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2017-01-19btrfs: fix error handling when run_delayed_extent_op failsJeff Mahoney
commit aa7c8da35d1905d80e840d075f07d26ec90144b5 upstream. In __btrfs_run_delayed_refs, the error path when run_delayed_extent_op fails sets locked_ref->processing = 0 but doesn't re-increment delayed_refs->num_heads_ready. As a result, we end up triggering the WARN_ON in btrfs_select_ref_head. Fixes: d7df2c796d7 (Btrfs: attach delayed ref updates to delayed ref heads) Reported-by: Jon Nelson <jnelson-suse@jamponi.net> Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-19btrfs: fix locking when we put back a delayed ref that's too newJeff Mahoney
commit d0280996437081dd12ed1e982ac8aeaa62835ec4 upstream. In __btrfs_run_delayed_refs, when we put back a delayed ref that's too new, we have already dropped the lock on locked_ref when we set ->processing = 0. This patch keeps the lock to cover that assignment. Fixes: d7df2c796d7 (Btrfs: attach delayed ref updates to delayed ref heads) Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-06btrfs: make file clone aware of fatal signalsWang Xiaoguang
commit 69ae5e4459e43e56f03d0987e865fbac2b05af2a upstream. Indeed this just make the behavior similar to xfs when process has fatal signals pending, and it'll make fstests/generic/298 happy. Signed-off-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.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>
2017-01-06Btrfs: don't BUG() during drop snapshotJosef Bacik
commit 4867268c57ff709a7b6b86ae6f6537d846d1443a upstream. Really there's lots of things that can go wrong here, kill all the BUG_ON()'s and replace the logic ones with ASSERT()'s and return EIO instead. Signed-off-by: Josef Bacik <jbacik@fb.com> [ switched to btrfs_err, errors go to common label ] Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-06Btrfs: fix memory leak in do_walk_downLiu Bo
commit a958eab0ed7fdc1b977bc25d3af6efedaa945488 upstream. The extent buffer 'next' needs to be free'd conditionally. Signed-off-by: Liu Bo <bo.li.liu@oracle.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>
2017-01-06Btrfs: don't leak reloc root nodes on errorJosef Bacik
commit 6bdf131fac2336adb1a628f992ba32384f653a55 upstream. We don't track the reloc roots in any sort of normal way, so the only way the root/commit_root nodes get free'd is if the relocation finishes successfully and the reloc root is deleted. Fix this by free'ing them in free_reloc_roots. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-06Btrfs: return gracefully from balance if fs tree is corruptedLiu Bo
commit 3561b9db70928f207be4570b48fc19898eeaef54 upstream. When relocating tree blocks, we firstly get block information from back references in the extent tree, we then search fs tree to try to find all parents of a block. However, if fs tree is corrupted, eg. if there're some missing items, we could come across these WARN_ONs and BUG_ONs. This makes us print some error messages and return gracefully from balance. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-06Btrfs: bail out if block group has different mixed flagLiu Bo
commit 49303381f19ab16a371a061b67e783d3f570d56e upstream. Currently we allow inconsistence about mixed flag (BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA). We'd get ENOSPC if block group has mixed flag and btrfs doesn't. If that happens, we have one space_info with mixed flag and another space_info only with BTRFS_BLOCK_GROUP_METADATA, and global_block_rsv.space_info points to the latter one, but all bytes from block_group contributes to the mixed space_info, thus all the allocation will fail with ENOSPC. This adds a check for the above case. Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> [ updated message ] Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-06Btrfs: fix memory leak in reading btree blocksLiu Bo
commit 2571e739677f1e4c0c63f5ed49adcc0857923625 upstream. So we can read a btree block via readahead or intentional read, and we can end up with a memory leak when something happens as follows, 1) readahead starts to read block A but does not wait for read completion, 2) btree_readpage_end_io_hook finds that block A is corrupted, and it needs to clear all block A's pages' uptodate bit. 3) meanwhile an intentional read kicks in and checks block A's pages' uptodate to decide which page needs to be read. 4) when some pages have the uptodate bit during 3)'s check so 3) doesn't count them for eb->io_pages, but they are later cleared by 2) so we has to readpage on the page, we get the wrong eb->io_pages which results in a memory leak of this block. This fixes the problem by firstly getting all pages's locking and then checking pages' uptodate bit. t1(readahead) t2(readahead endio) t3(the following read) read_extent_buffer_pages end_bio_extent_readpage for pg in eb: for page 0,1,2 in eb: if pg is uptodate: btree_readpage_end_io_hook(pg) num_reads++ if uptodate: eb->io_pages = num_reads SetPageUptodate(pg) _______________ for pg in eb: for page 3 in eb: read_extent_buffer_pages if pg is NOT uptodate: btree_readpage_end_io_hook(pg) for pg in eb: __extent_read_full_page(pg) sanity check reports something wrong if pg is uptodate: clear_extent_buffer_uptodate(eb) num_reads++ for pg in eb: eb->io_pages = num_reads ClearPageUptodate(page) _______________ for pg in eb: if pg is NOT uptodate: __extent_read_full_page(pg) So t3's eb->io_pages is not consistent with the number of pages it's reading, and during endio(), atomic_dec_and_test(&eb->io_pages) will get a negative number so that we're not able to free the eb. Signed-off-by: Liu Bo <bo.li.liu@oracle.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>
2017-01-06Btrfs: fix qgroup rescan worker initializationFilipe Manana
commit 8d9eddad19467b008e0c881bc3133d7da94b7ec1 upstream. We were setting the qgroup_rescan_running flag to true only after the rescan worker started (which is a task run by a queue). So if a user space task starts a rescan and immediately after asks to wait for the rescan worker to finish, this second call might happen before the rescan worker task starts running, in which case the rescan wait ioctl returns immediatley, not waiting for the rescan worker to finish. This was making the fstest btrfs/022 fail very often. Fixes: d2c609b834d6 (btrfs: properly track when rescan worker is running) Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-06btrfs: store and load values of stripes_min/stripes_max in balance status itemDavid Sterba
commit ed0df618b1b06d7431ee4d985317fc5419a5d559 upstream. The balance status item contains currently known filter values, but the stripes filter was unintentionally not among them. This would mean, that interrupted and automatically restarted balance does not apply the stripe filters. Fixes: dee32d0ac3719ef8d640efaf0884111df444730f Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-06Btrfs: fix tree search logic when replaying directory entry deletesRobbie Ko
commit 2a7bf53f577e49c43de4ffa7776056de26db65d9 upstream. If a log tree has a layout like the following: leaf N: ... item 240 key (282 DIR_LOG_ITEM 0) itemoff 8189 itemsize 8 dir log end 1275809046 leaf N + 1: item 0 key (282 DIR_LOG_ITEM 3936149215) itemoff 16275 itemsize 8 dir log end 18446744073709551615 ... When we pass the value 1275809046 + 1 as the parameter start_ret to the function tree-log.c:find_dir_range() (done by replay_dir_deletes()), we end up with path->slots[0] having the value 239 (points to the last item of leaf N, item 240). Because the dir log item in that position has an offset value smaller than *start_ret (1275809046 + 1) we need to move on to the next leaf, however the logic for that is wrong since it compares the current slot to the number of items in the leaf, which is smaller and therefore we don't lookup for the next leaf but instead we set the slot to point to an item that does not exist, at slot 240, and we later operate on that slot which has unexpected content or in the worst case can result in an invalid memory access (accessing beyond the last page of leaf N's extent buffer). So fix the logic that checks when we need to lookup at the next leaf by first incrementing the slot and only after to check if that slot is beyond the last item of the current leaf. Signed-off-by: Robbie Ko <robbieko@synology.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Fixes: e02119d5a7b4 (Btrfs: Add a write ahead tree log to optimize synchronous operations) Signed-off-by: Filipe Manana <fdmanana@suse.com> [Modified changelog for clarity and correctness] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-06btrfs: limit async_work allocation and worker func durationMaxim Patlasov
commit 2939e1a86f758b55cdba73e29397dd3d94df13bc upstream. Problem statement: unprivileged user who has read-write access to more than one btrfs subvolume may easily consume all kernel memory (eventually triggering oom-killer). Reproducer (./mkrmdir below essentially loops over mkdir/rmdir): [root@kteam1 ~]# cat prep.sh DEV=/dev/sdb mkfs.btrfs -f $DEV mount $DEV /mnt for i in `seq 1 16` do mkdir /mnt/$i btrfs subvolume create /mnt/SV_$i ID=`btrfs subvolume list /mnt |grep "SV_$i$" |cut -d ' ' -f 2` mount -t btrfs -o subvolid=$ID $DEV /mnt/$i chmod a+rwx /mnt/$i done [root@kteam1 ~]# sh prep.sh [maxim@kteam1 ~]$ for i in `seq 1 16`; do ./mkrmdir /mnt/$i 2000 2000 & done [root@kteam1 ~]# for i in `seq 1 4`; do grep "kmalloc-128" /proc/slabinfo | grep -v dma; sleep 60; done kmalloc-128 10144 10144 128 32 1 : tunables 0 0 0 : slabdata 317 317 0 kmalloc-128 9992352 9992352 128 32 1 : tunables 0 0 0 : slabdata 312261 312261 0 kmalloc-128 24226752 24226752 128 32 1 : tunables 0 0 0 : slabdata 757086 757086 0 kmalloc-128 42754240 42754240 128 32 1 : tunables 0 0 0 : slabdata 1336070 1336070 0 The huge numbers above come from insane number of async_work-s allocated and queued by btrfs_wq_run_delayed_node. The problem is caused by btrfs_wq_run_delayed_node() queuing more and more works if the number of delayed items is above BTRFS_DELAYED_BACKGROUND. The worker func (btrfs_async_run_delayed_root) processes at least BTRFS_DELAYED_BATCH items (if they are present in the list). So, the machinery works as expected while the list is almost empty. As soon as it is getting bigger, worker func starts to process more than one item at a time, it takes longer, and the chances to have async_works queued more than needed is getting higher. The problem above is worsened by another flaw of delayed-inode implementation: if async_work was queued in a throttling branch (number of items >= BTRFS_DELAYED_WRITEBACK), corresponding worker func won't quit until the number of items < BTRFS_DELAYED_BACKGROUND / 2. So, it is possible that the func occupies CPU infinitely (up to 30sec in my experiments): while the func is trying to drain the list, the user activity may add more and more items to the list. The patch fixes both problems in straightforward way: refuse queuing too many works in btrfs_wq_run_delayed_node and bail out of worker func if at least BTRFS_DELAYED_WRITEBACK items are processed. Changed in v2: remove support of thresh == NO_THRESHOLD. Signed-off-by: Maxim Patlasov <mpatlasov@virtuozzo.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-18btrfs: qgroup: Prevent qgroup->reserved from going subzeroGoldwyn Rodrigues
