So I have an awful exercise script that will run snapshot, balance and
send/receive in parallel. This sometimes would crash spectacularly and when it
came back up the fs would be completely hosed. Turns out this is because of a
bad interaction of balance and send/receive. Send will hold onto its entire
path for the whole send, but its blocks could get relocated out from underneath
it, and because it doesn't old tree locks theres nothing to keep this from
happening. So it will go to read in a slot with an old transid, and we could
have re-allocated this block for something else and it could have a completely
different transid. But because we think it is invalid we clear uptodate and
re-read in the block. If we do this before we actually write out the new block
we could write back stale data to the fs, and boom we're screwed.
Now we definitely need to fix this disconnect between send and balance, but we
really really need to not allow ourselves to accidently read in stale data over
new data. So make sure we check if the extent buffer is not under io before
clearing uptodate, this will kick back EIO to the caller instead of reading in
stale data and keep us from corrupting the fs. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Zach found this deadlock that would happen like this
btrfs_end_transaction <- reduce trans->use_count to 0
btrfs_run_delayed_refs
btrfs_cow_block
find_free_extent
btrfs_start_transaction <- increase trans->use_count to 1
allocate chunk
btrfs_end_transaction <- decrease trans->use_count to 0
btrfs_run_delayed_refs
lock tree block we are cowing above ^^
We need to only decrease trans->use_count if it is above 1, otherwise leave it
alone. This will make nested trans be the only ones who decrease their added
ref, and will let us get rid of the trans->use_count++ hack if we have to commit
the transaction. Thanks,
cc: stable@vger.kernel.org
Reported-by: Zach Brown <zab@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Tested-by: Zach Brown <zab@redhat.com>
Signed-off-by: Chris Mason <clm@fb.com>
We needn't flush all delalloc inodes when we doesn't get s_umount lock,
or we would make the tasks wait for a long time.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
If we fail to commit transaction, we'd better
cancel scrub operations.
Suggested-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
btrfs_scrub_continue() will be called when cleaning up transaction.However,
this can only be called if btrfs_scrub_pause() is called before.
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Add noinode_cache mount option for btrfs.
Since inode map cache involves all the btrfs_find_free_ino/return_ino
things and if just trigger the mount_opt,
an inode number get from inode map cache will not returned to inode map
cache.
To keep the find and return inode both in the same behavior,
a new bit in mount_opt, CHANGE_INODE_CACHE, is introduced for this idea.
CHANGE_INODE_CACHE is set/cleared in remounting, and the original
INODE_MAP_CACHE is set/cleared according to CHANGE_INODE_CACHE after a
success transaction.
Since find/return inode is all done between btrfs_start_transaction and
btrfs_commit_transaction, this will keep consistent behavior.
Also noinode_cache mount option will not stop the caching_kthread.
Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
On one of our gluster clusters we noticed some pretty big lag spikes. This
turned out to be because our transaction commit was taking like 3 minutes to
complete. This is because we have like 30 gigs of metadata, so our global
reserve would end up being the max which is like 512 mb. So our throttling code
would allow a ridiculous amount of delayed refs to build up and then they'd all
get run at transaction commit time, and for a cold mounted file system that
could take up to 3 minutes to run. So fix the throttling to be based on both
the size of the global reserve and how long it takes us to run delayed refs.
This patch tracks the time it takes to run delayed refs and then only allows 1
seconds worth of outstanding delayed refs at a time. This way it will auto-tune
itself from cold cache up to when everything is in memory and it no longer has
to go to disk. This makes our transaction commits take much less time to run.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Currently we have two rb-trees, one for delayed ref heads and one for all of the
delayed refs, including the delayed ref heads. When we process the delayed refs
we have to hold onto the delayed ref lock for all of the selecting and merging
and such, which results in quite a bit of lock contention. This was solved by
having a waitqueue and only one flusher at a time, however this hurts if we get
a lot of delayed refs queued up.
