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.
Add local rootvp variables as needed.
Remove checks for miniroot's in the swappartition. We never did that
and most of the filesystems could never be used for that, but it had
still been copy&pasted all over the place.
somewhat clearer, but more importantly allows for a consistent naming
scheme for suser_cred flags.
The old name is still defined, but will be removed in a few days (unless I
hear any complaints...)
Discussed with: rwatson, scottl
Requested by: jhb
the caller passes in a td that is curthread, and consistently pass 'td'
into vget(). Remove some bogus logic that passed in td or curthread
conditional on td being non-NULL, which seems redundant in the face of
the earlier assignment of td to curthread if td is NULL.
In devfs_symlink(), cache the passed thread in 'td' so we don't have
to keep retrieving it from the 'ap' structure, and assert that td is
curthread (since we dereference it to get thread-local td_ucred). Use
'td' in preference to curthread for later lockmgr calls, since they are
equal.
for unknown events.
A number of modules return EINVAL in this instance, and I have left
those alone for now and instead taught MOD_QUIESCE to accept this
as "didn't do anything".
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.
one go before returning. This avoids calling uiomove() while holding
allproc_lock.
Don't adjust uio->uio_offset manually, uiomove() does that for us.
Don't drop allproc_lock before calling panic().
Suggested by: alfred
our cached 'next vnode' being removed from this mountpoint. If we
find that it was recycled, we restart our traversal from the start
of the list.
Code to do that is in all local disk filesystems (and a few other
places) and looks roughly like this:
MNT_ILOCK(mp);
loop:
for (vp = TAILQ_FIRST(&mp...);
(vp = nvp) != NULL;
nvp = TAILQ_NEXT(vp,...)) {
if (vp->v_mount != mp)
goto loop;
MNT_IUNLOCK(mp);
...
MNT_ILOCK(mp);
}
MNT_IUNLOCK(mp);
The code which takes vnodes off a mountpoint looks like this:
MNT_ILOCK(vp->v_mount);
...
TAILQ_REMOVE(&vp->v_mount->mnt_nvnodelist, vp, v_nmntvnodes);
...
MNT_IUNLOCK(vp->v_mount);
...
vp->v_mount = something;
(Take a moment and try to spot the locking error before you read on.)
On a SMP system, one CPU could have removed nvp from our mountlist
but not yet gotten to assign a new value to vp->v_mount while another
CPU simultaneously get to the top of the traversal loop where it
finds that (vp->v_mount != mp) is not true despite the fact that
the vnode has indeed been removed from our mountpoint.
Fix:
Introduce the macro MNT_VNODE_FOREACH() to traverse the list of
vnodes on a mountpoint while taking into account that vnodes may
be removed from the list as we go. This saves approx 65 lines of
duplicated code.
Split the insmntque() which potentially moves a vnode from one mount
point to another into delmntque() and insmntque() which does just
what the names say.
Fix delmntque() to set vp->v_mount to NULL while holding the
mountpoint lock.
FAT32 filesystems to be mounted, subject to some fairly serious limitations.
This works by extending the internal pseudo-inode-numbers generated from
the file's starting cluster number to 64-bits, then creating a table
mapping these into arbitrary 32-bit inode numbers, which can fit in
struct dirent's d_fileno and struct vattr's va_fileid fields. The mappings
do not persist across unmounts or reboots, so it's not possible to export
these filesystems through NFS. The mapping table may grow to be rather
large, and may grow large enough to exhaust kernel memory on filesystems
with millions of files.
Don't enable this option unless you understand the consequences.
waiting for the socket to connect and use msleep() on the socket
mute rather than tsleep(). Acquire socket buffer mutexes around
read-modify-write of socket buffer flags.
depending on namespace pollution in <sys/vnode.h> for the definition
of mutex interfaces used in SOCKBUF_*LOCK().
Sorted includes.
Removed unused includes.
rwatson_netperf:
Introduce conditional locking of the socket buffer in fifofs kqueue
filters; KNOTE() will be called holding the socket buffer locks in
fifofs, but sometimes the kqueue() system call will poll using the
same entry point without holding the socket buffer lock.
