| |
| #ifdef HAVE_LIBBLKID |
| #include <blkid.h> |
| #endif |
| #include "blkdev.h" |
| |
| #include "fdiskP.h" |
| |
| /** |
| * SECTION: alignment |
| * @title: Alignment |
| * @short_description: functions to align partitions and work with disk topology and geometry |
| * |
| * The libfdisk aligns the end of the partitions to make it possible to align |
| * the next partition to the "grain" (see fdisk_get_grain()). The grain is |
| * usually 1MiB (or more for devices where optimal I/O is greater than 1MiB). |
| * |
| * It means that the library does not align strictly to physical sector size |
| * (or minimal or optimal I/O), but it uses greater granularity. It makes |
| * partition tables more portable. If you copy disk layout from 512-sector to |
| * 4K-sector device, all partitions are still aligned to physical sectors. |
| * |
| * This unified concept also makes partition tables more user friendly, all |
| * tables look same, LBA of the first partition is 2048 sectors everywhere, etc. |
| * |
| * It's recommended to not change any alignment or device properties. All is |
| * initialized by default by fdisk_assign_device(). |
| * |
| * Note that terminology used by libfdisk is: |
| * - device properties: I/O limits (topology), geometry, sector size, ... |
| * - alignment: first, last LBA, grain, ... |
| * |
| * The alignment setting may be modified by disk label driver. |
| */ |
| |
| /* |
| * Alignment according to logical granularity (usually 1MiB) |
| */ |
| static int lba_is_aligned(struct fdisk_context *cxt, fdisk_sector_t lba) |
| { |
| unsigned long granularity = max(cxt->phy_sector_size, cxt->min_io_size); |
| uintmax_t offset; |
| |
| if (cxt->grain > granularity) |
| granularity = cxt->grain; |
| offset = (lba * cxt->sector_size) & (granularity - 1); |
| |
| return !((granularity + cxt->alignment_offset - offset) & (granularity - 1)); |
| } |
| |
| /* |
| * Alignment according to physical device topology (usually minimal i/o size) |
| */ |
| static int lba_is_phy_aligned(struct fdisk_context *cxt, fdisk_sector_t lba) |
| { |
| unsigned long granularity = max(cxt->phy_sector_size, cxt->min_io_size); |
| uintmax_t offset = (lba * cxt->sector_size) & (granularity - 1); |
| |
| return !((granularity + cxt->alignment_offset - offset) & (granularity - 1)); |
| } |
| |
| /** |
| * fdisk_align_lba: |
| * @cxt: context |
| * @lba: address to align |
| * @direction: FDISK_ALIGN_{UP,DOWN,NEAREST} |
| * |
| * This function aligns @lba to the "grain" (see fdisk_get_grain()). If the |
| * device uses alignment offset then the result is moved according the offset |
| * to be on the physical boundary. |
| * |
| * Returns: alignment LBA. |
| */ |
| fdisk_sector_t fdisk_align_lba(struct fdisk_context *cxt, fdisk_sector_t lba, int direction) |
| { |
| fdisk_sector_t res; |
| |
| if (lba_is_aligned(cxt, lba)) |
| res = lba; |
| else { |
| fdisk_sector_t sects_in_phy = cxt->grain / cxt->sector_size; |
| |
| if (lba < cxt->first_lba) |
| res = cxt->first_lba; |
| |
| else if (direction == FDISK_ALIGN_UP) |
| res = ((lba + sects_in_phy) / sects_in_phy) * sects_in_phy; |
