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dir.c
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dir.c
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// SPDX-License-Identifier: GPL-2.0-only
/* * This file is part of UBIFS.
*
* Copyright (C) 2006-2008 Nokia Corporation.
* Copyright (C) 2006, 2007 University of Szeged, Hungary
*
* Authors: Artem Bityutskiy (Битюцкий Артём)
* Adrian Hunter
* Zoltan Sogor
*/
/*
* This file implements directory operations.
*
* All FS operations in this file allocate budget before writing anything to the
* media. If they fail to allocate it, the error is returned. The only
* exceptions are 'ubifs_unlink()' and 'ubifs_rmdir()' which keep working even
* if they unable to allocate the budget, because deletion %-ENOSPC failure is
* not what users are usually ready to get. UBIFS budgeting subsystem has some
* space reserved for these purposes.
*
* All operations in this file write all inodes which they change straight
* away, instead of marking them dirty. For example, 'ubifs_link()' changes
* @i_size of the parent inode and writes the parent inode together with the
* target inode. This was done to simplify file-system recovery which would
* otherwise be very difficult to do. The only exception is rename which marks
* the re-named inode dirty (because its @i_ctime is updated) but does not
* write it, but just marks it as dirty.
*/
#include "ubifs.h"
/**
* inherit_flags - inherit flags of the parent inode.
* @dir: parent inode
* @mode: new inode mode flags
*
* This is a helper function for 'ubifs_new_inode()' which inherits flag of the
* parent directory inode @dir. UBIFS inodes inherit the following flags:
* o %UBIFS_COMPR_FL, which is useful to switch compression on/of on
* sub-directory basis;
* o %UBIFS_SYNC_FL - useful for the same reasons;
* o %UBIFS_DIRSYNC_FL - similar, but relevant only to directories.
*
* This function returns the inherited flags.
*/
static int inherit_flags(const struct inode *dir, umode_t mode)
{
int flags;
const struct ubifs_inode *ui = ubifs_inode(dir);
if (!S_ISDIR(dir->i_mode))
/*
* The parent is not a directory, which means that an extended
* attribute inode is being created. No flags.
*/
return 0;
flags = ui->flags & (UBIFS_COMPR_FL | UBIFS_SYNC_FL | UBIFS_DIRSYNC_FL);
if (!S_ISDIR(mode))
/* The "DIRSYNC" flag only applies to directories */
flags &= ~UBIFS_DIRSYNC_FL;
return flags;
}
/**
* ubifs_new_inode - allocate new UBIFS inode object.
* @c: UBIFS file-system description object
* @dir: parent directory inode
* @mode: inode mode flags
*
* This function finds an unused inode number, allocates new inode and
* initializes it. Returns new inode in case of success and an error code in
* case of failure.
*/
struct inode *ubifs_new_inode(struct ubifs_info *c, struct inode *dir,
umode_t mode)
{
int err;
struct inode *inode;
struct ubifs_inode *ui;
bool encrypted = false;
inode = new_inode(c->vfs_sb);
ui = ubifs_inode(inode);
if (!inode)
return ERR_PTR(-ENOMEM);
/*
* Set 'S_NOCMTIME' to prevent VFS form updating [mc]time of inodes and
* marking them dirty in file write path (see 'file_update_time()').
* UBIFS has to fully control "clean <-> dirty" transitions of inodes
* to make budgeting work.
