[PATCH] fs: btrfs: Change return type to vm_fault_t

From: Souptick Joarder
Date: Tue Jun 05 2018 - 11:44:25 EST


Use new return type vm_fault_t for fault handler. For
now, this is just documenting that the function returns
a VM_FAULT value rather than an errno. Once all instances
are converted, vm_fault_t will become a distinct type.

Ref-> commit 1c8f422059ae ("mm: change return type to vm_fault_t")

vmf_error() is the newly introduce inline function
in 4.17-rc6.

Signed-off-by: Souptick Joarder <jrdr.linux@xxxxxxxxx>
---
fs/btrfs/ctree.h | 2 +-
fs/btrfs/inode.c | 28 +++++++++++++---------------
2 files changed, 14 insertions(+), 16 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 0d422c9..1f52d9fd 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3218,7 +3218,7 @@ int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
size_t size, struct bio *bio,
unsigned long bio_flags);
void btrfs_set_range_writeback(void *private_data, u64 start, u64 end);
-int btrfs_page_mkwrite(struct vm_fault *vmf);
+vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf);
int btrfs_readpage(struct file *file, struct page *page);
void btrfs_evict_inode(struct inode *inode);
int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 0b86cf1..20bde86 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -8873,7 +8873,7 @@ static void btrfs_invalidatepage(struct page *page, unsigned int offset,
* beyond EOF, then the page is guaranteed safe against truncation until we
* unlock the page.
*/
-int btrfs_page_mkwrite(struct vm_fault *vmf)
+vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf)
{
struct page *page = vmf->page;
struct inode *inode = file_inode(vmf->vma->vm_file);
@@ -8885,8 +8885,9 @@ int btrfs_page_mkwrite(struct vm_fault *vmf)
char *kaddr;
unsigned long zero_start;
loff_t size;
- int ret;
+ int err;
int reserved = 0;
+ vm_fault_t ret;
u64 reserved_space;
u64 page_start;
u64 page_end;
@@ -8907,17 +8908,14 @@ int btrfs_page_mkwrite(struct vm_fault *vmf)
* end up waiting indefinitely to get a lock on the page currently
* being processed by btrfs_page_mkwrite() function.
*/
- ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
+ err = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
reserved_space);
- if (!ret) {
- ret = file_update_time(vmf->vma->vm_file);
+ if (!err) {
+ err = file_update_time(vmf->vma->vm_file);
reserved = 1;
}
- if (ret) {
- if (ret == -ENOMEM)
- ret = VM_FAULT_OOM;
- else /* -ENOSPC, -EIO, etc */
- ret = VM_FAULT_SIGBUS;
+ if (err) {
+ ret = vmf_error(err);
if (reserved)
goto out;
goto out_noreserve;
@@ -8976,15 +8974,15 @@ int btrfs_page_mkwrite(struct vm_fault *vmf)
EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
0, 0, &cached_state);

- ret = btrfs_set_extent_delalloc(inode, page_start, end, 0,
+ err = btrfs_set_extent_delalloc(inode, page_start, end, 0,
&cached_state, 0);
- if (ret) {
+ if (err) {
unlock_extent_cached(io_tree, page_start, page_end,
&cached_state);
ret = VM_FAULT_SIGBUS;
goto out_unlock;
}
- ret = 0;
+ err = 0;

/* page is wholly or partially inside EOF */
if (page_start + PAGE_SIZE > size)
@@ -9009,11 +9007,11 @@ int btrfs_page_mkwrite(struct vm_fault *vmf)
unlock_extent_cached(io_tree, page_start, page_end, &cached_state);

out_unlock:
- if (!ret) {
+ if (!err) {
btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE, true);
sb_end_pagefault(inode->i_sb);
extent_changeset_free(data_reserved);
- return VM_FAULT_LOCKED;
+ ret = VM_FAULT_LOCKED;
}
unlock_page(page);
out:
--
1.9.1