- Set UN_ULOCK in union_lock() when UN_KLOCK is set. Caller expects
that vnode is locked correctly, and may call another function which
expects locked vnode and may unlock the vnode.
- Do not assume the behavior of inside functions in FreeBSD's
vfs_suber.c is same as 4.4BSD-Lite2. Vnode may be locked in
vget() even though flag is zero. (Locked vnode is, of course,
unlocked before returning from vget.)
original BSD code. The association between the vnode and the vm_object
no longer includes reference counts. The major difference is that
vm_object's are no longer freed gratuitiously from the vnode, and so
once an object is created for the vnode, it will last as long as the
vnode does.
When a vnode object reference count is incremented, then the underlying
vnode reference count is incremented also. The two "objects" are now
more intimately related, and so the interactions are now much less
complex.
When vnodes are now normally placed onto the free queue with an object still
attached. The rundown of the object happens at vnode rundown time, and
happens with exactly the same filesystem semantics of the original VFS
code. There is absolutely no need for vnode_pager_uncache and other
travesties like that anymore.
A side-effect of these changes is that SMP locking should be much simpler,
the I/O copyin/copyout optimizations work, NFS should be more ponderable,
and further work on layered filesystems should be less frustrating, because
of the totally coherent management of the vnode objects and vnodes.
Please be careful with your system while running this code, but I would
greatly appreciate feedback as soon a reasonably possible.
of vnodes and objects. There are some metadata performance improvements
that come along with this. There are also a few prototypes added when
the need is noticed. Changes include:
1) Cleaning up vref, vget.
2) Removal of the object cache.
3) Nuke vnode_pager_uncache and friends, because they aren't needed anymore.
4) Correct some missing LK_RETRY's in vn_lock.
5) Correct the page range in the code for msync.
Be gentle, and please give me feedback asap.
half the way down. Otherwise, further attempts to mount the device
will be rejected with BUSY.
IMHO, this flag can completely go away for cd9660. There's no reason
you need to prevent CDs from being mounted multiple times, and in case
of multisession CDs it can even make sense to mount two different
sessions by the same time (to different mount points, otherwise it
would be pointless ;).
flag is set in the p_pfsflags field. This, essentially, prevents an SUID
proram from hanging after being traced. (E.g., "truss /usr/bin/rlogin" would
fail, but leave rlogin in a stopevent state.) Yet another case where procctl
is (hopefully ;)) no longer needed in the general case.
Reviewed by: bde (thanks bruce :))
if one of the new poll types is requested; hopefully this will not break
any existing code. (This is done so that programs have a dependable
way of determining whether a filesystem supports the extended poll types
or not.)
The new poll types added are:
POLLWRITE - file contents may have been modified
POLLNLINK - file was linked, unlinked, or renamed
POLLATTRIB - file's attributes may have been changed
POLLEXTEND - file was extended
Note that the internal operation of poll() means that it is impossible
for two processes to reliably poll for the same event (this could
be fixed but may not be worth it), so it is not possible to rewrite
`tail -f' to use poll at this time.
1. SS_CANTRCVMORE was initially set on the wrong socket, so reads
when there has never been a writer on the socket did not return 0.
Note that such reads are only possible if the fifo was opened in
(O_RDONLY | O_NONBLOCK) mode.
2. SS_CANTSENDMORE was initially set on the wrong socket, but this
was harmless because the wrong socket is never sent from and there
is no need to set the flag initially on the right socket (since open
in (O_WRONLY | O_NONBLOCK) mode fails if there is no reader...).
3. SS_CANTRCVMORE was cleared when read() returns. This broke the
case where read() returns 0 - subsequent reads are supposed to
return 0 until a writer appears. There is no need to clear the
flag when read() returns, since it is cleared correctly when a
writer appears.
general to be of much use. Using it here weakened the _PC_MAX_CANON,
_PC_MAX_INPUT and _PC_VDISABLE cases.
fifo_pathconf() is not quite correct either. _PC_CHOWN_RESTRICTED
and _PC_LINK_MAX should be handled by the host file system. For
directories, the host file system should let us handle _PC_PIPE_BUF.
change from
ioctl(fd, PIOC<foo>, &i);
to
ioctl(fd, PIOC<foo>, i);
This is going from the _IOW to _IO ioctl macro. The kernel, procctl, and
truss must be in synch for it all to work (not doing so will get errors about
inappropriate ioctl's, fortunately). Hopefully I didn't forget anything :).
nodes; this also apparantly caused a panic in some circumstances.
