8.4 GConv API functions

Functions provided to higher modules

source file src/include/surprise/partition.h

• block_t getsize_struct(block_t)
  • Input pars: size of disk space covered by required changes in consequent call convert()
  • Output pars: none
  • Actions: computes size of the necessary structures for GConv conversion on given count of blocks
  • Memory alloc: none
  • Memory free: none
  • Return value: computed size
• int convert(size_t impnum, struct partition *imported, size_t expnum, struct partition *exported, size_t spcnum, struct space *free_space, int badblock_check, PROGRESS_PARAM, ERR_PARAM)
  • Input pars: number of imported partition, imported partitions, number of exported partitions, exported partitions, number of free spaces, free spaces, flag how to check on bad blocks (one of BADBLOCK_CHECK_*)
  • Output pars: none, fills few items in imported, exported partitions and free space
  • Actions: converts given beginning state described as imported partitions to final state desribed as exported partition with usage free space, this includes check on bad blocks (depends on parameter)
  • Memory alloc: none
  • Memory free: none
  • Return value: zero iff success
• int convert_move(struct partition *imported, struct partition *exported, int badblock_check, PROGRESS_PARAM, ERR_PARAM)
  • Input pars: imported and exported partition (guaranteed difference only in location), level of checking badblocks (one of BADBLOCK_CHECK_*)
  • Output pars: none
  • Action: moves partition from imported to exported location, possible move across devices, includes check on bad blocks
  • Memory alloc: none
  • Memory free: none
  • Return value: zero if success, negative if error
• int convert_create(size_t num, struct partition *exported, int badblock_check, PROGRESS_PARAM, ERR_PARAM)
  • Input pars: number of exported partitions, exported partitions, level of checking on bad blocks
  • Output pars: none
  • Actions: creates new empty described partitions
  • Memory alloc: none
  • Memory free: none
  • Return value: zero if success, negative if error
• int fill_zero(int fh, struct partition_base *base, PROGRESS_PARAM, ERR_PARAM)
• int fill_zero(int fh, struct partition_base *base, PROGRESS_PARAM, ERR_PARAM)
• int secure_erasure(int fh, struct partition_base *base, PROGRESS_PARAM, ERR_PARAM)
  • Input pars: device handle, interval of blocks on device
  • Output pars: none
  • Actions: fills blocks with zeroes
  • Memory alloc: none
  • Memory free: none
  • Return value: zero if success, negative if error
• int secure_erasure(int fh, struct partition_base *base, PROGRESS_PARAM, ERR_PARAM)
  • Input pars: device handle, interval of blocks on device
  • Output pars: none
  • Actions: securely erases data in blocks
  • Memory alloc: none
  • Memory free: none
  • Return value: zero if success, negative if error

Low-level functions for filesystem modules

These functions provide block interface for read/write operations on imported and also on exported partition and are intended for use in filesystem modules.

Note given position is always relative to the beginning of given partition and must be inside the partition. Provides block or byte oriented access, both accesses can be mixed. You should know that byte-oriented access is emulated by block oriented access.

• block_t bread(struct partition *part, const struct extent *blocks, void *buf, ERR_PARAM)
  • Input pars: source partition, extent of blocks
  • Output pars: buf - destination buffer
  • Actions: reads extent from partition into buffer
  • Memory alloc: none
  • Memory free: none
  • Return value: number of read blocks
• block_t bwrite(struct partition *part, const struct extent *blocks, const void *buf, ERR_PARAM)
  • Input pars: destination partition, extent of blocks, source buffer
  • Output pars: none
  • Actions: writes buffer to extent in partition
  • Memory alloc: none
  • Memory free: none
  • Return value: number of written blocks
• sec1off_t bread1(struct partition *part, sec1off_t index, sec1off_t count, void *buf, ERR_PARAM)
  • Input pars: source partition, first byte and number bytes to read
  • Output pars: buf - destination buffer
  • Actions: reads specified bytes from partition into buffer
  • Memory alloc: none
  • Memory free: none
  • Return value: number of read bytes
• sec1off_t bwrite1(struct partition *part, sec1off_t index, sec1off_t count, const void *buf, ERR_PARAM)
  • Input pars: destination partition, first byte and number bytes to write, source buffer
  • Output pars: none
  • Actions: writes buffer to specified bytes in partition
  • Memory alloc: none
  • Memory free: none
  • Return value: number of written bytes

API is found in file src/include/surprise/fs.h and implementation in src/libsurprise/gconv/brw.c