[SCSI] unify SCSI_IOCTL_SEND_COMMAND implementations
[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 = 30533;      /* 2 digits for each component */
22 #define SG_VERSION_STR "3.5.33"
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/config.h>
32 #include <linux/module.h>
33
34 #include <linux/fs.h>
35 #include <linux/kernel.h>
36 #include <linux/sched.h>
37 #include <linux/string.h>
38 #include <linux/mm.h>
39 #include <linux/errno.h>
40 #include <linux/mtio.h>
41 #include <linux/ioctl.h>
42 #include <linux/fcntl.h>
43 #include <linux/init.h>
44 #include <linux/poll.h>
45 #include <linux/smp_lock.h>
46 #include <linux/moduleparam.h>
47 #include <linux/cdev.h>
48 #include <linux/seq_file.h>
49 #include <linux/blkdev.h>
50 #include <linux/delay.h>
51 #include <linux/scatterlist.h>
52
53 #include "scsi.h"
54 #include <scsi/scsi_dbg.h>
55 #include <scsi/scsi_host.h>
56 #include <scsi/scsi_driver.h>
57 #include <scsi/scsi_ioctl.h>
58 #include <scsi/sg.h>
59
60 #include "scsi_logging.h"
61
62 #ifdef CONFIG_SCSI_PROC_FS
63 #include <linux/proc_fs.h>
64 static char *sg_version_date = "20050908";
65
66 static int sg_proc_init(void);
67 static void sg_proc_cleanup(void);
68 #endif
69
70 #define SG_ALLOW_DIO_DEF 0
71 #define SG_ALLOW_DIO_CODE /* compile out by commenting this define */
72
73 #define SG_MAX_DEVS 32768
74
75 /*
76  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
77  * Then when using 32 bit integers x * m may overflow during the calculation.
78  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
79  * calculates the same, but prevents the overflow when both m and d
80  * are "small" numbers (like HZ and USER_HZ).
81  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
82  * in 32 bits.
83  */
84 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
85
86 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
87
88 int sg_big_buff = SG_DEF_RESERVED_SIZE;
89 /* N.B. This variable is readable and writeable via
90    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
91    of this size (or less if there is not enough memory) will be reserved
92    for use by this file descriptor. [Deprecated usage: this variable is also
93    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
94    the kernel (i.e. it is not a module).] */
95 static int def_reserved_size = -1;      /* picks up init parameter */
96 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
97
98 #define SG_SECTOR_SZ 512
99 #define SG_SECTOR_MSK (SG_SECTOR_SZ - 1)
100
101 #define SG_DEV_ARR_LUMP 32      /* amount to over allocate sg_dev_arr by */
102
103 static int sg_add(struct class_device *, struct class_interface *);
104 static void sg_remove(struct class_device *, struct class_interface *);
105
106 static DEFINE_RWLOCK(sg_dev_arr_lock);  /* Also used to lock
107                                                            file descriptor list for device */
108
109 static struct class_interface sg_interface = {
110         .add            = sg_add,
111         .remove         = sg_remove,
112 };
113
114 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
115         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
116         unsigned short sglist_len; /* size of malloc'd scatter-gather list ++ */
117         unsigned bufflen;       /* Size of (aggregate) data buffer */
118         unsigned b_malloc_len;  /* actual len malloc'ed in buffer */
119         struct scatterlist *buffer;/* scatter list */
120         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
121         unsigned char cmd_opcode; /* first byte of command */
122 } Sg_scatter_hold;
123
124 struct sg_device;               /* forward declarations */
125 struct sg_fd;
126
127 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
128         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
129         struct sg_fd *parentfp; /* NULL -> not in use */
130         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
131         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
132         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
133         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
134         char orphan;            /* 1 -> drop on sight, 0 -> normal */
135         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
136         volatile char done;     /* 0->before bh, 1->before read, 2->read */
137 } Sg_request;
138
139 typedef struct sg_fd {          /* holds the state of a file descriptor */
140         struct sg_fd *nextfp;   /* NULL when last opened fd on this device */
141         struct sg_device *parentdp;     /* owning device */
142         wait_queue_head_t read_wait;    /* queue read until command done */
143         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
144         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
145         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
146         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
147         unsigned save_scat_len; /* original length of trunc. scat. element */
148         Sg_request *headrp;     /* head of request slist, NULL->empty */
149         struct fasync_struct *async_qp; /* used by asynchronous notification */
150         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
151         char low_dma;           /* as in parent but possibly overridden to 1 */
152         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
153         volatile char closed;   /* 1 -> fd closed but request(s) outstanding */
154         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
155         char next_cmd_len;      /* 0 -> automatic (def), >0 -> use on next write() */
156         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
157         char mmap_called;       /* 0 -> mmap() never called on this fd */
158 } Sg_fd;
159
160 typedef struct sg_device { /* holds the state of each scsi generic device */
161         struct scsi_device *device;
162         wait_queue_head_t o_excl_wait;  /* queue open() when O_EXCL in use */
163         int sg_tablesize;       /* adapter's max scatter-gather table size */
164         Sg_fd *headfp;          /* first open fd belonging to this device */
165         volatile char detached; /* 0->attached, 1->detached pending removal */
166         volatile char exclude;  /* opened for exclusive access */
167         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
168         struct gendisk *disk;
169         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
170 } Sg_device;
171
172 static int sg_fasync(int fd, struct file *filp, int mode);
173 /* tasklet or soft irq callback */
174 static void sg_cmd_done(void *data, char *sense, int result, int resid);
175 static int sg_start_req(Sg_request * srp);
176 static void sg_finish_rem_req(Sg_request * srp);
177 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
178 static int sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp,
179                          int tablesize);
180 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
181                            Sg_request * srp);
182 static ssize_t sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
183                             int blocking, int read_only, Sg_request ** o_srp);
184 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
185                            unsigned char *cmnd, int timeout, int blocking);
186 static int sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
187                       int wr_xf, int *countp, unsigned char __user **up);
188 static int sg_write_xfer(Sg_request * srp);
189 static int sg_read_xfer(Sg_request * srp);
190 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
191 static void sg_remove_scat(Sg_scatter_hold * schp);
192 static void sg_build_reserve(Sg_fd * sfp, int req_size);
193 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
194 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
195 static struct page *sg_page_malloc(int rqSz, int lowDma, int *retSzp);
196 static void sg_page_free(struct page *page, int size);
197 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
198 static int sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
199 static void __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
200 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
201 static Sg_request *sg_add_request(Sg_fd * sfp);
202 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
203 static int sg_res_in_use(Sg_fd * sfp);
204 static int sg_allow_access(unsigned char opcode, char dev_type);
205 static int sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len);
206 static Sg_device *sg_get_dev(int dev);
207 #ifdef CONFIG_SCSI_PROC_FS
208 static int sg_last_dev(void);
209 #endif
210
211 static Sg_device **sg_dev_arr = NULL;
212 static int sg_dev_max;
213 static int sg_nr_dev;
214
215 #define SZ_SG_HEADER sizeof(struct sg_header)
216 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
217 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
218 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
219
220 static int
221 sg_open(struct inode *inode, struct file *filp)
222 {
223         int dev = iminor(inode);
224         int flags = filp->f_flags;
225         struct request_queue *q;
226         Sg_device *sdp;
227         Sg_fd *sfp;
228         int res;
229         int retval;
230
231         nonseekable_open(inode, filp);
232         SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
233         sdp = sg_get_dev(dev);
234         if ((!sdp) || (!sdp->device))
235                 return -ENXIO;
236         if (sdp->detached)
237                 return -ENODEV;
238
239         /* This driver's module count bumped by fops_get in <linux/fs.h> */
240         /* Prevent the device driver from vanishing while we sleep */
241         retval = scsi_device_get(sdp->device);
242         if (retval)
243                 return retval;
244
245         if (!((flags & O_NONBLOCK) ||
246               scsi_block_when_processing_errors(sdp->device))) {
247                 retval = -ENXIO;
248                 /* we are in error recovery for this device */
249                 goto error_out;
250         }
251
252         if (flags & O_EXCL) {
253                 if (O_RDONLY == (flags & O_ACCMODE)) {
254                         retval = -EPERM; /* Can't lock it with read only access */
255                         goto error_out;
256                 }
257                 if (sdp->headfp && (flags & O_NONBLOCK)) {
258                         retval = -EBUSY;
259                         goto error_out;
260                 }
261                 res = 0;
262                 __wait_event_interruptible(sdp->o_excl_wait,
263                         ((sdp->headfp || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
264                 if (res) {
265                         retval = res;   /* -ERESTARTSYS because signal hit process */
266                         goto error_out;
267                 }
268         } else if (sdp->exclude) {      /* some other fd has an exclusive lock on dev */
269                 if (flags & O_NONBLOCK) {
270                         retval = -EBUSY;
271                         goto error_out;
272                 }
273                 res = 0;
274                 __wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
275                                            res);
276                 if (res) {
277                         retval = res;   /* -ERESTARTSYS because signal hit process */
278                         goto error_out;
279                 }
280         }
281         if (sdp->detached) {
282                 retval = -ENODEV;
283                 goto error_out;
284         }
285         if (!sdp->headfp) {     /* no existing opens on this device */
286                 sdp->sgdebug = 0;
287                 q = sdp->device->request_queue;
288                 sdp->sg_tablesize = min(q->max_hw_segments,
289                                         q->max_phys_segments);
290         }
291         if ((sfp = sg_add_sfp(sdp, dev)))
292                 filp->private_data = sfp;
293         else {
294                 if (flags & O_EXCL)
295                         sdp->exclude = 0;       /* undo if error */
296                 retval = -ENOMEM;
297                 goto error_out;
298         }
299         return 0;
300
301       error_out:
302         scsi_device_put(sdp->device);
303         return retval;
304 }
305
306 /* Following function was formerly called 'sg_close' */
307 static int
308 sg_release(struct inode *inode, struct file *filp)
309 {
310         Sg_device *sdp;
311         Sg_fd *sfp;
312
313         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
314                 return -ENXIO;
315         SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
316         sg_fasync(-1, filp, 0); /* remove filp from async notification list */
317         if (0 == sg_remove_sfp(sdp, sfp)) {     /* Returns 1 when sdp gone */
318                 if (!sdp->detached) {
319                         scsi_device_put(sdp->device);
320                 }
321                 sdp->exclude = 0;
322                 wake_up_interruptible(&sdp->o_excl_wait);
323         }
324         return 0;
325 }
326
327 static ssize_t
328 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
329 {
330         Sg_device *sdp;
331         Sg_fd *sfp;
332         Sg_request *srp;
333         int req_pack_id = -1;
334         sg_io_hdr_t *hp;
335         struct sg_header *old_hdr = NULL;
336         int retval = 0;
337
338         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
339                 return -ENXIO;
340         SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
341                                    sdp->disk->disk_name, (int) count));
342
343         if (!access_ok(VERIFY_WRITE, buf, count))
344                 return -EFAULT;
345         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
346                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
347                 if (!old_hdr)
348                         return -ENOMEM;
349                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
350                         retval = -EFAULT;
351                         goto free_old_hdr;
352                 }
353                 if (old_hdr->reply_len < 0) {
354                         if (count >= SZ_SG_IO_HDR) {
355                                 sg_io_hdr_t *new_hdr;
356                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
357                                 if (!new_hdr) {
358                                         retval = -ENOMEM;
359                                         goto free_old_hdr;
360                                 }
361                                 retval =__copy_from_user
362                                     (new_hdr, buf, SZ_SG_IO_HDR);
363                                 req_pack_id = new_hdr->pack_id;
364                                 kfree(new_hdr);
365                                 if (retval) {
366                                         retval = -EFAULT;
367                                         goto free_old_hdr;
368                                 }
369                         }
370                 } else
371                         req_pack_id = old_hdr->pack_id;
372         }
373         srp = sg_get_rq_mark(sfp, req_pack_id);
374         if (!srp) {             /* now wait on packet to arrive */
375                 if (sdp->detached) {
376                         retval = -ENODEV;
377                         goto free_old_hdr;
378                 }
379                 if (filp->f_flags & O_NONBLOCK) {
380                         retval = -EAGAIN;
381                         goto free_old_hdr;
382                 }
383                 while (1) {
384                         retval = 0; /* following macro beats race condition */
385                         __wait_event_interruptible(sfp->read_wait,
386                                 (sdp->detached ||
387                                 (srp = sg_get_rq_mark(sfp, req_pack_id))), 
388                                 retval);
389                         if (sdp->detached) {
390                                 retval = -ENODEV;
391                                 goto free_old_hdr;
392                         }
393                         if (0 == retval)
394                                 break;
395
