Re: [PATCH 8/8] libxfs: Catch non-empty zones on destroy

["Darrick J. Wong" <darrick.wong@oracle.com>]

On Thu, Jan 11, 2018 at 01:37:38PM -0600, Eric Sandeen wrote:
> Move xfs_inode_zone definition to its primary file, and add
> it to the list of zones to release; properly release
> xfs_ili_zone as well.
> 
> Create and use a kmem_zone_destroy which warns if we are
> releasing a non-empty zone when the LIBXFS_LEAK_CHECK
> environment variable is set, wire this into libxfs_destroy(),
> and call that when various tools exit.
> 
> The LIBXFS_LEAK_CHECK environment variable also causes
> the program to exit with failure when a leak is detected.
> 
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
> ---
>  copy/xfs_copy.c     |  1 +
>  db/init.c           |  2 ++
>  include/kmem.h      |  1 +
>  libxfs/init.c       | 38 +++++++++++++++++++++++---------------
>  libxfs/kmem.c       | 14 ++++++++++++++
>  libxfs/rdwr.c       |  2 +-
>  mkfs/xfs_mkfs.c     |  1 +
>  repair/xfs_repair.c |  1 +
>  8 files changed, 44 insertions(+), 16 deletions(-)
> 
> diff --git a/copy/xfs_copy.c b/copy/xfs_copy.c
> index fb37375..648db86 100644
> --- a/copy/xfs_copy.c
> +++ b/copy/xfs_copy.c
> @@ -1214,6 +1214,7 @@ main(int argc, char **argv)
>  
>  	check_errors();
>  	libxfs_umount(mp);
> +	libxfs_destroy();

These added libxfs_destroy calls should go in a separate patch, since
it's a different logical change from complaining about leaks.

>  
>  	return 0;
>  }
> diff --git a/db/init.c b/db/init.c
> index b108a06..29fc344 100644
> --- a/db/init.c
> +++ b/db/init.c
> @@ -236,5 +236,7 @@ close_devices:
>  		libxfs_device_close(x.logdev);
>  	if (x.rtdev)
>  		libxfs_device_close(x.rtdev);
> +	libxfs_destroy();
> +
>  	return exitcode;
>  }
> diff --git a/include/kmem.h b/include/kmem.h
> index 65f0ade..80ce25b 100644
> --- a/include/kmem.h
> +++ b/include/kmem.h
> @@ -31,6 +31,7 @@ typedef struct kmem_zone {
>  } kmem_zone_t;
>  
>  extern kmem_zone_t *kmem_zone_init(int, char *);
> +extern int	kmem_zone_destroy(kmem_zone_t *);
>  extern void	*kmem_zone_alloc(kmem_zone_t *, int);
>  extern void	*kmem_zone_zalloc(kmem_zone_t *, int);
>  
> diff --git a/libxfs/init.c b/libxfs/init.c
> index aea308b..e32f27c 100644
> --- a/libxfs/init.c
> +++ b/libxfs/init.c
> @@ -43,9 +43,7 @@ int libxfs_bhash_size;		/* #buckets in bcache */
>  
>  int	use_xfs_buf_lock;	/* global flag: use xfs_buf_t locks for MT */
>  
> -static void manage_zones(int);	/* setup global zones */
> -
> -kmem_zone_t	*xfs_inode_zone;
> +static int manage_zones(int);	/* setup/teardown global zones */
>  
>  /*
>   * dev_map - map open devices to fd.
> @@ -374,11 +372,12 @@ done:
>  /*
>   * Initialize/destroy all of the zone allocators we use.
>   */
> -static void
> +static int 

Trailing space.  Also, you are being quite optimistic that we won't ever
leak more than 2^31 buff...OH, I see, this is the number of zones with
leaks, not the number of leaked zone items.

