17 files changed, 1349 insertions, 1547 deletions

diff --git a/fs/udf/Kconfig b/fs/udf/Kconfig
index 26e1a49f3ba7..82e8bfa2dfd9 100644
--- a/fs/udf/Kconfig
+++ b/fs/udf/Kconfig
@@ -3,6 +3,7 @@ config UDF_FS
 	tristate "UDF file system support"
 	select CRC_ITU_T
 	select NLS
+	select LEGACY_DIRECT_IO
 	help
 	  This is a file system used on some CD-ROMs and DVDs. Since the
 	  file system is supported by multiple operating systems and is more
diff --git a/fs/udf/balloc.c b/fs/udf/balloc.c
index 8e597db4d971..14b9db4c80f0 100644
--- a/fs/udf/balloc.c
+++ b/fs/udf/balloc.c
@@ -36,18 +36,41 @@ static int read_block_bitmap(struct super_block *sb,
 			     unsigned long bitmap_nr)
 {
 	struct buffer_head *bh = NULL;
-	int retval = 0;
+	int i;
+	int max_bits, off, count;
 	struct kernel_lb_addr loc;
 
 	loc.logicalBlockNum = bitmap->s_extPosition;
 	loc.partitionReferenceNum = UDF_SB(sb)->s_partition;
 
-	bh = udf_tread(sb, udf_get_lb_pblock(sb, &loc, block));
+	bh = sb_bread(sb, udf_get_lb_pblock(sb, &loc, block));
+	bitmap->s_block_bitmap[bitmap_nr] = bh;
 	if (!bh)
-		retval = -EIO;
+		return -EIO;
 
-	bitmap->s_block_bitmap[bitmap_nr] = bh;
-	return retval;
+	/* Check consistency of Space Bitmap buffer. */
+	max_bits = sb->s_blocksize * 8;
+	if (!bitmap_nr) {
+		off = sizeof(struct spaceBitmapDesc) << 3;
+		count = min(max_bits - off, bitmap->s_nr_groups);
+	} else {
+		/*
+		 * Rough check if bitmap number is too big to have any bitmap
+ 		 * blocks reserved.
+		 */
+		if (bitmap_nr >
+		    (bitmap->s_nr_groups >> (sb->s_blocksize_bits + 3)) + 2)
+			return 0;
+		off = 0;
+		count = bitmap->s_nr_groups - bitmap_nr * max_bits +
+				(sizeof(struct spaceBitmapDesc) << 3);
+		count = min(count, max_bits);
+	}
+
+	for (i = 0; i < count; i++)
+		if (udf_test_bit(i + off, bh->b_data))
+			return -EFSCORRUPTED;
+	return 0;
 }
 
 static int __load_block_bitmap(struct super_block *sb,
diff --git a/fs/udf/dir.c b/fs/udf/dir.c
index be640f4b2f2c..212393b12c22 100644
--- a/fs/udf/dir.c
+++ b/fs/udf/dir.c
@@ -39,26 +39,13 @@
 static int udf_readdir(struct file *file, struct dir_context *ctx)
 {
 	struct inode *dir = file_inode(file);
-	struct udf_inode_info *iinfo = UDF_I(dir);
-	struct udf_fileident_bh fibh = { .sbh = NULL, .ebh = NULL};
-	struct fileIdentDesc *fi = NULL;
-	struct fileIdentDesc cfi;
-	udf_pblk_t block, iblock;
 	loff_t nf_pos, emit_pos = 0;
 	int flen;
-	unsigned char *fname = NULL, *copy_name = NULL;
-	unsigned char *nameptr;
-	uint16_t liu;
-	uint8_t lfi;
-	loff_t size = udf_ext0_offset(dir) + dir->i_size;
-	struct buffer_head *tmp, *bha[16];
-	struct kernel_lb_addr eloc;
-	uint32_t elen;
-	sector_t offset;
-	int i, num, ret = 0;
-	struct extent_position epos = { NULL, 0, {0, 0} };
+	unsigned char *fname = NULL;
+	int ret = 0;
 	struct super_block *sb = dir->i_sb;
 	bool pos_valid = false;
+	struct udf_fileident_iter iter;
 
 	if (ctx->pos == 0) {
 		if (!dir_emit_dot(file, ctx))
@@ -66,7 +53,7 @@ static int udf_readdir(struct file *file, struct dir_context *ctx)
 		ctx->pos = 1;
 	}
 	nf_pos = (ctx->pos - 1) << 2;
-	if (nf_pos >= size)
+	if (nf_pos >= dir->i_size)
 		goto out;
 
 	/*
@@ -90,138 +77,57 @@ static int udf_readdir(struct file *file, struct dir_context *ctx)
 		goto out;
 	}
 
