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*param) 26fb5bb2c3SDavid Howells { 27670c2324SMiklos Szeredi pr_warn("overlayfs: \"check_copy_up\" module option is obsolete\n"); 28fb5bb2c3SDavid Howells return 0; 29fb5bb2c3SDavid Howells } 30fb5bb2c3SDavid Howells 31670c2324SMiklos Szeredi static int ovl_ccup_get(char *buf, const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); 37253e7483SNicolas Schier MODULE_PARM_DESC(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 254cbe7fba8SAmir Goldstein /* Make sure the real fid stays 32bit aligned */ 255cbe7fba8SAmir Goldstein BUILD_BUG_ON(OVL_FH_FID_OFFSET % 4); 256cbe7fba8SAmir Goldstein BUILD_BUG_ON(MAX_HANDLE_SZ + OVL_FH_FID_OFFSET > 255); 257cbe7fba8SAmir Goldstein fh_len = OVL_FH_FID_OFFSET + buflen; 258cbe7fba8SAmir Goldstein fh = kzalloc(fh_len, GFP_KERNEL); 2593a1e819bSAmir Goldstein if (!fh) { 2603a1e819bSAmir Goldstein fh = ERR_PTR(-ENOMEM); 2613a1e819bSAmir Goldstein goto out; 2623a1e819bSAmir Goldstein } 2633a1e819bSAmir Goldstein 264cbe7fba8SAmir Goldstein fh->fb.version = OVL_FH_VERSION; 265cbe7fba8SAmir Goldstein fh->fb.magic = OVL_FH_MAGIC; 266cbe7fba8SAmir Goldstein fh->fb.type = fh_type; 267cbe7fba8SAmir Goldstein fh->fb.flags = OVL_FH_FLAG_CPU_ENDIAN; 26854fb347eSAmir Goldstein /* 26954fb347eSAmir Goldstein * When we will want to decode an overlay dentry from this handle 27054fb347eSAmir Goldstein * and all layers are on the same fs, if we get a disconncted real 27154fb347eSAmir Goldstein * dentry when we decode fid, the only way to tell if we should assign 27254fb347eSAmir Goldstein * it to upperdentry or to lowerstack is by checking this flag. 27354fb347eSAmir Goldstein */ 27454fb347eSAmir Goldstein if (is_upper) 275cbe7fba8SAmir Goldstein fh->fb.flags |= OVL_FH_FLAG_PATH_UPPER; 276cbe7fba8SAmir Goldstein fh->fb.len = fh_len - OVL_FH_WIRE_OFFSET; 277cbe7fba8SAmir Goldstein fh->fb.uuid = *uuid; 278cbe7fba8SAmir Goldstein memcpy(fh->fb.fid, buf, buflen); 2793a1e819bSAmir Goldstein 2803a1e819bSAmir Goldstein out: 2813a1e819bSAmir Goldstein kfree(buf); 2823a1e819bSAmir Goldstein return fh; 2833a1e819bSAmir Goldstein } 2843a1e819bSAmir Goldstein 2859678e630SAmir Goldstein int ovl_set_origin(struct dentry *dentry, struct dentry *lower, 2863a1e819bSAmir Goldstein struct dentry *upper) 2873a1e819bSAmir Goldstein { 2883a1e819bSAmir Goldstein const struct ovl_fh *fh = NULL; 2893a1e819bSAmir Goldstein int err; 2903a1e819bSAmir Goldstein 2913a1e819bSAmir Goldstein /* 2923a1e819bSAmir Goldstein * When lower layer doesn't support export operations store a 'null' fh, 2933a1e819bSAmir Goldstein * so we can use the overlay.origin xattr to distignuish between a copy 2943a1e819bSAmir Goldstein * up and a pure upper inode. 2953a1e819bSAmir Goldstein */ 29602bcd157SAmir Goldstein if (ovl_can_decode_fh(lower->d_sb)) { 2975b2cccd3SAmir Goldstein fh = ovl_encode_real_fh(lower, false); 2983a1e819bSAmir Goldstein if (IS_ERR(fh)) 2993a1e819bSAmir Goldstein return PTR_ERR(fh); 3003a1e819bSAmir Goldstein } 3013a1e819bSAmir Goldstein 3026266d465SMiklos Szeredi /* 3036266d465SMiklos Szeredi * Do not fail when upper doesn't support xattrs. 3046266d465SMiklos Szeredi */ 305cbe7fba8SAmir Goldstein err = ovl_check_setxattr(dentry, upper, OVL_XATTR_ORIGIN, fh->buf, 306cbe7fba8SAmir Goldstein fh ? fh->fb.len : 0, 0); 3073a1e819bSAmir Goldstein kfree(fh); 3083a1e819bSAmir Goldstein 3093a1e819bSAmir Goldstein return err; 3103a1e819bSAmir Goldstein } 3113a1e819bSAmir Goldstein 312016b720fSAmir Goldstein /* Store file handle of @upper dir in @index dir entry */ 313016b720fSAmir Goldstein static int ovl_set_upper_fh(struct dentry *upper, struct dentry *index) 314016b720fSAmir Goldstein { 315016b720fSAmir Goldstein const struct ovl_fh *fh; 316016b720fSAmir Goldstein int err; 317016b720fSAmir Goldstein 3185b2cccd3SAmir Goldstein fh = ovl_encode_real_fh(upper, true); 319016b720fSAmir Goldstein if (IS_ERR(fh)) 320016b720fSAmir Goldstein return PTR_ERR(fh); 321016b720fSAmir Goldstein 322cbe7fba8SAmir Goldstein err = ovl_do_setxattr(index, OVL_XATTR_UPPER, fh->buf, fh->fb.len, 0); 323016b720fSAmir Goldstein 324016b720fSAmir Goldstein kfree(fh); 325016b720fSAmir Goldstein return err; 326016b720fSAmir Goldstein } 327016b720fSAmir Goldstein 328016b720fSAmir Goldstein /* 329016b720fSAmir Goldstein * Create and install index entry. 