run through copy-on-write. Call fscow_run() with valid data where possible.
The LP_UFSCOW hack is no longer needed to protect ffs_copyonwrite() against
endless recursion.
- Add a flag B_MODIFY to bread(), breada() and breadn(). If set the caller
intends to modify the buffer returned.
- Always run copy-on-write on buffers returned from ffs_balloc().
- Add new function ffs_getblk() that gets a buffer, assigns a new blkno,
may clear the buffer and runs copy-on-write. Process possible errors
from getblk() or fscow_run(). Part of PR kern/38664.
Welcome to 4.99.63
Reviewed by: YAMAMOTO Takashi <yamt@netbsd.org>
and DVD's behave like floppy discs. Writing is supported upto and including
version 2.01; version 2.50 and 2.60 will follow.
Also extending the UDF implementation to support symbolic links and
hardlinks.
Added are the mmcformat(8) tool to format rewritable CD/DVD discs and
newfs_udf(8).
Limitations:
all operations can be performed on the file system though the
sheduling is currently optimised for archiving workloads.
mv(1)/rename(2) is currently only implemented for non-directories.
Make VFS hooks dynamic while we're here and say farewell to VFS_ATTACH and
VFS_HOOKS_ATTACH linksets.
As a consequence, most of the file systems can now be loaded as new style
modules.
Quick sanity check by ad@.
Simplify the mount locking. Remove all the crud to deal with recursion on
the mount lock, and crud to deal with unmount as another weirdo lock.
Hopefully this will once and for all fix the deadlocks with this. With this
commit there are two locks on each mount:
- krwlock_t mnt_unmounting. This is used to prevent unmount across critical
sections like getnewvnode(). It's only ever read locked with rw_tryenter(),
and is only ever write locked in dounmount(). A write hold can't be taken
on this lock if the current LWP could hold a vnode lock.
- kmutex_t mnt_updating. This is taken by threads updating the mount, for
example when going r/o -> r/w, and is only present to serialize updates.
In order to take this lock, a read hold must first be taken on
mnt_unmounting, and the two need to be held across the operation.
One effect of this change: previously if an unmount failed, we would make a
half hearted attempt to back out of it gracefully, but that was unlikely to
work in a lot of cases. Now while an unmount that will be aborted is in
progress, new file operations within the mount will fail instead of being
delayed. That is unlikely to be a problem though, because if the admin
requests unmount of a file system then s(he) has made a decision to deny
access to the resource.
The previous fix worked, but it opened a window where mounts could have
disappeared from mountlist while the caller was traversing it using
vfs_trybusy(). Fix that.
The symptom was that sometimes file systems would occasionally not appear
in output from 'df' or 'mount' if the system was busy. Resolution:
- Make mount locks work somewhat like vm_map locks.
- vfs_trybusy() now only fails if the mount is gone, or if someone is
unmounting the file system. Simple contention on mnt_lock doesn't
cause it to fail.
- vfs_busy() will wait even if the file system is being unmounted.
we no longer need to guard against access from hardware interrupt handlers.
Additionally, if cloning a process with CLONE_SIGHAND, arrange to have the
child process share the parent's lock so that signal state may be kept in
sync. Partially addresses PR kern/37437.
proclist_mutex and proclist_lock into a single adaptive mutex (proc_lock).
Implications:
- Inspecting process state requires thread context, so signals can no longer
be sent from a hardware interrupt handler. Signal activity must be
deferred to a soft interrupt or kthread.
- As the proc state locking is simplified, it's now safe to take exit()
and wait() out from under kernel_lock.
- The system spends less time at IPL_SCHED, and there is less lock activity.
- Socket layer becomes MP safe.
- Unix protocols become MP safe.
- Allows protocol processing interrupts to safely block on locks.
- Fixes a number of race conditions.
With much feedback from matt@ and plunky@.
- Do reference counting for 'struct mount'. Each vnode associated with a
mount takes a reference, and in turn the mount takes a reference to the
vfsops.
- Now that mounts are reference counted, replace the overcomplicated mount
locking inherited from 4.4BSD with a recursable rwlock.
Introduce a per-FS rename lock and new vfsops to manipulate it.
Get this lock while renaming. Also add another relookup() in do_sys_rename,
which is a hack to kludge around some of the worst deficiencies of
ufs_rename.
reviewed-by: pooka (and an earlier rev by ad)
posted on tech-kern with no objections.
shutdown). There are still problems with device access and a PR will be
filed.
- Kill checkalias(). Allow multiple vnodes to reference a single device.
- Don't play dangerous tricks with block vnodes to ensure that only one
vnode can describe a block device. Instead, prohibit concurrent opens of
block devices. As a bonus remove the unreliable code that prevents
multiple file system mounts on the same device. It's no longer needed.
- Track opens by vnode and by device. Issue cdev_close() when the last open
goes away, instead of abusing vnode::v_usecount to tell if the device is
open.
continue. A thread trying to clean out the extant layer vnode needs to
acquire the shared lock (i.e. the lower vnode's lock), which our caller
already holds. To allow the cleaning to succeed the current thread must make
progress. So, for a brief time more than one vnode in a layered file system
may refer to a single vnode in the lower file system.
- Add a KAUTH_PROCESS_SCHEDULER action, to handle scheduler related
requests, and add specific requests for set/get scheduler policy and
set/get scheduler parameters.
- Add a KAUTH_PROCESS_KEVENT_FILTER action, to handle kevent(2) related
requests.
- Add a KAUTH_DEVICE_TTY_STI action to handle requests to TIOCSTI.
