summaryrefslogtreecommitdiffstats
path: root/libglusterfs/src/stack.h
blob: 212a649d42ed590a35a088aa914886f7095b7024 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
/*
  Copyright (c) 2008-2012 Red Hat, Inc. <http://www.redhat.com>
  This file is part of GlusterFS.

  This file is licensed to you under your choice of the GNU Lesser
  General Public License, version 3 or any later version (LGPLv3 or
  later), or the GNU General Public License, version 2 (GPLv2), in all
  cases as published by the Free Software Foundation.
*/

/*
  This file defines MACROS and static inlines used to emulate a function
  call over asynchronous communication with remote server
*/

#ifndef _STACK_H
#define _STACK_H

struct _call_stack;
typedef struct _call_stack call_stack_t;
struct _call_frame;
typedef struct _call_frame call_frame_t;
struct call_pool;
typedef struct call_pool call_pool_t;

#include <sys/time.h>

#include "xlator.h"
#include "dict.h"
#include "list.h"
#include "common-utils.h"
#include "lkowner.h"
#include "client_t.h"
#include "libglusterfs-messages.h"
#include "timespec.h"

#define NFS_PID 1
#define LOW_PRIO_PROC_PID -1

#define STACK_ERR_XL_NAME(stack) (stack->err_xl?stack->err_xl->name:"-")
#define STACK_CLIENT_NAME(stack) (stack->client?stack->client->client_uid:"-")

typedef int32_t (*ret_fn_t) (call_frame_t *frame,
                             call_frame_t *prev_frame,
                             xlator_t *this,
                             int32_t op_ret,
                             int32_t op_errno,
                             ...);

struct call_pool {
        union {
                struct list_head   all_frames;
                struct {
                        call_stack_t *next_call;
                        call_stack_t *prev_call;
                } all_stacks;
        };
        int64_t                     cnt;
        gf_atomic_t                 total_count;
        gf_lock_t                   lock;
        struct mem_pool             *frame_mem_pool;
        struct mem_pool             *stack_mem_pool;
};

struct _call_frame {
        call_stack_t *root;        /* stack root */
        call_frame_t *parent;      /* previous BP */
        struct list_head frames;
        void         *local;       /* local variables */
        xlator_t     *this;        /* implicit object */
        ret_fn_t      ret;         /* op_return address */
        int32_t       ref_count;
        gf_lock_t     lock;
        void         *cookie;      /* unique cookie */
        gf_boolean_t  complete;

        glusterfs_fop_t  op;
        struct timespec  begin;      /* when this frame was created */
        struct timespec  end;        /* when this frame completed */
        const char      *wind_from;
        const char      *wind_to;
        const char      *unwind_from;
        const char      *unwind_to;
};

struct _ns_info {
        uint32_t     hash;  /* Hash of the namespace from SuperFastHash */
        gf_boolean_t found; /* Set to true if we found a namespace */
};

typedef struct _ns_info ns_info_t;

#define SMALL_GROUP_COUNT 128

struct _call_stack {
        union {
                struct list_head      all_frames;
                struct {
                        call_stack_t *next_call;
                        call_stack_t *prev_call;
                };
        };
        call_pool_t                  *pool;
        gf_lock_t                     stack_lock;
        client_t                     *client;
        uint64_t                      unique;
        void                         *state;  /* pointer to request state */
        uid_t                         uid;
        gid_t                         gid;
        pid_t                         pid;
        char                          identifier[UNIX_PATH_MAX];
        uint16_t                      ngrps;
        uint32_t                      groups_small[SMALL_GROUP_COUNT];
	uint32_t                     *groups_large;
	uint32_t                     *groups;
        gf_lkowner_t                  lk_owner;
        glusterfs_ctx_t              *ctx;

        struct list_head              myframes; /* List of call_frame_t that go
                                                   to make the call stack */

        int32_t                       op;
        int8_t                        type;
        struct timespec               tv;
        xlator_t                     *err_xl;
        int32_t                       error;

        uint32_t flags; /* use it wisely, think of it as a mechanism to
                           send information over the wire too */
        struct timespec ctime; /* timestamp, most probably set at
                                  creation of stack. */

        ns_info_t                     ns_info;
};


