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Internet Message Format | 1991-02-05 | 16.9 KB

From: jgd@Dixie.Com (John G. DeArmond) Newsgroups: comp.sources.misc Subject: v16i092: Ichk - The inode/filesystem checker (Fixed), Patch1 Message-ID: <1991Feb3.213938.186@sparky.IMD.Sterling.COM> Date: 3 Feb 91 21:39:38 GMT Approved: kent@sparky.imd.sterling.com X-Checksum-Snefru: eccb4c41 c3bb6bed df7d534a c1c7d9ab Submitted-by: jgd@Dixie.Com (John G. DeArmond) Posting-number: Volume 16, Issue 92 Archive-name: ichk/patch1 Patch-To: ichk: Volume 16, Issue 75 Oops! Someone pointed out that the posted version of Ichk I placed in comp.sources.misc and alt.sources contained a fatal bug. Mea Culpa :-( I'm so embarrassed! Enclosed is a revised version of Ichk that does something other than eat CPU time. Please replace the version of Ichk.c in your archive with this version. I have also included a duplicate copy of the instruction file, Ichk.txt. John ------------------------------ cut here ------------------------------------- #!/bin/sh # This is a shell archive (shar 3.11) # made 02/01/1991 09:07 UTC by jgd@rsiatl # Source directory /usr/local/tools/ichk # # existing files WILL be overwritten # # This shar contains: # length mode name # ------ ---------- ------------------------------------------ # 405 -rw-r--r-- README # 6095 -r--r--r-- ichk.c # 7310 -rw-rw---- ichk.txt # touch 2>&1 | fgrep '[-amc]' > /tmp/s3_touch$$ if [ -s /tmp/s3_touch$$ ] then TOUCH=can else TOUCH=cannot fi rm -f /tmp/s3_touch$$ # ============= README ============== echo "x - extracting README (Text)" sed 's/^X//' << 'SHAR_EOF' > README && XOops! X XSomeone pointed out that the posted version of Ichk I placed in Xcomp.sources.misc and alt.sources contained a fatal bug. Mea Culpa :-( XI'm so embarrassed! Enclosed is a revised version of Ichk that does Xsomething other than eating CPU time. Please replace the version of XIchk.c in your archive with this version. I have also included a duplicate Xcopy of the instruction file, Ichk.txt. X XJohn X SHAR_EOF chmod 0644 README || echo "restore of README fails" if [ $TOUCH = can ] then touch -am 0201040691 README fi set `wc -c README`;Wc_c=$1 if test "$Wc_c" != "405" then echo original size 405, current size $Wc_c;fi # ============= ichk.c ============== echo "x - extracting ichk.c (Text)" sed 's/^X//' << 'SHAR_EOF' > ichk.c && X X#ifdef SCCSID Xstatic sccsid[] = "@(#) ichk.c 1.5 91/02/01 04:01:47"; X#endif X X#include <stdio.h> X#include <sys/types.h> X#include <sys/statfs.h> X#include <sys/signal.h> X X/* this program checks vital parameters on the file system it is invoked X** against and when a problem is found, runs a specified program that X** remedies the problem (hopefully). X** X** This program must be setuid root and/or run from root X*/ X Xstruct statfs buf; Xlong inode_trigger = 200L; Xlong block_trigger = 1000L; Xlong ratio = 5L; Xint i; Xchar file_sys[256]; Xchar action[256]; Xchar c; Xint verbose=0; Xint snooze=10; Xlong i_ratio; Xint talk=0; X Xextern int optind; Xextern char *optarg; Xextern int errno; Xextern void usage(); Xextern void take_action(); Xextern char *decimalize(); Xextern void terminator(); X Xmain(argc,argv) Xint argc; Xchar **argv; X{ X X#ifdef DAEMON X /* do NOT do this if you run ichk from init. Init gets real pissed */ X /* with processes that try to daemonize themselves */ X if (fork()) X exit(0); X#endif X X setpgrp(); /* make us a little bit independent */ X X X signal(SIGTERM,terminator); X signal(SIGINT,terminator); X signal(SIGHUP,terminator); X X action[0] = '\0'; X X if (argc < 2) { X usage(); X } X X if ( setuid(0) ) { X fprintf(stderr,"*** ERROR: Setuid root failed"); X sleep(5); X exit(2); X } X X if ( setgid(0) ) { X fprintf(stderr,"*** ERROR: Setgid root failed"); X sleep(5); X exit(3); X } X X while ( (c = getopt(argc, argv, "a:b:i:r:s:vt")) != -1 ) { X switch (c) { X case 'a': /* specifies the action to take */ X strcpy(action,optarg); X break; X case 'b': /* low block count threshold */ X block_trigger = atol(optarg); X if (block_trigger == 0L) X usage(); X break; X case 'i': X inode_trigger=atol(optarg); X if (inode_trigger == 0L) X usage(); X break; X case 