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2015-06-30Merge branch 'for-linus-4.2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs updates from Chris Mason: "Outside of our usual batch of fixes, this integrates the subvolume quota updates that Qu Wenruo from Fujitsu has been working on for a few releases now. He gets an extra gold star for making btrfs smaller this time, and fixing a number of quota corners in the process. Dave Sterba tested and integrated Anand Jain's sysfs improvements. Outside of exporting a symbol (ack'd by Greg) these are all internal to btrfs and it's mostly cleanups and fixes. Anand also attached some of our sysfs objects to our internal device management structs instead of an object off the super block. It will make device management easier overall and it's a better fit for how the sysfs files are used. None of the existing sysfs files are moved around. Thanks for all the fixes everyone" * 'for-linus-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (87 commits) btrfs: delayed-ref: double free in btrfs_add_delayed_tree_ref() Btrfs: Check if kobject is initialized before put lib: export symbol kobject_move() Btrfs: sysfs: add support to show replacing target in the sysfs Btrfs: free the stale device Btrfs: use received_uuid of parent during send Btrfs: fix use-after-free in btrfs_replay_log btrfs: wait for delayed iputs on no space btrfs: qgroup: Make snapshot accounting work with new extent-oriented qgroup. btrfs: qgroup: Add the ability to skip given qgroup for old/new_roots. btrfs: ulist: Add ulist_del() function. btrfs: qgroup: Cleanup the old ref_node-oriented mechanism. btrfs: qgroup: Switch self test to extent-oriented qgroup mechanism. btrfs: qgroup: Switch to new extent-oriented qgroup mechanism. btrfs: qgroup: Switch rescan to new mechanism. btrfs: qgroup: Add new qgroup calculation function btrfs_qgroup_account_extents(). btrfs: backref: Add special time_seq == (u64)-1 case for btrfs_find_all_roots(). btrfs: qgroup: Add new function to record old_roots. btrfs: qgroup: Record possible quota-related extent for qgroup. btrfs: qgroup: Add function qgroup_update_counters(). ...
2015-06-25Merge branch 'for-4.2/core' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull core block IO update from Jens Axboe: "Nothing really major in here, mostly a collection of smaller optimizations and cleanups, mixed with various fixes. In more detail, this contains: - Addition of policy specific data to blkcg for block cgroups. From Arianna Avanzini. - Various cleanups around command types from Christoph. - Cleanup of the suspend block I/O path from Christoph. - Plugging updates from Shaohua and Jeff Moyer, for blk-mq. - Eliminating atomic inc/dec of both remaining IO count and reference count in a bio. From me. - Fixes for SG gap and chunk size support for data-less (discards) IO, so we can merge these better. From me. - Small restructuring of blk-mq shared tag support, freeing drivers from iterating hardware queues. From Keith Busch. - A few cfq-iosched tweaks, from Tahsin Erdogan and me. Makes the IOPS mode the default for non-rotational storage" * 'for-4.2/core' of git://git.kernel.dk/linux-block: (35 commits) cfq-iosched: fix other locations where blkcg_to_cfqgd() can return NULL cfq-iosched: fix sysfs oops when attempting to read unconfigured weights cfq-iosched: move group scheduling functions under ifdef cfq-iosched: fix the setting of IOPS mode on SSDs blktrace: Add blktrace.c to BLOCK LAYER in MAINTAINERS file block, cgroup: implement policy-specific per-blkcg data block: Make CFQ default to IOPS mode on SSDs block: add blk_set_queue_dying() to blkdev.h blk-mq: Shared tag enhancements block: don't honor chunk sizes for data-less IO block: only honor SG gap prevention for merges that contain data block: fix returnvar.cocci warnings block, dm: don't copy bios for request clones block: remove management of bi_remaining when restoring original bi_end_io block: replace trylock with mutex_lock in blkdev_reread_part() block: export blkdev_reread_part() and __blkdev_reread_part() suspend: simplify block I/O handling block: collapse bio bit space block: remove unused BIO_RW_BLOCK and BIO_EOF flags block: remove BIO_EOPNOTSUPP ...
