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struct kernel_param *param) 27fb5bb2c3SDavid Howells { 281bd0a3aeSlijiazi pr_warn("\"check_copy_up\" module option is obsolete\n"); 29fb5bb2c3SDavid Howells return 0; 30fb5bb2c3SDavid Howells } 31fb5bb2c3SDavid Howells 32670c2324SMiklos Szeredi static int ovl_ccup_get(char *buf, const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 66f945ca19SMiklos 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 109f945ca19SMiklos Szeredi new = kvmalloc(size, GFP_KERNEL); 110e4ad29faSVito Caputo if (!new) { 111e4ad29faSVito Caputo error = -ENOMEM; 112e4ad29faSVito Caputo break; 113e4ad29faSVito Caputo } 114f945ca19SMiklos 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 } 129f945ca19SMiklos Szeredi kvfree(value); 130e9be9d5eSMiklos Szeredi out: 131f945ca19SMiklos 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); 143*5b0a414dSMiklos Szeredi if (err) { 144*5b0a414dSMiklos Szeredi /* Ntfs-3g returns -EINVAL for "no fileattr support" */ 145*5b0a414dSMiklos Szeredi if (err == -ENOTTY || err == -EINVAL) 146*5b0a414dSMiklos Szeredi return 0; 147*5b0a414dSMiklos Szeredi pr_warn("failed to retrieve lower fileattr (%pd2, err=%i)\n", 148*5b0a414dSMiklos Szeredi old, err); 14972db8211SAmir Goldstein return err; 150*5b0a414dSMiklos Szeredi } 15172db8211SAmir Goldstein 152096a218aSAmir Goldstein /* 153096a218aSAmir Goldstein * We cannot set immutable and append-only flags on upper inode, 154096a218aSAmir Goldstein * because we would not be able to link upper inode to upper dir 155096a218aSAmir Goldstein * not set overlay private xattr on upper inode. 156096a218aSAmir Goldstein * Store these flags in overlay.protattr xattr instead. 157096a218aSAmir Goldstein */ 158096a218aSAmir Goldstein if (oldfa.flags & OVL_PROT_FS_FLAGS_MASK) { 159096a218aSAmir Goldstein err = ovl_set_protattr(inode, new->dentry, &oldfa); 160096a218aSAmir Goldstein if (err) 161096a218aSAmir Goldstein return err; 162096a218aSAmir Goldstein } 163096a218aSAmir Goldstein 164*5b0a414dSMiklos Szeredi /* Don't bother copying flags if none are set */ 165*5b0a414dSMiklos Szeredi if (!(oldfa.flags & OVL_COPY_FS_FLAGS_MASK)) 166*5b0a414dSMiklos Szeredi return 0; 167*5b0a414dSMiklos Szeredi 168*5b0a414dSMiklos Szeredi err = ovl_real_fileattr_get(new, &newfa); 169*5b0a414dSMiklos Szeredi if (err) { 170*5b0a414dSMiklos Szeredi pr_warn("failed to retrieve upper fileattr (%pd2, err=%i)\n", 171*5b0a414dSMiklos Szeredi new, err); 172*5b0a414dSMiklos Szeredi return err; 173*5b0a414dSMiklos Szeredi } 174*5b0a414dSMiklos Szeredi 17572db8211SAmir Goldstein BUILD_BUG_ON(OVL_COPY_FS_FLAGS_MASK & ~FS_COMMON_FL); 17672db8211SAmir Goldstein newfa.flags &= ~OVL_COPY_FS_FLAGS_MASK; 17772db8211SAmir Goldstein newfa.flags |= (oldfa.flags & OVL_COPY_FS_FLAGS_MASK); 17872db8211SAmir Goldstein 17972db8211SAmir Goldstein BUILD_BUG_ON(OVL_COPY_FSX_FLAGS_MASK & ~FS_XFLAG_COMMON); 18072db8211SAmir Goldstein newfa.fsx_xflags &= ~OVL_COPY_FSX_FLAGS_MASK; 18172db8211SAmir Goldstein newfa.fsx_xflags |= (oldfa.fsx_xflags & OVL_COPY_FSX_FLAGS_MASK); 18272db8211SAmir Goldstein 18372db8211SAmir Goldstein return ovl_real_fileattr_set(new, &newfa); 18472db8211SAmir Goldstein } 18572db8211SAmir Goldstein 186c86243b0SVivek Goyal static int ovl_copy_up_data(struct ovl_fs *ofs, struct path *old, 187c86243b0SVivek Goyal struct path *new, loff_t len) 188e9be9d5eSMiklos Szeredi { 189e9be9d5eSMiklos Szeredi struct file *old_file; 190e9be9d5eSMiklos Szeredi struct file *new_file; 191e9be9d5eSMiklos Szeredi loff_t old_pos = 0; 192e9be9d5eSMiklos Szeredi loff_t new_pos = 0; 19342ec3d4cSDarrick J. Wong loff_t cloned; 194b504c654SChengguang Xu loff_t data_pos = -1; 195b504c654SChengguang Xu loff_t hole_len; 196b504c654SChengguang Xu bool skip_hole = false; 197e9be9d5eSMiklos Szeredi int error = 0; 198e9be9d5eSMiklos Szeredi 199e9be9d5eSMiklos Szeredi if (len == 0) 200e9be9d5eSMiklos Szeredi return 0; 201e9be9d5eSMiklos Szeredi 2020480334fSDavid Howells old_file = ovl_path_open(old, O_LARGEFILE | O_RDONLY); 203e9be9d5eSMiklos Szeredi if (IS_ERR(old_file)) 204e9be9d5eSMiklos Szeredi return PTR_ERR(old_file); 205e9be9d5eSMiklos Szeredi 2060480334fSDavid Howells new_file = ovl_path_open(new, O_LARGEFILE | O_WRONLY); 207e9be9d5eSMiklos Szeredi if (IS_ERR(new_file)) { 208e9be9d5eSMiklos Szeredi error = PTR_ERR(new_file); 209e9be9d5eSMiklos Szeredi goto out_fput; 210e9be9d5eSMiklos Szeredi } 211e9be9d5eSMiklos Szeredi 2122ea98466SAmir Goldstein /* Try to use clone_file_range to clone up within the same fs */ 213452ce659SDarrick J. Wong cloned = do_clone_file_range(old_file, 0, new_file, 0, len, 0); 21442ec3d4cSDarrick J. Wong if (cloned == len) 2152ea98466SAmir Goldstein goto out; 2162ea98466SAmir Goldstein /* Couldn't clone, so now we try to copy the data */ 2172ea98466SAmir Goldstein 218b504c654SChengguang Xu /* Check if lower fs supports seek operation */ 219b504c654SChengguang Xu if (old_file->f_mode & FMODE_LSEEK && 220b504c654SChengguang Xu old_file->f_op->llseek) 221b504c654SChengguang Xu skip_hole = true; 222b504c654SChengguang Xu 223e9be9d5eSMiklos Szeredi while (len) { 224e9be9d5eSMiklos Szeredi size_t this_len = OVL_COPY_UP_CHUNK_SIZE; 225e9be9d5eSMiklos Szeredi long bytes; 226e9be9d5eSMiklos Szeredi 227e9be9d5eSMiklos Szeredi if (len < this_len) 228e9be9d5eSMiklos Szeredi this_len = len; 229e9be9d5eSMiklos Szeredi 230e9be9d5eSMiklos Szeredi if (signal_pending_state(TASK_KILLABLE, current)) { 231e9be9d5eSMiklos Szeredi error = -EINTR; 232e9be9d5eSMiklos Szeredi break; 233e9be9d5eSMiklos Szeredi } 234e9be9d5eSMiklos Szeredi 235b504c654SChengguang Xu /* 236b504c654SChengguang Xu * Fill zero for hole will cost unnecessary disk space 237b504c654SChengguang Xu * and meanwhile slow down the copy-up speed, so we do 238b504c654SChengguang Xu * an optimization for hole during copy-up, it relies 239b504c654SChengguang Xu * on SEEK_DATA implementation in lower fs so if lower 240b504c654SChengguang Xu * fs does not support it, copy-up will behave as before. 