From 9b3702c45245f7bbb51350c25e8cf304c490b96a Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Thu, 7 Nov 2013 07:19:42 +0100
Subject: [PATCH 05/81] block: make bdrv_co_is_allocated static

RH-Author: Paolo Bonzini <pbonzini@redhat.com>
Message-id: <1382084091-16636-6-git-send-email-pbonzini@redhat.com>
Patchwork-id: 54988
O-Subject: [RHEL 7.0 qemu-kvm PATCH 05/26] block: make bdrv_co_is_allocated static
Bugzilla: 989646
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Max Reitz <mreitz@redhat.com>
RH-Acked-by: Kevin Wolf <kwolf@redhat.com>

bdrv_is_allocated can detect coroutine context and go through a fast
path, similar to other block layer functions.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit bdad13b9deec47d5d9eaf7f43867d19a79471244)

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 block.c               |   24 +++++++++++++++---------
 block/raw.c           |    2 +-
 block/stream.c        |    4 ++--
 include/block/block.h |    2 --
 4 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/block.c b/block.c
index d5aeff7..0607cc6 100644
--- a/block.c
+++ b/block.c
@@ -2555,7 +2555,7 @@ static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs,
     if (flags & BDRV_REQ_COPY_ON_READ) {
         int pnum;
 
-        ret = bdrv_co_is_allocated(bs, sector_num, nb_sectors, &pnum);
+        ret = bdrv_is_allocated(bs, sector_num, nb_sectors, &pnum);
         if (ret < 0) {
             goto out;
         }
@@ -3027,8 +3027,9 @@ typedef struct BdrvCoIsAllocatedData {
  * 'nb_sectors' is the max value 'pnum' should be set to.  If nb_sectors goes
  * beyond the end of the disk image it will be clamped.
  */
-int coroutine_fn bdrv_co_is_allocated(BlockDriverState *bs, int64_t sector_num,
-                                      int nb_sectors, int *pnum)
+static int coroutine_fn bdrv_co_is_allocated(BlockDriverState *bs,
+                                             int64_t sector_num,
+                                             int nb_sectors, int *pnum)
 {
     int64_t n;
 
@@ -3078,10 +3079,15 @@ int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
         .done = false,
     };
 
-    co = qemu_coroutine_create(bdrv_is_allocated_co_entry);
-    qemu_coroutine_enter(co, &data);
-    while (!data.done) {
-        qemu_aio_wait();
+    if (qemu_in_coroutine()) {
+        /* Fast-path if already in coroutine context */
+        bdrv_is_allocated_co_entry(&data);
+    } else {
+        co = qemu_coroutine_create(bdrv_is_allocated_co_entry);
+        qemu_coroutine_enter(co, &data);
+        while (!data.done) {
+            qemu_aio_wait();
+        }
     }
     return data.ret;
 }
@@ -3109,8 +3115,8 @@ int coroutine_fn bdrv_co_is_allocated_above(BlockDriverState *top,
     intermediate = top;
     while (intermediate && intermediate != base) {
         int pnum_inter;
-        ret = bdrv_co_is_allocated(intermediate, sector_num, nb_sectors,
-                                   &pnum_inter);
+        ret = bdrv_is_allocated(intermediate, sector_num, nb_sectors,
+                                &pnum_inter);
         if (ret < 0) {
             return ret;
         } else if (ret) {
diff --git a/block/raw.c b/block/raw.c
index 8c81de9..f78ff39 100644
--- a/block/raw.c
+++ b/block/raw.c
@@ -39,7 +39,7 @@ static int coroutine_fn raw_co_is_allocated(BlockDriverState *bs,
                                             int64_t sector_num,
                                             int nb_sectors, int *pnum)
 {
-    return bdrv_co_is_allocated(bs->file, sector_num, nb_sectors, pnum);
+    return bdrv_is_allocated(bs->file, sector_num, nb_sectors, pnum);
 }
 
 static int coroutine_fn raw_co_write_zeroes(BlockDriverState *bs,
diff --git a/block/stream.c b/block/stream.c
index d6df06f..f8efa8a 100644
--- a/block/stream.c
+++ b/block/stream.c
@@ -115,8 +115,8 @@ wait:
             break;
         }
 
-        ret = bdrv_co_is_allocated(bs, sector_num,
-                                   STREAM_BUFFER_SIZE / BDRV_SECTOR_SIZE, &n);
+        ret = bdrv_is_allocated(bs, sector_num,
+                                STREAM_BUFFER_SIZE / BDRV_SECTOR_SIZE, &n);
         if (ret == 1) {
             /* Allocated in the top, no need to copy.  */
             copy = false;
diff --git a/include/block/block.h b/include/block/block.h
index 1a3ed22..1932e67 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -192,8 +192,6 @@ int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,
  */
 int coroutine_fn bdrv_co_write_zeroes(BlockDriverState *bs, int64_t sector_num,
     int nb_sectors);
-int coroutine_fn bdrv_co_is_allocated(BlockDriverState *bs, int64_t sector_num,
-    int nb_sectors, int *pnum);
 int coroutine_fn bdrv_co_is_allocated_above(BlockDriverState *top,
                                             BlockDriverState *base,
                                             int64_t sector_num,
-- 
1.7.1