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diff --git a/doc/libext2fs.texinfo b/doc/libext2fs.texinfo new file mode 100644 index 0000000..5d4b053 --- /dev/null +++ b/doc/libext2fs.texinfo @@ -0,0 +1,1374 @@ +\input texinfo @c -*-texinfo-*- +@c %**start of header +@setfilename libext2fs.info +@settitle The EXT2FS Library (version 1.47.0) +@synindex tp fn +@comment %**end of header + +@ifinfo +@dircategory Development +@direntry +* libext2fs: (libext2fs). The EXT2FS library. +@end direntry +@end ifinfo + +@c smallbook + +@iftex +@finalout +@end iftex + +@c Note: the edition number is listed in *three* places; please update +@c all three. Also, update the month and year where appropriate. + +@c ==> Update edition number for settitle and subtitle, and in the +@c ==> following paragraph; update date, too. + + +@ifinfo +This file documents the ext2fs library, a library for manipulating the +ext2 filesystem. + +Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, +2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014 by Theodore Ts'o + +Permission is granted to make and distribute verbatim copies of +this manual provided the copyright notice and this permission notice +are preserved on all copies. + +@ignore +Permission is granted to process this file through TeX and print the +results, provided the printed document carries copying permission +notice identical to this one except for the removal of this paragraph +(this paragraph not being relevant to the printed manual). + +@end ignore +Permission is granted to copy and distribute modified versions of this +manual under the conditions for verbatim copying, provided that the entire +resulting derived work is distributed under the terms of a permission +notice identical to this one. + +Permission is granted to copy and distribute translations of this manual +into another language, under the above conditions for modified versions, +except that this permission notice may be stated in a translation approved +by the author. +@end ifinfo + +@setchapternewpage on +@titlepage +@c use the new format for titles + +@title The EXT2FS Library +@subtitle The EXT2FS Library +@subtitle Version 1.47.0 +@subtitle February 2023 + +@author by Theodore Ts'o + +@c Include the Distribution inside the titlepage so +@c that headings are turned off. + +@tex +\global\parindent=0pt +\global\parskip=8pt +\global\baselineskip=13pt +@end tex + +@page +@vskip 0pt plus 1filll +Copyright @copyright{} 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, +2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014 Theodore Ts'o + +@sp 2 + +Permission is granted to make and distribute verbatim copies of +this manual provided the copyright notice and this permission notice +are preserved on all copies. + +Permission is granted to copy and distribute modified versions of this +manual under the conditions for verbatim copying, provided that the entire +resulting derived work is distributed under the terms of a permission +notice identical to this one. + +Permission is granted to copy and distribute translations of this manual +into another language, under the above conditions for modified versions, +except that this permission notice may be stated in a translation approved +by the Foundation. +@end titlepage +@headings double + +@node Top, Introduction to the EXT2FS Library, (dir), (dir) + +@top The EXT2FS Library + +This manual documents the EXT2FS Library, version 1.47.0. + +@menu +* Introduction to the EXT2FS Library:: +* EXT2FS Library Functions:: +* Concept Index:: +* Function Index:: +@end menu + +@c ---------------------------------------------------------------------- + +@node Introduction to the EXT2FS Library, EXT2FS Library Functions, Top, Top +@comment node-name, next, previous, up +@chapter Introduction to the EXT2FS Library + +The EXT2FS library is designed to allow user-level programs to +manipulate an ext2 filesystem. + +@node EXT2FS Library Functions, Concept Index, Introduction to the EXT2FS Library, Top +@comment node-name, next, previous, up +@chapter EXT2FS Library Functions + +@menu +* Filesystem-level functions:: +* File I/O Functions:: +* Inode Functions:: +* Directory functions:: +* Bitmap Functions:: +* EXT2 data abstractions:: +* Byte-swapping functions:: +* Other functions:: +@end menu + +@c ---------------------------------------------------------------------- + +@node Filesystem-level functions, File I/O Functions, EXT2FS Library Functions, EXT2FS Library Functions +@comment node-name, next, previous, up +@section Filesystem-level functions + +The following functions operate on a filesystem handle. Most EXT2FS +Library functions require a filesystem handle as their first argument. +There are two functions which create a filesystem handle, +@code{ext2fs_open} and @code{ext2fs_initialize}. + +The filesystem can also be closed using @code{ext2fs_close}, and any +changes to the superblock and group descriptors can be written out to disk +using @code{ext2fs_flush}. + +@menu +* Opening an ext2 filesystem:: +* Closing and flushing out changes:: +* Initializing a filesystem:: +* Filesystem flag functions:: +@end menu + +@c ---------------------------------------------------------------------- + +@node Opening an ext2 filesystem, Closing and flushing out changes, Filesystem-level functions, Filesystem-level functions +@comment node-name, next, previous, up +@subsection Opening an ext2 filesystem + +Most libext2fs functions take a filesystem handle of type +@code{ext2_filsys}. A filesystem handle is created either by opening +an existing filesystem using @code{ext2fs_open}, or by initializing a new +filesystem using @code{ext2fs_initialize}. + +@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}) + +Opens a filesystem named @var{name}, using the the io_manager +@var{manager} to define the input/output routines needed to read and +write the filesystem. In the case of the @code{unix_io} io_manager, +@var{name} is interpreted as the Unix filename of the filesystem image. +This is often a device file, such as @file{/dev/hda1}. + +The @var{superblock} parameter specifies the block number of the +superblock which should be used when opening the filesystem. +If @var{superblock} is zero, @code{ext2fs_open} will use the primary +superblock located at offset 1024 bytes from the start of the filesystem +image. + +The @var{block_size} parameter specifies the block size used by the +filesystem. Normally this is determined automatically from the +filesystem superblock. If @var{block_size} is non-zero, it