Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 1 | /* |
| 2 | * fs/sdcardfs/inode.c |
| 3 | * |
| 4 | * Copyright (c) 2013 Samsung Electronics Co. Ltd |
| 5 | * Authors: Daeho Jeong, Woojoong Lee, Seunghwan Hyun, |
| 6 | * Sunghwan Yun, Sungjong Seo |
| 7 | * |
| 8 | * This program has been developed as a stackable file system based on |
| 9 | * the WrapFS which written by |
| 10 | * |
| 11 | * Copyright (c) 1998-2011 Erez Zadok |
| 12 | * Copyright (c) 2009 Shrikar Archak |
| 13 | * Copyright (c) 2003-2011 Stony Brook University |
| 14 | * Copyright (c) 2003-2011 The Research Foundation of SUNY |
| 15 | * |
| 16 | * This file is dual licensed. It may be redistributed and/or modified |
| 17 | * under the terms of the Apache 2.0 License OR version 2 of the GNU |
| 18 | * General Public License. |
| 19 | */ |
| 20 | |
| 21 | #include "sdcardfs.h" |
Daniel Rosenberg | 2b31462 | 2016-04-13 16:38:34 -0700 | [diff] [blame] | 22 | #include <linux/fs_struct.h> |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 23 | |
| 24 | /* Do not directly use this function. Use OVERRIDE_CRED() instead. */ |
| 25 | const struct cred * override_fsids(struct sdcardfs_sb_info* sbi) |
| 26 | { |
| 27 | struct cred * cred; |
| 28 | const struct cred * old_cred; |
| 29 | |
| 30 | cred = prepare_creds(); |
| 31 | if (!cred) |
| 32 | return NULL; |
| 33 | |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 34 | cred->fsuid = make_kuid(&init_user_ns, sbi->options.fs_low_uid); |
| 35 | cred->fsgid = make_kgid(&init_user_ns, sbi->options.fs_low_gid); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 36 | |
| 37 | old_cred = override_creds(cred); |
| 38 | |
| 39 | return old_cred; |
| 40 | } |
| 41 | |
| 42 | /* Do not directly use this function, use REVERT_CRED() instead. */ |
| 43 | void revert_fsids(const struct cred * old_cred) |
| 44 | { |
| 45 | const struct cred * cur_cred; |
| 46 | |
| 47 | cur_cred = current->cred; |
| 48 | revert_creds(old_cred); |
| 49 | put_cred(cur_cred); |
| 50 | } |
| 51 | |
| 52 | static int sdcardfs_create(struct inode *dir, struct dentry *dentry, |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 53 | umode_t mode, bool want_excl) |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 54 | { |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 55 | int err; |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 56 | struct dentry *lower_dentry; |
| 57 | struct dentry *lower_parent_dentry = NULL; |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 58 | struct path lower_path; |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 59 | const struct cred *saved_cred = NULL; |
Daniel Rosenberg | 2b31462 | 2016-04-13 16:38:34 -0700 | [diff] [blame] | 60 | struct fs_struct *saved_fs; |
| 61 | struct fs_struct *copied_fs; |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 62 | |
Daniel Rosenberg | 497ac90 | 2016-02-03 21:08:21 -0800 | [diff] [blame] | 63 | if(!check_caller_access_to_name(dir, dentry->d_name.name)) { |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 64 | printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n" |
| 65 | " dentry: %s, task:%s\n", |
| 66 | __func__, dentry->d_name.name, current->comm); |
| 67 | err = -EACCES; |
| 68 | goto out_eacces; |
| 69 | } |
| 70 | |
| 71 | /* save current_cred and override it */ |
| 72 | OVERRIDE_CRED(SDCARDFS_SB(dir->i_sb), saved_cred); |
| 73 | |
| 74 | sdcardfs_get_lower_path(dentry, &lower_path); |
| 75 | lower_dentry = lower_path.dentry; |
| 76 | lower_parent_dentry = lock_parent(lower_dentry); |
| 77 | |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 78 | /* set last 16bytes of mode field to 0664 */ |
| 79 | mode = (mode & S_IFMT) | 00664; |
Daniel Rosenberg | 2b31462 | 2016-04-13 16:38:34 -0700 | [diff] [blame] | 80 | |
| 81 | /* temporarily change umask for lower fs write */ |
| 82 | saved_fs = current->fs; |
| 83 | copied_fs = copy_fs_struct(current->fs); |
| 84 | if (!copied_fs) { |
| 85 | err = -ENOMEM; |
| 86 | goto out_unlock; |
| 87 | } |
| 88 | current->fs = copied_fs; |
| 89 | current->fs->umask = 0; |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 90 | err = vfs_create(d_inode(lower_parent_dentry), lower_dentry, mode, want_excl); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 91 | if (err) |
| 92 | goto out; |
| 93 | |
Daniel Rosenberg | 497ac90 | 2016-02-03 21:08:21 -0800 | [diff] [blame] | 94 | err = sdcardfs_interpose(dentry, dir->i_sb, &lower_path, SDCARDFS_I(dir)->userid); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 95 | if (err) |
| 96 | goto out; |
| 97 | fsstack_copy_attr_times(dir, sdcardfs_lower_inode(dir)); |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 98 | fsstack_copy_inode_size(dir, d_inode(lower_parent_dentry)); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 99 | |
| 100 | out: |
Daniel Rosenberg | 2b31462 | 2016-04-13 16:38:34 -0700 | [diff] [blame] | 101 | current->fs = saved_fs; |
| 102 | free_fs_struct(copied_fs); |
| 103 | out_unlock: |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 104 | unlock_dir(lower_parent_dentry); |
| 105 | sdcardfs_put_lower_path(dentry, &lower_path); |
