Merge ../scsi-misc-2.6
[linux-3.10.git] / drivers / scsi / sg.c
1 /*
2  *  History:
3  *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
4  *           to allow user process control of SCSI devices.
5  *  Development Sponsored by Killy Corp. NY NY
6  *
7  * Original driver (sg.c):
8  *        Copyright (C) 1992 Lawrence Foard
9  * Version 2 and 3 extensions to driver:
10  *        Copyright (C) 1998 - 2005 Douglas Gilbert
11  *
12  *  Modified  19-JAN-1998  Richard Gooch <rgooch@atnf.csiro.au>  Devfs support
13  *
14  * This program is free software; you can redistribute it and/or modify
15  * it under the terms of the GNU General Public License as published by
16  * the Free Software Foundation; either version 2, or (at your option)
17  * any later version.
18  *
19  */
20
21 static int sg_version_num = 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/module.h>
32
33 #include <linux/fs.h>
34 #include <linux/kernel.h>
35 #include <linux/sched.h>
36 #include <linux/string.h>
37 #include <linux/mm.h>
38 #include <linux/errno.h>
39 #include <linux/mtio.h>
40 #include <linux/ioctl.h>
41 #include <linux/fcntl.h>
42 #include <linux/init.h>
43 #include <linux/poll.h>
44 #include <linux/smp_lock.h>
45 #include <linux/moduleparam.h>
46 #include <linux/cdev.h>
47 #include <linux/seq_file.h>
48 #include <linux/blkdev.h>
49 #include <linux/delay.h>
50 #include <linux/scatterlist.h>
51
52 #include "scsi.h"
53 #include <scsi/scsi_dbg.h>
54 #include <scsi/scsi_host.h>
55 #include <scsi/scsi_driver.h>
56 #include <scsi/scsi_ioctl.h>
57 #include <scsi/sg.h>
58
59 #include "scsi_logging.h"
60
61 #ifdef CONFIG_SCSI_PROC_FS
62 #include <linux/proc_fs.h>
63 static char *sg_version_date = "20050908";
64
65 static int sg_proc_init(void);
66 static void sg_proc_cleanup(void);
67 #endif
68
69 #define SG_ALLOW_DIO_DEF 0
70 #define SG_ALLOW_DIO_CODE /* compile out by commenting this define */
71
72 #define SG_MAX_DEVS 32768
73
74 /*
75  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
76  * Then when using 32 bit integers x * m may overflow during the calculation.
77  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
78  * calculates the same, but prevents the overflow when both m and d
79  * are "small" numbers (like HZ and USER_HZ).
80  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
81  * in 32 bits.
82  */
83 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
84
85 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
86
87 int sg_big_buff = SG_DEF_RESERVED_SIZE;
88 /* N.B. This variable is readable and writeable via
89    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
90    of this size (or less if there is not enough memory) will be reserved
91    for use by this file descriptor. [Deprecated usage: this variable is also
92    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
93    the kernel (i.e. it is not a module).] */
94 static int def_reserved_size = -1;      /* picks up init parameter */
95 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
96
97 #define SG_SECTOR_SZ 512
98 #define SG_SECTOR_MSK (SG_SECTOR_SZ - 1)
99
100 #define SG_DEV_ARR_LUMP 32      /* amount to over allocate sg_dev_arr by */
101
102 static int sg_add(struct class_device *, struct class_interface *);
103 static void sg_remove(struct class_device *, struct class_interface *);
104
105 static DEFINE_RWLOCK(sg_dev_arr_lock);  /* Also used to lock
106                                                            file descriptor list for device */
107
108 static struct class_interface sg_interface = {
109         .add            = sg_add,
110         .remove         = sg_remove,
111 };
112
113 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
114         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
115         unsigned short sglist_len; /* size of malloc'd scatter-gather list ++ */
116         unsigned bufflen;       /* Size of (aggregate) data buffer */
117         unsigned b_malloc_len;  /* actual len malloc'ed in buffer */
118         struct scatterlist *buffer;/* scatter list */
119         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
120         unsigned char cmd_opcode; /* first byte of command */
121 } Sg_scatter_hold;
122
123 struct sg_device;               /* forward declarations */
124 struct sg_fd;
125
126 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
127         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
128         struct sg_fd *parentfp; /* NULL -> not in use */
129         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
130         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
131         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
132         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
133         char orphan;            /* 1 -> drop on sight, 0 -> normal */
134         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
135         volatile char done;     /* 0->before bh, 1->before read, 2->read */
136 } Sg_request;
137
138 typedef struct sg_fd {          /* holds the state of a file descriptor */
139         struct sg_fd *nextfp;   /* NULL when last opened fd on this device */
140         struct sg_device *parentdp;     /* owning device */
141         wait_queue_head_t read_wait;    /* queue read until command done */
142         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
143         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
144         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
145         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
146         unsigned save_scat_len; /* original length of trunc. scat. element */
147         Sg_request *headrp;     /* head of request slist, NULL->empty */
148         struct fasync_struct *async_qp; /* used by asynchronous notification */
149         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
150         char low_dma;           /* as in parent but possibly overridden to 1 */
151         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
152         volatile char closed;   /* 1 -> fd closed but request(s) outstanding */
153         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
154         char next_cmd_len;      /* 0 -> automatic (def), >0 -> use on next write() */
155         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
156         char mmap_called;       /* 0 -> mmap() never called on this fd */
157 } Sg_fd;
158
159 typedef struct sg_device { /* holds the state of each scsi generic device */
160         struct scsi_device *device;
161         wait_queue_head_t o_excl_wait;  /* queue open() when O_EXCL in use */
162         int sg_tablesize;       /* adapter's max scatter-gather table size */
163         Sg_fd *headfp;          /* first open fd belonging to this device */
164         volatile char detached; /* 0->attached, 1->detached pending removal */
165         volatile char exclude;  /* opened for exclusive access */
166         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
167         struct gendisk *disk;
168         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
169 } Sg_device;
170
171 static int sg_fasync(int fd, struct file *filp, int mode);
172 /* tasklet or soft irq callback */
173 static void sg_cmd_done(void *data, char *sense, int result, int resid);
174 static int sg_start_req(Sg_request * srp);
175 static void sg_finish_rem_req(Sg_request * srp);
176 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
177 static int sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp,
178                          int tablesize);
179 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
180                            Sg_request * srp);
181 static ssize_t sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
182                             int blocking, int read_only, Sg_request ** o_srp);
183 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
184                            unsigned char *cmnd, int timeout, int blocking);
185 static int sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
186                       int wr_xf, int *countp, unsigned char __user **up);
187 static int sg_write_xfer(Sg_request * srp);
188 static int sg_read_xfer(Sg_request * srp);
189 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
190 static void sg_remove_scat(Sg_scatter_hold * schp);
191 static void sg_build_reserve(Sg_fd * sfp, int req_size);
192 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
193 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
194 static struct page *sg_page_malloc(int rqSz, int lowDma, int *retSzp);
195 static void sg_page_free(struct page *page, int size);
196 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
197 static int sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
198 static void __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
199 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
200 static Sg_request *sg_add_request(Sg_fd * sfp);
201 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
202 static int sg_res_in_use(Sg_fd * sfp);
203 static int sg_allow_access(unsigned char opcode, char dev_type);
204 static int sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len);
205 static Sg_device *sg_get_dev(int dev);
206 #ifdef CONFIG_SCSI_PROC_FS
207 static int sg_last_dev(void);
208 #endif
209
210 static Sg_device **sg_dev_arr = NULL;
211 static int sg_dev_max;
212 static int sg_nr_dev;
213
214 #define SZ_SG_HEADER sizeof(struct sg_header)
215 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
216 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
217 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
218
219 static int
220 sg_open(struct inode *inode, struct file *filp)
221 {
222         int dev = iminor(inode);
223         int flags = filp->f_flags;
224         struct request_queue *q;
225         Sg_device *sdp;
226         Sg_fd *sfp;
227         int res;
228         int retval;
229
230         nonseekable_open(inode, filp);
231         SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
232         sdp = sg_get_dev(dev);
233         if ((!sdp) || (!sdp->device))
234                 return -ENXIO;
235         if (sdp->detached)
236                 return -ENODEV;
237
238         /* This driver's module count bumped by fops_get in <linux/fs.h> */
239         /* Prevent the device driver from vanishing while we sleep */
240         retval = scsi_device_get(sdp->device);
241         if (retval)
242                 return retval;
243
244         if (!((flags & O_NONBLOCK) ||
245               scsi_block_when_processing_errors(sdp->device))) {
246                 retval = -ENXIO;
247                 /* we are in error recovery for this device */
248                 goto error_out;
249         }
250
251         if (flags & O_EXCL) {
252                 if (O_RDONLY == (flags & O_ACCMODE)) {
253                         retval = -EPERM; /* Can't lock it with read only access */
254                         goto error_out;
255                 }
256                 if (sdp->headfp && (flags & O_NONBLOCK)) {
257                         retval = -EBUSY;
258                         goto error_out;
259                 }
260                 res = 0;
261                 __wait_event_interruptible(sdp->o_excl_wait,
262                         ((sdp->headfp || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
263                 if (res) {
264                         retval = res;   /* -ERESTARTSYS because signal hit process */
265                         goto error_out;
266                 }
267         } else if (sdp->exclude) {      /* some other fd has an exclusive lock on dev */
268                 if (flags & O_NONBLOCK) {
269                         retval = -EBUSY;
270                         goto error_out;
271                 }
272                 res = 0;
273                 __wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
274                                            res);
275                 if (res) {
276                         retval = res;   /* -ERESTARTSYS because signal hit process */
277                         goto error_out;
278                 }
279         }
280         if (sdp->detached) {
281                 retval = -ENODEV;
282                 goto error_out;
283         }
284         if (!sdp->headfp) {     /* no existing opens on this device */
285                 sdp->sgdebug = 0;
286                 q = sdp->device->request_queue;
287                 sdp->sg_tablesize = min(q->max_hw_segments,
288                                         q->max_phys_segments);
289         }
290         if ((sfp = sg_add_sfp(sdp, dev)))
291                 filp->private_data = sfp;
292         else {
293                 if (flags & O_EXCL)
294                         sdp->exclude = 0;       /* undo if error */
295                 retval = -ENOMEM;
296                 goto error_out;
297         }
298         return 0;
299
