516925d8b570c3fab05d5d1b0a6b729e0ebce395
[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         int retval;
1158         Sg_device *sdp;
1159         Sg_fd *sfp;
1160
1161         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1162                 return -ENXIO;
1163         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1164                                    sdp->disk->disk_name, mode));
1165
1166         retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
1167         return (retval < 0) ? retval : 0;
1168 }
1169
1170 static int
1171 sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1172 {
1173         Sg_fd *sfp;
1174         unsigned long offset, len, sa;
1175         Sg_scatter_hold *rsv_schp;
1176         int k, length;
1177
1178         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1179                 return VM_FAULT_SIGBUS;
1180         rsv_schp = &sfp->reserve;
1181         offset = vmf->pgoff << PAGE_SHIFT;
1182         if (offset >= rsv_schp->bufflen)
1183                 return VM_FAULT_SIGBUS;
1184         SCSI_LOG_TIMEOUT(3, printk("sg_vma_fault: offset=%lu, scatg=%d\n",
1185                                    offset, rsv_schp->k_use_sg));
1186         sa = vma->vm_start;
1187         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1188         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1189                 len = vma->vm_end - sa;
1190                 len = (len < length) ? len : length;
1191                 if (offset < len) {
1192                         struct page *page = nth_page(rsv_schp->pages[k],
1193                                                      offset >> PAGE_SHIFT);
1194                         get_page(page); /* increment page count */
1195                         vmf->page = page;
1196                         return 0; /* success */
1197                 }
1198                 sa += len;
1199                 offset -= len;
1200         }
1201
1202         return VM_FAULT_SIGBUS;
1203 }
1204
1205 static struct vm_operations_struct sg_mmap_vm_ops = {
1206         .fault = sg_vma_fault,
1207 };
1208
1209 static int
1210 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1211 {
1212         Sg_fd *sfp;
1213         unsigned long req_sz, len, sa;
1214         Sg_scatter_hold *rsv_schp;
1215         int k, length;
1216
1217         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1218                 return -ENXIO;
1219         req_sz = vma->vm_end - vma->vm_start;
1220         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1221                                    (void *) vma->vm_start, (int) req_sz));
1222         if (vma->vm_pgoff)
1223                 return -EINVAL; /* want no offset */
1224         rsv_schp = &sfp->reserve;
1225         if (req_sz > rsv_schp->bufflen)
1226                 return -ENOMEM; /* cannot map more than reserved buffer */
1227
1228         sa = vma->vm_start;
1229         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1230         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1231                 len = vma->vm_end - sa;
1232                 len = (len < length) ? len : length;
1233                 sa += len;
1234         }
1235
1236         sfp->mmap_called = 1;
1237         vma->vm_flags |= VM_RESERVED;
1238         vma->vm_private_data = sfp;
1239         vma->vm_ops = &sg_mmap_vm_ops;
1240         return 0;
1241 }
1242
1243 /*
1244  * This function is a "bottom half" handler that is called by the mid
1245  * level when a command is completed (or has failed).
1246  */
1247 static void sg_rq_end_io(struct request *rq, int uptodate)
1248 {
1249         struct sg_request *srp = rq->end_io_data;
1250         Sg_device *sdp = NULL;
1251         Sg_fd *sfp;
1252         unsigned long iflags;
1253         unsigned int ms;
1254         char *sense;
1255         int result, resid;
1256
1257         if (NULL == srp) {
1258                 printk(KERN_ERR "sg_cmd_done: NULL request\n");
1259                 return;
1260         }
1261         sfp = srp->parentfp;
1262         if (sfp)
1263                 sdp = sfp->parentdp;
1264         if ((NULL == sdp) || sdp->detached) {
1265                 printk(KERN_INFO "sg_cmd_done: device detached\n");
1266                 return;
1267         }
1268
1269         sense = rq->sense;
1270         result = rq->errors;
1271         resid = rq->data_len;
1272
1273         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1274                 sdp->disk->disk_name, srp->header.pack_id, result));
1275         srp->header.resid = resid;
1276         ms = jiffies_to_msecs(jiffies);
1277         srp->header.duration = (ms > srp->header.duration) ?
