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* kernfs: fix potential NULL dereference in __kernfs_removeYushan Zhou2022-07-011-2/+5
| | | | | | | | | | | | | | When lockdep is enabled, lockdep_assert_held_write would cause potential NULL pointer dereference. Fix the following smatch warnings: fs/kernfs/dir.c:1353 __kernfs_remove() warn: variable dereferenced before check 'kn' (see line 1346) Fixes: 393c3714081a ("kernfs: switch global kernfs_rwsem lock to per-fs lock") Signed-off-by: Yushan Zhou <katrinzhou@tencent.com> Link: https://lore.kernel.org/r/20220630082512.3482581-1-zys.zljxml@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kernfs: Separate kernfs_pr_cont_buf and rename_lock.Hao Luo2022-05-191-12/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously the protection of kernfs_pr_cont_buf was piggy backed by rename_lock, which means that pr_cont() needs to be protected under rename_lock. This can cause potential circular lock dependencies. If there is an OOM, we have the following call hierarchy: -> cpuset_print_current_mems_allowed() -> pr_cont_cgroup_name() -> pr_cont_kernfs_name() pr_cont_kernfs_name() will grab rename_lock and call printk. So we have the following lock dependencies: kernfs_rename_lock -> console_sem Sometimes, printk does a wakeup before releasing console_sem, which has the dependence chain: console_sem -> p->pi_lock -> rq->lock Now, imagine one wants to read cgroup_name under rq->lock, for example, printing cgroup_name in a tracepoint in the scheduler code. They will be holding rq->lock and take rename_lock: rq->lock -> kernfs_rename_lock Now they will deadlock. A prevention to this circular lock dependency is to separate the protection of pr_cont_buf from rename_lock. In principle, rename_lock is to protect the integrity of cgroup name when copying to buf. Once pr_cont_buf has got its content, rename_lock can be dropped. So it's safe to drop rename_lock after kernfs_name_locked (and kernfs_path_from_node_locked) and rely on a dedicated pr_cont_lock to protect pr_cont_buf. Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Hao Luo <haoluo@google.com> Link: https://lore.kernel.org/r/20220516190951.3144144-1-haoluo@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kernfs: fix NULL dereferencing in kernfs_removeMinchan Kim2022-04-271-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kernfs_remove supported NULL kernfs_node param to bail out but revent per-fs lock change introduced regression that dereferencing the param without NULL check so kernel goes crash. This patch checks the NULL kernfs_node in kernfs_remove and if so, just return. Quote from bug report by Jirka ``` The bug is triggered by running NAS Parallel benchmark suite on SuperMicro servers with 2x Xeon(R) Gold 6126 CPU. Here is the error log: [ 247.035564] BUG: kernel NULL pointer dereference, address: 0000000000000008 [ 247.036009] #PF: supervisor read access in kernel mode [ 247.036009] #PF: error_code(0x0000) - not-present page [ 247.036009] PGD 0 P4D 0 [ 247.036009] Oops: 0000 [#1] PREEMPT SMP PTI [ 247.058060] CPU: 1 PID: 6546 Comm: umount Not tainted 5.16.0393c3714081a53795bbff0e985d24146def6f57f+ #16 [ 247.058060] Hardware name: Supermicro Super Server/X11DDW-L, BIOS 2.0b 03/07/2018 [ 247.058060] RIP: 0010:kernfs_remove+0x8/0x50 [ 247.058060] Code: 4c 89 e0 5b 5d 41 5c 41 5d 41 5e c3 49 c7 c4 f4 ff ff ff eb b2 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 0f 1f 44 00 00 41 54 55 <48> 8b 47 08 48 89 fd 48 85 c0 48 0f 44 c7 4c 8b 60 50 49 83 c4 60 [ 247.058060] RSP: 0018:ffffbbfa48a27e48 EFLAGS: 00010246 [ 247.058060] RAX: 0000000000000001 RBX: ffffffff89e31f98 RCX: 0000000080200018 [ 247.058060] RDX: 0000000080200019 RSI: fffff6760786c900 RDI: 0000000000000000 [ 247.058060] RBP: ffffffff89e31f98 R08: ffff926b61b24d00 R09: 0000000080200018 [ 247.122048] R10: ffff926b61b24d00 R11: ffff926a8040c000 R12: ffff927bd09a2000 [ 247.122048] R13: ffffffff89e31fa0 R14: dead000000000122 R15: dead000000000100 [ 247.122048] FS: 00007f01be0a8c40(0000) GS:ffff926fa8e40000(0000) knlGS:0000000000000000 [ 247.122048] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 247.122048] CR2: 0000000000000008 CR3: 00000001145c6003 CR4: 00000000007706e0 [ 247.122048] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 247.122048] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 247.122048] PKRU: 55555554 [ 247.122048] Call Trace: [ 247.122048] <TASK> [ 247.122048] rdt_kill_sb+0x29d/0x350 [ 247.122048] deactivate_locked_super+0x36/0xa0 [ 247.122048] cleanup_mnt+0x131/0x190 [ 247.122048] task_work_run+0x5c/0x90 [ 247.122048] exit_to_user_mode_prepare+0x229/0x230 [ 247.122048] syscall_exit_to_user_mode+0x18/0x40 [ 247.122048] do_syscall_64+0x48/0x90 [ 247.122048] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 247.122048] RIP: 0033:0x7f01be2d735b ``` Link: https://bugzilla.kernel.org/show_bug.cgi?id=215696 Link: https://lore.kernel.org/lkml/CAE4VaGDZr_4wzRn2___eDYRtmdPaGGJdzu_LCSkJYuY9BEO3cw@mail.gmail.com/ Fixes: 393c3714081a (kernfs: switch global kernfs_rwsem lock to per-fs lock) Cc: stable@vger.kernel.org Reported-by: Jirka Hladky <jhladky@redhat.com> Tested-by: Jirka Hladky <jhladky@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Minchan Kim <minchan@kernel.org> Link: https://lore.kernel.org/r/20220427172152.3505364-1-minchan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kernfs: move struct kernfs_root out of the public view.Greg Kroah-Hartman2022-02-231-0/+9
| | | | | | | | | | | | There is no need to have struct kernfs_root be part of kernfs.h for the whole kernel to see and poke around it. Move it internal to kernfs code and provide a helper function, kernfs_root_to_node(), to handle the one field that kernfs users were directly accessing from the structure. Cc: Imran Khan <imran.f.khan@oracle.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20220222070713.3517679-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kernfs: prevent early freeing of root nodeMinchan Kim2021-12-031-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Marek reported the warning below. ========================= WARNING: held lock freed! 5.16.0-rc2+ #10984 Not tainted ------------------------- kworker/1:0/18 is freeing memory ffff00004034e200-ffff00004034e3ff, with a lock still held there! ffff00004034e348 (&root->kernfs_rwsem){++++}-{3:3}, at: __kernfs_remove+0x310/0x37c 3 locks held by kworker/1:0/18: #0: ffff000040107938 ((wq_completion)cgroup_destroy){+.+.}-{0:0}, at: process_one_work+0x1f0/0x6f0 #1: ffff80000b55bdc0 ((work_completion)(&(&css->destroy_rwork)->work)){+.+.}-{0:0}, at: process_one_work+0x1f0/0x6f0 #2: ffff00004034e348 (&root->kernfs_rwsem){++++}-{3:3}, at: __kernfs_remove+0x310/0x37c stack backtrace: CPU: 1 PID: 18 Comm: kworker/1:0 Not tainted 5.16.0-rc2+ #10984 Hardware name: Raspberry Pi 4 Model B (DT) Workqueue: cgroup_destroy css_free_rwork_fn Call trace: dump_backtrace+0x0/0x1ac show_stack+0x18/0x24 dump_stack_lvl+0x8c/0xb8 dump_stack+0x18/0x34 debug_check_no_locks_freed+0x124/0x140 kfree+0xf0/0x3a4 kernfs_put+0x1f8/0x224 __kernfs_remove+0x1b8/0x37c kernfs_destroy_root+0x38/0x50 css_free_rwork_fn+0x288/0x3d4 process_one_work+0x288/0x6f0 worker_thread+0x74/0x470 kthread+0x188/0x194 ret_from_fork+0x10/0x20 Since kernfs moves the kernfs_rwsem lock into root, it couldn't hold the lock when the root node is tearing down. Thus, get the refcount of root node. Fixes: 393c3714081a ("kernfs: switch global kernfs_rwsem lock to per-fs lock") Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Minchan Kim <minchan@kernel.org> Link: https://lore.kernel.org/r/20211201231648.1027165-1-minchan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kernfs: switch global kernfs_rwsem lock to per-fs lockMinchan Kim2021-11-241-45/+65
| | | | | | | | | | | | | | | | | | | | | | | The kernfs implementation has big lock granularity(kernfs_rwsem) so every kernfs-based(e.g., sysfs, cgroup) fs are able to compete the lock. It makes trouble for some cases to wait the global lock for a long time even though they are totally independent contexts each other. A general example is process A goes under direct reclaim with holding the lock when it accessed the file in sysfs and process B is waiting the lock with exclusive mode and then process C is waiting the lock until process B could finish the job after it gets the lock from process A. This patch switches the global kernfs_rwsem to per-fs lock, which put the rwsem into kernfs_root. Suggested-by: Tejun Heo <tj@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Minchan Kim <minchan@kernel.org> Link: https://lore.kernel.org/r/20211118230008.2679780-1-minchan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kernfs: don't create a negative dentry if inactive node existsIan Kent2021-10-041-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's been reported that doing stress test for module insertion and removal can result in an ENOENT from libkmod for a valid module. In kernfs_iop_lookup() a negative dentry is created if there's no kernfs node associated with the dentry or the node is inactive. But inactive kernfs nodes are meant to be invisible to the VFS and creating a negative