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2021-10-13nfsd4: Handle the NFSv4 READDIR 'dircount' hint being zeroTrond Myklebust1-8/+11
commit f2e717d655040d632c9015f19aa4275f8b16e7f2 upstream. RFC3530 notes that the 'dircount' field may be zero, in which case the recommendation is to ignore it, and only enforce the 'maxcount' field. In RFC5661, this recommendation to ignore a zero valued field becomes a requirement. Fixes: aee377644146 ("nfsd4: fix rd_dircount enforcement") Cc: <stable@vger.kernel.org> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-13nfsd: fix error handling of register_pernet_subsys() in init_nfsd()Patrick Ho1-1/+1
commit 1d625050c7c2dd877e108e382b8aaf1ae3cfe1f4 upstream. init_nfsd() should not unregister pernet subsys if the register fails but should instead unwind from the last successful operation which is register_filesystem(). Unregistering a failed register_pernet_subsys() call can result in a kernel GPF as revealed by programmatically injecting an error in register_pernet_subsys(). Verified the fix handled failure gracefully with no lingering nfsd entry in /proc/filesystems. This change was introduced by the commit bd5ae9288d64 ("nfsd: register pernet ops last, unregister first"), the original error handling logic was correct. Fixes: bd5ae9288d64 ("nfsd: register pernet ops last, unregister first") Cc: stable@vger.kernel.org Signed-off-by: Patrick Ho <Patrick.Ho@netapp.com> Acked-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-13ovl: fix IOCB_DIRECT if underlying fs doesn't support direct IOMiklos Szeredi1-1/+14
commit 1dc1eed46f9fa4cb8a07baa24fb44c96d6dd35c9 upstream. Normally the check at open time suffices, but e.g loop device does set IOCB_DIRECT after doing its own checks (which are not sufficent for overlayfs). Make sure we don't call the underlying filesystem read/write method with the IOCB_DIRECT if it's not supported. Reported-by: Huang Jianan <huangjianan@oppo.com> Fixes: 16914e6fc7e1 ("ovl: add ovl_read_iter()") Cc: <stable@vger.kernel.org> # v4.19 Tested-by: Huang Jianan <huangjianan@oppo.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-13ovl: fix missing negative dentry check in ovl_rename()Zheng Liang1-3/+7
commit a295aef603e109a47af355477326bd41151765b6 upstream. The following reproducer mkdir lower upper work merge touch lower/old touch lower/new mount -t overlay overlay -olowerdir=lower,upperdir=upper,workdir=work merge rm merge/new mv merge/old merge/new & unlink upper/new may result in this race: PROCESS A: rename("merge/old", "merge/new"); overwrite=true,ovl_lower_positive(old)=true, ovl_dentry_is_whiteout(new)=true -> flags |= RENAME_EXCHANGE PROCESS B: unlink("upper/new"); PROCESS A: lookup newdentry in new_upperdir call vfs_rename() with negative newdentry and RENAME_EXCHANGE Fix by adding the missing check for negative newdentry. Signed-off-by: Zheng Liang <zhengliang6@huawei.com> Fixes: e9be9d5e76e3 ("overlay filesystem") Cc: <stable@vger.kernel.org> # v3.18 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-09smb3: correct smb3 ACL security descriptorSteve French1-2/+2
[ Upstream commit b06d893ef2492245d0319b4136edb4c346b687a3 ] Address warning: fs/smbfs_client/smb2pdu.c:2425 create_sd_buf() warn: struct type mismatch 'smb3_acl vs cifs_acl' Pointed out by Dan Carpenter via smatch code analysis tool Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-10-09ext2: fix sleeping in atomic bugs on errorDan Carpenter1-8/+6
[ Upstream commit 372d1f3e1bfede719864d0d1fbf3146b1e638c88 ] The ext2_error() function syncs the filesystem so it sleeps. The caller is holding a spinlock so it's not allowed to sleep. ext2_statfs() <- disables preempt -> ext2_count_free_blocks() -> ext2_get_group_desc() Fix this by using WARN() to print an error message and a stack trace instead of using ext2_error(). Link: https://lore.kernel.org/r/20210921203233.GA16529@kili Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-10-09btrfs: fix mount failure due to past and transient device flush errorFilipe Manana1-0/+13
[ Upstream commit 6b225baababf1e3d41a4250e802cbd193e1343fb ] When we get an error flushing one device, during a super block commit, we record the error in the device structure, in the field 'last_flush_error'. This is used to later check if we should error out the super block commit, depending on whether the number of flush errors is greater than or equals to the maximum tolerated device failures for a raid profile. However if we get a transient device flush error, unmount the filesystem and later try to mount it, we can fail the mount because we treat that past error as critical and consider the device is missing. Even if it's very likely that the error will happen again, as it's probably due to a hardware related problem, there may be cases where the error might not happen again. One example is during testing, and a test case like the new generic/648 from fstests always triggers this. The test cases generic/019 and generic/475 also trigger this scenario, but very sporadically. When