1d2912cb1SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 2e9be9d5eSMiklos Szeredi /* 3e9be9d5eSMiklos Szeredi * 4e9be9d5eSMiklos Szeredi * Copyright (C) 2011 Novell Inc. 5e9be9d5eSMiklos Szeredi */ 6e9be9d5eSMiklos Szeredi 7fb5bb2c3SDavid Howells #include <linux/module.h> 8e9be9d5eSMiklos Szeredi #include <linux/fs.h> 9e9be9d5eSMiklos Szeredi #include <linux/slab.h> 10e9be9d5eSMiklos Szeredi #include <linux/file.h> 11e9be9d5eSMiklos Szeredi #include <linux/splice.h> 12e9be9d5eSMiklos Szeredi #include <linux/xattr.h> 13e9be9d5eSMiklos Szeredi #include <linux/security.h> 14e9be9d5eSMiklos Szeredi #include <linux/uaccess.h> 15174cd4b1SIngo Molnar #include <linux/sched/signal.h> 165b825c3aSIngo Molnar #include <linux/cred.h> 17e9be9d5eSMiklos Szeredi #include <linux/namei.h> 18fb5bb2c3SDavid Howells #include <linux/fdtable.h> 19fb5bb2c3SDavid Howells #include <linux/ratelimit.h> 203a1e819bSAmir Goldstein #include <linux/exportfs.h> 21e9be9d5eSMiklos Szeredi #include "overlayfs.h" 22e9be9d5eSMiklos Szeredi 23e9be9d5eSMiklos Szeredi #define OVL_COPY_UP_CHUNK_SIZE (1 << 20) 24e9be9d5eSMiklos Szeredi 25670c2324SMiklos Szeredi static int ovl_ccup_set(const char *buf, const struct kernel_param *param) 26fb5bb2c3SDavid Howells { 27670c2324SMiklos Szeredi pr_warn("overlayfs: \"check_copy_up\" module option is obsolete\n"); 28fb5bb2c3SDavid Howells return 0; 29fb5bb2c3SDavid Howells } 30fb5bb2c3SDavid Howells 31670c2324SMiklos Szeredi static int ovl_ccup_get(char *buf, const struct kernel_param *param) 32fb5bb2c3SDavid Howells { 33670c2324SMiklos Szeredi return sprintf(buf, "N\n"); 34fb5bb2c3SDavid Howells } 35fb5bb2c3SDavid Howells 36670c2324SMiklos Szeredi module_param_call(check_copy_up, ovl_ccup_set, ovl_ccup_get, NULL, 0644); 37670c2324SMiklos Szeredi MODULE_PARM_DESC(ovl_check_copy_up, "Obsolete; does nothing"); 38670c2324SMiklos Szeredi 39e9be9d5eSMiklos Szeredi int ovl_copy_xattr(struct dentry *old, struct dentry *new) 40e9be9d5eSMiklos Szeredi { 41e4ad29faSVito Caputo ssize_t list_size, size, value_size = 0; 42e4ad29faSVito Caputo char *buf, *name, *value = NULL; 43e4ad29faSVito Caputo int uninitialized_var(error); 448b326c61SMiklos Szeredi size_t slen; 45e9be9d5eSMiklos Szeredi 465d6c3191SAndreas Gruenbacher if (!(old->d_inode->i_opflags & IOP_XATTR) || 475d6c3191SAndreas Gruenbacher !(new->d_inode->i_opflags & IOP_XATTR)) 48e9be9d5eSMiklos Szeredi return 0; 49e9be9d5eSMiklos Szeredi 50e9be9d5eSMiklos Szeredi list_size = vfs_listxattr(old, NULL, 0); 51e9be9d5eSMiklos Szeredi if (list_size <= 0) { 52e9be9d5eSMiklos Szeredi if (list_size == -EOPNOTSUPP) 53e9be9d5eSMiklos Szeredi return 0; 54e9be9d5eSMiklos Szeredi return list_size; 55e9be9d5eSMiklos Szeredi } 56e9be9d5eSMiklos Szeredi 57e9be9d5eSMiklos Szeredi buf = kzalloc(list_size, GFP_KERNEL); 58e9be9d5eSMiklos Szeredi if (!buf) 59e9be9d5eSMiklos Szeredi return -ENOMEM; 60e9be9d5eSMiklos Szeredi 61e9be9d5eSMiklos Szeredi list_size = vfs_listxattr(old, buf, list_size); 62e9be9d5eSMiklos Szeredi if (list_size <= 0) { 63e9be9d5eSMiklos Szeredi error = list_size; 64e4ad29faSVito Caputo goto out; 65e9be9d5eSMiklos Szeredi } 66e9be9d5eSMiklos Szeredi 678b326c61SMiklos Szeredi for (name = buf; list_size; name += slen) { 688b326c61SMiklos Szeredi slen = strnlen(name, list_size) + 1; 698b326c61SMiklos Szeredi 708b326c61SMiklos Szeredi /* underlying fs providing us with an broken xattr list? */ 718b326c61SMiklos Szeredi if (WARN_ON(slen > list_size)) { 728b326c61SMiklos Szeredi error = -EIO; 738b326c61SMiklos Szeredi break; 748b326c61SMiklos Szeredi } 758b326c61SMiklos Szeredi list_size -= slen; 768b326c61SMiklos Szeredi 770956254aSMiklos Szeredi if (ovl_is_private_xattr(name)) 780956254aSMiklos Szeredi continue; 79e4ad29faSVito Caputo retry: 80e4ad29faSVito Caputo size = vfs_getxattr(old, name, value, value_size); 81e4ad29faSVito Caputo if (size == -ERANGE) 82e4ad29faSVito Caputo size = vfs_getxattr(old, name, NULL, 0); 83e4ad29faSVito Caputo 8497daf8b9SMiklos Szeredi if (size < 0) { 85e9be9d5eSMiklos Szeredi error = size; 86e4ad29faSVito Caputo break; 87e9be9d5eSMiklos Szeredi } 88e9be9d5eSMiklos Szeredi 89e4ad29faSVito Caputo if (size > value_size) { 90e4ad29faSVito Caputo void *new; 91e4ad29faSVito Caputo 92e4ad29faSVito Caputo new = krealloc(value, size, GFP_KERNEL); 93e4ad29faSVito Caputo if (!new) { 94e4ad29faSVito Caputo error = -ENOMEM; 95e4ad29faSVito Caputo break; 96e4ad29faSVito Caputo } 97e4ad29faSVito Caputo value = new; 98e4ad29faSVito Caputo value_size = size; 99e4ad29faSVito Caputo goto retry; 100e4ad29faSVito Caputo } 101e4ad29faSVito Caputo 102121ab822SVivek Goyal error = security_inode_copy_up_xattr(name); 103121ab822SVivek Goyal if (error < 0 && error != -EOPNOTSUPP) 104121ab822SVivek Goyal break; 105121ab822SVivek Goyal if (error == 1) { 106121ab822SVivek Goyal error = 0; 107121ab822SVivek Goyal continue; /* Discard */ 108121ab822SVivek Goyal } 109e4ad29faSVito Caputo error = vfs_setxattr(new, name, value, size, 0); 110e4ad29faSVito Caputo if (error) 111e4ad29faSVito Caputo break; 112e4ad29faSVito Caputo } 113e9be9d5eSMiklos Szeredi kfree(value); 114e9be9d5eSMiklos Szeredi out: 115e9be9d5eSMiklos Szeredi kfree(buf); 116e9be9d5eSMiklos Szeredi return error; 117e9be9d5eSMiklos Szeredi } 118e9be9d5eSMiklos Szeredi 119e9be9d5eSMiklos Szeredi static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len) 120e9be9d5eSMiklos Szeredi { 121e9be9d5eSMiklos Szeredi struct file *old_file; 122e9be9d5eSMiklos Szeredi struct file *new_file; 