Rationalize fasync return values
[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/fcntl.h>
42 #include <linux/init.h>
43 #include <linux/poll.h>
44 #include <linux/moduleparam.h>
45 #include <linux/cdev.h>
46 #include <linux/idr.h>
47 #include <linux/seq_file.h>
48 #include <linux/blkdev.h>
49 #include <linux/delay.h>
50 #include <linux/blktrace_api.h>
51 #include <linux/smp_lock.h>
52
53 #include "scsi.h"
54 #include <scsi/scsi_dbg.h>
55 #include <scsi/scsi_host.h>
56 #include <scsi/scsi_driver.h>
57 #include <scsi/scsi_ioctl.h>
58 #include <scsi/sg.h>
59
60 #include "scsi_logging.h"
61
62 #ifdef CONFIG_SCSI_PROC_FS
63 #include <linux/proc_fs.h>
64 static char *sg_version_date = "20061027";
65
66 static int sg_proc_init(void);
67 static void sg_proc_cleanup(void);
68 #endif
69
70 #define SG_ALLOW_DIO_DEF 0
71
72 #define SG_MAX_DEVS 32768
73
74 /*
75  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
76  * Then when using 32 bit integers x * m may overflow during the calculation.
77  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
78  * calculates the same, but prevents the overflow when both m and d
79  * are "small" numbers (like HZ and USER_HZ).
80  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
81  * in 32 bits.
82  */
83 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
84
85 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
86
87 int sg_big_buff = SG_DEF_RESERVED_SIZE;
88 /* N.B. This variable is readable and writeable via
89    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
90    of this size (or less if there is not enough memory) will be reserved
91    for use by this file descriptor. [Deprecated usage: this variable is also
92    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
93    the kernel (i.e. it is not a module).] */
94 static int def_reserved_size = -1;      /* picks up init parameter */
95 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
96
97 static int scatter_elem_sz = SG_SCATTER_SZ;
98 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
99
100 #define SG_SECTOR_SZ 512
101 #define SG_SECTOR_MSK (SG_SECTOR_SZ - 1)
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_IDR(sg_index_idr);
107 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
108                                                            file descriptor list for device */
109
110 static struct class_interface sg_interface = {
111         .add_dev        = sg_add,
112         .remove_dev     = sg_remove,
113 };
114
115 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
116         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
117         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
118         unsigned bufflen;       /* Size of (aggregate) data buffer */
119         struct page **pages;
120         int page_order;
121         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
122         unsigned char cmd_opcode; /* first byte of command */
123 } Sg_scatter_hold;
124
125 struct sg_device;               /* forward declarations */
126 struct sg_fd;
127
128 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
129         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
130         struct sg_fd *parentfp; /* NULL -> not in use */
131         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
132         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
133         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
134         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
135         char orphan;            /* 1 -> drop on sight, 0 -> normal */
136         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
137         volatile char done;     /* 0->before bh, 1->before read, 2->read */
138         struct request *rq;
139         struct bio *bio;
140 } Sg_request;
141
142 typedef struct sg_fd {          /* holds the state of a file descriptor */
143         struct sg_fd *nextfp;   /* NULL when last opened fd on this device */
144         struct sg_device *parentdp;     /* owning device */
145         wait_queue_head_t read_wait;    /* queue read until command done */
146         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
147         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
148         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
149         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
150         unsigned save_scat_len; /* original length of trunc. scat. element */
151         Sg_request *headrp;     /* head of request slist, NULL->empty */
152         struct fasync_struct *async_qp; /* used by asynchronous notification */
153         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
154         char low_dma;           /* as in parent but possibly overridden to 1 */
155         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
156         volatile char closed;   /* 1 -> fd closed but request(s) outstanding */
157         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
158         char next_cmd_len;      /* 0 -> automatic (def), >0 -> use on next write() */
159         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
160         char mmap_called;       /* 0 -> mmap() never called on this fd */
161 } Sg_fd;
162
163 typedef struct sg_device { /* holds the state of each scsi generic device */
164         struct scsi_device *device;
165         wait_queue_head_t o_excl_wait;  /* queue open() when O_EXCL in use */
166         int sg_tablesize;       /* adapter's max scatter-gather table size */
167         u32 index;              /* device index number */
168         Sg_fd *headfp;          /* first open fd belonging to this device */
169         volatile char detached; /* 0->attached, 1->detached pending removal */
170         volatile char exclude;  /* opened for exclusive access */
171         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
172         struct gendisk *disk;
173         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
174 } Sg_device;
175
176 static int sg_fasync(int fd, struct file *filp, int mode);
177 /* tasklet or soft irq callback */
178 static void sg_rq_end_io(struct request *rq, int uptodate);
179 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
180 static void sg_finish_rem_req(Sg_request * srp);
181 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
182 static int sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp,
183                          int tablesize);
184 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
185                            Sg_request * srp);
186 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
187                         const char __user *buf, size_t count, int blocking,
188                         int read_only, Sg_request **o_srp);
189 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
190                            unsigned char *cmnd, int timeout, int blocking);
191 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
192 static void sg_remove_scat(Sg_scatter_hold * schp);
193 static void sg_build_reserve(Sg_fd * sfp, int req_size);
194 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
195 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
196 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
197 static int sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
198 static void __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
199 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
200 static Sg_request *sg_add_request(Sg_fd * sfp);
201 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
202 static int sg_res_in_use(Sg_fd * sfp);
203 static Sg_device *sg_get_dev(int dev);
204 #ifdef CONFIG_SCSI_PROC_FS
205 static int sg_last_dev(void);
206 #endif
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 = (struct sg_fd *)filp->private_data;
216         struct request_queue *q = sfp->parentdp->device->request_queue;
217
218         if (sfp->parentdp->device->type == TYPE_SCANNER)
219                 return 0;
220
221         return blk_verify_command(&q->cmd_filter,
222                                   cmd, filp->f_mode & FMODE_WRITE);
223 }
224
225 static int
226 sg_open(struct inode *inode, struct file *filp)
227 {
228         int dev = iminor(inode);
229         int flags = filp->f_flags;
230         struct request_queue *q;
231         Sg_device *sdp;
232         Sg_fd *sfp;
233         int res;
234         int retval;
235
236         lock_kernel();
237         nonseekable_open(inode, filp);
238         SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
239         sdp = sg_get_dev(dev);
240         if ((!sdp) || (!sdp->device)) {
241                 unlock_kernel();
242                 return -ENXIO;
243         }
244         if (sdp->detached) {
245                 unlock_kernel();
246                 return -ENODEV;
247         }
248
249         /* This driver's module count bumped by fops_get in <linux/fs.h> */
250         /* Prevent the device driver from vanishing while we sleep */
251         retval = scsi_device_get(sdp->device);
252         if (retval) {
253                 unlock_kernel();
254                 return retval;
255         }
256
257         if (!((flags & O_NONBLOCK) ||
258               scsi_block_when_processing_errors(sdp->device))) {
259                 retval = -ENXIO;
260                 /* we are in error recovery for this device */
261                 goto error_out;
262         }
263
264         if (flags & O_EXCL) {
265                 if (O_RDONLY == (flags & O_ACCMODE)) {
266                         retval = -EPERM; /* Can't lock it with read only access */
267                         goto error_out;
268                 }
269                 if (sdp->headfp && (flags & O_NONBLOCK)) {
270                         retval = -EBUSY;
271                         goto error_out;
272                 }
273                 res = 0;
274                 __wait_event_interruptible(sdp->o_excl_wait,
275                         ((sdp->headfp || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
276                 if (res) {
277                         retval = res;   /* -ERESTARTSYS because signal hit process */
278                         goto error_out;
279                 }
280         } else if (sdp->exclude) {      /* some other fd has an exclusive lock on dev */
281                 if (flags & O_NONBLOCK) {
282                         retval = -EBUSY;
283                         goto error_out;
284                 }
285                 res = 0;
286                 __wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
287                                            res);
288                 if (res) {
289                         retval = res;   /* -ERESTARTSYS because signal hit process */
290                         goto error_out;
291                 }
292         }
293         if (sdp->detached) {
294                 retval = -ENODEV;
295                 goto error_out;
296         }
297         if (!sdp->headfp) {     /* no existing opens on this device */
298                 sdp->sgdebug = 0;
299                 q = sdp->device->request_queue;
300                 sdp->sg_tablesize = min(q->max_hw_segments,
301                                         q->max_phys_segments);
302         }
303         if ((sfp = sg_add_sfp(sdp, dev)))
304                 filp->private_data = sfp;
305         else {
306                 if (flags & O_EXCL)
307                         sdp->exclude = 0;       /* undo if error */
308                 retval = -ENOMEM;
309                 goto error_out;
310         }
311         unlock_kernel();
312         return 0;
313
314       error_out:
315         scsi_device_put(sdp->device);
316         unlock_kernel();
317         return retval;
318 }
319
320 /* Following function was formerly called 'sg_close' */
321 static int
322 sg_release(struct inode *inode, struct file *filp)
323 {
324         Sg_device *sdp;
325         Sg_fd *sfp;
326
327         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
328                 return -ENXIO;
329         SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
330         if (0 == sg_remove_sfp(sdp, sfp)) {     /* Returns 1 when sdp gone */
331                 if (!sdp->detached) {
332                         scsi_device_put(sdp->device);
