Unionfs: fold do_readpage into unionfs_readpage

Simplify the code and reduce stack pressure a bit.

Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>

diff --git a/fs/unionfs/mmap.c b/fs/unionfs/mmap.c
index 34fd8aa0f925be0ff13be6be02e2e59f700ce3b5..ef8822ff7f85220de5668d40eeea50d6657eb577 100644 (file)
--- a/fs/unionfs/mmap.c
+++ b/fs/unionfs/mmap.c
@@ -136,22 +136,22 @@ out:
        return err;
 }
 
-/*
- * readpage is called from generic_page_read and the fault handler.
- * If your file system uses generic_page_read for the read op, it
- * must implement readpage.
- *
- * Readpage expects a locked page, and must unlock it.
- */
-static int unionfs_do_readpage(struct file *file, struct page *page)
+/* Readpage expects a locked page, and must unlock it */
+static int unionfs_readpage(struct file *file, struct page *page)
 {
-       int err = -EIO;
+       int err;
        struct file *lower_file;
        struct inode *inode;
        mm_segment_t old_fs;
        char *page_data = NULL;
        loff_t offset;
 
+       unionfs_read_lock(file->f_path.dentry->d_sb);
+       err = unionfs_file_revalidate(file, false);
+       if (unlikely(err))
+               goto out;
+       unionfs_check_file(file);
+
        if (!UNIONFS_F(file)) {
                err = -ENOENT;
                goto out;
@@ -191,33 +191,17 @@ static int unionfs_do_readpage(struct file *file, struct page *page)
 
        flush_dcache_page(page);
 
-out:
-       if (err == 0)
-               SetPageUptodate(page);
-       else
-               ClearPageUptodate(page);
-
-       return err;
-}
-
-static int unionfs_readpage(struct file *file, struct page *page)
-{
-       int err;
-
-       unionfs_read_lock(file->f_path.dentry->d_sb);
-       err = unionfs_file_revalidate(file, false);
-       if (unlikely(err))
-               goto out;
-       unionfs_check_file(file);
-
-       err = unionfs_do_readpage(file, page);
-
        /*
         * we have to unlock our page, b/c we _might_ have gotten a locked
         * page.  but we no longer have to wakeup on our page here, b/c
         * UnlockPage does it
         */
 out:
+       if (err == 0)
+               SetPageUptodate(page);
+       else
+               ClearPageUptodate(page);
+
        unlock_page(page);
        unionfs_check_file(file);
        unionfs_read_unlock(file->f_path.dentry->d_sb);