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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * History:
4 * Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
5 * to allow user process control of SCSI devices.
6 * Development Sponsored by Killy Corp. NY NY
7 *
8 * Original driver (sg.c):
9 * Copyright (C) 1992 Lawrence Foard
10 * Version 2 and 3 extensions to driver:
11 * Copyright (C) 1998 - 2014 Douglas Gilbert
12 */
13
14static int sg_version_num = 30536; /* 2 digits for each component */
15#define SG_VERSION_STR "3.5.36"
16
17/*
18 * D. P. Gilbert (dgilbert@interlog.com), notes:
19 * - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
20 * the kernel/module needs to be built with CONFIG_SCSI_LOGGING
21 * (otherwise the macros compile to empty statements).
22 *
23 */
24#include <linux/module.h>
25
26#include <linux/fs.h>
27#include <linux/kernel.h>
28#include <linux/sched.h>
29#include <linux/string.h>
30#include <linux/mm.h>
31#include <linux/errno.h>
32#include <linux/mtio.h>
33#include <linux/ioctl.h>
34#include <linux/major.h>
35#include <linux/slab.h>
36#include <linux/fcntl.h>
37#include <linux/init.h>
38#include <linux/poll.h>
39#include <linux/moduleparam.h>
40#include <linux/cdev.h>
41#include <linux/idr.h>
42#include <linux/seq_file.h>
43#include <linux/blkdev.h>
44#include <linux/delay.h>
45#include <linux/blktrace_api.h>
46#include <linux/mutex.h>
47#include <linux/atomic.h>
48#include <linux/ratelimit.h>
49#include <linux/uio.h>
50#include <linux/cred.h> /* for sg_check_file_access() */
51
52#include <scsi/scsi.h>
53#include <scsi/scsi_cmnd.h>
54#include <scsi/scsi_dbg.h>
55#include <scsi/scsi_device.h>
56#include <scsi/scsi_driver.h>
57#include <scsi/scsi_eh.h>
58#include <scsi/scsi_host.h>
59#include <scsi/scsi_ioctl.h>
60#include <scsi/scsi_tcq.h>
61#include <scsi/sg.h>
62
63#include "scsi_logging.h"
64
65#ifdef CONFIG_SCSI_PROC_FS
66#include <linux/proc_fs.h>
67static char *sg_version_date = "20140603";
68
69static int sg_proc_init(void);
70#endif
71
72#define SG_ALLOW_DIO_DEF 0
73
74#define SG_MAX_DEVS (1 << MINORBITS)
75
76/* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
77 * of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater
78 * than 16 bytes are "variable length" whose length is a multiple of 4
79 */
80#define SG_MAX_CDB_SIZE 252
81
82#define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
83
84static int sg_big_buff = SG_DEF_RESERVED_SIZE;
85/* N.B. This variable is readable and writeable via
86 /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
87 of this size (or less if there is not enough memory) will be reserved
88 for use by this file descriptor. [Deprecated usage: this variable is also
89 readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
90 the kernel (i.e. it is not a module).] */
91static int def_reserved_size = -1; /* picks up init parameter */
92static int sg_allow_dio = SG_ALLOW_DIO_DEF;
93
94static int scatter_elem_sz = SG_SCATTER_SZ;
95static int scatter_elem_sz_prev = SG_SCATTER_SZ;
96
97#define SG_SECTOR_SZ 512
98
99static int sg_add_device(struct device *);
100static void sg_remove_device(struct device *);
101
102static DEFINE_IDR(sg_index_idr);
103static DEFINE_RWLOCK(sg_index_lock); /* Also used to lock
104 file descriptor list for device */
105
106static struct class_interface sg_interface = {
107 .add_dev = sg_add_device,
108 .remove_dev = sg_remove_device,
109};
110
111typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
112 unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
113 unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
114 unsigned bufflen; /* Size of (aggregate) data buffer */
115 struct page **pages;
116 int page_order;
117 char dio_in_use; /* 0->indirect IO (or mmap), 1->dio */
118 unsigned char cmd_opcode; /* first byte of command */
119} Sg_scatter_hold;
120
121struct sg_device; /* forward declarations */
122struct sg_fd;
123
124typedef struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */
125 struct list_head entry; /* list entry */
126 struct sg_fd *parentfp; /* NULL -> not in use */
127 Sg_scatter_hold data; /* hold buffer, perhaps scatter list */
128 sg_io_hdr_t header; /* scsi command+info, see <scsi/sg.h> */
129 unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
130 char res_used; /* 1 -> using reserve buffer, 0 -> not ... */
131 char orphan; /* 1 -> drop on sight, 0 -> normal */
132 char sg_io_owned; /* 1 -> packet belongs to SG_IO */
133 /* done protected by rq_list_lock */
134 char done; /* 0->before bh, 1->before read, 2->read */
135 struct request *rq;
136 struct bio *bio;
137 struct execute_work ew;
138} Sg_request;
139
140typedef struct sg_fd { /* holds the state of a file descriptor */
141 struct list_head sfd_siblings; /* protected by device's sfd_lock */
142 struct sg_device *parentdp; /* owning device */
143 wait_queue_head_t read_wait; /* queue read until command done */
144 rwlock_t rq_list_lock; /* protect access to list in req_arr */
145 struct mutex f_mutex; /* protect against changes in this fd */
146 int timeout; /* defaults to SG_DEFAULT_TIMEOUT */
147 int timeout_user; /* defaults to SG_DEFAULT_TIMEOUT_USER */
148 Sg_scatter_hold reserve; /* buffer held for this file descriptor */
149 struct list_head rq_list; /* head of request list */
150 struct fasync_struct *async_qp; /* used by asynchronous notification */
151 Sg_request req_arr[SG_MAX_QUEUE]; /* used as singly-linked list */
152 char force_packid; /* 1 -> pack_id input to read(), 0 -> ignored */
153 char cmd_q; /* 1 -> allow command queuing, 0 -> don't */
154 unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */
155 char keep_orphan; /* 0 -> drop orphan (def), 1 -> keep for read() */
156 char mmap_called; /* 0 -> mmap() never called on this fd */
157 char res_in_use; /* 1 -> 'reserve' array in use */
158 struct kref f_ref;
159 struct execute_work ew;
160} Sg_fd;
161
162typedef struct sg_device { /* holds the state of each scsi generic device */
163 struct scsi_device *device;
164 wait_queue_head_t open_wait; /* queue open() when O_EXCL present */
165 struct mutex open_rel_lock; /* held when in open() or release() */
166 int sg_tablesize; /* adapter's max scatter-gather table size */
167 u32 index; /* device index number */
168 struct list_head sfds;
169 rwlock_t sfd_lock; /* protect access to sfd list */
170 atomic_t detaching; /* 0->device usable, 1->device detaching */
171 bool exclude; /* 1->open(O_EXCL) succeeded and is active */
172 int open_cnt; /* count of opens (perhaps < num(sfds) ) */
173 char sgdebug; /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
174 char name[DISK_NAME_LEN];
175 struct cdev * cdev; /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
176 struct kref d_ref;
177} Sg_device;
178
179/* tasklet or soft irq callback */
180static enum rq_end_io_ret sg_rq_end_io(struct request *rq, blk_status_t status);
181static int sg_start_req(Sg_request *srp, unsigned char *cmd);
182static int sg_finish_rem_req(Sg_request * srp);
183static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
184static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
185 Sg_request * srp);
186static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
187 const char __user *buf, size_t count, int blocking,
188 int read_only, int sg_io_owned, Sg_request **o_srp);
189static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
190 unsigned char *cmnd, int timeout, int blocking);
191static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
192static void sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp);
193static void sg_build_reserve(Sg_fd * sfp, int req_size);
194static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
195static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
196static Sg_fd *sg_add_sfp(Sg_device * sdp);
197static void sg_remove_sfp(struct kref *);
198static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id, bool *busy);
199static Sg_request *sg_add_request(Sg_fd * sfp);
200static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
201static Sg_device *sg_get_dev(int dev);
202static void sg_device_destroy(struct kref *kref);
203
204#define SZ_SG_HEADER sizeof(struct sg_header)
205#define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
206#define SZ_SG_IOVEC sizeof(sg_iovec_t)
207#define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
208
209#define sg_printk(prefix, sdp, fmt, a...) \
210 sdev_prefix_printk(prefix, (sdp)->device, (sdp)->name, fmt, ##a)
211
212/*
213 * The SCSI interfaces that use read() and write() as an asynchronous variant of
214 * ioctl(..., SG_IO, ...) are fundamentally unsafe, since there are lots of ways
215 * to trigger read() and write() calls from various contexts with elevated
216 * privileges. This can lead to kernel memory corruption (e.g. if these
217 * interfaces are called through splice()) and privilege escalation inside
218 * userspace (e.g. if a process with access to such a device passes a file
219 * descriptor to a SUID binary as stdin/stdout/stderr).
220 *
221 * This function provides protection for the legacy API by restricting the
222 * calling context.
223 */
224static int sg_check_file_access(struct file *filp, const char *caller)
225{
226 if (filp->f_cred != current_real_cred()) {
227 pr_err_once("%s: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
228 caller, task_tgid_vnr(current), current->comm);
229 return -EPERM;
230 }
231 return 0;
232}
233
234static int sg_allow_access(struct file *filp, unsigned char *cmd)
235{
236 struct sg_fd *sfp = filp->private_data;
237
238 if (sfp->parentdp->device->type == TYPE_SCANNER)
239 return 0;
240 if (!scsi_cmd_allowed(cmd, filp->f_mode & FMODE_WRITE))
241 return -EPERM;
242 return 0;
243}
244
245static int
246open_wait(Sg_device *sdp, int flags)
247{
248 int retval = 0;
249
250 if (flags & O_EXCL) {
251 while (sdp->open_cnt > 0) {
252 mutex_unlock(&sdp->open_rel_lock);
253 retval = wait_event_interruptible(sdp->open_wait,
254 (atomic_read(&sdp->detaching) ||
255 !sdp->open_cnt));
256 mutex_lock(&sdp->open_rel_lock);
257
258 if (retval) /* -ERESTARTSYS */
259 return retval;
260 if (atomic_read(&sdp->detaching))
261 return -ENODEV;
262 }
263 } else {
264 while (sdp->exclude) {
265 mutex_unlock(&sdp->open_rel_lock);
266 retval = wait_event_interruptible(sdp->open_wait,
267 (atomic_read(&sdp->detaching) ||
268 !sdp->exclude));
269 mutex_lock(&sdp->open_rel_lock);
270
271 if (retval) /* -ERESTARTSYS */
272 return retval;
273 if (atomic_read(&sdp->detaching))
274 return -ENODEV;
275 }
276 }
277
278 return retval;
279}
280
281/* Returns 0 on success, else a negated errno value */
282static int
283sg_open(struct inode *inode, struct file *filp)
284{
285 int dev = iminor(inode);
286 int flags = filp->f_flags;
287 struct request_queue *q;
288 Sg_device *sdp;
289 Sg_fd *sfp;
290 int retval;
291
292 nonseekable_open(inode, filp);
293 if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
294 return -EPERM; /* Can't lock it with read only access */
295 sdp = sg_get_dev(dev);
296 if (IS_ERR(sdp))
297 return PTR_ERR(sdp);
298
299 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
300 "sg_open: flags=0x%x\n", flags));
301
302 /* This driver's module count bumped by fops_get in <linux/fs.h> */
303 /* Prevent the device driver from vanishing while we sleep */
304 retval = scsi_device_get(sdp->device);
305 if (retval)
306 goto sg_put;
307
308 retval = scsi_autopm_get_device(sdp->device);
309 if (retval)
310 goto sdp_put;
311
312 /* scsi_block_when_processing_errors() may block so bypass
313 * check if O_NONBLOCK. Permits SCSI commands to be issued
314 * during error recovery. Tread carefully. */
315 if (!((flags & O_NONBLOCK) ||
316 scsi_block_when_processing_errors(sdp->device))) {
317 retval = -ENXIO;
318 /* we are in error recovery for this device */
319 goto error_out;
320 }
321
322 mutex_lock(&sdp->open_rel_lock);
323 if (flags & O_NONBLOCK) {
324 if (flags & O_EXCL) {
325 if (sdp->open_cnt > 0) {
326 retval = -EBUSY;
327 goto error_mutex_locked;
328 }
329 } else {
330 if (sdp->exclude) {
331 retval = -EBUSY;
332 goto error_mutex_locked;
333 }
334 }
335 } else {
336 retval = open_wait(sdp, flags);
337 if (retval) /* -ERESTARTSYS or -ENODEV */
338 goto error_mutex_locked;
339 }
340
341 /* N.B. at this point we are holding the open_rel_lock */
342 if (flags & O_EXCL)
343 sdp->exclude = true;
344
345 if (sdp->open_cnt < 1) { /* no existing opens */
346 sdp->sgdebug = 0;
347 q = sdp->device->request_queue;
348 sdp->sg_tablesize = queue_max_segments(q);
349 }
350 sfp = sg_add_sfp(sdp);
351 if (IS_ERR(sfp)) {
352 retval = PTR_ERR(sfp);
353 goto out_undo;
354 }
355
356 filp->private_data = sfp;
357 sdp->open_cnt++;
358 mutex_unlock(&sdp->open_rel_lock);
359
360 retval = 0;
361sg_put:
362 kref_put(&sdp->d_ref, sg_device_destroy);
363 return retval;
364
365out_undo:
366 if (flags & O_EXCL) {
367 sdp->exclude = false; /* undo if error */
368 wake_up_interruptible(&sdp->open_wait);
369 }
370error_mutex_locked:
371 mutex_unlock(&sdp->open_rel_lock);
372error_out:
373 scsi_autopm_put_device(sdp->device);
374sdp_put:
375 scsi_device_put(sdp->device);
376 goto sg_put;
377}
378
379/* Release resources associated with a successful sg_open()
380 * Returns 0 on success, else a negated errno value */
381static int
382sg_release(struct inode *inode, struct file *filp)
383{
384 Sg_device *sdp;
385 Sg_fd *sfp;
386
387 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
388 return -ENXIO;
389 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
390
391 mutex_lock(&sdp->open_rel_lock);
392 scsi_autopm_put_device(sdp->device);
393 kref_put(&sfp->f_ref, sg_remove_sfp);
394 sdp->open_cnt--;
395
396 /* possibly many open()s waiting on exlude clearing, start many;
397 * only open(O_EXCL)s wait on 0==open_cnt so only start one */
398 if (sdp->exclude) {
399 sdp->exclude = false;
400 wake_up_interruptible_all(&sdp->open_wait);
401 } else if (0 == sdp->open_cnt) {
402 wake_up_interruptible(&sdp->open_wait);
403 }
404 mutex_unlock(&sdp->open_rel_lock);
405 return 0;
406}
407
408static int get_sg_io_pack_id(int *pack_id, void __user *buf, size_t count)
409{
410 struct sg_header __user *old_hdr = buf;
411 int reply_len;
412
413 if (count >= SZ_SG_HEADER) {
414 /* negative reply_len means v3 format, otherwise v1/v2 */
415 if (get_user(reply_len, &old_hdr->reply_len))
416 return -EFAULT;
417
418 if (reply_len >= 0)
419 return get_user(*pack_id, &old_hdr->pack_id);
420
421 if (in_compat_syscall() &&
422 count >= sizeof(struct compat_sg_io_hdr)) {
423 struct compat_sg_io_hdr __user *hp = buf;
424
425 return get_user(*pack_id, &hp->pack_id);
426 }
427
428 if (count >= sizeof(struct sg_io_hdr)) {
429 struct sg_io_hdr __user *hp = buf;
430
431 return get_user(*pack_id, &hp->pack_id);
432 }
433 }
434
435 /* no valid header was passed, so ignore the pack_id */
436 *pack_id = -1;
437 return 0;
438}
439
440static ssize_t
441sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
442{
443 Sg_device *sdp;
444 Sg_fd *sfp;
445 Sg_request *srp;
446 int req_pack_id = -1;
447 bool busy;
448 sg_io_hdr_t *hp;
449 struct sg_header *old_hdr;
450 int retval;
451
452 /*
453 * This could cause a response to be stranded. Close the associated
454 * file descriptor to free up any resources being held.
455 */
456 retval = sg_check_file_access(filp, __func__);
457 if (retval)
458 return retval;
459
460 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
461 return -ENXIO;
462 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
463 "sg_read: count=%d\n", (int) count));
464
465 if (sfp->force_packid)
466 retval = get_sg_io_pack_id(&req_pack_id, buf, count);
467 if (retval)
468 return retval;
469
470 srp = sg_get_rq_mark(sfp, req_pack_id, &busy);
471 if (!srp) { /* now wait on packet to arrive */
472 if (filp->f_flags & O_NONBLOCK)
473 return -EAGAIN;
474 retval = wait_event_interruptible(sfp->read_wait,
475 ((srp = sg_get_rq_mark(sfp, req_pack_id, &busy)) ||
476 (!busy && atomic_read(&sdp->detaching))));
477 if (!srp)
478 /* signal or detaching */
479 return retval ? retval : -ENODEV;
480 }
481 if (srp->header.interface_id != '\0')
482 return sg_new_read(sfp, buf, count, srp);
483
484 hp = &srp->header;
485 old_hdr = kzalloc(SZ_SG_HEADER, GFP_KERNEL);
486 if (!old_hdr)
487 return -ENOMEM;
488
489 old_hdr->reply_len = (int) hp->timeout;
490 old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
491 old_hdr->pack_id = hp->pack_id;
492 old_hdr->twelve_byte =
493 ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
494 old_hdr->target_status = hp->masked_status;
495 old_hdr->host_status = hp->host_status;
496 old_hdr->driver_status = hp->driver_status;
497 if ((CHECK_CONDITION & hp->masked_status) ||
498 (srp->sense_b[0] & 0x70) == 0x70) {
499 old_hdr->driver_status = DRIVER_SENSE;
500 memcpy(old_hdr->sense_buffer, srp->sense_b,
501 sizeof (old_hdr->sense_buffer));
502 }
503 switch (hp->host_status) {
504 /* This setup of 'result' is for backward compatibility and is best
505 ignored by the user who should use target, host + driver status */
506 case DID_OK:
507 case DID_PASSTHROUGH:
508 case DID_SOFT_ERROR:
509 old_hdr->result = 0;
510 break;
511 case DID_NO_CONNECT:
512 case DID_BUS_BUSY:
513 case DID_TIME_OUT:
514 old_hdr->result = EBUSY;
515 break;
516 case DID_BAD_TARGET:
517 case DID_ABORT:
518 case DID_PARITY:
519 case DID_RESET:
520 case DID_BAD_INTR:
521 old_hdr->result = EIO;
522 break;
523 case DID_ERROR:
524 old_hdr->result = (srp->sense_b[0] == 0 &&
525 hp->masked_status == GOOD) ? 0 : EIO;
526 break;
527 default:
528 old_hdr->result = EIO;
529 break;
530 }
531
532 /* Now copy the result back to the user buffer. */
533 if (count >= SZ_SG_HEADER) {
534 if (copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
535 retval = -EFAULT;
536 goto free_old_hdr;
537 }
538 buf += SZ_SG_HEADER;
539 if (count > old_hdr->reply_len)
540 count = old_hdr->reply_len;
541 if (count > SZ_SG_HEADER) {
542 if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
543 retval = -EFAULT;
544 goto free_old_hdr;
545 }
546 }
547 } else
548 count = (old_hdr->result == 0) ? 0 : -EIO;
549 sg_finish_rem_req(srp);
550 sg_remove_request(sfp, srp);
551 retval = count;
552free_old_hdr:
553 kfree(old_hdr);
554 return retval;
555}
556
557static ssize_t
558sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
559{
560 sg_io_hdr_t *hp = &srp->header;
561 int err = 0, err2;
562 int len;
563
564 if (in_compat_syscall()) {
565 if (count < sizeof(struct compat_sg_io_hdr)) {
566 err = -EINVAL;
567 goto err_out;
568 }
569 } else if (count < SZ_SG_IO_HDR) {
570 err = -EINVAL;
571 goto err_out;
572 }
573 hp->sb_len_wr = 0;
574 if ((hp->mx_sb_len > 0) && hp->sbp) {
575 if ((CHECK_CONDITION & hp->masked_status) ||
576 (srp->sense_b[0] & 0x70) == 0x70) {
577 int sb_len = SCSI_SENSE_BUFFERSIZE;
578 sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
579 len = 8 + (int) srp->sense_b[7]; /* Additional sense length field */
580 len = (len > sb_len) ? sb_len : len;
581 if (copy_to_user(hp->sbp, srp->sense_b, len)) {
582 err = -EFAULT;
583 goto err_out;
584 }
585 hp->driver_status = DRIVER_SENSE;
586 hp->sb_len_wr = len;
587 }
588 }
589 if (hp->masked_status || hp->host_status || hp->driver_status)
590 hp->info |= SG_INFO_CHECK;
591 err = put_sg_io_hdr(hp, buf);
592err_out:
593 err2 = sg_finish_rem_req(srp);
594 sg_remove_request(sfp, srp);
595 return err ? : err2 ? : count;
596}
597
598static ssize_t
599sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
600{
601 int mxsize, cmd_size, k;
602 int input_size, blocking;
603 unsigned char opcode;
604 Sg_device *sdp;
605 Sg_fd *sfp;
606 Sg_request *srp;
607 struct sg_header old_hdr;
608 sg_io_hdr_t *hp;
609 unsigned char cmnd[SG_MAX_CDB_SIZE];
610 int retval;
611
612 retval = sg_check_file_access(filp, __func__);
613 if (retval)
614 return retval;
615
616 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
617 return -ENXIO;
618 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
619 "sg_write: count=%d\n", (int) count));
620 if (atomic_read(&sdp->detaching))
621 return -ENODEV;
622 if (!((filp->f_flags & O_NONBLOCK) ||
623 scsi_block_when_processing_errors(sdp->device)))
624 return -ENXIO;
625
626 if (count < SZ_SG_HEADER)
627 return -EIO;
628 if (copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
629 return -EFAULT;
630 blocking = !(filp->f_flags & O_NONBLOCK);
631 if (old_hdr.reply_len < 0)
632 return sg_new_write(sfp, filp, buf, count,
633 blocking, 0, 0, NULL);
634 if (count < (SZ_SG_HEADER + 6))
635 return -EIO; /* The minimum scsi command length is 6 bytes. */
636
637 buf += SZ_SG_HEADER;
638 if (get_user(opcode, buf))
639 return -EFAULT;
640
641 if (!(srp = sg_add_request(sfp))) {
642 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
643 "sg_write: queue full\n"));
644 return -EDOM;
645 }
646 mutex_lock(&sfp->f_mutex);
647 if (sfp->next_cmd_len > 0) {
648 cmd_size = sfp->next_cmd_len;
649 sfp->next_cmd_len = 0; /* reset so only this write() effected */
650 } else {
651 cmd_size = COMMAND_SIZE(opcode); /* based on SCSI command group */
652 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
653 cmd_size = 12;
654 }
655 mutex_unlock(&sfp->f_mutex);
656 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
657 "sg_write: scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
658/* Determine buffer size. */
659 input_size = count - cmd_size;
660 mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
661 mxsize -= SZ_SG_HEADER;
662 input_size -= SZ_SG_HEADER;
663 if (input_size < 0) {
664 sg_remove_request(sfp, srp);
665 return -EIO; /* User did not pass enough bytes for this command. */
666 }
667 hp = &srp->header;
668 hp->interface_id = '\0'; /* indicator of old interface tunnelled */
669 hp->cmd_len = (unsigned char) cmd_size;
670 hp->iovec_count = 0;
671 hp->mx_sb_len = 0;
672 if (input_size > 0)
673 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
674 SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
675 else
676 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
677 hp->dxfer_len = mxsize;
678 if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
679 (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
680 hp->dxferp = (char __user *)buf + cmd_size;
681 else
682 hp->dxferp = NULL;
683 hp->sbp = NULL;
684 hp->timeout = old_hdr.reply_len; /* structure abuse ... */
685 hp->flags = input_size; /* structure abuse ... */
686 hp->pack_id = old_hdr.pack_id;
687 hp->usr_ptr = NULL;
688 if (copy_from_user(cmnd, buf, cmd_size)) {
689 sg_remove_request(sfp, srp);
690 return -EFAULT;
691 }
692 /*
693 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
694 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
695 * is a non-zero input_size, so emit a warning.