| 106 | REVERT_CRED(saved_cred); |
| 107 | out_eacces: |
| 108 | return err; |
| 109 | } |
| 110 | |
| 111 | #if 0 |
| 112 | static int sdcardfs_link(struct dentry *old_dentry, struct inode *dir, |
| 113 | struct dentry *new_dentry) |
| 114 | { |
| 115 | struct dentry *lower_old_dentry; |
| 116 | struct dentry *lower_new_dentry; |
| 117 | struct dentry *lower_dir_dentry; |
| 118 | u64 file_size_save; |
| 119 | int err; |
| 120 | struct path lower_old_path, lower_new_path; |
| 121 | |
| 122 | OVERRIDE_CRED(SDCARDFS_SB(dir->i_sb)); |
| 123 | |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 124 | file_size_save = i_size_read(d_inode(old_dentry)); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 125 | sdcardfs_get_lower_path(old_dentry, &lower_old_path); |
| 126 | sdcardfs_get_lower_path(new_dentry, &lower_new_path); |
| 127 | lower_old_dentry = lower_old_path.dentry; |
| 128 | lower_new_dentry = lower_new_path.dentry; |
| 129 | lower_dir_dentry = lock_parent(lower_new_dentry); |
| 130 | |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 131 | err = vfs_link(lower_old_dentry, d_inode(lower_dir_dentry), |
| 132 | lower_new_dentry, NULL); |
| 133 | if (err || !d_inode(lower_new_dentry)) |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 134 | goto out; |
| 135 | |
| 136 | err = sdcardfs_interpose(new_dentry, dir->i_sb, &lower_new_path); |
| 137 | if (err) |
| 138 | goto out; |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 139 | fsstack_copy_attr_times(dir, d_inode(lower_new_dentry)); |
| 140 | fsstack_copy_inode_size(dir, d_inode(lower_new_dentry)); |
| 141 | set_nlink(d_inode(old_dentry), |
| 142 | sdcardfs_lower_inode(d_inode(old_dentry))->i_nlink); |
| 143 | i_size_write(d_inode(new_dentry), file_size_save); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 144 | out: |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 145 | unlock_dir(lower_dir_dentry); |
| 146 | sdcardfs_put_lower_path(old_dentry, &lower_old_path); |
| 147 | sdcardfs_put_lower_path(new_dentry, &lower_new_path); |
| 148 | REVERT_CRED(); |
| 149 | return err; |
| 150 | } |
| 151 | #endif |
| 152 | |
| 153 | static int sdcardfs_unlink(struct inode *dir, struct dentry *dentry) |
| 154 | { |
| 155 | int err; |
| 156 | struct dentry *lower_dentry; |
| 157 | struct inode *lower_dir_inode = sdcardfs_lower_inode(dir); |
| 158 | struct dentry *lower_dir_dentry; |
| 159 | struct path lower_path; |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 160 | const struct cred *saved_cred = NULL; |
| 161 | |
Daniel Rosenberg | 497ac90 | 2016-02-03 21:08:21 -0800 | [diff] [blame] | 162 | if(!check_caller_access_to_name(dir, dentry->d_name.name)) { |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 163 | printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n" |
| 164 | " dentry: %s, task:%s\n", |
| 165 | __func__, dentry->d_name.name, current->comm); |
| 166 | err = -EACCES; |
| 167 | goto out_eacces; |
| 168 | } |
| 169 | |
| 170 | /* save current_cred and override it */ |
| 171 | OVERRIDE_CRED(SDCARDFS_SB(dir->i_sb), saved_cred); |
| 172 | |
| 173 | sdcardfs_get_lower_path(dentry, &lower_path); |
| 174 | lower_dentry = lower_path.dentry; |
| 175 | dget(lower_dentry); |
| 176 | lower_dir_dentry = lock_parent(lower_dentry); |
| 177 | |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 178 | err = vfs_unlink(lower_dir_inode, lower_dentry, NULL); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 179 | |
| 180 | /* |
| 181 | * Note: unlinking on top of NFS can cause silly-renamed files. |
| 182 | * Trying to delete such files results in EBUSY from NFS |
| 183 | * below. Silly-renamed files will get deleted by NFS later on, so |
| 184 | * we just need to detect them here and treat such EBUSY errors as |
| 185 | * if the upper file was successfully deleted. |
| 186 | */ |
| 187 | if (err == -EBUSY && lower_dentry->d_flags & DCACHE_NFSFS_RENAMED) |
| 188 | err = 0; |
| 189 | if (err) |
| 190 | goto out; |
| 191 | fsstack_copy_attr_times(dir, lower_dir_inode); |
| 192 | fsstack_copy_inode_size(dir, lower_dir_inode); |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 193 | set_nlink(d_inode(dentry), |
| 194 | sdcardfs_lower_inode(d_inode(dentry))->i_nlink); |
| 195 | d_inode(dentry)->i_ctime = dir->i_ctime; |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 196 | d_drop(dentry); /* this is needed, else LTP fails (VFS won't do it) */ |
| 197 | out: |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 198 | unlock_dir(lower_dir_dentry); |
| 199 | dput(lower_dentry); |
| 200 | sdcardfs_put_lower_path(dentry, &lower_path); |
| 201 | REVERT_CRED(saved_cred); |
| 202 | out_eacces: |
| 203 | return err; |
| 204 | } |
| 205 | |
| 206 | #if 0 |
| 207 | static int sdcardfs_symlink(struct inode *dir, struct dentry *dentry, |
| 208 | const char *symname) |
| 209 | { |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 210 | int err; |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 211 | struct dentry *lower_dentry; |
| 212 | struct dentry *lower_parent_dentry = NULL; |
| 213 | struct path lower_path; |
| 214 | |
