[SCSI] fcoe: fix fcoe module ref counting
[linux-2.6.git] / drivers / scsi / sg.c
1 /*
2  *  History:
3  *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
4  *           to allow user process control of SCSI devices.
5  *  Development Sponsored by Killy Corp. NY NY
6  *
7  * Original driver (sg.c):
8  *        Copyright (C) 1992 Lawrence Foard
9  * Version 2 and 3 extensions to driver:
10  *        Copyright (C) 1998 - 2005 Douglas Gilbert
11  *
12  *  Modified  19-JAN-1998  Richard Gooch <rgooch@atnf.csiro.au>  Devfs support
13  *
14  * This program is free software; you can redistribute it and/or modify
15  * it under the terms of the GNU General Public License as published by
16  * the Free Software Foundation; either version 2, or (at your option)
17  * any later version.
18  *
19  */
20
21 static int sg_version_num = 30534;      /* 2 digits for each component */
22 #define SG_VERSION_STR "3.5.34"
23
24 /*
25  *  D. P. Gilbert (dgilbert@interlog.com, dougg@triode.net.au), notes:
26  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
27  *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
28  *        (otherwise the macros compile to empty statements).
29  *
30  */
31 #include <linux/module.h>
32
33 #include <linux/fs.h>
34 #include <linux/kernel.h>
35 #include <linux/sched.h>
36 #include <linux/string.h>
37 #include <linux/mm.h>
38 #include <linux/errno.h>
39 #include <linux/mtio.h>
40 #include <linux/ioctl.h>
41 #include <linux/slab.h>
42 #include <linux/fcntl.h>
43 #include <linux/init.h>
44 #include <linux/poll.h>
45 #include <linux/moduleparam.h>
46 #include <linux/cdev.h>
47 #include <linux/idr.h>
48 #include <linux/seq_file.h>
49 #include <linux/blkdev.h>
50 #include <linux/delay.h>
51 #include <linux/blktrace_api.h>
52 #include <linux/smp_lock.h>
53
54 #include "scsi.h"
55 #include <scsi/scsi_dbg.h>
56 #include <scsi/scsi_host.h>
57 #include <scsi/scsi_driver.h>
58 #include <scsi/scsi_ioctl.h>
59 #include <scsi/sg.h>
60
61 #include "scsi_logging.h"
62
63 #ifdef CONFIG_SCSI_PROC_FS
64 #include <linux/proc_fs.h>
65 static char *sg_version_date = "20061027";
66
67 static int sg_proc_init(void);
68 static void sg_proc_cleanup(void);
69 #endif
70
71 #define SG_ALLOW_DIO_DEF 0
72
73 #define SG_MAX_DEVS 32768
74
75 /*
76  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
77  * Then when using 32 bit integers x * m may overflow during the calculation.
78  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
79  * calculates the same, but prevents the overflow when both m and d
80  * are "small" numbers (like HZ and USER_HZ).
81  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
82  * in 32 bits.
83  */
84 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
85
86 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
87
88 int sg_big_buff = SG_DEF_RESERVED_SIZE;
89 /* N.B. This variable is readable and writeable via
90    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
91    of this size (or less if there is not enough memory) will be reserved
92    for use by this file descriptor. [Deprecated usage: this variable is also
93    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
94    the kernel (i.e. it is not a module).] */
95 static int def_reserved_size = -1;      /* picks up init parameter */
96 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
97
98 static int scatter_elem_sz = SG_SCATTER_SZ;
99 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
100
101 #define SG_SECTOR_SZ 512
102
103 static int sg_add(struct device *, struct class_interface *);
104 static void sg_remove(struct device *, struct class_interface *);
105
106 static DEFINE_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         struct execute_work ew;
141 } Sg_request;
142
143 typedef struct sg_fd {          /* holds the state of a file descriptor */
144         struct list_head sfd_siblings;
145         struct sg_device *parentdp;     /* owning device */
146         wait_queue_head_t read_wait;    /* queue read until command done */
147         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
148         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
149         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
150         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
151         unsigned save_scat_len; /* original length of trunc. scat. element */
152         Sg_request *headrp;     /* head of request slist, NULL->empty */
153         struct fasync_struct *async_qp; /* used by asynchronous notification */
154         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
155         char low_dma;           /* as in parent but possibly overridden to 1 */
156         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
157         volatile char closed;   /* 1 -> fd closed but request(s) outstanding */
158         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
159         char next_cmd_len;      /* 0 -> automatic (def), >0 -> use on next write() */
160         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
161         char mmap_called;       /* 0 -> mmap() never called on this fd */
162         struct kref f_ref;
163         struct execute_work ew;
164 } Sg_fd;
165
166 typedef struct sg_device { /* holds the state of each scsi generic device */
167         struct scsi_device *device;
168         wait_queue_head_t o_excl_wait;  /* queue open() when O_EXCL in use */
169         int sg_tablesize;       /* adapter's max scatter-gather table size */
170         u32 index;              /* device index number */
171         struct list_head sfds;
172         volatile char detached; /* 0->attached, 1->detached pending removal */
173         volatile char exclude;  /* opened for exclusive access */
174         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
175         struct gendisk *disk;
176         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
177         struct kref d_ref;
178 } Sg_device;
179
180 /* tasklet or soft irq callback */
181 static void sg_rq_end_io(struct request *rq, int uptodate);
182 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
183 static int sg_finish_rem_req(Sg_request * srp);
184 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
185 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
186                            Sg_request * srp);
187 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
188                         const char __user *buf, size_t count, int blocking,
189                         int read_only, int sg_io_owned, Sg_request **o_srp);
190 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
191                            unsigned char *cmnd, int timeout, int blocking);
192 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
193 static void sg_remove_scat(Sg_scatter_hold * schp);
194 static void sg_build_reserve(Sg_fd * sfp, int req_size);
195 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
196 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
197 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
198 static void sg_remove_sfp(struct kref *);
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 static void sg_put_dev(Sg_device *sdp);
205
206 #define SZ_SG_HEADER sizeof(struct sg_header)
207 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
208 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
209 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
210
211 static int sg_allow_access(struct file *filp, unsigned char *cmd)
212 {
213         struct sg_fd *sfp = (struct sg_fd *)filp->private_data;
214
215         if (sfp->parentdp->device->type == TYPE_SCANNER)
216                 return 0;
217
218         return blk_verify_command(cmd, filp->f_mode & FMODE_WRITE);
219 }
220
221 static int
222 sg_open(struct inode *inode, struct file *filp)
223 {
224         int dev = iminor(inode);
225         int flags = filp->f_flags;
226         struct request_queue *q;
227         Sg_device *sdp;
228         Sg_fd *sfp;
229         int res;
230         int retval;
231
232         lock_kernel();
233         nonseekable_open(inode, filp);
234         SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
235         sdp = sg_get_dev(dev);
236         if (IS_ERR(sdp)) {
237                 retval = PTR_ERR(sdp);
238                 sdp = NULL;
239                 goto sg_put;
240         }
241
242         /* This driver's module count bumped by fops_get in <linux/fs.h> */
243         /* Prevent the device driver from vanishing while we sleep */
244         retval = scsi_device_get(sdp->device);
245         if (retval)
246                 goto sg_put;
247
248         if (!((flags & O_NONBLOCK) ||
249               scsi_block_when_processing_errors(sdp->device))) {
250                 retval = -ENXIO;
251                 /* we are in error recovery for this device */
252                 goto error_out;
253         }
254
255         if (flags & O_EXCL) {
256                 if (O_RDONLY == (flags & O_ACCMODE)) {
257                         retval = -EPERM; /* Can't lock it with read only access */
258                         goto error_out;
259                 }
260                 if (!list_empty(&sdp->sfds) && (flags & O_NONBLOCK)) {
261                         retval = -EBUSY;
262                         goto error_out;
263                 }
264                 res = 0;
265                 __wait_event_interruptible(sdp->o_excl_wait,
266                                            ((!list_empty(&sdp->sfds) || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
267                 if (res) {
268                         retval = res;   /* -ERESTARTSYS because signal hit process */
269                         goto error_out;
270                 }
271         } else if (sdp->exclude) {      /* some other fd has an exclusive lock on dev */
272                 if (flags & O_NONBLOCK) {
273                         retval = -EBUSY;
274                         goto error_out;
275                 }
276                 res = 0;
277                 __wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
278                                            res);
279                 if (res) {
280                         retval = res;   /* -ERESTARTSYS because signal hit process */
281                         goto error_out;
282                 }
283         }
284         if (sdp->detached) {
285                 retval = -ENODEV;
286                 goto error_out;
287         }
288         if (list_empty(&sdp->sfds)) {   /* no existing opens on this device */
289                 sdp->sgdebug = 0;
290                 q = sdp->device->request_queue;
291                 sdp->sg_tablesize = queue_max_segments(q);
292         }
293         if ((sfp = sg_add_sfp(sdp, dev)))
294                 filp->private_data = sfp;
295         else {
296                 if (flags & O_EXCL) {
297                         sdp->exclude = 0;       /* undo if error */
298                         wake_up_interruptible(&sdp->o_excl_wait);
299                 }
300                 retval = -ENOMEM;
301                 goto error_out;
302         }
303         retval = 0;
304 error_out:
305         if (retval)
306                 scsi_device_put(sdp->device);
307 sg_put:
308         if (sdp)
309                 sg_put_dev(sdp);
310         unlock_kernel();
311         return retval;
312 }
313
314 /* Following function was formerly called 'sg_close' */
315 static int
316 sg_release(struct inode *inode, struct file *filp)
317 {
318         Sg_device *sdp;
319         Sg_fd *sfp;
320
321         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
322                 return -ENXIO;
323         SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
324
325         sfp->closed = 1;
326
327         sdp->exclude = 0;
328         wake_up_interruptible(&sdp->o_excl_wait);
329
330         kref_put(&sfp->f_ref, sg_remove_sfp);
331         return 0;
332 }
333
334 static ssize_t
335 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
336 {
337         Sg_device *sdp;
338         Sg_fd *sfp;