333                 }
334                 sdp->exclude = 0;
335                 wake_up_interruptible(&sdp->o_excl_wait);
336         }
337         return 0;
338 }
339
340 static ssize_t
341 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
342 {
343         Sg_device *sdp;
344         Sg_fd *sfp;
345         Sg_request *srp;
346         int req_pack_id = -1;
347         sg_io_hdr_t *hp;
348         struct sg_header *old_hdr = NULL;
349         int retval = 0;
350
351         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
352                 return -ENXIO;
353         SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
354                                    sdp->disk->disk_name, (int) count));
355
356         if (!access_ok(VERIFY_WRITE, buf, count))
357                 return -EFAULT;
358         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
359                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
360                 if (!old_hdr)
361                         return -ENOMEM;
362                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
363                         retval = -EFAULT;
364                         goto free_old_hdr;
365                 }
366                 if (old_hdr->reply_len < 0) {
367                         if (count >= SZ_SG_IO_HDR) {
368                                 sg_io_hdr_t *new_hdr;
369                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
370                                 if (!new_hdr) {
371                                         retval = -ENOMEM;
372                                         goto free_old_hdr;
373                                 }
374                                 retval =__copy_from_user
375                                     (new_hdr, buf, SZ_SG_IO_HDR);
376                                 req_pack_id = new_hdr->pack_id;
377                                 kfree(new_hdr);
378                                 if (retval) {
379                                         retval = -EFAULT;
380                                         goto free_old_hdr;
381                                 }
382                         }
383                 } else
384                         req_pack_id = old_hdr->pack_id;
385         }
386         srp = sg_get_rq_mark(sfp, req_pack_id);
387         if (!srp) {             /* now wait on packet to arrive */
388                 if (sdp->detached) {
389                         retval = -ENODEV;
390                         goto free_old_hdr;
391                 }
392                 if (filp->f_flags & O_NONBLOCK) {
393                         retval = -EAGAIN;
394                         goto free_old_hdr;
395                 }
396                 while (1) {
397                         retval = 0; /* following macro beats race condition */
398                         __wait_event_interruptible(sfp->read_wait,
399                                 (sdp->detached ||
400                                 (srp = sg_get_rq_mark(sfp, req_pack_id))), 
401                                 retval);
402                         if (sdp->detached) {
403                                 retval = -ENODEV;
404                                 goto free_old_hdr;
405                         }
406                         if (0 == retval)
407                                 break;
408
409                         /* -ERESTARTSYS as signal hit process */
410                         goto free_old_hdr;
411                 }
412         }
413         if (srp->header.interface_id != '\0') {
414                 retval = sg_new_read(sfp, buf, count, srp);
415                 goto free_old_hdr;
416         }
417
418         hp = &srp->header;
419         if (old_hdr == NULL) {
420                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
421                 if (! old_hdr) {
422                         retval = -ENOMEM;
423                         goto free_old_hdr;
424                 }
425         }
426         memset(old_hdr, 0, SZ_SG_HEADER);
427         old_hdr->reply_len = (int) hp->timeout;
428         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
429         old_hdr->pack_id = hp->pack_id;
430         old_hdr->twelve_byte =
431             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
432         old_hdr->target_status = hp->masked_status;
433         old_hdr->host_status = hp->host_status;
434         old_hdr->driver_status = hp->driver_status;
435         if ((CHECK_CONDITION & hp->masked_status) ||
436             (DRIVER_SENSE & hp->driver_status))
437                 memcpy(old_hdr->sense_buffer, srp->sense_b,
438                        sizeof (old_hdr->sense_buffer));
439         switch (hp->host_status) {
440         /* This setup of 'result' is for backward compatibility and is best
441            ignored by the user who should use target, host + driver status */
442         case DID_OK:
443         case DID_PASSTHROUGH:
444         case DID_SOFT_ERROR:
445                 old_hdr->result = 0;
446                 break;
447         case DID_NO_CONNECT:
448         case DID_BUS_BUSY:
449         case DID_TIME_OUT:
450                 old_hdr->result = EBUSY;
451                 break;
452         case DID_BAD_TARGET:
453         case DID_ABORT:
454         case DID_PARITY:
455         case DID_RESET:
456         case DID_BAD_INTR:
457                 old_hdr->result = EIO;
458                 break;
459         case DID_ERROR:
460                 old_hdr->result = (srp->sense_b[0] == 0 && 
461                                   hp->masked_status == GOOD) ? 0 : EIO;
462                 break;
463         default:
464                 old_hdr->result = EIO;
465                 break;
466         }
467
468         /* Now copy the result back to the user buffer.  */
469         if (count >= SZ_SG_HEADER) {
470                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
471                         retval = -EFAULT;
472                         goto free_old_hdr;
473                 }
474                 buf += SZ_SG_HEADER;
475                 if (count > old_hdr->reply_len)
476                         count = old_hdr->reply_len;
477                 if (count > SZ_SG_HEADER) {
478                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
479                                 retval = -EFAULT;
480                                 goto free_old_hdr;
481                         }
482                 }
483         } else
484                 count = (old_hdr->result == 0) ? 0 : -EIO;
485         sg_finish_rem_req(srp);
486         retval = count;
487 free_old_hdr:
488         kfree(old_hdr);
489         return retval;
490 }
491
492 static ssize_t
493 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
494 {
495         sg_io_hdr_t *hp = &srp->header;
496         int err = 0;
497         int len;
498
499         if (count < SZ_SG_IO_HDR) {
500                 err = -EINVAL;
501                 goto err_out;
502         }
503         hp->sb_len_wr = 0;
504         if ((hp->mx_sb_len > 0) && hp->sbp) {
505                 if ((CHECK_CONDITION & hp->masked_status) ||
506                     (DRIVER_SENSE & hp->driver_status)) {
507                         int sb_len = SCSI_SENSE_BUFFERSIZE;
508                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
509                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
510                         len = (len > sb_len) ? sb_len : len;
511                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
512                                 err = -EFAULT;
513                                 goto err_out;
514                         }
515                         hp->sb_len_wr = len;
516                 }
517         }
518         if (hp->masked_status || hp->host_status || hp->driver_status)
519                 hp->info |= SG_INFO_CHECK;
520         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
521                 err = -EFAULT;
522                 goto err_out;
523         }
524 err_out:
525         sg_finish_rem_req(srp);
526         return (0 == err) ? count : err;
527 }
528
529 static ssize_t
530 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
531 {
532         int mxsize, cmd_size, k;
533         int input_size, blocking;
534         unsigned char opcode;
535         Sg_device *sdp;
536         Sg_fd *sfp;
537         Sg_request *srp;
538         struct sg_header old_hdr;
539         sg_io_hdr_t *hp;
540         unsigned char cmnd[MAX_COMMAND_SIZE];
541
542         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
543                 return -ENXIO;
544         SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
545                                    sdp->disk->disk_name, (int) count));
546         if (sdp->detached)
547                 return -ENODEV;
548         if (!((filp->f_flags & O_NONBLOCK) ||
549               scsi_block_when_processing_errors(sdp->device)))
550                 return -ENXIO;
551
552         if (!access_ok(VERIFY_READ, buf, count))
553                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
554         if (count < SZ_SG_HEADER)
555                 return -EIO;
556         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
557                 return -EFAULT;
558         blocking = !(filp->f_flags & O_NONBLOCK);
559         if (old_hdr.reply_len < 0)
560                 return sg_new_write(sfp, filp, buf, count, blocking, 0, NULL);
561         if (count < (SZ_SG_HEADER + 6))
562                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
563
564         if (!(srp = sg_add_request(sfp))) {
565                 SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
566                 return -EDOM;
567         }
568         buf += SZ_SG_HEADER;
569         __get_user(opcode, buf);
570         if (sfp->next_cmd_len > 0) {
571                 if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
572                         SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
573                         sfp->next_cmd_len = 0;
574                         sg_remove_request(sfp, srp);
575                         return -EIO;
576                 }
577                 cmd_size = sfp->next_cmd_len;
578                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
579         } else {
580                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
581                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
582                         cmd_size = 12;
583         }
584         SCSI_LOG_TIMEOUT(4, printk(
585                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
586 /* Determine buffer size.  */
587         input_size = count - cmd_size;
588         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
589         mxsize -= SZ_SG_HEADER;
590         input_size -= SZ_SG_HEADER;
591         if (input_size < 0) {
592                 sg_remove_request(sfp, srp);
593                 return -EIO;    /* User did not pass enough bytes for this command. */
594         }
595         hp = &srp->header;
596         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
597         hp->cmd_len = (unsigned char) cmd_size;
598         hp->iovec_count = 0;
599         hp->mx_sb_len = 0;
600         if (input_size > 0)
601                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
602                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
603         else
604                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
605         hp->dxfer_len = mxsize;
606         if (hp->dxfer_direction == SG_DXFER_TO_DEV)
607                 hp->dxferp = (char __user *)buf + cmd_size;
608         else
609                 hp->dxferp = NULL;
610         hp->sbp = NULL;
611         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
612         hp->flags = input_size; /* structure abuse ... */
613         hp->pack_id = old_hdr.pack_id;
614         hp->usr_ptr = NULL;
615         if (__copy_from_user(cmnd, buf, cmd_size))
616                 return -EFAULT;
617         /*
618          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
619          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
620          * is a non-zero input_size, so emit a warning.
