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From ddb1e6862dffe40bb2929d3a0e3eba198c54ee43 Mon Sep 17 00:00:00 2001
From: Max Reitz <mreitz@redhat.com>
Date: Mon, 10 Nov 2014 09:14:07 +0100
Subject: [PATCH 30/41] qcow2: Add falloc and full preallocation option

Message-id: <1415610847-15383-5-git-send-email-mreitz@redhat.com>
Patchwork-id: 62240
O-Subject: [RHEL-7.1 qemu-kvm PATCH v2 4/4] qcow2: Add falloc and full preallocation option
Bugzilla: 1087724
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>
RH-Acked-by: Fam Zheng <famz@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

From: Hu Tao <hutao@cn.fujitsu.com>

preallocation=falloc allocates disk space by posix_fallocate(),
preallocation=full allocates disk space by writing zeros to disk.
Both modes imply preallocation=metadata.

Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit 0e4271b711a8ea766d29824c844e268b91ac3ae5)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

Conflicts:
	block/qcow2.c

QEMUOptionParameter has not been replaced with QemuOpts downstream,
total_size is in sectors instead of bytes in downstream's
qcow2_create2().

The use of QEMUOptionParameter makes it rather difficult to set an
option in qcow2 for the underlying file to be created. Because qcow2
already used to pass a functionally empty options array, I added an
assertion for this to be true and created a new QEMUOptionParameter
array in case there are actually options to be passed to the protocol
driver (that is, for preallocation).

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block/qcow2.c              | 81 +++++++++++++++++++++++++++++++++++++++-------
 qemu-doc.texi              |  8 +++--
 qemu-img.texi              |  8 +++--
 tests/qemu-iotests/082.out | 54 +++++++++++++++----------------
 4 files changed, 106 insertions(+), 45 deletions(-)

diff --git a/block/qcow2.c b/block/qcow2.c
index 99c6b93..43e54d6 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1557,8 +1557,7 @@ static int preallocate(BlockDriverState *bs)
 static int qcow2_create2(const char *filename, int64_t total_size,
                          const char *backing_file, const char *backing_format,
                          int flags, size_t cluster_size, PreallocMode prealloc,
-                         QEMUOptionParameter *options, int version,
-                         Error **errp)
+                         int version, Error **errp)
 {
     /* Calculate cluster_bits */
     int cluster_bits;
@@ -1588,8 +1587,71 @@ static int qcow2_create2(const char *filename, int64_t total_size,
     uint64_t* refcount_table;
     Error *local_err = NULL;
     int ret;
+    QEMUOptionParameter *options = NULL;
+    BlockDriver *file_drv;
+
+    if (prealloc == PREALLOC_MODE_FULL || prealloc == PREALLOC_MODE_FALLOC) {
+        int64_t meta_size = 0;
+        uint64_t nreftablee, nrefblocke, nl1e, nl2e;
+        int64_t aligned_total_size = align_offset(total_size * BDRV_SECTOR_SIZE,
+                                                  cluster_size);
+
+        /* header: 1 cluster */
+        meta_size += cluster_size;
+
+        /* total size of L2 tables */
+        nl2e = aligned_total_size / cluster_size;
+        nl2e = align_offset(nl2e, cluster_size / sizeof(uint64_t));
+        meta_size += nl2e * sizeof(uint64_t);
+
+        /* total size of L1 tables */
+        nl1e = nl2e * sizeof(uint64_t) / cluster_size;
+        nl1e = align_offset(nl1e, cluster_size / sizeof(uint64_t));
+        meta_size += nl1e * sizeof(uint64_t);
+
+        /* total size of refcount blocks
+         *
+         * note: every host cluster is reference-counted, including metadata
+         * (even refcount blocks are recursively included).
+         * Let:
+         *   a = total_size * BDRV_SECTOR_SIZE (this is the guest disk size)
+         *   m = meta size not including refcount blocks and refcount tables
+         *   c = cluster size
+         *   y1 = number of refcount blocks entries
+         *   y2 = meta size including everything
+         * then,
+         *   y1 = (y2 + a)/c
+         *   y2 = y1 * sizeof(u16) + y1 * sizeof(u16) * sizeof(u64) / c + m
+         * we can get y1:
+         *   y1 = (a + m) / (c - sizeof(u16) - sizeof(u16) * sizeof(u64) / c)
+         */
+        nrefblocke = (aligned_total_size + meta_size + cluster_size) /
+            (cluster_size - sizeof(uint16_t) -
+             1.0 * sizeof(uint16_t) * sizeof(uint64_t) / cluster_size);
+        nrefblocke = align_offset(nrefblocke, cluster_size / sizeof(uint16_t));
+        meta_size += nrefblocke * sizeof(uint16_t);
+
+        /* total size of refcount tables */
+        nreftablee = nrefblocke * sizeof(uint16_t) / cluster_size;
+        nreftablee = align_offset(nreftablee, cluster_size / sizeof(uint64_t));
+        meta_size += nreftablee * sizeof(uint64_t);
+
+        file_drv = bdrv_find_protocol(filename, true);
+        if (file_drv == NULL) {
+            error_setg(errp, "Could not find protocol for file '%s'", filename);
+            return -ENOENT;
+        }
+
+        options = append_option_parameters(options, file_drv->create_options);
+
+        set_option_parameter_int(options, BLOCK_OPT_SIZE,
+                                 aligned_total_size + meta_size);
+        set_option_parameter(options, BLOCK_OPT_PREALLOC,
+                             PreallocMode_lookup[prealloc]);
+    }
 
