xref: /openbmc/linux/fs/ocfs2/slot_map.c (revision e868d61272caa648214046a096e5a6bfc068dc8c)
1 /* -*- mode: c; c-basic-offset: 8; -*-
2  * vim: noexpandtab sw=8 ts=8 sts=0:
3  *
4  * slot_map.c
5  *
6  *
7  *
8  * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public
12  * License as published by the Free Software Foundation; either
13  * version 2 of the License, or (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18  * General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public
21  * License along with this program; if not, write to the
22  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23  * Boston, MA 021110-1307, USA.
24  */
25 
26 #include <linux/types.h>
27 #include <linux/slab.h>
28 #include <linux/highmem.h>
29 
30 #define MLOG_MASK_PREFIX ML_SUPER
31 #include <cluster/masklog.h>
32 
33 #include "ocfs2.h"
34 
35 #include "dlmglue.h"
36 #include "extent_map.h"
37 #include "heartbeat.h"
38 #include "inode.h"
39 #include "slot_map.h"
40 #include "super.h"
41 #include "sysfile.h"
42 
43 #include "buffer_head_io.h"
44 
45 static s16 __ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
46 				    s16 global);
47 static void __ocfs2_fill_slot(struct ocfs2_slot_info *si,
48 			      s16 slot_num,
49 			      s16 node_num);
50 
51 /* Use the slot information we've collected to create a map of mounted
52  * nodes. Should be holding an EX on super block. assumes slot info is
53  * up to date. Note that we call this *after* we find a slot, so our
54  * own node should be set in the map too... */
55 void ocfs2_populate_mounted_map(struct ocfs2_super *osb)
56 {
57 	int i;
58 	struct ocfs2_slot_info *si = osb->slot_info;
59 
60 	spin_lock(&si->si_lock);
61 
62 	for (i = 0; i < si->si_size; i++)
63 		if (si->si_global_node_nums[i] != OCFS2_INVALID_SLOT)
64 			ocfs2_node_map_set_bit(osb, &osb->mounted_map,
65 					      si->si_global_node_nums[i]);
66 
67 	spin_unlock(&si->si_lock);
68 }
69 
70 /* post the slot information on disk into our slot_info struct. */
71 void ocfs2_update_slot_info(struct ocfs2_slot_info *si)
72 {
73 	int i;
74 	__le16 *disk_info;
75 
76 	/* we don't read the slot block here as ocfs2_super_lock
77 	 * should've made sure we have the most recent copy. */
78 	spin_lock(&si->si_lock);
79 	disk_info = (__le16 *) si->si_bh->b_data;
80 
81 	for (i = 0; i < si->si_size; i++)
82 		si->si_global_node_nums[i] = le16_to_cpu(disk_info[i]);
83 
84 	spin_unlock(&si->si_lock);
85 }
86 
87 /* post the our slot info stuff into it's destination bh and write it
88  * out. */
89 int ocfs2_update_disk_slots(struct ocfs2_super *osb,
90 			    struct ocfs2_slot_info *si)
91 {
92 	int status, i;
93 	__le16 *disk_info = (__le16 *) si->si_bh->b_data;
94 
95 	spin_lock(&si->si_lock);
96 	for (i = 0; i < si->si_size; i++)
97 		disk_info[i] = cpu_to_le16(si->si_global_node_nums[i]);
98 	spin_unlock(&si->si_lock);
99 
100 	status = ocfs2_write_block(osb, si->si_bh, si->si_inode);
101 	if (status < 0)
102 		mlog_errno(status);
103 
104 	return status;
105 }
106 
107 /* try to find global node in the slot info. Returns
108  * OCFS2_INVALID_SLOT if nothing is found. */
109 static s16 __ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
110 				    s16 global)
111 {
112 	int i;
113 	s16 ret = OCFS2_INVALID_SLOT;
114 
115 	for(i = 0; i < si->si_num_slots; i++) {
116 		if (global == si->si_global_node_nums[i]) {
117 			ret = (s16) i;
118 			break;
119 		}
120 	}
121 	return ret;
122 }
123 
124 static s16 __ocfs2_find_empty_slot(struct ocfs2_slot_info *si)
125 {
126 	int i;
127 	s16 ret = OCFS2_INVALID_SLOT;
128 
129 	for(i = 0; i < si->si_num_slots; i++) {
130 		if (OCFS2_INVALID_SLOT == si->si_global_node_nums[i]) {
131 			ret = (s16) i;
132 			break;
133 		}
134 	}
135 	return ret;
136 }
137 
138 s16 ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
139 			   s16 global)
140 {
141 	s16 ret;
142 
143 	spin_lock(&si->si_lock);
144 	ret = __ocfs2_node_num_to_slot(si, global);
