writable tracks on session opening. Note that this an optionally implemented
feature and thus no error will be generated if it fails; the drive will most
likely autorepair it.
of when working deep into the directory tree it can reliably be reget and
marked correctly as the FS root.
Fixed pwd(1) lock panic and possible endless loop in other tools.
#include "opt_quota.h" which do exactly nothing. Speeds up kernel
compilation by 1.375*10^-20001 seconds. But leave the most moxious
comment in msdosfs_vfsops untouched.
1) Enhance write speed significantly on RMW media like CD-RW, DVD-RW but also
on the DVD+RW and all other ECC blocked media. Significant speedups of access
to the device for say compilation on the DVD. Streaming copy is also still at
maximum speed though vast amounts of directory copy work can show side effects
that appear it to slow down but are actually logical when you consider that
most small files are embedded into the descriptors itself.
2) explicit wait for the created RMW thread to spinup
for now since its a lot slower than `rmw' access.
For archs that have trouble with `rmw' for whatever reason can so use it as a
scapegoat to allways mount savely rdonly though slower.
likely due to the file system being full).
Otherwise we'd fail in VOP_PUTPAGES(), which might not happen during
VOP_WRITE(), thus giving the caller the wrong impression that
writing was succesful.
default case of ptyfs mounted under /dev/pts as any chroot would get
/%d as slave names. This allows null mounts of ptyfs to work.
To allow pty allocation from within chroots, either no ptyfs must be
mounted or a null mount exist.
old somewhat naive selection scheme that didn't allow different allocation
settings for nodes, directory information (FIDs) and data.
Also fix some curious side-effects of atime updates on RMW devices.
it could result in theory result in descriptor trashing.
On the performance side, it would try to fixup *every* descriptor even if
it wasn't an internally allocated one. Performance loss wasn't that big but
every bit helps.
preliminary Metadata partition write support but its disabled still since
its not finished yet and not functioning correctly. All other formats are
checked and should work fine.
improvements of at least 4 times in untarring and roughly 100 to 500 times
on file creation in big directories. Lookup of files was O(n*n) and is now
O(1) even for file creation. Free spaces in the directory are kept in a
seperate list for fast file creation.
The postmark benchmark gives:
UDF old:
pm>set transactions 2000
pm>set number 3000
pm>run
Creating files...Done
Performing transactions..........Done
Deleting files...Done
Time:
1593 seconds total
681 seconds of transactions (2 per second)
Files:
3956 created (2 per second)
Creation alone: 3000 files (4 per second)
Mixed with transactions: 956 files (1 per second)
990 read (1 per second)
1010 appended (1 per second)
3956 deleted (2 per second)
Deletion alone: 2912 files (9 per second)
Mixed with transactions: 1044 files (1 per second)
Data:
5.26 megabytes read (3.38 kilobytes per second)
21.93 megabytes written (14.10 kilobytes per second)
pm>
UDF new:
pm>set transactions 2000
pm>set number 3000
pm>run
Creating files...Done
Performing transactions..........Done
Deleting files...Done
Time:
19 seconds total
3 seconds of transactions (666 per second)
Files:
3956 created (208 per second)
Creation alone: 3000 files (230 per second)
Mixed with transactions: 956 files (318 per second)
990 read (330 per second)
1010 appended (336 per second)
3956 deleted (208 per second)
Deletion alone: 2912 files (970 per second)
Mixed with transactions: 1044 files (348 per second)
Data:
5.26 megabytes read (283.66 kilobytes per second)
21.93 megabytes written (1.15 megabytes per second)
unlock the source directory again on exit. The stub that doesn't allow
cross directory renames for now jumped to the wrong exit point and thus
left a locked directory node that paniced on next locking.
heavily fragmented files.
Also fixing some (rare) allocation bugs and function name streamlining.
Tested on harddisc, CD-RW and CD-R i.e. all three basic backend classes.
corruptions that could take place when overwriting sparse files.
Still one rare corruption possible where blocks are accidentally marked
free, but the cause is not yet found and looking at the pattern it won't
happen in every day use.
the name ".." on a parent path component. To prevent other similar errors,
name length checking is not done but the passed name that shouldn't be
passed is ignored.
detect that the `last_node' variable will be set before used since it can't
parse the semantics of `TAILQ_EMPTY()' that is used as a guard first.
Thanks for H?rvard for finding and reporting it :)
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.
puffs_getvnode() was inserting vnodes into mnt_vnodelist without taking
a reference to the mount for each. When vnodes are scrubbed, refs to the
vnodes mount structure are dropped => boom.
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.
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.
- Add a lot of missing selinit() and seldestroy() calls.
- Merge selwakeup() and selnotify() calls into a single selnotify().
- Add an additional 'events' argument to selnotify() call. It will
indicate which event (POLL_IN, POLL_OUT, etc) happen. If unknown,
zero may be used.
Note: please pass appropriate value of 'events' where possible.
Proposed on: <tech-kern>