must match +the block size found in the superblock, or the error +@code{EXT2_ET_UNEXPECTED_BLOCK_SIZE} will be returned. The +@var{block_size} parameter is also used to help find the superblock when +@var{superblock} is non-zero. + +The @var{flags} argument contains a bitmask of flags which control how +the filesystem open should be handled. + +@table @code +@item EXT2_FLAG_RW +Open the filesystem for reading and writing. Without this flag, the +filesystem is opened for reading only. + +@item EXT2_FLAG_FORCE +Open the filesystem regardless of the feature sets listed in the +superblock. + +@end table +@end deftypefun + +@c ---------------------------------------------------------------------- + +@node Closing and flushing out changes, Initializing a filesystem, Opening an ext2 filesystem, Filesystem-level functions +@comment node-name, next, previous, up +@subsection Closing and flushing out changes + +@deftypefun errcode_t ext2fs_flush (ext2_filsys @var{fs}) + +Write any changes to the high-level filesystem data structures in the +@var{fs} filesystem. The following data structures will be written out: + +@itemize @bullet +@item The filesystem superblock +@item The filesystem group descriptors +@item The filesystem bitmaps, if read in via @code{ext2fs_read_bitmaps}. +@end itemize + +@end deftypefun + +@deftypefun void ext2fs_free (ext2_filsys @var{fs}) + +Close the io_manager abstraction for @var{fs} and release all memory +associated with the filesystem handle. +@end deftypefun + +@deftypefun errcode_t ext2fs_close (ext2_filsys @var{fs}) + +Flush out any changes to the high-level filesystem data structures using +@code{ext2fs_flush} if the filesystem is marked dirty; then close and +free the filesystem using @code{ext2fs_free}. + +@end deftypefun + +@c ---------------------------------------------------------------------- + +@node Initializing a filesystem, Filesystem flag functions, Closing and flushing out changes, Filesystem-level functions +@comment node-name, next, previous, up +@subsection Initializing a filesystem + +An ext2 filesystem is initializing by the @code{mke2fs} program. The +two functions described here, @code{ext2fs_initialize} and +@code{ext2fs_allocate_tables} do much of the initial work for setting up +a filesystem. However, they don't do the whole job. @code{mke2fs} +calls @code{ext2fs_initialize} to set up the filesystem superblock, and +calls @code{ext2fs_allocate_tables} to allocate space for the inode +table, and the inode and block bitmaps. In addition, @code{mke2fs} must +also initialize the inode tables by clearing them with zeros, create the +root and lost+found directories, and reserve the reserved inodes. + +@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}) + +This function is used by the @code{mke2fs} program to initialize a +filesystem. The @code{ext2fs_initialize} function creates a filesystem +handle which is returned in @var{ret_fs} that has been properly setup +for a filesystem to be located in @var{name}, using the io_manager +@var{manager}. The prototype superblock in @var{param} is used to +supply parameters such as the number of blocks in the filesystem, the +block size, etc. + +The @code{ext2fs_initialize} function does not actually do any I/O; that +will be done when the application program calls @code{ext2fs_close} or +@code{ext2fs_flush}. Also, this function only initializes the +superblock and group descriptor structures. It does not create the +inode table or the root directory. This must be done by the calling +application, such as @code{mke2fs}. + +The following values may be set in the @var{param} prototype superblock; +if a value of 0 is found in a field, @code{ext2fs_initialize} will use a +default value. The calling application should zero out the prototype +entire superblock, and then fill in any appropriate values. + +@table @code + +@item s_blocks_count +The number of blocks in the filesystem. This parameter is mandatory and +must be set by the calling application. + +@item s_inodes_count +The number of inodes in the filesystem. The +default value is determined by calculating the size of the filesystem, +and creating one inode for every 4096 bytes. + +@item s_r_blocks_count +The number of blocks which should be reserved for the superuser. The +default value is zero blocks. + +@item s_log_block_size +The blocksize of the filesystem. Valid values are 0 (1024 bytes), 1 +(2048 bytes), or 2 (4096 bytes). The default blocksize is 1024 bytes. + +@item s_log_frag_size +The size of fragments. The ext2 filesystem does not support fragments +(and may never support fragments). Currently this field must be the +same as @code{s_log_block_size}. + +@item s_first_data_block +The first data block for the filesystem. For filesystem with a +blocksize of 1024 bytes, this value must be at least 1, since the +superblock is located in block number 1. For filesystems with larger +blocksizes, the superblock is still located at an offset of 1024 bytes, +so the superblock is located in block number 0. By default, this value +is set to 1 for filesystems with a block size of 1024 bytes, or 0 for +filesystems with larger blocksizes. + +@item s_max_mnt_count +This field defines the number of times that the filesystem can be +mounted before it should be checked using @code{e2fsck}. When +@code{e2fsck} is run without the @samp{-f} option, @code{e2fsck} will +skip the filesystem check if the number of times that the filesystem has +been mounted is less than @code{s_max_mnt_count} and if the interval +between the last time a filesystem check was performed and the current +time is less than @code{s_checkinterval} (see below). The default value +of @code{s_max_mnt_count} is 20. + +@item s_checkinterval +This field defines the minimal interval between filesystem checks. See +the previous entry for a discussion of how this field is used by +@code{e2fsck}. The default value of this field is 180 days (six +months). + +@item s_errors +This field defines the behavior which should be used by the kernel of +errors are detected in the filesystem. Possible values include: + +@table @samp +@item EXT2_ERRORS_CONTINUE +Continue execution when errors are detected. + +@item EXT2_ERRORS_RO +Remount the filesystem read-only. + +@item EXT2_ERRORS_PANIC +Panic. + +@end table + +The default behavior is @samp{EXT2_ERRORS_CONTINUE}. + +@end table + +@end deftypefun + +@deftypefun errcode_t ext2fs_allocate_tables (ext2_filsys @var{fs}) +Allocate space for the inode table and the block and inode bitmaps. The +inode