| |
| else if (direction == FDISK_ALIGN_DOWN) |
| res = (lba / sects_in_phy) * sects_in_phy; |
| |
| else /* FDISK_ALIGN_NEAREST */ |
| res = ((lba + sects_in_phy / 2) / sects_in_phy) * sects_in_phy; |
| |
| if (cxt->alignment_offset && !lba_is_aligned(cxt, res) && |
| res > cxt->alignment_offset / cxt->sector_size) { |
| /* |
| * apply alignment_offset |
| * |
| * On disk with alignment compensation physical blocks starts |
| * at LBA < 0 (usually LBA -1). It means we have to move LBA |
| * according the offset to be on the physical boundary. |
| */ |
| /* fprintf(stderr, "LBA: %llu apply alignment_offset\n", res); */ |
| res -= (max(cxt->phy_sector_size, cxt->min_io_size) - |
| cxt->alignment_offset) / cxt->sector_size; |
| |
| if (direction == FDISK_ALIGN_UP && res < lba) |
| res += sects_in_phy; |
| } |
| } |
| |
| if (lba != res) |
| DBG(CXT, ul_debugobj(cxt, "LBA %ju -aligned-to-> %ju", |
| (uintmax_t) lba, |
| (uintmax_t) res)); |
| return res; |
| } |
| |
| /** |
| * fdisk_align_lba_in_range: |
| * @cxt: context |
| * @lba: LBA |
| * @start: range start |
| * @stop: range stop |
| * |
| * Align @lba, the result has to be between @start and @stop |
| * |
| * Returns: aligned LBA |
| */ |
| fdisk_sector_t fdisk_align_lba_in_range(struct fdisk_context *cxt, |
| fdisk_sector_t lba, fdisk_sector_t start, fdisk_sector_t stop) |
| { |
| fdisk_sector_t res; |
| |
| start = fdisk_align_lba(cxt, start, FDISK_ALIGN_UP); |
| stop = fdisk_align_lba(cxt, stop, FDISK_ALIGN_DOWN); |
| lba = fdisk_align_lba(cxt, lba, FDISK_ALIGN_NEAREST); |
| |
| if (lba < start) |
| res = start; |
| else if (lba > stop) |
| res = stop; |
| else |
| res = lba; |
| |
| DBG(CXT, ul_debugobj(cxt, "LBA %ju range:<%ju..%ju>, result: %ju", |
| (uintmax_t) lba, |
| (uintmax_t) start, |
| (uintmax_t) stop, |
| (uintmax_t) res)); |
| return res; |
| } |
| |
| /** |
| * fdisk_lba_is_phy_aligned: |
| * @cxt: context |
| * @lba: LBA to check |
| * |
| * Check if the @lba is aligned to physical sector boundary. |
| * |
| * Returns: 1 if aligned. |
| */ |
| int fdisk_lba_is_phy_aligned(struct fdisk_context *cxt, fdisk_sector_t lba) |
| { |
| return lba_is_phy_aligned(cxt, lba); |
| } |
| |
| static unsigned long get_sector_size(int fd) |
| { |
| int sect_sz; |
| |
| if (!blkdev_get_sector_size(fd, §_sz)) |
| return (unsigned long) sect_sz; |
| return DEFAULT_SECTOR_SIZE; |
| } |
| |
| static void recount_geometry(struct fdisk_context *cxt) |
| { |
| if (!cxt->geom.heads) |
| cxt->geom.heads = 255; |
| if (!cxt->geom.sectors) |
| cxt->geom.sectors = 63; |
| |
| cxt->geom.cylinders = cxt->total_sectors / |
| (cxt->geom.heads * cxt->geom.sectors); |
| } |
| |
| /** |
| * fdisk_override_geometry: |
| * @cxt: fdisk context |
| * @cylinders: user specified cylinders |
| * @heads: user specified heads |
| * @sectors: user specified sectors |
| * |
| * Overrides auto-discovery. The function fdisk_reset_device_properties() |
| * restores the original setting. |
| * |
| * The difference between fdisk_override_geometry() and fdisk_save_user_geometry() |