123e9be9d5eSMiklos Szeredi loff_t old_pos = 0; 124e9be9d5eSMiklos Szeredi loff_t new_pos = 0; 12542ec3d4cSDarrick J. Wong loff_t cloned; 126e9be9d5eSMiklos Szeredi int error = 0; 127e9be9d5eSMiklos Szeredi 128e9be9d5eSMiklos Szeredi if (len == 0) 129e9be9d5eSMiklos Szeredi return 0; 130e9be9d5eSMiklos Szeredi 1310480334fSDavid Howells old_file = ovl_path_open(old, O_LARGEFILE | O_RDONLY); 132e9be9d5eSMiklos Szeredi if (IS_ERR(old_file)) 133e9be9d5eSMiklos Szeredi return PTR_ERR(old_file); 134e9be9d5eSMiklos Szeredi 1350480334fSDavid Howells new_file = ovl_path_open(new, O_LARGEFILE | O_WRONLY); 136e9be9d5eSMiklos Szeredi if (IS_ERR(new_file)) { 137e9be9d5eSMiklos Szeredi error = PTR_ERR(new_file); 138e9be9d5eSMiklos Szeredi goto out_fput; 139e9be9d5eSMiklos Szeredi } 140e9be9d5eSMiklos Szeredi 1412ea98466SAmir Goldstein /* Try to use clone_file_range to clone up within the same fs */ 142452ce659SDarrick J. Wong cloned = do_clone_file_range(old_file, 0, new_file, 0, len, 0); 14342ec3d4cSDarrick J. Wong if (cloned == len) 1442ea98466SAmir Goldstein goto out; 1452ea98466SAmir Goldstein /* Couldn't clone, so now we try to copy the data */ 1462ea98466SAmir Goldstein 147e9be9d5eSMiklos Szeredi /* FIXME: copy up sparse files efficiently */ 148e9be9d5eSMiklos Szeredi while (len) { 149e9be9d5eSMiklos Szeredi size_t this_len = OVL_COPY_UP_CHUNK_SIZE; 150e9be9d5eSMiklos Szeredi long bytes; 151e9be9d5eSMiklos Szeredi 152e9be9d5eSMiklos Szeredi if (len < this_len) 153e9be9d5eSMiklos Szeredi this_len = len; 154e9be9d5eSMiklos Szeredi 155e9be9d5eSMiklos Szeredi if (signal_pending_state(TASK_KILLABLE, current)) { 156e9be9d5eSMiklos Szeredi error = -EINTR; 157e9be9d5eSMiklos Szeredi break; 158e9be9d5eSMiklos Szeredi } 159e9be9d5eSMiklos Szeredi 160e9be9d5eSMiklos Szeredi bytes = do_splice_direct(old_file, &old_pos, 161e9be9d5eSMiklos Szeredi new_file, &new_pos, 162e9be9d5eSMiklos Szeredi this_len, SPLICE_F_MOVE); 163e9be9d5eSMiklos Szeredi if (bytes <= 0) { 164e9be9d5eSMiklos Szeredi error = bytes; 165e9be9d5eSMiklos Szeredi break; 166e9be9d5eSMiklos Szeredi } 167e9be9d5eSMiklos Szeredi WARN_ON(old_pos != new_pos); 168e9be9d5eSMiklos Szeredi 169e9be9d5eSMiklos Szeredi len -= bytes; 170e9be9d5eSMiklos Szeredi } 1712ea98466SAmir Goldstein out: 172641089c1SMiklos Szeredi if (!error) 173641089c1SMiklos Szeredi error = vfs_fsync(new_file, 0); 174e9be9d5eSMiklos Szeredi fput(new_file); 175e9be9d5eSMiklos Szeredi out_fput: 176e9be9d5eSMiklos Szeredi fput(old_file); 177e9be9d5eSMiklos Szeredi return error; 178e9be9d5eSMiklos Szeredi } 179e9be9d5eSMiklos Szeredi 1800c288874SVivek Goyal static int ovl_set_size(struct dentry *upperdentry, struct kstat *stat) 1810c288874SVivek Goyal { 1820c288874SVivek Goyal struct iattr attr = { 1830c288874SVivek Goyal .ia_valid = ATTR_SIZE, 1840c288874SVivek Goyal .ia_size = stat->size, 1850c288874SVivek Goyal }; 1860c288874SVivek Goyal 1870c288874SVivek Goyal return notify_change(upperdentry, &attr, NULL); 1880c288874SVivek Goyal } 1890c288874SVivek Goyal 190e9be9d5eSMiklos Szeredi static int ovl_set_timestamps(struct dentry *upperdentry, struct kstat *stat) 191e9be9d5eSMiklos Szeredi { 192e9be9d5eSMiklos Szeredi struct iattr attr = { 193e9be9d5eSMiklos Szeredi .ia_valid = 194e9be9d5eSMiklos Szeredi ATTR_ATIME | ATTR_MTIME | ATTR_ATIME_SET | ATTR_MTIME_SET, 195e9be9d5eSMiklos Szeredi .ia_atime = stat->atime, 196e9be9d5eSMiklos Szeredi .ia_mtime = stat->mtime, 197e9be9d5eSMiklos Szeredi }; 198e9be9d5eSMiklos Szeredi 199e9be9d5eSMiklos Szeredi return notify_change(upperdentry, &attr, NULL); 200e9be9d5eSMiklos Szeredi } 201e9be9d5eSMiklos Szeredi 202e9be9d5eSMiklos Szeredi int ovl_set_attr(struct dentry *upperdentry, struct kstat *stat) 203e9be9d5eSMiklos Szeredi { 204e9be9d5eSMiklos Szeredi int err = 0; 205e9be9d5eSMiklos Szeredi 206e9be9d5eSMiklos Szeredi if (!S_ISLNK(stat->mode)) { 207e9be9d5eSMiklos Szeredi struct iattr attr = { 208e9be9d5eSMiklos Szeredi .ia_valid = ATTR_MODE, 209e9be9d5eSMiklos Szeredi .ia_mode = stat->mode, 210e9be9d5eSMiklos Szeredi }; 211e9be9d5eSMiklos Szeredi err = notify_change(upperdentry, &attr, NULL); 212e9be9d5eSMiklos Szeredi } 213e9be9d5eSMiklos Szeredi if (!err) { 214e9be9d5eSMiklos Szeredi struct iattr attr = { 215e9be9d5eSMiklos Szeredi .ia_valid = ATTR_UID | ATTR_GID, 216e9be9d5eSMiklos Szeredi .ia_uid = stat->uid, 217e9be9d5eSMiklos Szeredi .ia_gid = stat->gid, 218e9be9d5eSMiklos Szeredi }; 219e9be9d5eSMiklos Szeredi err = notify_change(upperdentry, &attr, NULL); 220e9be9d5eSMiklos Szeredi } 221e9be9d5eSMiklos Szeredi if (!err) 222e9be9d5eSMiklos Szeredi ovl_set_timestamps(upperdentry, stat); 223e9be9d5eSMiklos Szeredi 224e9be9d5eSMiklos Szeredi return err; 225e9be9d5eSMiklos Szeredi } 226e9be9d5eSMiklos Szeredi 2275b2cccd3SAmir Goldstein struct ovl_fh *ovl_encode_real_fh(struct dentry *real, bool is_upper) 2283a1e819bSAmir Goldstein { 2293a1e819bSAmir Goldstein struct ovl_fh *fh; 2303a1e819bSAmir Goldstein int fh_type, fh_len, dwords; 2313a1e819bSAmir Goldstein void *buf; 2323a1e819bSAmir Goldstein int buflen = MAX_HANDLE_SZ; 23305122443SAmir Goldstein uuid_t *uuid = &real->d_sb->s_uuid; 2343a1e819bSAmir Goldstein 2350ee931c4SMichal Hocko buf = kmalloc(buflen, GFP_KERNEL); 2363a1e819bSAmir Goldstein if (!buf) 2373a1e819bSAmir Goldstein return ERR_PTR(-ENOMEM); 2383a1e819bSAmir Goldstein 2393a1e819bSAmir Goldstein /* 2403a1e819bSAmir Goldstein * We encode a non-connectable file handle for non-dir, because we 2413a1e819bSAmir Goldstein * only need to find the lower inode number and we don't want to pay 2423a1e819bSAmir Goldstein * the price or reconnecting the dentry. 