dentry for these can have unexpected side effects when the node transitions to an active state. The point of creating negative dentries is to avoid the expensive alloc/free cycle that occurs if there are frequent lookups for kernfs attributes that don't exist. So kernfs nodes that are not yet active should not result in a negative dentry being created so when they transition to an active state VFS lookups can create an associated dentry is a natural way. It's also been reported that https://github.com/osandov/blktests.git test block/001 hangs during the test. It was suggested that recent changes to blktests might have caused it but applying this patch resolved the problem without change to blktests. Fixes: c7e7c04274b1 ("kernfs: use VFS negative dentry caching") Tested-by: Yi Zhang <yi.zhang@redhat.com> ACKed-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ian Kent <raven@themaw.net> Link: https://lore.kernel.org/r/163330943316.19450.15056895533949392922.stgit@mickey.themaw.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kernfs: also call kernfs_set_rev() for positive dentryHou Tao2021-09-281-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A KMSAN warning is reported by Alexander Potapenko: BUG: KMSAN: uninit-value in kernfs_dop_revalidate+0x61f/0x840 fs/kernfs/dir.c:1053 kernfs_dop_revalidate+0x61f/0x840 fs/kernfs/dir.c:1053 d_revalidate fs/namei.c:854 lookup_dcache fs/namei.c:1522 __lookup_hash+0x3a6/0x590 fs/namei.c:1543 filename_create+0x312/0x7c0 fs/namei.c:3657 do_mkdirat+0x103/0x930 fs/namei.c:3900 __do_sys_mkdir fs/namei.c:3931 __se_sys_mkdir fs/namei.c:3929 __x64_sys_mkdir+0xda/0x120 fs/namei.c:3929 do_syscall_x64 arch/x86/entry/common.c:51 It seems a positive dentry in kernfs becomes a negative dentry directly through d_delete() in vfs_rmdir(). dentry->d_time is uninitialized when accessing it in kernfs_dop_revalidate(), because it is only initialized when created as negative dentry in kernfs_iop_lookup(). The problem can be reproduced by the following command: cd /sys/fs/cgroup/pids && mkdir hi && stat hi && rmdir hi && stat hi A simple fixes seems to be initializing d->d_time for positive dentry in kernfs_iop_lookup() as well. The downside is the negative dentry will be revalidated again after it becomes negative in d_delete(), because the revison of its parent must have been increased due to its removal. Alternative solution is implement .d_iput for kernfs, and assign d_time for the newly-generated negative dentry in it. But we may need to take kernfs_rwsem to protect again the concurrent kernfs_link_sibling() on the parent directory, it is a little over-killing. Now the simple fix is chosen. Link: https://marc.info/?l=linux-fsdevel&m=163249838610499 Fixes: c7e7c04274b1 ("kernfs: use VFS negative dentry caching") Reported-by: Alexander Potapenko <glider@google.com> Signed-off-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20210928140750.1274441-1-houtao1@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kernfs: dont call d_splice_alias() under kernfs node lockIan Kent2021-07-271-4/+2
| | | | | | | | | | | The call to d_splice_alias() in kernfs_iop_lookup() doesn't depend on any kernfs node so there's no reason to hold the kernfs node lock when calling it. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Ian Kent <raven@themaw.net> Link: https://lore.kernel.org/r/162642772000.63632.10672683419693513226.stgit@web.messagingengine.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kernfs: switch kernfs to use an rwsemIan Kent2021-07-271-50/+50
| | | | | | | | | | | | | The kernfs global lock restricts the ability to perform kernfs node lookup operations in parallel during path walks. Change the kernfs mutex to an rwsem so that, when opportunity arises, node searches can be done in parallel with path walk lookups. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Ian Kent <raven@themaw.net> Link: https://lore.kernel.org/r/162642770946.63632.2218304587223241374.stgit@web.messagingengine.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kernfs: use VFS negative dentry cachingIan Kent2021-07-271-20/+35
| | | | | | | | | | | | | | | | | | If there are many lookups for non-existent paths these negative lookups can lead to a lot of overhead during path walks. The VFS allows dentries to be created as negative and hashed, and caches them so they can be used to reduce the fairly high overhead alloc/free cycle that occurs during these lookups. Use the kernfs node parent revision to identify if a change has been made to the containing directory so that the negative dentry can be discarded and the lookup redone. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Ian Kent <raven@themaw.net> Link: https://lore.kernel.org/r/162642770420.63632.15791924970508867106.stgit@web.messagingengine.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kernfs: add a revision to identify directory node changesIan Kent2021-07-271-0/+2
