433 lines
15 KiB
C
433 lines
15 KiB
C
/*
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*
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* Copyright (C) 2011 Novell Inc.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/uuid.h>
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#include <linux/fs.h>
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#include "ovl_entry.h"
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enum ovl_path_type {
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__OVL_PATH_UPPER = (1 << 0),
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__OVL_PATH_MERGE = (1 << 1),
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__OVL_PATH_ORIGIN = (1 << 2),
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};
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#define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER)
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#define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE)
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#define OVL_TYPE_ORIGIN(type) ((type) & __OVL_PATH_ORIGIN)
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#define OVL_XATTR_PREFIX XATTR_TRUSTED_PREFIX "overlay."
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#define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX "opaque"
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#define OVL_XATTR_REDIRECT OVL_XATTR_PREFIX "redirect"
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#define OVL_XATTR_ORIGIN OVL_XATTR_PREFIX "origin"
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#define OVL_XATTR_IMPURE OVL_XATTR_PREFIX "impure"
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#define OVL_XATTR_NLINK OVL_XATTR_PREFIX "nlink"
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#define OVL_XATTR_UPPER OVL_XATTR_PREFIX "upper"
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#define OVL_XATTR_METACOPY OVL_XATTR_PREFIX "metacopy"
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enum ovl_inode_flag {
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/* Pure upper dir that may contain non pure upper entries */
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OVL_IMPURE,
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/* Non-merge dir that may contain whiteout entries */
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OVL_WHITEOUTS,
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OVL_INDEX,
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OVL_UPPERDATA,
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/* Inode number will remain constant over copy up. */
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OVL_CONST_INO,
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};
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enum ovl_entry_flag {
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OVL_E_UPPER_ALIAS,
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OVL_E_OPAQUE,
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OVL_E_CONNECTED,
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};
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/*
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* The tuple (fh,uuid) is a universal unique identifier for a copy up origin,
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* where:
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* origin.fh - exported file handle of the lower file
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* origin.uuid - uuid of the lower filesystem
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*/
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#define OVL_FH_VERSION 0
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#define OVL_FH_MAGIC 0xfb
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/* CPU byte order required for fid decoding: */
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#define OVL_FH_FLAG_BIG_ENDIAN (1 << 0)
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#define OVL_FH_FLAG_ANY_ENDIAN (1 << 1)
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/* Is the real inode encoded in fid an upper inode? */
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#define OVL_FH_FLAG_PATH_UPPER (1 << 2)
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#define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \
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OVL_FH_FLAG_PATH_UPPER)
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#if defined(__LITTLE_ENDIAN)
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#define OVL_FH_FLAG_CPU_ENDIAN 0
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#elif defined(__BIG_ENDIAN)
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#define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN
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#else
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#error Endianness not defined
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#endif
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/* The type returned by overlay exportfs ops when encoding an ovl_fh handle */
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#define OVL_FILEID 0xfb
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/* On-disk and in-memeory format for redirect by file handle */
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struct ovl_fh {
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u8 version; /* 0 */
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u8 magic; /* 0xfb */
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u8 len; /* size of this header + size of fid */
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u8 flags; /* OVL_FH_FLAG_* */
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u8 type; /* fid_type of fid */
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uuid_t uuid; /* uuid of filesystem */
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u8 fid[0]; /* file identifier */
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} __packed;
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static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
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{
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int err = vfs_rmdir(dir, dentry);
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pr_debug("rmdir(%pd2) = %i\n", dentry, err);
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return err;
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}
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static inline int ovl_do_unlink(struct inode *dir, struct dentry *dentry)
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{
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int err = vfs_unlink(dir, dentry, NULL);
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pr_debug("unlink(%pd2) = %i\n", dentry, err);
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return err;
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}
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static inline int ovl_do_link(struct dentry *old_dentry, struct inode *dir,
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struct dentry *new_dentry)
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{
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int err = vfs_link(old_dentry, dir, new_dentry, NULL);
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pr_debug("link(%pd2, %pd2) = %i\n", old_dentry, new_dentry, err);
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return err;
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}
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static inline int ovl_do_create(struct inode *dir, struct dentry *dentry,
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umode_t mode)
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{
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int err = vfs_create(dir, dentry, mode, true);
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pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
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return err;
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}
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static inline int ovl_do_mkdir(struct inode *dir, struct dentry *dentry,
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umode_t mode)
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{
