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* btrfs: abort transaction after failed inode updates in create_subvolJosef Bacik2019-12-311-2/+8
| | | | | | | | | | | | | | | [ Upstream commit c7e54b5102bf3614cadb9ca32d7be73bad6cecf0 ] We can just abort the transaction here, and in fact do that for every other failure in this function except these two cases. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: return error pointer from alloc_test_extent_bufferDan Carpenter2019-12-313-7/+9
| | | | | | | | | | | | | | | | | [ Upstream commit b6293c821ea8fa2a631a2112cd86cd435effeb8b ] Callers of alloc_test_extent_buffer have not correctly interpreted the return value as error pointer, as alloc_test_extent_buffer should behave as alloc_extent_buffer. The self-tests were unaffected but btrfs_find_create_tree_block could call both functions and that would cause problems up in the call chain. Fixes: faa2dbf004e8 ("Btrfs: add sanity tests for new qgroup accounting code") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: don't prematurely free work in scrub_missing_raid56_worker()Omar Sandoval2019-12-311-2/+1
| | | | | | | | | | | | | | | | [ Upstream commit 57d4f0b863272ba04ba85f86bfdc0f976f0af91c ] Currently, scrub_missing_raid56_worker() puts and potentially frees sblock (which embeds the work item) and then submits a bio through scrub_wr_submit(). This is another potential instance of the bug in "btrfs: don't prematurely free work in run_ordered_work()". Fix it by dropping the reference after we submit the bio. Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: don't prematurely free work in reada_start_machine_worker()Omar Sandoval2019-12-311-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit e732fe95e4cad35fc1df278c23a32903341b08b3 ] Currently, reada_start_machine_worker() frees the reada_machine_work and then calls __reada_start_machine() to do readahead. This is another potential instance of the bug in "btrfs: don't prematurely free work in run_ordered_work()". There _might_ already be a deadlock here: reada_start_machine_worker() can depend on itself through stacked filesystems (__read_start_machine() -> reada_start_machine_dev() -> reada_tree_block_flagged() -> read_extent_buffer_pages() -> submit_one_bio() -> btree_submit_bio_hook() -> btrfs_map_bio() -> submit_stripe_bio() -> submit_bio() onto a loop device can trigger readahead on the lower filesystem). Either way, let's fix it by freeing the work at the end. Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: don't prematurely free work in run_ordered_work()Omar Sandoval2019-12-311-12/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit c495dcd6fbe1dce51811a76bb85b4675f6494938 ] We hit the following very strange deadlock on a system with Btrfs on a loop device backed by another Btrfs filesystem: 1. The top (loop device) filesystem queues an async_cow work item from cow_file_range_async(). We'll call this work X. 2. Worker thread A starts work X (normal_work_helper()). 3. Worker thread A executes the ordered work for the top filesystem (run_ordered_work()). 4. Worker thread A finishes the ordered work for work X and frees X (work->ordered_free()). 5. Worker thread A executes another ordered work and gets blocked on I/O to the bottom filesystem (still in run_ordered_work()). 6. Meanwhile, the bottom filesystem allocates and queues an async_cow work item which happens to be the recently-freed X. 7. The workqueue code sees that X is already being executed by worker thread A, so it schedules X to be executed _after_ worker thread A finishes (see the find_worker_executing_work() call in process_one_work()). Now, the top filesystem is waiting for I/O on the bottom filesystem, but the bottom filesystem is waiting for the top filesystem to finish, so we deadlock. This happens because we are breaking the workqueue assumption that a work item cannot be recycled while it still depends on other work. Fix it by waiting to free the work item until we are done with all of the related ordered work. P.S.: One might ask why the workqueue code doesn't try to detect a recycled work item. It actually does try by checking whether the work item has the same work function (find_worker_executing_work()), but in our case the function is the same. This is the only key that the workqueue code has available to compare, short of adding an additional, layer-violating "custom key". Considering that we're the only ones that have ever hit this, we should just play by the rules. Unfortunately, we haven't been able to create a minimal reproducer other than our full container setup using a compress-force=zstd filesystem on top of another compress-force=zstd filesystem. Suggested-by: Tejun Heo <tj@kernel.org> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: don't prematurely free work in end_workqueue_fn()Omar Sandoval2019-12-311-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 9be490f1e15c34193b1aae17da58e14dd9f55a95 ] Currently, end_workqueue_fn() frees the end_io_wq entry (which embeds the work item) and then calls bio_endio(). This is another potential instance of the bug in "btrfs: don't prematurely free work in run_ordered_work()". In particular, the endio call may depend on other work items. For example, btrfs_end_dio_bio() can call btrfs_subio_endio_read() -> __btrfs_correct_data_nocsum() -> dio_read_error() -> submit_dio_repair_bio(), which submits a bio that is also completed through a end_workqueue_fn() work item. However, __btrfs_correct_data_nocsum() waits for the newly submitted bio to complete, thus it depends on another work item. This example currently usually works because we use different workqueue helper functions for BTRFS_WQ_ENDIO_DATA and BTRFS_WQ_ENDIO_DIO_REPAIR. However, it may deadlock with stacked filesystems and is fragile overall. The proper fix is to free the work item at the very end of the work function, so let's do that. Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* Btrfs: fix removal logic of the tree mod log that leads to use-after-free issuesFilipe Manana2019-12-311-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 6609fee8897ac475378388238456c84298bff802 upstream. When a tree mod log user no longer needs to use the tree it calls btrfs_put_tree_mod_seq() to remove itself from the list of users and delete all no longer used elements of the tree's red black tree, which should be all elements with a sequence number less then our equals to the caller's sequence number. However the logic is broken because it can delete and free elements from the red black tree that have a sequence number greater then the caller's sequence number: 1) At a point in time we have sequence numbers 1, 2, 3 and 4 in the tree mod log; 2) The task which got assigned the sequence number 1 calls btrfs_put_tree_mod_seq(); 3) Sequence number 1 is deleted from the list of sequence numbers; 4) The current minimum sequence number is computed to be the sequence number 2; 5) A task using sequence number 2 is at tree_mod_log_rewind() and gets a pointer to one of its elements from the red black tree through a call to tree_mod_log_search(); 6) The task with sequence number 1 iterates the red black tree of tree modification elements and deletes (and frees) all elements with a sequence number less then or equals to 2 (the computed minimum sequence number) - it ends up only leaving elements with sequence numbers of 3 and 4; 7) The task with sequence number 2 now uses the pointer to its element, already freed by the other task, at __tree_mod_log_rewind(), resulting in a use-after-free issue. When CONFIG_DEBUG_PAGEALLOC=y it produces a trace like the following: [16804.546854] general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI [16804.547451] CPU: 0 PID: 28257 Comm: pool Tainted: G W 5.4.0-rc8-btrfs-next-51 #1 [16804.548059] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014 [16804.548666] RIP: 0010:rb_next+0x16/0x50 (...) [16804.550581] RSP: 0018:ffffb948418ef9b0 EFLAGS: 00010202 [16804.551227] RAX: 6b6b6b6b6b6b6b6b RBX: ffff90e0247f6600 RCX: 6b6b6b6b6b6b6b6b [16804.551873] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff90e0247f6600 [16804.552504] RBP: ffff90dffe0d4688 R08: 0000000000000001 R09: 0000000000000000 [16804.553136] R10: ffff90dffa4a0040 R11: 0000000000000000 R12: 000000000000002e [16804.553768] R13: ffff90e0247f6600 R14: 0000000000001663 R15: ffff90dff77862b8 [16804.554399] FS: 00007f4b197ae700(0000) GS:ffff90e036a00000(0000) knlGS:0000000000000000 [16804.555039] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [16804.555683] CR2: 00007f4b10022000 CR3: 00000002060e2004 CR4: 00000000003606f0 [16804.556336] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [16804.556968] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [16804.557583] Call Trace: [16804.558207] __tree_mod_log_rewind+0xbf/0x280 [btrfs] [16804.558835] btrfs_search_old_slot+0x105/0xd00 [btrfs] [16804.559468] resolve_indirect_refs+0x1eb/0xc70 [btrfs] [16804.560087] ? free_extent_buffer.part.19+0x5a/0xc0 [btrfs] [16804.560700] find_parent_nodes+0x388/0x1120 [btrfs] [16804.561310] btrfs_check_shared+0x115/0x1c0 [btrfs] [16804.561916] ? extent_fiemap+0x59d/0x6d0 [btrfs] [16804.562518] extent_fiemap+0x59d/0x6d0 [btrfs] [16804.563112] ? __might_fault+0x11/0x90 [16804.563706] do_vfs_ioctl+0x45a/0x700 [16804.564299] ksys_ioctl+0x70/0x80 [16804.564885] ? trace_hardirqs_off_thunk+0x1a/0x20 [16804.565461] __x64_sys_ioctl+0x16/0x20 [16804.566020] do_syscall_64+0x5c/0x250 [16804.566580] entry_SYSCALL_64_after_hwframe+0x49/0xbe [16804.567153] RIP: 0033:0x7f4b1ba2add7 (...) [16804.568907] RSP: 002b:00007f4b197adc88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [16804.569513] RAX: ffffffffffffffda RBX: 00007f4b100210d8 RCX: 00007f4b1ba2add7 [16804.570133] RDX: 00007f4b100210d8 RSI: 00000000c020660b RDI: 0000000000000003 [16804.570726] RBP: 000055de05a6cfe0 R08: 0000000000000000 R09: 00007f4b197add44 [16804.571314] R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4b197add48 [16804.571905] R13: 00007f4b197add40 R14: 00007f4b100210d0 R15: 00007f4b197add50 (...) [16804.575623] ---[ end trace 87317359aad4ba50 ]--- Fix this by making btrfs_put_tree_mod_seq() skip deletion of elements that have a sequence number equals to the computed minimum sequence number, and not just elements with a sequence number greater then that minimum. Fixes: bd989ba359f2ac ("Btrfs: add tree modification log functions") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: handle ENOENT in btrfs_uuid_tree_iterateJosef Bacik2019-12-311-0/+2
| | | | | | | | | | | | | | | | | | commit 714cd3e8cba6841220dce9063a7388a81de03825 upstream. If we get an -ENOENT back from btrfs_uuid_iter_rem when iterating the uuid tree we'll just continue and do btrfs_next_item(). However we've done a btrfs_release_path() at this point and no longer have a valid path. So increment the key and go back and do a normal search. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: do not leak reloc root if we fail to read the fs rootJosef Bacik2019-12-311-0/+1
