// SPDX-License-Identifier: GPL-2.0-only /* * This file is part of UBIFS. * * Copyright (C) 2006-2008 Nokia Corporation. * Copyright (C) 2006, 2007 University of Szeged, Hungary * * Authors: Artem Bityutskiy (Битюцкий Артём) * Adrian Hunter * Zoltan Sogor */ /* * This file implements directory operations. * * All FS operations in this file allocate budget before writing anything to the * media. If they fail to allocate it, the error is returned. The only * exceptions are 'ubifs_unlink()' and 'ubifs_rmdir()' which keep working even * if they unable to allocate the budget, because deletion %-ENOSPC failure is * not what users are usually ready to get. UBIFS budgeting subsystem has some * space reserved for these purposes. * * All operations in this file write all inodes which they change straight * away, instead of marking them dirty. For example, 'ubifs_link()' changes * @i_size of the parent inode and writes the parent inode together with the * target inode. This was done to simplify file-system recovery which would * otherwise be very difficult to do. The only exception is rename which marks * the re-named inode dirty (because its @i_ctime is updated) but does not * write it, but just marks it as dirty. */ #include "ubifs.h" /** * inherit_flags - inherit flags of the parent inode. * @dir: parent inode * @mode: new inode mode flags * * This is a helper function for 'ubifs_new_inode()' which inherits flag of the * parent directory inode @dir. UBIFS inodes inherit the following flags: * o %UBIFS_COMPR_FL, which is useful to switch compression on/of on * sub-directory basis; * o %UBIFS_SYNC_FL - useful for the same reasons; * o %UBIFS_DIRSYNC_FL - similar, but relevant only to directories. * * This function returns the inherited flags. */ static int inherit_flags(const struct inode *dir, umode_t mode) { int flags; const struct ubifs_inode *ui = ubifs_inode(dir); if (!S_ISDIR(dir->i_mode)) /* * The parent is not a directory, which means that an extended * attribute inode is being created. No flags. */ return 0; flags = ui->flags & (UBIFS_COMPR_FL | UBIFS_SYNC_FL | UBIFS_DIRSYNC_FL); if (!S_ISDIR(mode)) /* The "DIRSYNC" flag only applies to directories */ flags &= ~UBIFS_DIRSYNC_FL; return flags; } /** * ubifs_new_inode - allocate new UBIFS inode object. * @c: UBIFS file-system description object * @dir: parent directory inode * @mode: inode mode flags * * This function finds an unused inode number, allocates new inode and * initializes it. Returns new inode in case of success and an error code in * case of failure. */ struct inode *ubifs_new_inode(struct ubifs_info *c, struct inode *dir, umode_t mode) { int err; struct inode *inode; struct ubifs_inode *ui; bool encrypted = false; inode = new_inode(c->vfs_sb); ui = ubifs_inode(inode); if (!inode) return ERR_PTR(-ENOMEM); /* * Set 'S_NOCMTIME' to prevent VFS form updating [mc]time of inodes and * marking them dirty in file write path (see 'file_update_time()'). * UBIFS has to fully control "clean <-> dirty" transitions of inodes * to make budgeting work. */ inode->i_flags |= S_NOCMTIME; inode_init_owner(inode, dir, mode); inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); inode->i_mapping->nrpages = 0; err = fscrypt_prepare_new_inode(dir, inode, &encrypted); if (err) { ubifs_err(c, "fscrypt_prepare_new_inode failed: %i", err); goto out_iput; } switch (mode & S_IFMT) { case S_IFREG: inode->i_mapping->a_ops = &ubifs_file_address_operations; inode->i_op = &ubifs_file_inode_operations; inode->i_fop = &ubifs_file_operations; break; case S_IFDIR: inode->i_op = &ubifs_dir_inode_operations; inode->i_fop = &ubifs_dir_operations; inode->i_size = ui->ui_size = UBIFS_INO_NODE_SZ; break; case S_IFLNK: inode->i_op = &ubifs_symlink_inode_operations; break; case S_IFSOCK: case S_IFIFO: case S_IFBLK: case S_IFCHR: inode->i_op = &ubifs_file_inode_operations; break; default: BUG(); } ui->flags = inherit_flags(dir, mode); ubifs_set_inode_flags(inode); if (S_ISREG(mode)) ui->compr_type = c->default_compr; else ui->compr_type = UBIFS_COMPR_NONE; ui->synced_i_size = 0; spin_lock(&c->cnt_lock); /* Inode number overflow is currently not supported */ if (c->highest_inum >= INUM_WARN_WATERMARK) { if (c->highest_inum >= INUM_WATERMARK) { spin_unlock(&c->cnt_lock); ubifs_err(c, "out of inode numbers"); err = -EINVAL; goto out_iput; } ubifs_warn(c, "running out of inode numbers (current %lu, max %u)", (unsigned long)c->highest_inum, INUM_WATERMARK); } inode->i_ino = ++c->highest_inum; /* * The creation sequence number remains with this inode for its * lifetime. All nodes for this inode have a greater sequence number, * and so it is possible to distinguish obsolete nodes belonging to a * previous incarnation of the same inode number - for example, for the * purpose of rebuilding the index. */ ui->creat_sqnum = ++c->max_sqnum; spin_unlock(&c->cnt_lock); if (encrypted) { err = fscrypt_set_context(inode, NULL); if (err) { ubifs_err(c, "fscrypt_set_context failed: %i", err); goto out_iput; } } return inode; out_iput: make_bad_inode(inode); iput(inode); return ERR_PTR(err); } static int dbg_check_name(const struct ubifs_info *c, const