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* btrfs: fix percent calculation for bg reclaim messageJohannes Thumshirn2023-03-171-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 95cd356ca23c3807b5f3503687161e216b1c520d upstream. We have a report, that the info message for block-group reclaim is crossing the 100% used mark. This is happening as we were truncating the divisor for the division (the block_group->length) to a 32bit value. Fix this by using div64_u64() to not truncate the divisor. In the worst case, it can lead to a div by zero error and should be possible to trigger on 4 disks RAID0, and each device is large enough: $ mkfs.btrfs -f /dev/test/scratch[1234] -m raid1 -d raid0 btrfs-progs v6.1 [...] Filesystem size: 40.00GiB Block group profiles: Data: RAID0 4.00GiB <<< Metadata: RAID1 256.00MiB System: RAID1 8.00MiB Reported-by: Forza <forza@tnonline.net> Link: https://lore.kernel.org/linux-btrfs/e99483.c11a58d.1863591ca52@tnonline.net/ Fixes: 5f93e776c673 ("btrfs: zoned: print unusable percentage when reclaiming block groups") CC: stable@vger.kernel.org # 5.15+ Reviewed-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> [ add Qu's note ] Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: hold block group refcount during async discardBoris Burkov2023-03-101-3/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | commit 2b5463fcbdfb24e898916bcae2b1359042d26963 upstream. Async discard does not acquire the block group reference count while it holds a reference on the discard list. This is generally OK, as the paths which destroy block groups tend to try to synchronize on cancelling async discard work. However, relying on cancelling work requires careful analysis to be sure it is safe from races with unpinning scheduling more work. While I am unable to find a race with unpinning in the current code for either the unused bgs or relocation paths, I believe we have one in an older version of auto relocation in a Meta internal build. This suggests that this is in fact an error prone model, and could be fragile to future changes to these bg deletion paths. To make this ownership more clear, add a refcount for async discard. If work is queued for a block group, its refcount should be incremented, and when work is completed or canceled, it should be decremented. CC: stable@vger.kernel.org # 5.15+ Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: send: limit number of clones and allocated memory sizeDavid Sterba2023-03-031-3/+3
| | | | | | | | | | | | | | | [ Upstream commit 33e17b3f5ab74af12aca58c515bc8424ff69a343 ] The arg->clone_sources_count is u64 and can trigger a warning when a huge value is passed from user space and a huge array is allocated. Limit the allocated memory to 8MiB (can be increased if needed), which in turn limits the number of clone sources to 8M / sizeof(struct clone_root) = 8M / 40 = 209715. Real world number of clones is from tens to hundreds, so this is future proof. Reported-by: syzbot+4376a9a073770c173269@syzkaller.appspotmail.com Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: free device in btrfs_close_devices for a single device filesystemAnand Jain2023-02-141-1/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 5f58d783fd7823b2c2d5954d1126e702f94bfc4c upstream. We have this check to make sure we don't accidentally add older devices that may have disappeared and re-appeared with an older generation from being added to an fs_devices (such as a replace source device). This makes sense, we don't want stale disks in our file system. However for single disks this doesn't really make sense. I've seen this in testing, but I was provided a reproducer from a project that builds btrfs images on loopback devices. The loopback device gets cached with the new generation, and then if it is re-used to generate a new file system we'll fail to mount it because the new fs is "older" than what we have in cache. Fix this by freeing the cache when closing the device for a single device filesystem. This will ensure that the mount command passed device path is scanned successfully during the next mount. CC: stable@vger.kernel.org # 5.10+ Reported-by: Daan De Meyer <daandemeyer@fb.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> 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>
* btrfs: zlib: zero-initialize zlib workspaceAlexander Potapenko2023-02-141-1/+1
| | | | | | | | | | | | | | | | | commit eadd7deca0ad8a83edb2b894d8326c78e78635d6 upstream. KMSAN reports uses of uninitialized memory in zlib's longest_match() called on memory originating from zlib_alloc_workspace(). This issue is known by zlib maintainers and is claimed to be harmless, but to be on the safe side we'd better initialize the memory. Link: https://zlib.net/zlib_faq.html#faq36 Reported-by: syzbot+14d9e7602ebdf7ec0a60@syzkaller.appspotmail.com CC: stable@vger.kernel.org # 5.4+ Signed-off-by: Alexander Potapenko <glider@google.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: limit device extents to the device sizeJosef Bacik2023-02-141-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 3c538de0f2a74d50aff7278c092f88ae59cee688 upstream. There was a recent regression in btrfs/177 that started happening with the size class patches ("btrfs: introduce size class to block group allocator"). This however isn't a regression introduced by those patches, but rather the bug was uncovered by a change in behavior in these patches. The patches triggered more chunk allocations in the ^free-space-tree case, which uncovered a race with device shrink. The problem is we will set the device total size to the new size, and use this to find a hole for a device extent. However during shrink we may have device extents allocated past this range, so we could potentially find a hole in a range past our new shrink size. We don't actually limit our found extent to the device size anywhere, we assume that we will not find a hole past our device size. This isn't true with shrink as we're relocating block groups and thus creating holes past the device size. Fix this by making sure we do not search past the new device size, and if we wander into any device extents that start after our device size simply break from the loop and use whatever hole we've already found. CC: stable@vger.kernel.org # 4.14+ Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: fix race between quota rescan and disable leading to NULL pointer derefFilipe Manana2023-01-241-8/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit b7adbf9ada3513d2092362c8eac5cddc5b651f5c upstream. If we have one task trying to start the quota rescan worker while another one is trying to disable quotas, we can end up hitting a race that results in the quota rescan worker doing a NULL pointer dereference. The steps for this are the following: 1) Quotas are enabled; 2) Task A calls the quota rescan ioctl and enters btrfs_qgroup_rescan(). It calls qgroup_rescan_init() which returns 0 (success) and then joins a transaction and commits it; 3) Task B calls the quota disable ioctl and enters btrfs_quota_disable(). It clears the bit BTRFS_FS_QUOTA_ENABLED from fs_info->flags and calls btrfs_qgroup_wait_for_completion(), which returns immediately since the rescan worker is not yet running. Then it starts a transaction and locks fs_info->qgroup_ioctl_lock; 4) Task A queues the rescan worker, by calling btrfs_queue_work(); 5) The rescan worker starts, and calls rescan_should_stop() at the start of its while loop, which results in 0 iterations of the loop, since the flag BTRFS_FS_QUOTA_ENABLED was cleared from fs_info->flags by task B at step 3); 6) Task B sets fs_info->quota_root to NULL; 7) The rescan worker tries to start a transaction and uses fs_info->quota_root as the root argument for btrfs_start_transaction(). This results in a NULL pointer dereference down the call chain of btrfs_start_transaction(). The stack trace is something like the one reported in Link tag below: general protection fault, probably for non-canonical address 0xdffffc0000000041: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000208-0x000000000000020f] CPU: 1 PID: 34 Comm: kworker/u4:2 Not tainted 6.1.0-syzkaller-13872-gb6bb9676f216 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Workqueue: btrfs-qgroup-rescan btrfs_work_helper RIP: 0010:start_transaction+0x48/0x10f0 fs/btrfs/transaction.c:564 Code: 48 89 fb 48 (...) RSP: 0018:ffffc90000ab7ab0 EFLAGS: 00010206 RAX: 0000000000000041 RBX: 0000000000000208 RCX: ffff88801779ba80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: dffffc0000000000 R08: 0000000000000001 R09: fffff52000156f5d R10: fffff52000156f5d R11: 1ffff92000156f5c R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2bea75b718 CR3: 000000001d0cc000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> btrfs_qgroup_rescan_worker+0x3bb/0x6a0 fs/btrfs/qgroup.c:3402 btrfs_work_helper+0x312/0x850 fs/btrfs/async-thread.c:280 process_one_work+0x877/0xdb0 kernel/workqueue.c:2289 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 </TASK> Modules linked in: So fix this by having the rescan worker function not attempt to start a transaction if it didn't do any rescan work. Reported-by: syzbot+96977faa68092ad382c4@syzkaller.appspotmail.com Link: https://lore.kernel.org/linux-btrfs/000000000000e5454b05f065a803@google.com/ Fixes: e804861bd4e6 ("btrfs: fix deadlock between quota disable and qgroup rescan worker") CC: stable@vger.kernel.org # 5.