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>

1 files changed, 4 insertions, 4 deletions

diff --git a/fs/ufs/balloc.c b/fs/ufs/balloc.c
index 42694e11c23d..1b3e410bf334 100644
--- a/fs/ufs/balloc.c
+++ b/fs/ufs/balloc.c
@@ -116,7 +116,7 @@ void ufs_free_fragments(struct inode *inode, u64 fragment, unsigned count)
         ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
         if (sb->s_flags & MS_SYNCHRONOUS)
                 ubh_sync_block(UCPI_UBH(ucpi));
-        sb->s_dirt = 1;
+        ufs_mark_sb_dirty(sb);
         
         unlock_super (sb);
         UFSD("EXIT\n");
@@ -214,7 +214,7 @@ do_more:
                 goto do_more;
         }
 
-        sb->s_dirt = 1;
+        ufs_mark_sb_dirty(sb);
         unlock_super (sb);
         UFSD("EXIT\n");
         return;
@@ -557,7 +557,7 @@ static u64 ufs_add_fragments(struct inode *inode, u64 fragment,
         ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
         if (sb->s_flags & MS_SYNCHRONOUS)
                 ubh_sync_block(UCPI_UBH(ucpi));
-        sb->s_dirt = 1;
+        ufs_mark_sb_dirty(sb);
 
         UFSD("EXIT, fragment %llu\n", (unsigned long long)fragment);
         
@@ -677,7 +677,7 @@ succed:
         ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
         if (sb->s_flags & MS_SYNCHRONOUS)
                 ubh_sync_block(UCPI_UBH(ucpi));
-        sb->s_dirt = 1;
+        ufs_mark_sb_dirty(sb);
 
         result += cgno * uspi->s_fpg;
         UFSD("EXIT3, result %llu\n", (unsigned long long)result);