From c6ce65cb17aa9321687d1b8a842487f839e1a548 Mon Sep 17 00:00:00 2001 From: Wilfred Mallawa Date: Sun, 1 Mar 2026 10:34:35 +1000 Subject: [PATCH] xfs: add write pointer to xfs_rtgroup_geometry There is currently no XFS ioctl that allows userspace to retrieve the write pointer for a specific realtime group block for zoned XFS. On zoned block devices, userspace can obtain this information via zone reports from the underlying device. However, for zoned XFS operating on regular block devices, no equivalent mechanism exists. Access to the realtime group write pointer is useful to userspace development and analysis tools such as Zonar [1]. So extend the existing struct xfs_rtgroup_geometry to add a new rg_writepointer field. This field is valid if XFS_RTGROUP_GEOM_WRITEPOINTER flag is set. The rg_writepointer field specifies the location of the current writepointer as a block offset into the respective rtgroup. [1] https://lwn.net/Articles/1059364/ Signed-off-by: Wilfred Mallawa Reviewed-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Signed-off-by: Carlos Maiolino --- fs/xfs/libxfs/xfs_fs.h | 5 ++++- fs/xfs/xfs_ioctl.c | 19 +++++++++++++++++++ 2 files changed, 23 insertions(+), 1 deletion(-) diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h index d165de607d17..185f09f327c0 100644 --- a/fs/xfs/libxfs/xfs_fs.h +++ b/fs/xfs/libxfs/xfs_fs.h @@ -995,7 +995,8 @@ struct xfs_rtgroup_geometry { __u32 rg_sick; /* o: sick things in ag */ __u32 rg_checked; /* o: checked metadata in ag */ __u32 rg_flags; /* i/o: flags for this ag */ - __u32 rg_reserved[27]; /* o: zero */ + __u32 rg_writepointer; /* o: write pointer block offset for zoned */ + __u32 rg_reserved[26]; /* o: zero */ }; #define XFS_RTGROUP_GEOM_SICK_SUPER (1U << 0) /* superblock */ #define XFS_RTGROUP_GEOM_SICK_BITMAP (1U << 1) /* rtbitmap */ @@ -1003,6 +1004,8 @@ struct xfs_rtgroup_geometry { #define XFS_RTGROUP_GEOM_SICK_RMAPBT (1U << 3) /* reverse mappings */ #define XFS_RTGROUP_GEOM_SICK_REFCNTBT (1U << 4) /* reference counts */ +#define XFS_RTGROUP_GEOM_WRITEPOINTER (1U << 0) /* write pointer */ + /* Health monitor event domains */ /* affects the whole fs */ diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c index facffdc8dca8..46e234863644 100644 --- a/fs/xfs/xfs_ioctl.c +++ b/fs/xfs/xfs_ioctl.c @@ -37,12 +37,15 @@ #include "xfs_ioctl.h" #include "xfs_xattr.h" #include "xfs_rtbitmap.h" +#include "xfs_rtrmap_btree.h" #include "xfs_file.h" #include "xfs_exchrange.h" #include "xfs_handle.h" #include "xfs_rtgroup.h" #include "xfs_healthmon.h" #include "xfs_verify_media.h" +#include "xfs_zone_priv.h" +#include "xfs_zone_alloc.h" #include #include @@ -413,6 +416,7 @@ xfs_ioc_rtgroup_geometry( { struct xfs_rtgroup *rtg; struct xfs_rtgroup_geometry rgeo; + xfs_rgblock_t highest_rgbno; int error; if (copy_from_user(&rgeo, arg, sizeof(rgeo))) @@ -433,6 +437,21 @@ xfs_ioc_rtgroup_geometry( if (error) return error; + if (xfs_has_zoned(mp)) { + xfs_rtgroup_lock(rtg, XFS_RTGLOCK_RMAP); + if (rtg->rtg_open_zone) { + rgeo.rg_writepointer = rtg->rtg_open_zone->oz_allocated; + } else { + highest_rgbno = xfs_rtrmap_highest_rgbno(rtg); + if (highest_rgbno == NULLRGBLOCK) + rgeo.rg_writepointer = 0; + else + rgeo.rg_writepointer = highest_rgbno + 1; + } + xfs_rtgroup_unlock(rtg, XFS_RTGLOCK_RMAP); + rgeo.rg_flags |= XFS_RTGROUP_GEOM_WRITEPOINTER; + } + if (copy_to_user(arg, &rgeo, sizeof(rgeo))) return -EFAULT; return 0;