unable to automatically find alternate superblocks. This checkin
places the information needed to find alternate superblocks to the
end of the area reserved for the boot block.
Filesystems created with a newfs of this vintage or later will
create the recovery information. If you have a filesystem created
prior to this change and wish to have a recovery block created for
your filesystem, you can do so by running fsck in forground mode
(i.e., do not use the -p or -y options). As it starts, fsck will
ask ``SAVE DATA TO FIND ALTERNATE SUPERBLOCKS'' to which you should
answer yes.
Discussed with: kib, imp
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D11589
Update the use of the B_CACHE flag (since the May 1999 commit
that made it the correct test here).
Reported by: Andreas Longwitz <longwitz@incore.de>
Reviewed by: kib
Tested by: Peter Holm
MFC after: 1 week
For freshly allocated snapdata, Lock sn_lock in advance, so
si_snapdata readers see the locked snapdata and not race.
For existing snapdata, if the thread was put to sleep waiting for
sn_lock, re-read si_snapdata. This either closes the race or makes
the reliance on LK_DRAIN less important.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
It is possible for ffs_snapblkfree() to race and lock snaplock while
the devvp snapdata is instantiated, but no snapshots exist. In this
case the loop over snapshots in ffs_snapblkfree() is not executed, and
the local variable vp is left initialized to NULL.
Unlock using &sn->sn_lock and not vp->v_vnlock. For the inodes on the
snapshot list, the locks are same.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
in ffs_snapremove().
Apparently ffs_snapremove() may be called with the snap lock recursed,
at least one trace demonstrated this when snapshot vnode was unlinked
while synced. It was inactivated from the syncer thread.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Update filesystems not currently using vop_stdpathconf() in pathconf
VOPs to use vop_stdpathconf() for any configuration variables that do
not have filesystem-specific values. vop_stdpathconf() is used for
variables that have system-wide settings as well as providing default
values for some values based on system limits. Filesystems can still
explicitly override individual settings.
PR: 219851
Reported by: cem
Reviewed by: cem, kib, ngie
MFC after: 1 month
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D11541
group. Change all code points that open-coded this functionality
to use the new function. This commit is a refactoring with no
change in functionality.
In the future this change allows more robust checking of cylinder
group reads along the lines discussed in the hardening UFS session
at BSDCan (retry I/O, add checksums, etc). For more detail see the
session notes at https://wiki.freebsd.org/DevSummit/201706/HardeningUFS
Reviewed by: kib
host.
Problems start appearing when there are several threads all doing
operations on a UFS volume and the SU workqueue needs a cleanup. It is
possible that each thread calling softdep_request_cleanup() owns the
lock for some dirty vnode (e.g. all of them are executing mkdir(2),
mknod(2), creat(2) etc) and all vnodes which must be flushed are locked
by corresponding thread. Then, we get all the threads simultaneously
entering softdep_request_cleanup().
There are two problems:
- Several threads execute MNT_VNODE_FOREACH_ALL() loops in parallel. Due
to the locking, they quickly start executing 'in phase' with the speed
of the slowest thread.
- Since each thread already owns the lock for a dirty vnode, other threads
non-blocking attempt to lock the vnode owned by other thread fail,
and loops executing without making the progress.
Retry logic does not allow the situation to recover. The result is
a livelock.
Fix these problems by making the following changes:
- Allow only one thread to enter MNT_VNODE_FOREACH_ALL() loop per mp.
A new flag FLUSH_RC_ACTIVE guards the loop.
- If there were failed locking attempts during the loop, abort retry
even if there are still work items on the mp work list. An
assumption is that the items will be cleaned when other thread
either fsyncs its vnode, or unlock and allow yet another thread to
make the progress.
It is possible now that some calls would get undeserved ENOSPC from
ffs_alloc(), because the cleanup is not aggressive enough. But I do
not see how can we reliably clean up workitems if calling
softdep_request_cleanup() while still owning the vnode lock. I thought
about scheme where ffs_alloc() returns ERESTART and saves the retry
counter somewhere in struct thread, to return to the top level, unlock
the vnode and retry. But IMO the very rare (and unproven) spurious
ENOSPC is not worth the complications.
