[SCSI] bnx2fc: Broadcom FCoE offload driver
[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
54 #include "scsi.h"
55 #include <scsi/scsi_dbg.h>
56 #include <scsi/scsi_host.h>
57 #include <scsi/scsi_driver.h>
58 #include <scsi/scsi_ioctl.h>
59 #include <scsi/sg.h>
60
61 #include "scsi_logging.h"
62
63 #ifdef CONFIG_SCSI_PROC_FS
64 #include <linux/proc_fs.h>
65 static char *sg_version_date = "20061027";
66
67 static int sg_proc_init(void);
68 static void sg_proc_cleanup(void);
69 #endif
70
71 #define SG_ALLOW_DIO_DEF 0
72
73 #define SG_MAX_DEVS 32768
74
75 /*
76  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
77  * Then when using 32 bit integers x * m may overflow during the calculation.
78  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
79  * calculates the same, but prevents the overflow when both m and d
80  * are "small" numbers (like HZ and USER_HZ).
81  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
82  * in 32 bits.
83  */
84 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
85
86 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
87
88 int sg_big_buff = SG_DEF_RESERVED_SIZE;
89 /* N.B. This variable is readable and writeable via
90    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
91    of this size (or less if there is not enough memory) will be reserved
92    for use by this file descriptor. [Deprecated usage: this variable is also
93    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
94    the kernel (i.e. it is not a module).] */
95 static int def_reserved_size = -1;      /* picks up init parameter */
96 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
97
98 static int scatter_elem_sz = SG_SCATTER_SZ;
99 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
100
101 #define SG_SECTOR_SZ 512
102
103 static int sg_add(struct device *, struct class_interface *);
104 static void sg_remove(struct device *, struct class_interface *);
105
106 static DEFINE_MUTEX(sg_mutex);
107
108 static DEFINE_IDR(sg_index_idr);
109 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
110                                                            file descriptor list for device */
111
112 static struct class_interface sg_interface = {
113         .add_dev        = sg_add,
114         .remove_dev     = sg_remove,
115 };
116
117 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
118         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
119         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
120         unsigned bufflen;       /* Size of (aggregate) data buffer */
121         struct page **pages;
122         int page_order;
123         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
124         unsigned char cmd_opcode; /* first byte of command */
125 } Sg_scatter_hold;
126
127 struct sg_device;               /* forward declarations */
128 struct sg_fd;
129
130 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
131         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
132         struct sg_fd *parentfp; /* NULL -> not in use */
133         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
134         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
135         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
136         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
137         char orphan;            /* 1 -> drop on sight, 0 -> normal */
138         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
139         volatile char done;     /* 0->before bh, 1->before read, 2->read */
140         struct request *rq;
141         struct bio *bio;
142         struct execute_work ew;
143 } Sg_request;
144
145 typedef struct sg_fd {          /* holds the state of a file descriptor */
146         struct list_head sfd_siblings;
147         struct sg_device *parentdp;     /* owning device */
148         wait_queue_head_t read_wait;    /* queue read until command done */
149         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
150         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
151         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
152         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
153         unsigned save_scat_len; /* original length of trunc. scat. element */
154         Sg_request *headrp;     /* head of request slist, NULL->empty */
155         struct fasync_struct *async_qp; /* used by asynchronous notification */
156         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
157         char low_dma;           /* as in parent but possibly overridden to 1 */
158         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
159         volatile char closed;   /* 1 -> fd closed but request(s) outstanding */
160         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
161         char next_cmd_len;      /* 0 -> automatic (def), >0 -> use on next write() */
162         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
163         char mmap_called;       /* 0 -> mmap() never called on this fd */
164         struct kref f_ref;
165         struct execute_work ew;
166 } Sg_fd;
167
168 typedef struct sg_device { /* holds the state of each scsi generic device */
169         struct scsi_device *device;
170         wait_queue_head_t o_excl_wait;  /* queue open() when O_EXCL in use */
171         int sg_tablesize;       /* adapter's max scatter-gather table size */
172         u32 index;              /* device index number */
173         struct list_head sfds;
174         volatile char detached; /* 0->attached, 1->detached pending removal */
175         volatile char exclude;  /* opened for exclusive access */
176         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
177         struct gendisk *disk;
178         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
179         struct kref d_ref;
180 } Sg_device;
181
182 /* tasklet or soft irq callback */
183 static void sg_rq_end_io(struct request *rq, int uptodate);
184 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
185 static int sg_finish_rem_req(Sg_request * srp);
186 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
187 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
188                            Sg_request * srp);
189 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
190                         const char __user *buf, size_t count, int blocking,
191                         int read_only, int sg_io_owned, Sg_request **o_srp);
192 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
193                            unsigned char *cmnd, int timeout, int blocking);
194 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
195 static void sg_remove_scat(Sg_scatter_hold * schp);
196 static void sg_build_reserve(Sg_fd * sfp, int req_size);
197 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
198 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
199 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
200 static void sg_remove_sfp(struct kref *);
201 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
202 static Sg_request *sg_add_request(Sg_fd * sfp);
203 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
204 static int sg_res_in_use(Sg_fd * sfp);
205 static Sg_device *sg_get_dev(int dev);
206 static void sg_put_dev(Sg_device *sdp);
207
208 #define SZ_SG_HEADER sizeof(struct sg_header)
209 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
210 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
211 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
212
213 static int sg_allow_access(struct file *filp, unsigned char *cmd)
214 {
215         struct sg_fd *sfp = filp->private_data;
216
217         if (sfp->parentdp->device->type == TYPE_SCANNER)
218                 return 0;
219
220         return blk_verify_command(cmd, filp->f_mode & FMODE_WRITE);
221 }
222
223 static int
224 sg_open(struct inode *inode, struct file *filp)
225 {
226         int dev = iminor(inode);
227         int flags = filp->f_flags;
228         struct request_queue *q;
229         Sg_device *sdp;
230         Sg_fd *sfp;
231         int res;
232         int retval;
233
234         mutex_lock(&sg_mutex);
235         nonseekable_open(inode, filp);
236         SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
237         sdp = sg_get_dev(dev);
238         if (IS_ERR(sdp)) {
239                 retval = PTR_ERR(sdp);
240                 sdp = NULL;
241                 goto sg_put;
242         }
243
244         /* This driver's module count bumped by fops_get in <linux/fs.h> */
245         /* Prevent the device driver from vanishing while we sleep */
246         retval = scsi_device_get(sdp->device);
247         if (retval)
248                 goto sg_put;
249
250         retval = scsi_autopm_get_device(sdp->device);
251         if (retval)
252                 goto sdp_put;
253
254         if (!((flags & O_NONBLOCK) ||
255               scsi_block_when_processing_errors(sdp->device))) {
256                 retval = -ENXIO;
257                 /* we are in error recovery for this device */
258                 goto error_out;
259         }
260
261         if (flags & O_EXCL) {
262                 if (O_RDONLY == (flags & O_ACCMODE)) {
263                         retval = -EPERM; /* Can't lock it with read only access */
264                         goto error_out;
265                 }
266                 if (!list_empty(&sdp->sfds) && (flags & O_NONBLOCK)) {
267                         retval = -EBUSY;
268                         goto error_out;
269                 }
270                 res = 0;
271                 __wait_event_interruptible(sdp->o_excl_wait,
272                                            ((!list_empty(&sdp->sfds) || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
273                 if (res) {
274                         retval = res;   /* -ERESTARTSYS because signal hit process */
275                         goto error_out;
276                 }
277         } else if (sdp->exclude) {      /* some other fd has an exclusive lock on dev */
278                 if (flags & O_NONBLOCK) {
279                         retval = -EBUSY;
280                         goto error_out;
281                 }
282                 res = 0;
283                 __wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
284                                            res);
285                 if (res) {
286                         retval = res;   /* -ERESTARTSYS because signal hit process */
287                         goto error_out;
288                 }
289         }
290         if (sdp->detached) {
291                 retval = -ENODEV;
292                 goto error_out;
293         }
294         if (list_empty(&sdp->sfds)) {   /* no existing opens on this device */
295                 sdp->sgdebug = 0;
296                 q = sdp->device->request_queue;
297                 sdp->sg_tablesize = queue_max_segments(q);
298         }
299         if ((sfp = sg_add_sfp(sdp, dev)))
300                 filp->private_data = sfp;
301         else {
302                 if (flags & O_EXCL) {
303                         sdp->exclude = 0;       /* undo if error */
304                         wake_up_interruptible(&sdp->o_excl_wait);
305                 }
306                 retval = -ENOMEM;
307                 goto error_out;
308         }
309         retval = 0;
310 error_out:
311         if (retval) {
312                 scsi_autopm_put_device(sdp->device);
313 sdp_put:
314                 scsi_device_put(sdp->device);
315         }
316 sg_put:
317         if (sdp)
318                 sg_put_dev(sdp);
319         mutex_unlock(&sg_mutex);
320         return retval;
321 }
322
323 /* Following function was formerly called 'sg_close' */
324 static int
325 sg_release(struct inode *inode, struct file *filp)
326 {
327         Sg_device *sdp;
328         Sg_fd *sfp;
329
330         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
331                 return -ENXIO;
332         SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
333
334         sfp->closed = 1;
335
336         sdp->exclude = 0;
337         wake_up_interruptible(&sdp->o_excl_wait);
338
339         scsi_autopm_put_device(sdp->device);