396                         /* -ERESTARTSYS as signal hit process */
397                         goto free_old_hdr;
398                 }
399         }
400         if (srp->header.interface_id != '\0') {
401                 retval = sg_new_read(sfp, buf, count, srp);
402                 goto free_old_hdr;
403         }
404
405         hp = &srp->header;
406         if (old_hdr == NULL) {
407                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
408                 if (! old_hdr) {
409                         retval = -ENOMEM;
410                         goto free_old_hdr;
411                 }
412         }
413         memset(old_hdr, 0, SZ_SG_HEADER);
414         old_hdr->reply_len = (int) hp->timeout;
415         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
416         old_hdr->pack_id = hp->pack_id;
417         old_hdr->twelve_byte =
418             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
419         old_hdr->target_status = hp->masked_status;
420         old_hdr->host_status = hp->host_status;
421         old_hdr->driver_status = hp->driver_status;
422         if ((CHECK_CONDITION & hp->masked_status) ||
423             (DRIVER_SENSE & hp->driver_status))
424                 memcpy(old_hdr->sense_buffer, srp->sense_b,
425                        sizeof (old_hdr->sense_buffer));
426         switch (hp->host_status) {
427         /* This setup of 'result' is for backward compatibility and is best
428            ignored by the user who should use target, host + driver status */
429         case DID_OK:
430         case DID_PASSTHROUGH:
431         case DID_SOFT_ERROR:
432                 old_hdr->result = 0;
433                 break;
434         case DID_NO_CONNECT:
435         case DID_BUS_BUSY:
436         case DID_TIME_OUT:
437                 old_hdr->result = EBUSY;
438                 break;
439         case DID_BAD_TARGET:
440         case DID_ABORT:
441         case DID_PARITY:
442         case DID_RESET:
443         case DID_BAD_INTR:
444                 old_hdr->result = EIO;
445                 break;
446         case DID_ERROR:
447                 old_hdr->result = (srp->sense_b[0] == 0 && 
448                                   hp->masked_status == GOOD) ? 0 : EIO;
449                 break;
450         default:
451                 old_hdr->result = EIO;
452                 break;
453         }
454
455         /* Now copy the result back to the user buffer.  */
456         if (count >= SZ_SG_HEADER) {
457                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
458                         retval = -EFAULT;
459                         goto free_old_hdr;
460                 }
461                 buf += SZ_SG_HEADER;
462                 if (count > old_hdr->reply_len)
463                         count = old_hdr->reply_len;
464                 if (count > SZ_SG_HEADER) {
465                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
466                                 retval = -EFAULT;
467                                 goto free_old_hdr;
468                         }
469                 }
470         } else
471                 count = (old_hdr->result == 0) ? 0 : -EIO;
472         sg_finish_rem_req(srp);
473         retval = count;
474 free_old_hdr:
475         kfree(old_hdr);
476         return retval;
477 }
478
479 static ssize_t
480 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
481 {
482         sg_io_hdr_t *hp = &srp->header;
483         int err = 0;
484         int len;
485
486         if (count < SZ_SG_IO_HDR) {
487                 err = -EINVAL;
488                 goto err_out;
489         }
490         hp->sb_len_wr = 0;
491         if ((hp->mx_sb_len > 0) && hp->sbp) {
492                 if ((CHECK_CONDITION & hp->masked_status) ||
493                     (DRIVER_SENSE & hp->driver_status)) {
494                         int sb_len = SCSI_SENSE_BUFFERSIZE;
495                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
496                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
497                         len = (len > sb_len) ? sb_len : len;
498                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
499                                 err = -EFAULT;
500                                 goto err_out;
501                         }
502                         hp->sb_len_wr = len;
503                 }
504         }
505         if (hp->masked_status || hp->host_status || hp->driver_status)
506                 hp->info |= SG_INFO_CHECK;
507         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
508                 err = -EFAULT;
509                 goto err_out;
510         }
511         err = sg_read_xfer(srp);
512       err_out:
513         sg_finish_rem_req(srp);
514         return (0 == err) ? count : err;
515 }
516
517 static ssize_t
518 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
519 {
520         int mxsize, cmd_size, k;
521         int input_size, blocking;
522         unsigned char opcode;
523         Sg_device *sdp;
524         Sg_fd *sfp;
525         Sg_request *srp;
526         struct sg_header old_hdr;
527         sg_io_hdr_t *hp;
528         unsigned char cmnd[MAX_COMMAND_SIZE];
529
530         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
531                 return -ENXIO;
532         SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
533                                    sdp->disk->disk_name, (int) count));
534         if (sdp->detached)
535                 return -ENODEV;
536         if (!((filp->f_flags & O_NONBLOCK) ||
537               scsi_block_when_processing_errors(sdp->device)))
538                 return -ENXIO;
539
540         if (!access_ok(VERIFY_READ, buf, count))
541                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
542         if (count < SZ_SG_HEADER)
543                 return -EIO;
544         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
545                 return -EFAULT;
546         blocking = !(filp->f_flags & O_NONBLOCK);
547         if (old_hdr.reply_len < 0)
548                 return sg_new_write(sfp, buf, count, blocking, 0, NULL);
549         if (count < (SZ_SG_HEADER + 6))
550                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
551
552         if (!(srp = sg_add_request(sfp))) {
553                 SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
554                 return -EDOM;
555         }
556         buf += SZ_SG_HEADER;
557         __get_user(opcode, buf);
558         if (sfp->next_cmd_len > 0) {
559                 if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
560                         SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
561                         sfp->next_cmd_len = 0;
562                         sg_remove_request(sfp, srp);
563                         return -EIO;
564                 }
565                 cmd_size = sfp->next_cmd_len;
566                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
567         } else {
568                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
569                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
570                         cmd_size = 12;
571         }
572         SCSI_LOG_TIMEOUT(4, printk(
573                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
574 /* Determine buffer size.  */
575         input_size = count - cmd_size;
576         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
577         mxsize -= SZ_SG_HEADER;
578         input_size -= SZ_SG_HEADER;
579         if (input_size < 0) {
580                 sg_remove_request(sfp, srp);
581                 return -EIO;    /* User did not pass enough bytes for this command. */
582         }
583         hp = &srp->header;
584         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
585         hp->cmd_len = (unsigned char) cmd_size;
586         hp->iovec_count = 0;
587         hp->mx_sb_len = 0;
588         if (input_size > 0)
589                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
590                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
591         else
592                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
593         hp->dxfer_len = mxsize;
594         hp->dxferp = (char __user *)buf + cmd_size;
595         hp->sbp = NULL;
596         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
597         hp->flags = input_size; /* structure abuse ... */
598         hp->pack_id = old_hdr.pack_id;
599         hp->usr_ptr = NULL;
600         if (__copy_from_user(cmnd, buf, cmd_size))
601                 return -EFAULT;
602         /*
603          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
604          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
605          * is a non-zero input_size, so emit a warning.
606          */
607         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV)
608                 if (printk_ratelimit())
609                         printk(KERN_WARNING
610                                "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
611                                "guessing data in;\n" KERN_WARNING "   "
612                                "program %s not setting count and/or reply_len properly\n",
613                                old_hdr.reply_len - (int)SZ_SG_HEADER,
614                                input_size, (unsigned int) cmnd[0],
615                                current->comm);
616         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
617         return (k < 0) ? k : count;
618 }
619
620 static ssize_t
621 sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
622              int blocking, int read_only, Sg_request ** o_srp)
623 {
624         int k;
625         Sg_request *srp;
626         sg_io_hdr_t *hp;
627         unsigned char cmnd[MAX_COMMAND_SIZE];
628         int timeout;
629         unsigned long ul_timeout;
630
631         if (count < SZ_SG_IO_HDR)
632                 return -EINVAL;
633         if (!access_ok(VERIFY_READ, buf, count))
634                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
635
636         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
637         if (!(srp = sg_add_request(sfp))) {
638                 SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
639                 return -EDOM;
640         }
641         hp = &srp->header;
642         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
643                 sg_remove_request(sfp, srp);
644                 return -EFAULT;
645         }
646         if (hp->interface_id != 'S') {
647                 sg_remove_request(sfp, srp);
648                 return -ENOSYS;
649         }
650         if (hp->flags & SG_FLAG_MMAP_IO) {
651                 if (hp->dxfer_len > sfp->reserve.bufflen) {
652                         sg_remove_request(sfp, srp);
653                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
654                 }
655                 if (hp->flags & SG_FLAG_DIRECT_IO) {
656                         sg_remove_request(sfp, srp);
657                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
658                 }
659                 if (sg_res_in_use(sfp)) {
660                         sg_remove_request(sfp, srp);
661                         return -EBUSY;  /* reserve buffer already being used */
662                 }
663         }
664         ul_timeout = msecs_to_jiffies(srp->header.timeout);
665         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
666         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
667                 sg_remove_request(sfp, srp);
668                 return -EMSGSIZE;
669         }
670         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
671                 sg_remove_request(sfp, srp);
672                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
673         }
674         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
675                 sg_remove_request(sfp, srp);
676                 return -EFAULT;
677         }
678         if (read_only &&
679             (!sg_allow_access(cmnd[0], sfp->parentdp->device->type))) {
680                 sg_remove_request(sfp, srp);
681                 return -EPERM;
682         }
683         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
684         if (k < 0)
685                 return k;
686         if (o_srp)
687                 *o_srp = srp;
688         return count;
689 }
690
691 static int
692 sg_common_write(Sg_fd * sfp, Sg_request * srp,
693                 unsigned char *cmnd, int timeout, int blocking)
694 {
695         int k, data_dir;
696         Sg_device *sdp = sfp->parentdp;
697         sg_io_hdr_t *hp = &srp->header;
698
699         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
700         hp->status = 0;
701         hp->masked_status = 0;
702         hp->msg_status = 0;
703         hp->info = 0;
704         hp->host_status = 0;
705         hp->driver_status = 0;
706         hp->resid = 0;
707         SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
708                           (int) cmnd[0], (int) hp->cmd_len));
709
710         if ((k = sg_start_req(srp))) {
711                 SCSI_LOG_TIMEOUT(1, printk("sg_write: start_req err=%d\n", k));
712                 sg_finish_rem_req(srp);
713                 return k;       /* probably out of space --> ENOMEM */
714         }
715         if ((k = sg_write_xfer(srp))) {
716                 SCSI_LOG_TIMEOUT(1, printk("sg_write: write_xfer, bad address\n"));
717                 sg_finish_rem_req(srp);
718                 return k;
719         }
720         if (sdp->detached) {
721                 sg_finish_rem_req(srp);
722                 return -ENODEV;
723         }
724
725         switch (hp->dxfer_direction) {
726         case SG_DXFER_TO_FROM_DEV:
727         case SG_DXFER_FROM_DEV:
728                 data_dir = DMA_FROM_DEVICE;
729                 break;
730         case SG_DXFER_TO_DEV:
731                 data_dir = DMA_TO_DEVICE;
732                 break;
733         case SG_DXFER_UNKNOWN:
734                 data_dir = DMA_BIDIRECTIONAL;
735                 break;
736         default:
737                 data_dir = DMA_NONE;
738                 break;
739         }
740         hp->duration = jiffies_to_msecs(jiffies);
741 /* Now send everything of to mid-level. The next time we hear about this
742    packet is when sg_cmd_done() is called (i.e. a callback). */
743         if (scsi_execute_async(sdp->device, cmnd, hp->cmd_len, data_dir, srp->data.buffer,
744                                 hp->dxfer_len, srp->data.k_use_sg, timeout,
745                                 SG_DEFAULT_RETRIES, srp, sg_cmd_done,
746                                 GFP_ATOMIC)) {
747                 SCSI_LOG_TIMEOUT(1, printk("sg_write: scsi_execute_async failed\n"));
748                 /*
749                  * most likely out of mem, but could also be a bad map
750                  */
751                 return -ENOMEM;
752         } else
753                 return 0;
754 }
755
756 static int
757 sg_srp_done(Sg_request *srp, Sg_fd *sfp)
758 {
759         unsigned long iflags;
760         int done;
761
762         read_lock_irqsave(&sfp->rq_list_lock, iflags);
763         done = srp->done;
764         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
765         return done;
766 }
767
768 static int
769 sg_ioctl(struct inode *inode, struct file *filp,
770          unsigned int cmd_in, unsigned long arg)
771 {
772         void __user *p = (void __user *)arg;
773         int __user *ip = p;
774         int result, val, read_only;
775         Sg_device *sdp;
776         Sg_fd *sfp;
777         Sg_request *srp;
778         unsigned long iflags;
779
780         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
781                 return -ENXIO;
782         SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
783                                    sdp->disk->disk_name, (int) cmd_in));
784         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
785
786         switch (cmd_in) {
787         case SG_IO:
788                 {
789                         int blocking = 1;       /* ignore O_NONBLOCK flag */
790
791                         if (sdp->detached)
792                                 return -ENODEV;
793                         if (!scsi_block_when_processing_errors(sdp->device))
