switch procfs to umode_t use
[linux-2.6.git] / drivers / scsi / sg.c
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 - 2005 Douglas Gilbert
11  *
12  *  Modified  19-JAN-1998  Richard Gooch <rgooch@atnf.csiro.au>  Devfs support
13  *
14  * This program is free software; you can redistribute it and/or modify
15  * it under the terms of the GNU General Public License as published by
16  * the Free Software Foundation; either version 2, or (at your option)
17  * any later version.
18  *
19  */
20
21 static int sg_version_num = 30534;      /* 2 digits for each component */
22 #define SG_VERSION_STR "3.5.34"
23
24 /*
25  *  D. P. Gilbert (dgilbert@interlog.com, dougg@triode.net.au), notes:
26  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
27  *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
28  *        (otherwise the macros compile to empty statements).
29  *
30  */
31 #include <linux/module.h>
32
33 #include <linux/fs.h>
34 #include <linux/kernel.h>
35 #include <linux/sched.h>
36 #include <linux/string.h>
37 #include <linux/mm.h>
38 #include <linux/errno.h>
39 #include <linux/mtio.h>
40 #include <linux/ioctl.h>
41 #include <linux/slab.h>
42 #include <linux/fcntl.h>
43 #include <linux/init.h>
44 #include <linux/poll.h>
45 #include <linux/moduleparam.h>
46 #include <linux/cdev.h>
47 #include <linux/idr.h>
48 #include <linux/seq_file.h>
49 #include <linux/blkdev.h>
50 #include <linux/delay.h>
51 #include <linux/blktrace_api.h>
52 #include <linux/mutex.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 = "20061027";
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 /*
77  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
78  * Then when using 32 bit integers x * m may overflow during the calculation.
79  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
80  * calculates the same, but prevents the overflow when both m and d
81  * are "small" numbers (like HZ and USER_HZ).
82  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
83  * in 32 bits.
84  */
85 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
86
87 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
88
89 int sg_big_buff = SG_DEF_RESERVED_SIZE;
90 /* N.B. This variable is readable and writeable via
91    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
92    of this size (or less if there is not enough memory) will be reserved
93    for use by this file descriptor. [Deprecated usage: this variable is also
94    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
95    the kernel (i.e. it is not a module).] */
96 static int def_reserved_size = -1;      /* picks up init parameter */
97 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
98
99 static int scatter_elem_sz = SG_SCATTER_SZ;
100 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
101
102 #define SG_SECTOR_SZ 512
103
104 static int sg_add(struct device *, struct class_interface *);
105 static void sg_remove(struct device *, struct class_interface *);
106
107 static DEFINE_MUTEX(sg_mutex);
108
109 static DEFINE_IDR(sg_index_idr);
110 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
111                                                            file descriptor list for device */
112
113 static struct class_interface sg_interface = {
114         .add_dev        = sg_add,
115         .remove_dev     = sg_remove,
116 };
117
118 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
119         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
120         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
121         unsigned bufflen;       /* Size of (aggregate) data buffer */
122         struct page **pages;
123         int page_order;
124         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
125         unsigned char cmd_opcode; /* first byte of command */
126 } Sg_scatter_hold;
127
128 struct sg_device;               /* forward declarations */
129 struct sg_fd;
130
131 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
132         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
133         struct sg_fd *parentfp; /* NULL -> not in use */
134         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
135         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
136         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
137         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
138         char orphan;            /* 1 -> drop on sight, 0 -> normal */
139         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
140         volatile char done;     /* 0->before bh, 1->before read, 2->read */
141         struct request *rq;
142         struct bio *bio;
143         struct execute_work ew;
144 } Sg_request;
145
146 typedef struct sg_fd {          /* holds the state of a file descriptor */
147         struct list_head sfd_siblings;
148         struct sg_device *parentdp;     /* owning device */
149         wait_queue_head_t read_wait;    /* queue read until command done */
150         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
151         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
152         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
153         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
154         unsigned save_scat_len; /* original length of trunc. scat. element */
155         Sg_request *headrp;     /* head of request slist, NULL->empty */
156         struct fasync_struct *async_qp; /* used by asynchronous notification */
157         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
158         char low_dma;           /* as in parent but possibly overridden to 1 */
159         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
160         volatile char closed;   /* 1 -> fd closed but request(s) outstanding */
161         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
162         char next_cmd_len;      /* 0 -> automatic (def), >0 -> use on next write() */
163         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
164         char mmap_called;       /* 0 -> mmap() never called on this fd */
165         struct kref f_ref;
166         struct execute_work ew;
167 } Sg_fd;
168
169 typedef struct sg_device { /* holds the state of each scsi generic device */
170         struct scsi_device *device;
171         wait_queue_head_t o_excl_wait;  /* queue open() when O_EXCL in use */
172         int sg_tablesize;       /* adapter's max scatter-gather table size */
173         u32 index;              /* device index number */
174         struct list_head sfds;
175         volatile char detached; /* 0->attached, 1->detached pending removal */
176         volatile char exclude;  /* opened for exclusive access */
177         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
178         struct gendisk *disk;
179         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
180         struct kref d_ref;
181 } Sg_device;
182
183 /* tasklet or soft irq callback */
184 static void sg_rq_end_io(struct request *rq, int uptodate);
185 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
186 static int sg_finish_rem_req(Sg_request * srp);
187 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
188 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
189                            Sg_request * srp);
190 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
191                         const char __user *buf, size_t count, int blocking,
192                         int read_only, int sg_io_owned, Sg_request **o_srp);
193 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
194                            unsigned char *cmnd, int timeout, int blocking);
195 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
196 static void sg_remove_scat(Sg_scatter_hold * schp);
197 static void sg_build_reserve(Sg_fd * sfp, int req_size);
198 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
199 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
200 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
201 static void sg_remove_sfp(struct kref *);
202 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
203 static Sg_request *sg_add_request(Sg_fd * sfp);
204 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
205 static int sg_res_in_use(Sg_fd * sfp);
206 static Sg_device *sg_get_dev(int dev);
207 static void sg_put_dev(Sg_device *sdp);
208
209 #define SZ_SG_HEADER sizeof(struct sg_header)
210 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
211 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
212 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
213
214 static int sg_allow_access(struct file *filp, unsigned char *cmd)
215 {
216         struct sg_fd *sfp = filp->private_data;
217
218         if (sfp->parentdp->device->type == TYPE_SCANNER)
219                 return 0;
220
221         return blk_verify_command(cmd, filp->f_mode & FMODE_WRITE);
222 }
223
224 static int
225 sg_open(struct inode *inode, struct file *filp)
226 {
227         int dev = iminor(inode);
228         int flags = filp->f_flags;
229         struct request_queue *q;
230         Sg_device *sdp;
231         Sg_fd *sfp;
232         int res;
233         int retval;
234
235         mutex_lock(&sg_mutex);
236         nonseekable_open(inode, filp);
237         SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
238         sdp = sg_get_dev(dev);
239         if (IS_ERR(sdp)) {
240                 retval = PTR_ERR(sdp);
241                 sdp = NULL;
242                 goto sg_put;
243         }
244
245         /* This driver's module count bumped by fops_get in <linux/fs.h> */
246         /* Prevent the device driver from vanishing while we sleep */
247         retval = scsi_device_get(sdp->device);
248         if (retval)
249                 goto sg_put;
250
251         retval = scsi_autopm_get_device(sdp->device);
252         if (retval)
253                 goto sdp_put;
254
255         if (!((flags & O_NONBLOCK) ||
256               scsi_block_when_processing_errors(sdp->device))) {
257                 retval = -ENXIO;
258                 /* we are in error recovery for this device */
259                 goto error_out;
260         }
261
262         if (flags & O_EXCL) {
263                 if (O_RDONLY == (flags & O_ACCMODE)) {
264                         retval = -EPERM; /* Can't lock it with read only access */
265                         goto error_out;
266                 }
267                 if (!list_empty(&sdp->sfds) && (flags & O_NONBLOCK)) {
268                         retval = -EBUSY;
269                         goto error_out;
270                 }
271                 res = 0;
272                 __wait_event_interruptible(sdp->o_excl_wait,
273                                            ((!list_empty(&sdp->sfds) || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
274                 if (res) {
275                         retval = res;   /* -ERESTARTSYS because signal hit process */
276                         goto error_out;
277                 }
278         } else if (sdp->exclude) {      /* some other fd has an exclusive lock on dev */
279                 if (flags & O_NONBLOCK) {
280                         retval = -EBUSY;
281                         goto error_out;
282                 }
283                 res = 0;
284                 __wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
285                                            res);
286                 if (res) {
287                         retval = res;   /* -ERESTARTSYS because signal hit process */
288                         goto error_out;
289                 }
290         }
291         if (sdp->detached) {
292                 retval = -ENODEV;
293                 goto error_out;
294         }
295         if (list_empty(&sdp->sfds)) {   /* no existing opens on this device */
296                 sdp->sgdebug = 0;
297                 q = sdp->device->request_queue;
298                 sdp->sg_tablesize = queue_max_segments(q);
299         }
300         if ((sfp = sg_add_sfp(sdp, dev)))
301                 filp->private_data = sfp;
302         else {
303                 if (flags & O_EXCL) {
304                         sdp->exclude = 0;       /* undo if error */
305                         wake_up_interruptible(&sdp->o_excl_wait);
306                 }
307                 retval = -ENOMEM;
308                 goto error_out;
309         }
310         retval = 0;
311 error_out:
312         if (retval) {
313                 scsi_autopm_put_device(sdp->device);
314 sdp_put:
315                 scsi_device_put(sdp->device);
316         }
317 sg_put:
318         if (sdp)
319                 sg_put_dev(sdp);
320         mutex_unlock(&sg_mutex);
321         return retval;
322 }
323
324 /* Following function was formerly called 'sg_close' */