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: do not abort transaction on failure to write log tree when syncing logFilipe Manana2023-01-242-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | commit 16199ad9eb6db60a6b10794a09fc1ac6d09312ff upstream. When syncing the log, if we fail to write log tree extent buffers, we mark the log for a full commit and abort the transaction. However we don't need to abort the transaction, all we really need to do is to make sure no one can commit a superblock pointing to new log tree roots. Just because we got a failure writing extent buffers for a log tree, it does not mean we will also fail to do a transaction commit. One particular case is if due to a bug somewhere, when writing log tree extent buffers, the tree checker detects some corruption and the writeout fails because of that. Aborting the transaction can be very disruptive for a user, specially if the issue happened on a root filesystem. One example is the scenario in the Link tag below, where an isolated corruption on log tree leaves was causing transaction aborts when syncing the log. Link: https://lore.kernel.org/linux-btrfs/ae169fc6-f504-28f0-a098-6fa6a4dfb612@leemhuis.info/ CC: stable@vger.kernel.org # 5.15+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: always report error in run_one_delayed_ref()Qu Wenruo2023-01-241-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 39f501d68ec1ed5cd5c66ac6ec2a7131c517bb92 ] Currently we have a btrfs_debug() for run_one_delayed_ref() failure, but if end users hit such problem, there will be no chance that btrfs_debug() is enabled. This can lead to very little useful info for debugging. This patch will: - Add extra info for error reporting Including: * logical bytenr * num_bytes * type * action * ref_mod - Replace the btrfs_debug() with btrfs_err() - Move the error reporting into run_one_delayed_ref() This is to avoid use-after-free, the @node can be freed in the caller. This error should only be triggered at most once. As if run_one_delayed_ref() failed, we trigger the error message, then causing the call chain to error out: btrfs_run_delayed_refs() `- btrfs_run_delayed_refs() `- btrfs_run_delayed_refs_for_head() `- run_one_delayed_ref() And we will abort the current transaction in btrfs_run_delayed_refs(). If we have to run delayed refs for the abort transaction, run_one_delayed_ref() will just cleanup the refs and do nothing, thus no new error messages would be output. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: make thaw time super block check to also verify checksumQu Wenruo2023-01-123-6/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 3d17adea74a56a4965f7a603d8ed8c66bb9356d9 upstream. Previous commit a05d3c915314 ("btrfs: check superblock to ensure the fs was not modified at thaw time") only checks the content of the super block, but it doesn't really check if the on-disk super block has a matching checksum. This patch will add the checksum verification to thaw time superblock verification. This involves the following extra changes: - Export btrfs_check_super_csum() As we need to call it in super.c. - Change the argument list of btrfs_check_super_csum() Instead of passing a char *, directly pass struct btrfs_super_block * pointer. - Verify that our checksum type didn't change before checking the checksum value, like it's done at mount time Fixes: a05d3c915314 ("btrfs: check superblock to ensure the fs was not modified at thaw time") Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: check superblock to ensure the fs was not modified at thaw timeQu Wenruo2023-01-124-8/+83
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit a05d3c9153145283ce9c58a1d7a9056fbb85f6a1 ] [BACKGROUND] There is an incident report that, one user hibernated the system, with one btrfs on removable device still mounted. Then by some incident, the btrfs got mounted and modified by another system/OS, then back to the hibernated system. After resuming from the hibernation, new write happened into the victim btrfs. Now the fs is completely broken, since the underlying btrfs is no longer the same one before the hibernation, and the user lost their data due to various transid mismatch. [REPRODUCER] We can emulate the situation using the following small script: truncate -s 1G $dev mkfs.btrfs -f $dev mount $dev $mnt fsstress -w -d $mnt -n 500 sync xfs_freeze -f $mnt cp $dev $dev.backup # There is no way to mount the same cloned fs on the same system, # as the conflicting fsid will be rejected by btrfs. # Thus here we have to wipe the fs using a different btrfs. mkfs.btrfs -f $dev.backup dd if=$dev.backup of=$dev bs=1M xfs_freeze -u $mnt fsstress -w -d $mnt -n 20 umount $mnt btrfs check $dev The final fsck will fail due to some tree blocks has incorrect fsid. This is enough to emulate the problem hit by the unfortunate user. [ENHANCEMENT] Although such case should not be that common, it can still happen from time to time. From the view of btrfs, we can detect any unexpected super block change, and if there is any unexpected change, we just mark the fs read-only, and thaw the fs. By this we can limit the damage to minimal, and I hope no one would lose their data by this anymore. Suggested-by: Goffredo Baroncelli <kreijack@libero.it> Link: https://lore.kernel.org/linux-btrfs/83bf3b4b-7f4c-387a-b286-9251e3991e34@bluemole.com/ Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: fix an error handling path in btrfs_defrag_leaves()Sasha Levin2023-01-121-2/+4
| | | | | | | | | | | | | | | | | | | [ Upstream commit db0a4a7b8e95f9312a59a67cbd5bc589f090e13d ] All error handling paths end to 'out', except this memory allocation failure. This is spurious. So branch to the error handling path also in this case. It will add a call to: memset(&root->defrag_progress, 0, sizeof(root->defrag_progress)); Fixes: 6702ed490ca0 ("Btrfs: Add run time btree defrag, and an ioctl to force btree defrag") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: fix extent map use-after-free when handling missing device in ↵void0red2023-01-121-1/+2
| | | | | | | | | | | | | | | | | | | | | | read_one_chunk [ Upstream commit 1742e1c90c3da344f3bb9b1f1309b3f47482756a ] Store the error code before freeing the extent_map. Though it's reference counted structure, in that function it's the first and last allocation so this would lead to a potential use-after-free. The error can happen eg. when chunk is stored on a missing device and the degraded mount option is missing. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=216721 Reported-by: eriri <1527030098@qq.com> Fixes: adfb69af7d8c ("btrfs: add_missing_dev() should return the actual error") CC: stable@vger.kernel.org # 4.9+ Signed-off-by: void0red <void0red@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: move missing device handling in a dedicate functionNikolay Borisov2023-01-121-14/+24
| | | | | | | | | | | | | | | [ Upstream commit ff37c89f94be14b0e22a532d1e6d57187bfd5bb8 ] This simplifies the code flow in read_one_chunk and makes error handling when handling missing devices a bit simpler by reducing it to a single check if something went wrong. No functional changes. Reviewed-by: Su Yue <l@damenly.su> Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Stable-dep-of: 1742e1c90c3d ("btrfs: fix extent map use-after-free when handling missing device in read_one_chunk") Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: replace strncpy() with strscpy()Sasha Levin2023-01-122-7/+8
| | | | | | | | | | | | | | | [ Upstream commit 63d5429f68a3d4c4aa27e65a05196c17f86c41d6 ] Using strncpy() on NUL-terminated strings are deprecated. To avoid possible forming of non-terminated string strscpy() should be used. Found by Linux Verification Center (linuxtesting.org) with SVACE. CC: stable@vger.kernel.org # 4.9+ Signed-off-by: Artem Chernyshev <artem.chernyshev@red-soft.ru> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: fix resolving backrefs for inline extent followed by preallocBoris Burkov2023-01-121-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 560840afc3e63bbe5d9c5ef6b2ecf8f3589adff6 upstream. If a file consists of an inline extent followed by a regular or prealloc extent, then a legitimate attempt to resolve a logical address in the non-inline region will result in add_all_parents reading the invalid offset field of the inline extent. If the inline extent item is placed in the leaf eb s.t. it is the first item, attempting to access the offset field will not only be meaningless, it will go past the end of the eb and cause this panic: [17.626048] BTRFS warning (device dm-2): bad eb member end: ptr 0x3fd4 start 30834688 member offset 16377 size 8 [17.631693] general protection fault, probably for non-canonical address 0x5088000000000: 0000 [#1] SMP PTI [17.635041] CPU: 2 PID: 1267 Comm: btrfs Not tainted 5.12.0-07246-g75175d5adc74-dirty #199 [17.637969] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [17.641995] RIP: 0010:btrfs_get_64+0xe7/0x110 [17.649890] RSP: 0018:ffffc90001f73a08 EFLAGS: 00010202 [17.651652] RAX: 0000000000000001 RBX: ffff88810c42d000 RCX: 0000000000000000 [17.653921] RDX: 0005088000000000 RSI: ffffc90001f73a0f RDI: 0000000000000001 [17.656174] RBP: 0000000000000ff9 R08: 0000000000000007 R09: c0000000fffeffff [17.658441] R10: ffffc90001f73790 R11: ffffc90001f73788 R12: ffff888106afe918 [17.661070] R13: 0000000000003fd4 R14: 0000000000003f6f R15: cdcdcdcdcdcdcdcd [17.663617] FS: 00007f64e7627d80(0000) GS:ffff888237c80000(0000) knlGS:0000000000000000 [17.666525] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [17.668664] CR2: 000055d4a39152e8 CR3: 000000010c596002 CR4: 0000000000770ee0 [17.671253] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [17.673634] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [17.676034] PKRU: 55555554 [17.677004] Call Trace: [17.677877] add_all_parents+0x276/0x480 [17.679325] find_parent_nodes+0xfae/0x1590 [17.680771] btrfs_find_all_leafs+0x5e/0xa0 [17.682217] iterate_extent_inodes+0xce/0x260 [17.683809] ? btrfs_inode_flags_to_xflags+0x50/0x50 [17.685597] ? iterate_inodes_from_logical+0xa1/0xd0 [17.687404] iterate_inodes_from_logical+0xa1/0xd0 [17.689121] ? btrfs_inode_flags_to_xflags+0x50/0x50 [17.691010] btrfs_ioctl_logical_to_ino+0x131/0x190 [17.692946] btrfs_ioctl+0x104a/0x2f60 [17.694384] ? selinux_file_ioctl+0x182/0x220 [17.695995] ? __x64_sys_ioctl+0x84/0xc0 [17.697394] __x64_sys_ioctl+0x84/0xc0 [17.698697] do_syscall_64+0x33/0x40 [17.700017] entry_SYSCALL_64_after_hwframe+0x44/0xae [17.701753] RIP: 0033:0x7f64e72761b7 [17.709355] RSP: 002b:00007ffefb067f58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [17.712088] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f64e72761b7 [17.714667] RDX: 00007ffefb067fb0 RSI: 00000000c0389424 RDI: 0000000000000003 [17.717386] RBP: 00007ffefb06d188 R08: 000055d4a390d2b0 R09: 00007f64e7340a60 [17.719938] R10: 0000000000000231 R11: 0000000000000246 R12: 0000000000000001 [17.722383] R13: 0000000000000000 R14: 00000000c0389424 R15: 000055d4a38fd2a0 [17.724839] Modules linked in: Fix the bug by detecting the inline extent item in add_all_parents and skipping to the next extent item. CC: stable@vger.kernel.org # 4.9+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: do not BUG_ON() on ENOMEM when dropping extent items for a rangeFilipe Manana2022-12-311-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 162d053e15fe985f754ef495a96eb3db970c43ed upstream. If we get -ENOMEM while dropping file extent items in a given range, at btrfs_drop_extents(), due to failure to allocate memory when attempting to increment the reference count for an extent or drop the reference count, we handle it with a BUG_ON(). This is excessive, instead we can simply abort the transaction and return the error to the caller. In fact most callers of btrfs_drop_extents(), directly or indirectly, already abort the transaction if btrfs_drop_extents() returns any error. Also, we already have error paths at btrfs_drop_extents() that may return -ENOMEM and in those cases we abort the transaction, like for example anything that changes the b+tree may return -ENOMEM due to a failure to allocate a new extent buffer when COWing an existing extent buffer, such as a call to btrfs_duplicate_item() for example. So replace the BUG_ON() calls with proper logic to abort the transaction and return the error. Reported-by: syzbot+0b1fb6b0108c27419f9f@syzkaller.appspotmail.com Link: https://lore.kernel.org/linux-btrfs/00000000000089773e05ee4b9cb4@google.com/ CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: send: avoid unaligned encoded writes when attempting to clone rangeFilipe Manana2022-12-141-1/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit a11452a3709e217492798cf3686ac2cc8eb3fb51 ] When trying to see if we can clone a file range, there are cases where we end up sending two write operations in case the inode from the source root has an i_size that is not sector size aligned and the length from the current offset to its i_size is less than the remaining length we are trying to clone. Issuing two write operations when we could instead issue a single write operation is not incorrect. However it is not optimal, specially if the extents are compressed and the flag BTRFS_SEND_FLAG_COMPRESSED was passed to the send ioctl. In that case we can end up sending an encoded write with an offset that is not sector size aligned, which makes the receiver fallback to decompressing the data and writing it using regular buffered IO (so re-compressing the data in case the fs is mounted with compression enabled), because encoded writes fail with -EINVAL when an offset is not sector size aligned. The following example, which triggered a bug in the receiver code for the fallback logic of decompressing + regular buffer IO and is fixed by the patchset referred in a Link at the bottom of this changelog, is an example where we have the non-optimal behaviour due to an unaligned encoded write: $ cat test.sh #!/bin/bash DEV=/dev/sdj MNT=/mnt/sdj mkfs.btrfs -f $DEV > /dev/null mount -o compress $DEV $MNT # File foo has a size of 33K, not aligned to the sector size. xfs_io -f -c "pwrite -S 0xab 0 33K" $MNT/foo xfs_io -f -c "pwrite -S 0xcd 0 64K" $MNT/bar # Now clone the first 32K of file bar into foo at offset 0. xfs_io -c "reflink $MNT/bar 0 0 32K" $MNT/foo # Snapshot the default subvolume and create a full send stream (v2). btrfs subvolume snapshot -r $MNT $MNT/snap btrfs send --compressed-data -f /tmp/test.send $MNT/snap echo -e "\nFile bar in the original filesystem:" od -A d -t x1 $MNT/snap/bar umount $MNT mkfs.btrfs -f $DEV > /dev/null mount $DEV $MNT echo -e "\nReceiving stream in a new filesystem..." btrfs receive -f /tmp/test.send $MNT echo -e "\nFile bar in the new filesystem:" od -A d -t x1 $MNT/snap/bar umount $MNT Before this patch, the send stream included one regular write and one encoded write for file 'bar', with the later being not sector size aligned and causing the receiver to fallback to decompression + buffered writes. The output of the btrfs receive command in verbose mode (-vvv): (...) mkfile o258-7-0 rename o258-7-0 -> bar utimes clone bar - source=foo source offset=0 offset=0 length=32768 write bar - offset=32768 length=1024 encoded_write bar - offset=33792, len=4096, unencoded_offset=33792, unencoded_file_len=31744, unencoded_len=65536, compression=1, encryption=0 encoded_write bar - falling back to decompress and write due to errno 22 ("Invalid argument") (...) This patch avoids the regular write followed by an unaligned encoded write so that we end up sending a single encoded write that is aligned. So after this patch the stream content is (output of btrfs receive -vvv): (...) mkfile o258-7-0 rename o258-7-0 -> bar utimes clone bar - source=foo source offset=0 offset=0 length=32768 encoded_write bar - offset=32768, len=4096, unencoded_offset=32768, unencoded_file_len=32768, unencoded_len=65536, compression=1, encryption=0 (...) So we get more optimal behaviour and avoid the silent data loss bug in versions of btrfs-progs affected by the bug referred by the Link tag below (btrfs-progs v5.19, v5.19.1, v6.0 and v6.0.1). Link: https://lore.kernel.org/linux-btrfs/cover.1668529099.git.fdmanana@suse.com/ Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: qgroup: fix sleep from invalid context bug in btrfs_qgroup_inherit()ChenXiaoSong2022-12-081-8/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit f7e942b5bb35d8e3af54053d19a6bf04143a3955 ] Syzkaller reported BUG as follows: BUG: sleeping function called from invalid context at include/linux/sched/mm.h:274 Call Trace: <TASK> dump_stack_lvl+0xcd/0x134 __might_resched.cold+0x222/0x26b kmem_cache_alloc+0x2e7/0x3c0 update_qgroup_limit_item+0xe1/0x390 btrfs_qgroup_inherit+0x147b/0x1ee0 create_subvol+0x4eb/0x1710 btrfs_mksubvol+0xfe5/0x13f0 __btrfs_ioctl_snap_create+0x2b0/0x430 btrfs_ioctl_snap_create_v2+0x25a/0x520 btrfs_ioctl+0x2a1c/0x5ce0 __x64_sys_ioctl+0x193/0x200 do_syscall_64+0x35/0x80 Fix this by calling qgroup_dirty() on @dstqgroup, and update limit item in btrfs_run_qgroups() later outside of the spinlock context. CC: stable@vger.kernel.org # 4.9+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: move QUOTA_ENABLED check to rescan_should_stop from ↵Nikolay Borisov2022-12-081-7/+6
| | | | | | | | | | | | | | | | | | btrfs_qgroup_rescan_worker [ Upstream commit db5df254120004471e1c957957ab2f1e612dcbd6 ] Instead of having 2 places that short circuit the qgroup leaf scan have everything in the qgroup_rescan_leaf function. In addition to that, also ensure that the inconsistent qgroup flag is set when rescan_should_stop returns true. This both retains the old behavior when -EINTR was set in the body of the loop and at the same time also extends this behavior when scanning is interrupted due to remount or unmount operations. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Stable-dep-of: f7e942b5bb35 ("btrfs: qgroup: fix sleep from invalid context bug in btrfs_qgroup_inherit()") Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: free btrfs_path before copying inodes to userspaceAnand Jain2022-12-081-9/+7
| | | | | | | | | | | | | | | | [ Upstream commit 418ffb9e3cf6c4e2574d3a732b724916684bd133 ] btrfs_ioctl_logical_to_ino() frees the search path after the userspace copy from the temp buffer @inodes. Which potentially can lead to a lock splat. Fix this by freeing the path before we copy @inodes to userspace. CC: stable@vger.kernel.org # 4.19+ 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: Sasha Levin <sashal@kernel.org>
* btrfs: sink iterator parameter to btrfs_ioctl_logical_to_inoDavid Sterba2022-12-083-26/+24
| | | | | | | | | | | | [ Upstream commit e3059ec06b9f1a96826cc2bb6ed131aac0942446 ] There's only one function we pass to iterate_inodes_from_logical as iterator, so we can drop the indirection and call it directly, after moving the function to backref.c Signed-off-by: David Sterba <dsterba@suse.com> Stable-dep-of: 418ffb9e3cf6 ("btrfs: free btrfs_path before copying inodes to userspace") Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: sysfs: normalize the error handling branch in btrfs_init_sysfs()Zhen Lei2022-12-021-2/+5
