diff mbox series

[v2,10/29] io: Add generic pwritev/preadv interface

Message ID 20231023203608.26370-11-farosas@suse.de
State New
Headers show
Series migration: File based migration with multifd and fixed-ram | expand

Commit Message

Fabiano Rosas Oct. 23, 2023, 8:35 p.m. UTC 
From: Nikolay Borisov <nborisov@suse.com>

Introduce basic pwritev/preadv support in the generic channel layer.
Specific implementation will follow for the file channel as this is
required in order to support migration streams with fixed location of
each ram page.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
---
 include/io/channel.h | 82 ++++++++++++++++++++++++++++++++++++++++++++
 io/channel.c         | 58 +++++++++++++++++++++++++++++++
 2 files changed, 140 insertions(+)

Comments

Daniel P. Berrangé Oct. 24, 2023, 8:18 a.m. UTC | #1 
On Mon, Oct 23, 2023 at 05:35:49PM -0300, Fabiano Rosas wrote:
> From: Nikolay Borisov <nborisov@suse.com>
> 
> Introduce basic pwritev/preadv support in the generic channel layer.
> Specific implementation will follow for the file channel as this is
> required in order to support migration streams with fixed location of
> each ram page.
> 
> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
> Signed-off-by: Fabiano Rosas <farosas@suse.de>
> ---
>  include/io/channel.h | 82 ++++++++++++++++++++++++++++++++++++++++++++
>  io/channel.c         | 58 +++++++++++++++++++++++++++++++
>  2 files changed, 140 insertions(+)
> 
> diff --git a/include/io/channel.h b/include/io/channel.h
> index fcb19fd672..a8181d576a 100644
> --- a/include/io/channel.h
> +++ b/include/io/channel.h
> @@ -131,6 +131,16 @@ struct QIOChannelClass {
>                             Error **errp);
>  
>      /* Optional callbacks */
> +    ssize_t (*io_pwritev)(QIOChannel *ioc,
> +                          const struct iovec *iov,
> +                          size_t niov,
> +                          off_t offset,
> +                          Error **errp);
> +    ssize_t (*io_preadv)(QIOChannel *ioc,
> +                         const struct iovec *iov,
> +                         size_t niov,
> +                         off_t offset,
> +                         Error **errp);
>      int (*io_shutdown)(QIOChannel *ioc,
>                         QIOChannelShutdown how,
>                         Error **errp);
> @@ -529,6 +539,78 @@ void qio_channel_set_follow_coroutine_ctx(QIOChannel *ioc, bool enabled);
>  int qio_channel_close(QIOChannel *ioc,
>                        Error **errp);
>  
> +/**
> + * qio_channel_pwritev_full
> + * @ioc: the channel object
> + * @iov: the array of memory regions to write data from
> + * @niov: the length of the @iov array
> + * @offset: offset in the channel where writes should begin
> + * @errp: pointer to a NULL-initialized error object
> + *
> + * Not all implementations will support this facility, so may report
> + * an error. To avoid errors, the caller may check for the feature
> + * flag QIO_CHANNEL_FEATURE_SEEKABLE prior to calling this method.
> + *
> + * Behaves as qio_channel_writev_full, apart from not supporting
> + * sending of file handles as well as beginning the write at the
> + * passed @offset
> + *
> + */
> +ssize_t qio_channel_pwritev_full(QIOChannel *ioc, const struct iovec *iov,
> +                                 size_t niov, off_t offset, Error **errp);

In terms of naming this should be  just "_pwritev".

We don't support FD passing, so the "_full" suffix is not
appropriate

> +
> +/**
> + * qio_channel_pwritev
> + * @ioc: the channel object
> + * @buf: the memory region to write data into
> + * @buflen: the number of bytes to @buf
> + * @offset: offset in the channel where writes should begin
> + * @errp: pointer to a NULL-initialized error object
> + *
> + * Not all implementations will support this facility, so may report
> + * an error. To avoid errors, the caller may check for the feature
> + * flag QIO_CHANNEL_FEATURE_SEEKABLE prior to calling this method.
> + *
> + */
> +ssize_t qio_channel_pwritev(QIOChannel *ioc, char *buf, size_t buflen,
> +                            off_t offset, Error **errp);

This isn't passing a vector of buffers, so it should be just
"pwrite", not "pwritev".

