On Wed, May 06, 2009 at 10:16:31PM +0200, Christoph Hellwig wrote:
> Only four filesystems have both a ->write_super method and use lock_super
> internally: ext4, fat, sysv, ufs. Push down lock_super into these
> filesystems and remove it from the caller. Add a get_fs_excl/put_fs_excl
> pair to sync_super for now to keep the current behaviour in that
> respect. Calling it a second time from write_super is fine as it's
> only checked for beeing non-zero.
>
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Actually the patch lost two hunks due to missing quilt adds. Here's the
complete one:
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Index: vfs-2.6/fs/ext4/super.c
===================================================================
--- vfs-2.6.orig/fs/ext4/super.c 2009-05-06 22:23:00.016784345 +0200
+++ vfs-2.6/fs/ext4/super.c 2009-05-06 22:26:09.741784086 +0200
@@ -66,6 +66,7 @@ static int ext4_remount(struct super_blo
static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
static int ext4_unfreeze(struct super_block *sb);
static void ext4_write_super(struct super_block *sb);
+static void ext4_write_super_locked(struct super_block *sb);
static int ext4_freeze(struct super_block *sb);
@@ -566,7 +567,7 @@ static void ext4_put_super(struct super_
lock_super(sb);
lock_kernel();
if (sb->s_dirt)
- ext4_write_super(sb);
+ ext4_write_super_locked(sb);
ext4_mb_release(sb);
ext4_ext_release(sb);
@@ -3273,17 +3274,22 @@ int ext4_force_commit(struct super_block
* point. (We can probably nuke this function altogether, and remove
* any mention to sb->s_dirt in all of fs/ext4; eventual cleanup...)
*/
-static void ext4_write_super(struct super_block *sb)
+static void ext4_write_super_locked(struct super_block *sb)
{
if (EXT4_SB(sb)->s_journal) {
- if (mutex_trylock(&sb->s_lock) != 0)
- BUG();
sb->s_dirt = 0;
} else {
ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
}
}
+static void ext4_write_super(struct super_block *sb)
+{
+ lock_super(sb);
+ ext4_write_super_locked(sb);
+ unlock_super(sb);
+}
+
static int ext4_sync_fs(struct super_block *sb, int wait)
{
int ret = 0;
Index: vfs-2.6/fs/fat/inode.c
===================================================================
--- vfs-2.6.orig/fs/fat/inode.c 2009-05-06 22:23:00.021784213 +0200
+++ vfs-2.6/fs/fat/inode.c 2009-05-06 22:26:09.741784086 +0200
@@ -441,8 +441,10 @@ static void fat_clear_inode(struct inode
static void fat_write_super(struct super_block *sb)
{
+ lock_super(sb);
sb->s_dirt = 0;
fat_clusters_flush(sb);
+ unlock_super(sb);
}
static void fat_put_super(struct super_block *sb)
Index: vfs-2.6/fs/super.c
===================================================================
--- vfs-2.6.orig/fs/super.c 2009-05-06 22:23:00.025787586 +0200
+++ vfs-2.6/fs/super.c 2009-05-06 22:26:09.742784073 +0200
@@ -421,7 +421,6 @@ restart:
spin_unlock(&sb_lock);
down_read(&sb->s_umount);
- lock_super(sb);
if (sb->s_root) {
/*
* Avoid loops if a filesystem left s_dirt
@@ -433,10 +432,12 @@ restart:
if (sb->s_flags & MS_RDONLY)
sb->s_dirt = 0;
- if (sb->s_dirt)
+ if (sb->s_dirt) {
+ get_fs_excl();
sb->s_op->write_super(sb);
+ put_fs_excl();
+ }
}
- unlock_super(sb);
up_read(&sb->s_umount);
spin_lock(&sb_lock);
Index: vfs-2.6/fs/sysv/inode.c
===================================================================
--- vfs-2.6.orig/fs/sysv/inode.c 2009-05-06 22:23:00.059784161 +0200
+++ vfs-2.6/fs/sysv/inode.c 2009-05-06 22:26:09.743783851 +0200
@@ -37,6 +37,7 @@ static void sysv_write_super(struct supe
struct sysv_sb_info *sbi = SYSV_SB(sb);
unsigned long time = get_seconds(), old_time;
+ lock_super(sb);
lock_kernel();
/*
* If we are going to write out the super block,
@@ -53,6 +54,7 @@ static void sysv_write_super(struct supe
sb->s_dirt = 0;
unlock_kernel();
+ unlock_super(sb);
}
static int sysv_remount(struct super_block *sb, int *flags, char *data)
Index: vfs-2.6/fs/ufs/super.c
===================================================================
--- vfs-2.6.orig/fs/ufs/super.c 2009-05-06 22:23:00.065784017 +0200
+++ vfs-2.6/fs/ufs/super.c 2009-05-06 22:26:09.743783851 +0200
@@ -1131,6 +1131,7 @@ static void ufs_write_super(struct super
struct ufs_super_block_third * usb3;
unsigned flags;
+ lock_super(sb);
lock_kernel();
UFSD("ENTER\n");
flags = UFS_SB(sb)->s_flags;
@@ -1149,6 +1150,7 @@ static void ufs_write_super(struct super
sb->s_dirt = 0;
UFSD("EXIT\n");
unlock_kernel();
+ unlock_super(sb);
}
static void ufs_put_super(struct super_block *sb)
Index: vfs-2.6/fs/sync.c
===================================================================
--- vfs-2.6.orig/fs/sync.c 2009-05-06 22:28:49.598694594 +0200
+++ vfs-2.6/fs/sync.c 2009-05-06 22:29:48.860661341 +0200
@@ -31,10 +31,11 @@ static int __sync_filesystem(struct supe
else
sync_quota_sb(sb, -1);
sync_inodes_sb(sb, wait);
- lock_super(sb);
- if (sb->s_dirt && sb->s_op->write_super)
+ if (sb->s_dirt && sb->s_op->write_super) {
+ get_fs_excl();
sb->s_op->write_super(sb);
- unlock_super(sb);
+ put_fs_excl();
+ }
if (sb->s_op->sync_fs)
sb->s_op->sync_fs(sb, wait);
return __sync_blockdev(sb->s_bdev, wait);
@@ -162,10 +163,11 @@ int file_fsync(struct file *filp, struct
/* sync the superblock to buffers */
sb = inode->i_sb;
- lock_super(sb);
- if (sb->s_dirt && sb->s_op->write_super)
+ if (sb->s_dirt && sb->s_op->write_super) {
+ get_fs_excl();
sb->s_op->write_super(sb);
- unlock_super(sb);
+ put_fs_excl();
+ }
/* .. finally sync the buffers to disk */
err = sync_blockdev(sb->s_bdev);
--
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