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struct kernel_param *param) 27fb5bb2c3SDavid Howells { 281bd0a3aeSlijiazi pr_warn("\"check_copy_up\" module option is obsolete\n"); 29fb5bb2c3SDavid Howells return 0; 30fb5bb2c3SDavid Howells } 31fb5bb2c3SDavid Howells 32670c2324SMiklos Szeredi static int ovl_ccup_get(char *buf, const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 47*2d343087SAl Viro int ovl_copy_xattr(struct super_block *sb, const struct path *oldpath, struct dentry *new) 48e9be9d5eSMiklos Szeredi { 49dad7017aSChristian Brauner struct dentry *old = oldpath->dentry; 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: 97dad7017aSChristian Brauner size = ovl_do_getxattr(oldpath, name, value, value_size); 98e4ad29faSVito Caputo if (size == -ERANGE) 99dad7017aSChristian Brauner size = ovl_do_getxattr(oldpath, 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 120c914c0e2SAmir Goldstein error = ovl_do_setxattr(OVL_FS(sb), 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 135*2d343087SAl Viro static int ovl_copy_fileattr(struct inode *inode, const struct path *old, 136*2d343087SAl Viro const 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); 1435b0a414dSMiklos Szeredi if (err) { 1445b0a414dSMiklos Szeredi /* Ntfs-3g returns -EINVAL for "no fileattr support" */ 1455b0a414dSMiklos Szeredi if (err == -ENOTTY || err == -EINVAL) 1465b0a414dSMiklos Szeredi return 0; 1475b0a414dSMiklos Szeredi pr_warn("failed to retrieve lower fileattr (%pd2, err=%i)\n", 1484ee7e4a6SChristoph Fritz old->dentry, err); 14972db8211SAmir Goldstein return err; 1505b0a414dSMiklos 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); 16094fd1975SMiklos Szeredi if (err == -EPERM) 16194fd1975SMiklos Szeredi pr_warn_once("copying fileattr: no xattr on upper\n"); 16294fd1975SMiklos Szeredi else if (err) 163096a218aSAmir Goldstein return err; 164096a218aSAmir Goldstein } 165096a218aSAmir Goldstein 1665b0a414dSMiklos Szeredi /* Don't bother copying flags if none are set */ 1675b0a414dSMiklos Szeredi if (!(oldfa.flags & OVL_COPY_FS_FLAGS_MASK)) 1685b0a414dSMiklos Szeredi return 0; 1695b0a414dSMiklos Szeredi 1705b0a414dSMiklos Szeredi err = ovl_real_fileattr_get(new, &newfa); 1715b0a414dSMiklos Szeredi if (err) { 17294fd1975SMiklos Szeredi /* 17394fd1975SMiklos Szeredi * Returning an error if upper doesn't support fileattr will 17494fd1975SMiklos Szeredi * result in a regression, so revert to the old behavior. 17594fd1975SMiklos Szeredi */ 17694fd1975SMiklos Szeredi if (err == -ENOTTY || err == -EINVAL) { 17794fd1975SMiklos Szeredi pr_warn_once("copying fileattr: no support on upper\n"); 17894fd1975SMiklos Szeredi return 0; 17994fd1975SMiklos Szeredi } 1805b0a414dSMiklos Szeredi pr_warn("failed to retrieve upper fileattr (%pd2, err=%i)\n", 1814ee7e4a6SChristoph Fritz new->dentry, err); 1825b0a414dSMiklos Szeredi return err; 1835b0a414dSMiklos Szeredi } 1845b0a414dSMiklos Szeredi 18572db8211SAmir Goldstein BUILD_BUG_ON(OVL_COPY_FS_FLAGS_MASK & ~FS_COMMON_FL); 18672db8211SAmir Goldstein newfa.flags &= ~OVL_COPY_FS_FLAGS_MASK; 18772db8211SAmir Goldstein newfa.flags |= (oldfa.flags & OVL_COPY_FS_FLAGS_MASK); 18872db8211SAmir Goldstein 18972db8211SAmir Goldstein BUILD_BUG_ON(OVL_COPY_FSX_FLAGS_MASK & ~FS_XFLAG_COMMON); 19072db8211SAmir Goldstein newfa.fsx_xflags &= ~OVL_COPY_FSX_FLAGS_MASK; 19172db8211SAmir Goldstein newfa.fsx_xflags |= (oldfa.fsx_xflags & OVL_COPY_FSX_FLAGS_MASK); 19272db8211SAmir Goldstein 19372db8211SAmir Goldstein return ovl_real_fileattr_set(new, &newfa); 19472db8211SAmir Goldstein } 19572db8211SAmir Goldstein 196*2d343087SAl Viro static int ovl_copy_up_data(struct ovl_fs *ofs, const struct path *old, 197*2d343087SAl Viro const struct path *new, loff_t len) 198e9be9d5eSMiklos Szeredi { 199e9be9d5eSMiklos Szeredi struct file *old_file; 200e9be9d5eSMiklos Szeredi struct file *new_file; 201e9be9d5eSMiklos Szeredi loff_t old_pos = 0; 202e9be9d5eSMiklos Szeredi loff_t new_pos = 0; 20342ec3d4cSDarrick J. Wong loff_t cloned; 204b504c654SChengguang Xu loff_t data_pos = -1; 205b504c654SChengguang Xu loff_t hole_len; 206b504c654SChengguang Xu bool skip_hole = false; 207e9be9d5eSMiklos Szeredi int error = 0; 208e9be9d5eSMiklos Szeredi 209e9be9d5eSMiklos Szeredi if (len == 0) 210e9be9d5eSMiklos Szeredi return 0; 211e9be9d5eSMiklos Szeredi 2120480334fSDavid Howells old_file = ovl_path_open(old, O_LARGEFILE | O_RDONLY); 213e9be9d5eSMiklos Szeredi if (IS_ERR(old_file)) 214e9be9d5eSMiklos Szeredi return PTR_ERR(old_file); 215e9be9d5eSMiklos Szeredi 2160480334fSDavid Howells new_file = ovl_path_open(new, O_LARGEFILE | O_WRONLY); 217e9be9d5eSMiklos Szeredi if (IS_ERR(new_file)) { 218e9be9d5eSMiklos Szeredi error = PTR_ERR(new_file); 219e9be9d5eSMiklos Szeredi goto out_fput; 220e9be9d5eSMiklos Szeredi } 221e9be9d5eSMiklos Szeredi 2222ea98466SAmir Goldstein /* Try to use clone_file_range to clone up within the same fs */ 223452ce659SDarrick J. Wong cloned = do_clone_file_range(old_file, 0, new_file, 0, len, 0); 22442ec3d4cSDarrick J. Wong if (cloned == len) 2252ea98466SAmir Goldstein goto out; 2262ea98466SAmir Goldstein /* Couldn't clone, so now we try to copy the data */ 2272ea98466SAmir Goldstein 228b504c654SChengguang Xu /* Check if lower fs supports seek operation */ 2294e3299eaSJason A. Donenfeld if (old_file->f_mode & FMODE_LSEEK) 230b504c654SChengguang Xu skip_hole = true; 231b504c654SChengguang Xu 232e9be9d5eSMiklos Szeredi while (len) { 233e9be9d5eSMiklos Szeredi size_t this_len = OVL_COPY_UP_CHUNK_SIZE; 234e9be9d5eSMiklos Szeredi long bytes; 235e9be9d5eSMiklos Szeredi 236e9be9d5eSMiklos Szeredi if (len < this_len) 237e9be9d5eSMiklos Szeredi this_len = len; 238e9be9d5eSMiklos Szeredi 239e9be9d5eSMiklos Szeredi if (signal_pending_state(TASK_KILLABLE, current)) { 240e9be9d5eSMiklos Szeredi error = -EINTR; 241e9be9d5eSMiklos Szeredi break; 242e9be9d5eSMiklos Szeredi } 243e9be9d5eSMiklos Szeredi 244b504c654SChengguang Xu /* 245b504c654SChengguang Xu * Fill zero for hole will cost unnecessary disk space 246b504c654SChengguang Xu * and meanwhile slow down the copy-up speed, so we do 247b504c654SChengguang Xu * an optimization for hole during copy-up, it relies 248b504c654SChengguang Xu * on SEEK_DATA implementation in lower fs so if lower 249b504c654SChengguang Xu * fs does not support it, copy-up will behave as before. 