WebSVN – HelenOS – Diff – /branches/dynload/uspace/srv/vfs/vfs_ops.c


/*
 * 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 fs
 * @{
 */
 
/**
 * @file vfs_ops.c
 * @brief Operations that VFS offers to its clients.
 */
 
#include "vfs.h"
#include <ipc/ipc.h>
#include <async.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <bool.h>
#include <futex.h>
#include <rwlock.h>
#include <libadt/list.h>
#include <unistd.h>
#include <ctype.h>
#include <fcntl.h>
#include <assert.h>
#include <vfs/canonify.h>
 
/* Forward declarations of static functions. */
static int vfs_truncate_internal(fs_handle_t, dev_handle_t, fs_index_t, size_t);
 
/** Pending mount structure. */
typedef struct {
    link_t link;
    char *fs_name;            /**< File system name */
    char *mp;                 /**< Mount point */
    char *opts;       /**< Mount options. */
    ipc_callid_t callid;      /**< Call ID waiting for the mount */
    ipc_callid_t rid;         /**< Request ID */
    dev_handle_t dev_handle;  /**< Device handle */
} pending_req_t;
 
LIST_INITIALIZE(pending_req);
 
/**
 * This rwlock prevents the race between a triplet-to-VFS-node resolution and a
 * concurrent VFS operation which modifies the file system namespace.
 */
RWLOCK_INITIALIZE(namespace_rwlock);
 
futex_t rootfs_futex = FUTEX_INITIALIZER;
vfs_pair_t rootfs = {
    .fs_handle = 0,
    .dev_handle = 0
};
 
static void vfs_mount_internal(ipc_callid_t rid, dev_handle_t dev_handle,
    fs_handle_t fs_handle, char *mp, char *opts)
{
    vfs_lookup_res_t mp_res;
    vfs_node_t *mp_node = NULL;
    ipcarg_t rc;
    int phone;
    aid_t msg;
    ipc_call_t answer;
 
    /* Resolve the path to the mountpoint. */
    futex_down(&rootfs_futex);
    if (rootfs.fs_handle) {
        /* We already have the root FS. */
        rwlock_write_lock(&namespace_rwlock);
        if (str_cmp(mp, "/") == 0) {
            /* Trying to mount root FS over root FS */
            rwlock_write_unlock(&namespace_rwlock);
            futex_up(&rootfs_futex);
            ipc_answer_0(rid, EBUSY);
            return;
        }
       
        rc = vfs_lookup_internal(mp, L_DIRECTORY, &mp_res, NULL);
        if (rc != EOK) {
            /* The lookup failed for some reason. */
            rwlock_write_unlock(&namespace_rwlock);
            futex_up(&rootfs_futex);
            ipc_answer_0(rid, rc);
            return;
        }
       
        mp_node = vfs_node_get(&mp_res);
        if (!mp_node) {
            rwlock_write_unlock(&namespace_rwlock);
            futex_up(&rootfs_futex);
            ipc_answer_0(rid, ENOMEM);
            return;
        }
       
        /*
         * Now we hold a reference to mp_node.
         * It will be dropped upon the corresponding VFS_UNMOUNT.
         * This prevents the mount point from being deleted.
         */
        rwlock_write_unlock(&namespace_rwlock);
    } else {
        /* We still don't have the root file system mounted. */
        if (str_cmp(mp, "/") == 0) {
            vfs_lookup_res_t mr_res;
            vfs_node_t *mr_node;
            fs_index_t rindex;
            size_t rsize;
            unsigned rlnkcnt;
           
            /*
             * For this simple, but important case,
             * we are almost done.
             */
           
            /* Tell the mountee that it is being mounted. */
            phone = vfs_grab_phone(fs_handle);
            msg = async_send_1(phone, VFS_MOUNTED,
                (ipcarg_t) dev_handle, &answer);
            /* send the mount options */
            rc = ipc_data_write_start(phone, (void *)opts,
                str_size(opts));
            if (rc != EOK) {
                async_wait_for(msg, NULL);
                vfs_release_phone(phone);
                futex_up(&rootfs_futex);
                ipc_answer_0(rid, rc);
                return;
            }
            async_wait_for(msg, &rc);
            vfs_release_phone(phone);
           
            if (rc != EOK) {
                futex_up(&rootfs_futex);
                ipc_answer_0(rid, rc);
                return;
            }
 
            rindex = (fs_index_t) IPC_GET_ARG1(answer);
            rsize = (size_t) IPC_GET_ARG2(answer);
            rlnkcnt = (unsigned) IPC_GET_ARG3(answer);
           
            mr_res.triplet.fs_handle = fs_handle;
            mr_res.triplet.dev_handle = dev_handle;
            mr_res.triplet.index = rindex;
            mr_res.size = rsize;
            mr_res.lnkcnt = rlnkcnt;
            mr_res.type = VFS_NODE_DIRECTORY;
           
            rootfs.fs_handle = fs_handle;
            rootfs.dev_handle = dev_handle;
            futex_up(&rootfs_futex);
           
            /* Add reference to the mounted root. */
            mr_node = vfs_node_get(&mr_res);
            assert(mr_node);
           
            ipc_answer_0(rid, rc);
            return;
        } else {
            /*
             * We can't resolve this without the root filesystem
             * being mounted first.
             */
            futex_up(&rootfs_futex);
            ipc_answer_0(rid, ENOENT);
            return;
        }
    }
    futex_up(&rootfs_futex);
   
    /*
     * At this point, we have all necessary pieces: file system and device
     * handles, and we know the mount point VFS node.
     */
   
    phone = vfs_grab_phone(mp_res.triplet.fs_handle);
    msg = async_send_4(phone, VFS_MOUNT,
        (ipcarg_t) mp_res.triplet.dev_handle,
        (ipcarg_t) mp_res.triplet.index,
        (ipcarg_t) fs_handle,
        (ipcarg_t) dev_handle, &answer);
    /* send the mount options */
    rc = ipc_data_write_start(phone, (void *)opts, str_size(opts));
    if (rc != EOK) {
        async_wait_for(msg, NULL);
        vfs_release_phone(phone);
        /* Mount failed, drop reference to mp_node. */
        if (mp_node)
            vfs_node_put(mp_node);
        ipc_answer_0(rid, rc);
        return;
    }
    async_wait_for(msg, &rc);
    vfs_release_phone(phone);
   
    if (rc != EOK) {
        /* Mount failed, drop reference to mp_node. */
        if (mp_node)
            vfs_node_put(mp_node);
    }
   
    ipc_answer_0(rid, rc);
}
 
/** Process pending mount requests */
void vfs_process_pending_mount()
{
    link_t *cur;
   
loop:
    for (cur = pending_req.next; cur != &pending_req; cur = cur->next) {
        pending_req_t *pr = list_get_instance(cur, pending_req_t, link);
       
        fs_handle_t fs_handle = fs_name_to_handle(pr->fs_name, true);
        if (!fs_handle)
            continue;
       
        /* Acknowledge that we know fs_name. */
        ipc_answer_0(pr->callid, EOK);
       
        /* Do the mount */
        vfs_mount_internal(pr->rid, pr->dev_handle, fs_handle, pr->mp,
            pr->opts);
       
        free(pr->fs_name);
        free(pr->mp);
        free(pr->opts);
        list_remove(cur);
        free(pr);
        goto loop;
    }
}
 
void vfs_mount(ipc_callid_t rid, ipc_call_t *request)
{
    /*
     * We expect the library to do the device-name to device-handle
     * translation for us, thus the device handle will arrive as ARG1
     * in the request.
     */
    dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request);
   
    /*
     * Mount flags are passed as ARG2.
     */
    unsigned int flags = (unsigned int) IPC_GET_ARG2(*request);
   
    /*
     * For now, don't make use of ARG3, but it can be used to
     * carry mount options in the future.
     */
   
    /* We want the client to send us the mount point. */
    ipc_callid_t callid;
    size_t size;
    if (!ipc_data_write_receive(&callid, &size)) {
        ipc_answer_0(callid, EINVAL);
        ipc_answer_0(rid, EINVAL);
        return;
    }
   