struct ubifs_dent_node *dent, const struct fscrypt_name *nm) { if (!dbg_is_chk_gen(c)) return 0; if (le16_to_cpu(dent->nlen) != fname_len(nm)) return -EINVAL; if (memcmp(dent->name, fname_name(nm), fname_len(nm))) return -EINVAL; return 0; } static struct dentry *ubifs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) { int err; union ubifs_key key; struct inode *inode = NULL; struct ubifs_dent_node *dent = NULL; struct ubifs_info *c = dir->i_sb->s_fs_info; struct fscrypt_name nm; dbg_gen("'%pd' in dir ino %lu", dentry, dir->i_ino); err = fscrypt_prepare_lookup(dir, dentry, &nm); generic_set_encrypted_ci_d_ops(dentry); if (err == -ENOENT) return d_splice_alias(NULL, dentry); if (err) return ERR_PTR(err); if (fname_len(&nm) > UBIFS_MAX_NLEN) { inode = ERR_PTR(-ENAMETOOLONG); goto done; } dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS); if (!dent) { inode = ERR_PTR(-ENOMEM); goto done; } if (fname_name(&nm) == NULL) { if (nm.hash & ~UBIFS_S_KEY_HASH_MASK) goto done; /* ENOENT */ dent_key_init_hash(c, &key, dir->i_ino, nm.hash); err = ubifs_tnc_lookup_dh(c, &key, dent, nm.minor_hash); } else { dent_key_init(c, &key, dir->i_ino, &nm); err = ubifs_tnc_lookup_nm(c, &key, dent, &nm); } if (err) { if (err == -ENOENT) dbg_gen("not found"); else inode = ERR_PTR(err); goto done; } if (dbg_check_name(c, dent, &nm)) { inode = ERR_PTR(-EINVAL); goto done; } inode = ubifs_iget(dir->i_sb, le64_to_cpu(dent->inum)); if (IS_ERR(inode)) { /* * This should not happen. Probably the file-system needs * checking. */ err = PTR_ERR(inode); ubifs_err(c, "dead directory entry '%pd', error %d", dentry, err); ubifs_ro_mode(c, err); goto done; } if (IS_ENCRYPTED(dir) && (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) && !fscrypt_has_permitted_context(dir, inode)) { ubifs_warn(c, "Inconsistent encryption contexts: %lu/%lu", dir->i_ino, inode->i_ino); iput(inode); inode = ERR_PTR(-EPERM); } done: kfree(dent); fscrypt_free_filename(&nm); return d_splice_alias(inode, dentry); } static int ubifs_prepare_create(struct inode *dir, struct dentry *dentry, struct fscrypt_name *nm) { if (fscrypt_is_nokey_name(dentry)) return -ENOKEY; return fscrypt_setup_filename(dir, &dentry->d_name, 0, nm); } static int ubifs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl) { struct inode *inode; struct ubifs_info *c = dir->i_sb->s_fs_info; struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, .dirtied_ino = 1 }; struct ubifs_inode *dir_ui = ubifs_inode(dir); struct fscrypt_name nm; int err, sz_change; /* * Budget request settings: new inode, new direntry, changing the * parent directory inode. */ dbg_gen("dent '%pd', mode %#hx in dir ino %lu", dentry, mode, dir->i_ino); err = ubifs_budget_space(c, &req); if (err) return err; err = ubifs_prepare_create(dir, dentry, &nm); if (err) goto out_budg; sz_change = CALC_DENT_SIZE(fname_len(&nm)); inode = ubifs_new_inode(c, dir, mode); if (IS_ERR(inode)) { err = PTR_ERR(inode); goto out_fname; } err = ubifs_init_security(dir, inode, &dentry->d_name); if (err) goto out_inode; mutex_lock(&dir_ui->ui_mutex); dir->i_size += sz_change; dir_ui->ui_size = dir->i_size; dir->i_mtime = dir->i_ctime = inode->i_ctime; err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0); if (err) goto out_cancel; mutex_unlock(&dir_ui->ui_mutex); ubifs_release_budget(c, &req); fscrypt_free_filename(&nm); insert_inode_hash(inode); d_instantiate(dentry, inode); return 0; out_cancel: dir->i_size -= sz_change; dir_ui->ui_size = dir->i_size; mutex_unlock(&dir_ui->ui_mutex); out_inode: make_bad_inode(inode); iput(inode); out_fname: fscrypt_free_filename(&nm); out_budg: ubifs_release_budget(c, &req); ubifs_err(c, "cannot create regular file, error %d", err); return err; } static int do_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode, struct inode **whiteout) { struct inode *inode; struct ubifs_info *c = dir->i_sb->s_fs_info; struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, .dirtied_ino = 1}; struct ubifs_budget_req ino_req = { .dirtied_ino = 1 }; struct ubifs_inode *ui, *dir_ui = ubifs_inode(dir); int err, instantiated = 0; struct fscrypt_name nm; /* * Budget request settings: new inode, new direntry, changing the * parent directory inode. * Allocate budget separately for new dirtied inode, the budget will * be released via writeback. */ dbg_gen("dent '%pd', mode %#hx in dir ino %lu", dentry, mode, dir->i_ino); err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm); if (err) return err; err = ubifs_budget_space(c, &req); if (err) { fscrypt_free_filename(&nm); return err; } err = ubifs_budget_space(c, &ino_req); if (err) { ubifs_release_budget(c, &req); fscrypt_free_filename(&nm); return err; } inode = ubifs_new_inode(c, dir, mode); if (IS_ERR(inode)) { err = PTR_ERR(inode); goto out_budg; } ui = ubifs_inode(inode); if (whiteout) { init_special_inode(inode, inode->i_mode, WHITEOUT_DEV); ubifs_assert(c, inode->i_op == &ubifs_file_inode_operations); } err = ubifs_init_security(dir, inode, &dentry->d_name); if (err) goto out_inode; mutex_lock(&ui->ui_mutex); insert_inode_hash(inode); if (whiteout) { mark_inode_dirty(inode); drop_nlink(inode); *whiteout = inode; } else { d_tmpfile(dentry, inode); } ubifs_assert(c, ui->dirty); instantiated = 1; mutex_unlock(&ui->ui_mutex); mutex_lock(&dir_ui->ui_mutex); err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0); if (err) goto out_cancel; mutex_unlock(&dir_ui->ui_mutex); ubifs_release_budget(c, &req); fscrypt_free_filename(&nm); return 0; out_cancel: mutex_unlock(&dir_ui->ui_mutex); out_inode: make_bad_inode(inode); if (!instantiated) iput(inode); else if (whiteout) iput(*whiteout); out_budg: ubifs_release_budget(c, &req); if (!instantiated) ubifs_release_budget(c, &ino_req); fscrypt_free_filename(&nm); ubifs_err(c, "cannot create temporary file, error %d", err); return err; } static int ubifs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) { return do_tmpfile(dir, dentry, mode, NULL); } /** * vfs_dent_type - get VFS directory entry type. * @type: UBIFS directory entry type * * This function converts UBIFS directory entry type into VFS directory entry * type. */ static unsigned int vfs_dent_type(uint8_t type) { switch (type) { case UBIFS_ITYPE_REG: return DT_REG; case UBIFS_ITYPE_DIR: return DT_DIR; case UBIFS_ITYPE_LNK: return DT_LNK; case UBIFS_ITYPE_BLK: return DT_BLK; case UBIFS_ITYPE_CHR: return DT_CHR; case UBIFS_ITYPE_FIFO: return DT_FIFO; case UBIFS_ITYPE_SOCK: return DT_SOCK; default: BUG(); } return 0; } /* * The classical Unix view for directory is that it is a linear array of * (name, inode number) entries. Linux/VFS assumes this model as well. * Particularly, 'readdir()' call wants us to return a directory entry offset * which later may be used to continue 'readdir()'ing the directory or to * 'seek()' to that specific direntry. Obviously UBIFS does not really fit this * model because directory entries are identified by keys, which may collide. * * UBIFS uses directory entry hash value for directory offsets, so * 'seekdir()'/'telldir()' may not always work because of possible key * collisions. But UBIFS guarantees that consecutive 'readdir()' calls work * properly by means of saving full directory entry name in the private field * of the file description object. * * This means that UBIFS cannot support NFS which requires full * 'seekdir()'/'telldir()' support. */ static int ubifs_readdir(struct file *file, struct dir_context *ctx) { int fstr_real_len = 0, err = 0; struct fscrypt_name nm; struct fscrypt_str fstr = {0}; union ubifs_key key; struct ubifs_dent_node *dent; struct inode *dir = file_inode(file); struct ubifs_info *c = dir->i_sb->s_fs_info; bool encrypted = IS_ENCRYPTED(dir); dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, ctx->pos); if (ctx->pos > UBIFS_S_KEY_HASH_MASK || ctx->pos == 2) /* * The directory was seek'ed to a senseless position or there * are no more entries. */ return 0; if (encrypted) { err = fscrypt_prepare_readdir(dir); if (err) return err; err = fscrypt_fname_alloc_buffer(UBIFS_MAX_NLEN, &fstr); if (err) return err; fstr_real_len = fstr.len; } if (file->f_version == 0) { /* * The file was seek'ed, which means that @file->private_data * is now invalid. This may also be just the first * 'ubifs_readdir()' invocation, in which case * @file->private_data is NULL, and the below code is * basically a no-op. */ kfree(file->private_data); file->private_data = NULL; } /* * 'generic_file_llseek()' unconditionally sets @file->f_version to * zero, and we use this for detecting whether the file was seek'ed. */ file->f_version = 1; /* File positions 0 and 1 correspond to "." and ".." */ if (ctx->pos < 2) { ubifs_assert(c, !file->private_data); if (!dir_emit_dots(file, ctx)) { if (encrypted) fscrypt_fname_free_buffer(&fstr); return 0; } /* Find the first entry in TNC and save it */ lowest_dent_key(c, &key, dir->i_ino); fname_len(&nm) = 0; dent = ubifs_tnc_next_ent(c, &key, &nm); if (IS_ERR(dent)) { err = PTR_ERR(dent); goto out; } ctx->pos = key_hash_flash(c, &dent->key); file->private_data = dent; } dent = file->private_data; if (!dent) { /* * The directory was seek'ed to and is now readdir'ed. * Find the entry corresponding to @ctx->pos or the closest one. */ dent_key_init_hash(c, &key, dir->i_ino, ctx->pos); fname_len(&nm) = 0; dent = ubifs_tnc_next_ent(c, &key, &nm); if (IS_ERR(dent)) { err = PTR_ERR(dent); goto out; } ctx->pos = key_hash_flash(c, &dent->key); file->private_data = dent; } while (1) { dbg_gen("ino %llu, new f_pos %#x", (unsigned long long)le64_to_cpu(dent->inum), key_hash_flash(c, &dent->key)); ubifs_assert(c, le64_to_cpu(dent->ch.sqnum) > ubifs_inode(dir)->creat_sqnum); fname_len(&nm) = le16_to_cpu(dent->nlen); fname_name(&nm) = dent->name; if (encrypted) { fstr.len = fstr_real_len; err = fscrypt_fname_disk_to_usr(dir, key_hash_flash(c, &dent->key), le32_to_cpu(dent->cookie), &nm.disk_name, &fstr); if (err) goto out; } else { fstr.len = fname_len(&nm); fstr.name = fname_name(&nm); } if (!dir_emit(ctx, fstr.name, fstr.len, le64_to_cpu(dent->inum), vfs_dent_type(dent->type))) { if (encrypted) fscrypt_fname_free_buffer(&fstr); return 0; } /* Switch to the next entry */ key_read(c, &dent->key, &key); dent = ubifs_tnc_next_ent(c, &key, &nm); if (IS_ERR(dent)) { err = PTR_ERR(dent); goto