250b504c654SChengguang Xu * 251b504c654SChengguang Xu * Detail logic of hole detection as below: 252b504c654SChengguang Xu * When we detect next data position is larger than current 253b504c654SChengguang Xu * position we will skip that hole, otherwise we copy 254b504c654SChengguang Xu * data in the size of OVL_COPY_UP_CHUNK_SIZE. Actually, 255b504c654SChengguang Xu * it may not recognize all kind of holes and sometimes 256b504c654SChengguang Xu * only skips partial of hole area. However, it will be 257b504c654SChengguang Xu * enough for most of the use cases. 258b504c654SChengguang Xu */ 259b504c654SChengguang Xu 260b504c654SChengguang Xu if (skip_hole && data_pos < old_pos) { 261b504c654SChengguang Xu data_pos = vfs_llseek(old_file, old_pos, SEEK_DATA); 262b504c654SChengguang Xu if (data_pos > old_pos) { 263b504c654SChengguang Xu hole_len = data_pos - old_pos; 264b504c654SChengguang Xu len -= hole_len; 265b504c654SChengguang Xu old_pos = new_pos = data_pos; 266b504c654SChengguang Xu continue; 267b504c654SChengguang Xu } else if (data_pos == -ENXIO) { 268b504c654SChengguang Xu break; 269b504c654SChengguang Xu } else if (data_pos < 0) { 270b504c654SChengguang Xu skip_hole = false; 271b504c654SChengguang Xu } 272b504c654SChengguang Xu } 273b504c654SChengguang Xu 274e9be9d5eSMiklos Szeredi bytes = do_splice_direct(old_file, &old_pos, 275e9be9d5eSMiklos Szeredi new_file, &new_pos, 276e9be9d5eSMiklos Szeredi this_len, SPLICE_F_MOVE); 277e9be9d5eSMiklos Szeredi if (bytes <= 0) { 278e9be9d5eSMiklos Szeredi error = bytes; 279e9be9d5eSMiklos Szeredi break; 280e9be9d5eSMiklos Szeredi } 281e9be9d5eSMiklos Szeredi WARN_ON(old_pos != new_pos); 282e9be9d5eSMiklos Szeredi 283e9be9d5eSMiklos Szeredi len -= bytes; 284e9be9d5eSMiklos Szeredi } 2852ea98466SAmir Goldstein out: 286c86243b0SVivek Goyal if (!error && ovl_should_sync(ofs)) 287641089c1SMiklos Szeredi error = vfs_fsync(new_file, 0); 288e9be9d5eSMiklos Szeredi fput(new_file); 289e9be9d5eSMiklos Szeredi out_fput: 290e9be9d5eSMiklos Szeredi fput(old_file); 291e9be9d5eSMiklos Szeredi return error; 292e9be9d5eSMiklos Szeredi } 293e9be9d5eSMiklos Szeredi 2945272eaf3SChristian Brauner static int ovl_set_size(struct ovl_fs *ofs, 2955272eaf3SChristian Brauner struct dentry *upperdentry, struct kstat *stat) 2960c288874SVivek Goyal { 2970c288874SVivek Goyal struct iattr attr = { 2980c288874SVivek Goyal .ia_valid = ATTR_SIZE, 2990c288874SVivek Goyal .ia_size = stat->size, 3000c288874SVivek Goyal }; 3010c288874SVivek Goyal 302a15506eaSChristian Brauner return ovl_do_notify_change(ofs, upperdentry, &attr); 3030c288874SVivek Goyal } 3040c288874SVivek Goyal 3055272eaf3SChristian Brauner static int ovl_set_timestamps(struct ovl_fs *ofs, struct dentry *upperdentry, 3065272eaf3SChristian Brauner struct kstat *stat) 307e9be9d5eSMiklos Szeredi { 308e9be9d5eSMiklos Szeredi struct iattr attr = { 309e9be9d5eSMiklos Szeredi .ia_valid = 310e9be9d5eSMiklos Szeredi ATTR_ATIME | ATTR_MTIME | ATTR_ATIME_SET | ATTR_MTIME_SET, 311e9be9d5eSMiklos Szeredi .ia_atime = stat->atime, 312e9be9d5eSMiklos Szeredi .ia_mtime = stat->mtime, 313e9be9d5eSMiklos Szeredi }; 314e9be9d5eSMiklos Szeredi 315a15506eaSChristian Brauner return ovl_do_notify_change(ofs, upperdentry, &attr); 316e9be9d5eSMiklos Szeredi } 317e9be9d5eSMiklos Szeredi 3185272eaf3SChristian Brauner int ovl_set_attr(struct ovl_fs *ofs, struct dentry *upperdentry, 3195272eaf3SChristian Brauner struct kstat *stat) 320e9be9d5eSMiklos Szeredi { 321e9be9d5eSMiklos Szeredi int err = 0; 322e9be9d5eSMiklos Szeredi 323e9be9d5eSMiklos Szeredi if (!S_ISLNK(stat->mode)) { 324e9be9d5eSMiklos Szeredi struct iattr attr = { 325e9be9d5eSMiklos Szeredi .ia_valid = ATTR_MODE, 326e9be9d5eSMiklos Szeredi .ia_mode = stat->mode, 327e9be9d5eSMiklos Szeredi }; 328a15506eaSChristian Brauner err = ovl_do_notify_change(ofs, upperdentry, &attr); 329e9be9d5eSMiklos Szeredi } 330e9be9d5eSMiklos Szeredi if (!err) { 331e9be9d5eSMiklos Szeredi struct iattr attr = { 332e9be9d5eSMiklos Szeredi .ia_valid = ATTR_UID | ATTR_GID, 333b27c82e1SChristian Brauner .ia_vfsuid = VFSUIDT_INIT(stat->uid), 334b27c82e1SChristian Brauner .ia_vfsgid = VFSGIDT_INIT(stat->gid), 335e9be9d5eSMiklos Szeredi }; 336a15506eaSChristian Brauner err = ovl_do_notify_change(ofs, upperdentry, &attr); 337e9be9d5eSMiklos Szeredi } 338e9be9d5eSMiklos Szeredi if (!err) 3395272eaf3SChristian Brauner ovl_set_timestamps(ofs, upperdentry, stat); 340e9be9d5eSMiklos Szeredi 341e9be9d5eSMiklos Szeredi return err; 342e9be9d5eSMiklos Szeredi } 343e9be9d5eSMiklos Szeredi 3441cdb0cb6SPavel Tikhomirov struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real, 3451cdb0cb6SPavel Tikhomirov bool is_upper) 3463a1e819bSAmir Goldstein { 3473a1e819bSAmir Goldstein struct ovl_fh *fh; 348ec7bbb53SAmir Goldstein int fh_type, dwords; 3493a1e819bSAmir Goldstein int buflen = MAX_HANDLE_SZ; 35005122443SAmir Goldstein uuid_t *uuid = &real->d_sb->s_uuid; 351ec7bbb53SAmir Goldstein int err; 3523a1e819bSAmir Goldstein 353ec7bbb53SAmir Goldstein /* Make sure the real fid stays 32bit aligned */ 354ec7bbb53SAmir Goldstein BUILD_BUG_ON(OVL_FH_FID_OFFSET % 4); 355ec7bbb53SAmir Goldstein BUILD_BUG_ON(MAX_HANDLE_SZ + OVL_FH_FID_OFFSET > 255); 356ec7bbb53SAmir Goldstein 357ec7bbb53SAmir Goldstein fh = kzalloc(buflen + OVL_FH_FID_OFFSET, GFP_KERNEL); 358ec7bbb53SAmir Goldstein if (!fh) 3593a1e819bSAmir Goldstein return ERR_PTR(-ENOMEM); 3603a1e819bSAmir Goldstein 3613a1e819bSAmir Goldstein /* 3623a1e819bSAmir Goldstein * We encode a non-connectable file handle for non-dir, because we 3633a1e819bSAmir Goldstein * only need to find the lower inode number and we don't want to pay 3643a1e819bSAmir Goldstein * the price or reconnecting the dentry. 