| | | | | | | | | | | | | | | | | | | commit ca1aa2818a53875cfdd175fb5e9a2984e997cce9 upstream. If we fail to read the fs root corresponding with a reloc root we'll just break out and free the reloc roots. But we remove our current reloc_root from this list higher up, which means we'll leak this reloc_root. Fix this by adding ourselves back to the reloc_roots list so we are properly cleaned up. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: skip log replay on orphaned rootsJosef Bacik2019-12-311-2/+21
| | | | | | | | | | | | | | | | | | | commit 9bc574de590510eff899c3ca8dbaf013566b5efe upstream. My fsstress modifications coupled with generic/475 uncovered a failure to mount and replay the log if we hit a orphaned root. We do not want to replay the log for an orphan root, but it's completely legitimate to have an orphaned root with a log attached. Fix this by simply skipping replaying the log. We still need to pin it's root node so that we do not overwrite it while replaying other logs, as we re-read the log root at every stage of the replay. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: do not call synchronize_srcu() in inode_tree_delJosef Bacik2019-12-311-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit f72ff01df9cf5db25c76674cac16605992d15467 upstream. Testing with the new fsstress uncovered a pretty nasty deadlock with lookup and snapshot deletion. Process A unlink -> final iput -> inode_tree_del -> synchronize_srcu(subvol_srcu) Process B btrfs_lookup <- srcu_read_lock() acquired here -> btrfs_iget -> find inode that has I_FREEING set -> __wait_on_freeing_inode() We're holding the srcu_read_lock() while doing the iget in order to make sure our fs root doesn't go away, and then we are waiting for the inode to finish freeing. However because the free'ing process is doing a synchronize_srcu() we deadlock. Fix this by dropping the synchronize_srcu() in inode_tree_del(). We don't need people to stop accessing the fs root at this point, we're only adding our empty root to the dead roots list. A larger much more invasive fix is forthcoming to address how we deal with fs roots, but this fixes the immediate problem. Fixes: 76dda93c6ae2 ("Btrfs: add snapshot/subvolume destroy ioctl") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: don't double lock the subvol_sem for rename exchangeJosef Bacik2019-12-311-6/+4
| | | | | | | | | | | | | | | commit 943eb3bf25f4a7b745dd799e031be276aa104d82 upstream. If we're rename exchanging two subvols we'll try to lock this lock twice, which is bad. Just lock once if either of the ino's are subvols. Fixes: cdd1fedf8261 ("btrfs: add support for RENAME_EXCHANGE and RENAME_WHITEOUT") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: record all roots for rename exchange on a subvolJosef Bacik2019-12-171-0/+3
| | | | | | | | | | | | | | | | | | | | | | | commit 3e1740993e43116b3bc71b0aad1e6872f6ccf341 upstream. Testing with the new fsstress support for subvolumes uncovered a pretty bad problem with rename exchange on subvolumes. We're modifying two different subvolumes, but we only start the transaction on one of them, so the other one is not added to the dirty root list. This is caught by btrfs_cow_block() with a warning because the root has not been updated, however if we do not modify this root again we'll end up pointing at an invalid root because the root item is never updated. Fix this by making sure we add the destination root to the trans list, the same as we do with normal renames. This fixes the corruption. Fixes: cdd1fedf8261 ("btrfs: add support for RENAME_EXCHANGE and RENAME_WHITEOUT") CC: stable@vger.kernel.org # 4.9+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Btrfs: send, skip backreference walking for extents with many referencesFilipe Manana2019-12-171-1/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | commit fd0ddbe2509568b00df364156f47561e9f469f15 upstream. Backreference walking, which is used by send to figure if it can issue clone operations instead of write operations, can be very slow and use too much memory when extents have many references. This change simply skips backreference walking when an extent has more than 64 references, in which case we fallback to a write operation instead of a clone operation. This limit is conservative and in practice I observed no signicant slowdown with up to 100 references and still low memory usage up to that limit. This is a temporary workaround until there are speedups in the backref walking code, and as such it does not attempt to add extra interfaces or knobs to tweak the threshold. Reported-by: Atemu <atemu.main@gmail.com> Link: https://lore.kernel.org/linux-btrfs/CAE4GHgkvqVADtS4AzcQJxo0Q1jKQgKaW3JGp3SGdoinVo=C9eQ@mail.gmail.com/T/#me55dc0987f9cc2acaa54372ce0492c65782be3fa CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: Remove btrfs_bio::flags memberQu Wenruo2019-12-171-1/+0
| | | | | | | | | | | | | | | | | | commit 34b127aecd4fe8e6a3903e10f204a7b7ffddca22 upstream. The last user of btrfs_bio::flags was removed in commit 326e1dbb5736 ("block: remove management of bi_remaining when restoring original bi_end_io"), remove it. (Tagged for stable as the structure is heavily used and space savings are desirable.) CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Btrfs: fix negative subv_writers counter and data space leak after buffered ↵Filipe Manana2019-12-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | write commit a0e248bb502d5165b3314ac3819e888fdcdf7d9f upstream. When doing a buffered write it's possible to leave the subv_writers counter of the root, used for synchronization between buffered nocow writers and snapshotting. This happens in an exceptional case like the following: 1) We fail to allocate data space for the write, since there's not enough available data space nor enough unallocated space for allocating a new data block group; 2) Because of that failure, we try to go to NOCOW mode, which succeeds and therefore we set the local variable 'only_release_metadata' to true and set the root's sub_writers counter to 1 through the call to btrfs_start_write_no_snapshotting() made by check_can_nocow(); 3) The call to btrfs_copy_from_user() returns zero, which is very unlikely to happen but not impossible; 4) No pages are copied because btrfs_copy_from_user() returned zero; 5) We call btrfs_end_write_no_snapshotting() which decrements the root's subv_writers counter to 0; 6) We don't set 'only_release_metadata' back to 'false' because we do it only if 'copied', the value returned by btrfs_copy_from_user(), is greater than zero; 7) On the next iteration of the while loop, which processes the same page range, we are now able to allocate data space for the write (we got enough data space released in the meanwhile); 8) After this if we fail at btrfs_delalloc_reserve_metadata(), because now there isn't enough free metadata space, or in some other place further below (prepare_pages(), lock_and_cleanup_extent_if_need(), btrfs_dirty_pages()), we break out of the while loop with 'only_release_metadata' having a value of 'true'; 9) Because 'only_release_metadata' is 'true' we end up decrementing the root's subv_writers counter to -1 (through a call to btrfs_end_write_no_snapshotting()), and we also end up not releasing the data space previously reserved through btrfs_check_data_free_space(). As a consequence the mechanism for synchronizing NOCOW buffered writes with snapshotting gets broken. Fix this by always setting 'only_release_metadata' to false at the start of each iteration. Fixes: 8257b2dc3c1a ("Btrfs: introduce btrfs_{start, end}_nocow_write() for each subvolume") Fixes: 7ee9e4405f26 ("Btrfs: check if we can nocow if we don't have data space") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: use refcount_inc_not_zero in kill_all_nodesJosef Bacik2019-12-171-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit baf320b9d531f1cfbf64c60dd155ff80a58b3796 upstream. We hit the following warning while running down a different problem [ 6197.175850] ------------[ cut here ]------------ [ 6197.185082] refcount_t: underflow; use-after-free. [ 6197.194704] WARNING: CPU: 47 PID: 966 at lib/refcount.c:190 refcount_sub_and_test_checked+0x53/0x60 [ 6197.521792] Call Trace: [ 6197.526687] __btrfs_release_delayed_node+0x76/0x1c0 [ 6197.536615] btrfs_kill_all_delayed_nodes+0xec/0x130 [ 6197.546532] ? __btrfs_btree_balance_dirty+0x60/0x60 [ 6197.556482] btrfs_clean_one_deleted_snapshot+0x71/0xd0 [ 6197.566910] cleaner_kthread+0xfa/0x120 [ 6197.574573] kthread+0x111/0x130 [ 6197.581022] ? kthread_create_on_node+0x60/0x60 [ 6197.590086] ret_from_fork+0x1f/0x30 [ 6197.597228] ---[ end trace 424bb7ae00509f56 ]--- This is because the free side drops the ref without the lock, and then takes the lock if our refcount is 0. So you can have nodes on the tree that have a refcount of 0. Fix this by zero'ing out that element in our temporary array so we don't try to kill it again. CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> [ add comment ] Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: check page->mapping when loading free space cacheJosef Bacik2019-12-171-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 3797136b626ad4b6582223660c041efdea8f26b2 upstream. While testing 5.2 we ran into the following panic [52238.017028] BUG: kernel NULL pointer dereference, address: 0000000000000001 [52238.105608] RIP: 0010:drop_buffers+0x3d/0x150 [52238.304051] Call Trace: [52238.308958] try_to_free_buffers+0x15b/0x1b0 [52238.317503] shrink_page_list+0x1164/0x1780 [52238.325877] shrink_inactive_list+0x18f/0x3b0 [52238.334596] shrink_node_memcg+0x23e/0x7d0 [52238.342790] ? do_shrink_slab+0x4f/0x290 [52238.350648] shrink_node+0xce/0x4a0 [52238.357628] balance_pgdat+0x2c7/0x510 [52238.365135] kswapd+0x216/0x3e0 [52238.371425] ? wait_woken+0x80/0x80 [52238.378412] ? balance_pgdat+0x510/0x510 [52238.386265] kthread+0x111/0x130 [52238.392727] ? kthread_create_on_node+0x60/0x60 [52238.401782] ret_from_fork+0x1f/0x30 The page we were trying to drop had a page->private, but had no page->mapping and so called drop_buffers, assuming that we had a buffer_head on the page, and then panic'ed trying to deref 1, which is our page->private for data pages. This is happening because we're truncating the free space cache while we're trying to load the free space cache. This isn't supposed to happen, and I'll fix that in a followup patch. However we still shouldn't allow those sort of mistakes to result in messing with pages that do not belong to us. So add the page->mapping check to verify that we still own this page after dropping and re-acquiring the page lock. This page being unlocked as: btrfs_readpage extent_read_full_page __extent_read_full_page __do_readpage if (!nr) unlock_page <-- nr can be 0 only if submit_extent_page returns an error CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> [ add callchain ] Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: only track ref_heads in delayed_ref_updatesJosef Bacik2019-12-051-3/+0
