Re: [PATCH v3 4/5] xfs: check tp->t_dqinfo value instead of the XFS_TRANS_DQ_DIRTY flag

[kaixuxia <xiakaixu1987@gmail.com>]

On 2020/10/8 6:04, Darrick J. Wong wrote:
> On Wed, Oct 07, 2020 at 10:51:11PM +0800, xiakaixu1987@gmail.com wrote:
>> From: Kaixu Xia <kaixuxia@tencent.com>
>>
>> Nowadays the only things that the XFS_TRANS_DQ_DIRTY flag seems to do
>> are indicates the tp->t_dqinfo->dqs[XFS_QM_TRANS_{USR,GRP,PRJ}] values
>> changed and check in xfs_trans_apply_dquot_deltas() and the unreserve
>> variant xfs_trans_unreserve_and_mod_dquots(). Actually, we also can
>> use the tp->t_dqinfo value instead of the XFS_TRANS_DQ_DIRTY flag, that
>> is to say, we allocate the new tp->t_dqinfo only when the qtrx values
>> changed, so the tp->t_dqinfo value isn't NULL equals the XFS_TRANS_DQ_DIRTY
>> flag is set, we only need to check if tp->t_dqinfo == NULL in
>> xfs_trans_apply_dquot_deltas() and its unreserve variant to determine
>> whether lock all of the dquots and join them to the transaction.
>>
>> Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
>> ---
>>  fs/xfs/libxfs/xfs_shared.h |  1 -
>>  fs/xfs/xfs_inode.c         |  8 +-------
>>  fs/xfs/xfs_trans_dquot.c   | 17 ++---------------
>>  3 files changed, 3 insertions(+), 23 deletions(-)
>>
>> diff --git a/fs/xfs/libxfs/xfs_shared.h b/fs/xfs/libxfs/xfs_shared.h
>> index c795ae47b3c9..8c61a461bf7b 100644
>> --- a/fs/xfs/libxfs/xfs_shared.h
>> +++ b/fs/xfs/libxfs/xfs_shared.h
>> @@ -62,7 +62,6 @@ void	xfs_log_get_max_trans_res(struct xfs_mount *mp,
>>  #define	XFS_TRANS_SB_DIRTY	0x02	/* superblock is modified */
>>  #define	XFS_TRANS_PERM_LOG_RES	0x04	/* xact took a permanent log res */
>>  #define	XFS_TRANS_SYNC		0x08	/* make commit synchronous */
>> -#define XFS_TRANS_DQ_DIRTY	0x10	/* at least one dquot in trx dirty */
>>  #define XFS_TRANS_RESERVE	0x20    /* OK to use reserved data blocks */
>>  #define XFS_TRANS_NO_WRITECOUNT 0x40	/* do not elevate SB writecount */
>>  #define XFS_TRANS_RES_FDBLKS	0x80	/* reserve newly freed blocks */
>> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
>> index 49624973eecc..9108eed0ea45 100644
>> --- a/fs/xfs/xfs_inode.c
>> +++ b/fs/xfs/xfs_inode.c
>> @@ -941,7 +941,6 @@ xfs_dir_ialloc(
>>  	xfs_buf_t	*ialloc_context = NULL;
>>  	int		code;
>>  	void		*dqinfo;
>> -	uint		tflags;
>>  
>>  	tp = *tpp;
>>  	ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
>> @@ -1000,12 +999,9 @@ xfs_dir_ialloc(
>>  		 * and attach it to the next transaction.
>>  		 */
>>  		dqinfo = NULL;
>> -		tflags = 0;
>>  		if (tp->t_dqinfo) {
>>  			dqinfo = (void *)tp->t_dqinfo;
>>  			tp->t_dqinfo = NULL;