621          */
622         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
623                 static char cmd[TASK_COMM_LEN];
624                 if (strcmp(current->comm, cmd) && printk_ratelimit()) {
625                         printk(KERN_WARNING
626                                "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
627                                "guessing data in;\n" KERN_WARNING "   "
628                                "program %s not setting count and/or reply_len properly\n",
629                                old_hdr.reply_len - (int)SZ_SG_HEADER,
630                                input_size, (unsigned int) cmnd[0],
631                                current->comm);
632                         strcpy(cmd, current->comm);
633                 }
634         }
635         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
636         return (k < 0) ? k : count;
637 }
638
639 static ssize_t
640 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
641                  size_t count, int blocking, int read_only,
642                  Sg_request **o_srp)
643 {
644         int k;
645         Sg_request *srp;
646         sg_io_hdr_t *hp;
647         unsigned char cmnd[MAX_COMMAND_SIZE];
648         int timeout;
649         unsigned long ul_timeout;
650
651         if (count < SZ_SG_IO_HDR)
652                 return -EINVAL;
653         if (!access_ok(VERIFY_READ, buf, count))
654                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
655
656         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
657         if (!(srp = sg_add_request(sfp))) {
658                 SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
659                 return -EDOM;
660         }
661         hp = &srp->header;
662         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
663                 sg_remove_request(sfp, srp);
664                 return -EFAULT;
665         }
666         if (hp->interface_id != 'S') {
667                 sg_remove_request(sfp, srp);
668                 return -ENOSYS;
669         }
670         if (hp->flags & SG_FLAG_MMAP_IO) {
671                 if (hp->dxfer_len > sfp->reserve.bufflen) {
672                         sg_remove_request(sfp, srp);
673                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
674                 }
675                 if (hp->flags & SG_FLAG_DIRECT_IO) {
676                         sg_remove_request(sfp, srp);
677                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
678                 }
679                 if (sg_res_in_use(sfp)) {
680                         sg_remove_request(sfp, srp);
681                         return -EBUSY;  /* reserve buffer already being used */
682                 }
683         }
684         ul_timeout = msecs_to_jiffies(srp->header.timeout);
685         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
686         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
687                 sg_remove_request(sfp, srp);
688                 return -EMSGSIZE;
689         }
690         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
691                 sg_remove_request(sfp, srp);
692                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
693         }
694         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
695                 sg_remove_request(sfp, srp);
696                 return -EFAULT;
697         }
698         if (read_only && sg_allow_access(file, cmnd)) {
699                 sg_remove_request(sfp, srp);
700                 return -EPERM;
701         }
702         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
703         if (k < 0)
704                 return k;
705         if (o_srp)
706                 *o_srp = srp;
707         return count;
708 }
709
710 static int
711 sg_common_write(Sg_fd * sfp, Sg_request * srp,
712                 unsigned char *cmnd, int timeout, int blocking)
713 {
714         int k, data_dir;
715         Sg_device *sdp = sfp->parentdp;
716         sg_io_hdr_t *hp = &srp->header;
717
718         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
719         hp->status = 0;
720         hp->masked_status = 0;
721         hp->msg_status = 0;
722         hp->info = 0;
723         hp->host_status = 0;
724         hp->driver_status = 0;
725         hp->resid = 0;
726         SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
727                           (int) cmnd[0], (int) hp->cmd_len));
728
729         k = sg_start_req(srp, cmnd);
730         if (k) {
731                 SCSI_LOG_TIMEOUT(1, printk("sg_common_write: start_req err=%d\n", k));
732                 sg_finish_rem_req(srp);
733                 return k;       /* probably out of space --> ENOMEM */
734         }
735         if (sdp->detached) {
736                 sg_finish_rem_req(srp);
737                 return -ENODEV;
738         }
739
740         switch (hp->dxfer_direction) {
741         case SG_DXFER_TO_FROM_DEV:
742         case SG_DXFER_FROM_DEV:
743                 data_dir = DMA_FROM_DEVICE;
744                 break;
745         case SG_DXFER_TO_DEV:
746                 data_dir = DMA_TO_DEVICE;
747                 break;
748         case SG_DXFER_UNKNOWN:
749                 data_dir = DMA_BIDIRECTIONAL;
750                 break;
751         default:
752                 data_dir = DMA_NONE;
753                 break;
754         }
755         hp->duration = jiffies_to_msecs(jiffies);
756
757         srp->rq->timeout = timeout;
758         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
759                               srp->rq, 1, sg_rq_end_io);
760         return 0;
761 }
762
763 static int
764 sg_srp_done(Sg_request *srp, Sg_fd *sfp)
765 {
766         unsigned long iflags;
767         int done;
768
769         read_lock_irqsave(&sfp->rq_list_lock, iflags);
770         done = srp->done;
771         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
772         return done;
773 }
774
775 static int
776 sg_ioctl(struct inode *inode, struct file *filp,
777          unsigned int cmd_in, unsigned long arg)
778 {
779         void __user *p = (void __user *)arg;
780         int __user *ip = p;
781         int result, val, read_only;
782         Sg_device *sdp;
783         Sg_fd *sfp;
784         Sg_request *srp;
785         unsigned long iflags;
786
787         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
788                 return -ENXIO;
789
790         SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
791                                    sdp->disk->disk_name, (int) cmd_in));
792         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
793
794         switch (cmd_in) {
795         case SG_IO:
796                 {
797                         int blocking = 1;       /* ignore O_NONBLOCK flag */
798
799                         if (sdp->detached)
800                                 return -ENODEV;
801                         if (!scsi_block_when_processing_errors(sdp->device))
802                                 return -ENXIO;
803                         if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
804                                 return -EFAULT;
805                         result =
806                             sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
807                                          blocking, read_only, &srp);
808                         if (result < 0)
809                                 return result;
810                         srp->sg_io_owned = 1;
811                         while (1) {
812                                 result = 0;     /* following macro to beat race condition */
813                                 __wait_event_interruptible(sfp->read_wait,
814                                         (sdp->detached || sfp->closed || sg_srp_done(srp, sfp)),
815                                                            result);
816                                 if (sdp->detached)
817                                         return -ENODEV;
818                                 if (sfp->closed)
819                                         return 0;       /* request packet dropped already */
820                                 if (0 == result)
821                                         break;
822                                 srp->orphan = 1;
823                                 return result;  /* -ERESTARTSYS because signal hit process */
824                         }
825                         write_lock_irqsave(&sfp->rq_list_lock, iflags);
826                         srp->done = 2;
827                         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
828                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
829                         return (result < 0) ? result : 0;
830                 }
831         case SG_SET_TIMEOUT:
832                 result = get_user(val, ip);
833                 if (result)
834                         return result;
835                 if (val < 0)
836                         return -EIO;
837                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
838                     val = MULDIV (INT_MAX, USER_HZ, HZ);
839                 sfp->timeout_user = val;
840                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
841
842                 return 0;
843         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
844                                 /* strange ..., for backward compatibility */
845                 return sfp->timeout_user;
846         case SG_SET_FORCE_LOW_DMA:
847                 result = get_user(val, ip);
848                 if (result)
849                         return result;
850                 if (val) {
851                         sfp->low_dma = 1;
852                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
853                                 val = (int) sfp->reserve.bufflen;
854                                 sg_remove_scat(&sfp->reserve);
855                                 sg_build_reserve(sfp, val);
856                         }
857                 } else {
858                         if (sdp->detached)
859                                 return -ENODEV;
860                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
861                 }
862                 return 0;
863         case SG_GET_LOW_DMA:
864                 return put_user((int) sfp->low_dma, ip);
865         case SG_GET_SCSI_ID:
866                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
867                         return -EFAULT;
868                 else {
869                         sg_scsi_id_t __user *sg_idp = p;
870
871                         if (sdp->detached)
872                                 return -ENODEV;
873                         __put_user((int) sdp->device->host->host_no,
874                                    &sg_idp->host_no);
875                         __put_user((int) sdp->device->channel,
876                                    &sg_idp->channel);
877                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
878                         __put_user((int) sdp->device->lun, &sg_idp->lun);
879                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
880                         __put_user((short) sdp->device->host->cmd_per_lun,
881                                    &sg_idp->h_cmd_per_lun);
882                         __put_user((short) sdp->device->queue_depth,
883                                    &sg_idp->d_queue_depth);
884                         __put_user(0, &sg_idp->unused[0]);
885                         __put_user(0, &sg_idp->unused[1]);
886                         return 0;
887                 }
888         case SG_SET_FORCE_PACK_ID:
889                 result = get_user(val, ip);
890                 if (result)
891                         return result;
892                 sfp->force_packid = val ? 1 : 0;
893                 return 0;
894         case SG_GET_PACK_ID:
895                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
896                         return -EFAULT;
897                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
898                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
899                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
900                                 read_unlock_irqrestore(&sfp->rq_list_lock,
901                                                        iflags);
902                                 __put_user(srp->header.pack_id, ip);
903                                 return 0;
904                         }
905                 }
906                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
907                 __put_user(-1, ip);
908                 return 0;
909         case SG_GET_NUM_WAITING:
910                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
911                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
912                         if ((1 == srp->done) && (!srp->sg_io_owned))
913                                 ++val;
914                 }
915                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
916                 return put_user(val, ip);
917         case SG_GET_SG_TABLESIZE:
918                 return put_user(sdp->sg_tablesize, ip);
919         case SG_SET_RESERVED_SIZE:
920                 result = get_user(val, ip);
921                 if (result)
922                         return result;
923                 if (val < 0)
924                         return -EINVAL;
925                 val = min_t(int, val,
926                                 sdp->device->request_queue->max_sectors * 512);
927                 if (val != sfp->reserve.bufflen) {
928                         if (sg_res_in_use(sfp) || sfp->mmap_called)
929                                 return -EBUSY;
930                         sg_remove_scat(&sfp->reserve);
931                         sg_build_reserve(sfp, val);
932                 }
933                 return 0;
934         case SG_GET_RESERVED_SIZE:
935                 val = min_t(int, sfp->reserve.bufflen,
936                                 sdp->device->request_queue->max_sectors * 512);
937                 return put_user(val, ip);
938         case SG_SET_COMMAND_Q:
939                 result = get_user(val, ip);
940                 if (result)
941                         return result;
942                 sfp->cmd_q = val ? 1 : 0;
943                 return 0;
944         case SG_GET_COMMAND_Q:
945                 return put_user((int) sfp->cmd_q, ip);
946         case SG_SET_KEEP_ORPHAN:
947                 result = get_user(val, ip);
948                 if (result)
949                         return result;
950                 sfp->keep_orphan = val;
951                 return 0;
952         case SG_GET_KEEP_ORPHAN:
953                 return put_user((int) sfp->keep_orphan, ip);
954         case SG_NEXT_CMD_LEN:
955                 result = get_user(val, ip);
956                 if (result)
957                         return result;
958                 sfp->next_cmd_len = (val > 0) ? val : 0;
959                 return 0;
960         case SG_GET_VERSION_NUM:
961                 return put_user(sg_version_num, ip);
962         case SG_GET_ACCESS_COUNT:
963                 /* faked - we don't have a real access count anymore */
964                 val = (sdp->device ? 1 : 0);
965                 return put_user(val, ip);
966         case SG_GET_REQUEST_TABLE:
967                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
968                         return -EFAULT;
969                 else {
970                         sg_req_info_t *rinfo;
971                         unsigned int ms;
972
973                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
974                                                                 GFP_KERNEL);
975                         if (!rinfo)
976                                 return -ENOMEM;
977                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
978                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
979                              ++val, srp = srp ? srp->nextrp : srp) {
980                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
981                                 if (srp) {
982                                         rinfo[val].req_state = srp->done + 1;
983                                         rinfo[val].problem =
984                                             srp->header.masked_status & 
985                                             srp->header.host_status & 
986                                             srp->header.driver_status;
987                                         if (srp->done)
988                                                 rinfo[val].duration =
989                                                         srp->header.duration;
990                                         else {
991                                                 ms = jiffies_to_msecs(jiffies);
992                                                 rinfo[val].duration =
993                                                     (ms > srp->header.duration) ?
