1912 scatter_elem_sz_prev = ret_sz;
1913 }
1914 }
1915
1916 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1917 "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1918 k, num, ret_sz));
1919 } /* end of for loop */
1920
1921 schp->page_order = order;
1922 schp->k_use_sg = k;
1923 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1924 "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1925 k, rem_sz));
1926
1927 schp->bufflen = blk_size;
1928 if (rem_sz > 0) /* must have failed */
1929 return -ENOMEM;
1930 return 0;
1931out:
1932 for (i = 0; i < k; i++)
1933 __free_pages(schp->pages[i], order);
1934
1935 if (--order >= 0)
1936 goto retry;
1937
1938 return -ENOMEM;
1939}
1940
1941static void
1942sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1943{
1944 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1945 "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1946 if (schp->pages && schp->sglist_len > 0) {
1947 if (!schp->dio_in_use) {
1948 int k;
1949
1950 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1951 SCSI_LOG_TIMEOUT(5,
1952 sg_printk(KERN_INFO, sfp->parentdp,
1953 "sg_remove_scat: k=%d, pg=0x%p\n",
1954 k, schp->pages[k]));
1955 __free_pages(schp->pages[k], schp->page_order);
1956 }
1957
1958 kfree(schp->pages);
1959 }
1960 }
1961 memset(schp, 0, sizeof (*schp));
1962}
1963
1964static int
1965sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1966{
1967 Sg_scatter_hold *schp = &srp->data;
1968 int k, num;
1969
1970 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1971 "sg_read_oxfer: num_read_xfer=%d\n",
1972 num_read_xfer));
1973 if ((!outp) || (num_read_xfer <= 0))
1974 return 0;
1975
1976 num = 1 << (PAGE_SHIFT + schp->page_order);
1977 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1978 if (num > num_read_xfer) {
1979 if (copy_to_user(outp, page_address(schp->pages[k]),
1980 num_read_xfer))
1981 return -EFAULT;
1982 break;
1983 } else {
1984 if (copy_to_user(outp, page_address(schp->pages[k]),
1985 num))
1986 return -EFAULT;
1987 num_read_xfer -= num;
1988 if (num_read_xfer <= 0)
1989 break;
1990 outp += num;
1991 }
1992 }
1993
1994 return 0;
1995}
1996
1997static void
1998sg_build_reserve(Sg_fd * sfp, int req_size)
1999{
2000 Sg_scatter_hold *schp = &sfp->reserve;
2001
2002 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2003 "sg_build_reserve: req_size=%d\n", req_size));
2004 do {
2005 if (req_size < PAGE_SIZE)
2006 req_size = PAGE_SIZE;
2007 if (0 == sg_build_indirect(schp, sfp, req_size))
2008 return;
2009 else
2010 sg_remove_scat(sfp, schp);
2011 req_size >>= 1; /* divide by 2 */
2012 } while (req_size > (PAGE_SIZE / 2));
2013}
2014
2015static void
2016sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2017{
2018 Sg_scatter_hold *req_schp = &srp->data;
2019 Sg_scatter_hold *rsv_schp = &sfp->reserve;
2020 int k, num, rem;
2021
2022 srp->res_used = 1;
2023 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2024 "sg_link_reserve: size=%d\n", size));
2025 rem = size;
2026
2027 num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
2028 for (k = 0; k < rsv_schp->k_use_sg; k++) {
2029 if (rem <= num) {
2030 req_schp->k_use_sg = k + 1;
2031 req_schp->sglist_len = rsv_schp->sglist_len;
2032 req_schp->pages = rsv_schp->pages;
2033
2034 req_schp->bufflen = size;
2035 req_schp->page_order = rsv_schp->page_order;
2036 break;
2037 } else
2038 rem -= num;
2039 }
2040
2041 if (k >= rsv_schp->k_use_sg)
2042 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2043 "sg_link_reserve: BAD size\n"));
2044}
2045
2046static void
2047sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2048{
2049 Sg_scatter_hold *req_schp = &srp->data;
2050
2051 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2052 "sg_unlink_reserve: req->k_use_sg=%d\n",
2053 (int) req_schp->k_use_sg));
2054 req_schp->k_use_sg = 0;
2055 req_schp->bufflen = 0;
2056 req_schp->pages = NULL;
2057 req_schp->page_order = 0;
2058 req_schp->sglist_len = 0;
2059 srp->res_used = 0;
2060 /* Called without mutex lock to avoid deadlock */
2061 sfp->res_in_use = 0;
2062}
2063
2064static Sg_request *
2065sg_get_rq_mark(Sg_fd * sfp, int pack_id, bool *busy)
