1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Mostly platform independent upcall operations to Venus:
4 *  -- upcalls
5 *  -- upcall routines
6 *
7 * Linux 2.0 version
8 * Copyright (C) 1996 Peter J. Braam <braam@maths.ox.ac.uk>,
9 * Michael Callahan <callahan@maths.ox.ac.uk>
10 *
11 * Redone for Linux 2.1
12 * Copyright (C) 1997 Carnegie Mellon University
13 *
14 * Carnegie Mellon University encourages users of this code to contribute
15 * improvements to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>.
16 */
17
18#include <linux/signal.h>
19#include <linux/sched/signal.h>
20#include <linux/types.h>
21#include <linux/kernel.h>
22#include <linux/mm.h>
23#include <linux/time.h>
24#include <linux/fs.h>
25#include <linux/file.h>
26#include <linux/stat.h>
27#include <linux/errno.h>
28#include <linux/string.h>
29#include <linux/slab.h>
30#include <linux/mutex.h>
31#include <linux/uaccess.h>
32#include <linux/vmalloc.h>
33#include <linux/vfs.h>
34
35#include <linux/coda.h>
36#include "coda_psdev.h"
37#include "coda_linux.h"
38#include "coda_cache.h"
39
40#include "coda_int.h"
41
42static int coda_upcall(struct venus_comm *vc, int inSize, int *outSize,
43		       union inputArgs *buffer);
44
45static void *alloc_upcall(int opcode, int size)
46{
47	union inputArgs *inp;
48
49	inp = kvzalloc(size, GFP_KERNEL);
50        if (!inp)
51		return ERR_PTR(-ENOMEM);
52
53        inp->ih.opcode = opcode;
54	inp->ih.pid = task_pid_nr_ns(current, &init_pid_ns);
55	inp->ih.pgid = task_pgrp_nr_ns(current, &init_pid_ns);
56	inp->ih.uid = from_kuid(&init_user_ns, current_fsuid());
57
58	return (void*)inp;
59}
60
61#define UPARG(op)\
62do {\
63	inp = (union inputArgs *)alloc_upcall(op, insize); \
64        if (IS_ERR(inp)) { return PTR_ERR(inp); }\
65        outp = (union outputArgs *)(inp); \
66        outsize = insize; \
67} while (0)
68
69#define INSIZE(tag) sizeof(struct coda_ ## tag ## _in)
70#define OUTSIZE(tag) sizeof(struct coda_ ## tag ## _out)
71#define SIZE(tag)  max_t(unsigned int, INSIZE(tag), OUTSIZE(tag))
72
73
74/* the upcalls */
75int venus_rootfid(struct super_block *sb, struct CodaFid *fidp)
76{
77        union inputArgs *inp;
78        union outputArgs *outp;
79        int insize, outsize, error;
80
81        insize = SIZE(root);
82        UPARG(CODA_ROOT);
83
84	error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
85	if (!error)
86		*fidp = outp->coda_root.VFid;
87
88	kvfree(inp);
89	return error;
90}
91
92int venus_getattr(struct super_block *sb, struct CodaFid *fid,
93		     struct coda_vattr *attr)
94{
95        union inputArgs *inp;
96        union outputArgs *outp;
97        int insize, outsize, error;
98
99        insize = SIZE(getattr);
100	UPARG(CODA_GETATTR);
101        inp->coda_getattr.VFid = *fid;
102
103	error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
104	if (!error)
105		*attr = outp->coda_getattr.attr;
106
107	kvfree(inp);
108        return error;
109}
110
111int venus_setattr(struct super_block *sb, struct CodaFid *fid,
112		  struct coda_vattr *vattr)
113{
114        union inputArgs *inp;
115        union outputArgs *outp;
116        int insize, outsize, error;
117
118	insize = SIZE(setattr);
119	UPARG(CODA_SETATTR);
120
121        inp->coda_setattr.VFid = *fid;
122	inp->coda_setattr.attr = *vattr;
123
124	error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
125
126	kvfree(inp);
127        return error;
128}
129
130int venus_lookup(struct super_block *sb, struct CodaFid *fid,
131		    const char *name, int length, int * type,