/* call_stack flags field users */
#define MDATA_CTIME (1<<0)
#define MDATA_MTIME (1<<1)
#define MDATA_ATIME (1<<2)
#define MDATA_PAR_CTIME (1<<3)
#define MDATA_PAR_MTIME (1<<4)
#define MDATA_PAR_ATIME (1<<5)

#define frame_set_uid_gid(frm, u, g)            \
        do {                                    \
                if (frm) {                      \
                        (frm)->root->uid = u;   \
                        (frm)->root->gid = g;   \
                        (frm)->root->ngrps = 0; \
                }                               \
        } while (0);                            \


struct xlator_fops;
void gf_update_latency (call_frame_t *frame);


static inline void
FRAME_DESTROY (call_frame_t *frame)
{
        void *local = NULL;

        if (frame->root->ctx->measure_latency)
                gf_update_latency (frame);

        list_del_init (&frame->frames);
        if (frame->local) {
                local = frame->local;
                frame->local = NULL;

        }

        LOCK_DESTROY (&frame->lock);
        mem_put (frame);

        if (local)
                mem_put (local);
}


static inline void
STACK_DESTROY (call_stack_t *stack)
{
        call_frame_t *frame = NULL;
        call_frame_t *tmp = NULL;

        LOCK (&stack->pool->lock);
        {
                list_del_init (&stack->all_frames);
                stack->pool->cnt--;
        }
        UNLOCK (&stack->pool->lock);

        LOCK_DESTROY (&stack->stack_lock);

        list_for_each_entry_safe (frame, tmp, &stack->myframes, frames) {
                FRAME_DESTROY (frame);
        }

	GF_FREE (stack->groups_large);

        mem_put (stack);
}

static inline void
STACK_RESET (call_stack_t *stack)
{
        call_frame_t *frame = NULL;
        call_frame_t *tmp = NULL;
        call_frame_t *last = NULL;
        struct list_head toreset = {0};

        INIT_LIST_HEAD (&toreset);

        /* We acquire call_pool->lock only to remove the frames from this stack
         * to preserve atomicity. This synchronizes across concurrent requests
         * like statedump, STACK_DESTROY etc. */

        LOCK (&stack->pool->lock);
        {
                last = list_last_entry (&stack->myframes, call_frame_t, frames);
                list_del_init (&last->frames);
                list_splice_init (&stack->myframes, &toreset);
                list_add (&last->frames, &stack->myframes);
        }
        UNLOCK (&stack->pool->lock);

        list_for_each_entry_safe (frame, tmp, &toreset, frames) {
                FRAME_DESTROY (frame);
        }
}

#define FRAME_SU_DO(frm, local_type)                                   \
        do {                                                           \
                local_type *__local = (frm)->local;                    \
                __local->uid = frm->root->uid;                         \
                __local->gid = frm->root->gid;                         \
                frm->root->uid = 0;                                    \
                frm->root->gid = 0;                                    \
        } while (0);                                                   \

#define FRAME_SU_UNDO(frm, local_type)                                 \
        do {                                                           \
                local_type *__local = (frm)->local;                    \
                frm->root->uid = __local->uid;                         \
                frm->root->gid = __local->gid;                         \
        } while (0);                                                   \


/* NOTE: make sure to keep this as an macro, mainly because, we need 'fn'
   field here to be the proper fn ptr, so its address is valid entry in
   'xlator_fops' struct.
   To understand this, check the `xlator.h:struct xlator_fops`, and then
   see a STACK_WIND call, which generally calls `subvol->fops->fop`, so
   the address offset should give the index */

/* +1 is required as 0 means NULL fop, and we don't have a variable for it */
#define get_fop_index_from_fn(xl, fn)                                   \
        (1 + (((long)&(fn) - (long)&((xl)->fops->stat)) / sizeof (void *)))