| | | | | | | | | | | | | | | commit ffdbb44f2f23f963b8f5672e35c3a26088177a62 upstream. Although kset_unregister() can eventually remove all attribute files, explicitly rolling back with the matching function makes the code logic look clearer. CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: use kvcalloc in btrfs_get_dev_zone_infoChristoph Hellwig2022-12-021-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 8fe97d47b52ae1ad130470b1780f0ded4ba609a4 upstream. Otherwise the kernel memory allocator seems to be unhappy about failing order 6 allocations for the zones array, that cause 100% reproducible mount failures in my qemu setup: [26.078981] mount: page allocation failure: order:6, mode:0x40dc0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), nodemask=(null) [26.079741] CPU: 0 PID: 2965 Comm: mount Not tainted 6.1.0-rc5+ #185 [26.080181] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [26.080950] Call Trace: [26.081132] <TASK> [26.081291] dump_stack_lvl+0x56/0x6f [26.081554] warn_alloc+0x117/0x140 [26.081808] ? __alloc_pages_direct_compact+0x1b5/0x300 [26.082174] __alloc_pages_slowpath.constprop.0+0xd0e/0xde0 [26.082569] __alloc_pages+0x32a/0x340 [26.082836] __kmalloc_large_node+0x4d/0xa0 [26.083133] ? trace_kmalloc+0x29/0xd0 [26.083399] kmalloc_large+0x14/0x60 [26.083654] btrfs_get_dev_zone_info+0x1b9/0xc00 [26.083980] ? _raw_spin_unlock_irqrestore+0x28/0x50 [26.084328] btrfs_get_dev_zone_info_all_devices+0x54/0x80 [26.084708] open_ctree+0xed4/0x1654 [26.084974] btrfs_mount_root.cold+0x12/0xde [26.085288] ? lock_is_held_type+0xe2/0x140 [26.085603] legacy_get_tree+0x28/0x50 [26.085876] vfs_get_tree+0x1d/0xb0 [26.086139] vfs_kern_mount.part.0+0x6c/0xb0 [26.086456] btrfs_mount+0x118/0x3a0 [26.086728] ? lock_is_held_type+0xe2/0x140 [26.087043] legacy_get_tree+0x28/0x50 [26.087323] vfs_get_tree+0x1d/0xb0 [26.087587] path_mount+0x2ba/0xbe0 [26.087850] ? _raw_spin_unlock_irqrestore+0x38/0x50 [26.088217] __x64_sys_mount+0xfe/0x140 [26.088506] do_syscall_64+0x35/0x80 [26.088776] entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: 5b316468983d ("btrfs: get zone information of zoned block devices") CC: stable@vger.kernel.org # 5.15+ Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: zoned: fix missing endianness conversion in sb_write_pointerChristoph Hellwig2022-12-021-1/+2
| | | | | | | | | | | | | | | | commit c51f0e6a1254b3ac2d308e1c6fd8fb936992b455 upstream. generation is an on-disk __le64 value, so use btrfs_super_generation to convert it to host endian before comparing it. Fixes: 12659251ca5d ("btrfs: implement log-structured superblock for ZONED mode") CC: stable@vger.kernel.org # 5.15+ Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: free btrfs_path before copying subvol info to userspaceAnand Jain2022-12-021-0/+2
| | | | | | | | | | | | | | | | commit 013c1c5585ebcfb19c88efe79063d0463b1b6159 upstream. btrfs_ioctl_get_subvol_info() frees the search path after the userspace copy from the temp buffer @subvol_info. This can lead to a lock splat warning. Fix this by freeing the path before we copy it to userspace. CC: stable@vger.kernel.org # 4.19+ 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>
* btrfs: free btrfs_path before copying fspath to userspaceAnand Jain2022-12-021-0/+2
| | | | | | | | | | | | | | | | commit 8cf96b409d9b3946ece58ced13f92d0f775b0442 upstream. btrfs_ioctl_ino_to_path() frees the search path after the userspace copy from the temp buffer @ipath->fspath. Which potentially can lead to a lock splat warning. Fix this by freeing the path before we copy it to userspace. CC: stable@vger.kernel.org # 4.19+ 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>
* btrfs: free btrfs_path before copying root refs to userspaceJosef Bacik2022-12-021-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit b740d806166979488e798e41743aaec051f2443f upstream. Syzbot reported the following lockdep splat ====================================================== WARNING: possible circular locking dependency detected 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Not tainted ------------------------------------------------------ syz-executor307/3029 is trying to acquire lock: ffff0000c02525d8 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0x54/0xb4 mm/memory.c:5576 but task is already holding lock: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline] ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline] ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (btrfs-root-00){++++}-{3:3}: down_read_nested+0x64/0x84 kernel/locking/rwsem.c:1624 __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline] btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline] btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279 btrfs_search_slot_get_root+0x74/0x338 fs/btrfs/ctree.c:1637 btrfs_search_slot+0x1b0/0xfd8 fs/btrfs/ctree.c:1944 btrfs_update_root+0x6c/0x5a0 fs/btrfs/root-tree.c:132 commit_fs_roots+0x1f0/0x33c fs/btrfs/transaction.c:1459 btrfs_commit_transaction+0x89c/0x12d8 fs/btrfs/transaction.c:2343 flush_space+0x66c/0x738 fs/btrfs/space-info.c:786 btrfs_async_reclaim_metadata_space+0x43c/0x4e0 fs/btrfs/space-info.c:1059 process_one_work+0x2d8/0x504 kernel/workqueue.c:2289 worker_thread+0x340/0x610 kernel/workqueue.c:2436 kthread+0x12c/0x158 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 -> #2 (&fs_info->reloc_mutex){+.+.}-{3:3}: __mutex_lock_common+0xd4/0xca8 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 btrfs_record_root_in_trans fs/btrfs/transaction.c:516 [inline] start_transaction+0x248/0x944 fs/btrfs/transaction.c:752 btrfs_start_transaction+0x34/0x44 fs/btrfs/transaction.c:781 btrfs_create_common+0xf0/0x1b4 fs/btrfs/inode.c:6651 btrfs_create+0x8c/0xb0 fs/btrfs/inode.c:6697 lookup_open fs/namei.c:3413 [inline] open_last_lookups fs/namei.c:3481 [inline] path_openat+0x804/0x11c4 fs/namei.c:3688 do_filp_open+0xdc/0x1b8 fs/namei.c:3718 do_sys_openat2+0xb8/0x22c fs/open.c:1313 do_sys_open fs/open.c:1329 [inline] __do_sys_openat fs/open.c:1345 [inline] __se_sys_openat fs/open.c:1340 [inline] __arm64_sys_openat+0xb0/0xe0 fs/open.c:1340 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 -> #1 (sb_internal#2){.+.+}-{0:0}: percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1826 [inline] sb_start_intwrite include/linux/fs.h:1948 [inline] start_transaction+0x360/0x944 fs/btrfs/transaction.c:683 btrfs_join_transaction+0x30/0x40 fs/btrfs/transaction.c:795 btrfs_dirty_inode+0x50/0x140 fs/btrfs/inode.c:6103 btrfs_update_time+0x1c0/0x1e8 fs/btrfs/inode.c:6145 inode_update_time fs/inode.c:1872 [inline] touch_atime+0x1f0/0x4a8 fs/inode.c:1945 file_accessed include/linux/fs.h:2516 [inline] btrfs_file_mmap+0x50/0x88 fs/btrfs/file.c:2407 call_mmap include/linux/fs.h:2192 [inline] mmap_region+0x7fc/0xc14 mm/mmap.c:1752 do_mmap+0x644/0x97c mm/mmap.c:1540 vm_mmap_pgoff+0xe8/0x1d0 mm/util.c:552 ksys_mmap_pgoff+0x1cc/0x278 mm/mmap.c:1586 __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline] __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline] __arm64_sys_mmap+0x58/0x6c arch/arm64/kernel/sys.c:21 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 -> #0 (&mm->mmap_lock){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3829 [inline] __lock_acquire+0x1530/0x30a4 kernel/locking/lockdep.c:5053 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666 __might_fault+0x7c/0xb4 mm/memory.c:5577 _copy_to_user include/linux/uaccess.h:134 [inline] copy_to_user include/linux/uaccess.h:160 [inline] btrfs_ioctl_get_subvol_rootref+0x3a8/0x4bc fs/btrfs/ioctl.c:3203 btrfs_ioctl+0xa08/0xa64 fs/btrfs/ioctl.c:5556 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0xd0/0x140 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 other info that might help us debug this: Chain exists of: &mm->mmap_lock --> &fs_info->reloc_mutex --> btrfs-root-00 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(btrfs-root-00); lock(&fs_info->reloc_mutex); lock(btrfs-root-00); lock(&mm->mmap_lock); *** DEADLOCK *** 1 lock held by syz-executor307/3029: #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline] #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline] #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279 stack backtrace: CPU: 0 PID: 3029 Comm: syz-executor307 Not tainted 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022 Call trace: dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:156 show_stack+0x2c/0x54 arch/arm64/kernel/stacktrace.c:163 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x104/0x16c lib/dump_stack.c:106 dump_stack+0x1c/0x58 lib/dump_stack.c:113 print_circular_bug+0x2c4/0x2c8 kernel/locking/lockdep.c:2053 check_noncircular+0x14c/0x154 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3829 [inline] __lock_acquire+0x1530/0x30a4 kernel/locking/lockdep.c:5053 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666 __might_fault+0x7c/0xb4 mm/memory.c:5577 _copy_to_user include/linux/uaccess.h:134 [inline] copy_to_user include/linux/uaccess.h:160 [inline] btrfs_ioctl_get_subvol_rootref+0x3a8/0x4bc fs/btrfs/ioctl.c:3203 btrfs_ioctl+0xa08/0xa64 fs/btrfs/ioctl.c:5556 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0xd0/0x140 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 We do generally the right thing here, copying the references into a temporary buffer, however we are still holding the path when we do copy_to_user from the temporary buffer. Fix this by freeing the path before we copy to user space. Reported-by: syzbot+4ef9e52e464c6ff47d9d@syzkaller.appspotmail.com CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: remove pointless and double ulist frees in error paths of qgroup testsFilipe Manana2022-11-261-12/+4
| | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit d0ea17aec12ea0f7b9d2ed727d8ef8169d1e7699 ] Several places in the qgroup self tests follow the pattern of freeing the ulist pointer they passed to btrfs_find_all_roots() if the call to that function returned an error. That is pointless because that function always frees the ulist in case it returns an error. Also In some places like at test_multiple_refs(), after a call to btrfs_qgroup_account_extent() we also leave "old_roots" and "new_roots" pointing to ulists that were freed, because btrfs_qgroup_account_extent() has freed those ulists, and if after that the next call to btrfs_find_all_roots() fails, we call ulist_free() on the "old_roots" ulist again, resulting in a double free. So remove those calls to reduce the code size and avoid double ulist free in case of an error. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: raid56: properly handle the error when unable to find the missing stripeQu Wenruo2022-11-261-2/+4
| | | | | | | | | | | | | | | | | | | | | | [ Upstream commit f15fb2cd979a07fbfc666e2f04b8b30ec9233b2a ] In raid56_alloc_missing_rbio(), if we can not determine where the missing device is inside the full stripe, we just BUG_ON(). This is not necessary especially the only caller inside scrub.c is already properly checking the return value, and will treat it as a memory allocation failure. Fix the error handling by: - Add an extra warning for the reason Although personally speaking it may be better to be an ASSERT(). - Properly free the allocated rbio Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: zoned: initialize device's zone info for seedingJohannes Thumshirn2022-11-163-4/+13
| | | | | | | | | | | | | | | commit a8d1b1647bf8244a5f270538e9e636e2657fffa3 upstream. When performing seeding on a zoned filesystem it is necessary to initialize each zoned device's btrfs_zoned_device_info structure, otherwise mounting the filesystem will cause a NULL pointer dereference. This was uncovered by fstests' testcase btrfs/163. CC: stable@vger.kernel.org # 5.15+ Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: selftests: fix wrong error check in btrfs_free_dummy_root()Zhang Xiaoxu2022-11-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 9b2f20344d450137d015b380ff0c2e2a6a170135 upstream. The btrfs_alloc_dummy_root() uses ERR_PTR as the error return value rather than NULL, if error happened, there will be a NULL pointer dereference: BUG: KASAN: null-ptr-deref in btrfs_free_dummy_root+0x21/0x50 [btrfs] Read of size 8 at addr 000000000000002c by task insmod/258926 CPU: 2 PID: 258926 Comm: insmod Tainted: G W 6.1.0-rc2+ #5 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x34/0x44 kasan_report+0xb7/0x140 kasan_check_range+0x145/0x1a0 btrfs_free_dummy_root+0x21/0x50 [btrfs] btrfs_test_free_space_cache+0x1a8c/0x1add [btrfs] btrfs_run_sanity_tests+0x65/0x80 [btrfs] init_btrfs_fs+0xec/0x154 [btrfs] do_one_initcall+0x87/0x2a0 do_init_module+0xdf/0x320 load_module+0x3006/0x3390 __do_sys_finit_module+0x113/0x1b0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Fixes: aaedb55bc08f ("Btrfs: add tests for btrfs_get_extent") CC: stable@vger.kernel.org # 4.9+ Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: fix match incorrectly in dev_args_match_deviceLiu Shixin2022-11-161-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | commit 0fca385d6ebc3cabb20f67bcf8a71f1448bdc001 upstream. syzkaller found a failed assertion: assertion failed: (args->devid != (u64)-1) || args->missing, in fs/btrfs/volumes.c:6921 This can be triggered when we set devid to (u64)-1 by ioctl. In this case, the match of devid will be skipped and the match of device may succeed incorrectly. Patch 562d7b1512f7 introduced this function which is used to match device. This function contains two matching scenarios, we can distinguish them by checking the value of args->missing rather than check whether args->devid and args->uuid is default value. Reported-by: syzbot+031687116258450f9853@syzkaller.appspotmail.com Fixes: 562d7b1512f7 ("btrfs: handle device lookup with btrfs_dev_lookup_args") CC: stable@vger.kernel.org # 5.16+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Liu Shixin <liushixin2@huawei.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: fix type of parameter generation in btrfs_get_dentryDavid Sterba2022-11-102-2/+2
| | | | | | | | | | | | | commit 2398091f9c2c8e0040f4f9928666787a3e8108a7 upstream. The type of parameter generation has been u32 since the beginning, however all callers pass a u64 generation, so unify the types to prevent potential loss. CC: stable@vger.kernel.org # 4.9+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: fix tree mod log mishandling of reallocated nodesJosef Bacik2022-11-101-12/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 968b71583130b6104c9f33ba60446d598e327a8b upstream. We have been seeing the following panic in production kernel BUG at fs/btrfs/tree-mod-log.c:677! invalid opcode: 0000 [#1] SMP RIP: 0010:tree_mod_log_rewind+0x1b4/0x200 RSP: 0000:ffffc9002c02f890 EFLAGS: 00010293 RAX: 0000000000000003 RBX: ffff8882b448c700 RCX: 0000000000000000 RDX: 0000000000008000 RSI: 00000000000000a7 RDI: ffff88877d831c00 RBP: 0000000000000002 R08: 000000000000009f R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000100c40 R12: 0000000000000001 R13: ffff8886c26d6a00 R14: ffff88829f5424f8 R15: ffff88877d831a00 FS: 00007fee1d80c780(0000) GS:ffff8890400c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fee1963a020 CR3: 0000000434f33002 CR4: 00000000007706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: btrfs_get_old_root+0x12b/0x420 btrfs_search_old_slot+0x64/0x2f0 ? tree_mod_log_oldest_root+0x3d/0xf0 resolve_indirect_ref+0xfd/0x660 ? ulist_alloc+0x31/0x60 ? kmem_cache_alloc_trace+0x114/0x2c0 find_parent_nodes+0x97a/0x17e0 ? ulist_alloc+0x30/0x60 btrfs_find_all_roots_safe+0x97/0x150 iterate_extent_inodes+0x154/0x370 ? btrfs_search_path_in_tree+0x240/0x240 iterate_inodes_from_logical+0x98/0xd0 ? btrfs_search_path_in_tree+0x240/0x240 btrfs_ioctl_logical_to_ino+0xd9/0x180 btrfs_ioctl+0xe2/0x2ec0 ? __mod_memcg_lruvec_state+0x3d/0x280 ? do_sys_openat2+0x6d/0x140 ? kretprobe_dispatcher+0x47/0x70 ? kretprobe_rethook_handler+0x38/0x50 ? rethook_trampoline_handler+0x82/0x140 ? arch_rethook_trampoline_callback+0x3b/0x50 ? kmem_cache_free+0xfb/0x270 ? do_sys_openat2+0xd5/0x140 __x64_sys_ioctl+0x71/0xb0 do_syscall_64+0x2d/0x40 Which is this code in tree_mod_log_rewind() switch (tm->op) { case BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING: BUG_ON(tm->slot < n); This occurs because we replay the nodes in order that they happened, and when we do a REPLACE we will log a REMOVE_WHILE_FREEING for every slot, starting at 0. 'n' here is the number of items in this block, which in this case was 1, but we had 2 REMOVE_WHILE_FREEING operations. The actual root cause of this was that we were replaying operations for a block that shouldn't have been replayed. Consider the following sequence of events 1. We have an already modified root, and we do a btrfs_get_tree_mod_seq(). 2. We begin removing items from this root, triggering KEY_REPLACE for it's child slots. 3. We remove one of the 2 children this root node points to, thus triggering the root node promotion of the remaining child, and freeing this node. 4. We modify a new root, and re-allocate the above node to the root node of this other root. The tree mod log looks something like this logical 0 op KEY_REPLACE (slot 1) seq 2 logical 0 op KEY_REMOVE (slot 1) seq 3 logical 0 op KEY_REMOVE_WHILE_FREEING (slot 0) seq 4 logical 4096 op LOG_ROOT_REPLACE (old logical 0) seq 5 logical 8192 op KEY_REMOVE_WHILE_FREEING (slot 1) seq 6 logical 8192 op KEY_REMOVE_WHILE_FREEING (slot 0) seq 7 logical 0 op LOG_ROOT_REPLACE (old logical 8192) seq 8 >From here the bug is triggered by the following steps 1. Call btrfs_get_old_root() on the new_root. 2. We call tree_mod_log_oldest_root(btrfs_root_node(new_root)), which is currently logical 0. 3. tree_mod_log_oldest_root() calls tree_mod_log_search_oldest(), which gives us the KEY_REPLACE seq 2, and since that's not a LOG_ROOT_REPLACE we incorrectly believe that we don't have an old root, because we expect that the most recent change should be a LOG_ROOT_REPLACE. 4. Back in tree_mod_log_oldest_root() we don't have a LOG_ROOT_REPLACE, so we don't set old_root, we simply use our existing extent buffer. 5. Since we're using our existing extent buffer (logical 0) we call tree_mod_log_search(0) in order to get the newest change to start the rewind from, which ends up being the LOG_ROOT_REPLACE at seq 8. 6. Again since we didn't find an old_root we simply clone logical 0 at it's current state. 7. We call tree_mod_log_rewind() with the cloned extent buffer. 8. Set n = btrfs_header_nritems(logical 0), which would be whatever the original nritems was when we COWed the original root, say for this example it's 2. 9. We start from the newest operation and work our way forward, so we see LOG_ROOT_REPLACE which we ignore. 10. Next we see KEY_REMOVE_WHILE_FREEING for slot 0, which triggers the BUG_ON(tm->slot < n), because it expects if we've done this we have a completely empty extent buffer to replay completely. The correct thing would be to find the first LOG_ROOT_REPLACE, and then get the old_root set to logical 8192. In fact making that change fixes this particular problem. However consider the much more complicated case. We have a child node in this tree and the above situation. In the above case we freed one of the child blocks at the seq 3 operation. If this block was also re-allocated and got new tree mod log operations we would have a different problem. btrfs_search_old_slot(orig root) would get down to the logical 0 root that still pointed at that node. However in btrfs_search_old_slot() we call tree_mod_log_rewind(buf) directly. This is not context aware enough to know which operations we should be replaying. If the block was re-allocated multiple times we may only want to replay a range of operations, and determining what that range is isn't possible to determine. We could maybe solve this by keeping track of which root the node belonged to at every tree mod log operation, and then passing this around to make sure we're only replaying operations that relate to the root we're trying to rewind. However there's a simpler way to solve this problem, simply disallow reallocations if we have currently running tree mod log users. We already do this for leaf's, so we're simply expanding this to nodes as well. This is a relatively uncommon occurrence, and the problem is complicated enough I'm worried that we will still have corner cases in the reallocation case. So fix this in the most straightforward way possible. Fixes: bd989ba359f2 ("Btrfs: add tree modification log functions") CC: stable@vger.kernel.org # 3.3+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: fix lost file sync on direct IO write with nowait and dsync iocbFilipe