/*
* Copyright (c) 2008 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup libfs
* @{
*/
/**
* @file
* Glue code which is commonod to all FS implementations.
*/
#include "libfs.h"
#include "../../srv/vfs/vfs.h"
#include <errno.h>
#include <async.h>
#include <ipc/ipc.h>
#include <as.h>
#include <assert.h>
#include <dirent.h>
/** Register file system server.
*
* This function abstracts away the tedious registration protocol from
* file system implementations and lets them to reuse this registration glue
* code.
*
* @param vfs_phone Open phone for communication with VFS.
* @param reg File system registration structure. It will be
* initialized by this function.
* @param info VFS info structure supplied by the file system
* implementation.
* @param conn Connection fibril for handling all calls originating in
* VFS.
*
* @return EOK on success or a non-zero error code on errror.
*/
int fs_register(int vfs_phone, fs_reg_t *reg, vfs_info_t *info,
async_client_conn_t conn)
{
/*
* Tell VFS that we are here and want to get registered.
* We use the async framework because VFS will answer the request
* out-of-order, when it knows that the operation succeeded or failed.
*/
ipc_call_t answer;
aid_t req = async_send_0(vfs_phone, VFS_REGISTER, &answer);
/*
* Send our VFS info structure to VFS.
*/
int rc = ipc_data_write_start(vfs_phone, info, sizeof(*info));
if (rc != EOK) {
async_wait_for(req, NULL);
return rc;
}
/*
* Ask VFS for callback connection.
*/
ipc_connect_to_me(vfs_phone, 0, 0, 0, ®->vfs_phonehash);
/*
* Allocate piece of address space for PLB.
*/
reg->plb_ro = as_get_mappable_page(PLB_SIZE);
if (!reg->plb_ro) {
async_wait_for(req, NULL);
return ENOMEM;
}
/*
* Request sharing the Path Lookup Buffer with VFS.
*/
rc = ipc_share_in_start_0_0(vfs_phone, reg->plb_ro, PLB_SIZE);
if (rc) {
async_wait_for(req, NULL);
return rc;
}
/*
* Pick up the answer for the request to the VFS_REQUEST call.
*/
async_wait_for(req, NULL);
reg->fs_handle = (int) IPC_GET_ARG1(answer);
/*
* Create a connection fibril to handle the callback connection.
*/
async_new_connection(reg->vfs_phonehash, 0, NULL, conn);
/*
* Tell the async framework that other connections are to be handled by
* the same connection fibril as well.
*/
async_set_client_connection(conn);
return IPC_GET_RETVAL(answer);
}
/** Lookup VFS triplet by name in the file system name space.
*
* The path passed in the PLB must be in the canonical file system path format
* as returned by the canonify() function.
*
* @param ops libfs operations structure with function pointers to
* file system implementation
* @param fs_handle File system handle of the file system where to perform
* the lookup.
* @param rid Request ID of the VFS_LOOKUP request.
* @param request VFS_LOOKUP request data itself.
*/
void libfs_lookup(libfs_ops_t *ops, fs_handle_t fs_handle, ipc_callid_t rid,
ipc_call_t *request)
{
unsigned next = IPC_GET_ARG1(*request);
unsigned last = IPC_GET_ARG2(*request);
dev_handle_t dev_handle = IPC_GET_ARG3(*request);
int lflag = IPC_GET_ARG4(*request);
fs_index_t index = IPC_GET_ARG5(*request); /* when L_LINK specified */
char component[NAME_MAX + 1];
int len;
if (last < next)
last += PLB_SIZE;
void *par = NULL;
void *cur = ops->root_get(dev_handle);
void *tmp = NULL;
if (ops->plb_get_char(next) == '/')
next++; /* eat slash */
while (next <= last && ops->has_children(cur)) {
/* collect the component */
