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2021-12-08fget: check that the fd still exists after getting a ref to itLinus Torvalds1-0/+4
commit 054aa8d439b9185d4f5eb9a90282d1ce74772969 upstream. Jann Horn points out that there is another possible race wrt Unix domain socket garbage collection, somewhat reminiscent of the one fixed in commit cbcf01128d0a ("af_unix: fix garbage collect vs MSG_PEEK"). See the extended comment about the garbage collection requirements added to unix_peek_fds() by that commit for details. The race comes from how we can locklessly look up a file descriptor just as it is in the process of being closed, and with the right artificial timing (Jann added a few strategic 'mdelay(500)' calls to do that), the Unix domain socket garbage collector could see the reference count decrement of the close() happen before fget() took its reference to the file and the file was attached onto a new file descriptor. This is all (intentionally) correct on the 'struct file *' side, with RCU lookups and lockless reference counting very much part of the design. Getting that reference count out of order isn't a problem per se. But the garbage collector can get confused by seeing this situation of having seen a file not having any remaining external references and then seeing it being attached to an fd. In commit cbcf01128d0a ("af_unix: fix garbage collect vs MSG_PEEK") the fix was to serialize the file descriptor install with the garbage collector by taking and releasing the unix_gc_lock. That's not really an option here, but since this all happens when we are in the process of looking up a file descriptor, we can instead simply just re-check that the file hasn't been closed in the meantime, and just re-do the lookup if we raced with a concurrent close() of the same file descriptor. Reported-and-tested-by: Jann Horn <jannh@google.com> Acked-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08btrfs: check-integrity: fix a warning on write caching disabled diskWang Yugui1-1/+13
[ Upstream commit a91cf0ffbc244792e0b3ecf7d0fddb2f344b461f ] When a disk has write caching disabled, we skip submission of a bio with flush and sync requests before writing the superblock, since it's not needed. However when the integrity checker is enabled, this results in reports that there are metadata blocks referred by a superblock that were not properly flushed. So don't skip the bio submission only when the integrity checker is enabled for the sake of simplicity, since this is a debug tool and not meant for use in non-debug builds. fstests/btrfs/220 trigger a check-integrity warning like the following when CONFIG_BTRFS_FS_CHECK_INTEGRITY=y and the disk with WCE=0. btrfs: attempt to write superblock which references block M @5242880 (sdb2/5242880/0) which is not flushed out of disk's write cache (block flush_gen=1, dev->flush_gen=0)! ------------[ cut here ]------------ WARNING: CPU: 28 PID: 843680 at fs/btrfs/check-integrity.c:2196 btrfsic_process_written_superblock+0x22a/0x2a0 [btrfs] CPU: 28 PID: 843680 Comm: umount Not tainted 5.15.0-0.rc5.39.el8.x86_64 #1 Hardware name: Dell Inc. Precision T7610/0NK70N, BIOS A18 09/11/2019 RIP: 0010:btrfsic_process_written_superblock+0x22a/0x2a0 [btrfs] RSP: 0018:ffffb642afb47940 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000000 RDX: 00000000ffffffff RSI: ffff8b722fc97d00 RDI: ffff8b722fc97d00 RBP: ffff8b5601c00000 R08: 0000000000000000 R09: c0000000ffff7fff R10: 0000000000000001 R11: ffffb642afb476f8 R12: ffffffffffffffff R13: ffffb642afb47974 R14: ffff8b5499254c00 R15: 0000000000000003 FS: 00007f00a06d4080(0000) GS:ffff8b722fc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff5cff5ff0 CR3: 00000001c0c2a006 CR4: 00000000001706e0 Call Trace: btrfsic_process_written_block+0x2f7/0x850 [btrfs] __btrfsic_submit_bio.part.19+0x310/0x330 [btrfs] ? bio_associate_blkg_from_css+0xa4/0x2c0 btrfsic_submit_bio+0x18/0x30 [btrfs] write_dev_supers+0x81/0x2a0 [btrfs] ? find_get_pages_range_tag+0x219/0x280 ? pagevec_lookup_range_tag+0x24/0x30 ? __filemap_fdatawait_range+0x6d/0xf0 ? __raw_callee_save___native_queued_spin_unlock+0x11/0x1e ? find_first_extent_bit+0x9b/0x160 [btrfs] ? __raw_callee_save___native_queued_spin_unlock+0x11/0x1e write_all_supers+0x1b3/0xa70 [btrfs] ? __raw_callee_save___native_queued_spin_unlock+0x11/0x1e btrfs_commit_transaction+0x59d/0xac0 [btrfs] close_ctree+0x11d/0x339 [btrfs] generic_shutdown_super+0x71/0x110 kill_anon_super+0x14/0x30 btrfs_kill_super+0x12/0x20 [btrfs] deactivate_locked_super+0x31/0x70 cleanup_mnt+0xb8/0x140 task_work_run+0x6d/0xb0 exit_to_user_mode_prepare+0x1f0/0x200 syscall_exit_to_user_mode+0x12/0x30 do_syscall_64+0x46/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f009f711dfb RSP: 002b:00007fff5cff7928 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 000055b68c6c9970 RCX: 00007f009f711dfb RDX: 0000000000000001 RSI: 0000000000000000 RDI: 000055b68c6c9b50 RBP: 0000000000000000 R08: 000055b68c6ca900 R09: 00007f009f795580 R10: 0000000000000000 R11: 0000000000000246 R12: 000055b68c6c9b50 R13: 00007f00a04bf184 R14: 0000000000000000 R15: 00000000ffffffff ---[ end trace 2c4b82abcef9eec4 ]--- S-65536(sdb2/65536/1) --> M-1064960(sdb2/1064960/1) Reviewed-by: Filipe Manana <fdmanana@gmail.com> Signed-off-by: Wang Yugui <wangyugui@e16-tech.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-08gfs2: Fix length of holes reported at end-of-fileAndreas Gruenbacher1-1/+1
