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> 1172db8211SAmir Goldstein #include <linux/fileattr.h> 12e9be9d5eSMiklos Szeredi #include <linux/splice.h> 13e9be9d5eSMiklos Szeredi #include <linux/xattr.h> 14e9be9d5eSMiklos Szeredi #include <linux/security.h> 15e9be9d5eSMiklos Szeredi #include <linux/uaccess.h> 16174cd4b1SIngo Molnar #include <linux/sched/signal.h> 175b825c3aSIngo Molnar #include <linux/cred.h> 18e9be9d5eSMiklos Szeredi #include <linux/namei.h> 19fb5bb2c3SDavid Howells #include <linux/fdtable.h> 20fb5bb2c3SDavid Howells #include <linux/ratelimit.h> 213a1e819bSAmir Goldstein #include <linux/exportfs.h> 22e9be9d5eSMiklos Szeredi #include "overlayfs.h" 23e9be9d5eSMiklos Szeredi 24e9be9d5eSMiklos Szeredi #define OVL_COPY_UP_CHUNK_SIZE (1 << 20) 25e9be9d5eSMiklos Szeredi 26670c2324SMiklos Szeredi static int ovl_ccup_set(const char *buf, const struct kernel_param *param) 27fb5bb2c3SDavid Howells { 281bd0a3aeSlijiazi pr_warn("\"check_copy_up\" module option is obsolete\n"); 29fb5bb2c3SDavid Howells return 0; 30fb5bb2c3SDavid Howells } 31fb5bb2c3SDavid Howells 32670c2324SMiklos Szeredi static int ovl_ccup_get(char *buf, const struct kernel_param *param) 33fb5bb2c3SDavid Howells { 34670c2324SMiklos Szeredi return sprintf(buf, "N\n"); 35fb5bb2c3SDavid Howells } 36fb5bb2c3SDavid Howells 37670c2324SMiklos Szeredi module_param_call(check_copy_up, ovl_ccup_set, ovl_ccup_get, NULL, 0644); 38253e7483SNicolas Schier MODULE_PARM_DESC(check_copy_up, "Obsolete; does nothing"); 39670c2324SMiklos Szeredi 40c61ca557SMiklos Szeredi static bool ovl_must_copy_xattr(const char *name) 41c61ca557SMiklos Szeredi { 42c61ca557SMiklos Szeredi return !strcmp(name, XATTR_POSIX_ACL_ACCESS) || 43c61ca557SMiklos Szeredi !strcmp(name, XATTR_POSIX_ACL_DEFAULT) || 44c61ca557SMiklos Szeredi !strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN); 45c61ca557SMiklos Szeredi } 46c61ca557SMiklos Szeredi 47610afc0bSMiklos Szeredi int ovl_copy_xattr(struct super_block *sb, struct dentry *old, 48610afc0bSMiklos Szeredi struct dentry *new) 49e9be9d5eSMiklos Szeredi { 50e4ad29faSVito Caputo ssize_t list_size, size, value_size = 0; 51e4ad29faSVito Caputo char *buf, *name, *value = NULL; 52520da69dSYuxuan Shui int error = 0; 538b326c61SMiklos Szeredi size_t slen; 54e9be9d5eSMiklos Szeredi 555d6c3191SAndreas Gruenbacher if (!(old->d_inode->i_opflags & IOP_XATTR) || 565d6c3191SAndreas Gruenbacher !(new->d_inode->i_opflags & IOP_XATTR)) 57e9be9d5eSMiklos Szeredi return 0; 58e9be9d5eSMiklos Szeredi 59e9be9d5eSMiklos Szeredi list_size = vfs_listxattr(old, NULL, 0); 60e9be9d5eSMiklos Szeredi if (list_size <= 0) { 61e9be9d5eSMiklos Szeredi if (list_size == -EOPNOTSUPP) 62e9be9d5eSMiklos Szeredi return 0; 63e9be9d5eSMiklos Szeredi return list_size; 64e9be9d5eSMiklos Szeredi } 65e9be9d5eSMiklos Szeredi 66*f945ca19SMiklos Szeredi buf = kvzalloc(list_size, GFP_KERNEL); 67e9be9d5eSMiklos Szeredi if (!buf) 68e9be9d5eSMiklos Szeredi return -ENOMEM; 69e9be9d5eSMiklos Szeredi 70e9be9d5eSMiklos Szeredi list_size = vfs_listxattr(old, buf, list_size); 71e9be9d5eSMiklos Szeredi if (list_size <= 0) { 72e9be9d5eSMiklos Szeredi error = list_size; 73e4ad29faSVito Caputo goto out; 74e9be9d5eSMiklos Szeredi } 75e9be9d5eSMiklos Szeredi 768b326c61SMiklos Szeredi for (name = buf; list_size; name += slen) { 778b326c61SMiklos Szeredi slen = strnlen(name, list_size) + 1; 788b326c61SMiklos Szeredi 798b326c61SMiklos Szeredi /* underlying fs providing us with an broken xattr list? */ 808b326c61SMiklos Szeredi if (WARN_ON(slen > list_size)) { 818b326c61SMiklos Szeredi error = -EIO; 828b326c61SMiklos Szeredi break; 838b326c61SMiklos Szeredi } 848b326c61SMiklos Szeredi list_size -= slen; 858b326c61SMiklos Szeredi 86610afc0bSMiklos Szeredi if (ovl_is_private_xattr(sb, name)) 870956254aSMiklos Szeredi continue; 8803fedf93SAmir Goldstein 8903fedf93SAmir Goldstein error = security_inode_copy_up_xattr(name); 9003fedf93SAmir Goldstein if (error < 0 && error != -EOPNOTSUPP) 9103fedf93SAmir Goldstein break; 9203fedf93SAmir Goldstein if (error == 1) { 9303fedf93SAmir Goldstein error = 0; 9403fedf93SAmir Goldstein continue; /* Discard */ 9503fedf93SAmir Goldstein } 96e4ad29faSVito Caputo retry: 97c7c7a1a1STycho Andersen size = vfs_getxattr(&init_user_ns, old, name, value, value_size); 98e4ad29faSVito Caputo if (size == -ERANGE) 99c7c7a1a1STycho Andersen size = vfs_getxattr(&init_user_ns, old, name, NULL, 0); 100e4ad29faSVito Caputo 10197daf8b9SMiklos Szeredi if (size < 0) { 102e9be9d5eSMiklos Szeredi error = size; 103e4ad29faSVito Caputo break; 104e9be9d5eSMiklos Szeredi } 105e9be9d5eSMiklos Szeredi 106e4ad29faSVito Caputo if (size > value_size) { 107e4ad29faSVito Caputo void *new; 108e4ad29faSVito Caputo 109*f945ca19SMiklos Szeredi new = kvmalloc(size, GFP_KERNEL); 110e4ad29faSVito Caputo if (!new) { 111e4ad29faSVito Caputo error = -ENOMEM; 112e4ad29faSVito Caputo break; 113e4ad29faSVito Caputo } 114*f945ca19SMiklos Szeredi kvfree(value); 115e4ad29faSVito Caputo value = new; 116e4ad29faSVito Caputo value_size = size; 117e4ad29faSVito Caputo goto retry; 118e4ad29faSVito Caputo } 119e4ad29faSVito Caputo 120c7c7a1a1STycho Andersen error = vfs_setxattr(&init_user_ns, new, name, value, size, 0); 121c61ca557SMiklos Szeredi if (error) { 122c61ca557SMiklos Szeredi if (error != -EOPNOTSUPP || ovl_must_copy_xattr(name)) 123e4ad29faSVito Caputo break; 124c61ca557SMiklos Szeredi 125c61ca557SMiklos Szeredi /* Ignore failure to copy unknown xattrs */ 126c61ca557SMiklos Szeredi error = 0; 127c61ca557SMiklos Szeredi } 128e4ad29faSVito Caputo } 129*f945ca19SMiklos Szeredi kvfree(value); 130e9be9d5eSMiklos Szeredi out: 131*f945ca19SMiklos Szeredi kvfree(buf); 132e9be9d5eSMiklos Szeredi return error; 133e9be9d5eSMiklos Szeredi } 134e9be9d5eSMiklos Szeredi 135096a218aSAmir Goldstein static int ovl_copy_fileattr(struct inode *inode, struct path *old, 136096a218aSAmir Goldstein struct path *new) 13772db8211SAmir Goldstein { 13872db8211SAmir Goldstein struct fileattr oldfa = { .flags_valid = true }; 13972db8211SAmir Goldstein struct fileattr newfa = { .flags_valid = true }; 14072db8211SAmir Goldstein int err; 14172db8211SAmir Goldstein 14272db8211SAmir Goldstein err = ovl_real_fileattr_get(old, &oldfa); 14372db8211SAmir Goldstein if (err) 14472db8211SAmir Goldstein return err; 14572db8211SAmir Goldstein 14672db8211SAmir Goldstein err = ovl_real_fileattr_get(new, &newfa); 14772db8211SAmir Goldstein if (err) 14872db8211SAmir Goldstein return err; 14972db8211SAmir Goldstein 150096a218aSAmir Goldstein /* 151096a218aSAmir Goldstein * We cannot set immutable and append-only flags on upper inode, 152096a218aSAmir Goldstein * because we would not be able to link upper inode to upper dir 153096a218aSAmir Goldstein * not set overlay private xattr on upper inode. 