Re: [RFC PATCH V6 3/7] ovl: implement overlayfs' own ->write_inode operation
From: Jan Kara <jack@suse.cz>
Date: 2021-11-26 09:16:33
Also in:
linux-unionfs, lkml
On Mon 22-11-21 11:00:34, Chengguang Xu wrote:
From: Chengguang Xu <redacted> Sync dirty data and meta of upper inode in overlayfs' ->write_inode() and redirty overlayfs' inode. Signed-off-by: Chengguang Xu <redacted>
Looks good. I'm still not 100% convinced keeping inodes dirty all the time will not fire back in excessive writeback activity (e.g. flush worker will traverse the list of all dirty inodes every 30 seconds and try to write them) but I guess we can start with this and if people complain, dirtiness handling can be improved. So feel free to add: Reviewed-by: Jan Kara <jack@suse.cz> Honza
quoted hunk ↗ jump to hunk
--- fs/overlayfs/super.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+)diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 18a12088a37b..12acf0ec7395 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c@@ -15,6 +15,7 @@ #include <linux/seq_file.h> #include <linux/posix_acl_xattr.h> #include <linux/exportfs.h> +#include <linux/writeback.h> #include "overlayfs.h" MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");@@ -406,12 +407,32 @@ static int ovl_remount(struct super_block *sb, int *flags, char *data) return ret; } +static int ovl_write_inode(struct inode *inode, + struct writeback_control *wbc) +{ + struct ovl_fs *ofs = inode->i_sb->s_fs_info; + struct inode *upper_inode = ovl_inode_upper(inode); + int ret = 0; + + if (!upper_inode) + return 0; + + if (!ovl_should_sync(ofs)) + return 0; + + ret = write_inode_now(upper_inode, wbc->sync_mode == WB_SYNC_ALL); + mark_inode_dirty(inode); + + return ret; +} + static const struct super_operations ovl_super_operations = { .alloc_inode = ovl_alloc_inode, .free_inode = ovl_free_inode, .destroy_inode = ovl_destroy_inode, .drop_inode = generic_delete_inode, .put_super = ovl_put_super, + .write_inode = ovl_write_inode, .sync_fs = ovl_sync_fs, .statfs = ovl_statfs, .show_options = ovl_show_options,-- 2.27.0
-- Jan Kara [off-list ref] SUSE Labs, CR