[mirror_ubuntu-zesty-kernel.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;
		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;
		if (rs.len < 0)
			goto eio;	/* corrupted isofs */

		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;
		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;
		if (rs.len < 0)
			goto eio;	/* corrupted isofs */

		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 (!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 < PAGE_CACHE_SHIFT
						|| 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;
7fa393a1 AM	212	if (rr->len < 3)
7fa393a1 AM	213	goto out; /* Something got screwed up here */
ba40aaf0	214	sig = isonum_721(rs.chr);
f2966632 AM	215	if (rock_check_overflow(&rs, sig))
f2966632 AM	216	goto eio;
ba40aaf0 AM	217	rs.chr += rr->len;
	218	rs.len -= rr->len;
	219	if (rs.len < 0)
f2966632	220	goto eio; /* corrupted isofs */
7fa393a1 AM	221
	222	switch (sig) {
	223	case SIG('R', 'R'):
	224	if ((rr->u.RR.flags[0] & RR_NM) == 0)
	225	goto out;
	226	break;
	227	case SIG('S', 'P'):
12121714 AM	228	if (check_sp(rr, inode))
12121714 AM	229	goto out;
7fa393a1 AM	230	break;
7fa393a1 AM	231	case SIG('C', 'E'):
ba40aaf0 AM	232	rs.cont_extent = isonum_733(rr->u.CE.extent);
	233	rs.cont_offset = isonum_733(rr->u.CE.offset);
	234	rs.cont_size = isonum_733(rr->u.CE.size);
7fa393a1 AM	235	break;
	236	case SIG('N', 'M'):
	237	if (truncate)
1d372116	238	break;
7fa393a1	239	if (rr->len < 5)
1d372116	240	break;
7fa393a1 AM	241	/*
	242	* If the flags are 2 or 4, this indicates '.' or '..'.
	243	* We don't want to do anything with this, because it
	244	* screws up the code that calls us. We don't really
	245	* care anyways, since we can just use the non-RR
	246	* name.
	247	*/
	248	if (rr->u.NM.flags & 6)
1d372116	249	break;
1d372116	250
7fa393a1 AM	251	if (rr->u.NM.flags & ~1) {
	252	printk("Unsupported NM flag settings (%d)\n",
	253	rr->u.NM.flags);
1d372116	254	break;
7fa393a1 AM	255	}
	256	if ((strlen(retname) + rr->len - 5) >= 254) {
	257	truncate = 1;
1d372116 AM	258	break;
1d372116 AM	259	}
7fa393a1 AM	260	strncat(retname, rr->u.NM.name, rr->len - 5);
	261	retnamlen += rr->len - 5;
	262	break;
	263	case SIG('R', 'E'):
ba40aaf0	264	kfree(rs.buffer);
7fa393a1 AM	265	return -1;
	266	default:
	267	break;
1d372116	268	}
1da177e4	269	}
ba40aaf0 AM	270	ret = rock_continue(&rs);
	271	if (ret == 0)
	272	goto repeat;
	273	if (ret == 1)
	274	return retnamlen; /* If 0, this file did not have a NM field */
7fa393a1	275	out:
ba40aaf0 AM	276	kfree(rs.buffer);
ba40aaf0 AM	277	return ret;
f2966632 AM	278	eio:
	279	ret = -EIO;
	280	goto out;
1da177e4 LT	281	}
	282
	283	static int
	284	parse_rock_ridge_inode_internal(struct iso_directory_record *de,
	285	struct inode *inode, int regard_xa)
	286	{
1d372116	287	int symlink_len = 0;
7fa393a1 AM	288	int cnt, sig;
	289	struct inode *reloc;