[ Upstream commit f3506eee81d1f700d9ee2d2f4a88fddb669ec032 ] Fix the length of holes reported at the end of a file: the length is relative to the beginning of the extent, not the seek position which is rounded down to the filesystem block size. This bug went unnoticed for some time, but is now caught by the following assertion in iomap_iter_done(): WARN_ON_ONCE(iter->iomap.offset + iter->iomap.length <= iter->pos) Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-08gfs2: release iopen glock early in evictBob Peterson1-7/+7
[ Upstream commit 49462e2be119d38c5eb5759d0d1b712df3a41239 ] Before this patch, evict would clear the iopen glock's gl_object after releasing the inode glock. In the meantime, another process could reuse the same block and thus glocks for a new inode. It would lock the inode glock (exclusively), and then the iopen glock (shared). The shared locking mode doesn't provide any ordering against the evict, so by the time the iopen glock is reused, evict may not have gotten to setting gl_object to NULL. Fix that by releasing the iopen glock before the inode glock in gfs2_evict_inode. Signed-off-by: Bob Peterson <rpeterso@redhat.com>gl_object Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-08ovl: fix deadlock in splice writeMiklos Szeredi1-1/+46
commit 9b91b6b019fda817eb52f728eb9c79b3579760bc upstream. There's possibility of an ABBA deadlock in case of a splice write to an overlayfs file and a concurrent splice write to a corresponding real file. The call chain for splice to an overlay file: -> do_splice [takes sb_writers on overlay file] -> do_splice_from -> iter_file_splice_write [takes pipe->mutex] -> vfs_iter_write ... -> ovl_write_iter [takes sb_writers on real file] And the call chain for splice to a real file: -> do_splice [takes sb_writers on real file] -> do_splice_from -> iter_file_splice_write [takes pipe->mutex] Syzbot successfully bisected this to commit 82a763e61e2b ("ovl: simplify file splice"). Fix by reverting the write part of the above commit and by adding missing bits from ovl_write_iter() into ovl_splice_write(). Fixes: 82a763e61e2b ("ovl: simplify file splice") Reported-and-tested-by: syzbot+579885d1a9a833336209@syzkaller.appspotmail.com Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: Stan Hu <stanhu@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08ovl: simplify file spliceMiklos Szeredi1-44/+2
commit 82a763e61e2b601309d696d4fa514c77d64ee1be upstream. generic_file_splice_read() and iter_file_splice_write() will call back into f_op->iter_read() and f_op->iter_write() respectively. These already do the real file lookup and cred override. So the code in ovl_splice_read() and ovl_splice_write() is redundant. In addition the ovl_file_accessed() call in ovl_splice_write() is incorrect, though probably harmless. Fix by calling generic_file_splice_read() and iter_file_splice_write() directly. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: Stan Hu <stanhu@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08NFSv42: Fix pagecache invalidation after COPY/CLONEBenjamin Coddington1-2/+3
commit 3f015d89a47cd8855cd92f71fff770095bd885a1 upstream. The mechanism in use to allow the client to see the results of COPY/CLONE is to drop those pages from the pagecache. This forces the client to read those pages once more from the server. However, truncate_pagecache_range() zeros out partial pages instead of dropping them. Let us instead use invalidate_inode_pages2_range() with full-page offsets to ensure the client properly sees the results of COPY/CLONE operations. Cc: <stable@vger.kernel.org> # v4.7+ Fixes: 2e72448b07dc ("NFS: Add COPY nfs operation") Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-01smb3: do not error on fsync when readonlySteve French1-6/+29
[ Upstream commit 71e6864eacbef0b2645ca043cdfbac272cb6cea3 ] Linux allows doing a flush/fsync on a file open for read-only, but the protocol does not allow that. If the file passed in on the flush is read-only try to find a writeable handle for the same inode, if that is not possible skip sending the fsync call to the server to avoid breaking the apps. Reported-by: Julian Sikorski <belegdol@gmail.com> Tested-by: Julian Sikorski <belegdol@gmail.com> Suggested-by: Jeremy Allison <jra@samba.org> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-01ceph: properly handle statfs on multifs setupsJeff Layton1-5/+6
[ Upstream commit 8cfc0c7ed34f7929ce7e5d7c6eecf4d01ba89a84 ] ceph_statfs currently stuffs the cluster fsid into the f_fsid field. This was fine when we only had a single filesystem per cluster, but now that we have multiples we need to use something that will vary between them. Change ceph_statfs to xor each 32-bit chunk of the fsid (aka cluster id) into the lower bits of the statfs->f_fsid. Change the lower bits to hold the fscid (filesystem ID within the cluster). That should give us a value that is guaranteed to be unique between filesystems within a cluster, and should minimize the chance of collisions between mounts of different clusters. URL: https://tracker.ceph.com/issues/52812 Reported-by: Sachin Prabhu <sprabhu@redhat.com> Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Xiubo Li <xiubli@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-01f2fs: set SBI_NEED_FSCK flag when inconsistent node block foundWeichao Guo1-0/+1
