Merge tag 'for-4.18-part2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

- error handling fixup for one of the new ioctls from 1st pull

- fix for device-replace that incorrectly uses inode pages and can mess
up compressed extents in some cases

- fiemap fix for reporting incorrect number of extents

- vm_fault_t type conversion

* tag 'for-4.18-part2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: scrub: Don't use inode pages for device replace
btrfs: change return type of btrfs_page_mkwrite to vm_fault_t
Btrfs: fiemap: pass correct bytenr when fm_extent_count is zero
btrfs: Check error of btrfs_iget in btrfs_search_path_in_tree_user

fs/btrfs/ctree.h

···
 			 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);

fs/btrfs/extent_io.c

···
 			offset_in_extent = em_start - em->start;
 		em_end = extent_map_end(em);
 		em_len = em_end - em_start;
-		disko = 0;
+		disko = em->block_start + offset_in_extent;
 		flags = 0;
 
 		/*
···
 		} else if (fieinfo->fi_extents_max) {
 			u64 bytenr = em->block_start -
 				(em->start - em->orig_start);
-
-			disko = em->block_start + offset_in_extent;
 
 			/*
 			 * As btrfs supports shared space, this information

fs/btrfs/inode.c

···
  * 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);
···
 	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;
···
 	 * 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;
···
 			  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)
···
 	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);

fs/btrfs/ioctl.c

···
 			}
 
 			temp_inode = btrfs_iget(sb, &key2, root, NULL);
+			if (IS_ERR(temp_inode)) {
+				ret = PTR_ERR(temp_inode);
+				goto out;
+			}
 			ret = inode_permission(temp_inode, MAY_READ | MAY_EXEC);
 			iput(temp_inode);
 			if (ret) {

fs/btrfs/scrub.c

···
 			have_csum = scrub_find_csum(sctx, logical, csum);
 			if (have_csum == 0)
 				++sctx->stat.no_csum;
-			if (sctx->is_dev_replace && !have_csum) {
+			if (0 && sctx->is_dev_replace && !have_csum) {
 				ret = copy_nocow_pages(sctx, logical, l,
 						       mirror_num,
 						      physical_for_dev_replace);