[linux.git] / fs / isofs / rock.c

/*
 *  linux/fs/isofs/rock.c
 *
 *  (C) 1992, 1993  Eric Youngdale
 *
 *  Rock Ridge Extensions to iso9660
 */

#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/smp_lock.h>

#include "isofs.h"
#include "rock.h"

/*
 * These functions are designed to read the system areas of a directory record
 * and extract relevant information.  There are different functions provided
 * depending upon what information we need at the time.  One function fills
 * out an inode structure, a second one extracts a filename, a third one
 * returns a symbolic link name, and a fourth one returns the extent number
 * for the file.
 */

#define SIG(A,B) ((A) | ((B) << 8))	/* isonum_721() */

struct rock_state {
	void *buffer;
	unsigned char *chr;
	int len;
	int cont_size;
	int cont_extent;
	int cont_offset;
	struct inode *inode;
};

/*
 * This is a way of ensuring that we have something in the system
 * use fields that is compatible with Rock Ridge.  Return zero on success.
 */

static int check_sp(struct rock_ridge *rr, struct inode *inode)
{
	if (rr->u.SP.magic[0] != 0xbe)
		return -1;
	if (rr->u.SP.magic[1] != 0xef)
		return -1;
	ISOFS_SB(inode->i_sb)->s_rock_offset = rr->u.SP.skip;
	return 0;
}

static void setup_rock_ridge(struct iso_directory_record *de,
			struct inode *inode, struct rock_state *rs)
{
	rs->len = sizeof(struct iso_directory_record) + de->name_len[0];
	if (rs->len & 1)
		(rs->len)++;
	rs->chr = (unsigned char *)de + rs->len;
	rs->len = *((unsigned char *)de) - rs->len;
	if (rs->len < 0)
		rs->len = 0;

	if (ISOFS_SB(inode->i_sb)->s_rock_offset != -1) {
		rs->len -= ISOFS_SB(inode->i_sb)->s_rock_offset;
		rs->chr += ISOFS_SB(inode->i_sb)->s_rock_offset;
		if (rs->len < 0)
			rs->len = 0;
	}
}

static void init_rock_state(struct rock_state *rs, struct inode *inode)
{
	memset(rs, 0, sizeof(*rs));
	rs->inode = inode;
}

/*
 * Returns 0 if the caller should continue scanning, 1 if the scan must end
 * and -ve on error.
 */
static int rock_continue(struct rock_state *rs)
{
	int ret = 1;
	int blocksize = 1 << rs->inode->i_blkbits;
	const int min_de_size = offsetof(struct rock_ridge, u);

	kfree(rs->buffer);
	rs->buffer = NULL;

	if ((unsigned)rs->cont_offset > blocksize - min_de_size ||
	    (unsigned)rs->cont_size > blocksize ||
	    (unsigned)(rs->cont_offset + rs->cont_size) > blocksize) {
		printk(KERN_NOTICE "rock: corrupted directory entry. "
			"extent=%d, offset=%d, size=%d\n",
			rs->cont_extent, rs->cont_offset, rs->cont_size);
		ret = -EIO;
		goto out;
	}

	if (rs->cont_extent) {
		struct buffer_head *bh;

		rs->buffer = kmalloc(rs->cont_size, GFP_KERNEL);
		if (!rs->buffer) {
			ret = -ENOMEM;
			goto out;
		}
		ret = -EIO;
		bh = sb_bread(rs->inode->i_sb, rs->cont_extent);
		if (bh) {
			memcpy(rs->buffer, bh->b_data + rs->cont_offset,
					rs->cont_size);
			put_bh(bh);
			rs->chr = rs->buffer;
			rs->len = rs->cont_size;
			rs->cont_extent = 0;
			rs->cont_size = 0;
			rs->cont_offset = 0;
			return 0;
		}
		printk("Unable to read rock-ridge attributes\n");
	}
out:
	kfree(rs->buffer);
	rs->buffer = NULL;
	return ret;
}

/*
 * We think there's a record of type `sig' at rs->chr.  Parse the signature
 * and make sure that there's really room for a record of that type.
 */
static int rock_check_overflow(struct rock_state *rs, int sig)
{
	int len;

	switch (sig) {
	case SIG('S', 'P'):
		len = sizeof(struct SU_SP_s);
		break;
	case SIG('C', 'E'):
		len = sizeof(struct SU_CE_s);
		break;
	case SIG('E', 'R'):
		len = sizeof(struct SU_ER_s);
		break;
	case SIG('R', 'R'):
		len = sizeof(struct RR_RR_s);
		break;
	case SIG('P', 'X'):
		len = sizeof(struct RR_PX_s);
		break;
	case SIG('P', 'N'):
		len = sizeof(struct RR_PN_s);
		break;
	case SIG('S', 'L'):
		len = sizeof(struct RR_SL_s);
		break;
	case SIG('N', 'M'):
		len = sizeof(struct RR_NM_s);
		break;
	case SIG('C', 'L'):
		len = sizeof(struct RR_CL_s);
		break;
	case SIG('P', 'L'):
		len = sizeof(struct RR_PL_s);
		break;
	case SIG('T', 'F'):
		len = sizeof(struct RR_TF_s);
		break;
	case SIG('Z', 'F'):
		len = sizeof(struct RR_ZF_s);
		break;
	default:
		len = 0;
		break;
	}
	len += offsetof(struct rock_ridge, u);
	if (len > rs->len) {
		printk(KERN_NOTICE "rock: directory entry would overflow "
				"storage\n");
		printk(KERN_NOTICE "rock: sig=0x%02x, size=%d, remaining=%d\n",
				sig, len, rs->len);
		return -EIO;
	}
	return 0;
}

/*
 * return length of name field; 0: not found, -1: to be ignored
 */
int get_rock_ridge_filename(struct iso_directory_record *de,
			    char *retname, struct inode *inode)
{
	struct rock_state rs;
	struct rock_ridge *rr;
	int sig;
	int retnamlen = 0;
	int truncate = 0;
	int ret = 0;

	if (!ISOFS_SB(inode->i_sb)->s_rock)
		return 0;
	*retname = 0;

	init_rock_state(&rs, inode);
	setup_rock_ridge(de, inode, &rs);
repeat:

	while (rs.len > 2) { /* There may be one byte for padding somewhere */
		rr = (struct rock_ridge *)rs.chr;
		/*
		 * Ignore rock ridge info if rr->len is out of range, but
		 * don't return -EIO because that would make the file
		 * invisible.
		 */
		if (rr->len < 3)
			goto out;	/* Something got screwed up here */
		sig = isonum_721(rs.chr);
		if (rock_check_overflow(&rs, sig))
			goto eio;
		rs.chr += rr->len;
		rs.len -= rr->len;
		/*
		 * As above, just ignore the rock ridge info if rr->len
		 * is bogus.
		 */
		if (rs.len < 0)
			goto out;	/* Something got screwed up here */