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int err = vfs_mkdir(dir, dentry, mode);
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pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
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return err;
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}
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static inline int ovl_do_mknod(struct inode *dir, struct dentry *dentry,
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umode_t mode, dev_t dev)
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{
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int err = vfs_mknod(dir, dentry, mode, dev);
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pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err);
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return err;
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}
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static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry,
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const char *oldname)
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{
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int err = vfs_symlink(dir, dentry, oldname);
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pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
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return err;
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}
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static inline int ovl_do_setxattr(struct dentry *dentry, const char *name,
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const void *value, size_t size, int flags)
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{
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int err = vfs_setxattr(dentry, name, value, size, flags);
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pr_debug("setxattr(%pd2, \"%s\", \"%*pE\", %zu, 0x%x) = %i\n",
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dentry, name, min((int)size, 48), value, size, flags, err);
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return err;
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}
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static inline int ovl_do_removexattr(struct dentry *dentry, const char *name)
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{
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int err = vfs_removexattr(dentry, name);
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pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
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return err;
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}
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static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry,
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struct inode *newdir, struct dentry *newdentry,
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unsigned int flags)
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{
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int err;
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pr_debug("rename(%pd2, %pd2, 0x%x)\n", olddentry, newdentry, flags);
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err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags);
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if (err) {
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pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
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olddentry, newdentry, err);
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}
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return err;
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}
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static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry)
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{
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int err = vfs_whiteout(dir, dentry);
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pr_debug("whiteout(%pd2) = %i\n", dentry, err);
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return err;
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}
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static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode)
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{
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struct dentry *ret = vfs_tmpfile(dentry, mode, 0);
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int err = PTR_ERR_OR_ZERO(ret);
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pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);
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return ret;
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}
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static inline bool ovl_open_flags_need_copy_up(int flags)
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{
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if (!flags)
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return false;
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return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC));
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}
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/* util.c */
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int ovl_want_write(struct dentry *dentry);
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void ovl_drop_write(struct dentry *dentry);
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struct dentry *ovl_workdir(struct dentry *dentry);
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const struct cred *ovl_override_creds(struct super_block *sb);
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struct super_block *ovl_same_sb(struct super_block *sb);
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int ovl_can_decode_fh(struct super_block *sb);
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struct dentry *ovl_indexdir(struct super_block *sb);
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bool ovl_index_all(struct super_block *sb);
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bool ovl_verify_lower(struct super_block *sb);
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struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
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bool ovl_dentry_remote(struct dentry *dentry);
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bool ovl_dentry_weird(struct dentry *dentry);
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enum ovl_path_type ovl_path_type(struct dentry *dentry);
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void ovl_path_upper(struct dentry *dentry, struct path *path);
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void ovl_path_lower(struct dentry *dentry, struct path *path);
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void ovl_path_lowerdata(struct dentry *dentry, struct path *path);
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enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
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struct dentry *ovl_dentry_upper(struct dentry *dentry);
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struct dentry *ovl_dentry_lower(struct dentry *dentry);
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struct dentry *ovl_dentry_lowerdata(struct dentry *dentry);
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struct ovl_layer *ovl_layer_lower(struct dentry *dentry);
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struct dentry *ovl_dentry_real(struct dentry *dentry);
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struct dentry *ovl_i_dentry_upper(struct inode *inode);
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struct inode *ovl_inode_upper(struct inode *inode);
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struct inode *ovl_inode_lower(struct inode *inode);
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struct inode *ovl_inode_lowerdata(struct inode *inode);
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struct inode *ovl_inode_real(struct inode *inode);
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struct inode *ovl_inode_realdata(struct inode *inode);
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struct ovl_dir_cache *ovl_dir_cache(struct inode *inode);
