xref: /OK3568_Linux_fs/kernel/fs/ocfs2/reservations.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /* -*- mode: c; c-basic-offset: 8; -*-
3*4882a593Smuzhiyun  * vim: noexpandtab sw=8 ts=8 sts=0:
4*4882a593Smuzhiyun  *
5*4882a593Smuzhiyun  * reservations.c
6*4882a593Smuzhiyun  *
7*4882a593Smuzhiyun  * Allocation reservations implementation
8*4882a593Smuzhiyun  *
9*4882a593Smuzhiyun  * Some code borrowed from fs/ext3/balloc.c and is:
10*4882a593Smuzhiyun  *
11*4882a593Smuzhiyun  * Copyright (C) 1992, 1993, 1994, 1995
12*4882a593Smuzhiyun  * Remy Card (card@masi.ibp.fr)
13*4882a593Smuzhiyun  * Laboratoire MASI - Institut Blaise Pascal
14*4882a593Smuzhiyun  * Universite Pierre et Marie Curie (Paris VI)
15*4882a593Smuzhiyun  *
16*4882a593Smuzhiyun  * The rest is copyright (C) 2010 Novell.  All rights reserved.
17*4882a593Smuzhiyun  */
18*4882a593Smuzhiyun 
19*4882a593Smuzhiyun #include <linux/fs.h>
20*4882a593Smuzhiyun #include <linux/types.h>
21*4882a593Smuzhiyun #include <linux/highmem.h>
22*4882a593Smuzhiyun #include <linux/bitops.h>
23*4882a593Smuzhiyun #include <linux/list.h>
24*4882a593Smuzhiyun 
25*4882a593Smuzhiyun #include <cluster/masklog.h>
26*4882a593Smuzhiyun 
27*4882a593Smuzhiyun #include "ocfs2.h"
28*4882a593Smuzhiyun #include "ocfs2_trace.h"
29*4882a593Smuzhiyun 
30*4882a593Smuzhiyun #ifdef CONFIG_OCFS2_DEBUG_FS
31*4882a593Smuzhiyun #define OCFS2_CHECK_RESERVATIONS
32*4882a593Smuzhiyun #endif
33*4882a593Smuzhiyun 
34*4882a593Smuzhiyun static DEFINE_SPINLOCK(resv_lock);
35*4882a593Smuzhiyun 
ocfs2_dir_resv_allowed(struct ocfs2_super * osb)36*4882a593Smuzhiyun int ocfs2_dir_resv_allowed(struct ocfs2_super *osb)
37*4882a593Smuzhiyun {
38*4882a593Smuzhiyun 	return (osb->osb_resv_level && osb->osb_dir_resv_level);
39*4882a593Smuzhiyun }
40*4882a593Smuzhiyun 
ocfs2_resv_window_bits(struct ocfs2_reservation_map * resmap,struct ocfs2_alloc_reservation * resv)41*4882a593Smuzhiyun static unsigned int ocfs2_resv_window_bits(struct ocfs2_reservation_map *resmap,
42*4882a593Smuzhiyun 					   struct ocfs2_alloc_reservation *resv)
43*4882a593Smuzhiyun {
44*4882a593Smuzhiyun 	struct ocfs2_super *osb = resmap->m_osb;
45*4882a593Smuzhiyun 	unsigned int bits;
46*4882a593Smuzhiyun 
47*4882a593Smuzhiyun 	if (!(resv->r_flags & OCFS2_RESV_FLAG_DIR)) {
48*4882a593Smuzhiyun 		/* 8, 16, 32, 64, 128, 256, 512, 1024 */
49*4882a593Smuzhiyun 		bits = 4 << osb->osb_resv_level;
50*4882a593Smuzhiyun 	} else {
51*4882a593Smuzhiyun 		bits = 4 << osb->osb_dir_resv_level;
52*4882a593Smuzhiyun 	}
53*4882a593Smuzhiyun 	return bits;
54*4882a593Smuzhiyun }
55*4882a593Smuzhiyun 
ocfs2_resv_end(struct ocfs2_alloc_reservation * resv)56*4882a593Smuzhiyun static inline unsigned int ocfs2_resv_end(struct ocfs2_alloc_reservation *resv)
57*4882a593Smuzhiyun {
58*4882a593Smuzhiyun 	if (resv->r_len)
59*4882a593Smuzhiyun 		return resv->r_start + resv->r_len - 1;
60*4882a593Smuzhiyun 	return resv->r_start;
61*4882a593Smuzhiyun }
62*4882a593Smuzhiyun 
ocfs2_resv_empty(struct ocfs2_alloc_reservation * resv)63*4882a593Smuzhiyun static inline int ocfs2_resv_empty(struct ocfs2_alloc_reservation *resv)
64*4882a593Smuzhiyun {
65*4882a593Smuzhiyun 	return !!(resv->r_len == 0);
66*4882a593Smuzhiyun }
67*4882a593Smuzhiyun 
ocfs2_resmap_disabled(struct ocfs2_reservation_map * resmap)68*4882a593Smuzhiyun static inline int ocfs2_resmap_disabled(struct ocfs2_reservation_map *resmap)
69*4882a593Smuzhiyun {
70*4882a593Smuzhiyun 	if (resmap->m_osb->osb_resv_level == 0)
71*4882a593Smuzhiyun 		return 1;
72*4882a593Smuzhiyun 	return 0;
73*4882a593Smuzhiyun }
74*4882a593Smuzhiyun 
ocfs2_dump_resv(struct ocfs2_reservation_map * resmap)75*4882a593Smuzhiyun static void ocfs2_dump_resv(struct ocfs2_reservation_map *resmap)
76*4882a593Smuzhiyun {
77*4882a593Smuzhiyun 	struct ocfs2_super *osb = resmap->m_osb;
78*4882a593Smuzhiyun 	struct rb_node *node;
79*4882a593Smuzhiyun 	struct ocfs2_alloc_reservation *resv;
80*4882a593Smuzhiyun 	int i = 0;
81*4882a593Smuzhiyun 
82*4882a593Smuzhiyun 	mlog(ML_NOTICE, "Dumping resmap for device %s. Bitmap length: %u\n",
83*4882a593Smuzhiyun 	     osb->dev_str, resmap->m_bitmap_len);
84*4882a593Smuzhiyun 
85*4882a593Smuzhiyun 	node = rb_first(&resmap->m_reservations);
86*4882a593Smuzhiyun 	while (node) {
87*4882a593Smuzhiyun 		resv = rb_entry(node, struct ocfs2_alloc_reservation, r_node);
88*4882a593Smuzhiyun 
89*4882a593Smuzhiyun 		mlog(ML_NOTICE, "start: %u\tend: %u\tlen: %u\tlast_start: %u"
90*4882a593Smuzhiyun 		     "\tlast_len: %u\n", resv->r_start,
91*4882a593Smuzhiyun 		     ocfs2_resv_end(resv), resv->r_len, resv->r_last_start,
92*4882a593Smuzhiyun 		     resv->r_last_len);
93*4882a593Smuzhiyun 
94*4882a593Smuzhiyun 		node = rb_next(node);
95*4882a593Smuzhiyun 		i++;
96*4882a593Smuzhiyun 	}
97*4882a593Smuzhiyun 
98*4882a593Smuzhiyun 	mlog(ML_NOTICE, "%d reservations found. LRU follows\n", i);
99*4882a593Smuzhiyun 
100*4882a593Smuzhiyun 	i = 0;
101*4882a593Smuzhiyun 	list_for_each_entry(resv, &resmap->m_lru, r_lru) {
102*4882a593Smuzhiyun 		mlog(ML_NOTICE, "LRU(%d) start: %u\tend: %u\tlen: %u\t"
103*4882a593Smuzhiyun 		     "last_start: %u\tlast_len: %u\n", i, resv->r_start,
104*4882a593Smuzhiyun 		     ocfs2_resv_end(resv), resv->r_len, resv->r_last_start,
105*4882a593Smuzhiyun 		     resv->r_last_len);
106*4882a593Smuzhiyun 
107*4882a593Smuzhiyun 		i++;
108*4882a593Smuzhiyun 	}
109*4882a593Smuzhiyun }
110*4882a593Smuzhiyun 