132		    struct CodaFid *resfid)
133{
134        union inputArgs *inp;
135        union outputArgs *outp;
136        int insize, outsize, error;
137	int offset;
138
139	offset = INSIZE(lookup);
140        insize = max_t(unsigned int, offset + length +1, OUTSIZE(lookup));
141	UPARG(CODA_LOOKUP);
142
143        inp->coda_lookup.VFid = *fid;
144	inp->coda_lookup.name = offset;
145	inp->coda_lookup.flags = CLU_CASE_SENSITIVE;
146        /* send Venus a null terminated string */
147        memcpy((char *)(inp) + offset, name, length);
148        *((char *)inp + offset + length) = '\0';
149
150	error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
151	if (!error) {
152		*resfid = outp->coda_lookup.VFid;
153		*type = outp->coda_lookup.vtype;
154	}
155
156	kvfree(inp);
157	return error;
158}
159
160int venus_close(struct super_block *sb, struct CodaFid *fid, int flags,
161		kuid_t uid)
162{
163	union inputArgs *inp;
164	union outputArgs *outp;
165	int insize, outsize, error;
166
167	insize = SIZE(release);
168	UPARG(CODA_CLOSE);
169
170	inp->ih.uid = from_kuid(&init_user_ns, uid);
171        inp->coda_close.VFid = *fid;
172        inp->coda_close.flags = flags;
173
174	error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
175
176	kvfree(inp);
177        return error;
178}
179
180int venus_open(struct super_block *sb, struct CodaFid *fid,
181		  int flags, struct file **fh)
182{
183        union inputArgs *inp;
184        union outputArgs *outp;
185        int insize, outsize, error;
186
187	insize = SIZE(open_by_fd);
188	UPARG(CODA_OPEN_BY_FD);
189
190	inp->coda_open_by_fd.VFid = *fid;
191	inp->coda_open_by_fd.flags = flags;
192
193	error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
194	if (!error)
195		*fh = outp->coda_open_by_fd.fh;
196
197	kvfree(inp);
198	return error;
199}
200
201int venus_mkdir(struct super_block *sb, struct CodaFid *dirfid,
202		   const char *name, int length,
203		   struct CodaFid *newfid, struct coda_vattr *attrs)
204{
205        union inputArgs *inp;
206        union outputArgs *outp;
207        int insize, outsize, error;
208        int offset;
209
210	offset = INSIZE(mkdir);
211	insize = max_t(unsigned int, offset + length + 1, OUTSIZE(mkdir));
212	UPARG(CODA_MKDIR);
213
214        inp->coda_mkdir.VFid = *dirfid;
215        inp->coda_mkdir.attr = *attrs;
216	inp->coda_mkdir.name = offset;
217        /* Venus must get null terminated string */
218        memcpy((char *)(inp) + offset, name, length);
219        *((char *)inp + offset + length) = '\0';
220
221	error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
222	if (!error) {
223		*attrs = outp->coda_mkdir.attr;
224		*newfid = outp->coda_mkdir.VFid;
225	}
226
227	kvfree(inp);
228	return error;
229}
230
231
232int venus_rename(struct super_block *sb, struct CodaFid *old_fid,
233		 struct CodaFid *new_fid, size_t old_length,
234		 size_t new_length, const char *old_name,
235		 const char *new_name)
236{
237	union inputArgs *inp;
238        union outputArgs *outp;
239        int insize, outsize, error;
240	int offset, s;
241
242	offset = INSIZE(rename);
243	insize = max_t(unsigned int, offset + new_length + old_length + 8,
244		     OUTSIZE(rename));
245 	UPARG(CODA_RENAME);
246
247        inp->coda_rename.sourceFid = *old_fid;
248        inp->coda_rename.destFid =  *new_fid;
249        inp->coda_rename.srcname = offset;
250
251        /* Venus must receive an null terminated string */
252        s = ( old_length & ~0x3) +4; /* round up to word boundary */
