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2017-02-17btrfs: qgroup: Move half of the qgroup accounting time out of commit transGravatar Qu Wenruo 1-4/+29
Just as Filipe pointed out, the most time consuming parts of qgroup are btrfs_qgroup_account_extents() and btrfs_qgroup_prepare_account_extents(). Which both call btrfs_find_all_roots() to get old_roots and new_roots ulist. What makes things worse is, we're calling that expensive btrfs_find_all_roots() at transaction committing time with TRANS_STATE_COMMIT_DOING, which will blocks all incoming transaction. Such behavior is necessary for @new_roots search as current btrfs_find_all_roots() can't do it correctly so we do call it just before switch commit roots. However for @old_roots search, it's not necessary as such search is based on commit_root, so it will always be correct and we can move it out of transaction committing. This patch moves the @old_roots search part out of commit_transaction(), so in theory we can half the time qgroup time consumption at commit_transaction(). But please note that, this won't speedup qgroup overall, the total time consumption is still the same, just reduce the performance stall. Cc: Filipe Manana <fdmanana@suse.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-17btrfs: remove unused parameter from adjust_slots_upwardsGravatar David Sterba 1-3/+2
Never used. Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-17btrfs: remove unused parameter from clean_tree_blockGravatar David Sterba 1-1/+1
Added but never needed. Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-17btrfs: ulist: rename ulist_fini to ulist_releaseGravatar David Sterba 1-4/+4
Change the name so it matches the naming we already use eg. for btrfs_path. Suggested-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-17btrfs: remove pointless rcu protection from btrfs_qgroup_inheritGravatar David Sterba 1-2/+0
There was never need for RCU protection around reading nodesize or other fairly constant filesystem data. Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-17btrfs: qgroups: opencode qgroup_free helperGravatar David Sterba 1-9/+9
The helper name is not too helpful and is just wrapping a simple call. Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-17btrfs: check quota status earlier and don't do unnecessary freesGravatar David Sterba 1-2/+3
Status of quotas should be the first check in btrfs_qgroup_account_extent and we can return immediatelly, no need to do no-op ulist frees. Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-17btrfs: embed extent_changeset::range_changed to the structureGravatar David Sterba 1-15/+9
We can embed range_changed to the extent changeset to address following problems: - no need to allocate ulist dynamically, we also get rid of the GFP_NOFS for free - fix lack of allocation failure checking in btrfs_qgroup_reserve_data The stack consuption where extent_changeset is used slightly increases: before: 16 after: 16 - 8 (for pointer) + 32 (sizeof ulist) = 40 Which is bearable. Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-17btrfs: qgroups: make __del_qgroup_relation staticGravatar David Sterba 1-1/+1
Internal helper. Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-17btrfs: use GFP_KERNEL in btrfs_add/del_qgroup_relationGravatar David Sterba 1-2/+2
Qgroup relations are added/deleted from ioctl, we hold the high level qgroup lock, no deadlocks or recursion from the allocation possible here. Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-17btrfs: use GFP_KERNEL in btrfs_quota_enableGravatar David Sterba 1-1/+1
We don't need to use GFP_NOFS here as this is called from ioctls an the only lock held is the subvol_sem, which is of a high level and protects creation/renames/deletion and is never held in the writeout paths. Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-17btrfs: use GFP_KERNEL in btrfs_read_qgroup_configGravatar David Sterba 1-1/+1
The qgroup config is read during mount, we do not have to use NOFS. Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-14btrfs: allow unlink to exceed subvolume quotaGravatar Jeff Mahoney 1-14/+19
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>