2433a1e819bSAmir Goldstein */ 2443a1e819bSAmir Goldstein dwords = buflen >> 2; 24505122443SAmir Goldstein fh_type = exportfs_encode_fh(real, buf, &dwords, 0); 2463a1e819bSAmir Goldstein buflen = (dwords << 2); 2473a1e819bSAmir Goldstein 2483a1e819bSAmir Goldstein fh = ERR_PTR(-EIO); 2493a1e819bSAmir Goldstein if (WARN_ON(fh_type < 0) || 2503a1e819bSAmir Goldstein WARN_ON(buflen > MAX_HANDLE_SZ) || 2513a1e819bSAmir Goldstein WARN_ON(fh_type == FILEID_INVALID)) 2523a1e819bSAmir Goldstein goto out; 2533a1e819bSAmir Goldstein 2543a1e819bSAmir Goldstein BUILD_BUG_ON(MAX_HANDLE_SZ + offsetof(struct ovl_fh, fid) > 255); 2553a1e819bSAmir Goldstein fh_len = offsetof(struct ovl_fh, fid) + buflen; 2563a1e819bSAmir Goldstein fh = kmalloc(fh_len, GFP_KERNEL); 2573a1e819bSAmir Goldstein if (!fh) { 2583a1e819bSAmir Goldstein fh = ERR_PTR(-ENOMEM); 2593a1e819bSAmir Goldstein goto out; 2603a1e819bSAmir Goldstein } 2613a1e819bSAmir Goldstein 2623a1e819bSAmir Goldstein fh->version = OVL_FH_VERSION; 2633a1e819bSAmir Goldstein fh->magic = OVL_FH_MAGIC; 2643a1e819bSAmir Goldstein fh->type = fh_type; 2653a1e819bSAmir Goldstein fh->flags = OVL_FH_FLAG_CPU_ENDIAN; 26654fb347eSAmir Goldstein /* 26754fb347eSAmir Goldstein * When we will want to decode an overlay dentry from this handle 26854fb347eSAmir Goldstein * and all layers are on the same fs, if we get a disconncted real 26954fb347eSAmir Goldstein * dentry when we decode fid, the only way to tell if we should assign 27054fb347eSAmir Goldstein * it to upperdentry or to lowerstack is by checking this flag. 27154fb347eSAmir Goldstein */ 27254fb347eSAmir Goldstein if (is_upper) 27354fb347eSAmir Goldstein fh->flags |= OVL_FH_FLAG_PATH_UPPER; 2743a1e819bSAmir Goldstein fh->len = fh_len; 2753a1e819bSAmir Goldstein fh->uuid = *uuid; 2763a1e819bSAmir Goldstein memcpy(fh->fid, buf, buflen); 2773a1e819bSAmir Goldstein 2783a1e819bSAmir Goldstein out: 2793a1e819bSAmir Goldstein kfree(buf); 2803a1e819bSAmir Goldstein return fh; 2813a1e819bSAmir Goldstein } 2823a1e819bSAmir Goldstein 2839678e630SAmir Goldstein int ovl_set_origin(struct dentry *dentry, struct dentry *lower, 2843a1e819bSAmir Goldstein struct dentry *upper) 2853a1e819bSAmir Goldstein { 2863a1e819bSAmir Goldstein const struct ovl_fh *fh = NULL; 2873a1e819bSAmir Goldstein int err; 2883a1e819bSAmir Goldstein 2893a1e819bSAmir Goldstein /* 2903a1e819bSAmir Goldstein * When lower layer doesn't support export operations store a 'null' fh, 2913a1e819bSAmir Goldstein * so we can use the overlay.origin xattr to distignuish between a copy 2923a1e819bSAmir Goldstein * up and a pure upper inode. 2933a1e819bSAmir Goldstein */ 29402bcd157SAmir Goldstein if (ovl_can_decode_fh(lower->d_sb)) { 2955b2cccd3SAmir Goldstein fh = ovl_encode_real_fh(lower, false); 2963a1e819bSAmir Goldstein if (IS_ERR(fh)) 2973a1e819bSAmir Goldstein return PTR_ERR(fh); 2983a1e819bSAmir Goldstein } 2993a1e819bSAmir Goldstein 3006266d465SMiklos Szeredi /* 3016266d465SMiklos Szeredi * Do not fail when upper doesn't support xattrs. 3026266d465SMiklos Szeredi */ 3036266d465SMiklos Szeredi err = ovl_check_setxattr(dentry, upper, OVL_XATTR_ORIGIN, fh, 3046266d465SMiklos Szeredi fh ? fh->len : 0, 0); 3053a1e819bSAmir Goldstein kfree(fh); 3063a1e819bSAmir Goldstein 3073a1e819bSAmir Goldstein return err; 3083a1e819bSAmir Goldstein } 3093a1e819bSAmir Goldstein 310016b720fSAmir Goldstein /* Store file handle of @upper dir in @index dir entry */ 311016b720fSAmir Goldstein static int ovl_set_upper_fh(struct dentry *upper, struct dentry *index) 312016b720fSAmir Goldstein { 313016b720fSAmir Goldstein const struct ovl_fh *fh; 314016b720fSAmir Goldstein int err; 315016b720fSAmir Goldstein 3165b2cccd3SAmir Goldstein fh = ovl_encode_real_fh(upper, true); 317016b720fSAmir Goldstein if (IS_ERR(fh)) 318016b720fSAmir Goldstein return PTR_ERR(fh); 319016b720fSAmir Goldstein 320016b720fSAmir Goldstein err = ovl_do_setxattr(index, OVL_XATTR_UPPER, fh, fh->len, 0); 321016b720fSAmir Goldstein 322016b720fSAmir Goldstein kfree(fh); 323016b720fSAmir Goldstein return err; 324016b720fSAmir Goldstein } 325016b720fSAmir Goldstein 326016b720fSAmir Goldstein /* 327016b720fSAmir Goldstein * Create and install index entry. 328016b720fSAmir Goldstein * 329016b720fSAmir Goldstein * Caller must hold i_mutex on indexdir. 330016b720fSAmir Goldstein */ 331016b720fSAmir Goldstein static int ovl_create_index(struct dentry *dentry, struct dentry *origin, 332016b720fSAmir Goldstein struct dentry *upper) 333016b720fSAmir Goldstein { 334016b720fSAmir Goldstein struct dentry *indexdir = ovl_indexdir(dentry->d_sb); 335016b720fSAmir Goldstein struct inode *dir = d_inode(indexdir); 336016b720fSAmir Goldstein struct dentry *index = NULL; 337016b720fSAmir Goldstein struct dentry *temp = NULL; 338016b720fSAmir Goldstein struct qstr name = { }; 339016b720fSAmir Goldstein int err; 340016b720fSAmir Goldstein 341016b720fSAmir Goldstein /* 342016b720fSAmir Goldstein * For now this is only used for creating index entry for directories, 343016b720fSAmir Goldstein * because non-dir are copied up directly to index and then hardlinked 344016b720fSAmir Goldstein * to upper dir. 345016b720fSAmir Goldstein * 346016b720fSAmir Goldstein * TODO: implement create index for non-dir, so we can call it when 347016b720fSAmir Goldstein * encoding file handle for non-dir in case index does not exist. 