253        memcpy((char *)(inp) + offset, old_name, old_length);
254        *((char *)inp + offset + old_length) = '\0';
255
256        /* another null terminated string for Venus */
257        offset += s;
258        inp->coda_rename.destname = offset;
259        s = ( new_length & ~0x3) +4; /* round up to word boundary */
260        memcpy((char *)(inp) + offset, new_name, new_length);
261        *((char *)inp + offset + new_length) = '\0';
262
263	error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
264
265	kvfree(inp);
266	return error;
267}
268
269int venus_create(struct super_block *sb, struct CodaFid *dirfid,
270		 const char *name, int length, int excl, int mode,
271		 struct CodaFid *newfid, struct coda_vattr *attrs)
272{
273        union inputArgs *inp;
274        union outputArgs *outp;
275        int insize, outsize, error;
276        int offset;
277
278        offset = INSIZE(create);
279	insize = max_t(unsigned int, offset + length + 1, OUTSIZE(create));
280	UPARG(CODA_CREATE);
281
282        inp->coda_create.VFid = *dirfid;
283        inp->coda_create.attr.va_mode = mode;
284	inp->coda_create.excl = excl;
285        inp->coda_create.mode = mode;
286        inp->coda_create.name = offset;
287
288        /* Venus must get null terminated string */
289        memcpy((char *)(inp) + offset, name, length);
290        *((char *)inp + offset + length) = '\0';
291
292	error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
293	if (!error) {
294		*attrs = outp->coda_create.attr;
295		*newfid = outp->coda_create.VFid;
296	}
297
298	kvfree(inp);
299	return error;
300}
301
302int venus_rmdir(struct super_block *sb, struct CodaFid *dirfid,
303		    const char *name, int length)
304{
305        union inputArgs *inp;
306        union outputArgs *outp;
307        int insize, outsize, error;
308        int offset;
309
310        offset = INSIZE(rmdir);
311	insize = max_t(unsigned int, offset + length + 1, OUTSIZE(rmdir));
312	UPARG(CODA_RMDIR);
313
314        inp->coda_rmdir.VFid = *dirfid;
315        inp->coda_rmdir.name = offset;
316        memcpy((char *)(inp) + offset, name, length);
317	*((char *)inp + offset + length) = '\0';
318
319	error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
320
321	kvfree(inp);
322	return error;
323}
324
325int venus_remove(struct super_block *sb, struct CodaFid *dirfid,
326		    const char *name, int length)
327{
328        union inputArgs *inp;
329        union outputArgs *outp;
330        int error=0, insize, outsize, offset;
331
332        offset = INSIZE(remove);
333	insize = max_t(unsigned int, offset + length + 1, OUTSIZE(remove));
334	UPARG(CODA_REMOVE);
335
336        inp->coda_remove.VFid = *dirfid;
337        inp->coda_remove.name = offset;
338        memcpy((char *)(inp) + offset, name, length);
339	*((char *)inp + offset + length) = '\0';
340
341	error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
342
343	kvfree(inp);
344	return error;
345}
346
347int venus_readlink(struct super_block *sb, struct CodaFid *fid,
348		      char *buffer, int *length)
349{
350        union inputArgs *inp;
351        union outputArgs *outp;
352        int insize, outsize, error;
353        int retlen;
354        char *result;
355
356	insize = max_t(unsigned int,
357		     INSIZE(readlink), OUTSIZE(readlink)+ *length);
358	UPARG(CODA_READLINK);
359
360        inp->coda_readlink.VFid = *fid;
361
362	error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
363	if (!error) {
364		retlen = outp->coda_readlink.count;
365		if (retlen >= *length)