len = 0;
while ((next <= last) && (ops->plb_get_char(next) != '/')) {
if (len + 1 == NAME_MAX) {
/* component length overflow */
ipc_answer_0(rid, ENAMETOOLONG);
goto out;
}
component[len++] = ops->plb_get_char(next);
next++; /* process next character */
}
component[len] = '\0';
next++; /* eat slash */
/* match the component */
tmp = ops->match(cur, component);
/* handle miss: match amongst siblings */
if (!tmp) {
if (next <= last) {
/* there are unprocessed components */
ipc_answer_0(rid, ENOENT);
goto out;
}
/* miss in the last component */
if (lflag & (L_CREATE | L_LINK)) {
/* request to create a new link */
if (!ops->is_directory(cur)) {
ipc_answer_0(rid, ENOTDIR);
goto out;
}
void *nodep;
if (lflag & L_CREATE)
nodep = ops->create(dev_handle, lflag);
else
nodep = ops->node_get(dev_handle,
index);
if (nodep) {
if (!ops->link(cur, nodep, component)) {
if (lflag & L_CREATE) {
(void)ops->destroy(
nodep);
}
ipc_answer_0(rid, ENOSPC);
} else {
ipc_answer_5(rid, EOK,
fs_handle, dev_handle,
ops->index_get(nodep),
ops->size_get(nodep),
ops->lnkcnt_get(nodep));
ops->node_put(nodep);
}
} else {
ipc_answer_0(rid, ENOSPC);
}
goto out;
} else if (lflag & L_PARENT) {
/* return parent */
ipc_answer_5(rid, EOK, fs_handle, dev_handle,
ops->index_get(cur), ops->size_get(cur),
ops->lnkcnt_get(cur));
}
ipc_answer_0(rid, ENOENT);
goto out;
}
if (par)
ops->node_put(par);
/* descend one level */
par = cur;
cur = tmp;
tmp = NULL;
}
/* handle miss: excessive components */
if (next <= last && !ops->has_children(cur)) {
if (lflag & (L_CREATE | L_LINK)) {
if (!ops->is_directory(cur)) {
ipc_answer_0(rid, ENOTDIR);
goto out;
}
/* collect next component */
len = 0;
while (next <= last) {
if (ops->plb_get_char(next) == '/') {
/* more than one component */
ipc_answer_0(rid, ENOENT);
goto out;
}
if (len + 1 == NAME_MAX) {
/* component length overflow */
ipc_answer_0(rid, ENAMETOOLONG);
goto out;
}
component[len++] = ops->plb_get_char(next);
next++; /* process next character */
}
component[len] = '\0';
void *nodep;
if (lflag & L_CREATE)
nodep = ops->create(dev_handle, lflag);
else
nodep = ops->node_get(dev_handle, index);
if (nodep) {
if (!ops->link(cur, nodep, component)) {
if (lflag & L_CREATE)
(void)ops->destroy(nodep);
ipc_answer_0(rid, ENOSPC);
} else {
ipc_answer_5(rid, EOK,
fs_handle, dev_handle,
ops->index_get(nodep),
ops->size_get(nodep),
ops->lnkcnt_get(nodep));
ops->node_put(nodep);
}
} else {
ipc_answer_0(rid, ENOSPC);
}
goto out;
}
ipc_answer_0(rid, ENOENT);
goto out;
}
/* handle hit */
if (lflag & L_PARENT) {
ops->node_put(cur);
cur = par;
par = NULL;
if (!cur) {
ipc_answer_0(rid, ENOENT);
goto out;
}
}
if (lflag & L_UNLINK) {
unsigned old_lnkcnt = ops->lnkcnt_get(cur);
int res = ops->unlink(par, cur);
ipc_answer_5(rid, (ipcarg_t)res, fs_handle, dev_handle,
ops->index_get(cur), ops->size_get(cur), old_lnkcnt);
goto out;
}
if (((lflag & (L_CREATE | L_EXCLUSIVE)) == (L_CREATE | L_EXCLUSIVE)) ||
(lflag & L_LINK)) {
ipc_answer_0(rid, EEXIST);
goto out;
}
if ((lflag & L_FILE) && (ops->is_directory(cur))) {
ipc_answer_0(rid, EISDIR);
goto out;
}
if ((lflag & L_DIRECTORY) && (ops->is_file(cur))) {
ipc_answer_0(rid, ENOTDIR);
goto out;
}
ipc_answer_5(rid, EOK, fs_handle, dev_handle, ops->index_get(cur),
ops->size_get(cur), ops->lnkcnt_get(cur));
out:
if (par)
ops->node_put(par);
if (cur)
ops->node_put(cur);
if (tmp)
ops->node_put(tmp);
}
/** @}
*/