WebSVN – HelenOS – Diff – /trunk/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 <fibril_sync.h>
#include <adt/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);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/**
 * This rwlock prevents the race between a triplet-to-VFS-node resolution and a
 * concurrent VFS operation which modifies the file system namespace.
 */
FIBRIL_RWLOCK_INITIALIZE(namespace_rwlock);
 
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_lookup_res_t mr_res;
    vfs_node_t *mp_node = NULL;
    vfs_node_t *mr_node;
    fs_index_t rindex;
    size_t rsize;
    unsigned rlnkcnt;
    ipcarg_t rc;
    int phone;
    aid_t msg;
    ipc_call_t answer;
   
    /* Resolve the path to the mountpoint. */
    fibril_rwlock_write_lock(&namespace_rwlock);
    if (rootfs.fs_handle) {
        /* We already have the root FS. */
        if (str_cmp(mp, "/") == 0) {
            /* Trying to mount root FS over root FS */
            fibril_rwlock_write_unlock(&namespace_rwlock);
            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. */
            fibril_rwlock_write_unlock(&namespace_rwlock);
            ipc_answer_0(rid, rc);
            return;
        }
       
        mp_node = vfs_node_get(&mp_res);
        if (!mp_node) {
            fibril_rwlock_write_unlock(&namespace_rwlock);
            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.
         */
    } else {
        /* We still don't have the root file system mounted. */
        if (str_cmp(mp, "/") == 0) {
            /*
             * 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);
                fibril_rwlock_write_unlock(&namespace_rwlock);
                ipc_answer_0(rid, rc);
                return;
            }
            async_wait_for(msg, &rc);
            vfs_release_phone(phone);
           
            if (rc != EOK) {
                fibril_rwlock_write_unlock(&namespace_rwlock);
                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;
           
            /* Add reference to the mounted root. */
            mr_node = vfs_node_get(&mr_res);
            assert(mr_node);
           
            fibril_rwlock_write_unlock(&namespace_rwlock);
            ipc_answer_0(rid, rc);
            return;
        } else {
            /*
             * We can't resolve this without the root filesystem
             * being mounted first.
             */
            fibril_rwlock_write_unlock(&namespace_rwlock);
            ipc_answer_0(rid, ENOENT);
            return;
        }
    }
   
    /*
     * At this point, we have all necessary pieces: file system and device
     * handles, and we know the mount point VFS node.
     */
   
    int mountee_phone = vfs_grab_phone(fs_handle);
    assert(mountee_phone >= 0);
 
    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 connection */
    rc = async_req_1_0(phone, IPC_M_CONNECTION_CLONE, mountee_phone);
    if (rc != EOK) {
        async_wait_for(msg, NULL);
        vfs_release_phone(mountee_phone);
        vfs_release_phone(phone);
        /* Mount failed, drop reference to mp_node. */
        if (mp_node)
            vfs_node_put(mp_node);
        ipc_answer_0(rid, rc);
        fibril_rwlock_write_unlock(&namespace_rwlock);
        return;
    }
 
    vfs_release_phone(mountee_phone);
   
    /* 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);
        fibril_rwlock_write_unlock(&namespace_rwlock);
        ipc_answer_0(rid, rc);
        return;
    }
    async_wait_for(msg, &rc);
    vfs_release_phone(phone);
   
    if (rc == EOK) {
        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;
   
        /* Add reference to the mounted root. */
        mr_node = vfs_node_get(&mr_res);
        assert(mr_node);
    } else {
        /* Mount failed, drop reference to mp_node. */
        if (mp_node)
            vfs_node_put(mp_node);
    }
 
    ipc_answer_0(rid, rc);
    fibril_rwlock_write_unlock(&namespace_rwlock);
}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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.
     */
    fibril_mutex_lock(&fs_head_lock);
    fs_handle_t fs_handle;
recheck:
    fs_handle = fs_name_to_handle(fs_name, false);
    if (!fs_handle) {
        if (flags & IPC_FLAG_BLOCKING) {
 
 
 
 
 
            fibril_condvar_wait(&fs_head_cv, &fs_head_lock);
 
 
            goto recheck;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
        }
       
        fibril_mutex_unlock(&fs_head_lock);
        ipc_answer_0(callid, ENOENT);
        ipc_answer_0(rid, ENOENT);
        free(mp);
        free(fs_name);
        free(opts);
        return;
    }
    fibril_mutex_unlock(&fs_head_lock);
   
    /* 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. Make sure that the user does not pass L_OPEN.
     */
    if (((lflag & (L_FILE | L_DIRECTORY)) == 0) ||
        ((lflag & (L_FILE | L_DIRECTORY)) == (L_FILE | L_DIRECTORY)) ||
        ((lflag & L_OPEN) != 0)) {
        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)
        fibril_rwlock_write_lock(&namespace_rwlock);
    else
        fibril_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 | L_OPEN, &lr, NULL);
    if (rc != EOK) {
        if (lflag & L_CREATE)
            fibril_rwlock_write_unlock(&namespace_rwlock);
        else
            fibril_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)
        fibril_rwlock_write_unlock(&namespace_rwlock);
    else
        fibril_rwlock_read_unlock(&namespace_rwlock);
   
