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From d106c599acad51da2d0eff0d3f87cff867d52f18 Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Mon, 9 Sep 2013 14:28:22 +0200
Subject: [PATCH 31/38] blockdev: Split up 'cache' option
RH-Author: Kevin Wolf <kwolf@redhat.com>
Message-id: <1378736903-18489-32-git-send-email-kwolf@redhat.com>
Patchwork-id: 54218
O-Subject: [RHEL-7.0 qemu-kvm PATCH 31/32] blockdev: Split up 'cache' option
Bugzilla: 1005818
RH-Acked-by: Fam Zheng <famz@redhat.com>
RH-Acked-by: Max Reitz <mreitz@redhat.com>
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
Bugzilla: 1005818
The old 'cache' option really encodes three different boolean flags into
a cache mode name, without providing all combinations. Make them three
separate options instead and translate the old option to the new ones
for drive_init().
The specific boolean options take precedence if the old cache option is
specified as well, so the following options are equivalent:
-drive file=x,cache=none,cache.no-flush=true
-drive file=x,cache.writeback=true,cache.direct=true,cache.no-flush=true
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
(cherry picked from commit 29c4e2b50d95f4a15c3dd62b39f3402f05a34907)
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
blockdev.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++----------
1 file changed, 47 insertions(+), 10 deletions(-)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
blockdev.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++----------
1 files changed, 47 insertions(+), 10 deletions(-)
diff --git a/blockdev.c b/blockdev.c
index 5d4f2f8..8ffed03 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -452,12 +452,15 @@ static DriveInfo *blockdev_init(QemuOpts *all_opts,
}
}
- bdrv_flags |= BDRV_O_CACHE_WB;
- if ((buf = qemu_opt_get(opts, "cache")) != NULL) {
- if (bdrv_parse_cache_flags(buf, &bdrv_flags) != 0) {
- error_report("invalid cache option");
- return NULL;
- }
+ bdrv_flags = 0;
+ if (qemu_opt_get_bool(opts, "cache.writeback", true)) {
+ bdrv_flags |= BDRV_O_CACHE_WB;
+ }
+ if (qemu_opt_get_bool(opts, "cache.direct", false)) {
+ bdrv_flags |= BDRV_O_NOCACHE;
+ }
+ if (qemu_opt_get_bool(opts, "cache.no-flush", true)) {
+ bdrv_flags |= BDRV_O_NO_FLUSH;
}
#ifdef CONFIG_LINUX_AIO
@@ -740,6 +743,8 @@ static void qemu_opt_rename(QemuOpts *opts, const char *from, const char *to)
DriveInfo *drive_init(QemuOpts *all_opts, BlockInterfaceType block_default_type)
{
+ const char *value;
+
/* Change legacy command line options into QMP ones */
qemu_opt_rename(all_opts, "iops", "throttling.iops-total");
qemu_opt_rename(all_opts, "iops_rd", "throttling.iops-read");
@@ -751,6 +756,31 @@ DriveInfo *drive_init(QemuOpts *all_opts, BlockInterfaceType block_default_type)
qemu_opt_rename(all_opts, "readonly", "read-only");
+ value = qemu_opt_get(all_opts, "cache");
+ if (value) {
+ int flags = 0;
+
+ if (bdrv_parse_cache_flags(value, &flags) != 0) {
+ error_report("invalid cache option");
+ return NULL;
+ }
+
+ /* Specific options take precedence */
+ if (!qemu_opt_get(all_opts, "cache.writeback")) {
+ qemu_opt_set_bool(all_opts, "cache.writeback",
+ !!(flags & BDRV_O_CACHE_WB));
+ }
+ if (!qemu_opt_get(all_opts, "cache.direct")) {
+ qemu_opt_set_bool(all_opts, "cache.direct",
+ !!(flags & BDRV_O_NOCACHE));
+ }
+ if (!qemu_opt_get(all_opts, "cache.no-flush")) {
+ qemu_opt_set_bool(all_opts, "cache.no-flush",
+ !!(flags & BDRV_O_NO_FLUSH));
+ }
+ qemu_opt_unset(all_opts, "cache");
+ }
+
return blockdev_init(all_opts, block_default_type);
}
@@ -1674,10 +1704,17 @@ QemuOptsList qemu_common_drive_opts = {
.type = QEMU_OPT_STRING,
.help = "discard operation (ignore/off, unmap/on)",
},{
- .name = "cache",
- .type = QEMU_OPT_STRING,
- .help = "host cache usage (none, writeback, writethrough, "
- "directsync, unsafe)",
+ .name = "cache.writeback",
+ .type = QEMU_OPT_BOOL,
+ .help = "enables writeback mode for any caches",
+ },{
+ .name = "cache.direct",
+ .type = QEMU_OPT_BOOL,
+ .help = "enables use of O_DIRECT (bypass the host page cache)",
+ },{
+ .name = "cache.no-flush",
+ .type = QEMU_OPT_BOOL,
+ .help = "ignore any flush requests for the device",
},{
.name = "aio",
.type = QEMU_OPT_STRING,
--
1.7.1