2066{
2067 Sg_request *resp;
2068 unsigned long iflags;
2069
2070 *busy = false;
2071 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2072 list_for_each_entry(resp, &sfp->rq_list, entry) {
2073 /* look for requests that are not SG_IO owned */
2074 if ((!resp->sg_io_owned) &&
2075 ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2076 switch (resp->done) {
2077 case 0: /* request active */
2078 *busy = true;
2079 break;
2080 case 1: /* request done; response ready to return */
2081 resp->done = 2; /* guard against other readers */
2082 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2083 return resp;
2084 case 2: /* response already being returned */
2085 break;
2086 }
2087 }
2088 }
2089 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2090 return NULL;
2091}
2092
2093/* always adds to end of list */
2094static Sg_request *
2095sg_add_request(Sg_fd * sfp)
2096{
2097 int k;
2098 unsigned long iflags;
2099 Sg_request *rp = sfp->req_arr;
2100
2101 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2102 if (!list_empty(&sfp->rq_list)) {
2103 if (!sfp->cmd_q)
2104 goto out_unlock;
2105
2106 for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2107 if (!rp->parentfp)
2108 break;
2109 }
2110 if (k >= SG_MAX_QUEUE)
2111 goto out_unlock;
2112 }
2113 memset(rp, 0, sizeof (Sg_request));
2114 rp->parentfp = sfp;
2115 rp->header.duration = jiffies_to_msecs(jiffies);
2116 list_add_tail(&rp->entry, &sfp->rq_list);
2117 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2118 return rp;
2119out_unlock:
2120 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2121 return NULL;
2122}
2123
2124/* Return of 1 for found; 0 for not found */
2125static int
2126sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2127{
2128 unsigned long iflags;
2129 int res = 0;
2130
2131 if (!sfp || !srp || list_empty(&sfp->rq_list))
2132 return res;
2133 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2134 if (!list_empty(&srp->entry)) {
2135 list_del(&srp->entry);
2136 srp->parentfp = NULL;
2137 res = 1;
2138 }
2139 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2140
2141 /*
2142 * If the device is detaching, wakeup any readers in case we just
2143 * removed the last response, which would leave nothing for them to
2144 * return other than -ENODEV.
2145 */
2146 if (unlikely(atomic_read(&sfp->parentdp->detaching)))
2147 wake_up_interruptible_all(&sfp->read_wait);
2148
2149 return res;
2150}
2151
2152static Sg_fd *
2153sg_add_sfp(Sg_device * sdp)
2154{
2155 Sg_fd *sfp;
2156 unsigned long iflags;
2157 int bufflen;
2158
2159 sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2160 if (!sfp)
2161 return ERR_PTR(-ENOMEM);
2162
2163 init_waitqueue_head(&sfp->read_wait);
2164 rwlock_init(&sfp->rq_list_lock);
2165 INIT_LIST_HEAD(&sfp->rq_list);
2166 kref_init(&sfp->f_ref);
2167 mutex_init(&sfp->f_mutex);
2168 sfp->timeout = SG_DEFAULT_TIMEOUT;
2169 sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2170 sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2171 sfp->cmd_q = SG_DEF_COMMAND_Q;
2172 sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2173 sfp->parentdp = sdp;
2174 write_lock_irqsave(&sdp->sfd_lock, iflags);
2175 if (atomic_read(&sdp->detaching)) {
2176 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2177 kfree(sfp);
2178 return ERR_PTR(-ENODEV);
2179 }
2180 list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2181 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2182 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2183 "sg_add_sfp: sfp=0x%p\n", sfp));
2184 if (unlikely(sg_big_buff != def_reserved_size))
2185 sg_big_buff = def_reserved_size;
2186
2187 bufflen = min_t(int, sg_big_buff,
2188 max_sectors_bytes(sdp->device->request_queue));
2189 sg_build_reserve(sfp, bufflen);
2190 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2191 "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2192 sfp->reserve.bufflen,
2193 sfp->reserve.k_use_sg));
2194
2195 kref_get(&sdp->d_ref);
2196 __module_get(THIS_MODULE);
2197 return sfp;
2198}
2199
2200static void
2201sg_remove_sfp_usercontext(struct work_struct *work)
2202{
