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2021-09-08coredump: fix memleak in dump_vma_snapshot()QiuXi1-1/+3
dump_vma_snapshot() allocs memory for *vma_meta, when dump_vma_snapshot() returns -EFAULT, the memory will be leaked, so we free it correctly. Link: https://lkml.kernel.org/r/20210810020441.62806-1-qiuxi1@huawei.com Fixes: a07279c9a8cd7 ("binfmt_elf, binfmt_elf_fdpic: use a VMA list snapshot") Signed-off-by: QiuXi <qiuxi1@huawei.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jann Horn <jannh@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-08fs/coredump.c: log if a core dump is aborted due to changed file permissionsDavid Oberhollenzer1-2/+9
For obvious security reasons, a core dump is aborted if the filesystem cannot preserve ownership or permissions of the dump file. This affects filesystems like e.g. vfat, but also something like a 9pfs share in a Qemu test setup, running as a regular user, depending on the security model used. In those cases, the result is an empty core file and a confused user. To hopefully save other people a lot of time figuring out the cause, this patch adds a simple log message for those specific cases. [akpm@linux-foundation.org: s/|%s/%s/ in printk text] Link: https://lkml.kernel.org/r/20210701233151.102720-1-david.oberhollenzer@sigma-star.at Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-08nilfs2: use refcount_dec_and_lock() to fix potential UAFZhen Lei1-5/+4
When the refcount is decreased to 0, the resource reclamation branch is entered. Before CPU0 reaches the race point (1), CPU1 may obtain the spinlock and traverse the rbtree to find 'root', see nilfs_lookup_root(). Although CPU1 will call refcount_inc() to increase the refcount, it is obviously too late. CPU0 will release 'root' directly, CPU1 then accesses 'root' and triggers UAF. Use refcount_dec_and_lock() to ensure that both the operations of decrease refcount to 0 and link deletion are lock protected eliminates this risk. CPU0 CPU1 nilfs_put_root(): <-------- (1) spin_lock(&nilfs->ns_cptree_lock); rb_erase(&root->rb_node, &nilfs->ns_cptree); spin_unlock(&nilfs->ns_cptree_lock); kfree(root); <-------- use-after-free refcount_t: underflow; use-after-free. WARNING: CPU: 2 PID: 9476 at lib/refcount.c:28 \ refcount_warn_saturate+0x1cf/0x210 lib/refcount.c:28 Modules linked in: CPU: 2 PID: 9476 Comm: syz-executor.0 Not tainted 5.10.45-rc1+ #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), ... RIP: 0010:refcount_warn_saturate+0x1cf/0x210 lib/refcount.c:28 ... ... Call Trace: __refcount_sub_and_test include/linux/refcount.h:283 [inline] __refcount_dec_and_test include/linux/refcount.h:315 [inline] refcount_dec_and_test include/linux/refcount.h:333 [inline] nilfs_put_root+0xc1/0xd0 fs/nilfs2/the_nilfs.c:795 nilfs_segctor_destroy fs/nilfs2/segment.c:2749 [inline] nilfs_detach_log_writer+0x3fa/0x570 fs/nilfs2/segment.c:2812 nilfs_put_super+0x2f/0xf0 fs/nilfs2/super.c:467 generic_shutdown_super+0xcd/0x1f0 fs/super.c:464 kill_block_super+0x4a/0x90 fs/super.c:1446 deactivate_locked_super+0x6a/0xb0 fs/super.c:335 deactivate_super+0x85/0x90 fs/super.c:366 cleanup_mnt+0x277/0x2e0 fs/namespace.c:1118 __cleanup_mnt+0x15/0x20 fs/namespace.c:1125 task_work_run+0x8e/0x110 kernel/task_work.c:151 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:164 [inline] exit_to_user_mode_prepare+0x13c/0x170 kernel/entry/common.c:191 syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:266 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x44/0xa9 There is no reproduction program, and the above is only theoretical analysis. Link: https://lkml.kernel.org/r/1629859428-5906-1-git-send-email-konishi.ryusuke@gmail.com Fixes: ba65ae4729bf ("nilfs2: add checkpoint tree to nilfs object") Link: https://lkml.kernel.org/r/20210723012317.4146-1-thunder.leizhen@huawei.com Signed-off-by: Zhen Lei <thunder.leizhen@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>
2021-09-08nilfs2: fix memory leak in nilfs_sysfs_delete_snapshot_groupNanyong Sun1-1/+1
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>
2021-09-08nilfs2: fix memory leak in nilfs_sysfs_create_snapshot_groupNanyong Sun1-2/+2
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>
2021-09-08nilfs2: fix memory leak in nilfs_sysfs_delete_##name##_groupNanyong Sun1-1/+1
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>
2021-09-08nilfs2: fix memory leak in nilfs_sysfs_create_##name##_groupNanyong Sun1-2/+2
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>
2021-09-08nilfs2: fix NULL pointer in nilfs_##name##_attr_releaseNanyong Sun1-5/+3
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>
2021-09-08nilfs2: fix memory leak in nilfs_sysfs_create_device_groupNanyong Sun1-4/+2
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>
2021-09-08fs/epoll: use a per-cpu counter for user's watches countNicholas Piggin1-8/+10
This counter tracks the number of watches a user has, to compare against the 'max_user_watches' limit. This causes a scalability bottleneck on SPECjbb2015 on large systems as there is only one user. Changing to a per-cpu counter increases throughput of the benchmark by about 30% on a 16-socket, > 1000 thread system. [rdunlap@infradead.org: fix build errors in kernel/user.c when CONFIG_EPOLL=n] [npiggin@gmail.com: move ifdefs into wrapper functions, slightly improve panic message] Link: https://lkml.kernel.org/r/1628051945.fens3r99ox.astroid@bobo.none [akpm@linux-foundation.org: tweak user_epoll_alloc(), per Guenter] Link: https://lkml.kernel.org/r/20210804191421.GA1900577@roeck-us.net Link: https://lkml.kernel.org/r/20210802032013.2751916-1-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reported-by: Anton Blanchard <anton@ozlabs.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-08connector: send event on write to /proc/[pid]/commOhhoon Kwon1-1/+4
