Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley
        Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United
        Kingdom.
        Registered in England and Wales under Company Registration No. 3798903
Subject: [PATCH 05/64] netfs: Pass a flag to ->prepare_write() to say if
 there's no alloc'd space
From:   David Howells <dhowells@redhat.com>
To:     linux-cachefs@redhat.com
Cc:     dhowells@redhat.com, Trond Myklebust <trondmy@hammerspace.com>,
        Anna Schumaker <anna.schumaker@netapp.com>,
        Steve French <sfrench@samba.org>,
        Dominique Martinet <asmadeus@codewreck.org>,
        Jeff Layton <jlayton@kernel.org>,
        Matthew Wilcox <willy@infradead.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Omar Sandoval <osandov@osandov.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        linux-afs@lists.infradead.org, linux-nfs@vger.kernel.org,
        linux-cifs@vger.kernel.org, ceph-devel@vger.kernel.org,
        v9fs-developer@lists.sourceforge.net,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Date:   Mon, 29 Nov 2021 14:23:51 +0000
Message-ID: <163819583123.215744.12783808230464471417.stgit@warthog.procyon.org.uk>
In-Reply-To: <163819575444.215744.318477214576928110.stgit@warthog.procyon.org.uk>
References: <163819575444.215744.318477214576928110.stgit@warthog.procyon.org.uk>
User-Agent: StGit/0.23
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit
Precedence: bulk

Pass a flag to ->prepare_write() to indicate if there's definitely no
space allocated in the cache yet (for instance if we've already checked as
we were asked to do a read).

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
---

 fs/netfs/read_helper.c |    2 +-
 include/linux/netfs.h  |    3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/netfs/read_helper.c b/fs/netfs/read_helper.c
index 9320a42dfaf9..7dc79fa8a1f3 100644
--- a/fs/netfs/read_helper.c
+++ b/fs/netfs/read_helper.c
@@ -323,7 +323,7 @@ static void netfs_rreq_do_write_to_cache(struct netfs_read_request *rreq)
 		}
 
 		ret = cres->ops->prepare_write(cres, &subreq->start, &subreq->len,
-					       rreq->i_size);
+					       rreq->i_size, true);
 		if (ret < 0) {
 			trace_netfs_failure(rreq, subreq, ret, netfs_fail_prepare_write);
 			trace_netfs_sreq(subreq, netfs_sreq_trace_write_skip);
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index ca0683b9e3d1..1ea22fc48818 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -232,7 +232,8 @@ struct netfs_cache_ops {
 	 * actually do.
 	 */
 	int (*prepare_write)(struct netfs_cache_resources *cres,
-			     loff_t *_start, size_t *_len, loff_t i_size);
+			     loff_t *_start, size_t *_len, loff_t i_size,
+			     bool no_space_allocated_yet);
 };
 
 struct readahead_control;