block: Consolidate phys_segment and hw_segment limits
[linux-3.10.git] / drivers / scsi / sg.c
1 /*
2  *  History:
3  *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
4  *           to allow user process control of SCSI devices.
5  *  Development Sponsored by Killy Corp. NY NY
6  *
7  * Original driver (sg.c):
8  *        Copyright (C) 1992 Lawrence Foard
9  * Version 2 and 3 extensions to driver:
10  *        Copyright (C) 1998 - 2005 Douglas Gilbert
11  *
12  *  Modified  19-JAN-1998  Richard Gooch <rgooch@atnf.csiro.au>  Devfs support
13  *
14  * This program is free software; you can redistribute it and/or modify
15  * it under the terms of the GNU General Public License as published by
16  * the Free Software Foundation; either version 2, or (at your option)
17  * any later version.
18  *
19  */
20
21 static int sg_version_num = 30534;      /* 2 digits for each component */
22 #define SG_VERSION_STR "3.5.34"
23
24 /*
25  *  D. P. Gilbert (dgilbert@interlog.com, dougg@triode.net.au), notes:
26  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
27  *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
28  *        (otherwise the macros compile to empty statements).
29  *
30  */
31 #include <linux/module.h>
32
33 #include <linux/fs.h>
34 #include <linux/kernel.h>
35 #include <linux/sched.h>
36 #include <linux/string.h>
37 #include <linux/mm.h>
38 #include <linux/errno.h>
39 #include <linux/mtio.h>
40 #include <linux/ioctl.h>
41 #include <linux/fcntl.h>
42 #include <linux/init.h>
43 #include <linux/poll.h>
44 #include <linux/moduleparam.h>
45 #include <linux/cdev.h>
46 #include <linux/idr.h>
47 #include <linux/seq_file.h>
48 #include <linux/blkdev.h>
49 #include <linux/delay.h>
50 #include <linux/blktrace_api.h>
51 #include <linux/smp_lock.h>
52
53 #include "scsi.h"
54 #include <scsi/scsi_dbg.h>
55 #include <scsi/scsi_host.h>
56 #include <scsi/scsi_driver.h>
57 #include <scsi/scsi_ioctl.h>
58 #include <scsi/sg.h>
59
60 #include "scsi_logging.h"
61
62 #ifdef CONFIG_SCSI_PROC_FS
63 #include <linux/proc_fs.h>
64 static char *sg_version_date = "20061027";
65
66 static int sg_proc_init(void);
67 static void sg_proc_cleanup(void);
68 #endif
69
70 #define SG_ALLOW_DIO_DEF 0
71
72 #define SG_MAX_DEVS 32768
73
74 /*
75  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
76  * Then when using 32 bit integers x * m may overflow during the calculation.
77  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
78  * calculates the same, but prevents the overflow when both m and d
79  * are "small" numbers (like HZ and USER_HZ).
80  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
81  * in 32 bits.
82  */
83 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
84
85 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
86
87 int sg_big_buff = SG_DEF_RESERVED_SIZE;
88 /* N.B. This variable is readable and writeable via
89    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
90    of this size (or less if there is not enough memory) will be reserved
91    for use by this file descriptor. [Deprecated usage: this variable is also
92    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
93    the kernel (i.e. it is not a module).] */
94 static int def_reserved_size = -1;      /* picks up init parameter */
95 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
96
97 static int scatter_elem_sz = SG_SCATTER_SZ;
98 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
99
100 #define SG_SECTOR_SZ 512
101
102 static int sg_add(struct device *, struct class_interface *);
103 static void sg_remove(struct device *, struct class_interface *);
104
105 static DEFINE_IDR(sg_index_idr);
106 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
107                                                            file descriptor list for device */
108
109 static struct class_interface sg_interface = {
110         .add_dev        = sg_add,
111         .remove_dev     = sg_remove,
112 };
113
114 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
115         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
116         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
117         unsigned bufflen;       /* Size of (aggregate) data buffer */
118         struct page **pages;
119         int page_order;
120         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
121         unsigned char cmd_opcode; /* first byte of command */
122 } Sg_scatter_hold;
123
124 struct sg_device;               /* forward declarations */
125 struct sg_fd;
126
127 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
128         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
129         struct sg_fd *parentfp; /* NULL -> not in use */
130         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
131         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
132         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
133         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
134         char orphan;            /* 1 -> drop on sight, 0 -> normal */
135         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
136         volatile char done;     /* 0->before bh, 1->before read, 2->read */
137         struct request *rq;
138         struct bio *bio;
139         struct execute_work ew;
140 } Sg_request;
141
142 typedef struct sg_fd {          /* holds the state of a file descriptor */
143         struct list_head sfd_siblings;
144         struct sg_device *parentdp;     /* owning device */
145         wait_queue_head_t read_wait;    /* queue read until command done */
146         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
147         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
148         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
149         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
150         unsigned save_scat_len; /* original length of trunc. scat. element */
151         Sg_request *headrp;     /* head of request slist, NULL->empty */
152         struct fasync_struct *async_qp; /* used by asynchronous notification */
153         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
154         char low_dma;           /* as in parent but possibly overridden to 1 */
155         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
156         volatile char closed;   /* 1 -> fd closed but request(s) outstanding */
157         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
158         char next_cmd_len;      /* 0 -> automatic (def), >0 -> use on next write() */
159         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
160         char mmap_called;       /* 0 -> mmap() never called on this fd */
161         struct kref f_ref;
162         struct execute_work ew;
163 } Sg_fd;
164
165 typedef struct sg_device { /* holds the state of each scsi generic device */
166         struct scsi_device *device;
167         wait_queue_head_t o_excl_wait;  /* queue open() when O_EXCL in use */
168         int sg_tablesize;       /* adapter's max scatter-gather table size */
169         u32 index;              /* device index number */
170         struct list_head sfds;
171         volatile char detached; /* 0->attached, 1->detached pending removal */
172         volatile char exclude;  /* opened for exclusive access */
173         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
174         struct gendisk *disk;
175         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
176         struct kref d_ref;
177 } Sg_device;
178
179 /* tasklet or soft irq callback */
180 static void sg_rq_end_io(struct request *rq, int uptodate);
181 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
182 static int sg_finish_rem_req(Sg_request * srp);
183 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
184 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
185                            Sg_request * srp);
186 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
187                         const char __user *buf, size_t count, int blocking,
188                         int read_only, int sg_io_owned, Sg_request **o_srp);
189 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
190                            unsigned char *cmnd, int timeout, int blocking);
191 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
192 static void sg_remove_scat(Sg_scatter_hold * schp);
193 static void sg_build_reserve(Sg_fd * sfp, int req_size);
194 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
195 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
196 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
197 static void sg_remove_sfp(struct kref *);
198 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
199 static Sg_request *sg_add_request(Sg_fd * sfp);
200 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
201 static int sg_res_in_use(Sg_fd * sfp);
202 static Sg_device *sg_get_dev(int dev);
203 static void sg_put_dev(Sg_device *sdp);
204
205 #define SZ_SG_HEADER sizeof(struct sg_header)
206 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
207 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
208 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
209
210 static int sg_allow_access(struct file *filp, unsigned char *cmd)
211 {
212         struct sg_fd *sfp = (struct sg_fd *)filp->private_data;
213
214         if (sfp->parentdp->device->type == TYPE_SCANNER)
215                 return 0;
216
217         return blk_verify_command(cmd, filp->f_mode & FMODE_WRITE);
218 }
219
220 static int
221 sg_open(struct inode *inode, struct file *filp)
222 {
223         int dev = iminor(inode);
224         int flags = filp->f_flags;
225         struct request_queue *q;
226         Sg_device *sdp;
227         Sg_fd *sfp;
228         int res;
229         int retval;
230
231         lock_kernel();
232         nonseekable_open(inode, filp);
233         SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
234         sdp = sg_get_dev(dev);
235         if (IS_ERR(sdp)) {
236                 retval = PTR_ERR(sdp);
237                 sdp = NULL;
238                 goto sg_put;
239         }
240
241         /* This driver's module count bumped by fops_get in <linux/fs.h> */
242         /* Prevent the device driver from vanishing while we sleep */
243         retval = scsi_device_get(sdp->device);
244         if (retval)
245                 goto sg_put;
246
247         if (!((flags & O_NONBLOCK) ||
248               scsi_block_when_processing_errors(sdp->device))) {
249                 retval = -ENXIO;
250                 /* we are in error recovery for this device */
251                 goto error_out;
252         }
253
254         if (flags & O_EXCL) {
255                 if (O_RDONLY == (flags & O_ACCMODE)) {
256                         retval = -EPERM; /* Can't lock it with read only access */
257                         goto error_out;
258                 }
259                 if (!list_empty(&sdp->sfds) && (flags & O_NONBLOCK)) {
260                         retval = -EBUSY;
261                         goto error_out;
262                 }
263                 res = 0;
264                 __wait_event_interruptible(sdp->o_excl_wait,
265                                            ((!list_empty(&sdp->sfds) || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
266                 if (res) {
267                         retval = res;   /* -ERESTARTSYS because signal hit process */
268                         goto error_out;
269                 }
270         } else if (sdp->exclude) {      /* some other fd has an exclusive lock on dev */
271                 if (flags & O_NONBLOCK) {
272                         retval = -EBUSY;
273                         goto error_out;
274                 }
275                 res = 0;
276                 __wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
277                                            res);
278                 if (res) {
279                         retval = res;   /* -ERESTARTSYS because signal hit process */
280                         goto error_out;
281                 }
282         }
283         if (sdp->detached) {
284                 retval = -ENODEV;
285                 goto error_out;
286         }
287         if (list_empty(&sdp->sfds)) {   /* no existing opens on this device */
288                 sdp->sgdebug = 0;
289                 q = sdp->device->request_queue;
290                 sdp->sg_tablesize = queue_max_segments(q);
291         }
292         if ((sfp = sg_add_sfp(sdp, dev)))
293                 filp->private_data = sfp;
294         else {
295                 if (flags & O_EXCL) {
296                         sdp->exclude = 0;       /* undo if error */
297                         wake_up_interruptible(&sdp->o_excl_wait);
298                 }
299                 retval = -ENOMEM;
300                 goto error_out;
301         }
302         retval = 0;
303 error_out:
304         if (retval)
