1 \input texinfo @c -*-texinfo-*-
3 @setfilename libext2fs.info
4 @settitle The EXT2FS Library (version 1.42.3)
6 @comment %**end of header
9 @dircategory Development
11 * libext2fs: (libext2fs). The EXT2FS library.
21 @c Note: the edition number is listed in *three* places; please update
22 @c all three. Also, update the month and year where appropriate.
24 @c ==> Update edition number for settitle and subtitle, and in the
25 @c ==> following paragraph; update date, too.
29 This file documents the ext2fs library, a library for manipulating the
32 Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
33 2006, 2007, 2008, 2009, 2010, 2011, 2012 by Theodore Ts'o
35 Permission is granted to make and distribute verbatim copies of
36 this manual provided the copyright notice and this permission notice
37 are preserved on all copies.
40 Permission is granted to process this file through TeX and print the
41 results, provided the printed document carries copying permission
42 notice identical to this one except for the removal of this paragraph
43 (this paragraph not being relevant to the printed manual).
46 Permission is granted to copy and distribute modified versions of this
47 manual under the conditions for verbatim copying, provided that the entire
48 resulting derived work is distributed under the terms of a permission
49 notice identical to this one.
51 Permission is granted to copy and distribute translations of this manual
52 into another language, under the above conditions for modified versions,
53 except that this permission notice may be stated in a translation approved
59 @c use the new format for titles
61 @title The EXT2FS Library
62 @subtitle The EXT2FS Library
63 @subtitle Version 1.42.3
66 @author by Theodore Ts'o
68 @c Include the Distribution inside the titlepage so
69 @c that headings are turned off.
74 \global\baselineskip=13pt
78 @vskip 0pt plus 1filll
79 Copyright @copyright{} 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
80 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Theodore Ts'o
84 Permission is granted to make and distribute verbatim copies of
85 this manual provided the copyright notice and this permission notice
86 are preserved on all copies.
88 Permission is granted to copy and distribute modified versions of this
89 manual under the conditions for verbatim copying, provided that the entire
90 resulting derived work is distributed under the terms of a permission
91 notice identical to this one.
93 Permission is granted to copy and distribute translations of this manual
94 into another language, under the above conditions for modified versions,
95 except that this permission notice may be stated in a translation approved
101 @node Top, Introduction to the EXT2FS Library, (dir), (dir)
103 @top The EXT2FS Library
105 This manual documents the EXT2FS Library, version 1.42.3.
110 * Introduction to the EXT2FS Library::
111 * EXT2FS Library Functions::
116 @c ----------------------------------------------------------------------
118 @node Introduction to the EXT2FS Library, EXT2FS Library Functions, Top, Top
119 @comment node-name, next, previous, up
120 @chapter Introduction to the EXT2FS Library
122 The EXT2FS library is designed to allow user-level programs to
123 manipulate an ext2 filesystem.
125 @node EXT2FS Library Functions, Concept Index, Introduction to the EXT2FS Library, Top
126 @comment node-name, next, previous, up
127 @chapter EXT2FS Library Functions
130 * Filesystem-level functions::
131 * File I/O Functions::
133 * Directory functions::
135 * EXT2 data abstractions::
136 * Byte-swapping functions::
140 @c ----------------------------------------------------------------------
142 @node Filesystem-level functions, File I/O Functions, EXT2FS Library Functions, EXT2FS Library Functions
143 @comment node-name, next, previous, up
144 @section Filesystem-level functions
146 The following functions operate on a filesystem handle. Most EXT2FS
147 Library functions require a filesystem handle as their first argument.
148 There are two functions which create a filesystem handle,
149 @code{ext2fs_open} and @code{ext2fs_initialize}.
151 The filesystem can also be closed using @code{ext2fs_close}, and any
152 changes to the superblock and group descripts can be written out to disk
153 using @code{ext2fs_flush}.
156 * Opening an ext2 filesystem::
157 * Closing and flushing out changes::
158 * Initializing a filesystem::
159 * Filesystem flag functions::
162 @c ----------------------------------------------------------------------
164 @node Opening an ext2 filesystem, Closing and flushing out changes, Filesystem-level functions, Filesystem-level functions
165 @comment node-name, next, previous, up
166 @subsection Opening an ext2 filesystem
168 Most libext2fs functions take a filesystem handle of type
169 @code{ext2_filsys}. A filesystem handle is created either by opening
170 an existing function using @code{ext2fs_open}, or by initializing a new
171 filesystem using @code{ext2fs_initialize}.
173 @deftypefun errcode_t ext2fs_open (const char *@var{name}, int @var{flags}, int @var{superblock}, int @var{block_size}, io_manager @var{manager}, ext2_filsys *@var{ret_fs})
175 Opens a filesystem named @var{name}, using the the io_manager
176 @var{manager} to define the input/output routines needed to read and
177 write the filesystem. In the case of the @code{unix_io} io_manager,
178 @var{name} is interpreted as the Unix filename of the filesystem image.
179 This is often a device file, such as @file{/dev/hda1}.
181 The @var{superblock} parameter specifies the block number of the
182 superblock which should be used when opening the filesystem.
183 If @var{superblock} is zero, @code{ext2fs_open} will use the primary
184 superblock located at offset 1024 bytes from the start of the filesystem
187 The @var{block_size} parameter specifies the block size used by the
188 filesystem. Normally this is determined automatically from the
189 filesystem uperblock. If @var{block_size} is non-zero, it must match
190 the block size found in the superblock, or the error
191 @code{EXT2_ET_UNEXPECTED_BLOCK_SIZE} will be returned. The
192 @var{block_size} parameter is also used to help fund the superblock when
193 @var{superblock} is non-zero.
195 The @var{flags} argument contains a bitmask of flags which control how
196 the filesystem open should be handled.
200 Open the filesystem for reading and writing. Without this flag, the
201 filesystem is opened for reading only.
203 @item EXT2_FLAG_FORCE
204 Open the filesystem regardless of the feature sets listed in the
210 @c ----------------------------------------------------------------------
212 @node Closing and flushing out changes, Initializing a filesystem, Opening an ext2 filesystem, Filesystem-level functions
213 @comment node-name, next, previous, up
214 @subsection Closing and flushing out changes
216 @deftypefun errcode_t ext2fs_flush (ext2_filsys @var{fs})
218 Write any changes to the high-level filesystem data structures in the
219 @var{fs} filesystem. The following data structures will be written out:
222 @item The filesystem superblock
223 @item The filesystem group descriptors
224 @item The filesystem bitmaps, if read in via @code{ext2fs_read_bitmaps}.
229 @deftypefun void ext2fs_free (ext2_filsys @var{fs})
231 Close the io_manager abstraction for @var{fs} and release all memory
232 associated with the filesystem handle.
