/* * linux/fs/isofs/namei.c * * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem. * * (C) 1991 Linus Torvalds - minix filesystem */ #include <linux/config.h> /* Joliet? */ #include <linux/smp_lock.h> #include "isofs.h" /* * ok, we cannot use strncmp, as the name is not in our data space. * Thus we'll have to use isofs_match. No big problem. Match also makes * some sanity tests. */ static int isofs_cmp(struct dentry * dentry, const char * compare, int dlen) { struct qstr qstr; if (!compare) return 1; /* check special "." and ".." files */ if (dlen == 1) { /* "." */ if (compare[0] == 0) { if (!dentry->d_name.len) return 0; compare = "."; } else if (compare[0] == 1) { compare = ".."; dlen = 2; } } qstr.name = compare; qstr.len = dlen; return dentry->d_op->d_compare(dentry, &dentry->d_name, &qstr); } /* * isofs_find_entry() * * finds an entry in the specified directory with the wanted name. It * returns the inode number of the found entry, or 0 on error. */ static unsigned long isofs_find_entry(struct inode *dir, struct dentry *dentry, unsigned long *block_rv, unsigned long* offset_rv, char * tmpname, struct iso_directory_record * tmpde) { unsigned long bufsize = ISOFS_BUFFER_SIZE(dir); unsigned char bufbits = ISOFS_BUFFER_BITS(dir); unsigned long block, f_pos, offset, block_saved, offset_saved; struct buffer_head * bh = NULL; struct isofs_sb_info *sbi = ISOFS_SB(dir->i_sb); if (!ISOFS_I(dir)->i_first_extent) return 0; f_pos = 0; offset = 0; block = 0; while (f_pos < dir->i_size) { struct iso_directory_record * de; int de_len, match, i, dlen; char *dpnt; if (!bh) { bh = isofs_bread(dir, block); if (!bh) return 0; } de = (struct iso_directory_record *) (bh->b_data + offset); de_len = *(unsigned char *) de; if (!de_len) { brelse(bh); bh = NULL; f_pos = (f_pos + ISOFS_BLOCK_SIZE) & ~(ISOFS_BLOCK_SIZE - 1); block = f_pos >> bufbits; offset = 0; continue; } block_saved = bh->b_blocknr; offset_saved = offset; offset += de_len; f_pos += de_len; /* Make sure we have a full directory entry */ if (offset >= bufsize) { int slop = bufsize - offset + de_len; memcpy(tmpde, de, slop); offset &= bufsize - 1; block++; brelse(bh); bh = NULL; if (offset) { bh = isofs_bread(dir, block); if (!bh) return 0; memcpy((void *) tmpde + slop, bh->b_data, offset); } de = tmpde; } dlen = de->name_len[0]; dpnt = de->name; if (sbi->s_rock && ((i = get_rock_ridge_filename(de, tmpname, dir)))) { dlen = i; /* possibly -1 */ dpnt = tmpname; #ifdef CONFIG_JOLIET } else if (sbi->s_joliet_level) { dlen = get_joliet_filename(de, tmpname, dir); dpnt = tmpname; #endif } else if (sbi->s_mapping == 'a') { dlen = get_acorn_filename(de, tmpname, dir); dpnt = tmpname; } else if (sbi->s_mapping == 'n') { dlen = isofs_name_translate(de, tmpname, dir); dpnt = tmpname; } /* * Skip hidden or associated files unless unhide is set */ match = 0; if (dlen > 0 && (!(de->flags[-sbi->s_high_sierra] & 5) || sbi->s_unhide == 'y')) { match = (isofs_cmp(dentry,dpnt,dlen) == 0); } if (match) { isofs_normalize_block_and_offset(de, &block_saved, &offset_saved); *block_rv = block_saved; *offset_rv = offset_saved; if (bh) brelse(bh); return 1; } } if (bh) brelse(bh); return 0; } struct dentry *isofs_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd) { int found; unsigned long block, offset; struct inode *inode; struct page *page; dentry->d_op = dir->i_sb->s_root->d_op; page = alloc_page(GFP_USER); if (!page) return ERR_PTR(-ENOMEM); lock_kernel(); found = isofs_find_entry(dir, dentry, &block, &offset, page_address(page), 1024 + page_address(page)); __free_page(page); inode = NULL; if (found) { inode = isofs_iget(dir->i_sb, block, offset); if (!inode) { unlock_kernel(); return ERR_PTR(-EACCES); } } unlock_kernel(); if (inode) return d_splice_alias(inode, dentry); d_add(dentry, inode); return NULL; }