Commit Graph

159 Commits

Author SHA1 Message Date
Alan Cox
5786be7cc7 Introduce a field to struct vm_page for storing flags that are
synchronized by the lock on the object containing the page.

Transition PG_WANTED and PG_SWAPINPROG to use the new field,
eliminating the need for holding the page queues lock when setting
or clearing these flags.  Rename PG_WANTED and PG_SWAPINPROG to
VPO_WANTED and VPO_SWAPINPROG, respectively.

Eliminate the assertion that the page queues lock is held in
vm_page_io_finish().

Eliminate the acquisition and release of the page queues lock
around calls to vm_page_io_finish() in kern_sendfile() and
vfs_unbusy_pages().
2006-08-09 17:43:27 +00:00
Stephan Uphoff
6c1b7d16c2 Call vm_object_page_clean() with the object lock held.
Submitted by:	kensmith@
Reviewed by:	mohans@
MFC after:	6 days
2006-05-25 17:16:11 +00:00
Stephan Uphoff
dcf67e65d2 Do not set B_NOCACHE on buffers when releasing them in flushbuflist().
If B_NOCACHE is set the pages of vm backed buffers will be invalidated.
However clean buffers can be backed by dirty VM pages so invalidating them
can lead to data loss.
Add support for flush dirty page in the data invalidation function
of some network file systems.

This fixes data losses during vnode recycling (and other code paths
using invalbuf(*,V_SAVE,*,*)) for data written using an mmaped file.

Collaborative effort by: jhb@,mohans@,peter@,ps@,ups@
Reviewed by:	tegge@
MFC after:	7 days
2006-05-25 01:00:35 +00:00
Mohan Srinivasan
f1cdf89911 Changes to make the NFS client MP safe.
Thanks to Kris Kennaway for testing and sending lots of bugs my way.
2006-05-19 00:04:24 +00:00
Mohan Srinivasan
5ef7d50da5 Keep track of the number of in-progress async direct IO writes in the nfsnode.
Make fsync/close wait until all of these drain. Add a check to nfs_getpage() and
nfs_putpage().
2006-04-06 01:20:30 +00:00
Paul Saab
3834aac17e - Always return success from NFS strategy. nfs_doio(), in the
event of an error, does the right thing, in terms of setting
  the error flags in the buf header. That fixes a crash from
  bstrategy().
- Treat ETIMEDOUT as a "recoverable" error, causing the buffer
  to be re-dirtied. ETIMEDOUT can occur on soft mounts, when
  the number of retries are exceeded, and we don't want data loss
  in that case.

Submitted by:	Mohan Srinivasan
2005-11-21 19:23:46 +00:00
Paul Saab
865b5cc7fd Remove the NFS client rslock. The rslock was used to serialize
writers that want to extend the file. It was also used to serialize
readers that might want to read the last block of the file (with a
writer extending the file).  Now that we support vnode locking for
NFS, the rslock is unnecessary. Writers grab the exclusive vnode
lock before writing and readers grab the shared (or in some cases
the exclusive) lock.

Submitted by:	Mohan Srinivasan
2005-07-21 22:46:56 +00:00
Brian Feldman
6979a7592a Ifdef out the incomplete non-blocking IO implementation for NFS
pending discussion of how implementation would proceed.  Applications
like -lc_r expect select(3) to match the EAGAIN-status of IO
functions.

Approved by:	re
2005-06-16 15:43:17 +00:00
Brian Feldman
cc3149b1ea Fix a serious deadlock with the NFS client. Given a large enough
atomic write request, it can fill the buffer cache with the entirety
of that write in order to handle retries.  However, it never drops
the vnode lock, or else it wouldn't be atomic, so it ends up waiting
indefinitely for more buf memory that cannot be gotten as it has it
all, and it waits in an uncancellable state.

To fix this, hibufspace is exported and scaled to a reasonable
fraction.  This is used as the limit of how much of an atomic write
request by the NFS client will be handled asynchronously.  If the
request is larger than this, it will be turned into a synchronous
request which won't deadlock the system.  It's possible this value is
far off from what is required by some, so it shall be tunable as soon
as mount_nfs(8) learns of the new field.