Manana2022-11-101-23/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 8184620ae21213d51eaf2e0bd4186baacb928172 upstream. When doing a direct IO write using a iocb with nowait and dsync set, we end up not syncing the file once the write completes. This is because we tell iomap to not call generic_write_sync(), which would result in calling btrfs_sync_file(), in order to avoid a deadlock since iomap can call it while we are holding the inode's lock and btrfs_sync_file() needs to acquire the inode's lock. The deadlock happens only if the write happens synchronously, when iomap_dio_rw() calls iomap_dio_complete() before it returns. Instead we do the sync ourselves at btrfs_do_write_iter(). For a nowait write however we can end up not doing the sync ourselves at at btrfs_do_write_iter() because the write could have been queued, and therefore we get -EIOCBQUEUED returned from iomap in such case. That makes us skip the sync call at btrfs_do_write_iter(), as we don't do it for any error returned from btrfs_direct_write(). We can't simply do the call even if -EIOCBQUEUED is returned, since that would block the task waiting for IO, both for the data since there are bios still in progress as well as potentially blocking when joining a log transaction and when syncing the log (writing log trees, super blocks, etc). So let iomap do the sync call itself and in order to avoid deadlocks for the case of synchronous writes (without nowait), use __iomap_dio_rw() and have ourselves call iomap_dio_complete() after unlocking the inode. A test case will later be sent for fstests, after this is fixed in Linus' tree. Fixes: 51bd9563b678 ("btrfs: fix deadlock due to page faults during direct IO reads and writes") Reported-by: Марк Коренберг <socketpair@gmail.com> Link: https://lore.kernel.org/linux-btrfs/CAEmTpZGRKbzc16fWPvxbr6AfFsQoLmz-Lcg-7OgJOZDboJ+SGQ@mail.gmail.com/ CC: stable@vger.kernel.org # 6.0+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: fix ulist leaks in error paths of qgroup self testsFilipe Manana2022-11-101-5/+15
| | | | | | | | | | | | | | | [ Upstream commit d37de92b38932d40e4a251e876cc388f9aee5f42 ] In the test_no_shared_qgroup() and test_multiple_refs() qgroup self tests, if we fail to add the tree ref, remove the extent item or remove the extent ref, we are returning from the test function without freeing the "old_roots" ulist that was allocated by the previous calls to btrfs_find_all_roots(). Fix that by calling ulist_free() before returning. Fixes: 442244c96332 ("btrfs: qgroup: Switch self test to extent-oriented qgroup mechanism.") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: fix inode list leak during backref walking at find_parent_nodes()Filipe Manana2022-11-101-1/+17
| | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 92876eec382a0f19f33d09d2c939e9ca49038ae5 ] During backref walking, at find_parent_nodes(), if we are dealing with a data extent and we get an error while resolving the indirect backrefs, at resolve_indirect_refs(), or in the while loop that iterates over the refs in the direct refs rbtree, we end up leaking the inode lists attached to the direct refs we have in the direct refs rbtree that were not yet added to the refs ulist passed as argument to find_parent_nodes(). Since they were not yet added to the refs ulist and prelim_release() does not free the lists, on error the caller can only free the lists attached to the refs that were added to the refs ulist, all the remaining refs get their inode lists never freed, therefore leaking their memory. Fix this by having prelim_release() always free any attached inode list to each ref found in the rbtree, and have find_parent_nodes() set the ref's inode list to NULL once it transfers ownership of the inode list to a ref added to the refs ulist passed to find_parent_nodes(). Fixes: 86d5f9944252 ("btrfs: convert prelimary reference tracking to use rbtrees") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: fix inode list leak during backref walking at resolve_indirect_refs()Filipe Manana2022-11-101-19/+17
| | | | | | | | | | | | | | | | | | | | | [ Upstream commit 5614dc3a47e3310fbc77ea3b67eaadd1c6417bf1 ] During backref walking, at resolve_indirect_refs(), if we get an error we jump to the 'out' label and call ulist_free() on the 'parents' ulist, which frees all the elements in the ulist - however that does not free any inode lists that may be attached to elements, through the 'aux' field of a ulist node, so we end up leaking lists if we have any attached to the unodes. Fix this by calling free_leaf_list() instead of ulist_free() when we exit from resolve_indirect_refs(). The static function free_leaf_list() is moved up for this to be possible and it's slightly simplified by removing unnecessary code. Fixes: 3301958b7c1d ("Btrfs: add inodes before dropping the extent lock in find_all_leafs") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: fix processing of delayed tree block refs during backref walkingFilipe Manana2022-10-291-6/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 943553ef9b51db303ab2b955c1025261abfdf6fb ] During backref walking, when processing a delayed reference with a type of BTRFS_TREE_BLOCK_REF_KEY, we have two bugs there: 1) We are accessing the delayed references extent_op, and its key, without the protection of the delayed ref head's lock; 2) If there's no extent op for the delayed ref head, we end up with an uninitialized key in the stack, variable 'tmp_op_key', and then pass it to add_indirect_ref(), which adds the reference to the indirect refs rb tree. This is wrong, because indirect references should have a NULL key when we don't have access to the key, and in that case they should be added to the indirect_missing_keys rb tree and not to the indirect rb tree. This means that if have BTRFS_TREE_BLOCK_REF_KEY delayed ref resulting from freeing an extent buffer, therefore with a count of -1, it will not cancel out the corresponding reference we have in the extent tree (with a count of 1), since both references end up in different rb trees. When using fiemap, where we often need to check if extents are shared through shared subtrees resulting from snapshots, it means we can incorrectly report an extent as shared when it's no longer shared. However this is temporary because after the transaction is committed the extent is no longer reported as shared, as running the delayed reference results in deleting the tree block reference from the extent tree. Outside the fiemap context, the result is unpredictable, as the key was not initialized but it's used when navigating the rb trees to insert and search for references (prelim_ref_compare()), and we expect all references in the indirect rb tree to have valid keys. The following reproducer triggers the second bug: $ cat test.sh #!/bin/bash DEV=/dev/sdj MNT=/mnt/sdj mkfs.btrfs -f $DEV mount -o compress $DEV $MNT # With a compressed 128M file we get a tree height of 2 (level 1 root). xfs_io -f -c "pwrite -b 1M 0 128M" $MNT/foo btrfs subvolume snapshot $MNT $MNT/snap # Fiemap should output 0x2008 in the flags column. # 0x2000 means shared extent # 0x8 means encoded extent (because it's compressed) echo echo "fiemap after snapshot, range [120M, 120M + 128K):" xfs_io -c "fiemap -v 120M 128K" $MNT/foo echo # Overwrite one extent and fsync to flush delalloc and COW a new path # in the snapshot's tree. # # After this we have a BTRFS_DROP_DELAYED_REF delayed ref of type # BTRFS_TREE_BLOCK_REF_KEY with a count of -1 for every COWed extent # buffer in the path. # # In the extent tree we have inline references of type # BTRFS_TREE_BLOCK_REF_KEY, with a count of 1, for the same extent # buffers, so they should cancel each other, and the extent buffers in # the fs tree should no longer be considered as shared. # echo "Overwriting file range [120M, 120M + 128K)..." xfs_io -c "pwrite -b 128K 120M 128K" $MNT/snap/foo xfs_io -c "fsync" $MNT/snap/foo # Fiemap should output 0x8 in the flags column. The extent in the range # [120M, 120M + 128K) is no longer shared, it's now exclusive to the fs # tree. echo echo "fiemap after overwrite range [120M, 120M + 128K):" xfs_io -c "fiemap -v 120M 128K" $MNT/foo echo umount $MNT Running it before this patch: $ ./test.sh (...) wrote 134217728/134217728 bytes at offset 0 128 MiB, 128 ops; 0.1152 sec (1.085 GiB/sec and 1110.5809 ops/sec) Create a snapshot of '/mnt/sdj' in '/mnt/sdj/snap' fiemap after snapshot, range [120M, 120M + 128K): /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [245760..246015]: 34304..34559 256 0x2008 Overwriting file range [120M, 120M + 128K)... wrote 131072/131072 bytes at offset 125829120 128 KiB, 1 ops; 0.0001 sec (683.060 MiB/sec and 5464.4809 ops/sec) fiemap after overwrite range [120M, 120M + 128K): /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [245760..246015]: 34304..34559 256 0x2008 The extent in the range [120M, 120M + 128K) is still reported as shared (0x2000 bit set) after overwriting that range and flushing delalloc, which is not correct - an entire path was COWed in the snapshot's tree and the extent is now only referenced by the original fs tree. Running it after this patch: $ ./test.sh (...) wrote 134217728/134217728 bytes at offset 0 128 MiB, 128 ops; 0.1198 sec (1.043 GiB/sec and 1068.2067 ops/sec) Create a snapshot of '/mnt/sdj' in '/mnt/sdj/snap' fiemap after snapshot, range [120M, 120M + 128K): /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [245760..246015]: 34304..34559 256 0x2008 Overwriting file range [120M, 120M + 128K)... wrote 131072/131072 bytes at offset 125829120 128 KiB, 1 ops; 0.0001 sec (694.444 MiB/sec and 5555.5556 ops/sec) fiemap after overwrite range [120M, 120M + 128K): /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [245760..246015]: 34304..34559 256 0x8 Now the extent is not reported as shared anymore. So fix this by passing a NULL key pointer to