-	if (nf_pos == 0)
-		nf_pos = udf_ext0_offset(dir);
-
-	fibh.soffset = fibh.eoffset = nf_pos & (sb->s_blocksize - 1);
-	if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
-		if (inode_bmap(dir, nf_pos >> sb->s_blocksize_bits,
-		    &epos, &eloc, &elen, &offset)
-		    != (EXT_RECORDED_ALLOCATED >> 30)) {
-			ret = -ENOENT;
-			goto out;
-		}
-		block = udf_get_lb_pblock(sb, &eloc, offset);
-		if ((++offset << sb->s_blocksize_bits) < elen) {
-			if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
-				epos.offset -= sizeof(struct short_ad);
-			else if (iinfo->i_alloc_type ==
-					ICBTAG_FLAG_AD_LONG)
-				epos.offset -= sizeof(struct long_ad);
-		} else {
-			offset = 0;
-		}
-
-		if (!(fibh.sbh = fibh.ebh = udf_tread(sb, block))) {
-			ret = -EIO;
-			goto out;
-		}
-
-		if (!(offset & ((16 >> (sb->s_blocksize_bits - 9)) - 1))) {
-			i = 16 >> (sb->s_blocksize_bits - 9);
-			if (i + offset > (elen >> sb->s_blocksize_bits))
-				i = (elen >> sb->s_blocksize_bits) - offset;
-			for (num = 0; i > 0; i--) {
-				block = udf_get_lb_pblock(sb, &eloc, offset + i);
-				tmp = udf_tgetblk(sb, block);
-				if (tmp && !buffer_uptodate(tmp) && !buffer_locked(tmp))
-					bha[num++] = tmp;
-				else
-					brelse(tmp);
-			}
-			if (num) {
-				bh_readahead_batch(num, bha, REQ_RAHEAD);
-				for (i = 0; i < num; i++)
-					brelse(bha[i]);
-			}
-		}
-	}
-
-	while (nf_pos < size) {
+	for (ret = udf_fiiter_init(&iter, dir, nf_pos);
+	     !ret && iter.pos < dir->i_size;
+	     ret = udf_fiiter_advance(&iter)) {
 		struct kernel_lb_addr tloc;
-		loff_t cur_pos = nf_pos;
+		udf_pblk_t iblock;
 
-		/* Update file position only if we got past the current one */
-		if (nf_pos >= emit_pos) {
-			ctx->pos = (nf_pos >> 2) + 1;
-			pos_valid = true;
-		}
-
-		fi = udf_fileident_read(dir, &nf_pos, &fibh, &cfi, &epos, &eloc,
-					&elen, &offset);
-		if (!fi)
-			goto out;
 		/* Still not at offset where user asked us to read from? */
-		if (cur_pos < emit_pos)
+		if (iter.pos < emit_pos)
 			continue;
 
-		liu = le16_to_cpu(cfi.lengthOfImpUse);
-		lfi = cfi.lengthFileIdent;
-
-		if (fibh.sbh == fibh.ebh) {
-			nameptr = udf_get_fi_ident(fi);
-		} else {
-			int poffset;	/* Unpaded ending offset */
-
-			poffset = fibh.soffset + sizeof(struct fileIdentDesc) + liu + lfi;
-
-			if (poffset >= lfi) {
-				nameptr = (char *)(fibh.ebh->b_data + poffset - lfi);
-			} else {
-				if (!copy_name) {
-					copy_name = kmalloc(UDF_NAME_LEN,
-							    GFP_NOFS);
-					if (!copy_name) {
-						ret = -ENOMEM;
-						goto out;
-					}
-				}
-				nameptr = copy_name;
-				memcpy(nameptr, udf_get_fi_ident(fi),
-				       lfi - poffset);
-				memcpy(nameptr + lfi - poffset,
-				       fibh.ebh->b_data, poffset);
-			}
-		}
+		/* Update file position only if we got past the current one */
+		pos_valid = true;
+		ctx->pos = (iter.pos >> 2) + 1;
 
-		if ((cfi.fileCharacteristics & FID_FILE_CHAR_DELETED) != 0) {
+		if (iter.fi.fileCharacteristics & FID_FILE_CHAR_DELETED) {
 			if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNDELETE))
 				continue;
 		}
 
-		if ((cfi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) != 0) {
+		if (iter.fi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) {
 			if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNHIDE))
 				continue;
 		}
 
-		if (cfi.fileCharacteristics & FID_FILE_CHAR_PARENT) {
+		if (iter.fi.fileCharacteristics & FID_FILE_CHAR_PARENT) {
 			if (!dir_emit_dotdot(file, ctx))
-				goto out;
+				goto out_iter;
 			continue;
 		}
 
-		flen = udf_get_filename(sb, nameptr, lfi, fname, UDF_NAME_LEN);
+		flen = udf_get_filename(sb, iter.name,
+				iter.fi.lengthFileIdent, fname, UDF_NAME_LEN);
 		if (flen < 0)
 			continue;
 
