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2024-01-08btrfs: do not allow non subvolume root targets for snapshotJosef Bacik
[ Upstream commit a8892fd71933126ebae3d60aec5918d4dceaae76 ] Our btrfs subvolume snapshot <source> <destination> utility enforces that <source> is the root of the subvolume, however this isn't enforced in the kernel. Update the kernel to also enforce this limitation to avoid problems with other users of this ioctl that don't have the appropriate checks in place. Reported-by: Martin Michaelis <code@mgjm.de> CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Neal Gompa <neal@gompa.dev> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-12-08btrfs: send: ensure send_fd is writableJann Horn
commit 0ac1d13a55eb37d398b63e6ff6db4a09a2c9128c upstream. kernel_write() requires the caller to ensure that the file is writable. Let's do that directly after looking up the ->send_fd. We don't need a separate bailout path because the "out" path already does fput() if ->send_filp is non-NULL. This has no security impact for two reasons: - the ioctl requires CAP_SYS_ADMIN - __kernel_write() bails out on read-only files - but only since 5.8, see commit a01ac27be472 ("fs: check FMODE_WRITE in __kernel_write") Reported-and-tested-by: syzbot+12e098239d20385264d3@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=12e098239d20385264d3 Fixes: 31db9f7c23fb ("Btrfs: introduce BTRFS_IOC_SEND for btrfs send/receive") CC: stable@vger.kernel.org # 4.14+ Signed-off-by: Jann Horn <jannh@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>
2023-12-08btrfs: fix off-by-one when checking chunk map includes logical addressFilipe Manana
commit 5fba5a571858ce2d787fdaf55814e42725bfa895 upstream. At btrfs_get_chunk_map() we get the extent map for the chunk that contains the given logical address stored in the 'logical' argument. Then we do sanity checks to verify the extent map contains the logical address. One of these checks verifies if the extent map covers a range with an end offset behind the target logical address - however this check has an off-by-one error since it will consider an extent map whose start offset plus its length matches the target logical address as inclusive, while the fact is that the last byte it covers is behind the target logical address (by 1). So fix this condition by using '<=' rather than '<' when comparing the extent map's "start + length" against the target logical address. CC: stable@vger.kernel.org # 4.14+ 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>
2023-11-20btrfs: use u64 for buffer sizes in the tree search ioctlsFilipe Manana
[ Upstream commit dec96fc2dcb59723e041416b8dc53e011b4bfc2e ] In the tree search v2 ioctl we use the type size_t, which is an unsigned long, to track the buffer size in the local variable 'buf_size'. An unsigned long is 32 bits wide on a 32 bits architecture. The buffer size defined in struct btrfs_ioctl_search_args_v2 is a u64, so when we later try to copy the local variable 'buf_size' to the argument struct, when the search returns -EOVERFLOW, we copy only 32 bits which will be a problem on big endian systems. Fix this by using a u64 type for the buffer sizes, not only at btrfs_ioctl_tree_search_v2(), but also everywhere down the call chain so that we can use the u64 at btrfs_ioctl_tree_search_v2(). Fixes: cc68a8a5a433 ("btrfs: new ioctl TREE_SEARCH_V2") Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Link: https://lore.kernel.org/linux-btrfs/ce6f4bd6-9453-4ffe-ba00-cee35495e10f@moroto.mountain/ 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: Sasha Levin <sashal@kernel.org>
2023-10-25btrfs: fix some -Wmaybe-uninitialized warnings in ioctl.cJosef Bacik
[ Upstream commit 9147b9ded499d9853bdf0e9804b7eaa99c4429ed ] Jens reported the following warnings from -Wmaybe-uninitialized recent Linus' branch. In file included from ./include/asm-generic/rwonce.h:26, from ./arch/arm64/include/asm/rwonce.h:71, from ./include/linux/compiler.h:246, from ./include/linux/export.h:5, from ./include/linux/linkage.h:7, from ./include/linux/kernel.h:17, from fs/btrfs/ioctl.c:6: In function ‘instrument_copy_from_user_before’, inlined from ‘_copy_from_user’ at ./include/linux/uaccess.h:148:3, inlined from ‘copy_from_user’ at ./include/linux/uaccess.h:183:7, inlined from ‘btrfs_ioctl_space_info’ at fs/btrfs/ioctl.c:2999:6, inlined from ‘btrfs_ioctl’ at fs/btrfs/ioctl.c:4616:10: ./include/linux/kasan-checks.h:38:27: warning: ‘space_args’ may be used uninitialized [-Wmaybe-uninitialized] 38 | #define kasan_check_write __kasan_check_write ./include/linux/instrumented.h:129:9: note: in expansion of macro ‘kasan_check_write’ 129 | kasan_check_write(to, n); | ^~~~~~~~~~~~~~~~~ ./include/linux/kasan-checks.h: In function ‘btrfs_ioctl’: ./include/linux/kasan-checks.h:20:6: note: by argument 1 of type ‘const volatile void *’ to ‘__kasan_check_write’ declared here 20 | bool __kasan_check_write(const volatile void *p, unsigned int size); | ^~~~~~~~~~~~~~~~~~~ fs/btrfs/ioctl.c:2981:39: note: ‘space_args’ declared here 2981 | struct btrfs_ioctl_space_args space_args; | ^~~~~~~~~~ In function ‘instrument_copy_from_user_before’, inlined from ‘_copy_from_user’ at ./include/linux/uaccess.h:148:3, inlined from ‘copy_from_user’ at ./include/linux/uaccess.h:183:7, inlined from ‘_btrfs_ioctl_send’ at fs/btrfs/ioctl.c:4343:9, inlined from ‘btrfs_ioctl’ at fs/btrfs/ioctl.c:4658:10: ./include/linux/kasan-checks.h:38:27: warning: ‘args32’ may be used uninitialized [-Wmaybe-uninitialized] 38 | #define kasan_check_write __kasan_check_write ./include/linux/instrumented.h:129:9: note: in expansion of macro ‘kasan_check_write’ 129 | kasan_check_write(to, n); | ^~~~~~~~~~~~~~~~~ ./include/linux/kasan-checks.h: In function ‘btrfs_ioctl’: ./include/linux/kasan-checks.h:20:6: note: by argument 1 of type ‘const volatile void *’ to ‘__kasan_check_write’ declared here 20 | bool __kasan_check_write(const volatile void *p, unsigned int size); | ^~~~~~~~~~~~~~~~~~~ fs/btrfs/ioctl.c:4341:49: note: ‘args32’ declared here 4341 | struct btrfs_ioctl_send_args_32 args32; | ^~~~~~ This was due to his config options and having KASAN turned on, which adds some extra checks around copy_from_user(), which then triggered the -Wmaybe-uninitialized checker for these cases. Fix the warnings by initializing the different structs we're copying into. Reported-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-10-25btrfs: initialize start_slot in btrfs_log_prealloc_extentsJosef Bacik
[ Upstream commit b4c639f699349880b7918b861e1bd360442ec450 ] Jens reported a compiler warning when using CONFIG_CC_OPTIMIZE_FOR_SIZE=y that looks like this fs/btrfs/tree-log.c: In function ‘btrfs_log_prealloc_extents’: fs/btrfs/tree-log.c:4828:23: warning: ‘start_slot’ may be used uninitialized [-Wmaybe-uninitialized] 4828 | ret = copy_items(trans, inode, dst_path, path, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 4829 | start_slot, ins_nr, 1, 0); | ~~~~~~~~~~~~~~~~~~~~~~~~~ fs/btrfs/tree-log.c:4725:13: note: ‘start_slot’ was declared here 4725 | int start_slot; | ^~~~~~~~~~ The compiler is incorrect, as we only use this code when ins_len > 0, and when ins_len > 0 we have start_slot properly initialized. However we generally find the -Wmaybe-uninitialized warnings valuable, so initialize start_slot to get rid of the warning. Reported-by: Jens Axboe <axboe@kernel.dk> Tested-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-10-25btrfs: return -EUCLEAN for delayed tree ref with a ref count not equals to 1Filipe Manana