1278                                 (ms - srp->header.duration) : 0;
1279         if (0 != result) {
1280                 struct scsi_sense_hdr sshdr;
1281
1282                 srp->header.status = 0xff & result;
1283                 srp->header.masked_status = status_byte(result);
1284                 srp->header.msg_status = msg_byte(result);
1285                 srp->header.host_status = host_byte(result);
1286                 srp->header.driver_status = driver_byte(result);
1287                 if ((sdp->sgdebug > 0) &&
1288                     ((CHECK_CONDITION == srp->header.masked_status) ||
1289                      (COMMAND_TERMINATED == srp->header.masked_status)))
1290                         __scsi_print_sense("sg_cmd_done", sense,
1291                                            SCSI_SENSE_BUFFERSIZE);
1292
1293                 /* Following if statement is a patch supplied by Eric Youngdale */
1294                 if (driver_byte(result) != 0
1295                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1296                     && !scsi_sense_is_deferred(&sshdr)
1297                     && sshdr.sense_key == UNIT_ATTENTION
1298                     && sdp->device->removable) {
1299                         /* Detected possible disc change. Set the bit - this */
1300                         /* may be used if there are filesystems using this device */
1301                         sdp->device->changed = 1;
1302                 }
1303         }
1304         /* Rely on write phase to clean out srp status values, so no "else" */
1305
1306         if (sfp->closed) {      /* whoops this fd already released, cleanup */
1307                 SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
1308                 sg_finish_rem_req(srp);
1309                 srp = NULL;
1310                 if (NULL == sfp->headrp) {
1311                         SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, final cleanup\n"));
1312                         if (0 == sg_remove_sfp(sdp, sfp)) {     /* device still present */
1313                                 scsi_device_put(sdp->device);
1314                         }
1315                         sfp = NULL;
1316                 }
1317         } else if (srp && srp->orphan) {
1318                 if (sfp->keep_orphan)
1319                         srp->sg_io_owned = 0;
1320                 else {
1321                         sg_finish_rem_req(srp);
1322                         srp = NULL;
1323                 }
1324         }
1325         if (sfp && srp) {
1326                 /* Now wake up any sg_read() that is waiting for this packet. */
1327                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1328                 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1329                 srp->done = 1;
1330                 wake_up_interruptible(&sfp->read_wait);
1331                 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1332         }
1333 }
1334
1335 static struct file_operations sg_fops = {
1336         .owner = THIS_MODULE,
1337         .read = sg_read,
1338         .write = sg_write,
1339         .poll = sg_poll,
1340         .ioctl = sg_ioctl,
1341 #ifdef CONFIG_COMPAT
1342         .compat_ioctl = sg_compat_ioctl,
1343 #endif
1344         .open = sg_open,
1345         .mmap = sg_mmap,
1346         .release = sg_release,
1347         .fasync = sg_fasync,
1348 };
1349
1350 static struct class *sg_sysfs_class;
1351
1352 static int sg_sysfs_valid = 0;
1353
1354 static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1355 {
1356         struct request_queue *q = scsidp->request_queue;
1357         Sg_device *sdp;
1358         unsigned long iflags;
1359         int error;
1360         u32 k;
1361
1362         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1363         if (!sdp) {
1364                 printk(KERN_WARNING "kmalloc Sg_device failure\n");
1365                 return ERR_PTR(-ENOMEM);
1366         }
1367         error = -ENOMEM;
1368         if (!idr_pre_get(&sg_index_idr, GFP_KERNEL)) {
1369                 printk(KERN_WARNING "idr expansion Sg_device failure\n");
1370                 goto out;
1371         }
1372
1373         write_lock_irqsave(&sg_index_lock, iflags);
1374         error = idr_get_new(&sg_index_idr, sdp, &k);
1375         write_unlock_irqrestore(&sg_index_lock, iflags);
1376
1377         if (error) {
1378                 printk(KERN_WARNING "idr allocation Sg_device failure: %d\n",
1379                        error);
1380                 goto out;
1381         }
1382
1383         if (unlikely(k >= SG_MAX_DEVS))
1384                 goto overflow;
1385
1386         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1387         sprintf(disk->disk_name, "sg%d", k);
1388         disk->first_minor = k;
1389         sdp->disk = disk;
1390         sdp->device = scsidp;
1391         init_waitqueue_head(&sdp->o_excl_wait);
1392         sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments);
1393         sdp->index = k;
1394
1395         error = 0;
1396  out:
1397         if (error) {
1398                 kfree(sdp);
1399                 return ERR_PTR(error);
1400         }
1401         return sdp;
1402
1403  overflow:
1404         sdev_printk(KERN_WARNING, scsidp,
1405                     "Unable to attach sg device type=%d, minor "
1406                     "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1407         error = -ENODEV;
1408         goto out;
1409 }
1410
1411 static int
1412 sg_add(struct device *cl_dev, struct class_interface *cl_intf)
1413 {
1414         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1415         struct gendisk *disk;
1416         Sg_device *sdp = NULL;
1417         struct cdev * cdev = NULL;
1418         int error;
1419         unsigned long iflags;
1420
1421         disk = alloc_disk(1);
1422         if (!disk) {
1423                 printk(KERN_WARNING "alloc_disk failed\n");
1424                 return -ENOMEM;
1425         }
1426         disk->major = SCSI_GENERIC_MAJOR;
1427
1428         error = -ENOMEM;
1429         cdev = cdev_alloc();
1430         if (!cdev) {
1431                 printk(KERN_WARNING "cdev_alloc failed\n");
1432                 goto out;
1433         }
1434         cdev->owner = THIS_MODULE;
1435         cdev->ops = &sg_fops;
1436
1437         sdp = sg_alloc(disk, scsidp);
1438         if (IS_ERR(sdp)) {
1439                 printk(KERN_WARNING "sg_alloc failed\n");
1440                 error = PTR_ERR(sdp);
1441                 goto out;
1442         }
1443
1444         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1445         if (error)
1446                 goto cdev_add_err;
1447
1448         sdp->cdev = cdev;
1449         if (sg_sysfs_valid) {
1450                 struct device *sg_class_member;
1451
1452                 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1453                                                 MKDEV(SCSI_GENERIC_MAJOR,
1454                                                       sdp->index),
1455                                                 sdp, "%s", disk->disk_name);
1456                 if (IS_ERR(sg_class_member)) {
1457                         printk(KERN_ERR "sg_add: "
