Re: [Qemu-block] [PATCH v5 24/38] blockdev: Pull out blockdev option extraction

[Alberto Garcia]

On Fri 18 Sep 2015 05:22:59 PM CEST, Max Reitz  wrote:
> Extract some of the blockdev option extraction code from blockdev_init()
> into its own function. This simplifies blockdev_init() and will allow
> reusing the code in a different function added in a follow-up patch.
>
> Signed-off-by: Max Reitz 

Reviewed-by: Alberto Garcia 

Berto

[Qemu-block] [PATCH v5 24/38] blockdev: Pull out blockdev option extraction

[Max Reitz]

Extract some of the blockdev option extraction code from blockdev_init()
into its own function. This simplifies blockdev_init() and will allow
reusing the code in a different function added in a follow-up patch.

Signed-off-by: Max Reitz 
---
 blockdev.c | 209 +
 1 file changed, 113 insertions(+), 96 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index e76a7de..688ee5f 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -350,25 +350,128 @@ static bool check_throttle_config(ThrottleConfig *cfg, 
Error **errp)
 
 typedef enum { MEDIA_DISK, MEDIA_CDROM } DriveMediaType;
 
+static void extract_common_blockdev_options(QemuOpts *opts, int *bdrv_flags,
+ThrottleConfig *throttle_cfg, BlockdevDetectZeroesOptions *detect_zeroes,
+const char **throttling_group, Error **errp)
+{
+const char *discard;
+Error *local_error = NULL;
+#ifdef CONFIG_LINUX_AIO
+const char *aio;
+#endif
+
+if (!qemu_opt_get_bool(opts, "read-only", false)) {
+*bdrv_flags |= BDRV_O_RDWR;
+}
+if (qemu_opt_get_bool(opts, "copy-on-read", false)) {
+*bdrv_flags |= BDRV_O_COPY_ON_READ;
+}
+
+if ((discard = qemu_opt_get(opts, "discard")) != NULL) {
+if (bdrv_parse_discard_flags(discard, bdrv_flags) != 0) {
+error_setg(errp, "Invalid discard option");
+return;
+}
+}
+
+if (qemu_opt_get_bool(opts, BDRV_OPT_CACHE_WB, true)) {
+*bdrv_flags |= BDRV_O_CACHE_WB;
+}
+if (qemu_opt_get_bool(opts, BDRV_OPT_CACHE_DIRECT, false)) {
+*bdrv_flags |= BDRV_O_NOCACHE;
+}
+if (qemu_opt_get_bool(opts, BDRV_OPT_CACHE_NO_FLUSH, false)) {
+*bdrv_flags |= BDRV_O_NO_FLUSH;
+}
+
+#ifdef CONFIG_LINUX_AIO
+if ((aio = qemu_opt_get(opts, "aio")) != NULL) {
+if (!strcmp(aio, "native")) {
+*bdrv_flags |= BDRV_O_NATIVE_AIO;
+} else if (!strcmp(aio, "threads")) {
+/* this is the default */
+} else {
+   error_setg(errp, "invalid aio option");
+   return;
+}
+}
+#endif
+
+/* disk I/O throttling */
+memset(throttle_cfg, 0, sizeof(*throttle_cfg));
+throttle_cfg->buckets[THROTTLE_BPS_TOTAL].avg =
+qemu_opt_get_number(opts, "throttling.bps-total", 0);
+throttle_cfg->buckets[THROTTLE_BPS_READ].avg  =
+qemu_opt_get_number(opts, "throttling.bps-read", 0);
+throttle_cfg->buckets[THROTTLE_BPS_WRITE].avg =
+qemu_opt_get_number(opts, "throttling.bps-write", 0);
+throttle_cfg->buckets[THROTTLE_OPS_TOTAL].avg =
+qemu_opt_get_number(opts, "throttling.iops-total", 0);
+throttle_cfg->buckets[THROTTLE_OPS_READ].avg =
+qemu_opt_get_number(opts, "throttling.iops-read", 0);
+throttle_cfg->buckets[THROTTLE_OPS_WRITE].avg =
+qemu_opt_get_number(opts, "throttling.iops-write", 0);
+
+throttle_cfg->buckets[THROTTLE_BPS_TOTAL].max =
+qemu_opt_get_number(opts, "throttling.bps-total-max", 0);
+throttle_cfg->buckets[THROTTLE_BPS_READ].max  =
+qemu_opt_get_number(opts, "throttling.bps-read-max", 0);
+throttle_cfg->buckets[THROTTLE_BPS_WRITE].max =
+qemu_opt_get_number(opts, "throttling.bps-write-max", 0);
+throttle_cfg->buckets[THROTTLE_OPS_TOTAL].max =
+qemu_opt_get_number(opts, "throttling.iops-total-max", 0);
+throttle_cfg->buckets[THROTTLE_OPS_READ].max =
+qemu_opt_get_number(opts, "throttling.iops-read-max", 0);
+throttle_cfg->buckets[THROTTLE_OPS_WRITE].max =
+qemu_opt_get_number(opts, "throttling.iops-write-max", 0);
+
+throttle_cfg->op_size =
+qemu_opt_get_number(opts, "throttling.iops-size", 0);
+
+*throttling_group = qemu_opt_get(opts, "throttling.group");
+
+if (!check_throttle_config(throttle_cfg, errp)) {
+return;
+}
+
+*detect_zeroes =
+qapi_enum_parse(BlockdevDetectZeroesOptions_lookup,
+qemu_opt_get(opts, "detect-zeroes"),
+BLOCKDEV_DETECT_ZEROES_OPTIONS_MAX,
+BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
+_error);
+if (local_error) {
+error_propagate(errp, local_error);
+return;
+}
+
+if (*detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
+!(*bdrv_flags & BDRV_O_UNMAP))
+{
+error_setg(errp, "setting detect-zeroes to unmap is not allowed "
+ "without setting discard operation to unmap");
+return;
+}
+}
+
 /* Takes the ownership of bs_opts */
 static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
Error **errp)
 {
 const char *buf;
-int ro = 0;
 int bdrv_flags = 0;
 int on_read_error, on_write_error;
 BlockBackend *blk;
 BlockDriverState *bs;
 ThrottleConfig cfg;
 int snapshot = 0;
-bool copy_on_read;
 Error *error = NULL;
 QemuOpts *opts;