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
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
function which is called from pfs_destroy() before the node is reclaimed.
Modify pfs_create_{dir,file,link}() to accept a pointer to a destructor
function in addition to the usual attr / fill / vis pointers.
This breaks both the programming and binary interfaces between pseudofs
and its consumers. It is believed that there are no pseudofs consumers
outside the source tree, so that the impact of this change is minimal.
Submitted by: Aniruddha Bohra <bohra@cs.rutgers.edu>
This way we may support multiple structures in v_data vnode field within
one file system without using black magic.
Vnode-to-file-handle should be VOP in the first place, but was made VFS
operation to keep interface as compatible as possible with SUN's VFS.
BTW. Now Solaris also implements vnode-to-file-handle as VOP operation.
VFS_VPTOFH() was left for API backward compatibility, but is marked for
removal before 8.0-RELEASE.
Approved by: mckusick
Discussed with: many (on IRC)
Tested with: ufs, msdosfs, cd9660, nullfs and zfs
the value of p_textvp. This way, we always unlock the locked vnode.
While there, vhold() the vnode around the vn_lock().
Reported and tested by: Guy Helmer (ghelmer palisadesys com)
Approved by: des (procfs maintainer)
MFC after: 1 week
#ifdef MSDOSFS_LARGE to run-time checks to see if "-o large" was specified.
Test case provided by Oliver Fromme:
truncate -s 200G test.img
mdconfig -a -t vnode -f test.img -u 9
newfs_msdos -s 419430400 -n 1 /dev/md9 zip250
mount -t msdosfs /dev/md9 /mnt # should fail
mount -t msdosfs -o large /dev/md9 /mnt # should succeed
PR: 105964
Requested by: Oliver Fromme <olli lurza secnetix de>
Tested by: trhodes
MFC after: 2 weeks
--------------------------
[Deadlock] is caused by a lock order reversal in vfs_lookup(), where
[some] process is trying to lock a directory vnode, that is the parent
directory of covered vnode) while holding an exclusive vnode lock on
covering vnode.
A simplified scenario:
root fs var fs
/ A / (/var) D
/var B /log (/var/log) E
vfs lock C vfs lock F
Within each file system, the lock order is clear: C->A->B and F->D->E
When traversing across mounts, the system can choose between two lock orders,
but everything must then follow that lock order:
L1: C->A->B
|
+->F->D->E
L2: F->D->E
|
+->C->A->B
The lookup() process for namei("/var") mixes those two lock orders:
VOP_LOOKUP() obtains B while A is held
vfs_busy() obtains a shared lock on F while A and B are held (follows L1,
violates L2)
vput() releases lock on B
VOP_UNLOCK() releases lock on A
VFS_ROOT() obtains lock on D while shared lock on F is held
vfs_unbusy() releases shared lock on F
vn_lock() obtains lock on A while D is held (violates L1, follows L2)
dounmount() follows L1 (B is locked while F is drained).
Without unmount activity, vfs_busy() will always succeed without blocking
and the deadlock isn't triggered (the system behaves as if L2 is followed).
With unmount, you can get 4 processes in a deadlock:
p1: holds D, want A (in lookup())
p2: holds shared lock on F, want D (in VFS_ROOT())
p3: holds B, want drain lock on F (in dounmount())
p4: holds A, want B (in VOP_LOOKUP())
You can have more than one instance of p2.
The reversal was introduced in revision 1.81 of src/sys/kern/vfs_lookup.c and
MFCed to revision 1.80.2.1, probably to avoid a cascade of vnode locks when nfs
servers are dead (VFS_ROOT() just hangs) spreading to the root fs root vnode.
- Tor Egge
To fix the LOR, ups@ noted that when crossing the mount point, ni_dvp
is actually not used by the callers of namei. Thus, placeholder deadfs
vnode vp_crossmp is introduced that is filled into ni_dvp.
Idea by: ups
Reviewed by: tegge, ups, jeff, rwatson (mac interaction)
Tested by: Peter Holm
MFC after: 2 weeks
from just before extending a file. This has the desired effect
of keeping the write speed constant. And yes, that helps a lot
copying large files always at full speed now, and I have seen
improvements using benchmarks/bonnie.
Stolen from: NetBSD
Reviewed by: bde
The code is modelled after cd9660, including support for simple read-ahead
courtesy of clustered read.
Fix udf_strategy to DTRT.
This change fixes sendfile(2) not to send out garbage.
Reviewed by: scottl
MFC after: 1 month
do not call markvoldirty() until the mount has been flagged as read-write.