The slowdown between an asynchronous and a synchronous write on NFS
appears to be on the order of 2x-4x.

General nod by:	gad
MFC after:	2 weeks
More testing:	wes
PR:		kern/79208
2005-06-10 23:50:41 +00:00
David Schultz
938838feb1 Don't brelse(bp) if bp is null. Also, eliminate some redundancy
and dead code.

Found by:	Coverity Prevent analysis tool
2005-03-18 21:23:32 +00:00
Jeff Roberson
c0f681c21d - The VI_DOOMED flag now signals the end of a vnode's relationship with
the filesystem.  Check that rather than VI_XLOCK.

Sponsored by:	Isilon Systems, Inc.
2005-03-13 12:14:56 +00:00
Poul-Henning Kamp
56dd36b1a6 Remove unused cred arg from nfs_vinvalbuf() and many bogus arguments
passed for it.
2005-01-24 12:31:06 +00:00
Poul-Henning Kamp
7c0745eeae Eliminate unused and unnecessary "cred" argument from vinvalbuf() 2005-01-14 07:33:51 +00:00
Warner Losh
c398230b64 /* -> /*- for license, minor formatting changes 2005-01-07 01:45:51 +00:00
Paul Saab
a7500bceb0 First cut of NFS direct IO support.
- NFS direct IO completely bypasses the buffer and page caches.
  If a file is open for direct IO all caching is disabled.
- Direct IO for Directories will be addressed later.
- 2 new NFS directio related sysctls are added. One is a knob to
  disable NFS direct IO completely (direct IO is enabled by default).
  The other is to disallow mmaped IO on a file that has at least one
  O_DIRECT open (see the comment in nfs_vnops.c for more details).
  The default is to allow mmaps on a file that has O_DIRECT opens.

Submitted by:	Mohan Srinivasan mohans at yahoo-inc dot com
Obtained from:	Yahoo!
2004-12-15 22:20:22 +00:00
Paul Saab
4342aac774 Store a hint in the nfsnode to detect sequential access of the file.
Kick off a readahead only when sequential access is detected.  This
eliminates wasteful readaheads in random file access.

Submitted by:	Mohan Srinivasan mohans at yahoo-inc dot com
Obtained from:	Yahoo!
2004-12-10 03:27:12 +00:00
Paul Saab
35ec46b7f2 Rewrite of the NFS client's reply handling. We now have NFS socket
upcalls which do RPC header parsing and match up the reply with the
request. NFS calls now sleep on the nfsreq structure. This enables
us to eliminate the NFS recvlock.

Submitted by:	Mohan Srinivasan mohans at yahoo-inc dot com
2004-12-06 21:11:15 +00:00
Paul Saab
ddc6c40075 2 fixes that improve on the consistency of the NFS client cache.
- Change the cached mtime to a 'struct timespec' from a
  time_t. Improving the precision of the cached mtime tightens up
  NFS' "close-to-open" consistency considerably.
- Always force an over-the-wire consistency check from nfs_open()
  (unless the file is marked modified). This further improves
  NFS' "close-to-open" consistency.

Submitted by:	Mohan Srinivasan mohans at yahoo-inc dot com
2004-12-06 19:18:00 +00:00
Paul Saab
d54d263a79 Serialize NFS vinvalbuf operations by acquiring/upgrading to the
vnode EXCLUSIVE lock. This prevents threads from adding pages to
the vnode while an invalidation is in progress, closing potential
races. In the bioread() path, callers acquire the SHARED vnode lock
- so while an invalidate was in progress, it was possible to fault
in new pages onto the vnode causing the invalidation to take a while
or fail. We saw these races at Yahoo! with very large files+heavy
concurrent access. Forcing an upgrade to EXCLUSIVE lock before doing
the invalidation closes all these races.