commit 0b34c261e235a5c74dcf78bd305845bd15fe2b42 upstream. While free'ing qgroup->reserved resources, we much check if the page has not been invalidated by a truncate operation by checking if the page is still dirty before reducing the qgroup resources. Resources in such a case are free'd when the entire extent is released by delayed_ref. This fixes a double accounting while releasing resources in case of truncating a file, reproduced by the following testcase. SCRATCH_DEV=/dev/vdb SCRATCH_MNT=/mnt mkfs.btrfs -f $SCRATCH_DEV mount -t btrfs $SCRATCH_DEV $SCRATCH_MNT cd $SCRATCH_MNT btrfs quota enable $SCRATCH_MNT btrfs subvolume create a btrfs qgroup limit 500m a $SCRATCH_MNT sync for c in {1..15}; do dd if=/dev/zero bs=1M count=40 of=$SCRATCH_MNT/a/file; done sleep 10 sync sleep 5 touch $SCRATCH_MNT/a/newfile echo "Removing file" rm $SCRATCH_MNT/a/file Fixes: b9d0b38928 ("btrfs: Add handler for invalidate page") Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-10btrfs: fix races on root_log_ctx listsChris Mason
commit 570dd45042a7c8a7aba1ee029c5dd0f5ccf41b9b upstream. btrfs_remove_all_log_ctxs takes a shortcut where it avoids walking the list because it knows all of the waiters are patiently waiting for the commit to finish. But, there's a small race where btrfs_sync_log can remove itself from the list if it finds a log commit is already done. Also, it uses list_del_init() to remove itself from the list, but there's no way to know if btrfs_remove_all_log_ctxs has already run, so we don't know for sure if it is safe to call list_del_init(). This gets rid of all the shortcuts for btrfs_remove_all_log_ctxs(), and just calls it with the proper locking. This is part two of the corruption fixed by cbd60aa7cd1. I should have done this in the first place, but convinced myself the optimizations were safe. A 12 hour run of dbench 2048 will eventually trigger a list debug WARN_ON for the list_del_init() in btrfs_sync_log(). Fixes: d1433debe7f4346cf9fc0dafc71c3137d2a97bc4 Reported-by: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-31posix_acl: Clear SGID bit when setting file permissionsJan Kara
commit 073931017b49d9458aa351605b43a7e34598caef upstream. When file permissions are modified via chmod(2) and the user is not in the owning group or capable of CAP_FSETID, the setgid bit is cleared in inode_change_ok(). Setting a POSIX ACL via setxattr(2) sets the file permissions as well as the new ACL, but doesn't clear the setgid bit in a similar way; this allows to bypass the check in chmod(2). Fix that. References: CVE-2016-7097 Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-22btrfs: assign error values to the correct bio structsJunjie Mao
commit 14155cafeadda946376260e2ad5d39a0528a332f upstream. Fixes: 4246a0b63bd8 ("block: add a bi_error field to struct bio") Signed-off-by: Junjie Mao <junjie.mao@enight.me> Acked-by: David Sterba <dsterba@suse.cz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-30btrfs: ensure that file descriptor used with subvol ioctls is a dirJeff Mahoney
commit 325c50e3cebb9208009083e841550f98a863bfa0 upstream. If the subvol/snapshot create/destroy ioctls are passed a regular file with execute permissions set, we'll eventually Oops while trying to do inode->i_op->lookup via lookup_one_len. This patch ensures that the file descriptor refers to a directory. Fixes: cb8e70901d (Btrfs: Fix subvolume creation locking rules) Fixes: 76dda93c6a (Btrfs: add snapshot/subvolume destroy ioctl) Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-24Btrfs: remove root_log_ctx from ctx list before btrfs_sync_log returnsChris Mason
commit cbd60aa7cd17d81a434234268c55192862147439 upstream. We use a btrfs_log_ctx structure to pass information into the tree log commit, and get error values out. It gets added to a per log-transaction list which we walk when things go bad. Commit d1433debe added an optimization to skip waiting for the log commit, but didn't take root_log_ctx out of the list. This patch makes sure we remove things before exiting. Signed-off-by: Chris Mason <clm@fb.com> Fixes: d1433debe7f4346cf9fc0dafc71c3137d2a97bc4 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-15btrfs: Continue write in case of can_not_nocowZhao Lei
[ Upstream commit 4da2e26a2a32b174878744bd0f07db180c875f26 ] btrfs failed in xfstests btrfs/080 with -o nodatacow. Can be reproduced by following script: DEV=/dev/vdg MNT=/mnt/tmp umount $DEV &>/dev/null mkfs.btrfs -f $DEV mount -o nodatacow $DEV $MNT dd if=/dev/zero of=$MNT/test bs=1 count=2048 & btrfs subvolume snapshot -r $MNT $MNT/test_snap & wait -- We can see dd failed on NO_SPACE. Reason: __btrfs_buffered_write should run cow write when no_cow impossible, and current code is designed with above logic. But check_can_nocow() have 2 type of return value(0 and <0) on can_not_no_cow, and current code only continue write on first case, the second case happened in doing subvolume. Fix: Continue write when check_can_nocow() return 0 and <0. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-07btrfs: properly track when rescan worker is runningJeff Mahoney
commit d2c609b834d62f1e91f1635a27dca29f7806d3d6 upstream. The qgroup_flags field is overloaded such that it reflects the on-disk status of qgroups and the runtime state. The BTRFS_QGROUP_STATUS_FLAG_RESCAN flag is used to indicate that a rescan operation is in progress, but if the file system is unmounted while a rescan is running, the rescan operation is paused. If the file system is then mounted read-only, the flag will still be present but the rescan operation will not have been resumed. When we go to umount, btrfs_qgroup_wait_for_completion will see the flag and interpret it to mean that the rescan worker is still running and will wait for a completion that will never come. This patch uses a separate flag to indicate when the worker is running. The locking and state surrounding the qgroup rescan worker needs a lot of attention beyond this patch but this is enough to avoid a hung umount. Signed-off-by; Jeff Mahoney <jeffm@suse.com> Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Chris Mason <clm@fb.com>
2016-09-07btrfs: waiting on qgroup rescan should not always be interruptibleJeff Mahoney
commit d06f23d6a947c9abae41dc46be69a56baf36f436 upstream. We wait on qgroup rescan completion in three places: file system shutdown, the quota disable ioctl, and the rescan wait ioctl. If the user sends a signal while we're waiting, we continue happily along. This is expected behavior for the rescan wait ioctl. It's racy in the shutdown path but mostly works due to other unrelated synchronization points. In the quota disable path, it Oopses the kernel pretty much immediately. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-20block: add missing group association in bio-cloning functionsPaolo Valente
commit 20bd723ec6a3261df5e02250cd3a1fbb09a343f2 upstream. When a bio is cloned, the newly created bio must be associated with the same blkcg as the original bio (if BLK_CGROUP is enabled). If this operation is not performed, then the new bio is not associated with any group, and the group of the current task is returned when the group of the bio is requested. Depending on the cloning frequency, this may cause a large percentage of the bios belonging to a given group to be treated as if belonging to other groups (in most cases as if belonging to the root group). The expected group isolation may thereby be broken. This commit adds the missing association in bio-cloning functions. Fixes: da2f0f74cf7d ("Btrfs: add support for blkio controllers") Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Reviewed-by: Nikolay Borisov <kernel@kyup.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-07-27btrfs: account for non-CoW'd blocks in btrfs_abort_transactionJeff Mahoney
commit 64c12921e11b3a0c10d088606e328c58e29274d8 upstream. The test for !trans->blocks_used in btrfs_abort_transaction is insufficient to determine whether it's safe to drop the transaction handle on the floor. btrfs_cow_block, informed by should_cow_block, can return blocks that have already been CoW'd in the current transaction. trans->blocks_used is only incremented for new block allocations. If an operation overlaps the blocks in the current transaction entirely and must abort the transaction, we'll happily let it clean up the trans handle even though it may have modified the blocks and will commit an incomplete operation. In the long-term, I'd like to do closer tracking of when the fs is actually modified so we can still recover as gracefully as possible, but that approach will need some discussion. In the short term, since this is the only code using trans->blocks_used, let's just switch it to a bool indicating whether any blocks were used and set it when should_cow_block returns false. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-01Btrfs: don't use src fd for printkJosef Bacik
commit c79b4713304f812d3d6c95826fc3e5fc2c0b0c14 upstream. The fd we pass in may not be on a btrfs file system, so don't try to do BTRFS_I() on it. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Cc: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-20Btrfs: fix file/data loss caused by fsync after rename and new inodeFilipe Manana