out; } kfree(file->private_data); ctx->pos = key_hash_flash(c, &dent->key); file->private_data = dent; cond_resched(); } out: kfree(file->private_data); file->private_data = NULL; if (encrypted) fscrypt_fname_free_buffer(&fstr); if (err != -ENOENT) ubifs_err(c, "cannot find next direntry, error %d", err); else /* * -ENOENT is a non-fatal error in this context, the TNC uses * it to indicate that the cursor moved past the current directory * and readdir() has to stop. */ err = 0; /* 2 is a special value indicating that there are no more direntries */ ctx->pos = 2; return err; } /* Free saved readdir() state when the directory is closed */ static int ubifs_dir_release(struct inode *dir, struct file *file) { kfree(file->private_data); file->private_data = NULL; return 0; } /** * lock_2_inodes - a wrapper for locking two UBIFS inodes. * @inode1: first inode * @inode2: second inode * * We do not implement any tricks to guarantee strict lock ordering, because * VFS has already done it for us on the @i_mutex. So this is just a simple * wrapper function. */ static void lock_2_inodes(struct inode *inode1, struct inode *inode2) { mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1); mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2); } /** * unlock_2_inodes - a wrapper for unlocking two UBIFS inodes. * @inode1: first inode * @inode2: second inode */ static void unlock_2_inodes(struct inode *inode1, struct inode *inode2) { mutex_unlock(&ubifs_inode(inode2)->ui_mutex); mutex_unlock(&ubifs_inode(inode1)->ui_mutex); } static int ubifs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) { struct ubifs_info *c = dir->i_sb->s_fs_info; struct inode *inode = d_inode(old_dentry); struct ubifs_inode *ui = ubifs_inode(inode); struct ubifs_inode *dir_ui = ubifs_inode(dir); int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len); struct ubifs_budget_req req = { .new_dent = 1, .dirtied_ino = 2, .dirtied_ino_d = ALIGN(ui->data_len, 8) }; struct fscrypt_name nm; /* * Budget request settings: new direntry, changing the target inode, * changing the parent inode. */ dbg_gen("dent '%pd' to ino %lu (nlink %d) in dir ino %lu", dentry, inode->i_ino, inode->i_nlink, dir->i_ino); ubifs_assert(c, inode_is_locked(dir)); ubifs_assert(c, inode_is_locked(inode)); err = fscrypt_prepare_link(old_dentry, dir, dentry); if (err) return err; err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm); if (err) return err; err = dbg_check_synced_i_size(c, inode); if (err) goto out_fname; err = ubifs_budget_space(c, &req); if (err) goto out_fname; lock_2_inodes(dir, inode); /* Handle O_TMPFILE corner case, it is allowed to link a O_TMPFILE. */ if (inode->i_nlink == 0) ubifs_delete_orphan(c, inode->i_ino); inc_nlink(inode); ihold(inode); inode->i_ctime = current_time(inode); dir->i_size += sz_change; dir_ui->ui_size = dir->i_size; dir->i_mtime = dir->i_ctime = inode->i_ctime; err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0); if (err) goto out_cancel; unlock_2_inodes(dir, inode); ubifs_release_budget(c, &req); d_instantiate(dentry, inode); fscrypt_free_filename(&nm); return 0; out_cancel: dir->i_size -= sz_change; dir_ui->ui_size = dir->i_size; drop_nlink(inode); if (inode->i_nlink == 0) ubifs_add_orphan(c, inode->i_ino); unlock_2_inodes(dir, inode); ubifs_release_budget(c, &req); iput(inode); out_fname: fscrypt_free_filename(&nm); return err; } static int ubifs_unlink(struct inode *dir, struct dentry *dentry) { struct ubifs_info *c = dir->i_sb->s_fs_info; struct inode *inode = d_inode(dentry); struct ubifs_inode *dir_ui = ubifs_inode(dir); int err, sz_change, budgeted = 1; struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 }; unsigned int saved_nlink = inode->i_nlink; struct fscrypt_name nm; /* * Budget request settings: deletion direntry, deletion inode (+1 for * @dirtied_ino), changing the parent directory inode. If budgeting * fails, go ahead anyway because we have extra space reserved for * deletions. */ dbg_gen("dent '%pd' from ino %lu (nlink %d) in dir ino %lu", dentry, inode->i_ino, inode->i_nlink, dir->i_ino); err = fscrypt_setup_filename(dir, &dentry->d_name, 1, &nm); if (err) return err; err = ubifs_purge_xattrs(inode); if (err) return err; sz_change = CALC_DENT_SIZE(fname_len(&nm)); ubifs_assert(c, inode_is_locked(dir)); ubifs_assert(c, inode_is_locked(inode)); err = dbg_check_synced_i_size(c, inode); if (err) goto out_fname; err = ubifs_budget_space(c, &req); if (err) { if (err != -ENOSPC) goto out_fname; budgeted = 0; } lock_2_inodes(dir, inode); inode->i_ctime = current_time(dir); drop_nlink(inode); dir->i_size -= sz_change; dir_ui->ui_size = dir->i_size; dir->i_mtime = dir->i_ctime = inode->i_ctime; err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0); if (err) goto out_cancel; unlock_2_inodes(dir, inode); if (budgeted) ubifs_release_budget(c, &req); else { /* We've deleted something - clean the "no space" flags */ c->bi.nospace = c->bi.nospace_rp = 0; smp_wmb(); } fscrypt_free_filename(&nm); return 0; out_cancel: dir->i_size += sz_change; dir_ui->ui_size = dir->i_size; set_nlink(inode, saved_nlink); unlock_2_inodes(dir, inode); if (budgeted) ubifs_release_budget(c, &req); out_fname: fscrypt_free_filename(&nm); return err; } /** * check_dir_empty - check if a directory is empty or not. * @dir: VFS inode object of the directory to check * * This function checks if directory @dir is empty. Returns zero if the * directory is empty, %-ENOTEMPTY if it is not, and other negative error codes * in case of of errors. */ int ubifs_check_dir_empty(struct inode *dir) { struct ubifs_info *c = dir->i_sb->s_fs_info; struct fscrypt_name nm = { 0 }; struct ubifs_dent_node *dent; union ubifs_key key; int err; lowest_dent_key(c, &key, dir->i_ino); dent = ubifs_tnc_next_ent(c, &key, &nm); if (IS_ERR(dent)) { err = PTR_ERR(dent); if (err == -ENOENT) err = 0; } else { kfree(dent); err = -ENOTEMPTY; } return err; } static int ubifs_rmdir(struct inode *dir, struct dentry *dentry) { struct ubifs_info *c = dir->i_sb->s_fs_info; struct inode *inode = d_inode(dentry); int err, sz_change, budgeted = 1; struct ubifs_inode *dir_ui = ubifs_inode(dir); struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 }; struct fscrypt_name nm; /* * Budget request settings: deletion direntry, deletion inode and * changing the parent inode. If budgeting fails, go ahead anyway * because we have extra space reserved for deletions. */ dbg_gen("directory '%pd', ino %lu in dir ino %lu", dentry, inode->i_ino, dir->i_ino); ubifs_assert(c, inode_is_locked(dir)); ubifs_assert(c, inode_is_locked(inode)); err = ubifs_check_dir_empty(d_inode(dentry)); if (err) return err; err = fscrypt_setup_filename(dir, &dentry->d_name, 1, &nm); if (err) return err; err = ubifs_purge_xattrs(inode); if (err) return err; sz_change = CALC_DENT_SIZE(fname_len(&nm)); err = ubifs_budget_space(c, &req); if (err) { if (err != -ENOSPC) goto out_fname; budgeted = 0; } lock_2_inodes(dir, inode); inode->i_ctime = current_time(dir); clear_nlink(inode); drop_nlink(dir); dir->i_size -= sz_change; dir_ui->ui_size = dir->i_size; dir->i_mtime = dir->i_ctime = inode->i_ctime; err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0); if (err) goto out_cancel; unlock_2_inodes(dir, inode); if (budgeted) ubifs_release_budget(c, &req); else { /* We've deleted something - clean the "no space" flags */ c->bi.nospace = c->bi.nospace_rp = 0; smp_wmb(); } fscrypt_free_filename(&nm); return 0; out_cancel: dir->i_size += sz_change; dir_ui->ui_size = dir->i_size; inc_nlink(dir); set_nlink(inode, 2); unlock_2_inodes(dir, inode); if (budgeted) ubifs_release_budget(c, &req); out_fname: fscrypt_free_filename(&nm); return err; } static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) { struct inode *inode; struct ubifs_inode *dir_ui = ubifs_inode(dir); struct ubifs_info *c = dir->i_sb->s_fs_info; int err, sz_change; struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, .dirtied_ino = 1}; struct fscrypt_name nm; /* * Budget request settings: new inode, new direntry and changing parent * directory inode. */ dbg_gen("dent '%pd', mode %#hx in dir ino %lu", dentry, mode, dir->i_ino); err = ubifs_budget_space(c, &req); if (err) return err; err = ubifs_prepare_create(dir, dentry, &nm); if (err) goto out_budg; sz_change = CALC_DENT_SIZE(fname_len(&nm)); inode = ubifs_new_inode(c, dir, S_IFDIR | mode); if (IS_ERR(inode)) { err = PTR_ERR(inode); goto out_fname; } err = ubifs_init_security(dir, inode, &dentry->d_name); if (err) goto out_inode; mutex_lock(&dir_ui->ui_mutex); insert_inode_hash(inode); inc_nlink(inode); inc_nlink(dir); dir->i_size += sz_change; dir_ui->ui_size = dir->i_size; dir->i_mtime = dir->i_ctime = inode->i_ctime; err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0); if (err) { ubifs_err(c, "cannot create directory, error %d", err); goto out_cancel; } mutex_unlock(&dir_ui->ui_mutex); ubifs_release_budget(c, &req); d_instantiate(dentry, inode); fscrypt_free_filename(&nm); return 0; out_cancel: dir->i_size -= sz_change; dir_ui->ui_size = dir->i_size; drop_nlink(dir); mutex_unlock(&dir_ui->ui_mutex); out_inode: make_bad_inode(inode); iput(inode); out_fname: fscrypt_free_filename(&nm); out_budg: ubifs_release_budget(c, &req); return err; } static int ubifs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev) { struct inode *inode; struct ubifs_inode *ui; struct ubifs_inode *dir_ui = ubifs_inode(dir); struct ubifs_info *c = dir->i_sb->s_fs_info; union ubifs_dev_desc *dev = NULL; int sz_change; int err, devlen = 0; struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, .dirtied_ino = 1 }; struct fscrypt_name nm; /* * Budget request settings: new inode, new direntry and changing parent * directory inode. */ dbg_gen("dent '%pd' in dir ino %lu", dentry, dir->i_ino); if (S_ISBLK(mode) || S_ISCHR(mode)) { dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS); if (!dev) return -ENOMEM; devlen = ubifs_encode_dev(dev, rdev); } req.new_ino_d = ALIGN(devlen, 8); err = ubifs_budget_space(c, &req); if (err) { kfree(dev); return err; } err = ubifs_prepare_create(dir, dentry, &nm); if (err) { kfree(dev); goto out_budg; } sz_change = CALC_DENT_SIZE(fname_len(&nm)); inode = ubifs_new_inode(c, dir, mode); if (IS_ERR(inode)) { kfree(dev); err = PTR_ERR(inode); goto