Am 21.01.2014 um 14:03 hat Benoît Canet geschrieben: > Le Friday 17 Jan 2014 à 15:14:58 (+0100), Kevin Wolf a écrit : > > From: Paolo Bonzini <pbonz...@redhat.com> > > > > 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 <pbonz...@redhat.com> > > Signed-off-by: Kevin Wolf <kw...@redhat.com> > > Reviewed-by: Max Reitz <mre...@redhat.com> > > --- > > block.c | 3 ++ > > block/raw-posix.c | 102 > > ++++++++++++++++++++++++++++++++++++++-------- > > block/raw-win32.c | 41 +++++++++++++++++++ > > include/block/block_int.h | 3 ++ > > 4 files changed, 132 insertions(+), 17 deletions(-) > > > > diff --git a/block.c b/block.c > > index b738abe..25ae896 100644 > > --- a/block.c > > +++ b/block.c > > @@ -813,6 +813,7 @@ static int bdrv_open_common(BlockDriverState *bs, > > BlockDriverState *file, > > > > bs->open_flags = flags; > > bs->guest_block_size = 512; > > + bs->request_alignment = 512; > > bs->zero_beyond_eof = true; > > open_flags = bdrv_open_flags(bs, flags); > > bs->read_only = !(open_flags & BDRV_O_RDWR); > > @@ -881,6 +882,8 @@ static int bdrv_open_common(BlockDriverState *bs, > > BlockDriverState *file, > > } > > > > bdrv_refresh_limits(bs); > > + assert(bdrv_opt_mem_align(bs) != 0); > > + assert(bs->request_alignment != 0); > > > > #ifndef _WIN32 > > if (bs->is_temporary) { > > diff --git a/block/raw-posix.c b/block/raw-posix.c > > index 0676037..126a634 100644 > > --- a/block/raw-posix.c > > +++ b/block/raw-posix.c > > @@ -127,6 +127,8 @@ typedef struct BDRVRawState { > > int fd; > > int type; > > int open_flags; > > + size_t buf_align; > > + > > #if defined(__linux__) > > /* linux floppy specific */ > > int64_t fd_open_time; > > @@ -213,6 +215,76 @@ static int raw_normalize_devicepath(const char > > **filename) > > } > > #endif > > > > +static void raw_probe_alignment(BlockDriverState *bs) > > +{ > > + BDRVRawState *s = bs->opaque; > > + char *buf; > > + unsigned int sector_size; > > + > > + /* For /dev/sg devices the alignment is not really used. > > + With buffered I/O, we don't have any restrictions. */ > > + if (bs->sg || !(s->open_flags & O_DIRECT)) { > > + bs->request_alignment = 1; > > + s->buf_align = 1; > > + return; > > + } > > + > > + /* Try a few ioctls to get the right size */ > > + bs->request_alignment = 0; > > + s->buf_align = 0; > > + > > +#ifdef BLKSSZGET > > + if (ioctl(s->fd, BLKSSZGET, §or_size) >= 0) { > > + bs->request_alignment = sector_size; > > + } > > +#endif > > +#ifdef DKIOCGETBLOCKSIZE > > + if (ioctl(s->fd, DKIOCGETBLOCKSIZE, §or_size) >= 0) { > > + bs->request_alignment = sector_size; > > + } > > +#endif > > +#ifdef DIOCGSECTORSIZE > > + if (ioctl(s->fd, DIOCGSECTORSIZE, §or_size) >= 0) { > > + bs->request_alignment = sector_size; > > + } > > +#endif > > +#ifdef CONFIG_XFS > > + if (s->is_xfs) { > > + struct dioattr da; > > + if (xfsctl(NULL, s->fd, XFS_IOC_DIOINFO, &da) >= 0) { > > + bs->request_alignment = da.d_miniosz; > > + /* The kernel returns wrong information for d_mem */ > > + /* s->buf_align = da.d_mem; */ > > + } > > + } > > +#endif > > + > > + /* If we could not get the sizes so far, we can only guess them */ > > + if (!s->buf_align) { > > + size_t align; > > + buf = qemu_memalign(MAX_BLOCKSIZE, 2 * MAX_BLOCKSIZE); > > + for (align = 512; align <= MAX_BLOCKSIZE; align <<= 1) { > > + if (pread(s->fd, buf + align, MAX_BLOCKSIZE, 0) >= 0) { > > + s->buf_align = align; > > + break; > > + } > > + } > > + qemu_vfree(buf); > > + } > > + > > + if (!bs->request_alignment) { > > + size_t align; > > + buf = qemu_memalign(s->buf_align, MAX_BLOCKSIZE); > > + for (align = 512; align <= MAX_BLOCKSIZE; align <<= 1) { > > + if (pread(s->fd, buf, align, 0) >= 0) { > > + bs->request_alignment = align; > > + break; > > + } > > + } > > + qemu_vfree(buf); > > + } > > +} > > + > > static void raw_parse_flags(int bdrv_flags, int *open_flags) > > { > > assert(open_flags != NULL); > > @@ -463,7 +535,6 @@ static int raw_reopen_prepare(BDRVReopenState *state, > > return ret; > > } > > > > - > > static void raw_reopen_commit(BDRVReopenState *state) > > { > > BDRVRawReopenState *raw_s = state->opaque; > > @@ -499,23 +570,15 @@ static void raw_reopen_abort(BDRVReopenState *state) > > state->opaque = NULL; > > } > > > > +static int raw_refresh_limits(BlockDriverState *bs) > > +{ > > + BDRVRawState *s = bs->opaque; > > > > -/* XXX: use host sector size if necessary with: > > -#ifdef DIOCGSECTORSIZE > > - { > > - unsigned int sectorsize = 512; > > - if (!ioctl(fd, DIOCGSECTORSIZE, §orsize) && > > - sectorsize > bufsize) > > - bufsize = sectorsize; > > - } > > -#endif > > -#ifdef CONFIG_COCOA > > - uint32_t blockSize = 512; > > - if ( !ioctl( fd, DKIOCGETBLOCKSIZE, &blockSize ) && blockSize > > > bufsize) { > > - bufsize = blockSize; > > - } > > -#endif > > -*/ > > + raw_probe_alignment(bs); > > + bs->bl.opt_mem_alignment = s->buf_align; > > + > > + return 0; > > +} > > > > static ssize_t handle_aiocb_ioctl(RawPosixAIOData *aiocb) > > { > > @@ -1363,6 +1426,7 @@ static BlockDriver bdrv_file = { > > .bdrv_aio_writev = raw_aio_writev, > > .bdrv_aio_flush = raw_aio_flush, > > .bdrv_aio_discard = raw_aio_discard, > > + .bdrv_refresh_limits = raw_refresh_limits, > > > > .bdrv_truncate = raw_truncate, > > .bdrv_getlength = raw_getlength, > > @@ -1740,6 +1804,7 @@ static BlockDriver bdrv_host_device = { > > .bdrv_aio_writev = raw_aio_writev, > > .bdrv_aio_flush = raw_aio_flush, > > .bdrv_aio_discard = hdev_aio_discard, > > + .bdrv_refresh_limits = raw_refresh_limits, > > > > .bdrv_truncate = raw_truncate, > > .bdrv_getlength = raw_getlength, > > @@ -1871,6 +1936,7 @@ static BlockDriver bdrv_host_floppy = { > > .bdrv_aio_readv = raw_aio_readv, > > .bdrv_aio_writev = raw_aio_writev, > > .bdrv_aio_flush = raw_aio_flush, > > + .bdrv_refresh_limits = raw_refresh_limits, > > > > .bdrv_truncate = raw_truncate, > > .bdrv_getlength = raw_getlength, > > @@ -1981,6 +2047,7 @@ static BlockDriver bdrv_host_cdrom = { > > .bdrv_aio_readv = raw_aio_readv, > > .bdrv_aio_writev = raw_aio_writev, > > .bdrv_aio_flush = raw_aio_flush, > > + .bdrv_refresh_limits = raw_refresh_limits, > > > > .bdrv_truncate = raw_truncate, > > .bdrv_getlength = raw_getlength, > > @@ -2110,6 +2177,7 @@ static BlockDriver bdrv_host_cdrom = { > > .bdrv_aio_readv = raw_aio_readv, > > .bdrv_aio_writev = raw_aio_writev, > > .bdrv_aio_flush = raw_aio_flush, > > + .bdrv_refresh_limits = raw_refresh_limits, > > > > .bdrv_truncate = raw_truncate, > > .bdrv_getlength = raw_getlength, > > diff --git a/block/raw-win32.c b/block/raw-win32.c > > index ce314fd..beb7f23 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]); > > + } > > + > This is not really alignment related. > Does this really belong to this patch ?
raw_probe_alignment() needs the path, so s->drive_path must now be initialised for all images. Without this change it is only set in hdev_open(), i.e. for win32 host_device backends. Kevin