305                 scsi_device_put(sdp->device);
306 sg_put:
307         if (sdp)
308                 sg_put_dev(sdp);
309         unlock_kernel();
310         return retval;
311 }
312
313 /* Following function was formerly called 'sg_close' */
314 static int
315 sg_release(struct inode *inode, struct file *filp)
316 {
317         Sg_device *sdp;
318         Sg_fd *sfp;
319
320         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
321                 return -ENXIO;
322         SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
323
324         sfp->closed = 1;
325
326         sdp->exclude = 0;
327         wake_up_interruptible(&sdp->o_excl_wait);
328
329         kref_put(&sfp->f_ref, sg_remove_sfp);
330         return 0;
331 }
332
333 static ssize_t
334 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
335 {
336         Sg_device *sdp;
337         Sg_fd *sfp;
338         Sg_request *srp;
339         int req_pack_id = -1;
340         sg_io_hdr_t *hp;
341         struct sg_header *old_hdr = NULL;
342         int retval = 0;
343
344         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
345                 return -ENXIO;
346         SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
347                                    sdp->disk->disk_name, (int) count));
348
349         if (!access_ok(VERIFY_WRITE, buf, count))
350                 return -EFAULT;
351         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
352                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
353                 if (!old_hdr)
354                         return -ENOMEM;
355                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
356                         retval = -EFAULT;
357                         goto free_old_hdr;
358                 }
359                 if (old_hdr->reply_len < 0) {
360                         if (count >= SZ_SG_IO_HDR) {
361                                 sg_io_hdr_t *new_hdr;
362                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
363                                 if (!new_hdr) {
364                                         retval = -ENOMEM;
365                                         goto free_old_hdr;
366                                 }
367                                 retval =__copy_from_user
368                                     (new_hdr, buf, SZ_SG_IO_HDR);
369                                 req_pack_id = new_hdr->pack_id;
370                                 kfree(new_hdr);
371                                 if (retval) {
372                                         retval = -EFAULT;
373                                         goto free_old_hdr;
374                                 }
375                         }
376                 } else
377                         req_pack_id = old_hdr->pack_id;
378         }
379         srp = sg_get_rq_mark(sfp, req_pack_id);
380         if (!srp) {             /* now wait on packet to arrive */
381                 if (sdp->detached) {
382                         retval = -ENODEV;
383                         goto free_old_hdr;
384                 }
385                 if (filp->f_flags & O_NONBLOCK) {
386                         retval = -EAGAIN;
387                         goto free_old_hdr;
388                 }
389                 while (1) {
390                         retval = 0; /* following macro beats race condition */
391                         __wait_event_interruptible(sfp->read_wait,
392                                 (sdp->detached ||
393                                 (srp = sg_get_rq_mark(sfp, req_pack_id))), 
394                                 retval);
395                         if (sdp->detached) {
396                                 retval = -ENODEV;
397                                 goto free_old_hdr;
398                         }
399                         if (0 == retval)
400                                 break;
401
402                         /* -ERESTARTSYS as signal hit process */
403                         goto free_old_hdr;
404                 }
405         }
406         if (srp->header.interface_id != '\0') {
407                 retval = sg_new_read(sfp, buf, count, srp);
408                 goto free_old_hdr;
409         }
410
411         hp = &srp->header;
412         if (old_hdr == NULL) {
413                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
414                 if (! old_hdr) {
415                         retval = -ENOMEM;
416                         goto free_old_hdr;
417                 }
418         }
419         memset(old_hdr, 0, SZ_SG_HEADER);
420         old_hdr->reply_len = (int) hp->timeout;
421         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
422         old_hdr->pack_id = hp->pack_id;
423         old_hdr->twelve_byte =
424             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
425         old_hdr->target_status = hp->masked_status;
426         old_hdr->host_status = hp->host_status;
427         old_hdr->driver_status = hp->driver_status;
428         if ((CHECK_CONDITION & hp->masked_status) ||
429             (DRIVER_SENSE & hp->driver_status))
430                 memcpy(old_hdr->sense_buffer, srp->sense_b,
431                        sizeof (old_hdr->sense_buffer));
432         switch (hp->host_status) {
433         /* This setup of 'result' is for backward compatibility and is best
434            ignored by the user who should use target, host + driver status */
435         case DID_OK:
436         case DID_PASSTHROUGH:
437         case DID_SOFT_ERROR:
438                 old_hdr->result = 0;
439                 break;
440         case DID_NO_CONNECT:
441         case DID_BUS_BUSY:
442         case DID_TIME_OUT:
443                 old_hdr->result = EBUSY;
444                 break;
445         case DID_BAD_TARGET:
446         case DID_ABORT:
447         case DID_PARITY:
448         case DID_RESET:
449         case DID_BAD_INTR:
450                 old_hdr->result = EIO;
451                 break;
452         case DID_ERROR:
453                 old_hdr->result = (srp->sense_b[0] == 0 && 
454                                   hp->masked_status == GOOD) ? 0 : EIO;
455                 break;
456         default:
457                 old_hdr->result = EIO;
458                 break;
459         }
460
461         /* Now copy the result back to the user buffer.  */
462         if (count >= SZ_SG_HEADER) {
463                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
464                         retval = -EFAULT;
465                         goto free_old_hdr;
466                 }
467                 buf += SZ_SG_HEADER;
468                 if (count > old_hdr->reply_len)
469                         count = old_hdr->reply_len;
470                 if (count > SZ_SG_HEADER) {
471                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
472                                 retval = -EFAULT;
473                                 goto free_old_hdr;
474                         }
475                 }
476         } else
477                 count = (old_hdr->result == 0) ? 0 : -EIO;
478         sg_finish_rem_req(srp);
479         retval = count;
480 free_old_hdr:
481         kfree(old_hdr);
482         return retval;
483 }
484
485 static ssize_t
486 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
487 {
488         sg_io_hdr_t *hp = &srp->header;
489         int err = 0;
490         int len;
491
492         if (count < SZ_SG_IO_HDR) {
493                 err = -EINVAL;
494                 goto err_out;
495         }
496         hp->sb_len_wr = 0;
497         if ((hp->mx_sb_len > 0) && hp->sbp) {
498                 if ((CHECK_CONDITION & hp->masked_status) ||
499                     (DRIVER_SENSE & hp->driver_status)) {
500                         int sb_len = SCSI_SENSE_BUFFERSIZE;
501                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
502                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
503                         len = (len > sb_len) ? sb_len : len;
504                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
505                                 err = -EFAULT;
506                                 goto err_out;
507                         }
508                         hp->sb_len_wr = len;
509                 }
510         }
511         if (hp->masked_status || hp->host_status || hp->driver_status)
512                 hp->info |= SG_INFO_CHECK;
513         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
514                 err = -EFAULT;
515                 goto err_out;
516         }
517 err_out:
518         err = sg_finish_rem_req(srp);
519         return (0 == err) ? count : err;
520 }
521
522 static ssize_t
523 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
524 {
525         int mxsize, cmd_size, k;
526         int input_size, blocking;
527         unsigned char opcode;
528         Sg_device *sdp;
529         Sg_fd *sfp;
530         Sg_request *srp;
531         struct sg_header old_hdr;
532         sg_io_hdr_t *hp;
533         unsigned char cmnd[MAX_COMMAND_SIZE];
534
535         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
536                 return -ENXIO;
537         SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
538                                    sdp->disk->disk_name, (int) count));
539         if (sdp->detached)
540                 return -ENODEV;
541         if (!((filp->f_flags & O_NONBLOCK) ||
542               scsi_block_when_processing_errors(sdp->device)))
543                 return -ENXIO;
544
545         if (!access_ok(VERIFY_READ, buf, count))
546                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
547         if (count < SZ_SG_HEADER)
548                 return -EIO;
549         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
550                 return -EFAULT;
551         blocking = !(filp->f_flags & O_NONBLOCK);
552         if (old_hdr.reply_len < 0)
553                 return sg_new_write(sfp, filp, buf, count,
554                                     blocking, 0, 0, NULL);
555         if (count < (SZ_SG_HEADER + 6))
556                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
557
558         if (!(srp = sg_add_request(sfp))) {
559                 SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
560                 return -EDOM;
561         }
562         buf += SZ_SG_HEADER;
563         __get_user(opcode, buf);
564         if (sfp->next_cmd_len > 0) {
565                 if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
566                         SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
567                         sfp->next_cmd_len = 0;
568                         sg_remove_request(sfp, srp);
569                         return -EIO;
570                 }
571                 cmd_size = sfp->next_cmd_len;
572                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
573         } else {
574                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
575                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
576                         cmd_size = 12;
577         }
578         SCSI_LOG_TIMEOUT(4, printk(
579                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
580 /* Determine buffer size.  */
581         input_size = count - cmd_size;
582         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
583         mxsize -= SZ_SG_HEADER;
584         input_size -= SZ_SG_HEADER;
585         if (input_size < 0) {
586                 sg_remove_request(sfp, srp);
587                 return -EIO;    /* User did not pass enough bytes for this command. */
588         }
589         hp = &srp->header;
590         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
591         hp->cmd_len = (unsigned char) cmd_size;
592         hp->iovec_count = 0;
593         hp->mx_sb_len = 0;
594         if (input_size > 0)
595                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
596                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
597         else
598                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
599         hp->dxfer_len = mxsize;
600         if (hp->dxfer_direction == SG_DXFER_TO_DEV)
601                 hp->dxferp = (char __user *)buf + cmd_size;
602         else
603                 hp->dxferp = NULL;
604         hp->sbp = NULL;
605         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
606         hp->flags = input_size; /* structure abuse ... */
607         hp->pack_id = old_hdr.pack_id;
608         hp->usr_ptr = NULL;
609         if (__copy_from_user(cmnd, buf, cmd_size))
610                 return -EFAULT;
611         /*
612          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
613          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
614          * is a non-zero input_size, so emit a warning.