696 */
697 if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
698 printk_ratelimited(KERN_WARNING
699 "sg_write: data in/out %d/%d bytes "
700 "for SCSI command 0x%x-- guessing "
701 "data in;\n program %s not setting "
702 "count and/or reply_len properly\n",
703 old_hdr.reply_len - (int)SZ_SG_HEADER,
704 input_size, (unsigned int) cmnd[0],
705 current->comm);
706 }
707 k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
708 return (k < 0) ? k : count;
709}
710
711static ssize_t
712sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
713 size_t count, int blocking, int read_only, int sg_io_owned,
714 Sg_request **o_srp)
715{
716 int k;
717 Sg_request *srp;
718 sg_io_hdr_t *hp;
719 unsigned char cmnd[SG_MAX_CDB_SIZE];
720 int timeout;
721 unsigned long ul_timeout;
722
723 if (count < SZ_SG_IO_HDR)
724 return -EINVAL;
725
726 sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
727 if (!(srp = sg_add_request(sfp))) {
728 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
729 "sg_new_write: queue full\n"));
730 return -EDOM;
731 }
732 srp->sg_io_owned = sg_io_owned;
733 hp = &srp->header;
734 if (get_sg_io_hdr(hp, buf)) {
735 sg_remove_request(sfp, srp);
736 return -EFAULT;
737 }
738 if (hp->interface_id != 'S') {
739 sg_remove_request(sfp, srp);
740 return -ENOSYS;
741 }
742 if (hp->flags & SG_FLAG_MMAP_IO) {
743 if (hp->dxfer_len > sfp->reserve.bufflen) {
744 sg_remove_request(sfp, srp);
745 return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
746 }
747 if (hp->flags & SG_FLAG_DIRECT_IO) {
748 sg_remove_request(sfp, srp);
749 return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
750 }
751 if (sfp->res_in_use) {
752 sg_remove_request(sfp, srp);
753 return -EBUSY; /* reserve buffer already being used */
754 }
755 }
756 ul_timeout = msecs_to_jiffies(srp->header.timeout);
757 timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
758 if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
759 sg_remove_request(sfp, srp);
760 return -EMSGSIZE;
761 }
762 if (copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
763 sg_remove_request(sfp, srp);
764 return -EFAULT;
765 }
766 if (read_only && sg_allow_access(file, cmnd)) {
767 sg_remove_request(sfp, srp);
768 return -EPERM;
769 }
770 k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
771 if (k < 0)
772 return k;
773 if (o_srp)
774 *o_srp = srp;
775 return count;
776}
777
778static int
779sg_common_write(Sg_fd * sfp, Sg_request * srp,
780 unsigned char *cmnd, int timeout, int blocking)
781{
782 int k, at_head;
783 Sg_device *sdp = sfp->parentdp;
784 sg_io_hdr_t *hp = &srp->header;
785
786 srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
787 hp->status = 0;
788 hp->masked_status = 0;
789 hp->msg_status = 0;
790 hp->info = 0;
791 hp->host_status = 0;
792 hp->driver_status = 0;
793 hp->resid = 0;
794 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
795 "sg_common_write: scsi opcode=0x%02x, cmd_size=%d\n",
796 (int) cmnd[0], (int) hp->cmd_len));
797
798 if (hp->dxfer_len >= SZ_256M) {
799 sg_remove_request(sfp, srp);
800 return -EINVAL;
801 }
802
803 k = sg_start_req(srp, cmnd);
804 if (k) {
805 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
806 "sg_common_write: start_req err=%d\n", k));
807 sg_finish_rem_req(srp);
808 sg_remove_request(sfp, srp);
809 return k; /* probably out of space --> ENOMEM */
810 }
811 if (atomic_read(&sdp->detaching)) {
812 if (srp->bio) {
813 blk_mq_free_request(srp->rq);
814 srp->rq = NULL;
815 }
816
817 sg_finish_rem_req(srp);
818 sg_remove_request(sfp, srp);
819 return -ENODEV;
820 }
821
822 hp->duration = jiffies_to_msecs(jiffies);
823 if (hp->interface_id != '\0' && /* v3 (or later) interface */
824 (SG_FLAG_Q_AT_TAIL & hp->flags))
825 at_head = 0;
826 else
827 at_head = 1;
828
829 srp->rq->timeout = timeout;
830 kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
831 srp->rq->end_io = sg_rq_end_io;
832 blk_execute_rq_nowait(srp->rq, at_head);
833 return 0;
834}
835
836static int srp_done(Sg_fd *sfp, Sg_request *srp)
837{
838 unsigned long flags;
839 int ret;
840
841 read_lock_irqsave(&sfp->rq_list_lock, flags);
842 ret = srp->done;
843 read_unlock_irqrestore(&sfp->rq_list_lock, flags);
844 return ret;
845}
846
847static int max_sectors_bytes(struct request_queue *q)
848{
849 unsigned int max_sectors = queue_max_sectors(q);
850
851 max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
852
853 return max_sectors << 9;
854}
855
856static void
857sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
858{
859 Sg_request *srp;
860 int val;
861 unsigned int ms;
862
863 val = 0;
864 list_for_each_entry(srp, &sfp->rq_list, entry) {
865 if (val >= SG_MAX_QUEUE)
866 break;
867 rinfo[val].req_state = srp->done + 1;
868 rinfo[val].problem =
869 srp->header.masked_status &
870 srp->header.host_status &
871 srp->header.driver_status;
872 if (srp->done)
873 rinfo[val].duration =
874 srp->header.duration;
875 else {
876 ms = jiffies_to_msecs(jiffies);
877 rinfo[val].duration =
878 (ms > srp->header.duration) ?
879 (ms - srp->header.duration) : 0;
880 }
881 rinfo[val].orphan = srp->orphan;
882 rinfo[val].sg_io_owned = srp->sg_io_owned;
883 rinfo[val].pack_id = srp->header.pack_id;
884 rinfo[val].usr_ptr = srp->header.usr_ptr;
885 val++;
886 }
887}
888
889#ifdef CONFIG_COMPAT
890struct compat_sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
891 char req_state;
892 char orphan;
893 char sg_io_owned;
894 char problem;
895 int pack_id;
896 compat_uptr_t usr_ptr;
897 unsigned int duration;
898 int unused;
899};
900
901static int put_compat_request_table(struct compat_sg_req_info __user *o,
902 struct sg_req_info *rinfo)
903{
904 int i;
905 for (i = 0; i < SG_MAX_QUEUE; i++) {
906 if (copy_to_user(o + i, rinfo + i, offsetof(sg_req_info_t, usr_ptr)) ||
907 put_user((uintptr_t)rinfo[i].usr_ptr, &o[i].usr_ptr) ||
908 put_user(rinfo[i].duration, &o[i].duration) ||
909 put_user(rinfo[i].unused, &o[i].unused))
910 return -EFAULT;
911 }
912 return 0;
913}
914#endif
915
916static long
917sg_ioctl_common(struct file *filp, Sg_device *sdp, Sg_fd *sfp,
918 unsigned int cmd_in, void __user *p)
919{
920 int __user *ip = p;
921 int result, val, read_only;
922 Sg_request *srp;
923 unsigned long iflags;
924
925 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
926 "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
927 read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
928
929 switch (cmd_in) {
930 case SG_IO:
931 if (atomic_read(&sdp->detaching))
932 return -ENODEV;
933 if (!scsi_block_when_processing_errors(sdp->device))
934 return -ENXIO;
935 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
936 1, read_only, 1, &srp);
937 if (result < 0)
938 return result;
939 result = wait_event_interruptible(sfp->read_wait,
940 srp_done(sfp, srp));
941 write_lock_irq(&sfp->rq_list_lock);
942 if (srp->done) {
943 srp->done = 2;
944 write_unlock_irq(&sfp->rq_list_lock);
945 result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
946 return (result < 0) ? result : 0;
947 }
948 srp->orphan = 1;
949 write_unlock_irq(&sfp->rq_list_lock);
950 return result; /* -ERESTARTSYS because signal hit process */
951 case SG_SET_TIMEOUT:
952 result = get_user(val, ip);
953 if (result)
954 return result;
955 if (val < 0)
956 return -EIO;
957 if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
958 val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
959 INT_MAX);
960 sfp->timeout_user = val;
961 sfp->timeout = mult_frac(val, HZ, USER_HZ);
962
963 return 0;
964 case SG_GET_TIMEOUT: /* N.B. User receives timeout as return value */
965 /* strange ..., for backward compatibility */
966 return sfp->timeout_user;
967 case SG_SET_FORCE_LOW_DMA:
968 /*
969 * N.B. This ioctl never worked properly, but failed to
970 * return an error value. So returning '0' to keep compability
971 * with legacy applications.
972 */
973 return 0;
974 case SG_GET_LOW_DMA:
975 return put_user(0, ip);
976 case SG_GET_SCSI_ID:
977 {
978 sg_scsi_id_t v;
979
980 if (atomic_read(&sdp->detaching))
981 return -ENODEV;
982 memset(&v, 0, sizeof(v));
983 v.host_no = sdp->device->host->host_no;
984 v.channel = sdp->device->channel;
985 v.scsi_id = sdp->device->id;
986 v.lun = sdp->device->lun;
987 v.scsi_type = sdp->device->type;
988 v.h_cmd_per_lun = sdp->device->host->cmd_per_lun;
989 v.d_queue_depth = sdp->device->queue_depth;
990 if (copy_to_user(p, &v, sizeof(sg_scsi_id_t)))
991 return -EFAULT;
992 return 0;
993 }
994 case SG_SET_FORCE_PACK_ID:
995 result = get_user(val, ip);
996 if (result)
997 return result;
998 sfp->force_packid = val ? 1 : 0;
999 return 0;
1000 case SG_GET_PACK_ID:
1001 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1002 list_for_each_entry(srp, &sfp->rq_list, entry) {
1003 if ((1 == srp->done) && (!srp->sg_io_owned)) {
1004 read_unlock_irqrestore(&sfp->rq_list_lock,
1005 iflags);
1006 return put_user(srp->header.pack_id, ip);
1007 }
1008 }
1009 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1010 return put_user(-1, ip);
1011 case SG_GET_NUM_WAITING:
1012 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1013 val = 0;
1014 list_for_each_entry(srp, &sfp->rq_list, entry) {
1015 if ((1 == srp->done) && (!srp->sg_io_owned))
1016 ++val;
1017 }
1018 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1019 return put_user(val, ip);
1020 case SG_GET_SG_TABLESIZE:
1021 return put_user(sdp->sg_tablesize, ip);
1022 case SG_SET_RESERVED_SIZE:
1023 result = get_user(val, ip);
1024 if (result)
1025 return result;
1026 if (val < 0)
1027 return -EINVAL;
1028 val = min_t(int, val,
1029 max_sectors_bytes(sdp->device->request_queue));
1030 mutex_lock(&sfp->f_mutex);
1031 if (val != sfp->reserve.bufflen) {
1032 if (sfp->mmap_called ||
1033 sfp->res_in_use) {
1034 mutex_unlock(&sfp->f_mutex);
1035 return -EBUSY;
1036 }
1037
1038 sg_remove_scat(sfp, &sfp->reserve);
1039 sg_build_reserve(sfp, val);
1040 }
1041 mutex_unlock(&sfp->f_mutex);
1042 return 0;
1043 case SG_GET_RESERVED_SIZE:
1044 val = min_t(int, sfp->reserve.bufflen,
1045 max_sectors_bytes(sdp->device->request_queue));
1046 return put_user(val, ip);
1047 case SG_SET_COMMAND_Q:
1048 result = get_user(val, ip);
1049 if (result)
1050 return result;
1051 sfp->cmd_q = val ? 1 : 0;
1052 return 0;
1053 case SG_GET_COMMAND_Q:
1054 return put_user((int) sfp->cmd_q, ip);
1055 case SG_SET_KEEP_ORPHAN:
1056 result = get_user(val, ip);
1057 if (result)
1058 return result;
1059 sfp->keep_orphan = val;
1060 return 0;
1061 case SG_GET_KEEP_ORPHAN:
1062 return put_user((int) sfp->keep_orphan, ip);
1063 case SG_NEXT_CMD_LEN:
1064 result = get_user(val, ip);
1065 if (result)
1066 return result;
1067 if (val > SG_MAX_CDB_SIZE)
1068 return -ENOMEM;
1069 sfp->next_cmd_len = (val > 0) ? val : 0;
1070 return 0;
1071 case SG_GET_VERSION_NUM:
1072 return put_user(sg_version_num, ip);
1073 case SG_GET_ACCESS_COUNT:
1074 /* faked - we don't have a real access count anymore */
1075 val = (sdp->device ? 1 : 0);
1076 return put_user(val, ip);
1077 case SG_GET_REQUEST_TABLE:
1078 {
1079 sg_req_info_t *rinfo;
1080
1081 rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
1082 GFP_KERNEL);
1083 if (!rinfo)
1084 return -ENOMEM;
1085 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1086 sg_fill_request_table(sfp, rinfo);
1087 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1088 #ifdef CONFIG_COMPAT
1089 if (in_compat_syscall())
1090 result = put_compat_request_table(p, rinfo);
1091 else
1092 #endif
1093 result = copy_to_user(p, rinfo,
1094 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1095 result = result ? -EFAULT : 0;
1096 kfree(rinfo);
1097 return result;
1098 }
1099 case SG_EMULATED_HOST:
1100 if (atomic_read(&sdp->detaching))
1101 return -ENODEV;
1102 return put_user(sdp->device->host->hostt->emulated, ip);
1103 case SCSI_IOCTL_SEND_COMMAND:
1104 if (atomic_read(&sdp->detaching))
1105 return -ENODEV;
1106 return scsi_ioctl(sdp->device, filp->f_mode & FMODE_WRITE,
1107 cmd_in, p);
1108 case SG_SET_DEBUG:
1109 result = get_user(val, ip);
1110 if (result)
1111 return result;
1112 sdp->sgdebug = (char) val;
1113 return 0;
1114 case BLKSECTGET:
1115 return put_user(max_sectors_bytes(sdp->device->request_queue),
1116 ip);
1117 case BLKTRACESETUP:
1118 return blk_trace_setup(sdp->device->request_queue, sdp->name,
1119 MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1120 NULL, p);
1121 case BLKTRACESTART:
1122 return blk_trace_startstop(sdp->device->request_queue, 1);
1123 case BLKTRACESTOP:
1124 return blk_trace_startstop(sdp->device->request_queue, 0);
1125 case BLKTRACETEARDOWN:
1126 return blk_trace_remove(sdp->device->request_queue);
1127 case SCSI_IOCTL_GET_IDLUN:
1128 case SCSI_IOCTL_GET_BUS_NUMBER:
1129 case SCSI_IOCTL_PROBE_HOST:
1130 case SG_GET_TRANSFORM:
1131 case SG_SCSI_RESET:
1132 if (atomic_read(&sdp->detaching))
1133 return -ENODEV;
1134 break;
1135 default:
1136 if (read_only)
1137 return -EPERM; /* don't know so take safe approach */
1138 break;
1139 }
1140
1141 result = scsi_ioctl_block_when_processing_errors(sdp->device,
1142 cmd_in, filp->f_flags & O_NDELAY);
1143 if (result)
1144 return result;
1145
1146 return -ENOIOCTLCMD;
1147}
1148
1149static long
1150sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1151{
1152 void __user *p = (void __user *)arg;
1153 Sg_device *sdp;
1154 Sg_fd *sfp;
1155 int ret;
1156
1157 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1158 return -ENXIO;
1159
1160 ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
1161 if (ret != -ENOIOCTLCMD)
1162 return ret;
1163 return scsi_ioctl(sdp->device, filp->f_mode & FMODE_WRITE, cmd_in, p);
1164}
1165
1166static __poll_t
1167sg_poll(struct file *filp, poll_table * wait)
1168{
1169 __poll_t res = 0;
1170 Sg_device *sdp;
1171 Sg_fd *sfp;
1172 Sg_request *srp;
1173 int count = 0;
1174 unsigned long iflags;
1175
1176 sfp = filp->private_data;
1177 if (!sfp)
1178 return EPOLLERR;
1179 sdp = sfp->parentdp;
1180 if (!sdp)
1181 return EPOLLERR;
1182 poll_wait(filp, &sfp->read_wait, wait);
1183 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1184 list_for_each_entry(srp, &sfp->rq_list, entry) {
1185 /* if any read waiting, flag it */
1186 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1187 res = EPOLLIN | EPOLLRDNORM;
1188 ++count;
1189 }
1190 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1191
1192 if (atomic_read(&sdp->detaching))
1193 res |= EPOLLHUP;
1194 else if (!sfp->cmd_q) {
1195 if (0 == count)
1196 res |= EPOLLOUT | EPOLLWRNORM;
1197 } else if (count < SG_MAX_QUEUE)
1198 res |= EPOLLOUT | EPOLLWRNORM;
1199 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1200 "sg_poll: res=0x%x\n", (__force u32) res));
1201 return res;
1202}
1203
1204static int
1205sg_fasync(int fd, struct file *filp, int mode)
1206{
1207 Sg_device *sdp;
1208 Sg_fd *sfp;
1209
1210 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1211 return -ENXIO;
1212 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1213 "sg_fasync: mode=%d\n", mode));
1214
1215 return fasync_helper(fd, filp, mode, &sfp->async_qp);
1216}
1217
1218static vm_fault_t
1219sg_vma_fault(struct vm_fault *vmf)
1220{
1221 struct vm_area_struct *vma = vmf->vma;
1222 Sg_fd *sfp;
1223 unsigned long offset, len, sa;
1224 Sg_scatter_hold *rsv_schp;
1225 int k, length;
1226
1227 if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1228 return VM_FAULT_SIGBUS;
1229 rsv_schp = &sfp->reserve;
1230 offset = vmf->pgoff << PAGE_SHIFT;
1231 if (offset >= rsv_schp->bufflen)
1232 return VM_FAULT_SIGBUS;
1233 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1234 "sg_vma_fault: offset=%lu, scatg=%d\n",
1235 offset, rsv_schp->k_use_sg));
1236 sa = vma->vm_start;
1237 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1238 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1239 len = vma->vm_end - sa;
1240 len = (len < length) ? len : length;
1241 if (offset < len) {
1242 struct page *page = nth_page(rsv_schp->pages[k],
1243 offset >> PAGE_SHIFT);
1244 get_page(page); /* increment page count */
1245 vmf->page = page;
1246 return 0; /* success */
1247 }
1248 sa += len;
1249 offset -= len;
1250 }
1251
1252 return VM_FAULT_SIGBUS;
1253}
1254
1255static const struct vm_operations_struct sg_mmap_vm_ops = {
1256 .fault = sg_vma_fault,
1257};
1258
1259static int
1260sg_mmap(struct file *filp, struct vm_area_struct *vma)
1261{
1262 Sg_fd *sfp;
1263 unsigned long req_sz, len, sa;
1264 Sg_scatter_hold *rsv_schp;
1265 int k, length;
1266 int ret = 0;
1267
1268 if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1269 return -ENXIO;
1270 req_sz = vma->vm_end - vma->vm_start;
1271 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1272 "sg_mmap starting, vm_start=%p, len=%d\n",
1273 (void *) vma->vm_start, (int) req_sz));
1274 if (vma->vm_pgoff)
1275 return -EINVAL; /* want no offset */
1276 rsv_schp = &sfp->reserve;
1277 mutex_lock(&sfp->f_mutex);
1278 if (req_sz > rsv_schp->bufflen) {
1279 ret = -ENOMEM; /* cannot map more than reserved buffer */
1280 goto out;
1281 }
1282
1283 sa = vma->vm_start;
1284 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1285 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1286 len = vma->vm_end - sa;
1287 len = (len < length) ? len : length;
1288 sa += len;
1289 }
1290
1291 sfp->mmap_called = 1;
1292 vm_flags_set(vma, VM_IO | VM_DONTEXPAND | VM_DONTDUMP);
1293 vma->vm_private_data = sfp;
1294 vma->vm_ops = &sg_mmap_vm_ops;
1295out:
1296 mutex_unlock(&sfp->f_mutex);
1297 return ret;
1298}
1299
1300static void
1301sg_rq_end_io_usercontext(struct work_struct *work)
1302{
1303 struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1304 struct sg_fd *sfp = srp->parentfp;
1305
1306 sg_finish_rem_req(srp);
1307 sg_remove_request(sfp, srp);
1308 kref_put(&sfp->f_ref, sg_remove_sfp);
1309}
1310
1311/*
1312 * This function is a "bottom half" handler that is called by the mid
1313 * level when a command is completed (or has failed).
