We're holding the sb_start_intwrite lock at this point, and doing async
filemap_flush of the inodes will result in a deadlock if we freeze the
fs during this operation. This is because we could do a
btrfs_join_transaction() in the thread we are waiting on which would
block at sb_start_intwrite, and thus deadlock. Using
writeback_inodes_sb() side steps the problem by not introducing all of
these extra locking dependencies.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We were only doing btrfs_check_space_for_delayed_refs() if the metadata
space was full, ie we couldn't allocate chunks. This assumes we'll be
able to allocate chunks during transaction commit, but since nothing
does a LIMIT flush during the transaction commit this won't actually
happen unless we happen to run shy of actual space. We already take
into account a full fs in btrfs_check_space_for_delayed_refs() so just
kill this extra check to make sure we're ending the transaction when we
need to.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We have started plug in btrfs_write_and_wait_marked_extents() but the
generated IOs actually go to device's schedule IO list where the work
is doing in another task, thus the started plug doesn't make any
sense.
And since we wait for IOs immediately after writing meta blocks, it's
the same case as writing log tree, doing sync submit can merge more
IOs.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Dave Jones hit a WARN_ON(nr < 0) in btrfs_wait_ordered_roots() with
v4.12-rc6. This was because commit 70e7af244 made it possible for
calc_reclaim_items_nr() to return a negative number. It's not really a
bug in that commit, it just didn't go far enough down the stack to find
all the possible 64->32 bit overflows.
This switches calc_reclaim_items_nr() to return a u64 and changes everyone
that uses the results of that math to u64 as well.
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Fixes: 70e7af2 ("Btrfs: fix delalloc accounting leak caused by u32 overflow")
Signed-off-by: Chris Mason <clm@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Quite a lot of qgroup corruption happens due to wrong time of calling
btrfs_qgroup_prepare_account_extents().
Since the safest time is to call it just before
btrfs_qgroup_account_extents(), there is no need to separate these 2
functions.
Merging them will make code cleaner and less bug prone.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
[ changelog and comment adjustments ]
Signed-off-by: David Sterba <dsterba@suse.com>
We can keep the state among the other fs_info flags, there's no reason
why fs_frozen would need to be separate.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Observing the number of slab objects of btrfs_transaction, there's just
one active on an almost quiescent filesystem, and the number of objects
goes to about ten when sync is in progress. Then the nubmer goes down to
1. This matches the expectations of the transaction lifetime.
For such use the separate slab cache is not justified, as we do not
reuse objects frequently. For the shortlived transaction, the generic
slab (size 512) should be ok. We can optimistically expect that the 512
slabs are not all used (fragmentation) and there are free slots to take
when we do the allocation, compared to potentially allocating a whole new
page for the separate slab.
We'll lose the stats about the object use, which could be added later if
we really need them.
Signed-off-by: David Sterba <dsterba@suse.com>
For extent_io tree's we have carried the address_mapping of the inode
around in the io tree in order to pull the inode back out for calling
into various tree ops hooks. This works fine when everything that has
an extent_io_tree has an inode. But we are going to remove the
btree_inode, so we need to change this. Instead just have a generic
void * for private data that we can initialize with, and have all the
tree ops use that instead. This had a lot of cascading changes but
should be relatively straightforward.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor reordering of the callback prototypes ]
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
The easist way to reproduce the bug is:
------
# mkfs.btrfs -f $dev -n 16K
# mount $dev $mnt -o inode_cache
# btrfs quota enable $mnt
# btrfs quota rescan -w $mnt
# btrfs qgroup show $mnt
qgroupid rfer excl
-------- ---- ----
0/5 32.00KiB 32.00KiB
^^ Twice the correct value
------
And fstests/btrfs qgroup test group can easily detect them with
inode_cache mount option.
Although some of them are false alerts since old test cases are using
fixed golden output.
While new test cases will use "btrfs check" to detect qgroup mismatch.
[CAUSE]
Inode_cache mount option will make commit_fs_roots() to call
btrfs_save_ino_cache() to update fs/subvol trees, and generate new
delayed refs.
However we call btrfs_qgroup_prepare_account_extents() too early, before
commit_fs_roots().
This makes the "old_roots" for newly generated extents are always NULL.
For freeing extent case, this makes both new_roots and old_roots to be
empty, while correct old_roots should not be empty.
This causing qgroup numbers not decreased correctly.
[FIX]
Modify the timing of calling btrfs_qgroup_prepare_account_extents() to
just before btrfs_qgroup_account_extents(), and add needed delayed_refs
handler.
So qgroup can handle inode_map mount options correctly.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The members have been effectively unused since "Btrfs: rework qgroup
accounting" (fcebe4562d), there's no substitute for
assert_qgroups_uptodate so it's removed as well.
Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
write_all_supers and write_ctree_super are almost equal, the parameter
'trans' is unused so we can drop it and have just one helper.
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The quota status used to be tracked as a variable, so the mutex was
needed (until "Btrfs: add a flags field to btrfs_fs_info" afcdd129e0).
Since the status is a bit modified atomically and we don't hold the
mutex beyond the check, we can drop it.
Signed-off-by: David Sterba <dsterba@suse.com>
Once a qgroup limit is exceeded, it's impossible to restore normal
operation to the subvolume without modifying the limit or removing
the subvolume. This is a surprising situation for many users used
to the typical workflow with quotas on other file systems where it's
possible to remove files until the used space is back under the limit.
When we go to unlink a file and start the transaction, we'll hit
the qgroup limit while trying to reserve space for the items we'll
modify while removing the file. We discussed last month how best
to handle this situation and agreed that there is no perfect solution.
The best principle-of-least-surprise solution is to handle it similarly
to how we already handle ENOSPC when unlinking, which is to allow
the operation to succeed with the expectation that it will ultimately
release space under most circumstances.
This patch modifies the transaction start path to select whether to
honor the qgroups limits. btrfs_start_transaction_fallback_global_rsv
is the only caller that skips enforcement. The reservation and tracking
still happens normally -- it just skips the enforcement step.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently btrfs_ino takes a struct inode and this causes a lot of
internal btrfs functions which consume this ino to take a VFS inode,
rather than btrfs' own struct btrfs_inode. In order to fix this "leak"
of VFS structs into the internals of btrfs first it's necessary to
eliminate all uses of struct inode for the purpose of inode. This patch
does that by using BTRFS_I to convert an inode to btrfs_inode. With
this problem eliminated subsequent patches will start eliminating the
passing of struct inode altogether, eventually resulting in a lot cleaner
code.
Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com>
[ fix btrfs_get_extent tracepoint prototype ]
Signed-off-by: David Sterba <dsterba@suse.com>
This replaces ACCESS_ONCE macro with the corresponding
READ|WRITE macros
Signed-off-by: Seraphime Kirkovski <kirkseraph@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Now we only use the root parameter to print the root objectid in
a tracepoint. We can use the root parameter from the transaction
handle for that. It's also used to join the transaction with
async commits, so we remove the comment that it's just for checking.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_write_and_wait_marked_extents and btrfs_sync_log both call
btrfs_wait_marked_extents, which provides a core loop and then handles
errors differently based on whether it's it's a log root or not.
This means that btrfs_write_and_wait_marked_extents needs to take a root
because btrfs_wait_marked_extents requires one, even though it's only
used to determine whether the root is a log root. The log root code
won't ever call into the transaction commit code using a log root, so we
can factor out the core loop and provide the error handling appropriate
to each waiter in new routines. This allows us to eventually remove
the root argument from btrfs_commit_transaction, and as a result,
btrfs_end_transaction.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are loads of functions in btrfs that accept a root parameter
but only use it to obtain an fs_info pointer. Let's convert those to
just accept an fs_info pointer directly.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This results in btrfs_assert_delayed_root_empty and
btrfs_destroy_delayed_inode taking an fs_info instead of a root.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In routines where someptr->fs_info is referenced multiple times, we
introduce a convenience variable. This makes the code considerably
more readable.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We track the node sizes per-root, but they never vary from the values
in the superblock. This patch messes with the 80-column style a bit,
but subsequent patches to factor out root->fs_info into a convenience
variable fix it up again.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are many functions that are always called with the same root
argument. Rather than passing the same root every time, we can
pass an fs_info pointer instead and have the function get the root
pointer itself.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are 11 functions that accept a root parameter and immediately
overwrite it. We can pass those an fs_info pointer instead.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Pull btrfs updates from Chris Mason:
"This is a big variety of fixes and cleanups.
Liu Bo continues to fixup fuzzer related problems, and some of Josef's
cleanups are prep for his bigger extent buffer changes (slated for
v4.10)"
* 'for-linus-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (39 commits)
Revert "btrfs: let btrfs_delete_unused_bgs() to clean relocated bgs"
Btrfs: remove unnecessary btrfs_mark_buffer_dirty in split_leaf
Btrfs: don't BUG() during drop snapshot
btrfs: fix btrfs_no_printk stub helper
Btrfs: memset to avoid stale content in btree leaf
btrfs: parent_start initialization cleanup
btrfs: Remove already completed TODO comment
btrfs: Do not reassign count in btrfs_run_delayed_refs
btrfs: fix a possible umount deadlock
Btrfs: fix memory leak in do_walk_down
btrfs: btrfs_debug should consume fs_info when DEBUG is not defined
btrfs: convert send's verbose_printk to btrfs_debug
btrfs: convert pr_* to btrfs_* where possible
btrfs: convert printk(KERN_* to use pr_* calls
btrfs: unsplit printed strings
btrfs: clean the old superblocks before freeing the device
Btrfs: kill BUG_ON in run_delayed_tree_ref
Btrfs: don't leak reloc root nodes on error
btrfs: squash lines for simple wrapper functions
Btrfs: improve check_node to avoid reading corrupted nodes
...
current_fs_time() uses struct super_block* as an argument.
As per Linus's suggestion, this is changed to take struct
inode* as a parameter instead. This is because the function
is primarily meant for vfs inode timestamps.
Also the function was renamed as per Arnd's suggestion.
Change all calls to current_fs_time() to use the new
current_time() function instead. current_fs_time() will be
deleted.
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
For many printks, we want to know which file system issued the message.
This patch converts most pr_* calls to use the btrfs_* versions instead.
In some cases, this means adding plumbing to allow call sites access to
an fs_info pointer.
fs/btrfs/check-integrity.c is left alone for another day.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This patch converts printk(KERN_* style messages to use the pr_* versions.
One side effect is that anything that was KERN_DEBUG is now automatically
a dynamic debug message.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
CodingStyle chapter 2:
"[...] never break user-visible strings such as printk messages,
because that breaks the ability to grep for them."
This patch unsplits user-visible strings.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since we could get errors from the concurrent aborted transaction,
the check of this BUG_ON in start_transaction is not true any more.
Say, while flushing free space cache inode's dirty pages,
btrfs_finish_ordered_io
-> btrfs_join_transaction_nolock
(the transaction has been aborted.)
-> BUG_ON(type == TRANS_JOIN_NOLOCK);
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We have a lot of random ints in btrfs_fs_info that can be put into flags. This
is mostly equivalent with the exception of how we deal with quota going on or
off, now instead we set a flag when we are turning it on or off and deal with
that appropriately, rather than just having a pending state that the current
quota_enabled gets set to. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When running fstests generic/068, sometimes we got below deadlock:
xfs_io D ffff8800331dbb20 0 6697 6693 0x00000080
ffff8800331dbb20 ffff88007acfc140 ffff880034d895c0 ffff8800331dc000
ffff880032d243e8 fffffffeffffffff ffff880032d24400 0000000000000001
ffff8800331dbb38 ffffffff816a9045 ffff880034d895c0 ffff8800331dbba8
Call Trace:
[<ffffffff816a9045>] schedule+0x35/0x80
[<ffffffff816abab2>] rwsem_down_read_failed+0xf2/0x140
[<ffffffff8118f5e1>] ? __filemap_fdatawrite_range+0xd1/0x100
[<ffffffff8134f978>] call_rwsem_down_read_failed+0x18/0x30
[<ffffffffa06631fc>] ? btrfs_alloc_block_rsv+0x2c/0xb0 [btrfs]
[<ffffffff810d32b5>] percpu_down_read+0x35/0x50
[<ffffffff81217dfc>] __sb_start_write+0x2c/0x40
[<ffffffffa067f5d5>] start_transaction+0x2a5/0x4d0 [btrfs]
[<ffffffffa067f857>] btrfs_join_transaction+0x17/0x20 [btrfs]
[<ffffffffa068ba34>] btrfs_evict_inode+0x3c4/0x5d0 [btrfs]
[<ffffffff81230a1a>] evict+0xba/0x1a0
[<ffffffff812316b6>] iput+0x196/0x200
[<ffffffffa06851d0>] btrfs_run_delayed_iputs+0x70/0xc0 [btrfs]
[<ffffffffa067f1d8>] btrfs_commit_transaction+0x928/0xa80 [btrfs]
[<ffffffffa0646df0>] btrfs_freeze+0x30/0x40 [btrfs]
[<ffffffff81218040>] freeze_super+0xf0/0x190
[<ffffffff81229275>] do_vfs_ioctl+0x4a5/0x5c0
[<ffffffff81003176>] ? do_audit_syscall_entry+0x66/0x70
[<ffffffff810038cf>] ? syscall_trace_enter_phase1+0x11f/0x140
[<ffffffff81229409>] SyS_ioctl+0x79/0x90
[<ffffffff81003c12>] do_syscall_64+0x62/0x110
[<ffffffff816acbe1>] entry_SYSCALL64_slow_path+0x25/0x25
>From this warning, freeze_super() already holds SB_FREEZE_FS, but
btrfs_freeze() will call btrfs_commit_transaction() again, if
btrfs_commit_transaction() finds that it has delayed iputs to handle,
it'll start_transaction(), which will try to get SB_FREEZE_FS lock
again, then deadlock occurs.
