- 根目录:
- fs
- ubifs
- dir.c
/* * 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;
/* Disable readahead */
inode->i_mapping->backing_dev_info = &c->bdi;
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("out of inode numbers");
make_bad_inode(inode);
iput(inode);
return ERR_PTR(-EINVAL);
}
ubifs_warn("running out of inode numbers (current %lu, max %d)",
(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("'%.*s' in dir ino %lu",
dentry->d_name.len, dentry->d_name.name, 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("dead directory entry '%.*s', error %d",
dentry->d_name.len, dentry->d_name.name, 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 '%.*s', mode %#hx in dir ino %lu",
dentry->d_name.len, dentry->d_name.name, 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;
}
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);
make_bad_inode(inode);
iput(inode);
out_budg:
ubifs_release_budget(c, &req);
ubifs_err("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, void *dirent, filldir_t filldir)
{
int err, over = 0;
loff_t pos = file->f_pos;
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, pos);
if (pos > UBIFS_S_KEY_HASH_MASK || 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 (pos == 0) {
ubifs_assert(!file->private_data);
over = filldir(dirent, ".", 1, 0, dir->i_ino, DT_DIR);
if (over)
return 0;
file->f_pos = pos = 1;
}
if (pos == 1) {
ubifs_assert(!file->private_data);
over = filldir(dirent, "..", 2, 1,
parent_ino(file->f_path.dentry), DT_DIR);
if (over)
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;
}
file->f_pos = 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 @pos or the closest one.
*/
dent_key_init_hash(c, &key, dir->i_ino, pos);
nm.name = NULL;
dent = ubifs_tnc_next_ent(c, &key, &nm);
if (IS_ERR(dent)) {
err = PTR_ERR(dent);
goto out;
}
file->f_pos = 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);
over = filldir(dirent, dent->name, nm.len, pos,
le64_to_cpu(dent->inum),
vfs_dent_type(dent->type));
if (over)
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);
file->f_pos = pos = key_hash_flash(c, &dent->key);
file->private_data = dent;
cond_resched();
if (file->f_version == 0)
/*
* The file was seek'ed meanwhile, lets return and start
* reading direntries from the new position on the next
* invocation.
*/
return 0;
}
out:
if (err != -ENOENT) {
ubifs_err("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 */
file->f_pos = 2;
return 0;
}
static loff_t ubifs_dir_llseek(struct file *file, loff_t offset, int whence)
{
return generic_file_llseek(file, offset, whence);
}
/* 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 = old_dentry->d_inode;
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 '%.*s' to ino %lu (nlink %d) in dir ino %lu",
dentry->d_name.len, dentry->d_name.name, 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 = dentry->d_inode;
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 '%.*s' from ino %lu (nlink %d) in dir ino %lu",
dentry->d_name.len, dentry->d_name.name, 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 = dentry->d_inode;
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 '%.*s', ino %lu in dir ino %lu", dentry->d_name.len,
dentry->d_name.name, 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, dentry->d_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);
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 '%.*s', mode %#hx in dir ino %lu",
dentry->d_name.len, dentry->d_name.name, 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;
}
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("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);
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 '%.*s' in dir ino %lu",
dentry->d_name.len, dentry->d_name.name, 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;
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);
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 '%.*s', target '%s' in dir ino %lu", dentry->d_name.len,
dentry->d_name.name, 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;
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 = old_dentry->d_inode;
struct inode *new_inode = new_dentry->d_inode;
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 '%.*s' ino %lu in dir ino %lu to dent '%.*s' in dir ino %lu",
old_dentry->d_name.len, old_dentry->d_name.name,
old_inode->i_ino, old_dir->i_ino, new_dentry->d_name.len,
new_dentry->d_name.name, 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 = dentry->d_inode;
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 = ubifs_dir_llseek,
.release = ubifs_dir_release,
.read = generic_read_dir,
.readdir = ubifs_readdir,
.fsync = ubifs_fsync,
.unlocked_ioctl = ubifs_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = ubifs_compat_ioctl,
#endif
};