> +
> +/**
> + * qio_channel_preadv_full
> + * @ioc: the channel object
> + * @iov: the array of memory regions to read data into
> + * @niov: the length of the @iov array
> + * @offset: offset in the channel where writes should begin
> + * @errp: pointer to a NULL-initialized error object
> + *
> + * Not all implementations will support this facility, so may report
> + * an error.  To avoid errors, the caller may check for the feature
> + * flag QIO_CHANNEL_FEATURE_SEEKABLE prior to calling this method.
> + *
> + * Behaves as qio_channel_readv_full, apart from not supporting
> + * receiving of file handles as well as beginning the read at the
> + * passed @offset
> + *
> + */
> +ssize_t qio_channel_preadv_full(QIOChannel *ioc, const struct iovec *iov,
> +                                size_t niov, off_t offset, Error **errp);

"preadv"


> +
> +/**
> + * qio_channel_preadv
> + * @ioc: the channel object
> + * @buf: the memory region to write data into
> + * @buflen: the number of bytes to @buf
> + * @offset: offset in the channel where writes should begin
> + * @errp: pointer to a NULL-initialized error object
> + *
> + * Not all implementations will support this facility, so may report
> + * an error.  To avoid errors, the caller may check for the feature
> + * flag QIO_CHANNEL_FEATURE_SEEKABLE prior to calling this method.
> + *
> + */
> +ssize_t qio_channel_preadv(QIOChannel *ioc, char *buf, size_t buflen,
> +                           off_t offset, Error **errp);

"pread"


With regards,
Daniel
Fabiano Rosas Oct. 24, 2023, 7:06 p.m. UTC | #2 
Daniel P. Berrangé <berrange@redhat.com> writes:

> On Mon, Oct 23, 2023 at 05:35:49PM -0300, Fabiano Rosas wrote:
>> From: Nikolay Borisov <nborisov@suse.com>
>> 
>> Introduce basic pwritev/preadv support in the generic channel layer.
>> Specific implementation will follow for the file channel as this is
>> required in order to support migration streams with fixed location of
>> each ram page.
>> 
>> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
>> Signed-off-by: Fabiano Rosas <farosas@suse.de>
>> ---
>>  include/io/channel.h | 82 ++++++++++++++++++++++++++++++++++++++++++++
>>  io/channel.c         | 58 +++++++++++++++++++++++++++++++
>>  2 files changed, 140 insertions(+)
>> 
>> diff --git a/include/io/channel.h b/include/io/channel.h
>> index fcb19fd672..a8181d576a 100644
>> --- a/include/io/channel.h
>> +++ b/include/io/channel.h
>> @@ -131,6 +131,16 @@ struct QIOChannelClass {
>>                             Error **errp);
>>  
>>      /* Optional callbacks */
>> +    ssize_t (*io_pwritev)(QIOChannel *ioc,
>> +                          const struct iovec *iov,
>> +                          size_t niov,
>> +                          off_t offset,
>> +                          Error **errp);
>> +    ssize_t (*io_preadv)(QIOChannel *ioc,
>> +                         const struct iovec *iov,
>> +                         size_t niov,
>> +                         off_t offset,
>> +                         Error **errp);
>>      int (*io_shutdown)(QIOChannel *ioc,
>>                         QIOChannelShutdown how,
>>                         Error **errp);
>> @@ -529,6 +539,78 @@ void qio_channel_set_follow_coroutine_ctx(QIOChannel *ioc, bool enabled);
>>  int qio_channel_close(QIOChannel *ioc,
>>                        Error **errp);
