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[PATCH v20 08/20] io: add qio_channel_readv_full_all_eof & qio_channel_r
From: |
Jagannathan Raman |
Subject: |
[PATCH v20 08/20] io: add qio_channel_readv_full_all_eof & qio_channel_readv_full_all helpers |
Date: |
Tue, 19 Jan 2021 15:28:25 -0500 |
From: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Adds qio_channel_readv_full_all_eof() and qio_channel_readv_full_all()
to read both data and FDs. Refactors existing code to use these helpers.
Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
---
include/io/channel.h | 53 ++++++++++++++++++++++++++
io/channel.c | 106 +++++++++++++++++++++++++++++++++++++++++----------
2 files changed, 138 insertions(+), 21 deletions(-)
diff --git a/include/io/channel.h b/include/io/channel.h
index 19e76fc..8898897 100644
--- a/include/io/channel.h
+++ b/include/io/channel.h
@@ -778,6 +778,59 @@ void qio_channel_set_aio_fd_handler(QIOChannel *ioc,
void *opaque);
/**
+ * qio_channel_readv_full_all_eof:
+ * @ioc: the channel object
+ * @iov: the array of memory regions to read data to
+ * @niov: the length of the @iov array
+ * @fds: an array of file handles to read
+ * @nfds: number of file handles in @fds
+ * @errp: pointer to a NULL-initialized error object
+ *
+ *
+ * Performs same function as qio_channel_readv_all_eof.
+ * Additionally, attempts to read file descriptors shared
+ * over the channel. The function will wait for all
+ * requested data to be read, yielding from the current
+ * coroutine if required. data refers to both file
+ * descriptors and the iovs.
+ *
+ * Returns: 1 if all bytes were read, 0 if end-of-file
+ * occurs without data, or -1 on error
+ */
+
+int qio_channel_readv_full_all_eof(QIOChannel *ioc,
+ const struct iovec *iov,
+ size_t niov,
+ int **fds, size_t *nfds,
+ Error **errp);
+
+/**
+ * qio_channel_readv_full_all:
+ * @ioc: the channel object
+ * @iov: the array of memory regions to read data to
+ * @niov: the length of the @iov array
+ * @fds: an array of file handles to read
+ * @nfds: number of file handles in @fds
+ * @errp: pointer to a NULL-initialized error object
+ *
+ *
+ * Performs same function as qio_channel_readv_all_eof.
+ * Additionally, attempts to read file descriptors shared
+ * over the channel. The function will wait for all
+ * requested data to be read, yielding from the current
+ * coroutine if required. data refers to both file
+ * descriptors and the iovs.
+ *
+ * Returns: 0 if all bytes were read, or -1 on error
+ */
+
+int qio_channel_readv_full_all(QIOChannel *ioc,
+ const struct iovec *iov,
+ size_t niov,
+ int **fds, size_t *nfds,
+ Error **errp);
+
+/**
* qio_channel_writev_full_all:
* @ioc: the channel object
* @iov: the array of memory regions to write data from
diff --git a/io/channel.c b/io/channel.c
index 0d4b8b5..b12db9d 100644
--- a/io/channel.c
+++ b/io/channel.c
@@ -92,19 +92,47 @@ int qio_channel_readv_all_eof(QIOChannel *ioc,
size_t niov,
Error **errp)
{
+ return qio_channel_readv_full_all_eof(ioc, iov, niov, NULL, NULL, errp);
+}
+
+int qio_channel_readv_all(QIOChannel *ioc,
+ const struct iovec *iov,
+ size_t niov,
+ Error **errp)
+{
+ return qio_channel_readv_full_all(ioc, iov, niov, NULL, NULL, errp);
+}
+
+int qio_channel_readv_full_all_eof(QIOChannel *ioc,
+ const struct iovec *iov,
+ size_t niov,
+ int **fds, size_t *nfds,
+ Error **errp)
+{
int ret = -1;
struct iovec *local_iov = g_new(struct iovec, niov);
struct iovec *local_iov_head = local_iov;
unsigned int nlocal_iov = niov;
+ int **local_fds = fds;
+ size_t *local_nfds = nfds;
bool partial = false;
+ if (nfds) {
+ *nfds = 0;
+ }
+
+ if (fds) {
+ *fds = NULL;
+ }
+
nlocal_iov = iov_copy(local_iov, nlocal_iov,
iov, niov,
0, iov_size(iov, niov));
- while (nlocal_iov > 0) {
+ while ((nlocal_iov > 0) || local_fds) {
ssize_t len;
- len = qio_channel_readv(ioc, local_iov, nlocal_iov, errp);
+ len = qio_channel_readv_full(ioc, local_iov, nlocal_iov, local_fds,
