1 /*
2  * Copyright (c) 2007-2008 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  * $DragonFly: src/sys/vfs/hammer/hammer_transaction.c,v 1.25 2008/09/23 21:03:52 dillon Exp $
35  */
36 
37 #include "hammer.h"
38 
39 static hammer_tid_t hammer_alloc_tid(hammer_mount_t hmp, int count);
40 static u_int32_t ocp_allocbit(hammer_objid_cache_t ocp, u_int32_t n);
41 
42 
43 /*
44  * Start a standard transaction.
45  */
46 void
47 hammer_start_transaction(struct hammer_transaction *trans,
48 			 struct hammer_mount *hmp)
49 {
50 	struct timeval tv;
51 	int error;
52 
53 	trans->type = HAMMER_TRANS_STD;
54 	trans->hmp = hmp;
55 	trans->rootvol = hammer_get_root_volume(hmp, &error);
56 	KKASSERT(error == 0);
57 	trans->tid = 0;
58 	trans->sync_lock_refs = 0;
59 	trans->flags = 0;
60 
61 	getmicrotime(&tv);
62 	trans->time = (unsigned long)tv.tv_sec * 1000000ULL + tv.tv_usec;
63 	trans->time32 = (u_int32_t)tv.tv_sec;
64 }
65 
66 /*
67  * Start a simple read-only transaction.  This will not stall.
68  */
69 void
70 hammer_simple_transaction(struct hammer_transaction *trans,
71 			  struct hammer_mount *hmp)
72 {
73 	struct timeval tv;
74 	int error;
75 
76 	trans->type = HAMMER_TRANS_RO;
77 	trans->hmp = hmp;
78 	trans->rootvol = hammer_get_root_volume(hmp, &error);
79 	KKASSERT(error == 0);
80 	trans->tid = 0;
81 	trans->sync_lock_refs = 0;
82 	trans->flags = 0;
83 
84 	getmicrotime(&tv);
85 	trans->time = (unsigned long)tv.tv_sec * 1000000ULL + tv.tv_usec;
86 	trans->time32 = (u_int32_t)tv.tv_sec;
87 }
88 
89 /*
90  * Start a transaction using a particular TID.  Used by the sync code.
91  * This does not stall.
92  *
93  * This routine may only be called from the flusher thread.  We predispose
94  * sync_lock_refs, implying serialization against the synchronization stage
95  * (which the flusher is responsible for).
96  */
97 void
98 hammer_start_transaction_fls(struct hammer_transaction *trans,
99 			     struct hammer_mount *hmp)
100 {
101 	struct timeval tv;
102 	int error;
103 
104 	bzero(trans, sizeof(*trans));
105 
106 	trans->type = HAMMER_TRANS_FLS;
107 	trans->hmp = hmp;
108 	trans->rootvol = hammer_get_root_volume(hmp, &error);
109 	KKASSERT(error == 0);
110 	trans->tid = hammer_alloc_tid(hmp, 1);
111 	trans->sync_lock_refs = 1;
112 	trans->flags = 0;
113 
114 	getmicrotime(&tv);
115 	trans->time = (unsigned long)tv.tv_sec * 1000000ULL + tv.tv_usec;
116 	trans->time32 = (u_int32_t)tv.tv_sec;
117 }
118 
119 void
120 hammer_done_transaction(struct hammer_transaction *trans)
121 {
122 	hammer_mount_t hmp = trans->hmp;
123 	int expected_lock_refs;
124 
125 	hammer_rel_volume(trans->rootvol, 0);
126 	trans->rootvol = NULL;
127 	expected_lock_refs = (trans->type == HAMMER_TRANS_FLS) ? 1 : 0;
128 	KKASSERT(trans->sync_lock_refs == expected_lock_refs);
129 	trans->sync_lock_refs = 0;
130 	if (trans->type != HAMMER_TRANS_FLS) {
131 		if (trans->flags & HAMMER_TRANSF_NEWINODE)
132 			hammer_inode_waitreclaims(hmp);
133 		else if (trans->flags & HAMMER_TRANSF_DIDIO)
134 			hammer_inode_waitreclaims(hmp);
135 	}
136 }
137 
138 /*
139  * Allocate (count) TIDs.  If running in multi-master mode the returned
140  * base will be aligned to a 16-count plus the master id (0-15).
141  * Multi-master mode allows non-conflicting to run and new objects to be
142  * created on multiple masters in parallel.  The transaction id identifies
143  * the original master.  The object_id is also subject to this rule in
144  * order to allow objects to be created on multiple masters in parallel.
145  *
146  * Directories may pre-allocate a large number of object ids (100,000).
147  *
148  * NOTE: There is no longer a requirement that successive transaction
149  * ids be 2 apart for separator generation.
150  */
151 static hammer_tid_t
152 hammer_alloc_tid(hammer_mount_t hmp, int count)
153 {
154 	hammer_tid_t tid;
155 
156 	if (hmp->master_id < 0) {
157 		tid = hmp->next_tid + 1;
158 		hmp->next_tid = tid + count;
159 	} else {
160 		tid = (hmp->next_tid + HAMMER_MAX_MASTERS) &
161 		      ~(hammer_tid_t)(HAMMER_MAX_MASTERS - 1);
162 		hmp->next_tid = tid + count * HAMMER_MAX_MASTERS;
163 		tid |= hmp->master_id;
164 	}
165 	if (tid >= 0xFFFFFFFFFF000000ULL)
166 		panic("hammer_start_transaction: Ran out of TIDs!");
167 	if (hammer_debug_tid)
168 		kprintf("alloc_tid %016llx\n", (long long)tid);
169 	return(tid);
170 }
171 
172 /*
173  * Allocate an object id.
