diff mbox series

[2/7] repair: Protect bad inode list with mutex

Message ID 20201022051537.2286402-3-david@fromorbit.com (mailing list archive)
State New
Headers show
Series repair: Phase 6 performance improvements | expand

Commit Message

Dave Chinner Oct. 22, 2020, 5:15 a.m. UTC
From: Dave Chinner <dchinner@redhat.com>

To enable phase 6 parallelisation, we need to protect the bad inode
list from concurrent modification and/or access. Wrap it with a
mutex and clean up the nasty typedefs.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
 repair/dir2.c | 32 +++++++++++++++++++++-----------
 1 file changed, 21 insertions(+), 11 deletions(-)

Comments

Darrick J. Wong Oct. 22, 2020, 5:45 a.m. UTC | #1
On Thu, Oct 22, 2020 at 04:15:32PM +1100, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
> 
> To enable phase 6 parallelisation, we need to protect the bad inode
> list from concurrent modification and/or access. Wrap it with a
> mutex and clean up the nasty typedefs.
> 
> Signed-off-by: Dave Chinner <dchinner@redhat.com>

/methinks the typedef removal ought to be a separate commit,
but otherwise:

Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

--D

> ---
>  repair/dir2.c | 32 +++++++++++++++++++++-----------
>  1 file changed, 21 insertions(+), 11 deletions(-)
> 
> diff --git a/repair/dir2.c b/repair/dir2.c
> index eabdb4f2d497..23333e59a382 100644
> --- a/repair/dir2.c
> +++ b/repair/dir2.c
> @@ -20,40 +20,50 @@
>   * Known bad inode list.  These are seen when the leaf and node
>   * block linkages are incorrect.
>   */
> -typedef struct dir2_bad {
> +struct dir2_bad {
>  	xfs_ino_t	ino;
>  	struct dir2_bad	*next;
> -} dir2_bad_t;
> +};
>  
> -static dir2_bad_t *dir2_bad_list;
> +static struct dir2_bad	*dir2_bad_list;
> +pthread_mutex_t		dir2_bad_list_lock = PTHREAD_MUTEX_INITIALIZER;
>  
>  static void
>  dir2_add_badlist(
>  	xfs_ino_t	ino)
>  {
> -	dir2_bad_t	*l;
> +	struct dir2_bad	*l;
>  
> -	if ((l = malloc(sizeof(dir2_bad_t))) == NULL) {
> +	l = malloc(sizeof(*l));
> +	if (!l) {
>  		do_error(
>  _("malloc failed (%zu bytes) dir2_add_badlist:ino %" PRIu64 "\n"),
> -			sizeof(dir2_bad_t), ino);
> +			sizeof(*l), ino);
>  		exit(1);
>  	}
> +	pthread_mutex_lock(&dir2_bad_list_lock);
>  	l->next = dir2_bad_list;
>  	dir2_bad_list = l;
>  	l->ino = ino;
> +	pthread_mutex_unlock(&dir2_bad_list_lock);
>  }
>  
>  int
>  dir2_is_badino(
>  	xfs_ino_t	ino)
>  {
> -	dir2_bad_t	*l;
> +	struct dir2_bad	*l;
> +	int		ret = 0;
>  
> -	for (l = dir2_bad_list; l; l = l->next)
> -		if (l->ino == ino)
> -			return 1;
> -	return 0;
> +	pthread_mutex_lock(&dir2_bad_list_lock);
> +	for (l = dir2_bad_list; l; l = l->next) {
> +		if (l->ino == ino) {
> +			ret = 1;
> +			break;
> +		}
> +	}
> +	pthread_mutex_unlock(&dir2_bad_list_lock);
> +	return ret;
>  }
>  
>  /*
> -- 
> 2.28.0
>
Christoph Hellwig Oct. 29, 2020, 9:35 a.m. UTC | #2
On Thu, Oct 22, 2020 at 04:15:32PM +1100, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
> 
> To enable phase 6 parallelisation, we need to protect the bad inode
> list from concurrent modification and/or access. Wrap it with a
> mutex and clean up the nasty typedefs.

The patch itself looks good, but if you touch this code anyway, the
linked list here seems like an incredibly suboptimal data structure.
Even just a simple array that gets realloced would seems better.
diff mbox series

Patch

diff --git a/repair/dir2.c b/repair/dir2.c
index eabdb4f2d497..23333e59a382 100644
--- a/repair/dir2.c
+++ b/repair/dir2.c
@@ -20,40 +20,50 @@ 
  * Known bad inode list.  These are seen when the leaf and node
  * block linkages are incorrect.
  */
-typedef struct dir2_bad {
+struct dir2_bad {
 	xfs_ino_t	ino;
 	struct dir2_bad	*next;
-} dir2_bad_t;
+};
 
-static dir2_bad_t *dir2_bad_list;
+static struct dir2_bad	*dir2_bad_list;
+pthread_mutex_t		dir2_bad_list_lock = PTHREAD_MUTEX_INITIALIZER;
 
 static void
 dir2_add_badlist(
 	xfs_ino_t	ino)
 {
-	dir2_bad_t	*l;
+	struct dir2_bad	*l;
 
-	if ((l = malloc(sizeof(dir2_bad_t))) == NULL) {
+	l = malloc(sizeof(*l));
+	if (!l) {
 		do_error(
 _("malloc failed (%zu bytes) dir2_add_badlist:ino %" PRIu64 "\n"),
-			sizeof(dir2_bad_t), ino);
+			sizeof(*l), ino);
 		exit(1);
 	}
+	pthread_mutex_lock(&dir2_bad_list_lock);
 	l->next = dir2_bad_list;
 	dir2_bad_list = l;
 	l->ino = ino;
+	pthread_mutex_unlock(&dir2_bad_list_lock);
 }
 
 int
 dir2_is_badino(
 	xfs_ino_t	ino)
 {
-	dir2_bad_t	*l;
+	struct dir2_bad	*l;
+	int		ret = 0;
 
-	for (l = dir2_bad_list; l; l = l->next)
-		if (l->ino == ino)
-			return 1;
-	return 0;
+	pthread_mutex_lock(&dir2_bad_list_lock);
+	for (l = dir2_bad_list; l; l = l->next) {
+		if (l->ino == ino) {
+			ret = 1;
+			break;
+		}
+	}
+	pthread_mutex_unlock(&dir2_bad_list_lock);
+	return ret;
 }
 
 /*