locks the mount point directory while waiting for vfs_busy to clear.
Meanwhile the unmount which holds the vfs_busy lock tried to lock
the mount point vnode. The fix is to observe that it is safe for the
unmount to remove the vnode from the mount point without locking it.
The lookup will wait for the unmount to complete, then recheck the
mount point when the vfs_busy lock clears.
Sponsored by: DARPA & NAI Labs.
that works in the new threaded kernel. It was commented out of
the disksort routine earlier this year for the reasons given in
kern/subr_disklabel.c (which is where this code used to reside
before it moved to kern/subr_disk.c):
----------------------------
revision 1.65
date: 2002/04/22 06:53:20; author: phk; state: Exp; lines: +5 -0
Comment out Kirks io-request priority hack until we can do this in a
civilized way which doesn't cause grief.
The problem is that it is not generally safe to cast a "struct bio
*" to a "struct buf *". Things like ccd, vinum, ata-raid and GEOM
constructs bio's which are not entrails of a struct buf.
Also, curthread may or may not have anything to do with the I/O request
at hand.
The correct solution can either be to tag struct bio's with a
priority derived from the requesting threads nice and have disksort
act on this field, this wouldn't address the "silly-seek syndrome"
where two equal processes bang the diskheads from one edge to the
other of the disk repeatedly.
Alternatively, and probably better: a sleep should be introduced
either at the time the I/O is requested or at the time it is completed
where we can be sure to sleep in the right thread.
The sleep also needs to be in constant timeunits, 1/hz can be practicaly
any sub-second size, at high HZ the current code practically doesn't
do anything.
----------------------------
As suggested in this comment, it is no longer located in the disk sort
routine, but rather now resides in spec_strategy where the disk operations
are being queued by the thread that is associated with the process that
is really requesting the I/O. At that point, the disk queues are not
visible, so the I/O for positively niced processes is always slowed
down whether or not there is other activity on the disk.
On the issue of scaling HZ, I believe that the current scheme is
better than using a fixed quantum of time. As machines and I/O
subsystems get faster, the resolution on the clock also rises.
So, ten years from now we will be slowing things down for shorter
periods of time, but the proportional effect on the system will
be about the same as it is today. So, I view this as a feature
rather than a drawback. Hence this patch sticks with using HZ.
Sponsored by: DARPA & NAI Labs.
Reviewed by: Poul-Henning Kamp <phk@critter.freebsd.dk>
revert to checking the name to determine if our root device is a ramdisk,
md(4) specifically to determine if we should attempt the root-mount RW
Sponsored by: DARPA & NAI Labs.
contents. The code was subtracting two unsigned ints, stored the
result in a log and expected it to be the same as of a signed
subtraction; this does only work on platforms where int and long
have the same size (due to overflows).
Instead, cast to long before the subtraction; the numbers are
guaranteed to be small enough so that there will be no overflows
because of that.
as sparc64/sparc64/dump_machdep.c a while back).
Other than ia64 (which uses ELF), sparc64 uses a homegrown format for
the dumps (headers are required because the physical address and size of
the tsb must be noted, and because physical memory may be discontiguous);
ELF would not offer any advantages here.
Reviewed by: jake
compile fail. MAC_MAX_POLICIES should always be defined, or we have
bigger problems at hand.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
This is for the not-quite-ready signal/fpu abi stuff. It may not see
the light of day, but I'm certainly not going to be able to validate it
when getting shot in the foot due to syscall number conflicts.
caller to indicate that MAC checks are not required for the lookup.
Similar to IO_NOMACCHECK for vn_rdwr(), this indicates that the caller
has already performed all required protections and that this is an
internally generated operation. This will be used by the NFS server
code, as we don't currently enforce MAC protections against requests
delivered via NFS.
While here, add NOCROSSMOUNT to PARAMASK; apparently this was used at
one point for name lookup flag checking, but isn't any longer or it
would have triggered from the NFS server code passing it to indicate
that mountpoints shouldn't be crossed in lookups.
Approved by: re
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
execve_secure() system call, which permits a process to pass in a label
for a label change during exec. This permits SELinux to change the
label for the resulting exec without a race following a manual label
change on the process. Because this interface uses our general purpose
MAC label abstraction, we call it execve_mac(), and wrap our port of
SELinux's execve_secure() around it with appropriate sid mappings.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
unregister. Under some obscure (perhaps demented) circumstances,
this can result in a panic if a policy is unregistered, and then someone
foolishly unregisters it again.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
creation, deletion, and rename. There are one or two other stray
cases I'll catch in follow-up commits (such as unix domain socket
creation); this permits MAC policy modules to limit the ability to
perform these operations based on existing UNIX credential / vnode
attributes, extended attributes, and security labels. In the rename
case using MAC, we now have to lock the from directory and file
vnodes for the MAC check, but this is done only in the MAC case,
and the locks are immediately released so that the remainder of the
rename implementation remains the same. Because the create check
takes a vattr to know object type information, we now initialize
additional fields in the VATTR passed to VOP_SYMLINK() in the MAC
case.