| 215 | OVERRIDE_CRED(SDCARDFS_SB(dir->i_sb)); |
| 216 | |
| 217 | sdcardfs_get_lower_path(dentry, &lower_path); |
| 218 | lower_dentry = lower_path.dentry; |
| 219 | lower_parent_dentry = lock_parent(lower_dentry); |
| 220 | |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 221 | err = vfs_symlink(d_inode(lower_parent_dentry), lower_dentry, symname); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 222 | if (err) |
| 223 | goto out; |
| 224 | err = sdcardfs_interpose(dentry, dir->i_sb, &lower_path); |
| 225 | if (err) |
| 226 | goto out; |
| 227 | fsstack_copy_attr_times(dir, sdcardfs_lower_inode(dir)); |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 228 | fsstack_copy_inode_size(dir, d_inode(lower_parent_dentry)); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 229 | |
| 230 | out: |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 231 | unlock_dir(lower_parent_dentry); |
| 232 | sdcardfs_put_lower_path(dentry, &lower_path); |
| 233 | REVERT_CRED(); |
| 234 | return err; |
| 235 | } |
| 236 | #endif |
| 237 | |
| 238 | static int touch(char *abs_path, mode_t mode) { |
| 239 | struct file *filp = filp_open(abs_path, O_RDWR|O_CREAT|O_EXCL|O_NOFOLLOW, mode); |
| 240 | if (IS_ERR(filp)) { |
| 241 | if (PTR_ERR(filp) == -EEXIST) { |
| 242 | return 0; |
| 243 | } |
| 244 | else { |
| 245 | printk(KERN_ERR "sdcardfs: failed to open(%s): %ld\n", |
| 246 | abs_path, PTR_ERR(filp)); |
| 247 | return PTR_ERR(filp); |
| 248 | } |
| 249 | } |
| 250 | filp_close(filp, current->files); |
| 251 | return 0; |
| 252 | } |
| 253 | |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 254 | static int sdcardfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 255 | { |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 256 | int err; |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 257 | int make_nomedia_in_obb = 0; |
| 258 | struct dentry *lower_dentry; |
| 259 | struct dentry *lower_parent_dentry = NULL; |
| 260 | struct path lower_path; |
| 261 | struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb); |
| 262 | const struct cred *saved_cred = NULL; |
| 263 | struct sdcardfs_inode_info *pi = SDCARDFS_I(dir); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 264 | int touch_err = 0; |
Daniel Rosenberg | 2b31462 | 2016-04-13 16:38:34 -0700 | [diff] [blame] | 265 | struct fs_struct *saved_fs; |
| 266 | struct fs_struct *copied_fs; |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 267 | |
Daniel Rosenberg | 497ac90 | 2016-02-03 21:08:21 -0800 | [diff] [blame] | 268 | if(!check_caller_access_to_name(dir, dentry->d_name.name)) { |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 269 | printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n" |
| 270 | " dentry: %s, task:%s\n", |
| 271 | __func__, dentry->d_name.name, current->comm); |
| 272 | err = -EACCES; |
| 273 | goto out_eacces; |
| 274 | } |
| 275 | |
| 276 | /* save current_cred and override it */ |
| 277 | OVERRIDE_CRED(SDCARDFS_SB(dir->i_sb), saved_cred); |
| 278 | |
| 279 | /* check disk space */ |
| 280 | if (!check_min_free_space(dentry, 0, 1)) { |
| 281 | printk(KERN_INFO "sdcardfs: No minimum free space.\n"); |
| 282 | err = -ENOSPC; |
| 283 | goto out_revert; |
| 284 | } |
| 285 | |
| 286 | /* the lower_dentry is negative here */ |
| 287 | sdcardfs_get_lower_path(dentry, &lower_path); |
| 288 | lower_dentry = lower_path.dentry; |
| 289 | lower_parent_dentry = lock_parent(lower_dentry); |
| 290 | |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 291 | /* set last 16bytes of mode field to 0775 */ |
| 292 | mode = (mode & S_IFMT) | 00775; |
Daniel Rosenberg | 2b31462 | 2016-04-13 16:38:34 -0700 | [diff] [blame] | 293 | |
| 294 | /* temporarily change umask for lower fs write */ |
| 295 | saved_fs = current->fs; |
| 296 | copied_fs = copy_fs_struct(current->fs); |
| 297 | if (!copied_fs) { |
| 298 | err = -ENOMEM; |
Daniel Rosenberg | 9480415 | 2016-09-26 14:48:22 -0700 | [diff] [blame^] | 299 | unlock_dir(lower_parent_dentry); |
Daniel Rosenberg | 2b31462 | 2016-04-13 16:38:34 -0700 | [diff] [blame] | 300 | goto out_unlock; |
| 301 | } |
| 302 | current->fs = copied_fs; |
| 303 | current->fs->umask = 0; |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 304 | err = vfs_mkdir(d_inode(lower_parent_dentry), lower_dentry, mode); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 305 | |
Daniel Rosenberg | 9480415 | 2016-09-26 14:48:22 -0700 | [diff] [blame^] | 306 | if (err) { |
| 307 | unlock_dir(lower_parent_dentry); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 308 | goto out; |
Daniel Rosenberg | 9480415 | 2016-09-26 14:48:22 -0700 | [diff] [blame^] | 309 | } |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 310 | |
| 311 | /* if it is a local obb dentry, setup it with the base obbpath */ |
| 312 | if(need_graft_path(dentry)) { |
| 313 | |
| 314 | err = setup_obb_dentry(dentry, &lower_path); |
| 315 | if(err) { |
| 316 | /* if the sbi->obbpath is not available, the lower_path won't be |
| 317 | * changed by setup_obb_dentry() but the lower path is saved to |
