[PATCH 76/78] filemap: use ->f_mapping over ->i_mapping consistently

[Christoph Hellwig]

Use file->f_mapping in all functions that have a struct file available
to properly handle the case where file_inode(file)->i_mapping !=
inode->i_mapping.

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 mm/filemap.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/mm/filemap.c b/mm/filemap.c
index d5e7c2029d16b4..3e3531a757f8db 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2887,13 +2887,13 @@ EXPORT_SYMBOL(filemap_map_pages);
 vm_fault_t filemap_page_mkwrite(struct vm_fault *vmf)
 {
 	struct page *page = vmf->page;
-	struct inode *inode = file_inode(vmf->vma->vm_file);
+	struct inode *inode = vmf->vma->vm_file->f_mapping->host;
 	vm_fault_t ret = VM_FAULT_LOCKED;
 
 	sb_start_pagefault(inode->i_sb);
 	file_update_time(vmf->vma->vm_file);
 	lock_page(page);
-	if (page->mapping != inode->i_mapping) {
+	if (page->mapping != vmf->vma->vm_file->f_mapping) {
 		unlock_page(page);
 		ret = VM_FAULT_NOPAGE;
 		goto out;
@@ -3149,10 +3149,9 @@ void dio_warn_stale_pagecache(struct file *filp)
 {
 	static DEFINE_RATELIMIT_STATE(_rs, 86400 * HZ, DEFAULT_RATELIMIT_BURST);
 	char pathname[128];
-	struct inode *inode = file_inode(filp);
 	char *path;
 
-	errseq_set(&inode->i_mapping->wb_err, -EIO);
+	errseq_set(&filp->f_mapping->wb_err, -EIO);
 	if (__ratelimit(&_rs)) {
 		path = file_path(filp, pathname, sizeof(pathname));
 		if (IS_ERR(path))
@@ -3179,7 +3178,7 @@ generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from)
 
 	if (iocb->ki_flags & IOCB_NOWAIT) {
 		/* If there are pages to writeback, return */
-		if (filemap_range_has_page(inode->i_mapping, pos,
+		if (filemap_range_has_page(file->f_mapping, pos,
 					   pos + write_len - 1))
 			return -EAGAIN;
 	} else {
-- 
2.29.2