154096a218aSAmir Goldstein * Store these flags in overlay.protattr xattr instead. 155096a218aSAmir Goldstein */ 156096a218aSAmir Goldstein if (oldfa.flags & OVL_PROT_FS_FLAGS_MASK) { 157096a218aSAmir Goldstein err = ovl_set_protattr(inode, new->dentry, &oldfa); 158096a218aSAmir Goldstein if (err) 159096a218aSAmir Goldstein return err; 160096a218aSAmir Goldstein } 161096a218aSAmir Goldstein 16272db8211SAmir Goldstein BUILD_BUG_ON(OVL_COPY_FS_FLAGS_MASK & ~FS_COMMON_FL); 16372db8211SAmir Goldstein newfa.flags &= ~OVL_COPY_FS_FLAGS_MASK; 16472db8211SAmir Goldstein newfa.flags |= (oldfa.flags & OVL_COPY_FS_FLAGS_MASK); 16572db8211SAmir Goldstein 16672db8211SAmir Goldstein BUILD_BUG_ON(OVL_COPY_FSX_FLAGS_MASK & ~FS_XFLAG_COMMON); 16772db8211SAmir Goldstein newfa.fsx_xflags &= ~OVL_COPY_FSX_FLAGS_MASK; 16872db8211SAmir Goldstein newfa.fsx_xflags |= (oldfa.fsx_xflags & OVL_COPY_FSX_FLAGS_MASK); 16972db8211SAmir Goldstein 17072db8211SAmir Goldstein return ovl_real_fileattr_set(new, &newfa); 17172db8211SAmir Goldstein } 17272db8211SAmir Goldstein 173c86243b0SVivek Goyal static int ovl_copy_up_data(struct ovl_fs *ofs, struct path *old, 174c86243b0SVivek Goyal struct path *new, loff_t len) 175e9be9d5eSMiklos Szeredi { 176e9be9d5eSMiklos Szeredi struct file *old_file; 177e9be9d5eSMiklos Szeredi struct file *new_file; 178e9be9d5eSMiklos Szeredi loff_t old_pos = 0; 179e9be9d5eSMiklos Szeredi loff_t new_pos = 0; 18042ec3d4cSDarrick J. Wong loff_t cloned; 181b504c654SChengguang Xu loff_t data_pos = -1; 182b504c654SChengguang Xu loff_t hole_len; 183b504c654SChengguang Xu bool skip_hole = false; 184e9be9d5eSMiklos Szeredi int error = 0; 185e9be9d5eSMiklos Szeredi 186e9be9d5eSMiklos Szeredi if (len == 0) 187e9be9d5eSMiklos Szeredi return 0; 188e9be9d5eSMiklos Szeredi 1890480334fSDavid Howells old_file = ovl_path_open(old, O_LARGEFILE | O_RDONLY); 190e9be9d5eSMiklos Szeredi if (IS_ERR(old_file)) 191e9be9d5eSMiklos Szeredi return PTR_ERR(old_file); 192e9be9d5eSMiklos Szeredi 1930480334fSDavid Howells new_file = ovl_path_open(new, O_LARGEFILE | O_WRONLY); 194e9be9d5eSMiklos Szeredi if (IS_ERR(new_file)) { 195e9be9d5eSMiklos Szeredi error = PTR_ERR(new_file); 196e9be9d5eSMiklos Szeredi goto out_fput; 197e9be9d5eSMiklos Szeredi } 198e9be9d5eSMiklos Szeredi 1992ea98466SAmir Goldstein /* Try to use clone_file_range to clone up within the same fs */ 200452ce659SDarrick J. Wong cloned = do_clone_file_range(old_file, 0, new_file, 0, len, 0); 20142ec3d4cSDarrick J. Wong if (cloned == len) 2022ea98466SAmir Goldstein goto out; 2032ea98466SAmir Goldstein /* Couldn't clone, so now we try to copy the data */ 2042ea98466SAmir Goldstein 205b504c654SChengguang Xu /* Check if lower fs supports seek operation */ 206b504c654SChengguang Xu if (old_file->f_mode & FMODE_LSEEK && 207b504c654SChengguang Xu old_file->f_op->llseek) 208b504c654SChengguang Xu skip_hole = true; 209b504c654SChengguang Xu 210e9be9d5eSMiklos Szeredi while (len) { 211e9be9d5eSMiklos Szeredi size_t this_len = OVL_COPY_UP_CHUNK_SIZE; 212e9be9d5eSMiklos Szeredi long bytes; 213e9be9d5eSMiklos Szeredi 214e9be9d5eSMiklos Szeredi if (len < this_len) 215e9be9d5eSMiklos Szeredi this_len = len; 216e9be9d5eSMiklos Szeredi 217e9be9d5eSMiklos Szeredi if (signal_pending_state(TASK_KILLABLE, current)) { 218e9be9d5eSMiklos Szeredi error = -EINTR; 219e9be9d5eSMiklos Szeredi break; 220e9be9d5eSMiklos Szeredi } 221e9be9d5eSMiklos Szeredi 222b504c654SChengguang Xu /* 223b504c654SChengguang Xu * Fill zero for hole will cost unnecessary disk space 224b504c654SChengguang Xu * and meanwhile slow down the copy-up speed, so we do 225b504c654SChengguang Xu * an optimization for hole during copy-up, it relies 226b504c654SChengguang Xu * on SEEK_DATA implementation in lower fs so if lower 227b504c654SChengguang Xu * fs does not support it, copy-up will behave as before. 228b504c654SChengguang Xu * 229b504c654SChengguang Xu * Detail logic of hole detection as below: 230b504c654SChengguang Xu * When we detect next data position is larger than current 231b504c654SChengguang Xu * position we will skip that hole, otherwise we copy 232b504c654SChengguang Xu * data in the size of OVL_COPY_UP_CHUNK_SIZE. Actually, 233b504c654SChengguang Xu * it may not recognize all kind of holes and sometimes 234b504c654SChengguang Xu * only skips partial of hole area. However, it will be 235b504c654SChengguang Xu * enough for most of the use cases. 236b504c654SChengguang Xu */ 237b504c654SChengguang Xu 238b504c654SChengguang Xu if (skip_hole && data_pos < old_pos) { 239b504c654SChengguang Xu data_pos = vfs_llseek(old_file, old_pos, SEEK_DATA); 240b504c654SChengguang Xu if (data_pos > old_pos) { 241b504c654SChengguang Xu hole_len = data_pos - old_pos; 242b504c654SChengguang Xu len -= hole_len; 243b504c654SChengguang Xu old_pos = new_pos = data_pos; 244b504c654SChengguang Xu continue; 245b504c654SChengguang Xu } else if (data_pos == -ENXIO) { 246b504c654SChengguang Xu break; 247b504c654SChengguang Xu } else if (data_pos < 0) { 248b504c654SChengguang Xu skip_hole = false; 249b504c654SChengguang Xu } 250b504c654SChengguang Xu } 251b504c654SChengguang Xu 252e9be9d5eSMiklos Szeredi bytes = do_splice_direct(old_file, &old_pos, 253e9be9d5eSMiklos Szeredi new_file, &new_pos, 254e9be9d5eSMiklos Szeredi this_len, SPLICE_F_MOVE); 255e9be9d5eSMiklos Szeredi if (bytes <= 0) { 256e9be9d5eSMiklos Szeredi error = bytes; 257e9be9d5eSMiklos Szeredi break; 258e9be9d5eSMiklos Szeredi } 259e9be9d5eSMiklos Szeredi WARN_ON(old_pos != new_pos); 260e9be9d5eSMiklos Szeredi 261e9be9d5eSMiklos Szeredi len -= bytes; 262e9be9d5eSMiklos Szeredi } 2632ea98466SAmir Goldstein out: 264c86243b0SVivek Goyal if (!error && ovl_should_sync(ofs)) 265641089c1SMiklos Szeredi error = vfs_fsync(new_file, 0); 266e9be9d5eSMiklos Szeredi fput(new_file); 267e9be9d5eSMiklos Szeredi out_fput: 268e9be9d5eSMiklos Szeredi fput(old_file); 269e9be9d5eSMiklos Szeredi return error; 270e9be9d5eSMiklos Szeredi } 271e9be9d5eSMiklos Szeredi 2720c288874SVivek