330016b720fSAmir Goldstein * 331016b720fSAmir Goldstein * Caller must hold i_mutex on indexdir. 332016b720fSAmir Goldstein */ 333016b720fSAmir Goldstein static int ovl_create_index(struct dentry *dentry, struct dentry *origin, 334016b720fSAmir Goldstein struct dentry *upper) 335016b720fSAmir Goldstein { 336016b720fSAmir Goldstein struct dentry *indexdir = ovl_indexdir(dentry->d_sb); 337016b720fSAmir Goldstein struct inode *dir = d_inode(indexdir); 338016b720fSAmir Goldstein struct dentry *index = NULL; 339016b720fSAmir Goldstein struct dentry *temp = NULL; 340016b720fSAmir Goldstein struct qstr name = { }; 341016b720fSAmir Goldstein int err; 342016b720fSAmir Goldstein 343016b720fSAmir Goldstein /* 344016b720fSAmir Goldstein * For now this is only used for creating index entry for directories, 345016b720fSAmir Goldstein * because non-dir are copied up directly to index and then hardlinked 346016b720fSAmir Goldstein * to upper dir. 347016b720fSAmir Goldstein * 348016b720fSAmir Goldstein * TODO: implement create index for non-dir, so we can call it when 349016b720fSAmir Goldstein * encoding file handle for non-dir in case index does not exist. 350016b720fSAmir Goldstein */ 351016b720fSAmir Goldstein if (WARN_ON(!d_is_dir(dentry))) 352016b720fSAmir Goldstein return -EIO; 353016b720fSAmir Goldstein 354016b720fSAmir Goldstein /* Directory not expected to be indexed before copy up */ 355016b720fSAmir Goldstein if (WARN_ON(ovl_test_flag(OVL_INDEX, d_inode(dentry)))) 356016b720fSAmir Goldstein return -EIO; 357016b720fSAmir Goldstein 358016b720fSAmir Goldstein err = ovl_get_index_name(origin, &name); 359016b720fSAmir Goldstein if (err) 360016b720fSAmir Goldstein return err; 361016b720fSAmir Goldstein 362137ec526SAmir Goldstein temp = ovl_create_temp(indexdir, OVL_CATTR(S_IFDIR | 0)); 363b148cba4SMiklos Szeredi err = PTR_ERR(temp); 364016b720fSAmir Goldstein if (IS_ERR(temp)) 365b148cba4SMiklos Szeredi goto free_name; 366016b720fSAmir Goldstein 367016b720fSAmir Goldstein err = ovl_set_upper_fh(upper, temp); 368016b720fSAmir Goldstein if (err) 369b148cba4SMiklos Szeredi goto out; 370016b720fSAmir Goldstein 371016b720fSAmir Goldstein index = lookup_one_len(name.name, indexdir, name.len); 372016b720fSAmir Goldstein if (IS_ERR(index)) { 373016b720fSAmir Goldstein err = PTR_ERR(index); 374016b720fSAmir Goldstein } else { 375016b720fSAmir Goldstein err = ovl_do_rename(dir, temp, dir, index, 0); 376016b720fSAmir Goldstein dput(index); 377016b720fSAmir Goldstein } 378016b720fSAmir Goldstein out: 379b148cba4SMiklos Szeredi if (err) 380b148cba4SMiklos Szeredi ovl_cleanup(dir, temp); 381016b720fSAmir Goldstein dput(temp); 382b148cba4SMiklos Szeredi free_name: 383016b720fSAmir Goldstein kfree(name.name); 384016b720fSAmir Goldstein return err; 385016b720fSAmir Goldstein } 386016b720fSAmir Goldstein 38723f0ab13SMiklos Szeredi struct ovl_copy_up_ctx { 388a6fb235aSMiklos Szeredi struct dentry *parent; 38923f0ab13SMiklos Szeredi struct dentry *dentry; 39023f0ab13SMiklos Szeredi struct path lowerpath; 39123f0ab13SMiklos Szeredi struct kstat stat; 39223f0ab13SMiklos Szeredi struct kstat pstat; 39323f0ab13SMiklos Szeredi const char *link; 39459be0971SAmir Goldstein struct dentry *destdir; 39559be0971SAmir Goldstein struct qstr destname; 39623f0ab13SMiklos Szeredi struct dentry *workdir; 39759be0971SAmir Goldstein bool origin; 398016b720fSAmir Goldstein bool indexed; 39944d5bf10SVivek Goyal bool metacopy; 40023f0ab13SMiklos Szeredi }; 40123f0ab13SMiklos Szeredi 402f4439de1SAmir Goldstein static int ovl_link_up(struct ovl_copy_up_ctx *c) 403f4439de1SAmir Goldstein { 404f4439de1SAmir Goldstein int err; 405f4439de1SAmir Goldstein struct dentry *upper; 406f4439de1SAmir Goldstein struct dentry *upperdir = ovl_dentry_upper(c->parent); 407f4439de1SAmir Goldstein struct inode *udir = d_inode(upperdir); 408f4439de1SAmir Goldstein 409f4439de1SAmir Goldstein /* Mark parent "impure" because it