journal blocks, instead of hard coding 512 byte sector size. Journal need
to atomically write the block, that can only be guaranteed at the device
sector size, not larger. Attempt to write less then sector size results in
driver errors.
Note that this is the first structure in UFS that depends on the
sector size. Other elements are written in the units of fragments.
In collaboration with: pho
Reviewed by: jeff
Tested by: bz, pho
SU+J is not included as a FEATURE macro:
- it was not in the tree during the GSoC
- I do not see an option to en-/disable it in NOTES
Two minor changes where made during the review compared to what was developed
during GSoC 2010.
No FreeBSD version bump, the userland application to query the features will
be committed last and can serve as an indication of the availablility if
needed.
Sponsored by: Google Summer of Code 2010
Submitted by: kibab
Reviewed by: kib
X-MFC after: to be determined in last commit with code from this project
- entirely eliminate some calls to uio_yeild() as being unnecessary,
such as in a sysctl handler.
- move should_yield() and maybe_yield() to kern_synch.c and move the
prototypes from sys/uio.h to sys/proc.h
- add a slightly more generic kern_yield() that can replace the
functionality of uio_yield().
- replace source uses of uio_yield() with the functional equivalent,
or in some cases do not change the thread priority when switching.
- fix a logic inversion bug in vlrureclaim(), pointed out by bde@.
- instead of using the per-cpu last switched ticks, use a per thread
variable for should_yield(). With PREEMPTION, the only reasonable
use of this is to determine if a lock has been held a long time and
relinquish it. Without PREEMPTION, this is essentially the same as
the per-cpu variable.
should_yield(). Use this in various places. Encapsulate the common
case of check-and-yield into a new function maybe_yield().
Change several checks for a magic number of iterations to use
should_yield() instead.
MFC after: 1 week
it at the allocation time for journaled fs and indirect blocks, when
the allocated object is not accessible outside.
Requested and reviewed by: jeff
Tested by: pho
another, deleting it. If the directory is removed, UFS always need to
remove the .. ref, even if the ultimate ref on the parent would not
change. The new directory must have a new journal entry for that ref.
Otherwise journal processing would not properly account for the
parent's reference since it will belong to a removed directory entry.
Change ufs_rename()'s dotdot rename section to always
setup_dotdot_link(). In the tip != NULL case SUJ needs the newref dependency
allocated via setup_dotdot_link().
Stop setting isrmdir to 2 for newdirrem() in softdep_setup_remove().
Remove the isdirrem > 1 checks from newdirrem().
Reported by: many
Submitted by: jeff
Tested by: pho
to the disk, recurse to handle indirect blocks of next level that are
hidden by the corresponding entry.
In collaboration with: pho
Reviewed by: jeff, mckusick
Tested by: mckusick, pho
deallocate_dependencies() is done. This opens a race between softdep
thread and the thread that does the truncation:
A write of the indirect block causes the freeblks to become
ALLCOMPLETE while softdep_setup_freeblocks() dropped softdep lock. And
then, softdep_disk_write_complete() would reassign the workitem to the
mount point worklist, causing premature processing of the workitem, or
journal write exhaust the fb_jfreeblkhd and handle_written_jfreeblk does
the same reassign.
indir_trunc() then would find the indirect block that is locked (with lock
owned by kernel) but without any dependencies, causing it to hang in
getblk() waiting for buffer lock.
Do not mark freeblks as DEPCOMPLETE until deallocate_dependencies()
finished.
Analyzed, suggested and reviewed by: jeff
Tested by: pho
LK_CANRECURSE after a lock is created. Use them to implement macros that
otherwise manipulated the flags directly. Assert that the associated
lockmgr lock is exclusively locked by the current thread when manipulating
these flags to ensure the flag updates are safe. This last change required
some minor shuffling in a few filesystems to exclusively lock a brand new
vnode slightly earlier.
Reviewed by: kib
MFC after: 3 days
the worklist (in softdep_process_journal), but also after flushing the
workitems. Might be, we should even do this before bwillwrite() too, but
this seems to be not needed for now.
Fs might be suspended during processing the queue, and then there is
nobody around to unsuspend.
