[PATCH v3 02/16] ovl: cram opaque boolean into type flags

Amir Goldstein
2017-04-26T21:35:18Z

We are going to add more state info to ovl_entry soon (for const ino)
and this state info would be added as type flags.

It makes sense to treat 'opaque' in a similar way, so instead of using
a boolean member in ovl_entry use a type bit to represent opaqueness.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
---
fs/overlayfs/namei.c | 9 +++++----
fs/overlayfs/overlayfs.h | 2 ++
fs/overlayfs/ovl_entry.h | 1 -
fs/overlayfs/util.c | 5 +++--
4 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index 8788fd7..d660177 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -224,7 +224,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
struct dentry *upperdir, *upperdentry = NULL;
unsigned int ctr = 0;
struct inode *inode = NULL;
- bool upperopaque = false;
+ enum ovl_path_type type = 0;
char *upperredirect = NULL;
struct dentry *this;
unsigned int i;
@@ -261,7 +261,8 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
if (d.redirect[0] == '/')
poe = dentry->d_sb->s_root->d_fsdata;
}
- upperopaque = d.opaque;
+ if (d.opaque)
+ type |= __OVL_PATH_OPAQUE;
}

if (!d.stop && poe->numlower) {
@@ -331,7 +332,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
}

revert_creds(old_cred);
- oe->opaque = upperopaque;
+ oe->__type = type;
oe->redirect = upperredirect;
oe->__upperdentry = upperdentry;
memcpy(oe->lowerstack, stack, sizeof(struct path) * ctr);
@@ -372,7 +373,7 @@ bool ovl_lower_positive(struct dentry *dentry)
* whiteout.
*/
if (!dentry->d_inode)
- return oe->opaque;
+ return OVL_TYPE_OPAQUE(oe->__type);

/* Negative upper -> positive lower */
if (!oe->__upperdentry)
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index e90a548..9420101 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -12,10 +12,12 @@
enum ovl_path_type {
__OVL_PATH_UPPER = (1 << 0),
__OVL_PATH_MERGE = (1 << 1),
+ __OVL_PATH_OPAQUE = (1 << 2),
};

#define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER)
#define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE)
+#define OVL_TYPE_OPAQUE(type) ((type) & __OVL_PATH_OPAQUE)

#define OVL_XATTR_PREFIX XATTR_TRUSTED_PREFIX "overlay."
#define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX "opaque"
diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h
index 293be5f..12c4922 100644
--- a/fs/overlayfs/ovl_entry.h
+++ b/fs/overlayfs/ovl_entry.h
@@ -41,7 +41,6 @@ struct ovl_entry {
struct {
u64 version;
const char *redirect;
- bool opaque;
bool copying;
};
struct rcu_head rcu;
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index bbd6074..88cfc2a 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -181,7 +181,8 @@ void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache)
bool ovl_dentry_is_opaque(struct dentry *dentry)
{
struct ovl_entry *oe = dentry->d_fsdata;
- return oe->opaque;
+
+ return OVL_TYPE_OPAQUE(oe->__type);
}

bool ovl_dentry_is_whiteout(struct dentry *dentry)
@@ -193,7 +194,7 @@ void ovl_dentry_set_opaque(struct dentry *dentry)
{
struct ovl_entry *oe = dentry->d_fsdata;

- oe->opaque = true;
+ oe->__type |= __OVL_PATH_OPAQUE;
}

bool ovl_redirect_dir(struct super_block *sb)
--
2.7.4