111*4882a593Smuzhiyun #ifdef OCFS2_CHECK_RESERVATIONS
ocfs2_validate_resmap_bits(struct ocfs2_reservation_map * resmap,int i,struct ocfs2_alloc_reservation * resv)112*4882a593Smuzhiyun static int ocfs2_validate_resmap_bits(struct ocfs2_reservation_map *resmap,
113*4882a593Smuzhiyun 				      int i,
114*4882a593Smuzhiyun 				      struct ocfs2_alloc_reservation *resv)
115*4882a593Smuzhiyun {
116*4882a593Smuzhiyun 	char *disk_bitmap = resmap->m_disk_bitmap;
117*4882a593Smuzhiyun 	unsigned int start = resv->r_start;
118*4882a593Smuzhiyun 	unsigned int end = ocfs2_resv_end(resv);
119*4882a593Smuzhiyun 
120*4882a593Smuzhiyun 	while (start <= end) {
121*4882a593Smuzhiyun 		if (ocfs2_test_bit(start, disk_bitmap)) {
122*4882a593Smuzhiyun 			mlog(ML_ERROR,
123*4882a593Smuzhiyun 			     "reservation %d covers an allocated area "
124*4882a593Smuzhiyun 			     "starting at bit %u!\n", i, start);
125*4882a593Smuzhiyun 			return 1;
126*4882a593Smuzhiyun 		}
127*4882a593Smuzhiyun 
128*4882a593Smuzhiyun 		start++;
129*4882a593Smuzhiyun 	}
130*4882a593Smuzhiyun 	return 0;
131*4882a593Smuzhiyun }
132*4882a593Smuzhiyun 
ocfs2_check_resmap(struct ocfs2_reservation_map * resmap)133*4882a593Smuzhiyun static void ocfs2_check_resmap(struct ocfs2_reservation_map *resmap)
134*4882a593Smuzhiyun {
135*4882a593Smuzhiyun 	unsigned int off = 0;
136*4882a593Smuzhiyun 	int i = 0;
137*4882a593Smuzhiyun 	struct rb_node *node;
138*4882a593Smuzhiyun 	struct ocfs2_alloc_reservation *resv;
139*4882a593Smuzhiyun 
140*4882a593Smuzhiyun 	node = rb_first(&resmap->m_reservations);
141*4882a593Smuzhiyun 	while (node) {
142*4882a593Smuzhiyun 		resv = rb_entry(node, struct ocfs2_alloc_reservation, r_node);
143*4882a593Smuzhiyun 
144*4882a593Smuzhiyun 		if (i > 0 && resv->r_start <= off) {
145*4882a593Smuzhiyun 			mlog(ML_ERROR, "reservation %d has bad start off!\n",
146*4882a593Smuzhiyun 			     i);
147*4882a593Smuzhiyun 			goto bad;
148*4882a593Smuzhiyun 		}
149*4882a593Smuzhiyun 
150*4882a593Smuzhiyun 		if (resv->r_len == 0) {
151*4882a593Smuzhiyun 			mlog(ML_ERROR, "reservation %d has no length!\n",
152*4882a593Smuzhiyun 			     i);
153*4882a593Smuzhiyun 			goto bad;
154*4882a593Smuzhiyun 		}
155*4882a593Smuzhiyun 
156*4882a593Smuzhiyun 		if (resv->r_start > ocfs2_resv_end(resv)) {
157*4882a593Smuzhiyun 			mlog(ML_ERROR, "reservation %d has invalid range!\n",
158*4882a593Smuzhiyun 			     i);
159*4882a593Smuzhiyun 			goto bad;
160*4882a593Smuzhiyun 		}
161*4882a593Smuzhiyun 
162*4882a593Smuzhiyun 		if (ocfs2_resv_end(resv) >= resmap->m_bitmap_len) {
163*4882a593Smuzhiyun 			mlog(ML_ERROR, "reservation %d extends past bitmap!\n",
164*4882a593Smuzhiyun 			     i);
165*4882a593Smuzhiyun 			goto bad;
166*4882a593Smuzhiyun 		}
167*4882a593Smuzhiyun 
168*4882a593Smuzhiyun 		if (ocfs2_validate_resmap_bits(resmap, i, resv))
169*4882a593Smuzhiyun 			goto bad;
170*4882a593Smuzhiyun 
171*4882a593Smuzhiyun 		off = ocfs2_resv_end(resv);
172*4882a593Smuzhiyun 		node = rb_next(node);
173*4882a593Smuzhiyun 
174*4882a593Smuzhiyun 		i++;
175*4882a593Smuzhiyun 	}
176*4882a593Smuzhiyun 	return;
177*4882a593Smuzhiyun 
178*4882a593Smuzhiyun bad:
179*4882a593Smuzhiyun 	ocfs2_dump_resv(resmap);
180*4882a593Smuzhiyun 	BUG();
181*4882a593Smuzhiyun }
182*4882a593Smuzhiyun #else
ocfs2_check_resmap(struct ocfs2_reservation_map * resmap)183*4882a593Smuzhiyun static inline void ocfs2_check_resmap(struct ocfs2_reservation_map *resmap)
184*4882a593Smuzhiyun {
185*4882a593Smuzhiyun 
186*4882a593Smuzhiyun }
187*4882a593Smuzhiyun #endif
188*4882a593Smuzhiyun 
ocfs2_resv_init_once(struct ocfs2_alloc_reservation * resv)189*4882a593Smuzhiyun void ocfs2_resv_init_once(struct ocfs2_alloc_reservation *resv)
190*4882a593Smuzhiyun {
191*4882a593Smuzhiyun 	memset(resv, 0, sizeof(*resv));
192*4882a593Smuzhiyun 	INIT_LIST_HEAD(&resv->r_lru);
193*4882a593Smuzhiyun }
194*4882a593Smuzhiyun 
ocfs2_resv_set_type(struct ocfs2_alloc_reservation * resv,unsigned int flags)195*4882a593Smuzhiyun void ocfs2_resv_set_type(struct ocfs2_alloc_reservation *resv,
196*4882a593Smuzhiyun 			 unsigned int flags)
197*4882a593Smuzhiyun {
198*4882a593Smuzhiyun 	BUG_ON(flags & ~OCFS2_RESV_TYPES);
199*4882a593Smuzhiyun 
200*4882a593Smuzhiyun 	resv->r_flags |= flags;
201*4882a593Smuzhiyun }
202*4882a593Smuzhiyun 
ocfs2_resmap_init(struct ocfs2_super * osb,struct ocfs2_reservation_map * resmap)203*4882a593Smuzhiyun int ocfs2_resmap_init(struct ocfs2_super *osb,
204*4882a593Smuzhiyun 		      struct ocfs2_reservation_map *resmap)
205*4882a593Smuzhiyun {
206*4882a593Smuzhiyun 	memset(resmap, 0, sizeof(*resmap));
207*4882a593Smuzhiyun 
208*4882a593Smuzhiyun 	resmap->m_osb = osb;
209*4882a593Smuzhiyun 	resmap->m_reservations = RB_ROOT;
210*4882a593Smuzhiyun 	/* m_bitmap_len is initialized to zero by the above memset. */
211*4882a593Smuzhiyun 	INIT_LIST_HEAD(&resmap->m_lru);
212*4882a593Smuzhiyun 
213*4882a593Smuzhiyun 	return 0;
214*4882a593Smuzhiyun }
215*4882a593Smuzhiyun 
ocfs2_resv_mark_lru(struct ocfs2_reservation_map * resmap,struct ocfs2_alloc_reservation * resv)216*4882a593Smuzhiyun static void ocfs2_resv_mark_lru(struct ocfs2_reservation_map *resmap,
217*4882a593Smuzhiyun 				struct ocfs2_alloc_reservation *resv)
218*4882a593Smuzhiyun {
219*4882a593Smuzhiyun 	assert_spin_locked(&resv_lock);
220*4882a593Smuzhiyun 
221*4882a593Smuzhiyun 	if (!list_empty(&resv->r_lru))
222*4882a593Smuzhiyun 		list_del_init(&resv->r_lru);