		switch (sig) {
		case SIG('R', 'R'):
			if ((rr->u.RR.flags[0] & RR_NM) == 0)
				goto out;
			break;
		case SIG('S', 'P'):
			if (check_sp(rr, inode))
				goto out;
			break;
		case SIG('C', 'E'):
			rs.cont_extent = isonum_733(rr->u.CE.extent);
			rs.cont_offset = isonum_733(rr->u.CE.offset);
			rs.cont_size = isonum_733(rr->u.CE.size);
			break;
		case SIG('N', 'M'):
			if (truncate)
				break;
			if (rr->len < 5)
				break;
			/*
			 * If the flags are 2 or 4, this indicates '.' or '..'.
			 * We don't want to do anything with this, because it
			 * screws up the code that calls us.  We don't really
			 * care anyways, since we can just use the non-RR
			 * name.
			 */
			if (rr->u.NM.flags & 6)
				break;

			if (rr->u.NM.flags & ~1) {
				printk("Unsupported NM flag settings (%d)\n",
					rr->u.NM.flags);
				break;
			}
			if ((strlen(retname) + rr->len - 5) >= 254) {
				truncate = 1;
				break;
			}
			strncat(retname, rr->u.NM.name, rr->len - 5);
			retnamlen += rr->len - 5;
			break;
		case SIG('R', 'E'):
			kfree(rs.buffer);
			return -1;
		default:
			break;
		}
	}
	ret = rock_continue(&rs);
	if (ret == 0)
		goto repeat;
	if (ret == 1)
		return retnamlen; /* If 0, this file did not have a NM field */
out:
	kfree(rs.buffer);
	return ret;
eio:
	ret = -EIO;
	goto out;
}

static int
parse_rock_ridge_inode_internal(struct iso_directory_record *de,
				struct inode *inode, int regard_xa)
{
	int symlink_len = 0;
	int cnt, sig;
	struct inode *reloc;
	struct rock_ridge *rr;
	int rootflag;
	struct rock_state rs;
	int ret = 0;

	if (!ISOFS_SB(inode->i_sb)->s_rock)
		return 0;

	init_rock_state(&rs, inode);
	setup_rock_ridge(de, inode, &rs);
	if (regard_xa) {
		rs.chr += 14;
		rs.len -= 14;
		if (rs.len < 0)
			rs.len = 0;
	}

repeat:
	while (rs.len > 2) { /* There may be one byte for padding somewhere */
		rr = (struct rock_ridge *)rs.chr;
		/*
		 * Ignore rock ridge info if rr->len is out of range, but
		 * don't return -EIO because that would make the file
		 * invisible.
		 */
		if (rr->len < 3)
			goto out;	/* Something got screwed up here */
		sig = isonum_721(rs.chr);
		if (rock_check_overflow(&rs, sig))
			goto eio;
		rs.chr += rr->len;
		rs.len -= rr->len;
		/*
		 * As above, just ignore the rock ridge info if rr->len
		 * is bogus.
		 */
		if (rs.len < 0)
			goto out;	/* Something got screwed up here */

		switch (sig) {
#ifndef CONFIG_ZISOFS		/* No flag for SF or ZF */
		case SIG('R', 'R'):
			if ((rr->u.RR.flags[0] &
			     (RR_PX | RR_TF | RR_SL | RR_CL)) == 0)
				goto out;
			break;
#endif
		case SIG('S', 'P'):
			if (check_sp(rr, inode))
				goto out;
			break;
		case SIG('C', 'E'):
			rs.cont_extent = isonum_733(rr->u.CE.extent);
			rs.cont_offset = isonum_733(rr->u.CE.offset);
			rs.cont_size = isonum_733(rr->u.CE.size);
			break;
		case SIG('E', 'R'):
			ISOFS_SB(inode->i_sb)->s_rock = 1;
			printk(KERN_DEBUG "ISO 9660 Extensions: ");
			{
				int p;
				for (p = 0; p < rr->u.ER.len_id; p++)
					printk("%c", rr->u.ER.data[p]);
			}
			printk("\n");
			break;
		case SIG('P', 'X'):
			inode->i_mode = isonum_733(rr->u.PX.mode);
			inode->i_nlink = isonum_733(rr->u.PX.n_links);
			inode->i_uid = isonum_733(rr->u.PX.uid);
			inode->i_gid = isonum_733(rr->u.PX.gid);
			break;
		case SIG('P', 'N'):
			{
				int high, low;
				high = isonum_733(rr->u.PN.dev_high);
				low = isonum_733(rr->u.PN.dev_low);
				/*
				 * The Rock Ridge standard specifies that if
				 * sizeof(dev_t) <= 4, then the high field is
				 * unused, and the device number is completely
				 * stored in the low field.  Some writers may
				 * ignore this subtlety,
				 * and as a result we test to see if the entire
				 * device number is
				 * stored in the low field, and use that.
				 */
				if ((low & ~0xff) && high == 0) {
					inode->i_rdev =
					    MKDEV(low >> 8, low & 0xff);
				} else {
					inode->i_rdev =
					    MKDEV(high, low);
				}
			}
			break;
		case SIG('T', 'F'):
			/*
			 * Some RRIP writers incorrectly place ctime in the
			 * TF_CREATE field. Try to handle this correctly for
			 * either case.
			 */
			/* Rock ridge never appears on a High Sierra disk */
			cnt = 0;
			if (rr->u.TF.flags & TF_CREATE) {
				inode->i_ctime.tv_sec =
				    iso_date(rr->u.TF.times[cnt++].time,
					     0);
				inode->i_ctime.tv_nsec = 0;
			}
			if (rr->u.TF.flags & TF_MODIFY) {
				inode->i_mtime.tv_sec =
				    iso_date(rr->u.TF.times[cnt++].time,
					     0);
				inode->i_mtime.tv_nsec = 0;
			}
			if (rr->u.TF.flags & TF_ACCESS) {
				inode->i_atime.tv_sec =
				    iso_date(rr->u.TF.times[cnt++].time,
					     0);
				inode->i_atime.tv_nsec = 0;
			}
			if (rr->u.TF.flags & TF_ATTRIBUTES) {
				inode->i_ctime.tv_sec =
				    iso_date(rr->u.TF.times[cnt++].time,
					     0);
				inode->i_ctime.tv_nsec = 0;
			}
			break;
		case SIG('S', 'L'):
			{
				int slen;
				struct SL_component *slp;
				struct SL_component *oldslp;
				slen = rr->len - 5;
				slp = &rr->u.SL.link;
				inode->i_size = symlink_len;
				while (slen > 1) {
					rootflag = 0;
					switch (slp->flags & ~1) {
					case 0:
						inode->i_size +=
						    slp->len;
						break;
					case 2:
						inode->i_size += 1;
						break;
					case 4:
						inode->i_size += 2;
						break;
					case 8:
						rootflag = 1;
						inode->i_size += 1;
						break;
					default:
						printk("Symlink component flag "
							"not implemented\n");
					}
					slen -= slp->len + 2;
					oldslp = slp;
					slp = (struct SL_component *)
						(((char *)slp) + slp->len + 2);

					if (slen < 2) {
						if (((rr->u.SL.
						      flags & 1) != 0)
						    &&
						    ((oldslp->
						      flags & 1) == 0))
							inode->i_size +=
							    1;
						break;
					}