While comm change event via prctl has been reported to proc connector by 'commit f786ecba4158 ("connector: add comm change event report to proc connector")', connector listeners were missing comm changes by explicit writes on /proc/[pid]/comm. Let explicit writes on /proc/[pid]/comm report to proc connector. Link: https://lkml.kernel.org/r/20210701133458epcms1p68e9eb9bd0eee8903ba26679a37d9d960@epcms1p6 Signed-off-by: Ohhoon Kwon <ohoono.kwon@samsung.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: David S. Miller <davem@davemloft.net> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-08proc: stop using seq_get_buf in proc_task_nameChristoph Hellwig1-14/+4
Use seq_escape_str and seq_printf instead of poking holes into the seq_file abstraction. Link: https://lkml.kernel.org/r/20210810151945.1795567-1-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-08-26Merge tag 'ceph-for-5.14-rc8' of git://github.com/ceph/ceph-clientLinus Torvalds5-15/+27
Pull ceph fixes from Ilya Dryomov: "Two memory management fixes for the filesystem" * tag 'ceph-for-5.14-rc8' of git://github.com/ceph/ceph-client: ceph: fix possible null-pointer dereference in ceph_mdsmap_decode() ceph: correctly handle releasing an embedded cap flush
2021-08-26Merge tag 'for-5.14-rc7-tag' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fix from David Sterba: "One more fix that I think qualifies for a late merge. It's a revert of a one-liner fix that meanwhile got backported to stable kernels and we got reports from users. The broken fix prevents creating compressed inline extents, which could be noticeable on space consumption. Technically it's a regression as the patch was merged in 5.14-rc1 but got propagated to several stable kernels and has higher exposure than a 'typical' development cycle bug" * tag 'for-5.14-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: Revert "btrfs: compression: don't try to compress if we don't have enough pages"
2021-08-25pipe: do FASYNC notifications for every pipe IO, not just state changesLinus Torvalds1-12/+8
It turns out that the SIGIO/FASYNC situation is almost exactly the same as the EPOLLET case was: user space really wants to be notified after every operation. Now, in a perfect world it should be sufficient to only notify user space on "state transitions" when the IO state changes (ie when a pipe goes from unreadable to readable, or from unwritable to writable). User space should then do as much as possible - fully emptying the buffer or what not - and we'll notify it again the next time the state changes. But as with EPOLLET, we have at least one case (stress-ng) where the kernel sent SIGIO due to the pipe being marked for asynchronous notification, but the user space signal handler then didn't actually necessarily read it all before returning (it read more than what was written, but since there could be multiple writes, it could leave data pending). The user space code then expected to get another SIGIO for subsequent writes - even though the pipe had been readable the whole time - and would only then read more. This is arguably a user space bug - and Colin King already fixed the stress-ng code in question - but the kernel regression rules are clear: it doesn't matter if kernel people think that user space did something silly and wrong. What matters is that it used to work. So if user space depends on specific historical kernel behavior, it's a regression when that behavior changes. It's on us: we were silly to have that non-optimal historical behavior, and our old kernel behavior was what user space was tested against. Because of how the FASYNC notification was tied to wakeup behavior, this was first broken by commits f467a6a66419 and 1b6b26ae7053 ("pipe: fix and clarify pipe read/write wakeup logic"), but at the time it seems nobody noticed. Probably because the stress-ng problem case ends up being timing-dependent too. It was then unwittingly fixed by commit 3a34b13a88ca ("pipe: make pipe writes always wake up readers") only to be broken again when by commit 3b844826b6c6 ("pipe: avoid unnecessary EPOLLET wakeups under normal loads"). And at that point the kernel test robot noticed the performance refression in the stress-ng.sigio.ops_per_sec case. So the "Fixes" tag below is somewhat ad hoc, but it matches when the issue was noticed. Fix it for good (knock wood) by simply making the kill_fasync() case separate from the wakeup case. FASYNC is quite rare, and we clearly shouldn't even try to use the "avoid unnecessary wakeups" logic for it. Link: https://lore.kernel.org/lkml/20210824151337.GC27667@xsang-OptiPlex-9020/ Fixes: 3b844826b6c6 ("pipe: avoid unnecessary EPOLLET wakeups under normal loads") Reported-by: kernel test robot <oliver.sang@intel.com> Tested-by: Oliver Sang <oliver.sang@intel.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Colin Ian King <colin.king@canonical.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-08-25ceph: fix possible null-pointer dereference in ceph_mdsmap_decode()Tuo Li1-3/+5
