Adding upstream version 6.1.76.upstream/6.1.76upstream

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

13 files changed, 3990 insertions, 0 deletions

diff --git a/fs/isofs/Kconfig b/fs/isofs/Kconfig
new file mode 100644
index 000000000..08ffd37b9
--- /dev/null
+++ b/fs/isofs/Kconfig
@@ -0,0 +1,40 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config ISO9660_FS
+	tristate "ISO 9660 CDROM file system support"
+	help
+	  This is the standard file system used on CD-ROMs.  It was previously
+	  known as "High Sierra File System" and is called "hsfs" on other
+	  Unix systems.  The so-called Rock-Ridge extensions which allow for
+	  long Unix filenames and symbolic links are also supported by this
+	  driver.  If you have a CD-ROM drive and want to do more with it than
+	  just listen to audio CDs and watch its LEDs, say Y (and read
+	  <file:Documentation/filesystems/isofs.rst> and the CD-ROM-HOWTO,
+	  available from <http://www.tldp.org/docs.html#howto>), thereby
+	  enlarging your kernel by about 27 KB; otherwise say N.
+
+	  To compile this file system support as a module, choose M here: the
+	  module will be called isofs.
+
+config JOLIET
+	bool "Microsoft Joliet CDROM extensions"
+	depends on ISO9660_FS
+	select NLS
+	help
+	  Joliet is a Microsoft extension for the ISO 9660 CD-ROM file system
+	  which allows for long filenames in unicode format (unicode is the
+	  new 16 bit character code, successor to ASCII, which encodes the
+	  characters of almost all languages of the world; see
+	  <http://www.unicode.org/> for more information).  Say Y here if you
+	  want to be able to read Joliet CD-ROMs under Linux.
+
+config ZISOFS
+	bool "Transparent decompression extension"
+	depends on ISO9660_FS
+	select ZLIB_INFLATE
+	help
+	  This is a Linux-specific extension to RockRidge which lets you store
+	  data in compressed form on a CD-ROM and have it transparently
+	  decompressed when the CD-ROM is accessed.  See
+	  <http://www.kernel.org/pub/linux/utils/fs/zisofs/> for the tools
+	  necessary to create such a filesystem.  Say Y here if you want to be
+	  able to read such compressed CD-ROMs.
diff --git a/fs/isofs/Makefile b/fs/isofs/Makefile
new file mode 100644
index 000000000..6498fd2b0
--- /dev/null
+++ b/fs/isofs/Makefile
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the Linux isofs filesystem routines.
+#
+
+obj-$(CONFIG_ISO9660_FS) += isofs.o
+
+isofs-objs-y 			:= namei.o inode.o dir.o util.o rock.o export.o
+isofs-objs-$(CONFIG_JOLIET)	+= joliet.o
+isofs-objs-$(CONFIG_ZISOFS)	+= compress.o
+isofs-objs			:= $(isofs-objs-y)
diff --git a/fs/isofs/compress.c b/fs/isofs/compress.c
new file mode 100644
index 000000000..c4da3f634
--- /dev/null
+++ b/fs/isofs/compress.c
@@ -0,0 +1,389 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *   
+ *   Copyright 2001 H. Peter Anvin - All Rights Reserved
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * linux/fs/isofs/compress.c
+ *
+ * Transparent decompression of files on an iso9660 filesystem
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/bio.h>
+
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/zlib.h>
+
+#include "isofs.h"
+#include "zisofs.h"
+
+/* This should probably be global. */
+static char zisofs_sink_page[PAGE_SIZE];
+
+/*
+ * This contains the zlib memory allocation and the mutex for the
+ * allocation; this avoids failures at block-decompression time.
+ */
+static void *zisofs_zlib_workspace;
+static DEFINE_MUTEX(zisofs_zlib_lock);
+
+/*
+ * Read data of @inode from @block_start to @block_end and uncompress
+ * to one zisofs block. Store the data in the @pages array with @pcount
+ * entries. Start storing at offset @poffset of the first page.
+ */
+static loff_t zisofs_uncompress_block(struct inode *inode, loff_t block_start,
+				      loff_t block_end, int pcount,
+				      struct page **pages, unsigned poffset,
+				      int *errp)
+{
+	unsigned int zisofs_block_shift = ISOFS_I(inode)->i_format_parm[1];
+	unsigned int bufsize = ISOFS_BUFFER_SIZE(inode);
+	unsigned int bufshift = ISOFS_BUFFER_BITS(inode);
+	unsigned int bufmask = bufsize - 1;
+	int i, block_size = block_end - block_start;
+	z_stream stream = { .total_out = 0,
+			    .avail_in = 0,
+			    .avail_out = 0, };
+	int zerr;
+	int needblocks = (block_size + (block_start & bufmask) + bufmask)
+				>> bufshift;
+	int haveblocks;
+	blkcnt_t blocknum;
+	struct buffer_head **bhs;
+	int curbh, curpage;
+
+	if (block_size > deflateBound(1UL << zisofs_block_shift)) {
+		*errp = -EIO;
+		return 0;
+	}
+	/* Empty block? */
+	if (block_size == 0) {
+		for ( i = 0 ; i < pcount ; i++ ) {
+			if (!pages[i])
+				continue;
+			memzero_page(pages[i], 0, PAGE_SIZE);
+			SetPageUptodate(pages[i]);
+		}
+		return ((loff_t)pcount) << PAGE_SHIFT;
+	}
+
+	/* Because zlib is not thread-safe, do all the I/O at the top. */
+	blocknum = block_start >> bufshift;
+	bhs = kcalloc(needblocks + 1, sizeof(*bhs), GFP_KERNEL);
+	if (!bhs) {
+		*errp = -ENOMEM;
+		return 0;
+	}
+	haveblocks = isofs_get_blocks(inode, blocknum, bhs, needblocks);
+	bh_read_batch(haveblocks, bhs);
+
+	curbh = 0;
+	curpage = 0;
+	/*
+	 * First block is special since it may be fractional.  We also wait for
+	 * it before grabbing the zlib mutex; odds are that the subsequent
+	 * blocks are going to come in in short order so we don't hold the zlib
+	 * mutex longer than necessary.
+	 */
+
+	if (!bhs[0])
+		goto b_eio;
+
+	wait_on_buffer(bhs[0]);
+	if (!buffer_uptodate(bhs[0])) {
+		*errp = -EIO;
+		goto b_eio;
+	}
+
+	stream.workspace = zisofs_zlib_workspace;
+	mutex_lock(&zisofs_zlib_lock);
+		
+	zerr = zlib_inflateInit(&stream);
+	if (zerr != Z_OK) {
+		if (zerr == Z_MEM_ERROR)
+			*errp = -ENOMEM;
+		else
+			*errp = -EIO;
+		printk(KERN_DEBUG "zisofs: zisofs_inflateInit returned %d\n",
+			       zerr);
+		goto z_eio;
+	}
+
+	while (curpage < pcount && curbh < haveblocks &&
+	       zerr != Z_STREAM_END) {
+		if (!stream.avail_out) {
+			if (pages[curpage]) {
+				stream.next_out = kmap_local_page(pages[curpage])
+						+ poffset;
+				stream.avail_out = PAGE_SIZE - poffset;
+				poffset = 0;
+			} else {
+				stream.next_out = (void *)&zisofs_sink_page;
+				stream.avail_out = PAGE_SIZE;
+			}
+		}
+		if (!stream.avail_in) {
+			wait_on_buffer(bhs[curbh]);
+			if (!buffer_uptodate(bhs[curbh])) {
+				*errp = -EIO;
+				break;
+			}
+			stream.next_in  = bhs[curbh]->b_data +
+						(block_start & bufmask);
+			stream.avail_in = min_t(unsigned, bufsize -
+						(block_start & bufmask),
+						block_size);
+			block_size -= stream.avail_in;
+			block_start = 0;
+		}
+
+		while (stream.avail_out && stream.avail_in) {
+			zerr = zlib_inflate(&stream, Z_SYNC_FLUSH);
+			if (zerr == Z_BUF_ERROR && stream.avail_in == 0)
+				break;
+			if (zerr == Z_STREAM_END)
+				break;
+			if (zerr != Z_OK) {
+				/* EOF, error, or trying to read beyond end of input */
+				if (zerr == Z_MEM_ERROR)
+					*errp = -ENOMEM;
+				else {
+					printk(KERN_DEBUG
+					       "zisofs: zisofs_inflate returned"
+					       " %d, inode = %lu,"
+					       " page idx = %d, bh idx = %d,"
+					       " avail_in = %ld,"
+					       " avail_out = %ld\n",
+					       zerr, inode->i_ino, curpage,
+					       curbh, stream.avail_in,
+					       stream.avail_out);
+					*errp = -EIO;
+				}
+				goto inflate_out;
+			}
+		}
+
+		if (!stream.avail_out) {
+			/* This page completed */
+			if (pages[curpage]) {
+				flush_dcache_page(pages[curpage]);
+				SetPageUptodate(pages[curpage]);
+			}
+			if (stream.next_out != (unsigned char *)zisofs_sink_page) {
+				kunmap_local(stream.next_out);
+				stream.next_out = NULL;
+			}
+			curpage++;
+		}
+		if (!stream.avail_in)
+			curbh++;
+	}
+inflate_out:
+	zlib_inflateEnd(&stream);
+	if (stream.next_out && stream.next_out != (unsigned char *)zisofs_sink_page)
+		kunmap_local(stream.next_out);
+
+z_eio:
+	mutex_unlock(&zisofs_zlib_lock);
+
+b_eio:
+	for (i = 0; i < haveblocks; i++)
+		brelse(bhs[i]);
+	kfree(bhs);
+	return stream.total_out;
+}
+
+/*
+ * Uncompress data so that pages[full_page] is fully uptodate and possibly
+ * fills in other pages if we have data for them.
+ */
+static int zisofs_fill_pages(struct inode *inode, int full_page, int pcount,
+			     struct page **pages)
+{
+	loff_t start_off, end_off;
+	loff_t block_start, block_end;
+	unsigned int header_size = ISOFS_I(inode)->i_format_parm[0];
+	unsigned int zisofs_block_shift = ISOFS_I(inode)->i_format_parm[1];
+	unsigned int blockptr;
+	loff_t poffset = 0;
+	blkcnt_t cstart_block, cend_block;
+	struct buffer_head *bh;
+	unsigned int blkbits = ISOFS_BUFFER_BITS(inode);
+	unsigned int blksize = 1 << blkbits;
+	int err;
+	loff_t ret;
+
+	BUG_ON(!pages[full_page]);
+
+	/*
+	 * We want to read at least 'full_page' page. Because we have to
+	 * uncompress the whole compression block anyway, fill the surrounding
+	 * pages with the data we have anyway...
+	 */
+	start_off = page_offset(pages[full_page]);
+	end_off = min_t(loff_t, start_off + PAGE_SIZE, inode->i_size);
+
+	cstart_block = start_off >> zisofs_block_shift;
+	cend_block = (end_off + (1 << zisofs_block_shift) - 1)
+			>> zisofs_block_shift;
+
+	WARN_ON(start_off - (full_page << PAGE_SHIFT) !=
+		((cstart_block << zisofs_block_shift) & PAGE_MASK));
+
+	/* Find the pointer to this specific chunk */
+	/* Note: we're not using isonum_731() here because the data is known aligned */
+	/* Note: header_size is in 32-bit words (4 bytes) */
+	blockptr = (header_size + cstart_block) << 2;
+	bh = isofs_bread(inode, blockptr >> blkbits);
+	if (!bh)
+		return -EIO;
+	block_start = le32_to_cpu(*(__le32 *)
+				(bh->b_data + (blockptr & (blksize - 1))));
+
+	while (cstart_block < cend_block && pcount > 0) {
+		/* Load end of the compressed block in the file */
+		blockptr += 4;
+		/* Traversed to next block? */
+		if (!(blockptr & (blksize - 1))) {
+			brelse(bh);
+
+			bh = isofs_bread(inode, blockptr >> blkbits);
+			if (!bh)
+				return -EIO;
+		}
+		block_end = le32_to_cpu(*(__le32 *)
+				(bh->b_data + (blockptr & (blksize - 1))));
+		if (block_start > block_end) {
+			brelse(bh);
+			return -EIO;
+		}
+		err = 0;
+		ret = zisofs_uncompress_block(inode, block_start, block_end,
+					      pcount, pages, poffset, &err);
+		poffset += ret;
+		pages += poffset >> PAGE_SHIFT;
+		pcount -= poffset >> PAGE_SHIFT;
+		full_page -= poffset >> PAGE_SHIFT;
+		poffset &= ~PAGE_MASK;
+
+		if (err) {
+			brelse(bh);
+			/*
+			 * Did we finish reading the page we really wanted
+			 * to read?
+			 */
+			if (full_page < 0)
+				return 0;
+			return err;
+		}
+
+		block_start = block_end;
+		cstart_block++;
+	}
+
+	if (poffset && *pages) {
+		memzero_page(*pages, poffset, PAGE_SIZE - poffset);
+		SetPageUptodate(*pages);
+	}
+	return 0;
+}
+
+/*
+ * When decompressing, we typically obtain more than one page
+ * per reference.  We inject the additional pages into the page
+ * cache as a form of readahead.
+ */
+static int zisofs_read_folio(struct file *file, struct folio *folio)
+{
+	struct page *page = &folio->page;
+	struct inode *inode = file_inode(file);
+	struct address_space *mapping = inode->i_mapping;
+	int err;
+	int i, pcount, full_page;
+	unsigned int zisofs_block_shift = ISOFS_I(inode)->i_format_parm[1];
+	unsigned int zisofs_pages_per_cblock =
+		PAGE_SHIFT <= zisofs_block_shift ?
