From 12c77527e4138bc3b17d17b0e0c909e4fc84924f Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Mon, 20 Oct 2008 17:05:00 +0200 Subject: quota: Implement function for scanning active dquots OCFS2 needs to scan all active dquots once in a while and sync quota information among cluster nodes. Provide a helper function for it so that it does not have to reimplement internally a list which VFS already has. Moreover this function is probably going to be useful for other clustered filesystems if they decide to use VFS quotas. Signed-off-by: Jan Kara Signed-off-by: Mark Fasheh --- fs/dquot.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) (limited to 'fs') diff --git a/fs/dquot.c b/fs/dquot.c index ae8fd9e645c..075dc76904e 100644 --- a/fs/dquot.c +++ b/fs/dquot.c @@ -476,6 +476,41 @@ restart: spin_unlock(&dq_list_lock); } +/* Call callback for every active dquot on given filesystem */ +int dquot_scan_active(struct super_block *sb, + int (*fn)(struct dquot *dquot, unsigned long priv), + unsigned long priv) +{ + struct dquot *dquot, *old_dquot = NULL; + int ret = 0; + + mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); + spin_lock(&dq_list_lock); + list_for_each_entry(dquot, &inuse_list, dq_inuse) { + if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) + continue; + if (dquot->dq_sb != sb) + continue; + /* Now we have active dquot so we can just increase use count */ + atomic_inc(&dquot->dq_count); + dqstats.lookups++; + spin_unlock(&dq_list_lock); + dqput(old_dquot); + old_dquot = dquot; + ret = fn(dquot, priv); + if (ret < 0) + goto out; + spin_lock(&dq_list_lock); + /* We are safe to continue now because our dquot could not + * be moved out of the inuse list while we hold the reference */ + } + spin_unlock(&dq_list_lock); +out: + dqput(old_dquot); + mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); + return ret; +} + int vfs_quota_sync(struct super_block *sb, int type) { struct list_head *dirty; @@ -2318,6 +2353,7 @@ EXPORT_SYMBOL(vfs_quota_on_path); EXPORT_SYMBOL(vfs_quota_on_mount); EXPORT_SYMBOL(vfs_quota_disable); EXPORT_SYMBOL(vfs_quota_off); +EXPORT_SYMBOL(dquot_scan_active); EXPORT_SYMBOL(vfs_quota_sync); EXPORT_SYMBOL(vfs_get_dqinfo); EXPORT_SYMBOL(vfs_set_dqinfo); -- cgit v1.2.3-70-g09d2