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 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 index 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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