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* btrfs: get rid of unique workqueue helper functionsOmar Sandoval2019-11-1812-145/+50
| | | | | | | | | | | | | | | | | | | | | | | | | Commit 9e0af2376434 ("Btrfs: fix task hang under heavy compressed write") worked around the issue that a recycled work item could get a false dependency on the original work item due to how the workqueue code guarantees non-reentrancy. It did so by giving different work functions to different types of work. However, the fixes in the previous few patches are more complete, as they prevent a work item from being recycled at all (except for a tiny window that the kernel workqueue code handles for us). This obsoletes the previous fix, so we don't need the unique helpers for correctness. The only other reason to keep them would be so they show up in stack traces, but they always seem to be optimized to a tail call, so they don't show up anyways. So, let's just get rid of the extra indirection. While we're here, rename normal_work_helper() to the more informative btrfs_work_helper(). Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: don't prematurely free work in scrub_missing_raid56_worker()Omar Sandoval2019-11-181-2/+1
| | | | | | | | | | | | | 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>
* btrfs: don't prematurely free work in reada_start_machine_worker()Omar Sandoval2019-11-181-6/+4
| | | | | | | | | | | | | | | | | | | | | | 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>
* btrfs: don't prematurely free work in end_workqueue_fn()Omar Sandoval2019-11-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* btrfs: don't prematurely free work in run_ordered_work()Omar Sandoval2019-11-181-12/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* btrfs: get rid of unnecessary memset() of work itemOmar Sandoval2019-11-181-2/+0
| | | | | | | | | | | | Commit fc97fab0ea59 ("btrfs: Replace fs_info->qgroup_rescan_worker workqueue with btrfs_workqueue.") converted qgroup_rescan_work to be initialized with btrfs_init_work(), but it left behind an unnecessary memset(). Get rid of the memset(). 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>
* btrfs: move the failrec tree stuff into extent-io-tree.hJosef Bacik2019-11-183-15/+22
| | | | | | | | | | | | This needs to be cleaned up in the future, but for now it belongs to the extent-io-tree stuff since it uses the internal tree search code. Needed to export get_state_failrec and set_state_failrec as well since we're not going to move the actual IO part of the failrec stuff out at this point. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: export find_delalloc_rangeJosef Bacik2019-11-182-5/+8
| | | | | | | | | This utilizes internal stuff to the extent_io_tree, so we need to export it before we move it. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: move extent_io_tree defs to their own headerJosef Bacik2019-11-184-216/+230
| | | | | | | | | extent_io.c/h are huge, encompassing a bunch of different things. The extent_io_tree code can live on its own, so separate this out. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: separate out the extent io init functionJosef Bacik2019-11-183-8/+21
| | | | | | | | | We are moving extent_io_tree into it's on file, so separate out the extent_state init stuff from extent_io_tree_init(). Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: separate out the extent leak codeJosef Bacik2019-11-181-13/+18
| | | | | | | | | We check both extent buffer and extent state leaks in the same function, separate these two functions out so we can move them around. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: ctree: Remove stray comment of setting up path lockQu Wenruo2019-11-181-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following comment shows up in btrfs_search_slot() with out much sense: /* * setup the path here so we can release it under lock * contention with the cow code */ if (cow) { /* code touching path->lock[] is far away from here */ } This comment hasn't been cleaned up after the relevant code has been removed. The original code is introduced in commit 65b51a009e29 ("btrfs_search_slot: reduce lock contention by cowing in two stages"): + + /* + * setup the path here so we can release it under lock + * contention with the cow code + */ + p->nodes[level] = b; + if (!p->skip_locking) + p->locks[level] = 1; + But in current code, we have different timing for modifying path lock, so just remove the comment. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: ctree: Reduce one indent level for btrfs_search_old_slot()Qu Wenruo2019-11-181-34/+34
| | | | | | | | | | | | Similar to btrfs_search_slot() done in previous patch, make a shortcut for the level 0 case and allow to reduce indentation for the remaining case. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: ctree: Reduce one indent level for btrfs_search_slot()Qu Wenruo2019-11-181-67/+64
| | | | | | | | | | | | | | | | | | | | | | | | | | | | In btrfs_search_slot(), we something like: if (level != 0) { /* Do search inside tree nodes*/ } else { /* Do search inside tree leaves */ goto done; } This caused extra indent for tree node search code. Change it to something like: if (level == 0) { /* Do search inside tree leaves */ goto done' } /* Do search inside tree nodes */ So we have more space to maneuver our code, this is especially useful as the tree nodes search code is more complex than the leaves search code. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: tree-checker: Add check for INODE_REFQu Wenruo2019-11-181-0/+53
