From: Vivek Goyal <[email protected]> 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 <[email protected]> Reviewed-by: Amir Goldstein <[email protected]> Signed-off-by: Miklos Szeredi <[email protected]> --- fs/overlayfs/inode.c | 2 +- fs/overlayfs/namei.c | 2 ++ fs/overlayfs/overlayfs.h | 4 +++- fs/overlayfs/ovl_entry.h | 5 ++++- fs/overlayfs/super.c | 8 ++++++-- fs/overlayfs/util.c | 12 +++++++++++- 6 files changed, 27 insertions(+), 6 deletions(-) diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 6a6693150c37..d4e643e9098b 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -864,7 +864,7 @@ struct inode *ovl_get_inode(struct super_block *sb, } } ovl_fill_inode(inode, realinode->i_mode, realinode->i_rdev, ino, fsid); - ovl_inode_init(inode, upperdentry, lowerdentry); + ovl_inode_init(inode, upperdentry, lowerdentry, oip->lowerdata); if (upperdentry && ovl_is_impuredir(upperdentry)) ovl_set_flag(OVL_IMPURE, inode); diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c index fcf0eb40d94b..b28b255ea8e2 100644 --- a/fs/overlayfs/namei.c +++ b/fs/overlayfs/namei.c @@ -1080,6 +1080,8 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, .index = index, .numlower = ctr, .redirect = upperredirect, + .lowerdata = (ctr > 1 && !d.is_dir) ? + stack[ctr - 1].dentry : NULL, }; inode = ovl_get_inode(dentry->d_sb, &oip); diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index ae06fd531b75..558a1b444286 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -227,6 +227,7 @@ struct dentry *ovl_dentry_real(struct dentry *dentry); struct dentry *ovl_i_dentry_upper(struct inode *inode); struct inode *ovl_inode_upper(struct inode *inode); struct inode *ovl_inode_lower(struct inode *inode); +struct inode *ovl_inode_lowerdata(struct inode *inode); struct inode *ovl_inode_real(struct inode *inode); struct ovl_dir_cache *ovl_dir_cache(struct inode *inode); void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache); @@ -246,7 +247,7 @@ bool ovl_redirect_dir(struct super_block *sb); const char *ovl_dentry_get_redirect(struct dentry *dentry); 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); void ovl_inode_update(struct inode *inode, struct dentry *upperdentry); void ovl_dir_modified(struct dentry *dentry, bool impurity); u64 ovl_dentry_version_get(struct dentry *dentry); @@ -361,6 +362,7 @@ struct ovl_inode_params { struct dentry *index; unsigned int numlower; char *redirect; + struct dentry *lowerdata; }; struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev); struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real, diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h index da65118a0567..6d02ab1f8811 100644 --- a/fs/overlayfs/ovl_entry.h +++ b/fs/overlayfs/ovl_entry.h @@ -90,7 +90,10 @@ static inline struct ovl_entry *OVL_E(struct dentry *dentry) } struct ovl_inode { - struct ovl_dir_cache *cache; + union { + struct ovl_dir_cache *cache; /* directory */ + struct inode *lowerdata; /* regular file */ + }; const char *redirect; u64 version; unsigned long flags; diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index d96530717702..e0326a686f45 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -187,6 +187,7 @@ static struct inode *ovl_alloc_inode(struct super_block *sb) oi->flags = 0; oi->__upperdentry = NULL; oi->lower = NULL; + oi->lowerdata = NULL; mutex_init(&oi->lock); return &oi->vfs_inode; @@ -205,8 +206,11 @@ static void ovl_destroy_inode(struct inode *inode) dput(oi->__upperdentry); iput(oi->lower); + if (S_ISDIR(inode->i_mode)) + ovl_dir_cache_free(inode); + else + iput(oi->lowerdata); kfree(oi->redirect); - ovl_dir_cache_free(inode); mutex_destroy(&oi->lock); call_rcu(&inode->i_rcu, ovl_i_callback); @@ -1509,7 +1513,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) ovl_dentry_set_flag(OVL_E_CONNECTED, root_dentry); ovl_set_upperdata(d_inode(root_dentry)); ovl_inode_init(d_inode(root_dentry), upperpath.dentry, - ovl_dentry_lower(root_dentry)); + ovl_dentry_lower(root_dentry), NULL); sb->s_root = root_dentry; 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); -- 2.14.3