    /* Truncate the file if requested and if necessary. */
    if (oflag & O_TRUNC) {
        fibril_rwlock_write_lock(&node->contents_rwlock);
        if (node->size) {
            rc = vfs_truncate_internal(node->fs_handle,
                node->dev_handle, node->index, 0);
            if (rc) {
                fibril_rwlock_write_unlock(&node->contents_rwlock);
                vfs_node_put(node);
                ipc_answer_0(rid, rc);
                return;
            }
            node->size = 0;
        }
        fibril_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_open_node(ipc_callid_t rid, ipc_call_t *request)
{
    // FIXME: check for sanity of the supplied fs, dev and index
   
    if (!vfs_files_init()) {
        ipc_answer_0(rid, ENOMEM);
        return;
    }
   
    /*
     * The interface is open_node(fs, dev, index, oflag).
     */
    vfs_lookup_res_t lr;
   
    lr.triplet.fs_handle = IPC_GET_ARG1(*request);
    lr.triplet.dev_handle = IPC_GET_ARG2(*request);
    lr.triplet.index = IPC_GET_ARG3(*request);
    int oflag = IPC_GET_ARG4(*request);
   
    fibril_rwlock_read_lock(&namespace_rwlock);
   
    int rc = vfs_open_node_internal(&lr);
    if (rc != EOK) {
        fibril_rwlock_read_unlock(&namespace_rwlock);
        ipc_answer_0(rid, rc);
        return;
    }
   
    vfs_node_t *node = vfs_node_get(&lr);
    fibril_rwlock_read_unlock(&namespace_rwlock);
   
    /* Truncate the file if requested and if necessary. */
    if (oflag & O_TRUNC) {
        fibril_rwlock_write_lock(&node->contents_rwlock);
        if (node->size) {
            rc = vfs_truncate_internal(node->fs_handle,
                node->dev_handle, node->index, 0);
            if (rc) {
                fibril_rwlock_write_unlock(&node->contents_rwlock);
                vfs_node_put(node);
                ipc_answer_0(rid, rc);
                return;
            }
            node->size = 0;
        }
        fibril_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_node(ipc_callid_t rid, ipc_call_t *request)
{
    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;
    }
   
    ipc_answer_3(rid, EOK, file->node->fs_handle, file->node->dev_handle,
        file->node->index);
}
 
void vfs_device(ipc_callid_t rid, ipc_call_t *request)
{
    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;
    }
   
    /*
     * Lock the open file structure so that no other thread can manipulate
     * the same open file at a time.
     */
    fibril_mutex_lock(&file->lock);
    int fs_phone = vfs_grab_phone(file->node->fs_handle);
   
    /* Make a VFS_DEVICE request at the destination FS server. */
    aid_t msg;
    ipc_call_t answer;
    msg = async_send_2(fs_phone, IPC_GET_METHOD(*request),
        file->node->dev_handle, file->node->index, &answer);
 
    /* Wait for reply from the FS server. */
    ipcarg_t rc;
    async_wait_for(msg, &rc);
 
    vfs_release_phone(fs_phone);
    fibril_mutex_unlock(&file->lock);
   
    ipc_answer_1(rid, EOK, IPC_GET_ARG1(answer));
}
 
void vfs_sync(ipc_callid_t rid, ipc_call_t *request)
{
    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;
    }
   
    /*
     * Lock the open file structure so that no other thread can manipulate
     * the same open file at a time.
     */
    fibril_mutex_lock(&file->lock);
    int fs_phone = vfs_grab_phone(file->node->fs_handle);
   
    /* Make a VFS_SYMC request at the destination FS server. */
    aid_t msg;
    ipc_call_t answer;
    msg = async_send_2(fs_phone, IPC_GET_METHOD(*request),
        file->node->dev_handle, file->node->index, &answer);
 
    /* Wait for reply from the FS server. */
    ipcarg_t rc;
    async_wait_for(msg, &rc);
   
    vfs_release_phone(fs_phone);
    fibril_mutex_unlock(&file->lock);
   
    ipc_answer_0(rid, rc);
}
 
void vfs_close(ipc_callid_t rid, ipc_call_t *request)
{
    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;
    }
   
    /*
     * Lock the open file structure so that no other thread can manipulate
     * the same open file at a time.
     */
    fibril_mutex_lock(&file->lock);
    int fs_phone = vfs_grab_phone(file->node->fs_handle);
   
    /* Make a VFS_CLOSE request at the destination FS server. */
    aid_t msg;
    ipc_call_t answer;
    msg = async_send_2(fs_phone, IPC_GET_METHOD(*request),
        file->node->dev_handle, file->node->index, &answer);
 
    /* Wait for reply from the FS server. */
    ipcarg_t rc;
    async_wait_for(msg, &rc);
 
    vfs_release_phone(fs_phone);
    fibril_mutex_unlock(&file->lock);
   
    int retval = IPC_GET_ARG1(answer);
    if (retval != EOK)
        ipc_answer_0(rid, retval);
   
    retval = vfs_fd_free(fd);
    ipc_answer_0(rid, retval);
}
 
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.
     */
    fibril_mutex_lock(&file->lock);
 
    /*
     * Lock the file's node so that no other client can read/write to it at
     * the same time.
     */
    if (read)
        fibril_rwlock_read_lock(&file->node->contents_rwlock);
    else
        fibril_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);
        fibril_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);
 
    /* Wait for reply from the FS server. */
    ipcarg_t rc;
    async_wait_for(msg, &rc);
   
    vfs_release_phone(fs_phone);
   
    size_t bytes = IPC_GET_ARG1(answer);
 
    if (file->node->type == VFS_NODE_DIRECTORY)
        fibril_rwlock_read_unlock(&namespace_rwlock);
   