+		(1 << (zisofs_block_shift - PAGE_SHIFT)) : 0;
+	struct page **pages;
+	pgoff_t index = page->index, end_index;
+
+	end_index = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT;
+	/*
+	 * If this page is wholly outside i_size we just return zero;
+	 * do_generic_file_read() will handle this for us
+	 */
+	if (index >= end_index) {
+		SetPageUptodate(page);
+		unlock_page(page);
+		return 0;
+	}
+
+	if (PAGE_SHIFT <= zisofs_block_shift) {
+		/* We have already been given one page, this is the one
+		   we must do. */
+		full_page = index & (zisofs_pages_per_cblock - 1);
+		pcount = min_t(int, zisofs_pages_per_cblock,
+			end_index - (index & ~(zisofs_pages_per_cblock - 1)));
+		index -= full_page;
+	} else {
+		full_page = 0;
+		pcount = 1;
+	}
+	pages = kcalloc(max_t(unsigned int, zisofs_pages_per_cblock, 1),
+					sizeof(*pages), GFP_KERNEL);
+	if (!pages) {
+		unlock_page(page);
+		return -ENOMEM;
+	}
+	pages[full_page] = page;
+
+	for (i = 0; i < pcount; i++, index++) {
+		if (i != full_page)
+			pages[i] = grab_cache_page_nowait(mapping, index);
+		if (pages[i])
+			ClearPageError(pages[i]);
+	}
+
+	err = zisofs_fill_pages(inode, full_page, pcount, pages);
+
+	/* Release any residual pages, do not SetPageUptodate */
+	for (i = 0; i < pcount; i++) {
+		if (pages[i]) {
+			flush_dcache_page(pages[i]);
+			if (i == full_page && err)
+				SetPageError(pages[i]);
+			unlock_page(pages[i]);
+			if (i != full_page)
+				put_page(pages[i]);
+		}
+	}			
+
+	/* At this point, err contains 0 or -EIO depending on the "critical" page */
+	kfree(pages);
+	return err;
+}
+
+const struct address_space_operations zisofs_aops = {
+	.read_folio = zisofs_read_folio,
+	/* No bmap operation supported */
+};
+
+int __init zisofs_init(void)
+{
+	zisofs_zlib_workspace = vmalloc(zlib_inflate_workspacesize());
+	if ( !zisofs_zlib_workspace )
+		return -ENOMEM;
+
+	return 0;
+}
+
+void zisofs_cleanup(void)
+{
+	vfree(zisofs_zlib_workspace);
+}
diff --git a/fs/isofs/dir.c b/fs/isofs/dir.c
new file mode 100644
index 000000000..eb2f8273e
--- /dev/null
+++ b/fs/isofs/dir.c
@@ -0,0 +1,283 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/isofs/dir.c
+ *
+ *  (C) 1992, 1993, 1994  Eric Youngdale Modified for ISO 9660 filesystem.
+ *
+ *  (C) 1991  Linus Torvalds - minix filesystem
+ *
+ *  Steve Beynon		       : Missing last directory entries fixed
+ *  (stephen@askone.demon.co.uk)      : 21st June 1996
+ *
+ *  isofs directory handling functions
+ */
+#include <linux/gfp.h>
+#include "isofs.h"
+
+int isofs_name_translate(struct iso_directory_record *de, char *new, struct inode *inode)
+{
+	char * old = de->name;
+	int len = de->name_len[0];
+	int i;
+
+	for (i = 0; i < len; i++) {
+		unsigned char c = old[i];
+		if (!c)
+			break;
+
+		if (c >= 'A' && c <= 'Z')
+			c |= 0x20;	/* lower case */
+
+		/* Drop trailing '.;1' (ISO 9660:1988 7.5.1 requires period) */
+		if (c == '.' && i == len - 3 && old[i + 1] == ';' && old[i + 2] == '1')
+			break;
+
+		/* Drop trailing ';1' */
+		if (c == ';' && i == len - 2 && old[i + 1] == '1')
+			break;
+
+		/* Convert remaining ';' to '.' */
+		/* Also '/' to '.' (broken Acorn-generated ISO9660 images) */
+		if (c == ';' || c == '/')
+			c = '.';
+
+		new[i] = c;
+	}
+	return i;
+}
+
+/* Acorn extensions written by Matthew Wilcox <willy@infradead.org> 1998 */
+int get_acorn_filename(struct iso_directory_record *de,
+			    char *retname, struct inode *inode)
+{
+	int std;
+	unsigned char *chr;
+	int retnamlen = isofs_name_translate(de, retname, inode);
+
+	if (retnamlen == 0)
+		return 0;
+	std = sizeof(struct iso_directory_record) + de->name_len[0];
+	if (std & 1)
+		std++;
+	if (de->length[0] - std != 32)
+		return retnamlen;
+	chr = ((unsigned char *) de) + std;
+	if (strncmp(chr, "ARCHIMEDES", 10))
+		return retnamlen;
+	if ((*retname == '_') && ((chr[19] & 1) == 1))
+		*retname = '!';
+	if (((de->flags[0] & 2) == 0) && (chr[13] == 0xff)
+		&& ((chr[12] & 0xf0) == 0xf0)) {
+		retname[retnamlen] = ',';
+		sprintf(retname+retnamlen+1, "%3.3x",
+			((chr[12] & 0xf) << 8) | chr[11]);
+		retnamlen += 4;
+	}
+	return retnamlen;
+}
+
+/*
+ * This should _really_ be cleaned up some day..
+ */
+static int do_isofs_readdir(struct inode *inode, struct file *file,
+		struct dir_context *ctx,
+		char *tmpname, struct iso_directory_record *tmpde)
+{
+	unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
+	unsigned char bufbits = ISOFS_BUFFER_BITS(inode);
+	unsigned long block, offset, block_saved, offset_saved;
+	unsigned long inode_number = 0;	/* Quiet GCC */
+	struct buffer_head *bh = NULL;
+	int len;
+	int map;
+	int first_de = 1;
+	char *p = NULL;		/* Quiet GCC */
+	struct iso_directory_record *de;
+	struct isofs_sb_info *sbi = ISOFS_SB(inode->i_sb);
+
+	offset = ctx->pos & (bufsize - 1);
+	block = ctx->pos >> bufbits;
+
+	while (ctx->pos < inode->i_size) {
+		int de_len;
+
+		if (!bh) {
+			bh = isofs_bread(inode, block);
+			if (!bh)
+				return 0;
+		}
+
+		de = (struct iso_directory_record *) (bh->b_data + offset);
+
+		de_len = *(unsigned char *)de;
+
+		/*
+		 * If the length byte is zero, we should move on to the next
+		 * CDROM sector.  If we are at the end of the directory, we
+		 * kick out of the while loop.
+		 */
+
+		if (de_len == 0) {
+			brelse(bh);
+			bh = NULL;
+			ctx->pos = (ctx->pos + ISOFS_BLOCK_SIZE) & ~(ISOFS_BLOCK_SIZE - 1);
+			block = ctx->pos >> bufbits;
+			offset = 0;
+			continue;
+		}
+
+		block_saved = block;
+		offset_saved = offset;
+		offset += de_len;
+
+		/* Make sure we have a full directory entry */
+		if (offset >= bufsize) {
+			int slop = bufsize - offset + de_len;
+			memcpy(tmpde, de, slop);
+			offset &= bufsize - 1;
+			block++;
+			brelse(bh);
+			bh = NULL;
+			if (offset) {
+				bh = isofs_bread(inode, block);
+				if (!bh)
+					return 0;
+				memcpy((void *) tmpde + slop, bh->b_data, offset);
+			}
+			de = tmpde;
+		}
+		/* Basic sanity check, whether name doesn't exceed dir entry */
+		if (de_len < de->name_len[0] +
+					sizeof(struct iso_directory_record)) {
+			printk(KERN_NOTICE "iso9660: Corrupted directory entry"
+			       " in block %lu of inode %lu\n", block,
+			       inode->i_ino);
+			brelse(bh);
+			return -EIO;
+		}
+
+		if (first_de) {
+			isofs_normalize_block_and_offset(de,
+							&block_saved,
+							&offset_saved);
+			inode_number = isofs_get_ino(block_saved,
+							offset_saved, bufbits);
+		}
+
+		if (de->flags[-sbi->s_high_sierra] & 0x80) {
+			first_de = 0;
+			ctx->pos += de_len;
+			continue;
+		}
+		first_de = 1;
+
+		/* Handle the case of the '.' directory */
+		if (de->name_len[0] == 1 && de->name[0] == 0) {
+			if (!dir_emit_dot(file, ctx))
+				break;
+			ctx->pos += de_len;
+			continue;
+		}
+
+		len = 0;
+
+		/* Handle the case of the '..' directory */
+		if (de->name_len[0] == 1 && de->name[0] == 1) {
+			if (!dir_emit_dotdot(file, ctx))
+				break;
+			ctx->pos += de_len;
+			continue;
+		}
+
+		/* Handle everything else.  Do name translation if there
+		   is no Rock Ridge NM field. */
+
+		/*
+		 * Do not report hidden files if so instructed, or associated
+		 * files unless instructed to do so
+		 */
+		if ((sbi->s_hide && (de->flags[-sbi->s_high_sierra] & 1)) ||
+		    (!sbi->s_showassoc &&
+				(de->flags[-sbi->s_high_sierra] & 4))) {
+			ctx->pos += de_len;
+			continue;
+		}
+
+		map = 1;
+		if (sbi->s_rock) {
+			len = get_rock_ridge_filename(de, tmpname, inode);
+			if (len != 0) {		/* may be -1 */
+				p = tmpname;
+				map = 0;
+			}
+		}
+		if (map) {
+#ifdef CONFIG_JOLIET
+			if (sbi->s_joliet_level) {
+				len = get_joliet_filename(de, tmpname, inode);
+				p = tmpname;
+			} else
+#endif
+			if (sbi->s_mapping == 'a') {
+				len = get_acorn_filename(de, tmpname, inode);
+				p = tmpname;
+			} else
+			if (sbi->s_mapping == 'n') {
+				len = isofs_name_translate(de, tmpname, inode);
+				p = tmpname;
+			} else {
+				p = de->name;
+				len = de->name_len[0];
+			}
+		}
+		if (len > 0) {
+			if (!dir_emit(ctx, p, len, inode_number, DT_UNKNOWN))
+				break;
+		}
+		ctx->pos += de_len;
+	}
+	if (bh)
+		brelse(bh);
+	return 0;
+}
+
+/*
+ * Handle allocation of temporary space for name translation and
+ * handling split directory entries.. The real work is done by
+ * "do_isofs_readdir()".
+ */
+static int isofs_readdir(struct file *file, struct dir_context *ctx)
+{
+	int result;
+	char *tmpname;
+	struct iso_directory_record *tmpde;
+	struct inode *inode = file_inode(file);
+
+	tmpname = (char *)__get_free_page(GFP_KERNEL);
+	if (tmpname == NULL)
+		return -ENOMEM;
+
+	tmpde = (struct iso_directory_record *) (tmpname+1024);
+
+	result = do_isofs_readdir(inode, file, ctx, tmpname, tmpde);
+
+	free_page((unsigned long) tmpname);
+	return result;
+}
+
+const struct file_operations isofs_dir_operations =
+{
+	.llseek = generic_file_llseek,
+	.read = generic_read_dir,
+	.iterate_shared = isofs_readdir,
+};
+
+/*
+ * directories can handle most operations...
+ */
+const struct inode_operations isofs_dir_inode_operations =
+{
+	.lookup = isofs_lookup,
+};
+
+
diff --git a/fs/isofs/export.c b/fs/isofs/export.c
new file mode 100644
index 000000000..35768a63f
--- /dev/null
+++ b/fs/isofs/export.c
@@ -0,0 +1,193 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * fs/isofs/export.c
+ *
+ *  (C) 2004  Paul Serice - The new inode scheme requires switching
+ *                          from iget() to iget5_locked() which means
+ *                          the NFS export operations have to be hand
+ *                          coded because the default routines rely on
+ *                          iget().
+ *
+ * The following files are helpful:
+ *
+ *     Documentation/filesystems/nfs/exporting.rst
+ *     fs/exportfs/expfs.c.