1458                                "device_create failed\n");
1459                         error = PTR_ERR(sg_class_member);
1460                         goto cdev_add_err;
1461                 }
1462                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1463                                           &sg_class_member->kobj, "generic");
1464                 if (error)
1465                         printk(KERN_ERR "sg_add: unable to make symlink "
1466                                         "'generic' back to sg%d\n", sdp->index);
1467         } else
1468                 printk(KERN_WARNING "sg_add: sg_sys Invalid\n");
1469
1470         sdev_printk(KERN_NOTICE, scsidp,
1471                     "Attached scsi generic sg%d type %d\n", sdp->index,
1472                     scsidp->type);
1473
1474         dev_set_drvdata(cl_dev, sdp);
1475
1476         return 0;
1477
1478 cdev_add_err:
1479         write_lock_irqsave(&sg_index_lock, iflags);
1480         idr_remove(&sg_index_idr, sdp->index);
1481         write_unlock_irqrestore(&sg_index_lock, iflags);
1482         kfree(sdp);
1483
1484 out:
1485         put_disk(disk);
1486         if (cdev)
1487                 cdev_del(cdev);
1488         return error;
1489 }
1490
1491 static void
1492 sg_remove(struct device *cl_dev, struct class_interface *cl_intf)
1493 {
1494         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1495         Sg_device *sdp = dev_get_drvdata(cl_dev);
1496         unsigned long iflags;
1497         Sg_fd *sfp;
1498         Sg_fd *tsfp;
1499         Sg_request *srp;
1500         Sg_request *tsrp;
1501         int delay;
1502
1503         if (!sdp)
1504                 return;
1505
1506         delay = 0;
1507         write_lock_irqsave(&sg_index_lock, iflags);
1508         if (sdp->headfp) {
1509                 sdp->detached = 1;
1510                 for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1511                         tsfp = sfp->nextfp;
1512                         for (srp = sfp->headrp; srp; srp = tsrp) {
1513                                 tsrp = srp->nextrp;
1514                                 if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
1515                                         sg_finish_rem_req(srp);
1516                         }
1517                         if (sfp->closed) {
1518                                 scsi_device_put(sdp->device);
1519                                 __sg_remove_sfp(sdp, sfp);
1520                         } else {
1521                                 delay = 1;
1522                                 wake_up_interruptible(&sfp->read_wait);
1523                                 kill_fasync(&sfp->async_qp, SIGPOLL,
1524                                             POLL_HUP);
1525                         }
1526                 }
1527                 SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d, dirty\n", sdp->index));
1528                 if (NULL == sdp->headfp) {
1529                         idr_remove(&sg_index_idr, sdp->index);
1530                 }
1531         } else {        /* nothing active, simple case */
1532                 SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d\n", sdp->index));
1533                 idr_remove(&sg_index_idr, sdp->index);
1534         }
1535         write_unlock_irqrestore(&sg_index_lock, iflags);
1536
1537         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1538         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1539         cdev_del(sdp->cdev);
1540         sdp->cdev = NULL;
1541         put_disk(sdp->disk);
1542         sdp->disk = NULL;
1543         if (NULL == sdp->headfp)
1544                 kfree(sdp);
1545
1546         if (delay)
1547                 msleep(10);     /* dirty detach so delay device destruction */
1548 }
1549
1550 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1551 module_param_named(def_reserved_size, def_reserved_size, int,
1552                    S_IRUGO | S_IWUSR);
1553 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1554
1555 MODULE_AUTHOR("Douglas Gilbert");
1556 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1557 MODULE_LICENSE("GPL");
1558 MODULE_VERSION(SG_VERSION_STR);
1559 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1560
1561 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1562                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1563 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1564 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1565
1566 static int __init
1567 init_sg(void)
1568 {
1569         int rc;
1570
1571         if (scatter_elem_sz < PAGE_SIZE) {
1572                 scatter_elem_sz = PAGE_SIZE;
1573                 scatter_elem_sz_prev = scatter_elem_sz;
1574         }
1575         if (def_reserved_size >= 0)
1576                 sg_big_buff = def_reserved_size;
1577         else
1578                 def_reserved_size = sg_big_buff;
1579
1580         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), 
1581                                     SG_MAX_DEVS, "sg");
1582         if (rc)
1583                 return rc;
1584         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1585         if ( IS_ERR(sg_sysfs_class) ) {
1586                 rc = PTR_ERR(sg_sysfs_class);
1587                 goto err_out;
1588         }
1589         sg_sysfs_valid = 1;
1590         rc = scsi_register_interface(&sg_interface);
1591         if (0 == rc) {
1592 #ifdef CONFIG_SCSI_PROC_FS
1593                 sg_proc_init();
1594 #endif                          /* CONFIG_SCSI_PROC_FS */
1595                 return 0;
1596         }
1597         class_destroy(sg_sysfs_class);
1598 err_out:
1599         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1600         return rc;
1601 }
1602
1603 static void __exit
1604 exit_sg(void)
1605 {
1606 #ifdef CONFIG_SCSI_PROC_FS
1607         sg_proc_cleanup();
1608 #endif                          /* CONFIG_SCSI_PROC_FS */
1609         scsi_unregister_interface(&sg_interface);
1610         class_destroy(sg_sysfs_class);
1611         sg_sysfs_valid = 0;
1612         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1613                                  SG_MAX_DEVS);
1614         idr_destroy(&sg_index_idr);
1615 }
1616
1617 static int sg_start_req(Sg_request *srp, unsigned char *cmd)
1618 {
1619         int res;
1620         struct request *rq;
1621         Sg_fd *sfp = srp->parentfp;
1622         sg_io_hdr_t *hp = &srp->header;
1623         int dxfer_len = (int) hp->dxfer_len;
1624         int dxfer_dir = hp->dxfer_direction;
1625         unsigned int iov_count = hp->iovec_count;
1626         Sg_scatter_hold *req_schp = &srp->data;
1627         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1628         struct request_queue *q = sfp->parentdp->device->request_queue;
1629         struct rq_map_data *md, map_data;
1630         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1631
1632         SCSI_LOG_TIMEOUT(4, printk(KERN_INFO "sg_start_req: dxfer_len=%d\n",
1633                                    dxfer_len));
1634
1635         rq = blk_get_request(q, rw, GFP_ATOMIC);
1636         if (!rq)
1637                 return -ENOMEM;
1638