    /* Unlock the VFS node. */
    if (read)
        fibril_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);
        fibril_rwlock_write_unlock(&file->node->contents_rwlock);
    }
   
    /* Update the position pointer and unlock the open file. */
    if (rc == EOK)
        file->pos += bytes;
    fibril_mutex_unlock(&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;
    fibril_mutex_lock(&file->lock);
    if (whence == SEEK_SET) {
        file->pos = off;
        fibril_mutex_unlock(&file->lock);
        ipc_answer_1(rid, EOK, off);
        return;
    }
    if (whence == SEEK_CUR) {
        if (file->pos + off < file->pos) {
            fibril_mutex_unlock(&file->lock);
            ipc_answer_0(rid, EOVERFLOW);
            return;
        }
        file->pos += off;
        newpos = file->pos;
        fibril_mutex_unlock(&file->lock);
        ipc_answer_1(rid, EOK, newpos);
        return;
    }
    if (whence == SEEK_END) {
        fibril_rwlock_read_lock(&file->node->contents_rwlock);
        size_t size = file->node->size;
        fibril_rwlock_read_unlock(&file->node->contents_rwlock);
        if (size + off < size) {
            fibril_mutex_unlock(&file->lock);
            ipc_answer_0(rid, EOVERFLOW);
            return;
        }
        newpos = size + off;
        fibril_mutex_unlock(&file->lock);
        ipc_answer_1(rid, EOK, newpos);
        return;
    }
    fibril_mutex_unlock(&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;
    }
    fibril_mutex_lock(&file->lock);
 
    fibril_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;
    fibril_rwlock_write_unlock(&file->node->contents_rwlock);
 
    fibril_mutex_unlock(&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';
   
    fibril_rwlock_write_lock(&namespace_rwlock);
    int lflag = L_DIRECTORY | L_CREATE | L_EXCLUSIVE;
    rc = vfs_lookup_internal(path, lflag, NULL, NULL);
    fibril_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';
   