    /* Check whether size is reasonable wrt. the mount point. */
    if ((size < 1) || (size > MAX_PATH_LEN)) {
        ipc_answer_0(callid, EINVAL);
        ipc_answer_0(rid, EINVAL);
        return;
    }
   
    /* Allocate buffer for the mount point data being received. */
    char *mp = malloc(size + 1);
    if (!mp) {
        ipc_answer_0(callid, ENOMEM);
        ipc_answer_0(rid, ENOMEM);
        return;
    }
   
    /* Deliver the mount point. */
    ipcarg_t retval = ipc_data_write_finalize(callid, mp, size);
    if (retval != EOK) {
        ipc_answer_0(rid, retval);
        free(mp);
        return;
    }
    mp[size] = '\0';
   
    /* Now we expect to receive the mount options. */
    if (!ipc_data_write_receive(&callid, &size)) {
        ipc_answer_0(callid, EINVAL);
        ipc_answer_0(rid, EINVAL);
        free(mp);
        return;
    }
 
    /* Check the offered options size. */
    if (size < 0 || size > MAX_MNTOPTS_LEN) {
        ipc_answer_0(callid, EINVAL);
        ipc_answer_0(rid, EINVAL);
        free(mp);
        return;
    }
 
    /* Allocate buffer for the mount options. */
    char *opts = (char *) malloc(size + 1);
    if (!opts) {
        ipc_answer_0(callid, ENOMEM);
        ipc_answer_0(rid, ENOMEM);
        free(mp);
        return;
    }
 
    /* Deliver the mount options. */
    retval = ipc_data_write_finalize(callid, opts, size);
    if (retval != EOK) {
        ipc_answer_0(rid, retval);
        free(mp);
        free(opts);
        return;
    }
    opts[size] = '\0';
   
    /*
     * Now, we expect the client to send us data with the name of the file
     * system.
     */
    if (!ipc_data_write_receive(&callid, &size)) {
        ipc_answer_0(callid, EINVAL);
        ipc_answer_0(rid, EINVAL);
        free(mp);
        free(opts);
        return;
    }
   
    /*
     * Don't receive more than is necessary for storing a full file system
     * name.
     */
    if ((size < 1) || (size > FS_NAME_MAXLEN)) {
        ipc_answer_0(callid, EINVAL);
        ipc_answer_0(rid, EINVAL);
        free(mp);
        free(opts);
        return;
    }
   
    /*
     * Allocate buffer for file system name.
     */
    char *fs_name = (char *) malloc(size + 1);
    if (fs_name == NULL) {
        ipc_answer_0(callid, ENOMEM);
        ipc_answer_0(rid, ENOMEM);
        free(mp);
        free(opts);
        return;
    }
   
    /* Deliver the file system name. */
    retval = ipc_data_write_finalize(callid, fs_name, size);
    if (retval != EOK) {
        ipc_answer_0(rid, retval);
        free(mp);
        free(opts);
        free(fs_name);
        return;
    }
    fs_name[size] = '\0';
 
    /*
     * Wait for IPC_M_PING so that we can return an error if we don't know
     * fs_name.
     */
    ipc_call_t data;
    callid = async_get_call(&data);
    if (IPC_GET_METHOD(data) != IPC_M_PING) {
        ipc_answer_0(callid, ENOTSUP);
        ipc_answer_0(rid, ENOTSUP);
        free(mp);
        free(opts);
        free(fs_name);
        return;
    }
 
    /*
     * Check if we know a file system with the same name as is in fs_name.
     * This will also give us its file system handle.
     */
    fs_handle_t fs_handle = fs_name_to_handle(fs_name, true);
    if (!fs_handle) {
        if (flags & IPC_FLAG_BLOCKING) {
            pending_req_t *pr;
 
            /* Blocking mount, add to pending list */
            pr = (pending_req_t *) malloc(sizeof(pending_req_t));
            if (!pr) {
                ipc_answer_0(callid, ENOMEM);
                ipc_answer_0(rid, ENOMEM);
                free(mp);
                free(fs_name);
                free(opts);
                return;
            }
           
            pr->fs_name = fs_name;
            pr->mp = mp;
            pr->opts = opts;
            pr->callid = callid;
            pr->rid = rid;
            pr->dev_handle = dev_handle;
            link_initialize(&pr->link);
            list_append(&pr->link, &pending_req);
            return;
        }
       
        ipc_answer_0(callid, ENOENT);
        ipc_answer_0(rid, ENOENT);
        free(mp);
        free(fs_name);
        free(opts);
        return;
    }
   
    /* Acknowledge that we know fs_name. */
    ipc_answer_0(callid, EOK);
   
    /* Do the mount */
    vfs_mount_internal(rid, dev_handle, fs_handle, mp, opts);
    free(mp);
    free(fs_name);
    free(opts);
}
 
void vfs_open(ipc_callid_t rid, ipc_call_t *request)
{
    if (!vfs_files_init()) {
        ipc_answer_0(rid, ENOMEM);
        return;
    }
 
    /*
     * The POSIX interface is open(path, oflag, mode).
     * We can receive oflags and mode along with the VFS_OPEN call; the path
     * will need to arrive in another call.
     *
     * We also receive one private, non-POSIX set of flags called lflag
     * used to pass information to vfs_lookup_internal().
     */
    int lflag = IPC_GET_ARG1(*request);
    int oflag = IPC_GET_ARG2(*request);
    int mode = IPC_GET_ARG3(*request);
    size_t len;
 
    /*
     * Make sure that we are called with exactly one of L_FILE and
     * L_DIRECTORY.
     */
    if ((lflag & (L_FILE | L_DIRECTORY)) == 0 ||
        (lflag & (L_FILE | L_DIRECTORY)) == (L_FILE | L_DIRECTORY)) {
        ipc_answer_0(rid, EINVAL);
        return;
    }
 
    if (oflag & O_CREAT)
        lflag |= L_CREATE;
    if (oflag & O_EXCL)
        lflag |= L_EXCLUSIVE;
 
    ipc_callid_t callid;
 
    if (!ipc_data_write_receive(&callid, &len)) {
        ipc_answer_0(callid, EINVAL);
        ipc_answer_0(rid, EINVAL);
        return;
    }
    char *path = malloc(len + 1);
    if (!path) {
        ipc_answer_0(callid, ENOMEM);
        ipc_answer_0(rid, ENOMEM);
        return;
    }
    int rc;
    if ((rc = ipc_data_write_finalize(callid, path, len))) {
        ipc_answer_0(rid, rc);
        free(path);
        return;
    }
    path[len] = '\0';
   
    /*
     * Avoid the race condition in which the file can be deleted before we
     * find/create-and-lock the VFS node corresponding to the looked-up
     * triplet.
     */
    if (lflag & L_CREATE)
        rwlock_write_lock(&namespace_rwlock);
    else
        rwlock_read_lock(&namespace_rwlock);
 
    /* The path is now populated and we can call vfs_lookup_internal(). */
    vfs_lookup_res_t lr;
    rc = vfs_lookup_internal(path, lflag, &lr, NULL);
    if (rc) {
        if (lflag & L_CREATE)
            rwlock_write_unlock(&namespace_rwlock);
        else
            rwlock_read_unlock(&namespace_rwlock);
        ipc_answer_0(rid, rc);
        free(path);
        return;
    }
 
    /* Path is no longer needed. */
    free(path);
 
    vfs_node_t *node = vfs_node_get(&lr);
    if (lflag & L_CREATE)
        rwlock_write_unlock(&namespace_rwlock);
    else
        rwlock_read_unlock(&namespace_rwlock);
 
    /* Truncate the file if requested and if necessary. */
    if (oflag & O_TRUNC) {
        rwlock_write_lock(&node->contents_rwlock);
        if (node->size) {
            rc = vfs_truncate_internal(node->fs_handle,
                node->dev_handle, node->index, 0);
            if (rc) {
                rwlock_write_unlock(&node->contents_rwlock);
                vfs_node_put(node);
                ipc_answer_0(rid, rc);
                return;
            }
            node->size = 0;
        }
        rwlock_write_unlock(&node->contents_rwlock);
    }
 