994                                                     (ms - srp->header.duration) : 0;
995                                         }
996                                         rinfo[val].orphan = srp->orphan;
997                                         rinfo[val].sg_io_owned =
998                                                         srp->sg_io_owned;
999                                         rinfo[val].pack_id =
1000                                                         srp->header.pack_id;
1001                                         rinfo[val].usr_ptr =
1002                                                         srp->header.usr_ptr;
1003                                 }
1004                         }
1005                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1006                         result = __copy_to_user(p, rinfo, 
1007                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1008                         result = result ? -EFAULT : 0;
1009                         kfree(rinfo);
1010                         return result;
1011                 }
1012         case SG_EMULATED_HOST:
1013                 if (sdp->detached)
1014                         return -ENODEV;
1015                 return put_user(sdp->device->host->hostt->emulated, ip);
1016         case SG_SCSI_RESET:
1017                 if (sdp->detached)
1018                         return -ENODEV;
1019                 if (filp->f_flags & O_NONBLOCK) {
1020                         if (scsi_host_in_recovery(sdp->device->host))
1021                                 return -EBUSY;
1022                 } else if (!scsi_block_when_processing_errors(sdp->device))
1023                         return -EBUSY;
1024                 result = get_user(val, ip);
1025                 if (result)
1026                         return result;
1027                 if (SG_SCSI_RESET_NOTHING == val)
1028                         return 0;
1029                 switch (val) {
1030                 case SG_SCSI_RESET_DEVICE:
1031                         val = SCSI_TRY_RESET_DEVICE;
1032                         break;
1033                 case SG_SCSI_RESET_TARGET:
1034                         val = SCSI_TRY_RESET_TARGET;
1035                         break;
1036                 case SG_SCSI_RESET_BUS:
1037                         val = SCSI_TRY_RESET_BUS;
1038                         break;
1039                 case SG_SCSI_RESET_HOST:
1040                         val = SCSI_TRY_RESET_HOST;
1041                         break;
1042                 default:
1043                         return -EINVAL;
1044                 }
1045                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1046                         return -EACCES;
1047                 return (scsi_reset_provider(sdp->device, val) ==
1048                         SUCCESS) ? 0 : -EIO;
1049         case SCSI_IOCTL_SEND_COMMAND:
1050                 if (sdp->detached)
1051                         return -ENODEV;
1052                 if (read_only) {
1053                         unsigned char opcode = WRITE_6;
1054                         Scsi_Ioctl_Command __user *siocp = p;
1055
1056                         if (copy_from_user(&opcode, siocp->data, 1))
1057                                 return -EFAULT;
1058                         if (sg_allow_access(filp, &opcode))
1059                                 return -EPERM;
1060                 }
1061                 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1062         case SG_SET_DEBUG:
1063                 result = get_user(val, ip);
1064                 if (result)
1065                         return result;
1066                 sdp->sgdebug = (char) val;
1067                 return 0;
1068         case SCSI_IOCTL_GET_IDLUN:
1069         case SCSI_IOCTL_GET_BUS_NUMBER:
1070         case SCSI_IOCTL_PROBE_HOST:
1071         case SG_GET_TRANSFORM:
1072                 if (sdp->detached)
1073                         return -ENODEV;
1074                 return scsi_ioctl(sdp->device, cmd_in, p);
1075         case BLKSECTGET:
1076                 return put_user(sdp->device->request_queue->max_sectors * 512,
1077                                 ip);
1078         case BLKTRACESETUP:
1079                 return blk_trace_setup(sdp->device->request_queue,
1080                                        sdp->disk->disk_name,
1081                                        MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1082                                        (char *)arg);
1083         case BLKTRACESTART:
1084                 return blk_trace_startstop(sdp->device->request_queue, 1);
1085         case BLKTRACESTOP:
1086                 return blk_trace_startstop(sdp->device->request_queue, 0);
1087         case BLKTRACETEARDOWN:
1088                 return blk_trace_remove(sdp->device->request_queue);
1089         default:
1090                 if (read_only)
1091                         return -EPERM;  /* don't know so take safe approach */
1092                 return scsi_ioctl(sdp->device, cmd_in, p);
1093         }
1094 }
1095
1096 #ifdef CONFIG_COMPAT
1097 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1098 {
1099         Sg_device *sdp;
1100         Sg_fd *sfp;
1101         struct scsi_device *sdev;
1102
1103         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1104                 return -ENXIO;
1105
1106         sdev = sdp->device;
1107         if (sdev->host->hostt->compat_ioctl) { 
1108                 int ret;
1109
1110                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1111
1112                 return ret;
1113         }
1114         
1115         return -ENOIOCTLCMD;
1116 }
1117 #endif
1118
1119 static unsigned int
1120 sg_poll(struct file *filp, poll_table * wait)
1121 {
1122         unsigned int res = 0;
1123         Sg_device *sdp;
1124         Sg_fd *sfp;
1125         Sg_request *srp;
1126         int count = 0;
1127         unsigned long iflags;
1128
1129         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1130             || sfp->closed)
1131                 return POLLERR;
1132         poll_wait(filp, &sfp->read_wait, wait);
1133         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1134         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1135                 /* if any read waiting, flag it */
1136                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1137                         res = POLLIN | POLLRDNORM;
1138                 ++count;
1139         }
1140         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1141
1142         if (sdp->detached)
1143                 res |= POLLHUP;
1144         else if (!sfp->cmd_q) {
1145                 if (0 == count)
1146                         res |= POLLOUT | POLLWRNORM;
1147         } else if (count < SG_MAX_QUEUE)
1148                 res |= POLLOUT | POLLWRNORM;
1149         SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1150                                    sdp->disk->disk_name, (int) res));
1151         return res;
1152 }
1153
1154 static int
1155 sg_fasync(int fd, struct file *filp, int mode)
1156 {
1157         Sg_device *sdp;
1158         Sg_fd *sfp;
1159
1160         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1161                 return -ENXIO;
1162         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1163                                    sdp->disk->disk_name, mode));
1164
1165         return fasync_helper(fd, filp, mode, &sfp->async_qp);
1166 }
1167
1168 static int
1169 sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1170 {
1171         Sg_fd *sfp;
1172         unsigned long offset, len, sa;
1173         Sg_scatter_hold *rsv_schp;
1174         int k, length;
1175
1176         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1177                 return VM_FAULT_SIGBUS;
1178         rsv_schp = &sfp->reserve;
1179         offset = vmf->pgoff << PAGE_SHIFT;
1180         if (offset >= rsv_schp->bufflen)
1181                 return VM_FAULT_SIGBUS;
1182         SCSI_LOG_TIMEOUT(3, printk("sg_vma_fault: offset=%lu, scatg=%d\n",
1183                                    offset, rsv_schp->k_use_sg));
1184         sa = vma->vm_start;
1185         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1186         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1187                 len = vma->vm_end - sa;
1188                 len = (len < length) ? len : length;
1189                 if (offset < len) {
1190                         struct page *page = nth_page(rsv_schp->pages[k],
1191                                                      offset >> PAGE_SHIFT);
1192                         get_page(page); /* increment page count */
1193                         vmf->page = page;
1194                         return 0; /* success */
1195                 }
1196                 sa += len;
1197                 offset -= len;
1198         }
1199
1200         return VM_FAULT_SIGBUS;
1201 }
1202
1203 static struct vm_operations_struct sg_mmap_vm_ops = {
1204         .fault = sg_vma_fault,
1205 };
1206
1207 static int
1208 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1209 {
1210         Sg_fd *sfp;
1211         unsigned long req_sz, len, sa;
1212         Sg_scatter_hold *rsv_schp;
1213         int k, length;
1214
1215         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1216                 return -ENXIO;
1217         req_sz = vma->vm_end - vma->vm_start;
1218         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1219                                    (void *) vma->vm_start, (int) req_sz));
1220         if (vma->vm_pgoff)
1221                 return -EINVAL; /* want no offset */
1222         rsv_schp = &sfp->reserve;
1223         if (req_sz > rsv_schp->bufflen)
1224                 return -ENOMEM; /* cannot map more than reserved buffer */
1225
1226         sa = vma->vm_start;
1227         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1228         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1229                 len = vma->vm_end - sa;
1230                 len = (len < length) ? len : length;
1231                 sa += len;
1232         }
1233
1234         sfp->mmap_called = 1;
1235         vma->vm_flags |= VM_RESERVED;
1236         vma->vm_private_data = sfp;
1237         vma->vm_ops = &sg_mmap_vm_ops;
1238         return 0;
1239 }
1240
1241 /*
1242  * This function is a "bottom half" handler that is called by the mid
1243  * level when a command is completed (or has failed).
1244  */
1245 static void sg_rq_end_io(struct request *rq, int uptodate)
1246 {
1247         struct sg_request *srp = rq->end_io_data;
1248         Sg_device *sdp = NULL;
1249         Sg_fd *sfp;
1250         unsigned long iflags;
1251         unsigned int ms;
1252         char *sense;
1253         int result, resid;
1254
1255         if (NULL == srp) {
1256                 printk(KERN_ERR "sg_cmd_done: NULL request\n");
1257                 return;
1258         }
1259         sfp = srp->parentfp;
1260         if (sfp)
1261                 sdp = sfp->parentdp;
1262         if ((NULL == sdp) || sdp->detached) {
1263                 printk(KERN_INFO "sg_cmd_done: device detached\n");
1264                 return;
1265         }
1266
1267         sense = rq->sense;
1268         result = rq->errors;
1269         resid = rq->data_len;
1270
1271         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1272                 sdp->disk->disk_name, srp->header.pack_id, result));
1273         srp->header.resid = resid;
1274         ms = jiffies_to_msecs(jiffies);
1275         srp->header.duration = (ms > srp->header.duration) ?