3653a1e819bSAmir Goldstein */ 3663a1e819bSAmir Goldstein dwords = buflen >> 2; 367ec7bbb53SAmir Goldstein fh_type = exportfs_encode_fh(real, (void *)fh->fb.fid, &dwords, 0); 3683a1e819bSAmir Goldstein buflen = (dwords << 2); 3693a1e819bSAmir Goldstein 370ec7bbb53SAmir Goldstein err = -EIO; 3713a1e819bSAmir Goldstein if (WARN_ON(fh_type < 0) || 3723a1e819bSAmir Goldstein WARN_ON(buflen > MAX_HANDLE_SZ) || 3733a1e819bSAmir Goldstein WARN_ON(fh_type == FILEID_INVALID)) 374ec7bbb53SAmir Goldstein goto out_err; 3753a1e819bSAmir Goldstein 376cbe7fba8SAmir Goldstein fh->fb.version = OVL_FH_VERSION; 377cbe7fba8SAmir Goldstein fh->fb.magic = OVL_FH_MAGIC; 378cbe7fba8SAmir Goldstein fh->fb.type = fh_type; 379cbe7fba8SAmir Goldstein fh->fb.flags = OVL_FH_FLAG_CPU_ENDIAN; 38054fb347eSAmir Goldstein /* 38154fb347eSAmir Goldstein * When we will want to decode an overlay dentry from this handle 38254fb347eSAmir Goldstein * and all layers are on the same fs, if we get a disconncted real 38354fb347eSAmir Goldstein * dentry when we decode fid, the only way to tell if we should assign 38454fb347eSAmir Goldstein * it to upperdentry or to lowerstack is by checking this flag. 38554fb347eSAmir Goldstein */ 38654fb347eSAmir Goldstein if (is_upper) 387cbe7fba8SAmir Goldstein fh->fb.flags |= OVL_FH_FLAG_PATH_UPPER; 388ec7bbb53SAmir Goldstein fh->fb.len = sizeof(fh->fb) + buflen; 3895830fb6bSPavel Tikhomirov if (ofs->config.uuid) 390cbe7fba8SAmir Goldstein fh->fb.uuid = *uuid; 3913a1e819bSAmir Goldstein 3923a1e819bSAmir Goldstein return fh; 393ec7bbb53SAmir Goldstein 394ec7bbb53SAmir Goldstein out_err: 395ec7bbb53SAmir Goldstein kfree(fh); 396ec7bbb53SAmir Goldstein return ERR_PTR(err); 3973a1e819bSAmir Goldstein } 3983a1e819bSAmir Goldstein 399a0c236b1SAmir Goldstein int ovl_set_origin(struct ovl_fs *ofs, struct dentry *lower, 400a0c236b1SAmir Goldstein struct dentry *upper) 4013a1e819bSAmir Goldstein { 4023a1e819bSAmir Goldstein const struct ovl_fh *fh = NULL; 4033a1e819bSAmir Goldstein int err; 4043a1e819bSAmir Goldstein 4053a1e819bSAmir Goldstein /* 4063a1e819bSAmir Goldstein * When lower layer doesn't support export operations store a 'null' fh, 4073a1e819bSAmir Goldstein * so we can use the overlay.origin xattr to distignuish between a copy 4083a1e819bSAmir Goldstein * up and a pure upper inode. 4093a1e819bSAmir Goldstein */ 41002bcd157SAmir Goldstein if (ovl_can_decode_fh(lower->d_sb)) { 4111cdb0cb6SPavel Tikhomirov fh = ovl_encode_real_fh(ofs, lower, false); 4123a1e819bSAmir Goldstein if (IS_ERR(fh)) 4133a1e819bSAmir Goldstein return PTR_ERR(fh); 4143a1e819bSAmir Goldstein } 4153a1e819bSAmir Goldstein 4166266d465SMiklos Szeredi /* 4176266d465SMiklos Szeredi * Do not fail when upper doesn't support xattrs. 4186266d465SMiklos Szeredi */ 419a0c236b1SAmir Goldstein err = ovl_check_setxattr(ofs, upper, OVL_XATTR_ORIGIN, fh->buf, 420cbe7fba8SAmir Goldstein fh ? fh->fb.len : 0, 0); 4213a1e819bSAmir Goldstein kfree(fh); 4223a1e819bSAmir Goldstein 4236939f977SMiklos Szeredi /* Ignore -EPERM from setting "user.*" on symlink/special */ 4246939f977SMiklos Szeredi return err == -EPERM ? 0 : err; 4253a1e819bSAmir Goldstein } 4263a1e819bSAmir Goldstein 427016b720fSAmir Goldstein /* Store file handle of @upper dir in @index dir entry */ 428610afc0bSMiklos Szeredi static int ovl_set_upper_fh(struct ovl_fs *ofs, struct dentry *upper, 429610afc0bSMiklos Szeredi struct dentry *index) 430016b720fSAmir Goldstein { 431016b720fSAmir Goldstein const struct ovl_fh *fh; 432016b720fSAmir Goldstein int err; 433016b720fSAmir Goldstein 4341cdb0cb6SPavel Tikhomirov fh = ovl_encode_real_fh(ofs, upper, true); 435016b720fSAmir Goldstein if (IS_ERR(fh)) 436016b720fSAmir Goldstein return PTR_ERR(fh); 437016b720fSAmir Goldstein 438c914c0e2SAmir Goldstein err = ovl_setxattr(ofs, index, OVL_XATTR_UPPER, fh->buf, fh->fb.len); 439016b720fSAmir Goldstein 440016b720fSAmir Goldstein kfree(fh); 441016b720fSAmir Goldstein return err; 442016b720fSAmir Goldstein } 443016b720fSAmir Goldstein 444016b720fSAmir Goldstein /* 445016b720fSAmir Goldstein * Create and install index entry. 446016b720fSAmir Goldstein * 447016b720fSAmir Goldstein * Caller must hold i_mutex on indexdir. 448016b720fSAmir Goldstein */ 449016b720fSAmir Goldstein static int ovl_create_index(struct dentry *dentry, struct dentry *origin, 450016b720fSAmir Goldstein struct dentry *upper) 451016b720fSAmir Goldstein { 4521cdb0cb6SPavel Tikhomirov struct ovl_fs *ofs = OVL_FS(dentry->d_sb); 453016b720fSAmir Goldstein struct dentry *indexdir = ovl_indexdir(dentry->d_sb); 454016b720fSAmir Goldstein struct inode *dir = d_inode(indexdir); 455016b720fSAmir Goldstein struct dentry *index = NULL; 456016b720fSAmir Goldstein struct dentry *temp = NULL; 457016b720fSAmir Goldstein struct qstr name = { }; 458016b720fSAmir Goldstein int err; 459016b720fSAmir Goldstein 460016b720fSAmir Goldstein /* 461016b720fSAmir Goldstein * For now this is only used for creating index entry for directories, 462016b720fSAmir Goldstein * because non-dir are copied up directly to index and then hardlinked 463016b720fSAmir Goldstein * to upper dir. 464016b720fSAmir Goldstein * 465016b720fSAmir Goldstein * TODO: implement create index for non-dir, so we can call it when 466016b720fSAmir Goldstein * encoding file handle for non-dir in case index does not exist. 