81e3bc7b02a1bd29a5302a66aa49d5662a6fa5f3
[linux-2.6.git] / drivers / scsi / sg.c
1 /*
2  *  History:
3  *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
4  *           to allow user process control of SCSI devices.
5  *  Development Sponsored by Killy Corp. NY NY
6  *
7  * Original driver (sg.c):
8  *        Copyright (C) 1992 Lawrence Foard
9  * Version 2 and 3 extensions to driver:
10  *        Copyright (C) 1998 - 2005 Douglas Gilbert
11  *
12  *  Modified  19-JAN-1998  Richard Gooch <rgooch@atnf.csiro.au>  Devfs support
13  *
14  * This program is free software; you can redistribute it and/or modify
15  * it under the terms of the GNU General Public License as published by
16  * the Free Software Foundation; either version 2, or (at your option)
17  * any later version.
18  *
19  */
20
21 static int sg_version_num = 30534;      /* 2 digits for each component */
22 #define SG_VERSION_STR "3.5.34"
23
24 /*
25  *  D. P. Gilbert (dgilbert@interlog.com, dougg@triode.net.au), notes:
26  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
27  *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
28  *        (otherwise the macros compile to empty statements).
29  *
30  */
31 #include <linux/module.h>
32
33 #include <linux/fs.h>
34 #include <linux/kernel.h>
35 #include <linux/sched.h>
36 #include <linux/string.h>
37 #include <linux/mm.h>
38 #include <linux/errno.h>
39 #include <linux/mtio.h>
40 #include <linux/ioctl.h>
41 #include <linux/fcntl.h>
42 #include <linux/init.h>
43 #include <linux/poll.h>
44 #include <linux/smp_lock.h>
45 #include <linux/moduleparam.h>
46 #include <linux/cdev.h>
47 #include <linux/seq_file.h>
48 #include <linux/blkdev.h>
49 #include <linux/delay.h>
50 #include <linux/scatterlist.h>
51
52 #include "scsi.h"
53 #include <scsi/scsi_dbg.h>
54 #include <scsi/scsi_host.h>
55 #include <scsi/scsi_driver.h>
56 #include <scsi/scsi_ioctl.h>
57 #include <scsi/sg.h>
58
59 #include "scsi_logging.h"
60
61 #ifdef CONFIG_SCSI_PROC_FS
62 #include <linux/proc_fs.h>
63 static char *sg_version_date = "20061027";
64
65 static int sg_proc_init(void);
66 static void sg_proc_cleanup(void);
67 #endif
68
69 #define SG_ALLOW_DIO_DEF 0
70 #define SG_ALLOW_DIO_CODE /* compile out by commenting this define */
71
72 #define SG_MAX_DEVS 32768
73
74 /*
75  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
76  * Then when using 32 bit integers x * m may overflow during the calculation.
77  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
78  * calculates the same, but prevents the overflow when both m and d
79  * are "small" numbers (like HZ and USER_HZ).
80  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
81  * in 32 bits.
82  */
83 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
84
85 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
86
87 int sg_big_buff = SG_DEF_RESERVED_SIZE;
88 /* N.B. This variable is readable and writeable via
89    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
90    of this size (or less if there is not enough memory) will be reserved
91    for use by this file descriptor. [Deprecated usage: this variable is also
92    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
93    the kernel (i.e. it is not a module).] */
94 static int def_reserved_size = -1;      /* picks up init parameter */
95 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
96
97 static int scatter_elem_sz = SG_SCATTER_SZ;
98 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
99
100 #define SG_SECTOR_SZ 512
101 #define SG_SECTOR_MSK (SG_SECTOR_SZ - 1)
102
103 #define SG_DEV_ARR_LUMP 32      /* amount to over allocate sg_dev_arr by */
104
105 static int sg_add(struct class_device *, struct class_interface *);
106 static void sg_remove(struct class_device *, struct class_interface *);
107
108 static DEFINE_RWLOCK(sg_dev_arr_lock);  /* Also used to lock
109                                                            file descriptor list for device */
110
111 static struct class_interface sg_interface = {
112         .add            = sg_add,
113         .remove         = sg_remove,
114 };
115
116 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
117         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
118         unsigned short sglist_len; /* size of malloc'd scatter-gather list ++ */
119         unsigned bufflen;       /* Size of (aggregate) data buffer */
120         unsigned b_malloc_len;  /* actual len malloc'ed in buffer */
121         struct scatterlist *buffer;/* scatter list */
122         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
123         unsigned char cmd_opcode; /* first byte of command */
124 } Sg_scatter_hold;
125
126 struct sg_device;               /* forward declarations */
127 struct sg_fd;
128
129 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
130         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
131         struct sg_fd *parentfp; /* NULL -> not in use */
132         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
133         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
134         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
135         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
136         char orphan;            /* 1 -> drop on sight, 0 -> normal */
137         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
138         volatile char done;     /* 0->before bh, 1->before read, 2->read */
139 } Sg_request;
140
141 typedef struct sg_fd {          /* holds the state of a file descriptor */
142         struct sg_fd *nextfp;   /* NULL when last opened fd on this device */
143         struct sg_device *parentdp;     /* owning device */
144         wait_queue_head_t read_wait;    /* queue read until command done */
145         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
146         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
147         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
148         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
149         unsigned save_scat_len; /* original length of trunc. scat. element */
150         Sg_request *headrp;     /* head of request slist, NULL->empty */
151         struct fasync_struct *async_qp; /* used by asynchronous notification */
152         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
153         char low_dma;           /* as in parent but possibly overridden to 1 */
154         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
155         volatile char closed;   /* 1 -> fd closed but request(s) outstanding */
156         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
157         char next_cmd_len;      /* 0 -> automatic (def), >0 -> use on next write() */
158         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
159         char mmap_called;       /* 0 -> mmap() never called on this fd */
160 } Sg_fd;
161
162 typedef struct sg_device { /* holds the state of each scsi generic device */
163         struct scsi_device *device;
164         wait_queue_head_t o_excl_wait;  /* queue open() when O_EXCL in use */
165         int sg_tablesize;       /* adapter's max scatter-gather table size */
166         Sg_fd *headfp;          /* first open fd belonging to this device */
167         volatile char detached; /* 0->attached, 1->detached pending removal */
168         volatile char exclude;  /* opened for exclusive access */
169         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
170         struct gendisk *disk;
171         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
172 } Sg_device;
173
174 static int sg_fasync(int fd, struct file *filp, int mode);
175 /* tasklet or soft irq callback */
176 static void sg_cmd_done(void *data, char *sense, int result, int resid);
177 static int sg_start_req(Sg_request * srp);
178 static void sg_finish_rem_req(Sg_request * srp);
179 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
180 static int sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp,
181                          int tablesize);
182 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
183                            Sg_request * srp);
184 static ssize_t sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
185                             int blocking, int read_only, Sg_request ** o_srp);
186 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
187                            unsigned char *cmnd, int timeout, int blocking);
188 static int sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
189                       int wr_xf, int *countp, unsigned char __user **up);
190 static int sg_write_xfer(Sg_request * srp);
191 static int sg_read_xfer(Sg_request * srp);
192 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
193 static void sg_remove_scat(Sg_scatter_hold * schp);
194 static void sg_build_reserve(Sg_fd * sfp, int req_size);
195 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
196 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
197 static struct page *sg_page_malloc(int rqSz, int lowDma, int *retSzp);
198 static void sg_page_free(struct page *page, int size);
199 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
200 static int sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
201 static void __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
202 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
203 static Sg_request *sg_add_request(Sg_fd * sfp);
204 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
205 static int sg_res_in_use(Sg_fd * sfp);
206 static int sg_allow_access(unsigned char opcode, char dev_type);
207 static int sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len);
208 static Sg_device *sg_get_dev(int dev);
209 #ifdef CONFIG_SCSI_PROC_FS
210 static int sg_last_dev(void);
211 #endif
212
213 static Sg_device **sg_dev_arr = NULL;
214 static int sg_dev_max;
215 static int sg_nr_dev;
216
217 #define SZ_SG_HEADER sizeof(struct sg_header)
218 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
219 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
220 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
221
222 static int
223 sg_open(struct inode *inode, struct file *filp)
224 {
225         int dev = iminor(inode);
226         int flags = filp->f_flags;
227         struct request_queue *q;
228         Sg_device *sdp;
229         Sg_fd *sfp;
230         int res;
231         int retval;
232
233         nonseekable_open(inode, filp);
234         SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
235         sdp = sg_get_dev(dev);
236         if ((!sdp) || (!sdp->device))
237                 return -ENXIO;
238         if (sdp->detached)
239                 return -ENODEV;
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                 return retval;
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 (sdp->headfp && (flags & O_NONBLOCK)) {
260                         retval = -EBUSY;
261                         goto error_out;
262                 }
263                 res = 0;
264                 __wait_event_interruptible(sdp->o_excl_wait,
265                         ((sdp->headfp || 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 (!sdp->headfp) {     /* no existing opens on this device */
288                 sdp->sgdebug = 0;
289                 q = sdp->device->request_queue;
290                 sdp->sg_tablesize = min(q->max_hw_segments,
291                                         q->max_phys_segments);
292         }
293         if ((sfp = sg_add_sfp(sdp, dev)))
294                 filp->private_data = sfp;
295         else {
296                 if (flags & O_EXCL)
297                         sdp->exclude = 0;       /* undo if error */
298                 retval = -ENOMEM;
299                 goto error_out;
300         }
301         return 0;
302
303       error_out:
304         scsi_device_put(sdp->device);
305         return retval;
306 }
307
308 /* Following function was formerly called 'sg_close' */
309 static int
310 sg_release(struct inode *inode, struct file *filp)
311 {
312         Sg_device *sdp;
313         Sg_fd *sfp;
314
315         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
316                 return -ENXIO;
317         SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
318         sg_fasync(-1, filp, 0); /* remove filp from async notification list */
319         if (0 == sg_remove_sfp(sdp, sfp)) {     /* Returns 1 when sdp gone */
320                 if (!sdp->detached) {
321                         scsi_device_put(sdp->device);
322                 }
323                 sdp->exclude = 0;
324                 wake_up_interruptible(&sdp->o_excl_wait);
325         }
326         return 0;
327 }
328
329 static ssize_t
330 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
331 {
332         Sg_device *sdp;
333         Sg_fd *sfp;
334         Sg_request *srp;
335         int req_pack_id = -1;
336         sg_io_hdr_t *hp;
337         struct sg_header *old_hdr = NULL;
338         int retval = 0;
339
340         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
341                 return -ENXIO;
342         SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
343                                    sdp->disk->disk_name, (int) count));
344
345         if (!access_ok(VERIFY_WRITE, buf, count))
346                 return -EFAULT;
347         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
348                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
349                 if (!old_hdr)
350                         return -ENOMEM;
351                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
352                         retval = -EFAULT;
353                         goto free_old_hdr;
354                 }
355                 if (old_hdr->reply_len < 0) {
356                         if (count >= SZ_SG_IO_HDR) {
357                                 sg_io_hdr_t *new_hdr;
358                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
359                                 if (!new_hdr) {
360                                         retval = -ENOMEM;
361                                         goto free_old_hdr;
362                                 }
363                                 retval =__copy_from_user
364                                     (new_hdr, buf, SZ_SG_IO_HDR);
365                                 req_pack_id = new_hdr->pack_id;
366                                 kfree(new_hdr);
367                                 if (retval) {
368                                         retval = -EFAULT;
369                                         goto free_old_hdr;
370                                 }
371                         }
372                 } else
373                         req_pack_id = old_hdr->pack_id;
374         }
375         srp = sg_get_rq_mark(sfp, req_pack_id);
376         if (!srp) {             /* now wait on packet to arrive */
377                 if (sdp->detached) {
378                         retval = -ENODEV;
379                         goto free_old_hdr;
380                 }
381                 if (filp->f_flags & O_NONBLOCK) {
382                         retval = -EAGAIN;
383                         goto free_old_hdr;
384                 }
385                 while (1) {
386                         retval = 0; /* following macro beats race condition */
387                         __wait_event_interruptible(sfp->read_wait,
388                                 (sdp->detached ||