					/*
					 * If this component record isn't
					 * continued, then append a '/'.
					 */
					if (!rootflag
					    && (oldslp->flags & 1) == 0)
						inode->i_size += 1;
				}
			}
			symlink_len = inode->i_size;
			break;
		case SIG('R', 'E'):
			printk(KERN_WARNING "Attempt to read inode for "
					"relocated directory\n");
			goto out;
		case SIG('C', 'L'):
			ISOFS_I(inode)->i_first_extent =
			    isonum_733(rr->u.CL.location);
			reloc =
			    isofs_iget(inode->i_sb,
				       ISOFS_I(inode)->i_first_extent,
				       0);
			if (IS_ERR(reloc)) {
				ret = PTR_ERR(reloc);
				goto out;
			}
			inode->i_mode = reloc->i_mode;
			inode->i_nlink = reloc->i_nlink;
			inode->i_uid = reloc->i_uid;
			inode->i_gid = reloc->i_gid;
			inode->i_rdev = reloc->i_rdev;
			inode->i_size = reloc->i_size;
			inode->i_blocks = reloc->i_blocks;
			inode->i_atime = reloc->i_atime;
			inode->i_ctime = reloc->i_ctime;
			inode->i_mtime = reloc->i_mtime;
			iput(reloc);
			break;
#ifdef CONFIG_ZISOFS
		case SIG('Z', 'F'): {
			int algo;

			if (ISOFS_SB(inode->i_sb)->s_nocompress)
				break;
			algo = isonum_721(rr->u.ZF.algorithm);
			if (algo == SIG('p', 'z')) {
				int block_shift =
					isonum_711(&rr->u.ZF.parms[1]);
				if (block_shift > 17) {
					printk(KERN_WARNING "isofs: "
						"Can't handle ZF block "
						"size of 2^%d\n",
						block_shift);
				} else {
					/*
					 * Note: we don't change
					 * i_blocks here
					 */
					ISOFS_I(inode)->i_file_format =
						isofs_file_compressed;
					/*
					 * Parameters to compression
					 * algorithm (header size,
					 * block size)
					 */
					ISOFS_I(inode)->i_format_parm[0] =
						isonum_711(&rr->u.ZF.parms[0]);
					ISOFS_I(inode)->i_format_parm[1] =
						isonum_711(&rr->u.ZF.parms[1]);
					inode->i_size =
					    isonum_733(rr->u.ZF.
						       real_size);
				}
			} else {
				printk(KERN_WARNING
				       "isofs: Unknown ZF compression "
						"algorithm: %c%c\n",
				       rr->u.ZF.algorithm[0],
				       rr->u.ZF.algorithm[1]);
			}
			break;
		}
#endif
		default:
			break;
		}
	}
	ret = rock_continue(&rs);
	if (ret == 0)
		goto repeat;
	if (ret == 1)
		ret = 0;
out:
	kfree(rs.buffer);
	return ret;
eio:
	ret = -EIO;
	goto out;
}

static char *get_symlink_chunk(char *rpnt, struct rock_ridge *rr, char *plimit)
{
	int slen;
	int rootflag;
	struct SL_component *oldslp;
	struct SL_component *slp;
	slen = rr->len - 5;
	slp = &rr->u.SL.link;
	while (slen > 1) {
		rootflag = 0;
		switch (slp->flags & ~1) {
		case 0:
			if (slp->len > plimit - rpnt)
				return NULL;
			memcpy(rpnt, slp->text, slp->len);
			rpnt += slp->len;
			break;
		case 2:
			if (rpnt >= plimit)
				return NULL;
			*rpnt++ = '.';
			break;
		case 4:
			if (2 > plimit - rpnt)
				return NULL;
			*rpnt++ = '.';
			*rpnt++ = '.';
			break;
		case 8:
			if (rpnt >= plimit)
				return NULL;
			rootflag = 1;
			*rpnt++ = '/';
			break;
		default:
			printk("Symlink component flag not implemented (%d)\n",
			       slp->flags);
		}
		slen -= slp->len + 2;
		oldslp = slp;
		slp = (struct SL_component *)((char *)slp + slp->len + 2);

		if (slen < 2) {
			/*
			 * If there is another SL record, and this component
			 * record isn't continued, then add a slash.
			 */
			if ((!rootflag) && (rr->u.SL.flags & 1) &&
			    !(oldslp->flags & 1)) {
				if (rpnt >= plimit)
					return NULL;
				*rpnt++ = '/';
			}
			break;
		}

		/*
		 * If this component record isn't continued, then append a '/'.
		 */
		if (!rootflag && !(oldslp->flags & 1)) {
			if (rpnt >= plimit)
				return NULL;
			*rpnt++ = '/';
		}
	}
	return rpnt;
}

int parse_rock_ridge_inode(struct iso_directory_record *de, struct inode *inode)
{
	int result = parse_rock_ridge_inode_internal(de, inode, 0);

	/*
	 * if rockridge flag was reset and we didn't look for attributes
	 * behind eventual XA attributes, have a look there
	 */
	if ((ISOFS_SB(inode->i_sb)->s_rock_offset == -1)
	    && (ISOFS_SB(inode->i_sb)->s_rock == 2)) {
		result = parse_rock_ridge_inode_internal(de, inode, 14);
	}
	return result;
}

/*
 * readpage() for symlinks: reads symlink contents into the page and either
 * makes it uptodate and returns 0 or returns error (-EIO)
 */
static int rock_ridge_symlink_readpage(struct file *file, struct page *page)
{
	struct inode *inode = page->mapping->host;
	struct iso_inode_info *ei = ISOFS_I(inode);
	char *link = kmap(page);
	unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
	struct buffer_head *bh;
	char *rpnt = link;
	unsigned char *pnt;
	struct iso_directory_record *raw_de;
	unsigned long block, offset;
	int sig;
	struct rock_ridge *rr;
	struct rock_state rs;
	int ret;

	if (!ISOFS_SB(inode->i_sb)->s_rock)
		goto error;

	init_rock_state(&rs, inode);
	block = ei->i_iget5_block;
	lock_kernel();
	bh = sb_bread(inode->i_sb, block);
	if (!bh)
		goto out_noread;

	offset = ei->i_iget5_offset;
	pnt = (unsigned char *)bh->b_data + offset;

	raw_de = (struct iso_directory_record *)pnt;