223*4882a593Smuzhiyun 
224*4882a593Smuzhiyun 	list_add_tail(&resv->r_lru, &resmap->m_lru);
225*4882a593Smuzhiyun }
226*4882a593Smuzhiyun 
__ocfs2_resv_trunc(struct ocfs2_alloc_reservation * resv)227*4882a593Smuzhiyun static void __ocfs2_resv_trunc(struct ocfs2_alloc_reservation *resv)
228*4882a593Smuzhiyun {
229*4882a593Smuzhiyun 	resv->r_len = 0;
230*4882a593Smuzhiyun 	resv->r_start = 0;
231*4882a593Smuzhiyun }
232*4882a593Smuzhiyun 
ocfs2_resv_remove(struct ocfs2_reservation_map * resmap,struct ocfs2_alloc_reservation * resv)233*4882a593Smuzhiyun static void ocfs2_resv_remove(struct ocfs2_reservation_map *resmap,
234*4882a593Smuzhiyun 			      struct ocfs2_alloc_reservation *resv)
235*4882a593Smuzhiyun {
236*4882a593Smuzhiyun 	if (resv->r_flags & OCFS2_RESV_FLAG_INUSE) {
237*4882a593Smuzhiyun 		list_del_init(&resv->r_lru);
238*4882a593Smuzhiyun 		rb_erase(&resv->r_node, &resmap->m_reservations);
239*4882a593Smuzhiyun 		resv->r_flags &= ~OCFS2_RESV_FLAG_INUSE;
240*4882a593Smuzhiyun 	}
241*4882a593Smuzhiyun }
242*4882a593Smuzhiyun 
__ocfs2_resv_discard(struct ocfs2_reservation_map * resmap,struct ocfs2_alloc_reservation * resv)243*4882a593Smuzhiyun static void __ocfs2_resv_discard(struct ocfs2_reservation_map *resmap,
244*4882a593Smuzhiyun 				 struct ocfs2_alloc_reservation *resv)
245*4882a593Smuzhiyun {
246*4882a593Smuzhiyun 	assert_spin_locked(&resv_lock);
247*4882a593Smuzhiyun 
248*4882a593Smuzhiyun 	__ocfs2_resv_trunc(resv);
249*4882a593Smuzhiyun 	/*
250*4882a593Smuzhiyun 	 * last_len and last_start no longer make sense if
251*4882a593Smuzhiyun 	 * we're changing the range of our allocations.
252*4882a593Smuzhiyun 	 */
253*4882a593Smuzhiyun 	resv->r_last_len = resv->r_last_start = 0;
254*4882a593Smuzhiyun 
255*4882a593Smuzhiyun 	ocfs2_resv_remove(resmap, resv);
256*4882a593Smuzhiyun }
257*4882a593Smuzhiyun 
258*4882a593Smuzhiyun /* does nothing if 'resv' is null */
ocfs2_resv_discard(struct ocfs2_reservation_map * resmap,struct ocfs2_alloc_reservation * resv)259*4882a593Smuzhiyun void ocfs2_resv_discard(struct ocfs2_reservation_map *resmap,
260*4882a593Smuzhiyun 			struct ocfs2_alloc_reservation *resv)
261*4882a593Smuzhiyun {
262*4882a593Smuzhiyun 	if (resv) {
263*4882a593Smuzhiyun 		spin_lock(&resv_lock);
264*4882a593Smuzhiyun 		__ocfs2_resv_discard(resmap, resv);
265*4882a593Smuzhiyun 		spin_unlock(&resv_lock);
266*4882a593Smuzhiyun 	}
267*4882a593Smuzhiyun }
268*4882a593Smuzhiyun 
ocfs2_resmap_clear_all_resv(struct ocfs2_reservation_map * resmap)269*4882a593Smuzhiyun static void ocfs2_resmap_clear_all_resv(struct ocfs2_reservation_map *resmap)
270*4882a593Smuzhiyun {
271*4882a593Smuzhiyun 	struct rb_node *node;
272*4882a593Smuzhiyun 	struct ocfs2_alloc_reservation *resv;
273*4882a593Smuzhiyun 
274*4882a593Smuzhiyun 	assert_spin_locked(&resv_lock);
275*4882a593Smuzhiyun 
276*4882a593Smuzhiyun 	while ((node = rb_last(&resmap->m_reservations)) != NULL) {
277*4882a593Smuzhiyun 		resv = rb_entry(node, struct ocfs2_alloc_reservation, r_node);
278*4882a593Smuzhiyun 
279*4882a593Smuzhiyun 		__ocfs2_resv_discard(resmap, resv);
280*4882a593Smuzhiyun 	}
281*4882a593Smuzhiyun }
282*4882a593Smuzhiyun 
ocfs2_resmap_restart(struct ocfs2_reservation_map * resmap,unsigned int clen,char * disk_bitmap)283*4882a593Smuzhiyun void ocfs2_resmap_restart(struct ocfs2_reservation_map *resmap,
284*4882a593Smuzhiyun 			  unsigned int clen, char *disk_bitmap)
285*4882a593Smuzhiyun {
286*4882a593Smuzhiyun 	if (ocfs2_resmap_disabled(resmap))
287*4882a593Smuzhiyun 		return;
288*4882a593Smuzhiyun 
289*4882a593Smuzhiyun 	spin_lock(&resv_lock);
290*4882a593Smuzhiyun 
291*4882a593Smuzhiyun 	ocfs2_resmap_clear_all_resv(resmap);
292*4882a593Smuzhiyun 	resmap->m_bitmap_len = clen;
293*4882a593Smuzhiyun 	resmap->m_disk_bitmap = disk_bitmap;
294*4882a593Smuzhiyun 
295*4882a593Smuzhiyun 	spin_unlock(&resv_lock);
296*4882a593Smuzhiyun }
297*4882a593Smuzhiyun 
ocfs2_resmap_uninit(struct ocfs2_reservation_map * resmap)298*4882a593Smuzhiyun void ocfs2_resmap_uninit(struct ocfs2_reservation_map *resmap)
299*4882a593Smuzhiyun {
300*4882a593Smuzhiyun 	/* Does nothing for now. Keep this around for API symmetry */
301*4882a593Smuzhiyun }
302*4882a593Smuzhiyun 
ocfs2_resv_insert(struct ocfs2_reservation_map * resmap,struct ocfs2_alloc_reservation * new)303*4882a593Smuzhiyun static void ocfs2_resv_insert(struct ocfs2_reservation_map *resmap,
304*4882a593Smuzhiyun 			      struct ocfs2_alloc_reservation *new)
305*4882a593Smuzhiyun {
306*4882a593Smuzhiyun 	struct rb_root *root = &resmap->m_reservations;
307*4882a593Smuzhiyun 	struct rb_node *parent = NULL;
308*4882a593Smuzhiyun 	struct rb_node **p = &root->rb_node;
309*4882a593Smuzhiyun 	struct ocfs2_alloc_reservation *tmp;
310*4882a593Smuzhiyun 
311*4882a593Smuzhiyun 	assert_spin_locked(&resv_lock);
312*4882a593Smuzhiyun 
313*4882a593Smuzhiyun 	trace_ocfs2_resv_insert(new->r_start, new->r_len);
314*4882a593Smuzhiyun 
315*4882a593Smuzhiyun 	while (*p) {
316*4882a593Smuzhiyun 		parent = *p;
317*4882a593Smuzhiyun 
318*4882a593Smuzhiyun 		tmp = rb_entry(parent, struct ocfs2_alloc_reservation, r_node);
319*4882a593Smuzhiyun 
320*4882a593Smuzhiyun 		if (new->r_start < tmp->r_start) {
321*4882a593Smuzhiyun 			p = &(*p)->rb_left;
322*4882a593Smuzhiyun 
323*4882a593Smuzhiyun 			/*
324*4882a593Smuzhiyun 			 * This is a good place to check for
325*4882a593Smuzhiyun 			 * overlapping reservations.
