/**
* relayfs_create_entry - create a relayfs directory or file
* @name: the name of the file to create
* @parent: parent directory
* @mode: mode
* @chan: relay channel associated with the file
*
* Returns the new dentry, NULL on failure
*
* Creates a file or directory with the specifed permissions.
*/
static struct dentry *relayfs_create_entry(const char *name,
struct dentry *parent,
int mode,
struct rchan *chan)
{
struct dentry *d;
struct inode *inode;
int error = 0;
BUG_ON(!name || !(S_ISREG(mode) || S_ISDIR(mode)));
error = simple_pin_fs("relayfs", &relayfs_mount, &relayfs_mount_count);
if (error) {
printk(KERN_ERR "Couldn't mount relayfs: errcode %d\n", error);
return NULL;
}
if (!parent && relayfs_mount && relayfs_mount->mnt_sb)
parent = relayfs_mount->mnt_sb->s_root;
if (!parent) {
simple_release_fs(&relayfs_mount, &relayfs_mount_count);
return NULL;
}
parent = dget(parent);
down(&parent->d_inode->i_sem);
d = lookup_one_len(name, parent, strlen(name));
if (IS_ERR(d)) {
d = NULL;
goto release_mount;
}
if (d->d_inode) {
d = NULL;
goto release_mount;
}
inode = relayfs_get_inode(parent->d_inode->i_sb, mode, chan);
if (!inode) {
d = NULL;
goto release_mount;
}
d_instantiate(d, inode);
dget(d); /* Extra count - pin the dentry in core */
if (S_ISDIR(mode))
parent->d_inode->i_nlink++;
goto exit;
release_mount:
simple_release_fs(&relayfs_mount, &relayfs_mount_count);
exit:
up(&parent->d_inode->i_sem);
dput(parent);
return d;
}
/**
* sysfs_chmod_file - update the modified mode value on an object attribute.
* @kobj: object we're acting for.
* @attr: attribute descriptor.
* @mode: file permissions.
*
*/
int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode)
{
struct dentry *dir = kobj->dentry;
struct dentry *victim;
struct inode * inode;
struct iattr newattrs;
int res = -ENOENT;
mutex_lock(&dir->d_inode->i_mutex);
victim = lookup_one_len(attr->name, dir, strlen(attr->name));
if (!IS_ERR(victim)) {
if (victim->d_inode &&
(victim->d_parent->d_inode == dir->d_inode)) {
inode = victim->d_inode;
mutex_lock(&inode->i_mutex);
newattrs.ia_mode = (mode & S_IALLUGO) |
(inode->i_mode & ~S_IALLUGO);
newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
res = notify_change(victim, &newattrs);
mutex_unlock(&inode->i_mutex);
}
dput(victim);
}
mutex_unlock(&dir->d_inode->i_mutex);
return res;
}
static struct dentry *get_node(int num)
{
char s[10];
struct dentry *root = capifs_root;
mutex_lock(&root->d_inode->i_mutex);
return lookup_one_len(s, root, sprintf(s, "%d", num));
}
static int create_by_name(const char *name, mode_t mode,
struct dentry *parent,
struct dentry **dentry)
{
int error = 0;
*dentry = NULL;
/* If the parent is not specified, we create it in the root.
* We need the root dentry to do this, which is in the super
* block. A pointer to that is in the struct vfsmount that we
* have around.
*/
if (!parent)
parent = mount->mnt_sb->s_root;
mutex_lock(&parent->d_inode->i_mutex);
*dentry = lookup_one_len(name, parent, strlen(name));
if (!IS_ERR(*dentry)) {
if ((mode & S_IFMT) == S_IFDIR)
error = mkdir(parent->d_inode, *dentry, mode);
else
error = create(parent->d_inode, *dentry, mode);
if (error)
dput(*dentry);
} else
error = PTR_ERR(*dentry);
mutex_unlock(&parent->d_inode->i_mutex);
return error;
}
static struct dentry *lookup_whiteout(struct dentry *dentry)
{
char *whname;
int bindex = -1, bstart = -1, bend = -1;
struct dentry *parent, *hidden_parent, *wh_dentry;
whname = alloc_whname(dentry->d_name.name, dentry->d_name.len);
if (IS_ERR(whname))
return (void *)whname;
parent = dget_parent(dentry);
unionfs_lock_dentry(parent);
bstart = dbstart(parent);
bend = dbend(parent);
wh_dentry = ERR_PTR(-ENOENT);
for (bindex = bstart; bindex <= bend; bindex++) {
hidden_parent = unionfs_lower_dentry_idx(parent, bindex);
if (!hidden_parent)
continue;
wh_dentry = lookup_one_len(whname, hidden_parent,
dentry->d_name.len + UNIONFS_WHLEN);
if (IS_ERR(wh_dentry))
continue;
if (wh_dentry->d_inode)
break;
dput(wh_dentry);
wh_dentry = ERR_PTR(-ENOENT);
}
unionfs_unlock_dentry(parent);
dput(parent);
kfree(whname);
return wh_dentry;
}
/*
* Lookup one path component @name relative to a <base,mnt> path pair.