339         Sg_request *srp;
340         int req_pack_id = -1;
341         sg_io_hdr_t *hp;
342         struct sg_header *old_hdr = NULL;
343         int retval = 0;
344
345         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
346                 return -ENXIO;
347         SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
348                                    sdp->disk->disk_name, (int) count));
349
350         if (!access_ok(VERIFY_WRITE, buf, count))
351                 return -EFAULT;
352         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
353                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
354                 if (!old_hdr)
355                         return -ENOMEM;
356                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
357                         retval = -EFAULT;
358                         goto free_old_hdr;
359                 }
360                 if (old_hdr->reply_len < 0) {
361                         if (count >= SZ_SG_IO_HDR) {
362                                 sg_io_hdr_t *new_hdr;
363                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
364                                 if (!new_hdr) {
365                                         retval = -ENOMEM;
366                                         goto free_old_hdr;
367                                 }
368                                 retval =__copy_from_user
369                                     (new_hdr, buf, SZ_SG_IO_HDR);
370                                 req_pack_id = new_hdr->pack_id;
371                                 kfree(new_hdr);
372                                 if (retval) {
373                                         retval = -EFAULT;
374                                         goto free_old_hdr;
375                                 }
376                         }
377                 } else
378                         req_pack_id = old_hdr->pack_id;
379         }
380         srp = sg_get_rq_mark(sfp, req_pack_id);
381         if (!srp) {             /* now wait on packet to arrive */
382                 if (sdp->detached) {
383                         retval = -ENODEV;
384                         goto free_old_hdr;
385                 }
386                 if (filp->f_flags & O_NONBLOCK) {
387                         retval = -EAGAIN;
388                         goto free_old_hdr;
389                 }
390                 while (1) {
391                         retval = 0; /* following macro beats race condition */
392                         __wait_event_interruptible(sfp->read_wait,
393                                 (sdp->detached ||
394                                 (srp = sg_get_rq_mark(sfp, req_pack_id))), 
395                                 retval);
396                         if (sdp->detached) {
397                                 retval = -ENODEV;
398                                 goto free_old_hdr;
399                         }
400                         if (0 == retval)
401                                 break;
402
403                         /* -ERESTARTSYS as signal hit process */
404                         goto free_old_hdr;
405                 }
406         }
407         if (srp->header.interface_id != '\0') {
408                 retval = sg_new_read(sfp, buf, count, srp);
409                 goto free_old_hdr;
410         }
411
412         hp = &srp->header;
413         if (old_hdr == NULL) {
414                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
415                 if (! old_hdr) {
416                         retval = -ENOMEM;
417                         goto free_old_hdr;
418                 }
419         }
420         memset(old_hdr, 0, SZ_SG_HEADER);
421         old_hdr->reply_len = (int) hp->timeout;
422         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
423         old_hdr->pack_id = hp->pack_id;
424         old_hdr->twelve_byte =
425             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
426         old_hdr->target_status = hp->masked_status;
427         old_hdr->host_status = hp->host_status;
428         old_hdr->driver_status = hp->driver_status;
429         if ((CHECK_CONDITION & hp->masked_status) ||
430             (DRIVER_SENSE & hp->driver_status))
431                 memcpy(old_hdr->sense_buffer, srp->sense_b,
432                        sizeof (old_hdr->sense_buffer));
433         switch (hp->host_status) {
434         /* This setup of 'result' is for backward compatibility and is best
435            ignored by the user who should use target, host + driver status */
436         case DID_OK:
437         case DID_PASSTHROUGH:
438         case DID_SOFT_ERROR:
439                 old_hdr->result = 0;
440                 break;
441         case DID_NO_CONNECT:
442         case DID_BUS_BUSY:
443         case DID_TIME_OUT:
444                 old_hdr->result = EBUSY;
445                 break;
446         case DID_BAD_TARGET:
447         case DID_ABORT:
448         case DID_PARITY:
449         case DID_RESET:
450         case DID_BAD_INTR:
451                 old_hdr->result = EIO;
452                 break;
453         case DID_ERROR:
454                 old_hdr->result = (srp->sense_b[0] == 0 && 
455                                   hp->masked_status == GOOD) ? 0 : EIO;
456                 break;
457         default:
458                 old_hdr->result = EIO;
459                 break;
460         }
461
462         /* Now copy the result back to the user buffer.  */
463         if (count >= SZ_SG_HEADER) {
464                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
465                         retval = -EFAULT;
466                         goto free_old_hdr;
467                 }
468                 buf += SZ_SG_HEADER;
469                 if (count > old_hdr->reply_len)
470                         count = old_hdr->reply_len;
471                 if (count > SZ_SG_HEADER) {
472                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
473                                 retval = -EFAULT;
474                                 goto free_old_hdr;
475                         }
476                 }
477         } else
478                 count = (old_hdr->result == 0) ? 0 : -EIO;
479         sg_finish_rem_req(srp);
480         retval = count;
481 free_old_hdr:
482         kfree(old_hdr);
483         return retval;
484 }
485
486 static ssize_t
487 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
488 {
489         sg_io_hdr_t *hp = &srp->header;
490         int err = 0;
491         int len;
492
493         if (count < SZ_SG_IO_HDR) {
494                 err = -EINVAL;
495                 goto err_out;
496         }
497         hp->sb_len_wr = 0;
498         if ((hp->mx_sb_len > 0) && hp->sbp) {
499                 if ((CHECK_CONDITION & hp->masked_status) ||
500                     (DRIVER_SENSE & hp->driver_status)) {
501                         int sb_len = SCSI_SENSE_BUFFERSIZE;
502                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
503                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
504                         len = (len > sb_len) ? sb_len : len;
505                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
506                                 err = -EFAULT;
507                                 goto err_out;
508                         }
509                         hp->sb_len_wr = len;
510                 }
511         }
512         if (hp->masked_status || hp->host_status || hp->driver_status)
513                 hp->info |= SG_INFO_CHECK;
514         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
515                 err = -EFAULT;
516                 goto err_out;
517         }
518 err_out:
519         err = sg_finish_rem_req(srp);
520         return (0 == err) ? count : err;
521 }
522
523 static ssize_t
524 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
525 {
526         int mxsize, cmd_size, k;
527         int input_size, blocking;
528         unsigned char opcode;
529         Sg_device *sdp;
530         Sg_fd *sfp;
531         Sg_request *srp;
532         struct sg_header old_hdr;
533         sg_io_hdr_t *hp;
534         unsigned char cmnd[MAX_COMMAND_SIZE];
535
536         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
537                 return -ENXIO;
538         SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
539                                    sdp->disk->disk_name, (int) count));
540         if (sdp->detached)
541                 return -ENODEV;
542         if (!((filp->f_flags & O_NONBLOCK) ||
543               scsi_block_when_processing_errors(sdp->device)))
544                 return -ENXIO;
545
546         if (!access_ok(VERIFY_READ, buf, count))
547                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
548         if (count < SZ_SG_HEADER)
549                 return -EIO;
550         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
551                 return -EFAULT;
552         blocking = !(filp->f_flags & O_NONBLOCK);
553         if (old_hdr.reply_len < 0)
554                 return sg_new_write(sfp, filp, buf, count,
555                                     blocking, 0, 0, NULL);
556         if (count < (SZ_SG_HEADER + 6))
557                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
558
559         if (!(srp = sg_add_request(sfp))) {
560                 SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
561                 return -EDOM;
562         }
563         buf += SZ_SG_HEADER;
564         __get_user(opcode, buf);
565         if (sfp->next_cmd_len > 0) {
566                 if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
567                         SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
568                         sfp->next_cmd_len = 0;
569                         sg_remove_request(sfp, srp);
570                         return -EIO;
571                 }
572                 cmd_size = sfp->next_cmd_len;
573                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
574         } else {
575                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
576                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
577                         cmd_size = 12;
578         }
579         SCSI_LOG_TIMEOUT(4, printk(
580                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
581 /* Determine buffer size.  */
582         input_size = count - cmd_size;
583         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
584         mxsize -= SZ_SG_HEADER;
585         input_size -= SZ_SG_HEADER;
586         if (input_size < 0) {
587                 sg_remove_request(sfp, srp);
588                 return -EIO;    /* User did not pass enough bytes for this command. */
589         }
590         hp = &srp->header;
591         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
592         hp->cmd_len = (unsigned char) cmd_size;
593         hp->iovec_count = 0;
594         hp->mx_sb_len = 0;
595         if (input_size > 0)
596                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
597                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
598         else
599                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
600         hp->dxfer_len = mxsize;
601         if (hp->dxfer_direction == SG_DXFER_TO_DEV)
602                 hp->dxferp = (char __user *)buf + cmd_size;
603         else
604                 hp->dxferp = NULL;
605         hp->sbp = NULL;
606         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
607         hp->flags = input_size; /* structure abuse ... */
608         hp->pack_id = old_hdr.pack_id;
609         hp->usr_ptr = NULL;
610         if (__copy_from_user(cmnd, buf, cmd_size))
611                 return -EFAULT;
612         /*
613          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
614          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
615          * is a non-zero input_size, so emit a warning.
