hammer2 - more indirect block work, add advlock
[dragonfly.git] / sys / vfs / hammer2 / hammer2_inode.c
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1/*
2 * Copyright (c) 2011-2012 The DragonFly Project. All rights reserved.
3 *
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@dragonflybsd.org>
6 * by Venkatesh Srinivas <vsrinivas@dragonflybsd.org>
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in
16 * the documentation and/or other materials provided with the
17 * distribution.
18 * 3. Neither the name of The DragonFly Project nor the names of its
19 * contributors may be used to endorse or promote products derived
20 * from this software without specific, prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
26 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
28 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
29 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
30 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
31 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
32 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35#include <sys/cdefs.h>
36#include <sys/cdefs.h>
37#include <sys/param.h>
38#include <sys/systm.h>
39#include <sys/types.h>
40#include <sys/lock.h>
41#include <sys/uuid.h>
42
43#include "hammer2.h"
44
45/*
46 * Adding a ref to an inode is only legal if the inode already has at least
47 * one ref.
48 */
49void
50hammer2_inode_ref(hammer2_inode_t *ip)
51{
5c23d7f1 52 hammer2_chain_ref(ip->hmp, &ip->chain);
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53}
54
55/*
56 * Drop an inode reference, freeing the inode when the last reference goes
57 * away.
58 */
59void
60hammer2_inode_drop(hammer2_inode_t *ip)
61{
5c23d7f1 62 hammer2_chain_drop(ip->hmp, &ip->chain);
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63}
64
65/*
66 * Get the vnode associated with the given inode, allocating the vnode if
67 * necessary.
68 *
69 * Great care must be taken to avoid deadlocks and vnode acquisition/reclaim
70 * races.
71 *
72 * The vnode will be returned exclusively locked and referenced. The
73 * reference on the vnode prevents it from being reclaimed.
74 *
75 * The inode (ip) must be referenced by the caller and not locked to avoid
76 * it getting ripped out from under us or deadlocked.
77 */
78struct vnode *
79hammer2_igetv(hammer2_inode_t *ip, int *errorp)
80{
81 struct vnode *vp;
82 hammer2_mount_t *hmp;
83
84 hmp = ip->hmp;
85 *errorp = 0;
86
87 for (;;) {
88 /*
89 * Attempt to reuse an existing vnode assignment. It is
90 * possible to race a reclaim so the vget() may fail. The
91 * inode must be unlocked during the vget() to avoid a
92 * deadlock against a reclaim.
93 */
94 vp = ip->vp;
95 if (vp) {
96 /*
97 * Lock the inode and check for a reclaim race
98 */
99 hammer2_inode_lock_ex(ip);
100 if (ip->vp != vp) {
101 hammer2_inode_unlock_ex(ip);
102 continue;
103 }
104
105 /*
106 * Inode must be unlocked during the vget() to avoid
107 * possible deadlocks, vnode is held to prevent
108 * destruction during the vget(). The vget() can
109 * still fail if we lost a reclaim race on the vnode.
110 */
111 vhold_interlocked(vp);
112 hammer2_inode_unlock_ex(ip);
113 if (vget(vp, LK_EXCLUSIVE)) {
114 vdrop(vp);
115 continue;
116 }
117 vdrop(vp);
118 /* vp still locked and ref from vget */
119 *errorp = 0;
120 break;
121 }
122
123 /*
124 * No vnode exists, allocate a new vnode. Beware of
125 * allocation races. This function will return an
126 * exclusively locked and referenced vnode.
127 */
128 *errorp = getnewvnode(VT_HAMMER2, H2TOMP(hmp), &vp, 0, 0);
129 if (*errorp) {
130 vp = NULL;
131 break;
132 }
133
134 /*
135 * Lock the inode and check for an allocation race.