366			retlen = *length - 1;
367		*length = retlen;
368		result =  (char *)outp + (long)outp->coda_readlink.data;
369		memcpy(buffer, result, retlen);
370		*(buffer + retlen) = '\0';
371	}
372
373	kvfree(inp);
374        return error;
375}
376
377
378
379int venus_link(struct super_block *sb, struct CodaFid *fid,
380		  struct CodaFid *dirfid, const char *name, int len )
381{
382        union inputArgs *inp;
383        union outputArgs *outp;
384        int insize, outsize, error;
385        int offset;
386
387	offset = INSIZE(link);
388	insize = max_t(unsigned int, offset  + len + 1, OUTSIZE(link));
389        UPARG(CODA_LINK);
390
391        inp->coda_link.sourceFid = *fid;
392        inp->coda_link.destFid = *dirfid;
393        inp->coda_link.tname = offset;
394
395        /* make sure strings are null terminated */
396        memcpy((char *)(inp) + offset, name, len);
397        *((char *)inp + offset + len) = '\0';
398
399	error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
400
401	kvfree(inp);
402        return error;
403}
404
405int venus_symlink(struct super_block *sb, struct CodaFid *fid,
406		     const char *name, int len,
407		     const char *symname, int symlen)
408{
409        union inputArgs *inp;
410        union outputArgs *outp;
411        int insize, outsize, error;
412        int offset, s;
413
414        offset = INSIZE(symlink);
415	insize = max_t(unsigned int, offset + len + symlen + 8, OUTSIZE(symlink));
416	UPARG(CODA_SYMLINK);
417
418        /*        inp->coda_symlink.attr = *tva; XXXXXX */
419        inp->coda_symlink.VFid = *fid;
420
421	/* Round up to word boundary and null terminate */
422        inp->coda_symlink.srcname = offset;
423        s = ( symlen  & ~0x3 ) + 4;
424        memcpy((char *)(inp) + offset, symname, symlen);
425        *((char *)inp + offset + symlen) = '\0';
426
427	/* Round up to word boundary and null terminate */
428        offset += s;
429        inp->coda_symlink.tname = offset;
430        s = (len & ~0x3) + 4;
431        memcpy((char *)(inp) + offset, name, len);
432        *((char *)inp + offset + len) = '\0';
433
434	error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
435
436	kvfree(inp);
437        return error;
438}
439
440int venus_fsync(struct super_block *sb, struct CodaFid *fid)
441{
442        union inputArgs *inp;
443        union outputArgs *outp;
444	int insize, outsize, error;
445
446	insize=SIZE(fsync);
447	UPARG(CODA_FSYNC);
448
449	inp->coda_fsync.VFid = *fid;
450	error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
451
452	kvfree(inp);
453	return error;
454}
455
456int venus_access(struct super_block *sb, struct CodaFid *fid, int mask)
457{
458        union inputArgs *inp;
459        union outputArgs *outp;
460	int insize, outsize, error;
461
462	insize = SIZE(access);
463	UPARG(CODA_ACCESS);
464
465        inp->coda_access.VFid = *fid;
466        inp->coda_access.flags = mask;
467
468	error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
469
470	kvfree(inp);
471	return error;
472}
473
474
475int venus_pioctl(struct super_block *sb, struct CodaFid *fid,
476		 unsigned int cmd, struct PioctlData *data)
477{
478        union inputArgs *inp;
479        union outputArgs *outp;
480	int insize, outsize, error;
481	int iocsize;
482
483	insize = VC_MAXMSGSIZE;
484	UPARG(CODA_IOCTL);
485
486        /* build packet for Venus */
487        if (data->vi.in_size > VC_MAXDATASIZE) {
488		error = -EINVAL;
489		goto exit;
490        }
491
492        if (data->vi.out_size > VC_MAXDATASIZE) {