241b504c654SChengguang Xu * 242b504c654SChengguang Xu * Detail logic of hole detection as below: 243b504c654SChengguang Xu * When we detect next data position is larger than current 244b504c654SChengguang Xu * position we will skip that hole, otherwise we copy 245b504c654SChengguang Xu * data in the size of OVL_COPY_UP_CHUNK_SIZE. Actually, 246b504c654SChengguang Xu * it may not recognize all kind of holes and sometimes 247b504c654SChengguang Xu * only skips partial of hole area. However, it will be 248b504c654SChengguang Xu * enough for most of the use cases. 249b504c654SChengguang Xu */ 250b504c654SChengguang Xu 251b504c654SChengguang Xu if (skip_hole && data_pos < old_pos) { 252b504c654SChengguang Xu data_pos = vfs_llseek(old_file, old_pos, SEEK_DATA); 253b504c654SChengguang Xu if (data_pos > old_pos) { 254b504c654SChengguang Xu hole_len = data_pos - old_pos; 255b504c654SChengguang Xu len -= hole_len; 256b504c654SChengguang Xu old_pos = new_pos = data_pos; 257b504c654SChengguang Xu continue; 258b504c654SChengguang Xu } else if (data_pos == -ENXIO) { 259b504c654SChengguang Xu break; 260b504c654SChengguang Xu } else if (data_pos < 0) { 261b504c654SChengguang Xu skip_hole = false; 262b504c654SChengguang Xu } 263b504c654SChengguang Xu } 264b504c654SChengguang Xu 265e9be9d5eSMiklos Szeredi bytes = do_splice_direct(old_file, &old_pos, 266e9be9d5eSMiklos Szeredi new_file, &new_pos, 267e9be9d5eSMiklos Szeredi this_len, SPLICE_F_MOVE); 268e9be9d5eSMiklos Szeredi if (bytes <= 0) { 269e9be9d5eSMiklos Szeredi error = bytes; 270e9be9d5eSMiklos Szeredi break; 271e9be9d5eSMiklos Szeredi } 272e9be9d5eSMiklos Szeredi WARN_ON(old_pos != new_pos); 273e9be9d5eSMiklos Szeredi 274e9be9d5eSMiklos Szeredi len -= bytes; 275e9be9d5eSMiklos Szeredi } 2762ea98466SAmir Goldstein out: 277c86243b0SVivek Goyal if (!error && ovl_should_sync(ofs)) 278641089c1SMiklos Szeredi error = vfs_fsync(new_file, 0); 279e9be9d5eSMiklos Szeredi fput(new_file); 280e9be9d5eSMiklos Szeredi out_fput: 281e9be9d5eSMiklos Szeredi fput(old_file); 282e9be9d5eSMiklos Szeredi return error; 283e9be9d5eSMiklos Szeredi } 284e9be9d5eSMiklos Szeredi 2850c288874SVivek Goyal static int ovl_set_size(struct dentry *upperdentry, struct kstat *stat) 2860c288874SVivek Goyal { 2870c288874SVivek Goyal struct iattr attr = { 2880c288874SVivek Goyal .ia_valid = ATTR_SIZE, 2890c288874SVivek Goyal .ia_size = stat->size, 2900c288874SVivek Goyal }; 2910c288874SVivek Goyal 2922f221d6fSChristian Brauner return notify_change(&init_user_ns, upperdentry, &attr, NULL); 2930c288874SVivek Goyal } 2940c288874SVivek Goyal 295e9be9d5eSMiklos Szeredi static int ovl_set_timestamps(struct dentry *upperdentry, struct kstat *stat) 296e9be9d5eSMiklos Szeredi { 297e9be9d5eSMiklos Szeredi struct iattr attr = { 298e9be9d5eSMiklos Szeredi .ia_valid = 299e9be9d5eSMiklos Szeredi ATTR_ATIME | ATTR_MTIME | ATTR_ATIME_SET | ATTR_MTIME_SET, 300e9be9d5eSMiklos Szeredi .ia_atime = stat->atime, 301e9be9d5eSMiklos Szeredi .ia_mtime = stat->mtime, 302e9be9d5eSMiklos Szeredi }; 303e9be9d5eSMiklos Szeredi 3042f221d6fSChristian Brauner return notify_change(&init_user_ns, upperdentry, &attr, NULL); 305e9be9d5eSMiklos Szeredi } 306e9be9d5eSMiklos Szeredi 307e9be9d5eSMiklos Szeredi int ovl_set_attr(struct dentry *upperdentry, struct kstat *stat) 308e9be9d5eSMiklos Szeredi { 309e9be9d5eSMiklos Szeredi int err = 0; 310e9be9d5eSMiklos Szeredi 311e9be9d5eSMiklos Szeredi if (!S_ISLNK(stat->mode)) { 312e9be9d5eSMiklos Szeredi struct iattr attr = { 313e9be9d5eSMiklos Szeredi .ia_valid = ATTR_MODE, 314e9be9d5eSMiklos Szeredi .ia_mode = stat->mode, 315e9be9d5eSMiklos Szeredi }; 3162f221d6fSChristian Brauner err = notify_change(&init_user_ns, upperdentry, &attr, NULL); 317e9be9d5eSMiklos Szeredi } 318e9be9d5eSMiklos Szeredi if (!err) { 319e9be9d5eSMiklos Szeredi struct iattr attr = { 320e9be9d5eSMiklos Szeredi .ia_valid = ATTR_UID | ATTR_GID, 321e9be9d5eSMiklos Szeredi .ia_uid = stat->uid, 322e9be9d5eSMiklos Szeredi .ia_gid = stat->gid, 323e9be9d5eSMiklos Szeredi }; 3242f221d6fSChristian Brauner err = notify_change(&init_user_ns, upperdentry, &attr, NULL); 325e9be9d5eSMiklos Szeredi } 326e9be9d5eSMiklos Szeredi if (!err) 327e9be9d5eSMiklos Szeredi ovl_set_timestamps(upperdentry, stat); 328e9be9d5eSMiklos Szeredi 329e9be9d5eSMiklos Szeredi return err; 330e9be9d5eSMiklos Szeredi } 331e9be9d5eSMiklos Szeredi 3321cdb0cb6SPavel Tikhomirov struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real, 3331cdb0cb6SPavel Tikhomirov bool is_upper) 3343a1e819bSAmir Goldstein { 3353a1e819bSAmir Goldstein struct ovl_fh *fh; 336ec7bbb53SAmir Goldstein int fh_type, dwords; 3373a1e819bSAmir Goldstein int buflen = MAX_HANDLE_SZ; 33805122443SAmir Goldstein uuid_t *uuid = &real->d_sb->s_uuid; 339ec7bbb53SAmir Goldstein int err; 3403a1e819bSAmir Goldstein 341ec7bbb53SAmir Goldstein /* Make sure the real fid stays 32bit aligned */ 342ec7bbb53SAmir Goldstein BUILD_BUG_ON(OVL_FH_FID_OFFSET % 4); 343ec7bbb53SAmir Goldstein BUILD_BUG_ON(MAX_HANDLE_SZ + OVL_FH_FID_OFFSET > 255); 344ec7bbb53SAmir Goldstein 345ec7bbb53SAmir Goldstein fh = kzalloc(buflen + OVL_FH_FID_OFFSET, GFP_KERNEL); 346ec7bbb53SAmir Goldstein if (!fh) 3473a1e819bSAmir Goldstein return ERR_PTR(-ENOMEM); 3483a1e819bSAmir Goldstein 3493a1e819bSAmir Goldstein /* 3503a1e819bSAmir Goldstein * We encode a non-connectable file handle for non-dir, because we 3513a1e819bSAmir Goldstein * only need to find the lower inode number and we don't want to pay 3523a1e819bSAmir Goldstein * the price or reconnecting the dentry. 