->write_super lock_super pushdown

Push down lock_super into ->write_super instances and remove it from the
caller.

Following filesystem don't need ->s_lock in ->write_super and are skipped:

 * bfs, nilfs2 - no other uses of s_lock and have internal locks in
	->write_super
 * ext2 - uses BKL in ext2_write_super and has internal calls without s_lock
 * reiserfs - no other uses of s_lock as has reiserfs_write_lock (BKL) in
 	->write_super
 * xfs - no other uses of s_lock and uses internal lock (buffer lock on
	superblock buffer) to serialize ->write_super.  Also xfs_fs_write_super
	is superflous and will go away in the next merge window

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

11 files changed, 32 insertions, 17 deletions

diff --git a/fs/affs/super.c b/fs/affs/super.c
index d7386462a8e7..280d361af41f 100644
--- a/fs/affs/super.c
+++ b/fs/affs/super.c
@@ -54,6 +54,7 @@ affs_write_super(struct super_block *sb)
         int clean = 2;
         struct affs_sb_info *sbi = AFFS_SB(sb);
 
+        lock_super(sb);
         if (!(sb->s_flags & MS_RDONLY)) {
                 //      if (sbi->s_bitmap[i].bm_bh) {
                 //              if (buffer_dirty(sbi->s_bitmap[i].bm_bh)) {
@@ -66,6 +67,7 @@ affs_write_super(struct super_block *sb)
                 sb->s_dirt = !clean;    /* redo until bitmap synced */
         } else
                 sb->s_dirt = 0;
+        unlock_super(sb);
 
         pr_debug("AFFS: write_super() at %lu, clean=%d\n", get_seconds(), clean);
 }
diff --git a/fs/exofs/super.c b/fs/exofs/super.c
index cd1f8b18a218..49e16af4e619 100644
--- a/fs/exofs/super.c
+++ b/fs/exofs/super.c
@@ -214,6 +214,7 @@ static void exofs_write_super(struct super_block *sb)
                 return;
         }
 
+        lock_super(sb);
         lock_kernel();
         sbi = sb->s_fs_info;
         fscb->s_nextid = cpu_to_le64(sbi->s_nextid);
@@ -246,6 +247,7 @@ out:
         if (or)
                 osd_end_request(or);
         unlock_kernel();
+        unlock_super(sb);
         kfree(fscb);
 }
 
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index a9c683425929..c17200a42301 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -579,7 +579,7 @@ static void ext4_put_super(struct super_block *sb)
         lock_super(sb);
         lock_kernel();
         if (sb->s_dirt)
-                ext4_write_super(sb);
+                ext4_commit_super(sb, 1);
 
         ext4_release_system_zone(sb);
         ext4_mb_release(sb);
@@ -3336,7 +3336,9 @@ int ext4_force_commit(struct super_block *sb)
 
 static void ext4_write_super(struct super_block *sb)
 {
+        lock_super(sb);
         ext4_commit_super(sb, 1);
+        unlock_super(sb);
 }
 
 static int ext4_sync_fs(struct super_block *sb, int wait)
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index 2b88c93af227..2292cbf7d364 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -441,10 +441,12 @@ static void fat_clear_inode(struct inode *inode)
 
 static void fat_write_super(struct super_block *sb)
 {
+        lock_super(sb);
         sb->s_dirt = 0;
 
         if (!(sb->s_flags & MS_RDONLY))
                 fat_clusters_flush(sb);
+        unlock_super(sb);
 }
 
 static void fat_put_super(struct super_block *sb)
diff --git a/fs/hfs/super.c b/fs/hfs/super.c
index 9f5eaa01cc77..3aac41751030 100644
--- a/fs/hfs/super.c
+++ b/fs/hfs/super.c
@@ -49,11 +49,13 @@ MODULE_LICENSE("GPL");
  */
 static void hfs_write_super(struct super_block *sb)
 {
+        lock_super(sb);
         sb->s_dirt = 0;
-        if (sb->s_flags & MS_RDONLY)
-                return;
+
         /* sync everything to the buffers */
-        hfs_mdb_commit(sb);
+        if (!(sb->s_flags & MS_RDONLY))
+                hfs_mdb_commit(sb);
+        unlock_super(sb);
 }
 