tables and block and inode bitmaps aren't actually initialized; +this function just allocates the space for them. +@end deftypefun + +@c ---------------------------------------------------------------------- + +@node Filesystem flag functions, , Initializing a filesystem, Filesystem-level functions +@comment node-name, next, previous, up +@subsection Filesystem flag functions + +The filesystem handle has a number of flags which can be manipulated +using the following function. Some of these flags affect how the +libext2fs filesystem behaves; others are provided solely for the +application's convenience. + +@deftypefun void ext2fs_mark_changed (ext2_filsys @var{fs}) +@deftypefunx int ext2fs_test_changed (ext2_filsys @var{fs}) +This flag indicates whether or not the filesystem has been changed. +It is not used by the ext2fs library. +@end deftypefun + +@deftypefun void ext2fs_mark_super_dirty (ext2_filsys @var{fs}) +Mark the filesystem @var{fs} as being dirty; this will cause +the superblock information to be flushed out when @code{ext2fs_close} is +called. @code{ext2fs_mark_super_dirty} will also set the filesystem +changed flag. The dirty flag is automatically cleared by +@code{ext2fs_flush} when the superblock is written to disk. +@end deftypefun + +@deftypefun void ext2fs_mark_valid (ext2_filsys @var{fs}) +@deftypefunx void ext2fs_unmark_valid (ext2_filsys @var{fs}) +@deftypefunx int ext2fs_test_valid (ext2_filsys @var{fs}) +This flag indicates whether or not the filesystem is free of errors. +It is not used by libext2fs, and is solely for the application's +convenience. +@end deftypefun + +@deftypefun void ext2fs_mark_ib_dirty (ext2_filsys @var{fs}) +@deftypefunx void ext2fs_mark_bb_dirty (ext2_filsys @var{fs}) +@deftypefunx int ext2fs_test_ib_dirty (ext2_filsys @var{fs}) +@deftypefunx int ext2fs_test_bb_dirty (ext2_filsys @var{fs}) +These flags indicate whether or not the inode or block bitmaps have been +modified. If the flag is set, it will cause the appropriate bitmap +to be written when the filesystem is closed or flushed. +@end deftypefun + +@c ---------------------------------------------------------------------- + +@node File I/O Functions, Inode Functions, Filesystem-level functions, EXT2FS Library Functions +@comment node-name, next, previous, up +@section File I/O Functions + +The following functions provide a convenient abstraction to read or +write a file in an filesystem. The interface is similar in spirit to +the Linux/POSIX file I/O system calls. + +@menu +* File handle manipulation:: +* Reading and writing data:: +* Changing the file offset :: +* Getting the file size:: +@end menu + +@c ---------------------------------------------------------------------- + +@node File handle manipulation, Reading and writing data, File I/O Functions, File I/O Functions +@comment node-name, next, previous, up +@subsection File handle manipulation + +The file handle functions much like a file descriptor in the Linux/POSIX +file I/O system calls. Unlike the Linux/POSIX system calls, files are +opened via inode numbers instead of via pathnames. To resolve a +pathname to an inode number, use the function @code{ext2fs_namei} or to +create a new file, use @code{ext2fs_new_inode} and @code{ext2fs_link}. + +@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}) +@deftypefunx errcode_t ext2fs_file_open (ext2_filsys @var{fs}, ext2_ino_t @var{ino}, int @var{flags}, ext2_file_t *@var{ret}) + +Opens a file identified by inode number @var{ino} in filesystem @var{fs} +and returns a file handle in @var{ret}. If an inode structure is +provided in @var{inode}, then it is used instead of reading the inode +from the filesystem. + +The @var{flags} argument contains a bitmask of flags which control how +the file should be opened. + +@table @code +@item EXT2_FILE_WRITE +Open the file for reading and writing. Without this flag, the file is +opened for writing only. + +@item EXT2_FILE_CREATE +Create the file if it is not already present. + +@end table +@end deftypefun + +@deftypefun ext2_filsys ext2fs_file_get_fs (ext2_file_t @var{file}) +Return the filesystem handle where the open file @var{file} was opened. +@end deftypefun + +@deftypefun errcode_t ext2fs_file_close (ext2_file_t @var{file}) +Close the file handle @var{file}. +@end deftypefun + +@deftypefun errcode_t ext2fs_file_flush (ext2_file_t @var{file}) +Force any data written via @code{ext2fs_file_write} to disk. +@end deftypefun + +@c ---------------------------------------------------------------------- + +@node Reading and writing data, Changing the file offset , File handle manipulation, File I/O Functions +@comment node-name, next, previous, up +@subsection Reading and writing data + +@deftypefun errcode_t ext2fs_file_read (ext2_file_t @var{file}, void *@var{buf}, unsigned int @var{wanted}, unsigned int *@var{got}) +Read @var{wanted} bytes of data from @var{file} store it in the buffer +@var{buf}. The number of bytes that was actually read is returned +via @var{got}. +@end deftypefun + +@deftypefun errcode_t ext2fs_file_write (ext2_file_t @var{file}, const void *@var{buf}, unsigned int @var{nbytes}, unsigned int *@var{written}) +Write @var{wanted} bytes of data from the buffer @var{buf} to the +current file position of @var{file}. The number of bytes that was +actually written is returned via @var{written}. +@end deftypefun + +@c ---------------------------------------------------------------------- + +@node Changing the file offset , Getting the file size, Reading and writing data, File I/O Functions +@comment node-name, next, previous, up +@subsection Changing the file offset + +@deftypefun errcode_t ext2fs_file_llseek (ext2_file_t @var{file}, __u64 @var{offset}, int @var{whence}, __u64 *@var{ret_pos}) +@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}) +Change the current file position of @var{file} according to the +directive @var{whence} as follows: + +@table @code +@item EXT2_SEEK_SET +The file position is set to @var{offset} bytes from the beginning of the +file. + +@item EXT2_SEEK_CUR +The file position set to its current location plus @var{offset} bytes. + +@item EXT2_SEEK_END +The file position is set to the size of the file plus @var{offset} +bytes. +@end table + +The current offset is returned via @var{ret_pos}. +@end deftypefun + +@c ---------------------------------------------------------------------- + +@node Getting the file size, , Changing the file offset , File I/O Functions +@comment node-name, next, previous, up +@subsection Getting the file size + +@deftypefun