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>
For created snapshots, the full root_item is copied from the source
root and afterwards selectively modified. The current code forgets
to clear the field received_uuid. The only problem is that it is
confusing when you look at it with 'btrfs subv list', since for
writable snapshots, the contents of the snapshot can be completely
unrelated to the previously received snapshot.
The receiver ignores such snapshots anyway because he also checks
the field stransid in the root_item and that value used to be reset
to zero for all created snapshots.
This commit changes two things:
- clear the received_uuid field for new writable snapshots.
- don't clear the send/receive related information like the stransid
for read-only snapshots (which makes them useable as a parent for
the automatic selection of parents in the receive code).
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Testing my enospc log code I managed to abort a transaction during mount, which
put me into an infinite loop. This is because of two things, first we don't
reset trans_no_join if we abort during transaction commit, which will force
anybody trying to start a transaction to just loop endlessly waiting for it to
be set to 0. But this is still just a symptom, the second issue is we don't set
the fs state to error during errors on mount. This is because we don't want to
do the flip read only thing during mount, but we still really want to set the fs
state to an error to keep us from even getting to the trans_no_join check. So
fix both of these things, make sure to reset trans_no_join if we abort during a
commit, and make sure we set the fs state to error no matter if we're mounting
or not. This should keep us from getting into this infinite loop again.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
With more than one btrfs volume mounted, it can be very difficult to find
out which volume is hitting an error. btrfs_error() will print this, but
it is currently rigged as more of a fatal error handler, while many of
the printk()s are currently for debugging and yet-unhandled cases.
This patch just changes the functions where the device information is
already available. Some cases remain where the root or fs_info is not
passed to the function emitting the error.
This may introduce some confusion with volumes backed by multiple devices
emitting errors referring to the primary device in the set instead of the
one on which the error occurred.
Use btrfs_printk(fs_info, format, ...) rather than writing the device
string every time, and introduce macro wrappers ala XFS for brevity.
Since the function already cannot be used for continuations, print a
newline as part of the btrfs_printk() message rather than at each caller.
Signed-off-by: Simon Kirby <sim@hostway.ca>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Each time pick one dead root from the list and let the caller know if
it's needed to continue. This should improve responsiveness during
umount and balance which at some point waits for cleaning all currently
queued dead roots.
A new dead root is added to the end of the list, so the snapshots
disappear in the order of deletion.
The snapshot cleaning work is now done only from the cleaner thread and the
others wake it if needed.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
The transaction abort stacktrace is printed only once per module
lifetime, but we'd like to see it each time it happens per mounted
filesystem. Introduce a fs_state flag that records it.
Tweak the messages around abort:
* add error number to the first abort
* print the exact negative errno from btrfs_decode_error
* clean up btrfs_decode_error and callers
* no dots at the end of the messages
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Pull btrfs fixes from Chris Mason:
"Eric's rcu barrier patch fixes a long standing problem with our
unmount code hanging on to devices in workqueue helpers. Liu Bo
nailed down a difficult assertion for in-memory extent mappings."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: fix warning of free_extent_map
Btrfs: fix warning when creating snapshots
Btrfs: return as soon as possible when edquot happens
Btrfs: return EIO if we have extent tree corruption
btrfs: use rcu_barrier() to wait for bdev puts at unmount
Btrfs: remove btrfs_try_spin_lock
Btrfs: get better concurrency for snapshot-aware defrag work
Creating snapshot passes extent_root to commit its transaction,
but it can lead to the warning of checking root for quota in
the __btrfs_end_transaction() when someone else is committing
the current transaction. Since we've recorded the needed root
in trans_handle, just use it to get rid of the warning.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Pull btrfs fixes from Chris Mason:
"These are scattered fixes and one performance improvement. The
biggest functional change is in how we throttle metadata changes. The
new code bumps our average file creation rate up by ~13% in fs_mark,
and lowers CPU usage.
Stefan bisected out a regression in our allocation code that made
balance loop on extents larger than 256MB."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: improve the delayed inode throttling
Btrfs: fix a mismerge in btrfs_balance()
Btrfs: enforce min_bytes parameter during extent allocation
Btrfs: allow running defrag in parallel to administrative tasks
Btrfs: avoid deadlock on transaction waiting list
Btrfs: do not BUG_ON on aborted situation
Btrfs: do not BUG_ON in prepare_to_reloc
Btrfs: free all recorded tree blocks on error
Btrfs: build up error handling for merge_reloc_roots
Btrfs: check for NULL pointer in updating reloc roots
Btrfs: fix unclosed transaction handler when the async transaction commitment fails
Btrfs: fix wrong handle at error path of create_snapshot() when the commit fails
Btrfs: use set_nlink if our i_nlink is 0
Only let one trans handle to wait for other handles, otherwise we
will get ABBA issues.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
There are several bugs at error path of create_snapshot() when the
transaction commitment failed.
- access the freed transaction handler. At the end of the
transaction commitment, the transaction handler was freed, so we
should not access it after the transaction commitment.
- we were not aware of the error which happened during the snapshot
creation if we submitted a async transaction commitment.