1639         memcpy(rq->cmd, cmd, hp->cmd_len);
1640
1641         rq->cmd_len = hp->cmd_len;
1642         rq->cmd_type = REQ_TYPE_BLOCK_PC;
1643
1644         srp->rq = rq;
1645         rq->end_io_data = srp;
1646         rq->sense = srp->sense_b;
1647         rq->retries = SG_DEFAULT_RETRIES;
1648
1649         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1650                 return 0;
1651
1652         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1653             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1654             !sfp->parentdp->device->host->unchecked_isa_dma &&
1655             blk_rq_aligned(q, hp->dxferp, dxfer_len))
1656                 md = NULL;
1657         else
1658                 md = &map_data;
1659
1660         if (md) {
1661                 if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen)
1662                         sg_link_reserve(sfp, srp, dxfer_len);
1663                 else {
1664                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1665                         if (res)
1666                                 return res;
1667                 }
1668
1669                 md->pages = req_schp->pages;
1670                 md->page_order = req_schp->page_order;
1671                 md->nr_entries = req_schp->k_use_sg;
1672                 md->offset = 0;
1673                 md->null_mapped = hp->dxferp ? 0 : 1;
1674         }
1675
1676         if (iov_count)
1677                 res = blk_rq_map_user_iov(q, rq, md, hp->dxferp, iov_count,
1678                                           hp->dxfer_len, GFP_ATOMIC);
1679         else
1680                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1681                                       hp->dxfer_len, GFP_ATOMIC);
1682
1683         if (!res) {
1684                 srp->bio = rq->bio;
1685
1686                 if (!md) {
1687                         req_schp->dio_in_use = 1;
1688                         hp->info |= SG_INFO_DIRECT_IO;
1689                 }
1690         }
1691         return res;
1692 }
1693
1694 static void
1695 sg_finish_rem_req(Sg_request * srp)
1696 {
1697         Sg_fd *sfp = srp->parentfp;
1698         Sg_scatter_hold *req_schp = &srp->data;
1699
1700         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1701         if (srp->res_used)
1702                 sg_unlink_reserve(sfp, srp);
1703         else
1704                 sg_remove_scat(req_schp);
1705
1706         if (srp->rq) {
1707                 if (srp->bio)
1708                         blk_rq_unmap_user(srp->bio);
1709
1710                 blk_put_request(srp->rq);
1711         }
1712
1713         sg_remove_request(sfp, srp);
1714 }
1715
1716 static int
1717 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1718 {
1719         int sg_bufflen = tablesize * sizeof(struct page *);
1720         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1721
1722         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1723         if (!schp->pages)
1724                 return -ENOMEM;
1725         schp->sglist_len = sg_bufflen;
1726         return tablesize;       /* number of scat_gath elements allocated */
1727 }
1728
1729 static int
1730 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1731 {
1732         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1733         int sg_tablesize = sfp->parentdp->sg_tablesize;
1734         int blk_size = buff_size, order;
1735         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1736
1737         if (blk_size < 0)
1738                 return -EFAULT;
1739         if (0 == blk_size)
1740                 ++blk_size;     /* don't know why */
1741 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1742         blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
1743         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1744                                    buff_size, blk_size));
1745
1746         /* N.B. ret_sz carried into this block ... */
1747         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1748         if (mx_sc_elems < 0)
1749                 return mx_sc_elems;     /* most likely -ENOMEM */
1750
1751         num = scatter_elem_sz;
1752         if (unlikely(num != scatter_elem_sz_prev)) {
1753                 if (num < PAGE_SIZE) {
1754                         scatter_elem_sz = PAGE_SIZE;
1755                         scatter_elem_sz_prev = PAGE_SIZE;
1756                 } else
1757                         scatter_elem_sz_prev = num;
1758         }
1759
1760         if (sfp->low_dma)
1761                 gfp_mask |= GFP_DMA;
1762
1763         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1764                 gfp_mask |= __GFP_ZERO;
1765
1766         order = get_order(num);
1767 retry:
1768         ret_sz = 1 << (PAGE_SHIFT + order);
1769
1770         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1771              k++, rem_sz -= ret_sz) {
1772
1773                 num = (rem_sz > scatter_elem_sz_prev) ?
1774                         scatter_elem_sz_prev : rem_sz;
1775
1776                 schp->pages[k] = alloc_pages(gfp_mask, order);
1777                 if (!schp->pages[k])
1778                         goto out;
1779
1780                 if (num == scatter_elem_sz_prev) {
1781                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1782                                 scatter_elem_sz = ret_sz;
1783                                 scatter_elem_sz_prev = ret_sz;
1784                         }
1785                 }
1786
1787                 SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k=%d, num=%d, "
1788                                  "ret_sz=%d\n", k, num, ret_sz));
1789         }               /* end of for loop */
1790
1791         schp->page_order = order;
1792         schp->k_use_sg = k;
1793         SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, "
1794                          "rem_sz=%d\n", k, rem_sz));
1795
1796         schp->bufflen = blk_size;
1797         if (rem_sz > 0) /* must have failed */
1798                 return -ENOMEM;
1799         return 0;
1800 out:
1801         for (i = 0; i < k; i++)
1802                 __free_pages(schp->pages[k], order);
1803
1804         if (--order >= 0)
1805                 goto retry;
1806
1807         return -ENOMEM;
1808 }
1809
1810 static void
1811 sg_remove_scat(Sg_scatter_hold * schp)
1812 {
1813         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1814         if (schp->pages && schp->sglist_len > 0) {
1815                 if (!schp->dio_in_use) {
1816                         int k;
1817
1818                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1819                                 SCSI_LOG_TIMEOUT(5, printk(
1820                                     "sg_remove_scat: k=%d, pg=0x%p\n",
1821                                     k, schp->pages[k]));
1822                                 __free_pages(schp->pages[k], schp->page_order);
1823                         }
1824
1825                         kfree(schp->pages);
1826                 }
1827         }
1828         memset(schp, 0, sizeof (*schp));
1829 }
1830
1831 static int
1832 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1833 {
1834         Sg_scatter_hold *schp = &srp->data;