Reported and tested by: pho
Style and comments by: mckusick
Reviewed by: mckusick
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
the last step of ffs_unmount().
It is possible that the mount point is recorded for cleanup in AST
context while softdep flush is executed during unmount. The workitems
are flushed by other means for the unmount, but the stray reference to
struct mount blocks destruction of mount. Check for the situation and
manually call vfs_rel() before returning from ffs_unmount().
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
makefs(1) has a number of signedness warnings (when built with higher
WARNS), most of which can be addressed by careful application of casts
in makefs itself.
There is one case where a signedness warning arises from the blksize
macro, so must be addressed in the macro itself.
Reviewed by: kib, mckusick
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D10589
Rather than the global NAME_MAX constant. This change is required to
support systems with a NAME_MAX/MAXNAMLEN that differs from UFS_MAXNAMLEN.
This was missed in r313475 due to the alternative spelling ("NAME_MAX") of
MAXNAMLEN. This change is also similar in spirit to r313780.
Reported by: ngie@
Sponsored by: Dell EMC Isilon
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.
Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96
Thread might create a condition for delayed SU cleanup, which creates
a reference to the mount point in td_su, but exit without returning
through userret(), e.g. when terminating due to single-threading or
process exit. In this case, td_su reference is not dropped and mount
point cannot be freed.
Handle the situation by clearing td_su also in the thread destructor
and in exit1(). softdep_ast_cleanup() has to receive the thread as
argument, since e.g. thread destructor is executed in different
context.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
As suggested in r167010, use the structure type and macros to access and
modify UFS2 extended attributes. Add assertions that pointers are
aligned in places where we now access the data through a structure
pointer, instead of character-by-character.
PR: 216127
Reported by: dewayne at heuristicsystems.com.au
Reviewed by: kib@
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D9225
The ea_name string is not nul-terminated. Correct the documentation.
Because the subsequent field is padded to 8 bytes, and the padding is
zeroed, the ea_name string will appear to be nul-terminated whenever the
length isn't exactly one (mod eight).
This was introduced in r167010 (2007).
Additionally, mark the length fields as unsigned. This particularly
matters for the single byte ea_namelength field, which can represent
extended attribute names up to 255 bytes long.
No functional change.
PR: 216127
Reported by: dewayne at heuristicsystems.com.au
Reviewed by: kib@
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D9206
The swap pager enqueues laundered pages near the head of the inactive queue
to avoid another trip through LRU before reclamation. This change adds
support for this behaviour to the vnode pager and makes use of it in UFS and
ext2fs. Some ioflag handling is consolidated into a common subroutine so
that this support can be easily extended to other filesystems which make use
of the buffer cache. No changes are needed for ZFS since its putpages
routine always undirties the pages before returning, and the laundry
thread requeues the pages appropriately in this case.
Reviewed by: alc, kib
Differential Revision: https://reviews.freebsd.org/D8589
Currently mount update keeps vfs_busy(9) reference on the mount point
during MNT_UPDATE VFS_MOUNT() vfsops call. This already provides the
exclusion, but is problematic for filesystems which need to perform
namei(9) during VFS_MOUNT(MNT_UPDATE) operations, e.g. to refresh
mnt_from path, because namei(9) must not be called while the
vfs_busy(9) reference is owned.
Check for MNT_UPDATE flag before setting MNTK_UNMOUNT, and for
MNTK_UNMOUNT before entering innards of vfs_domount_update(), failing
syscalls with EBUSY if conflict is detected. Keep vfs_busy(9)
reference around VFS_MOUNT(MNT_UPDATE) calls still to not change VFS
KPI.
In the update path in ffs_mount(), drop vfs_busy() reference around
namei(), which is now safe due to unmount never executing in parallel
with VFS_MOUNT(MNT_UPDATE), and which avoids the deadlock.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
data structure sizes when mounting and reloading UFS/FFS
filesystems by using a u_long rather than an int for the size.
Reported by: Mariusz Zaborski <oshogbo@>
MFC after: 1 week
which also use buffer cache.
Most important addition to the code is the handling of filesystems
where the block size is less than the machine page size, which might
require reading several buffers to validate single page.