2015-06-24btrfs: delayed-ref: double free in btrfs_add_delayed_tree_ref()Dan Carpenter
There is a cut and paste error so instead of freeing "head_ref", we free "ref" twice. Fixes: 3368d001ba5d ('btrfs: qgroup: Record possible quota-related extent for qgroup.') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-23Merge branch 'sysfs-fsdevices-4.2-part1' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into anand
2015-06-22Btrfs: Check if kobject is initialized before putAnand Jain
Signed-off-by: Anand Jain <anand.jain@oracle.com> Tested-by: David Sterba <dsterba@suse.cz> Signed-off-by: David Sterba <dsterba@suse.cz>
2015-06-19Btrfs: sysfs: add support to show replacing target in the sysfsAnand Jain
This patch will add support to show the replacing target in sysfs during the process of replacement. Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.cz>
2015-06-19Btrfs: free the stale deviceAnand Jain
When btrfs on a device is overwritten with a new btrfs (mkfs), the old btrfs instance in the kernel becomes stale. So with this patch, if kernel finds device is overwritten then delete the stale fsid/uuid. Signed-off-by: Anand Jain <anand.jain@oracle.com>
2015-06-12Btrfs: use received_uuid of parent during sendJosef Bacik
Neil Horman pointed out a problem where if he did something like this receive A snap A B change B send -p A B and then on another box do recieve A receive B the receive B would fail because we use the UUID of A for the clone sources for B. This makes sense most of the time because normally you are sending from the original sources, not a received source. However when you use a recieved subvol its UUID is going to be something completely different, so if you then try to receive the diff on a different volume it won't find the UUID because the new A will be something else. The only constant is the received uuid. So instead check to see if we have received_uuid set on the root, and if so use that as the clone source, as btrfs receive looks for matches either in received_uuid or uuid. Thanks, Reported-by: Neil Horman <nhorman@redhat.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Hugo Mills <hugo@carfax.org.uk> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-12Btrfs: fix use-after-free in btrfs_replay_logLiu Bo
@log_root_tree should not be referenced after kfree. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.cz> Reported-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10btrfs: wait for delayed iputs on no spaceZhao Lei
btrfs will report no_space when we run following write and delete file loop: # FILE_SIZE_M=[ 75% of fs space ] # DEV=[ some dev ] # MNT=[ some dir ] # # mkfs.btrfs -f "$DEV" # mount -o nodatacow "$DEV" "$MNT" # for ((i = 0; i < 100; i++)); do dd if=/dev/zero of="$MNT"/file0 bs=1M count="$FILE_SIZE_M"; rm -f "$MNT"/file0; done # Reason: iput() and evict() is run after write pages to block device, if write pages work is not finished before next write, the "rm"ed space is not freed, and caused above bug. Fix: We can add "-o flushoncommit" mount option to avoid above bug, but it have performance problem. Actually, we can to wait for on-the-fly writes only when no-space happened, it is which this patch do. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10btrfs: qgroup: Make snapshot accounting work with new extent-orientedQu Wenruo
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>
2015-06-10btrfs: qgroup: Add the ability to skip given qgroup for old/new_roots.Qu Wenruo
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>
2015-06-10btrfs: ulist: Add ulist_del() function.Qu Wenruo
This function will delete unode with given (val,aux) pair. And with this patch, seqnum for debug usage doesn't have any meaning now, so remove them. This is used by later patches to skip snapshot root. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10btrfs: qgroup: Cleanup the old ref_node-oriented mechanism.Qu Wenruo
Goodbye, the old mechanisim. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10btrfs: qgroup: Switch self test to extent-oriented qgroup mechanism.Qu Wenruo
Since the self test transaction don't have delayed_ref_roots, so use find_all_roots() and export btrfs_qgroup_account_extent() to simulate it Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10btrfs: qgroup: Switch to new extent-oriented qgroup mechanism.Qu Wenruo
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>
2015-06-10btrfs: qgroup: Switch rescan to new mechanism.Qu Wenruo
