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linux/fs/overlayfs/overlayfs.h
Linus Torvalds 6d5b940e1e vfs-6.16-rc1.async.dir 
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Merge tag 'vfs-6.16-rc1.async.dir' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs directory lookup updates from Christian Brauner:
 "This contains cleanups for the lookup_one*() family of helpers.

  We expose a set of functions with names containing "lookup_one_len"
  and others without the "_len". This difference has nothing to do with
  "len". It's rater a historical accident that can be confusing.

  The functions without "_len" take a "mnt_idmap" pointer. This is found
  in the "vfsmount" and that is an important question when choosing
  which to use: do you have a vfsmount, or are you "inside" the
  filesystem. A related question is "is permission checking relevant
  here?".

  nfsd and cachefiles *do* have a vfsmount but *don't* use the non-_len
  functions. They pass nop_mnt_idmap and refuse to work on filesystems
  which have any other idmap.

  This work changes nfsd and cachefile to use the lookup_one family of
  functions and to explictily pass &nop_mnt_idmap which is consistent
  with all other vfs interfaces used where &nop_mnt_idmap is explicitly
  passed.

  The remaining uses of the "_one" functions do not require permission
  checks so these are renamed to be "_noperm" and the permission
  checking is removed.

  This series also changes these lookup function to take a qstr instead
  of separate name and len. In many cases this simplifies the call"

* tag 'vfs-6.16-rc1.async.dir' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  VFS: change lookup_one_common and lookup_noperm_common to take a qstr
  Use try_lookup_noperm() instead of d_hash_and_lookup() outside of VFS
  VFS: rename lookup_one_len family to lookup_noperm and remove permission check
  cachefiles: Use lookup_one() rather than lookup_one_len()
  nfsd: Use lookup_one() rather than lookup_one_len()
  VFS: improve interface for lookup_one functions
2025-05-26 08:02:43 -07:00

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/* 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,
};
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,
/* Lower stack may contain xwhiteout entries */
OVL_E_XWHITEOUTS,
};
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;
}
/* No atime modification on underlying */
#define OVL_OPEN_FLAGS (O_NOATIME)
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 struct dentry *ovl_do_mkdir(struct ovl_fs *ofs,
struct inode *dir,
struct dentry *dentry,
umode_t mode)
{
dentry = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode);
pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, PTR_ERR_OR_ZERO(dentry));
return dentry;
}
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), &QSTR_LEN(name, len), base);
}
static inline bool ovl_open_flags_need_copy_up(int flags)
{
if (!flags)
return false;
return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC));
}
/* 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);
void ovl_revert_creds(const struct cred *old_cred);
static inline const struct cred *ovl_creds(struct super_block *sb)
{
return OVL_FS(sb)->creator_cred;
}
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_xwhiteouts(struct dentry *dentry);
void ovl_dentry_set_xwhiteouts(struct dentry *dentry);
void ovl_layer_set_xwhiteouts(struct ovl_fs *ofs,
const struct ovl_layer *layer);
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);
char ovl_get_dir_xattr_val(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_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_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_get_dir_xattr_val(ofs, &upperpath, OVL_XATTR_IMPURE) == 'y';
}
static inline char ovl_get_opaquedir_val(struct ovl_fs *ofs,
const struct path *path)
{
return ovl_get_dir_xattr_val(ofs, path, OVL_XATTR_OPAQUE);
}
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,
const struct ovl_layer **layer);
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) })
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 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);
struct ovl_file;
struct ovl_file *ovl_file_alloc(struct file *realfile);
void ovl_file_free(struct ovl_file *of);
/* 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 inode *realinode,
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);
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