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*param) 29fb5bb2c3SDavid Howells { 30670c2324SMiklos Szeredi pr_warn("overlayfs: \"check_copy_up\" module option is obsolete\n"); 31fb5bb2c3SDavid Howells return 0; 32fb5bb2c3SDavid Howells } 33fb5bb2c3SDavid Howells 34670c2324SMiklos Szeredi static int ovl_ccup_get(char *buf, const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 */ 1442ea98466SAmir Goldstein error = vfs_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; 39823f0ab13SMiklos Szeredi bool tmpfile; 39959be0971SAmir Goldstein bool origin; 400016b720fSAmir Goldstein bool indexed; 40144d5bf10SVivek Goyal bool metacopy; 40223f0ab13SMiklos Szeredi }; 40323f0ab13SMiklos Szeredi 404f4439de1SAmir Goldstein static int ovl_link_up(struct ovl_copy_up_ctx *c) 405f4439de1SAmir Goldstein { 406f4439de1SAmir Goldstein int err; 407f4439de1SAmir Goldstein struct dentry *upper; 408f4439de1SAmir Goldstein struct dentry *upperdir = ovl_dentry_upper(c->parent); 409f4439de1SAmir Goldstein struct inode *udir = d_inode(upperdir); 410f4439de1SAmir Goldstein 411f4439de1SAmir Goldstein /* Mark parent "impure" because it may now contain non-pure upper */ 412f4439de1SAmir Goldstein err = ovl_set_impure(c->parent, upperdir); 413f4439de1SAmir Goldstein if (err) 414f4439de1SAmir Goldstein return err; 415f4439de1SAmir Goldstein 416f4439de1SAmir Goldstein err = ovl_set_nlink_lower(c->dentry); 417f4439de1SAmir Goldstein if (err) 418f4439de1SAmir Goldstein return err; 419f4439de1SAmir Goldstein 420f4439de1SAmir Goldstein inode_lock_nested(udir, I_MUTEX_PARENT); 421f4439de1SAmir Goldstein upper = lookup_one_len(c->dentry->d_name.name, upperdir, 422f4439de1SAmir Goldstein c->dentry->d_name.len); 423f4439de1SAmir Goldstein err = PTR_ERR(upper); 424f4439de1SAmir Goldstein if (!IS_ERR(upper)) { 4256cf00764SAmir Goldstein err = ovl_do_link(ovl_dentry_upper(c->dentry), udir, upper); 426f4439de1SAmir Goldstein dput(upper); 427f4439de1SAmir Goldstein 428f4439de1SAmir Goldstein if (!err) { 429f4439de1SAmir Goldstein /* Restore timestamps on parent (best effort) */ 430f4439de1SAmir Goldstein ovl_set_timestamps(upperdir, &c->pstat); 431f4439de1SAmir Goldstein ovl_dentry_set_upper_alias(c->dentry); 432f4439de1SAmir Goldstein } 433f4439de1SAmir Goldstein } 434f4439de1SAmir Goldstein inode_unlock(udir); 435aa3ff3c1SAmir Goldstein if (err) 436aa3ff3c1SAmir Goldstein return err; 437aa3ff3c1SAmir Goldstein 438aa3ff3c1SAmir Goldstein err = ovl_set_nlink_upper(c->dentry); 439f4439de1SAmir Goldstein 440f4439de1SAmir Goldstein return err; 441f4439de1SAmir Goldstein } 442f4439de1SAmir Goldstein 44323f0ab13SMiklos Szeredi static int ovl_install_temp(struct ovl_copy_up_ctx *c, struct dentry *temp, 44423f0ab13SMiklos Szeredi struct dentry **newdentry) 44515932c41SAmir Goldstein { 44615932c41SAmir Goldstein int err; 44715932c41SAmir