commit 56f23fdbb600e6087db7b009775b95ce07cc3195 upstream. If we rename an inode A (be it a file or a directory), create a new inode B with the old name of inode A and under the same parent directory, fsync inode B and then power fail, at log tree replay time we end up removing inode A completely. If inode A is a directory then all its files are gone too. Example scenarios where this happens: This is reproducible with the following steps, taken from a couple of test cases written for fstests which are going to be submitted upstream soon: # Scenario 1 mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir -p /mnt/a/x echo "hello" > /mnt/a/x/foo echo "world" > /mnt/a/x/bar sync mv /mnt/a/x /mnt/a/y mkdir /mnt/a/x xfs_io -c fsync /mnt/a/x <power failure happens> The next time the fs is mounted, log tree replay happens and the directory "y" does not exist nor do the files "foo" and "bar" exist anywhere (neither in "y" nor in "x", nor the root nor anywhere). # Scenario 2 mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir /mnt/a echo "hello" > /mnt/a/foo sync mv /mnt/a/foo /mnt/a/bar echo "world" > /mnt/a/foo xfs_io -c fsync /mnt/a/foo <power failure happens> The next time the fs is mounted, log tree replay happens and the file "bar" does not exists anymore. A file with the name "foo" exists and it matches the second file we created. Another related problem that does not involve file/data loss is when a new inode is created with the name of a deleted snapshot and we fsync it: mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir /mnt/testdir btrfs subvolume snapshot /mnt /mnt/testdir/snap btrfs subvolume delete /mnt/testdir/snap rmdir /mnt/testdir mkdir /mnt/testdir xfs_io -c fsync /mnt/testdir # or fsync some file inside /mnt/testdir <power failure> The next time the fs is mounted the log replay procedure fails because it attempts to delete the snapshot entry (which has dir item key type of BTRFS_ROOT_ITEM_KEY) as if it were a regular (non-root) entry, resulting in the following error that causes mount to fail: [52174.510532] BTRFS info (device dm-0): failed to delete reference to snap, inode 257 parent 257 [52174.512570] ------------[ cut here ]------------ [52174.513278] WARNING: CPU: 12 PID: 28024 at fs/btrfs/inode.c:3986 __btrfs_unlink_inode+0x178/0x351 [btrfs]() [52174.514681] BTRFS: Transaction aborted (error -2) [52174.515630] Modules linked in: btrfs dm_flakey dm_mod overlay crc32c_generic ppdev xor raid6_pq acpi_cpufreq parport_pc tpm_tis sg parport tpm evdev i2c_piix4 proc [52174.521568] CPU: 12 PID: 28024 Comm: mount Tainted: G W 4.5.0-rc6-btrfs-next-27+ #1 [52174.522805] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [52174.524053] 0000000000000000 ffff8801df2a7710 ffffffff81264e93 ffff8801df2a7758 [52174.524053] 0000000000000009 ffff8801df2a7748 ffffffff81051618 ffffffffa03591cd [52174.524053] 00000000fffffffe ffff88015e6e5000 ffff88016dbc3c88 ffff88016dbc3c88 [52174.524053] Call Trace: [52174.524053] [<ffffffff81264e93>] dump_stack+0x67/0x90 [52174.524053] [<ffffffff81051618>] warn_slowpath_common+0x99/0xb2 [52174.524053] [<ffffffffa03591cd>] ? __btrfs_unlink_inode+0x178/0x351 [btrfs] [52174.524053] [<ffffffff81051679>] warn_slowpath_fmt+0x48/0x50 [52174.524053] [<ffffffffa03591cd>] __btrfs_unlink_inode+0x178/0x351 [btrfs] [52174.524053] [<ffffffff8118f5e9>] ? iput+0xb0/0x284 [52174.524053] [<ffffffffa0359fe8>] btrfs_unlink_inode+0x1c/0x3d [btrfs] [52174.524053] [<ffffffffa038631e>] check_item_in_log+0x1fe/0x29b [btrfs] [52174.524053] [<ffffffffa0386522>] replay_dir_deletes+0x167/0x1cf [btrfs] [52174.524053] [<ffffffffa038739e>] fixup_inode_link_count+0x289/0x2aa [btrfs] [52174.524053] [<ffffffffa038748a>] fixup_inode_link_counts+0xcb/0x105 [btrfs] [52174.524053] [<ffffffffa038a5ec>] btrfs_recover_log_trees+0x258/0x32c [btrfs] [52174.524053] [<ffffffffa03885b2>] ? replay_one_extent+0x511/0x511 [btrfs] [52174.524053] [<ffffffffa034f288>] open_ctree+0x1dd4/0x21b9 [btrfs] [52174.524053] [<ffffffffa032b753>] btrfs_mount+0x97e/0xaed [btrfs] [52174.524053] [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf [52174.524053] [<ffffffff8117bafa>] mount_fs+0x67/0x131 [52174.524053] [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde [52174.524053] [<ffffffffa032af81>] btrfs_mount+0x1ac/0xaed [btrfs] [52174.524053] [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf [52174.524053] [<ffffffff8108c262>] ? lockdep_init_map+0xb9/0x1b3 [52174.524053] [<ffffffff8117bafa>] mount_fs+0x67/0x131 [52174.524053] [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde [52174.524053] [<ffffffff8119590f>] do_mount+0x8a6/0x9e8 [52174.524053] [<ffffffff811358dd>] ? strndup_user+0x3f/0x59 [52174.524053] [<ffffffff81195c65>] SyS_mount+0x77/0x9f [52174.524053] [<ffffffff814935d7>] entry_SYSCALL_64_fastpath+0x12/0x6b [52174.561288] ---[ end trace 6b53049efb1a3ea6 ]--- Fix this by forcing a transaction commit when such cases happen. This means we check in the commit root of the subvolume tree if there was any other inode with the same reference when the inode we are fsync'ing is a new inode (created in the current transaction). Test cases for fstests, covering all the scenarios given above, were submitted upstream for fstests: * fstests: generic test for fsync after renaming directory https://patchwork.kernel.org/patch/8694281/ * fstests: generic test for fsync after renaming file https://patchwork.kernel.org/patch/8694301/ * fstests: add btrfs test for fsync after snapshot deletion https://patchwork.kernel.org/patch/8670671/ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-20btrfs: fix crash/invalid memory access on fsync when using overlayfsFilipe Manana
commit de17e793b104d690e1d007dfc5cb6b4f649598ca upstream. If the lower or upper directory of an overlayfs mount belong to a btrfs file system and we fsync the file through the overlayfs' merged directory we ended up accessing an inode that didn't belong to btrfs as if it were a btrfs inode at btrfs_sync_file() resulting in a crash like the following: [ 7782.588845] BUG: unable to handle kernel NULL pointer dereference at 0000000000000544 [ 7782.590624] IP: [<ffffffffa030b7ab>] btrfs_sync_file+0x11b/0x3e9 [btrfs] [ 7782.591931] PGD 4d954067 PUD 1e878067 PMD 0 [ 7782.592016] Oops: 0002 [#6] PREEMPT SMP DEBUG_PAGEALLOC [ 7782.592016] Modules linked in: btrfs overlay ppdev crc32c_generic evdev xor raid6_pq psmouse pcspkr sg serio_raw acpi_cpufreq parport_pc parport tpm_tis i2c_piix4 tpm i2c_core processor button loop autofs4 ext4 crc16 mbcache jbd2 sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix virtio_pci libata virtio_ring virtio scsi_mod e1000 floppy [last unloaded: btrfs] [ 7782.592016] CPU: 10 PID: 16437 Comm: xfs_io Tainted: G D 4.5.0-rc6-btrfs-next-26+ #1 [ 7782.592016] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [ 7782.592016] task: ffff88001b8d40c0 ti: ffff880137488000 task.ti: ffff880137488000 [ 7782.592016] RIP: 0010:[<ffffffffa030b7ab>] [<ffffffffa030b7ab>] btrfs_sync_file+0x11b/0x3e9 [btrfs] [ 7782.592016] RSP: 0018:ffff88013748be40 EFLAGS: 00010286 [ 7782.592016] RAX: 0000000080000000 RBX: ffff880133b30c88 RCX: 0000000000000001 [ 7782.592016] RDX: 0000000000000001 RSI: ffffffff8148fec0 RDI: 00000000ffffffff [ 7782.592016] RBP: ffff88013748bec0 R08: 0000000000000001 R09: 0000000000000000 [ 7782.624248] R10: ffff88013748be40 R11: 0000000000000246 R12: 0000000000000000 [ 7782.624248] R13: 0000000000000000 R14: 00000000009305a0 R15: ffff880015e3be40 [ 7782.624248] FS: 00007fa83b9cb700(0000) GS:ffff88023ed40000(0000) knlGS:0000000000000000 [ 7782.624248] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 7782.624248] CR2: 0000000000000544 CR3: 00000001fa652000 CR4: 00000000000006e0 [ 7782.624248] Stack: [ 7782.624248] ffffffff8108b5cc ffff88013748bec0 0000000000000246 ffff8800b005ded0 [ 7782.624248] ffff880133b30d60 8000000000000000 7fffffffffffffff 0000000000000246 [ 7782.624248] 0000000000000246 ffffffff81074f9b ffffffff8104357c ffff880015e3be40 [ 7782.624248] Call Trace: [ 7782.624248] [<ffffffff8108b5cc>] ? arch_local_irq_save+0x9/0xc [ 7782.624248] [<ffffffff81074f9b>] ? ___might_sleep+0xce/0x217 [ 7782.624248] [<ffffffff8104357c>] ? __do_page_fault+0x3c0/0x43a [ 7782.624248] [<ffffffff811a2351>] vfs_fsync_range+0x8c/0x9e [ 7782.624248] [<ffffffff811a237f>] vfs_fsync+0x1c/0x1e [ 7782.624248] [<ffffffff811a24d6>] do_fsync+0x31/0x4a [ 7782.624248] [<ffffffff811a2700>] SyS_fsync+0x10/0x14 [ 7782.624248] [<ffffffff81493617>] entry_SYSCALL_64_fastpath+0x12/0x6b [ 7782.624248] Code: 85 c0 0f 85 e2 02 00 00 48 8b 45 b0 31 f6 4c 29 e8 48 ff c0 48 89 45 a8 48 8d 83 d8 00 00 00 48 89 c7 48 89 45 a0 e8 fc 43 18 e1 <f0> 41 ff 84 24 44 05 00 00 48 8b 83 58 ff ff ff 48 c1 e8 07 83 [ 7782.624248] RIP [<ffffffffa030b7ab>] btrfs_sync_file+0x11b/0x3e9 [btrfs] [ 7782.624248] RSP <ffff88013748be40> [ 7782.624248] CR2: 0000000000000544 [ 7782.661994] ---[ end trace 721e14960eb939bc ]--- This started happening since commit 4bacc9c9234 (overlayfs: Make f_path always point to the overlay and f_inode to the underlay) and even though after this change we could still access the btrfs inode through struct file->f_mapping->host or struct file->f_inode, we would end up resulting in more similar issues later on at check_parent_dirs_for_sync() because the dentry we got (from struct file->f_path.dentry) was from overlayfs and not from btrfs, that is, we had no way of getting the dentry that belonged to btrfs (we always got the dentry that belonged to overlayfs). The new patch from Miklos Szeredi, titled "vfs: add file_dentry()" and recently submitted to linux-fsdevel, adds a file_dentry() API that allows us to get the btrfs dentry from the input file and therefore being able to fsync when the upper and lower directories belong to btrfs filesystems. This issue has been reported several times by users in the mailing list and bugzilla. A test case for xfstests is being submitted as well. Fixes: 4bacc9c9234c ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay") Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=101951 Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=109791 Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-09Btrfs: fix loading of orphan roots leading to BUG_ONFilipe Manana