616          */
617         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
618                 static char cmd[TASK_COMM_LEN];
619                 if (strcmp(current->comm, cmd) && printk_ratelimit()) {
620                         printk(KERN_WARNING
621                                "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
622                                "guessing data in;\n   "
623                                "program %s not setting count and/or reply_len properly\n",
624                                old_hdr.reply_len - (int)SZ_SG_HEADER,
625                                input_size, (unsigned int) cmnd[0],
626                                current->comm);
627                         strcpy(cmd, current->comm);
628                 }
629         }
630         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
631         return (k < 0) ? k : count;
632 }
633
634 static ssize_t
635 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
636                  size_t count, int blocking, int read_only, int sg_io_owned,
637                  Sg_request **o_srp)
638 {
639         int k;
640         Sg_request *srp;
641         sg_io_hdr_t *hp;
642         unsigned char cmnd[MAX_COMMAND_SIZE];
643         int timeout;
644         unsigned long ul_timeout;
645
646         if (count < SZ_SG_IO_HDR)
647                 return -EINVAL;
648         if (!access_ok(VERIFY_READ, buf, count))
649                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
650
651         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
652         if (!(srp = sg_add_request(sfp))) {
653                 SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
654                 return -EDOM;
655         }
656         srp->sg_io_owned = sg_io_owned;
657         hp = &srp->header;
658         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
659                 sg_remove_request(sfp, srp);
660                 return -EFAULT;
661         }
662         if (hp->interface_id != 'S') {
663                 sg_remove_request(sfp, srp);
664                 return -ENOSYS;
665         }
666         if (hp->flags & SG_FLAG_MMAP_IO) {
667                 if (hp->dxfer_len > sfp->reserve.bufflen) {
668                         sg_remove_request(sfp, srp);
669                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
670                 }
671                 if (hp->flags & SG_FLAG_DIRECT_IO) {
672                         sg_remove_request(sfp, srp);
673                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
674                 }
675                 if (sg_res_in_use(sfp)) {
676                         sg_remove_request(sfp, srp);
677                         return -EBUSY;  /* reserve buffer already being used */
678                 }
679         }
680         ul_timeout = msecs_to_jiffies(srp->header.timeout);
681         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
682         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
683                 sg_remove_request(sfp, srp);
684                 return -EMSGSIZE;
685         }
686         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
687                 sg_remove_request(sfp, srp);
688                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
689         }
690         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
691                 sg_remove_request(sfp, srp);
692                 return -EFAULT;
693         }
694         if (read_only && sg_allow_access(file, cmnd)) {
695                 sg_remove_request(sfp, srp);
696                 return -EPERM;
697         }
698         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
699         if (k < 0)
700                 return k;
701         if (o_srp)
702                 *o_srp = srp;
703         return count;
704 }
705
706 static int
707 sg_common_write(Sg_fd * sfp, Sg_request * srp,
708                 unsigned char *cmnd, int timeout, int blocking)
709 {
710         int k, data_dir;
711         Sg_device *sdp = sfp->parentdp;
712         sg_io_hdr_t *hp = &srp->header;
713
714         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
715         hp->status = 0;
716         hp->masked_status = 0;
717         hp->msg_status = 0;
718         hp->info = 0;
719         hp->host_status = 0;
720         hp->driver_status = 0;
721         hp->resid = 0;
722         SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
723                           (int) cmnd[0], (int) hp->cmd_len));
724
725         k = sg_start_req(srp, cmnd);
726         if (k) {
727                 SCSI_LOG_TIMEOUT(1, printk("sg_common_write: start_req err=%d\n", k));
728                 sg_finish_rem_req(srp);
729                 return k;       /* probably out of space --> ENOMEM */
730         }
731         if (sdp->detached) {
732                 sg_finish_rem_req(srp);
733                 return -ENODEV;
734         }
735
736         switch (hp->dxfer_direction) {
737         case SG_DXFER_TO_FROM_DEV:
738         case SG_DXFER_FROM_DEV:
739                 data_dir = DMA_FROM_DEVICE;
740                 break;
741         case SG_DXFER_TO_DEV:
742                 data_dir = DMA_TO_DEVICE;
743                 break;
744         case SG_DXFER_UNKNOWN:
745                 data_dir = DMA_BIDIRECTIONAL;
746                 break;
747         default:
748                 data_dir = DMA_NONE;
749                 break;
750         }
751         hp->duration = jiffies_to_msecs(jiffies);
752
753         srp->rq->timeout = timeout;
754         kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
755         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
756                               srp->rq, 1, sg_rq_end_io);
757         return 0;
758 }
759
760 static int
761 sg_ioctl(struct inode *inode, struct file *filp,
762          unsigned int cmd_in, unsigned long arg)
763 {
764         void __user *p = (void __user *)arg;
765         int __user *ip = p;
766         int result, val, read_only;
767         Sg_device *sdp;
768         Sg_fd *sfp;
769         Sg_request *srp;
770         unsigned long iflags;
771
772         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
773                 return -ENXIO;
774
775         SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
776                                    sdp->disk->disk_name, (int) cmd_in));
777         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
778
779         switch (cmd_in) {
780         case SG_IO:
781                 {
782                         int blocking = 1;       /* ignore O_NONBLOCK flag */
783
784                         if (sdp->detached)
785                                 return -ENODEV;
786                         if (!scsi_block_when_processing_errors(sdp->device))
787                                 return -ENXIO;
788                         if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
789                                 return -EFAULT;
790                         result =
791                             sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
792                                          blocking, read_only, 1, &srp);
793                         if (result < 0)
794                                 return result;
795                         while (1) {
796                                 result = 0;     /* following macro to beat race condition */
797                                 __wait_event_interruptible(sfp->read_wait,
798                                         (srp->done || sdp->detached),
799                                         result);
800                                 if (sdp->detached)
801                                         return -ENODEV;
802                                 write_lock_irq(&sfp->rq_list_lock);
803                                 if (srp->done) {
804                                         srp->done = 2;
805                                         write_unlock_irq(&sfp->rq_list_lock);
806                                         break;
807                                 }
808                                 srp->orphan = 1;
809                                 write_unlock_irq(&sfp->rq_list_lock);
810                                 return result;  /* -ERESTARTSYS because signal hit process */
811                         }
812                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
813                         return (result < 0) ? result : 0;
814                 }
815         case SG_SET_TIMEOUT:
816                 result = get_user(val, ip);
817                 if (result)
818                         return result;
819                 if (val < 0)
820                         return -EIO;
821                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
822                     val = MULDIV (INT_MAX, USER_HZ, HZ);
823                 sfp->timeout_user = val;
824                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
825
826                 return 0;
827         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
828                                 /* strange ..., for backward compatibility */
829                 return sfp->timeout_user;
830         case SG_SET_FORCE_LOW_DMA:
831                 result = get_user(val, ip);
832                 if (result)
833                         return result;
834                 if (val) {
835                         sfp->low_dma = 1;
836                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
837                                 val = (int) sfp->reserve.bufflen;
838                                 sg_remove_scat(&sfp->reserve);
839                                 sg_build_reserve(sfp, val);
840                         }
841                 } else {
842                         if (sdp->detached)
843                                 return -ENODEV;
844                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
845                 }
846                 return 0;
847         case SG_GET_LOW_DMA:
848                 return put_user((int) sfp->low_dma, ip);
849         case SG_GET_SCSI_ID:
850                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
851                         return -EFAULT;
852                 else {
853                         sg_scsi_id_t __user *sg_idp = p;
854
855                         if (sdp->detached)
856                                 return -ENODEV;
857                         __put_user((int) sdp->device->host->host_no,
858                                    &sg_idp->host_no);
859                         __put_user((int) sdp->device->channel,
860                                    &sg_idp->channel);
861                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
862                         __put_user((int) sdp->device->lun, &sg_idp->lun);
863                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
864                         __put_user((short) sdp->device->host->cmd_per_lun,
865                                    &sg_idp->h_cmd_per_lun);
866                         __put_user((short) sdp->device->queue_depth,
867                                    &sg_idp->d_queue_depth);
868                         __put_user(0, &sg_idp->unused[0]);
869                         __put_user(0, &sg_idp->unused[1]);
870                         return 0;
871                 }
872         case SG_SET_FORCE_PACK_ID:
873                 result = get_user(val, ip);
874                 if (result)
875                         return result;
876                 sfp->force_packid = val ? 1 : 0;
877                 return 0;
878         case SG_GET_PACK_ID:
879                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
880                         return -EFAULT;
881                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
882                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
883                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
884                                 read_unlock_irqrestore(&sfp->rq_list_lock,
885                                                        iflags);
886                                 __put_user(srp->header.pack_id, ip);
887                                 return 0;
888                         }
889                 }
890                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
891                 __put_user(-1, ip);
892                 return 0;
893         case SG_GET_NUM_WAITING:
894                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
895                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
896                         if ((1 == srp->done) && (!srp->sg_io_owned))
897                                 ++val;
898                 }
899                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
900                 return put_user(val, ip);
901         case SG_GET_SG_TABLESIZE:
902                 return put_user(sdp->sg_tablesize, ip);
903         case SG_SET_RESERVED_SIZE:
904                 result = get_user(val, ip);
905                 if (result)
906                         return result;
907                 if (val < 0)
908                         return -EINVAL;
909                 val = min_t(int, val,
910                             queue_max_sectors(sdp->device->request_queue) * 512);
911                 if (val != sfp->reserve.bufflen) {
912                         if (sg_res_in_use(sfp) || sfp->mmap_called)
913                                 return -EBUSY;
914                         sg_remove_scat(&sfp->reserve);
915                         sg_build_reserve(sfp, val);
916                 }
917                 return 0;
918         case SG_GET_RESERVED_SIZE:
919                 val = min_t(int, sfp->reserve.bufflen,
920                             queue_max_sectors(sdp->device->request_queue) * 512);
921                 return put_user(val, ip);
922         case SG_SET_COMMAND_Q:
923                 result = get_user(val, ip);
924                 if (result)
925                         return result;
926                 sfp->cmd_q = val ? 1 : 0;
927                 return 0;
928         case SG_GET_COMMAND_Q:
929                 return put_user((int) sfp->cmd_q, ip);
930         case SG_SET_KEEP_ORPHAN:
931                 result = get_user(val, ip);
932                 if (result)
933                         return result;
934                 sfp->keep_orphan = val;
935                 return 0;
936         case SG_GET_KEEP_ORPHAN:
937                 return put_user((int) sfp->keep_orphan, ip);
938         case SG_NEXT_CMD_LEN:
939                 result = get_user(val, ip);
940                 if (result)
941                         return result;
942                 sfp->next_cmd_len = (val > 0) ? val : 0;
943                 return 0;
944         case SG_GET_VERSION_NUM:
945                 return put_user(sg_version_num, ip);
946         case SG_GET_ACCESS_COUNT:
947                 /* faked - we don't have a real access count anymore */
948                 val = (sdp->device ? 1 : 0);
949                 return put_user(val, ip);
950         case SG_GET_REQUEST_TABLE:
951                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
952                         return -EFAULT;
953                 else {
954                         sg_req_info_t *rinfo;
955                         unsigned int ms;
956
957                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
958                                                                 GFP_KERNEL);
959                         if (!rinfo)
960                                 return -ENOMEM;
961                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
962                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
963                              ++val, srp = srp ? srp->nextrp : srp) {
964                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
965                                 if (srp) {
966                                         rinfo[val].req_state = srp->done + 1;
967                                         rinfo[val].problem =
968                                             srp->header.masked_status & 
969                                             srp->header.host_status & 
970                                             srp->header.driver_status;
971                                         if (srp->done)
972                                                 rinfo[val].duration =
973                                                         srp->header.duration;
974                                         else {
975                                                 ms = jiffies_to_msecs(jiffies);
976                                                 rinfo[val].duration =
977                                                     (ms > srp->header.duration) ?