Goldstein struct dentry *upper; 44859be0971SAmir Goldstein struct inode *udir = d_inode(c->destdir); 44915932c41SAmir Goldstein 45059be0971SAmir Goldstein upper = lookup_one_len(c->destname.name, c->destdir, c->destname.len); 45115932c41SAmir Goldstein if (IS_ERR(upper)) 45215932c41SAmir Goldstein return PTR_ERR(upper); 45315932c41SAmir Goldstein 45423f0ab13SMiklos Szeredi if (c->tmpfile) 4556cf00764SAmir Goldstein err = ovl_do_link(temp, udir, upper); 45615932c41SAmir Goldstein else 45723f0ab13SMiklos Szeredi err = ovl_do_rename(d_inode(c->workdir), temp, udir, upper, 0); 45815932c41SAmir Goldstein 45959be0971SAmir Goldstein if (!err) 46023f0ab13SMiklos Szeredi *newdentry = dget(c->tmpfile ? upper : temp); 46115932c41SAmir Goldstein dput(upper); 46215932c41SAmir Goldstein 46315932c41SAmir Goldstein return err; 46415932c41SAmir Goldstein } 46515932c41SAmir Goldstein 466b148cba4SMiklos Szeredi static struct dentry *ovl_get_tmpfile(struct ovl_copy_up_ctx *c) 467e9be9d5eSMiklos Szeredi { 468e9be9d5eSMiklos Szeredi int err; 4697d90b853SMiklos Szeredi struct dentry *temp; 470d8ad8b49SVivek Goyal const struct cred *old_creds = NULL; 471d8ad8b49SVivek Goyal struct cred *new_creds = NULL; 472471ec5dcSAmir Goldstein struct ovl_cattr cattr = { 47332a3d848SAl Viro /* Can't properly set mode on creation because of the umask */ 47423f0ab13SMiklos Szeredi .mode = c->stat.mode & S_IFMT, 47523f0ab13SMiklos Szeredi .rdev = c->stat.rdev, 47623f0ab13SMiklos Szeredi .link = c->link 47732a3d848SAl Viro }; 478e9be9d5eSMiklos Szeredi 47923f0ab13SMiklos Szeredi err = security_inode_copy_up(c->dentry, &new_creds); 480b148cba4SMiklos Szeredi temp = ERR_PTR(err); 481d8ad8b49SVivek Goyal if (err < 0) 482e85f82ffSMiklos Szeredi goto out; 483d8ad8b49SVivek Goyal 484d8ad8b49SVivek Goyal if (new_creds) 485d8ad8b49SVivek Goyal old_creds = override_creds(new_creds); 486d8ad8b49SVivek Goyal 487137ec526SAmir Goldstein if (c->tmpfile) 48823f0ab13SMiklos Szeredi temp = ovl_do_tmpfile(c->workdir, c->stat.mode); 489137ec526SAmir Goldstein else 490137ec526SAmir Goldstein temp = ovl_create_temp(c->workdir, &cattr); 4917d90b853SMiklos Szeredi out: 492d8ad8b49SVivek Goyal if (new_creds) { 493d8ad8b49SVivek Goyal revert_creds(old_creds); 494d8ad8b49SVivek Goyal put_cred(new_creds); 495d8ad8b49SVivek Goyal } 496d8ad8b49SVivek Goyal 497b148cba4SMiklos Szeredi return temp; 4987d90b853SMiklos Szeredi } 4997d90b853SMiklos Szeredi 50023f0ab13SMiklos Szeredi static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp) 50102209d10SAmir Goldstein { 50202209d10SAmir Goldstein int err; 50302209d10SAmir Goldstein 50423f0ab13SMiklos Szeredi err = ovl_copy_xattr(c->lowerpath.dentry, temp); 50502209d10SAmir Goldstein if (err) 50602209d10SAmir Goldstein return err; 50702209d10SAmir Goldstein 50802209d10SAmir Goldstein /* 50902209d10SAmir Goldstein * Store identifier of lower inode in upper inode xattr to 51002209d10SAmir Goldstein * allow lookup of the copy up origin inode. 