[10960] in Athena Bugs
compiling on Solaris over NFS
daemon@ATHENA.MIT.EDU (John Carr)
Sun Sep 12 18:47:29 1993
To: jawetzel@MIT.EDU
Cc: bugs@MIT.EDU, bug-sparc@MIT.EDU
Date: Sun, 12 Sep 1993 18:47:22 EDT
From: John Carr <jfc@MIT.EDU>
The Sun assembler implicitly depends on an implementation of the NFS
protocol that is slightly different than the one we use on RTs and VAXes.
The incompatibility: traditional ftruncate() will not make a file longer.
SVR4 and new NFS (SunOS 4 and newer) implement a fcntl call to make a file
longer. But when this call is made to a VAX or RT server the size change
gets turned into a call to the kernel internal file truncate function, which
only makes files smaller.
This is the fix for the BSD NFS server, in case someone reading this wants
to build a fixed kernel. I'm not sure if the bmap call is needed.
*** /source/bsd-4.3/common/sys/ufs/ufs_vnodeops.c Wed Apr 15 11:07:51 1992
--- ufs_vnodeops.c Sun Sep 12 17:46:51 1993
***************
*** 598,603 ****
--- 597,613 ----
goto out;
}
itrunc(ip, vap->va_size);
+ /* Newer versions of NFS require that setattr with a size
+ larger than the current size extend the file. */
+ if (vap->va_size > ip->i_size) {
+ ip->i_size = vap->va_size;
+ /* Force allocation of the new block. */
+ #ifdef ibm032
+ bmap(ip, vap->va_size >> ip->i_fs->fs_bshift, B_READ, 0, 0);
+ #else
+ bmap(ip, vap->va_size / ip->i_fs->fs_bsize, B_READ, 0, 0);
+ #endif
+ }
}
/*
* Change file access or modified times.