* Behaves nearly the same as lookup_one_len (i.e., return negative dentry
* on ENOENT), but uses the @mnt passed, so it can cross bind mounts and
* other lower mounts properly. If @new_mnt is non-null, will fill in the
* new mnt there. Caller is responsible to dput/mntput/path_put returned
* @dentry and @new_mnt.
*/
struct dentry *__lookup_one(struct dentry *base, struct vfsmount *mnt,
const char *name, struct vfsmount **new_mnt)
{
struct dentry *dentry = NULL;
struct nameidata lower_nd;
int err;
/* we use flags=0 to get basic lookup */
err = vfs_path_lookup(base, mnt, name, 0, &lower_nd);
switch (err) {
case 0: /* no error */
dentry = lower_nd.path.dentry;
if (new_mnt)
*new_mnt = lower_nd.path.mnt; /* rc already inc'ed */
break;
case -ENOENT:
/*
* We don't consider ENOENT an error, and we want to return
* a negative dentry (ala lookup_one_len). As we know
* there was no inode for this name before (-ENOENT), then
* it's safe to call lookup_one_len (which doesn't take a
* vfsmount).
*/
dentry = lookup_one_len(name, base, strlen(name));
if (new_mnt)
*new_mnt = mntget(lower_nd.path.mnt);
break;
default: /* all other real errors */
dentry = ERR_PTR(err);
break;
}
return dentry;
}
static int ovl_create_upper(struct dentry *dentry, struct inode *inode,
struct kstat *stat, const char *link,
struct dentry *hardlink)
{
struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);
struct inode *udir = upperdir->d_inode;
struct dentry *newdentry;
int err;
mutex_lock_nested(&udir->i_mutex, I_MUTEX_PARENT);
newdentry = lookup_one_len(dentry->d_name.name, upperdir,
dentry->d_name.len);
err = PTR_ERR(newdentry);
if (IS_ERR(newdentry))
goto out_unlock;
err = ovl_create_real(udir, newdentry, stat, link, hardlink, false);
if (err)
goto out_dput;
ovl_dentry_version_inc(dentry->d_parent);
ovl_dentry_update(dentry, newdentry);
ovl_copyattr(newdentry->d_inode, inode);
d_instantiate(dentry, inode);
newdentry = NULL;
out_dput:
dput(newdentry);
out_unlock:
mutex_unlock(&udir->i_mutex);
return err;
}
/**
* Prepares a directory operation by taking the mutex on the parent inode of
* an entry and returning a dentry for the entry.
*
* @param child_name path to the entry, assumed absolute from configfs
* scheduler subsystem entry.
*
* @return a valid dentry to the target entry, or error. The valid
* dentry must be released with put_child_dentry.