| * is that saved user geometry is persistent setting and it's applied always |
| * when device is assigned to the context or device properties are reseted. |
| * |
| * Returns: 0 on success, < 0 on error. |
| */ |
| int fdisk_override_geometry(struct fdisk_context *cxt, |
| unsigned int cylinders, |
| unsigned int heads, |
| unsigned int sectors) |
| { |
| if (!cxt) |
| return -EINVAL; |
| if (heads) |
| cxt->geom.heads = heads; |
| if (sectors) |
| cxt->geom.sectors = sectors; |
| |
| if (cylinders) |
| cxt->geom.cylinders = cylinders; |
| else |
| recount_geometry(cxt); |
| |
| fdisk_reset_alignment(cxt); |
| |
| DBG(CXT, ul_debugobj(cxt, "override C/H/S: %u/%u/%u", |
| (unsigned) cxt->geom.cylinders, |
| (unsigned) cxt->geom.heads, |
| (unsigned) cxt->geom.sectors)); |
| |
| return 0; |
| } |
| |
| /** |
| * fdisk_save_user_geometry: |
| * @cxt: context |
| * @cylinders: C |
| * @heads: H |
| * @sectors: S |
| * |
| * Save user defined geometry to use it for partitioning. |
| * |
| * The user properties are applied by fdisk_assign_device() or |
| * fdisk_reset_device_properties(). |
| |
| * Returns: <0 on error, 0 on success. |
| */ |
| int fdisk_save_user_geometry(struct fdisk_context *cxt, |
| unsigned int cylinders, |
| unsigned int heads, |
| unsigned int sectors) |
| { |
| if (!cxt) |
| return -EINVAL; |
| |
| if (heads) |
| cxt->user_geom.heads = heads > 256 ? 0 : heads; |
| if (sectors) |
| cxt->user_geom.sectors = sectors >= 64 ? 0 : sectors; |
| if (cylinders) |
| cxt->user_geom.cylinders = cylinders; |
| |
| DBG(CXT, ul_debugobj(cxt, "user C/H/S: %u/%u/%u", |
| (unsigned) cxt->user_geom.cylinders, |
| (unsigned) cxt->user_geom.heads, |
| (unsigned) cxt->user_geom.sectors)); |
| |
| return 0; |
| } |
| |
| /** |
| * fdisk_save_user_sector_size: |
| * @cxt: context |
| * @phy: physical sector size |
| * @log: logicla sector size |
| * |
| * Save user defined sector sizes to use it for partitioning. |
| * |
| * The user properties are applied by fdisk_assign_device() or |
| * fdisk_reset_device_properties(). |
| * |
| * Returns: <0 on error, 0 on success. |
| */ |
| int fdisk_save_user_sector_size(struct fdisk_context *cxt, |
| unsigned int phy, |
| unsigned int log) |
| { |
| if (!cxt) |
| return -EINVAL; |
| |
| DBG(CXT, ul_debugobj(cxt, "user phy/log sector size: %u/%u", phy, log)); |
| |
| cxt->user_pyh_sector = phy; |
| cxt->user_log_sector = log; |
| |
| return 0; |
| } |
| |
| /** |
| * fdisk_has_user_device_properties: |
| * @cxt: context |
| * |
| * Returns: 1 if user specified any properties |
| */ |
| int fdisk_has_user_device_properties(struct fdisk_context *cxt) |
| { |
| return (cxt->user_pyh_sector |
| || cxt->user_log_sector |
| || cxt->user_geom.heads |
| || cxt->user_geom.sectors |
| || cxt->user_geom.cylinders); |
| } |
| |
| int fdisk_apply_user_device_properties(struct fdisk_context *cxt) |
| { |
| if (!cxt) |
| return -EINVAL; |
| |
| DBG(CXT, ul_debugobj(cxt, "appling user device properties")); |
| |
| if (cxt->user_pyh_sector) |
| cxt->phy_sector_size = cxt->user_pyh_sector; |
| if (cxt->user_log_sector) |
| cxt->sector_size = cxt->min_io_size = |
