xfs: per-filesystem stats in sysfs

This patch implements per-filesystem stats objects in sysfs. It
depends on the application of the previous patch series that
develops the infrastructure to support both xfs global stats and
xfs per-fs stats in sysfs.

Stats objects are instantiated when an xfs filesystem is mounted
and deleted on unmount. With this patch, the stats directory is
created and populated with the familiar stats and stats_clear files.
Example:
        /sys/fs/xfs/sda9/stats/stats
        /sys/fs/xfs/sda9/stats/stats_clear

With this patch, the individual counts within the new per-fs
stats file(s) remain at zero. Functions that use the the macros
to increment, decrement, and add-to the per-fs stats counts will
be covered in a separate new patch to follow this one. Note that
the counts within the global stats file (/sys/fs/xfs/stats/stats)
advance normally and can be cleared as it was prior to this patch.

[dchinner: move setup/teardown to xfs_fs_{fill|put}_super() so
it is down before/after any path that uses the per-mount stats. ]

Signed-off-by: Bill O'Donnell <billodo@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index bf92e0c037c7378cadf1848a4324968170e1ae29..eb498ce39f4cc162595c714416b45b850dd5eb3c 100644 (file)
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -693,10 +693,15 @@ xfs_mountfs(
        if (error)
                goto out;
 
-       error = xfs_uuid_mount(mp);
+       error = xfs_sysfs_init(&mp->m_stats.xs_kobj, &xfs_stats_ktype,
+                              &mp->m_kobj, "stats");
        if (error)
                goto out_remove_sysfs;
 
+       error = xfs_uuid_mount(mp);
+       if (error)
+               goto out_del_stats;
+
        /*
         * Set the minimum read and write sizes
         */
@@ -971,6 +976,8 @@ xfs_mountfs(
        xfs_da_unmount(mp);
  out_remove_uuid:
        xfs_uuid_unmount(mp);
+ out_del_stats:
+       xfs_sysfs_del(&mp->m_stats.xs_kobj);
  out_remove_sysfs:
        xfs_sysfs_del(&mp->m_kobj);
  out:
@@ -1047,6 +1054,7 @@ xfs_unmountfs(
                xfs_warn(mp, "Unable to update superblock counters. "
                                "Freespace may not be correct on next mount.");
 
+
        xfs_log_unmount(mp);
        xfs_da_unmount(mp);
        xfs_uuid_unmount(mp);
@@ -1056,6 +1064,7 @@ xfs_unmountfs(
 #endif
        xfs_free_perag(mp);
 
+       xfs_sysfs_del(&mp->m_stats.xs_kobj);
        xfs_sysfs_del(&mp->m_kobj);
 }
 

diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 7999e91cd49ad862d5fbeb29a5e5487ed94509a8..8795272cb6622fac31164a494bf0233a6ffbd3f8 100644 (file)
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -127,6 +127,7 @@ typedef struct xfs_mount {
        int64_t                 m_low_space[XFS_LOWSP_MAX];
                                                /* low free space thresholds */
        struct xfs_kobj         m_kobj;
+       struct xstats           m_stats;        /* per-fs stats */
 
        struct workqueue_struct *m_buf_workqueue;
        struct workqueue_struct *m_data_workqueue;

diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index e1a35a5104e8e02899ce9cd8af1462c56643d084..9d11d3ea803088aa784e8c1137d3f5048e692dcb 100644 (file)
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1474,9 +1474,16 @@ xfs_fs_fill_super(
        if (error)
                goto out_destroy_workqueues;
 
+       /* Allocate stats memory before we do operations that might use it */
+       mp->m_stats.xs_stats = alloc_percpu(struct xfsstats);
+       if (!mp->m_stats.xs_stats) {
+               error = PTR_ERR(mp->m_stats.xs_stats);
+               goto out_destroy_counters;
+       }
+
        error = xfs_readsb(mp, flags);
        if (error)
-               goto out_destroy_counters;
+               goto out_free_stats;
 
        error = xfs_finish_flags(mp);
        if (error)
@@ -1545,9 +1552,11 @@ xfs_fs_fill_super(
        xfs_filestream_unmount(mp);
  out_free_sb:
        xfs_freesb(mp);
+ out_free_stats:
+       free_percpu(mp->m_stats.xs_stats);
  out_destroy_counters:
        xfs_destroy_percpu_counters(mp);
-out_destroy_workqueues:
+ out_destroy_workqueues:
        xfs_destroy_mount_workqueues(mp);
  out_close_devices:
        xfs_close_devices(mp);
@@ -1574,6 +1583,7 @@ xfs_fs_put_super(
        xfs_unmountfs(mp);
 
        xfs_freesb(mp);
+       free_percpu(mp->m_stats.xs_stats);
        xfs_destroy_percpu_counters(mp);
        xfs_destroy_mount_workqueues(mp);
        xfs_close_devices(mp);