Revert "nfs: nfs_file_write() should check for writeback errors"

hulk inclusion
category: bugfix
bugzilla: 186345, https://gitee.com/openeuler/kernel/issues/I4T2WV
CVE: NA

--------------------------------

This reverts commit ce368536.

filemap_sample_wb_err() will return 0 if nobody has seen the error yet,
then filemap_check_wb_err() will return the unchanged writeback error,
async write() will become sync write().

Reproducer:
        nfs server               |       nfs client
 --------------------------------|----------------------------------------------
 # No space left on server       |
 fallocate -l 100G /server/nospc |
                                 |
                                 | mount -t nfs $nfs_server_ip:/ /mnt
                                 |
                                 | # Expected error: No space left on device
                                 | dd if=/dev/zero of=/mnt/file count=1 ibs=1K
                                 |
                                 | # Release space on mountpoint
                                 | rm /mnt/nospc
                                 |
                                 | # Very very slow
                                 | dd if=/dev/zero of=/mnt/file count=1 ibs=1K
Signed-off-by: NChenXiaoSong <chenxiaosong2@huawei.com>
Reviewed-by: NZhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

fs/nfs/file.c

@@ -587,14 +587,12 @@ static const struct vm_operations_struct nfs_file_vm_ops = {
 	.page_mkwrite = nfs_vm_page_mkwrite,
 };
 
-static int nfs_need_check_write(struct file *filp, struct inode *inode,
-				int error)
+static int nfs_need_check_write(struct file *filp, struct inode *inode)
 {
 	struct nfs_open_context *ctx;
 
 	ctx = nfs_file_open_context(filp);
-	if (nfs_error_is_fatal_on_server(error) ||
-	    nfs_ctx_key_to_expire(ctx, inode))
+	if (nfs_ctx_key_to_expire(ctx, inode))
 		return 1;
 	return 0;
 }
@@ -605,8 +603,6 @@ ssize_t nfs_file_write(struct kiocb *iocb, struct iov_iter *from)
 	struct inode *inode = file_inode(file);
 	unsigned long written = 0;
 	ssize_t result;
-	errseq_t since;
-	int error;
 
 	result = nfs_key_timeout_notify(file, inode);
 	if (result)
@@ -631,7 +627,6 @@ ssize_t nfs_file_write(struct kiocb *iocb, struct iov_iter *from)
 	if (iocb->ki_pos > i_size_read(inode))
 		nfs_revalidate_mapping(inode, file->f_mapping);
 
-	since = filemap_sample_wb_err(file->f_mapping);
 	nfs_start_io_write(inode);
 	result = generic_write_checks(iocb, from);
 	if (result > 0) {
@@ -650,8 +645,7 @@ ssize_t nfs_file_write(struct kiocb *iocb, struct iov_iter *from)
 		goto out;
 
 	/* Return error values */
-	error = filemap_check_wb_err(file->f_mapping, since);
-	if (nfs_need_check_write(file, inode, error)) {
+	if (nfs_need_check_write(file, inode)) {
 		int err = nfs_wb_all(inode);
 		if (err < 0)
 			result = err;