[ Upstream commit 1bf76df3fee56d6637718e267f7c34ed70d0c7dc ] When running a delayed tree reference, if we find a ref count different from 1, we return -EIO. This isn't an IO error, as it indicates either a bug in the delayed refs code or a memory corruption, so change the error code from -EIO to -EUCLEAN. Also tag the branch as 'unlikely' as this is not expected to ever happen, and change the error message to print the tree block's bytenr without the parenthesis (and there was a missing space between the 'block' word and the opening parenthesis), for consistency as that's the style we used everywhere else. 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: Sasha Levin <sashal@kernel.org>
2023-10-10btrfs: properly report 0 avail for very full file systemsJosef Bacik
commit 58bfe2ccec5f9f137b41dd38f335290dcc13cd5c upstream. A user reported some issues with smaller file systems that get very full. While investigating this issue I noticed that df wasn't showing 100% full, despite having 0 chunk space and having < 1MiB of available metadata space. This turns out to be an overflow issue, we're doing: total_available_metadata_space - SZ_4M < global_block_rsv_size to determine if there's not enough space to make metadata allocations, which overflows if total_available_metadata_space is < 4M. Fix this by checking to see if our available space is greater than the 4M threshold. This makes df properly report 100% usage on the file system. CC: stable@vger.kernel.org # 4.14+ 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>
2023-09-23btrfs: fix lockdep splat and potential deadlock after failure running ↵Filipe Manana
delayed items commit e110f8911ddb93e6f55da14ccbbe705397b30d0b upstream. When running delayed items we are holding a delayed node's mutex and then we will attempt to modify a subvolume btree to insert/update/delete the delayed items. However if have an error during the insertions for example, btrfs_insert_delayed_items() may return with a path that has locked extent buffers (a leaf at the very least), and then we attempt to release the delayed node at __btrfs_run_delayed_items(), which requires taking the delayed node's mutex, causing an ABBA type of deadlock. This was reported by syzbot and the lockdep splat is the following: WARNING: possible circular locking dependency detected 6.5.0-rc7-syzkaller-00024-g93f5de5f648d #0 Not tainted ------------------------------------------------------ syz-executor.2/13257 is trying to acquire lock: ffff88801835c0c0 (&delayed_node->mutex){+.+.}-{3:3}, at: __btrfs_release_delayed_node+0x9a/0xaa0 fs/btrfs/delayed-inode.c:256 but task is already holding lock: ffff88802a5ab8e8 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_lock+0x3c/0x2a0 fs/btrfs/locking.c:198 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (btrfs-tree-00){++++}-{3:3}: __lock_release kernel/locking/lockdep.c:5475 [inline] lock_release+0x36f/0x9d0 kernel/locking/lockdep.c:5781 up_write+0x79/0x580 kernel/locking/rwsem.c:1625 btrfs_tree_unlock_rw fs/btrfs/locking.h:189 [inline] btrfs_unlock_up_safe+0x179/0x3b0 fs/btrfs/locking.c:239 search_leaf fs/btrfs/ctree.c:1986 [inline] btrfs_search_slot+0x2511/0x2f80 fs/btrfs/ctree.c:2230 btrfs_insert_empty_items+0x9c/0x180 fs/btrfs/ctree.c:4376 btrfs_insert_delayed_item fs/btrfs/delayed-inode.c:746 [inline] btrfs_insert_delayed_items fs/btrfs/delayed-inode.c:824 [inline] __btrfs_commit_inode_delayed_items+0xd24/0x2410 fs/btrfs/delayed-inode.c:1111 __btrfs_run_delayed_items+0x1db/0x430 fs/btrfs/delayed-inode.c:1153 flush_space+0x269/0xe70 fs/btrfs/space-info.c:723 btrfs_async_reclaim_metadata_space+0x106/0x350 fs/btrfs/space-info.c:1078 process_one_work+0x92c/0x12c0 kernel/workqueue.c:2600 worker_thread+0xa63/0x1210 kernel/workqueue.c:2751 kthread+0x2b8/0x350 kernel/kthread.c:389 ret_from_fork+0x2e/0x60 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 -> #0 (&delayed_node->mutex){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3142 [inline] check_prevs_add kernel/locking/lockdep.c:3261 [inline] validate_chain kernel/locking/lockdep.c:3876 [inline] __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5144 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5761 __mutex_lock_common+0x1d8/0x2530 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x1b/0x20 kernel/locking/mutex.c:799 __btrfs_release_delayed_node+0x9a/0xaa0 fs/btrfs/delayed-inode.c:256 btrfs_release_delayed_node fs/btrfs/delayed-inode.c:281 [inline] __btrfs_run_delayed_items+0x2b5/0x430 fs/btrfs/delayed-inode.c:1156 btrfs_commit_transaction+0x859/0x2ff0 fs/btrfs/transaction.c:2276 btrfs_sync_file+0xf56/0x1330 fs/btrfs/file.c:1988 vfs_fsync_range fs/sync.c:188 [inline] vfs_fsync fs/sync.c:202 [inline] do_fsync fs/sync.c:212 [inline] __do_sys_fsync fs/sync.c:220 [inline] __se_sys_fsync fs/sync.c:218 [inline] __x64_sys_fsync+0x196/0x1e0 fs/sync.c:218 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(btrfs-tree-00); lock(&delayed_node->mutex); lock(btrfs-tree-00); lock(&delayed_node->mutex); *** DEADLOCK *** 3 locks held by syz-executor.2/13257: #0: ffff88802c1ee370 (btrfs_trans_num_writers){++++}-{0:0}, at: spin_unlock include/linux/spinlock.h:391 [inline] #0: ffff88802c1ee370 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0xb87/0xe00 fs/btrfs/transaction.c:287 #1: ffff88802c1ee398 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0xbb2/0xe00 fs/btrfs/transaction.c:288 #2: ffff88802a5ab8e8 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_lock+0x3c/0x2a0 fs/btrfs/locking.c:198 stack backtrace: CPU: 0 PID: 13257 Comm: syz-executor.2 Not tainted 6.5.0-rc7-syzkaller-00024-g93f5de5f648d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 check_noncircular+0x375/0x4a0 kernel/locking/lockdep.c:2195 check_prev_add kernel/locking/lockdep.c:3142 [inline] check_prevs_add kernel/locking/lockdep.c:3261 [inline] validate_chain kernel/locking/lockdep.c:3876 [inline] __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5144 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5761 __mutex_lock_common+0x1d8/0x2530 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x1b/0x20 kernel/locking/mutex.c:799 __btrfs_release_delayed_node+0x9a/0xaa0 fs/btrfs/delayed-inode.c:256 btrfs_release_delayed_node fs/btrfs/delayed-inode.c:281 [inline] __btrfs_run_delayed_items+0x2b5/0x430 fs/btrfs/delayed-inode.c:1156 btrfs_commit_transaction+0x859/0x2ff0 fs/btrfs/transaction.c:2276 btrfs_sync_file+0xf56/0x1330 fs/btrfs/file.c:1988 vfs_fsync_range fs/sync.c:188 [inline] vfs_fsync fs/sync.c:202 [inline] do_fsync fs/sync.c:212 [inline] __do_sys_fsync fs/sync.c:220 [inline] __se_sys_fsync fs/sync.c:218 [inline] __x64_sys_fsync+0x196/0x1e0 fs/sync.c:218 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f3ad047cae9 Code: 28 00 00 00 75 (...) RSP: 002b:00007f3ad12510c8 EFLAGS: 00000246 ORIG_RAX: 000000000000004a RAX: ffffffffffffffda RBX: 00007f3ad059bf80 RCX: 00007f3ad047cae9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007f3ad04c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f3ad059bf80 R15: 00007ffe56af92f8 </TASK> ------------[ cut here ]------------ Fix this by releasing the path before releasing the delayed node in the error path at __btrfs_run_delayed_items(). Reported-by: syzbot+a379155f07c134ea9879@syzkaller.appspotmail.com Link: https://lore.kernel.org/linux-btrfs/000000000000abba27060403b5bd@google.com/ CC: stable@vger.kernel.org # 4.14+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-09-23btrfs: output extra debug info if we failed to find an inline backrefQu Wenruo