| cxt->io_size = cxt->user_log_sector; |
| |
| if (cxt->user_geom.heads) |
| cxt->geom.heads = cxt->user_geom.heads; |
| if (cxt->user_geom.sectors) |
| cxt->geom.sectors = cxt->user_geom.sectors; |
| |
| if (cxt->user_geom.cylinders) |
| cxt->geom.cylinders = cxt->user_geom.cylinders; |
| else if (cxt->user_geom.heads || cxt->user_geom.sectors) |
| recount_geometry(cxt); |
| |
| fdisk_reset_alignment(cxt); |
| if (cxt->firstsector_bufsz != cxt->sector_size) |
| fdisk_read_firstsector(cxt); |
| |
| DBG(CXT, ul_debugobj(cxt, "new C/H/S: %u/%u/%u", |
| (unsigned) cxt->geom.cylinders, |
| (unsigned) cxt->geom.heads, |
| (unsigned) cxt->geom.sectors)); |
| DBG(CXT, ul_debugobj(cxt, "new log/phy sector size: %u/%u", |
| (unsigned) cxt->sector_size, |
| (unsigned) cxt->phy_sector_size)); |
| |
| return 0; |
| } |
| |
| void fdisk_zeroize_device_properties(struct fdisk_context *cxt) |
| { |
| assert(cxt); |
| |
| cxt->io_size = 0; |
| cxt->optimal_io_size = 0; |
| cxt->min_io_size = 0; |
| cxt->phy_sector_size = 0; |
| cxt->sector_size = 0; |
| cxt->alignment_offset = 0; |
| cxt->grain = 0; |
| cxt->first_lba = 0; |
| cxt->last_lba = 0; |
| cxt->total_sectors = 0; |
| |
| memset(&cxt->geom, 0, sizeof(struct fdisk_geometry)); |
| } |
| |
| /** |
| * fdisk_reset_device_properties: |
| * @cxt: context |
| * |
| * Resets and discovery topology (I/O limits), geometry, re-read the first |
| * rector on the device if necessary and apply user device setting (geometry |
| * and sector size), then initialize alignment according to label driver (see |
| * fdisk_reset_alignment()). |
| * |
| * You don't have to use this function by default, fdisk_assign_device() is |
| * smart enough to initialize all necessary setting. |
| * |
| * Returns: 0 on success, <0 on error. |
| */ |
| int fdisk_reset_device_properties(struct fdisk_context *cxt) |
| { |
| int rc; |
| |
| if (!cxt) |
| return -EINVAL; |
| |
| DBG(CXT, ul_debugobj(cxt, "*** reseting device properties")); |
| |
| fdisk_zeroize_device_properties(cxt); |
| fdisk_discover_topology(cxt); |
| fdisk_discover_geometry(cxt); |
| |
| rc = fdisk_read_firstsector(cxt); |
| if (rc) |
| return rc; |
| |
| fdisk_apply_user_device_properties(cxt); |
| return 0; |
| } |
| |
| /* |
| * Generic (label independent) geometry |
| */ |
| int fdisk_discover_geometry(struct fdisk_context *cxt) |
| { |
| fdisk_sector_t nsects; |
| |
| assert(cxt); |
| assert(cxt->geom.heads == 0); |
| |
| DBG(CXT, ul_debugobj(cxt, "%s: discovering geometry...", cxt->dev_path)); |
| |
| /* get number of 512-byte sectors, and convert it the real sectors */ |
| if (!blkdev_get_sectors(cxt->dev_fd, (unsigned long long *) &nsects)) |
| cxt->total_sectors = (nsects / (cxt->sector_size >> 9)); |
| |
| DBG(CXT, ul_debugobj(cxt, "total sectors: %ju (ioctl=%ju)", |
| (uintmax_t) cxt->total_sectors, |
| (uintmax_t) nsects)); |
| |
| /* what the kernel/bios thinks the geometry is */ |
| blkdev_get_geometry(cxt->dev_fd, &cxt->geom.heads, (unsigned int *) &cxt->geom.sectors); |
| |
| /* obtained heads and sectors */ |
| recount_geometry(cxt); |
