After a long hiatus, I've started looking at GPT and 4k-sector-size disks again.
Conveniently, Matthew Wilcox has done work on the ATA layer, and wrote an 'ata_ram' module which emulates an ATA disk, complete with letting the user specify the reported logical block size. http://git.kernel.org/?p=linux/kernel/git/willy/misc.git;a=summary (see the ata-ram and ata-large-sectors branches; some minor fixups needed to work on current Linus kernels which I'll work with Matthew to get pushed). The patch below (on top of Fedora's source RPM) is necessary to get GPT tables written and read properly on 4k disks. But, it's not sufficient... The next challenge is that anything calling ped_device_{read,write}() does so using "PedSector count" as the implicit length of the buffer. extern int ped_device_read (const PedDevice* dev, void* buffer, PedSector start, PedSector count); extern int ped_device_write (PedDevice* dev, const void* buffer, PedSector start, PedSector count); With only the patch below, the ext2/3 probe() code dies immediately by reading a 4k PedSector into a 512b buffer. Either we'll have to each every caller of these functions that buffer needs to be arbitrarily large (to allow for PedSector to be of variable length) and do the math to munge "PedSector start", or we're going to have to define PedSector to be 512 bytes, and inside these functions, adjust on a per-device basis. I believe the latter is the right choice, as it puts the complications in exactly one place. Thoughts? -- Matt Domsch Linux Technology Strategist, Dell Office of the CTO linux.dell.com & www.dell.com/linux diff --git a/libparted/arch/linux.c b/libparted/arch/linux.c index 462ab92..c48b41d 100644 --- a/libparted/arch/linux.c +++ b/libparted/arch/linux.c @@ -193,7 +193,8 @@ struct hd_driveid { #define BLKRRPART _IO(0x12,95) /* re-read partition table */ #define BLKGETSIZE _IO(0x12,96) /* return device size */ #define BLKFLSBUF _IO(0x12,97) /* flush buffer cache */ -#define BLKSSZGET _IO(0x12,104) /* get block device sector size */ +#define BLKSSZGET _IO(0x12,104) /* get block device physical sector size */ +#define BLKBSZGET _IOR(0x12,112,size_t) /* get block device logical sector size */ #define BLKGETLASTSECT _IO(0x12,108) /* get last sector of block device */ #define BLKSETLASTSECT _IO(0x12,109) /* set last sector of block device */ @@ -539,7 +540,8 @@ static void _device_set_sector_size (PedDevice* dev) { LinuxSpecific* arch_specific = LINUX_SPECIFIC (dev); - int sector_size; + int physical_sector_size=0; + size_t logical_sector_size=0ULL; dev->sector_size = PED_SECTOR_SIZE_DEFAULT; dev->phys_sector_size = PED_SECTOR_SIZE_DEFAULT; @@ -551,15 +553,26 @@ _device_set_sector_size (PedDevice* dev) return; } - if (ioctl (arch_specific->fd, BLKSSZGET, §or_size)) { + if (ioctl (arch_specific->fd, BLKBSZGET, &logical_sector_size)) { ped_exception_throw ( PED_EXCEPTION_WARNING, PED_EXCEPTION_OK, - _("Could not determine sector size for %s: %s.\n" - "Using the default sector size (%lld)."), + _("Could not determine logical sector size for %s: %s.\n" + "Using the default logical sector size (%lld)."), dev->path, strerror (errno), PED_SECTOR_SIZE_DEFAULT); } else { - dev->sector_size = (long long)sector_size; + dev->sector_size = (long long)logical_sector_size; + } + + if (ioctl (arch_specific->fd, BLKSSZGET, &physical_sector_size)) { + ped_exception_throw ( + PED_EXCEPTION_WARNING, + PED_EXCEPTION_OK, + _("Could not determine physical sector size for %s: %s.