 /*
diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index 9b292dcc39c8..1aab8aa7801e 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -157,10 +157,12 @@ static void hfsplus_write_super(struct super_block *sb)
         struct hfsplus_vh *vhdr = HFSPLUS_SB(sb).s_vhdr;
 
         dprint(DBG_SUPER, "hfsplus_write_super\n");
+
+        lock_super(sb);
         sb->s_dirt = 0;
         if (sb->s_flags & MS_RDONLY)
                 /* warn? */
-                return;
+                goto out;
 
         vhdr->free_blocks = cpu_to_be32(HFSPLUS_SB(sb).free_blocks);
         vhdr->next_alloc = cpu_to_be32(HFSPLUS_SB(sb).next_alloc);
@@ -192,6 +194,8 @@ static void hfsplus_write_super(struct super_block *sb)
                 }
                 HFSPLUS_SB(sb).flags &= ~HFSPLUS_SB_WRITEBACKUP;
         }
+ out:
+        unlock_super(sb);
 }
 
 static void hfsplus_put_super(struct super_block *sb)
diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
index a80a50e445e2..f7bfd3ac8bfa 100644
--- a/fs/jffs2/super.c
+++ b/fs/jffs2/super.c
@@ -56,15 +56,18 @@ static void jffs2_i_init_once(void *foo)
 static void jffs2_write_super(struct super_block *sb)
 {
         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
+
+        lock_super(sb);
         sb->s_dirt = 0;
 
-        if (sb->s_flags & MS_RDONLY)
-                return;
+        if (!(sb->s_flags & MS_RDONLY)) {
+                D1(printk(KERN_DEBUG "jffs2_write_super()\n"));
+                jffs2_garbage_collect_trigger(c);
+                jffs2_erase_pending_blocks(c, 0);
+                jffs2_flush_wbuf_gc(c, 0);
+        }
 
-        D1(printk(KERN_DEBUG "jffs2_write_super()\n"));
-        jffs2_garbage_collect_trigger(c);
-        jffs2_erase_pending_blocks(c, 0);
-        jffs2_flush_wbuf_gc(c, 0);
+        unlock_super(sb);
 }
 
 static int jffs2_sync_fs(struct super_block *sb, int wait)
diff --git a/fs/super.c b/fs/super.c
index a64f36208797..1905f4af01cc 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -420,10 +420,8 @@ restart:
                         spin_unlock(&sb_lock);
 
                         down_read(&sb->s_umount);
-                        lock_super(sb);
                         if (sb->s_root && sb->s_dirt)
                                 sb->s_op->write_super(sb);
-                        unlock_super(sb);
                         up_read(&sb->s_umount);
 
                         spin_lock(&sb_lock);
diff --git a/fs/sync.c b/fs/sync.c
index 89c37f732afa..e9d56f6c0b74 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -33,10 +33,8 @@ static int __sync_filesystem(struct super_block *sb, int wait)
         else
                 sync_quota_sb(sb, -1);
         sync_inodes_sb(sb, wait);
-        lock_super(sb);
         if (sb->s_dirt && sb->s_op->write_super)
                 sb->s_op->write_super(sb);
-        unlock_super(sb);
         if (sb->s_op->sync_fs)
                 sb->s_op->sync_fs(sb, wait);
         return __sync_blockdev(sb->s_bdev, wait);
@@ -164,10 +162,8 @@ int file_fsync(struct file *filp, struct dentry *dentry, int datasync)
 
         /* sync the superblock to buffers */
         sb = inode->i_sb;
-        lock_super(sb);
         if (sb->s_dirt && sb->s_op->write_super)
                 sb->s_op->write_super(sb);
-        unlock_super(sb);
 
         /* .. finally sync the buffers to disk */
         err = sync_blockdev(sb->s_bdev);
diff --git a/fs/sysv/inode.c b/fs/sysv/inode.c
index e0a39f1fb88e..a3f45fc626a1 100644
--- a/fs/sysv/inode.c
+++ b/fs/sysv/inode.c
@@ -37,6 +37,7 @@ static void sysv_write_super(struct super_block *sb)
         struct sysv_sb_info *sbi = SYSV_SB(sb);
         unsigned long time = get_seconds(), old_time;
 
+        lock_super(sb);
         lock_kernel();
         if (sb->s_flags & MS_RDONLY)
                 goto clean;
@@ -56,6 +57,7 @@ static void sysv_write_super(struct super_block *sb)
 clean:
         sb->s_dirt = 0;
         unlock_kernel();
+        unlock_super(sb);
 }
 
 static int sysv_remount(struct super_block *sb, int *flags, char *data)
diff --git a/fs/ufs/super.c b/fs/ufs/super.c
index a5ecabfdc976..c97210ee0670 100644
--- a/fs/ufs/super.c
+++ b/fs/ufs/super.c
@@ -1131,6 +1131,7 @@ static void ufs_write_super(struct super_block *sb)
         struct ufs_super_block_third * usb3;
         unsigned flags;
 
+        lock_super(sb);
         lock_kernel();
         UFSD("ENTER\n");
         flags = UFS_SB(sb)->s_flags;
@@ -1150,6 +1151,7 @@ static void ufs_write_super(struct super_block *sb)
         sb->s_dirt = 0;
         UFSD("EXIT\n");
         unlock_kernel();
+        unlock_super(sb);
 }
 
 static void ufs_put_super(struct super_block *sb)