467016b720fSAmir Goldstein */ 468016b720fSAmir Goldstein if (WARN_ON(!d_is_dir(dentry))) 469016b720fSAmir Goldstein return -EIO; 470016b720fSAmir Goldstein 471016b720fSAmir Goldstein /* Directory not expected to be indexed before copy up */ 472016b720fSAmir Goldstein if (WARN_ON(ovl_test_flag(OVL_INDEX, d_inode(dentry)))) 473016b720fSAmir Goldstein return -EIO; 474016b720fSAmir Goldstein 4751cdb0cb6SPavel Tikhomirov err = ovl_get_index_name(ofs, origin, &name); 476016b720fSAmir Goldstein if (err) 477016b720fSAmir Goldstein return err; 478016b720fSAmir Goldstein 479576bb263SChristian Brauner temp = ovl_create_temp(ofs, indexdir, OVL_CATTR(S_IFDIR | 0)); 480b148cba4SMiklos Szeredi err = PTR_ERR(temp); 481016b720fSAmir Goldstein if (IS_ERR(temp)) 482b148cba4SMiklos Szeredi goto free_name; 483016b720fSAmir Goldstein 4841cdb0cb6SPavel Tikhomirov err = ovl_set_upper_fh(ofs, upper, temp); 485016b720fSAmir Goldstein if (err) 486b148cba4SMiklos Szeredi goto out; 487016b720fSAmir Goldstein 48822f289ceSChristian Brauner index = ovl_lookup_upper(ofs, name.name, indexdir, name.len); 489016b720fSAmir Goldstein if (IS_ERR(index)) { 490016b720fSAmir Goldstein err = PTR_ERR(index); 491016b720fSAmir Goldstein } else { 492576bb263SChristian Brauner err = ovl_do_rename(ofs, dir, temp, dir, index, 0); 493016b720fSAmir Goldstein dput(index); 494016b720fSAmir Goldstein } 495016b720fSAmir Goldstein out: 496b148cba4SMiklos Szeredi if (err) 497576bb263SChristian Brauner ovl_cleanup(ofs, dir, temp); 498016b720fSAmir Goldstein dput(temp); 499b148cba4SMiklos Szeredi free_name: 500016b720fSAmir Goldstein kfree(name.name); 501016b720fSAmir Goldstein return err; 502016b720fSAmir Goldstein } 503016b720fSAmir Goldstein 50423f0ab13SMiklos Szeredi struct ovl_copy_up_ctx { 505a6fb235aSMiklos Szeredi struct dentry *parent; 50623f0ab13SMiklos Szeredi struct dentry *dentry; 50723f0ab13SMiklos Szeredi struct path lowerpath; 50823f0ab13SMiklos Szeredi struct kstat stat; 50923f0ab13SMiklos Szeredi struct kstat pstat; 51023f0ab13SMiklos Szeredi const char *link; 51159be0971SAmir Goldstein struct dentry *destdir; 51259be0971SAmir Goldstein struct qstr destname; 51323f0ab13SMiklos Szeredi struct dentry *workdir; 51459be0971SAmir Goldstein bool origin; 515016b720fSAmir Goldstein bool indexed; 51644d5bf10SVivek Goyal bool metacopy; 51723f0ab13SMiklos Szeredi }; 51823f0ab13SMiklos Szeredi 519f4439de1SAmir Goldstein static int ovl_link_up(struct ovl_copy_up_ctx *c) 520f4439de1SAmir Goldstein { 521f4439de1SAmir Goldstein int err; 522f4439de1SAmir Goldstein struct dentry *upper; 523f4439de1SAmir Goldstein struct dentry *upperdir = ovl_dentry_upper(c->parent); 524576bb263SChristian Brauner struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); 525f4439de1SAmir Goldstein struct inode *udir = d_inode(upperdir); 526f4439de1SAmir Goldstein 527f4439de1SAmir Goldstein /* Mark parent "impure" because it may now contain non-pure upper */ 528f4439de1SAmir Goldstein err = ovl_set_impure(c->parent, upperdir); 529f4439de1SAmir Goldstein if (err) 530f4439de1SAmir Goldstein return err; 531f4439de1SAmir Goldstein 532f4439de1SAmir Goldstein err = ovl_set_nlink_lower(c->dentry); 533f4439de1SAmir Goldstein if (err) 534f4439de1SAmir Goldstein return err; 535f4439de1SAmir Goldstein 536f4439de1SAmir Goldstein inode_lock_nested(udir, I_MUTEX_PARENT); 53722f289ceSChristian Brauner upper = ovl_lookup_upper(ofs, c->dentry->d_name.name, upperdir, 538f4439de1SAmir Goldstein c->dentry->d_name.len); 539f4439de1SAmir Goldstein err = PTR_ERR(upper); 540f4439de1SAmir Goldstein if (!IS_ERR(upper)) { 541576bb263SChristian Brauner err = ovl_do_link(ofs, ovl_dentry_upper(c->dentry), udir, upper); 542f4439de1SAmir Goldstein dput(upper); 543f4439de1SAmir Goldstein 544f4439de1SAmir Goldstein if (!err) { 545f4439de1SAmir Goldstein /* Restore timestamps on parent (best effort) */ 5465272eaf3SChristian Brauner ovl_set_timestamps(ofs, upperdir, &c->pstat); 547f4439de1SAmir Goldstein ovl_dentry_set_upper_alias(c->dentry); 548f4439de1SAmir Goldstein } 549f4439de1SAmir Goldstein } 550f4439de1SAmir Goldstein inode_unlock(udir); 551aa3ff3c1SAmir Goldstein if (err) 552aa3ff3c1SAmir Goldstein return err; 553aa3ff3c1SAmir Goldstein 554aa3ff3c1SAmir Goldstein err = ovl_set_nlink_upper(c->dentry); 555f4439de1SAmir Goldstein 556f4439de1SAmir Goldstein return err; 557f4439de1SAmir Goldstein } 558f4439de1SAmir Goldstein 55923f0ab13SMiklos Szeredi static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp) 56002209d10SAmir Goldstein { 561c86243b0SVivek Goyal struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); 56272db8211SAmir Goldstein struct inode *inode = d_inode(c->dentry); 56372db8211SAmir Goldstein struct path upperpath, datapath; 56402209d10SAmir Goldstein int err; 56502209d10SAmir Goldstein 56672db8211SAmir Goldstein ovl_path_upper(c->dentry, &upperpath); 56772db8211SAmir Goldstein if (WARN_ON(upperpath.dentry != NULL)) 56872db8211SAmir Goldstein return -EIO; 56972db8211SAmir Goldstein 57072db8211SAmir Goldstein upperpath.dentry = temp; 57172db8211SAmir Goldstein 5725f32879eSVivek Goyal /* 5735f32879eSVivek Goyal * Copy up data first and then xattrs. Writing data after 5745f32879eSVivek Goyal * xattrs will remove security.capability xattr automatically. 5755f32879eSVivek Goyal */ 5765f32879eSVivek Goyal if (S_ISREG(c->stat.mode) && !c->metacopy) { 5775f32879eSVivek Goyal ovl_path_lowerdata(c->dentry, &datapath); 578c86243b0SVivek Goyal err = ovl_copy_up_data(ofs, &datapath, &upperpath, 579c86243b0SVivek Goyal c->stat.size); 5805f32879eSVivek Goyal if (err) 5815f32879eSVivek Goyal return err; 5825f32879eSVivek Goyal } 5835f32879eSVivek Goyal 584dad7017aSChristian Brauner err = ovl_copy_xattr(c->dentry->d_sb, &c->lowerpath, temp); 58502209d10SAmir Goldstein if (err) 58602209d10SAmir Goldstein return err; 58702209d10SAmir Goldstein 58872db8211SAmir Goldstein if (inode->i_flags & OVL_COPY_I_FLAGS_MASK) { 58972db8211SAmir Goldstein /* 59072db8211SAmir Goldstein * Copy the fileattr inode flags that are the source of already 59172db8211SAmir Goldstein * copied i_flags 59272db8211SAmir Goldstein */ 593096a218aSAmir Goldstein err = ovl_copy_fileattr(inode, &c->lowerpath, &upperpath); 59472db8211SAmir Goldstein if (err) 59572db8211SAmir Goldstein return err; 59672db8211SAmir Goldstein } 59772db8211SAmir Goldstein 59802209d10SAmir Goldstein /* 59902209d10SAmir Goldstein * Store identifier of lower inode in upper inode xattr to 60002209d10SAmir Goldstein * allow lookup of the copy up origin inode. 