[ Upstream commit 6663b138ded1a59e630c9e605e42aa7fde490cdc ] Inconsistent node block will cause a file fail to open or read, which could make the user process crashes or stucks. Let's mark SBI_NEED_FSCK flag to trigger a fix at next fsck time. After unlinking the corrupted file, the user process could regenerate a new one and work correctly. Signed-off-by: Weichao Guo <guoweichao@oppo.com> Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-01erofs: fix deadlock when shrink erofs slabHuang Jianan1-2/+6
[ Upstream commit 57bbeacdbee72a54eb97d56b876cf9c94059fc34 ] We observed the following deadlock in the stress test under low memory scenario: Thread A Thread B - erofs_shrink_scan - erofs_try_to_release_workgroup - erofs_workgroup_try_to_freeze -- A - z_erofs_do_read_page - z_erofs_collection_begin - z_erofs_register_collection - erofs_insert_workgroup - xa_lock(&sbi->managed_pslots) -- B - erofs_workgroup_get - erofs_wait_on_workgroup_freezed -- A - xa_erase - xa_lock(&sbi->managed_pslots) -- B To fix this, it needs to hold xa_lock before freezing the workgroup since xarray will be touched then. So let's hold the lock before accessing each workgroup, just like what we did with the radix tree before. [ Gao Xiang: Jianhua Hao also reports this issue at https://lore.kernel.org/r/b10b85df30694bac8aadfe43537c897a@xiaomi.com ] Link: https://lore.kernel.org/r/20211118135844.3559-1-huangjianan@oppo.com Fixes: 64094a04414f ("erofs: convert workstn to XArray") Reviewed-by: Chao Yu <chao@kernel.org> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Huang Jianan <huangjianan@oppo.com> Reported-by: Jianhua Hao <haojianhua1@xiaomi.com> Signed-off-by: Gao Xiang <xiang@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-01NFSv42: Don't fail clone() unless the OP_CLONE operation failedTrond Myklebust1-2/+1
[ Upstream commit d3c45824ad65aebf765fcf51366d317a29538820 ] The failure to retrieve post-op attributes has no bearing on whether or not the clone operation itself was successful. We must therefore ignore the return value of decode_getfattr() when looking at the success or failure of nfs4_xdr_dec_clone(). Fixes: 36022770de6c ("nfs42: add CLONE xdr functions") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-01proc/vmcore: fix clearing user buffer by properly using clear_user()David Hildenbrand1-6/+10
commit c1e63117711977cc4295b2ce73de29dd17066c82 upstream. To clear a user buffer we cannot simply use memset, we have to use clear_user(). With a virtio-mem device that registers a vmcore_cb and has some logically unplugged memory inside an added Linux memory block, I can easily trigger a BUG by copying the vmcore via "cp": systemd[1]: Starting Kdump Vmcore Save Service... kdump[420]: Kdump is using the default log level(3). kdump[453]: saving to /sysroot/var/crash/127.0.0.1-2021-11-11-14:59:22/ kdump[458]: saving vmcore-dmesg.txt to /sysroot/var/crash/127.0.0.1-2021-11-11-14:59:22/ kdump[465]: saving vmcore-dmesg.txt complete kdump[467]: saving vmcore BUG: unable to handle page fault for address: 00007f2374e01000 #PF: supervisor write access in kernel mode #PF: error_code(0x0003) - permissions violation PGD 7a523067 P4D 7a523067 PUD 7a528067 PMD 7a525067 PTE 800000007048f867 Oops: 0003 [#1] PREEMPT SMP NOPTI CPU: 0 PID: 468 Comm: cp Not tainted 5.15.0+ #6 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.14.0-27-g64f37cc530f1-prebuilt.qemu.org 04/01/2014 RIP: 0010:read_from_oldmem.part.0.cold+0x1d/0x86 Code: ff ff ff e8 05 ff fe ff e9 b9 e9 7f ff 48 89 de 48 c7 c7 38 3b 60 82 e8 f1 fe fe ff 83 fd 08 72 3c 49 8d 7d 08 4c 89 e9 89 e8 <49> c7 45 00 00 00 00 00 49 c7 44 05 f8 00 00 00 00 48 83 e7 f81 RSP: 0018:ffffc9000073be08 EFLAGS: 00010212 RAX: 0000000000001000 RBX: 00000000002fd000 RCX: 00007f2374e01000 RDX: 0000000000000001 RSI: 00000000ffffdfff RDI: 00007f2374e01008 RBP: 0000000000001000 R08: 0000000000000000 R09: ffffc9000073bc50 R10: ffffc9000073bc48 R11: ffffffff829461a8 R12: 000000000000f000 R13: 00007f2374e01000 R14: 0000000000000000 R15: ffff88807bd421e8 FS: 00007f2374e12140(0000) GS:ffff88807f000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2374e01000 CR3: 000000007a4aa000 CR4: 0000000000350eb0 Call Trace: read_vmcore+0x236/0x2c0 proc_reg_read+0x55/0xa0 vfs_read+0x95/0x190 ksys_read+0x4f/0xc0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae Some x86-64 CPUs have a CPU feature called "Supervisor Mode Access Prevention (SMAP)", which is used to detect wrong access from the kernel to user buffers like this: SMAP triggers a permissions violation on wrong access. In the x86-64 variant of clear_user(), SMAP is properly handled via clac()+stac(). To fix, properly use clear_user() when we're dealing with a user buffer. Link: https://lkml.kernel.org/r/20211112092750.6921-1-david@redhat.com Fixes: 997c136f518c ("fs/proc/vmcore.c: add hook to read_from_oldmem() to check for non-ram pages") Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Baoquan He <bhe@redhat.com> Cc: Dave Young <dyoung@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Philipp Rudo <prudo@redhat.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>
