[linux-lvm] Re: VFS locking patch fails on 2.4.4

[Chris Mason <mason@suse.com>]

The only rejects were in fs.h, but here is a new patch against 2.4.4

diff -Nru a/drivers/md/lvm.c b/drivers/md/lvm.c
--- a/drivers/md/lvm.c	Sun Apr 29 20:48:50 2001
+++ b/drivers/md/lvm.c	Sun Apr 29 20:48:50 2001
@@ -207,7 +207,7 @@
 #define LOCAL_END_REQUEST
 
 /* lvm_do_lv_create calls fsync_dev_lockfs()/unlockfs() */
-/* #define	LVM_VFS_ENHANCEMENT */
+#define	LVM_VFS_ENHANCEMENT
 
 #include <linux/config.h>
 #include <linux/module.h>
diff -Nru a/fs/buffer.c b/fs/buffer.c
--- a/fs/buffer.c	Sun Apr 29 20:48:50 2001
+++ b/fs/buffer.c	Sun Apr 29 20:48:50 2001
@@ -331,6 +331,28 @@
 	return sync_buffers(dev, 1);
 }
 
+int fsync_dev_lockfs(kdev_t dev)
+{
+	sync_buffers(dev, 0);
+
+	lock_kernel();
+	sync_supers(dev);
+	/* note, the FS might need to start transactions to 
+	** sync the inodes, or the quota, no locking until
+	** after these are done
+	*/
+	sync_inodes(dev);
+	DQUOT_SYNC(dev);
+	/* if inodes or quotas could be dirtied during the
+	** sync_supers_lockfs call, the FS is responsible for getting
+	** them on disk, without deadlocking against the lock
+	*/
+	sync_supers_lockfs(dev) ;
+	unlock_kernel();
+
+	return sync_buffers(dev, 1) ;
+}
+
 asmlinkage long sys_sync(void)
 {
 	fsync_dev(0);
diff -Nru a/fs/super.c b/fs/super.c
--- a/fs/super.c	Sun Apr 29 20:48:49 2001
+++ b/fs/super.c	Sun Apr 29 20:48:49 2001
@@ -630,6 +630,46 @@
 	}
 }
 
+/*
+ * Note: don't check the dirty flag before waiting, we want the lock
+ * to happen every time this is called.
+ */
+void sync_supers_lockfs(kdev_t dev)
+{
+	struct super_block * sb;
+
+	for (sb = sb_entry(super_blocks.next);
+	     sb != sb_entry(&super_blocks); 
+	     sb = sb_entry(sb->s_list.next)) {
+		if (!sb->s_dev)
+			continue;
+		if (dev && sb->s_dev != dev)
+			continue;
+		lock_super(sb);
+		if (sb->s_dev && (!dev || dev == sb->s_dev))
+			if (sb->s_op && sb->s_op->write_super_lockfs)
+				sb->s_op->write_super_lockfs(sb);
+		unlock_super(sb);
+	}
+}
+
+void unlockfs(kdev_t dev)
+{
+	struct super_block * sb;
+
+	for (sb = sb_entry(super_blocks.next);
+	     sb != sb_entry(&super_blocks); 
+	     sb = sb_entry(sb->s_list.next)) {
+		if (!sb->s_dev)
+			continue;
+		if (dev && sb->s_dev != dev)
+			continue;
+		if (sb->s_dev && (!dev || dev == sb->s_dev))
+			if (sb->s_op && sb->s_op->unlockfs)
+				sb->s_op->unlockfs(sb);
+	}
+}
+
 /**
  *	get_super	-	get the superblock of a device
  *	@dev: device to get the superblock for
diff -Nru a/include/linux/fs.h b/include/linux/fs.h
--- a/include/linux/fs.h	Sun Apr 29 20:48:50 2001
+++ b/include/linux/fs.h	Sun Apr 29 20:48:50 2001
@@ -1107,6 +1107,7 @@
 extern void write_inode_now(struct inode *, int);
 extern void sync_dev(kdev_t);
 extern int fsync_dev(kdev_t);
+extern int fsync_dev_lockfs(kdev_t);
 extern int fsync_super(struct super_block *);
 extern void sync_inodes_sb(struct super_block *);
 extern int osync_inode_buffers(struct inode *);
@@ -1117,6 +1118,8 @@
 extern void filemap_fdatasync(struct address_space *);
 extern void filemap_fdatawait(struct address_space *);
 extern void sync_supers(kdev_t);
+extern void sync_supers_lockfs(kdev_t);
+extern void unlockfs(kdev_t);
 extern int bmap(struct inode *, int);
 extern int notify_change(struct dentry *, struct iattr *);
 extern int permission(struct inode *, int);
diff -Nru a/kernel/ksyms.c b/kernel/ksyms.c
--- a/kernel/ksyms.c	Sun Apr 29 20:48:50 2001
+++ b/kernel/ksyms.c	Sun Apr 29 20:48:50 2001
@@ -179,6 +179,8 @@
 EXPORT_SYMBOL(invalidate_inode_pages);
 EXPORT_SYMBOL(truncate_inode_pages);
 EXPORT_SYMBOL(fsync_dev);
+EXPORT_SYMBOL(fsync_dev_lockfs);
+EXPORT_SYMBOL(unlockfs);
 EXPORT_SYMBOL(permission);
 EXPORT_SYMBOL(vfs_permission);
 EXPORT_SYMBOL(inode_setattr);