Friday July 08, 2005

Tracing the Solaris 10 File System Interface

Here's a quick script to trace activity though the central file system interface. Until there is a general file system provider, this script should serve as a basic framework help construct other file system tracing scripts.

# ./voptrace.d /tmp
Event           Device                                                Path  RW     Size   Offset
fop_putpage     -          /tmp//filebench/bin/i386/fastsu                   -     4096     4096
fop_inactive    -          /tmp//filebench/bin/i386/fastsu                   -        0        0
fop_putpage     -          /tmp//filebench/xanadu/WEB-INF/lib/classes12.jar  -     4096   204800
fop_inactive    -          /tmp//filebench/xanadu/WEB-INF/lib/classes12.jar  -        0        0
fop_putpage     -          /tmp/filebench1.63_s10_x86_sparc_pkg.tar.Z        -     4096  7655424
fop_inactive    -          /tmp/filebench1.63_s10_x86_sparc_pkg.tar.Z        -        0        0
fop_putpage     -          /tmp//filebench/xanadu/WEB-INF/lib/classes12.jar  -     4096   782336
fop_inactive    -          /tmp//filebench/xanadu/WEB-INF/lib/classes12.jar  -        0        0
fop_putpage     -          /tmp//filebench/bin/amd64/filebench               -     4096    36864

The source is below:

#!/usr/sbin/dtrace -s

/*
 * Trace the vnode interface
 *
 * USAGE: voptrace.d [/all | /mountname ]
 *
 * Author: Richard McDougall
 *
 * 7/8/2005
 */

#pragma D option quiet

:::BEGIN
{
        printf("%-15s %-10s %51s %2s %8s %8s\n",
                "Event", "Device", "Path", "RW", "Size", "Offset");
        self->trace = 0;
        self->path = "";
}


::fop_*:entry
/self->trace == 0/
{
        /* Get vp: fop_open has a pointer to vp */
        self->vpp = (vnode_t **)arg0;
        self->vp = (vnode_t *)arg0;
        self->vp = probefunc == "fop_open" ? (vnode_t *)*self->vpp : self->vp;

        /* And the containing vfs */
        self->vfsp = self->vp ? self->vp->v_vfsp : 0;

        /* And the paths for the vp and containing vfs */
        self->vfsvp = self->vfsp ? (struct vnode *)((vfs_t *)self->vfsp)->vfs_vnodecovered : 0;
        self->vfspath = self->vfsvp ? stringof(self->vfsvp->v_path) : "unknown";

        /* Check if we should trace the root fs */
        ($1 == "/all" ||
         ($1 == "/" && self->vfsp && \
         (self->vfsp == `rootvfs))) ? self->trace = 1 : self->trace;

        /* Check if we should trace the fs */
        ($1 == "/all" || (self->vfspath == $1)) ? self->trace = 1 : self->trace;
}

/*
 * Trace the entry point to each fop
 *
 */
::fop_*:entry
/self->trace/
{
        self->path = (self->vp != NULL && self->vp->v_path) ? stringof(self->vp->v_path) : "unknown";
        self->len = 0;
        self->off = 0;

        /* Some fops has the len in arg2 */
        (probefunc == "fop_getpage" || \
         probefunc == "fop_putpage" || \
         probefunc == "fop_none") ? self->len = arg2 : 1;

        /* Some fops has the len in arg3 */
        (probefunc == "fop_pageio" || \
         probefunc == "fop_none") ? self->len = arg3 : 1;

        /* Some fops has the len in arg4 */
        (probefunc == "fop_addmap" || \
         probefunc == "fop_map" || \
         probefunc == "fop_delmap") ? self->len = arg4 : 1;

        /* Some fops has the offset in arg1 */
        (probefunc == "fop_addmap" || \
         probefunc == "fop_map" || \
         probefunc == "fop_getpage" || \
         probefunc == "fop_putpage" || \
         probefunc == "fop_seek" || \
         probefunc == "fop_delmap") ? self->off = arg1 : 1;

        /* Some fops has the offset in arg3 */
        (probefunc == "fop_close" || \
         probefunc == "fop_pageio") ? self->off = arg3 : 1;

        /* Some fops has the offset in arg4 */
        probefunc == "fop_frlock" ? self->off = arg4 : 1;

        /* Some fops has the pathname in arg1 */
        self->path = (probefunc == "fop_create" || \
         probefunc == "fop_mkdir" || \
         probefunc == "fop_rmdir" || \
         probefunc == "fop_remove" || \
         probefunc == "fop_lookup") ?
                strjoin(self->path, strjoin("/", stringof(arg1))) : self->path;
        printf("%-15s %-10s %51s %2s %8d %8d\n",
                probefunc,
                "-", self->path, "-", self->len, self->off);
        self->type = probefunc;
}

::fop_*:return
/self->trace == 1/
{
        self->trace = 0;
}


/* Capture any I/O within this fop */
io:::start
/self->trace/
{
        printf("%-15s %-10s %51s %2s %8d %8u\n",
                self->type, args[1]->dev_statname,
                self->path, args[0]->b_flags & B_READ ? "R" : "W",
                args[0]->b_bcount, args[0]->b_blkno);

}

Technorati Tag: OpenSolaris

Technorati Tag: Solaris

Technorati Tag: DTrace

( Jul 08 2005, 04:05:55 PM PDT ) Permalink Comments [1]