diff options
| author | Amir Goldstein <amir73il@gmail.com> | 2017-06-21 15:28:38 +0300 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2017-07-04 22:03:17 +0200 |
| commit | 54fb347e836faadaed2a5617fb4dd4a4597d0490 (patch) | |
| tree | 776d77e3848edf181ebeeda5bea8169c8937c6bc /fs/overlayfs/overlayfs.h | |
| parent | 8b88a2e6403638b56556ed5b1c60d9318eefea9c (diff) | |
| download | linux-54fb347e836faadaed2a5617fb4dd4a4597d0490.tar.bz2 | |
ovl: verify index dir matches upper dir
An index dir contains persistent hardlinks to files in upper dir.
Therefore, we must never mount an existing index dir with a differnt
upper dir.
Store the upper root dir file handle in index dir inode when index
dir is created and verify the file handle before using an existing
index dir on mount.
Add an 'is_upper' flag to the overlay file handle encoding and set it
when encoding the upper root file handle. This is not critical for index
dir verification, but it is good practice towards a standard overlayfs
file handle format for NFS export.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/overlayfs/overlayfs.h')
| -rw-r--r-- | fs/overlayfs/overlayfs.h | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index 38ac84cba6ea..58bbd135a7b3 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -42,6 +42,8 @@ enum ovl_flag { /* CPU byte order required for fid decoding: */ #define OVL_FH_FLAG_BIG_ENDIAN (1 << 0) #define OVL_FH_FLAG_ANY_ENDIAN (1 << 1) +/* Is the real inode encoded in fid an upper inode? */ +#define OVL_FH_FLAG_PATH_UPPER (1 << 2) #define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN) @@ -233,7 +235,7 @@ static inline bool ovl_is_impuredir(struct dentry *dentry) /* namei.c */ int ovl_verify_origin(struct dentry *dentry, struct vfsmount *mnt, - struct dentry *origin, bool set); + struct dentry *origin, bool is_upper, bool set); int ovl_path_next(int idx, struct dentry *dentry, struct path *path); struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags); bool ovl_lower_positive(struct dentry *dentry); @@ -292,4 +294,4 @@ int ovl_copy_up(struct dentry *dentry); int ovl_copy_up_flags(struct dentry *dentry, int flags); int ovl_copy_xattr(struct dentry *old, struct dentry *new); int ovl_set_attr(struct dentry *upper, struct kstat *stat); -struct ovl_fh *ovl_encode_fh(struct dentry *lower); +struct ovl_fh *ovl_encode_fh(struct dentry *lower, bool is_upper); |