may now contain non-pure upper */ 410f4439de1SAmir Goldstein err = ovl_set_impure(c->parent, upperdir); 411f4439de1SAmir Goldstein if (err) 412f4439de1SAmir Goldstein return err; 413f4439de1SAmir Goldstein 414f4439de1SAmir Goldstein err = ovl_set_nlink_lower(c->dentry); 415f4439de1SAmir Goldstein if (err) 416f4439de1SAmir Goldstein return err; 417f4439de1SAmir Goldstein 418f4439de1SAmir Goldstein inode_lock_nested(udir, I_MUTEX_PARENT); 419f4439de1SAmir Goldstein upper = lookup_one_len(c->dentry->d_name.name, upperdir, 420f4439de1SAmir Goldstein c->dentry->d_name.len); 421f4439de1SAmir Goldstein err = PTR_ERR(upper); 422f4439de1SAmir Goldstein if (!IS_ERR(upper)) { 4236cf00764SAmir Goldstein err = ovl_do_link(ovl_dentry_upper(c->dentry), udir, upper); 424f4439de1SAmir Goldstein dput(upper); 425f4439de1SAmir Goldstein 426f4439de1SAmir Goldstein if (!err) { 427f4439de1SAmir Goldstein /* Restore timestamps on parent (best effort) */ 428f4439de1SAmir Goldstein ovl_set_timestamps(upperdir, &c->pstat); 429f4439de1SAmir Goldstein ovl_dentry_set_upper_alias(c->dentry); 430f4439de1SAmir Goldstein } 431f4439de1SAmir Goldstein } 432f4439de1SAmir Goldstein inode_unlock(udir); 433aa3ff3c1SAmir Goldstein if (err) 434aa3ff3c1SAmir Goldstein return err; 435aa3ff3c1SAmir Goldstein 436aa3ff3c1SAmir Goldstein err = ovl_set_nlink_upper(c->dentry); 437f4439de1SAmir Goldstein 438f4439de1SAmir Goldstein return err; 439f4439de1SAmir Goldstein } 440f4439de1SAmir Goldstein 44123f0ab13SMiklos Szeredi static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp) 44202209d10SAmir Goldstein { 44302209d10SAmir Goldstein int err; 44402209d10SAmir Goldstein 4455f32879eSVivek Goyal /* 4465f32879eSVivek Goyal * Copy up data first and then xattrs. Writing data after 4475f32879eSVivek Goyal * xattrs will remove security.capability xattr automatically. 4485f32879eSVivek Goyal */ 4495f32879eSVivek Goyal if (S_ISREG(c->stat.mode) && !c->metacopy) { 4505f32879eSVivek Goyal struct path upperpath, datapath; 4515f32879eSVivek Goyal 4525f32879eSVivek Goyal ovl_path_upper(c->dentry, &upperpath); 4535f32879eSVivek Goyal if (WARN_ON(upperpath.dentry != NULL)) 4545f32879eSVivek Goyal return -EIO; 4555f32879eSVivek Goyal upperpath.dentry = temp; 4565f32879eSVivek Goyal 4575f32879eSVivek Goyal ovl_path_lowerdata(c->dentry, &datapath); 4585f32879eSVivek Goyal err = ovl_copy_up_data(&datapath, &upperpath, c->stat.size); 4595f32879eSVivek Goyal if (err) 4605f32879eSVivek Goyal return err; 4615f32879eSVivek Goyal } 4625f32879eSVivek Goyal 46323f0ab13SMiklos Szeredi err = ovl_copy_xattr(c->lowerpath.dentry, temp); 46402209d10SAmir Goldstein if (err) 46502209d10SAmir Goldstein return err; 46602209d10SAmir Goldstein 46702209d10SAmir Goldstein /* 46802209d10SAmir Goldstein * Store identifier of lower inode in upper inode xattr to 46902209d10SAmir Goldstein * allow lookup of the copy up origin inode. 47002209d10SAmir Goldstein * 47102209d10SAmir Goldstein * Don't set origin when we are breaking the association with a lower 47202209d10SAmir Goldstein * hard link. 47302209d10SAmir Goldstein */ 47459be0971SAmir Goldstein if (c->origin) { 47523f0ab13SMiklos Szeredi err = ovl_set_origin(c->dentry, c->lowerpath.dentry, temp); 47602209d10SAmir Goldstein if (err) 47702209d10SAmir Goldstein return err; 47802209d10SAmir Goldstein } 47902209d10SAmir Goldstein 4800c288874SVivek Goyal if (c->metacopy) { 4810c288874SVivek Goyal err = ovl_check_setxattr(c->dentry, temp, OVL_XATTR_METACOPY, 4820c288874SVivek Goyal NULL, 0, -EOPNOTSUPP); 4830c288874SVivek Goyal if (err) 4840c288874SVivek Goyal return err; 4850c288874SVivek Goyal } 4860c288874SVivek Goyal 487bd64e575SVivek Goyal inode_lock(temp->d_inode); 4880c288874SVivek Goyal if (c->metacopy) 4890c288874SVivek Goyal err = ovl_set_size(temp, &c->stat); 4900c288874SVivek Goyal if (!err) 491bd64e575SVivek Goyal err = ovl_set_attr(temp, &c->stat); 492bd64e575SVivek Goyal inode_unlock(temp->d_inode); 493bd64e575SVivek Goyal 494bd64e575SVivek Goyal return err; 49502209d10SAmir Goldstein } 49602209d10SAmir Goldstein 4976b52243fSMiklos Szeredi struct ovl_cu_creds { 4986b52243fSMiklos