summaryrefslogtreecommitdiffstats
path: root/fs/btrfs/transaction.h
Commit message (Collapse)AuthorAgeFilesLines
* Btrfs: fix BUG_ON() casued by the reserved space migrationMiao Xie2013-11-111-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we did space balance and snapshot creation at the same time, we might meet the following oops: kernel BUG at fs/btrfs/inode.c:3038! [SNIP] Call Trace: [<ffffffffa0411ec7>] btrfs_orphan_cleanup+0x293/0x407 [btrfs] [<ffffffffa042dc45>] btrfs_mksubvol.isra.28+0x259/0x373 [btrfs] [<ffffffffa042de85>] btrfs_ioctl_snap_create_transid+0x126/0x156 [btrfs] [<ffffffffa042dff1>] btrfs_ioctl_snap_create_v2+0xd0/0x121 [btrfs] [<ffffffffa0430b2c>] btrfs_ioctl+0x414/0x1854 [btrfs] [<ffffffff813b60b7>] ? __do_page_fault+0x305/0x379 [<ffffffff811215a9>] vfs_ioctl+0x1d/0x39 [<ffffffff81121d7c>] do_vfs_ioctl+0x32d/0x3e2 [<ffffffff81057fe7>] ? finish_task_switch+0x80/0xb8 [<ffffffff81121e88>] SyS_ioctl+0x57/0x83 [<ffffffff813b39ff>] ? do_device_not_available+0x12/0x14 [<ffffffff813b99c2>] system_call_fastpath+0x16/0x1b [SNIP] RIP [<ffffffffa040da40>] btrfs_orphan_add+0xc3/0x126 [btrfs] The reason of the problem is that the relocation root creation stole the reserved space, which was reserved for orphan item deletion. There are several ways to fix this problem, one is to increasing the reserved space size of the space balace, and then we can use that space to create the relocation tree for each fs/file trees. But it is hard to calculate the suitable size because we doesn't know how many fs/file trees we need relocate. We fixed this problem by reserving the space for relocation root creation actively since the space it need is very small (one tree block, used for root node copy), then we use that reserved space to create the relocation tree. If we don't reserve space for relocation tree creation, we will use the reserved space of the balance. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: fix two use-after-free bugs with transaction cleanupJosef Bacik2013-11-111-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | I was noticing the slab redzone stuff going off every once and a while during transaction aborts. This was caused by two things 1) We would walk the pending snapshots and set their error to -ECANCELED. We don't need to do this, the snapshot stuff waits for a transaction commit and if there is a problem we just free our pending snapshot object and exit. Doing this was causing us to touch the pending snapshot object after the thing had already been freed. 2) We were freeing the transaction manually with wanton disregard for it's use_count reference counter. To fix this I cleaned up the transaction freeing loop to either wait for the transaction commit to finish if it was in the middle of that (since it will be cleaned and freed up there) or to do the cleanup oursevles. I also moved the global "kill all things dirty everywhere" stuff outside of the transaction cleanup loop since that only needs to be done once. With this patch I'm no longer seeing slab corruption because of use after frees. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* btrfs: mark some local function as 'static'Sergei Trofimovich2013-09-011-2/+0
| | | | | | | | Cc: Josef Bacik <jbacik@fusionio.com> Cc: Chris Mason <chris.mason@fusionio.com> Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: check to see if root_list is empty before adding it to dead rootsJosef Bacik2013-08-091-1/+1
| | | | | | | | | | A user reported a panic when running with autodefrag and deleting snapshots. This is because we could end up trying to add the root to the dead roots list twice. To fix this check to see if we are empty before adding ourselves to the dead roots list. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: make the chunk allocator completely tree locklessJosef Bacik2013-07-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | When adjusting the enospc rules for relocation I ran into a deadlock because we were relocating the only system chunk and that forced us to try and allocate a new system chunk while holding locks in the chunk tree, which caused us to deadlock. To fix this I've moved all of the dev extent addition and chunk addition out to the delayed chunk completion stuff. We still keep the in-memory stuff which makes sure everything is consistent. One change I had to make was to search the commit root of the device tree to find a free dev extent, and hold onto any chunk em's that we allocated in that transaction so we do not allocate the same dev extent twice. This has the side effect of fixing a bug with balance that has been there ever since balance existed. Basically you can free a block group and it's dev extent and then immediately allocate that dev extent for a new block group and write stuff to that dev extent, all within the same transaction. So if you happen to crash during a balance you could come back to a completely broken file system. This patch should keep these sort of things from happening in the future since we won't be able to allocate free'd dev extents until after the transaction commits. This has passed all of the xfstests and my super annoying stress test followed by a balance. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