348016b720fSAmir Goldstein */ 349016b720fSAmir Goldstein if (WARN_ON(!d_is_dir(dentry))) 350016b720fSAmir Goldstein return -EIO; 351016b720fSAmir Goldstein 352016b720fSAmir Goldstein /* Directory not expected to be indexed before copy up */ 353016b720fSAmir Goldstein if (WARN_ON(ovl_test_flag(OVL_INDEX, d_inode(dentry)))) 354016b720fSAmir Goldstein return -EIO; 355016b720fSAmir Goldstein 356016b720fSAmir Goldstein err = ovl_get_index_name(origin, &name); 357016b720fSAmir Goldstein if (err) 358016b720fSAmir Goldstein return err; 359016b720fSAmir Goldstein 360137ec526SAmir Goldstein temp = ovl_create_temp(indexdir, OVL_CATTR(S_IFDIR | 0)); 361b148cba4SMiklos Szeredi err = PTR_ERR(temp); 362016b720fSAmir Goldstein if (IS_ERR(temp)) 363b148cba4SMiklos Szeredi goto free_name; 364016b720fSAmir Goldstein 365016b720fSAmir Goldstein err = ovl_set_upper_fh(upper, temp); 366016b720fSAmir Goldstein if (err) 367b148cba4SMiklos Szeredi goto out; 368016b720fSAmir Goldstein 369016b720fSAmir Goldstein index = lookup_one_len(name.name, indexdir, name.len); 370016b720fSAmir Goldstein if (IS_ERR(index)) { 371016b720fSAmir Goldstein err = PTR_ERR(index); 372016b720fSAmir Goldstein } else { 373016b720fSAmir Goldstein err = ovl_do_rename(dir, temp, dir, index, 0); 374016b720fSAmir Goldstein dput(index); 375016b720fSAmir Goldstein } 376016b720fSAmir Goldstein out: 377b148cba4SMiklos Szeredi if (err) 378b148cba4SMiklos Szeredi ovl_cleanup(dir, temp); 379016b720fSAmir Goldstein dput(temp); 380b148cba4SMiklos Szeredi free_name: 381016b720fSAmir Goldstein kfree(name.name); 382016b720fSAmir Goldstein return err; 383016b720fSAmir Goldstein } 384016b720fSAmir Goldstein 38523f0ab13SMiklos Szeredi struct ovl_copy_up_ctx { 386a6fb235aSMiklos Szeredi struct dentry *parent; 38723f0ab13SMiklos Szeredi struct dentry *dentry; 38823f0ab13SMiklos Szeredi struct path lowerpath; 38923f0ab13SMiklos Szeredi struct kstat stat; 39023f0ab13SMiklos Szeredi struct kstat pstat; 39123f0ab13SMiklos Szeredi const char *link; 39259be0971SAmir Goldstein struct dentry *destdir; 39359be0971SAmir Goldstein struct qstr destname; 39423f0ab13SMiklos Szeredi struct dentry *workdir; 39559be0971SAmir Goldstein bool origin; 396016b720fSAmir Goldstein bool indexed; 39744d5bf10SVivek Goyal bool metacopy; 39823f0ab13SMiklos Szeredi }; 39923f0ab13SMiklos Szeredi 400f4439de1SAmir Goldstein static int ovl_link_up(struct ovl_copy_up_ctx *c) 401f4439de1SAmir Goldstein { 402f4439de1SAmir Goldstein int err; 403f4439de1SAmir Goldstein struct dentry *upper; 404f4439de1SAmir Goldstein struct dentry *upperdir = ovl_dentry_upper(c->parent); 405f4439de1SAmir Goldstein struct inode *udir = d_inode(upperdir); 406f4439de1SAmir Goldstein 407f4439de1SAmir Goldstein /* Mark parent "impure" because it may now contain non-pure upper */ 408f4439de1SAmir Goldstein err = ovl_set_impure(c->parent, upperdir); 409f4439de1SAmir Goldstein if (err) 410f4439de1SAmir Goldstein return err; 411f4439de1SAmir Goldstein 412f4439de1SAmir Goldstein err = ovl_set_nlink_lower(c->dentry); 413f4439de1SAmir Goldstein if (err) 414f4439de1SAmir Goldstein return err; 415f4439de1SAmir Goldstein 416f4439de1SAmir Goldstein inode_lock_nested(udir, I_MUTEX_PARENT); 417f4439de1SAmir Goldstein upper = lookup_one_len(c->dentry->d_name.name, upperdir, 418f4439de1SAmir Goldstein c->dentry->d_name.len); 419f4439de1SAmir Goldstein err = PTR_ERR(upper); 420f4439de1SAmir Goldstein if (!IS_ERR(upper)) { 4216cf00764SAmir Goldstein err = ovl_do_link(ovl_dentry_upper(c->dentry), udir, upper); 422f4439de1SAmir Goldstein dput(upper); 423f4439de1SAmir Goldstein 424f4439de1SAmir Goldstein if (!err) { 425f4439de1SAmir Goldstein /* Restore timestamps on parent (best effort) */ 426f4439de1SAmir Goldstein ovl_set_timestamps(upperdir, &c->pstat); 427f4439de1SAmir Goldstein ovl_dentry_set_upper_alias(c->dentry); 428f4439de1SAmir Goldstein } 429f4439de1SAmir Goldstein } 430f4439de1SAmir Goldstein inode_unlock(udir); 431aa3ff3c1SAmir Goldstein if (err) 432aa3ff3c1SAmir Goldstein return err; 433aa3ff3c1SAmir Goldstein 434aa3ff3c1SAmir Goldstein err = ovl_set_nlink_upper(c->dentry); 435f4439de1SAmir Goldstein 436f4439de1SAmir Goldstein return err; 437f4439de1SAmir Goldstein } 438f4439de1SAmir Goldstein 43923f0ab13SMiklos Szeredi static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp) 44002209d10SAmir Goldstein { 44102209d10SAmir Goldstein int err; 44202209d10SAmir Goldstein 4435f32879eSVivek Goyal /* 4445f32879eSVivek Goyal * Copy up data first and then xattrs. Writing data after 4455f32879eSVivek Goyal * xattrs will remove security.capability xattr automatically. 4465f32879eSVivek Goyal */ 4475f32879eSVivek Goyal if (S_ISREG(c->stat.mode) && !c->metacopy) { 4485f32879eSVivek Goyal struct path upperpath, datapath; 4495f32879eSVivek Goyal 4505f32879eSVivek Goyal ovl_path_upper(c->dentry, &upperpath); 4515f32879eSVivek Goyal if (WARN_ON(upperpath.dentry != NULL)) 4525f32879eSVivek Goyal return -EIO; 4535f32879eSVivek Goyal upperpath.dentry = temp; 4545f32879eSVivek Goyal 4555f32879eSVivek Goyal ovl_path_lowerdata(c->dentry, &datapath); 4565f32879eSVivek Goyal err = ovl_copy_up_data(&datapath, &upperpath, c->stat.size); 4575f32879eSVivek Goyal if (err) 4585f32879eSVivek Goyal return err; 4595f32879eSVivek Goyal } 4605f32879eSVivek Goyal 46123f0ab13SMiklos Szeredi err = ovl_copy_xattr(c->lowerpath.dentry, temp); 46202209d10SAmir Goldstein if (err) 46302209d10SAmir Goldstein return err; 46402209d10SAmir Goldstein 46502209d10SAmir Goldstein /* 46602209d10SAmir Goldstein * Store identifier of lower inode in upper inode xattr to 46702209d10SAmir Goldstein * allow lookup of the copy up origin inode. 