Goyal static int ovl_set_size(struct dentry *upperdentry, struct kstat *stat) 2730c288874SVivek Goyal { 2740c288874SVivek Goyal struct iattr attr = { 2750c288874SVivek Goyal .ia_valid = ATTR_SIZE, 2760c288874SVivek Goyal .ia_size = stat->size, 2770c288874SVivek Goyal }; 2780c288874SVivek Goyal 2792f221d6fSChristian Brauner return notify_change(&init_user_ns, upperdentry, &attr, NULL); 2800c288874SVivek Goyal } 2810c288874SVivek Goyal 282e9be9d5eSMiklos Szeredi static int ovl_set_timestamps(struct dentry *upperdentry, struct kstat *stat) 283e9be9d5eSMiklos Szeredi { 284e9be9d5eSMiklos Szeredi struct iattr attr = { 285e9be9d5eSMiklos Szeredi .ia_valid = 286e9be9d5eSMiklos Szeredi ATTR_ATIME | ATTR_MTIME | ATTR_ATIME_SET | ATTR_MTIME_SET, 287e9be9d5eSMiklos Szeredi .ia_atime = stat->atime, 288e9be9d5eSMiklos Szeredi .ia_mtime = stat->mtime, 289e9be9d5eSMiklos Szeredi }; 290e9be9d5eSMiklos Szeredi 2912f221d6fSChristian Brauner return notify_change(&init_user_ns, upperdentry, &attr, NULL); 292e9be9d5eSMiklos Szeredi } 293e9be9d5eSMiklos Szeredi 294e9be9d5eSMiklos Szeredi int ovl_set_attr(struct dentry *upperdentry, struct kstat *stat) 295e9be9d5eSMiklos Szeredi { 296e9be9d5eSMiklos Szeredi int err = 0; 297e9be9d5eSMiklos Szeredi 298e9be9d5eSMiklos Szeredi if (!S_ISLNK(stat->mode)) { 299e9be9d5eSMiklos Szeredi struct iattr attr = { 300e9be9d5eSMiklos Szeredi .ia_valid = ATTR_MODE, 301e9be9d5eSMiklos Szeredi .ia_mode = stat->mode, 302e9be9d5eSMiklos Szeredi }; 3032f221d6fSChristian Brauner err = notify_change(&init_user_ns, upperdentry, &attr, NULL); 304e9be9d5eSMiklos Szeredi } 305e9be9d5eSMiklos Szeredi if (!err) { 306e9be9d5eSMiklos Szeredi struct iattr attr = { 307e9be9d5eSMiklos Szeredi .ia_valid = ATTR_UID | ATTR_GID, 308e9be9d5eSMiklos Szeredi .ia_uid = stat->uid, 309e9be9d5eSMiklos Szeredi .ia_gid = stat->gid, 310e9be9d5eSMiklos Szeredi }; 3112f221d6fSChristian Brauner err = notify_change(&init_user_ns, upperdentry, &attr, NULL); 312e9be9d5eSMiklos Szeredi } 313e9be9d5eSMiklos Szeredi if (!err) 314e9be9d5eSMiklos Szeredi ovl_set_timestamps(upperdentry, stat); 315e9be9d5eSMiklos Szeredi 316e9be9d5eSMiklos Szeredi return err; 317e9be9d5eSMiklos Szeredi } 318e9be9d5eSMiklos Szeredi 3191cdb0cb6SPavel Tikhomirov struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real, 3201cdb0cb6SPavel Tikhomirov bool is_upper) 3213a1e819bSAmir Goldstein { 3223a1e819bSAmir Goldstein struct ovl_fh *fh; 323ec7bbb53SAmir Goldstein int fh_type, dwords; 3243a1e819bSAmir Goldstein int buflen = MAX_HANDLE_SZ; 32505122443SAmir Goldstein uuid_t *uuid = &real->d_sb->s_uuid; 326ec7bbb53SAmir Goldstein int err; 3273a1e819bSAmir Goldstein 328ec7bbb53SAmir Goldstein /* Make sure the real fid stays 32bit aligned */ 329ec7bbb53SAmir Goldstein BUILD_BUG_ON(OVL_FH_FID_OFFSET % 4); 330ec7bbb53SAmir Goldstein BUILD_BUG_ON(MAX_HANDLE_SZ + OVL_FH_FID_OFFSET > 255); 331ec7bbb53SAmir Goldstein 332ec7bbb53SAmir Goldstein fh = kzalloc(buflen + OVL_FH_FID_OFFSET, GFP_KERNEL); 333ec7bbb53SAmir Goldstein if (!fh) 3343a1e819bSAmir Goldstein return ERR_PTR(-ENOMEM); 3353a1e819bSAmir Goldstein 3363a1e819bSAmir Goldstein /* 3373a1e819bSAmir Goldstein * We encode a non-connectable file handle for non-dir, because we 3383a1e819bSAmir Goldstein * only need to find the lower inode number and we don't want to pay 3393a1e819bSAmir Goldstein * the price or reconnecting the dentry. 3403a1e819bSAmir Goldstein */ 3413a1e819bSAmir Goldstein dwords = buflen >> 2; 342ec7bbb53SAmir Goldstein fh_type = exportfs_encode_fh(real, (void *)fh->fb.fid, &dwords, 0); 3433a1e819bSAmir Goldstein buflen = (dwords << 2); 3443a1e819bSAmir Goldstein 345ec7bbb53SAmir Goldstein err = -EIO; 3463a1e819bSAmir Goldstein if (WARN_ON(fh_type < 0) || 3473a1e819bSAmir Goldstein WARN_ON(buflen > MAX_HANDLE_SZ) || 3483a1e819bSAmir Goldstein WARN_ON(fh_type == FILEID_INVALID)) 349ec7bbb53SAmir Goldstein goto out_err; 3503a1e819bSAmir Goldstein 351cbe7fba8SAmir Goldstein fh->fb.version = OVL_FH_VERSION; 352cbe7fba8SAmir Goldstein fh->fb.magic = OVL_FH_MAGIC; 353cbe7fba8SAmir Goldstein fh->fb.type = fh_type; 354cbe7fba8SAmir Goldstein fh->fb.flags = OVL_FH_FLAG_CPU_ENDIAN; 35554fb347eSAmir Goldstein /* 35654fb347eSAmir Goldstein * When we will want to decode an overlay dentry from this handle 35754fb347eSAmir Goldstein * and all layers are on the same fs, if we get a disconncted real 35854fb347eSAmir Goldstein * dentry when we decode fid, the only way to tell if we should assign 35954fb347eSAmir Goldstein * it to upperdentry or to lowerstack is by checking this flag. 36054fb347eSAmir Goldstein */ 36154fb347eSAmir Goldstein if (is_upper) 362cbe7fba8SAmir Goldstein fh->fb.flags |= OVL_FH_FLAG_PATH_UPPER; 363ec7bbb53SAmir Goldstein fh->fb.len = sizeof(fh->fb) + buflen; 3645830fb6bSPavel Tikhomirov if (ofs->config.uuid) 365cbe7fba8SAmir Goldstein fh->fb.uuid = *uuid; 3663a1e819bSAmir Goldstein 3673a1e819bSAmir Goldstein return fh; 368ec7bbb53SAmir Goldstein 369ec7bbb53SAmir Goldstein out_err: 370ec7bbb53SAmir Goldstein kfree(fh); 371ec7bbb53SAmir Goldstein return ERR_PTR(err); 3723a1e819bSAmir Goldstein } 3733a1e819bSAmir Goldstein 374a0c236b1SAmir Goldstein int ovl_set_origin(struct ovl_fs *ofs, struct dentry *lower, 375a0c236b1SAmir Goldstein struct dentry *upper) 3763a1e819bSAmir Goldstein { 3773a1e819bSAmir Goldstein const struct ovl_fh *fh = NULL; 3783a1e819bSAmir Goldstein int err; 3793a1e819bSAmir Goldstein 3803a1e819bSAmir Goldstein /* 3813a1e819bSAmir Goldstein * When lower layer doesn't support export operations store a 'null' fh, 3823a1e819bSAmir Goldstein * so we can use the overlay.origin xattr to distignuish between a copy 3833a1e819bSAmir Goldstein * up and a pure upper inode. 3843a1e819bSAmir Goldstein */ 38502bcd157SAmir Goldstein if (ovl_can_decode_fh(lower->d_sb)) { 3861cdb0cb6SPavel Tikhomirov fh = ovl_encode_real_fh(ofs, lower, false); 3873a1e819bSAmir Goldstein if (IS_ERR(fh)) 3883a1e819bSAmir Goldstein return PTR_ERR(fh); 3893a1e819bSAmir Goldstein } 3903a1e819bSAmir Goldstein 3916266d465SMiklos Szeredi /* 3926266d465SMiklos Szeredi * Do not fail when upper doesn't support xattrs. 3936266d465SMiklos Szeredi */ 394a0c236b1SAmir Goldstein err = ovl_check_setxattr(ofs, upper, OVL_XATTR_ORIGIN, fh->buf, 395cbe7fba8SAmir Goldstein fh ? fh->fb.len : 0, 0); 3963a1e819bSAmir Goldstein kfree(fh); 3973a1e819bSAmir Goldstein 3986939f977SMiklos Szeredi /* Ignore -EPERM from setting "user.