Szeredi const struct cred *old; 4996b52243fSMiklos Szeredi struct cred *new; 500b10cdcdcSAmir Goldstein }; 501b10cdcdcSAmir Goldstein 5026b52243fSMiklos Szeredi static int ovl_prep_cu_creds(struct dentry *dentry, struct ovl_cu_creds *cc) 503b10cdcdcSAmir Goldstein { 504b10cdcdcSAmir Goldstein int err; 505b10cdcdcSAmir Goldstein 5066b52243fSMiklos Szeredi cc->old = cc->new = NULL; 5076b52243fSMiklos Szeredi err = security_inode_copy_up(dentry, &cc->new); 5086b52243fSMiklos Szeredi if (err < 0) 509b10cdcdcSAmir Goldstein return err; 5106b52243fSMiklos Szeredi 5116b52243fSMiklos Szeredi if (cc->new) 5126b52243fSMiklos Szeredi cc->old = override_creds(cc->new); 5136b52243fSMiklos Szeredi 5146b52243fSMiklos Szeredi return 0; 5156b52243fSMiklos Szeredi } 5166b52243fSMiklos Szeredi 5176b52243fSMiklos Szeredi static void ovl_revert_cu_creds(struct ovl_cu_creds *cc) 5186b52243fSMiklos Szeredi { 5196b52243fSMiklos Szeredi if (cc->new) { 5206b52243fSMiklos Szeredi revert_creds(cc->old); 5216b52243fSMiklos Szeredi put_cred(cc->new); 5226b52243fSMiklos Szeredi } 523b10cdcdcSAmir Goldstein } 524b10cdcdcSAmir Goldstein 525b10cdcdcSAmir Goldstein /* 526b10cdcdcSAmir Goldstein * Copyup using workdir to prepare temp file. Used when copying up directories, 527b10cdcdcSAmir Goldstein * special files or when upper fs doesn't support O_TMPFILE. 528b10cdcdcSAmir Goldstein */ 529b10cdcdcSAmir Goldstein static int ovl_copy_up_workdir(struct ovl_copy_up_ctx *c) 530b10cdcdcSAmir Goldstein { 531b79e05aaSAmir Goldstein struct inode *inode; 5326b52243fSMiklos Szeredi struct inode *udir = d_inode(c->destdir), *wdir = d_inode(c->workdir); 5336b52243fSMiklos Szeredi struct dentry *temp, *upper; 5346b52243fSMiklos Szeredi struct ovl_cu_creds cc; 5357d90b853SMiklos Szeredi int err; 5366b52243fSMiklos Szeredi struct ovl_cattr cattr = { 5376b52243fSMiklos Szeredi /* Can't properly set mode on creation because of the umask */ 5386b52243fSMiklos Szeredi .mode = c->stat.mode & S_IFMT, 5396b52243fSMiklos Szeredi .rdev = c->stat.rdev, 5406b52243fSMiklos Szeredi .link = c->link 5416b52243fSMiklos Szeredi }; 5427d90b853SMiklos Szeredi 543b10cdcdcSAmir Goldstein err = ovl_lock_rename_workdir(c->workdir, c->destdir); 544b10cdcdcSAmir Goldstein if (err) 545b10cdcdcSAmir Goldstein return err; 546b10cdcdcSAmir Goldstein 5476b52243fSMiklos Szeredi err = ovl_prep_cu_creds(c->dentry, &cc); 5486b52243fSMiklos Szeredi if (err) 5496b52243fSMiklos Szeredi goto unlock; 5506b52243fSMiklos Szeredi 5516b52243fSMiklos Szeredi temp = ovl_create_temp(c->workdir, &cattr); 5526b52243fSMiklos Szeredi ovl_revert_cu_creds(&cc); 5536b52243fSMiklos Szeredi 554b10cdcdcSAmir Goldstein err = PTR_ERR(temp); 555b10cdcdcSAmir Goldstein if (IS_ERR(temp)) 556b10cdcdcSAmir Goldstein goto unlock; 557b10cdcdcSAmir Goldstein 558b10cdcdcSAmir Goldstein err = ovl_copy_up_inode(c, temp); 559b10cdcdcSAmir Goldstein if (err) 560b10cdcdcSAmir Goldstein goto cleanup; 561b10cdcdcSAmir Goldstein 562b10cdcdcSAmir Goldstein if (S_ISDIR(c->stat.mode) && c->indexed) { 563b10cdcdcSAmir Goldstein err = ovl_create_index(c->dentry, c->lowerpath.dentry, temp); 564b10cdcdcSAmir Goldstein if (err) 565b10cdcdcSAmir Goldstein goto cleanup; 566b10cdcdcSAmir Goldstein } 567b10cdcdcSAmir Goldstein 5686b52243fSMiklos Szeredi upper = lookup_one_len(c->destname.name, c->destdir, c->destname.len); 5696b52243fSMiklos Szeredi err = PTR_ERR(upper); 5706b52243fSMiklos Szeredi if (IS_ERR(upper)) 5716b52243fSMiklos Szeredi goto cleanup; 5726b52243fSMiklos Szeredi 5736b52243fSMiklos Szeredi err = ovl_do_rename(wdir, temp, udir, upper, 0); 5746b52243fSMiklos Szeredi dput(upper); 575b10cdcdcSAmir Goldstein if (err) 576b10cdcdcSAmir Goldstein goto cleanup; 577b10cdcdcSAmir Goldstein 578b10cdcdcSAmir Goldstein if (!c->metacopy) 579b10cdcdcSAmir Goldstein ovl_set_upperdata(d_inode(c->dentry)); 580b10cdcdcSAmir Goldstein inode = d_inode(c->dentry); 5816b52243fSMiklos Szeredi ovl_inode_update(inode, temp); 582b10cdcdcSAmir Goldstein if (S_ISDIR(inode->i_mode)) 583b10cdcdcSAmir Goldstein ovl_set_flag(OVL_WHITEOUTS, inode); 584b10cdcdcSAmir Goldstein unlock: 585b10cdcdcSAmir Goldstein