| /* SPDX-License-Identifier: GPL-2.0-only */ |
| /* |
| * |
| * Copyright (C) 2011 Novell Inc. |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/uuid.h> |
| #include <linux/fs.h> |
| #include <linux/fsverity.h> |
| #include <linux/namei.h> |
| #include <linux/posix_acl.h> |
| #include <linux/posix_acl_xattr.h> |
| #include "ovl_entry.h" |
| |
| #undef pr_fmt |
| #define pr_fmt(fmt) "overlayfs: " fmt |
| |
| 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_NAMESPACE "overlay." |
| #define OVL_XATTR_TRUSTED_PREFIX XATTR_TRUSTED_PREFIX OVL_XATTR_NAMESPACE |
| #define OVL_XATTR_TRUSTED_PREFIX_LEN (sizeof(OVL_XATTR_TRUSTED_PREFIX) - 1) |
| #define OVL_XATTR_USER_PREFIX XATTR_USER_PREFIX OVL_XATTR_NAMESPACE |
| #define OVL_XATTR_USER_PREFIX_LEN (sizeof(OVL_XATTR_USER_PREFIX) - 1) |
| |
| #define OVL_XATTR_ESCAPE_PREFIX OVL_XATTR_NAMESPACE |
| #define OVL_XATTR_ESCAPE_PREFIX_LEN (sizeof(OVL_XATTR_ESCAPE_PREFIX) - 1) |
| #define OVL_XATTR_ESCAPE_TRUSTED_PREFIX OVL_XATTR_TRUSTED_PREFIX OVL_XATTR_ESCAPE_PREFIX |
| #define OVL_XATTR_ESCAPE_TRUSTED_PREFIX_LEN (sizeof(OVL_XATTR_ESCAPE_TRUSTED_PREFIX) - 1) |
| #define OVL_XATTR_ESCAPE_USER_PREFIX OVL_XATTR_USER_PREFIX OVL_XATTR_ESCAPE_PREFIX |
| #define OVL_XATTR_ESCAPE_USER_PREFIX_LEN (sizeof(OVL_XATTR_ESCAPE_USER_PREFIX) - 1) |
| |
| enum ovl_xattr { |
| OVL_XATTR_OPAQUE, |
| OVL_XATTR_REDIRECT, |
| OVL_XATTR_ORIGIN, |
| OVL_XATTR_IMPURE, |
| OVL_XATTR_NLINK, |
| OVL_XATTR_UPPER, |
| OVL_XATTR_UUID, |
| OVL_XATTR_METACOPY, |
| OVL_XATTR_PROTATTR, |
| OVL_XATTR_XWHITEOUT, |
| OVL_XATTR_XWHITEOUTS, |
| }; |
| |
| enum ovl_inode_flag { |
| /* Pure upper dir that may contain non pure upper entries */ |
| OVL_IMPURE, |
| /* Non-merge dir that may contain whiteout entries */ |
| OVL_WHITEOUTS, |
| OVL_INDEX, |
| OVL_UPPERDATA, |
| /* Inode number will remain constant over copy up. */ |
| OVL_CONST_INO, |
| OVL_HAS_DIGEST, |
| OVL_VERIFIED_DIGEST, |
| }; |
| |
| enum ovl_entry_flag { |
| OVL_E_UPPER_ALIAS, |
| OVL_E_OPAQUE, |
| OVL_E_CONNECTED, |
| }; |
| |
| enum { |
| OVL_REDIRECT_OFF, /* "off" mode is never used. In effect */ |
| OVL_REDIRECT_FOLLOW, /* ...it translates to either "follow" */ |
| OVL_REDIRECT_NOFOLLOW, /* ...or "nofollow". */ |
| OVL_REDIRECT_ON, |
| }; |
| |
| enum { |
| OVL_UUID_OFF, |
| OVL_UUID_NULL, |
| OVL_UUID_AUTO, |
| OVL_UUID_ON, |
| }; |
| |
| enum { |
| OVL_XINO_OFF, |
| OVL_XINO_AUTO, |
| OVL_XINO_ON, |
| }; |
| |
| enum { |
| OVL_VERITY_OFF, |
| OVL_VERITY_ON, |
| OVL_VERITY_REQUIRE, |
| }; |
| |
| /* |
| * 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 |
| |
| /* 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 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 */ |
| u32 fid[]; /* 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; |
| DECLARE_FLEX_ARRAY(u8, buf); |
| }; |
| } __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)) |
| |
| /* On-disk format for "metacopy" xattr (if non-zero size) */ |
| struct ovl_metacopy { |
| u8 version; /* 0 */ |
| u8 len; /* size of this header + used digest bytes */ |
| u8 flags; |
| u8 digest_algo; /* FS_VERITY_HASH_ALG_* constant, 0 for no digest */ |
| u8 digest[FS_VERITY_MAX_DIGEST_SIZE]; /* Only the used part on disk */ |
| } __packed; |
| |
| #define OVL_METACOPY_MAX_SIZE (sizeof(struct ovl_metacopy)) |
| #define OVL_METACOPY_MIN_SIZE (OVL_METACOPY_MAX_SIZE - FS_VERITY_MAX_DIGEST_SIZE) |
| #define OVL_METACOPY_INIT { 0, OVL_METACOPY_MIN_SIZE } |
| |
| static inline int ovl_metadata_digest_size(const struct ovl_metacopy *metacopy) |
| { |
| if (metacopy->len < OVL_METACOPY_MIN_SIZE) |
| return 0; |
| return (int)metacopy->len - OVL_METACOPY_MIN_SIZE; |
| } |
| |