>>  
>> +/**
>> + * qio_channel_pwritev_full
>> + * @ioc: the channel object
>> + * @iov: the array of memory regions to write data from
>> + * @niov: the length of the @iov array
>> + * @offset: offset in the channel where writes should begin
>> + * @errp: pointer to a NULL-initialized error object
>> + *
>> + * Not all implementations will support this facility, so may report
>> + * an error. To avoid errors, the caller may check for the feature
>> + * flag QIO_CHANNEL_FEATURE_SEEKABLE prior to calling this method.
>> + *
>> + * Behaves as qio_channel_writev_full, apart from not supporting
>> + * sending of file handles as well as beginning the write at the
>> + * passed @offset
>> + *
>> + */
>> +ssize_t qio_channel_pwritev_full(QIOChannel *ioc, const struct iovec *iov,
>> +                                 size_t niov, off_t offset, Error **errp);
>
> In terms of naming this should be  just "_pwritev".
>
> We don't support FD passing, so the "_full" suffix is not
> appropriate
>
>> +
>> +/**
>> + * qio_channel_pwritev
>> + * @ioc: the channel object
>> + * @buf: the memory region to write data into
>> + * @buflen: the number of bytes to @buf
>> + * @offset: offset in the channel where writes should begin
>> + * @errp: pointer to a NULL-initialized error object
>> + *
>> + * Not all implementations will support this facility, so may report
>> + * an error. To avoid errors, the caller may check for the feature
>> + * flag QIO_CHANNEL_FEATURE_SEEKABLE prior to calling this method.
>> + *
>> + */
>> +ssize_t qio_channel_pwritev(QIOChannel *ioc, char *buf, size_t buflen,
>> +                            off_t offset, Error **errp);
>
> This isn't passing a vector of buffers, so it should be just
> "pwrite", not "pwritev".
>
>> +
>> +/**
>> + * qio_channel_preadv_full
>> + * @ioc: the channel object
>> + * @iov: the array of memory regions to read data into
>> + * @niov: the length of the @iov array
>> + * @offset: offset in the channel where writes should begin
>> + * @errp: pointer to a NULL-initialized error object
>> + *
>> + * Not all implementations will support this facility, so may report
>> + * an error.  To avoid errors, the caller may check for the feature
>> + * flag QIO_CHANNEL_FEATURE_SEEKABLE prior to calling this method.
>> + *
>> + * Behaves as qio_channel_readv_full, apart from not supporting
>> + * receiving of file handles as well as beginning the read at the
>> + * passed @offset
>> + *
>> + */
>> +ssize_t qio_channel_preadv_full(QIOChannel *ioc, const struct iovec *iov,
>> +                                size_t niov, off_t offset, Error **errp);
>
> "preadv"
>
>
>> +
>> +/**
>> + * qio_channel_preadv
>> + * @ioc: the channel object
>> + * @buf: the memory region to write data into
>> + * @buflen: the number of bytes to @buf
>> + * @offset: offset in the channel where writes should begin
>> + * @errp: pointer to a NULL-initialized error object
>> + *
>> + * Not all implementations will support this facility, so may report
>> + * an error.  To avoid errors, the caller may check for the feature
>> + * flag QIO_CHANNEL_FEATURE_SEEKABLE prior to calling this method.
>> + *
>> + */
>> +ssize_t qio_channel_preadv(QIOChannel *ioc, char *buf, size_t buflen,
>> +                           off_t offset, Error **errp);
>
> "pread"
>
>
> With regards,
> Daniel