unlock_rename(c->workdir, c->destdir); 586b10cdcdcSAmir Goldstein 587b10cdcdcSAmir Goldstein return err; 588b10cdcdcSAmir Goldstein 589b10cdcdcSAmir Goldstein cleanup: 5906b52243fSMiklos Szeredi ovl_cleanup(wdir, temp); 5916b52243fSMiklos Szeredi dput(temp); 592b10cdcdcSAmir Goldstein goto unlock; 593b10cdcdcSAmir Goldstein } 594b10cdcdcSAmir Goldstein 595b10cdcdcSAmir Goldstein /* Copyup using O_TMPFILE which does not require cross dir locking */ 596b10cdcdcSAmir Goldstein static int ovl_copy_up_tmpfile(struct ovl_copy_up_ctx *c) 597b10cdcdcSAmir Goldstein { 5986b52243fSMiklos Szeredi struct inode *udir = d_inode(c->destdir); 5996b52243fSMiklos Szeredi struct dentry *temp, *upper; 6006b52243fSMiklos Szeredi struct ovl_cu_creds cc; 601b10cdcdcSAmir Goldstein int err; 602b10cdcdcSAmir Goldstein 6036b52243fSMiklos Szeredi err = ovl_prep_cu_creds(c->dentry, &cc); 6046b52243fSMiklos Szeredi if (err) 6056b52243fSMiklos Szeredi return err; 6066b52243fSMiklos Szeredi 6076b52243fSMiklos Szeredi temp = ovl_do_tmpfile(c->workdir, c->stat.mode); 6086b52243fSMiklos Szeredi ovl_revert_cu_creds(&cc); 6096b52243fSMiklos Szeredi 610b148cba4SMiklos Szeredi if (IS_ERR(temp)) 611b148cba4SMiklos Szeredi return PTR_ERR(temp); 612e9be9d5eSMiklos Szeredi 61323f0ab13SMiklos Szeredi err = ovl_copy_up_inode(c, temp); 614e9be9d5eSMiklos Szeredi if (err) 6156b52243fSMiklos Szeredi goto out_dput; 6163a1e819bSAmir Goldstein 6176b52243fSMiklos Szeredi inode_lock_nested(udir, I_MUTEX_PARENT); 6186b52243fSMiklos Szeredi 6196b52243fSMiklos Szeredi upper = lookup_one_len(c->destname.name, c->destdir, c->destname.len); 6206b52243fSMiklos Szeredi err = PTR_ERR(upper); 6216b52243fSMiklos Szeredi if (!IS_ERR(upper)) { 6226b52243fSMiklos Szeredi err = ovl_do_link(temp, udir, upper); 6236b52243fSMiklos Szeredi dput(upper); 6246b52243fSMiklos Szeredi } 6256b52243fSMiklos Szeredi inode_unlock(udir); 6266b52243fSMiklos Szeredi 627e9be9d5eSMiklos Szeredi if (err) 6286b52243fSMiklos Szeredi goto out_dput; 629e9be9d5eSMiklos Szeredi 6300c288874SVivek Goyal if (!c->metacopy) 6310c288874SVivek Goyal ovl_set_upperdata(d_inode(c->dentry)); 6326b52243fSMiklos Szeredi ovl_inode_update(d_inode(c->dentry), temp); 633b79e05aaSAmir Goldstein 6346b52243fSMiklos Szeredi return 0; 6356b52243fSMiklos Szeredi 6366b52243fSMiklos Szeredi out_dput: 637e85f82ffSMiklos Szeredi dput(temp); 638e9be9d5eSMiklos Szeredi return err; 639e9be9d5eSMiklos Szeredi } 640e9be9d5eSMiklos Szeredi 641e9be9d5eSMiklos Szeredi /* 642e9be9d5eSMiklos Szeredi * Copy up a single dentry 643e9be9d5eSMiklos Szeredi * 644a6c60655SMiklos Szeredi * All renames start with copy up of source if necessary. The actual 645a6c60655SMiklos Szeredi * rename will only proceed once the copy up was successful. Copy up uses 646a6c60655SMiklos Szeredi * upper parent i_mutex for exclusion. Since rename can change d_parent it 647a6c60655SMiklos Szeredi * is possible that the copy up will lock the old parent. At that point 648a6c60655SMiklos Szeredi * the file will have already been copied up anyway. 649e9be9d5eSMiklos Szeredi */ 650a6fb235aSMiklos Szeredi static int ovl_do_copy_up(struct ovl_copy_up_ctx *c) 651e9be9d5eSMiklos Szeredi { 652e9be9d5eSMiklos Szeredi int err; 65323f0ab13SMiklos Szeredi struct ovl_fs *ofs = c->dentry->d_sb->s_fs_info; 654016b720fSAmir Goldstein bool to_index = false; 65559be0971SAmir Goldstein 656016b720fSAmir Goldstein /* 657016b720fSAmir Goldstein * Indexed non-dir is copied up directly to the index entry and then 658016b720fSAmir Goldstein * hardlinked to upper dir. Indexed dir is copied up to indexdir, 659016b720fSAmir Goldstein * then index entry is created and then copied up dir installed. 660016b720fSAmir Goldstein * Copying dir up to indexdir instead of workdir simplifies locking. 