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
directory create and delete operations. If it ever finds a directory
with a link count less than 2, it panics. Thus, an rm -rf that
encounters a directory with a link count below 2 causes a kernel
panic. The proposed fix is to return the error EINVAL rather than
panicing. The effect is that the requested operation is not done,
but the system continues to run. At a more convenient later time,
the filesystem can be unmounted and cleaned (with fsck or journal
run). Once cleaned, the operation can be rerun to successful
completion.
This fix takes that approach. The panic message has been converted
into a uprintf(9) to provide the user with the inode number and
filesystem mount point of the offending directory and EINVAL is
returned for the operation.
The long (three year) delay in fixing this problem occurred because
the bug was misclassified when originally assigned and only this week
was found during a sweep of old unresolved bug reports.
PR: 180894
Reviewed by: kib
MFC after: 2 weeks
See the comments for more detailed description of the algorithm.
The pager is used unconditionally when the block size of the
underlying device is larger than the machine page size, since local
vnode pager cannot handle the configuration [1]. Otherwise, the
vfs.ffs.use_buf_pager sysctl allows to switch to the local pager.
Measurements demonstrated no regression in the ever-important
buildworld benchmark, and small (~5%) throughput improvements in the
special microbenchmark configuration for dbench over swap-backed
md(4).
Code can be generalized and reused for other filesystems which use
buffer cache.
Reported by: Anton Yuzhaninov <citrin@citrin.ru> [1]
Tested by: pho
Benchmarked by: mjg, pho
Reviewed by: alc, markj, mckusick (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D8198
Reclaimed vnode type is VBAD, so succesful comparision like
devvp->v_type != VREG does not imply that the devvp references
snapshot, it might be due to a reclaimed vnode. Explicitely check the
vnode type.
In the the most important case of ffs_blkfree(), the devfs vnode is
locked and its type is stable. In other cases, if the vnode is
reclaimed right after the check, hopefully the buffer methods return
right error codes.
Reviewed by: mckusick
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
- Use _Bool to not require userspace to include stdbool.h.
- Make extattr.h usable without vnode_if.h.
- Follow i_ump to get cdev pointer.
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Remove redunand i_dev and i_fs pointers, which are available as
ip->i_ump->um_dev and ip->i_ump->um_fs, and reorder members by size to
reduce padding. To compensate added derefences, the most often i_ump
access to differentiate between UFS1 and UFS2 dinode layout is
removed, by addition of the new i_flag IN_UFS2. Overall, this
actually reduces the amount of memory dereferences.
On 64bit machine, original struct inode size is 176, reduced to 152
bytes with the change.
Tested by: pho (previous version)
Reviewed by: mckusick
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
mounts in almost all cases instead of in most cases. Don't override
DOINGASYNC() by any condition except IO_SYNC.
Fix previous sprinking of DOINGASYNC() checks. Don't override IO_SYNC
by DOINGASYNC(). In ffs_write() and ffs_extwrite(), there were
intentional overrides that just broke O_SYNC of data. In
ffs_truncate(), there are 5 calls to ffs_update(), 4 with
apparently-unintentional overrides and 1 without; this had no effect
due to the main async mount hack descibed below.
Fix 1 place in ffs_truncate() where the caller's IO_ASYNC was overridden
for the soft updates case too (to do a delayed write instead of a sync
write). This is supposed to be the only change that affects anything
except async mounts.
In ffs_update(), remove the 19 year old efficiency hack of ignoring
the waitfor flag for async mounts, so that fsync() almost works for
async mounts. All callers are supposed to be fixed to not ask for a
sync update unless they are for fsync() or [I]O_SYNC operations.
fsync() now almost works for async mounts. It used to sync the data
but not the most important metdata (the inode). It still doesn't sync
associated directories.
This gave 10-20% fewer writes for my makeworld benchmark with async
mounted tmp and obj directories from an already small number.
Style fixes:
- in ffs_balloc.c, remove rotted quadruplicated comments about the
simplest part of the DOING*() decisions and rearrange the nearly-
quadruplicated code to be more nearly so.