978                                                     (ms - srp->header.duration) : 0;
979                                         }
980                                         rinfo[val].orphan = srp->orphan;
981                                         rinfo[val].sg_io_owned =
982                                                         srp->sg_io_owned;
983                                         rinfo[val].pack_id =
984                                                         srp->header.pack_id;
985                                         rinfo[val].usr_ptr =
986                                                         srp->header.usr_ptr;
987                                 }
988                         }
989                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
990                         result = __copy_to_user(p, rinfo, 
991                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
992                         result = result ? -EFAULT : 0;
993                         kfree(rinfo);
994                         return result;
995                 }
996         case SG_EMULATED_HOST:
997                 if (sdp->detached)
998                         return -ENODEV;
999                 return put_user(sdp->device->host->hostt->emulated, ip);
1000         case SG_SCSI_RESET:
1001                 if (sdp->detached)
1002                         return -ENODEV;
1003                 if (filp->f_flags & O_NONBLOCK) {
1004                         if (scsi_host_in_recovery(sdp->device->host))
1005                                 return -EBUSY;
1006                 } else if (!scsi_block_when_processing_errors(sdp->device))
1007                         return -EBUSY;
1008                 result = get_user(val, ip);
1009                 if (result)
1010                         return result;
1011                 if (SG_SCSI_RESET_NOTHING == val)
1012                         return 0;
1013                 switch (val) {
1014                 case SG_SCSI_RESET_DEVICE:
1015                         val = SCSI_TRY_RESET_DEVICE;
1016                         break;
1017                 case SG_SCSI_RESET_TARGET:
1018                         val = SCSI_TRY_RESET_TARGET;
1019                         break;
1020                 case SG_SCSI_RESET_BUS:
1021                         val = SCSI_TRY_RESET_BUS;
1022                         break;
1023                 case SG_SCSI_RESET_HOST:
1024                         val = SCSI_TRY_RESET_HOST;
1025                         break;
1026                 default:
1027                         return -EINVAL;
1028                 }
1029                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1030                         return -EACCES;
1031                 return (scsi_reset_provider(sdp->device, val) ==
1032                         SUCCESS) ? 0 : -EIO;
1033         case SCSI_IOCTL_SEND_COMMAND:
1034                 if (sdp->detached)
1035                         return -ENODEV;
1036                 if (read_only) {
1037                         unsigned char opcode = WRITE_6;
1038                         Scsi_Ioctl_Command __user *siocp = p;
1039
1040                         if (copy_from_user(&opcode, siocp->data, 1))
1041                                 return -EFAULT;
1042                         if (sg_allow_access(filp, &opcode))
1043                                 return -EPERM;
1044                 }
1045                 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1046         case SG_SET_DEBUG:
1047                 result = get_user(val, ip);
1048                 if (result)
1049                         return result;
1050                 sdp->sgdebug = (char) val;
1051                 return 0;
1052         case SCSI_IOCTL_GET_IDLUN:
1053         case SCSI_IOCTL_GET_BUS_NUMBER:
1054         case SCSI_IOCTL_PROBE_HOST:
1055         case SG_GET_TRANSFORM:
1056                 if (sdp->detached)
1057                         return -ENODEV;
1058                 return scsi_ioctl(sdp->device, cmd_in, p);
1059         case BLKSECTGET:
1060                 return put_user(queue_max_sectors(sdp->device->request_queue) * 512,
1061                                 ip);
1062         case BLKTRACESETUP:
1063                 return blk_trace_setup(sdp->device->request_queue,
1064                                        sdp->disk->disk_name,
1065                                        MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1066                                        NULL,
1067                                        (char *)arg);
1068         case BLKTRACESTART:
1069                 return blk_trace_startstop(sdp->device->request_queue, 1);
1070         case BLKTRACESTOP:
1071                 return blk_trace_startstop(sdp->device->request_queue, 0);
1072         case BLKTRACETEARDOWN:
1073                 return blk_trace_remove(sdp->device->request_queue);
1074         default:
1075                 if (read_only)
1076                         return -EPERM;  /* don't know so take safe approach */
1077                 return scsi_ioctl(sdp->device, cmd_in, p);
1078         }
1079 }
1080
1081 #ifdef CONFIG_COMPAT
1082 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1083 {
1084         Sg_device *sdp;
1085         Sg_fd *sfp;
1086         struct scsi_device *sdev;
1087
1088         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1089                 return -ENXIO;
1090
1091         sdev = sdp->device;
1092         if (sdev->host->hostt->compat_ioctl) { 
1093                 int ret;
1094
1095                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1096
1097                 return ret;
1098         }
1099         
1100         return -ENOIOCTLCMD;
1101 }
1102 #endif
1103
1104 static unsigned int
1105 sg_poll(struct file *filp, poll_table * wait)
1106 {
1107         unsigned int res = 0;
1108         Sg_device *sdp;
1109         Sg_fd *sfp;
1110         Sg_request *srp;
1111         int count = 0;
1112         unsigned long iflags;
1113
1114         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1115             || sfp->closed)
1116                 return POLLERR;
1117         poll_wait(filp, &sfp->read_wait, wait);
1118         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1119         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1120                 /* if any read waiting, flag it */
1121                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1122                         res = POLLIN | POLLRDNORM;
1123                 ++count;
1124         }
1125         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1126
1127         if (sdp->detached)
1128                 res |= POLLHUP;
1129         else if (!sfp->cmd_q) {
1130                 if (0 == count)
1131                         res |= POLLOUT | POLLWRNORM;
1132         } else if (count < SG_MAX_QUEUE)
1133                 res |= POLLOUT | POLLWRNORM;
1134         SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1135                                    sdp->disk->disk_name, (int) res));
1136         return res;
1137 }
1138
1139 static int
1140 sg_fasync(int fd, struct file *filp, int mode)
1141 {
1142         Sg_device *sdp;
1143         Sg_fd *sfp;
1144
1145         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1146                 return -ENXIO;
1147         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1148                                    sdp->disk->disk_name, mode));
1149
1150         return fasync_helper(fd, filp, mode, &sfp->async_qp);
1151 }
1152
1153 static int
1154 sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1155 {
1156         Sg_fd *sfp;
1157         unsigned long offset, len, sa;
1158         Sg_scatter_hold *rsv_schp;
1159         int k, length;
1160
1161         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1162                 return VM_FAULT_SIGBUS;
1163         rsv_schp = &sfp->reserve;
1164         offset = vmf->pgoff << PAGE_SHIFT;
1165         if (offset >= rsv_schp->bufflen)
1166                 return VM_FAULT_SIGBUS;
1167         SCSI_LOG_TIMEOUT(3, printk("sg_vma_fault: offset=%lu, scatg=%d\n",
1168                                    offset, rsv_schp->k_use_sg));
1169         sa = vma->vm_start;
1170         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1171         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1172                 len = vma->vm_end - sa;
1173                 len = (len < length) ? len : length;
1174                 if (offset < len) {
1175                         struct page *page = nth_page(rsv_schp->pages[k],
1176                                                      offset >> PAGE_SHIFT);
1177                         get_page(page); /* increment page count */
1178                         vmf->page = page;
1179                         return 0; /* success */
1180                 }
1181                 sa += len;
1182                 offset -= len;
1183         }
1184
1185         return VM_FAULT_SIGBUS;
1186 }
1187
1188 static const struct vm_operations_struct sg_mmap_vm_ops = {
1189         .fault = sg_vma_fault,
1190 };
1191
1192 static int
1193 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1194 {
1195         Sg_fd *sfp;
1196         unsigned long req_sz, len, sa;
1197         Sg_scatter_hold *rsv_schp;
1198         int k, length;
1199
1200         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1201                 return -ENXIO;
1202         req_sz = vma->vm_end - vma->vm_start;
1203         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1204                                    (void *) vma->vm_start, (int) req_sz));
1205         if (vma->vm_pgoff)
1206                 return -EINVAL; /* want no offset */
1207         rsv_schp = &sfp->reserve;
1208         if (req_sz > rsv_schp->bufflen)
1209                 return -ENOMEM; /* cannot map more than reserved buffer */
1210
1211         sa = vma->vm_start;
1212         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1213         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1214                 len = vma->vm_end - sa;
1215                 len = (len < length) ? len : length;
1216                 sa += len;
1217         }
1218
1219         sfp->mmap_called = 1;
1220         vma->vm_flags |= VM_RESERVED;
1221         vma->vm_private_data = sfp;
1222         vma->vm_ops = &sg_mmap_vm_ops;
1223         return 0;
1224 }
1225
1226 static void sg_rq_end_io_usercontext(struct work_struct *work)
1227 {
1228         struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1229         struct sg_fd *sfp = srp->parentfp;
1230
1231         sg_finish_rem_req(srp);
1232         kref_put(&sfp->f_ref, sg_remove_sfp);
1233 }
1234
1235 /*
1236  * This function is a "bottom half" handler that is called by the mid
1237  * level when a command is completed (or has failed).
1238  */
1239 static void sg_rq_end_io(struct request *rq, int uptodate)
1240 {
1241         struct sg_request *srp = rq->end_io_data;
1242         Sg_device *sdp;
1243         Sg_fd *sfp;
1244         unsigned long iflags;
1245         unsigned int ms;
1246         char *sense;
1247         int result, resid, done = 1;
1248
1249         if (WARN_ON(srp->done != 0))
1250                 return;
1251
1252         sfp = srp->parentfp;
1253         if (WARN_ON(sfp == NULL))
1254                 return;
1255
1256         sdp = sfp->parentdp;
1257         if (unlikely(sdp->detached))
1258                 printk(KERN_INFO "sg_rq_end_io: device detached\n");
1259
1260         sense = rq->sense;
1261         result = rq->errors;
1262         resid = rq->resid_len;
1263
1264         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1265                 sdp->disk->disk_name, srp->header.pack_id, result));
1266         srp->header.resid = resid;
1267         ms = jiffies_to_msecs(jiffies);
1268         srp->header.duration = (ms > srp->header.duration) ?