| | | | | | | | | | | | | | | | | | | [ Upstream commit 158ffa364bf723fa1ef128060646d23dc3942994 ] We use this number to figure out how many delayed refs to run, but __btrfs_run_delayed_refs really only checks every time we need a new delayed ref head, so we always run at least one ref head completely no matter what the number of items on it. Fix the accounting to only be adjusted when we add/remove a ref head. In addition to using this number to limit the number of delayed refs run, a future patch is also going to use it to calculate the amount of space required for delayed refs space reservation. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: avoid link error with CONFIG_NO_AUTO_INLINEArnd Bergmann2019-12-011-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 7e17916b35797396f681a3270245fd29c1e4c250 ] Note: this patch fixes a problem in a feature outside of btrfs ("kernel hacking: add a config option to disable compiler auto-inlining") and is applied ahead of time due to cross-subsystem dependencies. On 32-bit ARM with gcc-8, I see a link error with the addition of the CONFIG_NO_AUTO_INLINE option: fs/btrfs/super.o: In function `btrfs_statfs': super.c:(.text+0x67b8): undefined reference to `__aeabi_uldivmod' super.c:(.text+0x67fc): undefined reference to `__aeabi_uldivmod' super.c:(.text+0x6858): undefined reference to `__aeabi_uldivmod' super.c:(.text+0x6920): undefined reference to `__aeabi_uldivmod' super.c:(.text+0x693c): undefined reference to `__aeabi_uldivmod' fs/btrfs/super.o:super.c:(.text+0x6958): more undefined references to `__aeabi_uldivmod' follow So far this is the only file that shows the behavior, so I'd propose to just work around it by marking the functions as 'static inline' that normally get inlined here. The reference to __aeabi_uldivmod comes from a div_u64() which has an optimization for a constant division that uses a straight '/' operator when the result should be known to the compiler. My interpretation is that as we turn off inlining, gcc still expects the result to be constant but fails to use that constant value. Link: https://lkml.kernel.org/r/20181103153941.1881966-1-arnd@arndb.de Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Changbin Du <changbin.du@gmail.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> [ add the note ] Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: handle error of get_old_rootNikolay Borisov2019-12-011-0/+4
| | | | | | | | | | | | | | | | | [ Upstream commit 315bed43fea532650933e7bba316a7601d439edf ] In btrfs_search_old_slot get_old_root is always used with the assumption it cannot fail. However, this is not true in rare circumstance it can fail and return null. This will lead to null point dereference when the header is read. Fix this by checking the return value and properly handling NULL by setting ret to -EIO and returning gracefully. Coverity-id: 1087503 Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: block-group: Fix a memory leak due to missing btrfs_put_block_group()Qu Wenruo2019-10-291-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | commit 4b654acdae850f48b8250b9a578a4eaa518c7a6f upstream. In btrfs_read_block_groups(), if we have an invalid block group which has mixed type (DATA|METADATA) while the fs doesn't have MIXED_GROUPS feature, we error out without freeing the block group cache. This patch will add the missing btrfs_put_block_group() to prevent memory leak. Note for stable backports: the file to patch in versions <= 5.3 is fs/btrfs/extent-tree.c Fixes: 49303381f19a ("Btrfs: bail out if block group has different mixed flag") CC: stable@vger.kernel.org # 4.9+ Reviewed-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: fix incorrect updating of log root treeJosef Bacik2019-10-171-9/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 4203e968947071586a98b5314fd7ffdea3b4f971 upstream. We've historically had reports of being unable to mount file systems because the tree log root couldn't be read. Usually this is the "parent transid failure", but could be any of the related errors, including "fsid mismatch" or "bad tree block", depending on which block got allocated. The modification of the individual log root items are serialized on the per-log root root_mutex. This means that any modification to the per-subvol log root_item is completely protected. However we update the root item in the log root tree outside of the log root tree log_mutex. We do this in order to allow multiple subvolumes to be updated in each log transaction. This is problematic however because when we are writing the log root tree out we update the super block with the _current_ log root node information. Since these two operations happen independently of each other, you can end up updating the log root tree in between writing out the dirty blocks and setting the super block to point at the current root. This means we'll point at the new root node that hasn't been written out, instead of the one we should be pointing at. Thus whatever garbage or old block we end up pointing at complains when we mount the file system later and try to replay the log. Fix this by copying the log's root item into a local root item copy. Then once we're safely under the log_root_tree->log_mutex we update the root item in the log_root_tree. This way we do not modify the log_root_tree while we're committing it, fixing the problem. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Chris Mason <clm@fb.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Btrfs: fix race setting up and completing qgroup rescan workersFilipe Manana2019-10-051-14/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 13fc1d271a2e3ab8a02071e711add01fab9271f6 ] There is a race between setting up a qgroup rescan worker and completing a qgroup rescan worker that can lead to callers of the qgroup rescan wait ioctl to either not wait for the rescan worker to complete or to hang forever due to missing wake ups. The following diagram shows a sequence of steps that illustrates the race. CPU 1 CPU 2 CPU 3 btrfs_ioctl_quota_rescan() btrfs_qgroup_rescan() qgroup_rescan_init() mutex_lock(&fs_info->qgroup_rescan_lock) spin_lock(&fs_info->qgroup_lock) fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN init_completion( &fs_info->qgroup_rescan_completion) fs_info->qgroup_rescan_running = true mutex_unlock(&fs_info->qgroup_rescan_lock) spin_unlock(&fs_info->qgroup_lock) btrfs_init_work() --> starts the worker btrfs_qgroup_rescan_worker() mutex_lock(&fs_info->qgroup_rescan_lock) fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN mutex_unlock(&fs_info->qgroup_rescan_lock) starts transaction, updates qgroup status item, etc btrfs_ioctl_quota_rescan() btrfs_qgroup_rescan() qgroup_rescan_init() mutex_lock(&fs_info->qgroup_rescan_lock) spin_lock(&fs_info->qgroup_lock) fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN init_completion( &fs_info->qgroup_rescan_completion) fs_info->qgroup_rescan_running = true mutex_unlock(&fs_info->qgroup_rescan_lock) spin_unlock(&fs_info->qgroup_lock) btrfs_init_work() --> starts another worker mutex_lock(&fs_info->qgroup_rescan_lock) fs_info->qgroup_rescan_running = false mutex_unlock(&fs_info->qgroup_rescan_lock) complete_all(&fs_info->qgroup_rescan_completion) Before the rescan worker started by the task at CPU 3 completes, if another task calls btrfs_ioctl_quota_rescan(), it will get -EINPROGRESS because the flag BTRFS_QGROUP_STATUS_FLAG_RESCAN is set at fs_info->qgroup_flags, which is expected and correct behaviour. However if other task calls btrfs_ioctl_quota_rescan_wait() before the rescan worker started by the task at CPU 3 completes, it will return immediately without waiting for the new rescan worker to complete, because fs_info->qgroup_rescan_running is set to false by CPU 2. This race is making test case btrfs/171 (from fstests) to fail often: btrfs/171 9s ... - output mismatch (see /home/fdmanana/git/hub/xfstests/results//btrfs/171.out.bad) # --- tests/btrfs/171.out 2018-09-16 21:30:48.505104287 +0100 # +++ /home/fdmanana/git/hub/xfstests/results//btrfs/171.out.bad 2019-09-19 02:01:36.938486039 +0100 # @@ -1,2 +1,3 @@ # QA output created by 171 # +ERROR: quota rescan failed: Operation now in progress # Silence is golden # ... # (Run 'diff -u /home/fdmanana/git/hub/xfstests/tests/btrfs/171.out /home/fdmanana/git/hub/xfstests/results//btrfs/171.out.bad' to see the entire diff) That is because the test calls the btrfs-progs commands "qgroup quota rescan -w", "qgroup assign" and "qgroup remove" in a sequence that makes calls to the rescan start ioctl fail with -EINPROGRESS (note the "btrfs" commands 'qgroup assign' and 'qgroup remove' often call the rescan start ioctl after calling the qgroup assign ioctl, btrfs_ioctl_qgroup_assign()), since previous waits didn't actually wait for a rescan worker to complete. Another problem the race can cause is missing wake ups for waiters, since the call to complete_all() happens outside a critical section and after clearing the flag BTRFS_QGROUP_STATUS_FLAG_RESCAN. In the sequence diagram above, if we have a waiter for the first rescan task (executed by CPU 2), then fs_info->qgroup_rescan_completion.wait is not empty, and if after the rescan worker clears BTRFS_QGROUP_STATUS_FLAG_RESCAN and before it calls complete_all() against fs_info->qgroup_rescan_completion, the task at CPU 3 calls init_completion() against fs_info->qgroup_rescan_completion which re-initilizes its wait queue to an empty queue, therefore causing the rescan worker at CPU 2 to call complete_all() against an empty queue, never waking up the task waiting for that rescan worker. Fix this by clearing BTRFS_QGROUP_STATUS_FLAG_RESCAN and setting fs_info->qgroup_rescan_running to false in the same critical section, delimited by the mutex fs_info->qgroup_rescan_lock, as well as doing the call to complete_all() in that same critical section. This gives the protection needed to avoid rescan wait ioctl callers not waiting for a running rescan worker and the lost wake ups problem, since setting that rescan flag and boolean as well as initializing the wait queue is done already in a critical section delimited by that mutex (at qgroup_rescan_init()). Fixes: 57254b6ebce4ce ("Btrfs: add ioctl to wait for qgroup rescan completion") Fixes: d2c609b834d62f ("btrfs: properly track when rescan worker is running") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: qgroup: Drop quota_root and fs_info parameters from ↵Lu Fengqi2019-10-051-6/+6