- in ufs_vnops.c, use a consistent style with less negative logic and
no manual "optimization" of || to | in DOING*() expressions.
Reviewed by: kib (previous version)
truncation failed.
Doing so resulted in inconsistent state of the ufs dirhash with regard
to the actual directory inode state, and could lead to spurious ENOENT
errors for lookups of existing files in production kernels, or
assertion failures in the debugging kernels.
Change the logic of calling ufsdirhash_dirtrunc() to be same as in
ufs_direnter(). Execute UFS_TRUNCATE() first, log error, and only do
dirtrunc() if UFS_TRUNCATE() succeeded.
Note that the problem was exacerbated by the bug in the
flush_newblk_dep() function (see r305599), which caused in the spurios
errors from ffs_sync() and then ffs_truncate().
In collaboration with: pho
Reviewed by: mckusick
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
The buffer lock is retried on failed LK_SLEEPFAIL attempt, and error
from the failed attempt is irrelevant. But since there is path after
retry which does not clear error, it is possible to return spurious
error from the function.
The issue resulted in a spurious failure of softdep_sync_buf(),
causing further spurious failure of ffs_sync().
In collaboration with: pho
Reviewed by: mckusick
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
This change is formally not needed, since i_endoff not used in all
code paths after the call to ufs_direnter(), and i_endoff is
recalculated by the next lookup. But having the value correct makes
the reasoning about code simpler.
Reported and tested by: pho
Reviewed by: mckusick
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
cleared since nothing prevents completion of the parallel quotaoff.
There is nothing to sync in this case, and no reason to panic.
Reported and tested by: pho
Reviewed by: mckusick
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
operations. Instead of upgrading, assert that the lock is exclusive.
Explain the cause in comments.
This effectively reverts r209367.
Tested by: pho
Reviewed by: mckusick
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
going to re-read inodes.
Secondary write initiators, e.g. ufs_inactive(), might need to start a
write while owning the vnode lock. Since the suspended state
established by /dev/ufssuspend prevents them from entering
vn_start_secondary_write(), we get deadlock otherwise.
Note that it is arguably not very useful to re-read inodes after
/dev/ufssuspend suspension, because the suspension does not block
readers, and other threads might read existing files in parallel with
suspension owner (for now, only growfs(8)) operations. This
effectively means that suspension owner cannot safely modify existing
inodes, and then there is no sense in re-reading. But keep the code
enabled for now.
Reported and tested by: pho
Reviewed by: mckusick
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
with softupdates panics the kernel. The problem that has been pointed
out is that when there is a transient write error on certain metadata
blocks, specifically directory blocks (PAGEDEP), inode blocks
(INODEDEP), indirect pointer blocks (INDIRDEPS), and cylinder group
(BMSAFEMAP, but only when journaling is enabled), we get a panic
in one of the routines called by softdep_disk_io_initiation that
the I/O is "already started" when we retry the write.
These dependency types potentially need to do roll-backs when called
by softdep_disk_io_initiation before doing a write and then a
roll-forward when called by softdep_disk_write_complete after the
I/O completes. The panic happens when there is a transient error.
At the top of softdep_disk_write_complete we check to see if the
write had an error and if an error occurred we just return. This
return is correct most of the time because the main role of the routines
called by softdep_disk_write_complete is to process the now-completed
dependencies so that the next I/O steps can happen.
But for the four types listed above, they do not get to do their
rollback operations. This causes the panic when softdep_disk_io_initiation
gets called on the second attempt to do the write and the roll-back
routines find that the roll-backs have already been done. As an
aside I note that there is also the problem that the buffer will
have been unlocked and thus made visible to the filesystem and to
user applications with the roll-backs in place.
The way to resolve the problem is to add a flag to the routines called
by softdep_disk_write_complete for the four dependency types noted
that indicates whether the write was successful (WRITESUCCEEDED).
If the write does not succeed, they do just the roll-backs and then
return. If the write was successful they also do their usual
processing of the now-completed dependencies.
The fix was tested by selectively injecting write errors for buffers
holding dependencies of each of the four types noted above and then
verifying that the kernel no longer paniced and that following the
successful retry of the write that the filesystem could be unmounted
and successfully checked cleanly.