60102209d10SAmir Goldstein * 60202209d10SAmir Goldstein * Don't set origin when we are breaking the association with a lower 60302209d10SAmir Goldstein * hard link. 60402209d10SAmir Goldstein */ 60559be0971SAmir Goldstein if (c->origin) { 606a0c236b1SAmir Goldstein err = ovl_set_origin(ofs, c->lowerpath.dentry, temp); 60702209d10SAmir Goldstein if (err) 60802209d10SAmir Goldstein return err; 60902209d10SAmir Goldstein } 61002209d10SAmir Goldstein 6110c288874SVivek Goyal if (c->metacopy) { 612a0c236b1SAmir Goldstein err = ovl_check_setxattr(ofs, temp, OVL_XATTR_METACOPY, 6130c288874SVivek Goyal NULL, 0, -EOPNOTSUPP); 6140c288874SVivek Goyal if (err) 6150c288874SVivek Goyal return err; 6160c288874SVivek Goyal } 6170c288874SVivek Goyal 618bd64e575SVivek Goyal inode_lock(temp->d_inode); 619b504c654SChengguang Xu if (S_ISREG(c->stat.mode)) 6205272eaf3SChristian Brauner err = ovl_set_size(ofs, temp, &c->stat); 6210c288874SVivek Goyal if (!err) 6225272eaf3SChristian Brauner err = ovl_set_attr(ofs, temp, &c->stat); 623bd64e575SVivek Goyal inode_unlock(temp->d_inode); 624bd64e575SVivek Goyal 625bd64e575SVivek Goyal return err; 62602209d10SAmir Goldstein } 62702209d10SAmir Goldstein 6286b52243fSMiklos Szeredi struct ovl_cu_creds { 6296b52243fSMiklos Szeredi const struct cred *old; 6306b52243fSMiklos Szeredi struct cred *new; 631b10cdcdcSAmir Goldstein }; 632b10cdcdcSAmir Goldstein 6336b52243fSMiklos Szeredi static int ovl_prep_cu_creds(struct dentry *dentry, struct ovl_cu_creds *cc) 634b10cdcdcSAmir Goldstein { 635b10cdcdcSAmir Goldstein int err; 636b10cdcdcSAmir Goldstein 6376b52243fSMiklos Szeredi cc->old = cc->new = NULL; 6386b52243fSMiklos Szeredi err = security_inode_copy_up(dentry, &cc->new); 6396b52243fSMiklos Szeredi if (err < 0) 640b10cdcdcSAmir Goldstein return err; 6416b52243fSMiklos Szeredi 6426b52243fSMiklos Szeredi if (cc->new) 6436b52243fSMiklos Szeredi cc->old = override_creds(cc->new); 6446b52243fSMiklos Szeredi 6456b52243fSMiklos Szeredi return 0; 6466b52243fSMiklos Szeredi } 6476b52243fSMiklos Szeredi 6486b52243fSMiklos Szeredi static void ovl_revert_cu_creds(struct ovl_cu_creds *cc) 6496b52243fSMiklos Szeredi { 6506b52243fSMiklos Szeredi if (cc->new) { 6516b52243fSMiklos Szeredi revert_creds(cc->old); 6526b52243fSMiklos Szeredi put_cred(cc->new); 6536b52243fSMiklos Szeredi } 654b10cdcdcSAmir Goldstein } 655b10cdcdcSAmir Goldstein 656b10cdcdcSAmir Goldstein /* 657b10cdcdcSAmir Goldstein * Copyup using workdir to prepare temp file. Used when copying up directories, 658b10cdcdcSAmir Goldstein * special files or when upper fs doesn't support O_TMPFILE. 659b10cdcdcSAmir Goldstein */ 660b10cdcdcSAmir Goldstein static int ovl_copy_up_workdir(struct ovl_copy_up_ctx *c) 661b10cdcdcSAmir Goldstein { 662576bb263SChristian Brauner struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); 663b79e05aaSAmir Goldstein struct inode *inode; 6646b52243fSMiklos Szeredi struct inode *udir = d_inode(c->destdir), *wdir = d_inode(c->workdir); 6656b52243fSMiklos Szeredi struct dentry *temp, *upper; 6666b52243fSMiklos Szeredi struct ovl_cu_creds cc; 6677d90b853SMiklos Szeredi int err; 6686b52243fSMiklos Szeredi struct ovl_cattr cattr = { 6696b52243fSMiklos Szeredi /* Can't properly set mode on creation because of the umask */ 6706b52243fSMiklos Szeredi .mode = c->stat.mode & S_IFMT, 6716b52243fSMiklos Szeredi .rdev = c->stat.rdev, 6726b52243fSMiklos Szeredi .link = c->link 6736b52243fSMiklos Szeredi }; 6747d90b853SMiklos Szeredi 675773cb4c5SAmir Goldstein /* workdir and destdir could be the same when copying up to indexdir */ 676773cb4c5SAmir Goldstein err = -EIO; 677773cb4c5SAmir Goldstein if (lock_rename(c->workdir, c->destdir) != NULL) 678773cb4c5SAmir Goldstein goto unlock; 679b10cdcdcSAmir Goldstein 6806b52243fSMiklos Szeredi err = ovl_prep_cu_creds(c->dentry, &cc); 6816b52243fSMiklos Szeredi if (err) 6826b52243fSMiklos Szeredi goto unlock; 6836b52243fSMiklos Szeredi 684576bb263SChristian Brauner temp = ovl_create_temp(ofs, c->workdir, &cattr); 6856b52243fSMiklos Szeredi ovl_revert_cu_creds(&cc); 6866b52243fSMiklos Szeredi 687b10cdcdcSAmir Goldstein err = PTR_ERR(temp); 688b10cdcdcSAmir Goldstein if (IS_ERR(temp)) 689b10cdcdcSAmir Goldstein goto unlock; 690b10cdcdcSAmir Goldstein 691b10cdcdcSAmir Goldstein err = ovl_copy_up_inode(c, temp); 692b10cdcdcSAmir Goldstein if (err) 693b10cdcdcSAmir Goldstein goto cleanup; 694b10cdcdcSAmir Goldstein 695b10cdcdcSAmir Goldstein if (S_ISDIR(c->stat.mode) && c->indexed) { 696b10cdcdcSAmir Goldstein err = ovl_create_index(c->dentry, c->lowerpath.dentry, temp); 697b10cdcdcSAmir Goldstein if (err) 698b10cdcdcSAmir Goldstein goto cleanup; 699b10cdcdcSAmir Goldstein } 700b10cdcdcSAmir Goldstein 70122f289ceSChristian Brauner upper = ovl_lookup_upper(ofs, c->destname.name, c->destdir, 70222f289ceSChristian Brauner c->destname.len); 7036b52243fSMiklos Szeredi err = PTR_ERR(upper); 7046b52243fSMiklos Szeredi if (IS_ERR(upper)) 7056b52243fSMiklos Szeredi goto cleanup; 7066b52243fSMiklos Szeredi 707576bb263SChristian Brauner err = ovl_do_rename(ofs, wdir, temp, udir, upper, 0); 7086b52243fSMiklos Szeredi dput(upper); 709b10cdcdcSAmir Goldstein if (err) 710b10cdcdcSAmir Goldstein goto cleanup; 711b10cdcdcSAmir Goldstein 712b10cdcdcSAmir Goldstein if (!c->metacopy) 713b10cdcdcSAmir Goldstein ovl_set_upperdata(d_inode(c->dentry)); 714b10cdcdcSAmir Goldstein inode = d_inode(c->dentry); 7156b52243fSMiklos Szeredi ovl_inode_update(inode, temp); 716b10cdcdcSAmir Goldstein if (S_ISDIR(inode->i_mode)) 717b10cdcdcSAmir Goldstein ovl_set_flag(OVL_WHITEOUTS, inode); 718b10cdcdcSAmir Goldstein unlock: 719b10cdcdcSAmir Goldstein unlock_rename(c->workdir, c->destdir); 720b10cdcdcSAmir Goldstein 721b10cdcdcSAmir Goldstein return err; 722b10cdcdcSAmir Goldstein 