     ret = bdrv_create_file(filename, options, &local_err);
+    free_option_parameters(options);
     if (ret < 0) {
         error_propagate(errp, local_err);
         return ret;
@@ -1691,7 +1753,7 @@ static int qcow2_create2(const char *filename, int64_t total_size,
     }
 
     /* And if we're supposed to preallocate metadata, do that now */
-    if (prealloc == PREALLOC_MODE_METADATA) {
+    if (prealloc != PREALLOC_MODE_OFF) {
         BDRVQcowState *s = bs->opaque;
         qemu_co_mutex_lock(&s->lock);
         ret = preallocate(bs);
@@ -1761,13 +1823,6 @@ static int qcow2_create(const char *filename, QEMUOptionParameter *options,
         options++;
     }
 
-    if (prealloc != PREALLOC_MODE_OFF &&
-        prealloc != PREALLOC_MODE_METADATA) {
-        error_setg(errp, "Unsupported preallocate mode: %s",
-                   PreallocMode_lookup[prealloc]);
-        return -EINVAL;
-    }
-
     if (backing_file && prealloc != PREALLOC_MODE_OFF) {
         error_setg(errp, "Backing file and preallocation cannot be used at "
                    "the same time");
@@ -1780,8 +1835,9 @@ static int qcow2_create(const char *filename, QEMUOptionParameter *options,
         return -EINVAL;
     }
 
+    assert(!options || !options->name);
     ret = qcow2_create2(filename, sectors, backing_file, backing_fmt, flags,
-                        cluster_size, prealloc, options, version, &local_err);
+                        cluster_size, prealloc, version, &local_err);
     if (error_is_set(&local_err)) {
         error_propagate(errp, local_err);
     }
@@ -2315,7 +2371,8 @@ static QEMUOptionParameter qcow2_create_options[] = {
     {
         .name = BLOCK_OPT_PREALLOC,
         .type = OPT_STRING,
-        .help = "Preallocation mode (allowed values: off, metadata)"
+        .help = "Preallocation mode (allowed values: off, metadata, "
+                "falloc, full)"
     },
     {
         .name = BLOCK_OPT_LAZY_REFCOUNTS,
diff --git a/qemu-doc.texi b/qemu-doc.texi
index dc5b49e..0f7e5f8 100644
--- a/qemu-doc.texi
+++ b/qemu-doc.texi
@@ -567,9 +567,11 @@ sizes can improve the image file size whereas larger cluster sizes generally
 provide better performance.
 
 @item preallocation
-Preallocation mode (allowed values: off, metadata). An image with preallocated
-metadata is initially larger but can improve performance when the image needs
-to grow.
+Preallocation mode (allowed values: @code{off}, @code{metadata}, @code{falloc},
+@code{full}). An image with preallocated metadata is initially larger but can
+improve performance when the image needs to grow. @code{falloc} and @code{full}
+preallocations are like the same options of @code{raw} format, but sets up
+metadata also.
 