326*4882a593Smuzhiyun 			 */
327*4882a593Smuzhiyun 			BUG_ON(ocfs2_resv_end(new) >= tmp->r_start);
328*4882a593Smuzhiyun 		} else if (new->r_start > ocfs2_resv_end(tmp)) {
329*4882a593Smuzhiyun 			p = &(*p)->rb_right;
330*4882a593Smuzhiyun 		} else {
331*4882a593Smuzhiyun 			/* This should never happen! */
332*4882a593Smuzhiyun 			mlog(ML_ERROR, "Duplicate reservation window!\n");
333*4882a593Smuzhiyun 			BUG();
334*4882a593Smuzhiyun 		}
335*4882a593Smuzhiyun 	}
336*4882a593Smuzhiyun 
337*4882a593Smuzhiyun 	rb_link_node(&new->r_node, parent, p);
338*4882a593Smuzhiyun 	rb_insert_color(&new->r_node, root);
339*4882a593Smuzhiyun 	new->r_flags |= OCFS2_RESV_FLAG_INUSE;
340*4882a593Smuzhiyun 
341*4882a593Smuzhiyun 	ocfs2_resv_mark_lru(resmap, new);
342*4882a593Smuzhiyun 
343*4882a593Smuzhiyun 	ocfs2_check_resmap(resmap);
344*4882a593Smuzhiyun }
345*4882a593Smuzhiyun 
346*4882a593Smuzhiyun /**
347*4882a593Smuzhiyun  * ocfs2_find_resv_lhs() - find the window which contains goal
348*4882a593Smuzhiyun  * @resmap: reservation map to search
349*4882a593Smuzhiyun  * @goal: which bit to search for
350*4882a593Smuzhiyun  *
351*4882a593Smuzhiyun  * If a window containing that goal is not found, we return the window
352*4882a593Smuzhiyun  * which comes before goal. Returns NULL on empty rbtree or no window
353*4882a593Smuzhiyun  * before goal.
354*4882a593Smuzhiyun  */
355*4882a593Smuzhiyun static struct ocfs2_alloc_reservation *
ocfs2_find_resv_lhs(struct ocfs2_reservation_map * resmap,unsigned int goal)356*4882a593Smuzhiyun ocfs2_find_resv_lhs(struct ocfs2_reservation_map *resmap, unsigned int goal)
357*4882a593Smuzhiyun {
358*4882a593Smuzhiyun 	struct ocfs2_alloc_reservation *resv = NULL;
359*4882a593Smuzhiyun 	struct ocfs2_alloc_reservation *prev_resv = NULL;
360*4882a593Smuzhiyun 	struct rb_node *node = resmap->m_reservations.rb_node;
361*4882a593Smuzhiyun 
362*4882a593Smuzhiyun 	assert_spin_locked(&resv_lock);
363*4882a593Smuzhiyun 
364*4882a593Smuzhiyun 	if (!node)
365*4882a593Smuzhiyun 		return NULL;
366*4882a593Smuzhiyun 
367*4882a593Smuzhiyun 	node = rb_first(&resmap->m_reservations);
368*4882a593Smuzhiyun 	while (node) {
369*4882a593Smuzhiyun 		resv = rb_entry(node, struct ocfs2_alloc_reservation, r_node);
370*4882a593Smuzhiyun 
371*4882a593Smuzhiyun 		if (resv->r_start <= goal && ocfs2_resv_end(resv) >= goal)
372*4882a593Smuzhiyun 			break;
373*4882a593Smuzhiyun 
374*4882a593Smuzhiyun 		/* Check if we overshot the reservation just before goal? */
375*4882a593Smuzhiyun 		if (resv->r_start > goal) {
376*4882a593Smuzhiyun 			resv = prev_resv;
377*4882a593Smuzhiyun 			break;
378*4882a593Smuzhiyun 		}
379*4882a593Smuzhiyun 
380*4882a593Smuzhiyun 		prev_resv = resv;
381*4882a593Smuzhiyun 		node = rb_next(node);
382*4882a593Smuzhiyun 	}
383*4882a593Smuzhiyun 
384*4882a593Smuzhiyun 	return resv;
385*4882a593Smuzhiyun }
386*4882a593Smuzhiyun 
387*4882a593Smuzhiyun /*
388*4882a593Smuzhiyun  * We are given a range within the bitmap, which corresponds to a gap
389*4882a593Smuzhiyun  * inside the reservations tree (search_start, search_len). The range
390*4882a593Smuzhiyun  * can be anything from the whole bitmap, to a gap between
391*4882a593Smuzhiyun  * reservations.
392*4882a593Smuzhiyun  *
393*4882a593Smuzhiyun  * The start value of *rstart is insignificant.
394*4882a593Smuzhiyun  *
395*4882a593Smuzhiyun  * This function searches the bitmap range starting at search_start
396*4882a593Smuzhiyun  * with length search_len for a set of contiguous free bits. We try
397*4882a593Smuzhiyun  * to find up to 'wanted' bits, but can sometimes return less.
398*4882a593Smuzhiyun  *
399*4882a593Smuzhiyun  * Returns the length of allocation, 0 if no free bits are found.
400*4882a593Smuzhiyun  *
401*4882a593Smuzhiyun  * *cstart and *clen will also be populated with the result.