	/*
	 * If we go past the end of the buffer, there is some sort of error.
	 */
	if (offset + *pnt > bufsize)
		goto out_bad_span;

	/*
	 * Now test for possible Rock Ridge extensions which will override
	 * some of these numbers in the inode structure.
	 */

	setup_rock_ridge(raw_de, inode, &rs);

repeat:
	while (rs.len > 2) { /* There may be one byte for padding somewhere */
		rr = (struct rock_ridge *)rs.chr;
		if (rr->len < 3)
			goto out;	/* Something got screwed up here */
		sig = isonum_721(rs.chr);
		if (rock_check_overflow(&rs, sig))
			goto out;
		rs.chr += rr->len;
		rs.len -= rr->len;
		if (rs.len < 0)
			goto out;	/* corrupted isofs */

		switch (sig) {
		case SIG('R', 'R'):
			if ((rr->u.RR.flags[0] & RR_SL) == 0)
				goto out;
			break;
		case SIG('S', 'P'):
			if (check_sp(rr, inode))
				goto out;
			break;
		case SIG('S', 'L'):
			rpnt = get_symlink_chunk(rpnt, rr,
						 link + (PAGE_SIZE - 1));
			if (rpnt == NULL)
				goto out;
			break;
		case SIG('C', 'E'):
			/* This tells is if there is a continuation record */
			rs.cont_extent = isonum_733(rr->u.CE.extent);
			rs.cont_offset = isonum_733(rr->u.CE.offset);
			rs.cont_size = isonum_733(rr->u.CE.size);
		default:
			break;
		}
	}
	ret = rock_continue(&rs);
	if (ret == 0)
		goto repeat;
	if (ret < 0)
		goto fail;

	if (rpnt == link)
		goto fail;
	brelse(bh);
	*rpnt = '\0';
	unlock_kernel();
	SetPageUptodate(page);
	kunmap(page);
	unlock_page(page);
	return 0;

	/* error exit from macro */
out:
	kfree(rs.buffer);
	goto fail;
out_noread:
	printk("unable to read i-node block");
	goto fail;
out_bad_span:
	printk("symlink spans iso9660 blocks\n");
fail:
	brelse(bh);
	unlock_kernel();
error:
	SetPageError(page);
	kunmap(page);
	unlock_page(page);
	return -EIO;
}