51102209d10SAmir Goldstein * 51202209d10SAmir Goldstein * Don't set origin when we are breaking the association with a lower 51302209d10SAmir Goldstein * hard link. 51402209d10SAmir Goldstein */ 51559be0971SAmir Goldstein if (c->origin) { 51623f0ab13SMiklos Szeredi err = ovl_set_origin(c->dentry, c->lowerpath.dentry, temp); 51702209d10SAmir Goldstein if (err) 51802209d10SAmir Goldstein return err; 51902209d10SAmir Goldstein } 52002209d10SAmir Goldstein 52144d5bf10SVivek Goyal if (S_ISREG(c->stat.mode) && !c->metacopy) { 522bd64e575SVivek Goyal struct path upperpath; 523bd64e575SVivek Goyal 524bd64e575SVivek Goyal ovl_path_upper(c->dentry, &upperpath); 525bd64e575SVivek Goyal BUG_ON(upperpath.dentry != NULL); 526bd64e575SVivek Goyal upperpath.dentry = temp; 527bd64e575SVivek Goyal 528bd64e575SVivek Goyal err = ovl_copy_up_data(&c->lowerpath, &upperpath, c->stat.size); 529bd64e575SVivek Goyal if (err) 530bd64e575SVivek Goyal return err; 531bd64e575SVivek Goyal } 532bd64e575SVivek Goyal 5330c288874SVivek Goyal if (c->metacopy) { 5340c288874SVivek Goyal err = ovl_check_setxattr(c->dentry, temp, OVL_XATTR_METACOPY, 5350c288874SVivek Goyal NULL, 0, -EOPNOTSUPP); 5360c288874SVivek Goyal if (err) 5370c288874SVivek Goyal return err; 5380c288874SVivek Goyal } 5390c288874SVivek Goyal 540bd64e575SVivek Goyal inode_lock(temp->d_inode); 5410c288874SVivek Goyal if (c->metacopy) 5420c288874SVivek Goyal err = ovl_set_size(temp, &c->stat); 5430c288874SVivek Goyal if (!err) 544bd64e575SVivek Goyal err = ovl_set_attr(temp, &c->stat); 545bd64e575SVivek Goyal inode_unlock(temp->d_inode); 546bd64e575SVivek Goyal 547bd64e575SVivek Goyal return err; 54802209d10SAmir Goldstein } 54902209d10SAmir Goldstein 55023f0ab13SMiklos Szeredi static int ovl_copy_up_locked(struct ovl_copy_up_ctx *c) 5517d90b853SMiklos Szeredi { 55259be0971SAmir Goldstein struct inode *udir = c->destdir->d_inode; 553b79e05aaSAmir Goldstein struct inode *inode; 5547d90b853SMiklos Szeredi struct dentry *newdentry = NULL; 555b148cba4SMiklos Szeredi struct dentry *temp; 5567d90b853SMiklos Szeredi int err; 5577d90b853SMiklos Szeredi 558b148cba4SMiklos Szeredi temp = ovl_get_tmpfile(c); 559b148cba4SMiklos Szeredi if (IS_ERR(temp)) 560b148cba4SMiklos Szeredi return PTR_ERR(temp); 561e9be9d5eSMiklos Szeredi 56223f0ab13SMiklos Szeredi err = ovl_copy_up_inode(c, temp); 563e9be9d5eSMiklos Szeredi if (err) 564b148cba4SMiklos Szeredi goto out; 5653a1e819bSAmir Goldstein 566016b720fSAmir Goldstein if (S_ISDIR(c->stat.mode) && c->indexed) { 567016b720fSAmir Goldstein err = ovl_create_index(c->dentry, c->lowerpath.dentry, temp); 568016b720fSAmir Goldstein if (err) 569b148cba4SMiklos Szeredi goto out; 570016b720fSAmir Goldstein } 571016b720fSAmir