340         kref_put(&sfp->f_ref, sg_remove_sfp);
341         return 0;
342 }
343
344 static ssize_t
345 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
346 {
347         Sg_device *sdp;
348         Sg_fd *sfp;
349         Sg_request *srp;
350         int req_pack_id = -1;
351         sg_io_hdr_t *hp;
352         struct sg_header *old_hdr = NULL;
353         int retval = 0;
354
355         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
356                 return -ENXIO;
357         SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
358                                    sdp->disk->disk_name, (int) count));
359
360         if (!access_ok(VERIFY_WRITE, buf, count))
361                 return -EFAULT;
362         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
363                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
364                 if (!old_hdr)
365                         return -ENOMEM;
366                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
367                         retval = -EFAULT;
368                         goto free_old_hdr;
369                 }
370                 if (old_hdr->reply_len < 0) {
371                         if (count >= SZ_SG_IO_HDR) {
372                                 sg_io_hdr_t *new_hdr;
373                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
374                                 if (!new_hdr) {
375                                         retval = -ENOMEM;
376                                         goto free_old_hdr;
377                                 }
378                                 retval =__copy_from_user
379                                     (new_hdr, buf, SZ_SG_IO_HDR);
380                                 req_pack_id = new_hdr->pack_id;
381                                 kfree(new_hdr);
382                                 if (retval) {
383                                         retval = -EFAULT;
384                                         goto free_old_hdr;
385                                 }
386                         }
387                 } else
388                         req_pack_id = old_hdr->pack_id;
389         }
390         srp = sg_get_rq_mark(sfp, req_pack_id);
391         if (!srp) {             /* now wait on packet to arrive */
392                 if (sdp->detached) {
393                         retval = -ENODEV;
394                         goto free_old_hdr;
395                 }
396                 if (filp->f_flags & O_NONBLOCK) {
397                         retval = -EAGAIN;
398                         goto free_old_hdr;
399                 }
400                 while (1) {
401                         retval = 0; /* following macro beats race condition */
402                         __wait_event_interruptible(sfp->read_wait,
403                                 (sdp->detached ||
404                                 (srp = sg_get_rq_mark(sfp, req_pack_id))), 
405                                 retval);
406                         if (sdp->detached) {
407                                 retval = -ENODEV;
408                                 goto free_old_hdr;
409                         }
410                         if (0 == retval)
411                                 break;
412
413                         /* -ERESTARTSYS as signal hit process */
414                         goto free_old_hdr;
415                 }
416         }
417         if (srp->header.interface_id != '\0') {
418                 retval = sg_new_read(sfp, buf, count, srp);
419                 goto free_old_hdr;
420         }
421
422         hp = &srp->header;
423         if (old_hdr == NULL) {
424                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
425                 if (! old_hdr) {
426                         retval = -ENOMEM;
427                         goto free_old_hdr;
428                 }
429         }
430         memset(old_hdr, 0, SZ_SG_HEADER);
431         old_hdr->reply_len = (int) hp->timeout;
432         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
433         old_hdr->pack_id = hp->pack_id;
434         old_hdr->twelve_byte =
435             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
436         old_hdr->target_status = hp->masked_status;
437         old_hdr->host_status = hp->host_status;
438         old_hdr->driver_status = hp->driver_status;
439         if ((CHECK_CONDITION & hp->masked_status) ||
440             (DRIVER_SENSE & hp->driver_status))
441                 memcpy(old_hdr->sense_buffer, srp->sense_b,
442                        sizeof (old_hdr->sense_buffer));
443         switch (hp->host_status) {
444         /* This setup of 'result' is for backward compatibility and is best
445            ignored by the user who should use target, host + driver status */
446         case DID_OK:
447         case DID_PASSTHROUGH:
448         case DID_SOFT_ERROR:
449                 old_hdr->result = 0;
450                 break;
451         case DID_NO_CONNECT:
452         case DID_BUS_BUSY:
453         case DID_TIME_OUT:
454                 old_hdr->result = EBUSY;
455                 break;
456         case DID_BAD_TARGET:
457         case DID_ABORT:
458         case DID_PARITY:
459         case DID_RESET:
460         case DID_BAD_INTR:
461                 old_hdr->result = EIO;
462                 break;
463         case DID_ERROR:
464                 old_hdr->result = (srp->sense_b[0] == 0 && 
465                                   hp->masked_status == GOOD) ? 0 : EIO;
466                 break;
467         default:
468                 old_hdr->result = EIO;
469                 break;
470         }
471
472         /* Now copy the result back to the user buffer.  */
473         if (count >= SZ_SG_HEADER) {
474                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
475                         retval = -EFAULT;
476                         goto free_old_hdr;
477                 }
478                 buf += SZ_SG_HEADER;
479                 if (count > old_hdr->reply_len)
480                         count = old_hdr->reply_len;
481                 if (count > SZ_SG_HEADER) {
482                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
483                                 retval = -EFAULT;
484                                 goto free_old_hdr;
485                         }
486                 }
487         } else
488                 count = (old_hdr->result == 0) ? 0 : -EIO;
489         sg_finish_rem_req(srp);
490         retval = count;
491 free_old_hdr:
492         kfree(old_hdr);
493         return retval;
494 }
495
496 static ssize_t
497 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
498 {
499         sg_io_hdr_t *hp = &srp->header;
500         int err = 0;
501         int len;
502
503         if (count < SZ_SG_IO_HDR) {
504                 err = -EINVAL;
505                 goto err_out;
506         }
507         hp->sb_len_wr = 0;
508         if ((hp->mx_sb_len > 0) && hp->sbp) {
509                 if ((CHECK_CONDITION & hp->masked_status) ||
510                     (DRIVER_SENSE & hp->driver_status)) {
511                         int sb_len = SCSI_SENSE_BUFFERSIZE;
512                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
513                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
514                         len = (len > sb_len) ? sb_len : len;
515                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
516                                 err = -EFAULT;
517                                 goto err_out;
518                         }
519                         hp->sb_len_wr = len;
520                 }
521         }
522         if (hp->masked_status || hp->host_status || hp->driver_status)
523                 hp->info |= SG_INFO_CHECK;
524         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
525                 err = -EFAULT;
526                 goto err_out;
527         }
528 err_out:
529         err = sg_finish_rem_req(srp);
530         return (0 == err) ? count : err;
531 }
532
533 static ssize_t
534 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
535 {
536         int mxsize, cmd_size, k;
537         int input_size, blocking;
538         unsigned char opcode;
539         Sg_device *sdp;
540         Sg_fd *sfp;
541         Sg_request *srp;
542         struct sg_header old_hdr;
543         sg_io_hdr_t *hp;
544         unsigned char cmnd[MAX_COMMAND_SIZE];
545
546         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
547                 return -ENXIO;
548         SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
549                                    sdp->disk->disk_name, (int) count));
550         if (sdp->detached)
551                 return -ENODEV;
552         if (!((filp->f_flags & O_NONBLOCK) ||
553               scsi_block_when_processing_errors(sdp->device)))
554                 return -ENXIO;
555
556         if (!access_ok(VERIFY_READ, buf, count))
557                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
558         if (count < SZ_SG_HEADER)
559                 return -EIO;
560         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
561                 return -EFAULT;
562         blocking = !(filp->f_flags & O_NONBLOCK);
563         if (old_hdr.reply_len < 0)
564                 return sg_new_write(sfp, filp, buf, count,
565                                     blocking, 0, 0, NULL);
566         if (count < (SZ_SG_HEADER + 6))
567                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
568
569         if (!(srp = sg_add_request(sfp))) {
570                 SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
571                 return -EDOM;
572         }
573         buf += SZ_SG_HEADER;
574         __get_user(opcode, buf);
575         if (sfp->next_cmd_len > 0) {
576                 if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
577                         SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
578                         sfp->next_cmd_len = 0;
579                         sg_remove_request(sfp, srp);
580                         return -EIO;
581                 }
582                 cmd_size = sfp->next_cmd_len;
583                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
584         } else {
585                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
586                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
587                         cmd_size = 12;
588         }
589         SCSI_LOG_TIMEOUT(4, printk(
590                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
591 /* Determine buffer size.  */
592         input_size = count - cmd_size;
593         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
594         mxsize -= SZ_SG_HEADER;
595         input_size -= SZ_SG_HEADER;
596         if (input_size < 0) {
597                 sg_remove_request(sfp, srp);
598                 return -EIO;    /* User did not pass enough bytes for this command. */
599         }
600         hp = &srp->header;
601         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
602         hp->cmd_len = (unsigned char) cmd_size;
603         hp->iovec_count = 0;
604         hp->mx_sb_len = 0;
605         if (input_size > 0)
606                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
607                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
608         else
609                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
610         hp->dxfer_len = mxsize;
611         if (hp->dxfer_direction == SG_DXFER_TO_DEV)
612                 hp->dxferp = (char __user *)buf + cmd_size;
613         else
614                 hp->dxferp = NULL;
615         hp->sbp = NULL;
616         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
617         hp->flags = input_size; /* structure abuse ... */
618         hp->pack_id = old_hdr.pack_id;
619         hp->usr_ptr = NULL;
620         if (__copy_from_user(cmnd, buf, cmd_size))
621                 return -EFAULT;
622         /*
623          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
624          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
625          * is a non-zero input_size, so emit a warning.