>> -			tflags = tp->t_flags & XFS_TRANS_DQ_DIRTY;
>> -			tp->t_flags &= ~(XFS_TRANS_DQ_DIRTY);
>>  		}
>>  
>>  		code = xfs_trans_roll(&tp);
>> @@ -1013,10 +1009,8 @@ xfs_dir_ialloc(
>>  		/*
>>  		 * Re-attach the quota info that we detached from prev trx.
>>  		 */
>> -		if (dqinfo) {
>> +		if (dqinfo)
>>  			tp->t_dqinfo = dqinfo;
>> -			tp->t_flags |= tflags;
>> -		}
>>  
>>  		if (code) {
>>  			xfs_buf_relse(ialloc_context);
>> diff --git a/fs/xfs/xfs_trans_dquot.c b/fs/xfs/xfs_trans_dquot.c
>> index 1b56065c9ff1..0ebfd7930382 100644
>> --- a/fs/xfs/xfs_trans_dquot.c
>> +++ b/fs/xfs/xfs_trans_dquot.c
>> @@ -84,13 +84,6 @@ xfs_trans_dup_dqinfo(
>>  
>>  	xfs_trans_alloc_dqinfo(ntp);
>>  
>> -	/*
>> -	 * Because the quota blk reservation is carried forward,
>> -	 * it is also necessary to carry forward the DQ_DIRTY flag.
>> -	 */
>> -	if (otp->t_flags & XFS_TRANS_DQ_DIRTY)
>> -		ntp->t_flags |= XFS_TRANS_DQ_DIRTY;
>> -
>>  	for (j = 0; j < XFS_QM_TRANS_DQTYPES; j++) {
>>  		oqa = otp->t_dqinfo->dqs[j];
>>  		nqa = ntp->t_dqinfo->dqs[j];
>> @@ -270,8 +263,6 @@ xfs_trans_mod_dquot(
>>  
>>  	if (delta)
>>  		trace_xfs_trans_mod_dquot_after(qtrx);
>> -
>> -	tp->t_flags |= XFS_TRANS_DQ_DIRTY;
>>  }
>>  
>>  
>> @@ -348,7 +339,7 @@ xfs_trans_apply_dquot_deltas(
>>  	int64_t			totalbdelta;
>>  	int64_t			totalrtbdelta;
>>  
>> -	if (!(tp->t_flags & XFS_TRANS_DQ_DIRTY))
>> +	if (!tp->t_dqinfo)
>>  		return;
>>  
>>  	ASSERT(tp->t_dqinfo);
>> @@ -490,7 +481,7 @@ xfs_trans_unreserve_and_mod_dquots(
>>  	struct xfs_dqtrx	*qtrx, *qa;
>>  	bool			locked;
>>  
>> -	if (!tp->t_dqinfo || !(tp->t_flags & XFS_TRANS_DQ_DIRTY))
>> +	if (!tp->t_dqinfo)
>>  		return;
>>  
>>  	for (j = 0; j < XFS_QM_TRANS_DQTYPES; j++) {
>> @@ -695,7 +686,6 @@ xfs_trans_dqresv(
>>  	 * because we don't have the luxury of a transaction envelope then.
>>  	 */
>>  	if (tp) {
>> -		ASSERT(tp->t_dqinfo);
>>  		ASSERT(flags & XFS_QMOPT_RESBLK_MASK);
>>  		if (nblks != 0)
>>  			xfs_trans_mod_dquot(tp, dqp,
>> @@ -749,9 +739,6 @@ xfs_trans_reserve_quota_bydquots(
>>  	if (!XFS_IS_QUOTA_RUNNING(mp) || !XFS_IS_QUOTA_ON(mp))
>>  		return 0;
>>  
>> -	if (tp && tp->t_dqinfo == NULL)
>> -		xfs_trans_alloc_dqinfo(tp);
>> -
> 
> This also should be a separate patch (or I guess the previous one?)
> in which the commit log points out that the allocation is already
> covered by the chain xfs_trans_reserve_quota_bydquots ->
> xfs_trans_dqresv -> xfs_trans_mod_dquot.

Yeah, make more sense, I'll follow it in the next version.

Thanks,
Kaixu
> 
> --D
> 
>>  	ASSERT(flags & XFS_QMOPT_RESBLK_MASK);
>>  
>>  	if (udqp) {
>> -- 
>> 2.20.0
>>

-- 
kaixuxia