*" on symlink/special */ 3996939f977SMiklos Szeredi return err == -EPERM ? 0 : err; 4003a1e819bSAmir Goldstein } 4013a1e819bSAmir Goldstein 402016b720fSAmir Goldstein /* Store file handle of @upper dir in @index dir entry */ 403610afc0bSMiklos Szeredi static int ovl_set_upper_fh(struct ovl_fs *ofs, struct dentry *upper, 404610afc0bSMiklos Szeredi struct dentry *index) 405016b720fSAmir Goldstein { 406016b720fSAmir Goldstein const struct ovl_fh *fh; 407016b720fSAmir Goldstein int err; 408016b720fSAmir Goldstein 4091cdb0cb6SPavel Tikhomirov fh = ovl_encode_real_fh(ofs, upper, true); 410016b720fSAmir Goldstein if (IS_ERR(fh)) 411016b720fSAmir Goldstein return PTR_ERR(fh); 412016b720fSAmir Goldstein 413610afc0bSMiklos Szeredi err = ovl_do_setxattr(ofs, index, OVL_XATTR_UPPER, fh->buf, fh->fb.len); 414016b720fSAmir Goldstein 415016b720fSAmir Goldstein kfree(fh); 416016b720fSAmir Goldstein return err; 417016b720fSAmir Goldstein } 418016b720fSAmir Goldstein 419016b720fSAmir Goldstein /* 420016b720fSAmir Goldstein * Create and install index entry. 421016b720fSAmir Goldstein * 422016b720fSAmir Goldstein * Caller must hold i_mutex on indexdir. 423016b720fSAmir Goldstein */ 424016b720fSAmir Goldstein static int ovl_create_index(struct dentry *dentry, struct dentry *origin, 425016b720fSAmir Goldstein struct dentry *upper) 426016b720fSAmir Goldstein { 4271cdb0cb6SPavel Tikhomirov struct ovl_fs *ofs = OVL_FS(dentry->d_sb); 428016b720fSAmir Goldstein struct dentry *indexdir = ovl_indexdir(dentry->d_sb); 429016b720fSAmir Goldstein struct inode *dir = d_inode(indexdir); 430016b720fSAmir Goldstein struct dentry *index = NULL; 431016b720fSAmir Goldstein struct dentry *temp = NULL; 432016b720fSAmir Goldstein struct qstr name = { }; 433016b720fSAmir Goldstein int err; 434016b720fSAmir Goldstein 435016b720fSAmir Goldstein /* 436016b720fSAmir Goldstein * For now this is only used for creating index entry for directories, 437016b720fSAmir Goldstein * because non-dir are copied up directly to index and then hardlinked 438016b720fSAmir Goldstein * to upper dir. 439016b720fSAmir Goldstein * 440016b720fSAmir Goldstein * TODO: implement create index for non-dir, so we can call it when 441016b720fSAmir Goldstein * encoding file handle for non-dir in case index does not exist. 442016b720fSAmir Goldstein */ 443016b720fSAmir Goldstein if (WARN_ON(!d_is_dir(dentry))) 444016b720fSAmir Goldstein return -EIO; 445016b720fSAmir Goldstein 446016b720fSAmir Goldstein /* Directory not expected to be indexed before copy up */ 447016b720fSAmir Goldstein if (WARN_ON(ovl_test_flag(OVL_INDEX, d_inode(dentry)))) 448016b720fSAmir Goldstein return -EIO; 449016b720fSAmir Goldstein 4501cdb0cb6SPavel Tikhomirov err = ovl_get_index_name(ofs, origin, &name); 451016b720fSAmir Goldstein if (err) 452016b720fSAmir Goldstein return err; 453016b720fSAmir Goldstein 454137ec526SAmir Goldstein temp = ovl_create_temp(indexdir, OVL_CATTR(S_IFDIR | 0)); 455b148cba4SMiklos Szeredi err = PTR_ERR(temp); 456016b720fSAmir Goldstein if (IS_ERR(temp)) 457b148cba4SMiklos Szeredi goto free_name; 458016b720fSAmir Goldstein 4591cdb0cb6SPavel Tikhomirov err = ovl_set_upper_fh(ofs, upper, temp); 460016b720fSAmir Goldstein if (err) 461b148cba4SMiklos Szeredi goto out; 462016b720fSAmir Goldstein 463016b720fSAmir Goldstein index = lookup_one_len(name.name, indexdir, name.len); 464016b720fSAmir Goldstein if (IS_ERR(index)) { 465016b720fSAmir Goldstein err = PTR_ERR(index); 466016b720fSAmir Goldstein } else { 467016b720fSAmir Goldstein err = ovl_do_rename(dir, temp, dir, index, 0); 468016b720fSAmir Goldstein dput(index); 469016b720fSAmir Goldstein } 470016b720fSAmir Goldstein out: 471b148cba4SMiklos Szeredi if (err) 472b148cba4SMiklos Szeredi ovl_cleanup(dir, temp); 473016b720fSAmir Goldstein dput(temp); 474b148cba4SMiklos Szeredi free_name: 475016b720fSAmir Goldstein kfree(name.name); 476016b720fSAmir Goldstein return err; 477016b720fSAmir Goldstein } 478016b720fSAmir Goldstein 47923f0ab13SMiklos Szeredi struct ovl_copy_up_ctx { 480a6fb235aSMiklos Szeredi struct dentry *parent; 48123f0ab13SMiklos Szeredi struct dentry *dentry; 48223f0ab13SMiklos Szeredi struct path lowerpath; 48323f0ab13SMiklos Szeredi struct kstat stat; 48423f0ab13SMiklos Szeredi struct kstat pstat; 48523f0ab13SMiklos Szeredi const char *link; 48659be0971SAmir Goldstein struct dentry *destdir; 48759be0971SAmir Goldstein struct qstr destname; 48823f0ab13SMiklos Szeredi struct dentry *workdir; 48959be0971SAmir Goldstein bool origin; 490016b720fSAmir Goldstein bool indexed; 49144d5bf10SVivek Goyal bool metacopy; 49223f0ab13SMiklos Szeredi }; 49323f0ab13SMiklos Szeredi 494f4439de1SAmir Goldstein static int ovl_link_up(struct ovl_copy_up_ctx *c) 495f4439de1SAmir Goldstein { 496f4439de1SAmir Goldstein int err; 497f4439de1SAmir Goldstein struct dentry *upper; 498f4439de1SAmir Goldstein struct dentry *upperdir = ovl_dentry_upper(c->parent); 499f4439de1SAmir Goldstein struct inode *udir = d_inode(upperdir); 500f4439de1SAmir Goldstein 501f4439de1SAmir Goldstein /* Mark parent "impure" because it may now contain non-pure upper */ 502f4439de1SAmir Goldstein err = ovl_set_impure(c->parent, upperdir); 503f4439de1SAmir Goldstein if (err) 504f4439de1SAmir Goldstein return err; 505f4439de1SAmir Goldstein 506f4439de1SAmir Goldstein err = ovl_set_nlink_lower(c->dentry); 507f4439de1SAmir Goldstein if (err) 508f4439de1SAmir Goldstein return err; 509f4439de1SAmir Goldstein 510f4439de1SAmir Goldstein inode_lock_nested(udir, I_MUTEX_PARENT); 511f4439de1SAmir Goldstein upper = lookup_one_len(c->dentry->d_name.name, upperdir, 512f4439de1SAmir Goldstein c->dentry->d_name.len); 513f4439de1SAmir Goldstein err = PTR_ERR(upper); 514f4439de1SAmir Goldstein if (!IS_ERR(upper)) { 5156cf00764SAmir Goldstein err = ovl_do_link(ovl_dentry_upper(c->dentry), udir, upper); 516f4439de1SAmir Goldstein dput(upper); 517f4439de1SAmir Goldstein 518f4439de1SAmir Goldstein if (!err) { 519f4439de1SAmir Goldstein /* Restore timestamps on parent (best effort) */ 520f4439de1SAmir Goldstein ovl_set_timestamps(upperdir, &c->pstat); 521f4439de1SAmir Goldstein ovl_dentry_set_upper_alias(c->dentry); 522f4439de1SAmir Goldstein } 523f4439de1SAmir Goldstein } 524f4439de1SAmir Goldstein inode_unlock(udir); 525aa3ff3c1SAmir Goldstein if (err) 526aa3ff3c1SAmir Goldstein return err; 527aa3ff3c1SAmir Goldstein 