errcode_t ext2fs_file_get_lsize (ext2_file_t @var{file}, __u64 *@var{ret_size}) +Return the size of the file @var{file} in @var{ret_size}. +@end deftypefun + +@deftypefun ext2_off_t ext2fs_file_get_size (ext2_file_t @var{file}) +Return the size of the file @var{file}. +@end deftypefun + +@c ---------------------------------------------------------------------- + +@node Inode Functions, Directory functions, File I/O Functions, EXT2FS Library Functions +@comment node-name, next, previous, up +@section Inode Functions + +@menu +* Reading and writing inodes:: +* Iterating over inodes in a filesystem:: +* Iterating over blocks in an inode:: +* Inode Convenience Functions:: +@end menu + +@c ---------------------------------------------------------------------- + +@node Reading and writing inodes, Iterating over inodes in a filesystem, Inode Functions, Inode Functions +@comment node-name, next, previous, up +@subsection Reading and writing inodes + +@deftypefun errcode_t ext2fs_read_inode (ext2_filsys @var{fs}, ext2_ino_t @var{ino}, struct ext2_inode *@var{inode}) +Read the inode number @var{ino} into @var{inode}. +@end deftypefun + +@deftypefun errcode_t ext2fs_write_inode (ext2_filsys @var{fs}, ext2_ino_t @var{ino}, struct ext2_inode *@var{inode}) +Write @var{inode} to inode @var{ino}. +@end deftypefun + + +@c ---------------------------------------------------------------------- + +@node Iterating over inodes in a filesystem, Iterating over blocks in an inode, Reading and writing inodes, Inode Functions +@comment node-name, next, previous, up +@subsection Iterating over inodes in a filesystem + +The inode_scan abstraction is useful for iterating over all the inodes +in a filesystem. + +@deftypefun errcode_t ext2fs_open_inode_scan (ext2_filsys @var{fs}, int @var{buffer_blocks}, ext2_inode_scan *@var{scan}) +Initialize the iteration variable @var{scan}. This variable is used by +@code{ext2fs_get_next_inode}. The @var{buffer_blocks} parameter +controls how many blocks of the inode table are read in at a time. A +large number of blocks requires more memory, but reduces the overhead in +seeking and reading from the disk. If @var{buffer_blocks} is zero, a +suitable default value will be used. +@end deftypefun + +@deftypefun void ext2fs_close_inode_scan (ext2_inode_scan @var{scan}) +Release the memory associated with @var{scan} and invalidate it. +@end deftypefun + +@deftypefun errcode_t ext2fs_get_next_inode (ext2_inode_scan @var{scan}, ext2_ino_t *@var{ino}, struct ext2_inode *@var{inode}) + +This function returns the next inode from the filesystem; the inode +number of the inode is stored in @var{ino}, and the inode is stored in +@var{inode}. + +If the inode is located in a block that has been marked as bad, +@code{ext2fs_get_next_inode} will return the error +@code{EXT2_ET_BAD_BLOCK_IN_INODE_TABLE}. +@end deftypefun + +@deftypefun errcode_t ext2fs_inode_scan_goto_blockgroup (ext2_inode_scan @var{scan}, int @var{group}) +Start the inode scan at a particular ext2 blockgroup, @var{group}. +This function may be safely called at any time while @var{scan} is valid. +@end deftypefun + +@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}) +Register a callback function which will be called by +@code{ext2_get_next_inode} when all of the inodes in a block group have +been processed. +@end deftypefun + +@deftypefun int ext2fs_inode_scan_flags (ext2_inode_scan @var{scan}, int @var{set_flags}, int @var{clear_flags}) + +Set the scan_flags @var{set_flags} and clear the scan_flags @var{clear_flags}. +The following flags can be set using this interface: + +@table @samp + +@item EXT2_SF_SKIP_MISSING_ITABLE +When a block group is missing an inode table, skip it. If this flag is +not set @code{ext2fs_get_next_inode} will return the error +EXT2_ET_MISSING_INODE_TABLE. + +@end table + +@end deftypefun + +@c ---------------------------------------------------------------------- + +@node Iterating over blocks in an inode, Inode Convenience Functions, Iterating over inodes in a filesystem, Inode Functions +@comment node-name, next, previous, up +@subsection Iterating over blocks in an inode + +@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}) + +Iterate over all of the blocks in inode number @var{ino} in filesystem +@var{fs}, by calling the function @var{func} for each block in the +inode. The @var{block_buf} parameter should either be NULL, or if the +@code{ext2fs_block_iterate} function is called repeatedly, the overhead +of allocating and freeing scratch memory can be avoided by passing a +pointer to a scratch buffer which must be at least as big as three times the +filesystem's blocksize. + +The @var{flags} parameter controls how the iterator will function: + +@table @samp + +@item BLOCK_FLAG_HOLE +This flag indicates that the iterator function should be called on +blocks where the block number is zero (also known as ``holes''.) It is +also known as BLOCK_FLAG_APPEND, since it is also used by functions +such as ext2fs_expand_dir() to add a new block to an inode. + +@item BLOCK_FLAG_DEPTH_TRAVERSE +This flag indicates that the iterator function for the +indirect, doubly indirect, etc. blocks should be called after all +of the blocks contained in the indirect blocks are processed. +This is useful if you are going to be deallocating blocks from an +inode. + +@item BLOCK_FLAG_DATA_ONLY +This flag indicates that the iterator function should be +called for data blocks only. + +@end table + +The callback function @var{func} is called with a number of parameters; +the @var{fs} and @var{private} parameters are self-explanatory, and +their values are taken from the parameters to +@code{ext2fs_block_iterate}. (The @var{private} data structure is +generally used by callers to @code{ext2fs_block_iterate} so that some +private data structure can be passed to the callback function. The +@var{blockcnt} parameter, if non-negative, indicates the logical block +number of a data block in the inode. If @var{blockcnt} is less than +zero, then @var{func} was called on a metadata block, and @var{blockcnt} +will be one of the following values: BLOCK_COUNT_IND, BLOCK_COUNT_DIND, +BLOCK_COUNT_TIND, or BLOCK_COUNT_TRANSLATOR. The @var{blocknr} is a +pointer to the inode or indirect block entry listing physical block +number. The callback function may modify the physical block number, if +it returns the @var{BLOCK_CHANGED} flag. + + +The callback function @var{func} returns a result code which is composed of +the logical OR of the following flags: + +@table @samp + +@item