Switch rescan to use the new new extent oriented mechanism. As rescan is also based on extent, new mechanism is just a perfect match for rescan. With re-designed internal functions, rescan is quite easy, just call btrfs_find_all_roots() and then btrfs_qgroup_account_one_extent(). Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10btrfs: qgroup: Add new qgroup calculation functionQu Wenruo
btrfs_qgroup_account_extents(). The new btrfs_qgroup_account_extents() function should be called in btrfs_commit_transaction() and it will update all the qgroup according to delayed_ref_root->dirty_extent_root. The new function can handle both normal operation during commit_transaction() or in rescan in a unified method with clearer logic. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10btrfs: backref: Add special time_seq == (u64)-1 case forQu Wenruo
btrfs_find_all_roots(). Allow btrfs_find_all_roots() to skip all delayed_ref_head lock and tree lock to do tree search. This is important for later qgroup implement which will call find_all_roots() after fs trees are committed. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10btrfs: qgroup: Add new function to record old_roots.Qu Wenruo
Add function btrfs_qgroup_prepare_account_extents() to get old_roots which are needed for qgroup. We do it in commit_transaction() and before switch_roots(), and only search commit_root, so it gives a quite accurate view for previous transaction. With old_roots from previous transaction, we can use it to do accurate account with current transaction. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10btrfs: qgroup: Record possible quota-related extent for qgroup.Qu Wenruo
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>
2015-06-10btrfs: qgroup: Add function qgroup_update_counters().Qu Wenruo
Add function qgroup_update_counters(), which will update related qgroups' rfer/excl according to old/new_roots. This is one of the two core functions for the new qgroup implement. This is based on btrfs_adjust_coutners() but with clearer logic and comment. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10btrfs: qgroup: Add function qgroup_update_refcnt().Qu Wenruo
This function is used to update refcnt for qgroups. And is one of the two core functions used in the new qgroup implement. This is based on the old update_old/new_refcnt, but provides a unified logic and behavior. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10btrfs: extent-tree: Use ref_node to replace unneeded parameters in ↵Qu Wenruo
__inc_extent_ref() and __free_extent() __btrfs_inc_extent_ref() and __btrfs_free_extent() have already had too many parameters, but three of them can be extracted from btrfs_delayed_ref_node struct. So use btrfs_delayed_ref_node struct as a single parameter to replace the bytenr/num_byte/no_quota parameters. The real objective of this patch is to allow btrfs_qgroup_record_ref() get the delayed_ref_node in incoming qgroup patches. Other functions calling btrfs_qgroup_record_ref() are not affected since the rest will only add/sub exclusive extents, where node is not used. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10btrfs: qgroup: Cleanup open-coded old/new_refcnt update and read.Qu Wenruo
Use inline functions to do such things, to improve readability. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Acked-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10btrfs: delayed-ref: Cleanup the unneeded functions.Qu Wenruo
Cleanup the rb_tree merge/insert/update functions, since now we use list instead of rb_tree now. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10btrfs: delayed-ref: Use list to replace the ref_root in ref_head.Qu Wenruo
This patch replace the rbtree used in ref_head to list. This has the following advantage: 1) Easier merge logic. With the new list implement, we only need to care merging the tail ref_node with the new ref_node. And this can be done quite easy at insert time, no need to do a indicated merge at run_delayed_refs(). Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10btrfs: backref: Don't merge refs which are not for same block.Qu Wenruo
Old __merge_refs() in backref.c will even merge refs whose root_id are different, which makes qgroup gives wrong result. Fix it by checking ref_for_same_block() before any mode specific works. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10btrfs: Fix lockdep warning of wr_ctx->wr_lock in scrub_free_wr_ctx()Zhao Lei
lockdep report following warning in test: [25176.843958] ================================= [25176.844519] [ INFO: inconsistent lock state ] [25176.845047] 4.1.0-rc3 #22 Tainted: G W [25176.845591] --------------------------------- [25176.846153] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. [25176.846713] fsstress/26661 [HC0[0]:SC1[1]:HE1:SE0] takes: [25176.847246] (&wr_ctx->wr_lock){+.?...}, at: [<ffffffffa04cdc6d>] scrub_free_ctx+0x2d/0xf0 [btrfs] [25176.847838] {SOFTIRQ-ON-W} state was registered at: [25176.848396] [<ffffffff810bf460>] __lock_acquire+0x6a0/0xe10 [25176.848955] [<ffffffff810bfd1e>] lock_acquire+0xce/0x2c0 [25176.849491] [<ffffffff816489af>] mutex_lock_nested+0x7f/0x410 [25176.850029] [<ffffffffa04d04ff>] scrub_stripe+0x4df/0x1080 [btrfs] [25176.850575] [<ffffffffa04d11b1>] scrub_chunk.isra.19+0x111/0x130 [btrfs] [25176.851110] [<ffffffffa04d144c>] scrub_enumerate_chunks+0x27c/0x510 [btrfs] [25176.851660] [<ffffffffa04d3b87>] btrfs_scrub_dev+0x1c7/0x6c0 [btrfs] [25176.852189] [<ffffffffa04e918e>] btrfs_dev_replace_start+0x36e/0x450 [btrfs] [25176.852771] [<ffffffffa04a98e0>] btrfs_ioctl+0x1e10/0x2d20 [btrfs] [25176.853315] [<ffffffff8121c5b8>] do_vfs_ioctl+0x318/0x570 [25176.853868] [<ffffffff8121c851>] SyS_ioctl+0x41/0x80 [25176.854406] [<ffffffff8164da17>] system_call_fastpath+0x12/0x6f [25176.854935] irq event stamp: 51506 [25176.855511] hardirqs last enabled at (51506): [<ffffffff810d4ce5>] vprintk_emit+0x225/0x5e0 [25176.856059] hardirqs last disabled at (51505): [<ffffffff810d4b77>] vprintk_emit+0xb7/0x5e0 [25176.856642] softirqs last enabled at (50886): [<ffffffff81067a23>] __do_softirq+0x363/0x640 [25176.857184] softirqs last disabled at (50949): [<ffffffff8106804d>] irq_exit+0x10d/0x120 [25176.857746] other info that might help us debug this: [25176.858845] Possible unsafe locking scenario: [25176.859981] CPU0 [25176.860537] ---- [25176.861059] lock(&wr_ctx->wr_lock); [25176.861705] <Interrupt> [25176.862272] lock(&wr_ctx->wr_lock); [25176.862881] *** DEADLOCK *** Reason: Above warning is caused by: Interrupt -> bio_endio() -> ... -> scrub_put_ctx() -> scrub_free_ctx() *1 -> ... -> mutex_lock(&wr_ctx->wr_lock); scrub_put_ctx() is allowed to be called in end_bio interrupt, but in code design, it will never call scrub_free_ctx(sctx) in interrupe context(above *1), because btrfs_scrub_dev() get one additional reference of sctx->refs, which makes scrub_free_ctx() only called withine btrfs_scrub_dev(). Now the code runs out of our wish, because free sequence in scrub_pending_bio_dec() have a gap. Current code: -----------------------------------+----------------------------------- scrub_pending_bio_dec() | btrfs_scrub_dev -----------------------------------+----------------------------------- atomic_dec(&sctx->bios_in_flight); | wake_up(&sctx->list_wait); | | scrub_put_ctx() | -> atomic_dec_and_test(&sctx->refs) scrub_put_ctx(sctx); | -> atomic_dec_and_test(&sctx->refs)| -> scrub_free_ctx() | -----------------------------------+----------------------------------- We expected: -----------------------------------+----------------------------------- scrub_pending_bio_dec() | btrfs_scrub_dev -----------------------------------+----------------------------------- atomic_dec(&sctx->bios_in_flight); | wake_up(&sctx->list_wait); | scrub_put_ctx(sctx); | -> atomic_dec_and_test(&sctx->refs)| | scrub_put_ctx() | -> atomic_dec_and_test(&sctx->refs) | -> scrub_free_ctx() -----------------------------------+----------------------------------- Fix: Move scrub_pending_bio_dec() to a workqueue, to avoid this function run in interrupt context. Tested by check tracelog in debug. Changelog v1->v2: Use workqueue instead of adjust function call sequence in v1, because v1 will introduce a bug pointed out by: Filipe David Manana <fdmanana@gmail.com> Reported-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10btrfs: Handle unaligned length in extent_sameMark Fasheh
The extent-same code rejects requests with an unaligned length. This poses a problem when we want to dedupe the tail extent of files as we skip cloning the portion between i_size and the extent boundary. If we don't clone the entire extent, it won't be deleted. So the combination of these behaviors winds up giving us worst-case dedupe on many files. We can fix this by allowing a length that extents to i_size and internally aligining those to the end of the block. This is what btrfs_ioctl_clone() so we can just copy that check over. Signed-off-by: Mark Fasheh <mfasheh@suse.de> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10Btrfs: btrfs_defrag_file: Fix calculation of max_to_defrag.chandan
max_to_defrag represents the number of pages to defrag rather than the last page of the file range to be defragged. Consider a file having 10 4k blocks (i.e. blocks in the range [0 - 9]). If the defrag ioctl was invoked for the block range [3 - 6], then max_to_defrag should actually have the value 4. Instead in the current code we end up setting it to 6. Now, this does not (yet) cause an issue since the first part of the while loop condition in btrfs_defrag_file() (i.e. "i <= last_index") causes the control to flow out of the while loop before any buggy behavior is actually caused. So the patch just makes sure that max_to_defrag ends up having the right value rather than fixing a bug. I did run the xfstests suite to make sure that the code does not regress. Changelog: v1->v2: Provide a much descriptive commit message. Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10Btrfs: btrfs_defrag_file: Fix ra_index computation.chandan
Read-ahead is done for the pages in the range [ra_index, ra_index + cluster - 1]. So the next read-ahead should be starting from the page at index 'ra_index + cluster' (unless we deemed that the extent at 'ra_index + cluster' as non-defraggable) rather than from the page at index 'ra_index + max_cluster'. This patch fixes this. I did run the xfstests suite to make sure that the code does not regress. Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10Btrfs: fix necessary chunk tree space calculation when allocating a chunkFilipe Manana
When allocating a new chunk or removing one we need to update num_devs device items and insert or remove a chunk item in the chunk tree, so in the worst case the space needed in the chunk space_info is: btrfs_calc_trunc_metadata_size(chunk_root, num_devs) + btrfs_calc_trans_metadata_size(chunk_root, 1) That is, in the worst case we need to cow num_devs paths and cow 1 other path that can result in splitting every node and leaf, and each path consisting of BTRFS_MAX_LEVEL - 1 nodes and 1 leaf. We were requiring some additional chunk_root->nodesize * BTRFS_MAX_LEVEL * num_devs bytes, which were unnecessary since updating the existing device items does not result in splitting the nodes and leaf since after updating them they remain with the same size. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10Btrfs: don't attach unnecessary extents to transaction on fsyncFilipe Manana
We don't need to attach ordered extents that have completed to the current transaction. Doing so only makes us hold memory for longer than necessary and delaying the iput of the inode until the transaction is committed (for each created ordered extent we do an igrab and then schedule an asynchronous iput when the ordered extent's reference count drops to 0), preventing the inode from being evictable until the transaction commits. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10Btrfs: avoid syncing log in the fast fsync path when not necessaryFilipe Manana
Commit 3a8b36f37806 ("Btrfs: fix data loss in the fast fsync path") added a performance regression for that causes an unnecessary sync of the log trees (fs/subvol and root log trees) when 2 consecutive fsyncs are done against a file, without no writes or any metadata updates to the inode in between them and if a transaction is committed before the second fsync is called. Huang Ying reported this to lkml (https://lkml.org/lkml/2015/3/18/99) after a test sysbench test that measured a -62% decrease of file io requests per second for that tests' workload. The test is: echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor echo performance > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor echo performance > /sys/devices/system/cpu/cpu2/cpufreq/scaling_governor echo performance > /sys/devices/system/cpu/cpu3/cpufreq/scaling_governor mkfs -t btrfs /dev/sda2 mount -t btrfs /dev/sda2 /fs/sda2 cd /fs/sda2 for ((i = 0; i < 1024; i++)); do fallocate -l 67108864 testfile.$i; done sysbench --test=fileio --max-requests=0 --num-threads=4 --max-time=600 \ --file-test-mode=rndwr --file-total-size=68719476736 --file-io-mode=sync \ --file-num=1024 run A test on kvm guest, running a debug kernel gave me the following results: Without 3a8b36f378060d: 16.01 reqs/sec With 3a8b36f378060d: 3.39 reqs/sec With 3a8b36f378060d and this patch: 16.04 reqs/sec Reported-by: Huang Ying <ying.huang@intel.com> Tested-by: Huang, Ying <ying.huang@intel.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10Merge branch 'send_fixes_4.2' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/fdmanana/linux into for-linus-4.2
2015-06-03Btrfs: fix hang during inode eviction due to concurrent readaheadFilipe Manana