+ local_nfds, errp);
if (len == QIO_CHANNEL_ERR_BLOCK) {
if (qemu_in_coroutine()) {
qio_channel_yield(ioc, G_IO_IN);
@@ -112,20 +140,53 @@ int qio_channel_readv_all_eof(QIOChannel *ioc,
qio_channel_wait(ioc, G_IO_IN);
}
continue;
- } else if (len < 0) {
- goto cleanup;
- } else if (len == 0) {
- if (partial) {
- error_setg(errp,
- "Unexpected end-of-file before all bytes were
read");
- } else {
- ret = 0;
+ }
+
+ if (len <= 0) {
+ size_t fd_idx;
+
+ if (!len && !niov && (nfds && *nfds)) {
+ break;
+ }
+
+ if (!partial && (!nfds || !(*nfds))) {
+ ret = len;
+ goto cleanup;
}
+
+ error_prepend(errp,
+ "Unexpected end-of-file before all data were read.");
+
+ if (!nfds || !(*nfds)) {
+ goto cleanup;
+ }
+
+ /*
+ * If (len < 0) and fds are returned, it's not clear if the
+ * returned fds are valid to be closed. Just free'ing the
+ * allocated memory for fds in this case
+ */
+ fd_idx = *nfds;
+ while (fd_idx && !len) {
+ close((*fds)[fd_idx - 1]);
+ fd_idx--;
+ }
+
+ g_free(*fds);
+ *fds = NULL;
+ *nfds = 0;
+
goto cleanup;
}
partial = true;
- iov_discard_front(&local_iov, &nlocal_iov, len);
+
+ if (nlocal_iov) {
+ iov_discard_front(&local_iov, &nlocal_iov, len);
+ }
+
+ local_fds = NULL;
+ local_nfds = NULL;
}
ret = 1;
@@ -135,20 +196,23 @@ int qio_channel_readv_all_eof(QIOChannel *ioc,
return ret;
}
-int qio_channel_readv_all(QIOChannel *ioc,
- const struct iovec *iov,
- size_t niov,
- Error **errp)
+int qio_channel_readv_full_all(QIOChannel *ioc,
+ const struct iovec *iov,
+ size_t niov,
+ int **fds, size_t *nfds,
+ Error **errp)
{
- int ret = qio_channel_readv_all_eof(ioc, iov, niov, errp);
+ int ret = qio_channel_readv_full_all_eof(ioc, iov, niov, fds, nfds, errp);
if (ret == 0) {
- ret = -1;
- error_setg(errp,
- "Unexpected end-of-file before all bytes were read");
- } else if (ret == 1) {
- ret = 0;
+ error_prepend(errp,
+ "Unexpected end-of-file before all data were read.");
+ return -1;
}
+ if (ret == 1) {
+ return 0;
+ }
+
return ret;
}
--
1.8.3.1
- [PATCH v20 00/20] Initial support for multi-process Qemu, Jagannathan Raman, 2021/01/19
- [PATCH v20 02/20] multi-process: add configure and usage information, Jagannathan Raman, 2021/01/19
- [PATCH v20 03/20] memory: alloc RAM from file at offset, Jagannathan Raman, 2021/01/19
- [PATCH v20 01/20] multi-process: add the concept description to docs/devel/qemu-multiprocess, Jagannathan Raman, 2021/01/19
- [PATCH v20 04/20] multi-process: Add config option for multi-process QEMU, Jagannathan Raman, 2021/01/19
- [PATCH v20 06/20] multi-process: setup a machine object for remote device process, Jagannathan Raman, 2021/01/19
- [PATCH v20 05/20] multi-process: setup PCI host bridge for remote device, Jagannathan Raman, 2021/01/19
- [PATCH v20 07/20] io: add qio_channel_writev_full_all helper, Jagannathan Raman, 2021/01/19
- [PATCH v20 08/20] io: add qio_channel_readv_full_all_eof & qio_channel_readv_full_all helpers,
Jagannathan Raman <=
- [PATCH v20 09/20] multi-process: define MPQemuMsg format and transmission functions, Jagannathan Raman, 2021/01/19
- [PATCH v20 12/20] multi-process: setup memory manager for remote device, Jagannathan Raman, 2021/01/19
- [PATCH v20 15/20] multi-process: Forward PCI config space acceses to the remote process, Jagannathan Raman, 2021/01/19
- [PATCH v20 17/20] multi-process: Synchronize remote memory, Jagannathan Raman, 2021/01/19
- [PATCH v20 10/20] multi-process: Initialize message handler in remote device, Jagannathan Raman, 2021/01/19
- [PATCH v20 11/20] multi-process: Associate fd of a PCIDevice with its object, Jagannathan Raman, 2021/01/19
- [PATCH v20 13/20] multi-process: introduce proxy object, Jagannathan Raman, 2021/01/19
- [PATCH v20 14/20] multi-process: add proxy communication functions, Jagannathan Raman, 2021/01/19
- [PATCH v20 16/20] multi-process: PCI BAR read/write handling for proxy & remote endpoints, Jagannathan Raman, 2021/01/19