[PATCH v2] fs/buffer: Convert return type int to vm_fault_t

From: Souptick Joarder
Date: Mon Jul 30 2018 - 10:59:04 EST


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.linux@xxxxxxxxx>
---
v2: Address Jens's comment. Remove ret variable
from block_page_mkwrite().

fs/buffer.c | 16 ++++++++--------
fs/nilfs2/file.c | 13 ++++++++-----
include/linux/buffer_head.h | 2 +-
3 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/fs/buffer.c b/fs/buffer.c
index cabc045..aeed99f 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2444,21 +2444,21 @@ 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;
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;
}

@@ -2468,18 +2468,18 @@ 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);
- return ret;
+ return block_page_mkwrite_return(err);
}
EXPORT_SYMBOL(block_page_mkwrite);

diff --git a/fs/nilfs2/file.c b/fs/nilfs2/file.c
index c5fa3de..da2759e 100644
--- a/fs/nilfs2/file.c
+++ b/fs/nilfs2/file.c
@@ -57,7 +57,8 @@ static int 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 int 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 int 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 int 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 ed7a81b..7184c6e 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -240,7 +240,7 @@ 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 vm_fault_t block_page_mkwrite_return(int err)
--
1.9.1