PR: 211013
Reviewed by: kib
allocation unwinding.
Dandling buffers are released on UFS_BALLOC() failure to ensure that
later attempt to allocate blocks in close range do not find the blocks
with invalid content, since possible partial block allocations are
unwound. As such, it is not enough to just release the buffers, the
pages must also invalidated and removed from the vnode vm_object
queue. Otherwise the pages might be found later and used to
reconstruct indirect buffers when doing allocations at offset close to
the failure point, and their stale content compromise the filesystem
integrity.
Note that just marking the buffer as B_INVAL is not enough, B_NOCACHE
is required. To be sure, clear the B_CACHE flag as well. This
complements the r174973, which started releasing buffers.
Reported and tested by: pho
Reviewed by: mckusick
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
that recorded allocated blocks numbers match the physical block
numbers of dandling buffers which are released.
When finally freeing the blocks during unwind, assert that dandling
buffers where not re-allocated. They shouldn't, because the vnode lock
is owned exclusive.
Reviewed by: mckusick
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
have SU enabled, there is no point in calling softdep_request_cleanup().
The call cannot produce free blocks, but we unecessarily lock ufsmount
and do inode block write. Usual point of not doing optimizations for
the corner case of the full volume is not applicable there, the work
is easily avoidable, and the addition CPU and disk io load do not lead
to succeeding retry.
Reviewed by: mckusick
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
overflow local arrays. This is not immediately obvious from the
static code inspection, due to retry logic.
Reviewed by: mckusick
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
before UFS_BALLOC() is called. I do not believe that this caused any
real issue on FreeBSD because the exclusive vnode lock is held over
the balloc/resize, the change is to make formally correct KPI use.
Based on: the Matthew Dillon' patch from DragonFly BSD
PR: 93942
Reviewed by: mckusick
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
volumes. Treat the field as a semaphore protecting availability of
the device for mounting. Do no access devvp->v_rdev without the vnode
lock owned.
Protect change of the devvp->v_bufobj bo_ops vector with the vnode
lock.
Reviewed by: bde
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
opened in O_SYNC mode, at least for UFS. This also handles
truncation, done due to the O_SYNC | O_TRUNC flags combination to
open(2), in synchronous way.
Noted by: bde
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
remounted to writeable after initial read-only. Assign to
dev->si_mountpt earlier to account the accesses done at the mount
time.
Based on submission by: bde
MFC after: 1 week
rounddown2 tends to produce longer lines than the original code
and when the code has a high indentation level it was not really
advantageous to do the replacement.
This tries to strike a balance between readability using the macros
and flexibility of having the expressions, so not everything is
converted.
for limiting disk (actually filesystem) IO.
Note that in some cases these limits are not quite precise. It's ok,
as long as it's within some reasonable bounds.
Testing - and review of the code, in particular the VFS and VM parts - is
very welcome.
MFC after: 1 month
Relnotes: yes
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D5080
into per-mount taskqueue with the private taskqueue processing thread.
This allows to drain the taskqueue on unmount, to ensure that all
TRIMs are finished before mount structures are freed.
But just draining the taskqueue where TRIM biodone geom-up completions
are processed is not enough, since ffs_blkfree(), called by the task,
might result in more writes. Count inflight delayed blkfree's and
pause() unmount until the counter drains as well.
Reported by: Nick Evans <nevans@talkpoint.com>
Tested by: Nick Evans <nevans@talkpoint.com>, pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
expects that the loop is always exited with the SU lock owned, even on
error.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 3 days
allocated. When shortening the length of a file in which the new end
of the file contains a hole, the hole must have a block allocated.
Reported by: Maxim Sobolev
Reviewed by: kib
Tested by: Peter Holm
crash a server that has exported UFS2 by presenting a filehandle
with an inode number that references an uninitialized inode in a
cylinder group. The problem is that UFS2 only initializes blocks
of inodes as they are first allocated and ffs_fhtovp() does not
validate that the inode is in a range of inodes that have been
initialized. Attempting to read an uninitialized inode gets random
data from the disk. When the kernel tries to interpret it as an
inode, panics often arise.
