Date: Thu, 8 May 2014 00:44:50 -0700 From: Gleb Kurtsou <gleb@freebsd.org> To: Thomas Quinot <thomas@FreeBSD.ORG> Cc: freebsd-arch@freebsd.org Subject: Re: Proposed extension to stat(1) Message-ID: <20140508074450.GA2678@reks> In-Reply-To: <20140507091213.GA55856@melamine.cuivre.fr.eu.org> References: <20140507091213.GA55856@melamine.cuivre.fr.eu.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On (07/05/2014 11:12), Thomas Quinot wrote:
> I'm proposing the addition of a command line switch -H to stat(1),
> causing arguments to be interpreted as NFS file handles instead of file
> names. This comes in handy when investigating NFS load issues.
>
> (A further possible extension would be to optionally include information
> from statfs/fhstatfs, but that's next on my list :) ).
>
> Thomas.
>
> Index: usr.bin/stat/stat.1
> ===================================================================
> --- usr.bin/stat/stat.1 (révision 265192)
> +++ usr.bin/stat/stat.1 (copie de travail)
> @@ -38,7 +38,7 @@
> .Nd display file status
> .Sh SYNOPSIS
> .Nm
> -.Op Fl FLnq
> +.Op Fl FHLnq
> .Op Fl f Ar format | Fl l | r | s | x
> .Op Fl t Ar timefmt
> .Op Ar
> @@ -124,6 +124,12 @@
> .Fl F
> implies
> .Fl l .
> +.It Fl H
> +Treat each argument as the hexadecimal representation of an NFS file handle,
> +and use
> +.Xr fhstat 2
> +instead of
> +.Xr lstat 2 .
Noting that it requires root may be helpful. 'each argument' confused me
a lot.
> .It Fl L
> Use
> .Xr stat 2
> Index: usr.bin/stat/stat.c
> ===================================================================
> --- usr.bin/stat/stat.c (révision 265192)
> +++ usr.bin/stat/stat.c (copie de travail)
> @@ -50,6 +50,7 @@
> #include <sys/param.h>
> #include <sys/types.h>
> #include <sys/stat.h>
> +#include <sys/mount.h>
>
> #include <ctype.h>
> #include <err.h>
> @@ -203,9 +204,10 @@
> {
> struct stat st;
> int ch, rc, errs, am_readlink;
> - int lsF, fmtchar, usestat, fn, nonl, quiet;
> + int lsF, fmtchar, usestat, nfs_handle, fn, nonl, quiet;
> const char *statfmt, *options, *synopsis;
> char dname[sizeof _PATH_DEV + SPECNAMELEN] = _PATH_DEV;
> + fhandle_t fhnd;
whitespace?
> const char *file;
>
> am_readlink = 0;
> @@ -212,6 +214,7 @@
> lsF = 0;
> fmtchar = '\0';
> usestat = 0;
> + nfs_handle = 0;
whitespace?
> nonl = 0;
> quiet = 0;
> linkfail = 0;
> @@ -226,9 +229,9 @@
> fmtchar = 'f';
> quiet = 1;
> } else {
> - options = "f:FlLnqrst:x";
> + options = "f:FHlLnqrst:x";
> synopsis = "[-FLnq] [-f format | -l | -r | -s | -x] "
> - "[-t timefmt] [file ...]";
> + "[-t timefmt] [file|handle ...]";
> }
>
> while ((ch = getopt(argc, argv, options)) != -1)
> @@ -236,6 +239,9 @@
> case 'F':
> lsF = 1;
> break;
> + case 'H':
> + nfs_handle = 1;
> + break;
Whitespace.
> case 'L':
> usestat = 1;
> break;
> @@ -320,8 +326,33 @@
> file = "(stdin)";
> rc = fstat(STDIN_FILENO, &st);
> } else {
> + int j;
> + char *inval;
> +
> file = argv[0];
> - if (usestat) {
> + if (nfs_handle) {
> + rc = 0;
> + bzero (&fhnd, sizeof fhnd);
Style. Extra space after bzero.
> + j = MIN(2 * sizeof fhnd, strlen(file));
sizeof style.
> + if (j & 1) {
> + rc = -1;
> + } else {
> + while (j) {
> + ((char*) &fhnd)[j / 2 - 1] = strtol(&file[j - 2], &inval, 16);
It's badly broken:
- Result for excessive "01" vs "0102" will differ in
strlen(file) > sizeof(fhnd) * 2 case.
- Will "+1-2" be considered a valid file handle?
- why do we care about strlen(file) != sizeof(fh) case?
> + if (inval != NULL) {
According to strtol(3) such error handling is insufficient.
At least it won't work for strlen(file) > sizeof(fhnd) * 2 case.
> + rc = -1;
> + break;
> + }
> + argv[0][j - 2] = '\0';
First we initialize file = argv[0].
Then we set every third character in argv[0] to '\0'.
Afterwards file is used to print error message or actual result.
> + j -= 2;
> + }
> + if (!rc)
style. rc is not bool.
> + rc = fhstat(&fhnd, &st);
> + else
> + errno = EINVAL;
> + }
> +
> + } else if (usestat) {
> /*
> * Try stat() and if it fails, fall back to
> * lstat() just in case we're examining a
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20140508074450.GA2678>