626          */
627         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
628                 static char cmd[TASK_COMM_LEN];
629                 if (strcmp(current->comm, cmd) && printk_ratelimit()) {
630                         printk(KERN_WARNING
631                                "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
632                                "guessing data in;\n   "
633                                "program %s not setting count and/or reply_len properly\n",
634                                old_hdr.reply_len - (int)SZ_SG_HEADER,
635                                input_size, (unsigned int) cmnd[0],
636                                current->comm);
637                         strcpy(cmd, current->comm);
638                 }
639         }
640         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
641         return (k < 0) ? k : count;
642 }
643
644 static ssize_t
645 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
646                  size_t count, int blocking, int read_only, int sg_io_owned,
647                  Sg_request **o_srp)
648 {
649         int k;
650         Sg_request *srp;
651         sg_io_hdr_t *hp;
652         unsigned char cmnd[MAX_COMMAND_SIZE];
653         int timeout;
654         unsigned long ul_timeout;
655
656         if (count < SZ_SG_IO_HDR)
657                 return -EINVAL;
658         if (!access_ok(VERIFY_READ, buf, count))
659                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
660
661         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
662         if (!(srp = sg_add_request(sfp))) {
663                 SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
664                 return -EDOM;
665         }
666         srp->sg_io_owned = sg_io_owned;
667         hp = &srp->header;
668         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
669                 sg_remove_request(sfp, srp);
670                 return -EFAULT;
671         }
672         if (hp->interface_id != 'S') {
673                 sg_remove_request(sfp, srp);
674                 return -ENOSYS;
675         }
676         if (hp->flags & SG_FLAG_MMAP_IO) {
677                 if (hp->dxfer_len > sfp->reserve.bufflen) {
678                         sg_remove_request(sfp, srp);
679                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
680                 }
681                 if (hp->flags & SG_FLAG_DIRECT_IO) {
682                         sg_remove_request(sfp, srp);
683                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
684                 }
685                 if (sg_res_in_use(sfp)) {
686                         sg_remove_request(sfp, srp);
687                         return -EBUSY;  /* reserve buffer already being used */
688                 }
689         }
690         ul_timeout = msecs_to_jiffies(srp->header.timeout);
691         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
692         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
693                 sg_remove_request(sfp, srp);
694                 return -EMSGSIZE;
695         }
696         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
697                 sg_remove_request(sfp, srp);
698                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
699         }
700         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
701                 sg_remove_request(sfp, srp);
702                 return -EFAULT;
703         }
704         if (read_only && sg_allow_access(file, cmnd)) {
705                 sg_remove_request(sfp, srp);
706                 return -EPERM;
707         }
708         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
709         if (k < 0)
710                 return k;
711         if (o_srp)
712                 *o_srp = srp;
713         return count;
714 }
715
716 static int
717 sg_common_write(Sg_fd * sfp, Sg_request * srp,
718                 unsigned char *cmnd, int timeout, int blocking)
719 {
720         int k, data_dir;
721         Sg_device *sdp = sfp->parentdp;
722         sg_io_hdr_t *hp = &srp->header;
723
724         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
725         hp->status = 0;
726         hp->masked_status = 0;
727         hp->msg_status = 0;
728         hp->info = 0;
729         hp->host_status = 0;
730         hp->driver_status = 0;
731         hp->resid = 0;
732         SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
733                           (int) cmnd[0], (int) hp->cmd_len));
734
735         k = sg_start_req(srp, cmnd);
736         if (k) {
737                 SCSI_LOG_TIMEOUT(1, printk("sg_common_write: start_req err=%d\n", k));
738                 sg_finish_rem_req(srp);
739                 return k;       /* probably out of space --> ENOMEM */
740         }
741         if (sdp->detached) {
742                 if (srp->bio)
743                         blk_end_request_all(srp->rq, -EIO);
744                 sg_finish_rem_req(srp);
745                 return -ENODEV;
746         }
747
748         switch (hp->dxfer_direction) {
749         case SG_DXFER_TO_FROM_DEV:
750         case SG_DXFER_FROM_DEV:
751                 data_dir = DMA_FROM_DEVICE;
752                 break;
753         case SG_DXFER_TO_DEV:
754                 data_dir = DMA_TO_DEVICE;
755                 break;
756         case SG_DXFER_UNKNOWN:
757                 data_dir = DMA_BIDIRECTIONAL;
758                 break;
759         default:
760                 data_dir = DMA_NONE;
761                 break;
762         }
763         hp->duration = jiffies_to_msecs(jiffies);
764
765         srp->rq->timeout = timeout;
766         kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
767         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
768                               srp->rq, 1, sg_rq_end_io);
769         return 0;
770 }
771
772 static int
773 sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
774 {
775         void __user *p = (void __user *)arg;
776         int __user *ip = p;
777         int result, val, read_only;
778         Sg_device *sdp;
779         Sg_fd *sfp;
780         Sg_request *srp;
781         unsigned long iflags;
782
783         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
784                 return -ENXIO;
785
786         SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
787                                    sdp->disk->disk_name, (int) cmd_in));
788         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
789
790         switch (cmd_in) {
791         case SG_IO:
792                 {
793                         int blocking = 1;       /* ignore O_NONBLOCK flag */
794
795                         if (sdp->detached)
796                                 return -ENODEV;
797                         if (!scsi_block_when_processing_errors(sdp->device))
798                                 return -ENXIO;
799                         if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
800                                 return -EFAULT;
801                         result =
802                             sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
803                                          blocking, read_only, 1, &srp);
804                         if (result < 0)
805                                 return result;
806                         while (1) {
807                                 result = 0;     /* following macro to beat race condition */
808                                 __wait_event_interruptible(sfp->read_wait,
809                                         (srp->done || sdp->detached),
810                                         result);
811                                 if (sdp->detached)
812                                         return -ENODEV;
813                                 write_lock_irq(&sfp->rq_list_lock);
814                                 if (srp->done) {
815                                         srp->done = 2;
816                                         write_unlock_irq(&sfp->rq_list_lock);
817                                         break;
818                                 }
819                                 srp->orphan = 1;
820                                 write_unlock_irq(&sfp->rq_list_lock);
821                                 return result;  /* -ERESTARTSYS because signal hit process */
822                         }
823                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
824                         return (result < 0) ? result : 0;
825                 }
826         case SG_SET_TIMEOUT:
827                 result = get_user(val, ip);
828                 if (result)
829                         return result;
830                 if (val < 0)
831                         return -EIO;
832                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
833                     val = MULDIV (INT_MAX, USER_HZ, HZ);
834                 sfp->timeout_user = val;
835                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
836
837                 return 0;
838         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
839                                 /* strange ..., for backward compatibility */
840                 return sfp->timeout_user;
841         case SG_SET_FORCE_LOW_DMA:
842                 result = get_user(val, ip);
843                 if (result)
844                         return result;
845                 if (val) {
846                         sfp->low_dma = 1;
847                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
848                                 val = (int) sfp->reserve.bufflen;
849                                 sg_remove_scat(&sfp->reserve);
850                                 sg_build_reserve(sfp, val);
851                         }
852                 } else {
853                         if (sdp->detached)
854                                 return -ENODEV;
855                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
856                 }
857                 return 0;
858         case SG_GET_LOW_DMA:
859                 return put_user((int) sfp->low_dma, ip);
860         case SG_GET_SCSI_ID:
861                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
862                         return -EFAULT;
863                 else {
864                         sg_scsi_id_t __user *sg_idp = p;
865
866                         if (sdp->detached)
867                                 return -ENODEV;
868                         __put_user((int) sdp->device->host->host_no,
869                                    &sg_idp->host_no);
870                         __put_user((int) sdp->device->channel,
871                                    &sg_idp->channel);
872                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
873                         __put_user((int) sdp->device->lun, &sg_idp->lun);
874                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
875                         __put_user((short) sdp->device->host->cmd_per_lun,
876                                    &sg_idp->h_cmd_per_lun);
877                         __put_user((short) sdp->device->queue_depth,
878                                    &sg_idp->d_queue_depth);
879                         __put_user(0, &sg_idp->unused[0]);
880                         __put_user(0, &sg_idp->unused[1]);
881                         return 0;
882                 }
883         case SG_SET_FORCE_PACK_ID:
884                 result = get_user(val, ip);
885                 if (result)
886                         return result;
887                 sfp->force_packid = val ? 1 : 0;
888                 return 0;
889         case SG_GET_PACK_ID:
890                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
891                         return -EFAULT;
892                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
893                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
894                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
895                                 read_unlock_irqrestore(&sfp->rq_list_lock,
896                                                        iflags);
897                                 __put_user(srp->header.pack_id, ip);
898                                 return 0;
899                         }
900                 }
901                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
902                 __put_user(-1, ip);
903                 return 0;
904         case SG_GET_NUM_WAITING:
905                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
906                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
907                         if ((1 == srp->done) && (!srp->sg_io_owned))
908                                 ++val;
909                 }
910                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
911                 return put_user(val, ip);
912         case SG_GET_SG_TABLESIZE:
913                 return put_user(sdp->sg_tablesize, ip);
914         case SG_SET_RESERVED_SIZE:
915                 result = get_user(val, ip);
916                 if (result)
917                         return result;
918                 if (val < 0)
919                         return -EINVAL;
920                 val = min_t(int, val,
921                             queue_max_sectors(sdp->device->request_queue) * 512);
922                 if (val != sfp->reserve.bufflen) {
923                         if (sg_res_in_use(sfp) || sfp->mmap_called)
924                                 return -EBUSY;
925                         sg_remove_scat(&sfp->reserve);
926                         sg_build_reserve(sfp, val);
927                 }
928                 return 0;
929         case SG_GET_RESERVED_SIZE:
930                 val = min_t(int, sfp->reserve.bufflen,
931                             queue_max_sectors(sdp->device->request_queue) * 512);
932                 return put_user(val, ip);
933         case SG_SET_COMMAND_Q:
934                 result = get_user(val, ip);
935                 if (result)
936                         return result;
937                 sfp->cmd_q = val ? 1 : 0;
938                 return 0;
939         case SG_GET_COMMAND_Q:
940                 return put_user((int) sfp->cmd_q, ip);
941         case SG_SET_KEEP_ORPHAN:
942                 result = get_user(val, ip);
943                 if (result)
944                         return result;
945                 sfp->keep_orphan = val;
946                 return 0;
947         case SG_GET_KEEP_ORPHAN:
948                 return put_user((int) sfp->keep_orphan, ip);
949         case SG_NEXT_CMD_LEN:
950                 result = get_user(val, ip);
951                 if (result)
952                         return result;
953                 sfp->next_cmd_len = (val > 0) ? val : 0;
954                 return 0;
955         case SG_GET_VERSION_NUM:
956                 return put_user(sg_version_num, ip);
957         case SG_GET_ACCESS_COUNT:
958                 /* faked - we don't have a real access count anymore */
959                 val = (sdp->device ? 1 : 0);
960                 return put_user(val, ip);
961         case SG_GET_REQUEST_TABLE:
962                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
963                         return -EFAULT;
964                 else {
965                         sg_req_info_t *rinfo;
966                         unsigned int ms;
967
968                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
969                                                                 GFP_KERNEL);
970                         if (!rinfo)
971                                 return -ENOMEM;
972                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
973                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
974                              ++val, srp = srp ? srp->nextrp : srp) {
975                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
976                                 if (srp) {
977                                         rinfo[val].req_state = srp->done + 1;
978                                         rinfo[val].problem =
979                                             srp->header.masked_status & 
980                                             srp->header.host_status & 
981                                             srp->header.driver_status;
982                                         if (srp->done)
983                                                 rinfo[val].duration =
984                                                         srp->header.duration;
985                                         else {
986                                                 ms = jiffies_to_msecs(jiffies);
987                                                 rinfo[val].duration =
988                                                     (ms > srp->header.duration) ?