this happens we get an error like this: $ mount /dev/sdc /mnt mount: /mnt wrong fs type, bad option, bad superblock on /dev/sdc, missing codepage or helper program, or other error. $ dmesg (...) [12918.886926] BTRFS warning (device sdc): chunk 13631488 missing 1 devices, max tolerance is 0 for writable mount [12918.888293] BTRFS warning (device sdc): writable mount is not allowed due to too many missing devices [12918.890853] BTRFS error (device sdc): open_ctree failed The failure happens because when btrfs_check_rw_degradable() is called at mount time, or at remount from RO to RW time, is sees a non zero value in a device's ->last_flush_error attribute, and therefore considers that the device is 'missing'. Fix this by setting a device's ->last_flush_error to zero when we close a device, making sure the error is not seen on the next mount attempt. We only need to track flush errors during the current mount, so that we never commit a super block if such errors happened. 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>
2021-10-09btrfs: replace BUG_ON() in btrfs_csum_one_bio() with proper error handlingQu Wenruo1-1/+12
[ Upstream commit bbc9a6eb5eec03dcafee266b19f56295e3b2aa8f ] There is a BUG_ON() in btrfs_csum_one_bio() to catch code logic error. It has indeed caught several bugs during subpage development. But the BUG_ON() itself will bring down the whole system which is an overkill. Replace it with a WARN() and exit gracefully, so that it won't crash the whole system while we can still catch the code logic error. 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>
2021-10-09nfsd: back channel stuck in SEQ4_STATUS_CB_PATH_DOWNDai Ngo1-3/+13
[ Upstream commit 02579b2ff8b0becfb51d85a975908ac4ab15fba8 ] When the back channel enters SEQ4_STATUS_CB_PATH_DOWN state, the client recovers by sending BIND_CONN_TO_SESSION but the server fails to recover the back channel and leaves it as NFSD4_CB_DOWN. Fix by enhancing nfsd4_bind_conn_to_session to probe the back channel by calling nfsd4_probe_callback. Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-10-06ext4: fix potential infinite loop in ext4_dx_readdir()yangerkun1-3/+3
commit 42cb447410d024e9d54139ae9c21ea132a8c384c upstream. When ext4_htree_fill_tree() fails, ext4_dx_readdir() can run into an infinite loop since if info->last_pos != ctx->pos this will reset the directory scan and reread the failing entry. For example: 1. a dx_dir which has 3 block, block 0 as dx_root block, block 1/2 as leaf block which own the ext4_dir_entry_2 2. block 1 read ok and call_filldir which will fill the dirent and update the ctx->pos 3. block 2 read fail, but we has already fill some dirent, so we will return back to userspace will a positive return val(see ksys_getdents64) 4. the second ext4_dx_readdir will reset the world since info->last_pos != ctx->pos, and will also init the curr_hash which pos to block 1 5. So we will read block1 too, and once block2 still read fail, we can only fill one dirent because the hash of the entry in block1(besides the last one) won't greater than curr_hash 6. this time, we forget update last_pos too since the read for block2 will fail, and since we has got the one entry, ksys_getdents64 can return success 7. Latter we will trapped in a loop with step 4~6 Cc: stable@kernel.org Signed-off-by: yangerkun <yangerkun@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Link: https://lore.kernel.org/r/20210914111415.3921954-1-yangerkun@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-06ext4: add error checking to ext4_ext_replay_set_iblocks()Theodore Ts'o1-5/+14
commit 1fd95c05d8f742abfe906620780aee4dbe1a2db0 upstream. If the call to ext4_map_blocks() fails due to an corrupted file system, ext4_ext_replay_set_iblocks() can get stuck in an infinite loop. This could be reproduced by running generic/526 with a file system that has inline_data and fast_commit enabled. The system will repeatedly log to the console: EXT4-fs warning (device dm-3): ext4_block_to_path:105: block 1074800922 > max in inode 131076 and the stack that it gets stuck in is: ext4_block_to_path+0xe3/0x130 ext4_ind_map_blocks+0x93/0x690 ext4_map_blocks+0x100/0x660 skip_hole+0x47/0x70 ext4_ext_replay_set_iblocks+0x223/0x440 ext4_fc_replay_inode+0x29e/0x3b0 ext4_fc_replay+0x278/0x550 do_one_pass+0x646/0xc10 jbd2_journal_recover+0x14a/0x270 jbd2_journal_load+0xc4/0x150 ext4_load_journal+0x1f3/0x490 ext4_fill_super+0x22d4/0x2c00 With this patch, generic/526 still fails, but system is no longer locking up in a tight loop. It's likely the root casue is that fast_commit replay is corrupting file systems with inline_data, and we probably need to add better error handling in the fast commit replay code path beyond what is done here, which essentially just breaks the infinite loop without reporting the to the higher levels of the code. Fixes: 8016E29F4362 ("ext4: fast commit recovery path") Cc: stable@kernel.org Cc: Harshad Shirwadkar <harshadshirwadkar@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-06ext4: fix reserved space counter leakageJeffle Xu2-0/+11