Daniel Rosenberg | 497ac90 | 2016-02-03 21:08:21 -0800 | [diff] [blame] | 318 | * its orig_path. this dentry will be revalidated later. |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 319 | * but now, the lower_path should be NULL */ |
| 320 | sdcardfs_put_reset_lower_path(dentry); |
| 321 | |
| 322 | /* the newly created lower path which saved to its orig_path or |
| 323 | * the lower_path is the base obbpath. |
Daniel Rosenberg | 497ac90 | 2016-02-03 21:08:21 -0800 | [diff] [blame] | 324 | * therefore, an additional path_get is required */ |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 325 | path_get(&lower_path); |
| 326 | } else |
| 327 | make_nomedia_in_obb = 1; |
| 328 | } |
| 329 | |
Daniel Rosenberg | 497ac90 | 2016-02-03 21:08:21 -0800 | [diff] [blame] | 330 | err = sdcardfs_interpose(dentry, dir->i_sb, &lower_path, pi->userid); |
Daniel Rosenberg | 9480415 | 2016-09-26 14:48:22 -0700 | [diff] [blame^] | 331 | if (err) { |
| 332 | unlock_dir(lower_parent_dentry); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 333 | goto out; |
Daniel Rosenberg | 9480415 | 2016-09-26 14:48:22 -0700 | [diff] [blame^] | 334 | } |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 335 | |
| 336 | fsstack_copy_attr_times(dir, sdcardfs_lower_inode(dir)); |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 337 | fsstack_copy_inode_size(dir, d_inode(lower_parent_dentry)); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 338 | /* update number of links on parent directory */ |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 339 | set_nlink(dir, sdcardfs_lower_inode(dir)->i_nlink); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 340 | |
Daniel Rosenberg | 9480415 | 2016-09-26 14:48:22 -0700 | [diff] [blame^] | 341 | unlock_dir(lower_parent_dentry); |
| 342 | |
Daniel Rosenberg | 497ac90 | 2016-02-03 21:08:21 -0800 | [diff] [blame] | 343 | if ((!sbi->options.multiuser) && (!strcasecmp(dentry->d_name.name, "obb")) |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 344 | && (pi->perm == PERM_ANDROID) && (pi->userid == 0)) |
| 345 | make_nomedia_in_obb = 1; |
| 346 | |
| 347 | /* When creating /Android/data and /Android/obb, mark them as .nomedia */ |
| 348 | if (make_nomedia_in_obb || |
| 349 | ((pi->perm == PERM_ANDROID) && (!strcasecmp(dentry->d_name.name, "data")))) { |
Daniel Rosenberg | 2b31462 | 2016-04-13 16:38:34 -0700 | [diff] [blame] | 350 | set_fs_pwd(current->fs, &lower_path); |
| 351 | touch_err = touch(".nomedia", 0664); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 352 | if (touch_err) { |
Daniel Rosenberg | 2b31462 | 2016-04-13 16:38:34 -0700 | [diff] [blame] | 353 | printk(KERN_ERR "sdcardfs: failed to create .nomedia in %s: %d\n", |
| 354 | lower_path.dentry->d_name.name, touch_err); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 355 | goto out; |
| 356 | } |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 357 | } |
| 358 | out: |
Daniel Rosenberg | 2b31462 | 2016-04-13 16:38:34 -0700 | [diff] [blame] | 359 | current->fs = saved_fs; |
| 360 | free_fs_struct(copied_fs); |
| 361 | out_unlock: |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 362 | sdcardfs_put_lower_path(dentry, &lower_path); |
| 363 | out_revert: |
| 364 | REVERT_CRED(saved_cred); |
| 365 | out_eacces: |
| 366 | return err; |
| 367 | } |
| 368 | |
| 369 | static int sdcardfs_rmdir(struct inode *dir, struct dentry *dentry) |
| 370 | { |
| 371 | struct dentry *lower_dentry; |
| 372 | struct dentry *lower_dir_dentry; |
| 373 | int err; |
| 374 | struct path lower_path; |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 375 | const struct cred *saved_cred = NULL; |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 376 | |
Daniel Rosenberg | 497ac90 | 2016-02-03 21:08:21 -0800 | [diff] [blame] | 377 | if(!check_caller_access_to_name(dir, dentry->d_name.name)) { |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 378 | printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n" |
| 379 | " dentry: %s, task:%s\n", |
| 380 | __func__, dentry->d_name.name, current->comm); |
| 381 | err = -EACCES; |
| 382 | goto out_eacces; |
| 383 | } |
| 384 | |
| 385 | /* save current_cred and override it */ |
| 386 | OVERRIDE_CRED(SDCARDFS_SB(dir->i_sb), saved_cred); |
| 387 | |
| 388 | /* sdcardfs_get_real_lower(): in case of remove an user's obb dentry |
| 389 | * the dentry on the original path should be deleted. */ |
| 390 | sdcardfs_get_real_lower(dentry, &lower_path); |
| 391 | |
| 392 | lower_dentry = lower_path.dentry; |
| 393 | lower_dir_dentry = lock_parent(lower_dentry); |
| 394 | |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 395 | err = vfs_rmdir(d_inode(lower_dir_dentry), lower_dentry); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 396 | if (err) |
| 397 | goto out; |
| 398 | |
| 399 | d_drop(dentry); /* drop our dentry on success (why not VFS's job?) */ |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 400 | if (d_inode(dentry)) |
| 401 | clear_nlink(d_inode(dentry)); |
| 402 | fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry)); |
| 403 | fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry)); |
| 404 | set_nlink(dir, d_inode(lower_dir_dentry)->i_nlink); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 405 | |