commit 909c3a22da3b8d2cfd3505ca5658f0176859d400 upstream. When looking for orphan roots during mount we can end up hitting a BUG_ON() (at root-item.c:btrfs_find_orphan_roots()) if a log tree is replayed and qgroups are enabled. This is because after a log tree is replayed, a transaction commit is made, which triggers qgroup extent accounting which in turn does backref walking which ends up reading and inserting all roots in the radix tree fs_info->fs_root_radix, including orphan roots (deleted snapshots). So after the log tree is replayed, when finding orphan roots we hit the BUG_ON with the following trace: [118209.182438] ------------[ cut here ]------------ [118209.183279] kernel BUG at fs/btrfs/root-tree.c:314! [118209.184074] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [118209.185123] Modules linked in: btrfs dm_flakey dm_mod crc32c_generic ppdev xor raid6_pq evdev sg parport_pc parport acpi_cpufreq tpm_tis tpm psmouse processor i2c_piix4 serio_raw pcspkr i2c_core button loop autofs4 ext4 crc16 mbcache jbd2 sd_mod sr_mod cdrom ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio scsi_mod e1000 floppy [last unloaded: btrfs] [118209.186318] CPU: 14 PID: 28428 Comm: mount Tainted: G W 4.5.0-rc5-btrfs-next-24+ #1 [118209.186318] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [118209.186318] task: ffff8801ec131040 ti: ffff8800af34c000 task.ti: ffff8800af34c000 [118209.186318] RIP: 0010:[<ffffffffa04237d7>] [<ffffffffa04237d7>] btrfs_find_orphan_roots+0x1fc/0x244 [btrfs] [118209.186318] RSP: 0018:ffff8800af34faa8 EFLAGS: 00010246 [118209.186318] RAX: 00000000ffffffef RBX: 00000000ffffffef RCX: 0000000000000001 [118209.186318] RDX: 0000000080000000 RSI: 0000000000000001 RDI: 00000000ffffffff [118209.186318] RBP: ffff8800af34fb08 R08: 0000000000000001 R09: 0000000000000000 [118209.186318] R10: ffff8800af34f9f0 R11: 6db6db6db6db6db7 R12: ffff880171b97000 [118209.186318] R13: ffff8801ca9d65e0 R14: ffff8800afa2e000 R15: 0000160000000000 [118209.186318] FS: 00007f5bcb914840(0000) GS:ffff88023edc0000(0000) knlGS:0000000000000000 [118209.186318] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [118209.186318] CR2: 00007f5bcaceb5d9 CR3: 00000000b49b5000 CR4: 00000000000006e0 [118209.186318] Stack: [118209.186318] fffffbffffffffff 010230ffffffffff 0101000000000000 ff84000000000000 [118209.186318] fbffffffffffffff 30ffffffffffffff 0000000000000101 ffff880082348000 [118209.186318] 0000000000000000 ffff8800afa2e000 ffff8800afa2e000 0000000000000000 [118209.186318] Call Trace: [118209.186318] [<ffffffffa042e2db>] open_ctree+0x1e37/0x21b9 [btrfs] [118209.186318] [<ffffffffa040a753>] btrfs_mount+0x97e/0xaed [btrfs] [118209.186318] [<ffffffff8108e1c0>] ? trace_hardirqs_on+0xd/0xf [118209.186318] [<ffffffff8117b87e>] mount_fs+0x67/0x131 [118209.186318] [<ffffffff81192d2b>] vfs_kern_mount+0x6c/0xde [118209.186318] [<ffffffffa0409f81>] btrfs_mount+0x1ac/0xaed [btrfs] [118209.186318] [<ffffffff8108e1c0>] ? trace_hardirqs_on+0xd/0xf [118209.186318] [<ffffffff8108c26b>] ? lockdep_init_map+0xb9/0x1b3 [118209.186318] [<ffffffff8117b87e>] mount_fs+0x67/0x131 [118209.186318] [<ffffffff81192d2b>] vfs_kern_mount+0x6c/0xde [118209.186318] [<ffffffff81195637>] do_mount+0x8a6/0x9e8 [118209.186318] [<ffffffff8119598d>] SyS_mount+0x77/0x9f [118209.186318] [<ffffffff81493017>] entry_SYSCALL_64_fastpath+0x12/0x6b [118209.186318] Code: 64 00 00 85 c0 89 c3 75 24 f0 41 80 4c 24 20 20 49 8b bc 24 f0 01 00 00 4c 89 e6 e8 e8 65 00 00 85 c0 89 c3 74 11 83 f8 ef 75 02 <0f> 0b 4c 89 e7 e8 da 72 00 00 eb 1c 41 83 bc 24 00 01 00 00 00 [118209.186318] RIP [<ffffffffa04237d7>] btrfs_find_orphan_roots+0x1fc/0x244 [btrfs] [118209.186318] RSP <ffff8800af34faa8> [118209.230735] ---[ end trace 83938f987d85d477 ]--- So fix this by not treating the error -EEXIST, returned when attempting to insert a root already inserted by the backref walking code, as an error. The following test case for xfstests reproduces the bug: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey cd / rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _supported_fs btrfs _supported_os Linux _require_scratch _require_dm_target flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey _run_btrfs_util_prog quota enable $SCRATCH_MNT # Create 2 directories with one file in one of them. # We use these just to trigger a transaction commit later, moving the file from # directory a to directory b and doing an fsync against directory a. mkdir $SCRATCH_MNT/a mkdir $SCRATCH_MNT/b touch $SCRATCH_MNT/a/f sync # Create our test file with 2 4K extents. $XFS_IO_PROG -f -s -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foobar | _filter_xfs_io # Create a snapshot and delete it. This doesn't really delete the snapshot # immediately, just makes it inaccessible and invisible to user space, the # snapshot is deleted later by a dedicated kernel thread (cleaner kthread) # which is woke up at the next transaction commit. # A root orphan item is inserted into the tree of tree roots, so that if a # power failure happens before the dedicated kernel thread does the snapshot # deletion, the next time the filesystem is mounted it resumes the snapshot # deletion. _run_btrfs_util_prog subvolume snapshot $SCRATCH_MNT $SCRATCH_MNT/snap _run_btrfs_util_prog subvolume delete $SCRATCH_MNT/snap # Now overwrite half of the extents we wrote before. Because we made a snapshpot # before, which isn't really deleted yet (since no transaction commit happened # after we did the snapshot delete request), the non overwritten extents get # referenced twice, once by the default subvolume and once by the snapshot. $XFS_IO_PROG -c "pwrite -S 0xbb 4K 8K" $SCRATCH_MNT/foobar | _filter_xfs_io # Now move file f from directory a to directory b and fsync directory a. # The fsync on the directory a triggers a transaction commit (because a file # was moved from it to another directory) and the file fsync leaves a log tree # with file extent items to replay. mv $SCRATCH_MNT/a/f $SCRATCH_MNT/a/b $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/a $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar echo "File digest before power failure:" md5sum $SCRATCH_MNT/foobar | _filter_scratch # Now simulate a power failure and mount the filesystem to replay the log tree. # After the log tree was replayed, we used to hit a BUG_ON() when processing # the root orphan item for the deleted snapshot. This is because when processing # an orphan root the code expected to be the first code inserting the root into # the fs_info->fs_root_radix radix tree, while in reallity it was the second # caller attempting to do it - the first caller was the transaction commit that # took place after replaying the log tree, when updating the qgroup counters. _flakey_drop_and_remount echo "File digest before after failure:" # Must match what he got before the power failure. md5sum $SCRATCH_MNT/foobar | _filter_scratch _unmount_flakey status=0 exit Fixes: 2d9e97761087 ("Btrfs: use btrfs_get_fs_root in resolve_indirect_ref") Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-09btrfs: async-thread: Fix a use-after-free error for traceQu Wenruo
commit 0a95b851370b84a4b9d92ee6d1fa0926901d0454 upstream. Parameter of trace_btrfs_work_queued() can be freed in its workqueue. So no one use use that pointer after queue_work(). Fix the user-after-free bug by move the trace line before queue_work(). Reported-by: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-09btrfs: Fix no_space in write and rm loopZhao Lei
commit e1746e8381cd2af421f75557b5cae3604fc18b35 upstream. I see no_space in v4.4-rc1 again in xfstests generic/102. It happened randomly in some node only. (one of 4 phy-node, and a kvm with non-virtio block driver) By bisect, we can found the first-bad is: commit bdced438acd8 ("block: setup bi_phys_segments after splitting")' But above patch only triggered the bug by making bio operation faster(or slower). Main reason is in our space_allocating code, we need to commit page writeback before wait it complish, this patch fixed above bug. BTW, there is another reason for generic/102 fail, caused by disable default mixed-blockgroup, I'll fix it in xfstests. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-09Btrfs: fix deadlock running delayed iputs at transaction commit timeFilipe Manana
commit c2d6cb1636d235257086f939a8194ef0bf93af6e upstream. While running a stress test I ran into a deadlock when running the delayed iputs at transaction time, which produced the following report and trace: [ 886.399989] ============================================= [ 886.400871] [ INFO: possible recursive locking detected ] [ 886.401663] 4.4.0-rc6-btrfs-next-18+ #1 Not tainted [ 886.402384] --------------------------------------------- [ 886.403182] fio/8277 is trying to acquire lock: [ 886.403568] (&fs_info->delayed_iput_sem){++++..}, at: [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.403568] [ 886.403568] but task is already holding lock: [ 886.403568] (&fs_info->delayed_iput_sem){++++..}, at: [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.403568] [ 886.403568] other info that might help us debug this: [ 886.403568] Possible unsafe locking scenario: [ 886.403568] [ 886.403568] CPU0 [ 886.403568] ---- [ 886.403568] lock(&fs_info->delayed_iput_sem); [ 886.403568] lock(&fs_info->delayed_iput_sem); [ 886.403568] [ 886.403568] *** DEADLOCK *** [ 886.403568] [ 886.403568] May be due to missing lock nesting notation [ 886.403568] [ 886.403568] 3 locks held by fio/8277: [ 886.403568] #0: (sb_writers#11){.+.+.+}, at: [<ffffffff81174c4c>] __sb_start_write+0x5f/0xb0 [ 886.403568] #1: (&sb->s_type->i_mutex_key#15){+.+.+.}, at: [<ffffffffa054620d>] btrfs_file_write_iter+0x73/0x408 [btrfs] [ 886.403568] #2: (&fs_info->delayed_iput_sem){++++..