- patches.fixes/patch-2.6.11-rc1: 2.6.11-rc1.

[linux-flexiantxendom0-3.2.10.git] / fs / quota.c

diff --git a/fs/quota.c b/fs/quota.c
index 57e4f26..d59ccf2 100644 (file)
--- a/fs/quota.c
+++ b/fs/quota.c
@@ -14,6 +14,7 @@
 #include <linux/smp_lock.h>
 #include <linux/security.h>
 #include <linux/syscalls.h>
+#include <linux/buffer_head.h>
 
 /* Check validity of quotactl */
 static int check_quotactl_valid(struct super_block *sb, int type, int cmd, qid_t id)
@@ -135,16 +136,54 @@ restart:
        return NULL;
 }
 
+static void quota_sync_sb(struct super_block *sb, int type)
+{
+       int cnt;
+       struct inode *discard[MAXQUOTAS];
+
+       sb->s_qcop->quota_sync(sb, type);
+       /* This is not very clever (and fast) but currently I don't know about
+        * any other simple way of getting quota data to disk and we must get
+        * them there for userspace to be visible... */
+       if (sb->s_op->sync_fs)
+               sb->s_op->sync_fs(sb, 1);
+       sync_blockdev(sb->s_bdev);
+
+       /* Now when everything is written we can discard the pagecache so
+        * that userspace sees the changes. We need i_sem and so we could
+        * not do it inside dqonoff_sem. Moreover we need to be carefull
+        * about races with quotaoff() (that is the reason why we have own
+        * reference to inode). */
+       down(&sb_dqopt(sb)->dqonoff_sem);
+       for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+               discard[cnt] = NULL;
+               if (type != -1 && cnt != type)
+                       continue;
+               if (!sb_has_quota_enabled(sb, cnt))
+                       continue;
+               discard[cnt] = igrab(sb_dqopt(sb)->files[cnt]);
+       }
+       up(&sb_dqopt(sb)->dqonoff_sem);
+       for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+               if (discard[cnt]) {
+                       down(&discard[cnt]->i_sem);
+                       truncate_inode_pages(&discard[cnt]->i_data, 0);
+                       up(&discard[cnt]->i_sem);
+                       iput(discard[cnt]);
+               }
+       }
+}
+
 void sync_dquots(struct super_block *sb, int type)
 {
        if (sb) {
                if (sb->s_qcop->quota_sync)
-                       sb->s_qcop->quota_sync(sb, type);
+                       quota_sync_sb(sb, type);
        }
        else {
-               while ((sb = get_super_to_sync(type)) != 0) {
+               while ((sb = get_super_to_sync(type)) != NULL) {
                        if (sb->s_qcop->quota_sync)
-                               sb->s_qcop->quota_sync(sb, type);
+                               quota_sync_sb(sb, type);
                        drop_super(sb);
                }
        }