| |
| DBG(CXT, ul_debugobj(cxt, "result: C/H/S: %u/%u/%u", |
| (unsigned) cxt->geom.cylinders, |
| (unsigned) cxt->geom.heads, |
| (unsigned) cxt->geom.sectors)); |
| return 0; |
| } |
| |
| int fdisk_discover_topology(struct fdisk_context *cxt) |
| { |
| #ifdef HAVE_LIBBLKID |
| blkid_probe pr; |
| #endif |
| assert(cxt); |
| assert(cxt->sector_size == 0); |
| |
| DBG(CXT, ul_debugobj(cxt, "%s: discovering topology...", cxt->dev_path)); |
| #ifdef HAVE_LIBBLKID |
| DBG(CXT, ul_debugobj(cxt, "initialize libblkid prober")); |
| |
| pr = blkid_new_probe(); |
| if (pr && blkid_probe_set_device(pr, cxt->dev_fd, 0, 0) == 0) { |
| blkid_topology tp = blkid_probe_get_topology(pr); |
| |
| if (tp) { |
| cxt->min_io_size = blkid_topology_get_minimum_io_size(tp); |
| cxt->optimal_io_size = blkid_topology_get_optimal_io_size(tp); |
| cxt->phy_sector_size = blkid_topology_get_physical_sector_size(tp); |
| cxt->alignment_offset = blkid_topology_get_alignment_offset(tp); |
| |
| /* I/O size used by fdisk */ |
| cxt->io_size = cxt->optimal_io_size; |
| if (!cxt->io_size) |
| /* optimal IO is optional, default to minimum IO */ |
| cxt->io_size = cxt->min_io_size; |
| } |
| } |
| blkid_free_probe(pr); |
| #endif |
| |
| cxt->sector_size = get_sector_size(cxt->dev_fd); |
| if (!cxt->phy_sector_size) /* could not discover physical size */ |
| cxt->phy_sector_size = cxt->sector_size; |
| |
| /* no blkid or error, use default values */ |
| if (!cxt->min_io_size) |
| cxt->min_io_size = cxt->sector_size; |
| if (!cxt->io_size) |
| cxt->io_size = cxt->sector_size; |
| |
| DBG(CXT, ul_debugobj(cxt, "result: log/phy sector size: %ld/%ld", |
| cxt->sector_size, cxt->phy_sector_size)); |
| DBG(CXT, ul_debugobj(cxt, "result: fdisk/min/optimal io: %ld/%ld/%ld", |
| cxt->io_size, cxt->optimal_io_size, cxt->min_io_size)); |
| return 0; |
| } |
| |
| static int has_topology(struct fdisk_context *cxt) |
| { |
| /* |
| * Assume that the device provides topology info if |
| * optimal_io_size is set or alignment_offset is set or |
| * minimum_io_size is not power of 2. |
| */ |
| if (cxt && |
| (cxt->optimal_io_size || |
| cxt->alignment_offset || |
| !is_power_of_2(cxt->min_io_size))) |
| return 1; |
| return 0; |
| } |
| |
| /* |
| * The LBA of the first partition is based on the device geometry and topology. |
| * This offset is generic (and recommended) for all labels. |
| * |
| * Returns: 0 on error or number of logical sectors. |
| */ |
| static fdisk_sector_t topology_get_first_lba(struct fdisk_context *cxt) |
| { |
| fdisk_sector_t x = 0, res; |
| |
| if (!cxt) |
| return 0; |
| |
| if (!cxt->io_size) |
| fdisk_discover_topology(cxt); |
| |
| /* |
| * Align the begin of partitions to: |
| * |
| * a) topology |
| * a2) alignment offset |
| * a1) or physical sector (minimal_io_size, aka "grain") |
| * |
| * b) or default to 1MiB (2048 sectrors, Windows Vista default) |
| * |
| * c) or for very small devices use 1 phy.sector |
| */ |
| if (has_topology(cxt)) { |
| if (cxt->alignment_offset) |
| x = cxt->alignment_offset; |
| else if (cxt->io_size > 2048 * 512) |