'r': X ratio=atol(optarg); X if (ratio == 0L) X usage(); X break; X case 'v': X verbose=1; X break; X case 's': X snooze = atoi(optarg); X if (snooze == 0 ) X usage(); X break; X case 't': /* give a report only or (t)alk */ X talk=1; X break; X case '?': X usage(); X break; X } X } X if (talk) verbose = 0; X X strcpy(file_sys,argv[optind]); X X if (verbose) X printf("pid = %d\n", getpid()); X X errno=0; X if ( statfs(file_sys, &buf, sizeof(struct statfs), 0) == -1) { X fprintf(stderr,"*** ERROR: statfs() failed, errno = %d\n",errno); X fprintf(stderr,"file_sys = <%s>\n", file_sys); X fprintf(stderr,"sizeof(struct statfs) = %d \n", sizeof(struct statfs)); X sleep(10); /* keeps init happy */ X exit(4); X } X X if (talk) { X printf("%s %ld %ld ", buf.f_fname, buf.f_blocks, buf.f_bfree); X printf("%ld %ld %s\n", buf.f_files, buf.f_ffree, X decimalize((buf.f_bfree*10L) / (buf.f_ffree))); X exit(0); X X } X X X if (verbose) { X printf("File system type = %d\n", buf.f_fstyp); X printf("Total blocks = %ld\n", buf.f_blocks); X printf("Free blocks = %ld\n", buf.f_bfree); X printf("Total inodes = %ld\n", buf.f_files); X printf("Free inodes = %ld\n", buf.f_ffree); X printf("Volume name = %s\n", buf.f_fname); X } X X while (1) { X X if (statfs(file_sys, &buf, sizeof(struct statfs), 0) == -1) { X /* maybe the problem will go away, nothing to do anyway*/ X sleep(10); X continue; X } X X i_ratio = (buf.f_bfree*10L) / buf.f_ffree; X /* preserving one decimal place of rounding */ X X /* ratio of blocks to inodes will go UP when the system starts losing X inodes */ X if ( i_ratio >= (ratio*10L) ) { X if (verbose) X printf("Block to Inode ratio %s is too high\n", decimalize(i_ratio)); X take_action("ratio"); X goto slumber; X } else { X if (verbose) X printf("Block to Inode ratio is %s\n", decimalize(i_ratio)); X } X X if (buf.f_ffree < inode_trigger) { X if (verbose) X printf("Inodes low threshold triggered at %ld inodes\n", X buf.f_ffree); X take_action("inode"); X goto slumber; X } else { X if (verbose) X printf("Inodes = %ld\n", X buf.f_ffree); X } X X if (buf.f_bfree < block_trigger) { X if (verbose) X printf("Blocks low threshold triggered at %ld blocks\n", X buf.f_bfree); X take_action("block"); X goto slumber; X } else { X if (verbose) X printf("Blocks = %ld\n", X buf.f_bfree); X } X X slumber: X sleep(snooze); X X } /* for (;;) */ X X /* NOTREACHED */ X sleep(5); X exit(0); X} /* main */ X Xvoid Xtake_action(x) Xchar x[]; /* problem to be remedied */ X{ X char buff[256]; X X if (!strlen(action)) X return; X X sprintf(buff,"%s %s %s", action, file_sys, x); X if (verbose) X printf("Action taken: Command line to system()\n\t%s\n",buff); X X system(buff); X return; X} X Xchar * Xdecimalize(x) Xlong x; X{ X static char buff[256]; X int len; X X memset(buff,'\0',256); X X sprintf(buff,"%ld", x); X len = strlen(buff); X X buff[len] = buff[len-1]; /* move last char over one to the right*/ X buff[len-1] = '.'; X X return(buff); X} X Xvoid Xusage() X{ X X fprintf(stderr, X "\nUsage:\n\nichk <-a action>\n <-i inode_trig>\n <-r ratio>\n <-v>\n"); X fprintf(stderr, X " <-s sleep_secs>\n <-b block_count_trigger>\n <-t>\n file_system_name\n"); X fprintf(stderr, X "\nThe defaults are %ld inodes, %ld:1 block_to_inodes_ratio,\n", X inode_trigger, ratio); X fprintf(stderr, X "%ld blocks, action = nothing and %d seconds between checks.\n", X block_trigger, snooze); X fprintf(stderr, X "\nWhen the <action> program is invoked, the program is passed the\n"); X fprintf(stderr, X "following arguments:\nargv[1] == the file system\nargv[2] == the problem\n"); X fprintf(stderr, X "\nargv[2] can be:\nratio = ratio of blocks to inodes exceeded.\n"); X fprintf(stderr, X "inode = the low inode threshold exceeded.\n"); X fprintf(stderr, X "block = the low block threshold exceeded.