Goldstein 57223f0ab13SMiklos Szeredi if (c->tmpfile) { 57315932c41SAmir Goldstein inode_lock_nested(udir, I_MUTEX_PARENT); 57423f0ab13SMiklos Szeredi err = ovl_install_temp(c, temp, &newdentry); 57515932c41SAmir Goldstein inode_unlock(udir); 57615932c41SAmir Goldstein } else { 57723f0ab13SMiklos Szeredi err = ovl_install_temp(c, temp, &newdentry); 578e85f82ffSMiklos Szeredi } 579e9be9d5eSMiklos Szeredi if (err) 580b148cba4SMiklos Szeredi goto out; 581e9be9d5eSMiklos Szeredi 5820c288874SVivek Goyal if (!c->metacopy) 5830c288874SVivek Goyal ovl_set_upperdata(d_inode(c->dentry)); 584b79e05aaSAmir Goldstein inode = d_inode(c->dentry); 585b79e05aaSAmir Goldstein ovl_inode_update(inode, newdentry); 586b79e05aaSAmir Goldstein if (S_ISDIR(inode->i_mode)) 587b79e05aaSAmir Goldstein ovl_set_flag(OVL_WHITEOUTS, inode); 588b79e05aaSAmir Goldstein 589e9be9d5eSMiklos Szeredi out: 590b148cba4SMiklos Szeredi if (err && !c->tmpfile) 591b148cba4SMiklos Szeredi ovl_cleanup(d_inode(c->workdir), temp); 592e85f82ffSMiklos Szeredi dput(temp); 593e9be9d5eSMiklos Szeredi return err; 594e9be9d5eSMiklos Szeredi 595e9be9d5eSMiklos Szeredi } 596e9be9d5eSMiklos Szeredi 597e9be9d5eSMiklos Szeredi /* 598e9be9d5eSMiklos Szeredi * Copy up a single dentry 599e9be9d5eSMiklos Szeredi * 600a6c60655SMiklos Szeredi * All renames start with copy up of source if necessary. The actual 601a6c60655SMiklos Szeredi * rename will only proceed once the copy up was successful. Copy up uses 602a6c60655SMiklos Szeredi * upper parent i_mutex for exclusion. Since rename can change d_parent it 603a6c60655SMiklos Szeredi * is possible that the copy up will lock the old parent. At that point 604a6c60655SMiklos Szeredi * the file will have already been copied up anyway. 605e9be9d5eSMiklos Szeredi */ 606a6fb235aSMiklos Szeredi static int ovl_do_copy_up(struct ovl_copy_up_ctx *c) 607e9be9d5eSMiklos Szeredi { 608e9be9d5eSMiklos Szeredi int err; 60923f0ab13SMiklos Szeredi struct ovl_fs *ofs = c->dentry->d_sb->s_fs_info; 610016b720fSAmir Goldstein bool to_index = false; 61159be0971SAmir Goldstein 612016b720fSAmir Goldstein /* 613016b720fSAmir Goldstein * Indexed non-dir is copied up directly to the index entry and then 614016b720fSAmir Goldstein * hardlinked to upper dir. Indexed dir is copied up to indexdir, 615016b720fSAmir Goldstein * then index entry is created and then copied up dir installed. 616016b720fSAmir Goldstein * Copying dir up to indexdir instead of workdir simplifies locking. 