diff options
Diffstat (limited to 'fs/overlayfs/overlayfs.h')
| -rw-r--r-- | fs/overlayfs/overlayfs.h | 34 |
1 files changed, 28 insertions, 6 deletions
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index 6934bcf030f0..f283b1d69a9e 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -71,20 +71,36 @@ enum ovl_entry_flag { #error Endianness not defined #endif -/* The type returned by overlay exportfs ops when encoding an ovl_fh handle */ -#define OVL_FILEID 0xfb +/* The type used to be returned by overlay exportfs for misaligned fid */ +#define OVL_FILEID_V0 0xfb +/* The type returned by overlay exportfs for 32bit aligned fid */ +#define OVL_FILEID_V1 0xf8 -/* On-disk and in-memeory format for redirect by file handle */ -struct ovl_fh { +/* On-disk format for "origin" file handle */ +struct ovl_fb { 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_t uuid; /* uuid of filesystem */ - u8 fid[0]; /* file identifier */ + u32 fid[0]; /* file identifier should be 32bit aligned in-memory */ } __packed; +/* In-memory and on-wire format for overlay file handle */ +struct ovl_fh { + u8 padding[3]; /* make sure fb.fid is 32bit aligned */ + union { + struct ovl_fb fb; + u8 buf[0]; + }; +} __packed; + +#define OVL_FH_WIRE_OFFSET offsetof(struct ovl_fh, fb) +#define OVL_FH_LEN(fh) (OVL_FH_WIRE_OFFSET + (fh)->fb.len) +#define OVL_FH_FID_OFFSET (OVL_FH_WIRE_OFFSET + \ + offsetof(struct ovl_fb, fid)) + static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry) { int err = vfs_rmdir(dir, dentry); @@ -302,7 +318,13 @@ static inline void ovl_inode_unlock(struct inode *inode) /* namei.c */ -int ovl_check_fh_len(struct ovl_fh *fh, int fh_len); +int ovl_check_fb_len(struct ovl_fb *fb, int fb_len); + +static inline int ovl_check_fh_len(struct ovl_fh *fh, int fh_len) +{ + return ovl_check_fb_len(&fh->fb, fh_len - OVL_FH_WIRE_OFFSET); +} + struct dentry *ovl_decode_real_fh(struct ovl_fh *fh, struct vfsmount *mnt, bool connected); int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected, |