From 2664bd0897c2889258472a1ee922ef9d4c5fa58f Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Fri, 11 May 2018 11:49:30 -0400 Subject: ovl: Store lower data inode in ovl_inode Right now ovl_inode stores inode pointer for lower inode. This helps with quickly getting lower inode given overlay inode (ovl_inode_lower()). Now with metadata only copy-up, we can have metacopy inode in middle layer as well and inode containing data can be different from ->lower. I need to be able to open the real file in ovl_open_realfile() and for that I need to quickly find the lower data inode. Hence store lower data inode also in ovl_inode. Also provide an helper ovl_inode_lowerdata() to access this field. Signed-off-by: Vivek Goyal Reviewed-by: Amir Goldstein Signed-off-by: Miklos Szeredi --- fs/overlayfs/util.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'fs/overlayfs/util.c') diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index 4f9c2ecee74c..63311c536216 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -247,6 +247,14 @@ struct inode *ovl_inode_real(struct inode *inode) return ovl_inode_upper(inode) ?: ovl_inode_lower(inode); } +/* Return inode which contains lower data. Do not return metacopy */ +struct inode *ovl_inode_lowerdata(struct inode *inode) +{ + if (WARN_ON(!S_ISREG(inode->i_mode))) + return NULL; + + return OVL_I(inode)->lowerdata ?: ovl_inode_lower(inode); +} struct ovl_dir_cache *ovl_dir_cache(struct inode *inode) { @@ -381,7 +389,7 @@ void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect) } void ovl_inode_init(struct inode *inode, struct dentry *upperdentry, - struct dentry *lowerdentry) + struct dentry *lowerdentry, struct dentry *lowerdata) { struct inode *realinode = d_inode(upperdentry ?: lowerdentry); @@ -389,6 +397,8 @@ void ovl_inode_init(struct inode *inode, struct dentry *upperdentry, OVL_I(inode)->__upperdentry = upperdentry; if (lowerdentry) OVL_I(inode)->lower = igrab(d_inode(lowerdentry)); + if (lowerdata) + OVL_I(inode)->lowerdata = igrab(d_inode(lowerdata)); ovl_copyattr(realinode, inode); ovl_copyflags(realinode, inode); -- cgit v1.2.3