1835         int k, num;
1836
1837         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
1838                                    num_read_xfer));
1839         if ((!outp) || (num_read_xfer <= 0))
1840                 return 0;
1841
1842         num = 1 << (PAGE_SHIFT + schp->page_order);
1843         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1844                 if (num > num_read_xfer) {
1845                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1846                                            num_read_xfer))
1847                                 return -EFAULT;
1848                         break;
1849                 } else {
1850                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1851                                            num))
1852                                 return -EFAULT;
1853                         num_read_xfer -= num;
1854                         if (num_read_xfer <= 0)
1855                                 break;
1856                         outp += num;
1857                 }
1858         }
1859
1860         return 0;
1861 }
1862
1863 static void
1864 sg_build_reserve(Sg_fd * sfp, int req_size)
1865 {
1866         Sg_scatter_hold *schp = &sfp->reserve;
1867
1868         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
1869         do {
1870                 if (req_size < PAGE_SIZE)
1871                         req_size = PAGE_SIZE;
1872                 if (0 == sg_build_indirect(schp, sfp, req_size))
1873                         return;
1874                 else
1875                         sg_remove_scat(schp);
1876                 req_size >>= 1; /* divide by 2 */
1877         } while (req_size > (PAGE_SIZE / 2));
1878 }
1879
1880 static void
1881 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1882 {
1883         Sg_scatter_hold *req_schp = &srp->data;
1884         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1885         int k, num, rem;
1886
1887         srp->res_used = 1;
1888         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
1889         rem = size;
1890
1891         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1892         for (k = 0; k < rsv_schp->k_use_sg; k++) {
1893                 if (rem <= num) {
1894                         req_schp->k_use_sg = k + 1;
1895                         req_schp->sglist_len = rsv_schp->sglist_len;
1896                         req_schp->pages = rsv_schp->pages;
1897
1898                         req_schp->bufflen = size;
1899                         req_schp->page_order = rsv_schp->page_order;
1900                         break;
1901                 } else
1902                         rem -= num;
1903         }
1904
1905         if (k >= rsv_schp->k_use_sg)
1906                 SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
1907 }
1908
1909 static void
1910 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
1911 {
1912         Sg_scatter_hold *req_schp = &srp->data;
1913
1914         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
1915                                    (int) req_schp->k_use_sg));
1916         req_schp->k_use_sg = 0;
1917         req_schp->bufflen = 0;
1918         req_schp->pages = NULL;
1919         req_schp->page_order = 0;
1920         req_schp->sglist_len = 0;
1921         sfp->save_scat_len = 0;
1922         srp->res_used = 0;
1923 }
1924
1925 static Sg_request *
1926 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
1927 {
1928         Sg_request *resp;
1929         unsigned long iflags;
1930
1931         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1932         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
1933                 /* look for requests that are ready + not SG_IO owned */
1934                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
1935                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
1936                         resp->done = 2; /* guard against other readers */
1937                         break;
1938                 }
1939         }
1940         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1941         return resp;
1942 }
1943
1944 #ifdef CONFIG_SCSI_PROC_FS
1945 static Sg_request *
1946 sg_get_nth_request(Sg_fd * sfp, int nth)
1947 {
1948         Sg_request *resp;
1949         unsigned long iflags;
1950         int k;
1951
1952         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1953         for (k = 0, resp = sfp->headrp; resp && (k < nth);
1954              ++k, resp = resp->nextrp) ;
1955         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1956         return resp;
1957 }
1958 #endif
1959
1960 /* always adds to end of list */
1961 static Sg_request *
1962 sg_add_request(Sg_fd * sfp)
1963 {
1964         int k;
1965         unsigned long iflags;
1966         Sg_request *resp;
1967         Sg_request *rp = sfp->req_arr;
1968
1969         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1970         resp = sfp->headrp;
1971         if (!resp) {
1972                 memset(rp, 0, sizeof (Sg_request));
1973                 rp->parentfp = sfp;
1974                 resp = rp;
1975                 sfp->headrp = resp;
1976         } else {
1977                 if (0 == sfp->cmd_q)
1978                         resp = NULL;    /* command queuing disallowed */
1979                 else {
1980                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
1981                                 if (!rp->parentfp)
1982                                         break;
1983                         }
1984                         if (k < SG_MAX_QUEUE) {
1985                                 memset(rp, 0, sizeof (Sg_request));
1986                                 rp->parentfp = sfp;
1987                                 while (resp->nextrp)
1988                                         resp = resp->nextrp;
1989                                 resp->nextrp = rp;
1990                                 resp = rp;
1991                         } else
1992                                 resp = NULL;
1993                 }
1994         }
1995         if (resp) {
1996                 resp->nextrp = NULL;
1997                 resp->header.duration = jiffies_to_msecs(jiffies);
1998         }
1999         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2000         return resp;
2001 }
2002
2003 /* Return of 1 for found; 0 for not found */
2004 static int
2005 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2006 {
2007         Sg_request *prev_rp;
2008         Sg_request *rp;
2009         unsigned long iflags;
2010         int res = 0;
2011
2012         if ((!sfp) || (!srp) || (!sfp->headrp))
2013                 return res;
2014         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2015         prev_rp = sfp->headrp;
2016         if (srp == prev_rp) {
2017                 sfp->headrp = prev_rp->nextrp;
2018                 prev_rp->parentfp = NULL;
2019                 res = 1;
2020         } else {
2021                 while ((rp = prev_rp->nextrp)) {
2022                         if (srp == rp) {
2023                                 prev_rp->nextrp = rp->nextrp;
2024                                 rp->parentfp = NULL;