+ */
+
+#include "isofs.h"
+
+static struct dentry *
+isofs_export_iget(struct super_block *sb,
+		  unsigned long block,
+		  unsigned long offset,
+		  __u32 generation)
+{
+	struct inode *inode;
+
+	if (block == 0)
+		return ERR_PTR(-ESTALE);
+	inode = isofs_iget(sb, block, offset);
+	if (IS_ERR(inode))
+		return ERR_CAST(inode);
+	if (generation && inode->i_generation != generation) {
+		iput(inode);
+		return ERR_PTR(-ESTALE);
+	}
+	return d_obtain_alias(inode);
+}
+
+/* This function is surprisingly simple.  The trick is understanding
+ * that "child" is always a directory. So, to find its parent, you
+ * simply need to find its ".." entry, normalize its block and offset,
+ * and return the underlying inode.  See the comments for
+ * isofs_normalize_block_and_offset(). */
+static struct dentry *isofs_export_get_parent(struct dentry *child)
+{
+	unsigned long parent_block = 0;
+	unsigned long parent_offset = 0;
+	struct inode *child_inode = d_inode(child);
+	struct iso_inode_info *e_child_inode = ISOFS_I(child_inode);
+	struct iso_directory_record *de = NULL;
+	struct buffer_head * bh = NULL;
+	struct dentry *rv = NULL;
+
+	/* "child" must always be a directory. */
+	if (!S_ISDIR(child_inode->i_mode)) {
+		printk(KERN_ERR "isofs: isofs_export_get_parent(): "
+		       "child is not a directory!\n");
+		rv = ERR_PTR(-EACCES);
+		goto out;
+	}
+
+	/* It is an invariant that the directory offset is zero.  If
+	 * it is not zero, it means the directory failed to be
+	 * normalized for some reason. */
+	if (e_child_inode->i_iget5_offset != 0) {
+		printk(KERN_ERR "isofs: isofs_export_get_parent(): "
+		       "child directory not normalized!\n");
+		rv = ERR_PTR(-EACCES);
+		goto out;
+	}
+
+	/* The child inode has been normalized such that its
+	 * i_iget5_block value points to the "." entry.  Fortunately,
+	 * the ".." entry is located in the same block. */
+	parent_block = e_child_inode->i_iget5_block;
+
+	/* Get the block in question. */
+	bh = sb_bread(child_inode->i_sb, parent_block);
+	if (bh == NULL) {
+		rv = ERR_PTR(-EACCES);
+		goto out;
+	}
+
+	/* This is the "." entry. */
+	de = (struct iso_directory_record*)bh->b_data;
+
+	/* The ".." entry is always the second entry. */
+	parent_offset = (unsigned long)isonum_711(de->length);
+	de = (struct iso_directory_record*)(bh->b_data + parent_offset);
+
+	/* Verify it is in fact the ".." entry. */
+	if ((isonum_711(de->name_len) != 1) || (de->name[0] != 1)) {
+		printk(KERN_ERR "isofs: Unable to find the \"..\" "
+		       "directory for NFS.\n");
+		rv = ERR_PTR(-EACCES);
+		goto out;
+	}
+
+	/* Normalize */
+	isofs_normalize_block_and_offset(de, &parent_block, &parent_offset);
+
+	rv = d_obtain_alias(isofs_iget(child_inode->i_sb, parent_block,
+				     parent_offset));
+ out:
+	if (bh)
+		brelse(bh);
+	return rv;
+}
+
+static int
+isofs_export_encode_fh(struct inode *inode,
+		       __u32 *fh32,
+		       int *max_len,
+		       struct inode *parent)
+{
+	struct iso_inode_info * ei = ISOFS_I(inode);
+	int len = *max_len;
+	int type = 1;
+	__u16 *fh16 = (__u16*)fh32;
+
+	/*
+	 * WARNING: max_len is 5 for NFSv2.  Because of this
+	 * limitation, we use the lower 16 bits of fh32[1] to hold the
+	 * offset of the inode and the upper 16 bits of fh32[1] to
+	 * hold the offset of the parent.
+	 */
+	if (parent && (len < 5)) {
+		*max_len = 5;
+		return FILEID_INVALID;
+	} else if (len < 3) {
+		*max_len = 3;
+		return FILEID_INVALID;
+	}
+
+	len = 3;
+	fh32[0] = ei->i_iget5_block;
+ 	fh16[2] = (__u16)ei->i_iget5_offset;  /* fh16 [sic] */
+	fh16[3] = 0;  /* avoid leaking uninitialized data */
+	fh32[2] = inode->i_generation;
+	if (parent) {
+		struct iso_inode_info *eparent;
+		eparent = ISOFS_I(parent);
+		fh32[3] = eparent->i_iget5_block;
+		fh16[3] = (__u16)eparent->i_iget5_offset;  /* fh16 [sic] */
+		fh32[4] = parent->i_generation;
+		len = 5;
+		type = 2;
+	}
+	*max_len = len;
+	return type;
+}
+
+struct isofs_fid {
+	u32 block;
+	u16 offset;
+	u16 parent_offset;
+	u32 generation;
+	u32 parent_block;
+	u32 parent_generation;
+};
+
+static struct dentry *isofs_fh_to_dentry(struct super_block *sb,
+	struct fid *fid, int fh_len, int fh_type)
+{
+	struct isofs_fid *ifid = (struct isofs_fid *)fid;
+
+	if (fh_len < 3 || fh_type > 2)
+		return NULL;
+
+	return isofs_export_iget(sb, ifid->block, ifid->offset,
+			ifid->generation);
+}
+
+static struct dentry *isofs_fh_to_parent(struct super_block *sb,
+		struct fid *fid, int fh_len, int fh_type)
+{
+	struct isofs_fid *ifid = (struct isofs_fid *)fid;
+
+	if (fh_len < 2 || fh_type != 2)
+		return NULL;
+
+	return isofs_export_iget(sb,
+			fh_len > 2 ? ifid->parent_block : 0,
+			ifid->parent_offset,
+			fh_len > 4 ? ifid->parent_generation : 0);
+}
+
+const struct export_operations isofs_export_ops = {
+	.encode_fh	= isofs_export_encode_fh,
+	.fh_to_dentry	= isofs_fh_to_dentry,
+	.fh_to_parent	= isofs_fh_to_parent,
+	.get_parent     = isofs_export_get_parent,
+};
diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c
new file mode 100644
index 000000000..df9d70588
--- /dev/null
+++ b/fs/isofs/inode.c
@@ -0,0 +1,1612 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/fs/isofs/inode.c
+ *
+ *  (C) 1991  Linus Torvalds - minix filesystem
+ *      1992, 1993, 1994  Eric Youngdale Modified for ISO 9660 filesystem.
+ *      1994  Eberhard Mönkeberg - multi session handling.
+ *      1995  Mark Dobie - allow mounting of some weird VideoCDs and PhotoCDs.
+ *	1997  Gordon Chaffee - Joliet CDs
+ *	1998  Eric Lammerts - ISO 9660 Level 3
+ *	2004  Paul Serice - Inode Support pushed out from 4GB to 128GB
+ *	2004  Paul Serice - NFS Export Operations
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+
+#include <linux/slab.h>
+#include <linux/cred.h>
+#include <linux/nls.h>
+#include <linux/ctype.h>
+#include <linux/statfs.h>
+#include <linux/cdrom.h>
+#include <linux/parser.h>
+#include <linux/mpage.h>
+#include <linux/user_namespace.h>
+#include <linux/seq_file.h>
+#include <linux/blkdev.h>
+
+#include "isofs.h"
+#include "zisofs.h"
+
+/* max tz offset is 13 hours */
+#define MAX_TZ_OFFSET (52*15*60)
+
+#define BEQUIET
+
+static int isofs_hashi(const struct dentry *parent, struct qstr *qstr);
+static int isofs_dentry_cmpi(const struct dentry *dentry,
+		unsigned int len, const char *str, const struct qstr *name);
+
+#ifdef CONFIG_JOLIET
+static int isofs_hashi_ms(const struct dentry *parent, struct qstr *qstr);
+static int isofs_hash_ms(const struct dentry *parent, struct qstr *qstr);
+static int isofs_dentry_cmpi_ms(const struct dentry *dentry,
+		unsigned int len, const char *str, const struct qstr *name);
+static int isofs_dentry_cmp_ms(const struct dentry *dentry,
+		unsigned int len, const char *str, const struct qstr *name);
+#endif
+
+static void isofs_put_super(struct super_block *sb)
+{
+	struct isofs_sb_info *sbi = ISOFS_SB(sb);
+
+#ifdef CONFIG_JOLIET
+	unload_nls(sbi->s_nls_iocharset);
+#endif
+
+	kfree(sbi);
+	sb->s_fs_info = NULL;
+	return;
+}
+
+static int isofs_read_inode(struct inode *, int relocated);
+static int isofs_statfs (struct dentry *, struct kstatfs *);
+static int isofs_show_options(struct seq_file *, struct dentry *);
+
+static struct kmem_cache *isofs_inode_cachep;
+
+static struct inode *isofs_alloc_inode(struct super_block *sb)
+{
+	struct iso_inode_info *ei;
+	ei = alloc_inode_sb(sb, isofs_inode_cachep, GFP_KERNEL);
+	if (!ei)
+		return NULL;
+	return &ei->vfs_inode;
+}
+
+static void isofs_free_inode(struct inode *inode)
+{
+	kmem_cache_free(isofs_inode_cachep, ISOFS_I(inode));
+}
+
+static void init_once(void *foo)
+{
+	struct iso_inode_info *ei = foo;
+
+	inode_init_once(&ei->vfs_inode);
+}
+
+static int __init init_inodecache(void)
+{
+	isofs_inode_cachep = kmem_cache_create("isofs_inode_cache",
+					sizeof(struct iso_inode_info),
+					0, (SLAB_RECLAIM_ACCOUNT|
+					SLAB_MEM_SPREAD|SLAB_ACCOUNT),
+					init_once);
+	if (!isofs_inode_cachep)
+		return -ENOMEM;
+	return 0;
+}
+
+static void destroy_inodecache(void)
+{
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
+	kmem_cache_destroy(isofs_inode_cachep);
+}
+
+static int isofs_remount(struct super_block *sb, int *flags, char *data)
+{
+	sync_filesystem(sb);
+	if (!(*flags & SB_RDONLY))
+		return -EROFS;
+	return 0;
+}
+
+static const struct super_operations isofs_sops = {
+	.alloc_inode	= isofs_alloc_inode,
+	.free_inode	= isofs_free_inode,
+	.put_super	= isofs_put_super,
+	.statfs		= isofs_statfs,
+	.remount_fs	= isofs_remount,
+	.show_options	= isofs_show_options,
+};
+
+
+static const struct dentry_operations isofs_dentry_ops[] = {
+	{
+		.d_hash		= isofs_hashi,
+		.d_compare	= isofs_dentry_cmpi,
+	},
+#ifdef CONFIG_JOLIET
+	{
+		.d_hash		= isofs_hash_ms,
+		.d_compare	= isofs_dentry_cmp_ms,
+	},
+	{
+		.d_hash		= isofs_hashi_ms,
+		.d_compare	= isofs_dentry_cmpi_ms,
+	},
+#endif
+};
+
+struct iso9660_options{
+	unsigned int rock:1;
+	unsigned int joliet:1;
+	unsigned int cruft:1;
+	unsigned int hide:1;
+	unsigned int showassoc:1;
+	unsigned int nocompress:1;
+	unsigned int overriderockperm:1;
+	unsigned int uid_set:1;
+	unsigned int gid_set:1;
+	unsigned char map;
+	unsigned char check;
+	unsigned int blocksize;
+	umode_t fmode;
+	umode_t dmode;
+	kgid_t gid;
+	kuid_t uid;
+	char *iocharset;
+	/* LVE */
+	s32 session;
+	s32 sbsector;
+};
+
+/*
+ * Compute the hash for the isofs name corresponding to the dentry.
+ */
+static int
+isofs_hashi_common(const struct dentry *dentry, struct qstr *qstr, int ms)
+{
+	const char *name;
+	int len;
+	char c;
+	unsigned long hash;
+
+	len = qstr->len;
+	name = qstr->name;
+	if (ms) {
+		while (len && name[len-1] == '.')
+			len--;
+	}
+
+	hash = init_name_hash(dentry);
+	while (len--) {
+		c = tolower(*name++);
+		hash = partial_name_hash(c, hash);
+	}
+	qstr->hash = end_name_hash(hash);
+
+	return 0;
+}
+
+/*
+ * Compare of two isofs names.
+ */
+static int isofs_dentry_cmp_common(
+		unsigned int len, const char *str,
+		const struct qstr *name, int ms, int ci)
+{
+	int alen, blen;
+
+	/* A filename cannot end in '.' or we treat it like it has none */
+	alen = name->len;
+	blen = len;
+	if (ms) {
+		while (alen && name->name[alen-1] == '.')
+			alen--;
+		while (blen && str[blen-1] == '.')
+			blen--;
+	}
+	if (alen == blen) {
+		if (ci) {
+			if (strncasecmp(name->name, str, alen) == 0)
+				return 0;
+		} else {
+			if (strncmp(name->name, str, alen) == 0)
+				return 0;
+		}
+	}
+	return 1;
+}
+
+static int
+isofs_hashi(const struct dentry *dentry, struct qstr *qstr)
+{
+	return isofs_hashi_common(dentry, qstr, 0);
+}
+
+static int
+isofs_dentry_cmpi(const struct dentry *dentry,
+		unsigned int len, const char *str, const struct qstr *name)
+{
+	return isofs_dentry_cmp_common(len, str, name, 0, 1);
+}
+
+#ifdef CONFIG_JOLIET
+/*
+ * Compute the hash for the isofs name corresponding to the dentry.
+ */
+static int
+isofs_hash_common(const struct dentry *dentry, struct qstr *qstr, int ms)
+{
+	const char *name;
+	int len;
+
+	len = qstr->len;
+	name = qstr->name;
+	if (ms) {
+		while (len && name[len-1] == '.')
