From baf51e7739a4d176284d2e38e1755afeafcd2ee0 Mon Sep 17 00:00:00 2001 From: Daniel P. Berrange Date: Wed, 27 Apr 2016 11:04:54 +0100 Subject: migration: ensure qemu_fflush() always writes full data amount The QEMUFile writev_buffer / put_buffer functions are expected to write out the full set of requested data, blocking until complete. The qemu_fflush() caller does not expect to deal with partial writes. Clarify the function comments and add a sanity check to the code to catch mistaken implementations. Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Daniel P. Berrange Reviewed-by: Juan Quintela Message-Id: <1461751518-12128-5-git-send-email-berrange@redhat.com> Signed-off-by: Amit Shah --- include/migration/qemu-file.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/migration/qemu-file.h b/include/migration/qemu-file.h index 3f6b4ed581..5909ff06f0 100644 --- a/include/migration/qemu-file.h +++ b/include/migration/qemu-file.h @@ -28,7 +28,8 @@ /* This function writes a chunk of data to a file at the given position. * The pos argument can be ignored if the file is only being used for - * streaming. The handler should try to write all of the data it can. + * streaming. The handler must write all of the data or return a negative + * errno value. */ typedef ssize_t (QEMUFilePutBufferFunc)(void *opaque, const uint8_t *buf, int64_t pos, size_t size); @@ -54,7 +55,8 @@ typedef int (QEMUFileCloseFunc)(void *opaque); typedef int (QEMUFileGetFD)(void *opaque); /* - * This function writes an iovec to file. + * This function writes an iovec to file. The handler must write all + * of the data or return a negative errno value. */ typedef ssize_t (QEMUFileWritevBufferFunc)(void *opaque, struct iovec *iov, int iovcnt, int64_t pos); -- cgit v1.2.3-55-g7522