commit 6fed83957f21eff11c8496e9f24253b03d2bc1dc upstream. When ext4_insert_delayed block receives and recovers from an error from ext4_es_insert_delayed_block(), e.g., ENOMEM, it does not release the space it has reserved for that block insertion as it should. One effect of this bug is that s_dirtyclusters_counter is not decremented and remains incorrectly elevated until the file system has been unmounted. This can result in premature ENOSPC returns and apparent loss of free space. Another effect of this bug is that /sys/fs/ext4/<dev>/delayed_allocation_blocks can remain non-zero even after syncfs has been executed on the filesystem. Besides, add check for s_dirtyclusters_counter when inode is going to be evicted and freed. s_dirtyclusters_counter can still keep non-zero until inode is written back in .evict_inode(), and thus the check is delayed to .destroy_inode(). Fixes: 51865fda28e5 ("ext4: let ext4 maintain extent status tree") Cc: stable@kernel.org Suggested-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com> Reviewed-by: Eric Whitney <enwlinux@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Link: https://lore.kernel.org/r/20210823061358.84473-1-jefflexu@linux.alibaba.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-06ext4: limit the number of blocks in one ADD_RANGE TLVHou Tao1-0/+6
commit a2c2f0826e2b75560b31daf1cd9a755ab93cf4c6 upstream. Now EXT4_FC_TAG_ADD_RANGE uses ext4_extent to track the newly-added blocks, but the limit on the max value of ee_len field is ignored, and it can lead to BUG_ON as shown below when running command "fallocate -l 128M file" on a fast_commit-enabled fs: kernel BUG at fs/ext4/ext4_extents.h:199! invalid opcode: 0000 [#1] SMP PTI CPU: 3 PID: 624 Comm: fallocate Not tainted 5.14.0-rc6+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) RIP: 0010:ext4_fc_write_inode_data+0x1f3/0x200 Call Trace: ? ext4_fc_write_inode+0xf2/0x150 ext4_fc_commit+0x93b/0xa00 ? ext4_fallocate+0x1ad/0x10d0 ext4_sync_file+0x157/0x340 ? ext4_sync_file+0x157/0x340 vfs_fsync_range+0x49/0x80 do_fsync+0x3d/0x70 __x64_sys_fsync+0x14/0x20 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x44/0xae Simply fixing it by limiting the number of blocks in one EXT4_FC_TAG_ADD_RANGE TLV. Fixes: aa75f4d3daae ("ext4: main fast-commit commit path") Cc: stable@kernel.org Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Link: https://lore.kernel.org/r/20210820044505.474318-1-houtao1@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-06ext4: fix loff_t overflow in ext4_max_bitmap_size()Ritesh Harjani1-5/+5
commit 75ca6ad408f459f00b09a64f04c774559848c097 upstream. We should use unsigned long long rather than loff_t to avoid overflow in ext4_max_bitmap_size() for comparison before returning. w/o this patch sbi->s_bitmap_maxbytes was becoming a negative value due to overflow of upper_limit (with has_huge_files as true) Below is a quick test to trigger it on a 64KB pagesize system. sudo mkfs.ext4 -b 65536 -O ^has_extents,^64bit /dev/loop2 sudo mount /dev/loop2 /mnt sudo echo "hello" > /mnt/hello -> This will error out with "echo: write error: File too large" Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org Link: https://lore.kernel.org/r/594f409e2c543e90fd836b78188dfa5c575065ba.1622867594.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-06debugfs: debugfs_create_file_size(): use IS_ERR to check for errorNirmoy Das1-1/+1
commit af505cad9567f7a500d34bf183696d570d7f6810 upstream. debugfs_create_file() returns encoded error so use IS_ERR for checking return value. Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Nirmoy Das <nirmoy.das@amd.com> Fixes: ff9fb72bc077 ("debugfs: return error values, not NULL") Cc: stable <stable@vger.kernel.org> References: https://gitlab.freedesktop.org/drm/amd/-/issues/1686 Link: https://lore.kernel.org/r/20210902102917.2233-1-nirmoy.das@amd.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-06elf: don't use MAP_FIXED_NOREPLACE for elf interpreter mappingsChen Jingwen1-1/+1
commit 9b2f72cc0aa4bb444541bb87581c35b7508b37d3 upstream. In commit b212921b13bd ("elf: don't use MAP_FIXED_NOREPLACE for elf executable mappings") we still leave MAP_FIXED_NOREPLACE in place for load_elf_interp. Unfortunately, this will cause kernel to fail to start with: 1 (init): Uhuuh, elf segment at 00003ffff7ffd000 requested but the memory is mapped already Failed to execute /init (error -17) The reason is that the elf interpreter (ld.so) has overlapping segments. readelf -l ld-2.31.so Program Headers: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flags Align LOAD 0x0000000000000000 0x0000000000000000 0x0000000000000000 0x000000000002c94c 0x000000000002c94c R E 0x10000 LOAD 0x000000000002dae0 0x000000000003dae0 0x000000000003dae0 0x00000000000021e8 0x0000000000002320 RW 0x10000 LOAD 0x000000000002fe00 0x000000000003fe00 0x000000000003fe00 0x00000000000011ac 0x0000000000001328 RW 0x10000 The reason for this problem is the same as described in commit ad55eac74f20 ("elf: enforce MAP_FIXED on overlaying elf segments"). Not only executable binaries, elf interpreters (e.g. ld.so) can have overlapping elf segments, so we better drop MAP_FIXED_NOREPLACE and go back to MAP_FIXED in load_elf_interp. Fixes: 4ed28639519c ("fs, elf: drop MAP_FIXED usage from elf_map") Cc: <stable@vger.kernel.org> # v4.19 Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Chen Jingwen <chenjingwen6@huawei.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-06fs-verity: fix signed integer overflow with i_size near S64_MAXEric Biggers2-2/+2