out_fname; } init_special_inode(inode, inode->i_mode, rdev); inode->i_size = ubifs_inode(inode)->ui_size = devlen; ui = ubifs_inode(inode); ui->data = dev; ui->data_len = devlen; err = ubifs_init_security(dir, inode, &dentry->d_name); if (err) goto out_inode; mutex_lock(&dir_ui->ui_mutex); dir->i_size += sz_change; dir_ui->ui_size = dir->i_size; dir->i_mtime = dir->i_ctime = inode->i_ctime; err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0); if (err) goto out_cancel; mutex_unlock(&dir_ui->ui_mutex); ubifs_release_budget(c, &req); insert_inode_hash(inode); d_instantiate(dentry, inode); fscrypt_free_filename(&nm); return 0; out_cancel: dir->i_size -= sz_change; dir_ui->ui_size = dir->i_size; mutex_unlock(&dir_ui->ui_mutex); out_inode: make_bad_inode(inode); iput(inode); out_fname: fscrypt_free_filename(&nm); out_budg: ubifs_release_budget(c, &req); return err; } static int ubifs_symlink(struct inode *dir, struct dentry *dentry, const char *symname) { struct inode *inode; struct ubifs_inode *ui; struct ubifs_inode *dir_ui = ubifs_inode(dir); struct ubifs_info *c = dir->i_sb->s_fs_info; int err, sz_change, len = strlen(symname); struct fscrypt_str disk_link; struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, .dirtied_ino = 1 }; struct fscrypt_name nm; dbg_gen("dent '%pd', target '%s' in dir ino %lu", dentry, symname, dir->i_ino); err = fscrypt_prepare_symlink(dir, symname, len, UBIFS_MAX_INO_DATA, &disk_link); if (err) return err; /* * Budget request settings: new inode, new direntry and changing parent * directory inode. */ req.new_ino_d = ALIGN(disk_link.len - 1, 8); err = ubifs_budget_space(c, &req); if (err) return err; err = ubifs_prepare_create(dir, dentry, &nm); if (err) goto out_budg; sz_change = CALC_DENT_SIZE(fname_len(&nm)); inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO); if (IS_ERR(inode)) { err = PTR_ERR(inode); goto out_fname; } ui = ubifs_inode(inode); ui->data = kmalloc(disk_link.len, GFP_NOFS); if (!ui->data) { err = -ENOMEM; goto out_inode; } if (IS_ENCRYPTED(inode)) { disk_link.name = ui->data; /* encrypt directly into ui->data */ err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link); if (err) goto out_inode; } else { memcpy(ui->data, disk_link.name, disk_link.len); inode->i_link = ui->data; } /* * The terminating zero byte is not written to the flash media and it * is put just to make later in-memory string processing simpler. Thus, * data length is @disk_link.len - 1, not @disk_link.len. */ ui->data_len = disk_link.len - 1; inode->i_size = ubifs_inode(inode)->ui_size = disk_link.len - 1; err = ubifs_init_security(dir, inode, &dentry->d_name); if (err) goto out_inode; mutex_lock(&dir_ui->ui_mutex); dir->i_size += sz_change; dir_ui->ui_size = dir->i_size; dir->i_mtime = dir->i_ctime = inode->i_ctime; err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0); if (err) goto out_cancel; mutex_unlock(&dir_ui->ui_mutex); insert_inode_hash(inode); d_instantiate(dentry, inode); err = 0; goto out_fname; out_cancel: dir->i_size -= sz_change; dir_ui->ui_size = dir->i_size; mutex_unlock(&dir_ui->ui_mutex); out_inode: /* Free inode->i_link before inode is marked as bad. */ fscrypt_free_inode(inode); make_bad_inode(inode); iput(inode); out_fname: fscrypt_free_filename(&nm); out_budg: ubifs_release_budget(c, &req); return err; } /** * lock_4_inodes - a wrapper for locking three UBIFS inodes. * @inode1: first inode * @inode2: second inode * @inode3: third inode * @inode4: fouth inode * * This function is used for 'ubifs_rename()' and @inode1 may be the same as * @inode2 whereas @inode3 and @inode4 may be %NULL. * * We do not implement any tricks to guarantee strict lock ordering, because * VFS has already done it for us on the @i_mutex. So this is just a simple * wrapper function. */ static void lock_4_inodes(struct inode *inode1, struct inode *inode2, struct inode *inode3, struct inode *inode4) { mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1); if (inode2 != inode1) mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2); if (inode3) mutex_lock_nested(&ubifs_inode(inode3)->ui_mutex, WB_MUTEX_3); if (inode4) mutex_lock_nested(&ubifs_inode(inode4)->ui_mutex, WB_MUTEX_4); } /** * unlock_4_inodes - a wrapper for unlocking three UBIFS inodes for rename. * @inode1: first inode * @inode2: second inode * @inode3: third inode * @inode4: fouth inode */ static void unlock_4_inodes(struct inode *inode1, struct inode *inode2, struct inode *inode3, struct inode *inode4) { if (inode4) mutex_unlock(&ubifs_inode(inode4)->ui_mutex); if (inode3) mutex_unlock(&ubifs_inode(inode3)->ui_mutex); if (inode1 != inode2) mutex_unlock(&ubifs_inode(inode2)->ui_mutex); mutex_unlock(&ubifs_inode(inode1)->ui_mutex); } static int do_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, unsigned int flags) { struct ubifs_info *c = old_dir->i_sb->s_fs_info; struct inode *old_inode = d_inode(old_dentry); struct inode *new_inode = d_inode(new_dentry); struct inode *whiteout = NULL; struct ubifs_inode *old_inode_ui = ubifs_inode(old_inode); struct ubifs_inode *whiteout_ui = NULL; int err, release, sync = 0, move = (new_dir != old_dir); int is_dir = S_ISDIR(old_inode->i_mode); int unlink = !!new_inode, new_sz, old_sz; struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1, .dirtied_ino = 3 }; struct ubifs_budget_req ino_req = { .dirtied_ino = 1, .dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) }; struct timespec64 time; unsigned int saved_nlink; struct fscrypt_name old_nm, new_nm; /* * Budget request settings: deletion direntry, new direntry, removing * the old inode, and changing old and new parent directory inodes. * * However, this operation also marks the target inode as dirty and * does not write it, so we allocate budget for the target inode * separately. */ dbg_gen("dent '%pd' ino %lu in dir ino %lu to dent '%pd' in dir ino %lu flags 0x%x", old_dentry, old_inode->i_ino, old_dir->i_ino, new_dentry, new_dir->i_ino, flags); if (unlink) { ubifs_assert(c, inode_is_locked(new_inode)); /* Budget for old inode's data when its nlink > 1. */ req.dirtied_ino_d = ALIGN(ubifs_inode(new_inode)->data_len, 8); err = ubifs_purge_xattrs(new_inode); if (err) return err; } if (unlink && is_dir) { err = ubifs_check_dir_empty(new_inode); if (err) return err; } err = fscrypt_setup_filename(old_dir, &old_dentry->d_name, 0, &old_nm); if (err) return err; err = fscrypt_setup_filename(new_dir, &new_dentry->d_name, 0, &new_nm); if (err) { fscrypt_free_filename(&old_nm); return err; } new_sz = CALC_DENT_SIZE(fname_len(&new_nm)); old_sz = CALC_DENT_SIZE(fname_len(&old_nm)); err = ubifs_budget_space(c, &req); if (err) { fscrypt_free_filename(&old_nm); fscrypt_free_filename(&new_nm); return err; } err = ubifs_budget_space(c, &ino_req); if (err) { fscrypt_free_filename(&old_nm); fscrypt_free_filename(&new_nm); ubifs_release_budget(c, &req); return err; } if (flags & RENAME_WHITEOUT) { union ubifs_dev_desc *dev = NULL; struct ubifs_budget_req wht_req; dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS); if (!dev) { err = -ENOMEM; goto out_release; } err = do_tmpfile(old_dir, old_dentry, S_IFCHR | WHITEOUT_MODE, &whiteout); if (err) { kfree(dev); goto out_release; } spin_lock(&whiteout->i_lock); whiteout->i_state |= I_LINKABLE; spin_unlock(&whiteout->i_lock); whiteout_ui = ubifs_inode(whiteout); whiteout_ui->data = dev; whiteout_ui->data_len = ubifs_encode_dev(dev, MKDEV(0, 0)); ubifs_assert(c, !whiteout_ui->dirty); memset(&wht_req, 0, sizeof(struct ubifs_budget_req)); wht_req.dirtied_ino = 1; wht_req.dirtied_ino_d = ALIGN(whiteout_ui->data_len, 8); /* * To avoid deadlock between space budget (holds ui_mutex and * waits wb work) and writeback work(waits ui_mutex), do space * budget before ubifs inodes locked. */ err = ubifs_budget_space(c, &wht_req); if (err) { iput(whiteout); goto out_release; } /* Add the old_dentry size to the old_dir size. */ old_sz -= CALC_DENT_SIZE(fname_len(&old_nm)); } lock_4_inodes(old_dir, new_dir, new_inode, whiteout); /* * Like most other Unix systems, set the @i_ctime for inodes on a * rename. */ time = current_time(old_dir); old_inode->i_ctime = time; /* We must adjust parent link count when renaming directories */ if (is_dir) { if (move) { /* * @old_dir loses a link because we are moving * @old_inode to a different directory. */ drop_nlink(old_dir); /* * @new_dir only gains a link if we are not also * overwriting an existing directory. */ if (!unlink) inc_nlink(new_dir); } else { /* * @old_inode is not moving to a different directory, * but @old_dir still loses a link if we are * overwriting an existing directory. */ if (unlink) drop_nlink(old_dir); } } old_dir->i_size -= old_sz; ubifs_inode(old_dir)->ui_size = old_dir->i_size; old_dir->i_mtime = old_dir->i_ctime = time; new_dir->i_mtime = new_dir->i_ctime = time; /* * And finally, if we unlinked a direntry which happened to have the * same name as the moved direntry, we have to decrement @i_nlink of * the unlinked inode and change its ctime. */ if (unlink) { /* * Directories cannot have hard-links, so if this is a * directory, just clear @i_nlink. */ saved_nlink = new_inode->i_nlink; if (is_dir) clear_nlink(new_inode); else drop_nlink(new_inode); new_inode->i_ctime = time; } else { new_dir->i_size += new_sz; ubifs_inode(new_dir)->ui_size = new_dir->i_size; } /* * Do not ask 'ubifs_jnl_rename()' to flush write-buffer if @old_inode * is dirty, because this will be done later on at the end of * 'ubifs_rename()'. */ if (IS_SYNC(old_inode)) { sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir); if (unlink && IS_SYNC(new_inode)) sync = 1; } if (whiteout) { inc_nlink(whiteout); mark_inode_dirty(whiteout); spin_lock(&whiteout->i_lock); whiteout->i_state &= ~I_LINKABLE; spin_unlock(&whiteout->i_lock); iput(whiteout); } err = ubifs_jnl_rename(c, old_dir, old_inode, &old_nm, new_dir, new_inode, &new_nm, whiteout, sync); if (err) goto out_cancel; unlock_4_inodes(old_dir, new_dir, new_inode, whiteout); ubifs_release_budget(c, &req); mutex_lock(&old_inode_ui->ui_mutex); release = old_inode_ui->dirty; mark_inode_dirty_sync(old_inode); mutex_unlock(&old_inode_ui->ui_mutex); if (release) ubifs_release_budget(c, &ino_req); if (IS_SYNC(old_inode)) err = old_inode->i_sb->s_op->write_inode(old_inode, NULL); fscrypt_free_filename(&old_nm); fscrypt_free_filename(&new_nm); return