174  *
175  * We use the upper OBJID_CACHE_BITS bits of the namekey to try to match
176  * the low bits of the objid we allocate.
177  */
178 hammer_tid_t
179 hammer_alloc_objid(hammer_mount_t hmp, hammer_inode_t dip, int64_t namekey)
180 {
181 	hammer_objid_cache_t ocp;
182 	hammer_tid_t tid;
183 	int incluster;
184 	u_int32_t n;
185 
186 	while ((ocp = dip->objid_cache) == NULL) {
187 		if (hmp->objid_cache_count < OBJID_CACHE_SIZE) {
188 			ocp = kmalloc(sizeof(*ocp), hmp->m_misc,
189 				      M_WAITOK|M_ZERO);
190 			ocp->base_tid = hammer_alloc_tid(hmp,
191 							OBJID_CACHE_BULK * 2);
192 			ocp->base_tid += OBJID_CACHE_BULK_MASK64;
193 			ocp->base_tid &= ~OBJID_CACHE_BULK_MASK64;
194 			TAILQ_INSERT_HEAD(&hmp->objid_cache_list, ocp, entry);
195 			++hmp->objid_cache_count;
196 			/* may have blocked, recheck */
197 			if (dip->objid_cache == NULL) {
198 				dip->objid_cache = ocp;
199 				ocp->dip = dip;
200 			}
201 		} else {
202 			/*
203 			 * Steal one from another directory?
204 			 *
205 			 * Throw away ocp's that are more then half full, they
206 			 * aren't worth stealing.
207 			 */
208 			ocp = TAILQ_FIRST(&hmp->objid_cache_list);
209 			if (ocp->dip)
210 				ocp->dip->objid_cache = NULL;
211 			if (ocp->count >= OBJID_CACHE_BULK / 2) {
212 				--hmp->objid_cache_count;
213 				kfree(ocp, hmp->m_misc);
214 			} else {
215 				dip->objid_cache = ocp;
216 				ocp->dip = dip;
217 			}
218 		}
219 	}
220 	TAILQ_REMOVE(&hmp->objid_cache_list, ocp, entry);
221 
222 	/*
223 	 * Allocate a bit based on our namekey for the low bits of our
224 	 * objid.
225 	 */
226 	incluster = (hmp->master_id >= 0);
227 	n = (namekey >> (63 - OBJID_CACHE_BULK_BITS)) & OBJID_CACHE_BULK_MASK;
228 	n = ocp_allocbit(ocp, n);
229 	tid = ocp->base_tid + n;
230 
231 #if 0
232 	/*
233 	 * The TID is incremented by 1 or by 16 depending what mode the
234 	 * mount is operating in.
235 	 */
236 	ocp->next_tid += (hmp->master_id < 0) ? 1 : HAMMER_MAX_MASTERS;
237 #endif
238 	if (ocp->count >= OBJID_CACHE_BULK / 2) {
239 		dip->objid_cache = NULL;
240 		--hmp->objid_cache_count;
241 		ocp->dip = NULL;
242 		kfree(ocp, hmp->m_misc);
243 	} else {
244 		TAILQ_INSERT_TAIL(&hmp->objid_cache_list, ocp, entry);
245 	}
246 	return(tid);
247 }
248 
249 /*
250  * Allocate a bit starting with bit n.  Wrap if necessary.
251  *
252  * This routine is only ever called if a bit is available somewhere
253  * in the bitmap.
254  */
255 static u_int32_t
256 ocp_allocbit(hammer_objid_cache_t ocp, u_int32_t n)
257 {
258 	u_int32_t n0;
259 
260 	n0 = (n >> 5) & 31;
261 	n &= 31;
262 
263 	while (ocp->bm1[n0] & (1 << n)) {
264 		if (ocp->bm0 & (1 << n0)) {
265 			n0 = (n0 + 1) & 31;
266 			n = 0;
267 		} else if (++n == 32) {
268 			n0 = (n0 + 1) & 31;
269 			n = 0;
270 		}
271 	}
272 	++ocp->count;
273 	ocp->bm1[n0] |= 1 << n;
274 	if (ocp->bm1[n0] == 0xFFFFFFFFU)
275 		ocp->bm0 |= 1 << n0;
276 	return((n0 << 5) + n);
277 }
278 
279 void
280 hammer_clear_objid(hammer_inode_t dip)
281 {
282 	hammer_objid_cache_t ocp;
283 
284 	if ((ocp = dip->objid_cache) != NULL) {
285 		dip->objid_cache = NULL;
286 		ocp->dip = NULL;
287 		TAILQ_REMOVE(&dip->hmp->objid_cache_list, ocp, entry);
288 		TAILQ_INSERT_HEAD(&dip->hmp->objid_cache_list, ocp, entry);
289 	}
290 }
291 
292 void
293 hammer_destroy_objid_cache(hammer_mount_t hmp)
294 {
295 	hammer_objid_cache_t ocp;
296 
297 	while ((ocp = TAILQ_FIRST(&hmp->objid_cache_list)) != NULL) {
298 		TAILQ_REMOVE(&hmp->objid_cache_list, ocp, entry);
299 		if (ocp->dip)
300 			ocp->dip->objid_cache = NULL;
301 		kfree(ocp, hmp->m_misc);
302 	}
303 }
304 
305