| | | | | | | | | | | | | | | | | | | | | | Add a revision counter to kernfs directory nodes so it can be used to detect if a directory node has changed during negative dentry revalidation. There's an assumption that sizeof(unsigned long) <= sizeof(pointer) on all architectures and as far as I know that assumption holds. So adding a revision counter to the struct kernfs_elem_dir variant of the kernfs_node type union won't increase the size of the kernfs_node struct. This is because struct kernfs_elem_dir is at least sizeof(pointer) smaller than the largest union variant. It's tempting to make the revision counter a u64 but that would increase the size of kernfs_node on archs where sizeof(pointer) is smaller than the revision counter. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Ian Kent <raven@themaw.net> Link: https://lore.kernel.org/r/162642769895.63632.8356662784964509867.stgit@web.messagingengine.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kernfs: move revalidate to be near lookupIan Kent2021-06-151-43/+43
| | | | | | | | | | | | | | | | | While the dentry operation kernfs_dop_revalidate() is grouped with dentry type functions it also has a strong affinity to the inode operation ->lookup(). It makes sense to locate this function near to kernfs_iop_lookup() because we will be adding VFS negative dentry caching to reduce path lookup overhead for non-existent paths. There's no functional change from this patch. Signed-off-by: Ian Kent <raven@themaw.net> Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Link: https://lore.kernel.org/r/162375275365.232295.8995526416263659926.stgit@web.messagingengine.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* fs: make helpers idmap mount awareChristian Brauner2021-01-241-2/+4
| | | | | | | | | | | | | | | | | | | | | Extend some inode methods with an additional user namespace argument. A filesystem that is aware of idmapped mounts will receive the user namespace the mount has been marked with. This can be used for additional permission checking and also to enable filesystems to translate between uids and gids if they need to. We have implemented all relevant helpers in earlier patches. As requested we simply extend the exisiting inode method instead of introducing new ones. This is a little more code churn but it's mostly mechanical and doesnt't leave us with additional inode methods. Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com Cc: Christoph Hellwig <hch@lst.de> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
* fs/kernfs: remove the double check of dentry->inodeHui Su2020-12-091-2/+1
| | | | | | | | | | | | | In both kernfs_node_from_dentry() and in kernfs_dentry_node(), we will check the dentry->inode is NULL or not, which is superfluous. So remove the check in kernfs_node_from_dentry(). Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Hui Su <sh_def@163.com> Link: https://lore.kernel.org/r/20201113132143.GA119541@rlk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kernfs: bring names in comments in line with codeWillem de Bruijn2020-11-091-1/+1
| | | | | | | | | | Fix two stragglers in the comments of the below rename operation. Fixes: adc5e8b58f48 ("kernfs: drop s_ prefix from kernfs_node members") Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Willem de Bruijn <willemb@google.com> Link: https://lore.kernel.org/r/20201015185726.1386868-1-willemdebruijn.kernel@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* fs/kernfs/dir.c: Clean code by removing always true conditionMateusz Nosek2020-01-141-1/+1
| | | | | | | | | | | | Previously there was an additional check if variable pos is not null. However, this check happens after entering while loop and only then, which can happen only if pos is not null. Therefore the additional check is redundant and can be removed. Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20191230191628.21099-1-mateusznosek0@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge branch 'locking-core-for-linus' of ↵Linus Torvalds2019-11-261-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "The main changes in this cycle were: - A comprehensive rewrite of the robust/PI futex code's exit handling to fix various exit races. (Thomas Gleixner et al) - Rework the generic REFCOUNT_FULL implementation using atomic_fetch_* operations so that the performance impact of the cmpxchg() loops is mitigated for common refcount operations. With these performance improvements the generic implementation of refcount_t should be good enough for everybody - and this got confirmed by performance testing, so remove ARCH_HAS_REFCOUNT and REFCOUNT_FULL entirely, leaving the generic implementation enabled unconditionally. (Will Deacon) - Other misc changes, fixes, cleanups" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits) lkdtm: Remove references to CONFIG_REFCOUNT_FULL locking/refcount: Remove unused 'refcount_error_report()' function locking/refcount: Consolidate implementations of refcount_t locking/refcount: Consolidate REFCOUNT_{MAX,SATURATED} definitions locking/refcount: Move saturation warnings out of line locking/refcount: Improve performance of generic REFCOUNT_FULL code locking/refcount: Move the bulk of the REFCOUNT_FULL implementation into the <linux/refcount.h> header locking/refcount: Remove unused refcount_*_checked() variants locking/refcount: Ensure integer operands are treated as signed locking/refcount: Define constants for saturation and max refcount values futex: Prevent exit livelock futex: Provide distinct return value when owner is exiting futex: Add mutex around futex exit futex: Provide state handling for exec() as well futex: Sanitize exit state handling futex: Mark the begin of futex exit explicitly futex: Set task::futex_state to DEAD right after handling futex exit futex: Split futex_mm_release() for exit/exec exit/exec: Seperate mm_release() futex: Replace PF_EXITPIDONE with a state ...
| * locking/lockdep: Remove unused @nested argument from lock_release()Qian Cai2019-10-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since the following commit: b4adfe8e05f1 ("locking/lockdep: Remove unused argument in __lock_release") @nested is no longer used in lock_release(), so remove it from all lock_release() calls and friends. Signed-off-by: Qian Cai <cai@lca.pw> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: airlied@linux.ie Cc: akpm@linux-foundation.org Cc: alexander.levin@microsoft.com Cc: daniel@iogearbox.net Cc: davem@davemloft.net Cc: dri-devel@lists.freedesktop.org Cc: duyuyang@gmail.com Cc: gregkh@linuxfoundation.org Cc: hannes@cmpxchg.org Cc: intel-gfx@lists.freedesktop.org Cc: jack@suse.com Cc: jlbec@evilplan.or Cc: joonas.lahtinen@linux.intel.com Cc: joseph.qi@linux.alibaba.com Cc: jslaby@suse.com Cc: juri.lelli@redhat.com Cc: maarten.lankhorst@linux.intel.com Cc: mark@fasheh.com Cc: mhocko@kernel.org Cc: mripard@kernel.org Cc: ocfs2-devel@oss.oracle.com Cc: rodrigo.vivi@intel.com Cc: sean@poorly.run Cc: st@kernel.org Cc: tj@kernel.org Cc: tytso@mit.edu Cc: vdavydov.dev@gmail.com Cc: vincent.guittot@linaro.org Cc: viro@zeniv.linux.org.uk Link: https://lkml.kernel.org/r/1568909380-32199-1-git-send-email-cai@lca.pw Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | kernfs: use 64bit inos if ino_t is 64bitTejun Heo2019-11-121-13/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Each kernfs_node is identified with a 64bit ID. The low 32bit is exposed as ino and the high gen. While this already allows using inos as keys by looking up with wildcard generation number of 0, it's adding unnecessary complications for 64bit ino archs which can directly use kernfs_node IDs as inos to uniquely identify each cgroup instance. This patch exposes IDs directly as inos on 64bit ino archs. The conversion is mostly straight-forward. * 32bit ino archs behave the same as before. 64bit ino archs now use the whole 64bit ID as ino and the generation number is fixed at 1. * 64bit inos still use the same idr allocator which gurantees that the lower 32bits identify the current live instance uniquely and the high 32bits are incremented whenever the low bits wrap. As the upper 32bits are no longer used as gen and we don't wanna start ino allocation with 33rd bit set, the initial value for highbits allocation is changed to 0 on 64bit ino archs. * blktrace exposes two 32bit numbers - (INO,GEN) pair - to identify the issuing cgroup. Userland builds FILEID_INO32_GEN fids from these numbers to look up the cgroups. To remain compatible with the behavior, always output (LOW32,HIGH32) which will be constructed back to the original 64bit ID by __kernfs_fh_to_dentry(). Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Namhyung Kim <namhyung@kernel.org>