Also, since procfs_exit() is getting rid of the nodes when a process
exits, don't bother checking for the process' existance in procfs_inactive().
what is teh root cause -- but, sometimes, a procfs vnode in pfshead is
apparantly corrupt (or a UFS vnode instead). Without this patch, I can
get it to panic by doing (in csh)
while (1)
ps auxwww
end
and it will panic when the PID's wrap. With it, it does not panic.
Yes -- I know that this is NOT the right way to fix it. But I haven't
been able to get it to panic yet (which confuses me). I am going to
be looking into the vgone() code now, as that may be a part of it.
me; unfortunately, also makes it hard ot check for errors); second, I had
managed to forget a change to PIOCSFL (it should be _IOW, not _IOR) I had
in my local copy, and Bruce called me on it.
Submitted by: bde
Note that an unload facility should be used to call rm_at_exit() (if
procfs is being loaded as an LKM and is subsequently removed), but it
was non-obvious how to do this in the VFS framework.
Reviewed by: Julian Elischer
procfs/mem file. While this doesn't prevent an unkillable process, it
means that a broken truss prorgam won't do it accidently now (well,
there's a small window of opportunity). Note that this requires the
change to truss I am about to commit.
Ever since I first say the way the mount flags were used I've hated the
fact that modes, and events, internal and exported, and short-term
and long term flags are all thrown together. Finally it's annoyed me enough..
This patch to the entire FreeBSD tree adds a second mount flag word
to the mount struct. it is not exported to userspace. I have moved
some of the non exported flags over to this word. this means that we now
have 8 free bits in the mount flags. There are another two that might
well move over, but which I'm not sure about.
The only user visible change would have been in pstat -v, except
that davidg has disabled it anyhow.
I'd still like to move the state flags and the 'command' flags
apart from each other.. e.g. MNT_FORCE really doesn't have the
same semantics as MNT_RDONLY, but that's left for another day.
it in struct proc instead.
This fixes a boatload of compiler warning, and removes a lot of cruft
from the sources.
I have not removed the /*ARGSUSED*/, they will require some looking at.
libkvm, ps and other userland struct proc frobbing programs will need
recompiled.
in a file. There was a (harmless, I think) off-by-1 error. This
was fixed in ufs long ago (rev.1.21 of ufs_readwrite.c) but not
in cd9660.
cd9660_read() has stagnated in many other ways. It is closer to
the Net/2 ufs_read() (which is was cloned from) than ufs_read()
itself is.
Rename vn_default_error to vop_defaultop all over the place.
Move vn_bwrite from vfs_bio.c to vfs_default.c and call it vop_stdbwrite.
Use vop_null instead of nullop.
Move vop_nopoll from vfs_subr.c to vfs_default.c
Move vop_sharedlock from vfs_subr.c to vfs_default.c
Move vop_nolock from vfs_subr.c to vfs_default.c
Move vop_nounlock from vfs_subr.c to vfs_default.c
Move vop_noislocked from vfs_subr.c to vfs_default.c
Use vop_ebadf instead of *_ebadf.
Add vop_defaultop for getpages on master vnode in MFS.
1. Add defaults for more VOPs
VOP_LOCK vop_nolock
VOP_ISLOCKED vop_noislocked
VOP_UNLOCK vop_nounlock
and remove direct reference in filesystems.
2. Rename the nfsv2 vnop tables to improve sorting order.
1. Remove VOP_UPDATE, it is (also) an UFS/{FFS,LFS,EXT2FS,MFS}
intereface function, and now lives in the ufsmount structure.
2. Remove VOP_SEEK, it was unused.
3. Add mode default vops:
VOP_ADVLOCK vop_einval
VOP_CLOSE vop_null
VOP_FSYNC vop_null
VOP_IOCTL vop_enotty
VOP_MMAP vop_einval
VOP_OPEN vop_null
VOP_PATHCONF vop_einval
VOP_READLINK vop_einval
VOP_REALLOCBLKS vop_eopnotsupp
And remove identical functionality from filesystems
4. Add vop_stdpathconf, which returns the canonical stuff. Use
it in the filesystems. (XXX: It's probably wrong that specfs
and fifofs sets this vop, shouldn't it come from the "host"
filesystem, for instance ufs or cd9660 ?)