300       error_out:
301         scsi_device_put(sdp->device);
302         return retval;
303 }
304
305 /* Following function was formerly called 'sg_close' */
306 static int
307 sg_release(struct inode *inode, struct file *filp)
308 {
309         Sg_device *sdp;
310         Sg_fd *sfp;
311
312         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
313                 return -ENXIO;
314         SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
315         sg_fasync(-1, filp, 0); /* remove filp from async notification list */
316         if (0 == sg_remove_sfp(sdp, sfp)) {     /* Returns 1 when sdp gone */
317                 if (!sdp->detached) {
318                         scsi_device_put(sdp->device);
319                 }
320                 sdp->exclude = 0;
321                 wake_up_interruptible(&sdp->o_excl_wait);
322         }
323         return 0;
324 }
325
326 static ssize_t
327 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
328 {
329         Sg_device *sdp;
330         Sg_fd *sfp;
331         Sg_request *srp;
332         int req_pack_id = -1;
333         sg_io_hdr_t *hp;
334         struct sg_header *old_hdr = NULL;
335         int retval = 0;
336
337         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
338                 return -ENXIO;
339         SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
340                                    sdp->disk->disk_name, (int) count));
341
342         if (!access_ok(VERIFY_WRITE, buf, count))
343                 return -EFAULT;
344         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
345                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
346                 if (!old_hdr)
347                         return -ENOMEM;
348                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
349                         retval = -EFAULT;
350                         goto free_old_hdr;
351                 }
352                 if (old_hdr->reply_len < 0) {
353                         if (count >= SZ_SG_IO_HDR) {
354                                 sg_io_hdr_t *new_hdr;
355                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
356                                 if (!new_hdr) {
357                                         retval = -ENOMEM;
358                                         goto free_old_hdr;
359                                 }
360                                 retval =__copy_from_user
361                                     (new_hdr, buf, SZ_SG_IO_HDR);
362                                 req_pack_id = new_hdr->pack_id;
363                                 kfree(new_hdr);
364                                 if (retval) {
365                                         retval = -EFAULT;
366                                         goto free_old_hdr;
367                                 }
368                         }
369                 } else
370                         req_pack_id = old_hdr->pack_id;
371         }
372         srp = sg_get_rq_mark(sfp, req_pack_id);
373         if (!srp) {             /* now wait on packet to arrive */
374                 if (sdp->detached) {
375                         retval = -ENODEV;
376                         goto free_old_hdr;
377                 }
378                 if (filp->f_flags & O_NONBLOCK) {
379                         retval = -EAGAIN;
380                         goto free_old_hdr;
381                 }
382                 while (1) {
383                         retval = 0; /* following macro beats race condition */
384                         __wait_event_interruptible(sfp->read_wait,
385                                 (sdp->detached ||
386                                 (srp = sg_get_rq_mark(sfp, req_pack_id))), 
387                                 retval);
388                         if (sdp->detached) {
389                                 retval = -ENODEV;
390                                 goto free_old_hdr;
391                         }
392                         if (0 == retval)
393                                 break;
394
395                         /* -ERESTARTSYS as signal hit process */
396                         goto free_old_hdr;
397                 }
398         }
399         if (srp->header.interface_id != '\0') {
400                 retval = sg_new_read(sfp, buf, count, srp);
401                 goto free_old_hdr;
402         }
403
404         hp = &srp->header;
405         if (old_hdr == NULL) {
406                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
407                 if (! old_hdr) {
408                         retval = -ENOMEM;
409                         goto free_old_hdr;
410                 }
411         }
412         memset(old_hdr, 0, SZ_SG_HEADER);
413         old_hdr->reply_len = (int) hp->timeout;
414         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
415         old_hdr->pack_id = hp->pack_id;
416         old_hdr->twelve_byte =
417             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
418         old_hdr->target_status = hp->masked_status;
419         old_hdr->host_status = hp->host_status;
420         old_hdr->driver_status = hp->driver_status;
421         if ((CHECK_CONDITION & hp->masked_status) ||
422             (DRIVER_SENSE & hp->driver_status))
423                 memcpy(old_hdr->sense_buffer, srp->sense_b,
424                        sizeof (old_hdr->sense_buffer));
425         switch (hp->host_status) {
426         /* This setup of 'result' is for backward compatibility and is best
427            ignored by the user who should use target, host + driver status */
428         case DID_OK:
429         case DID_PASSTHROUGH:
430         case DID_SOFT_ERROR:
431                 old_hdr->result = 0;
432                 break;
433         case DID_NO_CONNECT:
434         case DID_BUS_BUSY:
435         case DID_TIME_OUT:
436                 old_hdr->result = EBUSY;
437                 break;
438         case DID_BAD_TARGET:
439         case DID_ABORT:
440         case DID_PARITY:
441         case DID_RESET:
442         case DID_BAD_INTR:
443                 old_hdr->result = EIO;
444                 break;
445         case DID_ERROR:
446                 old_hdr->result = (srp->sense_b[0] == 0 && 
447                                   hp->masked_status == GOOD) ? 0 : EIO;
448                 break;
449         default:
450                 old_hdr->result = EIO;
451                 break;
452         }
453
454         /* Now copy the result back to the user buffer.  */
455         if (count >= SZ_SG_HEADER) {
456                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
457                         retval = -EFAULT;
458                         goto free_old_hdr;
459                 }
460                 buf += SZ_SG_HEADER;
461                 if (count > old_hdr->reply_len)
462                         count = old_hdr->reply_len;
463                 if (count > SZ_SG_HEADER) {
464                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
465                                 retval = -EFAULT;
466                                 goto free_old_hdr;
467                         }
468                 }
469         } else
470                 count = (old_hdr->result == 0) ? 0 : -EIO;
471         sg_finish_rem_req(srp);
472         retval = count;
473 free_old_hdr:
474         kfree(old_hdr);
475         return retval;
476 }
477
478 static ssize_t
479 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
480 {
481         sg_io_hdr_t *hp = &srp->header;
482         int err = 0;
483         int len;
484
485         if (count < SZ_SG_IO_HDR) {
486                 err = -EINVAL;
487                 goto err_out;
488         }
489         hp->sb_len_wr = 0;
490         if ((hp->mx_sb_len > 0) && hp->sbp) {
491                 if ((CHECK_CONDITION & hp->masked_status) ||
492                     (DRIVER_SENSE & hp->driver_status)) {
493                         int sb_len = SCSI_SENSE_BUFFERSIZE;
494                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
495                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
496                         len = (len > sb_len) ? sb_len : len;
497                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
498                                 err = -EFAULT;
499                                 goto err_out;
500                         }
501                         hp->sb_len_wr = len;
502                 }
503         }
504         if (hp->masked_status || hp->host_status || hp->driver_status)
505                 hp->info |= SG_INFO_CHECK;
506         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
507                 err = -EFAULT;
508                 goto err_out;
509         }
510         err = sg_read_xfer(srp);
511       err_out:
512         sg_finish_rem_req(srp);
513         return (0 == err) ? count : err;
514 }
515
516 static ssize_t
517 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
518 {
519         int mxsize, cmd_size, k;
520         int input_size, blocking;
521         unsigned char opcode;
522         Sg_device *sdp;
523         Sg_fd *sfp;
524         Sg_request *srp;
525         struct sg_header old_hdr;
526         sg_io_hdr_t *hp;
527         unsigned char cmnd[MAX_COMMAND_SIZE];
528
529         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
530                 return -ENXIO;
531         SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
532                                    sdp->disk->disk_name, (int) count));
533         if (sdp->detached)
534                 return -ENODEV;
535         if (!((filp->f_flags & O_NONBLOCK) ||
536               scsi_block_when_processing_errors(sdp->device)))
537                 return -ENXIO;
538
539         if (!access_ok(VERIFY_READ, buf, count))
540                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
541         if (count < SZ_SG_HEADER)
542                 return -EIO;
543         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
544                 return -EFAULT;
545         blocking = !(filp->f_flags & O_NONBLOCK);
546         if (old_hdr.reply_len < 0)
547                 return sg_new_write(sfp, buf, count, blocking, 0, NULL);
548         if (count < (SZ_SG_HEADER + 6))
549                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
550
551         if (!(srp = sg_add_request(sfp))) {
552                 SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
553                 return -EDOM;
554         }
555         buf += SZ_SG_HEADER;
556         __get_user(opcode, buf);
557         if (sfp->next_cmd_len > 0) {
558                 if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
559                         SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
560                         sfp->next_cmd_len = 0;
561                         sg_remove_request(sfp, srp);
562                         return -EIO;
563                 }
564                 cmd_size = sfp->next_cmd_len;
565                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
566         } else {
567                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
568                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
569                         cmd_size = 12;
570         }
571         SCSI_LOG_TIMEOUT(4, printk(
572                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
573 /* Determine buffer size.  */
574         input_size = count - cmd_size;
575         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
576         mxsize -= SZ_SG_HEADER;
577         input_size -= SZ_SG_HEADER;
578         if (input_size < 0) {
579                 sg_remove_request(sfp, srp);
580                 return -EIO;    /* User did not pass enough bytes for this command. */
581         }
582         hp = &srp->header;
583         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
584         hp->cmd_len = (unsigned char) cmd_size;
585         hp->iovec_count = 0;
586         hp->mx_sb_len = 0;
587         if (input_size > 0)
588                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
589                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
590         else
591                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
592         hp->dxfer_len = mxsize;
593         hp->dxferp = (char __user *)buf + cmd_size;
594         hp->sbp = NULL;
595         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
596         hp->flags = input_size; /* structure abuse ... */
597         hp->pack_id = old_hdr.pack_id;
598         hp->usr_ptr = NULL;
599         if (__copy_from_user(cmnd, buf, cmd_size))
600                 return -EFAULT;
601         /*
602          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
603          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
604          * is a non-zero input_size, so emit a warning.
