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-rw-r--r--fs/isofs/namei.c172
1 files changed, 172 insertions, 0 deletions
diff --git a/fs/isofs/namei.c b/fs/isofs/namei.c
new file mode 100644
index 000000000..7b543e6b6
--- /dev/null
+++ b/fs/isofs/namei.c
@@ -0,0 +1,172 @@
+/*
+ * linux/fs/isofs/namei.c
+ *
+ * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem.
+ *
+ * (C) 1991 Linus Torvalds - minix filesystem
+ */
+
+#include <linux/gfp.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;
+ qstr.name = compare;
+ qstr.len = dlen;
+ if (likely(!dentry->d_op))
+ return dentry->d_name.len != dlen || memcmp(dentry->d_name.name, compare, dlen);
+ return dentry->d_op->d_compare(NULL, NULL, dentry->d_name.len, dentry->d_name.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;
+ /* Basic sanity check, whether name doesn't exceed dir entry */
+ if (de_len < dlen + sizeof(struct iso_directory_record)) {
+ printk(KERN_NOTICE "iso9660: Corrupted directory entry"
+ " in block %lu of inode %lu\n", block,
+ dir->i_ino);
+ return 0;
+ }
+
+ 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 hide or showassoc,
+ * respectively, is set
+ */
+ match = 0;
+ if (dlen > 0 &&
+ (!sbi->s_hide ||
+ (!(de->flags[-sbi->s_high_sierra] & 1))) &&
+ (sbi->s_showassoc ||
+ (!(de->flags[-sbi->s_high_sierra] & 4)))) {
+ if (dpnt && (dlen > 1 || dpnt[0] > 1))
+ 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;
+ brelse(bh);
+ return 1;
+ }
+ }
+ brelse(bh);
+ return 0;
+}
+
+struct dentry *isofs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
+{
+ int found;
+ unsigned long uninitialized_var(block);
+ unsigned long uninitialized_var(offset);
+ struct inode *inode;
+ struct page *page;
+
+ page = alloc_page(GFP_USER);
+ if (!page)
+ return ERR_PTR(-ENOMEM);
+
+ found = isofs_find_entry(dir, dentry,
+ &block, &offset,
+ page_address(page),
+ 1024 + page_address(page));
+ __free_page(page);
+
+ inode = found ? isofs_iget(dir->i_sb, block, offset) : NULL;
+
+ return d_splice_alias(inode, dentry);
+}