*/
static struct dentry *get_child_dentry(const char *child_name)
{
struct dentry *d_dir;
struct dentry *d_child;
const char *last_child_comp;
const char *real_child_name = child_name;
int err;
d_dir = dget(krg_scheduler_subsys.su_group.cg_item.ci_dentry);
last_child_comp = strrchr(child_name, '/');
if (last_child_comp) {
struct nameidata nd;
err = vfs_path_lookup(d_dir, scheduler_fs_mount,
child_name, LOOKUP_PARENT, &nd);
dput(d_dir);
if (err)
return ERR_PTR(err);
d_dir = dget(nd.path.dentry);
path_put(&nd.path);
BUG_ON(!last_child_comp[1]);
real_child_name = last_child_comp + 1;
}
mutex_lock_nested(&d_dir->d_inode->i_mutex, I_MUTEX_PARENT);
d_child = lookup_one_len(real_child_name, d_dir, strlen(real_child_name));
if (IS_ERR(d_child))
mutex_unlock(&d_dir->d_inode->i_mutex);
dput(d_dir);
return d_child;
}
static int lookup_and_delete_xattr(struct inode *inode, const char *name)
{
int err = 0;
struct dentry *dentry, *xadir;
xadir = open_xa_dir(inode, XATTR_REPLACE);
if (IS_ERR(xadir))
return PTR_ERR(xadir);
mutex_lock_nested(&xadir->d_inode->i_mutex, I_MUTEX_XATTR);
dentry = lookup_one_len(name, xadir, strlen(name));
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
goto out_dput;
}
if (dentry->d_inode) {
reiserfs_write_lock(inode->i_sb);
err = xattr_unlink(xadir->d_inode, dentry);
reiserfs_write_unlock(inode->i_sb);
update_ctime(inode);
}
dput(dentry);
out_dput:
mutex_unlock(&xadir->d_inode->i_mutex);
dput(xadir);
return err;
}
static int ovl_create_upper(struct dentry *dentry, struct inode *inode,
struct cattr *attr, struct dentry *hardlink)
{
struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);
struct inode *udir = upperdir->d_inode;
struct dentry *newdentry;
int err;
if (!hardlink && !IS_POSIXACL(udir))
attr->mode &= ~current_umask();
inode_lock_nested(udir, I_MUTEX_PARENT);
newdentry = lookup_one_len(dentry->d_name.name, upperdir,
dentry->d_name.len);
err = PTR_ERR(newdentry);
if (IS_ERR(newdentry))
goto out_unlock;
err = ovl_create_real(udir, newdentry, attr, hardlink, false);
if (err)
goto out_dput;
if (ovl_type_merge(dentry->d_parent)) {
/* Setting opaque here is just an optimization, allow to fail */
ovl_set_opaque(dentry, newdentry);
}
ovl_instantiate(dentry, inode, newdentry, !!hardlink);
newdentry = NULL;
out_dput:
dput(newdentry);
out_unlock:
inode_unlock(udir);
return err;
}
static struct dentry *get_node(int num)
{
char s[12];
struct dentry *root = devpts_root;
down(&root->d_inode->i_sem);
return lookup_one_len(s, root, sprintf(s, "%d", num));
}
static int remove_file(struct dentry *parent, char *name)
{
struct dentry *tmp;
int ret;
tmp = lookup_one_len(name, parent, strlen(name));
if (IS_ERR(tmp)) {
ret = PTR_ERR(tmp);
goto bail;
}
spin_lock(&dcache_lock);
spin_lock(&tmp->d_lock);
if (!(d_unhashed(tmp) && tmp->d_inode)) {
dget_locked(tmp);
__d_drop(tmp);
spin_unlock(&tmp->d_lock);
spin_unlock(&dcache_lock);
simple_unlink(parent->d_inode, tmp);
} else {
spin_unlock(&tmp->d_lock);
spin_unlock(&dcache_lock);
}
ret = 0;
bail:
/*
* We don't expect clients to care about the return value, but
* it's there if they need it.
*/
return ret;
}
static int ovl_mkdir_real(struct inode *dir, struct dentry **newdentry,
umode_t mode)
{
int err;
struct dentry *d, *dentry = *newdentry;
err = ovl_do_mkdir(dir, dentry, mode);
if (err)
return err;
if (likely(!d_unhashed(dentry)))
return 0;
/*
* vfs_mkdir() may succeed and leave the dentry passed
* to it unhashed and negative. If that happens, try to
* lookup a new hashed and positive dentry.