commit 80f6e3080bfcf865062a926817b3ca6c4a137a57 upstream. If the file size is almost S64_MAX, the calculated number of Merkle tree levels exceeds FS_VERITY_MAX_LEVELS, causing FS_IOC_ENABLE_VERITY to fail. This is unintentional, since as the comment above the definition of FS_VERITY_MAX_LEVELS states, it is enough for over U64_MAX bytes of data using SHA-256 and 4K blocks. (Specifically, 4096*128**8 >= 2**64.) The bug is actually that when the number of blocks in the first level is calculated from i_size, there is a signed integer overflow due to i_size being signed. Fix this by treating i_size as unsigned. This was found by the new test "generic: test fs-verity EFBIG scenarios" (https://lkml.kernel.org/r/b1d116cd4d0ea74b9cd86f349c672021e005a75c.1631558495.git.boris@bur.io). This didn't affect ext4 or f2fs since those have a smaller maximum file size, but it did affect btrfs which allows files up to S64_MAX bytes. Reported-by: Boris Burkov <boris@bur.io> Fixes: 3fda4c617e84 ("fs-verity: implement FS_IOC_ENABLE_VERITY ioctl") Fixes: fd2d1acfcadf ("fs-verity: add the hook for file ->open()") Cc: <stable@vger.kernel.org> # v5.4+ Reviewed-by: Boris Burkov <boris@bur.io> Link: https://lore.kernel.org/r/20210916203424.113376-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-30qnx4: work around gcc false positive warning bugLinus Torvalds1-9/+27
commit d5f6545934c47e97c0b48a645418e877b452a992 upstream. In commit b7213ffa0e58 ("qnx4: avoid stringop-overread errors") I tried to teach gcc about how the directory entry structure can be two different things depending on a status flag. It made the code clearer, and it seemed to make gcc happy. However, Arnd points to a gcc bug, where despite using two different members of a union, gcc then gets confused, and uses the size of one of the members to decide if a string overrun happens. And not necessarily the rigth one. End result: with some configurations, gcc-11 will still complain about the source buffer size being overread: fs/qnx4/dir.c: In function 'qnx4_readdir': fs/qnx4/dir.c:76:32: error: 'strnlen' specified bound [16, 48] exceeds source size 1 [-Werror=stringop-overread] 76 | size = strnlen(name, size); | ^~~~~~~~~~~~~~~~~~~ fs/qnx4/dir.c:26:22: note: source object declared here 26 | char de_name; | ^~~~~~~ because gcc will get confused about which union member entry is actually getting accessed, even when the source code is very clear about it. Gcc internally will have combined two "redundant" pointers (pointing to different union elements that are at the same offset), and takes the size checking from one or the other - not necessarily the right one. This is clearly a gcc bug, but we can work around it fairly easily. The biggest thing here is the big honking comment about why we do what we do. Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99578#c6 Reported-and-tested-by: Arnd Bergmann <arnd@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-30qnx4: avoid stringop-overread errorsLinus Torvalds1-17/+34
[ Upstream commit b7213ffa0e585feb1aee3e7173e965e66ee0abaa ] The qnx4 directory entries are 64-byte blocks that have different contents depending on the a status byte that is in the last byte of the block. In particular, a directory entry can be either a "link info" entry with a 48-byte name and pointers to the real inode information, or an "inode entry" with a smaller 16-byte name and the full inode information. But the code was written to always just treat the directory name as if it was part of that "inode entry", and just extend the name to the longer case if the status byte said it was a link entry. That work just fine and gives the right results, but now that gcc is tracking data structure accesses much more, the code can trigger a compiler error about using up to 48 bytes (the long name) in a structure that only has that shorter name in it: fs/qnx4/dir.c: In function ‘qnx4_readdir’: fs/qnx4/dir.c:51:32: error: ‘strnlen’ specified bound 48 exceeds source size 16 [-Werror=stringop-overread] 51 | size = strnlen(de->di_fname, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from fs/qnx4/qnx4.h:3, from fs/qnx4/dir.c:16: include/uapi/linux/qnx4_fs.h:45:25: note: source object declared here 45 | char di_fname[QNX4_SHORT_NAME_MAX]; | ^~~~~~~~ which is because the source code doesn't really make this whole "one of two different types" explicit. Fix this by introducing a very explicit union of the two types, and basically explaining to the compiler what is really going on. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-30io_uring: put provided buffer meta data under memcg accountingJens Axboe1-1/+1
