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Diffstat (limited to 'ubifs-utils/libubifs/dir.c')
| -rw-r--r-- | ubifs-utils/libubifs/dir.c | 1744 |
1 files changed, 1744 insertions, 0 deletions
diff --git a/ubifs-utils/libubifs/dir.c b/ubifs-utils/libubifs/dir.c new file mode 100644 index 0000000..c77ea57 --- /dev/null +++ b/ubifs-utils/libubifs/dir.c @@ -0,0 +1,1744 @@ +// 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 + * @is_xattr: whether the inode is xattr inode + * + * This function finds an unused inode number, allocates new inode and + * initializes it. Non-xattr new inode may be written with xattrs(selinux/ + * encryption) before writing dentry, which could cause inconsistent problem + * when powercut happens between two operations. To deal with it, non-xattr + * new inode is initialized with zero-nlink and added into orphan list, caller + * should make sure that inode is relinked later, and make sure that orphan + * removing and journal writing into an committing atomic operation. 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, bool is_xattr) +{ + 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(&nop_mnt_idmap, inode, dir, mode); + simple_inode_init_ts(inode); + inode->i_mapping->nrpages = 0; + + if (!is_xattr) { + 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 (!is_xattr) { + set_nlink(inode, 0); + err = ubifs_add_orphan(c, inode->i_ino); + if (err) { + ubifs_err(c, "ubifs_add_orphan failed: %i", err); + goto out_iput; + } + down_read(&c->commit_sem); + ui->del_cmtno = c->cmt_no; + up_read(&c->commit_sem); + } + + if (encrypted) { + err = fscrypt_set_context(inode, NULL); + if (err) { + if (!is_xattr) { + set_nlink(inode, 1); + ubifs_delete_orphan(c, inode->i_ino); + } + 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); + 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 mnt_idmap *idmap, 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, false); + 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; + + set_nlink(inode, 1); + mutex_lock(&dir_ui->ui_mutex); + dir->i_size += sz_change; + dir_ui->ui_size = dir->i_size; + inode_set_mtime_to_ts(dir, + inode_set_ctime_to_ts(dir, inode_get_ctime(inode))); + err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0, 1); + 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); + set_nlink(inode, 0); +out_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 struct inode *create_whiteout(struct inode *dir, struct dentry *dentry) +{ + int err; + umode_t mode = S_IFCHR | WHITEOUT_MODE; + struct inode *inode; + struct ubifs_info *c = dir->i_sb->s_fs_info; + + /* + * Create an inode('nlink = 1') for whiteout without updating journal, + * let ubifs_jnl_rename() store it on flash to complete rename whiteout + * atomically. + */ + + dbg_gen("dent '%pd', mode %#hx in dir ino %lu", + dentry, mode, dir->i_ino); + + inode = ubifs_new_inode(c, dir, mode, false); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto out_free; + } + + 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; + + /* The dir size is updated by do_rename. */ + insert_inode_hash(inode); + + return inode; + +out_inode: + iput(inode); +out_free: + ubifs_err(c, "cannot create whiteout file, error %d", err); + return ERR_PTR(err); +} + +/** + * 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_tmpfile(struct mnt_idmap *idmap, struct inode *dir, + struct file *file, umode_t mode) +{ + struct dentry *dentry = file->f_path.dentry; + 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; + 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, false); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto out_budg; + } + ui = ubifs_inode(inode); + + err = ubifs_init_security(dir, inode, &dentry->d_name); + if (err) + goto out_inode; + + set_nlink(inode, 1); + mutex_lock(&ui->ui_mutex); + insert_inode_hash(inode); + d_tmpfile(file, inode); + ubifs_assert(c, ui->dirty); + + instantiated = 1; + mutex_unlock(&ui->ui_mutex); + + lock_2_inodes(dir, inode); + err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0, 1); + if (err) + goto out_cancel; + unlock_2_inodes(dir, inode); + + ubifs_release_budget(c, &req); + fscrypt_free_filename(&nm); + + return finish_open_simple(file, 0); + +out_cancel: + unlock_2_inodes(dir, inode); +out_inode: + if (!instantiated) + iput(inode); +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; +} + +/** + * 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; +} + +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; + 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; + + sz_change = CALC_DENT_SIZE(fname_len(&nm)); + + 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); + + inc_nlink(inode); + ihold(inode); + inode_set_ctime_current(inode); + dir->i_size += sz_change; + dir_ui->ui_size = dir->i_size; + inode_set_mtime_to_ts(dir, + inode_set_ctime_to_ts(dir, inode_get_ctime(inode))); + err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0, inode->i_nlink == 1); + 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); + 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_set_ctime_current(inode); + drop_nlink(inode); + dir->i_size -= sz_change; + dir_ui->ui_size = dir->i_size; + inode_set_mtime_to_ts(dir, + inode_set_ctime_to_ts(dir, inode_get_ctime(inode))); + err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0, 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; +} + +/** + * ubifs_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 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_set_ctime_current(inode); + clear_nlink(inode); + drop_nlink(dir); + dir->i_size -= sz_change; + dir_ui->ui_size = dir->i_size; + inode_set_mtime_to_ts(dir, + inode_set_ctime_to_ts(dir, inode_get_ctime(inode))); + err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0, 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 