1314 */
1315static enum rq_end_io_ret
1316sg_rq_end_io(struct request *rq, blk_status_t status)
1317{
1318 struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
1319 struct sg_request *srp = rq->end_io_data;
1320 Sg_device *sdp;
1321 Sg_fd *sfp;
1322 unsigned long iflags;
1323 unsigned int ms;
1324 char *sense;
1325 int result, resid, done = 1;
1326
1327 if (WARN_ON(srp->done != 0))
1328 return RQ_END_IO_NONE;
1329
1330 sfp = srp->parentfp;
1331 if (WARN_ON(sfp == NULL))
1332 return RQ_END_IO_NONE;
1333
1334 sdp = sfp->parentdp;
1335 if (unlikely(atomic_read(&sdp->detaching)))
1336 pr_info("%s: device detaching\n", __func__);
1337
1338 sense = scmd->sense_buffer;
1339 result = scmd->result;
1340 resid = scmd->resid_len;
1341
1342 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1343 "sg_cmd_done: pack_id=%d, res=0x%x\n",
1344 srp->header.pack_id, result));
1345 srp->header.resid = resid;
1346 ms = jiffies_to_msecs(jiffies);
1347 srp->header.duration = (ms > srp->header.duration) ?
1348 (ms - srp->header.duration) : 0;
1349 if (0 != result) {
1350 struct scsi_sense_hdr sshdr;
1351
1352 srp->header.status = 0xff & result;
1353 srp->header.masked_status = sg_status_byte(result);
1354 srp->header.msg_status = COMMAND_COMPLETE;
1355 srp->header.host_status = host_byte(result);
1356 srp->header.driver_status = driver_byte(result);
1357 if ((sdp->sgdebug > 0) &&
1358 ((CHECK_CONDITION == srp->header.masked_status) ||
1359 (COMMAND_TERMINATED == srp->header.masked_status)))
1360 __scsi_print_sense(sdp->device, __func__, sense,
1361 SCSI_SENSE_BUFFERSIZE);
1362
1363 /* Following if statement is a patch supplied by Eric Youngdale */
1364 if (driver_byte(result) != 0
1365 && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1366 && !scsi_sense_is_deferred(&sshdr)
1367 && sshdr.sense_key == UNIT_ATTENTION
1368 && sdp->device->removable) {
1369 /* Detected possible disc change. Set the bit - this */
1370 /* may be used if there are filesystems using this device */
1371 sdp->device->changed = 1;
1372 }
1373 }
1374
1375 if (scmd->sense_len)
1376 memcpy(srp->sense_b, scmd->sense_buffer, SCSI_SENSE_BUFFERSIZE);
1377
1378 /* Rely on write phase to clean out srp status values, so no "else" */
1379
1380 /*
1381 * Free the request as soon as it is complete so that its resources
1382 * can be reused without waiting for userspace to read() the
1383 * result. But keep the associated bio (if any) around until
1384 * blk_rq_unmap_user() can be called from user context.
1385 */
1386 srp->rq = NULL;
1387 blk_mq_free_request(rq);
1388
1389 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1390 if (unlikely(srp->orphan)) {
1391 if (sfp->keep_orphan)
1392 srp->sg_io_owned = 0;
1393 else
1394 done = 0;
1395 }
1396 srp->done = done;
1397 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1398
1399 if (likely(done)) {
1400 /* Now wake up any sg_read() that is waiting for this
1401 * packet.
1402 */
1403 wake_up_interruptible(&sfp->read_wait);
1404 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1405 kref_put(&sfp->f_ref, sg_remove_sfp);
1406 } else {
1407 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1408 schedule_work(&srp->ew.work);
1409 }
1410 return RQ_END_IO_NONE;
1411}
1412
1413static const struct file_operations sg_fops = {
1414 .owner = THIS_MODULE,
1415 .read = sg_read,
1416 .write = sg_write,
1417 .poll = sg_poll,
1418 .unlocked_ioctl = sg_ioctl,
1419 .compat_ioctl = compat_ptr_ioctl,
1420 .open = sg_open,
1421 .mmap = sg_mmap,
1422 .release = sg_release,
1423 .fasync = sg_fasync,
1424 .llseek = no_llseek,
1425};
1426
1427static struct class *sg_sysfs_class;
1428
1429static int sg_sysfs_valid = 0;
1430
1431static Sg_device *
1432sg_alloc(struct scsi_device *scsidp)
1433{
1434 struct request_queue *q = scsidp->request_queue;
1435 Sg_device *sdp;
1436 unsigned long iflags;
1437 int error;
1438 u32 k;
1439
1440 sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1441 if (!sdp) {
1442 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1443 "failure\n", __func__);
1444 return ERR_PTR(-ENOMEM);
1445 }
1446
1447 idr_preload(GFP_KERNEL);
1448 write_lock_irqsave(&sg_index_lock, iflags);
1449
1450 error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1451 if (error < 0) {
1452 if (error == -ENOSPC) {
1453 sdev_printk(KERN_WARNING, scsidp,
1454 "Unable to attach sg device type=%d, minor number exceeds %d\n",
1455 scsidp->type, SG_MAX_DEVS - 1);
1456 error = -ENODEV;
1457 } else {
1458 sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1459 "allocation Sg_device failure: %d\n",
1460 __func__, error);
1461 }
1462 goto out_unlock;
1463 }
1464 k = error;
1465
1466 SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1467 "sg_alloc: dev=%d \n", k));
1468 sprintf(sdp->name, "sg%d", k);
1469 sdp->device = scsidp;
1470 mutex_init(&sdp->open_rel_lock);
1471 INIT_LIST_HEAD(&sdp->sfds);
1472 init_waitqueue_head(&sdp->open_wait);
1473 atomic_set(&sdp->detaching, 0);
1474 rwlock_init(&sdp->sfd_lock);
1475 sdp->sg_tablesize = queue_max_segments(q);
1476 sdp->index = k;
1477 kref_init(&sdp->d_ref);
1478 error = 0;
1479
1480out_unlock:
1481 write_unlock_irqrestore(&sg_index_lock, iflags);
1482 idr_preload_end();
1483
1484 if (error) {
1485 kfree(sdp);
1486 return ERR_PTR(error);
1487 }
1488 return sdp;
1489}
1490
1491static int
1492sg_add_device(struct device *cl_dev)
1493{
1494 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1495 Sg_device *sdp = NULL;
1496 struct cdev * cdev = NULL;
1497 int error;
1498 unsigned long iflags;
1499
1500 if (!blk_get_queue(scsidp->request_queue)) {
1501 pr_warn("%s: get scsi_device queue failed\n", __func__);
1502 return -ENODEV;
1503 }
1504
1505 error = -ENOMEM;
1506 cdev = cdev_alloc();
1507 if (!cdev) {
1508 pr_warn("%s: cdev_alloc failed\n", __func__);
1509 goto out;
1510 }
1511 cdev->owner = THIS_MODULE;
1512 cdev->ops = &sg_fops;
1513
1514 sdp = sg_alloc(scsidp);
1515 if (IS_ERR(sdp)) {
1516 pr_warn("%s: sg_alloc failed\n", __func__);
1517 error = PTR_ERR(sdp);
1518 goto out;
1519 }
1520
1521 error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1522 if (error)
1523 goto cdev_add_err;
1524
1525 sdp->cdev = cdev;
1526 if (sg_sysfs_valid) {
1527 struct device *sg_class_member;
1528
1529 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1530 MKDEV(SCSI_GENERIC_MAJOR,
1531 sdp->index),
1532 sdp, "%s", sdp->name);
1533 if (IS_ERR(sg_class_member)) {
1534 pr_err("%s: device_create failed\n", __func__);
1535 error = PTR_ERR(sg_class_member);
1536 goto cdev_add_err;
1537 }
1538 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1539 &sg_class_member->kobj, "generic");
1540 if (error)
1541 pr_err("%s: unable to make symlink 'generic' back "
1542 "to sg%d\n", __func__, sdp->index);
1543 } else
1544 pr_warn("%s: sg_sys Invalid\n", __func__);
1545
1546 sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1547 "type %d\n", sdp->index, scsidp->type);
1548
1549 dev_set_drvdata(cl_dev, sdp);
1550
1551 return 0;
1552
1553cdev_add_err:
1554 write_lock_irqsave(&sg_index_lock, iflags);
1555 idr_remove(&sg_index_idr, sdp->index);
1556 write_unlock_irqrestore(&sg_index_lock, iflags);
1557 kfree(sdp);
1558
1559out:
1560 if (cdev)
1561 cdev_del(cdev);
1562 blk_put_queue(scsidp->request_queue);
1563 return error;
1564}
1565
1566static void
1567sg_device_destroy(struct kref *kref)
1568{
1569 struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1570 struct request_queue *q = sdp->device->request_queue;
1571 unsigned long flags;
1572
1573 /* CAUTION! Note that the device can still be found via idr_find()
1574 * even though the refcount is 0. Therefore, do idr_remove() BEFORE
1575 * any other cleanup.
1576 */
1577
1578 blk_trace_remove(q);
1579 blk_put_queue(q);
1580
1581 write_lock_irqsave(&sg_index_lock, flags);
1582 idr_remove(&sg_index_idr, sdp->index);
1583 write_unlock_irqrestore(&sg_index_lock, flags);
1584
1585 SCSI_LOG_TIMEOUT(3,
1586 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1587
1588 kfree(sdp);
1589}
1590
1591static void
1592sg_remove_device(struct device *cl_dev)
1593{
1594 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1595 Sg_device *sdp = dev_get_drvdata(cl_dev);
1596 unsigned long iflags;
1597 Sg_fd *sfp;
1598 int val;
1599
1600 if (!sdp)
1601 return;
1602 /* want sdp->detaching non-zero as soon as possible */
1603 val = atomic_inc_return(&sdp->detaching);
1604 if (val > 1)
1605 return; /* only want to do following once per device */
1606
1607 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1608 "%s\n", __func__));
1609
1610 read_lock_irqsave(&sdp->sfd_lock, iflags);
1611 list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1612 wake_up_interruptible_all(&sfp->read_wait);
1613 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1614 }
1615 wake_up_interruptible_all(&sdp->open_wait);
1616 read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1617
1618 sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1619 device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1620 cdev_del(sdp->cdev);
1621 sdp->cdev = NULL;
1622
1623 kref_put(&sdp->d_ref, sg_device_destroy);
1624}
1625
1626module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1627module_param_named(def_reserved_size, def_reserved_size, int,
1628 S_IRUGO | S_IWUSR);
1629module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1630
1631MODULE_AUTHOR("Douglas Gilbert");
1632MODULE_DESCRIPTION("SCSI generic (sg) driver");
1633MODULE_LICENSE("GPL");
1634MODULE_VERSION(SG_VERSION_STR);
1635MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1636
1637MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1638 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1639MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1640MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1641
1642#ifdef CONFIG_SYSCTL
1643#include <linux/sysctl.h>
1644
1645static struct ctl_table sg_sysctls[] = {
1646 {
1647 .procname = "sg-big-buff",
1648 .data = &sg_big_buff,
1649 .maxlen = sizeof(int),
1650 .mode = 0444,
1651 .proc_handler = proc_dointvec,
1652 },
1653};
1654
1655static struct ctl_table_header *hdr;
1656static void register_sg_sysctls(void)
1657{
1658 if (!hdr)
1659 hdr = register_sysctl("kernel", sg_sysctls);
1660}
1661
1662static void unregister_sg_sysctls(void)
1663{
1664 if (hdr)
1665 unregister_sysctl_table(hdr);
1666}
1667#else
1668#define register_sg_sysctls() do { } while (0)
1669#define unregister_sg_sysctls() do { } while (0)
1670#endif /* CONFIG_SYSCTL */
1671
1672static int __init
1673init_sg(void)
1674{
1675 int rc;
1676
1677 if (scatter_elem_sz < PAGE_SIZE) {
1678 scatter_elem_sz = PAGE_SIZE;
1679 scatter_elem_sz_prev = scatter_elem_sz;
1680 }
1681 if (def_reserved_size >= 0)
1682 sg_big_buff = def_reserved_size;
1683 else
1684 def_reserved_size = sg_big_buff;
1685
1686 rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1687 SG_MAX_DEVS, "sg");
1688 if (rc)
1689 return rc;
1690 sg_sysfs_class = class_create("scsi_generic");
1691 if ( IS_ERR(sg_sysfs_class) ) {
1692 rc = PTR_ERR(sg_sysfs_class);
1693 goto err_out;
1694 }
1695 sg_sysfs_valid = 1;
1696 rc = scsi_register_interface(&sg_interface);
1697 if (0 == rc) {
1698#ifdef CONFIG_SCSI_PROC_FS
1699 sg_proc_init();
1700#endif /* CONFIG_SCSI_PROC_FS */
1701 return 0;
1702 }
1703 class_destroy(sg_sysfs_class);
1704 register_sg_sysctls();
1705err_out:
1706 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1707 return rc;
1708}
1709
1710static void __exit
1711exit_sg(void)
1712{
1713 unregister_sg_sysctls();
1714#ifdef CONFIG_SCSI_PROC_FS
1715 remove_proc_subtree("scsi/sg", NULL);
1716#endif /* CONFIG_SCSI_PROC_FS */
1717 scsi_unregister_interface(&sg_interface);
1718 class_destroy(sg_sysfs_class);
1719 sg_sysfs_valid = 0;
1720 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1721 SG_MAX_DEVS);
1722 idr_destroy(&sg_index_idr);
1723}
1724
1725static int
1726sg_start_req(Sg_request *srp, unsigned char *cmd)
1727{
1728 int res;
1729 struct request *rq;
1730 Sg_fd *sfp = srp->parentfp;
1731 sg_io_hdr_t *hp = &srp->header;
1732 int dxfer_len = (int) hp->dxfer_len;
1733 int dxfer_dir = hp->dxfer_direction;
1734 unsigned int iov_count = hp->iovec_count;
1735 Sg_scatter_hold *req_schp = &srp->data;
1736 Sg_scatter_hold *rsv_schp = &sfp->reserve;
1737 struct request_queue *q = sfp->parentdp->device->request_queue;
1738 struct rq_map_data *md, map_data;
1739 int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? ITER_SOURCE : ITER_DEST;
1740 struct scsi_cmnd *scmd;
1741
1742 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1743 "sg_start_req: dxfer_len=%d\n",
1744 dxfer_len));
1745
1746 /*
1747 * NOTE
1748 *
1749 * With scsi-mq enabled, there are a fixed number of preallocated
1750 * requests equal in number to shost->can_queue. If all of the
1751 * preallocated requests are already in use, then scsi_alloc_request()
1752 * will sleep until an active command completes, freeing up a request.
1753 * Although waiting in an asynchronous interface is less than ideal, we
1754 * do not want to use BLK_MQ_REQ_NOWAIT here because userspace might
1755 * not expect an EWOULDBLOCK from this condition.
1756 */
1757 rq = scsi_alloc_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
1758 REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
1759 if (IS_ERR(rq))
1760 return PTR_ERR(rq);
1761 scmd = blk_mq_rq_to_pdu(rq);
1762
1763 if (hp->cmd_len > sizeof(scmd->cmnd)) {
1764 blk_mq_free_request(rq);
1765 return -EINVAL;
1766 }
1767
1768 memcpy(scmd->cmnd, cmd, hp->cmd_len);
1769 scmd->cmd_len = hp->cmd_len;
1770
1771 srp->rq = rq;
1772 rq->end_io_data = srp;
1773 scmd->allowed = SG_DEFAULT_RETRIES;
1774
1775 if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1776 return 0;
1777
1778 if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1779 dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1780 blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1781 md = NULL;
1782 else
1783 md = &map_data;
1784
1785 if (md) {
1786 mutex_lock(&sfp->f_mutex);
1787 if (dxfer_len <= rsv_schp->bufflen &&
1788 !sfp->res_in_use) {
1789 sfp->res_in_use = 1;
1790 sg_link_reserve(sfp, srp, dxfer_len);
1791 } else if (hp->flags & SG_FLAG_MMAP_IO) {
1792 res = -EBUSY; /* sfp->res_in_use == 1 */
1793 if (dxfer_len > rsv_schp->bufflen)
1794 res = -ENOMEM;
1795 mutex_unlock(&sfp->f_mutex);
1796 return res;
1797 } else {
1798 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1799 if (res) {
1800 mutex_unlock(&sfp->f_mutex);
1801 return res;
1802 }
1803 }
1804 mutex_unlock(&sfp->f_mutex);
1805
1806 md->pages = req_schp->pages;
1807 md->page_order = req_schp->page_order;
1808 md->nr_entries = req_schp->k_use_sg;
1809 md->offset = 0;
1810 md->null_mapped = hp->dxferp ? 0 : 1;
1811 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1812 md->from_user = 1;
1813 else
1814 md->from_user = 0;
1815 }
1816
1817 res = blk_rq_map_user_io(rq, md, hp->dxferp, hp->dxfer_len,
1818 GFP_ATOMIC, iov_count, iov_count, 1, rw);
1819 if (!res) {
1820 srp->bio = rq->bio;
1821
1822 if (!md) {
1823 req_schp->dio_in_use = 1;
1824 hp->info |= SG_INFO_DIRECT_IO;
1825 }
1826 }
1827 return res;
1828}
1829
1830static int
1831sg_finish_rem_req(Sg_request *srp)
1832{
1833 int ret = 0;
1834
1835 Sg_fd *sfp = srp->parentfp;
1836 Sg_scatter_hold *req_schp = &srp->data;
1837
1838 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1839 "sg_finish_rem_req: res_used=%d\n",
1840 (int) srp->res_used));
1841 if (srp->bio)
1842 ret = blk_rq_unmap_user(srp->bio);
1843
1844 if (srp->rq)
1845 blk_mq_free_request(srp->rq);
1846
1847 if (srp->res_used)
1848 sg_unlink_reserve(sfp, srp);
1849 else
1850 sg_remove_scat(sfp, req_schp);
1851
1852 return ret;
1853}
1854
1855static int
1856sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1857{
1858 int sg_bufflen = tablesize * sizeof(struct page *);
1859 gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1860
1861 schp->pages = kzalloc(sg_bufflen, gfp_flags);
1862 if (!schp->pages)
1863 return -ENOMEM;
1864 schp->sglist_len = sg_bufflen;
1865 return tablesize; /* number of scat_gath elements allocated */
1866}
1867
1868static int
1869sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1870{
1871 int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1872 int sg_tablesize = sfp->parentdp->sg_tablesize;
1873 int blk_size = buff_size, order;
1874 gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
1875
1876 if (blk_size < 0)
1877 return -EFAULT;
1878 if (0 == blk_size)
1879 ++blk_size; /* don't know why */
1880 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1881 blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1882 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1883 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1884 buff_size, blk_size));
1885
1886 /* N.B. ret_sz carried into this block ... */
1887 mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1888 if (mx_sc_elems < 0)
1889 return mx_sc_elems; /* most likely -ENOMEM */
1890
1891 num = scatter_elem_sz;
1892 if (unlikely(num != scatter_elem_sz_prev)) {
1893 if (num < PAGE_SIZE) {
1894 scatter_elem_sz = PAGE_SIZE;
1895 scatter_elem_sz_prev = PAGE_SIZE;
1896 } else
1897 scatter_elem_sz_prev = num;
1898 }
1899
1900 order = get_order(num);
1901retry:
1902 ret_sz = 1 << (PAGE_SHIFT + order);
1903
1904 for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1905 k++, rem_sz -= ret_sz) {
1906
1907 num = (rem_sz > scatter_elem_sz_prev) ?