| extern const char *const ovl_xattr_table[][2]; |
| static inline const char *ovl_xattr(struct ovl_fs *ofs, enum ovl_xattr ox) |
| { |
| return ovl_xattr_table[ox][ofs->config.userxattr]; |
| } |
| |
| /* |
| * When changing ownership of an upper object map the intended ownership |
| * according to the upper layer's idmapping. When an upper mount idmaps files |
| * that are stored on-disk as owned by id 1001 to id 1000 this means stat on |
| * this object will report it as being owned by id 1000 when calling stat via |
| * the upper mount. |
| * In order to change ownership of an object so stat reports id 1000 when |
| * called on an idmapped upper mount the value written to disk - i.e., the |
| * value stored in ia_*id - must 1001. The mount mapping helper will thus take |
| * care to map 1000 to 1001. |
| * The mnt idmapping helpers are nops if the upper layer isn't idmapped. |
| */ |
| static inline int ovl_do_notify_change(struct ovl_fs *ofs, |
| struct dentry *upperdentry, |
| struct iattr *attr) |
| { |
| return notify_change(ovl_upper_mnt_idmap(ofs), upperdentry, attr, NULL); |
| } |
| |
| static inline int ovl_do_rmdir(struct ovl_fs *ofs, |
| struct inode *dir, struct dentry *dentry) |
| { |
| int err = vfs_rmdir(ovl_upper_mnt_idmap(ofs), dir, dentry); |
| |
| pr_debug("rmdir(%pd2) = %i\n", dentry, err); |
| return err; |
| } |
| |
| static inline int ovl_do_unlink(struct ovl_fs *ofs, struct inode *dir, |
| struct dentry *dentry) |
| { |
| int err = vfs_unlink(ovl_upper_mnt_idmap(ofs), dir, dentry, NULL); |
| |
| pr_debug("unlink(%pd2) = %i\n", dentry, err); |
| return err; |
| } |
| |
| static inline int ovl_do_link(struct ovl_fs *ofs, struct dentry *old_dentry, |
| struct inode *dir, struct dentry *new_dentry) |
| { |
| int err = vfs_link(old_dentry, ovl_upper_mnt_idmap(ofs), dir, |
| new_dentry, NULL); |
| |
| pr_debug("link(%pd2, %pd2) = %i\n", old_dentry, new_dentry, err); |
| return err; |
| } |
| |
| static inline int ovl_do_create(struct ovl_fs *ofs, |
| struct inode *dir, struct dentry *dentry, |
| umode_t mode) |
| { |
| int err = vfs_create(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, true); |
| |
| pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err); |
| return err; |
| } |
| |
| static inline int ovl_do_mkdir(struct ovl_fs *ofs, |
| struct inode *dir, struct dentry *dentry, |
| umode_t mode) |
| { |
| int err = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode); |
| pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err); |
| return err; |
| } |
| |
| static inline int ovl_do_mknod(struct ovl_fs *ofs, |
| struct inode *dir, struct dentry *dentry, |
| umode_t mode, dev_t dev) |
| { |
| int err = vfs_mknod(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, dev); |
| |
| pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err); |
| return err; |
| } |
| |
| static inline int ovl_do_symlink(struct ovl_fs *ofs, |
| struct inode *dir, struct dentry *dentry, |
| const char *oldname) |
| { |
| int err = vfs_symlink(ovl_upper_mnt_idmap(ofs), dir, dentry, oldname); |
| |
| pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err); |
| return err; |
| } |
| |
| static inline ssize_t ovl_do_getxattr(const struct path *path, const char *name, |
| void *value, size_t size) |
| { |
| int err, len; |
| |
| WARN_ON(path->dentry->d_sb != path->mnt->mnt_sb); |
| |
| err = vfs_getxattr(mnt_idmap(path->mnt), path->dentry, |
| name, value, size); |
| len = (value && err > 0) ? err : 0; |
| |
| pr_debug("getxattr(%pd2, \"%s\", \"%*pE\", %zu, 0) = %i\n", |
| path->dentry, name, min(len, 48), value, size, err); |
| return err; |
| } |
| |
| static inline ssize_t ovl_getxattr_upper(struct ovl_fs *ofs, |