/* NOTE: the above reason holds good here too. But notice that we are getting
 the base address of the 'stat' fop, which is the first entry in the fop
 structure. All we need to do is move as much as 'idx' fields, and get the
 actual pointer from that field. */

static inline void *
get_the_pt_fop(void *base_fop, int fop_idx)
{
        void *target_addr = (base_fop + ((fop_idx - 1) * sizeof (void *)));
        /* all below type casting is for not getting warning. */
        return (void *)*(unsigned long *)target_addr;
}

/* make a call without switching frames */
#define STACK_WIND_TAIL(frame, obj, fn, params ...)                     \
        do {                                                            \
                xlator_t     *old_THIS = NULL;                          \
                xlator_t     *next_xl = obj;                            \
                typeof(fn)    next_xl_fn = fn;                          \
                int opn = get_fop_index_from_fn((next_xl), (fn));       \
                                                                        \
                frame->this = next_xl;                                  \
                frame->wind_to = #fn;                                   \
                old_THIS = THIS;                                        \
                THIS = next_xl;                                         \
                gf_msg_trace ("stack-trace", 0,                         \
                              "stack-address: %p, "                     \
                              "winding from %s to %s",                  \
                              frame->root, old_THIS->name,              \
                              THIS->name);                              \
                /* Need to capture counts at leaf node */               \
                if (!next_xl->pass_through && !next_xl->children) {     \
                        GF_ATOMIC_INC (next_xl->stats.total.metrics[opn].fop); \
                        GF_ATOMIC_INC (next_xl->stats.interval.metrics[opn].fop); \
                        GF_ATOMIC_INC (next_xl->stats.total.count);     \
                        GF_ATOMIC_INC (next_xl->stats.interval.count);  \
                }                                                       \
                                                                        \
                if (next_xl->pass_through) {                            \
                        next_xl_fn = get_the_pt_fop(&next_xl->pass_through_fops->stat, opn); \
                }                                                       \
                next_xl_fn (frame, next_xl, params);                    \
                THIS = old_THIS;                                        \
        } while (0)


/* make a call */
#define STACK_WIND(frame, rfn, obj, fn, params ...)             \
        STACK_WIND_COMMON(frame, rfn, 0, NULL, obj, fn, params)

/* make a call with a cookie */
#define STACK_WIND_COOKIE(frame, rfn, cky, obj, fn, params ...) \
        STACK_WIND_COMMON(frame, rfn, 1, cky, obj, fn, params)

/* Cookie passed as the argument can be NULL (ptr) or 0 (int). Hence we
   have to have a mechanism to separate out the two STACK_WIND formats.
   Needed a common macro, as other than for cookie, all the other code
   is common across.
 */
#define STACK_WIND_COMMON(frame, rfn, has_cookie, cky, obj, fn, params ...) \
        do {                                                            \
                call_frame_t *_new = NULL;                              \
                xlator_t     *old_THIS = NULL;                          \
                typeof(fn)    next_xl_fn = fn;                          \
                                                                        \
                _new = mem_get0 (frame->root->pool->frame_mem_pool);    \
                if (!_new) {                                            \
                        break;                                          \
                }                                                       \
                typeof(fn##_cbk) tmp_cbk = rfn;                         \
                _new->root = frame->root;                               \
                _new->this = obj;                                       \
                _new->ret = (ret_fn_t) tmp_cbk;                         \
                _new->parent = frame;                                   \
                /* (void *) is required for avoiding gcc warning */     \
                _new->cookie = ((has_cookie == 1) ?                     \
                                (void *)(cky) : (void *)_new);          \
                _new->wind_from = __FUNCTION__;                         \
                _new->wind_to = #fn;                                    \
                _new->unwind_to = #rfn;                                 \
                LOCK_INIT (&_new->lock);                                \
                LOCK(&frame->root->stack_lock);                         \
                {                                                       \
                        list_add (&_new->frames, &frame->root->myframes);\
                        frame->ref_count++;                             \
                }                                                       \
                UNLOCK(&frame->root->stack_lock);                       \
                fn##_cbk = rfn;                                         \
                old_THIS = THIS;                                        \
                THIS = obj;                                             \
                gf_msg_trace ("stack-trace", 0,                         \
                              "stack-address: %p, "                     \
                              "winding from %s to %s",                  \
                              frame->root, old_THIS->name,              \
                              THIS->name);                              \
                if (obj->ctx->measure_latency)                          \
                        timespec_now (&_new->begin);                    \
                _new->op = get_fop_index_from_fn ((_new->this), (fn));  \
                if (!obj->pass_through) {                               \
                        GF_ATOMIC_INC (obj->stats.total.metrics[_new->op].fop); \
                        GF_ATOMIC_INC (obj->stats.interval.metrics[_new->op].fop); \
                        GF_ATOMIC_INC (obj->stats.total.count);         \
                        GF_ATOMIC_INC (obj->stats.interval.count);      \
                } else {                                                \
                        /* we want to get to the actual fop to call */  \
                        next_xl_fn = get_the_pt_fop(&obj->pass_through_fops->stat, _new->op); \
                }                                                       \
                next_xl_fn (_new, obj, params);                         \
                THIS = old_THIS;                                        \
        } while (0)


