UVM was written by chuck cranor <chuck@maria.wustl.edu>, with some
minor portions derived from the old Mach code. i provided some help
getting swap and paging working, and other bug fixes/ideas. chuck
silvers <chuq@chuq.com> also provided some other fixes.
this is the rest of the MI portion changes.
this will be KNF'd shortly. :-)
the directory cache as translation table. See nfs_subs.c for comments.
Makes the code a bit more complex to look at than I would have liked,
but doesn't affect the speed of the default behavior.
* Optimize caching behavior a bit when buffers are invalidated.
* Save some RPCs in readdir operations by not bothering if there is
a small amount left to do to fill the buffer. It'll be done in the
next RPC with a larger chunk anyway. Wastes a bit of buffer space
but is faster.
* Make n_vattr an allocated vattr struct. This avoids nfsnode bloat,
and is friendlier to the malloc routines.
directory cookie that may be thrown back at us from userspace, up
to a size limit. Fixes double entry problem.
* Split flags for internal and external use in the NFS mount structure.
* Fix some buffer structure fields that weren're being used correctly.
* Fix missing directory cache inval call in nfs_open.
* Limit on NFS_DIRBLKSIZ no longer needed, bumped to the more reasonable
value of 8k.
* Various other things that I forget, all related to the dir caching
somehow, though.
From Olaf Seibert <rhialto@polder.ubc.kun.nl> (PR 3687)
* Make an attempt to check the maximum filesize before attempting
a write to the server, as write RPCs will typically happen
asynchronously, and the process will not see the error.
Fixes problems with unexpectly truncated files at 4G
* Pass up errors in nfs_writerpc correctly
In readdirplus, don't keep such pointers but store the file attributes
in a variable instead until they are needed. Change nfsm_loadattr*
a bit so it can accept a direct pointer to an nfs_fattr structure.
architectures), truncate them intelligently instead.
The truncation is done centralized in vnode_pager.c.
This prevents from wrap-over effects when parts of large (>2^32 byte) files
are mmapped.
Don't allow to mmap above the numerical range of vm_offset_t.
This is considered a temporary solution until the vm system handles the
object sizes/offsets more cleanly.
date: 1996/07/23 17:14:46; author: donn; state: Exp; lines: +6 -4
Be sure to push out the last page of the file before truncating it.
date: 1996/10/14 22:41:20; author: donn; state: Exp; lines: +2 -2
From Chris: Nfs_link() called vput() on the wrong vnode when aborting
from a cross-device link, which could (and did) lead to crashes.
date: 1996/10/24 16:43:43; author: pjd; state: Exp; lines: +6 -2
Return EOPNOTSUPP when trying to do a setattr with flags.
===
Also (from BSDI too, but the RCS message did not quite describe the change
to this particular file well): move the EROFS a bit further down to
let VOP_ACCESS do it's work and return an 'expected' error value to
a possible layered filesystem.
Improve the queuing algorithms used by NFS' asynchronous i/o. The
existing mechanism uses a global queue for some buffers and the
vp->b_dirtyblkhd queue for others. This turns sequential writes into
randomly ordered writes to the server, affecting both read and write
performance. The existing mechanism also copes badly with hung
servers, tending to block accesses to other servers when all the iods
are waiting for a hung server.
The new mechanism uses a queue for each mount point. All asynchronous
i/o goes through this queue which preserves the ordering of requests.
A simple mechanism ensures that the iods are shared out fairly between
active mount points.
Reviewed/integrated/approved by Frank van der Linden <fvdl@netbsd.org>
struct member cn_nameptr 'const', since they should never be used to
modify the path name. (Only the pathname buffer, cn_pnbuf, should be
modified.) Propagate the const poisoning to code that uses the namei
and componentname structs.
* Make 2nd and 3rd args timespecs, not timevals.
* Consistently pass a Boolean as the 4th arg (except in LFS).
Also, fix ffs_update() and lfs_update() to actually change the nsec fields.
* Change the argument names to vop_link so they actually make sense.
* Implement vop_link and vop_symlink for all file systems, so they do proper
cleanup.
* Require the file system to decide whether or not linking and unlinking of
directories is allowed, and disable it for all current file systems.
each entry, and read them out in nfs_readdir().
Caveat: our current caching method for directory blocks uses the
server offset of the first directory entry as an identifier, so a
Linux emulation getdirentries() will wind up retrieving one block from
the NFS server for each directory entry, unnecessarily thrashing the
cache. The situation isn't as bad for other emulations.
Instead of getblk(), we need to write a routine to scan each cache
block associated with vp to find a cookie that matches at some
directory entry. Some later time.
(1) it's unnecessary
(2) it causes machines to hang (yup!)
(3) it'd be gone in a few days anyway (it'd been yanked out
of 4.4-Lite by macklem long ago)
It was only there because macklem couldn't originally decide if things
should be locked, or not...
Remove comment talking about nfsiomaps that we don't have.
Always use credentials that are in the buffer header, in stead of trying
to get them from pageproc, which may once have been necessary to push pages
to swap (cannot imaging anyone having exercised this over NFS though).
John Woods, jfwfrom: @ksr.com. also, fixes the following problems:
the va_gen field is in a similar position
(Suns are going to be reporting the change-date microseconds as their
"generation"), I've supplied my own set of diffs below for your inspection.
Note these aren't even compiled, but they're pretty similar to what I had
to do to our older version of OSF/1 here. (There's also an unrelated change
supplied for xdr_subs.h; the pointer types supplied to the fxdr_time() and
txdr_time() macros are not, in fact, both struct timevals. That turns out
to be one of many tips-of-the-iceberg facing those porting the (old) Berkeley
NFS code to 64-bit machines...)
sommerfe