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authorPaolo Bonzini <pbonzini@redhat.com>2011-09-19 14:18:33 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2011-12-22 11:53:58 +0100
commitd9a73806585fd89f75f0c411839151863dac7f61 (patch)
tree1d5ec28169d56d447ab4105975bec256ce327e3b /nbd.c
parentaf49bbbe78b16673cea13fea7f4d7d3433bf2646 (diff)
downloadqemu-arm-d9a73806585fd89f75f0c411839151863dac7f61.tar.gz
qemu-nbd: introduce NBDRequest
Move the buffer from NBDExport to a new structure, so that it will be possible to have multiple in-flight requests for the same export (and for the same client too---we get that for free). Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'nbd.c')
-rw-r--r--nbd.c65
1 files changed, 51 insertions, 14 deletions
diff --git a/nbd.c b/nbd.c
index 8d2a3bc113..82eb98db27 100644
--- a/nbd.c
+++ b/nbd.c
@@ -36,6 +36,7 @@
#endif
#include "qemu_socket.h"
+#include "qemu-queue.h"
//#define DEBUG_NBD
@@ -584,29 +585,60 @@ static int nbd_send_reply(int csock, struct nbd_reply *reply)
return 0;
}
+typedef struct NBDRequest NBDRequest;
+
+struct NBDRequest {
+ QSIMPLEQ_ENTRY(NBDRequest) entry;
+ uint8_t *data;
+};
+
struct NBDExport {
BlockDriverState *bs;
off_t dev_offset;
off_t size;
- uint8_t *data;
uint32_t nbdflags;
+ QSIMPLEQ_HEAD(, NBDRequest) requests;
};
+static NBDRequest *nbd_request_get(NBDExport *exp)
+{
+ NBDRequest *req;
+ if (QSIMPLEQ_EMPTY(&exp->requests)) {
+ req = g_malloc0(sizeof(NBDRequest));
+ req->data = qemu_blockalign(exp->bs, NBD_BUFFER_SIZE);
+ } else {
+ req = QSIMPLEQ_FIRST(&exp->requests);
+ QSIMPLEQ_REMOVE_HEAD(&exp->requests, entry);
+ }
+ return req;
+}
+
+static void nbd_request_put(NBDExport *exp, NBDRequest *req)
+{
+ QSIMPLEQ_INSERT_HEAD(&exp->requests, req, entry);
+}
+
NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset,
off_t size, uint32_t nbdflags)
{
NBDExport *exp = g_malloc0(sizeof(NBDExport));
+ QSIMPLEQ_INIT(&exp->requests);
exp->bs = bs;
exp->dev_offset = dev_offset;
exp->nbdflags = nbdflags;
exp->size = size == -1 ? exp->bs->total_sectors * 512 : size;
- exp->data = qemu_blockalign(exp->bs, NBD_BUFFER_SIZE);
return exp;
}
void nbd_export_close(NBDExport *exp)
{
- qemu_vfree(exp->data);
+ while (!QSIMPLEQ_EMPTY(&exp->requests)) {
+ NBDRequest *first = QSIMPLEQ_FIRST(&exp->requests);
+ QSIMPLEQ_REMOVE_HEAD(&exp->requests, entry);
+ qemu_vfree(first->data);
+ g_free(first);
+ }
+
bdrv_close(exp->bs);
g_free(exp);
}
@@ -682,15 +714,17 @@ out:
int nbd_trip(NBDExport *exp, int csock)
{
+ NBDRequest *req = nbd_request_get(exp);
struct nbd_request request;
struct nbd_reply reply;
+ int rc = -1;
int ret;
TRACE("Reading request.");
- ret = nbd_do_receive_request(csock, &request, exp->data);
+ ret = nbd_do_receive_request(csock, &request, req->data);
if (ret == -EIO) {
- return -1;
+ goto out;
}
reply.handle = request.handle;
@@ -715,7 +749,7 @@ int nbd_trip(NBDExport *exp, int csock)
TRACE("Request type is READ");
ret = bdrv_read(exp->bs, (request.from + exp->dev_offset) / 512,
- exp->data, request.len / 512);
+ req->data, request.len / 512);
if (ret < 0) {
LOG("reading from file failed");
reply.error = -ret;
@@ -723,8 +757,8 @@ int nbd_trip(NBDExport *exp, int csock)
}
TRACE("Read %u byte(s)", request.len);
- if (nbd_do_send_reply(csock, &reply, exp->data, request.len) < 0)
- return -1;
+ if (nbd_do_send_reply(csock, &reply, req->data, request.len) < 0)
+ goto out;
break;
case NBD_CMD_WRITE:
TRACE("Request type is WRITE");
@@ -738,7 +772,7 @@ int nbd_trip(NBDExport *exp, int csock)
TRACE("Writing to device");
ret = bdrv_write(exp->bs, (request.from + exp->dev_offset) / 512,
- exp->data, request.len / 512);
+ req->data, request.len / 512);
if (ret < 0) {
LOG("writing to file failed");
reply.error = -ret;
@@ -755,7 +789,7 @@ int nbd_trip(NBDExport *exp, int csock)
}
if (nbd_do_send_reply(csock, &reply, NULL, 0) < 0)
- return -1;
+ goto out;
break;
case NBD_CMD_DISC:
TRACE("Request type is DISCONNECT");
@@ -771,7 +805,7 @@ int nbd_trip(NBDExport *exp, int csock)
}
if (nbd_do_send_reply(csock, &reply, NULL, 0) < 0)
- return -1;
+ goto out;
break;
case NBD_CMD_TRIM:
TRACE("Request type is TRIM");
@@ -782,7 +816,7 @@ int nbd_trip(NBDExport *exp, int csock)
reply.error = -ret;
}
if (nbd_do_send_reply(csock, &reply, NULL, 0) < 0)
- return -1;
+ goto out;
break;
default:
LOG("invalid request type (%u) received", request.type);
@@ -790,13 +824,16 @@ int nbd_trip(NBDExport *exp, int csock)
reply.error = -EINVAL;
error_reply:
if (nbd_do_send_reply(csock, &reply, NULL, 0) == -1)
- return -1;
+ goto out;
break;
}
TRACE("Request/Reply complete");
- return 0;
+ rc = 0;
+out:
+ nbd_request_put(exp, req);
+ return rc;
}
int nbd_negotiate(NBDExport *exp, int csock)