const struct address_space_operations isofs_symlink_aops = {
	.readpage = rock_ridge_symlink_readpage
};
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/isofs/rock.c
	3	*
	4	* (C) 1992, 1993 Eric Youngdale
	5	*
	6	* Rock Ridge Extensions to iso9660
	7	*/
	8
1da177e4 LT	9	#include <linux/slab.h>
	10	#include <linux/pagemap.h>
	11	#include <linux/smp_lock.h>
1da177e4	12
94f2f715	13	#include "isofs.h"
1da177e4 LT	14	#include "rock.h"
1da177e4 LT	15
7373909d AM	16	/*
7373909d AM	17	* These functions are designed to read the system areas of a directory record
1da177e4 LT	18	* and extract relevant information. There are different functions provided
	19	* depending upon what information we need at the time. One function fills
	20	* out an inode structure, a second one extracts a filename, a third one
	21	* returns a symbolic link name, and a fourth one returns the extent number
7373909d AM	22	* for the file.
7373909d AM	23	*/
1da177e4	24
1d372116	25	#define SIG(A,B) ((A) \| ((B) << 8)) /* isonum_721() */
1da177e4	26
ba40aaf0 AM	27	struct rock_state {
	28	void *buffer;
	29	unsigned char *chr;
	30	int len;
	31	int cont_size;
	32	int cont_extent;
	33	int cont_offset;
	34	struct inode *inode;
	35	};
	36
12121714 AM	37	/*
12121714 AM	38	* This is a way of ensuring that we have something in the system
7373909d	39	* use fields that is compatible with Rock Ridge. Return zero on success.
12121714 AM	40	*/
	41
	42	static int check_sp(struct rock_ridge rr, struct inode inode)
	43	{
	44	if (rr->u.SP.magic[0] != 0xbe)
	45	return -1;
	46	if (rr->u.SP.magic[1] != 0xef)
	47	return -1;
	48	ISOFS_SB(inode->i_sb)->s_rock_offset = rr->u.SP.skip;
	49	return 0;
	50	}
	51
76ab07eb	52	static void setup_rock_ridge(struct iso_directory_record *de,
ba40aaf0	53	struct inode inode, struct rock_state rs)
76ab07eb	54	{
ba40aaf0 AM	55	rs->len = sizeof(struct iso_directory_record) + de->name_len[0];
	56	if (rs->len & 1)
	57	(rs->len)++;
	58	rs->chr = (unsigned char *)de + rs->len;
	59	rs->len = ((unsigned char )de) - rs->len;
	60	if (rs->len < 0)
	61	rs->len = 0;
76ab07eb AM	62
76ab07eb AM	63	if (ISOFS_SB(inode->i_sb)->s_rock_offset != -1) {
ba40aaf0 AM	64	rs->len -= ISOFS_SB(inode->i_sb)->s_rock_offset;
	65	rs->chr += ISOFS_SB(inode->i_sb)->s_rock_offset;
	66	if (rs->len < 0)
	67	rs->len = 0;
76ab07eb	68	}
1d372116	69	}
1da177e4	70
ba40aaf0 AM	71	static void init_rock_state(struct rock_state rs, struct inode inode)
	72	{
	73	memset(rs, 0, sizeof(*rs));
	74	rs->inode = inode;
	75	}
	76
	77	/*
	78	* Returns 0 if the caller should continue scanning, 1 if the scan must end
	79	* and -ve on error.
	80	*/
	81	static int rock_continue(struct rock_state *rs)
	82	{
	83	int ret = 1;
e595447e AM	84	int blocksize = 1 << rs->inode->i_blkbits;
e595447e AM	85	const int min_de_size = offsetof(struct rock_ridge, u);
ba40aaf0 AM	86
	87	kfree(rs->buffer);
	88	rs->buffer = NULL;
e595447e AM	89
	90	if ((unsigned)rs->cont_offset > blocksize - min_de_size \|\|
	91	(unsigned)rs->cont_size > blocksize \|\|
	92	(unsigned)(rs->cont_offset + rs->cont_size) > blocksize) {
	93	printk(KERN_NOTICE "rock: corrupted directory entry. "
	94	"extent=%d, offset=%d, size=%d\n",
	95	rs->cont_extent, rs->cont_offset, rs->cont_size);
	96	ret = -EIO;
	97	goto out;
	98	}
	99
ba40aaf0 AM	100	if (rs->cont_extent) {
	101	struct buffer_head *bh;
	102
	103	rs->buffer = kmalloc(rs->cont_size, GFP_KERNEL);
	104	if (!rs->buffer) {
	105	ret = -ENOMEM;
	106	goto out;
	107	}
	108	ret = -EIO;
	109	bh = sb_bread(rs->inode->i_sb, rs->cont_extent);
	110	if (bh) {
	111	memcpy(rs->buffer, bh->b_data + rs->cont_offset,
	112	rs->cont_size);
	113	put_bh(bh);
	114	rs->chr = rs->buffer;
	115	rs->len = rs->cont_size;
	116	rs->cont_extent = 0;
	117	rs->cont_size = 0;
	118	rs->cont_offset = 0;
	119	return 0;
	120	}
	121	printk("Unable to read rock-ridge attributes\n");
	122	}
	123	out:
	124	kfree(rs->buffer);
	125	rs->buffer = NULL;
	126	return ret;
	127	}
1da177e4	128
f2966632 AM	129	/*
	130	* We think there's a record of type `sig' at rs->chr. Parse the signature
	131	* and make sure that there's really room for a record of that type.
	132	*/
	133	static int rock_check_overflow(struct rock_state *rs, int sig)
	134	{
	135	int len;
	136
	137	switch (sig) {
	138	case SIG('S', 'P'):
	139	len = sizeof(struct SU_SP_s);
	140	break;
	141	case SIG('C', 'E'):
	142	len = sizeof(struct SU_CE_s);
	143	break;
	144	case SIG('E', 'R'):
	145	len = sizeof(struct SU_ER_s);
	146	break;
	147	case SIG('R', 'R'):
	148	len = sizeof(struct RR_RR_s);
	149	break;
	150	case SIG('P', 'X'):
	151	len = sizeof(struct RR_PX_s);
	152	break;
	153	case SIG('P', 'N'):
	154	len = sizeof(struct RR_PN_s);
	155	break;
	156	case SIG('S', 'L'):
	157	len = sizeof(struct RR_SL_s);
	158	break;
	159	case SIG('N', 'M'):
	160	len = sizeof(struct RR_NM_s);
	161	break;
	162	case SIG('C', 'L'):
	163	len = sizeof(struct RR_CL_s);
	164	break;
	165	case SIG('P', 'L'):
	166	len = sizeof(struct RR_PL_s);
	167	break;
	168	case SIG('T', 'F'):
	169	len = sizeof(struct RR_TF_s);
	170	break;
	171	case SIG('Z', 'F'):
	172	len = sizeof(struct RR_ZF_s);
	173	break;
	174	default:
	175	len = 0;
	176	break;
	177	}
	178	len += offsetof(struct rock_ridge, u);
	179	if (len > rs->len) {
	180	printk(KERN_NOTICE "rock: directory entry would overflow "
	181	"storage\n");
	182	printk(KERN_NOTICE "rock: sig=0x%02x, size=%d, remaining=%d\n",
	183	sig, len, rs->len);
	184	return -EIO;
	185	}
	186	return 0;
	187	}
	188
7373909d AM	189	/*
	190	* return length of name field; 0: not found, -1: to be ignored
	191	*/
