1e9be9d5eSMiklos Szeredi /* 2e9be9d5eSMiklos Szeredi * 3e9be9d5eSMiklos Szeredi * Copyright (C) 2011 Novell Inc. 4e9be9d5eSMiklos Szeredi * 5e9be9d5eSMiklos Szeredi * This program is free software; you can redistribute it and/or modify it 6e9be9d5eSMiklos Szeredi * under the terms of the GNU General Public License version 2 as published by 7e9be9d5eSMiklos Szeredi * the Free Software Foundation. 8e9be9d5eSMiklos Szeredi */ 9e9be9d5eSMiklos Szeredi 10fb5bb2c3SDavid Howells #include <linux/module.h> 11e9be9d5eSMiklos Szeredi #include <linux/fs.h> 12e9be9d5eSMiklos Szeredi #include <linux/slab.h> 13e9be9d5eSMiklos Szeredi #include <linux/file.h> 14e9be9d5eSMiklos Szeredi #include <linux/splice.h> 15e9be9d5eSMiklos Szeredi #include <linux/xattr.h> 16e9be9d5eSMiklos Szeredi #include <linux/security.h> 17e9be9d5eSMiklos Szeredi #include <linux/uaccess.h> 18174cd4b1SIngo Molnar #include <linux/sched/signal.h> 195b825c3aSIngo Molnar #include <linux/cred.h> 20e9be9d5eSMiklos Szeredi #include <linux/namei.h> 21fb5bb2c3SDavid Howells #include <linux/fdtable.h> 22fb5bb2c3SDavid Howells #include <linux/ratelimit.h> 233a1e819bSAmir Goldstein #include <linux/exportfs.h> 24e9be9d5eSMiklos Szeredi #include "overlayfs.h" 25e9be9d5eSMiklos Szeredi 26e9be9d5eSMiklos Szeredi #define OVL_COPY_UP_CHUNK_SIZE (1 << 20) 27e9be9d5eSMiklos Szeredi 28670c2324SMiklos Szeredi static int ovl_ccup_set(const char *buf, const struct kernel_param *param) 29fb5bb2c3SDavid Howells { 30670c2324SMiklos Szeredi pr_warn("overlayfs: \"check_copy_up\" module option is obsolete\n"); 31fb5bb2c3SDavid Howells return 0; 32fb5bb2c3SDavid Howells } 33fb5bb2c3SDavid Howells 34670c2324SMiklos Szeredi static int ovl_ccup_get(char *buf, const struct kernel_param *param) 35fb5bb2c3SDavid Howells { 36670c2324SMiklos Szeredi return sprintf(buf, "N\n"); 37fb5bb2c3SDavid Howells } 38fb5bb2c3SDavid Howells 39670c2324SMiklos Szeredi module_param_call(check_copy_up, ovl_ccup_set, ovl_ccup_get, NULL, 0644); 40670c2324SMiklos Szeredi MODULE_PARM_DESC(ovl_check_copy_up, "Obsolete; does nothing"); 41670c2324SMiklos Szeredi 42e9be9d5eSMiklos Szeredi int ovl_copy_xattr(struct dentry *old, struct dentry *new) 43e9be9d5eSMiklos Szeredi { 44e4ad29faSVito Caputo ssize_t list_size, size, value_size = 0; 45e4ad29faSVito Caputo char *buf, *name, *value = NULL; 46e4ad29faSVito Caputo int uninitialized_var(error); 478b326c61SMiklos Szeredi size_t slen; 48e9be9d5eSMiklos Szeredi 495d6c3191SAndreas Gruenbacher if (!(old->d_inode->i_opflags & IOP_XATTR) || 505d6c3191SAndreas Gruenbacher !(new->d_inode->i_opflags & IOP_XATTR)) 51e9be9d5eSMiklos Szeredi return 0; 52e9be9d5eSMiklos Szeredi 53e9be9d5eSMiklos Szeredi list_size = vfs_listxattr(old, NULL, 0); 54e9be9d5eSMiklos Szeredi if (list_size <= 0) { 55e9be9d5eSMiklos Szeredi if (list_size == -EOPNOTSUPP) 56e9be9d5eSMiklos Szeredi return 0; 57e9be9d5eSMiklos Szeredi return list_size; 58e9be9d5eSMiklos Szeredi } 59e9be9d5eSMiklos Szeredi 60e9be9d5eSMiklos Szeredi buf = kzalloc(list_size, GFP_KERNEL); 61e9be9d5eSMiklos Szeredi if (!buf) 62e9be9d5eSMiklos Szeredi return -ENOMEM; 63e9be9d5eSMiklos Szeredi 64e9be9d5eSMiklos Szeredi list_size = vfs_listxattr(old, buf, list_size); 65e9be9d5eSMiklos Szeredi if (list_size <= 0) { 66e9be9d5eSMiklos Szeredi error = list_size; 67e4ad29faSVito Caputo goto out; 68e9be9d5eSMiklos Szeredi } 69e9be9d5eSMiklos Szeredi 708b326c61SMiklos Szeredi for (name = buf; list_size; name += slen) { 718b326c61SMiklos Szeredi slen = strnlen(name, list_size) + 1; 728b326c61SMiklos Szeredi 738b326c61SMiklos Szeredi /* underlying fs providing us with an broken xattr list? */ 748b326c61SMiklos Szeredi if (WARN_ON(slen > list_size)) { 758b326c61SMiklos Szeredi error = -EIO; 768b326c61SMiklos Szeredi break; 778b326c61SMiklos Szeredi } 788b326c61SMiklos Szeredi list_size -= slen; 798b326c61SMiklos Szeredi 800956254aSMiklos Szeredi if (ovl_is_private_xattr(name)) 810956254aSMiklos Szeredi continue; 82e4ad29faSVito Caputo retry: 83e4ad29faSVito Caputo size = vfs_getxattr(old, name, value, value_size); 84e4ad29faSVito Caputo if (size == -ERANGE) 85e4ad29faSVito Caputo size = vfs_getxattr(old, name, NULL, 0); 86e4ad29faSVito Caputo 8797daf8b9SMiklos Szeredi if (size < 0) { 88e9be9d5eSMiklos Szeredi error = size; 89e4ad29faSVito Caputo break; 90e9be9d5eSMiklos Szeredi } 91e9be9d5eSMiklos Szeredi 92e4ad29faSVito Caputo if (size > value_size) { 93e4ad29faSVito Caputo void *new; 94e4ad29faSVito Caputo 95e4ad29faSVito Caputo new = krealloc(value, size, GFP_KERNEL); 96e4ad29faSVito Caputo if (!new) { 97e4ad29faSVito Caputo error = -ENOMEM; 98e4ad29faSVito Caputo break; 99e4ad29faSVito Caputo } 100e4ad29faSVito Caputo value = new; 101e4ad29faSVito Caputo value_size = size; 102e4ad29faSVito Caputo goto retry; 103e4ad29faSVito Caputo } 104e4ad29faSVito Caputo 105121ab822SVivek Goyal error = security_inode_copy_up_xattr(name); 106121ab822SVivek Goyal if (error < 0 && error != -EOPNOTSUPP) 107121ab822SVivek Goyal break; 108121ab822SVivek Goyal if (error == 1) { 109121ab822SVivek Goyal error = 0; 110121ab822SVivek Goyal continue; /* Discard */ 111121ab822SVivek Goyal } 112e4ad29faSVito Caputo error = vfs_setxattr(new, name, value, size, 0); 113e4ad29faSVito Caputo if (error) 114e4ad29faSVito Caputo break; 115e4ad29faSVito Caputo } 116e9be9d5eSMiklos Szeredi kfree(value); 117e9be9d5eSMiklos Szeredi