Commit Graph

137 Commits

Author SHA1 Message Date
Robert Watson
5e3f7694b1 Replace custom file descriptor array sleep lock constructed using a mutex
and flags with an sxlock.  This leads to a significant and measurable
performance improvement as a result of access to shared locking for
frequent lookup operations, reduced general overhead, and reduced overhead
in the event of contention.  All of these are imported for threaded
applications where simultaneous access to a shared file descriptor array
occurs frequently.  Kris has reported 2x-4x transaction rate improvements
on 8-core MySQL benchmarks; smaller improvements can be expected for many
workloads as a result of reduced overhead.

- Generally eliminate the distinction between "fast" and regular
  acquisisition of the filedesc lock; the plan is that they will now all
  be fast.  Change all locking instances to either shared or exclusive
  locks.

- Correct a bug (pointed out by kib) in fdfree() where previously msleep()
  was called without the mutex held; sx_sleep() is now always called with
  the sxlock held exclusively.

- Universally hold the struct file lock over changes to struct file,
  rather than the filedesc lock or no lock.  Always update the f_ops
  field last. A further memory barrier is required here in the future
  (discussed with jhb).

- Improve locking and reference management in linux_at(), which fails to
  properly acquire vnode references before using vnode pointers.  Annotate
  improper use of vn_fullpath(), which will be replaced at a future date.

In fcntl(), we conservatively acquire an exclusive lock, even though in
some cases a shared lock may be sufficient, which should be revisited.
The dropping of the filedesc lock in fdgrowtable() is no longer required
as the sxlock can be held over the sleep operation; we should consider
removing that (pointed out by attilio).

Tested by:	kris
Discussed with:	jhb, kris, attilio, jeff
2007-04-04 09:11:34 +00:00
Tor Egge
61b9d89ff0 Make insmntque() externally visibile and allow it to fail (e.g. during
late stages of unmount).  On failure, the vnode is recycled.

Add insmntque1(), to allow for file system specific cleanup when
recycling vnode on failure.

Change getnewvnode() to no longer call insmntque().  Previously,
embryonic vnodes were put onto the list of vnode belonging to a file
system, which is unsafe for a file system marked MPSAFE.

Change vfs_hash_insert() to no longer lock the vnode.  The caller now
has that responsibility.

Change most file systems to lock the vnode and call insmntque() or
insmntque1() after a new vnode has been sufficiently setup.  Handle
failed insmntque*() calls by propagating errors to callers, possibly
after some file system specific cleanup.

Approved by:	re (kensmith)
Reviewed by:	kib
In collaboration with:	kib
2007-03-13 01:50:27 +00:00
Kelly Yancey
c9ad8a67af Restore the ability to mount procfs and fdescfs filesystems via the
mount(2) system call:

  * Add cmount hook to fdescfs and pseudofs (and, by extension, procfs and
    linprocfs).  This (mostly) restores the ability to mount these
    filesystems using the old mount(2) system call (see below for the
    rest of the fix).

  * Remove not-NULL check for the data argument from the mount(2) entry
    point.  Per the mount(2) man page, it is up to the individual
    filesystem being mounted to verify data.  Or, in the case of procfs,
    etc. the filesystem is free to ignore the data parameter if it does
    not use it.  Enforcing data to be not-NULL in the mount(2) system call
    entry point prevented passing NULL to filesystems which ignored the
    data pointer value.  Apparently, passing NULL was common practice
    in such cases, as even our own mount_std(8) used to do it in the
    pre-nmount(2) world.

All userland programs in the tree were converted to nmount(2) long ago,
but I've found at least one external program which broke due to this
(presumably unintentional) mount(2) API change.  One could argue that
external programs should also be converted to nmount(2), but then there
isn't much point in keeping the mount(2) interface for backward
compatibility if it isn't backward compatible.
2006-05-15 19:42:10 +00:00
Tor Egge
87f0769a57 Call vn_start_write() before locking vnode. 2006-03-19 20:45:06 +00:00
Kris Kennaway
7d65872fff Correct the vnode locking in fdescfs.
PR:		kern/93905
Submitted by:	Kostik Belousov <kostikbel@gmail.com>
Reviewed by:	jeff
MFC After:	1 week
2006-02-28 00:05:44 +00:00
Robert Watson
5bb84bc84b Normalize a significant number of kernel malloc type names:
- Prefer '_' to ' ', as it results in more easily parsed results in
  memory monitoring tools such as vmstat.

- Remove punctuation that is incompatible with using memory type names
  as file names, such as '/' characters.

- Disambiguate some collisions by adding subsystem prefixes to some
  memory types.

- Generally prefer lower case to upper case.

- If the same type is defined in multiple architecture directories,
  attempt to use the same name in additional cases.