402*4882a593Smuzhiyun  */
ocfs2_resmap_find_free_bits(struct ocfs2_reservation_map * resmap,unsigned int wanted,unsigned int search_start,unsigned int search_len,unsigned int * rstart,unsigned int * rlen)403*4882a593Smuzhiyun static int ocfs2_resmap_find_free_bits(struct ocfs2_reservation_map *resmap,
404*4882a593Smuzhiyun 				       unsigned int wanted,
405*4882a593Smuzhiyun 				       unsigned int search_start,
406*4882a593Smuzhiyun 				       unsigned int search_len,
407*4882a593Smuzhiyun 				       unsigned int *rstart,
408*4882a593Smuzhiyun 				       unsigned int *rlen)
409*4882a593Smuzhiyun {
410*4882a593Smuzhiyun 	void *bitmap = resmap->m_disk_bitmap;
411*4882a593Smuzhiyun 	unsigned int best_start, best_len = 0;
412*4882a593Smuzhiyun 	int offset, start, found;
413*4882a593Smuzhiyun 
414*4882a593Smuzhiyun 	trace_ocfs2_resmap_find_free_bits_begin(search_start, search_len,
415*4882a593Smuzhiyun 						wanted, resmap->m_bitmap_len);
416*4882a593Smuzhiyun 
417*4882a593Smuzhiyun 	found = best_start = best_len = 0;
418*4882a593Smuzhiyun 
419*4882a593Smuzhiyun 	start = search_start;
420*4882a593Smuzhiyun 	while ((offset = ocfs2_find_next_zero_bit(bitmap, resmap->m_bitmap_len,
421*4882a593Smuzhiyun 						 start)) != -1) {
422*4882a593Smuzhiyun 		/* Search reached end of the region */
423*4882a593Smuzhiyun 		if (offset >= (search_start + search_len))
424*4882a593Smuzhiyun 			break;
425*4882a593Smuzhiyun 
426*4882a593Smuzhiyun 		if (offset == start) {
427*4882a593Smuzhiyun 			/* we found a zero */
428*4882a593Smuzhiyun 			found++;
429*4882a593Smuzhiyun 			/* move start to the next bit to test */
430*4882a593Smuzhiyun 			start++;
431*4882a593Smuzhiyun 		} else {
432*4882a593Smuzhiyun 			/* got a zero after some ones */
433*4882a593Smuzhiyun 			found = 1;
434*4882a593Smuzhiyun 			start = offset + 1;
435*4882a593Smuzhiyun 		}
436*4882a593Smuzhiyun 		if (found > best_len) {
437*4882a593Smuzhiyun 			best_len = found;
438*4882a593Smuzhiyun 			best_start = start - found;
439*4882a593Smuzhiyun 		}
440*4882a593Smuzhiyun 
441*4882a593Smuzhiyun 		if (found >= wanted)
442*4882a593Smuzhiyun 			break;
443*4882a593Smuzhiyun 	}
444*4882a593Smuzhiyun 
445*4882a593Smuzhiyun 	if (best_len == 0)
446*4882a593Smuzhiyun 		return 0;
447*4882a593Smuzhiyun 
448*4882a593Smuzhiyun 	if (best_len >= wanted)
449*4882a593Smuzhiyun 		best_len = wanted;
450*4882a593Smuzhiyun 
451*4882a593Smuzhiyun 	*rlen = best_len;
452*4882a593Smuzhiyun 	*rstart = best_start;
453*4882a593Smuzhiyun 
454*4882a593Smuzhiyun 	trace_ocfs2_resmap_find_free_bits_end(best_start, best_len);
455*4882a593Smuzhiyun 
456*4882a593Smuzhiyun 	return *rlen;
457*4882a593Smuzhiyun }
458*4882a593Smuzhiyun 
__ocfs2_resv_find_window(struct ocfs2_reservation_map * resmap,struct ocfs2_alloc_reservation * resv,unsigned int goal,unsigned int wanted)459*4882a593Smuzhiyun static void __ocfs2_resv_find_window(struct ocfs2_reservation_map *resmap,
460*4882a593Smuzhiyun 				     struct ocfs2_alloc_reservation *resv,
461*4882a593Smuzhiyun 				     unsigned int goal, unsigned int wanted)
462*4882a593Smuzhiyun {
463*4882a593Smuzhiyun 	struct rb_root *root = &resmap->m_reservations;
464*4882a593Smuzhiyun 	unsigned int gap_start, gap_end, gap_len;
465*4882a593Smuzhiyun 	struct ocfs2_alloc_reservation *prev_resv, *next_resv;
466*4882a593Smuzhiyun 	struct rb_node *prev, *next;
467*4882a593Smuzhiyun 	unsigned int cstart, clen;
468*4882a593Smuzhiyun 	unsigned int best_start = 0, best_len = 0;
469*4882a593Smuzhiyun 
470*4882a593Smuzhiyun 	/*
471*4882a593Smuzhiyun 	 * Nasty cases to consider:
472*4882a593Smuzhiyun 	 *
473*4882a593Smuzhiyun 	 * - rbtree is empty
474*4882a593Smuzhiyun 	 * - our window should be first in all reservations
475*4882a593Smuzhiyun 	 * - our window should be last in all reservations
476*4882a593Smuzhiyun 	 * - need to make sure we don't go past end of bitmap
477*4882a593Smuzhiyun 	 */
478*4882a593Smuzhiyun 	trace_ocfs2_resv_find_window_begin(resv->r_start, ocfs2_resv_end(resv),
479*4882a593Smuzhiyun 					   goal, wanted, RB_EMPTY_ROOT(root));
480*4882a593Smuzhiyun 
481*4882a593Smuzhiyun 	assert_spin_locked(&resv_lock);
482*4882a593Smuzhiyun 
483*4882a593Smuzhiyun 	if (RB_EMPTY_ROOT(root)) {
484*4882a593Smuzhiyun 		/*
485*4882a593Smuzhiyun 		 * Easiest case - empty tree. We can just take
486*4882a593Smuzhiyun 		 * whatever window of free bits we want.
487*4882a593Smuzhiyun 		 */
488*4882a593Smuzhiyun 		clen = ocfs2_resmap_find_free_bits(resmap, wanted, goal,
489*4882a593Smuzhiyun 						   resmap->m_bitmap_len - goal,
490*4882a593Smuzhiyun 						   &cstart, &clen);
491*4882a593Smuzhiyun 
492*4882a593Smuzhiyun 		/*
493*4882a593Smuzhiyun 		 * This should never happen - the local alloc window
494*4882a593Smuzhiyun 		 * will always have free bits when we're called.
495*4882a593Smuzhiyun 		 */
496*4882a593Smuzhiyun 		BUG_ON(goal == 0 && clen == 0);
497*4882a593Smuzhiyun 
498*4882a593Smuzhiyun 		if (clen == 0)
499*4882a593Smuzhiyun 			return;
500*4882a593Smuzhiyun 
501*4882a593Smuzhiyun 		resv->r_start = cstart;
502*4882a593Smuzhiyun 		resv->r_len = clen;
503*4882a593Smuzhiyun 
504*4882a593Smuzhiyun 		ocfs2_resv_insert(resmap, resv);
505*4882a593Smuzhiyun 		return;
506*4882a593Smuzhiyun 	}
507*4882a593Smuzhiyun 
508*4882a593Smuzhiyun 	prev_resv = ocfs2_find_resv_lhs(resmap, goal);
509*4882a593Smuzhiyun 
510*4882a593Smuzhiyun 	if (prev_resv == NULL) {
511*4882a593Smuzhiyun 		/*
512*4882a593Smuzhiyun 		 * A NULL here means that the search code couldn't
513*4882a593Smuzhiyun 		 * find a window that starts before goal.