[ Upstream commit 7f72f50547b7af4ddf985b07fc56600a4deba281 ] [BUG] Syzbot reported several warning triggered inside lookup_inline_extent_backref(). [CAUSE] As usual, the reproducer doesn't reliably trigger locally here, but at least we know the WARN_ON() is triggered when an inline backref can not be found, and it can only be triggered when @insert is true. (I.e. inserting a new inline backref, which means the backref should already exist) [ENHANCEMENT] After the WARN_ON(), dump all the parameters and the extent tree leaf to help debug. Link: https://syzkaller.appspot.com/bug?extid=d6f9ff86c1d804ba2bc6 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>
2023-09-23btrfs: don't start transaction when joining with TRANS_JOIN_NOSTARTFilipe Manana
commit 4490e803e1fe9fab8db5025e44e23b55df54078b upstream. When joining a transaction with TRANS_JOIN_NOSTART, if we don't find a running transaction we end up creating one. This goes against the purpose of TRANS_JOIN_NOSTART which is to join a running transaction if its state is at or below the state TRANS_STATE_COMMIT_START, otherwise return an -ENOENT error and don't start a new transaction. So fix this to not create a new transaction if there's no running transaction at or below that state. CC: stable@vger.kernel.org # 4.14+ Fixes: a6d155d2e363 ("Btrfs: fix deadlock between fiemap and transaction commits") 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>
2023-08-30btrfs: fix BUG_ON condition in btrfs_cancel_balancexiaoshoukui
commit 29eefa6d0d07e185f7bfe9576f91e6dba98189c2 upstream. Pausing and canceling balance can race to interrupt balance lead to BUG_ON panic in btrfs_cancel_balance. The BUG_ON condition in btrfs_cancel_balance does not take this race scenario into account. However, the race condition has no other side effects. We can fix that. Reproducing it with panic trace like this: kernel BUG at fs/btrfs/volumes.c:4618! RIP: 0010:btrfs_cancel_balance+0x5cf/0x6a0 Call Trace: <TASK> ? do_nanosleep+0x60/0x120 ? hrtimer_nanosleep+0xb7/0x1a0 ? sched_core_clone_cookie+0x70/0x70 btrfs_ioctl_balance_ctl+0x55/0x70 btrfs_ioctl+0xa46/0xd20 __x64_sys_ioctl+0x7d/0xa0 do_syscall_64+0x38/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Race scenario as follows: > mutex_unlock(&fs_info->balance_mutex); > -------------------- > .......issue pause and cancel req in another thread > -------------------- > ret = __btrfs_balance(fs_info); > > mutex_lock(&fs_info->balance_mutex); > if (ret == -ECANCELED && atomic_read(&fs_info->balance_pause_req)) { > btrfs_info(fs_info, "balance: paused"); > btrfs_exclop_balance(fs_info, BTRFS_EXCLOP_BALANCE_PAUSED); > } CC: stable@vger.kernel.org # 4.19+ Signed-off-by: xiaoshoukui <xiaoshoukui@ruijie.com.cn> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-16btrfs: don't stop integrity writeback too earlyChristoph Hellwig
commit effa24f689ce0948f68c754991a445a8d697d3a8 upstream. extent_write_cache_pages stops writing pages as soon as nr_to_write hits zero. That is the right thing for opportunistic writeback, but incorrect for data integrity writeback, which needs to ensure that no dirty pages are left in the range. Thus only stop the writeback for WB_SYNC_NONE if nr_to_write hits 0. This is a port of write_cache_pages changes in commit 05fe478dd04e ("mm: write_cache_pages integrity fix"). Note that I've only trigger the problem with other changes to the btrfs writeback code, but this condition seems worthwhile fixing anyway. CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> [ updated comment ] Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-11btrfs: check for commit error at btrfs_attach_transaction_barrier()Filipe Manana
commit b28ff3a7d7e97456fd86b68d24caa32e1cfa7064 upstream. btrfs_attach_transaction_barrier() is used to get a handle pointing to the current running transaction if the transaction has not started its commit yet (its state is < TRANS_STATE_COMMIT_START). If the transaction commit has started, then we wait for the transaction to commit and finish before returning - however we completely ignore if the transaction was aborted due to some error during its commit, we simply return ERR_PT(-ENOENT), which makes the caller assume everything is fine and no errors happened. This could make an fsync return success (0) to user space when in fact we had a transaction abort and the target inode changes were therefore not persisted. Fix this by checking for the return value from btrfs_wait_for_commit(), and if it returned an error, return it back to the caller. Fixes: d4edf39bd5db ("Btrfs: fix uncompleted transaction") CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Qu Wenruo <wqu@suse.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>
2023-08-11btrfs: fix extent buffer leak after tree mod log failure at split_node()Filipe Manana
[ Upstream commit ede600e497b1461d06d22a7d17703d9096868bc3 ] At split_node(), if we fail to log the tree mod log copy operation, we return without unlocking the split extent buffer we just allocated and without decrementing the reference we own on it. Fix this by unlocking it and decrementing the ref count before returning. Fixes: 5de865eebb83 ("Btrfs: fix tree mod logging") CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Qu Wenruo <wqu@suse.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: Sasha Levin <sashal@kernel.org>
2023-08-11btrfs: fix race when deleting quota root from the dirty cow roots listFilipe Manana
commit b31cb5a6eb7a48b0a7bfdf06832b1fd5088d8c79 upstream. When disabling quotas we are deleting the quota root from the list fs_info->dirty_cowonly_roots without taking the lock that protects it, which is struct btrfs_fs_info::trans_lock. This unsynchronized list manipulation may cause chaos if there's another concurrent manipulation of this list, such as when adding a root to it with ctree.c:add_root_to_dirty_list(). This can result in all sorts of weird failures caused by a race, such as the following crash: [337571.278245] general protection fault, probably for non-canonical address 0xdead000000000108: 0000 [#1] PREEMPT SMP PTI [337571.278933] CPU: 1 PID: 115447 Comm: btrfs Tainted: G W 6.4.0-rc6-btrfs-next-134+ #1 [337571.279153] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [337571.279572] RIP: 0010:commit_cowonly_roots+0x11f/0x250 [btrfs] [337571.279928] Code: 85 38 06 00 (...) [337571.280363] RSP: 0018:ffff9f63446efba0 EFLAGS: 00010206 [337571.280582] RAX: ffff942d98ec2638 RBX: ffff9430b82b4c30 RCX: 0000000449e1c000 [337571.280798] RDX: dead000000000100 RSI: ffff9430021e4900 RDI: 0000000000036070 [337571.281015] RBP: ffff942d98ec2000 R08: ffff942d98ec2000 R09: 000000000000015b [337571.281254] R10: 0000000000000009 R11: 0000000000000001 R12: ffff942fe8fbf600 [337571.281476] R13: ffff942dabe23040 R14: ffff942dabe20800 R15: ffff942d92cf3b48 [337571.281723] FS: 00007f478adb7340(0000) GS:ffff94349fa40000(0000) knlGS:0000000000000000 [337571.281950] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [337571.282184] CR2: 00007f478ab9a3d5 CR3: 000000001e02c001 CR4: 0000000000370ee0 [337571.282416] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [337571.282647] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [337571.282874] Call Trace: [337571.283101] <TASK> [337571.283327] ? __die_body+0x1b/0x60 [337571.283570] ? die_addr+0x39/0x60 [337571.283796] ? exc_general_protection+0x22e/0x430 [337571.284022] ? asm_exc_general_protection+0x22/0x30 [337571.284251] ? commit_cowonly_roots+0x11f/0x250 [btrfs] [337571.284531] btrfs_commit_transaction+0x42e/0xf90 [btrfs] [337571.284803] ? _raw_spin_unlock+0x15/0x30 [337571.285031] ? release_extent_buffer+0x103/0x130 [btrfs] [337571.285305] reset_balance_state+0x152/0x1b0 [btrfs] [337571.285578] btrfs_balance+0xa50/0x11e0 [btrfs] [337571.285864] ? __kmem_cache_alloc_node+0x14a/0x410 [337571.286086] btrfs_ioctl+0x249a/0x3320 [btrfs] [337571.286358] ? mod_objcg_state+0xd2/0x360 [337571.286577] ? refill_obj_stock+0xb0/0x160 [337571.286798] ? seq_release+0x25/0x30 [337571.287016] ? __rseq_handle_notify_resume+0x3ba/0x4b0 [337571.287235] ? percpu_counter_add_batch+0x2e/0xa0 [337571.287455] ? __x64_sys_ioctl+0x88/0xc0 [337571.287675] __x64_sys_ioctl+0x88/0xc0 [337571.287901] do_syscall_64+0x38/0x90 [337571.288126] entry_SYSCALL_64_after_hwframe+0x72/0xdc [337571.288352] RIP: 0033:0x7f478aaffe9b So fix this by locking struct btrfs_fs_info::trans_lock before deleting the quota root from that list. Fixes: bed92eae26cc ("Btrfs: qgroup implementation and prototypes") CC: stable@vger.kernel.org # 4.14+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-14btrfs: unset reloc control if transaction commit fails in prepare_to_relocate()Zixuan Fu
commit 85f02d6c856b9f3a0acf5219de6e32f58b9778eb upstream. In btrfs_relocate_block_group(), the rc is allocated. Then btrfs_relocate_block_group() calls relocate_block_group() prepare_to_relocate() set_reloc_control() that assigns rc to the variable fs_info->reloc_ctl. When prepare_to_relocate() returns, it calls btrfs_commit_transaction() btrfs_start_dirty_block_groups() btrfs_alloc_path() kmem_cache_zalloc() which may fail for example (or other errors could happen). When the failure occurs, btrfs_relocate_block_group() detects the error and frees rc and doesn't set fs_info->reloc_ctl to NULL. After that, in btrfs_init_reloc_root(), rc is retrieved from fs_info->reloc_ctl and then used, which may cause a use-after-free bug. This possible bug can be triggered by calling btrfs_ioctl_balance() before calling btrfs_ioctl_defrag(). To fix this possible bug, in prepare_to_relocate(), check if btrfs_commit_transaction() fails. If the failure occurs, unset_reloc_control() is called to set fs_info->reloc_ctl to NULL. The error log in our fault-injection testing is shown as follows: [ 58.751070] BUG: KASAN: use-after-free in btrfs_init_reloc_root+0x7ca/0x920 [btrfs] ... [ 58.753577] Call Trace: ... [ 58.755800] kasan_report+0x45/0x60 [ 58.756066] btrfs_init_reloc_root+0x7ca/0x920 [btrfs] [ 58.757304] record_root_in_trans+0x792/0xa10 [btrfs] [ 58.757748] btrfs_record_root_in_trans+0x463/0x4f0 [btrfs] [ 58.758231] start_transaction+0x896/0x2950 [btrfs] [ 58.758661] btrfs_defrag_root+0x250/0xc00 [btrfs] [ 58.759083] btrfs_ioctl_defrag+0x467/0xa00 [btrfs] [ 58.759513] btrfs_ioctl+0x3c95/0x114e0 [btrfs] ... [ 58.768510] Allocated by task 23683: [ 58.768777] ____kasan_kmalloc+0xb5/0xf0 [ 58.769069] __kmalloc+0x227/0x3d0 [ 58.769325] alloc_reloc_control+0x10a/0x3d0 [btrfs] [ 58.769755] btrfs_relocate_block_group+0x7aa/0x1e20 [btrfs] [ 58.770228] btrfs_relocate_chunk+0xf1/0x760 [btrfs] [ 58.770655] __btrfs_balance+0x1326/0x1f10 [btrfs] [ 58.771071] btrfs_balance+0x3150/0x3d30 [btrfs] [ 58.771472] btrfs_ioctl_balance+0xd84/0x1410 [btrfs] [ 58.771902] btrfs_ioctl+0x4caa/0x114e0 [btrfs] ... [ 58.773337] Freed by task 23683: ... [ 58.774815] kfree+0xda/0x2b0 [ 58.775038] free_reloc_control+0x1d6/0x220 [btrfs] [ 58.775465] btrfs_relocate_block_group+0x115c/0x1e20 [btrfs] [ 58.775944] btrfs_relocate_chunk+0xf1/0x760 [btrfs] [ 58.776369] __btrfs_balance+0x1326/0x1f10 [btrfs] [ 58.776784] btrfs_balance+0x3150/0x3d30 [btrfs] [ 58.777185] btrfs_ioctl_balance+0xd84/0x1410 [btrfs] [ 58.777621] btrfs_ioctl+0x4caa/0x114e0 [btrfs] ... Reported-by: TOTE Robot <oslab@tsinghua.edu.cn> CC: stable@vger.kernel.org # 5.15+ Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Zixuan Fu <r33s3n6@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Stefan Ghinea <stefan.ghinea@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-14btrfs: check return value of btrfs_commit_transaction in relocationJosef Bacik
commit fb686c6824dd6294ca772b92424b8fba666e7d00 upstream. There are a few places where we don't check the return value of btrfs_commit_transaction in relocation.c. Thankfully all these places have straightforward error handling, so simply change all of the sites at once. Reviewed-by: Qu Wenruo <wqu@suse.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: Stefan Ghinea <stefan.ghinea@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-30btrfs: use nofs when cleaning up aborted transactionsJosef Bacik
commit 597441b3436a43011f31ce71dc0a6c0bf5ce958a upstream. Our CI system caught a lockdep splat: ====================================================== WARNING: possible circular locking dependency detected 6.3.0-rc7+ #1167 Not tainted ------------------------------------------------------ kswapd0/46 is trying to acquire lock: ffff8c6543abd650 (sb_internal#2){++++}-{0:0}, at: btrfs_commit_inode_delayed_inode+0x5f/0x120 but task is already holding lock: ffffffffabe61b40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x4aa/0x7a0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (fs_reclaim){+.+.}-{0:0}: fs_reclaim_acquire+0xa5/0xe0 kmem_cache_alloc+0x31/0x2c0 alloc_extent_state+0x1d/0xd0 __clear_extent_bit+0x2e0/0x4f0 try_release_extent_mapping+0x216/0x280 btrfs_release_folio+0x2e/0x90 invalidate_inode_pages2_range+0x397/0x470 btrfs_cleanup_dirty_bgs+0x9e/0x210 btrfs_cleanup_one_transaction+0x22/0x760 btrfs_commit_transaction+0x3b7/0x13a0 create_subvol+0x59b/0x970 btrfs_mksubvol+0x435/0x4f0 __btrfs_ioctl_snap_create+0x11e/0x1b0 btrfs_ioctl_snap_create_v2+0xbf/0x140 btrfs_ioctl+0xa45/0x28f0 __x64_sys_ioctl+0x88/0xc0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc -> #0 (sb_internal#2){++++}-{0:0}: __lock_acquire+0x1435/0x21a0 lock_acquire+0xc2/0x2b0 start_transaction+0x401/0x730 btrfs_commit_inode_delayed_inode+0x5f/0x120 btrfs_evict_inode+0x292/0x3d0 evict+0xcc/0x1d0 inode_lru_isolate+0x14d/0x1e0 __list_lru_walk_one+0xbe/0x1c0 list_lru_walk_one+0x58/0x80 prune_icache_sb+0x39/0x60 super_cache_scan+0x161/0x1f0 do_shrink_slab+0x163/0x340 shrink_slab+0x1d3/0x290 shrink_node+0x300/0x720 balance_pgdat+0x35c/0x7a0 kswapd+0x205/0x410 kthread+0xf0/0x120 ret_from_fork+0x29/0x50 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(sb_internal#2); lock(fs_reclaim); lock(sb_internal#2); *** DEADLOCK *** 3 locks held by kswapd0/46: #0: ffffffffabe61b40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x4aa/0x7a0 #1: ffffffffabe50270 