235 @deftypefun errcode_t ext2fs_close (ext2_filsys @var{fs})
237 Flush out any changes to the high-level filesystem data structures using
238 @code{ext2fs_flush} if the filesystem is marked dirty; then close and
239 free the filesystem using @code{ext2fs_free}.
243 @c ----------------------------------------------------------------------
245 @node Initializing a filesystem, Filesystem flag functions, Closing and flushing out changes, Filesystem-level functions
246 @comment node-name, next, previous, up
247 @subsection Initializing a filesystem
249 An ext2 filesystem is initializing by the @code{mke2fs} program. The
250 two functions described here, @code{ext2fs_initialize} and
251 @code{ext2fs_allocate_tables} do much of the initial work for setting up
252 a filesystem. However, they don't do the whole job. @code{mke2fs}
253 calls @code{ext2fs_initialize} to set up the filesystem superblock, and
254 calls @code{ext2fs_allocate_tables} to allocate space for the inode
255 table, and the inode and block bitmaps. In addition, @code{mke2fs} must
256 also initialize the inode tables by clearing them with zeros, create the
257 root and lost+found directories, and reserve the reserved inodes.
259 @deftypefun errcode_t ext2fs_initialize (const char *@var{name}, int @var{flags}, struct ext2_super_block *@var{param}, io_manager @var{manager}, ext2_filsys *@var{ret_fs})
261 This function is used by the @code{mke2fs} program to initialize a
262 filesystem. The @code{ext2fs_initialize} function creates a filesystem
263 handle which is returned in @var{ret_fs} that has been properly setup
264 for a filesystem to be located in @var{name}, using the io_manager
265 @var{manager}. The prototype superblock in @var{param} is used to
266 supply parameters such as the number of blocks in the filesystem, the
269 The @code{ext2fs_initialize} function does not actually do any I/O; that
270 will be done when the application program calls @code{ext2fs_close} or
271 @code{ext2fs_flush}. Also, this function only initializes the
272 superblock and group descriptor structures. It does not create the
273 inode table or the root directory. This must be done by the calling
274 application, such as @code{mke2fs}.
276 The following values may be set in the @var{param} prototype superblock;
277 if a value of 0 is found in a field, @code{ext2fs_initialize} will use a
278 default value. The calling application should zero out the prototype
279 entire superblock, and then fill in any appropriate values.
284 The number of blocks in the filesystem. This parameter is mandatory and
285 must be set by the calling application.
288 The number of inodes in the filesystem. The
289 default value is determined by calculating the size of the filesystem,
290 and creating one inode for every 4096 bytes.
292 @item s_r_blocks_count
293 The number of blocks which should be reserved for the superuser. The
294 default value is zero blocks.
296 @item s_log_block_size
297 The blocksize of the filesystem. Valid values are 0 (1024 bytes), 1
298 (2048 bytes), or 2 (4096 bytes). The default blocksize is 1024 bytes.
300 @item s_log_frag_size
301 The size of fragments. The ext2 filesystem does not support fragments
302 (and may never support fragments). Currently this field must be the
303 same as @code{s_log_block_size}.
305 @item s_first_data_block
306 The first data block for the filesystem. For filesystem with a
307 blocksize of 1024 bytes, this value must be at least 1, since the
308 superblock is located in block number 1. For filesystems with larger
309 blocksizes, the superblock is still located at an offset of 1024 bytes,
310 so the superblock is located in block number 0. By default, this value
311 is set to 1 for filesystems with a block size of 1024 bytes, or 0 for
312 filesystems with larger blocksizes.
314 @item s_max_mnt_count
315 This field defines the number of times that the filesystem can be
316 mounted before it should be checked using @code{e2fsck}. When
317 @code{e2fsck} is run without the @samp{-f} option, @code{e2fsck} will
318 skip the filesystem check if the number of times that the filesystem has
319 been mounted is less than @code{s_max_mnt_count} and if the interval
320 between the last time a filesystem check was performed and the current
321 time is less than @code{s_checkinterval} (see below). The default value
322 of @code{s_max_mnt_count} is 20.
324 @item s_checkinterval
325 This field defines the minimal interval between filesystem checks. See
326 the previous entry for a discussion of how this field is used by
327 @code{e2fsck}. The default value of this field is 180 days (six
331 This field defines the behavior which should be used by the kernel of
332 errors are detected in the filesystem. Possible values include:
335 @item EXT2_ERRORS_CONTINUE
336 Continue execution when errors are detected.
339 Remount the filesystem read-only.
341 @item EXT2_ERRORS_PANIC
346 The default behavior is @samp{EXT2_ERRORS_CONTINUE}.
352 @deftypefun errcode_t ext2fs_allocate_tables (ext2_filsys @var{fs})
353 Allocate space for the inode table and the block and inode bitmaps. The
354 inode tables and block and inode bitmaps aren't actually initialized;
355 this function just allocates the space for them.
358 @c ----------------------------------------------------------------------
360 @node Filesystem flag functions, , Initializing a filesystem, Filesystem-level functions
361 @comment node-name, next, previous, up
362 @subsection Filesystem flag functions
364 The filesystem handle has a number of flags which can be manipulated
365 using the following function. Some of these flags affect how the
366 libext2fs filesystem behaves; others are provided solely for the
367 application's convenience.
369 @deftypefun void ext2fs_mark_changed (ext2_filsys @var{fs})
370 @deftypefunx int ext2fs_test_changed (ext2_filsys @var{fs})
371 This flag indicates whether or not the filesystem has been changed.
372 It is not used by the ext2fs library.
375 @deftypefun void ext2fs_mark_super_dirty (ext2_filsys @var{fs})
376 Mark the filesystem @var{fs} as being dirty; this will cause
377 the superblock information to be flushed out when @code{ext2fs_close} is
378 called. @code{ext2fs_mark_super_dirty} will also set the filesystem
379 changed flag. The dirty flag is automatically cleared by
380 @code{ext2fs_flush} when the superblock is written to disk.
383 @deftypefun void ext2fs_mark_valid (ext2_filsys @var{fs})
384 @deftypefunx void ext2fs_unmark_valid (ext2_filsys @var{fs})
385 @deftypefunx int ext2fs_test_valid (ext2_filsys @var{fs})
386 This flag indicates whether or not the filesystem is free of errors.
387 It is not used by libext2fs, and is solely for the application's
391 @deftypefun void ext2fs_mark_ib_dirty (ext2_filsys @var{fs})
392 @deftypefunx void ext2fs_mark_bb_dirty (ext2_filsys @var{fs})
393 @deftypefunx int ext2fs_test_ib_dirty (ext2_filsys @var{fs})
394 @deftypefunx int ext2fs_test_bb_dirty (ext2_filsys @var{fs})
395 These flags indicate whether or not the inode or block bitmaps have been
396 modified. If the flag is set, it will cause the appropriate bitmap
397 to be written when the filesystem is closed or flushed.