| 406 | out: |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 407 | unlock_dir(lower_dir_dentry); |
| 408 | sdcardfs_put_real_lower(dentry, &lower_path); |
| 409 | REVERT_CRED(saved_cred); |
| 410 | out_eacces: |
| 411 | return err; |
| 412 | } |
| 413 | |
| 414 | #if 0 |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 415 | static int sdcardfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 416 | dev_t dev) |
| 417 | { |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 418 | int err; |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 419 | struct dentry *lower_dentry; |
| 420 | struct dentry *lower_parent_dentry = NULL; |
| 421 | struct path lower_path; |
| 422 | |
| 423 | OVERRIDE_CRED(SDCARDFS_SB(dir->i_sb)); |
| 424 | |
| 425 | sdcardfs_get_lower_path(dentry, &lower_path); |
| 426 | lower_dentry = lower_path.dentry; |
| 427 | lower_parent_dentry = lock_parent(lower_dentry); |
| 428 | |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 429 | err = vfs_mknod(d_inode(lower_parent_dentry), lower_dentry, mode, dev); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 430 | if (err) |
| 431 | goto out; |
| 432 | |
| 433 | err = sdcardfs_interpose(dentry, dir->i_sb, &lower_path); |
| 434 | if (err) |
| 435 | goto out; |
| 436 | fsstack_copy_attr_times(dir, sdcardfs_lower_inode(dir)); |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 437 | fsstack_copy_inode_size(dir, d_inode(lower_parent_dentry)); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 438 | |
| 439 | out: |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 440 | unlock_dir(lower_parent_dentry); |
| 441 | sdcardfs_put_lower_path(dentry, &lower_path); |
| 442 | REVERT_CRED(); |
| 443 | return err; |
| 444 | } |
| 445 | #endif |
| 446 | |
| 447 | /* |
| 448 | * The locking rules in sdcardfs_rename are complex. We could use a simpler |
| 449 | * superblock-level name-space lock for renames and copy-ups. |
| 450 | */ |
| 451 | static int sdcardfs_rename(struct inode *old_dir, struct dentry *old_dentry, |
| 452 | struct inode *new_dir, struct dentry *new_dentry) |
| 453 | { |
| 454 | int err = 0; |
| 455 | struct dentry *lower_old_dentry = NULL; |
| 456 | struct dentry *lower_new_dentry = NULL; |
| 457 | struct dentry *lower_old_dir_dentry = NULL; |
| 458 | struct dentry *lower_new_dir_dentry = NULL; |
| 459 | struct dentry *trap = NULL; |
| 460 | struct dentry *new_parent = NULL; |
| 461 | struct path lower_old_path, lower_new_path; |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 462 | const struct cred *saved_cred = NULL; |
| 463 | |
Daniel Rosenberg | 497ac90 | 2016-02-03 21:08:21 -0800 | [diff] [blame] | 464 | if(!check_caller_access_to_name(old_dir, old_dentry->d_name.name) || |
| 465 | !check_caller_access_to_name(new_dir, new_dentry->d_name.name)) { |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 466 | printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n" |
| 467 | " new_dentry: %s, task:%s\n", |
| 468 | __func__, new_dentry->d_name.name, current->comm); |
| 469 | err = -EACCES; |
| 470 | goto out_eacces; |
| 471 | } |
| 472 | |
| 473 | /* save current_cred and override it */ |
| 474 | OVERRIDE_CRED(SDCARDFS_SB(old_dir->i_sb), saved_cred); |
| 475 | |
| 476 | sdcardfs_get_real_lower(old_dentry, &lower_old_path); |
| 477 | sdcardfs_get_lower_path(new_dentry, &lower_new_path); |
| 478 | lower_old_dentry = lower_old_path.dentry; |
| 479 | lower_new_dentry = lower_new_path.dentry; |
| 480 | lower_old_dir_dentry = dget_parent(lower_old_dentry); |
| 481 | lower_new_dir_dentry = dget_parent(lower_new_dentry); |
| 482 | |
| 483 | trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry); |
| 484 | /* source should not be ancestor of target */ |
| 485 | if (trap == lower_old_dentry) { |
| 486 | err = -EINVAL; |
| 487 | goto out; |
| 488 | } |
| 489 | /* target should not be ancestor of source */ |
| 490 | if (trap == lower_new_dentry) { |
| 491 | err = -ENOTEMPTY; |
| 492 | goto out; |
| 493 | } |
| 494 | |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 495 | err = vfs_rename(d_inode(lower_old_dir_dentry), lower_old_dentry, |
| 496 | d_inode(lower_new_dir_dentry), lower_new_dentry, |
| 497 | NULL, 0); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 498 | if (err) |
| 499 | goto out; |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 500 | |
| 501 | /* Copy attrs from lower dir, but i_uid/i_gid */ |
Daniel Rosenberg | 497ac90 | 2016-02-03 21:08:21 -0800 | [diff] [blame] | 502 | sdcardfs_copy_and_fix_attrs(new_dir, d_inode(lower_new_dir_dentry)); |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 503 | fsstack_copy_inode_size(new_dir, d_inode(lower_new_dir_dentry)); |
Daniel Rosenberg | 497ac90 | 2016-02-03 21:08:21 -0800 | [diff] [blame] | 504 | |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 505 | if (new_dir != old_dir) { |
Daniel Rosenberg | 497ac90 | 2016-02-03 21:08:21 -0800 | [diff] [blame] | 506 | sdcardfs_copy_and_fix_attrs(old_dir, d_inode(lower_old_dir_dentry)); |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 507 | fsstack_copy_inode_size(old_dir, d_inode(lower_old_dir_dentry)); |