1276                                 (ms - srp->header.duration) : 0;
1277         if (0 != result) {
1278                 struct scsi_sense_hdr sshdr;
1279
1280                 srp->header.status = 0xff & result;
1281                 srp->header.masked_status = status_byte(result);
1282                 srp->header.msg_status = msg_byte(result);
1283                 srp->header.host_status = host_byte(result);
1284                 srp->header.driver_status = driver_byte(result);
1285                 if ((sdp->sgdebug > 0) &&
1286                     ((CHECK_CONDITION == srp->header.masked_status) ||
1287                      (COMMAND_TERMINATED == srp->header.masked_status)))
1288                         __scsi_print_sense("sg_cmd_done", sense,
1289                                            SCSI_SENSE_BUFFERSIZE);
1290
1291                 /* Following if statement is a patch supplied by Eric Youngdale */
1292                 if (driver_byte(result) != 0
1293                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1294                     && !scsi_sense_is_deferred(&sshdr)
1295                     && sshdr.sense_key == UNIT_ATTENTION
1296                     && sdp->device->removable) {
1297                         /* Detected possible disc change. Set the bit - this */
1298                         /* may be used if there are filesystems using this device */
1299                         sdp->device->changed = 1;
1300                 }
1301         }
1302         /* Rely on write phase to clean out srp status values, so no "else" */
1303
1304         if (sfp->closed) {      /* whoops this fd already released, cleanup */
1305                 SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
1306                 sg_finish_rem_req(srp);
1307                 srp = NULL;
1308                 if (NULL == sfp->headrp) {
1309                         SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, final cleanup\n"));
1310                         if (0 == sg_remove_sfp(sdp, sfp)) {     /* device still present */
1311                                 scsi_device_put(sdp->device);
1312                         }
1313                         sfp = NULL;
1314                 }
1315         } else if (srp && srp->orphan) {
1316                 if (sfp->keep_orphan)
1317                         srp->sg_io_owned = 0;
1318                 else {
1319                         sg_finish_rem_req(srp);
1320                         srp = NULL;
1321                 }
1322         }
1323         if (sfp && srp) {
1324                 /* Now wake up any sg_read() that is waiting for this packet. */
1325                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1326                 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1327                 srp->done = 1;
1328                 wake_up_interruptible(&sfp->read_wait);
1329                 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1330         }
1331 }
1332
1333 static struct file_operations sg_fops = {
1334         .owner = THIS_MODULE,
1335         .read = sg_read,
1336         .write = sg_write,
1337         .poll = sg_poll,
1338         .ioctl = sg_ioctl,
1339 #ifdef CONFIG_COMPAT
1340         .compat_ioctl = sg_compat_ioctl,
1341 #endif
1342         .open = sg_open,
1343         .mmap = sg_mmap,
1344         .release = sg_release,
1345         .fasync = sg_fasync,
1346 };
1347
1348 static struct class *sg_sysfs_class;
1349
1350 static int sg_sysfs_valid = 0;
1351
1352 static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1353 {
1354         struct request_queue *q = scsidp->request_queue;
1355         Sg_device *sdp;
1356         unsigned long iflags;
1357         int error;
1358         u32 k;
1359
1360         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1361         if (!sdp) {
1362                 printk(KERN_WARNING "kmalloc Sg_device failure\n");
1363                 return ERR_PTR(-ENOMEM);
1364         }
1365         error = -ENOMEM;
1366         if (!idr_pre_get(&sg_index_idr, GFP_KERNEL)) {
1367                 printk(KERN_WARNING "idr expansion Sg_device failure\n");
1368                 goto out;
1369         }
1370
1371         write_lock_irqsave(&sg_index_lock, iflags);
1372         error = idr_get_new(&sg_index_idr, sdp, &k);
1373         write_unlock_irqrestore(&sg_index_lock, iflags);
1374
1375         if (error) {
1376                 printk(KERN_WARNING "idr allocation Sg_device failure: %d\n",
1377                        error);
1378                 goto out;
1379         }
1380
1381         if (unlikely(k >= SG_MAX_DEVS))
1382                 goto overflow;
1383
1384         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1385         sprintf(disk->disk_name, "sg%d", k);
1386         disk->first_minor = k;
1387         sdp->disk = disk;
1388         sdp->device = scsidp;
1389         init_waitqueue_head(&sdp->o_excl_wait);
1390         sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments);
1391         sdp->index = k;
1392
1393         error = 0;
1394  out:
1395         if (error) {
1396                 kfree(sdp);
1397                 return ERR_PTR(error);
1398         }
1399         return sdp;
1400
1401  overflow:
1402         sdev_printk(KERN_WARNING, scsidp,
1403                     "Unable to attach sg device type=%d, minor "
1404                     "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1405         error = -ENODEV;
1406         goto out;
1407 }
1408
1409 static int
1410 sg_add(struct device *cl_dev, struct class_interface *cl_intf)
1411 {
1412         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1413         struct gendisk *disk;
1414         Sg_device *sdp = NULL;
1415         struct cdev * cdev = NULL;
1416         int error;
1417         unsigned long iflags;
1418
1419         disk = alloc_disk(1);
1420         if (!disk) {
1421                 printk(KERN_WARNING "alloc_disk failed\n");
1422                 return -ENOMEM;
1423         }
1424         disk->major = SCSI_GENERIC_MAJOR;
1425
1426         error = -ENOMEM;
1427         cdev = cdev_alloc();
1428         if (!cdev) {
1429                 printk(KERN_WARNING "cdev_alloc failed\n");
1430                 goto out;
1431         }
1432         cdev->owner = THIS_MODULE;
1433         cdev->ops = &sg_fops;
1434
1435         sdp = sg_alloc(disk, scsidp);
1436         if (IS_ERR(sdp)) {
1437                 printk(KERN_WARNING "sg_alloc failed\n");
1438                 error = PTR_ERR(sdp);
1439                 goto out;
1440         }
1441
1442         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1443         if (error)
1444                 goto cdev_add_err;
1445
1446         sdp->cdev = cdev;
1447         if (sg_sysfs_valid) {
1448                 struct device *sg_class_member;
1449
1450                 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1451                                                 MKDEV(SCSI_GENERIC_MAJOR,
1452                                                       sdp->index),
1453                                                 sdp, "%s", disk->disk_name);
1454                 if (IS_ERR(sg_class_member)) {
1455                         printk(KERN_ERR "sg_add: "
1456                                "device_create failed\n");
1457                         error = PTR_ERR(sg_class_member);
1458                         goto cdev_add_err;
1459                 }
1460                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1461                                           &sg_class_member->kobj, "generic");
1462                 if (error)
1463                         printk(KERN_ERR "sg_add: unable to make symlink "
1464                                         "'generic' back to sg%d\n", sdp->index);
1465         } else
1466                 printk(KERN_WARNING "sg_add: sg_sys Invalid\n");
1467
1468         sdev_printk(KERN_NOTICE, scsidp,
1469                     "Attached scsi generic sg%d type %d\n", sdp->index,
1470                     scsidp->type);
1471
1472         dev_set_drvdata(cl_dev, sdp);
1473
1474         return 0;
1475
1476 cdev_add_err:
1477         write_lock_irqsave(&sg_index_lock, iflags);
1478         idr_remove(&sg_index_idr, sdp->index);
1479         write_unlock_irqrestore(&sg_index_lock, iflags);
1480         kfree(sdp);
1481
1482 out:
1483         put_disk(disk);
1484         if (cdev)
1485                 cdev_del(cdev);
1486         return error;
1487 }
1488
1489 static void
1490 sg_remove(struct device *cl_dev, struct class_interface *cl_intf)
1491 {
1492         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1493         Sg_device *sdp = dev_get_drvdata(cl_dev);
1494         unsigned long iflags;
1495         Sg_fd *sfp;
1496         Sg_fd *tsfp;
1497         Sg_request *srp;
1498         Sg_request *tsrp;
1499         int delay;
1500
1501         if (!sdp)
1502                 return;
1503
1504         delay = 0;
1505         write_lock_irqsave(&sg_index_lock, iflags);
1506         if (sdp->headfp) {
1507                 sdp->detached = 1;
1508                 for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1509                         tsfp = sfp->nextfp;
1510                         for (srp = sfp->headrp; srp; srp = tsrp) {
1511                                 tsrp = srp->nextrp;
1512                                 if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
1513                                         sg_finish_rem_req(srp);
1514                         }
1515                         if (sfp->closed) {
1516                                 scsi_device_put(sdp->device);
1517                                 __sg_remove_sfp(sdp, sfp);
1518                         } else {
1519                                 delay = 1;
1520                                 wake_up_interruptible(&sfp->read_wait);
1521                                 kill_fasync(&sfp->async_qp, SIGPOLL,
1522                                             POLL_HUP);
1523                         }
1524                 }
1525                 SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d, dirty\n", sdp->index));
1526                 if (NULL == sdp->headfp) {
1527                         idr_remove(&sg_index_idr, sdp->index);
1528                 }
1529         } else {        /* nothing active, simple case */
1530                 SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d\n", sdp->index));
1531                 idr_remove(&sg_index_idr, sdp->index);
1532         }
1533         write_unlock_irqrestore(&sg_index_lock, iflags);
1534
1535         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1536         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1537         cdev_del(sdp->cdev);
1538         sdp->cdev = NULL;
1539         put_disk(sdp->disk);
1540         sdp->disk = NULL;
1541         if (NULL == sdp->headfp)
1542                 kfree(sdp);
1543
1544         if (delay)
1545                 msleep(10);     /* dirty detach so delay device destruction */
1546 }
1547
1548 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1549 module_param_named(def_reserved_size, def_reserved_size, int,
1550                    S_IRUGO | S_IWUSR);
1551 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1552
1553 MODULE_AUTHOR("Douglas Gilbert");
1554 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1555 MODULE_LICENSE("GPL");
1556 MODULE_VERSION(SG_VERSION_STR);
1557 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1558
1559 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1560                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1561 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1562 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1563
1564 static int __init
1565 init_sg(void)
1566 {
1567         int rc;
1568
1569         if (scatter_elem_sz < PAGE_SIZE) {
1570                 scatter_elem_sz = PAGE_SIZE;
1571                 scatter_elem_sz_prev = scatter_elem_sz;
1572         }
1573         if (def_reserved_size >= 0)
1574                 sg_big_buff = def_reserved_size;
1575         else
1576                 def_reserved_size = sg_big_buff;
1577
1578         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), 
1579                                     SG_MAX_DEVS, "sg");
1580         if (rc)
1581                 return rc;
1582         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1583         if ( IS_ERR(sg_sysfs_class) ) {
1584                 rc = PTR_ERR(sg_sysfs_class);
1585                 goto err_out;
1586         }