605          */
606         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV)
607                 if (printk_ratelimit())
608                         printk(KERN_WARNING
609                                "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
610                                "guessing data in;\n" KERN_WARNING "   "
611                                "program %s not setting count and/or reply_len properly\n",
612                                old_hdr.reply_len - (int)SZ_SG_HEADER,
613                                input_size, (unsigned int) cmnd[0],
614                                current->comm);
615         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
616         return (k < 0) ? k : count;
617 }
618
619 static ssize_t
620 sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
621              int blocking, int read_only, Sg_request ** o_srp)
622 {
623         int k;
624         Sg_request *srp;
625         sg_io_hdr_t *hp;
626         unsigned char cmnd[MAX_COMMAND_SIZE];
627         int timeout;
628         unsigned long ul_timeout;
629
630         if (count < SZ_SG_IO_HDR)
631                 return -EINVAL;
632         if (!access_ok(VERIFY_READ, buf, count))
633                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
634
635         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
636         if (!(srp = sg_add_request(sfp))) {
637                 SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
638                 return -EDOM;
639         }
640         hp = &srp->header;
641         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
642                 sg_remove_request(sfp, srp);
643                 return -EFAULT;
644         }
645         if (hp->interface_id != 'S') {
646                 sg_remove_request(sfp, srp);
647                 return -ENOSYS;
648         }
649         if (hp->flags & SG_FLAG_MMAP_IO) {
650                 if (hp->dxfer_len > sfp->reserve.bufflen) {
651                         sg_remove_request(sfp, srp);
652                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
653                 }
654                 if (hp->flags & SG_FLAG_DIRECT_IO) {
655                         sg_remove_request(sfp, srp);
656                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
657                 }
658                 if (sg_res_in_use(sfp)) {
659                         sg_remove_request(sfp, srp);
660                         return -EBUSY;  /* reserve buffer already being used */
661                 }
662         }
663         ul_timeout = msecs_to_jiffies(srp->header.timeout);
664         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
665         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
666                 sg_remove_request(sfp, srp);
667                 return -EMSGSIZE;
668         }
669         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
670                 sg_remove_request(sfp, srp);
671                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
672         }
673         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
674                 sg_remove_request(sfp, srp);
675                 return -EFAULT;
676         }
677         if (read_only &&
678             (!sg_allow_access(cmnd[0], sfp->parentdp->device->type))) {
679                 sg_remove_request(sfp, srp);
680                 return -EPERM;
681         }
682         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
683         if (k < 0)
684                 return k;
685         if (o_srp)
686                 *o_srp = srp;
687         return count;
688 }
689
690 static int
691 sg_common_write(Sg_fd * sfp, Sg_request * srp,
692                 unsigned char *cmnd, int timeout, int blocking)
693 {
694         int k, data_dir;
695         Sg_device *sdp = sfp->parentdp;
696         sg_io_hdr_t *hp = &srp->header;
697
698         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
699         hp->status = 0;
700         hp->masked_status = 0;
701         hp->msg_status = 0;
702         hp->info = 0;
703         hp->host_status = 0;
704         hp->driver_status = 0;
705         hp->resid = 0;
706         SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
707                           (int) cmnd[0], (int) hp->cmd_len));
708
709         if ((k = sg_start_req(srp))) {
710                 SCSI_LOG_TIMEOUT(1, printk("sg_write: start_req err=%d\n", k));
711                 sg_finish_rem_req(srp);
712                 return k;       /* probably out of space --> ENOMEM */
713         }
714         if ((k = sg_write_xfer(srp))) {
715                 SCSI_LOG_TIMEOUT(1, printk("sg_write: write_xfer, bad address\n"));
716                 sg_finish_rem_req(srp);
717                 return k;
718         }
719         if (sdp->detached) {
720                 sg_finish_rem_req(srp);
721                 return -ENODEV;
722         }
723
724         switch (hp->dxfer_direction) {
725         case SG_DXFER_TO_FROM_DEV:
726         case SG_DXFER_FROM_DEV:
727                 data_dir = DMA_FROM_DEVICE;
728                 break;
729         case SG_DXFER_TO_DEV:
730                 data_dir = DMA_TO_DEVICE;
731                 break;
732         case SG_DXFER_UNKNOWN:
733                 data_dir = DMA_BIDIRECTIONAL;
734                 break;
735         default:
736                 data_dir = DMA_NONE;
737                 break;
738         }
739         hp->duration = jiffies_to_msecs(jiffies);
740 /* Now send everything of to mid-level. The next time we hear about this
741    packet is when sg_cmd_done() is called (i.e. a callback). */
742         if (scsi_execute_async(sdp->device, cmnd, hp->cmd_len, data_dir, srp->data.buffer,
743                                 hp->dxfer_len, srp->data.k_use_sg, timeout,
744                                 SG_DEFAULT_RETRIES, srp, sg_cmd_done,
745                                 GFP_ATOMIC)) {
746                 SCSI_LOG_TIMEOUT(1, printk("sg_write: scsi_execute_async failed\n"));
747                 /*
748                  * most likely out of mem, but could also be a bad map
749                  */
750                 sg_finish_rem_req(srp);
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         unsigned long iflags;
1405
1406         disk = alloc_disk(1);
1407         if (!disk) {
1408                 printk(KERN_WARNING "alloc_disk failed\n");
1409                 return -ENOMEM;
1410         }
1411         disk->major = SCSI_GENERIC_MAJOR;
1412
1413         error = -ENOMEM;
1414         cdev = cdev_alloc();
1415         if (!cdev) {
1416                 printk(KERN_WARNING "cdev_alloc failed\n");
1417                 goto out;
1418         }
1419         cdev->owner = THIS_MODULE;
1420         cdev->ops = &sg_fops;
1421
1422         error = sg_alloc(disk, scsidp);
1423         if (error < 0) {
1424                 printk(KERN_WARNING "sg_alloc failed\n");
1425                 goto out;
1426         }
1427         k = error;
1428         sdp = sg_dev_arr[k];
1429
1430         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, k), 1);
1431         if (error)
1432                 goto cdev_add_err;
1433
1434         sdp->cdev = cdev;
1435         if (sg_sysfs_valid) {
1436                 struct class_device * sg_class_member;
1437
1438                 sg_class_member = class_device_create(sg_sysfs_class, NULL,
1439                                 MKDEV(SCSI_GENERIC_MAJOR, k), 
1440                                 cl_dev->dev, "%s", 
1441                                 disk->disk_name);
1442                 if (IS_ERR(sg_class_member))
1443                         printk(KERN_WARNING "sg_add: "
1444                                 "class_device_create failed\n");
1445                 class_set_devdata(sg_class_member, sdp);
1446                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj, 
1447                                           &sg_class_member->kobj, "generic");
1448                 if (error)
1449                         printk(KERN_ERR "sg_add: unable to make symlink "
1450                                         "'generic' back to sg%d\n", k);
1451         } else
1452                 printk(KERN_WARNING "sg_add: sg_sys INvalid\n");
1453
1454         sdev_printk(KERN_NOTICE, scsidp,
1455                     "Attached scsi generic sg%d type %d\n", k,scsidp->type);
1456
1457         return 0;
1458
1459 cdev_add_err:
1460         write_lock_irqsave(&sg_dev_arr_lock, iflags);
1461         kfree(sg_dev_arr[k]);
1462         sg_dev_arr[k] = NULL;
1463         sg_nr_dev--;
1464         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1465
1466 out:
1467         put_disk(disk);
1468         if (cdev)
1469                 cdev_del(cdev);
1470         return error;
1471 }
1472
1473 static void
1474 sg_remove(struct class_device *cl_dev, struct class_interface *cl_intf)
1475 {
1476         struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1477         Sg_device *sdp = NULL;
1478         unsigned long iflags;
1479         Sg_fd *sfp;
1480         Sg_fd *tsfp;
1481         Sg_request *srp;
1482         Sg_request *tsrp;
1483         int k, delay;
1484
1485         if (NULL == sg_dev_arr)
1486                 return;
1487         delay = 0;
1488         write_lock_irqsave(&sg_dev_arr_lock, iflags);
1489         for (k = 0; k < sg_dev_max; k++) {
1490                 sdp = sg_dev_arr[k];
1491                 if ((NULL == sdp) || (sdp->device != scsidp))
1492                         continue;       /* dirty but lowers nesting */
1493                 if (sdp->headfp) {
1494                         sdp->detached = 1;
1495                         for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1496                                 tsfp = sfp->nextfp;
1497                                 for (srp = sfp->headrp; srp; srp = tsrp) {
1498                                         tsrp = srp->nextrp;
1499                                         if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
1500                                                 sg_finish_rem_req(srp);
1501                                 }
1502                                 if (sfp->closed) {
1503                                         scsi_device_put(sdp->device);
1504                                         __sg_remove_sfp(sdp, sfp);
1505                                 } else {
1506                                         delay = 1;
1507                                         wake_up_interruptible(&sfp->read_wait);
1508                                         kill_fasync(&sfp->async_qp, SIGPOLL,
1509                                                     POLL_HUP);
1510                                 }
1511                         }
1512                         SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d, dirty\n", k));
1513                         if (NULL == sdp->headfp) {
1514                                 sg_dev_arr[k] = NULL;
1515                         }
1516                 } else {        /* nothing active, simple case */
1517                         SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d\n", k));
1518                         sg_dev_arr[k] = NULL;
1519                 }
1520                 sg_nr_dev--;
1521                 break;
1522         }
1523         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1524
1525         if (sdp) {
1526                 sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1527                 class_device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, k));
1528                 cdev_del(sdp->cdev);
1529                 sdp->cdev = NULL;
1530                 put_disk(sdp->disk);
1531                 sdp->disk = NULL;
1532                 if (NULL == sdp->headfp)
1533                         kfree((char *) sdp);
1534         }
1535
1536         if (delay)
1537                 msleep(10);     /* dirty detach so delay device destruction */
1538 }
1539
1540 /* Set 'perm' (4th argument) to 0 to disable module_param's definition
1541  * of sysfs parameters (which module_param doesn't yet support).
