f2fs: reorganize f2fs_vm_page_mkwrite

Few things can be changed in the default mkwrite function
1) Make file_update_time at the start before acquiring any lock
2) the condition page_offset(page) >= i_size_read(inode) should be
 changed to page_offset(page) > i_size_read
3) Move wait_on_page_writeback.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index b8e34db..9937ba1 100644 (file)
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -63,9 +63,10 @@ static int f2fs_vm_page_mkwrite(struct vm_area_struct *vma,
        f2fs_put_dnode(&dn);
        mutex_unlock_op(sbi, ilock);
 
+       file_update_time(vma->vm_file);
        lock_page(page);
        if (page->mapping != inode->i_mapping ||
-                       page_offset(page) >= i_size_read(inode) ||
+                       page_offset(page) > i_size_read(inode) ||
                        !PageUptodate(page)) {
                unlock_page(page);
                err = -EFAULT;
@@ -76,10 +77,7 @@ static int f2fs_vm_page_mkwrite(struct vm_area_struct *vma,
         * check to see if the page is mapped already (no holes)
         */
        if (PageMappedToDisk(page))
-               goto out;
-
-       /* fill the page */
-       wait_on_page_writeback(page);
+               goto mapped;
 
        /* page is wholly or partially inside EOF */
        if (((page->index + 1) << PAGE_CACHE_SHIFT) > i_size_read(inode)) {
@@ -90,7 +88,9 @@ static int f2fs_vm_page_mkwrite(struct vm_area_struct *vma,
        set_page_dirty(page);
        SetPageUptodate(page);
 
-       file_update_time(vma->vm_file);
+mapped:
+       /* fill the page */
+       wait_on_page_writeback(page);
 out:
        sb_end_pagefault(inode->i_sb);
        return block_page_mkwrite_return(err);