*/
inode->i_flags |= S_NOCMTIME;
inode_init_owner(&init_user_ns, inode, dir, mode);
inode->i_mtime = inode->i_atime = inode->i_ctime =
current_time(inode);
inode->i_mapping->nrpages = 0;
err = fscrypt_prepare_new_inode(dir, inode, &encrypted);
if (err) {
ubifs_err(c, "fscrypt_prepare_new_inode failed: %i", err);
goto out_iput;
}
switch (mode & S_IFMT) {
case S_IFREG:
inode->i_mapping->a_ops = &ubifs_file_address_operations;
inode->i_op = &ubifs_file_inode_operations;
inode->i_fop = &ubifs_file_operations;
break;
case S_IFDIR:
inode->i_op = &ubifs_dir_inode_operations;
inode->i_fop = &ubifs_dir_operations;
inode->i_size = ui->ui_size = UBIFS_INO_NODE_SZ;
break;
case S_IFLNK:
inode->i_op = &ubifs_symlink_inode_operations;
break;
case S_IFSOCK:
case S_IFIFO:
case S_IFBLK:
case S_IFCHR:
inode->i_op = &ubifs_file_inode_operations;
break;
default:
BUG();
}
ui->flags = inherit_flags(dir, mode);
ubifs_set_inode_flags(inode);
if (S_ISREG(mode))
ui->compr_type = c->default_compr;
else
ui->compr_type = UBIFS_COMPR_NONE;
ui->synced_i_size = 0;
spin_lock(&c->cnt_lock);
/* Inode number overflow is currently not supported */
if (c->highest_inum >= INUM_WARN_WATERMARK) {
if (c->highest_inum >= INUM_WATERMARK) {
spin_unlock(&c->cnt_lock);
ubifs_err(c, "out of inode numbers");
err = -EINVAL;
goto out_iput;
}
ubifs_warn(c, "running out of inode numbers (current %lu, max %u)",
(unsigned long)c->highest_inum, INUM_WATERMARK);
}
inode->i_ino = ++c->highest_inum;
/*
* The creation sequence number remains with this inode for its
* lifetime. All nodes for this inode have a greater sequence number,
* and so it is possible to distinguish obsolete nodes belonging to a
* previous incarnation of the same inode number - for example, for the
* purpose of rebuilding the index.
*/
ui->creat_sqnum = ++c->max_sqnum;
spin_unlock(&c->cnt_lock);
if (encrypted) {
err = fscrypt_set_context(inode, NULL);
if (err) {
ubifs_err(c, "fscrypt_set_context failed: %i", err);
goto out_iput;
}
}
return inode;
out_iput:
make_bad_inode(inode);
iput(inode);
return ERR_PTR(err);
}
static int dbg_check_name(const struct ubifs_info *c,
const struct ubifs_dent_node *dent,
const struct fscrypt_name *nm)
{
if (!dbg_is_chk_gen(c))
return 0;
if (le16_to_cpu(dent->nlen) != fname_len(nm))
return -EINVAL;
if (memcmp(dent->name, fname_name(nm), fname_len(nm)))
return -EINVAL;
return 0;
}
static struct dentry *ubifs_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
int err;
union ubifs_key key;
struct inode *inode = NULL;
struct ubifs_dent_node *dent = NULL;
struct ubifs_info *c = dir->i_sb->s_fs_info;
struct fscrypt_name nm;
dbg_gen("'%pd' in dir ino %lu", dentry, dir->i_ino);
err = fscrypt_prepare_lookup(dir, dentry, &nm);
generic_set_encrypted_ci_d_ops(dentry);
if (err == -ENOENT)
return d_splice_alias(NULL, dentry);
if (err)
return ERR_PTR(err);
if (fname_len(&nm) > UBIFS_MAX_NLEN) {
inode = ERR_PTR(-ENAMETOOLONG);
goto done;
}
dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS);
if (!dent) {
inode = ERR_PTR(-ENOMEM);
goto done;
}
if (fname_name(&nm) == NULL) {
if (nm.hash & ~UBIFS_S_KEY_HASH_MASK)
goto done; /* ENOENT */
dent_key_init_hash(c, &key, dir->i_ino, nm.hash);
err = ubifs_tnc_lookup_dh(c, &key, dent, nm.minor_hash);
} else {
dent_key_init(c, &key, dir->i_ino, &nm);
err = ubifs_tnc_lookup_nm(c, &key, dent, &nm);
}
if (err) {
if (err == -ENOENT)
dbg_gen("not found");
else
inode = ERR_PTR(err);
goto done;
}
if (dbg_check_name(c, dent, &nm)) {
inode = ERR_PTR(-EINVAL);
goto done;
}
inode = ubifs_iget(dir->i_sb, le64_to_cpu(dent->inum));
if (IS_ERR(inode)) {
/*
* This should not happen. Probably the file-system needs
* checking.