661016b720fSAmir Goldstein */ 662016b720fSAmir Goldstein if (ovl_need_index(c->dentry)) { 663016b720fSAmir Goldstein c->indexed = true; 664016b720fSAmir Goldstein if (S_ISDIR(c->stat.mode)) 665016b720fSAmir Goldstein c->workdir = ovl_indexdir(c->dentry->d_sb); 666016b720fSAmir Goldstein else 667016b720fSAmir Goldstein to_index = true; 668016b720fSAmir Goldstein } 669016b720fSAmir Goldstein 670016b720fSAmir Goldstein if (S_ISDIR(c->stat.mode) || c->stat.nlink == 1 || to_index) 67159be0971SAmir Goldstein c->origin = true; 67259be0971SAmir Goldstein 673016b720fSAmir Goldstein if (to_index) { 67459be0971SAmir Goldstein c->destdir = ovl_indexdir(c->dentry->d_sb); 67559be0971SAmir Goldstein err = ovl_get_index_name(c->lowerpath.dentry, &c->destname); 676f3a15685SAmir Goldstein if (err) 677f3a15685SAmir Goldstein return err; 678aa3ff3c1SAmir Goldstein } else if (WARN_ON(!c->parent)) { 679aa3ff3c1SAmir Goldstein /* Disconnected dentry must be copied up to index dir */ 680aa3ff3c1SAmir Goldstein return -EIO; 68159be0971SAmir Goldstein } else { 68259be0971SAmir Goldstein /* 68359be0971SAmir Goldstein * Mark parent "impure" because it may now contain non-pure 68459be0971SAmir Goldstein * upper 68559be0971SAmir Goldstein */ 68659be0971SAmir Goldstein err = ovl_set_impure(c->parent, c->destdir); 68759be0971SAmir Goldstein if (err) 68859be0971SAmir Goldstein return err; 68959be0971SAmir Goldstein } 690f3a15685SAmir Goldstein 69101ad3eb8SAmir Goldstein /* Should we copyup with O_TMPFILE or with workdir? */ 692b10cdcdcSAmir Goldstein if (S_ISREG(c->stat.mode) && ofs->tmpfile) 693b10cdcdcSAmir Goldstein err = ovl_copy_up_tmpfile(c); 694b10cdcdcSAmir Goldstein else 695b10cdcdcSAmir Goldstein err = ovl_copy_up_workdir(c); 696aa3ff3c1SAmir Goldstein if (err) 697aa3ff3c1SAmir Goldstein goto out; 698aa3ff3c1SAmir Goldstein 699aa3ff3c1SAmir Goldstein if (c->indexed) 70059be0971SAmir Goldstein ovl_set_flag(OVL_INDEX, d_inode(c->dentry)); 701016b720fSAmir Goldstein 702016b720fSAmir Goldstein if (to_index) { 703aa3ff3c1SAmir Goldstein /* Initialize nlink for copy up of disconnected dentry */ 704aa3ff3c1SAmir Goldstein err = ovl_set_nlink_upper(c->dentry); 705aa3ff3c1SAmir Goldstein } else { 70659be0971SAmir Goldstein struct inode *udir = d_inode(c->destdir); 70759be0971SAmir Goldstein 70859be0971SAmir Goldstein /* Restore timestamps on parent (best effort) */ 70959be0971SAmir Goldstein inode_lock(udir); 71059be0971SAmir Goldstein ovl_set_timestamps(c->destdir, &c->pstat); 71159be0971SAmir Goldstein inode_unlock(udir); 71259be0971SAmir Goldstein 71359be0971SAmir Goldstein ovl_dentry_set_upper_alias(c->dentry); 714fd210b7dSMiklos Szeredi } 715a6fb235aSMiklos Szeredi 716aa3ff3c1SAmir Goldstein out: 717aa3ff3c1SAmir Goldstein if (to_index) 718aa3ff3c1SAmir Goldstein kfree(c->destname.name); 719a6fb235aSMiklos Szeredi return err; 720a6fb235aSMiklos Szeredi } 721a6fb235aSMiklos Szeredi 72244d5bf10SVivek Goyal static bool ovl_need_meta_copy_up(struct dentry *dentry, umode_t mode, 72344d5bf10SVivek Goyal int flags) 72444d5bf10SVivek Goyal { 72544d5bf10SVivek Goyal struct ovl_fs *ofs = dentry->d_sb->s_fs_info; 72644d5bf10SVivek Goyal 72744d5bf10SVivek Goyal if (!ofs->config.metacopy) 72844d5bf10SVivek Goyal return false; 72944d5bf10SVivek Goyal 73044d5bf10SVivek Goyal if (!S_ISREG(mode)) 73144d5bf10SVivek Goyal return false; 73244d5bf10SVivek Goyal 73344d5bf10SVivek Goyal if (flags && ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC))) 73444d5bf10SVivek Goyal return false; 73544d5bf10SVivek Goyal 73644d5bf10SVivek Goyal return true; 73744d5bf10SVivek Goyal } 73844d5bf10SVivek Goyal 7390c288874SVivek Goyal /* Copy up data of an inode which was copied up metadata only in the past. */ 7400c288874SVivek Goyal static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c) 7410c288874SVivek Goyal { 7424f93b426SVivek Goyal struct path upperpath, datapath; 7430c288874SVivek Goyal int err; 744993a0b2aSVivek Goyal char *capability = NULL; 745993a0b2aSVivek Goyal ssize_t uninitialized_var(cap_size); 7460c288874SVivek Goyal 7470c288874SVivek Goyal ovl_path_upper(c->dentry, &upperpath); 7480c288874SVivek Goyal if (WARN_ON(upperpath.dentry == NULL)) 7490c288874SVivek Goyal return -EIO; 7500c288874SVivek Goyal 7514f93b426SVivek Goyal ovl_path_lowerdata(c->dentry, &datapath); 7524f93b426SVivek Goyal if (WARN_ON(datapath.dentry == NULL)) 7534f93b426SVivek Goyal return -EIO; 7544f93b426SVivek Goyal 755993a0b2aSVivek Goyal if (c->stat.size) { 