617016b720fSAmir Goldstein */ 618016b720fSAmir Goldstein if (ovl_need_index(c->dentry)) { 619016b720fSAmir Goldstein c->indexed = true; 620016b720fSAmir Goldstein if (S_ISDIR(c->stat.mode)) 621016b720fSAmir Goldstein c->workdir = ovl_indexdir(c->dentry->d_sb); 622016b720fSAmir Goldstein else 623016b720fSAmir Goldstein to_index = true; 624016b720fSAmir Goldstein } 625016b720fSAmir Goldstein 626016b720fSAmir Goldstein if (S_ISDIR(c->stat.mode) || c->stat.nlink == 1 || to_index) 62759be0971SAmir Goldstein c->origin = true; 62859be0971SAmir Goldstein 629016b720fSAmir Goldstein if (to_index) { 63059be0971SAmir Goldstein c->destdir = ovl_indexdir(c->dentry->d_sb); 63159be0971SAmir Goldstein err = ovl_get_index_name(c->lowerpath.dentry, &c->destname); 632f3a15685SAmir Goldstein if (err) 633f3a15685SAmir Goldstein return err; 634aa3ff3c1SAmir Goldstein } else if (WARN_ON(!c->parent)) { 635aa3ff3c1SAmir Goldstein /* Disconnected dentry must be copied up to index dir */ 636aa3ff3c1SAmir Goldstein return -EIO; 63759be0971SAmir Goldstein } else { 63859be0971SAmir Goldstein /* 63959be0971SAmir Goldstein * Mark parent "impure" because it may now contain non-pure 64059be0971SAmir Goldstein * upper 64159be0971SAmir Goldstein */ 64259be0971SAmir Goldstein err = ovl_set_impure(c->parent, c->destdir); 64359be0971SAmir Goldstein if (err) 64459be0971SAmir Goldstein return err; 64559be0971SAmir Goldstein } 646f3a15685SAmir Goldstein 64701ad3eb8SAmir Goldstein /* Should we copyup with O_TMPFILE or with workdir? */ 64823f0ab13SMiklos Szeredi if (S_ISREG(c->stat.mode) && ofs->tmpfile) { 64923f0ab13SMiklos Szeredi c->tmpfile = true; 65059be0971SAmir Goldstein err = ovl_copy_up_locked(c); 65159be0971SAmir Goldstein } else { 6525820dc08SAmir Goldstein err = ovl_lock_rename_workdir(c->workdir, c->destdir); 6535820dc08SAmir Goldstein if (!err) { 65423f0ab13SMiklos Szeredi err = ovl_copy_up_locked(c); 65559be0971SAmir Goldstein unlock_rename(c->workdir, c->destdir); 65659be0971SAmir Goldstein } 65759be0971SAmir Goldstein } 65859be0971SAmir Goldstein 659aa3ff3c1SAmir Goldstein 660aa3ff3c1SAmir Goldstein if (err) 661aa3ff3c1SAmir Goldstein goto out; 662aa3ff3c1SAmir Goldstein 663aa3ff3c1SAmir Goldstein if (c->indexed) 66459be0971SAmir Goldstein ovl_set_flag(OVL_INDEX, d_inode(c->dentry)); 665016b720fSAmir Goldstein 666016b720fSAmir Goldstein if (to_index) { 667aa3ff3c1SAmir Goldstein /* Initialize nlink for copy up of disconnected dentry */ 668aa3ff3c1SAmir Goldstein err = ovl_set_nlink_upper(c->dentry); 669aa3ff3c1SAmir Goldstein } else { 67059be0971SAmir Goldstein struct inode *udir = d_inode(c->destdir); 67159be0971SAmir Goldstein 67259be0971SAmir Goldstein /* Restore timestamps on parent (best effort) */ 67359be0971SAmir Goldstein inode_lock(udir); 67459be0971SAmir Goldstein ovl_set_timestamps(c->destdir, &c->pstat); 67559be0971SAmir Goldstein inode_unlock(udir); 67659be0971SAmir Goldstein 67759be0971SAmir Goldstein ovl_dentry_set_upper_alias(c->dentry); 678fd210b7dSMiklos Szeredi } 679a6fb235aSMiklos Szeredi 680aa3ff3c1SAmir Goldstein out: 681aa3ff3c1SAmir Goldstein if (to_index) 682aa3ff3c1SAmir Goldstein kfree(c->destname.name); 683a6fb235aSMiklos Szeredi return err; 684a6fb235aSMiklos