| struct dentry *upperdentry, |
| enum ovl_xattr ox, void *value, |
| size_t size) |
| { |
| struct path upperpath = { |
| .dentry = upperdentry, |
| .mnt = ovl_upper_mnt(ofs), |
| }; |
| |
| return ovl_do_getxattr(&upperpath, ovl_xattr(ofs, ox), value, size); |
| } |
| |
| static inline ssize_t ovl_path_getxattr(struct ovl_fs *ofs, |
| const struct path *path, |
| enum ovl_xattr ox, void *value, |
| size_t size) |
| { |
| return ovl_do_getxattr(path, ovl_xattr(ofs, ox), value, size); |
| } |
| |
| static inline int ovl_do_setxattr(struct ovl_fs *ofs, struct dentry *dentry, |
| const char *name, const void *value, |
| size_t size, int flags) |
| { |
| int err = vfs_setxattr(ovl_upper_mnt_idmap(ofs), dentry, name, |
| value, size, flags); |
| |
| pr_debug("setxattr(%pd2, \"%s\", \"%*pE\", %zu, %d) = %i\n", |
| dentry, name, min((int)size, 48), value, size, flags, err); |
| return err; |
| } |
| |
| static inline int ovl_setxattr(struct ovl_fs *ofs, struct dentry *dentry, |
| enum ovl_xattr ox, const void *value, |
| size_t size) |
| { |
| return ovl_do_setxattr(ofs, dentry, ovl_xattr(ofs, ox), value, size, 0); |
| } |
| |
| static inline int ovl_do_removexattr(struct ovl_fs *ofs, struct dentry *dentry, |
| const char *name) |
| { |
| int err = vfs_removexattr(ovl_upper_mnt_idmap(ofs), dentry, name); |
| pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err); |
| return err; |
| } |
| |
| static inline int ovl_removexattr(struct ovl_fs *ofs, struct dentry *dentry, |
| enum ovl_xattr ox) |
| { |
| return ovl_do_removexattr(ofs, dentry, ovl_xattr(ofs, ox)); |
| } |
| |
| static inline int ovl_do_set_acl(struct ovl_fs *ofs, struct dentry *dentry, |
| const char *acl_name, struct posix_acl *acl) |
| { |
| return vfs_set_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name, acl); |
| } |
| |
| static inline int ovl_do_remove_acl(struct ovl_fs *ofs, struct dentry *dentry, |
| const char *acl_name) |
| { |
| return vfs_remove_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name); |
| } |
| |
| static inline int ovl_do_rename(struct ovl_fs *ofs, struct inode *olddir, |
| struct dentry *olddentry, struct inode *newdir, |
| struct dentry *newdentry, unsigned int flags) |
| { |
| int err; |
| struct renamedata rd = { |
| .old_mnt_idmap = ovl_upper_mnt_idmap(ofs), |
| .old_dir = olddir, |
| .old_dentry = olddentry, |
| .new_mnt_idmap = ovl_upper_mnt_idmap(ofs), |
| .new_dir = newdir, |
| .new_dentry = newdentry, |
| .flags = flags, |
| }; |
| |
| pr_debug("rename(%pd2, %pd2, 0x%x)\n", olddentry, newdentry, flags); |
| err = vfs_rename(&rd); |
| if (err) { |
| pr_debug("...rename(%pd2, %pd2, ...) = %i\n", |
| olddentry, newdentry, err); |
| } |
| return err; |
| } |
| |
| static inline int ovl_do_whiteout(struct ovl_fs *ofs, |
| struct inode *dir, struct dentry *dentry) |
| { |
| int err = vfs_whiteout(ovl_upper_mnt_idmap(ofs), dir, dentry); |
| pr_debug("whiteout(%pd2) = %i\n", dentry, err); |
| return err; |
| } |
| |
| static inline struct file *ovl_do_tmpfile(struct ovl_fs *ofs, |
| struct dentry *dentry, umode_t mode) |
| { |
| struct path path = { .mnt = ovl_upper_mnt(ofs), .dentry = dentry }; |
| struct file *file = kernel_tmpfile_open(ovl_upper_mnt_idmap(ofs), &path, |
| mode, O_LARGEFILE | O_WRONLY, |
| current_cred()); |
| int err = PTR_ERR_OR_ZERO(file); |
| |
| pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err); |
| return file; |
| } |
| |
| static inline struct dentry *ovl_lookup_upper(struct ovl_fs *ofs, |
| const char *name, |
| struct dentry *base, int len) |
| { |
| return lookup_one(ovl_upper_mnt_idmap(ofs), name, base, len); |
| } |
| |
| static inline bool ovl_open_flags_need_copy_up(int flags) |
| { |
