xfs: export zone stats in /proc/*/mountstats

Add the per-zone life time hint and the used block distribution
for fully written zones, grouping reclaimable zones in fixed-percentage
buckets spanning 0..9%, 10..19% and full zones as 100% used as well as a
few statistics about the zone allocator and open and reclaimable zones
in /proc/*/mountstats.

This gives good insight into data fragmentation and data placement
success rate.

Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
Co-developed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
index e38838409271691e34e80a45d6dc202e869739fe..5bf501cf827172f836f718faafc1695ec8ecb979 100644 (file)
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -140,6 +140,7 @@ xfs-$(CONFIG_XFS_QUOTA)             += xfs_dquot.o \
 xfs-$(CONFIG_XFS_RT)           += xfs_rtalloc.o \
                                   xfs_zone_alloc.o \
                                   xfs_zone_gc.o \
+                                  xfs_zone_info.o \
                                   xfs_zone_space_resv.o
 
 xfs-$(CONFIG_XFS_POSIX_ACL)    += xfs_acl.o

diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 134859a3719d6ccb72c30fb6c4aa4cee557cde9b..877332ffd84b1866da4a442c332a995286a133f7 100644 (file)
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1262,6 +1262,10 @@ xfs_fs_show_stats(
        struct seq_file         *m,
        struct dentry           *root)
 {
+       struct xfs_mount        *mp = XFS_M(root->d_sb);
+
+       if (xfs_has_zoned(mp) && IS_ENABLED(CONFIG_XFS_RT))
+               xfs_zoned_show_stats(m, mp);
        return 0;
 }
 

diff --git a/fs/xfs/xfs_zone_alloc.h b/fs/xfs/xfs_zone_alloc.h
index 1269390bfcdaa16745afb14624eac5c14ebbd288..ecf39106704c2fd76c61d499bdf3a647faf58ac7 100644 (file)
--- a/fs/xfs/xfs_zone_alloc.h
+++ b/fs/xfs/xfs_zone_alloc.h
@@ -44,6 +44,7 @@ void xfs_mark_rtg_boundary(struct iomap_ioend *ioend);
 
 uint64_t xfs_zoned_default_resblks(struct xfs_mount *mp,
                enum xfs_free_counter ctr);
+void xfs_zoned_show_stats(struct seq_file *m, struct xfs_mount *mp);
 
 #ifdef CONFIG_XFS_RT
 int xfs_mount_zones(struct xfs_mount *mp);

diff --git a/fs/xfs/xfs_zone_info.c b/fs/xfs/xfs_zone_info.c
new file mode 100644 (file)
index 0000000..7ba0a59
--- /dev/null
+++ b/fs/xfs/xfs_zone_info.c
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2023-2025 Christoph Hellwig.
+ * Copyright (c) 2024-2025, Western Digital Corporation or its affiliates.
+ */
+#include "xfs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_inode.h"
+#include "xfs_rtgroup.h"
+#include "xfs_zone_alloc.h"
+#include "xfs_zone_priv.h"
+
+static const char xfs_write_hint_shorthand[6][16] = {
+       "NOT_SET", "NONE", "SHORT", "MEDIUM", "LONG", "EXTREME"};
+
+static inline const char *
+xfs_write_hint_to_str(
+       uint8_t                 write_hint)
+{
+       if (write_hint > WRITE_LIFE_EXTREME)
+               return "UNKNOWN";
+       return xfs_write_hint_shorthand[write_hint];
+}
+
+static void
+xfs_show_open_zone(
+       struct seq_file         *m,
+       struct xfs_open_zone    *oz)
+{
+       seq_printf(m, "\t  zone %d, wp %u, written %u, used %u, hint %s\n",
+               rtg_rgno(oz->oz_rtg),
+               oz->oz_write_pointer, oz->oz_written,
+               rtg_rmap(oz->oz_rtg)->i_used_blocks,
+               xfs_write_hint_to_str(oz->oz_write_hint));
+}
+
+static void
+xfs_show_full_zone_used_distribution(
+       struct seq_file         *m,
+       struct xfs_mount        *mp)
+{
+       struct xfs_zone_info    *zi = mp->m_zone_info;
+       unsigned int            reclaimable = 0, full, i;
+
+       spin_lock(&zi->zi_used_buckets_lock);
+       for (i = 0; i < XFS_ZONE_USED_BUCKETS; i++) {
+               unsigned int entries = zi->zi_used_bucket_entries[i];
+
+               seq_printf(m, "\t  %2u..%2u%%: %u\n",
+                               i * (100 / XFS_ZONE_USED_BUCKETS),
+                               (i + 1) * (100 / XFS_ZONE_USED_BUCKETS) - 1,
+                               entries);
+               reclaimable += entries;
+       }
+       spin_unlock(&zi->zi_used_buckets_lock);
+
+       full = mp->m_sb.sb_rgcount;
+       if (zi->zi_open_gc_zone)
+               full--;
+       full -= zi->zi_nr_open_zones;
+       full -= atomic_read(&zi->zi_nr_free_zones);
+       full -= reclaimable;
+
+       seq_printf(m, "\t     100%%: %u\n", full);
+}
+
+void
+xfs_zoned_show_stats(
+       struct seq_file         *m,
+       struct xfs_mount        *mp)
+{
+       struct xfs_zone_info    *zi = mp->m_zone_info;
+       struct xfs_open_zone    *oz;
+
+       seq_puts(m, "\n");
+
+       seq_printf(m, "\tuser free RT blocks: %lld\n",
+               xfs_sum_freecounter(mp, XC_FREE_RTEXTENTS));
+       seq_printf(m, "\treserved free RT blocks: %lld\n",
+               mp->m_resblks[XC_FREE_RTEXTENTS].avail);
+       seq_printf(m, "\tuser available RT blocks: %lld\n",
+               xfs_sum_freecounter(mp, XC_FREE_RTAVAILABLE));
+       seq_printf(m, "\treserved available RT blocks: %lld\n",
+               mp->m_resblks[XC_FREE_RTAVAILABLE].avail);
+       seq_printf(m, "\tRT reservations required: %d\n",
+               !list_empty_careful(&zi->zi_reclaim_reservations));
+       seq_printf(m, "\tRT GC required: %d\n",
+               xfs_zoned_need_gc(mp));
+
+       seq_printf(m, "\tfree zones: %d\n", atomic_read(&zi->zi_nr_free_zones));
+       seq_puts(m, "\topen zones:\n");
+       spin_lock(&zi->zi_open_zones_lock);
+       list_for_each_entry(oz, &zi->zi_open_zones, oz_entry)
+               xfs_show_open_zone(m, oz);
+       if (zi->zi_open_gc_zone) {
+               seq_puts(m, "\topen gc zone:\n");
+               xfs_show_open_zone(m, zi->zi_open_gc_zone);
+       }
+       spin_unlock(&zi->zi_open_zones_lock);
+       seq_puts(m, "\tused blocks distribution (fully written zones):\n");
+       xfs_show_full_zone_used_distribution(m, mp);
+}