Introduce conditional locking of the socket buffer in the socket
kqueue filters; KNOTE() will be called holding the socket buffer
locks in the socket code, but sometimes the kqueue() system call
will poll using the same entry points without holding the socket
buffer lock.
Simplify the logic in sodisconnect() since we no longer need spls.
NOTE: To remove conditional locking in the kqueue filters, it would
make sense to use a separate kqueue API entry into the socket/fifo
code when calling from the kqueue() system call.
- Lock down low hanging fruit use of sb_flags with socket buffer
lock.
- Lock down low hanging fruit use of so_state with socket lock.
- Lock down low hanging fruit use of so_options.
- Lock down low-hanging fruit use of sb_lowwat and sb_hiwat with
socket buffer lock.
- Annotate situations in which we unlock the socket lock and then
grab the receive socket buffer lock, which are currently actually
the same lock. Depending on how we want to play our cards, we
may want to coallesce these lock uses to reduce overhead.
- Convert a if()->panic() into a KASSERT relating to so_state in
soaccept().
- Remove a number of splnet()/splx() references.
More complex merging of socket and socket buffer locking to
follow.
The big lines are:
NODEV -> NULL
NOUDEV -> NODEV
udev_t -> dev_t
udev2dev() -> findcdev()
Various minor adjustments including handling of userland access to kernel
space struct cdev etc.
flags relating to several aspects of socket functionality. This change
breaks out several bits relating to send and receive operation into a
new per-socket buffer field, sb_state, in order to facilitate locking.
This is required because, in order to provide more granular locking of
sockets, different state fields have different locking properties. The
following fields are moved to sb_state:
SS_CANTRCVMORE (so_state)
SS_CANTSENDMORE (so_state)
SS_RCVATMARK (so_state)
Rename respectively to:
SBS_CANTRCVMORE (so_rcv.sb_state)
SBS_CANTSENDMORE (so_snd.sb_state)
SBS_RCVATMARK (so_rcv.sb_state)
This facilitates locking by isolating fields to be located with other
identically locked fields, and permits greater granularity in socket
locking by avoiding storing fields with different locking semantics in
the same short (avoiding locking conflicts). In the future, we may
wish to coallesce sb_state and sb_flags; for the time being I leave
them separate and there is no additional memory overhead due to the
packing/alignment of shorts in the socket buffer structure.
them to behave the same as if the SS_NBIO socket flag had been set
for this call. The SS_NBIO flag for ordinary sockets is set by
fcntl(fd, F_SETFL, O_NONBLOCK).
Pass the MSG_NBIO flag to the soreceive() and sosend() calls in
fifo_read() and fifo_write() instead of frobbing the SS_NBIO flag
on the underlying socket for each I/O operation. The O_NONBLOCK
flag is a property of the descriptor, and unlike ordinary sockets,
fifos may be referenced by multiple descriptors.
to avoid lock order problems when manipulating the sockets associated
with the fifo.
Minor optimization of a couple of calls to fifo_cleanup() from
fifo_open().
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@
1. This check if wrong, because it is true by default
(kern.ps_argsopen is 1 by default) (p_cansee() is not even checked).
2. Sysctl kern.ps_argsopen is going away.
and consume that interface in portalfs and fifofs instead. In the
new world order, unp_connect2() assumes that the unpcb mutex is
held, whereas uipc_connect2() validates that the passed sockets are
UNIX domain sockets, then grabs the mutex.
NB: the portalfs and fifofs code gets down and dirty with UNIX domain
sockets. Maybe this is a bad thing.
stuff was here (NFS) was fixed by Alfred in November. The only remaining
consumer of the stub functions was umapfs, which is horribly horribly
broken. It has missed out on about the last 5 years worth of maintenence
that was done on nullfs (from which umapfs is derived). It needs major
work to bring it up to date with the vnode locking protocol. umapfs really
needs to find a caretaker to bring it into the 21st century.
Functions GC'ed:
vop_noislocked, vop_nolock, vop_nounlock, vop_sharedlock.
255; USB keychains exist that use 256 as the number of heads. This
check has also been removed in Darwin (along with most of the other
head/sector sanity checks).
were a rather overwhelming task. I soon learned that if you don't know
where you're going to store something, at least try to pile it next to
something slightly related in the hope that a pattern emerges.
