--- /dev/null
+/* * 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
+};
Code Review / kvmfornfv.git / blobdiff