3533a1e819bSAmir Goldstein */ 3543a1e819bSAmir Goldstein dwords = buflen >> 2; 355ec7bbb53SAmir Goldstein fh_type = exportfs_encode_fh(real, (void *)fh->fb.fid, &dwords, 0); 3563a1e819bSAmir Goldstein buflen = (dwords << 2); 3573a1e819bSAmir Goldstein 358ec7bbb53SAmir Goldstein err = -EIO; 3593a1e819bSAmir Goldstein if (WARN_ON(fh_type < 0) || 3603a1e819bSAmir Goldstein WARN_ON(buflen > MAX_HANDLE_SZ) || 3613a1e819bSAmir Goldstein WARN_ON(fh_type == FILEID_INVALID)) 362ec7bbb53SAmir Goldstein goto out_err; 3633a1e819bSAmir Goldstein 364cbe7fba8SAmir Goldstein fh->fb.version = OVL_FH_VERSION; 365cbe7fba8SAmir Goldstein fh->fb.magic = OVL_FH_MAGIC; 366cbe7fba8SAmir Goldstein fh->fb.type = fh_type; 367cbe7fba8SAmir Goldstein fh->fb.flags = OVL_FH_FLAG_CPU_ENDIAN; 36854fb347eSAmir Goldstein /* 36954fb347eSAmir Goldstein * When we will want to decode an overlay dentry from this handle 37054fb347eSAmir Goldstein * and all layers are on the same fs, if we get a disconncted real 37154fb347eSAmir Goldstein * dentry when we decode fid, the only way to tell if we should assign 37254fb347eSAmir Goldstein * it to upperdentry or to lowerstack is by checking this flag. 37354fb347eSAmir Goldstein */ 37454fb347eSAmir Goldstein if (is_upper) 375cbe7fba8SAmir Goldstein fh->fb.flags |= OVL_FH_FLAG_PATH_UPPER; 376ec7bbb53SAmir Goldstein fh->fb.len = sizeof(fh->fb) + buflen; 3775830fb6bSPavel Tikhomirov if (ofs->config.uuid) 378cbe7fba8SAmir Goldstein fh->fb.uuid = *uuid; 3793a1e819bSAmir Goldstein 3803a1e819bSAmir Goldstein return fh; 381ec7bbb53SAmir Goldstein 382ec7bbb53SAmir Goldstein out_err: 383ec7bbb53SAmir Goldstein kfree(fh); 384ec7bbb53SAmir Goldstein return ERR_PTR(err); 3853a1e819bSAmir Goldstein } 3863a1e819bSAmir Goldstein 387a0c236b1SAmir Goldstein int ovl_set_origin(struct ovl_fs *ofs, struct dentry *lower, 388a0c236b1SAmir Goldstein struct dentry *upper) 3893a1e819bSAmir Goldstein { 3903a1e819bSAmir Goldstein const struct ovl_fh *fh = NULL; 3913a1e819bSAmir Goldstein int err; 3923a1e819bSAmir Goldstein 3933a1e819bSAmir Goldstein /* 3943a1e819bSAmir Goldstein * When lower layer doesn't support export operations store a 'null' fh, 3953a1e819bSAmir Goldstein * so we can use the overlay.origin xattr to distignuish between a copy 3963a1e819bSAmir Goldstein * up and a pure upper inode. 3973a1e819bSAmir Goldstein */ 39802bcd157SAmir Goldstein if (ovl_can_decode_fh(lower->d_sb)) { 3991cdb0cb6SPavel Tikhomirov fh = ovl_encode_real_fh(ofs, lower, false); 4003a1e819bSAmir Goldstein if (IS_ERR(fh)) 4013a1e819bSAmir Goldstein return PTR_ERR(fh); 4023a1e819bSAmir Goldstein } 4033a1e819bSAmir Goldstein 4046266d465SMiklos Szeredi /* 4056266d465SMiklos Szeredi * Do not fail when upper doesn't support xattrs. 4066266d465SMiklos Szeredi */ 407a0c236b1SAmir Goldstein err = ovl_check_setxattr(ofs, upper, OVL_XATTR_ORIGIN, fh->buf, 408cbe7fba8SAmir Goldstein fh ? fh->fb.len : 0, 0); 4093a1e819bSAmir Goldstein kfree(fh); 4103a1e819bSAmir Goldstein 4116939f977SMiklos Szeredi /* Ignore -EPERM from setting "user.*" on symlink/special */ 4126939f977SMiklos Szeredi return err == -EPERM ? 0 : err; 4133a1e819bSAmir Goldstein } 4143a1e819bSAmir Goldstein 415016b720fSAmir Goldstein /* Store file handle of @upper dir in @index dir entry */ 416610afc0bSMiklos Szeredi static int ovl_set_upper_fh(struct ovl_fs *ofs, struct dentry *upper, 417610afc0bSMiklos Szeredi struct dentry *index) 418016b720fSAmir Goldstein { 419016b720fSAmir Goldstein const struct ovl_fh *fh; 420016b720fSAmir Goldstein int err; 421016b720fSAmir Goldstein 4221cdb0cb6SPavel Tikhomirov fh = ovl_encode_real_fh(ofs, upper, true); 423016b720fSAmir Goldstein if (IS_ERR(fh)) 424016b720fSAmir Goldstein return PTR_ERR(fh); 425016b720fSAmir Goldstein 426610afc0bSMiklos Szeredi err = ovl_do_setxattr(ofs, index, OVL_XATTR_UPPER, fh->buf, fh->fb.len); 427016b720fSAmir Goldstein 428016b720fSAmir Goldstein kfree(fh); 429016b720fSAmir Goldstein return err; 430016b720fSAmir Goldstein } 431016b720fSAmir Goldstein 432016b720fSAmir Goldstein /* 433016b720fSAmir Goldstein * Create and install index entry. 434016b720fSAmir Goldstein * 435016b720fSAmir Goldstein * Caller must hold i_mutex on indexdir. 436016b720fSAmir Goldstein */ 437016b720fSAmir Goldstein static int ovl_create_index(struct dentry *dentry, struct dentry *origin, 438016b720fSAmir Goldstein struct dentry *upper) 439016b720fSAmir Goldstein { 4401cdb0cb6SPavel Tikhomirov struct ovl_fs *ofs = OVL_FS(dentry->d_sb); 441016b720fSAmir Goldstein struct dentry *indexdir = ovl_indexdir(dentry->d_sb); 442016b720fSAmir Goldstein struct inode *dir = d_inode(indexdir); 443016b720fSAmir Goldstein struct dentry *index = NULL; 444016b720fSAmir Goldstein struct dentry *temp = NULL; 445016b720fSAmir Goldstein struct qstr name = { }; 446016b720fSAmir Goldstein int err; 447016b720fSAmir Goldstein 448016b720fSAmir Goldstein /* 449016b720fSAmir Goldstein * For now this is only used for creating index entry for directories, 450016b720fSAmir Goldstein * because non-dir are copied up directly to index and then hardlinked 451016b720fSAmir Goldstein * to upper dir. 452016b720fSAmir Goldstein * 453016b720fSAmir Goldstein * TODO: implement create index for non-dir, so we can call it when 454016b720fSAmir Goldstein * encoding file handle for non-dir in case index does not exist. 