2021-06-07 17:59:10

by Leah Rumancik

Subject: [PATCH] ext4: fix input checking in fs/jbd2/journal.c

Update

if (JBD2_JOURNAL_FLUSH_DISCARD & !blk_queue_discard(q))

to use && instead of &. JBD2_JOURNAL_FLUSH_DISCARD is set to 1 so &
technically works but && could be a bit faster and will maintain
correctness in the event the value of JBD2_JOURNAL_FLUSH_DISCARD is
updated.

Reported-by: kernel test robot <[email protected]>
Reported-by: Dan Carpenter <[email protected]>

Signed-off-by: Leah Rumancik <[email protected]>
---
fs/jbd2/journal.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 521ce41c242c..f0636180b624 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1715,7 +1715,7 @@ static int __jbd2_journal_erase(journal_t *journal, unsigned int flags)
if (!q)
return -ENXIO;

- if (JBD2_JOURNAL_FLUSH_DISCARD & !blk_queue_discard(q))
+ if (JBD2_JOURNAL_FLUSH_DISCARD && !blk_queue_discard(q))
return -EOPNOTSUPP;

/*
--
2.32.0.rc1.229.g3e70b5a671-goog

2021-06-24 14:17:43

by Theodore Ts'o

Subject: Re: [PATCH] ext4: fix input checking in fs/jbd2/journal.c

On Mon, Jun 07, 2021 at 05:55:58PM +0000, Leah Rumancik wrote:
> Update
>
> if (JBD2_JOURNAL_FLUSH_DISCARD & !blk_queue_discard(q))
>
> to use && instead of &. JBD2_JOURNAL_FLUSH_DISCARD is set to 1 so &
> technically works but && could be a bit faster and will maintain
> correctness in the event the value of JBD2_JOURNAL_FLUSH_DISCARD is
> updated.
>
> Reported-by: kernel test robot <[email protected]>
> Reported-by: Dan Carpenter <[email protected]>
>
> Signed-off-by: Leah Rumancik <[email protected]>

Thanks, I've folded this fix into the base commit.

- Ted