2021-12-01fuse: release pipe buf after last useMiklos Szeredi1-5/+5
commit 473441720c8616dfaf4451f9c7ea14f0eb5e5d65 upstream. Checking buf->flags should be done before the pipe_buf_release() is called on the pipe buffer, since releasing the buffer might modify the flags. This is exactly what page_cache_pipe_buf_release() does, and which results in the same VM_BUG_ON_PAGE(PageLRU(page)) that the original patch was trying to fix. Reported-by: Justin Forbes <jmforbes@linuxtx.org> Fixes: 712a951025c0 ("fuse: fix page stealing") Cc: <stable@vger.kernel.org> # v2.6.35 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-26btrfs: update device path inode time instead of bd_inodeJosef Bacik1-8/+13
commit 54fde91f52f515e0b1514f0f0fa146e87a672227 upstream. Christoph pointed out that I'm updating bdev->bd_inode for the device time when we remove block devices from a btrfs file system, however this isn't actually exposed to anything. The inode we want to update is the one that's associated with the path to the device, usually on devtmpfs, so that blkid notices the difference. We still don't want to do the blkdev_open, so use kern_path() to get the path to the given device and do the update time on that inode. Fixes: 8f96a5bfa150 ("btrfs: update the bdev time directly when closing") Reported-by: Christoph Hellwig <hch@lst.de> 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>
2021-11-26fs: export an inode_update_time helperJosef Bacik1-3/+4
commit e60feb445fce9e51c1558a6aa7faf9dd5ded533b upstream. If you already have an inode and need to update the time on the inode there is no way to do this properly. Export this helper to allow file systems to update time on the inode so the appropriate handler is called, either ->update_time or generic_update_time. 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>
2021-11-26btrfs: fix memory ordering between normal and ordered work functionsNikolay Borisov1-0/+14
commit 45da9c1767ac31857df572f0a909fbe88fd5a7e9 upstream. Ordered work functions aren't guaranteed to be handled by the same thread which executed the normal work functions. The only way execution between normal/ordered functions is synchronized is via the WORK_DONE_BIT, unfortunately the used bitops don't guarantee any ordering whatsoever. This manifested as seemingly inexplicable crashes on ARM64, where async_chunk::inode is seen as non-null in async_cow_submit which causes submit_compressed_extents to be called and crash occurs because async_chunk::inode suddenly became NULL. The call trace was similar to: pc : submit_compressed_extents+0x38/0x3d0 lr : async_cow_submit+0x50/0xd0 sp : ffff800015d4bc20 <registers omitted for brevity> Call trace: submit_compressed_extents+0x38/0x3d0 async_cow_submit+0x50/0xd0 run_ordered_work+0xc8/0x280 btrfs_work_helper+0x98/0x250 process_one_work+0x1f0/0x4ac worker_thread+0x188/0x504 kthread+0x110/0x114 ret_from_fork+0x10/0x18 Fix this by adding respective barrier calls which ensure that all accesses preceding setting of WORK_DONE_BIT are strictly ordered before setting the flag. At the same time add a read barrier after reading of WORK_DONE_BIT in run_ordered_work which ensures all subsequent loads would be strictly ordered after reading the bit. This in turn ensures are all accesses before WORK_DONE_BIT are going to be strictly ordered before any access that can occur in ordered_func. Reported-by: Chris Murphy <lists@colorremedies.com> Fixes: 08a9ff326418 ("btrfs: Added btrfs_workqueue_struct implemented ordered execution based on kernel workqueue") CC: stable@vger.kernel.org # 4.4+ Link: https://bugzilla.redhat.com/show_bug.cgi?id=2011928 Reviewed-by: Josef Bacik <josef@toxicpanda.com> Tested-by: Chris Murphy <chris@colorremedies.com> Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-26udf: Fix crash after seekdirJan Kara3-2/+35
commit a48fc69fe6588b48d878d69de223b91a386a7cb4 upstream. udf_readdir() didn't validate the directory position it should start reading from. Thus when user uses lseek(2) on directory file descriptor it can trick udf_readdir() into reading from a position in the middle of directory entry which then upsets directory parsing code resulting in errors or even possible kernel crashes. Similarly when the directory is modified between two readdir calls, the directory position need not be valid anymore. Add code to validate current offset in the directory. This is actually rather expensive for UDF as we need to read from the beginning of the directory and parse all directory entries. This is because in UDF a directory is just a stream of data containing directory entries and since file names are fully under user's control we cannot depend on detecting magic numbers and checksums in the header of directory entry as a malicious attacker could fake them. We skip this step if we detect that nothing changed since the last readdir call. Reported-by: Nathan Wilson <nate@chickenbrittle.com> CC: stable@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-26f2fs: fix incorrect return value in f2fs_sanity_check_ckpt()Chao Yu1-1/+1
