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-rw-r--r--hw/9pfs/virtio-9p.c162
1 files changed, 60 insertions, 102 deletions
diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
index 36a862f1f1..46dc9f7340 100644
--- a/hw/9pfs/virtio-9p.c
+++ b/hw/9pfs/virtio-9p.c
@@ -674,40 +674,6 @@ static size_t pdu_pack(V9fsPDU *pdu, size_t offset, const void *src,
offset, size, 1);
}
-static int pdu_copy_sg(V9fsPDU *pdu, size_t offset, int rx, struct iovec *sg)
-{
- size_t pos = 0;
- int i, j;
- struct iovec *src_sg;
- unsigned int num;
-
- if (rx) {
- src_sg = pdu->elem.in_sg;
- num = pdu->elem.in_num;
- } else {
- src_sg = pdu->elem.out_sg;
- num = pdu->elem.out_num;
- }
-
- j = 0;
- for (i = 0; i < num; i++) {
- if (offset <= pos) {
- sg[j].iov_base = src_sg[i].iov_base;
- sg[j].iov_len = src_sg[i].iov_len;
- j++;
- } else if (offset < (src_sg[i].iov_len + pos)) {
- sg[j].iov_base = src_sg[i].iov_base;
- sg[j].iov_len = src_sg[i].iov_len;
- sg[j].iov_base += (offset - pos);
- sg[j].iov_len -= (offset - pos);
- j++;
- }
- pos += src_sg[i].iov_len;
- }
-
- return j;
-}
-
static size_t pdu_unmarshal(V9fsPDU *pdu, size_t offset, const char *fmt, ...)
{
size_t old_offset = offset;
@@ -743,12 +709,6 @@ static size_t pdu_unmarshal(V9fsPDU *pdu, size_t offset, const char *fmt, ...)
*valp = le64_to_cpu(val);
break;
}
- case 'v': {
- struct iovec *iov = va_arg(ap, struct iovec *);
- int *iovcnt = va_arg(ap, int *);
- *iovcnt = pdu_copy_sg(pdu, offset, 0, iov);
- break;
- }
case 's': {
V9fsString *str = va_arg(ap, V9fsString *);
offset += pdu_unmarshal(pdu, offset, "w", &str->size);
@@ -827,12 +787,6 @@ static size_t pdu_marshal(V9fsPDU *pdu, size_t offset, const char *fmt, ...)
offset += pdu_pack(pdu, offset, &val, sizeof(val));
break;
}
- case 'v': {
- struct iovec *iov = va_arg(ap, struct iovec *);
- int *iovcnt = va_arg(ap, int *);
- *iovcnt = pdu_copy_sg(pdu, offset, 1, iov);
- break;
- }
case 's': {
V9fsString *str = va_arg(ap, V9fsString *);
offset += pdu_marshal(pdu, offset, "w", str->size);
@@ -1143,42 +1097,6 @@ static void stat_to_v9stat_dotl(V9fsState *s, const struct stat *stbuf,
stat_to_qid(stbuf, &v9lstat->qid);
}
-static struct iovec *adjust_sg(struct iovec *sg, int len, int *iovcnt)
-{
- while (len && *iovcnt) {
- if (len < sg->iov_len) {
- sg->iov_len -= len;
- sg->iov_base += len;
- len = 0;
- } else {
- len -= sg->iov_len;
- sg++;
- *iovcnt -= 1;
- }
- }
-
- return sg;
-}
-
-static struct iovec *cap_sg(struct iovec *sg, int cap, int *cnt)
-{
- int i;
- int total = 0;
-
- for (i = 0; i < *cnt; i++) {
- if ((total + sg[i].iov_len) > cap) {
- sg[i].iov_len -= ((total + sg[i].iov_len) - cap);
- i++;
- break;
- }
- total += sg[i].iov_len;
- }
-
- *cnt = i;
-
- return sg;
-}
-
static void print_sg(struct iovec *sg, int cnt)
{
int i;
@@ -1861,6 +1779,38 @@ out:
return count;
}
+/*
+ * Create a QEMUIOVector for a sub-region of PDU iovecs
+ *
+ * @qiov: uninitialized QEMUIOVector
+ * @skip: number of bytes to skip from beginning of PDU
+ * @size: number of bytes to include
+ * @is_write: true - write, false - read
+ *
+ * The resulting QEMUIOVector has heap-allocated iovecs and must be cleaned up
+ * with qemu_iovec_destroy().