>  manage_zones(int release)
>  {
>  	extern kmem_zone_t	*xfs_buf_zone;
>  	extern kmem_zone_t	*xfs_ili_zone;
> +	extern kmem_zone_t	*xfs_inode_zone;
>  	extern kmem_zone_t	*xfs_ifork_zone;
>  	extern kmem_zone_t	*xfs_buf_item_zone;
>  	extern kmem_zone_t	*xfs_da_state_zone;
> @@ -389,16 +388,19 @@ manage_zones(int release)
>  	extern void		xfs_dir_startup();
>  
>  	if (release) {	/* free zone allocation */
> -		kmem_free(xfs_buf_zone);
> -		kmem_free(xfs_inode_zone);
> -		kmem_free(xfs_ifork_zone);
> -		kmem_free(xfs_buf_item_zone);
> -		kmem_free(xfs_da_state_zone);
> -		kmem_free(xfs_btree_cur_zone);
> -		kmem_free(xfs_bmap_free_item_zone);
> -		kmem_free(xfs_trans_zone);
> -		kmem_free(xfs_log_item_desc_zone);
> -		return;
> +		int	leaked = 0;
> +
> +		leaked += kmem_zone_destroy(xfs_buf_zone);
> +		leaked += kmem_zone_destroy(xfs_ili_zone);
> +		leaked += kmem_zone_destroy(xfs_inode_zone);
> +		leaked += kmem_zone_destroy(xfs_ifork_zone);
> +		leaked += kmem_zone_destroy(xfs_buf_item_zone);
> +		leaked += kmem_zone_destroy(xfs_da_state_zone);
> +		leaked += kmem_zone_destroy(xfs_btree_cur_zone);
> +		leaked += kmem_zone_destroy(xfs_bmap_free_item_zone);
> +		leaked += kmem_zone_destroy(xfs_trans_zone);
> +		leaked += kmem_zone_destroy(xfs_log_item_desc_zone);
> +		return leaked;
>  	}
>  	/* otherwise initialise zone allocation */
>  	xfs_buf_zone = kmem_zone_init(sizeof(xfs_buf_t), "xfs_buffer");
> @@ -420,6 +422,8 @@ manage_zones(int release)
>  	xfs_log_item_desc_zone = kmem_zone_init(
>  			sizeof(struct xfs_log_item_desc), "xfs_log_item_desc");
>  	xfs_dir_startup();
> +
> +	return 0;
>  }
>  
>  /*
> @@ -888,10 +892,14 @@ libxfs_umount(xfs_mount_t *mp)
>  void
>  libxfs_destroy(void)
>  {
> -	manage_zones(1);
> +	int	leaked;
> +
> +	leaked = manage_zones(1);
>  	libxfs_bcache_purge();
>  	libxfs_bcache_free();
>  	cache_destroy(libxfs_bcache);
> +	if (getenv("LIBXFS_LEAK_CHECK") && leaked)
> +		exit(1);
>  }
>  
>  int
> diff --git a/libxfs/kmem.c b/libxfs/kmem.c
> index c8bcb50..d599b3d 100644
> --- a/libxfs/kmem.c
> +++ b/libxfs/kmem.c
> @@ -23,6 +23,20 @@ kmem_zone_init(int size, char *name)
>  	return ptr;
>  }
>  
> +int
> +kmem_zone_destroy(kmem_zone_t *zone)

struct kmem_zone	*zone ?

> +{
> +	int	leaked = 0;
> +
> +	if (getenv("LIBXFS_LEAK_CHECK") && zone->allocated) {
> +		leaked = 1;
> +		printf("zone %s freed with %d items allocated\n",
> +					zone->zone_name, zone->allocated);
> +	}
> +	free(zone);
> +	return leaked;
> +}
> +
>  void *
>  kmem_zone_alloc(kmem_zone_t *zone, int flags)
>  {
> diff --git a/libxfs/rdwr.c b/libxfs/rdwr.c
> index 1dcabdd..fdb2865 100644
> --- a/libxfs/rdwr.c
> +++ b/libxfs/rdwr.c
> @@ -1352,8 +1352,8 @@ struct cache_operations libxfs_bcache_operations = {
>   * Inode cache stubs.
>   */
>  
> +kmem_zone_t		*xfs_inode_zone;
>  extern kmem_zone_t	*xfs_ili_zone;
> -extern kmem_zone_t	*xfs_inode_zone;

/me wonders what's going on here?  Alphabetizing, I guess...

<shrug> meh, whatever :)

--D

>  
>  int
>  libxfs_iget(xfs_mount_t *mp, xfs_trans_t *tp, xfs_ino_t ino, uint lock_flags,
> diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
> index 5f1ac9f..e08d1d1 100644
> --- a/mkfs/xfs_mkfs.c
> +++ b/mkfs/xfs_mkfs.c
> @@ -4028,6 +4028,7 @@ main(
>  	if (xi.logdev && xi.logdev != xi.ddev)
>  		libxfs_device_close(xi.logdev);
>  	libxfs_device_close(xi.ddev);
> +	libxfs_destroy();
>  
>  	return 0;
>  }
> diff --git a/repair/xfs_repair.c b/repair/xfs_repair.c
> index b2dd91b..312a0d0 100644
> --- a/repair/xfs_repair.c
> +++ b/repair/xfs_repair.c
> @@ -1082,6 +1082,7 @@ _("Note - stripe unit (%d) and width (%d) were copied from a backup superblock.\
>  	if (x.logdev && x.logdev != x.ddev)
>  		libxfs_device_close(x.logdev);
>  	libxfs_device_close(x.ddev);
> +	libxfs_destroy();
>  
>  	if (verbose)
>  		summary_report();
> -- 
> 1.8.3.1
> 
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