389                                 (srp = sg_get_rq_mark(sfp, req_pack_id))), 
390                                 retval);
391                         if (sdp->detached) {
392                                 retval = -ENODEV;
393                                 goto free_old_hdr;
394                         }
395                         if (0 == retval)
396                                 break;
397
398                         /* -ERESTARTSYS as signal hit process */
399                         goto free_old_hdr;
400                 }
401         }
402         if (srp->header.interface_id != '\0') {
403                 retval = sg_new_read(sfp, buf, count, srp);
404                 goto free_old_hdr;
405         }
406
407         hp = &srp->header;
408         if (old_hdr == NULL) {
409                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
410                 if (! old_hdr) {
411                         retval = -ENOMEM;
412                         goto free_old_hdr;
413                 }
414         }
415         memset(old_hdr, 0, SZ_SG_HEADER);
416         old_hdr->reply_len = (int) hp->timeout;
417         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
418         old_hdr->pack_id = hp->pack_id;
419         old_hdr->twelve_byte =
420             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
421         old_hdr->target_status = hp->masked_status;
422         old_hdr->host_status = hp->host_status;
423         old_hdr->driver_status = hp->driver_status;
424         if ((CHECK_CONDITION & hp->masked_status) ||
425             (DRIVER_SENSE & hp->driver_status))
426                 memcpy(old_hdr->sense_buffer, srp->sense_b,
427                        sizeof (old_hdr->sense_buffer));
428         switch (hp->host_status) {
429         /* This setup of 'result' is for backward compatibility and is best
430            ignored by the user who should use target, host + driver status */
431         case DID_OK:
432         case DID_PASSTHROUGH:
433         case DID_SOFT_ERROR:
434                 old_hdr->result = 0;
435                 break;
436         case DID_NO_CONNECT:
437         case DID_BUS_BUSY:
438         case DID_TIME_OUT:
439                 old_hdr->result = EBUSY;
440                 break;
441         case DID_BAD_TARGET:
442         case DID_ABORT:
443         case DID_PARITY:
444         case DID_RESET:
445         case DID_BAD_INTR:
446                 old_hdr->result = EIO;
447                 break;
448         case DID_ERROR:
449                 old_hdr->result = (srp->sense_b[0] == 0 && 
450                                   hp->masked_status == GOOD) ? 0 : EIO;
451                 break;
452         default:
453                 old_hdr->result = EIO;
454                 break;
455         }
456
457         /* Now copy the result back to the user buffer.  */
458         if (count >= SZ_SG_HEADER) {
459                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
460                         retval = -EFAULT;
461                         goto free_old_hdr;
462                 }
463                 buf += SZ_SG_HEADER;
464                 if (count > old_hdr->reply_len)
465                         count = old_hdr->reply_len;
466                 if (count > SZ_SG_HEADER) {
467                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
468                                 retval = -EFAULT;
469                                 goto free_old_hdr;
470                         }
471                 }
472         } else
473                 count = (old_hdr->result == 0) ? 0 : -EIO;
474         sg_finish_rem_req(srp);
475         retval = count;
476 free_old_hdr:
477         kfree(old_hdr);
478         return retval;
479 }
480
481 static ssize_t
482 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
483 {
484         sg_io_hdr_t *hp = &srp->header;
485         int err = 0;
486         int len;
487
488         if (count < SZ_SG_IO_HDR) {
489                 err = -EINVAL;
490                 goto err_out;
491         }
492         hp->sb_len_wr = 0;
493         if ((hp->mx_sb_len > 0) && hp->sbp) {
494                 if ((CHECK_CONDITION & hp->masked_status) ||
495                     (DRIVER_SENSE & hp->driver_status)) {
496                         int sb_len = SCSI_SENSE_BUFFERSIZE;
497                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
498                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
499                         len = (len > sb_len) ? sb_len : len;
500                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
501                                 err = -EFAULT;
502                                 goto err_out;
503                         }
504                         hp->sb_len_wr = len;
505                 }
506         }
507         if (hp->masked_status || hp->host_status || hp->driver_status)
508                 hp->info |= SG_INFO_CHECK;
509         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
510                 err = -EFAULT;
511                 goto err_out;
512         }
513         err = sg_read_xfer(srp);
514       err_out:
515         sg_finish_rem_req(srp);
516         return (0 == err) ? count : err;
517 }
518
519 static ssize_t
520 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
521 {
522         int mxsize, cmd_size, k;
523         int input_size, blocking;
524         unsigned char opcode;
525         Sg_device *sdp;
526         Sg_fd *sfp;
527         Sg_request *srp;
528         struct sg_header old_hdr;
529         sg_io_hdr_t *hp;
530         unsigned char cmnd[MAX_COMMAND_SIZE];
531
532         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
533                 return -ENXIO;
534         SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
535                                    sdp->disk->disk_name, (int) count));
536         if (sdp->detached)
537                 return -ENODEV;
538         if (!((filp->f_flags & O_NONBLOCK) ||
539               scsi_block_when_processing_errors(sdp->device)))
540                 return -ENXIO;
541
542         if (!access_ok(VERIFY_READ, buf, count))
543                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
544         if (count < SZ_SG_HEADER)
545                 return -EIO;
546         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
547                 return -EFAULT;
548         blocking = !(filp->f_flags & O_NONBLOCK);
549         if (old_hdr.reply_len < 0)
550                 return sg_new_write(sfp, buf, count, blocking, 0, NULL);
551         if (count < (SZ_SG_HEADER + 6))
552                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
553
554         if (!(srp = sg_add_request(sfp))) {
555                 SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
556                 return -EDOM;
557         }
558         buf += SZ_SG_HEADER;
559         __get_user(opcode, buf);
560         if (sfp->next_cmd_len > 0) {
561                 if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
562                         SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
563                         sfp->next_cmd_len = 0;
564                         sg_remove_request(sfp, srp);
565                         return -EIO;
566                 }
567                 cmd_size = sfp->next_cmd_len;
568                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
569         } else {
570                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
571                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
572                         cmd_size = 12;
573         }
574         SCSI_LOG_TIMEOUT(4, printk(
575                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
576 /* Determine buffer size.  */
577         input_size = count - cmd_size;
578         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
579         mxsize -= SZ_SG_HEADER;
580         input_size -= SZ_SG_HEADER;
581         if (input_size < 0) {
582                 sg_remove_request(sfp, srp);
583                 return -EIO;    /* User did not pass enough bytes for this command. */
584         }
585         hp = &srp->header;
586         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
587         hp->cmd_len = (unsigned char) cmd_size;
588         hp->iovec_count = 0;
589         hp->mx_sb_len = 0;
590         if (input_size > 0)
591                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
592                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
593         else
594                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
595         hp->dxfer_len = mxsize;
596         hp->dxferp = (char __user *)buf + cmd_size;
597         hp->sbp = NULL;
598         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
599         hp->flags = input_size; /* structure abuse ... */
600         hp->pack_id = old_hdr.pack_id;
601         hp->usr_ptr = NULL;
602         if (__copy_from_user(cmnd, buf, cmd_size))
603                 return -EFAULT;
604         /*
605          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
606          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
607          * is a non-zero input_size, so emit a warning.
608          */
609         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV)
610                 if (printk_ratelimit())
611                         printk(KERN_WARNING
612                                "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
613                                "guessing data in;\n" KERN_WARNING "   "
614                                "program %s not setting count and/or reply_len properly\n",
615                                old_hdr.reply_len - (int)SZ_SG_HEADER,
616                                input_size, (unsigned int) cmnd[0],
617                                current->comm);
618         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
619         return (k < 0) ? k : count;
620 }
621
622 static ssize_t
623 sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
624              int blocking, int read_only, Sg_request ** o_srp)
625 {
626         int k;
627         Sg_request *srp;
628         sg_io_hdr_t *hp;
629         unsigned char cmnd[MAX_COMMAND_SIZE];
630         int timeout;
631         unsigned long ul_timeout;
632
633         if (count < SZ_SG_IO_HDR)
634                 return -EINVAL;
635         if (!access_ok(VERIFY_READ, buf, count))
636                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
637
638         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
639         if (!(srp = sg_add_request(sfp))) {
640                 SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
641                 return -EDOM;
642         }
643         hp = &srp->header;
644         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
645                 sg_remove_request(sfp, srp);
646                 return -EFAULT;
647         }
648         if (hp->interface_id != 'S') {
649                 sg_remove_request(sfp, srp);
650                 return -ENOSYS;
651         }
652         if (hp->flags & SG_FLAG_MMAP_IO) {
653                 if (hp->dxfer_len > sfp->reserve.bufflen) {
654                         sg_remove_request(sfp, srp);
655                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
656                 }
657                 if (hp->flags & SG_FLAG_DIRECT_IO) {
658                         sg_remove_request(sfp, srp);
659                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
660                 }
661                 if (sg_res_in_use(sfp)) {
662                         sg_remove_request(sfp, srp);
663                         return -EBUSY;  /* reserve buffer already being used */
664                 }
665         }
666         ul_timeout = msecs_to_jiffies(srp->header.timeout);
667         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
668         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
669                 sg_remove_request(sfp, srp);
670                 return -EMSGSIZE;
671         }
672         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
673                 sg_remove_request(sfp, srp);
674                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
675         }
676         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
677                 sg_remove_request(sfp, srp);
678                 return -EFAULT;
679         }
680         if (read_only &&
681             (!sg_allow_access(cmnd[0], sfp->parentdp->device->type))) {
682                 sg_remove_request(sfp, srp);
683                 return -EPERM;
684         }
685         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
686         if (k < 0)
687                 return k;
688         if (o_srp)
689                 *o_srp = srp;
690         return count;
691 }
692
693 static int
694 sg_common_write(Sg_fd * sfp, Sg_request * srp,
695                 unsigned char *cmnd, int timeout, int blocking)
696 {
697         int k, data_dir;
698         Sg_device *sdp = sfp->parentdp;
699         sg_io_hdr_t *hp = &srp->header;
700
701         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
702         hp->status = 0;
703         hp->masked_status = 0;
704         hp->msg_status = 0;
705         hp->info = 0;
706         hp->host_status = 0;
707         hp->driver_status = 0;
708         hp->resid = 0;
709         SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
710                           (int) cmnd[0], (int) hp->cmd_len));
711
712         if ((k = sg_start_req(srp))) {
713                 SCSI_LOG_TIMEOUT(1, printk("sg_common_write: start_req err=%d\n", k));
714                 sg_finish_rem_req(srp);
715                 return k;       /* probably out of space --> ENOMEM */
716         }
717         if ((k = sg_write_xfer(srp))) {
718                 SCSI_LOG_TIMEOUT(1, printk("sg_common_write: write_xfer, bad address\n"));
719                 sg_finish_rem_req(srp);
720                 return k;
721         }
722         if (sdp->detached) {
723                 sg_finish_rem_req(srp);
724                 return -ENODEV;
725         }
726
727         switch (hp->dxfer_direction) {
728         case SG_DXFER_TO_FROM_DEV:
729         case SG_DXFER_FROM_DEV:
730                 data_dir = DMA_FROM_DEVICE;
731                 break;
732         case SG_DXFER_TO_DEV:
733                 data_dir = DMA_TO_DEVICE;
734                 break;
735         case SG_DXFER_UNKNOWN:
736                 data_dir = DMA_BIDIRECTIONAL;
737                 break;
738         default:
739                 data_dir = DMA_NONE;
740                 break;
741         }
742         hp->duration = jiffies_to_msecs(jiffies);
743 /* Now send everything of to mid-level. The next time we hear about this
744    packet is when sg_cmd_done() is called (i.e. a callback). */
745         if (scsi_execute_async(sdp->device, cmnd, hp->cmd_len, data_dir, srp->data.buffer,
746                                 hp->dxfer_len, srp->data.k_use_sg, timeout,
747                                 SG_DEFAULT_RETRIES, srp, sg_cmd_done,
748                                 GFP_ATOMIC)) {
749                 SCSI_LOG_TIMEOUT(1, printk("sg_common_write: scsi_execute_async failed\n"));
750                 /*
751                  * most likely out of mem, but could also be a bad map
752                  */
753                 sg_finish_rem_req(srp);
754                 return -ENOMEM;
755         } else
