fdisk_align_lba ()

fdisk_sector_t
fdisk_align_lba (struct fdisk_context *cxt,
                 fdisk_sector_t lba,
                 int direction);

This function aligns lba to the "grain" (see fdisk_get_grain_size()). If the device uses alignment offset then the result is moved according the offset to be on the physical boundary.

fdisk_align_lba_in_range ()

fdisk_sector_t
fdisk_align_lba_in_range (struct fdisk_context *cxt,
                          fdisk_sector_t lba,
                          fdisk_sector_t start,
                          fdisk_sector_t stop);

Align lba , the result has to be between start and stop

fdisk_has_user_device_properties ()

int
fdisk_has_user_device_properties (struct fdisk_context *cxt);

fdisk_lba_is_phy_aligned ()

int
fdisk_lba_is_phy_aligned (struct fdisk_context *cxt,
                          fdisk_sector_t lba);

Check if the lba is aligned to physical sector boundary.

fdisk_override_geometry ()

int
fdisk_override_geometry (struct fdisk_context *cxt,
                         unsigned int cylinders,
                         unsigned int heads,
                         unsigned int 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 reset.

fdisk_reset_alignment ()

int
fdisk_reset_alignment (struct fdisk_context *cxt);

Resets alignment setting to the default and label specific values. This function does not change device properties (I/O limits, geometry etc.).

fdisk_reset_device_properties ()

int
fdisk_reset_device_properties (struct fdisk_context *cxt);

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.

fdisk_save_user_geometry ()

int
fdisk_save_user_geometry (struct fdisk_context *cxt,
                          unsigned int cylinders,
                          unsigned int heads,
                          unsigned int sectors);

Save user defined geometry to use it for partitioning.

The user properties are applied by fdisk_assign_device() or fdisk_reset_device_properties().

fdisk_save_user_grain ()

int
fdisk_save_user_grain (struct fdisk_context *cxt,
                       unsigned long  grain);

Save user define grain size. The size is used to align partitions.

The default is 1MiB (or optimal I/O size if greater than 1MiB). It's strongly recommended to use the default.

The smallest possible granularity for partitioning is physical sector size (or minimal I/O size; the bigger number win). If the user's grain size is too small then the smallest possible granularity is used. It means fdisk_save_user_grain(cxt, 512) forces libfdisk to use grain as small as possible.

The setting is applied by fdisk_assign_device() or fdisk_reset_device_properties().

fdisk_save_user_sector_size ()

int
fdisk_save_user_sector_size (struct fdisk_context *cxt,
                             unsigned int phy,
                             unsigned int log);

Save user defined sector sizes to use it for partitioning.

The user properties are applied by fdisk_assign_device() or fdisk_reset_device_properties().

FDISK_ALIGN_DOWN

#define FDISK_ALIGN_DOWN 2

FDISK_ALIGN_NEAREST

#define FDISK_ALIGN_NEAREST 3

FDISK_ALIGN_UP

#define FDISK_ALIGN_UP		1

fdisk_sector_t

typedef uint64_t fdisk_sector_t;

LBA addresses type