    /*
     * Get ourselves a file descriptor and the corresponding vfs_file_t
     * structure.
     */
    int fd = vfs_fd_alloc();
    if (fd < 0) {
        vfs_node_put(node);
        ipc_answer_0(rid, fd);
        return;
    }
    vfs_file_t *file = vfs_file_get(fd);
    file->node = node;
    if (oflag & O_APPEND)
        file->append = true;
 
    /*
     * The following increase in reference count is for the fact that the
     * file is being opened and that a file structure is pointing to it.
     * It is necessary so that the file will not disappear when
     * vfs_node_put() is called. The reference will be dropped by the
     * respective VFS_CLOSE.
     */
    vfs_node_addref(node);
    vfs_node_put(node);
 
    /* Success! Return the new file descriptor to the client. */
    ipc_answer_1(rid, EOK, fd);
}
 
void vfs_close(ipc_callid_t rid, ipc_call_t *request)
{
    int fd = IPC_GET_ARG1(*request);
    int rc = vfs_fd_free(fd);
    ipc_answer_0(rid, rc);
}
 
static void vfs_rdwr(ipc_callid_t rid, ipc_call_t *request, bool read)
{
 
    /*
     * The following code strongly depends on the fact that the files data
     * structure can be only accessed by a single fibril and all file
     * operations are serialized (i.e. the reads and writes cannot
     * interleave and a file cannot be closed while it is being read).
     *
     * Additional synchronization needs to be added once the table of
     * open files supports parallel access!
     */
 
    int fd = IPC_GET_ARG1(*request);
   
    /* Lookup the file structure corresponding to the file descriptor. */
    vfs_file_t *file = vfs_file_get(fd);
    if (!file) {
        ipc_answer_0(rid, ENOENT);
        return;
    }
   
    /*
     * Now we need to receive a call with client's
     * IPC_M_DATA_READ/IPC_M_DATA_WRITE request.
     */
    ipc_callid_t callid;
    int res;
    if (read)
        res = ipc_data_read_receive(&callid, NULL);
    else
        res = ipc_data_write_receive(&callid, NULL);
    if (!res) {
        ipc_answer_0(callid, EINVAL);
        ipc_answer_0(rid, EINVAL);
        return;
    }
   
    /*
     * Lock the open file structure so that no other thread can manipulate
     * the same open file at a time.
     */
    futex_down(&file->lock);
 
    /*
     * Lock the file's node so that no other client can read/write to it at
     * the same time.
     */
    if (read)
        rwlock_read_lock(&file->node->contents_rwlock);
    else
        rwlock_write_lock(&file->node->contents_rwlock);
 
    if (file->node->type == VFS_NODE_DIRECTORY) {
        /*
         * Make sure that no one is modifying the namespace
         * while we are in readdir().
         */
        assert(read);
        rwlock_read_lock(&namespace_rwlock);
    }
   
    int fs_phone = vfs_grab_phone(file->node->fs_handle);  
   
    /* Make a VFS_READ/VFS_WRITE request at the destination FS server. */
    aid_t msg;
    ipc_call_t answer;
    if (!read && file->append)
        file->pos = file->node->size;
    msg = async_send_3(fs_phone, IPC_GET_METHOD(*request),
        file->node->dev_handle, file->node->index, file->pos, &answer);
   
    /*
     * Forward the IPC_M_DATA_READ/IPC_M_DATA_WRITE request to the
     * destination FS server. The call will be routed as if sent by
     * ourselves. Note that call arguments are immutable in this case so we
     * don't have to bother.
     */
    ipc_forward_fast(callid, fs_phone, 0, 0, 0, IPC_FF_ROUTE_FROM_ME);
   
    vfs_release_phone(fs_phone);
   
    /* Wait for reply from the FS server. */
    ipcarg_t rc;
    async_wait_for(msg, &rc);
    size_t bytes = IPC_GET_ARG1(answer);
 
    if (file->node->type == VFS_NODE_DIRECTORY)
        rwlock_read_unlock(&namespace_rwlock);
   
    /* Unlock the VFS node. */
    if (read)
        rwlock_read_unlock(&file->node->contents_rwlock);
    else {
        /* Update the cached version of node's size. */
        if (rc == EOK)
            file->node->size = IPC_GET_ARG2(answer);
        rwlock_write_unlock(&file->node->contents_rwlock);
    }
   
    /* Update the position pointer and unlock the open file. */
    if (rc == EOK)
        file->pos += bytes;
    futex_up(&file->lock);
   
    /*
     * FS server's reply is the final result of the whole operation we
     * return to the client.
     */
    ipc_answer_1(rid, rc, bytes);
}
 
void vfs_read(ipc_callid_t rid, ipc_call_t *request)
{
    vfs_rdwr(rid, request, true);
}
 
void vfs_write(ipc_callid_t rid, ipc_call_t *request)
{
    vfs_rdwr(rid, request, false);
}
 
void vfs_seek(ipc_callid_t rid, ipc_call_t *request)
{
    int fd = (int) IPC_GET_ARG1(*request);
    off_t off = (off_t) IPC_GET_ARG2(*request);
    int whence = (int) IPC_GET_ARG3(*request);
 
 
    /* Lookup the file structure corresponding to the file descriptor. */
    vfs_file_t *file = vfs_file_get(fd);
    if (!file) {
        ipc_answer_0(rid, ENOENT);
        return;
    }
 
    off_t newpos;
    futex_down(&file->lock);
    if (whence == SEEK_SET) {
        file->pos = off;
        futex_up(&file->lock);
        ipc_answer_1(rid, EOK, off);
        return;
    }
    if (whence == SEEK_CUR) {
        if (file->pos + off < file->pos) {
            futex_up(&file->lock);
            ipc_answer_0(rid, EOVERFLOW);
            return;
        }
        file->pos += off;
        newpos = file->pos;
        futex_up(&file->lock);
        ipc_answer_1(rid, EOK, newpos);
        return;
    }
    if (whence == SEEK_END) {
        rwlock_read_lock(&file->node->contents_rwlock);
        size_t size = file->node->size;
        rwlock_read_unlock(&file->node->contents_rwlock);
        if (size + off < size) {
            futex_up(&file->lock);
            ipc_answer_0(rid, EOVERFLOW);
            return;
        }
        newpos = size + off;
        futex_up(&file->lock);
        ipc_answer_1(rid, EOK, newpos);
        return;
    }
    futex_up(&file->lock);
    ipc_answer_0(rid, EINVAL);
}
 
int
vfs_truncate_internal(fs_handle_t fs_handle, dev_handle_t dev_handle,
    fs_index_t index, size_t size)
{
    ipcarg_t rc;
    int fs_phone;
   
    fs_phone = vfs_grab_phone(fs_handle);
    rc = async_req_3_0(fs_phone, VFS_TRUNCATE, (ipcarg_t)dev_handle,
        (ipcarg_t)index, (ipcarg_t)size);
    vfs_release_phone(fs_phone);
    return (int)rc;
}
 
void vfs_truncate(ipc_callid_t rid, ipc_call_t *request)
{
    int fd = IPC_GET_ARG1(*request);
    size_t size = IPC_GET_ARG2(*request);
    int rc;
 
    vfs_file_t *file = vfs_file_get(fd);
    if (!file) {
        ipc_answer_0(rid, ENOENT);
        return;
    }
    futex_down(&file->lock);
 
    rwlock_write_lock(&file->node->contents_rwlock);
    rc = vfs_truncate_internal(file->node->fs_handle,
        file->node->dev_handle, file->node->index, size);
    if (rc == EOK)
        file->node->size = size;
    rwlock_write_unlock(&file->node->contents_rwlock);
 
    futex_up(&file->lock);
    ipc_answer_0(rid, (ipcarg_t)rc);
}
 
void vfs_mkdir(ipc_callid_t rid, ipc_call_t *request)
{
    int mode = IPC_GET_ARG1(*request);
 
    size_t len;
    ipc_callid_t callid;
 