723b10cdcdcSAmir Goldstein cleanup: 724576bb263SChristian Brauner ovl_cleanup(ofs, wdir, temp); 7256b52243fSMiklos Szeredi dput(temp); 726b10cdcdcSAmir Goldstein goto unlock; 727b10cdcdcSAmir Goldstein } 728b10cdcdcSAmir Goldstein 729b10cdcdcSAmir Goldstein /* Copyup using O_TMPFILE which does not require cross dir locking */ 730b10cdcdcSAmir Goldstein static int ovl_copy_up_tmpfile(struct ovl_copy_up_ctx *c) 731b10cdcdcSAmir Goldstein { 732576bb263SChristian Brauner struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); 7336b52243fSMiklos Szeredi struct inode *udir = d_inode(c->destdir); 7346b52243fSMiklos Szeredi struct dentry *temp, *upper; 7356b52243fSMiklos Szeredi struct ovl_cu_creds cc; 736b10cdcdcSAmir Goldstein int err; 737b10cdcdcSAmir Goldstein 7386b52243fSMiklos Szeredi err = ovl_prep_cu_creds(c->dentry, &cc); 7396b52243fSMiklos Szeredi if (err) 7406b52243fSMiklos Szeredi return err; 7416b52243fSMiklos Szeredi 742576bb263SChristian Brauner temp = ovl_do_tmpfile(ofs, c->workdir, c->stat.mode); 7436b52243fSMiklos Szeredi ovl_revert_cu_creds(&cc); 7446b52243fSMiklos Szeredi 745b148cba4SMiklos Szeredi if (IS_ERR(temp)) 746b148cba4SMiklos Szeredi return PTR_ERR(temp); 747e9be9d5eSMiklos Szeredi 74823f0ab13SMiklos Szeredi err = ovl_copy_up_inode(c, temp); 749e9be9d5eSMiklos Szeredi if (err) 7506b52243fSMiklos Szeredi goto out_dput; 7513a1e819bSAmir Goldstein 7526b52243fSMiklos Szeredi inode_lock_nested(udir, I_MUTEX_PARENT); 7536b52243fSMiklos Szeredi 75422f289ceSChristian Brauner upper = ovl_lookup_upper(ofs, c->destname.name, c->destdir, 75522f289ceSChristian Brauner c->destname.len); 7566b52243fSMiklos Szeredi err = PTR_ERR(upper); 7576b52243fSMiklos Szeredi if (!IS_ERR(upper)) { 758576bb263SChristian Brauner err = ovl_do_link(ofs, temp, udir, upper); 7596b52243fSMiklos Szeredi dput(upper); 7606b52243fSMiklos Szeredi } 7616b52243fSMiklos Szeredi inode_unlock(udir); 7626b52243fSMiklos Szeredi 763e9be9d5eSMiklos Szeredi if (err) 7646b52243fSMiklos Szeredi goto out_dput; 765e9be9d5eSMiklos Szeredi 7660c288874SVivek Goyal if (!c->metacopy) 7670c288874SVivek Goyal ovl_set_upperdata(d_inode(c->dentry)); 7686b52243fSMiklos Szeredi ovl_inode_update(d_inode(c->dentry), temp); 769b79e05aaSAmir Goldstein 7706b52243fSMiklos Szeredi return 0; 7716b52243fSMiklos Szeredi 7726b52243fSMiklos Szeredi out_dput: 773e85f82ffSMiklos Szeredi dput(temp); 774e9be9d5eSMiklos Szeredi return err; 775e9be9d5eSMiklos Szeredi } 776e9be9d5eSMiklos Szeredi 777e9be9d5eSMiklos Szeredi /* 778e9be9d5eSMiklos Szeredi * Copy up a single dentry 779e9be9d5eSMiklos Szeredi * 780a6c60655SMiklos Szeredi * All renames start with copy up of source if necessary. The actual 781a6c60655SMiklos Szeredi * rename will only proceed once the copy up was successful. Copy up uses 782a6c60655SMiklos Szeredi * upper parent i_mutex for exclusion. Since rename can change d_parent it 783a6c60655SMiklos Szeredi * is possible that the copy up will lock the old parent. At that point 784a6c60655SMiklos Szeredi * the file will have already been copied up anyway. 785e9be9d5eSMiklos Szeredi */ 786a6fb235aSMiklos Szeredi static int ovl_do_copy_up(struct ovl_copy_up_ctx *c) 787e9be9d5eSMiklos Szeredi { 788e9be9d5eSMiklos Szeredi int err; 7891cdb0cb6SPavel Tikhomirov struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); 790016b720fSAmir Goldstein bool to_index = false; 79159be0971SAmir Goldstein 792016b720fSAmir Goldstein /* 793016b720fSAmir Goldstein * Indexed non-dir is copied up directly to the index entry and then 794016b720fSAmir Goldstein * hardlinked to upper dir. Indexed dir is copied up to indexdir, 795016b720fSAmir Goldstein * then index entry is created and then copied up dir installed. 796016b720fSAmir Goldstein * Copying dir up to indexdir instead of workdir simplifies locking. 797016b720fSAmir Goldstein */ 798016b720fSAmir Goldstein if (ovl_need_index(c->dentry)) { 799016b720fSAmir Goldstein c->indexed = true; 800016b720fSAmir Goldstein if (S_ISDIR(c->stat.mode)) 801016b720fSAmir Goldstein c->workdir = ovl_indexdir(c->dentry->d_sb); 802016b720fSAmir Goldstein else 803016b720fSAmir Goldstein to_index = true; 804016b720fSAmir Goldstein } 805016b720fSAmir Goldstein 806016b720fSAmir Goldstein if (S_ISDIR(c->stat.mode) || c->stat.nlink == 1 || to_index) 80759be0971SAmir Goldstein c->origin = true; 80859be0971SAmir Goldstein 809016b720fSAmir Goldstein if (to_index) { 81059be0971SAmir Goldstein c->destdir = ovl_indexdir(c->dentry->d_sb); 8111cdb0cb6SPavel Tikhomirov err = ovl_get_index_name(ofs, c->lowerpath.dentry, &c->destname); 812f3a15685SAmir Goldstein if (err) 813f3a15685SAmir Goldstein return err; 814aa3ff3c1SAmir Goldstein } else if (WARN_ON(!c->parent)) { 815aa3ff3c1SAmir Goldstein /* Disconnected dentry must be copied up to index dir */ 816aa3ff3c1SAmir Goldstein return -EIO; 81759be0971SAmir Goldstein } else { 81859be0971SAmir Goldstein /* 81959be0971SAmir Goldstein * Mark parent "impure" because it may now contain non-pure 82059be0971SAmir Goldstein * upper 82159be0971SAmir Goldstein */ 82259be0971SAmir Goldstein err = ovl_set_impure(c->parent, c->destdir); 82359be0971SAmir Goldstein if (err) 82459be0971SAmir Goldstein return err; 82559be0971SAmir Goldstein } 826f3a15685SAmir Goldstein 82701ad3eb8SAmir Goldstein /* Should we copyup with O_TMPFILE or with workdir? */ 828b10cdcdcSAmir Goldstein if (S_ISREG(c->stat.mode) && ofs->tmpfile) 829b10cdcdcSAmir Goldstein err = ovl_copy_up_tmpfile(c); 830b10cdcdcSAmir Goldstein else 831b10cdcdcSAmir Goldstein err = ovl_copy_up_workdir(c); 832aa3ff3c1SAmir Goldstein if (err) 833aa3ff3c1SAmir Goldstein goto out; 834aa3ff3c1SAmir Goldstein 835aa3ff3c1SAmir Goldstein if (c->indexed) 83659be0971SAmir Goldstein ovl_set_flag(OVL_INDEX, d_inode(c->dentry)); 837016b720fSAmir Goldstein 838016b720fSAmir Goldstein if (to_index) { 839aa3ff3c1SAmir Goldstein /* Initialize nlink for copy up of disconnected dentry */ 840aa3ff3c1SAmir