The root cause is that in btrfs, sync_filesystem(sb) does not make
sure all metadata is updated. There still maybe some codes adding
delayed iputs, see below sample race window:
CPU1 | CPU2
|-> freeze_super() |
|-> sync_filesystem(sb); |
| |-> cleaner_kthread()
| | |-> btrfs_delete_unused_bgs()
| | |-> btrfs_remove_chunk()
| | |-> btrfs_remove_block_group()
| | |-> btrfs_add_delayed_iput()
| |
|-> sb->s_writers.frozen = SB_FREEZE_FS; |
|-> sb_wait_write(sb, SB_FREEZE_FS); |
| acquire SB_FREEZE_FS lock. |
| |
|-> btrfs_freeze() |
|-> btrfs_commit_transaction() |
|-> btrfs_run_delayed_iputs() |
| will handle delayed iputs, |
| that means start_transaction() |
| will be called, which will try |
| to get SB_FREEZE_FS lock. |
To fix this issue, introduce a "int fs_frozen" to record internally whether
fs has been frozen. If fs has been frozen, we can not handle delayed iputs.
Signed-off-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add comment to btrfs_freeze ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
__btrfs_abort_transaction doesn't use its root parameter except to
obtain an fs_info pointer. We can obtain that from trans->root->fs_info
for now and from trans->fs_info in a later patch.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_trans_handle->root is documented as for use for confirming
that the root passed in to start the transaction is the same as the
one ending it. It's used in several places when an fs_info pointer
is needed, so let's just add an fs_info pointer directly. Eventually,
the root pointer can be removed.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_test_opt and friends only use the root pointer to access
the fs_info. Let's pass the fs_info directly in preparation to
eliminate similar patterns all over btrfs.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Using the offwakecputime bpf script I noticed most of our time was spent waiting
on the delayed ref throttling. This is what is supposed to happen, but
sometimes the transaction can commit and then we're waiting for throttling that
doesn't matter anymore. So change this stuff to be a little smarter by tracking
the transid we were in when we initiated the throttling. If the transaction we
get is different then we can just bail out. This resulted in a 50% speedup in
my fs_mark test, and reduced the amount of time spent throttling by 60 seconds
over the entire run (which is about 30 minutes). Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Introduced in 2c1984f244 ("btrfs: build fixup for
qgroup_account_snapshot") as temporary bisectability build fixup.
Signed-off-by: David Sterba <dsterba@suse.com>
Before the relocation process of a block group starts, it sets the block
group to readonly mode, then flushes all delalloc writes and then finally
it waits for all ordered extents to complete. This last step includes
waiting for ordered extents destinated at extents allocated in other block
groups, making us waste unecessary time.
So improve this by waiting only for ordered extents that fall into the
block group's range.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
The macro btrfs_std_error got renamed to btrfs_handle_fs_error in an
independent branch for the same merge target (4.7). To make the code
compilable for bisectability reasons, add a temporary stub.
Signed-off-by: David Sterba <dsterba@suse.com>
Current btrfs qgroup design implies a requirement that after calling
btrfs_qgroup_account_extents() there must be a commit root switch.
Normally this is OK, as btrfs_qgroup_accounting_extents() is only called
inside btrfs_commit_transaction() just be commit_cowonly_roots().
However there is a exception at create_pending_snapshot(), which will
call btrfs_qgroup_account_extents() but no any commit root switch.
In case of creating a snapshot whose parent root is itself (create a
snapshot of fs tree), it will corrupt qgroup by the following trace:
(skipped unrelated data)
======
btrfs_qgroup_account_extent: bytenr = 29786112, num_bytes = 16384, nr_old_roots = 0, nr_new_roots = 1
qgroup_update_counters: qgid = 5, cur_old_count = 0, cur_new_count = 1, rfer = 0, excl = 0
qgroup_update_counters: qgid = 5, cur_old_count = 0, cur_new_count = 1, rfer = 16384, excl = 16384
btrfs_qgroup_account_extent: bytenr = 29786112, num_bytes = 16384, nr_old_roots = 0, nr_new_roots = 0
======
The problem here is in first qgroup_account_extent(), the
nr_new_roots of the extent is 1, which means its reference got
increased, and qgroup increased its rfer and excl.
But at second qgroup_account_extent(), its reference got decreased, but
between these two qgroup_account_extent(), there is no switch roots.
This leads to the same nr_old_roots, and this extent just got ignored by
qgroup, which means this extent is wrongly accounted.
Fix it by call commit_cowonly_roots() after qgroup_account_extent() in
create_pending_snapshot(), with needed preparation.
Mark: I added a check at the top of qgroup_account_snapshot() to skip this
code if qgroups are turned off. xfstest btrfs/122 exposes this problem.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
Single caller passes GFP_NOFS. We can get rid of the
gfpflags_allow_blocking checks as NOFS can block but does not recurse to
filesystem through reclaim.
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_std_error() handles errors, puts FS into readonly mode
(as of now). So its good idea to rename it to btrfs_handle_fs_error().
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ edit changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
CURRENT_TIME macro is not appropriate for filesystems as it
doesn't use the right granularity for filesystem timestamps.
Use current_fs_time() instead.
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: linux-btrfs@vger.kernel.org
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are a few places where we add to trans->bytes_reserved but don't have the
corresponding trace point. With these added my tool no longer sees transaction
leaks.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We can also preallocate btrfs_path that's used during pending snapshot
creation and avoid another late ENOMEM failure.
Signed-off-by: David Sterba <dsterba@suse.com>
The actual snapshot creation is delayed until transaction commit. If we
cannot get enough memory for the root item there, we have to fail the
whole transaction commit which is bad. So we'll allocate the memory at
the ioctl call and pass it along with the pending_snapshot struct. The
potential ENOMEM will be returned to the caller of snapshot ioctl.
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When a transaction is aborted, or its commit fails before writing the new
superblock and calling btrfs_finish_extent_commit(), we leak reference
counts on the block groups attached to the transaction's delete_bgs list,
because btrfs_finish_extent_commit() is never called for those two cases.
Fix this by dropping their references at btrfs_put_transaction(), which
is called when transactions are aborted (by making the transaction kthread
commit the transaction) or if their commits fail.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
As of my previous change titled "Btrfs: fix scrub preventing unused block
groups from being deleted", the following warning at
extent-tree.c:btrfs_delete_unused_bgs() can be hit when we mount the a
filesysten with "-o discard":
10263 void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
10264 {
(...)