kcalloc() is called to allocate memory for m->m_info, and if it fails, ceph_mdsmap_destroy() behind the label out_err will be called: ceph_mdsmap_destroy(m); In ceph_mdsmap_destroy(), m->m_info is dereferenced through: kfree(m->m_info[i].export_targets); To fix this possible null-pointer dereference, check m->m_info before the for loop to free m->m_info[i].export_targets. [ jlayton: fix up whitespace damage only kfree(m->m_info) if it's non-NULL ] Reported-by: TOTE Robot <oslab@tsinghua.edu.cn> Signed-off-by: Tuo Li <islituo@gmail.com> Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2021-08-25ceph: correctly handle releasing an embedded cap flushXiubo Li4-12/+22
The ceph_cap_flush structures are usually dynamically allocated, but the ceph_cap_snap has an embedded one. When force umounting, the client will try to remove all the session caps. During this, it will free them, but that should not be done with the ones embedded in a capsnap. Fix this by adding a new boolean that indicates that the cap flush is embedded in a capsnap, and skip freeing it if that's set. At the same time, switch to using list_del_init() when detaching the i_list and g_list heads. It's possible for a forced umount to remove these objects but then handle_cap_flushsnap_ack() races in and does the list_del_init() again, corrupting memory. Cc: stable@vger.kernel.org URL: https://tracker.ceph.com/issues/52283 Signed-off-by: Xiubo Li <xiubli@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2021-08-25Revert "btrfs: compression: don't try to compress if we don't have enough pages"Qu Wenruo1-1/+1
This reverts commit f2165627319ffd33a6217275e5690b1ab5c45763. [BUG] It's no longer possible to create compressed inline extent after commit f2165627319f ("btrfs: compression: don't try to compress if we don't have enough pages"). [CAUSE] For compression code, there are several possible reasons we have a range that needs to be compressed while it's no more than one page. - Compressed inline write The data is always smaller than one sector and the test lacks the condition to properly recognize a non-inline extent. - Compressed subpage write For the incoming subpage compressed write support, we require page alignment of the delalloc range. And for 64K page size, we can compress just one page into smaller sectors. For those reasons, the requirement for the data to be more than one page is not correct, and is already causing regression for compressed inline data writeback. The idea of skipping one page to avoid wasting CPU time could be revisited in the future. [FIX] Fix it by reverting the offending commit. Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Link: https://lore.kernel.org/linux-btrfs/afa2742.c084f5d6.17b6b08dffc@tnonline.net Fixes: f2165627319f ("btrfs: compression: don't try to compress if we don't have enough pages") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-08-21Merge tag 'locks-v5.14' of ↵Linus Torvalds1-1/+5
git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux Pull mandatory file locking deprecation warning from Jeff Layton: "As discussed on the list, this patch just adds a new warning for folks who still have mandatory locking enabled and actually mount with '-o mand'. I'd like to get this in for v5.14 so we can push this out into stable kernels and hopefully reach folks who have mounts with -o mand. For now, I'm operating under the assumption that we'll fully remove this support in v5.15, but we can move that out if any legitimate users of this facility speak up between now and then" * tag 'locks-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux: fs: warn about impending deprecation of mandatory locks
2021-08-21Merge tag 'io_uring-5.14-2021-08-20' of git://git.kernel.dk/linux-blockLinus Torvalds1-6/+10
Pull io_uring fixes from Jens Axboe: "A few small fixes that should go into this release: - Fix never re-assigning an initial error value for io_uring_enter() for SQPOLL, if asked to do nothing - Fix xa_alloc_cycle() return value checking, for cases where we have wrapped around - Fix for a ctx pin issue introduced in this cycle (Pavel)" * tag 'io_uring-5.14-2021-08-20' of git://git.kernel.dk/linux-block: io_uring: fix xa_alloc_cycle() error return value check io_uring: pin ctx on fallback execution io_uring: only assign io_uring_enter() SQPOLL error in actual error case
2021-08-21fs: warn about impending deprecation of mandatory locksJeff Layton1-1/+5
We've had CONFIG_MANDATORY_FILE_LOCKING since 2015 and a lot of distros have disabled it. Warn the stragglers that still use "-o mand" that we'll be dropping support for that mount option. Cc: stable@vger.kernel.org Signed-off-by: Jeff Layton <jlayton@kernel.org>
2021-08-20io_uring: fix xa_alloc_cycle() error return value checkJens Axboe1-4/+5
We currently check for ret != 0 to indicate error, but '1' is a valid return and just indicates that the allocation succeeded with a wrap. Correct the check to be for < 0, like it was before the xarray conversion. Cc: stable@vger.kernel.org Fixes: 61cf93700fe6 ("io_uring: Convert personality_idr to XArray") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-18Merge tag 'for-5.14-rc6-tag' of ↵Linus Torvalds1-2/+8
