diff options
Diffstat (limited to 'fs/isofs/namei.c')
| -rw-r--r-- | fs/isofs/namei.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/fs/isofs/namei.c b/fs/isofs/namei.c new file mode 100644 index 0000000..9569fc4 --- /dev/null +++ b/fs/isofs/namei.c @@ -0,0 +1,201 @@ +/* + * linux/fs/isofs/namei.c + * + * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem. + * + * (C) 1991 Linus Torvalds - minix filesystem + */ + +#include <linux/time.h> +#include <linux/iso_fs.h> +#include <linux/kernel.h> +#include <linux/string.h> +#include <linux/stat.h> +#include <linux/fcntl.h> +#include <linux/mm.h> +#include <linux/errno.h> +#include <linux/config.h> /* Joliet? */ +#include <linux/smp_lock.h> +#include <linux/buffer_head.h> +#include <linux/dcache.h> + +#include <asm/uaccess.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; +} |