145 	spin_unlock(&si->si_lock);
146 	return ret;
147 }
148 
149 static void __ocfs2_fill_slot(struct ocfs2_slot_info *si,
150 			      s16 slot_num,
151 			      s16 node_num)
152 {
153 	BUG_ON(slot_num == OCFS2_INVALID_SLOT);
154 	BUG_ON(slot_num >= si->si_num_slots);
155 	BUG_ON((node_num != O2NM_INVALID_NODE_NUM) &&
156 	       (node_num >= O2NM_MAX_NODES));
157 
158 	si->si_global_node_nums[slot_num] = node_num;
159 }
160 
161 void ocfs2_clear_slot(struct ocfs2_slot_info *si,
162 		      s16 slot_num)
163 {
164 	spin_lock(&si->si_lock);
165 	__ocfs2_fill_slot(si, slot_num, OCFS2_INVALID_SLOT);
166 	spin_unlock(&si->si_lock);
167 }
168 
169 int ocfs2_init_slot_info(struct ocfs2_super *osb)
170 {
171 	int status, i;
172 	u64 blkno;
173 	struct inode *inode = NULL;
174 	struct buffer_head *bh = NULL;
175 	struct ocfs2_slot_info *si;
176 
177 	si = kzalloc(sizeof(struct ocfs2_slot_info), GFP_KERNEL);
178 	if (!si) {
179 		status = -ENOMEM;
180 		mlog_errno(status);
181 		goto bail;
182 	}
183 
184 	spin_lock_init(&si->si_lock);
185 	si->si_num_slots = osb->max_slots;
186 	si->si_size = OCFS2_MAX_SLOTS;
187 
188 	for(i = 0; i < si->si_num_slots; i++)
189 		si->si_global_node_nums[i] = OCFS2_INVALID_SLOT;
190 
191 	inode = ocfs2_get_system_file_inode(osb, SLOT_MAP_SYSTEM_INODE,
192 					    OCFS2_INVALID_SLOT);
193 	if (!inode) {
194 		status = -EINVAL;
195 		mlog_errno(status);
196 		goto bail;
197 	}
198 
199 	status = ocfs2_extent_map_get_blocks(inode, 0ULL, &blkno, NULL, NULL);
200 	if (status < 0) {
201 		mlog_errno(status);
202 		goto bail;
203 	}
204 
205 	status = ocfs2_read_block(osb, blkno, &bh, 0, inode);
206 	if (status < 0) {
207 		mlog_errno(status);
208 		goto bail;
209 	}
210 
211 	si->si_inode = inode;
212 	si->si_bh = bh;
213 	osb->slot_info = si;
214 bail:
215 	if (status < 0 && si)
216 		ocfs2_free_slot_info(si);
217 
218 	return status;
219 }
220 
221 void ocfs2_free_slot_info(struct ocfs2_slot_info *si)
222 {
223 	if (si->si_inode)
224 		iput(si->si_inode);
225 	if (si->si_bh)
226 		brelse(si->si_bh);
227 	kfree(si);
228 }
229 
230 int ocfs2_find_slot(struct ocfs2_super *osb)
231 {
232 	int status;
233 	s16 slot;
234 	struct ocfs2_slot_info *si;
235 
236 	mlog_entry_void();
237 
238 	si = osb->slot_info;
239 
240 	ocfs2_update_slot_info(si);
241 
242 	spin_lock(&si->si_lock);
243 	/* search for ourselves first and take the slot if it already
244 	 * exists. Perhaps we need to mark this in a variable for our
245 	 * own journal recovery? Possibly not, though we certainly
246 	 * need to warn to the user */
247 	slot = __ocfs2_node_num_to_slot(si, osb->node_num);
248 	if (slot == OCFS2_INVALID_SLOT) {
249 		/* if no slot yet, then just take 1st available
250 		 * one. */
251 		slot = __ocfs2_find_empty_slot(si);
252 		if (slot == OCFS2_INVALID_SLOT) {
253 			spin_unlock(&si->si_lock);
254 			mlog(ML_ERROR, "no free slots available!\n");
255 			status = -EINVAL;
256 			goto bail;
257 		}
258 	} else
259 		mlog(ML_NOTICE, "slot %d is already allocated to this node!\n",
260 		     slot);
261 
262 	__ocfs2_fill_slot(si, slot, osb->node_num);
263 	osb->slot_num = slot;
264 	spin_unlock(&si->si_lock);
265 
266 	mlog(0, "taking node slot %d\n", osb->slot_num);
267 
268 	status = ocfs2_update_disk_slots(osb, si);
269 	if (status < 0)
270 		mlog_errno(status);
271 
272 bail:
273 	mlog_exit(status);
274 	return status;
275 }
276 
277 void ocfs2_put_slot(struct ocfs2_super *osb)
278 {
279 	int status;
280 	struct ocfs2_slot_info *si = osb->slot_info;
281 
282 	if (!si)
283 		return;
284 
285 	ocfs2_update_slot_info(si);
286 
287 	spin_lock(&si->si_lock);
288 	__ocfs2_fill_slot(si, osb->slot_num, OCFS2_INVALID_SLOT);
289 	osb->slot_num = OCFS2_INVALID_SLOT;
290 	spin_unlock(&si->si_lock);
291 
292 	status = ocfs2_update_disk_slots(osb, si);
293 	if (status < 0) {
294 		mlog_errno(status);
295 		goto bail;
296 	}
297 
298 bail:
299 	osb->slot_info = NULL;
300 	ocfs2_free_slot_info(si);
301 }
302 
303