\n"); X fprintf(stderr, X "If the -t (talk) flag is specified, all other options are ignored and\n"); X fprintf(stderr, X "ichk reports the status of the file system in the form:\n fs_name "); X fprintf(stderr, X "block_count blocks_free inode_count inodes_free ratio_blocks_2_inodes\n"); X X sleep(5); X exit(1); X} Xvoid Xterminator(x) Xint x; X{ X fprintf(stderr,"Signal caught: ichk going down on signal %d\n", x); X exit(0); X} SHAR_EOF chmod 0444 ichk.c || echo "restore of ichk.c fails" if [ $TOUCH = can ] then touch -am 0201040191 ichk.c fi set `wc -c ichk.c`;Wc_c=$1 if test "$Wc_c" != "6095" then echo original size 6095, current size $Wc_c;fi # ============= ichk.txt ============== echo "x - extracting ichk.txt (Text)" sed 's/^X//' << 'SHAR_EOF' > ichk.txt && X X Ichk - The Inode Checker. X Version 1.0 01/13/91 X XIchk is designed to watch the condition of a file system and if specified Xbounds are exceeded, to fire off a corrective process or script. Ichk is Xdesigned to be run from init(1) as a respawned job. The program was originally Xwritten to address the famous SysV inode bug that typically manifests Xitself in conjunction with news but it has many more uses. X XWhen ichk is invoked, it uses statfs(2) to collect statistics on the Xfile system specified in the command line. It then compares the number Xof free blocks, the number of free inodes and the ratio of free blocks Xto free inodes to specified values or defaults. If any limits are Xexceeded, a child process is started via system(3S). X XThe child process is passed the name of the file system and a keyword Xthat specifies the problem to be addresses. Typical action would be in Xthe case of low inodes or increasing blocks to inodes would be to unmount Xthe affected partition and fsck it and remount it. Typical action for Xlow blocks might be to run an emergency expire on the news partition. X XI have observed that when the inode bug is manifesting itself, the Xfirst indication is that as the inode count decreases rapidly, the Xratio of blocks to inodes increases. Thus, it is possible to catch the Xproblem before the inodes run completely out and data is dropped. X XAfter any corrective action is run or if there is no problem, the daemon Xsleeps for a designated period and then repeats the process. Here at XDixie Communications, ichk is designated to examine things once a Xminute. X XIchk also has an information, or "talk" mode that only reports statistics Xand then exits. This makes ichk useful for reporting file system information Xto a corrective script and is somewhat easier and less resource intensive Xto use than df. X XIchk is equipped with sleeps of 5 seconds at all exit points which should Xkeep init happy in case something makes the program exit prematurely. XNote that if ichk is killed while a corrective process is running, ichk Xmakes no attempt to kill the child. It is assumed that the child may Xbe executing actions that would be destructive if not run to Xcompletion. XTherefore if you want to kill the child process, you'll have to do it Xmanually. X XOPTIONS X XIchk has several options that may be specified at invocation. Most options Xhave reasonable defaults. Following are listed each of the options and Xan explanation of each. X X XUsage: X ichk <-a action> <-i inode_trig> <-r ratio> <-v> <-s sleep_secs> X <-b block_count_trigger> <-t> file_system_name X X X-a action Specifies the process or script to be invoked in the event a X limit is exceeded. Multiple options to the child process should X be quoted to keep the shell happy. When the child process is invoked, X it receives all commands specified with the -a option plus the X name of the affected file system and a keyword that specifies the X problem. The keywords are: X X ratio = ratio of blocks to inodes exceeded. X inode = the low inode threshold exceeded. X block = the low block threshold exceeded. X X The default is to do nothing; ie, there is no default command X specified and ichk will do nothing without a specification. X X-i inode_trigger Specifies the low inode trigger point. When the free X inode count is found to fall below this point, the <action> child X process is invoked. If -i is not specified, then the default of 200 X inodes is used. X X-r ratio Specifies the integer ratio of blocks to inodes above which the X <action> child process is invoked. The default value is 5:1. X X-s seconds Specifies how many seconds ichk waits between checks of the X filesystem. The default is 10 seconds. X X-b block_count Specifies the minimum block count below which the <action> X child process is invoked. The default is 1000 blocks. X X-t Specifies the "talk mode" which reports the statistics of the file system X and then exits. The statistics are presented in a format easily used X in script files. The format is: X X fs_name block_count blocks_free inode_count inodes_free \ X ratio_blocks_2_inodes X X-v Specifies verbose mode. Quite a bit of information is returned in X verbose mode so it is suggested that it only be used for debugging X purposes. X Xfilesystem Specifies the filesystem to examine. This filesystem must X be mounted. The FM is somewhat vague as to how the statfs(2) call X works but at least with Interactive Unix, the call works correctly X whether the actual mount point or a file on the file system is X specified. X X XOPERATIONS X XBecause most any corrective action requires root privileges, this program Xshould be run as root. Because it provides a tremendous opportunity for a Xsecurity breach, the permission mask should be set as follows: X X-r-s------ 1 root root 6644 Jan 13 13:12 /etc/ichk X Xor 04500. X XThe typical usage is for ichk to be run from init(1). A typical inittab Xentry is as follows: X Xk2:2345:respawn:/etc/ichk -a /usr/local/news/bin/Inodes -s 60 /news >/dev/null 2>&1 X XThis line uses the default values for inodes, blocks and inode to blocks ratio Xand it checks the /news filesystem every 60 seconds. If a problem is Xfound, then the Inodes script is run. X XThe script /usr/local/news/bin/Inodes or whatever your protective program Xis named must also be owned by root and must have the permissions 0500 in Xorder to prevent a security hole. It is also suggested that the Xdirectory that the script is in be set so that users cannot access it. X XA copy of a typical Inodes script is included with this package. It Xshould examine the specified problem and take action as appropriate. X XThough most people will want to run ichk from init(1) because it makes it Xso easy to manage, there are provisions to run ichk as a true daemon. If Xyou want to run ichk as a daemon, for instance as from /etc/rc2.d/xxx, Xsimply specify -DDAEMON on the compile line in the makefile and remake Xichk. It will then daemonize itself when invoked. X XOTHER USES X XThough ichk has its primary use with news, there are other uses. For Xexample, if you configure your system such that all log files are kept Xon a separate partition, you can have ichk monitor the free blocks on Xthe partition and fire off cleanup scripts to delete old or obese files. X XAnother use is to run ichk -t periodically against the news partition and Xdirect the output to a log file. In this manner, you can collect use Xstatistics and in particular, monitor the block to inode ratio. Since Xthe needed block to inode ratio for news is typically much different Xthan that for normal file systems, you can quickly determine what Xthe optimum ratio is. X XCOPYRIGHTS, ETC. X XThis package is copyright 1991 John De Armond, All rights reserved. You Xmay freely copy, modify and use this program provided that if you modify Xit, you do not distribute it as ichk. If you distribute ichk, you must Xdistribute it intact with the source and documentation. You may not Xsell it or claim you wrote it. I specifically disclaim any association Xwith the GNU General Public Virus, er, license. I also specifically Xdisclaim any warranty of any kind. X XAny feedback, errors, bugs, nicely worded gripes :-) or other comments Xwelcome. X XJohn De Armond Xjgd@dixie.com X SHAR_EOF chmod 0660 ichk.txt || echo "restore of ichk.txt fails" if [ $TOUCH = can ] then touch -am 0201040291 ichk.txt fi set `wc -c ichk.txt`;Wc_c=$1 if test "$Wc_c" != "7310" then echo original size 7310, current size $Wc_c;fi exit 0 -- John De Armond, WD4OQC | "Purveyors of speed to the Trade" (tm) Rapid Deployment System, Inc. | Home of the Nidgets (tm) Marietta, Ga | {emory,uunet}!rsiatl!jgd |"Politically InCorrect.. And damn proud of it exit 0 # Just in case... -- Kent Landfield INTERNET: kent@sparky.IMD.Sterling.COM Sterling Software, IMD UUCP: uunet!sparky!kent Phone: (402) 291-8300 FAX: (402) 291-4362 Please send comp.sources.misc-related mail to kent@uunet.uu.net.