[PATCH 5.7 150/204] nfs: ensure correct writeback errors are returned on close()

Greg Kroah-Hartman
2020-08-20T09:41:49Z

From: Scott Mayhew <smayhew@redhat.com>

[ Upstream commit 67dd23f9e6fbaf163431912ef5599c5e0693476c ]

nfs_wb_all() calls filemap_write_and_wait(), which uses
filemap_check_errors() to determine the error to return.
filemap_check_errors() only looks at the mapping->flags and will
therefore only return either -ENOSPC or -EIO. To ensure that the
correct error is returned on close(), nfs{,4}_file_flush() should call
filemap_check_wb_err() which looks at the errseq value in
mapping->wb_err without consuming it.

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 | 5 ++++-
fs/nfs/nfs4file.c | 5 ++++-
2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index f96367a2463e3..d72496efa17b0 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -140,6 +140,7 @@ static int
nfs_file_flush(struct file *file, fl_owner_t id)
{
struct inode *inode = file_inode(file);
+ errseq_t since;

dprintk("NFS: flush(%pD2)\n", file);

@@ -148,7 +149,9 @@ nfs_file_flush(struct file *file, fl_owner_t id)
return 0;

/* Flush writes to the server and return any errors */
- return nfs_wb_all(inode);
+ since = filemap_sample_wb_err(file->f_mapping);
+ nfs_wb_all(inode);
+ return filemap_check_wb_err(file->f_mapping, since);
}

ssize_t
diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
index 8e5d6223ddd35..a339707654673 100644
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -110,6 +110,7 @@ static int
nfs4_file_flush(struct file *file, fl_owner_t id)
{
struct inode *inode = file_inode(file);
+ errseq_t since;

dprintk("NFS: flush(%pD2)\n", file);

@@ -125,7 +126,9 @@ nfs4_file_flush(struct file *file, fl_owner_t id)
return filemap_fdatawrite(file->f_mapping);

/* Flush writes to the server and return any errors */
- return nfs_wb_all(inode);
+ since = filemap_sample_wb_err(file->f_mapping);
+ nfs_wb_all(inode);
+ return filemap_check_wb_err(file->f_mapping, since);
}

#ifdef CONFIG_NFS_V4_2
--
2.25.1