* Btrfs: make the state of the transaction more readableMiao Xie2013-06-141-4/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We used 3 variants to track the state of the transaction, it was complex and wasted the memory space. Besides that, it was hard to understand that which types of the transaction handles should be blocked in each transaction state, so the developers often made mistakes. This patch improved the above problem. In this patch, we define 6 states for the transaction, enum btrfs_trans_state { TRANS_STATE_RUNNING = 0, TRANS_STATE_BLOCKED = 1, TRANS_STATE_COMMIT_START = 2, TRANS_STATE_COMMIT_DOING = 3, TRANS_STATE_UNBLOCKED = 4, TRANS_STATE_COMPLETED = 5, TRANS_STATE_MAX = 6, } and just use 1 variant to track those state. In order to make the blocked handle types for each state more clear, we introduce a array: unsigned int btrfs_blocked_trans_types[TRANS_STATE_MAX] = { [TRANS_STATE_RUNNING] = 0U, [TRANS_STATE_BLOCKED] = (__TRANS_USERSPACE | __TRANS_START), [TRANS_STATE_COMMIT_START] = (__TRANS_USERSPACE | __TRANS_START | __TRANS_ATTACH), [TRANS_STATE_COMMIT_DOING] = (__TRANS_USERSPACE | __TRANS_START | __TRANS_ATTACH | __TRANS_JOIN), [TRANS_STATE_UNBLOCKED] = (__TRANS_USERSPACE | __TRANS_START | __TRANS_ATTACH | __TRANS_JOIN | __TRANS_JOIN_NOLOCK), [TRANS_STATE_COMPLETED] = (__TRANS_USERSPACE | __TRANS_START | __TRANS_ATTACH | __TRANS_JOIN | __TRANS_JOIN_NOLOCK), } it is very intuitionistic. Besides that, because we remove ->in_commit in transaction structure, so the lock ->commit_lock which was used to protect it is unnecessary, remove ->commit_lock. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
* Btrfs: remove unnecessary varient ->num_joined in btrfs_transaction structureMiao Xie2013-06-141-2/+0
| | | | | | | | | | | | | | | | | We used ->num_joined track if there were some writers which join the current transaction when the committer was sleeping. If some writers joined the current transaction, we has to continue the while loop to do some necessary stuff, such as flush the ordered operations. But it is unnecessary because we will do it after the while loop. Besides that, tracking ->num_joined would make the committer drop into the while loop when there are lots of internal writers(TRANS_JOIN). So we remove ->num_joined and don't track if there are some writers which join the current transaction when the committer is sleeping. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
* Btrfs: don't wait for all the writers circularly during the transaction commitMiao Xie2013-06-141-8/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | btrfs_commit_transaction has the following loop before we commit the transaction. do { // attempt to do some useful stuff and/or sleep } while (atomic_read(&cur_trans->num_writers) > 1 || (should_grow && cur_trans->num_joined != joined)); This is used to prevent from the TRANS_START to get in the way of a committing transaction. But it does not prevent from TRANS_JOIN, that is we would do this loop for a long time if some writers JOIN the current transaction endlessly. Because we need join the current transaction to do some useful stuff, we can not block TRANS_JOIN here. So we introduce a external writer counter, which is used to count the TRANS_USERSPACE/TRANS_START writers. If the external writer counter is zero, we can break the above loop. In order to make the code more clear, we don't use enum variant to define the type of the transaction handle, use bitmask instead. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
* btrfs: make static code static & remove dead codeEric Sandeen2013-05-061-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Big patch, but all it does is add statics to functions which are in fact static, then remove the associated dead-code fallout. removed functions: btrfs_iref_to_path() __btrfs_lookup_delayed_deletion_item() __btrfs_search_delayed_insertion_item() __btrfs_search_delayed_deletion_item() find_eb_for_page() btrfs_find_block_group() range_straddles_pages() extent_range_uptodate() btrfs_file_extent_length() btrfs_scrub_cancel_devid() btrfs_start_transaction_lflush() btrfs_print_tree() is left because it is used for debugging. btrfs_start_transaction_lflush() and btrfs_reada_detach() are left for symmetry. ulist.c functions are left, another patch will take care of those. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
* btrfs: clean snapshots one by oneDavid Sterba2013-05-061-1/+1
| | | | | | | | | | | | | | | | Each time pick one dead root from the list and let the caller know if it's needed to continue. This should improve responsiveness during umount and balance which at some point waits for cleaning all currently queued dead roots. A new dead root is added to the end of the list, so the snapshots disappear in the order of deletion. The snapshot cleaning work is now done only from the cleaner thread and the others wake it if needed. Signed-off-by: David Sterba <dsterba@suse.cz> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
* Btrfs: fix wrong reserved space in qgroup during snap/subv creationMiao Xie2013-02-281-0/+1
| | | | | | | | | | | | | | | | There are two problems in the space reservation of the snapshot/ subvolume creation. - don't reserve the space for the root item insertion - the space which is reserved in the qgroup is different with the free space reservation. we need reserve free space for 7 items, but in qgroup reservation, we need reserve space only for 3 items. So we implement new metadata reservation functions for the snapshot/subvolume creation. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
* Btrfs: remove unnecessary dget_parent/dput when creating the pending snapshotMiao Xie2013-02-281-0/+1
| | | | | | | | | | | | Since we have grabbed the parent inode at the beginning of the snapshot creation, and both sync and async snapshot creation release it after the pending snapshots are actually created, it is safe to access the parent inode directly during the snapshot creation, we needn't use dget_parent/dput to fix the parent dentry and get the dir inode. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
* Btrfs: fix uncompleted transactionMiao Xie2013-02-201-0/+2
| | | | | | | | | | | | | | | | | | | | | | | In some cases, we need commit the current transaction, but don't want to start a new one if there is no running transaction, so we introduce the function - btrfs_attach_transaction(), which can catch the current transaction, and return -ENOENT if there is no running transaction. But no running transaction doesn't mean the current transction completely, because we removed the running transaction before it completes. In some cases, it doesn't matter. But in some special cases, such as freeze fs, we hope the transaction is fully on disk, it will introduce some bugs, for example, we may feeze the fs and dump the data in the disk, if the transction doesn't complete, we would dump inconsistent data. So we need fix the above problem for those cases. We fixes this problem by introducing a function: btrfs_attach_transaction_barrier() if we hope all the transaction is fully on the disk, even they are not running, we can use this function. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
* Btrfs: place ordered operations on a per transaction listJosef Bacik2013-02-201-0/+1
| | | | | | | | | | | | | | | | | | 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>
* btrfs: remove cache only arguments from defrag pathEric Sandeen2013-02-201-1/+1
| | | | | | | | | 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>
* Btrfs: don't re-enter when allocating a chunkJosef Bacik2013-02-201-0/+1
| | | | | | | | | | | 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>
* Btrfs: improve the noflush reservationMiao Xie2012-12-111-1/+1
| | | | | | | | | | | | | | | | 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>
* Btrfs: fix orphan transaction on the freezed filesystemMiao Xie2012-10-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Btrfs: add a type field for the transaction handleMiao Xie2012-10-091-4/+11
| | | | | | | | 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>
* Btrfs: fix race in sync and freeze againJosef Bacik2012-10-041-0/+1
| | | | | | | | | | | | 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>
* Btrfs: delay block group item insertionJosef Bacik2012-10-011-0/+1
| | | | | | | | | | | | | | | 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>
* Btrfs: fix corrupted metadata in the snapshotMiao Xie2012-10-011-0/+2
| | | | | | | | | | | | | | | | 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>
* Btrfs: fix a bug in checking whether a inode is already in logLiu Bo2012-10-011-0/+1
| | | | | | | | | | | | | | | | | | | | | | This is based on Josef's "Btrfs: turbo charge fsync". The current btrfs checks if an inode is in log by comparing root's last_log_commit to inode's last_sub_trans[2]. But the problem is that this root->last_log_commit is shared among inodes. Say we have N inodes to be logged, after the first inode, root's last_log_commit is updated and the N-1 remained files will be skipped. This fixes the bug by keeping a local copy of root's last_log_commit inside each inode and this local copy will be maintained itself. [1]: we regard each log transaction as a subset of btrfs's transaction, i.e. sub_trans Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
* Merge branch 'qgroup' of git://git.jan-o-sch.net/btrfs-unstable into for-linusChris Mason2012-07-251-0/+11
|\ | | | | | | | | | | | | | | | | | | Conflicts: fs/btrfs/ioctl.c fs/btrfs/ioctl.h fs/btrfs/transaction.c fs/btrfs/transaction.h Signed-off-by: Chris Mason <chris.mason@fusionio.com>
| * Btrfs: add qgroup inheritanceArne Jansen2012-07-121-0/+1
| | | | | | | | | | | | | | | | | | | | When creating a subvolume or snapshot, it is necessary to initialize the qgroup account with a copy of some other (tracking) qgroup. This patch adds parameters to the ioctls to pass the information from which qgroup to inherit. Signed-off-by: Arne Jansen <sensille@gmx.net>
| * Btrfs: hooks to reserve qgroup spaceArne Jansen2012-07-121-0/+1
| | | | | | | | | | | | | | | | | | | | Like block reserves, reserve a small piece of space on each transaction start and for delalloc. These are the hooks that can actually return EDQUOT to the user. The amount of space reserved is tracked in the transaction handle. Signed-off-by: Arne Jansen <sensille@gmx.net>
| * Btrfs: qgroup implementation and prototypesArne Jansen2012-07-121-0/+3
| | | | | | | | | | Signed-off-by: Arne Jansen <sensille@gmx.net> Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
| * Btrfs: check the root passed to btrfs_end_transactionArne Jansen2012-07-101-0/+6
| | | | | | | | | | | | | | | | This patch only add a consistancy check to validate that the same root is passed to start_transaction and end_transaction. Subvolume quota depends on this. Signed-off-by: Arne Jansen <sensille@gmx.net>
* | Btrfs: change how we indicate we're adding csumsJosef Bacik2012-07-231-0/+1
|/ | | | | | | | | | | | | | | | | | | | | | | 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>
* btrfs: enhance transaction abort infrastructureJeff Mahoney2012-03-221-0/+3
| | | | Signed-off-by: Jeff Mahoney <jeffm@suse.com>
* Merge branch 'for-chris' ofChris Mason2011-05-281-21/+8
|\ | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/josef/btrfs-work into for-linus Conflicts: fs/btrfs/disk-io.c fs/btrfs/extent-tree.c fs/btrfs/free-space-cache.c fs/btrfs/inode.c fs/btrfs/transaction.c Signed-off-by: Chris Mason <chris.mason@oracle.com>
| * Btrfs: kill BTRFS_I(inode)->block_groupJosef Bacik2011-05-231-14/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | Originally this was going to be used as a way to give hints to the allocator, but frankly we can get much better hints elsewhere and it's not even used at all for anything usefull. In addition to be completely useless, when we initialize an inode we try and find a freeish block group to set as the inodes block group, and with a completely full 40gb fs this takes _forever_, so I imagine with say 1tb fs this is just unbearable. So just axe the thing altoghether, we don't need it and it saves us 8 bytes in the inode and saves us 500 microseconds per inode lookup in my testcase. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
| * Btrfs: kill trans_mutexJosef Bacik2011-05-231-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We use trans_mutex for lots of things, here's a basic list 1) To serialize trans_handles joining the currently running transaction 2) To make sure that no new trans handles are started while we are committing 3) To protect the dead_roots list and the transaction lists Really the serializing trans_handles joining is not too hard, and can really get bogged down in acquiring a reference to the transaction. So replace the trans_mutex with a trans_lock spinlock and use it to do the following 1) Protect fs_info->running_transaction. All trans handles have to do is check this, and then take a reference of the transaction and keep on going. 2) Protect the fs_info->trans_list. This doesn't get used too much, basically it just holds the current transactions, which will usually just be the currently committing transaction and the currently running transaction at most. 3) Protect the dead roots list. This is only ever processed by splicing the list so this is relatively simple. 4) Protect the fs_info->reloc_ctl stuff. This is very lightweight and was using the trans_mutex before, so this is a pretty straightforward change. 5) Protect fs_info->no_trans_join. Because we don't hold the trans_lock over the entirety of the commit we need to have a way to block new people from creating a new transaction while we're doing our work. So we set no_trans_join and in join_transaction we test to see if that is set, and if it is we do a wait_on_commit. 6) Make the transaction use count atomic so we don't need to take locks to modify it when we're dropping references. 7) Add a commit_lock to the transaction to make sure multiple people trying to commit the same transaction don't race and commit at the same time. 8) Make open_ioctl_trans an atomic so we don't have to take any locks for ioctl trans. I have tested this with xfstests, but obviously it is a pretty hairy change so lots of testing is greatly appreciated. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