mnt_idmap *idmap, 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, false); + 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; + + set_nlink(inode, 1); + 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; + inode_set_mtime_to_ts(dir, + inode_set_ctime_to_ts(dir, inode_get_ctime(inode))); + err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0, 1); + 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); + set_nlink(inode, 0); +out_inode: + iput(inode); +out_fname: + fscrypt_free_filename(&nm); +out_budg: + ubifs_release_budget(c, &req); + return err; +} + +static int ubifs_mknod(struct mnt_idmap *idmap, 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, false); + if (IS_ERR(inode)) { + kfree(dev); + err = PTR_ERR(inode); + goto out_fname; + } + + err = ubifs_init_security(dir, inode, &dentry->d_name); + if (err) { + kfree(dev); + goto out_inode; + } + + 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; + set_nlink(inode, 1); + + mutex_lock(&dir_ui->ui_mutex); + dir->i_size += sz_change; + dir_ui->ui_size = dir->i_size; + inode_set_mtime_to_ts(dir, + inode_set_ctime_to_ts(dir, inode_get_ctime(inode))); + err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0, 1); + 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); + set_nlink(inode, 0); +out_inode: + iput(inode); +out_fname: + fscrypt_free_filename(&nm); +out_budg: + ubifs_release_budget(c, &req); + return err; +} + +static int ubifs_symlink(struct mnt_idmap *idmap, 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, false); + 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; + + 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; + set_nlink(inode, 1); + + mutex_lock(&dir_ui->ui_mutex); + dir->i_size += sz_change; + dir_ui->ui_size = dir->i_size; + inode_set_mtime_to_ts(dir, + inode_set_ctime_to_ts(dir, inode_get_ctime(inode))); + err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0, 1); + 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); + set_nlink(inode, 0); +out_inode: + /* Free inode->i_link before inode is marked as bad. */ + fscrypt_free_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: fourth 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: fourth 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 ubifs_budget_req wht_req; + unsigned int saved_nlink; + struct fscrypt_name old_nm, new_nm; + + /* + * Budget request settings: + * req: deletion direntry, new direntry, removing the old inode, + * and changing old and new parent directory inodes. + * + * wht_req: new whiteout inode for RENAME_WHITEOUT. + * + * ino_req: marks the target inode as dirty and does not write it. + */ + + 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; + + dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS); + if (!dev) { + err = -ENOMEM; + goto out_release; + } + + /* + * The whiteout inode without dentry is pinned in memory, + * umount won't happen during rename process because we + * got parent dentry. + */ + whiteout = create_whiteout(old_dir, old_dentry); + if (IS_ERR(whiteout)) { + err = PTR_ERR(whiteout); + kfree(dev); + goto out_release; + } + + 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.new_ino = 1; + wht_req.new_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; + } + set_nlink(whiteout, 1); + + /* 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. + */ + simple_rename_timestamp(old_dir, old_dentry, new_dir, new_dentry); + + /* 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; + + /* + * 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. + */ + 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); + } 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; + /* + * S_SYNC flag of whiteout inherits from the old_dir, and we + * have already checked the old dir inode. So there is no need + * to check whiteout. + */ + } + + err = ubifs_jnl_rename(c, old_dir, old_inode, &old_nm, new_dir, + new_inode, &new_nm, whiteout, sync, !!whiteout); + if (err) + goto out_cancel; + + unlock_4_inodes(old_dir, new_dir, new_inode, whiteout); + ubifs_release_budget(c, &req); + + if (whiteout) { + ubifs_release_budget(c, &wht_req); + iput(whiteout); + } + + 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)) + /* + * Rename finished here. Although old inode cannot be updated + * on flash, old ctime is not a big problem, don't return err + * code to userspace. + */ + old_inode->i_sb->s_op->write_inode(old_inode, NULL); + + fscrypt_free_filename(&old_nm); + fscrypt_free_filename(&new_nm); + return 0; + +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); + } + } + unlock_4_inodes(old_dir, new_dir, new_inode, whiteout); + if (whiteout) { + ubifs_release_budget(c, &wht_req); + set_nlink(whiteout, 0); + iput(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); + int err; + struct fscrypt_name fst_nm, snd_nm; + + ubifs_assert(c, fst_inode && snd_inode); + + /* + * Budget request settings: changing two direntries, changing the two + * parent directory inodes. + */ + + dbg_gen("dent '%pd' ino %lu in dir ino %lu exchange dent '%pd' ino %lu in dir ino %lu", + old_dentry, fst_inode->i_ino, old_dir->i_ino, + new_dentry, snd_inode->i_ino, new_dir->i_ino); + + 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); + + simple_rename_timestamp(old_dir, old_dentry, new_dir, new_dentry); + + 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 mnt_idmap *idmap, + 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(struct mnt_idmap *idmap, 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(&nop_mnt_idmap, request_mask, 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, + .listxattr = ubifs_listxattr, + .update_time = ubifs_update_time, + .tmpfile = ubifs_tmpfile, + .fileattr_get = ubifs_fileattr_get, + .fileattr_set = ubifs_fileattr_set, +}; + +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 +}; |