1587         sg_sysfs_valid = 1;
1588         rc = scsi_register_interface(&sg_interface);
1589         if (0 == rc) {
1590 #ifdef CONFIG_SCSI_PROC_FS
1591                 sg_proc_init();
1592 #endif                          /* CONFIG_SCSI_PROC_FS */
1593                 return 0;
1594         }
1595         class_destroy(sg_sysfs_class);
1596 err_out:
1597         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1598         return rc;
1599 }
1600
1601 static void __exit
1602 exit_sg(void)
1603 {
1604 #ifdef CONFIG_SCSI_PROC_FS
1605         sg_proc_cleanup();
1606 #endif                          /* CONFIG_SCSI_PROC_FS */
1607         scsi_unregister_interface(&sg_interface);
1608         class_destroy(sg_sysfs_class);
1609         sg_sysfs_valid = 0;
1610         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1611                                  SG_MAX_DEVS);
1612         idr_destroy(&sg_index_idr);
1613 }
1614
1615 static int sg_start_req(Sg_request *srp, unsigned char *cmd)
1616 {
1617         int res;
1618         struct request *rq;
1619         Sg_fd *sfp = srp->parentfp;
1620         sg_io_hdr_t *hp = &srp->header;
1621         int dxfer_len = (int) hp->dxfer_len;
1622         int dxfer_dir = hp->dxfer_direction;
1623         unsigned int iov_count = hp->iovec_count;
1624         Sg_scatter_hold *req_schp = &srp->data;
1625         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1626         struct request_queue *q = sfp->parentdp->device->request_queue;
1627         struct rq_map_data *md, map_data;
1628         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1629
1630         SCSI_LOG_TIMEOUT(4, printk(KERN_INFO "sg_start_req: dxfer_len=%d\n",
1631                                    dxfer_len));
1632
1633         rq = blk_get_request(q, rw, GFP_ATOMIC);
1634         if (!rq)
1635                 return -ENOMEM;
1636
1637         memcpy(rq->cmd, cmd, hp->cmd_len);
1638
1639         rq->cmd_len = hp->cmd_len;
1640         rq->cmd_type = REQ_TYPE_BLOCK_PC;
1641
1642         srp->rq = rq;
1643         rq->end_io_data = srp;
1644         rq->sense = srp->sense_b;
1645         rq->retries = SG_DEFAULT_RETRIES;
1646
1647         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1648                 return 0;
1649
1650         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1651             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1652             !sfp->parentdp->device->host->unchecked_isa_dma &&
1653             blk_rq_aligned(q, hp->dxferp, dxfer_len))
1654                 md = NULL;
1655         else
1656                 md = &map_data;
1657
1658         if (md) {
1659                 if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen)
1660                         sg_link_reserve(sfp, srp, dxfer_len);
1661                 else {
1662                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1663                         if (res)
1664                                 return res;
1665                 }
1666
1667                 md->pages = req_schp->pages;
1668                 md->page_order = req_schp->page_order;
1669                 md->nr_entries = req_schp->k_use_sg;
1670                 md->offset = 0;
1671                 md->null_mapped = hp->dxferp ? 0 : 1;
1672         }
1673
1674         if (iov_count)
1675                 res = blk_rq_map_user_iov(q, rq, md, hp->dxferp, iov_count,
1676                                           hp->dxfer_len, GFP_ATOMIC);
1677         else
1678                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1679                                       hp->dxfer_len, GFP_ATOMIC);
1680
1681         if (!res) {
1682                 srp->bio = rq->bio;
1683
1684                 if (!md) {
1685                         req_schp->dio_in_use = 1;
1686                         hp->info |= SG_INFO_DIRECT_IO;
1687                 }
1688         }
1689         return res;
1690 }
1691
1692 static void
1693 sg_finish_rem_req(Sg_request * srp)
1694 {
1695         Sg_fd *sfp = srp->parentfp;
1696         Sg_scatter_hold *req_schp = &srp->data;
1697
1698         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1699         if (srp->res_used)
1700                 sg_unlink_reserve(sfp, srp);
1701         else
1702                 sg_remove_scat(req_schp);
1703
1704         if (srp->rq) {
1705                 if (srp->bio)
1706                         blk_rq_unmap_user(srp->bio);
1707
1708                 blk_put_request(srp->rq);
1709         }
1710
1711         sg_remove_request(sfp, srp);
1712 }
1713
1714 static int
1715 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1716 {
1717         int sg_bufflen = tablesize * sizeof(struct page *);
1718         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1719
1720         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1721         if (!schp->pages)
1722                 return -ENOMEM;
1723         schp->sglist_len = sg_bufflen;
1724         return tablesize;       /* number of scat_gath elements allocated */
1725 }
1726
1727 static int
1728 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1729 {
1730         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1731         int sg_tablesize = sfp->parentdp->sg_tablesize;
1732         int blk_size = buff_size, order;
1733         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1734
1735         if (blk_size < 0)
1736                 return -EFAULT;
1737         if (0 == blk_size)
1738                 ++blk_size;     /* don't know why */
1739 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1740         blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
1741         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1742                                    buff_size, blk_size));
1743
1744         /* N.B. ret_sz carried into this block ... */
1745         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1746         if (mx_sc_elems < 0)
1747                 return mx_sc_elems;     /* most likely -ENOMEM */
1748
1749         num = scatter_elem_sz;
1750         if (unlikely(num != scatter_elem_sz_prev)) {
1751                 if (num < PAGE_SIZE) {
1752                         scatter_elem_sz = PAGE_SIZE;
1753                         scatter_elem_sz_prev = PAGE_SIZE;
1754                 } else
1755                         scatter_elem_sz_prev = num;
1756         }
1757
1758         if (sfp->low_dma)
1759                 gfp_mask |= GFP_DMA;
1760
1761         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1762                 gfp_mask |= __GFP_ZERO;
1763
1764         order = get_order(num);
1765 retry:
1766         ret_sz = 1 << (PAGE_SHIFT + order);
1767
1768         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1769              k++, rem_sz -= ret_sz) {
1770
1771                 num = (rem_sz > scatter_elem_sz_prev) ?
1772                         scatter_elem_sz_prev : rem_sz;
1773
1774                 schp->pages[k] = alloc_pages(gfp_mask, order);
1775                 if (!schp->pages[k])
1776                         goto out;
1777
1778                 if (num == scatter_elem_sz_prev) {
1779                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1780                                 scatter_elem_sz = ret_sz;
1781                                 scatter_elem_sz_prev = ret_sz;
1782                         }
1783                 }
1784
1785                 SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k=%d, num=%d, "
1786                                  "ret_sz=%d\n", k, num, ret_sz));
1787         }               /* end of for loop */
1788
1789         schp->page_order = order;
1790         schp->k_use_sg = k;
1791         SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, "
1792                          "rem_sz=%d\n", k, rem_sz));
1793
1794         schp->bufflen = blk_size;
1795         if (rem_sz > 0) /* must have failed */
1796                 return -ENOMEM;
1797         return 0;
1798 out:
1799         for (i = 0; i < k; i++)
1800                 __free_pages(schp->pages[k], order);
1801
1802         if (--order >= 0)
1803                 goto retry;
1804
1805         return -ENOMEM;
1806 }
1807
1808 static void
1809 sg_remove_scat(Sg_scatter_hold * schp)
1810 {
1811         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1812         if (schp->pages && schp->sglist_len > 0) {
1813                 if (!schp->dio_in_use) {
1814                         int k;
1815
1816                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1817                                 SCSI_LOG_TIMEOUT(5, printk(
1818                                     "sg_remove_scat: k=%d, pg=0x%p\n",
1819                                     k, schp->pages[k]));
1820                                 __free_pages(schp->pages[k], schp->page_order);
1821                         }
1822
1823                         kfree(schp->pages);
1824                 }
1825         }
1826         memset(schp, 0, sizeof (*schp));
1827 }
1828
1829 static int
1830 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1831 {
1832         Sg_scatter_hold *schp = &srp->data;
1833         int k, num;
1834
1835         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
1836                                    num_read_xfer));
1837         if ((!outp) || (num_read_xfer <= 0))
1838                 return 0;
1839
1840         num = 1 << (PAGE_SHIFT + schp->page_order);
1841         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1842                 if (num > num_read_xfer) {
1843                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1844                                            num_read_xfer))
1845                                 return -EFAULT;
1846                         break;
1847                 } else {
1848                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1849                                            num))
1850                                 return -EFAULT;
1851                         num_read_xfer -= num;
1852                         if (num_read_xfer <= 0)
1853                                 break;
1854                         outp += num;
1855                 }
1856         }
1857
1858         return 0;
1859 }
1860
1861 static void
1862 sg_build_reserve(Sg_fd * sfp, int req_size)
1863 {
1864         Sg_scatter_hold *schp = &sfp->reserve;
1865
1866         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
1867         do {
1868                 if (req_size < PAGE_SIZE)
1869                         req_size = PAGE_SIZE;
1870                 if (0 == sg_build_indirect(schp, sfp, req_size))
1871                         return;
1872                 else
1873                         sg_remove_scat(schp);
1874                 req_size >>= 1; /* divide by 2 */
1875         } while (req_size > (PAGE_SIZE / 2));
1876 }
1877
1878 static void
1879 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1880 {
1881         Sg_scatter_hold *req_schp = &srp->data;
1882         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1883         int k, num, rem;
1884
1885         srp->res_used = 1;
1886         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
1887         rem = size;
1888
1889         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1890         for (k = 0; k < rsv_schp->k_use_sg; k++) {
1891                 if (rem <= num) {
1892                         req_schp->k_use_sg = k + 1;
1893                         req_schp->sglist_len = rsv_schp->sglist_len;
1894                         req_schp->pages = rsv_schp->pages;
1895
1896                         req_schp->bufflen = size;
1897                         req_schp->page_order = rsv_schp->page_order;
1898                         break;
1899                 } else
1900                         rem -= num;
1901         }
1902
1903         if (k >= rsv_schp->k_use_sg)
1904                 SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
1905 }
1906
1907 static void
1908 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
1909 {
1910         Sg_scatter_hold *req_schp = &srp->data;
1911
1912         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
1913                                    (int) req_schp->k_use_sg));
1914         req_schp->k_use_sg = 0;
1915         req_schp->bufflen = 0;
1916         req_schp->pages = NULL;
1917         req_schp->page_order = 0;
1918         req_schp->sglist_len = 0;
1919         sfp->save_scat_len = 0;
1920         srp->res_used = 0;
1921 }
1922
1923 static Sg_request *
1924 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
