[SCSI] sg: cap reserved_size values at max_sectors
[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                 val = min_t(int, val,
921                                 sdp->device->request_queue->max_sectors * 512);
922                 if (val != sfp->reserve.bufflen) {
923                         if (sg_res_in_use(sfp) || sfp->mmap_called)
924                                 return -EBUSY;
925                         sg_remove_scat(&sfp->reserve);
926                         sg_build_reserve(sfp, val);
927                 }
928                 return 0;
929         case SG_GET_RESERVED_SIZE:
930                 val = min_t(int, sfp->reserve.bufflen,
931                                 sdp->device->request_queue->max_sectors * 512);
932                 return put_user(val, ip);
933         case SG_SET_COMMAND_Q:
934                 result = get_user(val, ip);
935                 if (result)
936                         return result;
937                 sfp->cmd_q = val ? 1 : 0;
938                 return 0;
939         case SG_GET_COMMAND_Q:
940                 return put_user((int) sfp->cmd_q, ip);
941         case SG_SET_KEEP_ORPHAN:
942                 result = get_user(val, ip);
943                 if (result)
944                         return result;
945                 sfp->keep_orphan = val;
946                 return 0;
947         case SG_GET_KEEP_ORPHAN:
948                 return put_user((int) sfp->keep_orphan, ip);
949         case SG_NEXT_CMD_LEN:
950                 result = get_user(val, ip);
951                 if (result)
952                         return result;
953                 sfp->next_cmd_len = (val > 0) ? val : 0;
954                 return 0;
955         case SG_GET_VERSION_NUM:
956                 return put_user(sg_version_num, ip);
957         case SG_GET_ACCESS_COUNT:
958                 /* faked - we don't have a real access count anymore */
959                 val = (sdp->device ? 1 : 0);
960                 return put_user(val, ip);
961         case SG_GET_REQUEST_TABLE:
962                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
963                         return -EFAULT;
964                 else {
965                         sg_req_info_t *rinfo;
966                         unsigned int ms;
967
968                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
969                                                                 GFP_KERNEL);
970                         if (!rinfo)
971                                 return -ENOMEM;
972                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
973                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
974                              ++val, srp = srp ? srp->nextrp : srp) {
975                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
976                                 if (srp) {
977                                         rinfo[val].req_state = srp->done + 1;
978                                         rinfo[val].problem =
979                                             srp->header.masked_status & 
980                                             srp->header.host_status & 
981                                             srp->header.driver_status;
982                                         if (srp->done)
983                                                 rinfo[val].duration =
984                                                         srp->header.duration;
985                                         else {
986                                                 ms = jiffies_to_msecs(jiffies);
987                                                 rinfo[val].duration =
988                                                     (ms > srp->header.duration) ?
989                                                     (ms - srp->header.duration) : 0;
990                                         }
991                                         rinfo[val].orphan = srp->orphan;
992                                         rinfo[val].sg_io_owned =
993                                                         srp->sg_io_owned;
994                                         rinfo[val].pack_id =
995                                                         srp->header.pack_id;
996                                         rinfo[val].usr_ptr =
997                                                         srp->header.usr_ptr;
998                                 }
999                         }
1000                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1001                         result = __copy_to_user(p, rinfo, 
1002                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1003                         result = result ? -EFAULT : 0;
1004                         kfree(rinfo);
1005                         return result;
1006                 }
1007         case SG_EMULATED_HOST:
1008                 if (sdp->detached)
1009                         return -ENODEV;
1010                 return put_user(sdp->device->host->hostt->emulated, ip);
1011         case SG_SCSI_RESET:
1012                 if (sdp->detached)
1013                         return -ENODEV;
1014                 if (filp->f_flags & O_NONBLOCK) {
1015                         if (scsi_host_in_recovery(sdp->device->host))
1016                                 return -EBUSY;
1017                 } else if (!scsi_block_when_processing_errors(sdp->device))
1018                         return -EBUSY;
1019                 result = get_user(val, ip);
1020                 if (result)
1021                         return result;
1022                 if (SG_SCSI_RESET_NOTHING == val)
1023                         return 0;
1024                 switch (val) {
1025                 case SG_SCSI_RESET_DEVICE:
1026                         val = SCSI_TRY_RESET_DEVICE;
1027                         break;
1028                 case SG_SCSI_RESET_BUS:
1029                         val = SCSI_TRY_RESET_BUS;
1030                         break;
1031                 case SG_SCSI_RESET_HOST:
1032                         val = SCSI_TRY_RESET_HOST;
1033                         break;
1034                 default:
1035                         return -EINVAL;
1036                 }
1037                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1038                         return -EACCES;
1039                 return (scsi_reset_provider(sdp->device, val) ==
1040                         SUCCESS) ? 0 : -EIO;
1041         case SCSI_IOCTL_SEND_COMMAND:
1042                 if (sdp->detached)
1043                         return -ENODEV;
1044                 if (read_only) {
1045                         unsigned char opcode = WRITE_6;
1046                         Scsi_Ioctl_Command __user *siocp = p;
1047
1048                         if (copy_from_user(&opcode, siocp->data, 1))
1049                                 return -EFAULT;
1050                         if (!sg_allow_access(opcode, sdp->device->type))
1051                                 return -EPERM;
1052                 }
1053                 return sg_scsi_ioctl(filp, sdp->device->request_queue, NULL, p);
1054         case SG_SET_DEBUG:
1055                 result = get_user(val, ip);
1056                 if (result)
1057                         return result;
1058                 sdp->sgdebug = (char) val;
1059                 return 0;
1060         case SCSI_IOCTL_GET_IDLUN:
1061         case SCSI_IOCTL_GET_BUS_NUMBER:
1062         case SCSI_IOCTL_PROBE_HOST:
1063         case SG_GET_TRANSFORM:
1064                 if (sdp->detached)
1065                         return -ENODEV;
1066                 return scsi_ioctl(sdp->device, cmd_in, p);
1067         case BLKSECTGET:
1068                 return put_user(sdp->device->request_queue->max_sectors * 512,
1069                                 ip);
1070         default:
1071                 if (read_only)
1072                         return -EPERM;  /* don't know so take safe approach */
1073                 return scsi_ioctl(sdp->device, cmd_in, p);
1074         }
1075 }
1076
1077 #ifdef CONFIG_COMPAT
1078 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1079 {
1080         Sg_device *sdp;
1081         Sg_fd *sfp;
1082         struct scsi_device *sdev;
1083
1084         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1085                 return -ENXIO;
1086
1087         sdev = sdp->device;
1088         if (sdev->host->hostt->compat_ioctl) { 
1089                 int ret;
1090
1091                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1092
1093                 return ret;
1094         }
1095         
1096         return -ENOIOCTLCMD;
1097 }
1098 #endif
1099
1100 static unsigned int
1101 sg_poll(struct file *filp, poll_table * wait)
1102 {
1103         unsigned int res = 0;
1104         Sg_device *sdp;
1105         Sg_fd *sfp;
1106         Sg_request *srp;
1107         int count = 0;
1108         unsigned long iflags;
1109
1110         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1111             || sfp->closed)
1112                 return POLLERR;
1113         poll_wait(filp, &sfp->read_wait, wait);
1114         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1115         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1116                 /* if any read waiting, flag it */
1117                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1118                         res = POLLIN | POLLRDNORM;
1119                 ++count;
1120         }
1121         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1122
1123         if (sdp->detached)
1124                 res |= POLLHUP;
1125         else if (!sfp->cmd_q) {
1126                 if (0 == count)
1127                         res |= POLLOUT | POLLWRNORM;
1128         } else if (count < SG_MAX_QUEUE)
1129                 res |= POLLOUT | POLLWRNORM;
1130         SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1131                                    sdp->disk->disk_name, (int) res));
1132         return res;
1133 }
1134
1135 static int
1136 sg_fasync(int fd, struct file *filp, int mode)
1137 {
1138         int retval;
1139         Sg_device *sdp;
1140         Sg_fd *sfp;
1141
1142         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1143                 return -ENXIO;
1144         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1145                                    sdp->disk->disk_name, mode));
1146
1147         retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
1148         return (retval < 0) ? retval : 0;
1149 }
1150
1151 static struct page *
1152 sg_vma_nopage(struct vm_area_struct *vma, unsigned long addr, int *type)
1153 {
1154         Sg_fd *sfp;
1155         struct page *page = NOPAGE_SIGBUS;
1156         unsigned long offset, len, sa;
1157         Sg_scatter_hold *rsv_schp;
1158         struct scatterlist *sg;
1159         int k;
1160
1161         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1162                 return page;
1163         rsv_schp = &sfp->reserve;
1164         offset = addr - vma->vm_start;
1165         if (offset >= rsv_schp->bufflen)
1166                 return page;
1167         SCSI_LOG_TIMEOUT(3, printk("sg_vma_nopage: offset=%lu, scatg=%d\n",
1168                                    offset, rsv_schp->k_use_sg));
1169         sg = rsv_schp->buffer;
1170         sa = vma->vm_start;
1171         for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1172              ++k, ++sg) {
1173                 len = vma->vm_end - sa;
1174                 len = (len < sg->length) ? len : sg->length;
1175                 if (offset < len) {
1176                         page = virt_to_page(page_address(sg->page) + offset);
1177                         get_page(page); /* increment page count */
1178                         break;
1179                 }
1180                 sa += len;
1181                 offset -= len;
1182         }
1183
1184         if (type)
1185                 *type = VM_FAULT_MINOR;
1186         return page;
1187 }
1188
1189 static struct vm_operations_struct sg_mmap_vm_ops = {
1190         .nopage = sg_vma_nopage,
1191 };
1192
1193 static int
1194 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1195 {
1196         Sg_fd *sfp;
1197         unsigned long req_sz, len, sa;
1198         Sg_scatter_hold *rsv_schp;
1199         int k;
1200         struct scatterlist *sg;
1201
1202         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1203                 return -ENXIO;
1204         req_sz = vma->vm_end - vma->vm_start;
1205         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1206                                    (void *) vma->vm_start, (int) req_sz));
1207         if (vma->vm_pgoff)
1208                 return -EINVAL; /* want no offset */
1209         rsv_schp = &sfp->reserve;
1210         if (req_sz > rsv_schp->bufflen)
1211                 return -ENOMEM; /* cannot map more than reserved buffer */
1212
1213         sa = vma->vm_start;
1214         sg = rsv_schp->buffer;
1215         for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1216              ++k, ++sg) {
1217                 len = vma->vm_end - sa;
1218                 len = (len < sg->length) ? len : sg->length;
1219                 sa += len;
1220         }
1221
1222         sfp->mmap_called = 1;
1223         vma->vm_flags |= VM_RESERVED;
1224         vma->vm_private_data = sfp;
1225         vma->vm_ops = &sg_mmap_vm_ops;
1226         return 0;
1227 }
1228
1229 /* This function is a "bottom half" handler that is called by the
1230  * mid level when a command is completed (or has failed). */
1231 static void
1232 sg_cmd_done(void *data, char *sense, int result, int resid)
1233 {
1234         Sg_request *srp = data;
1235         Sg_device *sdp = NULL;
1236         Sg_fd *sfp;
1237         unsigned long iflags;
1238         unsigned int ms;
1239
1240         if (NULL == srp) {
1241                 printk(KERN_ERR "sg_cmd_done: NULL request\n");
1242                 return;
1243         }
1244         sfp = srp->parentfp;
1245         if (sfp)
1246                 sdp = sfp->parentdp;
1247         if ((NULL == sdp) || sdp->detached) {
1248                 printk(KERN_INFO "sg_cmd_done: device detached\n");
1249                 return;
1250         }
1251
1252
1253         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1254                 sdp->disk->disk_name, srp->header.pack_id, result));
1255         srp->header.resid = resid;
1256         ms = jiffies_to_msecs(jiffies);
1257         srp->header.duration = (ms > srp->header.duration) ?
1258                                 (ms - srp->header.duration) : 0;
1259         if (0 != result) {
1260                 struct scsi_sense_hdr sshdr;
1261
1262                 memcpy(srp->sense_b, sense, sizeof (srp->sense_b));
1263                 srp->header.status = 0xff & result;
1264                 srp->header.masked_status = status_byte(result);
1265                 srp->header.msg_status = msg_byte(result);
1266                 srp->header.host_status = host_byte(result);
1267                 srp->header.driver_status = driver_byte(result);
1268                 if ((sdp->sgdebug > 0) &&
1269                     ((CHECK_CONDITION == srp->header.masked_status) ||
1270                      (COMMAND_TERMINATED == srp->header.masked_status)))
1271                         __scsi_print_sense("sg_cmd_done", sense,
1272                                            SCSI_SENSE_BUFFERSIZE);
1273
1274                 /* Following if statement is a patch supplied by Eric Youngdale */
1275                 if (driver_byte(result) != 0
1276                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1277                     && !scsi_sense_is_deferred(&sshdr)
1278                     && sshdr.sense_key == UNIT_ATTENTION
1279                     && sdp->device->removable) {
1280                         /* Detected possible disc change. Set the bit - this */
1281                         /* may be used if there are filesystems using this device */
1282                         sdp->device->changed = 1;
1283                 }
1284         }
1285         /* Rely on write phase to clean out srp status values, so no "else" */
1286
1287         if (sfp->closed) {      /* whoops this fd already released, cleanup */
1288                 SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
1289                 sg_finish_rem_req(srp);
1290                 srp = NULL;
1291                 if (NULL == sfp->headrp) {
1292                         SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, final cleanup\n"));
1293                         if (0 == sg_remove_sfp(sdp, sfp)) {     /* device still present */
1294                                 scsi_device_put(sdp->device);
1295                         }
1296                         sfp = NULL;
1297                 }
1298         } else if (srp && srp->orphan) {
1299                 if (sfp->keep_orphan)
1300                         srp->sg_io_owned = 0;
1301                 else {
1302                         sg_finish_rem_req(srp);
1303                         srp = NULL;
1304                 }
1305         }
1306         if (sfp && srp) {
1307                 /* Now wake up any sg_read() that is waiting for this packet. */
1308                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1309                 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1310                 srp->done = 1;
1311                 wake_up_interruptible(&sfp->read_wait);
1312                 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1313         }
1314 }
1315
1316 static struct file_operations sg_fops = {
1317         .owner = THIS_MODULE,
1318         .read = sg_read,
1319         .write = sg_write,
1320         .poll = sg_poll,
1321         .ioctl = sg_ioctl,
1322 #ifdef CONFIG_COMPAT
1323         .compat_ioctl = sg_compat_ioctl,
1324 #endif
1325         .open = sg_open,
1326         .mmap = sg_mmap,
1327         .release = sg_release,
1328         .fasync = sg_fasync,
1329 };
1330
1331 static struct class *sg_sysfs_class;
1332
1333 static int sg_sysfs_valid = 0;
1334
1335 static int sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1336 {
1337         struct request_queue *q = scsidp->request_queue;
1338         Sg_device *sdp;
1339         unsigned long iflags;
1340         void *old_sg_dev_arr = NULL;
1341         int k, error;
1342
1343         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1344         if (!sdp) {
1345                 printk(KERN_WARNING "kmalloc Sg_device failure\n");
1346                 return -ENOMEM;
1347         }
1348
1349         write_lock_irqsave(&sg_dev_arr_lock, iflags);
1350         if (unlikely(sg_nr_dev >= sg_dev_max)) {        /* try to resize */
1351                 Sg_device **tmp_da;
1352                 int tmp_dev_max = sg_nr_dev + SG_DEV_ARR_LUMP;
1353                 write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1354
1355                 tmp_da = kzalloc(tmp_dev_max * sizeof(Sg_device *), GFP_KERNEL);
1356                 if (unlikely(!tmp_da))
1357                         goto expand_failed;
1358
1359                 write_lock_irqsave(&sg_dev_arr_lock, iflags);
1360                 memcpy(tmp_da, sg_dev_arr, sg_dev_max * sizeof(Sg_device *));
1361                 old_sg_dev_arr = sg_dev_arr;
1362                 sg_dev_arr = tmp_da;
1363                 sg_dev_max = tmp_dev_max;
1364         }
1365
1366         for (k = 0; k < sg_dev_max; k++)
1367                 if (!sg_dev_arr[k])
1368                         break;
1369         if (unlikely(k >= SG_MAX_DEVS))
1370                 goto overflow;
1371
1372         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1373         sprintf(disk->disk_name, "sg%d", k);
1374         disk->first_minor = k;
1375         sdp->disk = disk;
1376         sdp->device = scsidp;
1377         init_waitqueue_head(&sdp->o_excl_wait);
1378         sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments);
1379
1380         sg_nr_dev++;
1381         sg_dev_arr[k] = sdp;
1382         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1383         error = k;
1384
1385  out:
1386         if (error < 0)
1387                 kfree(sdp);
1388         kfree(old_sg_dev_arr);
1389         return error;
1390
1391  expand_failed:
1392         printk(KERN_WARNING "sg_alloc: device array cannot be resized\n");
1393         error = -ENOMEM;
1394         goto out;
1395
1396  overflow:
1397         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1398         sdev_printk(KERN_WARNING, scsidp,
1399                     "Unable to attach sg device type=%d, minor "
1400                     "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1401         error = -ENODEV;
1402         goto out;
1403 }
1404
1405 static int
1406 sg_add(struct class_device *cl_dev, struct class_interface *cl_intf)
1407 {
1408         struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1409         struct gendisk *disk;
1410         Sg_device *sdp = NULL;
1411         struct cdev * cdev = NULL;
1412         int error, k;