46802209d10SAmir Goldstein * 46902209d10SAmir Goldstein * Don't set origin when we are breaking the association with a lower 47002209d10SAmir Goldstein * hard link. 47102209d10SAmir Goldstein */ 47259be0971SAmir Goldstein if (c->origin) { 47323f0ab13SMiklos Szeredi err = ovl_set_origin(c->dentry, c->lowerpath.dentry, temp); 47402209d10SAmir Goldstein if (err) 47502209d10SAmir Goldstein return err; 47602209d10SAmir Goldstein } 47702209d10SAmir Goldstein 4780c288874SVivek Goyal if (c->metacopy) { 4790c288874SVivek Goyal err = ovl_check_setxattr(c->dentry, temp, OVL_XATTR_METACOPY, 4800c288874SVivek Goyal NULL, 0, -EOPNOTSUPP); 4810c288874SVivek Goyal if (err) 4820c288874SVivek Goyal return err; 4830c288874SVivek Goyal } 4840c288874SVivek Goyal 485bd64e575SVivek Goyal inode_lock(temp->d_inode); 4860c288874SVivek Goyal if (c->metacopy) 4870c288874SVivek Goyal err = ovl_set_size(temp, &c->stat); 4880c288874SVivek Goyal if (!err) 489bd64e575SVivek Goyal err = ovl_set_attr(temp, &c->stat); 490bd64e575SVivek Goyal inode_unlock(temp->d_inode); 491bd64e575SVivek Goyal 492bd64e575SVivek Goyal return err; 49302209d10SAmir Goldstein } 49402209d10SAmir Goldstein 4956b52243fSMiklos Szeredi struct ovl_cu_creds { 4966b52243fSMiklos Szeredi const struct cred *old; 4976b52243fSMiklos Szeredi struct cred *new; 498b10cdcdcSAmir Goldstein }; 499b10cdcdcSAmir Goldstein 5006b52243fSMiklos Szeredi static int ovl_prep_cu_creds(struct dentry *dentry, struct ovl_cu_creds *cc) 501b10cdcdcSAmir Goldstein { 502b10cdcdcSAmir Goldstein int err; 503b10cdcdcSAmir Goldstein 5046b52243fSMiklos Szeredi cc->old = cc->new = NULL; 5056b52243fSMiklos Szeredi err = security_inode_copy_up(dentry, &cc->new); 5066b52243fSMiklos Szeredi if (err < 0) 507b10cdcdcSAmir Goldstein return err; 5086b52243fSMiklos Szeredi 5096b52243fSMiklos Szeredi if (cc->new) 5106b52243fSMiklos Szeredi cc->old = override_creds(cc->new); 5116b52243fSMiklos Szeredi 5126b52243fSMiklos Szeredi return 0; 5136b52243fSMiklos Szeredi } 5146b52243fSMiklos Szeredi 5156b52243fSMiklos Szeredi static void ovl_revert_cu_creds(struct ovl_cu_creds *cc) 5166b52243fSMiklos Szeredi { 5176b52243fSMiklos Szeredi if (cc->new) { 5186b52243fSMiklos Szeredi revert_creds(cc->old); 5196b52243fSMiklos Szeredi put_cred(cc->new); 5206b52243fSMiklos Szeredi } 521b10cdcdcSAmir Goldstein } 522b10cdcdcSAmir Goldstein 523b10cdcdcSAmir Goldstein /* 524b10cdcdcSAmir Goldstein * Copyup using workdir to prepare temp file. Used when copying up directories, 525b10cdcdcSAmir Goldstein * special files or when upper fs doesn't support O_TMPFILE. 526b10cdcdcSAmir Goldstein */ 527b10cdcdcSAmir Goldstein static int ovl_copy_up_workdir(struct ovl_copy_up_ctx *c) 528b10cdcdcSAmir Goldstein { 529b79e05aaSAmir Goldstein struct inode *inode; 5306b52243fSMiklos Szeredi struct inode *udir = d_inode(c->destdir), *wdir = d_inode(c->workdir); 5316b52243fSMiklos Szeredi struct dentry *temp, *upper; 5326b52243fSMiklos Szeredi struct ovl_cu_creds cc; 5337d90b853SMiklos Szeredi int err; 5346b52243fSMiklos Szeredi struct ovl_cattr cattr = { 5356b52243fSMiklos Szeredi /* Can't properly set mode on creation because of the umask */ 5366b52243fSMiklos Szeredi .mode = c->stat.mode & S_IFMT, 5376b52243fSMiklos Szeredi .rdev = c->stat.rdev, 5386b52243fSMiklos Szeredi .link = c->link 5396b52243fSMiklos Szeredi }; 5407d90b853SMiklos Szeredi 541b10cdcdcSAmir Goldstein err = ovl_lock_rename_workdir(c->workdir, c->destdir); 542b10cdcdcSAmir Goldstein if (err) 543b10cdcdcSAmir Goldstein return err; 544b10cdcdcSAmir Goldstein 5456b52243fSMiklos Szeredi err = ovl_prep_cu_creds(c->dentry, &cc); 5466b52243fSMiklos Szeredi if (err) 5476b52243fSMiklos Szeredi goto unlock; 5486b52243fSMiklos Szeredi 5496b52243fSMiklos Szeredi temp = ovl_create_temp(c->workdir, &cattr); 5506b52243fSMiklos Szeredi ovl_revert_cu_creds(&cc); 5516b52243fSMiklos Szeredi 552b10cdcdcSAmir Goldstein err = PTR_ERR(temp); 553b10cdcdcSAmir Goldstein if (IS_ERR(temp)) 554b10cdcdcSAmir Goldstein goto unlock; 555b10cdcdcSAmir Goldstein 556b10cdcdcSAmir Goldstein err = ovl_copy_up_inode(c, temp); 557b10cdcdcSAmir Goldstein if (err) 558b10cdcdcSAmir Goldstein goto cleanup; 559b10cdcdcSAmir Goldstein 560b10cdcdcSAmir Goldstein if (S_ISDIR(c->stat.mode) && c->indexed) { 561b10cdcdcSAmir Goldstein err = ovl_create_index(c->dentry, c->lowerpath.dentry, temp); 562b10cdcdcSAmir Goldstein if (err) 563b10cdcdcSAmir Goldstein goto cleanup; 564b10cdcdcSAmir Goldstein } 565b10cdcdcSAmir Goldstein 5666b52243fSMiklos Szeredi upper = lookup_one_len(c->destname.name, c->destdir, c->destname.len); 5676b52243fSMiklos Szeredi err = PTR_ERR(upper); 5686b52243fSMiklos Szeredi if (IS_ERR(upper)) 5696b52243fSMiklos Szeredi goto cleanup; 5706b52243fSMiklos Szeredi 5716b52243fSMiklos Szeredi err = ovl_do_rename(wdir, temp, udir, upper, 0); 5726b52243fSMiklos Szeredi dput(upper); 573b10cdcdcSAmir Goldstein if (err) 574b10cdcdcSAmir Goldstein goto cleanup; 575b10cdcdcSAmir Goldstein 576b10cdcdcSAmir Goldstein if (!c->metacopy) 577b10cdcdcSAmir Goldstein ovl_set_upperdata(d_inode(c->dentry)); 578b10cdcdcSAmir Goldstein inode = d_inode(c->dentry); 5796b52243fSMiklos Szeredi ovl_inode_update(inode, temp); 580b10cdcdcSAmir Goldstein if (S_ISDIR(inode->i_mode)) 581b10cdcdcSAmir Goldstein ovl_set_flag(OVL_WHITEOUTS, inode); 582b10cdcdcSAmir Goldstein unlock: 583b10cdcdcSAmir Goldstein