615          */
616         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
617                 static char cmd[TASK_COMM_LEN];
618                 if (strcmp(current->comm, cmd) && printk_ratelimit()) {
619                         printk(KERN_WARNING
620                                "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
621                                "guessing data in;\n   "
622                                "program %s not setting count and/or reply_len properly\n",
623                                old_hdr.reply_len - (int)SZ_SG_HEADER,
624                                input_size, (unsigned int) cmnd[0],
625                                current->comm);
626                         strcpy(cmd, current->comm);
627                 }
628         }
629         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
630         return (k < 0) ? k : count;
631 }
632
633 static ssize_t
634 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
635                  size_t count, int blocking, int read_only, int sg_io_owned,
636                  Sg_request **o_srp)
637 {
638         int k;
639         Sg_request *srp;
640         sg_io_hdr_t *hp;
641         unsigned char cmnd[MAX_COMMAND_SIZE];
642         int timeout;
643         unsigned long ul_timeout;
644
645         if (count < SZ_SG_IO_HDR)
646                 return -EINVAL;
647         if (!access_ok(VERIFY_READ, buf, count))
648                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
649
650         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
651         if (!(srp = sg_add_request(sfp))) {
652                 SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
653                 return -EDOM;
654         }
655         srp->sg_io_owned = sg_io_owned;
656         hp = &srp->header;
657         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
658                 sg_remove_request(sfp, srp);
659                 return -EFAULT;
660         }
661         if (hp->interface_id != 'S') {
662                 sg_remove_request(sfp, srp);
663                 return -ENOSYS;
664         }
665         if (hp->flags & SG_FLAG_MMAP_IO) {
666                 if (hp->dxfer_len > sfp->reserve.bufflen) {
667                         sg_remove_request(sfp, srp);
668                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
669                 }
670                 if (hp->flags & SG_FLAG_DIRECT_IO) {
671                         sg_remove_request(sfp, srp);
672                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
673                 }
674                 if (sg_res_in_use(sfp)) {
675                         sg_remove_request(sfp, srp);
676                         return -EBUSY;  /* reserve buffer already being used */
677                 }
678         }
679         ul_timeout = msecs_to_jiffies(srp->header.timeout);
680         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
681         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
682                 sg_remove_request(sfp, srp);
683                 return -EMSGSIZE;
684         }
685         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
686                 sg_remove_request(sfp, srp);
687                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
688         }
689         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
690                 sg_remove_request(sfp, srp);
691                 return -EFAULT;
692         }
693         if (read_only && sg_allow_access(file, cmnd)) {
694                 sg_remove_request(sfp, srp);
695                 return -EPERM;
696         }
697         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
698         if (k < 0)
699                 return k;
700         if (o_srp)
701                 *o_srp = srp;
702         return count;
703 }
704
705 static int
706 sg_common_write(Sg_fd * sfp, Sg_request * srp,
707                 unsigned char *cmnd, int timeout, int blocking)
708 {
709         int k, data_dir;
710         Sg_device *sdp = sfp->parentdp;
711         sg_io_hdr_t *hp = &srp->header;
712
713         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
714         hp->status = 0;
715         hp->masked_status = 0;
716         hp->msg_status = 0;
717         hp->info = 0;
718         hp->host_status = 0;
719         hp->driver_status = 0;
720         hp->resid = 0;
721         SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
722                           (int) cmnd[0], (int) hp->cmd_len));
723
724         k = sg_start_req(srp, cmnd);
725         if (k) {
726                 SCSI_LOG_TIMEOUT(1, printk("sg_common_write: start_req err=%d\n", k));
727                 sg_finish_rem_req(srp);
728                 return k;       /* probably out of space --> ENOMEM */
729         }
730         if (sdp->detached) {
731                 sg_finish_rem_req(srp);
732                 return -ENODEV;
733         }
734
735         switch (hp->dxfer_direction) {
736         case SG_DXFER_TO_FROM_DEV:
737         case SG_DXFER_FROM_DEV:
738                 data_dir = DMA_FROM_DEVICE;
739                 break;
740         case SG_DXFER_TO_DEV:
741                 data_dir = DMA_TO_DEVICE;
742                 break;
743         case SG_DXFER_UNKNOWN:
744                 data_dir = DMA_BIDIRECTIONAL;
745                 break;
746         default:
747                 data_dir = DMA_NONE;
748                 break;
749         }
750         hp->duration = jiffies_to_msecs(jiffies);
751
752         srp->rq->timeout = timeout;
753         kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
754         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
755                               srp->rq, 1, sg_rq_end_io);
756         return 0;
757 }
758
759 static int
760 sg_ioctl(struct inode *inode, struct file *filp,
761          unsigned int cmd_in, unsigned long arg)
762 {
763         void __user *p = (void __user *)arg;
764         int __user *ip = p;
765         int result, val, read_only;
766         Sg_device *sdp;
767         Sg_fd *sfp;
768         Sg_request *srp;
769         unsigned long iflags;
770
771         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
772                 return -ENXIO;
773
774         SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
775                                    sdp->disk->disk_name, (int) cmd_in));
776         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
777
778         switch (cmd_in) {
779         case SG_IO:
780                 {
781                         int blocking = 1;       /* ignore O_NONBLOCK flag */
782
783                         if (sdp->detached)
784                                 return -ENODEV;
785                         if (!scsi_block_when_processing_errors(sdp->device))
786                                 return -ENXIO;
787                         if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
788                                 return -EFAULT;
789                         result =
790                             sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
791                                          blocking, read_only, 1, &srp);
792                         if (result < 0)
793                                 return result;
794                         while (1) {
795                                 result = 0;     /* following macro to beat race condition */
796                                 __wait_event_interruptible(sfp->read_wait,
797                                         (srp->done || sdp->detached),
798                                         result);
799                                 if (sdp->detached)
800                                         return -ENODEV;
801                                 write_lock_irq(&sfp->rq_list_lock);
802                                 if (srp->done) {
803                                         srp->done = 2;
804                                         write_unlock_irq(&sfp->rq_list_lock);
805                                         break;
806                                 }
807                                 srp->orphan = 1;
808                                 write_unlock_irq(&sfp->rq_list_lock);
809                                 return result;  /* -ERESTARTSYS because signal hit process */
810                         }
811                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
812                         return (result < 0) ? result : 0;
813                 }
814         case SG_SET_TIMEOUT:
815                 result = get_user(val, ip);
816                 if (result)
817                         return result;
818                 if (val < 0)
819                         return -EIO;
820                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
821                     val = MULDIV (INT_MAX, USER_HZ, HZ);
822                 sfp->timeout_user = val;
823                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
824
825                 return 0;
826         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
827                                 /* strange ..., for backward compatibility */
828                 return sfp->timeout_user;
829         case SG_SET_FORCE_LOW_DMA:
830                 result = get_user(val, ip);
831                 if (result)
832                         return result;
833                 if (val) {
834                         sfp->low_dma = 1;
835                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
836                                 val = (int) sfp->reserve.bufflen;
837                                 sg_remove_scat(&sfp->reserve);
838                                 sg_build_reserve(sfp, val);
839                         }
840                 } else {
841                         if (sdp->detached)
842                                 return -ENODEV;
843                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
844                 }
845                 return 0;
846         case SG_GET_LOW_DMA:
847                 return put_user((int) sfp->low_dma, ip);
848         case SG_GET_SCSI_ID:
849                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
850                         return -EFAULT;
851                 else {
852                         sg_scsi_id_t __user *sg_idp = p;
853
854                         if (sdp->detached)
855                                 return -ENODEV;
856                         __put_user((int) sdp->device->host->host_no,
857                                    &sg_idp->host_no);
858                         __put_user((int) sdp->device->channel,
859                                    &sg_idp->channel);
860                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
861                         __put_user((int) sdp->device->lun, &sg_idp->lun);
862                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
863                         __put_user((short) sdp->device->host->cmd_per_lun,
864                                    &sg_idp->h_cmd_per_lun);
865                         __put_user((short) sdp->device->queue_depth,
866                                    &sg_idp->d_queue_depth);
867                         __put_user(0, &sg_idp->unused[0]);
868                         __put_user(0, &sg_idp->unused[1]);
869                         return 0;
870                 }
871         case SG_SET_FORCE_PACK_ID:
872                 result = get_user(val, ip);
873                 if (result)
874                         return result;
875                 sfp->force_packid = val ? 1 : 0;
876                 return 0;
877         case SG_GET_PACK_ID:
878                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
879                         return -EFAULT;
880                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
881                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
882                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
883                                 read_unlock_irqrestore(&sfp->rq_list_lock,
884                                                        iflags);
885                                 __put_user(srp->header.pack_id, ip);
886                                 return 0;
887                         }
888                 }
889                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
890                 __put_user(-1, ip);
891                 return 0;
892         case SG_GET_NUM_WAITING:
893                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
894                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
895                         if ((1 == srp->done) && (!srp->sg_io_owned))
896                                 ++val;
897                 }
898                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
899                 return put_user(val, ip);
900         case SG_GET_SG_TABLESIZE:
901                 return put_user(sdp->sg_tablesize, ip);
902         case SG_SET_RESERVED_SIZE:
903                 result = get_user(val, ip);
904                 if (result)
905                         return result;
906                 if (val < 0)
907                         return -EINVAL;
908                 val = min_t(int, val,
909                             queue_max_sectors(sdp->device->request_queue) * 512);
910                 if (val != sfp->reserve.bufflen) {
911                         if (sg_res_in_use(sfp) || sfp->mmap_called)
912                                 return -EBUSY;
913                         sg_remove_scat(&sfp->reserve);
914                         sg_build_reserve(sfp, val);
915                 }
916                 return 0;
917         case SG_GET_RESERVED_SIZE:
918                 val = min_t(int, sfp->reserve.bufflen,
919                             queue_max_sectors(sdp->device->request_queue) * 512);
920                 return put_user(val, ip);
921         case SG_SET_COMMAND_Q:
922                 result = get_user(val, ip);
923                 if (result)
924                         return result;
925                 sfp->cmd_q = val ? 1 : 0;
926                 return 0;
927         case SG_GET_COMMAND_Q:
928                 return put_user((int) sfp->cmd_q, ip);
929         case SG_SET_KEEP_ORPHAN:
930                 result = get_user(val, ip);
931                 if (result)
932                         return result;
933                 sfp->keep_orphan = val;
934                 return 0;
935         case SG_GET_KEEP_ORPHAN:
936                 return put_user((int) sfp->keep_orphan, ip);
937         case SG_NEXT_CMD_LEN:
938                 result = get_user(val, ip);
939                 if (result)
940                         return result;
941                 sfp->next_cmd_len = (val > 0) ? val : 0;
942                 return 0;
943         case SG_GET_VERSION_NUM:
944                 return put_user(sg_version_num, ip);
945         case SG_GET_ACCESS_COUNT:
946                 /* faked - we don't have a real access count anymore */
947                 val = (sdp->device ? 1 : 0);
948                 return put_user(val, ip);
949         case SG_GET_REQUEST_TABLE:
950                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
951                         return -EFAULT;
952                 else {
953                         sg_req_info_t *rinfo;
954                         unsigned int ms;
955
956                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
957                                                                 GFP_KERNEL);
958                         if (!rinfo)
959                                 return -ENOMEM;
960                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
961                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
962                              ++val, srp = srp ? srp->nextrp : srp) {
963                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
964                                 if (srp) {
965                                         rinfo[val].req_state = srp->done + 1;
966                                         rinfo[val].problem =
967                                             srp->header.masked_status & 
968                                             srp->header.host_status & 
969                                             srp->header.driver_status;
970                                         if (srp->done)
971                                                 rinfo[val].duration =
972                                                         srp->header.duration;
973                                         else {
974                                                 ms = jiffies_to_msecs(jiffies);
975                                                 rinfo[val].duration =
976                                                     (ms > srp->header.duration) ?