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fix from David Sterba: "One more fix for cross-rename, adding a missing check for directory and subvolume, this could lead to a crash" * tag 'for-5.14-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: prevent rename2 from exchanging a subvol with a directory from different parents
2021-08-18pipe: avoid unnecessary EPOLLET wakeups under normal loadsLinus Torvalds1-6/+9
I had forgotten just how sensitive hackbench is to extra pipe wakeups, and commit 3a34b13a88ca ("pipe: make pipe writes always wake up readers") ended up causing a quite noticeable regression on larger machines. Now, hackbench isn't necessarily a hugely meaningful benchmark, and it's not clear that this matters in real life all that much, but as Mel points out, it's used often enough when comparing kernels and so the performance regression shows up like a sore thumb. It's easy enough to fix at least for the common cases where pipes are used purely for data transfer, and you never have any exciting poll usage at all. So set a special 'poll_usage' flag when there is polling activity, and make the ugly "EPOLLET has crazy legacy expectations" semantics explicit to only that case. I would love to limit it to just the broken EPOLLET case, but the pipe code can't see the difference between epoll and regular select/poll, so any non-read/write waiting will trigger the extra wakeup behavior. That is sufficient for at least the hackbench case. Apart from making the odd extra wakeup cases more explicitly about EPOLLET, this also makes the extra wakeup be at the _end_ of the pipe write, not at the first write chunk. That is actually much saner semantics (as much as you can call any of the legacy edge-triggered expectations for EPOLLET "sane") since it means that you know the wakeup will happen once the write is done, rather than possibly in the middle of one. [ For stable people: I'm putting a "Fixes" tag on this, but I leave it up to you to decide whether you actually want to backport it or not. It likely has no impact outside of synthetic benchmarks - Linus ] Link: https://lore.kernel.org/lkml/20210802024945.GA8372@xsang-OptiPlex-9020/ Fixes: 3a34b13a88ca ("pipe: make pipe writes always wake up readers") Reported-by: kernel test robot <oliver.sang@intel.com> Tested-by: Sandeep Patil <sspatil@android.com> Tested-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-08-18io_uring: pin ctx on fallback executionPavel Begunkov1-0/+2
Pin ring in io_fallback_req_func() by briefly elevating ctx->refs in case any task_work handler touches ctx after releasing a request. Fixes: 9011bf9a13e3b ("io_uring: fix stuck fallback reqs") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/833a494713d235ec144284a9bbfe418df4f6b61c.1629235576.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-16btrfs: prevent rename2 from exchanging a subvol with a directory from ↵NeilBrown1-2/+8
different parents Cross-rename lacks a check when that would prevent exchanging a directory and subvolume from different parent subvolume. This causes data inconsistencies and is caught before commit by tree-checker, turning the filesystem to read-only. Calling the renameat2 with RENAME_EXCHANGE flags like renameat2(AT_FDCWD, namesrc, AT_FDCWD, namedest, (1 << 1)) on two paths: namesrc = dir1/subvol1/dir2 namedest = subvol2/subvol3 will cause key order problem with following write time tree-checker report: [1194842.307890] BTRFS critical (device loop1): corrupt leaf: root=5 block=27574272 slot=10 ino=258, invalid previous key objectid, have 257 expect 258 [1194842.322221] BTRFS info (device loop1): leaf 27574272 gen 8 total ptrs 11 free space 15444 owner 5 [1194842.331562] BTRFS info (device loop1): refs 2 lock_owner 0 current 26561 [1194842.338772] item 0 key (256 1 0) itemoff 16123 itemsize 160 [1194842.338793] inode generation 3 size 16 mode 40755 [1194842.338801] item 1 key (256 12 256) itemoff 16111 itemsize 12 [1194842.338809] item 2 key (256 84 2248503653) itemoff 16077 itemsize 34 [1194842.338817] dir oid 258 type 2 [1194842.338823] item 3 key (256 84 2363071922) itemoff 16043 itemsize 34 [1194842.338830] dir oid 257 type 2 [1194842.338836] item 4 key (256 96 2) itemoff 16009 itemsize 34 [1194842.338843] item 5 key (256 96 3) itemoff 15975 itemsize 34 [1194842.338852] item 6 key (257 1 0) itemoff 15815 itemsize 160 [1194842.338863] inode generation 6 size 8 mode 40755 [1194842.338869] item 7 key (257 12 256) itemoff 15801 itemsize 14 [1194842.338876] item 8 key (257 84 2505409169) itemoff 15767 itemsize 34 [1194842.338883] dir oid 256 type 2 [1194842.338888] item 9 key (257 96 2) itemoff 15733 itemsize 34 [1194842.338895] item 10 key (258 12 256) itemoff 15719 itemsize 14 [1194842.339163] BTRFS error (device loop1): block=27574272 write time tree block corruption detected [1194842.339245] ------------[ cut here ]------------ [1194842.443422] WARNING: CPU: 6 PID: 26561 at fs/btrfs/disk-io.c:449 csum_one_extent_buffer+0xed/0x100 [btrfs] [1194842.511863] CPU: 6 PID: 26561 Comm: kworker/u17:2 Not tainted 5.14.0-rc3-git+ #793 [1194842.511870] Hardware name: empty empty/S3993, BIOS PAQEX0-3 02/24/2008 [1194842.511876] Workqueue: btrfs-worker-high btrfs_work_helper [btrfs] [1194842.511976] RIP: 0010:csum_one_extent_buffer+0xed/0x100 [btrfs] [1194842.512068] RSP: 0018:ffffa2c284d77da0 EFLAGS: 