*/
d = lookup_one_len(dentry->d_name.name, dentry->d_parent,
dentry->d_name.len);
if (IS_ERR(d)) {
pr_warn("overlayfs: failed lookup after mkdir (%pd2, err=%i).\n",
dentry, err);
return PTR_ERR(d);
}
dput(dentry);
*newdentry = d;
return 0;
}
static int ovl_create_upper(struct dentry *dentry, struct inode *inode,
struct kstat *stat, const char *link,
struct dentry *hardlink)
{
struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);
struct inode *udir = upperdir->d_inode;
struct dentry *newdentry;
int err;
if (!hardlink && !IS_POSIXACL(udir))
stat->mode &= ~current_umask();
inode_lock_nested(udir, I_MUTEX_PARENT);
newdentry = lookup_one_len(dentry->d_name.name, upperdir,
dentry->d_name.len);
err = PTR_ERR(newdentry);
if (IS_ERR(newdentry))
goto out_unlock;
err = ovl_create_real(udir, newdentry, stat, link, hardlink, false);
if (err)
goto out_dput;
ovl_instantiate(dentry, inode, newdentry, !!hardlink);
newdentry = NULL;
out_dput:
dput(newdentry);
out_unlock:
inode_unlock(udir);
return err;
}
static int dev_rmdir(const char *name)
{
struct nameidata nd;
struct dentry *dentry;
int err;
err = kern_path_parent(name, &nd);
if (err)
return err;
mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
dentry = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len);
if (!IS_ERR(dentry)) {
if (dentry->d_inode) {
if (dentry->d_inode->i_private == &thread)
err = vfs_rmdir(nd.path.dentry->d_inode,
dentry);
else
err = -EPERM;
} else {
err = -ENOENT;
}
dput(dentry);
} else {
err = PTR_ERR(dentry);
}
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
path_put(&nd.path);
return err;
}
static int
fill_with_dentries(void *buf, const char *name, int namelen, loff_t offset,
u64 ino, unsigned int d_type)
{
struct reiserfs_dentry_buf *dbuf = buf;
struct dentry *dentry;
WARN_ON_ONCE(!mutex_is_locked(&dbuf->xadir->d_inode->i_mutex));
if (dbuf->count == ARRAY_SIZE(dbuf->dentries))
return -ENOSPC;
if (name[0] == '.' && (namelen < 2 ||
(namelen == 2 && name[1] == '.')))
return 0;
dentry = lookup_one_len(name, dbuf->xadir, namelen);
if (IS_ERR(dentry)) {
return PTR_ERR(dentry);
} else if (!dentry->d_inode) {
/* A directory entry exists, but no file? */
reiserfs_error(dentry->d_sb, "xattr-20003",
"Corrupted directory: xattr %s listed but "
"not found for file %s.\n",
dentry->d_name.name, dbuf->xadir->d_name.name);
dput(dentry);
return -EIO;
}
dbuf->dentries[dbuf->count++] = dentry;
return 0;
}
static struct dentry *ovl_workdir_create(struct vfsmount *mnt,
struct dentry *dentry)
{
struct inode *dir = dentry->d_inode;
struct dentry *work;
int err;
bool retried = false;
err = mnt_want_write(mnt);
if (err)
return ERR_PTR(err);
mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
retry:
work = lookup_one_len(OVL_WORKDIR_NAME, dentry,
strlen(OVL_WORKDIR_NAME));
if (!IS_ERR(work)) {
struct kstat stat = {
.mode = S_IFDIR | 0,
};
if (work->d_inode) {
err = -EEXIST;
if (retried)
goto out_dput;
retried = true;
ovl_cleanup(dir, work);
dput(work);
goto retry;
}
err = ovl_create_real(dir, work, &stat, NULL, NULL, true);
if (err)
goto out_dput;
}
out_unlock:
mutex_unlock(&dir->i_mutex);
mnt_drop_write(mnt);
return work;
out_dput:
dput(work);
work = ERR_PTR(err);
goto out_unlock;
}
static int ovl_mount_dir(const char *name, struct path *path)
{
int err;
err = kern_path(name, LOOKUP_FOLLOW, path);
if (err) {
pr_err("overlayfs: failed to resolve '%s': %i\n", name, err);
err = -EINVAL;
}
return err;
}
static int remove_device_files(struct super_block *sb,
struct ipath_devdata *dd)
{
struct dentry *dir, *root;
char unit[10];
int ret;
root = dget(sb->s_root);
mutex_lock(&root->d_inode->i_mutex);
snprintf(unit, sizeof unit, "%02d", dd->ipath_unit);
dir = lookup_one_len(unit, root, strlen(unit));