[ Upstream commit ca98d72141dd81f42893a9a43d7ededab3355fba ] As Pavel Machek reported in [1] This code looks quite confused: part of function returns 1 on corruption, part returns -errno. The problem is not stable-specific. [1] https://lkml.org/lkml/2021/9/19/207 Let's fix to make 'insane cp_payload case' to return 1 rater than EFSCORRUPTED, so that return value can be kept consistent for all error cases, it can avoid confusion of code logic. Fixes: 65ddf6564843 ("f2fs: fix to do sanity check for sb/cp fields correctly") Reported-by: Pavel Machek <pavel@denx.de> Reviewed-by: Pavel Machek <pavel@denx.de> Signed-off-by: Chao Yu <chao@kernel.org> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-26f2fs: compress: disallow disabling compress on non-empty compressed fileHyeong-Jun Kim1-2/+1
[ Upstream commit 02d58cd253d7536c412993573fc6b3b4454960eb ] Compresse file and normal file has differ in i_addr addressing, specifically addrs per inode/block. So, we will face data loss, if we disable the compression flag on non-empty files. Therefore we should disallow not only enabling but disabling the compression flag on non-empty files. Fixes: 4c8ff7095bef ("f2fs: support data compression") Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Hyeong-Jun Kim <hj514.kim@samsung.com> Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-26f2fs: fix to use WHINT_MODEKeoseong Park1-1/+1
[ Upstream commit 011e0868e0cf1237675b22e36fffa958fb08f46e ] Since active_logs can be set to 2 or 4 or NR_CURSEG_PERSIST_TYPE(6), it cannot be set to NR_CURSEG_TYPE(8). That is, whint_mode is always off. Therefore, the condition is changed from NR_CURSEG_TYPE to NR_CURSEG_PERSIST_TYPE. Cc: Chao Yu <chao@kernel.org> Fixes: d0b9e42ab615 (f2fs: introduce inmem curseg) Reported-by: tanghuan <tanghuan@vivo.com> Signed-off-by: Keoseong Park <keosung.park@samsung.com> Signed-off-by: Fengnan Chang <changfengnan@vivo.com> Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-21erofs: fix unsafe pagevec reuse of hooked pclustersGao Xiang2-9/+17
commit 86432a6dca9bed79111990851df5756d3eb5f57c upstream. There are pclusters in runtime marked with Z_EROFS_PCLUSTER_TAIL before actual I/O submission. Thus, the decompression chain can be extended if the following pcluster chain hooks such tail pcluster. As the related comment mentioned, if some page is made of a hooked pcluster and another followed pcluster, it can be reused for in-place I/O (since I/O should be submitted anyway): _______________________________________________________________ | tail (partial) page | head (partial) page | |_____PRIMARY_HOOKED___|____________PRIMARY_FOLLOWED____________| However, it's by no means safe to reuse as pagevec since if such PRIMARY_HOOKED pclusters finally move into bypass chain without I/O submission. It's somewhat hard to reproduce with LZ4 and I just found it (general protection fault) by ro_fsstressing a LZMA image for long time. I'm going to actively clean up related code together with multi-page folio adaption in the next few months. Let's address it directly for easier backporting for now. Call trace for reference: z_erofs_decompress_pcluster+0x10a/0x8a0 [erofs] z_erofs_decompress_queue.isra.36+0x3c/0x60 [erofs] z_erofs_runqueue+0x5f3/0x840 [erofs] z_erofs_readahead+0x1e8/0x320 [erofs] read_pages+0x91/0x270 page_cache_ra_unbounded+0x18b/0x240 filemap_get_pages+0x10a/0x5f0 filemap_read+0xa9/0x330 new_sync_read+0x11b/0x1a0 vfs_read+0xf1/0x190 Link: https://lore.kernel.org/r/20211103182006.4040-1-xiang@kernel.org Fixes: 3883a79abd02 ("staging: erofs: introduce VLE decompression support") Cc: <stable@vger.kernel.org> # 4.19+ Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-21erofs: remove the occupied parameter from z_erofs_pagevec_enqueue()Yue Hu2-7/+2
commit 7dea3de7d384f4c8156e8bd93112ba6db1eb276c upstream. No any behavior to variable occupied in z_erofs_attach_page() which is only caller to z_erofs_pagevec_enqueue(). Link: https://lore.kernel.org/r/20210419102623.2015-1-zbestahu@gmail.com Signed-off-by: Yue Hu <huyue2@yulong.com> Reviewed-by: Gao Xiang <xiang@kernel.org> Signed-off-by: Gao Xiang <xiang@kernel.org> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-18f2fs: should use GFP_NOFS for directory inodesJaegeuk Kim2-2/+2