400 @c ----------------------------------------------------------------------
402 @node File I/O Functions, Inode Functions, Filesystem-level functions, EXT2FS Library Functions
403 @comment node-name, next, previous, up
404 @section File I/O Functions
406 The following functions provide a convenient abstraction to read or
407 write a file in an filesystem. The interface is similar in spirit to
408 the Linux/POSIX file I/O system calls.
411 * File handle manipulation::
412 * Reading and writing data::
413 * Changing the file offset ::
414 * Getting the file size::
417 @c ----------------------------------------------------------------------
419 @node File handle manipulation, Reading and writing data, File I/O Functions, File I/O Functions
420 @comment node-name, next, previous, up
421 @subsection File handle manipulation
423 The file handle functions much like a file descriptor in the Linux/POSIX
424 file I/O system calls. Unlike the Linux/POSIX system calls, files are
425 opened via inode numbers instead of via pathnames. To resolve a
426 pathname to an inode number, use the function @code{ext2fs_namei} or to
427 create a new file, use @code{ext2fs_new_inode} and @code{ext2fs_link}.
429 @deftypefun errcode_t ext2fs_file_open2 (ext2_filsys @var{fs}, ext2_ino_t @var{ino}, struct ext2_inode *@var{inode}, int @var{flags}, ext2_file_t *@var{ret})
430 @deftypefunx errcode_t ext2fs_file_open (ext2_filsys @var{fs}, ext2_ino_t @var{ino}, int @var{flags}, ext2_file_t *@var{ret})
432 Opens a file identified by inode number @var{ino} in filesystem @var{fs}
433 and returns a file handle in @var{ret}. If an inode structure is
434 provided in @var{inode}, then it is used instead of reading the inode
437 The @var{flags} argument contains a bitmask of flags which control how
438 the file should be opened.
441 @item EXT2_FILE_WRITE
442 Open the file for reading and writing. Without this flag, the file is
443 opened for writing only.
445 @item EXT2_FILE_CREATE
446 Create the file if it is not already present.
451 @deftypefun ext2_filsys ext2fs_file_get_fs (ext2_file_t @var{file})
452 Return the filesystem handle where the open file @var{file} was opened.
455 @deftypefun errcode_t ext2fs_file_close (ext2_file_t @var{file})
456 Close the file handle @var{file}.
459 @deftypefun errcode_t ext2fs_file_flush (ext2_file_t @var{file})
460 Force any data written via @code{ext2fs_file_write} to disk.
463 @c ----------------------------------------------------------------------
465 @node Reading and writing data, Changing the file offset , File handle manipulation, File I/O Functions
466 @comment node-name, next, previous, up
467 @subsection Reading and writing data
469 @deftypefun errcode_t ext2fs_file_read (ext2_file_t @var{file}, void *@var{buf}, unsigned int @var{wanted}, unsigned int *@var{got})
470 Read @var{wanted} bytes of data from @var{file} store it in the buffer
471 @var{buf}. The number of bytes that was actually read is returned
475 @deftypefun errcode_t ext2fs_file_write (ext2_file_t @var{file}, const void *@var{buf}, unsigned int @var{nbytes}, unsigned int *@var{written})
476 Write @var{wanted} bytes of data from the buffer @var{buf} to the
477 current file position of @var{file}. The number of bytes that was
478 actually written is returned via @var{got}.
481 @c ----------------------------------------------------------------------
483 @node Changing the file offset , Getting the file size, Reading and writing data, File I/O Functions
484 @comment node-name, next, previous, up
485 @subsection Changing the file offset
487 @deftypefun errcode_t ext2fs_file_llseek (ext2_file_t @var{file}, __u64 @var{offset}, int @var{whence}, __u64 *@var{ret_pos})
488 @deftypefunx errcode_t ext2fs_file_lseek (ext2_file_t @var{file}, ext2_off_t @var{offset}, int @var{whence}, ext2_off_t *@var{ret_pos})
489 Change the current file position of @var{file} according to the
490 directive @var{whence} as follows:
494 The file position is set to @var{offset} bytes from the beginning of the
498 The file position set to its current location plus @var{offset} bytes.
501 The file position is set to the size of the file plus @var{offset}
505 The current offset is returned via @var{ret_pos}.
508 @c ----------------------------------------------------------------------
510 @node Getting the file size, , Changing the file offset , File I/O Functions
511 @comment node-name, next, previous, up
512 @subsection Getting the file size
514 @deftypefun errcode_t ext2fs_file_get_lsize (ext2_file_t @var{file}, __u64 *@var{ret_size})
515 Return the size of the file @var{file} in @var{ret_size}.
518 @deftypefun ext2_off_t ext2fs_file_get_size (ext2_file_t @var{file})
519 Return the size of the file @var{file}.
522 @c ----------------------------------------------------------------------
524 @node Inode Functions, Directory functions, File I/O Functions, EXT2FS Library Functions
525 @comment node-name, next, previous, up
526 @section Inode Functions
529 * Reading and writing inodes::
530 * Iterating over inodes in a filesystem::
531 * Iterating over blocks in an inode::
532 * Inode Convenience Functions::
535 @c ----------------------------------------------------------------------
537 @node Reading and writing inodes, Iterating over inodes in a filesystem, Inode Functions, Inode Functions
538 @comment node-name, next, previous, up
539 @subsection Reading and writing inodes
541 @deftypefun errcode_t ext2fs_read_inode (ext2_filsys @var{fs}, ext2_ino_t @var{ino}, struct ext2_inode *@var{inode})
542 Read the inode number @var{ino} into @var{inode}.
545 @deftypefun errcode_t ext2fs_write_inode (ext2_filsys @var{fs}, ext2_ino_t @var{ino}, struct ext2_inode *@var{inode})
546 Write @var{inode} to inode @var{ino}.
550 @c ----------------------------------------------------------------------
552 @node Iterating over inodes in a filesystem, Iterating over blocks in an inode, Reading and writing inodes, Inode Functions
553 @comment node-name, next, previous, up
554 @subsection Iterating over inodes in a filesystem
556 The inode_scan abstraction is useful for iterating over all the inodes
559 @deftypefun errcode_t ext2fs_open_inode_scan (ext2_filsys @var{fs}, int @var{buffer_blocks}, ext2_inode_scan *@var{scan})
560 Initialize the iteration variable @var{scan}. This variable is used by
561 @code{ext2fs_get_next_inode}. The @var{buffer_blocks} parameter
562 controls how many blocks of the inode table are read in at a time. A
563 large number of blocks requires more memory, but reduces the overhead in
564 seeking and reading from the disk. If @var{buffer_blocks} is zero, a
565 suitable default value will be used.