+ */
+static void v9fs_init_qiov_from_pdu(QEMUIOVector *qiov, V9fsPDU *pdu,
+ uint64_t skip, size_t size,
+ bool is_write)
+{
+ QEMUIOVector elem;
+ struct iovec *iov;
+ unsigned int niov;
+
+ if (is_write) {
+ iov = pdu->elem.out_sg;
+ niov = pdu->elem.out_num;
+ } else {
+ iov = pdu->elem.in_sg;
+ niov = pdu->elem.in_num;
+ }
+
+ qemu_iovec_init_external(&elem, iov, niov);
+ qemu_iovec_init(qiov, niov);
+ qemu_iovec_copy(qiov, &elem, skip, size);
+}
+
static void v9fs_read(void *opaque)
{
int32_t fid;
@@ -1895,21 +1845,21 @@ static void v9fs_read(void *opaque)
err += pdu_marshal(pdu, offset, "d", count);
err += count;
} else if (fidp->fid_type == P9_FID_FILE) {
- int32_t cnt;
+ QEMUIOVector qiov_full;
+ QEMUIOVector qiov;
int32_t len;
- struct iovec *sg;
- struct iovec iov[128]; /* FIXME: bad, bad, bad */
- sg = iov;
- pdu_marshal(pdu, offset + 4, "v", sg, &cnt);
- sg = cap_sg(sg, max_count, &cnt);
+ v9fs_init_qiov_from_pdu(&qiov_full, pdu, offset + 4, max_count, false);
+ qemu_iovec_init(&qiov, qiov_full.niov);
do {
+ qemu_iovec_reset(&qiov);
+ qemu_iovec_copy(&qiov, &qiov_full, count, qiov_full.size - count);
if (0) {
- print_sg(sg, cnt);
+ print_sg(qiov.iov, qiov.niov);
}
/* Loop in case of EINTR */
do {
- len = v9fs_co_preadv(pdu, fidp, sg, cnt, off);
+ len = v9fs_co_preadv(pdu, fidp, qiov.iov, qiov.niov, off);
if (len >= 0) {
off += len;
count += len;
@@ -1920,11 +1870,12 @@ static void v9fs_read(void *opaque)
err = len;
goto out;
}
- sg = adjust_sg(sg, len, &cnt);
} while (count < max_count && len > 0);
err = offset;
err += pdu_marshal(pdu, offset, "d", count);
err += count;
+ qemu_iovec_destroy(&qiov);
+ qemu_iovec_destroy(&qiov_full);
} else if (fidp->fid_type == P9_FID_XATTR) {
err = v9fs_xattr_read(s, pdu, fidp, off, max_count);
} else {
@@ -2095,7 +2046,6 @@ out:
static void v9fs_write(void *opaque)
{
- int cnt;
ssize_t err;
int32_t fid;
int64_t off;
@@ -2104,13 +2054,14 @@ static void v9fs_write(void *opaque)
int32_t total = 0;
size_t offset = 7;
V9fsFidState *fidp;
- struct iovec iov[128]; /* FIXME: bad, bad, bad */
- struct iovec *sg = iov;
V9fsPDU *pdu = opaque;
V9fsState *s = pdu->s;
+ QEMUIOVector qiov_full;
+ QEMUIOVector qiov;
- pdu_unmarshal(pdu, offset, "dqdv", &fid, &off, &count, sg, &cnt);
- trace_v9fs_write(pdu->tag, pdu->id, fid, off, count, cnt);
+ offset += pdu_unmarshal(pdu, offset, "dqd", &fid, &off, &count);
+ v9fs_init_qiov_from_pdu(&qiov_full, pdu, offset, count, true);
+ trace_v9fs_write(pdu->tag, pdu->id, fid, off, count, qiov_full.niov);
fidp = get_fid(pdu, fid);
if (fidp == NULL) {
@@ -2126,20 +2077,23 @@ static void v9fs_write(void *opaque)
/*
* setxattr operation
*/
- err = v9fs_xattr_write(s, pdu, fidp, off, count, sg, cnt);
+ err = v9fs_xattr_write(s, pdu, fidp, off, count,
+ qiov_full.iov, qiov_full.niov);
goto out;
} else {
err = -EINVAL;
goto out;
}
- sg = cap_sg(sg, count, &cnt);
+ qemu_iovec_init(&qiov, qiov_full.niov);
do {
+ qemu_iovec_reset(&qiov);
+ qemu_iovec_copy(&qiov, &qiov_full, total, qiov_full.size - total);
if (0) {
- print_sg(sg, cnt);
+ print_sg(qiov.iov, qiov.niov);
}
/* Loop in case of EINTR */
do {
- len = v9fs_co_pwritev(pdu, fidp, sg, cnt, off);
+ len = v9fs_co_pwritev(pdu, fidp, qiov.iov, qiov.niov, off);
if (len >= 0) {
off += len;
total += len;
@@ -2148,16 +2102,20 @@ static void v9fs_write(void *opaque)
if (len < 0) {
/* IO error return the error */
err = len;
- goto out;
+ goto out_qiov;
}
- sg = adjust_sg(sg, len, &cnt);
} while (total < count && len > 0);
+
+ offset = 7;
offset += pdu_marshal(pdu, offset, "d", total);
err = offset;
trace_v9fs_write_return(pdu->tag, pdu->id, total, err);
+out_qiov:
+ qemu_iovec_destroy(&qiov);
out:
put_fid(pdu, fidp);
out_nofid:
+ qemu_iovec_destroy(&qiov_full);
complete_pdu(s, pdu, err);
}