| | | | | | | | | | | | | For INODE_REF we will check: - Objectid (ino) against previous key To detect missing INODE_ITEM. - No overflow/padding in the data payload Much like DIR_ITEM, but with less members to check. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: tree-checker: Try to detect missing INODE_ITEMQu Wenruo2019-11-181-2/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For the following items, key->objectid is inode number: - DIR_ITEM - DIR_INDEX - XATTR_ITEM - EXTENT_DATA - INODE_REF So in the subvolume tree, such items must have its previous item share the same objectid, e.g.: (257 INODE_ITEM 0) (257 DIR_INDEX xxx) (257 DIR_ITEM xxx) (258 INODE_ITEM 0) (258 INODE_REF 0) (258 XATTR_ITEM 0) (258 EXTENT_DATA 0) But if we have the following sequence, then there is definitely something wrong, normally some INODE_ITEM is missing, like: (257 INODE_ITEM 0) (257 DIR_INDEX xxx) (257 DIR_ITEM xxx) (258 XATTR_ITEM 0) <<< objecitd suddenly changed to 258 (258 EXTENT_DATA 0) So just by checking the previous key for above inode based key types, we can detect a missing inode item. For INODE_REF key type, the check will be added along with INODE_REF checker. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* Btrfs: make btrfs_wait_extents() staticFilipe Manana2019-11-182-3/+1
| | | | | | | | It's not used ouside of transaction.c Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: Add assert to catch nested transaction commitNikolay Borisov2019-11-181-0/+2
| | | | | | | | | | | | | | | | | | A recent patch to btrfs showed that there was at least 1 case where a nested transaction was committed. Nested transaction in this case means a code which has a transaction handle calls some function which in turn obtains a copy of the same transaction handle. In such cases the correct thing to do is for the lower callee to call btrfs_end_transaction which contains appropriate checks so as to not commit the transaction which will result in stale trans handler for the caller. To catch such cases add an assert in btrfs_commit_transaction ensuring btrfs_trans_handle::use_count is always 1. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: simplify inode locking for RWF_NOWAITGoldwyn Rodrigues2019-11-181-2/+3
| | | | | | | | | | | | | | This is similar to 942491c9e6d6 ("xfs: fix AIM7 regression"). Apparently our current rwsem code doesn't like doing the trylock, then lock for real scheme. This causes extra contention on the lock and can be measured eg. by AIM7 benchmark. So change our read/write methods to just do the trylock for the RWF_NOWAIT case. Fixes: edf064e7c6fe ("btrfs: nowait aio support") Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
* Merge tag 'for-linus-20191115' of git://git.kernel.dk/linux-blockLinus Torvalds2019-11-151-8/+24
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block fixes from Jens Axboe: "A few fixes that should make it into this release. This contains: - io_uring: - The timeout command assumes sequence == 0 means that we want one completion, but this kind of overloading is unfortunate as it prevents users from doing a pure time based wait. Since this operation was introduced in this cycle, let's correct it now, while we can. (me) - One-liner to fix an issue with dependent links and fixed buffer reads. The actual IO completed fine, but the link got severed since we stored the wrong expected value. (me) - Add TIMEOUT to list of opcodes that don't need a file. (Pavel) - rsxx missing workqueue destry calls. Old bug. (Chuhong) - Fix blk-iocost active list check (Jiufei) - Fix impossible-to-hit overflow merge condition, that still hit some folks very rarely (Junichi) - Fix bfq hang issue from 5.3. This didn't get marked for stable, but will go into stable post this merge (Paolo)" * tag 'for-linus-20191115' of git://git.kernel.dk/linux-block: rsxx: add missed destroy_workqueue calls in remove iocost: check active_list of all the ancestors in iocg_activate() block, bfq: deschedule empty bfq_queues not referred by any process io_uring: ensure registered buffer import returns the IO length io_uring: Fix getting file for timeout block: check bi_size overflow before merge io_uring: make timeout sequence == 0 mean no sequence
| * io_uring: ensure registered buffer import returns the IO lengthJens Axboe2019-11-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A test case was reported where two linked reads with registered buffers failed the second link always. This is because we set the expected value of a request in req->result, and if we don't get this result, then we fail the dependent links. For some reason the registered buffer import returned -ERROR/0, while the normal import returns -ERROR/length. This broke linked commands with registered buffers. Fix this by making io_import_fixed() correctly return the mapped length. Cc: stable@vger.kernel.org # v5.3 Reported-by: 李通洲 <carter.li@eoitek.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * io_uring: Fix getting file for timeoutPavel Begunkov2019-11-131-0/+1
| | | | | | | | | | | | | | | | | | For timeout requests io_uring tries to grab a file with specified fd, which is usually stdin/fd=0. Update io_op_needs_file() Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * io_uring: make timeout sequence == 0 mean no sequenceJens Axboe2019-11-121-7/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | Currently we make sequence == 0 be the same as sequence == 1, but that's not super useful if the intent is really to have a timeout that's just a pure timeout. If the user passes in sqe->off == 0, then don't apply any sequence logic to the request, let it purely be driven by the timeout specified. Reported-by: 李通洲 <carter.li@eoitek.com> Reviewed-by: 李通洲 <carter.li@eoitek.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | Merge tag 'ceph-for-5.4-rc8' of git://github.com/ceph/ceph-clientLinus Torvalds2019-11-151-7/+22