1542  * Sysfs parameters defined explicitly below.
1543  */
1544 module_param_named(def_reserved_size, def_reserved_size, int, S_IRUGO);
1545 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1546
1547 MODULE_AUTHOR("Douglas Gilbert");
1548 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1549 MODULE_LICENSE("GPL");
1550 MODULE_VERSION(SG_VERSION_STR);
1551 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1552
1553 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1554 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1555
1556 static int __init
1557 init_sg(void)
1558 {
1559         int rc;
1560
1561         if (def_reserved_size >= 0)
1562                 sg_big_buff = def_reserved_size;
1563
1564         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), 
1565                                     SG_MAX_DEVS, "sg");
1566         if (rc)
1567                 return rc;
1568         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1569         if ( IS_ERR(sg_sysfs_class) ) {
1570                 rc = PTR_ERR(sg_sysfs_class);
1571                 goto err_out;
1572         }
1573         sg_sysfs_valid = 1;
1574         rc = scsi_register_interface(&sg_interface);
1575         if (0 == rc) {
1576 #ifdef CONFIG_SCSI_PROC_FS
1577                 sg_proc_init();
1578 #endif                          /* CONFIG_SCSI_PROC_FS */
1579                 return 0;
1580         }
1581         class_destroy(sg_sysfs_class);
1582 err_out:
1583         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1584         return rc;
1585 }
1586
1587 static void __exit
1588 exit_sg(void)
1589 {
1590 #ifdef CONFIG_SCSI_PROC_FS
1591         sg_proc_cleanup();
1592 #endif                          /* CONFIG_SCSI_PROC_FS */
1593         scsi_unregister_interface(&sg_interface);
1594         class_destroy(sg_sysfs_class);
1595         sg_sysfs_valid = 0;
1596         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1597                                  SG_MAX_DEVS);
1598         kfree((char *)sg_dev_arr);
1599         sg_dev_arr = NULL;
1600         sg_dev_max = 0;
1601 }
1602
1603 static int
1604 sg_start_req(Sg_request * srp)
1605 {
1606         int res;
1607         Sg_fd *sfp = srp->parentfp;
1608         sg_io_hdr_t *hp = &srp->header;
1609         int dxfer_len = (int) hp->dxfer_len;
1610         int dxfer_dir = hp->dxfer_direction;
1611         Sg_scatter_hold *req_schp = &srp->data;
1612         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1613
1614         SCSI_LOG_TIMEOUT(4, printk("sg_start_req: dxfer_len=%d\n", dxfer_len));
1615         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1616                 return 0;
1617         if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) &&
1618             (dxfer_dir != SG_DXFER_UNKNOWN) && (0 == hp->iovec_count) &&
1619             (!sfp->parentdp->device->host->unchecked_isa_dma)) {
1620                 res = sg_build_direct(srp, sfp, dxfer_len);
1621                 if (res <= 0)   /* -ve -> error, 0 -> done, 1 -> try indirect */
1622                         return res;
1623         }
1624         if ((!sg_res_in_use(sfp)) && (dxfer_len <= rsv_schp->bufflen))
1625                 sg_link_reserve(sfp, srp, dxfer_len);
1626         else {
1627                 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1628                 if (res) {
1629                         sg_remove_scat(req_schp);
1630                         return res;
1631                 }
1632         }
1633         return 0;
1634 }
1635
1636 static void
1637 sg_finish_rem_req(Sg_request * srp)
1638 {
1639         Sg_fd *sfp = srp->parentfp;
1640         Sg_scatter_hold *req_schp = &srp->data;
1641
1642         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1643         if (srp->res_used)
1644                 sg_unlink_reserve(sfp, srp);
1645         else
1646                 sg_remove_scat(req_schp);
1647         sg_remove_request(sfp, srp);
1648 }
1649
1650 static int
1651 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1652 {
1653         int sg_bufflen = tablesize * sizeof(struct scatterlist);
1654         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1655
1656         /*
1657          * TODO: test without low_dma, we should not need it since
1658          * the block layer will bounce the buffer for us
1659          *
1660          * XXX(hch): we shouldn't need GFP_DMA for the actual S/G list.
1661          */
1662         if (sfp->low_dma)
1663                  gfp_flags |= GFP_DMA;
1664         schp->buffer = kzalloc(sg_bufflen, gfp_flags);
1665         if (!schp->buffer)
1666                 return -ENOMEM;
1667         schp->sglist_len = sg_bufflen;
1668         return tablesize;       /* number of scat_gath elements allocated */
1669 }
1670
1671 #ifdef SG_ALLOW_DIO_CODE
1672 /* vvvvvvvv  following code borrowed from st driver's direct IO vvvvvvvvv */
1673         /* TODO: hopefully we can use the generic block layer code */
1674
1675 /* Pin down user pages and put them into a scatter gather list. Returns <= 0 if
1676    - mapping of all pages not successful
1677    (i.e., either completely successful or fails)
1678 */
1679 static int 
1680 st_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages, 
1681                   unsigned long uaddr, size_t count, int rw)
1682 {
1683         unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
1684         unsigned long start = uaddr >> PAGE_SHIFT;
1685         const int nr_pages = end - start;
1686         int res, i, j;
1687         struct page **pages;
1688
1689         /* User attempted Overflow! */
1690         if ((uaddr + count) < uaddr)
1691                 return -EINVAL;
1692
1693         /* Too big */
1694         if (nr_pages > max_pages)
1695                 return -ENOMEM;
1696
1697         /* Hmm? */
1698         if (count == 0)
1699                 return 0;
1700
1701         if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_ATOMIC)) == NULL)
1702                 return -ENOMEM;
1703
1704         /* Try to fault in all of the necessary pages */
1705         down_read(&current->mm->mmap_sem);
1706         /* rw==READ means read from drive, write into memory area */
1707         res = get_user_pages(
1708                 current,
1709                 current->mm,
1710                 uaddr,
1711                 nr_pages,
1712                 rw == READ,
1713                 0, /* don't force */
1714                 pages,
1715                 NULL);
1716         up_read(&current->mm->mmap_sem);
1717
1718         /* Errors and no page mapped should return here */
1719         if (res < nr_pages)
1720                 goto out_unmap;
1721
1722         for (i=0; i < nr_pages; i++) {
1723                 /* FIXME: flush superflous for rw==READ,
1724                  * probably wrong function for rw==WRITE
1725                  */
1726                 flush_dcache_page(pages[i]);
1727                 /* ?? Is locking needed? I don't think so */
1728                 /* if (TestSetPageLocked(pages[i]))
1729                    goto out_unlock; */
1730         }
1731
1732         sgl[0].page = pages[0];
1733         sgl[0].offset = uaddr & ~PAGE_MASK;
1734         if (nr_pages > 1) {
1735                 sgl[0].length = PAGE_SIZE - sgl[0].offset;
1736                 count -= sgl[0].length;
1737                 for (i=1; i < nr_pages ; i++) {
1738                         sgl[i].page = pages[i]; 
1739                         sgl[i].length = count < PAGE_SIZE ? count : PAGE_SIZE;
1740                         count -= PAGE_SIZE;
1741                 }
1742         }
1743         else {
1744                 sgl[0].length = count;
1745         }
1746
1747         kfree(pages);
1748         return nr_pages;
1749
1750  out_unmap:
1751         if (res > 0) {
1752                 for (j=0; j < res; j++)
1753                         page_cache_release(pages[j]);
1754                 res = 0;
1755         }
1756         kfree(pages);
1757         return res;
1758 }
1759
1760
1761 /* And unmap them... */
1762 static int 
1763 st_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_pages,
1764                     int dirtied)
1765 {
1766         int i;
1767
1768         for (i=0; i < nr_pages; i++) {
1769                 struct page *page = sgl[i].page;
1770
1771                 if (dirtied)
1772                         SetPageDirty(page);
1773                 /* unlock_page(page); */
1774                 /* FIXME: cache flush missing for rw==READ
1775                  * FIXME: call the correct reference counting function
1776                  */
1777                 page_cache_release(page);
1778         }
1779
1780         return 0;
1781 }
1782
1783 /* ^^^^^^^^  above code borrowed from st driver's direct IO ^^^^^^^^^ */
1784 #endif
1785
1786
1787 /* Returns: -ve -> error, 0 -> done, 1 -> try indirect */
1788 static int
1789 sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len)
1790 {
1791 #ifdef SG_ALLOW_DIO_CODE
1792         sg_io_hdr_t *hp = &srp->header;
1793         Sg_scatter_hold *schp = &srp->data;
1794         int sg_tablesize = sfp->parentdp->sg_tablesize;
1795         int mx_sc_elems, res;
1796         struct scsi_device *sdev = sfp->parentdp->device;
1797
1798         if (((unsigned long)hp->dxferp &
1799                         queue_dma_alignment(sdev->request_queue)) != 0)
1800                 return 1;
1801
1802         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1803         if (mx_sc_elems <= 0) {
1804                 return 1;
1805         }
1806         res = st_map_user_pages(schp->buffer, mx_sc_elems,
1807                                 (unsigned long)hp->dxferp, dxfer_len, 
1808                                 (SG_DXFER_TO_DEV == hp->dxfer_direction) ? 1 : 0);
1809         if (res <= 0) {
1810                 sg_remove_scat(schp);
1811                 return 1;
1812         }
1813         schp->k_use_sg = res;
1814         schp->dio_in_use = 1;
1815         hp->info |= SG_INFO_DIRECT_IO;
1816         return 0;
1817 #else
1818         return 1;
1819 #endif
1820 }
1821
1822 static int
1823 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1824 {
1825         struct scatterlist *sg;
1826         int ret_sz = 0, k, rem_sz, num, mx_sc_elems;
1827         int sg_tablesize = sfp->parentdp->sg_tablesize;
1828         int blk_size = buff_size;
1829         struct page *p = NULL;
1830
1831         if ((blk_size < 0) || (!sfp))
1832                 return -EFAULT;
1833         if (0 == blk_size)
1834                 ++blk_size;     /* don't know why */
1835 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1836         blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
