From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f67.google.com ([74.125.82.67]:35199 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751152AbdAQEg0 (ORCPT ); Mon, 16 Jan 2017 23:36:26 -0500 From: Amir Goldstein To: Miklos Szeredi Cc: Al Viro , linux-unionfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v4 5/6] ovl: introduce copy up waitqueue Date: Tue, 17 Jan 2017 06:34:56 +0200 Message-Id: <1484627697-17262-6-git-send-email-amir73il@gmail.com> In-Reply-To: <1484627697-17262-1-git-send-email-amir73il@gmail.com> References: <1484627697-17262-1-git-send-email-amir73il@gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: The overlay sb 'copyup_wq' and overlay inode 'copying' condition variable are about to replace the upper sb rename_lock, as finer grained synchronization objects for concurrent copy up. Suggested-by: Miklos Szeredi Signed-off-by: Amir Goldstein --- fs/overlayfs/overlayfs.h | 2 ++ fs/overlayfs/ovl_entry.h | 2 ++ fs/overlayfs/super.c | 1 + fs/overlayfs/util.c | 30 ++++++++++++++++++++++++++++++ 4 files changed, 35 insertions(+) diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index 3822a90..741dc0b 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -178,6 +178,8 @@ void ovl_dentry_version_inc(struct dentry *dentry); u64 ovl_dentry_version_get(struct dentry *dentry); bool ovl_is_whiteout(struct dentry *dentry); struct file *ovl_path_open(struct path *path, int flags); +int ovl_copy_up_start(struct dentry *dentry); +void ovl_copy_up_end(struct dentry *dentry); /* namei.c */ int ovl_path_next(int idx, struct dentry *dentry, struct path *path); diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h index 65f24000..59614fa 100644 --- a/fs/overlayfs/ovl_entry.h +++ b/fs/overlayfs/ovl_entry.h @@ -28,6 +28,7 @@ struct ovl_fs { /* creds of process who forced instantiation of super block */ const struct cred *creator_cred; bool tmpfile; + wait_queue_head_t copyup_wq; }; /* private information held for every overlayfs dentry */ @@ -39,6 +40,7 @@ struct ovl_entry { u64 version; const char *redirect; bool opaque; + bool copying; }; struct rcu_head rcu; }; diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index ff05065..6792bb7 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -708,6 +708,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) if (!ufs) goto out; + init_waitqueue_head(&ufs->copyup_wq); ufs->config.redirect_dir = ovl_redirect_dir_def; err = ovl_parse_opt((char *) data, &ufs->config); if (err) diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index 952286f..01157d6 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -263,3 +263,33 @@ struct file *ovl_path_open(struct path *path, int flags) { return dentry_open(path, flags | O_NOATIME, current_cred()); } + +int ovl_copy_up_start(struct dentry *dentry) +{ + struct ovl_fs *ofs = dentry->d_sb->s_fs_info; + struct ovl_entry *oe = dentry->d_fsdata; + int err; + + spin_lock(&ofs->copyup_wq.lock); + err = wait_event_interruptible_locked(ofs->copyup_wq, !oe->copying); + if (!err) { + if (oe->__upperdentry) + err = 1; /* Already copied up */ + else + oe->copying = true; + } + spin_unlock(&ofs->copyup_wq.lock); + + return err; +} + +void ovl_copy_up_end(struct dentry *dentry) +{ + struct ovl_fs *ofs = dentry->d_sb->s_fs_info; + struct ovl_entry *oe = dentry->d_fsdata; + + spin_lock(&ofs->copyup_wq.lock); + oe->copying = false; + wake_up_locked(&ofs->copyup_wq); + spin_unlock(&ofs->copyup_wq.lock); +} -- 2.7.4