*/
err = PTR_ERR(inode);
ubifs_err(c, "dead directory entry '%pd', error %d",
dentry, err);
ubifs_ro_mode(c, err);
goto done;
}
if (IS_ENCRYPTED(dir) &&
(S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
!fscrypt_has_permitted_context(dir, inode)) {
ubifs_warn(c, "Inconsistent encryption contexts: %lu/%lu",
dir->i_ino, inode->i_ino);
iput(inode);
inode = ERR_PTR(-EPERM);
}
done:
kfree(dent);
fscrypt_free_filename(&nm);
return d_splice_alias(inode, dentry);
}
static int ubifs_prepare_create(struct inode *dir, struct dentry *dentry,
struct fscrypt_name *nm)
{
if (fscrypt_is_nokey_name(dentry))
return -ENOKEY;
return fscrypt_setup_filename(dir, &dentry->d_name, 0, nm);
}
static int ubifs_create(struct user_namespace *mnt_userns, struct inode *dir,
struct dentry *dentry, umode_t mode, bool excl)
{
struct inode *inode;
struct ubifs_info *c = dir->i_sb->s_fs_info;
struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
.dirtied_ino = 1 };
struct ubifs_inode *dir_ui = ubifs_inode(dir);
struct fscrypt_name nm;
int err, sz_change;
/*
* Budget request settings: new inode, new direntry, changing the
* parent directory inode.
*/
dbg_gen("dent '%pd', mode %#hx in dir ino %lu",
dentry, mode, dir->i_ino);
err = ubifs_budget_space(c, &req);
if (err)
return err;
err = ubifs_prepare_create(dir, dentry, &nm);
if (err)
goto out_budg;
sz_change = CALC_DENT_SIZE(fname_len(&nm));
inode = ubifs_new_inode(c, dir, mode);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_fname;
}
err = ubifs_init_security(dir, inode, &dentry->d_name);
if (err)
goto out_inode;
mutex_lock(&dir_ui->ui_mutex);
dir->i_size += sz_change;
dir_ui->ui_size = dir->i_size;
dir->i_mtime = dir->i_ctime = inode->i_ctime;
err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0);
if (err)
goto out_cancel;
mutex_unlock(&dir_ui->ui_mutex);
ubifs_release_budget(c, &req);
fscrypt_free_filename(&nm);
insert_inode_hash(inode);
d_instantiate(dentry, inode);
return 0;
out_cancel:
dir->i_size -= sz_change;
dir_ui->ui_size = dir->i_size;
mutex_unlock(&dir_ui->ui_mutex);
out_inode:
make_bad_inode(inode);
iput(inode);
out_fname:
fscrypt_free_filename(&nm);
out_budg:
ubifs_release_budget(c, &req);
ubifs_err(c, "cannot create regular file, error %d", err);
return err;
}
static int do_tmpfile(struct inode *dir, struct dentry *dentry,
umode_t mode, struct inode **whiteout)
{
struct inode *inode;
struct ubifs_info *c = dir->i_sb->s_fs_info;
struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1};
struct ubifs_budget_req ino_req = { .dirtied_ino = 1 };
struct ubifs_inode *ui, *dir_ui = ubifs_inode(dir);
int err, instantiated = 0;
struct fscrypt_name nm;
/*
* Budget request settings: new dirty inode, new direntry,
* budget for dirtied inode will be released via writeback.
*/
dbg_gen("dent '%pd', mode %#hx in dir ino %lu",
dentry, mode, dir->i_ino);
err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
if (err)
return err;
err = ubifs_budget_space(c, &req);
if (err) {
fscrypt_free_filename(&nm);
return err;
}
err = ubifs_budget_space(c, &ino_req);
if (err) {
ubifs_release_budget(c, &req);
fscrypt_free_filename(&nm);
return err;
}
inode = ubifs_new_inode(c, dir, mode);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_budg;
}
ui = ubifs_inode(inode);
if (whiteout) {
init_special_inode(inode, inode->i_mode, WHITEOUT_DEV);
ubifs_assert(c, inode->i_op == &ubifs_file_inode_operations);
}
err = ubifs_init_security(dir, inode, &dentry->d_name);
if (err)
goto out_inode;
mutex_lock(&ui->ui_mutex);
insert_inode_hash(inode);
if (whiteout) {
mark_inode_dirty(inode);
drop_nlink(inode);
*whiteout = inode;
} else {
d_tmpfile(dentry, inode);
}
ubifs_assert(c, ui->dirty);
instantiated = 1;
mutex_unlock(&ui->ui_mutex);
mutex_lock(&dir_ui->ui_mutex);
err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0);
if (err)
goto out_cancel;
mutex_unlock(&dir_ui->ui_mutex);
ubifs_release_budget(c, &req);
return 0;
out_cancel:
mutex_unlock(&dir_ui->ui_mutex);
out_inode:
make_bad_inode(inode);
if (!instantiated)
iput(inode);
out_budg:
ubifs_release_budget(c, &req);
if (!instantiated)
ubifs_release_budget(c, &ino_req);
fscrypt_free_filename(&nm);
ubifs_err(c, "cannot create temporary file, error %d", err);
return err;
}
static int ubifs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
struct dentry *dentry, umode_t mode)
{
return do_tmpfile(dir, dentry, mode, NULL);
}
/**
* vfs_dent_type - get VFS directory entry type.
