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struct kernel_param *param) 26fb5bb2c3SDavid Howells { 271bd0a3aeSlijiazi pr_warn("\"check_copy_up\" module option is obsolete\n"); 28fb5bb2c3SDavid Howells return 0; 29fb5bb2c3SDavid Howells } 30fb5bb2c3SDavid Howells 31670c2324SMiklos Szeredi static int ovl_ccup_get(char *buf, const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 39c61ca557SMiklos Szeredi static bool ovl_must_copy_xattr(const char *name) 40c61ca557SMiklos Szeredi { 41c61ca557SMiklos Szeredi return !strcmp(name, XATTR_POSIX_ACL_ACCESS) || 42c61ca557SMiklos Szeredi !strcmp(name, XATTR_POSIX_ACL_DEFAULT) || 43c61ca557SMiklos Szeredi !strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN); 44c61ca557SMiklos Szeredi } 45c61ca557SMiklos Szeredi 46610afc0bSMiklos Szeredi int ovl_copy_xattr(struct super_block *sb, struct dentry *old, 47610afc0bSMiklos Szeredi struct dentry *new) 48e9be9d5eSMiklos Szeredi { 49e4ad29faSVito Caputo ssize_t list_size, size, value_size = 0; 50e4ad29faSVito Caputo char *buf, *name, *value = NULL; 51520da69dSYuxuan Shui int error = 0; 528b326c61SMiklos Szeredi size_t slen; 53e9be9d5eSMiklos Szeredi 545d6c3191SAndreas Gruenbacher if (!(old->d_inode->i_opflags & IOP_XATTR) || 555d6c3191SAndreas Gruenbacher !(new->d_inode->i_opflags & IOP_XATTR)) 56e9be9d5eSMiklos Szeredi return 0; 57e9be9d5eSMiklos Szeredi 58e9be9d5eSMiklos Szeredi list_size = vfs_listxattr(old, NULL, 0); 59e9be9d5eSMiklos Szeredi if (list_size <= 0) { 60e9be9d5eSMiklos Szeredi if (list_size == -EOPNOTSUPP) 61e9be9d5eSMiklos Szeredi return 0; 62e9be9d5eSMiklos Szeredi return list_size; 63e9be9d5eSMiklos Szeredi } 64e9be9d5eSMiklos Szeredi 65e9be9d5eSMiklos Szeredi buf = kzalloc(list_size, GFP_KERNEL); 66e9be9d5eSMiklos Szeredi if (!buf) 67e9be9d5eSMiklos Szeredi return -ENOMEM; 68e9be9d5eSMiklos Szeredi 69e9be9d5eSMiklos Szeredi list_size = vfs_listxattr(old, buf, list_size); 70e9be9d5eSMiklos Szeredi if (list_size <= 0) { 71e9be9d5eSMiklos Szeredi error = list_size; 72e4ad29faSVito Caputo goto out; 73e9be9d5eSMiklos Szeredi } 74e9be9d5eSMiklos Szeredi 758b326c61SMiklos Szeredi for (name = buf; list_size; name += slen) { 768b326c61SMiklos Szeredi slen = strnlen(name, list_size) + 1; 778b326c61SMiklos Szeredi 788b326c61SMiklos Szeredi /* underlying fs providing us with an broken xattr list? */ 798b326c61SMiklos Szeredi if (WARN_ON(slen > list_size)) { 808b326c61SMiklos Szeredi error = -EIO; 818b326c61SMiklos Szeredi break; 828b326c61SMiklos Szeredi } 838b326c61SMiklos Szeredi list_size -= slen; 848b326c61SMiklos Szeredi 85610afc0bSMiklos Szeredi if (ovl_is_private_xattr(sb, name)) 860956254aSMiklos Szeredi continue; 87e4ad29faSVito Caputo retry: 88e4ad29faSVito Caputo size = vfs_getxattr(old, name, value, value_size); 89e4ad29faSVito Caputo if (size == -ERANGE) 90e4ad29faSVito Caputo size = vfs_getxattr(old, name, NULL, 0); 91e4ad29faSVito Caputo 9297daf8b9SMiklos Szeredi if (size < 0) { 93e9be9d5eSMiklos Szeredi error = size; 94e4ad29faSVito Caputo break; 95e9be9d5eSMiklos Szeredi } 96e9be9d5eSMiklos Szeredi 97e4ad29faSVito Caputo if (size > value_size) { 98e4ad29faSVito Caputo void *new; 99e4ad29faSVito Caputo 100e4ad29faSVito Caputo new = krealloc(value, size, GFP_KERNEL); 101e4ad29faSVito Caputo if (!new) { 102e4ad29faSVito Caputo error = -ENOMEM; 103e4ad29faSVito Caputo break; 104e4ad29faSVito Caputo } 105e4ad29faSVito Caputo value = new; 106e4ad29faSVito Caputo value_size = size; 107e4ad29faSVito Caputo goto retry; 108e4ad29faSVito Caputo } 109e4ad29faSVito Caputo 110121ab822SVivek Goyal error = security_inode_copy_up_xattr(name); 111121ab822SVivek Goyal if (error < 0 && error != -EOPNOTSUPP) 112121ab822SVivek Goyal break; 113121ab822SVivek Goyal if (error == 1) { 114121ab822SVivek Goyal error = 0; 115121ab822SVivek Goyal continue; /* Discard */ 116121ab822SVivek Goyal } 117e4ad29faSVito Caputo error = vfs_setxattr(new, name, value, size, 0); 118c61ca557SMiklos Szeredi if (error) { 119c61ca557SMiklos Szeredi if (error != -EOPNOTSUPP || ovl_must_copy_xattr(name)) 120e4ad29faSVito Caputo break; 121c61ca557SMiklos Szeredi 122c61ca557SMiklos Szeredi /* Ignore failure to copy unknown xattrs */ 123c61ca557SMiklos Szeredi error = 0; 124c61ca557SMiklos Szeredi } 125e4ad29faSVito Caputo } 126e9be9d5eSMiklos Szeredi kfree(value); 127e9be9d5eSMiklos Szeredi out: 128e9be9d5eSMiklos Szeredi kfree(buf); 129e9be9d5eSMiklos Szeredi return error; 130e9be9d5eSMiklos Szeredi } 131e9be9d5eSMiklos Szeredi 132c86243b0SVivek Goyal static int ovl_copy_up_data(struct ovl_fs *ofs, struct path *old, 133c86243b0SVivek Goyal struct path *new, loff_t len) 134e9be9d5eSMiklos Szeredi { 135e9be9d5eSMiklos Szeredi struct file *old_file; 136e9be9d5eSMiklos Szeredi struct file *new_file; 137e9be9d5eSMiklos Szeredi loff_t old_pos = 0; 138e9be9d5eSMiklos Szeredi loff_t new_pos = 0; 13942ec3d4cSDarrick J. Wong loff_t cloned; 140b504c654SChengguang Xu loff_t data_pos = -1; 141b504c654SChengguang Xu loff_t hole_len; 142b504c654SChengguang Xu bool skip_hole = false; 143e9be9d5eSMiklos Szeredi int error = 0; 144e9be9d5eSMiklos Szeredi 145e9be9d5eSMiklos Szeredi if (len == 0) 146e9be9d5eSMiklos Szeredi return 0; 147e9be9d5eSMiklos Szeredi 1480480334fSDavid Howells old_file = ovl_path_open(old, O_LARGEFILE | O_RDONLY); 149e9be9d5eSMiklos Szeredi if (IS_ERR(old_file)) 150e9be9d5eSMiklos Szeredi return PTR_ERR(old_file); 151e9be9d5eSMiklos Szeredi 1520480334fSDavid Howells new_file = ovl_path_open(new, O_LARGEFILE | O_WRONLY); 153e9be9d5eSMiklos Szeredi if (IS_ERR(new_file)) { 154e9be9d5eSMiklos Szeredi error = PTR_ERR(new_file); 155e9be9d5eSMiklos Szeredi goto out_fput; 156e9be9d5eSMiklos Szeredi } 157e9be9d5eSMiklos Szeredi 1582ea98466SAmir Goldstein /* Try to use clone_file_range to clone up within the same fs */ 159452ce659SDarrick J. Wong cloned = do_clone_file_range(old_file, 0, new_file, 0, len, 0); 16042ec3d4cSDarrick J. Wong if (cloned == len) 1612ea98466SAmir Goldstein goto out; 1622ea98466SAmir Goldstein /* Couldn't clone, so now we try to copy the data */ 1632ea98466SAmir Goldstein 164b504c654SChengguang Xu /* Check if lower fs supports seek operation */ 165b504c654SChengguang Xu if (old_file->f_mode & FMODE_LSEEK && 166b504c654SChengguang Xu old_file->f_op->llseek) 167b504c654SChengguang Xu skip_hole = true; 168b504c654SChengguang Xu 169e9be9d5eSMiklos Szeredi while (len) { 170e9be9d5eSMiklos Szeredi size_t this_len = OVL_COPY_UP_CHUNK_SIZE; 171e9be9d5eSMiklos Szeredi long bytes; 172e9be9d5eSMiklos Szeredi 173e9be9d5eSMiklos Szeredi if (len < this_len) 174e9be9d5eSMiklos Szeredi this_len = len; 175e9be9d5eSMiklos Szeredi 176e9be9d5eSMiklos Szeredi if (signal_pending_state(TASK_KILLABLE, current)) { 177e9be9d5eSMiklos Szeredi error = -EINTR; 178e9be9d5eSMiklos Szeredi break; 179e9be9d5eSMiklos Szeredi } 180e9be9d5eSMiklos Szeredi 181b504c654SChengguang Xu /* 182b504c654SChengguang Xu * Fill zero for hole will cost unnecessary disk space 183b504c654SChengguang Xu * and meanwhile slow down the copy-up speed, so we do 184b504c654SChengguang Xu * an optimization for hole during copy-up, it relies 185b504c654SChengguang Xu * on SEEK_DATA implementation in lower fs so if lower 186b504c654SChengguang Xu * fs does not support it, copy-up will behave as before. 187b504c654SChengguang Xu * 188b504c654SChengguang Xu * Detail logic of hole detection as below: 189b504c654SChengguang Xu * When we detect next data position is larger than current 190b504c654SChengguang Xu * position we will skip that hole, otherwise we copy 191b504c654SChengguang Xu * data in the size of OVL_COPY_UP_CHUNK_SIZE. Actually, 192b504c654SChengguang Xu * it may not recognize all kind of holes and sometimes 193b504c654SChengguang Xu * only skips partial of hole area. However, it will be 194b504c654SChengguang Xu * enough for most of the use cases. 195b504c654SChengguang Xu */ 196b504c654SChengguang Xu 197b504c654SChengguang Xu if (skip_hole && data_pos < old_pos) { 198b504c654SChengguang Xu data_pos = vfs_llseek(old_file, old_pos, SEEK_DATA); 199b504c654SChengguang Xu if (data_pos > old_pos) { 200b504c654SChengguang Xu hole_len = data_pos - old_pos; 201b504c654SChengguang Xu len -= hole_len; 202b504c654SChengguang Xu old_pos = new_pos = data_pos; 203b504c654SChengguang Xu continue; 204b504c654SChengguang Xu } else if (data_pos == -ENXIO) { 205b504c654SChengguang Xu break; 206b504c654SChengguang Xu } else if (data_pos < 0) { 207b504c654SChengguang Xu skip_hole = false; 208b504c654SChengguang Xu } 209b504c654SChengguang Xu } 210b504c654SChengguang Xu 211e9be9d5eSMiklos Szeredi bytes = do_splice_direct(old_file, &old_pos, 212e9be9d5eSMiklos Szeredi new_file, &new_pos, 213e9be9d5eSMiklos Szeredi this_len, SPLICE_F_MOVE); 214e9be9d5eSMiklos Szeredi if (bytes <= 0) { 215e9be9d5eSMiklos Szeredi error = bytes; 216e9be9d5eSMiklos Szeredi break; 217e9be9d5eSMiklos Szeredi } 218e9be9d5eSMiklos Szeredi WARN_ON(old_pos != new_pos); 219e9be9d5eSMiklos Szeredi 220e9be9d5eSMiklos Szeredi len -= bytes; 221e9be9d5eSMiklos Szeredi } 2222ea98466SAmir Goldstein out: 223c86243b0SVivek Goyal if (!error && ovl_should_sync(ofs)) 224641089c1SMiklos Szeredi error = vfs_fsync(new_file, 0); 225e9be9d5eSMiklos Szeredi fput(new_file); 226e9be9d5eSMiklos Szeredi out_fput: 227e9be9d5eSMiklos Szeredi fput(old_file); 228e9be9d5eSMiklos Szeredi return error; 229e9be9d5eSMiklos Szeredi } 230e9be9d5eSMiklos Szeredi 2310c288874SVivek Goyal static int ovl_set_size(struct dentry *upperdentry, struct kstat *stat) 2320c288874SVivek Goyal { 2330c288874SVivek Goyal struct iattr attr = { 2340c288874SVivek Goyal .ia_valid = ATTR_SIZE, 2350c288874SVivek Goyal .ia_size = stat->size, 2360c288874SVivek Goyal }; 2370c288874SVivek Goyal 2380c288874SVivek Goyal return notify_change(upperdentry, &attr, NULL); 2390c288874SVivek Goyal } 2400c288874SVivek Goyal 241e9be9d5eSMiklos Szeredi static int ovl_set_timestamps(struct dentry *upperdentry, struct kstat *stat) 242e9be9d5eSMiklos Szeredi { 243e9be9d5eSMiklos Szeredi struct iattr attr = { 244e9be9d5eSMiklos Szeredi .ia_valid = 245e9be9d5eSMiklos Szeredi ATTR_ATIME | ATTR_MTIME | ATTR_ATIME_SET | ATTR_MTIME_SET, 246e9be9d5eSMiklos Szeredi .ia_atime = stat->atime, 247e9be9d5eSMiklos Szeredi .ia_mtime = stat->mtime, 248e9be9d5eSMiklos Szeredi }; 249e9be9d5eSMiklos Szeredi 250e9be9d5eSMiklos Szeredi return notify_change(upperdentry, &attr, NULL); 251e9be9d5eSMiklos Szeredi } 252e9be9d5eSMiklos Szeredi 253e9be9d5eSMiklos Szeredi int ovl_set_attr(struct dentry *upperdentry, struct kstat *stat) 254e9be9d5eSMiklos Szeredi { 255e9be9d5eSMiklos Szeredi int err = 0; 256e9be9d5eSMiklos Szeredi 257e9be9d5eSMiklos Szeredi if (!S_ISLNK(stat->mode)) { 258e9be9d5eSMiklos Szeredi struct iattr attr = { 259e9be9d5eSMiklos Szeredi .ia_valid = ATTR_MODE, 260e9be9d5eSMiklos Szeredi .ia_mode = stat->mode, 261e9be9d5eSMiklos Szeredi }; 262e9be9d5eSMiklos Szeredi err = notify_change(upperdentry, &attr, NULL); 263e9be9d5eSMiklos Szeredi } 264e9be9d5eSMiklos Szeredi if (!err) { 265e9be9d5eSMiklos Szeredi struct iattr attr = { 266e9be9d5eSMiklos Szeredi .ia_valid = ATTR_UID | ATTR_GID, 267e9be9d5eSMiklos Szeredi .ia_uid = stat->uid, 268e9be9d5eSMiklos Szeredi .ia_gid = stat->gid, 269e9be9d5eSMiklos Szeredi }; 270e9be9d5eSMiklos Szeredi err = notify_change(upperdentry, &attr, NULL); 271e9be9d5eSMiklos Szeredi } 272e9be9d5eSMiklos Szeredi if (!err) 273e9be9d5eSMiklos Szeredi ovl_set_timestamps(upperdentry, stat); 274e9be9d5eSMiklos Szeredi 275e9be9d5eSMiklos Szeredi return err; 276e9be9d5eSMiklos Szeredi } 277e9be9d5eSMiklos Szeredi 2785b2cccd3SAmir Goldstein struct ovl_fh *ovl_encode_real_fh(struct dentry *real, bool is_upper) 