10405 if (trimming) {
10406 WARN_ON(!list_empty(&block_group->bg_list));
10407 spin_lock(&trans->transaction->deleted_bgs_lock);
10408 list_move(&block_group->bg_list,
10409 &trans->transaction->deleted_bgs);
10410 spin_unlock(&trans->transaction->deleted_bgs_lock);
10411 btrfs_get_block_group(block_group);
10412 }
(...)
This happens because scrub can now add back the block group to the list of
unused block groups (fs_info->unused_bgs). This is dangerous because we
are moving the block group from the unused block groups list to the list
of deleted block groups without holding the lock that protects the source
list (fs_info->unused_bgs_lock).
The following diagram illustrates how this happens:
CPU 1 CPU 2
cleaner_kthread()
btrfs_delete_unused_bgs()
sees bg X in list
fs_info->unused_bgs
deletes bg X from list
fs_info->unused_bgs
scrub_enumerate_chunks()
searches device tree using
its commit root
finds device extent for
block group X
gets block group X from the tree
fs_info->block_group_cache_tree
(via btrfs_lookup_block_group())
sets bg X to RO (again)
scrub_chunk(bg X)
sets bg X back to RW mode
adds bg X to the list
fs_info->unused_bgs again,
since it's still unused and
currently not in that list
sets bg X to RO mode
btrfs_remove_chunk(bg X)
--> discard is enabled and bg X
is in the fs_info->unused_bgs
list again so the warning is
triggered
--> we move it from that list into
the transaction's delete_bgs
list, but we can have another
task currently manipulating
the first list (fs_info->unused_bgs)
Fix this by using the same lock (fs_info->unused_bgs_lock) to protect both
the list of unused block groups and the list of deleted block groups. This
makes it safe and there's not much worry for more lock contention, as this
lock is seldom used and only the cleaner kthread adds elements to the list
of deleted block groups. The warning goes away too, as this was previously
an impossible case (and would have been better a BUG_ON/ASSERT) but it's
not impossible anymore.
Reproduced with fstest btrfs/073 (using MOUNT_OPTIONS="-o discard").
Signed-off-by: Filipe Manana <fdmanana@suse.com>
It's possible to reach a state where the cleaner kthread isn't able to
start a transaction to delete an unused block group due to lack of enough
free metadata space and due to lack of unallocated device space to allocate
a new metadata block group as well. If this happens try to use space from
the global block group reserve just like we do for unlink operations, so
that we don't reach a permanent state where starting a transaction for
filesystem operations (file creation, renames, etc) keeps failing with
-ENOSPC. Such an unfortunate state was observed on a machine where over
a dozen unused data block groups existed and the cleaner kthread was
failing to delete them due to ENOSPC error when attempting to start a
transaction, and even running balance with a -dusage=0 filter failed with
ENOSPC as well. Also unmounting and mounting again the filesystem didn't
help. Allowing the cleaner kthread to use the global block reserve to
delete the unused data block groups fixed the problem.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
I want to set some per transaction flags, so instead of adding yet another int
lets just convert the current two int indicators to flags and add a flags field
for future use. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
We have a mechanism to make sure we don't lose updates for ordered extents that
were logged in the transaction that is currently running. We add the ordered
extent to a transaction list and then the transaction waits on all the ordered
extents in that list. However are substantially large file systems this list
can be extremely large, and can give us soft lockups, since the ordered extents
don't remove themselves from the list when they do complete.
To fix this we simply add a counter to the transaction that is incremented any
time we have a logged extent that needs to be completed in the current
transaction. Then when the ordered extent finally completes it decrements the
per transaction counter and wakes up the transaction if we are the last ones.
This will eliminate the softlockup. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
As we have the new metadata reservation functions, use them to replace
the old btrfs_qgroup_reserve() call for metadata.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
The value of num_items that start_transaction() ultimately
always takes is a small one, so a 64 bit integer is overkill.
Also change num_items for btrfs_start_transaction() and
btrfs_start_transaction_lflush() as well.
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Use memset() to null out the btrfs_delayed_ref_root of
btrfs_transaction instead of setting all the members to 0 by hand.
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Just call kmem_cache_zalloc() instead of calling kmem_cache_alloc().
We're just initializing most fields to 0, false and NULL later on
_anyway_, so to make the code mode readable and potentially gain
a bit of performance (completely untested claim), we should fill our
btrfs_trans_handle with zeros on allocation then just initialize
those five remaining fields (not counting the list_heads) as normal.
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
waitqueue_active should be preceded by a barrier, in this function we
don't need to call it all the time.
Signed-off-by: David Sterba <dsterba@suse.com>
Pull btrfs fixes from Chris Mason:
"These are small and assorted. Neil's is the oldest, I dropped the
ball thinking he was going to send it in"
* 'for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: support NFSv2 export
Btrfs: open_ctree: Fix possible memory leak
Btrfs: fix deadlock when finalizing block group creation
Btrfs: update fix for read corruption of compressed and shared extents
Btrfs: send, fix corner case for reference overwrite detection
Josef ran into a deadlock while a transaction handle was finalizing the
creation of its block groups, which produced the following trace:
[260445.593112] fio D ffff88022a9df468 0 8924 4518 0x00000084
[260445.593119] ffff88022a9df468 ffffffff81c134c0 ffff880429693c00 ffff88022a9df488
[260445.593126] ffff88022a9e0000 ffff8803490d7b00 ffff8803490d7b18 ffff88022a9df4b0
[260445.593132] ffff8803490d7af8 ffff88022a9df488 ffffffff8175a437 ffff8803490d7b00
[260445.593137] Call Trace:
[260445.593145] [<ffffffff8175a437>] schedule+0x37/0x80
[260445.593189] [<ffffffffa0850f37>] btrfs_tree_lock+0xa7/0x1f0 [btrfs]