commit 92d602bc7177325e7453189a22e0c8764ed3453e upstream. We use inline_dentry which requires to allocate dentry page when adding a link. If we allow to reclaim memory from filesystem, we do down_read(&sbi->cp_rwsem) twice by f2fs_lock_op(). I think this should be okay, but how about stopping the lockdep complaint [1]? f2fs_create() - f2fs_lock_op() - f2fs_do_add_link() - __f2fs_find_entry - f2fs_get_read_data_page() -> kswapd - shrink_node - f2fs_evict_inode - f2fs_lock_op() [1] fs_reclaim ){+.+.}-{0:0} : kswapd0: lock_acquire+0x114/0x394 kswapd0: __fs_reclaim_acquire+0x40/0x50 kswapd0: prepare_alloc_pages+0x94/0x1ec kswapd0: __alloc_pages_nodemask+0x78/0x1b0 kswapd0: pagecache_get_page+0x2e0/0x57c kswapd0: f2fs_get_read_data_page+0xc0/0x394 kswapd0: f2fs_find_data_page+0xa4/0x23c kswapd0: find_in_level+0x1a8/0x36c kswapd0: __f2fs_find_entry+0x70/0x100 kswapd0: f2fs_do_add_link+0x84/0x1ec kswapd0: f2fs_mkdir+0xe4/0x1e4 kswapd0: vfs_mkdir+0x110/0x1c0 kswapd0: do_mkdirat+0xa4/0x160 kswapd0: __arm64_sys_mkdirat+0x24/0x34 kswapd0: el0_svc_common.llvm.17258447499513131576+0xc4/0x1e8 kswapd0: do_el0_svc+0x28/0xa0 kswapd0: el0_svc+0x24/0x38 kswapd0: el0_sync_handler+0x88/0xec kswapd0: el0_sync+0x1c0/0x200 kswapd0: -> #1 ( &sbi->cp_rwsem ){++++}-{3:3} : kswapd0: lock_acquire+0x114/0x394 kswapd0: down_read+0x7c/0x98 kswapd0: f2fs_do_truncate_blocks+0x78/0x3dc kswapd0: f2fs_truncate+0xc8/0x128 kswapd0: f2fs_evict_inode+0x2b8/0x8b8 kswapd0: evict+0xd4/0x2f8 kswapd0: iput+0x1c0/0x258 kswapd0: do_unlinkat+0x170/0x2a0 kswapd0: __arm64_sys_unlinkat+0x4c/0x68 kswapd0: el0_svc_common.llvm.17258447499513131576+0xc4/0x1e8 kswapd0: do_el0_svc+0x28/0xa0 kswapd0: el0_svc+0x24/0x38 kswapd0: el0_sync_handler+0x88/0xec kswapd0: el0_sync+0x1c0/0x200 Cc: stable@vger.kernel.org Fixes: bdbc90fa55af ("f2fs: don't put dentry page in pagecache into highmem") Reviewed-by: Chao Yu <chao@kernel.org> Reviewed-by: Stanley Chu <stanley.chu@mediatek.com> Reviewed-by: Light Hsieh <light.hsieh@mediatek.com> Tested-by: Light Hsieh <light.hsieh@mediatek.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-18NFSv4: Fix a regression in nfs_set_open_stateid_locked()Trond Myklebust1-7/+8
[ Upstream commit 01d29f87fcfef38d51ce2b473981a5c1e861ac0a ] If we already hold open state on the client, yet the server gives us a completely different stateid to the one we already hold, then we currently treat it as if it were an out-of-sequence update, and wait for 5 seconds for other updates to come in. This commit fixes the behaviour so that we immediately start processing of the new stateid, and then leave it to the call to nfs4_test_and_free_stateid() to decide what to do with the old stateid. Fixes: b4868b44c562 ("NFSv4: Wait for stateid updates after CLOSE/OPEN_DOWNGRADE") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18Fix user namespace leakAlexey Gladkov1-1/+1
[ Upstream commit d5f458a979650e5ed37212f6134e4ee2b28cb6ed ] Fixes: 61ca2c4afd9d ("NFS: Only reference user namespace from nfs4idmap struct instead of cred") Signed-off-by: Alexey Gladkov <legion@kernel.org> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18NFS: Fix an Oops in pnfs_mark_request_commit()Trond Myklebust1-1/+1
[ Upstream commit f0caea8882a7412a2ad4d8274f0280cdf849c9e2 ] Olga reports seeing the following Oops when doing O_DIRECT writes to a pNFS flexfiles server: Oops: 0000 [#1] SMP PTI CPU: 1 PID: 234186 Comm: kworker/u8:1 Not tainted 5.15.0-rc4+ #4 Hardware name: Red Hat KVM/RHEL-AV, BIOS 1.13.0-2.module+el8.3.0+7353+9de0a3cc 04/01/2014 Workqueue: nfsiod rpc_async_release [sunrpc] RIP: 0010:nfs_mark_request_commit+0x12/0x30 [nfs] Code: ff ff be 03 00 00 00 e8 ac 34 83 eb e9 29 ff ff ff e8 22 bc d7 eb 66 90 0f 1f 44 00 00 48 85 f6 74 16 48 8b 42 10 48 8b 40 18 <48> 8b 40 18 48 85 c0 74 05 e9 70 fc 15 ec 48 89 d6 e9 68 ed ff ff RSP: 0018:ffffa82f0159fe00 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff8f3393141880 RCX: 0000000000000000 RDX: ffffa82f0159fe08 RSI: ffff8f3381252500 RDI: ffff8f3393141880 RBP: ffff8f33ac317c00 R08: 0000000000000000 R09: ffff8f3487724cb0 R10: 0000000000000008 R11: 0000000000000001 R12: 0000000000000001 R13: ffff8f3485bccee0 R14: ffff8f33ac317c10 R15: ffff8f33ac317cd8 FS: 0000000000000000(0000) GS:ffff8f34fbc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000018 CR3: 0000000122120006 CR4: 0000000000770ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: nfs_direct_write_completion+0x13b/0x250 [nfs] rpc_free_task+0x39/0x60 [sunrpc] rpc_async_release+0x29/0x40 [sunrpc] process_one_work+0x1ce/0x370 worker_thread+0x30/0x380 ? process_one_work+0x370/0x370 kthread+0x11a/0x140 ? set_kthread_struct+0x40/0x40 ret_from_fork+0x22/0x30 Reported-by: Olga Kornievskaia <aglo@umich.edu> Fixes: 9c455a8c1e14 ("NFS/pNFS: Clean up pNFS commit operations") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18NFS: Fix up commit deadlocksTrond Myklebust3-6/+7
[ Upstream commit 133a48abf6ecc535d7eddc6da1c3e4c972445882 ] If O_DIRECT bumps the commit_info rpcs_out field, then that could lead to fsync() hangs. The fix is to ensure that O_DIRECT calls nfs_commit_end(). Fixes: 723c921e7dfc ("sched/wait, fs/nfs: Convert wait_on_atomic_t() usage to the new wait_var_event() API") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18fs: orangefs: fix error return code of orangefs_revalidate_lookup()Jia-Ju Bai1-1/+3
[ Upstream commit 4c2b46c824a78fc8190d8eafaaea5a9078fe7479 ] When op_alloc() returns NULL to new_op, no error return code of orangefs_revalidate_lookup() is assigned. To fix this bug, ret is assigned with -ENOMEM in this case. Fixes: 8bb8aefd5afb ("OrangeFS: Change almost all instances of the string PVFS2 to OrangeFS.") Reported-by: TOTE Robot <oslab@tsinghua.edu.cn> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> Signed-off-by: Mike Marshall <hubcap@omnibond.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18NFS: Fix deadlocks in nfs_scan_commit_list()Trond Myklebust1-15/+2