| if (!flags) |
| return false; |
| |
| return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC)); |
| } |
| |
| static inline int ovl_do_getattr(const struct path *path, struct kstat *stat, |
| u32 request_mask, unsigned int flags) |
| { |
| if (flags & AT_GETATTR_NOSEC) |
| return vfs_getattr_nosec(path, stat, request_mask, flags); |
| return vfs_getattr(path, stat, request_mask, flags); |
| } |
| |
| /* util.c */ |
| int ovl_get_write_access(struct dentry *dentry); |
| void ovl_put_write_access(struct dentry *dentry); |
| void ovl_start_write(struct dentry *dentry); |
| void ovl_end_write(struct dentry *dentry); |
| 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); |
| int ovl_can_decode_fh(struct super_block *sb); |
| struct dentry *ovl_indexdir(struct super_block *sb); |
| bool ovl_index_all(struct super_block *sb); |
| bool ovl_verify_lower(struct super_block *sb); |
| struct ovl_path *ovl_stack_alloc(unsigned int n); |
| void ovl_stack_cpy(struct ovl_path *dst, struct ovl_path *src, unsigned int n); |
| void ovl_stack_put(struct ovl_path *stack, unsigned int n); |
| void ovl_stack_free(struct ovl_path *stack, unsigned int n); |
| struct ovl_entry *ovl_alloc_entry(unsigned int numlower); |
| void ovl_free_entry(struct ovl_entry *oe); |
| bool ovl_dentry_remote(struct dentry *dentry); |
| void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *realdentry); |
| void ovl_dentry_init_reval(struct dentry *dentry, struct dentry *upperdentry, |
| struct ovl_entry *oe); |
| void ovl_dentry_init_flags(struct dentry *dentry, struct dentry *upperdentry, |
| struct ovl_entry *oe, unsigned int mask); |
| bool ovl_dentry_weird(struct dentry *dentry); |
| enum ovl_path_type ovl_path_type(struct dentry *dentry); |
| void ovl_path_upper(struct dentry *dentry, struct path *path); |
| void ovl_path_lower(struct dentry *dentry, struct path *path); |
| void ovl_path_lowerdata(struct dentry *dentry, struct path *path); |
| struct inode *ovl_i_path_real(struct inode *inode, struct path *path); |
| enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); |
| enum ovl_path_type ovl_path_realdata(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_lowerdata(struct dentry *dentry); |
| int ovl_dentry_set_lowerdata(struct dentry *dentry, struct ovl_path *datapath); |
| const struct ovl_layer *ovl_i_layer_lower(struct inode *inode); |
| const struct ovl_layer *ovl_layer_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_lowerdata(struct inode *inode); |
| struct inode *ovl_inode_real(struct inode *inode); |
| struct inode *ovl_inode_realdata(struct inode *inode); |
| const char *ovl_lowerdata_redirect(struct inode *inode); |
| struct ovl_dir_cache *ovl_dir_cache(struct inode *inode); |
| void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache); |
| void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry); |
| void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry); |
| bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry); |
| 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_dentry_needs_data_copy_up(struct dentry *dentry, int flags); |
| bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags); |
| bool ovl_has_upperdata(struct inode *inode); |
| void ovl_set_upperdata(struct inode *inode); |
| const char *ovl_dentry_get_redirect(struct dentry *dentry); |
| void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect); |
| void ovl_inode_update(struct inode *inode, struct dentry *upperdentry); |
| void ovl_dir_modified(struct dentry *dentry, bool impurity); |
| u64 ovl_inode_version_get(struct inode *inode); |
| bool ovl_is_whiteout(struct dentry *dentry); |
| bool ovl_path_is_whiteout(struct ovl_fs *ofs, const struct path *path); |