325 static int
326 sg_release(struct inode *inode, struct file *filp)
327 {
328         Sg_device *sdp;
329         Sg_fd *sfp;
330
331         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
332                 return -ENXIO;
333         SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
334
335         sfp->closed = 1;
336
337         sdp->exclude = 0;
338         wake_up_interruptible(&sdp->o_excl_wait);
339
340         scsi_autopm_put_device(sdp->device);
341         kref_put(&sfp->f_ref, sg_remove_sfp);
342         return 0;
343 }
344
345 static ssize_t
346 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
347 {
348         Sg_device *sdp;
349         Sg_fd *sfp;
350         Sg_request *srp;
351         int req_pack_id = -1;
352         sg_io_hdr_t *hp;
353         struct sg_header *old_hdr = NULL;
354         int retval = 0;
355
356         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
357                 return -ENXIO;
358         SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
359                                    sdp->disk->disk_name, (int) count));
360
361         if (!access_ok(VERIFY_WRITE, buf, count))
362                 return -EFAULT;
363         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
364                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
365                 if (!old_hdr)
366                         return -ENOMEM;
367                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
368                         retval = -EFAULT;
369                         goto free_old_hdr;
370                 }
371                 if (old_hdr->reply_len < 0) {
372                         if (count >= SZ_SG_IO_HDR) {
373                                 sg_io_hdr_t *new_hdr;
374                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
375                                 if (!new_hdr) {
376                                         retval = -ENOMEM;
377                                         goto free_old_hdr;
378                                 }
379                                 retval =__copy_from_user
380                                     (new_hdr, buf, SZ_SG_IO_HDR);
381                                 req_pack_id = new_hdr->pack_id;
382                                 kfree(new_hdr);
383                                 if (retval) {
384                                         retval = -EFAULT;
385                                         goto free_old_hdr;
386                                 }
387                         }
388                 } else
389                         req_pack_id = old_hdr->pack_id;
390         }
391         srp = sg_get_rq_mark(sfp, req_pack_id);
392         if (!srp) {             /* now wait on packet to arrive */
393                 if (sdp->detached) {
394                         retval = -ENODEV;
395                         goto free_old_hdr;
396                 }
397                 if (filp->f_flags & O_NONBLOCK) {
398                         retval = -EAGAIN;
399                         goto free_old_hdr;
400                 }
401                 while (1) {
402                         retval = 0; /* following macro beats race condition */
403                         __wait_event_interruptible(sfp->read_wait,
404                                 (sdp->detached ||
405                                 (srp = sg_get_rq_mark(sfp, req_pack_id))), 
406                                 retval);
407                         if (sdp->detached) {
408                                 retval = -ENODEV;
409                                 goto free_old_hdr;
410                         }
411                         if (0 == retval)
412                                 break;
413
414                         /* -ERESTARTSYS as signal hit process */
415                         goto free_old_hdr;
416                 }
417         }
418         if (srp->header.interface_id != '\0') {
419                 retval = sg_new_read(sfp, buf, count, srp);
420                 goto free_old_hdr;
421         }
422
423         hp = &srp->header;
424         if (old_hdr == NULL) {
425                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
426                 if (! old_hdr) {
427                         retval = -ENOMEM;
428                         goto free_old_hdr;
429                 }
430         }
431         memset(old_hdr, 0, SZ_SG_HEADER);
432         old_hdr->reply_len = (int) hp->timeout;
433         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
434         old_hdr->pack_id = hp->pack_id;
435         old_hdr->twelve_byte =
436             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
437         old_hdr->target_status = hp->masked_status;
438         old_hdr->host_status = hp->host_status;
439         old_hdr->driver_status = hp->driver_status;
440         if ((CHECK_CONDITION & hp->masked_status) ||
441             (DRIVER_SENSE & hp->driver_status))
442                 memcpy(old_hdr->sense_buffer, srp->sense_b,
443                        sizeof (old_hdr->sense_buffer));
444         switch (hp->host_status) {
445         /* This setup of 'result' is for backward compatibility and is best
446            ignored by the user who should use target, host + driver status */
447         case DID_OK:
448         case DID_PASSTHROUGH:
449         case DID_SOFT_ERROR:
450                 old_hdr->result = 0;
451                 break;
452         case DID_NO_CONNECT:
453         case DID_BUS_BUSY:
454         case DID_TIME_OUT:
455                 old_hdr->result = EBUSY;
456                 break;
457         case DID_BAD_TARGET:
458         case DID_ABORT:
459         case DID_PARITY:
460         case DID_RESET:
461         case DID_BAD_INTR:
462                 old_hdr->result = EIO;
463                 break;
464         case DID_ERROR:
465                 old_hdr->result = (srp->sense_b[0] == 0 && 
466                                   hp->masked_status == GOOD) ? 0 : EIO;
467                 break;
468         default:
469                 old_hdr->result = EIO;
470                 break;
471         }
472
473         /* Now copy the result back to the user buffer.  */
474         if (count >= SZ_SG_HEADER) {
475                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
476                         retval = -EFAULT;
477                         goto free_old_hdr;
478                 }
479                 buf += SZ_SG_HEADER;
480                 if (count > old_hdr->reply_len)
481                         count = old_hdr->reply_len;
482                 if (count > SZ_SG_HEADER) {
483                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
484                                 retval = -EFAULT;
485                                 goto free_old_hdr;
486                         }
487                 }
488         } else
489                 count = (old_hdr->result == 0) ? 0 : -EIO;
490         sg_finish_rem_req(srp);
491         retval = count;
492 free_old_hdr:
493         kfree(old_hdr);
494         return retval;
495 }
496
497 static ssize_t
498 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
499 {
500         sg_io_hdr_t *hp = &srp->header;
501         int err = 0;
502         int len;
503
504         if (count < SZ_SG_IO_HDR) {
505                 err = -EINVAL;
506                 goto err_out;
507         }
508         hp->sb_len_wr = 0;
509         if ((hp->mx_sb_len > 0) && hp->sbp) {
510                 if ((CHECK_CONDITION & hp->masked_status) ||
511                     (DRIVER_SENSE & hp->driver_status)) {
512                         int sb_len = SCSI_SENSE_BUFFERSIZE;
513                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
514                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
515                         len = (len > sb_len) ? sb_len : len;
516                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
517                                 err = -EFAULT;
518                                 goto err_out;
519                         }
520                         hp->sb_len_wr = len;
521                 }
522         }
523         if (hp->masked_status || hp->host_status || hp->driver_status)
524                 hp->info |= SG_INFO_CHECK;
525         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
526                 err = -EFAULT;
527                 goto err_out;
528         }
529 err_out:
530         err = sg_finish_rem_req(srp);
531         return (0 == err) ? count : err;
532 }
533
534 static ssize_t
535 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
536 {
537         int mxsize, cmd_size, k;
538         int input_size, blocking;
539         unsigned char opcode;
540         Sg_device *sdp;
541         Sg_fd *sfp;
542         Sg_request *srp;
543         struct sg_header old_hdr;
544         sg_io_hdr_t *hp;
545         unsigned char cmnd[MAX_COMMAND_SIZE];
546
547         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
548                 return -ENXIO;
549         SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
550                                    sdp->disk->disk_name, (int) count));
551         if (sdp->detached)
552                 return -ENODEV;
553         if (!((filp->f_flags & O_NONBLOCK) ||
554               scsi_block_when_processing_errors(sdp->device)))
555                 return -ENXIO;
556
557         if (!access_ok(VERIFY_READ, buf, count))
558                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
559         if (count < SZ_SG_HEADER)
560                 return -EIO;
561         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
562                 return -EFAULT;
563         blocking = !(filp->f_flags & O_NONBLOCK);
564         if (old_hdr.reply_len < 0)
565                 return sg_new_write(sfp, filp, buf, count,
566                                     blocking, 0, 0, NULL);
567         if (count < (SZ_SG_HEADER + 6))
568                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
569
570         if (!(srp = sg_add_request(sfp))) {
571                 SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
572                 return -EDOM;
573         }
574         buf += SZ_SG_HEADER;
575         __get_user(opcode, buf);
576         if (sfp->next_cmd_len > 0) {
577                 if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
578                         SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
579                         sfp->next_cmd_len = 0;
580                         sg_remove_request(sfp, srp);
581                         return -EIO;
582                 }
583                 cmd_size = sfp->next_cmd_len;
584                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
585         } else {
586                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
587                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
588                         cmd_size = 12;
589         }
590         SCSI_LOG_TIMEOUT(4, printk(
591                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
592 /* Determine buffer size.  */
593         input_size = count - cmd_size;
594         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
595         mxsize -= SZ_SG_HEADER;
596         input_size -= SZ_SG_HEADER;
597         if (input_size < 0) {
598                 sg_remove_request(sfp, srp);
599                 return -EIO;    /* User did not pass enough bytes for this command. */
600         }
601         hp = &srp->header;
602         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
603         hp->cmd_len = (unsigned char) cmd_size;
604         hp->iovec_count = 0;
605         hp->mx_sb_len = 0;
606         if (input_size > 0)
607                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
608                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
609         else
610                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
611         hp->dxfer_len = mxsize;
612         if (hp->dxfer_direction == SG_DXFER_TO_DEV)
613                 hp->dxferp = (char __user *)buf + cmd_size;
614         else
615                 hp->dxferp = NULL;
616         hp->sbp = NULL;
617         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
618         hp->flags = input_size; /* structure abuse ... */
619         hp->pack_id = old_hdr.pack_id;
620         hp->usr_ptr = NULL;
621         if (__copy_from_user(cmnd, buf, cmd_size))
622                 return -EFAULT;
623         /*
624          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
625          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
626          * is a non-zero input_size, so emit a warning.