2793a1e819bSAmir Goldstein { 2803a1e819bSAmir Goldstein struct ovl_fh *fh; 281ec7bbb53SAmir Goldstein int fh_type, dwords; 2823a1e819bSAmir Goldstein int buflen = MAX_HANDLE_SZ; 28305122443SAmir Goldstein uuid_t *uuid = &real->d_sb->s_uuid; 284ec7bbb53SAmir Goldstein int err; 2853a1e819bSAmir Goldstein 286ec7bbb53SAmir Goldstein /* Make sure the real fid stays 32bit aligned */ 287ec7bbb53SAmir Goldstein BUILD_BUG_ON(OVL_FH_FID_OFFSET % 4); 288ec7bbb53SAmir Goldstein BUILD_BUG_ON(MAX_HANDLE_SZ + OVL_FH_FID_OFFSET > 255); 289ec7bbb53SAmir Goldstein 290ec7bbb53SAmir Goldstein fh = kzalloc(buflen + OVL_FH_FID_OFFSET, GFP_KERNEL); 291ec7bbb53SAmir Goldstein if (!fh) 2923a1e819bSAmir Goldstein return ERR_PTR(-ENOMEM); 2933a1e819bSAmir Goldstein 2943a1e819bSAmir Goldstein /* 2953a1e819bSAmir Goldstein * We encode a non-connectable file handle for non-dir, because we 2963a1e819bSAmir Goldstein * only need to find the lower inode number and we don't want to pay 2973a1e819bSAmir Goldstein * the price or reconnecting the dentry. 2983a1e819bSAmir Goldstein */ 2993a1e819bSAmir Goldstein dwords = buflen >> 2; 300ec7bbb53SAmir Goldstein fh_type = exportfs_encode_fh(real, (void *)fh->fb.fid, &dwords, 0); 3013a1e819bSAmir Goldstein buflen = (dwords << 2); 3023a1e819bSAmir Goldstein 303ec7bbb53SAmir Goldstein err = -EIO; 3043a1e819bSAmir Goldstein if (WARN_ON(fh_type < 0) || 3053a1e819bSAmir Goldstein WARN_ON(buflen > MAX_HANDLE_SZ) || 3063a1e819bSAmir Goldstein WARN_ON(fh_type == FILEID_INVALID)) 307ec7bbb53SAmir Goldstein goto out_err; 3083a1e819bSAmir Goldstein 309cbe7fba8SAmir Goldstein fh->fb.version = OVL_FH_VERSION; 310cbe7fba8SAmir Goldstein fh->fb.magic = OVL_FH_MAGIC; 311cbe7fba8SAmir Goldstein fh->fb.type = fh_type; 312cbe7fba8SAmir Goldstein fh->fb.flags = OVL_FH_FLAG_CPU_ENDIAN; 31354fb347eSAmir Goldstein /* 31454fb347eSAmir Goldstein * When we will want to decode an overlay dentry from this handle 31554fb347eSAmir Goldstein * and all layers are on the same fs, if we get a disconncted real 31654fb347eSAmir Goldstein * dentry when we decode fid, the only way to tell if we should assign 31754fb347eSAmir Goldstein * it to upperdentry or to lowerstack is by checking this flag. 31854fb347eSAmir Goldstein */ 31954fb347eSAmir Goldstein if (is_upper) 320cbe7fba8SAmir Goldstein fh->fb.flags |= OVL_FH_FLAG_PATH_UPPER; 321ec7bbb53SAmir Goldstein fh->fb.len = sizeof(fh->fb) + buflen; 322cbe7fba8SAmir Goldstein fh->fb.uuid = *uuid; 3233a1e819bSAmir Goldstein 3243a1e819bSAmir Goldstein return fh; 325ec7bbb53SAmir Goldstein 326ec7bbb53SAmir Goldstein out_err: 327ec7bbb53SAmir Goldstein kfree(fh); 328ec7bbb53SAmir Goldstein return ERR_PTR(err); 3293a1e819bSAmir Goldstein } 3303a1e819bSAmir Goldstein 3319678e630SAmir Goldstein int ovl_set_origin(struct dentry *dentry, struct dentry *lower, 3323a1e819bSAmir Goldstein struct dentry *upper) 3333a1e819bSAmir Goldstein { 3343a1e819bSAmir Goldstein const struct ovl_fh *fh = NULL; 3353a1e819bSAmir Goldstein int err; 3363a1e819bSAmir Goldstein 3373a1e819bSAmir Goldstein /* 3383a1e819bSAmir Goldstein * When lower layer doesn't support export operations store a 'null' fh, 3393a1e819bSAmir Goldstein * so we can use the overlay.origin xattr to distignuish between a copy 3403a1e819bSAmir Goldstein * up and a pure upper inode. 3413a1e819bSAmir Goldstein */ 34202bcd157SAmir Goldstein if (ovl_can_decode_fh(lower->d_sb)) { 3435b2cccd3SAmir Goldstein fh = ovl_encode_real_fh(lower, false); 3443a1e819bSAmir Goldstein if (IS_ERR(fh)) 3453a1e819bSAmir Goldstein return PTR_ERR(fh); 3463a1e819bSAmir Goldstein } 3473a1e819bSAmir Goldstein 3486266d465SMiklos Szeredi /* 3496266d465SMiklos Szeredi * Do not fail when upper doesn't support xattrs. 3506266d465SMiklos Szeredi */ 351cbe7fba8SAmir Goldstein err = ovl_check_setxattr(dentry, upper, OVL_XATTR_ORIGIN, fh->buf, 352cbe7fba8SAmir Goldstein fh ? fh->fb.len : 0, 0); 3533a1e819bSAmir Goldstein kfree(fh); 3543a1e819bSAmir Goldstein 3553a1e819bSAmir Goldstein return err; 3563a1e819bSAmir Goldstein } 3573a1e819bSAmir Goldstein 358016b720fSAmir Goldstein /* Store file handle of @upper dir in @index dir entry */ 359610afc0bSMiklos Szeredi static int ovl_set_upper_fh(struct ovl_fs *ofs, struct dentry *upper, 360610afc0bSMiklos Szeredi struct dentry *index) 361016b720fSAmir Goldstein { 362016b720fSAmir Goldstein const struct ovl_fh *fh; 363016b720fSAmir Goldstein int err; 364016b720fSAmir Goldstein 3655b2cccd3SAmir Goldstein fh = ovl_encode_real_fh(upper, true); 366016b720fSAmir Goldstein if (IS_ERR(fh)) 367016b720fSAmir Goldstein return PTR_ERR(fh); 368016b720fSAmir Goldstein 369610afc0bSMiklos Szeredi err = ovl_do_setxattr(ofs, index, OVL_XATTR_UPPER, fh->buf, fh->fb.len); 370016b720fSAmir Goldstein 371016b720fSAmir Goldstein kfree(fh); 372016b720fSAmir Goldstein return err; 373016b720fSAmir Goldstein } 374016b720fSAmir Goldstein 375016b720fSAmir Goldstein /* 376016b720fSAmir Goldstein * Create and install index entry. 377016b720fSAmir Goldstein * 378016b720fSAmir Goldstein * Caller must hold i_mutex on indexdir. 379016b720fSAmir Goldstein */ 380016b720fSAmir Goldstein static int ovl_create_index(struct dentry *dentry, struct dentry *origin, 381016b720fSAmir Goldstein struct dentry *upper) 382016b720fSAmir Goldstein { 383016b720fSAmir Goldstein struct dentry *indexdir = ovl_indexdir(dentry->d_sb); 384016b720fSAmir Goldstein struct inode *dir = d_inode(indexdir); 385016b720fSAmir Goldstein struct dentry *index = NULL; 386016b720fSAmir Goldstein struct dentry *temp = NULL; 387016b720fSAmir Goldstein struct qstr name = { }; 388016b720fSAmir Goldstein int err; 389016b720fSAmir Goldstein 390016b720fSAmir Goldstein /* 391016b720fSAmir Goldstein * For now this is only used for creating index entry for directories, 392016b720fSAmir Goldstein * because non-dir are copied up directly to index and then hardlinked 393016b720fSAmir Goldstein * to upper dir. 394016b720fSAmir Goldstein * 395016b720fSAmir Goldstein * TODO: implement create index for non-dir, so we can call it when 396016b720fSAmir Goldstein * encoding file handle for non-dir in case index does not exist. 