[PATCH 1/4] udf: Fix preallocation discarding at indirect extent boundary

[PATCH 1/4] udf: Fix preallocation discarding at indirect extent boundary

[Jan Kara]

When preallocation extent is the first one in the extent block, the
code would corrupt extent tree header instead. Fix the problem and use
udf_delete_aext() for deleting extent to avoid some code duplication.

CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/udf/truncate.c | 45 +++++++++++++--------------------------------
 1 file changed, 13 insertions(+), 32 deletions(-)

diff --git a/fs/udf/truncate.c b/fs/udf/truncate.c
index 532cda99644e..a9790fb32f5f 100644
--- a/fs/udf/truncate.c
+++ b/fs/udf/truncate.c
@@ -120,60 +120,41 @@ void udf_truncate_tail_extent(struct inode *inode)
 
 void udf_discard_prealloc(struct inode *inode)
 {
-	struct extent_position epos = { NULL, 0, {0, 0} };
+	struct extent_position epos = {};
+	struct extent_position prev_epos = {};
 	struct kernel_lb_addr eloc;
 	uint32_t elen;
 	uint64_t lbcount = 0;
 	int8_t etype = -1, netype;
-	int adsize;
 	struct udf_inode_info *iinfo = UDF_I(inode);
 
 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB ||
 	    inode->i_size == iinfo->i_lenExtents)
 		return;
 
-	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
-		adsize = sizeof(struct short_ad);
-	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
-		adsize = sizeof(struct long_ad);
-	else
-		adsize = 0;
-
 	epos.block = iinfo->i_location;
 
 	/* Find the last extent in the file */
-	while ((netype = udf_next_aext(inode, &epos, &eloc, &elen, 1)) != -1) {
-		etype = netype;
+	while ((netype = udf_next_aext(inode, &epos, &eloc, &elen, 0)) != -1) {
+		brelse(prev_epos.bh);
+		prev_epos = epos;
+		if (prev_epos.bh)
+			get_bh(prev_epos.bh);
+
+		etype = udf_next_aext(inode, &epos, &eloc, &elen, 1);
 		lbcount += elen;
 	}
 	if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
-		epos.offset -= adsize;
 		lbcount -= elen;
-		extent_trunc(inode, &epos, &eloc, etype, elen, 0);
-		if (!epos.bh) {
-			iinfo->i_lenAlloc =
-				epos.offset -
-				udf_file_entry_alloc_offset(inode);
-			mark_inode_dirty(inode);
-		} else {
-			struct allocExtDesc *aed =
-				(struct allocExtDesc *)(epos.bh->b_data);
-			aed->lengthAllocDescs =
-				cpu_to_le32(epos.offset -
-					    sizeof(struct allocExtDesc));
-			if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) ||
-			    UDF_SB(inode->i_sb)->s_udfrev >= 0x0201)
-				udf_update_tag(epos.bh->b_data, epos.offset);
-			else
-				udf_update_tag(epos.bh->b_data,
-					       sizeof(struct allocExtDesc));
-			mark_buffer_dirty_inode(epos.bh, inode);
-		}
+		udf_delete_aext(inode, prev_epos);
+		udf_free_blocks(inode->i_sb, inode, &eloc, 0,
+				DIV_ROUND_UP(elen, 1 << inode->i_blkbits));
 	}
 	/* This inode entry is in-memory only and thus we don't have to mark
 	 * the inode dirty */
 	iinfo->i_lenExtents = lbcount;
 	brelse(epos.bh);
+	brelse(prev_epos.bh);
 }
 
 static void udf_update_alloc_ext_desc(struct inode *inode,
-- 
2.35.3

[PATCH 2/4] udf: Do not bother looking for prealloc extents if i_lenExtents matches i_size

[Jan Kara]

If rounded block-rounded i_lenExtents matches block rounded i_size,
there are no preallocation extents. Do not bother walking extent linked
list.

CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/udf/truncate.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/udf/truncate.c b/fs/udf/truncate.c
index a9790fb32f5f..036ebd892b85 100644
--- a/fs/udf/truncate.c
+++ b/fs/udf/truncate.c
@@ -127,9 +127,10 @@ void udf_discard_prealloc(struct inode *inode)
 	uint64_t lbcount = 0;
 	int8_t etype = -1, netype;
 	struct udf_inode_info *iinfo = UDF_I(inode);
+	int bsize = 1 << inode->i_blkbits;
 
 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB ||
-	    inode->i_size == iinfo->i_lenExtents)
+	    ALIGN(inode->i_size, bsize) == ALIGN(iinfo->i_lenExtents, bsize))
 		return;
 
 	epos.block = iinfo->i_location;
-- 
2.35.3

[PATCH 3/4] udf: Discard preallocation before extending file with a hole

[Jan Kara]

When extending file with a hole, we tried to preserve existing
preallocation for the file. However that is not very useful and
complicates code because the previous extent may need to be rounded to
block boundary as well (which we forgot to do thus causing data
corruption for sequence like:

xfs_io -f -c "pwrite 0x75e63 11008" -c "truncate 0x7b24b" \
  -c "truncate 0xabaa3" -c "pwrite 0xac70b 22954" \
  -c "pwrite 0x93a43 11358" -c "pwrite 0xb8e65 52211" file

with 512-byte block size. Just discard preallocation before extending
file to simplify things and also fix this data corruption.

CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/udf/inode.c | 46 ++++++++++++++++++----------------------------
 1 file changed, 18 insertions(+), 28 deletions(-)

diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index 6db2ef047f1c..d09ca6db14a0 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -349,6 +349,12 @@ static int udf_get_block(struct inode *inode, sector_t block,
 		iinfo->i_next_alloc_goal++;
 	}
 
+	/*
+	 * Block beyond EOF and prealloc extents? Just discard preallocation
+	 * as it is not useful and complicates things.
+	 */
+	if (((loff_t)block) << inode->i_blkbits > iinfo->i_lenExtents)
+		udf_discard_prealloc(inode);
 	udf_clear_extent_cache(inode);
 	phys = inode_getblk(inode, block, &err, &new);
 	if (!phys)
@@ -398,8 +404,6 @@ static int udf_do_extend_file(struct inode *inode,
 	uint32_t add;
 	int count = 0, fake = !(last_ext->extLength & UDF_EXTENT_LENGTH_MASK);
 	struct super_block *sb = inode->i_sb;
-	struct kernel_lb_addr prealloc_loc = {};
-	uint32_t prealloc_len = 0;
 	struct udf_inode_info *iinfo;
 	int err;
 
@@ -420,19 +424,6 @@ static int udf_do_extend_file(struct inode *inode,
 			~(sb->s_blocksize - 1);
 	}
 
-	/* Last extent are just preallocated blocks? */
-	if ((last_ext->extLength & UDF_EXTENT_FLAG_MASK) ==
-						EXT_NOT_RECORDED_ALLOCATED) {
-		/* Save the extent so that we can reattach it to the end */
-		prealloc_loc = last_ext->extLocation;
-		prealloc_len = last_ext->extLength;
-		/* Mark the extent as a hole */
-		last_ext->extLength = EXT_NOT_RECORDED_NOT_ALLOCATED |
-			(last_ext->extLength & UDF_EXTENT_LENGTH_MASK);
-		last_ext->extLocation.logicalBlockNum = 0;
-		last_ext->extLocation.partitionReferenceNum = 0;
-	}
-
 	/* Can we merge with the previous extent? */
 	if ((last_ext->extLength & UDF_EXTENT_FLAG_MASK) ==
 					EXT_NOT_RECORDED_NOT_ALLOCATED) {
@@ -460,7 +451,7 @@ static int udf_do_extend_file(struct inode *inode,
 		 * more extents, we may need to enter possible following
 		 * empty indirect extent.
 		 */
-		if (new_block_bytes || prealloc_len)
+		if (new_block_bytes)
 			udf_next_aext(inode, last_pos, &tmploc, &tmplen, 0);
 	}
 
@@ -494,17 +485,6 @@ static int udf_do_extend_file(struct inode *inode,
 	}
 
 out:
-	/* Do we have some preallocated blocks saved? */
-	if (prealloc_len) {
-		err = udf_add_aext(inode, last_pos, &prealloc_loc,
-				   prealloc_len, 1);
-		if (err)
-			return err;
-		last_ext->extLocation = prealloc_loc;
-		last_ext->extLength = prealloc_len;
-		count++;
-	}
-
 	/* last_pos should point to the last written extent... */
 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 		last_pos->offset -= sizeof(struct short_ad);
@@ -557,8 +537,17 @@ static int udf_extend_file(struct inode *inode, loff_t newsize)
 	else
 		BUG();
 