-		tloc = lelb_to_cpu(cfi.icb.extLocation);
+		tloc = lelb_to_cpu(iter.fi.icb.extLocation);
 		iblock = udf_get_lb_pblock(sb, &tloc, 0);
 		if (!dir_emit(ctx, fname, flen, iblock, DT_UNKNOWN))
-			goto out;
-	} /* end while */
-
-	ctx->pos = (nf_pos >> 2) + 1;
-	pos_valid = true;
+			goto out_iter;
+	}
 
+	if (!ret) {
+		ctx->pos = (iter.pos >> 2) + 1;
+		pos_valid = true;
+	}
+out_iter:
+	udf_fiiter_release(&iter);
 out:
 	if (pos_valid)
 		file->f_version = inode_query_iversion(dir);
-	if (fibh.sbh != fibh.ebh)
-		brelse(fibh.ebh);
-	brelse(fibh.sbh);
-	brelse(epos.bh);
 	kfree(fname);
-	kfree(copy_name);
 
 	return ret;
 }
diff --git a/fs/udf/directory.c b/fs/udf/directory.c
index 16bcf2c6b8b3..654536d2b609 100644
--- a/fs/udf/directory.c
+++ b/fs/udf/directory.c
@@ -17,183 +17,478 @@
 #include <linux/fs.h>
 #include <linux/string.h>
 #include <linux/bio.h>
+#include <linux/crc-itu-t.h>
+#include <linux/iversion.h>
 
-struct fileIdentDesc *udf_fileident_read(struct inode *dir, loff_t *nf_pos,
-					 struct udf_fileident_bh *fibh,
-					 struct fileIdentDesc *cfi,
-					 struct extent_position *epos,
-					 struct kernel_lb_addr *eloc, uint32_t *elen,
-					 sector_t *offset)
+static int udf_verify_fi(struct udf_fileident_iter *iter)
 {
-	struct fileIdentDesc *fi;
-	int i, num;
-	udf_pblk_t block;
-	struct buffer_head *tmp, *bha[16];
-	struct udf_inode_info *iinfo = UDF_I(dir);
-
-	fibh->soffset = fibh->eoffset;
+	unsigned int len;
+
+	if (iter->fi.descTag.tagIdent != cpu_to_le16(TAG_IDENT_FID)) {
+		udf_err(iter->dir->i_sb,
+			"directory (ino %lu) has entry at pos %llu with incorrect tag %x\n",
+			iter->dir->i_ino, (unsigned long long)iter->pos,
+			le16_to_cpu(iter->fi.descTag.tagIdent));
+		return -EFSCORRUPTED;
+	}
+	len = udf_dir_entry_len(&iter->fi);
+	if (le16_to_cpu(iter->fi.lengthOfImpUse) & 3) {
+		udf_err(iter->dir->i_sb,
+			"directory (ino %lu) has entry at pos %llu with unaligned length of impUse field\n",
+			iter->dir->i_ino, (unsigned long long)iter->pos);
+		return -EFSCORRUPTED;
+	}
+	/*
+	 * This is in fact allowed by the spec due to long impUse field but
+	 * we don't support it. If there is real media with this large impUse
+	 * field, support can be added.
+	 */
+	if (len > 1 << iter->dir->i_blkbits) {
+		udf_err(iter->dir->i_sb,
+			"directory (ino %lu) has too big (%u) entry at pos %llu\n",
+			iter->dir->i_ino, len, (unsigned long long)iter->pos);
+		return -EFSCORRUPTED;
+	}
+	if (iter->pos + len > iter->dir->i_size) {
+		udf_err(iter->dir->i_sb,
+			"directory (ino %lu) has entry past directory size at pos %llu\n",
+			iter->dir->i_ino, (unsigned long long)iter->pos);
+		return -EFSCORRUPTED;
+	}
+	if (udf_dir_entry_len(&iter->fi) !=
+	    sizeof(struct tag) + le16_to_cpu(iter->fi.descTag.descCRCLength)) {
+		udf_err(iter->dir->i_sb,
+			"directory (ino %lu) has entry where CRC length (%u) does not match entry length (%u)\n",
+			iter->dir->i_ino,
+			(unsigned)le16_to_cpu(iter->fi.descTag.descCRCLength),
+			(unsigned)(udf_dir_entry_len(&iter->fi) -
+							sizeof(struct tag)));
+		return -EFSCORRUPTED;
+	}
+	return 0;
+}
 