1413         unsigned long iflags;
1414
1415         disk = alloc_disk(1);
1416         if (!disk) {
1417                 printk(KERN_WARNING "alloc_disk failed\n");
1418                 return -ENOMEM;
1419         }
1420         disk->major = SCSI_GENERIC_MAJOR;
1421
1422         error = -ENOMEM;
1423         cdev = cdev_alloc();
1424         if (!cdev) {
1425                 printk(KERN_WARNING "cdev_alloc failed\n");
1426                 goto out;
1427         }
1428         cdev->owner = THIS_MODULE;
1429         cdev->ops = &sg_fops;
1430
1431         error = sg_alloc(disk, scsidp);
1432         if (error < 0) {
1433                 printk(KERN_WARNING "sg_alloc failed\n");
1434                 goto out;
1435         }
1436         k = error;
1437         sdp = sg_dev_arr[k];
1438
1439         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, k), 1);
1440         if (error)
1441                 goto cdev_add_err;
1442
1443         sdp->cdev = cdev;
1444         if (sg_sysfs_valid) {
1445                 struct class_device * sg_class_member;
1446
1447                 sg_class_member = class_device_create(sg_sysfs_class, NULL,
1448                                 MKDEV(SCSI_GENERIC_MAJOR, k), 
1449                                 cl_dev->dev, "%s", 
1450                                 disk->disk_name);
1451                 if (IS_ERR(sg_class_member))
1452                         printk(KERN_WARNING "sg_add: "
1453                                 "class_device_create failed\n");
1454                 class_set_devdata(sg_class_member, sdp);
1455                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj, 
1456                                           &sg_class_member->kobj, "generic");
1457                 if (error)
1458                         printk(KERN_ERR "sg_add: unable to make symlink "
1459                                         "'generic' back to sg%d\n", k);
1460         } else
1461                 printk(KERN_WARNING "sg_add: sg_sys INvalid\n");
1462
1463         sdev_printk(KERN_NOTICE, scsidp,
1464                     "Attached scsi generic sg%d type %d\n", k,scsidp->type);
1465
1466         return 0;
1467
1468 cdev_add_err:
1469         write_lock_irqsave(&sg_dev_arr_lock, iflags);
1470         kfree(sg_dev_arr[k]);
1471         sg_dev_arr[k] = NULL;
1472         sg_nr_dev--;
1473         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1474
1475 out:
1476         put_disk(disk);
1477         if (cdev)
1478                 cdev_del(cdev);
1479         return error;
1480 }
1481
1482 static void
1483 sg_remove(struct class_device *cl_dev, struct class_interface *cl_intf)
1484 {
1485         struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1486         Sg_device *sdp = NULL;
1487         unsigned long iflags;
1488         Sg_fd *sfp;
1489         Sg_fd *tsfp;
1490         Sg_request *srp;
1491         Sg_request *tsrp;
1492         int k, delay;
1493
1494         if (NULL == sg_dev_arr)
1495                 return;
1496         delay = 0;
1497         write_lock_irqsave(&sg_dev_arr_lock, iflags);
1498         for (k = 0; k < sg_dev_max; k++) {
1499                 sdp = sg_dev_arr[k];
1500                 if ((NULL == sdp) || (sdp->device != scsidp))
1501                         continue;       /* dirty but lowers nesting */
1502                 if (sdp->headfp) {
1503                         sdp->detached = 1;
1504                         for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1505                                 tsfp = sfp->nextfp;
1506                                 for (srp = sfp->headrp; srp; srp = tsrp) {
1507                                         tsrp = srp->nextrp;
1508                                         if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
1509                                                 sg_finish_rem_req(srp);
1510                                 }
1511                                 if (sfp->closed) {
1512                                         scsi_device_put(sdp->device);
1513                                         __sg_remove_sfp(sdp, sfp);
1514                                 } else {
1515                                         delay = 1;
1516                                         wake_up_interruptible(&sfp->read_wait);
1517                                         kill_fasync(&sfp->async_qp, SIGPOLL,
1518                                                     POLL_HUP);
1519                                 }
1520                         }
1521                         SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d, dirty\n", k));
1522                         if (NULL == sdp->headfp) {
1523                                 sg_dev_arr[k] = NULL;
1524                         }
1525                 } else {        /* nothing active, simple case */
1526                         SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d\n", k));
1527                         sg_dev_arr[k] = NULL;
1528                 }
1529                 sg_nr_dev--;
1530                 break;
1531         }
1532         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1533
1534         if (sdp) {
1535                 sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1536                 class_device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, k));
1537                 cdev_del(sdp->cdev);
1538                 sdp->cdev = NULL;
1539                 put_disk(sdp->disk);
1540                 sdp->disk = NULL;
1541                 if (NULL == sdp->headfp)
1542                         kfree((char *) sdp);
1543         }
1544
1545         if (delay)
1546                 msleep(10);     /* dirty detach so delay device destruction */
1547 }
1548
1549 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1550 module_param_named(def_reserved_size, def_reserved_size, int,
1551                    S_IRUGO | S_IWUSR);
1552 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1553
1554 MODULE_AUTHOR("Douglas Gilbert");
1555 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1556 MODULE_LICENSE("GPL");
1557 MODULE_VERSION(SG_VERSION_STR);
1558 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1559
1560 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1561                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1562 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1563 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1564
1565 static int __init
1566 init_sg(void)
1567 {
1568         int rc;
1569
1570         if (scatter_elem_sz < PAGE_SIZE) {
1571                 scatter_elem_sz = PAGE_SIZE;
1572                 scatter_elem_sz_prev = scatter_elem_sz;
1573         }
1574         if (def_reserved_size >= 0)
1575                 sg_big_buff = def_reserved_size;
1576         else
1577                 def_reserved_size = sg_big_buff;
1578
1579         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), 
1580                                     SG_MAX_DEVS, "sg");
1581         if (rc)
1582                 return rc;
1583         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1584         if ( IS_ERR(sg_sysfs_class) ) {
1585                 rc = PTR_ERR(sg_sysfs_class);
1586                 goto err_out;
1587         }
1588         sg_sysfs_valid = 1;
1589         rc = scsi_register_interface(&sg_interface);
1590         if (0 == rc) {
1591 #ifdef CONFIG_SCSI_PROC_FS
1592                 sg_proc_init();
1593 #endif                          /* CONFIG_SCSI_PROC_FS */
1594                 return 0;
1595         }
1596         class_destroy(sg_sysfs_class);
1597 err_out:
1598         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1599         return rc;
1600 }
1601
1602 static void __exit
1603 exit_sg(void)
1604 {
1605 #ifdef CONFIG_SCSI_PROC_FS
1606         sg_proc_cleanup();
1607 #endif                          /* CONFIG_SCSI_PROC_FS */
1608         scsi_unregister_interface(&sg_interface);
1609         class_destroy(sg_sysfs_class);
1610         sg_sysfs_valid = 0;
1611         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1612                                  SG_MAX_DEVS);
1613         kfree((char *)sg_dev_arr);
1614         sg_dev_arr = NULL;
1615         sg_dev_max = 0;
1616 }
1617
1618 static int
1619 sg_start_req(Sg_request * srp)
1620 {
1621         int res;
1622         Sg_fd *sfp = srp->parentfp;
1623         sg_io_hdr_t *hp = &srp->header;
1624         int dxfer_len = (int) hp->dxfer_len;
1625         int dxfer_dir = hp->dxfer_direction;
1626         Sg_scatter_hold *req_schp = &srp->data;
1627         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1628
1629         SCSI_LOG_TIMEOUT(4, printk("sg_start_req: dxfer_len=%d\n", dxfer_len));
1630         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1631                 return 0;
1632         if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) &&
1633             (dxfer_dir != SG_DXFER_UNKNOWN) && (0 == hp->iovec_count) &&
1634             (!sfp->parentdp->device->host->unchecked_isa_dma)) {
1635                 res = sg_build_direct(srp, sfp, dxfer_len);
1636                 if (res <= 0)   /* -ve -> error, 0 -> done, 1 -> try indirect */
1637                         return res;
1638         }
1639         if ((!sg_res_in_use(sfp)) && (dxfer_len <= rsv_schp->bufflen))
1640                 sg_link_reserve(sfp, srp, dxfer_len);
1641         else {
1642                 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1643                 if (res) {
1644                         sg_remove_scat(req_schp);
1645                         return res;
1646                 }
1647         }
1648         return 0;
1649 }
1650
1651 static void
1652 sg_finish_rem_req(Sg_request * srp)
1653 {
1654         Sg_fd *sfp = srp->parentfp;
1655         Sg_scatter_hold *req_schp = &srp->data;
1656
1657         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1658         if (srp->res_used)
1659                 sg_unlink_reserve(sfp, srp);
1660         else
1661                 sg_remove_scat(req_schp);
1662         sg_remove_request(sfp, srp);
1663 }
1664
1665 static int
1666 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1667 {
1668         int sg_bufflen = tablesize * sizeof(struct scatterlist);
1669         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1670
1671         /*
1672          * TODO: test without low_dma, we should not need it since
1673          * the block layer will bounce the buffer for us
1674          *
1675          * XXX(hch): we shouldn't need GFP_DMA for the actual S/G list.
