Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 809 insertions, 0 deletions

diff --git a/fs/isofs/rock.c b/fs/isofs/rock.c
new file mode 100644
index 000000000..48f58c6c9
--- /dev/null
+++ b/fs/isofs/rock.c
@@ -0,0 +1,809 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/isofs/rock.c
+ *
+ *  (C) 1992, 1993  Eric Youngdale
+ *
+ *  Rock Ridge Extensions to iso9660
+ */
+
+#include <linux/slab.h>
+#include <linux/pagemap.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;
+	int cont_loops;
+	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;
+}
+
+/* Maximum number of Rock Ridge continuation entries */
+#define RR_MAX_CE_ENTRIES 32
+
+/*
+ * 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;
+		if (++rs->cont_loops >= RR_MAX_CE_ENTRIES)
+			goto out;
+		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;
+	char *p;
+	int len;
+
+	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;
+			}
+			len = rr->len - 5;
+			if (retnamlen + len >= 254) {
+				truncate = 1;
+				break;
+			}
+			p = memchr(rr->u.NM.name, '\0', len);
+			if (unlikely(p))
+				len = p - rr->u.NM.name;
+			memcpy(retname + retnamlen, rr->u.NM.name, len);
+			retnamlen += len;
+			retname[retnamlen] = '\0';
+			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;
+}
+
+#define RR_REGARD_XA 1
+#define RR_RELOC_DE 2
+
+static int
+parse_rock_ridge_inode_internal(struct iso_directory_record *de,
+				struct inode *inode, int flags)
+{
+	int symlink_len = 0;
+	int cnt, sig;
+	unsigned int reloc_block;
+	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 (flags & RR_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'):
+			/* Invalid length of ER tag id? */
+			if (rr->u.ER.len_id + offsetof(struct rock_ridge, u.ER.data) > rr->len)
+				goto out;
+			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(KERN_CONT "%c", rr->u.ER.data[p]);
+			}
+			printk(KERN_CONT "\n");
+			break;
+		case SIG('P', 'X'):
+			inode->i_mode = isonum_733(rr->u.PX.mode);
+			set_nlink(inode, isonum_733(rr->u.PX.n_links));
+			i_uid_write(inode, isonum_733(rr->u.PX.uid));
+			i_gid_write(inode, 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'):
+			if (flags & RR_RELOC_DE) {
+				printk(KERN_ERR
+				       "ISOFS: Recursive directory relocation "
+				       "is not supported\n");
+				goto eio;
+			}
+			reloc_block = isonum_733(rr->u.CL.location);
+			if (reloc_block == ISOFS_I(inode)->i_iget5_block &&
+			    ISOFS_I(inode)->i_iget5_offset == 0) {
+				printk(KERN_ERR
+				       "ISOFS: Directory relocation points to "
+				       "itself\n");
+				goto eio;
+			}
+			ISOFS_I(inode)->i_first_extent = reloc_block;
+			reloc = isofs_iget_reloc(inode->i_sb, reloc_block, 0);
+			if (IS_ERR(reloc)) {
+				ret = PTR_ERR(reloc);
+				goto out;
+			}
+			inode->i_mode = reloc->i_mode;
+			set_nlink(inode, 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 relocated)
+{
+	int flags = relocated ? RR_RELOC_DE : 0;
+	int result = parse_rock_ridge_inode_internal(de, inode, flags);
+
+	/*
+	 * 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,
+							 flags | RR_REGARD_XA);
+	}
+	return result;
+}
+
+/*
+ * read_folio() for symlinks: reads symlink contents into the folio and either
+ * makes it uptodate and returns 0 or returns error (-EIO)
+ */
+static int rock_ridge_symlink_read_folio(struct file *file, struct folio *folio)
+{
+	struct page *page = &folio->page;
+	struct inode *inode = page->mapping->host;
+	struct iso_inode_info *ei = ISOFS_I(inode);
+	struct isofs_sb_info *sbi = ISOFS_SB(inode->i_sb);
+	char *link = page_address(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 (!sbi->s_rock)
+		goto error;
+
+	init_rock_state(&rs, inode);
+	block = ei->i_iget5_block;
+	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);
+			break;
+		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';
+	SetPageUptodate(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);
+error:
+	SetPageError(page);
+	unlock_page(page);
+	return -EIO;
+}
+
+const struct address_space_operations isofs_symlink_aops = {
+	.read_folio = rock_ridge_symlink_read_folio
+};