977                                                     (ms - srp->header.duration) : 0;
978                                         }
979                                         rinfo[val].orphan = srp->orphan;
980                                         rinfo[val].sg_io_owned =
981                                                         srp->sg_io_owned;
982                                         rinfo[val].pack_id =
983                                                         srp->header.pack_id;
984                                         rinfo[val].usr_ptr =
985                                                         srp->header.usr_ptr;
986                                 }
987                         }
988                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
989                         result = __copy_to_user(p, rinfo, 
990                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
991                         result = result ? -EFAULT : 0;
992                         kfree(rinfo);
993                         return result;
994                 }
995         case SG_EMULATED_HOST:
996                 if (sdp->detached)
997                         return -ENODEV;
998                 return put_user(sdp->device->host->hostt->emulated, ip);
999         case SG_SCSI_RESET:
1000                 if (sdp->detached)
1001                         return -ENODEV;
1002                 if (filp->f_flags & O_NONBLOCK) {
1003                         if (scsi_host_in_recovery(sdp->device->host))
1004                                 return -EBUSY;
1005                 } else if (!scsi_block_when_processing_errors(sdp->device))
1006                         return -EBUSY;
1007                 result = get_user(val, ip);
1008                 if (result)
1009                         return result;
1010                 if (SG_SCSI_RESET_NOTHING == val)
1011                         return 0;
1012                 switch (val) {
1013                 case SG_SCSI_RESET_DEVICE:
1014                         val = SCSI_TRY_RESET_DEVICE;
1015                         break;
1016                 case SG_SCSI_RESET_TARGET:
1017                         val = SCSI_TRY_RESET_TARGET;
1018                         break;
1019                 case SG_SCSI_RESET_BUS:
1020                         val = SCSI_TRY_RESET_BUS;
1021                         break;
1022                 case SG_SCSI_RESET_HOST:
1023                         val = SCSI_TRY_RESET_HOST;
1024                         break;
1025                 default:
1026                         return -EINVAL;
1027                 }
1028                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1029                         return -EACCES;
1030                 return (scsi_reset_provider(sdp->device, val) ==
1031                         SUCCESS) ? 0 : -EIO;
1032         case SCSI_IOCTL_SEND_COMMAND:
1033                 if (sdp->detached)
1034                         return -ENODEV;
1035                 if (read_only) {
1036                         unsigned char opcode = WRITE_6;
1037                         Scsi_Ioctl_Command __user *siocp = p;
1038
1039                         if (copy_from_user(&opcode, siocp->data, 1))
1040                                 return -EFAULT;
1041                         if (sg_allow_access(filp, &opcode))
1042                                 return -EPERM;
1043                 }
1044                 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1045         case SG_SET_DEBUG:
1046                 result = get_user(val, ip);
1047                 if (result)
1048                         return result;
1049                 sdp->sgdebug = (char) val;
1050                 return 0;
1051         case SCSI_IOCTL_GET_IDLUN:
1052         case SCSI_IOCTL_GET_BUS_NUMBER:
1053         case SCSI_IOCTL_PROBE_HOST:
1054         case SG_GET_TRANSFORM:
1055                 if (sdp->detached)
1056                         return -ENODEV;
1057                 return scsi_ioctl(sdp->device, cmd_in, p);
1058         case BLKSECTGET:
1059                 return put_user(queue_max_sectors(sdp->device->request_queue) * 512,
1060                                 ip);
1061         case BLKTRACESETUP:
1062                 return blk_trace_setup(sdp->device->request_queue,
1063                                        sdp->disk->disk_name,
1064                                        MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1065                                        NULL,
1066                                        (char *)arg);
1067         case BLKTRACESTART:
1068                 return blk_trace_startstop(sdp->device->request_queue, 1);
1069         case BLKTRACESTOP:
1070                 return blk_trace_startstop(sdp->device->request_queue, 0);
1071         case BLKTRACETEARDOWN:
1072                 return blk_trace_remove(sdp->device->request_queue);
1073         default:
1074                 if (read_only)
1075                         return -EPERM;  /* don't know so take safe approach */
1076                 return scsi_ioctl(sdp->device, cmd_in, p);
1077         }
1078 }
1079
1080 #ifdef CONFIG_COMPAT
1081 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1082 {
1083         Sg_device *sdp;
1084         Sg_fd *sfp;
1085         struct scsi_device *sdev;
1086
1087         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1088                 return -ENXIO;
1089
1090         sdev = sdp->device;
1091         if (sdev->host->hostt->compat_ioctl) { 
1092                 int ret;
1093
1094                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1095
1096                 return ret;
1097         }
1098         
1099         return -ENOIOCTLCMD;
1100 }
1101 #endif
1102
1103 static unsigned int
1104 sg_poll(struct file *filp, poll_table * wait)
1105 {
1106         unsigned int res = 0;
1107         Sg_device *sdp;
1108         Sg_fd *sfp;
1109         Sg_request *srp;
1110         int count = 0;
1111         unsigned long iflags;
1112
1113         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1114             || sfp->closed)
1115                 return POLLERR;
1116         poll_wait(filp, &sfp->read_wait, wait);
1117         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1118         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1119                 /* if any read waiting, flag it */
1120                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1121                         res = POLLIN | POLLRDNORM;
1122                 ++count;
1123         }
1124         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1125
1126         if (sdp->detached)
1127                 res |= POLLHUP;
1128         else if (!sfp->cmd_q) {
1129                 if (0 == count)
1130                         res |= POLLOUT | POLLWRNORM;
1131         } else if (count < SG_MAX_QUEUE)
1132                 res |= POLLOUT | POLLWRNORM;
1133         SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1134                                    sdp->disk->disk_name, (int) res));
1135         return res;
1136 }
1137
1138 static int
1139 sg_fasync(int fd, struct file *filp, int mode)
1140 {
1141         Sg_device *sdp;
1142         Sg_fd *sfp;
1143
1144         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1145                 return -ENXIO;
1146         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1147                                    sdp->disk->disk_name, mode));
1148
1149         return fasync_helper(fd, filp, mode, &sfp->async_qp);
1150 }
1151
1152 static int
1153 sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1154 {
1155         Sg_fd *sfp;
1156         unsigned long offset, len, sa;
1157         Sg_scatter_hold *rsv_schp;
1158         int k, length;
1159
1160         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1161                 return VM_FAULT_SIGBUS;
1162         rsv_schp = &sfp->reserve;
1163         offset = vmf->pgoff << PAGE_SHIFT;
1164         if (offset >= rsv_schp->bufflen)
1165                 return VM_FAULT_SIGBUS;
1166         SCSI_LOG_TIMEOUT(3, printk("sg_vma_fault: offset=%lu, scatg=%d\n",
1167                                    offset, rsv_schp->k_use_sg));
1168         sa = vma->vm_start;
1169         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1170         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1171                 len = vma->vm_end - sa;
1172                 len = (len < length) ? len : length;
1173                 if (offset < len) {
1174                         struct page *page = nth_page(rsv_schp->pages[k],
1175                                                      offset >> PAGE_SHIFT);
1176                         get_page(page); /* increment page count */
1177                         vmf->page = page;
1178                         return 0; /* success */
1179                 }
1180                 sa += len;
1181                 offset -= len;
1182         }
1183
1184         return VM_FAULT_SIGBUS;
1185 }
1186
1187 static const struct vm_operations_struct sg_mmap_vm_ops = {
1188         .fault = sg_vma_fault,
1189 };
1190
1191 static int
1192 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1193 {
1194         Sg_fd *sfp;
1195         unsigned long req_sz, len, sa;
1196         Sg_scatter_hold *rsv_schp;
1197         int k, length;
1198
1199         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1200                 return -ENXIO;
1201         req_sz = vma->vm_end - vma->vm_start;
1202         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1203                                    (void *) vma->vm_start, (int) req_sz));
1204         if (vma->vm_pgoff)
1205                 return -EINVAL; /* want no offset */
1206         rsv_schp = &sfp->reserve;
1207         if (req_sz > rsv_schp->bufflen)
1208                 return -ENOMEM; /* cannot map more than reserved buffer */
1209
1210         sa = vma->vm_start;
1211         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1212         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1213                 len = vma->vm_end - sa;
1214                 len = (len < length) ? len : length;
1215                 sa += len;
1216         }
1217
1218         sfp->mmap_called = 1;
1219         vma->vm_flags |= VM_RESERVED;
1220         vma->vm_private_data = sfp;
1221         vma->vm_ops = &sg_mmap_vm_ops;
1222         return 0;
1223 }
1224
1225 static void sg_rq_end_io_usercontext(struct work_struct *work)
1226 {
1227         struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1228         struct sg_fd *sfp = srp->parentfp;
1229
1230         sg_finish_rem_req(srp);
1231         kref_put(&sfp->f_ref, sg_remove_sfp);
1232 }
1233
1234 /*
1235  * This function is a "bottom half" handler that is called by the mid
1236  * level when a command is completed (or has failed).
1237  */
1238 static void sg_rq_end_io(struct request *rq, int uptodate)
1239 {
1240         struct sg_request *srp = rq->end_io_data;
1241         Sg_device *sdp;
1242         Sg_fd *sfp;
1243         unsigned long iflags;
1244         unsigned int ms;
1245         char *sense;
1246         int result, resid, done = 1;
1247
1248         if (WARN_ON(srp->done != 0))
1249                 return;
1250
1251         sfp = srp->parentfp;
1252         if (WARN_ON(sfp == NULL))
1253                 return;
1254
1255         sdp = sfp->parentdp;
1256         if (unlikely(sdp->detached))
1257                 printk(KERN_INFO "sg_rq_end_io: device detached\n");
1258
1259         sense = rq->sense;
1260         result = rq->errors;
1261         resid = rq->resid_len;
1262
1263         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1264                 sdp->disk->disk_name, srp->header.pack_id, result));
1265         srp->header.resid = resid;
1266         ms = jiffies_to_msecs(jiffies);
1267         srp->header.duration = (ms > srp->header.duration) ?
