/trunk/uspace/srv/vfs/vfs.c |
---|
100,6 → 100,8 |
case VFS_READ: |
case VFS_WRITE: |
case VFS_SEEK: |
case VFS_UNLINK: |
case VFS_RENAME: |
default: |
ipc_answer_fast_0(callid, ENOTSUP); |
break; |
/trunk/uspace/srv/vfs/vfs_unlink.c |
---|
0,0 → 1,49 |
/* |
* Copyright (c) 2007 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_unlink.c |
* @brief |
*/ |
#include <atomic.h> |
#include <futex.h> |
/** |
* This futex serializes concurrent VFS_CREATE, VFS_OPEN and VFS_UNLINK |
* operations. |
*/ |
atomic_t unlink_futex = FUTEX_INITIALIZER; |
/** |
* @} |
*/ |
/trunk/uspace/srv/vfs/vfs_open.c |
---|
38,58 → 38,14 |
#include <ipc/ipc.h> |
#include <async.h> |
#include <errno.h> |
#include <stdlib.h> |
#include <string.h> |
#include <bool.h> |
#include <futex.h> |
#include <libadt/list.h> |
#include <sys/types.h> |
#include <stdlib.h> |
#include "vfs.h" |
/** Per-connection futex protecting the files array. */ |
__thread atomic_t files_futex = FUTEX_INITIALIZER; |
/** |
* This is a per-connection table of open files. |
* Our assumption is that each client opens only one connection and therefore |
* there is one table of open files per task. However, this may not be the case |
* and the client can open more connections to VFS. In that case, there will be |
* several tables and several file handle name spaces per task. Besides of this, |
* the functionality will stay unchanged. So unless the client knows what it is |
* doing, it should open one connection to VFS only. |
* |
* Allocation of the open files table is deferred until the client makes the |
* first VFS_OPEN operation. |
*/ |
__thread vfs_file_t *files = NULL; |
/** Initialize the table of open files. */ |
static bool vfs_conn_open_files_init(void) |
{ |
/* |
* Optimized fast path that will never go to sleep unnecessarily. |
* The assumption is that once files is non-zero, it will never be zero |
* again. |
*/ |
if (files) |
return true; |
futex_down(&files_futex); |
if (!files) { |
files = malloc(MAX_OPEN_FILES * sizeof(vfs_file_t)); |
if (!files) { |
futex_up(&files_futex); |
return false; |
} |
memset(files, 0, MAX_OPEN_FILES * sizeof(vfs_file_t)); |
} |
futex_up(&files_futex); |
return true; |
} |
void vfs_open(ipc_callid_t rid, ipc_call_t *request) |
{ |
if (!vfs_conn_open_files_init()) { |
if (!vfs_files_init()) { |
ipc_answer_fast_0(rid, ENOMEM); |
return; |
} |
127,7 → 83,7 |
} |
int rc; |
if (rc = ipc_data_deliver(callid, &call, path, size)) { |
if ((rc = ipc_data_deliver(callid, &call, path, size))) { |
ipc_answer_fast_0(rid, rc); |
free(path); |
return; |
134,11 → 90,19 |
} |
/* |
* 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. |
*/ |
futex_down(&unlink_futex); |
/* |
* The path is now populated and we can call vfs_lookup_internal(). |
*/ |
vfs_triplet_t triplet; |
rc = vfs_lookup_internal(path, size, &triplet, NULL); |
if (rc) { |
futex_up(&unlink_futex); |
ipc_answer_fast_0(rid, rc); |
free(path); |
return; |
150,7 → 114,35 |
free(path); |
vfs_node_t *node = vfs_node_get(&triplet); |
// TODO: not finished |
futex_up(&unlink_futex); |
/* |
* 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_fast_0(rid, fd); |
return; |
} |
vfs_file_t *file = vfs_file_get(fd); |
file->node = node; |
/* |
* 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_fast_1(rid, EOK, fd); |
} |
/** |
/trunk/uspace/srv/vfs/vfs.h |
---|
56,6 → 56,8 |
VFS_READ, |
VFS_WRITE, |
VFS_SEEK, |
VFS_RENAME, |
VFS_UNLINK, |
VFS_LAST, /* keep this the last member of the enum */ |
} vfs_request_t; |
130,7 → 132,8 |
*/ |
typedef struct { |
VFS_TRIPLET; /**< Identity of the node. */ |
atomic_t refcnt; /**< Usage counter. */ |
unsigned refcnt; /**< Usage counter. */ |
link_t nh_link; /**< Node hash-table link. */ |
} vfs_node_t; |
/** |
141,7 → 144,7 |
vfs_node_t *node; |
/** Number of file handles referencing this file. */ |
atomic_t refcnt; |
unsigned refcnt; |
/** Current position in the file. */ |
off_t pos; |
166,6 → 169,8 |
extern uint8_t *plb; /**< Path Lookup Buffer */ |
extern link_t plb_head; /**< List of active PLB entries. */ |
extern atomic_t unlink_futex; /**< VFS_{CREATE|OPEN|UNLINK} serialization. */ |
extern int vfs_grab_phone(int); |
extern void vfs_release_phone(int); |
172,8 → 177,22 |
extern int fs_name_to_handle(char *, bool); |
extern int vfs_lookup_internal(char *, size_t, vfs_triplet_t *, vfs_pair_t *); |
extern vfs_node_t *vfs_node_get(vfs_triplet_t *); |
extern void vfs_node_put(vfs_node_t *); |
extern bool vfs_files_init(void); |
extern vfs_file_t *vfs_file_get(int); |
extern int vfs_fd_alloc(void); |
extern void vfs_fd_free(int); |
extern void vfs_file_addref(vfs_file_t *); |
extern void vfs_file_delref(vfs_file_t *); |
extern void vfs_node_addref(vfs_node_t *); |
extern void vfs_node_delref(vfs_node_t *); |
#define MAX_OPEN_FILES 128 |
extern void vfs_register(ipc_callid_t, ipc_call_t *); |
