Blame SOURCES/0028-RHEL-7-All-qemu-kvm-in-RHEL-7-supports-discard-of-qc.patch

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From 7b03df3c1e7c22877bafc73c5436199a0542d0b5 Mon Sep 17 00:00:00 2001
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From: "Richard W.M. Jones" <rjones@redhat.com>
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Date: Wed, 27 May 2015 10:03:00 -0400
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Subject: [PATCH] RHEL 7: All qemu-kvm in RHEL 7 supports discard of qcow2
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 (RHBZ#1225467).
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For rationale behind this, see:
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  https://bugzilla.redhat.com/show_bug.cgi?id=1225467#c2
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---
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 lib/qemu.c | 12 ++----------
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 1 file changed, 2 insertions(+), 10 deletions(-)
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diff --git a/lib/qemu.c b/lib/qemu.c
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index 10bb83105..26b63c3b6 100644
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--- a/lib/qemu.c
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+++ b/lib/qemu.c
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@@ -988,10 +988,6 @@ guestfs_int_discard_possible (guestfs_h *g, struct drive *drv,
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    * discard option on -drive at all.
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    */
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   bool qemu15 = guestfs_int_version_ge (qemu_version, 1, 5, 0);
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-  /* qemu >= 1.6.  This was the first version that supported unmap on
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-   * qcow2 backing files.
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-   */
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-  bool qemu16 = guestfs_int_version_ge (qemu_version, 1, 6, 0);
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   if (!qemu15)
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     NOT_SUPPORTED (g, false,
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@@ -1016,12 +1012,8 @@ guestfs_int_discard_possible (guestfs_h *g, struct drive *drv,
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   }
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   else if (STREQ (drv->src.format, "raw"))
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     /* OK */ ;
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-  else if (STREQ (drv->src.format, "qcow2")) {
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-    if (!qemu16)
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-      NOT_SUPPORTED (g, false,
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-                     _("discard cannot be enabled on this drive: "
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-                       "qemu < 1.6 cannot do discard on qcow2 files"));
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-  }
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+  else if (STREQ (drv->src.format, "qcow2"))
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+    /* OK */ ;
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   else {
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     /* It's possible in future other formats will support discard, but
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      * currently (qemu 1.7) none of them do.
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-- 
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2.21.0
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