    fibril_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) {
        fibril_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);
    fibril_mutex_lock(&nodes_mutex);
    node->lnkcnt--;
    fibril_mutex_unlock(&nodes_mutex);
    fibril_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;
    fibril_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) {
        fibril_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) {
        fibril_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) {
        fibril_rwlock_write_unlock(&namespace_rwlock);
        ipc_answer_0(rid, rc);
        free(old);
        free(new);
        return;
    }
    char *lastsl = str_rchr(parentc + 1, '/');
    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) {
        fibril_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)) {
        fibril_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) {
            fibril_rwlock_write_unlock(&namespace_rwlock);
            ipc_answer_0(rid, ENOMEM);
            free(old);
            free(new);
            return;
        }
        fibril_mutex_lock(&nodes_mutex);
        new_node->lnkcnt--;
        fibril_mutex_unlock(&nodes_mutex);
        break;
    default:
        fibril_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) {
        fibril_rwlock_write_unlock(&namespace_rwlock);
        if (new_node)
            vfs_node_put(new_node);
        ipc_answer_0(rid, rc);
        free(old);
        free(new);
        return;
    }
    fibril_mutex_lock(&nodes_mutex);
    old_node->lnkcnt++;
    fibril_mutex_unlock(&nodes_mutex);
    /* Destroy the link for the old name. */
    rc = vfs_lookup_internal(oldc, L_UNLINK, NULL, NULL);
    if (rc != EOK) {
        fibril_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;
    }
    fibril_mutex_lock(&nodes_mutex);
    old_node->lnkcnt--;
    fibril_mutex_unlock(&nodes_mutex);
    fibril_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 4555	Rev 4566
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 <fibril_sync.h>	46	#include <fibril_sync.h>
47	#include <adt/list.h>	47	#include <adt/list.h>
48	#include <unistd.h>	48	#include <unistd.h>
49	#include <ctype.h>	49	#include <ctype.h>
50	#include <fcntl.h>	50	#include <fcntl.h>
51	#include <assert.h>	51	#include <assert.h>
52	#include <vfs/canonify.h>	52	#include <vfs/canonify.h>
53		53
54	/* Forward declarations of static functions. */	54	/* Forward declarations of static functions. */
55	static int vfs_truncate_internal(fs_handle_t, dev_handle_t, fs_index_t, size_t);	55	static int vfs_truncate_internal(fs_handle_t, dev_handle_t, fs_index_t, size_t);
56		56
57	/** Pending mount structure. */	-
58	typedef struct {	-
59	link_t link;	-
60	char fs_name; /< File system name /	-
61	char mp; /< Mount point /	-
62	char opts; /< Mount options. /	-
63	ipc_callid_t callid; /*< Call ID waiting for the mount /	-
64	ipc_callid_t rid; /*< Request ID /	-
65	dev_handle_t dev_handle; /*< Device handle /	-
66	} pending_req_t;	-
67		-
68	FIBRIL_CONDVAR_INITIALIZE(pending_cv);	-
69	bool pending_new_fs = false; /*< True if a new file system was mounted. /	-
70	LIST_INITIALIZE(pending_req);	-
71		-
72	/**	57	/**
73	* This rwlock prevents the race between a triplet-to-VFS-node resolution and a	58	* This rwlock prevents the race between a triplet-to-VFS-node resolution and a
74	* concurrent VFS operation which modifies the file system namespace.	59	* concurrent VFS operation which modifies the file system namespace.
75	*/	60	*/
76	FIBRIL_RWLOCK_INITIALIZE(namespace_rwlock);	61	FIBRIL_RWLOCK_INITIALIZE(namespace_rwlock);
77		62
78	vfs_pair_t rootfs = {	63	vfs_pair_t rootfs = {
79	.fs_handle = 0,	64	.fs_handle = 0,
80	.dev_handle = 0	65	.dev_handle = 0
81	};	66	};
82		67
83	static void vfs_mount_internal(ipc_callid_t rid, dev_handle_t dev_handle,	68	static void vfs_mount_internal(ipc_callid_t rid, dev_handle_t dev_handle,
84	fs_handle_t fs_handle, char mp, char opts)	69	fs_handle_t fs_handle, char mp, char opts)
85	{	70	{
86	vfs_lookup_res_t mp_res;	71	vfs_lookup_res_t mp_res;
87	vfs_lookup_res_t mr_res;	72	vfs_lookup_res_t mr_res;
88	vfs_node_t *mp_node = NULL;	73	vfs_node_t *mp_node = NULL;
89	vfs_node_t *mr_node;	74	vfs_node_t *mr_node;
90	fs_index_t rindex;	75	fs_index_t rindex;
91	size_t rsize;	76	size_t rsize;
92	unsigned rlnkcnt;	77	unsigned rlnkcnt;
93	ipcarg_t rc;	78	ipcarg_t rc;
94	int phone;	79	int phone;
95	aid_t msg;	80	aid_t msg;
96	ipc_call_t answer;	81	ipc_call_t answer;
97		82
98	/* Resolve the path to the mountpoint. */	83	/* Resolve the path to the mountpoint. */
99	fibril_rwlock_write_lock(&namespace_rwlock);	84	fibril_rwlock_write_lock(&namespace_rwlock);
100	if (rootfs.fs_handle) {	85	if (rootfs.fs_handle) {
101	/* We already have the root FS. */	86	/* We already have the root FS. */