[ Upstream commit 9990da93d2bf9892c2c14c958bef050d4e461a1a ] For each provided buffer, we allocate a struct io_buffer to hold the data associated with it. As a large number of buffers can be provided, account that data with memcg. Fixes: ddf0322db79c ("io_uring: add IORING_OP_PROVIDE_BUFFERS") Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-30cifs: fix a sign extension bugDan Carpenter1-1/+1
[ Upstream commit e946d3c887a9dc33aa82a349c6284f4a084163f4 ] The problem is the mismatched types between "ctx->total_len" which is an unsigned int, "rc" which is an int, and "ctx->rc" which is a ssize_t. The code does: ctx->rc = (rc == 0) ? ctx->total_len : rc; We want "ctx->rc" to store the negative "rc" error code. But what happens is that "rc" is type promoted to a high unsigned int and 'ctx->rc" will store the high positive value instead of a negative value. The fix is to change "rc" from an int to a ssize_t. Fixes: c610c4b619e5 ("CIFS: Add asynchronous write support through kernel AIO") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-30treewide: Change list_sort to use const pointersSami Tolvanen18-30/+38
[ Upstream commit 4f0f586bf0c898233d8f316f471a21db2abd522d ] list_sort() internally casts the comparison function passed to it to a different type with constant struct list_head pointers, and uses this pointer to call the functions, which trips indirect call Control-Flow Integrity (CFI) checking. Instead of removing the consts, this change defines the list_cmp_func_t type and changes the comparison function types of all list_sort() callers to use const pointers, thus avoiding type mismatches. Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210408182843.1754385-10-samitolvanen@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-30afs: Fix updating of i_blocks on file/dir extensionDavid Howells4-13/+13
[ Upstream commit 9d37e1cab2a9d2cee2737973fa455e6f89eee46a ] When an afs file or directory is modified locally such that the total file size is extended, i_blocks needs to be recalculated too. Fix this by making afs_write_end() and afs_edit_dir_add() call afs_set_i_size() rather than setting inode->i_size directly as that also recalculates inode->i_blocks. This can be tested by creating and writing into directories and files and then examining them with du. Without this change, directories show a 4 blocks (they start out at 2048 bytes) and files show 0 blocks; with this change, they should show a number of blocks proportional to the file size rounded up to 1024. Fixes: 31143d5d515e ("AFS: implement basic file write support") Fixes: 63a4681ff39c ("afs: Locally edit directory data for mkdir/create/unlink/...") Reported-by: Markus Suvanto <markus.suvanto@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> Tested-by: Markus Suvanto <markus.suvanto@gmail.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/163113612442.352844.11162345591911691150.stgit@warthog.procyon.org.uk/ Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-30afs: Fix incorrect triggering of sillyrename on 3rd-party invalidationDavid Howells1-39/+7
[ Upstream commit 63d49d843ef5fffeea069e0ffdfbd2bf40ba01c6 ] The AFS filesystem is currently triggering the silly-rename cleanup from afs_d_revalidate() when it sees that a dentry has been changed by a third party[1]. It should not be doing this as the cleanup includes deleting the silly-rename target file on iput. Fix this by removing the places in the d_revalidate handling that validate anything other than the directory and the dirent. It probably should not be looking to validate the target inode of the dentry also. This includes removing the point in afs_d_revalidate() where the inode that a dentry used to point to was marked as being deleted (AFS_VNODE_DELETED). We don't know it got deleted. It could have been renamed or it could have hard links remaining. This was reproduced by cloning a git repo onto an afs volume on one machine, switching to another machine and doing "git status", then switching back to the first and doing "git status". The second status would show weird output due to ".git/index" getting deleted by the above mentioned mechanism. A simpler way to do it is to do: machine 1: touch a machine 2: touch b; mv -f b a machine 1: stat a on an afs volume. The bug shows up as the stat failing with ENOENT and the file server log showing that machine 1 deleted "a". Fixes: 79ddbfa500b3 ("afs: Implement sillyrename for unlink and rename") Reported-by: Markus Suvanto <markus.suvanto@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Markus Suvanto <markus.suvanto@gmail.com> cc: linux-afs@lists.infradead.org Link: https://bugzilla.kernel.org/show_bug.cgi?id=214217#c4 [1] Link: https://lore.kernel.org/r/163111668100.283156.3851669884664475428.stgit@warthog.procyon.org.uk/ Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-30btrfs: prevent __btrfs_dump_space_info() to underflow its free spaceQu Wenruo1-2/+3