00010282 [1194842.512074] RAX: 0000000000000000 RBX: 0000000000001000 RCX: ffff928867bd9978 [1194842.512078] RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff928867bd9970 [1194842.512081] RBP: ffff92876b958000 R08: 0000000000000001 R09: 00000000000c0003 [1194842.512085] R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 [1194842.512088] R13: ffff92875f989f98 R14: 0000000000000000 R15: 0000000000000000 [1194842.512092] FS: 0000000000000000(0000) GS:ffff928867a00000(0000) knlGS:0000000000000000 [1194842.512095] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [1194842.512099] CR2: 000055f5384da1f0 CR3: 0000000102fe4000 CR4: 00000000000006e0 [1194842.512103] Call Trace: [1194842.512128] ? run_one_async_free+0x10/0x10 [btrfs] [1194842.631729] btree_csum_one_bio+0x1ac/0x1d0 [btrfs] [1194842.631837] run_one_async_start+0x18/0x30 [btrfs] [1194842.631938] btrfs_work_helper+0xd5/0x1d0 [btrfs] [1194842.647482] process_one_work+0x262/0x5e0 [1194842.647520] worker_thread+0x4c/0x320 [1194842.655935] ? process_one_work+0x5e0/0x5e0 [1194842.655946] kthread+0x135/0x160 [1194842.655953] ? set_kthread_struct+0x40/0x40 [1194842.655965] ret_from_fork+0x1f/0x30 [1194842.672465] irq event stamp: 1729 [1194842.672469] hardirqs last enabled at (1735): [<ffffffffbd1104f5>] console_trylock_spinning+0x185/0x1a0 [1194842.672477] hardirqs last disabled at (1740): [<ffffffffbd1104cc>] console_trylock_spinning+0x15c/0x1a0 [1194842.672482] softirqs last enabled at (1666): [<ffffffffbdc002e1>] __do_softirq+0x2e1/0x50a [1194842.672491] softirqs last disabled at (1651): [<ffffffffbd08aab7>] __irq_exit_rcu+0xa7/0xd0 The corrupted data will not be written, and filesystem can be unmounted and mounted again (all changes since the last commit will be lost). Add the missing check for new_ino so that all non-subvolumes must reside under the same parent subvolume. There's an exception allowing to exchange two subvolumes from any parents as the directory representing a subvolume is only a logical link and does not have any other structures related to the parent subvolume, unlike files, directories etc, that are always in the inode namespace of the parent subvolume. Fixes: cdd1fedf8261 ("btrfs: add support for RENAME_EXCHANGE and RENAME_WHITEOUT") CC: stable@vger.kernel.org # 4.7+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-08-15Merge tag 'libnvdimm-fixes-5.14-rc6' of ↵Linus Torvalds2-5/+3
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm fixes from Dan Williams: "A couple of fixes for long standing bugs, a warning fixup, and some miscellaneous dax cleanups. The bugs were recently found due to new platforms looking to use the ACPI NFIT "virtual" device definition, and new error injection capabilities to trigger error responses to label area requests. Ira's cleanups have been long pending, I neglected to send them earlier, and see no harm in including them now. This has all appeared in -next with no reported issues. Summary: - Fix support for NFIT "virtual" ranges (BIOS-defined memory disks) - Fix recovery from failed label storage areas on NVDIMM devices - Miscellaneous cleanups from Ira's investigation of dax_direct_access paths preparing for stray-write protection" * tag 'libnvdimm-fixes-5.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: tools/testing/nvdimm: Fix missing 'fallthrough' warning libnvdimm/region: Fix label activation vs errors ACPI: NFIT: Fix support for virtual SPA ranges dax: Ensure errno is returned from dax_direct_access fs/dax: Clarify nr_pages to dax_direct_access() fs/fuse: Remove unneeded kaddr parameter
2021-08-14io_uring: only assign io_uring_enter() SQPOLL error in actual error caseJens Axboe1-2/+3
If an SQPOLL based ring is newly created and an application issues an io_uring_enter(2) system call on it, then we can return a spurious -EOWNERDEAD error. This happens because there's nothing to submit, and if the caller doesn't specify any other action, the initial error assignment of -EOWNERDEAD never gets overwritten. This causes us to return it directly, even if it isn't valid. Move the error assignment into the actual failure case instead. Cc: stable@vger.kernel.org Fixes: d9d05217cb69 ("io_uring: stop SQPOLL submit on creator's death") Reported-by: Sherlock Holo sherlockya@gmail.com Link: https://github.com/axboe/liburing/issues/413 Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-14Merge tag 'configfs-5.14' of git://git.infradead.org/users/hch/configfsLinus Torvalds1-12/+6
Pull configfs fix from Christoph Hellwig: - fix to revert to the historic write behavior (Bart Van Assche) * tag 'configfs-5.14' of git://git.infradead.org/users/hch/configfs: configfs: restore the kernel v5.13 text attribute write behavior
2021-08-14Merge tag '5.14-rc5-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds6-33/+80
Pull cifs fixes from Steve French: "Four CIFS/SMB3 Fixes, all for stable, two relating to deferred close, and one for the 'modefromsid' mount option (when 'idsfromsid' not specified)" * tag '5.14-rc5-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6: cifs: Call close synchronously during unlink/rename/lease break. cifs: Handle race conditions during rename cifs: use the correct max-length for dentry_path_raw() cifs: create sd context must be a multiple of 8
2021-08-14Merge tag 'io_uring-5.14-2021-08-13' of git://git.kernel.dk/linux-blockLinus Torvalds2-36/+48