| struct file *ovl_path_open(const struct path *path, int flags); |
| int ovl_copy_up_start(struct dentry *dentry, int flags); |
| void ovl_copy_up_end(struct dentry *dentry); |
| bool ovl_already_copied_up(struct dentry *dentry, int flags); |
| bool ovl_path_check_dir_xattr(struct ovl_fs *ofs, const struct path *path, |
| enum ovl_xattr ox); |
| bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path); |
| bool ovl_path_check_xwhiteout_xattr(struct ovl_fs *ofs, const struct path *path); |
| bool ovl_path_check_xwhiteouts_xattr(struct ovl_fs *ofs, const struct path *path); |
| bool ovl_init_uuid_xattr(struct super_block *sb, struct ovl_fs *ofs, |
| const struct path *upperpath); |
| |
| static inline bool ovl_upper_is_whiteout(struct ovl_fs *ofs, |
| struct dentry *upperdentry) |
| { |
| struct path upperpath = { |
| .dentry = upperdentry, |
| .mnt = ovl_upper_mnt(ofs), |
| }; |
| return ovl_path_is_whiteout(ofs, &upperpath); |
| } |
| |
| static inline bool ovl_check_origin_xattr(struct ovl_fs *ofs, |
| struct dentry *upperdentry) |
| { |
| struct path upperpath = { |
| .dentry = upperdentry, |
| .mnt = ovl_upper_mnt(ofs), |
| }; |
| return ovl_path_check_origin_xattr(ofs, &upperpath); |
| } |
| |
| int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry, |
| enum ovl_xattr ox, const void *value, size_t size, |
| int xerr); |
| int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry); |
| bool ovl_inuse_trylock(struct dentry *dentry); |
| void ovl_inuse_unlock(struct dentry *dentry); |
| bool ovl_is_inuse(struct dentry *dentry); |
| bool ovl_need_index(struct dentry *dentry); |
| int ovl_nlink_start(struct dentry *dentry); |
| void ovl_nlink_end(struct dentry *dentry); |
| int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir); |
| int ovl_check_metacopy_xattr(struct ovl_fs *ofs, const struct path *path, |
| struct ovl_metacopy *data); |
| int ovl_set_metacopy_xattr(struct ovl_fs *ofs, struct dentry *d, |
| struct ovl_metacopy *metacopy); |
| bool ovl_is_metacopy_dentry(struct dentry *dentry); |
| char *ovl_get_redirect_xattr(struct ovl_fs *ofs, const struct path *path, int padding); |
| int ovl_ensure_verity_loaded(struct path *path); |
| int ovl_get_verity_xattr(struct ovl_fs *ofs, const struct path *path, |
| u8 *digest_buf, int *buf_length); |
| int ovl_validate_verity(struct ovl_fs *ofs, |
| struct path *metapath, |
| struct path *datapath); |
| int ovl_get_verity_digest(struct ovl_fs *ofs, struct path *src, |
| struct ovl_metacopy *metacopy); |
| int ovl_sync_status(struct ovl_fs *ofs); |
| |
| static inline void ovl_set_flag(unsigned long flag, struct inode *inode) |
| { |
| set_bit(flag, &OVL_I(inode)->flags); |
| } |
| |
| static inline void ovl_clear_flag(unsigned long flag, struct inode *inode) |
| { |
| clear_bit(flag, &OVL_I(inode)->flags); |
| } |
| |
| static inline bool ovl_test_flag(unsigned long flag, struct inode *inode) |
| { |
| return test_bit(flag, &OVL_I(inode)->flags); |
| } |
| |
| static inline bool ovl_is_impuredir(struct super_block *sb, |
| struct dentry *upperdentry) |
| { |
| struct ovl_fs *ofs = OVL_FS(sb); |
| struct path upperpath = { |
| .dentry = upperdentry, |
| .mnt = ovl_upper_mnt(ofs), |
| }; |
| |
| return ovl_path_check_dir_xattr(ofs, &upperpath, OVL_XATTR_IMPURE); |
| } |
| |
| static inline bool ovl_redirect_follow(struct ovl_fs *ofs) |
| { |
| return ofs->config.redirect_mode != OVL_REDIRECT_NOFOLLOW; |
| } |
| |
| static inline bool ovl_redirect_dir(struct ovl_fs *ofs) |
| { |
| return ofs->config.redirect_mode == OVL_REDIRECT_ON; |
| } |
| |
| static inline bool ovl_origin_uuid(struct ovl_fs *ofs) |
| { |
| return ofs->config.uuid != OVL_UUID_OFF; |
