ovl: deduplicate lowerdata and lowerstack[]

The ovl_inode contains a copy of lowerdata in lowerstack[], so the
lowerdata inode member can be removed.

Use accessors ovl_lowerdata*() to get the lowerdata whereever the member
was accessed directly.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 4dbf8d8..5239a5b 100644 (file)
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -1005,8 +1005,6 @@ void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip,
        oi->__upperdentry = oip->upperdentry;
        oi->oe = oip->oe;
        oi->redirect = oip->redirect;
-       if (oip->lowerdata)
-               oi->lowerdata = igrab(d_inode(oip->lowerdata));
 
        realinode = ovl_inode_real(inode);
        ovl_copyattr(inode);

diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index 317ab1e..8ea2a83 100644 (file)
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -1110,8 +1110,6 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
                        .oe = oe,
                        .index = index,
                        .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 8b38844..2ccd632 100644 (file)
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -656,7 +656,6 @@ struct ovl_inode_params {
        struct ovl_entry *oe;
        bool index;
        char *redirect;
-       struct dentry *lowerdata;
 };
 void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip,
                    unsigned long ino, int fsid);

diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h
index 0bb8ab3..548c93e 100644 (file)
--- a/fs/overlayfs/ovl_entry.h
+++ b/fs/overlayfs/ovl_entry.h
@@ -125,6 +125,20 @@ static inline struct ovl_path *ovl_lowerpath(struct ovl_entry *oe)
        return ovl_lowerstack(oe);
 }
 
+static inline struct ovl_path *ovl_lowerdata(struct ovl_entry *oe)
+{
+       struct ovl_path *lowerstack = ovl_lowerstack(oe);
+
+       return lowerstack ? &lowerstack[oe->__numlower - 1] : NULL;
+}
+
+static inline struct dentry *ovl_lowerdata_dentry(struct ovl_entry *oe)
+{
+       struct ovl_path *lowerdata = ovl_lowerdata(oe);
+
+       return lowerdata ? lowerdata->dentry : NULL;
+}
+
 /* private information held for every overlayfs dentry */
 static inline unsigned long *OVL_E_FLAGS(struct dentry *dentry)
 {
@@ -134,7 +148,7 @@ static inline unsigned long *OVL_E_FLAGS(struct dentry *dentry)
 struct ovl_inode {
        union {
                struct ovl_dir_cache *cache;    /* directory */
-               struct inode *lowerdata;        /* regular file */
+               /* place holder for non-dir */  /* regular file */
        };
        const char *redirect;
        u64 version;

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 1efc4f2..dace72e 100644 (file)
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -172,7 +172,6 @@ static struct inode *ovl_alloc_inode(struct super_block *sb)
        oi->flags = 0;
        oi->__upperdentry = NULL;
        oi->oe = NULL;
-       oi->lowerdata = NULL;
        mutex_init(&oi->lock);
 
        return &oi->vfs_inode;
@@ -195,8 +194,6 @@ static void ovl_destroy_inode(struct inode *inode)
        ovl_free_entry(oi->oe);
        if (S_ISDIR(inode->i_mode))
                ovl_dir_cache_free(inode);
-       else
-               iput(oi->lowerdata);
 }
 
 static void ovl_free_fs(struct ovl_fs *ofs)

diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 143e689..b6e66bf 100644 (file)
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -225,11 +225,11 @@ void ovl_path_lower(struct dentry *dentry, struct path *path)
 void ovl_path_lowerdata(struct dentry *dentry, struct path *path)
 {
        struct ovl_entry *oe = OVL_E(dentry);
-       struct ovl_path *lowerstack = ovl_lowerstack(oe);
+       struct ovl_path *lowerdata = ovl_lowerdata(oe);
 
        if (ovl_numlower(oe)) {
-               path->mnt = lowerstack[ovl_numlower(oe) - 1].layer->mnt;
-               path->dentry = lowerstack[ovl_numlower(oe) - 1].dentry;
+               path->mnt = lowerdata->layer->mnt;
+               path->dentry = lowerdata->dentry;
        } else {
                *path = (struct path) { };
        }
@@ -288,10 +288,7 @@ const struct ovl_layer *ovl_layer_lower(struct dentry *dentry)
  */
 struct dentry *ovl_dentry_lowerdata(struct dentry *dentry)
 {
-       struct ovl_entry *oe = OVL_E(dentry);
-
-       return ovl_numlower(oe) ?
-               ovl_lowerstack(oe)[ovl_numlower(oe) - 1].dentry : NULL;
+       return ovl_lowerdata_dentry(OVL_E(dentry));
 }
 
 struct dentry *ovl_dentry_real(struct dentry *dentry)
@@ -341,10 +338,12 @@ struct inode *ovl_inode_real(struct inode *inode)
 /* Return inode which contains lower data. Do not return metacopy */
 struct inode *ovl_inode_lowerdata(struct inode *inode)
 {
+       struct dentry *lowerdata = ovl_lowerdata_dentry(OVL_I_E(inode));
+
        if (WARN_ON(!S_ISREG(inode->i_mode)))
                return NULL;
 
-       return OVL_I(inode)->lowerdata ?: ovl_inode_lower(inode);
+       return lowerdata ? d_inode(lowerdata) : NULL;
 }
 
 /* Return real inode which contains data. Does not return metacopy inode */