    if (!ipc_data_write_receive(&callid, &len)) {
        ipc_answer_0(callid, EINVAL);
        ipc_answer_0(rid, EINVAL);
        return;
    }
    char *path = malloc(len + 1);
    if (!path) {
        ipc_answer_0(callid, ENOMEM);
        ipc_answer_0(rid, ENOMEM);
        return;
    }
    int rc;
    if ((rc = ipc_data_write_finalize(callid, path, len))) {
        ipc_answer_0(rid, rc);
        free(path);
        return;
    }
    path[len] = '\0';
   
    rwlock_write_lock(&namespace_rwlock);
    int lflag = L_DIRECTORY | L_CREATE | L_EXCLUSIVE;
    rc = vfs_lookup_internal(path, lflag, NULL, NULL);
    rwlock_write_unlock(&namespace_rwlock);
    free(path);
    ipc_answer_0(rid, rc);
}
 
void vfs_unlink(ipc_callid_t rid, ipc_call_t *request)
{
    int lflag = IPC_GET_ARG1(*request);
 
    size_t len;
    ipc_callid_t callid;
 
    if (!ipc_data_write_receive(&callid, &len)) {
        ipc_answer_0(callid, EINVAL);
        ipc_answer_0(rid, EINVAL);
        return;
    }
    char *path = malloc(len + 1);
    if (!path) {
        ipc_answer_0(callid, ENOMEM);
        ipc_answer_0(rid, ENOMEM);
        return;
    }
    int rc;
    if ((rc = ipc_data_write_finalize(callid, path, len))) {
        ipc_answer_0(rid, rc);
        free(path);
        return;
    }
    path[len] = '\0';
   
    rwlock_write_lock(&namespace_rwlock);
    lflag &= L_DIRECTORY;   /* sanitize lflag */
    vfs_lookup_res_t lr;
    rc = vfs_lookup_internal(path, lflag | L_UNLINK, &lr, NULL);
    free(path);
    if (rc != EOK) {
        rwlock_write_unlock(&namespace_rwlock);
        ipc_answer_0(rid, rc);
        return;
    }
 
    /*
     * The name has already been unlinked by vfs_lookup_internal().
     * We have to get and put the VFS node to ensure that it is
     * VFS_DESTROY'ed after the last reference to it is dropped.
     */
    vfs_node_t *node = vfs_node_get(&lr);
    futex_down(&nodes_futex);
    node->lnkcnt--;
    futex_up(&nodes_futex);
    rwlock_write_unlock(&namespace_rwlock);
    vfs_node_put(node);
    ipc_answer_0(rid, EOK);
}
 
void vfs_rename(ipc_callid_t rid, ipc_call_t *request)
{
    size_t olen, nlen;
    ipc_callid_t callid;
    int rc;
 
    /* Retrieve the old path. */
    if (!ipc_data_write_receive(&callid, &olen)) {
        ipc_answer_0(callid, EINVAL);
        ipc_answer_0(rid, EINVAL);
        return;
    }
    char *old = malloc(olen + 1);
    if (!old) {
        ipc_answer_0(callid, ENOMEM);
        ipc_answer_0(rid, ENOMEM);
        return;
    }
    if ((rc = ipc_data_write_finalize(callid, old, olen))) {
        ipc_answer_0(rid, rc);
        free(old);
        return;
    }
    old[olen] = '\0';
   
    /* Retrieve the new path. */
    if (!ipc_data_write_receive(&callid, &nlen)) {
        ipc_answer_0(callid, EINVAL);
        ipc_answer_0(rid, EINVAL);
        free(old);
        return;
    }
    char *new = malloc(nlen + 1);
    if (!new) {
        ipc_answer_0(callid, ENOMEM);
        ipc_answer_0(rid, ENOMEM);
        free(old);
        return;
    }
    if ((rc = ipc_data_write_finalize(callid, new, nlen))) {
        ipc_answer_0(rid, rc);
        free(old);
        free(new);
        return;
    }
    new[nlen] = '\0';
 
    char *oldc = canonify(old, &olen);
    char *newc = canonify(new, &nlen);
    if (!oldc || !newc) {
        ipc_answer_0(rid, EINVAL);
        free(old);
        free(new);
        return;
    }
    oldc[olen] = '\0';
    newc[nlen] = '\0';
    if ((!str_lcmp(newc, oldc, str_length(oldc))) &&
        ((newc[str_length(oldc)] == '/') ||
        (str_length(oldc) == 1) ||
        (str_length(oldc) == str_length(newc)))) {
            /*
         * oldc is a prefix of newc and either
         * - newc continues with a / where oldc ends, or
         * - oldc was / itself, or
         * - oldc and newc are equal.
         */
        ipc_answer_0(rid, EINVAL);
        free(old);
        free(new);
        return;
    }
   
    vfs_lookup_res_t old_lr;
    vfs_lookup_res_t new_lr;
    vfs_lookup_res_t new_par_lr;
    rwlock_write_lock(&namespace_rwlock);
    /* Lookup the node belonging to the old file name. */
    rc = vfs_lookup_internal(oldc, L_NONE, &old_lr, NULL);
    if (rc != EOK) {
        rwlock_write_unlock(&namespace_rwlock);
        ipc_answer_0(rid, rc);
        free(old);
        free(new);
        return;
    }
    vfs_node_t *old_node = vfs_node_get(&old_lr);
    if (!old_node) {
        rwlock_write_unlock(&namespace_rwlock);
        ipc_answer_0(rid, ENOMEM);
        free(old);
        free(new);
        return;
    }
    /* Determine the path to the parent of the node with the new name. */
    char *parentc = str_dup(newc);
    if (!parentc) {
        rwlock_write_unlock(&namespace_rwlock);
        ipc_answer_0(rid, rc);
        free(old);
        free(new);
        return;
    }
    char *lastsl = str_rchr(parentc + 1, L'/');
    if (lastsl)
        *lastsl = '\0';
    else
        parentc[1] = '\0';
    /* Lookup parent of the new file name. */
    rc = vfs_lookup_internal(parentc, L_NONE, &new_par_lr, NULL);
    free(parentc);  /* not needed anymore */
    if (rc != EOK) {
        rwlock_write_unlock(&namespace_rwlock);
        ipc_answer_0(rid, rc);
        free(old);
        free(new);
        return;
    }
    /* Check whether linking to the same file system instance. */
    if ((old_node->fs_handle != new_par_lr.triplet.fs_handle) ||
        (old_node->dev_handle != new_par_lr.triplet.dev_handle)) {
        rwlock_write_unlock(&namespace_rwlock);
        ipc_answer_0(rid, EXDEV);   /* different file systems */
        free(old);
        free(new);
        return;
    }
    /* Destroy the old link for the new name. */
    vfs_node_t *new_node = NULL;
    rc = vfs_lookup_internal(newc, L_UNLINK, &new_lr, NULL);
    switch (rc) {
    case ENOENT:
        /* simply not in our way */
        break;
    case EOK:
        new_node = vfs_node_get(&new_lr);
        if (!new_node) {
            rwlock_write_unlock(&namespace_rwlock);
            ipc_answer_0(rid, ENOMEM);
            free(old);
            free(new);
            return;
        }
        futex_down(&nodes_futex);
        new_node->lnkcnt--;
        futex_up(&nodes_futex);
        break;
    default:
        rwlock_write_unlock(&namespace_rwlock);
        ipc_answer_0(rid, ENOTEMPTY);
        free(old);
        free(new);
        return;
    }
    /* Create the new link for the new name. */
    rc = vfs_lookup_internal(newc, L_LINK, NULL, NULL, old_node->index);
    if (rc != EOK) {
        rwlock_write_unlock(&namespace_rwlock);
        if (new_node)
            vfs_node_put(new_node);
        ipc_answer_0(rid, rc);
        free(old);
        free(new);
        return;
    }
    futex_down(&nodes_futex);
    old_node->lnkcnt++;
    futex_up(&nodes_futex);
    /* Destroy the link for the old name. */
    rc = vfs_lookup_internal(oldc, L_UNLINK, NULL, NULL);
    if (rc != EOK) {
        rwlock_write_unlock(&namespace_rwlock);
        vfs_node_put(old_node);
        if (new_node)
            vfs_node_put(new_node);
        ipc_answer_0(rid, rc);
        free(old);
        free(new);
        return;
    }
    futex_down(&nodes_futex);
    old_node->lnkcnt--;
    futex_up(&nodes_futex);
    rwlock_write_unlock(&namespace_rwlock);
    vfs_node_put(old_node);
    if (new_node)
        vfs_node_put(new_node);
    free(old);
    free(new);
    ipc_answer_0(rid, EOK);
}
 
