1 files changed, 11 insertions, 157 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index 9f697419ed8e..a2fd743d97cb 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -166,151 +166,6 @@ void end_buffer_write_sync(struct buffer_head *bh, int uptodate)
 }
 
 /*
- * Write out and wait upon all the dirty data associated with a block
- * device via its mapping.  Does not take the superblock lock.
- */
-int sync_blockdev(struct block_device *bdev)
-{
-        int ret = 0;
-
-        if (bdev)
-                ret = filemap_write_and_wait(bdev->bd_inode->i_mapping);
-        return ret;
-}
-EXPORT_SYMBOL(sync_blockdev);
-
-/*
- * Write out and wait upon all dirty data associated with this
- * device.   Filesystem data as well as the underlying block
- * device.  Takes the superblock lock.
- */
-int fsync_bdev(struct block_device *bdev)
-{
-        struct super_block *sb = get_super(bdev);
-        if (sb) {
-                int res = fsync_super(sb);
-                drop_super(sb);
-                return res;
-        }
-        return sync_blockdev(bdev);
-}
-
-/**
- * freeze_bdev  --  lock a filesystem and force it into a consistent state
- * @bdev:       blockdevice to lock
- *
- * This takes the block device bd_mount_sem to make sure no new mounts
- * happen on bdev until thaw_bdev() is called.
- * If a superblock is found on this device, we take the s_umount semaphore
- * on it to make sure nobody unmounts until the snapshot creation is done.
- * The reference counter (bd_fsfreeze_count) guarantees that only the last
- * unfreeze process can unfreeze the frozen filesystem actually when multiple
- * freeze requests arrive simultaneously. It counts up in freeze_bdev() and
- * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze
- * actually.
- */
-struct super_block *freeze_bdev(struct block_device *bdev)
-{
-        struct super_block *sb;
-        int error = 0;
-
-        mutex_lock(&bdev->bd_fsfreeze_mutex);
-        if (bdev->bd_fsfreeze_count > 0) {
-                bdev->bd_fsfreeze_count++;
-                sb = get_super(bdev);
-                mutex_unlock(&bdev->bd_fsfreeze_mutex);
-                return sb;
-        }
-        bdev->bd_fsfreeze_count++;
-
-        down(&bdev->bd_mount_sem);
-        sb = get_super(bdev);
-        if (sb && !(sb->s_flags & MS_RDONLY)) {
-                sb->s_frozen = SB_FREEZE_WRITE;
-                smp_wmb();
-
-                __fsync_super(sb);
-
-                sb->s_frozen = SB_FREEZE_TRANS;
-                smp_wmb();
-
-                sync_blockdev(sb->s_bdev);
-
-                if (sb->s_op->freeze_fs) {
-                        error = sb->s_op->freeze_fs(sb);
-                        if (error) {
-                                printk(KERN_ERR
-                                        "VFS:Filesystem freeze failed\n");
-                                sb->s_frozen = SB_UNFROZEN;
-                                drop_super(sb);
-                                up(&bdev->bd_mount_sem);
-                                bdev->bd_fsfreeze_count--;
-                                mutex_unlock(&bdev->bd_fsfreeze_mutex);
-                                return ERR_PTR(error);
-                        }
-                }
-        }
-
-        sync_blockdev(bdev);
-        mutex_unlock(&bdev->bd_fsfreeze_mutex);
-
-        return sb;      /* thaw_bdev releases s->s_umount and bd_mount_sem */
-}
-EXPORT_SYMBOL(freeze_bdev);
-
-/**
- * thaw_bdev  -- unlock filesystem
- * @bdev:       blockdevice to unlock
- * @sb:         associated superblock
- *
- * Unlocks the filesystem and marks it writeable again after freeze_bdev().
- */
-int thaw_bdev(struct block_device *bdev, struct super_block *sb)
-{
-        int error = 0;
-
-        mutex_lock(&bdev->bd_fsfreeze_mutex);
-        if (!bdev->bd_fsfreeze_count) {
-                mutex_unlock(&bdev->bd_fsfreeze_mutex);
-                return -EINVAL;
-        }
-
-        bdev->bd_fsfreeze_count--;
-        if (bdev->bd_fsfreeze_count > 0) {
-                if (sb)
-                        drop_super(sb);
-                mutex_unlock(&bdev->bd_fsfreeze_mutex);
-                return 0;
-        }
-
-        if (sb) {
-                BUG_ON(sb->s_bdev != bdev);
-                if (!(sb->s_flags & MS_RDONLY)) {
-                        if (sb->s_op->unfreeze_fs) {
-                                error = sb->s_op->unfreeze_fs(sb);
-                                if (error) {
-                                        printk(KERN_ERR
-                                                "VFS:Filesystem thaw failed\n");
-                                        sb->s_frozen = SB_FREEZE_TRANS;
-                                        bdev->bd_fsfreeze_count++;
-                                        mutex_unlock(&bdev->bd_fsfreeze_mutex);
-                                        return error;
-                                }
-                        }
-                        sb->s_frozen = SB_UNFROZEN;
-                        smp_wmb();
-                        wake_up(&sb->s_wait_unfrozen);
-                }
-                drop_super(sb);
-        }
-
-        up(&bdev->bd_mount_sem);
-        mutex_unlock(&bdev->bd_fsfreeze_mutex);
-        return 0;
-}
-EXPORT_SYMBOL(thaw_bdev);
-
-/*
  * Various filesystems appear to want __find_get_block to be non-blocking.
  * But it's the page lock which protects the buffers.  To get around this,
  * we get exclusion from try_to_free_buffers with the blockdev mapping's
@@ -760,15 +615,9 @@ EXPORT_SYMBOL(mark_buffer_dirty_inode);
  * If warn is true, then emit a warning if the page is not uptodate and has
  * not been truncated.
  */
-static int __set_page_dirty(struct page *page,
+static void __set_page_dirty(struct page *page,
                 struct address_space *mapping, int warn)
 {
-        if (unlikely(!mapping))
-                return !TestSetPageDirty(page);
-
-        if (TestSetPageDirty(page))
-                return 0;
-
         spin_lock_irq(&mapping->tree_lock);
         if (page->mapping) {    /* Race with truncate? */
                 WARN_ON_ONCE(warn && !PageUptodate(page));
@@ -785,8 +634,6 @@ static int __set_page_dirty(struct page *page,
         }
         spin_unlock_irq(&mapping->tree_lock);
         __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
-
-        return 1;
 }
 