BLOCK_CHANGED + +This flag indicates that callback function has modified the physical +block number pointed to by @var{blocknr}. + +@item BLOCK_ABORT + +This flag requests that @code{ext2fs_block_iterate} to stop immediately +and return to the caller. + +@end table + +@end deftypefun + +@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}) + +This function is much like @code{ext2fs_block_iterate}, except that the +@var{blockcnt} type is a 64-bit signed quantity, to support larger +files, and the addition of the @var{ref_blk} and @var{ref_offset} +arguments passed to the callback function, which identify the location +of the physical block pointed to by pointer @var{blocknr}. If +@var{ref_blk} is zero, then @var{ref_offset} contains the offset into +the @code{i_blocks} array. If @var{ref_blk} is non-zero, then the physical +block location is contained inside an indirect block group, and +@var{ref_offset} contains the offset into the indirect block. + +@end deftypefun + +@c ---------------------------------------------------------------------- + +@node Inode Convenience Functions, , Iterating over blocks in an inode, Inode Functions +@comment node-name, next, previous, up +@subsection Convenience functions for Inodes + +@deftypefun errcode_t ext2fs_get_blocks (ext2_filsys @var{fs}, ext2_ino_t @var{ino}, blk_t *@var{blocks}) + +Returns an array of blocks corresponding to the direct, +indirect, doubly indirect, and triply indirect blocks as stored in the +inode structure. +@end deftypefun + +@deftypefun errcode_t ext2fs_check_directory (ext2_filsys @var{fs}, ext2_ino_t @var{ino}) +Returns 0 if @var{ino} is a directory, and @code{ENOTDIR} if it is not. +@end deftypefun + +@deftypefun int ext2fs_inode_has_valid_blocks (struct ext2_inode *@var{inode}) + +Returns 1 if the inode's block entries actually valid block entries, and +0 if not. Inodes which represent devices and fast symbolic links do not +contain valid block entries. +@end deftypefun + +@c ---------------------------------------------------------------------- + +@node Directory functions, Bitmap Functions, Inode Functions, EXT2FS Library Functions +@comment node-name, next, previous, up +@section Directory functions + +@menu +* Directory block functions:: +* Iterating over a directory:: +* Creating and expanding directories:: +* Creating and removing directory entries:: +* Looking up filenames:: +* Translating inode numbers to filenames:: +@end menu + +@c ---------------------------------------------------------------------- + +@node Directory block functions, Iterating over a directory, Directory functions, Directory functions +@comment node-name, next, previous, up +@subsection Directory block functions + +@deftypefun errcode_t ext2fs_read_dir_block (ext2_filsys @var{fs}, blk_t @var{block}, void *@var{buf}) + +This function reads a directory block, performing +byte swapping if necessary. +@end deftypefun + +@deftypefun errcode_t ext2fs_write_dir_block (ext2_filsys @var{fs}, blk_t @var{block}, void *@var{buf}) + +This function writes a directory block, performing +byte swapping if necessary. +@end deftypefun + +@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}) + +This function creates a new directory block in @var{block}. If +@var{dir_ino} is non-zero, then @var{dir_ino} and @var{parent_ino} are used +to initialize directory entries for @file{.} and @file{..}, respectively. +@end deftypefun + +@c ---------------------------------------------------------------------- + +@node Iterating over a directory, Creating and expanding directories, Directory block functions, Directory functions +@comment node-name, next, previous, up +@subsection Iterating over a directory + +@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}) + +This function iterates over all of the directory entries in the +directory @var{dir}, calling the callback function @var{func} for each +directory entry in the directory. The @var{block_buf} parameter should +either be NULL, or if the @code{ext2fs_dir_iterate} function is +called repeatedly, the overhead of allocating and freeing +scratch memory can be avoided by passing a pointer to a scratch buffer +which must be at least as big as the filesystem's blocksize. + +The @var{flags} parameter controls how the iterator will function: + +@table @samp + +@item DIRENT_FLAG_INCLUDE_EMPTY + +This flag indicates that the callback function should be called even +for deleted or empty directory entries. + +@end table + +@end deftypefun + +@c ---------------------------------------------------------------------- + +@node Creating and expanding directories, Creating and removing directory entries, Iterating over a directory, Directory functions +@comment node-name, next, previous, up +@subsection Creating and expanding directories + +@deftypefun errcode_t ext2fs_mkdir (ext2_filsys @var{fs}, ext2_ino_t @var{parent}, ext2_ino_t @var{inum}, const char *@var{name}) + +This function creates a new directory. If @var{inum} is zero, then a +new inode will be allocated; otherwise, the directory will be created in +the inode specified by @var{inum}. If @var{name} specifies the name of +the new directory; if it is non-NULL, then the new directory will be +linked into the parent directory @var{parent}. +@end deftypefun + +@deftypefun errcode_t ext2fs_expand_dir (ext2_filsys @var{fs}, ext2_ino_t @var{dir}) + +This function adds a new empty directory block and appends it to +the directory @var{dir}. This allows functions such as +@code{ext2fs_link} to add new directory entries to a directory which is full. + +@end deftypefun + +@c ---------------------------------------------------------------------- + +@node Creating and removing directory entries, Looking up filenames, Creating and expanding directories, Directory functions +@comment node-name, next, previous, up +@subsection Creating and removing directory entries + +@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) + +This function adds a new directory entry to the directory @var{dir}, +with @var{name} and @var{ino} specifying the name and inode number in +the directory entry, respectively. + +The low 3 bits of the flags field is used to specify the file type of +inode: (No other flags are currently defined.) + +@table @samp + +@item EXT2_FT_UNKNOWN + +The file type is unknown. + +@item EXT2_FT_REG_FILE + +The file type is a normal file. + +@item EXT2_FT_DIR + +The file type is a directory. + +@item EXT2_FT_CHRDEV + +The file type is a character device. + +@item EXT2_FT_BLKDEV + +The file type is a block