5. Try to make system wide VOP functions have vop_* names.
6. Initialize the um_* vectors in LFS.
(Recompile your LKMS!!!)
1. Add new file "sys/kern/vfs_default.c" where default actions for
VOPs go. Implement proper defaults for ABORTOP, BWRITE, LEASE,
POLL, REVOKE and STRATEGY. Various stuff spread over the entire
tree belongs here.
2. Change VOP_BLKATOFF to a normal function in cd9660.
3. Kill VOP_BLKATOFF, VOP_TRUNCATE, VOP_VFREE, VOP_VALLOC. These
are private interface functions between UFS and the underlying
storage manager layer (FFS/LFS/MFS/EXT2FS). The functions now
live in struct ufsmount instead.
4. Remove a kludge of VOP_ functions in all filesystems, that did
nothing but obscure the simplicity and break the expandability.
If a filesystem doesn't implement VOP_FOO, it shouldn't have an
entry for it in its vnops table. The system will try to DTRT
if it is not implemented. There are still some cruft left, but
the bulk of it is done.
5. Fix another VCALL in vfs_cache.c (thanks Bruce!)
1. Use the default function to access all the specfs operations.
2. Use the default function to access all the fifofs operations.
3. Use the default function to access all the ufs operations.
4. Fix VCALL usage in vfs_cache.c
5. Use VOCALL to access specfs functions in devfs_vnops.c
6. Staticize most of the spec and fifofs vnops functions.
7. Make UFS panic if it lacks bits of the underlying storage handling.
1. Remove comment stating the blatantly obvious.
2. Align in two columns.
3. Sort all but the default element alphabetically.
4. Remove XXX comments pointing out entries not needed.
Distribute all but the most fundamental malloc types. This time I also
remembered the trick to making things static: Put "static" in front of
them.
A couple of finer points by: bde
1. Clustered I/O is switched by the MNT_NOCLUSTERR and MNT_NOCLUSTERW
bits of the mnt_flag. The sysctl variables, vfs.foo.doclusterread
and vfs.foo.doclusterwrite are deleted. Only mount option can
control clustered I/O from userland.
2. When foofs_mount mounts block device, foofs_mount checks D_CLUSTERR
and D_CLUSTERW bits of the d_flags member in the block device switch
table. If D_NOCLUSTERR / D_NOCLUSTERW are set, MNT_NOCLUSTERR /
MNT_NOCLUSTERW bits will be set. In this case, MNT_NOCLUSTERR and
MNT_NOCLUSTERW cannot be cleared from userland.
3. Vnode driver disables both clustered read and write.
4. Union filesystem disables clutered write.
Reviewed by: bde
plus the previous changes to use the zone allocator decrease the useage
of malloc by half. The Zone allocator will be upgradeable to be able
to use per CPU-pools, and has more intelligent usage of SPLs. Additionally,
it has reasonable stats gathering capabilities, while making most calls
inline.
This unifies several times in theory indentical 50 lines of code.
The filesystems have a new method: vop_cachedlookup, which is the
meat of the lookup, and use vfs_cache_lookup() for their vop_lookup
method. vfs_cache_lookup() will check the namecache and pass on
to the vop_cachedlookup method in case of a miss.
It's still the task of the individual filesystems to populate the
namecache with cache_enter().
Filesystems that do not use the namecache will just provide the
vop_lookup method as usual.
free list problem. Also, the vnode age flag is no longer used by the
vnode pager. (It is actually incorrect to use then.) Constructive
feedback welcome -- just be kind.
socket addresses in mbufs. (Socket buffers are the one exception.) A number
of kernel APIs needed to get fixed in order to make this happen. Also,
fix three protocol families which kept PCBs in mbufs to not malloc them
instead. Delete some old compatibility cruft while we're at it, and add
some new routines in the in_cksum family.
uerror == 0 && lerror == EACCES, lowervp == NULLVP and union_allocvp
doesn't find existing union node and new union node is created.
Sicne it is dificult to cover all the case, union_lookup always
returns when union_lookup1() returns EACCES.
Submitted by: Naofumi Honda <honda@Kururu.math.sci.hokudai.ac.jp>
Obtained from: NetBSD/pc98
reading/writing of mem and regs). Also have to check for the requesting
process being group KMEM -- this is a bit of a hack, but ps et al need it.
Reviewed by: davidg
. It makes cd9660 root f/s working again.
. It makes CD9660 a new-style option.
