20b2e3029e
4742 Commits
Author | SHA1 | Message | Date | |
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20b2e3029e |
btrfs: Fix lockdep warning of wr_ctx->wr_lock in scrub_free_wr_ctx()
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> |
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e1d227a42e |
btrfs: Handle unaligned length in extent_same
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> |
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070034bdf9 |
Btrfs: btrfs_defrag_file: Fix calculation of max_to_defrag.
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> |
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e4826a5b24 |
Btrfs: btrfs_defrag_file: Fix ra_index computation.
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> |
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4617ea3a52 |
Btrfs: fix necessary chunk tree space calculation when allocating a chunk
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> |
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7558c8bc17 |
Btrfs: don't attach unnecessary extents to transaction on fsync
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> |
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b659ef0277 |
Btrfs: avoid syncing log in the fast fsync path when not necessary
Commit |
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1ab818b137 | Merge branch 'send_fixes_4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/fdmanana/linux into for-linus-4.2 | ||
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6ca0709756 |
Btrfs: fix hang during inode eviction due to concurrent readahead
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> |
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64c043de46 |
Btrfs: fix up read_tree_block to return proper error
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> |
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8635eda91e |
Btrfs: add missing free_extent_buffer
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> |
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0c304304fe |
Btrfs: remove csum_bytes_left
After commit
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39c2d7facc |
Btrfs: fix -ENOSPC on block group removal
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> |
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4fbcdf6694 |
Btrfs: fix -ENOSPC when finishing block group creation
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> |
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0d2b2372e0 |
Btrfs: set UNWRITTEN for prealloc'ed extents in fiemap
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> |
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c8d3fe028f |
Btrfs: show subvol= and subvolid= in /proc/mounts
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> |
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05dbe6837b |
Btrfs: unify subvol= and subvolid= mounting
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> |
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bb289b7be6 |
Btrfs: fail on mismatched subvol and subvolid mount options
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> |
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fa33065950 |
Btrfs: clean up error handling in mount_subvol()
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> |
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e6e4dbe894 |
Btrfs: remove all subvol options before mounting top-level
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> |
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773cd04ec1 |
Btrfs: lock superblock before remounting for rw subvol
Since commit |
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0f31871f44 |
Btrfs: wake up extent state waiters on unlock through clear_extent_bits
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> |
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c152b63efc |
Btrfs: fix chunk allocation regression leading to transaction abort
With commit |
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2037a0933b |
btrfs: use after free when closing devices
__btrfs_close_devices() would call_rcu to free the device, which is racy with list_for_each_entry() accessing the memory to retrieve the next device on the list. Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com> |
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01b810b889 |
btrfs: make root id query unprivileged
The INO_LOOKUP ioctl can lookup path for a given inode number and is thus restricted. As a sideefect it can find the root id of the containing subvolume and we're using this int the 'btrfs inspect rootid' command. The restriction is unnecessary in case we set the ioctl args args::treeid = 0 args::objectid = 256 (BTRFS_FIRST_FREE_OBJECTID) Then the path will be empty and the treeid is filled with the root id of the inode on which the ioctl is called. This behaviour is unchanged, after the root restriction is removed. Signed-off-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com> |
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2e6e518335 |
Btrfs: fix block group ->space_info null pointer dereference
When we create a block group we add it to the rbtree of block groups before setting its ->space_info field (while it's NULL). This is problematic since other tasks can access the block group from the rbtree and attempt to use its ->space_info before it is set by btrfs_make_block_group(). This can happen for example when a concurrent fitrim ioctl operation is ongoing, which produces a trace like the following when CONFIG_DEBUG_PAGEALLOC is set. [11509.604369] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 [11509.606373] IP: [<ffffffff8107d675>] __lock_acquire+0xb4/0xf02 [11509.608179] PGD 2296a8067 PUD 22f4a2067 PMD 0 [11509.608179] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [11509.608179] Modules linked in: btrfs crc32c_generic xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop fuse acpi_cpufreq processor i2c_piix4 psmou [11509.608179] CPU: 10 PID: 8538 Comm: fstrim Tainted: G W 4.0.0-rc5-btrfs-next-9+ #2 [11509.608179] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 [11509.608179] task: ffff88009f5c46d0 ti: ffff8801b3edc000 task.ti: ffff8801b3edc000 [11509.608179] RIP: 0010:[<ffffffff8107d675>] [<ffffffff8107d675>] __lock_acquire+0xb4/0xf02 [11509.608179] RSP: 0018:ffff8801b3edf9e8 EFLAGS: 00010002 [11509.608179] RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000000 [11509.608179] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000018 [11509.608179] RBP: ffff8801b3edfaa8 R08: 0000000000000001 R09: 0000000000000000 [11509.608179] R10: 0000000000000000 R11: ffff88009f5c4f98 R12: 0000000000000000 [11509.608179] R13: 0000000000000000 R14: 0000000000000018 R15: ffff88009f5c46d0 [11509.608179] FS: 00007f280a10e840(0000) GS:ffff88023ed40000(0000) knlGS:0000000000000000 [11509.608179] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [11509.608179] CR2: 0000000000000018 CR3: 00000002119bc000 CR4: 00000000000006e0 [11509.608179] Stack: [11509.608179] 0000000000000000 0000000000000000 0000000000000004 0000000000000000 [11509.608179] ffff880100000000 ffffffff00000000 0000000000000001 ffffffff00000000 [11509.608179] 0000000000000001 0000000000000000 ffff880100000000 00000000000006c4 [11509.608179] Call Trace: [11509.608179] [<ffffffff8107dc57>] ? __lock_acquire+0x696/0xf02 [11509.608179] [<ffffffff8107e806>] lock_acquire+0xa5/0x116 [11509.608179] [<ffffffffa04cc876>] ? do_trimming+0x51/0x145 [btrfs] [11509.608179] [<ffffffff81434f37>] _raw_spin_lock+0x34/0x44 [11509.608179] [<ffffffffa04cc876>] ? do_trimming+0x51/0x145 [btrfs] [11509.608179] [<ffffffffa04cc876>] do_trimming+0x51/0x145 [btrfs] [11509.608179] [<ffffffffa04cde7d>] btrfs_trim_block_group+0x201/0x491 [btrfs] [11509.608179] [<ffffffffa04849e2>] btrfs_trim_fs+0xe0/0x129 [btrfs] [11509.608179] [<ffffffffa04bb80a>] btrfs_ioctl_fitrim+0x138/0x167 [btrfs] [11509.608179] [<ffffffffa04c002f>] btrfs_ioctl+0x50d/0x21e8 [btrfs] [11509.608179] [<ffffffff81123bda>] ? might_fault+0x58/0xb5 [11509.608179] [<ffffffff81123bda>] ? might_fault+0x58/0xb5 [11509.608179] [<ffffffff81123bda>] ? might_fault+0x58/0xb5 [11509.608179] [<ffffffff81158050>] ? cp_new_stat+0x147/0x15e [11509.608179] [<ffffffff81163041>] do_vfs_ioctl+0x3c6/0x479 [11509.608179] [<ffffffff81158116>] ? SYSC_newfstat+0x25/0x2e [11509.608179] [<ffffffff81435b54>] ? ret_from_sys_call+0x1d/0x58 [11509.608179] [<ffffffff8116b915>] ? __fget_light+0x2d/0x4f [11509.608179] [<ffffffff8116314e>] SyS_ioctl+0x5a/0x7f [11509.608179] [<ffffffff81435b32>] system_call_fastpath+0x12/0x17 [11509.608179] Code: f4 01 00 0f 85 c0 00 00 00 48 c7 c1 f3 1f 7d 81 48 c7 c2 aa cb 7c 81 be fc 0b 00 00 eb 70 83 3d 61 eb 9c 00 00 0f 84 a5 00 00 00 <49> 81 3e 40 a3 2b 82 b8 00 00 00 [11509.608179] RIP [<ffffffff8107d675>] __lock_acquire+0xb4/0xf02 [11509.608179] RSP <ffff8801b3edf9e8> [11509.608179] CR2: 0000000000000018 [11509.608179] ---[ end trace 570a5c6769f0e49a ]--- Which corresponds to the following access in fs/btrfs/free-space-cache.c: static int do_trimming(struct btrfs_block_group_cache *block_group, u64 *total_trimmed, u64 start, u64 bytes, u64 reserved_start, u64 reserved_bytes, struct btrfs_trim_range *trim_entry) { struct btrfs_space_info *space_info = block_group->space_info; (...) spin_lock(&space_info->lock); ^^^^^ - block_group->space_info is NULL... Fix this by ensuring the block group's ->space_info is set before adding the block group to the rbtree. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com> |
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33b97e4327 |
Btrfs: check error before reporting missing device and add uuid
Report missing device when add is successful, otherwise it would exit as ENOMEM. And add uuid to the report. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com> |
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1f6e4b3f9f |
btrfs: Fix superblock csum type check.
Old csum type check is wrong and can't catch csum_type 1(not supported). Fix it to avoid hostile 0 division. Reported-by: Lukas Lueg <lukas.lueg@gmail.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com> |
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619d8c4ef7 |
Btrfs: incremental send, fix clone operations for compressed extents
Marc reported a problem where the receiving end of an incremental send was performing clone operations that failed with -EINVAL. This happened because, unlike for uncompressed extents, we were not checking if the source clone offset and length, after summing the data offset, falls within the source file's boundaries. So make sure we do such checks when attempting to issue clone operations for compressed extents. Problem reproducible with the following steps: $ mkfs.btrfs -f /dev/sdb $ mount -o compress /dev/sdb /mnt $ mkfs.btrfs -f /dev/sdc $ mount -o compress /dev/sdc /mnt2 # Create the file with a single extent of 128K. This creates a metadata file # extent item with a data start offset of 0 and a logical length of 128K. $ xfs_io -f -c "pwrite -S 0xaa 64K 128K" -c "fsync" /mnt/foo # Now rewrite the range 64K to 112K of our file. This will make the inode's # metadata continue to point to the 128K extent we created before, but now # with an extent item that points to the extent with a data start offset of # 112K and a logical length of 16K. # That metadata file extent item is associated with the logical file offset # at 176K and covers the logical file range 176K to 192K. $ xfs_io -c "pwrite -S 0xbb 64K 112K" -c "fsync" /mnt/foo # Now rewrite the range 180K to 12K. This will make the inode's metadata # continue to point the the 128K extent we created earlier, with a single # extent item that points to it with a start offset of 112K and a logical # length of 4K. # That metadata file extent item is associated with the logical file offset # at 176K and covers the logical file range 176K to 180K. $ xfs_io -c "pwrite -S 0xcc 180K 12K" -c "fsync" /mnt/foo $ btrfs subvolume snapshot -r /mnt /mnt/snap1 $ touch /mnt/bar # Calls the btrfs clone ioctl. $ ~/xfstests/src/cloner -s $((176 * 1024)) -d $((176 * 1024)) \ -l $((4 * 1024)) /mnt/foo /mnt/bar $ btrfs subvolume snapshot -r /mnt /mnt/snap2 $ btrfs send /mnt/snap1 | btrfs receive /mnt2 At subvol /mnt/snap1 At subvol snap1 $ btrfs send -p /mnt/snap1 /mnt/snap2 | btrfs receive /mnt2 At subvol /mnt/snap2 At snapshot snap2 ERROR: failed to clone extents to bar Invalid argument A test case for fstests follows soon. Reported-by: Marc MERLIN <marc@merlins.org> Tested-by: Marc MERLIN <marc@merlins.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Tested-by: David Sterba <dsterba@suse.cz> Tested-by: Jan Alexander Steffens (heftig) <jan.steffens@gmail.com> Signed-off-by: Chris Mason <clm@fb.com> |
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ab3680dd18 |
btrfs: qgroup: Fix possible leak in btrfs_add_qgroup_relation()
Commit
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35c766425a |
Btrfs: fix mutex unlock without prior lock on space cache truncation
If the call to btrfs_truncate_inode_items() failed and we don't have a block
group, we were unlocking the cache_write_mutex without having locked it (we
do it only if we have a block group).