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull ceph fixes from Ilya Dryomov: "Two fixes for the buffered reads and O_DIRECT writes serialization patch that went into -rc1 and a fixup for a bogus warning on older gcc versions" * tag 'ceph-for-5.4-rc8' of git://github.com/ceph/ceph-client: rbd: silence bogus uninitialized warning in rbd_object_map_update_finish() ceph: increment/decrement dio counter on async requests ceph: take the inode lock before acquiring cap refs
| * | ceph: increment/decrement dio counter on async requestsJeff Layton2019-11-141-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ceph can in some cases issue an async DIO request, in which case we can end up calling ceph_end_io_direct before the I/O is actually complete. That may allow buffered operations to proceed while DIO requests are still in flight. Fix this by incrementing the i_dio_count when issuing an async DIO request, and decrement it when tearing down the aio_req. Fixes: 321fe13c9398 ("ceph: add buffered/direct exclusionary locking for reads and writes") Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
| * | ceph: take the inode lock before acquiring cap refsJeff Layton2019-11-141-7/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Most of the time, we (or the vfs layer) takes the inode_lock and then acquires caps, but ceph_read_iter does the opposite, and that can lead to a deadlock. When there are multiple clients treading over the same data, we can end up in a situation where a reader takes caps and then tries to acquire the inode_lock. Another task holds the inode_lock and issues a request to the MDS which needs to revoke the caps, but that can't happen until the inode_lock is unwedged. Fix this by having ceph_read_iter take the inode_lock earlier, before attempting to acquire caps. Fixes: 321fe13c9398 ("ceph: add buffered/direct exclusionary locking for reads and writes") Link: https://tracker.ceph.com/issues/36348 Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
* | | afs: Fix race in commit bulk status fetchDavid Howells2019-11-151-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a lookup is done, the afs filesystem will perform a bulk status-fetch operation on the requested vnode (file) plus the next 49 other vnodes from the directory list (in AFS, directory contents are downloaded as blobs and parsed locally). When the results are received, it will speculatively populate the inode cache from the extra data. However, if the lookup races with another lookup on the same directory, but for a different file - one that's in the 49 extra fetches, then if the bulk status-fetch operation finishes first, it will try and update the inode from the other lookup. If this other inode is still in the throes of being created, however, this will cause an assertion failure in afs_apply_status(): BUG_ON(test_bit(AFS_VNODE_UNSET, &vnode->flags)); on or about fs/afs/inode.c:175 because it expects data to be there already that it can compare to. Fix this by skipping the update if the inode is being created as the creator will presumably set up the inode with the same information. Fixes: 39db9815da48 ("afs: Fix application of the results of a inline bulk status fetch") Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds2019-11-155-58/+87
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull misc vfs fixes from Al Viro: "Assorted fixes all over the place; some of that is -stable fodder, some regressions from the last window" * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: ecryptfs_lookup_interpose(): lower_dentry->d_parent is not stable either ecryptfs_lookup_interpose(): lower_dentry->d_inode is not stable ecryptfs: fix unlink and rmdir in face of underlying fs modifications audit_get_nd(): don't unlock parent too early exportfs_decode_fh(): negative pinned may become positive without the parent locked cgroup: don't put ERR_PTR() into fc->root autofs: fix a leak in autofs_expire_indirect() aio: Fix io_pgetevents() struct __compat_aio_sigset layout fs/namespace.c: fix use-after-free of mount in mnt_warn_timestamp_expiry()
| * | | ecryptfs_lookup_interpose(): lower_dentry->d_parent is not stable eitherAl Viro2019-11-101-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We need to get the underlying dentry of parent; sure, absent the races it is the parent of underlying dentry, but there's nothing to prevent losing a timeslice to preemtion in the middle of evaluation of lower_dentry->d_parent->d_inode, having another process move lower_dentry around and have its (ex)parent not pinned anymore and freed on memory pressure. Then we regain CPU and try to fetch ->d_inode from memory that is freed by that point. dentry->d_parent *is* stable here - it's an argument of ->lookup() and we are guaranteed that it won't be moved anywhere until we feed it to d_add/d_splice_alias. So we safely go that way to get to its underlying dentry. Cc: stable@vger.kernel.org # since 2009 or so Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | ecryptfs_lookup_interpose(): lower_dentry->d_inode is not stableAl Viro2019-11-101-2/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | lower_dentry can't go from positive to negative (we have it pinned), but it *can* go from negative to positive. So fetching ->d_inode into a local variable, doing a blocking allocation, checking that now ->d_inode is non-NULL and feeding the value we'd fetched earlier to a function that won't accept NULL is not a good idea. Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | ecryptfs: fix unlink and rmdir in face of underlying fs modificationsAl Viro2019-11-101-25/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A problem similar to the one caught in commit 74dd7c97ea2a ("ecryptfs_rename(): verify that lower dentries are still OK after lock_rename()") exists for unlink/rmdir as well. Instead of playing with dget_parent() of underlying dentry of victim and hoping it's the same as underlying dentry of our directory, do the following: * find the underlying dentry of victim * find the underlying directory of victim's parent (stable since the victim is ecryptfs dentry and inode of its parent is held exclusive by the caller). * lock the inode of dentry underlying the victim's parent * check that underlying dentry of victim is still hashed and has the right parent - it can be moved, but it can't be moved to/from the directory we are holding exclusive. So while ->d_parent itself might not be stable, the result of comparison is. If the check passes, everything is fine - underlying directory is locked, underlying victim is still a child of that directory and we can go ahead and feed them to vfs_unlink(). As in the current mainline we need to pin the underlying dentry of victim, so that it wouldn't go negative under us, but that's the only temporary reference that needs to be grabbed there. Underlying dentry of parent won't go away (it's pinned by the parent, which is held by caller), so there's no need to grab it. The same problem (with the same solution) exists for rmdir. Moreover, rename gets simpler and more robust with the same "don't bother with dget_parent()" approach. Fixes: 74dd7c97ea2 "ecryptfs_rename(): verify that lower dentries are still OK after lock_rename()" Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | exportfs_decode_fh(): negative pinned may become positive without the parent ↵Al Viro2019-11-101-12/+19
| | | | | | | | | | | | | | | | | | | | | | | | locked Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | autofs: fix a leak in autofs_expire_indirect()Al Viro2019-10-251-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | if the second call of should_expire() in there ends up grabbing and returning a new reference to dentry, we need to drop it before continuing. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | aio: Fix io_pgetevents() struct __compat_aio_sigset layoutGuillem Jover2019-10-211-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This type is used to pass the sigset_t from userland to the kernel, but it was using the kernel native pointer type for the member representing the compat userland pointer to the userland sigset_t. This messes up the layout, and makes the kernel eat up both the userland pointer and the size members into the kernel pointer, and then reads garbage into the kernel sigsetsize. Which makes the sigset_t size consistency check fail, and consequently the syscall always returns -EINVAL. This breaks both libaio and strace on 32-bit userland running on 64-bit kernels. And there are apparently no users in the wild of the current broken layout (at least according to codesearch.debian.org and a brief check over github.com search). So it looks safe to fix this directly in the kernel, instead of either letting userland deal with this permanently with the additional overhead or trying to make the syscall infer what layout userland used, even though this is also being worked around in libaio to temporarily cope with kernels that have not yet been fixed. We use a proper compat_uptr_t instead of a compat_sigset_t pointer. Fixes: 7a074e96dee6 ("aio: implement io_pgetevents") Signed-off-by: Guillem Jover <guillem@hadrons.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | fs/namespace.c: fix use-after-free of mount in mnt_warn_timestamp_expiry()Eric Biggers2019-10-161-8/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After do_add_mount() returns success, the caller doesn't hold a reference to the 'struct mount' anymore. So it's invalid to access it in mnt_warn_timestamp_expiry(). Fix it by calling mnt_warn_timestamp_expiry() before do_add_mount() rather than after, and adjusting the warning message accordingly. Reported-by: syzbot+da4f525235510683d855@syzkaller.appspotmail.com Fixes: f8b92ba67c5d ("mount: Add mount warning for impending timestamp expiry") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | | Merge tag 'for-5.4-rc7-tag' of ↵Linus Torvalds2019-11-131-0/+15
|\ \ \ \ | |_|/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fix from David Sterba: "A fix for an older bug that has started to show up during testing (because of an updated test for rename exchange). It's an in-memory corruption caused by local variable leaking out of the function scope" * tag 'for-5.4-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: Btrfs: fix log context list corruption after rename exchange operation