commit 0619b7901473c380abc05d45cf9c70bee0707db3 upstream. It's not uncommon where __btrfs_dump_space_info() gets called under over-commit situations. In that case free space would underflow as total allocated space is not enough to handle all the over-committed space. Such underflow values can sometimes cause confusion for users enabled enospc_debug mount option, and takes some seconds for developers to convert the underflow value to signed result. Just output the free space as s64 to avoid such problem. Reported-by: Eli V <eliventer@gmail.com> Link: https://lore.kernel.org/linux-btrfs/CAJtFHUSy4zgyhf-4d9T+KdJp9w=UgzC2A0V=VtmaeEpcGgm1-Q@mail.gmail.com/ CC: stable@vger.kernel.org # 5.4+ 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>
2021-09-30cifs: fix incorrect check for null pointer in header_assembleSteve French1-2/+3
commit 9ed38fd4a15417cac83967360cf20b853bfab9b6 upstream. Although very unlikely that the tlink pointer would be null in this case, get_next_mid function can in theory return null (but not an error) so need to check for null (not for IS_ERR, which can not be returned here). Address warning: fs/smbfs_client/connect.c:2392 cifs_match_super() warn: 'tlink' isn't an ERR_PTR Pointed out by Dan Carpenter via smatch code analysis tool CC: stable@vger.kernel.org Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-30ocfs2: drop acl cache for directories tooWengang Wang1-1/+2
commit 9c0f0a03e386f4e1df33db676401547e1b7800c6 upstream. ocfs2_data_convert_worker() is currently dropping any cached acl info for FILE before down-converting meta lock. It should also drop for DIRECTORY. Otherwise the second acl lookup returns the cached one (from VFS layer) which could be already stale. The problem we are seeing is that the acl changes on one node doesn't get refreshed on other nodes in the following case: Node 1 Node 2 -------------- ---------------- getfacl dir1 getfacl dir1 <-- this is OK setfacl -m u:user1:rwX dir1 getfacl dir1 <-- see the change for user1 getfacl dir1 <-- can't see change for user1 Link: https://lkml.kernel.org/r/20210903012631.6099-1-wen.gang.wang@oracle.com Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-26nilfs2: fix memory leak in nilfs_sysfs_delete_snapshot_groupNanyong Sun1-1/+1
[ Upstream commit 17243e1c3072b8417a5ebfc53065d0a87af7ca77 ] kobject_put() should be used to cleanup the memory associated with the kobject instead of kobject_del(). See the section "Kobject removal" of "Documentation/core-api/kobject.rst". Link: https://lkml.kernel.org/r/20210629022556.3985106-7-sunnanyong@huawei.com Link: https://lkml.kernel.org/r/1625651306-10829-7-git-send-email-konishi.ryusuke@gmail.com Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-26nilfs2: fix memory leak in nilfs_sysfs_create_snapshot_groupNanyong Sun1-2/+2
[ Upstream commit b2fe39c248f3fa4bbb2a20759b4fdd83504190f7 ] If kobject_init_and_add returns with error, kobject_put() is needed here to avoid memory leak, because kobject_init_and_add may return error without freeing the memory associated with the kobject it allocated. Link: https://lkml.kernel.org/r/20210629022556.3985106-6-sunnanyong@huawei.com Link: https://lkml.kernel.org/r/1625651306-10829-6-git-send-email-konishi.ryusuke@gmail.com Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-26nilfs2: fix memory leak in nilfs_sysfs_delete_##name##_groupNanyong Sun1-1/+1
[ Upstream commit a3e181259ddd61fd378390977a1e4e2316853afa ] The kobject_put() should be used to cleanup the memory associated with the kobject instead of kobject_del. See the section "Kobject removal" of "Documentation/core-api/kobject.rst". Link: https://lkml.kernel.org/r/20210629022556.3985106-5-sunnanyong@huawei.com Link: https://lkml.kernel.org/r/1625651306-10829-5-git-send-email-konishi.ryusuke@gmail.com Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-26nilfs2: fix memory leak in nilfs_sysfs_create_##name##_groupNanyong Sun1-2/+2
[ Upstream commit 24f8cb1ed057c840728167dab33b32e44147c86f ] If kobject_init_and_add return with error, kobject_put() is needed here to avoid memory leak, because kobject_init_and_add may return error without freeing the memory associated with the kobject it allocated. Link: https://lkml.kernel.org/r/20210629022556.3985106-4-sunnanyong@huawei.com Link: https://lkml.kernel.org/r/1625651306-10829-4-git-send-email-konishi.ryusuke@gmail.com Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-26nilfs2: fix NULL pointer in nilfs_##name##_attr_releaseNanyong Sun1-5/+3
[ Upstream commit dbc6e7d44a514f231a64d9d5676e001b660b6448 ] In nilfs_##name##_attr_release, kobj->parent should not be referenced because it is a NULL pointer. The release() method of kobject is always called in kobject_put(kobj), in the implementation of kobject_put(), the kobj->parent will be assigned as NULL before call the release() method. So just use kobj to get the subgroups, which is more efficient and can fix a NULL pointer reference problem. Link: https://lkml.kernel.org/r/20210629022556.3985106-3-sunnanyong@huawei.com Link: https://lkml.kernel.org/r/1625651306-10829-3-git-send-email-konishi.ryusuke@gmail.com Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-26nilfs2: fix memory leak in nilfs_sysfs_create_device_groupNanyong Sun1-4/+2