1268                                 (ms - srp->header.duration) : 0;
1269         if (0 != result) {
1270                 struct scsi_sense_hdr sshdr;
1271
1272                 srp->header.status = 0xff & result;
1273                 srp->header.masked_status = status_byte(result);
1274                 srp->header.msg_status = msg_byte(result);
1275                 srp->header.host_status = host_byte(result);
1276                 srp->header.driver_status = driver_byte(result);
1277                 if ((sdp->sgdebug > 0) &&
1278                     ((CHECK_CONDITION == srp->header.masked_status) ||
1279                      (COMMAND_TERMINATED == srp->header.masked_status)))
1280                         __scsi_print_sense("sg_cmd_done", sense,
1281                                            SCSI_SENSE_BUFFERSIZE);
1282
1283                 /* Following if statement is a patch supplied by Eric Youngdale */
1284                 if (driver_byte(result) != 0
1285                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1286                     && !scsi_sense_is_deferred(&sshdr)
1287                     && sshdr.sense_key == UNIT_ATTENTION
1288                     && sdp->device->removable) {
1289                         /* Detected possible disc change. Set the bit - this */
1290                         /* may be used if there are filesystems using this device */
1291                         sdp->device->changed = 1;
1292                 }
1293         }
1294         /* Rely on write phase to clean out srp status values, so no "else" */
1295
1296         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1297         if (unlikely(srp->orphan)) {
1298                 if (sfp->keep_orphan)
1299                         srp->sg_io_owned = 0;
1300                 else
1301                         done = 0;
1302         }
1303         srp->done = done;
1304         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1305
1306         if (likely(done)) {
1307                 /* Now wake up any sg_read() that is waiting for this
1308                  * packet.
1309                  */
1310                 wake_up_interruptible(&sfp->read_wait);
1311                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1312                 kref_put(&sfp->f_ref, sg_remove_sfp);
1313         } else {
1314                 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1315                 schedule_work(&srp->ew.work);
1316         }
1317 }
1318
1319 static const struct file_operations sg_fops = {
1320         .owner = THIS_MODULE,
1321         .read = sg_read,
1322         .write = sg_write,
1323         .poll = sg_poll,
1324         .ioctl = sg_ioctl,
1325 #ifdef CONFIG_COMPAT
1326         .compat_ioctl = sg_compat_ioctl,
1327 #endif
1328         .open = sg_open,
1329         .mmap = sg_mmap,
1330         .release = sg_release,
1331         .fasync = sg_fasync,
1332 };
1333
1334 static struct class *sg_sysfs_class;
1335
1336 static int sg_sysfs_valid = 0;
1337
1338 static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1339 {
1340         struct request_queue *q = scsidp->request_queue;
1341         Sg_device *sdp;
1342         unsigned long iflags;
1343         int error;
1344         u32 k;
1345
1346         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1347         if (!sdp) {
1348                 printk(KERN_WARNING "kmalloc Sg_device failure\n");
1349                 return ERR_PTR(-ENOMEM);
1350         }
1351
1352         if (!idr_pre_get(&sg_index_idr, GFP_KERNEL)) {
1353                 printk(KERN_WARNING "idr expansion Sg_device failure\n");
1354                 error = -ENOMEM;
1355                 goto out;
1356         }
1357
1358         write_lock_irqsave(&sg_index_lock, iflags);
1359
1360         error = idr_get_new(&sg_index_idr, sdp, &k);
1361         if (error) {
1362                 write_unlock_irqrestore(&sg_index_lock, iflags);
1363                 printk(KERN_WARNING "idr allocation Sg_device failure: %d\n",
1364                        error);
1365                 goto out;
1366         }
1367
1368         if (unlikely(k >= SG_MAX_DEVS))
1369                 goto overflow;
1370
1371         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1372         sprintf(disk->disk_name, "sg%d", k);
1373         disk->first_minor = k;
1374         sdp->disk = disk;
1375         sdp->device = scsidp;
1376         INIT_LIST_HEAD(&sdp->sfds);
1377         init_waitqueue_head(&sdp->o_excl_wait);
1378         sdp->sg_tablesize = queue_max_segments(q);
1379         sdp->index = k;
1380         kref_init(&sdp->d_ref);
1381
1382         write_unlock_irqrestore(&sg_index_lock, iflags);
1383
1384         error = 0;
1385  out:
1386         if (error) {
1387                 kfree(sdp);
1388                 return ERR_PTR(error);
1389         }
1390         return sdp;
1391
1392  overflow:
1393         idr_remove(&sg_index_idr, k);
1394         write_unlock_irqrestore(&sg_index_lock, iflags);
1395         sdev_printk(KERN_WARNING, scsidp,
1396                     "Unable to attach sg device type=%d, minor "
1397                     "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1398         error = -ENODEV;
1399         goto out;
1400 }
1401
1402 static int
1403 sg_add(struct device *cl_dev, struct class_interface *cl_intf)
1404 {
1405         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1406         struct gendisk *disk;
1407         Sg_device *sdp = NULL;
1408         struct cdev * cdev = NULL;
1409         int error;
1410         unsigned long iflags;
1411
1412         disk = alloc_disk(1);
1413         if (!disk) {
1414                 printk(KERN_WARNING "alloc_disk failed\n");
1415                 return -ENOMEM;
1416         }
1417         disk->major = SCSI_GENERIC_MAJOR;
1418
1419         error = -ENOMEM;
1420         cdev = cdev_alloc();
1421         if (!cdev) {
1422                 printk(KERN_WARNING "cdev_alloc failed\n");
1423                 goto out;
1424         }
1425         cdev->owner = THIS_MODULE;
1426         cdev->ops = &sg_fops;
1427
1428         sdp = sg_alloc(disk, scsidp);
1429         if (IS_ERR(sdp)) {
1430                 printk(KERN_WARNING "sg_alloc failed\n");
1431                 error = PTR_ERR(sdp);
1432                 goto out;
1433         }
1434
1435         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1436         if (error)
1437                 goto cdev_add_err;
1438
1439         sdp->cdev = cdev;
1440         if (sg_sysfs_valid) {
1441                 struct device *sg_class_member;
1442
1443                 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1444                                                 MKDEV(SCSI_GENERIC_MAJOR,
1445                                                       sdp->index),
1446                                                 sdp, "%s", disk->disk_name);
1447                 if (IS_ERR(sg_class_member)) {
1448                         printk(KERN_ERR "sg_add: "
1449                                "device_create failed\n");
1450                         error = PTR_ERR(sg_class_member);
1451                         goto cdev_add_err;
1452                 }
1453                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1454                                           &sg_class_member->kobj, "generic");
1455                 if (error)
1456                         printk(KERN_ERR "sg_add: unable to make symlink "
1457                                         "'generic' back to sg%d\n", sdp->index);
1458         } else
1459                 printk(KERN_WARNING "sg_add: sg_sys Invalid\n");
1460
1461         sdev_printk(KERN_NOTICE, scsidp,
1462                     "Attached scsi generic sg%d type %d\n", sdp->index,
1463                     scsidp->type);
1464
1465         dev_set_drvdata(cl_dev, sdp);
1466
1467         return 0;
1468
1469 cdev_add_err:
1470         write_lock_irqsave(&sg_index_lock, iflags);
1471         idr_remove(&sg_index_idr, sdp->index);
1472         write_unlock_irqrestore(&sg_index_lock, iflags);
1473         kfree(sdp);
1474
1475 out:
1476         put_disk(disk);
1477         if (cdev)
1478                 cdev_del(cdev);
1479         return error;
1480 }
1481
1482 static void sg_device_destroy(struct kref *kref)
1483 {
1484         struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1485         unsigned long flags;
1486
1487         /* CAUTION!  Note that the device can still be found via idr_find()
1488          * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1489          * any other cleanup.
