[PATCH AUTOSEL for 4.4 036/101] afs: Flush outstanding writes when an fd is closed

[alexander . levin]

From: David Howells <dhowe...@redhat.com>

[ Upstream commit 58fed94dfb17e89556b5705f20f90e5b2971b6a1 ]

Flush outstanding writes in afs when an fd is closed.  This is what NFS and
CIFS do.

Reported-by: Marc Dionne <marc.c.dio...@gmail.com>
Signed-off-by: David Howells <dhowe...@redhat.com>
Signed-off-by: Sasha Levin <alexander.le...@verizon.com>
---
 fs/afs/file.c     |  1 +
 fs/afs/internal.h |  1 +
 fs/afs/write.c    | 14 ++++++++++++++
 3 files changed, 16 insertions(+)

diff --git a/fs/afs/file.c b/fs/afs/file.c
index 999bc3caec92..cf8a07e282a6 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -29,6 +29,7 @@ static int afs_readpages(struct file *filp, struct 
address_space *mapping,
 
 const struct file_operations afs_file_operations = {
        .open           = afs_open,
+       .flush          = afs_flush,
        .release        = afs_release,
        .llseek         = generic_file_llseek,
        .read_iter      = generic_file_read_iter,
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 71d5982312f3..5cb5c320b966 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -749,6 +749,7 @@ extern int afs_writepages(struct address_space *, struct 
writeback_control *);
 extern void afs_pages_written_back(struct afs_vnode *, struct afs_call *);
 extern ssize_t afs_file_write(struct kiocb *, struct iov_iter *);
 extern int afs_writeback_all(struct afs_vnode *);
+extern int afs_flush(struct file *, fl_owner_t);
 extern int afs_fsync(struct file *, loff_t, loff_t, int);
 
 
diff --git a/fs/afs/write.c b/fs/afs/write.c
index 777ea2bbf401..cc46e8c1d46e 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -741,6 +741,20 @@ out:
 }
 
 /*
+ * Flush out all outstanding writes on a file opened for writing when it is
+ * closed.
+ */
+int afs_flush(struct file *file, fl_owner_t id)
+{
+       _enter("");
+
+       if ((file->f_mode & FMODE_WRITE) == 0)
+               return 0;
+
+       return vfs_fsync(file, 0);
+}
+
+/*
  * notification that a previously read-only page is about to become writable
  * - if it returns an error, the caller will deliver a bus error signal
  */
-- 
2.11.0