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[Qemu-block] [PATCH 5/9] blockdev: Add list of monitor-owned BlockBacken
From: |
Max Reitz |
Subject: |
[Qemu-block] [PATCH 5/9] blockdev: Add list of monitor-owned BlockBackends |
Date: |
Tue, 24 Feb 2015 11:23:16 -0500 |
The monitor does hold references to some BlockBackends so it should have
a list of those BBs; blk_backends is a different list, as it contains
references to all BBs (after a follow-up patch, that is), and that
should not be changed because we do need such a list.
monitor_remove_blk() is idempotent so that we can call it in
blockdev_auto_del() without having to care whether it had been called in
do_drive_del() before. monitor_add_blk() is idempotent for symmetry
reasons (monitor_remove_blk() is, so it would be strange for
monitor_add_blk() not to be).
Signed-off-by: Max Reitz <address@hidden>
---
block/block-backend.c | 34 +++++++++++++++++++++++++++++++++-
blockdev.c | 4 ++++
include/sysemu/block-backend.h | 2 ++
3 files changed, 39 insertions(+), 1 deletion(-)
diff --git a/block/block-backend.c b/block/block-backend.c
index 5a52af2..0eb6216 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -28,6 +28,8 @@ struct BlockBackend {
BlockDriverState *bs;
DriveInfo *legacy_dinfo; /* null unless created by drive_new() */
QTAILQ_ENTRY(BlockBackend) link; /* for blk_backends */
+ QTAILQ_ENTRY(BlockBackend) monitor_link; /* for monitor_block_backends */
+ bool in_monitor_list;
void *dev; /* attached device model, if any */
/* TODO change to DeviceState when all users are qdevified */
@@ -69,6 +71,11 @@ static void drive_info_del(DriveInfo *dinfo);
static QTAILQ_HEAD(, BlockBackend) blk_backends =
QTAILQ_HEAD_INITIALIZER(blk_backends);
+/* All BlockBackends referenced by the monitor and which are iterated through
by
+ * blk_next() */
+static QTAILQ_HEAD(, BlockBackend) monitor_block_backends =
+ QTAILQ_HEAD_INITIALIZER(monitor_block_backends);
+
/*
* Create a new BlockBackend with @name, with a reference count of one.
* @name must not be null or empty.
@@ -232,7 +239,8 @@ void blk_remove_all_bs(void)
*/
BlockBackend *blk_next(BlockBackend *blk)
{
- return blk ? QTAILQ_NEXT(blk, link) : QTAILQ_FIRST(&blk_backends);
+ return blk ? QTAILQ_NEXT(blk, monitor_link)
+ : QTAILQ_FIRST(&monitor_block_backends);
}
/*
@@ -251,6 +259,30 @@ BlockBackend *blk_next_inserted(BlockBackend *blk)
}
/*
+ * Add a BlockBackend into the list of backends referenced by the monitor.
+ * Strictly for use by blockdev.c.
+ */
+void monitor_add_blk(BlockBackend *blk)
+{
+ if (!blk->in_monitor_list) {
+ QTAILQ_INSERT_TAIL(&monitor_block_backends, blk, monitor_link);
+ blk->in_monitor_list = true;
+ }
+}
+
+/*
+ * Remove a BlockBackend from the list of backends referenced by the monitor.
+ * Strictly for use by blockdev.c.
+ */
+void monitor_remove_blk(BlockBackend *blk)
+{
+ if (blk->in_monitor_list) {
+ QTAILQ_REMOVE(&monitor_block_backends, blk, monitor_link);
+ blk->in_monitor_list = false;
+ }
+}
+
+/*
* Return @blk's name, a non-null string.
* Wart: the name is empty iff @blk has been hidden with
* blk_hide_on_behalf_of_do_drive_del().
diff --git a/blockdev.c b/blockdev.c
index 58c74c3..e9158b6 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -143,6 +143,7 @@ void blockdev_auto_del(BlockBackend *blk)
DriveInfo *dinfo = blk_legacy_dinfo(blk);
if (dinfo && dinfo->auto_del) {
+ monitor_remove_blk(blk);
blk_unref(blk);
}
}
@@ -585,6 +586,8 @@ static BlockBackend *blockdev_init(const char *file, QDict
*bs_opts,
blk_set_on_error(blk, on_read_error, on_write_error);
+ monitor_add_blk(blk);
+
err_no_bs_opts:
qemu_opts_del(opts);
return blk;
@@ -2246,6 +2249,7 @@ int do_drive_del(Monitor *mon, const QDict *qdict,
QObject **ret_data)
/* quiesce block driver; prevent further io */
blk_remove_bs(blk);
+ monitor_remove_blk(blk);
/* if we have a device attached to this BlockDriverState
* then we need to make the drive anonymous until the device
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index 2400a7e..397b125 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -73,6 +73,8 @@ BlockBackend *blk_by_name(const char *name);
bool blk_name_taken(const char *name);
BlockBackend *blk_next(BlockBackend *blk);
BlockBackend *blk_next_inserted(BlockBackend *blk);
+void monitor_add_blk(BlockBackend *blk);
+void monitor_remove_blk(BlockBackend *blk);
BlockDriverState *blk_bs(BlockBackend *blk);
void blk_remove_bs(BlockBackend *blk);
--
2.1.0
- [Qemu-block] [PATCH 0/9] blockdev: Further BlockBackend work, Max Reitz, 2015/02/24
- [Qemu-block] [PATCH 7/9] block: Make bdrv_drain_one() public, Max Reitz, 2015/02/24
- [Qemu-block] [PATCH 1/9] block: Add blk_name_taken(), Max Reitz, 2015/02/24
- [Qemu-block] [PATCH 5/9] blockdev: Add list of monitor-owned BlockBackends,
Max Reitz <=
- [Qemu-block] [PATCH 2/9] block: Add blk_next_inserted(), Max Reitz, 2015/02/24
- [Qemu-block] [PATCH 9/9] block: Remove bdrv_states, Max Reitz, 2015/02/24
- [Qemu-block] [PATCH 6/9] blockdev: Remove blk_hide_on_behalf_of_do_drive_del(), Max Reitz, 2015/02/24
- [Qemu-block] [PATCH 3/9] block: Add blk_commit_all() and blk_invalidate_cache_all(), Max Reitz, 2015/02/24
- [Qemu-block] [PATCH 4/9] block: Use BlockBackend more, Max Reitz, 2015/02/24
- [Qemu-block] [PATCH 8/9] block: Move some bdrv_*_all() functions to BB, Max Reitz, 2015/02/24