+			len--;
+	}
+
+	qstr->hash = full_name_hash(dentry, name, len);
+
+	return 0;
+}
+
+static int
+isofs_hash_ms(const struct dentry *dentry, struct qstr *qstr)
+{
+	return isofs_hash_common(dentry, qstr, 1);
+}
+
+static int
+isofs_hashi_ms(const struct dentry *dentry, struct qstr *qstr)
+{
+	return isofs_hashi_common(dentry, qstr, 1);
+}
+
+static int
+isofs_dentry_cmp_ms(const struct dentry *dentry,
+		unsigned int len, const char *str, const struct qstr *name)
+{
+	return isofs_dentry_cmp_common(len, str, name, 1, 0);
+}
+
+static int
+isofs_dentry_cmpi_ms(const struct dentry *dentry,
+		unsigned int len, const char *str, const struct qstr *name)
+{
+	return isofs_dentry_cmp_common(len, str, name, 1, 1);
+}
+#endif
+
+enum {
+	Opt_block, Opt_check_r, Opt_check_s, Opt_cruft, Opt_gid, Opt_ignore,
+	Opt_iocharset, Opt_map_a, Opt_map_n, Opt_map_o, Opt_mode, Opt_nojoliet,
+	Opt_norock, Opt_sb, Opt_session, Opt_uid, Opt_unhide, Opt_utf8, Opt_err,
+	Opt_nocompress, Opt_hide, Opt_showassoc, Opt_dmode, Opt_overriderockperm,
+};
+
+static const match_table_t tokens = {
+	{Opt_norock, "norock"},
+	{Opt_nojoliet, "nojoliet"},
+	{Opt_unhide, "unhide"},
+	{Opt_hide, "hide"},
+	{Opt_showassoc, "showassoc"},
+	{Opt_cruft, "cruft"},
+	{Opt_utf8, "utf8"},
+	{Opt_iocharset, "iocharset=%s"},
+	{Opt_map_a, "map=acorn"},
+	{Opt_map_a, "map=a"},
+	{Opt_map_n, "map=normal"},
+	{Opt_map_n, "map=n"},
+	{Opt_map_o, "map=off"},
+	{Opt_map_o, "map=o"},
+	{Opt_session, "session=%u"},
+	{Opt_sb, "sbsector=%u"},
+	{Opt_check_r, "check=relaxed"},
+	{Opt_check_r, "check=r"},
+	{Opt_check_s, "check=strict"},
+	{Opt_check_s, "check=s"},
+	{Opt_uid, "uid=%u"},
+	{Opt_gid, "gid=%u"},
+	{Opt_mode, "mode=%u"},
+	{Opt_dmode, "dmode=%u"},
+	{Opt_overriderockperm, "overriderockperm"},
+	{Opt_block, "block=%u"},
+	{Opt_ignore, "conv=binary"},
+	{Opt_ignore, "conv=b"},
+	{Opt_ignore, "conv=text"},
+	{Opt_ignore, "conv=t"},
+	{Opt_ignore, "conv=mtext"},
+	{Opt_ignore, "conv=m"},
+	{Opt_ignore, "conv=auto"},
+	{Opt_ignore, "conv=a"},
+	{Opt_nocompress, "nocompress"},
+	{Opt_err, NULL}
+};
+
+static int parse_options(char *options, struct iso9660_options *popt)
+{
+	char *p;
+	int option;
+	unsigned int uv;
+
+	popt->map = 'n';
+	popt->rock = 1;
+	popt->joliet = 1;
+	popt->cruft = 0;
+	popt->hide = 0;
+	popt->showassoc = 0;
+	popt->check = 'u';		/* unset */
+	popt->nocompress = 0;
+	popt->blocksize = 1024;
+	popt->fmode = popt->dmode = ISOFS_INVALID_MODE;
+	popt->uid_set = 0;
+	popt->gid_set = 0;
+	popt->gid = GLOBAL_ROOT_GID;
+	popt->uid = GLOBAL_ROOT_UID;
+	popt->iocharset = NULL;
+	popt->overriderockperm = 0;
+	popt->session=-1;
+	popt->sbsector=-1;
+	if (!options)
+		return 1;
+
+	while ((p = strsep(&options, ",")) != NULL) {
+		int token;
+		substring_t args[MAX_OPT_ARGS];
+		unsigned n;
+
+		if (!*p)
+			continue;
+
+		token = match_token(p, tokens, args);
+		switch (token) {
+		case Opt_norock:
+			popt->rock = 0;
+			break;
+		case Opt_nojoliet:
+			popt->joliet = 0;
+			break;
+		case Opt_hide:
+			popt->hide = 1;
+			break;
+		case Opt_unhide:
+		case Opt_showassoc:
+			popt->showassoc = 1;
+			break;
+		case Opt_cruft:
+			popt->cruft = 1;
+			break;
+#ifdef CONFIG_JOLIET
+		case Opt_utf8:
+			kfree(popt->iocharset);
+			popt->iocharset = kstrdup("utf8", GFP_KERNEL);
+			if (!popt->iocharset)
+				return 0;
+			break;
+		case Opt_iocharset:
+			kfree(popt->iocharset);
+			popt->iocharset = match_strdup(&args[0]);
+			if (!popt->iocharset)
+				return 0;
+			break;
+#endif
+		case Opt_map_a:
+			popt->map = 'a';
+			break;
+		case Opt_map_o:
+			popt->map = 'o';
+			break;
+		case Opt_map_n:
+			popt->map = 'n';
+			break;
+		case Opt_session:
+			if (match_int(&args[0], &option))
+				return 0;
+			n = option;
+			/*
+			 * Track numbers are supposed to be in range 1-99, the
+			 * mount option starts indexing at 0.
+			 */
+			if (n >= 99)
+				return 0;
+			popt->session = n + 1;
+			break;
+		case Opt_sb:
+			if (match_int(&args[0], &option))
+				return 0;
+			popt->sbsector = option;
+			break;
+		case Opt_check_r:
+			popt->check = 'r';
+			break;
+		case Opt_check_s:
+			popt->check = 's';
+			break;
+		case Opt_ignore:
+			break;
+		case Opt_uid:
+			if (match_uint(&args[0], &uv))
+				return 0;
+			popt->uid = make_kuid(current_user_ns(), uv);
+			if (!uid_valid(popt->uid))
+				return 0;
+			popt->uid_set = 1;
+			break;
+		case Opt_gid:
+			if (match_uint(&args[0], &uv))
+				return 0;
+			popt->gid = make_kgid(current_user_ns(), uv);
+			if (!gid_valid(popt->gid))
+				return 0;
+			popt->gid_set = 1;
+			break;
+		case Opt_mode:
+			if (match_int(&args[0], &option))
+				return 0;
+			popt->fmode = option;
+			break;
+		case Opt_dmode:
+			if (match_int(&args[0], &option))
+				return 0;
+			popt->dmode = option;
+			break;
+		case Opt_overriderockperm:
+			popt->overriderockperm = 1;
+			break;
+		case Opt_block:
+			if (match_int(&args[0], &option))
+				return 0;
+			n = option;
+			if (n != 512 && n != 1024 && n != 2048)
+				return 0;
+			popt->blocksize = n;
+			break;
+		case Opt_nocompress:
+			popt->nocompress = 1;
+			break;
+		default:
+			return 0;
+		}
+	}
+	return 1;
+}
+
+/*
+ * Display the mount options in /proc/mounts.
+ */
+static int isofs_show_options(struct seq_file *m, struct dentry *root)
+{
+	struct isofs_sb_info *sbi = ISOFS_SB(root->d_sb);
+
+	if (!sbi->s_rock)		seq_puts(m, ",norock");
+	else if (!sbi->s_joliet_level)	seq_puts(m, ",nojoliet");
+	if (sbi->s_cruft)		seq_puts(m, ",cruft");
+	if (sbi->s_hide)		seq_puts(m, ",hide");
+	if (sbi->s_nocompress)		seq_puts(m, ",nocompress");
+	if (sbi->s_overriderockperm)	seq_puts(m, ",overriderockperm");
+	if (sbi->s_showassoc)		seq_puts(m, ",showassoc");
+
+	if (sbi->s_check)		seq_printf(m, ",check=%c", sbi->s_check);
+	if (sbi->s_mapping)		seq_printf(m, ",map=%c", sbi->s_mapping);
+	if (sbi->s_session != 255)	seq_printf(m, ",session=%u", sbi->s_session - 1);
+	if (sbi->s_sbsector != -1)	seq_printf(m, ",sbsector=%u", sbi->s_sbsector);
+
+	if (root->d_sb->s_blocksize != 1024)
+		seq_printf(m, ",blocksize=%lu", root->d_sb->s_blocksize);
+
+	if (sbi->s_uid_set)
+		seq_printf(m, ",uid=%u",
+			   from_kuid_munged(&init_user_ns, sbi->s_uid));
+	if (sbi->s_gid_set)
+		seq_printf(m, ",gid=%u",
+			   from_kgid_munged(&init_user_ns, sbi->s_gid));
+
+	if (sbi->s_dmode != ISOFS_INVALID_MODE)
+		seq_printf(m, ",dmode=%o", sbi->s_dmode);
+	if (sbi->s_fmode != ISOFS_INVALID_MODE)
+		seq_printf(m, ",fmode=%o", sbi->s_fmode);
+
+#ifdef CONFIG_JOLIET
+	if (sbi->s_nls_iocharset)
+		seq_printf(m, ",iocharset=%s", sbi->s_nls_iocharset->charset);
+	else
+		seq_puts(m, ",iocharset=utf8");
+#endif
+	return 0;
+}
+
+/*
+ * look if the driver can tell the multi session redirection value
+ *
+ * don't change this if you don't know what you do, please!
+ * Multisession is legal only with XA disks.
+ * A non-XA disk with more than one volume descriptor may do it right, but
+ * usually is written in a nowhere standardized "multi-partition" manner.
+ * Multisession uses absolute addressing (solely the first frame of the whole
+ * track is #0), multi-partition uses relative addressing (each first frame of
+ * each track is #0), and a track is not a session.
+ *
+ * A broken CDwriter software or drive firmware does not set new standards,
+ * at least not if conflicting with the existing ones.
+ *
+ * emoenke@gwdg.de
+ */
+#define WE_OBEY_THE_WRITTEN_STANDARDS 1
+
+static unsigned int isofs_get_last_session(struct super_block *sb, s32 session)
+{
+	struct cdrom_device_info *cdi = disk_to_cdi(sb->s_bdev->bd_disk);
+	unsigned int vol_desc_start = 0;
+
+	if (session > 0) {
+		struct cdrom_tocentry te;
+
+		if (!cdi)
+			return 0;
+
+		te.cdte_track = session;
+		te.cdte_format = CDROM_LBA;
+		if (cdrom_read_tocentry(cdi, &te) == 0) {
+			printk(KERN_DEBUG "ISOFS: Session %d start %d type %d\n",
+				session, te.cdte_addr.lba,
+				te.cdte_ctrl & CDROM_DATA_TRACK);
+			if ((te.cdte_ctrl & CDROM_DATA_TRACK) == 4)
+				return te.cdte_addr.lba;
+		}
+
+		printk(KERN_ERR "ISOFS: Invalid session number or type of track\n");
+	}
+
+	if (cdi) {
+		struct cdrom_multisession ms_info;
+
+		ms_info.addr_format = CDROM_LBA;
+		if (cdrom_multisession(cdi, &ms_info) == 0) {
+#if WE_OBEY_THE_WRITTEN_STANDARDS
+			/* necessary for a valid ms_info.addr */
+			if (ms_info.xa_flag)
+#endif
+				vol_desc_start = ms_info.addr.lba;
+		}
+	}
+
+	return vol_desc_start;
+}
+
+/*
+ * Check if root directory is empty (has less than 3 files).
+ *
+ * Used to detect broken CDs where ISO root directory is empty but Joliet root
+ * directory is OK. If such CD has Rock Ridge extensions, they will be disabled
+ * (and Joliet used instead) or else no files would be visible.
+ */
+static bool rootdir_empty(struct super_block *sb, unsigned long block)
+{
+	int offset = 0, files = 0, de_len;
+	struct iso_directory_record *de;
+	struct buffer_head *bh;
+
+	bh = sb_bread(sb, block);
+	if (!bh)
+		return true;
+	while (files < 3) {
+		de = (struct iso_directory_record *) (bh->b_data + offset);
+		de_len = *(unsigned char *) de;
+		if (de_len == 0)
+			break;
+		files++;
+		offset += de_len;
+	}
+	brelse(bh);
+	return files < 3;
+}
+
+/*
+ * Initialize the superblock and read the root inode.
+ */
+static int isofs_fill_super(struct super_block *s, void *data, int silent)
+{
+	struct buffer_head *bh = NULL, *pri_bh = NULL;
+	struct hs_primary_descriptor *h_pri = NULL;
+	struct iso_primary_descriptor *pri = NULL;
+	struct iso_supplementary_descriptor *sec = NULL;
+	struct iso_directory_record *rootp;
+	struct inode *inode;
+	struct iso9660_options opt;
+	struct isofs_sb_info *sbi;
+	unsigned long first_data_zone;
+	int joliet_level = 0;
+	int iso_blknum, block;
+	int orig_zonesize;
+	int table, error = -EINVAL;
+	unsigned int vol_desc_start;
+
+	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
+	if (!sbi)
+		return -ENOMEM;
+	s->s_fs_info = sbi;
+
+	if (!parse_options((char *)data, &opt))
+		goto out_freesbi;
+
+	/*
+	 * First of all, get the hardware blocksize for this device.
+	 * If we don't know what it is, or the hardware blocksize is
+	 * larger than the blocksize the user specified, then use
+	 * that value.
+	 */
+	/*
+	 * What if bugger tells us to go beyond page size?
+	 */
+	if (bdev_logical_block_size(s->s_bdev) > 2048) {
+		printk(KERN_WARNING
+		       "ISOFS: unsupported/invalid hardware sector size %d\n",
+			bdev_logical_block_size(s->s_bdev));
+		goto out_freesbi;
+	}
+	opt.blocksize = sb_min_blocksize(s, opt.blocksize);
+
+	sbi->s_high_sierra = 0; /* default is iso9660 */
+	sbi->s_session = opt.session;
+	sbi->s_sbsector = opt.sbsector;
+
+	vol_desc_start = (opt.sbsector != -1) ?
+		opt.sbsector : isofs_get_last_session(s,opt.session);
+
+	for (iso_blknum = vol_desc_start+16;
+		iso_blknum < vol_desc_start+100; iso_blknum++) {
+		struct hs_volume_descriptor *hdp;
+		struct iso_volume_descriptor  *vdp;
+
+		block = iso_blknum << (ISOFS_BLOCK_BITS - s->s_blocksize_bits);
+		if (!(bh = sb_bread(s, block)))
+			goto out_no_read;
+
+		vdp = (struct iso_volume_descriptor *)bh->b_data;
+		hdp = (struct hs_volume_descriptor *)bh->b_data;
+
+		/*
+		 * Due to the overlapping physical location of the descriptors,
+		 * ISO CDs can match hdp->id==HS_STANDARD_ID as well. To ensure
+		 * proper identification in this case, we first check for ISO.