1925 {
1926         Sg_request *resp;
1927         unsigned long iflags;
1928
1929         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1930         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
1931                 /* look for requests that are ready + not SG_IO owned */
1932                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
1933                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
1934                         resp->done = 2; /* guard against other readers */
1935                         break;
1936                 }
1937         }
1938         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1939         return resp;
1940 }
1941
1942 #ifdef CONFIG_SCSI_PROC_FS
1943 static Sg_request *
1944 sg_get_nth_request(Sg_fd * sfp, int nth)
1945 {
1946         Sg_request *resp;
1947         unsigned long iflags;
1948         int k;
1949
1950         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1951         for (k = 0, resp = sfp->headrp; resp && (k < nth);
1952              ++k, resp = resp->nextrp) ;
1953         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1954         return resp;
1955 }
1956 #endif
1957
1958 /* always adds to end of list */
1959 static Sg_request *
1960 sg_add_request(Sg_fd * sfp)
1961 {
1962         int k;
1963         unsigned long iflags;
1964         Sg_request *resp;
1965         Sg_request *rp = sfp->req_arr;
1966
1967         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1968         resp = sfp->headrp;
1969         if (!resp) {
1970                 memset(rp, 0, sizeof (Sg_request));
1971                 rp->parentfp = sfp;
1972                 resp = rp;
1973                 sfp->headrp = resp;
1974         } else {
1975                 if (0 == sfp->cmd_q)
1976                         resp = NULL;    /* command queuing disallowed */
1977                 else {
1978                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
1979                                 if (!rp->parentfp)
1980                                         break;
1981                         }
1982                         if (k < SG_MAX_QUEUE) {
1983                                 memset(rp, 0, sizeof (Sg_request));
1984                                 rp->parentfp = sfp;
1985                                 while (resp->nextrp)
1986                                         resp = resp->nextrp;
1987                                 resp->nextrp = rp;
1988                                 resp = rp;
1989                         } else
1990                                 resp = NULL;
1991                 }
1992         }
1993         if (resp) {
1994                 resp->nextrp = NULL;
1995                 resp->header.duration = jiffies_to_msecs(jiffies);
1996         }
1997         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1998         return resp;
1999 }
2000
2001 /* Return of 1 for found; 0 for not found */
2002 static int
2003 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2004 {
2005         Sg_request *prev_rp;
2006         Sg_request *rp;
2007         unsigned long iflags;
2008         int res = 0;
2009
2010         if ((!sfp) || (!srp) || (!sfp->headrp))
2011                 return res;
2012         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2013         prev_rp = sfp->headrp;
2014         if (srp == prev_rp) {
2015                 sfp->headrp = prev_rp->nextrp;
2016                 prev_rp->parentfp = NULL;
2017                 res = 1;
2018         } else {
2019                 while ((rp = prev_rp->nextrp)) {
2020                         if (srp == rp) {
2021                                 prev_rp->nextrp = rp->nextrp;
2022                                 rp->parentfp = NULL;
2023                                 res = 1;
2024                                 break;
2025                         }
2026                         prev_rp = rp;
2027                 }
2028         }
2029         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2030         return res;
2031 }
2032
2033 #ifdef CONFIG_SCSI_PROC_FS
2034 static Sg_fd *
2035 sg_get_nth_sfp(Sg_device * sdp, int nth)
2036 {
2037         Sg_fd *resp;
2038         unsigned long iflags;
2039         int k;
2040
2041         read_lock_irqsave(&sg_index_lock, iflags);
2042         for (k = 0, resp = sdp->headfp; resp && (k < nth);
2043              ++k, resp = resp->nextfp) ;
2044         read_unlock_irqrestore(&sg_index_lock, iflags);
2045         return resp;
2046 }
2047 #endif
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         sfp->timeout = SG_DEFAULT_TIMEOUT;
2064         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2065         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2066         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2067             sdp->device->host->unchecked_isa_dma : 1;
2068         sfp->cmd_q = SG_DEF_COMMAND_Q;
2069         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2070         sfp->parentdp = sdp;
2071         write_lock_irqsave(&sg_index_lock, iflags);
2072         if (!sdp->headfp)
2073                 sdp->headfp = sfp;
2074         else {                  /* add to tail of existing list */
2075                 Sg_fd *pfp = sdp->headfp;
2076                 while (pfp->nextfp)
2077                         pfp = pfp->nextfp;
2078                 pfp->nextfp = sfp;
2079         }
2080         write_unlock_irqrestore(&sg_index_lock, iflags);
2081         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2082         if (unlikely(sg_big_buff != def_reserved_size))
2083                 sg_big_buff = def_reserved_size;
2084
2085         bufflen = min_t(int, sg_big_buff,
2086                         sdp->device->request_queue->max_sectors * 512);
2087         sg_build_reserve(sfp, bufflen);
2088         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2089                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2090         return sfp;
2091 }
2092
2093 static void
2094 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2095 {
2096         Sg_fd *fp;
2097         Sg_fd *prev_fp;
2098
2099         prev_fp = sdp->headfp;
2100         if (sfp == prev_fp)
2101                 sdp->headfp = prev_fp->nextfp;
2102         else {
2103                 while ((fp = prev_fp->nextfp)) {
2104                         if (sfp == fp) {
2105                                 prev_fp->nextfp = fp->nextfp;
2106                                 break;
2107                         }
2108                         prev_fp = fp;
2109                 }
2110         }
2111         if (sfp->reserve.bufflen > 0) {
2112                 SCSI_LOG_TIMEOUT(6, 
2113                         printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2114                         (int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2115                 sg_remove_scat(&sfp->reserve);
2116         }
2117         sfp->parentdp = NULL;
2118         SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2119         kfree(sfp);
2120 }
2121
2122 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2123 static int
2124 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2125 {
2126         Sg_request *srp;
2127         Sg_request *tsrp;
2128         int dirty = 0;
2129         int res = 0;
2130
2131         for (srp = sfp->headrp; srp; srp = tsrp) {
2132                 tsrp = srp->nextrp;
2133                 if (sg_srp_done(srp, sfp))
2134                         sg_finish_rem_req(srp);
2135                 else
2136                         ++dirty;
2137         }
2138         if (0 == dirty) {
2139                 unsigned long iflags;
2140
2141                 write_lock_irqsave(&sg_index_lock, iflags);
2142                 __sg_remove_sfp(sdp, sfp);
2143                 if (sdp->detached && (NULL == sdp->headfp)) {
2144                         idr_remove(&sg_index_idr, sdp->index);
2145                         kfree(sdp);
2146                         res = 1;
2147                 }
2148                 write_unlock_irqrestore(&sg_index_lock, iflags);
2149         } else {
2150                 /* MOD_INC's to inhibit unloading sg and associated adapter driver */
2151                 /* only bump the access_count if we actually succeeded in
2152                  * throwing another counter on the host module */
2153                 scsi_device_get(sdp->device);   /* XXX: retval ignored? */      
2154                 sfp->closed = 1;        /* flag dirty state on this fd */
2155                 SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2156                                   dirty));
2157         }
2158         return res;
2159 }
2160
2161 static int
2162 sg_res_in_use(Sg_fd * sfp)
2163 {
2164         const Sg_request *srp;
2165         unsigned long iflags;
2166
2167         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2168         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2169                 if (srp->res_used)
2170                         break;
2171         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2172         return srp ? 1 : 0;
2173 }
2174
2175 #ifdef CONFIG_SCSI_PROC_FS
2176 static int
2177 sg_idr_max_id(int id, void *p, void *data)
2178 {
2179         int *k = data;
2180
2181         if (*k < id)
2182                 *k = id;
2183
2184         return 0;
2185 }
2186
2187 static int
2188 sg_last_dev(void)
2189 {
2190         int k = -1;
2191         unsigned long iflags;
2192
2193         read_lock_irqsave(&sg_index_lock, iflags);
2194         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2195         read_unlock_irqrestore(&sg_index_lock, iflags);
2196         return k + 1;           /* origin 1 */
2197 }
2198 #endif
2199
2200 static Sg_device *
2201 sg_get_dev(int dev)
2202 {
2203         Sg_device *sdp;
2204         unsigned long iflags;
2205
2206         read_lock_irqsave(&sg_index_lock, iflags);
2207         sdp = idr_find(&sg_index_idr, dev);
2208         read_unlock_irqrestore(&sg_index_lock, iflags);
2209
2210         return sdp;
2211 }
2212
2213 #ifdef CONFIG_SCSI_PROC_FS
2214
2215 static struct proc_dir_entry *sg_proc_sgp = NULL;
2216
2217 static char sg_proc_sg_dirname[] = "scsi/sg";
2218
2219 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2220
2221 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2222 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2223                                   size_t count, loff_t *off);
2224 static struct file_operations adio_fops = {
2225         /* .owner, .read and .llseek added in sg_proc_init() */
2226         .open = sg_proc_single_open_adio,
2227         .write = sg_proc_write_adio,
2228         .release = single_release,
2229 };
2230
2231 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2232 static ssize_t sg_proc_write_dressz(struct file *filp, 
2233                 const char __user *buffer, size_t count, loff_t *off);
2234 static struct file_operations dressz_fops = {
2235         .open = sg_proc_single_open_dressz,
2236         .write = sg_proc_write_dressz,
2237         .release = single_release,
2238 };
2239
2240 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2241 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2242 static struct file_operations version_fops = {
2243         .open = sg_proc_single_open_version,
2244         .release = single_release,
2245 };
2246
2247 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2248 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2249 static struct file_operations devhdr_fops = {
2250         .open = sg_proc_single_open_devhdr,
2251         .release = single_release,
2252 };
2253
2254 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2255 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2256 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2257 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2258 static void dev_seq_stop(struct seq_file *s, void *v);
2259 static struct file_operations dev_fops = {
2260         .open = sg_proc_open_dev,
2261         .release = seq_release,
2262 };
2263 static struct seq_operations dev_seq_ops = {
2264         .start = dev_seq_start,
2265         .next  = dev_seq_next,
2266         .stop  = dev_seq_stop,
2267         .show  = sg_proc_seq_show_dev,
2268 };
2269
2270 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2271 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2272 static struct file_operations devstrs_fops = {
2273         .open = sg_proc_open_devstrs,
2274         .release = seq_release,