Szeredi } 685a6fb235aSMiklos Szeredi 68644d5bf10SVivek Goyal static bool ovl_need_meta_copy_up(struct dentry *dentry, umode_t mode, 68744d5bf10SVivek Goyal int flags) 68844d5bf10SVivek Goyal { 68944d5bf10SVivek Goyal struct ovl_fs *ofs = dentry->d_sb->s_fs_info; 69044d5bf10SVivek Goyal 69144d5bf10SVivek Goyal /* TODO: Will enable metacopy in last patch of series */ 69244d5bf10SVivek Goyal return false; 69344d5bf10SVivek Goyal 69444d5bf10SVivek Goyal if (!ofs->config.metacopy) 69544d5bf10SVivek Goyal return false; 69644d5bf10SVivek Goyal 69744d5bf10SVivek Goyal if (!S_ISREG(mode)) 69844d5bf10SVivek Goyal return false; 69944d5bf10SVivek Goyal 70044d5bf10SVivek Goyal if (flags && ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC))) 70144d5bf10SVivek Goyal return false; 70244d5bf10SVivek Goyal 70344d5bf10SVivek Goyal return true; 70444d5bf10SVivek Goyal } 70544d5bf10SVivek Goyal 7060c288874SVivek Goyal /* Copy up data of an inode which was copied up metadata only in the past. */ 7070c288874SVivek Goyal static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c) 7080c288874SVivek Goyal { 7090c288874SVivek Goyal struct path upperpath; 7100c288874SVivek Goyal int err; 7110c288874SVivek Goyal 7120c288874SVivek Goyal ovl_path_upper(c->dentry, &upperpath); 7130c288874SVivek Goyal if (WARN_ON(upperpath.dentry == NULL)) 7140c288874SVivek Goyal return -EIO; 7150c288874SVivek Goyal 7160c288874SVivek Goyal err = ovl_copy_up_data(&c->lowerpath, &upperpath, c->stat.size); 7170c288874SVivek Goyal if (err) 7180c288874SVivek Goyal return err; 7190c288874SVivek Goyal 7200c288874SVivek Goyal err = vfs_removexattr(upperpath.dentry, OVL_XATTR_METACOPY); 7210c288874SVivek Goyal if (err) 7220c288874SVivek Goyal return err; 7230c288874SVivek Goyal 7240c288874SVivek Goyal ovl_set_upperdata(d_inode(c->dentry)); 7250c288874SVivek Goyal return err; 7260c288874SVivek Goyal } 7270c288874SVivek Goyal 728a6fb235aSMiklos Szeredi static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, 729a6fb235aSMiklos Szeredi int flags) 730a6fb235aSMiklos Szeredi { 731a6fb235aSMiklos Szeredi int err; 732a6fb235aSMiklos Szeredi DEFINE_DELAYED_CALL(done); 733a6fb235aSMiklos Szeredi struct path parentpath; 734a6fb235aSMiklos Szeredi struct ovl_copy_up_ctx ctx = { 735a6fb235aSMiklos Szeredi .parent = parent, 736a6fb235aSMiklos Szeredi .dentry = dentry, 737a6fb235aSMiklos Szeredi .workdir = ovl_workdir(dentry), 738a6fb235aSMiklos Szeredi }; 739a6fb235aSMiklos Szeredi 740a6fb235aSMiklos Szeredi if (WARN_ON(!ctx.workdir)) 741a6fb235aSMiklos Szeredi return -EROFS; 742a6fb235aSMiklos Szeredi 743a6fb235aSMiklos Szeredi ovl_path_lower(dentry, &ctx.lowerpath); 744a6fb235aSMiklos Szeredi err = vfs_getattr(&ctx.lowerpath, &ctx.stat, 745a6fb235aSMiklos Szeredi STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT); 746a6fb235aSMiklos Szeredi