1676          */
1677         if (sfp->low_dma)
1678                  gfp_flags |= GFP_DMA;
1679         schp->buffer = kzalloc(sg_bufflen, gfp_flags);
1680         if (!schp->buffer)
1681                 return -ENOMEM;
1682         schp->sglist_len = sg_bufflen;
1683         return tablesize;       /* number of scat_gath elements allocated */
1684 }
1685
1686 #ifdef SG_ALLOW_DIO_CODE
1687 /* vvvvvvvv  following code borrowed from st driver's direct IO vvvvvvvvv */
1688         /* TODO: hopefully we can use the generic block layer code */
1689
1690 /* Pin down user pages and put them into a scatter gather list. Returns <= 0 if
1691    - mapping of all pages not successful
1692    (i.e., either completely successful or fails)
1693 */
1694 static int 
1695 st_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages, 
1696                   unsigned long uaddr, size_t count, int rw)
1697 {
1698         unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
1699         unsigned long start = uaddr >> PAGE_SHIFT;
1700         const int nr_pages = end - start;
1701         int res, i, j;
1702         struct page **pages;
1703
1704         /* User attempted Overflow! */
1705         if ((uaddr + count) < uaddr)
1706                 return -EINVAL;
1707
1708         /* Too big */
1709         if (nr_pages > max_pages)
1710                 return -ENOMEM;
1711
1712         /* Hmm? */
1713         if (count == 0)
1714                 return 0;
1715
1716         if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_ATOMIC)) == NULL)
1717                 return -ENOMEM;
1718
1719         /* Try to fault in all of the necessary pages */
1720         down_read(&current->mm->mmap_sem);
1721         /* rw==READ means read from drive, write into memory area */
1722         res = get_user_pages(
1723                 current,
1724                 current->mm,
1725                 uaddr,
1726                 nr_pages,
1727                 rw == READ,
1728                 0, /* don't force */
1729                 pages,
1730                 NULL);
1731         up_read(&current->mm->mmap_sem);
1732
1733         /* Errors and no page mapped should return here */
1734         if (res < nr_pages)
1735                 goto out_unmap;
1736
1737         for (i=0; i < nr_pages; i++) {
1738                 /* FIXME: flush superflous for rw==READ,
1739                  * probably wrong function for rw==WRITE
1740                  */
1741                 flush_dcache_page(pages[i]);
1742                 /* ?? Is locking needed? I don't think so */
1743                 /* if (TestSetPageLocked(pages[i]))
1744                    goto out_unlock; */
1745         }
1746
1747         sgl[0].page = pages[0];
1748         sgl[0].offset = uaddr & ~PAGE_MASK;
1749         if (nr_pages > 1) {
1750                 sgl[0].length = PAGE_SIZE - sgl[0].offset;
1751                 count -= sgl[0].length;
1752                 for (i=1; i < nr_pages ; i++) {
1753                         sgl[i].page = pages[i]; 
1754                         sgl[i].length = count < PAGE_SIZE ? count : PAGE_SIZE;
1755                         count -= PAGE_SIZE;
1756                 }
1757         }
1758         else {
1759                 sgl[0].length = count;
1760         }
1761
1762         kfree(pages);
1763         return nr_pages;
1764
1765  out_unmap:
1766         if (res > 0) {
1767                 for (j=0; j < res; j++)
1768                         page_cache_release(pages[j]);
1769                 res = 0;
1770         }
1771         kfree(pages);
1772         return res;
1773 }
1774
1775
1776 /* And unmap them... */
1777 static int 
1778 st_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_pages,
1779                     int dirtied)
1780 {
1781         int i;
1782
1783         for (i=0; i < nr_pages; i++) {
1784                 struct page *page = sgl[i].page;
1785
1786                 if (dirtied)
1787                         SetPageDirty(page);
1788                 /* unlock_page(page); */
1789                 /* FIXME: cache flush missing for rw==READ
1790                  * FIXME: call the correct reference counting function
1791                  */
1792                 page_cache_release(page);
1793         }
1794
1795         return 0;
1796 }
1797
1798 /* ^^^^^^^^  above code borrowed from st driver's direct IO ^^^^^^^^^ */
1799 #endif
1800
1801
1802 /* Returns: -ve -> error, 0 -> done, 1 -> try indirect */
1803 static int
1804 sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len)
1805 {
1806 #ifdef SG_ALLOW_DIO_CODE
1807         sg_io_hdr_t *hp = &srp->header;
1808         Sg_scatter_hold *schp = &srp->data;
1809         int sg_tablesize = sfp->parentdp->sg_tablesize;
1810         int mx_sc_elems, res;
1811         struct scsi_device *sdev = sfp->parentdp->device;
1812
1813         if (((unsigned long)hp->dxferp &
1814                         queue_dma_alignment(sdev->request_queue)) != 0)
1815                 return 1;
1816
1817         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1818         if (mx_sc_elems <= 0) {
1819                 return 1;
1820         }
1821         res = st_map_user_pages(schp->buffer, mx_sc_elems,
1822                                 (unsigned long)hp->dxferp, dxfer_len, 
1823                                 (SG_DXFER_TO_DEV == hp->dxfer_direction) ? 1 : 0);
1824         if (res <= 0) {
1825                 sg_remove_scat(schp);
1826                 return 1;
1827         }
1828         schp->k_use_sg = res;
1829         schp->dio_in_use = 1;
1830         hp->info |= SG_INFO_DIRECT_IO;
1831         return 0;
1832 #else
1833         return 1;
1834 #endif
1835 }
1836
1837 static int
1838 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1839 {
1840         struct scatterlist *sg;
1841         int ret_sz = 0, k, rem_sz, num, mx_sc_elems;
1842         int sg_tablesize = sfp->parentdp->sg_tablesize;
1843         int blk_size = buff_size;
1844         struct page *p = NULL;
1845
1846         if ((blk_size < 0) || (!sfp))
1847                 return -EFAULT;
1848         if (0 == blk_size)
1849                 ++blk_size;     /* don't know why */
1850 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1851         blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
1852         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1853                                    buff_size, blk_size));
1854
1855         /* N.B. ret_sz carried into this block ... */
1856         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1857         if (mx_sc_elems < 0)
1858                 return mx_sc_elems;     /* most likely -ENOMEM */
1859
1860         num = scatter_elem_sz;
1861         if (unlikely(num != scatter_elem_sz_prev)) {
1862                 if (num < PAGE_SIZE) {
1863                         scatter_elem_sz = PAGE_SIZE;
1864                         scatter_elem_sz_prev = PAGE_SIZE;
1865                 } else
1866                         scatter_elem_sz_prev = num;
1867         }
1868         for (k = 0, sg = schp->buffer, rem_sz = blk_size;
1869              (rem_sz > 0) && (k < mx_sc_elems);
1870              ++k, rem_sz -= ret_sz, ++sg) {
1871                 
1872                 num = (rem_sz > scatter_elem_sz_prev) ?