out: 118e9be9d5eSMiklos Szeredi kfree(buf); 119e9be9d5eSMiklos Szeredi return error; 120e9be9d5eSMiklos Szeredi } 121e9be9d5eSMiklos Szeredi 122e9be9d5eSMiklos Szeredi static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len) 123e9be9d5eSMiklos Szeredi { 124e9be9d5eSMiklos Szeredi struct file *old_file; 125e9be9d5eSMiklos Szeredi struct file *new_file; 126e9be9d5eSMiklos Szeredi loff_t old_pos = 0; 127e9be9d5eSMiklos Szeredi loff_t new_pos = 0; 128e9be9d5eSMiklos Szeredi int error = 0; 129e9be9d5eSMiklos Szeredi 130e9be9d5eSMiklos Szeredi if (len == 0) 131e9be9d5eSMiklos Szeredi return 0; 132e9be9d5eSMiklos Szeredi 1330480334fSDavid Howells old_file = ovl_path_open(old, O_LARGEFILE | O_RDONLY); 134e9be9d5eSMiklos Szeredi if (IS_ERR(old_file)) 135e9be9d5eSMiklos Szeredi return PTR_ERR(old_file); 136e9be9d5eSMiklos Szeredi 1370480334fSDavid Howells new_file = ovl_path_open(new, O_LARGEFILE | O_WRONLY); 138e9be9d5eSMiklos Szeredi if (IS_ERR(new_file)) { 139e9be9d5eSMiklos Szeredi error = PTR_ERR(new_file); 140e9be9d5eSMiklos Szeredi goto out_fput; 141e9be9d5eSMiklos Szeredi } 142e9be9d5eSMiklos Szeredi 1432ea98466SAmir Goldstein /* Try to use clone_file_range to clone up within the same fs */ 144a725356bSAmir Goldstein error = do_clone_file_range(old_file, 0, new_file, 0, len); 1452ea98466SAmir Goldstein if (!error) 1462ea98466SAmir Goldstein goto out; 1472ea98466SAmir Goldstein /* Couldn't clone, so now we try to copy the data */ 1482ea98466SAmir Goldstein error = 0; 1492ea98466SAmir Goldstein 150e9be9d5eSMiklos Szeredi /* FIXME: copy up sparse files efficiently */ 151e9be9d5eSMiklos Szeredi while (len) { 152e9be9d5eSMiklos Szeredi size_t this_len = OVL_COPY_UP_CHUNK_SIZE; 153e9be9d5eSMiklos Szeredi long bytes; 154e9be9d5eSMiklos Szeredi 155e9be9d5eSMiklos Szeredi if (len < this_len) 156e9be9d5eSMiklos Szeredi this_len = len; 157e9be9d5eSMiklos Szeredi 158e9be9d5eSMiklos Szeredi if (signal_pending_state(TASK_KILLABLE, current)) { 159e9be9d5eSMiklos Szeredi error = -EINTR; 160e9be9d5eSMiklos Szeredi break; 161e9be9d5eSMiklos Szeredi } 162e9be9d5eSMiklos Szeredi 163e9be9d5eSMiklos Szeredi bytes = do_splice_direct(old_file, &old_pos, 164e9be9d5eSMiklos Szeredi new_file, &new_pos, 165e9be9d5eSMiklos Szeredi this_len, SPLICE_F_MOVE); 166e9be9d5eSMiklos Szeredi if (bytes <= 0) { 167e9be9d5eSMiklos Szeredi error = bytes; 168e9be9d5eSMiklos Szeredi break; 169e9be9d5eSMiklos Szeredi } 170e9be9d5eSMiklos Szeredi WARN_ON(old_pos != new_pos); 171e9be9d5eSMiklos Szeredi 172e9be9d5eSMiklos Szeredi len -= bytes; 173e9be9d5eSMiklos Szeredi } 1742ea98466SAmir Goldstein out: 175641089c1SMiklos Szeredi if (!error) 176641089c1SMiklos Szeredi error = vfs_fsync(new_file, 0); 177e9be9d5eSMiklos Szeredi fput(new_file); 178e9be9d5eSMiklos Szeredi out_fput: 179e9be9d5eSMiklos Szeredi fput(old_file); 180e9be9d5eSMiklos Szeredi return error; 181e9be9d5eSMiklos Szeredi } 182e9be9d5eSMiklos Szeredi 1830c288874SVivek Goyal static int ovl_set_size(struct dentry *upperdentry, struct kstat *stat) 1840c288874SVivek Goyal { 1850c288874SVivek Goyal struct iattr attr = { 1860c288874SVivek Goyal .ia_valid = ATTR_SIZE, 1870c288874SVivek Goyal .ia_size = stat->size, 1880c288874SVivek Goyal }; 1890c288874SVivek Goyal 1900c288874SVivek Goyal return notify_change(upperdentry, &attr, NULL); 1910c288874SVivek Goyal } 1920c288874SVivek Goyal 193e9be9d5eSMiklos Szeredi static int ovl_set_timestamps(struct dentry *upperdentry, struct kstat *stat) 194e9be9d5eSMiklos Szeredi { 195e9be9d5eSMiklos Szeredi struct iattr attr = { 196e9be9d5eSMiklos Szeredi .ia_valid = 197e9be9d5eSMiklos Szeredi ATTR_ATIME | ATTR_MTIME | ATTR_ATIME_SET | ATTR_MTIME_SET, 198e9be9d5eSMiklos Szeredi .ia_atime = stat->atime, 199e9be9d5eSMiklos Szeredi .ia_mtime = stat->mtime, 200e9be9d5eSMiklos Szeredi }; 201e9be9d5eSMiklos Szeredi 202e9be9d5eSMiklos Szeredi return notify_change(upperdentry, &attr, NULL); 203e9be9d5eSMiklos Szeredi } 204e9be9d5eSMiklos Szeredi 205e9be9d5eSMiklos Szeredi int ovl_set_attr(struct dentry *upperdentry, struct kstat *stat) 206e9be9d5eSMiklos Szeredi { 207e9be9d5eSMiklos Szeredi int err = 0; 208e9be9d5eSMiklos Szeredi 209e9be9d5eSMiklos Szeredi if (!S_ISLNK(stat->mode)) { 210e9be9d5eSMiklos Szeredi struct iattr attr = { 211e9be9d5eSMiklos Szeredi .ia_valid = ATTR_MODE, 212e9be9d5eSMiklos Szeredi .ia_mode = stat->mode, 213e9be9d5eSMiklos Szeredi }; 214e9be9d5eSMiklos Szeredi err = notify_change(upperdentry, &attr, NULL); 215e9be9d5eSMiklos Szeredi } 216e9be9d5eSMiklos Szeredi if (!err) { 217e9be9d5eSMiklos Szeredi struct iattr attr = { 218e9be9d5eSMiklos Szeredi .ia_valid = ATTR_UID | ATTR_GID, 219e9be9d5eSMiklos Szeredi .ia_uid = stat->uid, 220e9be9d5eSMiklos Szeredi .ia_gid = stat->gid, 221e9be9d5eSMiklos Szeredi }; 222e9be9d5eSMiklos Szeredi err = notify_change(upperdentry, &attr, NULL); 223e9be9d5eSMiklos Szeredi } 224e9be9d5eSMiklos Szeredi if (!err) 225e9be9d5eSMiklos Szeredi ovl_set_timestamps(upperdentry, stat); 226e9be9d5eSMiklos Szeredi 227e9be9d5eSMiklos Szeredi return err; 228e9be9d5eSMiklos Szeredi } 229e9be9d5eSMiklos Szeredi 2305b2cccd3SAmir Goldstein struct ovl_fh *ovl_encode_real_fh(struct dentry *real, bool is_upper) 2313a1e819bSAmir Goldstein { 2323a1e819bSAmir Goldstein struct ovl_fh *fh; 2333a1e819bSAmir Goldstein int fh_type, fh_len, dwords; 2343a1e819bSAmir Goldstein void *buf; 2353a1e819bSAmir Goldstein int buflen = MAX_HANDLE_SZ; 23605122443SAmir Goldstein uuid_t *uuid = &real->d_sb->s_uuid; 2373a1e819bSAmir Goldstein 2380ee931c4SMichal Hocko buf = kmalloc(buflen, GFP_KERNEL); 2393a1e819bSAmir Goldstein if (!buf) 2403a1e819bSAmir Goldstein return ERR_PTR(-ENOMEM); 2413a1e819bSAmir Goldstein 2423a1e819bSAmir Goldstein /* 2433a1e819bSAmir Goldstein * We encode a non-connectable file handle for non-dir, because we 2443a1e819bSAmir Goldstein * only need to find the lower inode number and we don't want to pay 2453a1e819bSAmir Goldstein * the price or reconnecting the dentry. 