756993a0b2aSVivek Goyal err = cap_size = ovl_getxattr(upperpath.dentry, XATTR_NAME_CAPS, 757993a0b2aSVivek Goyal &capability, 0); 758993a0b2aSVivek Goyal if (err < 0 && err != -ENODATA) 759993a0b2aSVivek Goyal goto out; 760993a0b2aSVivek Goyal } 761993a0b2aSVivek Goyal 7624f93b426SVivek Goyal err = ovl_copy_up_data(&datapath, &upperpath, c->stat.size); 7630c288874SVivek Goyal if (err) 764993a0b2aSVivek Goyal goto out_free; 765993a0b2aSVivek Goyal 766993a0b2aSVivek Goyal /* 767993a0b2aSVivek Goyal * Writing to upper file will clear security.capability xattr. We 768993a0b2aSVivek Goyal * don't want that to happen for normal copy-up operation. 769993a0b2aSVivek Goyal */ 770993a0b2aSVivek Goyal if (capability) { 771993a0b2aSVivek Goyal err = ovl_do_setxattr(upperpath.dentry, XATTR_NAME_CAPS, 772993a0b2aSVivek Goyal capability, cap_size, 0); 773993a0b2aSVivek Goyal if (err) 774993a0b2aSVivek Goyal goto out_free; 775993a0b2aSVivek Goyal } 776993a0b2aSVivek Goyal 7770c288874SVivek Goyal 7780c288874SVivek Goyal err = vfs_removexattr(upperpath.dentry, OVL_XATTR_METACOPY); 7790c288874SVivek Goyal if (err) 780993a0b2aSVivek Goyal goto out_free; 7810c288874SVivek Goyal 7820c288874SVivek Goyal ovl_set_upperdata(d_inode(c->dentry)); 783993a0b2aSVivek Goyal out_free: 784993a0b2aSVivek Goyal kfree(capability); 785993a0b2aSVivek Goyal out: 7860c288874SVivek Goyal return err; 7870c288874SVivek Goyal } 7880c288874SVivek Goyal 789a6fb235aSMiklos Szeredi static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, 790a6fb235aSMiklos Szeredi int flags) 791a6fb235aSMiklos Szeredi { 792a6fb235aSMiklos Szeredi int err; 793a6fb235aSMiklos Szeredi DEFINE_DELAYED_CALL(done); 794a6fb235aSMiklos Szeredi struct path parentpath; 795a6fb235aSMiklos Szeredi struct ovl_copy_up_ctx ctx = { 796a6fb235aSMiklos Szeredi .parent = parent, 797a6fb235aSMiklos Szeredi .dentry = dentry, 798a6fb235aSMiklos Szeredi .workdir = ovl_workdir(dentry), 799a6fb235aSMiklos Szeredi }; 800a6fb235aSMiklos Szeredi 801a6fb235aSMiklos Szeredi if (WARN_ON(!ctx.workdir)) 802a6fb235aSMiklos Szeredi return -EROFS; 803a6fb235aSMiklos Szeredi 804a6fb235aSMiklos Szeredi ovl_path_lower(dentry, &ctx.lowerpath); 805a6fb235aSMiklos Szeredi err = vfs_getattr(&ctx.lowerpath, &ctx.stat, 806a6fb235aSMiklos Szeredi STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT); 807a6fb235aSMiklos Szeredi if (err) 808a6fb235aSMiklos Szeredi return err; 809a6fb235aSMiklos Szeredi 81044d5bf10SVivek Goyal ctx.metacopy = ovl_need_meta_copy_up(dentry, ctx.stat.mode, flags); 81144d5bf10SVivek Goyal 812aa3ff3c1SAmir Goldstein if (parent) { 813a6fb235aSMiklos Szeredi ovl_path_upper(parent, &parentpath); 81459be0971SAmir Goldstein ctx.destdir = parentpath.dentry; 81559be0971SAmir Goldstein ctx.destname = dentry->d_name; 816a6fb235aSMiklos Szeredi 817a6fb235aSMiklos Szeredi err = vfs_getattr(&parentpath, &ctx.pstat, 818aa3ff3c1SAmir Goldstein STATX_ATIME | STATX_MTIME, 819aa3ff3c1SAmir Goldstein AT_STATX_SYNC_AS_STAT); 820a6fb235aSMiklos Szeredi if (err) 821a6fb235aSMiklos Szeredi return err; 822aa3ff3c1SAmir Goldstein } 823a6fb235aSMiklos Szeredi 824a6fb235aSMiklos Szeredi /* maybe truncate regular file. this has no effect on dirs */ 825a6fb235aSMiklos Szeredi if (flags & O_TRUNC) 826a6fb235aSMiklos Szeredi ctx.stat.size = 0; 827a6fb235aSMiklos Szeredi 828a6fb235aSMiklos Szeredi if (S_ISLNK(ctx.stat.mode)) { 829a6fb235aSMiklos Szeredi ctx.link = vfs_get_link(ctx.lowerpath.dentry, &done); 830a6fb235aSMiklos Szeredi if (IS_ERR(ctx.link)) 831a6fb235aSMiklos Szeredi return PTR_ERR(ctx.link); 832a6fb235aSMiklos Szeredi } 833a6fb235aSMiklos Szeredi 8340c288874SVivek Goyal err = ovl_copy_up_start(dentry, flags); 835fd210b7dSMiklos Szeredi /* err < 0: interrupted, err > 0: raced with another copy-up */ 836fd210b7dSMiklos Szeredi if (unlikely(err)) { 837fd210b7dSMiklos Szeredi if (err > 0) 838fd210b7dSMiklos Szeredi err = 0; 839fd210b7dSMiklos Szeredi } else { 84059be0971SAmir Goldstein if (!ovl_dentry_upper(dentry)) 841a6fb235aSMiklos Szeredi err = ovl_do_copy_up(&ctx); 842aa3ff3c1SAmir Goldstein if (!err && parent && !ovl_dentry_has_upper_alias(dentry)) 