1490          */
1491
1492         write_lock_irqsave(&sg_index_lock, flags);
1493         idr_remove(&sg_index_idr, sdp->index);
1494         write_unlock_irqrestore(&sg_index_lock, flags);
1495
1496         SCSI_LOG_TIMEOUT(3,
1497                 printk("sg_device_destroy: %s\n",
1498                         sdp->disk->disk_name));
1499
1500         put_disk(sdp->disk);
1501         kfree(sdp);
1502 }
1503
1504 static void sg_remove(struct device *cl_dev, struct class_interface *cl_intf)
1505 {
1506         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1507         Sg_device *sdp = dev_get_drvdata(cl_dev);
1508         unsigned long iflags;
1509         Sg_fd *sfp;
1510
1511         if (!sdp || sdp->detached)
1512                 return;
1513
1514         SCSI_LOG_TIMEOUT(3, printk("sg_remove: %s\n", sdp->disk->disk_name));
1515
1516         /* Need a write lock to set sdp->detached. */
1517         write_lock_irqsave(&sg_index_lock, iflags);
1518         sdp->detached = 1;
1519         list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1520                 wake_up_interruptible(&sfp->read_wait);
1521                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1522         }
1523         write_unlock_irqrestore(&sg_index_lock, iflags);
1524
1525         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1526         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1527         cdev_del(sdp->cdev);
1528         sdp->cdev = NULL;
1529
1530         sg_put_dev(sdp);
1531 }
1532
1533 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1534 module_param_named(def_reserved_size, def_reserved_size, int,
1535                    S_IRUGO | S_IWUSR);
1536 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1537
1538 MODULE_AUTHOR("Douglas Gilbert");
1539 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1540 MODULE_LICENSE("GPL");
1541 MODULE_VERSION(SG_VERSION_STR);
1542 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1543
1544 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1545                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1546 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1547 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1548
1549 static int __init
1550 init_sg(void)
1551 {
1552         int rc;
1553
1554         if (scatter_elem_sz < PAGE_SIZE) {
1555                 scatter_elem_sz = PAGE_SIZE;
1556                 scatter_elem_sz_prev = scatter_elem_sz;
1557         }
1558         if (def_reserved_size >= 0)
1559                 sg_big_buff = def_reserved_size;
1560         else
1561                 def_reserved_size = sg_big_buff;
1562
1563         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), 
1564                                     SG_MAX_DEVS, "sg");
1565         if (rc)
1566                 return rc;
1567         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1568         if ( IS_ERR(sg_sysfs_class) ) {
1569                 rc = PTR_ERR(sg_sysfs_class);
1570                 goto err_out;
1571         }
1572         sg_sysfs_valid = 1;
1573         rc = scsi_register_interface(&sg_interface);
1574         if (0 == rc) {
1575 #ifdef CONFIG_SCSI_PROC_FS
1576                 sg_proc_init();
1577 #endif                          /* CONFIG_SCSI_PROC_FS */
1578                 return 0;
1579         }
1580         class_destroy(sg_sysfs_class);
1581 err_out:
1582         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1583         return rc;
1584 }
1585
1586 static void __exit
1587 exit_sg(void)
1588 {
1589 #ifdef CONFIG_SCSI_PROC_FS
1590         sg_proc_cleanup();
1591 #endif                          /* CONFIG_SCSI_PROC_FS */
1592         scsi_unregister_interface(&sg_interface);
1593         class_destroy(sg_sysfs_class);
1594         sg_sysfs_valid = 0;
1595         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1596                                  SG_MAX_DEVS);
1597         idr_destroy(&sg_index_idr);
1598 }
1599
1600 static int sg_start_req(Sg_request *srp, unsigned char *cmd)
1601 {
1602         int res;
1603         struct request *rq;
1604         Sg_fd *sfp = srp->parentfp;
1605         sg_io_hdr_t *hp = &srp->header;
1606         int dxfer_len = (int) hp->dxfer_len;
1607         int dxfer_dir = hp->dxfer_direction;
1608         unsigned int iov_count = hp->iovec_count;
1609         Sg_scatter_hold *req_schp = &srp->data;
1610         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1611         struct request_queue *q = sfp->parentdp->device->request_queue;
1612         struct rq_map_data *md, map_data;
1613         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1614
1615         SCSI_LOG_TIMEOUT(4, printk(KERN_INFO "sg_start_req: dxfer_len=%d\n",
1616                                    dxfer_len));
1617
1618         rq = blk_get_request(q, rw, GFP_ATOMIC);
1619         if (!rq)
1620                 return -ENOMEM;
1621
1622         memcpy(rq->cmd, cmd, hp->cmd_len);
1623
1624         rq->cmd_len = hp->cmd_len;
1625         rq->cmd_type = REQ_TYPE_BLOCK_PC;
1626
1627         srp->rq = rq;
1628         rq->end_io_data = srp;
1629         rq->sense = srp->sense_b;
1630         rq->retries = SG_DEFAULT_RETRIES;
1631
1632         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1633                 return 0;
1634
1635         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1636             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1637             !sfp->parentdp->device->host->unchecked_isa_dma &&
1638             blk_rq_aligned(q, hp->dxferp, dxfer_len))
1639                 md = NULL;
1640         else
1641                 md = &map_data;
1642
1643         if (md) {
1644                 if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen)
1645                         sg_link_reserve(sfp, srp, dxfer_len);
1646                 else {
1647                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1648                         if (res)
1649                                 return res;
1650                 }
1651
1652                 md->pages = req_schp->pages;
1653                 md->page_order = req_schp->page_order;
1654                 md->nr_entries = req_schp->k_use_sg;
1655                 md->offset = 0;
1656                 md->null_mapped = hp->dxferp ? 0 : 1;
1657                 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1658                         md->from_user = 1;
1659                 else
1660                         md->from_user = 0;
1661         }
1662
1663         if (iov_count) {
1664                 int len, size = sizeof(struct sg_iovec) * iov_count;
1665                 struct iovec *iov;
1666
1667                 iov = kmalloc(size, GFP_ATOMIC);
1668                 if (!iov)
1669                         return -ENOMEM;
1670
1671                 if (copy_from_user(iov, hp->dxferp, size)) {
1672                         kfree(iov);
1673                         return -EFAULT;
1674                 }
1675
1676                 len = iov_length(iov, iov_count);
1677                 if (hp->dxfer_len < len) {
1678                         iov_count = iov_shorten(iov, iov_count, hp->dxfer_len);
1679                         len = hp->dxfer_len;
1680                 }
1681
1682                 res = blk_rq_map_user_iov(q, rq, md, (struct sg_iovec *)iov,
1683                                           iov_count,
1684                                           len, GFP_ATOMIC);
1685                 kfree(iov);
1686         } else
1687                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1688                                       hp->dxfer_len, GFP_ATOMIC);
1689
1690         if (!res) {
1691                 srp->bio = rq->bio;
1692
1693                 if (!md) {
1694                         req_schp->dio_in_use = 1;
1695                         hp->info |= SG_INFO_DIRECT_IO;
1696                 }
1697         }
1698         return res;
1699 }
1700
1701 static int sg_finish_rem_req(Sg_request * srp)
1702 {
1703         int ret = 0;
1704
1705         Sg_fd *sfp = srp->parentfp;
1706         Sg_scatter_hold *req_schp = &srp->data;
1707
1708         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1709         if (srp->rq) {
1710                 if (srp->bio)
1711                         ret = blk_rq_unmap_user(srp->bio);
1712
1713                 blk_put_request(srp->rq);
1714         }
1715
1716         if (srp->res_used)
1717                 sg_unlink_reserve(sfp, srp);
1718         else
1719                 sg_remove_scat(req_schp);
1720
1721         sg_remove_request(sfp, srp);
1722
1723         return ret;
1724 }
1725
1726 static int
1727 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1728 {
1729         int sg_bufflen = tablesize * sizeof(struct page *);
1730         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1731
1732         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1733         if (!schp->pages)
1734                 return -ENOMEM;
1735         schp->sglist_len = sg_bufflen;
1736         return tablesize;       /* number of scat_gath elements allocated */
1737 }
1738
1739 static int
1740 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1741 {
1742         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1743         int sg_tablesize = sfp->parentdp->sg_tablesize;
1744         int blk_size = buff_size, order;
1745         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1746
1747         if (blk_size < 0)
1748                 return -EFAULT;
1749         if (0 == blk_size)
1750                 ++blk_size;     /* don't know why */
1751         /* round request up to next highest SG_SECTOR_SZ byte boundary */
1752         blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1753         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1754                                    buff_size, blk_size));
1755
1756         /* N.B. ret_sz carried into this block ... */
1757         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1758         if (mx_sc_elems < 0)
1759                 return mx_sc_elems;     /* most likely -ENOMEM */
1760
1761         num = scatter_elem_sz;
1762         if (unlikely(num != scatter_elem_sz_prev)) {
1763                 if (num < PAGE_SIZE) {
1764                         scatter_elem_sz = PAGE_SIZE;
1765                         scatter_elem_sz_prev = PAGE_SIZE;
1766                 } else
1767                         scatter_elem_sz_prev = num;
1768         }
1769
1770         if (sfp->low_dma)
1771                 gfp_mask |= GFP_DMA;
1772
1773         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1774                 gfp_mask |= __GFP_ZERO;
1775
1776         order = get_order(num);
1777 retry:
1778         ret_sz = 1 << (PAGE_SHIFT + order);
1779
1780         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1781              k++, rem_sz -= ret_sz) {
1782
1783                 num = (rem_sz > scatter_elem_sz_prev) ?
1784                         scatter_elem_sz_prev : rem_sz;
1785
1786                 schp->pages[k] = alloc_pages(gfp_mask, order);
1787                 if (!schp->pages[k])
1788                         goto out;
1789
1790                 if (num == scatter_elem_sz_prev) {
1791                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1792                                 scatter_elem_sz = ret_sz;
1793                                 scatter_elem_sz_prev = ret_sz;
1794                         }
1795                 }
1796
1797                 SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k=%d, num=%d, "
1798                                  "ret_sz=%d\n", k, num, ret_sz));
1799         }               /* end of for loop */
1800
1801         schp->page_order = order;
1802         schp->k_use_sg = k;
1803         SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, "
1804                          "rem_sz=%d\n", k, rem_sz));
1805
1806         schp->bufflen = blk_size;
1807         if (rem_sz > 0) /* must have failed */
1808                 return -ENOMEM;
1809         return 0;
1810 out:
1811         for (i = 0; i < k; i++)
1812                 __free_pages(schp->pages[i], order);
1813
1814         if (--order >= 0)
1815                 goto retry;
1816
1817         return -ENOMEM;
1818 }
1819
1820 static void
1821 sg_remove_scat(Sg_scatter_hold * schp)
1822 {
1823         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1824         if (schp->pages && schp->sglist_len > 0) {
1825                 if (!schp->dio_in_use) {
1826                         int k;
1827