1908 scatter_elem_sz_prev : rem_sz;
1909
1910 schp->pages[k] = alloc_pages(gfp_mask, order);
1911 if (!schp->pages[k])
1912 goto out;
1913
1914 if (num == scatter_elem_sz_prev) {
1915 if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1916 scatter_elem_sz = ret_sz;
1917 scatter_elem_sz_prev = ret_sz;
1918 }
1919 }
1920
1921 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1922 "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1923 k, num, ret_sz));
1924 } /* end of for loop */
1925
1926 schp->page_order = order;
1927 schp->k_use_sg = k;
1928 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1929 "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1930 k, rem_sz));
1931
1932 schp->bufflen = blk_size;
1933 if (rem_sz > 0) /* must have failed */
1934 return -ENOMEM;
1935 return 0;
1936out:
1937 for (i = 0; i < k; i++)
1938 __free_pages(schp->pages[i], order);
1939
1940 if (--order >= 0)
1941 goto retry;
1942
1943 return -ENOMEM;
1944}
1945
1946static void
1947sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1948{
1949 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1950 "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1951 if (schp->pages && schp->sglist_len > 0) {
1952 if (!schp->dio_in_use) {
1953 int k;
1954
1955 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1956 SCSI_LOG_TIMEOUT(5,
1957 sg_printk(KERN_INFO, sfp->parentdp,
1958 "sg_remove_scat: k=%d, pg=0x%p\n",
1959 k, schp->pages[k]));
1960 __free_pages(schp->pages[k], schp->page_order);
1961 }
1962
1963 kfree(schp->pages);
1964 }
1965 }
1966 memset(schp, 0, sizeof (*schp));
1967}
1968
1969static int
1970sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1971{
1972 Sg_scatter_hold *schp = &srp->data;
1973 int k, num;
1974
1975 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1976 "sg_read_oxfer: num_read_xfer=%d\n",
1977 num_read_xfer));
1978 if ((!outp) || (num_read_xfer <= 0))
1979 return 0;
1980
1981 num = 1 << (PAGE_SHIFT + schp->page_order);
1982 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1983 if (num > num_read_xfer) {
1984 if (copy_to_user(outp, page_address(schp->pages[k]),
1985 num_read_xfer))
1986 return -EFAULT;
1987 break;
1988 } else {
1989 if (copy_to_user(outp, page_address(schp->pages[k]),
1990 num))
1991 return -EFAULT;
1992 num_read_xfer -= num;
1993 if (num_read_xfer <= 0)
1994 break;
1995 outp += num;
1996 }
1997 }
1998
1999 return 0;
2000}
2001
2002static void
2003sg_build_reserve(Sg_fd * sfp, int req_size)
2004{
2005 Sg_scatter_hold *schp = &sfp->reserve;
2006
2007 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2008 "sg_build_reserve: req_size=%d\n", req_size));
2009 do {
2010 if (req_size < PAGE_SIZE)
2011 req_size = PAGE_SIZE;
2012 if (0 == sg_build_indirect(schp, sfp, req_size))
2013 return;
2014 else
2015 sg_remove_scat(sfp, schp);
2016 req_size >>= 1; /* divide by 2 */
2017 } while (req_size > (PAGE_SIZE / 2));
2018}
2019
2020static void
2021sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2022{
2023 Sg_scatter_hold *req_schp = &srp->data;
2024 Sg_scatter_hold *rsv_schp = &sfp->reserve;
2025 int k, num, rem;
2026
2027 srp->res_used = 1;
2028 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2029 "sg_link_reserve: size=%d\n", size));
2030 rem = size;
2031
2032 num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
2033 for (k = 0; k < rsv_schp->k_use_sg; k++) {
2034 if (rem <= num) {
2035 req_schp->k_use_sg = k + 1;
2036 req_schp->sglist_len = rsv_schp->sglist_len;
2037 req_schp->pages = rsv_schp->pages;
2038
2039 req_schp->bufflen = size;
2040 req_schp->page_order = rsv_schp->page_order;
2041 break;
2042 } else
2043 rem -= num;
2044 }
2045
2046 if (k >= rsv_schp->k_use_sg)
2047 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2048 "sg_link_reserve: BAD size\n"));
2049}
2050
2051static void
2052sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2053{
2054 Sg_scatter_hold *req_schp = &srp->data;
2055
2056 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2057 "sg_unlink_reserve: req->k_use_sg=%d\n",
2058 (int) req_schp->k_use_sg));
2059 req_schp->k_use_sg = 0;
2060 req_schp->bufflen = 0;
2061 req_schp->pages = NULL;
2062 req_schp->page_order = 0;
2063 req_schp->sglist_len = 0;
2064 srp->res_used = 0;
2065 /* Called without mutex lock to avoid deadlock */
2066 sfp->res_in_use = 0;
2067}
2068
2069static Sg_request *
2070sg_get_rq_mark(Sg_fd * sfp, int pack_id, bool *busy)
2071{
2072 Sg_request *resp;
2073 unsigned long iflags;
2074
2075 *busy = false;
2076 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2077 list_for_each_entry(resp, &sfp->rq_list, entry) {
2078 /* look for requests that are not SG_IO owned */
2079 if ((!resp->sg_io_owned) &&
2080 ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2081 switch (resp->done) {
2082 case 0: /* request active */
2083 *busy = true;
2084 break;
2085 case 1: /* request done; response ready to return */
2086 resp->done = 2; /* guard against other readers */
2087 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2088 return resp;
2089 case 2: /* response already being returned */
2090 break;
2091 }
2092 }
2093 }
2094 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2095 return NULL;
2096}
2097
2098/* always adds to end of list */
2099static Sg_request *
2100sg_add_request(Sg_fd * sfp)
2101{
2102 int k;
2103 unsigned long iflags;
2104 Sg_request *rp = sfp->req_arr;
2105
2106 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2107 if (!list_empty(&sfp->rq_list)) {
2108 if (!sfp->cmd_q)
2109 goto out_unlock;
2110
2111 for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2112 if (!rp->parentfp)
2113 break;
2114 }
2115 if (k >= SG_MAX_QUEUE)
2116 goto out_unlock;
2117 }
2118 memset(rp, 0, sizeof (Sg_request));
2119 rp->parentfp = sfp;
2120 rp->header.duration = jiffies_to_msecs(jiffies);
2121 list_add_tail(&rp->entry, &sfp->rq_list);
2122 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2123 return rp;
2124out_unlock:
2125 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2126 return NULL;
2127}
2128
2129/* Return of 1 for found; 0 for not found */
2130static int
2131sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2132{
2133 unsigned long iflags;
2134 int res = 0;
2135
2136 if (!sfp || !srp || list_empty(&sfp->rq_list))
2137 return res;
2138 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2139 if (!list_empty(&srp->entry)) {
2140 list_del(&srp->entry);
2141 srp->parentfp = NULL;
2142 res = 1;
2143 }
2144 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2145
2146 /*
2147 * If the device is detaching, wakeup any readers in case we just
2148 * removed the last response, which would leave nothing for them to
2149 * return other than -ENODEV.
2150 */
2151 if (unlikely(atomic_read(&sfp->parentdp->detaching)))
2152 wake_up_interruptible_all(&sfp->read_wait);
2153
2154 return res;
2155}
2156
2157static Sg_fd *
2158sg_add_sfp(Sg_device * sdp)
2159{
2160 Sg_fd *sfp;
2161 unsigned long iflags;
2162 int bufflen;
2163
2164 sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2165 if (!sfp)
2166 return ERR_PTR(-ENOMEM);
2167
2168 init_waitqueue_head(&sfp->read_wait);
2169 rwlock_init(&sfp->rq_list_lock);
2170 INIT_LIST_HEAD(&sfp->rq_list);
2171 kref_init(&sfp->f_ref);
2172 mutex_init(&sfp->f_mutex);
2173 sfp->timeout = SG_DEFAULT_TIMEOUT;
2174 sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2175 sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2176 sfp->cmd_q = SG_DEF_COMMAND_Q;
2177 sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2178 sfp->parentdp = sdp;
2179 write_lock_irqsave(&sdp->sfd_lock, iflags);
2180 if (atomic_read(&sdp->detaching)) {
2181 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2182 kfree(sfp);
2183 return ERR_PTR(-ENODEV);
2184 }
2185 list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2186 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2187 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2188 "sg_add_sfp: sfp=0x%p\n", sfp));
2189 if (unlikely(sg_big_buff != def_reserved_size))
2190 sg_big_buff = def_reserved_size;
2191
2192 bufflen = min_t(int, sg_big_buff,
2193 max_sectors_bytes(sdp->device->request_queue));
2194 sg_build_reserve(sfp, bufflen);
2195 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2196 "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2197 sfp->reserve.bufflen,
2198 sfp->reserve.k_use_sg));
2199
2200 kref_get(&sdp->d_ref);
2201 __module_get(THIS_MODULE);
2202 return sfp;
2203}
2204
2205static void
2206sg_remove_sfp_usercontext(struct work_struct *work)
2207{
2208 struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2209 struct sg_device *sdp = sfp->parentdp;
2210 Sg_request *srp;
2211 unsigned long iflags;
2212
2213 /* Cleanup any responses which were never read(). */
2214 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2215 while (!list_empty(&sfp->rq_list)) {
2216 srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2217 sg_finish_rem_req(srp);
2218 list_del(&srp->entry);
2219 srp->parentfp = NULL;
2220 }
2221 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2222
2223 if (sfp->reserve.bufflen > 0) {
2224 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2225 "sg_remove_sfp: bufflen=%d, k_use_sg=%d\n",
2226 (int) sfp->reserve.bufflen,
2227 (int) sfp->reserve.k_use_sg));
2228 sg_remove_scat(sfp, &sfp->reserve);
2229 }
2230
2231 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2232 "sg_remove_sfp: sfp=0x%p\n", sfp));
2233 kfree(sfp);
2234
2235 scsi_device_put(sdp->device);
2236 kref_put(&sdp->d_ref, sg_device_destroy);
2237 module_put(THIS_MODULE);
2238}
2239
2240static void
2241sg_remove_sfp(struct kref *kref)
2242{
2243 struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2244 struct sg_device *sdp = sfp->parentdp;
2245 unsigned long iflags;
2246
2247 write_lock_irqsave(&sdp->sfd_lock, iflags);
2248 list_del(&sfp->sfd_siblings);
2249 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2250
2251 INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2252 schedule_work(&sfp->ew.work);
2253}
2254
2255#ifdef CONFIG_SCSI_PROC_FS
2256static int
2257sg_idr_max_id(int id, void *p, void *data)
2258{
2259 int *k = data;
2260
2261 if (*k < id)
2262 *k = id;
2263
2264 return 0;
2265}
2266
2267static int
2268sg_last_dev(void)
2269{
2270 int k = -1;
2271 unsigned long iflags;
2272
2273 read_lock_irqsave(&sg_index_lock, iflags);
2274 idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2275 read_unlock_irqrestore(&sg_index_lock, iflags);
2276 return k + 1; /* origin 1 */
2277}
2278#endif
2279
2280/* must be called with sg_index_lock held */
2281static Sg_device *sg_lookup_dev(int dev)
2282{
2283 return idr_find(&sg_index_idr, dev);
2284}
2285
2286static Sg_device *
2287sg_get_dev(int dev)
2288{
2289 struct sg_device *sdp;
2290 unsigned long flags;
2291
2292 read_lock_irqsave(&sg_index_lock, flags);
2293 sdp = sg_lookup_dev(dev);
2294 if (!sdp)
2295 sdp = ERR_PTR(-ENXIO);
2296 else if (atomic_read(&sdp->detaching)) {
2297 /* If sdp->detaching, then the refcount may already be 0, in
2298 * which case it would be a bug to do kref_get().
2299 */
2300 sdp = ERR_PTR(-ENODEV);
2301 } else
2302 kref_get(&sdp->d_ref);
2303 read_unlock_irqrestore(&sg_index_lock, flags);
2304
2305 return sdp;
2306}
2307
2308#ifdef CONFIG_SCSI_PROC_FS
2309static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2310
2311static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2312static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2313 size_t count, loff_t *off);
2314static const struct proc_ops adio_proc_ops = {
2315 .proc_open = sg_proc_single_open_adio,
2316 .proc_read = seq_read,
2317 .proc_lseek = seq_lseek,
2318 .proc_write = sg_proc_write_adio,
2319 .proc_release = single_release,
2320};
2321
2322static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2323static ssize_t sg_proc_write_dressz(struct file *filp,
2324 const char __user *buffer, size_t count, loff_t *off);
2325static const struct proc_ops dressz_proc_ops = {
2326 .proc_open = sg_proc_single_open_dressz,
2327 .proc_read = seq_read,
2328 .proc_lseek = seq_lseek,
2329 .proc_write = sg_proc_write_dressz,
2330 .proc_release = single_release,
2331};
2332
2333static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2334static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2335static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2336static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2337static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2338static void dev_seq_stop(struct seq_file *s, void *v);
2339static const struct seq_operations dev_seq_ops = {
2340 .start = dev_seq_start,
2341 .next = dev_seq_next,
2342 .stop = dev_seq_stop,
2343 .show = sg_proc_seq_show_dev,
2344};
2345
2346static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2347static const struct seq_operations devstrs_seq_ops = {
2348 .start = dev_seq_start,
2349 .next = dev_seq_next,
2350 .stop = dev_seq_stop,
2351 .show = sg_proc_seq_show_devstrs,
2352};
2353
2354static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2355static const struct seq_operations debug_seq_ops = {
2356 .start = dev_seq_start,
2357 .next = dev_seq_next,
2358 .stop = dev_seq_stop,
2359 .show = sg_proc_seq_show_debug,
2360};
2361
2362static int
2363sg_proc_init(void)
2364{
2365 struct proc_dir_entry *p;
2366
2367 p = proc_mkdir("scsi/sg", NULL);
2368 if (!p)
2369 return 1;
2370
2371 proc_create("allow_dio", S_IRUGO | S_IWUSR, p, &adio_proc_ops);
2372 proc_create_seq("debug", S_IRUGO, p, &debug_seq_ops);
2373 proc_create("def_reserved_size", S_IRUGO | S_IWUSR, p, &dressz_proc_ops);
2374 proc_create_single("device_hdr", S_IRUGO, p, sg_proc_seq_show_devhdr);
2375 proc_create_seq("devices", S_IRUGO, p, &dev_seq_ops);
2376 proc_create_seq("device_strs", S_IRUGO, p, &devstrs_seq_ops);
2377 proc_create_single("version", S_IRUGO, p, sg_proc_seq_show_version);
2378 return 0;
2379}
2380
2381
2382static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2383{
2384 seq_printf(s, "%d\n", *((int *)s->private));
2385 return 0;
2386}
2387
2388static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2389{
2390 return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2391}
2392
2393static ssize_t
2394sg_proc_write_adio(struct file *filp, const char __user *buffer,
2395 size_t count, loff_t *off)
2396{
2397 int err;
2398 unsigned long num;
2399
2400 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2401 return -EACCES;
2402 err = kstrtoul_from_user(buffer, count, 0, &num);
2403 if (err)
2404 return err;
2405 sg_allow_dio = num ? 1 : 0;
2406 return count;
2407}
2408
2409static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2410{
2411 return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2412}
2413
2414static ssize_t
2415sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2416 size_t count, loff_t *off)
2417{
2418 int err;
2419 unsigned long k = ULONG_MAX;
2420
2421 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2422 return -EACCES;
2423
2424 err = kstrtoul_from_user(buffer, count, 0, &k);
2425 if (err)
2426 return err;
2427 if (k <= 1048576) { /* limit "big buff" to 1 MB */
2428 sg_big_buff = k;
2429 return count;
2430 }
2431 return -ERANGE;
2432}
2433
2434static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2435{
2436 seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2437 sg_version_date);
2438 return 0;
2439}
2440
2441static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2442{
2443 seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2444 return 0;
2445}
2446
2447struct sg_proc_deviter {
2448 loff_t index;
2449 size_t max;
2450};
2451
2452static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2453{
2454 struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2455
2456 s->private = it;
2457 if (! it)
2458 return NULL;
2459
2460 it->index = *pos;
2461 it->max = sg_last_dev();
2462 if (it->index >= it->max)
2463 return NULL;
2464 return it;
2465}
2466
2467static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2468{
2469 struct sg_proc_deviter * it = s->private;
2470
2471 *pos = ++it->index;
2472 return (it->index < it->max) ? it : NULL;
2473}
2474
2475static void dev_seq_stop(struct seq_file *s, void *v)
2476{
2477 kfree(s->private);
2478}
2479
2480static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2481{
2482 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2483 Sg_device *sdp;
2484 struct scsi_device *scsidp;
2485 unsigned long iflags;
2486
2487 read_lock_irqsave(&sg_index_lock, iflags);
2488 sdp = it ? sg_lookup_dev(it->index) : NULL;
2489 if ((NULL == sdp) || (NULL == sdp->device) ||
2490 (atomic_read(&sdp->detaching)))
2491 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2492 else {
2493 scsidp = sdp->device;
2494 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2495 scsidp->host->host_no, scsidp->channel,
2496 scsidp->id, scsidp->lun, (int) scsidp->type,
2497 1,
2498 (int) scsidp->queue_depth,
2499 (int) scsi_device_busy(scsidp),
2500 (int) scsi_device_online(scsidp));
2501 }
2502 read_unlock_irqrestore(&sg_index_lock, iflags);
2503 return 0;
2504}
2505
2506static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2507{
2508 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2509 Sg_device *sdp;
2510 struct scsi_device *scsidp;
2511 unsigned long iflags;
2512
2513 read_lock_irqsave(&sg_index_lock, iflags);
2514 sdp = it ? sg_lookup_dev(it->index) : NULL;
2515 scsidp = sdp ? sdp->device : NULL;
2516 if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2517 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2518 scsidp->vendor, scsidp->model, scsidp->rev);
2519 else
2520 seq_puts(s, "<no active device>\n");
2521 read_unlock_irqrestore(&sg_index_lock, iflags);
2522 return 0;
2523}
2524
2525/* must be called while holding sg_index_lock */
2526static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2527{
2528 int k, new_interface, blen, usg;
2529 Sg_request *srp;
2530 Sg_fd *fp;
2531 const sg_io_hdr_t *hp;
2532 const char * cp;
2533 unsigned int ms;
2534
2535 k = 0;
2536 list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2537 k++;
2538 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2539 seq_printf(s, " FD(%d): timeout=%dms bufflen=%d "
2540 "(res)sgat=%d low_dma=%d\n", k,
2541 jiffies_to_msecs(fp->timeout),
2542 fp->reserve.bufflen,
2543 (int) fp->reserve.k_use_sg, 0);
2544 seq_printf(s, " cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2545 (int) fp->cmd_q, (int) fp->force_packid,
2546 (int) fp->keep_orphan);
2547 list_for_each_entry(srp, &fp->rq_list, entry) {
2548 hp = &srp->header;
2549 new_interface = (hp->interface_id == '\0') ? 0 : 1;
2550 if (srp->res_used) {
2551 if (new_interface &&
2552 (SG_FLAG_MMAP_IO & hp->flags))
2553 cp = " mmap>> ";
2554 else
2555 cp = " rb>> ";
2556 } else {
2557 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2558 cp = " dio>> ";
2559 else
2560 cp = " ";
2561 }
2562 seq_puts(s, cp);
2563 blen = srp->data.bufflen;
2564 usg = srp->data.k_use_sg;
2565 seq_puts(s, srp->done ?