Fixes:
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816fcebe8f |
Btrfs: log when missing device is created
Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com> |
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6d13f5497f |
btrfs: fix warnings after changes in btrfs_abort_transaction
fs/btrfs/volumes.c: In function ‘btrfs_create_uuid_tree’: fs/btrfs/volumes.c:3909:3: warning: format ‘%d’ expects argument of type ‘int’, but argument 4 has type ‘long int’ [-Wformat=] btrfs_abort_transaction(trans, tree_root, ^ CC [M] fs/btrfs/ioctl.o fs/btrfs/ioctl.c: In function ‘create_subvol’: fs/btrfs/ioctl.c:549:3: warning: format ‘%d’ expects argument of type ‘int’, but argument 4 has type ‘long int’ [-Wformat=] btrfs_abort_transaction(trans, root, PTR_ERR(new_root)); PTR_ERR returns long, but we're really using 'int' for the error codes everywhere so just set and use the local variable. Signed-off-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com> |
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c0d19e2b9a |
btrfs: add 'cold' compiler annotations to all error handling functions
The annotated functios will be placed into .text.unlikely section. The annotation also hints compiler to move the code out of the hot paths, and may implicitly mark if-statement leading to that block as unlikely. This is a heuristic, the impact on the generated code is not significant. Signed-off-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com> |
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1a9a8a71ed |
btrfs: report exact callsite where transaction abort occurs
WARN is called from a single location and all bugreports say that's in super.c __btrfs_abort_transaction. This is slightly confusing as we'd rather want to know the exact callsite. Whereas this information is printed in the syslog below the stacktrace, this requires further look and we usually see only the headline from WARNING. Moving the WARN into the macro has to inline some code and increases code by a few kilobytes: text data bss dec hex filename 835481 20305 14120 869906 d4612 btrfs.ko.before 842883 20305 14120 877308 d62fc btrfs.ko.after The delta is +7k (130+ calls), measured on 3.19 x86_64, distro config. The increase is not small and could lead to worse icache use. The code is on error/exit paths that can be recognized by compiler as cold and moved out of the way so the impact is speculated to be low, if measurable at all. Signed-off-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com> |
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13028901a4 |
btrfs: let tree defrag work in SSD mode
Long time ago (2008) the defrag was automatic for new b-tree writes but has been disabled after performance problems. There was a leftover in tree-defrag.c that effectively stops any defragmentation on b-trees. This is a bit unexpected and IMHO undesired. The SSD mode is an optimization and defrag is supposed to work if the users asks for it. Related commits: |
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53e489bc8c |
Btrfs: check pending chunks when shrinking fs to avoid corruption
When we shrink the usable size of a device (its total_bytes), we go over all the device extent items in the device tree and attempt to relocate the chunk of any device extent that goes beyond the new usable size for the device. We do that after setting the new usable size (total_bytes) in the device object, so that all new allocations (and reallocations) don't use areas of the device that go beyond the new (shorter) size. However we were not considering that before setting the new size in the device, pending chunks might have been created that use device extents that go beyond the new size, and those device extents are not yet in the device tree after we search the device tree - they are still attached to the list of new block group for some ongoing transaction handle, and they are only added to the device tree when the transaction handle is ended (via btrfs_create_pending_block_groups()). So check for pending chunks with device extents that go beyond the new size and if any exists, commit the current transaction and repeat the search in the device tree. Not doing this it would mean we would return success to user space while still having extents that go beyond the new size, and later user space could override those locations on the device while the fs still references them, causing all sorts of corruption and unexpected events. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com> |
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64ad6c4889 |
Btrfs: don't invalidate root dentry when subvolume deletion fails
Since commit |
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8b191a6849 |
Btrfs: incremental send, check if orphanized dir inode needs delayed rename