unlock_rename(c->workdir, c->destdir); 584b10cdcdcSAmir Goldstein 585b10cdcdcSAmir Goldstein return err; 586b10cdcdcSAmir Goldstein 587b10cdcdcSAmir Goldstein cleanup: 5886b52243fSMiklos Szeredi ovl_cleanup(wdir, temp); 5896b52243fSMiklos Szeredi dput(temp); 590b10cdcdcSAmir Goldstein goto unlock; 591b10cdcdcSAmir Goldstein } 592b10cdcdcSAmir Goldstein 593b10cdcdcSAmir Goldstein /* Copyup using O_TMPFILE which does not require cross dir locking */ 594b10cdcdcSAmir Goldstein static int ovl_copy_up_tmpfile(struct ovl_copy_up_ctx *c) 595b10cdcdcSAmir Goldstein { 5966b52243fSMiklos Szeredi struct inode *udir = d_inode(c->destdir); 5976b52243fSMiklos Szeredi struct dentry *temp, *upper; 5986b52243fSMiklos Szeredi struct ovl_cu_creds cc; 599b10cdcdcSAmir Goldstein int err; 600b10cdcdcSAmir Goldstein 6016b52243fSMiklos Szeredi err = ovl_prep_cu_creds(c->dentry, &cc); 6026b52243fSMiklos Szeredi if (err) 6036b52243fSMiklos Szeredi return err; 6046b52243fSMiklos Szeredi 6056b52243fSMiklos Szeredi temp = ovl_do_tmpfile(c->workdir, c->stat.mode); 6066b52243fSMiklos Szeredi ovl_revert_cu_creds(&cc); 6076b52243fSMiklos Szeredi 608b148cba4SMiklos Szeredi if (IS_ERR(temp)) 609b148cba4SMiklos Szeredi return PTR_ERR(temp); 610e9be9d5eSMiklos Szeredi 61123f0ab13SMiklos Szeredi err = ovl_copy_up_inode(c, temp); 612e9be9d5eSMiklos Szeredi if (err) 6136b52243fSMiklos Szeredi goto out_dput; 6143a1e819bSAmir Goldstein 6156b52243fSMiklos Szeredi inode_lock_nested(udir, I_MUTEX_PARENT); 6166b52243fSMiklos Szeredi 6176b52243fSMiklos Szeredi upper = lookup_one_len(c->destname.name, c->destdir, c->destname.len); 6186b52243fSMiklos Szeredi err = PTR_ERR(upper); 6196b52243fSMiklos Szeredi if (!IS_ERR(upper)) { 6206b52243fSMiklos Szeredi err = ovl_do_link(temp, udir, upper); 6216b52243fSMiklos Szeredi dput(upper); 6226b52243fSMiklos Szeredi } 6236b52243fSMiklos Szeredi inode_unlock(udir); 6246b52243fSMiklos Szeredi 625e9be9d5eSMiklos Szeredi if (err) 6266b52243fSMiklos Szeredi goto out_dput; 627e9be9d5eSMiklos Szeredi 6280c288874SVivek Goyal if (!c->metacopy) 6290c288874SVivek Goyal ovl_set_upperdata(d_inode(c->dentry)); 6306b52243fSMiklos Szeredi ovl_inode_update(d_inode(c->dentry), temp); 631b79e05aaSAmir Goldstein 6326b52243fSMiklos Szeredi return 0; 6336b52243fSMiklos Szeredi 6346b52243fSMiklos Szeredi out_dput: 635e85f82ffSMiklos Szeredi dput(temp); 636e9be9d5eSMiklos Szeredi return err; 637e9be9d5eSMiklos Szeredi } 638e9be9d5eSMiklos Szeredi 639e9be9d5eSMiklos Szeredi /* 640e9be9d5eSMiklos Szeredi * Copy up a single dentry 641e9be9d5eSMiklos Szeredi * 642a6c60655SMiklos Szeredi * All renames start with copy up of source if necessary. The actual 643a6c60655SMiklos Szeredi * rename will only proceed once the copy up was successful. Copy up uses 644a6c60655SMiklos Szeredi * upper parent i_mutex for exclusion. Since rename can change d_parent it 645a6c60655SMiklos Szeredi * is possible that the copy up will lock the old parent. At that point 646a6c60655SMiklos Szeredi * the file will have already been copied up anyway. 647e9be9d5eSMiklos Szeredi */ 648a6fb235aSMiklos Szeredi static int ovl_do_copy_up(struct ovl_copy_up_ctx *c) 649e9be9d5eSMiklos Szeredi { 650e9be9d5eSMiklos Szeredi int err; 65123f0ab13SMiklos Szeredi struct ovl_fs *ofs = c->dentry->d_sb->s_fs_info; 652016b720fSAmir Goldstein bool to_index = false; 65359be0971SAmir Goldstein 654016b720fSAmir Goldstein /* 655016b720fSAmir Goldstein * Indexed non-dir is copied up directly to the index entry and then 656016b720fSAmir Goldstein * hardlinked to upper dir. Indexed dir is copied up to indexdir, 657016b720fSAmir Goldstein * then index entry is created and then copied up dir installed. 658016b720fSAmir Goldstein * Copying dir up to indexdir instead of workdir simplifies locking. 659016b720fSAmir Goldstein */ 660016b720fSAmir Goldstein if (ovl_need_index(c->dentry)) { 661016b720fSAmir Goldstein c->indexed = true; 662016b720fSAmir Goldstein if (S_ISDIR(c->stat.mode)) 663016b720fSAmir Goldstein c->workdir = ovl_indexdir(c->dentry->d_sb); 664016b720fSAmir Goldstein else 665016b720fSAmir Goldstein to_index = true; 666016b720fSAmir Goldstein } 667016b720fSAmir Goldstein 668016b720fSAmir Goldstein if (S_ISDIR(c->stat.mode) || c->stat.nlink == 1 || to_index) 66959be0971SAmir Goldstein c->origin = true; 67059be0971SAmir Goldstein 671016b720fSAmir Goldstein if (to_index) { 67259be0971SAmir Goldstein c->destdir = ovl_indexdir(c->dentry->d_sb); 67359be0971SAmir Goldstein err = ovl_get_index_name(c->lowerpath.dentry, &c->destname); 674f3a15685SAmir Goldstein if (err) 675f3a15685SAmir Goldstein return err; 676aa3ff3c1SAmir Goldstein } else if (WARN_ON(!c->parent)) { 677aa3ff3c1SAmir Goldstein /* Disconnected dentry must be copied up to index dir */ 678aa3ff3c1SAmir Goldstein return -EIO; 67959be0971SAmir Goldstein } else { 68059be0971SAmir Goldstein /* 68159be0971SAmir Goldstein * Mark parent "impure" because it may now contain non-pure 68259be0971SAmir Goldstein * upper 68359be0971SAmir Goldstein */ 68459be0971SAmir Goldstein err = ovl_set_impure(c->parent, c->destdir); 68559be0971SAmir Goldstein if (err) 68659be0971SAmir Goldstein return err; 68759be0971SAmir Goldstein } 688f3a15685SAmir Goldstein 68901ad3eb8SAmir Goldstein /* Should we copyup with O_TMPFILE or with workdir? */ 690b10cdcdcSAmir Goldstein if (S_ISREG(c->stat.mode) && ofs->tmpfile) 691b10cdcdcSAmir Goldstein err = ovl_copy_up_tmpfile(c); 692b10cdcdcSAmir Goldstein else 693b10cdcdcSAmir Goldstein err = ovl_copy_up_workdir(c); 