627          */
628         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
629                 static char cmd[TASK_COMM_LEN];
630                 if (strcmp(current->comm, cmd)) {
631                         printk_ratelimited(KERN_WARNING
632                                            "sg_write: data in/out %d/%d bytes "
633                                            "for SCSI command 0x%x-- guessing "
634                                            "data in;\n   program %s not setting "
635                                            "count and/or reply_len properly\n",
636                                            old_hdr.reply_len - (int)SZ_SG_HEADER,
637                                            input_size, (unsigned int) cmnd[0],
638                                            current->comm);
639                         strcpy(cmd, current->comm);
640                 }
641         }
642         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
643         return (k < 0) ? k : count;
644 }
645
646 static ssize_t
647 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
648                  size_t count, int blocking, int read_only, int sg_io_owned,
649                  Sg_request **o_srp)
650 {
651         int k;
652         Sg_request *srp;
653         sg_io_hdr_t *hp;
654         unsigned char cmnd[MAX_COMMAND_SIZE];
655         int timeout;
656         unsigned long ul_timeout;
657
658         if (count < SZ_SG_IO_HDR)
659                 return -EINVAL;
660         if (!access_ok(VERIFY_READ, buf, count))
661                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
662
663         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
664         if (!(srp = sg_add_request(sfp))) {
665                 SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
666                 return -EDOM;
667         }
668         srp->sg_io_owned = sg_io_owned;
669         hp = &srp->header;
670         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
671                 sg_remove_request(sfp, srp);
672                 return -EFAULT;
673         }
674         if (hp->interface_id != 'S') {
675                 sg_remove_request(sfp, srp);
676                 return -ENOSYS;
677         }
678         if (hp->flags & SG_FLAG_MMAP_IO) {
679                 if (hp->dxfer_len > sfp->reserve.bufflen) {
680                         sg_remove_request(sfp, srp);
681                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
682                 }
683                 if (hp->flags & SG_FLAG_DIRECT_IO) {
684                         sg_remove_request(sfp, srp);
685                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
686                 }
687                 if (sg_res_in_use(sfp)) {
688                         sg_remove_request(sfp, srp);
689                         return -EBUSY;  /* reserve buffer already being used */
690                 }
691         }
692         ul_timeout = msecs_to_jiffies(srp->header.timeout);
693         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
694         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
695                 sg_remove_request(sfp, srp);
696                 return -EMSGSIZE;
697         }
698         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
699                 sg_remove_request(sfp, srp);
700                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
701         }
702         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
703                 sg_remove_request(sfp, srp);
704                 return -EFAULT;
705         }
706         if (read_only && sg_allow_access(file, cmnd)) {
707                 sg_remove_request(sfp, srp);
708                 return -EPERM;
709         }
710         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
711         if (k < 0)
712                 return k;
713         if (o_srp)
714                 *o_srp = srp;
715         return count;
716 }
717
718 static int
719 sg_common_write(Sg_fd * sfp, Sg_request * srp,
720                 unsigned char *cmnd, int timeout, int blocking)
721 {
722         int k, data_dir;
723         Sg_device *sdp = sfp->parentdp;
724         sg_io_hdr_t *hp = &srp->header;
725
726         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
727         hp->status = 0;
728         hp->masked_status = 0;
729         hp->msg_status = 0;
730         hp->info = 0;
731         hp->host_status = 0;
732         hp->driver_status = 0;
733         hp->resid = 0;
734         SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
735                           (int) cmnd[0], (int) hp->cmd_len));
736
737         k = sg_start_req(srp, cmnd);
738         if (k) {
739                 SCSI_LOG_TIMEOUT(1, printk("sg_common_write: start_req err=%d\n", k));
740                 sg_finish_rem_req(srp);
741                 return k;       /* probably out of space --> ENOMEM */
742         }
743         if (sdp->detached) {
744                 if (srp->bio)
745                         blk_end_request_all(srp->rq, -EIO);
746                 sg_finish_rem_req(srp);
747                 return -ENODEV;
748         }
749
750         switch (hp->dxfer_direction) {
751         case SG_DXFER_TO_FROM_DEV:
752         case SG_DXFER_FROM_DEV:
753                 data_dir = DMA_FROM_DEVICE;
754                 break;
755         case SG_DXFER_TO_DEV:
756                 data_dir = DMA_TO_DEVICE;
757                 break;
758         case SG_DXFER_UNKNOWN:
759                 data_dir = DMA_BIDIRECTIONAL;
760                 break;
761         default:
762                 data_dir = DMA_NONE;
763                 break;
764         }
765         hp->duration = jiffies_to_msecs(jiffies);
766
767         srp->rq->timeout = timeout;
768         kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
769         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
770                               srp->rq, 1, sg_rq_end_io);
771         return 0;
772 }
773
774 static int
775 sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
776 {
777         void __user *p = (void __user *)arg;
778         int __user *ip = p;
779         int result, val, read_only;
780         Sg_device *sdp;
781         Sg_fd *sfp;
782         Sg_request *srp;
783         unsigned long iflags;
784
785         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
786                 return -ENXIO;
787
788         SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
789                                    sdp->disk->disk_name, (int) cmd_in));
790         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
791
792         switch (cmd_in) {
793         case SG_IO:
794                 {
795                         int blocking = 1;       /* ignore O_NONBLOCK flag */
796
797                         if (sdp->detached)
798                                 return -ENODEV;
799                         if (!scsi_block_when_processing_errors(sdp->device))
800                                 return -ENXIO;
801                         if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
802                                 return -EFAULT;
803                         result =
804                             sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
805                                          blocking, read_only, 1, &srp);
806                         if (result < 0)
807                                 return result;
808                         while (1) {
809                                 result = 0;     /* following macro to beat race condition */
810                                 __wait_event_interruptible(sfp->read_wait,
811                                         (srp->done || sdp->detached),
812                                         result);
813                                 if (sdp->detached)
814                                         return -ENODEV;
815                                 write_lock_irq(&sfp->rq_list_lock);
816                                 if (srp->done) {
817                                         srp->done = 2;
818                                         write_unlock_irq(&sfp->rq_list_lock);
819                                         break;
820                                 }
821                                 srp->orphan = 1;
822                                 write_unlock_irq(&sfp->rq_list_lock);
823                                 return result;  /* -ERESTARTSYS because signal hit process */
824                         }
825                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
826                         return (result < 0) ? result : 0;
827                 }
828         case SG_SET_TIMEOUT:
829                 result = get_user(val, ip);
830                 if (result)
831                         return result;
832                 if (val < 0)
833                         return -EIO;
834                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
835                     val = MULDIV (INT_MAX, USER_HZ, HZ);
836                 sfp->timeout_user = val;
837                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
838
839                 return 0;
840         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
841                                 /* strange ..., for backward compatibility */
842                 return sfp->timeout_user;
843         case SG_SET_FORCE_LOW_DMA:
844                 result = get_user(val, ip);
845                 if (result)
846                         return result;
847                 if (val) {
848                         sfp->low_dma = 1;
849                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
850                                 val = (int) sfp->reserve.bufflen;
851                                 sg_remove_scat(&sfp->reserve);
852                                 sg_build_reserve(sfp, val);
853                         }
854                 } else {
855                         if (sdp->detached)
856                                 return -ENODEV;
857                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
858                 }
859                 return 0;
860         case SG_GET_LOW_DMA:
861                 return put_user((int) sfp->low_dma, ip);
862         case SG_GET_SCSI_ID:
863                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
864                         return -EFAULT;
865                 else {
866                         sg_scsi_id_t __user *sg_idp = p;
867
868                         if (sdp->detached)
869                                 return -ENODEV;
870                         __put_user((int) sdp->device->host->host_no,
871                                    &sg_idp->host_no);
872                         __put_user((int) sdp->device->channel,
873                                    &sg_idp->channel);
874                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
875                         __put_user((int) sdp->device->lun, &sg_idp->lun);
876                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
877                         __put_user((short) sdp->device->host->cmd_per_lun,
878                                    &sg_idp->h_cmd_per_lun);
879                         __put_user((short) sdp->device->queue_depth,
880                                    &sg_idp->d_queue_depth);
881                         __put_user(0, &sg_idp->unused[0]);
882                         __put_user(0, &sg_idp->unused[1]);
883                         return 0;
884                 }
885         case SG_SET_FORCE_PACK_ID:
886                 result = get_user(val, ip);
887                 if (result)
888                         return result;
889                 sfp->force_packid = val ? 1 : 0;
890                 return 0;
891         case SG_GET_PACK_ID:
892                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
893                         return -EFAULT;
894                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
895                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
896                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
897                                 read_unlock_irqrestore(&sfp->rq_list_lock,
898                                                        iflags);
899                                 __put_user(srp->header.pack_id, ip);
900                                 return 0;
901                         }
902                 }
903                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
904                 __put_user(-1, ip);
905                 return 0;
906         case SG_GET_NUM_WAITING:
907                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
908                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
909                         if ((1 == srp->done) && (!srp->sg_io_owned))
910                                 ++val;
911                 }
912                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
913                 return put_user(val, ip);
914         case SG_GET_SG_TABLESIZE:
915                 return put_user(sdp->sg_tablesize, ip);
916         case SG_SET_RESERVED_SIZE:
917                 result = get_user(val, ip);
918                 if (result)
919                         return result;
920                 if (val < 0)
921                         return -EINVAL;
922                 val = min_t(int, val,
923                             queue_max_sectors(sdp->device->request_queue) * 512);
924                 if (val != sfp->reserve.bufflen) {
925                         if (sg_res_in_use(sfp) || sfp->mmap_called)
926                                 return -EBUSY;
927                         sg_remove_scat(&sfp->reserve);
928                         sg_build_reserve(sfp, val);
929                 }
930                 return 0;
931         case SG_GET_RESERVED_SIZE:
932                 val = min_t(int, sfp->reserve.bufflen,
933                             queue_max_sectors(sdp->device->request_queue) * 512);
934                 return put_user(val, ip);
935         case SG_SET_COMMAND_Q:
936                 result = get_user(val, ip);
937                 if (result)
938                         return result;
939                 sfp->cmd_q = val ? 1 : 0;
940                 return 0;
941         case SG_GET_COMMAND_Q:
942                 return put_user((int) sfp->cmd_q, ip);
943         case SG_SET_KEEP_ORPHAN:
944                 result = get_user(val, ip);
945                 if (result)
946                         return result;
947                 sfp->keep_orphan = val;
948                 return 0;
949         case SG_GET_KEEP_ORPHAN:
950                 return put_user((int) sfp->keep_orphan, ip);
951         case SG_NEXT_CMD_LEN:
952                 result = get_user(val, ip);
953                 if (result)
954                         return result;
955                 sfp->next_cmd_len = (val > 0) ? val : 0;
956                 return 0;
957         case SG_GET_VERSION_NUM:
958                 return put_user(sg_version_num, ip);
959         case SG_GET_ACCESS_COUNT:
960                 /* faked - we don't have a real access count anymore */
961                 val = (sdp->device ? 1 : 0);
962                 return put_user(val, ip);
963         case SG_GET_REQUEST_TABLE:
964                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
965                         return -EFAULT;
966                 else {
967                         sg_req_info_t *rinfo;
968                         unsigned int ms;
969
970                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
971                                                                 GFP_KERNEL);
972                         if (!rinfo)
973                                 return -ENOMEM;
974                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
975                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
976                              ++val, srp = srp ? srp->nextrp : srp) {
977                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
978                                 if (srp) {
979                                         rinfo[val].req_state = srp->done + 1;
980                                         rinfo[val].problem =
981                                             srp->header.masked_status & 
982                                             srp->header.host_status & 
983                                             srp->header.driver_status;
984                                         if (srp->done)
985                                                 rinfo[val].duration =
986                                                         srp->header.duration;
987                                         else {
988                                                 ms = jiffies_to_msecs(jiffies);
989                                                 rinfo[val].duration =
990                                                     (ms > srp->header.duration) ?