1873                       scatter_elem_sz_prev : rem_sz;
1874                 p = sg_page_malloc(num, sfp->low_dma, &ret_sz);
1875                 if (!p)
1876                         return -ENOMEM;
1877
1878                 if (num == scatter_elem_sz_prev) {
1879                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1880                                 scatter_elem_sz = ret_sz;
1881                                 scatter_elem_sz_prev = ret_sz;
1882                         }
1883                 }
1884                 sg->page = p;
1885                 sg->length = (ret_sz > num) ? num : ret_sz;
1886
1887                 SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k=%d, num=%d, "
1888                                  "ret_sz=%d\n", k, num, ret_sz));
1889         }               /* end of for loop */
1890
1891         schp->k_use_sg = k;
1892         SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, "
1893                          "rem_sz=%d\n", k, rem_sz));
1894
1895         schp->bufflen = blk_size;
1896         if (rem_sz > 0) /* must have failed */
1897                 return -ENOMEM;
1898
1899         return 0;
1900 }
1901
1902 static int
1903 sg_write_xfer(Sg_request * srp)
1904 {
1905         sg_io_hdr_t *hp = &srp->header;
1906         Sg_scatter_hold *schp = &srp->data;
1907         struct scatterlist *sg = schp->buffer;
1908         int num_xfer = 0;
1909         int j, k, onum, usglen, ksglen, res;
1910         int iovec_count = (int) hp->iovec_count;
1911         int dxfer_dir = hp->dxfer_direction;
1912         unsigned char *p;
1913         unsigned char __user *up;
1914         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
1915
1916         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_TO_DEV == dxfer_dir) ||
1917             (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
1918                 num_xfer = (int) (new_interface ? hp->dxfer_len : hp->flags);
1919                 if (schp->bufflen < num_xfer)
1920                         num_xfer = schp->bufflen;
1921         }
1922         if ((num_xfer <= 0) || (schp->dio_in_use) ||
1923             (new_interface
1924              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
1925                 return 0;
1926
1927         SCSI_LOG_TIMEOUT(4, printk("sg_write_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
1928                           num_xfer, iovec_count, schp->k_use_sg));
1929         if (iovec_count) {
1930                 onum = iovec_count;
1931                 if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
1932                         return -EFAULT;
1933         } else
1934                 onum = 1;
1935
1936         ksglen = sg->length;
1937         p = page_address(sg->page);
1938         for (j = 0, k = 0; j < onum; ++j) {
1939                 res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
1940                 if (res)
1941                         return res;
1942
1943                 for (; p; ++sg, ksglen = sg->length,
1944                      p = page_address(sg->page)) {
1945                         if (usglen <= 0)
1946                                 break;
1947                         if (ksglen > usglen) {
1948                                 if (usglen >= num_xfer) {
1949                                         if (__copy_from_user(p, up, num_xfer))
1950                                                 return -EFAULT;
1951                                         return 0;
1952                                 }
1953                                 if (__copy_from_user(p, up, usglen))
1954                                         return -EFAULT;
1955                                 p += usglen;
1956                                 ksglen -= usglen;
1957                                 break;
1958                         } else {
1959                                 if (ksglen >= num_xfer) {
1960                                         if (__copy_from_user(p, up, num_xfer))
1961                                                 return -EFAULT;
1962                                         return 0;
1963                                 }
1964                                 if (__copy_from_user(p, up, ksglen))
1965                                         return -EFAULT;
1966                                 up += ksglen;
1967                                 usglen -= ksglen;
1968                         }
1969                         ++k;
1970                         if (k >= schp->k_use_sg)
1971                                 return 0;
1972                 }
1973         }
1974
1975         return 0;
1976 }
1977
1978 static int
1979 sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
1980            int wr_xf, int *countp, unsigned char __user **up)
1981 {
1982         int num_xfer = (int) hp->dxfer_len;
1983         unsigned char __user *p = hp->dxferp;
1984         int count;
1985
1986         if (0 == sg_num) {
1987                 if (wr_xf && ('\0' == hp->interface_id))
1988                         count = (int) hp->flags;        /* holds "old" input_size */
1989                 else
1990                         count = num_xfer;
1991         } else {
1992                 sg_iovec_t iovec;
1993                 if (__copy_from_user(&iovec, p + ind*SZ_SG_IOVEC, SZ_SG_IOVEC))
1994                         return -EFAULT;
1995                 p = iovec.iov_base;
1996                 count = (int) iovec.iov_len;
1997         }
1998         if (!access_ok(wr_xf ? VERIFY_READ : VERIFY_WRITE, p, count))
1999                 return -EFAULT;
2000         if (up)
2001                 *up = p;
2002         if (countp)
2003                 *countp = count;
2004         return 0;
2005 }
2006
2007 static void
2008 sg_remove_scat(Sg_scatter_hold * schp)
2009 {
2010         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
2011         if (schp->buffer && (schp->sglist_len > 0)) {
2012                 struct scatterlist *sg = schp->buffer;
2013
2014                 if (schp->dio_in_use) {
2015 #ifdef SG_ALLOW_DIO_CODE
2016                         st_unmap_user_pages(sg, schp->k_use_sg, TRUE);
2017 #endif
2018                 } else {
2019                         int k;
2020
2021                         for (k = 0; (k < schp->k_use_sg) && sg->page;
2022                              ++k, ++sg) {
2023                                 SCSI_LOG_TIMEOUT(5, printk(
2024                                     "sg_remove_scat: k=%d, pg=0x%p, len=%d\n",
2025                                     k, sg->page, sg->length));
2026                                 sg_page_free(sg->page, sg->length);
2027                         }
2028                 }
2029                 kfree(schp->buffer);
2030         }
2031         memset(schp, 0, sizeof (*schp));
2032 }
2033
2034 static int
2035 sg_read_xfer(Sg_request * srp)
2036 {
2037         sg_io_hdr_t *hp = &srp->header;
2038         Sg_scatter_hold *schp = &srp->data;
2039         struct scatterlist *sg = schp->buffer;
2040         int num_xfer = 0;
2041         int j, k, onum, usglen, ksglen, res;
2042         int iovec_count = (int) hp->iovec_count;
2043         int dxfer_dir = hp->dxfer_direction;
2044         unsigned char *p;
2045         unsigned char __user *up;
2046         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
2047
2048         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_FROM_DEV == dxfer_dir)
2049             || (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
2050                 num_xfer = hp->dxfer_len;
2051                 if (schp->bufflen < num_xfer)
2052                         num_xfer = schp->bufflen;
2053         }
2054         if ((num_xfer <= 0) || (schp->dio_in_use) ||
2055             (new_interface
2056              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
2057                 return 0;
2058
2059         SCSI_LOG_TIMEOUT(4, printk("sg_read_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
2060                           num_xfer, iovec_count, schp->k_use_sg));
2061         if (iovec_count) {
2062                 onum = iovec_count;
2063                 if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
2064                         return -EFAULT;
2065         } else
2066                 onum = 1;
2067
2068         p = page_address(sg->page);
2069         ksglen = sg->length;
2070         for (j = 0, k = 0; j < onum; ++j) {
2071                 res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
2072                 if (res)
2073                         return res;
2074
2075                 for (; p; ++sg, ksglen = sg->length,
2076                      p = page_address(sg->page)) {
2077                         if (usglen <= 0)
2078                                 break;
2079                         if (ksglen > usglen) {
2080                                 if (usglen >= num_xfer) {
2081                                         if (__copy_to_user(up, p, num_xfer))
2082                                                 return -EFAULT;
2083                                         return 0;
2084                                 }
2085                                 if (__copy_to_user(up, p, usglen))
2086                                         return -EFAULT;
2087                                 p += usglen;
2088                                 ksglen -= usglen;
2089                                 break;
2090                         } else {
2091                                 if (ksglen >= num_xfer) {
2092                                         if (__copy_to_user(up, p, num_xfer))
2093                                                 return -EFAULT;
2094                                         return 0;
2095                                 }
2096                                 if (__copy_to_user(up, p, ksglen))
2097                                         return -EFAULT;
2098                                 up += ksglen;
2099                                 usglen -= ksglen;
2100                         }
2101                         ++k;
2102                         if (k >= schp->k_use_sg)
2103                                 return 0;
2104                 }
2105         }
2106
2107         return 0;
2108 }
2109
2110 static int
2111 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
2112 {
2113         Sg_scatter_hold *schp = &srp->data;
2114         struct scatterlist *sg = schp->buffer;
2115         int k, num;
2116
2117         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
2118                                    num_read_xfer));
2119         if ((!outp) || (num_read_xfer <= 0))
2120                 return 0;
2121
2122         for (k = 0; (k < schp->k_use_sg) && sg->page; ++k, ++sg) {
2123                 num = sg->length;