397016b720fSAmir Goldstein */ 398016b720fSAmir Goldstein if (WARN_ON(!d_is_dir(dentry))) 399016b720fSAmir Goldstein return -EIO; 400016b720fSAmir Goldstein 401016b720fSAmir Goldstein /* Directory not expected to be indexed before copy up */ 402016b720fSAmir Goldstein if (WARN_ON(ovl_test_flag(OVL_INDEX, d_inode(dentry)))) 403016b720fSAmir Goldstein return -EIO; 404016b720fSAmir Goldstein 405016b720fSAmir Goldstein err = ovl_get_index_name(origin, &name); 406016b720fSAmir Goldstein if (err) 407016b720fSAmir Goldstein return err; 408016b720fSAmir Goldstein 409137ec526SAmir Goldstein temp = ovl_create_temp(indexdir, OVL_CATTR(S_IFDIR | 0)); 410b148cba4SMiklos Szeredi err = PTR_ERR(temp); 411016b720fSAmir Goldstein if (IS_ERR(temp)) 412b148cba4SMiklos Szeredi goto free_name; 413016b720fSAmir Goldstein 414610afc0bSMiklos Szeredi err = ovl_set_upper_fh(OVL_FS(dentry->d_sb), upper, temp); 415016b720fSAmir Goldstein if (err) 416b148cba4SMiklos Szeredi goto out; 417016b720fSAmir Goldstein 418016b720fSAmir Goldstein index = lookup_one_len(name.name, indexdir, name.len); 419016b720fSAmir Goldstein if (IS_ERR(index)) { 420016b720fSAmir Goldstein err = PTR_ERR(index); 421016b720fSAmir Goldstein } else { 422016b720fSAmir Goldstein err = ovl_do_rename(dir, temp, dir, index, 0); 423016b720fSAmir Goldstein dput(index); 424016b720fSAmir Goldstein } 425016b720fSAmir Goldstein out: 426b148cba4SMiklos Szeredi if (err) 427b148cba4SMiklos Szeredi ovl_cleanup(dir, temp); 428016b720fSAmir Goldstein dput(temp); 429b148cba4SMiklos Szeredi free_name: 430016b720fSAmir Goldstein kfree(name.name); 431016b720fSAmir Goldstein return err; 432016b720fSAmir Goldstein } 433016b720fSAmir Goldstein 43423f0ab13SMiklos Szeredi struct ovl_copy_up_ctx { 435a6fb235aSMiklos Szeredi struct dentry *parent; 43623f0ab13SMiklos Szeredi struct dentry *dentry; 43723f0ab13SMiklos Szeredi struct path lowerpath; 43823f0ab13SMiklos Szeredi struct kstat stat; 43923f0ab13SMiklos Szeredi struct kstat pstat; 44023f0ab13SMiklos Szeredi const char *link; 44159be0971SAmir Goldstein struct dentry *destdir; 44259be0971SAmir Goldstein struct qstr destname; 44323f0ab13SMiklos Szeredi struct dentry *workdir; 44459be0971SAmir Goldstein bool origin; 445016b720fSAmir Goldstein bool indexed; 44644d5bf10SVivek Goyal bool metacopy; 44723f0ab13SMiklos Szeredi }; 44823f0ab13SMiklos Szeredi 449f4439de1SAmir Goldstein static int ovl_link_up(struct ovl_copy_up_ctx *c) 450f4439de1SAmir Goldstein { 451f4439de1SAmir Goldstein int err; 452f4439de1SAmir Goldstein struct dentry *upper; 453f4439de1SAmir Goldstein struct dentry *upperdir = ovl_dentry_upper(c->parent); 454f4439de1SAmir Goldstein struct inode *udir = d_inode(upperdir); 455f4439de1SAmir Goldstein 456f4439de1SAmir Goldstein /* Mark parent "impure" because it may now contain non-pure upper */ 457f4439de1SAmir Goldstein err = ovl_set_impure(c->parent, upperdir); 458f4439de1SAmir Goldstein if (err) 459f4439de1SAmir Goldstein return err; 460f4439de1SAmir Goldstein 461f4439de1SAmir Goldstein err = ovl_set_nlink_lower(c->dentry); 462f4439de1SAmir Goldstein if (err) 463f4439de1SAmir Goldstein return err; 464f4439de1SAmir Goldstein 465f4439de1SAmir Goldstein inode_lock_nested(udir, I_MUTEX_PARENT); 466f4439de1SAmir Goldstein upper = lookup_one_len(c->dentry->d_name.name, upperdir, 467f4439de1SAmir Goldstein c->dentry->d_name.len); 468f4439de1SAmir Goldstein err = PTR_ERR(upper); 469f4439de1SAmir Goldstein if (!IS_ERR(upper)) { 4706cf00764SAmir Goldstein err = ovl_do_link(ovl_dentry_upper(c->dentry), udir, upper); 471f4439de1SAmir Goldstein dput(upper); 472f4439de1SAmir Goldstein 473f4439de1SAmir Goldstein if (!err) { 474f4439de1SAmir Goldstein /* Restore timestamps on parent (best effort) */ 475f4439de1SAmir Goldstein ovl_set_timestamps(upperdir, &c->pstat); 476f4439de1SAmir Goldstein ovl_dentry_set_upper_alias(c->dentry); 477f4439de1SAmir Goldstein } 478f4439de1SAmir Goldstein } 479f4439de1SAmir Goldstein inode_unlock(udir); 480aa3ff3c1SAmir Goldstein if (err) 481aa3ff3c1SAmir Goldstein return err; 482aa3ff3c1SAmir Goldstein 483aa3ff3c1SAmir Goldstein err = ovl_set_nlink_upper(c->dentry); 484f4439de1SAmir Goldstein 485f4439de1SAmir Goldstein return err; 486f4439de1SAmir Goldstein } 487f4439de1SAmir Goldstein 48823f0ab13SMiklos Szeredi static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp) 48902209d10SAmir Goldstein { 490c86243b0SVivek Goyal struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); 49102209d10SAmir Goldstein int err; 49202209d10SAmir Goldstein 4935f32879eSVivek Goyal /* 4945f32879eSVivek Goyal * Copy up data first and then xattrs. Writing data after 4955f32879eSVivek Goyal * xattrs will remove security.capability xattr automatically. 4965f32879eSVivek Goyal */ 4975f32879eSVivek Goyal if (S_ISREG(c->stat.mode) && !c->metacopy) { 4985f32879eSVivek Goyal struct path upperpath, datapath; 4995f32879eSVivek Goyal 5005f32879eSVivek Goyal ovl_path_upper(c->dentry, &upperpath); 5015f32879eSVivek Goyal if (WARN_ON(upperpath.dentry != NULL)) 5025f32879eSVivek Goyal return -EIO; 5035f32879eSVivek Goyal upperpath.dentry = temp; 5045f32879eSVivek Goyal 5055f32879eSVivek Goyal ovl_path_lowerdata(c->dentry, &datapath); 506c86243b0SVivek Goyal err = ovl_copy_up_data(ofs, &datapath, &upperpath, 507c86243b0SVivek Goyal c->stat.size); 5085f32879eSVivek Goyal if (err) 5095f32879eSVivek Goyal return err; 5105f32879eSVivek Goyal } 5115f32879eSVivek Goyal 512610afc0bSMiklos Szeredi err = ovl_copy_xattr(c->dentry->d_sb, c->lowerpath.dentry, temp); 51302209d10SAmir Goldstein if (err) 51402209d10SAmir Goldstein return err; 51502209d10SAmir Goldstein 51602209d10SAmir Goldstein /* 51702209d10SAmir Goldstein * Store identifier of lower inode in upper inode xattr to 51802209d10SAmir Goldstein * allow lookup of the copy up origin inode. 