989                                                     (ms - srp->header.duration) : 0;
990                                         }
991                                         rinfo[val].orphan = srp->orphan;
992                                         rinfo[val].sg_io_owned =
993                                                         srp->sg_io_owned;
994                                         rinfo[val].pack_id =
995                                                         srp->header.pack_id;
996                                         rinfo[val].usr_ptr =
997                                                         srp->header.usr_ptr;
998                                 }
999                         }
1000                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1001                         result = __copy_to_user(p, rinfo, 
1002                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1003                         result = result ? -EFAULT : 0;
1004                         kfree(rinfo);
1005                         return result;
1006                 }
1007         case SG_EMULATED_HOST:
1008                 if (sdp->detached)
1009                         return -ENODEV;
1010                 return put_user(sdp->device->host->hostt->emulated, ip);
1011         case SG_SCSI_RESET:
1012                 if (sdp->detached)
1013                         return -ENODEV;
1014                 if (filp->f_flags & O_NONBLOCK) {
1015                         if (scsi_host_in_recovery(sdp->device->host))
1016                                 return -EBUSY;
1017                 } else if (!scsi_block_when_processing_errors(sdp->device))
1018                         return -EBUSY;
1019                 result = get_user(val, ip);
1020                 if (result)
1021                         return result;
1022                 if (SG_SCSI_RESET_NOTHING == val)
1023                         return 0;
1024                 switch (val) {
1025                 case SG_SCSI_RESET_DEVICE:
1026                         val = SCSI_TRY_RESET_DEVICE;
1027                         break;
1028                 case SG_SCSI_RESET_TARGET:
1029                         val = SCSI_TRY_RESET_TARGET;
1030                         break;
1031                 case SG_SCSI_RESET_BUS:
1032                         val = SCSI_TRY_RESET_BUS;
1033                         break;
1034                 case SG_SCSI_RESET_HOST:
1035                         val = SCSI_TRY_RESET_HOST;
1036                         break;
1037                 default:
1038                         return -EINVAL;
1039                 }
1040                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1041                         return -EACCES;
1042                 return (scsi_reset_provider(sdp->device, val) ==
1043                         SUCCESS) ? 0 : -EIO;
1044         case SCSI_IOCTL_SEND_COMMAND:
1045                 if (sdp->detached)
1046                         return -ENODEV;
1047                 if (read_only) {
1048                         unsigned char opcode = WRITE_6;
1049                         Scsi_Ioctl_Command __user *siocp = p;
1050
1051                         if (copy_from_user(&opcode, siocp->data, 1))
1052                                 return -EFAULT;
1053                         if (sg_allow_access(filp, &opcode))
1054                                 return -EPERM;
1055                 }
1056                 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1057         case SG_SET_DEBUG:
1058                 result = get_user(val, ip);
1059                 if (result)
1060                         return result;
1061                 sdp->sgdebug = (char) val;
1062                 return 0;
1063         case SCSI_IOCTL_GET_IDLUN:
1064         case SCSI_IOCTL_GET_BUS_NUMBER:
1065         case SCSI_IOCTL_PROBE_HOST:
1066         case SG_GET_TRANSFORM:
1067                 if (sdp->detached)
1068                         return -ENODEV;
1069                 return scsi_ioctl(sdp->device, cmd_in, p);
1070         case BLKSECTGET:
1071                 return put_user(queue_max_sectors(sdp->device->request_queue) * 512,
1072                                 ip);
1073         case BLKTRACESETUP:
1074                 return blk_trace_setup(sdp->device->request_queue,
1075                                        sdp->disk->disk_name,
1076                                        MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1077                                        NULL,
1078                                        (char *)arg);
1079         case BLKTRACESTART:
1080                 return blk_trace_startstop(sdp->device->request_queue, 1);
1081         case BLKTRACESTOP:
1082                 return blk_trace_startstop(sdp->device->request_queue, 0);
1083         case BLKTRACETEARDOWN:
1084                 return blk_trace_remove(sdp->device->request_queue);
1085         default:
1086                 if (read_only)
1087                         return -EPERM;  /* don't know so take safe approach */
1088                 return scsi_ioctl(sdp->device, cmd_in, p);
1089         }
1090 }
1091
1092 static long
1093 sg_unlocked_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1094 {
1095         int ret;
1096
1097         mutex_lock(&sg_mutex);
1098         ret = sg_ioctl(filp, cmd_in, arg);
1099         mutex_unlock(&sg_mutex);
1100
1101         return ret;
1102 }
1103
1104 #ifdef CONFIG_COMPAT
1105 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1106 {
1107         Sg_device *sdp;
1108         Sg_fd *sfp;
1109         struct scsi_device *sdev;
1110
1111         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1112                 return -ENXIO;
1113
1114         sdev = sdp->device;
1115         if (sdev->host->hostt->compat_ioctl) { 
1116                 int ret;
1117
1118                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1119
1120                 return ret;
1121         }
1122         
1123         return -ENOIOCTLCMD;
1124 }
1125 #endif
1126
1127 static unsigned int
1128 sg_poll(struct file *filp, poll_table * wait)
1129 {
1130         unsigned int res = 0;
1131         Sg_device *sdp;
1132         Sg_fd *sfp;
1133         Sg_request *srp;
1134         int count = 0;
1135         unsigned long iflags;
1136
1137         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1138             || sfp->closed)
1139                 return POLLERR;
1140         poll_wait(filp, &sfp->read_wait, wait);
1141         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1142         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1143                 /* if any read waiting, flag it */
1144                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1145                         res = POLLIN | POLLRDNORM;
1146                 ++count;
1147         }
1148         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1149
1150         if (sdp->detached)
1151                 res |= POLLHUP;
1152         else if (!sfp->cmd_q) {
1153                 if (0 == count)
1154                         res |= POLLOUT | POLLWRNORM;
1155         } else if (count < SG_MAX_QUEUE)
1156                 res |= POLLOUT | POLLWRNORM;
1157         SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1158                                    sdp->disk->disk_name, (int) res));
1159         return res;
1160 }
1161
1162 static int
1163 sg_fasync(int fd, struct file *filp, int mode)
1164 {
1165         Sg_device *sdp;
1166         Sg_fd *sfp;
1167
1168         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1169                 return -ENXIO;
1170         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1171                                    sdp->disk->disk_name, mode));
1172
1173         return fasync_helper(fd, filp, mode, &sfp->async_qp);
1174 }
1175
1176 static int
1177 sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1178 {
1179         Sg_fd *sfp;
1180         unsigned long offset, len, sa;
1181         Sg_scatter_hold *rsv_schp;
1182         int k, length;
1183
1184         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1185                 return VM_FAULT_SIGBUS;
1186         rsv_schp = &sfp->reserve;
1187         offset = vmf->pgoff << PAGE_SHIFT;
1188         if (offset >= rsv_schp->bufflen)
1189                 return VM_FAULT_SIGBUS;
1190         SCSI_LOG_TIMEOUT(3, printk("sg_vma_fault: offset=%lu, scatg=%d\n",
1191                                    offset, rsv_schp->k_use_sg));
1192         sa = vma->vm_start;
1193         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1194         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1195                 len = vma->vm_end - sa;
1196                 len = (len < length) ? len : length;
1197                 if (offset < len) {
1198                         struct page *page = nth_page(rsv_schp->pages[k],
1199                                                      offset >> PAGE_SHIFT);
1200                         get_page(page); /* increment page count */
1201                         vmf->page = page;
1202                         return 0; /* success */
1203                 }
1204                 sa += len;
1205                 offset -= len;
1206         }
1207
1208         return VM_FAULT_SIGBUS;
1209 }
1210
1211 static const struct vm_operations_struct sg_mmap_vm_ops = {
1212         .fault = sg_vma_fault,
1213 };
1214
1215 static int
1216 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1217 {
1218         Sg_fd *sfp;
1219         unsigned long req_sz, len, sa;
1220         Sg_scatter_hold *rsv_schp;
1221         int k, length;
1222
1223         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1224                 return -ENXIO;
1225         req_sz = vma->vm_end - vma->vm_start;
1226         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1227                                    (void *) vma->vm_start, (int) req_sz));
1228         if (vma->vm_pgoff)
1229                 return -EINVAL; /* want no offset */
1230         rsv_schp = &sfp->reserve;
1231         if (req_sz > rsv_schp->bufflen)
1232                 return -ENOMEM; /* cannot map more than reserved buffer */
1233
1234         sa = vma->vm_start;
1235         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1236         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1237                 len = vma->vm_end - sa;
1238                 len = (len < length) ? len : length;
1239                 sa += len;
1240         }
1241
1242         sfp->mmap_called = 1;
1243         vma->vm_flags |= VM_RESERVED;
1244         vma->vm_private_data = sfp;
1245         vma->vm_ops = &sg_mmap_vm_ops;
1246         return 0;
1247 }
1248
1249 static void sg_rq_end_io_usercontext(struct work_struct *work)
1250 {
1251         struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1252         struct sg_fd *sfp = srp->parentfp;
1253
1254         sg_finish_rem_req(srp);
1255         kref_put(&sfp->f_ref, sg_remove_sfp);
1256 }
1257
1258 /*
1259  * This function is a "bottom half" handler that is called by the mid
1260  * level when a command is completed (or has failed).
1261  */
1262 static void sg_rq_end_io(struct request *rq, int uptodate)
1263 {
1264         struct sg_request *srp = rq->end_io_data;
1265         Sg_device *sdp;
1266         Sg_fd *sfp;
1267         unsigned long iflags;
1268         unsigned int ms;
1269         char *sense;
1270         int result, resid, done = 1;
1271
1272         if (WARN_ON(srp->done != 0))
1273                 return;
1274
1275         sfp = srp->parentfp;
1276         if (WARN_ON(sfp == NULL))
1277                 return;
1278
1279         sdp = sfp->parentdp;
1280         if (unlikely(sdp->detached))
1281                 printk(KERN_INFO "sg_rq_end_io: device detached\n");
1282
1283         sense = rq->sense;
1284         result = rq->errors;
1285         resid = rq->resid_len;
1286
1287         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1288                 sdp->disk->disk_name, srp->header.pack_id, result));
1289         srp->header.resid = resid;
1290         ms = jiffies_to_msecs(jiffies);
1291         srp->header.duration = (ms > srp->header.duration) ?