2463a1e819bSAmir Goldstein */ 2473a1e819bSAmir Goldstein dwords = buflen >> 2; 24805122443SAmir Goldstein fh_type = exportfs_encode_fh(real, buf, &dwords, 0); 2493a1e819bSAmir Goldstein buflen = (dwords << 2); 2503a1e819bSAmir Goldstein 2513a1e819bSAmir Goldstein fh = ERR_PTR(-EIO); 2523a1e819bSAmir Goldstein if (WARN_ON(fh_type < 0) || 2533a1e819bSAmir Goldstein WARN_ON(buflen > MAX_HANDLE_SZ) || 2543a1e819bSAmir Goldstein WARN_ON(fh_type == FILEID_INVALID)) 2553a1e819bSAmir Goldstein goto out; 2563a1e819bSAmir Goldstein 2573a1e819bSAmir Goldstein BUILD_BUG_ON(MAX_HANDLE_SZ + offsetof(struct ovl_fh, fid) > 255); 2583a1e819bSAmir Goldstein fh_len = offsetof(struct ovl_fh, fid) + buflen; 2593a1e819bSAmir Goldstein fh = kmalloc(fh_len, GFP_KERNEL); 2603a1e819bSAmir Goldstein if (!fh) { 2613a1e819bSAmir Goldstein fh = ERR_PTR(-ENOMEM); 2623a1e819bSAmir Goldstein goto out; 2633a1e819bSAmir Goldstein } 2643a1e819bSAmir Goldstein 2653a1e819bSAmir Goldstein fh->version = OVL_FH_VERSION; 2663a1e819bSAmir Goldstein fh->magic = OVL_FH_MAGIC; 2673a1e819bSAmir Goldstein fh->type = fh_type; 2683a1e819bSAmir Goldstein fh->flags = OVL_FH_FLAG_CPU_ENDIAN; 26954fb347eSAmir Goldstein /* 27054fb347eSAmir Goldstein * When we will want to decode an overlay dentry from this handle 27154fb347eSAmir Goldstein * and all layers are on the same fs, if we get a disconncted real 27254fb347eSAmir Goldstein * dentry when we decode fid, the only way to tell if we should assign 27354fb347eSAmir Goldstein * it to upperdentry or to lowerstack is by checking this flag. 27454fb347eSAmir Goldstein */ 27554fb347eSAmir Goldstein if (is_upper) 27654fb347eSAmir Goldstein fh->flags |= OVL_FH_FLAG_PATH_UPPER; 2773a1e819bSAmir Goldstein fh->len = fh_len; 2783a1e819bSAmir Goldstein fh->uuid = *uuid; 2793a1e819bSAmir Goldstein memcpy(fh->fid, buf, buflen); 2803a1e819bSAmir Goldstein 2813a1e819bSAmir Goldstein out: 2823a1e819bSAmir Goldstein kfree(buf); 2833a1e819bSAmir Goldstein return fh; 2843a1e819bSAmir Goldstein } 2853a1e819bSAmir Goldstein 2869678e630SAmir Goldstein int ovl_set_origin(struct dentry *dentry, struct dentry *lower, 2873a1e819bSAmir Goldstein struct dentry *upper) 2883a1e819bSAmir Goldstein { 2893a1e819bSAmir Goldstein const struct ovl_fh *fh = NULL; 2903a1e819bSAmir Goldstein int err; 2913a1e819bSAmir Goldstein 2923a1e819bSAmir Goldstein /* 2933a1e819bSAmir Goldstein * When lower layer doesn't support export operations store a 'null' fh, 2943a1e819bSAmir Goldstein * so we can use the overlay.origin xattr to distignuish between a copy 2953a1e819bSAmir Goldstein * up and a pure upper inode. 2963a1e819bSAmir Goldstein */ 29702bcd157SAmir Goldstein if (ovl_can_decode_fh(lower->d_sb)) { 2985b2cccd3SAmir Goldstein fh = ovl_encode_real_fh(lower, false); 2993a1e819bSAmir Goldstein if (IS_ERR(fh)) 3003a1e819bSAmir Goldstein return PTR_ERR(fh); 3013a1e819bSAmir Goldstein } 3023a1e819bSAmir Goldstein 3036266d465SMiklos Szeredi /* 3046266d465SMiklos Szeredi * Do not fail when upper doesn't support xattrs. 3056266d465SMiklos Szeredi */ 3066266d465SMiklos Szeredi err = ovl_check_setxattr(dentry, upper, OVL_XATTR_ORIGIN, fh, 3076266d465SMiklos Szeredi fh ? fh->len : 0, 0); 3083a1e819bSAmir Goldstein kfree(fh); 3093a1e819bSAmir Goldstein 3103a1e819bSAmir Goldstein return err; 3113a1e819bSAmir Goldstein } 3123a1e819bSAmir Goldstein 313016b720fSAmir Goldstein /* Store file handle of @upper dir in @index dir entry */ 314016b720fSAmir Goldstein static int ovl_set_upper_fh(struct dentry *upper, struct dentry *index) 315016b720fSAmir Goldstein { 316016b720fSAmir Goldstein const struct ovl_fh *fh; 317016b720fSAmir Goldstein int err; 318016b720fSAmir Goldstein 3195b2cccd3SAmir Goldstein fh = ovl_encode_real_fh(upper, true); 320016b720fSAmir Goldstein if (IS_ERR(fh)) 321016b720fSAmir Goldstein return PTR_ERR(fh); 322016b720fSAmir Goldstein 323016b720fSAmir Goldstein err = ovl_do_setxattr(index, OVL_XATTR_UPPER, fh, fh->len, 0); 324016b720fSAmir Goldstein 325016b720fSAmir Goldstein kfree(fh); 326016b720fSAmir Goldstein return err; 327016b720fSAmir Goldstein } 328016b720fSAmir Goldstein 329016b720fSAmir Goldstein /* 330016b720fSAmir Goldstein * Create and install index entry. 331016b720fSAmir Goldstein * 332016b720fSAmir Goldstein * Caller must hold i_mutex on indexdir. 