If a directory inode is orphanized, because some inode previously processed has a new name that collides with the old name of the current inode, we need to check if it needs its rename operation delayed too, as its ancestor-descendent relationship with some other inode might have been reversed between the parent and send snapshots and therefore its rename operation needs to happen after that other inode is renamed. For example, for the following reproducer where this is needed (provided by Robbie Ko): $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkfs.btrfs -f /dev/sdc $ mount /dev/sdc /mnt2 $ mkdir -p /mnt/data/n1/n2 $ mkdir /mnt/data/n4 $ mkdir -p /mnt/data/t6/t7 $ mkdir /mnt/data/t5 $ mkdir /mnt/data/t7 $ mkdir /mnt/data/n4/t2 $ mkdir /mnt/data/t4 $ mkdir /mnt/data/t3 $ mv /mnt/data/t7 /mnt/data/n4/t2 $ mv /mnt/data/t4 /mnt/data/n4/t2/t7 $ mv /mnt/data/t5 /mnt/data/n4/t2/t7/t4 $ mv /mnt/data/t6 /mnt/data/n4/t2/t7/t4/t5 $ mv /mnt/data/n1/n2 /mnt/data/n4/t2/t7/t4/t5/t6 $ mv /mnt/data/n1 /mnt/data/n4/t2/t7/t4/t5/t6 $ mv /mnt/data/n4/t2/t7/t4/t5/t6/t7 /mnt/data/n4/t2/t7/t4/t5/t6/n2 $ mv /mnt/data/t3 /mnt/data/n4/t2/t7/t4/t5/t6/n2/t7 $ btrfs subvolume snapshot -r /mnt /mnt/snap1 $ mv /mnt/data/n4/t2/t7/t4/t5/t6/n1 /mnt/data/n4 $ mv /mnt/data/n4/t2 /mnt/data/n4/n1 $ mv /mnt/data/n4/n1/t2/t7/t4/t5/t6/n2 /mnt/data/n4/n1/t2 $ mv /mnt/data/n4/n1/t2/n2/t7/t3 /mnt/data/n4/n1/t2 $ mv /mnt/data/n4/n1/t2/t7/t4/t5/t6 /mnt/data/n4/n1/t2 $ mv /mnt/data/n4/n1/t2/t7/t4 /mnt/data/n4/n1/t2/t6 $ mv /mnt/data/n4/n1/t2/t7 /mnt/data/n4/n1/t2/t3 $ mv /mnt/data/n4/n1/t2/n2/t7 /mnt/data/n4/n1/t2 $ btrfs subvolume snapshot -r /mnt /mnt/snap2 $ btrfs send /mnt/snap1 | btrfs receive /mnt2 $ btrfs send -p /mnt/snap1 /mnt/snap2 | btrfs receive /mnt2 ERROR: send ioctl failed with -12: Cannot allocate memory Where the parent snapshot directory hierarchy is the following: . (ino 256) |-- data/ (ino 257) |-- n4/ (ino 260) |-- t2/ (ino 265) |-- t7/ (ino 264) |-- t4/ (ino 266) |-- t5/ (ino 263) |-- t6/ (ino 261) |-- n1/ (ino 258) |-- n2/ (ino 259) |-- t7/ (ino 262) |-- t3/ (ino 267) And the send snapshot's directory hierarchy is the following: . (ino 256) |-- data/ (ino 257) |-- n4/ (ino 260) |-- n1/ (ino 258) |-- t2/ (ino 265) |-- n2/ (ino 259) |-- t3/ (ino 267) | |-- t7 (ino 264) | |-- t6/ (ino 261) | |-- t4/ (ino 266) | |-- t5/ (ino 263) | |-- t7/ (ino 262) While processing inode 262 we orphanize inode 264 and later attempt to rename inode 264 to its new name/location, which resulted in building an incorrect destination path string for the rename operation with the value "data/n4/t2/t7/t4/t5/t6/n2/t7/t3/t7". This rename operation must have been done only after inode 267 is processed and renamed, as the ancestor-descendent relationship between inodes 264 and 267 was reversed between both snapshots, because otherwise it results in an infinite loop when building the path string for inode 264 when we are processing an inode with a number larger than 264. That loop is the following: start inode 264, send progress of 265 for example parent of 264 -> 267 parent of 267 -> 262 parent of 262 -> 259 parent of 259 -> 261 parent of 261 -> 263 parent of 263 -> 266 parent of 266 -> 264 |--> back to first iteration while current path string length is <= PATH_MAX, and fail with -ENOMEM otherwise So fix this by making the check if we need to delay a directory rename regardless of the current inode having been orphanized or not. A test case for fstests follows soon. Thanks to Robbie Ko for providing a reproducer for this problem. Reported-by: Robbie Ko <robbieko@synology.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> |
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80aa602756 |
Btrfs: incremental send, don't delay directory renames unnecessarily
Even though we delay the rename of directories when they become descendents of other directories that were also renamed in the send root to prevent infinite path build loops, we were doing it in cases where this was not needed and was actually harmful resulting in infinite path build loops as we ended up with a circular dependency of delayed directory renames. Consider the following reproducer: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkfs.btrfs -f /dev/sdc $ mount /dev/sdc /mnt2 $ mkdir /mnt/data $ mkdir /mnt/data/n1 $ mkdir /mnt/data/n1/n2 $ mkdir /mnt/data/n4 $ mkdir /mnt/data/n1/n2/p1 $ mkdir /mnt/data/n1/n2/p1/p2 $ mkdir /mnt/data/t6 $ mkdir /mnt/data/t7 $ mkdir -p /mnt/data/t5/t7 $ mkdir /mnt/data/t2 $ mkdir /mnt/data/t4 $ mkdir -p /mnt/data/t1/t3 $ mkdir /mnt/data/p1 $ mv /mnt/data/t1 /mnt/data/p1 $ mkdir -p /mnt/data/p1/p2 $ mv /mnt/data/t4 /mnt/data/p1/p2/t1 $ mv /mnt/data/t5 /mnt/data/n4/t5 $ mv /mnt/data/n1/n2/p1/p2 /mnt/data/n4/t5/p2 $ mv /mnt/data/t7 /mnt/data/n4/t5/p2/t7 $ mv /mnt/data/t2 /mnt/data/n4/t1 $ mv /mnt/data/p1 /mnt/data/n4/t5/p2/p1 $ mv /mnt/data/n1/n2 /mnt/data/n4/t5/p2/p1/p2/n2 $ mv /mnt/data/n4/t5/p2/p1/p2/t1 /mnt/data/n4/t5/p2/p1/p2/n2/t1 $ mv /mnt/data/n4/t5/t7 /mnt/data/n4/t5/p2/p1/p2/n2/t1/t7 $ mv /mnt/data/n4/t5/p2/p1/t1/t3 /mnt/data/n4/t5/p2/p1/p2/n2/t1/t3 $ mv /mnt/data/n4/t5/p2/p1/p2/n2/p1 /mnt/data/n4/t5/p2/p1/p2/n2/t1/t7/p1 $ mv /mnt/data/t6 /mnt/data/n4/t5/p2/p1/p2/n2/t1/t3/t5 $ mv /mnt/data/n4/t5/p2/p1/t1 /mnt/data/n4/t5/p2/p1/p2/n2/t1/t3/t1 $ mv /mnt/data/n1 /mnt/data/n4/t5/p2/p1/p2/n2/t1/t7/p1/n1 $ btrfs subvolume snapshot -r /mnt /mnt/snap1 $ mv /mnt/data/n4/t1 /mnt/data/n4/t5/p2/p1/p2/n2/t1/t7/p1/t1 $ mv /mnt/data/n4/t5/p2/p1/p2/n2/t1 /mnt/data/n4/ $ mv /mnt/data/n4/t5/p2/p1/p2/n2 /mnt/data/n4/t1/n2 $ mv /mnt/data/n4/t1/t7/p1 /mnt/data/n4/t1/n2/p1 $ mv /mnt/data/n4/t1/t3/t1 /mnt/data/n4/t1/n2/t1 $ mv /mnt/data/n4/t1/t3 /mnt/data/n4/t1/n2/t1/t3 $ mv /mnt/data/n4/t5/p2/p1/p2 /mnt/data/n4/t1/n2/p1/p2 $ mv /mnt/data/n4/t1/t7 /mnt/data/n4/t1/n2/p1/t7 $ mv /mnt/data/n4/t5/p2/p1 /mnt/data/n4/t1/n2/p1/p2/p1 $ mv /mnt/data/n4/t1/n2/t1/t3/t5 /mnt/data/n4/t1/n2/p1/p2/t5 $ mv /mnt/data/n4/t5 /mnt/data/n4/t1/n2/p1/p2/p1/t5 $ mv /mnt/data/n4/t1/n2/p1/p2/p1/t5/p2 /mnt/data/n4/t1/n2/p1/p2/p1/p2 $ mv /mnt/data/n4/t1/n2/p1/p2/p1/p2/t7 /mnt/data/n4/t1/t7 $ btrfs subvolume snapshot -r /mnt /mnt/snap2 $ btrfs send /mnt/snap1 | btrfs receive /mnt2 $ btrfs send -p /mnt/snap1 /mnt/snap2 | btrfs receive -vv /mnt2 ERROR: send ioctl failed with -12: Cannot allocate memory This reproducer