528aa3ff3c1SAmir Goldstein err = ovl_set_nlink_upper(c->dentry); 529f4439de1SAmir Goldstein 530f4439de1SAmir Goldstein return err; 531f4439de1SAmir Goldstein } 532f4439de1SAmir Goldstein 53323f0ab13SMiklos Szeredi static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp) 53402209d10SAmir Goldstein { 535c86243b0SVivek Goyal struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); 53672db8211SAmir Goldstein struct inode *inode = d_inode(c->dentry); 53772db8211SAmir Goldstein struct path upperpath, datapath; 53802209d10SAmir Goldstein int err; 53902209d10SAmir Goldstein 54072db8211SAmir Goldstein ovl_path_upper(c->dentry, &upperpath); 54172db8211SAmir Goldstein if (WARN_ON(upperpath.dentry != NULL)) 54272db8211SAmir Goldstein return -EIO; 54372db8211SAmir Goldstein 54472db8211SAmir Goldstein upperpath.dentry = temp; 54572db8211SAmir Goldstein 5465f32879eSVivek Goyal /* 5475f32879eSVivek Goyal * Copy up data first and then xattrs. Writing data after 5485f32879eSVivek Goyal * xattrs will remove security.capability xattr automatically. 5495f32879eSVivek Goyal */ 5505f32879eSVivek Goyal if (S_ISREG(c->stat.mode) && !c->metacopy) { 5515f32879eSVivek Goyal ovl_path_lowerdata(c->dentry, &datapath); 552c86243b0SVivek Goyal err = ovl_copy_up_data(ofs, &datapath, &upperpath, 553c86243b0SVivek Goyal c->stat.size); 5545f32879eSVivek Goyal if (err) 5555f32879eSVivek Goyal return err; 5565f32879eSVivek Goyal } 5575f32879eSVivek Goyal 558610afc0bSMiklos Szeredi err = ovl_copy_xattr(c->dentry->d_sb, c->lowerpath.dentry, temp); 55902209d10SAmir Goldstein if (err) 56002209d10SAmir Goldstein return err; 56102209d10SAmir Goldstein 56272db8211SAmir Goldstein if (inode->i_flags & OVL_COPY_I_FLAGS_MASK) { 56372db8211SAmir Goldstein /* 56472db8211SAmir Goldstein * Copy the fileattr inode flags that are the source of already 56572db8211SAmir Goldstein * copied i_flags 56672db8211SAmir Goldstein */ 567096a218aSAmir Goldstein err = ovl_copy_fileattr(inode, &c->lowerpath, &upperpath); 56872db8211SAmir Goldstein if (err) 56972db8211SAmir Goldstein return err; 57072db8211SAmir Goldstein } 57172db8211SAmir Goldstein 57202209d10SAmir Goldstein /* 57302209d10SAmir Goldstein * Store identifier of lower inode in upper inode xattr to 57402209d10SAmir Goldstein * allow lookup of the copy up origin inode. 57502209d10SAmir Goldstein * 57602209d10SAmir Goldstein * Don't set origin when we are breaking the association with a lower 57702209d10SAmir Goldstein * hard link. 57802209d10SAmir Goldstein */ 57959be0971SAmir Goldstein if (c->origin) { 580a0c236b1SAmir Goldstein err = ovl_set_origin(ofs, c->lowerpath.dentry, temp); 58102209d10SAmir Goldstein if (err) 58202209d10SAmir Goldstein return err; 58302209d10SAmir Goldstein } 58402209d10SAmir Goldstein 5850c288874SVivek Goyal if (c->metacopy) { 586a0c236b1SAmir Goldstein err = ovl_check_setxattr(ofs, temp, OVL_XATTR_METACOPY, 5870c288874SVivek Goyal NULL, 0, -EOPNOTSUPP); 5880c288874SVivek Goyal if (err) 5890c288874SVivek Goyal return err; 5900c288874SVivek Goyal } 5910c288874SVivek Goyal 592bd64e575SVivek Goyal inode_lock(temp->d_inode); 593b504c654SChengguang Xu if (S_ISREG(c->stat.mode)) 5940c288874SVivek Goyal err = ovl_set_size(temp, &c->stat); 5950c288874SVivek Goyal if (!err) 596bd64e575SVivek Goyal err = ovl_set_attr(temp, &c->stat); 597bd64e575SVivek Goyal inode_unlock(temp->d_inode); 598bd64e575SVivek Goyal 599bd64e575SVivek Goyal return err; 60002209d10SAmir Goldstein } 60102209d10SAmir Goldstein 6026b52243fSMiklos Szeredi struct ovl_cu_creds { 6036b52243fSMiklos Szeredi const struct cred *old; 6046b52243fSMiklos Szeredi struct cred *new; 605b10cdcdcSAmir Goldstein }; 606b10cdcdcSAmir Goldstein 6076b52243fSMiklos Szeredi static int ovl_prep_cu_creds(struct dentry *dentry, struct ovl_cu_creds *cc) 608b10cdcdcSAmir Goldstein { 609b10cdcdcSAmir Goldstein int err; 610b10cdcdcSAmir Goldstein 6116b52243fSMiklos Szeredi cc->old = cc->new = NULL; 6126b52243fSMiklos Szeredi err = security_inode_copy_up(dentry, &cc->new); 6136b52243fSMiklos Szeredi if (err < 0) 614b10cdcdcSAmir Goldstein return err; 6156b52243fSMiklos Szeredi 6166b52243fSMiklos Szeredi if (cc->new) 6176b52243fSMiklos Szeredi cc->old = override_creds(cc->new); 6186b52243fSMiklos Szeredi 6196b52243fSMiklos Szeredi return 0; 6206b52243fSMiklos Szeredi } 6216b52243fSMiklos Szeredi 6226b52243fSMiklos Szeredi static void ovl_revert_cu_creds(struct ovl_cu_creds *cc) 6236b52243fSMiklos Szeredi { 6246b52243fSMiklos Szeredi if (cc->new) { 6256b52243fSMiklos Szeredi revert_creds(cc->old); 6266b52243fSMiklos Szeredi put_cred(cc->new); 6276b52243fSMiklos Szeredi } 628b10cdcdcSAmir Goldstein } 629b10cdcdcSAmir Goldstein 630b10cdcdcSAmir Goldstein /* 631b10cdcdcSAmir Goldstein * Copyup using workdir to prepare temp file. Used when copying up directories, 632b10cdcdcSAmir Goldstein * special files or when upper fs doesn't support O_TMPFILE. 633b10cdcdcSAmir Goldstein */ 634b10cdcdcSAmir Goldstein static int ovl_copy_up_workdir(struct ovl_copy_up_ctx *c) 635b10cdcdcSAmir Goldstein { 636b79e05aaSAmir Goldstein struct inode *inode; 6376b52243fSMiklos Szeredi struct inode *udir = d_inode(c->destdir), *wdir = d_inode(c->workdir); 6386b52243fSMiklos Szeredi struct dentry *temp, *upper; 6396b52243fSMiklos Szeredi struct ovl_cu_creds cc; 6407d90b853SMiklos Szeredi int err; 6416b52243fSMiklos Szeredi struct ovl_cattr cattr = { 6426b52243fSMiklos Szeredi /* Can't properly set mode on creation because of the umask */ 6436b52243fSMiklos Szeredi .mode = c->stat.mode & S_IFMT, 6446b52243fSMiklos Szeredi .rdev = c->stat.rdev, 6456b52243fSMiklos Szeredi .link = c->link 6466b52243fSMiklos Szeredi }; 6477d90b853SMiklos Szeredi 648773cb4c5SAmir Goldstein /* workdir and destdir could be the same when copying up to indexdir */ 649773cb4c5SAmir Goldstein err = -EIO; 650773cb4c5SAmir Goldstein if (lock_rename(c->workdir, c->destdir) != NULL) 651773cb4c5SAmir Goldstein goto unlock; 652b10cdcdcSAmir Goldstein 6536b52243fSMiklos Szeredi err = ovl_prep_cu_creds(c->dentry, &cc); 6546b52243fSMiklos Szeredi if (err) 6556b52243fSMiklos Szeredi goto unlock; 6566b52243fSMiklos Szeredi 6576b52243fSMiklos Szeredi temp = ovl_create_temp(c->workdir, &cattr); 6586b52243fSMiklos Szeredi ovl_revert_cu_creds(&cc); 6596b52243fSMiklos Szeredi 660b10cdcdcSAmir Goldstein err = PTR_ERR(temp); 661b10cdcdcSAmir Goldstein if (IS_ERR(temp)) 662b10cdcdcSAmir