1d372116 AM	192	int get_rock_ridge_filename(struct iso_directory_record *de,
1d372116 AM	193	char retname, struct inode inode)
1da177e4	194	{
ba40aaf0	195	struct rock_state rs;
7fa393a1 AM	196	struct rock_ridge *rr;
	197	int sig;
	198	int retnamlen = 0;
	199	int truncate = 0;
ba40aaf0	200	int ret = 0;
1da177e4	201
1d372116 AM	202	if (!ISOFS_SB(inode->i_sb)->s_rock)
	203	return 0;
	204	*retname = 0;
	205
ba40aaf0 AM	206	init_rock_state(&rs, inode);
ba40aaf0 AM	207	setup_rock_ridge(de, inode, &rs);
7fa393a1 AM	208	repeat:
7fa393a1 AM	209
ba40aaf0 AM	210	while (rs.len > 2) { /* There may be one byte for padding somewhere */
ba40aaf0 AM	211	rr = (struct rock_ridge *)rs.chr;
c0a1633b AG	212	/*
	213	* Ignore rock ridge info if rr->len is out of range, but
	214	* don't return -EIO because that would make the file
	215	* invisible.
	216	*/
7fa393a1 AM	217	if (rr->len < 3)
7fa393a1 AM	218	goto out; /* Something got screwed up here */
ba40aaf0	219	sig = isonum_721(rs.chr);
f2966632 AM	220	if (rock_check_overflow(&rs, sig))
f2966632 AM	221	goto eio;
ba40aaf0 AM	222	rs.chr += rr->len;
ba40aaf0 AM	223	rs.len -= rr->len;
c0a1633b AG	224	/*
	225	* As above, just ignore the rock ridge info if rr->len
	226	* is bogus.
	227	*/
ba40aaf0	228	if (rs.len < 0)
c0a1633b	229	goto out; /* Something got screwed up here */
7fa393a1 AM	230
	231	switch (sig) {
	232	case SIG('R', 'R'):
	233	if ((rr->u.RR.flags[0] & RR_NM) == 0)
	234	goto out;
	235	break;
	236	case SIG('S', 'P'):
12121714 AM	237	if (check_sp(rr, inode))
12121714 AM	238	goto out;
7fa393a1 AM	239	break;
7fa393a1 AM	240	case SIG('C', 'E'):
ba40aaf0 AM	241	rs.cont_extent = isonum_733(rr->u.CE.extent);
	242	rs.cont_offset = isonum_733(rr->u.CE.offset);
	243	rs.cont_size = isonum_733(rr->u.CE.size);
7fa393a1 AM	244	break;
	245	case SIG('N', 'M'):
	246	if (truncate)
1d372116	247	break;
7fa393a1	248	if (rr->len < 5)
1d372116	249	break;
7fa393a1 AM	250	/*
	251	* If the flags are 2 or 4, this indicates '.' or '..'.
	252	* We don't want to do anything with this, because it
	253	* screws up the code that calls us. We don't really
	254	* care anyways, since we can just use the non-RR
	255	* name.
	256	*/
	257	if (rr->u.NM.flags & 6)
1d372116	258	break;
1d372116	259
7fa393a1 AM	260	if (rr->u.NM.flags & ~1) {
	261	printk("Unsupported NM flag settings (%d)\n",
	262	rr->u.NM.flags);
1d372116	263	break;
7fa393a1 AM	264	}
	265	if ((strlen(retname) + rr->len - 5) >= 254) {
	266	truncate = 1;
1d372116 AM	267	break;
1d372116 AM	268	}
7fa393a1 AM	269	strncat(retname, rr->u.NM.name, rr->len - 5);
	270	retnamlen += rr->len - 5;
	271	break;
	272	case SIG('R', 'E'):
ba40aaf0	273	kfree(rs.buffer);
7fa393a1 AM	274	return -1;
	275	default:
	276	break;
1d372116	277	}
1da177e4	278	}
ba40aaf0 AM	279	ret = rock_continue(&rs);
	280	if (ret == 0)
	281	goto repeat;
	282	if (ret == 1)
	283	return retnamlen; /* If 0, this file did not have a NM field */
7fa393a1	284	out:
ba40aaf0 AM	285	kfree(rs.buffer);
ba40aaf0 AM	286	return ret;
f2966632 AM	287	eio:
	288	ret = -EIO;
	289	goto out;
1da177e4 LT	290	}
	291
	292	static int
	293	parse_rock_ridge_inode_internal(struct iso_directory_record *de,
	294	struct inode *inode, int regard_xa)
	295	{
1d372116	296	int symlink_len = 0;
7fa393a1 AM	297	int cnt, sig;
	298	struct inode *reloc;
	299	struct rock_ridge *rr;
	300	int rootflag;
ba40aaf0 AM	301	struct rock_state rs;
ba40aaf0 AM	302	int ret = 0;
1d372116 AM	303
	304	if (!ISOFS_SB(inode->i_sb)->s_rock)
	305	return 0;
	306
ba40aaf0 AM	307	init_rock_state(&rs, inode);
ba40aaf0 AM	308	setup_rock_ridge(de, inode, &rs);
1d372116	309	if (regard_xa) {
ba40aaf0 AM	310	rs.chr += 14;
	311	rs.len -= 14;
	312	if (rs.len < 0)
	313	rs.len = 0;
1d372116 AM	314	}
1d372116 AM	315
7fa393a1	316	repeat:
ba40aaf0 AM	317	while (rs.len > 2) { /* There may be one byte for padding somewhere */
ba40aaf0 AM	318	rr = (struct rock_ridge *)rs.chr;
c0a1633b AG	319	/*
	320	* Ignore rock ridge info if rr->len is out of range, but
	321	* don't return -EIO because that would make the file
	322	* invisible.
	323	*/
7fa393a1 AM	324	if (rr->len < 3)
7fa393a1 AM	325	goto out; /* Something got screwed up here */
ba40aaf0	326	sig = isonum_721(rs.chr);
f2966632 AM	327	if (rock_check_overflow(&rs, sig))
f2966632 AM	328	goto eio;
ba40aaf0 AM	329	rs.chr += rr->len;
ba40aaf0 AM	330	rs.len -= rr->len;
c0a1633b AG	331	/*
	332	* As above, just ignore the rock ridge info if rr->len
	333	* is bogus.
	334	*/
ba40aaf0	335	if (rs.len < 0)
c0a1633b	336	goto out; /* Something got screwed up here */
7fa393a1 AM	337
7fa393a1 AM	338	switch (sig) {
1da177e4	339	#ifndef CONFIG_ZISOFS /* No flag for SF or ZF */
7fa393a1 AM	340	case SIG('R', 'R'):
	341	if ((rr->u.RR.flags[0] &
	342	(RR_PX \| RR_TF \| RR_SL \| RR_CL)) == 0)
	343	goto out;
	344	break;
1da177e4	345	#endif
7fa393a1	346	case SIG('S', 'P'):
12121714 AM	347	if (check_sp(rr, inode))
12121714 AM	348	goto out;
7fa393a1 AM	349	break;
7fa393a1 AM	350	case SIG('C', 'E'):
ba40aaf0 AM	351	rs.cont_extent = isonum_733(rr->u.CE.extent);
	352	rs.cont_offset = isonum_733(rr->u.CE.offset);
	353	rs.cont_size = isonum_733(rr->u.CE.size);
7fa393a1 AM	354	break;
	355	case SIG('E', 'R'):
	356	ISOFS_SB(inode->i_sb)->s_rock = 1;
	357	printk(KERN_DEBUG "ISO 9660 Extensions: ");
	358	{
	359	int p;
	360	for (p = 0; p < rr->u.ER.len_id; p++)
	361	printk("%c", rr->u.ER.data[p]);
	362	}
	363	printk("\n");
	364	break;
	365	case SIG('P', 'X'):
	366	inode->i_mode = isonum_733(rr->u.PX.mode);
	367	inode->i_nlink = isonum_733(rr->u.PX.n_links);
	368	inode->i_uid = isonum_733(rr->u.PX.uid);
	369	inode->i_gid = isonum_733(rr->u.PX.gid);