333016b720fSAmir Goldstein */ 334016b720fSAmir Goldstein static int ovl_create_index(struct dentry *dentry, struct dentry *origin, 335016b720fSAmir Goldstein struct dentry *upper) 336016b720fSAmir Goldstein { 337016b720fSAmir Goldstein struct dentry *indexdir = ovl_indexdir(dentry->d_sb); 338016b720fSAmir Goldstein struct inode *dir = d_inode(indexdir); 339016b720fSAmir Goldstein struct dentry *index = NULL; 340016b720fSAmir Goldstein struct dentry *temp = NULL; 341016b720fSAmir Goldstein struct qstr name = { }; 342016b720fSAmir Goldstein int err; 343016b720fSAmir Goldstein 344016b720fSAmir Goldstein /* 345016b720fSAmir Goldstein * For now this is only used for creating index entry for directories, 346016b720fSAmir Goldstein * because non-dir are copied up directly to index and then hardlinked 347016b720fSAmir Goldstein * to upper dir. 348016b720fSAmir Goldstein * 349016b720fSAmir Goldstein * TODO: implement create index for non-dir, so we can call it when 350016b720fSAmir Goldstein * encoding file handle for non-dir in case index does not exist. 351016b720fSAmir Goldstein */ 352016b720fSAmir Goldstein if (WARN_ON(!d_is_dir(dentry))) 353016b720fSAmir Goldstein return -EIO; 354016b720fSAmir Goldstein 355016b720fSAmir Goldstein /* Directory not expected to be indexed before copy up */ 356016b720fSAmir Goldstein if (WARN_ON(ovl_test_flag(OVL_INDEX, d_inode(dentry)))) 357016b720fSAmir Goldstein return -EIO; 358016b720fSAmir Goldstein 359016b720fSAmir Goldstein err = ovl_get_index_name(origin, &name); 360016b720fSAmir Goldstein if (err) 361016b720fSAmir Goldstein return err; 362016b720fSAmir Goldstein 363137ec526SAmir Goldstein temp = ovl_create_temp(indexdir, OVL_CATTR(S_IFDIR | 0)); 364b148cba4SMiklos Szeredi err = PTR_ERR(temp); 365016b720fSAmir Goldstein if (IS_ERR(temp)) 366b148cba4SMiklos Szeredi goto free_name; 367016b720fSAmir Goldstein 368016b720fSAmir Goldstein err = ovl_set_upper_fh(upper, temp); 369016b720fSAmir Goldstein if (err) 370b148cba4SMiklos Szeredi goto out; 371016b720fSAmir Goldstein 372016b720fSAmir Goldstein index = lookup_one_len(name.name, indexdir, name.len); 373016b720fSAmir Goldstein if (IS_ERR(index)) { 374016b720fSAmir Goldstein err = PTR_ERR(index); 375016b720fSAmir Goldstein } else { 376016b720fSAmir Goldstein err = ovl_do_rename(dir, temp, dir, index, 0); 377016b720fSAmir Goldstein dput(index); 378016b720fSAmir Goldstein } 379016b720fSAmir Goldstein out: 380b148cba4SMiklos Szeredi if (err) 381b148cba4SMiklos Szeredi ovl_cleanup(dir, temp); 382016b720fSAmir Goldstein dput(temp); 383b148cba4SMiklos Szeredi free_name: 384016b720fSAmir Goldstein kfree(name.name); 385016b720fSAmir Goldstein return err; 386016b720fSAmir Goldstein } 387016b720fSAmir Goldstein 38823f0ab13SMiklos Szeredi struct ovl_copy_up_ctx { 389a6fb235aSMiklos Szeredi struct dentry *parent; 39023f0ab13SMiklos Szeredi struct dentry *dentry; 39123f0ab13SMiklos Szeredi struct path lowerpath; 39223f0ab13SMiklos Szeredi struct kstat stat; 39323f0ab13SMiklos Szeredi struct kstat pstat; 39423f0ab13SMiklos Szeredi const char *link; 39559be0971SAmir Goldstein struct dentry *destdir; 39659be0971SAmir Goldstein struct qstr destname; 39723f0ab13SMiklos Szeredi struct dentry *workdir; 39859be0971SAmir Goldstein bool origin; 399016b720fSAmir Goldstein bool indexed; 40044d5bf10SVivek Goyal bool metacopy; 40123f0ab13SMiklos Szeredi }; 40223f0ab13SMiklos Szeredi 403f4439de1SAmir Goldstein static int ovl_link_up(struct ovl_copy_up_ctx *c) 404f4439de1SAmir Goldstein { 405f4439de1SAmir Goldstein int err; 406f4439de1SAmir Goldstein struct dentry *upper; 407f4439de1SAmir Goldstein struct dentry *upperdir = ovl_dentry_upper(c->parent); 408f4439de1SAmir Goldstein struct inode *udir = d_inode(upperdir); 409f4439de1SAmir Goldstein 410f4439de1SAmir Goldstein /* Mark parent "impure" because it may now contain non-pure upper */ 411f4439de1SAmir Goldstein err = ovl_set_impure(c->parent, upperdir); 412f4439de1SAmir Goldstein if (err) 413f4439de1SAmir Goldstein return err; 414f4439de1SAmir Goldstein 415f4439de1SAmir Goldstein err = ovl_set_nlink_lower(c->dentry); 416f4439de1SAmir Goldstein if (err) 417f4439de1SAmir Goldstein return err; 418f4439de1SAmir Goldstein 419f4439de1SAmir Goldstein inode_lock_nested(udir, I_MUTEX_PARENT); 420f4439de1SAmir Goldstein upper = lookup_one_len(c->dentry->d_name.name, upperdir, 421f4439de1SAmir Goldstein c->dentry->d_name.len); 422f4439de1SAmir Goldstein err = PTR_ERR(upper); 423f4439de1SAmir Goldstein if (!IS_ERR(upper)) { 4246cf00764SAmir Goldstein err = ovl_do_link(ovl_dentry_upper(c->dentry), udir, upper); 425f4439de1SAmir Goldstein dput(upper); 426f4439de1SAmir Goldstein 427f4439de1SAmir Goldstein if (!err) { 428f4439de1SAmir Goldstein /* Restore timestamps on parent (best effort) */ 429f4439de1SAmir Goldstein ovl_set_timestamps(upperdir, &c->pstat); 430f4439de1SAmir Goldstein ovl_dentry_set_upper_alias(c->dentry); 431f4439de1SAmir Goldstein } 432f4439de1SAmir Goldstein } 433f4439de1SAmir Goldstein inode_unlock(udir); 434aa3ff3c1SAmir Goldstein if (err) 435aa3ff3c1SAmir Goldstein return err; 436aa3ff3c1SAmir Goldstein 437aa3ff3c1SAmir Goldstein err = ovl_set_nlink_upper(c->dentry); 438f4439de1SAmir Goldstein 439f4439de1SAmir Goldstein return err; 440f4439de1SAmir Goldstein } 441f4439de1SAmir Goldstein 44223f0ab13SMiklos Szeredi static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp) 44302209d10SAmir Goldstein { 44402209d10SAmir Goldstein int err; 44502209d10SAmir Goldstein 44623f0ab13SMiklos Szeredi err = ovl_copy_xattr(c->lowerpath.dentry, temp); 44702209d10SAmir Goldstein if (err) 44802209d10SAmir Goldstein return err; 44902209d10SAmir Goldstein 45002209d10SAmir Goldstein /* 45102209d10SAmir Goldstein * Store identifier of lower inode in upper inode xattr to 45202209d10SAmir Goldstein * allow lookup of the copy up origin inode. 