- pending snapshot access vs pending snapshot free. when something
wrong happened after we submitted a async transaction commitment,
the transaction committer would cleanup the pending snapshots and
free them. But the snapshot creators were not aware of it, they
would access the freed pending snapshots.
This patch fixes the above problems by:
- remove the dangerous code that accessed the freed handler
- assign ->error if the error happens during the snapshot creation
- the transaction committer doesn't free the pending snapshots,
just assigns the error number and evicts them before we unblock
the transaction.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Pull btrfs update from Chris Mason:
"The biggest feature in the pull is the new (and still experimental)
raid56 code that David Woodhouse started long ago. I'm still working
on the parity logging setup that will avoid inconsistent parity after
a crash, so this is only for testing right now. But, I'd really like
to get it out to a broader audience to hammer out any performance
issues or other problems.
scrub does not yet correct errors on raid5/6 either.
Josef has another pass at fsync performance. The big change here is
to combine waiting for metadata with waiting for data, which is a big
latency win. It is also step one toward using atomics from the
hardware during a commit.
Mark Fasheh has a new way to use btrfs send/receive to send only the
metadata changes. SUSE is using this to make snapper more efficient
at finding changes between snapshosts.
Snapshot-aware defrag is also included.
Otherwise we have a large number of fixes and cleanups. Eric Sandeen
wins the award for removing the most lines, and I'm hoping we steal
this idea from XFS over and over again."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (118 commits)
btrfs: fixup/remove module.h usage as required
Btrfs: delete inline extents when we find them during logging
btrfs: try harder to allocate raid56 stripe cache
Btrfs: cleanup to make the function btrfs_delalloc_reserve_metadata more logic
Btrfs: don't call btrfs_qgroup_free if just btrfs_qgroup_reserve fails
Btrfs: remove reduplicate check about root in the function btrfs_clean_quota_tree
Btrfs: return ENOMEM rather than use BUG_ON when btrfs_alloc_path fails
Btrfs: fix missing deleted items in btrfs_clean_quota_tree
btrfs: use only inline_pages from extent buffer
Btrfs: fix wrong reserved space when deleting a snapshot/subvolume
Btrfs: fix wrong reserved space in qgroup during snap/subv creation
Btrfs: remove unnecessary dget_parent/dput when creating the pending snapshot
btrfs: remove a printk from scan_one_device
Btrfs: fix NULL pointer after aborting a transaction
Btrfs: fix memory leak of log roots
Btrfs: copy everything if we've created an inline extent
btrfs: cleanup for open-coded alignment
Btrfs: do not change inode flags in rename
Btrfs: use reserved space for creating a snapshot
clear chunk_alloc flag on retryable failure
...
There are two problems in the space reservation of the snapshot/
subvolume creation.
- don't reserve the space for the root item insertion
- the space which is reserved in the qgroup is different with
the free space reservation. we need reserve free space for
7 items, but in qgroup reservation, we need reserve space only
for 3 items.
So we implement new metadata reservation functions for the
snapshot/subvolume creation.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Since we have grabbed the parent inode at the beginning of the
snapshot creation, and both sync and async snapshot creation
release it after the pending snapshots are actually created,
it is safe to access the parent inode directly during the snapshot
creation, we needn't use dget_parent/dput to fix the parent dentry
and get the dir inode.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
While doing cleanup work on an aborted transaction, we've set
the global running transaction pointer to NULL _before_ waiting all
other transaction handles to finish, so others'd hit NULL pointer
crash when referencing the global running transaction pointer.
This first sets a hint to avoid new transaction handle joining, then
waits other existing handles to abort or finish so that we can safely
set the above global pointer to NULL.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
While inserting dir index and updating inode for a snapshot, we'd
add delayed items which consume trans->block_rsv, if we don't have
any space reserved in this trans handle, we either just return or
reserve space again.
But before creating pending snapshots during committing transaction,
we've done a release on this trans handle, so we don't have space reserved
in it at this stage.
What we're using is block_rsv of pending snapshots which has already
reserved well enough space for both inserting dir index and updating
inode, so we need to set trans handle to indicate that we have space
now.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Pull trivial tree from Jiri Kosina:
"Assorted tiny fixes queued in trivial tree"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (22 commits)
DocBook: update EXPORT_SYMBOL entry to point at export.h
Documentation: update top level 00-INDEX file with new additions
ARM: at91/ide: remove unsused at91-ide Kconfig entry
percpu_counter.h: comment code for better readability
x86, efi: fix comment typo in head_32.S
IB: cxgb3: delay freeing mem untill entirely done with it
net: mvneta: remove unneeded version.h include
time: x86: report_lost_ticks doesn't exist any more
pcmcia: avoid static analysis complaint about use-after-free
fs/jfs: Fix typo in comment : 'how may' -> 'how many'
of: add missing documentation for of_platform_populate()
btrfs: remove unnecessary cur_trans set before goto loop in join_transaction
sound: soc: Fix typo in sound/codecs
treewide: Fix typo in various drivers
btrfs: fix comment typos
Update ibmvscsi module name in Kconfig.
powerpc: fix typo (utilties -> utilities)
of: fix spelling mistake in comment
h8300: Fix home page URL in h8300/README
xtensa: Fix home page URL in Kconfig
...
We forget to free qgroup reservation in commit_transaction(),fix it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Cc: Arne Jansen <sensille@gmx.net>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
In some cases, we need commit the current transaction, but don't want
to start a new one if there is no running transaction, so we introduce
the function - btrfs_attach_transaction(), which can catch the current
transaction, and return -ENOENT if there is no running transaction.
But no running transaction doesn't mean the current transction completely,
because we removed the running transaction before it completes. In some
cases, it doesn't matter. But in some special cases, such as freeze fs, we
hope the transaction is fully on disk, it will introduce some bugs, for
example, we may feeze the fs and dump the data in the disk, if the transction
doesn't complete, we would dump inconsistent data. So we need fix the above
problem for those cases.
We fixes this problem by introducing a function:
btrfs_attach_transaction_barrier()
if we hope all the transaction is fully on the disk, even they are not
running, we can use this function.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Now btrfs_commit_transaction() does this
ret = btrfs_run_ordered_operations(root, 0)
which async flushes all inodes on the ordered operations list, it introduced
a deadlock that transaction-start task, transaction-commit task and the flush
workers waited for each other.
(See the following URL to get the detail
http://marc.info/?l=linux-btrfs&m=136070705732646&w=2)
As we know, if ->in_commit is set, it means someone is committing the
current transaction, we should not try to join it if we are not JOIN
or JOIN_NOLOCK, wait is the best choice for it. In this way, we can avoid
the above problem. In this way, there is another benefit: there is no new
transaction handle to block the transaction which is on the way of commit,
once we set ->in_commit.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
In start_transactio(), we will try to join the transaction again after
the current transaction is committed, so we should not release the
reserved space of the qgroup. Fix it.
Cc: Arne Jansen <sensille@gmx.net>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Miao made the ordered operations stuff run async, which introduced a
deadlock where we could get somebody (sync) racing in and committing the
transaction while a commit was already happening. The new committer would
try and flush ordered operations which would hang waiting for the commit to
finish because it is done asynchronously and no longer inherits the callers
trans handle. To fix this we need to make the ordered operations list a per
transaction list. We can get new inodes added to the ordered operation list
by truncating them and then having another process writing to them, so this
makes it so that anybody trying to add an ordered operation _must_ start a
transaction in order to add itself to the list, which will keep new inodes
from getting added to the ordered operations list after we start committing.
This should fix the deadlock and also keeps us from doing a lot more work
than we need to during commit. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
The defrag operation can take very long, we want to have a way how to
cancel it. The code checks for a pending signal at safe points in the
defrag loops and returns EAGAIN. This means a user can press ^C after
running 'btrfs fi defrag', woks for both defrag modes, files and root.
Returning from the command was instant in my light tests, but may take
longer depending on the aging factor of the filesystem.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
The entry point at the defrag ioctl always sets "cache only" to 0;
the codepaths haven't run for a long time as far as I can
tell. Chris says they're dead code, so remove them.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
I hit a deadlock where transaction commit was waiting on num_writers to be
0. This happened because somebody came into btrfs_commit_transaction and
noticed we had aborted and it went to cleanup_transaction. This shouldn't
happen because cleanup_transaction is really to fixup a bad commit, it
doesn't do the normal trans handle cleanup things. So if we have an error
just do the normal btrfs_end_transaction dance and return. Once we are in
the actual commit path we can use cleanup_transaction and be good to go.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
There is no lock to protect fs_info->fs_state, it will introduce
some problems, such as the value may be covered by the other task
when several tasks modify it. For example:
Task0 - CPU0 Task1 - CPU1
mov %fs_state rax
or $0x1 rax
mov %fs_state rax
or $0x2 rax
mov rax %fs_state
mov rax %fs_state
The expected value is 3, but in fact, it is 2.
Though this problem doesn't happen now (because there is only one
flag currently), the code is error prone, if we add other flags,
the above problem will happen to a certainty.
Now we use bit operation for it to fix the above problem.
In this way, we can make the code more robust and be easy to
add new flags.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
We forget to check the return value of btrfs_run_ordered_operations() when
flushing all the pending stuffs, fix it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
We forget to check the return value of btrfs_start_delalloc_inodes(), fix it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
If we start running low on metadata space we will try to allocate a chunk,
which could then try to allocate a chunk to add the device entry. The thing
is we allocate a chunk before we try really hard to make the allocation, so
we should be able to find space for the device entry. Add a flag to the
trans handle so we know we're currently allocating a chunk so we can just
bail out if we try to allocate another chunk. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Since we do not want to delay the async transaction commit, we should
use common work, not delayed work.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
We clear the transaction object and the trans handle when they are about to be
freed, it is unnecessary, cleanup it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
When we fail to start a transaction, we need to release the reserved free space
and qgroup space, fix it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
We batch up operations to the extent allocation tree, which allows
us to deal with the recursive nature of using the extent allocation
tree to allocate extents to the extent allocation tree.
It also provides a mechanism to sort and collect extent
operations, which makes it much more efficient to record extents
that are close together.
The delayed extent operations must all be finished before the
running transaction commits, so we have code to make sure and run a few
of the batched operations when closing our transaction handles.
This creates a great deal of contention for the locks in the
delayed extent operation tree, and also contention for the lock on the
extent allocation tree itself. All the extra contention just slows
down the operations and doesn't get things done any faster.
This commit changes things to use a wait queue instead. As procs
want to run the delayed operations, one of them races in and gets
permission to hit the tree, and the others step back and wait for
progress to be made.
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
This builds on David Woodhouse's original Btrfs raid5/6 implementation.
The code has changed quite a bit, blame Chris Mason for any bugs.
Read/modify/write is done after the higher levels of the filesystem have
prepared a given bio. This means the higher layers are not responsible
for building full stripes, and they don't need to query for the topology
of the extents that may get allocated during delayed allocation runs.
It also means different files can easily share the same stripe.
But, it does expose us to incorrect parity if we crash or lose power
while doing a read/modify/write cycle. This will be addressed in a
later commit.
Scrub is unable to repair crc errors on raid5/6 chunks.
Discard does not work on raid5/6 (yet)
The stripe size is fixed at 64KiB per disk. This will be tunable
in a later commit.
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
First, though the current transaction->aborted check can stop the commit early
and avoid unnecessary operations, it is too early, and some transaction handles
don't end, those handles may set transaction->aborted after the check.
Second, when we commit the transaction, we will wake up some worker threads to
flush the space cache and inode cache. Those threads also allocate some transaction
handles and may set transaction->aborted if some serious error happens.
So we need more check for ->aborted when committing the transaction. Fix it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
We may access and update transaction->aborted on the different CPUs without
lock, so we need ACCESS_ONCE() wrapper to prevent the compiler from creating
unsolicited accesses and make sure we can get the right value.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
In the big loop, cur_trans will be set fs_info->running_transaction
before it's used. And after kmem_cache_free it and goto loop, it will
be setup again. No need to setup it immediately after freed.
Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The handling for directory crc hash overflows was fairly obscure,
split_leaf returns EOVERFLOW when we try to extend the item and that is
supposed to bubble up to userland. For a while it did so, but along the
way we added better handling of errors and forced the FS readonly if we
hit IO errors during the directory insertion.
Along the way, we started testing only for EEXIST and the EOVERFLOW case
was dropped. The end result is that we may force the FS readonly if we
catch a directory hash bucket overflow.
This fixes a few problem spots. First I add tests for EOVERFLOW in the
places where we can safely just return the error up the chain.
btrfs_rename is harder though, because it tries to insert the new
directory item only after it has already unlinked anything the rename
was going to overwrite. Rather than adding very complex logic, I added
a helper to test for the hash overflow case early while it is still safe
to bail out.
Snapshot and subvolume creation had a similar problem, so they are using
the new helper now too.
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Reported-by: Pascal Junod <pascal@junod.info>
If the id of the existed transaction is more than the one we specified, it
means the specified transaction was commited, so we should return 0, not
EINVAL.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
If there is no running transaction in the fs, we needn't start a new one when
we want to start sync.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
This commit contains all the essential changes to the core code
of Btrfs for support of the device replace procedure.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
- 'nr' is no more used.
- btrfs_btree_balance_dirty() and __btrfs_btree_balance_dirty() can share
a bunch of code.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Use WARN rather than printk followed by WARN_ON(1), for conciseness.
A simplified version of the semantic patch that makes this transformation
is as follows: (http://coccinelle.lip6.fr/)
// <smpl>
@@
expression list es;
@@
-printk(
+WARN(1,
es);
-WARN_ON(1);
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Consider the following case:
Task1 Task2
start_transaction
commit_transaction
check pending snapshots list and the
list is empty.
add pending snapshot into list
skip the delalloc flush
end_transaction
...
And then the problem that the snapshot is different with the source subvolume
happen.
This patch fixes the above problem by flush all pending stuffs when all the
other tasks end the transaction.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
If we flush inodes with pending delalloc in a transaction, we may join
the same transaction handler more than 2 times.
The reason is:
Task use_count of trans handle
commit_transaction 1
|-> btrfs_start_delalloc_inodes 1
|-> run_delalloc_nocow 1
|-> join_transaction 2
|-> cow_file_range 2
|-> join_transaction 3
In fact, cow_file_range needn't join the transaction again because the caller
have joined the transaction, so we fix this problem by this way.
Reported-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
The process of the ordered operations is similar to the delalloc inode flush, so
we handle them by flush workers.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
This patch introduce a new worker pool named "flush_workers", and if we
want to force all the inode with pending delalloc to the disks, we can
queue those inodes into the work queue of the worker pool, in this way,
those inodes will be flushed by multi-task.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
In some places(such as: evicting inode), we just can not flush the reserved
space of delalloc, flushing the delayed directory index and delayed inode
is OK, but we don't try to flush those things and just go back when there is
no enough space to be reserved. This patch fixes this problem.
We defined 3 types of the flush operations: NO_FLUSH, FLUSH_LIMIT and FLUSH_ALL.
If we can in the transaction, we should not flush anything, or the deadlock
would happen, so use NO_FLUSH. If we flushing the reserved space of delalloc
would cause deadlock, use FLUSH_LIMIT. In the other cases, FLUSH_ALL is used,
and we will flush all things.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
On a really full file system I was getting ENOSPC back from
btrfs_update_inode when trying to update the parent inode when creating a
snapshot. Just use the fallback method so we can update the inode and not
have to worry about having a delayed ref. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Everytime we write out dirty pages we search for an offset in the tree,
convert the bits in the state, and then when we wait we search for the
offset again and clear the bits. So for every dirty range in the io tree we
are doing 4 rb searches, which is suboptimal. With this patch we are only
doing 2 searches for every cycle (modulo weird things happening). Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
With the following debug patch:
static int btrfs_freeze(struct super_block *sb)
{
+ struct btrfs_fs_info *fs_info = btrfs_sb(sb);
+ struct btrfs_transaction *trans;
+
+ spin_lock(&fs_info->trans_lock);
+ trans = fs_info->running_transaction;
+ if (trans) {
+ printk("Transid %llu, use_count %d, num_writer %d\n",
+ trans->transid, atomic_read(&trans->use_count),
+ atomic_read(&trans->num_writers));
+ }
+ spin_unlock(&fs_info->trans_lock);
return 0;
}
I found there was a orphan transaction after the freeze operation was done.
It is because the transaction may not be committed when the transaction handle
end even though it is the last handle of the current transaction. This design
avoid committing the transaction frequently, but also introduce the above
problem.
So I add btrfs_attach_transaction() which can catch the current transaction
and commit it. If there is no transaction, it will return ENOENT, and do not
anything.
This function also can be used to instead of btrfs_join_transaction_freeze()
because it don't increase the writer counter and don't start a new transaction,
so it also can fix the deadlock between sync and freeze.
Besides that, it is used to instead of btrfs_join_transaction() in
transaction_kthread(), because if there is no transaction, the transaction
kthread needn't anything.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
This patch add a type field into the transaction handle structure,
in this way, we needn't implement various end-transaction functions
and can make the code more simple and readable.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
This patch fixes memory leak of the transaction handle which happened
when starting transaction failed on a freezed fs.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
The macro btrfs_abort_transaction() can get the line number of the code
where the problem happens, so we should invoke it in the place that the
error occurs, or we will lose the line number.
Reported-by: David Sterba <dave@jikos.cz>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
So we start our freeze, somebody comes in and does an fsync() on a file
where we have to commit a transaction for whatever reason, and we will
deadlock because the freeze is waiting on FS_FREEZE people to stop writing
to the file system, but the transaction is waiting for its free space inodes
to be written out, which are in turn waiting on sb_start_intwrite while
trying to write the file extents. To fix this we'll just skip the
sb_start_intwrite() if we TRANS_JOIN_NOLOCK since we're being waited on by a
transaction commit so we're safe wrt to freeze and this will keep us from
deadlocking. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
I screwed this up, there is a race between checking if there is a running
transaction and actually starting a transaction in sync where we could race
with a freezer and get ourselves into trouble. To fix this we need to make
a new join type to only do the try lock on the freeze stuff. If it fails
we'll return EPERM and just return from sync. This fixes a hang Liu Bo
reported when running xfstest 68 in a loop. Thanks,
Reported-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
So we have lots of places where we try to preallocate chunks in order to
make sure we have enough space as we make our allocations. This has
historically meant that we're constantly tweaking when we should allocate a
new chunk, and historically we have gotten this horribly wrong so we way
over allocate either metadata or data. To try and keep this from happening
we are going to make it so that the block group item insertion is done out
of band at the end of a transaction. This will allow us to create chunks
even if we are trying to make an allocation for the extent tree. With this
patch my enospc tests run faster (didn't expect this) and more efficiently
use the disk space (this is what I wanted). Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Sage reported the following lockdep backtrace
=====================================
[ BUG: bad unlock balance detected! ]
3.6.0-rc2-ceph-00171-gc7ed62d #1 Not tainted
-------------------------------------
btrfs-cleaner/7607 is trying to release lock (sb_internal) at:
[<ffffffffa00422ae>] btrfs_commit_transaction+0xa6e/0xb20 [btrfs]
but there are no more locks to release!
other info that might help us debug this:
1 lock held by btrfs-cleaner/7607:
#0: (&fs_info->cleaner_mutex){+.+...}, at: [<ffffffffa003b405>] cleaner_kthread+0x95/0x120 [btrfs]
stack backtrace:
Pid: 7607, comm: btrfs-cleaner Not tainted 3.6.0-rc2-ceph-00171-gc7ed62d #1
Call Trace:
[<ffffffffa00422ae>] ? btrfs_commit_transaction+0xa6e/0xb20 [btrfs]
[<ffffffff810afa9e>] print_unlock_inbalance_bug+0xfe/0x110
[<ffffffff810b289e>] lock_release_non_nested+0x1ee/0x310
[<ffffffff81172f9b>] ? kmem_cache_free+0x7b/0x160
[<ffffffffa004106c>] ? put_transaction+0x8c/0x130 [btrfs]
[<ffffffffa00422ae>] ? btrfs_commit_transaction+0xa6e/0xb20 [btrfs]
[<ffffffff810b2a95>] lock_release+0xd5/0x220
[<ffffffff81173071>] ? kmem_cache_free+0x151/0x160
[<ffffffff8117d9ed>] __sb_end_write+0x7d/0x90
[<ffffffffa00422ae>] btrfs_commit_transaction+0xa6e/0xb20 [btrfs]
[<ffffffff81079850>] ? __init_waitqueue_head+0x60/0x60
[<ffffffff81634c6b>] ? _raw_spin_unlock+0x2b/0x40
[<ffffffffa0042758>] __btrfs_end_transaction+0x368/0x3c0 [btrfs]
[<ffffffffa0042808>] btrfs_end_transaction_throttle+0x18/0x20 [btrfs]
[<ffffffffa00318f0>] btrfs_drop_snapshot+0x410/0x600 [btrfs]
[<ffffffff8132babd>] ? do_raw_spin_unlock+0x5d/0xb0
[<ffffffffa00430ef>] btrfs_clean_old_snapshots+0xaf/0x150 [btrfs]
[<ffffffffa003b405>] ? cleaner_kthread+0x95/0x120 [btrfs]
[<ffffffffa003b419>] cleaner_kthread+0xa9/0x120 [btrfs]
[<ffffffffa003b370>] ? btrfs_destroy_delayed_refs.isra.102+0x220/0x220 [btrfs]
[<ffffffff810791ee>] kthread+0xae/0xc0
[<ffffffff810b379d>] ? trace_hardirqs_on+0xd/0x10
[<ffffffff8163e744>] kernel_thread_helper+0x4/0x10
[<ffffffff81635430>] ? retint_restore_args+0x13/0x13
[<ffffffff81079140>] ? flush_kthread_work+0x1a0/0x1a0
[<ffffffff8163e740>] ? gs_change+0x13/0x13
This is because the throttle stuff can commit the transaction, which expects to
be the one stopping the intwrite stuff, but we've already done it in the
__btrfs_end_transaction. Moving the sb_end_intewrite after this logic makes the
lockdep go away. Thanks,
Tested-by: Sage Weil <sage@inktank.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
When we delete a inode, we will remove all the delayed items including delayed
inode update, and then truncate all the relative metadata. If there is lots of
metadata, we will end the current transaction, and start a new transaction to
truncate the left metadata. In this way, we will leave a inode item that its
link counter is > 0, and also may leave some directory index items in fs/file tree
after the current transaction ends. In other words, the metadata in this fs/file tree
is inconsistent. If we create a snapshot for this tree now, we will find a inode with
corrupted metadata in the new snapshot, and we won't continue to drop the left metadata,
because its link counter is not 0.
We fix this problem by updating the inode item before the current transaction ends.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
The snapshot should be the image of the fs tree before it was created,
so the metadata of the snapshot should not exist in the its tree. But now, we
found the directory item and directory name index is in both the snapshot tree
and the fs tree. It introduces some problems and makes the users feel strange:
# mkfs.btrfs /dev/sda1
# mount /dev/sda1 /mnt
# mkdir /mnt/1
# cd /mnt/1
# btrfs subvolume snapshot /mnt snap0
# ls -a /mnt/1/snap0/1
. .. [no other file/dir]
# ll /mnt/1/snap0/
total 0
drwxr-xr-x 1 root root 10 Ju1 24 12:11 1
^^^
There is no file/dir in it, but it's size is 10
# cd /mnt/1/snap0/1/snap0
[Enter a unexisted directory successfully...]
There is nothing in the directory 1 in snap0, but btrfs told the length of
this directory is 10. Beside that, we can enter an unexisted directory, it is
very strange to the users.
# btrfs subvolume snapshot /mnt/1/snap0 /mnt/snap1
# ll /mnt/1/snap0/1/
total 0
[None]
# ll /mnt/snap1/1/
total 0
drwxr-xr-x 1 root root 0 Ju1 24 12:14 snap0
And the source of snap1 did have any directory in Directory 1, but snap1 have
a snap0, it is different between the source and the snapshot.
So I think we should insert directory item and directory name index and update
the parent inode as the last step of snapshot creation, and do not leave the
useless metadata in the file tree.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
If we create several snapshots at the same time, the following BUG_ON() will be
triggered.
kernel BUG at fs/btrfs/extent-tree.c:6047!
Steps to reproduce:
# mkfs.btrfs <partition>
# mount <partition> <mnt>
# cd <mnt>
# for ((i=0;i<2400;i++)); do touch long_name_to_make_tree_more_deep$i; done
# for ((i=0; i<4; i++))
> do
> mkdir $i
> for ((j=0; j<200; j++))
> do
> btrfs sub snap . $i/$j
> done &
> done
The reason is:
Before transaction commit, some operations changed the fs tree and new tree
blocks were allocated because of COW. We used the implicit non-shared back
reference for those newly allocated tree blocks because they were not shared by
two or more trees.
And then we created the first snapshot for the fs tree, according to the back
reference rules, we also used implicit back refs for the child tree blocks of
the root node of the fs tree, now those child nodes/leaves were shared by two
trees.
Then We didn't deal with the delayed references, and continued to change the fs
tree(created the second snapshot and inserted the dir item of the new snapshot
into the fs tree). According to the rules of the back reference, we added full
back refs for those tree blocks whose parents have be shared by two trees.
Now some newly allocated tree blocks had two types of the references.
As we know, the delayed reference system handles these delayed references from
back to front, and the full delayed reference is inserted after the implicit
ones. So when we dealt with the back references of those newly allocated tree
blocks, the full references was dealt with at first. And if the first reference
is a shared back reference and the tree block that the reference points to is
newly allocated, It would be considered as a tree block which is shared by two
or more trees when it is allocated and should be a full back reference not a
implicit one, the flag of its reference also should be set to FULL_BACKREF.
But in fact, it was a non-shared tree block with a implicit reference at
beginning, so it was not compulsory to set the flags to FULL_BACKREF. So BUG_ON
was triggered.
We have several methods to fix this bug:
1. deal with delayed references after the snapshot is created and before we
change the source tree of the snapshot. This is the easiest and safest way.
2. modify the sort method of the delayed reference tree, make the full delayed
references be inserted before the implicit ones. It is also very easy, but
I don't know if it will introduce some problems or not.
3. modify select_delayed_ref() and make it select the implicit delayed reference
at first. This way is not so good because it may wastes CPU time if we have
lots of delayed references.
4. set the flags to FULL_BACKREF, this method is a little complex comparing with
the 1st way.
I chose the 1st way to fix it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
This patch fixes the following problem:
- If we failed to deal with the delayed dir items, we should abort transaction,
just as its comment said. Fix it.
- If root reference or root back reference insertion failed, we should
abort transaction. Fix it.
- Fix the double free problem of pending->inherit.
- Do not restore the trans->rsv if we doesn't change it.
- make the error path more clearly.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
The freeze rwsem is taken by sb_start_intwrite() and dropped during the
commit_ or end_transaction(). In the async case, that happens in a worker
thread. Tell lockdep the calling thread is releasing ownership of the
rwsem and the async thread is picking it up.
XFS plays the same trick in fs/xfs/xfs_aops.c.
Signed-off-by: Sage Weil <sage@inktank.com>
Pull btrfs fixes from Chris Mason:
"I've split out the big send/receive update from my last pull request
and now have just the fixes in my for-linus branch. The send/recv
branch will wander over to linux-next shortly though.
The largest patches in this pull are Josef's patches to fix DIO
locking problems and his patch to fix a crash during balance. They
are both well tested.
The rest are smaller fixes that we've had queued. The last rc came
out while I was hacking new and exciting ways to recover from a
misplaced rm -rf on my dev box, so these missed rc3."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (25 commits)
Btrfs: fix that repair code is spuriously executed for transid failures
Btrfs: fix ordered extent leak when failing to start a transaction
Btrfs: fix a dio write regression
Btrfs: fix deadlock with freeze and sync V2
Btrfs: revert checksum error statistic which can cause a BUG()
Btrfs: remove superblock writing after fatal error
Btrfs: allow delayed refs to be merged
Btrfs: fix enospc problems when deleting a subvol
Btrfs: fix wrong mtime and ctime when creating snapshots
Btrfs: fix race in run_clustered_refs
Btrfs: don't run __tree_mod_log_free_eb on leaves
Btrfs: increase the size of the free space cache
Btrfs: barrier before waitqueue_active
Btrfs: fix deadlock in wait_for_more_refs
btrfs: fix second lock in btrfs_delete_delayed_items()
Btrfs: don't allocate a seperate csums array for direct reads
Btrfs: do not strdup non existent strings
Btrfs: do not use missing devices when showing devname
Btrfs: fix that error value is changed by mistake
Btrfs: lock extents as we map them in DIO
...
When we created a new snapshot, the mtime and ctime of its parent directory
were not updated. Fix it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
"trans->transid" is cpu endian but we want to store the data as little
endian. "item->ctime.nsec" is only 32 bits, not 64.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Pull second vfs pile from Al Viro:
"The stuff in there: fsfreeze deadlock fixes by Jan (essentially, the
deadlock reproduced by xfstests 068), symlink and hardlink restriction
patches, plus assorted cleanups and fixes.
Note that another fsfreeze deadlock (emergency thaw one) is *not*
dealt with - the series by Fernando conflicts a lot with Jan's, breaks
userland ABI (FIFREEZE semantics gets changed) and trades the deadlock
for massive vfsmount leak; this is going to be handled next cycle.
There probably will be another pull request, but that stuff won't be
in it."
Fix up trivial conflicts due to unrelated changes next to each other in
drivers/{staging/gdm72xx/usb_boot.c, usb/gadget/storage_common.c}
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits)
delousing target_core_file a bit
Documentation: Correct s_umount state for freeze_fs/unfreeze_fs
fs: Remove old freezing mechanism
ext2: Implement freezing
btrfs: Convert to new freezing mechanism
nilfs2: Convert to new freezing mechanism
ntfs: Convert to new freezing mechanism
fuse: Convert to new freezing mechanism
gfs2: Convert to new freezing mechanism
ocfs2: Convert to new freezing mechanism
xfs: Convert to new freezing code
ext4: Convert to new freezing mechanism
fs: Protect write paths by sb_start_write - sb_end_write
fs: Skip atime update on frozen filesystem
fs: Add freezing handling to mnt_want_write() / mnt_drop_write()
fs: Improve filesystem freezing handling
switch the protection of percpu_counter list to spinlock
nfsd: Push mnt_want_write() outside of i_mutex
btrfs: Push mnt_want_write() outside of i_mutex
fat: Push mnt_want_write() outside of i_mutex
...