	290	struct rock_ridge *rr;
	291	int rootflag;
ba40aaf0 AM	292	struct rock_state rs;
ba40aaf0 AM	293	int ret = 0;
1d372116 AM	294
	295	if (!ISOFS_SB(inode->i_sb)->s_rock)
	296	return 0;
	297
ba40aaf0 AM	298	init_rock_state(&rs, inode);
ba40aaf0 AM	299	setup_rock_ridge(de, inode, &rs);
1d372116	300	if (regard_xa) {
ba40aaf0 AM	301	rs.chr += 14;
	302	rs.len -= 14;
	303	if (rs.len < 0)
	304	rs.len = 0;
1d372116 AM	305	}
1d372116 AM	306
7fa393a1	307	repeat:
ba40aaf0 AM	308	while (rs.len > 2) { /* There may be one byte for padding somewhere */
ba40aaf0 AM	309	rr = (struct rock_ridge *)rs.chr;
7fa393a1 AM	310	if (rr->len < 3)
7fa393a1 AM	311	goto out; /* Something got screwed up here */
ba40aaf0	312	sig = isonum_721(rs.chr);
f2966632 AM	313	if (rock_check_overflow(&rs, sig))
f2966632 AM	314	goto eio;
ba40aaf0 AM	315	rs.chr += rr->len;
	316	rs.len -= rr->len;
	317	if (rs.len < 0)
f2966632	318	goto eio; /* corrupted isofs */
7fa393a1 AM	319
7fa393a1 AM	320	switch (sig) {
1da177e4	321	#ifndef CONFIG_ZISOFS /* No flag for SF or ZF */
7fa393a1 AM	322	case SIG('R', 'R'):
	323	if ((rr->u.RR.flags[0] &
	324	(RR_PX \| RR_TF \| RR_SL \| RR_CL)) == 0)
	325	goto out;
	326	break;
1da177e4	327	#endif
7fa393a1	328	case SIG('S', 'P'):
12121714 AM	329	if (check_sp(rr, inode))
12121714 AM	330	goto out;
7fa393a1 AM	331	break;
7fa393a1 AM	332	case SIG('C', 'E'):
ba40aaf0 AM	333	rs.cont_extent = isonum_733(rr->u.CE.extent);
	334	rs.cont_offset = isonum_733(rr->u.CE.offset);
	335	rs.cont_size = isonum_733(rr->u.CE.size);
7fa393a1 AM	336	break;
	337	case SIG('E', 'R'):
	338	ISOFS_SB(inode->i_sb)->s_rock = 1;
	339	printk(KERN_DEBUG "ISO 9660 Extensions: ");
	340	{
	341	int p;
	342	for (p = 0; p < rr->u.ER.len_id; p++)
	343	printk("%c", rr->u.ER.data[p]);
	344	}
	345	printk("\n");
	346	break;
	347	case SIG('P', 'X'):
	348	inode->i_mode = isonum_733(rr->u.PX.mode);
	349	inode->i_nlink = isonum_733(rr->u.PX.n_links);
	350	inode->i_uid = isonum_733(rr->u.PX.uid);
	351	inode->i_gid = isonum_733(rr->u.PX.gid);
	352	break;
	353	case SIG('P', 'N'):
	354	{
	355	int high, low;
	356	high = isonum_733(rr->u.PN.dev_high);
	357	low = isonum_733(rr->u.PN.dev_low);
	358	/*
	359	* The Rock Ridge standard specifies that if
	360	* sizeof(dev_t) <= 4, then the high field is
	361	* unused, and the device number is completely
	362	* stored in the low field. Some writers may
	363	* ignore this subtlety,
	364	* and as a result we test to see if the entire
	365	* device number is
	366	* stored in the low field, and use that.
	367	*/
	368	if ((low & ~0xff) && high == 0) {
	369	inode->i_rdev =
	370	MKDEV(low >> 8, low & 0xff);
	371	} else {
	372	inode->i_rdev =
	373	MKDEV(high, low);
1d372116	374	}
7fa393a1 AM	375	}
	376	break;
	377	case SIG('T', 'F'):
	378	/*
	379	* Some RRIP writers incorrectly place ctime in the
	380	* TF_CREATE field. Try to handle this correctly for
	381	* either case.