* @type: UBIFS directory entry type
*
* This function converts UBIFS directory entry type into VFS directory entry
* type.
*/
static unsigned int vfs_dent_type(uint8_t type)
{
switch (type) {
case UBIFS_ITYPE_REG:
return DT_REG;
case UBIFS_ITYPE_DIR:
return DT_DIR;
case UBIFS_ITYPE_LNK:
return DT_LNK;
case UBIFS_ITYPE_BLK:
return DT_BLK;
case UBIFS_ITYPE_CHR:
return DT_CHR;
case UBIFS_ITYPE_FIFO:
return DT_FIFO;
case UBIFS_ITYPE_SOCK:
return DT_SOCK;
default:
BUG();
}
return 0;
}
/*
* The classical Unix view for directory is that it is a linear array of
* (name, inode number) entries. Linux/VFS assumes this model as well.
* Particularly, 'readdir()' call wants us to return a directory entry offset
* which later may be used to continue 'readdir()'ing the directory or to
* 'seek()' to that specific direntry. Obviously UBIFS does not really fit this
* model because directory entries are identified by keys, which may collide.
*
* UBIFS uses directory entry hash value for directory offsets, so
* 'seekdir()'/'telldir()' may not always work because of possible key
* collisions. But UBIFS guarantees that consecutive 'readdir()' calls work
* properly by means of saving full directory entry name in the private field
* of the file description object.
*
* This means that UBIFS cannot support NFS which requires full
* 'seekdir()'/'telldir()' support.
*/
static int ubifs_readdir(struct file *file, struct dir_context *ctx)
{
int fstr_real_len = 0, err = 0;
struct fscrypt_name nm;
struct fscrypt_str fstr = {0};
union ubifs_key key;
struct ubifs_dent_node *dent;
struct inode *dir = file_inode(file);
struct ubifs_info *c = dir->i_sb->s_fs_info;
bool encrypted = IS_ENCRYPTED(dir);
dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, ctx->pos);
if (ctx->pos > UBIFS_S_KEY_HASH_MASK || ctx->pos == 2)
/*
* The directory was seek'ed to a senseless position or there
* are no more entries.
*/
return 0;
if (encrypted) {
err = fscrypt_prepare_readdir(dir);
if (err)
return err;
err = fscrypt_fname_alloc_buffer(UBIFS_MAX_NLEN, &fstr);
if (err)
return err;
fstr_real_len = fstr.len;
}
if (file->f_version == 0) {
/*
* The file was seek'ed, which means that @file->private_data
* is now invalid. This may also be just the first
* 'ubifs_readdir()' invocation, in which case
* @file->private_data is NULL, and the below code is
* basically a no-op.
*/
kfree(file->private_data);
file->private_data = NULL;
}
/*
* 'generic_file_llseek()' unconditionally sets @file->f_version to
* zero, and we use this for detecting whether the file was seek'ed.
*/
file->f_version = 1;
/* File positions 0 and 1 correspond to "." and ".." */
if (ctx->pos < 2) {
ubifs_assert(c, !file->private_data);
if (!dir_emit_dots(file, ctx)) {
if (encrypted)
fscrypt_fname_free_buffer(&fstr);
return 0;
}
/* Find the first entry in TNC and save it */
lowest_dent_key(c, &key, dir->i_ino);
fname_len(&nm) = 0;
dent = ubifs_tnc_next_ent(c, &key, &nm);
if (IS_ERR(dent)) {
err = PTR_ERR(dent);
goto out;
}
ctx->pos = key_hash_flash(c, &dent->key);
file->private_data = dent;
}
dent = file->private_data;
if (!dent) {
/*
* The directory was seek'ed to and is now readdir'ed.
