The patch titled
Subject: hfs: push lock_super down
has been added to the -mm tree. Its filename is
hfs-push-lock_super-down.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Artem Bityutskiy <artem.bityutskiy@xxxxxxxxxxxxxxx>
Subject: hfs: push lock_super down
This patchset makes the HFS file-system stop using the VFS
'->write_supers()' call-back and the '->s_dirt' superblock field because I
plan to remove them once all users are gone.
Like the other similar patchsets, we switch to a delayed job for writing
out the superblock instead of using the 's_dirt' flag. Additionally, this
patchset includes several cleanups.
Reminder:
The goal is to get rid of the 'sync_supers()' kernel thread. This kernel
thread wakes up every 5 seconds (by default) and calls '->write_super()'
for all mounted file-systems. And the bad thing is that this is done even
if all the superblocks are clean. Moreover, many file-systems do not even
need this end they do not register the '->write_super()' method at all
(e.g., btrfs).
So 'sync_supers()' most often just generates useless wake-ups and wastes
power. I am trying to make all file-systems independent of
'->write_super()' and plan to remove 'sync_supers()' and '->write_super()'
completely once there are no more users.
Tested using the fsstress test from the LTP project.
This patch:
HFS uses 'lock_super()'/'unlock_super()' around 'hfs_mdb_commit()' in
order to serialize MDB (Master Directory Block) changes. Push it down to
'hfs_mdb_commit()' in order to simplify the code a bit.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@xxxxxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/hfs/inode.c | 2 --
fs/hfs/mdb.c | 2 ++
fs/hfs/super.c | 4 ----
3 files changed, 2 insertions(+), 6 deletions(-)
diff -puN fs/hfs/inode.c~hfs-push-lock_super-down fs/hfs/inode.c
--- a/fs/hfs/inode.c~hfs-push-lock_super-down
+++ a/fs/hfs/inode.c
@@ -645,11 +645,9 @@ static int hfs_file_fsync(struct file *f
/* sync the superblock to buffers */
sb = inode->i_sb;
if (sb->s_dirt) {
- lock_super(sb);
sb->s_dirt = 0;
if (!(sb->s_flags & MS_RDONLY))
hfs_mdb_commit(sb);
- unlock_super(sb);
}
/* .. finally sync the buffers to disk */
err = sync_blockdev(sb->s_bdev);
diff -puN fs/hfs/mdb.c~hfs-push-lock_super-down fs/hfs/mdb.c
--- a/fs/hfs/mdb.c~hfs-push-lock_super-down
+++ a/fs/hfs/mdb.c
@@ -260,6 +260,7 @@ void hfs_mdb_commit(struct super_block *
{
struct hfs_mdb *mdb = HFS_SB(sb)->mdb;
+ lock_super(sb);
if (test_and_clear_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags)) {
/* These parameters may have been modified, so write them back */
mdb->drLsMod = hfs_mtime();
@@ -317,6 +318,7 @@ void hfs_mdb_commit(struct super_block *
size -= len;
}
}
+ unlock_super(sb);
}
void hfs_mdb_close(struct super_block *sb)
diff -puN fs/hfs/super.c~hfs-push-lock_super-down fs/hfs/super.c
--- a/fs/hfs/super.c~hfs-push-lock_super-down
+++ a/fs/hfs/super.c
@@ -50,21 +50,17 @@ MODULE_LICENSE("GPL");
*/
static void hfs_write_super(struct super_block *sb)
{
- lock_super(sb);
sb->s_dirt = 0;
/* sync everything to the buffers */
if (!(sb->s_flags & MS_RDONLY))
hfs_mdb_commit(sb);
- unlock_super(sb);
}
static int hfs_sync_fs(struct super_block *sb, int wait)
{
- lock_super(sb);
hfs_mdb_commit(sb);
sb->s_dirt = 0;
- unlock_super(sb);
return 0;
}
_
Subject: Subject: hfs: push lock_super down
Patches currently in -mm which might be from artem.bityutskiy@xxxxxxxxxxxxxxx are
linux-next.patch
hfs-push-lock_super-down.patch
hfs-get-rid-of-lock_super.patch
hfs-remove-extra-mdb-write-on-unmount.patch
hfs-simplify-a-bit-checking-for-r-o.patch
hfs-introduce-vfs-superblock-object-back-reference.patch
hfs-get-rid-of-hfs_sync_super.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
