From 39d3d60a54df05a1a32fa71159d7a26a530dee6c Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Tue, 17 Jan 2017 06:34:56 +0200 Subject: ovl: introduce copy up waitqueue 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 Signed-off-by: Miklos Szeredi --- fs/overlayfs/util.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'fs/overlayfs/util.c') 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); +} -- cgit v1.1