fs/ufs: get rid of write_super
This patch makes UFS stop using the VFS '->write_super()' method along with
the 's_dirt' superblock flag, because they are on their way out.
The way we implement this is that we schedule a delay job instead relying on
's_dirt' and '->write_super()'.
The whole "superblock write-out" VFS infrastructure is served by the
'sync_supers()' kernel thread, which wakes up every 5 (by default) seconds and
writes out all dirty superblocks using the '->write_super()' call-back. But the
problem with this thread is that it wastes power by waking up the system every
5 seconds, even if there are no diry superblocks, or there are no client
file-systems which would need this (e.g., btrfs does not use
'->write_super()'). So we want to kill it completely and thus, we need to make
file-systems to stop using the '->write_super()' VFS service, and then remove
it together with the kernel thread.
Tested using fsstress from the LTP project.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/ufs/ufs.h b/fs/ufs/ufs.h
index 528750b..343e6fc 100644
--- a/fs/ufs/ufs.h
+++ b/fs/ufs/ufs.h
@@ -20,6 +20,10 @@
unsigned s_mount_opt;
struct mutex mutex;
struct task_struct *mutex_owner;
+ struct super_block *sb;
+ int work_queued; /* non-zero if the delayed work is queued */
+ struct delayed_work sync_work; /* FS sync delayed work */
+ spinlock_t work_lock; /* protects sync_work and work_queued */
};
struct ufs_inode_info {
@@ -123,6 +127,7 @@
void ufs_error(struct super_block *, const char *, const char *, ...);
extern __printf(3, 4)
void ufs_panic(struct super_block *, const char *, const char *, ...);
+void ufs_mark_sb_dirty(struct super_block *sb);
/* symlink.c */
extern const struct inode_operations ufs_fast_symlink_inode_operations;