756                 return 0;
757 }
758
759 static int
760 sg_srp_done(Sg_request *srp, Sg_fd *sfp)
761 {
762         unsigned long iflags;
763         int done;
764
765         read_lock_irqsave(&sfp->rq_list_lock, iflags);
766         done = srp->done;
767         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
768         return done;
769 }
770
771 static int
772 sg_ioctl(struct inode *inode, struct file *filp,
773          unsigned int cmd_in, unsigned long arg)
774 {
775         void __user *p = (void __user *)arg;
776         int __user *ip = p;
777         int result, val, read_only;
778         Sg_device *sdp;
779         Sg_fd *sfp;
780         Sg_request *srp;
781         unsigned long iflags;
782
783         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
784                 return -ENXIO;
785         SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
786                                    sdp->disk->disk_name, (int) cmd_in));
787         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
788
789         switch (cmd_in) {
790         case SG_IO:
791                 {
792                         int blocking = 1;       /* ignore O_NONBLOCK flag */
793
794                         if (sdp->detached)
795                                 return -ENODEV;
796                         if (!scsi_block_when_processing_errors(sdp->device))
797                                 return -ENXIO;
798                         if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
799                                 return -EFAULT;
800                         result =
801                             sg_new_write(sfp, p, SZ_SG_IO_HDR,
802                                          blocking, read_only, &srp);
803                         if (result < 0)
804                                 return result;
805                         srp->sg_io_owned = 1;
806                         while (1) {
807                                 result = 0;     /* following macro to beat race condition */
808                                 __wait_event_interruptible(sfp->read_wait,
809                                         (sdp->detached || sfp->closed || sg_srp_done(srp, sfp)),
810                                                            result);
811                                 if (sdp->detached)
812                                         return -ENODEV;
813                                 if (sfp->closed)
814                                         return 0;       /* request packet dropped already */
815                                 if (0 == result)
816                                         break;
817                                 srp->orphan = 1;
818                                 return result;  /* -ERESTARTSYS because signal hit process */
819                         }
820                         write_lock_irqsave(&sfp->rq_list_lock, iflags);
821                         srp->done = 2;
822                         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
823                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
824                         return (result < 0) ? result : 0;
825                 }
826         case SG_SET_TIMEOUT:
827                 result = get_user(val, ip);
828                 if (result)
829                         return result;
830                 if (val < 0)
831                         return -EIO;
832                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
833                     val = MULDIV (INT_MAX, USER_HZ, HZ);
834                 sfp->timeout_user = val;
835                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
836
837                 return 0;
838         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
839                                 /* strange ..., for backward compatibility */
840                 return sfp->timeout_user;
841         case SG_SET_FORCE_LOW_DMA:
842                 result = get_user(val, ip);
843                 if (result)
844                         return result;
845                 if (val) {
846                         sfp->low_dma = 1;
847                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
848                                 val = (int) sfp->reserve.bufflen;
849                                 sg_remove_scat(&sfp->reserve);
850                                 sg_build_reserve(sfp, val);
851                         }
852                 } else {
853                         if (sdp->detached)
854                                 return -ENODEV;
855                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
856                 }
857                 return 0;
858         case SG_GET_LOW_DMA:
859                 return put_user((int) sfp->low_dma, ip);
860         case SG_GET_SCSI_ID:
861                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
862                         return -EFAULT;
863                 else {
864                         sg_scsi_id_t __user *sg_idp = p;
865
866                         if (sdp->detached)
867                                 return -ENODEV;
868                         __put_user((int) sdp->device->host->host_no,
869                                    &sg_idp->host_no);
870                         __put_user((int) sdp->device->channel,
871                                    &sg_idp->channel);
872                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
873                         __put_user((int) sdp->device->lun, &sg_idp->lun);
874                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
875                         __put_user((short) sdp->device->host->cmd_per_lun,
876                                    &sg_idp->h_cmd_per_lun);
877                         __put_user((short) sdp->device->queue_depth,
878                                    &sg_idp->d_queue_depth);
879                         __put_user(0, &sg_idp->unused[0]);
880                         __put_user(0, &sg_idp->unused[1]);
881                         return 0;
882                 }
883         case SG_SET_FORCE_PACK_ID:
884                 result = get_user(val, ip);
885                 if (result)
886                         return result;
887                 sfp->force_packid = val ? 1 : 0;
888                 return 0;
889         case SG_GET_PACK_ID:
890                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
891                         return -EFAULT;
892                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
893                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
894                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
895                                 read_unlock_irqrestore(&sfp->rq_list_lock,
896                                                        iflags);
897                                 __put_user(srp->header.pack_id, ip);
898                                 return 0;
899                         }
900                 }
901                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
902                 __put_user(-1, ip);
903                 return 0;
904         case SG_GET_NUM_WAITING:
905                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
906                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
907                         if ((1 == srp->done) && (!srp->sg_io_owned))
908                                 ++val;
909                 }
910                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
911                 return put_user(val, ip);
912         case SG_GET_SG_TABLESIZE:
913                 return put_user(sdp->sg_tablesize, ip);
914         case SG_SET_RESERVED_SIZE:
915                 result = get_user(val, ip);
916                 if (result)
917                         return result;
918                 if (val < 0)
919                         return -EINVAL;
920                 if (val != sfp->reserve.bufflen) {
921                         if (sg_res_in_use(sfp) || sfp->mmap_called)
922                                 return -EBUSY;
923                         sg_remove_scat(&sfp->reserve);
924                         sg_build_reserve(sfp, val);
925                 }
926                 return 0;
927         case SG_GET_RESERVED_SIZE:
928                 val = (int) sfp->reserve.bufflen;
929                 return put_user(val, ip);
930         case SG_SET_COMMAND_Q:
931                 result = get_user(val, ip);
932                 if (result)
933                         return result;
934                 sfp->cmd_q = val ? 1 : 0;
935                 return 0;
936         case SG_GET_COMMAND_Q:
937                 return put_user((int) sfp->cmd_q, ip);
938         case SG_SET_KEEP_ORPHAN:
939                 result = get_user(val, ip);
940                 if (result)
941                         return result;
942                 sfp->keep_orphan = val;
943                 return 0;
944         case SG_GET_KEEP_ORPHAN:
945                 return put_user((int) sfp->keep_orphan, ip);
946         case SG_NEXT_CMD_LEN:
947                 result = get_user(val, ip);
948                 if (result)
949                         return result;
950                 sfp->next_cmd_len = (val > 0) ? val : 0;
951                 return 0;
952         case SG_GET_VERSION_NUM:
953                 return put_user(sg_version_num, ip);
954         case SG_GET_ACCESS_COUNT:
955                 /* faked - we don't have a real access count anymore */
956                 val = (sdp->device ? 1 : 0);
957                 return put_user(val, ip);
958         case SG_GET_REQUEST_TABLE:
959                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
960                         return -EFAULT;
961                 else {
962                         sg_req_info_t *rinfo;
963                         unsigned int ms;
964
965                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
966                                                                 GFP_KERNEL);
967                         if (!rinfo)
968                                 return -ENOMEM;
969                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
970                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
971                              ++val, srp = srp ? srp->nextrp : srp) {
972                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
973                                 if (srp) {
974                                         rinfo[val].req_state = srp->done + 1;
975                                         rinfo[val].problem =
976                                             srp->header.masked_status & 
977                                             srp->header.host_status & 
978                                             srp->header.driver_status;
979                                         if (srp->done)
980                                                 rinfo[val].duration =
981                                                         srp->header.duration;
982                                         else {
983                                                 ms = jiffies_to_msecs(jiffies);
984                                                 rinfo[val].duration =
985                                                     (ms > srp->header.duration) ?
986                                                     (ms - srp->header.duration) : 0;
987                                         }
988                                         rinfo[val].orphan = srp->orphan;
989                                         rinfo[val].sg_io_owned =
990                                                         srp->sg_io_owned;
991                                         rinfo[val].pack_id =
992                                                         srp->header.pack_id;
993                                         rinfo[val].usr_ptr =
994                                                         srp->header.usr_ptr;
995                                 }
996                         }
997                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
998                         result = __copy_to_user(p, rinfo, 
999                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1000                         result = result ? -EFAULT : 0;
1001                         kfree(rinfo);
1002                         return result;
1003                 }
1004         case SG_EMULATED_HOST:
1005                 if (sdp->detached)
1006                         return -ENODEV;
1007                 return put_user(sdp->device->host->hostt->emulated, ip);
1008         case SG_SCSI_RESET:
1009                 if (sdp->detached)
1010                         return -ENODEV;
1011                 if (filp->f_flags & O_NONBLOCK) {
1012                         if (scsi_host_in_recovery(sdp->device->host))
1013                                 return -EBUSY;
1014                 } else if (!scsi_block_when_processing_errors(sdp->device))
1015                         return -EBUSY;
1016                 result = get_user(val, ip);
1017                 if (result)
1018                         return result;
1019                 if (SG_SCSI_RESET_NOTHING == val)
1020                         return 0;
1021                 switch (val) {
1022                 case SG_SCSI_RESET_DEVICE:
1023                         val = SCSI_TRY_RESET_DEVICE;
1024                         break;
1025                 case SG_SCSI_RESET_BUS:
1026                         val = SCSI_TRY_RESET_BUS;
1027                         break;
1028                 case SG_SCSI_RESET_HOST:
1029                         val = SCSI_TRY_RESET_HOST;
1030                         break;
1031                 default:
1032                         return -EINVAL;
1033                 }
1034                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1035                         return -EACCES;
1036                 return (scsi_reset_provider(sdp->device, val) ==
1037                         SUCCESS) ? 0 : -EIO;
1038         case SCSI_IOCTL_SEND_COMMAND:
1039                 if (sdp->detached)
1040                         return -ENODEV;
1041                 if (read_only) {
1042                         unsigned char opcode = WRITE_6;
1043                         Scsi_Ioctl_Command __user *siocp = p;
1044
1045                         if (copy_from_user(&opcode, siocp->data, 1))
1046                                 return -EFAULT;
1047                         if (!sg_allow_access(opcode, sdp->device->type))
1048                                 return -EPERM;
1049                 }
1050                 return sg_scsi_ioctl(filp, sdp->device->request_queue, NULL, p);
1051         case SG_SET_DEBUG:
1052                 result = get_user(val, ip);
1053                 if (result)
1054                         return result;
1055                 sdp->sgdebug = (char) val;
1056                 return 0;
1057         case SCSI_IOCTL_GET_IDLUN:
1058         case SCSI_IOCTL_GET_BUS_NUMBER:
1059         case SCSI_IOCTL_PROBE_HOST:
1060         case SG_GET_TRANSFORM:
1061                 if (sdp->detached)
1062                         return -ENODEV;
1063                 return scsi_ioctl(sdp->device, cmd_in, p);
1064         default:
1065                 if (read_only)
1066                         return -EPERM;  /* don't know so take safe approach */
1067                 return scsi_ioctl(sdp->device, cmd_in, p);