2124                 if (num > num_read_xfer) {
2125                         if (__copy_to_user(outp, page_address(sg->page),
2126                                            num_read_xfer))
2127                                 return -EFAULT;
2128                         break;
2129                 } else {
2130                         if (__copy_to_user(outp, page_address(sg->page),
2131                                            num))
2132                                 return -EFAULT;
2133                         num_read_xfer -= num;
2134                         if (num_read_xfer <= 0)
2135                                 break;
2136                         outp += num;
2137                 }
2138         }
2139
2140         return 0;
2141 }
2142
2143 static void
2144 sg_build_reserve(Sg_fd * sfp, int req_size)
2145 {
2146         Sg_scatter_hold *schp = &sfp->reserve;
2147
2148         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
2149         do {
2150                 if (req_size < PAGE_SIZE)
2151                         req_size = PAGE_SIZE;
2152                 if (0 == sg_build_indirect(schp, sfp, req_size))
2153                         return;
2154                 else
2155                         sg_remove_scat(schp);
2156                 req_size >>= 1; /* divide by 2 */
2157         } while (req_size > (PAGE_SIZE / 2));
2158 }
2159
2160 static void
2161 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2162 {
2163         Sg_scatter_hold *req_schp = &srp->data;
2164         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2165         struct scatterlist *sg = rsv_schp->buffer;
2166         int k, num, rem;
2167
2168         srp->res_used = 1;
2169         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
2170         rem = size;
2171
2172         for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sg) {
2173                 num = sg->length;
2174                 if (rem <= num) {
2175                         sfp->save_scat_len = num;
2176                         sg->length = rem;
2177                         req_schp->k_use_sg = k + 1;
2178                         req_schp->sglist_len = rsv_schp->sglist_len;
2179                         req_schp->buffer = rsv_schp->buffer;
2180
2181                         req_schp->bufflen = size;
2182                         req_schp->b_malloc_len = rsv_schp->b_malloc_len;
2183                         break;
2184                 } else
2185                         rem -= num;
2186         }
2187
2188         if (k >= rsv_schp->k_use_sg)
2189                 SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
2190 }
2191
2192 static void
2193 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2194 {
2195         Sg_scatter_hold *req_schp = &srp->data;
2196         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2197
2198         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
2199                                    (int) req_schp->k_use_sg));
2200         if ((rsv_schp->k_use_sg > 0) && (req_schp->k_use_sg > 0)) {
2201                 struct scatterlist *sg = rsv_schp->buffer;
2202
2203                 if (sfp->save_scat_len > 0)
2204                         (sg + (req_schp->k_use_sg - 1))->length =
2205                             (unsigned) sfp->save_scat_len;
2206                 else
2207                         SCSI_LOG_TIMEOUT(1, printk ("sg_unlink_reserve: BAD save_scat_len\n"));
2208         }
2209         req_schp->k_use_sg = 0;
2210         req_schp->bufflen = 0;
2211         req_schp->buffer = NULL;
2212         req_schp->sglist_len = 0;
2213         sfp->save_scat_len = 0;
2214         srp->res_used = 0;
2215 }
2216
2217 static Sg_request *
2218 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2219 {
2220         Sg_request *resp;
2221         unsigned long iflags;
2222
2223         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2224         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2225                 /* look for requests that are ready + not SG_IO owned */
2226                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2227                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2228                         resp->done = 2; /* guard against other readers */
2229                         break;
2230                 }
2231         }
2232         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2233         return resp;
2234 }
2235
2236 #ifdef CONFIG_SCSI_PROC_FS
2237 static Sg_request *
2238 sg_get_nth_request(Sg_fd * sfp, int nth)
2239 {
2240         Sg_request *resp;
2241         unsigned long iflags;
2242         int k;
2243
2244         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2245         for (k = 0, resp = sfp->headrp; resp && (k < nth);
2246              ++k, resp = resp->nextrp) ;
2247         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2248         return resp;
2249 }
2250 #endif
2251
2252 /* always adds to end of list */
2253 static Sg_request *
2254 sg_add_request(Sg_fd * sfp)
2255 {
2256         int k;
2257         unsigned long iflags;
2258         Sg_request *resp;
2259         Sg_request *rp = sfp->req_arr;
2260
2261         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2262         resp = sfp->headrp;
2263         if (!resp) {
2264                 memset(rp, 0, sizeof (Sg_request));
2265                 rp->parentfp = sfp;
2266                 resp = rp;
2267                 sfp->headrp = resp;
2268         } else {
2269                 if (0 == sfp->cmd_q)
2270                         resp = NULL;    /* command queuing disallowed */
2271                 else {
2272                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2273                                 if (!rp->parentfp)
2274                                         break;
2275                         }
2276                         if (k < SG_MAX_QUEUE) {
2277                                 memset(rp, 0, sizeof (Sg_request));
2278                                 rp->parentfp = sfp;
2279                                 while (resp->nextrp)
2280                                         resp = resp->nextrp;
2281                                 resp->nextrp = rp;
2282                                 resp = rp;
2283                         } else
2284                                 resp = NULL;
2285                 }
2286         }
2287         if (resp) {
2288                 resp->nextrp = NULL;
2289                 resp->header.duration = jiffies_to_msecs(jiffies);
2290         }
2291         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2292         return resp;
2293 }
2294
2295 /* Return of 1 for found; 0 for not found */
2296 static int
2297 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2298 {
2299         Sg_request *prev_rp;
2300         Sg_request *rp;
2301         unsigned long iflags;
2302         int res = 0;
2303
2304         if ((!sfp) || (!srp) || (!sfp->headrp))
2305                 return res;
2306         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2307         prev_rp = sfp->headrp;
2308         if (srp == prev_rp) {
2309                 sfp->headrp = prev_rp->nextrp;
2310                 prev_rp->parentfp = NULL;
2311                 res = 1;
2312         } else {
2313                 while ((rp = prev_rp->nextrp)) {
2314                         if (srp == rp) {
2315                                 prev_rp->nextrp = rp->nextrp;
2316                                 rp->parentfp = NULL;
2317                                 res = 1;
2318                                 break;
2319                         }
2320                         prev_rp = rp;
2321                 }
2322         }
2323         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2324         return res;
2325 }
2326
2327 #ifdef CONFIG_SCSI_PROC_FS
2328 static Sg_fd *
2329 sg_get_nth_sfp(Sg_device * sdp, int nth)
2330 {
2331         Sg_fd *resp;
2332         unsigned long iflags;
2333         int k;
2334
2335         read_lock_irqsave(&sg_dev_arr_lock, iflags);
2336         for (k = 0, resp = sdp->headfp; resp && (k < nth);
2337              ++k, resp = resp->nextfp) ;
2338         read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2339         return resp;
2340 }
2341 #endif
2342
2343 static Sg_fd *
2344 sg_add_sfp(Sg_device * sdp, int dev)
2345 {
2346         Sg_fd *sfp;
2347         unsigned long iflags;
2348         int bufflen;
2349
2350         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2351         if (!sfp)
2352                 return NULL;
2353
2354         init_waitqueue_head(&sfp->read_wait);
2355         rwlock_init(&sfp->rq_list_lock);
2356
2357         sfp->timeout = SG_DEFAULT_TIMEOUT;
2358         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2359         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2360         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2361             sdp->device->host->unchecked_isa_dma : 1;
2362         sfp->cmd_q = SG_DEF_COMMAND_Q;
2363         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2364         sfp->parentdp = sdp;
2365         write_lock_irqsave(&sg_dev_arr_lock, iflags);
2366         if (!sdp->headfp)
2367                 sdp->headfp = sfp;
2368         else {                  /* add to tail of existing list */
2369                 Sg_fd *pfp = sdp->headfp;
2370                 while (pfp->nextfp)
2371                         pfp = pfp->nextfp;
2372                 pfp->nextfp = sfp;
2373         }
2374         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2375         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2376         if (unlikely(sg_big_buff != def_reserved_size))
2377                 sg_big_buff = def_reserved_size;
2378
2379         bufflen = min_t(int, sg_big_buff,
2380                         sdp->device->request_queue->max_sectors * 512);
2381         sg_build_reserve(sfp, bufflen);
2382         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2383                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2384         return sfp;
2385 }
2386
2387 static void
2388 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2389 {
2390         Sg_fd *fp;
2391         Sg_fd *prev_fp;
2392
2393         prev_fp = sdp->headfp;
2394         if (sfp == prev_fp)
2395                 sdp->headfp = prev_fp->nextfp;
2396         else {
2397                 while ((fp = prev_fp->nextfp)) {
2398                         if (sfp == fp) {
2399                                 prev_fp->nextfp = fp->nextfp;
2400                                 break;
2401                         }
2402                         prev_fp = fp;
2403                 }
2404         }
2405         if (sfp->reserve.bufflen > 0) {
2406                 SCSI_LOG_TIMEOUT(6, 