+static int udf_copy_fi(struct udf_fileident_iter *iter)
+{
+	struct udf_inode_info *iinfo = UDF_I(iter->dir);
+	u32 blksize = 1 << iter->dir->i_blkbits;
+	u32 off, len, nameoff;
+	int err;
+
+	/* Skip copying when we are at EOF */
+	if (iter->pos >= iter->dir->i_size) {
+		iter->name = NULL;
+		return 0;
+	}
+	if (iter->dir->i_size < iter->pos + sizeof(struct fileIdentDesc)) {
+		udf_err(iter->dir->i_sb,
+			"directory (ino %lu) has entry straddling EOF\n",
+			iter->dir->i_ino);
+		return -EFSCORRUPTED;
+	}
 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
-		fi = udf_get_fileident(iinfo->i_data -
-				       (iinfo->i_efe ?
-					sizeof(struct extendedFileEntry) :
-					sizeof(struct fileEntry)),
-				       dir->i_sb->s_blocksize,
-				       &(fibh->eoffset));
-		if (!fi)
-			return NULL;
-
-		*nf_pos += fibh->eoffset - fibh->soffset;
-
-		memcpy((uint8_t *)cfi, (uint8_t *)fi,
+		memcpy(&iter->fi, iinfo->i_data + iinfo->i_lenEAttr + iter->pos,
 		       sizeof(struct fileIdentDesc));
-
-		return fi;
+		err = udf_verify_fi(iter);
+		if (err < 0)
+			return err;
+		iter->name = iinfo->i_data + iinfo->i_lenEAttr + iter->pos +
+			sizeof(struct fileIdentDesc) +
+			le16_to_cpu(iter->fi.lengthOfImpUse);
+		return 0;
 	}
 
-	if (fibh->eoffset == dir->i_sb->s_blocksize) {
-		uint32_t lextoffset = epos->offset;
-		unsigned char blocksize_bits = dir->i_sb->s_blocksize_bits;
-
-		if (udf_next_aext(dir, epos, eloc, elen, 1) !=
-		    (EXT_RECORDED_ALLOCATED >> 30))
-			return NULL;
+	off = iter->pos & (blksize - 1);
+	len = min_t(int, sizeof(struct fileIdentDesc), blksize - off);
+	memcpy(&iter->fi, iter->bh[0]->b_data + off, len);
+	if (len < sizeof(struct fileIdentDesc))
+		memcpy((char *)(&iter->fi) + len, iter->bh[1]->b_data,
+		       sizeof(struct fileIdentDesc) - len);
+	err = udf_verify_fi(iter);
+	if (err < 0)
+		return err;
+
+	/* Handle directory entry name */
+	nameoff = off + sizeof(struct fileIdentDesc) +
+				le16_to_cpu(iter->fi.lengthOfImpUse);
+	if (off + udf_dir_entry_len(&iter->fi) <= blksize) {
+		iter->name = iter->bh[0]->b_data + nameoff;
+	} else if (nameoff >= blksize) {
+		iter->name = iter->bh[1]->b_data + (nameoff - blksize);
+	} else {
+		iter->name = iter->namebuf;
+		len = blksize - nameoff;
+		memcpy(iter->name, iter->bh[0]->b_data + nameoff, len);
+		memcpy(iter->name + len, iter->bh[1]->b_data,
+		       iter->fi.lengthFileIdent - len);
+	}
+	return 0;
+}
 
-		block = udf_get_lb_pblock(dir->i_sb, eloc, *offset);
+/* Readahead 8k once we are at 8k boundary */
+static void udf_readahead_dir(struct udf_fileident_iter *iter)
+{
+	unsigned int ralen = 16 >> (iter->dir->i_blkbits - 9);
+	struct buffer_head *tmp, *bha[16];
+	int i, num;
+	udf_pblk_t blk;
+
+	if (iter->loffset & (ralen - 1))
+		return;
+
+	if (iter->loffset + ralen > (iter->elen >> iter->dir->i_blkbits))
+		ralen = (iter->elen >> iter->dir->i_blkbits) - iter->loffset;
+	num = 0;
+	for (i = 0; i < ralen; i++) {
+		blk = udf_get_lb_pblock(iter->dir->i_sb, &iter->eloc,
+					iter->loffset + i);
+		tmp = sb_getblk(iter->dir->i_sb, blk);
+		if (tmp && !buffer_uptodate(tmp) && !buffer_locked(tmp))
+			bha[num++] = tmp;
+		else
+			brelse(tmp);
+	}
+	if (num) {
+		bh_readahead_batch(num, bha, REQ_RAHEAD);
+		for (i = 0; i < num; i++)
+			brelse(bha[i]);
+	}
+}
 
-		(*offset)++;
+static struct buffer_head *udf_fiiter_bread_blk(struct udf_fileident_iter *iter)
+{
+	udf_pblk_t blk;
 
-		if ((*offset << blocksize_bits) >= *elen)
-			*offset = 0;
-		else
-			epos->offset = lextoffset;
+	udf_readahead_dir(iter);
+	blk = udf_get_lb_pblock(iter->dir->i_sb, &iter->eloc, iter->loffset);
+	return sb_bread(iter->dir->i_sb, blk);
+}
 
