From: Chengguang Xu <cgxu519@mykernel.net>
To: miklos@szeredi.hu, amir73il@gmail.com, jack@suse.cz
Cc: linux-unionfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Chengguang Xu <cgxu519@mykernel.net>
Subject: [RFC PATCH v2 2/8] ovl: implement ->writepages operation
Date: Sun, 25 Oct 2020 11:41:11 +0800 [thread overview]
Message-ID: <20201025034117.4918-3-cgxu519@mykernel.net> (raw)
In-Reply-To: <20201025034117.4918-1-cgxu519@mykernel.net>
Implement overlayfs' ->writepages operation so that
we can sync dirty data/metadata to upper filesystem.
Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
---
fs/overlayfs/inode.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index b584dca845ba..f27fc5be34df 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -11,6 +11,7 @@
#include <linux/posix_acl.h>
#include <linux/ratelimit.h>
#include <linux/fiemap.h>
+#include <linux/writeback.h>
#include "overlayfs.h"
@@ -516,7 +517,32 @@ static const struct inode_operations ovl_special_inode_operations = {
.update_time = ovl_update_time,
};
+static int ovl_writepages(struct address_space *mapping,
+ struct writeback_control *wbc)
+{
+ struct inode *upper_inode = ovl_inode_upper(mapping->host);
+ struct ovl_fs *ofs = mapping->host->i_sb->s_fs_info;
+ struct writeback_control tmp_wbc = *wbc;
+
+ if (!ovl_should_sync(ofs))
+ return 0;
+
+ /*
+ * for sync(2) writeback, it has a separate external IO
+ * completion path by checking PAGECACHE_TAG_WRITEBACK
+ * in pagecache, we have to set for_sync to 0 in thie case,
+ * let writeback waits completion after syncing individual
+ * dirty inode, because we haven't implemented overlayfs'
+ * own pagecache yet.
+ */
+ if (wbc->for_sync && (wbc->sync_mode == WB_SYNC_ALL))
+ tmp_wbc.for_sync = 0;
+
+ return sync_inode(upper_inode, &tmp_wbc);
+}
+
static const struct address_space_operations ovl_aops = {
+ .writepages = ovl_writepages,
/* For O_DIRECT dentry_open() checks f_mapping->a_ops->direct_IO */
.direct_IO = noop_direct_IO,
};
--
2.26.2
next prev parent reply other threads:[~2020-10-25 3:42 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-25 3:41 [RFC PATCH v2 0/8] implement containerized syncfs for overlayfs Chengguang Xu
2020-10-25 3:41 ` [RFC PATCH v2 1/8] ovl: setup overlayfs' private bdi Chengguang Xu
2020-10-25 3:41 ` Chengguang Xu [this message]
2020-11-02 17:17 ` [RFC PATCH v2 2/8] ovl: implement ->writepages operation Jan Kara
2020-11-04 12:18 ` Chengguang Xu
2020-11-05 13:55 ` Jan Kara
2020-11-06 5:57 ` Chengguang Xu
2020-10-25 3:41 ` [RFC PATCH v2 3/8] ovl: implement overlayfs' ->evict_inode operation Chengguang Xu
2020-10-25 3:41 ` [RFC PATCH v2 4/8] ovl: mark overlayfs' inode dirty on modification Chengguang Xu
2020-10-25 3:41 ` [RFC PATCH v2 5/8] ovl: mark overlayfs' inode dirty on shared writable mmap Chengguang Xu
2020-11-02 17:30 ` Jan Kara
2020-11-04 11:54 ` Chengguang Xu
2020-11-05 14:03 ` Jan Kara
2020-11-05 14:21 ` Amir Goldstein
2020-11-05 15:54 ` Jan Kara
2020-11-06 2:41 ` Chengguang Xu
2020-11-06 8:50 ` Jan Kara
2020-11-06 9:47 ` Chengguang Xu
2020-10-25 3:41 ` [RFC PATCH v2 6/8] ovl: implement overlayfs' ->write_inode operation Chengguang Xu
2020-10-25 3:41 ` [RFC PATCH v2 7/8] ovl: cache dirty overlayfs' inode Chengguang Xu
2020-10-25 3:41 ` [RFC PATCH v2 8/8] ovl: implement containerized syncfs for overlayfs Chengguang Xu
2020-10-30 15:46 ` [RFC PATCH v2 0/8] " Miklos Szeredi
2020-10-31 12:22 ` Chengguang Xu
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