+		 */
+		if (strncmp (vdp->id, ISO_STANDARD_ID, sizeof vdp->id) == 0) {
+			if (isonum_711(vdp->type) == ISO_VD_END)
+				break;
+			if (isonum_711(vdp->type) == ISO_VD_PRIMARY) {
+				if (!pri) {
+					pri = (struct iso_primary_descriptor *)vdp;
+					/* Save the buffer in case we need it ... */
+					pri_bh = bh;
+					bh = NULL;
+				}
+			}
+#ifdef CONFIG_JOLIET
+			else if (isonum_711(vdp->type) == ISO_VD_SUPPLEMENTARY) {
+				sec = (struct iso_supplementary_descriptor *)vdp;
+				if (sec->escape[0] == 0x25 && sec->escape[1] == 0x2f) {
+					if (opt.joliet) {
+						if (sec->escape[2] == 0x40)
+							joliet_level = 1;
+						else if (sec->escape[2] == 0x43)
+							joliet_level = 2;
+						else if (sec->escape[2] == 0x45)
+							joliet_level = 3;
+
+						printk(KERN_DEBUG "ISO 9660 Extensions: "
+							"Microsoft Joliet Level %d\n",
+							joliet_level);
+					}
+					goto root_found;
+				} else {
+				/* Unknown supplementary volume descriptor */
+				sec = NULL;
+				}
+			}
+#endif
+		} else {
+			if (strncmp (hdp->id, HS_STANDARD_ID, sizeof hdp->id) == 0) {
+				if (isonum_711(hdp->type) != ISO_VD_PRIMARY)
+					goto out_freebh;
+
+				sbi->s_high_sierra = 1;
+				opt.rock = 0;
+				h_pri = (struct hs_primary_descriptor *)vdp;
+				goto root_found;
+			}
+		}
+
+		/* Just skip any volume descriptors we don't recognize */
+
+		brelse(bh);
+		bh = NULL;
+	}
+	/*
+	 * If we fall through, either no volume descriptor was found,
+	 * or else we passed a primary descriptor looking for others.
+	 */
+	if (!pri)
+		goto out_unknown_format;
+	brelse(bh);
+	bh = pri_bh;
+	pri_bh = NULL;
+
+root_found:
+	/* We don't support read-write mounts */
+	if (!sb_rdonly(s)) {
+		error = -EACCES;
+		goto out_freebh;
+	}
+
+	if (joliet_level && (!pri || !opt.rock)) {
+		/* This is the case of Joliet with the norock mount flag.
+		 * A disc with both Joliet and Rock Ridge is handled later
+		 */
+		pri = (struct iso_primary_descriptor *) sec;
+	}
+
+	if(sbi->s_high_sierra){
+		rootp = (struct iso_directory_record *) h_pri->root_directory_record;
+		sbi->s_nzones = isonum_733(h_pri->volume_space_size);
+		sbi->s_log_zone_size = isonum_723(h_pri->logical_block_size);
+		sbi->s_max_size = isonum_733(h_pri->volume_space_size);
+	} else {
+		if (!pri)
+			goto out_freebh;
+		rootp = (struct iso_directory_record *) pri->root_directory_record;
+		sbi->s_nzones = isonum_733(pri->volume_space_size);
+		sbi->s_log_zone_size = isonum_723(pri->logical_block_size);
+		sbi->s_max_size = isonum_733(pri->volume_space_size);
+	}
+
+	sbi->s_ninodes = 0; /* No way to figure this out easily */
+
+	orig_zonesize = sbi->s_log_zone_size;
+	/*
+	 * If the zone size is smaller than the hardware sector size,
+	 * this is a fatal error.  This would occur if the disc drive
+	 * had sectors that were 2048 bytes, but the filesystem had
+	 * blocks that were 512 bytes (which should only very rarely
+	 * happen.)
+	 */
+	if (orig_zonesize < opt.blocksize)
+		goto out_bad_size;
+
+	/* RDE: convert log zone size to bit shift */
+	switch (sbi->s_log_zone_size) {
+	case  512: sbi->s_log_zone_size =  9; break;
+	case 1024: sbi->s_log_zone_size = 10; break;
+	case 2048: sbi->s_log_zone_size = 11; break;
+
+	default:
+		goto out_bad_zone_size;
+	}
+
+	s->s_magic = ISOFS_SUPER_MAGIC;
+
+	/*
+	 * With multi-extent files, file size is only limited by the maximum
+	 * size of a file system, which is 8 TB.
+	 */
+	s->s_maxbytes = 0x80000000000LL;
+
+	/* ECMA-119 timestamp from 1900/1/1 with tz offset */
+	s->s_time_min = mktime64(1900, 1, 1, 0, 0, 0) - MAX_TZ_OFFSET;
+	s->s_time_max = mktime64(U8_MAX+1900, 12, 31, 23, 59, 59) + MAX_TZ_OFFSET;
+
+	/* Set this for reference. Its not currently used except on write
+	   which we don't have .. */
+
+	first_data_zone = isonum_733(rootp->extent) +
+			  isonum_711(rootp->ext_attr_length);
+	sbi->s_firstdatazone = first_data_zone;
+#ifndef BEQUIET
+	printk(KERN_DEBUG "ISOFS: Max size:%ld   Log zone size:%ld\n",
+		sbi->s_max_size, 1UL << sbi->s_log_zone_size);
+	printk(KERN_DEBUG "ISOFS: First datazone:%ld\n", sbi->s_firstdatazone);
+	if(sbi->s_high_sierra)
+		printk(KERN_DEBUG "ISOFS: Disc in High Sierra format.\n");
+#endif
+
+	/*
+	 * If the Joliet level is set, we _may_ decide to use the
+	 * secondary descriptor, but can't be sure until after we
+	 * read the root inode. But before reading the root inode
+	 * we may need to change the device blocksize, and would
+	 * rather release the old buffer first. So, we cache the
+	 * first_data_zone value from the secondary descriptor.
+	 */
+	if (joliet_level) {
+		pri = (struct iso_primary_descriptor *) sec;
+		rootp = (struct iso_directory_record *)
+			pri->root_directory_record;
+		first_data_zone = isonum_733(rootp->extent) +
+				isonum_711(rootp->ext_attr_length);
+	}
+
+	/*
+	 * We're all done using the volume descriptor, and may need
+	 * to change the device blocksize, so release the buffer now.
+	 */
+	brelse(pri_bh);
+	brelse(bh);
+
+	/*
+	 * Force the blocksize to 512 for 512 byte sectors.  The file
+	 * read primitives really get it wrong in a bad way if we don't
+	 * do this.
+	 *
+	 * Note - we should never be setting the blocksize to something
+	 * less than the hardware sector size for the device.  If we
+	 * do, we would end up having to read larger buffers and split
+	 * out portions to satisfy requests.
+	 *
+	 * Note2- the idea here is that we want to deal with the optimal
+	 * zonesize in the filesystem.  If we have it set to something less,
+	 * then we have horrible problems with trying to piece together
+	 * bits of adjacent blocks in order to properly read directory
+	 * entries.  By forcing the blocksize in this way, we ensure
+	 * that we will never be required to do this.
+	 */
+	sb_set_blocksize(s, orig_zonesize);
+
+	sbi->s_nls_iocharset = NULL;
+
+#ifdef CONFIG_JOLIET
+	if (joliet_level) {
+		char *p = opt.iocharset ? opt.iocharset : CONFIG_NLS_DEFAULT;
+		if (strcmp(p, "utf8") != 0) {
+			sbi->s_nls_iocharset = opt.iocharset ?
+				load_nls(opt.iocharset) : load_nls_default();
+			if (!sbi->s_nls_iocharset)
+				goto out_freesbi;
+		}
+	}
+#endif
+	s->s_op = &isofs_sops;
+	s->s_export_op = &isofs_export_ops;
+	sbi->s_mapping = opt.map;
+	sbi->s_rock = (opt.rock ? 2 : 0);
+	sbi->s_rock_offset = -1; /* initial offset, will guess until SP is found*/
+	sbi->s_cruft = opt.cruft;
+	sbi->s_hide = opt.hide;
+	sbi->s_showassoc = opt.showassoc;
+	sbi->s_uid = opt.uid;
+	sbi->s_gid = opt.gid;
+	sbi->s_uid_set = opt.uid_set;
+	sbi->s_gid_set = opt.gid_set;
+	sbi->s_nocompress = opt.nocompress;
+	sbi->s_overriderockperm = opt.overriderockperm;
+	/*
+	 * It would be incredibly stupid to allow people to mark every file
+	 * on the disk as suid, so we merely allow them to set the default
+	 * permissions.
+	 */
+	if (opt.fmode != ISOFS_INVALID_MODE)
+		sbi->s_fmode = opt.fmode & 0777;
+	else
+		sbi->s_fmode = ISOFS_INVALID_MODE;
+	if (opt.dmode != ISOFS_INVALID_MODE)
+		sbi->s_dmode = opt.dmode & 0777;
+	else
+		sbi->s_dmode = ISOFS_INVALID_MODE;
+
+	/*
+	 * Read the root inode, which _may_ result in changing
+	 * the s_rock flag. Once we have the final s_rock value,
+	 * we then decide whether to use the Joliet descriptor.
+	 */
+	inode = isofs_iget(s, sbi->s_firstdatazone, 0);
+	if (IS_ERR(inode))
+		goto out_no_root;
+
+	/*
+	 * Fix for broken CDs with Rock Ridge and empty ISO root directory but
+	 * correct Joliet root directory.
+	 */
+	if (sbi->s_rock == 1 && joliet_level &&
+				rootdir_empty(s, sbi->s_firstdatazone)) {
+		printk(KERN_NOTICE
+			"ISOFS: primary root directory is empty. "
+			"Disabling Rock Ridge and switching to Joliet.");
+		sbi->s_rock = 0;
+	}
+
+	/*
+	 * If this disk has both Rock Ridge and Joliet on it, then we
+	 * want to use Rock Ridge by default.  This can be overridden
+	 * by using the norock mount option.  There is still one other
+	 * possibility that is not taken into account: a Rock Ridge
+	 * CD with Unicode names.  Until someone sees such a beast, it
+	 * will not be supported.
+	 */
+	if (sbi->s_rock == 1) {
+		joliet_level = 0;
+	} else if (joliet_level) {
+		sbi->s_rock = 0;
+		if (sbi->s_firstdatazone != first_data_zone) {
+			sbi->s_firstdatazone = first_data_zone;
+			printk(KERN_DEBUG
+				"ISOFS: changing to secondary root\n");
+			iput(inode);
+			inode = isofs_iget(s, sbi->s_firstdatazone, 0);
+			if (IS_ERR(inode))
+				goto out_no_root;
+		}
+	}
+
+	if (opt.check == 'u') {
+		/* Only Joliet is case insensitive by default */
+		if (joliet_level)
+			opt.check = 'r';
+		else
+			opt.check = 's';
+	}
+	sbi->s_joliet_level = joliet_level;
+
+	/* Make sure the root inode is a directory */
+	if (!S_ISDIR(inode->i_mode)) {
+		printk(KERN_WARNING
+			"isofs_fill_super: root inode is not a directory. "
+			"Corrupted media?\n");
+		goto out_iput;
+	}
+
+	table = 0;
+	if (joliet_level)
+		table += 2;
+	if (opt.check == 'r')
+		table++;
+	sbi->s_check = opt.check;
+
+	if (table)
+		s->s_d_op = &isofs_dentry_ops[table - 1];
+
+	/* get the root dentry */
+	s->s_root = d_make_root(inode);
+	if (!(s->s_root)) {
+		error = -ENOMEM;
+		goto out_no_inode;
+	}
+
+	kfree(opt.iocharset);
+
+	return 0;
+
+	/*
+	 * Display error messages and free resources.
+	 */
+out_iput:
+	iput(inode);
+	goto out_no_inode;
+out_no_root:
+	error = PTR_ERR(inode);
+	if (error != -ENOMEM)
+		printk(KERN_WARNING "%s: get root inode failed\n", __func__);
+out_no_inode:
+#ifdef CONFIG_JOLIET
+	unload_nls(sbi->s_nls_iocharset);
+#endif
+	goto out_freesbi;
+out_no_read:
+	printk(KERN_WARNING "%s: bread failed, dev=%s, iso_blknum=%d, block=%d\n",
+		__func__, s->s_id, iso_blknum, block);
+	goto out_freebh;
+out_bad_zone_size:
+	printk(KERN_WARNING "ISOFS: Bad logical zone size %ld\n",
+		sbi->s_log_zone_size);
+	goto out_freebh;
+out_bad_size:
+	printk(KERN_WARNING "ISOFS: Logical zone size(%d) < hardware blocksize(%u)\n",
+		orig_zonesize, opt.blocksize);
+	goto out_freebh;
+out_unknown_format:
+	if (!silent)
+		printk(KERN_WARNING "ISOFS: Unable to identify CD-ROM format.\n");
+
+out_freebh:
+	brelse(bh);
+	brelse(pri_bh);
+out_freesbi:
+	kfree(opt.iocharset);
+	kfree(sbi);
+	s->s_fs_info = NULL;
+	return error;
+}
+
+static int isofs_statfs (struct dentry *dentry, struct kstatfs *buf)
+{
+	struct super_block *sb = dentry->d_sb;
+	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
+
+	buf->f_type = ISOFS_SUPER_MAGIC;
+	buf->f_bsize = sb->s_blocksize;
+	buf->f_blocks = (ISOFS_SB(sb)->s_nzones
+		<< (ISOFS_SB(sb)->s_log_zone_size - sb->s_blocksize_bits));
+	buf->f_bfree = 0;
+	buf->f_bavail = 0;
+	buf->f_files = ISOFS_SB(sb)->s_ninodes;
+	buf->f_ffree = 0;
+	buf->f_fsid = u64_to_fsid(id);
+	buf->f_namelen = NAME_MAX;
+	return 0;
+}
+
+/*
+ * Get a set of blocks; filling in buffer_heads if already allocated
+ * or getblk() if they are not.  Returns the number of blocks inserted
+ * (-ve == error.)
