release/src-rt-6.x/linux/linux-2.6/fs/gfs2/daemon.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2006 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 version 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 <linux/gfs2_ondisk.h>
  18 #include <linux/lm_interface.h>
  19
  20 #include "gfs2.h"
  21 #include "incore.h"
  22 #include "daemon.h"
  23 #include "glock.h"
  24 #include "log.h"
  25 #include "quota.h"
  26 #include "recovery.h"
  27 #include "super.h"
  28 #include "util.h"
  29
  30 /* This uses schedule_timeout() instead of msleep() because it's good for
  31    the daemons to wake up more often than the timeout when unmounting so
  32    the user's unmount doesn't sit there forever.
  33
  34    The kthread functions used to start these daemons block and flush signals. */
  35
  36 /**
  37  * gfs2_scand - Look for cached glocks and inodes to toss from memory
  38  * @sdp: Pointer to GFS2 superblock
  39  *
  40  * One of these daemons runs, finding candidates to add to sd_reclaim_list.
  41  * See gfs2_glockd()
  42  */
  43
  44 int gfs2_scand(void *data)
  45 {
  46         struct gfs2_sbd *sdp = data;
  47         unsigned long t;
  48
  49         while (!kthread_should_stop()) {
  50                 gfs2_scand_internal(sdp);
  51                 t = gfs2_tune_get(sdp, gt_scand_secs) * HZ;
  52                 schedule_timeout_interruptible(t);
  53         }
  54
  55         return 0;
  56 }
  57
  58 /**
  59  * gfs2_glockd - Reclaim unused glock structures
  60  * @sdp: Pointer to GFS2 superblock
  61  *
  62  * One or more of these daemons run, reclaiming glocks on sd_reclaim_list.
  63  * Number of daemons can be set by user, with num_glockd mount option.
  64  */
  65
  66 int gfs2_glockd(void *data)
  67 {
  68         struct gfs2_sbd *sdp = data;
  69
  70         while (!kthread_should_stop()) {
  71                 while (atomic_read(&sdp->sd_reclaim_count))
  72                         gfs2_reclaim_glock(sdp);
  73
  74                 wait_event_interruptible(sdp->sd_reclaim_wq,
  75                                          (atomic_read(&sdp->sd_reclaim_count) ||
  76                                          kthread_should_stop()));
  77         }
  78
  79         return 0;
  80 }
  81
  82 /**
  83  * gfs2_recoverd - Recover dead machine's journals
  84  * @sdp: Pointer to GFS2 superblock
  85  *
  86  */
  87
  88 int gfs2_recoverd(void *data)
  89 {
  90         struct gfs2_sbd *sdp = data;
  91         unsigned long t;
  92
  93         while (!kthread_should_stop()) {
  94                 gfs2_check_journals(sdp);
  95                 t = gfs2_tune_get(sdp,  gt_recoverd_secs) * HZ;
  96                 schedule_timeout_interruptible(t);
  97         }
  98
  99         return 0;
 100 }
 101
 102 /**
 103  * gfs2_logd - Update log tail as Active Items get flushed to in-place blocks
 104  * @sdp: Pointer to GFS2 superblock
 105  *
 106  * Also, periodically check to make sure that we're using the most recent
 107  * journal index.
 108  */
 109
 110 int gfs2_logd(void *data)
 111 {
 112         struct gfs2_sbd *sdp = data;
 113         struct gfs2_holder ji_gh;
 114         unsigned long t;
 115         int need_flush;
 116
 117         while (!kthread_should_stop()) {
 118                 /* Advance the log tail */
 119
 120                 t = sdp->sd_log_flush_time +
 121                     gfs2_tune_get(sdp, gt_log_flush_secs) * HZ;
 122
 123                 gfs2_ail1_empty(sdp, DIO_ALL);
 124                 gfs2_log_lock(sdp);
 125                 need_flush = sdp->sd_log_num_buf > gfs2_tune_get(sdp, gt_incore_log_blocks);
 126                 gfs2_log_unlock(sdp);
 127                 if (need_flush || time_after_eq(jiffies, t)) {
 128                         gfs2_log_flush(sdp, NULL);
 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 = 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