\n" + "Using the default physical sector size (%lld)."), + dev->path, strerror (errno), PED_SECTOR_SIZE_DEFAULT); + } else { + dev->phys_sector_size = (long long)physical_sector_size; } /* Return PED_SECTOR_SIZE_DEFAULT for DASDs. */ @@ -1447,11 +1460,12 @@ linux_read (const PedDevice* dev, void* buffer, PedSector start, LinuxSpecific* arch_specific = LINUX_SPECIFIC (dev); PedExceptionOption ex_status; void* diobuf = NULL; + size_t buffer_length = PED_SECTOR_SIZE_DEFAULT * count; PED_ASSERT (dev != NULL, return 0); PED_ASSERT (dev->sector_size % PED_SECTOR_SIZE_DEFAULT == 0, return 0); - if (_get_linux_version() < KERNEL_VERSION (2,6,0)) { + if (_get_linux_version() < KERNEL_VERSION (2,6,0) && dev->sector_size == PED_SECTOR_SIZE_DEFAULT) { /* Kludge. This is necessary to read/write the last block of an odd-sized disk, until Linux 2.5.x kernel fixes. */ @@ -1491,6 +1505,7 @@ linux_read (const PedDevice* dev, void* buffer, PedSector start, size_t read_length = count * dev->sector_size; if (posix_memalign (&diobuf, dev->sector_size, read_length) != 0) return 0; + memset(diobuf, 0, read_length); while (1) { ssize_t status = read (arch_specific->fd, diobuf, read_length); @@ -1594,7 +1609,7 @@ linux_write (PedDevice* dev, const void* buffer, PedSector start, return 1; } - if (_get_linux_version() < KERNEL_VERSION (2,6,0)) { + if (_get_linux_version() < KERNEL_VERSION (2,6,0) && dev->sector_size == PED_SECTOR_SIZE_DEFAULT) { /* Kludge. This is necessary to read/write the last block of an odd-sized disk, until Linux 2.5.x kernel fixes. */ @@ -1635,10 +1650,11 @@ linux_write (PedDevice* dev, const void* buffer, PedSector start, dev->path, buffer, (int) start, (int) count); #else dev->dirty = 1; - if (posix_memalign(&diobuf, PED_SECTOR_SIZE_DEFAULT, - count * PED_SECTOR_SIZE_DEFAULT) != 0) + if (posix_memalign(&diobuf, dev->sector_size, + count * dev->sector_size) != 0) return 0; - memcpy(diobuf, buffer, count * PED_SECTOR_SIZE_DEFAULT); + memset(diobuf, 0, count * dev->sector_size); + memcpy(diobuf, buffer, count * dev->sector_size); diobuf_start = diobuf; while (1) { status = write (arch_specific->fd, diobuf, write_length); @@ -1693,9 +1709,10 @@ linux_check (PedDevice* dev, void* buffer, PedSector start, PedSector count) if (!_device_seek (dev, start)) return 0; - if (posix_memalign(&diobuf, PED_SECTOR_SIZE_DEFAULT, - count * PED_SECTOR_SIZE_DEFAULT) != 0) + if (posix_memalign(&diobuf, dev->sector_size, + count * dev->sector_size) != 0) return 0; + memset(diobuf, 0, count * dev->sector_size); for (done = 0; done < count; done += status / dev->sector_size) { status = read (arch_specific->fd, diobuf, diff --git a/libparted/labels/gpt.c b/libparted/labels/gpt.c index f113bcc..4b892ac 100644 --- a/libparted/labels/gpt.c +++ b/libparted/labels/gpt.c @@ -430,6 +430,7 @@ gpt_probe (const PedDevice * dev) { GuidPartitionTableHeader_t* gpt = NULL; uint8_t* pth_raw = ped_malloc (pth_get_size (dev)); + uint8_t* legacy_mbr_buf; LegacyMBR_t legacy_mbr; int gpt_sig_found = 0; @@ -451,7 +452,11 @@ gpt_probe (const PedDevice * dev) if (!gpt_sig_found) return 0; - if (ped_device_read(dev, &legacy_mbr, 0, GPT_HEADER_SECTORS)) { + + legacy_mbr_buf = ped_malloc(dev->sector_size); + if (ped_device_read(dev, legacy_mbr_buf, 0, GPT_HEADER_SECTORS)) { + memcpy(&legacy_mbr, legacy_mbr_buf, sizeof(legacy_mbr)); + ped_free(legacy_mbr_buf); if (!_pmbr_is_valid (&legacy_mbr)) { int ex_status = ped_exception_throw ( PED_EXCEPTION_WARNING, _______________________________________________ parted-devel mailing list [email protected] http://lists.alioth.debian.org/mailman/listinfo/parted-devel