/**
 * @}
 */
 

Rev 4348	Rev 4389
1	/*	1	/*
2	* Copyright (c) 2008 Jakub Jermar	2	* Copyright (c) 2008 Jakub Jermar
3	* All rights reserved.	3	* All rights reserved.
4	*	4	*
5	* Redistribution and use in source and binary forms, with or without	5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions	6	* modification, are permitted provided that the following conditions
7	* are met:	7	* are met:
8	*	8	*
9	* - Redistributions of source code must retain the above copyright	9	* - Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.	10	* notice, this list of conditions and the following disclaimer.
11	* - Redistributions in binary form must reproduce the above copyright	11	* - Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the	12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.	13	* documentation and/or other materials provided with the distribution.
14	* - The name of the author may not be used to endorse or promote products	14	* - The name of the author may not be used to endorse or promote products
15	* derived from this software without specific prior written permission.	15	* derived from this software without specific prior written permission.
16	*	16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	/** @addtogroup fs	29	/** @addtogroup fs
30	* @{	30	* @{
31	*/	31	*/
32		32
33	/**	33	/**
34	* @file vfs_ops.c	34	* @file vfs_ops.c
35	* @brief Operations that VFS offers to its clients.	35	* @brief Operations that VFS offers to its clients.
36	*/	36	*/
37		37
38	#include "vfs.h"	38	#include "vfs.h"
39	#include <ipc/ipc.h>	39	#include <ipc/ipc.h>
40	#include <async.h>	40	#include <async.h>
41	#include <errno.h>	41	#include <errno.h>
42	#include <stdio.h>	42	#include <stdio.h>
43	#include <stdlib.h>	43	#include <stdlib.h>
44	#include <string.h>	44	#include <string.h>
45	#include <bool.h>	45	#include <bool.h>
46	#include <futex.h>	46	#include <futex.h>
47	#include <rwlock.h>	47	#include <rwlock.h>
48	#include <libadt/list.h>	48	#include <libadt/list.h>
49	#include <unistd.h>	49	#include <unistd.h>
50	#include <ctype.h>	50	#include <ctype.h>
51	#include <fcntl.h>	51	#include <fcntl.h>
52	#include <assert.h>	52	#include <assert.h>
53	#include <vfs/canonify.h>	53	#include <vfs/canonify.h>
54		54
55	/* Forward declarations of static functions. */	55	/* Forward declarations of static functions. */
56	static int vfs_truncate_internal(fs_handle_t, dev_handle_t, fs_index_t, size_t);	56	static int vfs_truncate_internal(fs_handle_t, dev_handle_t, fs_index_t, size_t);
57		57
58	/** Pending mount structure. */	58	/** Pending mount structure. */
59	typedef struct {	59	typedef struct {
60	link_t link;	60	link_t link;
61	char fs_name; /< File system name /	61	char fs_name; /< File system name /
62	char mp; /< Mount point /	62	char mp; /< Mount point /
63	char opts; /< Mount options. /	63	char opts; /< Mount options. /
64	ipc_callid_t callid; /*< Call ID waiting for the mount /	64	ipc_callid_t callid; /*< Call ID waiting for the mount /
65	ipc_callid_t rid; /*< Request ID /	65	ipc_callid_t rid; /*< Request ID /
66	dev_handle_t dev_handle; /*< Device handle /	66	dev_handle_t dev_handle; /*< Device handle /
67	} pending_req_t;	67	} pending_req_t;
68		68
69	LIST_INITIALIZE(pending_req);	69	LIST_INITIALIZE(pending_req);
70		70
71	/**	71	/**
72	* This rwlock prevents the race between a triplet-to-VFS-node resolution and a	72	* This rwlock prevents the race between a triplet-to-VFS-node resolution and a
73	* concurrent VFS operation which modifies the file system namespace.	73	* concurrent VFS operation which modifies the file system namespace.
74	*/	74	*/
75	RWLOCK_INITIALIZE(namespace_rwlock);	75	RWLOCK_INITIALIZE(namespace_rwlock);
76		76
77	futex_t rootfs_futex = FUTEX_INITIALIZER;	77	futex_t rootfs_futex = FUTEX_INITIALIZER;
78	vfs_pair_t rootfs = {	78	vfs_pair_t rootfs = {
79	.fs_handle = 0,	79	.fs_handle = 0,
80	.dev_handle = 0	80	.dev_handle = 0
81	};	81	};
82		82
83	static void vfs_mount_internal(ipc_callid_t rid, dev_handle_t dev_handle,	83	static void vfs_mount_internal(ipc_callid_t rid, dev_handle_t dev_handle,
84	fs_handle_t fs_handle, char mp, char opts)	84	fs_handle_t fs_handle, char mp, char opts)
85	{	85	{
86	vfs_lookup_res_t mp_res;	86	vfs_lookup_res_t mp_res;
87	vfs_node_t *mp_node = NULL;	87	vfs_node_t *mp_node = NULL;
88	ipcarg_t rc;	88	ipcarg_t rc;
89	int phone;	89	int phone;
90	aid_t msg;	90	aid_t msg;
91	ipc_call_t answer;	91	ipc_call_t answer;
92		92
93	/* Resolve the path to the mountpoint. */	93	/* Resolve the path to the mountpoint. */
94	futex_down(&rootfs_futex);	94	futex_down(&rootfs_futex);
95	if (rootfs.fs_handle) {	95	if (rootfs.fs_handle) {
96	/* We already have the root FS. */	96	/* We already have the root FS. */
97	rwlock_write_lock(&namespace_rwlock);	97	rwlock_write_lock(&namespace_rwlock);
98	if (str_cmp(mp, "/") == 0) {	98	if (str_cmp(mp, "/") == 0) {
99	/* Trying to mount root FS over root FS */	99	/* Trying to mount root FS over root FS */
100	rwlock_write_unlock(&namespace_rwlock);	100	rwlock_write_unlock(&namespace_rwlock);
101	futex_up(&rootfs_futex);	101	futex_up(&rootfs_futex);
102	ipc_answer_0(rid, EBUSY);	102	ipc_answer_0(rid, EBUSY);
103	return;	103	return;
104	}	104	}
105		105
106	rc = vfs_lookup_internal(mp, L_DIRECTORY, &mp_res, NULL);	106	rc = vfs_lookup_internal(mp, L_DIRECTORY, &mp_res, NULL);
107	if (rc != EOK) {	107	if (rc != EOK) {
108	/* The lookup failed for some reason. */	108	/* The lookup failed for some reason. */
109	rwlock_write_unlock(&namespace_rwlock);	109	rwlock_write_unlock(&namespace_rwlock);
110	futex_up(&rootfs_futex);	110	futex_up(&rootfs_futex);
111	ipc_answer_0(rid, rc);	111	ipc_answer_0(rid, rc);
112	return;	112	return;
113	}	113	}
114		114
115	mp_node = vfs_node_get(&mp_res);	115	mp_node = vfs_node_get(&mp_res);
116	if (!mp_node) {	116	if (!mp_node) {
117	rwlock_write_unlock(&namespace_rwlock);	117	rwlock_write_unlock(&namespace_rwlock);
118	futex_up(&rootfs_futex);	118	futex_up(&rootfs_futex);
119	ipc_answer_0(rid, ENOMEM);	119	ipc_answer_0(rid, ENOMEM);
120	return;	120	return;
121	}	121	}
122		122
123	/*	123	/*
124	* Now we hold a reference to mp_node.	124	* Now we hold a reference to mp_node.
125	* It will be dropped upon the corresponding VFS_UNMOUNT.	125	* It will be dropped upon the corresponding VFS_UNMOUNT.