514*4882a593Smuzhiyun 		 *
515*4882a593Smuzhiyun 		 * However, we can take the first window after goal,
516*4882a593Smuzhiyun 		 * which is also by definition, the leftmost window in
517*4882a593Smuzhiyun 		 * the entire tree. If we can find free bits in the
518*4882a593Smuzhiyun 		 * gap between goal and the LHS window, then the
519*4882a593Smuzhiyun 		 * reservation can safely be placed there.
520*4882a593Smuzhiyun 		 *
521*4882a593Smuzhiyun 		 * Otherwise we fall back to a linear search, checking
522*4882a593Smuzhiyun 		 * the gaps in between windows for a place to
523*4882a593Smuzhiyun 		 * allocate.
524*4882a593Smuzhiyun 		 */
525*4882a593Smuzhiyun 
526*4882a593Smuzhiyun 		next = rb_first(root);
527*4882a593Smuzhiyun 		next_resv = rb_entry(next, struct ocfs2_alloc_reservation,
528*4882a593Smuzhiyun 				     r_node);
529*4882a593Smuzhiyun 
530*4882a593Smuzhiyun 		/*
531*4882a593Smuzhiyun 		 * The search should never return such a window. (see
532*4882a593Smuzhiyun 		 * comment above
533*4882a593Smuzhiyun 		 */
534*4882a593Smuzhiyun 		if (next_resv->r_start <= goal) {
535*4882a593Smuzhiyun 			mlog(ML_ERROR, "goal: %u next_resv: start %u len %u\n",
536*4882a593Smuzhiyun 			     goal, next_resv->r_start, next_resv->r_len);
537*4882a593Smuzhiyun 			ocfs2_dump_resv(resmap);
538*4882a593Smuzhiyun 			BUG();
539*4882a593Smuzhiyun 		}
540*4882a593Smuzhiyun 
541*4882a593Smuzhiyun 		clen = ocfs2_resmap_find_free_bits(resmap, wanted, goal,
542*4882a593Smuzhiyun 						   next_resv->r_start - goal,
543*4882a593Smuzhiyun 						   &cstart, &clen);
544*4882a593Smuzhiyun 		if (clen) {
545*4882a593Smuzhiyun 			best_len = clen;
546*4882a593Smuzhiyun 			best_start = cstart;
547*4882a593Smuzhiyun 			if (best_len == wanted)
548*4882a593Smuzhiyun 				goto out_insert;
549*4882a593Smuzhiyun 		}
550*4882a593Smuzhiyun 
551*4882a593Smuzhiyun 		prev_resv = next_resv;
552*4882a593Smuzhiyun 		next_resv = NULL;
553*4882a593Smuzhiyun 	}
554*4882a593Smuzhiyun 
555*4882a593Smuzhiyun 	trace_ocfs2_resv_find_window_prev(prev_resv->r_start,
556*4882a593Smuzhiyun 					  ocfs2_resv_end(prev_resv));
557*4882a593Smuzhiyun 
558*4882a593Smuzhiyun 	prev = &prev_resv->r_node;
559*4882a593Smuzhiyun 
560*4882a593Smuzhiyun 	/* Now we do a linear search for a window, starting at 'prev_rsv' */
561*4882a593Smuzhiyun 	while (1) {
562*4882a593Smuzhiyun 		next = rb_next(prev);
563*4882a593Smuzhiyun 		if (next) {
564*4882a593Smuzhiyun 			next_resv = rb_entry(next,
565*4882a593Smuzhiyun 					     struct ocfs2_alloc_reservation,
566*4882a593Smuzhiyun 					     r_node);
567*4882a593Smuzhiyun 
568*4882a593Smuzhiyun 			gap_start = ocfs2_resv_end(prev_resv) + 1;
569*4882a593Smuzhiyun 			gap_end = next_resv->r_start - 1;
570*4882a593Smuzhiyun 			gap_len = gap_end - gap_start + 1;
571*4882a593Smuzhiyun 		} else {
572*4882a593Smuzhiyun 			/*
573*4882a593Smuzhiyun 			 * We're at the rightmost edge of the
574*4882a593Smuzhiyun 			 * tree. See if a reservation between this
575*4882a593Smuzhiyun 			 * window and the end of the bitmap will work.
576*4882a593Smuzhiyun 			 */
577*4882a593Smuzhiyun 			gap_start = ocfs2_resv_end(prev_resv) + 1;
578*4882a593Smuzhiyun 			gap_len = resmap->m_bitmap_len - gap_start;
579*4882a593Smuzhiyun 			gap_end = resmap->m_bitmap_len - 1;
580*4882a593Smuzhiyun 		}
581*4882a593Smuzhiyun 
582*4882a593Smuzhiyun 		trace_ocfs2_resv_find_window_next(next ? next_resv->r_start: -1,
583*4882a593Smuzhiyun 					next ? ocfs2_resv_end(next_resv) : -1);
584*4882a593Smuzhiyun 		/*
585*4882a593Smuzhiyun 		 * No need to check this gap if we have already found
586*4882a593Smuzhiyun 		 * a larger region of free bits.
587*4882a593Smuzhiyun 		 */
588*4882a593Smuzhiyun 		if (gap_len <= best_len)
589*4882a593Smuzhiyun 			goto next_resv;
590*4882a593Smuzhiyun 
591*4882a593Smuzhiyun 		clen = ocfs2_resmap_find_free_bits(resmap, wanted, gap_start,
592*4882a593Smuzhiyun 						   gap_len, &cstart, &clen);
593*4882a593Smuzhiyun 		if (clen == wanted) {
594*4882a593Smuzhiyun 			best_len = clen;
595*4882a593Smuzhiyun 			best_start = cstart;
596*4882a593Smuzhiyun 			goto out_insert;
597*4882a593Smuzhiyun 		} else if (clen > best_len) {
598*4882a593Smuzhiyun 			best_len = clen;
599*4882a593Smuzhiyun 			best_start = cstart;
600*4882a593Smuzhiyun 		}
601*4882a593Smuzhiyun 
602*4882a593Smuzhiyun next_resv:
603*4882a593Smuzhiyun 		if (!next)
604*4882a593Smuzhiyun 			break;
605*4882a593Smuzhiyun 
606*4882a593Smuzhiyun 		prev = next;
607*4882a593Smuzhiyun 		prev_resv = rb_entry(prev, struct ocfs2_alloc_reservation,
608*4882a593Smuzhiyun 				     r_node);
609*4882a593Smuzhiyun 	}
610*4882a593Smuzhiyun 
611*4882a593Smuzhiyun out_insert:
612*4882a593Smuzhiyun 	if (best_len) {
613*4882a593Smuzhiyun 		resv->r_start = best_start;
614*4882a593Smuzhiyun 		resv->r_len = best_len;
615*4882a593Smuzhiyun 		ocfs2_resv_insert(resmap, resv);
616*4882a593Smuzhiyun 	}
617*4882a593Smuzhiyun }
618*4882a593Smuzhiyun 
ocfs2_cannibalize_resv(struct ocfs2_reservation_map * resmap,struct ocfs2_alloc_reservation * resv,unsigned int wanted)619*4882a593Smuzhiyun static void ocfs2_cannibalize_resv(struct ocfs2_reservation_map *resmap,
620*4882a593Smuzhiyun 				   struct ocfs2_alloc_reservation *resv,
621*4882a593Smuzhiyun 				   unsigned int wanted)
622*4882a593Smuzhiyun {
623*4882a593Smuzhiyun 	struct ocfs2_alloc_reservation *lru_resv;
624*4882a593Smuzhiyun 	int tmpwindow = !!(resv->r_flags & OCFS2_RESV_FLAG_TMP);
625*4882a593Smuzhiyun 	unsigned int min_bits;
626*4882a593Smuzhiyun 
627*4882a593Smuzhiyun 	if (!tmpwindow)
628*4882a593Smuzhiyun 		min_bits = ocfs2_resv_window_bits(resmap, resv) >> 1;
629*4882a593Smuzhiyun 	else
630*4882a593Smuzhiyun 		min_bits = wanted; /* We at know the temp window will use all
631*4882a593Smuzhiyun 				    * of these bits */
632*4882a593Smuzhiyun 
633*4882a593Smuzhiyun 	/*
634*4882a593Smuzhiyun 	 * Take the first reservation off the LRU as our 'target'. We
635*4882a593Smuzhiyun 	 * don't try to be smart about it. There might be a case for
636*4882a593Smuzhiyun 	 * searching based on size but I don't have enough data to be
637*4882a593Smuzhiyun 	 * sure. --Mark (3/16/2010)
638*4882a593Smuzhiyun 	 */
639*4882a593Smuzhiyun 	lru_resv = list_first_entry(&resmap->m_lru,
640*4882a593Smuzhiyun 				    struct ocfs2_alloc_reservation, r_lru);
641*4882a593Smuzhiyun 
642*4882a593Smuzhiyun 	trace_ocfs2_cannibalize_resv_begin(lru_resv->r_start,
643*4882a593Smuzhiyun 					   lru_resv->r_len,
644*4882a593Smuzhiyun 					   ocfs2_resv_end(lru_resv));
645*4882a593Smuzhiyun 
646*4882a593Smuzhiyun 	/*
647*4882a593Smuzhiyun 	 * Cannibalize (some or all) of the target reservation and
648*4882a593Smuzhiyun 	 * feed it to the current window.