2275 };
2276 static struct seq_operations devstrs_seq_ops = {
2277         .start = dev_seq_start,
2278         .next  = dev_seq_next,
2279         .stop  = dev_seq_stop,
2280         .show  = sg_proc_seq_show_devstrs,
2281 };
2282
2283 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2284 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2285 static struct file_operations debug_fops = {
2286         .open = sg_proc_open_debug,
2287         .release = seq_release,
2288 };
2289 static struct seq_operations debug_seq_ops = {
2290         .start = dev_seq_start,
2291         .next  = dev_seq_next,
2292         .stop  = dev_seq_stop,
2293         .show  = sg_proc_seq_show_debug,
2294 };
2295
2296
2297 struct sg_proc_leaf {
2298         const char * name;
2299         struct file_operations * fops;
2300 };
2301
2302 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2303         {"allow_dio", &adio_fops},
2304         {"debug", &debug_fops},
2305         {"def_reserved_size", &dressz_fops},
2306         {"device_hdr", &devhdr_fops},
2307         {"devices", &dev_fops},
2308         {"device_strs", &devstrs_fops},
2309         {"version", &version_fops}
2310 };
2311
2312 static int
2313 sg_proc_init(void)
2314 {
2315         int k, mask;
2316         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2317         struct sg_proc_leaf * leaf;
2318
2319         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2320         if (!sg_proc_sgp)
2321                 return 1;
2322         for (k = 0; k < num_leaves; ++k) {
2323                 leaf = &sg_proc_leaf_arr[k];
2324                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2325                 leaf->fops->owner = THIS_MODULE;
2326                 leaf->fops->read = seq_read;
2327                 leaf->fops->llseek = seq_lseek;
2328                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2329         }
2330         return 0;
2331 }
2332
2333 static void
2334 sg_proc_cleanup(void)
2335 {
2336         int k;
2337         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2338
2339         if (!sg_proc_sgp)
2340                 return;
2341         for (k = 0; k < num_leaves; ++k)
2342                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2343         remove_proc_entry(sg_proc_sg_dirname, NULL);
2344 }
2345
2346
2347 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2348 {
2349         seq_printf(s, "%d\n", *((int *)s->private));
2350         return 0;
2351 }
2352
2353 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2354 {
2355         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2356 }
2357
2358 static ssize_t 
2359 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2360                    size_t count, loff_t *off)
2361 {
2362         int num;
2363         char buff[11];
2364
2365         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2366                 return -EACCES;
2367         num = (count < 10) ? count : 10;
2368         if (copy_from_user(buff, buffer, num))
2369                 return -EFAULT;
2370         buff[num] = '\0';
2371         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2372         return count;
2373 }
2374
2375 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2376 {
2377         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2378 }
2379
2380 static ssize_t 
2381 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2382                      size_t count, loff_t *off)
2383 {
2384         int num;
2385         unsigned long k = ULONG_MAX;
2386         char buff[11];
2387
2388         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2389                 return -EACCES;
2390         num = (count < 10) ? count : 10;
2391         if (copy_from_user(buff, buffer, num))
2392                 return -EFAULT;
2393         buff[num] = '\0';
2394         k = simple_strtoul(buff, NULL, 10);
2395         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2396                 sg_big_buff = k;
2397                 return count;
2398         }
2399         return -ERANGE;
2400 }
2401
2402 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2403 {
2404         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2405                    sg_version_date);
2406         return 0;
2407 }
2408
2409 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2410 {
2411         return single_open(file, sg_proc_seq_show_version, NULL);
2412 }
2413
2414 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2415 {
2416         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2417                    "online\n");
2418         return 0;
2419 }
2420
2421 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2422 {
2423         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2424 }
2425
2426 struct sg_proc_deviter {
2427         loff_t  index;
2428         size_t  max;
2429 };
2430
2431 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2432 {
2433         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2434
2435         s->private = it;
2436         if (! it)
2437                 return NULL;
2438
2439         it->index = *pos;
2440         it->max = sg_last_dev();
2441         if (it->index >= it->max)
2442                 return NULL;
2443         return it;
2444 }
2445
2446 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2447 {
2448         struct sg_proc_deviter * it = s->private;
2449
2450         *pos = ++it->index;
2451         return (it->index < it->max) ? it : NULL;
2452 }
2453
2454 static void dev_seq_stop(struct seq_file *s, void *v)
2455 {
2456         kfree(s->private);
2457 }
2458
2459 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2460 {
2461         return seq_open(file, &dev_seq_ops);
2462 }
2463
2464 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2465 {
2466         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2467         Sg_device *sdp;
2468         struct scsi_device *scsidp;
2469
2470         sdp = it ? sg_get_dev(it->index) : NULL;
2471         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2472                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2473                               scsidp->host->host_no, scsidp->channel,
2474                               scsidp->id, scsidp->lun, (int) scsidp->type,
2475                               1,
2476                               (int) scsidp->queue_depth,
2477                               (int) scsidp->device_busy,
2478                               (int) scsi_device_online(scsidp));
2479         else
2480                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2481         return 0;
2482 }
2483
2484 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2485 {
2486         return seq_open(file, &devstrs_seq_ops);
2487 }
2488
2489 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2490 {
2491         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2492         Sg_device *sdp;
2493         struct scsi_device *scsidp;
2494
2495         sdp = it ? sg_get_dev(it->index) : NULL;
2496         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2497                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2498                            scsidp->vendor, scsidp->model, scsidp->rev);
2499         else
2500                 seq_printf(s, "<no active device>\n");
2501         return 0;
2502 }
2503
2504 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2505 {
2506         int k, m, new_interface, blen, usg;
2507         Sg_request *srp;
2508         Sg_fd *fp;
2509         const sg_io_hdr_t *hp;
2510         const char * cp;
2511         unsigned int ms;
2512
2513         for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
2514                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2515                            "(res)sgat=%d low_dma=%d\n", k + 1,
2516                            jiffies_to_msecs(fp->timeout),
2517                            fp->reserve.bufflen,
2518                            (int) fp->reserve.k_use_sg,
2519                            (int) fp->low_dma);
2520                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2521                            (int) fp->cmd_q, (int) fp->force_packid,
2522                            (int) fp->keep_orphan, (int) fp->closed);
2523                 for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
2524                         hp = &srp->header;
2525                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2526                         if (srp->res_used) {
2527                                 if (new_interface && 
2528                                     (SG_FLAG_MMAP_IO & hp->flags))
2529                                         cp = "     mmap>> ";
2530                                 else
2531                                         cp = "     rb>> ";
2532                         } else {
2533                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2534                                         cp = "     dio>> ";
2535                                 else
2536                                         cp = "     ";
2537                         }
2538                         seq_printf(s, cp);
2539                         blen = srp->data.bufflen;
2540                         usg = srp->data.k_use_sg;
2541                         seq_printf(s, srp->done ? 
2542                                    ((1 == srp->done) ?  "rcv:" : "fin:")
2543                                    : "act:");
2544                         seq_printf(s, " id=%d blen=%d",
2545                                    srp->header.pack_id, blen);
2546                         if (srp->done)
2547                                 seq_printf(s, " dur=%d", hp->duration);
2548                         else {
2549                                 ms = jiffies_to_msecs(jiffies);
2550                                 seq_printf(s, " t_o/elap=%d/%d",
2551                                         (new_interface ? hp->timeout :
2552                                                   jiffies_to_msecs(fp->timeout)),
2553                                         (ms > hp->duration ? ms - hp->duration : 0));
2554                         }
2555                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2556                                    (int) srp->data.cmd_opcode);
2557                 }
2558                 if (0 == m)
2559                         seq_printf(s, "     No requests active\n");
2560         }
2561 }
2562
2563 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2564 {
2565         return seq_open(file, &debug_seq_ops);
2566 }
2567
2568 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2569 {
2570         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2571         Sg_device *sdp;
2572
2573         if (it && (0 == it->index)) {
2574                 seq_printf(s, "max_active_device=%d(origin 1)\n",
2575                            (int)it->max);
2576                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2577         }
2578         sdp = it ? sg_get_dev(it->index) : NULL;
2579         if (sdp) {
2580                 struct scsi_device *scsidp = sdp->device;
2581
2582                 if (NULL == scsidp) {
2583                         seq_printf(s, "device %d detached ??\n", 
2584                                    (int)it->index);
2585                         return 0;
2586                 }
2587
2588                 if (sg_get_nth_sfp(sdp, 0)) {
2589                         seq_printf(s, " >>> device=%s ",
2590                                 sdp->disk->disk_name);
2591                         if (sdp->detached)
2592                                 seq_printf(s, "detached pending close ");
2593                         else
2594                                 seq_printf
2595                                     (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2596                                      scsidp->host->host_no,
2597                                      scsidp->channel, scsidp->id,
2598                                      scsidp->lun,
2599                                      scsidp->host->hostt->emulated);
2600                         seq_printf(s, " sg_tablesize=%d excl=%d\n",
2601                                    sdp->sg_tablesize, sdp->exclude);
2602                 }
2603                 sg_proc_debug_helper(s, sdp);
2604         }
2605         return 0;
2606 }
2607
2608 #endif                          /* CONFIG_SCSI_PROC_FS */
2609
2610 module_init(init_sg);
2611 module_exit(exit_sg);