+	/*
+	 * When creating hole in file, just don't bother with preserving
+	 * preallocation. It likely won't be very useful anyway.
+	 */
+	udf_discard_prealloc(inode);
+
 	etype = inode_bmap(inode, first_block, &epos, &eloc, &elen, &offset);
 	within_final_block = (etype != -1);
+	/* We don't expect extents past EOF... */
+	WARN_ON_ONCE(etype != -1 &&
+		     elen > ((loff_t)offset + 1) << inode->i_blkbits);
 
 	if ((!epos.bh && epos.offset == udf_file_entry_alloc_offset(inode)) ||
 	    (epos.bh && epos.offset == sizeof(struct allocExtDesc))) {
@@ -687,10 +676,11 @@ static sector_t inode_getblk(struct inode *inode, sector_t block,
 		goto out_free;
 	}
 
-	/* Are we beyond EOF? */
+	/* Are we beyond EOF and preallocated extent? */
 	if (etype == -1) {
 		int ret;
 		loff_t hole_len;
+
 		isBeyondEOF = true;
 		if (count) {
 			if (c)
-- 
2.35.3

[PATCH 4/4] udf: Fix extending file within last block

[Jan Kara]

When extending file within last block it can happen that the extent is
already rounded to the blocksize and thus contains the offset we want to
grow up to. In such case we would mistakenly expand the last extent and
make it one block longer than it should be, exposing unallocated block
in a file and causing data corruption. Fix the problem by properly
detecting this case and bailing out.

CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/udf/inode.c | 32 +++++++++++++++++---------------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index d09ca6db14a0..1e5d37f6c689 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -500,13 +500,17 @@ static int udf_do_extend_file(struct inode *inode,
 static void udf_do_extend_final_block(struct inode *inode,
 				      struct extent_position *last_pos,
 				      struct kernel_long_ad *last_ext,
-				      uint32_t final_block_len)
+				      uint32_t new_elen)
 {
-	struct super_block *sb = inode->i_sb;
 	uint32_t added_bytes;
 
-	added_bytes = final_block_len -
-		      (last_ext->extLength & (sb->s_blocksize - 1));
+	/*
+	 * Extent already large enough? It may be already rounded up to block
+	 * size...
+	 */
+	if (new_elen <= (last_ext->extLength & UDF_EXTENT_LENGTH_MASK))
+		return;
+	added_bytes = (last_ext->extLength & UDF_EXTENT_LENGTH_MASK) - new_elen;
 	last_ext->extLength += added_bytes;
 	UDF_I(inode)->i_lenExtents += added_bytes;
 
@@ -523,12 +527,12 @@ static int udf_extend_file(struct inode *inode, loff_t newsize)
 	int8_t etype;
 	struct super_block *sb = inode->i_sb;
 	sector_t first_block = newsize >> sb->s_blocksize_bits, offset;
-	unsigned long partial_final_block;
+	loff_t new_elen;
 	int adsize;
 	struct udf_inode_info *iinfo = UDF_I(inode);
 	struct kernel_long_ad extent;
 	int err = 0;
-	int within_final_block;
+	bool within_last_ext;
 
 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 		adsize = sizeof(struct short_ad);
@@ -544,9 +548,9 @@ static int udf_extend_file(struct inode *inode, loff_t newsize)
 	udf_discard_prealloc(inode);
 
 	etype = inode_bmap(inode, first_block, &epos, &eloc, &elen, &offset);
-	within_final_block = (etype != -1);
+	within_last_ext = (etype != -1);
 	/* We don't expect extents past EOF... */
-	WARN_ON_ONCE(etype != -1 &&
+	WARN_ON_ONCE(within_last_ext &&
 		     elen > ((loff_t)offset + 1) << inode->i_blkbits);
 
 	if ((!epos.bh && epos.offset == udf_file_entry_alloc_offset(inode)) ||
@@ -563,19 +567,17 @@ static int udf_extend_file(struct inode *inode, loff_t newsize)
 		extent.extLength |= etype << 30;
 	}
 
-	partial_final_block = newsize & (sb->s_blocksize - 1);
+	new_elen = ((loff_t)offset << inode->i_blkbits) |
+					(newsize & (sb->s_blocksize - 1));
 
 	/* File has extent covering the new size (could happen when extending
 	 * inside a block)?
 	 */
-	if (within_final_block) {
+	if (within_last_ext) {
 		/* Extending file within the last file block */
-		udf_do_extend_final_block(inode, &epos, &extent,
-					  partial_final_block);
+		udf_do_extend_final_block(inode, &epos, &extent, new_elen);
 	} else {
-		loff_t add = ((loff_t)offset << sb->s_blocksize_bits) |
-			     partial_final_block;
-		err = udf_do_extend_file(inode, &epos, &extent, add);
+		err = udf_do_extend_file(inode, &epos, &extent, new_elen);
 	}
 
 	if (err < 0)
-- 
2.35.3