2407                         printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2408                         (int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2409                 sg_remove_scat(&sfp->reserve);
2410         }
2411         sfp->parentdp = NULL;
2412         SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2413         kfree(sfp);
2414 }
2415
2416 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2417 static int
2418 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2419 {
2420         Sg_request *srp;
2421         Sg_request *tsrp;
2422         int dirty = 0;
2423         int res = 0;
2424
2425         for (srp = sfp->headrp; srp; srp = tsrp) {
2426                 tsrp = srp->nextrp;
2427                 if (sg_srp_done(srp, sfp))
2428                         sg_finish_rem_req(srp);
2429                 else
2430                         ++dirty;
2431         }
2432         if (0 == dirty) {
2433                 unsigned long iflags;
2434
2435                 write_lock_irqsave(&sg_dev_arr_lock, iflags);
2436                 __sg_remove_sfp(sdp, sfp);
2437                 if (sdp->detached && (NULL == sdp->headfp)) {
2438                         int k, maxd;
2439
2440                         maxd = sg_dev_max;
2441                         for (k = 0; k < maxd; ++k) {
2442                                 if (sdp == sg_dev_arr[k])
2443                                         break;
2444                         }
2445                         if (k < maxd)
2446                                 sg_dev_arr[k] = NULL;
2447                         kfree((char *) sdp);
2448                         res = 1;
2449                 }
2450                 write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2451         } else {
2452                 /* MOD_INC's to inhibit unloading sg and associated adapter driver */
2453                 /* only bump the access_count if we actually succeeded in
2454                  * throwing another counter on the host module */
2455                 scsi_device_get(sdp->device);   /* XXX: retval ignored? */      
2456                 sfp->closed = 1;        /* flag dirty state on this fd */
2457                 SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2458                                   dirty));
2459         }
2460         return res;
2461 }
2462
2463 static int
2464 sg_res_in_use(Sg_fd * sfp)
2465 {
2466         const Sg_request *srp;
2467         unsigned long iflags;
2468
2469         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2470         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2471                 if (srp->res_used)
2472                         break;
2473         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2474         return srp ? 1 : 0;
2475 }
2476
2477 /* The size fetched (value output via retSzp) set when non-NULL return */
2478 static struct page *
2479 sg_page_malloc(int rqSz, int lowDma, int *retSzp)
2480 {
2481         struct page *resp = NULL;
2482         gfp_t page_mask;
2483         int order, a_size;
2484         int resSz;
2485
2486         if ((rqSz <= 0) || (NULL == retSzp))
2487                 return resp;
2488
2489         if (lowDma)
2490                 page_mask = GFP_ATOMIC | GFP_DMA | __GFP_COMP | __GFP_NOWARN;
2491         else
2492                 page_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
2493
2494         for (order = 0, a_size = PAGE_SIZE; a_size < rqSz;
2495              order++, a_size <<= 1) ;
2496         resSz = a_size;         /* rounded up if necessary */
2497         resp = alloc_pages(page_mask, order);
2498         while ((!resp) && order) {
2499                 --order;
2500                 a_size >>= 1;   /* divide by 2, until PAGE_SIZE */
2501                 resp =  alloc_pages(page_mask, order);  /* try half */
2502                 resSz = a_size;
2503         }
2504         if (resp) {
2505                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2506                         memset(page_address(resp), 0, resSz);
2507                 *retSzp = resSz;
2508         }
2509         return resp;
2510 }
2511
2512 static void
2513 sg_page_free(struct page *page, int size)
2514 {
2515         int order, a_size;
2516
2517         if (!page)
2518                 return;
2519         for (order = 0, a_size = PAGE_SIZE; a_size < size;
2520              order++, a_size <<= 1) ;
2521         __free_pages(page, order);
2522 }
2523
2524 #ifndef MAINTENANCE_IN_CMD
2525 #define MAINTENANCE_IN_CMD 0xa3
2526 #endif
2527
2528 static unsigned char allow_ops[] = { TEST_UNIT_READY, REQUEST_SENSE,
2529         INQUIRY, READ_CAPACITY, READ_BUFFER, READ_6, READ_10, READ_12,
2530         READ_16, MODE_SENSE, MODE_SENSE_10, LOG_SENSE, REPORT_LUNS,
2531         SERVICE_ACTION_IN, RECEIVE_DIAGNOSTIC, READ_LONG, MAINTENANCE_IN_CMD
2532 };
2533
2534 static int
2535 sg_allow_access(unsigned char opcode, char dev_type)
2536 {
2537         int k;
2538
2539         if (TYPE_SCANNER == dev_type)   /* TYPE_ROM maybe burner */
2540                 return 1;
2541         for (k = 0; k < sizeof (allow_ops); ++k) {
2542                 if (opcode == allow_ops[k])
2543                         return 1;
2544         }
2545         return 0;
2546 }
2547
2548 #ifdef CONFIG_SCSI_PROC_FS
2549 static int
2550 sg_last_dev(void)
2551 {
2552         int k;
2553         unsigned long iflags;
2554
2555         read_lock_irqsave(&sg_dev_arr_lock, iflags);
2556         for (k = sg_dev_max - 1; k >= 0; --k)
2557                 if (sg_dev_arr[k] && sg_dev_arr[k]->device)
2558                         break;
2559         read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2560         return k + 1;           /* origin 1 */
2561 }
2562 #endif
2563
2564 static Sg_device *
2565 sg_get_dev(int dev)
2566 {
2567         Sg_device *sdp = NULL;
2568         unsigned long iflags;
2569
2570         if (sg_dev_arr && (dev >= 0)) {
2571                 read_lock_irqsave(&sg_dev_arr_lock, iflags);
2572                 if (dev < sg_dev_max)
2573                         sdp = sg_dev_arr[dev];
2574                 read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2575         }
2576         return sdp;
2577 }
2578
2579 #ifdef CONFIG_SCSI_PROC_FS
2580
2581 static struct proc_dir_entry *sg_proc_sgp = NULL;
2582
2583 static char sg_proc_sg_dirname[] = "scsi/sg";
2584
2585 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2586
2587 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2588 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2589                                   size_t count, loff_t *off);
2590 static struct file_operations adio_fops = {
2591         /* .owner, .read and .llseek added in sg_proc_init() */
2592         .open = sg_proc_single_open_adio,
2593         .write = sg_proc_write_adio,
2594         .release = single_release,
2595 };
2596
2597 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2598 static ssize_t sg_proc_write_dressz(struct file *filp, 
2599                 const char __user *buffer, size_t count, loff_t *off);
2600 static struct file_operations dressz_fops = {
2601         .open = sg_proc_single_open_dressz,
2602         .write = sg_proc_write_dressz,
2603         .release = single_release,
2604 };
2605
2606 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2607 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2608 static struct file_operations version_fops = {
2609         .open = sg_proc_single_open_version,
2610         .release = single_release,
2611 };
2612
2613 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2614 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2615 static struct file_operations devhdr_fops = {
2616         .open = sg_proc_single_open_devhdr,
2617         .release = single_release,
2618 };
2619
2620 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2621 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2622 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2623 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2624 static void dev_seq_stop(struct seq_file *s, void *v);
2625 static struct file_operations dev_fops = {
2626         .open = sg_proc_open_dev,
2627         .release = seq_release,
2628 };
2629 static struct seq_operations dev_seq_ops = {
2630         .start = dev_seq_start,
2631         .next  = dev_seq_next,
2632         .stop  = dev_seq_stop,
2633         .show  = sg_proc_seq_show_dev,
2634 };
2635
2636 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2637 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2638 static struct file_operations devstrs_fops = {
2639         .open = sg_proc_open_devstrs,
2640         .release = seq_release,
2641 };
2642 static struct seq_operations devstrs_seq_ops = {
2643         .start = dev_seq_start,
2644         .next  = dev_seq_next,
2645         .stop  = dev_seq_stop,
2646         .show  = sg_proc_seq_show_devstrs,
2647 };
2648
2649 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2650 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2651 static struct file_operations debug_fops = {
2652         .open = sg_proc_open_debug,
2653         .release = seq_release,
2654 };
2655 static struct seq_operations debug_seq_ops = {
2656         .start = dev_seq_start,
2657         .next  = dev_seq_next,
2658         .stop  = dev_seq_stop,
2659         .show  = sg_proc_seq_show_debug,
2660 };
2661
2662
2663 struct sg_proc_leaf {
2664         const char * name;
2665         struct file_operations * fops;
2666 };
2667
2668 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2669         {"allow_dio", &adio_fops},
2670         {"debug", &debug_fops},
2671         {"def_reserved_size", &dressz_fops},
2672         {"device_hdr", &devhdr_fops},
2673         {"devices", &dev_fops},
2674         {"device_strs", &devstrs_fops},
2675         {"version", &version_fops}
2676 };
2677
2678 static int
2679 sg_proc_init(void)
2680 {
2681         int k, mask;
2682         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2683         struct proc_dir_entry *pdep;
2684         struct sg_proc_leaf * leaf;
2685
2686         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2687         if (!sg_proc_sgp)
2688                 return 1;
2689         for (k = 0; k < num_leaves; ++k) {
2690                 leaf = &sg_proc_leaf_arr[k];
2691                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2692                 pdep = create_proc_entry(leaf->name, mask, sg_proc_sgp);
2693                 if (pdep) {
2694                         leaf->fops->owner = THIS_MODULE,
2695                         leaf->fops->read = seq_read,
2696                         leaf->fops->llseek = seq_lseek,
2697                         pdep->proc_fops = leaf->fops;
2698                 }
