diff options
Diffstat (limited to 'fs/overlayfs/overlayfs.h')
| -rw-r--r-- | fs/overlayfs/overlayfs.h | 122 |
1 files changed, 104 insertions, 18 deletions
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index 8af450b0e57a..e927a62c97ae 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -8,20 +8,66 @@ */ #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" +#define OVL_XATTR_IMPURE OVL_XATTR_PREFIX "impure" +#define OVL_XATTR_NLINK OVL_XATTR_PREFIX "nlink" -#define OVL_ISUPPER_MASK 1UL +enum ovl_flag { + OVL_IMPURE, + OVL_INDEX, +}; + +/* + * 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) +/* 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 | \ + OVL_FH_FLAG_PATH_UPPER) + +#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_t uuid; /* uuid of filesystem */ + u8 fid[0]; /* file identifier */ +} __packed; static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry) { @@ -127,14 +173,13 @@ static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry) return err; } -static inline struct inode *ovl_inode_real(struct inode *inode, bool *is_upper) +static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode) { - unsigned long x = (unsigned long) READ_ONCE(inode->i_private); - - if (is_upper) - *is_upper = x & OVL_ISUPPER_MASK; + struct dentry *ret = vfs_tmpfile(dentry, mode, 0); + int err = IS_ERR(ret) ? PTR_ERR(ret) : 0; - return (struct inode *) (x & ~OVL_ISUPPER_MASK); + pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err); + return ret; } /* util.c */ @@ -142,6 +187,9 @@ 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); +bool ovl_can_decode_fh(struct super_block *sb); +struct dentry *ovl_indexdir(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); @@ -152,25 +200,53 @@ enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); struct dentry *ovl_dentry_upper(struct dentry *dentry); struct dentry *ovl_dentry_lower(struct dentry *dentry); struct dentry *ovl_dentry_real(struct dentry *dentry); +struct dentry *ovl_i_dentry_upper(struct inode *inode); +struct inode *ovl_inode_upper(struct inode *inode); +struct inode *ovl_inode_lower(struct inode *inode); +struct inode *ovl_inode_real(struct inode *inode); struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry); void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache); bool ovl_dentry_is_opaque(struct dentry *dentry); bool ovl_dentry_is_whiteout(struct dentry *dentry); void ovl_dentry_set_opaque(struct dentry *dentry); +bool ovl_dentry_has_upper_alias(struct dentry *dentry); +void ovl_dentry_set_upper_alias(struct dentry *dentry); bool ovl_redirect_dir(struct super_block *sb); -void ovl_clear_redirect_dir(struct super_block *sb); const char *ovl_dentry_get_redirect(struct dentry *dentry); void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect); -void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry); -void ovl_inode_init(struct inode *inode, struct inode *realinode, - bool is_upper); -void ovl_inode_update(struct inode *inode, struct inode *upperinode); +void ovl_inode_init(struct inode *inode, struct dentry *upperdentry, + struct dentry *lowerdentry); +void ovl_inode_update(struct inode *inode, struct dentry *upperdentry); void ovl_dentry_version_inc(struct dentry *dentry); u64 ovl_dentry_version_get(struct dentry *dentry); bool ovl_is_whiteout(struct dentry *dentry); struct file *ovl_path_open(struct path *path, int flags); +int ovl_copy_up_start(struct dentry *dentry); +void ovl_copy_up_end(struct dentry *dentry); +bool ovl_check_dir_xattr(struct dentry *dentry, const char *name); +int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry, + const char *name, const void *value, size_t size, + int xerr); +int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry); +void ovl_set_flag(unsigned long flag, struct inode *inode); +bool ovl_test_flag(unsigned long flag, struct inode *inode); +bool ovl_inuse_trylock(struct dentry *dentry); +void ovl_inuse_unlock(struct dentry *dentry); +int ovl_nlink_start(struct dentry *dentry, bool *locked); +void ovl_nlink_end(struct dentry *dentry, bool locked); + +static inline bool ovl_is_impuredir(struct dentry *dentry) +{ + return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE); +} + /* namei.c */ +int ovl_verify_origin(struct dentry *dentry, struct vfsmount *mnt, + struct dentry *origin, bool is_upper, bool set); +int ovl_verify_index(struct dentry *index, struct path *lowerstack, + unsigned int numlower); +int ovl_get_index_name(struct dentry *origin, struct qstr *name); 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); @@ -183,13 +259,22 @@ void ovl_cache_free(struct list_head *list); int ovl_check_d_type_supported(struct path *realpath); void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt, struct dentry *dentry, int level); +int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt, + struct path *lowerstack, unsigned int numlower); /* inode.c */ +int ovl_set_nlink_upper(struct dentry *dentry); +int ovl_set_nlink_lower(struct dentry *dentry); +unsigned int ovl_get_nlink(struct dentry *lowerdentry, + struct dentry *upperdentry, + unsigned int fallback); 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); -int ovl_xattr_get(struct dentry *dentry, const char *name, +int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name, + const void *value, size_t size, int flags); +int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name, void *value, size_t size); ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size); struct posix_acl *ovl_get_acl(struct inode *inode, int type); @@ -198,7 +283,7 @@ int ovl_update_time(struct inode *inode, struct timespec *ts, int flags); bool ovl_is_private_xattr(const char *name); struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev); -struct inode *ovl_get_inode(struct super_block *sb, struct inode *realinode); +struct inode *ovl_get_inode(struct dentry *dentry, struct dentry *upperdentry); static inline void ovl_copyattr(struct inode *from, struct inode *to) { to->i_uid = from->i_uid; @@ -211,7 +296,7 @@ static inline void ovl_copyattr(struct inode *from, struct inode *to) /* dir.c */ extern const struct inode_operations ovl_dir_inode_operations; -struct dentry *ovl_lookup_temp(struct dentry *workdir, struct dentry *dentry); +struct dentry *ovl_lookup_temp(struct dentry *workdir); struct cattr { dev_t rdev; umode_t mode; @@ -220,10 +305,11 @@ struct cattr { int ovl_create_real(struct inode *dir, struct dentry *newdentry, struct cattr *attr, struct dentry *hardlink, bool debug); -void ovl_cleanup(struct inode *dir, struct dentry *dentry); +int ovl_cleanup(struct inode *dir, struct dentry *dentry); /* copy_up.c */ 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, bool is_upper); |