- Add requests for the KAUTH_PROCESS_CANSEE action, indicating what
process information is being looked at (entry itself, args, env,
open files).
- Add requests for the KAUTH_PROCESS_RLIMIT action indicating set/get.
- Add requests for the KAUTH_PROCESS_CORENAME action indicating set/get.
- Make bsd44 secmodel code handle the newly added rqeuests appropriately.
All of the above make it possible to issue finer-grained kauth(9) calls in
many places, removing some KAUTH_GENERIC_ISSUSER requests.
- Remove the "CAN" from KAUTH_PROCESS_CAN{KTRACE,PROCFS,PTRACE,SIGNAL}.
Discussed with christos@ and yamt@.
Buffers run through copy-on-write are marked B_COWDONE. This condition
is valid until the buffer has run through bwrite() and gets cleared from
biodone().
Welcome to 4.99.39.
Reviewed by: YAMAMOTO Takashi <yamt@netbsd.org>
The general trend is to remove it from all kernel interfaces and
this is a start. In case the calling lwp is desired, curlwp should
be used.
quick consensus on tech-kern
- Instead of hooking the handler on the specdev of a mounted file system
hook directly on the `struct mount'.
- Rename from `vn_cow_*' to `fscow_*' and move to `kern/vfs_trans.c'. Use
`mount_*specific' instead of clobbering `struct mount' or `struct specinfo'.
- Replace the hand-made reader/writer lock with a krwlock.
- Keep `vn_cow_*' functions and mark as obsolete.
- Welcome to NetBSD 4.99.32 - `struct specinfo' changed size.
Reviewed by: Jason Thorpe <thorpej@netbsd.org>
knew what it was supposed to be used for and wrstuden gave a go-ahead
* while rototilling, convert file systems which went easily to
use VFS_PROTOS() instead of manually prototyping the methods
need to understand the locking around that field. Instead of setting
B_ERROR, set b_error instead. b_error is 'owned' by whoever completes
the I/O request.
need to understand the locking around that field. Instead of setting
B_ERROR, set b_error instead. b_error is 'owned' by whoever completes
the I/O request.
setting vnode sizes, is handled elsewhere: file system vnode creation
or spec_open() for regular files or block special files, respectively.
Add a call to VOP_MMAP() to the pagedvn exec path, since the vnode
is being memory mapped.
reviewed by tech-kern & wrstuden
instead of the result from getcwd(). The works around locking
panics caused by namei calling VOP_READLINK while holding on to a
directory lock and getcwd() trying to acquire that lock. The real
fix would be to get rid of getcwd() calls within VOPs (not locking
safe), but that's not a viable option in the netbsd-4 timeframe.
Suggestion for workaround from David Holland.
fs code is a kernel buffer, pass though the length of the buffer as well.
Since the length of the userspace buffer isn'it (yet) passed through the mount
system call, add a field to the vfsops structure containing the default length.
Split sys_mount() for calls from compat code.
Ride one of the recent kernel version changes - old fs LKMs will load, but
sys_mount() will reject any attempt to use them.
MNT_FORCE is given
* decrease cargo cult index by getting rid of commented sections
with mntflushbuf() in them - AFAICT the call was removed from our
kernel over 13 years ago with the 4.4BSDlite import
an init method. So get rid of it and #ifdef _LKM and just always
init in the init method. Give malloc types the same treatment.
Makes file systems nicer to work with in linksetless environments
and fixes a few LKM discrepancies.
vmspace information fails.
Return the nice value properly to userland via the /proc/<pid>/stat entry.
Use vm sizes from vmspace, rather than rusage structs, for the same
reasons as mentioned previously - see the comment in
kvm_proc.c::kvm_getproc2() about rusage values and zombie processes.
+ in /proc/<pid>/statm emulation, use the memory values from vmspace,
rather than struct rusage, since the rusage values appear to be 0 for
all processes except zombies. cf dsl's comment in
kvm_proc.c::kvm_getproc2()
+ in /proc/<pid>/stat, instead of returning the tv_sec value, return the
number of ticks we've had (roughly equivalent to the Linux jiffies).
Calculate these values from the tv_usec values.
Also:
+ enclose CPU_INFO_ITERATOR and CPU_INFO_FOREACH usage in #ifdef
MULTIPROCESSOR, at the request of Nick Hudson
Together, these changes allow htop to work on NetBSD.
/proc/stat
/proc/loadavg and
/proc/<pid>/statm.
These are only present when -o linux is specified as a mount option
to procfs.
Factor out some common code so that it can be used by a number of
functions.
XXX The values returned in the statm emulation need to be verified.
function that does the work, genfs_do_putpages(), now takes as an argument
a pointer to the page that would be waited on, if PGO_BUSYWAIT were not set.
This allows a consumer, e.g. lfs_putpages(), to perform an action outside
the scope of UVM before sleeping on the page in question.
to skip unnecessary flushing when layered file system vnodes are recycled.
this also prevents a deadlock with the dodgy LFS putpages routine.
fixes the non-LFS part of PR 36150.
corresponding flags.
Revert softdep_trackbufs() to its state before vn_start_write() was added.
Remove from struct mount now unneeded flags IMNT_SUSPEND* and
members mnt_writeopcountupper, mnt_writeopcountlower and mnt_leaf.
Welcome to 4.99.17
write the whole map in one shot so that we don't have to deal with the
map changing under us. Fixes the linux emulated jdk-1.6 where it was
losing the last map entry and could not find the stack on startup.