[ Upstream commit 64a93dbf25d3a1368bb58ddf0f61d0a92d7479e3 ] Partially revert commit 2ce209c42c01 ("NFS: Wait for requests that are locked on the commit list"), since it can lead to deadlocks between commit requests and nfs_join_page_group(). For now we should assume that any locked requests on the commit list are either about to be removed and committed by another task, or the writes they describe are about to be retransmitted. In either case, we should not need to worry. Fixes: 2ce209c42c01 ("NFS: Wait for requests that are locked on the commit list") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18pnfs/flexfiles: Fix misplaced barrier in nfs4_ff_layout_prepare_dsBaptiste Lepers2-4/+4
[ Upstream commit a2915fa06227b056a8f9b0d79b61dca08ad5cfc6 ] _nfs4_pnfs_v3/v4_ds_connect do some work smp_wmb ds->ds_clp = clp; And nfs4_ff_layout_prepare_ds currently does smp_rmb if(ds->ds_clp) ... This patch places the smp_rmb after the if. This ensures that following reads only happen once nfs4_ff_layout_prepare_ds has checked that data has been properly initialized. Fixes: d67ae825a59d6 ("pnfs/flexfiles: Add the FlexFile Layout Driver") Signed-off-by: Baptiste Lepers <baptiste.lepers@gmail.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18NFS: Fix dentry verifier racesTrond Myklebust1-4/+3
[ Upstream commit cec08f452a687fce9dfdf47946d00a1d12a8bec5 ] If the directory changed while we were revalidating the dentry, then don't update the dentry verifier. There is no value in setting the verifier to an older value, and we could end up overwriting a more up to date verifier from a parallel revalidation. Fixes: efeda80da38d ("NFSv4: Fix revalidation of dentries with delegations") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Tested-by: Benjamin Coddington <bcodding@redhat.com> Reviewed-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18JFS: fix memleak in jfs_mountDongliang Mu1-29/+22
[ Upstream commit c48a14dca2cb57527dde6b960adbe69953935f10 ] In jfs_mount, when diMount(ipaimap2) fails, it goes to errout35. However, the following code does not free ipaimap2 allocated by diReadSpecial. Fix this by refactoring the error handling code of jfs_mount. To be specific, modify the lable name and free ipaimap2 when the above error ocurrs. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com> Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18erofs: don't trigger WARN() when decompression failsGao Xiang1-1/+0
[ Upstream commit a0961f351d82d43ab0b845304caa235dfe249ae9 ] syzbot reported a WARNING [1] due to corrupted compressed data. As Dmitry said, "If this is not a kernel bug, then the code should not use WARN. WARN if for kernel bugs and is recognized as such by all testing systems and humans." [1] https://lore.kernel.org/r/000000000000b3586105cf0ff45e@google.com Link: https://lore.kernel.org/r/20211025074311.130395-1-hsiangkao@linux.alibaba.com Cc: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Chao Yu <chao@kernel.org> Reported-by: syzbot+d8aaffc3719597e8cfb4@syzkaller.appspotmail.com Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18btrfs: do not take the uuid_mutex in btrfs_rm_deviceJosef Bacik1-5/+5
[ Upstream commit 8ef9dc0f14ba6124c62547a4fdc59b163d8b864e ] We got the following lockdep splat while running fstests (specifically btrfs/003 and btrfs/020 in a row) with the new rc. This was uncovered by 87579e9b7d8d ("loop: use worker per cgroup instead of kworker") which converted loop to using workqueues, which comes with lockdep annotations that don't exist with kworkers. The lockdep splat is as follows: WARNING: possible circular locking dependency detected 5.14.0-rc2-custom+ #34 Not tainted ------------------------------------------------------ losetup/156417 is trying to acquire lock: ffff9c7645b02d38 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x84/0x600 but task is already holding lock: ffff9c7647395468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x650 [loop] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&lo->lo_mutex){+.+.}-{3:3}: __mutex_lock+0xba/0x7c0 lo_open+0x28/0x60 [loop] blkdev_get_whole+0x28/0xf0 blkdev_get_by_dev.part.0+0x168/0x3c0 blkdev_open+0xd2/0xe0 do_dentry_open+0x163/0x3a0 path_openat+0x74d/0xa40 do_filp_open+0x9c/0x140 do_sys_openat2+0xb1/0x170 __x64_sys_openat+0x54/0x90 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #4 (&disk->open_mutex){+.+.}-{3:3}: __mutex_lock+0xba/0x7c0 blkdev_get_by_dev.part.0+0xd1/0x3c0 blkdev_get_by_path+0xc0/0xd0 btrfs_scan_one_device+0x52/0x1f0 [btrfs] btrfs_control_ioctl+0xac/0x170 [btrfs] __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #3 (uuid_mutex){+.+.}-{3:3}: __mutex_lock+0xba/0x7c0 btrfs_rm_device+0x48/0x6a0 [btrfs] btrfs_ioctl+0x2d1c/0x3110 [btrfs] __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #2 (sb_writers#11){.+.+}-{0:0}: lo_write_bvec+0x112/0x290 [loop] loop_process_work+0x25f/0xcb0 [loop] process_one_work+0x28f/0x5d0 worker_thread+0x55/0x3c0 kthread+0x140/0x170 ret_from_fork+0x22/0x30 -> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}: process_one_work+0x266/0x5d0 worker_thread+0x55/0x3c0 kthread+0x140/0x170 ret_from_fork+0x22/0x30 -> #0 ((wq_completion)loop0){+.