649*4882a593Smuzhiyun 	 */
650*4882a593Smuzhiyun 	if (lru_resv->r_len <= min_bits) {
651*4882a593Smuzhiyun 		/*
652*4882a593Smuzhiyun 		 * Discard completely if size is less than or equal to a
653*4882a593Smuzhiyun 		 * reasonable threshold - 50% of window bits for non temporary
654*4882a593Smuzhiyun 		 * windows.
655*4882a593Smuzhiyun 		 */
656*4882a593Smuzhiyun 		resv->r_start = lru_resv->r_start;
657*4882a593Smuzhiyun 		resv->r_len = lru_resv->r_len;
658*4882a593Smuzhiyun 
659*4882a593Smuzhiyun 		__ocfs2_resv_discard(resmap, lru_resv);
660*4882a593Smuzhiyun 	} else {
661*4882a593Smuzhiyun 		unsigned int shrink;
662*4882a593Smuzhiyun 		if (tmpwindow)
663*4882a593Smuzhiyun 			shrink = min_bits;
664*4882a593Smuzhiyun 		else
665*4882a593Smuzhiyun 			shrink = lru_resv->r_len / 2;
666*4882a593Smuzhiyun 
667*4882a593Smuzhiyun 		lru_resv->r_len -= shrink;
668*4882a593Smuzhiyun 
669*4882a593Smuzhiyun 		resv->r_start = ocfs2_resv_end(lru_resv) + 1;
670*4882a593Smuzhiyun 		resv->r_len = shrink;
671*4882a593Smuzhiyun 	}
672*4882a593Smuzhiyun 
673*4882a593Smuzhiyun 	trace_ocfs2_cannibalize_resv_end(resv->r_start, ocfs2_resv_end(resv),
674*4882a593Smuzhiyun 					 resv->r_len, resv->r_last_start,
675*4882a593Smuzhiyun 					 resv->r_last_len);
676*4882a593Smuzhiyun 
677*4882a593Smuzhiyun 	ocfs2_resv_insert(resmap, resv);
678*4882a593Smuzhiyun }
679*4882a593Smuzhiyun 
ocfs2_resv_find_window(struct ocfs2_reservation_map * resmap,struct ocfs2_alloc_reservation * resv,unsigned int wanted)680*4882a593Smuzhiyun static void ocfs2_resv_find_window(struct ocfs2_reservation_map *resmap,
681*4882a593Smuzhiyun 				   struct ocfs2_alloc_reservation *resv,
682*4882a593Smuzhiyun 				   unsigned int wanted)
683*4882a593Smuzhiyun {
684*4882a593Smuzhiyun 	unsigned int goal = 0;
685*4882a593Smuzhiyun 
686*4882a593Smuzhiyun 	BUG_ON(!ocfs2_resv_empty(resv));
687*4882a593Smuzhiyun 
688*4882a593Smuzhiyun 	/*
689*4882a593Smuzhiyun 	 * Begin by trying to get a window as close to the previous
690*4882a593Smuzhiyun 	 * one as possible. Using the most recent allocation as a
691*4882a593Smuzhiyun 	 * start goal makes sense.
692*4882a593Smuzhiyun 	 */
693*4882a593Smuzhiyun 	if (resv->r_last_len) {
694*4882a593Smuzhiyun 		goal = resv->r_last_start + resv->r_last_len;
695*4882a593Smuzhiyun 		if (goal >= resmap->m_bitmap_len)
696*4882a593Smuzhiyun 			goal = 0;
697*4882a593Smuzhiyun 	}
698*4882a593Smuzhiyun 
699*4882a593Smuzhiyun 	__ocfs2_resv_find_window(resmap, resv, goal, wanted);
700*4882a593Smuzhiyun 
701*4882a593Smuzhiyun 	/* Search from last alloc didn't work, try once more from beginning. */
702*4882a593Smuzhiyun 	if (ocfs2_resv_empty(resv) && goal != 0)
703*4882a593Smuzhiyun 		__ocfs2_resv_find_window(resmap, resv, 0, wanted);
704*4882a593Smuzhiyun 
705*4882a593Smuzhiyun 	if (ocfs2_resv_empty(resv)) {
706*4882a593Smuzhiyun 		/*
707*4882a593Smuzhiyun 		 * Still empty? Pull oldest one off the LRU, remove it from
708*4882a593Smuzhiyun 		 * tree, put this one in it's place.
709*4882a593Smuzhiyun 		 */
710*4882a593Smuzhiyun 		ocfs2_cannibalize_resv(resmap, resv, wanted);
711*4882a593Smuzhiyun 	}
712*4882a593Smuzhiyun 
713*4882a593Smuzhiyun 	BUG_ON(ocfs2_resv_empty(resv));
714*4882a593Smuzhiyun }
715*4882a593Smuzhiyun 
ocfs2_resmap_resv_bits(struct ocfs2_reservation_map * resmap,struct ocfs2_alloc_reservation * resv,int * cstart,int * clen)716*4882a593Smuzhiyun int ocfs2_resmap_resv_bits(struct ocfs2_reservation_map *resmap,
717*4882a593Smuzhiyun 			   struct ocfs2_alloc_reservation *resv,
718*4882a593Smuzhiyun 			   int *cstart, int *clen)
719*4882a593Smuzhiyun {
720*4882a593Smuzhiyun 	if (resv == NULL || ocfs2_resmap_disabled(resmap))
721*4882a593Smuzhiyun 		return -ENOSPC;
722*4882a593Smuzhiyun 
723*4882a593Smuzhiyun 	spin_lock(&resv_lock);
724*4882a593Smuzhiyun 
725*4882a593Smuzhiyun 	if (ocfs2_resv_empty(resv)) {
726*4882a593Smuzhiyun 		/*
727*4882a593Smuzhiyun 		 * We don't want to over-allocate for temporary
728*4882a593Smuzhiyun 		 * windows. Otherwise, we run the risk of fragmenting the
729*4882a593Smuzhiyun 		 * allocation space.