Zygo Blaxell and other users have reported occasional hangs while an inode is being evicted, leading to traces like the following: [ 5281.972322] INFO: task rm:20488 blocked for more than 120 seconds. [ 5281.973836] Not tainted 4.0.0-rc5-btrfs-next-9+ #2 [ 5281.974818] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 5281.976364] rm D ffff8800724cfc38 0 20488 7747 0x00000000 [ 5281.977506] ffff8800724cfc38 ffff8800724cfc38 ffff880065da5c50 0000000000000001 [ 5281.978461] ffff8800724cffd8 ffff8801540a5f50 0000000000000008 ffff8801540a5f78 [ 5281.979541] ffff8801540a5f50 ffff8800724cfc58 ffffffff8143107e 0000000000000123 [ 5281.981396] Call Trace: [ 5281.982066] [<ffffffff8143107e>] schedule+0x74/0x83 [ 5281.983341] [<ffffffffa03b33cf>] wait_on_state+0xac/0xcd [btrfs] [ 5281.985127] [<ffffffff81075cd6>] ? signal_pending_state+0x31/0x31 [ 5281.986715] [<ffffffffa03b4b71>] wait_extent_bit.constprop.32+0x7c/0xde [btrfs] [ 5281.988680] [<ffffffffa03b540b>] lock_extent_bits+0x5d/0x88 [btrfs] [ 5281.990200] [<ffffffffa03a621d>] btrfs_evict_inode+0x24e/0x5be [btrfs] [ 5281.991781] [<ffffffff8116964d>] evict+0xa0/0x148 [ 5281.992735] [<ffffffff8116a43d>] iput+0x18f/0x1e5 [ 5281.993796] [<ffffffff81160d4a>] do_unlinkat+0x15b/0x1fa [ 5281.994806] [<ffffffff81435b54>] ? ret_from_sys_call+0x1d/0x58 [ 5281.996120] [<ffffffff8107d314>] ? trace_hardirqs_on_caller+0x18f/0x1ab [ 5281.997562] [<ffffffff8123960b>] ? trace_hardirqs_on_thunk+0x3a/0x3f [ 5281.998815] [<ffffffff81161a16>] SyS_unlinkat+0x29/0x2b [ 5281.999920] [<ffffffff81435b32>] system_call_fastpath+0x12/0x17 [ 5282.001299] 1 lock held by rm/20488: [ 5282.002066] #0: (sb_writers#12){.+.+.+}, at: [<ffffffff8116dd81>] mnt_want_write+0x24/0x4b This happens when we have readahead, which calls readpages(), happening right before the inode eviction handler is invoked. So the reason is essentially: 1) readpages() is called while a reference on the inode is held, so eviction can not be triggered before readpages() returns. It also locks one or more ranges in the inode's io_tree (which is done at extent_io.c:__do_contiguous_readpages()); 2) readpages() submits several read bios, all with an end io callback that runs extent_io.c:end_bio_extent_readpage() and that is executed by other task when a bio finishes, corresponding to a work queue (fs_info->end_io_workers) worker kthread. This callback unlocks the ranges in the inode's io_tree that were previously locked in step 1; 3) readpages() returns, the reference on the inode is dropped; 4) One or more of the read bios previously submitted are still not complete (their end io callback was not yet invoked or has not yet finished execution); 5) Inode eviction is triggered (through an unlink call for example). The inode reference count was not incremented before submitting the read bios, therefore this is possible; 6) The eviction handler starts executing and enters the loop that iterates over all extent states in the inode's io_tree; 7) The loop picks one extent state record and uses its ->start and ->end fields, after releasing the inode's io_tree spinlock, to call lock_extent_bits() and clear_extent_bit(). The call to lock the range [state->start, state->end] blocks because the whole range or a part of it was locked by the previous call to readpages() and the corresponding end io callback, which unlocks the range was not yet executed; 8) The end io callback for the read bio is executed and unlocks the range [state->start, state->end] (or a superset of that range). And at clear_extent_bit() the extent_state record state is used as a second argument to split_state(), which sets state->start to a larger value; 9) The task executing the eviction handler is woken up by the task executing the bio's end io callback (through clear_state_bit) and the eviction handler locks the range [old value for state->start, state->end]. Shortly after, when calling clear_extent_bit(), it unlocks the range [new value for state->start, state->end], so it ends up unlocking only part of the range that it locked, leaving an extent state record in the io_tree that represents the unlocked subrange; 10) The eviction handler loop, in its next iteration, gets the extent_state record for the subrange that it did not unlock in the previous step and then tries to lock it, resulting in an hang. So fix this by not using the ->start and ->end fields of an existing extent_state record. This is a simple solution, and an alternative could be to bump the inode's reference count before submitting each read bio and having it dropped in the bio's end io callback. But that would be a more invasive/complex change and would not protect against other possible places that are not holding a reference on the inode as well. Something to consider in the future. Many thanks to Zygo Blaxell for reporting, in the mailing list, the issue, a set of scripts to trigger it and testing this fix. Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Tested-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-03Btrfs: fix up read_tree_block to return proper errorLiu Bo