51902209d10SAmir Goldstein * 52002209d10SAmir Goldstein * Don't set origin when we are breaking the association with a lower 52102209d10SAmir Goldstein * hard link. 52202209d10SAmir Goldstein */ 52359be0971SAmir Goldstein if (c->origin) { 52423f0ab13SMiklos Szeredi err = ovl_set_origin(c->dentry, c->lowerpath.dentry, temp); 52502209d10SAmir Goldstein if (err) 52602209d10SAmir Goldstein return err; 52702209d10SAmir Goldstein } 52802209d10SAmir Goldstein 5290c288874SVivek Goyal if (c->metacopy) { 5300c288874SVivek Goyal err = ovl_check_setxattr(c->dentry, temp, OVL_XATTR_METACOPY, 5310c288874SVivek Goyal NULL, 0, -EOPNOTSUPP); 5320c288874SVivek Goyal if (err) 5330c288874SVivek Goyal return err; 5340c288874SVivek Goyal } 5350c288874SVivek Goyal 536bd64e575SVivek Goyal inode_lock(temp->d_inode); 537b504c654SChengguang Xu if (S_ISREG(c->stat.mode)) 5380c288874SVivek Goyal err = ovl_set_size(temp, &c->stat); 5390c288874SVivek Goyal if (!err) 540bd64e575SVivek Goyal err = ovl_set_attr(temp, &c->stat); 541bd64e575SVivek Goyal inode_unlock(temp->d_inode); 542bd64e575SVivek Goyal 543bd64e575SVivek Goyal return err; 54402209d10SAmir Goldstein } 54502209d10SAmir Goldstein 5466b52243fSMiklos Szeredi struct ovl_cu_creds { 5476b52243fSMiklos Szeredi const struct cred *old; 5486b52243fSMiklos Szeredi struct cred *new; 549b10cdcdcSAmir Goldstein }; 550b10cdcdcSAmir Goldstein 5516b52243fSMiklos Szeredi static int ovl_prep_cu_creds(struct dentry *dentry, struct ovl_cu_creds *cc) 552b10cdcdcSAmir Goldstein { 553b10cdcdcSAmir Goldstein int err; 554b10cdcdcSAmir Goldstein 5556b52243fSMiklos Szeredi cc->old = cc->new = NULL; 5566b52243fSMiklos Szeredi err = security_inode_copy_up(dentry, &cc->new); 5576b52243fSMiklos Szeredi if (err < 0) 558b10cdcdcSAmir Goldstein return err; 5596b52243fSMiklos Szeredi 5606b52243fSMiklos Szeredi if (cc->new) 5616b52243fSMiklos Szeredi cc->old = override_creds(cc->new); 5626b52243fSMiklos Szeredi 5636b52243fSMiklos Szeredi return 0; 5646b52243fSMiklos Szeredi } 5656b52243fSMiklos Szeredi 5666b52243fSMiklos Szeredi static void ovl_revert_cu_creds(struct ovl_cu_creds *cc) 5676b52243fSMiklos Szeredi { 5686b52243fSMiklos Szeredi if (cc->new) { 5696b52243fSMiklos Szeredi revert_creds(cc->old); 5706b52243fSMiklos Szeredi put_cred(cc->new); 5716b52243fSMiklos Szeredi } 572b10cdcdcSAmir Goldstein } 573b10cdcdcSAmir Goldstein 574b10cdcdcSAmir Goldstein /* 575b10cdcdcSAmir Goldstein * Copyup using workdir to prepare temp file. Used when copying up directories, 576b10cdcdcSAmir Goldstein * special files or when upper fs doesn't support O_TMPFILE. 577b10cdcdcSAmir Goldstein */ 578b10cdcdcSAmir Goldstein static int ovl_copy_up_workdir(struct ovl_copy_up_ctx *c) 579b10cdcdcSAmir Goldstein { 580b79e05aaSAmir Goldstein struct inode *inode; 5816b52243fSMiklos Szeredi struct inode *udir = d_inode(c->destdir), *wdir = d_inode(c->workdir); 5826b52243fSMiklos Szeredi struct dentry *temp, *upper; 5836b52243fSMiklos Szeredi struct ovl_cu_creds cc; 5847d90b853SMiklos Szeredi int err; 5856b52243fSMiklos Szeredi struct ovl_cattr cattr = { 5866b52243fSMiklos Szeredi /* Can't properly set mode on creation because of the umask */ 5876b52243fSMiklos Szeredi .mode = c->stat.mode & S_IFMT, 5886b52243fSMiklos Szeredi .rdev = c->stat.rdev, 5896b52243fSMiklos Szeredi .link = c->link 5906b52243fSMiklos Szeredi }; 5917d90b853SMiklos Szeredi 592773cb4c5SAmir Goldstein /* workdir and destdir could be the same when copying up to indexdir */ 593773cb4c5SAmir Goldstein err = -EIO; 594773cb4c5SAmir Goldstein if (lock_rename(c->workdir, c->destdir) != NULL) 595773cb4c5SAmir Goldstein goto unlock; 596b10cdcdcSAmir Goldstein 5976b52243fSMiklos Szeredi err = ovl_prep_cu_creds(c->dentry, &cc); 5986b52243fSMiklos Szeredi if (err) 5996b52243fSMiklos Szeredi goto unlock; 6006b52243fSMiklos Szeredi 6016b52243fSMiklos Szeredi temp = ovl_create_temp(c->workdir, &cattr); 6026b52243fSMiklos Szeredi ovl_revert_cu_creds(&cc); 6036b52243fSMiklos Szeredi 604b10cdcdcSAmir Goldstein err = PTR_ERR(temp); 605b10cdcdcSAmir Goldstein if (IS_ERR(temp)) 606b10cdcdcSAmir Goldstein goto unlock; 607b10cdcdcSAmir Goldstein 608b10cdcdcSAmir Goldstein err = ovl_copy_up_inode(c, temp); 609b10cdcdcSAmir Goldstein if (err) 610b10cdcdcSAmir Goldstein goto cleanup; 611b10cdcdcSAmir Goldstein 612b10cdcdcSAmir Goldstein if (S_ISDIR(c->stat.mode) && c->indexed) { 613b10cdcdcSAmir Goldstein err = ovl_create_index(c->dentry, c->lowerpath.dentry, temp); 614b10cdcdcSAmir Goldstein if (err) 615b10cdcdcSAmir Goldstein goto cleanup; 616b10cdcdcSAmir Goldstein } 617b10cdcdcSAmir Goldstein 6186b52243fSMiklos Szeredi upper = lookup_one_len(c->destname.name, c->destdir, c->destname.len); 6196b52243fSMiklos Szeredi err = PTR_ERR(upper); 6206b52243fSMiklos Szeredi if (IS_ERR(upper)) 6216b52243fSMiklos Szeredi goto cleanup; 6226b52243fSMiklos Szeredi 6236b52243fSMiklos Szeredi err = ovl_do_rename(wdir, temp, udir, upper, 0); 6246b52243fSMiklos Szeredi dput(upper); 625b10cdcdcSAmir Goldstein if (err) 626b10cdcdcSAmir Goldstein goto cleanup; 627b10cdcdcSAmir Goldstein 628b10cdcdcSAmir Goldstein if (!c->metacopy) 629b10cdcdcSAmir Goldstein ovl_set_upperdata(d_inode(c->dentry)); 630b10cdcdcSAmir Goldstein inode = d_inode(c->dentry); 6316b52243fSMiklos Szeredi ovl_inode_update(inode, temp); 632b10cdcdcSAmir Goldstein if (S_ISDIR(inode->i_mode)) 633b10cdcdcSAmir Goldstein ovl_set_flag(OVL_WHITEOUTS, inode); 634b10cdcdcSAmir Goldstein unlock: 635b10cdcdcSAmir Goldstein unlock_rename(c->workdir, c->destdir); 636b10cdcdcSAmir Goldstein 637b10cdcdcSAmir Goldstein return