102	if (str_cmp(mp, "/") == 0) {	87	if (str_cmp(mp, "/") == 0) {
103	/* Trying to mount root FS over root FS */	88	/* Trying to mount root FS over root FS */
104	fibril_rwlock_write_unlock(&namespace_rwlock);	89	fibril_rwlock_write_unlock(&namespace_rwlock);
105	ipc_answer_0(rid, EBUSY);	90	ipc_answer_0(rid, EBUSY);
106	return;	91	return;
107	}	92	}
108		93
109	rc = vfs_lookup_internal(mp, L_DIRECTORY, &mp_res, NULL);	94	rc = vfs_lookup_internal(mp, L_DIRECTORY, &mp_res, NULL);
110	if (rc != EOK) {	95	if (rc != EOK) {
111	/* The lookup failed for some reason. */	96	/* The lookup failed for some reason. */
112	fibril_rwlock_write_unlock(&namespace_rwlock);	97	fibril_rwlock_write_unlock(&namespace_rwlock);
113	ipc_answer_0(rid, rc);	98	ipc_answer_0(rid, rc);
114	return;	99	return;
115	}	100	}
116		101
117	mp_node = vfs_node_get(&mp_res);	102	mp_node = vfs_node_get(&mp_res);
118	if (!mp_node) {	103	if (!mp_node) {
119	fibril_rwlock_write_unlock(&namespace_rwlock);	104	fibril_rwlock_write_unlock(&namespace_rwlock);
120	ipc_answer_0(rid, ENOMEM);	105	ipc_answer_0(rid, ENOMEM);
121	return;	106	return;
122	}	107	}
123		108
124	/*	109	/*
125	* Now we hold a reference to mp_node.	110	* Now we hold a reference to mp_node.
126	* It will be dropped upon the corresponding VFS_UNMOUNT.	111	* It will be dropped upon the corresponding VFS_UNMOUNT.
127	* This prevents the mount point from being deleted.	112	* This prevents the mount point from being deleted.
128	*/	113	*/
129	} else {	114	} else {
130	/* We still don't have the root file system mounted. */	115	/* We still don't have the root file system mounted. */
131	if (str_cmp(mp, "/") == 0) {	116	if (str_cmp(mp, "/") == 0) {
132	/*	117	/*
133	* For this simple, but important case,	118	* For this simple, but important case,
134	* we are almost done.	119	* we are almost done.
135	*/	120	*/
136		121
137	/* Tell the mountee that it is being mounted. */	122	/* Tell the mountee that it is being mounted. */
138	phone = vfs_grab_phone(fs_handle);	123	phone = vfs_grab_phone(fs_handle);
139	msg = async_send_1(phone, VFS_MOUNTED,	124	msg = async_send_1(phone, VFS_MOUNTED,
140	(ipcarg_t) dev_handle, &answer);	125	(ipcarg_t) dev_handle, &answer);
141	/* send the mount options */	126	/* send the mount options */
142	rc = ipc_data_write_start(phone, (void *)opts,	127	rc = ipc_data_write_start(phone, (void *)opts,
143	str_size(opts));	128	str_size(opts));
144	if (rc != EOK) {	129	if (rc != EOK) {
145	async_wait_for(msg, NULL);	130	async_wait_for(msg, NULL);
146	vfs_release_phone(phone);	131	vfs_release_phone(phone);
147	fibril_rwlock_write_unlock(&namespace_rwlock);	132	fibril_rwlock_write_unlock(&namespace_rwlock);
148	ipc_answer_0(rid, rc);	133	ipc_answer_0(rid, rc);
149	return;	134	return;
150	}	135	}
151	async_wait_for(msg, &rc);	136	async_wait_for(msg, &rc);
152	vfs_release_phone(phone);	137	vfs_release_phone(phone);
153		138
154	if (rc != EOK) {	139	if (rc != EOK) {
155	fibril_rwlock_write_unlock(&namespace_rwlock);	140	fibril_rwlock_write_unlock(&namespace_rwlock);
156	ipc_answer_0(rid, rc);	141	ipc_answer_0(rid, rc);
157	return;	142	return;
158	}	143	}
159		144
160	rindex = (fs_index_t) IPC_GET_ARG1(answer);	145	rindex = (fs_index_t) IPC_GET_ARG1(answer);
161	rsize = (size_t) IPC_GET_ARG2(answer);	146	rsize = (size_t) IPC_GET_ARG2(answer);
162	rlnkcnt = (unsigned) IPC_GET_ARG3(answer);	147	rlnkcnt = (unsigned) IPC_GET_ARG3(answer);
163		148
164	mr_res.triplet.fs_handle = fs_handle;	149	mr_res.triplet.fs_handle = fs_handle;
165	mr_res.triplet.dev_handle = dev_handle;	150	mr_res.triplet.dev_handle = dev_handle;
166	mr_res.triplet.index = rindex;	151	mr_res.triplet.index = rindex;
167	mr_res.size = rsize;	152	mr_res.size = rsize;
168	mr_res.lnkcnt = rlnkcnt;	153	mr_res.lnkcnt = rlnkcnt;
169	mr_res.type = VFS_NODE_DIRECTORY;	154	mr_res.type = VFS_NODE_DIRECTORY;
170		155
171	rootfs.fs_handle = fs_handle;	156	rootfs.fs_handle = fs_handle;
172	rootfs.dev_handle = dev_handle;	157	rootfs.dev_handle = dev_handle;
173		158
174	/* Add reference to the mounted root. */	159	/* Add reference to the mounted root. */
175	mr_node = vfs_node_get(&mr_res);	160	mr_node = vfs_node_get(&mr_res);
176	assert(mr_node);	161	assert(mr_node);
177		162
178	fibril_rwlock_write_unlock(&namespace_rwlock);	163	fibril_rwlock_write_unlock(&namespace_rwlock);
179	ipc_answer_0(rid, rc);	164	ipc_answer_0(rid, rc);
180	return;	165	return;
181	} else {	166	} else {
182	/*	167	/*
183	* We can't resolve this without the root filesystem	168	* We can't resolve this without the root filesystem
184	* being mounted first.	169	* being mounted first.
185	*/	170	*/
186	fibril_rwlock_write_unlock(&namespace_rwlock);	171	fibril_rwlock_write_unlock(&namespace_rwlock);
187	ipc_answer_0(rid, ENOENT);	172	ipc_answer_0(rid, ENOENT);
188	return;	173	return;
189	}	174	}