[260445.593197] [<ffffffff810db7c0>] ? prepare_to_wait_event+0xf0/0xf0
[260445.593225] [<ffffffffa07eac44>] btrfs_lock_root_node+0x34/0x50 [btrfs]
[260445.593253] [<ffffffffa07eff6b>] btrfs_search_slot+0x88b/0xa00 [btrfs]
[260445.593295] [<ffffffffa08389df>] ? free_extent_buffer+0x4f/0x90 [btrfs]
[260445.593324] [<ffffffffa07f1a06>] btrfs_insert_empty_items+0x66/0xc0 [btrfs]
[260445.593351] [<ffffffffa07ea94a>] ? btrfs_alloc_path+0x1a/0x20 [btrfs]
[260445.593394] [<ffffffffa08403b9>] btrfs_finish_chunk_alloc+0x1c9/0x570 [btrfs]
[260445.593427] [<ffffffffa08002ab>] btrfs_create_pending_block_groups+0x11b/0x200 [btrfs]
[260445.593459] [<ffffffffa0800964>] do_chunk_alloc+0x2a4/0x2e0 [btrfs]
[260445.593491] [<ffffffffa0803815>] find_free_extent+0xa55/0xd90 [btrfs]
[260445.593524] [<ffffffffa0803c22>] btrfs_reserve_extent+0xd2/0x220 [btrfs]
[260445.593532] [<ffffffff8119fe5d>] ? account_page_dirtied+0xdd/0x170
[260445.593564] [<ffffffffa0803e78>] btrfs_alloc_tree_block+0x108/0x4a0 [btrfs]
[260445.593597] [<ffffffffa080c9de>] ? btree_set_page_dirty+0xe/0x10 [btrfs]
[260445.593626] [<ffffffffa07eb5cd>] __btrfs_cow_block+0x12d/0x5b0 [btrfs]
[260445.593654] [<ffffffffa07ebbff>] btrfs_cow_block+0x11f/0x1c0 [btrfs]
[260445.593682] [<ffffffffa07ef8c7>] btrfs_search_slot+0x1e7/0xa00 [btrfs]
[260445.593724] [<ffffffffa08389df>] ? free_extent_buffer+0x4f/0x90 [btrfs]
[260445.593752] [<ffffffffa07f1a06>] btrfs_insert_empty_items+0x66/0xc0 [btrfs]
[260445.593830] [<ffffffffa07ea94a>] ? btrfs_alloc_path+0x1a/0x20 [btrfs]
[260445.593905] [<ffffffffa08403b9>] btrfs_finish_chunk_alloc+0x1c9/0x570 [btrfs]
[260445.593946] [<ffffffffa08002ab>] btrfs_create_pending_block_groups+0x11b/0x200 [btrfs]
[260445.593990] [<ffffffffa0815798>] btrfs_commit_transaction+0xa8/0xb40 [btrfs]
[260445.594042] [<ffffffffa085abcd>] ? btrfs_log_dentry_safe+0x6d/0x80 [btrfs]
[260445.594089] [<ffffffffa082bc84>] btrfs_sync_file+0x294/0x350 [btrfs]
[260445.594115] [<ffffffff8123e29b>] vfs_fsync_range+0x3b/0xa0
[260445.594133] [<ffffffff81023891>] ? syscall_trace_enter_phase1+0x131/0x180
[260445.594149] [<ffffffff8123e35d>] do_fsync+0x3d/0x70
[260445.594169] [<ffffffff81023bb8>] ? syscall_trace_leave+0xb8/0x110
[260445.594187] [<ffffffff8123e600>] SyS_fsync+0x10/0x20
[260445.594204] [<ffffffff8175de6e>] entry_SYSCALL_64_fastpath+0x12/0x71
This happened because the same transaction handle created a large number
of block groups and while finalizing their creation (inserting new items
and updating existing items in the chunk and device trees) a new metadata
extent had to be allocated and no free space was found in the current
metadata block groups, which made find_free_extent() attempt to allocate
a new block group via do_chunk_alloc(). However at do_chunk_alloc() we
ended up allocating a new system chunk too and exceeded the threshold
of 2Mb of reserved chunk bytes, which makes do_chunk_alloc() enter the
final part of block group creation again (at
btrfs_create_pending_block_groups()) and attempt to lock again the root
of the chunk tree when it's already write locked by the same task.
Similarly we can deadlock on extent tree nodes/leafs if while we are
running delayed references we end up creating a new metadata block group
in order to allocate a new node/leaf for the extent tree (as part of
a CoW operation or growing the tree), as btrfs_create_pending_block_groups
inserts items into the extent tree as well. In this case we get the
following trace:
[14242.773581] fio D ffff880428ca3418 0 3615 3100 0x00000084
[14242.773588] ffff880428ca3418 ffff88042d66b000 ffff88042a03c800 ffff880428ca3438
[14242.773594] ffff880428ca4000 ffff8803e4b20190 ffff8803e4b201a8 ffff880428ca3460
[14242.773600] ffff8803e4b20188 ffff880428ca3438 ffffffff8175a437 ffff8803e4b20190
[14242.773606] Call Trace:
[14242.773613] [<ffffffff8175a437>] schedule+0x37/0x80
[14242.773656] [<ffffffffa057ff07>] btrfs_tree_lock+0xa7/0x1f0 [btrfs]
[14242.773664] [<ffffffff810db7c0>] ? prepare_to_wait_event+0xf0/0xf0
[14242.773692] [<ffffffffa0519c44>] btrfs_lock_root_node+0x34/0x50 [btrfs]
[14242.773720] [<ffffffffa051ef6b>] btrfs_search_slot+0x88b/0xa00 [btrfs]
[14242.773750] [<ffffffffa0520a06>] btrfs_insert_empty_items+0x66/0xc0 [btrfs]
[14242.773758] [<ffffffff811ef4a2>] ? kmem_cache_alloc+0x1d2/0x200
[14242.773786] [<ffffffffa0520ad1>] btrfs_insert_item+0x71/0xf0 [btrfs]
[14242.773818] [<ffffffffa052f292>] btrfs_create_pending_block_groups+0x102/0x200 [btrfs]
[14242.773850] [<ffffffffa052f96e>] do_chunk_alloc+0x2ae/0x2f0 [btrfs]
[14242.773934] [<ffffffffa0532825>] find_free_extent+0xa55/0xd90 [btrfs]
[14242.773998] [<ffffffffa0532c22>] btrfs_reserve_extent+0xc2/0x1d0 [btrfs]
[14242.774041] [<ffffffffa0532e38>] btrfs_alloc_tree_block+0x108/0x4a0 [btrfs]
[14242.774078] [<ffffffffa051a5cd>] __btrfs_cow_block+0x12d/0x5b0 [btrfs]
[14242.774118] [<ffffffffa051abff>] btrfs_cow_block+0x11f/0x1c0 [btrfs]
[14242.774155] [<ffffffffa051e8c7>] btrfs_search_slot+0x1e7/0xa00 [btrfs]
[14242.774194] [<ffffffffa0528021>] ? __btrfs_free_extent.isra.70+0x2e1/0xcb0 [btrfs]
[14242.774235] [<ffffffffa0520a06>] btrfs_insert_empty_items+0x66/0xc0 [btrfs]
[14242.774274] [<ffffffffa051994a>] ? btrfs_alloc_path+0x1a/0x20 [btrfs]
[14242.774318] [<ffffffffa052c433>] __btrfs_run_delayed_refs+0xbb3/0x1020 [btrfs]
[14242.774358] [<ffffffffa052f404>] btrfs_run_delayed_refs.part.78+0x74/0x280 [btrfs]
[14242.774391] [<ffffffffa052f627>] btrfs_run_delayed_refs+0x17/0x20 [btrfs]
[14242.774432] [<ffffffffa05be236>] commit_cowonly_roots+0x8d/0x2bd [btrfs]
[14242.774474] [<ffffffffa059d07f>] ? __btrfs_run_delayed_items+0x1cf/0x210 [btrfs]
[14242.774516] [<ffffffffa05adac3>] ? btrfs_qgroup_account_extents+0x83/0x130 [btrfs]
[14242.774558] [<ffffffffa0544c40>] btrfs_commit_transaction+0x590/0xb40 [btrfs]
[14242.774599] [<ffffffffa0589b9d>] ? btrfs_log_dentry_safe+0x6d/0x80 [btrfs]
[14242.774642] [<ffffffffa055ac54>] btrfs_sync_file+0x294/0x350 [btrfs]
[14242.774650] [<ffffffff8123e29b>] vfs_fsync_range+0x3b/0xa0
[14242.774657] [<ffffffff81023891>] ? syscall_trace_enter_phase1+0x131/0x180
[14242.774663] [<ffffffff8123e35d>] do_fsync+0x3d/0x70
[14242.774669] [<ffffffff81023bb8>] ? syscall_trace_leave+0xb8/0x110
[14242.774675] [<ffffffff8123e600>] SyS_fsync+0x10/0x20
[14242.774681] [<ffffffff8175de6e>] entry_SYSCALL_64_fastpath+0x12/0x71
Fix this by never recursing into the finalization phase of block group
creation and making sure we never trigger the finalization of block group
creation while running delayed references.