2566 ((1 == srp->done) ? "rcv:" : "fin:")
2567 : "act:");
2568 seq_printf(s, " id=%d blen=%d",
2569 srp->header.pack_id, blen);
2570 if (srp->done)
2571 seq_printf(s, " dur=%d", hp->duration);
2572 else {
2573 ms = jiffies_to_msecs(jiffies);
2574 seq_printf(s, " t_o/elap=%d/%d",
2575 (new_interface ? hp->timeout :
2576 jiffies_to_msecs(fp->timeout)),
2577 (ms > hp->duration ? ms - hp->duration : 0));
2578 }
2579 seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2580 (int) srp->data.cmd_opcode);
2581 }
2582 if (list_empty(&fp->rq_list))
2583 seq_puts(s, " No requests active\n");
2584 read_unlock(&fp->rq_list_lock);
2585 }
2586}
2587
2588static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2589{
2590 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2591 Sg_device *sdp;
2592 unsigned long iflags;
2593
2594 if (it && (0 == it->index))
2595 seq_printf(s, "max_active_device=%d def_reserved_size=%d\n",
2596 (int)it->max, sg_big_buff);
2597
2598 read_lock_irqsave(&sg_index_lock, iflags);
2599 sdp = it ? sg_lookup_dev(it->index) : NULL;
2600 if (NULL == sdp)
2601 goto skip;
2602 read_lock(&sdp->sfd_lock);
2603 if (!list_empty(&sdp->sfds)) {
2604 seq_printf(s, " >>> device=%s ", sdp->name);
2605 if (atomic_read(&sdp->detaching))
2606 seq_puts(s, "detaching pending close ");
2607 else if (sdp->device) {
2608 struct scsi_device *scsidp = sdp->device;
2609
2610 seq_printf(s, "%d:%d:%d:%llu em=%d",
2611 scsidp->host->host_no,
2612 scsidp->channel, scsidp->id,
2613 scsidp->lun,
2614 scsidp->host->hostt->emulated);
2615 }
2616 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2617 sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2618 sg_proc_debug_helper(s, sdp);
2619 }
2620 read_unlock(&sdp->sfd_lock);
2621skip:
2622 read_unlock_irqrestore(&sg_index_lock, iflags);
2623 return 0;
2624}
2625
2626#endif /* CONFIG_SCSI_PROC_FS */
2627
2628module_init(init_sg);
2629module_exit(exit_sg);
1/*
2 * History:
3 * Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
4 * to allow user process control of SCSI devices.
5 * Development Sponsored by Killy Corp. NY NY
6 *
7 * Original driver (sg.c):
8 * Copyright (C) 1992 Lawrence Foard
9 * Version 2 and 3 extensions to driver:
10 * Copyright (C) 1998 - 2014 Douglas Gilbert
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2, or (at your option)
15 * any later version.
16 *
17 */
18
19static int sg_version_num = 30536; /* 2 digits for each component */
20#define SG_VERSION_STR "3.5.36"
21
22/*
23 * D. P. Gilbert (dgilbert@interlog.com), notes:
24 * - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
25 * the kernel/module needs to be built with CONFIG_SCSI_LOGGING
26 * (otherwise the macros compile to empty statements).
27 *
28 */
29#include <linux/module.h>
30
31#include <linux/fs.h>
32#include <linux/kernel.h>
33#include <linux/sched.h>
34#include <linux/string.h>
35#include <linux/mm.h>
36#include <linux/errno.h>
37#include <linux/mtio.h>
38#include <linux/ioctl.h>
39#include <linux/slab.h>
40#include <linux/fcntl.h>
41#include <linux/init.h>
42#include <linux/poll.h>
43#include <linux/moduleparam.h>
44#include <linux/cdev.h>
45#include <linux/idr.h>
46#include <linux/seq_file.h>
47#include <linux/blkdev.h>
48#include <linux/delay.h>
49#include <linux/blktrace_api.h>
50#include <linux/mutex.h>
51#include <linux/atomic.h>
52#include <linux/ratelimit.h>
53#include <linux/uio.h>
54
55#include "scsi.h"
56#include <scsi/scsi_dbg.h>
57#include <scsi/scsi_host.h>
58#include <scsi/scsi_driver.h>
59#include <scsi/scsi_ioctl.h>
60#include <scsi/sg.h>
61
62#include "scsi_logging.h"
63
64#ifdef CONFIG_SCSI_PROC_FS
65#include <linux/proc_fs.h>
66static char *sg_version_date = "20140603";
67
68static int sg_proc_init(void);
69static void sg_proc_cleanup(void);
70#endif
71
72#define SG_ALLOW_DIO_DEF 0
73
74#define SG_MAX_DEVS 32768
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
84int 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 *, struct class_interface *);
100static void sg_remove_device(struct device *, struct class_interface *);
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 sg_request *nextrp; /* NULL -> tail request (slist) */
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 int timeout; /* defaults to SG_DEFAULT_TIMEOUT */
146 int timeout_user; /* defaults to SG_DEFAULT_TIMEOUT_USER */
147 Sg_scatter_hold reserve; /* buffer held for this file descriptor */
148 unsigned save_scat_len; /* original length of trunc. scat. element */
149 Sg_request *headrp; /* head of request slist, NULL->empty */
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 low_dma; /* as in parent but possibly overridden to 1 */
153 char force_packid; /* 1 -> pack_id input to read(), 0 -> ignored */
154 char cmd_q; /* 1 -> allow command queuing, 0 -> don't */
155 unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */
156 char keep_orphan; /* 0 -> drop orphan (def), 1 -> keep for read() */
157 char mmap_called; /* 0 -> mmap() never called on this fd */
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 struct gendisk *disk;
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 void sg_rq_end_io(struct request *rq, int uptodate);
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);
199static Sg_request *sg_add_request(Sg_fd * sfp);
200static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
201static int sg_res_in_use(Sg_fd * sfp);
202static Sg_device *sg_get_dev(int dev);
203static void sg_device_destroy(struct kref *kref);
204
205#define SZ_SG_HEADER sizeof(struct sg_header)
206#define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
207#define SZ_SG_IOVEC sizeof(sg_iovec_t)
208#define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
209
210#define sg_printk(prefix, sdp, fmt, a...) \
211 sdev_prefix_printk(prefix, (sdp)->device, \
212 (sdp)->disk->disk_name, fmt, ##a)
213
214static int sg_allow_access(struct file *filp, unsigned char *cmd)
215{
216 struct sg_fd *sfp = filp->private_data;
217
218 if (sfp->parentdp->device->type == TYPE_SCANNER)
219 return 0;
220
221 return blk_verify_command(cmd, filp->f_mode & FMODE_WRITE);
222}
223
224static int
225open_wait(Sg_device *sdp, int flags)
226{
227 int retval = 0;
228
229 if (flags & O_EXCL) {
230 while (sdp->open_cnt > 0) {
231 mutex_unlock(&sdp->open_rel_lock);
232 retval = wait_event_interruptible(sdp->open_wait,
233 (atomic_read(&sdp->detaching) ||
234 !sdp->open_cnt));
235 mutex_lock(&sdp->open_rel_lock);
236
237 if (retval) /* -ERESTARTSYS */
238 return retval;
239 if (atomic_read(&sdp->detaching))
240 return -ENODEV;
241 }
242 } else {
243 while (sdp->exclude) {
244 mutex_unlock(&sdp->open_rel_lock);
245 retval = wait_event_interruptible(sdp->open_wait,
246 (atomic_read(&sdp->detaching) ||
247 !sdp->exclude));
248 mutex_lock(&sdp->open_rel_lock);
249
250 if (retval) /* -ERESTARTSYS */
251 return retval;
252 if (atomic_read(&sdp->detaching))
253 return -ENODEV;
254 }
255 }
256
257 return retval;
258}
259
260/* Returns 0 on success, else a negated errno value */
261static int
262sg_open(struct inode *inode, struct file *filp)
263{
264 int dev = iminor(inode);
265 int flags = filp->f_flags;
266 struct request_queue *q;
267 Sg_device *sdp;
268 Sg_fd *sfp;
269 int retval;
270
271 nonseekable_open(inode, filp);
272 if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
273 return -EPERM; /* Can't lock it with read only access */
274 sdp = sg_get_dev(dev);
275 if (IS_ERR(sdp))
276 return PTR_ERR(sdp);
277
278 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
279 "sg_open: flags=0x%x\n", flags));
280
281 /* This driver's module count bumped by fops_get in <linux/fs.h> */
282 /* Prevent the device driver from vanishing while we sleep */
283 retval = scsi_device_get(sdp->device);
284 if (retval)
285 goto sg_put;
286
287 retval = scsi_autopm_get_device(sdp->device);
288 if (retval)
289 goto sdp_put;
290
291 /* scsi_block_when_processing_errors() may block so bypass
292 * check if O_NONBLOCK. Permits SCSI commands to be issued
293 * during error recovery. Tread carefully. */
294 if (!((flags & O_NONBLOCK) ||
295 scsi_block_when_processing_errors(sdp->device))) {
296 retval = -ENXIO;
297 /* we are in error recovery for this device */
298 goto error_out;
299 }
300
301 mutex_lock(&sdp->open_rel_lock);
302 if (flags & O_NONBLOCK) {
303 if (flags & O_EXCL) {
304 if (sdp->open_cnt > 0) {
305 retval = -EBUSY;
306 goto error_mutex_locked;
307 }
308 } else {
309 if (sdp->exclude) {
310 retval = -EBUSY;
311 goto error_mutex_locked;
312 }
313 }
314 } else {
315 retval = open_wait(sdp, flags);
316 if (retval) /* -ERESTARTSYS or -ENODEV */
317 goto error_mutex_locked;
318 }
319
320 /* N.B. at this point we are holding the open_rel_lock */
321 if (flags & O_EXCL)
322 sdp->exclude = true;
323
324 if (sdp->open_cnt < 1) { /* no existing opens */
325 sdp->sgdebug = 0;
326 q = sdp->device->request_queue;
327 sdp->sg_tablesize = queue_max_segments(q);
328 }
329 sfp = sg_add_sfp(sdp);
330 if (IS_ERR(sfp)) {
331 retval = PTR_ERR(sfp);
332 goto out_undo;
333 }
334
335 filp->private_data = sfp;
336 sdp->open_cnt++;
337 mutex_unlock(&sdp->open_rel_lock);
338
339 retval = 0;
340sg_put:
341 kref_put(&sdp->d_ref, sg_device_destroy);
342 return retval;
343
344out_undo:
345 if (flags & O_EXCL) {
346 sdp->exclude = false; /* undo if error */
347 wake_up_interruptible(&sdp->open_wait);
348 }
349error_mutex_locked:
350 mutex_unlock(&sdp->open_rel_lock);
351error_out:
352 scsi_autopm_put_device(sdp->device);
353sdp_put:
354 scsi_device_put(sdp->device);
355 goto sg_put;
356}
357
358/* Release resources associated with a successful sg_open()
359 * Returns 0 on success, else a negated errno value */
360static int
361sg_release(struct inode *inode, struct file *filp)
362{
363 Sg_device *sdp;
364 Sg_fd *sfp;
365
366 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
367 return -ENXIO;
368 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
369
370 mutex_lock(&sdp->open_rel_lock);
371 scsi_autopm_put_device(sdp->device);
372 kref_put(&sfp->f_ref, sg_remove_sfp);
373 sdp->open_cnt--;
374
375 /* possibly many open()s waiting on exlude clearing, start many;
376 * only open(O_EXCL)s wait on 0==open_cnt so only start one */
377 if (sdp->exclude) {
378 sdp->exclude = false;
379 wake_up_interruptible_all(&sdp->open_wait);
380 } else if (0 == sdp->open_cnt) {
381 wake_up_interruptible(&sdp->open_wait);
382 }
383 mutex_unlock(&sdp->open_rel_lock);
384 return 0;
385}
386
387static ssize_t
388sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
389{
390 Sg_device *sdp;
391 Sg_fd *sfp;
392 Sg_request *srp;
393 int req_pack_id = -1;
394 sg_io_hdr_t *hp;
395 struct sg_header *old_hdr = NULL;
396 int retval = 0;
397
398 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
399 return -ENXIO;
400 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
401 "sg_read: count=%d\n", (int) count));
402
403 if (!access_ok(VERIFY_WRITE, buf, count))
404 return -EFAULT;
405 if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
406 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
407 if (!old_hdr)
408 return -ENOMEM;
409 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
410 retval = -EFAULT;
411 goto free_old_hdr;
412 }
413 if (old_hdr->reply_len < 0) {
414 if (count >= SZ_SG_IO_HDR) {
415 sg_io_hdr_t *new_hdr;
416 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
417 if (!new_hdr) {
418 retval = -ENOMEM;
419 goto free_old_hdr;
420 }
421 retval =__copy_from_user
422 (new_hdr, buf, SZ_SG_IO_HDR);
423 req_pack_id = new_hdr->pack_id;
424 kfree(new_hdr);
425 if (retval) {
426 retval = -EFAULT;
427 goto free_old_hdr;
428 }
429 }
430 } else
431 req_pack_id = old_hdr->pack_id;
432 }
433 srp = sg_get_rq_mark(sfp, req_pack_id);
434 if (!srp) { /* now wait on packet to arrive */
435 if (atomic_read(&sdp->detaching)) {
436 retval = -ENODEV;
437 goto free_old_hdr;
438 }
439 if (filp->f_flags & O_NONBLOCK) {
440 retval = -EAGAIN;
441 goto free_old_hdr;
442 }
443 retval = wait_event_interruptible(sfp->read_wait,
444 (atomic_read(&sdp->detaching) ||
445 (srp = sg_get_rq_mark(sfp, req_pack_id))));
446 if (atomic_read(&sdp->detaching)) {
447 retval = -ENODEV;
448 goto free_old_hdr;
449 }
450 if (retval) {
451 /* -ERESTARTSYS as signal hit process */
452 goto free_old_hdr;
453 }
454 }
455 if (srp->header.interface_id != '\0') {
456 retval = sg_new_read(sfp, buf, count, srp);
457 goto free_old_hdr;
458 }
459
460 hp = &srp->header;
461 if (old_hdr == NULL) {
462 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
463 if (! old_hdr) {
464 retval = -ENOMEM;
465 goto free_old_hdr;
466 }
467 }
468 memset(old_hdr, 0, SZ_SG_HEADER);
469 old_hdr->reply_len = (int) hp->timeout;
470 old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
471 old_hdr->pack_id = hp->pack_id;
472 old_hdr->twelve_byte =
473 ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
474 old_hdr->target_status = hp->masked_status;
475 old_hdr->host_status = hp->host_status;
476 old_hdr->driver_status = hp->driver_status;
477 if ((CHECK_CONDITION & hp->masked_status) ||
478 (DRIVER_SENSE & hp->driver_status))
479 memcpy(old_hdr->sense_buffer, srp->sense_b,
480 sizeof (old_hdr->sense_buffer));
481 switch (hp->host_status) {
482 /* This setup of 'result' is for backward compatibility and is best
483 ignored by the user who should use target, host + driver status */
484 case DID_OK:
485 case DID_PASSTHROUGH:
486 case DID_SOFT_ERROR:
487 old_hdr->result = 0;
488 break;
489 case DID_NO_CONNECT:
490 case DID_BUS_BUSY:
491 case DID_TIME_OUT:
492 old_hdr->result = EBUSY;
493 break;
494 case DID_BAD_TARGET:
495 case DID_ABORT:
496 case DID_PARITY:
497 case DID_RESET:
498 case DID_BAD_INTR:
499 old_hdr->result = EIO;
500 break;
501 case DID_ERROR:
502 old_hdr->result = (srp->sense_b[0] == 0 &&
503 hp->masked_status == GOOD) ? 0 : EIO;
504 break;
505 default:
506 old_hdr->result = EIO;
507 break;
508 }
509
510 /* Now copy the result back to the user buffer. */
511 if (count >= SZ_SG_HEADER) {
512 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
513 retval = -EFAULT;
514 goto free_old_hdr;
515 }
516 buf += SZ_SG_HEADER;
517 if (count > old_hdr->reply_len)
518 count = old_hdr->reply_len;
519 if (count > SZ_SG_HEADER) {
520 if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
521 retval = -EFAULT;
522 goto free_old_hdr;
523 }
524 }
525 } else
526 count = (old_hdr->result == 0) ? 0 : -EIO;
527 sg_finish_rem_req(srp);
528 retval = count;
529free_old_hdr:
530 kfree(old_hdr);
531 return retval;
532}
533
534static ssize_t
535sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
536{
537 sg_io_hdr_t *hp = &srp->header;
538 int err = 0, err2;
539 int len;
540
541 if (count < SZ_SG_IO_HDR) {
542 err = -EINVAL;
543 goto err_out;
544 }
545 hp->sb_len_wr = 0;
546 if ((hp->mx_sb_len > 0) && hp->sbp) {
547 if ((CHECK_CONDITION & hp->masked_status) ||
548 (DRIVER_SENSE & hp->driver_status)) {
549 int sb_len = SCSI_SENSE_BUFFERSIZE;
550 sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
551 len = 8 + (int) srp->sense_b[7]; /* Additional sense length field */
552 len = (len > sb_len) ? sb_len : len;
553 if (copy_to_user(hp->sbp, srp->sense_b, len)) {
554 err = -EFAULT;
555 goto err_out;
556 }
557 hp->sb_len_wr = len;
558 }
559 }
560 if (hp->masked_status || hp->host_status || hp->driver_status)
561 hp->info |= SG_INFO_CHECK;
562 if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
563 err = -EFAULT;
564 goto err_out;
565 }
566err_out:
567 err2 = sg_finish_rem_req(srp);
568 return err ? : err2 ? : count;
569}
570
571static ssize_t
572sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
573{
574 int mxsize, cmd_size, k;
575 int input_size, blocking;
576 unsigned char opcode;
577 Sg_device *sdp;
578 Sg_fd *sfp;
579 Sg_request *srp;
580 struct sg_header old_hdr;
581 sg_io_hdr_t *hp;
582 unsigned char cmnd[SG_MAX_CDB_SIZE];
583
584 if (unlikely(segment_eq(get_fs(), KERNEL_DS)))
585 return -EINVAL;
586
587 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
588 return -ENXIO;
589 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
590 "sg_write: count=%d\n", (int) count));
591 if (atomic_read(&sdp->detaching))
592 return -ENODEV;
593 if (!((filp->f_flags & O_NONBLOCK) ||
594 scsi_block_when_processing_errors(sdp->device)))
595 return -ENXIO;
596
597 if (!access_ok(VERIFY_READ, buf, count))
598 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
599 if (count < SZ_SG_HEADER)
600 return -EIO;
601 if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
602 return -EFAULT;
603 blocking = !(filp->f_flags & O_NONBLOCK);
604 if (old_hdr.reply_len < 0)
605 return sg_new_write(sfp, filp, buf, count,
606 blocking, 0, 0, NULL);
607 if (count < (SZ_SG_HEADER + 6))
608 return -EIO; /* The minimum scsi command length is 6 bytes. */
609
610 if (!(srp = sg_add_request(sfp))) {
611 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
612 "sg_write: queue full\n"));
613 return -EDOM;
614 }
615 buf += SZ_SG_HEADER;
616 __get_user(opcode, buf);
617 if (sfp->next_cmd_len > 0) {
618 cmd_size = sfp->next_cmd_len;
619 sfp->next_cmd_len = 0; /* reset so only this write() effected */
620 } else {
621 cmd_size = COMMAND_SIZE(opcode); /* based on SCSI command group */
622 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
623 cmd_size = 12;
624 }
625 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
626 "sg_write: scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
627/* Determine buffer size. */
628 input_size = count - cmd_size;
629 mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
630 mxsize -= SZ_SG_HEADER;
631 input_size -= SZ_SG_HEADER;
632 if (input_size < 0) {
633 sg_remove_request(sfp, srp);
634 return -EIO; /* User did not pass enough bytes for this command. */
635 }
636 hp = &srp->header;
637 hp->interface_id = '\0'; /* indicator of old interface tunnelled */
638 hp->cmd_len = (unsigned char) cmd_size;
639 hp->iovec_count = 0;
640 hp->mx_sb_len = 0;
641 if (input_size > 0)
642 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
643 SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
644 else
645 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
646 hp->dxfer_len = mxsize;
647 if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
648 (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
649 hp->dxferp = (char __user *)buf + cmd_size;
650 else
651 hp->dxferp = NULL;
652 hp->sbp = NULL;
653 hp->timeout = old_hdr.reply_len; /* structure abuse ... */
654 hp->flags = input_size; /* structure abuse ... */
655 hp->pack_id = old_hdr.pack_id;
656 hp->usr_ptr = NULL;
657 if (__copy_from_user(cmnd, buf, cmd_size))
658 return -EFAULT;
659 /*
660 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
661 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
662 * is a non-zero input_size, so emit a warning.