2025                                 res = 1;
2026                                 break;
2027                         }
2028                         prev_rp = rp;
2029                 }
2030         }
2031         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2032         return res;
2033 }
2034
2035 #ifdef CONFIG_SCSI_PROC_FS
2036 static Sg_fd *
2037 sg_get_nth_sfp(Sg_device * sdp, int nth)
2038 {
2039         Sg_fd *resp;
2040         unsigned long iflags;
2041         int k;
2042
2043         read_lock_irqsave(&sg_index_lock, iflags);
2044         for (k = 0, resp = sdp->headfp; resp && (k < nth);
2045              ++k, resp = resp->nextfp) ;
2046         read_unlock_irqrestore(&sg_index_lock, iflags);
2047         return resp;
2048 }
2049 #endif
2050
2051 static Sg_fd *
2052 sg_add_sfp(Sg_device * sdp, int dev)
2053 {
2054         Sg_fd *sfp;
2055         unsigned long iflags;
2056         int bufflen;
2057
2058         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2059         if (!sfp)
2060                 return NULL;
2061
2062         init_waitqueue_head(&sfp->read_wait);
2063         rwlock_init(&sfp->rq_list_lock);
2064
2065         sfp->timeout = SG_DEFAULT_TIMEOUT;
2066         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2067         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2068         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2069             sdp->device->host->unchecked_isa_dma : 1;
2070         sfp->cmd_q = SG_DEF_COMMAND_Q;
2071         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2072         sfp->parentdp = sdp;
2073         write_lock_irqsave(&sg_index_lock, iflags);
2074         if (!sdp->headfp)
2075                 sdp->headfp = sfp;
2076         else {                  /* add to tail of existing list */
2077                 Sg_fd *pfp = sdp->headfp;
2078                 while (pfp->nextfp)
2079                         pfp = pfp->nextfp;
2080                 pfp->nextfp = sfp;
2081         }
2082         write_unlock_irqrestore(&sg_index_lock, iflags);
2083         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2084         if (unlikely(sg_big_buff != def_reserved_size))
2085                 sg_big_buff = def_reserved_size;
2086
2087         bufflen = min_t(int, sg_big_buff,
2088                         sdp->device->request_queue->max_sectors * 512);
2089         sg_build_reserve(sfp, bufflen);
2090         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2091                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2092         return sfp;
2093 }
2094
2095 static void
2096 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2097 {
2098         Sg_fd *fp;
2099         Sg_fd *prev_fp;
2100
2101         prev_fp = sdp->headfp;
2102         if (sfp == prev_fp)
2103                 sdp->headfp = prev_fp->nextfp;
2104         else {
2105                 while ((fp = prev_fp->nextfp)) {
2106                         if (sfp == fp) {
2107                                 prev_fp->nextfp = fp->nextfp;
2108                                 break;
2109                         }
2110                         prev_fp = fp;
2111                 }
2112         }
2113         if (sfp->reserve.bufflen > 0) {
2114                 SCSI_LOG_TIMEOUT(6, 
2115                         printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2116                         (int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2117                 sg_remove_scat(&sfp->reserve);
2118         }
2119         sfp->parentdp = NULL;
2120         SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2121         kfree(sfp);
2122 }
2123
2124 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2125 static int
2126 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2127 {
2128         Sg_request *srp;
2129         Sg_request *tsrp;
2130         int dirty = 0;
2131         int res = 0;
2132
2133         for (srp = sfp->headrp; srp; srp = tsrp) {
2134                 tsrp = srp->nextrp;
2135                 if (sg_srp_done(srp, sfp))
2136                         sg_finish_rem_req(srp);
2137                 else
2138                         ++dirty;
2139         }
2140         if (0 == dirty) {
2141                 unsigned long iflags;
2142
2143                 write_lock_irqsave(&sg_index_lock, iflags);
2144                 __sg_remove_sfp(sdp, sfp);
2145                 if (sdp->detached && (NULL == sdp->headfp)) {
2146                         idr_remove(&sg_index_idr, sdp->index);
2147                         kfree(sdp);
2148                         res = 1;
2149                 }
2150                 write_unlock_irqrestore(&sg_index_lock, iflags);
2151         } else {
2152                 /* MOD_INC's to inhibit unloading sg and associated adapter driver */
2153                 /* only bump the access_count if we actually succeeded in
2154                  * throwing another counter on the host module */
2155                 scsi_device_get(sdp->device);   /* XXX: retval ignored? */      
2156                 sfp->closed = 1;        /* flag dirty state on this fd */
2157                 SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2158                                   dirty));
2159         }
2160         return res;
2161 }
2162
2163 static int
2164 sg_res_in_use(Sg_fd * sfp)
2165 {
2166         const Sg_request *srp;
2167         unsigned long iflags;
2168
2169         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2170         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2171                 if (srp->res_used)
2172                         break;
2173         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2174         return srp ? 1 : 0;
2175 }
2176
2177 #ifdef CONFIG_SCSI_PROC_FS
2178 static int
2179 sg_idr_max_id(int id, void *p, void *data)
2180 {
2181         int *k = data;
2182
2183         if (*k < id)
2184                 *k = id;
2185
2186         return 0;
2187 }
2188
2189 static int
2190 sg_last_dev(void)
2191 {
2192         int k = -1;
2193         unsigned long iflags;
2194
2195         read_lock_irqsave(&sg_index_lock, iflags);
2196         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2197         read_unlock_irqrestore(&sg_index_lock, iflags);
2198         return k + 1;           /* origin 1 */
2199 }
2200 #endif
2201
2202 static Sg_device *
2203 sg_get_dev(int dev)
2204 {
2205         Sg_device *sdp;
2206         unsigned long iflags;
2207
2208         read_lock_irqsave(&sg_index_lock, iflags);
2209         sdp = idr_find(&sg_index_idr, dev);
2210         read_unlock_irqrestore(&sg_index_lock, iflags);
2211
2212         return sdp;
2213 }
2214
2215 #ifdef CONFIG_SCSI_PROC_FS
2216
2217 static struct proc_dir_entry *sg_proc_sgp = NULL;
2218
2219 static char sg_proc_sg_dirname[] = "scsi/sg";
2220
2221 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2222
2223 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2224 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2225                                   size_t count, loff_t *off);
2226 static struct file_operations adio_fops = {
2227         /* .owner, .read and .llseek added in sg_proc_init() */
2228         .open = sg_proc_single_open_adio,