794                                 return -ENXIO;
795                         if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
796                                 return -EFAULT;
797                         result =
798                             sg_new_write(sfp, p, SZ_SG_IO_HDR,
799                                          blocking, read_only, &srp);
800                         if (result < 0)
801                                 return result;
802                         srp->sg_io_owned = 1;
803                         while (1) {
804                                 result = 0;     /* following macro to beat race condition */
805                                 __wait_event_interruptible(sfp->read_wait,
806                                         (sdp->detached || sfp->closed || sg_srp_done(srp, sfp)),
807                                                            result);
808                                 if (sdp->detached)
809                                         return -ENODEV;
810                                 if (sfp->closed)
811                                         return 0;       /* request packet dropped already */
812                                 if (0 == result)
813                                         break;
814                                 srp->orphan = 1;
815                                 return result;  /* -ERESTARTSYS because signal hit process */
816                         }
817                         write_lock_irqsave(&sfp->rq_list_lock, iflags);
818                         srp->done = 2;
819                         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
820                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
821                         return (result < 0) ? result : 0;
822                 }
823         case SG_SET_TIMEOUT:
824                 result = get_user(val, ip);
825                 if (result)
826                         return result;
827                 if (val < 0)
828                         return -EIO;
829                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
830                     val = MULDIV (INT_MAX, USER_HZ, HZ);
831                 sfp->timeout_user = val;
832                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
833
834                 return 0;
835         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
836                                 /* strange ..., for backward compatibility */
837                 return sfp->timeout_user;
838         case SG_SET_FORCE_LOW_DMA:
839                 result = get_user(val, ip);
840                 if (result)
841                         return result;
842                 if (val) {
843                         sfp->low_dma = 1;
844                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
845                                 val = (int) sfp->reserve.bufflen;
846                                 sg_remove_scat(&sfp->reserve);
847                                 sg_build_reserve(sfp, val);
848                         }
849                 } else {
850                         if (sdp->detached)
851                                 return -ENODEV;
852                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
853                 }
854                 return 0;
855         case SG_GET_LOW_DMA:
856                 return put_user((int) sfp->low_dma, ip);
857         case SG_GET_SCSI_ID:
858                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
859                         return -EFAULT;
860                 else {
861                         sg_scsi_id_t __user *sg_idp = p;
862
863                         if (sdp->detached)
864                                 return -ENODEV;
865                         __put_user((int) sdp->device->host->host_no,
866                                    &sg_idp->host_no);
867                         __put_user((int) sdp->device->channel,
868                                    &sg_idp->channel);
869                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
870                         __put_user((int) sdp->device->lun, &sg_idp->lun);
871                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
872                         __put_user((short) sdp->device->host->cmd_per_lun,
873                                    &sg_idp->h_cmd_per_lun);
874                         __put_user((short) sdp->device->queue_depth,
875                                    &sg_idp->d_queue_depth);
876                         __put_user(0, &sg_idp->unused[0]);
877                         __put_user(0, &sg_idp->unused[1]);
878                         return 0;
879                 }
880         case SG_SET_FORCE_PACK_ID:
881                 result = get_user(val, ip);
882                 if (result)
883                         return result;
884                 sfp->force_packid = val ? 1 : 0;
885                 return 0;
886         case SG_GET_PACK_ID:
887                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
888                         return -EFAULT;
889                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
890                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
891                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
892                                 read_unlock_irqrestore(&sfp->rq_list_lock,
893                                                        iflags);
894                                 __put_user(srp->header.pack_id, ip);
895                                 return 0;
896                         }
897                 }
898                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
899                 __put_user(-1, ip);
900                 return 0;
901         case SG_GET_NUM_WAITING:
902                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
903                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
904                         if ((1 == srp->done) && (!srp->sg_io_owned))
905                                 ++val;
906                 }
907                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
908                 return put_user(val, ip);
909         case SG_GET_SG_TABLESIZE:
910                 return put_user(sdp->sg_tablesize, ip);
911         case SG_SET_RESERVED_SIZE:
912                 result = get_user(val, ip);
913                 if (result)
914                         return result;
915                 if (val < 0)
916                         return -EINVAL;
917                 if (val != sfp->reserve.bufflen) {
918                         if (sg_res_in_use(sfp) || sfp->mmap_called)
919                                 return -EBUSY;
920                         sg_remove_scat(&sfp->reserve);
921                         sg_build_reserve(sfp, val);
922                 }
923                 return 0;
924         case SG_GET_RESERVED_SIZE:
925                 val = (int) sfp->reserve.bufflen;
926                 return put_user(val, ip);
927         case SG_SET_COMMAND_Q:
928                 result = get_user(val, ip);
929                 if (result)
930                         return result;
931                 sfp->cmd_q = val ? 1 : 0;
932                 return 0;
933         case SG_GET_COMMAND_Q:
934                 return put_user((int) sfp->cmd_q, ip);
935         case SG_SET_KEEP_ORPHAN:
936                 result = get_user(val, ip);
937                 if (result)
938                         return result;
939                 sfp->keep_orphan = val;
940                 return 0;
941         case SG_GET_KEEP_ORPHAN:
942                 return put_user((int) sfp->keep_orphan, ip);
943         case SG_NEXT_CMD_LEN:
944                 result = get_user(val, ip);
945                 if (result)
946                         return result;
947                 sfp->next_cmd_len = (val > 0) ? val : 0;
948                 return 0;
949         case SG_GET_VERSION_NUM:
950                 return put_user(sg_version_num, ip);
951         case SG_GET_ACCESS_COUNT:
952                 /* faked - we don't have a real access count anymore */
953                 val = (sdp->device ? 1 : 0);
954                 return put_user(val, ip);
955         case SG_GET_REQUEST_TABLE:
956                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
957                         return -EFAULT;
958                 else {
959                         sg_req_info_t *rinfo;
960                         unsigned int ms;
961
962                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
963                                                                 GFP_KERNEL);
964                         if (!rinfo)
965                                 return -ENOMEM;
966                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
967                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
968                              ++val, srp = srp ? srp->nextrp : srp) {
969                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
970                                 if (srp) {
971                                         rinfo[val].req_state = srp->done + 1;
972                                         rinfo[val].problem =
973                                             srp->header.masked_status & 
974                                             srp->header.host_status & 
975                                             srp->header.driver_status;
976                                         if (srp->done)
977                                                 rinfo[val].duration =
978                                                         srp->header.duration;
979                                         else {
980                                                 ms = jiffies_to_msecs(jiffies);
981                                                 rinfo[val].duration =
982                                                     (ms > srp->header.duration) ?
983                                                     (ms - srp->header.duration) : 0;
984                                         }
985                                         rinfo[val].orphan = srp->orphan;
986                                         rinfo[val].sg_io_owned =
987                                                         srp->sg_io_owned;
988                                         rinfo[val].pack_id =
989                                                         srp->header.pack_id;
990                                         rinfo[val].usr_ptr =
991                                                         srp->header.usr_ptr;
992                                 }
993                         }
994                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
995                         result = __copy_to_user(p, rinfo, 
996                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
997                         result = result ? -EFAULT : 0;
998                         kfree(rinfo);
999                         return result;
1000                 }
1001         case SG_EMULATED_HOST:
1002                 if (sdp->detached)
1003                         return -ENODEV;
1004                 return put_user(sdp->device->host->hostt->emulated, ip);
1005         case SG_SCSI_RESET:
1006                 if (sdp->detached)
1007                         return -ENODEV;
1008                 if (filp->f_flags & O_NONBLOCK) {
1009                         if (scsi_host_in_recovery(sdp->device->host))
1010                                 return -EBUSY;
1011                 } else if (!scsi_block_when_processing_errors(sdp->device))
1012                         return -EBUSY;
1013                 result = get_user(val, ip);
1014                 if (result)
1015                         return result;
1016                 if (SG_SCSI_RESET_NOTHING == val)
1017                         return 0;
1018                 switch (val) {
1019                 case SG_SCSI_RESET_DEVICE:
1020                         val = SCSI_TRY_RESET_DEVICE;
1021                         break;
1022                 case SG_SCSI_RESET_BUS:
1023                         val = SCSI_TRY_RESET_BUS;
1024                         break;
1025                 case SG_SCSI_RESET_HOST:
1026                         val = SCSI_TRY_RESET_HOST;
1027                         break;
1028                 default:
1029                         return -EINVAL;
1030                 }
1031                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1032                         return -EACCES;
1033                 return (scsi_reset_provider(sdp->device, val) ==
1034                         SUCCESS) ? 0 : -EIO;
1035         case SCSI_IOCTL_SEND_COMMAND:
1036                 if (sdp->detached)
1037                         return -ENODEV;
1038                 if (read_only) {
1039                         unsigned char opcode = WRITE_6;
1040                         Scsi_Ioctl_Command __user *siocp = p;
1041
1042                         if (copy_from_user(&opcode, siocp->data, 1))
1043                                 return -EFAULT;
1044                         if (!sg_allow_access(opcode, sdp->device->type))
1045                                 return -EPERM;
1046                 }
1047                 return sg_scsi_ioctl(filp, sdp->device->request_queue, NULL, p);
1048         case SG_SET_DEBUG:
1049                 result = get_user(val, ip);
1050                 if (result)
1051                         return result;
1052                 sdp->sgdebug = (char) val;
1053                 return 0;
1054         case SCSI_IOCTL_GET_IDLUN:
1055         case SCSI_IOCTL_GET_BUS_NUMBER:
1056         case SCSI_IOCTL_PROBE_HOST:
1057         case SG_GET_TRANSFORM:
1058                 if (sdp->detached)
1059                         return -ENODEV;
1060                 return scsi_ioctl(sdp->device, cmd_in, p);
1061         default:
1062                 if (read_only)
1063                         return -EPERM;  /* don't know so take safe approach */
1064                 return scsi_ioctl(sdp->device, cmd_in, p);
1065         }
1066 }
1067
1068 #ifdef CONFIG_COMPAT
1069 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1070 {
1071         Sg_device *sdp;
1072         Sg_fd *sfp;
1073         struct scsi_device *sdev;
1074
1075         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1076                 return -ENXIO;
1077
1078         sdev = sdp->device;
1079         if (sdev->host->hostt->compat_ioctl) { 
1080                 int ret;
1081
1082                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1083
1084                 return ret;
1085         }
1086         
1087         return -ENOIOCTLCMD;
1088 }
1089 #endif
1090
1091 static unsigned int
1092 sg_poll(struct file *filp, poll_table * wait)
1093 {
1094         unsigned int res = 0;
1095         Sg_device *sdp;
1096         Sg_fd *sfp;
1097         Sg_request *srp;
1098         int count = 0;
1099         unsigned long iflags;
1100
1101         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1102             || sfp->closed)
1103                 return POLLERR;
1104         poll_wait(filp, &sfp->read_wait, wait);
1105         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1106         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1107                 /* if any read waiting, flag it */
1108                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1109                         res = POLLIN | POLLRDNORM;
1110                 ++count;
1111         }
1112         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1113
1114         if (sdp->detached)
1115                 res |= POLLHUP;
1116         else if (!sfp->cmd_q) {
1117                 if (0 == count)
1118                         res |= POLLOUT | POLLWRNORM;
1119         } else if (count < SG_MAX_QUEUE)
1120                 res |= POLLOUT | POLLWRNORM;
1121         SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1122                                    sdp->disk->disk_name, (int) res));
1123         return res;
1124 }
1125
1126 static int
1127 sg_fasync(int fd, struct file *filp, int mode)
1128 {
1129         int retval;
1130         Sg_device *sdp;
1131         Sg_fd *sfp;
1132
1133         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1134                 return -ENXIO;