730*4882a593Smuzhiyun 		 */
731*4882a593Smuzhiyun 		unsigned int wanted = ocfs2_resv_window_bits(resmap, resv);
732*4882a593Smuzhiyun 
733*4882a593Smuzhiyun 		if ((resv->r_flags & OCFS2_RESV_FLAG_TMP) || wanted < *clen)
734*4882a593Smuzhiyun 			wanted = *clen;
735*4882a593Smuzhiyun 
736*4882a593Smuzhiyun 		/*
737*4882a593Smuzhiyun 		 * Try to get a window here. If it works, we must fall
738*4882a593Smuzhiyun 		 * through and test the bitmap . This avoids some
739*4882a593Smuzhiyun 		 * ping-ponging of windows due to non-reserved space
740*4882a593Smuzhiyun 		 * being allocation before we initialize a window for
741*4882a593Smuzhiyun 		 * that inode.
742*4882a593Smuzhiyun 		 */
743*4882a593Smuzhiyun 		ocfs2_resv_find_window(resmap, resv, wanted);
744*4882a593Smuzhiyun 		trace_ocfs2_resmap_resv_bits(resv->r_start, resv->r_len);
745*4882a593Smuzhiyun 	}
746*4882a593Smuzhiyun 
747*4882a593Smuzhiyun 	BUG_ON(ocfs2_resv_empty(resv));
748*4882a593Smuzhiyun 
749*4882a593Smuzhiyun 	*cstart = resv->r_start;
750*4882a593Smuzhiyun 	*clen = resv->r_len;
751*4882a593Smuzhiyun 
752*4882a593Smuzhiyun 	spin_unlock(&resv_lock);
753*4882a593Smuzhiyun 	return 0;
754*4882a593Smuzhiyun }
755*4882a593Smuzhiyun 
756*4882a593Smuzhiyun static void
ocfs2_adjust_resv_from_alloc(struct ocfs2_reservation_map * resmap,struct ocfs2_alloc_reservation * resv,unsigned int start,unsigned int end)757*4882a593Smuzhiyun 	ocfs2_adjust_resv_from_alloc(struct ocfs2_reservation_map *resmap,
758*4882a593Smuzhiyun 				     struct ocfs2_alloc_reservation *resv,
759*4882a593Smuzhiyun 				     unsigned int start, unsigned int end)
760*4882a593Smuzhiyun {
761*4882a593Smuzhiyun 	unsigned int rhs = 0;
762*4882a593Smuzhiyun 	unsigned int old_end = ocfs2_resv_end(resv);
763*4882a593Smuzhiyun 
764*4882a593Smuzhiyun 	BUG_ON(start != resv->r_start || old_end < end);
765*4882a593Smuzhiyun 
766*4882a593Smuzhiyun 	/*
767*4882a593Smuzhiyun 	 * Completely used? We can remove it then.
768*4882a593Smuzhiyun 	 */
769*4882a593Smuzhiyun 	if (old_end == end) {
770*4882a593Smuzhiyun 		__ocfs2_resv_discard(resmap, resv);
771*4882a593Smuzhiyun 		return;
772*4882a593Smuzhiyun 	}
773*4882a593Smuzhiyun 
774*4882a593Smuzhiyun 	rhs = old_end - end;
775*4882a593Smuzhiyun 
776*4882a593Smuzhiyun 	/*
777*4882a593Smuzhiyun 	 * This should have been trapped above.
778*4882a593Smuzhiyun 	 */
779*4882a593Smuzhiyun 	BUG_ON(rhs == 0);
780*4882a593Smuzhiyun 
781*4882a593Smuzhiyun 	resv->r_start = end + 1;
782*4882a593Smuzhiyun 	resv->r_len = old_end - resv->r_start + 1;
783*4882a593Smuzhiyun }
784*4882a593Smuzhiyun 
ocfs2_resmap_claimed_bits(struct ocfs2_reservation_map * resmap,struct ocfs2_alloc_reservation * resv,u32 cstart,u32 clen)785*4882a593Smuzhiyun void ocfs2_resmap_claimed_bits(struct ocfs2_reservation_map *resmap,
786*4882a593Smuzhiyun 			       struct ocfs2_alloc_reservation *resv,
787*4882a593Smuzhiyun 			       u32 cstart, u32 clen)
788*4882a593Smuzhiyun {
789*4882a593Smuzhiyun 	unsigned int cend = cstart + clen - 1;
790*4882a593Smuzhiyun 
791*4882a593Smuzhiyun 	if (resmap == NULL || ocfs2_resmap_disabled(resmap))
792*4882a593Smuzhiyun 		return;
793*4882a593Smuzhiyun 
794*4882a593Smuzhiyun 	if (resv == NULL)
795*4882a593Smuzhiyun 		return;
796*4882a593Smuzhiyun 
797*4882a593Smuzhiyun 	BUG_ON(cstart != resv->r_start);
798*4882a593Smuzhiyun 
799*4882a593Smuzhiyun 	spin_lock(&resv_lock);
800*4882a593Smuzhiyun 
801*4882a593Smuzhiyun 	trace_ocfs2_resmap_claimed_bits_begin(cstart, cend, clen, resv->r_start,
802*4882a593Smuzhiyun 					      ocfs2_resv_end(resv), resv->r_len,
803*4882a593Smuzhiyun 					      resv->r_last_start,
804*4882a593Smuzhiyun 					      resv->r_last_len);
805*4882a593Smuzhiyun 
806*4882a593Smuzhiyun 	BUG_ON(cstart < resv->r_start);
807*4882a593Smuzhiyun 	BUG_ON(cstart > ocfs2_resv_end(resv));
808*4882a593Smuzhiyun 	BUG_ON(cend > ocfs2_resv_end(resv));
809*4882a593Smuzhiyun 
810*4882a593Smuzhiyun 	ocfs2_adjust_resv_from_alloc(resmap, resv, cstart, cend);
811*4882a593Smuzhiyun 	resv->r_last_start = cstart;
812*4882a593Smuzhiyun 	resv->r_last_len = clen;
813*4882a593Smuzhiyun 
814*4882a593Smuzhiyun 	/*
815*4882a593Smuzhiyun 	 * May have been discarded above from
816*4882a593Smuzhiyun 	 * ocfs2_adjust_resv_from_alloc().
817*4882a593Smuzhiyun 	 */
818*4882a593Smuzhiyun 	if (!ocfs2_resv_empty(resv))
819*4882a593Smuzhiyun 		ocfs2_resv_mark_lru(resmap, resv);
820*4882a593Smuzhiyun 
821*4882a593Smuzhiyun 	trace_ocfs2_resmap_claimed_bits_end(resv->r_start, ocfs2_resv_end(resv),
822*4882a593Smuzhiyun 					    resv->r_len, resv->r_last_start,
823*4882a593Smuzhiyun 					    resv->r_last_len);
824*4882a593Smuzhiyun 
825*4882a593Smuzhiyun 	ocfs2_check_resmap(resmap);
826*4882a593Smuzhiyun 
827*4882a593Smuzhiyun 	spin_unlock(&resv_lock);
828*4882a593Smuzhiyun }
829