With write-allocate cache we get into the following scenario:
1. data has been updated in the memory by the USB HC, but
2. D-cache holds an un-flushed value of it
3. when affected cache line is being replaced, the old (un-flushed) value is
flushed and overwrites the newly arrived
This is possible due to how write-allocate works with virtual caches (ARM for
example).
In case of USB transfers it leads to fatal tags discrepancies in umass(4)
operation, which look like the following:
umass0: Invalid CSW: tag 1 should be 2
(probe0:umass-sim0:0:0:0): Request completed with CAM_REQ_CMP_ERR
(probe0:umass-sim0:0:0:0): Retrying Command
umass0: Invalid CSW: tag 1 should be 3
(probe0:umass-sim0:0:0:0): Request completed with CAM_REQ_CMP_ERR
(probe0:umass-sim0:0:0:0): Retrying Command
umass0: Invalid CSW: tag 1 should be 4
(probe0:umass-sim0:0:0:0): Request completed with CAM_REQ_CMP_ERR
(probe0:umass-sim0:0:0:0): Retrying Command
umass0: Invalid CSW: tag 1 should be 5
(probe0:umass-sim0:0:0:0): Request completed with CAM_REQ_CMP_ERR
(probe0:umass-sim0:0:0:0): Retrying Command
umass0: Invalid CSW: tag 1 should be 6
(probe0:umass-sim0:0:0:0): Request completed with CAM_REQ_CMP_ERR
(probe0:umass-sim0:0:0:0): error 5
(probe0:umass-sim0:0:0:0): Retries Exausted
To eliminate this, a BUS_DMASYNC_PREREAD sync operation is required in
usbd_start_transfer().
Credits for nailing this down go to Grzegorz Bernacki gjb AT semihalf DOT com.
Reviewed by: imp
Approved by: cognet (mentor)
historical relic, and are no longer appropriate for either LAN or WAN
mounting. At modern (gigabit and 10 gigabit) LAN speeds packet loss
from socket buffer fill events is common, and sequence numbers wrap
quickly enough that data corruption is possible. TCP solves both of
these problems without imposing significant overhead.
MFC after: 1 month
sectors so the geometry of large IDE disks has to be adjusted. This
corresponds to what the OpenSolaris dad(7D) driver does except that
the latter only tweaks sectors and effectively limits the mediasize
to 128GB so the cylinders and heads fields won't ever overflow. Not
limiting the mediasize is a compromise between allowing to use Sun
disk label as far as possible and being able to use the entire disk
with another disk label.
This allows to use the full capacity of large IDE disks if they were
not labeled under (Open)Solaris (in both ways of the meaning).
MFC after: 2 weeks
Turn off TFTP support by default: when both TFTP and NFS are enabled in the
loader, strange interactions occur in the pure netbooting scenario (i.e.
loader is TFTP-ed, kernel+world mounted over NFS), leading to very slow access
to the NFS-exported files.
Reviewed by: grehan
Approved by: cognet (mentor)
The logical disks will appear as /dev/lvm/<vol group>-<logical vol>, for
instance /dev/lvm/vg0-home. GLVM currently supports linear stripes with
segments on multiple physical disks. The metadata is read only, logical
volumes can not be allocated or resized.
Reviewed by: Ivan Voras
- Include lock.h in lockmgr.h as nested header in order to safely use
LOCK_FILE and LOCK_LINE. As long as this code will be replaced soon
we can tollerate for a while this namespace pollution even if the real
fix would be to let lockmgr() depend by lock.h as a separate header.
tree, restyle everything but coda.h (which is more explicitly shared
across systems) into a closer approximation to style(9).
Remove a few more unused function prototypes.
Add or clarify some comments.
MFC after: 1 month
NOP-message polling in ciss_periodic().
Note that setting the tunable to non-zero can be workaround only for
`ADAPTER HEARTBEAT FAILED' problem, and may freeze the system w/o
the problem.