991                                                     (ms - srp->header.duration) : 0;
992                                         }
993                                         rinfo[val].orphan = srp->orphan;
994                                         rinfo[val].sg_io_owned =
995                                                         srp->sg_io_owned;
996                                         rinfo[val].pack_id =
997                                                         srp->header.pack_id;
998                                         rinfo[val].usr_ptr =
999                                                         srp->header.usr_ptr;
1000                                 }
1001                         }
1002                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1003                         result = __copy_to_user(p, rinfo, 
1004                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1005                         result = result ? -EFAULT : 0;
1006                         kfree(rinfo);
1007                         return result;
1008                 }
1009         case SG_EMULATED_HOST:
1010                 if (sdp->detached)
1011                         return -ENODEV;
1012                 return put_user(sdp->device->host->hostt->emulated, ip);
1013         case SG_SCSI_RESET:
1014                 if (sdp->detached)
1015                         return -ENODEV;
1016                 if (filp->f_flags & O_NONBLOCK) {
1017                         if (scsi_host_in_recovery(sdp->device->host))
1018                                 return -EBUSY;
1019                 } else if (!scsi_block_when_processing_errors(sdp->device))
1020                         return -EBUSY;
1021                 result = get_user(val, ip);
1022                 if (result)
1023                         return result;
1024                 if (SG_SCSI_RESET_NOTHING == val)
1025                         return 0;
1026                 switch (val) {
1027                 case SG_SCSI_RESET_DEVICE:
1028                         val = SCSI_TRY_RESET_DEVICE;
1029                         break;
1030                 case SG_SCSI_RESET_TARGET:
1031                         val = SCSI_TRY_RESET_TARGET;
1032                         break;
1033                 case SG_SCSI_RESET_BUS:
1034                         val = SCSI_TRY_RESET_BUS;
1035                         break;
1036                 case SG_SCSI_RESET_HOST:
1037                         val = SCSI_TRY_RESET_HOST;
1038                         break;
1039                 default:
1040                         return -EINVAL;
1041                 }
1042                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1043                         return -EACCES;
1044                 return (scsi_reset_provider(sdp->device, val) ==
1045                         SUCCESS) ? 0 : -EIO;
1046         case SCSI_IOCTL_SEND_COMMAND:
1047                 if (sdp->detached)
1048                         return -ENODEV;
1049                 if (read_only) {
1050                         unsigned char opcode = WRITE_6;
1051                         Scsi_Ioctl_Command __user *siocp = p;
1052
1053                         if (copy_from_user(&opcode, siocp->data, 1))
1054                                 return -EFAULT;
1055                         if (sg_allow_access(filp, &opcode))
1056                                 return -EPERM;
1057                 }
1058                 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1059         case SG_SET_DEBUG:
1060                 result = get_user(val, ip);
1061                 if (result)
1062                         return result;
1063                 sdp->sgdebug = (char) val;
1064                 return 0;
1065         case SCSI_IOCTL_GET_IDLUN:
1066         case SCSI_IOCTL_GET_BUS_NUMBER:
1067         case SCSI_IOCTL_PROBE_HOST:
1068         case SG_GET_TRANSFORM:
1069                 if (sdp->detached)
1070                         return -ENODEV;
1071                 return scsi_ioctl(sdp->device, cmd_in, p);
1072         case BLKSECTGET:
1073                 return put_user(queue_max_sectors(sdp->device->request_queue) * 512,
1074                                 ip);
1075         case BLKTRACESETUP:
1076                 return blk_trace_setup(sdp->device->request_queue,
1077                                        sdp->disk->disk_name,
1078                                        MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1079                                        NULL,
1080                                        (char *)arg);
1081         case BLKTRACESTART:
1082                 return blk_trace_startstop(sdp->device->request_queue, 1);
1083         case BLKTRACESTOP:
1084                 return blk_trace_startstop(sdp->device->request_queue, 0);
1085         case BLKTRACETEARDOWN:
1086                 return blk_trace_remove(sdp->device->request_queue);
1087         default:
1088                 if (read_only)
1089                         return -EPERM;  /* don't know so take safe approach */
1090                 return scsi_ioctl(sdp->device, cmd_in, p);
1091         }
1092 }
1093
1094 static long
1095 sg_unlocked_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1096 {
1097         int ret;
1098
1099         mutex_lock(&sg_mutex);
1100         ret = sg_ioctl(filp, cmd_in, arg);
1101         mutex_unlock(&sg_mutex);
1102
1103         return ret;
1104 }
1105
1106 #ifdef CONFIG_COMPAT
1107 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1108 {
1109         Sg_device *sdp;
1110         Sg_fd *sfp;
1111         struct scsi_device *sdev;
1112
1113         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1114                 return -ENXIO;
1115
1116         sdev = sdp->device;
1117         if (sdev->host->hostt->compat_ioctl) { 
1118                 int ret;
1119
1120                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1121
1122                 return ret;
1123         }
1124         
1125         return -ENOIOCTLCMD;
1126 }
1127 #endif
1128
1129 static unsigned int
1130 sg_poll(struct file *filp, poll_table * wait)
1131 {
1132         unsigned int res = 0;
1133         Sg_device *sdp;
1134         Sg_fd *sfp;
1135         Sg_request *srp;
1136         int count = 0;
1137         unsigned long iflags;
1138
1139         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1140             || sfp->closed)
1141                 return POLLERR;
1142         poll_wait(filp, &sfp->read_wait, wait);
1143         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1144         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1145                 /* if any read waiting, flag it */
1146                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1147                         res = POLLIN | POLLRDNORM;
1148                 ++count;
1149         }
1150         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1151
1152         if (sdp->detached)
1153                 res |= POLLHUP;
1154         else if (!sfp->cmd_q) {
1155                 if (0 == count)
1156                         res |= POLLOUT | POLLWRNORM;
1157         } else if (count < SG_MAX_QUEUE)
1158                 res |= POLLOUT | POLLWRNORM;
1159         SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1160                                    sdp->disk->disk_name, (int) res));
1161         return res;
1162 }
1163
1164 static int
1165 sg_fasync(int fd, struct file *filp, int mode)
1166 {
1167         Sg_device *sdp;
1168         Sg_fd *sfp;
1169
1170         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1171                 return -ENXIO;
1172         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1173                                    sdp->disk->disk_name, mode));
1174
1175         return fasync_helper(fd, filp, mode, &sfp->async_qp);
1176 }
1177
1178 static int
1179 sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1180 {
1181         Sg_fd *sfp;
1182         unsigned long offset, len, sa;
1183         Sg_scatter_hold *rsv_schp;
1184         int k, length;
1185
1186         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1187                 return VM_FAULT_SIGBUS;
1188         rsv_schp = &sfp->reserve;
1189         offset = vmf->pgoff << PAGE_SHIFT;
1190         if (offset >= rsv_schp->bufflen)
1191                 return VM_FAULT_SIGBUS;
1192         SCSI_LOG_TIMEOUT(3, printk("sg_vma_fault: offset=%lu, scatg=%d\n",
1193                                    offset, rsv_schp->k_use_sg));
1194         sa = vma->vm_start;
1195         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1196         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1197                 len = vma->vm_end - sa;
1198                 len = (len < length) ? len : length;
1199                 if (offset < len) {
1200                         struct page *page = nth_page(rsv_schp->pages[k],
1201                                                      offset >> PAGE_SHIFT);
1202                         get_page(page); /* increment page count */
1203                         vmf->page = page;
1204                         return 0; /* success */
1205                 }
1206                 sa += len;
1207                 offset -= len;
1208         }
1209
1210         return VM_FAULT_SIGBUS;
1211 }
1212
1213 static const struct vm_operations_struct sg_mmap_vm_ops = {
1214         .fault = sg_vma_fault,
1215 };
1216
1217 static int
1218 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1219 {
1220         Sg_fd *sfp;
1221         unsigned long req_sz, len, sa;
1222         Sg_scatter_hold *rsv_schp;
1223         int k, length;
1224
1225         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1226                 return -ENXIO;
1227         req_sz = vma->vm_end - vma->vm_start;
1228         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1229                                    (void *) vma->vm_start, (int) req_sz));
1230         if (vma->vm_pgoff)
1231                 return -EINVAL; /* want no offset */
1232         rsv_schp = &sfp->reserve;
1233         if (req_sz > rsv_schp->bufflen)
1234                 return -ENOMEM; /* cannot map more than reserved buffer */
1235
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                 sa += len;
1242         }
1243
1244         sfp->mmap_called = 1;
1245         vma->vm_flags |= VM_RESERVED;
1246         vma->vm_private_data = sfp;
1247         vma->vm_ops = &sg_mmap_vm_ops;
1248         return 0;
1249 }
1250
1251 static void sg_rq_end_io_usercontext(struct work_struct *work)
1252 {
1253         struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1254         struct sg_fd *sfp = srp->parentfp;
1255
1256         sg_finish_rem_req(srp);
1257         kref_put(&sfp->f_ref, sg_remove_sfp);
1258 }
1259
1260 /*
1261  * This function is a "bottom half" handler that is called by the mid
1262  * level when a command is completed (or has failed).
1263  */
1264 static void sg_rq_end_io(struct request *rq, int uptodate)
1265 {
1266         struct sg_request *srp = rq->end_io_data;
1267         Sg_device *sdp;
1268         Sg_fd *sfp;
1269         unsigned long iflags;
1270         unsigned int ms;
1271         char *sense;
1272         int result, resid, done = 1;
1273
1274         if (WARN_ON(srp->done != 0))
1275                 return;
1276
1277         sfp = srp->parentfp;
1278         if (WARN_ON(sfp == NULL))
1279                 return;
1280
1281         sdp = sfp->parentdp;
1282         if (unlikely(sdp->detached))
1283                 printk(KERN_INFO "sg_rq_end_io: device detached\n");
1284
1285         sense = rq->sense;
1286         result = rq->errors;
1287         resid = rq->resid_len;
1288
1289         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1290                 sdp->disk->disk_name, srp->header.pack_id, result));
1291         srp->header.resid = resid;
1292         ms = jiffies_to_msecs(jiffies);
1293         srp->header.duration = (ms > srp->header.duration) ?