add_indirect_ref() when processing a delayed reference for a tree block if there's no extent op for our delayed ref head with a defined key. Also access the extent op only after locking the delayed ref head's lock. The reproducer will be converted later to a test case for fstests. Fixes: 86d5f994425252 ("btrfs: convert prelimary reference tracking to use rbtrees") Fixes: a6dbceafb915e8 ("btrfs: Remove unused op_key var from add_delayed_refs") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: fix processing of delayed data refs during backref walkingFilipe Manana2022-10-291-9/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 4fc7b57228243d09c0d878873bf24fa64a90fa01 ] When processing delayed data references during backref walking and we are using a share context (we are being called through fiemap), whenever we find a delayed data reference for an inode different from the one we are interested in, then we immediately exit and consider the data extent as shared. This is wrong, because: 1) This might be a DROP reference that will cancel out a reference in the extent tree; 2) Even if it's an ADD reference, it may be followed by a DROP reference that cancels it out. In either case we should not exit immediately. Fix this by never exiting when we find a delayed data reference for another inode - instead add the reference and if it does not cancel out other delayed reference, we will exit early when we call extent_is_shared() after processing all delayed references. If we find a drop reference, then signal the code that processes references from the extent tree (add_inline_refs() and add_keyed_refs()) to not exit immediately if it finds there a reference for another inode, since we have delayed drop references that may cancel it out. In this later case we exit once we don't have references in the rb trees that cancel out each other and have two references for different inodes. Example reproducer for case 1): $ cat test-1.sh #!/bin/bash DEV=/dev/sdj MNT=/mnt/sdj mkfs.btrfs -f $DEV mount $DEV $MNT xfs_io -f -c "pwrite 0 64K" $MNT/foo cp --reflink=always $MNT/foo $MNT/bar echo echo "fiemap after cloning:" xfs_io -c "fiemap -v" $MNT/foo rm -f $MNT/bar echo echo "fiemap after removing file bar:" xfs_io -c "fiemap -v" $MNT/foo umount $MNT Running it before this patch, the extent is still listed as shared, it has the flag 0x2000 (FIEMAP_EXTENT_SHARED) set: $ ./test-1.sh fiemap after cloning: /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 26624..26751 128 0x2001 fiemap after removing file bar: /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 26624..26751 128 0x2001 Example reproducer for case 2): $ cat test-2.sh #!/bin/bash DEV=/dev/sdj MNT=/mnt/sdj mkfs.btrfs -f $DEV mount $DEV $MNT xfs_io -f -c "pwrite 0 64K" $MNT/foo cp --reflink=always $MNT/foo $MNT/bar # Flush delayed references to the extent tree and commit current # transaction. sync echo echo "fiemap after cloning:" xfs_io -c "fiemap -v" $MNT/foo rm -f $MNT/bar echo echo "fiemap after removing file bar:" xfs_io -c "fiemap -v" $MNT/foo umount $MNT Running it before this patch, the extent is still listed as shared, it has the flag 0x2000 (FIEMAP_EXTENT_SHARED) set: $ ./test-2.sh fiemap after cloning: /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 26624..26751 128 0x2001 fiemap after removing file bar: /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 26624..26751 128 0x2001 After this patch, after deleting bar in both tests, the extent is not reported with the 0x2000 flag anymore, it gets only the flag 0x1 (which is FIEMAP_EXTENT_LAST): $ ./test-1.sh fiemap after cloning: /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 26624..26751 128 0x2001 fiemap after removing file bar: /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 26624..26751 128 0x1 $ ./test-2.sh fiemap after cloning: /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 26624..26751 128 0x2001 fiemap after removing file bar: /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 26624..26751 128 0x1 These tests will later be converted to a test case for fstests. Fixes: dc046b10c8b7d4 ("Btrfs: make fiemap not blow when you have lots of snapshots") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: enhance unsupported compat RO flags handlingQu Wenruo2022-10-292-1/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 81d5d61454c365718655cfc87d8200c84e25d596 upstream. Currently there are two corner cases not handling compat RO flags correctly: - Remount We can still mount the fs RO with compat RO flags, then remount it RW. We should not allow any write into a fs with unsupported RO flags. - Still try to search block group items In fact, behavior/on-disk format change to extent tree should not need a full incompat flag. And since we can ensure fs with unsupported RO flags never got any writes (with above case fixed), then we can even skip block group items search at mount time. This patch will enhance the unsupported RO compat flags by: - Reject read-write remount if there are unsupported RO compat flags - Go dummy block group items directly for unsupported RO compat flags In fact, only changes to chunk/subvolume/root/csum trees should go incompat flags. The latter part should allow future change to extent tree to be compat RO flags. Thus this patch also needs to be backported to all stable trees. CC: stable@vger.kernel.org # 4.9+ 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: don't print information about space cache or tree every remountMaciej S. Szmigiero2022-10-261-4/+7
| | | | | | | | | | | | | | | | | | | | [ Upstream commit dbecac26630014d336a8e5ea67096ff18210fb9c ] btrfs currently prints information about space cache or free space tree being in use on every remount, regardless whether such remount actually enabled or disabled one of these features. This is actually unnecessary since providing remount options changing the state of these features will explicitly print the appropriate notice. Let's instead print such unconditional information just on an initial mount to avoid filling the kernel log when, for example, laptop-mode-tools remount the fs on some events. Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: scrub: try to fix super block errorsQu Wenruo2022-10-261-0/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit f9eab5f0bba76742af654f33d517bf62a0db8f12 ] [BUG] The following script shows that, although scrub can detect super block errors, it never tries to fix it: mkfs.btrfs -f -d raid1 -m raid1 $dev1 $dev2 xfs_io -c "pwrite 67108864 4k" $dev2 mount $dev1 $mnt btrfs scrub start -B $dev2 btrfs scrub start -Br $dev2 umount $mnt The first scrub reports the super error correctly: scrub done for f3289218-abd3-41ac-a630-202f766c0859 Scrub started: Tue Aug 2 14:44:11 2022 Status: finished Duration: 0:00:00 Total to scrub: 1.26GiB Rate: 0.00B/s Error summary: super=1 Corrected: 0 Uncorrectable: 0 Unverified: 0 But the second read-only scrub still reports the same super error: Scrub started: Tue Aug 2 14:44:11 2022 Status: finished Duration: 0:00:00 Total to scrub: 1.26GiB Rate: 0.00B/s Error summary: super=1 Corrected: 0 Uncorrectable: 0 Unverified: 0 [CAUSE] The comments already shows that super block can be easily fixed by committing a transaction: /* * If we find an error in a super block, we just report it. * They will get written with the next transaction commit * anyway */ But the truth is, such assumption is not always true, and since scrub should try to repair every error it found (except for read-only scrub), we should really actively commit a transaction to fix this. [FIX] Just commit a transaction if we found any super block errors, after everything else is done. We cannot do this just after scrub_supers(), as btrfs_commit_transaction() will try to pause and wait for the running scrub, thus we can not call it with scrub_lock hold. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: dump extra info if one free space cache has more bitmaps than it shouldQu Wenruo2022-10-261-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 62cd9d4474282a1eb84f945955c56cbfc42e1ffe ] There is an internal report on hitting the following ASSERT() in recalculate_thresholds(): ASSERT(ctl->total_bitmaps <= max_bitmaps); Above @max_bitmaps is calculated using the following variables: - bytes_per_bg 8 * 4096 * 4096 (128M) for x86_64/x86. - block_group->length The length of the block group. @max_bitmaps is the rounded up value of block_group->length / 128M. Normally one free space cache should not have more bitmaps than above value, but when it happens the ASSERT() can be triggered if CONFIG_BTRFS_ASSERT is also enabled. But the ASSERT() itself won't provide enough info to know which is going wrong. Is the bg too small thus it only allows one bitmap? Or is there something else wrong? So although I haven't found extra reports or crash dump to do further investigation, add the extra info to make it more helpful to debug. 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