455016b720fSAmir Goldstein */ 456016b720fSAmir Goldstein if (WARN_ON(!d_is_dir(dentry))) 457016b720fSAmir Goldstein return -EIO; 458016b720fSAmir Goldstein 459016b720fSAmir Goldstein /* Directory not expected to be indexed before copy up */ 460016b720fSAmir Goldstein if (WARN_ON(ovl_test_flag(OVL_INDEX, d_inode(dentry)))) 461016b720fSAmir Goldstein return -EIO; 462016b720fSAmir Goldstein 4631cdb0cb6SPavel Tikhomirov err = ovl_get_index_name(ofs, origin, &name); 464016b720fSAmir Goldstein if (err) 465016b720fSAmir Goldstein return err; 466016b720fSAmir Goldstein 467137ec526SAmir Goldstein temp = ovl_create_temp(indexdir, OVL_CATTR(S_IFDIR | 0)); 468b148cba4SMiklos Szeredi err = PTR_ERR(temp); 469016b720fSAmir Goldstein if (IS_ERR(temp)) 470b148cba4SMiklos Szeredi goto free_name; 471016b720fSAmir Goldstein 4721cdb0cb6SPavel Tikhomirov err = ovl_set_upper_fh(ofs, upper, temp); 473016b720fSAmir Goldstein if (err) 474b148cba4SMiklos Szeredi goto out; 475016b720fSAmir Goldstein 476016b720fSAmir Goldstein index = lookup_one_len(name.name, indexdir, name.len); 477016b720fSAmir Goldstein if (IS_ERR(index)) { 478016b720fSAmir Goldstein err = PTR_ERR(index); 479016b720fSAmir Goldstein } else { 480016b720fSAmir Goldstein err = ovl_do_rename(dir, temp, dir, index, 0); 481016b720fSAmir Goldstein dput(index); 482016b720fSAmir Goldstein } 483016b720fSAmir Goldstein out: 484b148cba4SMiklos Szeredi if (err) 485b148cba4SMiklos Szeredi ovl_cleanup(dir, temp); 486016b720fSAmir Goldstein dput(temp); 487b148cba4SMiklos Szeredi free_name: 488016b720fSAmir Goldstein kfree(name.name); 489016b720fSAmir Goldstein return err; 490016b720fSAmir Goldstein } 491016b720fSAmir Goldstein 49223f0ab13SMiklos Szeredi struct ovl_copy_up_ctx { 493a6fb235aSMiklos Szeredi struct dentry *parent; 49423f0ab13SMiklos Szeredi struct dentry *dentry; 49523f0ab13SMiklos Szeredi struct path lowerpath; 49623f0ab13SMiklos Szeredi struct kstat stat; 49723f0ab13SMiklos Szeredi struct kstat pstat; 49823f0ab13SMiklos Szeredi const char *link; 49959be0971SAmir Goldstein struct dentry *destdir; 50059be0971SAmir Goldstein struct qstr destname; 50123f0ab13SMiklos Szeredi struct dentry *workdir; 50259be0971SAmir Goldstein bool origin; 503016b720fSAmir Goldstein bool indexed; 50444d5bf10SVivek Goyal bool metacopy; 50523f0ab13SMiklos Szeredi }; 50623f0ab13SMiklos Szeredi 507f4439de1SAmir Goldstein static int ovl_link_up(struct ovl_copy_up_ctx *c) 508f4439de1SAmir Goldstein { 509f4439de1SAmir Goldstein int err; 510f4439de1SAmir Goldstein struct dentry *upper; 511f4439de1SAmir Goldstein struct dentry *upperdir = ovl_dentry_upper(c->parent); 512f4439de1SAmir Goldstein struct inode *udir = d_inode(upperdir); 513f4439de1SAmir Goldstein 514f4439de1SAmir Goldstein /* Mark parent "impure" because it may now contain non-pure upper */ 515f4439de1SAmir Goldstein err = ovl_set_impure(c->parent, upperdir); 516f4439de1SAmir Goldstein if (err) 517f4439de1SAmir Goldstein return err; 518f4439de1SAmir Goldstein 519f4439de1SAmir Goldstein err = ovl_set_nlink_lower(c->dentry); 520f4439de1SAmir Goldstein if (err) 521f4439de1SAmir Goldstein return err; 522f4439de1SAmir Goldstein 523f4439de1SAmir Goldstein inode_lock_nested(udir, I_MUTEX_PARENT); 524f4439de1SAmir Goldstein upper = lookup_one_len(c->dentry->d_name.name, upperdir, 525f4439de1SAmir Goldstein c->dentry->d_name.len); 526f4439de1SAmir Goldstein err = PTR_ERR(upper); 527f4439de1SAmir Goldstein if (!IS_ERR(upper)) { 5286cf00764SAmir Goldstein err = ovl_do_link(ovl_dentry_upper(c->dentry), udir, upper); 529f4439de1SAmir Goldstein dput(upper); 530f4439de1SAmir Goldstein 531f4439de1SAmir Goldstein if (!err) { 532f4439de1SAmir Goldstein /* Restore timestamps on parent (best effort) */ 533f4439de1SAmir Goldstein ovl_set_timestamps(upperdir, &c->pstat); 534f4439de1SAmir Goldstein ovl_dentry_set_upper_alias(c->dentry); 535f4439de1SAmir Goldstein } 536f4439de1SAmir Goldstein } 537f4439de1SAmir Goldstein inode_unlock(udir); 538aa3ff3c1SAmir Goldstein if (err) 539aa3ff3c1SAmir Goldstein return err; 540aa3ff3c1SAmir Goldstein 541aa3ff3c1SAmir Goldstein err = ovl_set_nlink_upper(c->dentry); 542f4439de1SAmir Goldstein 543f4439de1SAmir Goldstein return err; 544f4439de1SAmir Goldstein } 545f4439de1SAmir Goldstein 54623f0ab13SMiklos Szeredi static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp) 54702209d10SAmir Goldstein { 548c86243b0SVivek Goyal struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); 54972db8211SAmir Goldstein struct inode *inode = d_inode(c->dentry); 55072db8211SAmir Goldstein struct path upperpath, datapath; 55102209d10SAmir Goldstein int err; 55202209d10SAmir Goldstein 55372db8211SAmir Goldstein ovl_path_upper(c->dentry, &upperpath); 55472db8211SAmir Goldstein if (WARN_ON(upperpath.dentry != NULL)) 55572db8211SAmir Goldstein return -EIO; 55672db8211SAmir Goldstein 55772db8211SAmir Goldstein upperpath.dentry = temp; 55872db8211SAmir Goldstein 5595f32879eSVivek Goyal /* 5605f32879eSVivek Goyal * Copy up data first and then xattrs. Writing data after 5615f32879eSVivek Goyal * xattrs will remove security.capability xattr automatically. 5625f32879eSVivek Goyal */ 5635f32879eSVivek Goyal if (S_ISREG(c->stat.mode) && !c->metacopy) { 5645f32879eSVivek Goyal ovl_path_lowerdata(c->dentry, &datapath); 565c86243b0SVivek Goyal err = ovl_copy_up_data(ofs, &datapath, &upperpath, 566c86243b0SVivek Goyal c->stat.size); 5675f32879eSVivek Goyal if (err) 5685f32879eSVivek Goyal return err; 5695f32879eSVivek Goyal } 5705f32879eSVivek Goyal 571610afc0bSMiklos Szeredi err = ovl_copy_xattr(c->dentry->d_sb, c->lowerpath.dentry, temp); 57202209d10SAmir Goldstein if (err) 57302209d10SAmir Goldstein return err; 57402209d10SAmir Goldstein 57572db8211SAmir Goldstein if (inode->i_flags & OVL_COPY_I_FLAGS_MASK) { 57672db8211SAmir Goldstein /* 57772db8211SAmir Goldstein * Copy the fileattr inode flags that are the source of already 57872db8211SAmir Goldstein * copied i_flags 57972db8211SAmir Goldstein */ 580096a218aSAmir Goldstein err = ovl_copy_fileattr(inode, &c->lowerpath, &upperpath); 58172db8211SAmir Goldstein if (err) 58272db8211SAmir Goldstein return err; 58372db8211SAmir Goldstein } 58472db8211SAmir Goldstein 58502209d10SAmir Goldstein /* 58602209d10SAmir Goldstein * Store identifier of lower inode in upper inode xattr to 58702209d10SAmir Goldstein * allow lookup of the copy up origin inode. 