	370	break;
	371	case SIG('P', 'N'):
	372	{
	373	int high, low;
	374	high = isonum_733(rr->u.PN.dev_high);
	375	low = isonum_733(rr->u.PN.dev_low);
	376	/*
	377	* The Rock Ridge standard specifies that if
	378	* sizeof(dev_t) <= 4, then the high field is
	379	* unused, and the device number is completely
	380	* stored in the low field. Some writers may
	381	* ignore this subtlety,
	382	* and as a result we test to see if the entire
	383	* device number is
	384	* stored in the low field, and use that.
	385	*/
	386	if ((low & ~0xff) && high == 0) {
	387	inode->i_rdev =
	388	MKDEV(low >> 8, low & 0xff);
	389	} else {
	390	inode->i_rdev =
	391	MKDEV(high, low);
1d372116	392	}
7fa393a1 AM	393	}
	394	break;
	395	case SIG('T', 'F'):
	396	/*
	397	* Some RRIP writers incorrectly place ctime in the
	398	* TF_CREATE field. Try to handle this correctly for
	399	* either case.
	400	*/
	401	/* Rock ridge never appears on a High Sierra disk */
	402	cnt = 0;
	403	if (rr->u.TF.flags & TF_CREATE) {
	404	inode->i_ctime.tv_sec =
	405	iso_date(rr->u.TF.times[cnt++].time,
	406	0);
	407	inode->i_ctime.tv_nsec = 0;
	408	}
	409	if (rr->u.TF.flags & TF_MODIFY) {
	410	inode->i_mtime.tv_sec =
	411	iso_date(rr->u.TF.times[cnt++].time,
	412	0);
	413	inode->i_mtime.tv_nsec = 0;
	414	}
	415	if (rr->u.TF.flags & TF_ACCESS) {
	416	inode->i_atime.tv_sec =
	417	iso_date(rr->u.TF.times[cnt++].time,
	418	0);
	419	inode->i_atime.tv_nsec = 0;
	420	}
	421	if (rr->u.TF.flags & TF_ATTRIBUTES) {
	422	inode->i_ctime.tv_sec =
	423	iso_date(rr->u.TF.times[cnt++].time,
	424	0);
	425	inode->i_ctime.tv_nsec = 0;
	426	}
	427	break;
	428	case SIG('S', 'L'):
	429	{
	430	int slen;
	431	struct SL_component *slp;
	432	struct SL_component *oldslp;
	433	slen = rr->len - 5;
	434	slp = &rr->u.SL.link;
	435	inode->i_size = symlink_len;
	436	while (slen > 1) {
	437	rootflag = 0;
	438	switch (slp->flags & ~1) {
	439	case 0:
	440	inode->i_size +=
	441	slp->len;
	442	break;
	443	case 2:
	444	inode->i_size += 1;
	445	break;
	446	case 4:
	447	inode->i_size += 2;
	448	break;
	449	case 8:
	450	rootflag = 1;
	451	inode->i_size += 1;
	452	break;
	453	default:
	454	printk("Symlink component flag "
	455	"not implemented\n");
1d372116	456	}
7fa393a1 AM	457	slen -= slp->len + 2;
	458	oldslp = slp;
	459	slp = (struct SL_component *)
	460	(((char *)slp) + slp->len + 2);
	461
	462	if (slen < 2) {
	463	if (((rr->u.SL.
	464	flags & 1) != 0)
	465	&&
	466	((oldslp->
	467	flags & 1) == 0))
1d372116	468	inode->i_size +=
7fa393a1 AM	469	1;
7fa393a1 AM	470	break;
1d372116	471	}
7fa393a1 AM	472
	473	/*
	474	* If this component record isn't
	475	* continued, then append a '/'.
	476	*/
	477	if (!rootflag
	478	&& (oldslp->flags & 1) == 0)
	479	inode->i_size += 1;
1d372116	480	}
7fa393a1 AM	481	}
	482	symlink_len = inode->i_size;
	483	break;
	484	case SIG('R', 'E'):
	485	printk(KERN_WARNING "Attempt to read inode for "
	486	"relocated directory\n");
	487	goto out;
	488	case SIG('C', 'L'):
	489	ISOFS_I(inode)->i_first_extent =
	490	isonum_733(rr->u.CL.location);
	491	reloc =
	492	isofs_iget(inode->i_sb,
	493	ISOFS_I(inode)->i_first_extent,
	494	0);
c4386c83 DH	495	if (IS_ERR(reloc)) {
c4386c83 DH	496	ret = PTR_ERR(reloc);
1d372116	497	goto out;
c4386c83	498	}
7fa393a1 AM	499	inode->i_mode = reloc->i_mode;
	500	inode->i_nlink = reloc->i_nlink;
	501	inode->i_uid = reloc->i_uid;
	502	inode->i_gid = reloc->i_gid;
	503	inode->i_rdev = reloc->i_rdev;
	504	inode->i_size = reloc->i_size;
	505	inode->i_blocks = reloc->i_blocks;
	506	inode->i_atime = reloc->i_atime;
	507	inode->i_ctime = reloc->i_ctime;
	508	inode->i_mtime = reloc->i_mtime;
	509	iput(reloc);
	510	break;
1da177e4	511	#ifdef CONFIG_ZISOFS
7fa393a1 AM	512	case SIG('Z', 'F'): {
	513	int algo;
	514
	515	if (ISOFS_SB(inode->i_sb)->s_nocompress)
1d372116	516	break;
7fa393a1 AM	517	algo = isonum_721(rr->u.ZF.algorithm);
	518	if (algo == SIG('p', 'z')) {
	519	int block_shift =
	520	isonum_711(&rr->u.ZF.parms[1]);
59bc0552	521	if (block_shift > 17) {
7fa393a1 AM	522	printk(KERN_WARNING "isofs: "
	523	"Can't handle ZF block "
	524	"size of 2^%d\n",
	525	block_shift);
	526	} else {
	527	/*
	528	* Note: we don't change
	529	* i_blocks here
	530	*/
	531	ISOFS_I(inode)->i_file_format =
	532	isofs_file_compressed;
	533	/*
	534	* Parameters to compression
	535	* algorithm (header size,
	536	* block size)
	537	*/
	538	ISOFS_I(inode)->i_format_parm[0] =
	539	isonum_711(&rr->u.ZF.parms[0]);
	540	ISOFS_I(inode)->i_format_parm[1] =
	541	isonum_711(&rr->u.ZF.parms[1]);
	542	inode->i_size =
	543	isonum_733(rr->u.ZF.
	544	real_size);
	545	}
	546	} else {
	547	printk(KERN_WARNING
	548	"isofs: Unknown ZF compression "
	549	"algorithm: %c%c\n",
	550	rr->u.ZF.algorithm[0],
	551	rr->u.ZF.algorithm[1]);
1d372116	552	}
7fa393a1 AM	553	break;
	554	}
	555	#endif
	556	default:
	557	break;
1d372116 AM	558	}
1d372116 AM	559	}
ba40aaf0 AM	560	ret = rock_continue(&rs);
	561	if (ret == 0)
	562	goto repeat;
	563	if (ret == 1)
	564	ret = 0;
7fa393a1	565	out:
ba40aaf0 AM	566	kfree(rs.buffer);
ba40aaf0 AM	567	return ret;
f2966632 AM	568	eio:
	569	ret = -EIO;
	570	goto out;
1da177e4 LT	571	}
	572
	573	static char get_symlink_chunk(char rpnt, struct rock_ridge rr, char plimit)
	574	{
	575	int slen;
	576	int rootflag;
	577	struct SL_component *oldslp;
	578	struct SL_component *slp;
	579	slen = rr->len - 5;
	580	slp = &rr->u.SL.link;
	581	while (slen > 1) {
	582	rootflag = 0;
	583	switch (slp->flags & ~1) {
	584	case 0:
	585	if (slp->len > plimit - rpnt)
	586	return NULL;
	587	memcpy(rpnt, slp->text, slp->len);
1d372116	588	rpnt += slp->len;