2017-02-14btrfs: Add WARN_ON for qgroup reserved underflowGravatar Qu Wenruo 1-5/+26
Goldwyn Rodrigues has exposed and fixed a bug which underflows btrfs qgroup reserved space, and leads to non-writable fs. This reminds us that we don't have enough underflow check for qgroup reserved space. For underflow case, we should not really underflow the numbers but warn and keeps qgroup still work. So add more check on qgroup reserved space and add WARN_ON() and btrfs_warn() for any underflow case. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-12-13Merge branch 'for-chris-4.10' of ↵Gravatar Chris Mason 1-4/+1
git://git.kernel.org/pub/scm/linux/kernel/git/fdmanana/linux into for-linus-4.10 Patches queued up by Filipe: The most important change is still the fix for the extent tree corruption that happens due to balance when qgroups are enabled (a regression introduced in 4.7 by a fix for a regression from the last qgroups rework). This has been hitting SLE and openSUSE users and QA very badly, where transactions keep getting aborted when running delayed references leaving the root filesystem in RO mode and nearly unusable. There are fixes here that allow us to run xfstests again with the integrity checker enabled, which has been impossible since 4.8 (apparently I'm the only one running xfstests with the integrity checker enabled, which is useful to validate dirtied leafs, like checking if there are keys out of order, etc). The rest are just some trivial fixes, most of them tagged for stable, and two cleanups. Signed-off-by: Chris Mason <clm@fb.com>
2016-12-06btrfs: remove root parameter from transaction commit/end routinesGravatar Jeff Mahoney 1-4/+4
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>
2016-12-06btrfs: take an fs_info directly when the root is not used otherwiseGravatar Jeff Mahoney 1-8/+6
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>
2016-12-06btrfs: root->fs_info cleanup, add fs_info convenience variablesGravatar Jeff Mahoney 1-18/+24
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>
2016-12-06btrfs: pull node/sector/stripe sizes out of root and into fs_infoGravatar Jeff Mahoney 1-5/+5
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>
2016-11-30btrfs: Export and move leaf/subtree qgroup helpers to qgroup.cGravatar Qu Wenruo 1-0/+213
Move account_shared_subtree() to qgroup.c and rename it to btrfs_qgroup_trace_subtree(). Do the same thing for account_leaf_items() and rename it to btrfs_qgroup_trace_leaf_items(). Since all these functions are only for qgroup, move them to qgroup.c and export them is more appropriate. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-and-Tested-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-11-30btrfs: qgroup: Rename functions to make it follow reserve,trace,account stepsGravatar Qu Wenruo 1-4/+4
Rename btrfs_qgroup_insert_dirty_extent(_nolock) to btrfs_qgroup_trace_extent(_nolock), according to the new reserve/trace/account naming schema. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-and-Tested-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-11-30btrfs: rename helper macros for qgroup and aux data castsGravatar David Sterba 1-14/+21
The helpers are not meant to be generic, the name is misleading. Convert them to static inlines for type checking. Signed-off-by: David Sterba <dsterba@suse.com>
2016-11-25Btrfs: fix qgroup rescan worker initializationGravatar Filipe Manana 1-4/+1
We were setting the qgroup_rescan_running flag to true only after the rescan worker started (which is a task run by a queue). So if a user space task starts a rescan and immediately after asks to wait for the rescan worker to finish, this second call might happen before the rescan worker task starts running, in which case the rescan wait ioctl returns immediatley, not waiting for the rescan worker to finish. This was making the fstest btrfs/022 fail very often. Fixes: d2c609b834d6 (btrfs: properly track when rescan worker is running) Cc: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com>
2016-09-26btrfs: convert pr_* to btrfs_* where possibleGravatar Jeff Mahoney 1-5/+6
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>
2016-09-26btrfs: unsplit printed stringsGravatar Jeff Mahoney 1-6/+5
