2 * dirblock.c --- directory block routines.
4 * Copyright (C) 1995, 1996 Theodore Ts'o.
7 * This file may be redistributed under the terms of the GNU Library
8 * General Public License, version 2.
23 errcode_t ext2fs_read_dir_block3(ext2_filsys fs, blk64_t block,
24 void *buf, int flags EXT2FS_ATTR((unused)))
28 struct ext2_dir_entry *dirent;
29 unsigned int name_len, rec_len;
32 retval = io_channel_read_blk64(fs->io, block, 1, buf);
37 end = (char *) buf + fs->blocksize;
39 dirent = (struct ext2_dir_entry *) p;
40 #ifdef WORDS_BIGENDIAN
41 dirent->inode = ext2fs_swab32(dirent->inode);
42 dirent->rec_len = ext2fs_swab16(dirent->rec_len);
43 dirent->name_len = ext2fs_swab16(dirent->name_len);
45 name_len = dirent->name_len;
46 #ifdef WORDS_BIGENDIAN
47 if (flags & EXT2_DIRBLOCK_V2_STRUCT)
48 dirent->name_len = ext2fs_swab16(dirent->name_len);
50 if ((retval = ext2fs_get_rec_len(fs, dirent, &rec_len)) != 0)
52 if ((rec_len < 8) || (rec_len % 4)) {
54 retval = EXT2_ET_DIR_CORRUPTED;
55 } else if (((name_len & 0xFF) + 8) > rec_len)
56 retval = EXT2_ET_DIR_CORRUPTED;
63 * Compute the total directory entry data length.
64 * This includes the filename and an implicit NUL terminator (always present),
65 * and optional extensions. Each extension has a bit set in the high 4 bits of
66 * de->file_type, and the extension length is the first byte in each entry.
68 int ext2_get_dirent_dirdata_size(struct ext2_dir_entry_2 *de,
71 char *len = de->name + de->name_len + 1 /* NUL terminator */;
73 __u8 extra_data_flags = (de->file_type & ~EXT2_FT_MASK) >> 4;
76 while ((extra_data_flags & dirdata_flags) != 0) {
77 if (extra_data_flags & 1) {
78 if (dirdata_flags & 1)
83 extra_data_flags >>= 1;
87 /* add NUL terminator byte to dirdata length */
88 return dlen + (dlen != 0);
91 int ext2_get_dirent_size(struct ext2_dir_entry_2 *de)
93 return ext2_get_dirent_dirdata_size(de, ~EXT2_FT_MASK);
96 errcode_t ext2fs_read_dir_block2(ext2_filsys fs, blk_t block,
97 void *buf, int flags EXT2FS_ATTR((unused)))
99 return ext2fs_read_dir_block3(fs, block, buf, flags);
102 errcode_t ext2fs_read_dir_block(ext2_filsys fs, blk_t block,
105 return ext2fs_read_dir_block3(fs, block, buf, 0);
109 errcode_t ext2fs_write_dir_block3(ext2_filsys fs, blk64_t block,
110 void *inbuf, int flags EXT2FS_ATTR((unused)))
112 #ifdef WORDS_BIGENDIAN
116 unsigned int rec_len;
117 struct ext2_dir_entry *dirent;
119 retval = ext2fs_get_mem(fs->blocksize, &buf);
122 memcpy(buf, inbuf, fs->blocksize);
124 end = buf + fs->blocksize;
126 dirent = (struct ext2_dir_entry *) p;
127 if ((retval = ext2fs_get_rec_len(fs, dirent, &rec_len)) != 0)
131 ext2fs_free_mem(&buf);
132 return (EXT2_ET_DIR_CORRUPTED);
135 dirent->inode = ext2fs_swab32(dirent->inode);
136 dirent->rec_len = ext2fs_swab16(dirent->rec_len);
137 dirent->name_len = ext2fs_swab16(dirent->name_len);
139 if (flags & EXT2_DIRBLOCK_V2_STRUCT)
140 dirent->name_len = ext2fs_swab16(dirent->name_len);
142 retval = io_channel_write_blk64(fs->io, block, 1, buf);
143 ext2fs_free_mem(&buf);
146 return io_channel_write_blk64(fs->io, block, 1, (char *) inbuf);
150 errcode_t ext2fs_write_dir_block2(ext2_filsys fs, blk_t block,
151 void *inbuf, int flags EXT2FS_ATTR((unused)))
153 return ext2fs_write_dir_block3(fs, block, inbuf, flags);
156 errcode_t ext2fs_write_dir_block(ext2_filsys fs, blk_t block,
159 return ext2fs_write_dir_block3(fs, block, inbuf, 0);