* Find the entry corresponding to @ctx->pos or the closest one.
*/
dent_key_init_hash(c, &key, dir->i_ino, ctx->pos);
fname_len(&nm) = 0;
dent = ubifs_tnc_next_ent(c, &key, &nm);
if (IS_ERR(dent)) {
err = PTR_ERR(dent);
goto out;
}
ctx->pos = key_hash_flash(c, &dent->key);
file->private_data = dent;
}
while (1) {
dbg_gen("ino %llu, new f_pos %#x",
(unsigned long long)le64_to_cpu(dent->inum),
key_hash_flash(c, &dent->key));
ubifs_assert(c, le64_to_cpu(dent->ch.sqnum) >
ubifs_inode(dir)->creat_sqnum);
fname_len(&nm) = le16_to_cpu(dent->nlen);
fname_name(&nm) = dent->name;
if (encrypted) {
fstr.len = fstr_real_len;
err = fscrypt_fname_disk_to_usr(dir, key_hash_flash(c,
&dent->key),
le32_to_cpu(dent->cookie),
&nm.disk_name, &fstr);
if (err)
goto out;
} else {
fstr.len = fname_len(&nm);
fstr.name = fname_name(&nm);
}
if (!dir_emit(ctx, fstr.name, fstr.len,
le64_to_cpu(dent->inum),
vfs_dent_type(dent->type))) {
if (encrypted)
fscrypt_fname_free_buffer(&fstr);
return 0;
}
/* Switch to the next entry */
key_read(c, &dent->key, &key);
dent = ubifs_tnc_next_ent(c, &key, &nm);
if (IS_ERR(dent)) {
err = PTR_ERR(dent);
goto out;
}
kfree(file->private_data);
ctx->pos = key_hash_flash(c, &dent->key);
file->private_data = dent;
cond_resched();
}
out:
kfree(file->private_data);
file->private_data = NULL;
if (encrypted)
fscrypt_fname_free_buffer(&fstr);
if (err != -ENOENT)
ubifs_err(c, "cannot find next direntry, error %d", err);
else
/*
* -ENOENT is a non-fatal error in this context, the TNC uses
* it to indicate that the cursor moved past the current directory
* and readdir() has to stop.
*/
err = 0;
/* 2 is a special value indicating that there are no more direntries */
ctx->pos = 2;
return err;
}
/* Free saved readdir() state when the directory is closed */
static int ubifs_dir_release(struct inode *dir, struct file *file)
{
kfree(file->private_data);
file->private_data = NULL;
return 0;
}
/**
* lock_2_inodes - a wrapper for locking two UBIFS inodes.
* @inode1: first inode
* @inode2: second inode
*
* We do not implement any tricks to guarantee strict lock ordering, because
* VFS has already done it for us on the @i_mutex. So this is just a simple
* wrapper function.
*/
static void lock_2_inodes(struct inode *inode1, struct inode *inode2)
{
mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
}
/**
* unlock_2_inodes - a wrapper for unlocking two UBIFS inodes.
* @inode1: first inode
* @inode2: second inode
*/
static void unlock_2_inodes(struct inode *inode1, struct inode *inode2)
{
mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
}
static int ubifs_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *dentry)
{
struct ubifs_info *c = dir->i_sb->s_fs_info;
struct inode *inode = d_inode(old_dentry);
struct ubifs_inode *ui = ubifs_inode(inode);
struct ubifs_inode *dir_ui = ubifs_inode(dir);
int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
struct ubifs_budget_req req = { .new_dent = 1, .dirtied_ino = 2,
.dirtied_ino_d = ALIGN(ui->data_len, 8) };
struct fscrypt_name nm;
/*
* Budget request settings: new direntry, changing the target inode,
* changing the parent inode.
