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| author | Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> | 2011-11-17 13:40:32 +0000 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2011-12-05 14:51:38 +0100 |
| commit | fb0490f69feb96b7e92457f176dc834ff0b00b09 (patch) | |
| tree | 78f832101d9988753dac64f1f47946f2fa306a97 /blockdev.c | |
| parent | ab1859218a95977dc6881fcccce328d8146a6bdb (diff) | |
| download | qemu-fb0490f69feb96b7e92457f176dc834ff0b00b09.tar.gz | |
block: add -drive copy-on-read=on|off
This patch adds the -drive copy-on-read=on|off command-line option:
copy-on-read=on|off
copy-on-read is "on" or "off" and enables whether to copy read backing
file sectors into the image file. Copy-on-read avoids accessing the
same backing file sectors repeatedly and is useful when the backing
file is over a slow network. By default copy-on-read is off.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'blockdev.c')
| -rw-r--r-- | blockdev.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/blockdev.c b/blockdev.c index 9068c5b1d0..af4e239b93 100644 --- a/blockdev.c +++ b/blockdev.c @@ -257,6 +257,7 @@ DriveInfo *drive_init(QemuOpts *opts, int default_to_scsi) DriveInfo *dinfo; BlockIOLimit io_limits; int snapshot = 0; + bool copy_on_read; int ret; translation = BIOS_ATA_TRANSLATION_AUTO; @@ -273,6 +274,7 @@ DriveInfo *drive_init(QemuOpts *opts, int default_to_scsi) snapshot = qemu_opt_get_bool(opts, "snapshot", 0); ro = qemu_opt_get_bool(opts, "readonly", 0); + copy_on_read = qemu_opt_get_bool(opts, "copy-on-read", false); file = qemu_opt_get(opts, "file"); serial = qemu_opt_get(opts, "serial"); @@ -546,6 +548,10 @@ DriveInfo *drive_init(QemuOpts *opts, int default_to_scsi) bdrv_flags |= (BDRV_O_SNAPSHOT|BDRV_O_CACHE_WB|BDRV_O_NO_FLUSH); } + if (copy_on_read) { + bdrv_flags |= BDRV_O_COPY_ON_READ; + } + if (media == MEDIA_CDROM) { /* CDROM is fine for any interface, don't check. */ ro = 1; |