1269                                 (ms - srp->header.duration) : 0;
1270         if (0 != result) {
1271                 struct scsi_sense_hdr sshdr;
1272
1273                 srp->header.status = 0xff & result;
1274                 srp->header.masked_status = status_byte(result);
1275                 srp->header.msg_status = msg_byte(result);
1276                 srp->header.host_status = host_byte(result);
1277                 srp->header.driver_status = driver_byte(result);
1278                 if ((sdp->sgdebug > 0) &&
1279                     ((CHECK_CONDITION == srp->header.masked_status) ||
1280                      (COMMAND_TERMINATED == srp->header.masked_status)))
1281                         __scsi_print_sense("sg_cmd_done", sense,
1282                                            SCSI_SENSE_BUFFERSIZE);
1283
1284                 /* Following if statement is a patch supplied by Eric Youngdale */
1285                 if (driver_byte(result) != 0
1286                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1287                     && !scsi_sense_is_deferred(&sshdr)
1288                     && sshdr.sense_key == UNIT_ATTENTION
1289                     && sdp->device->removable) {
1290                         /* Detected possible disc change. Set the bit - this */
1291                         /* may be used if there are filesystems using this device */
1292                         sdp->device->changed = 1;
1293                 }
1294         }
1295         /* Rely on write phase to clean out srp status values, so no "else" */
1296
1297         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1298         if (unlikely(srp->orphan)) {
1299                 if (sfp->keep_orphan)
1300                         srp->sg_io_owned = 0;
1301                 else
1302                         done = 0;
1303         }
1304         srp->done = done;
1305         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1306
1307         if (likely(done)) {
1308                 /* Now wake up any sg_read() that is waiting for this
1309                  * packet.
1310                  */
1311                 wake_up_interruptible(&sfp->read_wait);
1312                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1313                 kref_put(&sfp->f_ref, sg_remove_sfp);
1314         } else {
1315                 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1316                 schedule_work(&srp->ew.work);
1317         }
1318 }
1319
1320 static const struct file_operations sg_fops = {
1321         .owner = THIS_MODULE,
1322         .read = sg_read,
1323         .write = sg_write,
1324         .poll = sg_poll,
1325         .ioctl = sg_ioctl,
1326 #ifdef CONFIG_COMPAT
1327         .compat_ioctl = sg_compat_ioctl,
1328 #endif
1329         .open = sg_open,
1330         .mmap = sg_mmap,
1331         .release = sg_release,
1332         .fasync = sg_fasync,
1333 };
1334
1335 static struct class *sg_sysfs_class;
1336
1337 static int sg_sysfs_valid = 0;
1338
1339 static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1340 {
1341         struct request_queue *q = scsidp->request_queue;
1342         Sg_device *sdp;
1343         unsigned long iflags;
1344         int error;
1345         u32 k;
1346
1347         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1348         if (!sdp) {
1349                 printk(KERN_WARNING "kmalloc Sg_device failure\n");
1350                 return ERR_PTR(-ENOMEM);
1351         }
1352
1353         if (!idr_pre_get(&sg_index_idr, GFP_KERNEL)) {
1354                 printk(KERN_WARNING "idr expansion Sg_device failure\n");
1355                 error = -ENOMEM;
1356                 goto out;
1357         }
1358
1359         write_lock_irqsave(&sg_index_lock, iflags);
1360
1361         error = idr_get_new(&sg_index_idr, sdp, &k);
1362         if (error) {
1363                 write_unlock_irqrestore(&sg_index_lock, iflags);
1364                 printk(KERN_WARNING "idr allocation Sg_device failure: %d\n",
1365                        error);
1366                 goto out;
1367         }
1368
1369         if (unlikely(k >= SG_MAX_DEVS))
1370                 goto overflow;
1371
1372         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1373         sprintf(disk->disk_name, "sg%d", k);
1374         disk->first_minor = k;
1375         sdp->disk = disk;
1376         sdp->device = scsidp;
1377         INIT_LIST_HEAD(&sdp->sfds);
1378         init_waitqueue_head(&sdp->o_excl_wait);
1379         sdp->sg_tablesize = queue_max_segments(q);
1380         sdp->index = k;
1381         kref_init(&sdp->d_ref);
1382
1383         write_unlock_irqrestore(&sg_index_lock, iflags);
1384
1385         error = 0;
1386  out:
1387         if (error) {
1388                 kfree(sdp);
1389                 return ERR_PTR(error);
1390         }
1391         return sdp;
1392
1393  overflow:
1394         idr_remove(&sg_index_idr, k);
1395         write_unlock_irqrestore(&sg_index_lock, iflags);
1396         sdev_printk(KERN_WARNING, scsidp,
1397                     "Unable to attach sg device type=%d, minor "
1398                     "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1399         error = -ENODEV;
1400         goto out;
1401 }
1402
1403 static int
1404 sg_add(struct device *cl_dev, struct class_interface *cl_intf)
1405 {
1406         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1407         struct gendisk *disk;
1408         Sg_device *sdp = NULL;
1409         struct cdev * cdev = NULL;
1410         int error;
1411         unsigned long iflags;
1412
1413         disk = alloc_disk(1);
1414         if (!disk) {
1415                 printk(KERN_WARNING "alloc_disk failed\n");
1416                 return -ENOMEM;
1417         }
1418         disk->major = SCSI_GENERIC_MAJOR;
1419
1420         error = -ENOMEM;
1421         cdev = cdev_alloc();
1422         if (!cdev) {
1423                 printk(KERN_WARNING "cdev_alloc failed\n");
1424                 goto out;
1425         }
1426         cdev->owner = THIS_MODULE;
1427         cdev->ops = &sg_fops;
1428
1429         sdp = sg_alloc(disk, scsidp);
1430         if (IS_ERR(sdp)) {
1431                 printk(KERN_WARNING "sg_alloc failed\n");
1432                 error = PTR_ERR(sdp);
1433                 goto out;
1434         }
1435
1436         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1437         if (error)
1438                 goto cdev_add_err;
1439
1440         sdp->cdev = cdev;
1441         if (sg_sysfs_valid) {
1442                 struct device *sg_class_member;
1443
1444                 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1445                                                 MKDEV(SCSI_GENERIC_MAJOR,
1446                                                       sdp->index),
1447                                                 sdp, "%s", disk->disk_name);
1448                 if (IS_ERR(sg_class_member)) {
1449                         printk(KERN_ERR "sg_add: "
1450                                "device_create failed\n");
1451                         error = PTR_ERR(sg_class_member);
1452                         goto cdev_add_err;
1453                 }
1454                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1455                                           &sg_class_member->kobj, "generic");
1456                 if (error)
1457                         printk(KERN_ERR "sg_add: unable to make symlink "
1458                                         "'generic' back to sg%d\n", sdp->index);
1459         } else
1460                 printk(KERN_WARNING "sg_add: sg_sys Invalid\n");
1461
1462         sdev_printk(KERN_NOTICE, scsidp,
1463                     "Attached scsi generic sg%d type %d\n", sdp->index,
1464                     scsidp->type);
1465
1466         dev_set_drvdata(cl_dev, sdp);
1467
1468         return 0;
1469
1470 cdev_add_err:
1471         write_lock_irqsave(&sg_index_lock, iflags);
1472         idr_remove(&sg_index_idr, sdp->index);
1473         write_unlock_irqrestore(&sg_index_lock, iflags);
1474         kfree(sdp);
1475
1476 out:
1477         put_disk(disk);
1478         if (cdev)
1479                 cdev_del(cdev);
1480         return error;
1481 }
1482
1483 static void sg_device_destroy(struct kref *kref)
1484 {
1485         struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1486         unsigned long flags;
1487
1488         /* CAUTION!  Note that the device can still be found via idr_find()
1489          * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1490          * any other cleanup.