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab+0x113/0x290 #2: ffff8c6543abd0e0 (&type->s_umount_key#44){++++}-{3:3}, at: super_cache_scan+0x38/0x1f0 stack backtrace: CPU: 0 PID: 46 Comm: kswapd0 Not tainted 6.3.0-rc7+ #1167 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x58/0x90 check_noncircular+0xd6/0x100 ? save_trace+0x3f/0x310 ? add_lock_to_list+0x97/0x120 __lock_acquire+0x1435/0x21a0 lock_acquire+0xc2/0x2b0 ? btrfs_commit_inode_delayed_inode+0x5f/0x120 start_transaction+0x401/0x730 ? btrfs_commit_inode_delayed_inode+0x5f/0x120 btrfs_commit_inode_delayed_inode+0x5f/0x120 btrfs_evict_inode+0x292/0x3d0 ? lock_release+0x134/0x270 ? __pfx_wake_bit_function+0x10/0x10 evict+0xcc/0x1d0 inode_lru_isolate+0x14d/0x1e0 __list_lru_walk_one+0xbe/0x1c0 ? __pfx_inode_lru_isolate+0x10/0x10 ? __pfx_inode_lru_isolate+0x10/0x10 list_lru_walk_one+0x58/0x80 prune_icache_sb+0x39/0x60 super_cache_scan+0x161/0x1f0 do_shrink_slab+0x163/0x340 shrink_slab+0x1d3/0x290 shrink_node+0x300/0x720 balance_pgdat+0x35c/0x7a0 kswapd+0x205/0x410 ? __pfx_autoremove_wake_function+0x10/0x10 ? __pfx_kswapd+0x10/0x10 kthread+0xf0/0x120 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x29/0x50 </TASK> This happens because when we abort the transaction in the transaction commit path we call invalidate_inode_pages2_range on our block group cache inodes (if we have space cache v1) and any delalloc inodes we may have. The plain invalidate_inode_pages2_range() call passes through GFP_KERNEL, which makes sense in most cases, but not here. Wrap these two invalidate callees with memalloc_nofs_save/memalloc_nofs_restore to make sure we don't end up with the fs reclaim dependency under the transaction dependency. CC: stable@vger.kernel.org # 4.14+ 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>
2023-05-30btrfs: fix space cache inconsistency after error loading it from diskFilipe Manana
[ Upstream commit 0004ff15ea26015a0a3a6182dca3b9d1df32e2b7 ] When loading a free space cache from disk, at __load_free_space_cache(), if we fail to insert a bitmap entry, we still increment the number of total bitmaps in the btrfs_free_space_ctl structure, which is incorrect since we failed to add the bitmap entry. On error we then empty the cache by calling __btrfs_remove_free_space_cache(), which will result in getting the total bitmaps counter set to 1. A failure to load a free space cache is not critical, so if a failure happens we just rebuild the cache by scanning the extent tree, which happens at block-group.c:caching_thread(). Yet the failure will result in having the total bitmaps of the btrfs_free_space_ctl always bigger by 1 then the number of bitmap entries we have. So fix this by having the total bitmaps counter be incremented only if we successfully added the bitmap entry. Fixes: a67509c30079 ("Btrfs: add a io_ctl struct and helpers for dealing with the space cache") Reviewed-by: Anand Jain <anand.jain@oracle.com> CC: stable@vger.kernel.org # 4.4+ 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: Sasha Levin <sashal@kernel.org>
2023-05-30btrfs: replace calls to btrfs_find_free_ino with btrfs_find_free_objectidNikolay Borisov
[ Upstream commit abadc1fcd72e887a8f875dabe4a07aa8c28ac8af ] The former is going away as part of the inode map removal so switch callers to btrfs_find_free_objectid. No functional changes since with INODE_MAP disabled (default) find_free_objectid was called anyway. 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: 0004ff15ea26 ("btrfs: fix space cache inconsistency after error loading it from disk") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-17btrfs: print-tree: parent bytenr must be aligned to sector sizeAnastasia Belova
commit c87f318e6f47696b4040b58f460d5c17ea0280e6 upstream. Check nodesize to sectorsize in alignment check in print_extent_item. The comment states that and this is correct, similar check is done elsewhere in the functions. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: ea57788eb76d ("btrfs: require only sector size alignment for parent eb bytenr") CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Anastasia Belova <abelova@astralinux.ru> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-17btrfs: fix btrfs_prev_leaf() to not return the same key twiceFilipe Manana
commit 6f932d4ef007d6a4ae03badcb749fbb8f49196f6 upstream. A call to btrfs_prev_leaf() may end up returning a path that points to the same item (key) again. This happens if while btrfs_prev_leaf(), after we release the path, a concurrent insertion happens, which moves items off from a sibling into the front of the previous leaf, and an item with the computed previous key does not exists. For example, suppose we have the two following leaves: Leaf A ------------------------------------------------------------- | ... key (300 96 10) key (300 96 15) key (300 96 16) | ------------------------------------------------------------- slot 20 slot 21 slot 22 Leaf B ------------------------------------------------------------- | key (300 96 20) key (300 96 21) key (300 96 22) ... | ------------------------------------------------------------- slot 0 slot 1 slot 2 If we call btrfs_prev_leaf(), from btrfs_previous_item() for example, with a path pointing to leaf B and slot 0 and the following happens: 1) At btrfs_prev_leaf() we compute the previous key to search as: (300 96 19), which is a key that does not exists in the tree; 2) Then we call btrfs_release_path() at btrfs_prev_leaf(); 3) Some other task inserts a key at leaf A, that sorts before the key at slot 20, for example it has an objectid of 299. In order to make room for the new key, the key at slot 22 is moved to the front of leaf B. This happens at push_leaf_right(), called from split_leaf(). After this leaf B now looks like: -------------------------------------------------------------------------------- | key (300 96 16) key (300 96 20) key (300 96 21) key (300 96 22) ... | -------------------------------------------------------------------------------- slot 0 slot 1 slot 2 slot 3 4) At btrfs_prev_leaf() we call btrfs_search_slot() for the computed previous key: (300 96 19). Since the key does not exists, btrfs_search_slot() returns 1 and with a path pointing to leaf B and slot 1, the item with key (300 96 20); 5) This makes btrfs_prev_leaf() return a path that points to slot 1 of leaf B, the same key as before it was called, since the key at slot 0 of leaf B (300 96 16) is less than the computed previous key, which is (300 96 19); 6) As a consequence btrfs_previous_item() returns a path that points again to the item with key (300 96 20). For some users of btrfs_prev_leaf() or btrfs_previous_item() this may not be functional a problem, despite not making sense to return a new path pointing again to the same item/key. However for a caller such as tree-log.c:log_dir_items(), this has a bad consequence, as it can result in not logging some dir index deletions in case the directory is being logged without holding the inode's VFS lock (logging triggered while logging a child inode for example) - for the example scenario above, in case the dir index keys 17, 18 and 19 were deleted in the current transaction. CC: stable@vger.kernel.org # 4.14+ 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>
