[PATCH] Locking in sync_old_buffers

Move BKL into the fs-specific write_super()'s.

Documentation/filesystems/Locking

@@ -110,7 +110,7 @@ put_inode:	no
 delete_inode:	no	
 clear_inode:	no	
 put_super:	yes	yes	maybe		(see below)
-write_super:	yes	yes	maybe		(see below)
+write_super:	no	yes	maybe		(see below)
 statfs:		yes	no	no
 remount_fs:	yes	yes	maybe		(see below)
 umount_begin:	yes	no	maybe		(see below)

fs/affs/super.c

@@ -38,7 +38,7 @@ static void
 affs_put_super(struct super_block *sb)
 {
 	struct affs_sb_info *sbi = AFFS_SB(sb);
-
+	lock_kernel();
 	pr_debug("AFFS: put_super()\n");
 
 	if (!(sb->s_flags & MS_RDONLY)) {
@@ -56,7 +56,7 @@ affs_put_super(struct super_block *sb)
 	affs_brelse(sbi->s_root_bh);
 	kfree(sbi);
 	sb->u.generic_sbp = NULL;
-
+	unlock_kernel();
 	return;
 }
 
@@ -65,7 +65,7 @@ affs_write_super(struct super_block *sb)
 {
 	int clean = 2;
 	struct affs_sb_info *sbi = AFFS_SB(sb);
-
+	lock_kernel();
 	if (!(sb->s_flags & MS_RDONLY)) {
 		//	if (sbi->s_bitmap[i].bm_bh) {
 		//		if (buffer_dirty(sbi->s_bitmap[i].bm_bh)) {
@@ -80,6 +80,7 @@ affs_write_super(struct super_block *sb)
 		sb->s_dirt = 0;
 
 	pr_debug("AFFS: write_super() at %lu, clean=%d\n", CURRENT_TIME, clean);
+	unlock_kernel();
 }
 
 static kmem_cache_t * affs_inode_cachep;

fs/bfs/inode.c

@@ -206,9 +206,11 @@ static int bfs_statfs(struct super_block *s, struct statfs *buf)
 
 static void bfs_write_super(struct super_block *s)
 {
+	lock_kernel();
 	if (!(s->s_flags & MS_RDONLY))
 		mark_buffer_dirty(BFS_SB(s)->si_sbh);
 	s->s_dirt = 0;
+	unlock_kernel();
 }
 
 static kmem_cache_t * bfs_inode_cachep;

fs/buffer.c

@@ -2612,10 +2612,8 @@ void __init buffer_init(unsigned long mempages)
 
 static void sync_old_buffers(unsigned long dummy)
 {
-	lock_kernel();
 	sync_unlocked_inodes();
 	sync_supers();
-	unlock_kernel();
 
 	for (;;) {
 		struct buffer_head *bh;

fs/ext2/super.c

@@ -754,7 +754,7 @@ static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
 void ext2_write_super (struct super_block * sb)
 {
 	struct ext2_super_block * es;
-
+	lock_kernel();
 	if (!(sb->s_flags & MS_RDONLY)) {
 		es = EXT2_SB(sb)->s_es;
 
@@ -768,6 +768,7 @@ void ext2_write_super (struct super_block * sb)
 			ext2_commit_super (sb, es);
 	}
 	sb->s_dirt = 0;
+	unlock_kernel();
 }
 
 int ext2_remount (struct super_block * sb, int * flags, char * data)

fs/ext3/super.c

@@ -501,7 +501,7 @@ static struct super_operations ext3_sops = {
 	put_inode:	ext3_put_inode,		/* BKL not held.  Don't need */
 	delete_inode:	ext3_delete_inode,	/* BKL not held.  We take it */
 	put_super:	ext3_put_super,		/* BKL held */
-	write_super:	ext3_write_super,	/* BKL held */
+	write_super:	ext3_write_super,	/* BKL not held. We take it. Needed? */
 	write_super_lockfs: ext3_write_super_lockfs, /* BKL not held. Take it */
 	unlockfs:	ext3_unlockfs,		/* BKL not held.  We take it */
 	statfs:		ext3_statfs,		/* BKL held */
@@ -1599,7 +1599,7 @@ MODULE_PARM_DESC(do_sync_supers, "Write superblocks synchronously");
 void ext3_write_super (struct super_block * sb)
 {
 	tid_t target;
-	
+	lock_kernel();	
 	if (down_trylock(&sb->s_lock) == 0)
 		BUG();		/* aviro detector */
 	sb->s_dirt = 0;
@@ -1610,6 +1610,7 @@ void ext3_write_super (struct super_block * sb)
 		log_wait_commit(EXT3_SB(sb)->s_journal, target);
 		lock_super(sb);
 	}
+	unlock_kernel();
 }
 