err; 638b10cdcdcSAmir Goldstein 639b10cdcdcSAmir Goldstein cleanup: 6406b52243fSMiklos Szeredi ovl_cleanup(wdir, temp); 6416b52243fSMiklos Szeredi dput(temp); 642b10cdcdcSAmir Goldstein goto unlock; 643b10cdcdcSAmir Goldstein } 644b10cdcdcSAmir Goldstein 645b10cdcdcSAmir Goldstein /* Copyup using O_TMPFILE which does not require cross dir locking */ 646b10cdcdcSAmir Goldstein static int ovl_copy_up_tmpfile(struct ovl_copy_up_ctx *c) 647b10cdcdcSAmir Goldstein { 6486b52243fSMiklos Szeredi struct inode *udir = d_inode(c->destdir); 6496b52243fSMiklos Szeredi struct dentry *temp, *upper; 6506b52243fSMiklos Szeredi struct ovl_cu_creds cc; 651b10cdcdcSAmir Goldstein int err; 652b10cdcdcSAmir Goldstein 6536b52243fSMiklos Szeredi err = ovl_prep_cu_creds(c->dentry, &cc); 6546b52243fSMiklos Szeredi if (err) 6556b52243fSMiklos Szeredi return err; 6566b52243fSMiklos Szeredi 6576b52243fSMiklos Szeredi temp = ovl_do_tmpfile(c->workdir, c->stat.mode); 6586b52243fSMiklos Szeredi ovl_revert_cu_creds(&cc); 6596b52243fSMiklos Szeredi 660b148cba4SMiklos Szeredi if (IS_ERR(temp)) 661b148cba4SMiklos Szeredi return PTR_ERR(temp); 662e9be9d5eSMiklos Szeredi 66323f0ab13SMiklos Szeredi err = ovl_copy_up_inode(c, temp); 664e9be9d5eSMiklos Szeredi if (err) 6656b52243fSMiklos Szeredi goto out_dput; 6663a1e819bSAmir Goldstein 6676b52243fSMiklos Szeredi inode_lock_nested(udir, I_MUTEX_PARENT); 6686b52243fSMiklos Szeredi 6696b52243fSMiklos Szeredi upper = lookup_one_len(c->destname.name, c->destdir, c->destname.len); 6706b52243fSMiklos Szeredi err = PTR_ERR(upper); 6716b52243fSMiklos Szeredi if (!IS_ERR(upper)) { 6726b52243fSMiklos Szeredi err = ovl_do_link(temp, udir, upper); 6736b52243fSMiklos Szeredi dput(upper); 6746b52243fSMiklos Szeredi } 6756b52243fSMiklos Szeredi inode_unlock(udir); 6766b52243fSMiklos Szeredi 677e9be9d5eSMiklos Szeredi if (err) 6786b52243fSMiklos Szeredi goto out_dput; 679e9be9d5eSMiklos Szeredi 6800c288874SVivek Goyal if (!c->metacopy) 6810c288874SVivek Goyal ovl_set_upperdata(d_inode(c->dentry)); 6826b52243fSMiklos Szeredi ovl_inode_update(d_inode(c->dentry), temp); 683b79e05aaSAmir Goldstein 6846b52243fSMiklos Szeredi return 0; 6856b52243fSMiklos Szeredi 6866b52243fSMiklos Szeredi out_dput: 687e85f82ffSMiklos Szeredi dput(temp); 688e9be9d5eSMiklos Szeredi return err; 689e9be9d5eSMiklos Szeredi } 690e9be9d5eSMiklos Szeredi 691e9be9d5eSMiklos Szeredi /* 692e9be9d5eSMiklos Szeredi * Copy up a single dentry 693e9be9d5eSMiklos Szeredi * 694a6c60655SMiklos Szeredi * All renames start with copy up of source if necessary. The actual 695a6c60655SMiklos Szeredi * rename will only proceed once the copy up was successful. Copy up uses 696a6c60655SMiklos Szeredi * upper parent i_mutex for exclusion. Since rename can change d_parent it 697a6c60655SMiklos Szeredi * is possible that the copy up will lock the old parent. At that point 698a6c60655SMiklos Szeredi * the file will have already been copied up anyway. 699e9be9d5eSMiklos Szeredi */ 700a6fb235aSMiklos Szeredi static int ovl_do_copy_up(struct ovl_copy_up_ctx *c) 701e9be9d5eSMiklos Szeredi { 702e9be9d5eSMiklos Szeredi int err; 70323f0ab13SMiklos Szeredi struct ovl_fs *ofs = c->dentry->d_sb->s_fs_info; 704016b720fSAmir Goldstein bool to_index = false; 70559be0971SAmir Goldstein 706016b720fSAmir Goldstein /* 707016b720fSAmir Goldstein * Indexed non-dir is copied up directly to the index entry and then 708016b720fSAmir Goldstein * hardlinked to upper dir. Indexed dir is copied up to indexdir, 709016b720fSAmir Goldstein * then index entry is created and then copied up dir installed. 710016b720fSAmir Goldstein * Copying dir up to indexdir instead of workdir simplifies locking. 711016b720fSAmir Goldstein */ 712016b720fSAmir Goldstein if (ovl_need_index(c->dentry)) { 713016b720fSAmir Goldstein c->indexed = true; 714016b720fSAmir Goldstein if (S_ISDIR(c->stat.mode)) 715016b720fSAmir Goldstein c->workdir = ovl_indexdir(c->dentry->d_sb); 716016b720fSAmir Goldstein else 717016b720fSAmir Goldstein to_index = true; 718016b720fSAmir Goldstein } 719016b720fSAmir Goldstein 720016b720fSAmir Goldstein if (S_ISDIR(c->stat.mode) || c->stat.nlink == 1 || to_index) 72159be0971SAmir Goldstein c->origin = true; 72259be0971SAmir Goldstein 723016b720fSAmir Goldstein if (to_index) { 72459be0971SAmir Goldstein c->destdir = ovl_indexdir(c->dentry->d_sb); 72559be0971SAmir Goldstein err = ovl_get_index_name(c->lowerpath.dentry, &c->destname); 726f3a15685SAmir Goldstein if (err) 727f3a15685SAmir Goldstein return err; 728aa3ff3c1SAmir Goldstein } else if (WARN_ON(!c->parent)) { 729aa3ff3c1SAmir Goldstein /* Disconnected dentry must be copied up to index dir */ 730aa3ff3c1SAmir Goldstein return -EIO; 73159be0971SAmir Goldstein } else { 73259be0971SAmir Goldstein /* 73359be0971SAmir Goldstein * Mark parent "impure" because it may now contain non-pure 73459be0971SAmir Goldstein * upper 73559be0971SAmir Goldstein */ 73659be0971SAmir Goldstein err = ovl_set_impure(c->parent, c->destdir); 73759be0971SAmir Goldstein if (err) 73859be0971SAmir Goldstein return err; 73959be0971SAmir Goldstein } 740f3a15685SAmir Goldstein 74101ad3eb8SAmir Goldstein /* Should we copyup with O_TMPFILE or with workdir? */ 742b10cdcdcSAmir Goldstein if (S_ISREG(c->stat.mode) && ofs->tmpfile) 743b10cdcdcSAmir Goldstein err = ovl_copy_up_tmpfile(c); 744b10cdcdcSAmir Goldstein else 745b10cdcdcSAmir Goldstein err = ovl_copy_up_workdir(c); 746aa3ff3c1SAmir Goldstein if (err) 747aa3ff3c1SAmir Goldstein goto out; 748aa3ff3c1SAmir Goldstein 749aa3ff3c1SAmir Goldstein if (c->indexed) 75059be0971SAmir Goldstein ovl_set_flag(OVL_INDEX, d_inode(c->dentry)); 751016b720fSAmir Goldstein 752016b720fSAmir Goldstein if (to_index) { 753aa3ff3c1SAmir Goldstein /* Initialize nlink for copy up of disconnected dentry */ 754aa3ff3c1SAmir Goldstein err = ovl_set_nlink_upper(c->dentry); 