1837         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1838                                    buff_size, blk_size));
1839
1840         /* N.B. ret_sz carried into this block ... */
1841         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1842         if (mx_sc_elems < 0)
1843                 return mx_sc_elems;     /* most likely -ENOMEM */
1844
1845         for (k = 0, sg = schp->buffer, rem_sz = blk_size;
1846              (rem_sz > 0) && (k < mx_sc_elems);
1847              ++k, rem_sz -= ret_sz, ++sg) {
1848                 
1849                 num = (rem_sz > SG_SCATTER_SZ) ? SG_SCATTER_SZ : rem_sz;
1850                 p = sg_page_malloc(num, sfp->low_dma, &ret_sz);
1851                 if (!p)
1852                         return -ENOMEM;
1853
1854                 sg->page = p;
1855                 sg->length = ret_sz;
1856
1857                 SCSI_LOG_TIMEOUT(5, printk("sg_build_build: k=%d, a=0x%p, len=%d\n",
1858                                   k, p, ret_sz));
1859         }               /* end of for loop */
1860
1861         schp->k_use_sg = k;
1862         SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, rem_sz=%d\n", k, rem_sz));
1863
1864         schp->bufflen = blk_size;
1865         if (rem_sz > 0) /* must have failed */
1866                 return -ENOMEM;
1867
1868         return 0;
1869 }
1870
1871 static int
1872 sg_write_xfer(Sg_request * srp)
1873 {
1874         sg_io_hdr_t *hp = &srp->header;
1875         Sg_scatter_hold *schp = &srp->data;
1876         struct scatterlist *sg = schp->buffer;
1877         int num_xfer = 0;
1878         int j, k, onum, usglen, ksglen, res;
1879         int iovec_count = (int) hp->iovec_count;
1880         int dxfer_dir = hp->dxfer_direction;
1881         unsigned char *p;
1882         unsigned char __user *up;
1883         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
1884
1885         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_TO_DEV == dxfer_dir) ||
1886             (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
1887                 num_xfer = (int) (new_interface ? hp->dxfer_len : hp->flags);
1888                 if (schp->bufflen < num_xfer)
1889                         num_xfer = schp->bufflen;
1890         }
1891         if ((num_xfer <= 0) || (schp->dio_in_use) ||
1892             (new_interface
1893              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
1894                 return 0;
1895
1896         SCSI_LOG_TIMEOUT(4, printk("sg_write_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
1897                           num_xfer, iovec_count, schp->k_use_sg));
1898         if (iovec_count) {
1899                 onum = iovec_count;
1900                 if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
1901                         return -EFAULT;
1902         } else
1903                 onum = 1;
1904
1905         ksglen = sg->length;
1906         p = page_address(sg->page);
1907         for (j = 0, k = 0; j < onum; ++j) {
1908                 res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
1909                 if (res)
1910                         return res;
1911
1912                 for (; p; ++sg, ksglen = sg->length,
1913                      p = page_address(sg->page)) {
1914                         if (usglen <= 0)
1915                                 break;
1916                         if (ksglen > usglen) {
1917                                 if (usglen >= num_xfer) {
1918                                         if (__copy_from_user(p, up, num_xfer))
1919                                                 return -EFAULT;
1920                                         return 0;
1921                                 }
1922                                 if (__copy_from_user(p, up, usglen))
1923                                         return -EFAULT;
1924                                 p += usglen;
1925                                 ksglen -= usglen;
1926                                 break;
1927                         } else {
1928                                 if (ksglen >= num_xfer) {
1929                                         if (__copy_from_user(p, up, num_xfer))
1930                                                 return -EFAULT;
1931                                         return 0;
1932                                 }
1933                                 if (__copy_from_user(p, up, ksglen))
1934                                         return -EFAULT;
1935                                 up += ksglen;
1936                                 usglen -= ksglen;
1937                         }
1938                         ++k;
1939                         if (k >= schp->k_use_sg)
1940                                 return 0;
1941                 }
1942         }
1943
1944         return 0;
1945 }
1946
1947 static int
1948 sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
1949            int wr_xf, int *countp, unsigned char __user **up)
1950 {
1951         int num_xfer = (int) hp->dxfer_len;
1952         unsigned char __user *p = hp->dxferp;
1953         int count;
1954
1955         if (0 == sg_num) {
1956                 if (wr_xf && ('\0' == hp->interface_id))
1957                         count = (int) hp->flags;        /* holds "old" input_size */
1958                 else
1959                         count = num_xfer;
1960         } else {
1961                 sg_iovec_t iovec;
1962                 if (__copy_from_user(&iovec, p + ind*SZ_SG_IOVEC, SZ_SG_IOVEC))
1963                         return -EFAULT;
1964                 p = iovec.iov_base;
1965                 count = (int) iovec.iov_len;
1966         }
1967         if (!access_ok(wr_xf ? VERIFY_READ : VERIFY_WRITE, p, count))
1968                 return -EFAULT;
1969         if (up)
1970                 *up = p;
1971         if (countp)
1972                 *countp = count;
1973         return 0;
1974 }
1975
1976 static void
1977 sg_remove_scat(Sg_scatter_hold * schp)
1978 {
1979         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1980         if (schp->buffer && (schp->sglist_len > 0)) {
1981                 struct scatterlist *sg = schp->buffer;
1982
1983                 if (schp->dio_in_use) {
1984 #ifdef SG_ALLOW_DIO_CODE
1985                         st_unmap_user_pages(sg, schp->k_use_sg, TRUE);
1986 #endif
1987                 } else {
1988                         int k;
1989
1990                         for (k = 0; (k < schp->k_use_sg) && sg->page;
1991                              ++k, ++sg) {
1992                                 SCSI_LOG_TIMEOUT(5, printk(
1993                                     "sg_remove_scat: k=%d, a=0x%p, len=%d\n",
1994                                     k, sg->page, sg->length));
1995                                 sg_page_free(sg->page, sg->length);
1996                         }
1997                 }
1998                 kfree(schp->buffer);
1999         }
2000         memset(schp, 0, sizeof (*schp));
2001 }
2002
2003 static int
2004 sg_read_xfer(Sg_request * srp)
2005 {
2006         sg_io_hdr_t *hp = &srp->header;
2007         Sg_scatter_hold *schp = &srp->data;
2008         struct scatterlist *sg = schp->buffer;
2009         int num_xfer = 0;
2010         int j, k, onum, usglen, ksglen, res;
2011         int iovec_count = (int) hp->iovec_count;
2012         int dxfer_dir = hp->dxfer_direction;
2013         unsigned char *p;
2014         unsigned char __user *up;
2015         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
2016
2017         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_FROM_DEV == dxfer_dir)
2018             || (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
2019                 num_xfer = hp->dxfer_len;
2020                 if (schp->bufflen < num_xfer)
2021                         num_xfer = schp->bufflen;
2022         }
2023         if ((num_xfer <= 0) || (schp->dio_in_use) ||
2024             (new_interface
2025              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
2026                 return 0;
2027
2028         SCSI_LOG_TIMEOUT(4, printk("sg_read_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
2029                           num_xfer, iovec_count, schp->k_use_sg));
2030         if (iovec_count) {
2031                 onum = iovec_count;
2032                 if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
2033                         return -EFAULT;
2034         } else
2035                 onum = 1;
2036
2037         p = page_address(sg->page);
2038         ksglen = sg->length;
2039         for (j = 0, k = 0; j < onum; ++j) {
2040                 res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
2041                 if (res)
2042                         return res;
2043
2044                 for (; p; ++sg, ksglen = sg->length,
2045                      p = page_address(sg->page)) {
2046                         if (usglen <= 0)
2047                                 break;
2048                         if (ksglen > usglen) {
2049                                 if (usglen >= num_xfer) {
2050                                         if (__copy_to_user(up, p, num_xfer))
2051                                                 return -EFAULT;
2052                                         return 0;
2053                                 }
2054                                 if (__copy_to_user(up, p, usglen))
2055                                         return -EFAULT;
2056                                 p += usglen;
2057                                 ksglen -= usglen;
2058                                 break;
2059                         } else {
2060                                 if (ksglen >= num_xfer) {
2061                                         if (__copy_to_user(up, p, num_xfer))
2062                                                 return -EFAULT;
2063                                         return 0;
2064                                 }
2065                                 if (__copy_to_user(up, p, ksglen))
2066                                         return -EFAULT;
2067                                 up += ksglen;
2068                                 usglen -= ksglen;
2069                         }
2070                         ++k;
2071                         if (k >= schp->k_use_sg)
2072                                 return 0;
2073                 }
2074         }
2075
2076         return 0;
2077 }
2078
2079 static int
2080 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
2081 {
2082         Sg_scatter_hold *schp = &srp->data;
2083         struct scatterlist *sg = schp->buffer;
2084         int k, num;
2085
2086         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
2087                                    num_read_xfer));
