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-rw-r--r--fs/overlayfs/overlayfs.h840
1 files changed, 840 insertions, 0 deletions
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
new file mode 100644
index 0000000000..09ca82ed0f
--- /dev/null
+++ b/fs/overlayfs/overlayfs.h
@@ -0,0 +1,840 @@
+/* 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_USER_PREFIX XATTR_USER_PREFIX OVL_XATTR_NAMESPACE
+
+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,
+};
+
+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_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);
+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_init_uuid_xattr(struct super_block *sb, struct ovl_fs *ofs,
+ const struct path *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, 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(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(struct ovl_fs *ofs, struct dentry *upper,
+ struct dentry *origin, bool set)
+{
+ return ovl_verify_set_fh(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_set_fh(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_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);
+int ovl_permission(struct mnt_idmap *idmap, struct inode *inode,
+ int mask);
+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);
+
+#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);
+int ovl_set_origin(struct ovl_fs *ofs, struct dentry *lower,
+ 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);
+}