493		error = -EINVAL;
494		goto exit;
495	}
496
497        inp->coda_ioctl.VFid = *fid;
498
499        /* the cmd field was mutated by increasing its size field to
500         * reflect the path and follow args. We need to subtract that
501         * out before sending the command to Venus.  */
502        inp->coda_ioctl.cmd = (cmd & ~(PIOCPARM_MASK << 16));
503        iocsize = ((cmd >> 16) & PIOCPARM_MASK) - sizeof(char *) - sizeof(int);
504        inp->coda_ioctl.cmd |= (iocsize & PIOCPARM_MASK) <<	16;
505
506        /* in->coda_ioctl.rwflag = flag; */
507        inp->coda_ioctl.len = data->vi.in_size;
508        inp->coda_ioctl.data = (char *)(INSIZE(ioctl));
509
510        /* get the data out of user space */
511	if (copy_from_user((char *)inp + (long)inp->coda_ioctl.data,
512			   data->vi.in, data->vi.in_size)) {
513		error = -EINVAL;
514	        goto exit;
515	}
516
517	error = coda_upcall(coda_vcp(sb), SIZE(ioctl) + data->vi.in_size,
518			    &outsize, inp);
519
520        if (error) {
521		pr_warn("%s: Venus returns: %d for %s\n",
522			__func__, error, coda_f2s(fid));
523		goto exit;
524	}
525
526	if (outsize < (long)outp->coda_ioctl.data + outp->coda_ioctl.len) {
527		error = -EINVAL;
528		goto exit;
529	}
530
531	/* Copy out the OUT buffer. */
532        if (outp->coda_ioctl.len > data->vi.out_size) {
533		error = -EINVAL;
534		goto exit;
535        }
536
537	/* Copy out the OUT buffer. */
538	if (copy_to_user(data->vi.out,
539			 (char *)outp + (long)outp->coda_ioctl.data,
540			 outp->coda_ioctl.len)) {
541		error = -EFAULT;
542		goto exit;
543	}
544
545 exit:
546	kvfree(inp);
547	return error;
548}
549
550int venus_statfs(struct dentry *dentry, struct kstatfs *sfs)
551{
552        union inputArgs *inp;
553        union outputArgs *outp;
554        int insize, outsize, error;
555
556	insize = SIZE(statfs);
557	UPARG(CODA_STATFS);
558
559	error = coda_upcall(coda_vcp(dentry->d_sb), insize, &outsize, inp);
560	if (!error) {
561		sfs->f_blocks = outp->coda_statfs.stat.f_blocks;
562		sfs->f_bfree  = outp->coda_statfs.stat.f_bfree;
563		sfs->f_bavail = outp->coda_statfs.stat.f_bavail;
564		sfs->f_files  = outp->coda_statfs.stat.f_files;
565		sfs->f_ffree  = outp->coda_statfs.stat.f_ffree;
566	}
567
568	kvfree(inp);
569        return error;
570}
571
572int venus_access_intent(struct super_block *sb, struct CodaFid *fid,
573			bool *access_intent_supported,
574			size_t count, loff_t ppos, int type)
575{
576	union inputArgs *inp;
577	union outputArgs *outp;
578	int insize, outsize, error;
579	bool finalizer =
580		type == CODA_ACCESS_TYPE_READ_FINISH ||
581		type == CODA_ACCESS_TYPE_WRITE_FINISH;
582
583	if (!*access_intent_supported && !finalizer)
584		return 0;
585
586	insize = SIZE(access_intent);
587	UPARG(CODA_ACCESS_INTENT);
588
589	inp->coda_access_intent.VFid = *fid;
590	inp->coda_access_intent.count = count;
591	inp->coda_access_intent.pos = ppos;
592	inp->coda_access_intent.type = type;
593
594	error = coda_upcall(coda_vcp(sb), insize,
595			    finalizer ? NULL : &outsize, inp);
596
597	/*
598	 * we have to free the request buffer for synchronous upcalls
599	 * or when asynchronous upcalls fail, but not when asynchronous
600	 * upcalls succeed
601	 */
602	if (!finalizer || error)
603		kvfree(inp);
604
605	/* Chunked access is not supported or an old Coda client */
606	if (error == -EOPNOTSUPP) {
607		*access_intent_supported = false;
608		error = 0;
609	}
610	return error;
611}
612
613/*
614 * coda_upcall and coda_downcall routines.