We convert btrfs_file_aio_write() to use new freeze check. We also add proper
freeze protection to btrfs_page_mkwrite(). We also add freeze protection to
the transaction mechanism to avoid starting transactions on frozen filesystem.
At minimum this is necessary to stop iput() of unlinked file to change frozen
filesystem during truncation.
Checks in cleaner_kthread() and transaction_kthread() can be safely removed
since btrfs_freeze() will lock the mutexes and thus block the threads (and they
shouldn't have anything to do anyway).
CC: linux-btrfs@vger.kernel.org
CC: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This is the kernel portion of btrfs send/receive
Conflicts:
fs/btrfs/Makefile
fs/btrfs/backref.h
fs/btrfs/ctree.c
fs/btrfs/ioctl.c
fs/btrfs/ioctl.h
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
This patch introduces uuids for subvolumes. Each
subvolume has it's own uuid. In case it was snapshotted,
it also contains parent_uuid. In case it was received,
it also contains received_uuid.
It also introduces subvolume ctime/otime/stime/rtime. The
first two are comparable to the times found in inodes. otime
is the origin/creation time and ctime is the change time.
stime/rtime are only valid on received subvolumes.
stime is the time of the subvolume when it was
sent. rtime is the time of the subvolume when it was
received.
Additionally to the times, we have a transid for each
time. They are updated at the same place as the times.
btrfs receive uses stransid and rtransid to find out
if a received subvolume changed in the meantime.
If an older kernel mounts a filesystem with the
extented fields, all fields become invalid. The next
mount with a new kernel will detect this and reset the
fields.
Signed-off-by: Alexander Block <ablock84@googlemail.com>
Reviewed-by: David Sterba <dave@jikos.cz>
Reviewed-by: Arne Jansen <sensille@gmx.net>
Reviewed-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Reviewed-by: Alex Lyakas <alex.bolshoy.btrfs@gmail.com>
There is weird logic I had to put in place to make sure that when we were
adding csums that we'd used the delalloc block rsv instead of the global
block rsv. Part of this meant that we had to free up our transaction
reservation before we ran the delayed refs since csum deletion happens
during the delayed ref work. The problem with this is that when we release
a reservation we will add it to the global reserve if it is not full in
order to keep us going along longer before we have to force a transaction
commit. By releasing our reservation before we run delayed refs we don't
get the opportunity to drain down the global reserve for the work we did, so
we won't refill it as often. This isn't a problem per-se, it just results
in us possibly committing transactions more and more often, and in rare
cases could cause those WARN_ON()'s to pop in use_block_rsv because we ran
out of space in our block rsv.
This also helps us by holding onto space while the delayed refs run so we
don't end up with as many people trying to do things at the same time, which
again will help us not force commits or hit the use_block_rsv warnings.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
"root->fs_info" and "fs_info" are the same, but "fs_info" is prefered
because it is shorter and that's what is used in the rest of the
function.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Waiting on spindles improves performance, but ssds want all the
IO as quickly as we can push it down.
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
When creating a subvolume or snapshot, it is necessary
to initialize the qgroup account with a copy of some
other (tracking) qgroup. This patch adds parameters
to the ioctls to pass the information from which qgroup
to inherit.
Signed-off-by: Arne Jansen <sensille@gmx.net>
Like block reserves, reserve a small piece of space on each
transaction start and for delalloc. These are the hooks that
can actually return EDQUOT to the user.
The amount of space reserved is tracked in the transaction
handle.
Signed-off-by: Arne Jansen <sensille@gmx.net>
Hooks into qgroup code to record refs and into transaction commit.
This is the main entry point for qgroup. Basically every change in
extent backrefs got accounted to the appropriate qgroups.
Signed-off-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
This patch only add a consistancy check to validate that the
same root is passed to start_transaction and end_transaction.
Subvolume quota depends on this.
Signed-off-by: Arne Jansen <sensille@gmx.net>
We've got two mechanisms both required for reliable backref resolving (tree
mod log and holding back delayed refs). You cannot make use of one without
the other. So instead of requiring the user of this mechanism to setup both
correctly, we join them into a single interface.
Additionally, we stop inserting non-blockers into fs_info->tree_mod_seq_list
as we did before, which was of no value.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
If a transaction commit fails we don't abort it so we don't set an error on
the file system. This patch fixes that by actually calling the abort stuff
and then adding a check for a fs error in the transaction start stuff to
make sure it is caught properly. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
I was getting lots of hung tasks and a NULL pointer dereference because we
are not cleaning up the transaction properly when it aborts. First we need
to reset the running_transaction to NULL so we don't get a bad dereference
for any start_transaction callers after this. Also we cannot rely on
waitqueue_active() since it's just a list_empty(), so just call wake_up()
directly since that will do the barrier for us and such. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
The device statistics are written into the device tree with each
transaction commit. Only modified statistics are written.
When a filesystem is mounted, the device statistics for each involved
device are read from the device tree and used to initialize the
counters.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
