From: Theodore Ts'o Date: Tue, 11 Dec 2001 15:15:31 +0000 (-0500) Subject: * Add new descriptions for the following functions: X-Git-Tag: E2FSPROGS-1_26-WIP-1224~19 X-Git-Url: https://git.whamcloud.com/?a=commitdiff_plain;h=5d57ad14f31f93384baa92c95d77008fc2ac803f;p=tools%2Fe2fsprogs.git * Add new descriptions for the following functions: ext2fs_block_iterate, ext2fs_block_iterate2, ext2fs_read_dir_block, ext2fs_write_dir_block, ext2fs_new_dir_block, ext2fs_dir_iterate, ext2fs_mkdir, ext2fs_expand_dir, ext2fs_link, ext2fs_unlink, ext2fs_clear_block_bitmap, ext2fs_set_block_bitmap, ext2fs_group_of_blk, ext2fs_group_of_ino. --- diff --git a/doc/ChangeLog b/doc/ChangeLog index 899f22f..e43c9c9 100644 --- a/doc/ChangeLog +++ b/doc/ChangeLog @@ -1,3 +1,13 @@ +2001-12-11 Theodore Tso + + * Add new descriptions for the following functions: + ext2fs_block_iterate, ext2fs_block_iterate2, + ext2fs_read_dir_block, ext2fs_write_dir_block, + ext2fs_new_dir_block, ext2fs_dir_iterate, ext2fs_mkdir, + ext2fs_expand_dir, ext2fs_link, ext2fs_unlink, + ext2fs_clear_block_bitmap, ext2fs_set_block_bitmap, + ext2fs_group_of_blk, ext2fs_group_of_ino. + 2001-09-20 Theodore Tso * Release of E2fsprogs 1.25 diff --git a/doc/libext2fs.texinfo b/doc/libext2fs.texinfo index 223274a..2b9f168 100644 --- a/doc/libext2fs.texinfo +++ b/doc/libext2fs.texinfo @@ -492,10 +492,89 @@ EXT2_ET_MISSING_INODE_TABLE. @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}) +@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 indiciates that the interator 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_TRAVERSE +This flag indicates that the iterator function for the +indirect, doubly indirect, etc. blocks should be called after all +of the blocks containined 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_iterate2}, 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 ---------------------------------------------------------------------- @@ -544,12 +623,24 @@ contain valid block entries. @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 any necessary +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 any necessary +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}) +@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_info} and @var{parent_ino} is used +to initialize directory entries for @file{.} and @file{..}, respectively. @end deftypefun @c ---------------------------------------------------------------------- @@ -559,6 +650,26 @@ contain valid block entries. @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 interates 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 ---------------------------------------------------------------------- @@ -568,9 +679,20 @@ contain valid block entries. @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 ---------------------------------------------------------------------- @@ -580,9 +702,61 @@ contain valid block entries. @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 ---------------------------------------------------------------------- @@ -738,7 +912,7 @@ Return the first inode or block which is stored in the bitmap. @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 first inode or block which is stored in the bitmap. +Return the last inode or block which is stored in the bitmap. @end deftypefun @@ -790,9 +964,16 @@ Return the first inode or block which is stored in the bitmap. @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 @@ -1050,9 +1231,14 @@ up-to-date ext2 shared library. /* 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