-		brelse(fibh->sbh);
-		fibh->sbh = fibh->ebh = udf_tread(dir->i_sb, block);
-		if (!fibh->sbh)
-			return NULL;
-		fibh->soffset = fibh->eoffset = 0;
-
-		if (!(*offset & ((16 >> (blocksize_bits - 9)) - 1))) {
-			i = 16 >> (blocksize_bits - 9);
-			if (i + *offset > (*elen >> blocksize_bits))
-				i = (*elen >> blocksize_bits)-*offset;
-			for (num = 0; i > 0; i--) {
-				block = udf_get_lb_pblock(dir->i_sb, eloc,
-							  *offset + i);
-				tmp = udf_tgetblk(dir->i_sb, block);
-				if (tmp && !buffer_uptodate(tmp) &&
-						!buffer_locked(tmp))
-					bha[num++] = tmp;
-				else
-					brelse(tmp);
-			}
-			if (num) {
-				bh_readahead_batch(num, bha, REQ_RAHEAD);
-				for (i = 0; i < num; i++)
-					brelse(bha[i]);
-			}
+/*
+ * Updates loffset to point to next directory block; eloc, elen & epos are
+ * updated if we need to traverse to the next extent as well.
+ */
+static int udf_fiiter_advance_blk(struct udf_fileident_iter *iter)
+{
+	iter->loffset++;
+	if (iter->loffset < DIV_ROUND_UP(iter->elen, 1<<iter->dir->i_blkbits))
+		return 0;
+
+	iter->loffset = 0;
+	if (udf_next_aext(iter->dir, &iter->epos, &iter->eloc, &iter->elen, 1)
+			!= (EXT_RECORDED_ALLOCATED >> 30)) {
+		if (iter->pos == iter->dir->i_size) {
+			iter->elen = 0;
+			return 0;
 		}
-	} else if (fibh->sbh != fibh->ebh) {
-		brelse(fibh->sbh);
-		fibh->sbh = fibh->ebh;
+		udf_err(iter->dir->i_sb,
+			"extent after position %llu not allocated in directory (ino %lu)\n",
+			(unsigned long long)iter->pos, iter->dir->i_ino);
+		return -EFSCORRUPTED;
 	}
+	return 0;
+}
 
-	fi = udf_get_fileident(fibh->sbh->b_data, dir->i_sb->s_blocksize,
-			       &(fibh->eoffset));
-
-	if (!fi)
-		return NULL;
+static int udf_fiiter_load_bhs(struct udf_fileident_iter *iter)
+{
+	int blksize = 1 << iter->dir->i_blkbits;
+	int off = iter->pos & (blksize - 1);
+	int err;
+	struct fileIdentDesc *fi;
 
-	*nf_pos += fibh->eoffset - fibh->soffset;
+	/* Is there any further extent we can map from? */
+	if (!iter->bh[0] && iter->elen) {
+		iter->bh[0] = udf_fiiter_bread_blk(iter);
+		if (!iter->bh[0]) {
+			err = -ENOMEM;
+			goto out_brelse;
+		}
+		if (!buffer_uptodate(iter->bh[0])) {
+			err = -EIO;
+			goto out_brelse;
+		}
+	}
+	/* There's no next block so we are done */
+	if (iter->pos >= iter->dir->i_size)
+		return 0;
+	/* Need to fetch next block as well? */
+	if (off + sizeof(struct fileIdentDesc) > blksize)
+		goto fetch_next;
+	fi = (struct fileIdentDesc *)(iter->bh[0]->b_data + off);
+	/* Need to fetch next block to get name? */
+	if (off + udf_dir_entry_len(fi) > blksize) {
+fetch_next:
+		err = udf_fiiter_advance_blk(iter);
+		if (err)
+			goto out_brelse;
+		iter->bh[1] = udf_fiiter_bread_blk(iter);
+		if (!iter->bh[1]) {
+			err = -ENOMEM;
+			goto out_brelse;
+		}
+		if (!buffer_uptodate(iter->bh[1])) {
+			err = -EIO;
+			goto out_brelse;
+		}
+	}
+	return 0;
+out_brelse:
+	brelse(iter->bh[0]);
+	brelse(iter->bh[1]);
+	iter->bh[0] = iter->bh[1] = NULL;
+	return err;
+}
 
-	if (fibh->eoffset <= dir->i_sb->s_blocksize) {
-		memcpy((uint8_t *)cfi, (uint8_t *)fi,
-		       sizeof(struct fileIdentDesc));
-	} else if (fibh->eoffset > dir->i_sb->s_blocksize) {
-		uint32_t lextoffset = epos->offset;
+int udf_fiiter_init(struct udf_fileident_iter *iter, struct inode *dir,
+		    loff_t pos)
+{
+	struct udf_inode_info *iinfo = UDF_I(dir);
+	int err = 0;
+
+	iter->dir = dir;
+	iter->bh[0] = iter->bh[1] = NULL;
+	iter->pos = pos;
+	iter->elen = 0;
+	iter->epos.bh = NULL;
+	iter->name = NULL;
+	/*
+	 * When directory is verified, we don't expect directory iteration to
+	 * fail and it can be difficult to undo without corrupting filesystem.
+	 * So just do not allow memory allocation failures here.
+	 */
+	iter->namebuf = kmalloc(UDF_NAME_LEN_CS0, GFP_KERNEL | __GFP_NOFAIL);
 