 /*
@@ -816,6 +663,7 @@ static int __set_page_dirty(struct page *page,
  */
 int __set_page_dirty_buffers(struct page *page)
 {
+        int newly_dirty;
         struct address_space *mapping = page_mapping(page);
 
         if (unlikely(!mapping))
@@ -831,9 +679,12 @@ int __set_page_dirty_buffers(struct page *page)
                         bh = bh->b_this_page;
                 } while (bh != head);
         }
+        newly_dirty = !TestSetPageDirty(page);
         spin_unlock(&mapping->private_lock);
 
-        return __set_page_dirty(page, mapping, 1);
+        if (newly_dirty)
+                __set_page_dirty(page, mapping, 1);
+        return newly_dirty;
 }
 EXPORT_SYMBOL(__set_page_dirty_buffers);
 
@@ -1262,8 +1113,11 @@ void mark_buffer_dirty(struct buffer_head *bh)
                         return;
         }
 
-        if (!test_set_buffer_dirty(bh))
-                __set_page_dirty(bh->b_page, page_mapping(bh->b_page), 0);
+        if (!test_set_buffer_dirty(bh)) {
+                struct page *page = bh->b_page;
+                if (!TestSetPageDirty(page))
+                        __set_page_dirty(page, page_mapping(page), 0);
+        }
 }
 
 /*