[GFS2] The core of GFS2
[linux-2.6.git] / fs / gfs2 / daemon.c
1 /*
2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
3  * Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
4  *
5  * This copyrighted material is made available to anyone wishing to use,
6  * modify, copy, or redistribute it subject to the terms and conditions
7  * of the GNU General Public License v.2.
8  */
9
10 #include <linux/sched.h>
11 #include <linux/slab.h>
12 #include <linux/spinlock.h>
13 #include <linux/completion.h>
14 #include <linux/buffer_head.h>
15 #include <linux/kthread.h>
16 #include <linux/delay.h>
17 #include <asm/semaphore.h>
18
19 #include "gfs2.h"
20 #include "daemon.h"
21 #include "glock.h"
22 #include "log.h"
23 #include "quota.h"
24 #include "recovery.h"
25 #include "super.h"
26 #include "unlinked.h"
27
28 /* This uses schedule_timeout() instead of msleep() because it's good for
29    the daemons to wake up more often than the timeout when unmounting so
30    the user's unmount doesn't sit there forever.
31    
32    The kthread functions used to start these daemons block and flush signals. */
33
34 /**
35  * gfs2_scand - Look for cached glocks and inodes to toss from memory
36  * @sdp: Pointer to GFS2 superblock
37  *
38  * One of these daemons runs, finding candidates to add to sd_reclaim_list.
39  * See gfs2_glockd()
40  */
41
42 int gfs2_scand(void *data)
43 {
44         struct gfs2_sbd *sdp = (struct gfs2_sbd *)data;
45         unsigned long t;
46
47         while (!kthread_should_stop()) {
48                 gfs2_scand_internal(sdp);
49                 t = gfs2_tune_get(sdp, gt_scand_secs) * HZ;
50                 schedule_timeout_interruptible(t);
51         }
52
53         return 0;
54 }
55
56 /**
57  * gfs2_glockd - Reclaim unused glock structures
58  * @sdp: Pointer to GFS2 superblock
59  *
60  * One or more of these daemons run, reclaiming glocks on sd_reclaim_list.
61  * Number of daemons can be set by user, with num_glockd mount option.
62  */
63
64 int gfs2_glockd(void *data)
65 {
66         struct gfs2_sbd *sdp = (struct gfs2_sbd *)data;
67         DECLARE_WAITQUEUE(wait_chan, current);
68
69         while (!kthread_should_stop()) {
70                 while (atomic_read(&sdp->sd_reclaim_count))
71                         gfs2_reclaim_glock(sdp);
72
73                 set_current_state(TASK_INTERRUPTIBLE);
74                 add_wait_queue(&sdp->sd_reclaim_wq, &wait_chan);
75                 if (!atomic_read(&sdp->sd_reclaim_count) &&
76                     !kthread_should_stop())
77                         schedule();
78                 remove_wait_queue(&sdp->sd_reclaim_wq, &wait_chan);
79                 set_current_state(TASK_RUNNING);
80         }
81
82         return 0;
83 }
84
85 /**
86  * gfs2_recoverd - Recover dead machine's journals
87  * @sdp: Pointer to GFS2 superblock
88  *
89  */
90
91 int gfs2_recoverd(void *data)
92 {
93         struct gfs2_sbd *sdp = (struct gfs2_sbd *)data;
94         unsigned long t;
95
96         while (!kthread_should_stop()) {
97                 gfs2_check_journals(sdp);
98                 t = gfs2_tune_get(sdp,  gt_recoverd_secs) * HZ;
99                 schedule_timeout_interruptible(t);
100         }
101
102         return 0;
103 }
104
105 /**
106  * gfs2_logd - Update log tail as Active Items get flushed to in-place blocks
107  * @sdp: Pointer to GFS2 superblock
108  *
109  * Also, periodically check to make sure that we're using the most recent
110  * journal index.
111  */
112
113 int gfs2_logd(void *data)
114 {
115         struct gfs2_sbd *sdp = (struct gfs2_sbd *)data;
116         struct gfs2_holder ji_gh;
117         unsigned long t;
118
119         while (!kthread_should_stop()) {
120                 /* Advance the log tail */
121
122                 t = sdp->sd_log_flush_time +
123                     gfs2_tune_get(sdp, gt_log_flush_secs) * HZ;
124
125                 gfs2_ail1_empty(sdp, DIO_ALL);
126
127                 if (time_after_eq(jiffies, t)) {
128                         gfs2_log_flush(sdp);
129                         sdp->sd_log_flush_time = jiffies;
130                 }
131
132                 /* Check for latest journal index */
133
134                 t = sdp->sd_jindex_refresh_time +
135                     gfs2_tune_get(sdp, gt_jindex_refresh_secs) * HZ;
136
137                 if (time_after_eq(jiffies, t)) {
138                         if (!gfs2_jindex_hold(sdp, &ji_gh))
139                                 gfs2_glock_dq_uninit(&ji_gh);
140                         sdp->sd_jindex_refresh_time = jiffies;
141                 }
142
143                 t = gfs2_tune_get(sdp, gt_logd_secs) * HZ;
144                 schedule_timeout_interruptible(t);
145         }
146
147         return 0;
148 }
149
150 /**
151  * gfs2_quotad - Write cached quota changes into the quota file
152  * @sdp: Pointer to GFS2 superblock
153  *
154  */
155
156 int gfs2_quotad(void *data)
157 {
158         struct gfs2_sbd *sdp = (struct gfs2_sbd *)data;
159         unsigned long t;
160         int error;
161
162         while (!kthread_should_stop()) {
163                 /* Update the master statfs file */
164
165                 t = sdp->sd_statfs_sync_time +
166                     gfs2_tune_get(sdp, gt_statfs_quantum) * HZ;
167
168                 if (time_after_eq(jiffies, t)) {
169                         error = gfs2_statfs_sync(sdp);
170                         if (error &&
171                             error != -EROFS &&
172                             !test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
173                                 fs_err(sdp, "quotad: (1) error=%d\n", error);
174                         sdp->sd_statfs_sync_time = jiffies;
175                 }
176
177                 /* Update quota file */
178
179                 t = sdp->sd_quota_sync_time +
180                     gfs2_tune_get(sdp, gt_quota_quantum) * HZ;
181
182                 if (time_after_eq(jiffies, t)) {
183                         error = gfs2_quota_sync(sdp);
184                         if (error &&
185                             error != -EROFS &&
186                             !test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
187                                 fs_err(sdp, "quotad: (2) error=%d\n", error);
188                         sdp->sd_quota_sync_time = jiffies;
189                 }
190
191                 gfs2_quota_scan(sdp);
192
193                 t = gfs2_tune_get(sdp, gt_quotad_secs) * HZ;
194                 schedule_timeout_interruptible(t);
195         }
196
197         return 0;
198 }
199
200 /**
201  * gfs2_inoded - Deallocate unlinked inodes
202  * @sdp: Pointer to GFS2 superblock
203  *
204  */
205
206 int gfs2_inoded(void *data)
207 {
208         struct gfs2_sbd *sdp = (struct gfs2_sbd *)data;
209         unsigned long t;
210         int error;
211
212         while (!kthread_should_stop()) {
213                 error = gfs2_unlinked_dealloc(sdp);
214                 if (error &&
215                     error != -EROFS &&
216                     !test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
217                         fs_err(sdp, "inoded: error = %d\n", error);
218
219                 t = gfs2_tune_get(sdp, gt_inoded_secs) * HZ;
220                 schedule_timeout_interruptible(t);
221         }
222
223         return 0;
224 }
225