Pull io_uring fixes from Jens Axboe: "A bit bigger than the previous weeks, but mostly just a few stable bound fixes. In detail: - Followup fixes to patches from last week for io-wq, turns out they weren't complete (Hao) - Two lockdep reported fixes out of the RT camp (me) - Sync the io_uring-cp example with liburing, as a few bug fixes never made it to the kernel carried version (me) - SQPOLL related TIF_NOTIFY_SIGNAL fix (Nadav) - Use WRITE_ONCE() when writing sq flags (Nadav) - io_rsrc_put_work() deadlock fix (Pavel)" * tag 'io_uring-5.14-2021-08-13' of git://git.kernel.dk/linux-block: tools/io_uring/io_uring-cp: sync with liburing example io_uring: fix ctx-exit io_rsrc_put_work() deadlock io_uring: drop ctx->uring_lock before flushing work item io-wq: fix IO_WORKER_F_FIXED issue in create_io_worker() io-wq: fix bug of creating io-wokers unconditionally io_uring: rsrc ref lock needs to be IRQ safe io_uring: Use WRITE_ONCE() when writing to sq_flags io_uring: clear TIF_NOTIFY_SIGNAL when running task work
2021-08-13Merge tag 'ceph-for-5.14-rc6' of git://github.com/ceph/ceph-clientLinus Torvalds4-28/+50
Pull ceph fixes from Ilya Dryomov: "A patch to avoid a soft lockup in ceph_check_delayed_caps() from Luis and a reference handling fix from Jeff that should address some memory corruption reports in the snaprealm area. Both marked for stable" * tag 'ceph-for-5.14-rc6' of git://github.com/ceph/ceph-client: ceph: take snap_empty_lock atomically with snaprealm refcount change ceph: reduce contention in ceph_check_delayed_caps()
2021-08-12Merge branch 'for-v5.14' of ↵Linus Torvalds2-12/+22
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull ucounts fix from Eric Biederman: "This fixes the ucount sysctls on big endian architectures. The counts were expanded to be longs instead of ints, and the sysctl code was overlooked, so only the low 32bit were being processed. On litte endian just processing the low 32bits is fine, but on 64bit big endian processing just the low 32bits results in the high order bits instead of the low order bits being processed and nothing works proper. This change took a little bit to mature as we have the SYSCTL_ZERO, and SYSCTL_INT_MAX macros that are only usable for sysctls operating on ints, but unfortunately are not obviously broken. Which resulted in the versions of this change working on big endian and not on little endian, because the int SYSCTL_ZERO when extended 64bit wound up being 0x100000000. So we only allowed values greater than 0x100000000 and less than 0faff. Which unfortunately broken everything that tried to set the sysctls. (First reported with the windows subsystem for linux). I have tested this on x86_64 64bit after first reproducing the problems with the earlier version of this change, and then verifying the problems do not exist when we use appropriate long min and max values for extra1 and extra2" * 'for-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: ucounts: add missing data type changes
2021-08-12cifs: Call close synchronously during unlink/rename/lease break.Rohith Surabattula3-30/+56
During unlink/rename/lease break, deferred work for close is scheduled immediately but in an asynchronous manner which might lead to race with actual(unlink/rename) commands. This change will schedule close synchronously which will avoid the race conditions with other commands. Signed-off-by: Rohith Surabattula <rohiths@microsoft.com> Reviewed-by: Shyam Prasad N <sprasad@microsoft.com> Cc: stable@vger.kernel.org # 5.13 Signed-off-by: Steve French <stfrench@microsoft.com>
2021-08-12cifs: Handle race conditions during renameRohith Surabattula2-7/+28
When rename is executed on directory which has files for which close is deferred, then rename will fail with EACCES. This patch will try to close all deferred files when EACCES is received and retry rename on a directory. Signed-off-by: Rohith Surabattula <rohiths@microsoft.com> Cc: stable@vger.kernel.org # 5.13 Reviewed-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2021-08-11Merge branch 'for-5.14/dax' into libnvdimm-fixesDan Williams2-5/+3
Pick up some small dax cleanups that make some of Ira's follow on work easier.
2021-08-10Merge tag 'ovl-fixes-5.14-rc6-v2' of ↵Linus Torvalds4-16/+80
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull overlayfs fixes from Miklos Szeredi: "Fix several bugs in overlayfs" * tag 'ovl-fixes-5.14-rc6-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: prevent private clone if bind mount is not allowed ovl: fix uninitialized pointer read in ovl_lookup_real_one() ovl: fix deadlock in splice write ovl: skip stale entries in merge dir cache iteration
2021-08-10cifs: use the correct max-length for dentry_path_raw()Ronnie Sahlberg1-1/+1
RHBZ: 1972502 PATH_MAX is 4096 but PAGE_SIZE can be >4096 on some architectures such as ppc and would thus write beyond the end of the actual object. Cc: <stable@vger.kernel.org> Reported-by: Xiaoli Feng <xifeng@redhat.com> Suggested-by: Brian foster <bfoster@redhat.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2021-08-10ovl: prevent private clone if bind mount is not allowedMiklos Szeredi1-14/+28
Add the following checks from __do_loopback() to clone_private_mount() as well: - verify that the mount is in the current namespace - verify that there are no locked children Reported-by: Alois Wohlschlager <alois1@gmx-topmail.de> Fixes: c771d683a62e ("vfs: introduce clone_private_mount()") Cc: <stable@vger.kernel.org> # v3.18 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-08-10ovl: fix uninitialized pointer read in ovl_lookup_real_one()Miklos Szeredi1-1/+1
One error path can result in release_dentry_name_snapshot() being called before "name" was initialized by take_dentry_name_snapshot(). Fix by moving the release_dentry_name_snapshot() to immediately after the only use. Reported-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-08-10ovl: fix deadlock in splice writeMiklos Szeredi1-1/+46
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>
2021-08-10ovl: skip stale entries in merge dir cache iterationAmir Goldstein1-0/+5
On the first getdents call, ovl_iterate() populates the readdir cache with a list of entries, but for upper entries with origin lower inode, p->ino remains zero. Following getdents calls traverse the readdir cache list and call ovl_cache_update_ino() for entries with zero p->ino to lookup the entry in the overlay and return d_ino that is consistent with st_ino. If the upper file was unlinked between the first getdents call and the getdents call that lists the file entry, ovl_cache_update_ino() will not find the entry and fall back to setting d_ino to the upper real st_ino, which is inconsistent with how this object was presented to users. Instead of listing a stale entry with inconsistent d_ino, simply skip the stale entry, which is better for users. xfstest overlay/077 is failing without this patch. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Link: https://lore.kernel.org/fstests/CAOQ4uxgR_cLnC_vdU5=seP3fwqVkuZM_-WfD6maFTMbMYq=a9w@mail.gmail.com/ Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-08-10io_uring: fix ctx-exit io_rsrc_put_work() deadlockPavel Begunkov1-7/+8
__io_rsrc_put_work() might need ->uring_lock, so nobody should wait for rsrc nodes holding the mutex. However, that's exactly what io_ring_ctx_free() does with io_wait_rsrc_data(). Split it into rsrc wait + dealloc, and move the first one out of the lock. Cc: stable@vger.kernel.org Fixes: b60c8dce33895 ("io_uring: preparation for rsrc tagging") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/0130c5c2693468173ec1afab714e0885d2c9c363.1628559783.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-10io_uring: drop ctx->uring_lock before flushing work itemJens Axboe1-2/+4
Ammar reports that he's seeing a lockdep splat on running test/rsrc_tags from the regression suite: ====================================================== WARNING: possible circular locking dependency detected 5.14.0-rc3-bluetea-test-00249-gc7d102232649 #5 Tainted: G OE ------------------------------------------------------ kworker/2:4/2684 is trying to acquire lock: ffff88814bb1c0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_rsrc_put_work+0x13d/0x1a0 but task is already holding lock: ffffc90001c6be70 ((work_completion)(&(&ctx->rsrc_put_work)->work)){+.+.}-{0:0}, at: process_one_work+0x1bc/0x530 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 ((work_completion)(&(&ctx->rsrc_put_work)->work)){+.+.}-{0:0}: __flush_work+0x31b/0x490 io_rsrc_ref_quiesce.part.0.constprop.0+0x35/0xb0 __do_sys_io_uring_register+0x45b/0x1060 do_syscall_64+0x35/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #0 (&ctx->uring_lock){+.+.}-{3:3}: __lock_acquire+0x119a/0x1e10 lock_acquire+0xc8/0x2f0 __mutex_lock+0x86/0x740 io_rsrc_put_work+0x13d/0x1a0 process_one_work+0x236/0x530 worker_thread+0x52/0x3b0 kthread+0x135/0x160 ret_from_fork+0x1f/0x30 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((work_completion)(&(&ctx->rsrc_put_work)->work)); lock(&ctx->uring_lock); lock((work_completion)(&(&ctx->rsrc_put_work)->work)); lock(&ctx->uring_lock); *** DEADLOCK *** 2 locks held by kworker/2:4/2684: #0: ffff88810004d938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1bc/0x530 #1: ffffc90001c6be70 ((work_completion)(&(&ctx->rsrc_put_work)->work)){+.+.}-{0:0}, at: process_one_work+0x1bc/0x530 stack backtrace: CPU: 2 PID: 2684 Comm: kworker/2:4 Tainted: G OE 5.14.0-rc3-bluetea-test-00249-gc7d102232649 #5 Hardware name: Acer Aspire ES1-421/OLVIA_BE, BIOS V1.05 07/02/2015 Workqueue: events io_rsrc_put_work Call Trace: dump_stack_lvl+0x6a/0x9a check_noncircular+0xfe/0x110 __lock_acquire+0x119a/0x1e10 lock_acquire+0xc8/0x2f0 ? io_rsrc_put_work+0x13d/0x1a0 __mutex_lock+0x86/0x740 ? io_rsrc_put_work+0x13d/0x1a0 ? io_rsrc_put_work+0x13d/0x1a0 ? io_rsrc_put_work+0x13d/0x1a0 ? process_one_work+0x1ce/0x530 io_rsrc_put_work+0x13d/0x1a0 process_one_work+0x236/0x530 worker_thread+0x52/0x3b0 ? process_one_work+0x530/0x530 kthread+0x135/0x160 ? set_kthread_struct+0x40/0x40 ret_from_fork+0x1f/0x30 which is due to holding the ctx->uring_lock when flushing existing pending work, while the pending work flushing may need to grab the uring lock if we're using IOPOLL. Fix this by dropping the uring_lock a bit earlier as part of the flush. Cc: stable@vger.kernel.org Link: https://github.com/axboe/liburing/issues/404 Tested-by: Ammar Faizi <ammarfaizi2@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-10io-wq: fix IO_WORKER_F_FIXED issue in create_io_worker()Hao Xu1-7/+11
