[4445] in Athena Bugs
fixes for /bin/df
daemon@ATHENA.MIT.EDU (John Carr)
Wed Mar 7 17:55:54 1990
To: bugs@ATHENA.MIT.EDU
Date: Wed, 07 Mar 90 17:55:30 EST
From: John Carr <jfc@ATHENA.MIT.EDU>
The patches in this message improve the performance of "df".
. df does not try to stat a file to determine if it is a block
special device. A new flag, "-f", overrides this.
. df scans /etc/mtab for an exact match between a passed filename
and a mountpoint before stat-ing every mounted filesystem.
. df will now stop stat-ing files when it find the filesystem
containing the file passed as an argument (the current version
stats _every_ filesystem, not stopping when it finds the right
one).
This should prevent many problems when NFS servers are down or slow.
Updated documentation is included.
[see changes.70 #53]
*** /source/bsd-4.3/common/bin/df.c Wed Apr 13 14:08:41 1988
--- df.new.c Wed Mar 7 17:47:50 1990
***************
*** 15,21 ****
#include <mntent.h>
char *mpath();
! int iflag;
int type;
char *typestr;
--- 15,21 ----
#include <mntent.h>
char *mpath();
! int iflag, fflag;
int type;
char *typestr;
***************
*** 34,40 ****
{
int i;
struct stat statb;
- char tmpname[1024];
while (argc > 1 && argv[1][0]=='-') {
switch (argv[1][1]) {
--- 34,39 ----
***************
*** 50,55 ****
--- 49,58 ----
argc--;
break;
+ case 'f':
+ fflag++;
+ break;
+
default:
usage();
}
***************
*** 74,94 ****
}
while (mnt = getmntent(mtabp)) {
if (strcmp(mnt->mnt_type, MNTTYPE_IGNORE) == 0 ||
! strcmp(mnt->mnt_type, MNTTYPE_SWAP) == 0)
continue;
! if (!strcmp(mnt->mnt_type, MNTTYPE_NFS) && iflag)
! continue;
! if (type && strcmp(typestr, mnt->mnt_type)) {
! continue;
! }
! if ((stat(mnt->mnt_fsname, &statb) >= 0) &&
! (((statb.st_mode & S_IFBLK) == S_IFBLK) ||
! ((statb.st_mode & S_IFCHR) == S_IFCHR))) {
! strcpy(tmpname, mnt->mnt_fsname);
! dfreedev(tmpname);
! } else {
! dfreemnt(mnt->mnt_dir, mnt);
! }
}
endmntent(mtabp);
exit(0);
--- 77,86 ----
}
while (mnt = getmntent(mtabp)) {
if (strcmp(mnt->mnt_type, MNTTYPE_IGNORE) == 0 ||
! strcmp(mnt->mnt_type, MNTTYPE_SWAP) == 0 ||
! strcmp(mnt->mnt_type, MNTTYPE_NFS) == 0)
continue;
! dfreemnt(mnt->mnt_dir, mnt);
}
endmntent(mtabp);
exit(0);
***************
*** 96,115 ****
for (i=1; i<argc; i++) {
struct mntent *mnt;
! if (stat(argv[i], &statb) < 0) {
! perror(argv[i]);
} else {
! if ((statb.st_mode & S_IFBLK) == S_IFBLK ||
! (statb.st_mode & S_IFCHR) == S_IFCHR) {
! dfreedev(argv[i]);
! } else {
! if ((mnt = getmntpt(argv[i])) != NULL)
! if (type &&
! strcmp(typestr, mnt->mnt_type)) {
! continue;
! }
! dfreemnt(argv[i], mnt);
}
}
}
exit(0);
--- 88,114 ----
for (i=1; i<argc; i++) {
struct mntent *mnt;
! if(fflag) {
! if (stat(argv[i], &statb) < 0)
! perror(argv[i]);
! else
! if ((statb.st_mode & S_IFBLK) == S_IFBLK ||
! (statb.st_mode & S_IFCHR) == S_IFCHR)
! dfreedev(argv[i]);
! else
! fprintf(stderr,
! "df: %s: Not a block or character special device\n",
! argv[i]);
} else {
! if((mnt = getmntpt(argv[i])) == NULL) {
! fprintf(stderr,
! "df: Can't find mount point for %s\n",
! argv[i]);
! continue;
}
+ if(type && strcmp(typestr, mnt->mnt_type))
+ continue;
+ dfreemnt(argv[i], mnt);
}
}
exit(0);
***************
*** 216,221 ****
--- 215,225 ----
return(NULL);
}
+ /* Since it is faster to scan mtab than to stat a file
+ on average (consdering the chance of contacting a hung
+ remote file server), scan all of mtab first to find the mount
+ point */
+
if ((mntp = setmntent(MOUNTED, "r")) == 0) {
perror(MOUNTED);
exit(1);
***************
*** 223,228 ****
--- 227,246 ----
mntsave = NULL;
while ((mnt = getmntent(mntp)) != 0) {
+ if(strcmp(mnt->mnt_dir, file))
+ continue;
+ mntsave = mntdup(mnt);
+ endmntent(mntp);
+ return mntsave;
+ }
+ endmntent(mntp);
+
+ if ((mntp = setmntent(MOUNTED, "r")) == 0) {
+ perror(MOUNTED);
+ exit(1);
+ }
+
+ while ((mnt = getmntent(mntp)) != 0) {
if (strcmp(mnt->mnt_type, MNTTYPE_IGNORE) == 0 ||
strcmp(mnt->mnt_type, MNTTYPE_SWAP) == 0)
continue;
***************
*** 229,234 ****
--- 247,253 ----
if ((stat(mnt->mnt_dir, &dirstat) >= 0) &&
(filestat.st_dev == dirstat.st_dev)) {
mntsave = mntdup(mnt);
+ break;
}
}
endmntent(mntp);
*** /source/bsd-4.3/common/man/man1/df.1 Fri Nov 17 01:35:09 1989
--- df.1 Wed Mar 7 17:47:21 1990
***************
*** 13,30 ****
[
.B \-i
] [
.B \-t
! mount-type ] [ filesystem ... ] [ file ... ]
.SH DESCRIPTION
.I Df
prints out the amount of free disk space
available on the specified
! .I filesystem,
! e.g. ``/dev/rp0a'',
! or on the filesystem in which the specified
.I file,
e.g. ``$HOME'',
! is contained.
If no file system is specified,
the free space on all of
the normally mounted file systems
--- 13,38 ----
[
.B \-i
] [
+ .B \-f
+ ] [
.B \-t
! mount-type ] [ file ... ]
.SH DESCRIPTION
.I Df
prints out the amount of free disk space
available on the specified
! .I filesystem.
! If the
! .B \-f
! flag is used,
! .I file
! can be a special device, e.g. ``/dev/ra0a''.
! If
! .B \-f
! is not used, the filesystem containing
.I file,
e.g. ``$HOME'',
! is used.
If no file system is specified,
the free space on all of
the normally mounted file systems