1068         }
1069 }
1070
1071 #ifdef CONFIG_COMPAT
1072 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1073 {
1074         Sg_device *sdp;
1075         Sg_fd *sfp;
1076         struct scsi_device *sdev;
1077
1078         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1079                 return -ENXIO;
1080
1081         sdev = sdp->device;
1082         if (sdev->host->hostt->compat_ioctl) { 
1083                 int ret;
1084
1085                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1086
1087                 return ret;
1088         }
1089         
1090         return -ENOIOCTLCMD;
1091 }
1092 #endif
1093
1094 static unsigned int
1095 sg_poll(struct file *filp, poll_table * wait)
1096 {
1097         unsigned int res = 0;
1098         Sg_device *sdp;
1099         Sg_fd *sfp;
1100         Sg_request *srp;
1101         int count = 0;
1102         unsigned long iflags;
1103
1104         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1105             || sfp->closed)
1106                 return POLLERR;
1107         poll_wait(filp, &sfp->read_wait, wait);
1108         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1109         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1110                 /* if any read waiting, flag it */
1111                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1112                         res = POLLIN | POLLRDNORM;
1113                 ++count;
1114         }
1115         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1116
1117         if (sdp->detached)
1118                 res |= POLLHUP;
1119         else if (!sfp->cmd_q) {
1120                 if (0 == count)
1121                         res |= POLLOUT | POLLWRNORM;
1122         } else if (count < SG_MAX_QUEUE)
1123                 res |= POLLOUT | POLLWRNORM;
1124         SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1125                                    sdp->disk->disk_name, (int) res));
1126         return res;
1127 }
1128
1129 static int
1130 sg_fasync(int fd, struct file *filp, int mode)
1131 {
1132         int retval;
1133         Sg_device *sdp;
1134         Sg_fd *sfp;
1135
1136         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1137                 return -ENXIO;
1138         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1139                                    sdp->disk->disk_name, mode));
1140
1141         retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
1142         return (retval < 0) ? retval : 0;
1143 }
1144
1145 static struct page *
1146 sg_vma_nopage(struct vm_area_struct *vma, unsigned long addr, int *type)
1147 {
1148         Sg_fd *sfp;
1149         struct page *page = NOPAGE_SIGBUS;
1150         unsigned long offset, len, sa;
1151         Sg_scatter_hold *rsv_schp;
1152         struct scatterlist *sg;
1153         int k;
1154
1155         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1156                 return page;
1157         rsv_schp = &sfp->reserve;
1158         offset = addr - vma->vm_start;
1159         if (offset >= rsv_schp->bufflen)
1160                 return page;
1161         SCSI_LOG_TIMEOUT(3, printk("sg_vma_nopage: offset=%lu, scatg=%d\n",
1162                                    offset, rsv_schp->k_use_sg));
1163         sg = rsv_schp->buffer;
1164         sa = vma->vm_start;
1165         for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1166              ++k, ++sg) {
1167                 len = vma->vm_end - sa;
1168                 len = (len < sg->length) ? len : sg->length;
1169                 if (offset < len) {
1170                         page = virt_to_page(page_address(sg->page) + offset);
1171                         get_page(page); /* increment page count */
1172                         break;
1173                 }
1174                 sa += len;
1175                 offset -= len;
1176         }
1177
1178         if (type)
1179                 *type = VM_FAULT_MINOR;
1180         return page;
1181 }
1182
1183 static struct vm_operations_struct sg_mmap_vm_ops = {
1184         .nopage = sg_vma_nopage,
1185 };
1186
1187 static int
1188 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1189 {
1190         Sg_fd *sfp;
1191         unsigned long req_sz, len, sa;
1192         Sg_scatter_hold *rsv_schp;
1193         int k;
1194         struct scatterlist *sg;
1195
1196         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1197                 return -ENXIO;
1198         req_sz = vma->vm_end - vma->vm_start;
1199         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1200                                    (void *) vma->vm_start, (int) req_sz));
1201         if (vma->vm_pgoff)
1202                 return -EINVAL; /* want no offset */
1203         rsv_schp = &sfp->reserve;
1204         if (req_sz > rsv_schp->bufflen)
1205                 return -ENOMEM; /* cannot map more than reserved buffer */
1206
1207         sa = vma->vm_start;
1208         sg = rsv_schp->buffer;
1209         for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1210              ++k, ++sg) {
1211                 len = vma->vm_end - sa;
1212                 len = (len < sg->length) ? len : sg->length;
1213                 sa += len;
1214         }
1215
1216         sfp->mmap_called = 1;
1217         vma->vm_flags |= VM_RESERVED;
1218         vma->vm_private_data = sfp;
1219         vma->vm_ops = &sg_mmap_vm_ops;
1220         return 0;
1221 }
1222
1223 /* This function is a "bottom half" handler that is called by the
1224  * mid level when a command is completed (or has failed). */
1225 static void
1226 sg_cmd_done(void *data, char *sense, int result, int resid)
1227 {
1228         Sg_request *srp = data;
1229         Sg_device *sdp = NULL;
1230         Sg_fd *sfp;
1231         unsigned long iflags;
1232         unsigned int ms;
1233
1234         if (NULL == srp) {
1235                 printk(KERN_ERR "sg_cmd_done: NULL request\n");
1236                 return;
1237         }
1238         sfp = srp->parentfp;
1239         if (sfp)
1240                 sdp = sfp->parentdp;
1241         if ((NULL == sdp) || sdp->detached) {
1242                 printk(KERN_INFO "sg_cmd_done: device detached\n");
1243                 return;
1244         }
1245
1246
1247         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1248                 sdp->disk->disk_name, srp->header.pack_id, result));
1249         srp->header.resid = resid;
1250         ms = jiffies_to_msecs(jiffies);
1251         srp->header.duration = (ms > srp->header.duration) ?
1252                                 (ms - srp->header.duration) : 0;
1253         if (0 != result) {
1254                 struct scsi_sense_hdr sshdr;
1255
1256                 memcpy(srp->sense_b, sense, sizeof (srp->sense_b));
1257                 srp->header.status = 0xff & result;
1258                 srp->header.masked_status = status_byte(result);
1259                 srp->header.msg_status = msg_byte(result);
1260                 srp->header.host_status = host_byte(result);
1261                 srp->header.driver_status = driver_byte(result);
1262                 if ((sdp->sgdebug > 0) &&
1263                     ((CHECK_CONDITION == srp->header.masked_status) ||
1264                      (COMMAND_TERMINATED == srp->header.masked_status)))
1265                         __scsi_print_sense("sg_cmd_done", sense,
1266                                            SCSI_SENSE_BUFFERSIZE);
1267
1268                 /* Following if statement is a patch supplied by Eric Youngdale */
1269                 if (driver_byte(result) != 0
1270                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1271                     && !scsi_sense_is_deferred(&sshdr)
1272                     && sshdr.sense_key == UNIT_ATTENTION
1273                     && sdp->device->removable) {
1274                         /* Detected possible disc change. Set the bit - this */
1275                         /* may be used if there are filesystems using this device */
1276                         sdp->device->changed = 1;
1277                 }
1278         }
1279         /* Rely on write phase to clean out srp status values, so no "else" */
1280
1281         if (sfp->closed) {      /* whoops this fd already released, cleanup */
1282                 SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
1283                 sg_finish_rem_req(srp);
1284                 srp = NULL;
1285                 if (NULL == sfp->headrp) {
1286                         SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, final cleanup\n"));
1287                         if (0 == sg_remove_sfp(sdp, sfp)) {     /* device still present */
1288                                 scsi_device_put(sdp->device);
1289                         }
1290                         sfp = NULL;
1291                 }
1292         } else if (srp && srp->orphan) {
1293                 if (sfp->keep_orphan)
1294                         srp->sg_io_owned = 0;
1295                 else {
1296                         sg_finish_rem_req(srp);
1297                         srp = NULL;
1298                 }
1299         }
1300         if (sfp && srp) {
1301                 /* Now wake up any sg_read() that is waiting for this packet. */
1302                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1303                 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1304                 srp->done = 1;
1305                 wake_up_interruptible(&sfp->read_wait);
1306                 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1307         }
1308 }
1309
1310 static struct file_operations sg_fops = {
1311         .owner = THIS_MODULE,
1312         .read = sg_read,
1313         .write = sg_write,
1314         .poll = sg_poll,
1315         .ioctl = sg_ioctl,
1316 #ifdef CONFIG_COMPAT
1317         .compat_ioctl = sg_compat_ioctl,
1318 #endif
1319         .open = sg_open,
1320         .mmap = sg_mmap,
1321         .release = sg_release,
1322         .fasync = sg_fasync,
1323 };
1324
1325 static struct class *sg_sysfs_class;
1326
1327 static int sg_sysfs_valid = 0;
1328
1329 static int sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1330 {
1331         struct request_queue *q = scsidp->request_queue;
1332         Sg_device *sdp;
1333         unsigned long iflags;
1334         void *old_sg_dev_arr = NULL;
1335         int k, error;
1336
1337         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1338         if (!sdp) {
1339                 printk(KERN_WARNING "kmalloc Sg_device failure\n");
1340                 return -ENOMEM;
1341         }
1342
1343         write_lock_irqsave(&sg_dev_arr_lock, iflags);
1344         if (unlikely(sg_nr_dev >= sg_dev_max)) {        /* try to resize */
1345                 Sg_device **tmp_da;
1346                 int tmp_dev_max = sg_nr_dev + SG_DEV_ARR_LUMP;
1347                 write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1348
1349                 tmp_da = kzalloc(tmp_dev_max * sizeof(Sg_device *), GFP_KERNEL);
1350                 if (unlikely(!tmp_da))
1351                         goto expand_failed;
1352
1353                 write_lock_irqsave(&sg_dev_arr_lock, iflags);
1354                 memcpy(tmp_da, sg_dev_arr, sg_dev_max * sizeof(Sg_device *));
1355                 old_sg_dev_arr = sg_dev_arr;
1356                 sg_dev_arr = tmp_da;
1357                 sg_dev_max = tmp_dev_max;
1358         }
1359
1360         for (k = 0; k < sg_dev_max; k++)
1361                 if (!sg_dev_arr[k])
1362                         break;
1363         if (unlikely(k >= SG_MAX_DEVS))
1364                 goto overflow;
1365
1366         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1367         sprintf(disk->disk_name, "sg%d", k);
1368         disk->first_minor = k;
1369         sdp->disk = disk;
1370         sdp->device = scsidp;
1371         init_waitqueue_head(&sdp->o_excl_wait);
1372         sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments);
1373
1374         sg_nr_dev++;
1375         sg_dev_arr[k] = sdp;
1376         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1377         error = k;
1378
1379  out:
1380         if (error < 0)
1381                 kfree(sdp);
1382         kfree(old_sg_dev_arr);
1383         return error;
1384
1385  expand_failed:
1386         printk(KERN_WARNING "sg_alloc: device array cannot be resized\n");
1387         error = -ENOMEM;
1388         goto out;
1389
1390  overflow:
1391         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1392         sdev_printk(KERN_WARNING, scsidp,
1393                     "Unable to attach sg device type=%d, minor "
1394                     "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1395         error = -ENODEV;
1396         goto out;
1397 }
1398
1399 static int
1400 sg_add(struct class_device *cl_dev, struct class_interface *cl_intf)
1401 {
1402         struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1403         struct gendisk *disk;
1404         Sg_device *sdp = NULL;
1405         struct cdev * cdev = NULL;
1406         int error, k;
1407         unsigned long iflags;
1408
1409         disk = alloc_disk(1);
1410         if (!disk) {
1411                 printk(KERN_WARNING "alloc_disk failed\n");
1412                 return -ENOMEM;
1413         }
1414         disk->major = SCSI_GENERIC_MAJOR;
1415
1416         error = -ENOMEM;
1417         cdev = cdev_alloc();
1418         if (!cdev) {
1419                 printk(KERN_WARNING "cdev_alloc failed\n");
1420                 goto out;
1421         }
1422         cdev->owner = THIS_MODULE;
1423         cdev->ops = &sg_fops;
1424
1425         error = sg_alloc(disk, scsidp);
1426         if (error < 0) {
1427                 printk(KERN_WARNING "sg_alloc failed\n");
1428                 goto out;
1429         }
1430         k = error;
1431         sdp = sg_dev_arr[k];
1432
1433         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, k), 1);
1434         if (error)
1435                 goto cdev_add_err;
1436
1437         sdp->cdev = cdev;
1438         if (sg_sysfs_valid) {
1439                 struct class_device * sg_class_member;
1440
1441                 sg_class_member = class_device_create(sg_sysfs_class, NULL,
1442                                 MKDEV(SCSI_GENERIC_MAJOR, k), 
1443                                 cl_dev->dev, "%s", 
1444                                 disk->disk_name);
1445                 if (IS_ERR(sg_class_member))
1446                         printk(KERN_WARNING "sg_add: "
1447                                 "class_device_create failed\n");
1448                 class_set_devdata(sg_class_member, sdp);
1449                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj, 
1450                                           &sg_class_member->kobj, "generic");
1451                 if (error)
1452                         printk(KERN_ERR "sg_add: unable to make symlink "
1453                                         "'generic' back to sg%d\n", k);
1454         } else
1455                 printk(KERN_WARNING "sg_add: sg_sys INvalid\n");
1456
1457         sdev_printk(KERN_NOTICE, scsidp,
1458                     "Attached scsi generic sg%d type %d\n", k,scsidp->type);
1459
1460         return 0;
1461
1462 cdev_add_err:
1463         write_lock_irqsave(&sg_dev_arr_lock, iflags);
1464         kfree(sg_dev_arr[k]);
1465         sg_dev_arr[k] = NULL;
1466         sg_nr_dev--;
