@@ -606,8 +606,14 @@ uint64_t qemu_get_be64(QEMUFile *f)
return v;
}
-/* compress size bytes of data start at p with specific compression
+/* Compress size bytes of data start at p with specific compression
* level and store the compressed data to the buffer of f.
+ *
+ * When f is not writable, return 0 if f has no space to save the
+ * compressed data.
+ * When f is wirtable and it has no space to save the compressed data,
+ * do fflush first, if f still has no space to save the compressed
+ * data, return 0.
*/
ssize_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size,
@@ -616,7 +622,14 @@ ssize_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size,
ssize_t blen = IO_BUF_SIZE - f->buf_index - sizeof(int32_t);
if (blen < compressBound(size)) {
- return 0;
+ if (!qemu_file_is_writable(f)) {
+ return 0;
+ }
+ qemu_fflush(f);
+ blen = IO_BUF_SIZE - sizeof(int32_t);
+ if (blen < compressBound(size)) {
+ return 0;
+ }
}
if (compress2(f->buf + f->buf_index + sizeof(int32_t), (uLongf *)&blen,
(Bytef *)p, size, level) != Z_OK) {
@@ -624,7 +637,13 @@ ssize_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size,
return 0;
}
qemu_put_be32(f, blen);
+ if (f->ops->writev_buffer) {
+ add_to_iovec(f, f->buf + f->buf_index, blen);
+ }
f->buf_index += blen;
+ if (f->buf_index == IO_BUF_SIZE) {
+ qemu_fflush(f);
+ }
return blen + sizeof(int32_t);
}
Current qemu_put_compression_data can only work with no writable QEMUFile, and can't work with the writable QEMUFile. But it does not provide any measure to prevent users from using it with a writable QEMUFile. We should fix this flaw to make it works with writable QEMUFile. Signed-off-by: Liang Li <liang.z.li@intel.com> --- migration/qemu-file.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-)