Commit c5b045b9 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

ext4: only initialize mmp_bdevname once 



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: default avatarChristoph Hellwig <hch@lst.de>
Acked-by: default avatarTheodore Ts'o <tytso@mit.edu>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220713055317.1888500-9-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 4664954c

fs/ext4/mmp.c

+4 −4
Original line number Diff line number Diff line
@@ -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.",