Daniel Rosenberg | 497ac90 | 2016-02-03 21:08:21 -0800 | [diff] [blame] | 508 | |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 509 | /* update the derived permission of the old_dentry |
| 510 | * with its new parent |
| 511 | */ |
| 512 | new_parent = dget_parent(new_dentry); |
| 513 | if(new_parent) { |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 514 | if(d_inode(old_dentry)) { |
Daniel Rosenberg | 497ac90 | 2016-02-03 21:08:21 -0800 | [diff] [blame] | 515 | update_derived_permission_lock(old_dentry); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 516 | } |
| 517 | dput(new_parent); |
| 518 | } |
| 519 | } |
Daniel Rosenberg | 497ac90 | 2016-02-03 21:08:21 -0800 | [diff] [blame] | 520 | /* At this point, not all dentry information has been moved, so |
| 521 | * we pass along new_dentry for the name.*/ |
Daniel Rosenberg | 497ac90 | 2016-02-03 21:08:21 -0800 | [diff] [blame] | 522 | get_derived_permission_new(new_dentry->d_parent, old_dentry, new_dentry); |
| 523 | fix_derived_permission(d_inode(old_dentry)); |
Daniel Rosenberg | 5080d24 | 2016-05-18 16:57:10 -0700 | [diff] [blame] | 524 | fixup_top_recursive(old_dentry); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 525 | out: |
| 526 | unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry); |
| 527 | dput(lower_old_dir_dentry); |
| 528 | dput(lower_new_dir_dentry); |
| 529 | sdcardfs_put_real_lower(old_dentry, &lower_old_path); |
| 530 | sdcardfs_put_lower_path(new_dentry, &lower_new_path); |
| 531 | REVERT_CRED(saved_cred); |
| 532 | out_eacces: |
| 533 | return err; |
| 534 | } |
| 535 | |
| 536 | #if 0 |
| 537 | static int sdcardfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz) |
| 538 | { |
| 539 | int err; |
| 540 | struct dentry *lower_dentry; |
| 541 | struct path lower_path; |
| 542 | /* XXX readlink does not requires overriding credential */ |
| 543 | |
| 544 | sdcardfs_get_lower_path(dentry, &lower_path); |
| 545 | lower_dentry = lower_path.dentry; |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 546 | if (!d_inode(lower_dentry)->i_op || |
| 547 | !d_inode(lower_dentry)->i_op->readlink) { |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 548 | err = -EINVAL; |
| 549 | goto out; |
| 550 | } |
| 551 | |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 552 | err = d_inode(lower_dentry)->i_op->readlink(lower_dentry, |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 553 | buf, bufsiz); |
| 554 | if (err < 0) |
| 555 | goto out; |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 556 | fsstack_copy_attr_atime(d_inode(dentry), d_inode(lower_dentry)); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 557 | |
| 558 | out: |
| 559 | sdcardfs_put_lower_path(dentry, &lower_path); |
| 560 | return err; |
| 561 | } |
| 562 | #endif |
| 563 | |
| 564 | #if 0 |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 565 | static const char *sdcardfs_follow_link(struct dentry *dentry, void **cookie) |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 566 | { |
| 567 | char *buf; |
| 568 | int len = PAGE_SIZE, err; |
| 569 | mm_segment_t old_fs; |
| 570 | |
| 571 | /* This is freed by the put_link method assuming a successful call. */ |
| 572 | buf = kmalloc(len, GFP_KERNEL); |
| 573 | if (!buf) { |
| 574 | buf = ERR_PTR(-ENOMEM); |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 575 | return buf; |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 576 | } |
| 577 | |
| 578 | /* read the symlink, and then we will follow it */ |
| 579 | old_fs = get_fs(); |
| 580 | set_fs(KERNEL_DS); |
| 581 | err = sdcardfs_readlink(dentry, buf, len); |
| 582 | set_fs(old_fs); |
| 583 | if (err < 0) { |
| 584 | kfree(buf); |
| 585 | buf = ERR_PTR(err); |
| 586 | } else { |
| 587 | buf[err] = '\0'; |
| 588 | } |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 589 | return *cookie = buf; |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 590 | } |
| 591 | #endif |
| 592 | |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 593 | static int sdcardfs_permission(struct inode *inode, int mask) |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 594 | { |
| 595 | int err; |
Daniel Rosenberg | 5080d24 | 2016-05-18 16:57:10 -0700 | [diff] [blame] | 596 | struct inode *top = grab_top(SDCARDFS_I(inode)); |
| 597 | |
| 598 | if (!top) |
| 599 | return -EINVAL; |
| 600 | /* Ensure owner is up to date */ |
| 601 | if (!uid_eq(inode->i_uid, top->i_uid)) { |
| 602 | SDCARDFS_I(inode)->d_uid = SDCARDFS_I(top)->d_uid; |
| 603 | fix_derived_permission(inode); |
| 604 | } |
| 605 | release_top(SDCARDFS_I(inode)); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 606 | |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 607 | /* |
| 608 | * Permission check on sdcardfs inode. |
| 609 | * Calling process should have AID_SDCARD_RW permission |
| 610 | */ |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 611 | err = generic_permission(inode, mask); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 612 | |
| 613 | /* XXX |
| 614 | * Original sdcardfs code calls inode_permission(lower_inode,.. ) |
