* libamu/mount_fs.c (compute_nfs_attrcache_flags): cleanup the

code that sets the ac{reg,dir}{min,max} fields so it also sets the
appropriate nfs_args->flags such as MNT2_NFS_OPT_ACREGMIN.

* configure.in: check for nfs_args fields acregmax and acdirmax.

Update status of freebsd and openbsd.

diff --git a/ChangeLog b/ChangeLog
index d7e1727bd2c4acb5e13fcb03ccaa7d6f3842c942..ac1b4cc90b159f0a12893d499f6f2aa8cdd02b30 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,8 +1,15 @@
 2005-09-18  Erez Zadok  <ezk@cs.sunysb.edu>
 
+       * libamu/mount_fs.c (compute_nfs_attrcache_flags): cleanup the
+       code that sets the ac{reg,dir}{min,max} fields so it also sets the
+       appropriate nfs_args->flags such as MNT2_NFS_OPT_ACREGMIN.
+
+       * configure.in: check for nfs_args fields acregmax and acdirmax.
+
        * README.attrcache: new file documenting in detail OS bugs
        relating to attribute caching, which can affect Amd's reliability
        under heavy load.
+       Update status of freebsd and openbsd.
 
        * doc/Makefile.am: install README.attrcache file as attrache.txt
        file on am-utils Web site.

diff --git a/NEWS b/NEWS
index 97ba1847b3ae2d2881bf64cb9f8a08026c508c65..13db4ea30f3c3b7befa888c82b857e3a272e891d 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -37,6 +37,7 @@ XXX: Dan, document sun_map_syntax flag in more detail in am-utils.texi and
 
 - Bugs fixed:
        * abort with an error if yacc/lex programs not found
+       * properly turn off the attrcache in freebsd and openbsd
 
 Amd now understands a new log_option called "defaults" which is synonymous
 with "fatal,error,user,warning,info" (and is also what logging happens by

diff --git a/README.attrcache b/README.attrcache
index d290ce9a46ed2b25d56cc67bd63a002068dc1d9e..b167da3402dcc0be0dac71241cb99523084a3a28 100644 (file)
--- a/README.attrcache
+++ b/README.attrcache
@@ -50,15 +50,15 @@ resolution of only 1 second, which was not fine enough under heavy load.  We
 fixed this problem and switched to using a microsecond resolution mtime.
 
 After fixing this in Amd, we went on to verify that things work for other
-OSs.  When we got to FreeBSD 5.4 and NetBSD 2.0.2, we found out that they
-always cache directory entries, and there is no way to turn it off
-completely.  Specifically, if we set the ac{reg,dir}{min,max} fields in
-struct nfs_args all to zero, the kernel seems to cache the entries for a
-default number of seconds (something like 5-30 seconds).  On some OSs,
-setting these four fields to 0 turns off the attribute cache, but not on
-these two BSDs.  We were able to verify this using Amd and a script that
-exercises the interaction of the kernel's attrcache and Amd.  (If you're
-interested, the script can be made available.)
+OSs.  When we got to test certain BSDs, we found out that they always cache
+directory entries, and there is no way to turn it off completely.
+Specifically, if we set the ac{reg,dir}{min,max} fields in struct nfs_args
+all to zero, the kernel seems to cache the entries for a default number of
+seconds (something like 5-30 seconds).  On some OSs, setting these four
+fields to 0 turns off the attribute cache, but not on some BSDs.  We were
+able to verify this using Amd and a script that exercises the interaction of
+the kernel's attrcache and Amd.  (If you're interested, the script can be
+made available.)
 
 We then experimented by setting the ac{reg,dir}{min,max} fields in struct
 nfs_args all to 1, the smallest non-zero value we could.  When we ran the
@@ -76,7 +76,7 @@ configuration parameter called "broken_attrcache" which, if turned on, will
 set these nfs_args fields to 1 instead of 0.  I wish I didn't have to create
 such ugly workaround features in Amd, but I've got no choice.
 
-The near term solution is for FreeBSD to support a true 'noac' flag, which
+The near term solution is for every OS to support a true 'noac' flag, which
 can be added fairly easily.  This'd make Amd work reliably.
 
 The long term solution is to implement Autofs support for all OSs and to
@@ -95,12 +95,12 @@ any OS not listed is unknown as of the date at the top of this file.
 