Approved by: re
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
The primary reason for this is to allow MD code to process machine
specific attributes, segments or sections in the ELF file and
update machine specific state accordingly. An immediate use of this
is in the ia64 port where unwind information is updated to allow
debugging and tracing in/across modules. Note that this commit
does not add the functionality to the ia64 port. See revision 1.9
of ia64/ia64/elf_machdep.c.
Validated on: alpha, i386, ia64
link_elf_init(), link_elf_link_preload_finish() and
link_elf_load_file() to link_elf_link_common_finish().
Since link_elf_init() did initializations as a side-effect
of doing the common actions, keep the initialization in
that function. Consequently, link_elf_add_gdb() is now also
called to insert the very first link_map() (ie the kernel).
Move link_elf_add_gdb(), link_elf_delete_gdb() and link_elf_error()
near the top of the file. The *_gdb() functions are moved inside
the #ifdef DDB already present there.
cannot allocate ef->object, we freed ef before bailing out with
an error. This is wrong because ef=lf and when we have an error
and lf is non-NULL (which holds if we try to alloc ef->object),
we free lf and thus ef as part of the bailing-out.
to help clean up. After selecting a potential buffer to write, this
patch has it acquire a lock on the vnode that owns the buffer before
trying to write it. The vnode lock is necessary to avoid a race with
some other process holding the vnode locked and trying to flush its
dirty buffers. In particular, if the vnode in question is a snapshot
file, then the race can lead to a deadlock. To avoid slowing down the
buf_daemon, it does a non-blocking lock request when trying to lock
the vnode. If it fails to get the lock it skips over the buffer and
continues down its queue looking for buffers to flush.
Sponsored by: DARPA & NAI Labs.
(sizeof(destination_buffer) - 1) bytes into the destination buffer.
This was not harmful because they currently both provide space for
(MAXCOMLEN + 1) bytes.
linked in the kernel. When this condition is detected deep in the linker
internals the EEXIST error code that's returned is stomped on and instead
an ENOEXEC code is returned. This makes apps like sysinstall bitch.
the path including the terminating NUL character from
`struct sockaddr_un' rather than SOCK_MAXADDRLEN bytes.
- Use strlcpy() instead of strncpy() to copy strings.
contiguous space was being allocated from the clust_map
instead of the mbuf_map as the comments indicated. This resulted in
some address space wastage in mbuf_map.
Submitted by: Rohit Jalan <rohjal@yahoo.co.in>
o instead of a list of mbufs use a list of m_tag structures a la openbsd
o for netgraph et. al. extend the stock openbsd m_tag to include a 32-bit
ABI/module number cookie
o for openbsd compatibility define a well-known cookie MTAG_ABI_COMPAT and
use this in defining openbsd-compatible m_tag_find and m_tag_get routines
o rewrite KAME use of aux mbufs in terms of packet tags
o eliminate the most heavily used aux mbufs by adding an additional struct
inpcb parameter to ip_output and ip6_output to allow the IPsec code to
locate the security policy to apply to outbound packets
o bump __FreeBSD_version so code can be conditionalized
o fixup ipfilter's call to ip_output based on __FreeBSD_version
Reviewed by: julian, luigi (silent), -arch, -net, darren
Approved by: julian, silence from everyone else
Obtained from: openbsd (mostly)
MFC after: 1 month
Ignoring a NULL dev in device_set_ivars() sounds wrong, KASSERT it to
non-NULL instead.
Do the same for device_get_ivars() for reasons of symmetry, though
it probably would have yielded a panic anyway, this gives more precise
diagnostics.
Absentmindedly nodded OK to by: jhb
were improperly relocated due to faulty logic in lookup_fdesc()
in elf_machdep.c. The symbol index (symidx) was bogusly used for
load modules other than the one the relocation applied to. This
resulted in bogus bindings and consequently runtime failures.
The fix is to use the symbol index only for the module being
relocated and to use the symbol name for look-ups in the
modules in the dependent list. As such, we need a function to
return the symbol name given the linker file and symbol index.
processes forked with RFTHREAD.
- Use a goto to a label for common code when exiting from fork1() in case
of an error.
- Move the RFTHREAD linkage setup code later in fork since the ppeers_lock
cannot be locked while holding a proc lock. Handle the race of a task
leader exiting and killing its peers while a peer is forking a new child.
In that case, go ahead and let the peer process proceed normally as the
parent is about to kill it. However, the task leader may have already
gone to sleep to wait for the peers to die, so the new child process may
not receive a SIGKILL from the task leader. Rather than try to destruct
the new child process, just go ahead and send it a SIGKILL directly and
add it to the p_peers list. This ensures that the task leader will wait
until both the peer process doing the fork() and the new child process
have received their KILL signals and exited.
Discussed with: truckman (earlier versions)
It must be removed because it is done without the pipe being locked
via pipelock() and therefore is vulnerable to races with pipespace()
erroneously triggering it by temporarily zero'ing out the structure
backing the pipe.
It looks as if this assertion is not needed because all manipulation
of the data changed by pipespace() _is_ protected by pipelock().
Reported by: kris, mckusick