[PATCH 5.7 157/204] nfs: nfs_file_write() should check for writeback errors

Greg Kroah-Hartman
2020-08-20T12:55:11Z

From: Scott Mayhew <smayhew@redhat.com>

[ Upstream commit ce368536dd614452407dc31e2449eb84681a06af ]

The NFS_CONTEXT_ERROR_WRITE flag (as well as the check of said flag) was
removed by commit 6fbda89b257f. The absence of an error check allows
writes to be continually queued up for a server that may no longer be
able to handle them. Fix it by adding an error check using the generic
error reporting functions.

Fixes: 6fbda89b257f ("NFS: Replace custom error reporting mechanism with generic one")
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/nfs/file.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index d72496efa17b0..63940a7a70be1 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -590,12 +590,14 @@ 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)
+static int nfs_need_check_write(struct file *filp, struct inode *inode,
+ int error)
{
struct nfs_open_context *ctx;

ctx = nfs_file_open_context(filp);
- if (nfs_ctx_key_to_expire(ctx, inode))
+ if (nfs_error_is_fatal_on_server(error) ||
+ nfs_ctx_key_to_expire(ctx, inode))
return 1;
return 0;
}
@@ -606,6 +608,8 @@ 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)
@@ -630,6 +634,7 @@ 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) {
@@ -648,7 +653,8 @@ ssize_t nfs_file_write(struct kiocb *iocb, struct iov_iter *from)
goto out;

/* Return error values */
- if (nfs_need_check_write(file, inode)) {
+ error = filemap_check_wb_err(file->f_mapping, since);
+ if (nfs_need_check_write(file, inode, error)) {
int err = nfs_wb_all(inode);
if (err < 0)
result = err;
--
2.25.1