2 * namei.c --- ext2fs directory lookup operations
4 * Copyright (C) 1993, 1994, 1994, 1995 Theodore Ts'o.
7 * This file may be redistributed under the terms of the GNU Library
8 * General Public License, version 2.
19 /* #define NAMEI_DEBUG */
25 static errcode_t open_namei(ext2_filsys fs, ext2_ino_t root, ext2_ino_t base,
26 const char *pathname, size_t pathlen, int follow,
27 int link_count, char *buf, ext2_ino_t *res_inode);
29 static errcode_t follow_link(ext2_filsys fs, ext2_ino_t root, ext2_ino_t dir,
30 ext2_ino_t inode, int link_count,
31 char *buf, ext2_ino_t *res_inode)
40 printf("follow_link: root=%lu, dir=%lu, inode=%lu, lc=%d\n",
41 root, dir, inode, link_count);
44 retval = ext2fs_read_inode (fs, inode, &ei);
45 if (retval) return retval;
46 if (!LINUX_S_ISLNK (ei.i_mode)) {
50 if (link_count++ >= EXT2FS_MAX_NESTED_LINKS)
51 return EXT2_ET_SYMLINK_LOOP;
53 if (ext2fs_is_fast_symlink(&ei))
54 pathname = (char *)&(ei.i_block[0]);
55 else if (ei.i_flags & EXT4_INLINE_DATA_FL) {
56 retval = ext2fs_get_memzero(ei.i_size, &buffer);
60 retval = ext2fs_inline_data_get(fs, inode,
63 ext2fs_free_mem(&buffer);
68 retval = ext2fs_bmap2(fs, inode, &ei, NULL, 0, 0, NULL, &blk);
72 retval = ext2fs_get_mem(fs->blocksize, &buffer);
76 retval = io_channel_read_blk64(fs->io, blk, 1, buffer);
78 ext2fs_free_mem(&buffer);
84 retval = open_namei(fs, root, dir, pathname, ei.i_size, 1,
85 link_count, buf, res_inode);
87 ext2fs_free_mem(&buffer);
92 * This routine interprets a pathname in the context of the current
93 * directory and the root directory, and returns the inode of the
94 * containing directory, and a pointer to the filename of the file
95 * (pointing into the pathname) and the length of the filename.
97 static errcode_t dir_namei(ext2_filsys fs, ext2_ino_t root, ext2_ino_t dir,
98 const char *pathname, int pathlen,
99 int link_count, char *buf,
100 const char **name, int *namelen,
101 ext2_ino_t *res_inode)
104 const char *thisname;
109 if ((c = *pathname) == '/') {
116 for (len=0; --pathlen >= 0;len++) {
123 retval = ext2fs_lookup (fs, dir, thisname, len, buf, &inode);
124 if (retval) return retval;
125 retval = follow_link (fs, root, dir, inode,
126 link_count, buf, &dir);
127 if (retval) return retval;
135 static errcode_t open_namei(ext2_filsys fs, ext2_ino_t root, ext2_ino_t base,
136 const char *pathname, size_t pathlen, int follow,
137 int link_count, char *buf, ext2_ino_t *res_inode)
139 const char *base_name;
141 ext2_ino_t dir, inode;
145 printf("open_namei: root=%lu, dir=%lu, path=%.*s, lc=%d\n",
146 root, base, pathlen, pathname, link_count);
148 retval = dir_namei(fs, root, base, pathname, pathlen,
149 link_count, buf, &base_name, &namelen, &dir);
150 if (retval) return retval;
151 if (!namelen) { /* special case: '/usr/' etc */
155 retval = ext2fs_lookup (fs, dir, base_name, namelen, buf, &inode);
159 retval = follow_link(fs, root, dir, inode, link_count,
165 printf("open_namei: (link_count=%d) returns %lu\n",
172 errcode_t ext2fs_namei(ext2_filsys fs, ext2_ino_t root, ext2_ino_t cwd,
173 const char *name, ext2_ino_t *inode)
178 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
180 retval = ext2fs_get_mem(fs->blocksize, &buf);
184 retval = open_namei(fs, root, cwd, name, strlen(name), 0, 0,
187 ext2fs_free_mem(&buf);
191 errcode_t ext2fs_namei_follow(ext2_filsys fs, ext2_ino_t root, ext2_ino_t cwd,
192 const char *name, ext2_ino_t *inode)
197 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
199 retval = ext2fs_get_mem(fs->blocksize, &buf);
203 retval = open_namei(fs, root, cwd, name, strlen(name), 1, 0,
206 ext2fs_free_mem(&buf);
210 errcode_t ext2fs_follow_link(ext2_filsys fs, ext2_ino_t root, ext2_ino_t cwd,
211 ext2_ino_t inode, ext2_ino_t *res_inode)
216 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
218 retval = ext2fs_get_mem(fs->blocksize, &buf);
222 retval = follow_link(fs, root, cwd, inode, 0, buf, res_inode);
224 ext2fs_free_mem(&buf);