Filipe Manana 於 2019-03-25 19:14 寫到:
On Mon, Jan 14, 2019 at 3:26 AM robbieko <robbieko@xxxxxxxxxxxx> wrote:
From: Robbie Ko <robbieko@xxxxxxxxxxxx>
When doing fallocate, we first add the range to the reserve_list
and then reserve the qutoa.
qutoa -> quota
If quota reservation fails, we'll release all reserved parts of
reserve_list.
However, cur_offset doen't update to indicate that this range is
"doen't update" -> is not updated to indicate ...
already been inserted into the list.
Therefore, the same range is freed twice.
One at list_for_each_entry loop, and the other at the end of the
One -> once
and the other at -> and once at
function.
This will result in WARN_ON on bytes_may_use when we free the
remaining space.
Fixes: ("btrfs: update btrfs_space_info's bytes_may_use timely")
Missing commit id.
Signed-off-by: Robbie Ko <robbieko@xxxxxxxxxxxx>
---
fs/btrfs/file.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index d38dc8c..43c6c8a 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -3132,6 +3132,7 @@ static long btrfs_fallocate(struct file *file,
int mode,
ret = btrfs_qgroup_reserve_data(inode,
&data_reserved,
cur_offset, last_byte -
cur_offset);
if (ret < 0) {
+ cur_offset = last_byte;
This will fix the problem if there's only one range, or we happen to
be very lucky and cur_offset
matches exactly the middle of the entire range passed to fallocate()
(in case the range covers
a sparse region of the file, a region with holes and extents).
At the end, under the 'out' label we have a call to:
btrfs_free_reserved_data_space(inode, data_reserved, alloc_start,
alloc_end - cur_offset);
That doesn't fell right - the start offset, third argument, should be
cur_offset. Everything from
alloc_start to cur_offset was freed by the
list_for_each_entry_safe_loop.
Ok, I will send patch v2.
Thank you.
free_extent_map(em);
break;
}
--
1.9.1