So instead just have an rb tree for the delayed ref heads, and then attach the
delayed ref updates to an rb tree that is per delayed ref head. Then we only
need to take the delayed ref lock when adding new delayed refs and when
selecting a delayed ref head to process, all the rest of the time we deal with a
per delayed ref head lock which will be much less contentious.
The locking rules for this get a little more complicated since we have to lock
up to 3 things to properly process delayed refs, but I will address that problem
later. For now this passes all of xfstests and my overnight stress tests.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Looking into some performance related issues with large amounts of metadata
revealed that we can have some pretty huge swings in fsync() performance. If we
have a lot of delayed refs backed up (as you will tend to do with lots of
metadata) fsync() will wander off and try to run some of those delayed refs
which can result in reading from disk and such. Since the actual act of fsync()
doesn't create any delayed refs there is no need to make it throttle on delayed
ref stuff, that will be handled by other people. With this patch we get much
smoother fsync performance with large amounts of metadata. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
We should gurantee that parent and clone roots can not be destroyed
during send, for this we have two ideas.
1.by holding @subvol_sem, this might be a nightmare, because it will
block all subvolumes deletion for a long time.
2.Miao pointed out we can reuse @send_in_progress, that mean we will
skip snapshot deletion if root sending is in progress.
Here we adopt the second approach since it won't block other subvolumes
deletion for a long time.
Besides in btrfs_clean_one_deleted_snapshot(), we only check first root
, if this root is involved in send, we return directly rather than
continue to check.There are several reasons about it:
1.this case happen seldomly.
2.after sending,cleaner thread can continue to drop that root.
3.make code simple
Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Two reasons:
- btrfs_end_transaction_dmeta() is the same as btrfs_end_transaction_throttle()
so it is unnecessary.
- All the delayed items should be dealt in the current transaction, so the
workers should not commit the transaction, instead, deal with the delayed
items as many as possible.
So we can remove btrfs_end_transaction_dmeta()
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
Convert all applicable cases of printk and pr_* to the btrfs_* macros.
Fix all uses of the BTRFS prefix.
Signed-off-by: Frank Holton <fholton@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Just wrap same code into one function scrub_blocked_if_needed().
This make a change that we will move waiting (@workers_pending = 0)
before we can wake up commiting transaction(atomic_inc(@scrub_paused)),
we must take carefully to not deadlock here.
Thread 1 Thread 2
|->btrfs_commit_transaction()
|->set trans type(COMMIT_DOING)
|->btrfs_scrub_paused()(blocked)
|->join_transaction(blocked)
Move btrfs_scrub_paused() before setting trans type which means we can
still join a transaction when commiting_transaction is blocked.
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Suggested-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
The way how we process delayed refs is
1) get a bunch of head refs,
2) pick up one head ref,
3) go one node back for any delayed ref updates.
The head ref is also linked in the same rbtree as the delayed ref is,
so in 1) stage, we have to walk one by one including not only head refs, but
delayed refs.
When we have a great number of delayed refs pending to process,
this'll cost time a lot.
Here we introduce a head ref specific rbtree, it only has head refs, so troubles
go away.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <clm@fb.com>
Lockdep complains about btrfs's async commit:
[ 2372.462171] [ BUG: bad unlock balance detected! ]
[ 2372.462191] 3.12.0+ #32 Tainted: G W
[ 2372.462209] -------------------------------------
[ 2372.462228] ceph-osd/14048 is trying to release lock (sb_internal) at:
[ 2372.462275] [<ffffffffa022cb10>] btrfs_commit_transaction_async+0x1b0/0x2a0 [btrfs]
[ 2372.462305] but there are no more locks to release!
[ 2372.462324]
[ 2372.462324] other info that might help us debug this:
[ 2372.462349] no locks held by ceph-osd/14048.
