[PATCH] fs/buffer: Convert return type int to vm_fault_t

[Souptick Joarder]

Return type of block_page_mkwrite() is converted to
vm_fault_t type. The caller of block_page_mkwrite
inside fs/nilfs2 nilfs_page_mkwrite converted accordingly.

Signed-off-by: Souptick Joarder <jrdr.li...@gmail.com>
---
 fs/buffer.c                 | 16 +++++++++-------
 fs/nilfs2/file.c            | 13 ++++++++-----
 include/linux/buffer_head.h |  2 +-
 3 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/fs/buffer.c b/fs/buffer.c
index be31e28..463aa27 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2456,21 +2456,22 @@ int block_commit_write(struct page *page, unsigned 
from, unsigned to)
  * Direct callers of this function should protect against filesystem freezing
  * using sb_start_pagefault() - sb_end_pagefault() functions.
  */
-int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
+vm_fault_t block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
                         get_block_t get_block)
 {
        struct page *page = vmf->page;
        struct inode *inode = file_inode(vma->vm_file);
        unsigned long end;
+       vm_fault_t ret;
        loff_t size;
-       int ret;
+       int err;
 
        lock_page(page);
        size = i_size_read(inode);
        if ((page->mapping != inode->i_mapping) ||
            (page_offset(page) > size)) {
                /* We overload EFAULT to mean page got truncated */
-               ret = -EFAULT;
+               err = -EFAULT;
                goto out_unlock;
        }
 
@@ -2480,17 +2481,18 @@ int block_page_mkwrite(struct vm_area_struct *vma, 
struct vm_fault *vmf,
        else
                end = PAGE_SIZE;
 
-       ret = __block_write_begin(page, 0, end, get_block);
-       if (!ret)
-               ret = block_commit_write(page, 0, end);
+       err = __block_write_begin(page, 0, end, get_block);
+       if (!err)
+               err = block_commit_write(page, 0, end);
 
-       if (unlikely(ret < 0))
+       if (unlikely(err < 0))
                goto out_unlock;
        set_page_dirty(page);
        wait_for_stable_page(page);
        return 0;
 out_unlock:
        unlock_page(page);
+       ret = block_page_mkwrite_return(err);
        return ret;
 }
 EXPORT_SYMBOL(block_page_mkwrite);
diff --git a/fs/nilfs2/file.c b/fs/nilfs2/file.c
index 7da0fac..3733883 100644
--- a/fs/nilfs2/file.c
+++ b/fs/nilfs2/file.c
@@ -57,7 +57,8 @@ static vm_fault_t nilfs_page_mkwrite(struct vm_fault *vmf)
        struct page *page = vmf->page;
        struct inode *inode = file_inode(vma->vm_file);
        struct nilfs_transaction_info ti;
-       int ret = 0;
+       vm_fault_t ret = VM_FAULT_LOCKED;
+       int err = 0;
 
        if (unlikely(nilfs_near_disk_full(inode->i_sb->s_fs_info)))
                return VM_FAULT_SIGBUS; /* -ENOSPC */
@@ -67,7 +68,7 @@ static vm_fault_t nilfs_page_mkwrite(struct vm_fault *vmf)
        if (page->mapping != inode->i_mapping ||
            page_offset(page) >= i_size_read(inode) || !PageUptodate(page)) {
                unlock_page(page);
-               ret = -EFAULT;  /* make the VM retry the fault */
+               ret = VM_FAULT_NOPAGE;  /* make the VM retry the fault */
                goto out;
        }
 
@@ -99,10 +100,12 @@ static vm_fault_t nilfs_page_mkwrite(struct vm_fault *vmf)
        /*
         * fill hole blocks
         */
-       ret = nilfs_transaction_begin(inode->i_sb, &ti, 1);
+       err = nilfs_transaction_begin(inode->i_sb, &ti, 1);
        /* never returns -ENOMEM, but may return -ENOSPC */
-       if (unlikely(ret))
+       if (unlikely(err)) {
+               ret = block_page_mkwrite_return(err);
                goto out;
+       }
 
        file_update_time(vma->vm_file);
        ret = block_page_mkwrite(vma, vmf, nilfs_get_block);
@@ -117,7 +120,7 @@ static vm_fault_t nilfs_page_mkwrite(struct vm_fault *vmf)
        wait_for_stable_page(page);
  out:
        sb_end_pagefault(inode->i_sb);
-       return block_page_mkwrite_return(ret);
+       return ret;
 }
 
 static const struct vm_operations_struct nilfs_file_vm_ops = {
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index 96225a7..1aeeb54 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -239,7 +239,7 @@ int cont_write_begin(struct file *, struct address_space *, 
loff_t,
                        get_block_t *, loff_t *);
 int generic_cont_expand_simple(struct inode *inode, loff_t size);
 int block_commit_write(struct page *page, unsigned from, unsigned to);
-int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
+vm_fault_t block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
                                get_block_t get_block);
 /* Convert errno to return value from ->page_mkwrite() call */
 static inline int block_page_mkwrite_return(int err)
-- 
1.9.1