Reported by: Christos Zoulas (from NetBSD)
Reviewed by: kib
a buffer pointer in the event of an error (for some errors it would
return a buffer pointer and for other errors it would not return a
buffer pointer). The cluster_read() function was similarly inconsistent.
Clients of these functions were inconsistent in handling errors.
Some would assume that no buffer was returned after an error and
would thus lose buffers under certain error conditions. Others would
assume that brelse() should always be called after an error and
would thus panic the system under certain error conditions.
To correct both of these problems with minimal code churn, bread()
and cluster_write() now always free the buffer when returning an
error thus ensuring that buffers will never be lost. The brelse()
routine checks for being passed a NULL buffer pointer and silently
returns to avoid panics. Thus both approaches to handling error
returns from bread() and cluster_read() will work correctly.
Future code should be written assuming that bread() and cluster_read()
will never return a buffer with an error, so should not attempt to
brelse() the buffer when an error is returned.
Reviewed by: kib
ast was rescheduled during VFS_SYNC(). It is possible that enough
parallel writes or slow/hung volume result in VFS_SYNC() deferring to
the ast flushing of workqueue.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Cleanup setting of ctime/mtime/birthtime: do not set IN_ACCESS or
IN_UPDATE, then clear them with ufs_itimes(), making transient
(possibly inconsistent) change to the times, and then copy
user-supplied times into the inode. Instead, directly clear IN_ACCESS
or IN_UPDATE when user supplied the time, and copy the value into the
inode.
Minor inconsistency left is that the inode ctime is updated even when
birthtime update attempt is performed on a UFS1 volume.
Submitted by: bde
MFC after: 2 weeks
the name of a filesystem when setting it as the first parameter to the
getnewvnode() function. Most filesystems call getnewvnode from just one
place so can use a literal string as the first parameter. However, NFS
calls getnewvnode from two places, so we create a global constant string
that can be used by the two instances. This change also collapses two
instances of getnewvnode() in the UFS filesystem to a single call.
Reviewed by: kib
Tested by: Peter Holm
deletions. Ability to do deletions is a strong indication that this
optimization will not help performance. It will only generate extra write
traffic. These devices are typically flash based and have a limited number of
write cycles. In addition, making the file contiguous in LBA space doesn't
improve the access times from flash devices because they have no seek time.
Reviewed by: mckusick@
of the D_NEWBLK kinds of dependencies (i.e. D_ALLOCDIRECT and
D_ALLOCINDIR), which can exhaust kmem.
Handle excess of D_NEWBLK in the same way as excess of D_INODEDEP and
D_DIRREM, by scheduling ast to flush dependencies, after the thread,
which created new dep, left the VFS/FFS innards. For D_NEWBLK, the
only way to get rid of them is to do full sync, since items are
attached to data blocks of arbitrary vnodes. The check for D_NEWBLK
excess in softdep_ast_cleanup_proc() is unlocked.
For 32bit arches, reduce the total amount of allowed dependencies by
two. It could be considered increasing the limit for 64 bit platforms
with direct maps.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
'buf' is inconvenient and has lead me to some irritating to discover
bugs over the years. It also makes it more challenging to refactor
the buf allocation system.
- Move swbuf and declare it as an extern in vfs_bio.c. This is still
not perfect but better than it was before.
- Eliminate the unused ffs function that relied on knowledge of the buf
array.
- Move the shutdown code that iterates over the buf array into vfs_bio.c.
Reviewed by: kib
Sponsored by: EMC / Isilon Storage Division
- Use pointer assignment rather than a combination of pointers and
flags to switch buffers between unmapped and mapped. This eliminates
multiple flags and generally simplifies the logic.
- Eliminate b_saveaddr since it is only used with pager bufs which have
their b_data re-initialized on each allocation.
- Gather up some convenience routines in the buffer cache for
manipulating buf space and buf malloc space.
- Add an inline, buf_mapped(), to standardize checks around unmapped
buffers.
In collaboration with: mlaier
Reviewed by: kib
Tested by: pho (many small revisions ago)
Sponsored by: EMC / Isilon Storage Division
This obviates the need for a MNTK_SUSPENDABLE flag, since passthrough
filesystems like nullfs and unionfs no longer need to inherit this
information from their lower layer(s). This change also restores the
pre-r273336 behaviour of using the presence of a susp_clean VFS method to
request suspension support.
