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-rw-r--r--fs/overlayfs/copy_up.c1
-rw-r--r--fs/overlayfs/dir.c3
-rw-r--r--fs/overlayfs/inode.c11
-rw-r--r--fs/overlayfs/overlayfs.h18
-rw-r--r--fs/overlayfs/super.c44
5 files changed, 40 insertions, 37 deletions
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index 80aa6f1eb336..54e5d6681786 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -292,6 +292,7 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir,
goto out_cleanup;
ovl_dentry_update(dentry, newdentry);
+ ovl_inode_update(d_inode(dentry), d_inode(newdentry));
newdentry = NULL;
/*
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index b4eac8173f93..96b1bdcf3674 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -167,6 +167,7 @@ static void ovl_instantiate(struct dentry *dentry, struct inode *inode,
{
ovl_dentry_version_inc(dentry->d_parent);
ovl_dentry_update(dentry, newdentry);
+ ovl_inode_update(inode, d_inode(newdentry));
ovl_copyattr(newdentry->d_inode, inode);
d_instantiate(dentry, inode);
}
@@ -416,7 +417,7 @@ static int ovl_create_or_link(struct dentry *dentry, int mode, dev_t rdev,
};
err = -ENOMEM;
- inode = ovl_new_inode(dentry->d_sb, mode, dentry->d_fsdata);
+ inode = ovl_new_inode(dentry->d_sb, mode);
if (!inode)
goto out;
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 0598c169ce41..2bdd3cae0f71 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -117,15 +117,12 @@ static int ovl_getattr(struct vfsmount *mnt, struct dentry *dentry,
int ovl_permission(struct inode *inode, int mask)
{
- struct ovl_entry *oe = inode->i_private;
bool is_upper;
- struct dentry *realdentry = ovl_entry_real(oe, &is_upper);
- struct inode *realinode;
+ struct inode *realinode = ovl_inode_real(inode, &is_upper);
const struct cred *old_cred;
int err;
/* Careful in RCU walk mode */
- realinode = d_inode_rcu(realdentry);
if (!realinode) {
WARN_ON(!(mask & MAY_NOT_BLOCK));
return -ECHILD;
@@ -312,7 +309,7 @@ out:
struct posix_acl *ovl_get_acl(struct inode *inode, int type)
{
- struct inode *realinode = ovl_inode_real(inode);
+ struct inode *realinode = ovl_inode_real(inode, NULL);
const struct cred *old_cred;
struct posix_acl *acl;
@@ -412,8 +409,7 @@ static const struct inode_operations ovl_symlink_inode_operations = {
.update_time = ovl_update_time,
};
-struct inode *ovl_new_inode(struct super_block *sb, umode_t mode,
- struct ovl_entry *oe)
+struct inode *ovl_new_inode(struct super_block *sb, umode_t mode)
{
struct inode *inode;
@@ -424,7 +420,6 @@ struct inode *ovl_new_inode(struct super_block *sb, umode_t mode,
inode->i_ino = get_next_ino();
inode->i_mode = mode;
inode->i_flags |= S_NOCMTIME;
- inode->i_private = oe;
mode &= S_IFMT;
switch (mode) {
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index fb73c09a84e7..6410209ea616 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -27,6 +27,8 @@ enum ovl_path_type {
#define OVL_XATTR_PRE_LEN 16
#define OVL_XATTR_OPAQUE OVL_XATTR_PRE_NAME"opaque"
+#define OVL_ISUPPER_MASK 1UL
+
static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
{
int err = vfs_rmdir(dir, dentry);
@@ -131,6 +133,16 @@ static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry)
return err;
}
+static inline struct inode *ovl_inode_real(struct inode *inode, bool *is_upper)
+{
+ unsigned long x = (unsigned long) READ_ONCE(inode->i_private);
+
+ if (is_upper)
+ *is_upper = x & OVL_ISUPPER_MASK;
+
+ return (struct inode *) (x & ~OVL_ISUPPER_MASK);
+}
+
enum ovl_path_type ovl_path_type(struct dentry *dentry);
u64 ovl_dentry_version_get(struct dentry *dentry);
void ovl_dentry_version_inc(struct dentry *dentry);
@@ -141,8 +153,6 @@ int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
struct dentry *ovl_dentry_upper(struct dentry *dentry);
struct dentry *ovl_dentry_lower(struct dentry *dentry);
struct dentry *ovl_dentry_real(struct dentry *dentry);
-struct dentry *ovl_entry_real(struct ovl_entry *oe, bool *is_upper);
-struct inode *ovl_inode_real(struct inode *inode);
struct vfsmount *ovl_entry_mnt_real(struct ovl_entry *oe, struct inode *inode,
bool is_upper);
struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry);
@@ -155,6 +165,7 @@ void ovl_dentry_set_opaque(struct dentry *dentry, bool opaque);
bool ovl_is_whiteout(struct dentry *dentry);
const struct cred *ovl_override_creds(struct super_block *sb);
void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry);
+void ovl_inode_update(struct inode *inode, struct inode *upperinode);
struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags);
struct file *ovl_path_open(struct path *path, int flags);
@@ -183,8 +194,7 @@ struct posix_acl *ovl_get_acl(struct inode *inode, int type);
int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags);
int ovl_update_time(struct inode *inode, struct timespec *ts, int flags);
-struct inode *ovl_new_inode(struct super_block *sb, umode_t mode,
- struct ovl_entry *oe);
+struct inode *ovl_new_inode(struct super_block *sb, umode_t mode);
static inline void ovl_copyattr(struct inode *from, struct inode *to)
{
to->i_uid = from->i_uid;
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 058103c60f54..313f773652ff 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -145,25 +145,11 @@ struct dentry *ovl_dentry_real(struct dentry *dentry)
return realdentry;
}
-struct dentry *ovl_entry_real(struct ovl_entry *oe, bool *is_upper)
+static void ovl_inode_init(struct inode *inode, struct inode *realinode,
+ bool is_upper)
{
- struct dentry *realdentry;
-
- realdentry = ovl_upperdentry_dereference(oe);
- if (realdentry) {
- *is_upper = true;
- } else {
- realdentry = __ovl_dentry_lower(oe);
- *is_upper = false;
- }
- return realdentry;
-}
-
-struct inode *ovl_inode_real(struct inode *inode)
-{
- bool tmp;
-
- return d_inode(ovl_entry_real(inode->i_private, &tmp));
+ WRITE_ONCE(inode->i_private, (unsigned long) realinode |
+ (is_upper ? OVL_ISUPPER_MASK : 0));
}
struct vfsmount *ovl_entry_mnt_real(struct ovl_entry *oe, struct inode *inode,
@@ -235,7 +221,6 @@ void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry)
WARN_ON(!inode_is_locked(upperdentry->d_parent->d_inode));
WARN_ON(oe->__upperdentry);
- BUG_ON(!upperdentry->d_inode);
/*
* Make sure upperdentry is consistent before making it visible to
* ovl_upperdentry_dereference().
@@ -244,6 +229,13 @@ void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry)
oe->__upperdentry = upperdentry;
}
+void ovl_inode_update(struct inode *inode, struct inode *upperinode)
+{
+ WARN_ON(!upperinode);
+ WRITE_ONCE(inode->i_private,
+ (unsigned long) upperinode | OVL_ISUPPER_MASK);
+}
+
void ovl_dentry_version_inc(struct dentry *dentry)
{
struct ovl_entry *oe = dentry->d_fsdata;
@@ -574,14 +566,16 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
if (upperdentry || ctr) {
struct dentry *realdentry;
+ struct inode *realinode;
realdentry = upperdentry ? upperdentry : stack[0].dentry;
+ realinode = d_inode(realdentry);
err = -ENOMEM;
- inode = ovl_new_inode(dentry->d_sb, realdentry->d_inode->i_mode,
- oe);
+ inode = ovl_new_inode(dentry->d_sb, realinode->i_mode);
if (!inode)
goto out_free_oe;
+ ovl_inode_init(inode, realinode, !!upperdentry);
ovl_copyattr(realdentry->d_inode, inode);
}
@@ -969,6 +963,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
struct path upperpath = { NULL, NULL };
struct path workpath = { NULL, NULL };
struct dentry *root_dentry;
+ struct inode *realinode;
struct ovl_entry *oe;
struct ovl_fs *ufs;
struct path *stack = NULL;
@@ -1150,7 +1145,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
if (!oe)
goto out_put_cred;
- root_dentry = d_make_root(ovl_new_inode(sb, S_IFDIR, oe));
+ root_dentry = d_make_root(ovl_new_inode(sb, S_IFDIR));
if (!root_dentry)
goto out_free_oe;
@@ -1169,8 +1164,9 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
root_dentry->d_fsdata = oe;
- ovl_copyattr(ovl_dentry_real(root_dentry)->d_inode,
- root_dentry->d_inode);
+ realinode = d_inode(ovl_dentry_real(root_dentry));
+ ovl_inode_init(d_inode(root_dentry), realinode, !!upperpath.dentry);
+ ovl_copyattr(realinode, d_inode(root_dentry));
sb->s_magic = OVERLAYFS_SUPER_MAGIC;
sb->s_op = &ovl_super_operations;
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.