Re: [Ocfs2-devel] [PATCH 19/56] mm: Export pdflush_operation()

[Jan Kara <jack@suse.cz>]

On Wed 31-12-08 15:09:49, Mark Fasheh wrote:
> From: Mark Fasheh <mfasheh@suse.com>
> 
> ocfs2/quota: Use workqueue for periodic syncing instead of pdflush()
> 
> Using pdflush_operation() for this was potentially buggy - we could get into
> a situation where the work function never gets run. Instead, just create a
> workqueue, 'o2quota' and just constantly queue a delayed work item. The
> impact of this should be pretty minimal.
> 
> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
  The patch looks fine. You can add 'Acked-by: Jan Kara <jack@suse.cz>'

										Honza
> ---
>  fs/ocfs2/quota.h        |    5 +++-
>  fs/ocfs2/quota_global.c |   48 ++++++++++++++++++++++++++++++----------------
>  fs/ocfs2/quota_local.c  |    2 +-
>  fs/ocfs2/super.c        |    7 ++++++
>  4 files changed, 43 insertions(+), 19 deletions(-)
> 
> diff --git a/fs/ocfs2/quota.h b/fs/ocfs2/quota.h
> index abf6941..6d190c0 100644
> --- a/fs/ocfs2/quota.h
> +++ b/fs/ocfs2/quota.h
> @@ -60,7 +60,7 @@ struct ocfs2_mem_dqinfo {
>  	struct buffer_head *dqi_lqi_bh;	/* Buffer head with local quota file inode */
>  	struct buffer_head *dqi_ibh;	/* Buffer with information header */
>  	struct qtree_mem_dqinfo dqi_gi;	/* Info about global file */
> -	struct timer_list dqi_sync_timer;	/* Timer for syncing dquots */
> +	struct delayed_work dqi_sync_work;	/* Work for syncing dquots */
>  	struct ocfs2_quota_recovery *dqi_rec;	/* Pointer to recovery
>  						 * information, in case we
>  						 * enable quotas on file
> @@ -114,4 +114,7 @@ int ocfs2_read_quota_block(struct inode *inode, u64 v_block,
>  extern struct dquot_operations ocfs2_quota_operations;
>  extern struct quota_format_type ocfs2_quota_format;
>  
> +int ocfs2_quota_setup(void);
> +void ocfs2_quota_shutdown(void);
> +
>  #endif /* _OCFS2_QUOTA_H */
> diff --git a/fs/ocfs2/quota_global.c b/fs/ocfs2/quota_global.c
> index 9184953..6aff8f2 100644
> --- a/fs/ocfs2/quota_global.c
> +++ b/fs/ocfs2/quota_global.c
> @@ -7,8 +7,8 @@
>  #include <linux/quotaops.h>
>  #include <linux/dqblk_qtree.h>
>  #include <linux/jiffies.h>
> -#include <linux/timer.h>
>  #include <linux/writeback.h>
> +#include <linux/workqueue.h>
>  
>  #define MLOG_MASK_PREFIX ML_QUOTA
>  #include <cluster/masklog.h>
> @@ -25,7 +25,9 @@
>  #include "uptodate.h"
>  #include "quota.h"
>  
> -static void qsync_timer_fn(unsigned long oinfo_ptr);
> +static struct workqueue_struct *ocfs2_quota_wq = NULL;
> +
> +static void qsync_work_fn(struct work_struct *work);
>  
>  static void ocfs2_global_disk2memdqb(struct dquot *dquot, void *dp)
>  {
> @@ -348,10 +350,10 @@ int ocfs2_global_read_info(struct super_block *sb, int type)
>  	oinfo->dqi_gi.dqi_usable_bs = sb->s_blocksize -
>  						OCFS2_QBLK_RESERVED_SPACE;
>  	oinfo->dqi_gi.dqi_qtree_depth = qtree_depth(&oinfo->dqi_gi);
> -	setup_timer(&oinfo->dqi_sync_timer, qsync_timer_fn,
> -		    (unsigned long)oinfo);
> -	mod_timer(&oinfo->dqi_sync_timer,
> -		  round_jiffies(jiffies + oinfo->dqi_syncjiff));