[ 2372.462367]
[ 2372.462367] stack backtrace:
[ 2372.462386] CPU: 2 PID: 14048 Comm: ceph-osd Tainted: G W 3.12.0+ #32
[ 2372.462414] Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./To be filled by O.E.M., BIOS 080015 11/09/2011
[ 2372.462455] ffffffffa022cb10 ffff88007490fd28 ffffffff816f094a ffff8800378aa320
[ 2372.462491] ffff88007490fd50 ffffffff810adf4c ffff8800378aa320 ffff88009af97650
[ 2372.462526] ffffffffa022cb10 ffff88007490fd88 ffffffff810b01ee ffff8800898c0000
[ 2372.462562] Call Trace:
[ 2372.462584] [<ffffffffa022cb10>] ? btrfs_commit_transaction_async+0x1b0/0x2a0 [btrfs]
[ 2372.462619] [<ffffffff816f094a>] dump_stack+0x45/0x56
[ 2372.462642] [<ffffffff810adf4c>] print_unlock_imbalance_bug+0xec/0x100
[ 2372.462677] [<ffffffffa022cb10>] ? btrfs_commit_transaction_async+0x1b0/0x2a0 [btrfs]
[ 2372.462710] [<ffffffff810b01ee>] lock_release+0x18e/0x210
[ 2372.462742] [<ffffffffa022cb36>] btrfs_commit_transaction_async+0x1d6/0x2a0 [btrfs]
[ 2372.462783] [<ffffffffa025a7ce>] btrfs_ioctl_start_sync+0x3e/0xc0 [btrfs]
[ 2372.462822] [<ffffffffa025f1d3>] btrfs_ioctl+0x4c3/0x1f70 [btrfs]
[ 2372.462849] [<ffffffff812c0321>] ? avc_has_perm+0x121/0x1b0
[ 2372.462873] [<ffffffff812c0224>] ? avc_has_perm+0x24/0x1b0
[ 2372.462897] [<ffffffff8107ecc8>] ? sched_clock_cpu+0xa8/0x100
[ 2372.462922] [<ffffffff8117b145>] do_vfs_ioctl+0x2e5/0x4e0
[ 2372.462946] [<ffffffff812c19e6>] ? file_has_perm+0x86/0xa0
[ 2372.462969] [<ffffffff8117b3c1>] SyS_ioctl+0x81/0xa0
[ 2372.462991] [<ffffffff817045a4>] tracesys+0xdd/0xe2
====================================================
It's because that we don't do the right thing when checking if it's ok to
tell lockdep that we're trying to release the rwsem.
If the trans handle's type is TRANS_ATTACH, we won't acquire the freeze rwsem, but
as TRANS_ATTACH fits the check (trans < TRANS_JOIN_NOLOCK), we'll release the freeze
rwsem, which makes lockdep complains a lot.
Reported-by: Ma Jianpeng <majianpeng@gmail.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
rename the function -- btrfs_start_all_delalloc_inodes(), and make its
name be compatible to btrfs_wait_ordered_roots(), since they are always
used at the same place.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
It is very likely that there are lots of ordered extents in the filesytem,
if we wait for the completion of all of them when we want to reclaim some
space for the metadata space reservation, we would be blocked for a long
time. The performance would drop down suddenly for a long time.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
When we did space balance and snapshot creation at the same time, we might
meet the following oops:
kernel BUG at fs/btrfs/inode.c:3038!
[SNIP]
Call Trace:
[<ffffffffa0411ec7>] btrfs_orphan_cleanup+0x293/0x407 [btrfs]
[<ffffffffa042dc45>] btrfs_mksubvol.isra.28+0x259/0x373 [btrfs]
[<ffffffffa042de85>] btrfs_ioctl_snap_create_transid+0x126/0x156 [btrfs]
[<ffffffffa042dff1>] btrfs_ioctl_snap_create_v2+0xd0/0x121 [btrfs]
[<ffffffffa0430b2c>] btrfs_ioctl+0x414/0x1854 [btrfs]
[<ffffffff813b60b7>] ? __do_page_fault+0x305/0x379
[<ffffffff811215a9>] vfs_ioctl+0x1d/0x39
[<ffffffff81121d7c>] do_vfs_ioctl+0x32d/0x3e2
[<ffffffff81057fe7>] ? finish_task_switch+0x80/0xb8
[<ffffffff81121e88>] SyS_ioctl+0x57/0x83
[<ffffffff813b39ff>] ? do_device_not_available+0x12/0x14
[<ffffffff813b99c2>] system_call_fastpath+0x16/0x1b
[SNIP]
RIP [<ffffffffa040da40>] btrfs_orphan_add+0xc3/0x126 [btrfs]
The reason of the problem is that the relocation root creation stole
the reserved space, which was reserved for orphan item deletion.
There are several ways to fix this problem, one is to increasing
the reserved space size of the space balace, and then we can use
that space to create the relocation tree for each fs/file trees.
But it is hard to calculate the suitable size because we doesn't
know how many fs/file trees we need relocate.
We fixed this problem by reserving the space for relocation root creation
actively since the space it need is very small (one tree block, used for
root node copy), then we use that reserved space to create the
relocation tree. If we don't reserve space for relocation tree creation,
we will use the reserved space of the balance.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
I was noticing the slab redzone stuff going off every once and a while during
transaction aborts. This was caused by two things
1) We would walk the pending snapshots and set their error to -ECANCELED. We
don't need to do this, the snapshot stuff waits for a transaction commit and if
there is a problem we just free our pending snapshot object and exit. Doing
this was causing us to touch the pending snapshot object after the thing had
already been freed.
2) We were freeing the transaction manually with wanton disregard for it's
use_count reference counter. To fix this I cleaned up the transaction freeing
loop to either wait for the transaction commit to finish if it was in the middle
of that (since it will be cleaned and freed up there) or to do the cleanup
oursevles.
I also moved the global "kill all things dirty everywhere" stuff outside of the
transaction cleanup loop since that only needs to be done once. With this patch
I'm no longer seeing slab corruption because of use after frees. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Noticed this when forcing errors to happen during delayed ref running. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
If we abort not during a transaction commit we won't clean up anything until we
unmount. Unfortunately if we abort in the middle of writing out an ordered
extent we won't clean it up and if somebody is waiting on that ordered extent
they will wait forever. To fix this just make the transaction kthread call the
cleanup transaction stuff if it notices theres an error, and make
btrfs_end_transaction wake up the transaction kthread if there is an error.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
If we abort a transaction in the middle of a commit we weren't undoing the
intwrite locking. This patch fixes that problem.
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
If we crash with a log, remount and recover that log, and then crash before we
can commit another transaction we will get transid verify errors on the next
mount. This is because we were not zero'ing out the log when we committed the
transaction after recovery. This is ok as long as we commit another transaction
at some point in the future, but if you abort or something else goes wrong you
can end up in this weird state because the recovery stuff says that the tree log
should have a generation+1 of the super generation, which won't be the case of
the transaction that was started for recovery. Fix this by removing the check
and _always_ zero out the log portion of the super when we commit a transaction.
This fixes the transid verify issues I was seeing with my force errors tests.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
This is a left over of how we used to wait for ordered extents, which was to
grab the inode and then run filemap flush on it. However if we have an ordered
extent then we already are holding a ref on the inode, and we just use
btrfs_start_ordered_extent anyway, so there is no reason to have an extra ref on
the inode to start work on the ordered extent. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
u64 is "unsigned long long" on all architectures now, so there's no need to
cast it when formatting it using the "ll" length modifier.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
If the filesystem was mounted with an old kernel that was not
aware of the UUID tree, this is detected by looking at the
uuid_tree_generation field of the superblock (similar to how
the free space cache is doing it). If a mismatch is detected
at mount time, a thread is started that does two things:
1. Iterate through the UUID tree, check each entry, delete those
entries that are not valid anymore (i.e., the subvol does not
exist anymore or the value changed).
2. Iterate through the root tree, for each found subvolume, add
the UUID tree entries for the subvolume (if they are not
already there).
This mechanism is also used to handle and repair errors that
happened during the initial creation and filling of the tree.
The update of the uuid_tree_generation field (which indicates
that the state of the UUID tree is up to date) is blocked until
all create and repair operations are successfully completed.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
In order to be able to detect the case that a filesystem is mounted
with an old kernel, add a uuid-tree-gen field like the free space
cache is doing it. It is part of the super block and written with
each commit. Old kernels do not know this field and don't update it.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
When a new subvolume or snapshot is created, a new UUID item is added
to the UUID tree. Such items are removed when the subvolume is deleted.
The ioctl to set the received subvolume UUID is also touched and will
now also add this received UUID into the UUID tree together with the
ID of the subvolume. The latter is also done when read-only snapshots
are created which inherit all the send/receive information from the
parent subvolume.
User mode programs use the BTRFS_IOC_TREE_SEARCH ioctl to search and
read in the UUID tree.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Cc: Josef Bacik <jbacik@fusionio.com>
Cc: Chris Mason <chris.mason@fusionio.com>
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
There is no reason for this sort of jackassery. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Some codes still use the cpu_to_lexx instead of the
BTRFS_SETGET_STACK_FUNCS declared in ctree.h.
Also added some BTRFS_SETGET_STACK_FUNCS for btrfs_header btrfs_timespec
and other structures.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Miao Xie <miaoxie@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
A user reported a panic when running with autodefrag and deleting snapshots.
This is because we could end up trying to add the root to the dead roots list
twice. To fix this check to see if we are empty before adding ourselves to the
dead roots list. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
When adjusting the enospc rules for relocation I ran into a deadlock because we
were relocating the only system chunk and that forced us to try and allocate a
new system chunk while holding locks in the chunk tree, which caused us to
deadlock. To fix this I've moved all of the dev extent addition and chunk
addition out to the delayed chunk completion stuff. We still keep the in-memory
stuff which makes sure everything is consistent.
One change I had to make was to search the commit root of the device tree to
find a free dev extent, and hold onto any chunk em's that we allocated in that
transaction so we do not allocate the same dev extent twice. This has the side
effect of fixing a bug with balance that has been there ever since balance
existed. Basically you can free a block group and it's dev extent and then
immediately allocate that dev extent for a new block group and write stuff to
that dev extent, all within the same transaction. So if you happen to crash
during a balance you could come back to a completely broken file system. This
patch should keep these sort of things from happening in the future since we
won't be able to allocate free'd dev extents until after the transaction
commits. This has passed all of the xfstests and my super annoying stress test
followed by a balance. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
The comment is for btrfs_attach_transaction_barrier, not for
btrfs_attach_transaction. Fix the typo.
Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Acked-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Dave has this fs_mark script that can make btrfs abort with sufficient amount of
ram. This is because with more ram we can keep more dirty metadata in cache
which in a round about way makes for many more pending delayed refs. What
happens is we end up not throttling the transaction enough so when we go to
commit the transaction when we've completely filled the file system we'll
abort() because we use all of the space in the global reserve and we still have
delayed refs to run. To fix this we need to make the delayed ref flushing and
the transaction throttling dependant upon the number of delayed refs that we
have instead of how much reserved space is left in the global reserve. With
this patch we not only stop aborting transactions but we also get a smoother run
speed with fs_mark and it makes us about 10% faster. Thanks,
Reported-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
I hit a hang when run_delayed_refs returned an error in the beginning of
btrfs_commit_transaction. If we decide we need to commit the transaction in
btrfs_end_transaction we'll set BLOCKED and start to commit, but if we get an
error this early on we'll just exit without committing. This is fine, except
that anybody else who tried to start a transaction will sit in
wait_current_trans() since we're set to BLOCKED and we never set it to something
else and woke people up. To fix this we want to check for trans->aborted
everywhere we wait for the transaction state to change, and make
btrfs_abort_transaction() wake up any waiters there may be. All the callers
will notice that the transaction has aborted and exit out properly. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Before applying this patch, we flushed the log tree of the fs/file
tree firstly, and then flushed the log root tree. It is ineffective,
especially on the hard disk. This patch improved this problem by wrapping
the above two flushes by the same blk_plug.
By test, the performance of the sync write went up ~60%(2.9MB/s -> 4.6MB/s)
on my scsi disk whose disk buffer was enabled.
Test step:
# mkfs.btrfs -f -m single <disk>
# mount <disk> <mnt>
# dd if=/dev/zero of=<mnt>/file0 bs=32K count=1024 oflag=sync
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
We used 3 variants to track the state of the transaction, it was complex
and wasted the memory space. Besides that, it was hard to understand that
which types of the transaction handles should be blocked in each transaction
state, so the developers often made mistakes.
This patch improved the above problem. In this patch, we define 6 states
for the transaction,
enum btrfs_trans_state {
TRANS_STATE_RUNNING = 0,
TRANS_STATE_BLOCKED = 1,
TRANS_STATE_COMMIT_START = 2,
TRANS_STATE_COMMIT_DOING = 3,
TRANS_STATE_UNBLOCKED = 4,
TRANS_STATE_COMPLETED = 5,
TRANS_STATE_MAX = 6,
}
and just use 1 variant to track those state.
In order to make the blocked handle types for each state more clear,
we introduce a array:
unsigned int btrfs_blocked_trans_types[TRANS_STATE_MAX] = {
[TRANS_STATE_RUNNING] = 0U,
[TRANS_STATE_BLOCKED] = (__TRANS_USERSPACE |
__TRANS_START),
[TRANS_STATE_COMMIT_START] = (__TRANS_USERSPACE |
__TRANS_START |
__TRANS_ATTACH),
[TRANS_STATE_COMMIT_DOING] = (__TRANS_USERSPACE |
__TRANS_START |
__TRANS_ATTACH |
__TRANS_JOIN),
[TRANS_STATE_UNBLOCKED] = (__TRANS_USERSPACE |
__TRANS_START |
__TRANS_ATTACH |
__TRANS_JOIN |
__TRANS_JOIN_NOLOCK),
[TRANS_STATE_COMPLETED] = (__TRANS_USERSPACE |
__TRANS_START |
__TRANS_ATTACH |
__TRANS_JOIN |
__TRANS_JOIN_NOLOCK),
}
it is very intuitionistic.
Besides that, because we remove ->in_commit in transaction structure, so
the lock ->commit_lock which was used to protect it is unnecessary, remove
->commit_lock.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
We checked the commit time to avoid committing the transaction
frequently, but it is unnecessary because:
- It made the transaction commit spend more time, and delayed the
operation of the external writers(TRANS_START/TRANS_USERSPACE).
- Except the space that we have to commit transaction, such as
snapshot creation, btrfs doesn't commit the transaction on its
own initiative.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
We used ->num_joined track if there were some writers which join the current
transaction when the committer was sleeping. If some writers joined the current
transaction, we has to continue the while loop to do some necessary stuff, such
as flush the ordered operations. But it is unnecessary because we will do it
after the while loop.
Besides that, tracking ->num_joined would make the committer drop into the while
loop when there are lots of internal writers(TRANS_JOIN).