126	* This prevents the mount point from being deleted.	126	* This prevents the mount point from being deleted.
127	*/	127	*/
128	rwlock_write_unlock(&namespace_rwlock);	128	rwlock_write_unlock(&namespace_rwlock);
129	} else {	129	} else {
130	/* We still don't have the root file system mounted. */	130	/* We still don't have the root file system mounted. */
131	if (str_cmp(mp, "/") == 0) {	131	if (str_cmp(mp, "/") == 0) {
132	vfs_lookup_res_t mr_res;	132	vfs_lookup_res_t mr_res;
133	vfs_node_t *mr_node;	133	vfs_node_t *mr_node;
134	fs_index_t rindex;	134	fs_index_t rindex;
135	size_t rsize;	135	size_t rsize;
136	unsigned rlnkcnt;	136	unsigned rlnkcnt;
137		137
138	/*	138	/*
139	* For this simple, but important case,	139	* For this simple, but important case,
140	* we are almost done.	140	* we are almost done.
141	*/	141	*/
142		142
143	/* Tell the mountee that it is being mounted. */	143	/* Tell the mountee that it is being mounted. */
144	phone = vfs_grab_phone(fs_handle);	144	phone = vfs_grab_phone(fs_handle);
145	msg = async_send_1(phone, VFS_MOUNTED,	145	msg = async_send_1(phone, VFS_MOUNTED,
146	(ipcarg_t) dev_handle, &answer);	146	(ipcarg_t) dev_handle, &answer);
147	/* send the mount options */	147	/* send the mount options */
148	rc = ipc_data_write_start(phone, (void *)opts,	148	rc = ipc_data_write_start(phone, (void *)opts,
149	str_size(opts));	149	str_size(opts));
150	if (rc != EOK) {	150	if (rc != EOK) {
151	async_wait_for(msg, NULL);	151	async_wait_for(msg, NULL);
152	vfs_release_phone(phone);	152	vfs_release_phone(phone);
153	futex_up(&rootfs_futex);	153	futex_up(&rootfs_futex);
154	ipc_answer_0(rid, rc);	154	ipc_answer_0(rid, rc);
155	return;	155	return;
156	}	156	}
157	async_wait_for(msg, &rc);	157	async_wait_for(msg, &rc);
158	vfs_release_phone(phone);	158	vfs_release_phone(phone);
159		159
160	if (rc != EOK) {	160	if (rc != EOK) {
161	futex_up(&rootfs_futex);	161	futex_up(&rootfs_futex);
162	ipc_answer_0(rid, rc);	162	ipc_answer_0(rid, rc);
163	return;	163	return;
164	}	164	}
165		165
166	rindex = (fs_index_t) IPC_GET_ARG1(answer);	166	rindex = (fs_index_t) IPC_GET_ARG1(answer);
167	rsize = (size_t) IPC_GET_ARG2(answer);	167	rsize = (size_t) IPC_GET_ARG2(answer);
168	rlnkcnt = (unsigned) IPC_GET_ARG3(answer);	168	rlnkcnt = (unsigned) IPC_GET_ARG3(answer);
169		169
170	mr_res.triplet.fs_handle = fs_handle;	170	mr_res.triplet.fs_handle = fs_handle;
171	mr_res.triplet.dev_handle = dev_handle;	171	mr_res.triplet.dev_handle = dev_handle;
172	mr_res.triplet.index = rindex;	172	mr_res.triplet.index = rindex;
173	mr_res.size = rsize;	173	mr_res.size = rsize;
174	mr_res.lnkcnt = rlnkcnt;	174	mr_res.lnkcnt = rlnkcnt;
175	mr_res.type = VFS_NODE_DIRECTORY;	175	mr_res.type = VFS_NODE_DIRECTORY;
176		176
177	rootfs.fs_handle = fs_handle;	177	rootfs.fs_handle = fs_handle;
178	rootfs.dev_handle = dev_handle;	178	rootfs.dev_handle = dev_handle;
179	futex_up(&rootfs_futex);	179	futex_up(&rootfs_futex);
180		180
181	/* Add reference to the mounted root. */	181	/* Add reference to the mounted root. */
182	mr_node = vfs_node_get(&mr_res);	182	mr_node = vfs_node_get(&mr_res);
183	assert(mr_node);	183	assert(mr_node);
184		184
185	ipc_answer_0(rid, rc);	185	ipc_answer_0(rid, rc);
186	return;	186	return;
187	} else {	187	} else {
188	/*	188	/*
189	* We can't resolve this without the root filesystem	189	* We can't resolve this without the root filesystem
190	* being mounted first.	190	* being mounted first.
191	*/	191	*/
192	futex_up(&rootfs_futex);	192	futex_up(&rootfs_futex);
193	ipc_answer_0(rid, ENOENT);	193	ipc_answer_0(rid, ENOENT);
194	return;	194	return;
195	}	195	}
196	}	196	}
197	futex_up(&rootfs_futex);	197	futex_up(&rootfs_futex);
198		198
199	/*	199	/*
200	* At this point, we have all necessary pieces: file system and device	200	* At this point, we have all necessary pieces: file system and device
201	* handles, and we know the mount point VFS node.	201	* handles, and we know the mount point VFS node.
202	*/	202	*/
203		203
204	phone = vfs_grab_phone(mp_res.triplet.fs_handle);	204	phone = vfs_grab_phone(mp_res.triplet.fs_handle);
205	msg = async_send_4(phone, VFS_MOUNT,	205	msg = async_send_4(phone, VFS_MOUNT,
206	(ipcarg_t) mp_res.triplet.dev_handle,	206	(ipcarg_t) mp_res.triplet.dev_handle,
207	(ipcarg_t) mp_res.triplet.index,	207	(ipcarg_t) mp_res.triplet.index,
208	(ipcarg_t) fs_handle,	208	(ipcarg_t) fs_handle,
209	(ipcarg_t) dev_handle, &answer);	209	(ipcarg_t) dev_handle, &answer);
210	/* send the mount options */	210	/* send the mount options */
211	rc = ipc_data_write_start(phone, (void *)opts, str_size(opts));	211	rc = ipc_data_write_start(phone, (void *)opts, str_size(opts));
212	if (rc != EOK) {	212	if (rc != EOK) {
213	async_wait_for(msg, NULL);	213	async_wait_for(msg, NULL);
214	vfs_release_phone(phone);	214	vfs_release_phone(phone);
215	/* Mount failed, drop reference to mp_node. */	215	/* Mount failed, drop reference to mp_node. */
216	if (mp_node)	216	if (mp_node)
217	vfs_node_put(mp_node);	217	vfs_node_put(mp_node);
218	ipc_answer_0(rid, rc);	218	ipc_answer_0(rid, rc);
219	return;	219	return;
220	}	220	}
221	async_wait_for(msg, &rc);	221	async_wait_for(msg, &rc);
222	vfs_release_phone(phone);	222	vfs_release_phone(phone);
223		223
224	if (rc != EOK) {	224	if (rc != EOK) {
225	/* Mount failed, drop reference to mp_node. */	225	/* Mount failed, drop reference to mp_node. */
226	if (mp_node)	226	if (mp_node)
227	vfs_node_put(mp_node);	227	vfs_node_put(mp_node);
228	}	228	}
229		229
230	ipc_answer_0(rid, rc);	230	ipc_answer_0(rid, rc);
231	}	231	}
232		232
233	/** Process pending mount requests */	233	/** Process pending mount requests */
234	void vfs_process_pending_mount()	234	void vfs_process_pending_mount()
235	{	235	{
236	link_t *cur;	236	link_t *cur;
237		237
238	loop:	238	loop:
239	for (cur = pending_req.next; cur != &pending_req; cur = cur->next) {	239	for (cur = pending_req.next; cur != &pending_req; cur = cur->next) {
240	pending_req_t *pr = list_get_instance(cur, pending_req_t, link);	240	pending_req_t *pr = list_get_instance(cur, pending_req_t, link);
241		241
242	fs_handle_t fs_handle = fs_name_to_handle(pr->fs_name, true);	242	fs_handle_t fs_handle = fs_name_to_handle(pr->fs_name, true);
243	if (!fs_handle)	243	if (!fs_handle)
244	continue;	244	continue;