-		if (udf_next_aext(dir, epos, eloc, elen, 1) !=
-		    (EXT_RECORDED_ALLOCATED >> 30))
-			return NULL;
+	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
+		err = udf_copy_fi(iter);
+		goto out;
+	}
 
-		block = udf_get_lb_pblock(dir->i_sb, eloc, *offset);
+	if (inode_bmap(dir, iter->pos >> dir->i_blkbits, &iter->epos,
+		       &iter->eloc, &iter->elen, &iter->loffset) !=
+	    (EXT_RECORDED_ALLOCATED >> 30)) {
+		if (pos == dir->i_size)
+			return 0;
+		udf_err(dir->i_sb,
+			"position %llu not allocated in directory (ino %lu)\n",
+			(unsigned long long)pos, dir->i_ino);
+		err = -EFSCORRUPTED;
+		goto out;
+	}
+	err = udf_fiiter_load_bhs(iter);
+	if (err < 0)
+		goto out;
+	err = udf_copy_fi(iter);
+out:
+	if (err < 0)
+		udf_fiiter_release(iter);
+	return err;
+}
 
-		(*offset)++;
+int udf_fiiter_advance(struct udf_fileident_iter *iter)
+{
+	unsigned int oldoff, len;
+	int blksize = 1 << iter->dir->i_blkbits;
+	int err;
+
+	oldoff = iter->pos & (blksize - 1);
+	len = udf_dir_entry_len(&iter->fi);
+	iter->pos += len;
+	if (UDF_I(iter->dir)->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
+		if (oldoff + len >= blksize) {
+			brelse(iter->bh[0]);
+			iter->bh[0] = NULL;
+			/* Next block already loaded? */
+			if (iter->bh[1]) {
+				iter->bh[0] = iter->bh[1];
+				iter->bh[1] = NULL;
+			} else {
+				err = udf_fiiter_advance_blk(iter);
+				if (err < 0)
+					return err;
+			}
+		}
+		err = udf_fiiter_load_bhs(iter);
+		if (err < 0)
+			return err;
+	}
+	return udf_copy_fi(iter);
+}
 
-		if ((*offset << dir->i_sb->s_blocksize_bits) >= *elen)
-			*offset = 0;
-		else
-			epos->offset = lextoffset;
+void udf_fiiter_release(struct udf_fileident_iter *iter)
+{
+	iter->dir = NULL;
+	brelse(iter->bh[0]);
+	brelse(iter->bh[1]);
+	iter->bh[0] = iter->bh[1] = NULL;
+	kfree(iter->namebuf);
+	iter->namebuf = NULL;
+}
 
-		fibh->soffset -= dir->i_sb->s_blocksize;
-		fibh->eoffset -= dir->i_sb->s_blocksize;
+static void udf_copy_to_bufs(void *buf1, int len1, void *buf2, int len2,
+			     int off, void *src, int len)
+{
+	int copy;
+
+	if (off >= len1) {
+		off -= len1;
+	} else {
+		copy = min(off + len, len1) - off;
+		memcpy(buf1 + off, src, copy);
+		src += copy;
+		len -= copy;
+		off = 0;
+	}
+	if (len > 0) {
+		if (WARN_ON_ONCE(off + len > len2 || !buf2))
+			return;
+		memcpy(buf2 + off, src, len);
+	}
+}
 
-		fibh->ebh = udf_tread(dir->i_sb, block);
-		if (!fibh->ebh)
-			return NULL;
+static uint16_t udf_crc_fi_bufs(void *buf1, int len1, void *buf2, int len2,
+				int off, int len)
+{
+	int copy;
+	uint16_t crc = 0;
+
+	if (off >= len1) {
+		off -= len1;
+	} else {
+		copy = min(off + len, len1) - off;
+		crc = crc_itu_t(crc, buf1 + off, copy);
+		len -= copy;
+		off = 0;
+	}
+	if (len > 0) {
+		if (WARN_ON_ONCE(off + len > len2 || !buf2))
+			return 0;
+		crc = crc_itu_t(crc, buf2 + off, len);
+	}
+	return crc;
+}
 
-		if (sizeof(struct fileIdentDesc) > -fibh->soffset) {
-			int fi_len;
+static void udf_copy_fi_to_bufs(char *buf1, int len1, char *buf2, int len2,
+				int off, struct fileIdentDesc *fi,
+				uint8_t *impuse, uint8_t *name)
+{
+	uint16_t crc;
+	int fioff = off;
+	int crcoff = off + sizeof(struct tag);
+	unsigned int crclen = udf_dir_entry_len(fi) - sizeof(struct tag);
+	char zeros[UDF_NAME_PAD] = {};
+	int endoff = off + udf_dir_entry_len(fi);
+
+	udf_copy_to_bufs(buf1, len1, buf2, len2, off, fi,
+			 sizeof(struct fileIdentDesc));
+	off += sizeof(struct fileIdentDesc);
+	if (impuse)
+		udf_copy_to_bufs(buf1, len1, buf2, len2, off, impuse,
+				 le16_to_cpu(fi->lengthOfImpUse));
+	off += le16_to_cpu(fi->lengthOfImpUse);
+	if (name) {
+		udf_copy_to_bufs(buf1, len1, buf2, len2, off, name,
+				 fi->lengthFileIdent);
+		off += fi->lengthFileIdent;
+		udf_copy_to_bufs(buf1, len1, buf2, len2, off, zeros,
+				 endoff - off);
+	}
 
