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  1. 26 7月, 2016 19 次提交
  3. 21 7月, 2016 2 次提交
    • C
      Btrfs: fix delalloc accounting after copy_from_user faults · 8b8b08cb
      由 Chris Mason 提交于 
      Commit 56244ef1 was almost but not quite enough to fix the
reservation math after btrfs_copy_from_user returned partial copies.

Some users are still seeing warnings in btrfs_destroy_inode, and with a
long enough test run I'm able to trigger them as well.

This patch fixes the accounting math again, bringing it much closer to
the way it was before the sectorsize conversion Chandan did.  The
problem is accounting for the offset into the page/sector when we do a
partial copy.  This one just uses the dirty_sectors variable which
should already be updated properly.
Signed-off-by: NChris Mason <clm@fb.com>
cc: stable@vger.kernel.org # v4.6+
      8b8b08cb
    • J
      Btrfs: avoid deadlocks during reservations in btrfs_truncate_block · bac357dc
      由 Josef Bacik 提交于 
      The new enospc code makes it possible to deadlock if we don't use
FLUSH_LIMIT during reservations inside a transaction.  This enforces
the correct flush type to avoid both deadlocks and assertions
Signed-off-by: NChris Mason <clm@fb.com>
Signed-off-by: NJosef Bacik <jbacik@fb.com>
      bac357dc
  5. 08 7月, 2016 17 次提交
    • J
      Btrfs: use FLUSH_LIMIT for relocation in reserve_metadata_bytes · 8ca17f0f
      由 Josef Bacik 提交于 
      We used to allow you to set FLUSH_ALL and then just wouldn't do things like
commit transactions or wait on ordered extents if we noticed you were in a
transaction.  However now that all the flushing for FLUSH_ALL is asynchronous
we've lost the ability to tell, and we could end up deadlocking.  So instead use
FLUSH_LIMIT in reserve_metadata_bytes in relocation and then return -EAGAIN if
we error out to preserve the previous behavior.  I've also added an ASSERT() to
catch anybody else who tries to do this.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      8ca17f0f
    • J
      Btrfs: fill relocation block rsv after allocation · ac2fabac
      由 Josef Bacik 提交于 
      Since we set the reloc control before we've reserved our space for relocation we
could race with a root being dirtied and not actually have space to do our init
reloc root.  So once we've allocated it and set it up go ahead and make our
reservation before setting the relocate control, that way anybody who tries to
do the reloc root init has space to use.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      ac2fabac
    • J
      Btrfs: always use trans->block_rsv for orphans · 40acc3ee
      由 Josef Bacik 提交于 
      This is the case all the time anyway except for relocation which could be doing
a reloc root for a non ref counted root, in which case we'd end up with some
random block rsv rather than the one we have our reservation in.  If there isn't
enough space in the block rsv we are trying to steal from we'll BUG() because we
expect there to be space for the orphan to make its reservation.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      40acc3ee
    • J
      Btrfs: change how we calculate the global block rsv · ae2e4728
      由 Josef Bacik 提交于 
      Traditionally we've calculated the global block rsv by guessing how much of the
metadata used amount was the extent tree, and then taking the data size and
figuring out how large the csum tree would have to be to hold that much data.

This is imprecise and falls down on MIXED file systems as we can't trust the
data used amount.  This resulted in failures for xfstests generic/333 because it
creates lots of clones, which explodes out the extent tree.  Our global reserve
calculations were woefully inaccurate in this case which meant we got into a
situation where we did not have enough reserved to do our work.

We know we only use the global block rsv for the extent, csum, and root trees,
so just get the bytes used for these trees and use that as the basis of our
global reserve.  Since these are not reference counted trees the bytes_used
value will be accurate.  This fixed the transaction aborts seen with
generic/333.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      ae2e4728
    • J
      Btrfs: use root when checking need_async_flush · 87241c2e
      由 Josef Bacik 提交于 
      Instead of doing fs_info->fs_root in need_async_flush, which may not be set
during recovery when mounting, just pass the root itself in, which makes more
sense as thats what btrfs_calc_reclaim_metadata_size takes.
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Reported-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      87241c2e
    • J
      Btrfs: don't bother kicking async if there's nothing to reclaim · d38b349c
      由 Josef Bacik 提交于 
      We do this check when we start the async reclaimer thread, might as well check
before we kick it off to save us some cycles.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      d38b349c
    • J
      Btrfs: fix release reserved extents trace points · 31bada7c
      由 Josef Bacik 提交于 
      We were doing trace_btrfs_release_reserved_extent() in pin_down_extent which
isn't quite right because we will go through and free that extent later when we
unpin, so it messes up apps that are accounting for the reservation space.  We
were also unconditionally doing it in __btrfs_free_reserved_extent(), when we
only actually free the reservation instead of pinning the extent.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      31bada7c
    • J
      Btrfs: add tracepoints for flush events · f376df2b
      由 Josef Bacik 提交于 
      We want to track when we're triggering flushing from our reservation code and
what flushing is being done when we start flushing.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      f376df2b
    • J
      Btrfs: fix delalloc reservation amount tracepoint · f485c9ee
      由 Josef Bacik 提交于 
      We can sometimes drop the reservation we had for our inode, so we need to remove
that amount from to_reserve so that our tracepoint reports a valid amount of
space.
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      f485c9ee
    • J
      Btrfs: trace pinned extents · c51e7bb1
      由 Josef Bacik 提交于 
      Pinned extents are an important metric to keep track of for enospc.
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      c51e7bb1
    • J
      Btrfs: introduce ticketed enospc infrastructure · 957780eb
      由 Josef Bacik 提交于 
      Our enospc flushing sucks.  It is born from a time where we were early
enospc'ing constantly because multiple threads would race in for the same
reservation and randomly starve other ones out.  So I came up with this solution
to block any other reservations from happening while one guy tried to flush
stuff to satisfy his reservation.  This gives us pretty good correctness, but
completely crap latency.