}, at: [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.403568] [ 886.403568] stack backtrace: [ 886.403568] CPU: 6 PID: 8277 Comm: fio Not tainted 4.4.0-rc6-btrfs-next-18+ #1 [ 886.403568] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [ 886.403568] 0000000000000000 ffff88009f80f770 ffffffff8125d4fd ffffffff82af1fc0 [ 886.403568] ffff88009f80f830 ffffffff8108e5f9 0000000200000000 ffff88009fd92290 [ 886.403568] 0000000000000000 ffffffff82af1fc0 ffffffff829cfb01 00042b216d008804 [ 886.403568] Call Trace: [ 886.403568] [<ffffffff8125d4fd>] dump_stack+0x4e/0x79 [ 886.403568] [<ffffffff8108e5f9>] __lock_acquire+0xd42/0xf0b [ 886.403568] [<ffffffff810c22db>] ? __module_address+0xdf/0x108 [ 886.403568] [<ffffffff8108eb77>] lock_acquire+0x10d/0x194 [ 886.403568] [<ffffffff8108eb77>] ? lock_acquire+0x10d/0x194 [ 886.403568] [<ffffffffa0538823>] ? btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.489542] [<ffffffff8148556b>] down_read+0x3e/0x4d [ 886.489542] [<ffffffffa0538823>] ? btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.489542] [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.489542] [<ffffffffa0533953>] btrfs_commit_transaction+0x8f5/0x96e [btrfs] [ 886.489542] [<ffffffffa0521d7a>] flush_space+0x435/0x44a [btrfs] [ 886.489542] [<ffffffffa052218b>] ? reserve_metadata_bytes+0x26a/0x384 [btrfs] [ 886.489542] [<ffffffffa05221ae>] reserve_metadata_bytes+0x28d/0x384 [btrfs] [ 886.489542] [<ffffffffa052256c>] ? btrfs_block_rsv_refill+0x58/0x96 [btrfs] [ 886.489542] [<ffffffffa0522584>] btrfs_block_rsv_refill+0x70/0x96 [btrfs] [ 886.489542] [<ffffffffa053d747>] btrfs_evict_inode+0x394/0x55a [btrfs] [ 886.489542] [<ffffffff81188e31>] evict+0xa7/0x15c [ 886.489542] [<ffffffff81189878>] iput+0x1d3/0x266 [ 886.489542] [<ffffffffa053887c>] btrfs_run_delayed_iputs+0x8f/0xbf [btrfs] [ 886.489542] [<ffffffffa0533953>] btrfs_commit_transaction+0x8f5/0x96e [btrfs] [ 886.489542] [<ffffffff81085096>] ? signal_pending_state+0x31/0x31 [ 886.489542] [<ffffffffa0521191>] btrfs_alloc_data_chunk_ondemand+0x1d7/0x288 [btrfs] [ 886.489542] [<ffffffffa0521282>] btrfs_check_data_free_space+0x40/0x59 [btrfs] [ 886.489542] [<ffffffffa05228f5>] btrfs_delalloc_reserve_space+0x1e/0x4e [btrfs] [ 886.489542] [<ffffffffa053620a>] btrfs_direct_IO+0x10c/0x27e [btrfs] [ 886.489542] [<ffffffff8111d9a1>] generic_file_direct_write+0xb3/0x128 [ 886.489542] [<ffffffffa05463c3>] btrfs_file_write_iter+0x229/0x408 [btrfs] [ 886.489542] [<ffffffff8108ae38>] ? __lock_is_held+0x38/0x50 [ 886.489542] [<ffffffff8117279e>] __vfs_write+0x7c/0xa5 [ 886.489542] [<ffffffff81172cda>] vfs_write+0xa0/0xe4 [ 886.489542] [<ffffffff811734cc>] SyS_write+0x50/0x7e [ 886.489542] [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f [ 1081.852335] INFO: task fio:8244 blocked for more than 120 seconds. [ 1081.854348] Not tainted 4.4.0-rc6-btrfs-next-18+ #1 [ 1081.857560] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1081.863227] fio D ffff880213f9bb28 0 8244 8240 0x00000000 [ 1081.868719] ffff880213f9bb28 00ffffff810fc6b0 ffffffff0000000a ffff88023ed55240 [ 1081.872499] ffff880206b5d400 ffff880213f9c000 ffff88020a4d5318 ffff880206b5d400 [ 1081.876834] ffffffff00000001 ffff880206b5d400 ffff880213f9bb40 ffffffff81482ba4 [ 1081.880782] Call Trace: [ 1081.881793] [<ffffffff81482ba4>] schedule+0x7f/0x97 [ 1081.883340] [<ffffffff81485eb5>] rwsem_down_write_failed+0x2d5/0x325 [ 1081.895525] [<ffffffff8108d48d>] ? trace_hardirqs_on_caller+0x16/0x1ab [ 1081.897419] [<ffffffff81269723>] call_rwsem_down_write_failed+0x13/0x20 [ 1081.899251] [<ffffffff81269723>] ? call_rwsem_down_write_failed+0x13/0x20 [ 1081.901063] [<ffffffff81089fae>] ? __down_write_nested.isra.0+0x1f/0x21 [ 1081.902365] [<ffffffff814855bd>] down_write+0x43/0x57 [ 1081.903846] [<ffffffffa05211b0>] ? btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs] [ 1081.906078] [<ffffffffa05211b0>] btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs] [ 1081.908846] [<ffffffff8108d461>] ? mark_held_locks+0x56/0x6c [ 1081.910409] [<ffffffffa0521282>] btrfs_check_data_free_space+0x40/0x59 [btrfs] [ 1081.912482] [<ffffffffa05228f5>] btrfs_delalloc_reserve_space+0x1e/0x4e [btrfs] [ 1081.914597] [<ffffffffa053620a>] btrfs_direct_IO+0x10c/0x27e [btrfs] [ 1081.919037] [<ffffffff8111d9a1>] generic_file_direct_write+0xb3/0x128 [ 1081.920754] [<ffffffffa05463c3>] btrfs_file_write_iter+0x229/0x408 [btrfs] [ 1081.922496] [<ffffffff8108ae38>] ? __lock_is_held+0x38/0x50 [ 1081.923922] [<ffffffff8117279e>] __vfs_write+0x7c/0xa5 [ 1081.925275] [<ffffffff81172cda>] vfs_write+0xa0/0xe4 [ 1081.926584] [<ffffffff811734cc>] SyS_write+0x50/0x7e [ 1081.927968] [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f [ 1081.985293] INFO: lockdep is turned off. [ 1081.986132] INFO: task fio:8249 blocked for more than 120 seconds. [ 1081.987434] Not tainted 4.4.0-rc6-btrfs-next-18+ #1 [ 1081.988534] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1081.990147] fio D ffff880218febbb8 0 8249 8240 0x00000000 [ 1081.991626] ffff880218febbb8 00ffffff81486b8e ffff88020000000b ffff88023ed75240 [ 1081.993258] ffff8802120a9a00 ffff880218fec000 ffff88020a4d5318 ffff8802120a9a00 [ 1081.994850] ffffffff00000001 ffff8802120a9a00 ffff880218febbd0 ffffffff81482ba4 [ 1081.996485] Call Trace: [ 1081.997037] [<ffffffff81482ba4>] schedule+0x7f/0x97 [ 1081.998017] [<ffffffff81485eb5>] rwsem_down_write_failed+0x2d5/0x325 [ 1081.999241] [<ffffffff810852a5>] ? finish_wait+0x6d/0x76 [ 1082.000306] [<ffffffff81269723>] call_rwsem_down_write_failed+0x13/0x20 [ 1082.001533] [<ffffffff81269723>] ? call_rwsem_down_write_failed+0x13/0x20 [ 1082.002776] [<ffffffff81089fae>] ? __down_write_nested.isra.0+0x1f/0x21 [ 1082.003995] [<ffffffff814855bd>] down_write+0x43/0x57 [ 1082.005000] [<ffffffffa05211b0>] ? btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs] [ 1082.007403] [<ffffffffa05211b0>] btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs] [ 1082.008988] [<ffffffffa0545064>] btrfs_fallocate+0x7c1/0xc2f [btrfs] [ 1082.010193] [<ffffffff8108a1ba>] ? percpu_down_read+0x4e/0x77 [ 1082.011280] [<ffffffff81174c4c>] ? __sb_start_write+0x5f/0xb0 [ 1082.012265] [<ffffffff81174c4c>] ? __sb_start_write+0x5f/0xb0 [ 1082.013021] [<ffffffff811712e4>] vfs_fallocate+0x170/0x1ff [ 1082.013738] [<ffffffff81181ebb>] ioctl_preallocate+0x89/0x9b [ 1082.014778] [<ffffffff811822d7>] do_vfs_ioctl+0x40a/0x4ea [ 1082.015778] [<ffffffff81176ea7>] ? SYSC_newfstat+0x25/0x2e [ 1082.016806] [<ffffffff8118b4de>] ? __fget_light+0x4d/0x71 [ 1082.017789] [<ffffffff8118240e>] SyS_ioctl+0x57/0x79 [ 1082.018706] [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f This happens because we can recursively acquire the semaphore fs_info->delayed_iput_sem when attempting to allocate space to satisfy a file write request as shown in the first trace above - when committing a transaction we acquire (down_read) the semaphore before running the delayed iputs, and when running a delayed iput() we can end up calling an inode's eviction handler, which in turn commits another transaction and attempts to acquire (down_read) again the semaphore to run more delayed iput operations. This results in a deadlock because if a task acquires multiple times a semaphore it should invoke down_read_nested() with a different lockdep class for each level of recursion. Fix this by simplifying the implementation and use a mutex instead that is acquired by the cleaner kthread before it runs the delayed iputs instead of always acquiring a semaphore before delayed references are run from anywhere. Fixes: d7c151717a1e (btrfs: Fix NO_SPACE bug caused by delayed-iput) Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03btrfs: initialize the seq counter in struct btrfs_deviceSebastian Andrzej Siewior
commit 546bed631203344611f42b2af1d224d2eedb4e6b upstream. I managed to trigger this: | INFO: trying to register non-static key. | the code is fine but needs lockdep annotation. | turning off the locking correctness validator. | CPU: 1 PID: 781 Comm: systemd-gpt-aut Not tainted 4.4.0-rt2+ #14 | Hardware name: ARM-Versatile Express | [<80307cec>] (dump_stack) | [<80070e98>] (__lock_acquire) | [<8007184c>] (lock_acquire) | [<80287800>] (btrfs_ioctl) | [<8012a8d4>] (do_vfs_ioctl) | [<8012ac14>] (SyS_ioctl) so I think that btrfs_device_data_ordered_init() is not invoked behind a macro somewhere. Fixes: 7cc8e58d53cd ("Btrfs: fix unprotected device's variants on 32bits machine") Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.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>
2016-03-03Btrfs: Initialize btrfs_root->highest_objectid when loading tree root and ↵Chandan Rajendra
subvolume roots commit f32e48e925964c4f8ab917850788a87e1cef3bad upstream. The following call trace is seen when btrfs/031 test is executed in a loop, [ 158.661848] ------------[ cut here ]------------ [ 158.662634] WARNING: CPU: 2 PID: 890 at /home/chandan/repos/linux/fs/btrfs/ioctl.c:558 create_subvol+0x3d1/0x6ea() [ 158.664102] BTRFS: Transaction aborted (error -2) [ 158.664774] Modules linked in: [ 158.665266] CPU: 2 PID: 890 Comm: btrfs Not tainted 4.4.0-rc6-g511711a #2 [ 158.666251] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 [ 158.667392] ffffffff81c0a6b0 ffff8806c7c4f8e8 ffffffff81431fc8 ffff8806c7c4f930 [ 158.668515] ffff8806c7c4f920 ffffffff81051aa1 ffff880c85aff000 ffff8800bb44d000 [ 158.669647] ffff8808863b5c98 0000000000000000 00000000fffffffe ffff8806c7c4f980 [ 158.670769] Call Trace: [ 158.671153] [<ffffffff81431fc8>] dump_stack+0x44/0x5c [ 158.671884] [<ffffffff81051aa1>] warn_slowpath_common+0x81/0xc0 [ 158.672769] [<ffffffff81051b27>] warn_slowpath_fmt+0x47/0x50 [ 158.673620] [<ffffffff813bc98d>] create_subvol+0x3d1/0x6ea [ 158.674440] [<ffffffff813777c9>] btrfs_mksubvol.isra.30+0x369/0x520 [ 158.675376] [<ffffffff8108a4aa>] ? percpu_down_read+0x1a/0x50 [ 158.676235] [<ffffffff81377a81>] btrfs_ioctl_snap_create_transid+0x101/0x180 [ 158.677268] [<ffffffff81377b52>] btrfs_ioctl_snap_create+0x52/0x70 [ 158.678183] [<ffffffff8137afb4>] btrfs_ioctl+0x474/0x2f90 [ 158.678975] [<ffffffff81144b8e>] ? vma_merge+0xee/0x300 [ 158.679751] [<ffffffff8115be31>] ? alloc_pages_vma+0x91/0x170 [ 158.680599] [<ffffffff81123f62>] ? lru_cache_add_active_or_unevictable+0x22/0x70 [ 158.681686] [<ffffffff813d99cf>] ? selinux_file_ioctl+0xff/0x1d0 [ 158.682581] [<ffffffff8117b791>] do_vfs_ioctl+0x2c1/0x490 [ 158.683399] [<ffffffff813d3cde>] ? security_file_ioctl+0x3e/0x60 [ 158.684297] [<ffffffff8117b9d4>] SyS_ioctl+0x74/0x80 [ 158.685051] [<ffffffff819b2bd7>] entry_SYSCALL_64_fastpath+0x12/0x6a [ 158.685958] ---[ end trace 4b63312de5a2cb76 ]--- [ 158.686647] BTRFS: error (device loop0) in create_subvol:558: errno=-2 No such entry [ 158.709508] BTRFS info (device loop0): forced readonly [ 158.737113] BTRFS info (device loop0): disk space caching is enabled [ 158.738096] BTRFS error (device loop0): Remounting read-write after error is not allowed [ 158.851303] BTRFS error (device loop0): cleaner transaction attach returned -30 This occurs because, Mount filesystem Create subvol with ID 257 Unmount filesystem Mount filesystem Delete subvol with ID 257 btrfs_drop_snapshot() Add root corresponding to subvol 257 into btrfs_transaction->dropped_roots list Create new subvol (i.e. create_subvol()) 257 is returned as the next free objectid btrfs_read_fs_root_no_name() Finds the btrfs_root instance corresponding to the old subvol with ID 257 in btrfs_fs_info->fs_roots_radix. Returns error since btrfs_root_item->refs has the value of 0. To fix the issue the commit initializes tree root's and subvolume root's highest_objectid when loading the roots from disk. Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03Btrfs: fix transaction handle leak on failure to create hard linkFilipe Manana
