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get rid of kern_path_parent()

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all callers want the same thing, actually - a kinda-sorta analog of
kern_path_create().  I.e. they want parent vfsmount/dentry (with
->i_mutex held, to make sure the child dentry is still their child)
+ the child dentry.

Signed-off-by Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
2012-06-15 03:01:42 +04:00
parent 1acf0af9b9
commit 79714f72d3
4 changed files with 65 additions and 82 deletions
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98
drivers/base/devtmpfs.c
View File

@@ -227,33 +227,24 @@ static int handle_create(const char *nodename, umode_t mode, struct device *dev)
static int dev_rmdir(const char *name)
{
struct nameidata nd;
struct path parent;
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);
dentry = kern_path_locked(name, &parent);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
if (dentry->d_inode) {
if (dentry->d_inode->i_private == &thread)
err = vfs_rmdir(parent.dentry->d_inode, dentry);
else
err = -EPERM;
} else {
err = PTR_ERR(dentry);
err = -ENOENT;
}
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
path_put(&nd.path);
dput(dentry);
mutex_unlock(&parent.dentry->d_inode->i_mutex);
path_put(&parent);
return err;
}
@@ -305,50 +296,43 @@ static int dev_mynode(struct device *dev, struct inode *inode, struct kstat *sta
static int handle_remove(const char *nodename, struct device *dev)
{
struct nameidata nd;
struct path parent;
struct dentry *dentry;
struct kstat stat;
int deleted = 1;
int err;
err = kern_path_parent(nodename, &nd);
if (err)
return err;
dentry = kern_path_locked(nodename, &parent);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
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;
if (dentry->d_inode) {
struct kstat stat;
err = vfs_getattr(parent.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(parent.dentry->d_inode, dentry);
if (!err || err == -ENOENT)
deleted = 1;
}
dput(dentry);
} else {
err = PTR_ERR(dentry);
err = -ENOENT;
}
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
dput(dentry);
mutex_unlock(&parent.dentry->d_inode->i_mutex);
path_put(&nd.path);
path_put(&parent);
if (deleted && strchr(nodename, '/'))
delete_path(nodename);
return err;