diff options
Diffstat (limited to 'fs/ubifs/dir.c')
| -rw-r--r-- | fs/ubifs/dir.c | 1202 |
1 files changed, 1202 insertions, 0 deletions
diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c new file mode 100644 index 000000000..27060fc85 --- /dev/null +++ b/fs/ubifs/dir.c @@ -0,0 +1,1202 @@ +/* * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * Copyright (C) 2006, 2007 University of Szeged, Hungary + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program; if not, write to the Free Software Foundation, Inc., 51 + * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + * 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, const struct inode *dir, + umode_t mode) +{ + struct inode *inode; + struct ubifs_inode *ui; + + 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 = + ubifs_current_time(inode); + inode->i_mapping->nrpages = 0; + + 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"); + make_bad_inode(inode); + iput(inode); + return ERR_PTR(-EINVAL); + } + 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); + return inode; +} + +static int dbg_check_name(const struct ubifs_info *c, + const struct ubifs_dent_node *dent, + const struct qstr *nm) +{ + if (!dbg_is_chk_gen(c)) + return 0; + if (le16_to_cpu(dent->nlen) != nm->len) + return -EINVAL; + if (memcmp(dent->name, nm->name, nm->len)) + 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; + struct ubifs_info *c = dir->i_sb->s_fs_info; + + dbg_gen("'%pd' in dir ino %lu", dentry, dir->i_ino); + + if (dentry->d_name.len > UBIFS_MAX_NLEN) + return ERR_PTR(-ENAMETOOLONG); + + dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS); + if (!dent) + return ERR_PTR(-ENOMEM); + + dent_key_init(c, &key, dir->i_ino, &dentry->d_name); + + err = ubifs_tnc_lookup_nm(c, &key, dent, &dentry->d_name); + if (err) { + if (err == -ENOENT) { + dbg_gen("not found"); + goto done; + } + goto out; + } + + if (dbg_check_name(c, dent, &dentry->d_name)) { + err = -EINVAL; + goto out; + } + + 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 out; + } + +done: + kfree(dent); + /* + * Note, d_splice_alias() would be required instead if we supported + * NFS. + */ + d_add(dentry, inode); + return NULL; + +out: + kfree(dent); + return ERR_PTR(err); +} + +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; + int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len); + struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, + .dirtied_ino = 1 }; + struct ubifs_inode *dir_ui = ubifs_inode(dir); + + /* + * 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; + + inode = ubifs_new_inode(c, dir, mode); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto out_budg; + } + + 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, &dentry->d_name, 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); + 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_budg: + ubifs_release_budget(c, &req); + ubifs_err(c, "cannot create regular 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 err; + struct qstr nm; + 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; + + 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 (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(!file->private_data); + if (!dir_emit_dots(file, ctx)) + return 0; + + /* Find the first entry in TNC and save it */ + lowest_dent_key(c, &key, dir->i_ino); + nm.name = NULL; + 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); + nm.name = NULL; + 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("feed '%s', ino %llu, new f_pos %#x", + dent->name, (unsigned long long)le64_to_cpu(dent->inum), + key_hash_flash(c, &dent->key)); + ubifs_assert(le64_to_cpu(dent->ch.sqnum) > + ubifs_inode(dir)->creat_sqnum); + + nm.len = le16_to_cpu(dent->nlen); + if (!dir_emit(ctx, dent->name, nm.len, + le64_to_cpu(dent->inum), + vfs_dent_type(dent->type))) + return 0; + + /* Switch to the next entry */ + key_read(c, &dent->key, &key); + nm.name = dent->name; + 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: + if (err != -ENOENT) { + ubifs_err(c, "cannot find next direntry, error %d", err); + return err; + } + + kfree(file->private_data); + file->private_data = NULL; + /* 2 is a special value indicating that there are no more direntries */ + ctx->pos = 2; + return 0; +} + +/* 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) }; + + /* + * 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(mutex_is_locked(&dir->i_mutex)); + ubifs_assert(mutex_is_locked(&inode->i_mutex)); + + err = dbg_check_synced_i_size(c, inode); + if (err) + return err; + + err = ubifs_budget_space(c, &req); + if (err) + return err; + + lock_2_inodes(dir, inode); + inc_nlink(inode); + ihold(inode); + inode->i_ctime = ubifs_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, &dentry->d_name, inode, 0, 0); + if (err) + goto out_cancel; + unlock_2_inodes(dir, inode); + + ubifs_release_budget(c, &req); + d_instantiate(dentry, inode); + 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); + 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 sz_change = CALC_DENT_SIZE(dentry->d_name.len); + int err, budgeted = 1; + struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 }; + unsigned int saved_nlink = inode->i_nlink; + + /* + * 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); + ubifs_assert(mutex_is_locked(&dir->i_mutex)); + ubifs_assert(mutex_is_locked(&inode->i_mutex)); + err = dbg_check_synced_i_size(c, inode); + if (err) + return err; + + err = ubifs_budget_space(c, &req); + if (err) { + if (err != -ENOSPC) + return err; + budgeted = 0; + } + + lock_2_inodes(dir, inode); + inode->i_ctime = ubifs_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, &dentry->d_name, 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(); + } + 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); + return err; +} + +/** + * check_dir_empty - check if a directory is empty or not. + * @c: UBIFS file-system description object + * @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. + */ +static int check_dir_empty(struct ubifs_info *c, struct inode *dir) +{ + struct qstr nm = { .name = NULL }; + 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 sz_change = CALC_DENT_SIZE(dentry->d_name.len); + int err, budgeted = 1; + struct ubifs_inode *dir_ui = ubifs_inode(dir); + struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 }; + + /* + * 