190	}	175	}
191		176
192	/*	177	/*
193	* At this point, we have all necessary pieces: file system and device	178	* At this point, we have all necessary pieces: file system and device
194	* handles, and we know the mount point VFS node.	179	* handles, and we know the mount point VFS node.
195	*/	180	*/
196		181
197	int mountee_phone = vfs_grab_phone(fs_handle);	182	int mountee_phone = vfs_grab_phone(fs_handle);
198	assert(mountee_phone >= 0);	183	assert(mountee_phone >= 0);
199		184
200	phone = vfs_grab_phone(mp_res.triplet.fs_handle);	185	phone = vfs_grab_phone(mp_res.triplet.fs_handle);
201	msg = async_send_4(phone, VFS_MOUNT,	186	msg = async_send_4(phone, VFS_MOUNT,
202	(ipcarg_t) mp_res.triplet.dev_handle,	187	(ipcarg_t) mp_res.triplet.dev_handle,
203	(ipcarg_t) mp_res.triplet.index,	188	(ipcarg_t) mp_res.triplet.index,
204	(ipcarg_t) fs_handle,	189	(ipcarg_t) fs_handle,
205	(ipcarg_t) dev_handle, &answer);	190	(ipcarg_t) dev_handle, &answer);
206		191
207	/* send connection */	192	/* send connection */
208	rc = async_req_1_0(phone, IPC_M_CONNECTION_CLONE, mountee_phone);	193	rc = async_req_1_0(phone, IPC_M_CONNECTION_CLONE, mountee_phone);
209	if (rc != EOK) {	194	if (rc != EOK) {
210	async_wait_for(msg, NULL);	195	async_wait_for(msg, NULL);
211	vfs_release_phone(mountee_phone);	196	vfs_release_phone(mountee_phone);
212	vfs_release_phone(phone);	197	vfs_release_phone(phone);
213	/* Mount failed, drop reference to mp_node. */	198	/* Mount failed, drop reference to mp_node. */
214	if (mp_node)	199	if (mp_node)
215	vfs_node_put(mp_node);	200	vfs_node_put(mp_node);
216	ipc_answer_0(rid, rc);	201	ipc_answer_0(rid, rc);
217	fibril_rwlock_write_unlock(&namespace_rwlock);	202	fibril_rwlock_write_unlock(&namespace_rwlock);
218	return;	203	return;
219	}	204	}
220		205
221	vfs_release_phone(mountee_phone);	206	vfs_release_phone(mountee_phone);
222		207
223	/* send the mount options */	208	/* send the mount options */
224	rc = ipc_data_write_start(phone, (void *)opts, str_size(opts));	209	rc = ipc_data_write_start(phone, (void *)opts, str_size(opts));
225	if (rc != EOK) {	210	if (rc != EOK) {
226	async_wait_for(msg, NULL);	211	async_wait_for(msg, NULL);
227	vfs_release_phone(phone);	212	vfs_release_phone(phone);
228	/* Mount failed, drop reference to mp_node. */	213	/* Mount failed, drop reference to mp_node. */
229	if (mp_node)	214	if (mp_node)
230	vfs_node_put(mp_node);	215	vfs_node_put(mp_node);
231	fibril_rwlock_write_unlock(&namespace_rwlock);	216	fibril_rwlock_write_unlock(&namespace_rwlock);
232	ipc_answer_0(rid, rc);	217	ipc_answer_0(rid, rc);
233	return;	218	return;
234	}	219	}
235	async_wait_for(msg, &rc);	220	async_wait_for(msg, &rc);
236	vfs_release_phone(phone);	221	vfs_release_phone(phone);
237		222
238	if (rc == EOK) {	223	if (rc == EOK) {
239	rindex = (fs_index_t) IPC_GET_ARG1(answer);	224	rindex = (fs_index_t) IPC_GET_ARG1(answer);
240	rsize = (size_t) IPC_GET_ARG2(answer);	225	rsize = (size_t) IPC_GET_ARG2(answer);
241	rlnkcnt = (unsigned) IPC_GET_ARG3(answer);	226	rlnkcnt = (unsigned) IPC_GET_ARG3(answer);
242		227
243	mr_res.triplet.fs_handle = fs_handle;	228	mr_res.triplet.fs_handle = fs_handle;
244	mr_res.triplet.dev_handle = dev_handle;	229	mr_res.triplet.dev_handle = dev_handle;
245	mr_res.triplet.index = rindex;	230	mr_res.triplet.index = rindex;
246	mr_res.size = rsize;	231	mr_res.size = rsize;
247	mr_res.lnkcnt = rlnkcnt;	232	mr_res.lnkcnt = rlnkcnt;
248	mr_res.type = VFS_NODE_DIRECTORY;	233	mr_res.type = VFS_NODE_DIRECTORY;
249		234
250	/* Add reference to the mounted root. */	235	/* Add reference to the mounted root. */
251	mr_node = vfs_node_get(&mr_res);	236	mr_node = vfs_node_get(&mr_res);
252	assert(mr_node);	237	assert(mr_node);
253	} else {	238	} else {
254	/* Mount failed, drop reference to mp_node. */	239	/* Mount failed, drop reference to mp_node. */
255	if (mp_node)	240	if (mp_node)
256	vfs_node_put(mp_node);	241	vfs_node_put(mp_node);
257	}	242	}
258		243
259	ipc_answer_0(rid, rc);	244	ipc_answer_0(rid, rc);
260	fibril_rwlock_write_unlock(&namespace_rwlock);	245	fibril_rwlock_write_unlock(&namespace_rwlock);
261	}	246	}
262		247
263	/** Process pending mount requests */	-
264	void vfs_process_pending_mount(void)	-
265	{	-
266	link_t *cur;	-
267		-
268	while (true) {	-
269	fibril_mutex_lock(&fs_head_lock);	-
270	while (!pending_new_fs)	-
271	fibril_condvar_wait(&pending_cv, &fs_head_lock);	-
272	rescan:	-
273	for (cur = pending_req.next; cur != &pending_req;	-
274	cur = cur->next) {	-
275	pending_req_t *pr = list_get_instance(cur,	-
276	pending_req_t, link);	-
277	fs_handle_t fs_handle = fs_name_to_handle(pr->fs_name,	-
278	false);	-
279	if (!fs_handle)	-
280	continue;	-
281		-
282	/* Acknowledge that we know fs_name. */	-
283	ipc_answer_0(pr->callid, EOK);	-
284		-
285	list_remove(cur);	-