58802209d10SAmir Goldstein * 58902209d10SAmir Goldstein * Don't set origin when we are breaking the association with a lower 59002209d10SAmir Goldstein * hard link. 59102209d10SAmir Goldstein */ 59259be0971SAmir Goldstein if (c->origin) { 593a0c236b1SAmir Goldstein err = ovl_set_origin(ofs, c->lowerpath.dentry, temp); 59402209d10SAmir Goldstein if (err) 59502209d10SAmir Goldstein return err; 59602209d10SAmir Goldstein } 59702209d10SAmir Goldstein 5980c288874SVivek Goyal if (c->metacopy) { 599a0c236b1SAmir Goldstein err = ovl_check_setxattr(ofs, temp, OVL_XATTR_METACOPY, 6000c288874SVivek Goyal NULL, 0, -EOPNOTSUPP); 6010c288874SVivek Goyal if (err) 6020c288874SVivek Goyal return err; 6030c288874SVivek Goyal } 6040c288874SVivek Goyal 605bd64e575SVivek Goyal inode_lock(temp->d_inode); 606b504c654SChengguang Xu if (S_ISREG(c->stat.mode)) 6070c288874SVivek Goyal err = ovl_set_size(temp, &c->stat); 6080c288874SVivek Goyal if (!err) 609bd64e575SVivek Goyal err = ovl_set_attr(temp, &c->stat); 610bd64e575SVivek Goyal inode_unlock(temp->d_inode); 611bd64e575SVivek Goyal 612bd64e575SVivek Goyal return err; 61302209d10SAmir Goldstein } 61402209d10SAmir Goldstein 6156b52243fSMiklos Szeredi struct ovl_cu_creds { 6166b52243fSMiklos Szeredi const struct cred *old; 6176b52243fSMiklos Szeredi struct cred *new; 618b10cdcdcSAmir Goldstein }; 619b10cdcdcSAmir Goldstein 6206b52243fSMiklos Szeredi static int ovl_prep_cu_creds(struct dentry *dentry, struct ovl_cu_creds *cc) 621b10cdcdcSAmir Goldstein { 622b10cdcdcSAmir Goldstein int err; 623b10cdcdcSAmir Goldstein 6246b52243fSMiklos Szeredi cc->old = cc->new = NULL; 6256b52243fSMiklos Szeredi err = security_inode_copy_up(dentry, &cc->new); 6266b52243fSMiklos Szeredi if (err < 0) 627b10cdcdcSAmir Goldstein return err; 6286b52243fSMiklos Szeredi 6296b52243fSMiklos Szeredi if (cc->new) 6306b52243fSMiklos Szeredi cc->old = override_creds(cc->new); 6316b52243fSMiklos Szeredi 6326b52243fSMiklos Szeredi return 0; 6336b52243fSMiklos Szeredi } 6346b52243fSMiklos Szeredi 6356b52243fSMiklos Szeredi static void ovl_revert_cu_creds(struct ovl_cu_creds *cc) 6366b52243fSMiklos Szeredi { 6376b52243fSMiklos Szeredi if (cc->new) { 6386b52243fSMiklos Szeredi revert_creds(cc->old); 6396b52243fSMiklos Szeredi put_cred(cc->new); 6406b52243fSMiklos Szeredi } 641b10cdcdcSAmir Goldstein } 642b10cdcdcSAmir Goldstein 643b10cdcdcSAmir Goldstein /* 644b10cdcdcSAmir Goldstein * Copyup using workdir to prepare temp file. Used when copying up directories, 645b10cdcdcSAmir Goldstein * special files or when upper fs doesn't support O_TMPFILE. 646b10cdcdcSAmir Goldstein */ 647b10cdcdcSAmir Goldstein static int ovl_copy_up_workdir(struct ovl_copy_up_ctx *c) 648b10cdcdcSAmir Goldstein { 649b79e05aaSAmir Goldstein struct inode *inode; 6506b52243fSMiklos Szeredi struct inode *udir = d_inode(c->destdir), *wdir = d_inode(c->workdir); 6516b52243fSMiklos Szeredi struct dentry *temp, *upper; 6526b52243fSMiklos Szeredi struct ovl_cu_creds cc; 6537d90b853SMiklos Szeredi int err; 6546b52243fSMiklos Szeredi struct ovl_cattr cattr = { 6556b52243fSMiklos Szeredi /* Can't properly set mode on creation because of the umask */ 6566b52243fSMiklos Szeredi .mode = c->stat.mode & S_IFMT, 6576b52243fSMiklos Szeredi .rdev = c->stat.rdev, 6586b52243fSMiklos Szeredi .link = c->link 6596b52243fSMiklos Szeredi }; 6607d90b853SMiklos Szeredi 661773cb4c5SAmir Goldstein /* workdir and destdir could be the same when copying up to indexdir */ 662773cb4c5SAmir Goldstein err = -EIO; 663773cb4c5SAmir Goldstein if (lock_rename(c->workdir, c->destdir) != NULL) 664773cb4c5SAmir Goldstein goto unlock; 665b10cdcdcSAmir Goldstein 6666b52243fSMiklos Szeredi err = ovl_prep_cu_creds(c->dentry, &cc); 6676b52243fSMiklos Szeredi if (err) 6686b52243fSMiklos Szeredi goto unlock; 6696b52243fSMiklos Szeredi 6706b52243fSMiklos Szeredi temp = ovl_create_temp(c->workdir, &cattr); 6716b52243fSMiklos Szeredi ovl_revert_cu_creds(&cc); 6726b52243fSMiklos Szeredi 673b10cdcdcSAmir Goldstein err = PTR_ERR(temp); 674b10cdcdcSAmir Goldstein if (IS_ERR(temp)) 675b10cdcdcSAmir Goldstein goto unlock; 676b10cdcdcSAmir Goldstein 677b10cdcdcSAmir Goldstein err = ovl_copy_up_inode(c, temp); 678b10cdcdcSAmir Goldstein if (err) 679b10cdcdcSAmir Goldstein goto cleanup; 680b10cdcdcSAmir Goldstein 681b10cdcdcSAmir Goldstein if (S_ISDIR(c->stat.mode) && c->indexed) { 682b10cdcdcSAmir Goldstein err = ovl_create_index(c->dentry, c->lowerpath.dentry, temp); 683b10cdcdcSAmir Goldstein if (err) 684b10cdcdcSAmir Goldstein goto cleanup; 685b10cdcdcSAmir Goldstein } 686b10cdcdcSAmir Goldstein 6876b52243fSMiklos Szeredi upper = lookup_one_len(c->destname.name, c->destdir, c->destname.len); 6886b52243fSMiklos Szeredi err = PTR_ERR(upper); 6896b52243fSMiklos Szeredi if (IS_ERR(upper)) 6906b52243fSMiklos Szeredi goto cleanup; 6916b52243fSMiklos Szeredi 6926b52243fSMiklos Szeredi err = ovl_do_rename(wdir, temp, udir, upper, 0); 6936b52243fSMiklos Szeredi dput(upper); 694b10cdcdcSAmir Goldstein if (err) 695b10cdcdcSAmir Goldstein goto cleanup; 696b10cdcdcSAmir Goldstein 697b10cdcdcSAmir Goldstein if (!c->metacopy) 698b10cdcdcSAmir Goldstein ovl_set_upperdata(d_inode(c->dentry)); 699b10cdcdcSAmir Goldstein inode = d_inode(c->dentry); 7006b52243fSMiklos Szeredi ovl_inode_update(inode, temp); 701b10cdcdcSAmir Goldstein if (S_ISDIR(inode->i_mode)) 702b10cdcdcSAmir Goldstein ovl_set_flag(OVL_WHITEOUTS, inode); 703b10cdcdcSAmir Goldstein unlock: 704b10cdcdcSAmir Goldstein unlock_rename(c->workdir, c->destdir); 705b10cdcdcSAmir Goldstein 706b10cdcdcSAmir Goldstein return err; 707b10cdcdcSAmir Goldstein 708b10cdcdcSAmir Goldstein cleanup: 7096b52243fSMiklos Szeredi ovl_cleanup(wdir, temp); 7106b52243fSMiklos Szeredi dput(temp); 711b10cdcdcSAmir Goldstein goto unlock; 712b10cdcdcSAmir Goldstein } 713b10cdcdcSAmir