Submitted by:	Mohan Srinivasan mohans at yahoo-inc dot com
2004-12-06 18:52:28 +00:00
Jeff Roberson
b646893f0f - Eliminate the acquisition and release of the bqlock in bremfree() by
setting the B_REMFREE flag in the buf.  This is done to prevent lock order
   reversals with code that must call bremfree() with a local lock held.
   This also reduces overhead by removing two lock operations per buf for
   fsync() and similar.
 - Check for the B_REMFREE flag in brelse() and bqrelse() after the bqlock
   has been acquired so that we may remove ourself from the free-list.
 - Provide a bremfreef() function to immediately remove a buf from a
   free-list for use only by NFS.  This is done because the nfsclient code
   overloads the b_freelist queue for its own async. io queue.
 - Simplify the numfreebuffers accounting by removing a switch statement
   that executed the same code in every possible case.
 - getnewbuf() can encounter locked bufs on free-lists once Giant is removed.
   Remove a panic associated with this condition and delay asserts that
   inspect the buf until after it is locked.

Reviewed by:	phk
Sponsored by:	Isilon Systems, Inc.
2004-11-18 08:44:09 +00:00
Poul-Henning Kamp
6e67e2a710 Retire b_magic now, we have the bufobj containing the same hint. 2004-11-04 09:48:18 +00:00
Poul-Henning Kamp
b792bebeea Move the buffer method vector (buf->b_op) to the bufobj.
Extend it with a strategy method.

Add bufstrategy() which do the usual VOP_SPECSTRATEGY/VOP_STRATEGY
song and dance.

Rename ibwrite to bufwrite().

Move the two NFS buf_ops to more sensible places, add bufstrategy
to them.

Add inlines for bwrite() and bstrategy() which calls through
buf->b_bufobj->b_ops->b_{write,strategy}().

Replace almost all VOP_STRATEGY()/VOP_SPECSTRATEGY() calls with bstrategy().
2004-10-24 20:03:41 +00:00
Poul-Henning Kamp
494eb176e7 Add b_bufobj to struct buf which eventually will eliminate the need for b_vp.
Initialize b_bufobj for all buffers.

Make incore() and gbincore() take a bufobj instead of a vnode.

Make inmem() local to vfs_bio.c

Change a lot of VI_[UN]LOCK(bp->b_vp) to BO_[UN]LOCK(bp->b_bufobj)
also VI_MTX() to BO_MTX(),

Make buf_vlist_add() take a bufobj instead of a vnode.

Eliminate other uses of bp->b_vp where bp->b_bufobj will do.

Various minor polishing: remove "register", turn panic into KASSERT,
use new function declarations, TAILQ_FOREACH_SAFE() etc.
2004-10-22 08:47:20 +00:00
David Schultz
506d3e1bcc nfsclient/nfs_bio.c has a PHOLD() without a PRELE(). Neither should
be necessary here.  Also, use killproc() instead of psignal().
2004-10-01 05:01:41 +00:00
Poul-Henning Kamp
08dbd671ff Remove unused B_WRITEINPROG flag 2004-09-15 21:49:22 +00:00
Poul-Henning Kamp
35f134080f Explicitly pass vnode to nfs_doio() and mountpoint to nfs_asyncio(). 2004-09-07 08:56:43 +00:00
Alfred Perlstein
c713aaaeca NFS mobility PHASE I, II & III (phase VI, and V pending):
Rebind the client socket when we experience a timeout.  This fixes
the case where our IP changes for some reason.

Signal a VFS event when NFS transitions from up to down and vice
versa.

Add a placeholder vfs_sysctl where we will put status reporting
shortly.

Also:
Make down NFS mounts return EIO instead of EINTR when there is a
soft timeout or force unmount in progress.
2004-07-06 09:12:03 +00:00
Robert Watson
8950572050 Remove bad cookie vp kernel printf; while it does notify about an
interesting event, there's little or nothing the user can do about
it.
2004-06-17 00:15:37 +00:00
Alan Cox
5a32489377 Make vm_page's PG_ZERO flag immutable between the time of the page's
allocation and deallocation.  This flag's principal use is shortly after
allocation.  For such cases, clearing the flag is pointless.  The only
unusual use of PG_ZERO is in vfs_bio_clrbuf().  However, allocbuf() never
requests a prezeroed page.  So, vfs_bio_clrbuf() never sees a prezeroed
page.