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(mutex_is_locked(&dir->i_mutex)); + ubifs_assert(mutex_is_locked(&inode->i_mutex)); + err = check_dir_empty(c, d_inode(dentry)); + if (err) + return err; + + err = ubifs_budget_space(c, &req); + if (err) { + if (err != -ENOSPC) + return err; + budgeted = 0; + } + + lock_2_inodes(dir, inode); + inode->i_ctime = ubifs_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, &dentry->d_name, 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(); + } + 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); + 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 = CALC_DENT_SIZE(dentry->d_name.len); + struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1 }; + + /* + * 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; + + inode = ubifs_new_inode(c, dir, S_IFDIR | mode); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto out_budg; + } + + 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, &dentry->d_name, 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); + 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_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 = CALC_DENT_SIZE(dentry->d_name.len); + int err, devlen = 0; + struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, + .new_ino_d = ALIGN(devlen, 8), + .dirtied_ino = 1 }; + + /* + * 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 (!new_valid_dev(rdev)) + return -EINVAL; + + 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); + } + + err = ubifs_budget_space(c, &req); + if (err) { + kfree(dev); + return err; + } + + inode = ubifs_new_inode(c, dir, mode); + if (IS_ERR(inode)) { + kfree(dev); + err = PTR_ERR(inode); + goto out_budg; + } + + 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, &dentry->d_name, 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); + 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_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, len = strlen(symname); + int sz_change = CALC_DENT_SIZE(dentry->d_name.len); + struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, + .new_ino_d = ALIGN(len, 8), + .dirtied_ino = 1 }; + + /* + * Budget request settings: new inode, new direntry and changing parent + * directory inode. + */ + + dbg_gen("dent '%pd', target '%s' in dir ino %lu", dentry, + symname, dir->i_ino); + + if (len > UBIFS_MAX_INO_DATA) + return -ENAMETOOLONG; + + err = ubifs_budget_space(c, &req); + if (err) + return err; + + inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto out_budg; + } + + ui = ubifs_inode(inode); + ui->data = kmalloc(len + 1, GFP_NOFS); + if (!ui->data) { + err = -ENOMEM; + goto out_inode; + } + + memcpy(ui->data, symname, len); + ((char *)ui->data)[len] = '\0'; + /* + * 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 @len, not @len + %1. + */ + ui->data_len = len; + inode->i_size = ubifs_inode(inode)->ui_size = len; + + 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, &dentry->d_name, 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); + 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_budg: + ubifs_release_budget(c, &req); + return err; +} + +/** + * lock_3_inodes - a wrapper for locking three UBIFS inodes. + * @inode1: first inode + * @inode2: second inode + * @inode3: third inode + * + * This function is used for 'ubifs_rename()' and @inode1 may be the same as + * @inode2 whereas @inode3 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_3_inodes(struct inode *inode1, struct inode *inode2, + struct inode *inode3) +{ + 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); +} + +/** + * unlock_3_inodes - a wrapper for unlocking three UBIFS inodes for rename. + * @inode1: first inode + * @inode2: second inode + * @inode3: third inode + */ +static void unlock_3_inodes(struct inode *inode1, struct inode *inode2, + struct inode *inode3) +{ + 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 ubifs_rename(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 inode *old_inode = d_inode(old_dentry); + struct inode *new_inode = d_inode(new_dentry); + struct ubifs_inode *old_inode_ui = ubifs_inode(old_inode); + int err, release, sync = 0, move = (new_dir != old_dir); + int is_dir = S_ISDIR(old_inode->i_mode); + int unlink = !!new_inode; + int new_sz = CALC_DENT_SIZE(new_dentry->d_name.len); + int old_sz = CALC_DENT_SIZE(old_dentry->d_name.len); + 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 timespec time; + unsigned int uninitialized_var(saved_nlink); + + /* + * 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", + old_dentry, old_inode->i_ino, old_dir->i_ino, + new_dentry, new_dir->i_ino); + ubifs_assert(mutex_is_locked(&old_dir->i_mutex)); + ubifs_assert(mutex_is_locked(&new_dir->i_mutex)); + if (unlink) + ubifs_assert(mutex_is_locked(&new_inode->i_mutex)); + + + if (unlink && is_dir) { + err = check_dir_empty(c, new_inode); + if (err) + return err; + } + + err = ubifs_budget_space(c, &req); + if (err) + return err; + err = ubifs_budget_space(c, &ino_req); + if (err) { + ubifs_release_budget(c, &req); + return err; + } + + lock_3_inodes(old_dir, new_dir, new_inode); + + /* + * Like most other Unix systems, set the @i_ctime for inodes on a + * rename. + */ + time = ubifs_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; + } + err = ubifs_jnl_rename(c, old_dir, old_dentry, new_dir, new_dentry, + sync); + if (err) + goto out_cancel; + + unlock_3_inodes(old_dir, new_dir, new_inode); + 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); + 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); + } + } + unlock_3_inodes(old_dir, new_dir, new_inode); + ubifs_release_budget(c, &ino_req); + ubifs_release_budget(c, &req); + return err; +} + +int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry, + struct kstat *stat) +{ + loff_t size; + struct inode *inode = d_inode(dentry); + struct ubifs_inode *ui = ubifs_inode(inode); + + mutex_lock(&ui->ui_mutex); + 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, + .setxattr = ubifs_setxattr, + .getxattr = ubifs_getxattr, + .listxattr = ubifs_listxattr, + .removexattr = ubifs_removexattr, +}; + +const struct file_operations ubifs_dir_operations = { + .llseek = generic_file_llseek, + .release = ubifs_dir_release, + .read = generic_read_dir, + .iterate = ubifs_readdir, + .fsync = ubifs_fsync, + .unlocked_ioctl = ubifs_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = ubifs_compat_ioctl, +#endif +}; |