if (IS_ERR(dir)) {
ret = PTR_ERR(dir);
printk(KERN_ERR "Lookup of %s failed\n", unit);
goto bail;
}
remove_file(dir, "flash");
remove_file(dir, "atomic_counters");
d_delete(dir);
ret = simple_rmdir(root->d_inode, dir);
bail:
mutex_unlock(&root->d_inode->i_mutex);
dput(root);
return ret;
}
static struct dentry *open_xa_dir(const struct inode *inode, int flags)
{
struct dentry *xaroot, *xadir;
char namebuf[17];
xaroot = open_xa_root(inode->i_sb, flags);
if (IS_ERR(xaroot))
return xaroot;
snprintf(namebuf, sizeof(namebuf), "%X.%X",
le32_to_cpu(INODE_PKEY(inode)->k_objectid),
inode->i_generation);
mutex_lock_nested(&xaroot->d_inode->i_mutex, I_MUTEX_XATTR);
xadir = lookup_one_len(namebuf, xaroot, strlen(namebuf));
if (!IS_ERR(xadir) && !xadir->d_inode) {
int err = -ENODATA;
if (xattr_may_create(flags))
err = xattr_mkdir(xaroot->d_inode, xadir, 0700);
if (err) {
dput(xadir);
xadir = ERR_PTR(err);
}
}
mutex_unlock(&xaroot->d_inode->i_mutex);
dput(xaroot);
return xadir;
}
static int dev_rmdir(const char *name)
{
struct nameidata nd;
struct dentry *dentry;
int err;
struct vfsmount *dev_mnt = ve_devmnt();
err = vfs_path_lookup(dev_mnt->mnt_root, dev_mnt,
name, LOOKUP_PARENT, &nd);
if (err)
return err;
mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
dentry = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len);
if (!IS_ERR(dentry)) {
if (dentry->d_inode)
err = vfs_rmdir(nd.path.dentry->d_inode, dentry);
else
err = -ENOENT;
dput(dentry);
} else {
err = PTR_ERR(dentry);
}
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
path_put(&nd.path);
return err;
}
/**
* sysfs_update_file - update the modified timestamp on an object attribute.
* @kobj: object we're acting for.
* @attr: attribute descriptor.
*/
int sysfs_update_file(struct kobject * kobj, const struct attribute * attr)
{
struct dentry * dir = kobj->dentry;
struct dentry * victim;
int res = -ENOENT;
mutex_lock(&dir->d_inode->i_mutex);
victim = lookup_one_len(attr->name, dir, strlen(attr->name));
if (!IS_ERR(victim)) {
/* make sure dentry is really there */
if (victim->d_inode &&
(victim->d_parent->d_inode == dir->d_inode)) {
victim->d_inode->i_mtime = CURRENT_TIME;
fsnotify_modify(victim);
res = 0;
} else
d_drop(victim);
/**
* Drop the reference acquired from lookup_one_len() above.
*/
dput(victim);
}
mutex_unlock(&dir->d_inode->i_mutex);
return res;
}
static int ovl_whiteout(struct dentry *upperdir, struct dentry *dentry)
{
int err;
struct dentry *newdentry;
const struct cred *old_cred;
struct cred *override_cred;
/* FIXME: recheck lower dentry to see if whiteout is really needed */
err = -ENOMEM;
override_cred = ovl_prepare_creds(dentry->d_sb);
if (!override_cred)
goto out;
override_cred->fsuid = make_kuid(override_cred->user_ns, 0);
if (!uid_valid(override_cred->fsuid))
override_cred->fsuid = GLOBAL_ROOT_UID;
override_cred->fsgid = make_kgid(override_cred->user_ns, 0);
if (!gid_valid(override_cred->fsgid))
override_cred->fsgid = GLOBAL_ROOT_GID;
old_cred = override_creds(override_cred);
newdentry = lookup_one_len(dentry->d_name.name, upperdir,
dentry->d_name.len);
err = PTR_ERR(newdentry);
if (IS_ERR(newdentry))
goto out_put_cred;
/* Just been removed within the same locked region */
WARN_ON(newdentry->d_inode);
err = vfs_symlink(upperdir->d_inode, newdentry, ovl_whiteout_symlink);
if (err)
goto out_dput;
ovl_dentry_version_inc(dentry->d_parent);
err = ovl_do_setxattr(newdentry, ovl_whiteout_xattr, "y", 1, 0);
if (err)
vfs_unlink(upperdir->d_inode, newdentry, NULL);
out_dput:
dput(newdentry);
out_put_cred:
revert_creds(old_cred);
put_cred(override_cred);
out:
if (err) {
/*
* There's no way to recover from failure to whiteout.
* What should we do? Log a big fat error and... ?