if (err) 747a6fb235aSMiklos Szeredi return err; 748a6fb235aSMiklos Szeredi 74944d5bf10SVivek Goyal ctx.metacopy = ovl_need_meta_copy_up(dentry, ctx.stat.mode, flags); 75044d5bf10SVivek Goyal 751aa3ff3c1SAmir Goldstein if (parent) { 752a6fb235aSMiklos Szeredi ovl_path_upper(parent, &parentpath); 75359be0971SAmir Goldstein ctx.destdir = parentpath.dentry; 75459be0971SAmir Goldstein ctx.destname = dentry->d_name; 755a6fb235aSMiklos Szeredi 756a6fb235aSMiklos Szeredi err = vfs_getattr(&parentpath, &ctx.pstat, 757aa3ff3c1SAmir Goldstein STATX_ATIME | STATX_MTIME, 758aa3ff3c1SAmir Goldstein AT_STATX_SYNC_AS_STAT); 759a6fb235aSMiklos Szeredi if (err) 760a6fb235aSMiklos Szeredi return err; 761aa3ff3c1SAmir Goldstein } 762a6fb235aSMiklos Szeredi 763a6fb235aSMiklos Szeredi /* maybe truncate regular file. this has no effect on dirs */ 764a6fb235aSMiklos Szeredi if (flags & O_TRUNC) 765a6fb235aSMiklos Szeredi ctx.stat.size = 0; 766a6fb235aSMiklos Szeredi 767a6fb235aSMiklos Szeredi if (S_ISLNK(ctx.stat.mode)) { 768a6fb235aSMiklos Szeredi ctx.link = vfs_get_link(ctx.lowerpath.dentry, &done); 769a6fb235aSMiklos Szeredi if (IS_ERR(ctx.link)) 770a6fb235aSMiklos Szeredi return PTR_ERR(ctx.link); 771a6fb235aSMiklos Szeredi } 772a6fb235aSMiklos Szeredi 7730c288874SVivek Goyal err = ovl_copy_up_start(dentry, flags); 774fd210b7dSMiklos Szeredi /* err < 0: interrupted, err > 0: raced with another copy-up */ 775fd210b7dSMiklos Szeredi if (unlikely(err)) { 776fd210b7dSMiklos Szeredi if (err > 0) 777fd210b7dSMiklos Szeredi err = 0; 778fd210b7dSMiklos Szeredi } else { 77959be0971SAmir Goldstein if (!ovl_dentry_upper(dentry)) 780a6fb235aSMiklos Szeredi err = ovl_do_copy_up(&ctx); 781aa3ff3c1SAmir Goldstein if (!err && parent && !ovl_dentry_has_upper_alias(dentry)) 782f4439de1SAmir Goldstein err = ovl_link_up(&ctx); 7830c288874SVivek Goyal if (!err && ovl_dentry_needs_data_copy_up_locked(dentry, flags)) 7840c288874SVivek Goyal err = ovl_copy_up_meta_inode_data(&ctx); 785fd210b7dSMiklos Szeredi ovl_copy_up_end(dentry); 786fd210b7dSMiklos Szeredi } 7877764235bSMiklos Szeredi do_delayed_call(&done); 788e9be9d5eSMiklos Szeredi 789e9be9d5eSMiklos Szeredi return err; 790e9be9d5eSMiklos Szeredi } 791e9be9d5eSMiklos Szeredi 7929aba6521SAmir Goldstein int ovl_copy_up_flags(struct dentry *dentry, int flags) 793e9be9d5eSMiklos Szeredi { 7948eac98b8SVivek Goyal int err = 0; 7958eac98b8SVivek Goyal const struct cred *old_cred = ovl_override_creds(dentry->d_sb); 796aa3ff3c1SAmir Goldstein bool disconnected = (dentry->d_flags & DCACHE_DISCONNECTED); 797aa3ff3c1SAmir Goldstein 798aa3ff3c1SAmir Goldstein /* 799aa3ff3c1SAmir Goldstein * With NFS export, copy up can get called for a disconnected non-dir. 800aa3ff3c1SAmir Goldstein * In this case, we will copy up lower inode to index dir without 801aa3ff3c1SAmir Goldstein * linking it to upper