[ Upstream commit 5f5dec07aca7067216ed4c1342e464e7307a9197 ] Patch series "nilfs2: fix incorrect usage of kobject". This patchset from Nanyong Sun fixes memory leak issues and a NULL pointer dereference issue caused by incorrect usage of kboject in nilfs2 sysfs implementation. This patch (of 6): Reported by syzkaller: BUG: memory leak unreferenced object 0xffff888100ca8988 (size 8): comm "syz-executor.1", pid 1930, jiffies 4294745569 (age 18.052s) hex dump (first 8 bytes): 6c 6f 6f 70 31 00 ff ff loop1... backtrace: kstrdup+0x36/0x70 mm/util.c:60 kstrdup_const+0x35/0x60 mm/util.c:83 kvasprintf_const+0xf1/0x180 lib/kasprintf.c:48 kobject_set_name_vargs+0x56/0x150 lib/kobject.c:289 kobject_add_varg lib/kobject.c:384 [inline] kobject_init_and_add+0xc9/0x150 lib/kobject.c:473 nilfs_sysfs_create_device_group+0x150/0x7d0 fs/nilfs2/sysfs.c:986 init_nilfs+0xa21/0xea0 fs/nilfs2/the_nilfs.c:637 nilfs_fill_super fs/nilfs2/super.c:1046 [inline] nilfs_mount+0x7b4/0xe80 fs/nilfs2/super.c:1316 legacy_get_tree+0x105/0x210 fs/fs_context.c:592 vfs_get_tree+0x8e/0x2d0 fs/super.c:1498 do_new_mount fs/namespace.c:2905 [inline] path_mount+0xf9b/0x1990 fs/namespace.c:3235 do_mount+0xea/0x100 fs/namespace.c:3248 __do_sys_mount fs/namespace.c:3456 [inline] __se_sys_mount fs/namespace.c:3433 [inline] __x64_sys_mount+0x14b/0x1f0 fs/namespace.c:3433 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae If kobject_init_and_add return with error, then the cleanup of kobject is needed because memory may be allocated in kobject_init_and_add without freeing. And the place of cleanup_dev_kobject should use kobject_put to free the memory associated with the kobject. As the section "Kobject removal" of "Documentation/core-api/kobject.rst" says, kobject_del() just makes the kobject "invisible", but it is not cleaned up. And no more cleanup will do after cleanup_dev_kobject, so kobject_put is needed here. Link: https://lkml.kernel.org/r/1625651306-10829-1-git-send-email-konishi.ryusuke@gmail.com Link: https://lkml.kernel.org/r/1625651306-10829-2-git-send-email-konishi.ryusuke@gmail.com Reported-by: Hulk Robot <hulkci@huawei.com> Link: https://lkml.kernel.org/r/20210629022556.3985106-2-sunnanyong@huawei.com Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-26btrfs: fix lockdep warning while mounting sprout fsAnand Jain1-3/+4
[ Upstream commit c124706900c20dee70f921bb3a90492431561a0a ] Following test case reproduces lockdep warning. Test case: $ mkfs.btrfs -f <dev1> $ btrfstune -S 1 <dev1> $ mount <dev1> <mnt> $ btrfs device add <dev2> <mnt> -f $ umount <mnt> $ mount <dev2> <mnt> $ umount <mnt> The warning claims a possible ABBA deadlock between the threads initiated by [#1] btrfs device add and [#0] the mount. [ 540.743122] WARNING: possible circular locking dependency detected [ 540.743129] 5.11.0-rc7+ #5 Not tainted [ 540.743135] ------------------------------------------------------ [ 540.743142] mount/2515 is trying to acquire lock: [ 540.743149] ffffa0c5544c2ce0 (&fs_devs->device_list_mutex){+.+.}-{4:4}, at: clone_fs_devices+0x6d/0x210 [btrfs] [ 540.743458] but task is already holding lock: [ 540.743461] ffffa0c54a7932b8 (btrfs-chunk-00){++++}-{4:4}, at: __btrfs_tree_read_lock+0x32/0x200 [btrfs] [ 540.743541] which lock already depends on the new lock. [ 540.743543] the existing dependency chain (in reverse order) is: [ 540.743546] -> #1 (btrfs-chunk-00){++++}-{4:4}: [ 540.743566] down_read_nested+0x48/0x2b0 [ 540.743585] __btrfs_tree_read_lock+0x32/0x200 [btrfs] [ 540.743650] btrfs_read_lock_root_node+0x70/0x200 [btrfs] [ 540.743733] btrfs_search_slot+0x6c6/0xe00 [btrfs] [ 540.743785] btrfs_update_device+0x83/0x260 [btrfs] [ 540.743849] btrfs_finish_chunk_alloc+0x13f/0x660 [btrfs] <--- device_list_mutex [ 540.743911] btrfs_create_pending_block_groups+0x18d/0x3f0 [btrfs] [ 540.743982] btrfs_commit_transaction+0x86/0x1260 [btrfs] [ 540.744037] btrfs_init_new_device+0x1600/0x1dd0 [btrfs] [ 540.744101] btrfs_ioctl+0x1c77/0x24c0 [btrfs] [ 540.744166] __x64_sys_ioctl+0xe4/0x140 [ 540.744170] do_syscall_64+0x4b/0x80 [ 540.744174] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 540.744180] -> #0 (&fs_devs->device_list_mutex){+.+.