Apply the same principle to the ffs/snapshot/softupdates code which have
leaked into specfs: Add yet a buf-quasi-method and call it from the
only two places I can see it can make a difference and implement the
magic in ffs_softdep.c where it belongs.
It's not pretty, but at least it's one less layer violated.
functions in kern_socket.c.
Rename the "canwait" field to "mflags" and pass M_WAITOK and M_NOWAIT
in from the caller context rather than "1" or "0".
Correct mflags pass into mac_init_socket() from previous commit to not
include M_ZERO.
Submitted by: sam
by 1 u_int if the number of clusters was 1 more than a multiple of
(8 * sizeof(u_int)). The bitmap is malloced and large (often huge), so
fatal overrun probably only occurred if the number of clusters was 1
more than 1 multiple of PAGE_SIZE/8.
This is what we came here for: Hang dev_t's from their cdevsw,
refcount cdevsw and dev_t and generally keep track of things a lot
better than we used to:
Hold a cdevsw reference around all entrances into the device driver,
this will be necessary to safely determine when we can unload driver
code.
Hold a dev_t reference while the device is open.
KASSERT that we do not enter the driver on a non-referenced dev_t.
Remove old D_NAG code, anonymous dev_t's are not a problem now.
When destroy_dev() is called on a referenced dev_t, move it to
dead_cdevsw's list. When the refcount drops, free it.
Check that cdevsw->d_version is correct. If not, set all methods
to the dead_*() methods to prevent entrance into driver. Print
warning on console to this effect. The device driver may still
explode if it is also incompatible with newbus, but in that case
we probably didn't get this far in the first place.
Remove the unused second argument from udev2dev().
Convert all remaining users of makedev() to use udev2dev(). The
semantic difference is that udev2dev() will only locate a pre-existing
dev_t, it will not line makedev() create a new one.
Apart from the tiny well controlled windown in D_PSEUDO drivers,
there should no longer be any "anonymous" dev_t's in the system
now, only dev_t's created with make_dev() and make_dev_alias()
Introduce d_version field in struct cdevsw, this must always be
initialized to D_VERSION.
Flip sense of D_NOGIANT flag to D_NEEDGIANT, this involves removing
four D_NOGIANT flags and adding 145 D_NEEDGIANT flags.
to size_t *, which is incorrect because they may have different widths.
This caused some subtle forms of corruption, the mostly frequently
reported one being that the last character of a filename was sometimes
duplicated on amd64.
it means that the correct value is unknown. Since this value is just
a hint to improve performance, initially assume that the first non-reserved
cluster is free, then correct this assumption if necessary before writing
the FSInfo block back to disk.
PR: 62826
MFC after: 2 weeks
- don't unlock the vnode after vinvalbuf() only to have to relock it
almost immediately.
- don't refer to devices classified by vn_isdisk() as block devices.
created with the same name, and vice versa:
- Immediately recycle vnodes of files & directories that have been deleted
or renamed.
- When looking an entry in the VFS name cache or smbfs's private
cache, make sure the vnode type is consistent with the type of file
the server thinks it is, and re-create the vnode if it isn't.
The alternative to this is to recycle vnodes unconditionally when their
use count drops to 0, but this would make all the caching we do
mostly useless.
PR: 62342
MFC after: 2 weeks
- 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
file has been removed, it should be purged from the cache, but it need
not be removed from the directory stack causing corruption; instead,
it will simply be removed once the last references and holds on it
are dropped at the end of the unlink/rmdir system calls, and the
normal !UN_CACHED VOP_INACTIVE() handler for unionfs finishes it off.
This is easily reproduced by repeated "echo >file; rm file" on a
unionfs mount. Strangely, "echo -n >file; rm file" didn't make
it happen.
(msdosfs uses normal 8-char indentation almost everywhere else),
too-long lines, and minor English usage errors. The verbose formal
comment before the new function is still abnormal.
(mainly unsorting). There were no changes related to the dirty flag
here. The reference NetBSD implementation put msdosfs_advlock() in a
different place. This commit only moves its declarations and changes
some of the function body to be like the NetBSD version.
disposing fifo resources in fifo_cleanup() instead using of
"vp->v_usecount == 1". There may be other references to the vnode, for
instance by nullfs, at the time fifo_open() or fifo_close() is called,
which could cause a resource leak.