dir. 802aa3ff3c1SAmir Goldstein */ 803aa3ff3c1SAmir Goldstein if (WARN_ON(disconnected && d_is_dir(dentry))) 804aa3ff3c1SAmir Goldstein return -EIO; 805e9be9d5eSMiklos Szeredi 806e9be9d5eSMiklos Szeredi while (!err) { 807e9be9d5eSMiklos Szeredi struct dentry *next; 808aa3ff3c1SAmir Goldstein struct dentry *parent = NULL; 809e9be9d5eSMiklos Szeredi 8100c288874SVivek Goyal if (ovl_already_copied_up(dentry, flags)) 811e9be9d5eSMiklos Szeredi break; 812e9be9d5eSMiklos Szeredi 813e9be9d5eSMiklos Szeredi next = dget(dentry); 814e9be9d5eSMiklos Szeredi /* find the topmost dentry not yet copied up */ 815aa3ff3c1SAmir Goldstein for (; !disconnected;) { 816e9be9d5eSMiklos Szeredi parent = dget_parent(next); 817e9be9d5eSMiklos Szeredi 81859be0971SAmir Goldstein if (ovl_dentry_upper(parent)) 819e9be9d5eSMiklos Szeredi break; 820e9be9d5eSMiklos Szeredi 821e9be9d5eSMiklos Szeredi dput(next); 822e9be9d5eSMiklos Szeredi next = parent; 823e9be9d5eSMiklos Szeredi } 824e9be9d5eSMiklos Szeredi 825a6fb235aSMiklos Szeredi err = ovl_copy_up_one(parent, next, flags); 826e9be9d5eSMiklos Szeredi 827e9be9d5eSMiklos Szeredi dput(parent); 828e9be9d5eSMiklos Szeredi dput(next); 829e9be9d5eSMiklos Szeredi } 8308eac98b8SVivek Goyal revert_creds(old_cred); 831e9be9d5eSMiklos Szeredi 832e9be9d5eSMiklos Szeredi return err; 833e9be9d5eSMiklos Szeredi } 8349aba6521SAmir Goldstein 835d6eac039SVivek Goyal static bool ovl_open_need_copy_up(struct dentry *dentry, int flags) 836d6eac039SVivek Goyal { 837d6eac039SVivek Goyal /* Copy up of disconnected dentry does not set upper alias */ 8380c288874SVivek Goyal if (ovl_already_copied_up(dentry, flags)) 839d6eac039SVivek Goyal return false; 840d6eac039SVivek Goyal 841d6eac039SVivek Goyal if (special_file(d_inode(dentry)->i_mode)) 842d6eac039SVivek Goyal return false; 843d6eac039SVivek Goyal 8440c288874SVivek Goyal if (!ovl_open_flags_need_copy_up(flags)) 845d6eac039SVivek Goyal return false; 846d6eac039SVivek Goyal 847d6eac039SVivek Goyal return true; 848d6eac039SVivek Goyal } 849d6eac039SVivek Goyal 850d6eac039SVivek Goyal int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags) 851d6eac039SVivek Goyal { 852d6eac039SVivek Goyal int err = 0; 853d6eac039SVivek Goyal 854d6eac039SVivek Goyal if (ovl_open_need_copy_up(dentry, file_flags)) { 855d6eac039SVivek Goyal err = ovl_want_write(dentry); 856d6eac039SVivek Goyal if (!err) { 857d6eac039SVivek Goyal err = ovl_copy_up_flags(dentry, file_flags); 858d6eac039SVivek Goyal ovl_drop_write(dentry); 859d6eac039SVivek Goyal } 860d6eac039SVivek Goyal } 861d6eac039SVivek Goyal 862d6eac039SVivek Goyal return err; 863d6eac039SVivek Goyal } 864d6eac039SVivek Goyal 8659aba6521SAmir Goldstein int ovl_copy_up(struct dentry *dentry) 8669aba6521SAmir Goldstein { 8679aba6521SAmir Goldstein return ovl_copy_up_flags(dentry, 0); 8689aba6521SAmir Goldstein } 869