Date: Mon, 3 Nov 2025 15:54:51 GMT From: Mateusz Piotrowski <0mp@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 2020e76450e2 - main - dtrace_vfs.4: Document the DTrace vfs provider Message-ID: <202511031554.5A3Fspwt040964@gitrepo.freebsd.org>
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The branch main has been updated by 0mp: URL: https://cgit.FreeBSD.org/src/commit/?id=2020e76450e2705d33d673a3d183c8f0a3910e28 commit 2020e76450e2705d33d673a3d183c8f0a3910e28 Author: Mateusz Piotrowski <0mp@FreeBSD.org> AuthorDate: 2025-11-03 15:54:10 +0000 Commit: Mateusz Piotrowski <0mp@FreeBSD.org> CommitDate: 2025-11-03 15:54:11 +0000 dtrace_vfs.4: Document the DTrace vfs provider Reviewed by: bcr MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D51317 --- cddl/contrib/opensolaris/cmd/dtrace/dtrace.1 | 3 +- share/man/man4/Makefile | 3 +- share/man/man4/dtrace_vfs.4 | 97 ++++++++++++++++++++++++++++ share/man/man9/VFS.9 | 3 +- 4 files changed, 103 insertions(+), 3 deletions(-) diff --git a/cddl/contrib/opensolaris/cmd/dtrace/dtrace.1 b/cddl/contrib/opensolaris/cmd/dtrace/dtrace.1 index e263b936700d..f09cbe1ac27b 100644 --- a/cddl/contrib/opensolaris/cmd/dtrace/dtrace.1 +++ b/cddl/contrib/opensolaris/cmd/dtrace/dtrace.1 @@ -20,7 +20,7 @@ .\" .\" $FreeBSD$ .\" -.Dd July 30, 2025 +.Dd November 3, 2025 .Dt DTRACE 1 .Os .Sh NAME @@ -1305,6 +1305,7 @@ in .Xr dtrace_tcp 4 , .Xr dtrace_udp 4 , .Xr dtrace_udplite 4 , +.Xr dtrace_vfs 4 , .Xr elf 5 , .Xr d 7 , .Xr tracing 7 , diff --git a/share/man/man4/Makefile b/share/man/man4/Makefile index fe744776d9b3..95618227a010 100644 --- a/share/man/man4/Makefile +++ b/share/man/man4/Makefile @@ -1017,7 +1017,8 @@ _dtrace_provs= dtrace_audit.4 \ dtrace_sctp.4 \ dtrace_tcp.4 \ dtrace_udp.4 \ - dtrace_udplite.4 + dtrace_udplite.4 \ + dtrace_vfs.4 MLINKS+= dtrace_audit.4 dtaudit.4 .endif diff --git a/share/man/man4/dtrace_vfs.4 b/share/man/man4/dtrace_vfs.4 new file mode 100644 index 000000000000..528d5da42f3d --- /dev/null +++ b/share/man/man4/dtrace_vfs.4 @@ -0,0 +1,97 @@ +.\" +.\" Copyright (c) 2025 Mateusz Piotrowski <0mp@FreeBSD.org> +.\" +.\" SPDX-License-Identifier: BSD-2-Clause +.\" +.Dd November 3, 2025 +.Dt DTRACE_VFS 4 +.Os +.Sh NAME +.Nm dtrace_vfs +.Nd a DTrace provider for Virtual File System +.Sh SYNOPSIS +.Sm off +.Nm vfs Cm : fplookup : Ar function Cm : Ar name +.Nm vfs Cm : namecache : Ar function Cm : Ar name +.Nm vfs Cm : namei : Ar function Cm : Ar name +.Nm vfs Cm : vop : Ar function Cm : Ar name +.Sm on +.Sh DESCRIPTION +The DTrace +.Nm vfs +provider allows users to trace events in the +.Xr VFS 9 +layer, the kernel interface for file systems on +.Fx . +.Pp +Run +.Ql dtrace -l -P vfs +to list all +.Nm vfs +probes. +Add +.Fl v +to generate program stability reports, +which contain information about the number of probe arguments and their types. +.Pp +The +.Cm fplookup +module defines a single probe, +.Fn vfs:fplookup:lookup:done "struct nameidata *ndp" "int line" "bool status_code" , +that instruments the fast path lookup code in +.Xr VFS 9 . +.Pp +The +.Cm namecache +module provides probes related to the +.Xr VFS 9 +cache. +Consult the source code in +.Pa src/sys/kern/vfs_cache.c +for more details. +.Pp +The +.Cm namei +module manages probes related to pathname translation and lookup operations. +Refer to +.Xr namei 9 +to learn more. +.Pp +The +.Cm vop +module contains probes related to the functions responsible for +.Xr vnode 9 +operations. +.Sh COMPATIBILITY +This provider is specific to +.Fx . +.Sh EXAMPLES +Check what lookups failed to be handled in a lockless manner: +.Bd -literal -offset 2n +# dtrace -n 'vfs:fplookup:lookup:done { @[arg1, arg2] = count(); }' +.Ed +.Sh SEE ALSO +.Xr dtrace 1 , +.Xr d 7 , +.Xr SDT 9 , +.Xr namei 9 , +.Xr VFS 9 +.Rs +.%A Brendan Gregg +.%A Jim Mauro +.%B DTrace: Dynamic Tracing in Oracle Solaris, Mac OS X and FreeBSD +.%I Prentice Hall +.%P pp. 335\(en351 +.%D 2011 +.%U https://www.brendangregg.com/dtracebook/ +.Re +.Sh AUTHORS +.An -nosplit +The +.Fx +.Nm vfs +provider was written by +.An Robert Watson Aq Mt rwatson@FreeBSD.org . +.Pp +This manual page was written by +.An Mateusz Piotrowski Aq Mt 0mp@FreeBSD.org . diff --git a/share/man/man9/VFS.9 b/share/man/man9/VFS.9 index a1d0a19bec13..6ea6570bbf6e 100644 --- a/share/man/man9/VFS.9 +++ b/share/man/man9/VFS.9 @@ -26,7 +26,7 @@ .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. .\" -.Dd February 9, 2010 +.Dd November 3, 2025 .Dt VFS 9 .Os .Sh NAME @@ -42,6 +42,7 @@ function from rather than implementing empty functions or casting to .Fa eopnotsupp . .Sh SEE ALSO +.Xr dtrace_vfs 4 , .Xr VFS_CHECKEXP 9 , .Xr VFS_FHTOVP 9 , .Xr VFS_MOUNT 9 ,help
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