possible future I-cache coherency operation can succeed. On ARM
for example the L1 cache can be (is) virtually mapped, which
means that any I/O that uses temporary mappings will not see the
I-cache made coherent. On ia64 a similar behaviour has been
observed. By flushing the D-cache, execution of binaries backed
by md(4) and/or NFS work reliably.
For Book-E (powerpc), execution over NFS exhibits SIGILL once in
a while as well, though cpu_flush_dcache() hasn't been implemented
yet.
Doing an explicit D-cache flush as part of the non-DMA based I/O
read operation eliminates the need to do it as part of the
I-cache coherency operation itself and as such avoids pessimizing
the DMA-based I/O read operations for which D-cache are already
flushed/invalidated. It also allows future optimizations whereby
the bcopy() followed by the D-cache flush can be integrated in a
single operation, which could be implemented using on-chips DMA
engines, by-passing the D-cache altogether.
filesystem supports additional operations using shared vnode locks.
Currently this is used to enable shared locks for open() and close() of
read-only file descriptors.
- When an ISOPEN namei() request is performed with LOCKSHARED, use a
shared vnode lock for the leaf vnode only if the mount point has the
extended shared flag set.
- Set LOCKSHARED in vn_open_cred() for requests that specify O_RDONLY but
not O_CREAT.
- Use a shared vnode lock around VOP_CLOSE() if the file was opened with
O_RDONLY and the mountpoint has the extended shared flag set.
- Adjust md(4) to upgrade the vnode lock on the vnode it gets back from
vn_open() since it now may only have a shared vnode lock.
- Don't enable shared vnode locks on FIFO vnodes in ZFS and UFS since
FIFO's require exclusive vnode locks for their open() and close()
routines. (My recent MPSAFE patches for UDF and cd9660 already included
this change.)
- Enable extended shared operations on UFS, cd9660, and UDF.
Submitted by: ups
Reviewed by: pjd (ZFS bits)
MFC after: 1 month
result in panic:
mdconfig -af blah.img -o force
mount /dev/md0 /mnt
mdconfig -du 0
Reviewed by: scottl
Approved by: rwatson (mentor)
Sponsored by: FreeBSD Foundation
Even though we got rid of device major numbers some time ago, device
drivers still need to provide unique device minor numbers to make_dev().
These numbers are only used inside the kernel. They are not related to
device major and minor numbers which are visible in devfs. These are
actually based on the inode number of the device.
It would eventually be nice to remove minor numbers entirely, but we
don't want to be too agressive here.
Because the 8-15 bits of the device number field (si_drv0) are still
reserved for the major number, there is no 1:1 mapping of the device
minor and unit numbers. Because this is now unused, remove the
restrictions on these numbers.
The MAXMAJOR definition was actually used for two purposes. It was used
to convert both the userspace and kernelspace device numbers to their
major/minor pair, which is why it is now named UMINORMASK.
minor2unit() and unit2minor() have now become useless. Both minor() and
dev2unit() now serve the same purpose. We should eventually remove some
of them, at least turning them into macro's. If devfs would become
completely minor number unaware, we could consider using si_drv0 directly,
just like si_drv1 and si_drv2.
Approved by: philip (mentor)
This fixes the panic which happens when mdcreate_vnode() calls vn_close()
and mddestroy() calls it again further down the error handling path.
Reviewed by: kris, kib
MFC after: 3 days
conjuction with 'thread' argument passing which is always curthread.
Remove the unuseful extra-argument and pass explicitly curthread to lower
layer functions, when necessary.
KPI results broken by this change, which should affect several ports, so
version bumping and manpage update will be further committed.
Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>
Remove this argument and pass curthread directly to underlying
VOP_LOCK1() VFS method. This modify makes the code cleaner and in
particular remove an annoying dependence helping next lockmgr() cleanup.
KPI results, obviously, changed.
Manpage and FreeBSD_version will be updated through further commits.
As a side note, would be valuable to say that next commits will address
a similar cleanup about VFS methods, in particular vop_lock1 and
vop_unlock.
Tested by: Diego Sardina <siarodx at gmail dot com>,
Andrea Di Pasquale <whyx dot it at gmail dot com>
I've tried to move md(4) to use geom_disk class, like real disks do, but
this requires major rework of some of the existing features such as
configuration dumping for example. Therefore just putting devstat support
directly into md(4) seems to be optimal solution.
Now you can see md(4) stats in `systat -vm' again.
MFC after: 2 weeks
to kproc_xxx as they actually make whole processes.
Thos makes way for us to add REAL kthread_create() and friends
that actually make theads. it turns out that most of these
calls actually end up being moved back to the thread version
when it's added. but we need to make this cosmetic change first.
I'd LOVE to do this rename in 7.0 so that we can eventually MFC the
new kthread_xxx() calls.
- Use thread_lock() rather than sched_lock for per-thread scheduling
sychronization.
- Use the per-process spinlock rather than the sched_lock for per-process
scheduling synchronization.
Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
Change the VOP_OPEN(), vn_open() vnode operation and d_fdopen() cdev operation
argument from being file descriptor index into the pointer to struct file.
Proposed and reviewed by: jhb
Reviewed by: daichi (unionfs)
Approved by: re (kensmith)
by vnode. Allow for md thread and the thread that owns lock on vnode
backing the md device to do the write even when runningbufspace is
exhausted.
Tested by: Peter Holm
Reviewed by: tegge
MFC after: 2 weeks
BIO_READ/BIO_WRITE is sent to vnode-backed provider (BIO_DELETE or
BIO_FLUSH).
Reported by: ceri
Add support for BIO_FLUSH to vnode-backed md(4) devices based on
VOP_FSYNC().
mddestroy() only if the file is from a non-MPSAFE VFS.
- No longer unconditionally hold Giant in the md kthread for vnode-backed
kthreads.
- Improve the handling of the thread exit race when destroying an md
device.
a problem with listing large number of md(4) devices. Either 'list' or
'query' mode uses XML.
Additionally, new functionality was introduced. It's possible to pass
multiple devices to -u:
# ./mdconfig -l -u md0,md1
Approved by: cognet (mentor)
- Prefer '_' to ' ', as it results in more easily parsed results in
memory monitoring tools such as vmstat.
- Remove punctuation that is incompatible with using memory type names
as file names, such as '/' characters.
- Disambiguate some collisions by adding subsystem prefixes to some
memory types.
- Generally prefer lower case to upper case.
- If the same type is defined in multiple architecture directories,
attempt to use the same name in additional cases.
Not all instances were caught in this change, so more work is required to
finish this conversion. Similar changes are required for UMA zone names.
Remove md_mtx.
Remove GIANT from the mdctl device driver and avoid DROP_GIANT,
PICKUP_GIANT and geom events since we can call into GEOM directly
now.
Pick up Giant around vn_close().
Apply an exclusive sx around mdctls ioctl and preloading to protect
lists etc..
Don't initialize our lock (md_mtx or md_sx) from a
SYSINIT when there is a perfectly good pair of _fini/_init
functions to do it from.
Prune any final fractional sector from the mediasize to
keep GEOM happy.
Cleanups:
Unify MDIOVERSION check in (x)mdctlioctl()
Add pointer to start() routine to softc to eliminate a switch{}
Inline guts of mddetach().
Always pass error pointer to mdnew(), simplify implementation.
- Always check mdnew() return value, as even in !autounit case
kthread_create() can fail.
Those two changes fix serval panics provked by simple stress test.
Tested by: Kris The BugMagnet
MFC after: 3 days
by md(4). Before this change, it was possible to by-pass these flags
by creating memory disks which used a file as a backing store and
writing to the device.
This was discussed by the security team, and although this is problematic,
it was decided that it was not critical as we never guarantee that root will
be restricted.
This change implements the following behavior changes:
-If the user specifies the readonly flag, unset write operations before
opening the file. If the FWRITE mask is unset, the device will be
created with the MD_READONLY mask set. (readonly)
-Add a check in g_md_access which checks to see if the MD_READONLY mask
is set, if so return EROFS
-Do not gracefully downgrade access modes without telling the user. Instead
make the user specify their intentions for the device (assuming the file is
read only). This seems like the more correct way to handle things.
This is a RELENG_6 candidate.
PR: kern/84635
Reviewed by: phk
memory disk is larger than the number of available sf_bufs, this improves
performance on SMPs by eliminating interprocessor TLB shootdowns. For
example, with 6656 sf_bufs, the default on my test machine, and a 256MB
swap-backed memory disk, I see the command
"dd if=/dev/md0 of=/dev/null bs=64k" achieve ~489MB/sec with the default,
shared mappings, and ~587MB/sec with CPU private mappings.
in mddestroy() to properly free already allocated memory.
This fixes a panic when we want to create too big memory backed device
with preallocate memory (-o reserve).
- Remove redundant { }.
MFC after: 1 week
show file name for 'mdconfig -l -u <x>' command.
This allows to preserve API/ABI compatibility with version 0 (that's why
I changed version number back to 0) and will allow to merge this change
to RELENG_5.
MFC after: 5 days
md(8). The former is generally not going to fail, but the latter can
fail when the underlying swap device returns an error.
There are still plenty of other places where vm_pager_get_pages() failing
will lead directly to crashes, so it's a good idea to put your swap on
RAID if you care enough to put any of your disks on RAID....
After this change it should be possible to use very big md(4) devices.
- Clean up and simplify the code a bit.
- Use humanize_number(3) to print size of md(4) devices.
- Add 't' suffix which stands for terabyte.
- Make '-S' to really work with all types of devices.
- Other minor changes.
it is only used in one function. While doing so, change its type to
vm_ooffset_t.
We are still limited for swap-backed devices to 16TB on 32-bit architectures
where PAGE_SIZE is 4096 bytes.