Reported-by: Josef Bacik <jbacik@fb.com>
Fixes: 00d80e342c ("Btrfs: fix quick exhaustion of the system array in the superblock")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
btrfs_error() and btrfs_std_error() does the same thing
and calls _btrfs_std_error(), so consolidate them together.
And the main motivation is that btrfs_error() is closely
named with btrfs_err(), one handles error action the other
is to log the error, so don't closely name them.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Suggested-by: David Sterba <dsterba@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Pull btrfs fixes from Chris Mason:
"This is an assorted set I've been queuing up:
Jeff Mahoney tracked down a tricky one where we ended up starting IO
on the wrong mapping for special files in btrfs_evict_inode. A few
people reported this one on the list.
Filipe found (and provided a test for) a difficult bug in reading
compressed extents, and Josef fixed up some quota record keeping with
snapshot deletion. Chandan killed off an accounting bug during DIO
that lead to WARN_ONs as we freed inodes"
* 'for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: keep dropped roots in cache until transaction commit
Btrfs: Direct I/O: Fix space accounting
btrfs: skip waiting on ordered range for special files
Btrfs: fix read corruption of compressed and shared extents
Btrfs: remove unnecessary locking of cleaner_mutex to avoid deadlock
Btrfs: don't initialize a space info as full to prevent ENOSPC
When dropping a snapshot we need to account for the qgroup changes. If we drop
the snapshot in all one go then the backref code will fail to find blocks from
the snapshot we dropped since it won't be able to find the root in the fs root
cache. This can lead to us failing to find refs from other roots that pointed
at blocks in the now deleted root. To handle this we need to not remove the fs
roots from the cache until after we process the qgroup operations. Do this by
adding dropped roots to a list on the transaction, and letting the transaction
remove the roots at the same time it drops the commit roots. This will keep all
of the backref searching code in sync properly, and fixes a problem Mark was
seeing with snapshot delete and qgroups. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Tested-by: Holger Hoffstätte <holger.hoffstaette@googlemail.com>
Signed-off-by: Chris Mason <clm@fb.com>
Pull vfs updates from Al Viro:
"In this one:
- d_move fixes (Eric Biederman)
- UFS fixes (me; locking is mostly sane now, a bunch of bugs in error
handling ought to be fixed)
- switch of sb_writers to percpu rwsem (Oleg Nesterov)
- superblock scalability (Josef Bacik and Dave Chinner)
- swapon(2) race fix (Hugh Dickins)"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (65 commits)
vfs: Test for and handle paths that are unreachable from their mnt_root
dcache: Reduce the scope of i_lock in d_splice_alias
dcache: Handle escaped paths in prepend_path
mm: fix potential data race in SyS_swapon
inode: don't softlockup when evicting inodes
inode: rename i_wb_list to i_io_list
sync: serialise per-superblock sync operations
inode: convert inode_sb_list_lock to per-sb
inode: add hlist_fake to avoid the inode hash lock in evict
writeback: plug writeback at a high level
change sb_writers to use percpu_rw_semaphore
shift percpu_counter_destroy() into destroy_super_work()
percpu-rwsem: kill CONFIG_PERCPU_RWSEM
percpu-rwsem: introduce percpu_rwsem_release() and percpu_rwsem_acquire()
percpu-rwsem: introduce percpu_down_read_trylock()
document rwsem_release() in sb_wait_write()
fix the broken lockdep logic in __sb_start_write()
introduce __sb_writers_{acquired,release}() helpers
ufs_inode_get{frag,block}(): get rid of 'phys' argument
ufs_getfrag_block(): tidy up a bit
...
While we are committing a transaction, it's possible the previous one is
still finishing its commit and therefore we wait for it to finish first.
However we were not checking if that previous transaction ended up getting
aborted after we waited for it to commit, so we ended up committing the
current transaction which can lead to fs corruption because the new
superblock can point to trees that have had one or more nodes/leafs that
were never durably persisted.
The following sequence diagram exemplifies how this is possible:
CPU 0 CPU 1
transaction N starts
(...)
btrfs_commit_transaction(N)
cur_trans->state = TRANS_STATE_COMMIT_START;
(...)
cur_trans->state = TRANS_STATE_COMMIT_DOING;
(...)
cur_trans->state = TRANS_STATE_UNBLOCKED;
root->fs_info->running_transaction = NULL;
btrfs_start_transaction()
--> starts transaction N + 1
btrfs_write_and_wait_transaction(trans, root);
--> starts writing all new or COWed ebs created
at transaction N
creates some new ebs, COWs some
existing ebs but doesn't COW or
deletes eb X
btrfs_commit_transaction(N + 1)
(...)
cur_trans->state = TRANS_STATE_COMMIT_START;
(...)
wait_for_commit(root, prev_trans);
--> prev_trans == transaction N
btrfs_write_and_wait_transaction() continues
writing ebs
--> fails writing eb X, we abort transaction N
and set bit BTRFS_FS_STATE_ERROR on
fs_info->fs_state, so no new transactions
can start after setting that bit
cleanup_transaction()
btrfs_cleanup_one_transaction()
wakes up task at CPU 1
continues, doesn't abort because
cur_trans->aborted (transaction N + 1)
is zero, and no checks for bit
BTRFS_FS_STATE_ERROR in fs_info->fs_state
are made
btrfs_write_and_wait_transaction(trans, root);
--> succeeds, no errors during writeback
write_ctree_super(trans, root, 0);
--> succeeds
--> we have now a superblock that points us
to some root that uses eb X, which was
never written to disk
In this scenario future attempts to read eb X from disk results in an
error message like "parent transid verify failed on X wanted Y found Z".
So fix this by aborting the current transaction if after waiting for the
previous transaction we verify that it was aborted.
Cc: stable@vger.kernel.org
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
Preparation to hide the sb->s_writers internals from xfs and btrfs.
Add 2 trivial define's they can use rather than play with ->s_writers
directly. No changes in btrfs/transaction.o and xfs/xfs_aops.o.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Jan Kara <jack@suse.com>
These arguments are not used in functions, remove them for cleanup
and make kernel stack happy.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
When we clear the dirty bits in btrfs_delete_unused_bgs for extents
in the empty block group, it results in btrfs_finish_extent_commit being
unable to discard the freed extents.
The block group removal patch added an alternate path to forget extents
other than btrfs_finish_extent_commit. As a result, any extents that
would be freed when the block group is removed aren't discarded. In my
test run, with a large copy of mixed sized files followed by removal, it
left nearly 2/3 of extents undiscarded.
To clean up the block groups, we add the removed block group onto a list
that will be discarded after transaction commit.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Tested-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
Liu Bo <bo.li.liu@oracle.com> reported a lockdep warning of
delayed_iput_sem in xfstests generic/241:
[ 2061.345955] =============================================
[ 2061.346027] [ INFO: possible recursive locking detected ]
[ 2061.346027] 4.1.0+ #268 Tainted: G W
[ 2061.346027] ---------------------------------------------
[ 2061.346027] btrfs-cleaner/3045 is trying to acquire lock:
[ 2061.346027] (&fs_info->delayed_iput_sem){++++..}, at:
[<ffffffff814063ab>] btrfs_run_delayed_iputs+0x6b/0x100
[ 2061.346027] but task is already holding lock:
[ 2061.346027] (&fs_info->delayed_iput_sem){++++..}, at: [<ffffffff814063ab>] btrfs_run_delayed_iputs+0x6b/0x100
[ 2061.346027] other info that might help us debug this:
[ 2061.346027] Possible unsafe locking scenario:
[ 2061.346027] CPU0
[ 2061.346027] ----
[ 2061.346027] lock(&fs_info->delayed_iput_sem);
[ 2061.346027] lock(&fs_info->delayed_iput_sem);
[ 2061.346027]
*** DEADLOCK ***
It is rarely happened, about 1/400 in my test env.
The reason is recursion of btrfs_run_delayed_iputs():
cleaner_kthread
-> btrfs_run_delayed_iputs() *1
-> get delayed_iput_sem lock *2
-> iput()
-> ...
-> btrfs_commit_transaction()
-> btrfs_run_delayed_iputs() *1
-> get delayed_iput_sem lock (dead lock) *2
*1: recursion of btrfs_run_delayed_iputs()
*2: warning of lockdep about delayed_iput_sem
When fs is in high stress, new iputs may added into fs_info->delayed_iputs
list when btrfs_run_delayed_iputs() is running, which cause
second btrfs_run_delayed_iputs() run into down_read(&fs_info->delayed_iput_sem)
again, and cause above lockdep warning.
Actually, it will not cause real problem because both locks are read lock,
but to avoid lockdep warning, we can do a fix.
Fix:
Don't do btrfs_run_delayed_iputs() in btrfs_commit_transaction() for
cleaner_kthread thread to break above recursion path.
cleaner_kthread is calling btrfs_run_delayed_iputs() explicitly in code,
and don't need to call btrfs_run_delayed_iputs() again in
btrfs_commit_transaction(), it also give us a bonus to avoid stack overflow.
Test:
No above lockdep warning after patch in 1200 generic/241 tests.
Reported-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
When we call btrfs_commit_transaction(), we splice the list "ordered"
of our transaction handle into the transaction's "pending_ordered"
list, but we don't re-initialize the "ordered" list of our transaction
handle, this means it still points to the same elements it used to
before the splice. Then we check if the current transaction's state is
>= TRANS_STATE_COMMIT_START and if it is we end up calling
btrfs_end_transaction() which simply splices again the "ordered" list
of our handle into the transaction's "pending_ordered" list, leaving
multiple pointers to the same ordered extents which results in list
corruption when we are iterating, removing and freeing ordered extents
at btrfs_wait_pending_ordered(), resulting in access to dangling
pointers / use-after-free issues.
Similarly, btrfs_end_transaction() can end up in some cases calling
btrfs_commit_transaction(), and both did a list splice of the transaction
handle's "ordered" list into the transaction's "pending_ordered" without
re-initializing the handle's "ordered" list, resulting in exactly the
same problem.
This produces the following warning on a kernel with linked list
debugging enabled:
[109749.265416] ------------[ cut here ]------------
[109749.266410] WARNING: CPU: 7 PID: 324 at lib/list_debug.c:59 __list_del_entry+0x5a/0x98()
[109749.267969] list_del corruption. prev->next should be ffff8800ba087e20, but was fffffff8c1f7c35d
(...)
[109749.287505] Call Trace:
[109749.288135] [<ffffffff8145f077>] dump_stack+0x4f/0x7b
[109749.298080] [<ffffffff81095de5>] ? console_unlock+0x356/0x3a2
[109749.331605] [<ffffffff8104b3b0>] warn_slowpath_common+0xa1/0xbb
[109749.334849] [<ffffffff81260642>] ? __list_del_entry+0x5a/0x98
[109749.337093] [<ffffffff8104b410>] warn_slowpath_fmt+0x46/0x48
[109749.337847] [<ffffffff81260642>] __list_del_entry+0x5a/0x98
[109749.338678] [<ffffffffa053e8bf>] btrfs_wait_pending_ordered+0x46/0xdb [btrfs]
[109749.340145] [<ffffffffa058a65f>] ? __btrfs_run_delayed_items+0x149/0x163 [btrfs]
[109749.348313] [<ffffffffa054077d>] btrfs_commit_transaction+0x36b/0xa10 [btrfs]
[109749.349745] [<ffffffff81087310>] ? trace_hardirqs_on+0xd/0xf
[109749.350819] [<ffffffffa055370d>] btrfs_sync_file+0x36f/0x3fc [btrfs]
[109749.351976] [<ffffffff8118ec98>] vfs_fsync_range+0x8f/0x9e
[109749.360341] [<ffffffff8118ecc3>] vfs_fsync+0x1c/0x1e
[109749.368828] [<ffffffff8118ee1d>] do_fsync+0x34/0x4e
[109749.369790] [<ffffffff8118f045>] SyS_fsync+0x10/0x14
[109749.370925] [<ffffffff81465197>] system_call_fastpath+0x12/0x6f
[109749.382274] ---[ end trace 48e0d07f7c03d95a ]---
On a non-debug kernel this leads to invalid memory accesses, causing a
crash. Fix this by using list_splice_init() instead of list_splice() in
btrfs_commit_transaction() and btrfs_end_transaction().