Reviewed by: kib, mjg
Differential Revision: https://reviews.freebsd.org/D2937
* GENERAL
- Update copyright.
- Make kernel options for RANDOM_YARROW and RANDOM_DUMMY. Set
neither to ON, which means we want Fortuna
- If there is no 'device random' in the kernel, there will be NO
random(4) device in the kernel, and the KERN_ARND sysctl will
return nothing. With RANDOM_DUMMY there will be a random(4) that
always blocks.
- Repair kern.arandom (KERN_ARND sysctl). The old version went
through arc4random(9) and was a bit weird.
- Adjust arc4random stirring a bit - the existing code looks a little
suspect.
- Fix the nasty pre- and post-read overloading by providing explictit
functions to do these tasks.
- Redo read_random(9) so as to duplicate random(4)'s read internals.
This makes it a first-class citizen rather than a hack.
- Move stuff out of locked regions when it does not need to be
there.
- Trim RANDOM_DEBUG printfs. Some are excess to requirement, some
behind boot verbose.
- Use SYSINIT to sequence the startup.
- Fix init/deinit sysctl stuff.
- Make relevant sysctls also tunables.
- Add different harvesting "styles" to allow for different requirements
(direct, queue, fast).
- Add harvesting of FFS atime events. This needs to be checked for
weighing down the FS code.
- Add harvesting of slab allocator events. This needs to be checked for
weighing down the allocator code.
- Fix the random(9) manpage.
- Loadable modules are not present for now. These will be re-engineered
when the dust settles.
- Use macros for locks.
- Fix comments.
* src/share/man/...
- Update the man pages.
* src/etc/...
- The startup/shutdown work is done in D2924.
* src/UPDATING
- Add UPDATING announcement.
* src/sys/dev/random/build.sh
- Add copyright.
- Add libz for unit tests.
* src/sys/dev/random/dummy.c
- Remove; no longer needed. Functionality incorporated into randomdev.*.
* live_entropy_sources.c live_entropy_sources.h
- Remove; content moved.
- move content to randomdev.[ch] and optimise.
* src/sys/dev/random/random_adaptors.c src/sys/dev/random/random_adaptors.h
- Remove; plugability is no longer used. Compile-time algorithm
selection is the way to go.
* src/sys/dev/random/random_harvestq.c src/sys/dev/random/random_harvestq.h
- Add early (re)boot-time randomness caching.
* src/sys/dev/random/randomdev_soft.c src/sys/dev/random/randomdev_soft.h
- Remove; no longer needed.
* src/sys/dev/random/uint128.h
- Provide a fake uint128_t; if a real one ever arrived, we can use
that instead. All that is needed here is N=0, N++, N==0, and some
localised trickery is used to manufacture a 128-bit 0ULLL.
* src/sys/dev/random/unit_test.c src/sys/dev/random/unit_test.h
- Improve unit tests; previously the testing human needed clairvoyance;
now the test will do a basic check of compressibility. Clairvoyant
talent is still a good idea.
- This is still a long way off a proper unit test.
* src/sys/dev/random/fortuna.c src/sys/dev/random/fortuna.h
- Improve messy union to just uint128_t.
- Remove unneeded 'static struct fortuna_start_cache'.
- Tighten up up arithmetic.
- Provide a method to allow eternal junk to be introduced; harden
it against blatant by compress/hashing.
- Assert that locks are held correctly.
- Fix the nasty pre- and post-read overloading by providing explictit
functions to do these tasks.
- Turn into self-sufficient module (no longer requires randomdev_soft.[ch])
* src/sys/dev/random/yarrow.c src/sys/dev/random/yarrow.h
- Improve messy union to just uint128_t.
- Remove unneeded 'staic struct start_cache'.
- Tighten up up arithmetic.
- Provide a method to allow eternal junk to be introduced; harden
it against blatant by compress/hashing.
- Assert that locks are held correctly.
- Fix the nasty pre- and post-read overloading by providing explictit
functions to do these tasks.