1828                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1829                                 SCSI_LOG_TIMEOUT(5, printk(
1830                                     "sg_remove_scat: k=%d, pg=0x%p\n",
1831                                     k, schp->pages[k]));
1832                                 __free_pages(schp->pages[k], schp->page_order);
1833                         }
1834
1835                         kfree(schp->pages);
1836                 }
1837         }
1838         memset(schp, 0, sizeof (*schp));
1839 }
1840
1841 static int
1842 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1843 {
1844         Sg_scatter_hold *schp = &srp->data;
1845         int k, num;
1846
1847         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
1848                                    num_read_xfer));
1849         if ((!outp) || (num_read_xfer <= 0))
1850                 return 0;
1851
1852         num = 1 << (PAGE_SHIFT + schp->page_order);
1853         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1854                 if (num > num_read_xfer) {
1855                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1856                                            num_read_xfer))
1857                                 return -EFAULT;
1858                         break;
1859                 } else {
1860                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1861                                            num))
1862                                 return -EFAULT;
1863                         num_read_xfer -= num;
1864                         if (num_read_xfer <= 0)
1865                                 break;
1866                         outp += num;
1867                 }
1868         }
1869
1870         return 0;
1871 }
1872
1873 static void
1874 sg_build_reserve(Sg_fd * sfp, int req_size)
1875 {
1876         Sg_scatter_hold *schp = &sfp->reserve;
1877
1878         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
1879         do {
1880                 if (req_size < PAGE_SIZE)
1881                         req_size = PAGE_SIZE;
1882                 if (0 == sg_build_indirect(schp, sfp, req_size))
1883                         return;
1884                 else
1885                         sg_remove_scat(schp);
1886                 req_size >>= 1; /* divide by 2 */
1887         } while (req_size > (PAGE_SIZE / 2));
1888 }
1889
1890 static void
1891 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1892 {
1893         Sg_scatter_hold *req_schp = &srp->data;
1894         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1895         int k, num, rem;
1896
1897         srp->res_used = 1;
1898         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
1899         rem = size;
1900
1901         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1902         for (k = 0; k < rsv_schp->k_use_sg; k++) {
1903                 if (rem <= num) {
1904                         req_schp->k_use_sg = k + 1;
1905                         req_schp->sglist_len = rsv_schp->sglist_len;
1906                         req_schp->pages = rsv_schp->pages;
1907
1908                         req_schp->bufflen = size;
1909                         req_schp->page_order = rsv_schp->page_order;
1910                         break;
1911                 } else
1912                         rem -= num;
1913         }
1914
1915         if (k >= rsv_schp->k_use_sg)
1916                 SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
1917 }
1918
1919 static void
1920 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
1921 {
1922         Sg_scatter_hold *req_schp = &srp->data;
1923
1924         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
1925                                    (int) req_schp->k_use_sg));
1926         req_schp->k_use_sg = 0;
1927         req_schp->bufflen = 0;
1928         req_schp->pages = NULL;
1929         req_schp->page_order = 0;
1930         req_schp->sglist_len = 0;
1931         sfp->save_scat_len = 0;
1932         srp->res_used = 0;
1933 }
1934
1935 static Sg_request *
1936 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
1937 {
1938         Sg_request *resp;
1939         unsigned long iflags;
1940
1941         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1942         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
1943                 /* look for requests that are ready + not SG_IO owned */
1944                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
1945                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
1946                         resp->done = 2; /* guard against other readers */
1947                         break;
1948                 }
1949         }
1950         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1951         return resp;
1952 }
1953
1954 /* always adds to end of list */
1955 static Sg_request *
1956 sg_add_request(Sg_fd * sfp)
1957 {
1958         int k;
1959         unsigned long iflags;
1960         Sg_request *resp;
1961         Sg_request *rp = sfp->req_arr;
1962
1963         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1964         resp = sfp->headrp;
1965         if (!resp) {
1966                 memset(rp, 0, sizeof (Sg_request));
1967                 rp->parentfp = sfp;
1968                 resp = rp;
1969                 sfp->headrp = resp;
1970         } else {
1971                 if (0 == sfp->cmd_q)
1972                         resp = NULL;    /* command queuing disallowed */
1973                 else {
1974                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
1975                                 if (!rp->parentfp)
1976                                         break;
1977                         }
1978                         if (k < SG_MAX_QUEUE) {
1979                                 memset(rp, 0, sizeof (Sg_request));
1980                                 rp->parentfp = sfp;
1981                                 while (resp->nextrp)
1982                                         resp = resp->nextrp;
1983                                 resp->nextrp = rp;
1984                                 resp = rp;
1985                         } else
1986                                 resp = NULL;
1987                 }
1988         }
1989         if (resp) {
1990                 resp->nextrp = NULL;
1991                 resp->header.duration = jiffies_to_msecs(jiffies);
1992         }
1993         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1994         return resp;
1995 }
1996
1997 /* Return of 1 for found; 0 for not found */
1998 static int
1999 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2000 {
2001         Sg_request *prev_rp;
2002         Sg_request *rp;
2003         unsigned long iflags;
2004         int res = 0;
2005
2006         if ((!sfp) || (!srp) || (!sfp->headrp))
2007                 return res;
2008         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2009         prev_rp = sfp->headrp;
2010         if (srp == prev_rp) {
2011                 sfp->headrp = prev_rp->nextrp;
2012                 prev_rp->parentfp = NULL;
2013                 res = 1;
2014         } else {
2015                 while ((rp = prev_rp->nextrp)) {
2016                         if (srp == rp) {
2017                                 prev_rp->nextrp = rp->nextrp;
2018                                 rp->parentfp = NULL;
2019                                 res = 1;
2020                                 break;
2021                         }
2022                         prev_rp = rp;
2023                 }
2024         }
2025         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2026         return res;
2027 }
2028
2029 static Sg_fd *
2030 sg_add_sfp(Sg_device * sdp, int dev)
2031 {
2032         Sg_fd *sfp;
2033         unsigned long iflags;
2034         int bufflen;
2035
2036         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2037         if (!sfp)
2038                 return NULL;
2039
2040         init_waitqueue_head(&sfp->read_wait);
2041         rwlock_init(&sfp->rq_list_lock);
2042
2043         kref_init(&sfp->f_ref);
2044         sfp->timeout = SG_DEFAULT_TIMEOUT;
2045         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2046         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2047         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2048             sdp->device->host->unchecked_isa_dma : 1;
2049         sfp->cmd_q = SG_DEF_COMMAND_Q;
2050         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2051         sfp->parentdp = sdp;
2052         write_lock_irqsave(&sg_index_lock, iflags);
2053         list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2054         write_unlock_irqrestore(&sg_index_lock, iflags);
2055         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2056         if (unlikely(sg_big_buff != def_reserved_size))
2057                 sg_big_buff = def_reserved_size;
2058
2059         bufflen = min_t(int, sg_big_buff,
2060                         queue_max_sectors(sdp->device->request_queue) * 512);
2061         sg_build_reserve(sfp, bufflen);
2062         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2063                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2064
2065         kref_get(&sdp->d_ref);
2066         __module_get(THIS_MODULE);
2067         return sfp;
2068 }
2069
2070 static void sg_remove_sfp_usercontext(struct work_struct *work)
2071 {
2072         struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2073         struct sg_device *sdp = sfp->parentdp;
2074
2075         /* Cleanup any responses which were never read(). */
2076         while (sfp->headrp)
2077                 sg_finish_rem_req(sfp->headrp);
2078
2079         if (sfp->reserve.bufflen > 0) {
2080                 SCSI_LOG_TIMEOUT(6,
2081                         printk("sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2082                                 (int) sfp->reserve.bufflen,
2083                                 (int) sfp->reserve.k_use_sg));
2084                 sg_remove_scat(&sfp->reserve);
2085         }
2086
2087         SCSI_LOG_TIMEOUT(6,
2088                 printk("sg_remove_sfp: %s, sfp=0x%p\n",
2089                         sdp->disk->disk_name,
2090                         sfp));
2091         kfree(sfp);
2092
2093         scsi_device_put(sdp->device);
2094         sg_put_dev(sdp);
2095         module_put(THIS_MODULE);
2096 }
2097
2098 static void sg_remove_sfp(struct kref *kref)
2099 {
2100         struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2101         struct sg_device *sdp = sfp->parentdp;
2102         unsigned long iflags;
2103
2104         write_lock_irqsave(&sg_index_lock, iflags);
2105         list_del(&sfp->sfd_siblings);
2106         write_unlock_irqrestore(&sg_index_lock, iflags);
2107         wake_up_interruptible(&sdp->o_excl_wait);
2108
2109         INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2110         schedule_work(&sfp->ew.work);
2111 }
2112
2113 static int
2114 sg_res_in_use(Sg_fd * sfp)
2115 {
2116         const Sg_request *srp;
2117         unsigned long iflags;
2118
2119         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2120         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2121                 if (srp->res_used)
2122                         break;
2123         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2124         return srp ? 1 : 0;
2125 }
2126
2127 #ifdef CONFIG_SCSI_PROC_FS
2128 static int
2129 sg_idr_max_id(int id, void *p, void *data)
2130 {
2131         int *k = data;
2132
2133         if (*k < id)
2134                 *k = id;
2135
2136         return 0;
2137 }
2138
2139 static int
2140 sg_last_dev(void)
2141 {
2142         int k = -1;
2143         unsigned long iflags;
2144
2145         read_lock_irqsave(&sg_index_lock, iflags);
2146         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2147         read_unlock_irqrestore(&sg_index_lock, iflags);
2148         return k + 1;           /* origin 1 */
2149 }
2150 #endif
2151
2152 /* must be called with sg_index_lock held */
2153 static Sg_device *sg_lookup_dev(int dev)
2154 {
2155         return idr_find(&sg_index_idr, dev);
2156 }
2157
2158 static Sg_device *sg_get_dev(int dev)
2159 {
2160         struct sg_device *sdp;
2161         unsigned long flags;
2162
2163         read_lock_irqsave(&sg_index_lock, flags);
2164         sdp = sg_lookup_dev(dev);
2165         if (!sdp)
2166                 sdp = ERR_PTR(-ENXIO);
2167         else if (sdp->detached) {
2168                 /* If sdp->detached, then the refcount may already be 0, in
2169                  * which case it would be a bug to do kref_get().
