45,15 → 45,16 |
#include <string.h> |
#include <ctype.h> |
#include <bool.h> |
#include <futex.h> |
#include <libadt/list.h> |
#include <fibril_sync.h> |
#include <adt/list.h> |
#include <as.h> |
#include <assert.h> |
#include <atomic.h> |
#include "vfs.h" |
|
atomic_t fs_head_futex = FUTEX_INITIALIZER; |
link_t fs_head; |
FIBRIL_CONDVAR_INITIALIZE(fs_head_cv); |
FIBRIL_MUTEX_INITIALIZE(fs_head_lock); |
LIST_INITIALIZE(fs_head); |
|
atomic_t fs_handle_next = { |
.count = 1 |
159,7 → 160,7 |
return; |
} |
link_initialize(&fs_info->fs_link); |
futex_initialize(&fs_info->phone_futex, 1); |
fibril_mutex_initialize(&fs_info->phone_lock); |
|
rc = ipc_data_write_finalize(callid, &fs_info->vfs_info, size); |
if (rc != EOK) { |
180,8 → 181,7 |
return; |
} |
|
futex_down(&fs_head_futex); |
fibril_inc_sercount(); |
fibril_mutex_lock(&fs_head_lock); |
|
/* |
* Check for duplicit registrations. |
191,8 → 191,7 |
* We already register a fs like this. |
*/ |
dprintf("FS is already registered.\n"); |
fibril_dec_sercount(); |
futex_up(&fs_head_futex); |
fibril_mutex_unlock(&fs_head_lock); |
free(fs_info); |
ipc_answer_0(callid, EEXISTS); |
ipc_answer_0(rid, EEXISTS); |
214,8 → 213,7 |
if (IPC_GET_METHOD(call) != IPC_M_CONNECT_TO_ME) { |
dprintf("Unexpected call, method = %d\n", IPC_GET_METHOD(call)); |
list_remove(&fs_info->fs_link); |
fibril_dec_sercount(); |
futex_up(&fs_head_futex); |
fibril_mutex_unlock(&fs_head_lock); |
free(fs_info); |
ipc_answer_0(callid, EINVAL); |
ipc_answer_0(rid, EINVAL); |
233,8 → 231,7 |
if (!ipc_share_in_receive(&callid, &size)) { |
dprintf("Unexpected call, method = %d\n", IPC_GET_METHOD(call)); |
list_remove(&fs_info->fs_link); |
fibril_dec_sercount(); |
futex_up(&fs_head_futex); |
fibril_mutex_unlock(&fs_head_lock); |
ipc_hangup(fs_info->phone); |
free(fs_info); |
ipc_answer_0(callid, EINVAL); |
248,8 → 245,7 |
if (size != PLB_SIZE) { |
dprintf("Client suggests wrong size of PFB, size = %d\n", size); |
list_remove(&fs_info->fs_link); |
fibril_dec_sercount(); |
futex_up(&fs_head_futex); |
fibril_mutex_unlock(&fs_head_lock); |
ipc_hangup(fs_info->phone); |
free(fs_info); |
ipc_answer_0(callid, EINVAL); |
273,16 → 269,11 |
fs_info->fs_handle = (fs_handle_t) atomic_postinc(&fs_handle_next); |
ipc_answer_1(rid, EOK, (ipcarg_t) fs_info->fs_handle); |
|
fibril_dec_sercount(); |
futex_up(&fs_head_futex); |
fibril_condvar_broadcast(&fs_head_cv); |
fibril_mutex_unlock(&fs_head_lock); |
|
dprintf("\"%.*s\" filesystem successfully registered, handle=%d.\n", |
FS_NAME_MAXLEN, fs_info->vfs_info.name, fs_info->fs_handle); |
|
/* Process pending mount requests possibly waiting |
* for this filesystem implementation. |
*/ |
vfs_process_pending_mount(); |
} |
|
/** For a given file system handle, implement policy for allocating a phone. |
294,76 → 285,49 |
*/ |
int vfs_grab_phone(fs_handle_t handle) |
{ |
int phone; |
|
/* |
* For now, we don't try to be very clever and very fast. |
* We simply lookup the phone in the fs_head list. We currently don't |
* open any additional phones (even though that itself would be pretty |
* straightforward; housekeeping multiple open phones to a FS task would |
* be more demanding). Instead, we simply take the respective |
* phone_futex and keep it until vfs_release_phone(). |
* For now, we don't try to be very clever and very fast. We simply |
* lookup the phone in the fs_head list and duplicate it. The duplicate |
* phone will be returned to the client and the client will use it for |
* communication. In the future, we should cache the connections so |
* that they do not have to be reestablished over and over again. |
*/ |
futex_down(&fs_head_futex); |
fibril_mutex_lock(&fs_head_lock); |
link_t *cur; |
fs_info_t *fs; |
for (cur = fs_head.next; cur != &fs_head; cur = cur->next) { |
fs = list_get_instance(cur, fs_info_t, fs_link); |
if (fs->fs_handle == handle) { |
futex_up(&fs_head_futex); |
/* |
* For now, take the futex unconditionally. |
* Oh yeah, serialization rocks. |
* It will be up'ed in vfs_release_phone(). |
*/ |
futex_down(&fs->phone_futex); |
/* |
* Avoid deadlock with other fibrils in the same thread |
* by disabling fibril preemption. |
*/ |
fibril_inc_sercount(); |
return fs->phone; |
fibril_mutex_unlock(&fs_head_lock); |
fibril_mutex_lock(&fs->phone_lock); |
phone = ipc_connect_me_to(fs->phone, 0, 0, 0); |
fibril_mutex_unlock(&fs->phone_lock); |
|
assert(phone > 0); |
return phone; |
} |
} |
futex_up(&fs_head_futex); |
fibril_mutex_unlock(&fs_head_lock); |
return 0; |
} |
|
/** Tell VFS that the phone is in use for any request. |
/** Tell VFS that the phone is not needed anymore. |
* |
* @param phone Phone to FS task. |
*/ |
void vfs_release_phone(int phone) |
{ |
bool found = false; |
|
/* |
* Undo the fibril_inc_sercount() done in vfs_grab_phone(). |
*/ |
fibril_dec_sercount(); |
|
futex_down(&fs_head_futex); |
link_t *cur; |
for (cur = fs_head.next; cur != &fs_head; cur = cur->next) { |
fs_info_t *fs = list_get_instance(cur, fs_info_t, fs_link); |
if (fs->phone == phone) { |
found = true; |
futex_up(&fs_head_futex); |
futex_up(&fs->phone_futex); |
return; |
} |
} |
futex_up(&fs_head_futex); |
|
/* |
* Not good to get here. |
*/ |
assert(found == true); |
/* TODO: implement connection caching */ |
ipc_hangup(phone); |
} |
|
/** Convert file system name to its handle. |
* |
* @param name File system name. |
* @param lock If true, the function will down and up the |
* fs_head_futex. |
* @param lock If true, the function will lock and unlock the |
* fs_head_lock. |
* |
* @return File system handle or zero if file system not found. |
*/ |
372,7 → 336,7 |
int handle = 0; |
|
if (lock) |
futex_down(&fs_head_futex); |
fibril_mutex_lock(&fs_head_lock); |
link_t *cur; |
for (cur = fs_head.next; cur != &fs_head; cur = cur->next) { |
fs_info_t *fs = list_get_instance(cur, fs_info_t, fs_link); |
382,7 → 346,7 |
} |
} |
if (lock) |
futex_up(&fs_head_futex); |
fibril_mutex_unlock(&fs_head_lock); |
return handle; |
} |
|