245		245
246	/* Acknowledge that we know fs_name. */	246	/* Acknowledge that we know fs_name. */
247	ipc_answer_0(pr->callid, EOK);	247	ipc_answer_0(pr->callid, EOK);
248		248
249	/* Do the mount */	249	/* Do the mount */
250	vfs_mount_internal(pr->rid, pr->dev_handle, fs_handle, pr->mp,	250	vfs_mount_internal(pr->rid, pr->dev_handle, fs_handle, pr->mp,
251	pr->opts);	251	pr->opts);
252		252
253	free(pr->fs_name);	253	free(pr->fs_name);
254	free(pr->mp);	254	free(pr->mp);
255	free(pr->opts);	255	free(pr->opts);
256	list_remove(cur);	256	list_remove(cur);
257	free(pr);	257	free(pr);
258	goto loop;	258	goto loop;
259	}	259	}
260	}	260	}
261		261
262	void vfs_mount(ipc_callid_t rid, ipc_call_t *request)	262	void vfs_mount(ipc_callid_t rid, ipc_call_t *request)
263	{	263	{
264	/*	264	/*
265	* We expect the library to do the device-name to device-handle	265	* We expect the library to do the device-name to device-handle
266	* translation for us, thus the device handle will arrive as ARG1	266	* translation for us, thus the device handle will arrive as ARG1
267	* in the request.	267	* in the request.
268	*/	268	*/
269	dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request);	269	dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request);
270		270
271	/*	271	/*
272	* Mount flags are passed as ARG2.	272	* Mount flags are passed as ARG2.
273	*/	273	*/
274	unsigned int flags = (unsigned int) IPC_GET_ARG2(*request);	274	unsigned int flags = (unsigned int) IPC_GET_ARG2(*request);
275		275
276	/*	276	/*
277	* For now, don't make use of ARG3, but it can be used to	277	* For now, don't make use of ARG3, but it can be used to
278	* carry mount options in the future.	278	* carry mount options in the future.
279	*/	279	*/
280		280
281	/* We want the client to send us the mount point. */	281	/* We want the client to send us the mount point. */
282	ipc_callid_t callid;	282	ipc_callid_t callid;
283	size_t size;	283	size_t size;
284	if (!ipc_data_write_receive(&callid, &size)) {	284	if (!ipc_data_write_receive(&callid, &size)) {
285	ipc_answer_0(callid, EINVAL);	285	ipc_answer_0(callid, EINVAL);
286	ipc_answer_0(rid, EINVAL);	286	ipc_answer_0(rid, EINVAL);
287	return;	287	return;
288	}	288	}
289		289
290	/* Check whether size is reasonable wrt. the mount point. */	290	/* Check whether size is reasonable wrt. the mount point. */
291	if ((size < 1) \|\| (size > MAX_PATH_LEN)) {	291	if ((size < 1) \|\| (size > MAX_PATH_LEN)) {
292	ipc_answer_0(callid, EINVAL);	292	ipc_answer_0(callid, EINVAL);
293	ipc_answer_0(rid, EINVAL);	293	ipc_answer_0(rid, EINVAL);
294	return;	294	return;
295	}	295	}
296		296
297	/* Allocate buffer for the mount point data being received. */	297	/* Allocate buffer for the mount point data being received. */
298	char *mp = malloc(size + 1);	298	char *mp = malloc(size + 1);
299	if (!mp) {	299	if (!mp) {
300	ipc_answer_0(callid, ENOMEM);	300	ipc_answer_0(callid, ENOMEM);
301	ipc_answer_0(rid, ENOMEM);	301	ipc_answer_0(rid, ENOMEM);
302	return;	302	return;
303	}	303	}
304		304
305	/* Deliver the mount point. */	305	/* Deliver the mount point. */
306	ipcarg_t retval = ipc_data_write_finalize(callid, mp, size);	306	ipcarg_t retval = ipc_data_write_finalize(callid, mp, size);
307	if (retval != EOK) {	307	if (retval != EOK) {
308	ipc_answer_0(rid, retval);	308	ipc_answer_0(rid, retval);
309	free(mp);	309	free(mp);
310	return;	310	return;
311	}	311	}
312	mp[size] = '\0';	312	mp[size] = '\0';
313		313
314	/* Now we expect to receive the mount options. */	314	/* Now we expect to receive the mount options. */
315	if (!ipc_data_write_receive(&callid, &size)) {	315	if (!ipc_data_write_receive(&callid, &size)) {
316	ipc_answer_0(callid, EINVAL);	316	ipc_answer_0(callid, EINVAL);
317	ipc_answer_0(rid, EINVAL);	317	ipc_answer_0(rid, EINVAL);
318	free(mp);	318	free(mp);
319	return;	319	return;
320	}	320	}
321		321
322	/* Check the offered options size. */	322	/* Check the offered options size. */
323	if (size < 0 \|\| size > MAX_MNTOPTS_LEN) {	323	if (size < 0 \|\| size > MAX_MNTOPTS_LEN) {
324	ipc_answer_0(callid, EINVAL);	324	ipc_answer_0(callid, EINVAL);
325	ipc_answer_0(rid, EINVAL);	325	ipc_answer_0(rid, EINVAL);
326	free(mp);	326	free(mp);
327	return;	327	return;
328	}	328	}
329		329
330	/* Allocate buffer for the mount options. */	330	/* Allocate buffer for the mount options. */
331	char opts = (char ) malloc(size + 1);	331	char opts = (char ) malloc(size + 1);
332	if (!opts) {	332	if (!opts) {
333	ipc_answer_0(callid, ENOMEM);	333	ipc_answer_0(callid, ENOMEM);
334	ipc_answer_0(rid, ENOMEM);	334	ipc_answer_0(rid, ENOMEM);
335	free(mp);	335	free(mp);
336	return;	336	return;
337	}	337	}
338		338
339	/* Deliver the mount options. */	339	/* Deliver the mount options. */
340	retval = ipc_data_write_finalize(callid, opts, size);	340	retval = ipc_data_write_finalize(callid, opts, size);
341	if (retval != EOK) {	341	if (retval != EOK) {
342	ipc_answer_0(rid, retval);	342	ipc_answer_0(rid, retval);
343	free(mp);	343	free(mp);
344	free(opts);	344	free(opts);
345	return;	345	return;
346	}	346	}
347	opts[size] = '\0';	347	opts[size] = '\0';
348		348
349	/*	349	/*
350	* Now, we expect the client to send us data with the name of the file	350	* Now, we expect the client to send us data with the name of the file
351	* system.	351	* system.
352	*/	352	*/
353	if (!ipc_data_write_receive(&callid, &size)) {	353	if (!ipc_data_write_receive(&callid, &size)) {
354	ipc_answer_0(callid, EINVAL);	354	ipc_answer_0(callid, EINVAL);
355	ipc_answer_0(rid, EINVAL);	355	ipc_answer_0(rid, EINVAL);
356	free(mp);	356	free(mp);
357	free(opts);	357	free(opts);
358	return;	358	return;
359	}	359	}
360		360
361	/*	361	/*
362	* Don't receive more than is necessary for storing a full file system	362	* Don't receive more than is necessary for storing a full file system
363	* name.	363	* name.
364	*/	364	*/
365	if ((size < 1) \|\| (size > FS_NAME_MAXLEN)) {	365	if ((size < 1) \|\| (size > FS_NAME_MAXLEN)) {
366	ipc_answer_0(callid, EINVAL);	366	ipc_answer_0(callid, EINVAL);
367	ipc_answer_0(rid, EINVAL);	367	ipc_answer_0(rid, EINVAL);
368	free(mp);	368	free(mp);
369	free(opts);	369	free(opts);
370	return;	370	return;
371	}	371	}
372		372
373	/*	373	/*
374	* Allocate buffer for file system name.	374	* Allocate buffer for file system name.