Goldstein 714b10cdcdcSAmir Goldstein /* Copyup using O_TMPFILE which does not require cross dir locking */ 715b10cdcdcSAmir Goldstein static int ovl_copy_up_tmpfile(struct ovl_copy_up_ctx *c) 716b10cdcdcSAmir Goldstein { 7176b52243fSMiklos Szeredi struct inode *udir = d_inode(c->destdir); 7186b52243fSMiklos Szeredi struct dentry *temp, *upper; 7196b52243fSMiklos Szeredi struct ovl_cu_creds cc; 720b10cdcdcSAmir Goldstein int err; 721b10cdcdcSAmir Goldstein 7226b52243fSMiklos Szeredi err = ovl_prep_cu_creds(c->dentry, &cc); 7236b52243fSMiklos Szeredi if (err) 7246b52243fSMiklos Szeredi return err; 7256b52243fSMiklos Szeredi 7266b52243fSMiklos Szeredi temp = ovl_do_tmpfile(c->workdir, c->stat.mode); 7276b52243fSMiklos Szeredi ovl_revert_cu_creds(&cc); 7286b52243fSMiklos Szeredi 729b148cba4SMiklos Szeredi if (IS_ERR(temp)) 730b148cba4SMiklos Szeredi return PTR_ERR(temp); 731e9be9d5eSMiklos Szeredi 73223f0ab13SMiklos Szeredi err = ovl_copy_up_inode(c, temp); 733e9be9d5eSMiklos Szeredi if (err) 7346b52243fSMiklos Szeredi goto out_dput; 7353a1e819bSAmir Goldstein 7366b52243fSMiklos Szeredi inode_lock_nested(udir, I_MUTEX_PARENT); 7376b52243fSMiklos Szeredi 7386b52243fSMiklos Szeredi upper = lookup_one_len(c->destname.name, c->destdir, c->destname.len); 7396b52243fSMiklos Szeredi err = PTR_ERR(upper); 7406b52243fSMiklos Szeredi if (!IS_ERR(upper)) { 7416b52243fSMiklos Szeredi err = ovl_do_link(temp, udir, upper); 7426b52243fSMiklos Szeredi dput(upper); 7436b52243fSMiklos Szeredi } 7446b52243fSMiklos Szeredi inode_unlock(udir); 7456b52243fSMiklos Szeredi 746e9be9d5eSMiklos Szeredi if (err) 7476b52243fSMiklos Szeredi goto out_dput; 748e9be9d5eSMiklos Szeredi 7490c288874SVivek Goyal if (!c->metacopy) 7500c288874SVivek Goyal ovl_set_upperdata(d_inode(c->dentry)); 7516b52243fSMiklos Szeredi ovl_inode_update(d_inode(c->dentry), temp); 752b79e05aaSAmir Goldstein 7536b52243fSMiklos Szeredi return 0; 7546b52243fSMiklos Szeredi 7556b52243fSMiklos Szeredi out_dput: 756e85f82ffSMiklos Szeredi dput(temp); 757e9be9d5eSMiklos Szeredi return err; 758e9be9d5eSMiklos Szeredi } 759e9be9d5eSMiklos Szeredi 760e9be9d5eSMiklos Szeredi /* 761e9be9d5eSMiklos Szeredi * Copy up a single dentry 762e9be9d5eSMiklos Szeredi * 763a6c60655SMiklos Szeredi * All renames start with copy up of source if necessary. The actual 764a6c60655SMiklos Szeredi * rename will only proceed once the copy up was successful. Copy up uses 765a6c60655SMiklos Szeredi * upper parent i_mutex for exclusion. Since rename can change d_parent it 766a6c60655SMiklos Szeredi * is possible that the copy up will lock the old parent. At that point 767a6c60655SMiklos Szeredi * the file will have already been copied up anyway. 768e9be9d5eSMiklos Szeredi */ 769a6fb235aSMiklos Szeredi static int ovl_do_copy_up(struct ovl_copy_up_ctx *c) 770e9be9d5eSMiklos Szeredi { 771e9be9d5eSMiklos Szeredi int err; 7721cdb0cb6SPavel Tikhomirov struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); 773016b720fSAmir Goldstein bool to_index = false; 77459be0971SAmir Goldstein 775016b720fSAmir Goldstein /* 776016b720fSAmir Goldstein * Indexed non-dir is copied up directly to the index entry and then 777016b720fSAmir Goldstein * hardlinked to upper dir. Indexed dir is copied up to indexdir, 778016b720fSAmir Goldstein * then index entry is created and then copied up dir installed. 779016b720fSAmir Goldstein * Copying dir up to indexdir instead of workdir simplifies locking. 780016b720fSAmir Goldstein */ 781016b720fSAmir Goldstein if (ovl_need_index(c->dentry)) { 782016b720fSAmir Goldstein c->indexed = true; 783016b720fSAmir Goldstein if (S_ISDIR(c->stat.mode)) 784016b720fSAmir Goldstein c->workdir = ovl_indexdir(c->dentry->d_sb); 785016b720fSAmir Goldstein else 786016b720fSAmir Goldstein to_index = true; 787016b720fSAmir Goldstein } 788016b720fSAmir Goldstein 789016b720fSAmir Goldstein if (S_ISDIR(c->stat.mode) || c->stat.nlink == 1 || to_index) 79059be0971SAmir Goldstein c->origin = true; 79159be0971SAmir Goldstein 792016b720fSAmir Goldstein if (to_index) { 79359be0971SAmir Goldstein c->destdir = ovl_indexdir(c->dentry->d_sb); 7941cdb0cb6SPavel Tikhomirov err = ovl_get_index_name(ofs, c->lowerpath.dentry, &c->destname); 795f3a15685SAmir Goldstein if (err) 796f3a15685SAmir Goldstein return err; 797aa3ff3c1SAmir Goldstein } else if (WARN_ON(!c->parent)) { 798aa3ff3c1SAmir Goldstein /* Disconnected dentry must be copied up to index dir */ 799aa3ff3c1SAmir Goldstein return -EIO; 80059be0971SAmir Goldstein } else { 80159be0971SAmir Goldstein /* 80259be0971SAmir Goldstein * Mark parent "impure" because it may now contain non-pure 80359be0971SAmir Goldstein * upper 80459be0971SAmir Goldstein */ 80559be0971SAmir Goldstein err = ovl_set_impure(c->parent, c->destdir); 80659be0971SAmir Goldstein if (err) 80759be0971SAmir Goldstein return err; 80859be0971SAmir Goldstein } 809f3a15685SAmir Goldstein 81001ad3eb8SAmir Goldstein /* Should we copyup with O_TMPFILE or with workdir? */ 811b10cdcdcSAmir Goldstein if (S_ISREG(c->stat.mode) && ofs->tmpfile) 812b10cdcdcSAmir Goldstein err = ovl_copy_up_tmpfile(c); 813b10cdcdcSAmir Goldstein else 814b10cdcdcSAmir Goldstein err = ovl_copy_up_workdir(c); 815aa3ff3c1SAmir Goldstein if (err) 816aa3ff3c1SAmir Goldstein goto out; 817aa3ff3c1SAmir Goldstein 818aa3ff3c1SAmir Goldstein if (c->indexed) 81959be0971SAmir Goldstein ovl_set_flag(OVL_INDEX, d_inode(c->dentry)); 820016b720fSAmir Goldstein 821016b720fSAmir Goldstein if (to_index) { 822aa3ff3c1SAmir Goldstein /* Initialize nlink for copy up of disconnected dentry */ 823aa3ff3c1SAmir Goldstein err = ovl_set_nlink_upper(c->dentry); 824aa3ff3c1SAmir Goldstein } else { 82559be0971SAmir Goldstein struct inode *udir = d_inode(c->destdir); 82659be0971SAmir Goldstein 82759be0971SAmir Goldstein /* Restore timestamps on