[PATCH 5.10 02/18] udf: Fix preallocation discarding at indirect extent boundary

Greg Kroah-Hartman
2022-12-19T19:27:51Z

From: Jan Kara <jack@suse.cz>

commit cfe4c1b25dd6d2f056afc00b7c98bcb3dd0b1fc3 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/udf/truncate.c | 45 +++++++++++++--------------------------------
1 file changed, 13 insertions(+), 32 deletions(-)

--- a/fs/udf/truncate.c
+++ b/fs/udf/truncate.c
@@ -120,60 +120,41 @@ void udf_truncate_tail_extent(struct ino

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,