136 */
137 hammer2_inode_lock_ex(ip);
138 if (ip->vp != NULL) {
139 vp->v_type = VBAD;
140 vx_put(vp);
141 hammer2_inode_unlock_ex(ip);
142 continue;
143 }
144
5c23d7f1 145 switch (ip->ip_data.type) {
df9ea374 146 case HAMMER2_OBJTYPE_DIRECTORY:
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147 vp->v_type = VDIR;
148 break;
df9ea374 149 case HAMMER2_OBJTYPE_REGFILE:
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150 vp->v_type = VREG;
151 vinitvmio(vp, 0, HAMMER2_LBUFSIZE,
5c23d7f1 152 (int)ip->ip_data.size & HAMMER2_LBUFMASK);
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153 break;
154 /* XXX FIFO */
155 default:
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156 panic("hammer2: unhandled objtype %d",
157 ip->ip_data.type);
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158 break;
159 }
160
df9ea374 161 if (ip == hmp->iroot)
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162 vsetflags(vp, VROOT);
163
164 vp->v_data = ip;
165 ip->vp = vp;
9c2e0de0 166 hammer2_chain_ref(hmp, &ip->chain); /* vp association */
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167 hammer2_inode_unlock_ex(ip);
168 break;
169 }
170
171 /*
172 * Return non-NULL vp and *errorp == 0, or NULL vp and *errorp != 0.
173 */
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174 if (hammer2_debug & 0x0002) {
175 kprintf("igetv vp %p refs %d aux %d\n",
176 vp, vp->v_sysref.refcnt, vp->v_auxrefs);
177 }
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178 return (vp);
179}
180
181/*
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182 * Create a new inode in the specified directory using the vattr to
183 * figure out the type of inode.
7cfa8da5 184 *
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185 * If no error occurs the new inode with its chain locked is returned in
186 * *nipp, otherwise an error is returned and *nipp is set to NULL.
7cfa8da5 187 */
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188int
189hammer2_create_inode(hammer2_mount_t *hmp,
190 struct vattr *vap, struct ucred *cred,
191 hammer2_inode_t *dip,
192 const uint8_t *name, size_t name_len,
193 hammer2_inode_t **nipp)
7cfa8da5 194{
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195 hammer2_chain_t *chain;
196 hammer2_chain_t *parent;
197 hammer2_inode_t *nip;
198 hammer2_key_t lhc;
199 int error;
7cfa8da5 200
37494cab 201 lhc = hammer2_dirhash(name, name_len);
7cfa8da5 202
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203 /*
204 * Locate the inode or indirect block to create the new
205 * entry in. At the same time check for key collisions
206 * and iterate until we don't get one.
207 */
208 parent = &dip->chain;
209 hammer2_chain_ref(hmp, parent);
210 hammer2_chain_lock(hmp, parent);
7cfa8da5 211
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212 error = 0;
213 while (error == 0) {
c667909f 214 chain = hammer2_chain_lookup(hmp, &parent, lhc, lhc, 0);
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215 if (chain == NULL)
216 break;
217 if ((lhc & HAMMER2_DIRHASH_LOMASK) == HAMMER2_DIRHASH_LOMASK)
218 error = ENOSPC;
219 hammer2_chain_put(hmp, chain);
220 chain = NULL;
221 ++lhc;
222 }
223 if (error == 0) {
37aa19df 224 chain = hammer2_chain_create(hmp, parent, lhc, 0,
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225 HAMMER2_BREF_TYPE_INODE,
226 HAMMER2_INODE_BYTES);
227 if (chain == NULL)
228 error = EIO;
229 }
230 hammer2_chain_put(hmp, parent);
7cfa8da5 231
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232 /*
233 * Handle the error case
234 */
235 if (error) {
236 KKASSERT(chain == NULL);
237 *nipp = NULL;
238 return (error);
239 }
7cfa8da5 240
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241 /*
242 * Set up the new inode
243 */
244 nip = chain->u.ip;
245 *nipp = nip;
7cfa8da5 246
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247 nip->ip_data.type = hammer2_get_obj_type(vap->va_type);
248 nip->ip_data.inum = hmp->voldata.alloc_tid++; /* XXX modify/lock */
249 nip->ip_data.version = HAMMER2_INODE_VERSION_ONE;
250 nip->ip_data.ctime = 0;
251 nip->ip_data.mtime = 0;
252 nip->ip_data.mode = vap->va_mode;
253 nip->ip_data.nlinks = 1;
254 /* uid, gid, etc */
232a50f9 255
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256 KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
257 bcopy(name, nip->ip_data.filename, name_len);
258 nip->ip_data.name_key = lhc;
259 nip->ip_data.name_len = name_len;
7cfa8da5 260
37494cab 261 return (0);
7cfa8da5 262}