[PATCH 4.6 43/56] fuse: fuse_flush must check mapping->flags for errors

[Greg Kroah-Hartman]

4.6-stable review patch.  If anyone has any objections, please let me know.

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

From: Maxim Patlasov <mpatla...@virtuozzo.com>

commit 9ebce595f63a407c5cec98f98f9da8459b73740a upstream.

fuse_flush() calls write_inode_now() that triggers writeback, but actual
writeback will happen later, on fuse_sync_writes(). If an error happens,
fuse_writepage_end() will set error bit in mapping->flags. So, we have to
check mapping->flags after fuse_sync_writes().

Signed-off-by: Maxim Patlasov <mpatla...@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszer...@redhat.com>
Fixes: 4d99ff8f12eb ("fuse: Turn writeback cache on")
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 fs/fuse/file.c |    9 +++++++++
 1 file changed, 9 insertions(+)

--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -417,6 +417,15 @@ static int fuse_flush(struct file *file,
        fuse_sync_writes(inode);
        inode_unlock(inode);
 
+       if (test_bit(AS_ENOSPC, &file->f_mapping->flags) &&
+           test_and_clear_bit(AS_ENOSPC, &file->f_mapping->flags))
+               err = -ENOSPC;
+       if (test_bit(AS_EIO, &file->f_mapping->flags) &&
+           test_and_clear_bit(AS_EIO, &file->f_mapping->flags))
+               err = -EIO;
+       if (err)
+               return err;
+
        req = fuse_get_req_nofail_nopages(fc, file);
        memset(&inarg, 0, sizeof(inarg));
        inarg.fh = ff->fh;