1294                                 (ms - srp->header.duration) : 0;
1295         if (0 != result) {
1296                 struct scsi_sense_hdr sshdr;
1297
1298                 srp->header.status = 0xff & result;
1299                 srp->header.masked_status = status_byte(result);
1300                 srp->header.msg_status = msg_byte(result);
1301                 srp->header.host_status = host_byte(result);
1302                 srp->header.driver_status = driver_byte(result);
1303                 if ((sdp->sgdebug > 0) &&
1304                     ((CHECK_CONDITION == srp->header.masked_status) ||
1305                      (COMMAND_TERMINATED == srp->header.masked_status)))
1306                         __scsi_print_sense("sg_cmd_done", sense,
1307                                            SCSI_SENSE_BUFFERSIZE);
1308
1309                 /* Following if statement is a patch supplied by Eric Youngdale */
1310                 if (driver_byte(result) != 0
1311                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1312                     && !scsi_sense_is_deferred(&sshdr)
1313                     && sshdr.sense_key == UNIT_ATTENTION
1314                     && sdp->device->removable) {
1315                         /* Detected possible disc change. Set the bit - this */
1316                         /* may be used if there are filesystems using this device */
1317                         sdp->device->changed = 1;
1318                 }
1319         }
1320         /* Rely on write phase to clean out srp status values, so no "else" */
1321
1322         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1323         if (unlikely(srp->orphan)) {
1324                 if (sfp->keep_orphan)
1325                         srp->sg_io_owned = 0;
1326                 else
1327                         done = 0;
1328         }
1329         srp->done = done;
1330         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1331
1332         if (likely(done)) {
1333                 /* Now wake up any sg_read() that is waiting for this
1334                  * packet.
1335                  */
1336                 wake_up_interruptible(&sfp->read_wait);
1337                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1338                 kref_put(&sfp->f_ref, sg_remove_sfp);
1339         } else {
1340                 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1341                 schedule_work(&srp->ew.work);
1342         }
1343 }
1344
1345 static const struct file_operations sg_fops = {
1346         .owner = THIS_MODULE,
1347         .read = sg_read,
1348         .write = sg_write,
1349         .poll = sg_poll,
1350         .unlocked_ioctl = sg_unlocked_ioctl,
1351 #ifdef CONFIG_COMPAT
1352         .compat_ioctl = sg_compat_ioctl,
1353 #endif
1354         .open = sg_open,
1355         .mmap = sg_mmap,
1356         .release = sg_release,
1357         .fasync = sg_fasync,
1358         .llseek = no_llseek,
1359 };
1360
1361 static struct class *sg_sysfs_class;
1362
1363 static int sg_sysfs_valid = 0;
1364
1365 static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1366 {
1367         struct request_queue *q = scsidp->request_queue;
1368         Sg_device *sdp;
1369         unsigned long iflags;
1370         int error;
1371         u32 k;
1372
1373         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1374         if (!sdp) {
1375                 printk(KERN_WARNING "kmalloc Sg_device failure\n");
1376                 return ERR_PTR(-ENOMEM);
1377         }
1378
1379         if (!idr_pre_get(&sg_index_idr, GFP_KERNEL)) {
1380                 printk(KERN_WARNING "idr expansion Sg_device failure\n");
1381                 error = -ENOMEM;
1382                 goto out;
1383         }
1384
1385         write_lock_irqsave(&sg_index_lock, iflags);
1386
1387         error = idr_get_new(&sg_index_idr, sdp, &k);
1388         if (error) {
1389                 write_unlock_irqrestore(&sg_index_lock, iflags);
1390                 printk(KERN_WARNING "idr allocation Sg_device failure: %d\n",
1391                        error);
1392                 goto out;
1393         }
1394
1395         if (unlikely(k >= SG_MAX_DEVS))
1396                 goto overflow;
1397
1398         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1399         sprintf(disk->disk_name, "sg%d", k);
1400         disk->first_minor = k;
1401         sdp->disk = disk;
1402         sdp->device = scsidp;
1403         INIT_LIST_HEAD(&sdp->sfds);
1404         init_waitqueue_head(&sdp->o_excl_wait);
1405         sdp->sg_tablesize = queue_max_segments(q);
1406         sdp->index = k;
1407         kref_init(&sdp->d_ref);
1408
1409         write_unlock_irqrestore(&sg_index_lock, iflags);
1410
1411         error = 0;
1412  out:
1413         if (error) {
1414                 kfree(sdp);
1415                 return ERR_PTR(error);
1416         }
1417         return sdp;
1418
1419  overflow:
1420         idr_remove(&sg_index_idr, k);
1421         write_unlock_irqrestore(&sg_index_lock, iflags);
1422         sdev_printk(KERN_WARNING, scsidp,
1423                     "Unable to attach sg device type=%d, minor "
1424                     "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1425         error = -ENODEV;
1426         goto out;
1427 }
1428
1429 static int
1430 sg_add(struct device *cl_dev, struct class_interface *cl_intf)
1431 {
1432         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1433         struct gendisk *disk;
1434         Sg_device *sdp = NULL;
1435         struct cdev * cdev = NULL;
1436         int error;
1437         unsigned long iflags;
1438
1439         disk = alloc_disk(1);
1440         if (!disk) {
1441                 printk(KERN_WARNING "alloc_disk failed\n");
1442                 return -ENOMEM;
1443         }
1444         disk->major = SCSI_GENERIC_MAJOR;
1445
1446         error = -ENOMEM;
1447         cdev = cdev_alloc();
1448         if (!cdev) {
1449                 printk(KERN_WARNING "cdev_alloc failed\n");
1450                 goto out;
1451         }
1452         cdev->owner = THIS_MODULE;
1453         cdev->ops = &sg_fops;
1454
1455         sdp = sg_alloc(disk, scsidp);
1456         if (IS_ERR(sdp)) {
1457                 printk(KERN_WARNING "sg_alloc failed\n");
1458                 error = PTR_ERR(sdp);
1459                 goto out;
1460         }
1461
1462         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1463         if (error)
1464                 goto cdev_add_err;
1465
1466         sdp->cdev = cdev;
1467         if (sg_sysfs_valid) {
1468                 struct device *sg_class_member;
1469
1470                 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1471                                                 MKDEV(SCSI_GENERIC_MAJOR,
1472                                                       sdp->index),
1473                                                 sdp, "%s", disk->disk_name);
1474                 if (IS_ERR(sg_class_member)) {
1475                         printk(KERN_ERR "sg_add: "
1476                                "device_create failed\n");
1477                         error = PTR_ERR(sg_class_member);
1478                         goto cdev_add_err;
1479                 }
1480                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1481                                           &sg_class_member->kobj, "generic");
1482                 if (error)
1483                         printk(KERN_ERR "sg_add: unable to make symlink "
1484                                         "'generic' back to sg%d\n", sdp->index);
1485         } else
1486                 printk(KERN_WARNING "sg_add: sg_sys Invalid\n");
1487
1488         sdev_printk(KERN_NOTICE, scsidp,
1489                     "Attached scsi generic sg%d type %d\n", sdp->index,
1490                     scsidp->type);
1491
1492         dev_set_drvdata(cl_dev, sdp);
1493
1494         return 0;
1495
1496 cdev_add_err:
1497         write_lock_irqsave(&sg_index_lock, iflags);
1498         idr_remove(&sg_index_idr, sdp->index);
1499         write_unlock_irqrestore(&sg_index_lock, iflags);
1500         kfree(sdp);
1501
1502 out:
1503         put_disk(disk);
1504         if (cdev)
1505                 cdev_del(cdev);
1506         return error;
1507 }
1508
1509 static void sg_device_destroy(struct kref *kref)
1510 {
1511         struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1512         unsigned long flags;
1513
1514         /* CAUTION!  Note that the device can still be found via idr_find()
1515          * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1516          * any other cleanup.