375	*/	375	*/
376	char fs_name = (char ) malloc(size + 1);	376	char fs_name = (char ) malloc(size + 1);
377	if (fs_name == NULL) {	377	if (fs_name == NULL) {
378	ipc_answer_0(callid, ENOMEM);	378	ipc_answer_0(callid, ENOMEM);
379	ipc_answer_0(rid, ENOMEM);	379	ipc_answer_0(rid, ENOMEM);
380	free(mp);	380	free(mp);
381	free(opts);	381	free(opts);
382	return;	382	return;
383	}	383	}
384		384
385	/* Deliver the file system name. */	385	/* Deliver the file system name. */
386	retval = ipc_data_write_finalize(callid, fs_name, size);	386	retval = ipc_data_write_finalize(callid, fs_name, size);
387	if (retval != EOK) {	387	if (retval != EOK) {
388	ipc_answer_0(rid, retval);	388	ipc_answer_0(rid, retval);
389	free(mp);	389	free(mp);
390	free(opts);	390	free(opts);
391	free(fs_name);	391	free(fs_name);
392	return;	392	return;
393	}	393	}
394	fs_name[size] = '\0';	394	fs_name[size] = '\0';
395		395
396	/*	396	/*
397	* Wait for IPC_M_PING so that we can return an error if we don't know	397	* Wait for IPC_M_PING so that we can return an error if we don't know
398	* fs_name.	398	* fs_name.
399	*/	399	*/
400	ipc_call_t data;	400	ipc_call_t data;
401	callid = async_get_call(&data);	401	callid = async_get_call(&data);
402	if (IPC_GET_METHOD(data) != IPC_M_PING) {	402	if (IPC_GET_METHOD(data) != IPC_M_PING) {
403	ipc_answer_0(callid, ENOTSUP);	403	ipc_answer_0(callid, ENOTSUP);
404	ipc_answer_0(rid, ENOTSUP);	404	ipc_answer_0(rid, ENOTSUP);
405	free(mp);	405	free(mp);
406	free(opts);	406	free(opts);
407	free(fs_name);	407	free(fs_name);
408	return;	408	return;
409	}	409	}
410		410
411	/*	411	/*
412	* Check if we know a file system with the same name as is in fs_name.	412	* Check if we know a file system with the same name as is in fs_name.
413	* This will also give us its file system handle.	413	* This will also give us its file system handle.
414	*/	414	*/
415	fs_handle_t fs_handle = fs_name_to_handle(fs_name, true);	415	fs_handle_t fs_handle = fs_name_to_handle(fs_name, true);
416	if (!fs_handle) {	416	if (!fs_handle) {
417	if (flags & IPC_FLAG_BLOCKING) {	417	if (flags & IPC_FLAG_BLOCKING) {
418	pending_req_t *pr;	418	pending_req_t *pr;
419		419
420	/* Blocking mount, add to pending list */	420	/* Blocking mount, add to pending list */
421	pr = (pending_req_t *) malloc(sizeof(pending_req_t));	421	pr = (pending_req_t *) malloc(sizeof(pending_req_t));
422	if (!pr) {	422	if (!pr) {
423	ipc_answer_0(callid, ENOMEM);	423	ipc_answer_0(callid, ENOMEM);
424	ipc_answer_0(rid, ENOMEM);	424	ipc_answer_0(rid, ENOMEM);
425	free(mp);	425	free(mp);
426	free(fs_name);	426	free(fs_name);
427	free(opts);	427	free(opts);
428	return;	428	return;
429	}	429	}
430		430
431	pr->fs_name = fs_name;	431	pr->fs_name = fs_name;
432	pr->mp = mp;	432	pr->mp = mp;
433	pr->opts = opts;	433	pr->opts = opts;
434	pr->callid = callid;	434	pr->callid = callid;
435	pr->rid = rid;	435	pr->rid = rid;
436	pr->dev_handle = dev_handle;	436	pr->dev_handle = dev_handle;
437	link_initialize(&pr->link);	437	link_initialize(&pr->link);
438	list_append(&pr->link, &pending_req);	438	list_append(&pr->link, &pending_req);
439	return;	439	return;
440	}	440	}
441		441
442	ipc_answer_0(callid, ENOENT);	442	ipc_answer_0(callid, ENOENT);
443	ipc_answer_0(rid, ENOENT);	443	ipc_answer_0(rid, ENOENT);
444	free(mp);	444	free(mp);
445	free(fs_name);	445	free(fs_name);
446	free(opts);	446	free(opts);
447	return;	447	return;
448	}	448	}
449		449
450	/* Acknowledge that we know fs_name. */	450	/* Acknowledge that we know fs_name. */
451	ipc_answer_0(callid, EOK);	451	ipc_answer_0(callid, EOK);
452		452
453	/* Do the mount */	453	/* Do the mount */
454	vfs_mount_internal(rid, dev_handle, fs_handle, mp, opts);	454	vfs_mount_internal(rid, dev_handle, fs_handle, mp, opts);
455	free(mp);	455	free(mp);
456	free(fs_name);	456	free(fs_name);
457	free(opts);	457	free(opts);
458	}	458	}
459		459
460	void vfs_open(ipc_callid_t rid, ipc_call_t *request)	460	void vfs_open(ipc_callid_t rid, ipc_call_t *request)
461	{	461	{
462	if (!vfs_files_init()) {	462	if (!vfs_files_init()) {
463	ipc_answer_0(rid, ENOMEM);	463	ipc_answer_0(rid, ENOMEM);
464	return;	464	return;
465	}	465	}
466		466
467	/*	467	/*
468	* The POSIX interface is open(path, oflag, mode).	468	* The POSIX interface is open(path, oflag, mode).
469	* We can receive oflags and mode along with the VFS_OPEN call; the path	469	* We can receive oflags and mode along with the VFS_OPEN call; the path
470	* will need to arrive in another call.	470	* will need to arrive in another call.
471	*	471	*
472	* We also receive one private, non-POSIX set of flags called lflag	472	* We also receive one private, non-POSIX set of flags called lflag
473	* used to pass information to vfs_lookup_internal().	473	* used to pass information to vfs_lookup_internal().
474	*/	474	*/
475	int lflag = IPC_GET_ARG1(*request);	475	int lflag = IPC_GET_ARG1(*request);
476	int oflag = IPC_GET_ARG2(*request);	476	int oflag = IPC_GET_ARG2(*request);
477	int mode = IPC_GET_ARG3(*request);	477	int mode = IPC_GET_ARG3(*request);
478	size_t len;	478	size_t len;
479		479
480	/*	480	/*
481	* Make sure that we are called with exactly one of L_FILE and	481	* Make sure that we are called with exactly one of L_FILE and
482	* L_DIRECTORY.	482	* L_DIRECTORY.
483	*/	483	*/
484	if ((lflag & (L_FILE \| L_DIRECTORY)) == 0 \|\|	484	if ((lflag & (L_FILE \| L_DIRECTORY)) == 0 \|\|
485	(lflag & (L_FILE \| L_DIRECTORY)) == (L_FILE \| L_DIRECTORY)) {	485	(lflag & (L_FILE \| L_DIRECTORY)) == (L_FILE \| L_DIRECTORY)) {
486	ipc_answer_0(rid, EINVAL);	486	ipc_answer_0(rid, EINVAL);
487	return;	487	return;
488	}	488	}
489		489
490	if (oflag & O_CREAT)	490	if (oflag & O_CREAT)
491	lflag \|= L_CREATE;	491	lflag \|= L_CREATE;
492	if (oflag & O_EXCL)	492	if (oflag & O_EXCL)
493	lflag \|= L_EXCLUSIVE;	493	lflag \|= L_EXCLUSIVE;
494		494
495	ipc_callid_t callid;	495	ipc_callid_t callid;
496		496
497	if (!ipc_data_write_receive(&callid, &len)) {	497	if (!ipc_data_write_receive(&callid, &len)) {
498	ipc_answer_0(callid, EINVAL);	498	ipc_answer_0(callid, EINVAL);
499	ipc_answer_0(rid, EINVAL);	499	ipc_answer_0(rid, EINVAL);
500	return;	500	return;

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(root)/branches/dynload/uspace/srv/vfs/vfs_ops.c – Rev 4348 → 4389