| * | | Btrfs: fix log context list corruption after rename exchange operationFilipe Manana2019-11-111-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During rename exchange we might have successfully log the new name in the source root's log tree, in which case we leave our log context (allocated on stack) in the root's list of log contextes. However we might fail to log the new name in the destination root, in which case we fallback to a transaction commit later and never sync the log of the source root, which causes the source root log context to remain in the list of log contextes. This later causes invalid memory accesses because the context was allocated on stack and after rename exchange finishes the stack gets reused and overwritten for other purposes. The kernel's linked list corruption detector (CONFIG_DEBUG_LIST=y) can detect this and report something like the following: [ 691.489929] ------------[ cut here ]------------ [ 691.489947] list_add corruption. prev->next should be next (ffff88819c944530), but was ffff8881c23f7be4. (prev=ffff8881c23f7a38). [ 691.489967] WARNING: CPU: 2 PID: 28933 at lib/list_debug.c:28 __list_add_valid+0x95/0xe0 (...) [ 691.489998] CPU: 2 PID: 28933 Comm: fsstress Not tainted 5.4.0-rc6-btrfs-next-62 #1 [ 691.490001] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014 [ 691.490003] RIP: 0010:__list_add_valid+0x95/0xe0 (...) [ 691.490007] RSP: 0018:ffff8881f0b3faf8 EFLAGS: 00010282 [ 691.490010] RAX: 0000000000000000 RBX: ffff88819c944530 RCX: 0000000000000000 [ 691.490011] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffffa2c497e0 [ 691.490013] RBP: ffff8881f0b3fe68 R08: ffffed103eaa4115 R09: ffffed103eaa4114 [ 691.490015] R10: ffff88819c944000 R11: ffffed103eaa4115 R12: 7fffffffffffffff [ 691.490016] R13: ffff8881b4035610 R14: ffff8881e7b84728 R15: 1ffff1103e167f7b [ 691.490019] FS: 00007f4b25ea2e80(0000) GS:ffff8881f5500000(0000) knlGS:0000000000000000 [ 691.490021] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 691.490022] CR2: 00007fffbb2d4eec CR3: 00000001f2a4a004 CR4: 00000000003606e0 [ 691.490025] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 691.490027] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 691.490029] Call Trace: [ 691.490058] btrfs_log_inode_parent+0x667/0x2730 [btrfs] [ 691.490083] ? join_transaction+0x24a/0xce0 [btrfs] [ 691.490107] ? btrfs_end_log_trans+0x80/0x80 [btrfs] [ 691.490111] ? dget_parent+0xb8/0x460 [ 691.490116] ? lock_downgrade+0x6b0/0x6b0 [ 691.490121] ? rwlock_bug.part.0+0x90/0x90 [ 691.490127] ? do_raw_spin_unlock+0x142/0x220 [ 691.490151] btrfs_log_dentry_safe+0x65/0x90 [btrfs] [ 691.490172] btrfs_sync_file+0x9f1/0xc00 [btrfs] [ 691.490195] ? btrfs_file_write_iter+0x1800/0x1800 [btrfs] [ 691.490198] ? rcu_read_lock_any_held.part.11+0x20/0x20 [ 691.490204] ? __do_sys_newstat+0x88/0xd0 [ 691.490207] ? cp_new_stat+0x5d0/0x5d0 [ 691.490218] ? do_fsync+0x38/0x60 [ 691.490220] do_fsync+0x38/0x60 [ 691.490224] __x64_sys_fdatasync+0x32/0x40 [ 691.490228] do_syscall_64+0x9f/0x540 [ 691.490233] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 691.490235] RIP: 0033:0x7f4b253ad5f0 (...) [ 691.490239] RSP: 002b:00007fffbb2d6078 EFLAGS: 00000246 ORIG_RAX: 000000000000004b [ 691.490242] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f4b253ad5f0 [ 691.490244] RDX: 00007fffbb2d5fe0 RSI: 00007fffbb2d5fe0 RDI: 0000000000000003 [ 691.490245] RBP: 000000000000000d R08: 0000000000000001 R09: 00007fffbb2d608c [ 691.490247] R10: 00000000000002e8 R11: 0000000000000246 R12: 00000000000001f4 [ 691.490248] R13: 0000000051eb851f R14: 00007fffbb2d6120 R15: 00005635a498bda0 This started happening recently when running some test cases from fstests like btrfs/004 for example, because support for rename exchange was added last week to fsstress from fstests. So fix this by deleting the log context for the source root from the list if we have logged the new name in the source root. Reported-by: Su Yue <Damenly_Su@gmx.com> Fixes: d4682ba03ef618 ("Btrfs: sync log after logging new name") CC: stable@vger.kernel.org # 4.19+ Tested-by: Su Yue <Damenly_Su@gmx.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* | | | Merge tag 'configfs-for-5.4-2' of git://git.infradead.org/users/hch/configfsLinus Torvalds2019-11-101-1/+1
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull configfs regression fix from Christoph Hellwig: "Fix a regression from this merge window in the configfs symlink handling (Honggang Li)" * tag 'configfs-for-5.4-2' of git://git.infradead.org/users/hch/configfs: configfs: calculate the depth of parent item
| * | | | configfs: calculate the depth of parent itemHonggang Li2019-11-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When create symbolic link, create_link should calculate the depth of the parent item. However, both the first and second parameters of configfs_get_target_path had been set to the target. Broken symbolic link created. $ targetcli ls / o- / ............................................................. [...] o- backstores .................................................. [...] | o- block ...................................... [Storage Objects: 0] | o- fileio ..................................... [Storage Objects: 2] | | o- vdev0 .......... [/dev/ramdisk1 (16.0MiB) write-thru activated] | | | o- alua ....................................... [ALUA Groups: 1] | | | o- default_tg_pt_gp ........... [ALUA state: Active/optimized] | | o- vdev1 .......... [/dev/ramdisk2 (16.0MiB) write-thru activated] | | o- alua ....................................... [ALUA Groups: 1] | | o- default_tg_pt_gp ........... [ALUA state: Active/optimized] | o- pscsi ...................................... [Storage Objects: 0] | o- ramdisk .................................... [Storage Objects: 0] o- iscsi ................................................ [Targets: 0] o- loopback ............................................. [Targets: 0] o- srpt ................................................. [Targets: 2] | o- ib.e89a8f91cb3200000000000000000000 ............... [no-gen-acls] | | o- acls ................................................ [ACLs: 2] | | | o- ib.e89a8f91cb3200000000000000000000 ........ [Mapped LUNs: 2] | | | | o- mapped_lun0 ............................. [BROKEN LUN LINK] | | | | o- mapped_lun1 ............................. [BROKEN LUN LINK] | | | o- ib.e89a8f91cb3300000000000000000000 ........ [Mapped LUNs: 2] | | | o- mapped_lun0 ............................. [BROKEN LUN LINK] | | | o- mapped_lun1 ............................. [BROKEN LUN LINK] | | o- luns ................................................ [LUNs: 2] | | o- lun0 ...... [fileio/vdev0 (/dev/ramdisk1) (default_tg_pt_gp)] | | o- lun1 ...... [fileio/vdev1 (/dev/ramdisk2) (default_tg_pt_gp)] | o- ib.e89a8f91cb3300000000000000000000 ............... [no-gen-acls] | o- acls ................................................ [ACLs: 0] | o- luns ................................................ [LUNs: 0] o- vhost ................................................ [Targets: 0] Fixes: e9c03af21cc7 ("configfs: calculate the symlink target only once") Signed-off-by: Honggang Li <honli@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