2088         if ((!outp) || (num_read_xfer <= 0))
2089                 return 0;
2090
2091         for (k = 0; (k < schp->k_use_sg) && sg->page; ++k, ++sg) {
2092                 num = sg->length;
2093                 if (num > num_read_xfer) {
2094                         if (__copy_to_user(outp, page_address(sg->page),
2095                                            num_read_xfer))
2096                                 return -EFAULT;
2097                         break;
2098                 } else {
2099                         if (__copy_to_user(outp, page_address(sg->page),
2100                                            num))
2101                                 return -EFAULT;
2102                         num_read_xfer -= num;
2103                         if (num_read_xfer <= 0)
2104                                 break;
2105                         outp += num;
2106                 }
2107         }
2108
2109         return 0;
2110 }
2111
2112 static void
2113 sg_build_reserve(Sg_fd * sfp, int req_size)
2114 {
2115         Sg_scatter_hold *schp = &sfp->reserve;
2116
2117         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
2118         do {
2119                 if (req_size < PAGE_SIZE)
2120                         req_size = PAGE_SIZE;
2121                 if (0 == sg_build_indirect(schp, sfp, req_size))
2122                         return;
2123                 else
2124                         sg_remove_scat(schp);
2125                 req_size >>= 1; /* divide by 2 */
2126         } while (req_size > (PAGE_SIZE / 2));
2127 }
2128
2129 static void
2130 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2131 {
2132         Sg_scatter_hold *req_schp = &srp->data;
2133         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2134         struct scatterlist *sg = rsv_schp->buffer;
2135         int k, num, rem;
2136
2137         srp->res_used = 1;
2138         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
2139         rem = size;
2140
2141         for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sg) {
2142                 num = sg->length;
2143                 if (rem <= num) {
2144                         sfp->save_scat_len = num;
2145                         sg->length = rem;
2146                         req_schp->k_use_sg = k + 1;
2147                         req_schp->sglist_len = rsv_schp->sglist_len;
2148                         req_schp->buffer = rsv_schp->buffer;
2149
2150                         req_schp->bufflen = size;
2151                         req_schp->b_malloc_len = rsv_schp->b_malloc_len;
2152                         break;
2153                 } else
2154                         rem -= num;
2155         }
2156
2157         if (k >= rsv_schp->k_use_sg)
2158                 SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
2159 }
2160
2161 static void
2162 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2163 {
2164         Sg_scatter_hold *req_schp = &srp->data;
2165         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2166
2167         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
2168                                    (int) req_schp->k_use_sg));
2169         if ((rsv_schp->k_use_sg > 0) && (req_schp->k_use_sg > 0)) {
2170                 struct scatterlist *sg = rsv_schp->buffer;
2171
2172                 if (sfp->save_scat_len > 0)
2173                         (sg + (req_schp->k_use_sg - 1))->length =
2174                             (unsigned) sfp->save_scat_len;
2175                 else
2176                         SCSI_LOG_TIMEOUT(1, printk ("sg_unlink_reserve: BAD save_scat_len\n"));
2177         }
2178         req_schp->k_use_sg = 0;
2179         req_schp->bufflen = 0;
2180         req_schp->buffer = NULL;
2181         req_schp->sglist_len = 0;
2182         sfp->save_scat_len = 0;
2183         srp->res_used = 0;
2184 }
2185
2186 static Sg_request *
2187 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2188 {
2189         Sg_request *resp;
2190         unsigned long iflags;
2191
2192         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2193         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2194                 /* look for requests that are ready + not SG_IO owned */
2195                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2196                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2197                         resp->done = 2; /* guard against other readers */
2198                         break;
2199                 }
2200         }
2201         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2202         return resp;
2203 }
2204
2205 #ifdef CONFIG_SCSI_PROC_FS
2206 static Sg_request *
2207 sg_get_nth_request(Sg_fd * sfp, int nth)
2208 {
2209         Sg_request *resp;
2210         unsigned long iflags;
2211         int k;
2212
2213         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2214         for (k = 0, resp = sfp->headrp; resp && (k < nth);
2215              ++k, resp = resp->nextrp) ;
2216         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2217         return resp;
2218 }
2219 #endif
2220
2221 /* always adds to end of list */
2222 static Sg_request *
2223 sg_add_request(Sg_fd * sfp)
2224 {
2225         int k;
2226         unsigned long iflags;
2227         Sg_request *resp;
2228         Sg_request *rp = sfp->req_arr;
2229
2230         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2231         resp = sfp->headrp;
2232         if (!resp) {
2233                 memset(rp, 0, sizeof (Sg_request));
2234                 rp->parentfp = sfp;
2235                 resp = rp;
2236                 sfp->headrp = resp;
2237         } else {
2238                 if (0 == sfp->cmd_q)
2239                         resp = NULL;    /* command queuing disallowed */
2240                 else {
2241                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2242                                 if (!rp->parentfp)
2243                                         break;
2244                         }
2245                         if (k < SG_MAX_QUEUE) {
2246                                 memset(rp, 0, sizeof (Sg_request));
2247                                 rp->parentfp = sfp;
2248                                 while (resp->nextrp)
2249                                         resp = resp->nextrp;
2250                                 resp->nextrp = rp;
2251                                 resp = rp;
2252                         } else
2253                                 resp = NULL;
2254                 }
2255         }
2256         if (resp) {
2257                 resp->nextrp = NULL;
2258                 resp->header.duration = jiffies_to_msecs(jiffies);
2259         }
2260         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2261         return resp;
2262 }
2263
2264 /* Return of 1 for found; 0 for not found */
2265 static int
2266 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2267 {
2268         Sg_request *prev_rp;
2269         Sg_request *rp;
2270         unsigned long iflags;
2271         int res = 0;
2272
2273         if ((!sfp) || (!srp) || (!sfp->headrp))
2274                 return res;
2275         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2276         prev_rp = sfp->headrp;
2277         if (srp == prev_rp) {
2278                 sfp->headrp = prev_rp->nextrp;
2279                 prev_rp->parentfp = NULL;
2280                 res = 1;
2281         } else {
2282                 while ((rp = prev_rp->nextrp)) {
2283                         if (srp == rp) {
2284                                 prev_rp->nextrp = rp->nextrp;
2285                                 rp->parentfp = NULL;
2286                                 res = 1;
2287                                 break;
2288                         }
2289                         prev_rp = rp;
2290                 }
2291         }
2292         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2293         return res;
2294 }
2295
2296 #ifdef CONFIG_SCSI_PROC_FS
2297 static Sg_fd *
2298 sg_get_nth_sfp(Sg_device * sdp, int nth)
2299 {
2300         Sg_fd *resp;
2301         unsigned long iflags;
2302         int k;
2303
2304         read_lock_irqsave(&sg_dev_arr_lock, iflags);
2305         for (k = 0, resp = sdp->headfp; resp && (k < nth);
2306              ++k, resp = resp->nextfp) ;
2307         read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2308         return resp;
2309 }
2310 #endif
2311
2312 static Sg_fd *
2313 sg_add_sfp(Sg_device * sdp, int dev)
2314 {
2315         Sg_fd *sfp;
2316         unsigned long iflags;
2317
2318         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2319         if (!sfp)
2320                 return NULL;
2321
2322         init_waitqueue_head(&sfp->read_wait);
2323         rwlock_init(&sfp->rq_list_lock);
2324
2325         sfp->timeout = SG_DEFAULT_TIMEOUT;
2326         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2327         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2328         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2329             sdp->device->host->unchecked_isa_dma : 1;
2330         sfp->cmd_q = SG_DEF_COMMAND_Q;
2331         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2332         sfp->parentdp = sdp;
2333         write_lock_irqsave(&sg_dev_arr_lock, iflags);
2334         if (!sdp->headfp)
2335                 sdp->headfp = sfp;
2336         else {                  /* add to tail of existing list */
2337                 Sg_fd *pfp = sdp->headfp;
2338                 while (pfp->nextfp)
2339                         pfp = pfp->nextfp;
2340                 pfp->nextfp = sfp;
2341         }
2342         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2343         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2344         sg_build_reserve(sfp, sg_big_buff);
2345         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2346                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2347         return sfp;
2348 }
2349
2350 static void
2351 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2352 {
2353         Sg_fd *fp;
2354         Sg_fd *prev_fp;
2355
2356         prev_fp = sdp->headfp;
2357         if (sfp == prev_fp)
2358                 sdp->headfp = prev_fp->nextfp;
2359         else {
2360                 while ((fp = prev_fp->nextfp)) {
2361                         if (sfp == fp) {
2362                                 prev_fp->nextfp = fp->nextfp;
2363                                 break;
2364                         }
2365                         prev_fp = fp;
2366                 }
2367         }
2368         if (sfp->reserve.bufflen > 0) {
2369                 SCSI_LOG_TIMEOUT(6, 
