[PATCH 8/9] ext4: only initialize mmp_bdevname once

Christoph Hellwig
2022-07-13T05:54:32Z

mmp_bdevname is currently both initialized nested inside the kthread_run
call in ext4_multi_mount_protect and in the kmmpd thread started by it.

Lift the initiaization out of the kthread_run call in
ext4_multi_mount_protect, move the BUILD_BUG_ON next to it and remove
the duplicate assignment inside of kmmpd.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/ext4/mmp.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c
index 79d05e464c432..b7a850b0070b8 100644
--- a/fs/ext4/mmp.c
+++ b/fs/ext4/mmp.c
@@ -150,8 +150,6 @@ static int kmmpd(void *data)
mmp_check_interval = max(EXT4_MMP_CHECK_MULT * mmp_update_interval,
EXT4_MMP_MIN_CHECK_INTERVAL);
mmp->mmp_check_interval = cpu_to_le16(mmp_check_interval);
- BUILD_BUG_ON(sizeof(mmp->mmp_bdevname) < BDEVNAME_SIZE);
- bdevname(bh->b_bdev, mmp->mmp_bdevname);

memcpy(mmp->mmp_nodename, init_utsname()->nodename,
sizeof(mmp->mmp_nodename));
@@ -372,13 +370,15 @@ int ext4_multi_mount_protect(struct super_block *sb,

EXT4_SB(sb)->s_mmp_bh = bh;

+ BUILD_BUG_ON(sizeof(mmp->mmp_bdevname) < BDEVNAME_SIZE);
+ bdevname(bh->b_bdev, mmp->mmp_bdevname);
+
/*
* Start a kernel thread to update the MMP block periodically.
*/
EXT4_SB(sb)->s_mmp_tsk = kthread_run(kmmpd, sb, "kmmpd-%.*s",
(int)sizeof(mmp->mmp_bdevname),
- bdevname(bh->b_bdev,
- mmp->mmp_bdevname));
+ mmp->mmp_bdevname);
if (IS_ERR(EXT4_SB(sb)->s_mmp_tsk)) {
EXT4_SB(sb)->s_mmp_tsk = NULL;
ext4_warning(sb, "Unable to create kmmpd thread for %s.",
--
2.30.2