1292                                 (ms - srp->header.duration) : 0;
1293         if (0 != result) {
1294                 struct scsi_sense_hdr sshdr;
1295
1296                 srp->header.status = 0xff & result;
1297                 srp->header.masked_status = status_byte(result);
1298                 srp->header.msg_status = msg_byte(result);
1299                 srp->header.host_status = host_byte(result);
1300                 srp->header.driver_status = driver_byte(result);
1301                 if ((sdp->sgdebug > 0) &&
1302                     ((CHECK_CONDITION == srp->header.masked_status) ||
1303                      (COMMAND_TERMINATED == srp->header.masked_status)))
1304                         __scsi_print_sense("sg_cmd_done", sense,
1305                                            SCSI_SENSE_BUFFERSIZE);
1306
1307                 /* Following if statement is a patch supplied by Eric Youngdale */
1308                 if (driver_byte(result) != 0
1309                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1310                     && !scsi_sense_is_deferred(&sshdr)
1311                     && sshdr.sense_key == UNIT_ATTENTION
1312                     && sdp->device->removable) {
1313                         /* Detected possible disc change. Set the bit - this */
1314                         /* may be used if there are filesystems using this device */
1315                         sdp->device->changed = 1;
1316                 }
1317         }
1318         /* Rely on write phase to clean out srp status values, so no "else" */
1319
1320         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1321         if (unlikely(srp->orphan)) {
1322                 if (sfp->keep_orphan)
1323                         srp->sg_io_owned = 0;
1324                 else
1325                         done = 0;
1326         }
1327         srp->done = done;
1328         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1329
1330         if (likely(done)) {
1331                 /* Now wake up any sg_read() that is waiting for this
1332                  * packet.
1333                  */
1334                 wake_up_interruptible(&sfp->read_wait);
1335                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1336                 kref_put(&sfp->f_ref, sg_remove_sfp);
1337         } else {
1338                 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1339                 schedule_work(&srp->ew.work);
1340         }
1341 }
1342
1343 static const struct file_operations sg_fops = {
1344         .owner = THIS_MODULE,
1345         .read = sg_read,
1346         .write = sg_write,
1347         .poll = sg_poll,
1348         .unlocked_ioctl = sg_unlocked_ioctl,
1349 #ifdef CONFIG_COMPAT
1350         .compat_ioctl = sg_compat_ioctl,
1351 #endif
1352         .open = sg_open,
1353         .mmap = sg_mmap,
1354         .release = sg_release,
1355         .fasync = sg_fasync,
1356         .llseek = no_llseek,
1357 };
1358
1359 static struct class *sg_sysfs_class;
1360
1361 static int sg_sysfs_valid = 0;
1362
1363 static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1364 {
1365         struct request_queue *q = scsidp->request_queue;
1366         Sg_device *sdp;
1367         unsigned long iflags;
1368         int error;
1369         u32 k;
1370
1371         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1372         if (!sdp) {
1373                 printk(KERN_WARNING "kmalloc Sg_device failure\n");
1374                 return ERR_PTR(-ENOMEM);
1375         }
1376
1377         if (!idr_pre_get(&sg_index_idr, GFP_KERNEL)) {
1378                 printk(KERN_WARNING "idr expansion Sg_device failure\n");
1379                 error = -ENOMEM;
1380                 goto out;
1381         }
1382
1383         write_lock_irqsave(&sg_index_lock, iflags);
1384
1385         error = idr_get_new(&sg_index_idr, sdp, &k);
1386         if (error) {
1387                 write_unlock_irqrestore(&sg_index_lock, iflags);
1388                 printk(KERN_WARNING "idr allocation Sg_device failure: %d\n",
1389                        error);
1390                 goto out;
1391         }
1392
1393         if (unlikely(k >= SG_MAX_DEVS))
1394                 goto overflow;
1395
1396         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1397         sprintf(disk->disk_name, "sg%d", k);
1398         disk->first_minor = k;
1399         sdp->disk = disk;
1400         sdp->device = scsidp;
1401         INIT_LIST_HEAD(&sdp->sfds);
1402         init_waitqueue_head(&sdp->o_excl_wait);
1403         sdp->sg_tablesize = queue_max_segments(q);
1404         sdp->index = k;
1405         kref_init(&sdp->d_ref);
1406
1407         write_unlock_irqrestore(&sg_index_lock, iflags);
1408
1409         error = 0;
1410  out:
1411         if (error) {
1412                 kfree(sdp);
1413                 return ERR_PTR(error);
1414         }
1415         return sdp;
1416
1417  overflow:
1418         idr_remove(&sg_index_idr, k);
1419         write_unlock_irqrestore(&sg_index_lock, iflags);
1420         sdev_printk(KERN_WARNING, scsidp,
1421                     "Unable to attach sg device type=%d, minor "
1422                     "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1423         error = -ENODEV;
1424         goto out;
1425 }
1426
1427 static int
1428 sg_add(struct device *cl_dev, struct class_interface *cl_intf)
1429 {
1430         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1431         struct gendisk *disk;
1432         Sg_device *sdp = NULL;
1433         struct cdev * cdev = NULL;
1434         int error;
1435         unsigned long iflags;
1436
1437         disk = alloc_disk(1);
1438         if (!disk) {
1439                 printk(KERN_WARNING "alloc_disk failed\n");
1440                 return -ENOMEM;
1441         }
1442         disk->major = SCSI_GENERIC_MAJOR;
1443
1444         error = -ENOMEM;
1445         cdev = cdev_alloc();
1446         if (!cdev) {
1447                 printk(KERN_WARNING "cdev_alloc failed\n");
1448                 goto out;
1449         }
1450         cdev->owner = THIS_MODULE;
1451         cdev->ops = &sg_fops;
1452
1453         sdp = sg_alloc(disk, scsidp);
1454         if (IS_ERR(sdp)) {
1455                 printk(KERN_WARNING "sg_alloc failed\n");
1456                 error = PTR_ERR(sdp);
1457                 goto out;
1458         }
1459
1460         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1461         if (error)
1462                 goto cdev_add_err;
1463
1464         sdp->cdev = cdev;
1465         if (sg_sysfs_valid) {
1466                 struct device *sg_class_member;
1467
1468                 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1469                                                 MKDEV(SCSI_GENERIC_MAJOR,
1470                                                       sdp->index),
1471                                                 sdp, "%s", disk->disk_name);
1472                 if (IS_ERR(sg_class_member)) {
1473                         printk(KERN_ERR "sg_add: "
1474                                "device_create failed\n");
1475                         error = PTR_ERR(sg_class_member);
1476                         goto cdev_add_err;
1477                 }
1478                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1479                                           &sg_class_member->kobj, "generic");
1480                 if (error)
1481                         printk(KERN_ERR "sg_add: unable to make symlink "
1482                                         "'generic' back to sg%d\n", sdp->index);
1483         } else
1484                 printk(KERN_WARNING "sg_add: sg_sys Invalid\n");
1485
1486         sdev_printk(KERN_NOTICE, scsidp,
1487                     "Attached scsi generic sg%d type %d\n", sdp->index,
1488                     scsidp->type);
1489
1490         dev_set_drvdata(cl_dev, sdp);
1491
1492         return 0;
1493
1494 cdev_add_err:
1495         write_lock_irqsave(&sg_index_lock, iflags);
1496         idr_remove(&sg_index_idr, sdp->index);
1497         write_unlock_irqrestore(&sg_index_lock, iflags);
1498         kfree(sdp);
1499
1500 out:
1501         put_disk(disk);
1502         if (cdev)
1503                 cdev_del(cdev);
1504         return error;
1505 }
1506
1507 static void sg_device_destroy(struct kref *kref)
1508 {
1509         struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1510         unsigned long flags;
1511
1512         /* CAUTION!  Note that the device can still be found via idr_find()
1513          * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1514          * any other cleanup.