568 @deftypefun void ext2fs_close_inode_scan (ext2_inode_scan @var{scan})
569 Release the memory associated with @var{scan} and invalidate it.
572 @deftypefun errcode_t ext2fs_get_next_inode (ext2_inode_scan @var{scan}, ext2_ino_t *@var{ino}, struct ext2_inode *@var{inode})
574 This function returns the next inode from the filesystem; the inode
575 number of the inode is stored in @var{ino}, and the inode is stored in
578 If the inode is located in a block that has been marked as bad,
579 @code{ext2fs_get_next_inode} will return the error
580 @code{EXT2_ET_BAD_BLOCK_IN_INODE_TABLE}.
583 @deftypefun errcode_t ext2fs_inode_scan_goto_blockgroup (ext2_inode_scan @var{scan}, int @var{group})
584 Start the inode scan at a particular ext2 blockgroup, @var{group}.
585 This function may be safely called at any time while @var{scan} is valid.
588 @deftypefun void ext2fs_set_inode_callback (ext2_inode_scan @var{scan}, errcode_t (*done_group)(ext2_filsys @var{fs}, ext2_inode_scan @var{scan}, dgrp_t @var{group}, void * @var{private}), void *@var{done_group_data})
589 Register a callback function which will be called by
590 @code{ext2_get_next_inode} when all of the inodes in a block group have
594 @deftypefun int ext2fs_inode_scan_flags (ext2_inode_scan @var{scan}, int @var{set_flags}, int @var{clear_flags})
596 Set the scan_flags @var{set_flags} and clear the scan_flags @var{clear_flags}.
597 The following flags can be set using this interface:
601 @item EXT2_SF_SKIP_MISSING_ITABLE
602 When a block group is missing an inode table, skip it. If this flag is
603 not set @code{ext2fs_get_next_inode} will return the error
604 EXT2_ET_MISSING_INODE_TABLE.
610 @c ----------------------------------------------------------------------
612 @node Iterating over blocks in an inode, Inode Convenience Functions, Iterating over inodes in a filesystem, Inode Functions
613 @comment node-name, next, previous, up
614 @subsection Iterating over blocks in an inode
616 @deftypefun errcode_t ext2fs_block_iterate (ext2_filsys @var{fs}, ext2_ino_t @var{ino}, int @var{flags}, char *block_buf, int (*func)(ext2_filsys @var{fs}, blk_t *@var{blocknr}, int @var{blockcnt}, void *@var{private}), void *@var{private})
618 Iterate over all of the blocks in inode number @var{ino} in filesystem
619 @var{fs}, by calling the function @var{func} for each block in the
620 inode. The @var{block_buf} parameter should either be NULL, or if the
621 @code{ext2fs_block_iterate} function is called repeatedly, the overhead
622 of allocating and freeing scratch memory can be avoided by passing a
623 pointer to a scratch buffer which must be at least as big as three times the
624 filesystem's blocksize.
626 The @var{flags} parameter controls how the iterator will function:
630 @item BLOCK_FLAG_HOLE
631 This flag indiciates that the interator function should be called on
632 blocks where the block number is zero (also known as ``holes''.) It is
633 also known as BLOCK_FLAG_APPEND, since it is also used by functions
634 such as ext2fs_expand_dir() to add a new block to an inode.
636 @item BLOCK_FLAG_DEPTH_TRAVERSE
637 This flag indicates that the iterator function for the
638 indirect, doubly indirect, etc. blocks should be called after all
639 of the blocks containined in the indirect blocks are processed.
640 This is useful if you are going to be deallocating blocks from an
643 @item BLOCK_FLAG_DATA_ONLY
644 This flag indicates that the iterator function should be
645 called for data blocks only.
649 The callback function @var{func} is called with a number of parameters;
650 the @var{fs} and @var{private} parameters are self-explanatory, and
651 their values are taken from the parameters to
652 @code{ext2fs_block_iterate}. (The @var{private} data structure is
653 generally used by callers to @code{ext2fs_block_iterate} so that some
654 private data structure can be passed to the callback function. The
655 @var{blockcnt} parameter, if non-negative, indicates the logical block
656 number of a data block in the inode. If @var{blockcnt} is less than
657 zero, then @var{func} was called on a metadata block, and @var{blockcnt}
658 will be one of the following values: BLOCK_COUNT_IND, BLOCK_COUNT_DIND,
659 BLOCK_COUNT_TIND, or BLOCK_COUNT_TRANSLATOR. The @var{blocknr} is a
660 pointer to the inode or indirect block entry listing physical block
661 number. The callback function may modify the physical block number, if
662 it returns the @var{BLOCK_CHANGED} flag.
665 The callback function @var{func} returns a result code which is composed of
666 the logical OR of the following flags:
672 This flag indicates that callback function has modified the physical
673 block number pointed to by @var{blocknr}.
677 This flag requests that @code{ext2fs_block_iterate} to stop immediately
678 and return to the caller.
684 @deftypefun errcode_t ext2fs_block_iterate2 (ext2_filsys @var{fs}, ext2_ino_t @var{ino}, int @var{flags}, char *@var{block}_buf, int (*func)(ext2_filsys @var{fs}, blk_t *@var{blocknr}, e2_blkcnt_t @var{blockcnt}, blk_t @var{ref_blk}, int @var{ref_offset}, void *@var{private}), void *@var{private})
686 This function is much like @code{ext2fs_block_iterate}, except that the
687 @var{blockcnt} type is a 64-bit signed quantity, to support larger
688 files, and the addition of the @var{ref_blk} and @var{ref_offset}
689 arguments passed to the callback function, which identify the location
690 of the physical block pointed to by pointer @var{blocknr}. If
691 @var{ref_blk} is zero, then @var{ref_offset} contains the offset into
692 the @code{i_blocks} array. If @var{ref_blk} is non-zero, then the physical
693 block location is contained inside an indirect block group, and
694 @var{ref_offset} contains the offset into the indirect block.
698 @c ----------------------------------------------------------------------
700 @node Inode Convenience Functions, , Iterating over blocks in an inode, Inode Functions
701 @comment node-name, next, previous, up
702 @subsection Convenience functions for Inodes
704 @deftypefun errcode_t ext2fs_get_blocks (ext2_filsys @var{fs}, ext2_ino_t @var{ino}, blk_t *@var{blocks})
706 Returns an array of blocks corresponding to the direct,
707 indirect, doubly indirect, and triply indirect blocks as stored in the
711 @deftypefun errcode_t ext2fs_check_directory (ext2_filsys @var{fs}, ext2_ino_t @var{ino})
712 Returns 0 if @var{ino} is a directory, and @code{ENOTDIR} if it is not.
715 @deftypefun int ext2fs_inode_has_valid_blocks (struct ext2_inode *@var{inode})
717 Returns 1 if the inode's block entries actually valid block entries, and
718 0 if not. Inodes which represent devices and fast symbolic links do not
719 contain valid block entries.