2370                         printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2371                         (int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2372                 sg_remove_scat(&sfp->reserve);
2373         }
2374         sfp->parentdp = NULL;
2375         SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2376         kfree(sfp);
2377 }
2378
2379 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2380 static int
2381 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2382 {
2383         Sg_request *srp;
2384         Sg_request *tsrp;
2385         int dirty = 0;
2386         int res = 0;
2387
2388         for (srp = sfp->headrp; srp; srp = tsrp) {
2389                 tsrp = srp->nextrp;
2390                 if (sg_srp_done(srp, sfp))
2391                         sg_finish_rem_req(srp);
2392                 else
2393                         ++dirty;
2394         }
2395         if (0 == dirty) {
2396                 unsigned long iflags;
2397
2398                 write_lock_irqsave(&sg_dev_arr_lock, iflags);
2399                 __sg_remove_sfp(sdp, sfp);
2400                 if (sdp->detached && (NULL == sdp->headfp)) {
2401                         int k, maxd;
2402
2403                         maxd = sg_dev_max;
2404                         for (k = 0; k < maxd; ++k) {
2405                                 if (sdp == sg_dev_arr[k])
2406                                         break;
2407                         }
2408                         if (k < maxd)
2409                                 sg_dev_arr[k] = NULL;
2410                         kfree((char *) sdp);
2411                         res = 1;
2412                 }
2413                 write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2414         } else {
2415                 /* MOD_INC's to inhibit unloading sg and associated adapter driver */
2416                 /* only bump the access_count if we actually succeeded in
2417                  * throwing another counter on the host module */
2418                 scsi_device_get(sdp->device);   /* XXX: retval ignored? */      
2419                 sfp->closed = 1;        /* flag dirty state on this fd */
2420                 SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2421                                   dirty));
2422         }
2423         return res;
2424 }
2425
2426 static int
2427 sg_res_in_use(Sg_fd * sfp)
2428 {
2429         const Sg_request *srp;
2430         unsigned long iflags;
2431
2432         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2433         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2434                 if (srp->res_used)
2435                         break;
2436         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2437         return srp ? 1 : 0;
2438 }
2439
2440 /* If retSzp==NULL want exact size or fail */
2441 static struct page *
2442 sg_page_malloc(int rqSz, int lowDma, int *retSzp)
2443 {
2444         struct page *resp = NULL;
2445         gfp_t page_mask;
2446         int order, a_size;
2447         int resSz = rqSz;
2448
2449         if (rqSz <= 0)
2450                 return resp;
2451
2452         if (lowDma)
2453                 page_mask = GFP_ATOMIC | GFP_DMA | __GFP_COMP | __GFP_NOWARN;
2454         else
2455                 page_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
2456
2457         for (order = 0, a_size = PAGE_SIZE; a_size < rqSz;
2458              order++, a_size <<= 1) ;
2459         resp = alloc_pages(page_mask, order);
2460         while ((!resp) && order && retSzp) {
2461                 --order;
2462                 a_size >>= 1;   /* divide by 2, until PAGE_SIZE */
2463                 resp =  alloc_pages(page_mask, order);  /* try half */
2464                 resSz = a_size;
2465         }
2466         if (resp) {
2467                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2468                         memset(page_address(resp), 0, resSz);
2469                 if (retSzp)
2470                         *retSzp = resSz;
2471         }
2472         return resp;
2473 }
2474
2475 static void
2476 sg_page_free(struct page *page, int size)
2477 {
2478         int order, a_size;
2479
2480         if (!page)
2481                 return;
2482         for (order = 0, a_size = PAGE_SIZE; a_size < size;
2483              order++, a_size <<= 1) ;
2484         __free_pages(page, order);
2485 }
2486
2487 #ifndef MAINTENANCE_IN_CMD
2488 #define MAINTENANCE_IN_CMD 0xa3
2489 #endif
2490
2491 static unsigned char allow_ops[] = { TEST_UNIT_READY, REQUEST_SENSE,
2492         INQUIRY, READ_CAPACITY, READ_BUFFER, READ_6, READ_10, READ_12,
2493         READ_16, MODE_SENSE, MODE_SENSE_10, LOG_SENSE, REPORT_LUNS,
2494         SERVICE_ACTION_IN, RECEIVE_DIAGNOSTIC, READ_LONG, MAINTENANCE_IN_CMD
2495 };
2496
2497 static int
2498 sg_allow_access(unsigned char opcode, char dev_type)
2499 {
2500         int k;
2501
2502         if (TYPE_SCANNER == dev_type)   /* TYPE_ROM maybe burner */
2503                 return 1;
2504         for (k = 0; k < sizeof (allow_ops); ++k) {
2505                 if (opcode == allow_ops[k])
2506                         return 1;
2507         }
2508         return 0;
2509 }
2510
2511 #ifdef CONFIG_SCSI_PROC_FS
2512 static int
2513 sg_last_dev(void)
2514 {
2515         int k;
2516         unsigned long iflags;
2517
2518         read_lock_irqsave(&sg_dev_arr_lock, iflags);
2519         for (k = sg_dev_max - 1; k >= 0; --k)
2520                 if (sg_dev_arr[k] && sg_dev_arr[k]->device)
2521                         break;
2522         read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2523         return k + 1;           /* origin 1 */
2524 }
2525 #endif
2526
2527 static Sg_device *
2528 sg_get_dev(int dev)
2529 {
2530         Sg_device *sdp = NULL;
2531         unsigned long iflags;
2532
2533         if (sg_dev_arr && (dev >= 0)) {
2534                 read_lock_irqsave(&sg_dev_arr_lock, iflags);
2535                 if (dev < sg_dev_max)
2536                         sdp = sg_dev_arr[dev];
2537                 read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2538         }
2539         return sdp;
2540 }
2541
2542 #ifdef CONFIG_SCSI_PROC_FS
2543
2544 static struct proc_dir_entry *sg_proc_sgp = NULL;
2545
2546 static char sg_proc_sg_dirname[] = "scsi/sg";
2547
2548 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2549
2550 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2551 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2552                                   size_t count, loff_t *off);
2553 static struct file_operations adio_fops = {
2554         /* .owner, .read and .llseek added in sg_proc_init() */
2555         .open = sg_proc_single_open_adio,
2556         .write = sg_proc_write_adio,
2557         .release = single_release,
2558 };
2559
2560 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2561 static ssize_t sg_proc_write_dressz(struct file *filp, 
2562                 const char __user *buffer, size_t count, loff_t *off);
2563 static struct file_operations dressz_fops = {
2564         .open = sg_proc_single_open_dressz,
2565         .write = sg_proc_write_dressz,
2566         .release = single_release,
2567 };
2568
2569 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2570 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2571 static struct file_operations version_fops = {
2572         .open = sg_proc_single_open_version,
2573         .release = single_release,
2574 };
2575
2576 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2577 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2578 static struct file_operations devhdr_fops = {
2579         .open = sg_proc_single_open_devhdr,
2580         .release = single_release,
2581 };
2582
2583 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2584 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2585 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2586 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2587 static void dev_seq_stop(struct seq_file *s, void *v);
2588 static struct file_operations dev_fops = {
2589         .open = sg_proc_open_dev,
2590         .release = seq_release,
2591 };
2592 static struct seq_operations dev_seq_ops = {
2593         .start = dev_seq_start,
2594         .next  = dev_seq_next,
2595         .stop  = dev_seq_stop,
2596         .show  = sg_proc_seq_show_dev,
2597 };
2598
2599 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2600 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2601 static struct file_operations devstrs_fops = {
2602         .open = sg_proc_open_devstrs,
2603         .release = seq_release,
2604 };
2605 static struct seq_operations devstrs_seq_ops = {
2606         .start = dev_seq_start,
2607         .next  = dev_seq_next,
2608         .stop  = dev_seq_stop,
2609         .show  = sg_proc_seq_show_devstrs,
2610 };
2611
2612 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2613 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2614 static struct file_operations debug_fops = {
2615         .open = sg_proc_open_debug,
2616         .release = seq_release,
2617 };
2618 static struct seq_operations debug_seq_ops = {
2619         .start = dev_seq_start,
2620         .next  = dev_seq_next,
2621         .stop  = dev_seq_stop,
2622         .show  = sg_proc_seq_show_debug,
2623 };
2624
2625
2626 struct sg_proc_leaf {
2627         const char * name;
2628         struct file_operations * fops;
2629 };
2630
2631 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2632         {"allow_dio", &adio_fops},
2633         {"debug", &debug_fops},
2634         {"def_reserved_size", &dressz_fops},
2635         {"device_hdr", &devhdr_fops},
2636         {"devices", &dev_fops},
2637         {"device_strs", &devstrs_fops},
2638         {"version", &version_fops}
2639 };
2640
2641 static int
2642 sg_proc_init(void)
2643 {
2644         int k, mask;
2645         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2646         struct proc_dir_entry *pdep;
2647         struct sg_proc_leaf * leaf;
2648
2649         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2650         if (!sg_proc_sgp)
2651                 return 1;
2652         for (k = 0; k < num_leaves; ++k) {
2653                 leaf = &sg_proc_leaf_arr[k];
2654                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2655                 pdep = create_proc_entry(leaf->name, mask, sg_proc_sgp);
2656                 if (pdep) {
2657                         leaf->fops->owner = THIS_MODULE,
2658                         leaf->fops->read = seq_read,
2659                         leaf->fops->llseek = seq_lseek,
2660                         pdep->proc_fops = leaf->fops;
2661                 }
2662         }
2663         return 0;