In collaboration with: pho
Tested by: bz
Reviewed by: jeff
the context of the process that reduced the effective count. Previously
all truncation as a result of unlink happened in the softdep flush
thread. This had the effect of being impossible to rate limit properly
with the journal code. Now the process issuing unlinks is suspended
when the journal files. This has a side-effect of improving rm
performance by allowing more concurrent work.
- Handle two cases in inactive, one for effnlink == 0 and another when
nlink finally reaches 0.
- Eliminate the SPACECOUNTED related code since the truncation is no
longer delayed.
Discussed with: mckusick
Apparently it's bad when we first have an ANSI prototype in function
declaration, but then use K&R in its defintion.
Complaint from: clang
MFC after: 2 weeks
on the last iteration. This can lead to a deadlock when we have
worklist items that cannot be immediately satisfied.
Reported by: uqs, Dimitry Andric <dimitry@andric.com>
- Remove some unnecessary debugging code and place some other under
SUJ_DEBUG.
- Examine the journal state in softdep_slowdown().
- Re-format some comments so I may more easily add flag descriptions.
snapshot code.
- Don't fsync() vnodes in prealloc if copy on write is in progress. It
is not safe to recurse back into the write path here.
Reported by: Vladimir Grebenschikov <vova@fbsd.ru>
successfully made it to the free list yet or not. This fixes
a deadlock that can occur with unlinked but referenced files.
Journal space and inodedeps were not correctly reclaimed because
the inode block was not left dirty.
Tested/Reported by: lwindschuh@googlemail.com
a revert call. In this case don't attempt to remove something that
has not yet been added. Otherwise this jaddref must hang around
to prevent the bitmap write as normal.
brings in support for an optional intent log which eliminates the need
for background fsck on unclean shutdown.
Sponsored by: iXsystems, Yahoo!, and Juniper.
With help from: McKusick and Peter Holm
truncate(2) call, or by being removed or truncated on open, either
new softupdate freeblks structure is allocated to track the freed
blocks of the node, or truncation is done syncronously when too many SU
dependencies are accumulated. The decision does not take into account
the allocated freeblks dependencies, allowing workloads that do huge
amount of truncations to exhaust the kernel memory.
Take the number of allocated freeblks into consideration for
softdep_slowdown().
Reported by: pluknet gmail com
Diagnosed and tested by: pho
Approved by: re (rwatson)
MFC after: 1 month
around the sequence that drop vnode lock and then busies the mount point.
Not having vlocked node or direct reference to the mp allows for the
forced unmount to proceed, making mp unmounted or reused.
Tested by: pho
Reviewed by: jeff
Approved by: re (kensmith)
MFC after: 2 weeks
Use inlined (due to FFSV_FORCEINSMQ) version of vn_vget_ino() to prevent
mountpoint from being unmounted and freed while no vnodes are locked.
Tested by: pho
Approved by: re (kensmith)
MFC after: 1 month
The later may need blocks from the underlying device that belongs
to normal files, that should not be locked while snap lock is held.
Reported and tested by: pho
MFC after: 1 month
- Implement real draining for vfs consumers by not relying on the
mnt_lock and using instead a refcount in order to keep track of lock
requesters.
- Due to the change above, remove the mnt_lock lockmgr because it is now
useless.
- Due to the change above, vfs_busy() is no more linked to a lockmgr.
Change so its KPI by removing the interlock argument and defining 2 new
flags for it: MBF_NOWAIT which basically replaces the LK_NOWAIT of the
old version (which was unlinked from the lockmgr alredy) and
MBF_MNTLSTLOCK which provides the ability to drop the mountlist_mtx
once the mnt interlock is held (ability still desired by most consumers).
- The stub used into vfs_mount_destroy(), that allows to override the
mnt_ref if running for more than 3 seconds, make it totally useless.
Remove it as it was thought to work into older versions.
If a problem of "refcount held never going away" should appear, we will
need to fix properly instead than trust on such hackish solution.
- Fix a bug where returning (with an error) from dounmount() was still
leaving the MNTK_MWAIT flag on even if it the waiters were actually
woken up. Just a place in vfs_mount_destroy() is left because it is
going to recycle the structure in any case, so it doesn't matter.
- Remove the markercnt refcount as it is useless.
This patch modifies VFS ABI and breaks KPI for vfs_busy() so manpages and
__FreeBSD_version will be modified accordingly.
Discussed with: kib
Tested by: pho
Show the b_dep value for the buffer in the show buffer command.