. It adds support to mount an ISO9660 multi-session CD-ROM as the root
filesystem (the last session actually, but that's what is expected
behaviour).
Sigh. The CDIOREADTOCENTRYS did a copyout() of its own, and thus has
been unusable for me for this work. Too bad it didn't simply stuff
the max 100 entries into the struct ioc_read_toc_entry, but relied on
a user supplied data buffer instead. :-( I now had to reinvent the
wheel, and created a CDIOREADTOCENTRY ioctl command that can be used
in a kernel context.
While doing this, i noticed the following bogosities in existing CD-ROM
drivers:
wcd: This driver is likely to be totally bogus when someone tries
two succeeding CDIOREADTOCENTRYS (or now CDIOREADTOCENTRY)
commands with requesting MSF format, since it apparently
operates on an internal table.
scd: This driver apparently returns just a single TOC entry only for
the CDIOREADTOCENTRYS command.
I have only been able to test the CDIOREADTOCENTRY command with the
cd(4) driver. I hereby request the respective maintainers of the
other CD-ROM drivers to verify my code for their driver. When it
comes to merging this CD-ROM multisession stuff into RELENG_2_2 i will
only consider drivers where i've got a confirmation that it actually
works.
in savedvp variable and it is used for the argument of
MOUNTTOUNIONMOUNT(). I didn't realize ap->a_vp is modified before
MOUNTTOUNIONMOUNT(), so the change by revision 1.22 is incorrect.
but searching the directory on something else than the default
location.
NB: this comprises an interface change to the mount_cd9660(8)
utility (commit will follow). You need to rebuild both.
I've got similar patches for RELENG_2_2, should i commit them too?
UN_KLOCK flag.
When UN_KLOCK is set, VOP_UNLOCK should keep uppervp locked and clear
UN_ULOCK flag. To do this, when UN_KLOCK is set, (1) union_unlock
clears UN_ULOCK and does not clear UN_KLOCK, (2) union_lock() does not
access uppervp and does not clear UN_KLOCK, and (3) callers of
vput/VOP_UNLOCK should clear UN_KLOCK. For example, vput becomes:
SETKLOCK(union_node);
vput(vnode);
CLEARKLOCK(union_node);
where SETKLOCK macro sets UN_KLOCK and CLEARKLOCK macro clears
UN_KLOCK.
Our vput calls vm_object_deallocate() --> vm_object_terminate(). The
vm_object_terminate() calls vn_lock(), since UN_LOCKED has been
already cleared in union_unlock(). Then, union_lock locks upper vnode
when UN_ULOCK is not set. The upper vnode is not unlocked when
UN_KLOCK is set in union_unlock(), thus, union_lock tries to lock
locked vnode and we get panic.
UN_ULOCK flag. This shows a locking violation but I couldn't find the
reason UN_ULOCK is not set or upper vnode is not unlocked. I added
the code that detect this case and adjust un_flags. DIAGNOSTIC kernel
doesn't adjust un_flags, but just panic here to help debug by kernel
hackers.
# mount -t union (or null) dir1 dir2
# mount -t union (or null) dir2 dir1
The function namei in union_mount calls union_root. The upper vnode
has been already locked and vn_lock in union_root causes above panic.
Add printf's included in `#ifdef DIAGNOSTIC' for EDEADLK cases.
is NULLVP, union node will have neither uppervp nor lowervp. This
causes page fault trap.
The union_removed_upper just remove union node from cache and it
doesn't set uppervp to NULLVP. Since union node is removed from
cache, it will not be referenced.
The code that remove union node from cache was copied from
union_inactive.
VOP_LINK(). The reason of strange behavior was wrong order of the
argument, that is, the operation
# ln foo bar
in a union fs tried to do
# ln bar foo
in ufs layer.
Now we can make a link in a union fs.
fix!
The ufs_link() assumes that vnode is not unlocked and tries to lock it
in certain case. Because union_link calls VOP_LINK after locking vnode,
vn_lock in ufs_link causes above panic.
Currently, I don't know the real fix for a locking violation in
union_link, but I think it is important to avoid panic.
A vnode is unlocked before calling VOP_LINK and is locked after it if
the vnode is not union fs. Even though panic went away, the process
that access the union fs in which link was made will hang-up.
Hang-up can be easily reproduced by following operation:
mount -t union a b
cd b
ln foo bar
ls
same directory pair.