755aa3ff3c1SAmir Goldstein } else { 75659be0971SAmir Goldstein struct inode *udir = d_inode(c->destdir); 75759be0971SAmir Goldstein 75859be0971SAmir Goldstein /* Restore timestamps on parent (best effort) */ 75959be0971SAmir Goldstein inode_lock(udir); 76059be0971SAmir Goldstein ovl_set_timestamps(c->destdir, &c->pstat); 76159be0971SAmir Goldstein inode_unlock(udir); 76259be0971SAmir Goldstein 76359be0971SAmir Goldstein ovl_dentry_set_upper_alias(c->dentry); 764fd210b7dSMiklos Szeredi } 765a6fb235aSMiklos Szeredi 766aa3ff3c1SAmir Goldstein out: 767aa3ff3c1SAmir Goldstein if (to_index) 768aa3ff3c1SAmir Goldstein kfree(c->destname.name); 769a6fb235aSMiklos Szeredi return err; 770a6fb235aSMiklos Szeredi } 771a6fb235aSMiklos Szeredi 77244d5bf10SVivek Goyal static bool ovl_need_meta_copy_up(struct dentry *dentry, umode_t mode, 77344d5bf10SVivek Goyal int flags) 77444d5bf10SVivek Goyal { 77544d5bf10SVivek Goyal struct ovl_fs *ofs = dentry->d_sb->s_fs_info; 77644d5bf10SVivek Goyal 77744d5bf10SVivek Goyal if (!ofs->config.metacopy) 77844d5bf10SVivek Goyal return false; 77944d5bf10SVivek Goyal 78044d5bf10SVivek Goyal if (!S_ISREG(mode)) 78144d5bf10SVivek Goyal return false; 78244d5bf10SVivek Goyal 78344d5bf10SVivek Goyal if (flags && ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC))) 78444d5bf10SVivek Goyal return false; 78544d5bf10SVivek Goyal 78644d5bf10SVivek Goyal return true; 78744d5bf10SVivek Goyal } 78844d5bf10SVivek Goyal 789de7a52c9SMiklos Szeredi static ssize_t ovl_getxattr(struct dentry *dentry, char *name, char **value) 790fee0f298SMiklos Szeredi { 791fee0f298SMiklos Szeredi ssize_t res; 792de7a52c9SMiklos Szeredi char *buf; 793fee0f298SMiklos Szeredi 794fee0f298SMiklos Szeredi res = vfs_getxattr(dentry, name, NULL, 0); 795fee0f298SMiklos Szeredi if (res == -ENODATA || res == -EOPNOTSUPP) 796de7a52c9SMiklos Szeredi res = 0; 797fee0f298SMiklos Szeredi 798de7a52c9SMiklos Szeredi if (res > 0) { 799de7a52c9SMiklos Szeredi buf = kzalloc(res, GFP_KERNEL); 800fee0f298SMiklos Szeredi if (!buf) 801fee0f298SMiklos Szeredi return -ENOMEM; 802fee0f298SMiklos Szeredi 803fee0f298SMiklos Szeredi res = vfs_getxattr(dentry, name, buf, res); 804fee0f298SMiklos Szeredi if (res < 0) 805fee0f298SMiklos Szeredi kfree(buf); 806de7a52c9SMiklos Szeredi else 807de7a52c9SMiklos Szeredi *value = buf; 808de7a52c9SMiklos Szeredi } 809fee0f298SMiklos Szeredi return res; 810fee0f298SMiklos Szeredi } 811fee0f298SMiklos Szeredi 8120c288874SVivek Goyal /* Copy up data of an inode which was copied up metadata only in the past. */ 8130c288874SVivek Goyal static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c) 8140c288874SVivek Goyal { 815c86243b0SVivek Goyal struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); 8164f93b426SVivek Goyal struct path upperpath, datapath; 8170c288874SVivek Goyal int err; 818993a0b2aSVivek Goyal char *capability = NULL; 8193f649ab7SKees Cook ssize_t cap_size; 8200c288874SVivek Goyal 8210c288874SVivek Goyal ovl_path_upper(c->dentry, &upperpath); 8220c288874SVivek Goyal if (WARN_ON(upperpath.dentry == NULL)) 8230c288874SVivek Goyal return -EIO; 8240c288874SVivek Goyal 8254f93b426SVivek Goyal ovl_path_lowerdata(c->dentry, &datapath); 8264f93b426SVivek Goyal if (WARN_ON(datapath.dentry == NULL)) 8274f93b426SVivek Goyal return -EIO; 8284f93b426SVivek Goyal 829993a0b2aSVivek Goyal if (c->stat.size) { 830993a0b2aSVivek Goyal err = cap_size = ovl_getxattr(upperpath.dentry, XATTR_NAME_CAPS, 831de7a52c9SMiklos Szeredi &capability); 832de7a52c9SMiklos Szeredi if (cap_size < 0) 833993a0b2aSVivek Goyal goto out; 834993a0b2aSVivek Goyal } 835993a0b2aSVivek Goyal 836c86243b0SVivek Goyal err = ovl_copy_up_data(ofs, &datapath, &upperpath, c->stat.size); 8370c288874SVivek Goyal if (err) 838993a0b2aSVivek Goyal goto out_free; 839993a0b2aSVivek Goyal 840993a0b2aSVivek Goyal /* 841993a0b2aSVivek Goyal * Writing to upper file will clear security.capability xattr. We 842993a0b2aSVivek Goyal * don't want that to happen for normal copy-up operation. 843993a0b2aSVivek Goyal */ 844993a0b2aSVivek Goyal if (capability) { 84571097047SMiklos Szeredi err = vfs_setxattr(upperpath.dentry, XATTR_NAME_CAPS, 846993a0b2aSVivek Goyal capability, cap_size, 0); 847993a0b2aSVivek Goyal if (err) 848993a0b2aSVivek Goyal goto out_free; 849993a0b2aSVivek Goyal } 850993a0b2aSVivek Goyal 8510c288874SVivek Goyal 852610afc0bSMiklos Szeredi err = ovl_do_removexattr(ofs, upperpath.dentry, OVL_XATTR_METACOPY); 8530c288874SVivek Goyal if (err) 854993a0b2aSVivek Goyal goto out_free; 8550c288874SVivek Goyal 8560c288874SVivek Goyal ovl_set_upperdata(d_inode(c->dentry)); 857993a0b2aSVivek Goyal out_free: 858993a0b2aSVivek Goyal kfree(capability); 859993a0b2aSVivek Goyal out: 8600c288874SVivek Goyal return err; 8610c288874SVivek Goyal } 8620c288874SVivek Goyal 863a6fb235aSMiklos Szeredi static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, 864a6fb235aSMiklos Szeredi int flags) 865a6fb235aSMiklos Szeredi { 866a6fb235aSMiklos Szeredi int err; 867a6fb235aSMiklos Szeredi DEFINE_DELAYED_CALL(done); 868a6fb235aSMiklos Szeredi struct path parentpath; 869a6fb235aSMiklos Szeredi struct ovl_copy_up_ctx ctx = { 870a6fb235aSMiklos Szeredi .parent = parent, 871a6fb235aSMiklos Szeredi .dentry = dentry, 872a6fb235aSMiklos Szeredi .workdir = ovl_workdir(dentry), 873a6fb235aSMiklos Szeredi }; 874a6fb235aSMiklos Szeredi 875a6fb235aSMiklos Szeredi if (WARN_ON(!ctx.workdir)) 876a6fb235aSMiklos Szeredi return -EROFS; 877a6fb235aSMiklos Szeredi 878a6fb235aSMiklos Szeredi ovl_path_lower(dentry, &ctx.lowerpath); 879a6fb235aSMiklos Szeredi err = vfs_getattr(&ctx.lowerpath, &ctx.stat, 880a6fb235aSMiklos Szeredi STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT); 881a6fb235aSMiklos Szeredi if (err) 882a6fb235aSMiklos Szeredi return err; 883a6fb235aSMiklos Szeredi 