1 /* 2 * 3 * Copyright (C) 2011 Novell Inc. 4 * 5 * This program is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 as published by 7 * the Free Software Foundation. 8 */ 9 10 #include <linux/kernel.h> 11 12 enum ovl_path_type { 13 __OVL_PATH_UPPER = (1 << 0), 14 __OVL_PATH_MERGE = (1 << 1), 15 }; 16 17 #define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER) 18 #define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE) 19 20 #define OVL_XATTR_PREFIX XATTR_TRUSTED_PREFIX "overlay." 21 #define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX "opaque" 22 #define OVL_XATTR_REDIRECT OVL_XATTR_PREFIX "redirect" 23 24 #define OVL_ISUPPER_MASK 1UL 25 26 static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry) 27 { 28 int err = vfs_rmdir(dir, dentry); 29 pr_debug("rmdir(%pd2) = %i\n", dentry, err); 30 return err; 31 } 32 33 static inline int ovl_do_unlink(struct inode *dir, struct dentry *dentry) 34 { 35 int err = vfs_unlink(dir, dentry, NULL); 36 pr_debug("unlink(%pd2) = %i\n", dentry, err); 37 return err; 38 } 39 40 static inline int ovl_do_link(struct dentry *old_dentry, struct inode *dir, 41 struct dentry *new_dentry, bool debug) 42 { 43 int err = vfs_link(old_dentry, dir, new_dentry, NULL); 44 if (debug) { 45 pr_debug("link(%pd2, %pd2) = %i\n", 46 old_dentry, new_dentry, err); 47 } 48 return err; 49 } 50 51 static inline int ovl_do_create(struct inode *dir, struct dentry *dentry, 52 umode_t mode, bool debug) 53 { 54 int err = vfs_create(dir, dentry, mode, true); 55 if (debug) 56 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err); 57 return err; 58 } 59 60 static inline int ovl_do_mkdir(struct inode *dir, struct dentry *dentry, 61 umode_t mode, bool debug) 62 { 63 int err = vfs_mkdir(dir, dentry, mode); 64 if (debug) 65 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err); 66 return err; 67 } 68 69 static inline int ovl_do_mknod(struct inode *dir, struct dentry *dentry, 70 umode_t mode, dev_t dev, bool debug) 71 { 72 int err = vfs_mknod(dir, dentry, mode, dev); 73 if (debug) { 74 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", 75 dentry, mode, dev, err); 76 } 77 return err; 78 } 79 80 static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry, 81 const char *oldname, bool debug) 82 { 83 int err = vfs_symlink(dir, dentry, oldname); 84 if (debug) 85 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err); 86 return err; 87 } 88 89 static inline int ovl_do_setxattr(struct dentry *dentry, const char *name, 90 const void *value, size_t size, int flags) 91 { 92 int err = vfs_setxattr(dentry, name, value, size, flags); 93 pr_debug("setxattr(%pd2, \"%s\", \"%*s\", 0x%x) = %i\n", 94 dentry, name, (int) size, (char *) value, flags, err); 95 return err; 96 } 97 98 static inline int ovl_do_removexattr(struct dentry *dentry, const char *name) 99 { 100 int err = vfs_removexattr(dentry, name); 101 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err); 102 return err; 103 } 104 105 static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry, 106 struct inode *newdir, struct dentry *newdentry, 107 unsigned int flags) 108 { 109 int err; 110 111 pr_debug("rename(%pd2, %pd2, 0x%x)\n", 112 olddentry, newdentry, flags); 113 114 err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags); 115 116 if (err) { 117 pr_debug("...rename(%pd2, %pd2, ...) = %i\n", 118 olddentry, newdentry, err); 119 } 120 return err; 121 } 122 123 static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry) 124 { 125 int err = vfs_whiteout(dir, dentry); 126 pr_debug("whiteout(%pd2) = %i\n", dentry, err); 127 return err; 128 } 129 130 static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode) 131 { 132 struct dentry *ret = vfs_tmpfile(dentry, mode, 0); 133 int err = IS_ERR(ret) ? PTR_ERR(ret) : 0; 134 135 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err); 136 return ret; 137 } 138 139 static inline struct inode *ovl_inode_real(struct inode *inode, bool *is_upper) 140 { 141 unsigned long x = (unsigned long) READ_ONCE(inode->i_private); 142 143 if (is_upper) 144 *is_upper = x & OVL_ISUPPER_MASK; 145 146 return (struct inode *) (x & ~OVL_ISUPPER_MASK); 147 } 148 149 /* util.c */ 150 int ovl_want_write(struct dentry *dentry); 151 void ovl_drop_write(struct dentry *dentry); 152 struct dentry *ovl_workdir(struct dentry *dentry); 153 const struct cred *ovl_override_creds(struct super_block *sb); 154 struct ovl_entry *ovl_alloc_entry(unsigned int numlower); 155 bool ovl_dentry_remote(struct dentry *dentry); 156 bool ovl_dentry_weird(struct dentry *dentry); 157 enum ovl_path_type ovl_path_type(struct dentry *dentry); 158 void ovl_path_upper(struct dentry *dentry, struct path *path); 159 void ovl_path_lower(struct dentry *dentry, struct path *path); 160 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); 161 struct dentry *ovl_dentry_upper(struct dentry *dentry); 162 struct dentry *ovl_dentry_lower(struct dentry *dentry); 163 struct dentry *ovl_dentry_real(struct dentry *dentry); 164 struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry); 165 void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache); 166 bool ovl_dentry_is_opaque(struct dentry *dentry); 167 bool ovl_dentry_is_whiteout(struct dentry *dentry); 168 void ovl_dentry_set_opaque(struct dentry *dentry); 169 bool ovl_redirect_dir(struct super_block *sb); 170 void ovl_clear_redirect_dir(struct super_block *sb); 171 const char *ovl_dentry_get_redirect(struct dentry *dentry); 172 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect); 173 void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry); 174 void ovl_inode_init(struct inode *inode, struct inode *realinode, 175 bool is_upper); 176 void ovl_inode_update(struct inode *inode, struct inode *upperinode); 177 void ovl_dentry_version_inc(struct dentry *dentry); 178 u64 ovl_dentry_version_get(struct dentry *dentry); 179 bool ovl_is_whiteout(struct dentry *dentry); 180 struct file *ovl_path_open(struct path *path, int flags); 181 int ovl_copy_up_start(struct dentry *dentry); 182 void ovl_copy_up_end(struct dentry *dentry); 183 184 /* namei.c */ 185 int ovl_path_next(int idx, struct dentry *dentry, struct path *path); 186 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags); 187 bool ovl_lower_positive(struct dentry *dentry); 188 189 /* readdir.c */ 190 extern const struct file_operations ovl_dir_operations; 191 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list); 192 void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list); 193 void ovl_cache_free(struct list_head *list); 194 int ovl_check_d_type_supported(struct path *realpath); 195 void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt, 196 struct dentry *dentry, int level); 197 198 /* inode.c */ 199 int ovl_setattr(struct dentry *dentry, struct iattr *attr); 200 int ovl_permission(struct inode *inode, int mask); 201 int ovl_xattr_set(struct dentry *dentry, const char *name, const void *value, 202 size_t size, int flags); 203 int ovl_xattr_get(struct dentry *dentry, const char *name, 204 void *value, size_t size); 205 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size); 206 struct posix_acl *ovl_get_acl(struct inode *inode, int type); 207 int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags); 208 int ovl_update_time(struct inode *inode, struct timespec *ts, int flags); 209 bool ovl_is_private_xattr(const char *name); 210 211 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev); 212 struct inode *ovl_get_inode(struct super_block *sb, struct inode *realinode); 213 static inline void ovl_copyattr(struct inode *from, struct inode *to) 214 { 215 to->i_uid = from->i_uid; 216 to->i_gid = from->i_gid; 217 to->i_mode = from->i_mode; 218 to->i_atime = from->i_atime; 219 to->i_mtime = from->i_mtime; 220 to->i_ctime = from->i_ctime; 221 } 222 223 /* dir.c */ 224 extern const struct inode_operations ovl_dir_inode_operations; 225 struct dentry *ovl_lookup_temp(struct dentry *workdir, struct dentry *dentry); 226 struct cattr { 227 dev_t rdev; 228 umode_t mode; 229 const char *link; 230 }; 231 int ovl_create_real(struct inode *dir, struct dentry *newdentry, 232 struct cattr *attr, 233 struct dentry *hardlink, bool debug); 234 void ovl_cleanup(struct inode *dir, struct dentry *dentry); 235 236 /* copy_up.c */ 237 int ovl_copy_up(struct dentry *dentry); 238 int ovl_copy_up_flags(struct dentry *dentry, int flags); 239 int ovl_copy_xattr(struct dentry *old, struct dentry *new); 240 int ovl_set_attr(struct dentry *upper, struct kstat *stat); 241