843f4439de1SAmir Goldstein err = ovl_link_up(&ctx); 8440c288874SVivek Goyal if (!err && ovl_dentry_needs_data_copy_up_locked(dentry, flags)) 8450c288874SVivek Goyal err = ovl_copy_up_meta_inode_data(&ctx); 846fd210b7dSMiklos Szeredi ovl_copy_up_end(dentry); 847fd210b7dSMiklos Szeredi } 8487764235bSMiklos Szeredi do_delayed_call(&done); 849e9be9d5eSMiklos Szeredi 850e9be9d5eSMiklos Szeredi return err; 851e9be9d5eSMiklos Szeredi } 852e9be9d5eSMiklos Szeredi 8539aba6521SAmir Goldstein int ovl_copy_up_flags(struct dentry *dentry, int flags) 854e9be9d5eSMiklos Szeredi { 8558eac98b8SVivek Goyal int err = 0; 8568eac98b8SVivek Goyal const struct cred *old_cred = ovl_override_creds(dentry->d_sb); 857aa3ff3c1SAmir Goldstein bool disconnected = (dentry->d_flags & DCACHE_DISCONNECTED); 858aa3ff3c1SAmir Goldstein 859aa3ff3c1SAmir Goldstein /* 860aa3ff3c1SAmir Goldstein * With NFS export, copy up can get called for a disconnected non-dir. 861aa3ff3c1SAmir Goldstein * In this case, we will copy up lower inode to index dir without 862aa3ff3c1SAmir Goldstein * linking it to upper dir. 863aa3ff3c1SAmir Goldstein */ 864aa3ff3c1SAmir Goldstein if (WARN_ON(disconnected && d_is_dir(dentry))) 865aa3ff3c1SAmir Goldstein return -EIO; 866e9be9d5eSMiklos Szeredi 867e9be9d5eSMiklos Szeredi while (!err) { 868e9be9d5eSMiklos Szeredi struct dentry *next; 869aa3ff3c1SAmir Goldstein struct dentry *parent = NULL; 870e9be9d5eSMiklos Szeredi 8710c288874SVivek Goyal if (ovl_already_copied_up(dentry, flags)) 872e9be9d5eSMiklos Szeredi break; 873e9be9d5eSMiklos Szeredi 874e9be9d5eSMiklos Szeredi next = dget(dentry); 875e9be9d5eSMiklos Szeredi /* find the topmost dentry not yet copied up */ 876aa3ff3c1SAmir Goldstein for (; !disconnected;) { 877e9be9d5eSMiklos Szeredi parent = dget_parent(next); 878e9be9d5eSMiklos Szeredi 87959be0971SAmir Goldstein if (ovl_dentry_upper(parent)) 880e9be9d5eSMiklos Szeredi break; 881e9be9d5eSMiklos Szeredi 882e9be9d5eSMiklos Szeredi dput(next); 883e9be9d5eSMiklos Szeredi next = parent; 884e9be9d5eSMiklos Szeredi } 885e9be9d5eSMiklos Szeredi 886a6fb235aSMiklos Szeredi err = ovl_copy_up_one(parent, next, flags); 887e9be9d5eSMiklos Szeredi 888e9be9d5eSMiklos Szeredi dput(parent); 889e9be9d5eSMiklos Szeredi dput(next); 890e9be9d5eSMiklos Szeredi } 8918eac98b8SVivek Goyal revert_creds(old_cred); 892e9be9d5eSMiklos Szeredi 893e9be9d5eSMiklos Szeredi return err; 894e9be9d5eSMiklos Szeredi } 8959aba6521SAmir Goldstein 896d6eac039SVivek Goyal static bool ovl_open_need_copy_up(struct dentry *dentry, int flags) 897d6eac039SVivek Goyal { 898d6eac039SVivek Goyal /* Copy up of disconnected dentry does not set upper alias */ 8990c288874SVivek Goyal if (ovl_already_copied_up(dentry, flags)) 900d6eac039SVivek Goyal return false; 901d6eac039SVivek Goyal 902d6eac039SVivek Goyal if (special_file(d_inode(dentry)->i_mode)) 903d6eac039SVivek Goyal return false; 904d6eac039SVivek Goyal 9050c288874SVivek Goyal if (!ovl_open_flags_need_copy_up(flags)) 906d6eac039SVivek Goyal return false; 907d6eac039SVivek Goyal 908d6eac039SVivek Goyal return true; 909d6eac039SVivek Goyal } 910d6eac039SVivek Goyal 9113428030dSAmir Goldstein int ovl_maybe_copy_up(struct dentry *dentry, int flags) 912d6eac039SVivek Goyal { 913d6eac039SVivek Goyal int err = 0; 914d6eac039SVivek Goyal 9153428030dSAmir Goldstein if (ovl_open_need_copy_up(dentry, flags)) { 916d6eac039SVivek Goyal err = ovl_want_write(dentry); 917d6eac039SVivek Goyal if (!err) { 9183428030dSAmir Goldstein err = ovl_copy_up_flags(dentry, flags); 919d6eac039SVivek Goyal ovl_drop_write(dentry); 920d6eac039SVivek Goyal } 921d6eac039SVivek Goyal } 922d6eac039SVivek Goyal 923d6eac039SVivek Goyal return err; 924d6eac039SVivek Goyal } 925d6eac039SVivek Goyal 926d1e6f6a9SVivek Goyal int ovl_copy_up_with_data(struct dentry *dentry) 927d1e6f6a9SVivek Goyal { 928d1e6f6a9SVivek Goyal return ovl_copy_up_flags(dentry, O_WRONLY); 929d1e6f6a9SVivek Goyal } 930d1e6f6a9SVivek Goyal 9319aba6521SAmir Goldstein int ovl_copy_up(struct dentry *dentry) 9329aba6521SAmir Goldstein { 9339aba6521SAmir Goldstein return ovl_copy_up_flags(dentry, 0); 9349aba6521SAmir Goldstein } 935