2229         .write = sg_proc_write_adio,
2230         .release = single_release,
2231 };
2232
2233 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2234 static ssize_t sg_proc_write_dressz(struct file *filp, 
2235                 const char __user *buffer, size_t count, loff_t *off);
2236 static struct file_operations dressz_fops = {
2237         .open = sg_proc_single_open_dressz,
2238         .write = sg_proc_write_dressz,
2239         .release = single_release,
2240 };
2241
2242 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2243 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2244 static struct file_operations version_fops = {
2245         .open = sg_proc_single_open_version,
2246         .release = single_release,
2247 };
2248
2249 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2250 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2251 static struct file_operations devhdr_fops = {
2252         .open = sg_proc_single_open_devhdr,
2253         .release = single_release,
2254 };
2255
2256 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2257 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2258 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2259 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2260 static void dev_seq_stop(struct seq_file *s, void *v);
2261 static struct file_operations dev_fops = {
2262         .open = sg_proc_open_dev,
2263         .release = seq_release,
2264 };
2265 static struct seq_operations dev_seq_ops = {
2266         .start = dev_seq_start,
2267         .next  = dev_seq_next,
2268         .stop  = dev_seq_stop,
2269         .show  = sg_proc_seq_show_dev,
2270 };
2271
2272 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2273 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2274 static struct file_operations devstrs_fops = {
2275         .open = sg_proc_open_devstrs,
2276         .release = seq_release,
2277 };
2278 static struct seq_operations devstrs_seq_ops = {
2279         .start = dev_seq_start,
2280         .next  = dev_seq_next,
2281         .stop  = dev_seq_stop,
2282         .show  = sg_proc_seq_show_devstrs,
2283 };
2284
2285 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2286 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2287 static struct file_operations debug_fops = {
2288         .open = sg_proc_open_debug,
2289         .release = seq_release,
2290 };
2291 static struct seq_operations debug_seq_ops = {
2292         .start = dev_seq_start,
2293         .next  = dev_seq_next,
2294         .stop  = dev_seq_stop,
2295         .show  = sg_proc_seq_show_debug,
2296 };
2297
2298
2299 struct sg_proc_leaf {
2300         const char * name;
2301         struct file_operations * fops;
2302 };
2303
2304 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2305         {"allow_dio", &adio_fops},
2306         {"debug", &debug_fops},
2307         {"def_reserved_size", &dressz_fops},
2308         {"device_hdr", &devhdr_fops},
2309         {"devices", &dev_fops},
2310         {"device_strs", &devstrs_fops},
2311         {"version", &version_fops}
2312 };
2313
2314 static int
2315 sg_proc_init(void)
2316 {
2317         int k, mask;
2318         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2319         struct sg_proc_leaf * leaf;
2320
2321         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2322         if (!sg_proc_sgp)
2323                 return 1;
2324         for (k = 0; k < num_leaves; ++k) {
2325                 leaf = &sg_proc_leaf_arr[k];
2326                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2327                 leaf->fops->owner = THIS_MODULE;
2328                 leaf->fops->read = seq_read;
2329                 leaf->fops->llseek = seq_lseek;
2330                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2331         }
2332         return 0;
2333 }
2334
2335 static void
2336 sg_proc_cleanup(void)
2337 {
2338         int k;
2339         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2340
2341         if (!sg_proc_sgp)
2342                 return;
2343         for (k = 0; k < num_leaves; ++k)
2344                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2345         remove_proc_entry(sg_proc_sg_dirname, NULL);
2346 }
2347
2348
2349 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2350 {
2351         seq_printf(s, "%d\n", *((int *)s->private));
2352         return 0;
2353 }
2354
2355 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2356 {
2357         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2358 }
2359
2360 static ssize_t 
2361 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2362                    size_t count, loff_t *off)
2363 {
2364         int num;
2365         char buff[11];
2366
2367         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2368                 return -EACCES;
2369         num = (count < 10) ? count : 10;
2370         if (copy_from_user(buff, buffer, num))
2371                 return -EFAULT;
2372         buff[num] = '\0';
2373         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2374         return count;
2375 }
2376
2377 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2378 {
2379         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2380 }
2381
2382 static ssize_t 
2383 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2384                      size_t count, loff_t *off)
2385 {
2386         int num;
2387         unsigned long k = ULONG_MAX;
2388         char buff[11];
2389
2390         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2391                 return -EACCES;
2392         num = (count < 10) ? count : 10;
2393         if (copy_from_user(buff, buffer, num))
2394                 return -EFAULT;
2395         buff[num] = '\0';
2396         k = simple_strtoul(buff, NULL, 10);
2397         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2398                 sg_big_buff = k;
2399                 return count;
2400         }
2401         return -ERANGE;
2402 }
2403
2404 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2405 {
2406         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2407                    sg_version_date);
2408         return 0;
2409 }
2410
2411 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2412 {
2413         return single_open(file, sg_proc_seq_show_version, NULL);
2414 }
2415
2416 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2417 {
2418         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2419                    "online\n");
2420         return 0;
2421 }
2422
2423 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2424 {
2425         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2426 }
2427
2428 struct sg_proc_deviter {
2429         loff_t  index;
2430         size_t  max;
2431 };
2432
2433 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2434 {
2435         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2436
2437         s->private = it;
2438         if (! it)
2439                 return NULL;
2440
2441         it->index = *pos;
2442         it->max = sg_last_dev();
2443         if (it->index >= it->max)
2444                 return NULL;
2445         return it;
2446 }
2447
2448 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2449 {