resulted in an infinite path build loop when building the path for inode 266 because the following circular dependency of delayed directory renames was created: ino 272 <- ino 261 <- ino 259 <- ino 268 <- ino 267 <- ino 261 Where the notation "X <- Y" means the rename of inode X is delayed by the rename of inode Y (X will be renamed after Y is renamed). This resulted in an infinite path build loop of inode 266 because that inode has inode 261 as an ancestor in the send root and inode 261 is in the circular dependency of delayed renames listed above. Fix this by not delaying the rename of a directory inode if an ancestor of the inode in the send root, which has a delayed rename operation, is not also a descendent of the inode in the parent root. Thanks to Robbie Ko for sending the reproducer example. A test case for xfstests follows soon. Reported-by: Robbie Ko <robbieko@synology.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> |
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7ce14f6ff2 |
Merge branch 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason: "I fixed up a regression from 4.0 where conversion between different raid levels would sometimes bail out without converting. Filipe tracked down a race where it was possible to double allocate chunks on the drive. Mark has a fix for fiemap. All three will get bundled off for stable as well" * 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: fix regression in raid level conversion Btrfs: fix racy system chunk allocation when setting block group ro btrfs: clear 'ret' in btrfs_check_shared() loop |
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153c35b6cc |
Btrfs: fix regression in raid level conversion
Commit |
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a96295965b |
Btrfs: fix racy system chunk allocation when setting block group ro
If while setting a block group read-only we end up allocating a system
chunk, through check_system_chunk(), we were not doing it while holding
the chunk mutex which is a problem if a concurrent chunk allocation is
happening, through do_chunk_alloc(), as it means both block groups can
end up using the same logical addresses and physical regions in the
device(s). So make sure we hold the chunk mutex.
Cc: stable@vger.kernel.org # 4.0+
Fixes:
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2c2ed5aa01 |
btrfs: clear 'ret' in btrfs_check_shared() loop
btrfs_check_shared() is leaking a return value of '1' from find_parent_nodes(). As a result, callers (in this case, extent_fiemap()) are told extents are shared when they are not. This in turn broke fiemap on btrfs for kernels v3.18 and up. The fix is simple - we just have to clear 'ret' after we are done processing the results of find_parent_nodes(). It wasn't clear to me at first what was happening with return values in btrfs_check_shared() and find_parent_nodes() - thanks to Josef for the help on irc. I added documentation to both functions to make things more clear for the next hacker who might come across them. If we could queue this up for -stable too that would be great. Signed-off-by: Mark Fasheh <mfasheh@suse.de> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com> |
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c7309e88a6 |
Merge branch 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason: "The first commit is a fix from Filipe for a very old extent buffer reuse race that triggered a BUG_ON. It hasn't come up often, I looked through old logs at FB and we hit it a handful of times over the last year. The rest are other corners he hit during testing" * 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: fix race when reusing stale extent buffers that leads to BUG_ON Btrfs: fix race between block group creation and their cache writeout Btrfs: fix panic when starting bg cache writeout after IO error Btrfs: fix crash after inode cache writeback failure |
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062c19e9dd |
Btrfs: fix race when reusing stale extent buffers that leads to BUG_ON
There's a race between releasing extent buffers that are flagged as stale and recycling them that makes us it the following BUG_ON at btrfs_release_extent_buffer_page: BUG_ON(extent_buffer_under_io(eb)) The BUG_ON is triggered because the extent buffer has the flag EXTENT_BUFFER_DIRTY set as a consequence of having been reused and made dirty by another concurrent task. Here follows a sequence of steps that leads to the BUG_ON. CPU 0 CPU 1 CPU 2 path->nodes[0] == eb X X->refs == 2 (1 for the tree, 1 for the path) btrfs_header_generation(X) == current trans id flag EXTENT_BUFFER_DIRTY set on X btrfs_release_path(path) unlocks X reads eb X X->refs incremented to 3 locks eb X btrfs_del_items(X) X becomes empty clean_tree_block(X) clear EXTENT_BUFFER_DIRTY from X btrfs_del_leaf(X) unlocks X extent_buffer_get(X) X->refs incremented to 4 btrfs_free_tree_block(X) X's range is not pinned X's range added to free space cache free_extent_buffer_stale(X) lock X->refs_lock set EXTENT_BUFFER_STALE on X release_extent_buffer(X) X->refs decremented to 3 unlocks X->refs_lock btrfs_release_path() unlocks X free_extent_buffer(X) X->refs becomes 2 __btrfs_cow_block(Y) btrfs_alloc_tree_block() btrfs_reserve_extent() find_free_extent() gets offset == X->start btrfs_init_new_buffer(X->start) btrfs_find_create_tree_block(X->start) alloc_extent_buffer(X->start) find_extent_buffer(X->start) finds eb X in radix tree free_extent_buffer(X) lock X->refs_lock test X->refs == 2 test bit EXTENT_BUFFER_STALE is set test !extent_buffer_under_io(eb) increments