| } |
| |
| static inline bool ovl_has_fsid(struct ovl_fs *ofs) |
| { |
| return ofs->config.uuid == OVL_UUID_ON || |
| ofs->config.uuid == OVL_UUID_AUTO; |
| } |
| |
| /* |
| * With xino=auto, we do best effort to keep all inodes on same st_dev and |
| * d_ino consistent with st_ino. |
| * With xino=on, we do the same effort but we warn if we failed. |
| */ |
| static inline bool ovl_xino_warn(struct ovl_fs *ofs) |
| { |
| return ofs->config.xino == OVL_XINO_ON; |
| } |
| |
| /* |
| * To avoid regressions in existing setups with overlay lower offline changes, |
| * we allow lower changes only if none of the new features are used. |
| */ |
| static inline bool ovl_allow_offline_changes(struct ovl_fs *ofs) |
| { |
| return (!ofs->config.index && !ofs->config.metacopy && |
| !ovl_redirect_dir(ofs) && !ovl_xino_warn(ofs)); |
| } |
| |
| /* All layers on same fs? */ |
| static inline bool ovl_same_fs(struct ovl_fs *ofs) |
| { |
| return ofs->xino_mode == 0; |
| } |
| |
| /* All overlay inodes have same st_dev? */ |
| static inline bool ovl_same_dev(struct ovl_fs *ofs) |
| { |
| return ofs->xino_mode >= 0; |
| } |
| |
| static inline unsigned int ovl_xino_bits(struct ovl_fs *ofs) |
| { |
| return ovl_same_dev(ofs) ? ofs->xino_mode : 0; |
| } |
| |
| static inline void ovl_inode_lock(struct inode *inode) |
| { |
| mutex_lock(&OVL_I(inode)->lock); |
| } |
| |
| static inline int ovl_inode_lock_interruptible(struct inode *inode) |
| { |
| return mutex_lock_interruptible(&OVL_I(inode)->lock); |
| } |
| |
| static inline void ovl_inode_unlock(struct inode *inode) |
| { |
| mutex_unlock(&OVL_I(inode)->lock); |
| } |
| |
| |
| /* namei.c */ |
| 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) |
| { |
| if (fh_len < sizeof(struct ovl_fh)) |
| return -EINVAL; |
| |
| return ovl_check_fb_len(&fh->fb, fh_len - OVL_FH_WIRE_OFFSET); |
| } |
| |
| struct dentry *ovl_decode_real_fh(struct ovl_fs *ofs, struct ovl_fh *fh, |
| struct vfsmount *mnt, bool connected); |
| int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected, |
| struct dentry *upperdentry, struct ovl_path **stackp); |
| int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry, |
| enum ovl_xattr ox, const struct ovl_fh *fh, |
| bool is_upper, bool set); |
| int ovl_verify_origin_xattr(struct ovl_fs *ofs, struct dentry *dentry, |
| enum ovl_xattr ox, struct dentry *real, |
| bool is_upper, bool set); |
| struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index, |
| bool connected); |
| int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index); |
| int ovl_get_index_name_fh(const struct ovl_fh *fh, struct qstr *name); |
| int ovl_get_index_name(struct ovl_fs *ofs, struct dentry *origin, |
| struct qstr *name); |
| struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh); |
| struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper, |
| struct dentry *origin, bool verify); |
| int ovl_path_next(int idx, struct dentry *dentry, struct path *path); |
| int ovl_verify_lowerdata(struct dentry *dentry); |
| struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, |
| unsigned int flags); |
| bool ovl_lower_positive(struct dentry *dentry); |
| |
| static inline int ovl_verify_origin_fh(struct ovl_fs *ofs, struct dentry *upper, |
| const struct ovl_fh *fh, bool set) |
| { |
| return ovl_verify_set_fh(ofs, upper, OVL_XATTR_ORIGIN, fh, false, set); |
| } |
| |
| static inline int ovl_verify_origin(struct ovl_fs *ofs, struct dentry *upper, |
| struct dentry *origin, bool set) |
| { |
| return ovl_verify_origin_xattr(ofs, upper, OVL_XATTR_ORIGIN, origin, |
| false, set); |
| } |
| |
| static inline int ovl_verify_upper(struct ovl_fs *ofs, struct dentry *index, |
