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>
Index: vfs-2.6/fs/ext4/super.c
===================================================================
--- vfs-2.6.orig/fs/ext4/super.c 2009-05-06 21:35:40.923658961 +0200
+++ vfs-2.6/fs/ext4/super.c 2009-05-06 21:37:07.337661434 +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);
@@ -3273,7 +3274,7 @@ 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)
@@ -3284,6 +3285,13 @@ static void ext4_write_super(struct supe
}
}
+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 21:37:16.737659384 +0200
+++ vfs-2.6/fs/fat/inode.c 2009-05-06 21:37:53.358661652 +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 21:41:00.805784126 +0200
+++ vfs-2.6/fs/super.c 2009-05-06 21:41:57.191661325 +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 21:39:21.263682879 +0200
+++ vfs-2.6/fs/sysv/inode.c 2009-05-06 21:39:58.219661498 +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 21:40:01.440659714 +0200
+++ vfs-2.6/fs/ufs/super.c 2009-05-06 21:40:33.502786591 +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)
--
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