2170                  */
2171                 sdp = ERR_PTR(-ENODEV);
2172         } else
2173                 kref_get(&sdp->d_ref);
2174         read_unlock_irqrestore(&sg_index_lock, flags);
2175
2176         return sdp;
2177 }
2178
2179 static void sg_put_dev(struct sg_device *sdp)
2180 {
2181         kref_put(&sdp->d_ref, sg_device_destroy);
2182 }
2183
2184 #ifdef CONFIG_SCSI_PROC_FS
2185
2186 static struct proc_dir_entry *sg_proc_sgp = NULL;
2187
2188 static char sg_proc_sg_dirname[] = "scsi/sg";
2189
2190 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2191
2192 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2193 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2194                                   size_t count, loff_t *off);
2195 static const struct file_operations adio_fops = {
2196         .owner = THIS_MODULE,
2197         .open = sg_proc_single_open_adio,
2198         .read = seq_read,
2199         .llseek = seq_lseek,
2200         .write = sg_proc_write_adio,
2201         .release = single_release,
2202 };
2203
2204 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2205 static ssize_t sg_proc_write_dressz(struct file *filp, 
2206                 const char __user *buffer, size_t count, loff_t *off);
2207 static const struct file_operations dressz_fops = {
2208         .owner = THIS_MODULE,
2209         .open = sg_proc_single_open_dressz,
2210         .read = seq_read,
2211         .llseek = seq_lseek,
2212         .write = sg_proc_write_dressz,
2213         .release = single_release,
2214 };
2215
2216 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2217 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2218 static const struct file_operations version_fops = {
2219         .owner = THIS_MODULE,
2220         .open = sg_proc_single_open_version,
2221         .read = seq_read,
2222         .llseek = seq_lseek,
2223         .release = single_release,
2224 };
2225
2226 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2227 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2228 static const struct file_operations devhdr_fops = {
2229         .owner = THIS_MODULE,
2230         .open = sg_proc_single_open_devhdr,
2231         .read = seq_read,
2232         .llseek = seq_lseek,
2233         .release = single_release,
2234 };
2235
2236 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2237 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2238 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2239 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2240 static void dev_seq_stop(struct seq_file *s, void *v);
2241 static const struct file_operations dev_fops = {
2242         .owner = THIS_MODULE,
2243         .open = sg_proc_open_dev,
2244         .read = seq_read,
2245         .llseek = seq_lseek,
2246         .release = seq_release,
2247 };
2248 static const struct seq_operations dev_seq_ops = {
2249         .start = dev_seq_start,
2250         .next  = dev_seq_next,
2251         .stop  = dev_seq_stop,
2252         .show  = sg_proc_seq_show_dev,
2253 };
2254
2255 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2256 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2257 static const struct file_operations devstrs_fops = {
2258         .owner = THIS_MODULE,
2259         .open = sg_proc_open_devstrs,
2260         .read = seq_read,
2261         .llseek = seq_lseek,
2262         .release = seq_release,
2263 };
2264 static const struct seq_operations devstrs_seq_ops = {
2265         .start = dev_seq_start,
2266         .next  = dev_seq_next,
2267         .stop  = dev_seq_stop,
2268         .show  = sg_proc_seq_show_devstrs,
2269 };
2270
2271 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2272 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2273 static const struct file_operations debug_fops = {
2274         .owner = THIS_MODULE,
2275         .open = sg_proc_open_debug,
2276         .read = seq_read,
2277         .llseek = seq_lseek,
2278         .release = seq_release,
2279 };
2280 static const struct seq_operations debug_seq_ops = {
2281         .start = dev_seq_start,
2282         .next  = dev_seq_next,
2283         .stop  = dev_seq_stop,
2284         .show  = sg_proc_seq_show_debug,
2285 };
2286
2287
2288 struct sg_proc_leaf {
2289         const char * name;
2290         const struct file_operations * fops;
2291 };
2292
2293 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2294         {"allow_dio", &adio_fops},
2295         {"debug", &debug_fops},
2296         {"def_reserved_size", &dressz_fops},
2297         {"device_hdr", &devhdr_fops},
2298         {"devices", &dev_fops},
2299         {"device_strs", &devstrs_fops},
2300         {"version", &version_fops}
2301 };
2302
2303 static int
2304 sg_proc_init(void)
2305 {
2306         int k, mask;
2307         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2308         struct sg_proc_leaf * leaf;
2309
2310         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2311         if (!sg_proc_sgp)
2312                 return 1;
2313         for (k = 0; k < num_leaves; ++k) {
2314                 leaf = &sg_proc_leaf_arr[k];
2315                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2316                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2317         }
2318         return 0;
2319 }
2320
2321 static void
2322 sg_proc_cleanup(void)
2323 {
2324         int k;
2325         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2326
2327         if (!sg_proc_sgp)
2328                 return;
2329         for (k = 0; k < num_leaves; ++k)
2330                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2331         remove_proc_entry(sg_proc_sg_dirname, NULL);
2332 }
2333
2334
2335 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2336 {
2337         seq_printf(s, "%d\n", *((int *)s->private));
2338         return 0;
2339 }
2340
2341 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2342 {
2343         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2344 }
2345
2346 static ssize_t 
2347 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2348                    size_t count, loff_t *off)
2349 {
2350         int num;
2351         char buff[11];
2352
2353         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2354                 return -EACCES;
2355         num = (count < 10) ? count : 10;
2356         if (copy_from_user(buff, buffer, num))
2357                 return -EFAULT;
2358         buff[num] = '\0';
2359         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2360         return count;
2361 }
2362
2363 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2364 {
2365         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2366 }
2367
2368 static ssize_t 
2369 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2370                      size_t count, loff_t *off)
2371 {
2372         int num;
2373         unsigned long k = ULONG_MAX;
2374         char buff[11];
2375
2376         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2377                 return -EACCES;
2378         num = (count < 10) ? count : 10;
2379         if (copy_from_user(buff, buffer, num))
2380                 return -EFAULT;
2381         buff[num] = '\0';
2382         k = simple_strtoul(buff, NULL, 10);
2383         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2384                 sg_big_buff = k;
2385                 return count;
2386         }
2387         return -ERANGE;
2388 }
2389
2390 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2391 {
2392         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2393                    sg_version_date);
2394         return 0;
2395 }
2396
2397 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2398 {
2399         return single_open(file, sg_proc_seq_show_version, NULL);
2400 }
2401
2402 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2403 {
2404         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2405                    "online\n");
2406         return 0;
2407 }
2408
2409 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2410 {
2411         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2412 }
2413
2414 struct sg_proc_deviter {
2415         loff_t  index;
2416         size_t  max;
2417 };
2418
2419 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2420 {
2421         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2422
2423         s->private = it;
2424         if (! it)
2425                 return NULL;
2426
2427         it->index = *pos;
2428         it->max = sg_last_dev();
2429         if (it->index >= it->max)
2430                 return NULL;
2431         return it;
2432 }
2433
2434 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2435 {
2436         struct sg_proc_deviter * it = s->private;
2437
2438         *pos = ++it->index;
2439         return (it->index < it->max) ? it : NULL;
2440 }
2441
2442 static void dev_seq_stop(struct seq_file *s, void *v)
2443 {
2444         kfree(s->private);
2445 }
2446
2447 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2448 {
2449         return seq_open(file, &dev_seq_ops);
2450 }
2451
2452 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2453 {
2454         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2455         Sg_device *sdp;
2456         struct scsi_device *scsidp;
2457         unsigned long iflags;
2458
2459         read_lock_irqsave(&sg_index_lock, iflags);
2460         sdp = it ? sg_lookup_dev(it->index) : NULL;
2461         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2462                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2463                               scsidp->host->host_no, scsidp->channel,
2464                               scsidp->id, scsidp->lun, (int) scsidp->type,
2465                               1,
2466                               (int) scsidp->queue_depth,
2467                               (int) scsidp->device_busy,
2468                               (int) scsi_device_online(scsidp));
2469         else
2470                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2471         read_unlock_irqrestore(&sg_index_lock, iflags);
2472         return 0;
2473 }
2474
2475 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2476 {
2477         return seq_open(file, &devstrs_seq_ops);
2478 }
2479
2480 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2481 {
2482         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2483         Sg_device *sdp;
2484         struct scsi_device *scsidp;
2485         unsigned long iflags;
2486
2487         read_lock_irqsave(&sg_index_lock, iflags);
2488         sdp = it ? sg_lookup_dev(it->index) : NULL;
2489         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2490                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2491                            scsidp->vendor, scsidp->model, scsidp->rev);
2492         else
2493                 seq_printf(s, "<no active device>\n");
2494         read_unlock_irqrestore(&sg_index_lock, iflags);
2495         return 0;
2496 }
2497
2498 /* must be called while holding sg_index_lock */
2499 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2500 {
2501         int k, m, new_interface, blen, usg;
2502         Sg_request *srp;
2503         Sg_fd *fp;
2504         const sg_io_hdr_t *hp;
2505         const char * cp;
2506         unsigned int ms;
2507
2508         k = 0;
2509         list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2510                 k++;
2511                 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2512                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2513                            "(res)sgat=%d low_dma=%d\n", k,
2514                            jiffies_to_msecs(fp->timeout),
2515                            fp->reserve.bufflen,
2516                            (int) fp->reserve.k_use_sg,
2517                            (int) fp->low_dma);
2518                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2519                            (int) fp->cmd_q, (int) fp->force_packid,
2520                            (int) fp->keep_orphan, (int) fp->closed);
2521                 for (m = 0, srp = fp->headrp;
2522                                 srp != NULL;
2523                                 ++m, srp = srp->nextrp) {
2524                         hp = &srp->header;
2525                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2526                         if (srp->res_used) {
2527                                 if (new_interface && 
2528                                     (SG_FLAG_MMAP_IO & hp->flags))
2529                                         cp = "     mmap>> ";
2530                                 else
2531                                         cp = "     rb>> ";
2532                         } else {
2533                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2534                                         cp = "     dio>> ";
2535                                 else
2536                                         cp = "     ";
2537                         }
2538                         seq_printf(s, cp);
2539                         blen = srp->data.bufflen;
2540                         usg = srp->data.k_use_sg;
2541                         seq_printf(s, srp->done ? 
2542                                    ((1 == srp->done) ?  "rcv:" : "fin:")
2543                                    : "act:");
2544                         seq_printf(s, " id=%d blen=%d",
2545                                    srp->header.pack_id, blen);
2546                         if (srp->done)
2547                                 seq_printf(s, " dur=%d", hp->duration);
2548                         else {
2549                                 ms = jiffies_to_msecs(jiffies);
2550                                 seq_printf(s, " t_o/elap=%d/%d",
2551                                         (new_interface ? hp->timeout :
2552                                                   jiffies_to_msecs(fp->timeout)),
2553                                         (ms > hp->duration ? ms - hp->duration : 0));
2554                         }
2555                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2556                                    (int) srp->data.cmd_opcode);
2557                 }
2558                 if (0 == m)
2559                         seq_printf(s, "     No requests active\n");
2560                 read_unlock(&fp->rq_list_lock);
2561         }
2562 }
2563
2564 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2565 {
2566         return seq_open(file, &debug_seq_ops);
2567 }
2568
2569 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2570 {
2571         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2572         Sg_device *sdp;
2573         unsigned long iflags;
2574
2575         if (it && (0 == it->index)) {
2576                 seq_printf(s, "max_active_device=%d(origin 1)\n",
2577                            (int)it->max);
2578                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2579         }
2580
2581         read_lock_irqsave(&sg_index_lock, iflags);
2582         sdp = it ? sg_lookup_dev(it->index) : NULL;
2583         if (sdp && !list_empty(&sdp->sfds)) {
2584                 struct scsi_device *scsidp = sdp->device;
2585
2586                 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2587                 if (sdp->detached)
2588                         seq_printf(s, "detached pending close ");
2589                 else
2590                         seq_printf
2591                             (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2592                              scsidp->host->host_no,
2593                              scsidp->channel, scsidp->id,
2594                              scsidp->lun,
2595                              scsidp->host->hostt->emulated);
2596                 seq_printf(s, " sg_tablesize=%d excl=%d\n",
2597                            sdp->sg_tablesize, sdp->exclude);
2598                 sg_proc_debug_helper(s, sdp);
2599         }
2600         read_unlock_irqrestore(&sg_index_lock, iflags);
2601         return 0;
2602 }
2603
2604 #endif                          /* CONFIG_SCSI_PROC_FS */
2605
2606 module_init(init_sg);
2607 module_exit(exit_sg);