Not all instances were caught in this change, so more work is required to
finish this conversion.  Similar changes are required for UMA zone names.
2005-10-31 15:41:29 +00:00
David E. O'Brien
cec9a4bf57 Remove the need to forward declare statics by moving them around. 2005-08-10 07:08:14 +00:00
Jeff Roberson
d9b2d9f7a2 - Update vfs_root implementations to match the new prototype. None of
these filesystems will support shared locks until they are explicitly
   modified to do so.  Careful review must be done to ensure that this
   is safe for each individual filesystem.

Sponsored by:	Isilon Systems, Inc.
2005-03-24 07:36:16 +00:00
Jeff Roberson
8da0046596 - The VI_DOOMED flag now signals the end of a vnode's relationship with
the filesystem.  Check that rather than VI_XLOCK.
 - VOP_INACTIVE should no longer drop the vnode lock.
 - The vnode lock is required around calls to vrecycle() and vgone().

Sponsored by:	Isilon Systems, Inc.
2005-03-13 12:18:25 +00:00
Poul-Henning Kamp
9def42f333 Make fdesc_root static 2005-02-10 12:09:15 +00:00
Poul-Henning Kamp
83c6439714 Whitespace in vop_vector{} initializations. 2005-01-13 18:59:48 +00:00
Warner Losh
d167cf6f3a /* -> /*- for copyright notices, minor format tweaks as necessary 2005-01-06 18:10:42 +00:00
Poul-Henning Kamp
7ab8c8c03c Use vfs_mountedfrom(), rely on vfs_mount.c calling VFS_STATFS(). 2004-12-06 20:02:13 +00:00
Poul-Henning Kamp
743312367a VFS_STATFS(mp, ...) is mostly called with &mp->mnt_stat, but a few cases
doesn't.  Most of the implementations have grown weeds for this so they
copy some fields from mnt_stat if the passed argument isn't that.

Fix this the cleaner way:  Always call the implementation on mnt_stat
and copy that in toto to the VFS_STATFS argument if different.
2004-12-05 22:41:02 +00:00
Poul-Henning Kamp
aec0fb7b40 Back when VOP_* was introduced, we did not have new-style struct
initializations but we did have lofty goals and big ideals.

Adjust to more contemporary circumstances and gain type checking.

	Replace the entire vop_t frobbing thing with properly typed
	structures.  The only casualty is that we can not add a new
	VOP_ method with a loadable module.  History has not given
	us reason to belive this would ever be feasible in the the
	first place.

	Eliminate in toto VOCALL(), vop_t, VNODEOP_SET() etc.

	Give coda correct prototypes and function definitions for
	all vop_()s.

	Generate a bit more data from the vnode_if.src file:  a
	struct vop_vector and protype typedefs for all vop methods.

	Add a new vop_bypass() and make vop_default be a pointer
	to another struct vop_vector.

	Remove a lot of vfs_init since vop_vector is ready to use
	from the compiler.

	Cast various vop_mumble() to void * with uppercase name,
	for instance VOP_PANIC, VOP_NULL etc.

	Implement VCALL() by making vdesc_offset the offsetof() the
	relevant function pointer in vop_vector.  This is disgusting
	but since the code is generated by a script comparatively
	safe.  The alternative for nullfs etc. would be much worse.

	Fix up all vnode method vectors to remove casts so they
	become typesafe.  (The bulk of this is generated by scripts)
2004-12-01 23:16:38 +00:00
Poul-Henning Kamp
6fde64c778 Mechanically change prototypes for vnode operations to use the new typedefs. 2004-12-01 12:24:41 +00:00
Poul-Henning Kamp
124e4c3be8 Introduce an alias for FILEDESC_{UN}LOCK() with the suffix _FAST.
Use this in all the places where sleeping with the lock held is not
an issue.

The distinction will become significant once we finalize the exact
lock-type to use for this kind of case.
2004-11-13 11:53:02 +00:00
Poul-Henning Kamp
b0aed5267e Refuse attemps to mount root filesystem 2004-11-09 22:14:57 +00:00
Poul-Henning Kamp
5e8c582ac2 Put a version element in the VFS filesystem configuration structure
and refuse initializing filesystems with a wrong version.  This will
aid maintenance activites on the 5-stable branch.

s/vfs_mount/vfs_omount/

s/vfs_nmount/vfs_mount/

Name our filesystems mount function consistently.

Eliminate the namiedata argument to both vfs_mount and vfs_omount.
It was originally there to save stack space.  A few places abused
it to get hold of some credentials to pass around.  Effectively
it is unused.

Reorganize the root filesystem selection code.
2004-07-30 22:08:52 +00:00
Poul-Henning Kamp
a546742dd7 Make LINT compile 2004-07-13 09:46:46 +00:00
Alfred Perlstein
f257b7a54b Make VFS_ROOT() and vflush() take a thread argument.
This is to allow filesystems to decide based on the passed thread
which vnode to return.
Several filesystems used curthread, they now use the passed thread.
2004-07-12 08:14:09 +00:00
Warner Losh
f36cfd49ad 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 20:46:16 +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
Alexander Kabaev
c391349841 Fix vnode locking in fdesc_setattr. Lock vnode before invoking
VOP_SETATTR on it.