 @item lazy_refcounts
 If this option is set to @code{on}, reference count updates are postponed with
diff --git a/qemu-img.texi b/qemu-img.texi
index 80d3261..e943856 100644
--- a/qemu-img.texi
+++ b/qemu-img.texi
@@ -432,9 +432,11 @@ sizes can improve the image file size whereas larger cluster sizes generally
 provide better performance.
 
 @item preallocation
-Preallocation mode (allowed values: off, metadata). An image with preallocated
-metadata is initially larger but can improve performance when the image needs
-to grow.
+Preallocation mode (allowed values: @code{off}, @code{metadata}, @code{falloc},
+@code{full}). An image with preallocated metadata is initially larger but can
+improve performance when the image needs to grow. @code{falloc} and @code{full}
+preallocations are like the same options of @code{raw} format, but sets up
+metadata also.
 
 @item lazy_refcounts
 If this option is set to @code{on}, reference count updates are postponed with
diff --git a/tests/qemu-iotests/082.out b/tests/qemu-iotests/082.out
index d71610b..8abfde7 100644
--- a/tests/qemu-iotests/082.out
+++ b/tests/qemu-iotests/082.out
@@ -64,7 +64,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: create -f qcow2 -o ? TEST_DIR/t.qcow2 128M
@@ -75,7 +75,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: create -f qcow2 -o cluster_size=4k,help TEST_DIR/t.qcow2 128M
@@ -86,7 +86,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: create -f qcow2 -o cluster_size=4k,? TEST_DIR/t.qcow2 128M
@@ -97,7 +97,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: create -f qcow2 -o help,cluster_size=4k TEST_DIR/t.qcow2 128M
@@ -108,7 +108,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: create -f qcow2 -o ?,cluster_size=4k TEST_DIR/t.qcow2 128M
@@ -119,7 +119,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: create -f qcow2 -o cluster_size=4k -o help TEST_DIR/t.qcow2 128M
@@ -130,7 +130,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: create -f qcow2 -o cluster_size=4k -o ? TEST_DIR/t.qcow2 128M
@@ -141,7 +141,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: create -f qcow2 -o backing_file=TEST_DIR/t.qcow2,,help TEST_DIR/t.qcow2 128M
@@ -167,7 +167,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: create -o help
@@ -245,7 +245,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: convert -O qcow2 -o ? TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
@@ -256,7 +256,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: convert -O qcow2 -o cluster_size=4k,help TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
@@ -267,7 +267,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: convert -O qcow2 -o cluster_size=4k,? TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
@@ -278,7 +278,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: convert -O qcow2 -o help,cluster_size=4k TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
@@ -289,7 +289,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: convert -O qcow2 -o ?,cluster_size=4k TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
@@ -300,7 +300,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: convert -O qcow2 -o cluster_size=4k -o help TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
@@ -311,7 +311,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: convert -O qcow2 -o cluster_size=4k -o ? TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
@@ -322,7 +322,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: convert -O qcow2 -o backing_file=TEST_DIR/t.qcow2,,help TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
@@ -348,7 +348,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: convert -o help
@@ -415,7 +415,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: amend -f qcow2 -o ? TEST_DIR/t.qcow2
@@ -426,7 +426,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: amend -f qcow2 -o cluster_size=4k,help TEST_DIR/t.qcow2
@@ -437,7 +437,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: amend -f qcow2 -o cluster_size=4k,? TEST_DIR/t.qcow2
@@ -448,7 +448,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: amend -f qcow2 -o help,cluster_size=4k TEST_DIR/t.qcow2
@@ -459,7 +459,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: amend -f qcow2 -o ?,cluster_size=4k TEST_DIR/t.qcow2
@@ -470,7 +470,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: amend -f qcow2 -o cluster_size=4k -o help TEST_DIR/t.qcow2
@@ -481,7 +481,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: amend -f qcow2 -o cluster_size=4k -o ? TEST_DIR/t.qcow2
@@ -492,7 +492,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: amend -f qcow2 -o backing_file=TEST_DIR/t.qcow2,,help TEST_DIR/t.qcow2
@@ -520,7 +520,7 @@ backing_file     File name of a base image
 backing_fmt      Image format of the base image
 encryption       Encrypt the image
 cluster_size     qcow2 cluster size
-preallocation    Preallocation mode (allowed values: off, metadata)
+preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
 
 Testing: convert -o help
-- 
1.8.3.1