| struct dentry *upper, bool set) |
| { |
| return ovl_verify_origin_xattr(ofs, index, OVL_XATTR_UPPER, upper, |
| true, set); |
| } |
| |
| /* readdir.c */ |
| extern const struct file_operations ovl_dir_operations; |
| struct file *ovl_dir_real_file(const struct file *file, bool want_upper); |
| int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list); |
| void ovl_cleanup_whiteouts(struct ovl_fs *ofs, struct dentry *upper, |
| struct list_head *list); |
| void ovl_cache_free(struct list_head *list); |
| void ovl_dir_cache_free(struct inode *inode); |
| int ovl_check_d_type_supported(const struct path *realpath); |
| int ovl_workdir_cleanup(struct ovl_fs *ofs, struct inode *dir, |
| struct vfsmount *mnt, struct dentry *dentry, int level); |
| int ovl_indexdir_cleanup(struct ovl_fs *ofs); |
| |
| /* |
| * Can we iterate real dir directly? |
| * |
| * Non-merge dir may contain whiteouts from a time it was a merge upper, before |
| * lower dir was removed under it and possibly before it was rotated from upper |
| * to lower layer. |
| */ |
| static inline bool ovl_dir_is_real(struct inode *dir) |
| { |
| return !ovl_test_flag(OVL_WHITEOUTS, dir); |
| } |
| |
| /* inode.c */ |
| int ovl_set_nlink_upper(struct dentry *dentry); |
| int ovl_set_nlink_lower(struct dentry *dentry); |
| unsigned int ovl_get_nlink(struct ovl_fs *ofs, struct dentry *lowerdentry, |
| struct dentry *upperdentry, |
| unsigned int fallback); |
| int ovl_permission(struct mnt_idmap *idmap, struct inode *inode, |
| int mask); |
| |
| #ifdef CONFIG_FS_POSIX_ACL |
| struct posix_acl *do_ovl_get_acl(struct mnt_idmap *idmap, |
| struct inode *inode, int type, |
| bool rcu, bool noperm); |
| static inline struct posix_acl *ovl_get_inode_acl(struct inode *inode, int type, |
| bool rcu) |
| { |
| return do_ovl_get_acl(&nop_mnt_idmap, inode, type, rcu, true); |
| } |
| static inline struct posix_acl *ovl_get_acl(struct mnt_idmap *idmap, |
| struct dentry *dentry, int type) |
| { |
| return do_ovl_get_acl(idmap, d_inode(dentry), type, false, false); |
| } |
| int ovl_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, |
| struct posix_acl *acl, int type); |
| struct posix_acl *ovl_get_acl_path(const struct path *path, |
| const char *acl_name, bool noperm); |
| #else |
| #define ovl_get_inode_acl NULL |
| #define ovl_get_acl NULL |
| #define ovl_set_acl NULL |
| static inline struct posix_acl *ovl_get_acl_path(const struct path *path, |
| const char *acl_name, |
| bool noperm) |
| { |
| return NULL; |
| } |
| #endif |
| |
| int ovl_update_time(struct inode *inode, int flags); |
| bool ovl_is_private_xattr(struct super_block *sb, const char *name); |
| |
| struct ovl_inode_params { |
| struct inode *newinode; |
| struct dentry *upperdentry; |
| struct ovl_entry *oe; |
| bool index; |
| char *redirect; |
| char *lowerdata_redirect; |
| }; |
| void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip, |
| unsigned long ino, int fsid); |
| struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev); |
| struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real, |
| bool is_upper); |
| bool ovl_lookup_trap_inode(struct super_block *sb, struct dentry *dir); |
| struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir); |
| struct inode *ovl_get_inode(struct super_block *sb, |
| struct ovl_inode_params *oip); |
| void ovl_copyattr(struct inode *to); |
| |
| /* vfs inode flags copied from real to ovl inode */ |
| #define OVL_COPY_I_FLAGS_MASK (S_SYNC | S_NOATIME | S_APPEND | S_IMMUTABLE) |
| /* vfs inode flags read from overlay.protattr xattr to ovl inode */ |
| #define OVL_PROT_I_FLAGS_MASK (S_APPEND | S_IMMUTABLE) |
| |
| /* |