1135         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1136                                    sdp->disk->disk_name, mode));
1137
1138         retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
1139         return (retval < 0) ? retval : 0;
1140 }
1141
1142 static struct page *
1143 sg_vma_nopage(struct vm_area_struct *vma, unsigned long addr, int *type)
1144 {
1145         Sg_fd *sfp;
1146         struct page *page = NOPAGE_SIGBUS;
1147         unsigned long offset, len, sa;
1148         Sg_scatter_hold *rsv_schp;
1149         struct scatterlist *sg;
1150         int k;
1151
1152         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1153                 return page;
1154         rsv_schp = &sfp->reserve;
1155         offset = addr - vma->vm_start;
1156         if (offset >= rsv_schp->bufflen)
1157                 return page;
1158         SCSI_LOG_TIMEOUT(3, printk("sg_vma_nopage: offset=%lu, scatg=%d\n",
1159                                    offset, rsv_schp->k_use_sg));
1160         sg = rsv_schp->buffer;
1161         sa = vma->vm_start;
1162         for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1163              ++k, ++sg) {
1164                 len = vma->vm_end - sa;
1165                 len = (len < sg->length) ? len : sg->length;
1166                 if (offset < len) {
1167                         page = sg->page;
1168                         get_page(page); /* increment page count */
1169                         break;
1170                 }
1171                 sa += len;
1172                 offset -= len;
1173         }
1174
1175         if (type)
1176                 *type = VM_FAULT_MINOR;
1177         return page;
1178 }
1179
1180 static struct vm_operations_struct sg_mmap_vm_ops = {
1181         .nopage = sg_vma_nopage,
1182 };
1183
1184 static int
1185 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1186 {
1187         Sg_fd *sfp;
1188         unsigned long req_sz, len, sa;
1189         Sg_scatter_hold *rsv_schp;
1190         int k;
1191         struct scatterlist *sg;
1192
1193         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1194                 return -ENXIO;
1195         req_sz = vma->vm_end - vma->vm_start;
1196         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1197                                    (void *) vma->vm_start, (int) req_sz));
1198         if (vma->vm_pgoff)
1199                 return -EINVAL; /* want no offset */
1200         rsv_schp = &sfp->reserve;
1201         if (req_sz > rsv_schp->bufflen)
1202                 return -ENOMEM; /* cannot map more than reserved buffer */
1203
1204         sa = vma->vm_start;
1205         sg = rsv_schp->buffer;
1206         for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1207              ++k, ++sg) {
1208                 len = vma->vm_end - sa;
1209                 len = (len < sg->length) ? len : sg->length;
1210                 sa += len;
1211         }
1212
1213         sfp->mmap_called = 1;
1214         vma->vm_flags |= VM_RESERVED;
1215         vma->vm_private_data = sfp;
1216         vma->vm_ops = &sg_mmap_vm_ops;
1217         return 0;
1218 }
1219
1220 /* This function is a "bottom half" handler that is called by the
1221  * mid level when a command is completed (or has failed). */
1222 static void
1223 sg_cmd_done(void *data, char *sense, int result, int resid)
1224 {
1225         Sg_request *srp = data;
1226         Sg_device *sdp = NULL;
1227         Sg_fd *sfp;
1228         unsigned long iflags;
1229         unsigned int ms;
1230
1231         if (NULL == srp) {
1232                 printk(KERN_ERR "sg_cmd_done: NULL request\n");
1233                 return;
1234         }
1235         sfp = srp->parentfp;
1236         if (sfp)
1237                 sdp = sfp->parentdp;
1238         if ((NULL == sdp) || sdp->detached) {
1239                 printk(KERN_INFO "sg_cmd_done: device detached\n");
1240                 return;
1241         }
1242
1243
1244         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1245                 sdp->disk->disk_name, srp->header.pack_id, result));
1246         srp->header.resid = resid;
1247         ms = jiffies_to_msecs(jiffies);
1248         srp->header.duration = (ms > srp->header.duration) ?
1249                                 (ms - srp->header.duration) : 0;
1250         if (0 != result) {
1251                 struct scsi_sense_hdr sshdr;
1252
1253                 memcpy(srp->sense_b, sense, sizeof (srp->sense_b));
1254                 srp->header.status = 0xff & result;
1255                 srp->header.masked_status = status_byte(result);
1256                 srp->header.msg_status = msg_byte(result);
1257                 srp->header.host_status = host_byte(result);
1258                 srp->header.driver_status = driver_byte(result);
1259                 if ((sdp->sgdebug > 0) &&
1260                     ((CHECK_CONDITION == srp->header.masked_status) ||
1261                      (COMMAND_TERMINATED == srp->header.masked_status)))
1262                         __scsi_print_sense("sg_cmd_done", sense,
1263                                            SCSI_SENSE_BUFFERSIZE);
1264
1265                 /* Following if statement is a patch supplied by Eric Youngdale */
1266                 if (driver_byte(result) != 0
1267                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1268                     && !scsi_sense_is_deferred(&sshdr)
1269                     && sshdr.sense_key == UNIT_ATTENTION
1270                     && sdp->device->removable) {
1271                         /* Detected possible disc change. Set the bit - this */
1272                         /* may be used if there are filesystems using this device */
1273                         sdp->device->changed = 1;
1274                 }
1275         }
1276         /* Rely on write phase to clean out srp status values, so no "else" */
1277
1278         if (sfp->closed) {      /* whoops this fd already released, cleanup */
1279                 SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
1280                 sg_finish_rem_req(srp);
1281                 srp = NULL;
1282                 if (NULL == sfp->headrp) {
1283                         SCSI_LOG_TIMEOUT(1, printk("sg...bh: already closed, final cleanup\n"));
1284                         if (0 == sg_remove_sfp(sdp, sfp)) {     /* device still present */
1285                                 scsi_device_put(sdp->device);
1286                         }
1287                         sfp = NULL;
1288                 }
1289         } else if (srp && srp->orphan) {
1290                 if (sfp->keep_orphan)
1291                         srp->sg_io_owned = 0;
1292                 else {
1293                         sg_finish_rem_req(srp);
1294                         srp = NULL;
1295                 }
1296         }
1297         if (sfp && srp) {
1298                 /* Now wake up any sg_read() that is waiting for this packet. */
1299                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1300                 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1301                 srp->done = 1;
1302                 wake_up_interruptible(&sfp->read_wait);
1303                 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1304         }
1305 }
1306
1307 static struct file_operations sg_fops = {
1308         .owner = THIS_MODULE,
1309         .read = sg_read,
1310         .write = sg_write,
1311         .poll = sg_poll,
1312         .ioctl = sg_ioctl,
1313 #ifdef CONFIG_COMPAT
1314         .compat_ioctl = sg_compat_ioctl,
1315 #endif
1316         .open = sg_open,
1317         .mmap = sg_mmap,
1318         .release = sg_release,
1319         .fasync = sg_fasync,
1320 };
1321
1322 static struct class *sg_sysfs_class;
1323
1324 static int sg_sysfs_valid = 0;
1325
1326 static int sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1327 {
1328         struct request_queue *q = scsidp->request_queue;
1329         Sg_device *sdp;
1330         unsigned long iflags;
1331         void *old_sg_dev_arr = NULL;
1332         int k, error;
1333
1334         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1335         if (!sdp) {
1336                 printk(KERN_WARNING "kmalloc Sg_device failure\n");
1337                 return -ENOMEM;
1338         }
1339
1340         write_lock_irqsave(&sg_dev_arr_lock, iflags);
1341         if (unlikely(sg_nr_dev >= sg_dev_max)) {        /* try to resize */
1342                 Sg_device **tmp_da;
1343                 int tmp_dev_max = sg_nr_dev + SG_DEV_ARR_LUMP;
1344                 write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1345
1346                 tmp_da = kzalloc(tmp_dev_max * sizeof(Sg_device *), GFP_KERNEL);
1347                 if (unlikely(!tmp_da))
1348                         goto expand_failed;
1349
1350                 write_lock_irqsave(&sg_dev_arr_lock, iflags);
1351                 memcpy(tmp_da, sg_dev_arr, sg_dev_max * sizeof(Sg_device *));
1352                 old_sg_dev_arr = sg_dev_arr;
1353                 sg_dev_arr = tmp_da;
1354                 sg_dev_max = tmp_dev_max;
1355         }
1356
1357         for (k = 0; k < sg_dev_max; k++)
1358                 if (!sg_dev_arr[k])
1359                         break;
1360         if (unlikely(k >= SG_MAX_DEVS))
1361                 goto overflow;
1362
1363         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1364         sprintf(disk->disk_name, "sg%d", k);
1365         disk->first_minor = k;
1366         sdp->disk = disk;
1367         sdp->device = scsidp;
1368         init_waitqueue_head(&sdp->o_excl_wait);
1369         sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments);
1370
1371         sg_nr_dev++;
1372         sg_dev_arr[k] = sdp;
1373         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1374         error = k;
1375
1376  out:
1377         if (error < 0)
1378                 kfree(sdp);
1379         kfree(old_sg_dev_arr);
1380         return error;
1381
1382  expand_failed:
1383         printk(KERN_WARNING "sg_alloc: device array cannot be resized\n");
1384         error = -ENOMEM;
1385         goto out;
1386
1387  overflow:
1388         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1389         sdev_printk(KERN_WARNING, scsidp,
1390                     "Unable to attach sg device type=%d, minor "
1391                     "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1392         error = -ENODEV;
1393         goto out;
1394 }
1395
1396 static int
1397 sg_add(struct class_device *cl_dev, struct class_interface *cl_intf)
1398 {
1399         struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1400         struct gendisk *disk;
1401         Sg_device *sdp = NULL;
1402         struct cdev * cdev = NULL;
1403         int error, k;
1404
1405         disk = alloc_disk(1);
1406         if (!disk) {
1407                 printk(KERN_WARNING "alloc_disk failed\n");
1408                 return -ENOMEM;
1409         }
1410         disk->major = SCSI_GENERIC_MAJOR;
1411
1412         error = -ENOMEM;
1413         cdev = cdev_alloc();
1414         if (!cdev) {
1415                 printk(KERN_WARNING "cdev_alloc failed\n");
1416                 goto out;
1417         }
1418         cdev->owner = THIS_MODULE;
1419         cdev->ops = &sg_fops;
1420
1421         error = sg_alloc(disk, scsidp);
1422         if (error < 0) {
1423                 printk(KERN_WARNING "sg_alloc failed\n");
1424                 goto out;
1425         }
1426         k = error;
1427         sdp = sg_dev_arr[k];
1428
1429         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, k), 1);
1430         if (error)
1431                 goto out;
1432
1433         sdp->cdev = cdev;
1434         if (sg_sysfs_valid) {
1435                 struct class_device * sg_class_member;
1436
1437                 sg_class_member = class_device_create(sg_sysfs_class, NULL,
1438                                 MKDEV(SCSI_GENERIC_MAJOR, k), 
1439                                 cl_dev->dev, "%s", 
1440                                 disk->disk_name);
1441                 if (IS_ERR(sg_class_member))
1442                         printk(KERN_WARNING "sg_add: "
1443                                 "class_device_create failed\n");
1444                 class_set_devdata(sg_class_member, sdp);
1445                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj, 
1446                                           &sg_class_member->kobj, "generic");
1447                 if (error)
1448                         printk(KERN_ERR "sg_add: unable to make symlink "
1449                                         "'generic' back to sg%d\n", k);
1450         } else
1451                 printk(KERN_WARNING "sg_add: sg_sys INvalid\n");
1452
1453         sdev_printk(KERN_NOTICE, scsidp,
1454                     "Attached scsi generic sg%d type %d\n", k,scsidp->type);
1455
1456         return 0;
1457
1458 out:
1459         put_disk(disk);
1460         if (cdev)
1461                 cdev_del(cdev);
1462         return error;
1463 }
1464
1465 static void
1466 sg_remove(struct class_device *cl_dev, struct class_interface *cl_intf)
1467 {
1468         struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1469         Sg_device *sdp = NULL;
1470         unsigned long iflags;
1471         Sg_fd *sfp;
1472         Sg_fd *tsfp;
1473         Sg_request *srp;
1474         Sg_request *tsrp;
1475         int k, delay;
1476
1477         if (NULL == sg_dev_arr)
1478                 return;
1479         delay = 0;
1480         write_lock_irqsave(&sg_dev_arr_lock, iflags);
1481         for (k = 0; k < sg_dev_max; k++) {
1482                 sdp = sg_dev_arr[k];
1483                 if ((NULL == sdp) || (sdp->device != scsidp))
1484                         continue;       /* dirty but lowers nesting */
1485                 if (sdp->headfp) {
1486                         sdp->detached = 1;
1487                         for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1488                                 tsfp = sfp->nextfp;
1489                                 for (srp = sfp->headrp; srp; srp = tsrp) {
1490                                         tsrp = srp->nextrp;
1491                                         if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
1492                                                 sg_finish_rem_req(srp);
1493                                 }
1494                                 if (sfp->closed) {
1495                                         scsi_device_put(sdp->device);
1496                                         __sg_remove_sfp(sdp, sfp);
1497                                 } else {
1498                                         delay = 1;
1499                                         wake_up_interruptible(&sfp->read_wait);
1500                                         kill_fasync(&sfp->async_qp, SIGPOLL,
1501                                                     POLL_HUP);
1502                                 }
1503                         }
1504                         SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d, dirty\n", k));
1505                         if (NULL == sdp->headfp) {
1506                                 sg_dev_arr[k] = NULL;
1507                         }
1508                 } else {        /* nothing active, simple case */
1509                         SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d\n", k));
1510                         sg_dev_arr[k] = NULL;
1511                 }
1512                 sg_nr_dev--;
1513                 break;
1514         }
1515         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1516
1517         if (sdp) {
1518                 sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1519                 class_device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, k));
1520                 cdev_del(sdp->cdev);
1521                 sdp->cdev = NULL;
1522                 put_disk(sdp->disk);
1523                 sdp->disk = NULL;
1524                 if (NULL == sdp->headfp)
1525                         kfree((char *) sdp);
1526         }
1527
1528         if (delay)
1529                 msleep(10);     /* dirty detach so delay device destruction */
1530 }
1531
1532 /* Set 'perm' (4th argument) to 0 to disable module_param's definition
1533  * of sysfs parameters (which module_param doesn't yet support).