1517          */
1518
1519         write_lock_irqsave(&sg_index_lock, flags);
1520         idr_remove(&sg_index_idr, sdp->index);
1521         write_unlock_irqrestore(&sg_index_lock, flags);
1522
1523         SCSI_LOG_TIMEOUT(3,
1524                 printk("sg_device_destroy: %s\n",
1525                         sdp->disk->disk_name));
1526
1527         put_disk(sdp->disk);
1528         kfree(sdp);
1529 }
1530
1531 static void sg_remove(struct device *cl_dev, struct class_interface *cl_intf)
1532 {
1533         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1534         Sg_device *sdp = dev_get_drvdata(cl_dev);
1535         unsigned long iflags;
1536         Sg_fd *sfp;
1537
1538         if (!sdp || sdp->detached)
1539                 return;
1540
1541         SCSI_LOG_TIMEOUT(3, printk("sg_remove: %s\n", sdp->disk->disk_name));
1542
1543         /* Need a write lock to set sdp->detached. */
1544         write_lock_irqsave(&sg_index_lock, iflags);
1545         sdp->detached = 1;
1546         list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1547                 wake_up_interruptible(&sfp->read_wait);
1548                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1549         }
1550         write_unlock_irqrestore(&sg_index_lock, iflags);
1551
1552         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1553         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1554         cdev_del(sdp->cdev);
1555         sdp->cdev = NULL;
1556
1557         sg_put_dev(sdp);
1558 }
1559
1560 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1561 module_param_named(def_reserved_size, def_reserved_size, int,
1562                    S_IRUGO | S_IWUSR);
1563 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1564
1565 MODULE_AUTHOR("Douglas Gilbert");
1566 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1567 MODULE_LICENSE("GPL");
1568 MODULE_VERSION(SG_VERSION_STR);
1569 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1570
1571 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1572                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1573 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1574 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1575
1576 static int __init
1577 init_sg(void)
1578 {
1579         int rc;
1580
1581         if (scatter_elem_sz < PAGE_SIZE) {
1582                 scatter_elem_sz = PAGE_SIZE;
1583                 scatter_elem_sz_prev = scatter_elem_sz;
1584         }
1585         if (def_reserved_size >= 0)
1586                 sg_big_buff = def_reserved_size;
1587         else
1588                 def_reserved_size = sg_big_buff;
1589
1590         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), 
1591                                     SG_MAX_DEVS, "sg");
1592         if (rc)
1593                 return rc;
1594         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1595         if ( IS_ERR(sg_sysfs_class) ) {
1596                 rc = PTR_ERR(sg_sysfs_class);
1597                 goto err_out;
1598         }
1599         sg_sysfs_valid = 1;
1600         rc = scsi_register_interface(&sg_interface);
1601         if (0 == rc) {
1602 #ifdef CONFIG_SCSI_PROC_FS
1603                 sg_proc_init();
1604 #endif                          /* CONFIG_SCSI_PROC_FS */
1605                 return 0;
1606         }
1607         class_destroy(sg_sysfs_class);
1608 err_out:
1609         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1610         return rc;
1611 }
1612
1613 static void __exit
1614 exit_sg(void)
1615 {
1616 #ifdef CONFIG_SCSI_PROC_FS
1617         sg_proc_cleanup();
1618 #endif                          /* CONFIG_SCSI_PROC_FS */
1619         scsi_unregister_interface(&sg_interface);
1620         class_destroy(sg_sysfs_class);
1621         sg_sysfs_valid = 0;
1622         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1623                                  SG_MAX_DEVS);
1624         idr_destroy(&sg_index_idr);
1625 }
1626
1627 static int sg_start_req(Sg_request *srp, unsigned char *cmd)
1628 {
1629         int res;
1630         struct request *rq;
1631         Sg_fd *sfp = srp->parentfp;
1632         sg_io_hdr_t *hp = &srp->header;
1633         int dxfer_len = (int) hp->dxfer_len;
1634         int dxfer_dir = hp->dxfer_direction;
1635         unsigned int iov_count = hp->iovec_count;
1636         Sg_scatter_hold *req_schp = &srp->data;
1637         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1638         struct request_queue *q = sfp->parentdp->device->request_queue;
1639         struct rq_map_data *md, map_data;
1640         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1641
1642         SCSI_LOG_TIMEOUT(4, printk(KERN_INFO "sg_start_req: dxfer_len=%d\n",
1643                                    dxfer_len));
1644
1645         rq = blk_get_request(q, rw, GFP_ATOMIC);
1646         if (!rq)
1647                 return -ENOMEM;
1648
1649         memcpy(rq->cmd, cmd, hp->cmd_len);
1650
1651         rq->cmd_len = hp->cmd_len;
1652         rq->cmd_type = REQ_TYPE_BLOCK_PC;
1653
1654         srp->rq = rq;
1655         rq->end_io_data = srp;
1656         rq->sense = srp->sense_b;
1657         rq->retries = SG_DEFAULT_RETRIES;
1658
1659         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1660                 return 0;
1661
1662         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1663             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1664             !sfp->parentdp->device->host->unchecked_isa_dma &&
1665             blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1666                 md = NULL;
1667         else
1668                 md = &map_data;
1669
1670         if (md) {
1671                 if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen)
1672                         sg_link_reserve(sfp, srp, dxfer_len);
1673                 else {
1674                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1675                         if (res)
1676                                 return res;
1677                 }
1678
1679                 md->pages = req_schp->pages;
1680                 md->page_order = req_schp->page_order;
1681                 md->nr_entries = req_schp->k_use_sg;
1682                 md->offset = 0;
1683                 md->null_mapped = hp->dxferp ? 0 : 1;
1684                 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1685                         md->from_user = 1;
1686                 else
1687                         md->from_user = 0;
1688         }
1689
1690         if (iov_count) {
1691                 int len, size = sizeof(struct sg_iovec) * iov_count;
1692                 struct iovec *iov;
1693
1694                 iov = memdup_user(hp->dxferp, size);
1695                 if (IS_ERR(iov))
1696                         return PTR_ERR(iov);
1697
1698                 len = iov_length(iov, iov_count);
1699                 if (hp->dxfer_len < len) {
1700                         iov_count = iov_shorten(iov, iov_count, hp->dxfer_len);
1701                         len = hp->dxfer_len;
1702                 }
1703
1704                 res = blk_rq_map_user_iov(q, rq, md, (struct sg_iovec *)iov,
1705                                           iov_count,
1706                                           len, GFP_ATOMIC);
1707                 kfree(iov);
1708         } else
1709                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1710                                       hp->dxfer_len, GFP_ATOMIC);
1711
1712         if (!res) {
1713                 srp->bio = rq->bio;
1714
1715                 if (!md) {
1716                         req_schp->dio_in_use = 1;
1717                         hp->info |= SG_INFO_DIRECT_IO;
1718                 }
1719         }
1720         return res;
1721 }
1722
1723 static int sg_finish_rem_req(Sg_request * srp)
1724 {
1725         int ret = 0;
1726
1727         Sg_fd *sfp = srp->parentfp;
1728         Sg_scatter_hold *req_schp = &srp->data;
1729
1730         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1731         if (srp->rq) {
1732                 if (srp->bio)
1733                         ret = blk_rq_unmap_user(srp->bio);
1734
1735                 blk_put_request(srp->rq);
1736         }
1737
1738         if (srp->res_used)
1739                 sg_unlink_reserve(sfp, srp);
1740         else
1741                 sg_remove_scat(req_schp);
1742
1743         sg_remove_request(sfp, srp);
1744
1745         return ret;
1746 }
1747
1748 static int
1749 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1750 {
1751         int sg_bufflen = tablesize * sizeof(struct page *);
1752         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1753
1754         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1755         if (!schp->pages)
1756                 return -ENOMEM;
1757         schp->sglist_len = sg_bufflen;
1758         return tablesize;       /* number of scat_gath elements allocated */
1759 }
1760
1761 static int
1762 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1763 {
1764         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1765         int sg_tablesize = sfp->parentdp->sg_tablesize;
1766         int blk_size = buff_size, order;
1767         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1768
1769         if (blk_size < 0)
1770                 return -EFAULT;
1771         if (0 == blk_size)
1772                 ++blk_size;     /* don't know why */
1773         /* round request up to next highest SG_SECTOR_SZ byte boundary */
1774         blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1775         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1776                                    buff_size, blk_size));
1777
1778         /* N.B. ret_sz carried into this block ... */
1779         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1780         if (mx_sc_elems < 0)
1781                 return mx_sc_elems;     /* most likely -ENOMEM */
1782
1783         num = scatter_elem_sz;
1784         if (unlikely(num != scatter_elem_sz_prev)) {
1785                 if (num < PAGE_SIZE) {
1786                         scatter_elem_sz = PAGE_SIZE;
1787                         scatter_elem_sz_prev = PAGE_SIZE;
1788                 } else
1789                         scatter_elem_sz_prev = num;
1790         }
1791
1792         if (sfp->low_dma)
1793                 gfp_mask |= GFP_DMA;
1794
1795         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1796                 gfp_mask |= __GFP_ZERO;
1797
1798         order = get_order(num);
1799 retry:
1800         ret_sz = 1 << (PAGE_SHIFT + order);
1801
1802         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1803              k++, rem_sz -= ret_sz) {
1804
1805                 num = (rem_sz > scatter_elem_sz_prev) ?
1806                         scatter_elem_sz_prev : rem_sz;
1807
1808                 schp->pages[k] = alloc_pages(gfp_mask, order);
1809                 if (!schp->pages[k])
1810                         goto out;
1811
1812                 if (num == scatter_elem_sz_prev) {
1813                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1814                                 scatter_elem_sz = ret_sz;
1815                                 scatter_elem_sz_prev = ret_sz;
1816                         }
1817                 }
1818
1819                 SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k=%d, num=%d, "
1820                                  "ret_sz=%d\n", k, num, ret_sz));
1821         }               /* end of for loop */
1822
1823         schp->page_order = order;
1824         schp->k_use_sg = k;
1825         SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, "
1826                          "rem_sz=%d\n", k, rem_sz));
1827
1828         schp->bufflen = blk_size;
1829         if (rem_sz > 0) /* must have failed */
1830                 return -ENOMEM;
1831         return 0;
1832 out:
1833         for (i = 0; i < k; i++)
1834                 __free_pages(schp->pages[i], order);
1835
1836         if (--order >= 0)
1837                 goto retry;
1838
1839         return -ENOMEM;
1840 }
1841
1842 static void
1843 sg_remove_scat(Sg_scatter_hold * schp)
1844 {
1845         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1846         if (schp->pages && schp->sglist_len > 0) {
1847                 if (!schp->dio_in_use) {
1848                         int k;
1849
1850                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1851                                 SCSI_LOG_TIMEOUT(5, printk(