- Turn into self-sufficient module (no longer requires randomdev_soft.[ch])
- Fix some magic numbers elsewhere used as FAST and SLOW.
Differential Revision: https://reviews.freebsd.org/D2025
Reviewed by: vsevolod,delphij,rwatson,trasz,jmg
Approved by: so (delphij)
First, on the write error, bufdone() call from ffs_backgroundwrite()
panics because pbrelvp() cleared bp->b_bufobj, while brelse() would
try to re-dirty the copy of the cg buffer. Handle this by setting
B_INVAL for the case of BIO_ERROR.
Second, we must re-dirty the real buffer containing the cylinder group
block data when background write failed. Real cg buffer was already
marked clean in ffs_bufwrite(). After the BV_BKGRDINPROG flag is
cleared on the real cg buffer in ffs_backgroundwrite(), buffer scan
may reuse the buffer at any moment. The result is lost write, and if
the write error was only transient, we get corrupted bitmaps.
We cannot re-dirty the original cg buffer in the
ffs_backgroundwritedone(), since the context is not sleepable,
preventing us from sleeping for origbp' lock. Add BV_BKGDERR flag
(protected by the buffer object lock), which is converted into delayed
write by brelse(), bqrelse() and buffer scan.
In collaboration with: Conrad Meyer <cse.cem@gmail.com>
Reviewed by: mckusick
Sponsored by: The FreeBSD Foundation (kib),
EMC/Isilon storage division (Conrad)
MFC after: 2 weeks
the active vnode list for the given mount point, with the assumption
that vnodes with dirty pages are active. This is enforced by
vinactive() doing vm_object_page_clean() pass over the vnode pages.
The issue is, if vinactive() cannot be called during vput() due to the
vnode being only shared-locked, we might end up with the dirty pages
for the vnode on the free list. Such vnode is invisible to syncer,
and pages are only cleaned on the vnode reactivation. In other words,
the race results in the broken guarantee that user data, written
through the mmap(2), is written to the disk not later than in 30
seconds after the write.
Fix this by keeping the vnode which is freed but still owing
inactivation, on the active list. When syncer loops find such vnode,
it is deactivated and cleaned by the final vput() call.
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
softdep_sync() similarly to the regular vnode sync. Allow retry for
both vnode types.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
When deallocate_dependencies() is performed,
softdep_journal_freeblocks() already called cancel_allocdirect() which
should have eliminated direct dependencies for all truncated full
blocks. The indirect dependencies are allowed above, since second-
and third-level dependencies are only dealt with by the code which
frees indirect block, which happens after the inode write.
Discussed with: mckusick, jeff
Reviewed by: jeff
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
buildkernel run.
Some of them were write-only under some kernel options, e.g. variables
keeping values only used by CTR() macros. It costs nothing to the
code readability and correctness to eliminate the warnings in those
cases too by removing the local cached values used only for
single-access.
Review: https://reviews.freebsd.org/D2665
Reviewed by: rodrigc
Looked at by: bjk
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Eliminate it, and simplify code by removing the local dflags variable
always initialized to DEPALLOC.
Noted by: mckusick
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
limits in the code which is deep in the call stack, and owns several
critical system resources, like vnode locks. Attempt to wait while
the per-mount softupdate thread cleans up the backlog may deadlock,
because the thread might need to lock the same vnode which is owned by
the waiting thread.
Instead of synchronously waiting for the worker, perform the worker'
tickle and pause until the backlog is cleaned, at the safe point
during return from kernel to usermode. A new ast request to call
softdep_ast_cleanup() is created, the SU code now only checks the size
of queue and schedules ast.
There is no ast delivery for the kernel threads, so they are exempted
from the mechanism, except NFS daemon threads. NFS server loop
explicitely checks for the request, and informs the schedule_cleanup()
that it is capable of handling the requests by the process P2_AST_SU
flag. This is needed because nfsd may be the sole cause of the SU
workqueue overflow. But, to not cause nsfd to spawn additional
threads just because we slow down existing workers, only tickle su
threads, without waiting for the backlog cleanup.
Reviewed by: jhb, mckusick
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