722 @c ----------------------------------------------------------------------
724 @node Directory functions, Bitmap Functions, Inode Functions, EXT2FS Library Functions
725 @comment node-name, next, previous, up
726 @section Directory functions
729 * Directory block functions::
730 * Iterating over a directory::
731 * Creating and expanding directories::
732 * Creating and removing directory entries::
733 * Looking up filenames::
734 * Translating inode numbers to filenames::
737 @c ----------------------------------------------------------------------
739 @node Directory block functions, Iterating over a directory, Directory functions, Directory functions
740 @comment node-name, next, previous, up
741 @subsection Directory block functions
743 @deftypefun errcode_t ext2fs_read_dir_block (ext2_filsys @var{fs}, blk_t @var{block}, void *@var{buf})
745 This function reads a directory block, performing any necessary
746 byte swapping if necessary.
749 @deftypefun errcode_t ext2fs_write_dir_block (ext2_filsys @var{fs}, blk_t @var{block}, void *@var{buf})
751 This function writes a directory block, performing any necessary
752 byte swapping if necessary.
755 @deftypefun errcode_t ext2fs_new_dir_block (ext2_filsys @var{fs}, ext2_ino_t @var{dir_ino}, ext2_ino_t @var{parent_ino}, char **@var{block})
757 This function creates a new directory block in @var{block}. If
758 @var{dir_ino} is non-zero, then @var{dir_info} and @var{parent_ino} is used
759 to initialize directory entries for @file{.} and @file{..}, respectively.
762 @c ----------------------------------------------------------------------
764 @node Iterating over a directory, Creating and expanding directories, Directory block functions, Directory functions
765 @comment node-name, next, previous, up
766 @subsection Iterating over a directory
768 @deftypefun errcode_t ext2fs_dir_iterate (ext2_filsys @var{fs}, ext2_ino_t @var{dir}, int @var{flags}, char *@var{block_buf}, int (*@var{func})(struct ext2_dir_entry *@var{dirent}, int @var{offset}, int @var{blocksize}, char *@var{buf}, void *@var{private}), void *@var{private})
770 This function interates over all of the directory entries in the
771 directory @var{dir}, calling the callback function @var{func} for each
772 directory entry in the directory. The @var{block_buf} parameter should
773 either be NULL, or if the @code{ext2fs_dir_iterate} function is
774 called repeatedly, the overhead of allocating and freeing
775 scratch memory can be avoided by passing a pointer to a scratch buffer
776 which must be at least as big as the filesystem's blocksize.
778 The @var{flags} parameter controls how the iterator will function:
782 @item DIRENT_FLAG_INCLUDE_EMPTY
784 This flag indicates that the callback function should be called even
785 for deleted or empty directory entries.
791 @c ----------------------------------------------------------------------
793 @node Creating and expanding directories, Creating and removing directory entries, Iterating over a directory, Directory functions
794 @comment node-name, next, previous, up
795 @subsection Creating and expanding directories
797 @deftypefun errcode_t ext2fs_mkdir (ext2_filsys @var{fs}, ext2_ino_t @var{parent}, ext2_ino_t @var{inum}, const char *@var{name})
799 This function creates a new directory. If @var{inum} is zero, then a
800 new inode will be allocated; otherwise, the directory will be created in
801 the inode specified by @var{inum}. If @var{name} specifies the name of
802 the new directory; if it is non-NULL, then the new directory will be
803 linked into the parent directory @var{parent}.
806 @deftypefun errcode_t ext2fs_expand_dir (ext2_filsys @var{fs}, ext2_ino_t @var{dir})
808 This function adds a new empty directory block and appends it to
809 the directory @var{dir}. This allows functions such as
810 @code{ext2fs_link} to add new directory entries to a directory which is full.
814 @c ----------------------------------------------------------------------
816 @node Creating and removing directory entries, Looking up filenames, Creating and expanding directories, Directory functions
817 @comment node-name, next, previous, up
818 @subsection Creating and removing directory entries
820 @deftypefun errcode_t ext2fs_link (ext2_filsys @var{fs}, ext2_ino_t @var{dir}, const char *@var{name}, ext2_ino_t @var{ino}, int flags)
822 This function adds a new directory entry to the directory @var{dir},
823 with @var{name} and @var{ino} specifying the name and inode number in
824 the directory entry, respectively.
826 The low 3 bits of the flags field is used to specify the file type of
827 inode: (No other flags are currently defined.)
831 @item EXT2_FT_UNKNOWN
833 The file type is unknown.
835 @item EXT2_FT_REG_FILE
837 The file type is a normal file.
841 The file type is a directory.
845 The file type is a character device.
849 The file type is a block device.
853 The file type is a named pipe.
857 The file type is a unix domain socket.
859 @item EXT2_FT_SYMLINK
861 The file type is a symbolic link.
866 @deftypefun errcode_t ext2fs_unlink (ext2_filsys @var{fs}, ext2_ino_t @var{dir}, const char *@var{name}, ext2_ino_t @var{ino}, int @var{flags})
868 This function removes a directory entry from @var{dir}.
869 The directory entry to be removed is the first one which is
870 matched by @var{name} and @var{ino}. If @var{name} is non-NULL,
871 the directory entry's name must match @var{name}. If @var{ino} is
872 non-zero, the directory entry's inode number must match @var{ino}.
873 No flags are currently defined for @code{ext2fs_unlink}; callers should
874 pass in zero to this parameter.