+ */
+int isofs_get_blocks(struct inode *inode, sector_t iblock,
+		     struct buffer_head **bh, unsigned long nblocks)
+{
+	unsigned long b_off = iblock;
+	unsigned offset, sect_size;
+	unsigned int firstext;
+	unsigned long nextblk, nextoff;
+	int section, rv, error;
+	struct iso_inode_info *ei = ISOFS_I(inode);
+
+	error = -EIO;
+	rv = 0;
+	if (iblock != b_off) {
+		printk(KERN_DEBUG "%s: block number too large\n", __func__);
+		goto abort;
+	}
+
+
+	offset = 0;
+	firstext = ei->i_first_extent;
+	sect_size = ei->i_section_size >> ISOFS_BUFFER_BITS(inode);
+	nextblk = ei->i_next_section_block;
+	nextoff = ei->i_next_section_offset;
+	section = 0;
+
+	while (nblocks) {
+		/* If we are *way* beyond the end of the file, print a message.
+		 * Access beyond the end of the file up to the next page boundary
+		 * is normal, however because of the way the page cache works.
+		 * In this case, we just return 0 so that we can properly fill
+		 * the page with useless information without generating any
+		 * I/O errors.
+		 */
+		if (b_off > ((inode->i_size + PAGE_SIZE - 1) >> ISOFS_BUFFER_BITS(inode))) {
+			printk(KERN_DEBUG "%s: block >= EOF (%lu, %llu)\n",
+				__func__, b_off,
+				(unsigned long long)inode->i_size);
+			goto abort;
+		}
+
+		/* On the last section, nextblk == 0, section size is likely to
+		 * exceed sect_size by a partial block, and access beyond the
+		 * end of the file will reach beyond the section size, too.
+		 */
+		while (nextblk && (b_off >= (offset + sect_size))) {
+			struct inode *ninode;
+
+			offset += sect_size;
+			ninode = isofs_iget(inode->i_sb, nextblk, nextoff);
+			if (IS_ERR(ninode)) {
+				error = PTR_ERR(ninode);
+				goto abort;
+			}
+			firstext  = ISOFS_I(ninode)->i_first_extent;
+			sect_size = ISOFS_I(ninode)->i_section_size >> ISOFS_BUFFER_BITS(ninode);
+			nextblk   = ISOFS_I(ninode)->i_next_section_block;
+			nextoff   = ISOFS_I(ninode)->i_next_section_offset;
+			iput(ninode);
+
+			if (++section > 100) {
+				printk(KERN_DEBUG "%s: More than 100 file sections ?!?"
+					" aborting...\n", __func__);
+				printk(KERN_DEBUG "%s: block=%lu firstext=%u sect_size=%u "
+					"nextblk=%lu nextoff=%lu\n", __func__,
+					b_off, firstext, (unsigned) sect_size,
+					nextblk, nextoff);
+				goto abort;
+			}
+		}
+
+		if (*bh) {
+			map_bh(*bh, inode->i_sb, firstext + b_off - offset);
+		} else {
+			*bh = sb_getblk(inode->i_sb, firstext+b_off-offset);
+			if (!*bh)
+				goto abort;
+		}
+		bh++;	/* Next buffer head */
+		b_off++;	/* Next buffer offset */
+		nblocks--;
+		rv++;
+	}
+
+	error = 0;
+abort:
+	return rv != 0 ? rv : error;
+}
+
+/*
+ * Used by the standard interfaces.
+ */
+static int isofs_get_block(struct inode *inode, sector_t iblock,
+		    struct buffer_head *bh_result, int create)
+{
+	int ret;
+
+	if (create) {
+		printk(KERN_DEBUG "%s: Kernel tries to allocate a block\n", __func__);
+		return -EROFS;
+	}
+
+	ret = isofs_get_blocks(inode, iblock, &bh_result, 1);
+	return ret < 0 ? ret : 0;
+}
+
+static int isofs_bmap(struct inode *inode, sector_t block)
+{
+	struct buffer_head dummy;
+	int error;
+
+	dummy.b_state = 0;
+	dummy.b_blocknr = -1000;
+	error = isofs_get_block(inode, block, &dummy, 0);
+	if (!error)
+		return dummy.b_blocknr;
+	return 0;
+}
+
+struct buffer_head *isofs_bread(struct inode *inode, sector_t block)
+{
+	sector_t blknr = isofs_bmap(inode, block);
+	if (!blknr)
+		return NULL;
+	return sb_bread(inode->i_sb, blknr);
+}
+
+static int isofs_read_folio(struct file *file, struct folio *folio)
+{
+	return mpage_read_folio(folio, isofs_get_block);
+}
+
+static void isofs_readahead(struct readahead_control *rac)
+{
+	mpage_readahead(rac, isofs_get_block);
+}
+
+static sector_t _isofs_bmap(struct address_space *mapping, sector_t block)
+{
+	return generic_block_bmap(mapping,block,isofs_get_block);
+}
+
+static const struct address_space_operations isofs_aops = {
+	.read_folio = isofs_read_folio,
+	.readahead = isofs_readahead,
+	.bmap = _isofs_bmap
+};
+
+static int isofs_read_level3_size(struct inode *inode)
+{
+	unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
+	int high_sierra = ISOFS_SB(inode->i_sb)->s_high_sierra;
+	struct buffer_head *bh = NULL;
+	unsigned long block, offset, block_saved, offset_saved;
+	int i = 0;
+	int more_entries = 0;
+	struct iso_directory_record *tmpde = NULL;
+	struct iso_inode_info *ei = ISOFS_I(inode);
+
+	inode->i_size = 0;
+
+	/* The first 16 blocks are reserved as the System Area.  Thus,
+	 * no inodes can appear in block 0.  We use this to flag that
+	 * this is the last section. */
+	ei->i_next_section_block = 0;
+	ei->i_next_section_offset = 0;
+
+	block = ei->i_iget5_block;
+	offset = ei->i_iget5_offset;
+
+	do {
+		struct iso_directory_record *de;
+		unsigned int de_len;
+
+		if (!bh) {
+			bh = sb_bread(inode->i_sb, block);
+			if (!bh)
+				goto out_noread;
+		}
+		de = (struct iso_directory_record *) (bh->b_data + offset);
+		de_len = *(unsigned char *) de;
+
+		if (de_len == 0) {
+			brelse(bh);
+			bh = NULL;
+			++block;
+			offset = 0;
+			continue;
+		}
+
+		block_saved = block;
+		offset_saved = offset;
+		offset += de_len;
+
+		/* Make sure we have a full directory entry */
+		if (offset >= bufsize) {
+			int slop = bufsize - offset + de_len;
+			if (!tmpde) {
+				tmpde = kmalloc(256, GFP_KERNEL);
+				if (!tmpde)
+					goto out_nomem;
+			}
+			memcpy(tmpde, de, slop);
+			offset &= bufsize - 1;
+			block++;
+			brelse(bh);
+			bh = NULL;
+			if (offset) {
+				bh = sb_bread(inode->i_sb, block);
+				if (!bh)
+					goto out_noread;
+				memcpy((void *)tmpde+slop, bh->b_data, offset);
+			}
+			de = tmpde;
+		}
+
+		inode->i_size += isonum_733(de->size);
+		if (i == 1) {
+			ei->i_next_section_block = block_saved;
+			ei->i_next_section_offset = offset_saved;
+		}
+
+		more_entries = de->flags[-high_sierra] & 0x80;
+
+		i++;
+		if (i > 100)
+			goto out_toomany;
+	} while (more_entries);
+out:
+	kfree(tmpde);
+	brelse(bh);
+	return 0;
+
+out_nomem:
+	brelse(bh);
+	return -ENOMEM;
+
+out_noread:
+	printk(KERN_INFO "ISOFS: unable to read i-node block %lu\n", block);
+	kfree(tmpde);
+	return -EIO;
+
+out_toomany:
+	printk(KERN_INFO "%s: More than 100 file sections ?!?, aborting...\n"
+		"isofs_read_level3_size: inode=%lu\n",
+		__func__, inode->i_ino);
+	goto out;
+}
+
+static int isofs_read_inode(struct inode *inode, int relocated)
+{
+	struct super_block *sb = inode->i_sb;
+	struct isofs_sb_info *sbi = ISOFS_SB(sb);
+	unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
+	unsigned long block;
+	int high_sierra = sbi->s_high_sierra;
+	struct buffer_head *bh;
+	struct iso_directory_record *de;
+	struct iso_directory_record *tmpde = NULL;
+	unsigned int de_len;
+	unsigned long offset;
+	struct iso_inode_info *ei = ISOFS_I(inode);
+	int ret = -EIO;
+
+	block = ei->i_iget5_block;
+	bh = sb_bread(inode->i_sb, block);
+	if (!bh)
+		goto out_badread;
+
+	offset = ei->i_iget5_offset;
+
+	de = (struct iso_directory_record *) (bh->b_data + offset);
+	de_len = *(unsigned char *) de;
+	if (de_len < sizeof(struct iso_directory_record))
+		goto fail;
+
+	if (offset + de_len > bufsize) {
+		int frag1 = bufsize - offset;
+
+		tmpde = kmalloc(de_len, GFP_KERNEL);
+		if (!tmpde) {
+			ret = -ENOMEM;
+			goto fail;
+		}
+		memcpy(tmpde, bh->b_data + offset, frag1);
+		brelse(bh);
+		bh = sb_bread(inode->i_sb, ++block);
+		if (!bh)
+			goto out_badread;
+		memcpy((char *)tmpde+frag1, bh->b_data, de_len - frag1);
+		de = tmpde;
+	}
+
+	inode->i_ino = isofs_get_ino(ei->i_iget5_block,
+					ei->i_iget5_offset,
+					ISOFS_BUFFER_BITS(inode));
+
+	/* Assume it is a normal-format file unless told otherwise */
+	ei->i_file_format = isofs_file_normal;
+
+	if (de->flags[-high_sierra] & 2) {
+		if (sbi->s_dmode != ISOFS_INVALID_MODE)
+			inode->i_mode = S_IFDIR | sbi->s_dmode;
+		else
+			inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
+		set_nlink(inode, 1);	/*
+					 * Set to 1.  We know there are 2, but
+					 * the find utility tries to optimize
+					 * if it is 2, and it screws up.  It is
+					 * easier to give 1 which tells find to
+					 * do it the hard way.
+					 */
+	} else {
+		if (sbi->s_fmode != ISOFS_INVALID_MODE) {
+			inode->i_mode = S_IFREG | sbi->s_fmode;
+		} else {
+			/*
+			 * Set default permissions: r-x for all.  The disc
+			 * could be shared with DOS machines so virtually
+			 * anything could be a valid executable.
+			 */
+			inode->i_mode = S_IFREG | S_IRUGO | S_IXUGO;
+		}
+		set_nlink(inode, 1);
+	}
+	inode->i_uid = sbi->s_uid;
+	inode->i_gid = sbi->s_gid;
+	inode->i_blocks = 0;
+
+	ei->i_format_parm[0] = 0;
+	ei->i_format_parm[1] = 0;
+	ei->i_format_parm[2] = 0;
+
+	ei->i_section_size = isonum_733(de->size);
+	if (de->flags[-high_sierra] & 0x80) {
+		ret = isofs_read_level3_size(inode);
+		if (ret < 0)
+			goto fail;
+		ret = -EIO;
+	} else {
+		ei->i_next_section_block = 0;
+		ei->i_next_section_offset = 0;
+		inode->i_size = isonum_733(de->size);
+	}
+
+	/*
+	 * Some dipshit decided to store some other bit of information
+	 * in the high byte of the file length.  Truncate size in case
+	 * this CDROM was mounted with the cruft option.
+	 */
+
+	if (sbi->s_cruft)
+		inode->i_size &= 0x00ffffff;
+
+	if (de->interleave[0]) {
+		printk(KERN_DEBUG "ISOFS: Interleaved files not (yet) supported.\n");
+		inode->i_size = 0;
+	}
+
+	/* I have no idea what file_unit_size is used for, so
+	   we will flag it for now */
+	if (de->file_unit_size[0] != 0) {
+		printk(KERN_DEBUG "ISOFS: File unit size != 0 for ISO file (%ld).\n",
+			inode->i_ino);
+	}
+
+	/* I have no idea what other flag bits are used for, so
+	   we will flag it for now */
+#ifdef DEBUG
+	if((de->flags[-high_sierra] & ~2)!= 0){
+		printk(KERN_DEBUG "ISOFS: Unusual flag settings for ISO file "
+				"(%ld %x).\n",
+			inode->i_ino, de->flags[-high_sierra]);
+	}
+#endif
+
+	inode->i_mtime.tv_sec =
+	inode->i_atime.tv_sec =
+	inode->i_ctime.tv_sec = iso_date(de->date, high_sierra);
+	inode->i_mtime.tv_nsec =
+	inode->i_atime.tv_nsec =
+	inode->i_ctime.tv_nsec = 0;
+
+	ei->i_first_extent = (isonum_733(de->extent) +
+			isonum_711(de->ext_attr_length));
+
+	/* Set the number of blocks for stat() - should be done before RR */
+	inode->i_blocks = (inode->i_size + 511) >> 9;
+
+	/*
+	 * Now test for possible Rock Ridge extensions which will override
+	 * some of these numbers in the inode structure.