1467         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1468
1469 out:
1470         put_disk(disk);
1471         if (cdev)
1472                 cdev_del(cdev);
1473         return error;
1474 }
1475
1476 static void
1477 sg_remove(struct class_device *cl_dev, struct class_interface *cl_intf)
1478 {
1479         struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1480         Sg_device *sdp = NULL;
1481         unsigned long iflags;
1482         Sg_fd *sfp;
1483         Sg_fd *tsfp;
1484         Sg_request *srp;
1485         Sg_request *tsrp;
1486         int k, delay;
1487
1488         if (NULL == sg_dev_arr)
1489                 return;
1490         delay = 0;
1491         write_lock_irqsave(&sg_dev_arr_lock, iflags);
1492         for (k = 0; k < sg_dev_max; k++) {
1493                 sdp = sg_dev_arr[k];
1494                 if ((NULL == sdp) || (sdp->device != scsidp))
1495                         continue;       /* dirty but lowers nesting */
1496                 if (sdp->headfp) {
1497                         sdp->detached = 1;
1498                         for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1499                                 tsfp = sfp->nextfp;
1500                                 for (srp = sfp->headrp; srp; srp = tsrp) {
1501                                         tsrp = srp->nextrp;
1502                                         if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
1503                                                 sg_finish_rem_req(srp);
1504                                 }
1505                                 if (sfp->closed) {
1506                                         scsi_device_put(sdp->device);
1507                                         __sg_remove_sfp(sdp, sfp);
1508                                 } else {
1509                                         delay = 1;
1510                                         wake_up_interruptible(&sfp->read_wait);
1511                                         kill_fasync(&sfp->async_qp, SIGPOLL,
1512                                                     POLL_HUP);
1513                                 }
1514                         }
1515                         SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d, dirty\n", k));
1516                         if (NULL == sdp->headfp) {
1517                                 sg_dev_arr[k] = NULL;
1518                         }
1519                 } else {        /* nothing active, simple case */
1520                         SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d\n", k));
1521                         sg_dev_arr[k] = NULL;
1522                 }
1523                 sg_nr_dev--;
1524                 break;
1525         }
1526         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1527
1528         if (sdp) {
1529                 sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1530                 class_device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, k));
1531                 cdev_del(sdp->cdev);
1532                 sdp->cdev = NULL;
1533                 put_disk(sdp->disk);
1534                 sdp->disk = NULL;
1535                 if (NULL == sdp->headfp)
1536                         kfree((char *) sdp);
1537         }
1538
1539         if (delay)
1540                 msleep(10);     /* dirty detach so delay device destruction */
1541 }
1542
1543 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1544 module_param_named(def_reserved_size, def_reserved_size, int,
1545                    S_IRUGO | S_IWUSR);
1546 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1547
1548 MODULE_AUTHOR("Douglas Gilbert");
1549 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1550 MODULE_LICENSE("GPL");
1551 MODULE_VERSION(SG_VERSION_STR);
1552 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1553
1554 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1555                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1556 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1557 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1558
1559 static int __init
1560 init_sg(void)
1561 {
1562         int rc;
1563
1564         if (scatter_elem_sz < PAGE_SIZE) {
1565                 scatter_elem_sz = PAGE_SIZE;
1566                 scatter_elem_sz_prev = scatter_elem_sz;
1567         }
1568         if (def_reserved_size >= 0)
1569                 sg_big_buff = def_reserved_size;
1570         else
1571                 def_reserved_size = sg_big_buff;
1572
1573         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), 
1574                                     SG_MAX_DEVS, "sg");
1575         if (rc)
1576                 return rc;
1577         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1578         if ( IS_ERR(sg_sysfs_class) ) {
1579                 rc = PTR_ERR(sg_sysfs_class);
1580                 goto err_out;
1581         }
1582         sg_sysfs_valid = 1;
1583         rc = scsi_register_interface(&sg_interface);
1584         if (0 == rc) {
1585 #ifdef CONFIG_SCSI_PROC_FS
1586                 sg_proc_init();
1587 #endif                          /* CONFIG_SCSI_PROC_FS */
1588                 return 0;
1589         }
1590         class_destroy(sg_sysfs_class);
1591 err_out:
1592         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1593         return rc;
1594 }
1595
1596 static void __exit
1597 exit_sg(void)
1598 {
1599 #ifdef CONFIG_SCSI_PROC_FS
1600         sg_proc_cleanup();
1601 #endif                          /* CONFIG_SCSI_PROC_FS */
1602         scsi_unregister_interface(&sg_interface);
1603         class_destroy(sg_sysfs_class);
1604         sg_sysfs_valid = 0;
1605         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1606                                  SG_MAX_DEVS);
1607         kfree((char *)sg_dev_arr);
1608         sg_dev_arr = NULL;
1609         sg_dev_max = 0;
1610 }
1611
1612 static int
1613 sg_start_req(Sg_request * srp)
1614 {
1615         int res;
1616         Sg_fd *sfp = srp->parentfp;
1617         sg_io_hdr_t *hp = &srp->header;
1618         int dxfer_len = (int) hp->dxfer_len;
1619         int dxfer_dir = hp->dxfer_direction;
1620         Sg_scatter_hold *req_schp = &srp->data;
1621         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1622
1623         SCSI_LOG_TIMEOUT(4, printk("sg_start_req: dxfer_len=%d\n", dxfer_len));
1624         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1625                 return 0;
1626         if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) &&
1627             (dxfer_dir != SG_DXFER_UNKNOWN) && (0 == hp->iovec_count) &&
1628             (!sfp->parentdp->device->host->unchecked_isa_dma)) {
1629                 res = sg_build_direct(srp, sfp, dxfer_len);
1630                 if (res <= 0)   /* -ve -> error, 0 -> done, 1 -> try indirect */
1631                         return res;
1632         }
1633         if ((!sg_res_in_use(sfp)) && (dxfer_len <= rsv_schp->bufflen))
1634                 sg_link_reserve(sfp, srp, dxfer_len);
1635         else {
1636                 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1637                 if (res) {
1638                         sg_remove_scat(req_schp);
1639                         return res;
1640                 }
1641         }
1642         return 0;
1643 }
1644
1645 static void
1646 sg_finish_rem_req(Sg_request * srp)
1647 {
1648         Sg_fd *sfp = srp->parentfp;
1649         Sg_scatter_hold *req_schp = &srp->data;
1650
1651         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1652         if (srp->res_used)
1653                 sg_unlink_reserve(sfp, srp);
1654         else
1655                 sg_remove_scat(req_schp);
1656         sg_remove_request(sfp, srp);
1657 }
1658
1659 static int
1660 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1661 {
1662         int sg_bufflen = tablesize * sizeof(struct scatterlist);
1663         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1664
1665         /*
1666          * TODO: test without low_dma, we should not need it since
1667          * the block layer will bounce the buffer for us
1668          *
1669          * XXX(hch): we shouldn't need GFP_DMA for the actual S/G list.
1670          */
1671         if (sfp->low_dma)
1672                  gfp_flags |= GFP_DMA;
1673         schp->buffer = kzalloc(sg_bufflen, gfp_flags);
1674         if (!schp->buffer)
1675                 return -ENOMEM;
1676         schp->sglist_len = sg_bufflen;
1677         return tablesize;       /* number of scat_gath elements allocated */
1678 }
1679
1680 #ifdef SG_ALLOW_DIO_CODE
1681 /* vvvvvvvv  following code borrowed from st driver's direct IO vvvvvvvvv */
1682         /* TODO: hopefully we can use the generic block layer code */
1683
1684 /* Pin down user pages and put them into a scatter gather list. Returns <= 0 if
1685    - mapping of all pages not successful
1686    (i.e., either completely successful or fails)
1687 */
1688 static int 
1689 st_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages, 
1690                   unsigned long uaddr, size_t count, int rw)
1691 {
1692         unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
1693         unsigned long start = uaddr >> PAGE_SHIFT;
1694         const int nr_pages = end - start;
1695         int res, i, j;
1696         struct page **pages;
1697
1698         /* User attempted Overflow! */
1699         if ((uaddr + count) < uaddr)
1700                 return -EINVAL;
1701
1702         /* Too big */
1703         if (nr_pages > max_pages)
1704                 return -ENOMEM;
1705
1706         /* Hmm? */
1707         if (count == 0)
1708                 return 0;
1709
1710         if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_ATOMIC)) == NULL)
1711                 return -ENOMEM;
1712
1713         /* Try to fault in all of the necessary pages */
1714         down_read(&current->mm->mmap_sem);
1715         /* rw==READ means read from drive, write into memory area */
1716         res = get_user_pages(
1717                 current,
1718                 current->mm,
1719                 uaddr,
1720                 nr_pages,
1721                 rw == READ,
1722                 0, /* don't force */
1723                 pages,
1724                 NULL);
1725         up_read(&current->mm->mmap_sem);
1726
1727         /* Errors and no page mapped should return here */
1728         if (res < nr_pages)
1729                 goto out_unmap;
1730
1731         for (i=0; i < nr_pages; i++) {
1732                 /* FIXME: flush superflous for rw==READ,
1733                  * probably wrong function for rw==WRITE
1734                  */
1735                 flush_dcache_page(pages[i]);
1736                 /* ?? Is locking needed? I don't think so */
1737                 /* if (TestSetPageLocked(pages[i]))
1738                    goto out_unlock; */
1739         }
1740
1741         sgl[0].page = pages[0];
1742         sgl[0].offset = uaddr & ~PAGE_MASK;
1743         if (nr_pages > 1) {
1744                 sgl[0].length = PAGE_SIZE - sgl[0].offset;
1745                 count -= sgl[0].length;
1746                 for (i=1; i < nr_pages ; i++) {
1747                         sgl[i].page = pages[i]; 
1748                         sgl[i].length = count < PAGE_SIZE ? count : PAGE_SIZE;
1749                         count -= PAGE_SIZE;
1750                 }
1751         }
1752         else {
1753                 sgl[0].length = count;
1754         }
1755
1756         kfree(pages);
1757         return nr_pages;
1758
1759  out_unmap:
1760         if (res > 0) {
1761                 for (j=0; j < res; j++)
1762                         page_cache_release(pages[j]);
1763                 res = 0;
1764         }
1765         kfree(pages);
1766         return res;
1767 }
1768
1769
1770 /* And unmap them... */
1771 static int 
1772 st_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_pages,
1773                     int dirtied)
1774 {
1775         int i;
1776
1777         for (i=0; i < nr_pages; i++) {
1778                 struct page *page = sgl[i].page;
1779
1780                 if (dirtied)
1781                         SetPageDirty(page);
1782                 /* unlock_page(page); */
1783                 /* FIXME: cache flush missing for rw==READ
1784                  * FIXME: call the correct reference counting function
1785                  */
1786                 page_cache_release(page);
1787         }
1788
1789         return 0;
1790 }
1791
1792 /* ^^^^^^^^  above code borrowed from st driver's direct IO ^^^^^^^^^ */
1793 #endif
1794
1795
1796 /* Returns: -ve -> error, 0 -> done, 1 -> try indirect */
1797 static int
1798 sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len)
1799 {
1800 #ifdef SG_ALLOW_DIO_CODE
1801         sg_io_hdr_t *hp = &srp->header;
1802         Sg_scatter_hold *schp = &srp->data;
1803         int sg_tablesize = sfp->parentdp->sg_tablesize;
1804         int mx_sc_elems, res;
1805         struct scsi_device *sdev = sfp->parentdp->device;
1806
1807         if (((unsigned long)hp->dxferp &
1808                         queue_dma_alignment(sdev->request_queue)) != 0)
1809                 return 1;
1810
1811         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1812         if (mx_sc_elems <= 0) {
1813                 return 1;
1814         }
1815         res = st_map_user_pages(schp->buffer, mx_sc_elems,
1816                                 (unsigned long)hp->dxferp, dxfer_len, 
1817                                 (SG_DXFER_TO_DEV == hp->dxfer_direction) ? 1 : 0);
1818         if (res <= 0) {
1819                 sg_remove_scat(schp);
1820                 return 1;
1821         }
1822         schp->k_use_sg = res;
1823         schp->dio_in_use = 1;
1824         hp->info |= SG_INFO_DIRECT_IO;
1825         return 0;
1826 #else
1827         return 1;
1828 #endif
1829 }
1830
1831 static int
1832 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1833 {
1834         struct scatterlist *sg;
1835         int ret_sz = 0, k, rem_sz, num, mx_sc_elems;
1836         int sg_tablesize = sfp->parentdp->sg_tablesize;
1837         int blk_size = buff_size;
1838         struct page *p = NULL;
1839
1840         if ((blk_size < 0) || (!sfp))
1841                 return -EFAULT;
1842         if (0 == blk_size)
1843                 ++blk_size;     /* don't know why */
1844 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1845         blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
1846         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1847                                    buff_size, blk_size));
1848
1849         /* N.B. ret_sz carried into this block ... */
1850         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1851         if (mx_sc_elems < 0)
1852                 return mx_sc_elems;     /* most likely -ENOMEM */
1853
1854         num = scatter_elem_sz;
1855         if (unlikely(num != scatter_elem_sz_prev)) {
1856                 if (num < PAGE_SIZE) {
1857                         scatter_elem_sz = PAGE_SIZE;
1858                         scatter_elem_sz_prev = PAGE_SIZE;
1859                 } else
1860                         scatter_elem_sz_prev = num;
1861         }
1862         for (k = 0, sg = schp->buffer, rem_sz = blk_size;
1863              (rem_sz > 0) && (k < mx_sc_elems);
1864              ++k, rem_sz -= ret_sz, ++sg) {
1865                 
1866                 num = (rem_sz > scatter_elem_sz_prev) ?