> +	INIT_DELAYED_WORK(&oinfo->dqi_sync_work, qsync_work_fn);
> +	queue_delayed_work(ocfs2_quota_wq, &oinfo->dqi_sync_work,
> +			   oinfo->dqi_syncjiff);
> +
>  out_err:
>  	mlog_exit(status);
>  	return status;
> @@ -594,21 +596,16 @@ out:
>  	return status;
>  }
>  
> -static void ocfs2_do_qsync(unsigned long oinfo_ptr)
> +static void qsync_work_fn(struct work_struct *work)
>  {
> -	struct ocfs2_mem_dqinfo *oinfo = (struct ocfs2_mem_dqinfo *)oinfo_ptr;
> +	struct ocfs2_mem_dqinfo *oinfo = container_of(work,
> +						      struct ocfs2_mem_dqinfo,
> +						      dqi_sync_work.work);
>  	struct super_block *sb = oinfo->dqi_gqinode->i_sb;
>  
>  	dquot_scan_active(sb, ocfs2_sync_dquot_helper, oinfo->dqi_type);
> -}
> -
> -static void qsync_timer_fn(unsigned long oinfo_ptr)
> -{
> -	struct ocfs2_mem_dqinfo *oinfo = (struct ocfs2_mem_dqinfo *)oinfo_ptr;
> -
> -	pdflush_operation(ocfs2_do_qsync, oinfo_ptr);
> -	mod_timer(&oinfo->dqi_sync_timer,
> -		  round_jiffies(jiffies + oinfo->dqi_syncjiff));
> +	queue_delayed_work(ocfs2_quota_wq, &oinfo->dqi_sync_work,
> +			   oinfo->dqi_syncjiff);
>  }
>  
>  /*
> @@ -1009,3 +1006,20 @@ struct dquot_operations ocfs2_quota_operations = {
>  	.alloc_dquot	= ocfs2_alloc_dquot,
>  	.destroy_dquot	= ocfs2_destroy_dquot,
>  };
> +
> +int ocfs2_quota_setup(void)
> +{
> +	ocfs2_quota_wq = create_workqueue("o2quot");
> +	if (!ocfs2_quota_wq)
> +		return -ENOMEM;
> +	return 0;
> +}
> +
> +void ocfs2_quota_shutdown(void)
> +{
> +	if (ocfs2_quota_wq) {
> +		flush_workqueue(ocfs2_quota_wq);
> +		destroy_workqueue(ocfs2_quota_wq);
> +		ocfs2_quota_wq = NULL;
> +	}
> +}
> diff --git a/fs/ocfs2/quota_local.c b/fs/ocfs2/quota_local.c
> index a5f6e2a..07deec5 100644
> --- a/fs/ocfs2/quota_local.c
> +++ b/fs/ocfs2/quota_local.c
> @@ -780,7 +780,7 @@ static int ocfs2_local_free_info(struct super_block *sb, int type)
>  	/* At this point we know there are no more dquots and thus
>  	 * even if there's some sync in the pdflush queue, it won't
>  	 * find any dquots and return without doing anything */
> -	del_timer_sync(&oinfo->dqi_sync_timer);
> +	cancel_delayed_work_sync(&oinfo->dqi_sync_work);
>  	iput(oinfo->dqi_gqinode);
>  	ocfs2_simple_drop_lockres(OCFS2_SB(sb), &oinfo->dqi_gqlock);
>  	ocfs2_lock_res_free(&oinfo->dqi_gqlock);
> diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
> index a79e67b..43ed113 100644
> --- a/fs/ocfs2/super.c
> +++ b/fs/ocfs2/super.c
> @@ -1326,11 +1326,16 @@ static int __init ocfs2_init(void)
>  		mlog(ML_ERROR, "Unable to create ocfs2 debugfs root.\n");
>  	}
>  
> +	status = ocfs2_quota_setup();
> +	if (status)
> +		goto leave;
> +
>  	ocfs2_set_locking_protocol();
>  
>  	status = register_quota_format(&ocfs2_quota_format);
>  leave:
>  	if (status < 0) {
> +		ocfs2_quota_shutdown();
>  		ocfs2_free_mem_caches();
>  		exit_ocfs2_uptodate_cache();
>  	}
> @@ -1347,6 +1352,8 @@ static void __exit ocfs2_exit(void)
>  {
>  	mlog_entry_void();
>  
> +	ocfs2_quota_shutdown();
> +
>  	if (ocfs2_wq) {
>  		flush_workqueue(ocfs2_wq);
>  		destroy_workqueue(ocfs2_wq);
> -- 
> 1.5.6
> 
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR