bees might be unpaused at any time, so make sure that the dynamic load
calculation is ready with a non-zero thread count.
This avoids a delay of up to 5 seconds when responding to SIGUSR2
when loadavg tracking is enabled.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
When paused, TaskConsumer threads will eventually notice the paused
condition and exit; however, there's nothing to restart threads when
exiting the paused state.
When unpausing, and while the lock is already held, create TaskConsumer
threads as needed to reach the target thread count.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
Commit 72c3bf8438830b65cae7bdaff126053e562280e5 ("fs: handle ENOENT
within lib") was meant to prevent exceptions when a subvol is deleted.
If the search ioctl fails, the kernel won't set nr_items in the
ioctl output, which means `nr_items` still has the input value. When
ENOENT is detected, `this->nr_items` is set to 0, then later `*this =
ioctl_ptr->key` overwrites `this->nr_items` with the original requested
number of items.
This replaced the ENOENT exception with an exception triggered by
interpreting garbage in the memory buffer. The number of exceptions
was reduced because the memory buffers are frequently reused, but upper
layers would then reject the data or ignore it because it didn't match
the key range.
Fix by setting `ioctl_ptr->key.nr_items`, which then overwrites
`this->nr_items`, so the loop that extracts items from the ioctl data
gets the right number of items (i.e. zero).
Fixes: 72c3bf8438830b65cae7bdaff126053e562280e5 ("fs: handle ENOENT within lib")
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
operator<< was a friend class that locked the ByteVector, then invoked
hexdump on the bytevector, which used ByteVector::operator[]...which
locked the ByteVector, resulting in a deadlock.
operator<< shouldn't be a friend class anyway. Make hexdump use the
normal public access methods for ByteVector.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
Add a second level queue which is only serviced when the local and global
queues are empty.
At some point there might be a need to implement a full priority queue,
but for now two classes are sufficient.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
This should help clean up some of the uglier status outputs.
Supports:
* multi-line table cells
* character fills
* sparse tables
* insert, delete by row and column
* vertical separators
and not much else.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
Add a master switch to turn off the entire MultiLock infrastructure for
testing, without having to remove and add all the individual entry points.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
This prevents the storms of exceptions that occur when a subvol is
deleted. We simply treat the entire tree as if it was empty.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
The kernel has not required a 16 MiB limit on dedupe requests since
v4.18-rc1 b67287682688 ("Btrfs: dedupe_file_range ioctl: remove 16MiB
restriction").
Kernels before v4.18 would truncate the request and return the size
actually deduped in `bytes_deduped`. Kernel v4.18 and later will loop
in the kernel until the entire request is satisfied (although still
in 16 MiB chunks, so larger extents will be split).
Modify the loop in userspace to measure the size the kernel actually
deduped, instead of assuming the kernel will only accept 16 MiB.
On current kernels this will always loop exactly once.
Since we now rely on `bytes_deduped`, make sure it has a sane value.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
Apparently reinterpret_cast<uint64_t> sign-extends 32-bit pointers.
This is OK when running on a 32-bit kernel that will truncate the pointer
to 32 bits, but when running on a 64-bit kernel, the extra bits are
interpreted as part of the (now very invalid) address.
Use <uintptr_t> instead, which is unsigned, integer, and the same word
size as the arch's pointer type. Ordinary numeric conversion can take
it from there, filling the rest of the word with zeros.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
Some malloc implementations will try to mmap() and munmap() large buffers
every time they are used, causing a severe loss of performance.
Nothing ever overrode the virtual methods, and there was no virtual
destructor, so they cause compiler warnings at build time when used with
a template that tries to delete pointers to them.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
crucible::VERSION doesn't make much sense now that libcrucible no
longer exists as a shared library. Nothing ever referenced it, so
it can go away.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
According to ioctl_iflags(2):
The type of the argument given to the FS_IOC_GETFLAGS and
FS_IOC_SETFLAGS operations is int *, notwithstanding the
implication in the kernel source file include/uapi/linux/fs.h
that the argument is long *.
So this code doesn't work on be64 machines.
Also, Valgrind complains about it.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
A subtle distinction, and not one that is particularly relevant to bees,
but it does make toolchains complain.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
Another instance of the pattern where we derived a crucible class
from a btrfs struct. Make it an automatic variable instead.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
We only use BtrfsExtentInfo when it's exactly equivalent to the
base, so drop the derived class.
While we're here, fix BtrfsExtentSame::add so it uses a btrfs-compatible
uint64_t instead of an off_t.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
It turns out I've been using pthread_setname_np wrong the whole time:
* on Linux, the thread name length is 15 characters.
TASK_COMM_LEN is 16 bytes, and the last one is always 0.