Approved by:	re@ (rwatson)
2003-11-19 04:14:42 +00:00
Poul-Henning Kamp
25d6da1b5e forgot to remove static declaration of fdesc_poll() 2003-09-27 12:34:41 +00:00
Poul-Henning Kamp
f1cf3def78 fdesc_poll() called seltrue() to do the default thing, this is pointlessly
wrong when we have a default in vop_nopoll() which does the right thing.
2003-09-27 12:24:42 +00:00
Poul-Henning Kamp
3b6d965263 Add a f_vnode field to struct file.
Several of the subtypes have an associated vnode which is used for
stuff like the f*() functions.

By giving the vnode a speparate field, a number of checks for the specific
subtype can be replaced simply with a check for f_vnode != NULL, and
we can later free f_data up to subtype specific use.

At this point in time, f_data still points to the vnode, so any code I
might have overlooked will still work.
2003-06-22 08:41:43 +00:00
Tim J. Robbins
8e78890396 Set f_mntfromname[] to "fdescfs" instead of "fdesc" for consistency
with other synthetic filesystems, which have f_mntfromname the same
as f_fstypename. Noticed by Sean Kelly on -current.
2003-06-17 09:00:15 +00:00
Poul-Henning Kamp
7652131bee Initialize struct vfsops C99-sparsely.
Submitted by:   hmp
Reviewed by:	phk
2003-06-12 20:48:38 +00:00
Alexander Kabaev
c162e9c2eb Rename vfs_stdsync function to vfs_stdnosync which matches more
closely what function is really doing. Update all existing consumers
to use the new name.

Introduce a new vfs_stdsync function, which iterates over mount
point's vnodes and call FSYNC on each one of them in turn.

Make nwfs and smbfs use this new function instead of rolling their
own identical sync implementations.

Reviewed by:	jeff
2003-03-11 22:15:10 +00:00
Nate Lawson
99648386d3 Finish cleanup of vprint() which was begun with changing v_tag to a string.
Remove extraneous uses of vop_null, instead defering to the default op.
Rename vnode type "vfs" to the more descriptive "syncer".
Fix formatting for various filesystems that use vop_print.
2003-03-03 19:15:40 +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
Dag-Erling Smørgrav
8994a245e0 Clean up whitespace, s/register //, refrain from strong urge to ANSIfy. 2003-03-02 15:56:49 +00:00
Dag-Erling Smørgrav
c952458814 uiomove-related caddr_t -> void * (just the low-hanging fruit) 2003-03-02 15:50:23 +00:00
Warner Losh
a163d034fa Back out M_* changes, per decision of the TRB.
Approved by: trb
2003-02-19 05:47:46 +00:00
Alfred Perlstein
44956c9863 Remove M_TRYWAIT/M_WAITOK/M_WAIT. Callers should use 0.
Merge M_NOWAIT/M_DONTWAIT into a single flag M_NOWAIT.
2003-01-21 08:56:16 +00:00
Matthew Dillon
48e3128b34 Bow to the whining masses and change a union back into void *. Retain
removal of unnecessary casts and throw in some minor cleanups to see if
anyone complains, just for the hell of it.
2003-01-13 00:33:17 +00:00
Matthew Dillon
cd72f2180b Change struct file f_data to un_data, a union of the correct struct
pointer types, and remove a huge number of casts from code using it.

Change struct xfile xf_data to xun_data (ABI is still compatible).

If we need to add a #define for f_data and xf_data we can, but I don't
think it will be necessary.  There are no operational changes in this
commit.
2003-01-12 01:37:13 +00:00
Poul-Henning Kamp
c6e3ae999b Since Jeffr made the std* functions the default in rev 1.63 of
kern/vfs_defaults.c it is wrong for the individual filesystems to use
the std* functions as that prevents override of the default.

Found by:       src/tools/tools/vop_table
2003-01-04 08:47:19 +00:00
Maxime Henrion
6d2eae5731 In VOP_LOOKUP, don't deny DELETE and RENAME operations
when ISLASTCN is not set.  The actual file which is being
looked up may live in a different filesystem.
2002-10-26 18:16:19 +00:00
Nate Lawson
86ed6d45ac Remove any VOP_PRINT that redundantly prints the tag.
Move lockmgr_printinfo() into vprint() for everyone's benefit.

Suggested by: bde
2002-09-18 20:42:04 +00:00
Nate Lawson
06be2aaa83 Remove all use of vnode->v_tag, replacing with appropriate substitutes.
v_tag is now const char * and should only be used for debugging.