1534  * Sysfs parameters defined explicitly below.
1535  */
1536 module_param_named(def_reserved_size, def_reserved_size, int, S_IRUGO);
1537 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1538
1539 MODULE_AUTHOR("Douglas Gilbert");
1540 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1541 MODULE_LICENSE("GPL");
1542 MODULE_VERSION(SG_VERSION_STR);
1543 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1544
1545 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1546 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1547
1548 static int __init
1549 init_sg(void)
1550 {
1551         int rc;
1552
1553         if (def_reserved_size >= 0)
1554                 sg_big_buff = def_reserved_size;
1555
1556         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), 
1557                                     SG_MAX_DEVS, "sg");
1558         if (rc)
1559                 return rc;
1560         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1561         if ( IS_ERR(sg_sysfs_class) ) {
1562                 rc = PTR_ERR(sg_sysfs_class);
1563                 goto err_out;
1564         }
1565         sg_sysfs_valid = 1;
1566         rc = scsi_register_interface(&sg_interface);
1567         if (0 == rc) {
1568 #ifdef CONFIG_SCSI_PROC_FS
1569                 sg_proc_init();
1570 #endif                          /* CONFIG_SCSI_PROC_FS */
1571                 return 0;
1572         }
1573         class_destroy(sg_sysfs_class);
1574 err_out:
1575         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1576         return rc;
1577 }
1578
1579 static void __exit
1580 exit_sg(void)
1581 {
1582 #ifdef CONFIG_SCSI_PROC_FS
1583         sg_proc_cleanup();
1584 #endif                          /* CONFIG_SCSI_PROC_FS */
1585         scsi_unregister_interface(&sg_interface);
1586         class_destroy(sg_sysfs_class);
1587         sg_sysfs_valid = 0;
1588         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1589                                  SG_MAX_DEVS);
1590         kfree((char *)sg_dev_arr);
1591         sg_dev_arr = NULL;
1592         sg_dev_max = 0;
1593 }
1594
1595 static int
1596 sg_start_req(Sg_request * srp)
1597 {
1598         int res;
1599         Sg_fd *sfp = srp->parentfp;
1600         sg_io_hdr_t *hp = &srp->header;
1601         int dxfer_len = (int) hp->dxfer_len;
1602         int dxfer_dir = hp->dxfer_direction;
1603         Sg_scatter_hold *req_schp = &srp->data;
1604         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1605
1606         SCSI_LOG_TIMEOUT(4, printk("sg_start_req: dxfer_len=%d\n", dxfer_len));
1607         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1608                 return 0;
1609         if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) &&
1610             (dxfer_dir != SG_DXFER_UNKNOWN) && (0 == hp->iovec_count) &&
1611             (!sfp->parentdp->device->host->unchecked_isa_dma)) {
1612                 res = sg_build_direct(srp, sfp, dxfer_len);
1613                 if (res <= 0)   /* -ve -> error, 0 -> done, 1 -> try indirect */
1614                         return res;
1615         }
1616         if ((!sg_res_in_use(sfp)) && (dxfer_len <= rsv_schp->bufflen))
1617                 sg_link_reserve(sfp, srp, dxfer_len);
1618         else {
1619                 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1620                 if (res) {
1621                         sg_remove_scat(req_schp);
1622                         return res;
1623                 }
1624         }
1625         return 0;
1626 }
1627
1628 static void
1629 sg_finish_rem_req(Sg_request * srp)
1630 {
1631         Sg_fd *sfp = srp->parentfp;
1632         Sg_scatter_hold *req_schp = &srp->data;
1633
1634         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1635         if (srp->res_used)
1636                 sg_unlink_reserve(sfp, srp);
1637         else
1638                 sg_remove_scat(req_schp);
1639         sg_remove_request(sfp, srp);
1640 }
1641
1642 static int
1643 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1644 {
1645         int sg_bufflen = tablesize * sizeof(struct scatterlist);
1646         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1647
1648         /*
1649          * TODO: test without low_dma, we should not need it since
1650          * the block layer will bounce the buffer for us
1651          *
1652          * XXX(hch): we shouldn't need GFP_DMA for the actual S/G list.
1653          */
1654         if (sfp->low_dma)
1655                  gfp_flags |= GFP_DMA;
1656         schp->buffer = kzalloc(sg_bufflen, gfp_flags);
1657         if (!schp->buffer)
1658                 return -ENOMEM;
1659         schp->sglist_len = sg_bufflen;
1660         return tablesize;       /* number of scat_gath elements allocated */
1661 }
1662
1663 #ifdef SG_ALLOW_DIO_CODE
1664 /* vvvvvvvv  following code borrowed from st driver's direct IO vvvvvvvvv */
1665         /* TODO: hopefully we can use the generic block layer code */
1666
1667 /* Pin down user pages and put them into a scatter gather list. Returns <= 0 if
1668    - mapping of all pages not successful
1669    (i.e., either completely successful or fails)
1670 */
1671 static int 
1672 st_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages, 
1673                   unsigned long uaddr, size_t count, int rw)
1674 {
1675         unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
1676         unsigned long start = uaddr >> PAGE_SHIFT;
1677         const int nr_pages = end - start;
1678         int res, i, j;
1679         struct page **pages;
1680
1681         /* User attempted Overflow! */
1682         if ((uaddr + count) < uaddr)
1683                 return -EINVAL;
1684
1685         /* Too big */
1686         if (nr_pages > max_pages)
1687                 return -ENOMEM;
1688
1689         /* Hmm? */
1690         if (count == 0)
1691                 return 0;
1692
1693         if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_ATOMIC)) == NULL)
1694                 return -ENOMEM;
1695
1696         /* Try to fault in all of the necessary pages */
1697         down_read(&current->mm->mmap_sem);
1698         /* rw==READ means read from drive, write into memory area */
1699         res = get_user_pages(
1700                 current,
1701                 current->mm,
1702                 uaddr,
1703                 nr_pages,
1704                 rw == READ,
1705                 0, /* don't force */
1706                 pages,
1707                 NULL);
1708         up_read(&current->mm->mmap_sem);
1709
1710         /* Errors and no page mapped should return here */
1711         if (res < nr_pages)
1712                 goto out_unmap;
1713
1714         for (i=0; i < nr_pages; i++) {
1715                 /* FIXME: flush superflous for rw==READ,
1716                  * probably wrong function for rw==WRITE
1717                  */
1718                 flush_dcache_page(pages[i]);
1719                 /* ?? Is locking needed? I don't think so */
1720                 /* if (TestSetPageLocked(pages[i]))
1721                    goto out_unlock; */
1722         }
1723
1724         sgl[0].page = pages[0];
1725         sgl[0].offset = uaddr & ~PAGE_MASK;
1726         if (nr_pages > 1) {
1727                 sgl[0].length = PAGE_SIZE - sgl[0].offset;
1728                 count -= sgl[0].length;
1729                 for (i=1; i < nr_pages ; i++) {
1730                         sgl[i].page = pages[i]; 
1731                         sgl[i].length = count < PAGE_SIZE ? count : PAGE_SIZE;
1732                         count -= PAGE_SIZE;
1733                 }
1734         }
1735         else {
1736                 sgl[0].length = count;
1737         }
1738
1739         kfree(pages);
1740         return nr_pages;
1741
1742  out_unmap:
1743         if (res > 0) {
1744                 for (j=0; j < res; j++)
1745                         page_cache_release(pages[j]);
1746                 res = 0;
1747         }
1748         kfree(pages);
1749         return res;
1750 }
1751
1752
1753 /* And unmap them... */
1754 static int 
1755 st_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_pages,
1756                     int dirtied)
1757 {
1758         int i;
1759
1760         for (i=0; i < nr_pages; i++) {
1761                 struct page *page = sgl[i].page;
1762
1763                 if (dirtied)
1764                         SetPageDirty(page);
1765                 /* unlock_page(page); */
1766                 /* FIXME: cache flush missing for rw==READ
1767                  * FIXME: call the correct reference counting function
1768                  */
1769                 page_cache_release(page);
1770         }
1771
1772         return 0;
1773 }
1774
1775 /* ^^^^^^^^  above code borrowed from st driver's direct IO ^^^^^^^^^ */
1776 #endif
1777
1778
1779 /* Returns: -ve -> error, 0 -> done, 1 -> try indirect */
1780 static int
1781 sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len)
1782 {
1783 #ifdef SG_ALLOW_DIO_CODE
1784         sg_io_hdr_t *hp = &srp->header;
1785         Sg_scatter_hold *schp = &srp->data;
1786         int sg_tablesize = sfp->parentdp->sg_tablesize;
1787         int mx_sc_elems, res;
1788         struct scsi_device *sdev = sfp->parentdp->device;
1789
1790         if (((unsigned long)hp->dxferp &
1791                         queue_dma_alignment(sdev->request_queue)) != 0)
1792                 return 1;
1793
1794         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1795         if (mx_sc_elems <= 0) {
1796                 return 1;
1797         }
1798         res = st_map_user_pages(schp->buffer, mx_sc_elems,
1799                                 (unsigned long)hp->dxferp, dxfer_len, 
1800                                 (SG_DXFER_TO_DEV == hp->dxfer_direction) ? 1 : 0);
1801         if (res <= 0)
1802                 return 1;
1803         schp->k_use_sg = res;
1804         schp->dio_in_use = 1;
1805         hp->info |= SG_INFO_DIRECT_IO;
1806         return 0;
1807 #else
1808         return 1;
1809 #endif
1810 }
1811
1812 static int
1813 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1814 {
1815         struct scatterlist *sg;
1816         int ret_sz = 0, k, rem_sz, num, mx_sc_elems;
1817         int sg_tablesize = sfp->parentdp->sg_tablesize;
1818         int blk_size = buff_size;
1819         struct page *p = NULL;
1820
1821         if ((blk_size < 0) || (!sfp))
1822                 return -EFAULT;
1823         if (0 == blk_size)
1824                 ++blk_size;     /* don't know why */
1825 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1826         blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
1827         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1828                                    buff_size, blk_size));
1829
1830         /* N.B. ret_sz carried into this block ... */
1831         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1832         if (mx_sc_elems < 0)
1833                 return mx_sc_elems;     /* most likely -ENOMEM */
1834
1835         for (k = 0, sg = schp->buffer, rem_sz = blk_size;
1836              (rem_sz > 0) && (k < mx_sc_elems);
1837              ++k, rem_sz -= ret_sz, ++sg) {
1838                 
1839                 num = (rem_sz > SG_SCATTER_SZ) ? SG_SCATTER_SZ : rem_sz;
1840                 p = sg_page_malloc(num, sfp->low_dma, &ret_sz);
1841                 if (!p)
1842                         return -ENOMEM;
1843
1844                 sg->page = p;
1845                 sg->length = ret_sz;
1846
1847                 SCSI_LOG_TIMEOUT(5, printk("sg_build_build: k=%d, a=0x%p, len=%d\n",
1848                                   k, p, ret_sz));
1849         }               /* end of for loop */
1850
1851         schp->k_use_sg = k;
1852         SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, rem_sz=%d\n", k, rem_sz));
1853
1854         schp->bufflen = blk_size;
1855         if (rem_sz > 0) /* must have failed */
1856                 return -ENOMEM;
1857
1858         return 0;
1859 }
1860
1861 static int
1862 sg_write_xfer(Sg_request * srp)
1863 {
1864         sg_io_hdr_t *hp = &srp->header;
1865         Sg_scatter_hold *schp = &srp->data;
1866         struct scatterlist *sg = schp->buffer;
1867         int num_xfer = 0;
1868         int j, k, onum, usglen, ksglen, res;
1869         int iovec_count = (int) hp->iovec_count;
1870         int dxfer_dir = hp->dxfer_direction;
1871         unsigned char *p;
1872         unsigned char __user *up;
1873         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
1874
1875         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_TO_DEV == dxfer_dir) ||
1876             (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
1877                 num_xfer = (int) (new_interface ? hp->dxfer_len : hp->flags);
1878                 if (schp->bufflen < num_xfer)
1879                         num_xfer = schp->bufflen;
1880         }
1881         if ((num_xfer <= 0) || (schp->dio_in_use) ||
1882             (new_interface
1883              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
1884                 return 0;
1885
1886         SCSI_LOG_TIMEOUT(4, printk("sg_write_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
1887                           num_xfer, iovec_count, schp->k_use_sg));
1888         if (iovec_count) {
1889                 onum = iovec_count;
1890                 if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