615 */
616static void coda_block_signals(sigset_t *old)
617{
618	spin_lock_irq(&current->sighand->siglock);
619	*old = current->blocked;
620
621	sigfillset(&current->blocked);
622	sigdelset(&current->blocked, SIGKILL);
623	sigdelset(&current->blocked, SIGSTOP);
624	sigdelset(&current->blocked, SIGINT);
625
626	recalc_sigpending();
627	spin_unlock_irq(&current->sighand->siglock);
628}
629
630static void coda_unblock_signals(sigset_t *old)
631{
632	spin_lock_irq(&current->sighand->siglock);
633	current->blocked = *old;
634	recalc_sigpending();
635	spin_unlock_irq(&current->sighand->siglock);
636}
637
638/* Don't allow signals to interrupt the following upcalls before venus
639 * has seen them,
640 * - CODA_CLOSE or CODA_RELEASE upcall  (to avoid reference count problems)
641 * - CODA_STORE				(to avoid data loss)
642 * - CODA_ACCESS_INTENT                 (to avoid reference count problems)
643 */
644#define CODA_INTERRUPTIBLE(r) (!coda_hard && \
645			       (((r)->uc_opcode != CODA_CLOSE && \
646				 (r)->uc_opcode != CODA_STORE && \
647				 (r)->uc_opcode != CODA_ACCESS_INTENT && \
648				 (r)->uc_opcode != CODA_RELEASE) || \
649				(r)->uc_flags & CODA_REQ_READ))
650
651static inline void coda_waitfor_upcall(struct venus_comm *vcp,
652				       struct upc_req *req)
653{
654	DECLARE_WAITQUEUE(wait, current);
655	unsigned long timeout = jiffies + coda_timeout * HZ;
656	sigset_t old;
657	int blocked;
658
659	coda_block_signals(&old);
660	blocked = 1;
661
662	add_wait_queue(&req->uc_sleep, &wait);
663	for (;;) {
664		if (CODA_INTERRUPTIBLE(req))
665			set_current_state(TASK_INTERRUPTIBLE);
666		else
667			set_current_state(TASK_UNINTERRUPTIBLE);
668
669		/* got a reply */
670		if (req->uc_flags & (CODA_REQ_WRITE | CODA_REQ_ABORT))
671			break;
672
673		if (blocked && time_after(jiffies, timeout) &&
674		    CODA_INTERRUPTIBLE(req))
675		{
676			coda_unblock_signals(&old);
677			blocked = 0;
678		}
679
680		if (signal_pending(current)) {
681			list_del(&req->uc_chain);
682			break;
683		}
684
685		mutex_unlock(&vcp->vc_mutex);
686		if (blocked)
687			schedule_timeout(HZ);
688		else
689			schedule();
690		mutex_lock(&vcp->vc_mutex);
691	}
692	if (blocked)
693		coda_unblock_signals(&old);
694
695	remove_wait_queue(&req->uc_sleep, &wait);
696	set_current_state(TASK_RUNNING);
697}
698
699
700/*
701 * coda_upcall will return an error in the case of
702 * failed communication with Venus _or_ will peek at Venus
703 * reply and return Venus' error.