* btrfs: set generation before calling btrfs_clean_tree_block in ↵Tetsuo Handa2022-10-261-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | btrfs_init_new_buffer commit cbddcc4fa3443fe8cfb2ff8e210deb1f6a0eea38 upstream. syzbot is reporting uninit-value in btrfs_clean_tree_block() [1], for commit bc877d285ca3dba2 ("btrfs: Deduplicate extent_buffer init code") missed that btrfs_set_header_generation() in btrfs_init_new_buffer() must not be moved to after clean_tree_block() because clean_tree_block() is calling btrfs_header_generation() since commit 55c69072d6bd5be1 ("Btrfs: Fix extent_buffer usage when nodesize != leafsize"). Since memzero_extent_buffer() will reset "struct btrfs_header" part, we can't move btrfs_set_header_generation() to before memzero_extent_buffer(). Just re-add btrfs_set_header_generation() before btrfs_clean_tree_block(). Link: https://syzkaller.appspot.com/bug?extid=fba8e2116a12609b6c59 [1] Reported-by: syzbot <syzbot+fba8e2116a12609b6c59@syzkaller.appspotmail.com> Fixes: bc877d285ca3dba2 ("btrfs: Deduplicate extent_buffer init code") CC: stable@vger.kernel.org # 4.19+ Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: fix race between quota enable and quota rescan ioctlFilipe Manana2022-10-261-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 331cd9461412e103d07595a10289de90004ac890 upstream. When enabling quotas, at btrfs_quota_enable(), after committing the transaction, we change fs_info->quota_root to point to the quota root we created and set BTRFS_FS_QUOTA_ENABLED at fs_info->flags. Then we try to start the qgroup rescan worker, first by initializing it with a call to qgroup_rescan_init() - however if that fails we end up freeing the quota root but we leave fs_info->quota_root still pointing to it, this can later result in a use-after-free somewhere else. We have previously set the flags BTRFS_FS_QUOTA_ENABLED and BTRFS_QGROUP_STATUS_FLAG_ON, so we can only fail with -EINPROGRESS at btrfs_quota_enable(), which is possible if someone already called the quota rescan ioctl, and therefore started the rescan worker. So fix this by ignoring an -EINPROGRESS and asserting we can't get any other error. Reported-by: Ye Bin <yebin10@huawei.com> Link: https://lore.kernel.org/linux-btrfs/20220823015931.421355-1-yebin10@huawei.com/ CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: fix hang during unmount when stopping a space reclaim workerFilipe Manana2022-09-281-0/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit a362bb864b8db4861977d00bd2c3222503ccc34b upstream. Often when running generic/562 from fstests we can hang during unmount, resulting in a trace like this: Sep 07 11:52:00 debian9 unknown: run fstests generic/562 at 2022-09-07 11:52:00 Sep 07 11:55:32 debian9 kernel: INFO: task umount:49438 blocked for more than 120 seconds. Sep 07 11:55:32 debian9 kernel: Not tainted 6.0.0-rc2-btrfs-next-122 #1 Sep 07 11:55:32 debian9 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Sep 07 11:55:32 debian9 kernel: task:umount state:D stack: 0 pid:49438 ppid: 25683 flags:0x00004000 Sep 07 11:55:32 debian9 kernel: Call Trace: Sep 07 11:55:32 debian9 kernel: <TASK> Sep 07 11:55:32 debian9 kernel: __schedule+0x3c8/0xec0 Sep 07 11:55:32 debian9 kernel: ? rcu_read_lock_sched_held+0x12/0x70 Sep 07 11:55:32 debian9 kernel: schedule+0x5d/0xf0 Sep 07 11:55:32 debian9 kernel: schedule_timeout+0xf1/0x130 Sep 07 11:55:32 debian9 kernel: ? lock_release+0x224/0x4a0 Sep 07 11:55:32 debian9 kernel: ? lock_acquired+0x1a0/0x420 Sep 07 11:55:32 debian9 kernel: ? trace_hardirqs_on+0x2c/0xd0 Sep 07 11:55:32 debian9 kernel: __wait_for_common+0xac/0x200 Sep 07 11:55:32 debian9 kernel: ? usleep_range_state+0xb0/0xb0 Sep 07 11:55:32 debian9 kernel: __flush_work+0x26d/0x530 Sep 07 11:55:32 debian9 kernel: ? flush_workqueue_prep_pwqs+0x140/0x140 Sep 07 11:55:32 debian9 kernel: ? trace_clock_local+0xc/0x30 Sep 07 11:55:32 debian9 kernel: __cancel_work_timer+0x11f/0x1b0 Sep 07 11:55:32 debian9 kernel: ? close_ctree+0x12b/0x5b3 [btrfs] Sep 07 11:55:32 debian9 kernel: ? __trace_bputs+0x10b/0x170 Sep 07 11:55:32 debian9 kernel: close_ctree+0x152/0x5b3 [btrfs] Sep 07 11:55:32 debian9 kernel: ? evict_inodes+0x166/0x1c0 Sep 07 11:55:32 debian9 kernel: generic_shutdown_super+0x71/0x120 Sep 07 11:55:32 debian9 kernel: kill_anon_super+0x14/0x30 Sep 07 11:55:32 debian9 kernel: btrfs_kill_super+0x12/0x20 [btrfs] Sep 07 11:55:32 debian9 kernel: deactivate_locked_super+0x2e/0xa0 Sep 07 11:55:32 debian9 kernel: cleanup_mnt+0x100/0x160 Sep 07 11:55:32 debian9 kernel: task_work_run+0x59/0xa0 Sep 07 11:55:32 debian9 kernel: exit_to_user_mode_prepare+0x1a6/0x1b0 Sep 07 11:55:32 debian9 kernel: syscall_exit_to_user_mode+0x16/0x40 Sep 07 11:55:32 debian9 kernel: do_syscall_64+0x48/0x90 Sep 07 11:55:32 debian9 kernel: entry_SYSCALL_64_after_hwframe+0x63/0xcd Sep 07 11:55:32 debian9 kernel: RIP: 0033:0x7fcde59a57a7 Sep 07 11:55:32 debian9 kernel: RSP: 002b:00007ffe914217c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 Sep 07 11:55:32 debian9 kernel: RAX: 0000000000000000 RBX: 00007fcde5ae8264 RCX: 00007fcde59a57a7 Sep 07 11:55:32 debian9 kernel: RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000055b57556cdd0 Sep 07 11:55:32 debian9 kernel: RBP: 000055b57556cba0 R08: 0000000000000000 R09: 00007ffe91420570 Sep 07 11:55:32 debian9 kernel: R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 Sep 07 11:55:32 debian9 kernel: R13: 000055b57556cdd0 R14: 000055b57556ccb8 R15: 0000000000000000 Sep 07 11:55:32 debian9 kernel: </TASK> What happens is the following: 1) The cleaner kthread tries to start a transaction to delete an unused block group, but the metadata reservation can not be satisfied right away, so a reservation ticket is created and it starts the async metadata reclaim task (fs_info->async_reclaim_work); 2) Writeback for all the filler inodes with an i_size of 2K starts (generic/562 creates a lot of 2K files with the goal of filling metadata space). We try to create an inline extent for them, but we fail when trying to insert the inline extent with -ENOSPC (at cow_file_range_inline()) - since this is not critical, we fallback to non-inline mode (back to cow_file_range()), reserve extents, create extent maps and create the ordered extents; 3) An unmount starts, enters close_ctree(); 4) The async reclaim task is flushing stuff, entering the flush states one by one, until it reaches RUN_DELAYED_IPUTS. There it runs all current delayed iputs. After running the delayed iputs and before calling btrfs_wait_on_delayed_iputs(), one or more ordered extents complete, and btrfs_add_delayed_iput() is called for each one through btrfs_finish_ordered_io() -> btrfs_put_ordered_extent(). This results in bumping fs_info->nr_delayed_iputs from 0 to some positive value. So the async reclaim task blocks at btrfs_wait_on_delayed_iputs() waiting for fs_info->nr_delayed_iputs to become 0; 5) The current transaction is committed by the transaction kthread, we then start unpinning extents and end up calling btrfs_try_granting_tickets() through unpin_extent_range(), since we released some space. This results in satisfying the ticket created by the cleaner kthread at step 1, waking up the cleaner kthread; 6) At close_ctree() we ask the cleaner kthread to park; 7) The cleaner kthread starts the transaction, deletes the unused block group, and then calls kthread_should_park(), which returns true, so it parks. And at this point we have the delayed iputs added by the completion of the ordered extents still pending; 8) Then later at close_ctree(), when we call: cancel_work_sync(&fs_info->async_reclaim_work); We hang forever, since the cleaner was parked and no one else can run delayed iputs after that, while the reclaim task is waiting for the remaining delayed iputs to be completed. Fix this by waiting for all ordered extents to complete and running the delayed iputs before attempting to stop the async reclaim tasks. Note that we can not wait for ordered extents with btrfs_wait_ordered_roots() (or other similar functions) because that waits for the BTRFS_ORDERED_COMPLETE flag to be set on an ordered extent, but the delayed iput is added after that, when doing the final btrfs_put_ordered_extent(). So instead wait for the work queues used for executing ordered extent completion to be empty, which works because we do the final put on an ordered extent at btrfs_finish_ordered_io() (while we are in the unmount context). Fixes: d6fd0ae25c6495 ("Btrfs: fix missing delayed iputs on unmount") CC: stable@vger.kernel.org # 5.15+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: fix hang during unmount when stopping block group reclaim workerFilipe Manana2022-09-281-6/+11
| | | | | | | | | | | | | | | | | | | | | | | | commit 8a1f1e3d1eecf9d2359a2709e276743a67e145db upstream. During early unmount, at close_ctree(), we try to stop the block group reclaim task with cancel_work_sync(), but that may hang if the block group reclaim task is currently at btrfs_relocate_block_group() waiting for the flag BTRFS_FS_UNFINISHED_DROPS to be cleared from fs_info->flags. During unmount we only clear that flag later, after trying to stop the block group reclaim task. Fix that by clearing BTRFS_FS_UNFINISHED_DROPS before trying to stop the block group reclaim task and after setting BTRFS_FS_CLOSING_START, so that if the reclaim task is waiting on that bit, it will stop immediately after being woken, because it sees the filesystem is closing (with a call to btrfs_fs_closing()), and then returns immediately with -EINTR. Fixes: 31e70e527806c5 ("btrfs: fix hang during unmount when block group reclaim task is running") CC: stable@vger.kernel.org # 5.15+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* btrfs: zoned: set pseudo max append zone limit in zone emulation modeShin'ichiro Kawasaki2022-09-151-3/+12
| | | | | | | | | | | | | | | | | | | | | | | | | commit cac5c44c48c9fb9cc31bea15ebd9ef0c6462314f upstream. The commit 7d7672bc5d10 ("btrfs: convert count_max_extents() to use fs_info->max_extent_size") introduced a division by fs_info->max_extent_size. This max_extent_size is initialized with max zone append limit size of the device btrfs runs on. However, in zone emulation mode, the device is not zoned then its zone append limit is zero. This resulted in zero value of fs_info->max_extent_size and caused zero division error. Fix the error by setting non-zero pseudo value to max append zone limit in zone emulation mode. Set the pseudo value based on max_segments as suggested in the commit c2ae7b772ef4 ("btrfs: zoned: revive max_zone_append_bytes"). Fixes: 7d7672bc5d10 ("btrfs: convert count_max_extents() to use fs_info->max_extent_size") CC: stable@vger.kernel.org # 5.12+ Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>