45302209d10SAmir Goldstein * 45402209d10SAmir Goldstein * Don't set origin when we are breaking the association with a lower 45502209d10SAmir Goldstein * hard link. 45602209d10SAmir Goldstein */ 45759be0971SAmir Goldstein if (c->origin) { 45823f0ab13SMiklos Szeredi err = ovl_set_origin(c->dentry, c->lowerpath.dentry, temp); 45902209d10SAmir Goldstein if (err) 46002209d10SAmir Goldstein return err; 46102209d10SAmir Goldstein } 46202209d10SAmir Goldstein 46344d5bf10SVivek Goyal if (S_ISREG(c->stat.mode) && !c->metacopy) { 4644f93b426SVivek Goyal struct path upperpath, datapath; 465bd64e575SVivek Goyal 466bd64e575SVivek Goyal ovl_path_upper(c->dentry, &upperpath); 467bd64e575SVivek Goyal BUG_ON(upperpath.dentry != NULL); 468bd64e575SVivek Goyal upperpath.dentry = temp; 469bd64e575SVivek Goyal 4704f93b426SVivek Goyal ovl_path_lowerdata(c->dentry, &datapath); 4714f93b426SVivek Goyal err = ovl_copy_up_data(&datapath, &upperpath, c->stat.size); 472bd64e575SVivek Goyal if (err) 473bd64e575SVivek Goyal return err; 474bd64e575SVivek Goyal } 475bd64e575SVivek Goyal 4760c288874SVivek Goyal if (c->metacopy) { 4770c288874SVivek Goyal err = ovl_check_setxattr(c->dentry, temp, OVL_XATTR_METACOPY, 4780c288874SVivek Goyal NULL, 0, -EOPNOTSUPP); 4790c288874SVivek Goyal if (err) 4800c288874SVivek Goyal return err; 4810c288874SVivek Goyal } 4820c288874SVivek Goyal 483bd64e575SVivek Goyal inode_lock(temp->d_inode); 4840c288874SVivek Goyal if (c->metacopy) 4850c288874SVivek Goyal err = ovl_set_size(temp, &c->stat); 4860c288874SVivek Goyal if (!err) 487bd64e575SVivek Goyal err = ovl_set_attr(temp, &c->stat); 488bd64e575SVivek Goyal inode_unlock(temp->d_inode); 489bd64e575SVivek Goyal 490bd64e575SVivek Goyal return err; 49102209d10SAmir Goldstein } 49202209d10SAmir Goldstein 4936b52243fSMiklos Szeredi struct ovl_cu_creds { 4946b52243fSMiklos Szeredi const struct cred *old; 4956b52243fSMiklos Szeredi struct cred *new; 496b10cdcdcSAmir Goldstein }; 497b10cdcdcSAmir Goldstein 4986b52243fSMiklos Szeredi static int ovl_prep_cu_creds(struct dentry *dentry, struct ovl_cu_creds *cc) 499b10cdcdcSAmir Goldstein { 500b10cdcdcSAmir Goldstein int err; 501b10cdcdcSAmir Goldstein 5026b52243fSMiklos Szeredi cc->old = cc->new = NULL; 5036b52243fSMiklos Szeredi err = security_inode_copy_up(dentry, &cc->new); 5046b52243fSMiklos Szeredi if (err < 0) 505b10cdcdcSAmir Goldstein return err; 5066b52243fSMiklos Szeredi 5076b52243fSMiklos Szeredi if (cc->new) 5086b52243fSMiklos Szeredi cc->old = override_creds(cc->new); 5096b52243fSMiklos Szeredi 5106b52243fSMiklos Szeredi return 0; 5116b52243fSMiklos Szeredi } 5126b52243fSMiklos Szeredi 5136b52243fSMiklos Szeredi static void ovl_revert_cu_creds(struct ovl_cu_creds *cc) 5146b52243fSMiklos Szeredi { 5156b52243fSMiklos Szeredi if (cc->new) { 5166b52243fSMiklos Szeredi revert_creds(cc->old); 5176b52243fSMiklos Szeredi put_cred(cc->new); 5186b52243fSMiklos Szeredi } 519b10cdcdcSAmir Goldstein } 520b10cdcdcSAmir Goldstein 521b10cdcdcSAmir Goldstein /* 522b10cdcdcSAmir Goldstein * Copyup using workdir to prepare temp file. Used when copying up directories, 523b10cdcdcSAmir Goldstein * special files or when upper fs doesn't support O_TMPFILE. 524b10cdcdcSAmir Goldstein */ 525b10cdcdcSAmir Goldstein static int ovl_copy_up_workdir(struct ovl_copy_up_ctx *c) 526b10cdcdcSAmir Goldstein { 527b79e05aaSAmir Goldstein struct inode *inode; 5286b52243fSMiklos Szeredi struct inode *udir = d_inode(c->destdir), *wdir = d_inode(c->workdir); 5296b52243fSMiklos Szeredi struct dentry *temp, *upper; 5306b52243fSMiklos Szeredi struct ovl_cu_creds cc; 5317d90b853SMiklos Szeredi int err; 5326b52243fSMiklos Szeredi struct ovl_cattr cattr = { 5336b52243fSMiklos Szeredi /* Can't properly set mode on creation because of the umask */ 5346b52243fSMiklos Szeredi .mode = c->stat.mode & S_IFMT, 5356b52243fSMiklos Szeredi .rdev = c->stat.rdev, 5366b52243fSMiklos Szeredi .link = c->link 5376b52243fSMiklos Szeredi }; 5387d90b853SMiklos Szeredi 539b10cdcdcSAmir Goldstein err = ovl_lock_rename_workdir(c->workdir, c->destdir); 540b10cdcdcSAmir Goldstein if (err) 541b10cdcdcSAmir Goldstein return err; 542b10cdcdcSAmir Goldstein 5436b52243fSMiklos Szeredi err = ovl_prep_cu_creds(c->dentry, &cc); 5446b52243fSMiklos Szeredi if (err) 5456b52243fSMiklos Szeredi goto unlock; 5466b52243fSMiklos Szeredi 5476b52243fSMiklos Szeredi temp = ovl_create_temp(c->workdir, &cattr); 5486b52243fSMiklos Szeredi ovl_revert_cu_creds(&cc); 5496b52243fSMiklos Szeredi 550b10cdcdcSAmir Goldstein err = PTR_ERR(temp); 551b10cdcdcSAmir Goldstein if (IS_ERR(temp)) 552b10cdcdcSAmir Goldstein goto unlock; 553b10cdcdcSAmir Goldstein 554b10cdcdcSAmir Goldstein err = ovl_copy_up_inode(c, temp); 555b10cdcdcSAmir Goldstein if (err) 556b10cdcdcSAmir Goldstein goto cleanup; 557b10cdcdcSAmir Goldstein 558b10cdcdcSAmir Goldstein if (S_ISDIR(c->stat.mode) && c->indexed) { 559b10cdcdcSAmir Goldstein err = ovl_create_index(c->dentry, c->lowerpath.dentry, temp); 560b10cdcdcSAmir Goldstein if (err) 561b10cdcdcSAmir Goldstein goto cleanup; 562b10cdcdcSAmir Goldstein } 563b10cdcdcSAmir Goldstein 5646b52243fSMiklos Szeredi upper = lookup_one_len(c->destname.name, c->destdir, c->destname.len); 5656b52243fSMiklos Szeredi err = PTR_ERR(upper); 5666b52243fSMiklos Szeredi if (IS_ERR(upper)) 5676b52243fSMiklos Szeredi goto cleanup; 5686b52243fSMiklos