663 */
664 if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
665 static char cmd[TASK_COMM_LEN];
666 if (strcmp(current->comm, cmd)) {
667 printk_ratelimited(KERN_WARNING
668 "sg_write: data in/out %d/%d bytes "
669 "for SCSI command 0x%x-- guessing "
670 "data in;\n program %s not setting "
671 "count and/or reply_len properly\n",
672 old_hdr.reply_len - (int)SZ_SG_HEADER,
673 input_size, (unsigned int) cmnd[0],
674 current->comm);
675 strcpy(cmd, current->comm);
676 }
677 }
678 k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
679 return (k < 0) ? k : count;
680}
681
682static ssize_t
683sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
684 size_t count, int blocking, int read_only, int sg_io_owned,
685 Sg_request **o_srp)
686{
687 int k;
688 Sg_request *srp;
689 sg_io_hdr_t *hp;
690 unsigned char cmnd[SG_MAX_CDB_SIZE];
691 int timeout;
692 unsigned long ul_timeout;
693
694 if (count < SZ_SG_IO_HDR)
695 return -EINVAL;
696 if (!access_ok(VERIFY_READ, buf, count))
697 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
698
699 sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
700 if (!(srp = sg_add_request(sfp))) {
701 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
702 "sg_new_write: queue full\n"));
703 return -EDOM;
704 }
705 srp->sg_io_owned = sg_io_owned;
706 hp = &srp->header;
707 if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
708 sg_remove_request(sfp, srp);
709 return -EFAULT;
710 }
711 if (hp->interface_id != 'S') {
712 sg_remove_request(sfp, srp);
713 return -ENOSYS;
714 }
715 if (hp->flags & SG_FLAG_MMAP_IO) {
716 if (hp->dxfer_len > sfp->reserve.bufflen) {
717 sg_remove_request(sfp, srp);
718 return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
719 }
720 if (hp->flags & SG_FLAG_DIRECT_IO) {
721 sg_remove_request(sfp, srp);
722 return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
723 }
724 if (sg_res_in_use(sfp)) {
725 sg_remove_request(sfp, srp);
726 return -EBUSY; /* reserve buffer already being used */
727 }
728 }
729 ul_timeout = msecs_to_jiffies(srp->header.timeout);
730 timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
731 if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
732 sg_remove_request(sfp, srp);
733 return -EMSGSIZE;
734 }
735 if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
736 sg_remove_request(sfp, srp);
737 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
738 }
739 if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
740 sg_remove_request(sfp, srp);
741 return -EFAULT;
742 }
743 if (read_only && sg_allow_access(file, cmnd)) {
744 sg_remove_request(sfp, srp);
745 return -EPERM;
746 }
747 k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
748 if (k < 0)
749 return k;
750 if (o_srp)
751 *o_srp = srp;
752 return count;
753}
754
755static int
756sg_common_write(Sg_fd * sfp, Sg_request * srp,
757 unsigned char *cmnd, int timeout, int blocking)
758{
759 int k, at_head;
760 Sg_device *sdp = sfp->parentdp;
761 sg_io_hdr_t *hp = &srp->header;
762
763 srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
764 hp->status = 0;
765 hp->masked_status = 0;
766 hp->msg_status = 0;
767 hp->info = 0;
768 hp->host_status = 0;
769 hp->driver_status = 0;
770 hp->resid = 0;
771 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
772 "sg_common_write: scsi opcode=0x%02x, cmd_size=%d\n",
773 (int) cmnd[0], (int) hp->cmd_len));
774
775 k = sg_start_req(srp, cmnd);
776 if (k) {
777 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
778 "sg_common_write: start_req err=%d\n", k));
779 sg_finish_rem_req(srp);
780 return k; /* probably out of space --> ENOMEM */
781 }
782 if (atomic_read(&sdp->detaching)) {
783 if (srp->bio) {
784 if (srp->rq->cmd != srp->rq->__cmd)
785 kfree(srp->rq->cmd);
786
787 blk_end_request_all(srp->rq, -EIO);
788 srp->rq = NULL;
789 }
790
791 sg_finish_rem_req(srp);
792 return -ENODEV;
793 }
794
795 hp->duration = jiffies_to_msecs(jiffies);
796 if (hp->interface_id != '\0' && /* v3 (or later) interface */
797 (SG_FLAG_Q_AT_TAIL & hp->flags))
798 at_head = 0;
799 else
800 at_head = 1;
801
802 srp->rq->timeout = timeout;
803 kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
804 blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
805 srp->rq, at_head, sg_rq_end_io);
806 return 0;
807}
808
809static int srp_done(Sg_fd *sfp, Sg_request *srp)
810{
811 unsigned long flags;
812 int ret;
813
814 read_lock_irqsave(&sfp->rq_list_lock, flags);
815 ret = srp->done;
816 read_unlock_irqrestore(&sfp->rq_list_lock, flags);
817 return ret;
818}
819
820static int max_sectors_bytes(struct request_queue *q)
821{
822 unsigned int max_sectors = queue_max_sectors(q);
823
824 max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
825
826 return max_sectors << 9;
827}
828
829static long
830sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
831{
832 void __user *p = (void __user *)arg;
833 int __user *ip = p;
834 int result, val, read_only;
835 Sg_device *sdp;
836 Sg_fd *sfp;
837 Sg_request *srp;
838 unsigned long iflags;
839
840 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
841 return -ENXIO;
842
843 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
844 "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
845 read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
846
847 switch (cmd_in) {
848 case SG_IO:
849 if (atomic_read(&sdp->detaching))
850 return -ENODEV;
851 if (!scsi_block_when_processing_errors(sdp->device))
852 return -ENXIO;
853 if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
854 return -EFAULT;
855 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
856 1, read_only, 1, &srp);
857 if (result < 0)
858 return result;
859 result = wait_event_interruptible(sfp->read_wait,
860 (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
861 if (atomic_read(&sdp->detaching))
862 return -ENODEV;
863 write_lock_irq(&sfp->rq_list_lock);
864 if (srp->done) {
865 srp->done = 2;
866 write_unlock_irq(&sfp->rq_list_lock);
867 result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
868 return (result < 0) ? result : 0;
869 }
870 srp->orphan = 1;
871 write_unlock_irq(&sfp->rq_list_lock);
872 return result; /* -ERESTARTSYS because signal hit process */
873 case SG_SET_TIMEOUT:
874 result = get_user(val, ip);
875 if (result)
876 return result;
877 if (val < 0)
878 return -EIO;
879 if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
880 val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
881 INT_MAX);
882 sfp->timeout_user = val;
883 sfp->timeout = mult_frac(val, HZ, USER_HZ);
884
885 return 0;
886 case SG_GET_TIMEOUT: /* N.B. User receives timeout as return value */
887 /* strange ..., for backward compatibility */
888 return sfp->timeout_user;
889 case SG_SET_FORCE_LOW_DMA:
890 result = get_user(val, ip);
891 if (result)
892 return result;
893 if (val) {
894 sfp->low_dma = 1;
895 if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
896 val = (int) sfp->reserve.bufflen;
897 sg_remove_scat(sfp, &sfp->reserve);
898 sg_build_reserve(sfp, val);
899 }
900 } else {
901 if (atomic_read(&sdp->detaching))
902 return -ENODEV;
903 sfp->low_dma = sdp->device->host->unchecked_isa_dma;
904 }
905 return 0;
906 case SG_GET_LOW_DMA:
907 return put_user((int) sfp->low_dma, ip);
908 case SG_GET_SCSI_ID:
909 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
910 return -EFAULT;
911 else {
912 sg_scsi_id_t __user *sg_idp = p;
913
914 if (atomic_read(&sdp->detaching))
915 return -ENODEV;
916 __put_user((int) sdp->device->host->host_no,
917 &sg_idp->host_no);
918 __put_user((int) sdp->device->channel,
919 &sg_idp->channel);
920 __put_user((int) sdp->device->id, &sg_idp->scsi_id);
921 __put_user((int) sdp->device->lun, &sg_idp->lun);
922 __put_user((int) sdp->device->type, &sg_idp->scsi_type);
923 __put_user((short) sdp->device->host->cmd_per_lun,
924 &sg_idp->h_cmd_per_lun);
925 __put_user((short) sdp->device->queue_depth,
926 &sg_idp->d_queue_depth);
927 __put_user(0, &sg_idp->unused[0]);
928 __put_user(0, &sg_idp->unused[1]);
929 return 0;
930 }
931 case SG_SET_FORCE_PACK_ID:
932 result = get_user(val, ip);
933 if (result)
934 return result;
935 sfp->force_packid = val ? 1 : 0;
936 return 0;
937 case SG_GET_PACK_ID:
938 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
939 return -EFAULT;
940 read_lock_irqsave(&sfp->rq_list_lock, iflags);
941 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
942 if ((1 == srp->done) && (!srp->sg_io_owned)) {
943 read_unlock_irqrestore(&sfp->rq_list_lock,
944 iflags);
945 __put_user(srp->header.pack_id, ip);
946 return 0;
947 }
948 }
949 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
950 __put_user(-1, ip);
951 return 0;
952 case SG_GET_NUM_WAITING:
953 read_lock_irqsave(&sfp->rq_list_lock, iflags);
954 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
955 if ((1 == srp->done) && (!srp->sg_io_owned))
956 ++val;
957 }
958 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
959 return put_user(val, ip);
960 case SG_GET_SG_TABLESIZE:
961 return put_user(sdp->sg_tablesize, ip);
962 case SG_SET_RESERVED_SIZE:
963 result = get_user(val, ip);
964 if (result)
965 return result;
966 if (val < 0)
967 return -EINVAL;
968 val = min_t(int, val,
969 max_sectors_bytes(sdp->device->request_queue));
970 if (val != sfp->reserve.bufflen) {
971 if (sg_res_in_use(sfp) || sfp->mmap_called)
972 return -EBUSY;
973 sg_remove_scat(sfp, &sfp->reserve);
974 sg_build_reserve(sfp, val);
975 }
976 return 0;
977 case SG_GET_RESERVED_SIZE:
978 val = min_t(int, sfp->reserve.bufflen,
979 max_sectors_bytes(sdp->device->request_queue));
980 return put_user(val, ip);
981 case SG_SET_COMMAND_Q:
982 result = get_user(val, ip);
983 if (result)
984 return result;
985 sfp->cmd_q = val ? 1 : 0;
986 return 0;
987 case SG_GET_COMMAND_Q:
988 return put_user((int) sfp->cmd_q, ip);
989 case SG_SET_KEEP_ORPHAN:
990 result = get_user(val, ip);
991 if (result)
992 return result;
993 sfp->keep_orphan = val;
994 return 0;
995 case SG_GET_KEEP_ORPHAN:
996 return put_user((int) sfp->keep_orphan, ip);
997 case SG_NEXT_CMD_LEN:
998 result = get_user(val, ip);
999 if (result)
1000 return result;
1001 if (val > SG_MAX_CDB_SIZE)
1002 return -ENOMEM;
1003 sfp->next_cmd_len = (val > 0) ? val : 0;
1004 return 0;
1005 case SG_GET_VERSION_NUM:
1006 return put_user(sg_version_num, ip);
1007 case SG_GET_ACCESS_COUNT:
1008 /* faked - we don't have a real access count anymore */
1009 val = (sdp->device ? 1 : 0);
1010 return put_user(val, ip);
1011 case SG_GET_REQUEST_TABLE:
1012 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
1013 return -EFAULT;
1014 else {
1015 sg_req_info_t *rinfo;
1016 unsigned int ms;
1017
1018 rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
1019 GFP_KERNEL);
1020 if (!rinfo)
1021 return -ENOMEM;
1022 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1023 for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
1024 ++val, srp = srp ? srp->nextrp : srp) {
1025 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
1026 if (srp) {
1027 rinfo[val].req_state = srp->done + 1;
1028 rinfo[val].problem =
1029 srp->header.masked_status &
1030 srp->header.host_status &
1031 srp->header.driver_status;
1032 if (srp->done)
1033 rinfo[val].duration =
1034 srp->header.duration;
1035 else {
1036 ms = jiffies_to_msecs(jiffies);
1037 rinfo[val].duration =
1038 (ms > srp->header.duration) ?
1039 (ms - srp->header.duration) : 0;
1040 }
1041 rinfo[val].orphan = srp->orphan;
1042 rinfo[val].sg_io_owned =
1043 srp->sg_io_owned;
1044 rinfo[val].pack_id =
1045 srp->header.pack_id;
1046 rinfo[val].usr_ptr =
1047 srp->header.usr_ptr;
1048 }
1049 }
1050 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1051 result = __copy_to_user(p, rinfo,
1052 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1053 result = result ? -EFAULT : 0;
1054 kfree(rinfo);
1055 return result;
1056 }
1057 case SG_EMULATED_HOST:
1058 if (atomic_read(&sdp->detaching))
1059 return -ENODEV;
1060 return put_user(sdp->device->host->hostt->emulated, ip);
1061 case SCSI_IOCTL_SEND_COMMAND:
1062 if (atomic_read(&sdp->detaching))
1063 return -ENODEV;
1064 if (read_only) {
1065 unsigned char opcode = WRITE_6;
1066 Scsi_Ioctl_Command __user *siocp = p;
1067
1068 if (copy_from_user(&opcode, siocp->data, 1))
1069 return -EFAULT;
1070 if (sg_allow_access(filp, &opcode))
1071 return -EPERM;
1072 }
1073 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1074 case SG_SET_DEBUG:
1075 result = get_user(val, ip);
1076 if (result)
1077 return result;
1078 sdp->sgdebug = (char) val;
1079 return 0;
1080 case BLKSECTGET:
1081 return put_user(max_sectors_bytes(sdp->device->request_queue),
1082 ip);
1083 case BLKTRACESETUP:
1084 return blk_trace_setup(sdp->device->request_queue,
1085 sdp->disk->disk_name,
1086 MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1087 NULL,
1088 (char *)arg);
1089 case BLKTRACESTART:
1090 return blk_trace_startstop(sdp->device->request_queue, 1);
1091 case BLKTRACESTOP:
1092 return blk_trace_startstop(sdp->device->request_queue, 0);
1093 case BLKTRACETEARDOWN:
1094 return blk_trace_remove(sdp->device->request_queue);
1095 case SCSI_IOCTL_GET_IDLUN:
1096 case SCSI_IOCTL_GET_BUS_NUMBER:
1097 case SCSI_IOCTL_PROBE_HOST:
1098 case SG_GET_TRANSFORM:
1099 case SG_SCSI_RESET:
1100 if (atomic_read(&sdp->detaching))
1101 return -ENODEV;
1102 break;
1103 default:
1104 if (read_only)
1105 return -EPERM; /* don't know so take safe approach */
1106 break;
1107 }
1108
1109 result = scsi_ioctl_block_when_processing_errors(sdp->device,
1110 cmd_in, filp->f_flags & O_NDELAY);
1111 if (result)
1112 return result;
1113 return scsi_ioctl(sdp->device, cmd_in, p);
1114}
1115
1116#ifdef CONFIG_COMPAT
1117static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1118{
1119 Sg_device *sdp;
1120 Sg_fd *sfp;
1121 struct scsi_device *sdev;
1122
1123 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1124 return -ENXIO;
1125
1126 sdev = sdp->device;
1127 if (sdev->host->hostt->compat_ioctl) {
1128 int ret;
1129
1130 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1131
1132 return ret;
1133 }
1134
1135 return -ENOIOCTLCMD;
1136}
1137#endif
1138
1139static unsigned int
1140sg_poll(struct file *filp, poll_table * wait)
1141{
1142 unsigned int res = 0;
1143 Sg_device *sdp;
1144 Sg_fd *sfp;
1145 Sg_request *srp;
1146 int count = 0;
1147 unsigned long iflags;
1148
1149 sfp = filp->private_data;
1150 if (!sfp)
1151 return POLLERR;
1152 sdp = sfp->parentdp;
1153 if (!sdp)
1154 return POLLERR;
1155 poll_wait(filp, &sfp->read_wait, wait);
1156 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1157 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1158 /* if any read waiting, flag it */
1159 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1160 res = POLLIN | POLLRDNORM;
1161 ++count;
1162 }
1163 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1164
1165 if (atomic_read(&sdp->detaching))
1166 res |= POLLHUP;
1167 else if (!sfp->cmd_q) {
1168 if (0 == count)
1169 res |= POLLOUT | POLLWRNORM;
1170 } else if (count < SG_MAX_QUEUE)
1171 res |= POLLOUT | POLLWRNORM;
1172 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1173 "sg_poll: res=0x%x\n", (int) res));
1174 return res;
1175}
1176
1177static int
1178sg_fasync(int fd, struct file *filp, int mode)
1179{
1180 Sg_device *sdp;
1181 Sg_fd *sfp;
1182
1183 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1184 return -ENXIO;
1185 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1186 "sg_fasync: mode=%d\n", mode));
1187
1188 return fasync_helper(fd, filp, mode, &sfp->async_qp);
1189}
1190
1191static int
1192sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1193{
1194 Sg_fd *sfp;
1195 unsigned long offset, len, sa;
1196 Sg_scatter_hold *rsv_schp;
1197 int k, length;
1198
1199 if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1200 return VM_FAULT_SIGBUS;
1201 rsv_schp = &sfp->reserve;
1202 offset = vmf->pgoff << PAGE_SHIFT;
1203 if (offset >= rsv_schp->bufflen)
1204 return VM_FAULT_SIGBUS;
1205 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1206 "sg_vma_fault: offset=%lu, scatg=%d\n",
1207 offset, rsv_schp->k_use_sg));
1208 sa = vma->vm_start;
1209 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1210 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1211 len = vma->vm_end - sa;
1212 len = (len < length) ? len : length;
1213 if (offset < len) {
1214 struct page *page = nth_page(rsv_schp->pages[k],
1215 offset >> PAGE_SHIFT);
1216 get_page(page); /* increment page count */
1217 vmf->page = page;
1218 return 0; /* success */
1219 }
1220 sa += len;
1221 offset -= len;
1222 }
1223
1224 return VM_FAULT_SIGBUS;
1225}
1226
1227static const struct vm_operations_struct sg_mmap_vm_ops = {
1228 .fault = sg_vma_fault,
1229};
1230
1231static int
1232sg_mmap(struct file *filp, struct vm_area_struct *vma)
1233{
1234 Sg_fd *sfp;
1235 unsigned long req_sz, len, sa;
1236 Sg_scatter_hold *rsv_schp;
1237 int k, length;
1238
1239 if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1240 return -ENXIO;
1241 req_sz = vma->vm_end - vma->vm_start;
1242 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1243 "sg_mmap starting, vm_start=%p, len=%d\n",
1244 (void *) vma->vm_start, (int) req_sz));
1245 if (vma->vm_pgoff)
1246 return -EINVAL; /* want no offset */
1247 rsv_schp = &sfp->reserve;
1248 if (req_sz > rsv_schp->bufflen)
1249 return -ENOMEM; /* cannot map more than reserved buffer */
1250
1251 sa = vma->vm_start;
1252 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1253 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1254 len = vma->vm_end - sa;
1255 len = (len < length) ? len : length;
1256 sa += len;
1257 }
1258
1259 sfp->mmap_called = 1;
1260 vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
1261 vma->vm_private_data = sfp;
1262 vma->vm_ops = &sg_mmap_vm_ops;
1263 return 0;
1264}
1265
1266static void
1267sg_rq_end_io_usercontext(struct work_struct *work)
1268{
1269 struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1270 struct sg_fd *sfp = srp->parentfp;
1271
1272 sg_finish_rem_req(srp);
1273 kref_put(&sfp->f_ref, sg_remove_sfp);
1274}
1275
1276/*
1277 * This function is a "bottom half" handler that is called by the mid
1278 * level when a command is completed (or has failed).
1279 */
1280static void
1281sg_rq_end_io(struct request *rq, int uptodate)
1282{
1283 struct sg_request *srp = rq->end_io_data;
1284 Sg_device *sdp;
1285 Sg_fd *sfp;
1286 unsigned long iflags;
1287 unsigned int ms;
1288 char *sense;
1289 int result, resid, done = 1;
1290
1291 if (WARN_ON(srp->done != 0))
1292 return;
1293
1294 sfp = srp->parentfp;
1295 if (WARN_ON(sfp == NULL))
1296 return;
1297
1298 sdp = sfp->parentdp;
1299 if (unlikely(atomic_read(&sdp->detaching)))
1300 pr_info("%s: device detaching\n", __func__);
1301
1302 sense = rq->sense;
1303 result = rq->errors;
1304 resid = rq->resid_len;
1305
1306 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1307 "sg_cmd_done: pack_id=%d, res=0x%x\n",
1308 srp->header.pack_id, result));
1309 srp->header.resid = resid;
1310 ms = jiffies_to_msecs(jiffies);
1311 srp->header.duration = (ms > srp->header.duration) ?
