Re: [PATCH v3 6/6] libfrog: enable cached report zones

["Darrick J. Wong" <djwong@kernel.org>]

On Sat, Dec 20, 2025 at 11:53:26AM +0900, Damien Le Moal wrote:
> Modify the function xfrog_report_zones() to default to always trying
> first a cached report zones using the BLKREPORTZONEV2 ioctl.
> If the kernel does not support BLKREPORTZONEV2, fall back to the
> (slower) regular report zones BLKREPORTZONE ioctl.
> 
> TO enable this feature even if xfsprogs is compiled on a system where
> linux/blkzoned.h does not define BLKREPORTZONEV2, this ioctl is defined
> in libfrog/zones.h, together with the BLK_ZONE_REP_CACHED flag and the
> BLK_ZONE_COND_ACTIVE zone condition.
> 
> Since a cached report zone  always return the condition
> BLK_ZONE_COND_ACTIVE for any zone that is implicitly open, explicitly
> open or closed, the function xfs_zone_validate_seq() is modified to
> handle this new condition as being equivalent to the implicit open,
> explicit open or closed conditions.
> 
> Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
> ---
>  libfrog/zones.c    | 11 ++++++++++-
>  libfrog/zones.h    |  9 +++++++++
>  libxfs/xfs_zones.c |  3 ++-
>  3 files changed, 21 insertions(+), 2 deletions(-)
> 
> diff --git a/libfrog/zones.c b/libfrog/zones.c
> index 0187edce5fa4..8b45066de176 100644
> --- a/libfrog/zones.c
> +++ b/libfrog/zones.c
> @@ -27,10 +27,19 @@ _("Failed to allocate memory for reporting zones.\n"));
>  		return NULL;
>  	}
>  
> +	/*
> +	 * Try cached report zones first. If this fails, fallback to the regular
> +	 * (slower) report zones.
> +	 */
>  	rep->sector = sector;
>  	rep->nr_zones = ZONES_PER_REPORT;
> +	rep->flags = BLK_ZONE_REP_CACHED;
>  
> -	ret = ioctl(fd, BLKREPORTZONE, rep);
> +	ret = ioctl(fd, BLKREPORTZONEV2, rep);
> +	if (ret < 0 && errno == ENOTTY) {
> +		rep->flags = 0;
> +		ret = ioctl(fd, BLKREPORTZONE, rep);
> +	}
>  	if (ret) {
>  		fprintf(stderr,
>  _("ioctl(BLKREPORTZONE) failed: %d!\n"), -errno);
> diff --git a/libfrog/zones.h b/libfrog/zones.h
> index 66df7a426a27..4605aea93114 100644
> --- a/libfrog/zones.h
> +++ b/libfrog/zones.h
> @@ -8,6 +8,15 @@
>  #include <stdint.h>
>  #include <linux/blkzoned.h>
>  
> +/*
> + * Cached report ioctl (/usr/include/linux/blkzoned.h)
> + */
> +#ifndef BLKREPORTZONEV2
> +#define BLKREPORTZONEV2		_IOWR(0x12, 142, struct blk_zone_report)
> +#define BLK_ZONE_REP_CACHED	(1U << 31)
> +#define BLK_ZONE_COND_ACTIVE	0xff

Of these three definitions, only BLK_ZONE_COND_ACTIVE is actually used
outside of libfrog/zones.c, right?  I suggest defining BLKREPORTZONEV2
and BLK_ZONE_REP_CACHED there instead of zones.h to reduce the number of
symbols floating around.

(The rest of the code changes look ok to me)

--D

> +#endif
> +
>  struct blk_zone_report	*xfrog_report_zones(int	fd, uint64_t sector);
>  
>  #endif /* __LIBFROG_ZONE_H__ */
> diff --git a/libxfs/xfs_zones.c b/libxfs/xfs_zones.c
> index 7a81d83f5b3e..3c89a89ca21e 100644
> --- a/libxfs/xfs_zones.c
> +++ b/libxfs/xfs_zones.c
> @@ -3,7 +3,7 @@
>   * Copyright (c) 2023-2025 Christoph Hellwig.
>   * Copyright (c) 2024-2025, Western Digital Corporation or its affiliates.
>   */
> -#include <linux/blkzoned.h>
> +#include <libfrog/zones.h>
>  #include "libxfs_priv.h"
>  #include "xfs.h"
>  #include "xfs_fs.h"
> @@ -97,6 +97,7 @@ xfs_zone_validate_seq(
>  	case BLK_ZONE_COND_IMP_OPEN:
>  	case BLK_ZONE_COND_EXP_OPEN:
>  	case BLK_ZONE_COND_CLOSED:
> +	case BLK_ZONE_COND_ACTIVE:
>  		return xfs_zone_validate_wp(zone, rtg, write_pointer);
>  	case BLK_ZONE_COND_FULL:
>  		return xfs_zone_validate_full(zone, rtg, write_pointer);
> -- 
> 2.52.0
> 
>