1515          */
1516
1517         write_lock_irqsave(&sg_index_lock, flags);
1518         idr_remove(&sg_index_idr, sdp->index);
1519         write_unlock_irqrestore(&sg_index_lock, flags);
1520
1521         SCSI_LOG_TIMEOUT(3,
1522                 printk("sg_device_destroy: %s\n",
1523                         sdp->disk->disk_name));
1524
1525         put_disk(sdp->disk);
1526         kfree(sdp);
1527 }
1528
1529 static void sg_remove(struct device *cl_dev, struct class_interface *cl_intf)
1530 {
1531         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1532         Sg_device *sdp = dev_get_drvdata(cl_dev);
1533         unsigned long iflags;
1534         Sg_fd *sfp;
1535
1536         if (!sdp || sdp->detached)
1537                 return;
1538
1539         SCSI_LOG_TIMEOUT(3, printk("sg_remove: %s\n", sdp->disk->disk_name));
1540
1541         /* Need a write lock to set sdp->detached. */
1542         write_lock_irqsave(&sg_index_lock, iflags);
1543         sdp->detached = 1;
1544         list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1545                 wake_up_interruptible(&sfp->read_wait);
1546                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1547         }
1548         write_unlock_irqrestore(&sg_index_lock, iflags);
1549
1550         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1551         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1552         cdev_del(sdp->cdev);
1553         sdp->cdev = NULL;
1554
1555         sg_put_dev(sdp);
1556 }
1557
1558 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1559 module_param_named(def_reserved_size, def_reserved_size, int,
1560                    S_IRUGO | S_IWUSR);
1561 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1562
1563 MODULE_AUTHOR("Douglas Gilbert");
1564 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1565 MODULE_LICENSE("GPL");
1566 MODULE_VERSION(SG_VERSION_STR);
1567 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1568
1569 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1570                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1571 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1572 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1573
1574 static int __init
1575 init_sg(void)
1576 {
1577         int rc;
1578
1579         if (scatter_elem_sz < PAGE_SIZE) {
1580                 scatter_elem_sz = PAGE_SIZE;
1581                 scatter_elem_sz_prev = scatter_elem_sz;
1582         }
1583         if (def_reserved_size >= 0)
1584                 sg_big_buff = def_reserved_size;
1585         else
1586                 def_reserved_size = sg_big_buff;
1587
1588         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), 
1589                                     SG_MAX_DEVS, "sg");
1590         if (rc)
1591                 return rc;
1592         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1593         if ( IS_ERR(sg_sysfs_class) ) {
1594                 rc = PTR_ERR(sg_sysfs_class);
1595                 goto err_out;
1596         }
1597         sg_sysfs_valid = 1;
1598         rc = scsi_register_interface(&sg_interface);
1599         if (0 == rc) {
1600 #ifdef CONFIG_SCSI_PROC_FS
1601                 sg_proc_init();
1602 #endif                          /* CONFIG_SCSI_PROC_FS */
1603                 return 0;
1604         }
1605         class_destroy(sg_sysfs_class);
1606 err_out:
1607         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1608         return rc;
1609 }
1610
1611 static void __exit
1612 exit_sg(void)
1613 {
1614 #ifdef CONFIG_SCSI_PROC_FS
1615         sg_proc_cleanup();
1616 #endif                          /* CONFIG_SCSI_PROC_FS */
1617         scsi_unregister_interface(&sg_interface);
1618         class_destroy(sg_sysfs_class);
1619         sg_sysfs_valid = 0;
1620         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1621                                  SG_MAX_DEVS);
1622         idr_destroy(&sg_index_idr);
1623 }
1624
1625 static int sg_start_req(Sg_request *srp, unsigned char *cmd)
1626 {
1627         int res;
1628         struct request *rq;
1629         Sg_fd *sfp = srp->parentfp;
1630         sg_io_hdr_t *hp = &srp->header;
1631         int dxfer_len = (int) hp->dxfer_len;
1632         int dxfer_dir = hp->dxfer_direction;
1633         unsigned int iov_count = hp->iovec_count;
1634         Sg_scatter_hold *req_schp = &srp->data;
1635         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1636         struct request_queue *q = sfp->parentdp->device->request_queue;
1637         struct rq_map_data *md, map_data;
1638         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1639
1640         SCSI_LOG_TIMEOUT(4, printk(KERN_INFO "sg_start_req: dxfer_len=%d\n",
1641                                    dxfer_len));
1642
1643         rq = blk_get_request(q, rw, GFP_ATOMIC);
1644         if (!rq)
1645                 return -ENOMEM;
1646
1647         memcpy(rq->cmd, cmd, hp->cmd_len);
1648
1649         rq->cmd_len = hp->cmd_len;
1650         rq->cmd_type = REQ_TYPE_BLOCK_PC;
1651
1652         srp->rq = rq;
1653         rq->end_io_data = srp;
1654         rq->sense = srp->sense_b;
1655         rq->retries = SG_DEFAULT_RETRIES;
1656
1657         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1658                 return 0;
1659
1660         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1661             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1662             !sfp->parentdp->device->host->unchecked_isa_dma &&
1663             blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1664                 md = NULL;
1665         else
1666                 md = &map_data;
1667
1668         if (md) {
1669                 if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen)
1670                         sg_link_reserve(sfp, srp, dxfer_len);
1671                 else {
1672                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1673                         if (res)
1674                                 return res;
1675                 }
1676
1677                 md->pages = req_schp->pages;
1678                 md->page_order = req_schp->page_order;
1679                 md->nr_entries = req_schp->k_use_sg;
1680                 md->offset = 0;
1681                 md->null_mapped = hp->dxferp ? 0 : 1;
1682                 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1683                         md->from_user = 1;
1684                 else
1685                         md->from_user = 0;
1686         }
1687
1688         if (iov_count) {
1689                 int len, size = sizeof(struct sg_iovec) * iov_count;
1690                 struct iovec *iov;
1691
1692                 iov = memdup_user(hp->dxferp, size);
1693                 if (IS_ERR(iov))
1694                         return PTR_ERR(iov);
1695
1696                 len = iov_length(iov, iov_count);
1697                 if (hp->dxfer_len < len) {
1698                         iov_count = iov_shorten(iov, iov_count, hp->dxfer_len);
1699                         len = hp->dxfer_len;
1700                 }
1701
1702                 res = blk_rq_map_user_iov(q, rq, md, (struct sg_iovec *)iov,
1703                                           iov_count,
1704                                           len, GFP_ATOMIC);
1705                 kfree(iov);
1706         } else
1707                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1708                                       hp->dxfer_len, GFP_ATOMIC);
1709
1710         if (!res) {
1711                 srp->bio = rq->bio;
1712
1713                 if (!md) {
1714                         req_schp->dio_in_use = 1;
1715                         hp->info |= SG_INFO_DIRECT_IO;
1716                 }
1717         }
1718         return res;
1719 }
1720
1721 static int sg_finish_rem_req(Sg_request * srp)
1722 {
1723         int ret = 0;
1724
1725         Sg_fd *sfp = srp->parentfp;
1726         Sg_scatter_hold *req_schp = &srp->data;
1727
1728         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1729         if (srp->rq) {
1730                 if (srp->bio)
1731                         ret = blk_rq_unmap_user(srp->bio);
1732
1733                 blk_put_request(srp->rq);
1734         }
1735
1736         if (srp->res_used)
1737                 sg_unlink_reserve(sfp, srp);
1738         else
1739                 sg_remove_scat(req_schp);
1740
1741         sg_remove_request(sfp, srp);
1742
1743         return ret;
1744 }
1745
1746 static int
1747 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1748 {
1749         int sg_bufflen = tablesize * sizeof(struct page *);
1750         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1751
1752         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1753         if (!schp->pages)
1754                 return -ENOMEM;
1755         schp->sglist_len = sg_bufflen;
1756         return tablesize;       /* number of scat_gath elements allocated */
1757 }
1758
1759 static int
1760 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1761 {
1762         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1763         int sg_tablesize = sfp->parentdp->sg_tablesize;
1764         int blk_size = buff_size, order;
1765         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1766
1767         if (blk_size < 0)
1768                 return -EFAULT;
1769         if (0 == blk_size)
1770                 ++blk_size;     /* don't know why */
1771         /* round request up to next highest SG_SECTOR_SZ byte boundary */
1772         blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1773         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1774                                    buff_size, blk_size));
1775
1776         /* N.B. ret_sz carried into this block ... */
1777         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1778         if (mx_sc_elems < 0)
1779                 return mx_sc_elems;     /* most likely -ENOMEM */
1780
1781         num = scatter_elem_sz;
1782         if (unlikely(num != scatter_elem_sz_prev)) {
1783                 if (num < PAGE_SIZE) {
1784                         scatter_elem_sz = PAGE_SIZE;
1785                         scatter_elem_sz_prev = PAGE_SIZE;
1786                 } else
1787                         scatter_elem_sz_prev = num;
1788         }
1789
1790         if (sfp->low_dma)
1791                 gfp_mask |= GFP_DMA;
1792
1793         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1794                 gfp_mask |= __GFP_ZERO;
1795
1796         order = get_order(num);
1797 retry:
1798         ret_sz = 1 << (PAGE_SHIFT + order);
1799
1800         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1801              k++, rem_sz -= ret_sz) {
1802
1803                 num = (rem_sz > scatter_elem_sz_prev) ?
1804                         scatter_elem_sz_prev : rem_sz;
1805
1806                 schp->pages[k] = alloc_pages(gfp_mask, order);
1807                 if (!schp->pages[k])
1808                         goto out;
1809
1810                 if (num == scatter_elem_sz_prev) {
1811                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1812                                 scatter_elem_sz = ret_sz;
1813                                 scatter_elem_sz_prev = ret_sz;
1814                         }
1815                 }
1816
1817                 SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k=%d, num=%d, "
1818                                  "ret_sz=%d\n", k, num, ret_sz));
1819         }               /* end of for loop */
1820
1821         schp->page_order = order;
1822         schp->k_use_sg = k;
1823         SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, "
1824                          "rem_sz=%d\n", k, rem_sz));
1825
1826         schp->bufflen = blk_size;
1827         if (rem_sz > 0) /* must have failed */
1828                 return -ENOMEM;
1829         return 0;
1830 out:
1831         for (i = 0; i < k; i++)
1832                 __free_pages(schp->pages[i], order);
1833
1834         if (--order >= 0)
1835                 goto retry;
1836
1837         return -ENOMEM;
1838 }
1839
1840 static void
1841 sg_remove_scat(Sg_scatter_hold * schp)
1842 {
1843         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1844         if (schp->pages && schp->sglist_len > 0) {
1845                 if (!schp->dio_in_use) {
1846                         int k;
1847
1848                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1849                                 SCSI_LOG_TIMEOUT(5, printk(