1852                                     "sg_remove_scat: k=%d, pg=0x%p\n",
1853                                     k, schp->pages[k]));
1854                                 __free_pages(schp->pages[k], schp->page_order);
1855                         }
1856
1857                         kfree(schp->pages);
1858                 }
1859         }
1860         memset(schp, 0, sizeof (*schp));
1861 }
1862
1863 static int
1864 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1865 {
1866         Sg_scatter_hold *schp = &srp->data;
1867         int k, num;
1868
1869         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
1870                                    num_read_xfer));
1871         if ((!outp) || (num_read_xfer <= 0))
1872                 return 0;
1873
1874         num = 1 << (PAGE_SHIFT + schp->page_order);
1875         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1876                 if (num > num_read_xfer) {
1877                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1878                                            num_read_xfer))
1879                                 return -EFAULT;
1880                         break;
1881                 } else {
1882                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1883                                            num))
1884                                 return -EFAULT;
1885                         num_read_xfer -= num;
1886                         if (num_read_xfer <= 0)
1887                                 break;
1888                         outp += num;
1889                 }
1890         }
1891
1892         return 0;
1893 }
1894
1895 static void
1896 sg_build_reserve(Sg_fd * sfp, int req_size)
1897 {
1898         Sg_scatter_hold *schp = &sfp->reserve;
1899
1900         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
1901         do {
1902                 if (req_size < PAGE_SIZE)
1903                         req_size = PAGE_SIZE;
1904                 if (0 == sg_build_indirect(schp, sfp, req_size))
1905                         return;
1906                 else
1907                         sg_remove_scat(schp);
1908                 req_size >>= 1; /* divide by 2 */
1909         } while (req_size > (PAGE_SIZE / 2));
1910 }
1911
1912 static void
1913 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1914 {
1915         Sg_scatter_hold *req_schp = &srp->data;
1916         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1917         int k, num, rem;
1918
1919         srp->res_used = 1;
1920         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
1921         rem = size;
1922
1923         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1924         for (k = 0; k < rsv_schp->k_use_sg; k++) {
1925                 if (rem <= num) {
1926                         req_schp->k_use_sg = k + 1;
1927                         req_schp->sglist_len = rsv_schp->sglist_len;
1928                         req_schp->pages = rsv_schp->pages;
1929
1930                         req_schp->bufflen = size;
1931                         req_schp->page_order = rsv_schp->page_order;
1932                         break;
1933                 } else
1934                         rem -= num;
1935         }
1936
1937         if (k >= rsv_schp->k_use_sg)
1938                 SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
1939 }
1940
1941 static void
1942 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
1943 {
1944         Sg_scatter_hold *req_schp = &srp->data;
1945
1946         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
1947                                    (int) req_schp->k_use_sg));
1948         req_schp->k_use_sg = 0;
1949         req_schp->bufflen = 0;
1950         req_schp->pages = NULL;
1951         req_schp->page_order = 0;
1952         req_schp->sglist_len = 0;
1953         sfp->save_scat_len = 0;
1954         srp->res_used = 0;
1955 }
1956
1957 static Sg_request *
1958 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
1959 {
1960         Sg_request *resp;
1961         unsigned long iflags;
1962
1963         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1964         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
1965                 /* look for requests that are ready + not SG_IO owned */
1966                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
1967                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
1968                         resp->done = 2; /* guard against other readers */
1969                         break;
1970                 }
1971         }
1972         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1973         return resp;
1974 }
1975
1976 /* always adds to end of list */
1977 static Sg_request *
1978 sg_add_request(Sg_fd * sfp)
1979 {
1980         int k;
1981         unsigned long iflags;
1982         Sg_request *resp;
1983         Sg_request *rp = sfp->req_arr;
1984
1985         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1986         resp = sfp->headrp;
1987         if (!resp) {
1988                 memset(rp, 0, sizeof (Sg_request));
1989                 rp->parentfp = sfp;
1990                 resp = rp;
1991                 sfp->headrp = resp;
1992         } else {
1993                 if (0 == sfp->cmd_q)
1994                         resp = NULL;    /* command queuing disallowed */
1995                 else {
1996                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
1997                                 if (!rp->parentfp)
1998                                         break;
1999                         }
2000                         if (k < SG_MAX_QUEUE) {
2001                                 memset(rp, 0, sizeof (Sg_request));
2002                                 rp->parentfp = sfp;
2003                                 while (resp->nextrp)
2004                                         resp = resp->nextrp;
2005                                 resp->nextrp = rp;
2006                                 resp = rp;
2007                         } else
2008                                 resp = NULL;
2009                 }
2010         }
2011         if (resp) {
2012                 resp->nextrp = NULL;
2013                 resp->header.duration = jiffies_to_msecs(jiffies);
2014         }
2015         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2016         return resp;
2017 }
2018
2019 /* Return of 1 for found; 0 for not found */
2020 static int
2021 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2022 {
2023         Sg_request *prev_rp;
2024         Sg_request *rp;
2025         unsigned long iflags;
2026         int res = 0;
2027
2028         if ((!sfp) || (!srp) || (!sfp->headrp))
2029                 return res;
2030         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2031         prev_rp = sfp->headrp;
2032         if (srp == prev_rp) {
2033                 sfp->headrp = prev_rp->nextrp;
2034                 prev_rp->parentfp = NULL;
2035                 res = 1;
2036         } else {
2037                 while ((rp = prev_rp->nextrp)) {
2038                         if (srp == rp) {
2039                                 prev_rp->nextrp = rp->nextrp;
2040                                 rp->parentfp = NULL;
2041                                 res = 1;
2042                                 break;
2043                         }
2044                         prev_rp = rp;
2045                 }
2046         }
2047         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2048         return res;
2049 }
2050
2051 static Sg_fd *
2052 sg_add_sfp(Sg_device * sdp, int dev)
2053 {
2054         Sg_fd *sfp;
2055         unsigned long iflags;
2056         int bufflen;
2057
2058         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2059         if (!sfp)
2060                 return NULL;
2061
2062         init_waitqueue_head(&sfp->read_wait);
2063         rwlock_init(&sfp->rq_list_lock);
2064
2065         kref_init(&sfp->f_ref);
2066         sfp->timeout = SG_DEFAULT_TIMEOUT;
2067         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2068         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2069         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2070             sdp->device->host->unchecked_isa_dma : 1;
2071         sfp->cmd_q = SG_DEF_COMMAND_Q;
2072         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2073         sfp->parentdp = sdp;
2074         write_lock_irqsave(&sg_index_lock, iflags);
2075         list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2076         write_unlock_irqrestore(&sg_index_lock, iflags);
2077         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2078         if (unlikely(sg_big_buff != def_reserved_size))
2079                 sg_big_buff = def_reserved_size;
2080
2081         bufflen = min_t(int, sg_big_buff,
2082                         queue_max_sectors(sdp->device->request_queue) * 512);
2083         sg_build_reserve(sfp, bufflen);
2084         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2085                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2086
2087         kref_get(&sdp->d_ref);
2088         __module_get(THIS_MODULE);
2089         return sfp;
2090 }
2091
2092 static void sg_remove_sfp_usercontext(struct work_struct *work)
2093 {
2094         struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2095         struct sg_device *sdp = sfp->parentdp;
2096
2097         /* Cleanup any responses which were never read(). */
2098         while (sfp->headrp)
2099                 sg_finish_rem_req(sfp->headrp);
2100
2101         if (sfp->reserve.bufflen > 0) {
2102                 SCSI_LOG_TIMEOUT(6,
2103                         printk("sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2104                                 (int) sfp->reserve.bufflen,
2105                                 (int) sfp->reserve.k_use_sg));
2106                 sg_remove_scat(&sfp->reserve);
2107         }
2108
2109         SCSI_LOG_TIMEOUT(6,
2110                 printk("sg_remove_sfp: %s, sfp=0x%p\n",
2111                         sdp->disk->disk_name,
2112                         sfp));
2113         kfree(sfp);
2114
2115         scsi_device_put(sdp->device);
2116         sg_put_dev(sdp);
2117         module_put(THIS_MODULE);
2118 }
2119
2120 static void sg_remove_sfp(struct kref *kref)
2121 {
2122         struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2123         struct sg_device *sdp = sfp->parentdp;
2124         unsigned long iflags;
2125
2126         write_lock_irqsave(&sg_index_lock, iflags);
2127         list_del(&sfp->sfd_siblings);
2128         write_unlock_irqrestore(&sg_index_lock, iflags);
2129         wake_up_interruptible(&sdp->o_excl_wait);
2130
2131         INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2132         schedule_work(&sfp->ew.work);
2133 }
2134
2135 static int
2136 sg_res_in_use(Sg_fd * sfp)
2137 {
2138         const Sg_request *srp;
2139         unsigned long iflags;
2140
2141         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2142         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2143                 if (srp->res_used)
2144                         break;
2145         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2146         return srp ? 1 : 0;
2147 }
2148
2149 #ifdef CONFIG_SCSI_PROC_FS
2150 static int
2151 sg_idr_max_id(int id, void *p, void *data)
2152 {
2153         int *k = data;
2154
2155         if (*k < id)
2156                 *k = id;
2157
2158         return 0;
2159 }
2160
2161 static int
2162 sg_last_dev(void)
2163 {
2164         int k = -1;
2165         unsigned long iflags;
2166
2167         read_lock_irqsave(&sg_index_lock, iflags);
2168         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2169         read_unlock_irqrestore(&sg_index_lock, iflags);
2170         return k + 1;           /* origin 1 */
2171 }
2172 #endif
2173
2174 /* must be called with sg_index_lock held */
2175 static Sg_device *sg_lookup_dev(int dev)
2176 {
2177         return idr_find(&sg_index_idr, dev);
2178 }
2179
2180 static Sg_device *sg_get_dev(int dev)
2181 {
2182         struct sg_device *sdp;
2183         unsigned long flags;
2184
2185         read_lock_irqsave(&sg_index_lock, flags);
2186         sdp = sg_lookup_dev(dev);
2187         if (!sdp)
2188                 sdp = ERR_PTR(-ENXIO);
2189         else if (sdp->detached) {
2190                 /* If sdp->detached, then the refcount may already be 0, in
2191                  * which case it would be a bug to do kref_get().