X->refs to 3 mark_extent_buffer_accessed(X) check_buffer_tree_ref(X) --> does nothing, X->refs >= 2 and EXTENT_BUFFER_TREE_REF is set in X clear EXTENT_BUFFER_STALE from X locks X btrfs_mark_buffer_dirty() set_extent_buffer_dirty(X) check_buffer_tree_ref(X) --> does nothing, X->refs >= 2 and EXTENT_BUFFER_TREE_REF is set sets EXTENT_BUFFER_DIRTY on X test and clear EXTENT_BUFFER_TREE_REF decrements X->refs to 2 release_extent_buffer(X) decrements X->refs to 1 unlock X->refs_lock unlock X free_extent_buffer(X) lock X->refs_lock release_extent_buffer(X) decrements X->refs to 0 btrfs_release_extent_buffer_page(X) BUG_ON(extent_buffer_under_io(X)) --> EXTENT_BUFFER_DIRTY set on X Fix this by making find_extent buffer wait for any ongoing task currently executing free_extent_buffer()/free_extent_buffer_stale() if the extent buffer has the stale flag set. A more clean alternative would be to always increment the extent buffer's reference count while holding its refs_lock spinlock but find_extent_buffer is a performance critical area and that would cause lock contention whenever multiple tasks search for the same extent buffer concurrently. A build server running a SLES 12 kernel (3.12 kernel + over 450 upstream btrfs patches backported from newer kernels) was hitting this often: [1212302.461948] kernel BUG at ../fs/btrfs/extent_io.c:4507! (...) [1212302.470219] CPU: 1 PID: 19259 Comm: bs_sched Not tainted 3.12.36-38-default #1 [1212302.540792] Hardware name: Supermicro PDSM4/PDSM4, BIOS 6.00 04/17/2006 [1212302.540792] task: ffff8800e07e0100 ti: ffff8800d6412000 task.ti: ffff8800d6412000 [1212302.540792] RIP: 0010:[<ffffffffa0507081>] [<ffffffffa0507081>] btrfs_release_extent_buffer_page.constprop.51+0x101/0x110 [btrfs] (...) [1212302.630008] Call Trace: [1212302.630008] [<ffffffffa05070cd>] release_extent_buffer+0x3d/0xa0 [btrfs] [1212302.630008] [<ffffffffa04c2d9d>] btrfs_release_path+0x1d/0xa0 [btrfs] [1212302.630008] [<ffffffffa04c5c7e>] read_block_for_search.isra.33+0x13e/0x3a0 [btrfs] [1212302.630008] [<ffffffffa04c8094>] btrfs_search_slot+0x3f4/0xa80 [btrfs] [1212302.630008] [<ffffffffa04cf5d8>] lookup_inline_extent_backref+0xf8/0x630 [btrfs] [1212302.630008] [<ffffffffa04d13dd>] __btrfs_free_extent+0x11d/0xc40 [btrfs] [1212302.630008] [<ffffffffa04d64a4>] __btrfs_run_delayed_refs+0x394/0x11d0 [btrfs] [1212302.630008] [<ffffffffa04db379>] btrfs_run_delayed_refs.part.66+0x69/0x280 [btrfs] [1212302.630008] [<ffffffffa04ed2ad>] __btrfs_end_transaction+0x2ad/0x3d0 [btrfs] [1212302.630008] [<ffffffffa04f7505>] btrfs_evict_inode+0x4a5/0x500 [btrfs] [1212302.630008] [<ffffffff811b9e28>] evict+0xa8/0x190 [1212302.630008] [<ffffffff811b0330>] do_unlinkat+0x1a0/0x2b0 I was also able to reproduce this on a 3.19 kernel, corresponding to Chris' integration branch from about a month ago, running the following stress test on a qemu/kvm guest (with 4 virtual cpus and 16Gb of ram): while true; do mkfs.btrfs -l 4096 -f -b `expr 20 \* 1024 \* 1024 \* 1024` /dev/sdd mount /dev/sdd /mnt snapshot_cmd="btrfs subvolume snapshot -r /mnt" snapshot_cmd="$snapshot_cmd /mnt/snap_\`date +'%H_%M_%S_%N'\`" fsstress -d /mnt -n 25000 -p 8 -x "$snapshot_cmd" -X 100 umount /mnt done Which usually triggers the BUG_ON within less than 24 hours: [49558.618097] ------------[ cut here ]------------ [49558.619732] kernel BUG at fs/btrfs/extent_io.c:4551! (...) [49558.620031] CPU: 3 PID: 23908 Comm: fsstress Tainted: G W 3.19.0-btrfs-next-7+ #3 [49558.620031] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 [49558.620031] task: ffff8800319fc0d0 ti: ffff880220da8000 task.ti: ffff880220da8000 [49558.620031] RIP: 0010:[<ffffffffa0476b1a>] [<ffffffffa0476b1a>] btrfs_release_extent_buffer_page+0x20/0xe9 [btrfs] (...) [49558.620031] Call Trace: [49558.620031] [<ffffffffa0476c73>] release_extent_buffer+0x90/0xd3 [btrfs] [49558.620031] [<ffffffff8142b10c>] ? _raw_spin_lock+0x3b/0x43 [49558.620031] [<ffffffffa0477052>] ? free_extent_buffer+0x37/0x94 [btrfs] [49558.620031] [<ffffffffa04770ab>] free_extent_buffer+0x90/0x94 [btrfs] [49558.620031] [<ffffffffa04396d5>] btrfs_release_path+0x4a/0x69 [btrfs] [49558.620031] [<ffffffffa0444907>] __btrfs_free_extent+0x778/0x80c [btrfs] [49558.620031] [<ffffffffa044a485>] __btrfs_run_delayed_refs+0xad2/0xc62 [btrfs] [49558.728054] [<ffffffff811420d5>] ? kmemleak_alloc_recursive.constprop.52+0x16/0x18 [49558.728054] [<ffffffffa044c1e8>] btrfs_run_delayed_refs+0x6d/0x1ba [btrfs] [49558.728054] [<ffffffffa045917f>] ? join_transaction.isra.9+0xb9/0x36b [btrfs] [49558.728054] [<ffffffffa045a75c>] btrfs_commit_transaction+0x4c/0x981 [btrfs] [49558.728054] [<ffffffffa0434f86>] btrfs_sync_fs+0xd5/0x10d [btrfs] [49558.728054] [<ffffffff81155923>] ? iterate_supers+0x60/0xc4 [49558.728054] [<ffffffff8117966a>] ? do_sync_work+0x91/0x91 [49558.728054] [<ffffffff8117968a>] sync_fs_one_sb+0x20/0x22 [49558.728054] [<ffffffff81155939>] iterate_supers+0x76/0xc4 [49558.728054] [<ffffffff811798e8>] sys_sync+0x55/0x83 [49558.728054] [<ffffffff8142bbd2>] system_call_fastpath+0x12/0x17 Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com> |
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ff1f8250a9 |
Btrfs: fix race between block group creation and their cache writeout
So creating a block group has 2 distinct phases:
Phase 1 - creates the btrfs_block_group_cache item and adds it to the
rbtree fs_info->block_group_cache_tree and to the corresponding list
space_info->block_groups[];
Phase 2 - adds the block group item to the extent tree and corresponding
items to the chunk tree.