1850                                     "sg_remove_scat: k=%d, pg=0x%p\n",
1851                                     k, schp->pages[k]));
1852                                 __free_pages(schp->pages[k], schp->page_order);
1853                         }
1854
1855                         kfree(schp->pages);
1856                 }
1857         }
1858         memset(schp, 0, sizeof (*schp));
1859 }
1860
1861 static int
1862 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1863 {
1864         Sg_scatter_hold *schp = &srp->data;
1865         int k, num;
1866
1867         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
1868                                    num_read_xfer));
1869         if ((!outp) || (num_read_xfer <= 0))
1870                 return 0;
1871
1872         num = 1 << (PAGE_SHIFT + schp->page_order);
1873         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1874                 if (num > num_read_xfer) {
1875                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1876                                            num_read_xfer))
1877                                 return -EFAULT;
1878                         break;
1879                 } else {
1880                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1881                                            num))
1882                                 return -EFAULT;
1883                         num_read_xfer -= num;
1884                         if (num_read_xfer <= 0)
1885                                 break;
1886                         outp += num;
1887                 }
1888         }
1889
1890         return 0;
1891 }
1892
1893 static void
1894 sg_build_reserve(Sg_fd * sfp, int req_size)
1895 {
1896         Sg_scatter_hold *schp = &sfp->reserve;
1897
1898         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
1899         do {
1900                 if (req_size < PAGE_SIZE)
1901                         req_size = PAGE_SIZE;
1902                 if (0 == sg_build_indirect(schp, sfp, req_size))
1903                         return;
1904                 else
1905                         sg_remove_scat(schp);
1906                 req_size >>= 1; /* divide by 2 */
1907         } while (req_size > (PAGE_SIZE / 2));
1908 }
1909
1910 static void
1911 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1912 {
1913         Sg_scatter_hold *req_schp = &srp->data;
1914         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1915         int k, num, rem;
1916
1917         srp->res_used = 1;
1918         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
1919         rem = size;
1920
1921         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1922         for (k = 0; k < rsv_schp->k_use_sg; k++) {
1923                 if (rem <= num) {
1924                         req_schp->k_use_sg = k + 1;
1925                         req_schp->sglist_len = rsv_schp->sglist_len;
1926                         req_schp->pages = rsv_schp->pages;
1927
1928                         req_schp->bufflen = size;
1929                         req_schp->page_order = rsv_schp->page_order;
1930                         break;
1931                 } else
1932                         rem -= num;
1933         }
1934
1935         if (k >= rsv_schp->k_use_sg)
1936                 SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
1937 }
1938
1939 static void
1940 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
1941 {
1942         Sg_scatter_hold *req_schp = &srp->data;
1943
1944         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
1945                                    (int) req_schp->k_use_sg));
1946         req_schp->k_use_sg = 0;
1947         req_schp->bufflen = 0;
1948         req_schp->pages = NULL;
1949         req_schp->page_order = 0;
1950         req_schp->sglist_len = 0;
1951         sfp->save_scat_len = 0;
1952         srp->res_used = 0;
1953 }
1954
1955 static Sg_request *
1956 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
1957 {
1958         Sg_request *resp;
1959         unsigned long iflags;
1960
1961         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1962         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
1963                 /* look for requests that are ready + not SG_IO owned */
1964                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
1965                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
1966                         resp->done = 2; /* guard against other readers */
1967                         break;
1968                 }
1969         }
1970         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1971         return resp;
1972 }
1973
1974 /* always adds to end of list */
1975 static Sg_request *
1976 sg_add_request(Sg_fd * sfp)
1977 {
1978         int k;
1979         unsigned long iflags;
1980         Sg_request *resp;
1981         Sg_request *rp = sfp->req_arr;
1982
1983         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1984         resp = sfp->headrp;
1985         if (!resp) {
1986                 memset(rp, 0, sizeof (Sg_request));
1987                 rp->parentfp = sfp;
1988                 resp = rp;
1989                 sfp->headrp = resp;
1990         } else {
1991                 if (0 == sfp->cmd_q)
1992                         resp = NULL;    /* command queuing disallowed */
1993                 else {
1994                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
1995                                 if (!rp->parentfp)
1996                                         break;
1997                         }
1998                         if (k < SG_MAX_QUEUE) {
1999                                 memset(rp, 0, sizeof (Sg_request));
2000                                 rp->parentfp = sfp;
2001                                 while (resp->nextrp)
2002                                         resp = resp->nextrp;
2003                                 resp->nextrp = rp;
2004                                 resp = rp;
2005                         } else
2006                                 resp = NULL;
2007                 }
2008         }
2009         if (resp) {
2010                 resp->nextrp = NULL;
2011                 resp->header.duration = jiffies_to_msecs(jiffies);
2012         }
2013         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2014         return resp;
2015 }
2016
2017 /* Return of 1 for found; 0 for not found */
2018 static int
2019 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2020 {
2021         Sg_request *prev_rp;
2022         Sg_request *rp;
2023         unsigned long iflags;
2024         int res = 0;
2025
2026         if ((!sfp) || (!srp) || (!sfp->headrp))
2027                 return res;
2028         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2029         prev_rp = sfp->headrp;
2030         if (srp == prev_rp) {
2031                 sfp->headrp = prev_rp->nextrp;
2032                 prev_rp->parentfp = NULL;
2033                 res = 1;
2034         } else {
2035                 while ((rp = prev_rp->nextrp)) {
2036                         if (srp == rp) {
2037                                 prev_rp->nextrp = rp->nextrp;
2038                                 rp->parentfp = NULL;
2039                                 res = 1;
2040                                 break;
2041                         }
2042                         prev_rp = rp;
2043                 }
2044         }
2045         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2046         return res;
2047 }
2048
2049 static Sg_fd *
2050 sg_add_sfp(Sg_device * sdp, int dev)
2051 {
2052         Sg_fd *sfp;
2053         unsigned long iflags;
2054         int bufflen;
2055
2056         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2057         if (!sfp)
2058                 return NULL;
2059
2060         init_waitqueue_head(&sfp->read_wait);
2061         rwlock_init(&sfp->rq_list_lock);
2062
2063         kref_init(&sfp->f_ref);
2064         sfp->timeout = SG_DEFAULT_TIMEOUT;
2065         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2066         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2067         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2068             sdp->device->host->unchecked_isa_dma : 1;
2069         sfp->cmd_q = SG_DEF_COMMAND_Q;
2070         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2071         sfp->parentdp = sdp;
2072         write_lock_irqsave(&sg_index_lock, iflags);
2073         list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2074         write_unlock_irqrestore(&sg_index_lock, iflags);
2075         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2076         if (unlikely(sg_big_buff != def_reserved_size))
2077                 sg_big_buff = def_reserved_size;
2078
2079         bufflen = min_t(int, sg_big_buff,
2080                         queue_max_sectors(sdp->device->request_queue) * 512);
2081         sg_build_reserve(sfp, bufflen);
2082         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2083                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2084
2085         kref_get(&sdp->d_ref);
2086         __module_get(THIS_MODULE);
2087         return sfp;
2088 }
2089
2090 static void sg_remove_sfp_usercontext(struct work_struct *work)
2091 {
2092         struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2093         struct sg_device *sdp = sfp->parentdp;
2094
2095         /* Cleanup any responses which were never read(). */
2096         while (sfp->headrp)
2097                 sg_finish_rem_req(sfp->headrp);
2098
2099         if (sfp->reserve.bufflen > 0) {
2100                 SCSI_LOG_TIMEOUT(6,
2101                         printk("sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2102                                 (int) sfp->reserve.bufflen,
2103                                 (int) sfp->reserve.k_use_sg));
2104                 sg_remove_scat(&sfp->reserve);
2105         }
2106
2107         SCSI_LOG_TIMEOUT(6,
2108                 printk("sg_remove_sfp: %s, sfp=0x%p\n",
2109                         sdp->disk->disk_name,
2110                         sfp));
2111         kfree(sfp);
2112
2113         scsi_device_put(sdp->device);
2114         sg_put_dev(sdp);
2115         module_put(THIS_MODULE);
2116 }
2117
2118 static void sg_remove_sfp(struct kref *kref)
2119 {
2120         struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2121         struct sg_device *sdp = sfp->parentdp;
2122         unsigned long iflags;
2123
2124         write_lock_irqsave(&sg_index_lock, iflags);
2125         list_del(&sfp->sfd_siblings);
2126         write_unlock_irqrestore(&sg_index_lock, iflags);
2127         wake_up_interruptible(&sdp->o_excl_wait);
2128
2129         INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2130         schedule_work(&sfp->ew.work);
2131 }
2132
2133 static int
2134 sg_res_in_use(Sg_fd * sfp)
2135 {
2136         const Sg_request *srp;
2137         unsigned long iflags;
2138
2139         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2140         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2141                 if (srp->res_used)
2142                         break;
2143         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2144         return srp ? 1 : 0;
2145 }
2146
2147 #ifdef CONFIG_SCSI_PROC_FS
2148 static int
2149 sg_idr_max_id(int id, void *p, void *data)
2150 {
2151         int *k = data;
2152
2153         if (*k < id)
2154                 *k = id;
2155
2156         return 0;
2157 }
2158
2159 static int
2160 sg_last_dev(void)
2161 {
2162         int k = -1;
2163         unsigned long iflags;
2164
2165         read_lock_irqsave(&sg_index_lock, iflags);
2166         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2167         read_unlock_irqrestore(&sg_index_lock, iflags);
2168         return k + 1;           /* origin 1 */
2169 }
2170 #endif
2171
2172 /* must be called with sg_index_lock held */
2173 static Sg_device *sg_lookup_dev(int dev)
2174 {
2175         return idr_find(&sg_index_idr, dev);
2176 }
2177
2178 static Sg_device *sg_get_dev(int dev)
2179 {
2180         struct sg_device *sdp;
2181         unsigned long flags;
2182
2183         read_lock_irqsave(&sg_index_lock, flags);
2184         sdp = sg_lookup_dev(dev);
2185         if (!sdp)
2186                 sdp = ERR_PTR(-ENXIO);
2187         else if (sdp->detached) {
2188                 /* If sdp->detached, then the refcount may already be 0, in
2189                  * which case it would be a bug to do kref_get().
