diff options
Diffstat (limited to 'fs/overlayfs/overlayfs.h')
| -rw-r--r-- | fs/overlayfs/overlayfs.h | 41 |
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); |