 Sun Solaris 8 and 9 (10 probably works fine)
 Linux: 2.6.11 kernel (2.4.latest probably works fine)
+FreeBSD 5.4 and 6.0-SNAP001 (older versions probably work fine)
+OpenBSD 3.7 (older versions probably work fine)
 
 ** Vulnerable (don't support a proper "noac" flag):
 
 NetBSD 2.0.2 (older versions also probably affected)
-FreeBSD 5.4 (older versions also probably affected)
-OpenBSD 3.7 (older versions also probably affected)
 
 Note: NetBSD has promised to support a noac flag hopefully after 2.1.0 is
 released (maybe in 3.0 or 2.2).

diff --git a/configure.in b/configure.in
index ca04bdcdf99aa0688b1ff87a623fec0f8079f582..df416cce9f1c811a5c7d6e07b796299f6b447ffa 100644 (file)
--- a/configure.in
+++ b/configure.in
@@ -55,7 +55,7 @@ AH_BOTTOM([
 dnl
 dnl AC_CONFIG_AUX_DIR(m4)
 AC_PREREQ(2.52)
-AC_REVISION($Revision: 1.114 $)
+AC_REVISION($Revision: 1.115 $)
 AC_COPYRIGHT([Copyright (c) 1997-2005 Erez Zadok])
 dnl find out system type
 AC_MSG_NOTICE(*** SYSTEM TYPES ***)
@@ -866,7 +866,9 @@ AMU_CHECK_FIELD(xfs_args_t.fspec)
 AMU_CHECK_FIELD(struct fhstatus.fhs_fh)
 AMU_CHECK_FIELD(struct statfs.f_fstypename)
 AMU_CHECK_FIELD(nfs_args_t.acdirmin)
+AMU_CHECK_FIELD(nfs_args_t.acdirmax)
 AMU_CHECK_FIELD(nfs_args_t.acregmin)
+AMU_CHECK_FIELD(nfs_args_t.acregmax)
 AMU_CHECK_FIELD(nfs_args_t.bsize)
 AMU_CHECK_FIELD(nfs_args_t.fh_len)
 AMU_CHECK_FIELD(nfs_args_t.fhsize)

diff --git a/libamu/mount_fs.c b/libamu/mount_fs.c
index 29d68682460a57c24a8ea88874773054dfa1bbe3..a6f97a13646372faccd2e8758760ea3466edab9a 100644 (file)
--- a/libamu/mount_fs.c
+++ b/libamu/mount_fs.c
@@ -349,58 +349,73 @@ compute_nfs_attrcache_flags(nfs_args_t *nap, mntent_t *mntp)
   acval = hasmntval(mntp, MNTTAB_OPT_ACTIMEO); /* attr cache timeout (sec) */
 #endif /* MNTTAB_OPT_ACTIMEO */
 
