git: 6468cd8e0ef9 - main - mount: add vnode usage per file system with mount -v

The branch main has been updated by ambrisko:

URL: https://cgit.FreeBSD.org/src/commit/?id=6468cd8e0ef9d1d3331e9de26cd2be59bc778494

commit 6468cd8e0ef9d1d3331e9de26cd2be59bc778494
Author:     Doug Ambrisko <ambrisko@FreeBSD.org>
AuthorDate: 2022-06-13 14:56:38 +0000
Commit:     Doug Ambrisko <ambrisko@FreeBSD.org>
CommitDate: 2022-06-13 14:56:38 +0000

    mount: add vnode usage per file system with mount -v
    
    This avoids the need to drop into the ddb to figure out vnode
    usage per file system.  It helps to see if they are or are not
    being freed.  Suggestion to report active vnode count was from
    kib@
    
    Reviewed by:    kib
    Differential Revision: https://reviews.freebsd.org/D35436
---
 sbin/mount/mount.c   |  7 +++++++
 sys/kern/vfs_mount.c | 12 ++++++++++++
 sys/sys/mount.h      |  4 +++-
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/sbin/mount/mount.c b/sbin/mount/mount.c
index 79d9d6cb0caf..bd3d0073c474 100644
--- a/sbin/mount/mount.c
+++ b/sbin/mount/mount.c
@@ -692,6 +692,13 @@ prmount(struct statfs *sfp)
 			xo_emit("{D:, }{Lw:fsid}{:fsid}", fsidbuf);
 			free(fsidbuf);
 		}
+		if (sfp->f_nvnodelistsize != 0 || sfp->f_avnodecount != 0) {
+			xo_open_container("vnodes");
+			xo_emit("{D:, }{Lwc:vnodes}{Lw:count}{w:count/%ju}{Lw:active}{:active/%ju}",
+			    (uintmax_t)sfp->f_nvnodelistsize,
+			    (uintmax_t)sfp->f_avnodecount);
+			xo_close_container("vnodes");
+		}
 	}
 	xo_emit("{D:)}\n");
 }
diff --git a/sys/kern/vfs_mount.c b/sys/kern/vfs_mount.c
index 71a40fd97a9c..e3818b67e841 100644
--- a/sys/kern/vfs_mount.c
+++ b/sys/kern/vfs_mount.c
@@ -2610,6 +2610,8 @@ vfs_copyopt(struct vfsoptlist *opts, const char *name, void *dest, int len)
 int
 __vfs_statfs(struct mount *mp, struct statfs *sbp)
 {
+	struct vnode *vp;
+	uint32_t count;
 
 	/*
 	 * Filesystems only fill in part of the structure for updates, we
@@ -2624,6 +2626,16 @@ __vfs_statfs(struct mount *mp, struct statfs *sbp)
 	sbp->f_version = STATFS_VERSION;
 	sbp->f_namemax = NAME_MAX;
 	sbp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
+	sbp->f_nvnodelistsize = mp->mnt_nvnodelistsize;
+
+	count = 0;
+	MNT_ILOCK(mp);
+	TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
+		if (vrefcnt(vp) > 0) /* racy but does not matter */
+			count++;
+	}
+	MNT_IUNLOCK(mp);
+	sbp->f_avnodecount = count;
 
 	return (mp->mnt_op->vfs_statfs(mp, sbp));
 }
diff --git a/sys/sys/mount.h b/sys/sys/mount.h
index 3383bfe8f431..edac64171f9a 100644
--- a/sys/sys/mount.h
+++ b/sys/sys/mount.h
@@ -91,7 +91,9 @@ struct statfs {
 	uint64_t f_asyncwrites;		/* count of async writes since mount */
 	uint64_t f_syncreads;		/* count of sync reads since mount */
 	uint64_t f_asyncreads;		/* count of async reads since mount */
-	uint64_t f_spare[10];		/* unused spare */
+	uint32_t f_nvnodelistsize;	/* # of vnodes */
+	uint32_t f_avnodecount;		/* # of active vnodes */
+	uint64_t f_spare[9];		/* unused spare */
 	uint32_t f_namemax;		/* maximum filename length */
 	uid_t	  f_owner;		/* user that mounted the filesystem */
 	fsid_t	  f_fsid;		/* filesystem id */