Due to the nature of the msdosfs code, this bug only seemed to appear for
FAT-16 and FAT-32.
This fixes the testcase:
#!/bin/sh
dd if=/dev/zero bs=1m count=1 oseek=119 of=image.msdos
mdconfig -a -t vnode -f image.msdos
newfs_msdos -F 16 /dev/md0 fd120m
mount_msdosfs -o ro /dev/md0 /mnt
mount | grep md0
mount -u -o rw /dev/md0; echo $?
mount | grep md0
umount /mnt
mdconfig -d -u 0
PR: 105412
Tested by: Eugene Grosbein <eugen grosbein pp ru>
functions now more closely resemble similar functions in nullfs.
This also eliminates some errors.
Submitted by: daichi, Masanori OZAWA <ozawa ongs co jp>
This macro was written expecting a 32-bit unsigned long, and
doesn't work properly on 64-bit systems. This bug caused vn_stat()
to return incorrect values for files larger than 2gb on msdosfs filesystems
on 64-bit systems.
PR: 106703
Submitted by: Axel Gonzalez <loox e-shell net>
MFC after: 3 days
This bug caused vn_stat() to fail on files larger than 2gb on msdosfs
filesystems on AMD64.
PR: 106703
Tested by: Axel Gonzalez <loox e-shell net>
MFC after: 3 days
an "export" flag indicating that we are trying to NFS export the
filesystem, and the MSDOSFS_LARGEFS flag is set on the filesystem,
then deny the mount update and export request. Otherwise,
let the full mount update proceed normally.
MSDOSFS_LARGES and NFS don't mix because of the way inodes are calculated
for MSDOSFS_LARGEFS.
MFC after: 3 days
field to "unsigned long" so that it actually works.
Thanks to Robert Sciuk for sending me a DVD that
demonstrated ISO9660-formatted media with a file >2G.
I've now fixed this both in libarchive and in the cd9660
filesystem.
MFC after: 14 days
Make part of John Birrell's KSE patch permanent..
Specifically, remove:
Any reference of the ksegrp structure. This feature was
never fully utilised and made things overly complicated.
All code in the scheduler that tried to make threaded programs
fair to unthreaded programs. Libpthread processes will already
do this to some extent and libthr processes already disable it.
Also:
Since this makes such a big change to the scheduler(s), take the opportunity
to rename some structures and elements that had to be moved anyhow.
This makes the code a lot more readable.
The ULE scheduler compiles again but I have no idea if it works.
The 4bsd scheduler still reqires a little cleaning and some functions that now do
ALMOST nothing will go away, but I thought I'd do that as a separate commit.
Tested by David Xu, and Dan Eischen using libthr and libpthread.
set birthtime to FAT CTime (creation time) and in the other cases
set birthtime to -1.
o Set ctime to mtime instead of FAT CTime which has completely
different meaning.
PR: kern/106018
Submitted by: Oliver Fromme
MFC after: 1 month
and Daichi GOTO <daichi@FreeBSD.org> for submitting this
major rewrite of unionfs. This rewrite was done to
try to solve many of the longstanding crashing and locking
issues in the existing unionfs implementation. This
implementation also adds a 'MASQUERADE mode', which allows
the user to set different user, group, and file permission
modes in the upper layer.
Submitted by: daichi, Masanori OZAWA
Reviewed by: rodrigc (modified for minor style issues)
LCASE_BASE or LCASE_EXT or both are set. But dos2unixfn uses
dos2unixchr separately for the basename and the extension. So if
either LCASE_BASE or LCASE_EXT is set, dos2unixfn will convert both
the basename and extension to lowercase because it is blindly
passing in the state of both flags to dos2unixchr. The bit masks I
used ensure that only the state of LCASE_BASE gets passed to
dos2unixchr when the basename is converted, and only the state of
LCASE_EXT is passed in when the extension is converted.
PR: kern/86655
Submitted by: Micah Lieske
MFC after: 3 weeks
events. &p->p_stype is explicitely woken up on process exit for us.
Now, truss /nonexistent exits with error instead of waiting until killed
by signal.
Reported by: Nikos Vassiliadis nvass at teledomenet gr
Reviewed by: jhb
MFC after: 1 week
specific privilege names to a broad range of privileges. These may
require some future tweaking.
Sponsored by: nCircle Network Security, Inc.
Obtained from: TrustedBSD Project
Discussed on: arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
Alex Lyashkov <umka at sevcity dot net>,
Skip Ford <skip dot ford at verizon dot net>,
Antoine Brodin <antoine dot brodin at laposte dot net>