2699         }
2700         return 0;
2701 }
2702
2703 static void
2704 sg_proc_cleanup(void)
2705 {
2706         int k;
2707         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2708
2709         if (!sg_proc_sgp)
2710                 return;
2711         for (k = 0; k < num_leaves; ++k)
2712                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2713         remove_proc_entry(sg_proc_sg_dirname, NULL);
2714 }
2715
2716
2717 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2718 {
2719         seq_printf(s, "%d\n", *((int *)s->private));
2720         return 0;
2721 }
2722
2723 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2724 {
2725         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2726 }
2727
2728 static ssize_t 
2729 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2730                    size_t count, loff_t *off)
2731 {
2732         int num;
2733         char buff[11];
2734
2735         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2736                 return -EACCES;
2737         num = (count < 10) ? count : 10;
2738         if (copy_from_user(buff, buffer, num))
2739                 return -EFAULT;
2740         buff[num] = '\0';
2741         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2742         return count;
2743 }
2744
2745 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2746 {
2747         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2748 }
2749
2750 static ssize_t 
2751 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2752                      size_t count, loff_t *off)
2753 {
2754         int num;
2755         unsigned long k = ULONG_MAX;
2756         char buff[11];
2757
2758         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2759                 return -EACCES;
2760         num = (count < 10) ? count : 10;
2761         if (copy_from_user(buff, buffer, num))
2762                 return -EFAULT;
2763         buff[num] = '\0';
2764         k = simple_strtoul(buff, NULL, 10);
2765         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2766                 sg_big_buff = k;
2767                 return count;
2768         }
2769         return -ERANGE;
2770 }
2771
2772 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2773 {
2774         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2775                    sg_version_date);
2776         return 0;
2777 }
2778
2779 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2780 {
2781         return single_open(file, sg_proc_seq_show_version, NULL);
2782 }
2783
2784 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2785 {
2786         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2787                    "online\n");
2788         return 0;
2789 }
2790
2791 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2792 {
2793         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2794 }
2795
2796 struct sg_proc_deviter {
2797         loff_t  index;
2798         size_t  max;
2799 };
2800
2801 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2802 {
2803         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2804
2805         s->private = it;
2806         if (! it)
2807                 return NULL;
2808
2809         if (NULL == sg_dev_arr)
2810                 return NULL;
2811         it->index = *pos;
2812         it->max = sg_last_dev();
2813         if (it->index >= it->max)
2814                 return NULL;
2815         return it;
2816 }
2817
2818 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2819 {
2820         struct sg_proc_deviter * it = s->private;
2821
2822         *pos = ++it->index;
2823         return (it->index < it->max) ? it : NULL;
2824 }
2825
2826 static void dev_seq_stop(struct seq_file *s, void *v)
2827 {
2828         kfree(s->private);
2829 }
2830
2831 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2832 {
2833         return seq_open(file, &dev_seq_ops);
2834 }
2835
2836 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2837 {
2838         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2839         Sg_device *sdp;
2840         struct scsi_device *scsidp;
2841
2842         sdp = it ? sg_get_dev(it->index) : NULL;
2843         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2844                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2845                               scsidp->host->host_no, scsidp->channel,
2846                               scsidp->id, scsidp->lun, (int) scsidp->type,
2847                               1,
2848                               (int) scsidp->queue_depth,
2849                               (int) scsidp->device_busy,
2850                               (int) scsi_device_online(scsidp));
2851         else
2852                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2853         return 0;
2854 }
2855
2856 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2857 {
2858         return seq_open(file, &devstrs_seq_ops);
2859 }
2860
2861 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2862 {
2863         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2864         Sg_device *sdp;
2865         struct scsi_device *scsidp;
2866
2867         sdp = it ? sg_get_dev(it->index) : NULL;
2868         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2869                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2870                            scsidp->vendor, scsidp->model, scsidp->rev);
2871         else
2872                 seq_printf(s, "<no active device>\n");
2873         return 0;
2874 }
2875
2876 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2877 {
2878         int k, m, new_interface, blen, usg;
2879         Sg_request *srp;
2880         Sg_fd *fp;
2881         const sg_io_hdr_t *hp;
2882         const char * cp;
2883         unsigned int ms;
2884
2885         for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
2886                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2887                            "(res)sgat=%d low_dma=%d\n", k + 1,
2888                            jiffies_to_msecs(fp->timeout),
2889                            fp->reserve.bufflen,
2890                            (int) fp->reserve.k_use_sg,
2891                            (int) fp->low_dma);
2892                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2893                            (int) fp->cmd_q, (int) fp->force_packid,
2894                            (int) fp->keep_orphan, (int) fp->closed);
2895                 for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
2896                         hp = &srp->header;
2897                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2898                         if (srp->res_used) {
2899                                 if (new_interface && 
2900                                     (SG_FLAG_MMAP_IO & hp->flags))
2901                                         cp = "     mmap>> ";
2902                                 else
2903                                         cp = "     rb>> ";
2904                         } else {
2905                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2906                                         cp = "     dio>> ";
2907                                 else
2908                                         cp = "     ";
2909                         }
2910                         seq_printf(s, cp);
2911                         blen = srp->data.bufflen;
2912                         usg = srp->data.k_use_sg;
2913                         seq_printf(s, srp->done ? 
2914                                    ((1 == srp->done) ?  "rcv:" : "fin:")
2915                                    : "act:");
2916                         seq_printf(s, " id=%d blen=%d",
2917                                    srp->header.pack_id, blen);
2918                         if (srp->done)
2919                                 seq_printf(s, " dur=%d", hp->duration);
2920                         else {
2921                                 ms = jiffies_to_msecs(jiffies);
2922                                 seq_printf(s, " t_o/elap=%d/%d",
2923                                         (new_interface ? hp->timeout :
2924                                                   jiffies_to_msecs(fp->timeout)),
2925                                         (ms > hp->duration ? ms - hp->duration : 0));
2926                         }
2927                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2928                                    (int) srp->data.cmd_opcode);
2929                 }
2930                 if (0 == m)
2931                         seq_printf(s, "     No requests active\n");
2932         }
2933 }
2934
2935 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2936 {
2937         return seq_open(file, &debug_seq_ops);
2938 }
2939
2940 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2941 {
2942         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2943         Sg_device *sdp;
2944
2945         if (it && (0 == it->index)) {
2946                 seq_printf(s, "dev_max(currently)=%d max_active_device=%d "
2947                            "(origin 1)\n", sg_dev_max, (int)it->max);
2948                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2949         }
2950         sdp = it ? sg_get_dev(it->index) : NULL;
2951         if (sdp) {
2952                 struct scsi_device *scsidp = sdp->device;
2953
2954                 if (NULL == scsidp) {
2955                         seq_printf(s, "device %d detached ??\n", 
2956                                    (int)it->index);
2957                         return 0;
2958                 }
2959
2960                 if (sg_get_nth_sfp(sdp, 0)) {
2961                         seq_printf(s, " >>> device=%s ",
2962                                 sdp->disk->disk_name);
2963                         if (sdp->detached)
2964                                 seq_printf(s, "detached pending close ");
2965                         else
2966                                 seq_printf
2967                                     (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2968                                      scsidp->host->host_no,
2969                                      scsidp->channel, scsidp->id,
2970                                      scsidp->lun,
2971                                      scsidp->host->hostt->emulated);
2972                         seq_printf(s, " sg_tablesize=%d excl=%d\n",
2973                                    sdp->sg_tablesize, sdp->exclude);
2974                 }
2975                 sg_proc_debug_helper(s, sdp);
2976         }
2977         return 0;
2978 }
2979
2980 #endif                          /* CONFIG_SCSI_PROC_FS */
2981
2982 module_init(init_sg);
2983 module_exit(exit_sg);