2023-05-17btrfs: scrub: reject unsupported scrub flagsQu Wenruo
commit 604e6681e114d05a2e384c4d1e8ef81918037ef5 upstream. Since the introduction of scrub interface, the only flag that we support is BTRFS_SCRUB_READONLY. Thus there is no sanity checks, if there are some undefined flags passed in, we just ignore them. This is problematic if we want to introduce new scrub flags, as we have no way to determine if such flags are supported. Address the problem by introducing a check for the flags, and if unsupported flags are set, return -EOPNOTSUPP to inform the user space. This check should be backported for all supported kernels before any new scrub flags are introduced. CC: stable@vger.kernel.org # 4.14+ 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-03btrfs: send: limit number of clones and allocated memory sizeDavid Sterba
[ 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>
2023-02-22btrfs: limit device extents to the device sizeJosef Bacik
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>
2023-01-18btrfs: replace strncpy() with strscpy()Sasha Levin
[ 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>
2023-01-18btrfs: send: avoid unnecessary backref lookups when finding clone sourceFilipe Manana
[ Upstream commit 22a3c0ac8ed0043af209a15928ae4c4855b0a4c4 ] At find_extent_clone(), unless we are given an inline extent, a file extent item that represents hole or an extent that starts beyond the i_size, we always do backref walking to look for clone sources, unless if we have more than SEND_MAX_EXTENT_REFS (64) known references on the extent. However if we know we only have one reference in the extent item and only one clone source (the send root), then it's pointless to do the backref walking to search for clone sources, as we can't clone from any other root. So skip the backref walking in that case. The following test was run on a non-debug kernel (Debian's default kernel config): $ cat test.sh #!/bin/bash DEV=/dev/sdi MNT=/mnt/sdi mkfs.btrfs -f $DEV mount $DEV $MNT # Create an extent tree that's not too small and none of the # extents is shared. for ((i = 1; i <= 50000; i++)); do xfs_io -f -c "pwrite 0 4K" $MNT/file_$i > /dev/null echo -ne "\r$i files created..." done echo btrfs subvolume snapshot -r $MNT $MNT/snap start=$(date +%s%N) btrfs send $MNT/snap > /dev/null end=$(date +%s%N) dur=$(( (end - start) / 1000000 )) echo -e "\nsend took $dur milliseconds" umount $MNT Before this change: send took 5389 milliseconds After this change: send took 4519 milliseconds (-16.1%) Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Stable-dep-of: 63d5429f68a3 ("btrfs: replace strncpy() with strscpy()") Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-08btrfs: qgroup: fix sleep from invalid context bug in btrfs_qgroup_inherit()ChenXiaoSong
[ 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>
2022-12-08btrfs: free btrfs_path before copying inodes to userspaceAnand Jain
[ 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>
2022-12-08btrfs: free btrfs_path before copying subvol info to userspaceAnand Jain
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>
2022-12-08btrfs: free btrfs_path before copying fspath to userspaceAnand Jain
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>
2022-12-08btrfs: free btrfs_path before copying root refs to userspaceJosef Bacik
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>
2022-11-25btrfs: remove pointless and double ulist frees in error paths of qgroup testsFilipe Manana
[ 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>
2022-11-25btrfs: selftests: fix wrong error check in btrfs_free_dummy_root()Zhang Xiaoxu
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>
2022-11-10btrfs: fix type of parameter generation in btrfs_get_dentryDavid Sterba
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>
2022-11-10btrfs: fix ulist leaks in error paths of qgroup self testsFilipe Manana
[ 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>
2022-11-10btrfs: fix inode list leak during backref walking at resolve_indirect_refs()Filipe Manana
[ 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>
2022-11-03btrfs: fix processing of delayed tree block refs during backref walkingFilipe Manana
[ 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>
2022-11-03btrfs: fix processing of delayed data refs during backref walkingFilipe Manana
[ 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>
2022-10-26btrfs: fix race between quota enable and quota rescan ioctlFilipe Manana
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>
2022-09-05btrfs: check if root is readonly while setting security xattrGoldwyn Rodrigues
commit b51111271b0352aa596c5ae8faf06939e91b3b68 upstream. For a filesystem which has btrfs read-only property set to true, all write operations including xattr should be denied. However, security xattr can still be changed even if btrfs ro property is true. This happens because xattr_permission() does not have any restrictions on security.*, system.* and in some cases trusted.* from VFS and the decision is left to the underlying filesystem. See comments in xattr_permission() for more details. This patch checks if the root is read-only before performing the set xattr operation. Testcase: DEV=/dev/vdb MNT=/mnt mkfs.btrfs -f $DEV mount $DEV $MNT echo "file one" > $MNT/f1 setfattr -n "security.one" -v 2 $MNT/f1 btrfs property set /mnt ro true setfattr -n "security.one" -v 1 $MNT/f1 umount $MNT CC: stable@vger.kernel.org # 4.9+ Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@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>
2022-08-25btrfs: raid56: don't trust any cached sector in __raid56_parity_recover()Qu Wenruo
commit f6065f8edeb25f4a9dfe0b446030ad995a84a088 upstream. [BUG] There is a small workload which will always fail with recent kernel: (A simplified version from btrfs/125 test case) mkfs.btrfs -f -m raid5 -d raid5 -b 1G $dev1 $dev2 $dev3 mount $dev1 $mnt xfs_io -f -c "pwrite -S 0xee 0 1M" $mnt/file1 sync umount $mnt btrfs dev scan -u $dev3 mount -o degraded $dev1 $mnt xfs_io -f -c "pwrite -S 0xff 0 128M" $mnt/file2 umount $mnt btrfs dev scan mount $dev1 $mnt btrfs balance start --full-balance $mnt umount $mnt The failure is always failed to read some tree blocks: BTRFS info (device dm-4): relocating block group 217710592 flags data|raid5 BTRFS error (device dm-4): parent transid verify failed on 38993920 wanted 9 found 7 BTRFS error (device dm-4): parent transid verify failed on 38993920 wanted 9 found 7 ... [CAUSE] With the recently added debug output, we can see all RAID56 operations related to full stripe 38928384: 56.1183: raid56_read_partial: full_stripe=38928384 devid=2 type=DATA1 offset=0 opf=0x0 physical=9502720 len=65536 56.1185: raid56_read_partial: full_stripe=38928384 devid=3 type=DATA2 offset=16384 opf=0x0 physical=9519104 len=16384 56.1185: raid56_read_partial: full_stripe=38928384 devid=3 type=DATA2 offset=49152 opf=0x0 physical=9551872 len=16384 56.1187: raid56_write_stripe: full_stripe=38928384 devid=3 type=DATA2 offset=0 opf=0x1 physical=9502720 len=16384 56.1188: raid56_write_stripe: full_stripe=38928384 devid=3 type=DATA2 offset=32768 opf=0x1 physical=9535488 len=16384 56.1188: raid56_write_stripe: full_stripe=38928384 devid=1 type=PQ1 offset=0 opf=0x1 physical=30474240 