*/
dbg_gen("dent '%pd' to ino %lu (nlink %d) in dir ino %lu",
dentry, inode->i_ino,
inode->i_nlink, dir->i_ino);
ubifs_assert(c, inode_is_locked(dir));
ubifs_assert(c, inode_is_locked(inode));
err = fscrypt_prepare_link(old_dentry, dir, dentry);
if (err)
return err;
err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
if (err)
return err;
err = dbg_check_synced_i_size(c, inode);
if (err)
goto out_fname;
err = ubifs_budget_space(c, &req);
if (err)
goto out_fname;
lock_2_inodes(dir, inode);
/* Handle O_TMPFILE corner case, it is allowed to link a O_TMPFILE. */
if (inode->i_nlink == 0)
ubifs_delete_orphan(c, inode->i_ino);
inc_nlink(inode);
ihold(inode);
inode->i_ctime = current_time(inode);
dir->i_size += sz_change;
dir_ui->ui_size = dir->i_size;
dir->i_mtime = dir->i_ctime = inode->i_ctime;
err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0);
if (err)
goto out_cancel;
unlock_2_inodes(dir, inode);
ubifs_release_budget(c, &req);
d_instantiate(dentry, inode);
fscrypt_free_filename(&nm);
return 0;
out_cancel:
dir->i_size -= sz_change;
dir_ui->ui_size = dir->i_size;
drop_nlink(inode);
if (inode->i_nlink == 0)
ubifs_add_orphan(c, inode->i_ino);
unlock_2_inodes(dir, inode);
ubifs_release_budget(c, &req);
iput(inode);
out_fname:
fscrypt_free_filename(&nm);
return err;
}
static int ubifs_unlink(struct inode *dir, struct dentry *dentry)
{
struct ubifs_info *c = dir->i_sb->s_fs_info;
struct inode *inode = d_inode(dentry);
struct ubifs_inode *dir_ui = ubifs_inode(dir);
int err, sz_change, budgeted = 1;
struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
unsigned int saved_nlink = inode->i_nlink;
struct fscrypt_name nm;
/*
* Budget request settings: deletion direntry, deletion inode (+1 for
* @dirtied_ino), changing the parent directory inode. If budgeting
* fails, go ahead anyway because we have extra space reserved for
* deletions.
*/
dbg_gen("dent '%pd' from ino %lu (nlink %d) in dir ino %lu",
dentry, inode->i_ino,
inode->i_nlink, dir->i_ino);
err = fscrypt_setup_filename(dir, &dentry->d_name, 1, &nm);
if (err)
return err;
err = ubifs_purge_xattrs(inode);
if (err)
return err;
sz_change = CALC_DENT_SIZE(fname_len(&nm));
ubifs_assert(c, inode_is_locked(dir));
ubifs_assert(c, inode_is_locked(inode));
err = dbg_check_synced_i_size(c, inode);
if (err)
goto out_fname;
err = ubifs_budget_space(c, &req);
if (err) {
if (err != -ENOSPC)
goto out_fname;
budgeted = 0;
}
lock_2_inodes(dir, inode);
inode->i_ctime = current_time(dir);
drop_nlink(inode);
dir->i_size -= sz_change;
dir_ui->ui_size = dir->i_size;
dir->i_mtime = dir->i_ctime = inode->i_ctime;
err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0);
if (err)
goto out_cancel;
unlock_2_inodes(dir, inode);
if (budgeted)
ubifs_release_budget(c, &req);
else {
/* We've deleted something - clean the "no space" flags */
c->bi.nospace = c->bi.nospace_rp = 0;
smp_wmb();
}
fscrypt_free_filename(&nm);
return 0;
out_cancel:
dir->i_size += sz_change;
dir_ui->ui_size = dir->i_size;
set_nlink(inode, saved_nlink);
unlock_2_inodes(dir, inode);
if (budgeted)
ubifs_release_budget(c, &req);
out_fname:
fscrypt_free_filename(&nm);
return err;
}
/**
* check_dir_empty - check if a directory is empty or not.
* @dir: VFS inode object of the directory to check
*
* This function checks if directory @dir is empty. Returns zero if the
* directory is empty, %-ENOTEMPTY if it is not, and other negative error codes
* in case of errors.