704 *
705 * As venus has 2 types of errors, normal errors (positive) and internal
706 * errors (negative), normal errors are negated, while internal errors
707 * are all mapped to -EINTR, while showing a nice warning message. (jh)
708 */
709static int coda_upcall(struct venus_comm *vcp,
710		       int inSize, int *outSize,
711		       union inputArgs *buffer)
712{
713	union outputArgs *out;
714	union inputArgs *sig_inputArgs;
715	struct upc_req *req = NULL, *sig_req;
716	int error;
717
718	mutex_lock(&vcp->vc_mutex);
719
720	if (!vcp->vc_inuse) {
721		pr_notice("Venus dead, not sending upcall\n");
722		error = -ENXIO;
723		goto exit;
724	}
725
726	/* Format the request message. */
727	req = kmalloc(sizeof(struct upc_req), GFP_KERNEL);
728	if (!req) {
729		error = -ENOMEM;
730		goto exit;
731	}
732
733	buffer->ih.unique = ++vcp->vc_seq;
734
735	req->uc_data = (void *)buffer;
736	req->uc_flags = outSize ? 0 : CODA_REQ_ASYNC;
737	req->uc_inSize = inSize;
738	req->uc_outSize = (outSize && *outSize) ? *outSize : inSize;
739	req->uc_opcode = buffer->ih.opcode;
740	req->uc_unique = buffer->ih.unique;
741	init_waitqueue_head(&req->uc_sleep);
742
743	/* Append msg to pending queue and poke Venus. */
744	list_add_tail(&req->uc_chain, &vcp->vc_pending);
745	wake_up_interruptible(&vcp->vc_waitq);
746
747	/* We can return early on asynchronous requests */
748	if (outSize == NULL) {
749		mutex_unlock(&vcp->vc_mutex);
750		return 0;
751	}
752
753	/* We can be interrupted while we wait for Venus to process
754	 * our request.  If the interrupt occurs before Venus has read
755	 * the request, we dequeue and return. If it occurs after the
756	 * read but before the reply, we dequeue, send a signal
757	 * message, and return. If it occurs after the reply we ignore
758	 * it. In no case do we want to restart the syscall.  If it
759	 * was interrupted by a venus shutdown (psdev_close), return
760	 * ENODEV.  */
761
762	/* Go to sleep.  Wake up on signals only after the timeout. */
763	coda_waitfor_upcall(vcp, req);
764
765	/* Op went through, interrupt or not... */
766	if (req->uc_flags & CODA_REQ_WRITE) {
767		out = (union outputArgs *)req->uc_data;
768		/* here we map positive Venus errors to kernel errors */
769		error = -out->oh.result;
770		*outSize = req->uc_outSize;
771		goto exit;
772	}
773
774	error = -EINTR;
775	if ((req->uc_flags & CODA_REQ_ABORT) || !signal_pending(current)) {
776		pr_warn("Unexpected interruption.\n");
777		goto exit;
778	}
779
780	/* Interrupted before venus read it. */
781	if (!(req->uc_flags & CODA_REQ_READ))
782		goto exit;
783
784	/* Venus saw the upcall, make sure we can send interrupt signal */
785	if (!vcp->vc_inuse) {
786		pr_info("Venus dead, not sending signal.\n");
787		goto exit;
788	}
789
790	error = -ENOMEM;
791	sig_req = kmalloc(sizeof(struct upc_req), GFP_KERNEL);
792	if (!sig_req) goto exit;
793
794	sig_inputArgs = kvzalloc(sizeof(*sig_inputArgs), GFP_KERNEL);
795	if (!sig_inputArgs) {
796		kfree(sig_req);
797		goto exit;
798	}
799
800	error = -EINTR;
801	sig_inputArgs->ih.opcode = CODA_SIGNAL;
802	sig_inputArgs->ih.unique = req->uc_unique;
803
804	sig_req->uc_flags = CODA_REQ_ASYNC;
805	sig_req->uc_opcode = sig_inputArgs->ih.opcode;
806	sig_req->uc_unique = sig_inputArgs->ih.unique;
807	sig_req->uc_data = (void *)sig_inputArgs;
808	sig_req->uc_inSize = sizeof(struct coda_in_hdr);
809	sig_req->uc_outSize = sizeof(struct coda_in_hdr);
810
811	/* insert at head of queue! */
812	list_add(&(sig_req->uc_chain), &vcp->vc_pending);
813	wake_up_interruptible(&vcp->vc_waitq);
814
815exit:
816	kfree(req);
817	mutex_unlock(&vcp->vc_mutex);
818	return error;
819}
820
821/*
822    The statements below are part of the Coda opportunistic
823    programming -- taken from the Mach/BSD kernel code for Coda.
824    You don't get correct semantics by stating what needs to be
825    done without guaranteeing the invariants needed for it to happen.
826    When will be have time to find out what exactly is going on?  (pjb)
827*/
828
829
830/*
831 * There are 7 cases where cache invalidations occur.  The semantics
832 *  of each is listed here:
833 *
834 * CODA_FLUSH     -- flush all entries from the name cache and the cnode cache.