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>
2016-09-26Btrfs: add a flags field to btrfs_fs_infoGravatar Josef Bacik 1-25/+30
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>
2016-08-25btrfs: qgroup: Refactor btrfs_qgroup_insert_dirty_extent()Gravatar Qu Wenruo 1-6/+35
Refactor btrfs_qgroup_insert_dirty_extent() function, to two functions: 1. btrfs_qgroup_insert_dirty_extent_nolock() Almost the same with original code. For delayed_ref usage, which has delayed refs locked. Change the return value type to int, since caller never needs the pointer, but only needs to know if they need to free the allocated memory. 2. btrfs_qgroup_insert_dirty_extent() The more encapsulated version. Will do the delayed_refs lock, memory allocation, quota enabled check and other things. The original design is to keep exported functions to minimal, but since more btrfs hacks exposed, like replacing path in balance, we need to record dirty extents manually, so we have to add such functions. Also, add comment for both functions, to info developers how to keep qgroup correct when doing hacks. Cc: Mark Fasheh <mfasheh@suse.de> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-and-Tested-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-25btrfs: waiting on qgroup rescan should not always be interruptibleGravatar Jeff Mahoney 1-3/+9
We wait on qgroup rescan completion in three places: file system shutdown, the quota disable ioctl, and the rescan wait ioctl. If the user sends a signal while we're waiting, we continue happily along. This is expected behavior for the rescan wait ioctl. It's racy in the shutdown path but mostly works due to other unrelated synchronization points. In the quota disable path, it Oopses the kernel pretty much immediately. Cc: <stable@vger.kernel.org> # v4.4+ Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-25btrfs: properly track when rescan worker is runningGravatar Jeff Mahoney 1-1/+8
The qgroup_flags field is overloaded such that it reflects the on-disk status of qgroups and the runtime state. The BTRFS_QGROUP_STATUS_FLAG_RESCAN flag is used to indicate that a rescan operation is in progress, but if the file system is unmounted while a rescan is running, the rescan operation is paused. If the file system is then mounted read-only, the flag will still be present but the rescan operation will not have been resumed. When we go to umount, btrfs_qgroup_wait_for_completion will see the flag and interpret it to mean that the rescan worker is still running and will wait for a completion that will never come. This patch uses a separate flag to indicate when the worker is running. The locking and state surrounding the qgroup rescan worker needs a lot of attention beyond this patch but this is enough to avoid a hung umount. Cc: <stable@vger.kernel.org> # v4.4+ Signed-off-by; Jeff Mahoney <jeffm@suse.com> Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-07-26btrfs: add btrfs_trans_handle->fs_info pointerGravatar Jeff Mahoney 1-1/+1
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>
2016-07-26btrfs: tests, use BTRFS_FS_STATE_DUMMY_FS_INFO instead of dummy rootGravatar Jeff Mahoney 1-2/+2
Now that we have a dummy fs_info associated with each test that uses a root, we don't need the DUMMY_ROOT bit anymore. This lets us make choices without needing an actual root like in e.g. btrfs_find_create_tree_block. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26btrfs: prefix fsid to all trace eventsGravatar Jeff Mahoney 1-9/+10
When using trace events to debug a problem, it's impossible to determine which file system generated a particular event. This patch adds a macro to prefix standard information to the head of a trace event. The extent_state alloc/free events are all that's left without an fs_info available. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-25btrfs: fix string and comment grammatical issues and typosGravatar Nicholas D Steeves 1-8/+8
Signed-off-by: Nicholas D Steeves <nsteeves@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-29btrfs: sink gfp parameter to set_record_extent_bitsGravatar David Sterba 1-2/+1
Single caller passes GFP_NOFS. Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-29btrfs: sink gfp parameter to clear_record_extent_bitsGravatar David Sterba 1-3/+2