Goldstein goto unlock; 663b10cdcdcSAmir Goldstein 664b10cdcdcSAmir Goldstein err = ovl_copy_up_inode(c, temp); 665b10cdcdcSAmir Goldstein if (err) 666b10cdcdcSAmir Goldstein goto cleanup; 667b10cdcdcSAmir Goldstein 668b10cdcdcSAmir Goldstein if (S_ISDIR(c->stat.mode) && c->indexed) { 669b10cdcdcSAmir Goldstein err = ovl_create_index(c->dentry, c->lowerpath.dentry, temp); 670b10cdcdcSAmir Goldstein if (err) 671b10cdcdcSAmir Goldstein goto cleanup; 672b10cdcdcSAmir Goldstein } 673b10cdcdcSAmir Goldstein 6746b52243fSMiklos Szeredi upper = lookup_one_len(c->destname.name, c->destdir, c->destname.len); 6756b52243fSMiklos Szeredi err = PTR_ERR(upper); 6766b52243fSMiklos Szeredi if (IS_ERR(upper)) 6776b52243fSMiklos Szeredi goto cleanup; 6786b52243fSMiklos Szeredi 6796b52243fSMiklos Szeredi err = ovl_do_rename(wdir, temp, udir, upper, 0); 6806b52243fSMiklos Szeredi dput(upper); 681b10cdcdcSAmir Goldstein if (err) 682b10cdcdcSAmir Goldstein goto cleanup; 683b10cdcdcSAmir Goldstein 684b10cdcdcSAmir Goldstein if (!c->metacopy) 685b10cdcdcSAmir Goldstein ovl_set_upperdata(d_inode(c->dentry)); 686b10cdcdcSAmir Goldstein inode = d_inode(c->dentry); 6876b52243fSMiklos Szeredi ovl_inode_update(inode, temp); 688b10cdcdcSAmir Goldstein if (S_ISDIR(inode->i_mode)) 689b10cdcdcSAmir Goldstein ovl_set_flag(OVL_WHITEOUTS, inode); 690b10cdcdcSAmir Goldstein unlock: 691b10cdcdcSAmir Goldstein unlock_rename(c->workdir, c->destdir); 692b10cdcdcSAmir Goldstein 693b10cdcdcSAmir Goldstein return err; 694b10cdcdcSAmir Goldstein 695b10cdcdcSAmir Goldstein cleanup: 6966b52243fSMiklos Szeredi ovl_cleanup(wdir, temp); 6976b52243fSMiklos Szeredi dput(temp); 698b10cdcdcSAmir Goldstein goto unlock; 699b10cdcdcSAmir Goldstein } 700b10cdcdcSAmir Goldstein 701b10cdcdcSAmir Goldstein /* Copyup using O_TMPFILE which does not require cross dir locking */ 702b10cdcdcSAmir Goldstein static int ovl_copy_up_tmpfile(struct ovl_copy_up_ctx *c) 703b10cdcdcSAmir Goldstein { 7046b52243fSMiklos Szeredi struct inode *udir = d_inode(c->destdir); 7056b52243fSMiklos Szeredi struct dentry *temp, *upper; 7066b52243fSMiklos Szeredi struct ovl_cu_creds cc; 707b10cdcdcSAmir Goldstein int err; 708b10cdcdcSAmir Goldstein 7096b52243fSMiklos Szeredi err = ovl_prep_cu_creds(c->dentry, &cc); 7106b52243fSMiklos Szeredi if (err) 7116b52243fSMiklos Szeredi return err; 7126b52243fSMiklos Szeredi 7136b52243fSMiklos Szeredi temp = ovl_do_tmpfile(c->workdir, c->stat.mode); 7146b52243fSMiklos Szeredi ovl_revert_cu_creds(&cc); 7156b52243fSMiklos Szeredi 716b148cba4SMiklos Szeredi if (IS_ERR(temp)) 717b148cba4SMiklos Szeredi return PTR_ERR(temp); 718e9be9d5eSMiklos Szeredi 71923f0ab13SMiklos Szeredi err = ovl_copy_up_inode(c, temp); 720e9be9d5eSMiklos Szeredi if (err) 7216b52243fSMiklos Szeredi goto out_dput; 7223a1e819bSAmir Goldstein 7236b52243fSMiklos Szeredi inode_lock_nested(udir, I_MUTEX_PARENT); 7246b52243fSMiklos Szeredi 7256b52243fSMiklos Szeredi upper = lookup_one_len(c->destname.name, c->destdir, c->destname.len); 7266b52243fSMiklos Szeredi err = PTR_ERR(upper); 7276b52243fSMiklos Szeredi if (!IS_ERR(upper)) { 7286b52243fSMiklos Szeredi err = ovl_do_link(temp, udir, upper); 7296b52243fSMiklos Szeredi dput(upper); 7306b52243fSMiklos Szeredi } 7316b52243fSMiklos Szeredi inode_unlock(udir); 7326b52243fSMiklos Szeredi 733e9be9d5eSMiklos Szeredi if (err) 7346b52243fSMiklos Szeredi goto out_dput; 735e9be9d5eSMiklos Szeredi 7360c288874SVivek Goyal if (!c->metacopy) 7370c288874SVivek Goyal ovl_set_upperdata(d_inode(c->dentry)); 7386b52243fSMiklos Szeredi ovl_inode_update(d_inode(c->dentry), temp); 739b79e05aaSAmir Goldstein 7406b52243fSMiklos Szeredi return 0; 7416b52243fSMiklos Szeredi 7426b52243fSMiklos Szeredi out_dput: 743e85f82ffSMiklos Szeredi dput(temp); 744e9be9d5eSMiklos Szeredi return err; 745e9be9d5eSMiklos Szeredi } 746e9be9d5eSMiklos Szeredi 747e9be9d5eSMiklos Szeredi /* 748e9be9d5eSMiklos Szeredi * Copy up a single dentry 749e9be9d5eSMiklos Szeredi * 750a6c60655SMiklos Szeredi * All renames start with copy up of source if necessary. The actual 751a6c60655SMiklos Szeredi * rename will only proceed once the copy up was successful. Copy up uses 752a6c60655SMiklos Szeredi * upper parent i_mutex for exclusion. Since rename can change d_parent it 753a6c60655SMiklos Szeredi * is possible that the copy up will lock the old parent. At that point 754a6c60655SMiklos Szeredi * the file will have already been copied up anyway. 755e9be9d5eSMiklos Szeredi */ 756a6fb235aSMiklos Szeredi static int ovl_do_copy_up(struct ovl_copy_up_ctx *c) 757e9be9d5eSMiklos Szeredi { 758e9be9d5eSMiklos Szeredi int err; 7591cdb0cb6SPavel Tikhomirov struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); 760016b720fSAmir Goldstein bool to_index = false; 76159be0971SAmir Goldstein 762016b720fSAmir Goldstein /* 763016b720fSAmir Goldstein * Indexed non-dir is copied up directly to the index entry and then 764016b720fSAmir Goldstein * hardlinked to upper dir. Indexed dir is copied up to indexdir, 765016b720fSAmir Goldstein * then index entry is created and then copied up dir installed. 766016b720fSAmir Goldstein * Copying dir up to indexdir instead of workdir simplifies locking. 767016b720fSAmir Goldstein */ 768016b720fSAmir Goldstein if (ovl_need_index(c->dentry)) { 769016b720fSAmir Goldstein c->indexed = true; 770016b720fSAmir Goldstein if (S_ISDIR(c->stat.mode)) 771016b720fSAmir Goldstein c->workdir = ovl_indexdir(c->dentry->d_sb); 772016b720fSAmir Goldstein else 773016b720fSAmir Goldstein to_index = true; 774016b720fSAmir Goldstein } 775016b720fSAmir Goldstein 776016b720fSAmir Goldstein if (S_ISDIR(c->stat.mode) || c->stat.nlink == 1 || to_index) 77759be0971SAmir Goldstein c->origin = true; 77859be0971SAmir Goldstein 779016b720fSAmir Goldstein if (to_index) { 78059be0971SAmir Goldstein c->destdir = ovl_indexdir(c->dentry->d_sb); 7811cdb0cb6SPavel Tikhomirov err = ovl_get_index_name(ofs, c->lowerpath.dentry, &c->destname); 782f3a15685SAmir Goldstein if (err) 783f3a15685SAmir Goldstein return err; 784aa3ff3c1SAmir Goldstein } else if (WARN_ON(!c->parent)) { 785aa3ff3c1SAmir Goldstein /* Disconnected dentry must be copied up to index dir */ 786aa3ff3c1SAmir Goldstein return -EIO; 78759be0971SAmir Goldstein } else { 78859be0971SAmir Goldstein /* 78959be0971SAmir Goldstein * Mark parent "impure" because it may now contain non-pure 79059be0971SAmir Goldstein * upper 79159be0971SAmir Goldstein */ 79259be0971SAmir Goldstein err = ovl_set_impure(c->parent, c->destdir); 79359be0971SAmir Goldstein if (err) 79459be0971SAmir Goldstein return err; 79559be0971SAmir Goldstein } 796f3a15685SAmir Goldstein 79701ad3eb8SAmir Goldstein /* Should we copyup with O_TMPFILE or with workdir? */ 798b10cdcdcSAmir Goldstein if (S_ISREG(c->stat.mode) && ofs->tmpfile) 799b10cdcdcSAmir Goldstein err = ovl_copy_up_tmpfile(c); 800b10cdcdcSAmir Goldstein else 801b10cdcdcSAmir Goldstein err = ovl_copy_up_workdir(c); 802aa3ff3c1SAmir Goldstein if (err) 803aa3ff3c1SAmir Goldstein goto out; 804aa3ff3c1SAmir Goldstein 805aa3ff3c1SAmir Goldstein if (c->indexed) 80659be0971SAmir Goldstein ovl_set_flag(OVL_INDEX, d_inode(c->dentry)); 807016b720fSAmir Goldstein 808016b720fSAmir Goldstein if (to_index) { 809aa3ff3c1SAmir Goldstein /* Initialize nlink for copy up of disconnected dentry */ 810aa3ff3c1SAmir Goldstein err = ovl_set_nlink_upper(c->dentry); 811aa3ff3c1SAmir Goldstein } else { 81259be0971SAmir Goldstein struct inode *udir = d_inode(c->destdir); 81359be0971SAmir Goldstein 81459be0971SAmir Goldstein /* Restore timestamps on parent (best effort) */ 81559be0971SAmir Goldstein inode_lock(udir); 81659be0971SAmir Goldstein ovl_set_timestamps(c->destdir, &c->pstat); 81759be0971SAmir Goldstein inode_unlock(udir); 81859be0971SAmir Goldstein 81959be0971SAmir Goldstein ovl_dentry_set_upper_alias(c->dentry); 820fd210b7dSMiklos Szeredi } 821a6fb235aSMiklos Szeredi 822aa3ff3c1SAmir Goldstein out: 823aa3ff3c1SAmir Goldstein if (to_index) 824aa3ff3c1SAmir Goldstein kfree(c->destname.name); 825a6fb235aSMiklos Szeredi return err; 826a6fb235aSMiklos Szeredi } 827a6fb235aSMiklos Szeredi 82844d5bf10SVivek Goyal static bool ovl_need_meta_copy_up(struct dentry *dentry, umode_t mode, 82944d5bf10SVivek Goyal int flags) 83044d5bf10SVivek Goyal { 83144d5bf10SVivek Goyal struct ovl_fs *ofs = dentry->d_sb->s_fs_info; 83244d5bf10SVivek Goyal 83344d5bf10SVivek Goyal if (!ofs->config.metacopy) 83444d5bf10SVivek Goyal return false; 83544d5bf10SVivek Goyal 83644d5bf10SVivek Goyal if (!S_ISREG(mode)) 83744d5bf10SVivek Goyal return false; 83844d5bf10SVivek Goyal 83944d5bf10SVivek Goyal if (flags && ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC))) 84044d5bf10SVivek Goyal return false; 84144d5bf10SVivek Goyal 84244d5bf10SVivek Goyal return true; 84344d5bf10SVivek Goyal } 84444d5bf10SVivek Goyal 845de7a52c9SMiklos Szeredi static ssize_t ovl_getxattr(struct dentry *dentry, char *name, char **value) 846fee0f298SMiklos Szeredi { 847fee0f298SMiklos Szeredi ssize_t res; 848de7a52c9SMiklos Szeredi char *buf; 849fee0f298SMiklos Szeredi 850c7c7a1a1STycho Andersen res = vfs_getxattr(&init_user_ns, dentry, name, NULL, 0); 851fee0f298SMiklos Szeredi if (res == -ENODATA || res == -EOPNOTSUPP) 852de7a52c9SMiklos Szeredi res = 0; 853fee0f298SMiklos Szeredi 854de7a52c9SMiklos Szeredi if (res > 0) { 855de7a52c9SMiklos Szeredi buf = kzalloc(res, GFP_KERNEL); 856fee0f298SMiklos Szeredi if (!buf) 857fee0f298SMiklos Szeredi return -ENOMEM; 858fee0f298SMiklos Szeredi 859c7c7a1a1STycho Andersen res = vfs_getxattr(&init_user_ns, dentry, name, buf, res); 860fee0f298SMiklos Szeredi if (res < 0) 861fee0f298SMiklos Szeredi kfree(buf); 862de7a52c9SMiklos Szeredi else 863de7a52c9SMiklos Szeredi *value = buf; 864de7a52c9SMiklos Szeredi } 865fee0f298SMiklos Szeredi return res; 866fee0f298SMiklos Szeredi } 867fee0f298SMiklos Szeredi 8680c288874SVivek Goyal /* Copy up data of an inode which was copied up metadata only in the past. */ 8690c288874SVivek Goyal static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c) 8700c288874SVivek Goyal { 871c86243b0SVivek Goyal struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); 8724f93b426SVivek Goyal struct path upperpath, datapath; 8730c288874SVivek Goyal int err; 874993a0b2aSVivek Goyal char *capability = NULL; 8753f649ab7SKees Cook ssize_t cap_size; 8760c288874SVivek Goyal 8770c288874SVivek Goyal ovl_path_upper(c->dentry, &upperpath); 8780c288874SVivek Goyal if (WARN_ON(upperpath.dentry == NULL)) 8790c288874SVivek Goyal return -EIO; 8800c288874SVivek Goyal 8814f93b426SVivek Goyal ovl_path_lowerdata(c->dentry, &datapath); 8824f93b426SVivek Goyal if (WARN_ON(datapath.dentry == NULL)) 8834f93b426SVivek Goyal return -EIO; 8844f93b426SVivek Goyal 885993a0b2aSVivek Goyal if (c->stat.size) { 886993a0b2aSVivek Goyal err = cap_size = ovl_getxattr(upperpath.dentry, XATTR_NAME_CAPS, 887de7a52c9SMiklos Szeredi &capability); 888de7a52c9SMiklos Szeredi if (cap_size < 0) 889993a0b2aSVivek Goyal goto out; 890993a0b2aSVivek Goyal } 891993a0b2aSVivek Goyal 892c86243b0SVivek Goyal err = ovl_copy_up_data(ofs, &datapath, &upperpath, c->stat.size); 8930c288874SVivek Goyal if (err) 894993a0b2aSVivek Goyal goto out_free; 895993a0b2aSVivek Goyal 896993a0b2aSVivek Goyal /* 897993a0b2aSVivek Goyal * Writing to upper file will clear security.capability xattr. We 898993a0b2aSVivek Goyal * don't want that to happen for normal copy-up operation. 899993a0b2aSVivek Goyal */ 900993a0b2aSVivek Goyal if (capability) { 901c7c7a1a1STycho Andersen err = vfs_setxattr(&init_user_ns, upperpath.dentry, 902c7c7a1a1STycho Andersen XATTR_NAME_CAPS, capability, cap_size, 0); 903993a0b2aSVivek Goyal if (err) 904993a0b2aSVivek Goyal goto out_free; 905993a0b2aSVivek Goyal } 906993a0b2aSVivek Goyal 9070c288874SVivek Goyal 908610afc0bSMiklos Szeredi err = ovl_do_removexattr(ofs, upperpath.dentry, OVL_XATTR_METACOPY); 9090c288874SVivek Goyal if (err) 910993a0b2aSVivek Goyal goto out_free; 9110c288874SVivek Goyal 9120c288874SVivek Goyal ovl_set_upperdata(d_inode(c->dentry)); 913993a0b2aSVivek Goyal out_free: 914993a0b2aSVivek Goyal kfree(capability); 915993a0b2aSVivek Goyal out: 9160c288874SVivek Goyal return err; 9170c288874SVivek Goyal } 9180c288874SVivek Goyal 919a6fb235aSMiklos Szeredi static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, 920a6fb235aSMiklos Szeredi int flags) 921a6fb235aSMiklos Szeredi { 922a6fb235aSMiklos Szeredi int err; 923a6fb235aSMiklos Szeredi DEFINE_DELAYED_CALL(done); 924a6fb235aSMiklos Szeredi struct path parentpath; 925a6fb235aSMiklos Szeredi struct ovl_copy_up_ctx ctx = { 926a6fb235aSMiklos Szeredi .parent = parent, 927a6fb235aSMiklos Szeredi .dentry = dentry, 928a6fb235aSMiklos Szeredi .workdir = ovl_workdir(dentry), 929a6fb235aSMiklos Szeredi }; 930a6fb235aSMiklos Szeredi 