len=16384 56.1189: raid56_write_stripe: full_stripe=38928384 devid=1 type=PQ1 offset=32768 opf=0x1 physical=30507008 len=16384 56.1218: raid56_write_stripe: full_stripe=38928384 devid=3 type=DATA2 offset=49152 opf=0x1 physical=9551872 len=16384 56.1219: raid56_write_stripe: full_stripe=38928384 devid=1 type=PQ1 offset=49152 opf=0x1 physical=30523392 len=16384 56.2721: raid56_parity_recover: full stripe=38928384 eb=39010304 mirror=2 56.2723: raid56_parity_recover: full stripe=38928384 eb=39010304 mirror=2 56.2724: raid56_parity_recover: full stripe=38928384 eb=39010304 mirror=2 Before we enter raid56_parity_recover(), we have triggered some metadata write for the full stripe 38928384, this leads to us to read all the sectors from disk. Furthermore, btrfs raid56 write will cache its calculated P/Q sectors to avoid unnecessary read. This means, for that full stripe, after any partial write, we will have stale data, along with P/Q calculated using that stale data. Thankfully due to patch "btrfs: only write the sectors in the vertical stripe which has data stripes" we haven't submitted all the corrupted P/Q to disk. When we really need to recover certain range, aka in raid56_parity_recover(), we will use the cached rbio, along with its cached sectors (the full stripe is all cached). This explains why we have no event raid56_scrub_read_recover() triggered. Since we have the cached P/Q which is calculated using the stale data, the recovered one will just be stale. In our particular test case, it will always return the same incorrect metadata, thus causing the same error message "parent transid verify failed on 39010304 wanted 9 found 7" again and again. [BTRFS DESTRUCTIVE RMW PROBLEM] Test case btrfs/125 (and above workload) always has its trouble with the destructive read-modify-write (RMW) cycle: 0 32K 64K Data1: | Good | Good | Data2: | Bad | Bad | Parity: | Good | Good | In above case, if we trigger any write into Data1, we will use the bad data in Data2 to re-generate parity, killing the only chance to recovery Data2, thus Data2 is lost forever. This destructive RMW cycle is not specific to btrfs RAID56, but there are some btrfs specific behaviors making the case even worse: - Btrfs will cache sectors for unrelated vertical stripes. In above example, if we're only writing into 0~32K range, btrfs will still read data range (32K ~ 64K) of Data1, and (64K~128K) of Data2. This behavior is to cache sectors for later update. Incidentally commit d4e28d9b5f04 ("btrfs: raid56: make steal_rbio() subpage compatible") has a bug which makes RAID56 to never trust the cached sectors, thus slightly improve the situation for recovery. Unfortunately, follow up fix "btrfs: update stripe_sectors::uptodate in steal_rbio" will revert the behavior back to the old one. - Btrfs raid56 partial write will update all P/Q sectors and cache them This means, even if data at (64K ~ 96K) of Data2 is free space, and only (96K ~ 128K) of Data2 is really stale data. And we write into that (96K ~ 128K), we will update all the parity sectors for the full stripe. This unnecessary behavior will completely kill the chance of recovery. Thankfully, an unrelated optimization "btrfs: only write the sectors in the vertical stripe which has data stripes" will prevent submitting the write bio for untouched vertical sectors. That optimization will keep the on-disk P/Q untouched for a chance for later recovery. [FIX] Although we have no good way to completely fix the destructive RMW (unless we go full scrub for each partial write), we can still limit the damage. With patch "btrfs: only write the sectors in the vertical stripe which has data stripes" now we won't really submit the P/Q of unrelated vertical stripes, so the on-disk P/Q should still be fine. Now we really need to do is just drop all the cached sectors when doing recovery. By this, we have a chance to read the original P/Q from disk, and have a chance to recover the stale data, while still keep the cache to speed up regular write path. In fact, just dropping all the cache for recovery path is good enough to allow the test case btrfs/125 along with the small script to pass reliably. The lack of metadata write after the degraded mount, and forced metadata COW is saving us this time. So this patch will fix the behavior by not trust any cache in __raid56_parity_recover(), to solve the problem while still keep the cache useful. But please note that this test pass DOES NOT mean we have solved the destructive RMW problem, we just do better damage control a little better. Related patches: - btrfs: only write the sectors in the vertical stripe - d4e28d9b5f04 ("btrfs: raid56: make steal_rbio() subpage compatible") - btrfs: update stripe_sectors::uptodate in steal_rbio Acked-by: David Sterba <dsterba@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25btrfs: only write the sectors in the vertical stripe which has data stripesQu Wenruo
commit bd8f7e627703ca5707833d623efcd43f104c7b3f upstream. If we have only 8K partial write at the beginning of a full RAID56 stripe, we will write the following contents: 0 8K 32K 64K Disk 1 (data): |XX| | | Disk 2 (data): | | | Disk 3 (parity): |XXXXXXXXXXXXXXX|XXXXXXXXXXXXXXX| |X| means the sector will be written back to disk. Note that, although we won't write any sectors from disk 2, but we will write the full 64KiB of parity to disk. This behavior is fine for now, but not for the future (especially for RAID56J, as we waste quite some space to journal the unused parity stripes). So here we will also utilize the btrfs_raid_bio::dbitmap, anytime we queue a higher level bio into an rbio, we will update rbio::dbitmap to indicate which vertical stripes we need to writeback. And at finish_rmw(), we also check dbitmap to see if we need to write any sector in the vertical stripe. So after the patch, above example will only lead to the following writeback pattern: 0 8K 32K 64K Disk 1 (data): |XX| | | Disk 2 (data): | | | Disk 3 (parity): |XX| | | Acked-by: David Sterba <dsterba@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25btrfs: fix lost error handling when looking up extended ref on log replayFilipe Manana
commit 7a6b75b79902e47f46328b57733f2604774fa2d9 upstream. During log replay, when processing inode references, if we get an error when looking up for an extended reference at __add_inode_ref(), we ignore it and proceed, returning success (0) if no other error happens after the lookup. This is obviously wrong because in case an extended reference exists and it encodes some name not in the log, we need to unlink it, otherwise the filesystem state will not match the state it had after the last fsync. So just make __add_inode_ref() return an error it gets from the extended reference lookup. Fixes: f186373fef005c ("btrfs: extended inode refs") CC: stable@vger.kernel.org # 4.9+ 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>
2022-08-25btrfs: reject log replay if there is unsupported RO compat flagQu Wenruo