2450         struct sg_proc_deviter * it = s->private;
2451
2452         *pos = ++it->index;
2453         return (it->index < it->max) ? it : NULL;
2454 }
2455
2456 static void dev_seq_stop(struct seq_file *s, void *v)
2457 {
2458         kfree(s->private);
2459 }
2460
2461 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2462 {
2463         return seq_open(file, &dev_seq_ops);
2464 }
2465
2466 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2467 {
2468         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2469         Sg_device *sdp;
2470         struct scsi_device *scsidp;
2471
2472         sdp = it ? sg_get_dev(it->index) : NULL;
2473         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2474                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2475                               scsidp->host->host_no, scsidp->channel,
2476                               scsidp->id, scsidp->lun, (int) scsidp->type,
2477                               1,
2478                               (int) scsidp->queue_depth,
2479                               (int) scsidp->device_busy,
2480                               (int) scsi_device_online(scsidp));
2481         else
2482                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2483         return 0;
2484 }
2485
2486 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2487 {
2488         return seq_open(file, &devstrs_seq_ops);
2489 }
2490
2491 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2492 {
2493         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2494         Sg_device *sdp;
2495         struct scsi_device *scsidp;
2496
2497         sdp = it ? sg_get_dev(it->index) : NULL;
2498         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2499                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2500                            scsidp->vendor, scsidp->model, scsidp->rev);
2501         else
2502                 seq_printf(s, "<no active device>\n");
2503         return 0;
2504 }
2505
2506 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2507 {
2508         int k, m, new_interface, blen, usg;
2509         Sg_request *srp;
2510         Sg_fd *fp;
2511         const sg_io_hdr_t *hp;
2512         const char * cp;
2513         unsigned int ms;
2514
2515         for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
2516                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2517                            "(res)sgat=%d low_dma=%d\n", k + 1,
2518                            jiffies_to_msecs(fp->timeout),
2519                            fp->reserve.bufflen,
2520                            (int) fp->reserve.k_use_sg,
2521                            (int) fp->low_dma);
2522                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2523                            (int) fp->cmd_q, (int) fp->force_packid,
2524                            (int) fp->keep_orphan, (int) fp->closed);
2525                 for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
2526                         hp = &srp->header;
2527                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2528                         if (srp->res_used) {
2529                                 if (new_interface && 
2530                                     (SG_FLAG_MMAP_IO & hp->flags))
2531                                         cp = "     mmap>> ";
2532                                 else
2533                                         cp = "     rb>> ";
2534                         } else {
2535                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2536                                         cp = "     dio>> ";
2537                                 else
2538                                         cp = "     ";
2539                         }
2540                         seq_printf(s, cp);
2541                         blen = srp->data.bufflen;
2542                         usg = srp->data.k_use_sg;
2543                         seq_printf(s, srp->done ? 
2544                                    ((1 == srp->done) ?  "rcv:" : "fin:")
2545                                    : "act:");
2546                         seq_printf(s, " id=%d blen=%d",
2547                                    srp->header.pack_id, blen);
2548                         if (srp->done)
2549                                 seq_printf(s, " dur=%d", hp->duration);
2550                         else {
2551                                 ms = jiffies_to_msecs(jiffies);
2552                                 seq_printf(s, " t_o/elap=%d/%d",
2553                                         (new_interface ? hp->timeout :
2554                                                   jiffies_to_msecs(fp->timeout)),
2555                                         (ms > hp->duration ? ms - hp->duration : 0));
2556                         }
2557                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2558                                    (int) srp->data.cmd_opcode);
2559                 }
2560                 if (0 == m)
2561                         seq_printf(s, "     No requests active\n");
2562         }
2563 }
2564
2565 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2566 {
2567         return seq_open(file, &debug_seq_ops);
2568 }
2569
2570 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2571 {
2572         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2573         Sg_device *sdp;
2574
2575         if (it && (0 == it->index)) {
2576                 seq_printf(s, "max_active_device=%d(origin 1)\n",
2577                            (int)it->max);
2578                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2579         }
2580         sdp = it ? sg_get_dev(it->index) : NULL;
2581         if (sdp) {
2582                 struct scsi_device *scsidp = sdp->device;
2583
2584                 if (NULL == scsidp) {
2585                         seq_printf(s, "device %d detached ??\n", 
2586                                    (int)it->index);
2587                         return 0;
2588                 }
2589
2590                 if (sg_get_nth_sfp(sdp, 0)) {
2591                         seq_printf(s, " >>> device=%s ",
2592                                 sdp->disk->disk_name);
2593                         if (sdp->detached)
2594                                 seq_printf(s, "detached pending close ");
2595                         else
2596                                 seq_printf
2597                                     (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2598                                      scsidp->host->host_no,
2599                                      scsidp->channel, scsidp->id,
2600                                      scsidp->lun,
2601                                      scsidp->host->hostt->emulated);
2602                         seq_printf(s, " sg_tablesize=%d excl=%d\n",
2603                                    sdp->sg_tablesize, sdp->exclude);
2604                 }
2605                 sg_proc_debug_helper(s, sdp);
2606         }
2607         return 0;
2608 }
2609
2610 #endif                          /* CONFIG_SCSI_PROC_FS */
2611
2612 module_init(init_sg);
2613 module_exit(exit_sg);