931a6fb235aSMiklos Szeredi if (WARN_ON(!ctx.workdir)) 932a6fb235aSMiklos Szeredi return -EROFS; 933a6fb235aSMiklos Szeredi 934a6fb235aSMiklos Szeredi ovl_path_lower(dentry, &ctx.lowerpath); 935a6fb235aSMiklos Szeredi err = vfs_getattr(&ctx.lowerpath, &ctx.stat, 936a6fb235aSMiklos Szeredi STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT); 937a6fb235aSMiklos Szeredi if (err) 938a6fb235aSMiklos Szeredi return err; 939a6fb235aSMiklos Szeredi 94044d5bf10SVivek Goyal ctx.metacopy = ovl_need_meta_copy_up(dentry, ctx.stat.mode, flags); 94144d5bf10SVivek Goyal 942aa3ff3c1SAmir Goldstein if (parent) { 943a6fb235aSMiklos Szeredi ovl_path_upper(parent, &parentpath); 94459be0971SAmir Goldstein ctx.destdir = parentpath.dentry; 94559be0971SAmir Goldstein ctx.destname = dentry->d_name; 946a6fb235aSMiklos Szeredi 947a6fb235aSMiklos Szeredi err = vfs_getattr(&parentpath, &ctx.pstat, 948aa3ff3c1SAmir Goldstein STATX_ATIME | STATX_MTIME, 949aa3ff3c1SAmir Goldstein AT_STATX_SYNC_AS_STAT); 950a6fb235aSMiklos Szeredi if (err) 951a6fb235aSMiklos Szeredi return err; 952aa3ff3c1SAmir Goldstein } 953a6fb235aSMiklos Szeredi 954a6fb235aSMiklos Szeredi /* maybe truncate regular file. this has no effect on dirs */ 955a6fb235aSMiklos Szeredi if (flags & O_TRUNC) 956a6fb235aSMiklos Szeredi ctx.stat.size = 0; 957a6fb235aSMiklos Szeredi 958a6fb235aSMiklos Szeredi if (S_ISLNK(ctx.stat.mode)) { 959a6fb235aSMiklos Szeredi ctx.link = vfs_get_link(ctx.lowerpath.dentry, &done); 960a6fb235aSMiklos Szeredi if (IS_ERR(ctx.link)) 961a6fb235aSMiklos Szeredi return PTR_ERR(ctx.link); 962a6fb235aSMiklos Szeredi } 963a6fb235aSMiklos Szeredi 9640c288874SVivek Goyal err = ovl_copy_up_start(dentry, flags); 965fd210b7dSMiklos Szeredi /* err < 0: interrupted, err > 0: raced with another copy-up */ 966fd210b7dSMiklos Szeredi if (unlikely(err)) { 967fd210b7dSMiklos Szeredi if (err > 0) 968fd210b7dSMiklos Szeredi err = 0; 969fd210b7dSMiklos Szeredi } else { 97059be0971SAmir Goldstein if (!ovl_dentry_upper(dentry)) 971a6fb235aSMiklos Szeredi err = ovl_do_copy_up(&ctx); 972aa3ff3c1SAmir Goldstein if (!err && parent && !ovl_dentry_has_upper_alias(dentry)) 973f4439de1SAmir Goldstein err = ovl_link_up(&ctx); 9740c288874SVivek Goyal if (!err && ovl_dentry_needs_data_copy_up_locked(dentry, flags)) 9750c288874SVivek Goyal err = ovl_copy_up_meta_inode_data(&ctx); 976fd210b7dSMiklos Szeredi ovl_copy_up_end(dentry); 977fd210b7dSMiklos Szeredi } 9787764235bSMiklos Szeredi do_delayed_call(&done); 979e9be9d5eSMiklos Szeredi 980e9be9d5eSMiklos Szeredi return err; 981e9be9d5eSMiklos Szeredi } 982e9be9d5eSMiklos Szeredi 9835ac8e802Syoungjun static int ovl_copy_up_flags(struct dentry *dentry, int flags) 984e9be9d5eSMiklos Szeredi { 9858eac98b8SVivek Goyal int err = 0; 9867b279bbfSDan Carpenter const struct cred *old_cred; 987aa3ff3c1SAmir Goldstein bool disconnected = (dentry->d_flags & DCACHE_DISCONNECTED); 988aa3ff3c1SAmir Goldstein 989aa3ff3c1SAmir Goldstein /* 990aa3ff3c1SAmir Goldstein * With NFS export, copy up can get called for a disconnected non-dir. 991aa3ff3c1SAmir Goldstein * In this case, we will copy up lower inode to index dir without 992aa3ff3c1SAmir Goldstein * linking it to upper dir. 993aa3ff3c1SAmir Goldstein */ 994aa3ff3c1SAmir Goldstein if (WARN_ON(disconnected && d_is_dir(dentry))) 995aa3ff3c1SAmir Goldstein return -EIO; 996e9be9d5eSMiklos Szeredi 9977b279bbfSDan Carpenter old_cred = ovl_override_creds(dentry->d_sb); 998e9be9d5eSMiklos Szeredi while (!err) { 999e9be9d5eSMiklos Szeredi struct dentry *next; 1000aa3ff3c1SAmir Goldstein struct dentry *parent = NULL; 1001e9be9d5eSMiklos Szeredi 10020c288874SVivek Goyal if (ovl_already_copied_up(dentry, flags)) 1003e9be9d5eSMiklos Szeredi break; 1004e9be9d5eSMiklos Szeredi 1005e9be9d5eSMiklos Szeredi next = dget(dentry); 1006e9be9d5eSMiklos Szeredi /* find the topmost dentry not yet copied up */ 1007aa3ff3c1SAmir Goldstein for (; !disconnected;) { 1008e9be9d5eSMiklos Szeredi parent = dget_parent(next); 1009e9be9d5eSMiklos Szeredi 101059be0971SAmir Goldstein if (ovl_dentry_upper(parent)) 1011e9be9d5eSMiklos Szeredi break; 1012e9be9d5eSMiklos Szeredi 1013e9be9d5eSMiklos Szeredi dput(next); 1014e9be9d5eSMiklos Szeredi next = parent; 1015e9be9d5eSMiklos Szeredi } 1016e9be9d5eSMiklos Szeredi 1017a6fb235aSMiklos Szeredi err = ovl_copy_up_one(parent, next, flags); 1018e9be9d5eSMiklos Szeredi 1019e9be9d5eSMiklos Szeredi dput(parent); 1020e9be9d5eSMiklos Szeredi dput(next); 1021e9be9d5eSMiklos Szeredi } 10228eac98b8SVivek Goyal revert_creds(old_cred); 1023e9be9d5eSMiklos Szeredi 1024e9be9d5eSMiklos Szeredi return err; 1025e9be9d5eSMiklos Szeredi } 10269aba6521SAmir Goldstein 1027d6eac039SVivek Goyal static bool ovl_open_need_copy_up(struct dentry *dentry, int flags) 1028d6eac039SVivek Goyal { 1029d6eac039SVivek Goyal /* Copy up of disconnected dentry does not set upper alias */ 10300c288874SVivek Goyal if (ovl_already_copied_up(dentry, flags)) 1031d6eac039SVivek Goyal return false; 1032d6eac039SVivek Goyal 1033d6eac039SVivek Goyal if (special_file(d_inode(dentry)->i_mode)) 1034d6eac039SVivek Goyal return false; 1035d6eac039SVivek Goyal 10360c288874SVivek Goyal if (!ovl_open_flags_need_copy_up(flags)) 1037d6eac039SVivek Goyal return false; 1038d6eac039SVivek Goyal 1039d6eac039SVivek Goyal return true; 1040d6eac039SVivek Goyal } 1041d6eac039SVivek Goyal 10423428030dSAmir Goldstein int ovl_maybe_copy_up(struct dentry *dentry, int flags) 1043d6eac039SVivek Goyal { 1044d6eac039SVivek Goyal int err = 0; 1045d6eac039SVivek Goyal 10463428030dSAmir Goldstein if (ovl_open_need_copy_up(dentry, flags)) { 1047d6eac039SVivek Goyal err = ovl_want_write(dentry); 1048d6eac039SVivek Goyal if (!err) { 10493428030dSAmir Goldstein err = ovl_copy_up_flags(dentry, flags); 1050d6eac039SVivek Goyal ovl_drop_write(dentry); 1051d6eac039SVivek Goyal } 1052d6eac039SVivek Goyal } 1053d6eac039SVivek Goyal 1054d6eac039SVivek Goyal return err; 1055d6eac039SVivek Goyal } 1056d6eac039SVivek Goyal 1057d1e6f6a9SVivek Goyal int ovl_copy_up_with_data(struct dentry *dentry) 1058d1e6f6a9SVivek Goyal { 1059d1e6f6a9SVivek Goyal return ovl_copy_up_flags(dentry, O_WRONLY); 1060d1e6f6a9SVivek Goyal } 1061d1e6f6a9SVivek Goyal 10629aba6521SAmir Goldstein int ovl_copy_up(struct dentry *dentry) 10639aba6521SAmir Goldstein { 10649aba6521SAmir Goldstein return ovl_copy_up_flags(dentry, 0); 10659aba6521SAmir Goldstein } 1066