Don't bother grabbing the vnode interlock in fifo_cleanup() since it no
longer accesses v_usecount.
vnode of the parent. However, this check should not be performed if
the lookup failed. This change should fix "union_lookup returning
. not same as startdir" panics people were seeing. The bug was
introduced by an incomplete import of a NetBSD delta in rev 1.38.
- Move the aforementioned check out from DIAGNOSTIC. Performance
is the least of our unionfs worries.
- Minor reorganization.
PR: 53004
MFC after: 1 week
in various kernel objects to represent security data, we embed a
(struct label *) pointer, which now references labels allocated using
a UMA zone (mac_label.c). This allows the size and shape of struct
label to be varied without changing the size and shape of these kernel
objects, which become part of the frozen ABI with 5-STABLE. This opens
the door for boot-time selection of the number of label slots, and hence
changes to the bound on the number of simultaneous labeled policies
at boot-time instead of compile-time. This also makes it easier to
embed label references in new objects as required for locking/caching
with fine-grained network stack locking, such as inpcb structures.
This change also moves us further in the direction of hiding the
structure of kernel objects from MAC policy modules, not to mention
dramatically reducing the number of '&' symbols appearing in both the
MAC Framework and MAC policy modules, and improving readability.
While this results in minimal performance change with MAC enabled, it
will observably shrink the size of a number of critical kernel data
structures for the !MAC case, and should have a small (but measurable)
performance benefit (i.e., struct vnode, struct socket) do to memory
conservation and reduced cost of zeroing memory.
NOTE: Users of MAC must recompile their kernel and all MAC modules as a
result of this change. Because this is an API change, third party
MAC modules will also need to be updated to make less use of the '&'
symbol.
Suggestions from: bmilekic
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
a resource leak. Move the resource deallocation code from fifo_close()
to a new function, fifo_cleanup(), and call fifo_cleanup() from
fifo_close() and the appropriate places in fifo_open().
Tested by: Lukas Ertl
Pointy hat to: truckman
thread being waken up. The thread waken up can run at a priority as
high as after tsleep().
- Replace selwakeup()s with selwakeuppri()s and pass appropriate
priorities.
- Add cv_broadcastpri() which raises the priority of the broadcast
threads. Used by selwakeuppri() if collision occurs.
Not objected in: -arch, -current
Introduce two new macros MNT_ILOCK(mp)/MNT_IUNLOCK(mp) to
operate on this mutex transparently.
Eventually new mutex will be protecting more fields in
struct mount, not only vnode list.
Discussed with: jeff
wasn't curthread, i.e. when we receive a thread pointer to use
as a function argument. Use VOP_UNLOCK/vrele in these cases.
The only case there td != curthread known at the moment is
boot() calling sync with thread0 pointer.
This fixes the panic on shutdown people have reported.
pick up the DEVFS inode number from the dev_t and find our directory
entry from that, we don't need to scan the directory to find it.
This also solves an issue with on-demand devices in subdirectories.
Submitted by: cognet
passes the fdidx from VOP_OPEN down.
This is for all I know the final API for this functionality, but
the locking semantics for messing with the filedescriptor from
the device driver are not settled at this time.
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.
validating the offset within a given memory buffer before handing the
real work off to uiomove(9).
Use uiomove_frombuf in procfs to correct several issues with
integer arithmetic that could result in underflows/overflows. As a
side-effect, the code is significantly simplified.
Add additional sanity checks when computing a memory allocation size
in pfs_read.
Submitted by: rwatson (original uiomove_frombuf -- bugs are mine :-)
Reported by: Joost Pol <joost@pine.nl> (integer underflows/overflows)
file for vnode mappings. Note that this uses vn_fullpath() and may
be somewhat unreliable, although not too unreliable for shared
libraries. For non-vnode mappings, just print "-" for the field.
Obtained from: TrustedBSD Projects
Sponsored by: DARPA, AFRL, Network Associates Laboratories
struct msdosfsmount so that this file has the same prerequisites as
it used to. The new prerequistite was a meta-style bug. It required
many style bugs (unsorted includes ...) elsewhere.