	382	*/
	383	/* Rock ridge never appears on a High Sierra disk */
	384	cnt = 0;
	385	if (rr->u.TF.flags & TF_CREATE) {
	386	inode->i_ctime.tv_sec =
	387	iso_date(rr->u.TF.times[cnt++].time,
	388	0);
	389	inode->i_ctime.tv_nsec = 0;
	390	}
	391	if (rr->u.TF.flags & TF_MODIFY) {
	392	inode->i_mtime.tv_sec =
	393	iso_date(rr->u.TF.times[cnt++].time,
	394	0);
	395	inode->i_mtime.tv_nsec = 0;
	396	}
	397	if (rr->u.TF.flags & TF_ACCESS) {
	398	inode->i_atime.tv_sec =
	399	iso_date(rr->u.TF.times[cnt++].time,
	400	0);
	401	inode->i_atime.tv_nsec = 0;
	402	}
	403	if (rr->u.TF.flags & TF_ATTRIBUTES) {
	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	break;
	410	case SIG('S', 'L'):
	411	{
	412	int slen;
	413	struct SL_component *slp;
	414	struct SL_component *oldslp;
	415	slen = rr->len - 5;
	416	slp = &rr->u.SL.link;
	417	inode->i_size = symlink_len;
	418	while (slen > 1) {
	419	rootflag = 0;
	420	switch (slp->flags & ~1) {
	421	case 0:
	422	inode->i_size +=
	423	slp->len;
	424	break;
	425	case 2:
	426	inode->i_size += 1;
	427	break;
	428	case 4:
	429	inode->i_size += 2;
	430	break;
	431	case 8:
	432	rootflag = 1;
	433	inode->i_size += 1;
	434	break;
	435	default:
	436	printk("Symlink component flag "
	437	"not implemented\n");
1d372116	438	}
7fa393a1 AM	439	slen -= slp->len + 2;
	440	oldslp = slp;
	441	slp = (struct SL_component *)
	442	(((char *)slp) + slp->len + 2);
	443
	444	if (slen < 2) {
	445	if (((rr->u.SL.
	446	flags & 1) != 0)
	447	&&
	448	((oldslp->
	449	flags & 1) == 0))
1d372116	450	inode->i_size +=
7fa393a1 AM	451	1;
7fa393a1 AM	452	break;
1d372116	453	}
7fa393a1 AM	454
	455	/*
	456	* If this component record isn't
	457	* continued, then append a '/'.
	458	*/
	459	if (!rootflag
	460	&& (oldslp->flags & 1) == 0)
	461	inode->i_size += 1;
1d372116	462	}
7fa393a1 AM	463	}
	464	symlink_len = inode->i_size;
	465	break;
	466	case SIG('R', 'E'):
	467	printk(KERN_WARNING "Attempt to read inode for "
	468	"relocated directory\n");
	469	goto out;
	470	case SIG('C', 'L'):
	471	ISOFS_I(inode)->i_first_extent =
	472	isonum_733(rr->u.CL.location);
	473	reloc =
	474	isofs_iget(inode->i_sb,
	475	ISOFS_I(inode)->i_first_extent,
	476	0);
	477	if (!reloc)
1d372116	478	goto out;
7fa393a1 AM	479	inode->i_mode = reloc->i_mode;
	480	inode->i_nlink = reloc->i_nlink;
	481	inode->i_uid = reloc->i_uid;
	482	inode->i_gid = reloc->i_gid;
	483	inode->i_rdev = reloc->i_rdev;
	484	inode->i_size = reloc->i_size;
	485	inode->i_blocks = reloc->i_blocks;
	486	inode->i_atime = reloc->i_atime;
	487	inode->i_ctime = reloc->i_ctime;
	488	inode->i_mtime = reloc->i_mtime;
	489	iput(reloc);
	490	break;
1da177e4	491	#ifdef CONFIG_ZISOFS
7fa393a1 AM	492	case SIG('Z', 'F'): {
	493	int algo;
	494
	495	if (ISOFS_SB(inode->i_sb)->s_nocompress)
1d372116	496	break;
7fa393a1 AM	497	algo = isonum_721(rr->u.ZF.algorithm);
	498	if (algo == SIG('p', 'z')) {
	499	int block_shift =
	500	isonum_711(&rr->u.ZF.parms[1]);
	501	if (block_shift < PAGE_CACHE_SHIFT
	502	\|\| block_shift > 17) {
	503	printk(KERN_WARNING "isofs: "
	504	"Can't handle ZF block "
	505	"size of 2^%d\n",
	506	block_shift);
	507	} else {
	508	/*
	509	* Note: we don't change
	510	* i_blocks here
	511	*/
	512	ISOFS_I(inode)->i_file_format =
	513	isofs_file_compressed;
	514	/*
	515	* Parameters to compression
	516	* algorithm (header size,
	517	* block size)
	518	*/
	519	ISOFS_I(inode)->i_format_parm[0] =
	520	isonum_711(&rr->u.ZF.parms[0]);
	521	ISOFS_I(inode)->i_format_parm[1] =
	522	isonum_711(&rr->u.ZF.parms[1]);
	523	inode->i_size =
	524	isonum_733(rr->u.ZF.