Szeredi 5696b52243fSMiklos Szeredi err = ovl_do_rename(wdir, temp, udir, upper, 0); 5706b52243fSMiklos Szeredi dput(upper); 571b10cdcdcSAmir Goldstein if (err) 572b10cdcdcSAmir Goldstein goto cleanup; 573b10cdcdcSAmir Goldstein 574b10cdcdcSAmir Goldstein if (!c->metacopy) 575b10cdcdcSAmir Goldstein ovl_set_upperdata(d_inode(c->dentry)); 576b10cdcdcSAmir Goldstein inode = d_inode(c->dentry); 5776b52243fSMiklos Szeredi ovl_inode_update(inode, temp); 578b10cdcdcSAmir Goldstein if (S_ISDIR(inode->i_mode)) 579b10cdcdcSAmir Goldstein ovl_set_flag(OVL_WHITEOUTS, inode); 580b10cdcdcSAmir Goldstein unlock: 581b10cdcdcSAmir Goldstein unlock_rename(c->workdir, c->destdir); 582b10cdcdcSAmir Goldstein 583b10cdcdcSAmir Goldstein return err; 584b10cdcdcSAmir Goldstein 585b10cdcdcSAmir Goldstein cleanup: 5866b52243fSMiklos Szeredi ovl_cleanup(wdir, temp); 5876b52243fSMiklos Szeredi dput(temp); 588b10cdcdcSAmir Goldstein goto unlock; 589b10cdcdcSAmir Goldstein } 590b10cdcdcSAmir Goldstein 591b10cdcdcSAmir Goldstein /* Copyup using O_TMPFILE which does not require cross dir locking */ 592b10cdcdcSAmir Goldstein static int ovl_copy_up_tmpfile(struct ovl_copy_up_ctx *c) 593b10cdcdcSAmir Goldstein { 5946b52243fSMiklos Szeredi struct inode *udir = d_inode(c->destdir); 5956b52243fSMiklos Szeredi struct dentry *temp, *upper; 5966b52243fSMiklos Szeredi struct ovl_cu_creds cc; 597b10cdcdcSAmir Goldstein int err; 598b10cdcdcSAmir Goldstein 5996b52243fSMiklos Szeredi err = ovl_prep_cu_creds(c->dentry, &cc); 6006b52243fSMiklos Szeredi if (err) 6016b52243fSMiklos Szeredi return err; 6026b52243fSMiklos Szeredi 6036b52243fSMiklos Szeredi temp = ovl_do_tmpfile(c->workdir, c->stat.mode); 6046b52243fSMiklos Szeredi ovl_revert_cu_creds(&cc); 6056b52243fSMiklos Szeredi 606b148cba4SMiklos Szeredi if (IS_ERR(temp)) 607b148cba4SMiklos Szeredi return PTR_ERR(temp); 608e9be9d5eSMiklos Szeredi 60923f0ab13SMiklos Szeredi err = ovl_copy_up_inode(c, temp); 610e9be9d5eSMiklos Szeredi if (err) 6116b52243fSMiklos Szeredi goto out_dput; 6123a1e819bSAmir Goldstein 6136b52243fSMiklos Szeredi inode_lock_nested(udir, I_MUTEX_PARENT); 6146b52243fSMiklos Szeredi 6156b52243fSMiklos Szeredi upper = lookup_one_len(c->destname.name, c->destdir, c->destname.len); 6166b52243fSMiklos Szeredi err = PTR_ERR(upper); 6176b52243fSMiklos Szeredi if (!IS_ERR(upper)) { 6186b52243fSMiklos Szeredi err = ovl_do_link(temp, udir, upper); 6196b52243fSMiklos Szeredi dput(upper); 6206b52243fSMiklos Szeredi } 6216b52243fSMiklos Szeredi inode_unlock(udir); 6226b52243fSMiklos Szeredi 623e9be9d5eSMiklos Szeredi if (err) 6246b52243fSMiklos Szeredi goto out_dput; 625e9be9d5eSMiklos Szeredi 6260c288874SVivek Goyal if (!c->metacopy) 6270c288874SVivek Goyal ovl_set_upperdata(d_inode(c->dentry)); 6286b52243fSMiklos Szeredi ovl_inode_update(d_inode(c->dentry), temp); 629b79e05aaSAmir Goldstein 6306b52243fSMiklos Szeredi return 0; 6316b52243fSMiklos Szeredi 6326b52243fSMiklos Szeredi out_dput: 633e85f82ffSMiklos Szeredi dput(temp); 634e9be9d5eSMiklos Szeredi return err; 635e9be9d5eSMiklos Szeredi } 636e9be9d5eSMiklos Szeredi 637e9be9d5eSMiklos Szeredi /* 638e9be9d5eSMiklos Szeredi * Copy up a single dentry 639e9be9d5eSMiklos Szeredi * 640a6c60655SMiklos Szeredi * All renames start with copy up of source if necessary. The actual 641a6c60655SMiklos Szeredi * rename will only proceed once the copy up was successful. Copy up uses 642a6c60655SMiklos Szeredi * upper parent i_mutex for exclusion. Since rename can change d_parent it 643a6c60655SMiklos Szeredi * is possible that the copy up will lock the old parent. At that point 644a6c60655SMiklos Szeredi * the file will have already been copied up anyway. 645e9be9d5eSMiklos Szeredi */ 646a6fb235aSMiklos Szeredi static int ovl_do_copy_up(struct ovl_copy_up_ctx *c) 647e9be9d5eSMiklos Szeredi { 648e9be9d5eSMiklos Szeredi int err; 64923f0ab13SMiklos Szeredi struct ovl_fs *ofs = c->dentry->d_sb->s_fs_info; 650016b720fSAmir Goldstein bool to_index = false; 65159be0971SAmir Goldstein 652016b720fSAmir Goldstein /* 653016b720fSAmir Goldstein * Indexed non-dir is copied up directly to the index entry and then 654016b720fSAmir Goldstein * hardlinked to upper dir. Indexed dir is copied up to indexdir, 655016b720fSAmir Goldstein * then index entry is created and then copied up dir installed. 656016b720fSAmir Goldstein * Copying dir up to indexdir instead of workdir simplifies locking. 657016b720fSAmir Goldstein */ 658016b720fSAmir Goldstein if (ovl_need_index(c->dentry)) { 659016b720fSAmir Goldstein c->indexed = true; 660016b720fSAmir Goldstein if (S_ISDIR(c->stat.mode)) 661016b720fSAmir Goldstein c->workdir = ovl_indexdir(c->dentry->d_sb); 662016b720fSAmir Goldstein else 663016b720fSAmir Goldstein to_index = true; 664016b720fSAmir Goldstein } 665016b720fSAmir Goldstein 666016b720fSAmir Goldstein if (S_ISDIR(c->stat.mode) || c->stat.nlink == 1 || to_index) 66759be0971SAmir Goldstein c->origin = true; 66859be0971SAmir Goldstein 669016b720fSAmir Goldstein if (to_index) { 67059be0971SAmir Goldstein c->destdir = ovl_indexdir(c->dentry->d_sb); 67159be0971SAmir Goldstein err = ovl_get_index_name(c->lowerpath.dentry, &c->destname); 672f3a15685SAmir Goldstein if (err) 673f3a15685SAmir Goldstein return err; 674aa3ff3c1SAmir Goldstein } else if (WARN_ON(!c->parent)) { 675aa3ff3c1SAmir Goldstein /* Disconnected dentry must be