878 @c ----------------------------------------------------------------------
880 @node Looking up filenames, Translating inode numbers to filenames, Creating and removing directory entries, Directory functions
881 @comment node-name, next, previous, up
882 @subsection Looking up filenames
884 @deftypefun errcode_t ext2fs_lookup (ext2_filsys @var{fs}, ext2_ino_t @var{dir}, const char *@var{name}, int @var{namelen}, char *@var{buf}, ext2_ino_t *@var{inode})
887 @deftypefun errcode_t ext2fs_namei (ext2_filsys @var{fs}, ext2_ino_t @var{root}, ext2_ino_t @var{cwd}, const char *@var{name}, ext2_ino_t *@var{inode})
890 @deftypefun errcode_t ext2fs_namei_follow (ext2_filsys @var{fs}, ext2_ino_t @var{root}, ext2_ino_t @var{cwd}, const char *@var{name}, ext2_ino_t *@var{inode})
893 @deftypefun errcode_t ext2fs_follow_link (ext2_filsys @var{fs}, ext2_ino_t @var{root}, ext2_ino_t @var{cwd}, ext2_ino_t @var{inode}, ext2_ino_t *@var{res}_inode)
896 @c ----------------------------------------------------------------------
898 @node Translating inode numbers to filenames, , Looking up filenames, Directory functions
899 @comment node-name, next, previous, up
900 @subsection Translating inode numbers to filenames
902 @deftypefun errcode_t ext2fs_get_pathname (ext2_filsys @var{fs}, ext2_ino_t @var{dir}, ext2_ino_t @var{ino}, char **@var{name})
906 @c ----------------------------------------------------------------------
908 @node Bitmap Functions, EXT2 data abstractions, Directory functions, EXT2FS Library Functions
909 @comment node-name, next, previous, up
910 @section Bitmap Functions
913 * Reading and Writing Bitmaps::
914 * Allocating Bitmaps::
916 * Bitmap Operations::
917 * Comparing bitmaps::
918 * Modifying Bitmaps::
923 @c ----------------------------------------------------------------------
925 @node Reading and Writing Bitmaps, Allocating Bitmaps, Bitmap Functions, Bitmap Functions
926 @comment node-name, next, previous, up
927 @subsection Reading and Writing Bitmaps
929 @deftypefun errcode_t ext2fs_write_inode_bitmap (ext2_filsys @var{fs})
932 @deftypefun errcode_t ext2fs_write_block_bitmap (ext2_filsys @var{fs})
935 @deftypefun errcode_t ext2fs_read_inode_bitmap (ext2_filsys @var{fs})
938 @deftypefun errcode_t ext2fs_read_block_bitmap (ext2_filsys @var{fs})
941 @deftypefun errcode_t ext2fs_read_bitmaps (ext2_filsys @var{fs})
944 @deftypefun errcode_t ext2fs_write_bitmaps (ext2_filsys @var{fs})
947 @c ----------------------------------------------------------------------
949 @node Allocating Bitmaps, Free bitmaps, Reading and Writing Bitmaps, Bitmap Functions
950 @comment node-name, next, previous, up
951 @subsection Allocating Bitmaps
953 @deftypefun errcode_t ext2fs_allocate_generic_bitmap (__u32 @var{start}, __u32 @var{end}, _u32 @var{real_end}, const char *@var{descr}, ext2fs_generic_bitmap *@var{ret})
956 @deftypefun errcode_t ext2fs_allocate_block_bitmap (ext2_filsys @var{fs}, const char *@var{descr}, ext2fs_block_bitmap *@var{ret})
959 @deftypefun errcode_t ext2fs_allocate_inode_bitmap (ext2_filsys @var{fs}, const char *@var{descr}, ext2fs_inode_bitmap *@var{ret})
962 @c ----------------------------------------------------------------------
964 @node Free bitmaps, Bitmap Operations, Allocating Bitmaps, Bitmap Functions
965 @comment node-name, next, previous, up
966 @subsection Freeing bitmaps
969 @deftypefun void ext2fs_free_generic_bitmap (ext2fs_inode_bitmap @var{bitmap})
972 @deftypefun void ext2fs_free_block_bitmap (ext2fs_block_bitmap @var{bitmap})
975 @deftypefun void ext2fs_free_inode_bitmap (ext2fs_inode_bitmap @var{bitmap})
979 @c ----------------------------------------------------------------------
981 @node Bitmap Operations, Comparing bitmaps, Free bitmaps, Bitmap Functions
982 @comment node-name, next, previous, up
983 @subsection Bitmap Operations
985 @deftypefun void ext2fs_mark_block_bitmap (ext2fs_block_bitmap @var{bitmap}, blk_t @var{block})
987 @deftypefunx void ext2fs_unmark_block_bitmap (ext2fs_block_bitmap @var{bitmap}, blk_t @var{block})
989 @deftypefunx int ext2fs_test_block_bitmap (ext2fs_block_bitmap @var{bitmap}, blk_t @var{block})
991 These functions set, clear, and test bits in a block bitmap @var{bitmap}.
995 @deftypefun void ext2fs_mark_inode_bitmap (ext2fs_inode_bitmap @var{bitmap}, ext2_ino_t @var{inode})
997 @deftypefunx void ext2fs_unmark_inode_bitmap (ext2fs_inode_bitmap @var{bitmap}, ext2_ino_t @var{inode})
999 @deftypefunx int ext2fs_test_inode_bitmap (ext2fs_inode_bitmap @var{bitmap}, ext2_ino_t @var{inode})
1001 These functions set, clear, and test bits in an inode bitmap @var{bitmap}.
1004 @deftypefun void ext2fs_fast_mark_block_bitmap (ext2fs_block_bitmap @var{bitmap}, blk_t @var{block})
1006 @deftypefunx void ext2fs_fast_unmark_block_bitmap (ext2fs_block_bitmap @var{bitmap}, blk_t @var{block})
1008 @deftypefunx int ext2fs_fast_test_block_bitmap (ext2fs_block_bitmap @var{bitmap}, blk_t @var{block})
1010 @deftypefunx void ext2fs_fast_mark_inode_bitmap (ext2fs_inode_bitmap @var{bitmap}, ext2_ino_t @var{inode})
1012 @deftypefunx void ext2fs_fast_unmark_inode_bitmap (ext2fs_inode_bitmap @var{bitmap}, ext2_ino_t @var{inode})
1014 @deftypefunx int ext2fs_fast_test_inode_bitmap (ext2fs_inode_bitmap @var{bitmap}, ext2_ino_t @var{inode})
1016 These ``fast'' functions are like their normal counterparts; however,
1017 they are implemented as inline functions and do not perform bounds
1018 checks on the inode number or block number; they are assumed to be
1019 correct. They should only be used in speed-critical applications, where
1020 the inode or block number has already been validated by other means.
1023 @deftypefun blk_t ext2fs_get_block_bitmap_start (ext2fs_block_bitmap @var{bitmap})
1024 @deftypefunx ext2_ino_t ext2fs_get_inode_bitmap_start (ext2fs_inode_bitmap @var{bitmap})
1025 Return the first inode or block which is stored in the bitmap.
1028 @deftypefun blk_t ext2fs_get_block_bitmap_end (ext2fs_block_bitmap @var{bitmap})
1029 @deftypefunx ext2_ino_t ext2fs_get_inode_bitmap_end (ext2fs_inode_bitmap @var{bitmap})