286	fibril_mutex_unlock(&fs_head_lock);	-
287		-
288	/* Do the mount */	-
289	vfs_mount_internal(pr->rid, pr->dev_handle, fs_handle,	-
290	pr->mp, pr->opts);	-
291		-
292	free(pr->fs_name);	-
293	free(pr->mp);	-
294	free(pr->opts);	-
295	free(pr);	-
296		-
297	fibril_mutex_lock(&fs_head_lock);	-
298	goto rescan;	-
299	}	-
300	pending_new_fs = false;	-
301	fibril_mutex_unlock(&fs_head_lock);	-
302	}	-
303	}	-
304		-
305	void vfs_mount(ipc_callid_t rid, ipc_call_t *request)	248	void vfs_mount(ipc_callid_t rid, ipc_call_t *request)
306	{	249	{
307	/*	250	/*
308	* We expect the library to do the device-name to device-handle	251	* We expect the library to do the device-name to device-handle
309	* translation for us, thus the device handle will arrive as ARG1	252	* translation for us, thus the device handle will arrive as ARG1
310	* in the request.	253	* in the request.
311	*/	254	*/
312	dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request);	255	dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request);
313		256
314	/*	257	/*
315	* Mount flags are passed as ARG2.	258	* Mount flags are passed as ARG2.
316	*/	259	*/
317	unsigned int flags = (unsigned int) IPC_GET_ARG2(*request);	260	unsigned int flags = (unsigned int) IPC_GET_ARG2(*request);
318		261
319	/*	262	/*
320	* For now, don't make use of ARG3, but it can be used to	263	* For now, don't make use of ARG3, but it can be used to
321	* carry mount options in the future.	264	* carry mount options in the future.
322	*/	265	*/
323		266
324	/* We want the client to send us the mount point. */	267	/* We want the client to send us the mount point. */
325	ipc_callid_t callid;	268	ipc_callid_t callid;
326	size_t size;	269	size_t size;
327	if (!ipc_data_write_receive(&callid, &size)) {	270	if (!ipc_data_write_receive(&callid, &size)) {
328	ipc_answer_0(callid, EINVAL);	271	ipc_answer_0(callid, EINVAL);
329	ipc_answer_0(rid, EINVAL);	272	ipc_answer_0(rid, EINVAL);
330	return;	273	return;
331	}	274	}
332		275
333	/* Check whether size is reasonable wrt. the mount point. */	276	/* Check whether size is reasonable wrt. the mount point. */
334	if ((size < 1) \|\| (size > MAX_PATH_LEN)) {	277	if ((size < 1) \|\| (size > MAX_PATH_LEN)) {
335	ipc_answer_0(callid, EINVAL);	278	ipc_answer_0(callid, EINVAL);
336	ipc_answer_0(rid, EINVAL);	279	ipc_answer_0(rid, EINVAL);
337	return;	280	return;
338	}	281	}
339		282
340	/* Allocate buffer for the mount point data being received. */	283	/* Allocate buffer for the mount point data being received. */
341	char *mp = malloc(size + 1);	284	char *mp = malloc(size + 1);
342	if (!mp) {	285	if (!mp) {
343	ipc_answer_0(callid, ENOMEM);	286	ipc_answer_0(callid, ENOMEM);
344	ipc_answer_0(rid, ENOMEM);	287	ipc_answer_0(rid, ENOMEM);
345	return;	288	return;
346	}	289	}
347		290
348	/* Deliver the mount point. */	291	/* Deliver the mount point. */
349	ipcarg_t retval = ipc_data_write_finalize(callid, mp, size);	292	ipcarg_t retval = ipc_data_write_finalize(callid, mp, size);
350	if (retval != EOK) {	293	if (retval != EOK) {
351	ipc_answer_0(rid, retval);	294	ipc_answer_0(rid, retval);
352	free(mp);	295	free(mp);
353	return;	296	return;
354	}	297	}
355	mp[size] = '\0';	298	mp[size] = '\0';
356		299
357	/* Now we expect to receive the mount options. */	300	/* Now we expect to receive the mount options. */
358	if (!ipc_data_write_receive(&callid, &size)) {	301	if (!ipc_data_write_receive(&callid, &size)) {
359	ipc_answer_0(callid, EINVAL);	302	ipc_answer_0(callid, EINVAL);
360	ipc_answer_0(rid, EINVAL);	303	ipc_answer_0(rid, EINVAL);
361	free(mp);	304	free(mp);
362	return;	305	return;
363	}	306	}
364		307
365	/* Check the offered options size. */	308	/* Check the offered options size. */
366	if (size < 0 \|\| size > MAX_MNTOPTS_LEN) {	309	if (size < 0 \|\| size > MAX_MNTOPTS_LEN) {
367	ipc_answer_0(callid, EINVAL);	310	ipc_answer_0(callid, EINVAL);
368	ipc_answer_0(rid, EINVAL);	311	ipc_answer_0(rid, EINVAL);
369	free(mp);	312	free(mp);
370	return;	313	return;
371	}	314	}
372		315
373	/* Allocate buffer for the mount options. */	316	/* Allocate buffer for the mount options. */
374	char opts = (char ) malloc(size + 1);	317	char opts = (char ) malloc(size + 1);
375	if (!opts) {	318	if (!opts) {
376	ipc_answer_0(callid, ENOMEM);	319	ipc_answer_0(callid, ENOMEM);
377	ipc_answer_0(rid, ENOMEM);	320	ipc_answer_0(rid, ENOMEM);
378	free(mp);	321	free(mp);
379	return;	322	return;
380	}	323	}
381		324
382	/* Deliver the mount options. */	325	/* Deliver the mount options. */
383	retval = ipc_data_write_finalize(callid, opts, size);	326	retval = ipc_data_write_finalize(callid, opts, size);
384	if (retval != EOK) {	327	if (retval != EOK) {
385	ipc_answer_0(rid, retval);	328	ipc_answer_0(rid, retval);
386	free(mp);	329	free(mp);
387	free(opts);	330	free(opts);
388	return;	331	return;
389	}	332	}
