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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 | /* * linux/fs/adfs/namei.c * * Copyright (C) 1997 Russell King */ #include <linux/errno.h> #include <linux/fs.h> #include <linux/adfs_fs.h> #include <linux/fcntl.h> #include <linux/sched.h> #include <linux/stat.h> #include <linux/string.h> #include <linux/locks.h> /* * NOTE! unlike strncmp, ext2_match returns 1 for success, 0 for failure */ static int adfs_match (int len, const char * const name, struct adfs_idir_entry *de) { int i; if (!de || len > ADFS_NAME_LEN) return 0; /* * "" means "." ---> so paths like "/usr/lib//libc.a" work */ if (!len && de->name_len == 1 && de->name[0] == '.' && de->name[1] == '\0') return 1; if (len != de->name_len) return 0; for (i = 0; i < len; i++) if ((de->name[i] ^ name[i]) & 0x5f) return 0; return 1; } static int adfs_find_entry (struct inode *dir, const char * const name, int namelen, struct adfs_idir_entry *ide) { struct super_block *sb; struct buffer_head *bh[4]; union adfs_dirtail dt; unsigned long parent_object_id, dir_object_id; int buffers, pos; sb = dir->i_sb; if (adfs_inode_validate (dir)) { adfs_error (sb, "adfs_find_entry", "invalid inode number: %lu", dir->i_ino); return 0; } if (!(buffers = adfs_dir_read (dir, bh))) { adfs_error (sb, "adfs_find_entry", "unable to read directory"); return 0; } if (adfs_dir_check (dir, bh, buffers, &dt)) { adfs_dir_free (bh, buffers); return 0; } parent_object_id = adfs_val (dt.new.dirparent, 3); dir_object_id = adfs_inode_objid (dir); if (namelen == 2 && name[0] == '.' && name[1] == '.') { ide->name_len = 2; ide->name[0] = ide->name[1] = '.'; ide->name[2] = '\0'; ide->inode_no = adfs_inode_generate (parent_object_id, 0); adfs_dir_free (bh, buffers); return 1; } pos = 5; do { if (!adfs_dir_get (sb, bh, buffers, pos, dir_object_id, ide)) break; if (adfs_match (namelen, name, ide)) { adfs_dir_free (bh, buffers); return pos; } pos += 26; } while (1); adfs_dir_free (bh, buffers); return 0; } struct dentry *adfs_lookup (struct inode *dir, struct dentry *dentry) { struct inode *inode = NULL; struct adfs_idir_entry de; unsigned long ino; if (dentry->d_name.len > ADFS_NAME_LEN) return ERR_PTR(-ENAMETOOLONG); if (adfs_find_entry (dir, dentry->d_name.name, dentry->d_name.len, &de)) { ino = de.inode_no; inode = iget (dir->i_sb, ino); if (!inode) return ERR_PTR(-EACCES); } d_add(dentry, inode); return NULL; } |