1031 Return the last inode or block which is stored in the bitmap.
1035 @c ----------------------------------------------------------------------
1037 @node Comparing bitmaps, Modifying Bitmaps, Bitmap Operations, Bitmap Functions
1038 @comment node-name, next, previous, up
1039 @subsection Comparing bitmaps
1041 @deftypefun errcode_t ext2fs_compare_block_bitmap (ext2fs_block_bitmap @var{bm1}, ext2fs_block_bitmap @var{bm2})
1044 @deftypefun errcode_t ext2fs_compare_inode_bitmap (ext2fs_inode_bitmap @var{bm1}, ext2fs_inode_bitmap @var{bm2})
1048 @c ----------------------------------------------------------------------
1050 @node Modifying Bitmaps, Resizing Bitmaps, Comparing bitmaps, Bitmap Functions
1051 @comment node-name, next, previous, up
1052 @subsection Modifying Bitmaps
1054 @deftypefun errcode_t ext2fs_fudge_inode_bitmap_end (ext2fs_inode_bitmap @var{bitmap}, ext2_ino_t @var{end}, ext2_ino_t *@var{oend})
1057 @deftypefun errcode_t ext2fs_fudge_block_bitmap_end (ext2fs_block_bitmap @var{bitmap}, blk_t @var{end}, blk_t *@var{oend})
1060 @c ----------------------------------------------------------------------
1062 @node Resizing Bitmaps, Clearing Bitmaps, Modifying Bitmaps, Bitmap Functions
1063 @comment node-name, next, previous, up
1064 @subsection Resizing Bitmaps
1066 @deftypefun errcode_t ext2fs_resize_generic_bitmap (__u32 @var{new_end}, __u32 @var{new_real_end}, ext2fs_generic_bitmap @var{bmap})
1069 @deftypefun errcode_t ext2fs_resize_inode_bitmap (__u32 @var{new_end}, __u32 @var{new_real_end}, ext2fs_inode_bitmap @var{bmap})
1072 @deftypefun errcode_t ext2fs_resize_block_bitmap (__u32 @var{new_end}, __u32 @var{new_real_end}, ext2fs_block_bitmap @var{bmap})
1076 @c ----------------------------------------------------------------------
1078 @node Clearing Bitmaps, , Resizing Bitmaps, Bitmap Functions
1079 @comment node-name, next, previous, up
1080 @subsection Clearing Bitmaps
1082 @deftypefun void ext2fs_clear_inode_bitmap (ext2fs_inode_bitmap @var{bitmap})
1084 This function sets all of the bits in the inode bitmap @var{bitmap} to
1089 @deftypefun void ext2fs_clear_block_bitmap (ext2fs_block_bitmap @var{bitmap})
1091 This function sets all of the bits in the block bitmap @var{bitmap} to
1096 @c ----------------------------------------------------------------------
1098 @node EXT2 data abstractions, Byte-swapping functions, Bitmap Functions, EXT2FS Library Functions
1099 @comment node-name, next, previous, up
1100 @section EXT2 data abstractions
1102 The ext2 library has a number of abstractions which are useful for ext2
1106 * Badblocks list management::
1107 * Directory-block list management::
1108 * Inode count functions::
1111 @c ----------------------------------------------------------------------
1113 @node Badblocks list management, Directory-block list management, EXT2 data abstractions, EXT2 data abstractions
1114 @comment node-name, next, previous, up
1115 @subsection Badblocks list management
1118 @deftypefun errcode_t ext2fs_badblocks_list_create (ext2_badblocks_list *@var{ret}, int @var{size})
1121 @deftypefun void ext2fs_badblocks_list_free (ext2_badblocks_list @var{bb})
1124 @deftypefun errcode_t ext2fs_badblocks_list_add (ext2_badblocks_list @var{bb}, blk_t @var{blk})
1127 @deftypefun int ext2fs_badblocks_list_test (ext2_badblocks_list @var{bb}, blk_t @var{blk})
1130 @deftypefun errcode_t ext2fs_badblocks_list_iterate_begin (ext2_badblocks_list @var{bb}, ext2_badblocks_iterate *@var{ret})
1133 @deftypefun int ext2fs_badblocks_list_iterate (ext2_badblocks_iterate iter, blk_t *@var{blk})
1136 @deftypefun void ext2fs_badblocks_list_iterate_end (ext2_badblocks_iterate @var{iter})
1139 @deftypefun errcode_t ext2fs_update_bb_inode (ext2_filsys @var{fs}, ext2_badblocks_list @var{bb_list})
1142 @deftypefun errcode_t ext2fs_read_bb_inode (ext2_filsys @var{fs}, ext2_badblocks_list *@var{bb_list})
1145 @deftypefun errcode_t ext2fs_read_bb_FILE (ext2_filsys @var{fs}, FILE *f, ext2_badblocks_list *@var{bb_list}, void (*invalid)(ext2_filsys @var{fs}, blk_t @var{blk}))
1149 @c ----------------------------------------------------------------------
1151 @node Directory-block list management, Inode count functions, Badblocks list management, EXT2 data abstractions
1152 @comment node-name, next, previous, up
1153 @subsection Directory-block list management
1155 The dblist abstraction stores a list of blocks belonging to
1156 directories. This list can be useful when a program needs to interate
1157 over all directory entries in a filesystem; @code{e2fsck} does this in
1158 pass 2 of its operations, and @code{debugfs} needs to do this when it is
1159 trying to turn an inode number into a pathname.
1161 @deftypefun errcode_t ext2fs_init_dblist (ext2_filsys @var{fs}, ext2_dblist *@var{ret_dblist})
1163 Creates a dblist data structure and return it in @var{ret_dblist}.
1166 @deftypefun void ext2fs_free_dblist (ext2_dblist @var{dblist})
1168 Free a dblist data structure.
1171 @deftypefun errcode_t ext2fs_add_dir_block (ext2_dblist @var{dblist}, ext2_ino_t @var{ino}, blk_t @var{blk}, int @var{blockcnt})
1173 Add an entry to the dblist data structure. This call records the fact
1174 that block number @var{blockcnt} of directory inode @var{ino} is stored
1178 @deftypefun errcode_t ext2fs_set_dir_block (ext2_dblist @var{dblist}, ext2_ino_t @var{ino}, blk_t @var{blk}, int @var{blockcnt})
1180 Change an entry in the dblist data structure; this changes the location
1181 of block number @var{blockcnt} of directory indoe @var{ino} to be block
1185 @deftypefun errcode_t ext2fs_dblist_iterate (ext2_dblist @var{dblist}, int (*func)(ext2_filsys @var{fs}, struct ext2_db_entry *@var{db_info}, void *@var{private}), void *@var{private})
1187 This iterator calls @var{func} for every entry in the dblist data structure.
1190 @deftypefun errcode_t ext2fs_dblist_dir_iterate (ext2_dblist @var{dblist}, int flags, char *@var{block_buf}, int (*func)(ext2_ino_t @var{dir}, int @var{entry}, struct ext2_dir_entry *@var{dirent}, int @var{offset}, int @var{blocksize}, char *@var{buf}, void *@var{private}), void *@var{private})
1192 This iterator takes reads in the directory block indicated in each
1193 dblist entry, and calls @var{func} for each directory entry in each
1194 directory block. If @var{dblist} contains all the directory blocks in a
1195 filesystem, this function provides a convenient way to iterate over all
1196 directory entries for that filesystem.
