| Message ID | 20201113065555.147276-8-cgxu519@mykernel.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | implement containerized syncfs for overlayfs | expand |
On Fri, Nov 13, 2020 at 7:57 AM Chengguang Xu <cgxu519@mykernel.net> wrote: > > Now drop overlayfs' inode will sync dirty data, > so we change to only drop clean inode. I don't understand what happens here. Please add more explanation. Thanks, Miklos
---- 在 星期五, 2021-04-09 21:50:35 Miklos Szeredi <miklos@szeredi.hu> 撰写 ---- > On Fri, Nov 13, 2020 at 7:57 AM Chengguang Xu <cgxu519@mykernel.net> wrote: > > > > Now drop overlayfs' inode will sync dirty data, > > so we change to only drop clean inode. > > I don't understand what happens here. Please add more explanation. In iput_final(), clean overlayfs inode will directly drop as the same as before, dirty overlayfs inode will keep in the cache to wait writeback to sync dirty data and then add to lru list to wait reclaim. The purpose of doing this is to keep compatible behavior with original one, because without this series, dropping overlayfs inode will not trigger syncing underlying dirty inode. Thanks, Chengguang
On Tue, Apr 13, 2021 at 4:14 AM Chengguang Xu <cgxu519@mykernel.net> wrote: > > ---- 在 星期五, 2021-04-09 21:50:35 Miklos Szeredi <miklos@szeredi.hu> 撰写 ---- > > On Fri, Nov 13, 2020 at 7:57 AM Chengguang Xu <cgxu519@mykernel.net> wrote: > > > > > > Now drop overlayfs' inode will sync dirty data, > > > so we change to only drop clean inode. > > > > I don't understand what happens here. Please add more explanation. > > In iput_final(), clean overlayfs inode will directly drop as the same as before, > dirty overlayfs inode will keep in the cache to wait writeback to sync dirty data > and then add to lru list to wait reclaim. > > The purpose of doing this is to keep compatible behavior with original one, > because without this series, dropping overlayfs inode will not trigger syncing > underlying dirty inode. I get it now. Can you please update the patch header with this description? Thanks, Miklos
---- 在 星期二, 2021-04-13 16:43:27 Miklos Szeredi <miklos@szeredi.hu> 撰写 ---- > On Tue, Apr 13, 2021 at 4:14 AM Chengguang Xu <cgxu519@mykernel.net> wrote: > > > > ---- 在 星期五, 2021-04-09 21:50:35 Miklos Szeredi <miklos@szeredi.hu> 撰写 ---- > > > On Fri, Nov 13, 2020 at 7:57 AM Chengguang Xu <cgxu519@mykernel.net> wrote: > > > > > > > > Now drop overlayfs' inode will sync dirty data, > > > > so we change to only drop clean inode. > > > > > > I don't understand what happens here. Please add more explanation. > > > > In iput_final(), clean overlayfs inode will directly drop as the same as before, > > dirty overlayfs inode will keep in the cache to wait writeback to sync dirty data > > and then add to lru list to wait reclaim. > > > > The purpose of doing this is to keep compatible behavior with original one, > > because without this series, dropping overlayfs inode will not trigger syncing > > underlying dirty inode. > > I get it now. Can you please update the patch header with this description? > No problem, I'll update commit log in next version. Thanks, Chengguang
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 82e001b97f38..982b3954b47c 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -425,11 +425,20 @@ static void ovl_evict_inode(struct inode *inode) clear_inode(inode); } +static int ovl_drop_inode(struct inode *inode) +{ + struct inode *upper = ovl_inode_upper(inode); + + if (!upper || !(inode->i_state & I_DIRTY_ALL)) + return 1; + return generic_drop_inode(inode); +} + 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, + .drop_inode = ovl_drop_inode, .evict_inode = ovl_evict_inode, .write_inode = ovl_write_inode, .put_super = ovl_put_super,
Now drop overlayfs' inode will sync dirty data, so we change to only drop clean inode. Signed-off-by: Chengguang Xu <cgxu519@mykernel.net> --- fs/overlayfs/super.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)