There may be cases like: A B spin_lock(wqe->lock) nr_workers is 0 nr_workers++ spin_unlock(wqe->lock) spin_lock(wqe->lock) nr_wokers is 1 nr_workers++ spin_unlock(wqe->lock) create_io_worker() acct->worker is 1 create_io_worker() acct->worker is 1 There should be one worker marked IO_WORKER_F_FIXED, but no one is. Fix this by introduce a new agrument for create_io_worker() to indicate if it is the first worker. Fixes: 3d4e4face9c1 ("io-wq: fix no lock protection of acct->nr_worker") Signed-off-by: Hao Xu <haoxu@linux.alibaba.com> Link: https://lore.kernel.org/r/20210808135434.68667-3-haoxu@linux.alibaba.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-10io-wq: fix bug of creating io-wokers unconditionallyHao Xu1-2/+10
The former patch to add check between nr_workers and max_workers has a bug, which will cause unconditionally creating io-workers. That's because the result of the check doesn't affect the call of create_io_worker(), fix it by bringing in a boolean value for it. Fixes: 21698274da5b ("io-wq: fix lack of acct->nr_workers < acct->max_workers judgement") Signed-off-by: Hao Xu <haoxu@linux.alibaba.com> Link: https://lore.kernel.org/r/20210808135434.68667-2-haoxu@linux.alibaba.com [axboe: drop hunk that isn't strictly needed] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-10io_uring: rsrc ref lock needs to be IRQ safeJens Axboe1-14/+5
Nadav reports running into the below splat on re-enabling softirqs: WARNING: CPU: 2 PID: 1777 at kernel/softirq.c:364 __local_bh_enable_ip+0xaa/0xe0 Modules linked in: CPU: 2 PID: 1777 Comm: umem Not tainted 5.13.1+ #161 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/22/2020 RIP: 0010:__local_bh_enable_ip+0xaa/0xe0 Code: a9 00 ff ff 00 74 38 65 ff 0d a2 21 8c 7a e8 ed 1a 20 00 fb 66 0f 1f 44 00 00 5b 41 5c 5d c3 65 8b 05 e6 2d 8c 7a 85 c0 75 9a <0f> 0b eb 96 e8 2d 1f 20 00 eb a5 4c 89 e7 e8 73 4f 0c 00 eb ae 65 RSP: 0018:ffff88812e58fcc8 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000000201 RCX: dffffc0000000000 RDX: 0000000000000007 RSI: 0000000000000201 RDI: ffffffff8898c5ac RBP: ffff88812e58fcd8 R08: ffffffff8575dbbf R09: ffffed1028ef14f9 R10: ffff88814778a7c3 R11: ffffed1028ef14f8 R12: ffffffff85c9e9ae R13: ffff88814778a000 R14: ffff88814778a7b0 R15: ffff8881086db890 FS: 00007fbcfee17700(0000) GS:ffff8881e0300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c0402a5008 CR3: 000000011c1ac003 CR4: 00000000003706e0 Call Trace: _raw_spin_unlock_bh+0x31/0x40 io_rsrc_node_ref_zero+0x13e/0x190 io_dismantle_req+0x215/0x220 io_req_complete_post+0x1b8/0x720 __io_complete_rw.isra.0+0x16b/0x1f0 io_complete_rw+0x10/0x20 where it's clear we end up calling the percpu count release directly from the completion path, as it's in atomic mode and we drop the last ref. For file/block IO, this can be from IRQ context already, and the softirq locking for rsrc isn't enough. Just make the lock fully IRQ safe, and ensure we correctly safe state from the release path as we don't know the full context there. Reported-by: Nadav Amit <nadav.amit@gmail.com> Tested-by: Nadav Amit <nadav.amit@gmail.com> Link: https://lore.kernel.org/io-uring/C187C836-E78B-4A31-B24C-D16919ACA093@gmail.com/ Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09ucounts: add missing data type changesSven Schnelle2-12/+22
commit f9c82a4ea89c3 ("Increase size of ucounts to atomic_long_t") changed the data type of ucounts/ucounts_max to long, but missed to adjust a few other places. This is noticeable on big endian platforms from user space because the /proc/sys/user/max_*_names files all contain 0. v4 - Made the min and max constants long so the sysctl values are actually settable on little endian machines. -- EWB Fixes: f9c82a4ea89c ("Increase size of ucounts to atomic_long_t") Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Linux Kernel Functional Testing <lkft@linaro.org> Acked-by: Alexey Gladkov <legion@kernel.org> v1: https://lkml.kernel.org/r/20210721115800.910778-1-svens@linux.ibm.com v2: https://lkml.kernel.org/r/20210721125233.1041429-1-svens@linux.ibm.com v3: https://lkml.kernel.org/r/20210730062854.3601635-1-svens@linux.ibm.com Link: https://lkml.kernel.org/r/8735rijqlv.fsf_-_@disp2133 Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2021-08-09configfs: restore the kernel v5.13 text attribute write behaviorBart Van Assche1-12/+6
Instead of appending new text attribute data at the offset specified by the write() system call, only pass the newly written data to the .store() callback. Reported-by: Bodo Stroesser <bostroesser@gmail.com> Tested-by: Bodo Stroesser <bostroesser@gmail.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-08-09io_uring: Use WRITE_ONCE() when writing to sq_flagsNadav Amit1-4/+9
The compiler should be forbidden from any strange optimization for async writes to user visible data-structures. Without proper protection, the compiler can cause write-tearing or invent writes that would confuse the userspace. However, there are writes to sq_flags which are not protected by WRITE_ONCE(). Use WRITE_ONCE() for these writes. This is purely a theoretical issue. Presumably, any compiler is very unlikely to do such optimizations. Fixes: 75b28affdd6a ("io_uring: allocate the two rings together") Cc: Jens Axboe <axboe@kernel.dk> Cc: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Nadav Amit <namit@vmware.com> Link: https://lore.kernel.org/r/20210808001342.964634-3-namit@vmware.com Signed-off-by: Jens Axboe <axboe@kernel.dk>