1891                         return -EFAULT;
1892         } else
1893                 onum = 1;
1894
1895         ksglen = sg->length;
1896         p = page_address(sg->page);
1897         for (j = 0, k = 0; j < onum; ++j) {
1898                 res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
1899                 if (res)
1900                         return res;
1901
1902                 for (; p; ++sg, ksglen = sg->length,
1903                      p = page_address(sg->page)) {
1904                         if (usglen <= 0)
1905                                 break;
1906                         if (ksglen > usglen) {
1907                                 if (usglen >= num_xfer) {
1908                                         if (__copy_from_user(p, up, num_xfer))
1909                                                 return -EFAULT;
1910                                         return 0;
1911                                 }
1912                                 if (__copy_from_user(p, up, usglen))
1913                                         return -EFAULT;
1914                                 p += usglen;
1915                                 ksglen -= usglen;
1916                                 break;
1917                         } else {
1918                                 if (ksglen >= num_xfer) {
1919                                         if (__copy_from_user(p, up, num_xfer))
1920                                                 return -EFAULT;
1921                                         return 0;
1922                                 }
1923                                 if (__copy_from_user(p, up, ksglen))
1924                                         return -EFAULT;
1925                                 up += ksglen;
1926                                 usglen -= ksglen;
1927                         }
1928                         ++k;
1929                         if (k >= schp->k_use_sg)
1930                                 return 0;
1931                 }
1932         }
1933
1934         return 0;
1935 }
1936
1937 static int
1938 sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
1939            int wr_xf, int *countp, unsigned char __user **up)
1940 {
1941         int num_xfer = (int) hp->dxfer_len;
1942         unsigned char __user *p = hp->dxferp;
1943         int count;
1944
1945         if (0 == sg_num) {
1946                 if (wr_xf && ('\0' == hp->interface_id))
1947                         count = (int) hp->flags;        /* holds "old" input_size */
1948                 else
1949                         count = num_xfer;
1950         } else {
1951                 sg_iovec_t iovec;
1952                 if (__copy_from_user(&iovec, p + ind*SZ_SG_IOVEC, SZ_SG_IOVEC))
1953                         return -EFAULT;
1954                 p = iovec.iov_base;
1955                 count = (int) iovec.iov_len;
1956         }
1957         if (!access_ok(wr_xf ? VERIFY_READ : VERIFY_WRITE, p, count))
1958                 return -EFAULT;
1959         if (up)
1960                 *up = p;
1961         if (countp)
1962                 *countp = count;
1963         return 0;
1964 }
1965
1966 static void
1967 sg_remove_scat(Sg_scatter_hold * schp)
1968 {
1969         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1970         if (schp->buffer && (schp->sglist_len > 0)) {
1971                 struct scatterlist *sg = schp->buffer;
1972
1973                 if (schp->dio_in_use) {
1974 #ifdef SG_ALLOW_DIO_CODE
1975                         st_unmap_user_pages(sg, schp->k_use_sg, TRUE);
1976 #endif
1977                 } else {
1978                         int k;
1979
1980                         for (k = 0; (k < schp->k_use_sg) && sg->page;
1981                              ++k, ++sg) {
1982                                 SCSI_LOG_TIMEOUT(5, printk(
1983                                     "sg_remove_scat: k=%d, a=0x%p, len=%d\n",
1984                                     k, sg->page, sg->length));
1985                                 sg_page_free(sg->page, sg->length);
1986                         }
1987                 }
1988                 kfree(schp->buffer);
1989         }
1990         memset(schp, 0, sizeof (*schp));
1991 }
1992
1993 static int
1994 sg_read_xfer(Sg_request * srp)
1995 {
1996         sg_io_hdr_t *hp = &srp->header;
1997         Sg_scatter_hold *schp = &srp->data;
1998         struct scatterlist *sg = schp->buffer;
1999         int num_xfer = 0;
2000         int j, k, onum, usglen, ksglen, res;
2001         int iovec_count = (int) hp->iovec_count;
2002         int dxfer_dir = hp->dxfer_direction;
2003         unsigned char *p;
2004         unsigned char __user *up;
2005         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
2006
2007         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_FROM_DEV == dxfer_dir)
2008             || (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
2009                 num_xfer = hp->dxfer_len;
2010                 if (schp->bufflen < num_xfer)
2011                         num_xfer = schp->bufflen;
2012         }
2013         if ((num_xfer <= 0) || (schp->dio_in_use) ||
2014             (new_interface
2015              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
2016                 return 0;
2017
2018         SCSI_LOG_TIMEOUT(4, printk("sg_read_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
2019                           num_xfer, iovec_count, schp->k_use_sg));
2020         if (iovec_count) {
2021                 onum = iovec_count;
2022                 if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
2023                         return -EFAULT;
2024         } else
2025                 onum = 1;
2026
2027         p = page_address(sg->page);
2028         ksglen = sg->length;
2029         for (j = 0, k = 0; j < onum; ++j) {
2030                 res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
2031                 if (res)
2032                         return res;
2033
2034                 for (; p; ++sg, ksglen = sg->length,
2035                      p = page_address(sg->page)) {
2036                         if (usglen <= 0)
2037                                 break;
2038                         if (ksglen > usglen) {
2039                                 if (usglen >= num_xfer) {
2040                                         if (__copy_to_user(up, p, num_xfer))
2041                                                 return -EFAULT;
2042                                         return 0;
2043                                 }
2044                                 if (__copy_to_user(up, p, usglen))
2045                                         return -EFAULT;
2046                                 p += usglen;
2047                                 ksglen -= usglen;
2048                                 break;
2049                         } else {
2050                                 if (ksglen >= num_xfer) {
2051                                         if (__copy_to_user(up, p, num_xfer))
2052                                                 return -EFAULT;
2053                                         return 0;
2054                                 }
2055                                 if (__copy_to_user(up, p, ksglen))
2056                                         return -EFAULT;
2057                                 up += ksglen;
2058                                 usglen -= ksglen;
2059                         }
2060                         ++k;
2061                         if (k >= schp->k_use_sg)
2062                                 return 0;
2063                 }
2064         }
2065
2066         return 0;
2067 }
2068
2069 static int
2070 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
2071 {
2072         Sg_scatter_hold *schp = &srp->data;
2073         struct scatterlist *sg = schp->buffer;
2074         int k, num;
2075
2076         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
2077                                    num_read_xfer));
2078         if ((!outp) || (num_read_xfer <= 0))
2079                 return 0;
2080
2081         for (k = 0; (k < schp->k_use_sg) && sg->page; ++k, ++sg) {
2082                 num = sg->length;
2083                 if (num > num_read_xfer) {
2084                         if (__copy_to_user(outp, page_address(sg->page),
2085                                            num_read_xfer))
2086                                 return -EFAULT;
2087                         break;
2088                 } else {
2089                         if (__copy_to_user(outp, page_address(sg->page),
2090                                            num))
2091                                 return -EFAULT;
2092                         num_read_xfer -= num;
2093                         if (num_read_xfer <= 0)
2094                                 break;
2095                         outp += num;
2096                 }
2097         }
2098
2099         return 0;
2100 }
2101
2102 static void
2103 sg_build_reserve(Sg_fd * sfp, int req_size)
2104 {
2105         Sg_scatter_hold *schp = &sfp->reserve;
2106
2107         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
2108         do {
2109                 if (req_size < PAGE_SIZE)
2110                         req_size = PAGE_SIZE;
2111                 if (0 == sg_build_indirect(schp, sfp, req_size))
2112                         return;
2113                 else
2114                         sg_remove_scat(schp);
2115                 req_size >>= 1; /* divide by 2 */
2116         } while (req_size > (PAGE_SIZE / 2));
2117 }
2118
2119 static void
2120 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2121 {
2122         Sg_scatter_hold *req_schp = &srp->data;
2123         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2124         struct scatterlist *sg = rsv_schp->buffer;
2125         int k, num, rem;
2126
2127         srp->res_used = 1;
2128         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
2129         rem = size;
2130
2131         for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sg) {
2132                 num = sg->length;
2133                 if (rem <= num) {
2134                         sfp->save_scat_len = num;
2135                         sg->length = rem;
2136                         req_schp->k_use_sg = k + 1;
2137                         req_schp->sglist_len = rsv_schp->sglist_len;
2138                         req_schp->buffer = rsv_schp->buffer;
2139
2140                         req_schp->bufflen = size;
2141                         req_schp->b_malloc_len = rsv_schp->b_malloc_len;
2142                         break;
2143                 } else
2144                         rem -= num;
2145         }
2146
2147         if (k >= rsv_schp->k_use_sg)
2148                 SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
2149 }
2150
2151 static void
2152 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2153 {
2154         Sg_scatter_hold *req_schp = &srp->data;
2155         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2156
2157         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
2158                                    (int) req_schp->k_use_sg));
2159         if ((rsv_schp->k_use_sg > 0) && (req_schp->k_use_sg > 0)) {
2160                 struct scatterlist *sg = rsv_schp->buffer;
2161
2162                 if (sfp->save_scat_len > 0)
2163                         (sg + (req_schp->k_use_sg - 1))->length =
2164                             (unsigned) sfp->save_scat_len;
2165                 else
2166                         SCSI_LOG_TIMEOUT(1, printk ("sg_unlink_reserve: BAD save_scat_len\n"));
2167         }
2168         req_schp->k_use_sg = 0;
2169         req_schp->bufflen = 0;
2170         req_schp->buffer = NULL;
2171         req_schp->sglist_len = 0;
2172         sfp->save_scat_len = 0;
2173         srp->res_used = 0;
2174 }
2175
2176 static Sg_request *
2177 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2178 {
2179         Sg_request *resp;
2180         unsigned long iflags;
2181
2182         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2183         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2184                 /* look for requests that are ready + not SG_IO owned */
2185                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2186                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2187                         resp->done = 2; /* guard against other readers */
2188                         break;
2189                 }
2190         }
2191         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2192         return resp;
2193 }
2194
2195 #ifdef CONFIG_SCSI_PROC_FS
2196 static Sg_request *
2197 sg_get_nth_request(Sg_fd * sfp, int nth)
2198 {
2199         Sg_request *resp;
2200         unsigned long iflags;
2201         int k;
2202
2203         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2204         for (k = 0, resp = sfp->headrp; resp && (k < nth);
2205              ++k, resp = resp->nextrp) ;
2206         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2207         return resp;
2208 }
2209 #endif
2210
2211 /* always adds to end of list */
2212 static Sg_request *
2213 sg_add_request(Sg_fd * sfp)
2214 {
2215         int k;
2216         unsigned long iflags;
2217         Sg_request *resp;
2218         Sg_request *rp = sfp->req_arr;
2219
2220         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2221         resp = sfp->headrp;