Goldstein err = ovl_set_nlink_upper(c->dentry); 841aa3ff3c1SAmir Goldstein } else { 84259be0971SAmir Goldstein struct inode *udir = d_inode(c->destdir); 84359be0971SAmir Goldstein 84459be0971SAmir Goldstein /* Restore timestamps on parent (best effort) */ 84559be0971SAmir Goldstein inode_lock(udir); 8465272eaf3SChristian Brauner ovl_set_timestamps(ofs, c->destdir, &c->pstat); 84759be0971SAmir Goldstein inode_unlock(udir); 84859be0971SAmir Goldstein 84959be0971SAmir Goldstein ovl_dentry_set_upper_alias(c->dentry); 850fd210b7dSMiklos Szeredi } 851a6fb235aSMiklos Szeredi 852aa3ff3c1SAmir Goldstein out: 853aa3ff3c1SAmir Goldstein if (to_index) 854aa3ff3c1SAmir Goldstein kfree(c->destname.name); 855a6fb235aSMiklos Szeredi return err; 856a6fb235aSMiklos Szeredi } 857a6fb235aSMiklos Szeredi 85844d5bf10SVivek Goyal static bool ovl_need_meta_copy_up(struct dentry *dentry, umode_t mode, 85944d5bf10SVivek Goyal int flags) 86044d5bf10SVivek Goyal { 86144d5bf10SVivek Goyal struct ovl_fs *ofs = dentry->d_sb->s_fs_info; 86244d5bf10SVivek Goyal 86344d5bf10SVivek Goyal if (!ofs->config.metacopy) 86444d5bf10SVivek Goyal return false; 86544d5bf10SVivek Goyal 86644d5bf10SVivek Goyal if (!S_ISREG(mode)) 86744d5bf10SVivek Goyal return false; 86844d5bf10SVivek Goyal 86944d5bf10SVivek Goyal if (flags && ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC))) 87044d5bf10SVivek Goyal return false; 87144d5bf10SVivek Goyal 87244d5bf10SVivek Goyal return true; 87344d5bf10SVivek Goyal } 87444d5bf10SVivek Goyal 875*2d343087SAl Viro static ssize_t ovl_getxattr_value(const struct path *path, char *name, char **value) 876fee0f298SMiklos Szeredi { 877fee0f298SMiklos Szeredi ssize_t res; 878de7a52c9SMiklos Szeredi char *buf; 879fee0f298SMiklos Szeredi 880dad7017aSChristian Brauner res = ovl_do_getxattr(path, name, NULL, 0); 881fee0f298SMiklos Szeredi if (res == -ENODATA || res == -EOPNOTSUPP) 882de7a52c9SMiklos Szeredi res = 0; 883fee0f298SMiklos Szeredi 884de7a52c9SMiklos Szeredi if (res > 0) { 885de7a52c9SMiklos Szeredi buf = kzalloc(res, GFP_KERNEL); 886fee0f298SMiklos Szeredi if (!buf) 887fee0f298SMiklos Szeredi return -ENOMEM; 888fee0f298SMiklos Szeredi 889dad7017aSChristian Brauner res = ovl_do_getxattr(path, name, buf, res); 890fee0f298SMiklos Szeredi if (res < 0) 891fee0f298SMiklos Szeredi kfree(buf); 892de7a52c9SMiklos Szeredi else 893de7a52c9SMiklos Szeredi *value = buf; 894de7a52c9SMiklos Szeredi } 895fee0f298SMiklos Szeredi return res; 896fee0f298SMiklos Szeredi } 897fee0f298SMiklos Szeredi 8980c288874SVivek Goyal /* Copy up data of an inode which was copied up metadata only in the past. */ 8990c288874SVivek Goyal static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c) 9000c288874SVivek Goyal { 901c86243b0SVivek Goyal struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); 9024f93b426SVivek Goyal struct path upperpath, datapath; 9030c288874SVivek Goyal int err; 904993a0b2aSVivek Goyal char *capability = NULL; 9053f649ab7SKees Cook ssize_t cap_size; 9060c288874SVivek Goyal 9070c288874SVivek Goyal ovl_path_upper(c->dentry, &upperpath); 9080c288874SVivek Goyal if (WARN_ON(upperpath.dentry == NULL)) 9090c288874SVivek Goyal return -EIO; 9100c288874SVivek Goyal 9114f93b426SVivek Goyal ovl_path_lowerdata(c->dentry, &datapath); 9124f93b426SVivek Goyal if (WARN_ON(datapath.dentry == NULL)) 9134f93b426SVivek Goyal return -EIO; 9144f93b426SVivek Goyal 915993a0b2aSVivek Goyal if (c->stat.size) { 916dad7017aSChristian Brauner err = cap_size = ovl_getxattr_value(&upperpath, XATTR_NAME_CAPS, 917dad7017aSChristian Brauner &capability); 918de7a52c9SMiklos Szeredi if (cap_size < 0) 919993a0b2aSVivek Goyal goto out; 920993a0b2aSVivek Goyal } 921993a0b2aSVivek Goyal 922c86243b0SVivek Goyal err = ovl_copy_up_data(ofs, &datapath, &upperpath, c->stat.size); 9230c288874SVivek Goyal if (err) 924993a0b2aSVivek Goyal goto out_free; 925993a0b2aSVivek Goyal 926993a0b2aSVivek Goyal /* 927993a0b2aSVivek Goyal * Writing to upper file will clear security.capability xattr. We 928993a0b2aSVivek Goyal * don't want that to happen for normal copy-up operation. 929993a0b2aSVivek Goyal */ 930993a0b2aSVivek Goyal if (capability) { 931c914c0e2SAmir Goldstein err = ovl_do_setxattr(ofs, upperpath.dentry, XATTR_NAME_CAPS, 932c914c0e2SAmir Goldstein capability, cap_size, 0); 933993a0b2aSVivek Goyal if (err) 934993a0b2aSVivek Goyal goto out_free; 935993a0b2aSVivek Goyal } 936993a0b2aSVivek Goyal 9370c288874SVivek Goyal 938c914c0e2SAmir Goldstein err = ovl_removexattr(ofs, upperpath.dentry, OVL_XATTR_METACOPY); 9390c288874SVivek Goyal if (err) 940993a0b2aSVivek Goyal goto out_free; 9410c288874SVivek Goyal 9420c288874SVivek Goyal ovl_set_upperdata(d_inode(c->dentry)); 943993a0b2aSVivek Goyal out_free: 944993a0b2aSVivek Goyal kfree(capability); 945993a0b2aSVivek Goyal out: 9460c288874SVivek Goyal return err; 9470c288874SVivek Goyal } 9480c288874SVivek Goyal 949a6fb235aSMiklos Szeredi static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, 950a6fb235aSMiklos Szeredi int flags) 951a6fb235aSMiklos Szeredi { 952a6fb235aSMiklos Szeredi int err; 953a6fb235aSMiklos Szeredi DEFINE_DELAYED_CALL(done); 954a6fb235aSMiklos Szeredi struct path parentpath; 955a6fb235aSMiklos Szeredi struct ovl_copy_up_ctx ctx = { 956a6fb235aSMiklos Szeredi .parent = parent, 957a6fb235aSMiklos Szeredi .dentry = dentry, 958a6fb235aSMiklos Szeredi .workdir = ovl_workdir(dentry), 959a6fb235aSMiklos Szeredi }; 960a6fb235aSMiklos Szeredi 961a6fb235aSMiklos Szeredi if (WARN_ON(!ctx.workdir)) 962a6fb235aSMiklos Szeredi return -EROFS; 963a6fb235aSMiklos Szeredi 964a6fb235aSMiklos Szeredi ovl_path_lower(dentry, &ctx.lowerpath); 965a6fb235aSMiklos Szeredi err = vfs_getattr(&ctx.lowerpath, &ctx.stat, 966a6fb235aSMiklos Szeredi STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT); 967a6fb235aSMiklos Szeredi if (err) 968a6fb235aSMiklos Szeredi return err; 969a6fb235aSMiklos Szeredi 97044d5bf10SVivek Goyal ctx.metacopy = ovl_need_meta_copy_up(dentry, ctx.stat.mode, flags); 97144d5bf10SVivek Goyal 972aa3ff3c1SAmir Goldstein if (parent) { 973a6fb235aSMiklos Szeredi ovl_path_upper(parent, &parentpath); 97459be0971SAmir Goldstein ctx.destdir = parentpath.dentry; 97559be0971SAmir Goldstein ctx.destname = dentry->d_name; 976a6fb235aSMiklos Szeredi 977a6fb235aSMiklos Szeredi err = vfs_getattr(&parentpath, &ctx.pstat, 978aa3ff3c1SAmir Goldstein STATX_ATIME | STATX_MTIME, 979aa3ff3c1SAmir Goldstein AT_STATX_SYNC_AS_STAT); 980a6fb235aSMiklos Szeredi if (err) 981a6fb235aSMiklos Szeredi return err; 982aa3ff3c1SAmir Goldstein } 983a6fb235aSMiklos Szeredi 984a6fb235aSMiklos Szeredi /* maybe truncate regular file. this has no effect on dirs */ 985a6fb235aSMiklos Szeredi if (flags & O_TRUNC) 986a6fb235aSMiklos Szeredi ctx.stat.size = 0; 987a6fb235aSMiklos Szeredi 988a6fb235aSMiklos Szeredi if (S_ISLNK(ctx.stat.mode)) { 989a6fb235aSMiklos Szeredi ctx.link = vfs_get_link(ctx.lowerpath.dentry, &done); 990a6fb235aSMiklos Szeredi if (IS_ERR(ctx.link)) 991a6fb235aSMiklos Szeredi return PTR_ERR(ctx.link); 992a6fb235aSMiklos Szeredi } 993a6fb235aSMiklos Szeredi 9940c288874SVivek Goyal err = ovl_copy_up_start(dentry, flags); 995fd210b7dSMiklos Szeredi /* err < 0: interrupted, err > 0: raced with another copy-up */ 996fd210b7dSMiklos Szeredi if (unlikely(err)) { 997fd210b7dSMiklos Szeredi if (err > 0) 998fd210b7dSMiklos Szeredi err = 0; 999fd210b7dSMiklos Szeredi } else { 100059be0971SAmir Goldstein if (!ovl_dentry_upper(dentry)) 1001a6fb235aSMiklos Szeredi err = ovl_do_copy_up(&ctx); 1002aa3ff3c1SAmir Goldstein if (!err && parent && !ovl_dentry_has_upper_alias(dentry)) 1003f4439de1SAmir Goldstein err = ovl_link_up(&ctx); 10040c288874SVivek Goyal if (!err && ovl_dentry_needs_data_copy_up_locked(dentry, flags)) 10050c288874SVivek Goyal err = ovl_copy_up_meta_inode_data(&ctx); 1006fd210b7dSMiklos Szeredi ovl_copy_up_end(dentry); 1007fd210b7dSMiklos Szeredi } 10087764235bSMiklos Szeredi do_delayed_call(&done); 1009e9be9d5eSMiklos Szeredi 1010e9be9d5eSMiklos Szeredi return err; 1011e9be9d5eSMiklos Szeredi } 1012e9be9d5eSMiklos Szeredi 10135ac8e802Syoungjun static int ovl_copy_up_flags(struct dentry *dentry, int flags) 1014e9be9d5eSMiklos Szeredi { 10158eac98b8SVivek Goyal int err = 0; 10167b279bbfSDan Carpenter const struct cred *old_cred; 1017aa3ff3c1SAmir Goldstein bool disconnected = (dentry->d_flags & DCACHE_DISCONNECTED); 1018aa3ff3c1SAmir Goldstein 1019aa3ff3c1SAmir Goldstein /* 1020aa3ff3c1SAmir Goldstein * With NFS export, copy up can get called for a disconnected non-dir. 1021aa3ff3c1SAmir Goldstein * In this case, we will copy up lower inode to index dir without 1022aa3ff3c1SAmir Goldstein * linking it to upper dir. 1023aa3ff3c1SAmir Goldstein */ 1024aa3ff3c1SAmir Goldstein if (WARN_ON(disconnected && d_is_dir(dentry))) 1025aa3ff3c1SAmir Goldstein return -EIO; 1026e9be9d5eSMiklos Szeredi 10277b279bbfSDan Carpenter old_cred = ovl_override_creds(dentry->d_sb); 1028e9be9d5eSMiklos Szeredi while (!err) { 1029e9be9d5eSMiklos Szeredi struct dentry *next; 1030aa3ff3c1SAmir Goldstein struct dentry *parent = NULL; 1031e9be9d5eSMiklos Szeredi 10320c288874SVivek Goyal if (ovl_already_copied_up(dentry, flags)) 1033e9be9d5eSMiklos Szeredi break; 1034e9be9d5eSMiklos Szeredi 1035e9be9d5eSMiklos Szeredi next = dget(dentry); 1036e9be9d5eSMiklos Szeredi /* find the topmost dentry not yet copied up */ 1037aa3ff3c1SAmir Goldstein for (; !disconnected;) { 1038e9be9d5eSMiklos Szeredi parent = dget_parent(next); 1039e9be9d5eSMiklos Szeredi 104059be0971SAmir Goldstein if (ovl_dentry_upper(parent)) 1041e9be9d5eSMiklos Szeredi break; 1042e9be9d5eSMiklos Szeredi 1043e9be9d5eSMiklos Szeredi dput(next); 1044e9be9d5eSMiklos Szeredi next = parent; 1045e9be9d5eSMiklos Szeredi } 1046e9be9d5eSMiklos Szeredi 1047a6fb235aSMiklos Szeredi err = ovl_copy_up_one(parent, next, flags); 1048e9be9d5eSMiklos Szeredi 1049e9be9d5eSMiklos Szeredi dput(parent); 1050e9be9d5eSMiklos Szeredi dput(next); 1051e9be9d5eSMiklos Szeredi } 10528eac98b8SVivek Goyal revert_creds(old_cred); 1053e9be9d5eSMiklos Szeredi 1054e9be9d5eSMiklos Szeredi return err; 1055e9be9d5eSMiklos Szeredi } 10569aba6521SAmir Goldstein 1057d6eac039SVivek Goyal static bool ovl_open_need_copy_up(struct dentry *dentry, int flags) 1058d6eac039SVivek Goyal { 1059d6eac039SVivek Goyal /* Copy up of disconnected dentry does not set upper alias */ 10600c288874SVivek Goyal if (ovl_already_copied_up(dentry, flags)) 1061d6eac039SVivek Goyal return false; 1062d6eac039SVivek Goyal 1063d6eac039SVivek Goyal if (special_file(d_inode(dentry)->i_mode)) 1064d6eac039SVivek Goyal return false; 1065d6eac039SVivek Goyal 10660c288874SVivek Goyal if (!ovl_open_flags_need_copy_up(flags)) 1067d6eac039SVivek Goyal return false; 1068d6eac039SVivek Goyal 1069d6eac039SVivek Goyal return true; 1070d6eac039SVivek Goyal } 1071d6eac039SVivek Goyal 10723428030dSAmir Goldstein int ovl_maybe_copy_up(struct dentry *dentry, int flags) 1073d6eac039SVivek Goyal { 1074d6eac039SVivek Goyal int err = 0; 1075d6eac039SVivek Goyal 10763428030dSAmir Goldstein if (ovl_open_need_copy_up(dentry, flags)) { 1077d6eac039SVivek Goyal err = ovl_want_write(dentry); 1078d6eac039SVivek Goyal if (!err) { 10793428030dSAmir Goldstein err = ovl_copy_up_flags(dentry, flags); 1080d6eac039SVivek Goyal ovl_drop_write(dentry); 1081d6eac039SVivek Goyal } 1082d6eac039SVivek Goyal } 1083d6eac039SVivek Goyal 1084d6eac039SVivek Goyal return err; 1085d6eac039SVivek Goyal } 1086d6eac039SVivek Goyal 1087d1e6f6a9SVivek Goyal int ovl_copy_up_with_data(struct dentry *dentry) 1088d1e6f6a9SVivek Goyal { 1089d1e6f6a9SVivek Goyal return ovl_copy_up_flags(dentry, O_WRONLY); 1090d1e6f6a9SVivek Goyal } 1091d1e6f6a9SVivek Goyal 10929aba6521SAmir Goldstein int ovl_copy_up(struct dentry *dentry) 10939aba6521SAmir Goldstein { 10949aba6521SAmir Goldstein return ovl_copy_up_flags(dentry, 0); 10959aba6521SAmir Goldstein } 1096