1867                       scatter_elem_sz_prev : rem_sz;
1868                 p = sg_page_malloc(num, sfp->low_dma, &ret_sz);
1869                 if (!p)
1870                         return -ENOMEM;
1871
1872                 if (num == scatter_elem_sz_prev) {
1873                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1874                                 scatter_elem_sz = ret_sz;
1875                                 scatter_elem_sz_prev = ret_sz;
1876                         }
1877                 }
1878                 sg->page = p;
1879                 sg->length = (ret_sz > num) ? num : ret_sz;
1880
1881                 SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k=%d, num=%d, "
1882                                  "ret_sz=%d\n", k, num, ret_sz));
1883         }               /* end of for loop */
1884
1885         schp->k_use_sg = k;
1886         SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, "
1887                          "rem_sz=%d\n", k, rem_sz));
1888
1889         schp->bufflen = blk_size;
1890         if (rem_sz > 0) /* must have failed */
1891                 return -ENOMEM;
1892
1893         return 0;
1894 }
1895
1896 static int
1897 sg_write_xfer(Sg_request * srp)
1898 {
1899         sg_io_hdr_t *hp = &srp->header;
1900         Sg_scatter_hold *schp = &srp->data;
1901         struct scatterlist *sg = schp->buffer;
1902         int num_xfer = 0;
1903         int j, k, onum, usglen, ksglen, res;
1904         int iovec_count = (int) hp->iovec_count;
1905         int dxfer_dir = hp->dxfer_direction;
1906         unsigned char *p;
1907         unsigned char __user *up;
1908         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
1909
1910         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_TO_DEV == dxfer_dir) ||
1911             (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
1912                 num_xfer = (int) (new_interface ? hp->dxfer_len : hp->flags);
1913                 if (schp->bufflen < num_xfer)
1914                         num_xfer = schp->bufflen;
1915         }
1916         if ((num_xfer <= 0) || (schp->dio_in_use) ||
1917             (new_interface
1918              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
1919                 return 0;
1920
1921         SCSI_LOG_TIMEOUT(4, printk("sg_write_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
1922                           num_xfer, iovec_count, schp->k_use_sg));
1923         if (iovec_count) {
1924                 onum = iovec_count;
1925                 if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
1926                         return -EFAULT;
1927         } else
1928                 onum = 1;
1929
1930         ksglen = sg->length;
1931         p = page_address(sg->page);
1932         for (j = 0, k = 0; j < onum; ++j) {
1933                 res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
1934                 if (res)
1935                         return res;
1936
1937                 for (; p; ++sg, ksglen = sg->length,
1938                      p = page_address(sg->page)) {
1939                         if (usglen <= 0)
1940                                 break;
1941                         if (ksglen > usglen) {
1942                                 if (usglen >= num_xfer) {
1943                                         if (__copy_from_user(p, up, num_xfer))
1944                                                 return -EFAULT;
1945                                         return 0;
1946                                 }
1947                                 if (__copy_from_user(p, up, usglen))
1948                                         return -EFAULT;
1949                                 p += usglen;
1950                                 ksglen -= usglen;
1951                                 break;
1952                         } else {
1953                                 if (ksglen >= num_xfer) {
1954                                         if (__copy_from_user(p, up, num_xfer))
1955                                                 return -EFAULT;
1956                                         return 0;
1957                                 }
1958                                 if (__copy_from_user(p, up, ksglen))
1959                                         return -EFAULT;
1960                                 up += ksglen;
1961                                 usglen -= ksglen;
1962                         }
1963                         ++k;
1964                         if (k >= schp->k_use_sg)
1965                                 return 0;
1966                 }
1967         }
1968
1969         return 0;
1970 }
1971
1972 static int
1973 sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
1974            int wr_xf, int *countp, unsigned char __user **up)
1975 {
1976         int num_xfer = (int) hp->dxfer_len;
1977         unsigned char __user *p = hp->dxferp;
1978         int count;
1979
1980         if (0 == sg_num) {
1981                 if (wr_xf && ('\0' == hp->interface_id))
1982                         count = (int) hp->flags;        /* holds "old" input_size */
1983                 else
1984                         count = num_xfer;
1985         } else {
1986                 sg_iovec_t iovec;
1987                 if (__copy_from_user(&iovec, p + ind*SZ_SG_IOVEC, SZ_SG_IOVEC))
1988                         return -EFAULT;
1989                 p = iovec.iov_base;
1990                 count = (int) iovec.iov_len;
1991         }
1992         if (!access_ok(wr_xf ? VERIFY_READ : VERIFY_WRITE, p, count))
1993                 return -EFAULT;
1994         if (up)
1995                 *up = p;
1996         if (countp)
1997                 *countp = count;
1998         return 0;
1999 }
2000
2001 static void
2002 sg_remove_scat(Sg_scatter_hold * schp)
2003 {
2004         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
2005         if (schp->buffer && (schp->sglist_len > 0)) {
2006                 struct scatterlist *sg = schp->buffer;
2007
2008                 if (schp->dio_in_use) {
2009 #ifdef SG_ALLOW_DIO_CODE
2010                         st_unmap_user_pages(sg, schp->k_use_sg, TRUE);
2011 #endif
2012                 } else {
2013                         int k;
2014
2015                         for (k = 0; (k < schp->k_use_sg) && sg->page;
2016                              ++k, ++sg) {
2017                                 SCSI_LOG_TIMEOUT(5, printk(
2018                                     "sg_remove_scat: k=%d, pg=0x%p, len=%d\n",
2019                                     k, sg->page, sg->length));
2020                                 sg_page_free(sg->page, sg->length);
2021                         }
2022                 }
2023                 kfree(schp->buffer);
2024         }
2025         memset(schp, 0, sizeof (*schp));
2026 }
2027
2028 static int
2029 sg_read_xfer(Sg_request * srp)
2030 {
2031         sg_io_hdr_t *hp = &srp->header;
2032         Sg_scatter_hold *schp = &srp->data;
2033         struct scatterlist *sg = schp->buffer;
2034         int num_xfer = 0;
2035         int j, k, onum, usglen, ksglen, res;
2036         int iovec_count = (int) hp->iovec_count;
2037         int dxfer_dir = hp->dxfer_direction;
2038         unsigned char *p;
2039         unsigned char __user *up;
2040         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
2041
2042         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_FROM_DEV == dxfer_dir)
2043             || (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
2044                 num_xfer = hp->dxfer_len;
2045                 if (schp->bufflen < num_xfer)
2046                         num_xfer = schp->bufflen;
2047         }
2048         if ((num_xfer <= 0) || (schp->dio_in_use) ||
2049             (new_interface
2050              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
2051                 return 0;
2052
2053         SCSI_LOG_TIMEOUT(4, printk("sg_read_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
2054                           num_xfer, iovec_count, schp->k_use_sg));
2055         if (iovec_count) {
2056                 onum = iovec_count;
2057                 if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
2058                         return -EFAULT;
2059         } else
2060                 onum = 1;
2061
2062         p = page_address(sg->page);
2063         ksglen = sg->length;
2064         for (j = 0, k = 0; j < onum; ++j) {
2065                 res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
2066                 if (res)
2067                         return res;
2068
2069                 for (; p; ++sg, ksglen = sg->length,
2070                      p = page_address(sg->page)) {
2071                         if (usglen <= 0)
2072                                 break;
2073                         if (ksglen > usglen) {
2074                                 if (usglen >= num_xfer) {
2075                                         if (__copy_to_user(up, p, num_xfer))
2076                                                 return -EFAULT;
2077                                         return 0;
2078                                 }
2079                                 if (__copy_to_user(up, p, usglen))
2080                                         return -EFAULT;
2081                                 p += usglen;
2082                                 ksglen -= usglen;
2083                                 break;
2084                         } else {
2085                                 if (ksglen >= num_xfer) {
2086                                         if (__copy_to_user(up, p, num_xfer))
2087                                                 return -EFAULT;
2088                                         return 0;
2089                                 }
2090                                 if (__copy_to_user(up, p, ksglen))
2091                                         return -EFAULT;
2092                                 up += ksglen;
2093                                 usglen -= ksglen;
2094                         }
2095                         ++k;
2096                         if (k >= schp->k_use_sg)
2097                                 return 0;
2098                 }
2099         }
2100
2101         return 0;
2102 }
2103
2104 static int
2105 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
2106 {
2107         Sg_scatter_hold *schp = &srp->data;
2108         struct scatterlist *sg = schp->buffer;
2109         int k, num;
2110
2111         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
2112                                    num_read_xfer));
2113         if ((!outp) || (num_read_xfer <= 0))
2114                 return 0;
2115
2116         for (k = 0; (k < schp->k_use_sg) && sg->page; ++k, ++sg) {
2117                 num = sg->length;
2118                 if (num > num_read_xfer) {
2119                         if (__copy_to_user(outp, page_address(sg->page),
2120                                            num_read_xfer))
2121                                 return -EFAULT;
2122                         break;
2123                 } else {
2124                         if (__copy_to_user(outp, page_address(sg->page),
2125                                            num))
2126                                 return -EFAULT;
2127                         num_read_xfer -= num;
2128                         if (num_read_xfer <= 0)
2129                                 break;
2130                         outp += num;
2131                 }
2132         }
2133
2134         return 0;
2135 }
2136
2137 static void
2138 sg_build_reserve(Sg_fd * sfp, int req_size)
2139 {
2140         Sg_scatter_hold *schp = &sfp->reserve;
2141
2142         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
2143         do {
2144                 if (req_size < PAGE_SIZE)
2145                         req_size = PAGE_SIZE;
2146                 if (0 == sg_build_indirect(schp, sfp, req_size))
2147                         return;
2148                 else
2149                         sg_remove_scat(schp);
2150                 req_size >>= 1; /* divide by 2 */
2151         } while (req_size > (PAGE_SIZE / 2));
2152 }
2153
2154 static void
2155 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2156 {
2157         Sg_scatter_hold *req_schp = &srp->data;
2158         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2159         struct scatterlist *sg = rsv_schp->buffer;
2160         int k, num, rem;
2161
2162         srp->res_used = 1;
2163         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
2164         rem = size;
2165
2166         for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sg) {
2167                 num = sg->length;
2168                 if (rem <= num) {
2169                         sfp->save_scat_len = num;
2170                         sg->length = rem;
2171                         req_schp->k_use_sg = k + 1;
2172                         req_schp->sglist_len = rsv_schp->sglist_len;
2173                         req_schp->buffer = rsv_schp->buffer;
2174
2175                         req_schp->bufflen = size;
2176                         req_schp->b_malloc_len = rsv_schp->b_malloc_len;
2177                         break;
2178                 } else
2179                         rem -= num;
2180         }
2181
2182         if (k >= rsv_schp->k_use_sg)
2183                 SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
2184 }
2185
2186 static void
2187 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2188 {
2189         Sg_scatter_hold *req_schp = &srp->data;
2190         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2191
2192         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
2193                                    (int) req_schp->k_use_sg));
2194         if ((rsv_schp->k_use_sg > 0) && (req_schp->k_use_sg > 0)) {
2195                 struct scatterlist *sg = rsv_schp->buffer;
2196
2197                 if (sfp->save_scat_len > 0)
2198                         (sg + (req_schp->k_use_sg - 1))->length =
2199                             (unsigned) sfp->save_scat_len;
2200                 else
2201                         SCSI_LOG_TIMEOUT(1, printk ("sg_unlink_reserve: BAD save_scat_len\n"));
2202         }
2203         req_schp->k_use_sg = 0;
2204         req_schp->bufflen = 0;
2205         req_schp->buffer = NULL;