2222         if (!resp) {
2223                 memset(rp, 0, sizeof (Sg_request));
2224                 rp->parentfp = sfp;
2225                 resp = rp;
2226                 sfp->headrp = resp;
2227         } else {
2228                 if (0 == sfp->cmd_q)
2229                         resp = NULL;    /* command queuing disallowed */
2230                 else {
2231                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2232                                 if (!rp->parentfp)
2233                                         break;
2234                         }
2235                         if (k < SG_MAX_QUEUE) {
2236                                 memset(rp, 0, sizeof (Sg_request));
2237                                 rp->parentfp = sfp;
2238                                 while (resp->nextrp)
2239                                         resp = resp->nextrp;
2240                                 resp->nextrp = rp;
2241                                 resp = rp;
2242                         } else
2243                                 resp = NULL;
2244                 }
2245         }
2246         if (resp) {
2247                 resp->nextrp = NULL;
2248                 resp->header.duration = jiffies_to_msecs(jiffies);
2249         }
2250         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2251         return resp;
2252 }
2253
2254 /* Return of 1 for found; 0 for not found */
2255 static int
2256 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2257 {
2258         Sg_request *prev_rp;
2259         Sg_request *rp;
2260         unsigned long iflags;
2261         int res = 0;
2262
2263         if ((!sfp) || (!srp) || (!sfp->headrp))
2264                 return res;
2265         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2266         prev_rp = sfp->headrp;
2267         if (srp == prev_rp) {
2268                 sfp->headrp = prev_rp->nextrp;
2269                 prev_rp->parentfp = NULL;
2270                 res = 1;
2271         } else {
2272                 while ((rp = prev_rp->nextrp)) {
2273                         if (srp == rp) {
2274                                 prev_rp->nextrp = rp->nextrp;
2275                                 rp->parentfp = NULL;
2276                                 res = 1;
2277                                 break;
2278                         }
2279                         prev_rp = rp;
2280                 }
2281         }
2282         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2283         return res;
2284 }
2285
2286 #ifdef CONFIG_SCSI_PROC_FS
2287 static Sg_fd *
2288 sg_get_nth_sfp(Sg_device * sdp, int nth)
2289 {
2290         Sg_fd *resp;
2291         unsigned long iflags;
2292         int k;
2293
2294         read_lock_irqsave(&sg_dev_arr_lock, iflags);
2295         for (k = 0, resp = sdp->headfp; resp && (k < nth);
2296              ++k, resp = resp->nextfp) ;
2297         read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2298         return resp;
2299 }
2300 #endif
2301
2302 static Sg_fd *
2303 sg_add_sfp(Sg_device * sdp, int dev)
2304 {
2305         Sg_fd *sfp;
2306         unsigned long iflags;
2307
2308         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2309         if (!sfp)
2310                 return NULL;
2311
2312         init_waitqueue_head(&sfp->read_wait);
2313         rwlock_init(&sfp->rq_list_lock);
2314
2315         sfp->timeout = SG_DEFAULT_TIMEOUT;
2316         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2317         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2318         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2319             sdp->device->host->unchecked_isa_dma : 1;
2320         sfp->cmd_q = SG_DEF_COMMAND_Q;
2321         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2322         sfp->parentdp = sdp;
2323         write_lock_irqsave(&sg_dev_arr_lock, iflags);
2324         if (!sdp->headfp)
2325                 sdp->headfp = sfp;
2326         else {                  /* add to tail of existing list */
2327                 Sg_fd *pfp = sdp->headfp;
2328                 while (pfp->nextfp)
2329                         pfp = pfp->nextfp;
2330                 pfp->nextfp = sfp;
2331         }
2332         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2333         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2334         sg_build_reserve(sfp, sg_big_buff);
2335         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2336                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2337         return sfp;
2338 }
2339
2340 static void
2341 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2342 {
2343         Sg_fd *fp;
2344         Sg_fd *prev_fp;
2345
2346         prev_fp = sdp->headfp;
2347         if (sfp == prev_fp)
2348                 sdp->headfp = prev_fp->nextfp;
2349         else {
2350                 while ((fp = prev_fp->nextfp)) {
2351                         if (sfp == fp) {
2352                                 prev_fp->nextfp = fp->nextfp;
2353                                 break;
2354                         }
2355                         prev_fp = fp;
2356                 }
2357         }
2358         if (sfp->reserve.bufflen > 0) {
2359                 SCSI_LOG_TIMEOUT(6, 
2360                         printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2361                         (int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2362                 sg_remove_scat(&sfp->reserve);
2363         }
2364         sfp->parentdp = NULL;
2365         SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2366         kfree(sfp);
2367 }
2368
2369 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2370 static int
2371 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2372 {
2373         Sg_request *srp;
2374         Sg_request *tsrp;
2375         int dirty = 0;
2376         int res = 0;
2377
2378         for (srp = sfp->headrp; srp; srp = tsrp) {
2379                 tsrp = srp->nextrp;
2380                 if (sg_srp_done(srp, sfp))
2381                         sg_finish_rem_req(srp);
2382                 else
2383                         ++dirty;
2384         }
2385         if (0 == dirty) {
2386                 unsigned long iflags;
2387
2388                 write_lock_irqsave(&sg_dev_arr_lock, iflags);
2389                 __sg_remove_sfp(sdp, sfp);
2390                 if (sdp->detached && (NULL == sdp->headfp)) {
2391                         int k, maxd;
2392
2393                         maxd = sg_dev_max;
2394                         for (k = 0; k < maxd; ++k) {
2395                                 if (sdp == sg_dev_arr[k])
2396                                         break;
2397                         }
2398                         if (k < maxd)
2399                                 sg_dev_arr[k] = NULL;
2400                         kfree((char *) sdp);
2401                         res = 1;
2402                 }
2403                 write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2404         } else {
2405                 /* MOD_INC's to inhibit unloading sg and associated adapter driver */
2406                 /* only bump the access_count if we actually succeeded in
2407                  * throwing another counter on the host module */
2408                 scsi_device_get(sdp->device);   /* XXX: retval ignored? */      
2409                 sfp->closed = 1;        /* flag dirty state on this fd */
2410                 SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2411                                   dirty));
2412         }
2413         return res;
2414 }
2415
2416 static int
2417 sg_res_in_use(Sg_fd * sfp)
2418 {
2419         const Sg_request *srp;
2420         unsigned long iflags;
2421
2422         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2423         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2424                 if (srp->res_used)
2425                         break;
2426         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2427         return srp ? 1 : 0;
2428 }
2429
2430 /* If retSzp==NULL want exact size or fail */
2431 static struct page *
2432 sg_page_malloc(int rqSz, int lowDma, int *retSzp)
2433 {
2434         struct page *resp = NULL;
2435         gfp_t page_mask;
2436         int order, a_size;
2437         int resSz = rqSz;
2438
2439         if (rqSz <= 0)
2440                 return resp;
2441
2442         if (lowDma)
2443                 page_mask = GFP_ATOMIC | GFP_DMA | __GFP_COMP | __GFP_NOWARN;
2444         else
2445                 page_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
2446
2447         for (order = 0, a_size = PAGE_SIZE; a_size < rqSz;
2448              order++, a_size <<= 1) ;
2449         resp = alloc_pages(page_mask, order);
2450         while ((!resp) && order && retSzp) {
2451                 --order;
2452                 a_size >>= 1;   /* divide by 2, until PAGE_SIZE */
2453                 resp =  alloc_pages(page_mask, order);  /* try half */
2454                 resSz = a_size;
2455         }
2456         if (resp) {
2457                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2458                         memset(page_address(resp), 0, resSz);
2459                 if (retSzp)
2460                         *retSzp = resSz;
2461         }
2462         return resp;
2463 }
2464
2465 static void
2466 sg_page_free(struct page *page, int size)
2467 {
2468         int order, a_size;
2469
2470         if (!page)
2471                 return;
2472         for (order = 0, a_size = PAGE_SIZE; a_size < size;
2473              order++, a_size <<= 1) ;
2474         __free_pages(page, order);
2475 }
2476
2477 #ifndef MAINTENANCE_IN_CMD
2478 #define MAINTENANCE_IN_CMD 0xa3
2479 #endif
2480
2481 static unsigned char allow_ops[] = { TEST_UNIT_READY, REQUEST_SENSE,
2482         INQUIRY, READ_CAPACITY, READ_BUFFER, READ_6, READ_10, READ_12,
2483         READ_16, MODE_SENSE, MODE_SENSE_10, LOG_SENSE, REPORT_LUNS,
2484         SERVICE_ACTION_IN, RECEIVE_DIAGNOSTIC, READ_LONG, MAINTENANCE_IN_CMD
2485 };
2486
2487 static int
2488 sg_allow_access(unsigned char opcode, char dev_type)
2489 {
2490         int k;
2491
2492         if (TYPE_SCANNER == dev_type)   /* TYPE_ROM maybe burner */
2493                 return 1;
2494         for (k = 0; k < sizeof (allow_ops); ++k) {
2495                 if (opcode == allow_ops[k])
2496                         return 1;
2497         }
2498         return 0;
2499 }
2500
2501 #ifdef CONFIG_SCSI_PROC_FS
2502 static int
2503 sg_last_dev(void)
2504 {
2505         int k;
2506         unsigned long iflags;
2507
2508         read_lock_irqsave(&sg_dev_arr_lock, iflags);
2509         for (k = sg_dev_max - 1; k >= 0; --k)
2510                 if (sg_dev_arr[k] && sg_dev_arr[k]->device)
2511                         break;
2512         read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2513         return k + 1;           /* origin 1 */
2514 }
2515 #endif
2516
2517 static Sg_device *
2518 sg_get_dev(int dev)
2519 {
2520         Sg_device *sdp = NULL;
2521         unsigned long iflags;
2522
2523         if (sg_dev_arr && (dev >= 0)) {
2524                 read_lock_irqsave(&sg_dev_arr_lock, iflags);
2525                 if (dev < sg_dev_max)
2526                         sdp = sg_dev_arr[dev];
2527                 read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2528         }
2529         return sdp;
2530 }
2531
2532 #ifdef CONFIG_SCSI_PROC_FS
2533
2534 static struct proc_dir_entry *sg_proc_sgp = NULL;
2535
2536 static char sg_proc_sg_dirname[] = "scsi/sg";
2537
2538 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2539
2540 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2541 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2542                                   size_t count, loff_t *off);
2543 static struct file_operations adio_fops = {
2544         /* .owner, .read and .llseek added in sg_proc_init() */
2545         .open = sg_proc_single_open_adio,
2546         .write = sg_proc_write_adio,
2547         .release = single_release,
2548 };
2549
2550 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2551 static ssize_t sg_proc_write_dressz(struct file *filp, 
2552                 const char __user *buffer, size_t count, loff_t *off);
2553 static struct file_operations dressz_fops = {
2554         .open = sg_proc_single_open_dressz,
2555         .write = sg_proc_write_dressz,
2556         .release = single_release,
2557 };
2558
2559 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2560 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2561 static struct file_operations version_fops = {
2562         .open = sg_proc_single_open_version,
2563         .release = single_release,
2564 };
2565
2566 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2567 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2568 static struct file_operations devhdr_fops = {
2569         .open = sg_proc_single_open_devhdr,
2570         .release = single_release,
2571 };
2572
2573 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2574 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2575 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2576 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2577 static void dev_seq_stop(struct seq_file *s, void *v);
2578 static struct file_operations dev_fops = {
2579         .open = sg_proc_open_dev,
2580         .release = seq_release,