390	opts[size] = '\0';	333	opts[size] = '\0';
391		334
392	/*	335	/*
393	* Now, we expect the client to send us data with the name of the file	336	* Now, we expect the client to send us data with the name of the file
394	* system.	337	* system.
395	*/	338	*/
396	if (!ipc_data_write_receive(&callid, &size)) {	339	if (!ipc_data_write_receive(&callid, &size)) {
397	ipc_answer_0(callid, EINVAL);	340	ipc_answer_0(callid, EINVAL);
398	ipc_answer_0(rid, EINVAL);	341	ipc_answer_0(rid, EINVAL);
399	free(mp);	342	free(mp);
400	free(opts);	343	free(opts);
401	return;	344	return;
402	}	345	}
403		346
404	/*	347	/*
405	* Don't receive more than is necessary for storing a full file system	348	* Don't receive more than is necessary for storing a full file system
406	* name.	349	* name.
407	*/	350	*/
408	if ((size < 1) \|\| (size > FS_NAME_MAXLEN)) {	351	if ((size < 1) \|\| (size > FS_NAME_MAXLEN)) {
409	ipc_answer_0(callid, EINVAL);	352	ipc_answer_0(callid, EINVAL);
410	ipc_answer_0(rid, EINVAL);	353	ipc_answer_0(rid, EINVAL);
411	free(mp);	354	free(mp);
412	free(opts);	355	free(opts);
413	return;	356	return;
414	}	357	}
415		358
416	/*	359	/*
417	* Allocate buffer for file system name.	360	* Allocate buffer for file system name.
418	*/	361	*/
419	char fs_name = (char ) malloc(size + 1);	362	char fs_name = (char ) malloc(size + 1);
420	if (fs_name == NULL) {	363	if (fs_name == NULL) {
421	ipc_answer_0(callid, ENOMEM);	364	ipc_answer_0(callid, ENOMEM);
422	ipc_answer_0(rid, ENOMEM);	365	ipc_answer_0(rid, ENOMEM);
423	free(mp);	366	free(mp);
424	free(opts);	367	free(opts);
425	return;	368	return;
426	}	369	}
427		370
428	/* Deliver the file system name. */	371	/* Deliver the file system name. */
429	retval = ipc_data_write_finalize(callid, fs_name, size);	372	retval = ipc_data_write_finalize(callid, fs_name, size);
430	if (retval != EOK) {	373	if (retval != EOK) {
431	ipc_answer_0(rid, retval);	374	ipc_answer_0(rid, retval);
432	free(mp);	375	free(mp);
433	free(opts);	376	free(opts);
434	free(fs_name);	377	free(fs_name);
435	return;	378	return;
436	}	379	}
437	fs_name[size] = '\0';	380	fs_name[size] = '\0';
438		381
439	/*	382	/*
440	* Wait for IPC_M_PING so that we can return an error if we don't know	383	* Wait for IPC_M_PING so that we can return an error if we don't know
441	* fs_name.	384	* fs_name.
442	*/	385	*/
443	ipc_call_t data;	386	ipc_call_t data;
444	callid = async_get_call(&data);	387	callid = async_get_call(&data);
445	if (IPC_GET_METHOD(data) != IPC_M_PING) {	388	if (IPC_GET_METHOD(data) != IPC_M_PING) {
446	ipc_answer_0(callid, ENOTSUP);	389	ipc_answer_0(callid, ENOTSUP);
447	ipc_answer_0(rid, ENOTSUP);	390	ipc_answer_0(rid, ENOTSUP);
448	free(mp);	391	free(mp);
449	free(opts);	392	free(opts);
450	free(fs_name);	393	free(fs_name);
451	return;	394	return;
452	}	395	}
453		396
454	/*	397	/*
455	* Check if we know a file system with the same name as is in fs_name.	398	* Check if we know a file system with the same name as is in fs_name.
456	* This will also give us its file system handle.	399	* This will also give us its file system handle.
457	*/	400	*/
458	fibril_mutex_lock(&fs_head_lock);	401	fibril_mutex_lock(&fs_head_lock);
-		402	fs_handle_t fs_handle;
-		403	recheck:
459	fs_handle_t fs_handle = fs_name_to_handle(fs_name, false);	404	fs_handle = fs_name_to_handle(fs_name, false);
460	if (!fs_handle) {	405	if (!fs_handle) {
461	if (flags & IPC_FLAG_BLOCKING) {	406	if (flags & IPC_FLAG_BLOCKING) {
462	pending_req_t *pr;	-
463		-
464	/* Blocking mount, add to pending list */	-
465	pr = (pending_req_t *) malloc(sizeof(pending_req_t));	-
466	if (!pr) {	-
467	fibril_mutex_unlock(&fs_head_lock);	407	fibril_condvar_wait(&fs_head_cv, &fs_head_lock);
468	ipc_answer_0(callid, ENOMEM);	-
469	ipc_answer_0(rid, ENOMEM);	-
470	free(mp);	408	goto recheck;
471	free(fs_name);	-
472	free(opts);	-
473	return;	-
474	}	-
475		-
476	pr->fs_name = fs_name;	-
477	pr->mp = mp;	-
478	pr->opts = opts;	-
479	pr->callid = callid;	-
480	pr->rid = rid;	-
481	pr->dev_handle = dev_handle;	-
482	link_initialize(&pr->link);	-
483	list_append(&pr->link, &pending_req);	-
484	fibril_mutex_unlock(&fs_head_lock);	-
485	return;	-
486	}	409	}
487		410
488	fibril_mutex_unlock(&fs_head_lock);	411	fibril_mutex_unlock(&fs_head_lock);
489	ipc_answer_0(callid, ENOENT);	412	ipc_answer_0(callid, ENOENT);
490	ipc_answer_0(rid, ENOENT);	413	ipc_answer_0(rid, ENOENT);
491	free(mp);	414	free(mp);
492	free(fs_name);	415	free(fs_name);
493	free(opts);	416	free(opts);
494	return;	417	return;
495	}	418	}
496	fibril_mutex_unlock(&fs_head_lock);	419	fibril_mutex_unlock(&fs_head_lock);
497		420
498	/* Acknowledge that we know fs_name. */	421	/* Acknowledge that we know fs_name. */

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(root)/trunk/uspace/srv/vfs/vfs_ops.c – Rev 4555 → 4566