Formatted prototypes in KNF. Resisted urge to sort all the prototypes,
to minimise differences with NetBSD. (NetBSD has reformatted the
prototypes but has not sorted them and still uses __P(()).)
are allowed by Windows (ref: MS KB article 120138).
XXX From my reading of the CIFS specification, it's not clear that
clients need to validate filenames at all.
PR: 57123
Submitted by: Paul Coucher
MFC after: 1 month
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.
FIDs to be 128-bits wide and adds support for realms.
Add a new CODA_COMPAT_5 option, which requests support for the old
Coda 5.x interface instead of the new one.
Create a new coda5.ko module that supports the 5.x interface, and make
the existing coda.ko module use the new 6.x interface. These modules
cannot both be loaded at the same time.
Obtained from: Jan Harkes & the coda-6.0.2 distribution,
NetBSD (drochner) (CODA_COMPAT_5 option).
32K pages are selected. In spec_getpages() change the printf format
specifier and add an explicit cast so that we always print the field
as a long type.
also fixes pfs_access() since it relies on VOP_GETATTR() which will call
pfs_getattr(). This prevents jailed processes from discovering the
existence, start time and ownership of processes outside the jail.
PR: kern/48156
directories. Previously, pfs_iterate() would return -1 when it
reached the end of the process list while processing a process
directory node, even if the parent directory contained further nodes
(which is the case for the linprocfs root directory, where the process
directory node is actually first in the list). With this patch,
pfs_iterate() will continue to traverse the parent directory's node
list after exhausting the process list (as was the intention all
along). The code should hopefully be easier to read as well.
While I'm here, have pfs_iterate() assert that the allproc lock is
held.
masks for files and directories. This should make some
of the Midnight Commander users happy.
Remove an extra ')' in the manual page.
PR: 35699
Submitted by: Eugene Grosbein <eugen@grosbein.pp.ru> (original version)
Tested by: simon
contain the filedescriptor number on opens from userland.
The index is used rather than a "struct file *" since it conveys a bit
more information, which may be useful to in particular fdescfs and /dev/fd/*
For now pass -1 all over the place.
in ntfs_writentvattr_plain and ntfs_readntvattr_plain, and purge the boot
block from the buffer cache if isn't exactly one cluster long. These two
changes work around the same buffer cache bug that ntfs_subr.c 1.30 tried
to, but in a different way. This may decrease throughput by reading smaller
amounts of data from the disk at a time, but may increase it by avoiding
bogus writes of clean buffers.
Problem (re)reported by Karel J. Bosschaart on -current.
the user requests a read-only mount. This is necessary because we
don't do the VOP_OPEN again if they upgrade a read-only mount to
read-write.
Fixes lockup when creating files on msdosfs mounts that have been
mounted read-only then upgraded to read-write. The exact cause of
the lockup is not known, but it is likely to be the kernel getting
stuck in an infinite loop trying to write dirty buffers to a device
without write permission.
Reported/tested by andreas, discussed with phk.
an MSDOSFS file system either failed, silently corrupted the file, or
sometimes corrupted the neighboring file.
PR: 53695
Submitted by: Ariff Abdullah <skywizard@MyBSD.org.my> (original version)
MFC: 3 days
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.
- Avoid calling bread() with different sizes on the same blkno.
Although the buffer cache is designed to handle differing size
buffers, it erroneously tries to write the incorrectly-sized buffer
buffer back to disk before reading the correctly-sized one, even
when it's not dirty. This behaviour caused a panic for read-only
NTFS mounts when INVARIANTS was enabled ("bundirty: buffer x still
on queue y"), reported by NAKAJI Hiroyuki.
- Fix a bug in the code handling holes: a variable was incremented
instead of decremented, which could cause an infinite loop.
smbfs_close(). This fixes paging to and from mmap()'d regions of smbfs
files after the descriptor has been closed, and makes thttpd, GNU ld,
and perhaps more things work that depend on being able to do this.
PR: 48291
- Emulate lock draining (LK_DRAIN) in null_lock() to avoid deadlocks
when the vnode is being recycled.
- Don't allow null_nodeget() to return a nullfs vnode from the wrong
mount when multiple nullfs's are mounted. It's unclear why these checks
were removed in null_subr.c 1.35, but they are definitely necessary.
