1 2 /* Sending requests to VFS and handling the replies. */ 3 4 #define _SYSTEM 1 5 6 #include <minix/callnr.h> 7 #include <minix/com.h> 8 #include <minix/config.h> 9 #include <minix/const.h> 10 #include <minix/ds.h> 11 #include <minix/endpoint.h> 12 #include <minix/minlib.h> 13 #include <minix/type.h> 14 #include <minix/ipc.h> 15 #include <minix/sysutil.h> 16 #include <minix/syslib.h> 17 #include <minix/type.h> 18 #include <minix/bitmap.h> 19 #include <string.h> 20 #include <errno.h> 21 #include <unistd.h> 22 #include <assert.h> 23 #include <sys/param.h> 24 25 #include "proto.h" 26 #include "glo.h" 27 #include "util.h" 28 #include "region.h" 29 #include "sanitycheck.h" 30 31 #define STATELEN 70 32 33 static struct vfs_request_node { 34 message reqmsg; 35 char reqstate[STATELEN]; 36 void *opaque; 37 endpoint_t who; 38 int req_id; 39 vfs_callback_t callback; 40 struct vfs_request_node *next; 41 } *first_queued, *active; 42 43 static void activate(void) 44 { 45 assert(!active); 46 assert(first_queued); 47 48 active = first_queued; 49 first_queued = first_queued->next; 50 51 if(asynsend3(VFS_PROC_NR, &active->reqmsg, AMF_NOREPLY) != OK) 52 panic("VM: asynsend to VFS failed"); 53 } 54 55 #define ID_MAX LONG_MAX 56 57 /*===========================================================================* 58 * vfs_request * 59 *===========================================================================*/ 60 int vfs_request(int reqno, int fd, struct vmproc *vmp, u64_t offset, u32_t len, 61 vfs_callback_t reply_callback, void *cbarg, void *state, int statelen) 62 { 63 /* Perform an asynchronous request to VFS. 64 * We send a message of type VFS_VMCALL to VFS. VFS will respond 65 * with message type VM_VFS_REPLY. We send the request asynchronously 66 * and then handle the reply as it if were a VM_VFS_REPLY request. 67 */ 68 message *m; 69 static int reqid = 0; 70 struct vfs_request_node *reqnode; 71 72 reqid++; 73 74 assert(statelen <= STATELEN); 75 76 if(!SLABALLOC(reqnode)) { 77 printf("vfs_request: no memory for request node\n"); 78 return ENOMEM; 79 } 80 81 m = &reqnode->reqmsg; 82 memset(m, 0, sizeof(*m)); 83 m->m_type = VFS_VMCALL; 84 m->VFS_VMCALL_REQ = reqno; 85 m->VFS_VMCALL_FD = fd; 86 m->VFS_VMCALL_REQID = reqid; 87 m->VFS_VMCALL_ENDPOINT = vmp->vm_endpoint; 88 m->VFS_VMCALL_OFFSET = offset; 89 m->VFS_VMCALL_LENGTH = len; 90 91 reqnode->who = vmp->vm_endpoint; 92 reqnode->req_id = reqid; 93 reqnode->next = first_queued; 94 reqnode->callback = reply_callback; 95 reqnode->opaque = cbarg; 96 if(state) memcpy(reqnode->reqstate, state, statelen); 97 first_queued = reqnode; 98 99 /* Send the request message if none pending. */ 100 if(!active) 101 activate(); 102 103 return OK; 104 } 105 106 /*===========================================================================* 107 * do_vfs_reply * 108 *===========================================================================*/ 109 int do_vfs_reply(message *m) 110 { 111 /* VFS has handled a VM request and VFS has replied. It must be the 112 * active request. 113 */ 114 struct vfs_request_node *orignode = active; 115 vfs_callback_t req_callback; 116 void *cbarg; 117 int n; 118 struct vmproc *vmp; 119 120 assert(active); 121 assert(active->req_id == m->VMV_REQID); 122 123 /* the endpoint may have exited */ 124 if(vm_isokendpt(m->VMV_ENDPOINT, &n) != OK) 125 vmp = NULL; 126 else vmp = &vmproc[n]; 127 128 req_callback = active->callback; 129 cbarg = active->opaque; 130 active = NULL; 131 132 /* Invoke requested reply-callback within VM. */ 133 if(req_callback) req_callback(vmp, m, cbarg, orignode->reqstate); 134 135 SLABFREE(orignode); 136 137 /* Send the next request message if any and not re-activated. */ 138 if(first_queued && !active) 139 activate(); 140 141 return SUSPEND; /* don't reply to the reply */ 142 } 143 144