*/
pr_err("overlayfs: ERROR - failed to whiteout '%s'\n",
dentry->d_name.name);
}
return err;
}
/*
* Get root dentry from superblock according to prefix path mount option.
* Return dentry with refcount + 1 on success and NULL otherwise.
*/
static struct dentry *
cifs_get_root(struct smb_vol *vol, struct super_block *sb)
{
struct dentry *dentry;
struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
char *full_path = NULL;
char *s, *p;
char sep;
int xid;
full_path = cifs_build_path_to_root(vol, cifs_sb,
cifs_sb_master_tcon(cifs_sb));
if (full_path == NULL)
return ERR_PTR(-ENOMEM);
cFYI(1, "Get root dentry for %s", full_path);
xid = GetXid();
sep = CIFS_DIR_SEP(cifs_sb);
dentry = dget(sb->s_root);
p = s = full_path;
do {
struct inode *dir = dentry->d_inode;
struct dentry *child;
if (!dir) {
dput(dentry);
dentry = ERR_PTR(-ENOENT);
break;
}
if (!S_ISDIR(dir->i_mode)) {
dput(dentry);
dentry = ERR_PTR(-ENOTDIR);
break;
}
/* skip separators */
while (*s == sep)
s++;
if (!*s)
break;
p = s++;
/* next separator */
while (*s && *s != sep)
s++;
mutex_lock(&dir->i_mutex);
child = lookup_one_len(p, dentry, s - p);
mutex_unlock(&dir->i_mutex);
dput(dentry);
dentry = child;
} while (!IS_ERR(dentry));
_FreeXid(xid);
kfree(full_path);
return dentry;
}
static void __init aafs_remove(const char *name)
{
struct dentry *dentry;
dentry = lookup_one_len(name, aa_fs_dentry, strlen(name));
if (!IS_ERR(dentry)) {
securityfs_remove(dentry);
dput(dentry);
}
}
int do_lookup2 (struct inode *inode, const char *name, int len,
struct dentry **result, int lock_f)
{
struct dentry *tmp_dent;
struct dentry *r_dent;
int ret_code;
if ( lock_f )
DOWN(&(inode->i_sem));
/* Grab a dentry for the directory. */
tmp_dent = ovlfs_inode2dentry(inode);
if ( tmp_dent == NULL )
{
WARN("failed to obtain dentry for dir inode %lu",
inode->i_ino);
return -ENOENT;
}
/* Perform the lookup; this will call the filesystem's */
/* lookup entry-point, if needed. */
r_dent = lookup_one_len(name, tmp_dent, len);
if ( IS_ERR(r_dent) )
{
ret_code = PTR_ERR(r_dent);
}
else if ( r_dent == NULL )
{
ret_code = -ENOENT;
}
else if ( r_dent->d_inode == NULL )
{
dput(r_dent);
ret_code = -ENOENT;
}
else
{
ret_code = 0;
result[0] = r_dent;
}
dput(tmp_dent);
if ( lock_f )
UP(&(inode->i_sem));
return ret_code;
}
struct dentry *__create_file(const char *name, umode_t mode,
struct dentry *parent, void *data,
const struct file_operations *fops)
{
struct dentry *dentry = NULL;
int error;
pr_debug("debugfs: creating file '%s'\n",name);
error = simple_pin_fs(&debug_fs_type, &debugfs_mount,
&debugfs_mount_count);
if (error)
goto exit;
/* If the parent is not specified, we create it in the root.
* We need the root dentry to do this, which is in the super
* block. A pointer to that is in the struct vfsmount that we
* have around.