1491          */
1492
1493         write_lock_irqsave(&sg_index_lock, flags);
1494         idr_remove(&sg_index_idr, sdp->index);
1495         write_unlock_irqrestore(&sg_index_lock, flags);
1496
1497         SCSI_LOG_TIMEOUT(3,
1498                 printk("sg_device_destroy: %s\n",
1499                         sdp->disk->disk_name));
1500
1501         put_disk(sdp->disk);
1502         kfree(sdp);
1503 }
1504
1505 static void sg_remove(struct device *cl_dev, struct class_interface *cl_intf)
1506 {
1507         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1508         Sg_device *sdp = dev_get_drvdata(cl_dev);
1509         unsigned long iflags;
1510         Sg_fd *sfp;
1511
1512         if (!sdp || sdp->detached)
1513                 return;
1514
1515         SCSI_LOG_TIMEOUT(3, printk("sg_remove: %s\n", sdp->disk->disk_name));
1516
1517         /* Need a write lock to set sdp->detached. */
1518         write_lock_irqsave(&sg_index_lock, iflags);
1519         sdp->detached = 1;
1520         list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1521                 wake_up_interruptible(&sfp->read_wait);
1522                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1523         }
1524         write_unlock_irqrestore(&sg_index_lock, iflags);
1525
1526         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1527         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1528         cdev_del(sdp->cdev);
1529         sdp->cdev = NULL;
1530
1531         sg_put_dev(sdp);
1532 }
1533
1534 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1535 module_param_named(def_reserved_size, def_reserved_size, int,
1536                    S_IRUGO | S_IWUSR);
1537 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1538
1539 MODULE_AUTHOR("Douglas Gilbert");
1540 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1541 MODULE_LICENSE("GPL");
1542 MODULE_VERSION(SG_VERSION_STR);
1543 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1544
1545 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1546                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1547 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1548 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1549
1550 static int __init
1551 init_sg(void)
1552 {
1553         int rc;
1554
1555         if (scatter_elem_sz < PAGE_SIZE) {
1556                 scatter_elem_sz = PAGE_SIZE;
1557                 scatter_elem_sz_prev = scatter_elem_sz;
1558         }
1559         if (def_reserved_size >= 0)
1560                 sg_big_buff = def_reserved_size;
1561         else
1562                 def_reserved_size = sg_big_buff;
1563
1564         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), 
1565                                     SG_MAX_DEVS, "sg");
1566         if (rc)
1567                 return rc;
1568         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1569         if ( IS_ERR(sg_sysfs_class) ) {
1570                 rc = PTR_ERR(sg_sysfs_class);
1571                 goto err_out;
1572         }
1573         sg_sysfs_valid = 1;
1574         rc = scsi_register_interface(&sg_interface);
1575         if (0 == rc) {
1576 #ifdef CONFIG_SCSI_PROC_FS
1577                 sg_proc_init();
1578 #endif                          /* CONFIG_SCSI_PROC_FS */
1579                 return 0;
1580         }
1581         class_destroy(sg_sysfs_class);
1582 err_out:
1583         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1584         return rc;
1585 }
1586
1587 static void __exit
1588 exit_sg(void)
1589 {
1590 #ifdef CONFIG_SCSI_PROC_FS
1591         sg_proc_cleanup();
1592 #endif                          /* CONFIG_SCSI_PROC_FS */
1593         scsi_unregister_interface(&sg_interface);
1594         class_destroy(sg_sysfs_class);
1595         sg_sysfs_valid = 0;
1596         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1597                                  SG_MAX_DEVS);
1598         idr_destroy(&sg_index_idr);
1599 }
1600
1601 static int sg_start_req(Sg_request *srp, unsigned char *cmd)
1602 {
1603         int res;
1604         struct request *rq;
1605         Sg_fd *sfp = srp->parentfp;
1606         sg_io_hdr_t *hp = &srp->header;
1607         int dxfer_len = (int) hp->dxfer_len;
1608         int dxfer_dir = hp->dxfer_direction;
1609         unsigned int iov_count = hp->iovec_count;
1610         Sg_scatter_hold *req_schp = &srp->data;
1611         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1612         struct request_queue *q = sfp->parentdp->device->request_queue;
1613         struct rq_map_data *md, map_data;
1614         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1615
1616         SCSI_LOG_TIMEOUT(4, printk(KERN_INFO "sg_start_req: dxfer_len=%d\n",
1617                                    dxfer_len));
1618
1619         rq = blk_get_request(q, rw, GFP_ATOMIC);
1620         if (!rq)
1621                 return -ENOMEM;
1622
1623         memcpy(rq->cmd, cmd, hp->cmd_len);
1624
1625         rq->cmd_len = hp->cmd_len;
1626         rq->cmd_type = REQ_TYPE_BLOCK_PC;
1627
1628         srp->rq = rq;
1629         rq->end_io_data = srp;
1630         rq->sense = srp->sense_b;
1631         rq->retries = SG_DEFAULT_RETRIES;
1632
1633         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1634                 return 0;
1635
1636         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1637             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1638             !sfp->parentdp->device->host->unchecked_isa_dma &&
1639             blk_rq_aligned(q, hp->dxferp, dxfer_len))
1640                 md = NULL;
1641         else
1642                 md = &map_data;
1643
1644         if (md) {
1645                 if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen)
1646                         sg_link_reserve(sfp, srp, dxfer_len);
1647                 else {
1648                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1649                         if (res)
1650                                 return res;
1651                 }
1652
1653                 md->pages = req_schp->pages;
1654                 md->page_order = req_schp->page_order;
1655                 md->nr_entries = req_schp->k_use_sg;
1656                 md->offset = 0;
1657                 md->null_mapped = hp->dxferp ? 0 : 1;
1658                 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1659                         md->from_user = 1;
1660                 else
1661                         md->from_user = 0;
1662         }
1663
1664         if (iov_count) {
1665                 int len, size = sizeof(struct sg_iovec) * iov_count;
1666                 struct iovec *iov;
1667
1668                 iov = kmalloc(size, GFP_ATOMIC);
1669                 if (!iov)
1670                         return -ENOMEM;
1671
1672                 if (copy_from_user(iov, hp->dxferp, size)) {
1673                         kfree(iov);
1674                         return -EFAULT;
1675                 }
1676
1677                 len = iov_length(iov, iov_count);
1678                 if (hp->dxfer_len < len) {
1679                         iov_count = iov_shorten(iov, iov_count, hp->dxfer_len);
1680                         len = hp->dxfer_len;
1681                 }
1682
1683                 res = blk_rq_map_user_iov(q, rq, md, (struct sg_iovec *)iov,
1684                                           iov_count,
1685                                           len, GFP_ATOMIC);
1686                 kfree(iov);
1687         } else
1688                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1689                                       hp->dxfer_len, GFP_ATOMIC);
1690
1691         if (!res) {
1692                 srp->bio = rq->bio;
1693
1694                 if (!md) {
1695                         req_schp->dio_in_use = 1;
1696                         hp->info |= SG_INFO_DIRECT_IO;
1697                 }
1698         }
1699         return res;
1700 }
1701
1702 static int sg_finish_rem_req(Sg_request * srp)
1703 {
1704         int ret = 0;
1705
1706         Sg_fd *sfp = srp->parentfp;
1707         Sg_scatter_hold *req_schp = &srp->data;
1708
1709         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1710         if (srp->rq) {
1711                 if (srp->bio)
1712                         ret = blk_rq_unmap_user(srp->bio);
1713
1714                 blk_put_request(srp->rq);
1715         }
1716
1717         if (srp->res_used)
1718                 sg_unlink_reserve(sfp, srp);
1719         else
1720                 sg_remove_scat(req_schp);
1721
1722         sg_remove_request(sfp, srp);
1723
1724         return ret;
1725 }
1726
1727 static int
1728 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1729 {
1730         int sg_bufflen = tablesize * sizeof(struct page *);
1731         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1732
1733         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1734         if (!schp->pages)
1735                 return -ENOMEM;
1736         schp->sglist_len = sg_bufflen;
1737         return tablesize;       /* number of scat_gath elements allocated */
1738 }
1739
1740 static int
1741 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1742 {
1743         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1744         int sg_tablesize = sfp->parentdp->sg_tablesize;
1745         int blk_size = buff_size, order;
1746         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1747
1748         if (blk_size < 0)
1749                 return -EFAULT;
1750         if (0 == blk_size)
1751                 ++blk_size;     /* don't know why */
1752         /* round request up to next highest SG_SECTOR_SZ byte boundary */
1753         blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1754         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1755                                    buff_size, blk_size));
1756
1757         /* N.B. ret_sz carried into this block ... */
1758         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1759         if (mx_sc_elems < 0)
1760                 return mx_sc_elems;     /* most likely -ENOMEM */
1761
1762         num = scatter_elem_sz;
1763         if (unlikely(num != scatter_elem_sz_prev)) {
1764                 if (num < PAGE_SIZE) {
1765                         scatter_elem_sz = PAGE_SIZE;
1766                         scatter_elem_sz_prev = PAGE_SIZE;
1767                 } else
1768                         scatter_elem_sz_prev = num;
1769         }
1770
1771         if (sfp->low_dma)
1772                 gfp_mask |= GFP_DMA;
1773
1774         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1775                 gfp_mask |= __GFP_ZERO;
1776
1777         order = get_order(num);
1778 retry:
1779         ret_sz = 1 << (PAGE_SHIFT + order);
1780
1781         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1782              k++, rem_sz -= ret_sz) {
1783
1784                 num = (rem_sz > scatter_elem_sz_prev) ?
1785                         scatter_elem_sz_prev : rem_sz;
1786
1787                 schp->pages[k] = alloc_pages(gfp_mask, order);
1788                 if (!schp->pages[k])
1789                         goto out;
1790
1791                 if (num == scatter_elem_sz_prev) {
1792                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1793                                 scatter_elem_sz = ret_sz;
1794                                 scatter_elem_sz_prev = ret_sz;
1795                         }
1796                 }
1797
1798                 SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k=%d, num=%d, "
1799                                  "ret_sz=%d\n", k, num, ret_sz));
1800         }               /* end of for loop */
1801
1802         schp->page_order = order;
1803         schp->k_use_sg = k;
1804         SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, "
1805                          "rem_sz=%d\n", k, rem_sz));
1806
1807         schp->bufflen = blk_size;
1808         if (rem_sz > 0) /* must have failed */
1809                 return -ENOMEM;
1810         return 0;
1811 out:
1812         for (i = 0; i < k; i++)
1813                 __free_pages(schp->pages[i], order);
1814
1815         if (--order >= 0)
1816                 goto retry;
1817
1818         return -ENOMEM;
1819 }
1820
1821 static void
1822 sg_remove_scat(Sg_scatter_hold * schp)
1823 {
1824         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1825         if (schp->pages && schp->sglist_len > 0) {
1826                 if (!schp->dio_in_use) {
1827                         int k;
1828