1312 (ms - srp->header.duration) : 0;
1313 if (0 != result) {
1314 struct scsi_sense_hdr sshdr;
1315
1316 srp->header.status = 0xff & result;
1317 srp->header.masked_status = status_byte(result);
1318 srp->header.msg_status = msg_byte(result);
1319 srp->header.host_status = host_byte(result);
1320 srp->header.driver_status = driver_byte(result);
1321 if ((sdp->sgdebug > 0) &&
1322 ((CHECK_CONDITION == srp->header.masked_status) ||
1323 (COMMAND_TERMINATED == srp->header.masked_status)))
1324 __scsi_print_sense(sdp->device, __func__, sense,
1325 SCSI_SENSE_BUFFERSIZE);
1326
1327 /* Following if statement is a patch supplied by Eric Youngdale */
1328 if (driver_byte(result) != 0
1329 && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1330 && !scsi_sense_is_deferred(&sshdr)
1331 && sshdr.sense_key == UNIT_ATTENTION
1332 && sdp->device->removable) {
1333 /* Detected possible disc change. Set the bit - this */
1334 /* may be used if there are filesystems using this device */
1335 sdp->device->changed = 1;
1336 }
1337 }
1338 /* Rely on write phase to clean out srp status values, so no "else" */
1339
1340 /*
1341 * Free the request as soon as it is complete so that its resources
1342 * can be reused without waiting for userspace to read() the
1343 * result. But keep the associated bio (if any) around until
1344 * blk_rq_unmap_user() can be called from user context.
1345 */
1346 srp->rq = NULL;
1347 if (rq->cmd != rq->__cmd)
1348 kfree(rq->cmd);
1349 __blk_put_request(rq->q, rq);
1350
1351 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1352 if (unlikely(srp->orphan)) {
1353 if (sfp->keep_orphan)
1354 srp->sg_io_owned = 0;
1355 else
1356 done = 0;
1357 }
1358 srp->done = done;
1359 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1360
1361 if (likely(done)) {
1362 /* Now wake up any sg_read() that is waiting for this
1363 * packet.
1364 */
1365 wake_up_interruptible(&sfp->read_wait);
1366 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1367 kref_put(&sfp->f_ref, sg_remove_sfp);
1368 } else {
1369 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1370 schedule_work(&srp->ew.work);
1371 }
1372}
1373
1374static const struct file_operations sg_fops = {
1375 .owner = THIS_MODULE,
1376 .read = sg_read,
1377 .write = sg_write,
1378 .poll = sg_poll,
1379 .unlocked_ioctl = sg_ioctl,
1380#ifdef CONFIG_COMPAT
1381 .compat_ioctl = sg_compat_ioctl,
1382#endif
1383 .open = sg_open,
1384 .mmap = sg_mmap,
1385 .release = sg_release,
1386 .fasync = sg_fasync,
1387 .llseek = no_llseek,
1388};
1389
1390static struct class *sg_sysfs_class;
1391
1392static int sg_sysfs_valid = 0;
1393
1394static Sg_device *
1395sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1396{
1397 struct request_queue *q = scsidp->request_queue;
1398 Sg_device *sdp;
1399 unsigned long iflags;
1400 int error;
1401 u32 k;
1402
1403 sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1404 if (!sdp) {
1405 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1406 "failure\n", __func__);
1407 return ERR_PTR(-ENOMEM);
1408 }
1409
1410 idr_preload(GFP_KERNEL);
1411 write_lock_irqsave(&sg_index_lock, iflags);
1412
1413 error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1414 if (error < 0) {
1415 if (error == -ENOSPC) {
1416 sdev_printk(KERN_WARNING, scsidp,
1417 "Unable to attach sg device type=%d, minor number exceeds %d\n",
1418 scsidp->type, SG_MAX_DEVS - 1);
1419 error = -ENODEV;
1420 } else {
1421 sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1422 "allocation Sg_device failure: %d\n",
1423 __func__, error);
1424 }
1425 goto out_unlock;
1426 }
1427 k = error;
1428
1429 SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1430 "sg_alloc: dev=%d \n", k));
1431 sprintf(disk->disk_name, "sg%d", k);
1432 disk->first_minor = k;
1433 sdp->disk = disk;
1434 sdp->device = scsidp;
1435 mutex_init(&sdp->open_rel_lock);
1436 INIT_LIST_HEAD(&sdp->sfds);
1437 init_waitqueue_head(&sdp->open_wait);
1438 atomic_set(&sdp->detaching, 0);
1439 rwlock_init(&sdp->sfd_lock);
1440 sdp->sg_tablesize = queue_max_segments(q);
1441 sdp->index = k;
1442 kref_init(&sdp->d_ref);
1443 error = 0;
1444
1445out_unlock:
1446 write_unlock_irqrestore(&sg_index_lock, iflags);
1447 idr_preload_end();
1448
1449 if (error) {
1450 kfree(sdp);
1451 return ERR_PTR(error);
1452 }
1453 return sdp;
1454}
1455
1456static int
1457sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
1458{
1459 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1460 struct gendisk *disk;
1461 Sg_device *sdp = NULL;
1462 struct cdev * cdev = NULL;
1463 int error;
1464 unsigned long iflags;
1465
1466 disk = alloc_disk(1);
1467 if (!disk) {
1468 pr_warn("%s: alloc_disk failed\n", __func__);
1469 return -ENOMEM;
1470 }
1471 disk->major = SCSI_GENERIC_MAJOR;
1472
1473 error = -ENOMEM;
1474 cdev = cdev_alloc();
1475 if (!cdev) {
1476 pr_warn("%s: cdev_alloc failed\n", __func__);
1477 goto out;
1478 }
1479 cdev->owner = THIS_MODULE;
1480 cdev->ops = &sg_fops;
1481
1482 sdp = sg_alloc(disk, scsidp);
1483 if (IS_ERR(sdp)) {
1484 pr_warn("%s: sg_alloc failed\n", __func__);
1485 error = PTR_ERR(sdp);
1486 goto out;
1487 }
1488
1489 error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1490 if (error)
1491 goto cdev_add_err;
1492
1493 sdp->cdev = cdev;
1494 if (sg_sysfs_valid) {
1495 struct device *sg_class_member;
1496
1497 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1498 MKDEV(SCSI_GENERIC_MAJOR,
1499 sdp->index),
1500 sdp, "%s", disk->disk_name);
1501 if (IS_ERR(sg_class_member)) {
1502 pr_err("%s: device_create failed\n", __func__);
1503 error = PTR_ERR(sg_class_member);
1504 goto cdev_add_err;
1505 }
1506 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1507 &sg_class_member->kobj, "generic");
1508 if (error)
1509 pr_err("%s: unable to make symlink 'generic' back "
1510 "to sg%d\n", __func__, sdp->index);
1511 } else
1512 pr_warn("%s: sg_sys Invalid\n", __func__);
1513
1514 sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1515 "type %d\n", sdp->index, scsidp->type);
1516
1517 dev_set_drvdata(cl_dev, sdp);
1518
1519 return 0;
1520
1521cdev_add_err:
1522 write_lock_irqsave(&sg_index_lock, iflags);
1523 idr_remove(&sg_index_idr, sdp->index);
1524 write_unlock_irqrestore(&sg_index_lock, iflags);
1525 kfree(sdp);
1526
1527out:
1528 put_disk(disk);
1529 if (cdev)
1530 cdev_del(cdev);
1531 return error;
1532}
1533
1534static void
1535sg_device_destroy(struct kref *kref)
1536{
1537 struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1538 unsigned long flags;
1539
1540 /* CAUTION! Note that the device can still be found via idr_find()
1541 * even though the refcount is 0. Therefore, do idr_remove() BEFORE
1542 * any other cleanup.
1543 */
1544
1545 write_lock_irqsave(&sg_index_lock, flags);
1546 idr_remove(&sg_index_idr, sdp->index);
1547 write_unlock_irqrestore(&sg_index_lock, flags);
1548
1549 SCSI_LOG_TIMEOUT(3,
1550 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1551
1552 put_disk(sdp->disk);
1553 kfree(sdp);
1554}
1555
1556static void
1557sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
1558{
1559 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1560 Sg_device *sdp = dev_get_drvdata(cl_dev);
1561 unsigned long iflags;
1562 Sg_fd *sfp;
1563 int val;
1564
1565 if (!sdp)
1566 return;
1567 /* want sdp->detaching non-zero as soon as possible */
1568 val = atomic_inc_return(&sdp->detaching);
1569 if (val > 1)
1570 return; /* only want to do following once per device */
1571
1572 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1573 "%s\n", __func__));
1574
1575 read_lock_irqsave(&sdp->sfd_lock, iflags);
1576 list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1577 wake_up_interruptible_all(&sfp->read_wait);
1578 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1579 }
1580 wake_up_interruptible_all(&sdp->open_wait);
1581 read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1582
1583 sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1584 device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1585 cdev_del(sdp->cdev);
1586 sdp->cdev = NULL;
1587
1588 kref_put(&sdp->d_ref, sg_device_destroy);
1589}
1590
1591module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1592module_param_named(def_reserved_size, def_reserved_size, int,
1593 S_IRUGO | S_IWUSR);
1594module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1595
1596MODULE_AUTHOR("Douglas Gilbert");
1597MODULE_DESCRIPTION("SCSI generic (sg) driver");
1598MODULE_LICENSE("GPL");
1599MODULE_VERSION(SG_VERSION_STR);
1600MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1601
1602MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1603 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1604MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1605MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1606
1607static int __init
1608init_sg(void)
1609{
1610 int rc;
1611
1612 if (scatter_elem_sz < PAGE_SIZE) {
1613 scatter_elem_sz = PAGE_SIZE;
1614 scatter_elem_sz_prev = scatter_elem_sz;
1615 }
1616 if (def_reserved_size >= 0)
1617 sg_big_buff = def_reserved_size;
1618 else
1619 def_reserved_size = sg_big_buff;
1620
1621 rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1622 SG_MAX_DEVS, "sg");
1623 if (rc)
1624 return rc;
1625 sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1626 if ( IS_ERR(sg_sysfs_class) ) {
1627 rc = PTR_ERR(sg_sysfs_class);
1628 goto err_out;
1629 }
1630 sg_sysfs_valid = 1;
1631 rc = scsi_register_interface(&sg_interface);
1632 if (0 == rc) {
1633#ifdef CONFIG_SCSI_PROC_FS
1634 sg_proc_init();
1635#endif /* CONFIG_SCSI_PROC_FS */
1636 return 0;
1637 }
1638 class_destroy(sg_sysfs_class);
1639err_out:
1640 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1641 return rc;
1642}
1643
1644static void __exit
1645exit_sg(void)
1646{
1647#ifdef CONFIG_SCSI_PROC_FS
1648 sg_proc_cleanup();
1649#endif /* CONFIG_SCSI_PROC_FS */
1650 scsi_unregister_interface(&sg_interface);
1651 class_destroy(sg_sysfs_class);
1652 sg_sysfs_valid = 0;
1653 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1654 SG_MAX_DEVS);
1655 idr_destroy(&sg_index_idr);
1656}
1657
1658static int
1659sg_start_req(Sg_request *srp, unsigned char *cmd)
1660{
1661 int res;
1662 struct request *rq;
1663 Sg_fd *sfp = srp->parentfp;
1664 sg_io_hdr_t *hp = &srp->header;
1665 int dxfer_len = (int) hp->dxfer_len;
1666 int dxfer_dir = hp->dxfer_direction;
1667 unsigned int iov_count = hp->iovec_count;
1668 Sg_scatter_hold *req_schp = &srp->data;
1669 Sg_scatter_hold *rsv_schp = &sfp->reserve;
1670 struct request_queue *q = sfp->parentdp->device->request_queue;
1671 struct rq_map_data *md, map_data;
1672 int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1673 unsigned char *long_cmdp = NULL;
1674
1675 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1676 "sg_start_req: dxfer_len=%d\n",
1677 dxfer_len));
1678
1679 if (hp->cmd_len > BLK_MAX_CDB) {
1680 long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
1681 if (!long_cmdp)
1682 return -ENOMEM;
1683 }
1684
1685 /*
1686 * NOTE
1687 *
1688 * With scsi-mq enabled, there are a fixed number of preallocated
1689 * requests equal in number to shost->can_queue. If all of the
1690 * preallocated requests are already in use, then using GFP_ATOMIC with
1691 * blk_get_request() will return -EWOULDBLOCK, whereas using GFP_KERNEL
1692 * will cause blk_get_request() to sleep until an active command
1693 * completes, freeing up a request. Neither option is ideal, but
1694 * GFP_KERNEL is the better choice to prevent userspace from getting an
1695 * unexpected EWOULDBLOCK.
1696 *
1697 * With scsi-mq disabled, blk_get_request() with GFP_KERNEL usually
1698 * does not sleep except under memory pressure.
1699 */
1700 rq = blk_get_request(q, rw, GFP_KERNEL);
1701 if (IS_ERR(rq)) {
1702 kfree(long_cmdp);
1703 return PTR_ERR(rq);
1704 }
1705
1706 blk_rq_set_block_pc(rq);
1707
1708 if (hp->cmd_len > BLK_MAX_CDB)
1709 rq->cmd = long_cmdp;
1710 memcpy(rq->cmd, cmd, hp->cmd_len);
1711 rq->cmd_len = hp->cmd_len;
1712
1713 srp->rq = rq;
1714 rq->end_io_data = srp;
1715 rq->sense = srp->sense_b;
1716 rq->retries = SG_DEFAULT_RETRIES;
1717
1718 if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1719 return 0;
1720
1721 if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1722 dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1723 !sfp->parentdp->device->host->unchecked_isa_dma &&
1724 blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1725 md = NULL;
1726 else
1727 md = &map_data;
1728
1729 if (md) {
1730 if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen)
1731 sg_link_reserve(sfp, srp, dxfer_len);
1732 else {
1733 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1734 if (res)
1735 return res;
1736 }
1737
1738 md->pages = req_schp->pages;
1739 md->page_order = req_schp->page_order;
1740 md->nr_entries = req_schp->k_use_sg;
1741 md->offset = 0;
1742 md->null_mapped = hp->dxferp ? 0 : 1;
1743 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1744 md->from_user = 1;
1745 else
1746 md->from_user = 0;
1747 }
1748
1749 if (iov_count) {
1750 struct iovec *iov = NULL;
1751 struct iov_iter i;
1752
1753 res = import_iovec(rw, hp->dxferp, iov_count, 0, &iov, &i);
1754 if (res < 0)
1755 return res;
1756
1757 iov_iter_truncate(&i, hp->dxfer_len);
1758 if (!iov_iter_count(&i)) {
1759 kfree(iov);
1760 return -EINVAL;
1761 }
1762
1763 res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
1764 kfree(iov);
1765 } else
1766 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1767 hp->dxfer_len, GFP_ATOMIC);
1768
1769 if (!res) {
1770 srp->bio = rq->bio;
1771
1772 if (!md) {
1773 req_schp->dio_in_use = 1;
1774 hp->info |= SG_INFO_DIRECT_IO;
1775 }
1776 }
1777 return res;
1778}
1779
1780static int
1781sg_finish_rem_req(Sg_request *srp)
1782{
1783 int ret = 0;
1784
1785 Sg_fd *sfp = srp->parentfp;
1786 Sg_scatter_hold *req_schp = &srp->data;
1787
1788 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1789 "sg_finish_rem_req: res_used=%d\n",
1790 (int) srp->res_used));
1791 if (srp->bio)
1792 ret = blk_rq_unmap_user(srp->bio);
1793
1794 if (srp->rq) {
1795 if (srp->rq->cmd != srp->rq->__cmd)
1796 kfree(srp->rq->cmd);
1797 blk_put_request(srp->rq);
1798 }
1799
1800 if (srp->res_used)
1801 sg_unlink_reserve(sfp, srp);
1802 else
1803 sg_remove_scat(sfp, req_schp);
1804
1805 sg_remove_request(sfp, srp);
1806
1807 return ret;
1808}
1809
1810static int
1811sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1812{
1813 int sg_bufflen = tablesize * sizeof(struct page *);
1814 gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1815
1816 schp->pages = kzalloc(sg_bufflen, gfp_flags);
1817 if (!schp->pages)
1818 return -ENOMEM;
1819 schp->sglist_len = sg_bufflen;
1820 return tablesize; /* number of scat_gath elements allocated */
1821}
1822
1823static int
1824sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1825{
1826 int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1827 int sg_tablesize = sfp->parentdp->sg_tablesize;
1828 int blk_size = buff_size, order;
1829 gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1830
1831 if (blk_size < 0)
1832 return -EFAULT;
1833 if (0 == blk_size)
1834 ++blk_size; /* don't know why */
1835 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1836 blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1837 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1838 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1839 buff_size, blk_size));
1840
1841 /* N.B. ret_sz carried into this block ... */
1842 mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1843 if (mx_sc_elems < 0)
1844 return mx_sc_elems; /* most likely -ENOMEM */
1845
1846 num = scatter_elem_sz;
1847 if (unlikely(num != scatter_elem_sz_prev)) {
1848 if (num < PAGE_SIZE) {
1849 scatter_elem_sz = PAGE_SIZE;
1850 scatter_elem_sz_prev = PAGE_SIZE;
1851 } else
1852 scatter_elem_sz_prev = num;
1853 }
1854
1855 if (sfp->low_dma)
1856 gfp_mask |= GFP_DMA;
1857
1858 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1859 gfp_mask |= __GFP_ZERO;
1860
1861 order = get_order(num);
1862retry:
1863 ret_sz = 1 << (PAGE_SHIFT + order);
1864
1865 for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1866 k++, rem_sz -= ret_sz) {
1867
1868 num = (rem_sz > scatter_elem_sz_prev) ?