+	 */
+
+	if (!high_sierra) {
+		parse_rock_ridge_inode(de, inode, relocated);
+		/* if we want uid/gid set, override the rock ridge setting */
+		if (sbi->s_uid_set)
+			inode->i_uid = sbi->s_uid;
+		if (sbi->s_gid_set)
+			inode->i_gid = sbi->s_gid;
+	}
+	/* Now set final access rights if overriding rock ridge setting */
+	if (S_ISDIR(inode->i_mode) && sbi->s_overriderockperm &&
+	    sbi->s_dmode != ISOFS_INVALID_MODE)
+		inode->i_mode = S_IFDIR | sbi->s_dmode;
+	if (S_ISREG(inode->i_mode) && sbi->s_overriderockperm &&
+	    sbi->s_fmode != ISOFS_INVALID_MODE)
+		inode->i_mode = S_IFREG | sbi->s_fmode;
+
+	/* Install the inode operations vector */
+	if (S_ISREG(inode->i_mode)) {
+		inode->i_fop = &generic_ro_fops;
+		switch (ei->i_file_format) {
+#ifdef CONFIG_ZISOFS
+		case isofs_file_compressed:
+			inode->i_data.a_ops = &zisofs_aops;
+			break;
+#endif
+		default:
+			inode->i_data.a_ops = &isofs_aops;
+			break;
+		}
+	} else if (S_ISDIR(inode->i_mode)) {
+		inode->i_op = &isofs_dir_inode_operations;
+		inode->i_fop = &isofs_dir_operations;
+	} else if (S_ISLNK(inode->i_mode)) {
+		inode->i_op = &page_symlink_inode_operations;
+		inode_nohighmem(inode);
+		inode->i_data.a_ops = &isofs_symlink_aops;
+	} else
+		/* XXX - parse_rock_ridge_inode() had already set i_rdev. */
+		init_special_inode(inode, inode->i_mode, inode->i_rdev);
+
+	ret = 0;
+out:
+	kfree(tmpde);
+	brelse(bh);
+	return ret;
+
+out_badread:
+	printk(KERN_WARNING "ISOFS: unable to read i-node block\n");
+fail:
+	goto out;
+}
+
+struct isofs_iget5_callback_data {
+	unsigned long block;
+	unsigned long offset;
+};
+
+static int isofs_iget5_test(struct inode *ino, void *data)
+{
+	struct iso_inode_info *i = ISOFS_I(ino);
+	struct isofs_iget5_callback_data *d =
+		(struct isofs_iget5_callback_data*)data;
+	return (i->i_iget5_block == d->block)
+		&& (i->i_iget5_offset == d->offset);
+}
+
+static int isofs_iget5_set(struct inode *ino, void *data)
+{
+	struct iso_inode_info *i = ISOFS_I(ino);
+	struct isofs_iget5_callback_data *d =
+		(struct isofs_iget5_callback_data*)data;
+	i->i_iget5_block = d->block;
+	i->i_iget5_offset = d->offset;
+	return 0;
+}
+
+/* Store, in the inode's containing structure, the block and block
+ * offset that point to the underlying meta-data for the inode.  The
+ * code below is otherwise similar to the iget() code in
+ * include/linux/fs.h */
+struct inode *__isofs_iget(struct super_block *sb,
+			   unsigned long block,
+			   unsigned long offset,
+			   int relocated)
+{
+	unsigned long hashval;
+	struct inode *inode;
+	struct isofs_iget5_callback_data data;
+	long ret;
+
+	if (offset >= 1ul << sb->s_blocksize_bits)
+		return ERR_PTR(-EINVAL);
+
+	data.block = block;
+	data.offset = offset;
+
+	hashval = (block << sb->s_blocksize_bits) | offset;
+
+	inode = iget5_locked(sb, hashval, &isofs_iget5_test,
+				&isofs_iget5_set, &data);
+
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+
+	if (inode->i_state & I_NEW) {
+		ret = isofs_read_inode(inode, relocated);
+		if (ret < 0) {
+			iget_failed(inode);
+			inode = ERR_PTR(ret);
+		} else {
+			unlock_new_inode(inode);
+		}
+	}
+
+	return inode;
+}
+
+static struct dentry *isofs_mount(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data)
+{
+	return mount_bdev(fs_type, flags, dev_name, data, isofs_fill_super);
+}
+
+static struct file_system_type iso9660_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "iso9660",
+	.mount		= isofs_mount,
+	.kill_sb	= kill_block_super,
+	.fs_flags	= FS_REQUIRES_DEV,
+};
+MODULE_ALIAS_FS("iso9660");
+MODULE_ALIAS("iso9660");
+
+static int __init init_iso9660_fs(void)
+{
+	int err = init_inodecache();
+	if (err)
+		goto out;
+#ifdef CONFIG_ZISOFS
+	err = zisofs_init();
+	if (err)
+		goto out1;
+#endif
+	err = register_filesystem(&iso9660_fs_type);
+	if (err)
+		goto out2;
+	return 0;
+out2:
+#ifdef CONFIG_ZISOFS
+	zisofs_cleanup();
+out1:
+#endif
+	destroy_inodecache();
+out:
+	return err;
+}
+
+static void __exit exit_iso9660_fs(void)
+{
+        unregister_filesystem(&iso9660_fs_type);
+#ifdef CONFIG_ZISOFS
+	zisofs_cleanup();
+#endif
+	destroy_inodecache();
+}
+
+module_init(init_iso9660_fs)
+module_exit(exit_iso9660_fs)
+MODULE_LICENSE("GPL");
diff --git a/fs/isofs/isofs.h b/fs/isofs/isofs.h
new file mode 100644
index 000000000..dcdc191ed
--- /dev/null
+++ b/fs/isofs/isofs.h
@@ -0,0 +1,201 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/fs.h>
+#include <linux/buffer_head.h>
+#include <linux/exportfs.h>
+#include <linux/iso_fs.h>
+#include <asm/unaligned.h>
+
+enum isofs_file_format {
+	isofs_file_normal = 0,
+	isofs_file_sparse = 1,
+	isofs_file_compressed = 2,
+};
+	
+/*
+ * iso fs inode data in memory
+ */
+struct iso_inode_info {
+	unsigned long i_iget5_block;
+	unsigned long i_iget5_offset;
+	unsigned int i_first_extent;
+	unsigned char i_file_format;
+	unsigned char i_format_parm[3];
+	unsigned long i_next_section_block;
+	unsigned long i_next_section_offset;
+	off_t i_section_size;
+	struct inode vfs_inode;
+};
+
+/*
+ * iso9660 super-block data in memory
+ */
+struct isofs_sb_info {
+	unsigned long s_ninodes;
+	unsigned long s_nzones;
+	unsigned long s_firstdatazone;
+	unsigned long s_log_zone_size;
+	unsigned long s_max_size;
+	
+	int           s_rock_offset; /* offset of SUSP fields within SU area */
+	s32           s_sbsector;
+	unsigned char s_joliet_level;
+	unsigned char s_mapping;
+	unsigned char s_check;
+	unsigned char s_session;
+	unsigned int  s_high_sierra:1;
+	unsigned int  s_rock:2;
+	unsigned int  s_cruft:1; /* Broken disks with high byte of length
+				  * containing junk */
+	unsigned int  s_nocompress:1;
+	unsigned int  s_hide:1;
+	unsigned int  s_showassoc:1;
+	unsigned int  s_overriderockperm:1;
+	unsigned int  s_uid_set:1;
+	unsigned int  s_gid_set:1;
+
+	umode_t s_fmode;
+	umode_t s_dmode;
+	kgid_t s_gid;
+	kuid_t s_uid;
+	struct nls_table *s_nls_iocharset; /* Native language support table */
+};
+
+#define ISOFS_INVALID_MODE ((umode_t) -1)
+
+static inline struct isofs_sb_info *ISOFS_SB(struct super_block *sb)
+{
+	return sb->s_fs_info;
+}
+
+static inline struct iso_inode_info *ISOFS_I(struct inode *inode)
+{
+	return container_of(inode, struct iso_inode_info, vfs_inode);
+}
+
+static inline int isonum_711(u8 *p)
+{
+	return *p;
+}
+static inline int isonum_712(s8 *p)
+{
+	return *p;
+}
+static inline unsigned int isonum_721(u8 *p)
+{
+	return get_unaligned_le16(p);
+}
+static inline unsigned int isonum_722(u8 *p)
+{
+	return get_unaligned_be16(p);
+}
+static inline unsigned int isonum_723(u8 *p)
+{
+	/* Ignore bigendian datum due to broken mastering programs */
+	return get_unaligned_le16(p);
+}
+static inline unsigned int isonum_731(u8 *p)
+{
+	return get_unaligned_le32(p);
+}
+static inline unsigned int isonum_732(u8 *p)
+{
+	return get_unaligned_be32(p);
+}
+static inline unsigned int isonum_733(u8 *p)
+{
+	/* Ignore bigendian datum due to broken mastering programs */
+	return get_unaligned_le32(p);
+}
+extern int iso_date(u8 *, int);
+
+struct inode;		/* To make gcc happy */
+
+extern int parse_rock_ridge_inode(struct iso_directory_record *, struct inode *, int relocated);
+extern int get_rock_ridge_filename(struct iso_directory_record *, char *, struct inode *);
+extern int isofs_name_translate(struct iso_directory_record *, char *, struct inode *);
+
+int get_joliet_filename(struct iso_directory_record *, unsigned char *, struct inode *);
+int get_acorn_filename(struct iso_directory_record *, char *, struct inode *);
+
+extern struct dentry *isofs_lookup(struct inode *, struct dentry *, unsigned int flags);
+extern struct buffer_head *isofs_bread(struct inode *, sector_t);
+extern int isofs_get_blocks(struct inode *, sector_t, struct buffer_head **, unsigned long);
+
+struct inode *__isofs_iget(struct super_block *sb,
+			   unsigned long block,
+			   unsigned long offset,
+			   int relocated);
+
+static inline struct inode *isofs_iget(struct super_block *sb,
+				       unsigned long block,
+				       unsigned long offset)
+{
+	return __isofs_iget(sb, block, offset, 0);
+}
+
+static inline struct inode *isofs_iget_reloc(struct super_block *sb,
+					     unsigned long block,
+					     unsigned long offset)
+{
+	return __isofs_iget(sb, block, offset, 1);
+}
+
+/* Because the inode number is no longer relevant to finding the
+ * underlying meta-data for an inode, we are free to choose a more
+ * convenient 32-bit number as the inode number.  The inode numbering
+ * scheme was recommended by Sergey Vlasov and Eric Lammerts. */
+static inline unsigned long isofs_get_ino(unsigned long block,
+					  unsigned long offset,
+					  unsigned long bufbits)
+{
+	return (block << (bufbits - 5)) | (offset >> 5);
+}
+
+/* Every directory can have many redundant directory entries scattered
+ * throughout the directory tree.  First there is the directory entry
+ * with the name of the directory stored in the parent directory.
+ * Then, there is the "." directory entry stored in the directory
+ * itself.  Finally, there are possibly many ".." directory entries
+ * stored in all the subdirectories.
+ *
+ * In order for the NFS get_parent() method to work and for the
+ * general consistency of the dcache, we need to make sure the
+ * "i_iget5_block" and "i_iget5_offset" all point to exactly one of
+ * the many redundant entries for each directory.  We normalize the
+ * block and offset by always making them point to the "."  directory.
+ *
+ * Notice that we do not use the entry for the directory with the name
+ * that is located in the parent directory.  Even though choosing this
+ * first directory is more natural, it is much easier to find the "."
+ * entry in the NFS get_parent() method because it is implicitly
+ * encoded in the "extent + ext_attr_length" fields of _all_ the
+ * redundant entries for the directory.  Thus, it can always be
+ * reached regardless of which directory entry you have in hand.
+ *
+ * This works because the "." entry is simply the first directory
+ * record when you start reading the file that holds all the directory
+ * records, and this file starts at "extent + ext_attr_length" blocks.
+ * Because the "." entry is always the first entry listed in the
+ * directories file, the normalized "offset" value is always 0.
+ *
+ * You should pass the directory entry in "de".  On return, "block"
+ * and "offset" will hold normalized values.  Only directories are
+ * affected making it safe to call even for non-directory file
+ * types. */
+static inline void
+isofs_normalize_block_and_offset(struct iso_directory_record* de,
+				 unsigned long *block,
+				 unsigned long *offset)
+{
+	/* Only directories are normalized. */
+	if (de->flags[0] & 2) {
+		*offset = 0;
+		*block = (unsigned long)isonum_733(de->extent)
+			+ (unsigned long)isonum_711(de->ext_attr_length);
+	}
+}
+
+extern const struct inode_operations isofs_dir_inode_operations;
+extern const struct file_operations isofs_dir_operations;
+extern const struct address_space_operations isofs_symlink_aops;
+extern const struct export_operations isofs_export_ops;
diff --git a/fs/isofs/joliet.c b/fs/isofs/joliet.c
new file mode 100644
index 000000000..c0f04a1e7
--- /dev/null
+++ b/fs/isofs/joliet.c
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/isofs/joliet.c
+ *
+ *  (C) 1996 Gordon Chaffee
+ *
+ *  Joliet: Microsoft's Unicode extensions to iso9660
+ */
+
+#include <linux/types.h>
+#include <linux/nls.h>
+#include "isofs.h"
+
+/*
+ * Convert Unicode 16 to UTF-8 or ASCII.