Reviewed by:	tegge@
2004-05-06 05:03:23 +00:00
Peter Edwards
7c8ca9400e Let the NFS client notice a file's size changing as a modification.
This avoids presenting invalid data to the client's applications
when the file is modified, and then extended within the window of
the resolution of the modifcation timestamp.

Reviewed By:	iedowse
PR:		kern/64091
2004-04-14 23:23:55 +00:00
Warner Losh
2fcbca0d85 Remove advertising clause from University of California Regent's
license, per letter dated July 22, 1999 and email from Peter Wemm,
Alan Cox and Robert Watson.

Approved by: core, peter, alc, rwatson
2004-04-07 05:00:01 +00:00
Poul-Henning Kamp
4d453ef101 Properly vector all bwrite() and BUF_WRITE() calls through the same path
and s/BUF_WRITE()/bwrite()/ since it now does the same as bwrite().
2004-03-11 18:02:36 +00:00
John Baldwin
91d5354a2c Locking for the per-process resource limits structure.
- struct plimit includes a mutex to protect a reference count.  The plimit
  structure is treated similarly to struct ucred in that is is always copy
  on write, so having a reference to a structure is sufficient to read from
  it without needing a further lock.
- The proc lock protects the p_limit pointer and must be held while reading
  limits from a process to keep the limit structure from changing out from
  under you while reading from it.
- Various global limits that are ints are not protected by a lock since
  int writes are atomic on all the archs we support and thus a lock
  wouldn't buy us anything.
- All accesses to individual resource limits from a process are abstracted
  behind a simple lim_rlimit(), lim_max(), and lim_cur() API that return
  either an rlimit, or the current or max individual limit of the specified
  resource from a process.
- dosetrlimit() was renamed to kern_setrlimit() to match existing style of
  other similar syscall helper functions.
- The alpha OSF/1 compat layer no longer calls getrlimit() and setrlimit()
  (it didn't used the stackgap when it should have) but uses lim_rlimit()
  and kern_setrlimit() instead.
- The svr4 compat no longer uses the stackgap for resource limits calls,
  but uses lim_rlimit() and kern_setrlimit() instead.
- The ibcs2 compat no longer uses the stackgap for resource limits.  It
  also no longer uses the stackgap for accessing sysctl's for the
  ibcs2_sysconf() syscall but uses kernel_sysctl() instead.  As a result,
  ibcs2_sysconf() no longer needs Giant.
- The p_rlimit macro no longer exists.

Submitted by:	mtm (mostly, I only did a few cleanups and catchups)
Tested on:	i386
Compiled on:	alpha, amd64
2004-02-04 21:52:57 +00:00
Alfred Perlstein
90abe7f294 Use function pointers to remove the depenancy cross dependancy on nfs4
and the nfs3 client.  Also fix some bugs that happen to be causing crashes
in both v3 and v4 introduced by the v4 import.