Without the checks, trying to unmount a nullfs mount will erroneously
return EBUSY, and forcibly unmounting with -f will cause a panic.
- Bump LOG2_SIZEVNODE up to 8, since vnodes are >256 bytes now. The old
value (7) didn't cause any problems, but made the hash algorithm
suboptimal.
These changes fix nullfs enough that a parallel buildworld succeeds.
Submitted by: tegge (partially; LK_DRAIN)
Tested by: kris
resource deallocation back to fifo_close(). This eliminates any
stale data that might be stuck in the socket buffers after all the
readers and writers have closed the fifo.
Tested by: Thorsten Schroeder <ths@katjusha.de>
directory vnodes use to refer to their constituent vnodes, into
union_dircache_free(). Also s/union_dircache/union_dircache_get/ and
tweak the structure of union_dircache_r().
MFC after: 3 days
in smb_fphelp(): the parent vnode may have already been recycled
since we don't hold a reference to it. Fixes a panic when rebooting
with mdconfig -t vnode devices referring to vnodes on a smbfs mount.
been tested extensively, but -CURRENT testing has been hampered by a
number of panics that also occur without the patch. Since the
destabilizing changes between 4.X and 5.X are external to unionfs,
I believe this patch applies equally well to both.
Thanks to scrappy for assistance testing these and other changes.
MFC after: 4 days
Restructure the error handling portion of the resource allocation
code to eliminate duplicated code.
Test for the O_NONBLOCK && fi_readers == 0 case before incrementing
fi_writers and modifying the the socket flag to avoid having to
undo these operations in this error case.
Restructure and simplify the code that handles blocking opens.
There should be no change to functionality.
Sleep on the vnode interlock while waiting for another
caller to increment fi_readers or fi_writers. Hold the
vnode interlock while incrementing fi_readers or fi_writers
to prevent a wakeup from being missed.
Only access fi_readers and fi_writers while holding the vnode
lock. Previously fifo_close() decremented their values without
holding a lock.
Move resource deallocation from fifo_close() to fifo_inactive(),
which allows the VOP_CLOSE() call in the error return path in
fifo_open() to be removed. Fifo_open() was calling VOP_CLOSE()
with the vnode lock held, in violation the current vnode locking
API. Also the way fifo_close() used vrefcnt() to decide whether
to deallocate resources was bogus according to comments in the
vrefcnt() implementation.
Reviewed by: bde
entering sys_process.c debugging primitives, or we violate assertions.
Also, be more careful about releasing the process lock around calls
to uiomove() which may sleep waiting for paging machinations or
related notions. We may want to defer the uiomove() in at least
one case, but jhb will look into that at a later date.
Reported by: Philippe Charnier <charnier@xp11.frmug.org>
Reviewed by: jhb
uptime. Where necessary, convert it back to Unix time by adding boottime
to it. This fixes a potential problem in the accounting code, which would
compute the elapsed time incorrectly if the Unix time was stepped during
the lifetime of the process.
race where a thread could assume that a process was swapped in by
PHOLD() when it actually wasn't fully swapped in yet.
- In faultin(), always msleep() if PS_SWAPPINGIN is set instead of doing
this check after bumping p_lock in the PS_INMEM == 0 case. Also,
sched_lock is only needed for setting and clearning swapping PS_*
flags and the swap thread inhibitor.
- Don't set and clear the thread swap inhibitor in the same loops as the
pmap_swapin/out_thread() since we have to do it under sched_lock.
Instead, mimic the treatment of the PS_INMEM flag and use separate loops
to set the inhibitors when clearing PS_INMEM and clear the inhibitors
when setting PS_INMEM.
- swapout() now returns with the proc lock held as it holds the lock
while adjusting the swapping-related PS_* flags so that the proc lock
can be used to test those flags.
- Only use the proc lock to check the swapping-related PS_* flags in
several places.
- faultin() no longer requires sched_lock to be held by callers.
- Rename PS_SWAPPING to PS_SWAPPINGOUT to be less ambiguous now that we
have PS_SWAPPINGIN.
printed out needs a prefix such as when a thread is blocked on a lock.
- Use another local variable to close another race for the td_wmesg and
td_wchan members of struct thread.