| | | | | | | | | | | | update_qgroup_status_item [ Upstream commit 2e980acdd829742966c6a7e565ef3382c0717295 ] They can be fetched from the transaction handle. Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: qgroup: Fix the wrong target io_tree when freeing reserved data spaceQu Wenruo2019-10-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit bab32fc069ce8829c416e8737c119f62a57970f9 upstream. [BUG] Under the following case with qgroup enabled, if some error happened after we have reserved delalloc space, then in error handling path, we could cause qgroup data space leakage: From btrfs_truncate_block() in inode.c: ret = btrfs_delalloc_reserve_space(inode, &data_reserved, block_start, blocksize); if (ret) goto out; again: page = find_or_create_page(mapping, index, mask); if (!page) { btrfs_delalloc_release_space(inode, data_reserved, block_start, blocksize, true); btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize, true); ret = -ENOMEM; goto out; } [CAUSE] In the above case, btrfs_delalloc_reserve_space() will call btrfs_qgroup_reserve_data() and mark the io_tree range with EXTENT_QGROUP_RESERVED flag. In the error handling path, we have the following call stack: btrfs_delalloc_release_space() |- btrfs_free_reserved_data_space() |- btrsf_qgroup_free_data() |- __btrfs_qgroup_release_data(reserved=@reserved, free=1) |- qgroup_free_reserved_data(reserved=@reserved) |- clear_record_extent_bits(); |- freed += changeset.bytes_changed; However due to a completion bug, qgroup_free_reserved_data() will clear EXTENT_QGROUP_RESERVED flag in BTRFS_I(inode)->io_failure_tree, other than the correct BTRFS_I(inode)->io_tree. Since io_failure_tree is never marked with that flag, btrfs_qgroup_free_data() will not free any data reserved space at all, causing a leakage. This type of error handling can only be triggered by errors outside of qgroup code. So EDQUOT error from qgroup can't trigger it. [FIX] Fix the wrong target io_tree. Reported-by: Josef Bacik <josef@toxicpanda.com> Fixes: bc42bda22345 ("btrfs: qgroup: Fix qgroup reserved space underflow by only freeing reserved ranges") CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: Relinquish CPUs in btrfs_compare_treesNikolay Borisov2019-10-051-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 6af112b11a4bc1b560f60a618ac9c1dcefe9836e upstream. When doing any form of incremental send the parent and the child trees need to be compared via btrfs_compare_trees. This can result in long loop chains without ever relinquishing the CPU. This causes softlockup detector to trigger when comparing trees with a lot of items. Example report: watchdog: BUG: soft lockup - CPU#0 stuck for 24s! [snapperd:16153] CPU: 0 PID: 16153 Comm: snapperd Not tainted 5.2.9-1-default #1 openSUSE Tumbleweed (unreleased) Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015 pstate: 40000005 (nZcv daif -PAN -UAO) pc : __ll_sc_arch_atomic_sub_return+0x14/0x20 lr : btrfs_release_extent_buffer_pages+0xe0/0x1e8 [btrfs] sp : ffff00001273b7e0 Call trace: __ll_sc_arch_atomic_sub_return+0x14/0x20 release_extent_buffer+0xdc/0x120 [btrfs] free_extent_buffer.part.0+0xb0/0x118 [btrfs] free_extent_buffer+0x24/0x30 [btrfs] btrfs_release_path+0x4c/0xa0 [btrfs] btrfs_free_path.part.0+0x20/0x40 [btrfs] btrfs_free_path+0x24/0x30 [btrfs] get_inode_info+0xa8/0xf8 [btrfs] finish_inode_if_needed+0xe0/0x6d8 [btrfs] changed_cb+0x9c/0x410 [btrfs] btrfs_compare_trees+0x284/0x648 [btrfs] send_subvol+0x33c/0x520 [btrfs] btrfs_ioctl_send+0x8a0/0xaf0 [btrfs] btrfs_ioctl+0x199c/0x2288 [btrfs] do_vfs_ioctl+0x4b0/0x820 ksys_ioctl+0x84/0xb8 __arm64_sys_ioctl+0x28/0x38 el0_svc_common.constprop.0+0x7c/0x188 el0_svc_handler+0x34/0x90 el0_svc+0x8/0xc Fix this by adding a call to cond_resched at the beginning of the main loop in btrfs_compare_trees. Fixes: 7069830a9e38 ("Btrfs: add btrfs_compare_trees function") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Btrfs: fix use-after-free when using the tree modification logFilipe Manana2019-10-051-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit efad8a853ad2057f96664328a0d327a05ce39c76 upstream. At ctree.c:get_old_root(), we are accessing a root's header owner field after we have freed the respective extent buffer. This results in an use-after-free that can lead to crashes, and when CONFIG_DEBUG_PAGEALLOC is set, results in a stack trace like the following: [ 3876.799331] stack segment: 0000 [#1] SMP DEBUG_PAGEALLOC PTI [ 3876.799363] CPU: 0 PID: 15436 Comm: pool Not tainted 5.3.0-rc3-btrfs-next-54 #1 [ 3876.799385] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014 [ 3876.799433] RIP: 0010:btrfs_search_old_slot+0x652/0xd80 [btrfs] (...) [ 3876.799502] RSP: 0018:ffff9f08c1a2f9f0 EFLAGS: 00010286 [ 3876.799518] RAX: ffff8dd300000000 RBX: ffff8dd85a7a9348 RCX: 000000038da26000 [ 3876.799538] RDX: 0000000000000000 RSI: ffffe522ce368980 RDI: 0000000000000246 [ 3876.799559] RBP: dae1922adadad000 R08: 0000000008020000 R09: ffffe522c0000000 [ 3876.799579] R10: ffff8dd57fd788c8 R11: 000000007511b030 R12: ffff8dd781ddc000 [ 3876.799599] R13: ffff8dd9e6240578 R14: ffff8dd6896f7a88 R15: ffff8dd688cf90b8 [ 3876.799620] FS: 00007f23ddd97700(0000) GS:ffff8dda20200000(0000) knlGS:0000000000000000 [ 3876.799643] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 3876.799660] CR2: 00007f23d4024000 CR3: 0000000710bb0005 CR4: 00000000003606f0 [ 3876.799682] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 3876.799703] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 3876.799723] Call Trace: [ 3876.799735] ? do_raw_spin_unlock+0x49/0xc0 [ 3876.799749] ? _raw_spin_unlock+0x24/0x30 [ 3876.799779] resolve_indirect_refs+0x1eb/0xc80 [btrfs] [ 3876.799810] find_parent_nodes+0x38d/0x1180 [btrfs] [ 3876.799841] btrfs_check_shared+0x11a/0x1d0 [btrfs] [ 3876.799870] ? extent_fiemap+0x598/0x6e0 [btrfs] [ 3876.799895] extent_fiemap+0x598/0x6e0 [btrfs] [ 3876.799913] do_vfs_ioctl+0x45a/0x700 [ 3876.799926] ksys_ioctl+0x70/0x80 [ 3876.799938] ? trace_hardirqs_off_thunk+0x1a/0x20 [ 3876.799953] __x64_sys_ioctl+0x16/0x20 [ 3876.799965] do_syscall_64+0x62/0x220 [ 3876.799977] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 3876.799993] RIP: 0033:0x7f23e0013dd7 (...) [ 3876.800056] RSP: 002b:00007f23ddd96ca8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 3876.800078] RAX: ffffffffffffffda RBX: 00007f23d80210f8 RCX: 00007f23e0013dd7 [ 3876.800099] RDX: 00007f23d80210f8 RSI: 00000000c020660b RDI: 0000000000000003 [ 3876.800626] RBP: 000055fa2a2a2440 R08: 0000000000000000 R09: 00007f23ddd96d7c [ 3876.801143] R10: 00007f23d8022000 R11: 0000000000000246 R12: 00007f23ddd96d80 [ 3876.801662] R13: 00007f23ddd96d78 R14: 00007f23d80210f0 R15: 00007f23ddd96d80 (...) [ 3876.805107] ---[ end trace e53161e179ef04f9 ]--- Fix that by saving the root's header owner field into a local variable before freeing the root's extent buffer, and then use that local variable when needed. Fixes: 30b0463a9394d9 ("Btrfs: fix accessing the root pointer in tree mod log functions") CC: stable@vger.kernel.org # 3.10+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: extent-tree: Make sure we only allocate extents from block groups ↵Qu Wenruo2019-10-051-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | with the same type [ Upstream commit 2a28468e525f3924efed7f29f2bc5a2926e7e19a ] [BUG] With fuzzed image and MIXED_GROUPS super flag, we can hit the following BUG_ON(): kernel BUG at fs/btrfs/delayed-ref.c:491! invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 0 PID: 1849 Comm: sync Tainted: G O 5.2.0-custom #27 RIP: 0010:update_existing_head_ref.cold+0x44/0x46 [btrfs] Call Trace: add_delayed_ref_head+0x20c/0x2d0 [btrfs] btrfs_add_delayed_tree_ref+0x1fc/0x490 [btrfs] btrfs_free_tree_block+0x123/0x380 [btrfs] __btrfs_cow_block+0x435/0x500 [btrfs] btrfs_cow_block+0x110/0x240 [btrfs] btrfs_search_slot+0x230/0xa00 [btrfs] ? __lock_acquire+0x105e/0x1e20 btrfs_insert_empty_items+0x67/0xc0 [btrfs] alloc_reserved_file_extent+0x9e/0x340 [btrfs] __btrfs_run_delayed_refs+0x78e/0x1240 [btrfs] ? kvm_clock_read+0x18/0x30 ? __sched_clock_gtod_offset+0x21/0x50 btrfs_run_delayed_refs.part.0+0x4e/0x180 [btrfs] btrfs_run_delayed_refs+0x23/0x30 [btrfs] btrfs_commit_transaction+0x53/0x9f0 [btrfs] btrfs_sync_fs+0x7c/0x1c0 [btrfs] ? __ia32_sys_fdatasync+0x20/0x20 sync_fs_one_sb+0x23/0x30 iterate_supers+0x95/0x100 ksys_sync+0x62/0xb0 __ia32_sys_sync+0xe/0x20 do_syscall_64+0x65/0x240 entry_SYSCALL_64_after_hwframe+0x49/0xbe [CAUSE] This situation is caused by several factors: - Fuzzed image The extent tree of this fs missed one backref for extent tree root. So we can allocated space from that slot. - MIXED_BG feature Super block has MIXED_BG flag. - No mixed block groups exists All block groups are just regular ones. This makes data space_info->block_groups[] contains metadata block groups. And when we reserve space for data, we can use space in metadata block group. Then we hit the following file operations: - fallocate We need to allocate data extents. find_free_extent() choose to use the metadata block to allocate space from, and choose the space of extent tree root, since its backref is missing. This generate one delayed ref head with is_data = 1. - extent tree update We need to update extent tree at run_delayed_ref time. This generate one delayed ref head with is_data = 0, for the same bytenr of old extent tree root. Then we trigger the BUG_ON(). [FIX] The quick fix here is to check block_group->flags before using it. The problem can only happen for MIXED_GROUPS fs. Regular filesystems won't have space_info with DATA|METADATA flag, and no way to hit the bug. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203255 Reported-by: Jungyeon Yoon <jungyeon.yoon@gmail.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* Btrfs: fix assertion failure during fsync and use of stale transactionFilipe Manana2019-09-191-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 410f954cb1d1c79ae485dd83a175f21954fd87cd upstream. Sometimes when fsync'ing a file we need to log that other inodes exist and when we need to do that we acquire a reference on the inodes and then drop that reference using iput() after logging them. That generally is not a problem except if we end up doing the final iput() (dropping the last reference) on the inode and that inode has a link count of 0, which can happen in a very short time window if the logging path gets a reference on the inode while it's being unlinked. In that case we end up getting the eviction callback, btrfs_evict_inode(), invoked through the iput() call chain which needs to drop all of the inode's items from its subvolume btree, and in order to do that, it needs to join a transaction at the helper function evict_refill_and_join(). However because the task previously started a transaction at the fsync handler, btrfs_sync_file(), it has current->journal_info already pointing to a transaction handle and therefore evict_refill_and_join() will get that transaction handle from btrfs_join_transaction(). From this point on, two different problems can happen: 1) evict_refill_and_join() will often change the transaction handle's block reserve (->block_rsv) and set its ->bytes_reserved field to a value greater than 0. If evict_refill_and_join() never commits the transaction, the eviction handler ends up decreasing the reference count (->use_count) of the transaction handle through the call to btrfs_end_transaction(), and after that point we have a transaction handle with a NULL ->block_rsv (which is the value prior to the transaction join from evict_refill_and_join()) and a ->bytes_reserved value greater than 0. If after the eviction/iput completes the inode logging path hits an error or it decides that it must fallback to a transaction commit, the btrfs fsync handle, btrfs_sync_file(), gets a non-zero value from btrfs_log_dentry_safe(), and because of that non-zero value it tries to commit the transaction using a handle with a NULL ->block_rsv and a non-zero ->bytes_reserved value. This makes the transaction commit hit an assertion failure at btrfs_trans_release_metadata() because ->bytes_reserved is not zero but the ->block_rsv is NULL. The produced stack trace for that is like the following: [192922.917158] assertion failed: !trans->bytes_reserved, file: fs/btrfs/transaction.c, line: 816 [192922.917553] ------------[ cut here ]------------ [192922.917922] kernel BUG at fs/btrfs/ctree.h:3532! [192922.918310] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI [192922.918666] CPU: 2 PID: 883 Comm: fsstress Tainted: G W 5.1.4-btrfs-next-47 #1 [192922.919035] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014 [192922.919801] RIP: 0010:assfail.constprop.25+0x18/0x1a [btrfs] (...) [192922.920925] RSP: 0018:ffffaebdc8a27da8 EFLAGS: 00010286 [192922.921315] RAX: 0000000000000051 RBX: ffff95c9c16a41c0 RCX: 0000000000000000 [192922.921692] RDX: 0000000000000000 RSI: ffff95cab6b16838 RDI: ffff95cab6b16838 [192922.922066] RBP: ffff95c9c16a41c0 R08: 0000000000000000 R09: 0000000000000000 [192922.922442] R10: ffffaebdc8a27e70 R11: 0000000000000000 R12: ffff95ca731a0980 [192922.922820] R13: 0000000000000000 R14: ffff95ca84c73338 R15: ffff95ca731a0ea8 [192922.923200] FS: 00007f337eda4e80(0000) GS:ffff95cab6b00000(0000) knlGS:0000000000000000 [192922.923579] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [192922.923948] CR2: 00007f337edad000 CR3: 00000001e00f6002 CR4: 00000000003606e0 [192922.924329] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [192922.924711] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [192922.925105] Call Trace: [192922.925505] btrfs_trans_release_metadata+0x10c/0x170 [btrfs] [192922.925911] btrfs_commit_transaction+0x3e/0xaf0 [btrfs] [192922.926324] btrfs_sync_file+0x44c/0x490 [btrfs] [192922.926731] do_fsync+0x38/0x60 [192922.927138] __x64_sys_fdatasync+0x13/0x20 [192922.927543] do_syscall_64+0x60/0x1c0 [192922.927939] entry_SYSCALL_64_after_hwframe+0x49/0xbe (...) [192922.934077] ---[ end trace f00808b12068168f ]--- 2) If evict_refill_and_join() decides to commit the transaction, it will be able to do it, since the nested transaction join only increments the transaction handle's ->use_count reference counter and it does not prevent the transaction from getting committed. This means that after eviction completes, the fsync logging path will be using a transaction handle that refers to an already committed transaction. What happens when using such a stale transaction can be unpredictable, we are at least having a use-after-free on the transaction handle itself, since the transaction commit will call kmem_cache_free() against the handle regardless of its ->use_count value, or we can end up silently losing all the updates to the log tree after that iput() in the logging path, or using a transaction handle that in the meanwhile was allocated to another task for a new transaction, etc, pretty much unpredictable what can happen. In order to fix both of them, instead of using iput() during logging, use btrfs_add_delayed_iput(), so that the logging path of fsync never drops the last reference on an inode, that step is offloaded to a safe context (usually the cleaner kthread). The assertion failure issue was sporadically triggered by the test case generic/475 from fstests, which loads the dm error target while fsstress is running, which lead to fsync failing while logging inodes with -EIO errors and then trying later to commit the transaction, triggering the assertion failure. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: correctly validate compression typeJohannes Thumshirn2019-09-193-5/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit aa53e3bfac7205fb3a8815ac1c937fd6ed01b41e upstream. Nikolay reported the following KASAN splat when running btrfs/048: [ 1843.470920] ================================================================== [ 1843.471971] BUG: KASAN: slab-out-of-bounds in strncmp+0x66/0xb0 [ 1843.472775] Read of size 1 at addr ffff888111e369e2 by task btrfs/3979 [ 1843.473904] CPU: 3 PID: 3979 Comm: btrfs Not tainted 5.2.0-rc3-default #536 [ 1843.475009] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 [ 1843.476322] Call Trace: [ 1843.476674] dump_stack+0x7c/0xbb [ 1843.477132] ? strncmp+0x66/0xb0 [ 1843.477587] print_address_description+0x114/0x320 [ 1843.478256] ? strncmp+0x66/0xb0 [ 1843.478740] ? strncmp+0x66/0xb0 [ 1843.479185] __kasan_report+0x14e/0x192 [ 1843.479759] ? strncmp+0x66/0xb0 [ 1843.480209] kasan_report+0xe/0x20 [ 1843.480679] strncmp+0x66/0xb0 [ 1843.481105] prop_compression_validate+0x24/0x70 [ 1843.481798] btrfs_xattr_handler_set_prop+0x65/0x160 [ 1843.482509] __vfs_setxattr+0x71/0x90 [ 1843.483012] __vfs_setxattr_noperm+0x84/0x130 [ 1843.483606] vfs_setxattr+0xac/0xb0 [ 1843.484085] setxattr+0x18c/0x230 [ 1843.484546] ? vfs_setxattr+0xb0/0xb0 [ 1843.485048] ? __mod_node_page_state+0x1f/0xa0 [ 1843.485672] ? _raw_spin_unlock+0x24/0x40 [ 1843.486233] ? __handle_mm_fault+0x988/0x1290 [ 1843.486823] ? lock_acquire+0xb4/0x1e0 [ 1843.487330] ? lock_acquire+0xb4/0x1e0 [ 1843.487842] ? mnt_want_write_file+0x3c/0x80 [ 1843.488442] ? debug_lockdep_rcu_enabled+0x22/0x40 [ 1843.489089] ? rcu_sync_lockdep_assert+0xe/0x70 [ 1843.489707] ? __sb_start_write+0x158/0x200 [ 1843.490278] ? mnt_want_write_file+0x3c/0x80 [ 1843.490855] ? __mnt_want_write+0x98/0xe0 [ 1843.491397] __x64_sys_fsetxattr+0xba/0xe0 [ 1843.492201] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 1843.493201] do_syscall_64+0x6c/0x230 [ 1843.493988] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 1843.495041] RIP: 0033:0x7fa7a8a7707a [ 1843.495819] Code: 48 8b 0d 21 de 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 be 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d ee dd 2b 00 f7 d8 64 89 01 48 [ 1843.499203] RSP: 002b:00007ffcb73bca38 EFLAGS: 00000202 ORIG_RAX: 00000000000000be [ 1843.500210] RAX: ffffffffffffffda RBX: 00007ffcb73bda9d RCX: 00007fa7a8a7707a [ 1843.501170] RDX: 00007ffcb73bda9d RSI: 00000000006dc050 RDI: 0000000000000003 [ 1843.502152] RBP: 00000000006dc050 R08: 0000000000000000 R09: 0000000000000000 [ 1843.503109] R10: 0000000000000002 R11: 0000000000000202 R12: 00007ffcb73bda91 [ 1843.504055] R13: 0000000000000003 R14: 00007ffcb73bda82 R15: ffffffffffffffff [ 1843.505268] Allocated by task 3979: [ 1843.505771] save_stack+0x19/0x80 [ 1843.506211] __kasan_kmalloc.constprop.5+0xa0/0xd0 [ 1843.506836] setxattr+0xeb/0x230 [ 1843.507264] __x64_sys_fsetxattr+0xba/0xe0 [ 1843.507886] do_syscall_64+0x6c/0x230 [ 1843.508429] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 1843.509558] Freed by task 0: [ 1843.510188] (stack is not available) [ 1843.511309] The buggy address belongs to the object at ffff888111e369e0 which belongs to the cache kmalloc-8 of size 8 [ 1843.514095] The buggy address is located 2 bytes inside of 8-byte region [ffff888111e369e0, ffff888111e369e8) [ 1843.516524] The buggy address belongs to the page: [ 1843.517561] page:ffff88813f478d80 refcount:1 mapcount:0 mapping:ffff88811940c300 index:0xffff888111e373b8 compound_mapcount: 0 [ 1843.519993] flags: 0x4404000010200(slab|head) [ 1843.520951] raw: 0004404000010200 ffff88813f48b008 ffff888119403d50 ffff88811940c300 [ 1843.522616] raw: ffff888111e373b8 000000000016000f 00000001ffffffff 0000000000000000 [ 1843.524281] page dumped because: kasan: bad access detected [ 1843.525936] Memory state around the buggy address: [ 1843.526975] ffff888111e36880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 1843.528479] ffff888111e36900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 1843.530138] >ffff888111e36980: fc fc fc fc fc fc fc fc fc fc fc fc 02 fc fc fc [ 1843.531877] ^ [ 1843.533287] ffff888111e36a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 1843.534874] ffff888111e36a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 1843.536468] ================================================================== This is caused by supplying a too short compression value ('lz') in the test-case and comparing it to 'lzo' with strncmp() and a length of 3. strncmp() read past the 'lz' when looking for the 'o' and thus caused an out-of-bounds read. Introduce a new check 'btrfs_compress_is_valid_type()' which not only checks the user-supplied value against known compression types, but also employs checks for too short values. Reported-by: Nikolay Borisov <nborisov@suse.com> Fixes: 272e5326c783 ("btrfs: prop: fix vanished compression property after failed set") CC: stable@vger.kernel.org # 5.1+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: compression: add helper for type to string conversionDavid Sterba2019-09-192-0/+17