This is now hardcoded in many places and cannot be changed.
* pthread_setname_np doesn't return -errno, so DIE_IF_MINUS_ERRNO
was the wrong macro. On the other hand, we never want to do anything
differently when pthread_setname_np fails, so we never needed to
check the return value.
Also, libc silently ignores attempts to set the thread name when it is too
long. That's almost certainly a libc bug, but libc probably suppresses
the error result for the same reasons I ignore the error result.
Wrap the pthread_setname function with a C++ std::string overload that
truncates the argument at 15 characters, so we at least get the first
part of the task name in the thread name field. Later commits can deal
with making the bees thread names shorter.
Also wrap pthread_getname for symmetry.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
btrfs-tree provides classes for low-level access to btrfs tree objects.
An item class is provided to decode polymorphic btrfs item fields.
Several tree classes provide forward and backward iteration over raw
object items at different tree levels.
A csum tree class provides convenient access to csums by bytenr,
supporting all current btrfs csum types.
Wrapper classes for inode and subvol items provide direct access to
btrfs metadata fields without clumsy stat() wrappers or ioctls.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
We are using ByteVectors from multiple threads in some cases. Mostly
these are the status and progress threads which read the ByteVector
object references embedded in BEESNOTE macros.
Since it's not clear what the data race implications are, protect
the shared_ptr in ByteVector with a mutex for now.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
Tasks are often running longer than 5 seconds (especially extents with
multiple references requiring copy operations), so the load tracking
algorithm needs to average several samples over a longer period of time
than 5 seconds. If the sample period is 60 seconds, we end up recomputing
the original load average from current_load, so skip the rounding error
and use the original load average value.
Arguably the real fix is to break up the more complex extent operations
over several downstream Task objects, but that's a more significant
design change.
Tweak the attack and decay rates so that threads are started a little
more slowly, but still stopped rapidly when load spikes up.
Remove the hysteresis to provide support for load average targets
below 1, or with fractional components, with a PWM-like effect.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
task1.append(task2) is supposed to run task2 after task1 is executed;
however, if task1 was just executed, and its last reference was owned by
a TaskConsumer, then task2 will be appended to a Task that will never
run again.
A similar problem arises in Exclusion, which can cause blocked tasks
to occasionally be dropped without executing them.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
This was resulting in an assertion failure later on if a queue was
being rescued from a deleted task with only one post-exec queue.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
pause(true) stops the TaskMaster from processing any more Tasks,
but does not destroy any queued Tasks.
pause(false) re-enables Task processing.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
In the event that someday Barrier allows users to force execution of
its pending tasks prior to the destruction of the BarrierState object,
we'll be ready to submit those Tasks for execution without waiting for
the BarrierState mutex lock.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
Exclusion was generating a new Task every time a lock was contended.
That results in thousands of empty Task objects which contain a single
Task item.
Get rid of ExclusionState. Exclusion is now a simple weak_ptr to a Task.
If the weak_ptr is expired, the Exclusion is unlocked. If the weak_ptr
is not expired, it points to the Task which owns the Exclusion.
try_lock now appends the Task attempting to lock the Exclusion directly
to the owning Task, eliminating the need for Exclusion to have one.
This also removes the need to call insert_task separately, though
insert_task remains for other use cases.
With no ExclusionState there is no need for a string argument to
Exclusion's constructor, so get rid of that too.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
Make one class Barrier which is copiable, so we don't have to
have users making shared Barrier all the time.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
For performance or workaround reasons we sometimes have to avoid doing
two conflicting operations at the same time, but we can still run any
number of non-conflicting operations in parallel.
MultiLocker (suggestions for a better class name welcome) blocks the
calling thread until there are no threads attempting to run a conflicting
operation.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
We already had a function that was _similar_, so add decoding for compress
type NONE, give it a less specific name, and declare it in fs.h.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
In commit 14ce81c08 "fs: get rid of silly base class that causes build
failures now" I neglected to set the dest_count field in the ioctl
arg structure, so bees master hasn't been deduping anything for about
three weeks.
I'd put a THROW_CHECK in here to catch this kind of bug in the future,
but it would be placed at exactly the point where this fix is.
Fixes: 14ce81c08
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
Yet another build failure of the form:
error: flexible array member fiemap... not at end of struct crucible::Fiemap...
bees doesn't use fiemap any more, so the fixes here are minimal changes
to make it build, not shining examples of C++ class design.
Signer-off-by: Zygo Blaxell <bees@furryterror.org>
This fixes another build failure of the form:
error: flexible array member btrfs_... not at end of struct crucible::Btrfs...
Fixes: https://github.com/Zygo/bees/issues/236
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