1829                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1830                                 SCSI_LOG_TIMEOUT(5, printk(
1831                                     "sg_remove_scat: k=%d, pg=0x%p\n",
1832                                     k, schp->pages[k]));
1833                                 __free_pages(schp->pages[k], schp->page_order);
1834                         }
1835
1836                         kfree(schp->pages);
1837                 }
1838         }
1839         memset(schp, 0, sizeof (*schp));
1840 }
1841
1842 static int
1843 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1844 {
1845         Sg_scatter_hold *schp = &srp->data;
1846         int k, num;
1847
1848         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
1849                                    num_read_xfer));
1850         if ((!outp) || (num_read_xfer <= 0))
1851                 return 0;
1852
1853         num = 1 << (PAGE_SHIFT + schp->page_order);
1854         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1855                 if (num > num_read_xfer) {
1856                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1857                                            num_read_xfer))
1858                                 return -EFAULT;
1859                         break;
1860                 } else {
1861                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1862                                            num))
1863                                 return -EFAULT;
1864                         num_read_xfer -= num;
1865                         if (num_read_xfer <= 0)
1866                                 break;
1867                         outp += num;
1868                 }
1869         }
1870
1871         return 0;
1872 }
1873
1874 static void
1875 sg_build_reserve(Sg_fd * sfp, int req_size)
1876 {
1877         Sg_scatter_hold *schp = &sfp->reserve;
1878
1879         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
1880         do {
1881                 if (req_size < PAGE_SIZE)
1882                         req_size = PAGE_SIZE;
1883                 if (0 == sg_build_indirect(schp, sfp, req_size))
1884                         return;
1885                 else
1886                         sg_remove_scat(schp);
1887                 req_size >>= 1; /* divide by 2 */
1888         } while (req_size > (PAGE_SIZE / 2));
1889 }
1890
1891 static void
1892 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1893 {
1894         Sg_scatter_hold *req_schp = &srp->data;
1895         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1896         int k, num, rem;
1897
1898         srp->res_used = 1;
1899         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
1900         rem = size;
1901
1902         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1903         for (k = 0; k < rsv_schp->k_use_sg; k++) {
1904                 if (rem <= num) {
1905                         req_schp->k_use_sg = k + 1;
1906                         req_schp->sglist_len = rsv_schp->sglist_len;
1907                         req_schp->pages = rsv_schp->pages;
1908
1909                         req_schp->bufflen = size;
1910                         req_schp->page_order = rsv_schp->page_order;
1911                         break;
1912                 } else
1913                         rem -= num;
1914         }
1915
1916         if (k >= rsv_schp->k_use_sg)
1917                 SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
1918 }
1919
1920 static void
1921 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
1922 {
1923         Sg_scatter_hold *req_schp = &srp->data;
1924
1925         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
1926                                    (int) req_schp->k_use_sg));
1927         req_schp->k_use_sg = 0;
1928         req_schp->bufflen = 0;
1929         req_schp->pages = NULL;
1930         req_schp->page_order = 0;
1931         req_schp->sglist_len = 0;
1932         sfp->save_scat_len = 0;
1933         srp->res_used = 0;
1934 }
1935
1936 static Sg_request *
1937 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
1938 {
1939         Sg_request *resp;
1940         unsigned long iflags;
1941
1942         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1943         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
1944                 /* look for requests that are ready + not SG_IO owned */
1945                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
1946                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
1947                         resp->done = 2; /* guard against other readers */
1948                         break;
1949                 }
1950         }
1951         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1952         return resp;
1953 }
1954
1955 /* always adds to end of list */
1956 static Sg_request *
1957 sg_add_request(Sg_fd * sfp)
1958 {
1959         int k;
1960         unsigned long iflags;
1961         Sg_request *resp;
1962         Sg_request *rp = sfp->req_arr;
1963
1964         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1965         resp = sfp->headrp;
1966         if (!resp) {
1967                 memset(rp, 0, sizeof (Sg_request));
1968                 rp->parentfp = sfp;
1969                 resp = rp;
1970                 sfp->headrp = resp;
1971         } else {
1972                 if (0 == sfp->cmd_q)
1973                         resp = NULL;    /* command queuing disallowed */
1974                 else {
1975                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
1976                                 if (!rp->parentfp)
1977                                         break;
1978                         }
1979                         if (k < SG_MAX_QUEUE) {
1980                                 memset(rp, 0, sizeof (Sg_request));
1981                                 rp->parentfp = sfp;
1982                                 while (resp->nextrp)
1983                                         resp = resp->nextrp;
1984                                 resp->nextrp = rp;
1985                                 resp = rp;
1986                         } else
1987                                 resp = NULL;
1988                 }
1989         }
1990         if (resp) {
1991                 resp->nextrp = NULL;
1992                 resp->header.duration = jiffies_to_msecs(jiffies);
1993         }
1994         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1995         return resp;
1996 }
1997
1998 /* Return of 1 for found; 0 for not found */
1999 static int
2000 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2001 {
2002         Sg_request *prev_rp;
2003         Sg_request *rp;
2004         unsigned long iflags;
2005         int res = 0;
2006
2007         if ((!sfp) || (!srp) || (!sfp->headrp))
2008                 return res;
2009         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2010         prev_rp = sfp->headrp;
2011         if (srp == prev_rp) {
2012                 sfp->headrp = prev_rp->nextrp;
2013                 prev_rp->parentfp = NULL;
2014                 res = 1;
2015         } else {
2016                 while ((rp = prev_rp->nextrp)) {
2017                         if (srp == rp) {
2018                                 prev_rp->nextrp = rp->nextrp;
2019                                 rp->parentfp = NULL;
2020                                 res = 1;
2021                                 break;
2022                         }
2023                         prev_rp = rp;
2024                 }
2025         }
2026         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2027         return res;
2028 }
2029
2030 static Sg_fd *
2031 sg_add_sfp(Sg_device * sdp, int dev)
2032 {
2033         Sg_fd *sfp;
2034         unsigned long iflags;
2035         int bufflen;
2036
2037         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2038         if (!sfp)
2039                 return NULL;
2040
2041         init_waitqueue_head(&sfp->read_wait);
2042         rwlock_init(&sfp->rq_list_lock);
2043
2044         kref_init(&sfp->f_ref);
2045         sfp->timeout = SG_DEFAULT_TIMEOUT;
2046         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2047         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2048         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2049             sdp->device->host->unchecked_isa_dma : 1;
2050         sfp->cmd_q = SG_DEF_COMMAND_Q;
2051         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2052         sfp->parentdp = sdp;
2053         write_lock_irqsave(&sg_index_lock, iflags);
2054         list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2055         write_unlock_irqrestore(&sg_index_lock, iflags);
2056         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2057         if (unlikely(sg_big_buff != def_reserved_size))
2058                 sg_big_buff = def_reserved_size;
2059
2060         bufflen = min_t(int, sg_big_buff,
2061                         queue_max_sectors(sdp->device->request_queue) * 512);
2062         sg_build_reserve(sfp, bufflen);
2063         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2064                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2065
2066         kref_get(&sdp->d_ref);
2067         __module_get(THIS_MODULE);
2068         return sfp;
2069 }
2070
2071 static void sg_remove_sfp_usercontext(struct work_struct *work)
2072 {
2073         struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2074         struct sg_device *sdp = sfp->parentdp;
2075
2076         /* Cleanup any responses which were never read(). */
2077         while (sfp->headrp)
2078                 sg_finish_rem_req(sfp->headrp);
2079
2080         if (sfp->reserve.bufflen > 0) {
2081                 SCSI_LOG_TIMEOUT(6,
2082                         printk("sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2083                                 (int) sfp->reserve.bufflen,
2084                                 (int) sfp->reserve.k_use_sg));
2085                 sg_remove_scat(&sfp->reserve);
2086         }
2087
2088         SCSI_LOG_TIMEOUT(6,
2089                 printk("sg_remove_sfp: %s, sfp=0x%p\n",
2090                         sdp->disk->disk_name,
2091                         sfp));
2092         kfree(sfp);
2093
2094         scsi_device_put(sdp->device);
2095         sg_put_dev(sdp);
2096         module_put(THIS_MODULE);
2097 }
2098
2099 static void sg_remove_sfp(struct kref *kref)
2100 {
2101         struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2102         struct sg_device *sdp = sfp->parentdp;
2103         unsigned long iflags;
2104
2105         write_lock_irqsave(&sg_index_lock, iflags);
2106         list_del(&sfp->sfd_siblings);
2107         write_unlock_irqrestore(&sg_index_lock, iflags);
2108         wake_up_interruptible(&sdp->o_excl_wait);
2109
2110         INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2111         schedule_work(&sfp->ew.work);
2112 }
2113
2114 static int
2115 sg_res_in_use(Sg_fd * sfp)
2116 {
2117         const Sg_request *srp;
2118         unsigned long iflags;
2119
2120         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2121         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2122                 if (srp->res_used)
2123                         break;
2124         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2125         return srp ? 1 : 0;
2126 }
2127
2128 #ifdef CONFIG_SCSI_PROC_FS
2129 static int
2130 sg_idr_max_id(int id, void *p, void *data)
2131 {
2132         int *k = data;
2133
2134         if (*k < id)
2135                 *k = id;
2136
2137         return 0;
2138 }
2139
2140 static int
2141 sg_last_dev(void)
2142 {
2143         int k = -1;
2144         unsigned long iflags;
2145
2146         read_lock_irqsave(&sg_index_lock, iflags);
2147         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2148         read_unlock_irqrestore(&sg_index_lock, iflags);
2149         return k + 1;           /* origin 1 */
2150 }
2151 #endif
2152
2153 /* must be called with sg_index_lock held */
2154 static Sg_device *sg_lookup_dev(int dev)
2155 {
2156         return idr_find(&sg_index_idr, dev);
2157 }
2158
2159 static Sg_device *sg_get_dev(int dev)
2160 {
2161         struct sg_device *sdp;
2162         unsigned long flags;
2163
2164         read_lock_irqsave(&sg_index_lock, flags);
2165         sdp = sg_lookup_dev(dev);
2166         if (!sdp)
2167                 sdp = ERR_PTR(-ENXIO);
2168         else if (sdp->detached) {
2169                 /* If sdp->detached, then the refcount may already be 0, in
2170                  * which case it would be a bug to do kref_get().