| 615 | * for checking inode permission. But doing such things here seems |
| 616 | * duplicated work, because the functions called after this func, |
| 617 | * such as vfs_create, vfs_unlink, vfs_rename, and etc, |
| 618 | * does exactly same thing, i.e., they calls inode_permission(). |
| 619 | * So we just let they do the things. |
| 620 | * If there are any security hole, just uncomment following if block. |
| 621 | */ |
| 622 | #if 0 |
| 623 | if (!err) { |
| 624 | /* |
| 625 | * Permission check on lower_inode(=EXT4). |
| 626 | * we check it with AID_MEDIA_RW permission |
| 627 | */ |
| 628 | struct inode *lower_inode; |
| 629 | OVERRIDE_CRED(SDCARDFS_SB(inode->sb)); |
| 630 | |
| 631 | lower_inode = sdcardfs_lower_inode(inode); |
| 632 | err = inode_permission(lower_inode, mask); |
| 633 | |
| 634 | REVERT_CRED(); |
| 635 | } |
| 636 | #endif |
| 637 | return err; |
| 638 | |
| 639 | } |
| 640 | |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 641 | static int sdcardfs_setattr(struct dentry *dentry, struct iattr *ia) |
| 642 | { |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 643 | int err; |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 644 | struct dentry *lower_dentry; |
| 645 | struct inode *inode; |
| 646 | struct inode *lower_inode; |
| 647 | struct path lower_path; |
| 648 | struct iattr lower_ia; |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 649 | struct dentry *parent; |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 650 | |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 651 | inode = d_inode(dentry); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 652 | |
| 653 | /* |
| 654 | * Check if user has permission to change inode. We don't check if |
| 655 | * this user can change the lower inode: that should happen when |
| 656 | * calling notify_change on the lower inode. |
| 657 | */ |
| 658 | err = inode_change_ok(inode, ia); |
| 659 | |
| 660 | /* no vfs_XXX operations required, cred overriding will be skipped. wj*/ |
| 661 | if (!err) { |
| 662 | /* check the Android group ID */ |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 663 | parent = dget_parent(dentry); |
Daniel Rosenberg | 497ac90 | 2016-02-03 21:08:21 -0800 | [diff] [blame] | 664 | if(!check_caller_access_to_name(d_inode(parent), dentry->d_name.name)) { |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 665 | printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n" |
| 666 | " dentry: %s, task:%s\n", |
| 667 | __func__, dentry->d_name.name, current->comm); |
| 668 | err = -EACCES; |
| 669 | } |
| 670 | dput(parent); |
| 671 | } |
| 672 | |
| 673 | if (err) |
| 674 | goto out_err; |
| 675 | |
| 676 | sdcardfs_get_lower_path(dentry, &lower_path); |
| 677 | lower_dentry = lower_path.dentry; |
| 678 | lower_inode = sdcardfs_lower_inode(inode); |
| 679 | |
| 680 | /* prepare our own lower struct iattr (with the lower file) */ |
| 681 | memcpy(&lower_ia, ia, sizeof(lower_ia)); |
| 682 | if (ia->ia_valid & ATTR_FILE) |
| 683 | lower_ia.ia_file = sdcardfs_lower_file(ia->ia_file); |
| 684 | |
| 685 | lower_ia.ia_valid &= ~(ATTR_UID | ATTR_GID | ATTR_MODE); |
| 686 | |
| 687 | /* |
| 688 | * If shrinking, first truncate upper level to cancel writing dirty |
| 689 | * pages beyond the new eof; and also if its' maxbytes is more |
| 690 | * limiting (fail with -EFBIG before making any change to the lower |
| 691 | * level). There is no need to vmtruncate the upper level |
| 692 | * afterwards in the other cases: we fsstack_copy_inode_size from |
| 693 | * the lower level. |
| 694 | */ |
| 695 | if (current->mm) |
| 696 | down_write(¤t->mm->mmap_sem); |
| 697 | if (ia->ia_valid & ATTR_SIZE) { |
| 698 | err = inode_newsize_ok(inode, ia->ia_size); |
| 699 | if (err) { |
| 700 | if (current->mm) |
| 701 | up_write(¤t->mm->mmap_sem); |
| 702 | goto out; |
| 703 | } |
| 704 | truncate_setsize(inode, ia->ia_size); |
| 705 | } |
| 706 | |
| 707 | /* |
| 708 | * mode change is for clearing setuid/setgid bits. Allow lower fs |
| 709 | * to interpret this in its own way. |
| 710 | */ |
| 711 | if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID)) |
| 712 | lower_ia.ia_valid &= ~ATTR_MODE; |
| 713 | |
| 714 | /* notify the (possibly copied-up) lower inode */ |
| 715 | /* |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 716 | * Note: we use d_inode(lower_dentry), because lower_inode may be |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 717 | * unlinked (no inode->i_sb and i_ino==0. This happens if someone |
| 718 | * tries to open(), unlink(), then ftruncate() a file. |
| 719 | */ |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 720 | mutex_lock(&d_inode(lower_dentry)->i_mutex); |
| 721 | err = notify_change(lower_dentry, &lower_ia, /* note: lower_ia */ |
| 722 | NULL); |
| 723 | mutex_unlock(&d_inode(lower_dentry)->i_mutex); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 724 | if (current->mm) |
| 725 | up_write(¤t->mm->mmap_sem); |
| 726 | if (err) |
| 727 | goto out; |
| 728 | |
Daniel Rosenberg | 497ac90 | 2016-02-03 21:08:21 -0800 | [diff] [blame] | 729 | /* get attributes from the lower inode and update derived permissions */ |