| * Btrfs: if we've already started a trans handle, use that oneJosef Bacik2011-05-231-0/+2
| | | | | | | | | | | | | | | | | | | | | | We currently track trans handles in current->journal_info, but we don't actually use it. This patch fixes it. This will cover the case where we have multiple people starting transactions down the call chain. This keeps us from having to allocate a new handle and all of that, we just increase the use count of the current handle, save the old block_rsv, and return. I tested this with xfstests and it worked out fine. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
| * Btrfs: take away the num_items argument from btrfs_join_transactionJosef Bacik2011-05-231-6/+3
| | | | | | | | | | | | | | | | | | I keep forgetting that btrfs_join_transaction() just ignores the num_items argument, which leads me to sending pointless patches and looking stupid :). So just kill the num_items argument from btrfs_join_transaction and btrfs_start_ioctl_transaction, since neither of them use it. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
* | Merge branch 'cleanups' of git://repo.or.cz/linux-2.6/btrfs-unstable into ↵Chris Mason2011-05-221-3/+0
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | inode_numbers Conflicts: fs/btrfs/extent-tree.c fs/btrfs/free-space-cache.c fs/btrfs/inode.c fs/btrfs/tree-log.c Signed-off-by: Chris Mason <chris.mason@oracle.com>
| * | btrfs: remove unused function prototypesDavid Sterba2011-05-041-3/+0
| |/ | | | | | | | | | | function prototypes without a body Signed-off-by: David Sterba <dsterba@suse.cz>
* | btrfs: implement delayed inode items operationMiao Xie2011-05-211-0/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Changelog V5 -> V6: - Fix oom when the memory load is high, by storing the delayed nodes into the root's radix tree, and letting btrfs inodes go. Changelog V4 -> V5: - Fix the race on adding the delayed node to the inode, which is spotted by Chris Mason. - Merge Chris Mason's incremental patch into this patch. - Fix deadlock between readdir() and memory fault, which is reported by Itaru Kitayama. Changelog V3 -> V4: - Fix nested lock, which is reported by Itaru Kitayama, by updating space cache inode in time. Changelog V2 -> V3: - Fix the race between the delayed worker and the task which does delayed items balance, which is reported by Tsutomu Itoh. - Modify the patch address David Sterba's comment. - Fix the bug of the cpu recursion spinlock, reported by Chris Mason Changelog V1 -> V2: - break up the global rb-tree, use a list to manage the delayed nodes, which is created for every directory and file, and used to manage the delayed directory name index items and the delayed inode item. - introduce a worker to deal with the delayed nodes. Compare with Ext3/4, the performance of file creation and deletion on btrfs is very poor. the reason is that btrfs must do a lot of b+ tree insertions, such as inode item, directory name item, directory name index and so on. If we can do some delayed b+ tree insertion or deletion, we can improve the performance, so we made this patch which implemented delayed directory name index insertion/deletion and delayed inode update. Implementation: - introduce a delayed root object into the filesystem, that use two lists to manage the delayed nodes which are created for every file/directory. One is used to manage all the delayed nodes that have delayed items. And the other is used to manage the delayed nodes which is waiting to be dealt with by the work thread. - Every delayed node has two rb-tree, one is used to manage the directory name index which is going to be inserted into b+ tree, and the other is used to manage the directory name index which is going to be deleted from b+ tree. - introduce a worker to deal with the delayed operation. This worker is used to deal with the works of the delayed directory name index items insertion and deletion and the delayed inode update. When the delayed items is beyond the lower limit, we create works for some delayed nodes and insert them into the work queue of the worker, and then go back. When the delayed items is beyond the upper bound, we create works for all the delayed nodes that haven't been dealt with, and insert them into the work queue of the worker, and then wait for that the untreated items is below some threshold value. - When we want to insert a directory name index into b+ tree, we just add the information into the delayed inserting rb-tree. And then we check the number of the delayed items and do delayed items balance. (The balance policy is above.) - When we want to delete a directory name index from the b+ tree, we search it in the inserting rb-tree at first. If we look it up, just drop it. If not, add the key of it into the delayed deleting rb-tree. Similar to the