Blame SOURCES/kvm-block-get_block_status-avoid-redundant-callouts-on-r.patch

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From 69813093427b02a4a0e02264abd1f851f2b49249 Mon Sep 17 00:00:00 2001
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From: Paolo Bonzini <pbonzini@redhat.com>
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Date: Thu, 7 Nov 2013 07:23:45 +0100
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Subject: [PATCH 26/81] block/get_block_status: avoid redundant callouts on raw devices
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RH-Author: Paolo Bonzini <pbonzini@redhat.com>
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Message-id: <1382084091-16636-27-git-send-email-pbonzini@redhat.com>
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Patchwork-id: 55009
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O-Subject: [RHEL 7.0 qemu-kvm PATCH 26/26] block/get_block_status: avoid redundant callouts on raw devices
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Bugzilla: 989646
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RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
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RH-Acked-by: Max Reitz <mreitz@redhat.com>
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RH-Acked-by: Kevin Wolf <kwolf@redhat.com>
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From: Peter Lieven <pl@kamp.de>
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if a raw device like an iscsi target or host device is used
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the current implementation makes a second call out to get
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the block status of bs->file.
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Signed-off-by: Peter Lieven <pl@kamp.de>
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Reviewed-by: Eric Blake <eblake@redhat.com>
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Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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(cherry picked from commit 92bc50a5ad7fbc9a0bd17240eaea5027a100ca79)
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Conflicts:
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	block/raw_bsd.c
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Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
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---
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 block.c               |    6 ++++++
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 block/raw.c           |    4 +++-
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 include/block/block.h |    4 ++++
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 3 files changed, 13 insertions(+), 1 deletions(-)
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diff --git a/block.c b/block.c
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index 5c49461..fdff92f 100644
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--- a/block.c
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+++ b/block.c
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@@ -3073,6 +3073,12 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
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         return ret;
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     }
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+    if (ret & BDRV_BLOCK_RAW) {
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+        assert(ret & BDRV_BLOCK_OFFSET_VALID);
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+        return bdrv_get_block_status(bs->file, ret >> BDRV_SECTOR_BITS,
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+                                     *pnum, pnum);
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+    }
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+
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     if (!(ret & BDRV_BLOCK_DATA)) {
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         if (bdrv_has_zero_init(bs)) {
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             ret |= BDRV_BLOCK_ZERO;
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diff --git a/block/raw.c b/block/raw.c
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index 844a222..7d82cf3 100644
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--- a/block/raw.c
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+++ b/block/raw.c
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@@ -39,7 +39,9 @@ static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs,
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                                             int64_t sector_num,
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                                             int nb_sectors, int *pnum)
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 {
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-    return bdrv_get_block_status(bs->file, sector_num, nb_sectors, pnum);
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+    *pnum = nb_sectors;
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+    return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID | BDRV_BLOCK_DATA |
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+           (sector_num << BDRV_SECTOR_BITS);
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 }
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 static int coroutine_fn raw_co_write_zeroes(BlockDriverState *bs,
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diff --git a/include/block/block.h b/include/block/block.h
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index 01f5c65..bc1f5f6 100644
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--- a/include/block/block.h
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+++ b/include/block/block.h
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@@ -95,6 +95,9 @@ typedef struct BlockDevOps {
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 /* BDRV_BLOCK_DATA: data is read from bs->file or another file
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  * BDRV_BLOCK_ZERO: sectors read as zero
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  * BDRV_BLOCK_OFFSET_VALID: sector stored in bs->file as raw data
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+ * BDRV_BLOCK_RAW: used internally to indicate that the request
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+ *                 was answered by the raw driver and that one
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+ *                 should look in bs->file directly.
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  *
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  * If BDRV_BLOCK_OFFSET_VALID is set, bits 9-62 represent the offset in
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  * bs->file where sector data can be read from as raw data.
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@@ -116,6 +119,7 @@ typedef struct BlockDevOps {
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 #define BDRV_BLOCK_DATA         1
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 #define BDRV_BLOCK_ZERO         2
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 #define BDRV_BLOCK_OFFSET_VALID 4
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+#define BDRV_BLOCK_RAW          8
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 #define BDRV_BLOCK_OFFSET_MASK  BDRV_SECTOR_MASK
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 typedef enum {
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-- 
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1.7.1
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