commit dc4d31684974d140250f3ee612c3f0cab13b3146 upstream. [BUG] If we have a btrfs image with dirty log, along with an unsupported RO compatible flag: log_root 30474240 ... compat_flags 0x0 compat_ro_flags 0x40000003 ( FREE_SPACE_TREE | FREE_SPACE_TREE_VALID | unknown flag: 0x40000000 ) Then even if we can only mount it RO, we will still cause metadata update for log replay: BTRFS info (device dm-1): flagging fs with big metadata feature BTRFS info (device dm-1): using free space tree BTRFS info (device dm-1): has skinny extents BTRFS info (device dm-1): start tree-log replay This is definitely against RO compact flag requirement. [CAUSE] RO compact flag only forces us to do RO mount, but we will still do log replay for plain RO mount. Thus this will result us to do log replay and update metadata. This can be very problematic for new RO compat flag, for example older kernel can not understand v2 cache, and if we allow metadata update on RO mount and invalidate/corrupt v2 cache. [FIX] Just reject the mount unless rescue=nologreplay is provided: BTRFS error (device dm-1): cannot replay dirty log with unsupport optional features (0x40000000), try rescue=nologreplay instead We don't want to set rescue=nologreply directly, as this would make the end user to read the old data, and cause confusion. Since the such case is really rare, we're mostly fine to just reject the mount with an error message, which also includes the proper workaround. CC: stable@vger.kernel.org #4.9+ 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>
2022-06-14btrfs: repair super block num_devices automaticallyQu Wenruo
commit d201238ccd2f30b9bfcfadaeae0972e3a486a176 upstream. [BUG] There is a report that a btrfs has a bad super block num devices. This makes btrfs to reject the fs completely. BTRFS error (device sdd3): super_num_devices 3 mismatch with num_devices 2 found here BTRFS error (device sdd3): failed to read chunk tree: -22 BTRFS error (device sdd3): open_ctree failed [CAUSE] During btrfs device removal, chunk tree and super block num devs are updated in two different transactions: btrfs_rm_device() |- btrfs_rm_dev_item(device) | |- trans = btrfs_start_transaction() | | Now we got transaction X | | | |- btrfs_del_item() | | Now device item is removed from chunk tree | | | |- btrfs_commit_transaction() | Transaction X got committed, super num devs untouched, | but device item removed from chunk tree. | (AKA, super num devs is already incorrect) | |- cur_devices->num_devices--; |- cur_devices->total_devices--; |- btrfs_set_super_num_devices() All those operations are not in transaction X, thus it will only be written back to disk in next transaction. So after the transaction X in btrfs_rm_dev_item() committed, but before transaction X+1 (which can be minutes away), a power loss happen, then we got the super num mismatch. This has been fixed by commit bbac58698a55 ("btrfs: remove device item and update super block in the same transaction"). [FIX] Make the super_num_devices check less strict, converting it from a hard error to a warning, and reset the value to a correct one for the current or next transaction commit. As the number of device items is the critical information where the super block num_devices is only a cached value (and also useful for cross checking), it's safe to automatically update it. Other device related problems like missing device are handled after that and may require other means to resolve, like degraded mount. With this fix, potentially affected filesystems won't fail mount and require the manual repair by btrfs check. Reported-by: Luca Béla Palkovics <luca.bela.palkovics@gmail.com> Link: https://lore.kernel.org/linux-btrfs/CA+8xDSpvdm_U0QLBAnrH=zqDq_cWCOH5TiV46CKmp3igr44okQ@mail.gmail.com/ CC: stable@vger.kernel.org # 4.14+ 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>
2022-06-14btrfs: add "0x" prefix for unsupported optional featuresQu Wenruo
commit d5321a0fa8bc49f11bea0b470800962c17d92d8f upstream. The following error message lack the "0x" obviously: cannot mount because of unsupported optional features (4000) Add the prefix to make it less confusing. This can happen on older kernels that try to mount a filesystem with newer features so it makes sense to backport to older trees. CC: stable@vger.kernel.org # 4.14+ 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>
2022-05-12btrfs: always log symlinks in full modeFilipe Manana
commit d0e64a981fd841cb0f28fcd6afcac55e6f1e6994 upstream. On Linux, empty symlinks are invalid, and attempting to create one with the system call symlink(2) results in an -ENOENT error and this is explicitly documented in the man page. If we rename a symlink that was created in the current transaction and its parent directory was logged before, we actually end up logging the symlink without logging its content, which is stored in an inline extent. That means that after a power failure we can end up with an empty symlink, having no content and an i_size of 0 bytes. It can be easily reproduced like this: $ mkfs.btrfs -f /dev/sdc $ mount /dev/sdc /mnt $ mkdir /mnt/testdir $ sync # Create a file inside the directory and fsync the directory. $ touch /mnt/testdir/foo $ xfs_io -c "fsync" /mnt/testdir # Create a symlink inside the directory and then rename the symlink. $ ln -s /mnt/testdir/foo /mnt/testdir/bar $ mv /mnt/testdir/bar /mnt/testdir/baz # Now fsync again the directory, this persist the log tree. $ xfs_io -c "fsync" /mnt/testdir <power failure> $ mount /dev/sdc /mnt $ stat -c %s /mnt/testdir/baz 0 $ readlink /mnt/testdir/baz $ Fix this by always logging symlinks in full mode (LOG_INODE_ALL), so that their content is also logged. A test case for fstests will follow. CC: stable@vger.kernel.org # 4.9+ 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>
2022-04-15btrfs: fix qgroup reserve overflow the qgroup limitEthan Lien
commit b642b52d0b50f4d398cb4293f64992d0eed2e2ce upstream. We use extent_changeset->bytes_changed in qgroup_reserve_data() to record how many bytes we set for EXTENT_QGROUP_RESERVED state. Currently the bytes_changed is set as "unsigned int", and it will overflow if we try to fallocate a range larger than 4GiB. The result is we reserve less bytes and eventually break the qgroup limit. Unlike regular buffered/direct write, which we use one changeset for each ordered extent, which can never be larger than 256M. For fallocate, we use one changeset for the whole range, thus it no longer respects the 256M per extent limit, and caused the problem. The following example test script reproduces the problem: $ cat qgroup-overflow.sh #!/bin/bash DEV=/dev/sdj MNT=/mnt/sdj mkfs.btrfs -f $DEV mount $DEV $MNT # Set qgroup limit to 2GiB. btrfs quota enable $MNT btrfs qgroup limit 2G $MNT # Try to fallocate a 3GiB file. This should fail. echo echo "Try to fallocate a 3GiB file..." fallocate -l 3G $MNT/3G.file # Try to fallocate a 5GiB file. echo echo "Try to fallocate a 5GiB file..." fallocate -l 5G $MNT/5G.file # See we break the qgroup limit. echo sync btrfs qgroup show -r $MNT umount $MNT When running the test: $ ./qgroup-overflow.sh (...) Try to fallocate a 3GiB file... fallocate: fallocate failed: Disk quota exceeded Try to fallocate a 5GiB file... qgroupid         rfer         excl     max_rfer --------         ----         ----     -------- 0/5           5.00GiB      5.00GiB      2.00GiB Since we have no control of how bytes_changed is used, it's better to set it to u64. CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Ethan Lien <ethanlien@synology.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>