WebSVN – HelenOS – Diff – //trunk/uspace/srv/vfs/vfs_ops.c



#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(int, int, unsigned long, 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.
 */
RWLOCK_INITIALIZE(namespace_rwlock);
 
futex_t rootfs_futex = FUTEX_INITIALIZER;
vfs_triplet_t rootfs = {
    .fs_handle = 0,
    .dev_handle = 0,
    .index = 0,
};

     * 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);
}
 

            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);

        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);

        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);

Rev 2763	Rev 2766
Line 48...	Line 48...
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 <atomic.h>	-
54	#include <vfs/canonify.h>	53	#include <vfs/canonify.h>
55		54
56	/* Forward declarations of static functions. */	55	/* Forward declarations of static functions. */
57	static int vfs_truncate_internal(int, int, unsigned long, size_t);	56	static int vfs_truncate_internal(int, int, unsigned long, size_t);
58		57
Line 60...	Line 59...
60	* This rwlock prevents the race between a triplet-to-VFS-node resolution and a	59	* This rwlock prevents the race between a triplet-to-VFS-node resolution and a
61	* concurrent VFS operation which modifies the file system namespace.	60	* concurrent VFS operation which modifies the file system namespace.
62	*/	61	*/
63	RWLOCK_INITIALIZE(namespace_rwlock);	62	RWLOCK_INITIALIZE(namespace_rwlock);
64		63
65	atomic_t rootfs_futex = FUTEX_INITIALIZER;	64	futex_t rootfs_futex = FUTEX_INITIALIZER;
66	vfs_triplet_t rootfs = {	65	vfs_triplet_t rootfs = {
67	.fs_handle = 0,	66	.fs_handle = 0,
68	.dev_handle = 0,	67	.dev_handle = 0,
69	.index = 0,	68	.index = 0,
70	};	69	};
Line 684...	Line 683...
684	* The name has already been unlinked by vfs_lookup_internal().	683	* The name has already been unlinked by vfs_lookup_internal().
685	* We have to get and put the VFS node to ensure that it is	684	* We have to get and put the VFS node to ensure that it is
686	* VFS_DESTROY'ed after the last reference to it is dropped.	685	* VFS_DESTROY'ed after the last reference to it is dropped.
687	*/	686	*/
688	vfs_node_t *node = vfs_node_get(&lr);	687	vfs_node_t *node = vfs_node_get(&lr);
-		688	futex_down(&nodes_futex);
689	node->lnkcnt--;	689	node->lnkcnt--;
-		690	futex_up(&nodes_futex);
690	rwlock_write_unlock(&namespace_rwlock);	691	rwlock_write_unlock(&namespace_rwlock);
691	vfs_node_put(node);	692	vfs_node_put(node);
692	ipc_answer_0(rid, EOK);	693	ipc_answer_0(rid, EOK);
693	}	694	}
694		695
Line 808...	Line 809...
808	ipc_answer_0(rid, ENOMEM);	809	ipc_answer_0(rid, ENOMEM);
809	free(old);	810	free(old);
810	free(new);	811	free(new);
811	return;	812	return;
812	}	813	}
-		814	futex_down(&nodes_futex);
813	new_node->lnkcnt--;	815	new_node->lnkcnt--;
-		816	futex_up(&nodes_futex);
814	break;	817	break;
815	default:	818	default:
816	rwlock_write_unlock(&namespace_rwlock);	819	rwlock_write_unlock(&namespace_rwlock);
817	ipc_answer_0(rid, ENOTEMPTY);	820	ipc_answer_0(rid, ENOTEMPTY);
818	free(old);	821	free(old);
Line 828...	Line 831...
828	ipc_answer_0(rid, rc);	831	ipc_answer_0(rid, rc);
829	free(old);	832	free(old);
830	free(new);	833	free(new);
831	return;	834	return;
832	}	835	}
-		836	futex_down(&nodes_futex);
833	old_node->lnkcnt++;	837	old_node->lnkcnt++;
-		838	futex_up(&nodes_futex);
834	/* Destroy the link for the old name. */	839	/* Destroy the link for the old name. */
835	rc = vfs_lookup_internal(oldc, L_UNLINK, NULL, NULL);	840	rc = vfs_lookup_internal(oldc, L_UNLINK, NULL, NULL);
836	if (rc != EOK) {	841	if (rc != EOK) {
837	rwlock_write_unlock(&namespace_rwlock);	842	rwlock_write_unlock(&namespace_rwlock);
838	vfs_node_put(old_node);	843	vfs_node_put(old_node);
Line 841...	Line 846...
841	ipc_answer_0(rid, rc);	846	ipc_answer_0(rid, rc);
842	free(old);	847	free(old);
843	free(new);	848	free(new);
844	return;	849	return;
845	}	850	}
-		851	futex_down(&nodes_futex);
846	old_node->lnkcnt--;	852	old_node->lnkcnt--;
-		853	futex_up(&nodes_futex);
847	rwlock_write_unlock(&namespace_rwlock);	854	rwlock_write_unlock(&namespace_rwlock);
848	vfs_node_put(old_node);	855	vfs_node_put(old_node);
849	if (new_node)	856	if (new_node)
850	vfs_node_put(new_node);	857	vfs_node_put(new_node);
851	free(old);	858	free(old);

Subversion Repositories HelenOS

(root)//trunk/uspace/srv/vfs/vfs_ops.c – Rev 2763 → 2766