1199 @c ----------------------------------------------------------------------
1201 @node Inode count functions, , Directory-block list management, EXT2 data abstractions
1202 @comment node-name, next, previous, up
1203 @subsection Inode count functions
1205 The icount abstraction is a specialized data type used by @code{e2fsck}
1206 to store how many times a particular inode is referenced by the
1207 filesystem. This is used twice; once to store the actual number of times
1208 that the inode is reference; and once to store the claimed number of times
1209 the inode is referenced according to the inode structure.
1211 This abstraction is designed to be extremely efficient for storing this
1212 sort of information, by taking advantage of the following properties of
1213 inode counts, namely (1) inode counts are very often zero (because
1214 the inode is currrently not in use), and (2) many files have a inode
1215 count of 1 (because they are a file which has no additional hard links).
1217 @deftypefun errcode_t ext2fs_create_icount2 (ext2_filsys @var{fs}, int @var{flags}, int @var{size}, ext2_icount_t @var{hint}, ext2_icount_t *@var{ret})
1219 Creates an icount stucture for a filesystem @var{fs}, with initial space
1220 for @var{size} inodes whose count is greater than 1. The @var{flags}
1221 parameter is either 0 or @code{EXT2_ICOUNT_OPT_INCREMENT}, which
1222 indicates that icount structure should be able to increment inode counts
1223 quickly. The icount structure is returned in @var{ret}. The returned
1224 icount structure initially has a count of zero for all inodes.
1226 The @var{hint} parameter allows the caller to optionally pass in another
1227 icount structure which is used to initialize the array of inodes whose
1228 count is greater than 1. It is used purely as a speed optimization so
1229 that the icount structure can determine in advance which inodes are
1230 likely to contain a count grater than 1.
1233 @deftypefun void ext2fs_free_icount (ext2_icount_t @var{icount})
1235 Frees an icount structure.
1238 @deftypefun errcode_t ext2fs_icount_fetch (ext2_icount_t @var{icount}, ext2_ino_t @var{ino}, __u16 *@var{ret})
1240 Returns in @var{ret} fetches the count for a particular inode @var{ino}.
1243 @deftypefun errcode_t ext2fs_icount_increment (ext2_icount_t @var{icount}, ext2_ino_t @var{ino}, __u16 *@var{ret})
1245 Increments the ref count for inode @var{ino}.
1248 @deftypefun errcode_t ext2fs_icount_decrement (ext2_icount_t @var{icount}, ext2_ino_t @var{ino}, __u16 *@var{ret})
1250 Decrements the ref count for inode @var{ino}.
1253 @deftypefun errcode_t ext2fs_icount_store (ext2_icount_t @var{icount}, ext2_ino_t @var{ino}, __u16 @var{count})
1255 Sets the reference count for inode @var{ino} to be @var{count}.
1258 @deftypefun ext2_ino_t ext2fs_get_icount_size (ext2_icount_t @var{icount})
1260 Returns the current number of inodes in @var{icount} which has a count
1264 @deftypefun errcode_t ext2fs_icount_validate (ext2_icount_t @var{icount}, FILE *@var{f})
1266 Validates the internal rep invariant of @var{icount}; if there are any
1267 problems, print out debugging information to @var{f}. This function is
1268 intended for debugging and testing use only.
1272 @c ----------------------------------------------------------------------
1274 @node Byte-swapping functions, Other functions, EXT2 data abstractions, EXT2FS Library Functions
1275 @comment node-name, next, previous, up
1276 @section Byte-swapping functions
1278 @deftypefun void ext2fs_swap_super (struct ext2_super_block * @var{super})
1281 @deftypefun void ext2fs_swap_group_desc (struct ext2_group_desc *@var{gdp})
1284 @deftypefun void ext2fs_swap_inode (ext2_filsys @var{fs}, struct ext2_inode *@var{to}, struct ext2_inode *@var{from}, int @var{hostorder})
1287 @deftypefun int ext2fs_native_flag (void)
1291 @c ----------------------------------------------------------------------
1293 @node Other functions, , Byte-swapping functions, EXT2FS Library Functions
1294 @comment node-name, next, previous, up
1295 @section Other functions
1298 @deftypefun errcode_t ext2fs_new_inode (ext2_filsys @var{fs}, ext2_ino_t @var{dir}, int @var{mode}, ext2fs_inode_bitmap @var{map}, ext2_ino_t *@var{ret})
1301 @deftypefun errcode_t ext2fs_new_block (ext2_filsys @var{fs}, blk_t @var{goal}, ext2fs_block_bitmap @var{map}, blk_t *@var{ret})
1304 @deftypefun errcode_t ext2fs_get_free_blocks (ext2_filsys @var{fs}, blk_t @var{start}, blk_t @var{finish}, int @var{num}, ext2fs_block_bitmap @var{map}, blk_t *@var{ret})
1308 @deftypefun errcode_t ext2fs_check_desc (ext2_filsys @var{fs})
1311 @deftypefun errcode_t ext2fs_get_num_dirs (ext2_filsys @var{fs}, ext2_ino_t *@var{ret_num_dirs})
1316 @deftypefun errcode_t ext2fs_get_device_size (const char *@var{file}, int @var{blocksize}, blk_t *@var{retblocks})
1321 @deftypefun errcode_t ext2fs_check_if_mounted (const char *@var{file}, int *@var{mount_flags})
1326 @deftypefun int ext2fs_get_library_version (const char **@var{ver_string}, const char **@var{date_string})
1328 This function returns the current version of the ext2 library. The
1329 return value contains an integer version code, which consists of the
1330 major version number of the library multiplied by 100, plus the minor
1331 version number of the library. Hence, if the library version is 1.08,
1332 the returned value will be 108.
1334 If @var{ver_string} and/or @var{date_string} are non-NULL, they will be
1335 set to point at a constant string containing the library version and/or
1336 release date, respectively.
1339 @deftypefun int ext2fs_parse_version_string (const char *@var{ver_string})
1341 This function takes a version string which may included in an
1342 application and returns a version code using the same algorithm used by
1343 @code{ext2fs_get_library_version}. It can be used by programs included
1344 in the @code{e2fsprogs} distribution to assure that they are using an
1345 up-to-date ext2 shared library.
1348 /* inline functions */
1349 @deftypefun int ext2fs_group_of_blk (ext2_filsys @var{fs}, blk_t @var{blk})
1351 This function returns the block group which contains the block @var{blk}.
1355 @deftypefun int ext2fs_group_of_ino (ext2_filsys @var{fs}, ext2_ino_t @var{ino})
1357 This function returns the block group which contains the inode @var{ino}.
1361 @c ----------------------------------------------------------------------
1363 @node Concept Index, Function Index, EXT2FS Library Functions, Top
1364 @comment node-name, next, previous, up
1365 @unnumbered Concept Index
1368 @c ----------------------------------------------------------------------
1370 @node Function Index, , Concept Index, Top
1371 @comment node-name, next, previous, up
1372 @unnumbered Function and Type Index