parent (best effort) */ 82859be0971SAmir Goldstein inode_lock(udir); 82959be0971SAmir Goldstein ovl_set_timestamps(c->destdir, &c->pstat); 83059be0971SAmir Goldstein inode_unlock(udir); 83159be0971SAmir Goldstein 83259be0971SAmir Goldstein ovl_dentry_set_upper_alias(c->dentry); 833fd210b7dSMiklos Szeredi } 834a6fb235aSMiklos Szeredi 835aa3ff3c1SAmir Goldstein out: 836aa3ff3c1SAmir Goldstein if (to_index) 837aa3ff3c1SAmir Goldstein kfree(c->destname.name); 838a6fb235aSMiklos Szeredi return err; 839a6fb235aSMiklos Szeredi } 840a6fb235aSMiklos Szeredi 84144d5bf10SVivek Goyal static bool ovl_need_meta_copy_up(struct dentry *dentry, umode_t mode, 84244d5bf10SVivek Goyal int flags) 84344d5bf10SVivek Goyal { 84444d5bf10SVivek Goyal struct ovl_fs *ofs = dentry->d_sb->s_fs_info; 84544d5bf10SVivek Goyal 84644d5bf10SVivek Goyal if (!ofs->config.metacopy) 84744d5bf10SVivek Goyal return false; 84844d5bf10SVivek Goyal 84944d5bf10SVivek Goyal if (!S_ISREG(mode)) 85044d5bf10SVivek Goyal return false; 85144d5bf10SVivek Goyal 85244d5bf10SVivek Goyal if (flags && ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC))) 85344d5bf10SVivek Goyal return false; 85444d5bf10SVivek Goyal 85544d5bf10SVivek Goyal return true; 85644d5bf10SVivek Goyal } 85744d5bf10SVivek Goyal 858de7a52c9SMiklos Szeredi static ssize_t ovl_getxattr(struct dentry *dentry, char *name, char **value) 859fee0f298SMiklos Szeredi { 860fee0f298SMiklos Szeredi ssize_t res; 861de7a52c9SMiklos Szeredi char *buf; 862fee0f298SMiklos Szeredi 863c7c7a1a1STycho Andersen res = vfs_getxattr(&init_user_ns, dentry, name, NULL, 0); 864fee0f298SMiklos Szeredi if (res == -ENODATA || res == -EOPNOTSUPP) 865de7a52c9SMiklos Szeredi res = 0; 866fee0f298SMiklos Szeredi 867de7a52c9SMiklos Szeredi if (res > 0) { 868de7a52c9SMiklos Szeredi buf = kzalloc(res, GFP_KERNEL); 869fee0f298SMiklos Szeredi if (!buf) 870fee0f298SMiklos Szeredi return -ENOMEM; 871fee0f298SMiklos Szeredi 872c7c7a1a1STycho Andersen res = vfs_getxattr(&init_user_ns, dentry, name, buf, res); 873fee0f298SMiklos Szeredi if (res < 0) 874fee0f298SMiklos Szeredi kfree(buf); 875de7a52c9SMiklos Szeredi else 876de7a52c9SMiklos Szeredi *value = buf; 877de7a52c9SMiklos Szeredi } 878fee0f298SMiklos Szeredi return res; 879fee0f298SMiklos Szeredi } 880fee0f298SMiklos Szeredi 8810c288874SVivek Goyal /* Copy up data of an inode which was copied up metadata only in the past. */ 8820c288874SVivek Goyal static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c) 8830c288874SVivek Goyal { 884c86243b0SVivek Goyal struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); 8854f93b426SVivek Goyal struct path upperpath, datapath; 8860c288874SVivek Goyal int err; 887993a0b2aSVivek Goyal char *capability = NULL; 8883f649ab7SKees Cook ssize_t cap_size; 8890c288874SVivek Goyal 8900c288874SVivek Goyal ovl_path_upper(c->dentry, &upperpath); 8910c288874SVivek Goyal if (WARN_ON(upperpath.dentry == NULL)) 8920c288874SVivek Goyal return -EIO; 8930c288874SVivek Goyal 8944f93b426SVivek Goyal ovl_path_lowerdata(c->dentry, &datapath); 8954f93b426SVivek Goyal if (WARN_ON(datapath.dentry == NULL)) 8964f93b426SVivek Goyal return -EIO; 8974f93b426SVivek Goyal 898993a0b2aSVivek Goyal if (c->stat.size) { 899993a0b2aSVivek Goyal err = cap_size = ovl_getxattr(upperpath.dentry, XATTR_NAME_CAPS, 900de7a52c9SMiklos Szeredi &capability); 901de7a52c9SMiklos Szeredi if (cap_size < 0) 902993a0b2aSVivek Goyal goto out; 903993a0b2aSVivek Goyal } 904993a0b2aSVivek Goyal 905c86243b0SVivek Goyal err = ovl_copy_up_data(ofs, &datapath, &upperpath, c->stat.size); 9060c288874SVivek Goyal if (err) 907993a0b2aSVivek Goyal goto out_free; 908993a0b2aSVivek Goyal 909993a0b2aSVivek Goyal /* 910993a0b2aSVivek Goyal * Writing to upper file will clear security.capability xattr. We 911993a0b2aSVivek Goyal * don't want that to happen for normal copy-up operation. 912993a0b2aSVivek Goyal */ 913993a0b2aSVivek Goyal if (capability) { 914c7c7a1a1STycho Andersen err = vfs_setxattr(&init_user_ns, upperpath.dentry, 915c7c7a1a1STycho Andersen XATTR_NAME_CAPS, capability, cap_size, 0); 916993a0b2aSVivek Goyal if (err) 917993a0b2aSVivek Goyal goto out_free; 918993a0b2aSVivek Goyal } 919993a0b2aSVivek Goyal 9200c288874SVivek Goyal 921610afc0bSMiklos Szeredi err = ovl_do_removexattr(ofs, upperpath.dentry, OVL_XATTR_METACOPY); 9220c288874SVivek Goyal if (err) 923993a0b2aSVivek Goyal goto out_free; 9240c288874SVivek Goyal 9250c288874SVivek Goyal ovl_set_upperdata(d_inode(c->dentry)); 926993a0b2aSVivek Goyal out_free: 927993a0b2aSVivek Goyal kfree(capability); 928993a0b2aSVivek Goyal out: 9290c288874SVivek Goyal return err; 9300c288874SVivek Goyal } 9310c288874SVivek Goyal 932a6fb235aSMiklos Szeredi static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, 933a6fb235aSMiklos Szeredi int flags) 934a6fb235aSMiklos Szeredi { 935a6fb235aSMiklos Szeredi int err; 936a6fb235aSMiklos Szeredi DEFINE_DELAYED_CALL(done); 937a6fb235aSMiklos Szeredi struct path parentpath; 938a6fb235aSMiklos Szeredi struct ovl_copy_up_ctx ctx = { 939a6fb235aSMiklos Szeredi .parent = parent, 940a6fb235aSMiklos Szeredi .dentry = dentry, 941a6fb235aSMiklos Szeredi .workdir = ovl_workdir(dentry), 942a6fb235aSMiklos Szeredi }; 943a6fb235aSMiklos Szeredi 944a6fb235aSMiklos Szeredi if (WARN_ON(!ctx.workdir)) 945a6fb235aSMiklos Szeredi return -EROFS; 946a6fb235aSMiklos Szeredi 947a6fb235aSMiklos Szeredi ovl_path_lower(dentry, &ctx.lowerpath); 948a6fb235aSMiklos Szeredi err = vfs_getattr(&ctx.lowerpath, &ctx.stat, 949a6fb235aSMiklos Szeredi STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT); 950a6fb235aSMiklos Szeredi if (err) 951a6fb235aSMiklos Szeredi return err; 952a6fb235aSMiklos Szeredi 95344d5bf10SVivek Goyal ctx.metacopy = ovl_need_meta_copy_up(dentry, ctx.stat.mode, flags); 95444d5bf10SVivek Goyal 955aa3ff3c1SAmir