[PATCH] [11/13] quota-11-sync

Implemented proper syncing of dquots - ie. also global information
about quota files are synced. We find info to sync by walking through
all superblocks...

fs/dquot.c

@@ -368,12 +368,13 @@ static void invalidate_dquots(struct super_block *sb, int type)
 	}
 }
 
-int sync_dquots(struct super_block *sb, int type)
+static int vfs_quota_sync(struct super_block *sb, int type)
 {
 	struct list_head *head;
 	struct dquot *dquot;
+	struct quota_info *dqopt = sb_dqopt(sb);
+	int cnt;
 
-	lock_kernel();
 restart:
 	list_for_each(head, &inuse_list) {
 		dquot = list_entry(head, struct dquot, dq_inuse);
@@ -396,12 +397,64 @@ int sync_dquots(struct super_block *sb, int type)
 		dqput(dquot);
 		goto restart;
 	}
-	/* FIXME: Here we should also sync all file info */
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+		if ((cnt == type || type == -1) && sb_has_quota_enabled(sb, cnt))
+			dqopt->info[cnt].dqi_flags &= ~DQF_ANY_DQUOT_DIRTY;
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+		if ((cnt == type || type == -1) && sb_has_quota_enabled(sb, cnt) && info_dirty(&dqopt->info[cnt]))
+			dqopt->ops[cnt]->write_file_info(sb, cnt);
 	dqstats.syncs++;
-	unlock_kernel();
 	return 0;
 }
 
+static struct super_block *get_super_to_sync(int type)
+{
+	struct list_head *head;
+	int cnt, dirty;
+
+restart:
+	spin_lock(&sb_lock);
+	list_for_each(head, &super_blocks) {
+		struct super_block *sb = list_entry(head, struct super_block, s_list);
+
+		for (cnt = 0, dirty = 0; cnt < MAXQUOTAS; cnt++)
+			if ((type == cnt || type == -1) && sb_has_quota_enabled(sb, cnt)
+			    && sb_dqopt(sb)->info[cnt].dqi_flags & DQF_ANY_DQUOT_DIRTY)
+				dirty = 1;
+		if (!dirty)
+			continue;
+		sb->s_count++;
+		spin_unlock(&sb_lock);
+		down_read(&sb->s_umount);
+		if (!sb->s_root) {
+			drop_super(sb);
+			goto restart;
+		}
+		return sb;
+	}
+	spin_unlock(&sb_lock);
+	return NULL;
+}
+
+void sync_dquots(struct super_block *sb, int type)
+{
+	if (sb) {
+		lock_kernel();
+		if (sb->s_qcop->quota_sync)
+			sb->s_qcop->quota_sync(sb, type);
+		unlock_kernel();
+	}
+	else {
+		while ((sb = get_super_to_sync(type))) {
+			lock_kernel();
+			if (sb->s_qcop->quota_sync)
+				sb->s_qcop->quota_sync(sb, type);
+			unlock_kernel();
+			drop_super(sb);
+		}
+	}
+}
+
 /* Free unused dquots from cache */
 static void prune_dqcache(int count)
 {
@@ -1212,7 +1265,7 @@ int vfs_quota_off(struct super_block *sb, int type)
 		/* Note: these are blocking operations */
 		remove_dquot_ref(sb, cnt);
 		invalidate_dquots(sb, cnt);
-                if (info_dirty(&dqopt->info[cnt]))
+		if (info_dirty(&dqopt->info[cnt]))
 			dqopt->ops[cnt]->write_file_info(sb, cnt);
 		if (dqopt->ops[cnt]->free_file_info)
 			dqopt->ops[cnt]->free_file_info(sb, cnt);
@@ -1291,11 +1344,6 @@ int vfs_quota_on(struct super_block *sb, int type, int format_id, char *path)
 	return error; 
 }
 
-int vfs_quota_sync(struct super_block *sb, int type)
-{
-	return sync_dquots(sb, type);
-}
-
 /* Generic routine for getting common part of quota structure */
 static void do_get_dqblk(struct dquot *dquot, struct if_dqblk *di)
 {

include/linux/fs.h

@@ -617,18 +617,6 @@ struct nameidata {
 	struct vfsmount *old_mnt;
 };
 