2206         req_schp->sglist_len = 0;
2207         sfp->save_scat_len = 0;
2208         srp->res_used = 0;
2209 }
2210
2211 static Sg_request *
2212 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2213 {
2214         Sg_request *resp;
2215         unsigned long iflags;
2216
2217         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2218         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2219                 /* look for requests that are ready + not SG_IO owned */
2220                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2221                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2222                         resp->done = 2; /* guard against other readers */
2223                         break;
2224                 }
2225         }
2226         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2227         return resp;
2228 }
2229
2230 #ifdef CONFIG_SCSI_PROC_FS
2231 static Sg_request *
2232 sg_get_nth_request(Sg_fd * sfp, int nth)
2233 {
2234         Sg_request *resp;
2235         unsigned long iflags;
2236         int k;
2237
2238         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2239         for (k = 0, resp = sfp->headrp; resp && (k < nth);
2240              ++k, resp = resp->nextrp) ;
2241         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2242         return resp;
2243 }
2244 #endif
2245
2246 /* always adds to end of list */
2247 static Sg_request *
2248 sg_add_request(Sg_fd * sfp)
2249 {
2250         int k;
2251         unsigned long iflags;
2252         Sg_request *resp;
2253         Sg_request *rp = sfp->req_arr;
2254
2255         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2256         resp = sfp->headrp;
2257         if (!resp) {
2258                 memset(rp, 0, sizeof (Sg_request));
2259                 rp->parentfp = sfp;
2260                 resp = rp;
2261                 sfp->headrp = resp;
2262         } else {
2263                 if (0 == sfp->cmd_q)
2264                         resp = NULL;    /* command queuing disallowed */
2265                 else {
2266                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2267                                 if (!rp->parentfp)
2268                                         break;
2269                         }
2270                         if (k < SG_MAX_QUEUE) {
2271                                 memset(rp, 0, sizeof (Sg_request));
2272                                 rp->parentfp = sfp;
2273                                 while (resp->nextrp)
2274                                         resp = resp->nextrp;
2275                                 resp->nextrp = rp;
2276                                 resp = rp;
2277                         } else
2278                                 resp = NULL;
2279                 }
2280         }
2281         if (resp) {
2282                 resp->nextrp = NULL;
2283                 resp->header.duration = jiffies_to_msecs(jiffies);
2284         }
2285         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2286         return resp;
2287 }
2288
2289 /* Return of 1 for found; 0 for not found */
2290 static int
2291 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2292 {
2293         Sg_request *prev_rp;
2294         Sg_request *rp;
2295         unsigned long iflags;
2296         int res = 0;
2297
2298         if ((!sfp) || (!srp) || (!sfp->headrp))
2299                 return res;
2300         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2301         prev_rp = sfp->headrp;
2302         if (srp == prev_rp) {
2303                 sfp->headrp = prev_rp->nextrp;
2304                 prev_rp->parentfp = NULL;
2305                 res = 1;
2306         } else {
2307                 while ((rp = prev_rp->nextrp)) {
2308                         if (srp == rp) {
2309                                 prev_rp->nextrp = rp->nextrp;
2310                                 rp->parentfp = NULL;
2311                                 res = 1;
2312                                 break;
2313                         }
2314                         prev_rp = rp;
2315                 }
2316         }
2317         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2318         return res;
2319 }
2320
2321 #ifdef CONFIG_SCSI_PROC_FS
2322 static Sg_fd *
2323 sg_get_nth_sfp(Sg_device * sdp, int nth)
2324 {
2325         Sg_fd *resp;
2326         unsigned long iflags;
2327         int k;
2328
2329         read_lock_irqsave(&sg_dev_arr_lock, iflags);
2330         for (k = 0, resp = sdp->headfp; resp && (k < nth);
2331              ++k, resp = resp->nextfp) ;
2332         read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2333         return resp;
2334 }
2335 #endif
2336
2337 static Sg_fd *
2338 sg_add_sfp(Sg_device * sdp, int dev)
2339 {
2340         Sg_fd *sfp;
2341         unsigned long iflags;
2342
2343         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2344         if (!sfp)
2345                 return NULL;
2346
2347         init_waitqueue_head(&sfp->read_wait);
2348         rwlock_init(&sfp->rq_list_lock);
2349
2350         sfp->timeout = SG_DEFAULT_TIMEOUT;
2351         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2352         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2353         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2354             sdp->device->host->unchecked_isa_dma : 1;
2355         sfp->cmd_q = SG_DEF_COMMAND_Q;
2356         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2357         sfp->parentdp = sdp;
2358         write_lock_irqsave(&sg_dev_arr_lock, iflags);
2359         if (!sdp->headfp)
2360                 sdp->headfp = sfp;
2361         else {                  /* add to tail of existing list */
2362                 Sg_fd *pfp = sdp->headfp;
2363                 while (pfp->nextfp)
2364                         pfp = pfp->nextfp;
2365                 pfp->nextfp = sfp;
2366         }
2367         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2368         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2369         if (unlikely(sg_big_buff != def_reserved_size))
2370                 sg_big_buff = def_reserved_size;
2371
2372         sg_build_reserve(sfp, sg_big_buff);
2373         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2374                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2375         return sfp;
2376 }
2377
2378 static void
2379 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2380 {
2381         Sg_fd *fp;
2382         Sg_fd *prev_fp;
2383
2384         prev_fp = sdp->headfp;
2385         if (sfp == prev_fp)
2386                 sdp->headfp = prev_fp->nextfp;
2387         else {
2388                 while ((fp = prev_fp->nextfp)) {
2389                         if (sfp == fp) {
2390                                 prev_fp->nextfp = fp->nextfp;
2391                                 break;
2392                         }
2393                         prev_fp = fp;
2394                 }
2395         }
2396         if (sfp->reserve.bufflen > 0) {
2397                 SCSI_LOG_TIMEOUT(6, 
2398                         printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2399                         (int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2400                 sg_remove_scat(&sfp->reserve);
2401         }
2402         sfp->parentdp = NULL;
2403         SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2404         kfree(sfp);
2405 }
2406
2407 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2408 static int
2409 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2410 {
2411         Sg_request *srp;
2412         Sg_request *tsrp;
2413         int dirty = 0;
2414         int res = 0;
2415
2416         for (srp = sfp->headrp; srp; srp = tsrp) {
2417                 tsrp = srp->nextrp;
2418                 if (sg_srp_done(srp, sfp))
2419                         sg_finish_rem_req(srp);
2420                 else
2421                         ++dirty;
2422         }
2423         if (0 == dirty) {
2424                 unsigned long iflags;
2425
2426                 write_lock_irqsave(&sg_dev_arr_lock, iflags);
2427                 __sg_remove_sfp(sdp, sfp);
2428                 if (sdp->detached && (NULL == sdp->headfp)) {
2429                         int k, maxd;
2430
2431                         maxd = sg_dev_max;
2432                         for (k = 0; k < maxd; ++k) {
2433                                 if (sdp == sg_dev_arr[k])
2434                                         break;
2435                         }
2436                         if (k < maxd)
2437                                 sg_dev_arr[k] = NULL;
2438                         kfree((char *) sdp);
2439                         res = 1;
2440                 }
2441                 write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2442         } else {
2443                 /* MOD_INC's to inhibit unloading sg and associated adapter driver */
2444                 /* only bump the access_count if we actually succeeded in
2445                  * throwing another counter on the host module */
2446                 scsi_device_get(sdp->device);   /* XXX: retval ignored? */      
2447                 sfp->closed = 1;        /* flag dirty state on this fd */
2448                 SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2449                                   dirty));
2450         }
2451         return res;
2452 }
2453
2454 static int
2455 sg_res_in_use(Sg_fd * sfp)
2456 {
2457         const Sg_request *srp;
2458         unsigned long iflags;
2459
2460         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2461         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2462                 if (srp->res_used)
2463                         break;
2464         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2465         return srp ? 1 : 0;
2466 }
2467
2468 /* The size fetched (value output via retSzp) set when non-NULL return */
2469 static struct page *
2470 sg_page_malloc(int rqSz, int lowDma, int *retSzp)
2471 {
2472         struct page *resp = NULL;
2473         gfp_t page_mask;
2474         int order, a_size;
2475         int resSz;
2476
2477         if ((rqSz <= 0) || (NULL == retSzp))
2478                 return resp;
2479
2480         if (lowDma)
2481                 page_mask = GFP_ATOMIC | GFP_DMA | __GFP_COMP | __GFP_NOWARN;
2482         else
2483                 page_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
2484
2485         for (order = 0, a_size = PAGE_SIZE; a_size < rqSz;
2486              order++, a_size <<= 1) ;
2487         resSz = a_size;         /* rounded up if necessary */
2488         resp = alloc_pages(page_mask, order);
2489         while ((!resp) && order) {
2490                 --order;
2491                 a_size >>= 1;   /* divide by 2, until PAGE_SIZE */
2492                 resp =  alloc_pages(page_mask, order);  /* try half */
2493                 resSz = a_size;
2494         }
2495         if (resp) {
2496                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2497                         memset(page_address(resp), 0, resSz);
2498                 *retSzp = resSz;
2499         }
2500         return resp;
2501 }
2502
2503 static void
2504 sg_page_free(struct page *page, int size)
2505 {
2506         int order, a_size;
2507
2508         if (!page)
2509                 return;
2510         for (order = 0, a_size = PAGE_SIZE; a_size < size;
2511              order++, a_size <<= 1) ;
2512         __free_pages(page, order);
2513 }
2514
2515 #ifndef MAINTENANCE_IN_CMD
2516 #define MAINTENANCE_IN_CMD 0xa3
2517 #endif
2518
2519 static unsigned char allow_ops[] = { TEST_UNIT_READY, REQUEST_SENSE,
2520         INQUIRY, READ_CAPACITY, READ_BUFFER, READ_6, READ_10, READ_12,
2521         READ_16, MODE_SENSE, MODE_SENSE_10, LOG_SENSE, REPORT_LUNS,
2522         SERVICE_ACTION_IN, RECEIVE_DIAGNOSTIC, READ_LONG, MAINTENANCE_IN_CMD
2523 };
2524
2525 static int
2526 sg_allow_access(unsigned char opcode, char dev_type)
2527 {
2528         int k;
2529
2530         if (TYPE_SCANNER == dev_type)   /* TYPE_ROM maybe burner */
2531                 return 1;
2532         for (k = 0; k < sizeof (allow_ops); ++k) {
2533                 if (opcode == allow_ops[k])
2534                         return 1;
2535         }
2536         return 0;
2537 }
2538
2539 #ifdef CONFIG_SCSI_PROC_FS
2540 static int
2541 sg_last_dev(void)
2542 {
2543         int k;
2544         unsigned long iflags;
2545
2546         read_lock_irqsave(&sg_dev_arr_lock, iflags);
2547         for (k = sg_dev_max - 1; k >= 0; --k)
2548                 if (sg_dev_arr[k] && sg_dev_arr[k]->device)
2549                         break;
2550         read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2551         return k + 1;           /* origin 1 */
2552 }
2553 #endif
2554
2555 static Sg_device *
2556 sg_get_dev(int dev)
2557 {
2558         Sg_device *sdp = NULL;
2559         unsigned long iflags;
2560
2561         if (sg_dev_arr && (dev >= 0)) {
2562                 read_lock_irqsave(&sg_dev_arr_lock, iflags);
2563                 if (dev < sg_dev_max)
2564                         sdp = sg_dev_arr[dev];
2565                 read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2566         }
2567         return sdp;
2568 }
2569
2570 #ifdef CONFIG_SCSI_PROC_FS
2571
2572 static struct proc_dir_entry *sg_proc_sgp = NULL;
2573
2574 static char sg_proc_sg_dirname[] = "scsi/sg";
2575
2576 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2577
2578 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2579 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2580                                   size_t count, loff_t *off);
2581 static struct file_operations adio_fops = {
2582         /* .owner, .read and .llseek added in sg_proc_init() */
2583         .open = sg_proc_single_open_adio,
2584         .write = sg_proc_write_adio,
2585         .release = single_release,
2586 };
2587
2588 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2589 static ssize_t sg_proc_write_dressz(struct file *filp, 
2590                 const char __user *buffer, size_t count, loff_t *off);
2591 static struct file_operations dressz_fops = {
2592         .open = sg_proc_single_open_dressz,
2593         .write = sg_proc_write_dressz,