copied up to index dir */ 676aa3ff3c1SAmir Goldstein return -EIO; 67759be0971SAmir Goldstein } else { 67859be0971SAmir Goldstein /* 67959be0971SAmir Goldstein * Mark parent "impure" because it may now contain non-pure 68059be0971SAmir Goldstein * upper 68159be0971SAmir Goldstein */ 68259be0971SAmir Goldstein err = ovl_set_impure(c->parent, c->destdir); 68359be0971SAmir Goldstein if (err) 68459be0971SAmir Goldstein return err; 68559be0971SAmir Goldstein } 686f3a15685SAmir Goldstein 68701ad3eb8SAmir Goldstein /* Should we copyup with O_TMPFILE or with workdir? */ 688b10cdcdcSAmir Goldstein if (S_ISREG(c->stat.mode) && ofs->tmpfile) 689b10cdcdcSAmir Goldstein err = ovl_copy_up_tmpfile(c); 690b10cdcdcSAmir Goldstein else 691b10cdcdcSAmir Goldstein err = ovl_copy_up_workdir(c); 692aa3ff3c1SAmir Goldstein if (err) 693aa3ff3c1SAmir Goldstein goto out; 694aa3ff3c1SAmir Goldstein 695aa3ff3c1SAmir Goldstein if (c->indexed) 69659be0971SAmir Goldstein ovl_set_flag(OVL_INDEX, d_inode(c->dentry)); 697016b720fSAmir Goldstein 698016b720fSAmir Goldstein if (to_index) { 699aa3ff3c1SAmir Goldstein /* Initialize nlink for copy up of disconnected dentry */ 700aa3ff3c1SAmir Goldstein err = ovl_set_nlink_upper(c->dentry); 701aa3ff3c1SAmir Goldstein } else { 70259be0971SAmir Goldstein struct inode *udir = d_inode(c->destdir); 70359be0971SAmir Goldstein 70459be0971SAmir Goldstein /* Restore timestamps on parent (best effort) */ 70559be0971SAmir Goldstein inode_lock(udir); 70659be0971SAmir Goldstein ovl_set_timestamps(c->destdir, &c->pstat); 70759be0971SAmir Goldstein inode_unlock(udir); 70859be0971SAmir Goldstein 70959be0971SAmir Goldstein ovl_dentry_set_upper_alias(c->dentry); 710fd210b7dSMiklos Szeredi } 711a6fb235aSMiklos Szeredi 712aa3ff3c1SAmir Goldstein out: 713aa3ff3c1SAmir Goldstein if (to_index) 714aa3ff3c1SAmir Goldstein kfree(c->destname.name); 715a6fb235aSMiklos Szeredi return err; 716a6fb235aSMiklos Szeredi } 717a6fb235aSMiklos Szeredi 71844d5bf10SVivek Goyal static bool ovl_need_meta_copy_up(struct dentry *dentry, umode_t mode, 71944d5bf10SVivek Goyal int flags) 72044d5bf10SVivek Goyal { 72144d5bf10SVivek Goyal struct ovl_fs *ofs = dentry->d_sb->s_fs_info; 72244d5bf10SVivek Goyal 72344d5bf10SVivek Goyal if (!ofs->config.metacopy) 72444d5bf10SVivek Goyal return false; 72544d5bf10SVivek Goyal 72644d5bf10SVivek Goyal if (!S_ISREG(mode)) 72744d5bf10SVivek Goyal return false; 72844d5bf10SVivek Goyal 72944d5bf10SVivek Goyal if (flags && ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC))) 73044d5bf10SVivek Goyal return false; 73144d5bf10SVivek Goyal 73244d5bf10SVivek Goyal return true; 73344d5bf10SVivek Goyal } 73444d5bf10SVivek Goyal 7350c288874SVivek Goyal /* Copy up data of an inode which was copied up metadata only in the past. */ 7360c288874SVivek Goyal static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c) 7370c288874SVivek Goyal { 7384f93b426SVivek Goyal struct path upperpath, datapath; 7390c288874SVivek Goyal int err; 7400c288874SVivek Goyal 7410c288874SVivek Goyal ovl_path_upper(c->dentry, &upperpath); 7420c288874SVivek Goyal if (WARN_ON(upperpath.dentry == NULL)) 7430c288874SVivek Goyal return -EIO; 7440c288874SVivek Goyal 7454f93b426SVivek Goyal ovl_path_lowerdata(c->dentry, &datapath); 7464f93b426SVivek Goyal if (WARN_ON(datapath.dentry == NULL)) 7474f93b426SVivek Goyal return -EIO; 7484f93b426SVivek Goyal 7494f93b426SVivek Goyal err = ovl_copy_up_data(&datapath, &upperpath, c->stat.size); 7500c288874SVivek Goyal if (err) 7510c288874SVivek Goyal return err; 7520c288874SVivek Goyal 7530c288874SVivek Goyal err = vfs_removexattr(upperpath.dentry, OVL_XATTR_METACOPY); 7540c288874SVivek Goyal if (err) 7550c288874SVivek Goyal return err; 7560c288874SVivek Goyal 7570c288874SVivek Goyal ovl_set_upperdata(d_inode(c->dentry)); 7580c288874SVivek Goyal return err; 7590c288874SVivek Goyal } 7600c288874SVivek Goyal 761a6fb235aSMiklos Szeredi static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, 762a6fb235aSMiklos Szeredi int flags) 763a6fb235aSMiklos Szeredi { 764a6fb235aSMiklos Szeredi int err; 765a6fb235aSMiklos Szeredi DEFINE_DELAYED_CALL(done); 766a6fb235aSMiklos Szeredi struct path parentpath; 767a6fb235aSMiklos Szeredi struct ovl_copy_up_ctx ctx = { 768a6fb235aSMiklos Szeredi .parent = parent, 769a6fb235aSMiklos Szeredi .dentry = dentry, 770a6fb235aSMiklos Szeredi .workdir = ovl_workdir(dentry), 771a6fb235aSMiklos Szeredi }; 772a6fb235aSMiklos Szeredi 773a6fb235aSMiklos Szeredi if (WARN_ON(!ctx.workdir)) 774a6fb235aSMiklos Szeredi return -EROFS; 775a6fb235aSMiklos Szeredi 776a6fb235aSMiklos Szeredi ovl_path_lower(dentry, &ctx.lowerpath); 777a6fb235aSMiklos Szeredi err = vfs_getattr(&ctx.lowerpath, &ctx.stat, 778a6fb235aSMiklos Szeredi STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT); 779a6fb235aSMiklos Szeredi if (err) 780a6fb235aSMiklos Szeredi return err; 781a6fb235aSMiklos Szeredi 78244d5bf10SVivek Goyal ctx.metacopy = ovl_need_meta_copy_up(dentry, ctx.stat.mode, flags); 78344d5bf10SVivek Goyal 784aa3ff3c1SAmir Goldstein if (parent) { 785a6fb235aSMiklos Szeredi ovl_path_upper(parent, &parentpath); 78659be0971SAmir Goldstein ctx.destdir = parentpath.dentry; 78759be0971SAmir Goldstein ctx.destname = dentry->d_name; 788a6fb235aSMiklos Szeredi 789a6fb235aSMiklos Szeredi err = vfs_getattr(&parentpath, &ctx.pstat, 790aa3ff3c1SAmir Goldstein STATX_ATIME | STATX_MTIME, 791aa3ff3c1SAmir Goldstein AT_STATX_SYNC_AS_STAT); 792a6fb235aSMiklos Szeredi if (err) 793a6fb235aSMiklos Szeredi return err; 794aa3ff3c1SAmir Goldstein } 795a6fb235aSMiklos Szeredi 796a6fb235aSMiklos Szeredi /* maybe truncate regular file. this has no effect on dirs */ 797a6fb235aSMiklos Szeredi if (flags & O_TRUNC) 798a6fb235aSMiklos Szeredi ctx.stat.size = 0; 799a6fb235aSMiklos Szeredi 800a6fb235aSMiklos Szeredi if (S_ISLNK(ctx.stat.mode)) { 801a6fb235aSMiklos Szeredi ctx.link = vfs_get_link(ctx.lowerpath.dentry, &done); 802a6fb235aSMiklos Szeredi if (IS_ERR(ctx.link)) 803a6fb235aSMiklos Szeredi return PTR_ERR(ctx.link); 804a6fb235aSMiklos Szeredi } 805a6fb235aSMiklos Szeredi 8060c288874SVivek Goyal err = ovl_copy_up_start(dentry, flags); 807fd210b7dSMiklos Szeredi /* err < 0: interrupted, err > 0: raced with another copy-up */ 808fd210b7dSMiklos Szeredi if (unlikely(err)) { 809fd210b7dSMiklos Szeredi if (err > 0) 810fd210b7dSMiklos Szeredi err = 0; 811fd210b7dSMiklos Szeredi } else { 81259be0971SAmir Goldstein if (!ovl_dentry_upper(dentry)) 813a6fb235aSMiklos Szeredi err = ovl_do_copy_up(&ctx); 814aa3ff3c1SAmir Goldstein if (!err && parent && !ovl_dentry_has_upper_alias(dentry)) 815f4439de1SAmir Goldstein err = ovl_link_up(&ctx); 8160c288874SVivek Goyal if (!err && ovl_dentry_needs_data_copy_up_locked(dentry, flags)) 8170c288874SVivek Goyal err = ovl_copy_up_meta_inode_data(&ctx); 818fd210b7dSMiklos Szeredi ovl_copy_up_end(dentry); 819fd210b7dSMiklos Szeredi } 8207764235bSMiklos Szeredi do_delayed_call(&done); 821e9be9d5eSMiklos Szeredi 822e9be9d5eSMiklos Szeredi return err; 823e9be9d5eSMiklos Szeredi } 824e9be9d5eSMiklos Szeredi 8259aba6521SAmir Goldstein int ovl_copy_up_flags(struct dentry *dentry, int flags) 826e9be9d5eSMiklos Szeredi { 8278eac98b8SVivek Goyal int err = 0; 8288eac98b8SVivek Goyal const struct cred *old_cred = ovl_override_creds(dentry->d_sb); 829aa3ff3c1SAmir Goldstein bool disconnected = (dentry->d_flags & DCACHE_DISCONNECTED); 830aa3ff3c1SAmir Goldstein 831aa3ff3c1SAmir Goldstein /* 832aa3ff3c1SAmir Goldstein * With NFS export, copy up can get called for a disconnected non-dir. 833aa3ff3c1SAmir Goldstein * In this case, we will copy up lower inode to index dir without 834aa3ff3c1SAmir Goldstein * linking it to upper dir. 835aa3ff3c1SAmir Goldstein */ 836aa3ff3c1SAmir Goldstein if (WARN_ON(disconnected && d_is_dir(dentry))) 837aa3ff3c1SAmir Goldstein return -EIO; 838e9be9d5eSMiklos Szeredi 839e9be9d5eSMiklos Szeredi while (!err) { 840e9be9d5eSMiklos Szeredi struct dentry *next; 841aa3ff3c1SAmir Goldstein struct dentry *parent = NULL; 842e9be9d5eSMiklos Szeredi 8430c288874SVivek Goyal if (ovl_already_copied_up(dentry, flags)) 844e9be9d5eSMiklos Szeredi break; 845e9be9d5eSMiklos Szeredi 846e9be9d5eSMiklos Szeredi next = dget(dentry); 847e9be9d5eSMiklos Szeredi /* find the topmost dentry not yet copied up */ 848aa3ff3c1SAmir Goldstein for (; !disconnected;) { 849e9be9d5eSMiklos Szeredi parent = dget_parent(next); 850e9be9d5eSMiklos Szeredi 85159be0971SAmir Goldstein if (ovl_dentry_upper(parent)) 852e9be9d5eSMiklos Szeredi break; 853e9be9d5eSMiklos Szeredi 854e9be9d5eSMiklos Szeredi dput(next); 855e9be9d5eSMiklos Szeredi next = parent; 856e9be9d5eSMiklos Szeredi } 857e9be9d5eSMiklos Szeredi 858a6fb235aSMiklos Szeredi err = ovl_copy_up_one(parent, next, flags); 859e9be9d5eSMiklos Szeredi 860e9be9d5eSMiklos Szeredi dput(parent); 861e9be9d5eSMiklos Szeredi dput(next); 862e9be9d5eSMiklos Szeredi } 8638eac98b8SVivek Goyal revert_creds(old_cred); 864e9be9d5eSMiklos Szeredi 865e9be9d5eSMiklos Szeredi return err; 866e9be9d5eSMiklos Szeredi } 8679aba6521SAmir Goldstein 868d6eac039SVivek Goyal static bool ovl_open_need_copy_up(struct dentry *dentry, int flags) 869d6eac039SVivek Goyal { 870d6eac039SVivek Goyal /* Copy up of disconnected dentry does not set upper alias */ 8710c288874SVivek Goyal if (ovl_already_copied_up(dentry, flags)) 872d6eac039SVivek Goyal return false; 873d6eac039SVivek Goyal 874d6eac039SVivek Goyal if (special_file(d_inode(dentry)->i_mode)) 875d6eac039SVivek Goyal return false; 876d6eac039SVivek Goyal 8770c288874SVivek Goyal if (!ovl_open_flags_need_copy_up(flags)) 878d6eac039SVivek Goyal return false; 879d6eac039SVivek Goyal 880d6eac039SVivek Goyal return true; 881d6eac039SVivek Goyal } 882d6eac039SVivek Goyal 883d6eac039SVivek Goyal int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags) 884d6eac039SVivek Goyal { 885d6eac039SVivek Goyal int err = 0; 886d6eac039SVivek Goyal 887d6eac039SVivek Goyal if (ovl_open_need_copy_up(dentry, file_flags)) { 888d6eac039SVivek Goyal err = ovl_want_write(dentry); 889d6eac039SVivek Goyal if (!err) { 890d6eac039SVivek Goyal err = ovl_copy_up_flags(dentry, file_flags); 891d6eac039SVivek Goyal ovl_drop_write(dentry); 892d6eac039SVivek Goyal } 893d6eac039SVivek Goyal } 894d6eac039SVivek Goyal 895d6eac039SVivek Goyal return err; 896d6eac039SVivek Goyal } 897d6eac039SVivek Goyal 898d1e6f6a9SVivek Goyal int ovl_copy_up_with_data(struct dentry *dentry) 899d1e6f6a9SVivek Goyal { 900d1e6f6a9SVivek Goyal return ovl_copy_up_flags(dentry, O_WRONLY); 901d1e6f6a9SVivek Goyal } 902d1e6f6a9SVivek Goyal 9039aba6521SAmir Goldstein int ovl_copy_up(struct dentry *dentry) 9049aba6521SAmir Goldstein { 9059aba6521SAmir Goldstein return ovl_copy_up_flags(dentry, 0); 9069aba6521SAmir Goldstein } 907