Cc: stable@vger.kernel.org
Fixes: 50d9aa99bd ("Btrfs: make sure logged extents complete in the current transaction V3"
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
qgroup.
Make snapshot accounting work with new extent-oriented mechanism by
skipping given root in new/old_roots in create_pending_snapshot().
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
This is used by later qgroup fix patches for snapshot.
As current snapshot accounting is done by btrfs_qgroup_inherit(), but
new extent oriented quota mechanism will account extent from
btrfs_copy_root() and other snapshot things, causing wrong result.
So add this ability to handle snapshot accounting.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
Switch from old ref_node based qgroup to extent based qgroup mechanism
for normal operations.
The new mechanism should hugely reduce the overhead of btrfs quota
system, and further more, the codes and logic should be more clean and
easier to maintain.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
Add hook in add_delayed_ref_head() to record quota-related extent record
into delayed_ref_root->dirty_extent_record rb-tree for later qgroup
accounting.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
While creating a block group, we often end up getting ENOSPC while updating
the chunk tree, which leads to a transaction abortion that produces a trace
like the following:
[30670.116368] WARNING: CPU: 4 PID: 20735 at fs/btrfs/super.c:260 __btrfs_abort_transaction+0x52/0x106 [btrfs]()
[30670.117777] BTRFS: Transaction aborted (error -28)
(...)
[30670.163567] Call Trace:
[30670.163906] [<ffffffff8142fa46>] dump_stack+0x4f/0x7b
[30670.164522] [<ffffffff8108b6a2>] ? console_unlock+0x361/0x3ad
[30670.165171] [<ffffffff81045ea5>] warn_slowpath_common+0xa1/0xbb
[30670.166323] [<ffffffffa035daa7>] ? __btrfs_abort_transaction+0x52/0x106 [btrfs]
[30670.167213] [<ffffffff81045f05>] warn_slowpath_fmt+0x46/0x48
[30670.167862] [<ffffffffa035daa7>] __btrfs_abort_transaction+0x52/0x106 [btrfs]
[30670.169116] [<ffffffffa03743d7>] btrfs_create_pending_block_groups+0x101/0x130 [btrfs]
[30670.170593] [<ffffffffa038426a>] __btrfs_end_transaction+0x84/0x366 [btrfs]
[30670.171960] [<ffffffffa038455c>] btrfs_end_transaction+0x10/0x12 [btrfs]
[30670.174649] [<ffffffffa036eb6b>] btrfs_check_data_free_space+0x11f/0x27c [btrfs]
[30670.176092] [<ffffffffa039450d>] btrfs_fallocate+0x7c8/0xb96 [btrfs]
[30670.177218] [<ffffffff812459f2>] ? __this_cpu_preempt_check+0x13/0x15
[30670.178622] [<ffffffff81152447>] vfs_fallocate+0x14c/0x1de
[30670.179642] [<ffffffff8116b915>] ? __fget_light+0x2d/0x4f
[30670.180692] [<ffffffff81152863>] SyS_fallocate+0x47/0x62
[30670.186737] [<ffffffff81435b32>] system_call_fastpath+0x12/0x17
[30670.187792] ---[ end trace 0373e6b491c4a8cc ]---
This is because we don't do proper space reservation for the chunk block
reserve when we have multiple tasks allocating chunks in parallel.
So block group creation has 2 phases, and the first phase essentially
checks if there is enough space in the system space_info, allocating a
new system chunk if there isn't, while the second phase updates the
device, extent and chunk trees. However, because the updates to the
chunk tree happen in the second phase, if we have N tasks, each with
its own transaction handle, allocating new chunks in parallel and if
there is only enough space in the system space_info to allocate M chunks,
where M < N, none of the tasks ends up allocating a new system chunk in
the first phase and N - M tasks will get -ENOSPC when attempting to
update the chunk tree in phase 2 if they need to COW any nodes/leafs
from the chunk tree.
Fix this by doing proper reservation in the chunk block reserve.
The issue could be reproduced by running fstests generic/038 in a loop,
which eventually triggered the problem.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
We loop through all of the dirty block groups during commit and write
the free space cache. In order to make sure the cache is currect, we do
this while no other writers are allowed in the commit.
If a large number of block groups are dirty, this can introduce long
stalls during the final stages of the commit, which can block new procs
trying to change the filesystem.
This commit changes the block group cache writeout to take appropriate
locks and allow it to run earlier in the commit. We'll still have to
redo some of the block groups, but it means we can get most of the work
out of the way without blocking the entire FS.
Signed-off-by: Chris Mason <clm@fb.com>
As we delete large extents, we end up doing huge amounts of COW in order
to delete the corresponding crcs. This adds accounting so that we keep
track of that space and flushing of delayed refs so that we don't build
up too much delayed crc work.
This helps limit the delayed work that must be done at commit time and
tries to avoid ENOSPC aborts because the crcs eat all the global
reserves.
Signed-off-by: Chris Mason <clm@fb.com>
When we are deleting large files with large extents, we are building up
a huge set of delayed refs for processing. Truncate isn't checking
often enough to see if we need to back off and process those, or let
a commit proceed.
The end result is long stalls after the rm, and very long commit times.
During the commits, other processes back up waiting to start new
transactions and we get into trouble.
Signed-off-by: Chris Mason <clm@fb.com>
Pull btrfs fixes from Chris Mason:
"Most of these are fixing extent reservation accounting, or corners
with tree writeback during commit.
Josef's set does add a test, which isn't strictly a fix, but it'll
keep us from making this same mistake again"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: fix outstanding_extents accounting in DIO
Btrfs: add sanity test for outstanding_extents accounting
Btrfs: just free dummy extent buffers
Btrfs: account merges/splits properly
Btrfs: prepare block group cache before writing
Btrfs: fix ASSERT(list_empty(&cur_trans->dirty_bgs_list)
Btrfs: account for the correct number of extents for delalloc reservations
Btrfs: fix merge delalloc logic
Btrfs: fix comp_oper to get right order
Btrfs: catch transaction abortion after waiting for it
btrfs: fix sizeof format specifier in btrfs_check_super_valid()
Writing the block group cache will modify the extent tree quite a bit because it
truncates the old space cache and pre-allocates new stuff. To try and cut down
on the churn lets do the setup dance first, then later on hopefully we can avoid
looping with newly dirtied roots. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