*/
if (!parent)
parent = debugfs_mount->mnt_root;
dentry = NULL;
mutex_lock(&parent->d_inode->i_mutex);
dentry = lookup_one_len(name, parent, strlen(name));
if (!IS_ERR(dentry)) {
switch (mode & S_IFMT) {
case S_IFDIR:
error = debugfs_mkdir(parent->d_inode, dentry, mode);
break;
case S_IFLNK:
error = debugfs_link(parent->d_inode, dentry, mode,
data);
break;
default:
error = debugfs_create(parent->d_inode, dentry, mode,
data, fops);
break;
}
dput(dentry);
} else
error = PTR_ERR(dentry);
mutex_unlock(&parent->d_inode->i_mutex);
if (error) {
dentry = NULL;
simple_release_fs(&debugfs_mount, &debugfs_mount_count);
}
exit:
return dentry;
}
int devtmpfs_delete_node(struct device *dev)
{
const char *tmp = NULL;
const char *nodename;
const struct cred *curr_cred;
struct nameidata nd;
struct dentry *dentry;
struct kstat stat;
int deleted = 1;
int err;
if (!dev_mnt)
return 0;
nodename = device_get_devnode(dev, NULL, &tmp);
if (!nodename)
return -ENOMEM;
curr_cred = override_creds(&init_cred);
err = vfs_path_lookup(dev_mnt->mnt_root, dev_mnt,
nodename, LOOKUP_PARENT, &nd);
if (err)
goto out;
mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
dentry = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len);
if (!IS_ERR(dentry)) {
if (dentry->d_inode) {
err = vfs_getattr(nd.path.mnt, dentry, &stat);
if (!err && dev_mynode(dev, dentry->d_inode, &stat)) {
err = vfs_unlink(nd.path.dentry->d_inode,
dentry);
if (!err || err == -ENOENT)
deleted = 1;
}
} else {
err = -ENOENT;
}
dput(dentry);
} else {
err = PTR_ERR(dentry);
}
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
path_put(&nd.path);
if (deleted && strchr(nodename, '/'))
delete_path(nodename);
out:
kfree(tmp);
revert_creds(curr_cred);
return err;
}
struct dentry *vfsub_lookup_one_len(const char *name, struct dentry *parent,
int len)
{
struct dentry *d;
LKTRTrace("%.*s/%.*s\n", AuDLNPair(parent), len, name);
IMustLock(parent->d_inode);
d = lookup_one_len(name, parent, len);
if (!IS_ERR(d))
au_update_fuse_h_inode(NULL, d); /*ignore*/
return d;
}
/*
* Create a new subvolume below @parent. This is largely modeled after
* sys_mkdirat and vfs_mkdir, but we only do a single component lookup
* inside this filesystem so it's quite a bit simpler.
*/
static noinline int btrfs_mksubvol(struct path *parent,
char *name, int namelen,
struct btrfs_root *snap_src)
{
struct inode *dir = parent->dentry->d_inode;
struct dentry *dentry;
int error;
mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
dentry = lookup_one_len(name, parent->dentry, namelen);
error = PTR_ERR(dentry);
if (IS_ERR(dentry))
goto out_unlock;
error = -EEXIST;
if (dentry->d_inode)
goto out_dput;
error = mnt_want_write(parent->mnt);
if (error)
goto out_dput;
error = btrfs_may_create(dir, dentry);
if (error)
goto out_drop_write;
down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
goto out_up_read;
if (snap_src) {
error = create_snapshot(snap_src, dentry,
name, namelen);
} else {
error = create_subvol(BTRFS_I(dir)->root, dentry,
name, namelen);
}
if (!error)
fsnotify_mkdir(dir, dentry);
out_up_read:
up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
out_drop_write:
mnt_drop_write(parent->mnt);
out_dput:
dput(dentry);
out_unlock:
mutex_unlock(&dir->i_mutex);
return error;
}
static int handle_remove(const char *nodename, struct device *dev)
{
struct nameidata nd;
struct dentry *dentry;
struct kstat stat;
int deleted = 1;
int err;
err = kern_path_parent(nodename, &nd);
if (err)
return err;
mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
dentry = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len);
if (!IS_ERR(dentry)) {
if (dentry->d_inode) {
err = vfs_getattr(nd.path.mnt, dentry, &stat);
if (!err && dev_mynode(dev, dentry->d_inode, &stat)) {
struct iattr newattrs;
/*
* before unlinking this node, reset permissions
* of possible references like hardlinks
*/
newattrs.ia_uid = 0;
newattrs.ia_gid = 0;
newattrs.ia_mode = stat.mode & ~0777;
newattrs.ia_valid =
ATTR_UID|ATTR_GID|ATTR_MODE;
mutex_lock(&dentry->d_inode->i_mutex);
notify_change(dentry, &newattrs);
mutex_unlock(&dentry->d_inode->i_mutex);
err = vfs_unlink(nd.path.dentry->d_inode,
dentry);
if (!err || err == -ENOENT)
deleted = 1;
}
} else {
err = -ENOENT;
}
dput(dentry);
} else {
err = PTR_ERR(dentry);
}
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
path_put(&nd.path);
if (deleted && strchr(nodename, '/'))
delete_path(nodename);
return err;
}
