File 0157-qcow2-Resize-the-cache-upon-image-r.patch of Package qemu.12242

From 87251a05261db958058eb9e7e716a14f5347aa30 Mon Sep 17 00:00:00 2001
From: Leonid Bloch <lbloch@janustech.com>
Date: Wed, 26 Sep 2018 19:04:45 +0300
Subject: [PATCH] qcow2: Resize the cache upon image resizing

The caches are now recalculated upon image resizing. This is done
because the new default behavior of assigning L2 cache relatively to
the image size, implies that the cache will be adapted accordingly
after an image resize.

Signed-off-by: Leonid Bloch <lbloch@janustech.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit 45b4949c7bcdcd998cb42f5c517e80a2657cfd33)
[LM: BSC#1139926]
Signed-off-by: Lin Ma <lma@suse.com>
---
 block/qcow2.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/block/qcow2.c b/block/qcow2.c
index 735d7945d5..2f23cd1283 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -3112,6 +3112,7 @@ static int qcow2_truncate(BlockDriverState *bs, int64_t offset,
     uint64_t old_length;
     int64_t new_l1_size;
     int ret;
+    QDict *options;
 
     if (prealloc != PREALLOC_MODE_OFF && prealloc != PREALLOC_MODE_METADATA &&
         prealloc != PREALLOC_MODE_FALLOC && prealloc != PREALLOC_MODE_FULL)
@@ -3326,6 +3327,8 @@ static int qcow2_truncate(BlockDriverState *bs, int64_t offset,
         }
     }
 
+    bs->total_sectors = offset / BDRV_SECTOR_SIZE;
+
     /* write updated header.size */
     offset = cpu_to_be64(offset);
     ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, size),
@@ -3336,6 +3339,15 @@ static int qcow2_truncate(BlockDriverState *bs, int64_t offset,
     }
 
     s->l1_vm_state_index = new_l1_size;
+
+    /* Update cache sizes */
+    options = qdict_clone_shallow(bs->options);
+    ret = qcow2_update_options(bs, options, s->flags, errp);
+    QDECREF(options);
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "Failed to update the cache size");
+        return ret;
+    }
     return 0;
 }