-			memcpy((uint8_t *)cfi, (uint8_t *)fi, -fibh->soffset);
-			memcpy((uint8_t *)cfi - fibh->soffset,
-			       fibh->ebh->b_data,
-			       sizeof(struct fileIdentDesc) + fibh->soffset);
+	crc = udf_crc_fi_bufs(buf1, len1, buf2, len2, crcoff, crclen);
+	fi->descTag.descCRC = cpu_to_le16(crc);
+	fi->descTag.descCRCLength = cpu_to_le16(crclen);
+	fi->descTag.tagChecksum = udf_tag_checksum(&fi->descTag);
 
-			fi_len = udf_dir_entry_len(cfi);
-			*nf_pos += fi_len - (fibh->eoffset - fibh->soffset);
-			fibh->eoffset = fibh->soffset + fi_len;
-		} else {
-			memcpy((uint8_t *)cfi, (uint8_t *)fi,
-			       sizeof(struct fileIdentDesc));
-		}
-	}
-	/* Got last entry outside of dir size - fs is corrupted! */
-	if (*nf_pos > dir->i_size)
-		return NULL;
-	return fi;
+	udf_copy_to_bufs(buf1, len1, buf2, len2, fioff, fi, sizeof(struct tag));
 }
 
-struct fileIdentDesc *udf_get_fileident(void *buffer, int bufsize, int *offset)
+void udf_fiiter_write_fi(struct udf_fileident_iter *iter, uint8_t *impuse)
 {
-	struct fileIdentDesc *fi;
-	int lengthThisIdent;
-	uint8_t *ptr;
-	int padlen;
+	struct udf_inode_info *iinfo = UDF_I(iter->dir);
+	void *buf1, *buf2 = NULL;
+	int len1, len2 = 0, off;
+	int blksize = 1 << iter->dir->i_blkbits;
 
-	if ((!buffer) || (!offset)) {
-		udf_debug("invalidparms, buffer=%p, offset=%p\n",
-			  buffer, offset);
-		return NULL;
+	off = iter->pos & (blksize - 1);
+	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
+		buf1 = iinfo->i_data + iinfo->i_lenEAttr;
+		len1 = iter->dir->i_size;
+	} else {
+		buf1 = iter->bh[0]->b_data;
+		len1 = blksize;
+		if (iter->bh[1]) {
+			buf2 = iter->bh[1]->b_data;
+			len2 = blksize;
+		}
 	}
 
-	ptr = buffer;
+	udf_copy_fi_to_bufs(buf1, len1, buf2, len2, off, &iter->fi, impuse,
+			    iter->name == iter->namebuf ? iter->name : NULL);
 
-	if ((*offset > 0) && (*offset < bufsize))
-		ptr += *offset;
-	fi = (struct fileIdentDesc *)ptr;
-	if (fi->descTag.tagIdent != cpu_to_le16(TAG_IDENT_FID)) {
-		udf_debug("0x%x != TAG_IDENT_FID\n",
-			  le16_to_cpu(fi->descTag.tagIdent));
-		udf_debug("offset: %d sizeof: %lu bufsize: %d\n",
-			  *offset, (unsigned long)sizeof(struct fileIdentDesc),
-			  bufsize);
-		return NULL;
+	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
+		mark_inode_dirty(iter->dir);
+	} else {
+		mark_buffer_dirty_inode(iter->bh[0], iter->dir);
+		if (iter->bh[1])
+			mark_buffer_dirty_inode(iter->bh[1], iter->dir);
 	}
-	if ((*offset + sizeof(struct fileIdentDesc)) > bufsize)
-		lengthThisIdent = sizeof(struct fileIdentDesc);
-	else
-		lengthThisIdent = sizeof(struct fileIdentDesc) +
-			fi->lengthFileIdent + le16_to_cpu(fi->lengthOfImpUse);
+	inode_inc_iversion(iter->dir);
+}
 
