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