835 * CODA_PURGEUSER -- flush all entries from the name cache for a specific user
836 *                  This call is a result of token expiration.
837 *
838 * The next arise as the result of callbacks on a file or directory.
839 * CODA_ZAPFILE   -- flush the cached attributes for a file.
840
841 * CODA_ZAPDIR    -- flush the attributes for the dir and
842 *                  force a new lookup for all the children
843                    of this dir.
844
845 *
846 * The next is a result of Venus detecting an inconsistent file.
847 * CODA_PURGEFID  -- flush the attribute for the file
848 *                  purge it and its children from the dcache
849 *
850 * The last  allows Venus to replace local fids with global ones
851 * during reintegration.
852 *
853 * CODA_REPLACE -- replace one CodaFid with another throughout the name cache */
854
855int coda_downcall(struct venus_comm *vcp, int opcode, union outputArgs *out,
856		  size_t nbytes)
857{
858	struct inode *inode = NULL;
859	struct CodaFid *fid = NULL, *newfid;
860	struct super_block *sb;
861
862	/*
863	 * Make sure we have received enough data from the cache
864	 * manager to populate the necessary fields in the buffer
865	 */
866	switch (opcode) {
867	case CODA_PURGEUSER:
868		if (nbytes < sizeof(struct coda_purgeuser_out))
869			return -EINVAL;
870		break;
871
872	case CODA_ZAPDIR:
873		if (nbytes < sizeof(struct coda_zapdir_out))
874			return -EINVAL;
875		break;
876
877	case CODA_ZAPFILE:
878		if (nbytes < sizeof(struct coda_zapfile_out))
879			return -EINVAL;
880		break;
881
882	case CODA_PURGEFID:
883		if (nbytes < sizeof(struct coda_purgefid_out))
884			return -EINVAL;
885		break;
886
887	case CODA_REPLACE:
888		if (nbytes < sizeof(struct coda_replace_out))
889			return -EINVAL;
890		break;
891	}
892
893	/* Handle invalidation requests. */
894	mutex_lock(&vcp->vc_mutex);
895	sb = vcp->vc_sb;
896	if (!sb || !sb->s_root)
897		goto unlock_out;
898
899	switch (opcode) {
900	case CODA_FLUSH:
901		coda_cache_clear_all(sb);
902		shrink_dcache_sb(sb);
903		if (d_really_is_positive(sb->s_root))
904			coda_flag_inode(d_inode(sb->s_root), C_FLUSH);
905		break;
906
907	case CODA_PURGEUSER:
908		coda_cache_clear_all(sb);
909		break;
910
911	case CODA_ZAPDIR:
912		fid = &out->coda_zapdir.CodaFid;
913		break;
914
915	case CODA_ZAPFILE:
916		fid = &out->coda_zapfile.CodaFid;
917		break;
918
919	case CODA_PURGEFID:
920		fid = &out->coda_purgefid.CodaFid;
921		break;
922
923	case CODA_REPLACE:
924		fid = &out->coda_replace.OldFid;
925		break;
926	}
927	if (fid)
928		inode = coda_fid_to_inode(fid, sb);
929
930unlock_out:
931	mutex_unlock(&vcp->vc_mutex);
932
933	if (!inode)
934		return 0;
935
936	switch (opcode) {
937	case CODA_ZAPDIR:
938		coda_flag_inode_children(inode, C_PURGE);
939		coda_flag_inode(inode, C_VATTR);
940		break;
941
942	case CODA_ZAPFILE:
943		coda_flag_inode(inode, C_VATTR);
944		break;
945
946	case CODA_PURGEFID:
947		coda_flag_inode_children(inode, C_PURGE);
948
949		/* catch the dentries later if some are still busy */
950		coda_flag_inode(inode, C_PURGE);
951		d_prune_aliases(inode);
952		break;
953
954	case CODA_REPLACE:
955		newfid = &out->coda_replace.NewFid;
956		coda_replace_fid(inode, fid, newfid);
957		break;
958	}
959	iput(inode);
960	return 0;
961}
962