The solution I've come up with is ticketed reservations.  Basically we try to
make our reservation, and if we can't we put a ticket on a list in order and
kick off an async flusher thread.  This async flusher thread does the same old
flushing we always did, just asynchronously.  As space is freed and added back
to the space_info it checks and sees if we have any tickets that need
satisfying, and adds space to the tickets and wakes up anything we've satisfied.

Once the flusher thread stops making progress it wakes up all the current
tickets and tells them to take a hike.

There is a priority list for things that can't flush, since the async flusher
could do anything we need to avoid deadlocks.  These guys get priority for
having their reservation made, and will still do manual flushing themselves in
case the async flusher isn't running.

This patch gives us significantly better latencies.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      957780eb
    • J
      Btrfs: add tracepoint for adding block groups · c83f8eff
      由 Josef Bacik 提交于 
      I'm writing a tool to visualize the enospc system inside btrfs, I need this
tracepoint in order to keep track of the block groups in the system.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      c83f8eff
    • J
      Btrfs: warn_on for unaccounted spaces · d555b6c3
      由 Josef Bacik 提交于 
      These were hidden behind enospc_debug, which isn't helpful as they indicate
actual bugs, unlike the rest of the enospc_debug stuff which is really debug
information.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      d555b6c3
    • J
      Btrfs: change delayed reservation fallback behavior · c48f49d6
      由 Josef Bacik 提交于 
      We reserve space for the inode update when we first reserve space for writing to
a file.  However there are lots of ways that we can use this reservation and not
have it for subsequent ordered extents.  Previously we'd fall through and try to
reserve metadata bytes for this, then we'd just steal the full reservation from
the delalloc_block_rsv, and if that didn't have enough space we'd steal the full
reservation from the global reserve.  The problem with this is we can easily
just return ENOSPC and fallback to updating the inode item directly.  In the
worst case (assuming 4k nodesize) we'd steal 64kib from the global reserve if we
fall all the way through, however if we just fallback and update the inode
directly we'd only steal 4k * BTRFS_PATH_MAX in the worst case which is 32kib.

We would have also just added the extent item for the inode so we likely will
have already cow'ed down most of the way to the leaf containing the inode item,
so we are more often than not only need one or two nodesize's worth of
reservations.  Given the reservation for the extent itself is also a worst case
we will likely already have space to cover the inode update.

This change will make us behave better in the theoretical worst case, and much
better in the case that we don't have our reservation and cannot reserve more
metadata.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      c48f49d6
    • J
      Btrfs: always reserve metadata for delalloc extents · 48c3d480
      由 Josef Bacik 提交于 
      There are a few races in the metadata reservation stuff.  First we add the bytes
to the block_rsv well after we've set the bit on the inode saying that we have
space for it and after we've reserved the bytes.  So use the normal
btrfs_block_rsv_add helper for this case.  Secondly we can flush delalloc
extents when we try to reserve space for our write, which means that we could
have used up the space for the inode and we wouldn't know because we only check
before the reservation.  So instead make sure we are always reserving space for
the inode update, and then if we don't need it release those bytes afterward.
Thanks,
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      48c3d480
    • J
      Btrfs: fix callers of btrfs_block_rsv_migrate · 25d609f8
      由 Josef Bacik 提交于 
      So btrfs_block_rsv_migrate just unconditionally calls block_rsv_migrate_bytes.
Not only this but it unconditionally changes the size of the block_rsv.  This
isn't a bug strictly speaking, but it makes truncate block rsv's look funny
because every time we migrate bytes over its size grows, even though we only
want it to be a specific size.  So collapse this into one function that takes an
update_size argument and make truncate and evict not update the size for
consistency sake.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      25d609f8
    • J
      Btrfs: add bytes_readonly to the spaceinfo at once · e40edf2d
      由 Josef Bacik 提交于 
      For some reason we're adding bytes_readonly to the space info after we update
the space info with the block group info.  This creates a tiny race where we
could over-reserve space because we haven't yet taken out the bytes_readonly
bit.  Since we already know this information at the time we call
update_space_info, just pass it along so it can be updated all at once.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      e40edf2d
  7. 25 6月, 2016 1 次提交
    • O
      Btrfs: fix ->iterate_shared() by upgrading i_rwsem for delayed nodes · 02dbfc99
      由 Omar Sandoval 提交于 
      Commit fe742fd4 ("Revert "btrfs: switch to ->iterate_shared()"")
backed out the conversion to ->iterate_shared() for Btrfs because the
delayed inode handling in btrfs_real_readdir() is racy. However, we can
still do readdir in parallel if there are no delayed nodes.

This is a temporary fix which upgrades the shared inode lock to an
exclusive lock only when we have delayed items until we come up with a
more complete solution. While we're here, rename the
btrfs_{get,put}_delayed_items functions to make it very clear that
they're just for readdir.

Tested with xfstests and by doing a parallel kernel build:

	while make tinyconfig && make -j4 && git clean dqfx; do
		:
	done

along with a bunch of parallel finds in another shell:

	while true; do
		for ((i=0; i<4; i++)); do
			find . >/dev/null &
		done
		wait
	done
Signed-off-by: NOmar Sandoval <osandov@fb.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NChris Mason <clm@fb.com>
      02dbfc99
  9. 24 6月, 2016 1 次提交