ovl: factor out ovl_free_entry() and ovl_stack_*() helpers

In preparation for moving lowerstack into ovl_inode.

Note that in ovl_lookup() the temp stack dentry refs are now cloned
into the final ovl_lowerstack instead of being transferred, so cleanup
always needs to call ovl_stack_free(stack).

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

diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index 31f889d27083ac8be8c4306a03b4bc5db67ae3d5..c237c8dbff09fdd41a7334c5a9e73fe772d2166f 100644 (file)
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -907,8 +907,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
 
        if (!d.stop && ovl_numlower(poe)) {
                err = -ENOMEM;
-               stack = kcalloc(ofs->numlayer - 1, sizeof(struct ovl_path),
-                               GFP_KERNEL);
+               stack = ovl_stack_alloc(ofs->numlayer - 1);
                if (!stack)
                        goto out_put_upper;
        }
@@ -1073,7 +1072,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
        if (!oe)
                goto out_put;
 
-       memcpy(ovl_lowerstack(oe), stack, sizeof(struct ovl_path) * ctr);
+       ovl_stack_cpy(ovl_lowerstack(oe), stack, ctr);
        dentry->d_fsdata = oe;
 
        if (upperopaque)
@@ -1131,18 +1130,16 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
                kfree(origin_path);
        }
        dput(index);
-       kfree(stack);
+       ovl_stack_free(stack, ctr);
        kfree(d.redirect);
        return d_splice_alias(inode, dentry);
 
 out_free_oe:
        dentry->d_fsdata = NULL;
-       kfree(oe);
+       ovl_free_entry(oe);
 out_put:
        dput(index);
-       for (i = 0; i < ctr; i++)
-               dput(stack[i].dentry);
-       kfree(stack);
+       ovl_stack_free(stack, ctr);
 out_put_upper:
        if (origin_path) {
                dput(origin_path->dentry);

diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 2b79a9398c1327e5d9916af2d252cc1386b21e37..4f83509a0294992fc5269df358630c5af894bea1 100644 (file)
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -373,7 +373,12 @@ int ovl_can_decode_fh(struct super_block *sb);
 struct dentry *ovl_indexdir(struct super_block *sb);
 bool ovl_index_all(struct super_block *sb);
 bool ovl_verify_lower(struct super_block *sb);
+struct ovl_path *ovl_stack_alloc(unsigned int n);
+void ovl_stack_cpy(struct ovl_path *dst, struct ovl_path *src, unsigned int n);
+void ovl_stack_put(struct ovl_path *stack, unsigned int n);
+void ovl_stack_free(struct ovl_path *stack, unsigned int n);
 struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
+void ovl_free_entry(struct ovl_entry *oe);
 bool ovl_dentry_remote(struct dentry *dentry);
 void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *realdentry);
 void ovl_dentry_init_reval(struct dentry *dentry, struct dentry *upperdentry);

diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h
index 0e009fa39d54436905ed864d21122771902754c0..608742f60037bae766e9fa9e14cfc8bb2b860fca 100644 (file)
--- a/fs/overlayfs/ovl_entry.h
+++ b/fs/overlayfs/ovl_entry.h
@@ -127,8 +127,6 @@ static inline struct ovl_path *ovl_lowerstack(struct ovl_entry *oe)
        return ovl_numlower(oe) ? oe->__lowerstack : NULL;
 }
 
-struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
-
 static inline struct ovl_entry *OVL_E(struct dentry *dentry)
 {
        return (struct ovl_entry *) dentry->d_fsdata;

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index baa970a2b3988f70020dba900739fdb1ba612d80..35ecea4b60b0cecabaaf88de989b7b36f082e830 100644 (file)
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -54,15 +54,6 @@ module_param_named(xino_auto, ovl_xino_auto_def, bool, 0644);
 MODULE_PARM_DESC(xino_auto,
                 "Auto enable xino feature");
 
-static void ovl_entry_stack_free(struct ovl_entry *oe)
-{
-       struct ovl_path *lowerstack = ovl_lowerstack(oe);
-       unsigned int i;
-
-       for (i = 0; i < ovl_numlower(oe); i++)
-               dput(lowerstack[i].dentry);
-}
-
 static bool ovl_metacopy_def = IS_ENABLED(CONFIG_OVERLAY_FS_METACOPY);
 module_param_named(metacopy, ovl_metacopy_def, bool, 0644);
 MODULE_PARM_DESC(metacopy,
@@ -73,7 +64,7 @@ static void ovl_dentry_release(struct dentry *dentry)
        struct ovl_entry *oe = dentry->d_fsdata;
 
        if (oe) {
-               ovl_entry_stack_free(oe);
+               ovl_stack_put(ovl_lowerstack(oe), ovl_numlower(oe));
                kfree_rcu(oe, rcu);
        }
 }
@@ -2070,8 +2061,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
        return 0;
 
 out_free_oe:
-       ovl_entry_stack_free(oe);
-       kfree(oe);
+       ovl_free_entry(oe);
 out_err:
        kfree(splitlower);
        path_put(&upperpath);

diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index a146c7ab8d8e6ae57528758bb98be5712d899762..4ff58f92100d44ac1c503e0ca435e80d053df513 100644 (file)
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -83,6 +83,34 @@ bool ovl_verify_lower(struct super_block *sb)
        return ofs->config.nfs_export && ofs->config.index;
 }
 
+struct ovl_path *ovl_stack_alloc(unsigned int n)
+{
+       return kcalloc(n, sizeof(struct ovl_path), GFP_KERNEL);
+}
+
+void ovl_stack_cpy(struct ovl_path *dst, struct ovl_path *src, unsigned int n)
+{
+       unsigned int i;
+
+       memcpy(dst, src, sizeof(struct ovl_path) * n);
+       for (i = 0; i < n; i++)
+               dget(src[i].dentry);
+}
+
+void ovl_stack_put(struct ovl_path *stack, unsigned int n)
+{
+       unsigned int i;
+
+       for (i = 0; stack && i < n; i++)
+               dput(stack[i].dentry);
+}
+
+void ovl_stack_free(struct ovl_path *stack, unsigned int n)
+{
+       ovl_stack_put(stack, n);
+       kfree(stack);
+}
+
 struct ovl_entry *ovl_alloc_entry(unsigned int numlower)
 {
        size_t size = offsetof(struct ovl_entry, __lowerstack[numlower]);
@@ -94,6 +122,12 @@ struct ovl_entry *ovl_alloc_entry(unsigned int numlower)
        return oe;
 }
 
+void ovl_free_entry(struct ovl_entry *oe)
+{
+       ovl_stack_put(ovl_lowerstack(oe), ovl_numlower(oe));
+       kfree(oe);
+}
+
 #define OVL_D_REVALIDATE (DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE)
 
 bool ovl_dentry_remote(struct dentry *dentry)