btrfs: change return type of btrfs_page_mkwrite to vm_fault_t

Use the 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.

Reference commit 1c8f422059ae ("mm: change return type to vm_fault_t")

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

Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index f4bf7874c24a4d63609a30a966d14f9db0a323e0..118346aceea9607ff98410df2764614f24f4505d 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3197,7 +3197,7 @@ 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 89b2082017830942e040063a2ca000d1a10f75df..c12b7a6e534a643392ebc0cc8437912a614437ce 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -8872,7 +8872,7 @@ 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);
@@ -8884,7 +8884,8 @@ int btrfs_page_mkwrite(struct vm_fault *vmf)
        char *kaddr;
        unsigned long zero_start;
        loff_t size;
-       int ret;
+       vm_fault_t ret;
+       int ret2;
        int reserved = 0;
        u64 reserved_space;
        u64 page_start;
@@ -8906,17 +8907,14 @@ 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,
+       ret2 = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
                                           reserved_space);
-       if (!ret) {
-               ret = file_update_time(vmf->vma->vm_file);
+       if (!ret2) {
+               ret2 = 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 (ret2) {
+               ret = vmf_error(ret2);
                if (reserved)
                        goto out;
                goto out_noreserve;
@@ -8975,15 +8973,15 @@ 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,
+       ret2 = btrfs_set_extent_delalloc(inode, page_start, end, 0,
                                        &cached_state, 0);
-       if (ret) {
+       if (ret2) {
                unlock_extent_cached(io_tree, page_start, page_end,
                                     &cached_state);
                ret = VM_FAULT_SIGBUS;
                goto out_unlock;
        }
-       ret = 0;
+       ret2 = 0;
 
        /* page is wholly or partially inside EOF */
        if (page_start + PAGE_SIZE > size)
@@ -9008,7 +9006,7 @@ int btrfs_page_mkwrite(struct vm_fault *vmf)
        unlock_extent_cached(io_tree, page_start, page_end, &cached_state);
 
 out_unlock:
-       if (!ret) {
+       if (!ret2) {
                btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE, true);
                sb_end_pagefault(inode->i_sb);
                extent_changeset_free(data_reserved);