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-rw-r--r--fs/overlayfs/overlayfs.h41
1 files changed, 41 insertions, 0 deletions
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 741dc0b6931f..caa36cb9c46d 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -8,18 +8,56 @@
*/
#include <linux/kernel.h>
+#include <linux/uuid.h>
enum ovl_path_type {
__OVL_PATH_UPPER = (1 << 0),
__OVL_PATH_MERGE = (1 << 1),
+ __OVL_PATH_ORIGIN = (1 << 2),
};
#define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER)
#define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE)
+#define OVL_TYPE_ORIGIN(type) ((type) & __OVL_PATH_ORIGIN)
#define OVL_XATTR_PREFIX XATTR_TRUSTED_PREFIX "overlay."
#define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX "opaque"
#define OVL_XATTR_REDIRECT OVL_XATTR_PREFIX "redirect"
+#define OVL_XATTR_ORIGIN OVL_XATTR_PREFIX "origin"
+
+/*
+ * The tuple (fh,uuid) is a universal unique identifier for a copy up origin,
+ * where:
+ * origin.fh - exported file handle of the lower file
+ * origin.uuid - uuid of the lower filesystem
+ */
+#define OVL_FH_VERSION 0
+#define OVL_FH_MAGIC 0xfb
+
+/* CPU byte order required for fid decoding: */
+#define OVL_FH_FLAG_BIG_ENDIAN (1 << 0)
+#define OVL_FH_FLAG_ANY_ENDIAN (1 << 1)
+
+#define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN)
+
+#if defined(__LITTLE_ENDIAN)
+#define OVL_FH_FLAG_CPU_ENDIAN 0
+#elif defined(__BIG_ENDIAN)
+#define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN
+#else
+#error Endianness not defined
+#endif
+
+/* On-disk and in-memeory format for redirect by file handle */
+struct ovl_fh {
+ u8 version; /* 0 */
+ u8 magic; /* 0xfb */
+ u8 len; /* size of this header + size of fid */
+ u8 flags; /* OVL_FH_FLAG_* */
+ u8 type; /* fid_type of fid */
+ uuid_be uuid; /* uuid of filesystem */
+ u8 fid[0]; /* file identifier */
+} __packed;
#define OVL_ISUPPER_MASK 1UL
@@ -151,6 +189,7 @@ int ovl_want_write(struct dentry *dentry);
void ovl_drop_write(struct dentry *dentry);
struct dentry *ovl_workdir(struct dentry *dentry);
const struct cred *ovl_override_creds(struct super_block *sb);
+struct super_block *ovl_same_sb(struct super_block *sb);
struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
bool ovl_dentry_remote(struct dentry *dentry);
bool ovl_dentry_weird(struct dentry *dentry);
@@ -197,6 +236,8 @@ void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
/* inode.c */
int ovl_setattr(struct dentry *dentry, struct iattr *attr);
+int ovl_getattr(const struct path *path, struct kstat *stat,
+ u32 request_mask, unsigned int flags);
int ovl_permission(struct inode *inode, int mask);
int ovl_xattr_set(struct dentry *dentry, const char *name, const void *value,
size_t size, int flags);