-#define DQUOT_USR_ENABLED	0x01		/* User diskquotas enabled */
-#define DQUOT_GRP_ENABLED	0x02		/* Group diskquotas enabled */
-
-struct quota_info {
-	unsigned int flags;			/* Flags for diskquotas on this device */
-	struct semaphore dqio_sem;		/* lock device while I/O in progress */
-	struct semaphore dqoff_sem;		/* serialize quota_off() and quota_on() on device */
-	struct file *files[MAXQUOTAS];		/* fp's to quotafiles */
-	struct mem_dqinfo info[MAXQUOTAS];	/* Information for each quota type */
-	struct quota_format_ops *ops[MAXQUOTAS];	/* Operations for each type */
-};
-
 /*
  *	Umount options
  */

include/linux/quota.h

@@ -170,6 +170,7 @@ struct mem_dqinfo {
 
 #define DQF_MASK 0xffff		/* Mask for format specific flags */
 #define DQF_INFO_DIRTY 0x10000  /* Is info dirty? */
+#define DQF_ANY_DQUOT_DIRTY 0x20000	/* Is any dquot dirty? */
 
 extern inline void mark_info_dirty(struct mem_dqinfo *info)
 {
@@ -178,6 +179,9 @@ extern inline void mark_info_dirty(struct mem_dqinfo *info)
 
 #define info_dirty(info) ((info)->dqi_flags & DQF_INFO_DIRTY)
 
+#define info_any_dirty(info) ((info)->dqi_flags & DQF_INFO_DIRTY ||\
+			      (info)->dqi_flags & DQF_ANY_DQUOT_DIRTY)
+
 #define sb_dqopt(sb) (&(sb)->s_dquot)
 
 extern int nr_dquots, nr_free_dquots;
@@ -224,13 +228,6 @@ struct dquot {
 	struct mem_dqblk dq_dqb;	/* Diskquota usage */
 };
 
-extern inline void mark_dquot_dirty(struct dquot *dquot)
-{
-	dquot->dq_flags |= DQ_MOD;
-}
-
-#define dquot_dirty(dquot) ((dquot)->dq_flags & DQ_MOD)
-
 #define NODQUOT (struct dquot *)NULL
 
 #define QUOTA_OK          0
@@ -279,6 +276,26 @@ struct quota_format_type {
 	struct quota_format_type *qf_next;
 };
 
+#define DQUOT_USR_ENABLED	0x01		/* User diskquotas enabled */
+#define DQUOT_GRP_ENABLED	0x02		/* Group diskquotas enabled */
+
+struct quota_info {
+	unsigned int flags;			/* Flags for diskquotas on this device */
+	struct semaphore dqio_sem;		/* lock device while I/O in progress */
+	struct semaphore dqoff_sem;		/* serialize quota_off() and quota_on() on device */
+	struct file *files[MAXQUOTAS];		/* fp's to quotafiles */
+	struct mem_dqinfo info[MAXQUOTAS];	/* Information for each quota type */
+	struct quota_format_ops *ops[MAXQUOTAS];	/* Operations for each type */
+};
+
+/* Inline would be better but we need to dereference super_block which is not defined yet */
+#define mark_dquot_dirty(dquot) do {\
+	dquot->dq_flags |= DQ_MOD;\
+	sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_flags |= DQF_ANY_DQUOT_DIRTY;\
+} while (0)
+
+#define dquot_dirty(dquot) ((dquot)->dq_flags & DQ_MOD)
+
 static inline int is_enabled(struct quota_info *dqopt, int type)
 {
 	switch (type) {

include/linux/quotaops.h

@@ -20,7 +20,7 @@
 /*
  * declaration of quota_function calls in kernel.
  */
-extern int sync_dquots(kdev_t dev, int type);
+extern void sync_dquots(struct super_block *sb, int type);
 
 extern void dquot_initialize(struct inode *inode, int type);
 extern void dquot_drop(struct inode *inode);