| * fileattr flags copied from lower to upper inode on copy up. |
| * We cannot copy up immutable/append-only flags, because that would prevent |
| * linking temp inode to upper dir, so we store them in xattr instead. |
| */ |
| #define OVL_COPY_FS_FLAGS_MASK (FS_SYNC_FL | FS_NOATIME_FL) |
| #define OVL_COPY_FSX_FLAGS_MASK (FS_XFLAG_SYNC | FS_XFLAG_NOATIME) |
| #define OVL_PROT_FS_FLAGS_MASK (FS_APPEND_FL | FS_IMMUTABLE_FL) |
| #define OVL_PROT_FSX_FLAGS_MASK (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE) |
| |
| void ovl_check_protattr(struct inode *inode, struct dentry *upper); |
| int ovl_set_protattr(struct inode *inode, struct dentry *upper, |
| struct fileattr *fa); |
| |
| static inline void ovl_copyflags(struct inode *from, struct inode *to) |
| { |
| unsigned int mask = OVL_COPY_I_FLAGS_MASK; |
| |
| inode_set_flags(to, from->i_flags & mask, mask); |
| } |
| |
| /* dir.c */ |
| extern const struct inode_operations ovl_dir_inode_operations; |
| int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir, |
| struct dentry *dentry); |
| struct ovl_cattr { |
| dev_t rdev; |
| umode_t mode; |
| const char *link; |
| struct dentry *hardlink; |
| }; |
| |
| #define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) }) |
| |
| int ovl_mkdir_real(struct ovl_fs *ofs, struct inode *dir, |
| struct dentry **newdentry, umode_t mode); |
| struct dentry *ovl_create_real(struct ovl_fs *ofs, |
| struct inode *dir, struct dentry *newdentry, |
| struct ovl_cattr *attr); |
| int ovl_cleanup(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry); |
| struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdir); |
| struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir, |
| struct ovl_cattr *attr); |
| |
| /* file.c */ |
| extern const struct file_operations ovl_file_operations; |
| int __init ovl_aio_request_cache_init(void); |
| void ovl_aio_request_cache_destroy(void); |
| int ovl_real_fileattr_get(const struct path *realpath, struct fileattr *fa); |
| int ovl_real_fileattr_set(const struct path *realpath, struct fileattr *fa); |
| int ovl_fileattr_get(struct dentry *dentry, struct fileattr *fa); |
| int ovl_fileattr_set(struct mnt_idmap *idmap, |
| struct dentry *dentry, struct fileattr *fa); |
| |
| /* copy_up.c */ |
| int ovl_copy_up(struct dentry *dentry); |
| int ovl_copy_up_with_data(struct dentry *dentry); |
| int ovl_maybe_copy_up(struct dentry *dentry, int flags); |
| int ovl_copy_xattr(struct super_block *sb, const struct path *path, struct dentry *new); |
| int ovl_set_attr(struct ovl_fs *ofs, struct dentry *upper, struct kstat *stat); |
| struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real, |
| bool is_upper); |
| struct ovl_fh *ovl_get_origin_fh(struct ovl_fs *ofs, struct dentry *origin); |
| int ovl_set_origin_fh(struct ovl_fs *ofs, const struct ovl_fh *fh, |
| struct dentry *upper); |
| |
| /* export.c */ |
| extern const struct export_operations ovl_export_operations; |
| extern const struct export_operations ovl_export_fid_operations; |
| |
| /* super.c */ |
| int ovl_fill_super(struct super_block *sb, struct fs_context *fc); |
| |
| /* Will this overlay be forced to mount/remount ro? */ |
| static inline bool ovl_force_readonly(struct ovl_fs *ofs) |
| { |
| return (!ovl_upper_mnt(ofs) || !ofs->workdir); |
| } |
| |
| /* xattr.c */ |
| |
| const struct xattr_handler * const *ovl_xattr_handlers(struct ovl_fs *ofs); |
| int ovl_setattr(struct mnt_idmap *idmap, struct dentry *dentry, |
| struct iattr *attr); |
| int ovl_getattr(struct mnt_idmap *idmap, const struct path *path, |
| struct kstat *stat, u32 request_mask, unsigned int flags); |
| ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size); |