2203 struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2204 struct sg_device *sdp = sfp->parentdp;
2205 struct scsi_device *device = sdp->device;
2206 Sg_request *srp;
2207 unsigned long iflags;
2208
2209 /* Cleanup any responses which were never read(). */
2210 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2211 while (!list_empty(&sfp->rq_list)) {
2212 srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2213 sg_finish_rem_req(srp);
2214 list_del(&srp->entry);
2215 srp->parentfp = NULL;
2216 }
2217 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2218
2219 if (sfp->reserve.bufflen > 0) {
2220 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2221 "sg_remove_sfp: bufflen=%d, k_use_sg=%d\n",
2222 (int) sfp->reserve.bufflen,
2223 (int) sfp->reserve.k_use_sg));
2224 sg_remove_scat(sfp, &sfp->reserve);
2225 }
2226
2227 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2228 "sg_remove_sfp: sfp=0x%p\n", sfp));
2229 kfree(sfp);
2230
2231 kref_put(&sdp->d_ref, sg_device_destroy);
2232 scsi_device_put(device);
2233 module_put(THIS_MODULE);
2234}
2235
2236static void
2237sg_remove_sfp(struct kref *kref)
2238{
2239 struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2240 struct sg_device *sdp = sfp->parentdp;
2241 unsigned long iflags;
2242
2243 write_lock_irqsave(&sdp->sfd_lock, iflags);
2244 list_del(&sfp->sfd_siblings);
2245 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2246
2247 INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2248 schedule_work(&sfp->ew.work);
2249}
2250
2251#ifdef CONFIG_SCSI_PROC_FS
2252static int
2253sg_idr_max_id(int id, void *p, void *data)
2254{
2255 int *k = data;
2256
2257 if (*k < id)
2258 *k = id;
2259
2260 return 0;
2261}
2262
2263static int
2264sg_last_dev(void)
2265{
2266 int k = -1;
2267 unsigned long iflags;
2268
2269 read_lock_irqsave(&sg_index_lock, iflags);
2270 idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2271 read_unlock_irqrestore(&sg_index_lock, iflags);
2272 return k + 1; /* origin 1 */
2273}
2274#endif
2275
2276/* must be called with sg_index_lock held */
2277static Sg_device *sg_lookup_dev(int dev)
2278{
2279 return idr_find(&sg_index_idr, dev);
2280}
2281
2282static Sg_device *
2283sg_get_dev(int dev)
2284{
2285 struct sg_device *sdp;
2286 unsigned long flags;
2287
2288 read_lock_irqsave(&sg_index_lock, flags);
2289 sdp = sg_lookup_dev(dev);
2290 if (!sdp)
2291 sdp = ERR_PTR(-ENXIO);
2292 else if (atomic_read(&sdp->detaching)) {
2293 /* If sdp->detaching, then the refcount may already be 0, in
2294 * which case it would be a bug to do kref_get().
2295 */
2296 sdp = ERR_PTR(-ENODEV);
2297 } else
2298 kref_get(&sdp->d_ref);
2299 read_unlock_irqrestore(&sg_index_lock, flags);
2300
2301 return sdp;
2302}
2303
2304#ifdef CONFIG_SCSI_PROC_FS
2305static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2306
2307static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2308static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2309 size_t count, loff_t *off);
2310static const struct proc_ops adio_proc_ops = {
2311 .proc_open = sg_proc_single_open_adio,
2312 .proc_read = seq_read,
2313 .proc_lseek = seq_lseek,
2314 .proc_write = sg_proc_write_adio,
2315 .proc_release = single_release,
2316};
2317
2318static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2319static ssize_t sg_proc_write_dressz(struct file *filp,
2320 const char __user *buffer, size_t count, loff_t *off);
2321static const struct proc_ops dressz_proc_ops = {
2322 .proc_open = sg_proc_single_open_dressz,
2323 .proc_read = seq_read,
2324 .proc_lseek = seq_lseek,
2325 .proc_write = sg_proc_write_dressz,
2326 .proc_release = single_release,
2327};
2328
2329static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2330static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2331static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2332static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2333static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2334static void dev_seq_stop(struct seq_file *s, void *v);
2335static const struct seq_operations dev_seq_ops = {
2336 .start = dev_seq_start,
2337 .next = dev_seq_next,