Goldstein if (parent) { 956a6fb235aSMiklos Szeredi ovl_path_upper(parent, &parentpath); 95759be0971SAmir Goldstein ctx.destdir = parentpath.dentry; 95859be0971SAmir Goldstein ctx.destname = dentry->d_name; 959a6fb235aSMiklos Szeredi 960a6fb235aSMiklos Szeredi err = vfs_getattr(&parentpath, &ctx.pstat, 961aa3ff3c1SAmir Goldstein STATX_ATIME | STATX_MTIME, 962aa3ff3c1SAmir Goldstein AT_STATX_SYNC_AS_STAT); 963a6fb235aSMiklos Szeredi if (err) 964a6fb235aSMiklos Szeredi return err; 965aa3ff3c1SAmir Goldstein } 966a6fb235aSMiklos Szeredi 967a6fb235aSMiklos Szeredi /* maybe truncate regular file. this has no effect on dirs */ 968a6fb235aSMiklos Szeredi if (flags & O_TRUNC) 969a6fb235aSMiklos Szeredi ctx.stat.size = 0; 970a6fb235aSMiklos Szeredi 971a6fb235aSMiklos Szeredi if (S_ISLNK(ctx.stat.mode)) { 972a6fb235aSMiklos Szeredi ctx.link = vfs_get_link(ctx.lowerpath.dentry, &done); 973a6fb235aSMiklos Szeredi if (IS_ERR(ctx.link)) 974a6fb235aSMiklos Szeredi return PTR_ERR(ctx.link); 975a6fb235aSMiklos Szeredi } 976a6fb235aSMiklos Szeredi 9770c288874SVivek Goyal err = ovl_copy_up_start(dentry, flags); 978fd210b7dSMiklos Szeredi /* err < 0: interrupted, err > 0: raced with another copy-up */ 979fd210b7dSMiklos Szeredi if (unlikely(err)) { 980fd210b7dSMiklos Szeredi if (err > 0) 981fd210b7dSMiklos Szeredi err = 0; 982fd210b7dSMiklos Szeredi } else { 98359be0971SAmir Goldstein if (!ovl_dentry_upper(dentry)) 984a6fb235aSMiklos Szeredi err = ovl_do_copy_up(&ctx); 985aa3ff3c1SAmir Goldstein if (!err && parent && !ovl_dentry_has_upper_alias(dentry)) 986f4439de1SAmir Goldstein err = ovl_link_up(&ctx); 9870c288874SVivek Goyal if (!err && ovl_dentry_needs_data_copy_up_locked(dentry, flags)) 9880c288874SVivek Goyal err = ovl_copy_up_meta_inode_data(&ctx); 989fd210b7dSMiklos Szeredi ovl_copy_up_end(dentry); 990fd210b7dSMiklos Szeredi } 9917764235bSMiklos Szeredi do_delayed_call(&done); 992e9be9d5eSMiklos Szeredi 993e9be9d5eSMiklos Szeredi return err; 994e9be9d5eSMiklos Szeredi } 995e9be9d5eSMiklos Szeredi 9965ac8e802Syoungjun static int ovl_copy_up_flags(struct dentry *dentry, int flags) 997e9be9d5eSMiklos Szeredi { 9988eac98b8SVivek Goyal int err = 0; 9997b279bbfSDan Carpenter const struct cred *old_cred; 1000aa3ff3c1SAmir Goldstein bool disconnected = (dentry->d_flags & DCACHE_DISCONNECTED); 1001aa3ff3c1SAmir Goldstein 1002aa3ff3c1SAmir Goldstein /* 1003aa3ff3c1SAmir Goldstein * With NFS export, copy up can get called for a disconnected non-dir. 1004aa3ff3c1SAmir Goldstein * In this case, we will copy up lower inode to index dir without 1005aa3ff3c1SAmir Goldstein * linking it to upper dir. 1006aa3ff3c1SAmir Goldstein */ 1007aa3ff3c1SAmir Goldstein if (WARN_ON(disconnected && d_is_dir(dentry))) 1008aa3ff3c1SAmir Goldstein return -EIO; 1009e9be9d5eSMiklos Szeredi 10107b279bbfSDan Carpenter old_cred = ovl_override_creds(dentry->d_sb); 1011e9be9d5eSMiklos Szeredi while (!err) { 1012e9be9d5eSMiklos Szeredi struct dentry *next; 1013aa3ff3c1SAmir Goldstein struct dentry *parent = NULL; 1014e9be9d5eSMiklos Szeredi 10150c288874SVivek Goyal if (ovl_already_copied_up(dentry, flags)) 1016e9be9d5eSMiklos Szeredi break; 1017e9be9d5eSMiklos Szeredi 1018e9be9d5eSMiklos Szeredi next = dget(dentry); 1019e9be9d5eSMiklos Szeredi /* find the topmost dentry not yet copied up */ 1020aa3ff3c1SAmir Goldstein for (; !disconnected;) { 1021e9be9d5eSMiklos Szeredi parent = dget_parent(next); 1022e9be9d5eSMiklos Szeredi 102359be0971SAmir Goldstein if (ovl_dentry_upper(parent)) 1024e9be9d5eSMiklos Szeredi break; 1025e9be9d5eSMiklos Szeredi 1026e9be9d5eSMiklos Szeredi dput(next); 1027e9be9d5eSMiklos Szeredi next = parent; 1028e9be9d5eSMiklos Szeredi } 1029e9be9d5eSMiklos Szeredi 1030a6fb235aSMiklos Szeredi err = ovl_copy_up_one(parent, next, flags); 1031e9be9d5eSMiklos Szeredi 1032e9be9d5eSMiklos Szeredi dput(parent); 1033e9be9d5eSMiklos Szeredi dput(next); 1034e9be9d5eSMiklos Szeredi } 10358eac98b8SVivek Goyal revert_creds(old_cred); 1036e9be9d5eSMiklos Szeredi 1037e9be9d5eSMiklos Szeredi return err; 1038e9be9d5eSMiklos Szeredi } 10399aba6521SAmir Goldstein 1040d6eac039SVivek Goyal static bool ovl_open_need_copy_up(struct dentry *dentry, int flags) 1041d6eac039SVivek Goyal { 1042d6eac039SVivek Goyal /* Copy up of disconnected dentry does not set upper alias */ 10430c288874SVivek Goyal if (ovl_already_copied_up(dentry, flags)) 1044d6eac039SVivek Goyal return false; 1045d6eac039SVivek Goyal 1046d6eac039SVivek Goyal if (special_file(d_inode(dentry)->i_mode)) 1047d6eac039SVivek Goyal return false; 1048d6eac039SVivek Goyal 10490c288874SVivek Goyal if (!ovl_open_flags_need_copy_up(flags)) 1050d6eac039SVivek Goyal return false; 1051d6eac039SVivek Goyal 1052d6eac039SVivek Goyal return true; 1053d6eac039SVivek Goyal } 1054d6eac039SVivek Goyal 10553428030dSAmir Goldstein int ovl_maybe_copy_up(struct dentry *dentry, int flags) 1056d6eac039SVivek Goyal { 1057d6eac039SVivek Goyal int err = 0; 1058d6eac039SVivek Goyal 10593428030dSAmir Goldstein if (ovl_open_need_copy_up(dentry, flags)) { 1060d6eac039SVivek Goyal err = ovl_want_write(dentry); 1061d6eac039SVivek Goyal if (!err) { 10623428030dSAmir Goldstein err = ovl_copy_up_flags(dentry, flags); 1063d6eac039SVivek Goyal ovl_drop_write(dentry); 1064d6eac039SVivek Goyal } 1065d6eac039SVivek Goyal } 1066d6eac039SVivek Goyal 1067d6eac039SVivek Goyal return err; 1068d6eac039SVivek Goyal } 1069d6eac039SVivek Goyal 1070d1e6f6a9SVivek Goyal int ovl_copy_up_with_data(struct dentry *dentry) 1071d1e6f6a9SVivek Goyal { 1072d1e6f6a9SVivek Goyal return ovl_copy_up_flags(dentry, O_WRONLY); 1073d1e6f6a9SVivek Goyal } 1074d1e6f6a9SVivek Goyal 10759aba6521SAmir Goldstein int ovl_copy_up(struct dentry *dentry) 10769aba6521SAmir Goldstein { 10779aba6521SAmir Goldstein return ovl_copy_up_flags(dentry, 0); 10789aba6521SAmir Goldstein } 1079