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>
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>
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>