2594         .release = single_release,
2595 };
2596
2597 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2598 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2599 static struct file_operations version_fops = {
2600         .open = sg_proc_single_open_version,
2601         .release = single_release,
2602 };
2603
2604 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2605 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2606 static struct file_operations devhdr_fops = {
2607         .open = sg_proc_single_open_devhdr,
2608         .release = single_release,
2609 };
2610
2611 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2612 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2613 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2614 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2615 static void dev_seq_stop(struct seq_file *s, void *v);
2616 static struct file_operations dev_fops = {
2617         .open = sg_proc_open_dev,
2618         .release = seq_release,
2619 };
2620 static struct seq_operations dev_seq_ops = {
2621         .start = dev_seq_start,
2622         .next  = dev_seq_next,
2623         .stop  = dev_seq_stop,
2624         .show  = sg_proc_seq_show_dev,
2625 };
2626
2627 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2628 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2629 static struct file_operations devstrs_fops = {
2630         .open = sg_proc_open_devstrs,
2631         .release = seq_release,
2632 };
2633 static struct seq_operations devstrs_seq_ops = {
2634         .start = dev_seq_start,
2635         .next  = dev_seq_next,
2636         .stop  = dev_seq_stop,
2637         .show  = sg_proc_seq_show_devstrs,
2638 };
2639
2640 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2641 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2642 static struct file_operations debug_fops = {
2643         .open = sg_proc_open_debug,
2644         .release = seq_release,
2645 };
2646 static struct seq_operations debug_seq_ops = {
2647         .start = dev_seq_start,
2648         .next  = dev_seq_next,
2649         .stop  = dev_seq_stop,
2650         .show  = sg_proc_seq_show_debug,
2651 };
2652
2653
2654 struct sg_proc_leaf {
2655         const char * name;
2656         struct file_operations * fops;
2657 };
2658
2659 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2660         {"allow_dio", &adio_fops},
2661         {"debug", &debug_fops},
2662         {"def_reserved_size", &dressz_fops},
2663         {"device_hdr", &devhdr_fops},
2664         {"devices", &dev_fops},
2665         {"device_strs", &devstrs_fops},
2666         {"version", &version_fops}
2667 };
2668
2669 static int
2670 sg_proc_init(void)
2671 {
2672         int k, mask;
2673         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2674         struct proc_dir_entry *pdep;
2675         struct sg_proc_leaf * leaf;
2676
2677         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2678         if (!sg_proc_sgp)
2679                 return 1;
2680         for (k = 0; k < num_leaves; ++k) {
2681                 leaf = &sg_proc_leaf_arr[k];
2682                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2683                 pdep = create_proc_entry(leaf->name, mask, sg_proc_sgp);
2684                 if (pdep) {
2685                         leaf->fops->owner = THIS_MODULE,
2686                         leaf->fops->read = seq_read,
2687                         leaf->fops->llseek = seq_lseek,
2688                         pdep->proc_fops = leaf->fops;
2689                 }
2690         }
2691         return 0;
2692 }
2693
2694 static void
2695 sg_proc_cleanup(void)
2696 {
2697         int k;
2698         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2699
2700         if (!sg_proc_sgp)
2701                 return;
2702         for (k = 0; k < num_leaves; ++k)
2703                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2704         remove_proc_entry(sg_proc_sg_dirname, NULL);
2705 }
2706
2707
2708 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2709 {
2710         seq_printf(s, "%d\n", *((int *)s->private));
2711         return 0;
2712 }
2713
2714 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2715 {
2716         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2717 }
2718
2719 static ssize_t 
2720 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2721                    size_t count, loff_t *off)
2722 {
2723         int num;
2724         char buff[11];
2725
2726         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2727                 return -EACCES;
2728         num = (count < 10) ? count : 10;
2729         if (copy_from_user(buff, buffer, num))
2730                 return -EFAULT;
2731         buff[num] = '\0';
2732         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2733         return count;
2734 }
2735
2736 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2737 {
2738         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2739 }
2740
2741 static ssize_t 
2742 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2743                      size_t count, loff_t *off)
2744 {
2745         int num;
2746         unsigned long k = ULONG_MAX;
2747         char buff[11];
2748
2749         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2750                 return -EACCES;
2751         num = (count < 10) ? count : 10;
2752         if (copy_from_user(buff, buffer, num))
2753                 return -EFAULT;
2754         buff[num] = '\0';
2755         k = simple_strtoul(buff, NULL, 10);
2756         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2757                 sg_big_buff = k;
2758                 return count;
2759         }
2760         return -ERANGE;
2761 }
2762
2763 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2764 {
2765         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2766                    sg_version_date);
2767         return 0;
2768 }
2769
2770 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2771 {
2772         return single_open(file, sg_proc_seq_show_version, NULL);
2773 }
2774
2775 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2776 {
2777         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2778                    "online\n");
2779         return 0;
2780 }
2781
2782 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2783 {
2784         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2785 }
2786
2787 struct sg_proc_deviter {
2788         loff_t  index;
2789         size_t  max;
2790 };
2791
2792 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2793 {
2794         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2795
2796         s->private = it;
2797         if (! it)
2798                 return NULL;
2799
2800         if (NULL == sg_dev_arr)
2801                 return NULL;
2802         it->index = *pos;
2803         it->max = sg_last_dev();
2804         if (it->index >= it->max)
2805                 return NULL;
2806         return it;
2807 }
2808
2809 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2810 {
2811         struct sg_proc_deviter * it = s->private;
2812
2813         *pos = ++it->index;
2814         return (it->index < it->max) ? it : NULL;
2815 }
2816
2817 static void dev_seq_stop(struct seq_file *s, void *v)
2818 {
2819         kfree(s->private);
2820 }
2821
2822 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2823 {
2824         return seq_open(file, &dev_seq_ops);
2825 }
2826
2827 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2828 {
2829         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2830         Sg_device *sdp;
2831         struct scsi_device *scsidp;
2832
2833         sdp = it ? sg_get_dev(it->index) : NULL;
2834         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2835                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2836                               scsidp->host->host_no, scsidp->channel,
2837                               scsidp->id, scsidp->lun, (int) scsidp->type,
2838                               1,
2839                               (int) scsidp->queue_depth,
2840                               (int) scsidp->device_busy,
2841                               (int) scsi_device_online(scsidp));
2842         else
2843                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2844         return 0;
2845 }
2846
2847 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2848 {
2849         return seq_open(file, &devstrs_seq_ops);
2850 }
2851
2852 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2853 {
2854         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2855         Sg_device *sdp;
2856         struct scsi_device *scsidp;
2857
2858         sdp = it ? sg_get_dev(it->index) : NULL;
2859         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2860                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2861                            scsidp->vendor, scsidp->model, scsidp->rev);
2862         else
2863                 seq_printf(s, "<no active device>\n");
2864         return 0;
2865 }
2866
2867 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2868 {
2869         int k, m, new_interface, blen, usg;
2870         Sg_request *srp;
2871         Sg_fd *fp;
2872         const sg_io_hdr_t *hp;
2873         const char * cp;
2874         unsigned int ms;
2875
2876         for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
2877                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2878                            "(res)sgat=%d low_dma=%d\n", k + 1,
2879                            jiffies_to_msecs(fp->timeout),
2880                            fp->reserve.bufflen,
2881                            (int) fp->reserve.k_use_sg,
2882                            (int) fp->low_dma);
2883                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2884                            (int) fp->cmd_q, (int) fp->force_packid,
2885                            (int) fp->keep_orphan, (int) fp->closed);
2886                 for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
2887                         hp = &srp->header;
2888                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2889                         if (srp->res_used) {
2890                                 if (new_interface && 
2891                                     (SG_FLAG_MMAP_IO & hp->flags))
2892                                         cp = "     mmap>> ";
2893                                 else
2894                                         cp = "     rb>> ";
2895                         } else {
2896                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2897                                         cp = "     dio>> ";
2898                                 else
2899                                         cp = "     ";
2900                         }
2901                         seq_printf(s, cp);
2902                         blen = srp->data.bufflen;
2903                         usg = srp->data.k_use_sg;
2904                         seq_printf(s, srp->done ? 
2905                                    ((1 == srp->done) ?  "rcv:" : "fin:")
2906                                    : "act:");
2907                         seq_printf(s, " id=%d blen=%d",
2908                                    srp->header.pack_id, blen);
2909                         if (srp->done)
2910                                 seq_printf(s, " dur=%d", hp->duration);
2911                         else {
2912                                 ms = jiffies_to_msecs(jiffies);
2913                                 seq_printf(s, " t_o/elap=%d/%d",
2914                                         (new_interface ? hp->timeout :
2915                                                   jiffies_to_msecs(fp->timeout)),
2916                                         (ms > hp->duration ? ms - hp->duration : 0));
2917                         }
2918                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2919                                    (int) srp->data.cmd_opcode);
2920                 }
2921                 if (0 == m)
2922                         seq_printf(s, "     No requests active\n");
2923         }
2924 }
2925
2926 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2927 {
2928         return seq_open(file, &debug_seq_ops);
2929 }
2930
2931 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2932 {
2933         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2934         Sg_device *sdp;
2935
2936         if (it && (0 == it->index)) {
2937                 seq_printf(s, "dev_max(currently)=%d max_active_device=%d "
2938                            "(origin 1)\n", sg_dev_max, (int)it->max);
2939                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2940         }
2941         sdp = it ? sg_get_dev(it->index) : NULL;
2942         if (sdp) {
2943                 struct scsi_device *scsidp = sdp->device;
2944
2945                 if (NULL == scsidp) {
2946                         seq_printf(s, "device %d detached ??\n", 
2947                                    (int)it->index);
2948                         return 0;
2949                 }
2950
2951                 if (sg_get_nth_sfp(sdp, 0)) {
2952                         seq_printf(s, " >>> device=%s ",
2953                                 sdp->disk->disk_name);
2954                         if (sdp->detached)
2955                                 seq_printf(s, "detached pending close ");
2956                         else
2957                                 seq_printf
2958                                     (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2959                                      scsidp->host->host_no,
2960                                      scsidp->channel, scsidp->id,
2961                                      scsidp->lun,
2962                                      scsidp->host->hostt->emulated);
2963                         seq_printf(s, " sg_tablesize=%d excl=%d\n",
2964                                    sdp->sg_tablesize, sdp->exclude);
2965                 }
2966                 sg_proc_debug_helper(s, sdp);
2967         }
2968         return 0;
2969 }
2970
2971 #endif                          /* CONFIG_SCSI_PROC_FS */
2972
2973 module_init(init_sg);
2974 module_exit(exit_sg);