| x = cxt->io_size; |
| } |
| /* default to 1MiB */ |
| if (!x) |
| x = 2048 * 512; |
| |
| res = x / cxt->sector_size; |
| |
| /* don't use huge offset on small devices */ |
| if (cxt->total_sectors <= res * 4) |
| res = cxt->phy_sector_size / cxt->sector_size; |
| |
| return res; |
| } |
| |
| static unsigned long topology_get_grain(struct fdisk_context *cxt) |
| { |
| unsigned long res; |
| |
| if (!cxt) |
| return 0; |
| |
| if (!cxt->io_size) |
| fdisk_discover_topology(cxt); |
| |
| res = cxt->io_size; |
| |
| /* use 1MiB grain always when possible */ |
| if (res < 2048 * 512) |
| res = 2048 * 512; |
| |
| /* don't use huge grain on small devices */ |
| if (cxt->total_sectors <= (res * 4 / cxt->sector_size)) |
| res = cxt->phy_sector_size; |
| |
| return res; |
| } |
| |
| /** |
| * fdisk_reset_alignment: |
| * @cxt: fdisk context |
| * |
| * Resets alignment setting to the default and label specific values. This |
| * function does not change device properties (I/O limits, geometry etc.). |
| * |
| * Returns: 0 on success, < 0 in case of error. |
| */ |
| int fdisk_reset_alignment(struct fdisk_context *cxt) |
| { |
| int rc = 0; |
| |
| if (!cxt) |
| return -EINVAL; |
| |
| DBG(CXT, ul_debugobj(cxt, "reseting alignment...")); |
| |
| /* default */ |
| cxt->grain = topology_get_grain(cxt); |
| cxt->first_lba = topology_get_first_lba(cxt); |
| cxt->last_lba = cxt->total_sectors - 1; |
| |
| /* overwrite default by label stuff */ |
| if (cxt->label && cxt->label->op->reset_alignment) |
| rc = cxt->label->op->reset_alignment(cxt); |
| |
| DBG(CXT, ul_debugobj(cxt, "alignment reseted to: " |
| "first LBA=%ju, last LBA=%ju, grain=%lu [rc=%d]", |
| (uintmax_t) cxt->first_lba, (uintmax_t) cxt->last_lba, |
| cxt->grain, rc)); |
| return rc; |
| } |
| |
| |
| fdisk_sector_t fdisk_scround(struct fdisk_context *cxt, fdisk_sector_t num) |
| { |
| fdisk_sector_t un = fdisk_get_units_per_sector(cxt); |
| return (num + un - 1) / un; |
| } |
| |
| fdisk_sector_t fdisk_cround(struct fdisk_context *cxt, fdisk_sector_t num) |
| { |
| return fdisk_use_cylinders(cxt) ? |
| (num / fdisk_get_units_per_sector(cxt)) + 1 : num; |
| } |
| |
| /** |
| * fdisk_reread_partition_table: |
| * @cxt: context |
| * |
| * Force *kernel* to re-read partition table on block devices. |
| * |
| * Returns: 0 on success, < 0 in case of error. |
| */ |
| int fdisk_reread_partition_table(struct fdisk_context *cxt) |
| { |
| int i; |
| struct stat statbuf; |
| |
| assert(cxt); |
| assert(cxt->dev_fd >= 0); |
| |
| i = fstat(cxt->dev_fd, &statbuf); |
| if (i == 0 && S_ISBLK(statbuf.st_mode)) { |
| sync(); |
| #ifdef BLKRRPART |
| fdisk_info(cxt, _("Calling ioctl() to re-read partition table.")); |
| i = ioctl(cxt->dev_fd, BLKRRPART); |
| #else |
| errno = ENOSYS; |
| i = 1; |
| #endif |
| } |
| |
| if (i) { |
| fdisk_warn(cxt, _("Re-reading the partition table failed.")); |
| fdisk_info(cxt, _( |
| "The kernel still uses the old table. The " |
| "new table will be used at the next reboot " |
| "or after you run partprobe(8) or kpartx(8).")); |
| return -errno; |
| } |
| |
| return 0; |
| } |