device. + +@item EXT2_FT_FIFO + +The file type is a named pipe. + +@item EXT2_FT_SOCK + +The file type is a unix domain socket. + +@item EXT2_FT_SYMLINK + +The file type is a symbolic link. +@end table + +@end deftypefun + +@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}) + +This function removes a directory entry from @var{dir}. +The directory entry to be removed is the first one which is +matched by @var{name} and @var{ino}. If @var{name} is non-NULL, +the directory entry's name must match @var{name}. If @var{ino} is +non-zero, the directory entry's inode number must match @var{ino}. +No flags are currently defined for @code{ext2fs_unlink}; callers should +pass in zero to this parameter. + +@end deftypefun + +@c ---------------------------------------------------------------------- + +@node Looking up filenames, Translating inode numbers to filenames, Creating and removing directory entries, Directory functions +@comment node-name, next, previous, up +@subsection Looking up filenames + +@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}) +@end deftypefun + +@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}) +@end deftypefun + +@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}) +@end deftypefun + +@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) +@end deftypefun + +@c ---------------------------------------------------------------------- + +@node Translating inode numbers to filenames, , Looking up filenames, Directory functions +@comment node-name, next, previous, up +@subsection Translating inode numbers to filenames + +@deftypefun errcode_t ext2fs_get_pathname (ext2_filsys @var{fs}, ext2_ino_t @var{dir}, ext2_ino_t @var{ino}, char **@var{name}) +@end deftypefun + + +@c ---------------------------------------------------------------------- + +@node Bitmap Functions, EXT2 data abstractions, Directory functions, EXT2FS Library Functions +@comment node-name, next, previous, up +@section Bitmap Functions + +@menu +* Reading and Writing Bitmaps:: +* Allocating Bitmaps:: +* Free bitmaps:: +* Bitmap Operations:: +* Comparing bitmaps:: +* Modifying Bitmaps:: +* Resizing Bitmaps:: +* Clearing Bitmaps:: +@end menu + +@c ---------------------------------------------------------------------- + +@node Reading and Writing Bitmaps, Allocating Bitmaps, Bitmap Functions, Bitmap Functions +@comment node-name, next, previous, up +@subsection Reading and Writing Bitmaps + +@deftypefun errcode_t ext2fs_write_inode_bitmap (ext2_filsys @var{fs}) +@end deftypefun + +@deftypefun errcode_t ext2fs_write_block_bitmap (ext2_filsys @var{fs}) +@end deftypefun + +@deftypefun errcode_t ext2fs_read_inode_bitmap (ext2_filsys @var{fs}) +@end deftypefun + +@deftypefun errcode_t ext2fs_read_block_bitmap (ext2_filsys @var{fs}) +@end deftypefun + +@deftypefun errcode_t ext2fs_read_bitmaps (ext2_filsys @var{fs}) +@end deftypefun + +@deftypefun errcode_t ext2fs_write_bitmaps (ext2_filsys @var{fs}) +@end deftypefun + +@c ---------------------------------------------------------------------- + +@node Allocating Bitmaps, Free bitmaps, Reading and Writing Bitmaps, Bitmap Functions +@comment node-name, next, previous, up +@subsection Allocating Bitmaps + +@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}) +@end deftypefun + +@deftypefun errcode_t ext2fs_allocate_block_bitmap (ext2_filsys @var{fs}, const char *@var{descr}, ext2fs_block_bitmap *@var{ret}) +@end deftypefun + +@deftypefun errcode_t ext2fs_allocate_inode_bitmap (ext2_filsys @var{fs}, const char *@var{descr}, ext2fs_inode_bitmap *@var{ret}) +@end deftypefun + +@c ---------------------------------------------------------------------- + +@node Free bitmaps, Bitmap Operations, Allocating Bitmaps, Bitmap Functions +@comment node-name, next, previous, up +@subsection Freeing bitmaps + + +@deftypefun void ext2fs_free_generic_bitmap (ext2fs_inode_bitmap @var{bitmap}) +@end deftypefun + +@deftypefun void ext2fs_free_block_bitmap (ext2fs_block_bitmap @var{bitmap}) +@end deftypefun + +@deftypefun void ext2fs_free_inode_bitmap (ext2fs_inode_bitmap @var{bitmap}) +@end deftypefun + + +@c ---------------------------------------------------------------------- + +@node Bitmap Operations, Comparing bitmaps, Free bitmaps, Bitmap Functions +@comment node-name, next, previous, up +@subsection Bitmap Operations + +@deftypefun void ext2fs_mark_block_bitmap (ext2fs_block_bitmap @var{bitmap}, blk_t @var{block}) + +@deftypefunx void ext2fs_unmark_block_bitmap (ext2fs_block_bitmap @var{bitmap}, blk_t @var{block}) + +@deftypefunx int ext2fs_test_block_bitmap (ext2fs_block_bitmap @var{bitmap}, blk_t @var{block}) + +These functions set, clear, and test bits in a block bitmap @var{bitmap}. +@end deftypefun + + +@deftypefun void ext2fs_mark_inode_bitmap (ext2fs_inode_bitmap @var{bitmap}, ext2_ino_t @var{inode}) + +@deftypefunx void ext2fs_unmark_inode_bitmap (ext2fs_inode_bitmap @var{bitmap}, ext2_ino_t @var{inode}) + +@deftypefunx int ext2fs_test_inode_bitmap (ext2fs_inode_bitmap @var{bitmap}, ext2_ino_t @var{inode}) + +These functions set, clear, and test bits in an inode bitmap @var{bitmap}. +@end deftypefun + +@deftypefun void ext2fs_fast_mark_block_bitmap (ext2fs_block_bitmap @var{bitmap}, blk_t @var{block}) + +@deftypefunx void ext2fs_fast_unmark_block_bitmap (ext2fs_block_bitmap @var{bitmap}, blk_t @var{block}) + +@deftypefunx int ext2fs_fast_test_block_bitmap (ext2fs_block_bitmap @var{bitmap}, blk_t @var{block}) + +@deftypefunx void ext2fs_fast_mark_inode_bitmap (ext2fs_inode_bitmap @var{bitmap}, ext2_ino_t @var{inode}) + +@deftypefunx void ext2fs_fast_unmark_inode_bitmap (ext2fs_inode_bitmap @var{bitmap}, ext2_ino_t @var{inode}) + +@deftypefunx int ext2fs_fast_test_inode_bitmap (ext2fs_inode_bitmap @var{bitmap}, ext2_ino_t @var{inode}) + +These ``fast'' functions are like their normal counterparts; however, +they are implemented as inline functions and do not perform bounds +checks on the inode number or block number; they are assumed to be +correct. They should only be used in speed-critical applications, where +the inode or block number has already been validated by other means. +@end deftypefun + +@deftypefun blk_t ext2fs_get_block_bitmap_start (ext2fs_block_bitmap @var{bitmap}) +@deftypefunx ext2_ino_t ext2fs_get_inode_bitmap_start (ext2fs_inode_bitmap @var{bitmap}) +Return the first inode or block which is stored in the bitmap. +@end deftypefun + +@deftypefun blk_t ext2fs_get_block_bitmap_end (ext2fs_block_bitmap @var{bitmap}) +@deftypefunx ext2_ino_t ext2fs_get_inode_bitmap_end (ext2fs_inode_bitmap @var{bitmap}) + +Return the last inode or block which is stored in the bitmap. +@end deftypefun + + +@c ---------------------------------------------------------------------- + +@node Comparing bitmaps, Modifying Bitmaps, Bitmap Operations, Bitmap Functions +@comment node-name, next, previous, up +@subsection Comparing bitmaps + +@deftypefun errcode_t ext2fs_compare_block_bitmap (ext2fs_block_bitmap @var{bm1}, ext2fs_block_bitmap @var{bm2}) +@end deftypefun + +@deftypefun errcode_t ext2fs_compare_inode_bitmap (ext2fs_inode_bitmap @var{bm1}, ext2fs_inode_bitmap @var{bm2}) +@end deftypefun + + +@c ---------------------------------------------------------------------- + +@node Modifying Bitmaps, Resizing Bitmaps, Comparing bitmaps, Bitmap Functions +@comment node-name, next, previous, up +@subsection Modifying Bitmaps + +@deftypefun errcode_t ext2fs_fudge_inode_bitmap_end (ext2fs_inode_bitmap @var{bitmap}, ext2_ino_t @var{end}, ext2_ino_t *@var{oend}) +@end deftypefun + +@deftypefun errcode_t ext2fs_fudge_block_bitmap_end (ext2fs_block_bitmap @var{bitmap}, blk_t @var{end}, blk_t *@var{oend}) +@end deftypefun + +@c ---------------------------------------------------------------------- + +@node Resizing Bitmaps, Clearing Bitmaps, Modifying Bitmaps, Bitmap Functions +@comment node-name, next, previous, up +@subsection Resizing Bitmaps + +@deftypefun errcode_t ext2fs_resize_generic_bitmap (__u32 @var{new_end}, __u32 @var{new_real_end}, ext2fs_generic_bitmap @var{bmap}) +@end deftypefun + +@deftypefun errcode_t ext2fs_resize_inode_bitmap (__u32 @var{new_end}, __u32 @var{new_real_end}, ext2fs_inode_bitmap @var{bmap}) +@end deftypefun + +@deftypefun errcode_t ext2fs_resize_block_bitmap (__u32 @var{new_end}, __u32 @var{new_real_end}, ext2fs_block_bitmap @var{bmap}) +@end deftypefun + + +@c ---------------------------------------------------------------------- + +@node Clearing Bitmaps, , Resizing Bitmaps, Bitmap Functions +@comment node-name, next, previous, up +@subsection Clearing Bitmaps + +@deftypefun void ext2fs_clear_inode_bitmap (ext2fs_inode_bitmap @var{bitmap}) + +This function sets all of the bits in the inode bitmap @var{bitmap} to +be zero. + +@end deftypefun + +@deftypefun void ext2fs_clear_block_bitmap (ext2fs_block_bitmap @var{bitmap}) + +This function sets all of the bits in the block bitmap @var{bitmap} to +be zero. +@end deftypefun + + +@c ---------------------------------------------------------------------- + +@node EXT2 data abstractions, Byte-swapping functions, Bitmap Functions, EXT2FS Library Functions +@comment node-name, next, previous, up +@section EXT2 data abstractions + +The ext2 library has a number of abstractions which are useful for ext2 +utility programs. + +@menu +* Badblocks list management:: +* Directory-block list management:: +* Inode count functions:: +@end menu + +@c ---------------------------------------------------------------------- + +@node Badblocks list management, Directory-block list management, EXT2 data abstractions, EXT2 data abstractions +@comment node-name, next, previous, up +@subsection Badblocks list management + + +@deftypefun errcode_t ext2fs_badblocks_list_create (ext2_badblocks_list *@var{ret}, int @var{size}) +@end deftypefun + +@deftypefun void ext2fs_badblocks_list_free (ext2_badblocks_list @var{bb}) +@end deftypefun + +@deftypefun errcode_t ext2fs_badblocks_list_add (ext2_badblocks_list @var{bb}, blk_t @var{blk}) +@end deftypefun + +@deftypefun int ext2fs_badblocks_list_test (ext2_badblocks_list @var{bb}, blk_t @var{blk}) +@end deftypefun + +@deftypefun errcode_t ext2fs_badblocks_list_iterate_begin (ext2_badblocks_list @var{bb}, ext2_badblocks_iterate *@var{ret}) +@end deftypefun + +@deftypefun int ext2fs_badblocks_list_iterate (ext2_badblocks_iterate iter, blk_t *@var{blk}) +@end deftypefun + +@deftypefun void ext2fs_badblocks_list_iterate_end (ext2_badblocks_iterate @var{iter}) +@end deftypefun + +@deftypefun errcode_t ext2fs_update_bb_inode (ext2_filsys @var{fs}, ext2_badblocks_list @var{bb_list}) +@end deftypefun + +@deftypefun errcode_t ext2fs_read_bb_inode (ext2_filsys @var{fs}, ext2_badblocks_list *@var{bb_list}) +@end deftypefun + +@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})) +@end deftypefun + + +@c ---------------------------------------------------------------------- + +@node Directory-block list management, Inode count functions, Badblocks list management, EXT2 data abstractions +@comment node-name, next, previous, up +@subsection Directory-block list management + +The dblist abstraction stores a list of blocks belonging to +directories. This list can be useful when a program needs to iterate +over all directory entries in a filesystem; @code{e2fsck} does this in +pass 2 of its operations, and @code{debugfs} needs to do this when it is +trying to turn an inode number into a pathname. + +@deftypefun errcode_t ext2fs_init_dblist (ext2_filsys @var{fs}, ext2_dblist *@var{ret_dblist}) + +Creates a dblist data structure and returns it in @var{ret_dblist}. +@end deftypefun + +@deftypefun void ext2fs_free_dblist (ext2_dblist @var{dblist}) + +Free a dblist data structure. +@end deftypefun + +@deftypefun errcode_t ext2fs_add_dir_block (ext2_dblist @var{dblist}, ext2_ino_t @var{ino}, blk_t @var{blk}, int @var{blockcnt}) + +Add an entry to the dblist data structure. This call records the fact +that block number @var{blockcnt} of directory inode @var{ino} is stored +in block @var{blk}. +@end deftypefun + +@deftypefun errcode_t ext2fs_set_dir_block (ext2_dblist @var{dblist}, ext2_ino_t @var{ino}, blk_t @var{blk}, int @var{blockcnt}) + +Change an entry in the dblist data structure; this changes the location +of block number @var{blockcnt} of directory inode @var{ino} to be block +@var{blk}. +@end deftypefun + +@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}) + +This iterator calls @var{func} for every entry in the dblist data structure. +@end deftypefun + +@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}) + +This iterator takes reads in the directory block indicated in each +dblist entry, and calls @var{func} for each directory entry in each +directory block. If @var{dblist} contains all the directory blocks in a +filesystem, this function provides a convenient way to iterate over all +directory entries for that filesystem. +@end deftypefun + +@c ---------------------------------------------------------------------- + +@node Inode count functions, , Directory-block list management, EXT2 data abstractions +@comment node-name, next, previous, up +@subsection Inode count functions + +The icount abstraction is a specialized data type used by @code{e2fsck} +to store how many times a particular inode is referenced by the +filesystem. This is used twice; once to store the actual number of times +that the inode is reference; and once to store the claimed number of times +the inode is referenced according to the inode structure. + +This abstraction is designed to be extremely efficient for storing this +sort of information, by taking advantage of the following properties of +inode counts, namely (1) inode counts are very often zero (because +the inode is currently not in use), and (2) many files have a inode +count of 1 (because they are a file which has no additional hard links). + +@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}) + +Creates an icount structure for a filesystem @var{fs}, with initial space +for @var{size} inodes whose count is greater than 1. The @var{flags} +parameter is either 0 or @code{EXT2_ICOUNT_OPT_INCREMENT}, which +indicates that icount structure should be able to increment inode counts +quickly. The icount structure is returned in @var{ret}. The returned +icount structure initially has a count of zero for all inodes. + +The @var{hint} parameter allows the caller to optionally pass in another +icount structure which is used to initialize the array of inodes whose +count is greater than 1. It is used purely as a speed optimization so +that the icount structure can determine in advance which inodes are +likely to contain a count grater than 1. +@end deftypefun + +@deftypefun void ext2fs_free_icount (ext2_icount_t @var{icount}) + +Frees an icount structure. +@end deftypefun + +@deftypefun errcode_t ext2fs_icount_fetch (ext2_icount_t @var{icount}, ext2_ino_t @var{ino}, __u16 *@var{ret}) + +Returns in @var{ret} the count for a particular inode @var{ino}. +@end deftypefun + +@deftypefun errcode_t ext2fs_icount_increment (ext2_icount_t @var{icount}, ext2_ino_t @var{ino}, __u16 *@var{ret}) + +Increments the ref count for inode @var{ino}. +@end deftypefun + +@deftypefun errcode_t ext2fs_icount_decrement (ext2_icount_t @var{icount}, ext2_ino_t @var{ino}, __u16 *@var{ret}) + +Decrements the ref count for inode @var{ino}. +@end deftypefun + +@deftypefun errcode_t ext2fs_icount_store (ext2_icount_t @var{icount}, ext2_ino_t @var{ino}, __u16 @var{count}) + +Sets the reference count for inode @var{ino} to be @var{count}. +@end deftypefun + +@deftypefun ext2_ino_t ext2fs_get_icount_size (ext2_icount_t @var{icount}) + +Returns the current number of inodes in @var{icount} which has a count +greater than 1. +@end deftypefun + +@deftypefun errcode_t ext2fs_icount_validate (ext2_icount_t @var{icount}, FILE *@var{f}) + +Validates the internal rep invariant of @var{icount}; if there are any +problems, print out debugging information to @var{f}. This function is +intended for debugging and testing use only. +@end deftypefun + + +@c ---------------------------------------------------------------------- + +@node Byte-swapping functions, Other functions, EXT2 data abstractions, EXT2FS Library Functions +@comment node-name, next, previous, up +@section Byte-swapping functions + +@deftypefun void ext2fs_swap_super (struct ext2_super_block * @var{super}) +@end deftypefun + +@deftypefun void ext2fs_swap_group_desc (struct ext2_group_desc *@var{gdp}) +@end deftypefun + +@deftypefun void ext2fs_swap_inode (ext2_filsys @var{fs}, struct ext2_inode *@var{to}, struct ext2_inode *@var{from}, int @var{hostorder}) +@end deftypefun + +@deftypefun int ext2fs_native_flag (void) +@end deftypefun + + +@c ---------------------------------------------------------------------- + +@node Other functions, , Byte-swapping functions, EXT2FS Library Functions +@comment node-name, next, previous, up +@section Other functions + +/* alloc.c */ +@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}) +@end deftypefun + +@deftypefun errcode_t ext2fs_new_block (ext2_filsys @var{fs}, blk_t @var{goal}, ext2fs_block_bitmap @var{map}, blk_t *@var{ret}) +@end deftypefun + +@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}) +@end deftypefun + +/* check_desc.c */ +@deftypefun errcode_t ext2fs_check_desc (ext2_filsys @var{fs}) +@end deftypefun + +@deftypefun errcode_t ext2fs_get_num_dirs (ext2_filsys @var{fs}, ext2_ino_t *@var{ret_num_dirs}) +@end deftypefun + + +/* getsize.c */ +@deftypefun errcode_t ext2fs_get_device_size (const char *@var{file}, int @var{blocksize}, blk_t *@var{retblocks}) +@end deftypefun + + +/* ismounted.c */ +@deftypefun errcode_t ext2fs_check_if_mounted (const char *@var{file}, int *@var{mount_flags}) +@end deftypefun + +/* version.c */ + +@deftypefun int ext2fs_get_library_version (const char **@var{ver_string}, const char **@var{date_string}) + +This function returns the current version of the ext2 library. The +return value contains an integer version code, which consists of the +major version number of the library multiplied by 100, plus the minor +version number of the library. Hence, if the library version is 1.08, +the returned value will be 108. + +If @var{ver_string} and/or @var{date_string} are non-NULL, they will be +set to point at a constant string containing the library version and/or +release date, respectively. +@end deftypefun + +@deftypefun int ext2fs_parse_version_string (const char *@var{ver_string}) + +This function takes a version string which may included in an +application and returns a version code using the same algorithm used by +@code{ext2fs_get_library_version}. It can be used by programs included +in the @code{e2fsprogs} distribution to assure that they are using an +up-to-date ext2 shared library. +@end deftypefun + +/* inline functions */ +@deftypefun int ext2fs_group_of_blk (ext2_filsys @var{fs}, blk_t @var{blk}) + +This function returns the block group which contains the block @var{blk}. + +@end deftypefun + +@deftypefun int ext2fs_group_of_ino (ext2_filsys @var{fs}, ext2_ino_t @var{ino}) + +This function returns the block group which contains the inode @var{ino}. +@end deftypefun + + +@c ---------------------------------------------------------------------- + +@node Concept Index, Function Index, EXT2FS Library Functions, Top +@comment node-name, next, previous, up +@unnumbered Concept Index +@printindex cp + +@c ---------------------------------------------------------------------- + +@node Function Index, , Concept Index, Top +@comment node-name, next, previous, up +@unnumbered Function and Type Index +@printindex fn + + +@contents +@bye |