694aa3ff3c1SAmir Goldstein if (err) 695aa3ff3c1SAmir Goldstein goto out; 696aa3ff3c1SAmir Goldstein 697aa3ff3c1SAmir Goldstein if (c->indexed) 69859be0971SAmir Goldstein ovl_set_flag(OVL_INDEX, d_inode(c->dentry)); 699016b720fSAmir Goldstein 700016b720fSAmir Goldstein if (to_index) { 701aa3ff3c1SAmir Goldstein /* Initialize nlink for copy up of disconnected dentry */ 702aa3ff3c1SAmir Goldstein err = ovl_set_nlink_upper(c->dentry); 703aa3ff3c1SAmir Goldstein } else { 70459be0971SAmir Goldstein struct inode *udir = d_inode(c->destdir); 70559be0971SAmir Goldstein 70659be0971SAmir Goldstein /* Restore timestamps on parent (best effort) */ 70759be0971SAmir Goldstein inode_lock(udir); 70859be0971SAmir Goldstein ovl_set_timestamps(c->destdir, &c->pstat); 70959be0971SAmir Goldstein inode_unlock(udir); 71059be0971SAmir Goldstein 71159be0971SAmir Goldstein ovl_dentry_set_upper_alias(c->dentry); 712fd210b7dSMiklos Szeredi } 713a6fb235aSMiklos Szeredi 714aa3ff3c1SAmir Goldstein out: 715aa3ff3c1SAmir Goldstein if (to_index) 716aa3ff3c1SAmir Goldstein kfree(c->destname.name); 717a6fb235aSMiklos Szeredi return err; 718a6fb235aSMiklos Szeredi } 719a6fb235aSMiklos Szeredi 72044d5bf10SVivek Goyal static bool ovl_need_meta_copy_up(struct dentry *dentry, umode_t mode, 72144d5bf10SVivek Goyal int flags) 72244d5bf10SVivek Goyal { 72344d5bf10SVivek Goyal struct ovl_fs *ofs = dentry->d_sb->s_fs_info; 72444d5bf10SVivek Goyal 72544d5bf10SVivek Goyal if (!ofs->config.metacopy) 72644d5bf10SVivek Goyal return false; 72744d5bf10SVivek Goyal 72844d5bf10SVivek Goyal if (!S_ISREG(mode)) 72944d5bf10SVivek Goyal return false; 73044d5bf10SVivek Goyal 73144d5bf10SVivek Goyal if (flags && ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC))) 73244d5bf10SVivek Goyal return false; 73344d5bf10SVivek Goyal 73444d5bf10SVivek Goyal return true; 73544d5bf10SVivek Goyal } 73644d5bf10SVivek Goyal 7370c288874SVivek Goyal /* Copy up data of an inode which was copied up metadata only in the past. */ 7380c288874SVivek Goyal static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c) 7390c288874SVivek Goyal { 7404f93b426SVivek Goyal struct path upperpath, datapath; 7410c288874SVivek Goyal int err; 742993a0b2aSVivek Goyal char *capability = NULL; 743993a0b2aSVivek Goyal ssize_t uninitialized_var(cap_size); 7440c288874SVivek Goyal 7450c288874SVivek Goyal ovl_path_upper(c->dentry, &upperpath); 7460c288874SVivek Goyal if (WARN_ON(upperpath.dentry == NULL)) 7470c288874SVivek Goyal return -EIO; 7480c288874SVivek Goyal 7494f93b426SVivek Goyal ovl_path_lowerdata(c->dentry, &datapath); 7504f93b426SVivek Goyal if (WARN_ON(datapath.dentry == NULL)) 7514f93b426SVivek Goyal return -EIO; 7524f93b426SVivek Goyal 753993a0b2aSVivek Goyal if (c->stat.size) { 754993a0b2aSVivek Goyal err = cap_size = ovl_getxattr(upperpath.dentry, XATTR_NAME_CAPS, 755993a0b2aSVivek Goyal &capability, 0); 756993a0b2aSVivek Goyal if (err < 0 && err != -ENODATA) 757993a0b2aSVivek Goyal goto out; 758993a0b2aSVivek Goyal } 759993a0b2aSVivek Goyal 7604f93b426SVivek Goyal err = ovl_copy_up_data(&datapath, &upperpath, c->stat.size); 7610c288874SVivek Goyal if (err) 762993a0b2aSVivek Goyal goto out_free; 763993a0b2aSVivek Goyal 764993a0b2aSVivek Goyal /* 765993a0b2aSVivek Goyal * Writing to upper file will clear security.capability xattr. We 766993a0b2aSVivek Goyal * don't want that to happen for normal copy-up operation. 767993a0b2aSVivek Goyal */ 768993a0b2aSVivek Goyal if (capability) { 769993a0b2aSVivek Goyal err = ovl_do_setxattr(upperpath.dentry, XATTR_NAME_CAPS, 770993a0b2aSVivek Goyal capability, cap_size, 0); 771993a0b2aSVivek Goyal if (err) 772993a0b2aSVivek Goyal goto out_free; 773993a0b2aSVivek Goyal } 774993a0b2aSVivek Goyal 7750c288874SVivek Goyal 7760c288874SVivek Goyal err = vfs_removexattr(upperpath.dentry, OVL_XATTR_METACOPY); 7770c288874SVivek Goyal if (err) 778993a0b2aSVivek Goyal goto out_free; 7790c288874SVivek Goyal 7800c288874SVivek Goyal ovl_set_upperdata(d_inode(c->dentry)); 781993a0b2aSVivek Goyal out_free: 782993a0b2aSVivek Goyal kfree(capability); 783993a0b2aSVivek Goyal out: 7840c288874SVivek Goyal return err; 7850c288874SVivek Goyal } 7860c288874SVivek Goyal 787a6fb235aSMiklos Szeredi static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, 788a6fb235aSMiklos Szeredi int flags) 789a6fb235aSMiklos Szeredi { 790a6fb235aSMiklos Szeredi int err; 791a6fb235aSMiklos Szeredi DEFINE_DELAYED_CALL(done); 792a6fb235aSMiklos Szeredi struct path parentpath; 793a6fb235aSMiklos Szeredi struct ovl_copy_up_ctx ctx = { 794a6fb235aSMiklos Szeredi .parent = parent, 795a6fb235aSMiklos Szeredi .dentry = dentry, 796a6fb235aSMiklos Szeredi .workdir = ovl_workdir(dentry), 797a6fb235aSMiklos Szeredi }; 798a6fb235aSMiklos Szeredi 799a6fb235aSMiklos Szeredi if (WARN_ON(!ctx.workdir)) 800a6fb235aSMiklos Szeredi return -EROFS; 801a6fb235aSMiklos Szeredi 802a6fb235aSMiklos Szeredi ovl_path_lower(dentry, &ctx.lowerpath); 803a6fb235aSMiklos Szeredi err = vfs_getattr(&ctx.lowerpath, &ctx.stat, 804a6fb235aSMiklos Szeredi STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT); 805a6fb235aSMiklos Szeredi if (err) 806a6fb235aSMiklos Szeredi return err; 807a6fb235aSMiklos Szeredi 80844d5bf10SVivek Goyal ctx.metacopy = ovl_need_meta_copy_up(dentry, ctx.stat.mode, flags); 80944d5bf10SVivek Goyal 810aa3ff3c1SAmir Goldstein if (parent) { 811a6fb235aSMiklos Szeredi ovl_path_upper(parent, &parentpath); 81259be0971SAmir Goldstein ctx.destdir = parentpath.dentry; 81359be0971SAmir Goldstein ctx.destname = dentry->d_name; 814a6fb235aSMiklos Szeredi 815a6fb235aSMiklos Szeredi err = vfs_getattr(&parentpath, &ctx.pstat, 816aa3ff3c1SAmir Goldstein STATX_ATIME | STATX_MTIME, 817aa3ff3c1SAmir Goldstein AT_STATX_SYNC_AS_STAT); 818a6fb235aSMiklos Szeredi if (err) 819a6fb235aSMiklos Szeredi return err; 820aa3ff3c1SAmir Goldstein } 821a6fb235aSMiklos Szeredi 822a6fb235aSMiklos Szeredi /* maybe truncate regular file. this has no effect on dirs */ 823a6fb235aSMiklos Szeredi if (flags & O_TRUNC) 824a6fb235aSMiklos Szeredi ctx.stat.size = 0; 825a6fb235aSMiklos Szeredi 826a6fb235aSMiklos Szeredi if (S_ISLNK(ctx.stat.mode)) { 827a6fb235aSMiklos Szeredi ctx.link = vfs_get_link(ctx.lowerpath.dentry, &done); 828a6fb235aSMiklos Szeredi if (IS_ERR(ctx.link)) 829a6fb235aSMiklos Szeredi return PTR_ERR(ctx.link); 830a6fb235aSMiklos Szeredi } 831a6fb235aSMiklos Szeredi 8320c288874SVivek Goyal err = ovl_copy_up_start(dentry, flags); 833fd210b7dSMiklos Szeredi /* err < 0: interrupted, err > 0: raced with another copy-up */ 834fd210b7dSMiklos Szeredi if (unlikely(err)) { 835fd210b7dSMiklos Szeredi if (err > 0) 836fd210b7dSMiklos Szeredi err = 0; 837fd210b7dSMiklos Szeredi } else { 83859be0971SAmir Goldstein if (!ovl_dentry_upper(dentry)) 839a6fb235aSMiklos Szeredi err = ovl_do_copy_up(&ctx); 840aa3ff3c1SAmir Goldstein if (!err && parent && !ovl_dentry_has_upper_alias(dentry)) 841f4439de1SAmir Goldstein err = ovl_link_up(&ctx); 8420c288874SVivek Goyal if (!err && ovl_dentry_needs_data_copy_up_locked(dentry, flags)) 8430c288874SVivek Goyal err = ovl_copy_up_meta_inode_data(&ctx); 844fd210b7dSMiklos Szeredi ovl_copy_up_end(dentry); 845fd210b7dSMiklos Szeredi } 8467764235bSMiklos Szeredi do_delayed_call(&done); 847e9be9d5eSMiklos Szeredi 848e9be9d5eSMiklos Szeredi return err; 849e9be9d5eSMiklos Szeredi } 850e9be9d5eSMiklos Szeredi 8519aba6521SAmir Goldstein int ovl_copy_up_flags(struct dentry *dentry, int flags) 852e9be9d5eSMiklos Szeredi { 8538eac98b8SVivek Goyal int err = 0; 8548eac98b8SVivek Goyal const struct cred *old_cred = ovl_override_creds(dentry->d_sb); 855aa3ff3c1SAmir Goldstein bool disconnected = (dentry->d_flags & DCACHE_DISCONNECTED); 856aa3ff3c1SAmir Goldstein 857aa3ff3c1SAmir Goldstein /* 858aa3ff3c1SAmir Goldstein * With NFS export, copy up can get called for a disconnected non-dir. 859aa3ff3c1SAmir Goldstein * In this case, we will copy up lower inode to index dir without 860aa3ff3c1SAmir Goldstein * linking it to upper dir. 861aa3ff3c1SAmir Goldstein */ 862aa3ff3c1SAmir Goldstein if (WARN_ON(disconnected && d_is_dir(dentry))) 863aa3ff3c1SAmir Goldstein return -EIO; 864e9be9d5eSMiklos Szeredi 865e9be9d5eSMiklos Szeredi while (!err) { 866e9be9d5eSMiklos Szeredi struct dentry *next; 867aa3ff3c1SAmir Goldstein struct dentry *parent = NULL; 868e9be9d5eSMiklos Szeredi 8690c288874SVivek Goyal if (ovl_already_copied_up(dentry, flags)) 870e9be9d5eSMiklos Szeredi break; 871e9be9d5eSMiklos Szeredi 872e9be9d5eSMiklos Szeredi next = dget(dentry); 873e9be9d5eSMiklos Szeredi /* find the topmost dentry not yet copied up */ 874aa3ff3c1SAmir Goldstein for (; !disconnected;) { 875e9be9d5eSMiklos Szeredi parent = dget_parent(next); 876e9be9d5eSMiklos Szeredi 87759be0971SAmir Goldstein if (ovl_dentry_upper(parent)) 878e9be9d5eSMiklos Szeredi break; 879e9be9d5eSMiklos Szeredi 880e9be9d5eSMiklos Szeredi dput(next); 881e9be9d5eSMiklos Szeredi next = parent; 882e9be9d5eSMiklos Szeredi } 883e9be9d5eSMiklos Szeredi 884a6fb235aSMiklos Szeredi err = ovl_copy_up_one(parent, next, flags); 885e9be9d5eSMiklos Szeredi 886e9be9d5eSMiklos Szeredi dput(parent); 887e9be9d5eSMiklos Szeredi dput(next); 888e9be9d5eSMiklos Szeredi } 8898eac98b8SVivek Goyal revert_creds(old_cred); 890e9be9d5eSMiklos Szeredi 891e9be9d5eSMiklos Szeredi return err; 892e9be9d5eSMiklos Szeredi } 8939aba6521SAmir Goldstein 894d6eac039SVivek Goyal static bool ovl_open_need_copy_up(struct dentry *dentry, int flags) 895d6eac039SVivek Goyal { 896d6eac039SVivek Goyal /* Copy up of disconnected dentry does not set upper alias */ 8970c288874SVivek Goyal if (ovl_already_copied_up(dentry, flags)) 898d6eac039SVivek Goyal return false; 899d6eac039SVivek Goyal 900d6eac039SVivek Goyal if (special_file(d_inode(dentry)->i_mode)) 901d6eac039SVivek Goyal return false; 902d6eac039SVivek Goyal 9030c288874SVivek Goyal if (!ovl_open_flags_need_copy_up(flags)) 904d6eac039SVivek Goyal return false; 905d6eac039SVivek Goyal 906d6eac039SVivek Goyal return true; 907d6eac039SVivek Goyal } 908d6eac039SVivek Goyal 9093428030dSAmir Goldstein int ovl_maybe_copy_up(struct dentry *dentry, int flags) 910d6eac039SVivek Goyal { 911d6eac039SVivek Goyal int err = 0; 912d6eac039SVivek Goyal 9133428030dSAmir Goldstein if (ovl_open_need_copy_up(dentry, flags)) { 914d6eac039SVivek Goyal err = ovl_want_write(dentry); 915d6eac039SVivek Goyal if (!err) { 9163428030dSAmir Goldstein err = ovl_copy_up_flags(dentry, flags); 917d6eac039SVivek Goyal ovl_drop_write(dentry); 918d6eac039SVivek Goyal } 919d6eac039SVivek Goyal } 920d6eac039SVivek Goyal 921d6eac039SVivek Goyal return err; 922d6eac039SVivek Goyal } 923d6eac039SVivek Goyal 924d1e6f6a9SVivek Goyal int ovl_copy_up_with_data(struct dentry *dentry) 925d1e6f6a9SVivek Goyal { 926d1e6f6a9SVivek Goyal return ovl_copy_up_flags(dentry, O_WRONLY); 927d1e6f6a9SVivek Goyal } 928d1e6f6a9SVivek Goyal 9299aba6521SAmir Goldstein int ovl_copy_up(struct dentry *dentry) 9309aba6521SAmir Goldstein { 9319aba6521SAmir Goldstein return ovl_copy_up_flags(dentry, 0); 9329aba6521SAmir Goldstein } 933