From 61a3061760caaaaa4f025f5712dcd8f84f2f5d70 Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Mon, 10 Nov 2014 09:14:06 +0100 Subject: [PATCH 29/41] raw-posix: Add falloc and full preallocation option Message-id: <1415610847-15383-4-git-send-email-mreitz@redhat.com> Patchwork-id: 62239 O-Subject: [RHEL-7.1 qemu-kvm PATCH v2 3/4] raw-posix: Add falloc and full preallocation option Bugzilla: 1087724 RH-Acked-by: Laszlo Ersek RH-Acked-by: Fam Zheng RH-Acked-by: Stefan Hajnoczi From: Hu Tao This patch adds a new option preallocation for raw format, and implements falloc and full preallocation. Signed-off-by: Hu Tao Reviewed-by: Max Reitz Signed-off-by: Kevin Wolf (cherry picked from commit 06247428be8037b3739280f82cb29efe8397695f) Signed-off-by: Miroslav Rezanina Conflicts: block/raw-posix.c QEMUOptionParameter has not been replaced with QemuOpts downstream (upstream 6f482f742dd841b45297fb0e5f3d2c81779253be) and no "nocow" downstream. Signed-off-by: Max Reitz --- block/raw-posix.c | 67 +++++++++++++++++++++++++++++++++++++++++++++++++------ qemu-doc.texi | 9 ++++++++ qemu-img.texi | 9 ++++++++ 3 files changed, 78 insertions(+), 7 deletions(-) diff --git a/block/raw-posix.c b/block/raw-posix.c index 9ee5b8e..cfe7452 100644 --- a/block/raw-posix.c +++ b/block/raw-posix.c @@ -30,6 +30,7 @@ #include "block/thread-pool.h" #include "qemu/iov.h" #include "raw-aio.h" +#include "qapi/util.h" #if defined(__APPLE__) && (__MACH__) #include @@ -1230,11 +1231,23 @@ static int raw_create(const char *filename, QEMUOptionParameter *options, int fd; int result = 0; int64_t total_size = 0; + PreallocMode prealloc = PREALLOC_MODE_OFF; + char *buf = NULL; + Error *local_err = NULL; /* Read out options */ while (options && options->name) { if (!strcmp(options->name, BLOCK_OPT_SIZE)) { total_size = options->value.n / BDRV_SECTOR_SIZE; + } else if (!strcmp(options->name, BLOCK_OPT_PREALLOC)) { + prealloc = qapi_enum_parse(PreallocMode_lookup, options->value.s, + PREALLOC_MODE_MAX, PREALLOC_MODE_OFF, + &local_err); + if (local_err) { + error_propagate(errp, local_err); + result = -EINVAL; + goto out; + } } options++; } @@ -1244,16 +1257,51 @@ static int raw_create(const char *filename, QEMUOptionParameter *options, if (fd < 0) { result = -errno; error_setg_errno(errp, -result, "Could not create file"); - } else { - if (ftruncate(fd, total_size * BDRV_SECTOR_SIZE) != 0) { - result = -errno; - error_setg_errno(errp, -result, "Could not resize file"); + goto out; + } + + if (ftruncate(fd, total_size * BDRV_SECTOR_SIZE) != 0) { + result = -errno; + error_setg_errno(errp, -result, "Could not resize file"); + goto out_close; + } + + if (prealloc == PREALLOC_MODE_FALLOC) { + /* posix_fallocate() doesn't set errno. */ + result = -posix_fallocate(fd, 0, total_size * BDRV_SECTOR_SIZE); + if (result != 0) { + error_setg_errno(errp, -result, + "Could not preallocate data for the new file"); } - if (qemu_close(fd) != 0) { - result = -errno; - error_setg_errno(errp, -result, "Could not close the new file"); + } else if (prealloc == PREALLOC_MODE_FULL) { + buf = g_malloc0(65536); + int64_t num = 0, left = total_size * BDRV_SECTOR_SIZE; + + while (left > 0) { + num = MIN(left, 65536); + result = write(fd, buf, num); + if (result < 0) { + result = -errno; + error_setg_errno(errp, -result, + "Could not write to the new file"); + break; + } + left -= num; } + fsync(fd); + g_free(buf); + } else if (prealloc != PREALLOC_MODE_OFF) { + result = -EINVAL; + error_setg(errp, "Unsupported preallocation mode: %s", + PreallocMode_lookup[prealloc]); + } + +out_close: + if (qemu_close(fd) != 0 && result == 0) { + result = -errno; + error_setg_errno(errp, -result, "Could not close the new file"); } +out: return result; } @@ -1404,6 +1452,11 @@ static QEMUOptionParameter raw_create_options[] = { .type = OPT_SIZE, .help = "Virtual disk size" }, + { + .name = BLOCK_OPT_PREALLOC, + .type = OPT_STRING, + .help = "Preallocation mode (allowed values: off, falloc, full)" + }, { NULL } }; diff --git a/qemu-doc.texi b/qemu-doc.texi index 54ab3c5..dc5b49e 100644 --- a/qemu-doc.texi +++ b/qemu-doc.texi @@ -527,6 +527,15 @@ Linux or NTFS on Windows), then only the written sectors will reserve space. Use @code{qemu-img info} to know the real size used by the image or @code{ls -ls} on Unix/Linux. +Supported options: +@table @code +@item preallocation +Preallocation mode (allowed values: @code{off}, @code{falloc}, @code{full}). +@code{falloc} mode preallocates space for image by calling posix_fallocate(). +@code{full} mode preallocates space for image by writing zeros to underlying +storage. +@end table + @item qcow2 QEMU image format, the most versatile format. Use it to have smaller images (useful if your filesystem does not supports holes, for example diff --git a/qemu-img.texi b/qemu-img.texi index 5f99ebb..80d3261 100644 --- a/qemu-img.texi +++ b/qemu-img.texi @@ -392,6 +392,15 @@ Linux or NTFS on Windows), then only the written sectors will reserve space. Use @code{qemu-img info} to know the real size used by the image or @code{ls -ls} on Unix/Linux. +Supported options: +@table @code +@item preallocation +Preallocation mode (allowed values: @code{off}, @code{falloc}, @code{full}). +@code{falloc} mode preallocates space for image by calling posix_fallocate(). +@code{full} mode preallocates space for image by writing zeros to underlying +storage. +@end table + @item qcow2 QEMU image format, the most versatile format. Use it to have smaller images (useful if your filesystem does not supports holes, for example -- 1.8.3.1