2192                  */
2193                 sdp = ERR_PTR(-ENODEV);
2194         } else
2195                 kref_get(&sdp->d_ref);
2196         read_unlock_irqrestore(&sg_index_lock, flags);
2197
2198         return sdp;
2199 }
2200
2201 static void sg_put_dev(struct sg_device *sdp)
2202 {
2203         kref_put(&sdp->d_ref, sg_device_destroy);
2204 }
2205
2206 #ifdef CONFIG_SCSI_PROC_FS
2207
2208 static struct proc_dir_entry *sg_proc_sgp = NULL;
2209
2210 static char sg_proc_sg_dirname[] = "scsi/sg";
2211
2212 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2213
2214 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2215 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2216                                   size_t count, loff_t *off);
2217 static const struct file_operations adio_fops = {
2218         .owner = THIS_MODULE,
2219         .open = sg_proc_single_open_adio,
2220         .read = seq_read,
2221         .llseek = seq_lseek,
2222         .write = sg_proc_write_adio,
2223         .release = single_release,
2224 };
2225
2226 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2227 static ssize_t sg_proc_write_dressz(struct file *filp, 
2228                 const char __user *buffer, size_t count, loff_t *off);
2229 static const struct file_operations dressz_fops = {
2230         .owner = THIS_MODULE,
2231         .open = sg_proc_single_open_dressz,
2232         .read = seq_read,
2233         .llseek = seq_lseek,
2234         .write = sg_proc_write_dressz,
2235         .release = single_release,
2236 };
2237
2238 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2239 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2240 static const struct file_operations version_fops = {
2241         .owner = THIS_MODULE,
2242         .open = sg_proc_single_open_version,
2243         .read = seq_read,
2244         .llseek = seq_lseek,
2245         .release = single_release,
2246 };
2247
2248 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2249 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2250 static const struct file_operations devhdr_fops = {
2251         .owner = THIS_MODULE,
2252         .open = sg_proc_single_open_devhdr,
2253         .read = seq_read,
2254         .llseek = seq_lseek,
2255         .release = single_release,
2256 };
2257
2258 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2259 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2260 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2261 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2262 static void dev_seq_stop(struct seq_file *s, void *v);
2263 static const struct file_operations dev_fops = {
2264         .owner = THIS_MODULE,
2265         .open = sg_proc_open_dev,
2266         .read = seq_read,
2267         .llseek = seq_lseek,
2268         .release = seq_release,
2269 };
2270 static const struct seq_operations dev_seq_ops = {
2271         .start = dev_seq_start,
2272         .next  = dev_seq_next,
2273         .stop  = dev_seq_stop,
2274         .show  = sg_proc_seq_show_dev,
2275 };
2276
2277 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2278 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2279 static const struct file_operations devstrs_fops = {
2280         .owner = THIS_MODULE,
2281         .open = sg_proc_open_devstrs,
2282         .read = seq_read,
2283         .llseek = seq_lseek,
2284         .release = seq_release,
2285 };
2286 static const struct seq_operations devstrs_seq_ops = {
2287         .start = dev_seq_start,
2288         .next  = dev_seq_next,
2289         .stop  = dev_seq_stop,
2290         .show  = sg_proc_seq_show_devstrs,
2291 };
2292
2293 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2294 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2295 static const struct file_operations debug_fops = {
2296         .owner = THIS_MODULE,
2297         .open = sg_proc_open_debug,
2298         .read = seq_read,
2299         .llseek = seq_lseek,
2300         .release = seq_release,
2301 };
2302 static const struct seq_operations debug_seq_ops = {
2303         .start = dev_seq_start,
2304         .next  = dev_seq_next,
2305         .stop  = dev_seq_stop,
2306         .show  = sg_proc_seq_show_debug,
2307 };
2308
2309
2310 struct sg_proc_leaf {
2311         const char * name;
2312         const struct file_operations * fops;
2313 };
2314
2315 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2316         {"allow_dio", &adio_fops},
2317         {"debug", &debug_fops},
2318         {"def_reserved_size", &dressz_fops},
2319         {"device_hdr", &devhdr_fops},
2320         {"devices", &dev_fops},
2321         {"device_strs", &devstrs_fops},
2322         {"version", &version_fops}
2323 };
2324
2325 static int
2326 sg_proc_init(void)
2327 {
2328         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2329         int k;
2330
2331         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2332         if (!sg_proc_sgp)
2333                 return 1;
2334         for (k = 0; k < num_leaves; ++k) {
2335                 struct sg_proc_leaf *leaf = &sg_proc_leaf_arr[k];
2336                 umode_t mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2337                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2338         }
2339         return 0;
2340 }
2341
2342 static void
2343 sg_proc_cleanup(void)
2344 {
2345         int k;
2346         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2347
2348         if (!sg_proc_sgp)
2349                 return;
2350         for (k = 0; k < num_leaves; ++k)
2351                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2352         remove_proc_entry(sg_proc_sg_dirname, NULL);
2353 }
2354
2355
2356 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2357 {
2358         seq_printf(s, "%d\n", *((int *)s->private));
2359         return 0;
2360 }
2361
2362 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2363 {
2364         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2365 }
2366
2367 static ssize_t 
2368 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2369                    size_t count, loff_t *off)
2370 {
2371         int num;
2372         char buff[11];
2373
2374         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2375                 return -EACCES;
2376         num = (count < 10) ? count : 10;
2377         if (copy_from_user(buff, buffer, num))
2378                 return -EFAULT;
2379         buff[num] = '\0';
2380         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2381         return count;
2382 }
2383
2384 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2385 {
2386         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2387 }
2388
2389 static ssize_t 
2390 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2391                      size_t count, loff_t *off)
2392 {
2393         int num;
2394         unsigned long k = ULONG_MAX;
2395         char buff[11];
2396
2397         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2398                 return -EACCES;
2399         num = (count < 10) ? count : 10;
2400         if (copy_from_user(buff, buffer, num))
2401                 return -EFAULT;
2402         buff[num] = '\0';
2403         k = simple_strtoul(buff, NULL, 10);
2404         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2405                 sg_big_buff = k;
2406                 return count;
2407         }
2408         return -ERANGE;
2409 }
2410
2411 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2412 {
2413         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2414                    sg_version_date);
2415         return 0;
2416 }
2417
2418 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2419 {
2420         return single_open(file, sg_proc_seq_show_version, NULL);
2421 }
2422
2423 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2424 {
2425         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2426                    "online\n");
2427         return 0;
2428 }
2429
2430 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2431 {
2432         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2433 }
2434
2435 struct sg_proc_deviter {
2436         loff_t  index;
2437         size_t  max;
2438 };
2439
2440 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2441 {
2442         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2443
2444         s->private = it;
2445         if (! it)
2446                 return NULL;
2447
2448         it->index = *pos;
2449         it->max = sg_last_dev();
2450         if (it->index >= it->max)
2451                 return NULL;
2452         return it;
2453 }
2454
2455 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2456 {
2457         struct sg_proc_deviter * it = s->private;
2458
2459         *pos = ++it->index;
2460         return (it->index < it->max) ? it : NULL;
2461 }
2462
2463 static void dev_seq_stop(struct seq_file *s, void *v)
2464 {
2465         kfree(s->private);
2466 }
2467
2468 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2469 {
2470         return seq_open(file, &dev_seq_ops);
2471 }
2472
2473 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2474 {
2475         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2476         Sg_device *sdp;
2477         struct scsi_device *scsidp;
2478         unsigned long iflags;
2479
2480         read_lock_irqsave(&sg_index_lock, iflags);
2481         sdp = it ? sg_lookup_dev(it->index) : NULL;
2482         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2483                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2484                               scsidp->host->host_no, scsidp->channel,
2485                               scsidp->id, scsidp->lun, (int) scsidp->type,
2486                               1,
2487                               (int) scsidp->queue_depth,
2488                               (int) scsidp->device_busy,
2489                               (int) scsi_device_online(scsidp));
2490         else
2491                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2492         read_unlock_irqrestore(&sg_index_lock, iflags);
2493         return 0;
2494 }
2495
2496 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2497 {
2498         return seq_open(file, &devstrs_seq_ops);
2499 }
2500
2501 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2502 {
2503         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2504         Sg_device *sdp;
2505         struct scsi_device *scsidp;
2506         unsigned long iflags;
2507
2508         read_lock_irqsave(&sg_index_lock, iflags);
2509         sdp = it ? sg_lookup_dev(it->index) : NULL;
2510         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2511                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2512                            scsidp->vendor, scsidp->model, scsidp->rev);
2513         else
2514                 seq_printf(s, "<no active device>\n");
2515         read_unlock_irqrestore(&sg_index_lock, iflags);
2516         return 0;
2517 }
2518
2519 /* must be called while holding sg_index_lock */
2520 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2521 {
2522         int k, m, new_interface, blen, usg;
2523         Sg_request *srp;
2524         Sg_fd *fp;
2525         const sg_io_hdr_t *hp;
2526         const char * cp;
2527         unsigned int ms;
2528
2529         k = 0;
2530         list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2531                 k++;
2532                 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2533                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2534                            "(res)sgat=%d low_dma=%d\n", k,
2535                            jiffies_to_msecs(fp->timeout),
2536                            fp->reserve.bufflen,
2537                            (int) fp->reserve.k_use_sg,
2538                            (int) fp->low_dma);
2539                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2540                            (int) fp->cmd_q, (int) fp->force_packid,
2541                            (int) fp->keep_orphan, (int) fp->closed);
2542                 for (m = 0, srp = fp->headrp;
2543                                 srp != NULL;
2544                                 ++m, srp = srp->nextrp) {
2545                         hp = &srp->header;
2546                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2547                         if (srp->res_used) {
2548                                 if (new_interface && 
2549                                     (SG_FLAG_MMAP_IO & hp->flags))
2550                                         cp = "     mmap>> ";
2551                                 else
2552                                         cp = "     rb>> ";
2553                         } else {
2554                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2555                                         cp = "     dio>> ";
2556                                 else
2557                                         cp = "     ";
2558                         }
2559                         seq_printf(s, cp);
2560                         blen = srp->data.bufflen;
2561                         usg = srp->data.k_use_sg;
2562                         seq_printf(s, srp->done ? 
2563                                    ((1 == srp->done) ?  "rcv:" : "fin:")
2564                                    : "act:");
2565                         seq_printf(s, " id=%d blen=%d",
2566                                    srp->header.pack_id, blen);
2567                         if (srp->done)
2568                                 seq_printf(s, " dur=%d", hp->duration);
2569                         else {
2570                                 ms = jiffies_to_msecs(jiffies);
2571                                 seq_printf(s, " t_o/elap=%d/%d",
2572                                         (new_interface ? hp->timeout :
2573                                                   jiffies_to_msecs(fp->timeout)),
2574                                         (ms > hp->duration ? ms - hp->duration : 0));
2575                         }
2576                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2577                                    (int) srp->data.cmd_opcode);
2578                 }
2579                 if (0 == m)
2580                         seq_printf(s, "     No requests active\n");
2581                 read_unlock(&fp->rq_list_lock);
2582         }
2583 }
2584
2585 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2586 {
2587         return seq_open(file, &debug_seq_ops);
2588 }
2589
2590 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2591 {
2592         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2593         Sg_device *sdp;
2594         unsigned long iflags;
2595
2596         if (it && (0 == it->index)) {
2597                 seq_printf(s, "max_active_device=%d(origin 1)\n",
2598                            (int)it->max);
2599                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2600         }
2601
2602         read_lock_irqsave(&sg_index_lock, iflags);
2603         sdp = it ? sg_lookup_dev(it->index) : NULL;
2604         if (sdp && !list_empty(&sdp->sfds)) {
2605                 struct scsi_device *scsidp = sdp->device;
2606
2607                 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2608                 if (sdp->detached)
2609                         seq_printf(s, "detached pending close ");
2610                 else
2611                         seq_printf
2612                             (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2613                              scsidp->host->host_no,
2614                              scsidp->channel, scsidp->id,
2615                              scsidp->lun,
2616                              scsidp->host->hostt->emulated);
2617                 seq_printf(s, " sg_tablesize=%d excl=%d\n",
2618                            sdp->sg_tablesize, sdp->exclude);
2619                 sg_proc_debug_helper(s, sdp);
2620         }
2621         read_unlock_irqrestore(&sg_index_lock, iflags);
2622         return 0;
2623 }
2624
2625 #endif                          /* CONFIG_SCSI_PROC_FS */
2626
2627 module_init(init_sg);
2628 module_exit(exit_sg);