Reviewed by: scottl
Reported by: Attila Nagy
MFC after: 3 days
owned by a NULL owner. This will lead consequent VOP_ISLOCKED() present
into nfs_upgrade_vnlock() to panic as it only acquire curthread now.
Fix nfs_upgrade_vnlock() and nfs_downgrade_vnlock() in order to not use
more the struct thread pointer passed as argument (as it is really nomore
required there as vn_lock() and VOP_UNLOCK doesn't get the lock more).
Using curthread, in place, doesn't get ambiguity as LK_EXCLOTHER should
be handled as a "not locked" request by both functions.
Reported by: kris
Tested by: kris
Reviewed by: ups
- Rename print_vattr to coda_print_vattr and make static, rename
print_cred to coda_print_cred.
- Remove unused coda_vop_nop.
- Add XXX comment because coda_readdir forwards to the cache vnode's
readdir rather than venus_readdir, and annotate venus_readdir as
unused.
- Rename vc_nb_* to vc_*.
- Use d_open_t, d_close_t, d_read_t, d_write_t, d_ioctl_t and d_poll_t
for prototyping vc_* as that is the intent, don't use our own
definitions.
- Rename coda_nb_statfs to coda_statfs, rename NB_SFS_SIZ to
CODA_SFS_SIZ.
- Replace one more OBE reference to NetBSD with a reference to FreeBSD.
- Tidy up a little vertical whitespace here and there.
- Annotate coda_nc_zapvnode as unused.
- Remove unused vcodattach.
- Annotate VM_INTR as unused.
- Annotate that coda_fhtovp is unused and doesn't match the FreeBSD
prototype, so isn't hooked up to vfs_fhtovp. If we want NFS export of
Coda to work someday, this needs to be fixed.
- Remove unused getNewVnode.
- Remove unused coda_vget, coda_init, coda_quotactl prototypes.
MFC after: 1 month
the mountpoint for a specific device. This was implemented incorrectly,
a bad idea in a fundamental sense, and also never used, so presumably
a long-idle debugging function.
MFC after: 1 month
for vop_bmap; delete the existing stub that returned either EINVAL
or EOPNOTSUPP, and had unreachable calls to VOP_BMAP on the cache
vnode.
MFC after: 1 month
directory, and jail directory within procstat. While this functionality
is available already in fstat, encapsulating it in the kern.proc.filedesc
sysctl makes it accessible without using kvm and thus without needing
elevated permissions.
The new procstat output looks like:
PID COMM FD T V FLAGS REF OFFSET PRO NAME
76792 tcsh cwd v d -------- - - - /usr/src
76792 tcsh root v d -------- - - - /
76792 tcsh 15 v c rw------ 16 9130 - -
76792 tcsh 16 v c rw------ 16 9130 - -
76792 tcsh 17 v c rw------ 16 9130 - -
76792 tcsh 18 v c rw------ 16 9130 - -
76792 tcsh 19 v c rw------ 16 9130 - -
I am also bumping __FreeBSD_version for this as this new feature will be
used in at least one port.
Reviewed by: rwatson
Approved by: rwatson
then later to FreeBSD. Update various NetBSD-related comments: in some
cases delete them because they don't appply, in others update to say
FreeBSD as they still apply but in FreeBSD (and might for that matter
no longer apply on NetBSD), and flag one case where I'm not sure
whether it applies.
MFC after: 1 month
locks of those vnodes. Probably, Coda should do the same lock sharing/
pass-through that is done for nullfs, but in the mean time this ensures
that locks are adequately held to prevent corruption of data structures
in the cache file system.
Assuming most operations came from the top layer of Coda and weren't
performed directly on the cache vnodes, in practice this corruption was
relatively unlikely as the Coda vnode locks were ensuring exclusive
access for most consumers.
This causes WITNESS to squeal like a pig immediately when Coda is used,
rather than waiting until file close; I noticed these problems because
of the lack of said squealing.