88444d5bf10SVivek Goyal ctx.metacopy = ovl_need_meta_copy_up(dentry, ctx.stat.mode, flags); 88544d5bf10SVivek Goyal 886aa3ff3c1SAmir Goldstein if (parent) { 887a6fb235aSMiklos Szeredi ovl_path_upper(parent, &parentpath); 88859be0971SAmir Goldstein ctx.destdir = parentpath.dentry; 88959be0971SAmir Goldstein ctx.destname = dentry->d_name; 890a6fb235aSMiklos Szeredi 891a6fb235aSMiklos Szeredi err = vfs_getattr(&parentpath, &ctx.pstat, 892aa3ff3c1SAmir Goldstein STATX_ATIME | STATX_MTIME, 893aa3ff3c1SAmir Goldstein AT_STATX_SYNC_AS_STAT); 894a6fb235aSMiklos Szeredi if (err) 895a6fb235aSMiklos Szeredi return err; 896aa3ff3c1SAmir Goldstein } 897a6fb235aSMiklos Szeredi 898a6fb235aSMiklos Szeredi /* maybe truncate regular file. this has no effect on dirs */ 899a6fb235aSMiklos Szeredi if (flags & O_TRUNC) 900a6fb235aSMiklos Szeredi ctx.stat.size = 0; 901a6fb235aSMiklos Szeredi 902a6fb235aSMiklos Szeredi if (S_ISLNK(ctx.stat.mode)) { 903a6fb235aSMiklos Szeredi ctx.link = vfs_get_link(ctx.lowerpath.dentry, &done); 904a6fb235aSMiklos Szeredi if (IS_ERR(ctx.link)) 905a6fb235aSMiklos Szeredi return PTR_ERR(ctx.link); 906a6fb235aSMiklos Szeredi } 907a6fb235aSMiklos Szeredi 9080c288874SVivek Goyal err = ovl_copy_up_start(dentry, flags); 909fd210b7dSMiklos Szeredi /* err < 0: interrupted, err > 0: raced with another copy-up */ 910fd210b7dSMiklos Szeredi if (unlikely(err)) { 911fd210b7dSMiklos Szeredi if (err > 0) 912fd210b7dSMiklos Szeredi err = 0; 913fd210b7dSMiklos Szeredi } else { 91459be0971SAmir Goldstein if (!ovl_dentry_upper(dentry)) 915a6fb235aSMiklos Szeredi err = ovl_do_copy_up(&ctx); 916aa3ff3c1SAmir Goldstein if (!err && parent && !ovl_dentry_has_upper_alias(dentry)) 917f4439de1SAmir Goldstein err = ovl_link_up(&ctx); 9180c288874SVivek Goyal if (!err && ovl_dentry_needs_data_copy_up_locked(dentry, flags)) 9190c288874SVivek Goyal err = ovl_copy_up_meta_inode_data(&ctx); 920fd210b7dSMiklos Szeredi ovl_copy_up_end(dentry); 921fd210b7dSMiklos Szeredi } 9227764235bSMiklos Szeredi do_delayed_call(&done); 923e9be9d5eSMiklos Szeredi 924e9be9d5eSMiklos Szeredi return err; 925e9be9d5eSMiklos Szeredi } 926e9be9d5eSMiklos Szeredi 9275ac8e802Syoungjun static int ovl_copy_up_flags(struct dentry *dentry, int flags) 928e9be9d5eSMiklos Szeredi { 9298eac98b8SVivek Goyal int err = 0; 9308eac98b8SVivek Goyal const struct cred *old_cred = ovl_override_creds(dentry->d_sb); 931aa3ff3c1SAmir Goldstein bool disconnected = (dentry->d_flags & DCACHE_DISCONNECTED); 932aa3ff3c1SAmir Goldstein 933aa3ff3c1SAmir Goldstein /* 934aa3ff3c1SAmir Goldstein * With NFS export, copy up can get called for a disconnected non-dir. 935aa3ff3c1SAmir Goldstein * In this case, we will copy up lower inode to index dir without 936aa3ff3c1SAmir Goldstein * linking it to upper dir. 937aa3ff3c1SAmir Goldstein */ 938aa3ff3c1SAmir Goldstein if (WARN_ON(disconnected && d_is_dir(dentry))) 939aa3ff3c1SAmir Goldstein return -EIO; 940e9be9d5eSMiklos Szeredi 941e9be9d5eSMiklos Szeredi while (!err) { 942e9be9d5eSMiklos Szeredi struct dentry *next; 943aa3ff3c1SAmir Goldstein struct dentry *parent = NULL; 944e9be9d5eSMiklos Szeredi 9450c288874SVivek Goyal if (ovl_already_copied_up(dentry, flags)) 946e9be9d5eSMiklos Szeredi break; 947e9be9d5eSMiklos Szeredi 948e9be9d5eSMiklos Szeredi next = dget(dentry); 949e9be9d5eSMiklos Szeredi /* find the topmost dentry not yet copied up */ 950aa3ff3c1SAmir Goldstein for (; !disconnected;) { 951e9be9d5eSMiklos Szeredi parent = dget_parent(next); 952e9be9d5eSMiklos Szeredi 95359be0971SAmir Goldstein if (ovl_dentry_upper(parent)) 954e9be9d5eSMiklos Szeredi break; 955e9be9d5eSMiklos Szeredi 956e9be9d5eSMiklos Szeredi dput(next); 957e9be9d5eSMiklos Szeredi next = parent; 958e9be9d5eSMiklos Szeredi } 959e9be9d5eSMiklos Szeredi 960a6fb235aSMiklos Szeredi err = ovl_copy_up_one(parent, next, flags); 961e9be9d5eSMiklos Szeredi 962e9be9d5eSMiklos Szeredi dput(parent); 963e9be9d5eSMiklos Szeredi dput(next); 964e9be9d5eSMiklos Szeredi } 9658eac98b8SVivek Goyal revert_creds(old_cred); 966e9be9d5eSMiklos Szeredi 967e9be9d5eSMiklos Szeredi return err; 968e9be9d5eSMiklos Szeredi } 9699aba6521SAmir Goldstein 970d6eac039SVivek Goyal static bool ovl_open_need_copy_up(struct dentry *dentry, int flags) 971d6eac039SVivek Goyal { 972d6eac039SVivek Goyal /* Copy up of disconnected dentry does not set upper alias */ 9730c288874SVivek Goyal if (ovl_already_copied_up(dentry, flags)) 974d6eac039SVivek Goyal return false; 975d6eac039SVivek Goyal 976d6eac039SVivek Goyal if (special_file(d_inode(dentry)->i_mode)) 977d6eac039SVivek Goyal return false; 978d6eac039SVivek Goyal 9790c288874SVivek Goyal if (!ovl_open_flags_need_copy_up(flags)) 980d6eac039SVivek Goyal return false; 981d6eac039SVivek Goyal 982d6eac039SVivek Goyal return true; 983d6eac039SVivek Goyal } 984d6eac039SVivek Goyal 9853428030dSAmir Goldstein int ovl_maybe_copy_up(struct dentry *dentry, int flags) 986d6eac039SVivek Goyal { 987d6eac039SVivek Goyal int err = 0; 988d6eac039SVivek Goyal 9893428030dSAmir Goldstein if (ovl_open_need_copy_up(dentry, flags)) { 990d6eac039SVivek Goyal err = ovl_want_write(dentry); 991d6eac039SVivek Goyal if (!err) { 9923428030dSAmir Goldstein err = ovl_copy_up_flags(dentry, flags); 993d6eac039SVivek Goyal ovl_drop_write(dentry); 994d6eac039SVivek Goyal } 995d6eac039SVivek Goyal } 996d6eac039SVivek Goyal 997d6eac039SVivek Goyal return err; 998d6eac039SVivek Goyal } 999d6eac039SVivek Goyal 1000d1e6f6a9SVivek Goyal int ovl_copy_up_with_data(struct dentry *dentry) 1001d1e6f6a9SVivek Goyal { 1002d1e6f6a9SVivek Goyal return ovl_copy_up_flags(dentry, O_WRONLY); 1003d1e6f6a9SVivek Goyal } 1004d1e6f6a9SVivek Goyal 10059aba6521SAmir Goldstein int ovl_copy_up(struct dentry *dentry) 10069aba6521SAmir Goldstein { 10079aba6521SAmir Goldstein return ovl_copy_up_flags(dentry, 0); 10089aba6521SAmir Goldstein } 1009