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void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache);
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void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry);
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void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry);
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bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry);
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bool ovl_dentry_is_opaque(struct dentry *dentry);
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bool ovl_dentry_is_whiteout(struct dentry *dentry);
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void ovl_dentry_set_opaque(struct dentry *dentry);
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bool ovl_dentry_has_upper_alias(struct dentry *dentry);
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void ovl_dentry_set_upper_alias(struct dentry *dentry);
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bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags);
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bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags);
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bool ovl_has_upperdata(struct inode *inode);
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void ovl_set_upperdata(struct inode *inode);
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bool ovl_redirect_dir(struct super_block *sb);
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const char *ovl_dentry_get_redirect(struct dentry *dentry);
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void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
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void ovl_inode_init(struct inode *inode, struct dentry *upperdentry,
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struct dentry *lowerdentry, struct dentry *lowerdata);
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void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);
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void ovl_dir_modified(struct dentry *dentry, bool impurity);
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u64 ovl_dentry_version_get(struct dentry *dentry);
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bool ovl_is_whiteout(struct dentry *dentry);
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struct file *ovl_path_open(struct path *path, int flags);
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int ovl_copy_up_start(struct dentry *dentry, int flags);
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void ovl_copy_up_end(struct dentry *dentry);
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bool ovl_already_copied_up(struct dentry *dentry, int flags);
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bool ovl_check_origin_xattr(struct dentry *dentry);
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bool ovl_check_dir_xattr(struct dentry *dentry, const char *name);
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int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
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const char *name, const void *value, size_t size,
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int xerr);
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int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);
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void ovl_set_flag(unsigned long flag, struct inode *inode);
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void ovl_clear_flag(unsigned long flag, struct inode *inode);
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bool ovl_test_flag(unsigned long flag, struct inode *inode);
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bool ovl_inuse_trylock(struct dentry *dentry);
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void ovl_inuse_unlock(struct dentry *dentry);
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bool ovl_need_index(struct dentry *dentry);
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int ovl_nlink_start(struct dentry *dentry);
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void ovl_nlink_end(struct dentry *dentry);
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int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir);
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int ovl_check_metacopy_xattr(struct dentry *dentry);
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bool ovl_is_metacopy_dentry(struct dentry *dentry);
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char *ovl_get_redirect_xattr(struct dentry *dentry, int padding);
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ssize_t ovl_getxattr(struct dentry *dentry, char *name, char **value,
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size_t padding);
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static inline bool ovl_is_impuredir(struct dentry *dentry)
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{
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return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE);
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}
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static inline unsigned int ovl_xino_bits(struct super_block *sb)
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{
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struct ovl_fs *ofs = sb->s_fs_info;
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return ofs->xino_bits;
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}
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static inline int ovl_inode_lock(struct inode *inode)
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{
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return mutex_lock_interruptible(&OVL_I(inode)->lock);
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}
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static inline void ovl_inode_unlock(struct inode *inode)
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{
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mutex_unlock(&OVL_I(inode)->lock);
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}
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/* namei.c */
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int ovl_check_fh_len(struct ovl_fh *fh, int fh_len);
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struct dentry *ovl_decode_real_fh(struct ovl_fh *fh, struct vfsmount *mnt,
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bool connected);
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int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected,
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struct dentry *upperdentry, struct ovl_path **stackp);
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int ovl_verify_set_fh(struct dentry *dentry, const char *name,
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struct dentry *real, bool is_upper, bool set);
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struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index);
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int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index);
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int ovl_get_index_name(struct dentry *origin, struct qstr *name);
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struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh);
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struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper,
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struct dentry *origin, bool verify);
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int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
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struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
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unsigned int flags);
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bool ovl_lower_positive(struct dentry *dentry);
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static inline int ovl_verify_origin(struct dentry *upper,
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struct dentry *origin, bool set)
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{
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return ovl_verify_set_fh(upper, OVL_XATTR_ORIGIN, origin, false, set);