2338 .stop = dev_seq_stop,
2339 .show = sg_proc_seq_show_dev,
2340};
2341
2342static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2343static const struct seq_operations devstrs_seq_ops = {
2344 .start = dev_seq_start,
2345 .next = dev_seq_next,
2346 .stop = dev_seq_stop,
2347 .show = sg_proc_seq_show_devstrs,
2348};
2349
2350static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2351static const struct seq_operations debug_seq_ops = {
2352 .start = dev_seq_start,
2353 .next = dev_seq_next,
2354 .stop = dev_seq_stop,
2355 .show = sg_proc_seq_show_debug,
2356};
2357
2358static int
2359sg_proc_init(void)
2360{
2361 struct proc_dir_entry *p;
2362
2363 p = proc_mkdir("scsi/sg", NULL);
2364 if (!p)
2365 return 1;
2366
2367 proc_create("allow_dio", S_IRUGO | S_IWUSR, p, &adio_proc_ops);
2368 proc_create_seq("debug", S_IRUGO, p, &debug_seq_ops);
2369 proc_create("def_reserved_size", S_IRUGO | S_IWUSR, p, &dressz_proc_ops);
2370 proc_create_single("device_hdr", S_IRUGO, p, sg_proc_seq_show_devhdr);
2371 proc_create_seq("devices", S_IRUGO, p, &dev_seq_ops);
2372 proc_create_seq("device_strs", S_IRUGO, p, &devstrs_seq_ops);
2373 proc_create_single("version", S_IRUGO, p, sg_proc_seq_show_version);
2374 return 0;
2375}
2376
2377
2378static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2379{
2380 seq_printf(s, "%d\n", *((int *)s->private));
2381 return 0;
2382}
2383
2384static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2385{
2386 return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2387}
2388
2389static ssize_t
2390sg_proc_write_adio(struct file *filp, const char __user *buffer,
2391 size_t count, loff_t *off)
2392{
2393 int err;
2394 unsigned long num;
2395
2396 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2397 return -EACCES;
2398 err = kstrtoul_from_user(buffer, count, 0, &num);
2399 if (err)
2400 return err;
2401 sg_allow_dio = num ? 1 : 0;
2402 return count;
2403}
2404
2405static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2406{
2407 return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2408}
2409
2410static ssize_t
2411sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2412 size_t count, loff_t *off)
2413{
2414 int err;
2415 unsigned long k = ULONG_MAX;
2416
2417 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2418 return -EACCES;
2419
2420 err = kstrtoul_from_user(buffer, count, 0, &k);
2421 if (err)
2422 return err;
2423 if (k <= 1048576) { /* limit "big buff" to 1 MB */
2424 sg_big_buff = k;
2425 return count;
2426 }
2427 return -ERANGE;
2428}
2429
2430static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2431{
2432 seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2433 sg_version_date);
2434 return 0;
2435}
2436
2437static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2438{
2439 seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2440 return 0;
2441}
2442
2443struct sg_proc_deviter {
2444 loff_t index;
2445 size_t max;
2446};
2447
2448static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2449{
2450 struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2451
2452 s->private = it;
2453 if (! it)
2454 return NULL;
2455
2456 it->index = *pos;
2457 it->max = sg_last_dev();
2458 if (it->index >= it->max)
2459 return NULL;
2460 return it;
2461}
2462
2463static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2464{
2465 struct sg_proc_deviter * it = s->private;
2466
2467 *pos = ++it->index;
2468 return (it->index < it->max) ? it : NULL;
2469}
2470
2471static void dev_seq_stop(struct seq_file *s, void *v)
2472{
2473 kfree(s->private);
2474}
2475
2476static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2477{
2478 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2479 Sg_device *sdp;
2480 struct scsi_device *scsidp;
2481 unsigned long iflags;
2482
2483 read_lock_irqsave(&sg_index_lock, iflags);
2484 sdp = it ? sg_lookup_dev(it->index) : NULL;
2485 if ((NULL == sdp) || (NULL == sdp->device) ||
2486 (atomic_read(&sdp->detaching)))
2487 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2488 else {
2489 scsidp = sdp->device;
2490 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2491 scsidp->host->host_no, scsidp->channel,