I'll fix all instances.

Thanks
diff mbox series

Patch

diff --git a/include/io/channel.h b/include/io/channel.h
index fcb19fd672..a8181d576a 100644
--- a/include/io/channel.h
+++ b/include/io/channel.h
@@ -131,6 +131,16 @@  struct QIOChannelClass {
                            Error **errp);
 
     /* Optional callbacks */
+    ssize_t (*io_pwritev)(QIOChannel *ioc,
+                          const struct iovec *iov,
+                          size_t niov,
+                          off_t offset,
+                          Error **errp);
+    ssize_t (*io_preadv)(QIOChannel *ioc,
+                         const struct iovec *iov,
+                         size_t niov,
+                         off_t offset,
+                         Error **errp);
     int (*io_shutdown)(QIOChannel *ioc,
                        QIOChannelShutdown how,
                        Error **errp);
@@ -529,6 +539,78 @@  void qio_channel_set_follow_coroutine_ctx(QIOChannel *ioc, bool enabled);
 int qio_channel_close(QIOChannel *ioc,
                       Error **errp);
 
+/**
+ * qio_channel_pwritev_full
+ * @ioc: the channel object
+ * @iov: the array of memory regions to write data from
+ * @niov: the length of the @iov array
+ * @offset: offset in the channel where writes should begin
+ * @errp: pointer to a NULL-initialized error object
+ *
+ * Not all implementations will support this facility, so may report
+ * an error. To avoid errors, the caller may check for the feature
+ * flag QIO_CHANNEL_FEATURE_SEEKABLE prior to calling this method.
+ *
+ * Behaves as qio_channel_writev_full, apart from not supporting
+ * sending of file handles as well as beginning the write at the
+ * passed @offset
+ *
+ */
+ssize_t qio_channel_pwritev_full(QIOChannel *ioc, const struct iovec *iov,
+                                 size_t niov, off_t offset, Error **errp);
+
+/**
+ * qio_channel_pwritev
+ * @ioc: the channel object
+ * @buf: the memory region to write data into
+ * @buflen: the number of bytes to @buf
+ * @offset: offset in the channel where writes should begin
+ * @errp: pointer to a NULL-initialized error object
+ *
+ * Not all implementations will support this facility, so may report
+ * an error. To avoid errors, the caller may check for the feature
+ * flag QIO_CHANNEL_FEATURE_SEEKABLE prior to calling this method.
+ *
+ */
+ssize_t qio_channel_pwritev(QIOChannel *ioc, char *buf, size_t buflen,
+                            off_t offset, Error **errp);
+
+/**
+ * qio_channel_preadv_full
+ * @ioc: the channel object
+ * @iov: the array of memory regions to read data into
+ * @niov: the length of the @iov array
+ * @offset: offset in the channel where writes should begin
+ * @errp: pointer to a NULL-initialized error object
+ *
+ * Not all implementations will support this facility, so may report
+ * an error.  To avoid errors, the caller may check for the feature
+ * flag QIO_CHANNEL_FEATURE_SEEKABLE prior to calling this method.
+ *
+ * Behaves as qio_channel_readv_full, apart from not supporting
+ * receiving of file handles as well as beginning the read at the
+ * passed @offset
+ *
+ */
+ssize_t qio_channel_preadv_full(QIOChannel *ioc, const struct iovec *iov,
+                                size_t niov, off_t offset, Error **errp);
+
+/**
+ * qio_channel_preadv
+ * @ioc: the channel object
+ * @buf: the memory region to write data into
+ * @buflen: the number of bytes to @buf
+ * @offset: offset in the channel where writes should begin
+ * @errp: pointer to a NULL-initialized error object
+ *
+ * Not all implementations will support this facility, so may report
+ * an error.  To avoid errors, the caller may check for the feature
+ * flag QIO_CHANNEL_FEATURE_SEEKABLE prior to calling this method.
+ *
+ */
+ssize_t qio_channel_preadv(QIOChannel *ioc, char *buf, size_t buflen,
+                           off_t offset, Error **errp);
+
 /**
  * qio_channel_shutdown:
  * @ioc: the channel object
diff --git a/io/channel.c b/io/channel.c
index 86c5834510..770d61ea00 100644
--- a/io/channel.c
+++ b/io/channel.c
@@ -454,6 +454,64 @@  GSource *qio_channel_add_watch_source(QIOChannel *ioc,
 }
 
 
+ssize_t qio_channel_pwritev_full(QIOChannel *ioc, const struct iovec *iov,
+                                 size_t niov, off_t offset, Error **errp)
+{
+    QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
+
+    if (!klass->io_pwritev) {
+        error_setg(errp, "Channel does not support pwritev");
+        return -1;
+    }
+
+    if (!qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_SEEKABLE)) {
+        error_setg_errno(errp, EINVAL, "Requested channel is not seekable");
+        return -1;
+    }
+
+    return klass->io_pwritev(ioc, iov, niov, offset, errp);
+}
+
+ssize_t qio_channel_pwritev(QIOChannel *ioc, char *buf, size_t buflen,
+                            off_t offset, Error **errp)
+{
+    struct iovec iov = {
+        .iov_base = buf,
+        .iov_len = buflen
+    };
+
+    return qio_channel_pwritev_full(ioc, &iov, 1, offset, errp);
+}
+
+ssize_t qio_channel_preadv_full(QIOChannel *ioc, const struct iovec *iov,
+                                size_t niov, off_t offset, Error **errp)
+{
+    QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
+
+    if (!klass->io_preadv) {
+        error_setg(errp, "Channel does not support preadv");
+        return -1;
+    }
+
+    if (!qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_SEEKABLE)) {
+        error_setg_errno(errp, EINVAL, "Requested channel is not seekable");
+        return -1;
+    }
+
+    return klass->io_preadv(ioc, iov, niov, offset, errp);
+}
+
+ssize_t qio_channel_preadv(QIOChannel *ioc, char *buf, size_t buflen,
+                           off_t offset, Error **errp)
+{
+    struct iovec iov = {
+        .iov_base = buf,
+        .iov_len = buflen
+    };
+
+    return qio_channel_preadv_full(ioc, &iov, 1, offset, errp);
+}
+
 int qio_channel_shutdown(QIOChannel *ioc,
                          QIOChannelShutdown how,
                          Error **errp)