err; out_cancel: if (unlink) { set_nlink(new_inode, saved_nlink); } else { new_dir->i_size -= new_sz; ubifs_inode(new_dir)->ui_size = new_dir->i_size; } old_dir->i_size += old_sz; ubifs_inode(old_dir)->ui_size = old_dir->i_size; if (is_dir) { if (move) { inc_nlink(old_dir); if (!unlink) drop_nlink(new_dir); } else { if (unlink) inc_nlink(old_dir); } } if (whiteout) { drop_nlink(whiteout); iput(whiteout); } unlock_4_inodes(old_dir, new_dir, new_inode, whiteout); out_release: ubifs_release_budget(c, &ino_req); ubifs_release_budget(c, &req); fscrypt_free_filename(&old_nm); fscrypt_free_filename(&new_nm); return err; } static int ubifs_xrename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry) { struct ubifs_info *c = old_dir->i_sb->s_fs_info; struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1, .dirtied_ino = 2 }; int sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir); struct inode *fst_inode = d_inode(old_dentry); struct inode *snd_inode = d_inode(new_dentry); struct timespec64 time; int err; struct fscrypt_name fst_nm, snd_nm; ubifs_assert(c, fst_inode && snd_inode); err = fscrypt_setup_filename(old_dir, &old_dentry->d_name, 0, &fst_nm); if (err) return err; err = fscrypt_setup_filename(new_dir, &new_dentry->d_name, 0, &snd_nm); if (err) { fscrypt_free_filename(&fst_nm); return err; } err = ubifs_budget_space(c, &req); if (err) goto out; lock_4_inodes(old_dir, new_dir, NULL, NULL); time = current_time(old_dir); fst_inode->i_ctime = time; snd_inode->i_ctime = time; old_dir->i_mtime = old_dir->i_ctime = time; new_dir->i_mtime = new_dir->i_ctime = time; if (old_dir != new_dir) { if (S_ISDIR(fst_inode->i_mode) && !S_ISDIR(snd_inode->i_mode)) { inc_nlink(new_dir); drop_nlink(old_dir); } else if (!S_ISDIR(fst_inode->i_mode) && S_ISDIR(snd_inode->i_mode)) { drop_nlink(new_dir); inc_nlink(old_dir); } } err = ubifs_jnl_xrename(c, old_dir, fst_inode, &fst_nm, new_dir, snd_inode, &snd_nm, sync); unlock_4_inodes(old_dir, new_dir, NULL, NULL); ubifs_release_budget(c, &req); out: fscrypt_free_filename(&fst_nm); fscrypt_free_filename(&snd_nm); return err; } static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, unsigned int flags) { int err; struct ubifs_info *c = old_dir->i_sb->s_fs_info; if (flags & ~(RENAME_NOREPLACE | RENAME_WHITEOUT | RENAME_EXCHANGE)) return -EINVAL; ubifs_assert(c, inode_is_locked(old_dir)); ubifs_assert(c, inode_is_locked(new_dir)); err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry, flags); if (err) return err; if (flags & RENAME_EXCHANGE) return ubifs_xrename(old_dir, old_dentry, new_dir, new_dentry); return do_rename(old_dir, old_dentry, new_dir, new_dentry, flags); } int ubifs_getattr(const struct path *path, struct kstat *stat, u32 request_mask, unsigned int flags) { loff_t size; struct inode *inode = d_inode(path->dentry); struct ubifs_inode *ui = ubifs_inode(inode); mutex_lock(&ui->ui_mutex); if (ui->flags & UBIFS_APPEND_FL) stat->attributes |= STATX_ATTR_APPEND; if (ui->flags & UBIFS_COMPR_FL) stat->attributes |= STATX_ATTR_COMPRESSED; if (ui->flags & UBIFS_CRYPT_FL) stat->attributes |= STATX_ATTR_ENCRYPTED; if (ui->flags & UBIFS_IMMUTABLE_FL) stat->attributes |= STATX_ATTR_IMMUTABLE; stat->attributes_mask |= (STATX_ATTR_APPEND | STATX_ATTR_COMPRESSED | STATX_ATTR_ENCRYPTED | STATX_ATTR_IMMUTABLE); generic_fillattr(inode, stat); stat->blksize = UBIFS_BLOCK_SIZE; stat->size = ui->ui_size; /* * Unfortunately, the 'stat()' system call was designed for block * device based file systems, and it is not appropriate for UBIFS, * because UBIFS does not have notion of "block". For example, it is * difficult to tell how many block a directory takes - it actually * takes less than 300 bytes, but we have to round it to block size, * which introduces large mistake. This makes utilities like 'du' to * report completely senseless numbers. This is the reason why UBIFS * goes the same way as JFFS2 - it reports zero blocks for everything * but regular files, which makes more sense than reporting completely * wrong sizes. */ if (S_ISREG(inode->i_mode)) { size = ui->xattr_size; size += stat->size; size = ALIGN(size, UBIFS_BLOCK_SIZE); /* * Note, user-space expects 512-byte blocks count irrespectively * of what was reported in @stat->size. */ stat->blocks = size >> 9; } else stat->blocks = 0; mutex_unlock(&ui->ui_mutex); return 0; } const struct inode_operations ubifs_dir_inode_operations = { .lookup = ubifs_lookup, .create = ubifs_create, .link = ubifs_link, .symlink = ubifs_symlink, .unlink = ubifs_unlink, .mkdir = ubifs_mkdir, .rmdir = ubifs_rmdir, .mknod = ubifs_mknod, .rename = ubifs_rename, .setattr = ubifs_setattr, .getattr = ubifs_getattr, #ifdef CONFIG_UBIFS_FS_XATTR .listxattr = ubifs_listxattr, #endif .update_time = ubifs_update_time, .tmpfile = ubifs_tmpfile, }; const struct file_operations ubifs_dir_operations = { .llseek = generic_file_llseek, .release = ubifs_dir_release, .read = generic_read_dir, .iterate_shared = ubifs_readdir, .fsync = ubifs_fsync, .unlocked_ioctl = ubifs_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = ubifs_compat_ioctl, #endif };