delayed inserting rb-tree, we also check the number of the delayed items and do delayed items balance. (The same to inserting manipulation) - When we want to update the metadata of some inode, we cached the data of the inode into the delayed node. the worker will flush it into the b+ tree after dealing with the delayed insertion and deletion. - We will move the delayed node to the tail of the list after we access the delayed node, By this way, we can cache more delayed items and merge more inode updates. - If we want to commit transaction, we will deal with all the delayed node. - the delayed node will be freed when we free the btrfs inode. - Before we log the inode items, we commit all the directory name index items and the delayed inode update. I did a quick test by the benchmark tool[1] and found we can improve the performance of file creation by ~15%, and file deletion by ~20%. Before applying this patch: Create files: Total files: 50000 Total time: 1.096108 Average time: 0.000022 Delete files: Total files: 50000 Total time: 1.510403 Average time: 0.000030 After applying this patch: Create files: Total files: 50000 Total time: 0.932899 Average time: 0.000019 Delete files: Total files: 50000 Total time: 1.215732 Average time: 0.000024 [1] http://marc.info/?l=linux-btrfs&m=128212635122920&q=p3 Many thanks for Kitayama-san's help! Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Reviewed-by: David Sterba <dave@jikos.cz> Tested-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Tested-by: Itaru Kitayama <kitayama@cl.bb4u.ne.jp> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: avoid taking the trans_mutex in btrfs_end_transactionJosef Bacik2011-04-111-2/+2
| | | | | | | | | | | I've been working on making our O_DIRECT latency not suck and I noticed we were taking the trans_mutex in btrfs_end_transaction. So to do this we convert num_writers and use_count to atomic_t's and just decrement them in btrfs_end_transaction. Instead of deleting the transaction from the trans list in put_transaction we do that in btrfs_commit_transaction() since that's the only time it actually needs to be removed from the list. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
* Btrfs: Add readonly snapshots supportLi Zefan2010-12-231-0/+1
| | | | | | | | | | | | | | | | | | | | Usage: Set BTRFS_SUBVOL_RDONLY of btrfs_ioctl_vol_arg_v2->flags, and call ioctl(BTRFS_I0CTL_SNAP_CREATE_V2). Implementation: - Set readonly bit of btrfs_root_item->flags. - Add readonly checks in btrfs_permission (inode_permission), btrfs_setattr, btrfs_set/remove_xattr and some ioctls. Changelog for v3: - Eliminate btrfs_root->readonly, but check btrfs_root->root_item.flags. - Rename BTRFS_ROOT_SNAP_RDONLY to BTRFS_ROOT_SUBVOL_RDONLY. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
* Btrfs: add START_SYNC, WAIT_SYNC ioctlsSage Weil2010-10-291-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | START_SYNC will start a sync/commit, but not wait for it to complete. Any modification started after the ioctl returns is guaranteed not to be included in the commit. If a non-NULL pointer is passed, the transaction id will be returned to userspace. WAIT_SYNC will wait for any in-progress commit to complete. If a transaction id is specified, the ioctl will block and then return (success) when the specified transaction has committed. If it has already committed when we call the ioctl, it returns immediately. If the specified transaction doesn't exist, it returns EINVAL. If no transaction id is specified, WAIT_SYNC will wait for the currently committing transaction to finish it's commit to disk. If there is no currently committing transaction, it returns success. These ioctls are useful for applications which want to impose an ordering on when fs modifications reach disk, but do not want to wait for the full (slow) commit process to do so. Picky callers can take the transid returned by START_SYNC and feed it to WAIT_SYNC, and be certain to wait only as long as necessary for the transaction _they_ started to reach disk. Sloppy callers can START_SYNC and WAIT_SYNC without a transid, and provided they didn't wait too long between the calls, they will get the same result. However, if a second commit starts before they call WAIT_SYNC, they may end up waiting longer for it to commit as well. Even so, a START_SYNC+WAIT_SYNC still guarantees that any operation completed before the START_SYNC reaches disk. Signed-off-by: Sage Weil <sage@newdream.net> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: async transaction commitSage Weil2010-10-291-0/+3