#define STACK_UNWIND STACK_UNWIND_STRICT

/* return from function in type-safe way */
#define STACK_UNWIND_STRICT(fop, frame, op_ret, op_errno, params ...)   \
        do {                                                            \
                fop_##fop##_cbk_t      fn = NULL;                       \
                call_frame_t *_parent = NULL;                           \
                xlator_t     *old_THIS = NULL;                          \
                                                                        \
                if (!frame) {                                           \
                        gf_msg ("stack", GF_LOG_CRITICAL, 0,            \
                                LG_MSG_FRAME_ERROR, "!frame");          \
                        break;                                          \
                }                                                       \
                if ((op_ret) < 0) {                                     \
                        gf_msg_debug ("stack-trace", op_errno,          \
                                      "stack-address: %p, "             \
                                      "%s returned %d error: %s",       \
                                      frame->root, THIS->name,          \
                                      (int32_t)(op_ret),                \
                                      strerror(op_errno));              \
                } else {                                                \
                        gf_msg_trace ("stack-trace", 0,                 \
                                      "stack-address: %p, "             \
                                      "%s returned %d",                 \
                                      frame->root, THIS->name,          \
                                      (int32_t)(op_ret));               \
                }                                                       \
                fn = (fop_##fop##_cbk_t)frame->ret;                     \
                _parent = frame->parent;                                \
                LOCK(&frame->root->stack_lock);                         \
                {                                                       \
                        _parent->ref_count--;                           \
                        if ((op_ret) < 0 &&                             \
                            (op_errno) != frame->root->error) {         \
                                frame->root->err_xl = frame->this;      \
                                frame->root->error = (op_errno);        \
                        } else if ((op_ret) == 0) {                     \
                                frame->root->err_xl = NULL;             \
                                frame->root->error = 0;                 \
                        }                                               \
                }                                                       \
                UNLOCK(&frame->root->stack_lock);                       \
                old_THIS = THIS;                                        \
                THIS = _parent->this;                                   \
                frame->complete = _gf_true;                             \
                frame->unwind_from = __FUNCTION__;                      \
                if (frame->this->ctx->measure_latency) {                \
                        timespec_now (&frame->end);                     \
                        /* required for top most xlator */              \
                        if (_parent->ret == NULL)                       \
                                timespec_now (&_parent->end);           \
                }                                                       \
                if (op_ret < 0) {                                       \
                        GF_ATOMIC_INC (THIS->stats.total.metrics[frame->op].cbk); \
                        GF_ATOMIC_INC (THIS->stats.interval.metrics[frame->op].cbk); \
                }                                                       \
                fn (_parent, frame->cookie, _parent->this, op_ret,      \
                    op_errno, params);                                  \
                THIS = old_THIS;                                        \
        } while (0)