1da177e4 LT	589	break;
	590	case 2:
	591	if (rpnt >= plimit)
	592	return NULL;
1d372116	593	*rpnt++ = '.';
1da177e4 LT	594	break;
	595	case 4:
	596	if (2 > plimit - rpnt)
	597	return NULL;
1d372116 AM	598	*rpnt++ = '.';
1d372116 AM	599	*rpnt++ = '.';
1da177e4 LT	600	break;
	601	case 8:
	602	if (rpnt >= plimit)
	603	return NULL;
	604	rootflag = 1;
1d372116	605	*rpnt++ = '/';
1da177e4 LT	606	break;
	607	default:
	608	printk("Symlink component flag not implemented (%d)\n",
1d372116	609	slp->flags);
1da177e4 LT	610	}
	611	slen -= slp->len + 2;
	612	oldslp = slp;
1d372116	613	slp = (struct SL_component )((char )slp + slp->len + 2);
1da177e4 LT	614
	615	if (slen < 2) {
	616	/*
	617	* If there is another SL record, and this component
	618	* record isn't continued, then add a slash.
	619	*/
	620	if ((!rootflag) && (rr->u.SL.flags & 1) &&
	621	!(oldslp->flags & 1)) {
	622	if (rpnt >= plimit)
	623	return NULL;
1d372116	624	*rpnt++ = '/';
1da177e4 LT	625	}
	626	break;
	627	}
	628
	629	/*
	630	* If this component record isn't continued, then append a '/'.
	631	*/
	632	if (!rootflag && !(oldslp->flags & 1)) {
	633	if (rpnt >= plimit)
	634	return NULL;
1d372116	635	*rpnt++ = '/';
1da177e4 LT	636	}
	637	}
	638	return rpnt;
	639	}
	640
1d372116	641	int parse_rock_ridge_inode(struct iso_directory_record de, struct inode inode)
1da177e4	642	{
1d372116	643	int result = parse_rock_ridge_inode_internal(de, inode, 0);
7373909d AM	644
	645	/*
	646	* if rockridge flag was reset and we didn't look for attributes
	647	* behind eventual XA attributes, have a look there
	648	*/
1d372116 AM	649	if ((ISOFS_SB(inode->i_sb)->s_rock_offset == -1)
	650	&& (ISOFS_SB(inode->i_sb)->s_rock == 2)) {
	651	result = parse_rock_ridge_inode_internal(de, inode, 14);
	652	}
	653	return result;
1da177e4 LT	654	}
1da177e4 LT	655
7373909d AM	656	/*
	657	* readpage() for symlinks: reads symlink contents into the page and either
	658	* makes it uptodate and returns 0 or returns error (-EIO)
	659	*/
1da177e4 LT	660	static int rock_ridge_symlink_readpage(struct file file, struct page page)
	661	{
	662	struct inode *inode = page->mapping->host;
1d372116	663	struct iso_inode_info *ei = ISOFS_I(inode);
1da177e4 LT	664	char *link = kmap(page);
	665	unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
	666	struct buffer_head *bh;
	667	char *rpnt = link;
	668	unsigned char *pnt;
76ab07eb	669	struct iso_directory_record *raw_de;
1da177e4 LT	670	unsigned long block, offset;
1da177e4 LT	671	int sig;
1da177e4	672	struct rock_ridge *rr;
ba40aaf0 AM	673	struct rock_state rs;
ba40aaf0 AM	674	int ret;
1da177e4 LT	675
	676	if (!ISOFS_SB(inode->i_sb)->s_rock)
	677	goto error;
	678
ba40aaf0	679	init_rock_state(&rs, inode);
1da177e4 LT	680	block = ei->i_iget5_block;
	681	lock_kernel();
	682	bh = sb_bread(inode->i_sb, block);
	683	if (!bh)
	684	goto out_noread;
	685
1d372116 AM	686	offset = ei->i_iget5_offset;
1d372116 AM	687	pnt = (unsigned char *)bh->b_data + offset;
1da177e4	688
76ab07eb	689	raw_de = (struct iso_directory_record *)pnt;
1da177e4 LT	690
	691	/*
	692	* If we go past the end of the buffer, there is some sort of error.
	693	*/
	694	if (offset + *pnt > bufsize)
	695	goto out_bad_span;
	696
7373909d AM	697	/*
	698	* Now test for possible Rock Ridge extensions which will override
	699	* some of these numbers in the inode structure.
	700	*/
1da177e4	701
ba40aaf0	702	setup_rock_ridge(raw_de, inode, &rs);
1da177e4	703
7fa393a1	704	repeat:
ba40aaf0 AM	705	while (rs.len > 2) { /* There may be one byte for padding somewhere */
ba40aaf0 AM	706	rr = (struct rock_ridge *)rs.chr;
1da177e4 LT	707	if (rr->len < 3)
1da177e4 LT	708	goto out; /* Something got screwed up here */
ba40aaf0	709	sig = isonum_721(rs.chr);
f2966632 AM	710	if (rock_check_overflow(&rs, sig))
f2966632 AM	711	goto out;
ba40aaf0 AM	712	rs.chr += rr->len;
	713	rs.len -= rr->len;
	714	if (rs.len < 0)
1da177e4 LT	715	goto out; /* corrupted isofs */
	716
	717	switch (sig) {
	718	case SIG('R', 'R'):
	719	if ((rr->u.RR.flags[0] & RR_SL) == 0)
	720	goto out;
	721	break;
	722	case SIG('S', 'P'):
12121714 AM	723	if (check_sp(rr, inode))
12121714 AM	724	goto out;
1da177e4 LT	725	break;
	726	case SIG('S', 'L'):
	727	rpnt = get_symlink_chunk(rpnt, rr,
	728	link + (PAGE_SIZE - 1));
	729	if (rpnt == NULL)
	730	goto out;
	731	break;
	732	case SIG('C', 'E'):
	733	/* This tells is if there is a continuation record */
ba40aaf0 AM	734	rs.cont_extent = isonum_733(rr->u.CE.extent);
	735	rs.cont_offset = isonum_733(rr->u.CE.offset);
	736	rs.cont_size = isonum_733(rr->u.CE.size);
1da177e4 LT	737	default:
	738	break;
	739	}
	740	}
ba40aaf0 AM	741	ret = rock_continue(&rs);
	742	if (ret == 0)
	743	goto repeat;
	744	if (ret < 0)
	745	goto fail;
1da177e4 LT	746
	747	if (rpnt == link)
	748	goto fail;
	749	brelse(bh);
	750	*rpnt = '\0';
	751	unlock_kernel();
	752	SetPageUptodate(page);
	753	kunmap(page);
	754	unlock_page(page);
	755	return 0;
	756
	757	/* error exit from macro */
7fa393a1	758	out:
ba40aaf0	759	kfree(rs.buffer);
1da177e4	760	goto fail;
7fa393a1	761	out_noread:
1da177e4 LT	762	printk("unable to read i-node block");
1da177e4 LT	763	goto fail;
7fa393a1	764	out_bad_span:
1da177e4	765	printk("symlink spans iso9660 blocks\n");
7fa393a1	766	fail:
1da177e4 LT	767	brelse(bh);
1da177e4 LT	768	unlock_kernel();
7fa393a1	769	error:
1da177e4 LT	770	SetPageError(page);
	771	kunmap(page);
	772	unlock_page(page);
	773	return -EIO;
	774	}
	775
f5e54d6e	776	const struct address_space_operations isofs_symlink_aops = {
1d372116	777	.readpage = rock_ridge_symlink_readpage
1da177e4	778	};