1869 scatter_elem_sz_prev : rem_sz;
1870
1871 schp->pages[k] = alloc_pages(gfp_mask, order);
1872 if (!schp->pages[k])
1873 goto out;
1874
1875 if (num == scatter_elem_sz_prev) {
1876 if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1877 scatter_elem_sz = ret_sz;
1878 scatter_elem_sz_prev = ret_sz;
1879 }
1880 }
1881
1882 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1883 "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1884 k, num, ret_sz));
1885 } /* end of for loop */
1886
1887 schp->page_order = order;
1888 schp->k_use_sg = k;
1889 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1890 "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1891 k, rem_sz));
1892
1893 schp->bufflen = blk_size;
1894 if (rem_sz > 0) /* must have failed */
1895 return -ENOMEM;
1896 return 0;
1897out:
1898 for (i = 0; i < k; i++)
1899 __free_pages(schp->pages[i], order);
1900
1901 if (--order >= 0)
1902 goto retry;
1903
1904 return -ENOMEM;
1905}
1906
1907static void
1908sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1909{
1910 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1911 "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1912 if (schp->pages && schp->sglist_len > 0) {
1913 if (!schp->dio_in_use) {
1914 int k;
1915
1916 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1917 SCSI_LOG_TIMEOUT(5,
1918 sg_printk(KERN_INFO, sfp->parentdp,
1919 "sg_remove_scat: k=%d, pg=0x%p\n",
1920 k, schp->pages[k]));
1921 __free_pages(schp->pages[k], schp->page_order);
1922 }
1923
1924 kfree(schp->pages);
1925 }
1926 }
1927 memset(schp, 0, sizeof (*schp));
1928}
1929
1930static int
1931sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1932{
1933 Sg_scatter_hold *schp = &srp->data;
1934 int k, num;
1935
1936 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1937 "sg_read_oxfer: num_read_xfer=%d\n",
1938 num_read_xfer));
1939 if ((!outp) || (num_read_xfer <= 0))
1940 return 0;
1941
1942 num = 1 << (PAGE_SHIFT + schp->page_order);
1943 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1944 if (num > num_read_xfer) {
1945 if (__copy_to_user(outp, page_address(schp->pages[k]),
1946 num_read_xfer))
1947 return -EFAULT;
1948 break;
1949 } else {
1950 if (__copy_to_user(outp, page_address(schp->pages[k]),
1951 num))
1952 return -EFAULT;
1953 num_read_xfer -= num;
1954 if (num_read_xfer <= 0)
1955 break;
1956 outp += num;
1957 }
1958 }
1959
1960 return 0;
1961}
1962
1963static void
1964sg_build_reserve(Sg_fd * sfp, int req_size)
1965{
1966 Sg_scatter_hold *schp = &sfp->reserve;
1967
1968 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1969 "sg_build_reserve: req_size=%d\n", req_size));
1970 do {
1971 if (req_size < PAGE_SIZE)
1972 req_size = PAGE_SIZE;
1973 if (0 == sg_build_indirect(schp, sfp, req_size))
1974 return;
1975 else
1976 sg_remove_scat(sfp, schp);
1977 req_size >>= 1; /* divide by 2 */
1978 } while (req_size > (PAGE_SIZE / 2));
1979}
1980
1981static void
1982sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1983{
1984 Sg_scatter_hold *req_schp = &srp->data;
1985 Sg_scatter_hold *rsv_schp = &sfp->reserve;
1986 int k, num, rem;
1987
1988 srp->res_used = 1;
1989 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1990 "sg_link_reserve: size=%d\n", size));
1991 rem = size;
1992
1993 num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1994 for (k = 0; k < rsv_schp->k_use_sg; k++) {
1995 if (rem <= num) {
1996 req_schp->k_use_sg = k + 1;
1997 req_schp->sglist_len = rsv_schp->sglist_len;
1998 req_schp->pages = rsv_schp->pages;
1999
2000 req_schp->bufflen = size;
2001 req_schp->page_order = rsv_schp->page_order;
2002 break;
2003 } else
2004 rem -= num;
2005 }
2006
2007 if (k >= rsv_schp->k_use_sg)
2008 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2009 "sg_link_reserve: BAD size\n"));
2010}
2011
2012static void
2013sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2014{
2015 Sg_scatter_hold *req_schp = &srp->data;
2016
2017 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2018 "sg_unlink_reserve: req->k_use_sg=%d\n",
2019 (int) req_schp->k_use_sg));
2020 req_schp->k_use_sg = 0;
2021 req_schp->bufflen = 0;
2022 req_schp->pages = NULL;
2023 req_schp->page_order = 0;
2024 req_schp->sglist_len = 0;
2025 sfp->save_scat_len = 0;
2026 srp->res_used = 0;
2027}
2028
2029static Sg_request *
2030sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2031{
2032 Sg_request *resp;
2033 unsigned long iflags;
2034
2035 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2036 for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2037 /* look for requests that are ready + not SG_IO owned */
2038 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2039 ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2040 resp->done = 2; /* guard against other readers */
2041 break;
2042 }
2043 }
2044 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2045 return resp;
2046}
2047
2048/* always adds to end of list */
2049static Sg_request *
2050sg_add_request(Sg_fd * sfp)
2051{
2052 int k;
2053 unsigned long iflags;
2054 Sg_request *resp;
2055 Sg_request *rp = sfp->req_arr;
2056
2057 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2058 resp = sfp->headrp;
2059 if (!resp) {
2060 memset(rp, 0, sizeof (Sg_request));
2061 rp->parentfp = sfp;
2062 resp = rp;
2063 sfp->headrp = resp;
2064 } else {
2065 if (0 == sfp->cmd_q)
2066 resp = NULL; /* command queuing disallowed */
2067 else {
2068 for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2069 if (!rp->parentfp)
2070 break;
2071 }
2072 if (k < SG_MAX_QUEUE) {
2073 memset(rp, 0, sizeof (Sg_request));
2074 rp->parentfp = sfp;
2075 while (resp->nextrp)
2076 resp = resp->nextrp;
2077 resp->nextrp = rp;
2078 resp = rp;
2079 } else
2080 resp = NULL;
2081 }
2082 }
2083 if (resp) {
2084 resp->nextrp = NULL;
2085 resp->header.duration = jiffies_to_msecs(jiffies);
2086 }
2087 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2088 return resp;
2089}
2090
2091/* Return of 1 for found; 0 for not found */
2092static int
2093sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2094{
2095 Sg_request *prev_rp;
2096 Sg_request *rp;
2097 unsigned long iflags;
2098 int res = 0;
2099
2100 if ((!sfp) || (!srp) || (!sfp->headrp))
2101 return res;
2102 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2103 prev_rp = sfp->headrp;
2104 if (srp == prev_rp) {
2105 sfp->headrp = prev_rp->nextrp;
2106 prev_rp->parentfp = NULL;
2107 res = 1;
2108 } else {
2109 while ((rp = prev_rp->nextrp)) {
2110 if (srp == rp) {
2111 prev_rp->nextrp = rp->nextrp;
2112 rp->parentfp = NULL;
2113 res = 1;
2114 break;
2115 }
2116 prev_rp = rp;
2117 }
2118 }
2119 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2120 return res;
2121}
2122
2123static Sg_fd *
2124sg_add_sfp(Sg_device * sdp)
2125{
2126 Sg_fd *sfp;
2127 unsigned long iflags;
2128 int bufflen;
2129
2130 sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2131 if (!sfp)
2132 return ERR_PTR(-ENOMEM);
2133
2134 init_waitqueue_head(&sfp->read_wait);
2135 rwlock_init(&sfp->rq_list_lock);
2136
2137 kref_init(&sfp->f_ref);
2138 sfp->timeout = SG_DEFAULT_TIMEOUT;
2139 sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2140 sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2141 sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2142 sdp->device->host->unchecked_isa_dma : 1;
2143 sfp->cmd_q = SG_DEF_COMMAND_Q;
2144 sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2145 sfp->parentdp = sdp;
2146 write_lock_irqsave(&sdp->sfd_lock, iflags);
2147 if (atomic_read(&sdp->detaching)) {
2148 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2149 return ERR_PTR(-ENODEV);
2150 }
2151 list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2152 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2153 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2154 "sg_add_sfp: sfp=0x%p\n", sfp));
2155 if (unlikely(sg_big_buff != def_reserved_size))
2156 sg_big_buff = def_reserved_size;
2157
2158 bufflen = min_t(int, sg_big_buff,
2159 max_sectors_bytes(sdp->device->request_queue));
2160 sg_build_reserve(sfp, bufflen);
2161 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2162 "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2163 sfp->reserve.bufflen,
2164 sfp->reserve.k_use_sg));
2165
2166 kref_get(&sdp->d_ref);
2167 __module_get(THIS_MODULE);
2168 return sfp;
2169}
2170
2171static void
2172sg_remove_sfp_usercontext(struct work_struct *work)
2173{
2174 struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2175 struct sg_device *sdp = sfp->parentdp;
2176
2177 /* Cleanup any responses which were never read(). */
2178 while (sfp->headrp)
2179 sg_finish_rem_req(sfp->headrp);
2180
2181 if (sfp->reserve.bufflen > 0) {
2182 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2183 "sg_remove_sfp: bufflen=%d, k_use_sg=%d\n",
2184 (int) sfp->reserve.bufflen,
2185 (int) sfp->reserve.k_use_sg));
2186 sg_remove_scat(sfp, &sfp->reserve);
2187 }
2188
2189 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2190 "sg_remove_sfp: sfp=0x%p\n", sfp));
2191 kfree(sfp);
2192
2193 scsi_device_put(sdp->device);
2194 kref_put(&sdp->d_ref, sg_device_destroy);
2195 module_put(THIS_MODULE);
2196}
2197
2198static void
2199sg_remove_sfp(struct kref *kref)
2200{
2201 struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2202 struct sg_device *sdp = sfp->parentdp;
2203 unsigned long iflags;
2204
2205 write_lock_irqsave(&sdp->sfd_lock, iflags);
2206 list_del(&sfp->sfd_siblings);
2207 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2208
2209 INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2210 schedule_work(&sfp->ew.work);
2211}
2212
2213static int
2214sg_res_in_use(Sg_fd * sfp)
2215{
2216 const Sg_request *srp;
2217 unsigned long iflags;
2218
2219 read_lock_irqsave(&sfp->rq_list_lock, iflags);
2220 for (srp = sfp->headrp; srp; srp = srp->nextrp)
2221 if (srp->res_used)
2222 break;
2223 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2224 return srp ? 1 : 0;
2225}
2226
2227#ifdef CONFIG_SCSI_PROC_FS
2228static int
2229sg_idr_max_id(int id, void *p, void *data)
2230{
2231 int *k = data;
2232
2233 if (*k < id)
2234 *k = id;
2235
2236 return 0;
2237}
2238
2239static int
2240sg_last_dev(void)
2241{
2242 int k = -1;
2243 unsigned long iflags;
2244
2245 read_lock_irqsave(&sg_index_lock, iflags);
2246 idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2247 read_unlock_irqrestore(&sg_index_lock, iflags);
2248 return k + 1; /* origin 1 */
2249}
2250#endif
2251
2252/* must be called with sg_index_lock held */
2253static Sg_device *sg_lookup_dev(int dev)
2254{
2255 return idr_find(&sg_index_idr, dev);
2256}
2257
2258static Sg_device *
2259sg_get_dev(int dev)
2260{
2261 struct sg_device *sdp;
2262 unsigned long flags;
2263
2264 read_lock_irqsave(&sg_index_lock, flags);
2265 sdp = sg_lookup_dev(dev);
2266 if (!sdp)
2267 sdp = ERR_PTR(-ENXIO);
2268 else if (atomic_read(&sdp->detaching)) {
2269 /* If sdp->detaching, then the refcount may already be 0, in
2270 * which case it would be a bug to do kref_get().
2271 */
2272 sdp = ERR_PTR(-ENODEV);
2273 } else
2274 kref_get(&sdp->d_ref);
2275 read_unlock_irqrestore(&sg_index_lock, flags);
2276
2277 return sdp;
2278}
2279
2280#ifdef CONFIG_SCSI_PROC_FS
2281
2282static struct proc_dir_entry *sg_proc_sgp = NULL;
2283
2284static char sg_proc_sg_dirname[] = "scsi/sg";
2285
2286static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2287
2288static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2289static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2290 size_t count, loff_t *off);
2291static const struct file_operations adio_fops = {
2292 .owner = THIS_MODULE,
2293 .open = sg_proc_single_open_adio,
2294 .read = seq_read,
2295 .llseek = seq_lseek,
2296 .write = sg_proc_write_adio,
2297 .release = single_release,
2298};
2299
2300static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2301static ssize_t sg_proc_write_dressz(struct file *filp,
2302 const char __user *buffer, size_t count, loff_t *off);
2303static const struct file_operations dressz_fops = {
2304 .owner = THIS_MODULE,
2305 .open = sg_proc_single_open_dressz,
2306 .read = seq_read,
2307 .llseek = seq_lseek,
2308 .write = sg_proc_write_dressz,
2309 .release = single_release,
2310};
2311
2312static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2313static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2314static const struct file_operations version_fops = {
2315 .owner = THIS_MODULE,
2316 .open = sg_proc_single_open_version,
2317 .read = seq_read,
2318 .llseek = seq_lseek,
2319 .release = single_release,
2320};
2321
2322static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2323static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2324static const struct file_operations devhdr_fops = {
2325 .owner = THIS_MODULE,
2326 .open = sg_proc_single_open_devhdr,
2327 .read = seq_read,
2328 .llseek = seq_lseek,
2329 .release = single_release,
2330};
2331
2332static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2333static int sg_proc_open_dev(struct inode *inode, struct file *file);
2334static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2335static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2336static void dev_seq_stop(struct seq_file *s, void *v);
2337static const struct file_operations dev_fops = {
2338 .owner = THIS_MODULE,
2339 .open = sg_proc_open_dev,
2340 .read = seq_read,
2341 .llseek = seq_lseek,
2342 .release = seq_release,
2343};
2344static const struct seq_operations dev_seq_ops = {
2345 .start = dev_seq_start,
2346 .next = dev_seq_next,
2347 .stop = dev_seq_stop,
2348 .show = sg_proc_seq_show_dev,
2349};
2350
2351static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2352static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2353static const struct file_operations devstrs_fops = {
2354 .owner = THIS_MODULE,
2355 .open = sg_proc_open_devstrs,
2356 .read = seq_read,
2357 .llseek = seq_lseek,
2358 .release = seq_release,
2359};
2360static const struct seq_operations devstrs_seq_ops = {
2361 .start = dev_seq_start,
2362 .next = dev_seq_next,
2363 .stop = dev_seq_stop,
2364 .show = sg_proc_seq_show_devstrs,
2365};
2366
2367static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2368static int sg_proc_open_debug(struct inode *inode, struct file *file);
2369static const struct file_operations debug_fops = {
2370 .owner = THIS_MODULE,
2371 .open = sg_proc_open_debug,
2372 .read = seq_read,
2373 .llseek = seq_lseek,
2374 .release = seq_release,
2375};
2376static const struct seq_operations debug_seq_ops = {
2377 .start = dev_seq_start,
2378 .next = dev_seq_next,
2379 .stop = dev_seq_stop,
2380 .show = sg_proc_seq_show_debug,
2381};
2382
2383
2384struct sg_proc_leaf {
2385 const char * name;
2386 const struct file_operations * fops;
2387};
2388
2389static const struct sg_proc_leaf sg_proc_leaf_arr[] = {
2390 {"allow_dio", &adio_fops},
2391 {"debug", &debug_fops},
2392 {"def_reserved_size", &dressz_fops},
2393 {"device_hdr", &devhdr_fops},
2394 {"devices", &dev_fops},
2395 {"device_strs", &devstrs_fops},
2396 {"version", &version_fops}
2397};
2398
2399static int
2400sg_proc_init(void)
2401{
2402 int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2403 int k;
2404
2405 sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2406 if (!sg_proc_sgp)
2407 return 1;
2408 for (k = 0; k < num_leaves; ++k) {
2409 const struct sg_proc_leaf *leaf = &sg_proc_leaf_arr[k];
2410 umode_t mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2411 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2412 }
2413 return 0;
2414}
2415
2416static void
2417sg_proc_cleanup(void)
2418{
2419 int k;
2420 int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2421
2422 if (!sg_proc_sgp)
2423 return;
2424 for (k = 0; k < num_leaves; ++k)
2425 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2426 remove_proc_entry(sg_proc_sg_dirname, NULL);
2427}
2428
2429
2430static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2431{
2432 seq_printf(s, "%d\n", *((int *)s->private));
2433 return 0;
2434}
2435
2436static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2437{
2438 return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2439}
2440
2441static ssize_t
2442sg_proc_write_adio(struct file *filp, const char __user *buffer,
2443 size_t count, loff_t *off)
2444{
2445 int err;
2446 unsigned long num;
2447
2448 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2449 return -EACCES;
2450 err = kstrtoul_from_user(buffer, count, 0, &num);
2451 if (err)
2452 return err;
2453 sg_allow_dio = num ? 1 : 0;
2454 return count;
2455}
2456
2457static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2458{
2459 return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2460}
2461
2462static ssize_t
2463sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2464 size_t count, loff_t *off)
2465{
2466 int err;
2467 unsigned long k = ULONG_MAX;
2468
2469 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2470 return -EACCES;
2471
2472 err = kstrtoul_from_user(buffer, count, 0, &k);
2473 if (err)
2474 return err;
2475 if (k <= 1048576) { /* limit "big buff" to 1 MB */
2476 sg_big_buff = k;
2477 return count;
2478 }
2479 return -ERANGE;
2480}
2481
2482static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2483{
2484 seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2485 sg_version_date);
2486 return 0;
2487}
2488
2489static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2490{
2491 return single_open(file, sg_proc_seq_show_version, NULL);
2492}
2493
2494static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2495{
2496 seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2497 return 0;
2498}
2499
2500static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2501{
2502 return single_open(file, sg_proc_seq_show_devhdr, NULL);
2503}
2504
2505struct sg_proc_deviter {
2506 loff_t index;
2507 size_t max;
2508};
2509
2510static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2511{
2512 struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2513
2514 s->private = it;
2515 if (! it)
2516 return NULL;
2517
2518 it->index = *pos;
2519 it->max = sg_last_dev();
2520 if (it->index >= it->max)
2521 return NULL;
2522 return it;
2523}
2524
2525static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2526{
2527 struct sg_proc_deviter * it = s->private;
2528
2529 *pos = ++it->index;
2530 return (it->index < it->max) ? it : NULL;
2531}
2532
2533static void dev_seq_stop(struct seq_file *s, void *v)
2534{
2535 kfree(s->private);
2536}
2537
2538static int sg_proc_open_dev(struct inode *inode, struct file *file)
2539{
2540 return seq_open(file, &dev_seq_ops);
2541}
2542
2543static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2544{
2545 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2546 Sg_device *sdp;
2547 struct scsi_device *scsidp;
2548 unsigned long iflags;
2549
2550 read_lock_irqsave(&sg_index_lock, iflags);
2551 sdp = it ? sg_lookup_dev(it->index) : NULL;
2552 if ((NULL == sdp) || (NULL == sdp->device) ||
2553 (atomic_read(&sdp->detaching)))
2554 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2555 else {
2556 scsidp = sdp->device;
2557 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2558 scsidp->host->host_no, scsidp->channel,
2559 scsidp->id, scsidp->lun, (int) scsidp->type,
2560 1,
2561 (int) scsidp->queue_depth,
2562 (int) atomic_read(&scsidp->device_busy),
2563 (int) scsi_device_online(scsidp));
2564 }
2565 read_unlock_irqrestore(&sg_index_lock, iflags);
2566 return 0;
2567}
2568
2569static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2570{
2571 return seq_open(file, &devstrs_seq_ops);
2572}
2573
2574static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2575{
2576 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2577 Sg_device *sdp;
2578 struct scsi_device *scsidp;
2579 unsigned long iflags;
2580
2581 read_lock_irqsave(&sg_index_lock, iflags);
2582 sdp = it ? sg_lookup_dev(it->index) : NULL;
2583 scsidp = sdp ? sdp->device : NULL;
2584 if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2585 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2586 scsidp->vendor, scsidp->model, scsidp->rev);
2587 else
2588 seq_puts(s, "<no active device>\n");
2589 read_unlock_irqrestore(&sg_index_lock, iflags);
2590 return 0;
2591}
2592
2593/* must be called while holding sg_index_lock */
2594static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2595{
2596 int k, m, new_interface, blen, usg;
2597 Sg_request *srp;
2598 Sg_fd *fp;
2599 const sg_io_hdr_t *hp;
2600 const char * cp;
2601 unsigned int ms;
2602
2603 k = 0;
2604 list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2605 k++;
2606 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2607 seq_printf(s, " FD(%d): timeout=%dms bufflen=%d "
2608 "(res)sgat=%d low_dma=%d\n", k,
2609 jiffies_to_msecs(fp->timeout),
2610 fp->reserve.bufflen,
2611 (int) fp->reserve.k_use_sg,
2612 (int) fp->low_dma);
2613 seq_printf(s, " cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2614 (int) fp->cmd_q, (int) fp->force_packid,
2615 (int) fp->keep_orphan);
2616 for (m = 0, srp = fp->headrp;
2617 srp != NULL;
2618 ++m, srp = srp->nextrp) {
2619 hp = &srp->header;
2620 new_interface = (hp->interface_id == '\0') ? 0 : 1;
2621 if (srp->res_used) {
2622 if (new_interface &&
2623 (SG_FLAG_MMAP_IO & hp->flags))
2624 cp = " mmap>> ";
2625 else
2626 cp = " rb>> ";
2627 } else {
2628 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2629 cp = " dio>> ";
2630 else
2631 cp = " ";
2632 }
2633 seq_puts(s, cp);
2634 blen = srp->data.bufflen;
2635 usg = srp->data.k_use_sg;
2636 seq_puts(s, srp->done ?
2637 ((1 == srp->done) ? "rcv:" : "fin:")
2638 : "act:");
2639 seq_printf(s, " id=%d blen=%d",
2640 srp->header.pack_id, blen);
2641 if (srp->done)
2642 seq_printf(s, " dur=%d", hp->duration);
2643 else {
2644 ms = jiffies_to_msecs(jiffies);
2645 seq_printf(s, " t_o/elap=%d/%d",
2646 (new_interface ? hp->timeout :
2647 jiffies_to_msecs(fp->timeout)),
2648 (ms > hp->duration ? ms - hp->duration : 0));
2649 }
2650 seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2651 (int) srp->data.cmd_opcode);
2652 }
2653 if (0 == m)
2654 seq_puts(s, " No requests active\n");
2655 read_unlock(&fp->rq_list_lock);
2656 }
2657}
2658
2659static int sg_proc_open_debug(struct inode *inode, struct file *file)
2660{
2661 return seq_open(file, &debug_seq_ops);
2662}
2663
2664static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2665{
2666 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2667 Sg_device *sdp;
2668 unsigned long iflags;
2669
2670 if (it && (0 == it->index))
2671 seq_printf(s, "max_active_device=%d def_reserved_size=%d\n",
2672 (int)it->max, sg_big_buff);
2673
2674 read_lock_irqsave(&sg_index_lock, iflags);
2675 sdp = it ? sg_lookup_dev(it->index) : NULL;
2676 if (NULL == sdp)
2677 goto skip;
2678 read_lock(&sdp->sfd_lock);
2679 if (!list_empty(&sdp->sfds)) {
2680 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2681 if (atomic_read(&sdp->detaching))
2682 seq_puts(s, "detaching pending close ");
2683 else if (sdp->device) {
2684 struct scsi_device *scsidp = sdp->device;
2685
2686 seq_printf(s, "%d:%d:%d:%llu em=%d",
2687 scsidp->host->host_no,
2688 scsidp->channel, scsidp->id,
2689 scsidp->lun,
2690 scsidp->host->hostt->emulated);
2691 }
2692 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2693 sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2694 sg_proc_debug_helper(s, sdp);
2695 }
2696 read_unlock(&sdp->sfd_lock);
2697skip:
2698 read_unlock_irqrestore(&sg_index_lock, iflags);
2699 return 0;
2700}
2701
2702#endif /* CONFIG_SCSI_PROC_FS */
2703
2704module_init(init_sg);
2705module_exit(exit_sg);