commit 271dba4521aed0c37c063548f876b49f5cd64b2e upstream. If we failed to create a hard link we were not always releasing the the transaction handle we got before, resulting in a memory leak and preventing any other tasks from being able to commit the current transaction. Fix this by always releasing our transaction handle. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03Btrfs: fix number of transaction units required to create symlinkFilipe Manana
commit 9269d12b2d57d9e3d13036bb750762d1110d425c upstream. We weren't accounting for the insertion of an inline extent item for the symlink inode nor that we need to update the parent inode item (through the call to btrfs_add_nondir()). So fix this by including two more transaction units. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03Btrfs: send, don't BUG_ON() when an empty symlink is foundFilipe Manana
commit a879719b8c90e15c9e7fa7266d5e3c0ca962f9df upstream. When a symlink is successfully created it always has an inline extent containing the source path. However if an error happens when creating the symlink, we can leave in the subvolume's tree a symlink inode without any such inline extent item - this happens if after btrfs_symlink() calls btrfs_end_transaction() and before it calls the inode eviction handler (through the final iput() call), the transaction gets committed and a crash happens before the eviction handler gets called, or if a snapshot of the subvolume is made before the eviction handler gets called. Sadly we can't just avoid this by making btrfs_symlink() call btrfs_end_transaction() after it calls the eviction handler, because the later can commit the current transaction before it removes any items from the subvolume tree (if it encounters ENOSPC errors while reserving space for removing all the items). So make send fail more gracefully, with an -EIO error, and print a message to dmesg/syslog informing that there's an empty symlink inode, so that the user can delete the empty symlink or do something else about it. Reported-by: Stephen R. van den Berg <srb@cuci.nl> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03btrfs: statfs: report zero available if metadata are exhaustedDavid Sterba
commit ca8a51b3a979d57b082b14eda38602b7f52d81d1 upstream. There is one ENOSPC case that's very confusing. There's Available greater than zero but no file operation succeds (besides removing files). This happens when the metadata are exhausted and there's no possibility to allocate another chunk. In this scenario it's normal that there's still some space in the data chunk and the calculation in df reflects that in the Avail value. To at least give some clue about the ENOSPC situation, let statfs report zero value in Avail, even if there's still data space available. Current: /dev/sdb1 4.0G 3.3G 719M 83% /mnt/test New: /dev/sdb1 4.0G 3.3G 0 100% /mnt/test We calculate the remaining metadata space minus global reserve. If this is (supposedly) smaller than zero, there's no space. But this does not hold in practice, the exhausted state happens where's still some positive delta. So we apply some guesswork and compare the delta to a 4M threshold. (Practically observed delta was 2M.) We probably cannot calculate the exact threshold value because this depends on the internal reservations requested by various operations, so some operations that consume a few metadata will succeed even if the Avail is zero. But this is better than the other way around. Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03Btrfs: igrab inode in writepageJosef Bacik
commit be7bd730841e69fe8f70120098596f648cd1f3ff upstream. We hit this panic on a few of our boxes this week where we have an ordered_extent with an NULL inode. We do an igrab() of the inode in writepages, but weren't doing it in writepage which can be called directly from the VM on dirty pages. If the inode has been unlinked then we could have I_FREEING set which means igrab() would return NULL and we get this panic. Fix this by trying to igrab in btrfs_writepage, and if it returns NULL then just redirty the page and return AOP_WRITEPAGE_ACTIVATE; so the VM knows it wasn't successful. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03Btrfs: add missing brelse when superblock checksum failsAnand Jain
commit b2acdddfad13c38a1e8b927d83c3cf321f63601a upstream. Looks like oversight, call brelse() when checksum fails. Further down the code, in the non error path, we do call brelse() and so we don't see brelse() in the goto error paths. Signed-off-by: Anand Jain <anand.jain@oracle.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>
2016-02-25Btrfs: fix direct IO requests not reporting IO error to user spaceFilipe Manana
commit 1636d1d77ef4e01e57f706a4cae3371463896136 upstream. If a bio for a direct IO request fails, we were not setting the error in the parent bio (the main DIO bio), making us not return the error to user space in btrfs_direct_IO(), that is, it made __blockdev_direct_IO() return the number of bytes issued for IO and not the error a bio created and submitted by btrfs_submit_direct() got from the block layer. This essentially happens because when we call: dio_end_io(dio_bio, bio->bi_error); It does not set dio_bio->bi_error to the value of the second argument. So just add this missing assignment in endio callbacks, just as we do in the error path at btrfs_submit_direct() when we fail to clone the dio bio or allocate its private object. This follows the convention of what is done with other similar APIs such as bio_endio() where the caller is responsible for setting the bi_error field in the bio it passes as an argument to bio_endio(). This was detected by the new generic test cases in xfstests: 271, 272, 276 and 278. Which essentially setup a dm error target, then load the error table, do a direct IO write and unload the error table. They expect the write to fail with -EIO, which was not getting reported when testing against btrfs. Fixes: 4246a0b63bd8 ("block: add a bi_error field to struct bio") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25Btrfs: fix hang on extent buffer lock caused by the inode_paths ioctlFilipe Manana
commit 0c0fe3b0fa45082cd752553fdb3a4b42503a118e upstream. While doing some tests I ran into an hang on an extent buffer's rwlock that produced the following trace: [39389.800012] NMI watchdog: BUG: soft lockup - CPU#15 stuck for 22s! [fdm-stress:32166] [39389.800016] NMI watchdog: BUG: soft lockup - CPU#14 stuck for 22s! [fdm-stress:32165] [39389.800016] Modules linked in: btrfs dm_mod ppdev xor sha256_generic hmac raid6_pq drbg ansi_cprng aesni_intel i2c_piix4 acpi_cpufreq aes_x86_64 ablk_helper tpm_tis parport_pc i2c_core sg cryptd evdev psmouse lrw tpm parport gf128mul serio_raw pcspkr glue_helper processor button loop autofs4 ext4 crc16 mbcache jbd2 sd_mod sr_mod cdrom ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel scsi_mod e1000 virtio floppy [last unloaded: btrfs] [39389.800016] irq event stamp: 0 [39389.800016] hardirqs last enabled at (0): [< (null)>] (null) [39389.800016] hardirqs last disabled at (0): [<ffffffff8104e58d>] copy_process+0x638/0x1a35 [39389.800016] softirqs last enabled at (0): [<ffffffff8104e58d>] copy_process+0x638/0x1a35 [39389.800016] softirqs last disabled at (0): [< (null)>] (null) [39389.800016] CPU: 14 PID: 32165 Comm: fdm-stress Not tainted 4.4.0-rc6-btrfs-next-18+ #1 [39389.800016] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [39389.800016] task: ffff880175b1ca40 ti: ffff8800a185c000 task.ti: ffff8800a185c000 [39389.800016] RIP: 0010:[<ffffffff810902af>] [<ffffffff810902af>] queued_spin_lock_slowpath+0x57/0x158 [39389.800016] RSP: 0018:ffff8800a185fb80 EFLAGS: 00000202 [39389.800016] RAX: 0000000000000101 RBX: ffff8801710c4e9c RCX: 0000000000000101 [39389.800016] RDX: 0000000000000100 RSI: 0000000000000001 RDI: 0000000000000001 [39389.800016] RBP: ffff8800a185fb98 R08: 0000000000000001 R09: 0000000000000000 [39389.800016] R10: ffff8800a185fb68 R11: 6db6db6db6db6db7 R12: ffff8801710c4e98 [39389.800016] R13: ffff880175b1ca40 R14: ffff8800a185fc10 R15: ffff880175b1ca40 [39389.800016] FS: 00007f6d37fff700(0000) GS:ffff8802be9c0000(0000) knlGS:0000000000000000 [39389.800016] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [39389.800016] CR2: 00007f6d300019b8 CR3: 0000000037c93000 CR4: 00000000001406e0 [39389.800016] Stack: [39389.800016] ffff8801710c4e98 ffff8801710c4e98 ffff880175b1ca40 ffff8800a185fbb0 [39389.800016] ffffffff81091e11 ffff8801710c4e98 ffff8800a185fbc8 ffffffff81091895 [39389.800016] ffff8801710c4e98 ffff8800a185fbe8 ffffffff81486c5c ffffffffa067288c [39389.800016] Call Trace: [39389.800016] [<ffffffff81091e11>] queued_read_lock_slowpath+0x46/0x60 [39389.800016] [<ffffffff81091895>] do_raw_read_lock+0x3e/0x41 [39389.800016] [<ffffffff81486c5c>] _raw_read_lock+0x3d/0x44 [39389.800016] [<ffffffffa067288c>] ? btrfs_tree_read_lock+0x54/0x125 [btrfs] [39389.800016] [<ffffffffa067288c>] btrfs_tree_read_lock+0x54/0x125 [btrfs] [39389.800016] [<ffffffffa0622ced>] ? btrfs_find_item+0xa7/0xd2 [btrfs] [39389.800016] [<ffffffffa069363f>] btrfs_ref_to_path+0xd6/0x174 [btrfs] [39389.800016] [<ffffffffa0693730>] inode_to_path+0x53/0xa2 [btrfs] [39389.800016] [<ffffffffa0693e2e>] paths_from_inode+0x117/0x2ec [btrfs] [39389.800016] [<ffffffffa0670cff>] btrfs_ioctl+0xd5b/0x2793 [btrfs] [39389.800016] [<ffffffff8108a8b0>] ? arch_local_irq_save+0x9/0xc [39389.800016] [<ffffffff81276727>] ? __this_cpu_preempt_check+0x13/0x15 [39389.800016] [<ffffffff8108a8b0>] ? arch_local_irq_save+0x9/0xc [39389.800016] [<ffffffff8118b3d4>] ? rcu_read_unlock+0x3e/0x5d [39389.800016] [<ffffffff811822f8>] do_vfs_ioctl+0x42b/0x4ea [39389.800016] [<ffffffff8118b4f3>] ? __fget_light+0x62/0x71 [39389.800016] [<ffffffff8118240e>] SyS_ioctl+0x57/0x79 [39389.800016] [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f [39389.800016] Code: b9 01 01 00 00 f7 c6 00 ff ff ff 75 32 83 fe 01 89 ca 89 f0 0f 45 d7 f0 0f b1 13 39 f0 74 04 89 c6 eb e2 ff ca 0f 84 fa 00 00 00 <8b> 03 84 c0 74 04 f3 90 eb f6 66 c7 03 01 00 e9 e6 00 00 00 e8 [39389.800012] Modules linked in: btrfs dm_mod ppdev xor sha256_generic hmac raid6_pq drbg ansi_cprng aesni_intel i2c_piix4 acpi_cpufreq aes_x86_64 ablk_helper tpm_tis parport_pc i2c_core sg cryptd evdev psmouse lrw tpm parport gf128mul serio_raw pcspkr glue_helper processor button loop autofs4 ext4 crc16 mbcache jbd2 sd_mod sr_mod cdrom ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel scsi_mod e1000 virtio floppy [last unloaded: btrfs] [39389.800012] irq event stamp: 0 [39389.800012] hardirqs last enabled at (0): [< (null)>] (null) [39389.800012] hardirqs last disabled at (0): [<ffffffff8104e58d>] copy_process+0x638/0x1a35 [39389.800012] softirqs last enabled at (0): [<ffffffff8104e58d>] copy_process+0x638/0x1a35 [39389.800012] softirqs last disabled at (0): [< (null)>] (null) [39389.800012] CPU: 15 PID: 32166 Comm: fdm-stress Tainted: G L 4.4.0-rc6-btrfs-next-18+ #1 [39389.800012] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [39389.800012] task: ffff880179294380 ti: ffff880034a60000 task.ti: ffff880034a60000 [39389.800012] RIP: 0010:[<ffffffff81091e8d>] [<ffffffff81091e8d>] queued_write_lock_slowpath+0x62/0x72 [39389.800012] RSP: 0018:ffff880034a639f0 EFLAGS: 00000206 [39389.800012] RAX: 0000000000000101 RBX: ffff8801710c4e98 RCX: 0000000000000000 [39389.800012] RDX: 00000000000000ff RSI: 0000000000000000 RDI: ffff8801710c4e9c [39389.800012] RBP: ffff880034a639f8 R08: 0000000000000001 R09: 0000000000000000 [39389.800012] R10: ffff880034a639b0 R11: 0000000000001000 R12: ffff8801710c4e98 [39389.800012] R13: 0000000000000001 R14: ffff880172cbc000 R15: ffff8801710c4e00 [39389.800012] FS: 00007f6d377fe700(0000) GS:ffff8802be9e0000(0000) knlGS:0000000000000000 [39389.800012] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [39389.800012] CR2: 00007f6d3d3c1000 CR3: 0000000037c93000 CR4: 00000000001406e0 [39389.800012] Stack: [39389.800012] ffff8801710c4e98 ffff880034a63a10 ffffffff81091963 ffff8801710c4e98 [39389.800012] ffff880034a63a30 ffffffff81486f1b ffffffffa0672cb3 ffff8801710c4e00 [39389.800012] ffff880034a63a78 ffffffffa0672cb3 ffff8801710c4e00 ffff880034a63a58 [39389.800012] Call Trace: [39389.800012] [<ffffffff81091963>] do_raw_write_lock+0x72/0x8c [39389.800012] [<ffffffff81486f1b>] _raw_write_lock+0x3a/0x41 [39389.800012] [<ffffffffa0672cb3>] ? btrfs_tree_lock+0x119/0x251 [btrfs] [39389.800012] [<ffffffffa0672cb3>] btrfs_tree_lock+0x119/0x251 [btrfs] [39389.800012] [<ffffffffa061aeba>] ? rcu_read_unlock+0x5b/0x5d [btrfs] [39389.800012] [<ffffffffa061ce13>] ? btrfs_root_node+0xda/0xe6 [btrfs] [39389.800012] [<ffffffffa061ce83>] btrfs_lock_root_node+0x22/0x42 [btrfs] [39389.800012] [<ffffffffa062046b>] btrfs_search_slot+0x1b8/0x758 [btrfs] [39389.800012] [<ffffffff810fc6b0>] ? time_hardirqs_on+0x15/0x28 [39389.800012] [<ffffffffa06365db>] btrfs_lookup_inode+0x31/0x95 [btrfs] [39389.800012] [<ffffffff8108d62f>] ? trace_hardirqs_on+0xd/0xf [39389.800012] [<ffffffff8148482b>] ? mutex_lock_nested+0x397/0x3bc [39389.800012] [<ffffffffa068821b>] __btrfs_update_delayed_inode+0x59/0x1c0 [btrfs] [39389.800012] [<ffffffffa068858e>] __btrfs_commit_inode_delayed_items+0x194/0x5aa [btrfs] [39389.800012] [<ffffffff81486ab7>] ? _raw_spin_unlock+0x31/0x44 [39389.800012] [<ffffffffa0688a48>] __btrfs_run_delayed_items+0xa4/0x15c [btrfs] [39389.800012] [<ffffffffa0688d62>] btrfs_run_delayed_items+0x11/0x13 [btrfs] [39389.800012] [<ffffffffa064048e>] btrfs_commit_transaction+0x234/0x96e [btrfs] [39389.800012] [<ffffffffa0618d10>] btrfs_sync_fs+0x145/0x1ad [btrfs] [39389.800012] [<ffffffffa0671176>] btrfs_ioctl+0x11d2/0x2793 [btrfs] [39389.800012] [<ffffffff8108a8b0>] ? arch_local_irq_save+0x9/0xc [39389.800012] [<ffffffff81140261>] ? __might_fault+0x4c/0xa7 [39389.800012] [<ffffffff81140261>] ? __might_fault+0x4c/0xa7 [39389.800012] [<ffffffff8108a8b0>] ? arch_local_irq_save+0x9/0xc [39389.800012] [<ffffffff8118b3d4>] ? rcu_read_unlock+0x3e/0x5d [39389.800012] [<ffffffff811822f8>] do_vfs_ioctl+0x42b/0x4ea [39389.800012] [<ffffffff8118b4f3>] ? __fget_light+0x62/0x71 [39389.800012] [<ffffffff8118240e>] SyS_ioctl+0x57/0x79 [39389.800012] [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f [39389.800012] Code: f0 0f b1 13 85 c0 75 ef eb 2a f3 90 8a 03 84 c0 75 f8 f0 0f b0 13 84 c0 75 f0 ba ff 00 00 00 eb 0a f0 0f b1 13 ff c8 74 0b f3 90 <8b> 03 83 f8 01 75 f7 eb ed c6 43 04 00 5b 5d c3 0f 1f 44 00 00 This happens because in the code path executed by the inode_paths ioctl we end up nesting two calls to read lock a leaf's rwlock when after the first call to read_lock() and before the second call to read_lock(), another task (running the delayed items as part of a transaction commit) has already called write_lock() against the leaf's rwlock. This situation is illustrated by the following diagram: Task A Task B btrfs_ref_to_path() btrfs_commit_transaction() read_lock(&eb->lock); btrfs_run_delayed_items() __btrfs_commit_inode_delayed_items() __btrfs_update_delayed_inode() btrfs_lookup_inode() write_lock(&eb->lock); --> task waits for lock read_lock(&eb->lock); --> makes this task hang forever (and task B too of course) So fix this by avoiding doing the nested read lock, which is easily avoidable. This issue does not happen if task B calls write_lock() after task A does the second call to read_lock(), however there does not seem to exist anything in the documentation that mentions what is the expected behaviour for recursive locking of rwlocks (leaving the idea that doing so is not a good usage of rwlocks). Also, as a side effect necessary for this fix, make sure we do not needlessly read lock extent buffers when the input path has skip_locking set (used when called from send). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25Btrfs: fix page reading in extent_same ioctl leading to csum errorsFilipe Manana
commit 313140023026ae542ad76e7e268c56a1eaa2c28e upstream. In the extent_same ioctl, we were grabbing the pages (locked) and attempting to read them without bothering about any concurrent IO against them. That is, we were not checking for any ongoing ordered extents nor waiting for them to complete, which leads to a race where the extent_same() code gets a checksum verification error when it reads the pages, producing a message like the following in dmesg and making the operation fail to user space with -ENOMEM: [18990.161265] BTRFS warning (device sdc): csum failed ino 259 off 495616 csum 685204116 expected csum 1515870868 Fix this by using btrfs_readpage() for reading the pages instead of extent_read_full_page_nolock(), which waits for any concurrent ordered extents to complete and locks the io range. Also do better error handling and don't treat all failures as -ENOMEM, as that's clearly misleasing, becoming identical to the checks and operation of prepare_uptodate_page(). The use of extent_read_full_page_nolock() was required before commit f441460202cb ("btrfs: fix deadlock with extent-same and readpage"), as we had the range locked in an inode's io tree before attempting to read the pages. Fixes: f441460202cb ("btrfs: fix deadlock with extent-same and readpage") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25Btrfs: fix invalid page accesses in extent_same (dedup) ioctlFilipe Manana
commit e0bd70c67bf996b360f706b6c643000f2e384681 upstream. In the extent_same ioctl we are getting the pages for the source and target ranges and unlocking them immediately after, which is incorrect because later we attempt to map them (with kmap_atomic) and access their contents at btrfs_cmp_data(). When we do such access the pages might have been relocated or removed from memory, which leads to an invalid memory access. This issue is detected on a kernel with CONFIG_DEBUG_PAGEALLOC=y which produces a trace like the following: 186736.677437] general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [186736.680382] Modules linked in: btrfs dm_flakey dm_mod ppdev xor raid6_pq sha256_generic hmac drbg ansi_cprng acpi_cpufreq evdev sg aesni_intel aes_x86_64 parport_pc ablk_helper tpm_tis psmouse parport i2c_piix4 tpm cryptd i2c_core lrw processor button serio_raw pcspkr gf128mul glue_helper loop autofs4 ext4 crc16 mbcache jbd2 sd_mod sr_mod cdrom ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel scsi_mod e1000 virtio floppy [last unloaded: btrfs] [186736.681319] CPU: 13 PID: 10222 Comm: duperemove Tainted: G W 4.4.0-rc6-btrfs-next-18+ #1 [186736.681319] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [186736.681319] task: ffff880132600400 ti: ffff880362284000 task.ti: ffff880362284000 [186736.681319] RIP: 0010:[<ffffffff81264d00>] [<ffffffff81264d00>] memcmp+0xb/0x22 [186736.681319] RSP: 0018:ffff880362287d70 EFLAGS: 00010287 [186736.681319] RAX: 000002c002468acf RBX: 0000000012345678 RCX: 0000000000000000 [186736.681319] RDX: 0000000000001000 RSI: 0005d129c5cf9000 RDI: 0005d129c5cf9000 [186736.681319] RBP: ffff880362287d70 R08: 0000000000000000 R09: 0000000000001000 [186736.681319] R10: ffff880000000000 R11: 0000000000000476 R12: 0000000000001000 [186736.681319] R13: ffff8802f91d4c88 R14: ffff8801f2a77830 R15: ffff880352e83e40 [186736.681319] FS: 00007f27b37fe700(0000) GS:ffff88043dda0000(0000) knlGS:0000000000000000 [186736.681319] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [186736.681319] CR2: 00007f27a406a000 CR3: 0000000217421000 CR4: 00000000001406e0 [186736.681319] Stack: [186736.681319] ffff880362287ea0 ffffffffa048d0bd 000000000009f000 0000000000001000 [186736.681319] 0100000000000000 ffff8801f2a77850 ffff8802f91d49b0 ffff880132600400 [186736.681319] 00000000000004f8 ffff8801c1efbe41 0000000000000000 0000000000000038 [186736.681319] Call Trace: [186736.681319] [<ffffffffa048d0bd>] btrfs_ioctl+0x24cb/0x2731 [btrfs] [186736.681319] [<ffffffff8108a8b0>] ? arch_local_irq_save+0x9/0xc [186736.681319] [<ffffffff8118b3d4>] ? rcu_read_unlock+0x3e/0x5d [186736.681319] [<ffffffff811822f8>] do_vfs_ioctl+0x42b/0x4ea [186736.681319] [<ffffffff8118b4f3>] ? __fget_light+0x62/0x71 [186736.681319] [<ffffffff8118240e>] SyS_ioctl+0x57/0x79 [186736.681319] [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f [186736.681319] Code: 0a 3c 6e 74 0d 3c 79 74 04 3c 59 75 0c c6 06 01 eb 03 c6 06 00 31 c0 eb 05 b8 ea ff ff ff 5d c3 55 31 c9 48 89 e5 48 39 d1 74 13 <0f> b6 04 0f 44 0f b6 04 0e 48 ff c1 44 29 c0 74 ea eb 02 31 c0 (gdb) list *(btrfs_ioctl+0x24cb) 0x5e0e1 is in btrfs_ioctl (fs/btrfs/ioctl.c:2972). 2967 dst_addr = kmap_atomic(dst_page); 2968 2969 flush_dcache_page(src_page); 2970 flush_dcache_page(dst_page); 2971 2972 if (memcmp(addr, dst_addr, cmp_len)) 2973 ret = BTRFS_SAME_DATA_DIFFERS; 2974 2975 kunmap_atomic(addr); 2976 kunmap_atomic(dst_addr); So fix this by making sure we keep the pages locked and respect the same locking order as everywhere else: get and lock the pages first and then lock the range in the inode's io tree (like for example at __btrfs_buffered_write() and extent_readpages()). If an ordered extent is found after locking the range in the io tree, unlock the range, unlock the pages, wait for the ordered extent to complete and repeat the entire locking process until no overlapping ordered extents are found. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25btrfs: properly set the termination value of ctx->pos in readdirDavid Sterba
commit bc4ef7592f657ae81b017207a1098817126ad4cb upstream. The value of ctx->pos in the last readdir call is supposed to be set to INT_MAX due to 32bit compatibility, unless 'pos' is intentially set to a larger value, then it's LLONG_MAX. There's a report from PaX SIZE_OVERFLOW plugin that "ctx->pos++" overflows (https://forums.grsecurity.net/viewtopic.php?f=1&t=4284), on a 64bit arch, where the value is 0x7fffffffffffffff ie. LLONG_MAX before the increment. We can get to that situation like that: * emit all regular readdir entries * still in the same call to readdir, bump the last pos to INT_MAX * next call to readdir will not emit any entries, but will reach the bump code again, finds pos to be INT_MAX and sets it to LLONG_MAX Normally this is not a problem, but if we call readdir again, we'll find 'pos' set to LLONG_MAX and the unconditional increment will overflow. The report from Victor at (http://thread.gmane.org/gmane.comp.file-systems.btrfs/49500) with debugging print shows that pattern: Overflow: e Overflow: 7fffffff Overflow: 7fffffffffffffff PAX: size overflow detected in function btrfs_real_readdir fs/btrfs/inode.c:5760 cicus.935_282 max, count: 9, decl: pos; num: 0; context: dir_context; CPU: 0 PID: 2630 Comm: polkitd Not tainted 4.2.3-grsec #1 Hardware name: Gigabyte Technology Co., Ltd. H81ND2H/H81ND2H, BIOS F3 08/11/2015 ffffffff81901608 0000000000000000 ffffffff819015e6 ffffc90004973d48 ffffffff81742f0f 0000000000000007 ffffffff81901608 ffffc90004973d78 ffffffff811cb706 0000000000000000 ffff8800d47359e0 ffffc90004973ed8 Call Trace: [<ffffffff81742f0f>] dump_stack+0x4c/0x7f [<ffffffff811cb706>] report_size_overflow+0x36/0x40 [<ffffffff812ef0bc>] btrfs_real_readdir+0x69c/0x6d0 [<ffffffff811dafc8>] iterate_dir+0xa8/0x150 [<ffffffff811e6d8d>] ? __fget_light+0x2d/0x70 [<ffffffff811dba3a>] SyS_getdents+0xba/0x1c0 Overflow: 1a [<ffffffff811db070>] ? iterate_dir+0x150/0x150 [<ffffffff81749b69>] entry_SYSCALL_64_fastpath+0x12/0x83 The jump from 7fffffff to 7fffffffffffffff happens when new dir entries are not yet synced and are processed from the delayed list. Then the code could go to the bump section again even though it might not emit any new dir entries from the delayed list. The fix avoids entering the "bump" section again once we've finished emitting the entries, both for synced and delayed entries. References: https://forums.grsecurity.net/viewtopic.php?f=1&t=4284 Reported-by: Victor <services@swwu.com> Signed-off-by: David Sterba <dsterba@suse.com> Tested-by: Holger Hoffstätte <holger.hoffstaette@googlemail.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25Revert "btrfs: clear PF_NOFREEZE in cleaner_kthread()"David Sterba
commit 80ad623edd2d0ccb47d85357ee31c97e6c684e82 upstream. This reverts commit 696249132158014d594896df3a81390616069c5c. The cleaner thread can block freezing when there's a snapshot cleaning in progress and the other threads get suspended first. From the logs provided by Martin we're waiting for reading extent pages: kernel: PM: Syncing filesystems ... done. kernel: Freezing user space processes ... (elapsed 0.015 seconds) done. kernel: Freezing remaining freezable tasks ... kernel: Freezing of tasks failed after 20.003 seconds (1 tasks refusing to freeze, wq_busy=0): kernel: btrfs-cleaner D ffff88033dd13bc0 0 152 2 0x00000000 kernel: ffff88032ebc2e00 ffff88032e750000 ffff88032e74fa50 7fffffffffffffff kernel: ffffffff814a58df 0000000000000002 ffffea000934d580 ffffffff814a5451 kernel: 7fffffffffffffff ffffffff814a6e8f 0000000000000000 0000000000000020 kernel: Call Trace: kernel: [<ffffffff814a58df>] ? bit_wait+0x2c/0x2c kernel: [<ffffffff814a5451>] ? schedule+0x6f/0x7c kernel: [<ffffffff814a6e8f>] ? schedule_timeout+0x2f/0xd8 kernel: [<ffffffff81076f94>] ? timekeeping_get_ns+0xa/0x2e kernel: [<ffffffff81077603>] ? ktime_get+0x36/0x44 kernel: [<ffffffff814a4f6c>] ? io_schedule_timeout+0x94/0xf2 kernel: [<ffffffff814a4f6c>] ? io_schedule_timeout+0x94/0xf2 kernel: [<ffffffff814a590b>] ? bit_wait_io+0x2c/0x30 kernel: [<ffffffff814a5694>] ? __wait_on_bit+0x41/0x73 kernel: [<ffffffff8109eba8>] ? wait_on_page_bit+0x6d/0x72 kernel: [<ffffffff8105d718>] ? autoremove_wake_function+0x2a/0x2a kernel: [<ffffffff811a02d7>] ? read_extent_buffer_pages+0x1bd/0x203 kernel: [<ffffffff8117d9e9>] ? free_root_pointers+0x4c/0x4c kernel: [<ffffffff8117e831>] ? btree_read_extent_buffer_pages.constprop.57+0x5a/0xe9 kernel: [<ffffffff8117f4f3>] ? read_tree_block+0x2d/0x45 kernel: [<ffffffff8116782a>] ? read_block_for_search.isra.34+0x22a/0x26b kernel: [<ffffffff811656c3>] ? btrfs_set_path_blocking+0x1e/0x4a kernel: [<ffffffff8116919b>] ? btrfs_search_slot+0x648/0x736 kernel: [<ffffffff81170559>] ? btrfs_lookup_extent_info+0xb7/0x2c7 kernel: [<ffffffff81170ee5>] ? walk_down_proc+0x9c/0x1ae kernel: [<ffffffff81171c9d>] ? walk_down_tree+0x40/0xa4 kernel: [<ffffffff8117375f>] ? btrfs_drop_snapshot+0x2da/0x664 kernel: [<ffffffff8104ff21>] ? finish_task_switch+0x126/0x167 kernel: [<ffffffff811850f8>] ? btrfs_clean_one_deleted_snapshot+0xa6/0xb0 kernel: [<ffffffff8117eaba>] ? cleaner_kthread+0x13e/0x17b kernel: [<ffffffff8117e97c>] ? btrfs_item_end+0x33/0x33 kernel: [<ffffffff8104d256>] ? kthread+0x95/0x9d kernel: [<ffffffff8104d1c1>] ? kthread_parkme+0x16/0x16 kernel: [<ffffffff814a7b5f>] ? ret_from_fork+0x3f/0x70 kernel: [<ffffffff8104d1c1>] ? kthread_parkme+0x16/0x16 As this affects a released kernel (4.4) we need a minimal fix for stable kernels. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=108361 Reported-by: Martin Ziegler <ziegler@uni-freiburg.de> CC: Jiri Kosina <jkosina@suse.cz> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25Btrfs: fix fitrim discarding device area reserved for boot loader's useFilipe Manana
commit 8cdc7c5b00d945a3c823fc4277af304abb9cb43d upstream. As of the 4.3 kernel release, the fitrim ioctl can now discard any region of a disk that is not allocated to any chunk/block group, including the first megabyte which is used for our primary superblock and by the boot loader (grub for example). Fix this by not allowing to trim/discard any region in the device starting with an offset not greater than min(alloc_start_mount_option, 1Mb), just as it was not possible before 4.3. A reproducer test case for xfstests follows. seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { cd / rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter # real QA test starts here _need_to_be_root _supported_fs btrfs _supported_os Linux _require_scratch rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 # Write to the [0, 64Kb[ and [68Kb, 1Mb[ ranges of the device. These ranges are # reserved for a boot loader to use (GRUB for example) and btrfs should never # use them - neither for allocating metadata/data nor should trim/discard them. # The range [64Kb, 68Kb[ is used for the primary superblock of the filesystem. $XFS_IO_PROG -c "pwrite -S 0xfd 0 64K" $SCRATCH_DEV | _filter_xfs_io $XFS_IO_PROG -c "pwrite -S 0xfd 68K 956K" $SCRATCH_DEV | _filter_xfs_io # Now mount the filesystem and perform a fitrim against it. _scratch_mount _require_batched_discard $SCRATCH_MNT $FSTRIM_PROG $SCRATCH_MNT # Now unmount the filesystem and verify the content of the ranges was not # modified (no trim/discard happened on them). _scratch_unmount echo "Content of the ranges [0, 64Kb] and [68Kb, 1Mb[ after fitrim:" od -t x1 -N $((64 * 1024)) $SCRATCH_DEV od -t x1 -j $((68 * 1024)) -N $((956 * 1024)) $SCRATCH_DEV status=0 exit Reported-by: Vincent Petry <PVince81@yahoo.fr> Reported-by: Andrei Borzenkov <arvidjaar@gmail.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=109341 Fixes: 499f377f49f0 (btrfs: iterate over unused chunk space in FITRIM) Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25btrfs: handle invalid num_stripes in sys_arrayDavid Sterba
commit f5cdedd73fa71b74dcc42f2a11a5735d89ce7c4f upstream. We can handle the special case of num_stripes == 0 directly inside btrfs_read_sys_array. The BUG_ON in btrfs_chunk_item_size is there to catch other unhandled cases where we fail to validate external data. A crafted or corrupted image crashes at mount time: BTRFS: device fsid 9006933e-2a9a-44f0-917f-514252aeec2c devid 1 transid 7 /dev/loop0 BTRFS info (device loop0): disk space caching is enabled BUG: failure at fs/btrfs/ctree.h:337/btrfs_chunk_item_size()! Kernel panic - not syncing: BUG! CPU: 0 PID: 313 Comm: mount Not tainted 4.2.5-00657-ge047887-dirty #25 Stack: 637af890 60062489 602aeb2e 604192ba 60387961 00000011 637af8a0 6038a835 637af9c0 6038776b 634ef32b 00000000 Call Trace: [<6001c86d>] show_stack+0xfe/0x15b [<6038a835>] dump_stack+0x2a/0x2c [<6038776b>] panic+0x13e/0x2b3 [<6020f099>] btrfs_read_sys_array+0x25d/0x2ff [<601cfbbe>] open_ctree+0x192d/0x27af [<6019c2c1>] btrfs_mount+0x8f5/0xb9a [<600bc9a7>] mount_fs+0x11/0xf3 [<600d5167>] vfs_kern_mount+0x75/0x11a [<6019bcb0>] btrfs_mount+0x2e4/0xb9a [<600bc9a7>] mount_fs+0x11/0xf3 [<600d5167>] vfs_kern_mount+0x75/0x11a [<600d710b>] do_mount+0xa35/0xbc9 [<600d7557>] SyS_mount+0x95/0xc8 [<6001e884>] handle_syscall+0x6b/0x8e Reported-by: Jiri Slaby <jslaby@suse.com> Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-18Merge branch 'for-linus-4.4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes from Chris Mason: "A couple of small fixes" * 'for-linus-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: check prepare_uptodate_page() error code earlier Btrfs: check for empty bitmap list in setup_cluster_bitmaps btrfs: fix misleading warning when space cache failed to load Btrfs: fix transaction handle leak in balance Btrfs: fix unprotected list move from unused_bgs to deleted_bgs list
2015-12-15Merge branch 'for-chris-4.4' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/fdmanana/linux into for-linus-4.4
2015-12-15Btrfs: check prepare_uptodate_page() error code earlierChris Mason
prepare_pages() may end up calling prepare_uptodate_page() twice if our write only spans a single page. But if the first call returns an error, our page will be unlocked and its not safe to call it again. This bug goes all the way back to 2011, and it's not something commonly hit. While we're here, add a more explicit check for the page being truncated away. The bare lock_page() alone is protected only by good thoughts and i_mutex, which we're sure to regret eventually. Reported-by: Dave Jones <dsj@fb.com> Signed-off-by: Chris Mason <clm@fb.com>