When we append new block just after the end of preallocated extent, the
code in inode_getblk() wrongly determined we're going to use the
preallocated extent which resulted in adding block into a wrong logical
offset in the file. Sequence like this manifests it:
xfs_io -f -c "pwrite 0x2cacf 0xd122" -c "truncate 0x2dd6f" \
-c "pwrite 0x27fd9 0x69a9" -c "pwrite 0x32981 0x7244" <file>
The code that determined the use of preallocated extent is actually
stale because udf_do_extend_file() does not create preallocation anymore
so after calling that function we are sure there's no usable
preallocation. Just remove the faulty condition.
CC: stable@xxxxxxxxxxxxxxx
Fixes: 16d055656814 ("udf: Discard preallocation before extending file with a hole")
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
fs/udf/inode.c | 24 +++++++++++-------------
1 file changed, 11 insertions(+), 13 deletions(-)
diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index 8f55b37ddcad..6826c2aa021f 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -742,19 +742,17 @@ static int inode_getblk(struct inode *inode, struct udf_map_rq *map)
c = 0;
offset = 0;
count += ret;
- /* We are not covered by a preallocated extent? */
- if ((laarr[0].extLength & UDF_EXTENT_FLAG_MASK) !=
- EXT_NOT_RECORDED_ALLOCATED) {
- /* Is there any real extent? - otherwise we overwrite
- * the fake one... */
- if (count)
- c = !c;
- laarr[c].extLength = EXT_NOT_RECORDED_NOT_ALLOCATED |
- inode->i_sb->s_blocksize;
- memset(&laarr[c].extLocation, 0x00,
- sizeof(struct kernel_lb_addr));
- count++;
- }
+ /*
+ * Is there any real extent? - otherwise we overwrite the fake
+ * one...
+ */
+ if (count)
+ c = !c;
+ laarr[c].extLength = EXT_NOT_RECORDED_NOT_ALLOCATED |
+ inode->i_sb->s_blocksize;
+ memset(&laarr[c].extLocation, 0x00,
+ sizeof(struct kernel_lb_addr));
+ count++;
endnum = c + 1;
lastblock = 1;
} else {
--
2.35.3