	525	real_size);
	526	}
	527	} else {
	528	printk(KERN_WARNING
	529	"isofs: Unknown ZF compression "
	530	"algorithm: %c%c\n",
	531	rr->u.ZF.algorithm[0],
	532	rr->u.ZF.algorithm[1]);
1d372116	533	}
7fa393a1 AM	534	break;
	535	}
	536	#endif
	537	default:
	538	break;
1d372116 AM	539	}
1d372116 AM	540	}
ba40aaf0 AM	541	ret = rock_continue(&rs);
	542	if (ret == 0)
	543	goto repeat;
	544	if (ret == 1)
	545	ret = 0;
7fa393a1	546	out:
ba40aaf0 AM	547	kfree(rs.buffer);
ba40aaf0 AM	548	return ret;
f2966632 AM	549	eio:
	550	ret = -EIO;
	551	goto out;
1da177e4 LT	552	}
	553
	554	static char get_symlink_chunk(char rpnt, struct rock_ridge rr, char plimit)
	555	{
	556	int slen;
	557	int rootflag;
	558	struct SL_component *oldslp;
	559	struct SL_component *slp;
	560	slen = rr->len - 5;
	561	slp = &rr->u.SL.link;
	562	while (slen > 1) {
	563	rootflag = 0;
	564	switch (slp->flags & ~1) {
	565	case 0:
	566	if (slp->len > plimit - rpnt)
	567	return NULL;
	568	memcpy(rpnt, slp->text, slp->len);
1d372116	569	rpnt += slp->len;
1da177e4 LT	570	break;
	571	case 2:
	572	if (rpnt >= plimit)
	573	return NULL;
1d372116	574	*rpnt++ = '.';
1da177e4 LT	575	break;
	576	case 4:
	577	if (2 > plimit - rpnt)
	578	return NULL;
1d372116 AM	579	*rpnt++ = '.';
1d372116 AM	580	*rpnt++ = '.';
1da177e4 LT	581	break;
	582	case 8:
	583	if (rpnt >= plimit)
	584	return NULL;
	585	rootflag = 1;
1d372116	586	*rpnt++ = '/';
1da177e4 LT	587	break;
	588	default:
	589	printk("Symlink component flag not implemented (%d)\n",
1d372116	590	slp->flags);
1da177e4 LT	591	}
	592	slen -= slp->len + 2;
	593	oldslp = slp;
1d372116	594	slp = (struct SL_component )((char )slp + slp->len + 2);
1da177e4 LT	595
	596	if (slen < 2) {
	597	/*
	598	* If there is another SL record, and this component
	599	* record isn't continued, then add a slash.
	600	*/
	601	if ((!rootflag) && (rr->u.SL.flags & 1) &&
	602	!(oldslp->flags & 1)) {
	603	if (rpnt >= plimit)
	604	return NULL;
1d372116	605	*rpnt++ = '/';
1da177e4 LT	606	}
	607	break;
	608	}
	609
	610	/*
	611	* If this component record isn't continued, then append a '/'.
	612	*/
	613	if (!rootflag && !(oldslp->flags & 1)) {
	614	if (rpnt >= plimit)
	615	return NULL;
1d372116	616	*rpnt++ = '/';
1da177e4 LT	617	}
	618	}
	619	return rpnt;
	620	}
	621
1d372116	622	int parse_rock_ridge_inode(struct iso_directory_record de, struct inode inode)
1da177e4	623	{
1d372116	624	int result = parse_rock_ridge_inode_internal(de, inode, 0);
7373909d AM	625
	626	/*
	627	* if rockridge flag was reset and we didn't look for attributes
	628	* behind eventual XA attributes, have a look there
	629	*/
1d372116 AM	630	if ((ISOFS_SB(inode->i_sb)->s_rock_offset == -1)
	631	&& (ISOFS_SB(inode->i_sb)->s_rock == 2)) {
	632	result = parse_rock_ridge_inode_internal(de, inode, 14);
	633	}
	634	return result;
1da177e4 LT	635	}
1da177e4 LT	636
7373909d AM	637	/*
	638	* readpage() for symlinks: reads symlink contents into the page and either
	639	* makes it uptodate and returns 0 or returns error (-EIO)
	640	*/
1da177e4 LT	641	static int rock_ridge_symlink_readpage(struct file file, struct page page)
	642	{
	643	struct inode *inode = page->mapping->host;
1d372116	644	struct iso_inode_info *ei = ISOFS_I(inode);
1da177e4 LT	645	char *link = kmap(page);
	646	unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
	647	struct buffer_head *bh;
	648	char *rpnt = link;
	649	unsigned char *pnt;
76ab07eb	650	struct iso_directory_record *raw_de;
1da177e4 LT	651	unsigned long block, offset;
1da177e4 LT	652	int sig;
1da177e4	653	struct rock_ridge *rr;
ba40aaf0 AM	654	struct rock_state rs;
ba40aaf0 AM	655	int ret;
1da177e4 LT	656
	657	if (!ISOFS_SB(inode->i_sb)->s_rock)
	658	goto error;
	659
ba40aaf0	660	init_rock_state(&rs, inode);
1da177e4 LT	661	block = ei->i_iget5_block;
	662	lock_kernel();
	663	bh = sb_bread(inode->i_sb, block);
	664	if (!bh)
	665	goto out_noread;
	666
1d372116 AM	667	offset = ei->i_iget5_offset;
1d372116 AM	668	pnt = (unsigned char *)bh->b_data + offset;
1da177e4	669
76ab07eb	670	raw_de = (struct iso_directory_record *)pnt;
1da177e4 LT	671
	672	/*
	673	* If we go past the end of the buffer, there is some sort of error.