Additionally:
1. All users of VT_NTS now check vfsconf->vf_type VFCF_NETWORK
2. The user of VT_PROCFS now checks for the new flag VV_PROCDEP, which
is propagated by pseudofs to all child vnodes if the fs sets PFS_PROCDEP.

Suggested by:   phk
Reviewed by:    bde, rwatson (earlier version)
2002-09-14 09:02:28 +00:00
Robert Watson
ea6027a8e1 Make similar changes to fo_stat() and fo_poll() as made earlier to
fo_read() and fo_write(): explicitly use the cred argument to fo_poll()
as "active_cred" using the passed file descriptor's f_cred reference
to provide access to the file credential.  Add an active_cred
argument to fo_stat() so that implementers have access to the active
credential as well as the file credential.  Generally modify callers
of fo_stat() to pass in td->td_ucred rather than fp->f_cred, which
was redundantly provided via the fp argument.  This set of modifications
also permits threads to perform these operations on behalf of another
thread without modifying their credential.

Trickle this change down into fo_stat/poll() implementations:

- badfo_poll(), badfo_stat(): modify/add arguments.
- kqueue_poll(), kqueue_stat(): modify arguments.
- pipe_poll(), pipe_stat(): modify/add arguments, pass active_cred to
  MAC checks rather than td->td_ucred.
- soo_poll(), soo_stat(): modify/add arguments, pass fp->f_cred rather
  than cred to pru_sopoll() to maintain current semantics.
- sopoll(): moidfy arguments.
- vn_poll(), vn_statfile(): modify/add arguments, pass new arguments
  to vn_stat().  Pass active_cred to MAC and fp->f_cred to VOP_POLL()
  to maintian current semantics.
- vn_close(): rename cred to file_cred to reflect reality while I'm here.
- vn_stat(): Add active_cred and file_cred arguments to vn_stat()
  and consumers so that this distinction is maintained at the VFS
  as well as 'struct file' layer.  Pass active_cred instead of
  td->td_ucred to MAC and to VOP_GETATTR() to maintain current semantics.

- fifofs: modify the creation of a "filetemp" so that the file
  credential is properly initialized and can be used in the socket
  code if desired.  Pass ap->a_td->td_ucred as the active
  credential to soo_poll().  If we teach the vnop interface about
  the distinction between file and active credentials, we would use
  the active credential here.

Note that current inconsistent passing of active_cred vs. file_cred to
VOP's is maintained.  It's not clear why GETATTR would be authorized
using active_cred while POLL would be authorized using file_cred at
the file system level.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, NAI Labs
2002-08-16 12:52:03 +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
Jeff Roberson
ad70122060 - Change all LK_SHARE locks to LK_EXCLUSIVE. Shared locks aren't quite safe
yet
 - Use vop_std{lock,unlock,islocked}.
2002-07-09 19:43:39 +00:00
Maxime Henrion
4d8b916946 Convert fdescfs to nmount.
Reviewed by:	phk
2002-05-02 20:24:50 +00:00
Alfred Perlstein
11caded34f Remove __P. 2002-03-19 22:20:14 +00:00
Alfred Perlstein
a4db49537b Replace ffind_* with fget calls.
Make fget MPsafe.

Make fgetvp and fgetsock use the fget subsystem to reduce code bloat.

Push giant down in fpathconf().
2002-01-14 00:13:45 +00:00
Alfred Perlstein
9e209b124a Include sys/_lock.h and sys/_mutex.h to reduce namespace pollution.
Requested by: jhb
2002-01-13 21:37:49 +00:00
Alfred Perlstein
426da3bcfb SMP Lock struct file, filedesc and the global file list.
Seigo Tanimura (tanimura) posted the initial delta.

I've polished it quite a bit reducing the need for locking and
adapting it for KSE.

Locks:

1 mutex in each filedesc
   protects all the fields.
   protects "struct file" initialization, while a struct file
     is being changed from &badfileops -> &pipeops or something
     the filedesc should be locked.

1 mutex in each struct file
   protects the refcount fields.
   doesn't protect anything else.
   the flags used for garbage collection have been moved to
     f_gcflag which was the FILLER short, this doesn't need
     locking because the garbage collection is a single threaded
     container.
  could likely be made to use a pool mutex.

1 sx lock for the global filelist.

struct file *	fhold(struct file *fp);
        /* increments reference count on a file */

struct file *	fhold_locked(struct file *fp);
        /* like fhold but expects file to locked */

struct file *	ffind_hold(struct thread *, int fd);
        /* finds the struct file in thread, adds one reference and
                returns it unlocked */

struct file *	ffind_lock(struct thread *, int fd);
        /* ffind_hold, but returns file locked */

I still have to smp-safe the fget cruft, I'll get to that asap.
2002-01-13 11:58:06 +00:00