| | | | | | | | | | | | | | | | Add support for an async transaction commit that is ordered such that any subsequent operations will join the following transaction, but does not wait until the current commit is fully on disk. This avoids much of the latency associated with the btrfs_commit_transaction for callers concerned with serialization and not safety. The wait_for_unblock flag controls whether we wait for the 'middle' portion of commit_transaction to complete, which is necessary if the caller expects some of the modifications contained in the commit to be available (this is the case for subvol/snapshot creation). Signed-off-by: Sage Weil <sage@newdream.net> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: create special free space cache inodeJosef Bacik2010-10-281-0/+4
| | | | | | | | | | | | | | | In order to save free space cache, we need an inode to hold the data, and we need a special item to point at the right inode for the right block group. So first, create a special item that will point to the right inode, and the number of extent entries we will have and the number of bitmaps we will have. We truncate and pre-allocate space everytime to make sure it's uptodate. This feature will be turned on as soon as you mount with -o space_cache, however it is safe to boot into old kernels, they will just generate the cache the old fashion way. When you boot back into a newer kernel we will notice that we modified and not the cache and automatically discard the cache. Signed-off-by: Josef Bacik <josef@redhat.com>
* Btrfs: Introduce global metadata reservationYan, Zheng2010-05-251-0/+3
| | | | | | | Reserve metadata space for extent tree, checksum tree and root tree Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Integrate metadata reservation with start_transactionYan, Zheng2010-05-251-5/+8
| | | | | | | | | | | | | | | Besides simplify the code, this change makes sure all metadata reservation for normal metadata operations are released after committing transaction. Changes since V1: Add code that check if unlink and rmdir will free space. Add ENOSPC handling for clone ioctl. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Introduce contexts for metadata reservationYan, Zheng2010-05-251-4/+4
| | | | | | | | | | | | | | | | | | Introducing metadata reseravtion contexts has two major advantages. First, it makes metadata reseravtion more traceable. Second, it can reclaim freed space and re-add them to the itself after transaction committed. Besides add btrfs_block_rsv structure and related helper functions, This patch contains following changes: Move code that decides if freed tree block should be pinned into btrfs_free_tree_block(). Make space accounting more accurate, mainly for handling read only block groups. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Avoid superfluous tree-log writeoutYan, Zheng2009-12-151-3/+3
| | | | | | | | | | | We allow two log transactions at a time, but use same flag to mark dirty tree-log btree blocks. So we may flush dirty blocks belonging to newer log transaction when committing a log transaction. This patch fixes the issue by using two flags to mark dirty tree-log btree blocks. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: streamline tree-log btree block writeoutChris Mason2009-10-131-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | Syncing the tree log is a 3 phase operation. 1) write and wait for all the tree log blocks for a given root. 2) write and wait for all the tree log blocks for the tree of tree log roots. 3) write and wait for the super blocks (barriers here) This isn't as efficient as it could be because there is no requirement to wait for the blocks from step one to hit the disk before we start writing the blocks from step two. This commit changes the sequence so that we don't start waiting until all the tree blocks from both steps one and two have been sent to disk. We do this by breaking up btrfs_write_wait_marked_extents into two functions, which is trivial because it was already broken up into two parts. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: avoid tree log commit when there are no changesChris Mason2009-10-131-0/+1
| | | | | | | | | | | | | | | | | | rpm has a habit of running fdatasync when the file hasn't changed. We already detect if a file hasn't been changed in the current transaction but it might have been sent to the tree-log in this transaction and not changed since the last call to fsync. In this case, we want to avoid a tree log sync, which includes a number of synchronous writes and barriers. This commit extends the existing tracking of the last transaction to change a file to also track the last sub-transaction. The end result is that rpm -ivh and -Uvh are roughly twice as fast, and on par with ext3. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: be more polite in the async caching threadsChris Mason2009-07-301-0/+1
| | | | | | | | | The semaphore used by the async caching threads can prevent a transaction commit, which can make the FS appear to stall. This releases the semaphore more often when a transaction commit is in progress. Signed-off-by: Chris Mason <chris.mason@oracle.com>
OpenPOWER on IntegriCloud