* | | | | Merge tag '5.4-rc7-smb3-fix' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds2019-11-101-0/+1
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull cifs fix from Steve French: "Small fix for an smb3 reconnect bug (also marked for stable)" * tag '5.4-rc7-smb3-fix' of git://git.samba.org/sfrench/cifs-2.6: SMB3: Fix persistent handles reconnect
| * | | | | SMB3: Fix persistent handles reconnectPavel Shilovsky2019-11-061-0/+1
| |/ / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the client hits a network reconnect, it re-opens every open file with a create context to reconnect a persistent handle. All create context types should be 8-bytes aligned but the padding was missed for that one. As a result, some servers don't allow us to reconnect handles and return an error. The problem occurs when the problematic context is not at the end of the create request packet. Fix this by adding a proper padding at the end of the reconnect persistent handle context. Cc: Stable <stable@vger.kernel.org> # 4.19.x Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
* | | | | Merge tag 'for-5.4-rc6-tag' of ↵Linus Torvalds2019-11-095-15/+36
|\ \ \ \ \ | | |/ / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "A few regressions and fixes for stable. Regressions: - fix a race leading to metadata space leak after task received a signal - un-deprecate 2 ioctls, marked as deprecated by mistake Fixes: - fix limit check for number of devices during chunk allocation - fix a race due to double evaluation of i_size_read inside max() macro, can cause a crash - remove wrong device id check in tree-checker" * tag 'for-5.4-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: un-deprecate ioctls START_SYNC and WAIT_SYNC btrfs: save i_size to avoid double evaluation of i_size_read in compress_file_range Btrfs: fix race leading to metadata space leak after task received signal btrfs: tree-checker: Fix wrong check on max devid btrfs: Consider system chunk array size for new SYSTEM chunks
| * | | | btrfs: un-deprecate ioctls START_SYNC and WAIT_SYNCDavid Sterba2019-11-041-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The two ioctls START_SYNC and WAIT_SYNC were mistakenly marked as deprecated and scheduled for removal but we actualy do use them for 'btrfs subvolume delete -C/-c'. The deprecated thing in ebc87351e5fc should have been just the async flag for subvolume creation. The deprecation has been added in this development cycle, remove it until it's time. Fixes: ebc87351e5fc ("btrfs: Deprecate BTRFS_SUBVOL_CREATE_ASYNC flag") Signed-off-by: David Sterba <dsterba@suse.com>
| * | | | btrfs: save i_size to avoid double evaluation of i_size_read in ↵Josef Bacik2019-11-041-1/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | compress_file_range We hit a regression while rolling out 5.2 internally where we were hitting the following panic kernel BUG at mm/page-writeback.c:2659! RIP: 0010:clear_page_dirty_for_io+0xe6/0x1f0 Call Trace: __process_pages_contig+0x25a/0x350 ? extent_clear_unlock_delalloc+0x43/0x70 submit_compressed_extents+0x359/0x4d0 normal_work_helper+0x15a/0x330 process_one_work+0x1f5/0x3f0 worker_thread+0x2d/0x3d0 ? rescuer_thread+0x340/0x340 kthread+0x111/0x130 ? kthread_create_on_node+0x60/0x60 ret_from_fork+0x1f/0x30 This is happening because the page is not locked when doing clear_page_dirty_for_io. Looking at the core dump it was because our async_extent had a ram_size of 24576 but our async_chunk range only spanned 20480, so we had a whole extra page in our ram_size for our async_extent. This happened because we try not to compress pages outside of our i_size, however a cleanup patch changed us to do actual_end = min_t(u64, i_size_read(inode), end + 1); which is problematic because i_size_read() can evaluate to different values in between checking and assigning. So either an expanding truncate or a fallocate could increase our i_size while we're doing writeout and actual_end would end up being past the range we have locked. I confirmed this was what was happening by installing a debug kernel that had actual_end = min_t(u64, i_size_read(inode), end + 1); if (actual_end > end + 1) { printk(KERN_ERR "KABOOM\n"); actual_end = end + 1; } and installing it onto 500 boxes of the tier that had been seeing the problem regularly. Last night I got my debug message and no panic, confirming what I expected. [ dsterba: the assembly confirms a tiny race window: mov 0x20(%rsp),%rax cmp %rax,0x48(%r15) # read movl $0x0,0x18(%rsp) mov %rax,%r12 mov %r14,%rax cmovbe 0x48(%r15),%r12 # eval Where r15 is inode and 0x48 is offset of i_size. The original fix was to revert 62b37622718c that would do an intermediate assignment and this would also avoid the doulble evaluation but is not future-proof, should the compiler merge the stores and call i_size_read anyway. There's a patch adding READ_ONCE to i_size_read but that's not being applied at the moment and we need to fix the bug. Instead, emulate READ_ONCE by two barrier()s that's what effectively happens. The assembly confirms single evaluation: mov 0x48(%rbp),%rax # read once mov 0x20(%rsp),%rcx mov $0x20,%edx cmp %rax,%rcx cmovbe %rcx,%rax mov %rax,(%rsp) mov %rax,%rcx mov %r14,%rax Where 0x48(%rbp) is inode->i_size stored to %eax. ] Fixes: 62b37622718c ("btrfs: Remove isize local variable in compress_file_range") CC: stable@vger.kernel.org # v5.1+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> [ changelog updated ] Signed-off-by: David Sterba <dsterba@suse.com>