So we remove ->num_joined and don't track if there are some writers which join
the current transaction when the committer is sleeping.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
It is unnecessary to flush the delalloc inodes again and again because
we don't care the dirty pages which are introduced after the flush, and
they will be flush in the transaction commit.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
btrfs_commit_transaction has the following loop before we commit the
transaction.
do {
// attempt to do some useful stuff and/or sleep
} while (atomic_read(&cur_trans->num_writers) > 1 ||
(should_grow && cur_trans->num_joined != joined));
This is used to prevent from the TRANS_START to get in the way of a
committing transaction. But it does not prevent from TRANS_JOIN, that
is we would do this loop for a long time if some writers JOIN the
current transaction endlessly.
Because we need join the current transaction to do some useful stuff,
we can not block TRANS_JOIN here. So we introduce a external writer
counter, which is used to count the TRANS_USERSPACE/TRANS_START writers.
If the external writer counter is zero, we can break the above loop.
In order to make the code more clear, we don't use enum variant
to define the type of the transaction handle, use bitmask instead.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
If the transaction is removed from the transaction list, it means the
transaction has been committed successfully. So it is impossible to
call cleanup_transaction(), otherwise there is something wrong with
the code logic. Thus, we use BUG_ON() instead of the original handle.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Before applying this patch, we need flush all the delalloc inodes in
the fs when we want to create a snapshot, it wastes time, and make
the transaction commit be blocked for a long time. It means some other
user operation would also be blocked for a long time.
This patch improves this problem, we just flush the delalloc inodes that
in the source trees before snapshot creation, so the transaction commit
will complete quickly.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
The reason we introduce per-subvolume ordered extent list is the same
as the per-subvolume delalloc inode list.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
When we create a snapshot, we need flush all delalloc inodes in the
fs, just flushing the inodes in the source tree is OK. So we introduce
per-subvolume delalloc inode list.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
If the fs is remounted to be R/O, it is unnecessary to call
btrfs_clean_one_deleted_snapshot(), so move the R/O check out of
this function. And besides that, it can make the check logic in the
caller more clear.
Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Big patch, but all it does is add statics to functions which
are in fact static, then remove the associated dead-code fallout.
removed functions:
btrfs_iref_to_path()
__btrfs_lookup_delayed_deletion_item()
__btrfs_search_delayed_insertion_item()
__btrfs_search_delayed_deletion_item()
find_eb_for_page()
btrfs_find_block_group()
range_straddles_pages()
extent_range_uptodate()
btrfs_file_extent_length()
btrfs_scrub_cancel_devid()
btrfs_start_transaction_lflush()
btrfs_print_tree() is left because it is used for debugging.
btrfs_start_transaction_lflush() and btrfs_reada_detach() are
left for symmetry.
ulist.c functions are left, another patch will take care of those.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Sequence numbers for delayed refs have been introduced in the first version
of the qgroup patch set. To solve the problem of find_all_roots on a busy
file system, the tree mod log was introduced. The sequence numbers for that
were simply shared between those two users.
However, at one point in qgroup's quota accounting, there's a statement
accessing the previous sequence number, that's still just doing (seq - 1)
just as it would have to in the very first version.
To satisfy that requirement, this patch makes the sequence number counter 64
bit and splits it into a major part (used for qgroup sequence number
counting) and a minor part (incremented for each tree modification in the
log). This enables us to go exactly one major step backwards, as required
for qgroups, while still incrementing the sequence counter for tree mod log
insertions to keep track of their order. Keeping them in a single variable
means there's no need to change all the code dealing with comparisons of two
sequence numbers.
The sequence number is reset to 0 on commit (not new in this patch), which
ensures we won't overflow the two 32 bit counters.
Without this fix, the qgroup tracking can occasionally go wrong and WARN_ONs
from the tree mod log code may happen.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Josef Bacik
Miao Xie
Wang Shilong
Qu Wenruo
Frank Holton
Liu Bo
Filipe David Borba Manana
Josef Bacik
Geert Uytterhoeven
Stefan Behrens
Sergei Trofimovich
Wang Sheng-Hui
Eric Sandeen
Jan Schmidt