MFC after: 1 month
vget() calls using inode numbers to query the root of /coda, which is not
needed since we now cache the root vnode with the mountpoint.
MFC after: 1 month
VOP_ISLOCKED(arg, curthread). Now, VOP_ISLOCKED() and lockstatus() should
only acquire curthread as argument; this will lead in axing the additional
argument from both functions, making the code cleaner.
Reviewed by: jeff, kib
the provided lock or &blocked_lock. The thread may be temporarily
assigned to the blocked_lock by the scheduler so a direct comparison
can not always be made.
- Use THREAD_LOCKPTR_ASSERT() in the primary consumers of the scheduling
interfaces. The schedulers themselves still use more explicit asserts.
Sponsored by: Nokia
obtained from OpenBSD with an algorithm suggested
by Amit Klein. The OpenBSD algorithm has a few
flaws; see Amit's paper for more information.
For a description of how this algorithm works,
please see the comments within the code.
Note that this commit does not yet enable random IP ID
generation by default. There are still some concerns
that doing so will adversely affect performance.
Reviewed by: rwatson
MFC After: 2 weeks
- Move recursion checking into rwlock inlines to free a bit for use with
adaptive spinners.
- Clear the RW_LOCK_WRITE_SPINNERS flag whenever the lock state changes
causing write spinners to restart their loop.
- Write spinners are limited by a count while readers hold the lock as
there is no way to know for certain whether readers are running still.
- In the read path block if there are write waiters or spinners to avoid
starving writers. Use a new per-thread count, td_rw_rlocks, to skip
starvation avoidance if it might cause a deadlock.
- Remove or change invalid assertions in turnstiles.
Reviewed by: attilio (developed parts of the patch as well)
Sponsored by: Nokia
This support tries to be as parallel as possible with other locking
primitives, but there are differences; more specifically:
- The base witness support is alredy equipped for allowing lock
duplication acquisition as lockmgr rely on this.
- In the case of lockmgr_disown() the lock result unlocked by witness
even if it is still held by the "kernel context"
- In the case of upgrading we can have 3 different situations:
* Total unlocking of the shared lock and nothing else
* Real witness upgrade if the owner is the first upgrader
* Shared unlocking and exclusive locking if the owner is not the first
upgrade but it is still allowed to upgrade
- LK_DRAIN is basically handled like an exclusive acquisition
Additively new options LK_NODUP and LK_NOWITNESS can now be used with
lockinit(): LK_NOWITNESS disables WITNESS for the specified lock while
LK_NODUP enable duplicated locks tracking. This will require manpages
update and a __FreeBSD_version bumping (addressed by further commits).
This patch also fixes a problem occurring if a lockmgr is held in
exclusive mode and the same owner try to acquire it in shared mode:
currently there is a spourious shared locking acquisition while what
we really want is a lock downgrade. Probabilly, this situation can be
better served with a EDEADLK failing errno return.
Side note: first testing on this patch alredy reveleated several LORs
reported, so please expect LORs cascades until resolved. NTFS also is
reported broken by WITNESS introduction. BTW, NTFS is exposing a lock
leak which needs to be fixed, and this patch can help it out if
rightly tweaked.
Tested by: kris, yar, Scot Hetzel <swhetzel at gmail dot com>
done in consumers code: using locks properties is much more appropriate.
Fix current code doing these bogus checks.
Note: Really, callout are not usable by all !(LC_SPINLOCK | LC_SLEEPABLE)
primitives like rmlocks doesn't implement the generic lock layer
functions, but they can be equipped for this, so the check is still
valid.
Tested by: matteo, kris (earlier version)
Reviewed by: jhb
This allows to fix a problem with ARM kernel.bin not having the MFS image
embedded: it is objcopied from the kernel.noheader temporary ELF file, which
was not subject to embedding the MFS image previously.
Reviewed by: imp
Approved by: cognet (mentor)