If we do:
mount -t union a b
mount -t union a b
then, (1) namei tries to lock fs which has been already locked by
first union mount and (2) union_root() tries to lock locked fs. To
avoid first deadlock condition, unlock vnode if lowerrootvp is union
node, and to avoid second case, union_mount returns EDEADLK when multi
union mount is detected.
dolock is not set (that is, targetvp == overlaying vnode object).
Current code use FIXUP macro to do this, and never unlocks overlaying
vnode object in union_fsync. So, the vnode object will be locked
twice and never unlocked.
PR: 3271
Submitted by: kato
relookup() in union_relookup() is succeeded. However, if relookup()
returns non-zero value, that is relookup fails, VOP_MKDIR is never
called (c.f. union_mkshadow). Thus, pathname buffer is never FREEed.
Reviewed by: phk
Submitted by: kato
PR: 3262
by Alan Cox <alc@cs.rice.edu>, and his description of the problem.
The bug was primarily in procfs_mem, but the mistake likely happened
due to the lack of vm system support for the operation. I added
better support for selective marking of page dirty flags so that
vm_map_pageable(wiring) will not cause this problem again.
The code in procfs_mem is now less bogus (but maybe still a little
so.)
of setting it (compiled into vfs_conf.c), but we have a dynamic system
in place. This could probably be better done via a runtime configure
flag in the VFS_SET() VFS declaration, perhaps VFCF_LOCAL, and have the
VFS code propagate this down into MNT_LOCAL at mount time. The other FS's
would need to be updated, havinf UFS and MSDOSFS filesystems without
MNT_LOCAL breaks a few things.. the man page rebuild scans for local
filesystems and currently fails, I suspect that other tools like find
and tar with their "local filesystem only" modes might be affected.
in procfs_allocvp(). This fixes at least stat() of /proc/*/mem.
stat() of /proc/*/file already worked. I think procfs_allocvp() isn't
actually called for type Pfile.
partly because the #define's for them were moved to a different
file. At least the null VOP_LOCK() no longer works, since vclean()
expects VOP_LOCK( ..., LK_DRAIN | LK_INTERLOCK, ...) to clear the
interlock. This probably only matters when simple_lock() is not
null, i.e., when there are multiple CPUs or SIMPLELOCK_DEBUG is
defined.
- *fs_init routines now take a "struct vfsconf * vfsp" pointer
as an argument.
- Use the correct type for cookies.
- Update function prototypes.
Submitted by: bde
changes, so don't expect to be able to run the kernel as-is (very well)
without the appropriate Lite/2 userland changes.
The system boots and can mount UFS filesystems.
Untested: ext2fs, msdosfs, NFS
Known problems: Incorrect Berkeley ID strings in some files.
Mount_std mounts will not work until the getfsent
library routine is changed.
Reviewed by: various people
Submitted by: Jeffery Hsu <hsu@freebsd.org>
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
Firstly, now our read-ahead clustering is on a file descriptor basis and not
on a per-vnode basis. This will allow multiple processes reading the
same file to take advantage of read-ahead clustering. Secondly, there
previously was a problem with large reads still using the ramp-up
algorithm. Of course, that was bogus, and now we read the entire
"chunk" off of the disk in one operation. The read-ahead clustering
algorithm should use less CPU than the previous also (I hope :-)).
NOTE: THAT LKMS MUST BE REBUILT!!!
successful write. Only do it for the IO_SYNC case (like ufs). On
one of my systems, this speeds up `iozone 24 512' from 32K/sec
(1/128 as fast as ufs) to 2.8MB/sec (7/10 as fast as ufs).
Obtained from: partly from NetBSD
Broke locking on named pipes in the same way as locking on non-vnodes
(wrong errno). This will be fixed later.
The fix involves negative logic. Named pipes are now distinguished from
other types of files with vnodes, and there is additional code to handle
vnodes and named pipes in the same way only where that makes sense (not
for lseek, locking or TIOCSCTTY).
fcntl() and EOPNOTSUPP for flock(). POSIX specifies the weaker EINVAL
errno and the man page agrees.
Not fixed:
deadfs: always returns wrong EBADF
devfs, msdosfs: always return sometimes-wrong EINVAL
cd9660, fdesc, kernfs, portal: always return sometimes-wrong EOPNOTSUPP
procfs: always returns wrong EIO
mfs: panic?!
nfs: fudged
NetBSD uses a generic file system genfs to do return the sometimes-wrong
EOPNOTSUPP more consistently :-)(.
Found by: NIST-PCTS