-	/* we need to figure padding, too! */
-	padlen = lengthThisIdent % UDF_NAME_PAD;
-	if (padlen)
-		lengthThisIdent += (UDF_NAME_PAD - padlen);
-	*offset = *offset + lengthThisIdent;
+void udf_fiiter_update_elen(struct udf_fileident_iter *iter, uint32_t new_elen)
+{
+	struct udf_inode_info *iinfo = UDF_I(iter->dir);
+	int diff = new_elen - iter->elen;
+
+	/* Skip update when we already went past the last extent */
+	if (!iter->elen)
+		return;
+	iter->elen = new_elen;
+	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
+		iter->epos.offset -= sizeof(struct short_ad);
+	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
+		iter->epos.offset -= sizeof(struct long_ad);
+	udf_write_aext(iter->dir, &iter->epos, &iter->eloc, iter->elen, 1);
+	iinfo->i_lenExtents += diff;
+	mark_inode_dirty(iter->dir);
+}
 
-	return fi;
+/* Append new block to directory. @iter is expected to point at EOF */
+int udf_fiiter_append_blk(struct udf_fileident_iter *iter)
+{
+	struct udf_inode_info *iinfo = UDF_I(iter->dir);
+	int blksize = 1 << iter->dir->i_blkbits;
+	struct buffer_head *bh;
+	sector_t block;
+	uint32_t old_elen = iter->elen;
+	int err;
+
+	if (WARN_ON_ONCE(iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB))
+		return -EINVAL;
+
+	/* Round up last extent in the file */
+	udf_fiiter_update_elen(iter, ALIGN(iter->elen, blksize));
+
+	/* Allocate new block and refresh mapping information */
+	block = iinfo->i_lenExtents >> iter->dir->i_blkbits;
+	bh = udf_bread(iter->dir, block, 1, &err);
+	if (!bh) {
+		udf_fiiter_update_elen(iter, old_elen);
+		return err;
+	}
+	if (inode_bmap(iter->dir, block, &iter->epos, &iter->eloc, &iter->elen,
+		       &iter->loffset) != (EXT_RECORDED_ALLOCATED >> 30)) {
+		udf_err(iter->dir->i_sb,
+			"block %llu not allocated in directory (ino %lu)\n",
+			(unsigned long long)block, iter->dir->i_ino);
+		return -EFSCORRUPTED;
+	}
+	if (!(iter->pos & (blksize - 1))) {
+		brelse(iter->bh[0]);
+		iter->bh[0] = bh;
+	} else {
+		iter->bh[1] = bh;
+	}
+	return 0;
 }
 
 struct short_ad *udf_get_fileshortad(uint8_t *ptr, int maxoffset, uint32_t *offset,
diff --git a/fs/udf/file.c b/fs/udf/file.c
index 5c659e23e578..8238f742377b 100644
--- a/fs/udf/file.c
+++ b/fs/udf/file.c
@@ -38,100 +38,55 @@
 #include "udf_i.h"
 #include "udf_sb.h"
 
-static void __udf_adinicb_readpage(struct page *page)
+static vm_fault_t udf_page_mkwrite(struct vm_fault *vmf)
 {
-	struct inode *inode = page->mapping->host;
-	char *kaddr;
-	struct udf_inode_info *iinfo = UDF_I(inode);
-	loff_t isize = i_size_read(inode);
-
-	/*
-	 * We have to be careful here as truncate can change i_size under us.
-	 * So just sample it once and use the same value everywhere.
-	 */
-	kaddr = kmap_atomic(page);
-	memcpy(kaddr, iinfo->i_data + iinfo->i_lenEAttr, isize);
-	memset(kaddr + isize, 0, PAGE_SIZE - isize);
-	flush_dcache_page(page);
-	SetPageUptodate(page);
-	kunmap_atomic(kaddr);
-}
-
-static int udf_adinicb_read_folio(struct file *file, struct folio *folio)
-{
-	BUG_ON(!folio_test_locked(folio));
-	__udf_adinicb_readpage(&folio->page);
-	folio_unlock(folio);
-
-	return 0;
-}
-
-static int udf_adinicb_writepage(struct page *page,
-				 struct writeback_control *wbc)
-{
-	struct inode *inode = page->mapping->host;
-	char *kaddr;
-	struct udf_inode_info *iinfo = UDF_I(inode);
-
-	BUG_ON(!PageLocked(page));
-
-	kaddr = kmap_atomic(page);
-	memcpy(iinfo->i_data + iinfo->i_lenEAttr, kaddr, i_size_read(inode));
-	SetPageUptodate(page);
-	kunmap_atomic(kaddr);
-	mark_inode_dirty(inode);
-	unlock_page(page);
-
-	return 0;
-}
-
-static int udf_adinicb_write_begin(struct file *file,
-			struct address_space *mapping, loff_t pos,
-			unsigned len, struct page **pagep,
-			void **fsdata)
-{
-	struct page *page;
-
-	if (WARN_ON_ONCE(pos >= PAGE_SIZE))
-		return -EIO;
-	page = grab_cache_page_write_begin(mapping, 0);
-	if (!page)
-		return -ENOMEM;
-	*pagep = page;
-
-	if (!PageUptodate(page))
-		__udf_adinicb_readpage(page);
-	return 0;
-}
-