2664 }
2665
2666 static void
2667 sg_proc_cleanup(void)
2668 {
2669         int k;
2670         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2671
2672         if (!sg_proc_sgp)
2673                 return;
2674         for (k = 0; k < num_leaves; ++k)
2675                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2676         remove_proc_entry(sg_proc_sg_dirname, NULL);
2677 }
2678
2679
2680 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2681 {
2682         seq_printf(s, "%d\n", *((int *)s->private));
2683         return 0;
2684 }
2685
2686 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2687 {
2688         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2689 }
2690
2691 static ssize_t 
2692 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2693                    size_t count, loff_t *off)
2694 {
2695         int num;
2696         char buff[11];
2697
2698         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2699                 return -EACCES;
2700         num = (count < 10) ? count : 10;
2701         if (copy_from_user(buff, buffer, num))
2702                 return -EFAULT;
2703         buff[num] = '\0';
2704         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2705         return count;
2706 }
2707
2708 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2709 {
2710         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2711 }
2712
2713 static ssize_t 
2714 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2715                      size_t count, loff_t *off)
2716 {
2717         int num;
2718         unsigned long k = ULONG_MAX;
2719         char buff[11];
2720
2721         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2722                 return -EACCES;
2723         num = (count < 10) ? count : 10;
2724         if (copy_from_user(buff, buffer, num))
2725                 return -EFAULT;
2726         buff[num] = '\0';
2727         k = simple_strtoul(buff, NULL, 10);
2728         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2729                 sg_big_buff = k;
2730                 return count;
2731         }
2732         return -ERANGE;
2733 }
2734
2735 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2736 {
2737         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2738                    sg_version_date);
2739         return 0;
2740 }
2741
2742 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2743 {
2744         return single_open(file, sg_proc_seq_show_version, NULL);
2745 }
2746
2747 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2748 {
2749         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2750                    "online\n");
2751         return 0;
2752 }
2753
2754 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2755 {
2756         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2757 }
2758
2759 struct sg_proc_deviter {
2760         loff_t  index;
2761         size_t  max;
2762 };
2763
2764 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2765 {
2766         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2767
2768         s->private = it;
2769         if (! it)
2770                 return NULL;
2771
2772         if (NULL == sg_dev_arr)
2773                 return NULL;
2774         it->index = *pos;
2775         it->max = sg_last_dev();
2776         if (it->index >= it->max)
2777                 return NULL;
2778         return it;
2779 }
2780
2781 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2782 {
2783         struct sg_proc_deviter * it = s->private;
2784
2785         *pos = ++it->index;
2786         return (it->index < it->max) ? it : NULL;
2787 }
2788
2789 static void dev_seq_stop(struct seq_file *s, void *v)
2790 {
2791         kfree(s->private);
2792 }
2793
2794 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2795 {
2796         return seq_open(file, &dev_seq_ops);
2797 }
2798
2799 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2800 {
2801         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2802         Sg_device *sdp;
2803         struct scsi_device *scsidp;
2804
2805         sdp = it ? sg_get_dev(it->index) : NULL;
2806         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2807                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2808                               scsidp->host->host_no, scsidp->channel,
2809                               scsidp->id, scsidp->lun, (int) scsidp->type,
2810                               1,
2811                               (int) scsidp->queue_depth,
2812                               (int) scsidp->device_busy,
2813                               (int) scsi_device_online(scsidp));
2814         else
2815                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2816         return 0;
2817 }
2818
2819 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2820 {
2821         return seq_open(file, &devstrs_seq_ops);
2822 }
2823
2824 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2825 {
2826         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2827         Sg_device *sdp;
2828         struct scsi_device *scsidp;
2829
2830         sdp = it ? sg_get_dev(it->index) : NULL;
2831         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2832                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2833                            scsidp->vendor, scsidp->model, scsidp->rev);
2834         else
2835                 seq_printf(s, "<no active device>\n");
2836         return 0;
2837 }
2838
2839 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2840 {
2841         int k, m, new_interface, blen, usg;
2842         Sg_request *srp;
2843         Sg_fd *fp;
2844         const sg_io_hdr_t *hp;
2845         const char * cp;
2846         unsigned int ms;
2847
2848         for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
2849                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2850                            "(res)sgat=%d low_dma=%d\n", k + 1,
2851                            jiffies_to_msecs(fp->timeout),
2852                            fp->reserve.bufflen,
2853                            (int) fp->reserve.k_use_sg,
2854                            (int) fp->low_dma);
2855                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2856                            (int) fp->cmd_q, (int) fp->force_packid,
2857                            (int) fp->keep_orphan, (int) fp->closed);
2858                 for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
2859                         hp = &srp->header;
2860                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2861                         if (srp->res_used) {
2862                                 if (new_interface && 
2863                                     (SG_FLAG_MMAP_IO & hp->flags))
2864                                         cp = "     mmap>> ";
2865                                 else
2866                                         cp = "     rb>> ";
2867                         } else {
2868                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2869                                         cp = "     dio>> ";
2870                                 else
2871                                         cp = "     ";
2872                         }
2873                         seq_printf(s, cp);
2874                         blen = srp->data.bufflen;
2875                         usg = srp->data.k_use_sg;
2876                         seq_printf(s, srp->done ? 
2877                                    ((1 == srp->done) ?  "rcv:" : "fin:")
2878                                    : "act:");
2879                         seq_printf(s, " id=%d blen=%d",
2880                                    srp->header.pack_id, blen);
2881                         if (srp->done)
2882                                 seq_printf(s, " dur=%d", hp->duration);
2883                         else {
2884                                 ms = jiffies_to_msecs(jiffies);
2885                                 seq_printf(s, " t_o/elap=%d/%d",
2886                                         (new_interface ? hp->timeout :
2887                                                   jiffies_to_msecs(fp->timeout)),
2888                                         (ms > hp->duration ? ms - hp->duration : 0));
2889                         }
2890                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2891                                    (int) srp->data.cmd_opcode);
2892                 }
2893                 if (0 == m)
2894                         seq_printf(s, "     No requests active\n");
2895         }
2896 }
2897
2898 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2899 {
2900         return seq_open(file, &debug_seq_ops);
2901 }
2902
2903 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2904 {
2905         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2906         Sg_device *sdp;
2907
2908         if (it && (0 == it->index)) {
2909                 seq_printf(s, "dev_max(currently)=%d max_active_device=%d "
2910                            "(origin 1)\n", sg_dev_max, (int)it->max);
2911                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2912         }
2913         sdp = it ? sg_get_dev(it->index) : NULL;
2914         if (sdp) {
2915                 struct scsi_device *scsidp = sdp->device;
2916
2917                 if (NULL == scsidp) {
2918                         seq_printf(s, "device %d detached ??\n", 
2919                                    (int)it->index);
2920                         return 0;
2921                 }
2922
2923                 if (sg_get_nth_sfp(sdp, 0)) {
2924                         seq_printf(s, " >>> device=%s ",
2925                                 sdp->disk->disk_name);
2926                         if (sdp->detached)
2927                                 seq_printf(s, "detached pending close ");
2928                         else
2929                                 seq_printf
2930                                     (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2931                                      scsidp->host->host_no,
2932                                      scsidp->channel, scsidp->id,
2933                                      scsidp->lun,
2934                                      scsidp->host->hostt->emulated);
2935                         seq_printf(s, " sg_tablesize=%d excl=%d\n",
2936                                    sdp->sg_tablesize, sdp->exclude);
2937                 }
2938                 sg_proc_debug_helper(s, sdp);
2939         }
2940         return 0;
2941 }
2942
2943 #endif                          /* CONFIG_SCSI_PROC_FS */
2944
2945 module_init(init_sg);
2946 module_exit(exit_sg);