/trunk/uspace/srv/vfs/vfs_node.c |
---|
37,11 → 37,57 |
#include "vfs.h" |
/** Increment reference count of a VFS node. |
* |
* @param node VFS node that will have its refcnt incremented. |
*/ |
void vfs_node_addref(vfs_node_t *node) |
{ |
/* TODO */ |
} |
/** Decrement reference count of a VFS node. |
* |
* This function handles the case when the reference count drops to zero. |
* |
* @param node VFS node that will have its refcnt decremented. |
*/ |
void vfs_node_delref(vfs_node_t *node) |
{ |
/* TODO */ |
} |
/** Find VFS node. |
* |
* This function will try to lookup the given triplet in the VFS node hash |
* table. In case the triplet is not found there, a new VFS node is created. |
* In any case, the VFS node will have its reference count incremented. Every |
* node returned by this call should be eventually put back by calling |
* vfs_node_put() on it. |
* |
* @param triplet Triplet encoding the identity of the VFS node. |
* |
* @return VFS node corresponding to the given triplet. |
*/ |
vfs_node_t *vfs_node_get(vfs_triplet_t *triplet) |
{ |
return NULL; // TODO: not implemented |
/* TODO */ |
return NULL; |
} |
/** Return VFS node when no longer needed by the caller. |
* |
* This function will remove the reference on the VFS node created by |
* vfs_node_get(). This function can only be called as a closing bracket to the |
* preceding vfs_node_get() call. |
* |
* @param node VFS node being released. |
*/ |
void vfs_node_put(vfs_node_t *node) |
{ |
vfs_node_delref(node); |
} |
/** |
* @} |
*/ |
/trunk/uspace/srv/vfs/Makefile |
---|
43,10 → 43,12 |
SOURCES = \ |
vfs.c \ |
vfs_node.c \ |
vfs_file.c \ |
vfs_register.c \ |
vfs_lookup.c \ |
vfs_mount.c \ |
vfs_open.c |
vfs_open.c \ |
vfs_unlink.c |
OBJECTS := $(addsuffix .o,$(basename $(SOURCES))) |
/trunk/uspace/srv/vfs/vfs_file.c |
---|
0,0 → 1,152 |
/* |
* Copyright (c) 2007 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_file.c |
* @brief Various operations on files have their home in this file. |
*/ |
#include <errno.h> |
#include <stdlib.h> |
#include <string.h> |
#include <assert.h> |
#include <bool.h> |
#include "vfs.h" |
/** |
* This is a per-connection table of open files. |
* Our assumption is that each client opens only one connection and therefore |
* there is one table of open files per task. However, this may not be the case |
* and the client can open more connections to VFS. In that case, there will be |
* several tables and several file handle name spaces per task. Besides of this, |
* the functionality will stay unchanged. So unless the client knows what it is |
* doing, it should open one connection to VFS only. |
* |
* Allocation of the open files table is deferred until the client makes the |
* first VFS_OPEN operation. |
* |
* This resource being per-connection and, in the first place, per-fibril, we |
* don't need to protect it by a futex. |
*/ |
__thread vfs_file_t **files = NULL; |
/** Initialize the table of open files. */ |
bool vfs_files_init(void) |
{ |
if (!files) { |
files = malloc(MAX_OPEN_FILES * sizeof(vfs_file_t *)); |
if (!files) |
return false; |
memset(files, 0, MAX_OPEN_FILES * sizeof(vfs_file_t *)); |
} |
return true; |
} |
/** Allocate a file descriptor. |
* |
* @return First available file descriptor or a negative error |
* code. |
*/ |
int vfs_fd_alloc(void) |
{ |
int i; |
for (i = 0; i < MAX_OPEN_FILES; i++) { |
if (!files[i]) { |
files[i] = (vfs_file_t *) malloc(sizeof(vfs_file_t)); |
if (!files[i]) |
return ENOMEM; |
memset(files[i], 0, sizeof(vfs_file_t)); |
vfs_file_addref(files[i]); |
return i; |
} |
} |
return EMFILE; |
} |
/** Release file descriptor. |
* |
* @param fd File descriptor being released. |
*/ |
void vfs_fd_free(int fd) |
{ |
assert(files[fd] != NULL); |
vfs_file_delref(files[fd]); |
files[fd] = NULL; |
} |
/** Increment reference count of VFS file structure. |
* |
* @param file File structure that will have reference count |
* incremented. |
*/ |
void vfs_file_addref(vfs_file_t *file) |
{ |
/* |
* File structures are per-connection, so no-one, except the current |
* fibril, should have a reference to them. This is the reason we don't |
* do any synchronization here. |
*/ |
file->refcnt++; |
} |
/** Decrement reference count of VFS file structure. |
* |
* @param file File structure that will have reference count |
* decremented. |
*/ |
void vfs_file_delref(vfs_file_t *file) |
{ |
if (file->refcnt-- == 1) { |
/* |
* Lost last reference to a file, need to drop our reference |
* to the underlying VFS node. |
*/ |
vfs_node_delref(file->node); |
free(file); |
} |
} |
/** Find VFS file structure for a given file descriptor. |
* |
* @param fd File descriptor. |
* |
* @return VFS file structure corresponding to fd. |
*/ |
vfs_file_t *vfs_file_get(int fd) |
{ |
return files[fd]; |
} |
/** |
* @} |
*/ |