The return value of read_tree_block() can confuse callers as it always returns NULL for either -ENOMEM or -EIO, so it's likely that callers parse it to a wrong error, for instance, in btrfs_read_tree_root(). This fixes the above issue. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-03Btrfs: add missing free_extent_bufferLiu Bo
read_tree_block may take a reference on the 'eb', a following free_extent_buffer is necessary. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-03Btrfs: remove csum_bytes_leftLiu Bo
After commit 8407f553268a ("Btrfs: fix data corruption after fast fsync and writeback error"), during wait_ordered_extents(), we wait for ordered extent setting BTRFS_ORDERED_IO_DONE or BTRFS_ORDERED_IOERR, at which point we've already got checksum information, so we don't need to check (csum_bytes_left == 0) in the whole logging path. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-03Btrfs: fix -ENOSPC on block group removalFilipe Manana
Unlike when attempting to allocate a new block group, where we check that we have enough space in the system space_info to update the device items and insert a new chunk item in the chunk tree, we were not checking if the system space_info had enough space for updating the device items and deleting the chunk item in the chunk tree. This often lead to -ENOSPC error when attempting to allocate blocks for the chunk tree (during btree node/leaf COW operations) while updating the device items or deleting the chunk item, which resulted in the current transaction being aborted and turning the filesystem into read-only mode. While running fstests generic/038, which stresses allocation of block groups and removal of unused block groups, with a large scratch device (750Gb) this happened often, despite more than enough unallocated space, and resulted in the following trace: [68663.586604] WARNING: CPU: 3 PID: 1521 at fs/btrfs/super.c:260 __btrfs_abort_transaction+0x52/0x114 [btrfs]() [68663.600407] BTRFS: Transaction aborted (error -28) (...) [68663.730829] Call Trace: [68663.732585] [<ffffffff8142fa46>] dump_stack+0x4f/0x7b [68663.734334] [<ffffffff8108b6a2>] ? console_unlock+0x361/0x3ad [68663.739980] [<ffffffff81045ea5>] warn_slowpath_common+0xa1/0xbb [68663.757153] [<ffffffffa036ca6d>] ? __btrfs_abort_transaction+0x52/0x114 [btrfs] [68663.760925] [<ffffffff81045f05>] warn_slowpath_fmt+0x46/0x48 [68663.762854] [<ffffffffa03b159d>] ? btrfs_update_device+0x15a/0x16c [btrfs] [68663.764073] [<ffffffffa036ca6d>] __btrfs_abort_transaction+0x52/0x114 [btrfs] [68663.765130] [<ffffffffa03b3638>] btrfs_remove_chunk+0x597/0x5ee [btrfs] [68663.765998] [<ffffffffa0384663>] ? btrfs_delete_unused_bgs+0x245/0x296 [btrfs] [68663.767068] [<ffffffffa0384676>] btrfs_delete_unused_bgs+0x258/0x296 [btrfs] [68663.768227] [<ffffffff8143527f>] ? _raw_spin_unlock_irq+0x2d/0x4c [68663.769081] [<ffffffffa038b109>] cleaner_kthread+0x13d/0x16c [btrfs] [68663.799485] [<ffffffffa038afcc>] ? btrfs_alloc_root+0x28/0x28 [btrfs] [68663.809208] [<ffffffff8105f367>] kthread+0xef/0xf7 [68663.828795] [<ffffffff810e603f>] ? time_hardirqs_on+0x15/0x28 [68663.844942] [<ffffffff8105f278>] ? __kthread_parkme+0xad/0xad [68663.846486] [<ffffffff81435a88>] ret_from_fork+0x58/0x90 [68663.847760] [<ffffffff8105f278>] ? __kthread_parkme+0xad/0xad [68663.849503] ---[ end trace 798477c6d6dbaad6 ]--- [68663.850525] BTRFS: error (device sdc) in btrfs_remove_chunk:2652: errno=-28 No space left So fix this by verifying that enough space exists in system space_info, and reserving the space in the chunk block reserve, before attempting to delete the block group and allocate a new system chunk if we don't have enough space to perform the necessary updates and delete in the chunk tree. Like for the block group creation case, we don't error our if we fail to allocate a new system chunk, since we might end up not needing it (no node/leaf splits happen during the COW operations and/or we end up not needing to COW any btree nodes or leafs because they were already COWed in the current transaction and their writeback didn't start yet). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-03Btrfs: fix -ENOSPC when finishing block group creationFilipe Manana
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>
2015-06-03Btrfs: set UNWRITTEN for prealloc'ed extents in fiemapJosef Bacik
We should be doing this, it's weird we hadn't been doing this. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-03Btrfs: show subvol= and subvolid= in /proc/mountsOmar Sandoval