*/
int ubifs_check_dir_empty(struct inode *dir)
{
struct ubifs_info *c = dir->i_sb->s_fs_info;
struct fscrypt_name nm = { 0 };
struct ubifs_dent_node *dent;
union ubifs_key key;
int err;
lowest_dent_key(c, &key, dir->i_ino);
dent = ubifs_tnc_next_ent(c, &key, &nm);
if (IS_ERR(dent)) {
err = PTR_ERR(dent);
if (err == -ENOENT)
err = 0;
} else {
kfree(dent);
err = -ENOTEMPTY;
}
return err;
}
static int ubifs_rmdir(struct inode *dir, struct dentry *dentry)
{
struct ubifs_info *c = dir->i_sb->s_fs_info;
struct inode *inode = d_inode(dentry);
int err, sz_change, budgeted = 1;
struct ubifs_inode *dir_ui = ubifs_inode(dir);
struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
struct fscrypt_name nm;
/*
* Budget request settings: deletion direntry, deletion inode and
* changing the parent inode. If budgeting fails, go ahead anyway
* because we have extra space reserved for deletions.
*/
dbg_gen("directory '%pd', ino %lu in dir ino %lu", dentry,
inode->i_ino, dir->i_ino);
ubifs_assert(c, inode_is_locked(dir));
ubifs_assert(c, inode_is_locked(inode));
err = ubifs_check_dir_empty(d_inode(dentry));
if (err)
return err;
err = fscrypt_setup_filename(dir, &dentry->d_name, 1, &nm);
if (err)
return err;
err = ubifs_purge_xattrs(inode);
if (err)
return err;
sz_change = CALC_DENT_SIZE(fname_len(&nm));
err = ubifs_budget_space(c, &req);
if (err) {
if (err != -ENOSPC)
goto out_fname;
budgeted = 0;
}
lock_2_inodes(dir, inode);
inode->i_ctime = current_time(dir);
clear_nlink(inode);
drop_nlink(dir);
dir->i_size -= sz_change;
dir_ui->ui_size = dir->i_size;
dir->i_mtime = dir->i_ctime = inode->i_ctime;
err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0);
if (err)
goto out_cancel;
unlock_2_inodes(dir, inode);
if (budgeted)
ubifs_release_budget(c, &req);
else {
/* We've deleted something - clean the "no space" flags */
c->bi.nospace = c->bi.nospace_rp = 0;
smp_wmb();
}
fscrypt_free_filename(&nm);
return 0;
out_cancel:
dir->i_size += sz_change;
dir_ui->ui_size = dir->i_size;
inc_nlink(dir);
set_nlink(inode, 2);
unlock_2_inodes(dir, inode);
if (budgeted)
ubifs_release_budget(c, &req);
out_fname:
fscrypt_free_filename(&nm);
return err;
}
static int ubifs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
struct dentry *dentry, umode_t mode)
{
struct inode *inode;
struct ubifs_inode *dir_ui = ubifs_inode(dir);
struct ubifs_info *c = dir->i_sb->s_fs_info;
int err, sz_change;
struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1 };
struct fscrypt_name nm;
/*
* Budget request settings: new inode, new direntry and changing parent
* directory inode.
*/
dbg_gen("dent '%pd', mode %#hx in dir ino %lu",
dentry, mode, dir->i_ino);
err = ubifs_budget_space(c, &req);
if (err)
return err;
err = ubifs_prepare_create(dir, dentry, &nm);
if (err)
goto out_budg;
sz_change = CALC_DENT_SIZE(fname_len(&nm));
inode = ubifs_new_inode(c, dir, S_IFDIR | mode);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_fname;
}
err = ubifs_init_security(dir, inode, &dentry->d_name);
if (err)
goto out_inode;
mutex_lock(&dir_ui->ui_mutex);
insert_inode_hash(inode);
inc_nlink(inode);
inc_nlink(dir);
dir->i_size += sz_change;
dir_ui->ui_size = dir->i_size;
dir->i_mtime = dir->i_ctime = inode->i_ctime;
err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0);
if (err) {
ubifs_err(c, "cannot create directory, error %d", err);
goto out_cancel;
}
mutex_unlock(&dir_ui->ui_mutex);
ubifs_release_budget(c, &req);
d_instantiate(dentry, inode);
fscrypt_free_filename(&nm);
return 0;