Callers pass GFP_NOFS. No need to pass the flags around. Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-04btrfs: Add qgroup tracingGravatar Mark Fasheh 1-0/+9
This patch adds tracepoints to the qgroup code on both the reporting side (insert_dirty_extents) and the accounting side. Taken together it allows us to see what qgroup operations have happened, and what their result was. Signed-off-by: Mark Fasheh <mfasheh@suse.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-04btrfs: handle non-fatal errors in btrfs_qgroup_inherit()Gravatar Mark Fasheh 1-22/+32
create_pending_snapshot() will go readonly on _any_ error return from btrfs_qgroup_inherit(). If qgroups are enabled, a user can crash their fs by just making a snapshot and asking it to inherit from an invalid qgroup. For example: $ btrfs sub snap -i 1/10 /btrfs/ /btrfs/foo Will cause a transaction abort. Fix this by only throwing errors in btrfs_qgroup_inherit() when we know going readonly is acceptable. The following xfstests test case reproduces this bug: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" here=`pwd` tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { cd / rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter # remove previous $seqres.full before test rm -f $seqres.full # real QA test starts here _supported_fs btrfs _supported_os Linux _require_scratch rm -f $seqres.full _scratch_mkfs _scratch_mount _run_btrfs_util_prog quota enable $SCRATCH_MNT # The qgroup '1/10' does not exist and should be silently ignored _run_btrfs_util_prog subvolume snapshot -i 1/10 $SCRATCH_MNT $SCRATCH_MNT/snap1 _scratch_unmount echo "Silence is golden" status=0 exit Signed-off-by: Mark Fasheh <mfasheh@suse.de> Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
2015-11-25btrfs: qgroup: account shared subtree during snapshot deleteGravatar Mark Fasheh 1-0/+2
Commit 0ed4792 ('btrfs: qgroup: Switch to new extent-oriented qgroup mechanism.') removed our qgroup accounting during btrfs_drop_snapshot(). Predictably, this results in qgroup numbers going bad shortly after a snapshot is removed. Fix this by adding a dirty extent record when we encounter extents during our shared subtree walk. This effectively restores the functionality we had with the original shared subtree walking code in 1152651 (btrfs: qgroup: account shared subtrees during snapshot delete). The idea with the original patch (and this one) is that shared subtrees can get skipped during drop_snapshot. The shared subtree walk then allows us a chance to visit those extents and add them to the qgroup work for later processing. This ultimately makes the accounting for drop snapshot work. The new qgroup code nicely handles all the other extents during the tree walk via the ref dec/inc functions so we don't have to add actions beyond what we had originally. Signed-off-by: Mark Fasheh <mfasheh@suse.de> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-25btrfs: qgroup: fix quota disable during rescanGravatar Justin Maggard 1-1/+2
There's a race condition that leads to a NULL pointer dereference if you disable quotas while a quota rescan is running. To fix this, we just need to wait for the quota rescan worker to actually exit before tearing down the quota structures. Signed-off-by: Justin Maggard <jmaggard@netgear.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-05Btrfs: fix sleeping inside atomic context in qgroup rescan workerGravatar Filipe Manana 1-1/+0
We are holding a btree path with spinning locks and then we attempt to clone an extent buffer, which calls kmem_cache_alloc() and this function can sleep, causing the following trace to be reported on a debug kernel: [107118.218536] BUG: sleeping function called from invalid context at mm/slab.c:2871 [107118.224110] in_atomic(): 1, irqs_disabled(): 0, pid: 19148, name: kworker/u32:3 [107118.226120] INFO: lockdep is turned off. [107118.226843] Preemption disabled at:[<ffffffffa05ffa22>] btrfs_clear_lock_blocking_rw+0x96/0xea [btrfs] [107118.229175] CPU: 3 PID: 19148 Comm: kworker/u32:3 Tainted: G W 4.3.0-rc5-btrfs-next-17+ #1 [107118.231326] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014 [107118.233687] Workqueue: btrfs-qgroup-rescan btrfs_qgroup_rescan_helper [btrfs] [107118.236835] 0000000000000000 ffff880424bf3b78 ffffffff812566f4 0000000000000000 [107118.238369] ffff880424bf3ba0 ffffffff81070664 ffffffff817f1cd5 0000000000000b37 [107118.239769] 0000000000000000 ffff880424bf3bc8 ffffffff8107070a 0000000000008850 [107118.241244] Call Trace: [107118.241729] [<ffffffff812566f4>] dump_stack+0x4e/0x79 [107118.242602] [<ffffffff81070664>] ___might_sleep+0x23a/0x241 [107118.243586] [<ffffffff8107070a>] __might_sleep+0x9f/0xa6 [107118.244532] [<ffffffff8115af70>] cache_alloc_debugcheck_before+0x25/0x36 [107118.245939] [<ffffffff8115d52b>] kmem_cache_alloc+0x50/0x215 [107118.246930] [<ffffffffa05e627e>] __alloc_extent_buffer+0x2a/0x11f [btrfs] [107118.248121] [<ffffffffa05ecb1a>] btrfs_clone_extent_buffer+0x3d/0xdd [btrfs] [107118.249451] [<ffffffffa06239ea>] btrfs_qgroup_rescan_worker+0x16d/0x434 [btrfs] [107118.250755] [<ffffffff81087481>] ? arch_local_irq_save+0x9/0xc [107118.251754] [<ffffffffa05f7952>] normal_work_helper+0x14c/0x32a [btrfs] [107118.252899] [<ffffffffa05f7952>] ? normal_work_helper+0x14c/0x32a [btrfs] [107118.254195] [<ffffffffa05f7c82>] btrfs_qgroup_rescan_helper+0x12/0x14 [btrfs] [107118.255436] [<ffffffff81063b23>] process_one_work+0x24a/0x4ac [107118.263690] [<ffffffff81064285>] worker_thread+0x206/0x2c2 [107118.264888] [<ffffffff8106407f>] ? rescuer_thread+0x2cb/0x2cb [107118.267413] [<ffffffff8106904d>] kthread+0xef/0xf7 [107118.268417] [<ffffffff81068f5e>] ? kthread_parkme+0x24/0x24 [107118.269505] [<ffffffff8147d10f>] ret_from_fork+0x3f/0x70 [107118.270491] [<ffffffff81068f5e>] ? kthread_parkme+0x24/0x24 So just use blocking locks for our path to solve this. This fixes the patch titled: "btrfs: qgroup: Don't copy extent buffer to do qgroup rescan" Signed-off-by: Filipe Manana <fdmanana@suse.com>
2015-11-05Btrfs: fix race waiting for qgroup rescan workerGravatar Filipe Manana 1-2/+1
We were initializing the completion (fs_info->qgroup_rescan_completion) object after releasing the qgroup rescan lock, which gives a small time window for a rescan waiter to not actually wait for the rescan worker to finish. Example: CPU 1 CPU 2 fs_info->qgroup_rescan_completion->done is 0 btrfs_qgroup_rescan_worker() complete_all(&fs_info->qgroup_rescan_completion) sets fs_info->qgroup_rescan_completion->done to UINT_MAX / 2 ... do some other stuff .... qgroup_rescan_init() mutex_lock(&fs_info->qgroup_rescan_lock) set flag BTRFS_QGROUP_STATUS_FLAG_RESCAN in fs_info->qgroup_flags mutex_unlock(&fs_info->qgroup_rescan_lock) btrfs_qgroup_wait_for_completion() mutex_lock(&fs_info->qgroup_rescan_lock) sees flag BTRFS_QGROUP_STATUS_FLAG_RESCAN in fs_info->qgroup_flags mutex_unlock(&fs_info->qgroup_rescan_lock) wait_for_completion_interruptible( &fs_info->qgroup_rescan_completion) fs_info->qgroup_rescan_completion->done is > 0 so it returns immediately init_completion(&fs_info->qgroup_rescan_completion) sets fs_info->qgroup_rescan_completion->done to 0 So fix this by initializing the completion object while holding the mutex fs_info->qgroup_rescan_lock. Signed-off-by: Filipe Manana <fdmanana@suse.com>
2015-11-05btrfs: qgroup: exit the rescan worker during umountGravatar Justin Maggard 1-3/+6
I was hitting a consistent NULL pointer dereference during shutdown that showed the trace running through end_workqueue_bio(). I traced it back to the endio_meta_workers workqueue being poked after it had already been destroyed. Eventually I found that the root cause was a qgroup rescan that was still in progress while we were stopping all the btrfs workers. Currently we explicitly pause balance and scrub operations in close_ctree(), but we do nothing to stop the qgroup rescan. We should probably be doing the same for qgroup rescan, but that's a much larger change. This small change is good enough to allow me to unmount without crashing. Signed-off-by: Justin Maggard <jmaggard@netgear.com> Reviewed-by: Filipe Manana <fdmanana@suse.com>
2015-10-26btrfs: qgroup: Fix a rebase bug which will cause qgroup double freeGravatar Qu Wenruo 1-4/+0