| 730 | sdcardfs_copy_and_fix_attrs(inode, lower_inode); |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 731 | |
| 732 | /* |
| 733 | * Not running fsstack_copy_inode_size(inode, lower_inode), because |
| 734 | * VFS should update our inode size, and notify_change on |
| 735 | * lower_inode should update its size. |
| 736 | */ |
| 737 | |
| 738 | out: |
| 739 | sdcardfs_put_lower_path(dentry, &lower_path); |
| 740 | out_err: |
| 741 | return err; |
| 742 | } |
| 743 | |
Daniel Rosenberg | 5080d24 | 2016-05-18 16:57:10 -0700 | [diff] [blame] | 744 | static int sdcardfs_fillattr(struct inode *inode, struct kstat *stat) |
| 745 | { |
| 746 | struct sdcardfs_inode_info *info = SDCARDFS_I(inode); |
| 747 | struct inode *top = grab_top(info); |
| 748 | if (!top) |
| 749 | return -EINVAL; |
| 750 | |
| 751 | stat->dev = inode->i_sb->s_dev; |
| 752 | stat->ino = inode->i_ino; |
| 753 | stat->mode = (inode->i_mode & S_IFMT) | get_mode(SDCARDFS_I(top)); |
| 754 | stat->nlink = inode->i_nlink; |
| 755 | stat->uid = make_kuid(&init_user_ns, SDCARDFS_I(top)->d_uid); |
| 756 | stat->gid = make_kgid(&init_user_ns, get_gid(SDCARDFS_I(top))); |
| 757 | stat->rdev = inode->i_rdev; |
| 758 | stat->size = i_size_read(inode); |
| 759 | stat->atime = inode->i_atime; |
| 760 | stat->mtime = inode->i_mtime; |
| 761 | stat->ctime = inode->i_ctime; |
| 762 | stat->blksize = (1 << inode->i_blkbits); |
| 763 | stat->blocks = inode->i_blocks; |
| 764 | release_top(info); |
| 765 | return 0; |
| 766 | } |
| 767 | |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 768 | static int sdcardfs_getattr(struct vfsmount *mnt, struct dentry *dentry, |
| 769 | struct kstat *stat) |
| 770 | { |
| 771 | struct dentry *lower_dentry; |
| 772 | struct inode *inode; |
| 773 | struct inode *lower_inode; |
| 774 | struct path lower_path; |
| 775 | struct dentry *parent; |
Daniel Rosenberg | 5080d24 | 2016-05-18 16:57:10 -0700 | [diff] [blame] | 776 | int err; |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 777 | |
| 778 | parent = dget_parent(dentry); |
Daniel Rosenberg | 497ac90 | 2016-02-03 21:08:21 -0800 | [diff] [blame] | 779 | if(!check_caller_access_to_name(d_inode(parent), dentry->d_name.name)) { |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 780 | printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n" |
| 781 | " dentry: %s, task:%s\n", |
| 782 | __func__, dentry->d_name.name, current->comm); |
| 783 | dput(parent); |
| 784 | return -EACCES; |
| 785 | } |
| 786 | dput(parent); |
| 787 | |
| 788 | inode = d_inode(dentry); |
| 789 | |
| 790 | sdcardfs_get_lower_path(dentry, &lower_path); |
| 791 | lower_dentry = lower_path.dentry; |
| 792 | lower_inode = sdcardfs_lower_inode(inode); |
| 793 | |
Daniel Rosenberg | 497ac90 | 2016-02-03 21:08:21 -0800 | [diff] [blame] | 794 | sdcardfs_copy_and_fix_attrs(inode, lower_inode); |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 795 | fsstack_copy_inode_size(inode, lower_inode); |
Daniel Rosenberg | 497ac90 | 2016-02-03 21:08:21 -0800 | [diff] [blame] | 796 | |
Daniel Rosenberg | 5080d24 | 2016-05-18 16:57:10 -0700 | [diff] [blame] | 797 | err = sdcardfs_fillattr(inode, stat); |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 798 | sdcardfs_put_lower_path(dentry, &lower_path); |
Daniel Rosenberg | 5080d24 | 2016-05-18 16:57:10 -0700 | [diff] [blame] | 799 | return err; |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 800 | } |
| 801 | |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 802 | const struct inode_operations sdcardfs_symlink_iops = { |
| 803 | .permission = sdcardfs_permission, |
| 804 | .setattr = sdcardfs_setattr, |
| 805 | /* XXX Following operations are implemented, |
| 806 | * but FUSE(sdcard) or FAT does not support them |
| 807 | * These methods are *NOT* perfectly tested. |
| 808 | .readlink = sdcardfs_readlink, |
| 809 | .follow_link = sdcardfs_follow_link, |
Daniel Campello | d1d080c | 2015-07-20 16:27:37 -0700 | [diff] [blame] | 810 | .put_link = kfree_put_link, |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 811 | */ |
| 812 | }; |
| 813 | |
| 814 | const struct inode_operations sdcardfs_dir_iops = { |
| 815 | .create = sdcardfs_create, |
| 816 | .lookup = sdcardfs_lookup, |
| 817 | .permission = sdcardfs_permission, |
Daniel Campello | 35c9e24 | 2015-07-20 16:23:50 -0700 | [diff] [blame] | 818 | .unlink = sdcardfs_unlink, |
| 819 | .mkdir = sdcardfs_mkdir, |
| 820 | .rmdir = sdcardfs_rmdir, |
| 821 | .rename = sdcardfs_rename, |
| 822 | .setattr = sdcardfs_setattr, |
| 823 | .getattr = sdcardfs_getattr, |
| 824 | /* XXX Following operations are implemented, |
| 825 | * but FUSE(sdcard) or FAT does not support them |
| 826 | * These methods are *NOT* perfectly tested. |
| 827 | .symlink = sdcardfs_symlink, |
| 828 | .link = sdcardfs_link, |
| 829 | .mknod = sdcardfs_mknod, |
| 830 | */ |
| 831 | }; |
| 832 | |
| 833 | const struct inode_operations sdcardfs_main_iops = { |
| 834 | .permission = sdcardfs_permission, |
| 835 | .setattr = sdcardfs_setattr, |
| 836 | .getattr = sdcardfs_getattr, |
| 837 | }; |