The first phase adds the block_group_cache_item to a list of pending block
groups in the transaction handle, and phase 2 happens when
btrfs_end_transaction() is called against the transaction handle.
It happens that once phase 1 completes, other concurrent tasks that use
their own transaction handle, but points to the same running transaction
(struct btrfs_trans_handle->transaction), can use this block group for
space allocations and therefore mark it dirty. Dirty block groups are
tracked in a list belonging to the currently running transaction (struct
btrfs_transaction) and not in the transaction handle (btrfs_trans_handle).
This is a problem because once a task calls btrfs_commit_transaction(),
it calls btrfs_start_dirty_block_groups() which will see all dirty block
groups and attempt to start their writeout, including those that are
still attached to the transaction handle of some concurrent task that
hasn't called btrfs_end_transaction() yet - which means those block
groups haven't gone through phase 2 yet and therefore when
write_one_cache_group() is called, it won't find the block group items
in the extent tree and abort the current transaction with -ENOENT,
turning the fs into readonly mode and require a remount.
Fix this by ignoring -ENOENT when looking for block group items in the
extent tree when we attempt to start the writeout of the block group
caches outside the critical section of the transaction commit. We will
try again later during the critical section and if there we still don't
find the block group item in the extent tree, we then abort the current
transaction.
This issue happened twice, once while running fstests btrfs/067 and once
for btrfs/078, which produced the following trace:
[ 3278.703014] WARNING: CPU: 7 PID: 18499 at fs/btrfs/super.c:260 __btrfs_abort_transaction+0x52/0x114 [btrfs]()
[ 3278.707329] BTRFS: Transaction aborted (error -2)
(...)
[ 3278.731555] Call Trace:
[ 3278.732396] [<ffffffff8142fa46>] dump_stack+0x4f/0x7b
[ 3278.733860] [<ffffffff8108b6a2>] ? console_unlock+0x361/0x3ad
[ 3278.735312] [<ffffffff81045ea5>] warn_slowpath_common+0xa1/0xbb
[ 3278.736874] [<ffffffffa03ada6d>] ? __btrfs_abort_transaction+0x52/0x114 [btrfs]
[ 3278.738302] [<ffffffff81045f05>] warn_slowpath_fmt+0x46/0x48
[ 3278.739520] [<ffffffffa03ada6d>] __btrfs_abort_transaction+0x52/0x114 [btrfs]
[ 3278.741222] [<ffffffffa03b9e56>] write_one_cache_group+0xae/0xbf [btrfs]
[ 3278.742797] [<ffffffffa03c487b>] btrfs_start_dirty_block_groups+0x170/0x2b2 [btrfs]
[ 3278.744492] [<ffffffffa03d309c>] btrfs_commit_transaction+0x130/0x9c9 [btrfs]
[ 3278.746084] [<ffffffff8107d33d>] ? trace_hardirqs_on+0xd/0xf
[ 3278.747249] [<ffffffffa03e5660>] btrfs_sync_file+0x313/0x387 [btrfs]
[ 3278.748744] [<ffffffff8117acad>] vfs_fsync_range+0x95/0xa4
[ 3278.749958] [<ffffffff81435b54>] ? ret_from_sys_call+0x1d/0x58
[ 3278.751218] [<ffffffff8117acd8>] vfs_fsync+0x1c/0x1e
[ 3278.754197] [<ffffffff8117ae54>] do_fsync+0x34/0x4e
[ 3278.755192] [<ffffffff8117b07c>] SyS_fsync+0x10/0x14
[ 3278.756236] [<ffffffff81435b32>] system_call_fastpath+0x12/0x17
[ 3278.757366] ---[ end trace 9a4d4df4969709aa ]---
Fixes:
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28aeeac1dd |
Btrfs: fix panic when starting bg cache writeout after IO error
When waiting for the writeback of block group cache we returned immediately if there was an error during writeback without waiting for the ordered extent to complete. This left a short time window where if some other task attempts to start the writeout for the same block group cache it can attempt to add a new ordered extent, starting at the same offset (0) before the previous one is removed from the ordered tree, causing an ordered tree panic (calls BUG()). This normally doesn't happen in other write paths, such as buffered writes or direct IO writes for regular files, since before marking page ranges dirty we lock the ranges and wait for any ordered extents within the range to complete first. Fix this by making btrfs_wait_ordered_range() not return immediately if it gets an error from the writeback, waiting for all ordered extents to complete first. This issue happened often when running the fstest btrfs/088 and it's easy to trigger it by running in a loop until the panic happens: for ((i = 1; i <= 10000; i++)) do ./check btrfs/088 ; done [17156.862573] BTRFS critical (device sdc): panic in ordered_data_tree_panic:70: Inconsistency in ordered tree at offset 0 (errno=-17 Object already exists) [17156.864052] ------------[ cut here ]------------ [17156.864052] kernel BUG at fs/btrfs/ordered-data.c:70! (...) [17156.864052] Call Trace: [17156.864052] [<ffffffffa03876e3>] btrfs_add_ordered_extent+0x12/0x14 [btrfs] [17156.864052] [<ffffffffa03787e2>] run_delalloc_nocow+0x5bf/0x747 [btrfs] [17156.864052] [<ffffffffa03789ff>] run_delalloc_range+0x95/0x353 [btrfs] [17156.864052] [<ffffffffa038b7fe>] writepage_delalloc.isra.16+0xb9/0x13f [btrfs] [17156.864052] [<ffffffffa038d75b>] __extent_writepage+0x129/0x1f7 [btrfs] [17156.864052] [<ffffffffa038da5a>] extent_write_cache_pages.isra.15.constprop.28+0x231/0x2f4 [btrfs] [17156.864052] [<ffffffff810ad2af>] ? __module_text_address+0x12/0x59 [17156.864052] [<ffffffff8107d33d>] ? trace_hardirqs_on+0xd/0xf [17156.864052] [<ffffffffa038df76>] extent_writepages+0x4b/0x5c [btrfs] [17156.864052] [<ffffffff81144431>] ? kmem_cache_free+0x9b/0xce [17156.864052] [<ffffffffa0376a46>] ? btrfs_submit_direct+0x3fc/0x3fc [btrfs] [17156.864052] [<ffffffffa0389cd6>] ? free_extent_state+0x8c/0xc1 [btrfs] [17156.864052] [<ffffffffa0374871>] btrfs_writepages+0x28/0x2a [btrfs] [17156.864052] [<ffffffff8110c4c8>] do_writepages+0x23/0x2c [17156.864052] [<ffffffff81102f36>] __filemap_fdatawrite_range+0x5a/0x61 [17156.864052] [<ffffffff81102f6e>] filemap_fdatawrite_range+0x13/0x15 [17156.864052] [<ffffffffa0383ef7>] btrfs_fdatawrite_range+0x21/0x48 [btrfs] [17156.864052] [<ffffffffa03ab89e>] __btrfs_write_out_cache.isra.14+0x2d9/0x3a7 [btrfs] [17156.864052] [<ffffffffa03ac1ab>] ? btrfs_write_out_cache+0x41/0xdc [btrfs] [17156.864052] [<ffffffffa03ac1fd>] btrfs_write_out_cache+0x93/0xdc [btrfs] [17156.864052] [<ffffffffa0363847>] ? btrfs_start_dirty_block_groups+0x13a/0x2b2 [btrfs] [17156.864052] [<ffffffffa03638e6>] btrfs_start_dirty_block_groups+0x1d9/0x2b2 [btrfs] [17156.864052] [<ffffffff8107d33d>] ? trace_hardirqs_on+0xd/0xf [17156.864052] [<ffffffffa037209e>] btrfs_commit_transaction+0x130/0x9c9 [btrfs] [17156.864052] [<ffffffffa034c748>] btrfs_sync_fs+0xe1/0x12d [btrfs] Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com> |
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e43699d4b4 |
Btrfs: fix crash after inode cache writeback failure
If the writeback of an inode cache failed we were unnecessarilly attempting to release again the delalloc metadata that we previously reserved. However attempting to do this a second time triggers an assertion at drop_outstanding_extent() because we have no more outstanding extents for our inode cache's inode. If we were able to start writeback of the cache the reserved metadata space is released at btrfs_finished_ordered_io(), even if an error happens during writeback. So make sure we don't repeat the metadata space release if writeback started for our inode cache. This issue was trivial to reproduce by running the fstest btrfs/088 with "-o inode_cache", which triggered the assertion leading to a BUG() call and requiring a reboot in order to run the remaining fstests. Trace produced by btrfs/088: [255289.385904] BTRFS: assertion failed: BTRFS_I(inode)->outstanding_extents >= num_extents, file: fs/btrfs/extent-tree.c, line: 5276 [255289.388094] ------------[ cut here ]------------ [255289.389184] kernel BUG at fs/btrfs/ctree.h:4057! [255289.390125] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC (...) [255289.392068] Call Trace: [255289.392068] [<ffffffffa035e774>] drop_outstanding_extent+0x3d/0x6d [btrfs] [255289.392068] [<ffffffffa0364988>] btrfs_delalloc_release_metadata+0x54/0xe3 [btrfs] [255289.392068] [<ffffffffa03b4174>] btrfs_write_out_ino_cache+0x95/0xad [btrfs] [255289.392068] [<ffffffffa036f5c4>] btrfs_save_ino_cache+0x275/0x2dc [btrfs] [255289.392068] [<ffffffffa03e2d83>] commit_fs_roots.isra.12+0xaa/0x137 [btrfs] [255289.392068] [<ffffffff8107d33d>] ? trace_hardirqs_on+0xd/0xf [255289.392068] [<ffffffffa037841f>] ? btrfs_commit_transaction+0x4b1/0x9c9 [btrfs] [255289.392068] [<ffffffff814351a4>] ? _raw_spin_unlock+0x32/0x46 [255289.392068] [<ffffffffa037842e>] btrfs_commit_transaction+0x4c0/0x9c9 [btrfs] (...) Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com> |
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af6472881a |
Merge branch 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fix from Chris Mason: "When an arm user reported crashes near page_address(page) in my new code, it became clear that I can't be trusted with GFP masks. Filipe beat me to the patch, and I'll just be in the corner with my dunce cap on" * 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: fix wrong mapping flags for free space inode |