From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51460) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W3Nd0-0007Ao-4o for qemu-devel@nongnu.org; Wed, 15 Jan 2014 05:23:26 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1W3Ncs-0000kU-BI for qemu-devel@nongnu.org; Wed, 15 Jan 2014 05:23:18 -0500 Received: from mx1.redhat.com ([209.132.183.28]:16841) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W3Ncs-0000kG-3Q for qemu-devel@nongnu.org; Wed, 15 Jan 2014 05:23:10 -0500 From: Kevin Wolf Date: Wed, 15 Jan 2014 11:22:21 +0100 Message-Id: <1389781375-11774-9-git-send-email-kwolf@redhat.com> In-Reply-To: <1389781375-11774-1-git-send-email-kwolf@redhat.com> References: <1389781375-11774-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [PULL 08/42] gluster: Add support for creating zero-filled image List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: anthony@codemonkey.ws Cc: kwolf@redhat.com, qemu-devel@nongnu.org From: Bharata B Rao GlusterFS supports creation of zero-filled file on GlusterFS volume by means of an API called glfs_zerofill(). Use this API from QEMU to create an image that is filled with zeroes by using the preallocation option of qemu-img. qemu-img create gluster://server/volume/image -o preallocation=full 10G The allowed values for preallocation are 'full' and 'off'. By default preallocation is off and image is not zero-filled. glfs_zerofill() offloads the writing of zeroes to the server and if the storage supports SCSI WRITESAME, GlusterFS server can issue BLKZEROOUT ioctl to achieve the zeroing. Signed-off-by: Bharata B Rao Signed-off-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block/gluster.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 49 insertions(+), 1 deletion(-) diff --git a/block/gluster.c b/block/gluster.c index c11f60c..a009b15 100644 --- a/block/gluster.c +++ b/block/gluster.c @@ -354,6 +354,29 @@ out: g_slice_free(GlusterAIOCB, acb); return ret; } + +static inline bool gluster_supports_zerofill(void) +{ + return 1; +} + +static inline int qemu_gluster_zerofill(struct glfs_fd *fd, int64_t offset, + int64_t size) +{ + return glfs_zerofill(fd, offset, size); +} + +#else +static inline bool gluster_supports_zerofill(void) +{ + return 0; +} + +static inline int qemu_gluster_zerofill(struct glfs_fd *fd, int64_t offset, + int64_t size) +{ + return 0; +} #endif static int qemu_gluster_create(const char *filename, @@ -362,6 +385,7 @@ static int qemu_gluster_create(const char *filename, struct glfs *glfs; struct glfs_fd *fd; int ret = 0; + int prealloc = 0; int64_t total_size = 0; GlusterConf *gconf = g_malloc0(sizeof(GlusterConf)); @@ -374,6 +398,19 @@ static int qemu_gluster_create(const char *filename, 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)) { + if (!options->value.s || !strcmp(options->value.s, "off")) { + prealloc = 0; + } else if (!strcmp(options->value.s, "full") && + gluster_supports_zerofill()) { + prealloc = 1; + } else { + error_setg(errp, "Invalid preallocation mode: '%s'" + " or GlusterFS doesn't support zerofill API", + options->value.s); + ret = -EINVAL; + goto out; + } } options++; } @@ -383,9 +420,15 @@ static int qemu_gluster_create(const char *filename, if (!fd) { ret = -errno; } else { - if (glfs_ftruncate(fd, total_size * BDRV_SECTOR_SIZE) != 0) { + if (!glfs_ftruncate(fd, total_size * BDRV_SECTOR_SIZE)) { + if (prealloc && qemu_gluster_zerofill(fd, 0, + total_size * BDRV_SECTOR_SIZE)) { + ret = -errno; + } + } else { ret = -errno; } + if (glfs_close(fd) != 0) { ret = -errno; } @@ -560,6 +603,11 @@ static QEMUOptionParameter qemu_gluster_create_options[] = { .type = OPT_SIZE, .help = "Virtual disk size" }, + { + .name = BLOCK_OPT_PREALLOC, + .type = OPT_STRING, + .help = "Preallocation mode (allowed values: off, full)" + }, { NULL } }; -- 1.8.1.4