Add a comand to dump the dirty/clean buffer list for vnode.
Reviewed by: tegge
Tested and used by: pho
MFC after: 1 month
inode having number ino. In r170991, the ip was marked IN_MODIFIED, that
is not quite correct.
Mark only the right inode modified by checking inode number.
Reviewed by: tegge
In collaboration with: pho
MFC after: 1 month
dependencies. In particular, it may need this while syncing filesystem
being unmounted. Since during unmount MNTK_NOINSMNTQUE flag is set,
that could sometimes disallow insertion of the vnode into the vnode
mount list, softdep code needs to overwrite the MNTK_NOINSMNTQUE flag.
Create the ffs_vgetf() function that sets the VV_FORCEINSMQ flag for
new vnode and use it consistently from the softdep code instead of
ffs_vget().
Add the retry logic to the softdep_flushfiles() to flush the vnodes
that could be instantiated while flushing softdep dependencies.
Tested by: pho, kris
Reviewed by: tegge
MFC after: 1 month
state transitioning flags and of msleep(9) callings.
Use, instead, an algorithm very similar to what sx(9) and rwlock(9)
alredy do and direct accesses to the sleepqueue(9) primitive.
In order to avoid writer starvation a mechanism very similar to what
rwlock(9) uses now is implemented, with the correspective per-thread
shared lockmgrs counter.
This patch also adds 2 new functions to lockmgr KPI: lockmgr_rw() and
lockmgr_args_rw(). These two are like the 2 "normal" versions, but they
both accept a rwlock as interlock. In order to realize this, the general
lockmgr manager function "__lockmgr_args()" has been implemented through
the generic lock layer. It supports all the blocking primitives, but
currently only these 2 mappers live.
The patch drops the support for WITNESS atm, but it will be probabilly
added soon. Also, there is a little race in the draining code which is
also present in the current CVS stock implementation: if some sharers,
once they wakeup, are in the runqueue they can contend the lock with
the exclusive drainer. This is hard to be fixed but the now committed
code mitigate this issue a lot better than the (past) CVS version.
In addition assertive KA_HELD and KA_UNHELD have been made mute
assertions because they are dangerous and they will be nomore supported
soon.
In order to avoid namespace pollution, stack.h is splitted into two
parts: one which includes only the "struct stack" definition (_stack.h)
and one defining the KPI. In this way, newly added _lockmgr.h can
just include _stack.h.
Kernel ABI results heavilly changed by this commit (the now committed
version of "struct lock" is a lot smaller than the previous one) and
KPI results broken by lockmgr_rw() / lockmgr_args_rw() introduction,
so manpages and __FreeBSD_version will be updated accordingly.
Tested by: kris, pho, jeff, danger
Reviewed by: jeff
Sponsored by: Google, Summer of Code program 2007
vnodes belonging to the mountpoint. Also, yield when in the
softdep_process_worklist() even when we are not going to sleep due to
buffer drain.
It is believed that the ULE fixed the problem [1], but the yielding
seems to be needed at least for the 4BSD case.
Discussed: on stable@, with bde
Reviewed by: tegge, jeff [1]
MFC after: 2 weeks
BO_LOCK/UNLOCK/MTX when manipulating the bufobj.
- Create a new lock in the bufobj to lock bufobj fields independently.
This leaves the vnode interlock as an 'identity' lock while the bufobj
is an io lock. The bufobj lock is ordered before the vnode interlock
and also before the mnt ilock.
- Exploit this new lock order to simplify softdep_check_suspend().
- A few sync related functions are marked with a new XXX to note that
we may not properly interlock against a non-zero bv_cnt when
attempting to sync all vnodes on a mountlist. I do not believe this
race is important. If I'm wrong this will make these locations easier
to find.
Reviewed by: kib (earlier diff)
Tested by: kris, pho (earlier diff)
after each SYSINIT() macro invocation. This makes a number of
lightweight C parsers much happier with the FreeBSD kernel
source, including cflow's prcc and lxr.
MFC after: 1 month
Discussed with: imp, rink
callout_* API (e.g. callout_init_mtx(9)). This was one of the numerous
items on the http://wiki.freebsd.org/SMPTODO list.
Reviewed by: imp, obrien, jhb
MFC after: 1 week