| * | | | Btrfs: fix race leading to metadata space leak after task received signalFilipe Manana2019-10-251-0/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a task that is allocating metadata needs to wait for the async reclaim job to process its ticket and gets a signal (because it was killed for example) before doing the wait, the task ends up erroring out but with space reserved for its ticket, which never gets released, resulting in a metadata space leak (more specifically a leak in the bytes_may_use counter of the metadata space_info object). Here's the sequence of steps leading to the space leak: 1) A task tries to create a file for example, so it ends up trying to start a transaction at btrfs_create(); 2) The filesystem is currently in a state where there is not enough metadata free space to satisfy the transaction's needs. So at space-info.c:__reserve_metadata_bytes() we create a ticket and add it to the list of tickets of the space info object. Also, because the metadata async reclaim job is not running, we queue a job ro run metadata reclaim; 3) In the meanwhile the task receives a signal (like SIGTERM from a kill command for example); 4) After queing the async reclaim job, at __reserve_metadata_bytes(), we unlock the metadata space info and call handle_reserve_ticket(); 5) That last function calls wait_reserve_ticket(), which acquires the lock from the metadata space info. Then in the first iteration of its while loop, it calls prepare_to_wait_event(), which returns -ERESTARTSYS because the task has a pending signal. As a result, we set the error field of the ticket to -EINTR and exit the while loop without deleting the ticket from the list of tickets (in the space info object). After exiting the loop we unlock the space info; 6) The async reclaim job is able to release enough metadata, acquires the metadata space info's lock and then reserves space for the ticket, since the ticket is still in the list of (non-priority) tickets. The space reservation happens at btrfs_try_granting_tickets(), called from maybe_fail_all_tickets(). This increments the bytes_may_use counter from the metadata space info object, sets the ticket's bytes field to zero (meaning success, that space was reserved) and removes it from the list of tickets; 7) wait_reserve_ticket() returns, with the error field of the ticket set to -EINTR. Then handle_reserve_ticket() just propagates that error to the caller. Because an error was returned, the caller does not release the reserved space, since the expectation is that any error means no space was reserved. Fix this by removing the ticket from the list, while holding the space info lock, at wait_reserve_ticket() when prepare_to_wait_event() returns an error. Also add some comments and an assertion to guarantee we never end up with a ticket that has an error set and a bytes counter field set to zero, to more easily detect regressions in the future. This issue could be triggered sporadically by some test cases from fstests such as generic/269 for example, which tries to fill a filesystem and then kills fsstress processes running in the background. When this issue happens, we get a warning in syslog/dmesg when unmounting the filesystem, like the following: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 13240 at fs/btrfs/block-group.c:3186 btrfs_free_block_groups+0x314/0x470 [btrfs] (...) CPU: 0 PID: 13240 Comm: umount Tainted: G W L 5.3.0-rc8-btrfs-next-48+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014 RIP: 0010:btrfs_free_block_groups+0x314/0x470 [btrfs] (...) RSP: 0018:ffff9910c14cfdb8 EFLAGS: 00010286 RAX: 0000000000000024 RBX: ffff89cd8a4d55f0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff89cdf6a178a8 RDI: ffff89cdf6a178a8 RBP: ffff9910c14cfde8 R08: 0000000000000000 R09: 0000000000000001 R10: ffff89cd4d618040 R11: 0000000000000000 R12: ffff89cd8a4d5508 R13: ffff89cde7c4a600 R14: dead000000000122 R15: dead000000000100 FS: 00007f42754432c0(0000) GS:ffff89cdf6a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd25a47f730 CR3: 000000021f8d6006 CR4: 00000000003606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: close_ctree+0x1ad/0x390 [btrfs] generic_shutdown_super+0x6c/0x110 kill_anon_super+0xe/0x30 btrfs_kill_super+0x12/0xa0 [btrfs] deactivate_locked_super+0x3a/0x70 cleanup_mnt+0xb4/0x160 task_work_run+0x7e/0xc0 exit_to_usermode_loop+0xfa/0x100 do_syscall_64+0x1cb/0x220 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f4274d2cb37 (...) RSP: 002b:00007ffcff701d38 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000557ebde2f060 RCX: 00007f4274d2cb37 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000557ebde2f240 RBP: 0000557ebde2f240 R08: 0000557ebde2f270 R09: 0000000000000015 R10: 00000000000006b4 R11: 0000000000000246 R12: 00007f427522ee64 R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffcff701fc0 irq event stamp: 0 hardirqs last enabled at (0): [<0000000000000000>] 0x0 hardirqs last disabled at (0): [<ffffffffb12b561e>] copy_process+0x75e/0x1fd0 softirqs last enabled at (0): [<ffffffffb12b561e>] copy_process+0x75e/0x1fd0 softirqs last disabled at (0): [<0000000000000000>] 0x0 ---[ end trace bcf4b235461b26f6 ]--- BTRFS info (device sdb): space_info 4 has 19116032 free, is full BTRFS info (device sdb): space_info total=33554432, used=14176256, pinned=0, reserved=0, may_use=196608, readonly=65536 BTRFS info (device sdb): global_block_rsv: size 0 reserved 0 BTRFS info (device sdb): trans_block_rsv: size 0 reserved 0 BTRFS info (device sdb): chunk_block_rsv: size 0 reserved 0 BTRFS info (device sdb): delayed_block_rsv: size 0 reserved 0 BTRFS info (device sdb): delayed_refs_rsv: size 0 reserved 0 Fixes: 374bf9c5cd7d0b ("btrfs: unify error handling for ticket flushing") Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