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}
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static inline int ovl_verify_upper(struct dentry *index,
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struct dentry *upper, bool set)
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{
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return ovl_verify_set_fh(index, OVL_XATTR_UPPER, upper, true, set);
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}
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/* readdir.c */
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extern const struct file_operations ovl_dir_operations;
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int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
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void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
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void ovl_cache_free(struct list_head *list);
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void ovl_dir_cache_free(struct inode *inode);
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int ovl_check_d_type_supported(struct path *realpath);
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void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
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struct dentry *dentry, int level);
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int ovl_indexdir_cleanup(struct ovl_fs *ofs);
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/* inode.c */
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int ovl_set_nlink_upper(struct dentry *dentry);
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int ovl_set_nlink_lower(struct dentry *dentry);
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unsigned int ovl_get_nlink(struct dentry *lowerdentry,
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struct dentry *upperdentry,
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unsigned int fallback);
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int ovl_setattr(struct dentry *dentry, struct iattr *attr);
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int ovl_getattr(const struct path *path, struct kstat *stat,
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u32 request_mask, unsigned int flags);
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int ovl_permission(struct inode *inode, int mask);
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int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
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const void *value, size_t size, int flags);
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int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
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void *value, size_t size);
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ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
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struct posix_acl *ovl_get_acl(struct inode *inode, int type);
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int ovl_update_time(struct inode *inode, struct timespec64 *ts, int flags);
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bool ovl_is_private_xattr(const char *name);
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struct ovl_inode_params {
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struct inode *newinode;
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struct dentry *upperdentry;
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struct ovl_path *lowerpath;
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struct dentry *index;
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unsigned int numlower;
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char *redirect;
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struct dentry *lowerdata;
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};
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struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
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struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real,
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bool is_upper);
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struct inode *ovl_get_inode(struct super_block *sb,
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struct ovl_inode_params *oip);
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static inline void ovl_copyattr(struct inode *from, struct inode *to)
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{
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to->i_uid = from->i_uid;
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to->i_gid = from->i_gid;
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to->i_mode = from->i_mode;
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to->i_atime = from->i_atime;
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to->i_mtime = from->i_mtime;
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to->i_ctime = from->i_ctime;
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i_size_write(to, i_size_read(from));
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}
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static inline void ovl_copyflags(struct inode *from, struct inode *to)
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{
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unsigned int mask = S_SYNC | S_IMMUTABLE | S_APPEND | S_NOATIME;
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inode_set_flags(to, from->i_flags & mask, mask);
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}
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/* dir.c */
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extern const struct inode_operations ovl_dir_inode_operations;
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int ovl_cleanup_and_whiteout(struct dentry *workdir, struct inode *dir,
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struct dentry *dentry);
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struct ovl_cattr {
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dev_t rdev;
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umode_t mode;
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const char *link;
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struct dentry *hardlink;
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};
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#define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) })
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struct dentry *ovl_create_real(struct inode *dir, struct dentry *newdentry,
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struct ovl_cattr *attr);
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int ovl_cleanup(struct inode *dir, struct dentry *dentry);
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struct dentry *ovl_create_temp(struct dentry *workdir, struct ovl_cattr *attr);
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/* file.c */
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extern const struct file_operations ovl_file_operations;
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/* copy_up.c */
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int ovl_copy_up(struct dentry *dentry);
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int ovl_copy_up_with_data(struct dentry *dentry);
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int ovl_copy_up_flags(struct dentry *dentry, int flags);
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int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags);
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int ovl_copy_xattr(struct dentry *old, struct dentry *new);
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int ovl_set_attr(struct dentry *upper, struct kstat *stat);
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struct ovl_fh *ovl_encode_real_fh(struct dentry *real, bool is_upper);
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int ovl_set_origin(struct dentry *dentry, struct dentry *lower,
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struct dentry *upper);
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/* export.c */
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extern const struct export_operations ovl_export_operations;
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