Now that we're guaranteed to have a meaningful root dentry, we can just export seq_dentry() and use it in btrfs_show_options(). The subvolume ID is easy to get and can also be useful, so put that in there, too. Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Omar Sandoval <osandov@osandov.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-03Btrfs: unify subvol= and subvolid= mountingOmar Sandoval
Currently, mounting a subvolume with subvolid= takes a different code path than mounting with subvol=. This isn't really a big deal except for the fact that mounts done with subvolid= or the default subvolume don't have a dentry that's connected to the dentry tree like in the subvol= case. To unify the code paths, when given subvolid= or using the default subvolume ID, translate it into a subvolume name by walking ROOT_BACKREFs in the root tree and INODE_REFs in the filesystem trees. Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Omar Sandoval <osandov@osandov.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-03Btrfs: fail on mismatched subvol and subvolid mount optionsOmar Sandoval
There's nothing to stop a user from passing both subvol= and subvolid= to mount, but if they don't refer to the same subvolume, someone is going to be surprised at some point. Error out on this case, but allow users to pass in both if they do match (which they could, for example, get out of /proc/mounts). Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Omar Sandoval <osandov@osandov.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-03Btrfs: clean up error handling in mount_subvol()Omar Sandoval
In preparation for new functionality in mount_subvol(), give it ownership of subvol_name and tidy up the error paths. Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Omar Sandoval <osandov@osandov.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-03Btrfs: remove all subvol options before mounting top-levelOmar Sandoval
Currently, setup_root_args() substitutes 's/subvol=[^,]*/subvolid=0/'. But, this means that if the user passes both a subvol and subvolid for some reason, we won't actually mount the top-level when we recursively mount. For example, consider: mkfs.btrfs -f /dev/sdb mount /dev/sdb /mnt btrfs subvol create /mnt/subvol1 # subvolid=257 btrfs subvol create /mnt/subvol2 # subvolid=258 umount /mnt mount -osubvol=/subvol1,subvolid=258 /dev/sdb /mnt In the final mount, subvol=/subvol1,subvolid=258 becomes subvolid=0,subvolid=258, and the last option takes precedence, so we mount subvol2 and try to look up subvol1 inside of it, which fails. So, instead, do a thorough scan through the argument list and remove any subvol= and subvolid= options, then append subvolid=0 to the end. This implicitly makes subvol= take precedence over subvolid=, but we're about to add a stricter check for that. This also makes setup_root_args() more generic, which we'll need soon. Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Omar Sandoval <osandov@osandov.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-03Btrfs: lock superblock before remounting for rw subvolOmar Sandoval
Since commit 0723a0473fb4 ("btrfs: allow mounting btrfs subvolumes with different ro/rw options"), when mounting a subvolume read/write when another subvolume has previously been mounted read-only, we first do a remount. However, this should be done with the superblock locked, as per sync_filesystem(): /* * We need to be protected against the filesystem going from * r/o to r/w or vice versa. */ WARN_ON(!rwsem_is_locked(&sb->s_umount)); This WARN_ON can easily be hit with: mkfs.btrfs -f /dev/vdb mount /dev/vdb /mnt btrfs subvol create /mnt/vol1 btrfs subvol create /mnt/vol2 umount /mnt mount -oro,subvol=/vol1 /dev/vdb /mnt mount -orw,subvol=/vol2 /dev/vdb /mnt2 Fixes: 0723a0473fb4 ("btrfs: allow mounting btrfs subvolumes with different ro/rw options") Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Omar Sandoval <osandov@osandov.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-03Btrfs: wake up extent state waiters on unlock through clear_extent_bitsFilipe Manana
When we clear an extent state's EXTENT_LOCKED bit with clear_extent_bits() through free_io_failure(), we weren't waking up any tasks waiting for the extent's state EXTENT_LOCKED bit, leading to an hang. So make sure clear_extent_bits() ends up waking up any waiters if the bit EXTENT_LOCKED is supplied by its callers. Zygo Blaxell was experiencing such hangs at inode eviction time after file unlinks. Thanks to him for a set of scripts to reproduce the issue. Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>