| * | | | btrfs: tree-checker: Fix wrong check on max devidQu Wenruo2019-10-251-8/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [BUG] The following script will cause false alert on devid check. #!/bin/bash dev1=/dev/test/test dev2=/dev/test/scratch1 mnt=/mnt/btrfs umount $dev1 &> /dev/null umount $dev2 &> /dev/null umount $mnt &> /dev/null mkfs.btrfs -f $dev1 mount $dev1 $mnt _fail() { echo "!!! FAILED !!!" exit 1 } for ((i = 0; i < 4096; i++)); do btrfs dev add -f $dev2 $mnt || _fail btrfs dev del $dev1 $mnt || _fail dev_tmp=$dev1 dev1=$dev2 dev2=$dev_tmp done [CAUSE] Tree-checker uses BTRFS_MAX_DEVS() and BTRFS_MAX_DEVS_SYS_CHUNK() as upper limit for devid. But we can have devid holes just like above script. So the check for devid is incorrect and could cause false alert. [FIX] Just remove the whole devid check. We don't have any hard requirement for devid assignment. Furthermore, even devid could get corrupted by a bitflip, we still have dev extents verification at mount time, so corrupted data won't sneak in. This fixes fstests btrfs/194. Reported-by: Anand Jain <anand.jain@oracle.com> Fixes: ab4ba2e13346 ("btrfs: tree-checker: Verify dev item") CC: stable@vger.kernel.org # 5.2+ Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
| * | | | btrfs: Consider system chunk array size for new SYSTEM chunksQu Wenruo2019-10-251-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For SYSTEM chunks, despite the regular chunk item size limit, there is another limit due to system chunk array size. The extra limit was removed in a refactoring, so add it back. Fixes: e3ecdb3fdecf ("btrfs: factor out devs_max setting in __btrfs_alloc_chunk") CC: stable@vger.kernel.org # 5.3+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* | | | | Merge tag 'for-linus-2019-11-08' of git://git.kernel.dk/linux-blockLinus Torvalds2019-11-081-3/+6
|\ \ \ \ \ | | |_|_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block fixes from Jens Axboe: - Two NVMe device removal crash fixes, and a compat fixup for for an ioctl that was introduced in this release (Anton, Charles, Max - via Keith) - Missing error path mutex unlock for drbd (Dan) - cgroup writeback fixup on dead memcg (Tejun) - blkcg online stats print fix (Tejun) * tag 'for-linus-2019-11-08' of git://git.kernel.dk/linux-block: cgroup,writeback: don't switch wbs immediately on dead wbs if the memcg is dead block: drbd: remove a stray unlock in __drbd_send_protocol() blkcg: make blkcg_print_stat() print stats only for online blkgs nvme: change nvme_passthru_cmd64 to explicitly mark rsvd nvme-multipath: fix crash in nvme_mpath_clear_ctrl_paths nvme-rdma: fix a segmentation fault during module unload
| * | | | cgroup,writeback: don't switch wbs immediately on dead wbs if the memcg is deadTejun Heo2019-11-081-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cgroup writeback tries to refresh the associated wb immediately if the current wb is dead. This is to avoid keeping issuing IOs on the stale wb after memcg - blkcg association has changed (ie. when blkcg got disabled / enabled higher up in the hierarchy). Unfortunately, the logic gets triggered spuriously on inodes which are associated with dead cgroups. When the logic is triggered on dead cgroups, the attempt fails only after doing quite a bit of work allocating and initializing a new wb. While c3aab9a0bd91 ("mm/filemap.c: don't initiate writeback if mapping has no dirty pages") alleviated the issue significantly as it now only triggers when the inode has dirty pages. However, the condition can still be triggered before the inode is switched to a different cgroup and the logic simply doesn't make sense. Skip the immediate switching if the associated memcg is dying. This is a simplified version of the following two patches: * https://lore.kernel.org/linux-mm/20190513183053.GA73423@dennisz-mbp/ * http://lkml.kernel.org/r/156355839560.2063.5265687291430814589.stgit@buzz Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Fixes: e8a7abf5a5bd ("writeback: disassociate inodes from dying bdi_writebacks") Acked-by: Dennis Zhou <dennis@kernel.org> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | | | | Merge tag 'ceph-for-5.4-rc7' of git://github.com/ceph/ceph-clientLinus Torvalds2019-11-085-15/+37
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull ceph fixes from Ilya Dryomov: "Some late-breaking dentry handling fixes from Al and Jeff, a patch to further restrict copy_file_range() to avoid potential data corruption from Luis and a fix for !CONFIG_CEPH_FSCACHE kernels. Everything but the fscache fix is marked for stable" * tag 'ceph-for-5.4-rc7' of git://github.com/ceph/ceph-client: ceph: return -EINVAL if given fsc mount option on kernel w/o support ceph: don't allow copy_file_range when stripe_count != 1 ceph: don't try to handle hashed dentries in non-O_CREAT atomic_open ceph: add missing check in d_revalidate snapdir handling ceph: fix RCU case handling in ceph_d_revalidate() ceph: fix use-after-free in __ceph_remove_cap()
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-09 11:59:53 +0000