From c25f53b06eba1575d5d0e92a0132455c97825b83 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Tue, 29 Nov 2011 12:42:20 +0100 Subject: raw: Probe required direct I/O alignment Add a bs->request_alignment field that contains the required offset/length alignment for I/O requests and fill it in the raw block drivers. Use ioctls if possible, else see what alignment it takes for O_DIRECT to succeed. While at it, also expose the memory alignment requirements, which may be (and in practice are) different from the disk alignment requirements. Signed-off-by: Paolo Bonzini Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz --- block/raw-win32.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) (limited to 'block/raw-win32.c') diff --git a/block/raw-win32.c b/block/raw-win32.c index ce314fd54f..beb7f2395e 100644 --- a/block/raw-win32.c +++ b/block/raw-win32.c @@ -202,6 +202,35 @@ static int set_sparse(int fd) NULL, 0, NULL, 0, &returned, NULL); } +static void raw_probe_alignment(BlockDriverState *bs) +{ + BDRVRawState *s = bs->opaque; + DWORD sectorsPerCluster, freeClusters, totalClusters, count; + DISK_GEOMETRY_EX dg; + BOOL status; + + if (s->type == FTYPE_CD) { + bs->request_alignment = 2048; + return; + } + if (s->type == FTYPE_HARDDISK) { + status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY_EX, + NULL, 0, &dg, sizeof(dg), &count, NULL); + if (status != 0) { + bs->request_alignment = dg.Geometry.BytesPerSector; + return; + } + /* try GetDiskFreeSpace too */ + } + + if (s->drive_path[0]) { + GetDiskFreeSpace(s->drive_path, §orsPerCluster, + &dg.Geometry.BytesPerSector, + &freeClusters, &totalClusters); + bs->request_alignment = dg.Geometry.BytesPerSector; + } +} + static void raw_parse_flags(int flags, int *access_flags, DWORD *overlapped) { assert(access_flags != NULL); @@ -269,6 +298,17 @@ static int raw_open(BlockDriverState *bs, QDict *options, int flags, } } + if (filename[0] && filename[1] == ':') { + snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", filename[0]); + } else if (filename[0] == '\\' && filename[1] == '\\') { + s->drive_path[0] = 0; + } else { + /* Relative path. */ + char buf[MAX_PATH]; + GetCurrentDirectory(MAX_PATH, buf); + snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", buf[0]); + } + s->hfile = CreateFile(filename, access_flags, FILE_SHARE_READ, NULL, OPEN_EXISTING, overlapped, NULL); @@ -293,6 +333,7 @@ static int raw_open(BlockDriverState *bs, QDict *options, int flags, s->aio = aio; } + raw_probe_alignment(bs); ret = 0; fail: qemu_opts_del(opts); -- cgit v1.2.1