| | | | | | | | | | | commit e128f9c3f7242318e1c76d204c7ae32bc878b8c7 upstream. There are several places opencoding this conversion, add a helper now that we have 3 compression algorithms. Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Btrfs: fix race leading to fs corruption after transaction abortFilipe Manana2019-08-061-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit cb2d3daddbfb6318d170e79aac1f7d5e4d49f0d7 upstream. When one transaction is finishing its commit, it is possible for another transaction to start and enter its initial commit phase as well. If the first ends up getting aborted, we have a small time window where the second transaction commit does not notice that the previous transaction aborted and ends up committing, writing a superblock that points to btrees that reference extent buffers (nodes and leafs) that were not persisted to disk. The consequence is that after mounting the filesystem again, we will be unable to load some btree nodes/leafs, either because the content on disk is either garbage (or just zeroes) or corresponds to the old content of a previouly COWed or deleted node/leaf, resulting in the well known error messages "parent transid verify failed on ...". The following sequence diagram illustrates how this can happen. CPU 1 CPU 2 <at transaction N> btrfs_commit_transaction() (...) --> sets transaction state to TRANS_STATE_UNBLOCKED --> sets fs_info->running_transaction to NULL (...) btrfs_start_transaction() start_transaction() wait_current_trans() --> returns immediately because fs_info->running_transaction is NULL join_transaction() --> creates transaction N + 1 --> sets fs_info->running_transaction to transaction N + 1 --> adds transaction N + 1 to the fs_info->trans_list list --> returns transaction handle pointing to the new transaction N + 1 (...) btrfs_sync_file() btrfs_start_transaction() --> returns handle to transaction N + 1 (...) btrfs_write_and_wait_transaction() --> writeback of some extent buffer fails, returns an error btrfs_handle_fs_error() --> sets BTRFS_FS_STATE_ERROR in fs_info->fs_state --> jumps to label "scrub_continue" cleanup_transaction() btrfs_abort_transaction(N) --> sets BTRFS_FS_STATE_TRANS_ABORTED flag in fs_info->fs_state --> sets aborted field in the transaction and transaction handle structures, for transaction N only --> removes transaction from the list fs_info->trans_list btrfs_commit_transaction(N + 1) --> transaction N + 1 was not aborted, so it proceeds (...) --> sets the transaction's state to TRANS_STATE_COMMIT_START --> does not find the previous transaction (N) in the fs_info->trans_list, so it doesn't know that transaction was aborted, and the commit of transaction N + 1 proceeds (...) --> sets transaction N + 1 state to TRANS_STATE_UNBLOCKED btrfs_write_and_wait_transaction() --> succeeds writing all extent buffers created in the transaction N + 1 write_all_supers() --> succeeds --> we now have a superblock on disk that points to trees that refer to at least one extent buffer that was never persisted So fix this by updating the transaction commit path to check if the flag BTRFS_FS_STATE_TRANS_ABORTED is set on fs_info->fs_state if after setting the transaction to the TRANS_STATE_COMMIT_START we do not find any previous transaction in the fs_info->trans_list. If the flag is set, just fail the transaction commit with -EROFS, as we do in other places. The exact error code for the previous transaction abort was already logged and reported. Fixes: 49b25e0540904b ("btrfs: enhance transaction abort infrastructure") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Btrfs: fix incremental send failure after deduplicationFilipe Manana2019-08-061-62/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit b4f9a1a87a48c255bb90d8a6c3d555a1abb88130 upstream. When doing an incremental send operation we can fail if we previously did deduplication operations against a file that exists in both snapshots. In that case we will fail the send operation with -EIO and print a message to dmesg/syslog like the following: BTRFS error (device sdc): Send: inconsistent snapshot, found updated \ extent for inode 257 without updated inode item, send root is 258, \ parent root is 257 This requires that we deduplicate to the same file in both snapshots for the same amount of times on each snapshot. The issue happens because a deduplication only updates the iversion of an inode and does not update any other field of the inode, therefore if we deduplicate the file on each snapshot for the same amount of time, the inode will have the same iversion value (stored as the "sequence" field on the inode item) on both snapshots, therefore it will be seen as unchanged between in the send snapshot while there are new/updated/deleted extent items when comparing to the parent snapshot. This makes the send operation return -EIO and print an error message. Example reproducer: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt # Create our first file. The first half of the file has several 64Kb # extents while the second half as a single 512Kb extent. $ xfs_io -f -s -c "pwrite -S 0xb8 -b 64K 0 512K" /mnt/foo $ xfs_io -c "pwrite -S 0xb8 512K 512K" /mnt/foo # Create the base snapshot and the parent send stream from it. $ btrfs subvolume snapshot -r /mnt /mnt/mysnap1 $ btrfs send -f /tmp/1.snap /mnt/mysnap1 # Create our second file, that has exactly the same data as the first # file. $ xfs_io -f -c "pwrite -S 0xb8 0 1M" /mnt/bar # Create the second snapshot, used for the incremental send, before # doing the file deduplication. $ btrfs subvolume snapshot -r /mnt /mnt/mysnap2 # Now before creating the incremental send stream: # # 1) Deduplicate into a subrange of file foo in snapshot mysnap1. This # will drop several extent items and add a new one, also updating # the inode's iversion (sequence field in inode item) by 1, but not # any other field of the inode; # # 2) Deduplicate into a different subrange of file foo in snapshot # mysnap2. This will replace an extent item with a new one, also # updating the inode's iversion by 1 but not any other field of the # inode. # # After these two deduplication operations, the inode items, for file # foo, are identical in both snapshots, but we have different extent # items for this inode in both snapshots. We want to check this doesn't # cause send to fail with an error or produce an incorrect stream. $ xfs_io -r -c "dedupe /mnt/bar 0 0 512K" /mnt/mysnap1/foo $ xfs_io -r -c "dedupe /mnt/bar 512K 512K 512K" /mnt/mysnap2/foo # Create the incremental send stream. $ btrfs send -p /mnt/mysnap1 -f /tmp/2.snap /mnt/mysnap2 ERROR: send ioctl failed with -5: Input/output error This issue started happening back in 2015 when deduplication was updated to not update the inode's ctime and mtime and update only the iversion. Back then we would hit a BUG_ON() in send, but later in 2016 send was updated to return -EIO and print the error message instead of doing the BUG_ON(). A test case for fstests follows soon. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203933 Fixes: 1c919a5e13702c ("btrfs: don't update mtime/ctime on deduped inodes") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: fix minimum number of chunk errors for DUPDavid Sterba2019-08-061-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 0ee5f8ae082e1f675a2fb6db601c31ac9958a134 ] The list of profiles in btrfs_chunk_max_errors lists DUP as a profile DUP able to tolerate 1 device missing. Though this profile is special with 2 copies, it still needs the device, unlike the others. Looking at the history of changes, thre's no clear reason why DUP is there, functions were refactored and blocks of code merged to one helper. d20983b40e828 Btrfs: fix writing data into the seed filesystem - factor code to a helper de11cc12df173 Btrfs: don't pre-allocate btrfs bio - unrelated change, DUP still in the list with max errors 1 a236aed14ccb0 Btrfs: Deal with failed writes in mirrored configurations - introduced the max errors, leaves DUP and RAID1 in the same group Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: inode: Don't compress if NODATASUM or NODATACOW setQu Wenruo2019-07-311-1/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 42c16da6d684391db83788eb680accd84f6c2083 upstream. As btrfs(5) specified: Note If nodatacow or nodatasum are enabled, compression is disabled. If NODATASUM or NODATACOW set, we should not compress the extent. Normally NODATACOW is detected properly in run_delalloc_range() so compression won't happen for NODATACOW. However for NODATASUM we don't have any check, and it can cause compressed extent without csum pretty easily, just by: mkfs.btrfs -f $dev mount $dev $mnt -o nodatasum touch $mnt/foobar mount -o remount,datasum,compress $mnt xfs_io -f -c "pwrite 0 128K" $mnt/foobar And in fact, we have a bug report about corrupted compressed extent without proper data checksum so even RAID1 can't recover the corruption. (https://bugzilla.kernel.org/show_bug.cgi?id=199707) Running compression without proper checksum could cause more damage when corruption happens, as compressed data could make the whole extent unreadable, so there is no need to allow compression for NODATACSUM. The fix will refactor the inode compression check into two parts: - inode_can_compress() As the hard requirement, checked at btrfs_run_delalloc_range(), so no compression will happen for NODATASUM inode at all. - inode_need_compress() As the soft requirement, checked at btrfs_run_delalloc_range() and compress_file_range(). Reported-by: James Harvey <jamespharvey20@gmail.com> CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Btrfs: add missing inode version, ctime and mtime updates when punching holeFilipe Manana2019-07-311-0/+5
| | | | | | | | | | | | | | | | | | | | commit 179006688a7e888cbff39577189f2e034786d06a upstream. If the range for which we are punching a hole covers only part of a page, we end up updating the inode item but we skip the update of the inode's iversion, mtime and ctime. Fix that by ensuring we update those properties of the inode. A patch for fstests test case generic/059 that tests this as been sent along with this fix. Fixes: 2aaa66558172b0 ("Btrfs: add hole punching") Fixes: e8c1c76e804b18 ("Btrfs: add missing inode update when punching hole") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Btrfs: fix fsync not persisting dentry deletions due to inode evictionsFilipe Manana2019-07-311-2/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 803f0f64d17769071d7287d9e3e3b79a3e1ae937 upstream. In order to avoid searches on a log tree when unlinking an inode, we check if the inode being unlinked was logged in the current transaction, as well as the inode of its parent directory. When any of the inodes are logged, we proceed to delete directory items and inode reference items from the log, to ensure that if a subsequent fsync of only the inode being unlinked or only of the parent directory when the other is not fsync'ed as well, does not result in the entry still existing after a power failure. That check however is not reliable when one of the inodes involved (the one being unlinked or its parent directory's inode) is evicted, since the logged_trans field is transient, that is, it is not stored on disk, so it is lost when the inode is evicted and loaded into memory again (which is set to zero on load). As a consequence the checks currently being done by btrfs_del_dir_entries_in_log() and btrfs_del_inode_ref_in_log() always return true if the inode was evicted before, regardless of the inode having been logged or not before (and in the current transaction), this results in the dentry being unlinked still existing after a log replay if after the unlink operation only one of the inodes involved is fsync'ed. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/dir $ touch /mnt/dir/foo $ xfs_io -c fsync /mnt/dir/foo # Keep an open file descriptor on our directory while we evict inodes. # We just want to evict the file's inode, the directory's inode must not # be evicted. $ ( cd /mnt/dir; while true; do :; done ) & $ pid=$! # Wait a bit to give time to background process to chdir to our test # directory. $ sleep 0.5 # Trigger eviction of the file's inode. $ echo 2 > /proc/sys/vm/drop_caches # Unlink our file and fsync the parent directory. After a power failure # we don't expect to see the file anymore, since we fsync'ed the parent # directory. $ rm -f $SCRATCH_MNT/dir/foo $ xfs_io -c fsync /mnt/dir <power failure> $ mount /dev/sdb /mnt $ ls /mnt/dir foo $ --> file still there, unlink not persisted despite explicit fsync on dir Fix this by checking if the inode has the full_sync bit set in its runtime flags as well, since that bit is set everytime an inode is loaded from disk, or for other less common cases such as after a shrinking truncate or failure to allocate extent maps for holes, and gets cleared after the first fsync. Also consider the inode as possibly logged only if it was last modified in the current transaction (besides having the full_fsync flag set). Fixes: 3a5f1d458ad161 ("Btrfs: Optimize btree walking while logging inodes") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Btrfs: fix data loss after inode eviction, renaming it, and fsync itFilipe Manana2019-07-311-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit d1d832a0b51dd9570429bb4b81b2a6c1759e681a upstream. When we log an inode, regardless of logging it completely or only that it exists, we always update it as logged (logged_trans and last_log_commit fields of the inode are updated). This is generally fine and avoids future attempts to log it from having to do repeated work that brings no value. However, if we write data to a file, then evict its inode after all the dealloc was flushed (and ordered extents completed), rename the file and fsync it, we end up not logging the new extents, since the rename may result in logging that the inode exists in case the parent directory was logged before. The following reproducer shows and explains how this can happen: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/dir $ touch /mnt/dir/foo $ touch /mnt/dir/bar # Do a direct IO write instead of a buffered write because with a # buffered write we would need to make sure dealloc gets flushed and # complete before we do the inode eviction later, and we can not do that # from user space with call to things such as sync(2) since that results # in a transaction commit as well. $ xfs_io -d -c "pwrite -S 0xd3 0 4K" /mnt/dir/bar # Keep the directory dir in use while we evict inodes. We want our file # bar's inode to be evicted but we don't want our directory's inode to # be evicted (if it were evicted too, we would not be able to reproduce # the issue since the first fsync below, of file foo, would result in a # transaction commit. $ ( cd /mnt/dir; while true; do :; done ) & $ pid=$! # Wait a bit to give time for the background process to chdir. $ sleep 0.1 # Evict all inodes, except the inode for the directory dir because it is # currently in use by our background process. $ echo 2 > /proc/sys/vm/drop_caches # fsync file foo, which ends up persisting information about the parent # directory because it is a new inode. $ xfs_io -c fsync /mnt/dir/foo # Rename bar, this results in logging that this inode exists (inode item, # names, xattrs) because the parent directory is in the log. $ mv /mnt/dir/bar /mnt/dir/baz # Now fsync baz, which ends up doing absolutely nothing because of the # rename operation which logged that the inode exists only. $ xfs_io -c fsync /mnt/dir/baz <power failure> $ mount /dev/sdb /mnt $ od -t x1 -A d /mnt/dir/baz 0000000 --> Empty file, data we wrote is missing. Fix this by not updating last_sub_trans of an inode when we are logging only that it exists and the inode was not yet logged since it was loaded from disk (full_sync bit set), this is enough to make btrfs_inode_in_log() return false for this scenario and make us log the inode. The logged_trans of the inode is still always setsince that alone is used to track if names need to be deleted as part of unlink operations. Fixes: 257c62e1bce03e ("Btrfs: avoid tree log commit when there are no changes") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* stable/btrfs: fix backport bug in d819d97ea025 ("btrfs: honor ↵Stanislaw Gruszka2019-07-101-2/+0
| | | | | | | | | | | | | | | | path->skip_locking in backref code") Upstream commit 38e3eebff643 ("btrfs: honor path->skip_locking in backref code") was incorrectly backported to 4.14.y . It misses removal of two lines from original commit, what cause deadlock. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203993 Reported-by: Olivier Mazouffre <olivier.mazouffre@ims-bordeaux.fr> Fixes: d819d97ea025 ("btrfs: honor path->skip_locking in backref code") Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: Ensure replaced device doesn't have pending chunk allocationNikolay Borisov2019-07-103-10/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit debd1c065d2037919a7da67baf55cc683fee09f0 upstream. Recent FITRIM work, namely bbbf7243d62d ("btrfs: combine device update operations during transaction commit") combined the way certain operations are recoded in a transaction. As a result an ASSERT was added in dev_replace_finish to ensure the new code works correctly. Unfortunately I got reports that it's possible to trigger the assert, meaning that during a device replace it's possible to have an unfinished chunk allocation on the source device. This is supposed to be prevented by the fact that a transaction is committed before finishing the replace oepration and alter acquiring the chunk mutex. This is not sufficient since by the time the transaction is committed and the chunk mutex acquired it's possible to allocate a chunk depending on the workload being executed on the replaced device. This bug has been present ever since device replace was introduced but there was never code which checks for it. The correct way to fix is to ensure that there is no pending device modification operation when the chunk mutex is acquire and if there is repeat transaction commit. Unfortunately it's not possible to just exclude the source device from btrfs_fs_devices::dev_alloc_list since this causes ENOSPC to be hit in transaction commit. Fixing that in another way would need to add special cases to handle the last writes and forbid new ones. The looped transaction fix is more obvious, and can be easily backported. The runtime of dev-replace is long so there's no noticeable delay caused by that. Reported-by: David Sterba <dsterba@suse.com> Fixes: 391cd9df81ac ("Btrfs: fix unprotected alloc list insertion during the finishing procedure of replace") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: start readahead also in seed devicesNaohiro Aota2019-06-251-0/+5
| | | | | | | | | | | | | | | | | | | | commit c4e0540d0ad49c8ceab06cceed1de27c4fe29f6e upstream. Currently, btrfs does not consult seed devices to start readahead. As a result, if readahead zone is added to the seed devices, btrfs_reada_wait() indefinitely wait for the reada_ctl to finish. You can reproduce the hung by modifying btrfs/163 to have larger initial file size (e.g. xfs_io pwrite 4M instead of current 256K). Fixes: 7414a03fbf9e ("btrfs: initial readahead code and prototypes") Cc: stable@vger.kernel.org # 3.2+: ce7791ffee1e: Btrfs: fix race between readahead and device replace/removal Cc: stable@vger.kernel.org # 3.2+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Btrfs: incremental send, fix file corruption when no-holes feature is enabledFilipe Manana2019-06-091-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 6b1f72e5b82a5c2a4da4d1ebb8cc01913ddbea21 upstream. When using the no-holes feature, if we have a file with prealloc extents with a start offset beyond the file's eof, doing an incremental send can cause corruption of the file due to incorrect hole detection. Such case requires that the prealloc extent(s) exist in both the parent and send snapshots, and that a hole is punched into the file that covers all its extents that do not cross the eof boundary. Example reproducer: $ mkfs.btrfs -f -O no-holes /dev/sdb $ mount /dev/sdb /mnt/sdb $ xfs_io -f -c "pwrite -S 0xab 0 500K" /mnt/sdb/foobar $ xfs_io -c "falloc -k 1200K 800K" /mnt/sdb/foobar $ btrfs subvolume snapshot -r /mnt/sdb /mnt/sdb/base $ btrfs send -f /tmp/base.snap /mnt/sdb/base $ xfs_io -c "fpunch 0 500K" /mnt/sdb/foobar $ btrfs subvolume snapshot -r /mnt/sdb /mnt/sdb/incr $ btrfs send -p /mnt/sdb/base -f /tmp/incr.snap /mnt/sdb/incr $ md5sum /mnt/sdb/incr/foobar 816df6f64deba63b029ca19d880ee10a /mnt/sdb/incr/foobar $ mkfs.btrfs -f /dev/sdc $ mount /dev/sdc /mnt/sdc $ btrfs receive -f /tmp/base.snap /mnt/sdc $ btrfs receive -f /tmp/incr.snap /mnt/sdc $ md5sum /mnt/sdc/incr/foobar cf2ef71f4a9e90c2f6013ba3b2257ed2 /mnt/sdc/incr/foobar --> Different checksum, because the prealloc extent beyond the file's eof confused the hole detection code and it assumed a hole starting at offset 0 and ending at the offset of the prealloc extent (1200Kb) instead of ending at the offset 500Kb (the file's size). Fix this by ensuring we never cross the file's size when issuing the write operations for a hole. Fixes: 16e7549f045d33 ("Btrfs: incompatible format change to remove hole extents") CC: stable@vger.kernel.org # 3.14+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Btrfs: fix fsync not persisting changed attributes of a directoryFilipe Manana2019-06-091-12/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 60d9f50308e5df19bc18c2fefab0eba4a843900a upstream. While logging an inode we follow its ancestors and for each one we mark it as logged in the current transaction, even if we have not logged it. As a consequence if we change an attribute of an ancestor, such as the UID or GID for example, and then explicitly fsync it, we end up not logging the inode at all despite returning success to user space, which results in the attribute being lost if a power failure happens after the fsync. Sample reproducer: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/dir $ chown 6007:6007 /mnt/dir $ sync $ chown 9003:9003 /mnt/dir $ touch /mnt/dir/file $ xfs_io -c fsync /mnt/dir/file # fsync our directory after fsync'ing the new file, should persist the # new values for the uid and gid. $ xfs_io -c fsync /mnt/dir <power failure> $ mount /dev/sdb /mnt $ stat -c %u:%g /mnt/dir 6007:6007 --> should be 9003:9003, the uid and gid were not persisted, despite the explicit fsync on the directory prior to the power failure Fix this by not updating