+ */
+static int
+uni16_to_x8(unsigned char *ascii, __be16 *uni, int len, struct nls_table *nls)
+{
+	__be16 *ip, ch;
+	unsigned char *op;
+
+	ip = uni;
+	op = ascii;
+
+	while ((ch = get_unaligned(ip)) && len) {
+		int llen;
+		llen = nls->uni2char(be16_to_cpu(ch), op, NLS_MAX_CHARSET_SIZE);
+		if (llen > 0)
+			op += llen;
+		else
+			*op++ = '?';
+		ip++;
+
+		len--;
+	}
+	*op = 0;
+	return (op - ascii);
+}
+
+int
+get_joliet_filename(struct iso_directory_record * de, unsigned char *outname, struct inode * inode)
+{
+	struct nls_table *nls;
+	unsigned char len = 0;
+
+	nls = ISOFS_SB(inode->i_sb)->s_nls_iocharset;
+
+	if (!nls) {
+		len = utf16s_to_utf8s((const wchar_t *) de->name,
+				de->name_len[0] >> 1, UTF16_BIG_ENDIAN,
+				outname, PAGE_SIZE);
+	} else {
+		len = uni16_to_x8(outname, (__be16 *) de->name,
+				de->name_len[0] >> 1, nls);
+	}
+	if ((len > 2) && (outname[len-2] == ';') && (outname[len-1] == '1'))
+		len -= 2;
+
+	/*
+	 * Windows doesn't like periods at the end of a name,
+	 * so neither do we
+	 */
+	while (len >= 2 && (outname[len-1] == '.'))
+		len--;
+
+	return len;
+}
diff --git a/fs/isofs/namei.c b/fs/isofs/namei.c
new file mode 100644
index 000000000..58f80e1b3
--- /dev/null
+++ b/fs/isofs/namei.c
@@ -0,0 +1,174 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/isofs/namei.c
+ *
+ *  (C) 1992  Eric Youngdale Modified for ISO 9660 filesystem.
+ *
+ *  (C) 1991  Linus Torvalds - minix filesystem
+ */
+
+#include <linux/gfp.h>
+#include "isofs.h"
+
+/*
+ * ok, we cannot use strncmp, as the name is not in our data space.
+ * Thus we'll have to use isofs_match. No big problem. Match also makes
+ * some sanity tests.
+ */
+static int
+isofs_cmp(struct dentry *dentry, const char *compare, int dlen)
+{
+	struct qstr qstr;
+	qstr.name = compare;
+	qstr.len = dlen;
+	if (likely(!dentry->d_op))
+		return dentry->d_name.len != dlen || memcmp(dentry->d_name.name, compare, dlen);
+	return dentry->d_op->d_compare(NULL, dentry->d_name.len, dentry->d_name.name, &qstr);
+}
+
+/*
+ *	isofs_find_entry()
+ *
+ * finds an entry in the specified directory with the wanted name. It
+ * returns the inode number of the found entry, or 0 on error.
+ */
+static unsigned long
+isofs_find_entry(struct inode *dir, struct dentry *dentry,
+	unsigned long *block_rv, unsigned long *offset_rv,
+	char *tmpname, struct iso_directory_record *tmpde)
+{
+	unsigned long bufsize = ISOFS_BUFFER_SIZE(dir);
+	unsigned char bufbits = ISOFS_BUFFER_BITS(dir);
+	unsigned long block, f_pos, offset, block_saved, offset_saved;
+	struct buffer_head *bh = NULL;
+	struct isofs_sb_info *sbi = ISOFS_SB(dir->i_sb);
+
+	if (!ISOFS_I(dir)->i_first_extent)
+		return 0;
+
+	f_pos = 0;
+	offset = 0;
+	block = 0;
+
+	while (f_pos < dir->i_size) {
+		struct iso_directory_record *de;
+		int de_len, match, i, dlen;
+		char *dpnt;
+
+		if (!bh) {
+			bh = isofs_bread(dir, block);
+			if (!bh)
+				return 0;
+		}
+
+		de = (struct iso_directory_record *) (bh->b_data + offset);
+
+		de_len = *(unsigned char *) de;
+		if (!de_len) {
+			brelse(bh);
+			bh = NULL;
+			f_pos = (f_pos + ISOFS_BLOCK_SIZE) & ~(ISOFS_BLOCK_SIZE - 1);
+			block = f_pos >> bufbits;
+			offset = 0;
+			continue;
+		}
+
+		block_saved = bh->b_blocknr;
+		offset_saved = offset;
+		offset += de_len;
+		f_pos += de_len;
+
+		/* Make sure we have a full directory entry */
+		if (offset >= bufsize) {
+			int slop = bufsize - offset + de_len;
+			memcpy(tmpde, de, slop);
+			offset &= bufsize - 1;
+			block++;
+			brelse(bh);
+			bh = NULL;
+			if (offset) {
+				bh = isofs_bread(dir, block);
+				if (!bh)
+					return 0;
+				memcpy((void *) tmpde + slop, bh->b_data, offset);
+			}
+			de = tmpde;
+		}
+
+		dlen = de->name_len[0];
+		dpnt = de->name;
+		/* Basic sanity check, whether name doesn't exceed dir entry */
+		if (de_len < dlen + sizeof(struct iso_directory_record)) {
+			printk(KERN_NOTICE "iso9660: Corrupted directory entry"
+			       " in block %lu of inode %lu\n", block,
+			       dir->i_ino);
+			brelse(bh);
+			return 0;
+		}
+
+		if (sbi->s_rock &&
+		    ((i = get_rock_ridge_filename(de, tmpname, dir)))) {
+			dlen = i;	/* possibly -1 */
+			dpnt = tmpname;
+#ifdef CONFIG_JOLIET
+		} else if (sbi->s_joliet_level) {
+			dlen = get_joliet_filename(de, tmpname, dir);
+			dpnt = tmpname;
+#endif
+		} else if (sbi->s_mapping == 'a') {
+			dlen = get_acorn_filename(de, tmpname, dir);
+			dpnt = tmpname;
+		} else if (sbi->s_mapping == 'n') {
+			dlen = isofs_name_translate(de, tmpname, dir);
+			dpnt = tmpname;
+		}
+
+		/*
+		 * Skip hidden or associated files unless hide or showassoc,
+		 * respectively, is set
+		 */
+		match = 0;
+		if (dlen > 0 &&
+			(!sbi->s_hide ||
+				(!(de->flags[-sbi->s_high_sierra] & 1))) &&
+			(sbi->s_showassoc ||
+				(!(de->flags[-sbi->s_high_sierra] & 4)))) {
+			if (dpnt && (dlen > 1 || dpnt[0] > 1))
+				match = (isofs_cmp(dentry, dpnt, dlen) == 0);
+		}
+		if (match) {
+			isofs_normalize_block_and_offset(de,
+							 &block_saved,
+							 &offset_saved);
+			*block_rv = block_saved;
+			*offset_rv = offset_saved;
+			brelse(bh);
+			return 1;
+		}
+	}
+	brelse(bh);
+	return 0;
+}
+
+struct dentry *isofs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
+{
+	int found;
+	unsigned long block;
+	unsigned long offset;
+	struct inode *inode;
+	struct page *page;
+
+	page = alloc_page(GFP_USER);
+	if (!page)
+		return ERR_PTR(-ENOMEM);
+
+	found = isofs_find_entry(dir, dentry,
+				&block, &offset,
+				page_address(page),
+				1024 + page_address(page));
+	__free_page(page);
+
+	inode = found ? isofs_iget(dir->i_sb, block, offset) : NULL;
+
+	return d_splice_alias(inode, dentry);
+}
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
+};
diff --git a/fs/isofs/rock.h b/fs/isofs/rock.h
new file mode 100644
index 000000000..ee9660e96
--- /dev/null
+++ b/fs/isofs/rock.h
@@ -0,0 +1,123 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * These structs are used by the system-use-sharing protocol, in which the
+ * Rock Ridge extensions are embedded.  It is quite possible that other
+ * extensions are present on the disk, and this is fine as long as they
+ * all use SUSP
+ */
+
+struct SU_SP_s {
+	__u8 magic[2];
+	__u8 skip;
+} __attribute__ ((packed));
+
+struct SU_CE_s {
+	__u8 extent[8];
+	__u8 offset[8];
+	__u8 size[8];
+};
+
+struct SU_ER_s {
+	__u8 len_id;
+	__u8 len_des;
+	__u8 len_src;
+	__u8 ext_ver;
+	__u8 data[];
+} __attribute__ ((packed));
+
+struct RR_RR_s {
+	__u8 flags[1];
+} __attribute__ ((packed));
+
+struct RR_PX_s {
+	__u8 mode[8];
+	__u8 n_links[8];
+	__u8 uid[8];
+	__u8 gid[8];
+};
+
+struct RR_PN_s {
+	__u8 dev_high[8];
+	__u8 dev_low[8];
+};
+
+struct SL_component {
+	__u8 flags;
+	__u8 len;
+	__u8 text[];
+} __attribute__ ((packed));
+
+struct RR_SL_s {
+	__u8 flags;
+	struct SL_component link;
+} __attribute__ ((packed));
+
+struct RR_NM_s {
+	__u8 flags;
+	char name[];
+} __attribute__ ((packed));
+
+struct RR_CL_s {
+	__u8 location[8];
+};
+
+struct RR_PL_s {
+	__u8 location[8];
+};
+
+struct stamp {
+	__u8 time[7];		/* actually 6 unsigned, 1 signed */
+} __attribute__ ((packed));
+
+struct RR_TF_s {
+	__u8 flags;
+	struct stamp times[];	/* Variable number of these beasts */
+} __attribute__ ((packed));
+
+/* Linux-specific extension for transparent decompression */
+struct RR_ZF_s {
+	__u8 algorithm[2];
+	__u8 parms[2];
+	__u8 real_size[8];
+};
+
+/*
+ * These are the bits and their meanings for flags in the TF structure.
+ */
+#define TF_CREATE 1
+#define TF_MODIFY 2
+#define TF_ACCESS 4
+#define TF_ATTRIBUTES 8
+#define TF_BACKUP 16
+#define TF_EXPIRATION 32
+#define TF_EFFECTIVE 64
+#define TF_LONG_FORM 128
+
+struct rock_ridge {
+	__u8 signature[2];
+	__u8 len;
+	__u8 version;
+	union {
+		struct SU_SP_s SP;
+		struct SU_CE_s CE;
+		struct SU_ER_s ER;
+		struct RR_RR_s RR;
+		struct RR_PX_s PX;
+		struct RR_PN_s PN;
+		struct RR_SL_s SL;
+		struct RR_NM_s NM;
+		struct RR_CL_s CL;
+		struct RR_PL_s PL;
+		struct RR_TF_s TF;
+		struct RR_ZF_s ZF;
+	} u;
+};
+
+#define RR_PX 1			/* POSIX attributes */
+#define RR_PN 2			/* POSIX devices */
+#define RR_SL 4			/* Symbolic link */
+#define RR_NM 8			/* Alternate Name */
+#define RR_CL 16		/* Child link */
+#define RR_PL 32		/* Parent link */
+#define RR_RE 64		/* Relocation directory */
+#define RR_TF 128		/* Timestamps */
diff --git a/fs/isofs/util.c b/fs/isofs/util.c
new file mode 100644
index 000000000..e88dba721
--- /dev/null
+++ b/fs/isofs/util.c
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/isofs/util.c
+ */
+
+#include <linux/time.h>
+#include "isofs.h"
+
+/* 
+ * We have to convert from a MM/DD/YY format to the Unix ctime format.
+ * We have to take into account leap years and all of that good stuff.
+ * Unfortunately, the kernel does not have the information on hand to
+ * take into account daylight savings time, but it shouldn't matter.
+ * The time stored should be localtime (with or without DST in effect),
+ * and the timezone offset should hold the offset required to get back
+ * to GMT.  Thus  we should always be correct.
+ */
+
+int iso_date(u8 *p, int flag)
+{
+	int year, month, day, hour, minute, second, tz;
+	int crtime;
+
+	year = p[0];
+	month = p[1];
+	day = p[2];
+	hour = p[3];
+	minute = p[4];
+	second = p[5];
+	if (flag == 0) tz = p[6]; /* High sierra has no time zone */
+	else tz = 0;
+	
+	if (year < 0) {
+		crtime = 0;
+	} else {
+		crtime = mktime64(year+1900, month, day, hour, minute, second);
+
+		/* sign extend */
+		if (tz & 0x80)
+			tz |= (-1 << 8);
+		
+		/* 
+		 * The timezone offset is unreliable on some disks,
+		 * so we make a sanity check.  In no case is it ever
+		 * more than 13 hours from GMT, which is 52*15min.
+		 * The time is always stored in localtime with the
+		 * timezone offset being what get added to GMT to
+		 * get to localtime.  Thus we need to subtract the offset
+		 * to get to true GMT, which is what we store the time
+		 * as internally.  On the local system, the user may set
+		 * their timezone any way they wish, of course, so GMT
+		 * gets converted back to localtime on the receiving
+		 * system.
+		 *
+		 * NOTE: mkisofs in versions prior to mkisofs-1.10 had
+		 * the sign wrong on the timezone offset.  This has now
+		 * been corrected there too, but if you are getting screwy
+		 * results this may be the explanation.  If enough people
+		 * complain, a user configuration option could be added
+		 * to add the timezone offset in with the wrong sign
+		 * for 'compatibility' with older discs, but I cannot see how
+		 * it will matter that much.
+		 *
+		 * Thanks to kuhlmav@elec.canterbury.ac.nz (Volker Kuhlmann)
+		 * for pointing out the sign error.
+		 */
+		if (-52 <= tz && tz <= 52)
+			crtime -= tz * 15 * 60;
+	}
+	return crtime;
+}		
diff --git a/fs/isofs/zisofs.h b/fs/isofs/zisofs.h
new file mode 100644
index 000000000..70f1a218f
--- /dev/null
+++ b/fs/isofs/zisofs.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* ----------------------------------------------------------------------- *
+ *   
+ *   Copyright 2001 H. Peter Anvin - All Rights Reserved
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Prototypes for functions exported from the compressed isofs subsystem
+ */
+
+#ifdef CONFIG_ZISOFS
+extern const struct address_space_operations zisofs_aops;
+extern int __init zisofs_init(void);
+extern void zisofs_cleanup(void);
+#endif