static inline int
call_stack_alloc_groups (call_stack_t *stack, int ngrps)
{
	if (ngrps <= SMALL_GROUP_COUNT) {
		stack->groups = stack->groups_small;
	} else {
		stack->groups_large = GF_CALLOC (ngrps, sizeof (gid_t),
						 gf_common_mt_groups_t);
		if (!stack->groups_large)
			return -1;
		stack->groups = stack->groups_large;
	}

	stack->ngrps = ngrps;

	return 0;
}

static inline
int call_frames_count (call_stack_t *call_stack)
{
        call_frame_t *pos;
        int32_t count = 0;

        if (!call_stack)
                return count;

        list_for_each_entry (pos, &call_stack->myframes, frames)
                count++;

        return count;
}

static inline call_frame_t *
copy_frame (call_frame_t *frame)
{
        call_stack_t *newstack = NULL;
        call_stack_t *oldstack = NULL;
        call_frame_t *newframe = NULL;

        if (!frame) {
                return NULL;
        }

        newstack = mem_get0 (frame->root->pool->stack_mem_pool);
        if (newstack == NULL) {
                return NULL;
        }

        INIT_LIST_HEAD (&newstack->myframes);

        newframe = mem_get0 (frame->root->pool->frame_mem_pool);
        if (!newframe) {
                mem_put (newstack);
                return NULL;
        }

        newframe->this = frame->this;
        newframe->root = newstack;
        INIT_LIST_HEAD (&newframe->frames);
        list_add (&newframe->frames, &newstack->myframes);

        oldstack = frame->root;

        newstack->uid = oldstack->uid;
        newstack->gid = oldstack->gid;
        newstack->pid = oldstack->pid;
        newstack->op  = oldstack->op;
        newstack->type = oldstack->type;
        newstack->ctime = oldstack->ctime;
        newstack->flags = oldstack->flags;
	if (call_stack_alloc_groups (newstack, oldstack->ngrps) != 0) {
		mem_put (newstack);
		return NULL;
	}
        if (!oldstack->groups) {
                gf_msg_debug ("stack", EINVAL, "groups is null (ngrps: %d)",
                              oldstack->ngrps);
                /* Considering 'groups' is NULL, set ngrps to 0 */
                oldstack->ngrps = 0;

                if (oldstack->groups_large)
                        oldstack->groups = oldstack->groups_large;
                else
                        oldstack->groups = oldstack->groups_small;
        }
        newstack->ngrps = oldstack->ngrps;
        memcpy (newstack->groups, oldstack->groups,
                sizeof (gid_t) * oldstack->ngrps);
        newstack->unique = oldstack->unique;
        newstack->pool = oldstack->pool;
        newstack->lk_owner = oldstack->lk_owner;
        newstack->ctx = oldstack->ctx;

        if (newstack->ctx->measure_latency) {
                timespec_now (&newstack->tv);
                memcpy (&newframe->begin, &newstack->tv,
                        sizeof (newstack->tv));
        }

        LOCK_INIT (&newframe->lock);
        LOCK_INIT (&newstack->stack_lock);

        LOCK (&oldstack->pool->lock);
        {
                list_add (&newstack->all_frames, &oldstack->all_frames);
                newstack->pool->cnt++;
        }
        UNLOCK (&oldstack->pool->lock);
        GF_ATOMIC_INC (newstack->pool->total_count);

        return newframe;
}

void call_stack_set_groups (call_stack_t *stack, int ngrps, gid_t **groupbuf_p);
void gf_proc_dump_pending_frames(call_pool_t *call_pool);
void gf_proc_dump_pending_frames_to_dict (call_pool_t *call_pool,
                                          dict_t *dict);
call_frame_t *create_frame (xlator_t *xl, call_pool_t *pool);
gf_boolean_t __is_fuse_call (call_frame_t *frame);
#endif /* _STACK_H */