2190                  */
2191                 sdp = ERR_PTR(-ENODEV);
2192         } else
2193                 kref_get(&sdp->d_ref);
2194         read_unlock_irqrestore(&sg_index_lock, flags);
2195
2196         return sdp;
2197 }
2198
2199 static void sg_put_dev(struct sg_device *sdp)
2200 {
2201         kref_put(&sdp->d_ref, sg_device_destroy);
2202 }
2203
2204 #ifdef CONFIG_SCSI_PROC_FS
2205
2206 static struct proc_dir_entry *sg_proc_sgp = NULL;
2207
2208 static char sg_proc_sg_dirname[] = "scsi/sg";
2209
2210 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2211
2212 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2213 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2214                                   size_t count, loff_t *off);
2215 static const struct file_operations adio_fops = {
2216         .owner = THIS_MODULE,
2217         .open = sg_proc_single_open_adio,
2218         .read = seq_read,
2219         .llseek = seq_lseek,
2220         .write = sg_proc_write_adio,
2221         .release = single_release,
2222 };
2223
2224 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2225 static ssize_t sg_proc_write_dressz(struct file *filp, 
2226                 const char __user *buffer, size_t count, loff_t *off);
2227 static const struct file_operations dressz_fops = {
2228         .owner = THIS_MODULE,
2229         .open = sg_proc_single_open_dressz,
2230         .read = seq_read,
2231         .llseek = seq_lseek,
2232         .write = sg_proc_write_dressz,
2233         .release = single_release,
2234 };
2235
2236 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2237 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2238 static const struct file_operations version_fops = {
2239         .owner = THIS_MODULE,
2240         .open = sg_proc_single_open_version,
2241         .read = seq_read,
2242         .llseek = seq_lseek,
2243         .release = single_release,
2244 };
2245
2246 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2247 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2248 static const struct file_operations devhdr_fops = {
2249         .owner = THIS_MODULE,
2250         .open = sg_proc_single_open_devhdr,
2251         .read = seq_read,
2252         .llseek = seq_lseek,
2253         .release = single_release,
2254 };
2255
2256 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2257 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2258 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2259 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2260 static void dev_seq_stop(struct seq_file *s, void *v);
2261 static const struct file_operations dev_fops = {
2262         .owner = THIS_MODULE,
2263         .open = sg_proc_open_dev,
2264         .read = seq_read,
2265         .llseek = seq_lseek,
2266         .release = seq_release,
2267 };
2268 static const struct seq_operations dev_seq_ops = {
2269         .start = dev_seq_start,
2270         .next  = dev_seq_next,
2271         .stop  = dev_seq_stop,
2272         .show  = sg_proc_seq_show_dev,
2273 };
2274
2275 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2276 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2277 static const struct file_operations devstrs_fops = {
2278         .owner = THIS_MODULE,
2279         .open = sg_proc_open_devstrs,
2280         .read = seq_read,
2281         .llseek = seq_lseek,
2282         .release = seq_release,
2283 };
2284 static const struct seq_operations devstrs_seq_ops = {
2285         .start = dev_seq_start,
2286         .next  = dev_seq_next,
2287         .stop  = dev_seq_stop,
2288         .show  = sg_proc_seq_show_devstrs,
2289 };
2290
2291 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2292 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2293 static const struct file_operations debug_fops = {
2294         .owner = THIS_MODULE,
2295         .open = sg_proc_open_debug,
2296         .read = seq_read,
2297         .llseek = seq_lseek,
2298         .release = seq_release,
2299 };
2300 static const struct seq_operations debug_seq_ops = {
2301         .start = dev_seq_start,
2302         .next  = dev_seq_next,
2303         .stop  = dev_seq_stop,
2304         .show  = sg_proc_seq_show_debug,
2305 };
2306
2307
2308 struct sg_proc_leaf {
2309         const char * name;
2310         const struct file_operations * fops;
2311 };
2312
2313 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2314         {"allow_dio", &adio_fops},
2315         {"debug", &debug_fops},
2316         {"def_reserved_size", &dressz_fops},
2317         {"device_hdr", &devhdr_fops},
2318         {"devices", &dev_fops},
2319         {"device_strs", &devstrs_fops},
2320         {"version", &version_fops}
2321 };
2322
2323 static int
2324 sg_proc_init(void)
2325 {
2326         int k, mask;
2327         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2328         struct sg_proc_leaf * leaf;
2329
2330         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2331         if (!sg_proc_sgp)
2332                 return 1;
2333         for (k = 0; k < num_leaves; ++k) {
2334                 leaf = &sg_proc_leaf_arr[k];
2335                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2336                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2337         }
2338         return 0;
2339 }
2340
2341 static void
2342 sg_proc_cleanup(void)
2343 {
2344         int k;
2345         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2346
2347         if (!sg_proc_sgp)
2348                 return;
2349         for (k = 0; k < num_leaves; ++k)
2350                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2351         remove_proc_entry(sg_proc_sg_dirname, NULL);
2352 }
2353
2354
2355 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2356 {
2357         seq_printf(s, "%d\n", *((int *)s->private));
2358         return 0;
2359 }
2360
2361 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2362 {
2363         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2364 }
2365
2366 static ssize_t 
2367 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2368                    size_t count, loff_t *off)
2369 {
2370         int num;
2371         char buff[11];
2372
2373         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2374                 return -EACCES;
2375         num = (count < 10) ? count : 10;
2376         if (copy_from_user(buff, buffer, num))
2377                 return -EFAULT;
2378         buff[num] = '\0';
2379         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2380         return count;
2381 }
2382
2383 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2384 {
2385         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2386 }
2387
2388 static ssize_t 
2389 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2390                      size_t count, loff_t *off)
2391 {
2392         int num;
2393         unsigned long k = ULONG_MAX;
2394         char buff[11];
2395
2396         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2397                 return -EACCES;
2398         num = (count < 10) ? count : 10;
2399         if (copy_from_user(buff, buffer, num))
2400                 return -EFAULT;
2401         buff[num] = '\0';
2402         k = simple_strtoul(buff, NULL, 10);
2403         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2404                 sg_big_buff = k;
2405                 return count;
2406         }
2407         return -ERANGE;
2408 }
2409
2410 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2411 {
2412         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2413                    sg_version_date);
2414         return 0;
2415 }
2416
2417 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2418 {
2419         return single_open(file, sg_proc_seq_show_version, NULL);
2420 }
2421
2422 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2423 {
2424         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2425                    "online\n");
2426         return 0;
2427 }
2428
2429 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2430 {
2431         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2432 }
2433
2434 struct sg_proc_deviter {
2435         loff_t  index;
2436         size_t  max;
2437 };
2438
2439 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2440 {
2441         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2442
2443         s->private = it;
2444         if (! it)
2445                 return NULL;
2446
2447         it->index = *pos;
2448         it->max = sg_last_dev();
2449         if (it->index >= it->max)
2450                 return NULL;
2451         return it;
2452 }
2453
2454 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2455 {
2456         struct sg_proc_deviter * it = s->private;
2457
2458         *pos = ++it->index;
2459         return (it->index < it->max) ? it : NULL;
2460 }
2461
2462 static void dev_seq_stop(struct seq_file *s, void *v)
2463 {
2464         kfree(s->private);
2465 }
2466
2467 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2468 {
2469         return seq_open(file, &dev_seq_ops);
2470 }
2471
2472 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2473 {
2474         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2475         Sg_device *sdp;
2476         struct scsi_device *scsidp;
2477         unsigned long iflags;
2478
2479         read_lock_irqsave(&sg_index_lock, iflags);
2480         sdp = it ? sg_lookup_dev(it->index) : NULL;
2481         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2482                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2483                               scsidp->host->host_no, scsidp->channel,
2484                               scsidp->id, scsidp->lun, (int) scsidp->type,
2485                               1,
2486                               (int) scsidp->queue_depth,
2487                               (int) scsidp->device_busy,
2488                               (int) scsi_device_online(scsidp));
2489         else
2490                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2491         read_unlock_irqrestore(&sg_index_lock, iflags);
2492         return 0;
2493 }
2494
2495 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2496 {
2497         return seq_open(file, &devstrs_seq_ops);
2498 }
2499
2500 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2501 {
2502         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2503         Sg_device *sdp;
2504         struct scsi_device *scsidp;
2505         unsigned long iflags;
2506
2507         read_lock_irqsave(&sg_index_lock, iflags);
2508         sdp = it ? sg_lookup_dev(it->index) : NULL;
2509         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2510                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2511                            scsidp->vendor, scsidp->model, scsidp->rev);
2512         else
2513                 seq_printf(s, "<no active device>\n");
2514         read_unlock_irqrestore(&sg_index_lock, iflags);
2515         return 0;
2516 }
2517
2518 /* must be called while holding sg_index_lock */
2519 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2520 {
2521         int k, m, new_interface, blen, usg;
2522         Sg_request *srp;
2523         Sg_fd *fp;
2524         const sg_io_hdr_t *hp;
2525         const char * cp;
2526         unsigned int ms;
2527
2528         k = 0;
2529         list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2530                 k++;
2531                 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2532                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2533                            "(res)sgat=%d low_dma=%d\n", k,
2534                            jiffies_to_msecs(fp->timeout),
2535                            fp->reserve.bufflen,
2536                            (int) fp->reserve.k_use_sg,
2537                            (int) fp->low_dma);
2538                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2539                            (int) fp->cmd_q, (int) fp->force_packid,
2540                            (int) fp->keep_orphan, (int) fp->closed);
2541                 for (m = 0, srp = fp->headrp;
2542                                 srp != NULL;
2543                                 ++m, srp = srp->nextrp) {
2544                         hp = &srp->header;
2545                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2546                         if (srp->res_used) {
2547                                 if (new_interface && 
2548                                     (SG_FLAG_MMAP_IO & hp->flags))
2549                                         cp = "     mmap>> ";
2550                                 else
2551                                         cp = "     rb>> ";
2552                         } else {
2553                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2554                                         cp = "     dio>> ";
2555                                 else
2556                                         cp = "     ";
2557                         }
2558                         seq_printf(s, cp);
2559                         blen = srp->data.bufflen;
2560                         usg = srp->data.k_use_sg;
2561                         seq_printf(s, srp->done ? 
2562                                    ((1 == srp->done) ?  "rcv:" : "fin:")
2563                                    : "act:");
2564                         seq_printf(s, " id=%d blen=%d",
2565                                    srp->header.pack_id, blen);
2566                         if (srp->done)
2567                                 seq_printf(s, " dur=%d", hp->duration);
2568                         else {
2569                                 ms = jiffies_to_msecs(jiffies);
2570                                 seq_printf(s, " t_o/elap=%d/%d",
2571                                         (new_interface ? hp->timeout :
2572                                                   jiffies_to_msecs(fp->timeout)),
2573                                         (ms > hp->duration ? ms - hp->duration : 0));
2574                         }
2575                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2576                                    (int) srp->data.cmd_opcode);
2577                 }
2578                 if (0 == m)
2579                         seq_printf(s, "     No requests active\n");
2580                 read_unlock(&fp->rq_list_lock);
2581         }
2582 }
2583
2584 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2585 {
2586         return seq_open(file, &debug_seq_ops);
2587 }
2588
2589 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2590 {
2591         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2592         Sg_device *sdp;
2593         unsigned long iflags;
2594
2595         if (it && (0 == it->index)) {
2596                 seq_printf(s, "max_active_device=%d(origin 1)\n",
2597                            (int)it->max);
2598                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2599         }
2600
2601         read_lock_irqsave(&sg_index_lock, iflags);
2602         sdp = it ? sg_lookup_dev(it->index) : NULL;
2603         if (sdp && !list_empty(&sdp->sfds)) {
2604                 struct scsi_device *scsidp = sdp->device;
2605
2606                 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2607                 if (sdp->detached)
2608                         seq_printf(s, "detached pending close ");
2609                 else
2610                         seq_printf
2611                             (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2612                              scsidp->host->host_no,
2613                              scsidp->channel, scsidp->id,
2614                              scsidp->lun,
2615                              scsidp->host->hostt->emulated);
2616                 seq_printf(s, " sg_tablesize=%d excl=%d\n",
2617                            sdp->sg_tablesize, sdp->exclude);
2618                 sg_proc_debug_helper(s, sdp);
2619         }
2620         read_unlock_irqrestore(&sg_index_lock, iflags);
2621         return 0;
2622 }
2623
2624 #endif                          /* CONFIG_SCSI_PROC_FS */
2625
2626 module_init(init_sg);
2627 module_exit(exit_sg);