+.}-{0:0}: __lock_acquire+0x1130/0x1dc0 lock_acquire+0xf5/0x320 flush_workqueue+0xae/0x600 drain_workqueue+0xa0/0x110 destroy_workqueue+0x36/0x250 __loop_clr_fd+0x9a/0x650 [loop] lo_ioctl+0x29d/0x780 [loop] block_ioctl+0x3f/0x50 __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x3b/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/156417: #0: ffff9c7647395468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x650 [loop] stack backtrace: CPU: 8 PID: 156417 Comm: losetup Not tainted 5.14.0-rc2-custom+ #34 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 Call Trace: dump_stack_lvl+0x57/0x72 check_noncircular+0x10a/0x120 __lock_acquire+0x1130/0x1dc0 lock_acquire+0xf5/0x320 ? flush_workqueue+0x84/0x600 flush_workqueue+0xae/0x600 ? flush_workqueue+0x84/0x600 drain_workqueue+0xa0/0x110 destroy_workqueue+0x36/0x250 __loop_clr_fd+0x9a/0x650 [loop] lo_ioctl+0x29d/0x780 [loop] ? __lock_acquire+0x3a0/0x1dc0 ? update_dl_rq_load_avg+0x152/0x360 ? lock_is_held_type+0xa5/0x120 ? find_held_lock.constprop.0+0x2b/0x80 block_ioctl+0x3f/0x50 __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f645884de6b Usually the uuid_mutex exists to protect the fs_devices that map together all of the devices that match a specific uuid. In rm_device we're messing with the uuid of a device, so it makes sense to protect that here. However in doing that it pulls in a whole host of lockdep dependencies, as we call mnt_may_write() on the sb before we grab the uuid_mutex, thus we end up with the dependency chain under the uuid_mutex being added under the normal sb write dependency chain, which causes problems with loop devices. We don't need the uuid mutex here however. If we call btrfs_scan_one_device() before we scratch the super block we will find the fs_devices and not find the device itself and return EBUSY because the fs_devices is open. If we call it after the scratch happens it will not appear to be a valid btrfs file system. We do not need to worry about other fs_devices modifying operations here because we're protected by the exclusive operations locking. So drop the uuid_mutex here in order to fix the lockdep splat. A more detailed explanation from the discussion: We are worried about rm and scan racing with each other, before this change we'll zero the device out under the UUID mutex so when scan does run it'll make sure that it can go through the whole device scan thing without rm messing with us. We aren't worried if the scratch happens first, because the result is we don't think this is a btrfs device and we bail out. The only case we are concerned with is we scratch _after_ scan is able to read the superblock and gets a seemingly valid super block, so lets consider this case. Scan will call device_list_add() with the device we're removing. We'll call find_fsid_with_metadata_uuid() and get our fs_devices for this UUID. At this point we lock the fs_devices->device_list_mutex. This is what protects us in this case, but we have two cases here. 1. We aren't to the device removal part of the RM. We found our device, and device name matches our path, we go down and we set total_devices to our super number of devices, which doesn't affect anything because we haven't done the remove yet. 2. We are past the device removal part, which is protected by the device_list_mutex. Scan doesn't find the device, it goes down and does the if (fs_devices->opened) return -EBUSY; check and we bail out. Nothing about this situation is ideal, but the lockdep splat is real, and the fix is safe, tho admittedly a bit scary looking. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> [ copy more from the discussion ] Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18btrfs: reflink: initialize return value to 0 in btrfs_extent_same()Sidong Yang1-1/+1
[ Upstream commit 44bee215f72f13874c0e734a0712c2e3264c0108 ] Fix a warning reported by smatch that ret could be returned without initialized. The dedupe operations are supposed to to return 0 for a 0 length range but the caller does not pass olen == 0. To keep this behaviour and also fix the warning initialize ret to 0. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Sidong Yang <realwakka@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18gfs2: Fix glock_hash_walk bugsAndreas Gruenbacher1-10/+12
[ Upstream commit 7427f3bb49d81525b7dd1d0f7c5f6bbc752e6f0e ] So far, glock_hash_walk took a reference on each glock it iterated over, and it was the examiner's responsibility to drop those references. Dropping the final reference to a glock can sleep and the examiners are called in a RCU critical section with spin locks held, so examiners that didn't need the extra reference had to drop it asynchronously via gfs2_glock_queue_put or similar. This wasn't done correctly in thaw_glock which did call gfs2_glock_put, and not at all in dump_glock_func. Change glock_hash_walk to not take glock references at all. That way, the examiners that don't need them won't have to bother with slow asynchronous puts, and the examiners that do need references can take them themselves. Reported-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: Andreas Gruenbacher <agru