2492 scsidp->id, scsidp->lun, (int) scsidp->type,
2493 1,
2494 (int) scsidp->queue_depth,
2495 (int) scsi_device_busy(scsidp),
2496 (int) scsi_device_online(scsidp));
2497 }
2498 read_unlock_irqrestore(&sg_index_lock, iflags);
2499 return 0;
2500}
2501
2502static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2503{
2504 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2505 Sg_device *sdp;
2506 struct scsi_device *scsidp;
2507 unsigned long iflags;
2508
2509 read_lock_irqsave(&sg_index_lock, iflags);
2510 sdp = it ? sg_lookup_dev(it->index) : NULL;
2511 scsidp = sdp ? sdp->device : NULL;
2512 if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2513 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2514 scsidp->vendor, scsidp->model, scsidp->rev);
2515 else
2516 seq_puts(s, "<no active device>\n");
2517 read_unlock_irqrestore(&sg_index_lock, iflags);
2518 return 0;
2519}
2520
2521/* must be called while holding sg_index_lock */
2522static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2523{
2524 int k, new_interface, blen, usg;
2525 Sg_request *srp;
2526 Sg_fd *fp;
2527 const sg_io_hdr_t *hp;
2528 const char * cp;
2529 unsigned int ms;
2530
2531 k = 0;
2532 list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2533 k++;
2534 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2535 seq_printf(s, " FD(%d): timeout=%dms bufflen=%d "
2536 "(res)sgat=%d low_dma=%d\n", k,
2537 jiffies_to_msecs(fp->timeout),
2538 fp->reserve.bufflen,
2539 (int) fp->reserve.k_use_sg, 0);
2540 seq_printf(s, " cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2541 (int) fp->cmd_q, (int) fp->force_packid,
2542 (int) fp->keep_orphan);
2543 list_for_each_entry(srp, &fp->rq_list, entry) {
2544 hp = &srp->header;
2545 new_interface = (hp->interface_id == '\0') ? 0 : 1;
2546 if (srp->res_used) {
2547 if (new_interface &&
2548 (SG_FLAG_MMAP_IO & hp->flags))
2549 cp = " mmap>> ";
2550 else
2551 cp = " rb>> ";
2552 } else {
2553 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2554 cp = " dio>> ";
2555 else
2556 cp = " ";
2557 }
2558 seq_puts(s, cp);
2559 blen = srp->data.bufflen;
2560 usg = srp->data.k_use_sg;
2561 seq_puts(s, srp->done ?
2562 ((1 == srp->done) ? "rcv:" : "fin:")
2563 : "act:");
2564 seq_printf(s, " id=%d blen=%d",
2565 srp->header.pack_id, blen);
2566 if (srp->done)
2567 seq_printf(s, " dur=%d", hp->duration);
2568 else {
2569 ms = jiffies_to_msecs(jiffies);
2570 seq_printf(s, " t_o/elap=%d/%d",
2571 (new_interface ? hp->timeout :
2572 jiffies_to_msecs(fp->timeout)),
2573 (ms > hp->duration ? ms - hp->duration : 0));
2574 }
2575 seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2576 (int) srp->data.cmd_opcode);
2577 }
2578 if (list_empty(&fp->rq_list))
2579 seq_puts(s, " No requests active\n");
2580 read_unlock(&fp->rq_list_lock);
2581 }
2582}
2583
2584static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2585{
2586 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2587 Sg_device *sdp;
2588 unsigned long iflags;
2589
2590 if (it && (0 == it->index))
2591 seq_printf(s, "max_active_device=%d def_reserved_size=%d\n",
2592 (int)it->max, sg_big_buff);
2593
2594 read_lock_irqsave(&sg_index_lock, iflags);
2595 sdp = it ? sg_lookup_dev(it->index) : NULL;
2596 if (NULL == sdp)
2597 goto skip;
2598 read_lock(&sdp->sfd_lock);
2599 if (!list_empty(&sdp->sfds)) {
2600 seq_printf(s, " >>> device=%s ", sdp->name);
2601 if (atomic_read(&sdp->detaching))
2602 seq_puts(s, "detaching pending close ");
2603 else if (sdp->device) {
2604 struct scsi_device *scsidp = sdp->device;
2605
2606 seq_printf(s, "%d:%d:%d:%llu em=%d",
2607 scsidp->host->host_no,
2608 scsidp->channel, scsidp->id,
2609 scsidp->lun,
2610 scsidp->host->hostt->emulated);
2611 }
2612 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2613 sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2614 sg_proc_debug_helper(s, sdp);
2615 }
2616 read_unlock(&sdp->sfd_lock);
2617skip:
2618 read_unlock_irqrestore(&sg_index_lock, iflags);
2619 return 0;
2620}
2621
2622#endif /* CONFIG_SCSI_PROC_FS */
2623
2624module_init(init_sg);
2625module_exit(exit_sg);