FAR struct inode *inode_unlink(FAR const char *path)
{
const char *name = path;
FAR struct inode *node;
FAR struct inode *peer;
FAR struct inode *parent;
/* Verify parameters. Ignore null paths and relative paths */
if (!path || *path == '\0' || path[0] != '/')
{
return NULL;
}
/* Find the node to unlink */
node = inode_search(&name, &peer, &parent, (const char **)NULL);
if (node)
{
/* If peer is non-null, then remove the node from the right of
* of that peer node.
*/
if (peer)
{
peer->i_peer = node->i_peer;
}
/* If parent is non-null, then remove the node from head of
* of the list of children.
*/
else if (parent)
{
parent->i_child = node->i_peer;
}
/* Otherwise, we must be removing the root inode. */
else
{
root_inode = node->i_peer;
}
node->i_peer = NULL;
}
return node;
}
int inode_remove(FAR const char *path)
{
const char *name = path;
FAR struct inode *node;
FAR struct inode *left;
FAR struct inode *parent;
if (!*path || path[0] != '/')
{
return -EINVAL;
}
/* Find the node to delete */
node = inode_search(&name, &left, &parent, (const char **)NULL);
if (node)
{
/* Found it, now remove it from the tree */
inode_unlink(node, left, parent);
/* We cannot delete it if there reference to the inode */
if (node->i_crefs)
{
/* In that case, we will mark it deleted, when the FS
* releases the inode, we will then, finally delete
* the subtree.
*/
node->i_flags |= FSNODEFLAG_DELETED;
return -EBUSY;
}
else
{
/* And delete it now -- recursively to delete all of its children */
inode_free(node->i_child);
kfree(node);
return OK;
}
}
/* The node does not exist or it has references */
return -ENOENT;
}
FAR struct inode *inode_find(FAR const char *path, FAR const char **relpath)
{
FAR struct inode *node;
if (!*path || path[0] != '/')
{
return NULL;
}
/* Find the node matching the path. If found,
* increment the count of references on the node.
*/
inode_semtake();
node = inode_search(&path, (FAR struct inode**)NULL, (FAR struct inode**)NULL, relpath);
if (node)
{
node->i_crefs++;
}
inode_semgive();
return node;
}
FAR DIR *opendir(FAR const char *path)
{
FAR struct inode *inode = NULL;
FAR struct fs_dirent_s *dir;
FAR const char *relpath;
bool isroot = false;
int ret;
/* If we are given 'nothing' then we will interpret this as
* request for the root inode.
*/
inode_semtake();
if (!path || *path == 0 || strcmp(path, "/") == 0)
{
inode = root_inode;
isroot = true;
relpath = NULL;
}
else
{
/* We don't know what to do with relative pathes */
if (*path != '/')
{
ret = -ENOTDIR;
goto errout_with_semaphore;
}
/* Find the node matching the path. */
inode = inode_search(&path, (FAR struct inode**)NULL, (FAR struct inode**)NULL, &relpath);
}
/* Did we get an inode? */
if (!inode)
{
/* 'path' is not a does not exist.*/
ret = ENOTDIR;
goto errout_with_semaphore;
}
/* Allocate a type DIR -- which is little more than an inode
* container.
*/
dir = (FAR struct fs_dirent_s *)kuzalloc(sizeof(struct fs_dirent_s));
if (!dir)
{
/* Insufficient memory to complete the operation.*/
ret = ENOMEM;
goto errout_with_semaphore;
}
/* Populate the DIR structure and return it to the caller. The way that
* we do this depends on whenever this is a "normal" pseudo-file-system
* inode or a file system mountpoint.
*/
dir->fd_position = 0; /* This is the position in the read stream */
/* First, handle the special case of the root inode. This must be
* special-cased here because the root inode might ALSO be a mountpoint.
*/
if (isroot)
{
/* Whatever payload the root inode carries, the root inode is always
* a directory inode in the pseudo-file system
*/
open_pseudodir(inode, dir);
}
/* Is this a node in the pseudo filesystem? Or a mountpoint? If the node
* is the root (isroot == TRUE), then this is a special case.
*/
#ifndef CONFIG_DISABLE_MOUNTPOINT
else if (INODE_IS_MOUNTPT(inode))
{
/* Yes, the node is a file system mountpoint */
dir->fd_root = inode; /* Save the inode where we start */
/* Open the directory at the relative path */
ret = open_mountpoint(inode, relpath, dir);
if (ret != OK)
{
goto errout_with_direntry;
}
}
#endif
else
{
/* The node is part of the root pseudo file system. Does the inode
* have a child? If so that the child would be the 'root' of a list
* of nodes under the directory.
*/
FAR struct inode *child = inode->i_child;
if (child)
{
/* It looks we have a valid pseudo-filesystem directory node. */
open_pseudodir(child, dir);
}
else if (!inode->u.i_ops)
{
/* This is a dangling node with no children and no operations. Set
* up to enumerate an empty directory.
*/
open_emptydir(dir);
}
else
{
ret = ENOTDIR;
goto errout_with_direntry;
}
}
inode_semgive();
return ((DIR*)dir);
/* Nasty goto's make error handling simpler */
errout_with_direntry:
kufree(dir);
errout_with_semaphore:
inode_semgive();
set_errno(ret);
return NULL;
}
int inode_reserve(FAR const char *path, FAR struct inode **inode)
{
const char *name = path;
FAR struct inode *left;
FAR struct inode *parent;
/* Assume failure */
DEBUGASSERT(path && inode);
*inode = NULL;
/* Handle paths that are interpreted as the root directory */
if (!*path || path[0] != '/')
{
return -EINVAL;
}
/* Find the location to insert the new subtree */
if (inode_search(&name, &left, &parent, (FAR const char **)NULL) != NULL)
{
/* It is an error if the node already exists in the tree */
return -EEXIST;
}
/* Now we now where to insert the subtree */
for (;;)
{
FAR struct inode *node;
/* Create a new node -- we need to know if this is the
* the leaf node or some intermediary. We can find this
* by looking at the next name.
*/
FAR const char *next_name = inode_nextname(name);
if (*next_name)
{
/* Insert an operationless node */
node = inode_alloc(name);
if (node)
{
inode_insert(node, left, parent);
/* Set up for the next time through the loop */
name = next_name;
left = NULL;
parent = node;
continue;
}
}
else
{
node = inode_alloc(name);
if (node)
{
inode_insert(node, left, parent);
*inode = node;
return OK;
}
}
/* We get here on failures to allocate node memory */
return -ENOMEM;
}
}