-  if (acval) {
+  /*** acregmin ***/
 #ifdef HAVE_NFS_ARGS_T_ACREGMIN
+  if (acval) {
     nap->acregmin = acval;     /* min ac timeout for reg files (sec) */
-    nap->acregmax = acval;     /* max ac timeout for reg files (sec) */
-#endif /* HAVE_NFS_ARGS_T_ACREGMIN */
-#ifdef HAVE_NFS_ARGS_T_ACDIRMIN
-    nap->acdirmin = acval;     /* min ac timeout for dirs (sec) */
-    nap->acdirmax = acval;     /* max ac timeout for dirs (sec) */
-#endif /* HAVE_NFS_ARGS_T_ACDIRMIN */
   } else {
-#ifdef HAVE_NFS_ARGS_T_ACREGMIN
 # ifdef MNTTAB_OPT_ACREGMIN
     nap->acregmin = hasmntval(mntp, MNTTAB_OPT_ACREGMIN);
 # else /* not MNTTAB_OPT_ACREGMIN */
     nap->acregmin = 0;
 # endif /* not MNTTAB_OPT_ACREGMIN */
+  }
+  /* set this flag, because if we got here, then we changed acregmin */
+# ifdef MNT2_NFS_OPT_ACREGMIN
+  nap->flags |= MNT2_NFS_OPT_ACREGMIN;
+# endif /* MNT2_NFS_OPT_ACREGMIN */
+#endif /* HAVE_NFS_ARGS_T_ACREGMIN */
+
+  /*** acregmax ***/
+#ifdef HAVE_NFS_ARGS_T_ACREGMAX
+  if (acval) {
+    nap->acregmax = acval;     /* min ac timeout for reg files (sec) */
+  } else {
 # ifdef MNTTAB_OPT_ACREGMAX
     nap->acregmax = hasmntval(mntp, MNTTAB_OPT_ACREGMAX);
 # else /* not MNTTAB_OPT_ACREGMAX */
     nap->acregmax = 0;
 # endif /* not MNTTAB_OPT_ACREGMAX */
-#endif /* HAVE_NFS_ARGS_T_ACREGMIN */
+  }
+  /* set this flag, because if we got here, then we changed acregmax */
+# ifdef MNT2_NFS_OPT_ACREGMAX
+  nap->flags |= MNT2_NFS_OPT_ACREGMAX;
+# endif /* MNT2_NFS_OPT_ACREGMAX */
+#endif /* HAVE_NFS_ARGS_T_ACREGMAX */
+
+  /*** acdirmin ***/
 #ifdef HAVE_NFS_ARGS_T_ACDIRMIN
+  if (acval) {
+    nap->acdirmin = acval;     /* min ac timeout for reg files (sec) */
+  } else {
 # ifdef MNTTAB_OPT_ACDIRMIN
     nap->acdirmin = hasmntval(mntp, MNTTAB_OPT_ACDIRMIN);
 # else /* not MNTTAB_OPT_ACDIRMIN */
     nap->acdirmin = 0;
 # endif /* not MNTTAB_OPT_ACDIRMIN */
+  }
+  /* set this flag, because if we got here, then we changed acdirmin */
+# ifdef MNT2_NFS_OPT_ACDIRMIN
+  nap->flags |= MNT2_NFS_OPT_ACDIRMIN;
+# endif /* MNT2_NFS_OPT_ACDIRMIN */
+#endif /* HAVE_NFS_ARGS_T_ACDIRMIN */
+
+  /*** acdirmax ***/
+#ifdef HAVE_NFS_ARGS_T_ACDIRMAX
+  if (acval) {
+    nap->acdirmax = acval;     /* min ac timeout for reg files (sec) */
+  } else {
 # ifdef MNTTAB_OPT_ACDIRMAX
     nap->acdirmax = hasmntval(mntp, MNTTAB_OPT_ACDIRMAX);
 # else /* not MNTTAB_OPT_ACDIRMAX */
     nap->acdirmax = 0;
 # endif /* not MNTTAB_OPT_ACDIRMAX */
-#endif /* HAVE_NFS_ARGS_T_ACDIRMIN */
-  } /* end of "if (acval)" statement */
-
-#ifdef MNT2_NFS_OPT_ACREGMIN
-  if (nap->acregmin)
-    nap->flags |= MNT2_NFS_OPT_ACREGMIN;
-#endif /* MNT2_NFS_OPT_ACREGMIN */
-#ifdef MNT2_NFS_OPT_ACREGMAX
-  if (nap->acregmax)
-    nap->flags |= MNT2_NFS_OPT_ACREGMAX;
-#endif /* MNT2_NFS_OPT_ACREGMAX */
-#ifdef MNT2_NFS_OPT_ACDIRMIN
-  if (nap->acdirmin)
-    nap->flags |= MNT2_NFS_OPT_ACDIRMIN;
-#endif /* MNT2_NFS_OPT_ACDIRMIN */
-#ifdef MNT2_NFS_OPT_ACDIRMAX
-  if (nap->acdirmax)
-    nap->flags |= MNT2_NFS_OPT_ACDIRMAX;
-#endif /* MNT2_NFS_OPT_ACDIRMAX */
+  }
+  /* set this flag, because if we got here, then we changed acdirmax */
+# ifdef MNT2_NFS_OPT_ACDIRMAX
+  nap->flags |= MNT2_NFS_OPT_ACDIRMAX;
+# endif /* MNT2_NFS_OPT_ACDIRMAX */
+#endif /* HAVE_NFS_ARGS_T_ACDIRMAX */
 
 #ifdef MNTTAB_OPT_NOAC         /* don't cache attributes */
   if (amu_hasmntopt(mntp, MNTTAB_OPT_NOAC) != NULL)