2581 };
2582 static struct seq_operations dev_seq_ops = {
2583         .start = dev_seq_start,
2584         .next  = dev_seq_next,
2585         .stop  = dev_seq_stop,
2586         .show  = sg_proc_seq_show_dev,
2587 };
2588
2589 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2590 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2591 static struct file_operations devstrs_fops = {
2592         .open = sg_proc_open_devstrs,
2593         .release = seq_release,
2594 };
2595 static struct seq_operations devstrs_seq_ops = {
2596         .start = dev_seq_start,
2597         .next  = dev_seq_next,
2598         .stop  = dev_seq_stop,
2599         .show  = sg_proc_seq_show_devstrs,
2600 };
2601
2602 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2603 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2604 static struct file_operations debug_fops = {
2605         .open = sg_proc_open_debug,
2606         .release = seq_release,
2607 };
2608 static struct seq_operations debug_seq_ops = {
2609         .start = dev_seq_start,
2610         .next  = dev_seq_next,
2611         .stop  = dev_seq_stop,
2612         .show  = sg_proc_seq_show_debug,
2613 };
2614
2615
2616 struct sg_proc_leaf {
2617         const char * name;
2618         struct file_operations * fops;
2619 };
2620
2621 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2622         {"allow_dio", &adio_fops},
2623         {"debug", &debug_fops},
2624         {"def_reserved_size", &dressz_fops},
2625         {"device_hdr", &devhdr_fops},
2626         {"devices", &dev_fops},
2627         {"device_strs", &devstrs_fops},
2628         {"version", &version_fops}
2629 };
2630
2631 static int
2632 sg_proc_init(void)
2633 {
2634         int k, mask;
2635         int num_leaves =
2636             sizeof (sg_proc_leaf_arr) / sizeof (sg_proc_leaf_arr[0]);
2637         struct proc_dir_entry *pdep;
2638         struct sg_proc_leaf * leaf;
2639
2640         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2641         if (!sg_proc_sgp)
2642                 return 1;
2643         for (k = 0; k < num_leaves; ++k) {
2644                 leaf = &sg_proc_leaf_arr[k];
2645                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2646                 pdep = create_proc_entry(leaf->name, mask, sg_proc_sgp);
2647                 if (pdep) {
2648                         leaf->fops->owner = THIS_MODULE,
2649                         leaf->fops->read = seq_read,
2650                         leaf->fops->llseek = seq_lseek,
2651                         pdep->proc_fops = leaf->fops;
2652                 }
2653         }
2654         return 0;
2655 }
2656
2657 static void
2658 sg_proc_cleanup(void)
2659 {
2660         int k;
2661         int num_leaves =
2662             sizeof (sg_proc_leaf_arr) / sizeof (sg_proc_leaf_arr[0]);
2663
2664         if (!sg_proc_sgp)
2665                 return;
2666         for (k = 0; k < num_leaves; ++k)
2667                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2668         remove_proc_entry(sg_proc_sg_dirname, NULL);
2669 }
2670
2671
2672 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2673 {
2674         seq_printf(s, "%d\n", *((int *)s->private));
2675         return 0;
2676 }
2677
2678 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2679 {
2680         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2681 }
2682
2683 static ssize_t 
2684 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2685                    size_t count, loff_t *off)
2686 {
2687         int num;
2688         char buff[11];
2689
2690         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2691                 return -EACCES;
2692         num = (count < 10) ? count : 10;
2693         if (copy_from_user(buff, buffer, num))
2694                 return -EFAULT;
2695         buff[num] = '\0';
2696         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2697         return count;
2698 }
2699
2700 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2701 {
2702         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2703 }
2704
2705 static ssize_t 
2706 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2707                      size_t count, loff_t *off)
2708 {
2709         int num;
2710         unsigned long k = ULONG_MAX;
2711         char buff[11];
2712
2713         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2714                 return -EACCES;
2715         num = (count < 10) ? count : 10;
2716         if (copy_from_user(buff, buffer, num))
2717                 return -EFAULT;
2718         buff[num] = '\0';
2719         k = simple_strtoul(buff, NULL, 10);
2720         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2721                 sg_big_buff = k;
2722                 return count;
2723         }
2724         return -ERANGE;
2725 }
2726
2727 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2728 {
2729         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2730                    sg_version_date);
2731         return 0;
2732 }
2733
2734 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2735 {
2736         return single_open(file, sg_proc_seq_show_version, NULL);
2737 }
2738
2739 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2740 {
2741         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2742                    "online\n");
2743         return 0;
2744 }
2745
2746 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2747 {
2748         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2749 }
2750
2751 struct sg_proc_deviter {
2752         loff_t  index;
2753         size_t  max;
2754 };
2755
2756 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2757 {
2758         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2759
2760         s->private = it;
2761         if (! it)
2762                 return NULL;
2763
2764         if (NULL == sg_dev_arr)
2765                 return NULL;
2766         it->index = *pos;
2767         it->max = sg_last_dev();
2768         if (it->index >= it->max)
2769                 return NULL;
2770         return it;
2771 }
2772
2773 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2774 {
2775         struct sg_proc_deviter * it = s->private;
2776
2777         *pos = ++it->index;
2778         return (it->index < it->max) ? it : NULL;
2779 }
2780
2781 static void dev_seq_stop(struct seq_file *s, void *v)
2782 {
2783         kfree(s->private);
2784 }
2785
2786 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2787 {
2788         return seq_open(file, &dev_seq_ops);
2789 }
2790
2791 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2792 {
2793         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2794         Sg_device *sdp;
2795         struct scsi_device *scsidp;
2796
2797         sdp = it ? sg_get_dev(it->index) : NULL;
2798         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2799                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2800                               scsidp->host->host_no, scsidp->channel,
2801                               scsidp->id, scsidp->lun, (int) scsidp->type,
2802                               1,
2803                               (int) scsidp->queue_depth,
2804                               (int) scsidp->device_busy,
2805                               (int) scsi_device_online(scsidp));
2806         else
2807                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2808         return 0;
2809 }
2810
2811 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2812 {
2813         return seq_open(file, &devstrs_seq_ops);
2814 }
2815
2816 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2817 {
2818         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2819         Sg_device *sdp;
2820         struct scsi_device *scsidp;
2821
2822         sdp = it ? sg_get_dev(it->index) : NULL;
2823         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2824                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2825                            scsidp->vendor, scsidp->model, scsidp->rev);
2826         else
2827                 seq_printf(s, "<no active device>\n");
2828         return 0;
2829 }
2830
2831 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2832 {
2833         int k, m, new_interface, blen, usg;
2834         Sg_request *srp;
2835         Sg_fd *fp;
2836         const sg_io_hdr_t *hp;
2837         const char * cp;
2838         unsigned int ms;
2839
2840         for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
2841                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2842                            "(res)sgat=%d low_dma=%d\n", k + 1,
2843                            jiffies_to_msecs(fp->timeout),
2844                            fp->reserve.bufflen,
2845                            (int) fp->reserve.k_use_sg,
2846                            (int) fp->low_dma);
2847                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2848                            (int) fp->cmd_q, (int) fp->force_packid,
2849                            (int) fp->keep_orphan, (int) fp->closed);
2850                 for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
2851                         hp = &srp->header;
2852                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2853                         if (srp->res_used) {
2854                                 if (new_interface && 
2855                                     (SG_FLAG_MMAP_IO & hp->flags))
2856                                         cp = "     mmap>> ";
2857                                 else
2858                                         cp = "     rb>> ";
2859                         } else {
2860                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2861                                         cp = "     dio>> ";
2862                                 else
2863                                         cp = "     ";
2864                         }
2865                         seq_printf(s, cp);
2866                         blen = srp->data.bufflen;
2867                         usg = srp->data.k_use_sg;
2868                         seq_printf(s, srp->done ? 
2869                                    ((1 == srp->done) ?  "rcv:" : "fin:")
2870                                    : "act:");
2871                         seq_printf(s, " id=%d blen=%d",
2872                                    srp->header.pack_id, blen);
2873                         if (srp->done)
2874                                 seq_printf(s, " dur=%d", hp->duration);
2875                         else {
2876                                 ms = jiffies_to_msecs(jiffies);
2877                                 seq_printf(s, " t_o/elap=%d/%d",
2878                                         (new_interface ? hp->timeout :
2879                                                   jiffies_to_msecs(fp->timeout)),
2880                                         (ms > hp->duration ? ms - hp->duration : 0));
2881                         }
2882                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2883                                    (int) srp->data.cmd_opcode);
2884                 }
2885                 if (0 == m)
2886                         seq_printf(s, "     No requests active\n");
2887         }
2888 }
2889
2890 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2891 {
2892         return seq_open(file, &debug_seq_ops);
2893 }
2894
2895 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2896 {
2897         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2898         Sg_device *sdp;
2899
2900         if (it && (0 == it->index)) {
2901                 seq_printf(s, "dev_max(currently)=%d max_active_device=%d "
2902                            "(origin 1)\n", sg_dev_max, (int)it->max);
2903                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2904         }
2905         sdp = it ? sg_get_dev(it->index) : NULL;
2906         if (sdp) {
2907                 struct scsi_device *scsidp = sdp->device;
2908
2909                 if (NULL == scsidp) {
2910                         seq_printf(s, "device %d detached ??\n", 
2911                                    (int)it->index);
2912                         return 0;
2913                 }
2914
2915                 if (sg_get_nth_sfp(sdp, 0)) {
2916                         seq_printf(s, " >>> device=%s ",
2917                                 sdp->disk->disk_name);
2918                         if (sdp->detached)
2919                                 seq_printf(s, "detached pending close ");
2920                         else
2921                                 seq_printf
2922                                     (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2923                                      scsidp->host->host_no,
2924                                      scsidp->channel, scsidp->id,
2925                                      scsidp->lun,
2926                                      scsidp->host->hostt->emulated);
2927                         seq_printf(s, " sg_tablesize=%d excl=%d\n",
2928                                    sdp->sg_tablesize, sdp->exclude);
2929                 }
2930                 sg_proc_debug_helper(s, sdp);
2931         }
2932         return 0;
2933 }
2934
2935 #endif                          /* CONFIG_SCSI_PROC_FS */
2936
2937 module_init(init_sg);
2938 module_exit(exit_sg);