2171                  */
2172                 sdp = ERR_PTR(-ENODEV);
2173         } else
2174                 kref_get(&sdp->d_ref);
2175         read_unlock_irqrestore(&sg_index_lock, flags);
2176
2177         return sdp;
2178 }
2179
2180 static void sg_put_dev(struct sg_device *sdp)
2181 {
2182         kref_put(&sdp->d_ref, sg_device_destroy);
2183 }
2184
2185 #ifdef CONFIG_SCSI_PROC_FS
2186
2187 static struct proc_dir_entry *sg_proc_sgp = NULL;
2188
2189 static char sg_proc_sg_dirname[] = "scsi/sg";
2190
2191 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2192
2193 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2194 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2195                                   size_t count, loff_t *off);
2196 static const struct file_operations adio_fops = {
2197         .owner = THIS_MODULE,
2198         .open = sg_proc_single_open_adio,
2199         .read = seq_read,
2200         .llseek = seq_lseek,
2201         .write = sg_proc_write_adio,
2202         .release = single_release,
2203 };
2204
2205 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2206 static ssize_t sg_proc_write_dressz(struct file *filp, 
2207                 const char __user *buffer, size_t count, loff_t *off);
2208 static const struct file_operations dressz_fops = {
2209         .owner = THIS_MODULE,
2210         .open = sg_proc_single_open_dressz,
2211         .read = seq_read,
2212         .llseek = seq_lseek,
2213         .write = sg_proc_write_dressz,
2214         .release = single_release,
2215 };
2216
2217 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2218 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2219 static const struct file_operations version_fops = {
2220         .owner = THIS_MODULE,
2221         .open = sg_proc_single_open_version,
2222         .read = seq_read,
2223         .llseek = seq_lseek,
2224         .release = single_release,
2225 };
2226
2227 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2228 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2229 static const struct file_operations devhdr_fops = {
2230         .owner = THIS_MODULE,
2231         .open = sg_proc_single_open_devhdr,
2232         .read = seq_read,
2233         .llseek = seq_lseek,
2234         .release = single_release,
2235 };
2236
2237 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2238 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2239 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2240 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2241 static void dev_seq_stop(struct seq_file *s, void *v);
2242 static const struct file_operations dev_fops = {
2243         .owner = THIS_MODULE,
2244         .open = sg_proc_open_dev,
2245         .read = seq_read,
2246         .llseek = seq_lseek,
2247         .release = seq_release,
2248 };
2249 static const struct seq_operations dev_seq_ops = {
2250         .start = dev_seq_start,
2251         .next  = dev_seq_next,
2252         .stop  = dev_seq_stop,
2253         .show  = sg_proc_seq_show_dev,
2254 };
2255
2256 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2257 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2258 static const struct file_operations devstrs_fops = {
2259         .owner = THIS_MODULE,
2260         .open = sg_proc_open_devstrs,
2261         .read = seq_read,
2262         .llseek = seq_lseek,
2263         .release = seq_release,
2264 };
2265 static const struct seq_operations devstrs_seq_ops = {
2266         .start = dev_seq_start,
2267         .next  = dev_seq_next,
2268         .stop  = dev_seq_stop,
2269         .show  = sg_proc_seq_show_devstrs,
2270 };
2271
2272 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2273 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2274 static const struct file_operations debug_fops = {
2275         .owner = THIS_MODULE,
2276         .open = sg_proc_open_debug,
2277         .read = seq_read,
2278         .llseek = seq_lseek,
2279         .release = seq_release,
2280 };
2281 static const struct seq_operations debug_seq_ops = {
2282         .start = dev_seq_start,
2283         .next  = dev_seq_next,
2284         .stop  = dev_seq_stop,
2285         .show  = sg_proc_seq_show_debug,
2286 };
2287
2288
2289 struct sg_proc_leaf {
2290         const char * name;
2291         const struct file_operations * fops;
2292 };
2293
2294 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2295         {"allow_dio", &adio_fops},
2296         {"debug", &debug_fops},
2297         {"def_reserved_size", &dressz_fops},
2298         {"device_hdr", &devhdr_fops},
2299         {"devices", &dev_fops},
2300         {"device_strs", &devstrs_fops},
2301         {"version", &version_fops}
2302 };
2303
2304 static int
2305 sg_proc_init(void)
2306 {
2307         int k, mask;
2308         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2309         struct sg_proc_leaf * leaf;
2310
2311         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2312         if (!sg_proc_sgp)
2313                 return 1;
2314         for (k = 0; k < num_leaves; ++k) {
2315                 leaf = &sg_proc_leaf_arr[k];
2316                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2317                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2318         }
2319         return 0;
2320 }
2321
2322 static void
2323 sg_proc_cleanup(void)
2324 {
2325         int k;
2326         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2327
2328         if (!sg_proc_sgp)
2329                 return;
2330         for (k = 0; k < num_leaves; ++k)
2331                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2332         remove_proc_entry(sg_proc_sg_dirname, NULL);
2333 }
2334
2335
2336 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2337 {
2338         seq_printf(s, "%d\n", *((int *)s->private));
2339         return 0;
2340 }
2341
2342 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2343 {
2344         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2345 }
2346
2347 static ssize_t 
2348 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2349                    size_t count, loff_t *off)
2350 {
2351         int num;
2352         char buff[11];
2353
2354         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2355                 return -EACCES;
2356         num = (count < 10) ? count : 10;
2357         if (copy_from_user(buff, buffer, num))
2358                 return -EFAULT;
2359         buff[num] = '\0';
2360         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2361         return count;
2362 }
2363
2364 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2365 {
2366         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2367 }
2368
2369 static ssize_t 
2370 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2371                      size_t count, loff_t *off)
2372 {
2373         int num;
2374         unsigned long k = ULONG_MAX;
2375         char buff[11];
2376
2377         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2378                 return -EACCES;
2379         num = (count < 10) ? count : 10;
2380         if (copy_from_user(buff, buffer, num))
2381                 return -EFAULT;
2382         buff[num] = '\0';
2383         k = simple_strtoul(buff, NULL, 10);
2384         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2385                 sg_big_buff = k;
2386                 return count;
2387         }
2388         return -ERANGE;
2389 }
2390
2391 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2392 {
2393         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2394                    sg_version_date);
2395         return 0;
2396 }
2397
2398 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2399 {
2400         return single_open(file, sg_proc_seq_show_version, NULL);
2401 }
2402
2403 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2404 {
2405         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2406                    "online\n");
2407         return 0;
2408 }
2409
2410 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2411 {
2412         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2413 }
2414
2415 struct sg_proc_deviter {
2416         loff_t  index;
2417         size_t  max;
2418 };
2419
2420 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2421 {
2422         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2423
2424         s->private = it;
2425         if (! it)
2426                 return NULL;
2427
2428         it->index = *pos;
2429         it->max = sg_last_dev();
2430         if (it->index >= it->max)
2431                 return NULL;
2432         return it;
2433 }
2434
2435 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2436 {
2437         struct sg_proc_deviter * it = s->private;
2438
2439         *pos = ++it->index;
2440         return (it->index < it->max) ? it : NULL;
2441 }
2442
2443 static void dev_seq_stop(struct seq_file *s, void *v)
2444 {
2445         kfree(s->private);
2446 }
2447
2448 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2449 {
2450         return seq_open(file, &dev_seq_ops);
2451 }
2452
2453 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2454 {
2455         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2456         Sg_device *sdp;
2457         struct scsi_device *scsidp;
2458         unsigned long iflags;
2459
2460         read_lock_irqsave(&sg_index_lock, iflags);
2461         sdp = it ? sg_lookup_dev(it->index) : NULL;
2462         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2463                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2464                               scsidp->host->host_no, scsidp->channel,
2465                               scsidp->id, scsidp->lun, (int) scsidp->type,
2466                               1,
2467                               (int) scsidp->queue_depth,
2468                               (int) scsidp->device_busy,
2469                               (int) scsi_device_online(scsidp));
2470         else
2471                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2472         read_unlock_irqrestore(&sg_index_lock, iflags);
2473         return 0;
2474 }
2475
2476 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2477 {
2478         return seq_open(file, &devstrs_seq_ops);
2479 }
2480
2481 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2482 {
2483         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2484         Sg_device *sdp;
2485         struct scsi_device *scsidp;
2486         unsigned long iflags;
2487
2488         read_lock_irqsave(&sg_index_lock, iflags);
2489         sdp = it ? sg_lookup_dev(it->index) : NULL;
2490         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2491                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2492                            scsidp->vendor, scsidp->model, scsidp->rev);
2493         else
2494                 seq_printf(s, "<no active device>\n");
2495         read_unlock_irqrestore(&sg_index_lock, iflags);
2496         return 0;
2497 }
2498
2499 /* must be called while holding sg_index_lock */
2500 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2501 {
2502         int k, m, new_interface, blen, usg;
2503         Sg_request *srp;
2504         Sg_fd *fp;
2505         const sg_io_hdr_t *hp;
2506         const char * cp;
2507         unsigned int ms;
2508
2509         k = 0;
2510         list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2511                 k++;
2512                 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2513                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2514                            "(res)sgat=%d low_dma=%d\n", k,
2515                            jiffies_to_msecs(fp->timeout),
2516                            fp->reserve.bufflen,
2517                            (int) fp->reserve.k_use_sg,
2518                            (int) fp->low_dma);
2519                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2520                            (int) fp->cmd_q, (int) fp->force_packid,
2521                            (int) fp->keep_orphan, (int) fp->closed);
2522                 for (m = 0, srp = fp->headrp;
2523                                 srp != NULL;
2524                                 ++m, srp = srp->nextrp) {
2525                         hp = &srp->header;
2526                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2527                         if (srp->res_used) {
2528                                 if (new_interface && 
2529                                     (SG_FLAG_MMAP_IO & hp->flags))
2530                                         cp = "     mmap>> ";
2531                                 else
2532                                         cp = "     rb>> ";
2533                         } else {
2534                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2535                                         cp = "     dio>> ";
2536                                 else
2537                                         cp = "     ";
2538                         }
2539                         seq_printf(s, cp);
2540                         blen = srp->data.bufflen;
2541                         usg = srp->data.k_use_sg;
2542                         seq_printf(s, srp->done ? 
2543                                    ((1 == srp->done) ?  "rcv:" : "fin:")
2544                                    : "act:");
2545                         seq_printf(s, " id=%d blen=%d",
2546                                    srp->header.pack_id, blen);
2547                         if (srp->done)
2548                                 seq_printf(s, " dur=%d", hp->duration);
2549                         else {
2550                                 ms = jiffies_to_msecs(jiffies);
2551                                 seq_printf(s, " t_o/elap=%d/%d",
2552                                         (new_interface ? hp->timeout :
2553                                                   jiffies_to_msecs(fp->timeout)),
2554                                         (ms > hp->duration ? ms - hp->duration : 0));
2555                         }
2556                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2557                                    (int) srp->data.cmd_opcode);
2558                 }
2559                 if (0 == m)
2560                         seq_printf(s, "     No requests active\n");
2561                 read_unlock(&fp->rq_list_lock);
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         unsigned long iflags;
2575
2576         if (it && (0 == it->index)) {
2577                 seq_printf(s, "max_active_device=%d(origin 1)\n",
2578                            (int)it->max);
2579                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2580         }
2581
2582         read_lock_irqsave(&sg_index_lock, iflags);
2583         sdp = it ? sg_lookup_dev(it->index) : NULL;
2584         if (sdp && !list_empty(&sdp->sfds)) {
2585                 struct scsi_device *scsidp = sdp->device;
2586
2587                 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2588                 if (sdp->detached)
2589                         seq_printf(s, "detached pending close ");
2590                 else
2591                         seq_printf
2592                             (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2593                              scsidp->host->host_no,
2594                              scsidp->channel, scsidp->id,
2595                              scsidp->lun,
2596                              scsidp->host->hostt->emulated);
2597                 seq_printf(s, " sg_tablesize=%d excl=%d\n",
2598                            sdp->sg_tablesize, sdp->exclude);
2599                 sg_proc_debug_helper(s, sdp);
2600         }
2601         read_unlock_irqrestore(&sg_index_lock, iflags);
2602         return 0;
2603 }
2604
2605 #endif                          /* CONFIG_SCSI_PROC_FS */
2606
2607 module_init(init_sg);
2608 module_exit(exit_sg);