When rebasing my patchset, I forgot to pick up a cleanup patch to remove old hotfix in 4.2 release. Witouth the cleanup, it will screw up new qgroup reserve framework and always cause minus reserved number. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-10-26btrfs: qgroup: Don't copy extent buffer to do qgroup rescanGravatar Qu Wenruo 1-10/+16
Ancient qgroup code call memcpy() on a extent buffer and use it for leaf iteration. As extent buffer contains lock, pointers to pages, it's never sane to do such copy. The following bug may be caused by this insane operation: [92098.841309] general protection fault: 0000 [#1] SMP [92098.841338] Modules linked in: ... [92098.841814] CPU: 1 PID: 24655 Comm: kworker/u4:12 Not tainted 4.3.0-rc1 #1 [92098.841868] Workqueue: btrfs-qgroup-rescan btrfs_qgroup_rescan_helper [btrfs] [92098.842261] Call Trace: [92098.842277] [<ffffffffc035a5d8>] ? read_extent_buffer+0xb8/0x110 [btrfs] [92098.842304] [<ffffffffc0396d00>] ? btrfs_find_all_roots+0x60/0x70 [btrfs] [92098.842329] [<ffffffffc039af3d>] btrfs_qgroup_rescan_worker+0x28d/0x5a0 [btrfs] Where btrfs_qgroup_rescan_worker+0x28d is btrfs_disk_key_to_cpu(), called in reading key from the copied extent_buffer. This patch will use btrfs_clone_extent_buffer() to a better copy of extent buffer to deal such case. Reported-by: Stephane Lesimple <stephane_btrfs@lesimple.fr> Suggested-by: Filipe Manana <fdmanana@kernel.org> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-10-21btrfs: qgroup: Check if qgroup reserved space leakedGravatar Qu Wenruo 1-0/+32
Add check at btrfs_destroy_inode() time to detect qgroup reserved space leak. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-10-21btrfs: qgroup: Add new trace point for qgroup data reserveGravatar Qu Wenruo 1-2/+9
Now each qgroup reserve for data will has its ftrace event for better debugging. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-10-21btrfs: qgroup: Cleanup old inaccurate facilitiesGravatar Qu Wenruo 1-7/+11
Cleanup the old facilities which use old btrfs_qgroup_reserve() function call, replace them with the newer version, and remove the "__" prefix in them. Also, make btrfs_qgroup_reserve/free() functions private, as they are now only used inside qgroup codes. Now, the whole btrfs qgroup is swithed to use the new reserve facilities. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-10-21btrfs: qgroup: Introduce new functions to reserve/free metadataGravatar Qu Wenruo 1-0/+40
Introduce new functions btrfs_qgroup_reserve/free_meta() to reserve/free metadata reserved space. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-10-21btrfs: delayed_ref: release and free qgroup reserved at proper timingGravatar Qu Wenruo 1-3/+2
Qgroup reserved space needs to be released from inode dirty map and get freed at different timing: 1) Release when the metadata is written into tree After corresponding metadata is written into tree, any newer write will be COWed(don't include NOCOW case yet). So we must release its range from inode dirty range map, or we will forget to reserve needed range, causing accounting exceeding the limit. 2) Free reserved bytes when delayed ref is run When delayed refs are run, qgroup accounting will follow soon and turn the reserved bytes into rfer/excl numbers. As run_delayed_refs and qgroup accounting are all done at commit_transaction() time, we are safe to free reserved space in run_delayed_ref time(). With these timing to release/free reserved space, we should be able to resolve the long existing qgroup reserve space leak problem. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-10-21btrfs: qgroup: Introduce functions to release/free qgroup reserve dataGravatar Qu Wenruo 1-0/+60
space Introduce functions btrfs_qgroup_release/free_data() to release/free reserved data range. Release means, just remove the data range from io_tree, but doesn't free the reserved space. This is for normal buffered write case, when data is written into disc and its metadata is added into tree, its reserved space should still be kept until commit_trans(). So in that case, we only release dirty range, but keep the reserved space recorded some other place until commit_tran(). Free means not only remove data range, but also free reserved space. This is used for case for cleanup and invalidate page. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>