Submitted by: Jim Rees <rees@umich.edu>
Approved by: re
2003-11-22 02:21:49 +00:00
Alfred Perlstein
1bf8720450 University of Michigan's Citi NFSv4 kernel client code.
Submitted by: Jim Rees <rees@umich.edu>
2003-11-14 20:54:10 +00:00
Poul-Henning Kamp
901b6327b1 Initialize bp->b_offset before calling VOP_STRATEGY().
Remove KASSERTS and panics with B_PHYS checks which no longer apply.
2003-10-18 11:14:29 +00:00
Poul-Henning Kamp
e6ad40bb11 We do not get B_PHYS buffers here anymore. /dev/drum is long gone. 2003-10-18 09:33:13 +00:00
Jeff Roberson
8b5905a47d - Remove the backtrace() call from the *_vinvalbuf() functions. Thanks to a
stack trace supplied by phk, I now understand what's going on here.  The
   check for VI_XLOCK stops us from calling vinvalbuf once the vnode has been
   partially torn down in vclean().  It is not clear that this would cause
   a problem.  Document this in nfs_bio.c, which is where the other two
   filesystems copied this code from.
2003-10-04 08:51:50 +00:00
Jeff Roberson
ce1fb23146 - Remove interlock protection around VI_XLOCK. The interlock is not
sufficient to guarantee that this race is not hit.  The XLOCK will likely
   have to be redesigned due to the way reference counting and mutexes work
   in FreeBSD.  We currently can not be guaranteed that xlock was not set
   and cleared while we were blocked on the interlock while waiting to check
   for XLOCK.  This would lead us to reference a vnode which was not the
   vnode we requested.
 - Add a backtrace() call inside of INVARIANTS in the hopes of finding out if
   this condition is ever hit.  It should not, since we should be retaining
   a reference to the vnode in these cases.  The reference would be sufficient
   to block recycling.
2003-09-19 23:37:49 +00:00
Alan Cox
aec774abec Lock the vm object when freeing a page. 2003-06-17 05:17:00 +00:00
Poul-Henning Kamp
17a1391990 The IO_NOWDRAIN and B_NOWDRAIN hacks are no longer needed to prevent
deadlocks with vnode backed md(4) devices because md now uses a
kthread to run the bio requests instead of doing it directly from
the bio down path.
2003-05-31 16:42:45 +00:00
Robert Watson
7042ac8cd7 This change grabs the vnode lock for NFS client vnodes when calling
VOP_SETATTR() or VOP_GETATTR(); without these locks (a) VFS_DEBUG_LOCKS
will panic, and (b) it may be possible to corrupt entries in the cached
vnode attributes in the nfsnode, since nfsnode attribute cache data is
also protected by the vnode lock.

Approved by:	re (jhb)
Pointed out by:	VFS_DEBUG_LOCKS
2003-05-15 21:12:08 +00:00
Jeff Roberson
7261f5f68e - Add a new 'flags' parameter to getblk().
- Define one flag GB_LOCK_NOWAIT that tells getblk() to pass the LK_NOWAIT
   flag to the initial BUF_LOCK().  This will eventually be used in cases
   were we want to use a buffer only if it is not currently in use.
 - Convert all consumers of the getblk() api to use this extra parameter.

Reviwed by:	arch
Not objected to by:	mckusick
2003-03-04 00:04:44 +00:00
Dag-Erling Smørgrav
521f364b80 More low-hanging fruit: kill caddr_t in calls to wakeup(9) / [mt]sleep(9). 2003-03-02 16:54:40 +00:00
Matthew Dillon
3a3d82ec0a Abstract-out the constants for the sequential heuristic.
No operational changes.

MFC after:	1 day
2002-12-28 20:37:50 +00:00
Jeff Roberson
8926aed697 - Lock access to the buf lists.
- Use vrefcnt() where appropriate.
 - Add some locking asserts.
2002-09-25 02:38:43 +00:00
Jeff Roberson
e6e370a7fe - Replace v_flag with v_iflag and v_vflag
- v_vflag is protected by the vnode lock and is used when synchronization
   with VOP calls is needed.
 - v_iflag is protected by interlock and is used for dealing with vnode
   management issues.  These flags include X/O LOCK, FREE, DOOMED, etc.
 - All accesses to v_iflag and v_vflag have either been locked or marked with
   mp_fixme's.
 - Many ASSERT_VOP_LOCKED calls have been added where the locking was not
   clear.
 - Many functions in vfs_subr.c were restructured to provide for stronger
   locking.

Idea stolen from:	BSD/OS
2002-08-04 10:29:36 +00:00
Alan Cox
e0c9fdb50e o Lock page queue accesses in nfs_getpages(). 2002-07-21 20:01:32 +00:00
Matthew Dillon
8e0619c6b0 Fix a bug nfs_write() related to ^C'ing during a file write on an
interruptable mount.  We were returning from inside the loop without
releasing the rslock.

Submitted by:	Mike Junk <junk@isilon.com>
MFC after:	3 days
2002-07-16 19:43:59 +00:00
Matthew Dillon
3d8f797ac1 Convert old style (type foo *)0 casts to NULLs
PR:		kern/40360
Requested by:	Hiten PAndya via direct email
2002-07-11 17:54:58 +00:00