	674	*/
	675	if (offset + *pnt > bufsize)
	676	goto out_bad_span;
	677
7373909d AM	678	/*
	679	* Now test for possible Rock Ridge extensions which will override
	680	* some of these numbers in the inode structure.
	681	*/
1da177e4	682
ba40aaf0	683	setup_rock_ridge(raw_de, inode, &rs);
1da177e4	684
7fa393a1	685	repeat:
ba40aaf0 AM	686	while (rs.len > 2) { /* There may be one byte for padding somewhere */
ba40aaf0 AM	687	rr = (struct rock_ridge *)rs.chr;
1da177e4 LT	688	if (rr->len < 3)
1da177e4 LT	689	goto out; /* Something got screwed up here */
ba40aaf0	690	sig = isonum_721(rs.chr);
f2966632 AM	691	if (rock_check_overflow(&rs, sig))
f2966632 AM	692	goto out;
ba40aaf0 AM	693	rs.chr += rr->len;
	694	rs.len -= rr->len;
	695	if (rs.len < 0)
1da177e4 LT	696	goto out; /* corrupted isofs */
	697
	698	switch (sig) {
	699	case SIG('R', 'R'):
	700	if ((rr->u.RR.flags[0] & RR_SL) == 0)
	701	goto out;
	702	break;
	703	case SIG('S', 'P'):
12121714 AM	704	if (check_sp(rr, inode))
12121714 AM	705	goto out;
1da177e4 LT	706	break;
	707	case SIG('S', 'L'):
	708	rpnt = get_symlink_chunk(rpnt, rr,
	709	link + (PAGE_SIZE - 1));
	710	if (rpnt == NULL)
	711	goto out;
	712	break;
	713	case SIG('C', 'E'):
	714	/* This tells is if there is a continuation record */
ba40aaf0 AM	715	rs.cont_extent = isonum_733(rr->u.CE.extent);
	716	rs.cont_offset = isonum_733(rr->u.CE.offset);
	717	rs.cont_size = isonum_733(rr->u.CE.size);
1da177e4 LT	718	default:
	719	break;
	720	}
	721	}
ba40aaf0 AM	722	ret = rock_continue(&rs);
	723	if (ret == 0)
	724	goto repeat;
	725	if (ret < 0)
	726	goto fail;
1da177e4 LT	727
	728	if (rpnt == link)
	729	goto fail;
	730	brelse(bh);
	731	*rpnt = '\0';
	732	unlock_kernel();
	733	SetPageUptodate(page);
	734	kunmap(page);
	735	unlock_page(page);
	736	return 0;
	737
	738	/* error exit from macro */
7fa393a1	739	out:
ba40aaf0	740	kfree(rs.buffer);
1da177e4	741	goto fail;
7fa393a1	742	out_noread:
1da177e4 LT	743	printk("unable to read i-node block");
1da177e4 LT	744	goto fail;
7fa393a1	745	out_bad_span:
1da177e4	746	printk("symlink spans iso9660 blocks\n");
7fa393a1	747	fail:
1da177e4 LT	748	brelse(bh);
1da177e4 LT	749	unlock_kernel();
7fa393a1	750	error:
1da177e4 LT	751	SetPageError(page);
	752	kunmap(page);
	753	unlock_page(page);
	754	return -EIO;
	755	}
	756
f5e54d6e	757	const struct address_space_operations isofs_symlink_aops = {
1d372116	758	.readpage = rock_ridge_symlink_readpage
1da177e4	759	};