the logged_trans field of ancestor inodes when logging an inode, since we have not logged them. Let only future calls to btrfs_log_inode() to mark inodes as logged. This could be triggered by my recent fsync fuzz tester for fstests, for which an fstests patch exists titled "fstests: generic, fsync fuzz tester with fsstress". Fixes: 12fcfd22fe5b ("Btrfs: tree logging unlink/rename fixes") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Btrfs: fix race updating log root item during fsyncFilipe Manana2019-06-091-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 06989c799f04810f6876900d4760c0edda369cf7 upstream. When syncing the log, the final phase of a fsync operation, we need to either create a log root's item or update the existing item in the log tree of log roots, and that depends on the current value of the log root's log_transid - if it's 1 we need to create the log root item, otherwise it must exist already and we update it. Since there is no synchronization between updating the log_transid and checking it for deciding whether the log root's item needs to be created or updated, we end up with a tiny race window that results in attempts to update the item to fail because the item was not yet created: CPU 1 CPU 2 btrfs_sync_log() lock root->log_mutex set log root's log_transid to 1 unlock root->log_mutex btrfs_sync_log() lock root->log_mutex sets log root's log_transid to 2 unlock root->log_mutex update_log_root() sees log root's log_transid with a value of 2 calls btrfs_update_root(), which fails with -EUCLEAN and causes transaction abort Until recently the race lead to a BUG_ON at btrfs_update_root(), but after the recent commit 7ac1e464c4d47 ("btrfs: Don't panic when we can't find a root key") we just abort the current transaction. A sample trace of the BUG_ON() on a SLE12 kernel: ------------[ cut here ]------------ kernel BUG at ../fs/btrfs/root-tree.c:157! Oops: Exception in kernel mode, sig: 5 [#1] SMP NR_CPUS=2048 NUMA pSeries (...) Supported: Yes, External CPU: 78 PID: 76303 Comm: rtas_errd Tainted: G X 4.4.156-94.57-default #1 task: c00000ffa906d010 ti: c00000ff42b08000 task.ti: c00000ff42b08000 NIP: d000000036ae5cdc LR: d000000036ae5cd8 CTR: 0000000000000000 REGS: c00000ff42b0b860 TRAP: 0700 Tainted: G X (4.4.156-94.57-default) MSR: 8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE> CR: 22444484 XER: 20000000 CFAR: d000000036aba66c SOFTE: 1 GPR00: d000000036ae5cd8 c00000ff42b0bae0 d000000036bda220 0000000000000054 GPR04: 0000000000000001 0000000000000000 c00007ffff8d37c8 0000000000000000 GPR08: c000000000e19c00 0000000000000000 0000000000000000 3736343438312079 GPR12: 3930373337303434 c000000007a3a800 00000000007fffff 0000000000000023 GPR16: c00000ffa9d26028 c00000ffa9d261f8 0000000000000010 c00000ffa9d2ab28 GPR20: c00000ff42b0bc48 0000000000000001 c00000ff9f0d9888 0000000000000001 GPR24: c00000ffa9d26000 c00000ffa9d261e8 c00000ffa9d2a800 c00000ff9f0d9888 GPR28: c00000ffa9d26028 c00000ffa9d2aa98 0000000000000001 c00000ffa98f5b20 NIP [d000000036ae5cdc] btrfs_update_root+0x25c/0x4e0 [btrfs] LR [d000000036ae5cd8] btrfs_update_root+0x258/0x4e0 [btrfs] Call Trace: [c00000ff42b0bae0] [d000000036ae5cd8] btrfs_update_root+0x258/0x4e0 [btrfs] (unreliable) [c00000ff42b0bba0] [d000000036b53610] btrfs_sync_log+0x2d0/0xc60 [btrfs] [c00000ff42b0bce0] [d000000036b1785c] btrfs_sync_file+0x44c/0x4e0 [btrfs] [c00000ff42b0bd80] [c00000000032e300] vfs_fsync_range+0x70/0x120 [c00000ff42b0bdd0] [c00000000032e44c] do_fsync+0x5c/0xb0 [c00000ff42b0be10] [c00000000032e8dc] SyS_fdatasync+0x2c/0x40 [c00000ff42b0be30] [c000000000009488] system_call+0x3c/0x100 Instruction dump: 7f43d378 4bffebb9 60000000 88d90008 3d220000 e8b90000 3b390009 e87a01f0 e8898e08 e8f90000 4bfd48e5 60000000 <0fe00000> e95b0060 39200004 394a0ea0 ---[ end trace 8f2dc8f919cabab8 ]--- So fix this by doing the check of log_transid and updating or creating the log root's item while holding the root's log_mutex. Fixes: 7237f1833601d ("Btrfs: fix tree logs parallel sync") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Btrfs: fix wrong ctime and mtime of a directory after log replayFilipe Manana2019-06-091-2/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 5338e43abbab13791144d37fd8846847062351c6 upstream. When replaying a log that contains a new file or directory name that needs to be added to its parent directory, we end up updating the mtime and the ctime of the parent directory to the current time after we have set their values to the correct ones (set at fsync time), efectivelly losing them. Sample reproducer: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/dir $ touch /mnt/dir/file # fsync of the directory is optional, not needed $ xfs_io -c fsync /mnt/dir $ xfs_io -c fsync /mnt/dir/file $ stat -c %Y /mnt/dir 1557856079 <power failure> $ sleep 3 $ mount /dev/sdb /mnt $ stat -c %Y /mnt/dir 1557856082 --> should have been 1557856079, the mtime is updated to the current time when replaying the log Fix this by not updating the mtime and ctime to the current time at btrfs_add_link() when we are replaying a log tree. This could be triggered by my recent fsync fuzz tester for fstests, for which an fstests patch exists titled "fstests: generic, fsync fuzz tester with fsstress". Fixes: e02119d5a7b43 ("Btrfs: Add a write ahead tree log to optimize synchronous operations") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: Don't panic when we can't find a root keyQu Wenruo2019-05-311-5/+8
| | | | | | | | | | | | | | | | | | [ Upstream commit 7ac1e464c4d473b517bb784f30d40da1f842482e ] When we failed to find a root key in btrfs_update_root(), we just panic. That's definitely not cool, fix it by outputting an unique error message, aborting current transaction and return -EUCLEAN. This should not normally happen as the root has been used by the callers in some way. Reviewed-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: fix panic during relocation after ENOSPC before writeback happensJosef Bacik2019-05-311-11/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit ff612ba7849964b1898fd3ccd1f56941129c6aab ] We've been seeing the following sporadically throughout our fleet panic: kernel BUG at fs/btrfs/relocation.c:4584! netversion: 5.0-0 Backtrace: #0 [ffffc90003adb880] machine_kexec at ffffffff81041da8 #1 [ffffc90003adb8c8] __crash_kexec at ffffffff8110396c #2 [ffffc90003adb988] crash_kexec at ffffffff811048ad #3 [ffffc90003adb9a0] oops_end at ffffffff8101c19a #4 [ffffc90003adb9c0] do_trap at ffffffff81019114 #5 [ffffc90003adba00] do_error_trap at ffffffff810195d0 #6 [ffffc90003adbab0] invalid_op at ffffffff81a00a9b [exception RIP: btrfs_reloc_cow_block+692] RIP: ffffffff8143b614 RSP: ffffc90003adbb68 RFLAGS: 00010246 RAX: fffffffffffffff7 RBX: ffff8806b9c32000 RCX: ffff8806aad00690 RDX: ffff880850b295e0 RSI: ffff8806b9c32000 RDI: ffff88084f205bd0 RBP: ffff880849415000 R8: ffffc90003adbbe0 R9: ffff88085ac90000 R10: ffff8805f7369140 R11: 0000000000000000 R12: ffff880850b295e0 R13: ffff88084f205bd0 R14: 0000000000000000 R15: 0000000000000000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #7 [ffffc90003adbbb0] __btrfs_cow_block at ffffffff813bf1cd #8 [ffffc90003adbc28] btrfs_cow_block at ffffffff813bf4b3 #9 [ffffc90003adbc78] btrfs_search_slot at ffffffff813c2e6c The way relocation moves data extents is by creating a reloc inode and preallocating extents in this inode and then copying the data into these preallocated extents. Once we've done this for all of our extents, we'll write out these dirty pages, which marks the extent written, and goes into btrfs_reloc_cow_block(). From here we get our current reloc_control, which _should_ match the reloc_control for the current block group we're relocating. However if we get an ENOSPC in this path at some point we'll bail out, never initiating writeback on this inode. Not a huge deal, unless we happen to be doing relocation on a different block group, and this block group is now rc->stage == UPDATE_DATA_PTRS. This trips the BUG_ON() in btrfs_reloc_cow_block(), because we expect to be done modifying the data inode. We are in fact done modifying the metadata for the data inode we're currently using, but not the one from the failed block group, and thus we BUG_ON(). (This happens when writeback finishes for extents from the previous group, when we are at btrfs_finish_ordered_io() which updates the data reloc tree (inode item, drops/adds extent items, etc).) Fix this by writing out the reloc data inode always, and then breaking out of the loop after that point to keep from tripping this BUG_ON() later. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> [ add note from Filipe ] Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* Btrfs: fix data bytes_may_use underflow with fallocate due to failed quota ↵Robbie Ko2019-05-311-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | reserve [ Upstream commit 39ad317315887c2cb9a4347a93a8859326ddf136 ] When doing fallocate, we first add the range to the reserve_list and then reserve the quota. If quota reservation fails, we'll release all reserved parts of reserve_list. However, cur_offset is not updated to indicate that this range is already been inserted into the list. Therefore, the same range is freed twice. Once at list_for_each_entry loop, and once at the end of the function. This will result in WARN_ON on bytes_may_use when we free the remaining space. At the end, under the 'out' label we have a call to: btrfs_free_reserved_data_space(inode, data_reserved, alloc_start, alloc_end - cur_offset); The start offset, third argument, should be cur_offset. Everything from alloc_start to cur_offset was freed by the list_for_each_entry_safe_loop. Fixes: 18513091af94 ("btrfs: update btrfs_space_info's bytes_may_use timely") Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Robbie Ko <robbieko@synology.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* Revert "btrfs: Honour FITRIM range constraints during free space trim"David Sterba2019-05-311-19/+6
| | | | | | | | | | | | | | | | | | | | | | This reverts commit b327ff8a9b5767ce39db650d468fb124b48974a5. There is currently no corresponding patch in master due to additional changes that would be significantly different from plain revert in the respective stable branch. The range argument was not handled correctly and could cause trim to overlap allocated areas or reach beyond the end of the device. The address space that fitrim normally operates on is in logical coordinates, while the discards are done on the physical device extents. This distinction cannot be made with the current ioctl interface and caused the confusion. The bug depends on the layout of block groups and does not always happen. The whole-fs trim (run by default by the fstrim tool) is not affected. Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>