 /*

fs/hfs/super.c

@@ -146,9 +146,10 @@ static void hfs_read_inode(struct inode *inode)
 static void hfs_write_super(struct super_block *sb)
 {
 	struct hfs_mdb *mdb = HFS_SB(sb)->s_mdb;
-
+	lock_kernel();
 	/* is this a valid hfs superblock? */
 	if (!sb || sb->s_magic != HFS_SUPER_MAGIC) {
+		unlock_kernel();
 		return;
 	}
 
@@ -157,6 +158,7 @@ static void hfs_write_super(struct super_block *sb)
 		hfs_mdb_commit(mdb, 0);
 	}
 	sb->s_dirt = 0;
+	unlock_kernel();
 }
 
 /*

fs/jffs/inode-v23.c

@@ -1746,8 +1746,9 @@ void
 jffs_write_super(struct super_block *sb)
 {
 	struct jffs_control *c = (struct jffs_control *)sb->u.generic_sbp;
-
+	lock_kernel();
 	jffs_garbage_collect_trigger(c);
+	unlock_kernel();
 }
 
 static struct super_operations jffs_ops =

fs/jffs2/fs.c

@@ -320,16 +320,21 @@ int jffs2_remount_fs (struct super_block *sb, int *flags, char *data)
 void jffs2_write_super (struct super_block *sb)
 {
 	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
+
+	lock_kernel();
 	sb->s_dirt = 0;
 
-	if (sb->s_flags & MS_RDONLY)
+	if (sb->s_flags & MS_RDONLY) {
+		unlock_kernel();	
 		return;
+	}
 
 	D1(printk("jffs2_write_super(): flush_wbuf before gc-trigger\n"));
 	jffs2_flush_wbuf(c, 2);
 	jffs2_garbage_collect_trigger(c);
 	jffs2_erase_pending_blocks(c);
 	jffs2_mark_erased_blocks(c);
+	unlock_kernel();
 }
 
 

fs/qnx4/inode.c

@@ -72,8 +72,10 @@ static void qnx4_delete_inode(struct inode *inode)
 
 static void qnx4_write_super(struct super_block *sb)
 {
+	lock_kernel();
 	QNX4DEBUG(("qnx4: write_super\n"));
 	sb->s_dirt = 0;
+	unlock_kernel();
 }
 
 static void qnx4_write_inode(struct inode *inode, int unused)

fs/sysv/inode.c

@@ -33,6 +33,7 @@
 /* This is only called on sync() and umount(), when s_dirt=1. */
 static void sysv_write_super(struct super_block *sb)
 {
+	lock_kernel();
 	if (!(sb->s_flags & MS_RDONLY)) {
 		/* If we are going to write out the super block,
 		   then attach current time stamp.
@@ -46,6 +47,7 @@ static void sysv_write_super(struct super_block *sb)
 		mark_buffer_dirty(sb->sv_bh2);
 	}
 	sb->s_dirt = 0;
+	unlock_kernel();
 }
 
 static void sysv_put_super(struct super_block *sb)

fs/udf/super.c

@@ -359,9 +359,11 @@ udf_parse_options(char *options, struct udf_options *uopt)
 void
 udf_write_super(struct super_block *sb)
 {
+	lock_kernel();
 	if (!(sb->s_flags & MS_RDONLY))
 		udf_open_lvid(sb);
 	sb->s_dirt = 0;
+	unlock_kernel();
 }
 
 static int

fs/ufs/super.c

@@ -822,6 +822,8 @@ void ufs_write_super (struct super_block * sb) {
 	struct ufs_super_block_third * usb3;
 	unsigned flags;
 
+	lock_kernel();
+
 	UFSD(("ENTER\n"))
 	flags = sb->u.ufs_sb.s_flags;
 	uspi = sb->u.ufs_sb.s_uspi;
@@ -838,6 +840,7 @@ void ufs_write_super (struct super_block * sb) {
 	}
 	sb->s_dirt = 0;
 	UFSD(("EXIT\n"))
+	unlock_kernel();
 }
 
 void ufs_put_super (struct super_block * sb)