}-{4:4}: [ 540.744184] __lock_acquire+0x155f/0x2360 [ 540.744188] lock_acquire+0x10b/0x5c0 [ 540.744190] __mutex_lock+0xb1/0xf80 [ 540.744193] mutex_lock_nested+0x27/0x30 [ 540.744196] clone_fs_devices+0x6d/0x210 [btrfs] [ 540.744270] btrfs_read_chunk_tree+0x3c7/0xbb0 [btrfs] [ 540.744336] open_ctree+0xf6e/0x2074 [btrfs] [ 540.744406] btrfs_mount_root.cold.72+0x16/0x127 [btrfs] [ 540.744472] legacy_get_tree+0x38/0x90 [ 540.744475] vfs_get_tree+0x30/0x140 [ 540.744478] fc_mount+0x16/0x60 [ 540.744482] vfs_kern_mount+0x91/0x100 [ 540.744484] btrfs_mount+0x1e6/0x670 [btrfs] [ 540.744536] legacy_get_tree+0x38/0x90 [ 540.744537] vfs_get_tree+0x30/0x140 [ 540.744539] path_mount+0x8d8/0x1070 [ 540.744541] do_mount+0x8d/0xc0 [ 540.744543] __x64_sys_mount+0x125/0x160 [ 540.744545] do_syscall_64+0x4b/0x80 [ 540.744547] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 540.744551] other info that might help us debug this: [ 540.744552] Possible unsafe locking scenario: [ 540.744553] CPU0 CPU1 [ 540.744554] ---- ---- [ 540.744555] lock(btrfs-chunk-00); [ 540.744557] lock(&fs_devs->device_list_mutex); [ 540.744560] lock(btrfs-chunk-00); [ 540.744562] lock(&fs_devs->device_list_mutex); [ 540.744564] *** DEADLOCK *** [ 540.744565] 3 locks held by mount/2515: [ 540.744567] #0: ffffa0c56bf7a0e0 (&type->s_umount_key#42/1){+.+.}-{4:4}, at: alloc_super.isra.16+0xdf/0x450 [ 540.744574] #1: ffffffffc05a9628 (uuid_mutex){+.+.}-{4:4}, at: btrfs_read_chunk_tree+0x63/0xbb0 [btrfs] [ 540.744640] #2: ffffa0c54a7932b8 (btrfs-chunk-00){++++}-{4:4}, at: __btrfs_tree_read_lock+0x32/0x200 [btrfs] [ 540.744708] stack backtrace: [ 540.744712] CPU: 2 PID: 2515 Comm: mount Not tainted 5.11.0-rc7+ #5 But the device_list_mutex in clone_fs_devices() is redundant, as explained below. Two threads [1] and [2] (below) could lead to clone_fs_device(). [1] open_ctree <== mount sprout fs btrfs_read_chunk_tree() mutex_lock(&uuid_mutex) <== global lock read_one_dev() open_seed_devices() clone_fs_devices() <== seed fs_devices mutex_lock(&orig->device_list_mutex) <== seed fs_devices [2] btrfs_init_new_device() <== sprouting mutex_lock(&uuid_mutex); <== global lock btrfs_prepare_sprout() lockdep_assert_held(&uuid_mutex) clone_fs_devices(seed_fs_device) <== seed fs_devices Both of these threads hold uuid_mutex which is sufficient to protect getting the seed device(s) freed while we are trying to clone it for sprouting [2] or mounting a sprout [1] (as above). A mounted seed device can not free/write/replace because it is read-only. An unmounted seed device can be freed by btrfs_free_stale_devices(), but it needs uuid_mutex. So this patch removes the unnecessary device_list_mutex in clone_fs_devices(). And adds a lockdep_assert_held(&uuid_mutex) in clone_fs_devices(). Reported-by: Su Yue <l@damenly.su> Tested-by: Su Yue <l@damenly.su> Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-26btrfs: update the bdev time directly when closingJosef Bacik1-8/+10
[ Upstream commit 8f96a5bfa1503e0a5f3c78d51e993a1794d4aff1 ] We update the ctime/mtime of a block device when we remove it so that blkid knows the device changed. However we do this by re-opening the block device and calling filp_update_time. This is more correct because it'll call the inode->i_op->update_time if it exists, but the block dev inodes do not do this. Instead call generic_update_time() on the bd_inode in order to avoid the blkdev_open path and get rid of the following lockdep splat: ====================================================== WARNING: possible circular locking dependency detected 5.14.0-rc2+ #406 Not tainted ------------------------------------------------------ losetup/11596 is trying to acquire lock: ffff939640d2f538 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0 but task is already holding lock: ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&lo->lo_mutex){+.+.}-{3:3}: __mutex_lock+0x7d/0x750 lo_open+0x28/0x60 [loop] blkdev_get_whole+0x25/0xf0 blkdev_get_by_dev.part.0+0x168/0x3c0 blkdev_open+0xd2/0xe0 do_dentry_open+0x161/0x390 path_openat+0x3cc/0xa20 do_filp_open+0x96/0x120 do_sys_openat2+0x7b/0x130 __x64_sys_openat+0x46/0x70 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #3 (&disk->open_mutex){+.+.}-{3:3}: __mutex_lock+0x7d/0x750 blkdev_get_by_dev.part.0+0x56/0x3c0 blkdev_open+0xd2/0xe0 do_dentry_open+0x161/0x390 path_openat+0x3cc/0xa20 do_filp_open+0x96/0x120 file_open_name+0xc7/0x170 filp_open+0x2c/0x50 btrfs_scratch_superblocks.part.0+0x10f/0x170 btrfs_rm_device.cold+0xe8/0xed btrfs_ioctl+0x2a31/0x2e70 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #2 (sb_writers#12){.+.+}-{0:0}: lo_write_bvec+0xc2/0x240 [loop] loop_process_work+0x238/0xd00 [loop] process_one_work+0x26b/0x560 worker_thread+0x55/0x3c0 kthread+0x140/0x160 ret_from_fork+0x1f/0x30 -> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}: process_one_work+0x245/0x560 worker_thread+0x55/0x3c0 kthread+0x140/0x160 ret_from_fork+0x1f/0x30 -> #0 ((wq_completion)loop0){+.+.}-{0:0}: __lock_acquire+0x10ea/0x1d90 lock_acquire+0xb5/0x2b0 flush_workqueue+0x91/0x5e0 drain_workqueue+0xa0/0x110 destroy_workqueue+0x36/0x250 __loop_clr_fd+0x9a/0x660 [loop] block_ioctl+0x3f/0x50 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Chain exists of: (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&lo->lo_mutex); lock(&disk->open_mutex); lock(&lo->lo_mutex); lock((wq_completion)loop0); *** DEADLOCK *** 1 lock held by losetup/11596: #0: ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop] stack backtrace: CPU: 1 PID: 11596 Comm: losetup Not tainted 5.14.0-rc2+ #406 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/