->write_super lock_super pushdown
Christoph Hellwig [Mon, 11 May 2009 21:35:03 +0000 (23:35 +0200)]
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>

fs/affs/super.c
fs/exofs/super.c
fs/ext4/super.c
fs/fat/inode.c
fs/hfs/super.c
fs/hfsplus/super.c
fs/jffs2/super.c
fs/super.c
fs/sync.c
fs/sysv/inode.c
fs/ufs/super.c

index d738646..280d361 100644 (file)
@@ -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);
 }
index cd1f8b1..49e16af 100644 (file)
@@ -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);
 }
 
index a9c6834..c17200a 100644 (file)
@@ -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)
index 2b88c93..2292cbf 100644 (file)
@@ -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)
index 9f5eaa0..3aac417 100644 (file)
@@ -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);
 }
 
 /*
index 9b292dc..1aab8aa 100644 (file)
@@ -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)
index a80a50e..f7bfd3a 100644 (file)
@@ -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)
index a64f362..1905f4a 100644 (file)
@@ -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);
index 89c37f7..e9d56f6 100644 (file)
--- 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);
index e0a39f1..a3f45fc 100644 (file)
@@ -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)
index a5ecabf..c97210e 100644 (file)
@@ -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)