* | kernfs: combine ino/id lookup functions into kernfs_find_and_get_node_by_id()Tejun Heo2019-11-121-4/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kernfs_find_and_get_node_by_ino() looks the kernfs_node matching the specified ino. On top of that, kernfs_get_node_by_id() and kernfs_fh_get_inode() implement full ID matching by testing the rest of ID. On surface, confusingly, the two are slightly different in that the latter uses 0 gen as wildcard while the former doesn't - does it mean that the latter can't uniquely identify inodes w/ 0 gen? In practice, this is a distinction without a difference because generation number starts at 1. There are no actual IDs with 0 gen, so it can always safely used as wildcard. Let's simplify the code by renaming kernfs_find_and_get_node_by_ino() to kernfs_find_and_get_node_by_id(), moving all lookup logics into it, and removing now unnecessary kernfs_get_node_by_id(). Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | kernfs: convert kernfs_node->id from union kernfs_node_id to u64Tejun Heo2019-11-121-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kernfs_node->id is currently a union kernfs_node_id which represents either a 32bit (ino, gen) pair or u64 value. I can't see much value in the usage of the union - all that's needed is a 64bit ID which the current code is already limited to. Using a union makes the code unnecessarily complicated and prevents using 64bit ino without adding practical benefits. This patch drops union kernfs_node_id and makes kernfs_node->id a u64. ino is stored in the lower 32bits and gen upper. Accessors - kernfs[_id]_ino() and kernfs[_id]_gen() - are added to retrieve the ino and gen. This simplifies ID handling less cumbersome and will allow using 64bit inos on supported archs. This patch doesn't make any functional changes. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Alexei Starovoitov <ast@kernel.org>
* | kernfs: kernfs_find_and_get_node_by_ino() should only look up activated nodesTejun Heo2019-11-121-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kernfs node can be created in two separate steps - allocation and activation. This is used to make kernfs nodes visible only after the internal states attached to the node are fully initialized. kernfs_find_and_get_node_by_id() currently allows lookups of nodes which aren't activated yet and thus can expose nodes are which are still being prepped by kernfs users. Fix it by disallowing lookups of nodes which aren't activated yet. kernfs_find_and_get_node_by_ino() Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Namhyung Kim <namhyung@kernel.org>
* | kernfs: use dumber locking for kernfs_find_and_get_node_by_ino()Tejun Heo2019-11-121-36/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kernfs_find_and_get_node_by_ino() uses RCU protection. It's currently a bit buggy because it can look up a node which hasn't been activated yet and thus may end up exposing a node that the kernfs user is still prepping. While it can be fixed by pushing it further in the current direction, it's already complicated and isn't clear whether the complexity is justified. The main use of kernfs_find_and_get_node_by_ino() is for exportfs operations. They aren't super hot and all the follow-up operations (e.g. mapping to path) use normal locking anyway. Let's switch to a dumber locking scheme and protect the lookup with kernfs_idr_lock. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Namhyung Kim <namhyung@kernel.org>
* | kernfs: fix ino wrap-around detectionTejun Heo2019-11-121-3/+2
|/ | | | | | | | | | | | | | | | When the 32bit ino wraps around, kernfs increments the generation number to distinguish reused ino instances. The wrap-around detection tests whether the allocated ino is lower than what the cursor but the cursor is pointing to the next ino to allocate so the condition never triggers. Fix it by remembering the last ino and comparing against that. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Fixes: 4a3ef68acacf ("kernfs: implement i_generation") Cc: Namhyung Kim <namhyung@kernel.org> Cc: stable@vger.kernel.org # v4.14+
* fs: kernfs: Fix possible null-pointer dereferences in ↵Jia-Ju Bai2019-07-251-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | kernfs_path_from_node_locked() In kernfs_path_from_node_locked(), there is an if statement on line 147 to check whether buf is NULL: if (buf) When buf is NULL, it is used on line 151: len += strlcpy(buf + len, parent_str, ...) and line 158: len += strlcpy(buf + len, "/", ...) and line 160: len += strlcpy(buf + len, kn->name, ...) Thus, possible null-pointer dereferences may occur. To fix these possible bugs, buf is checked before being used. If it is NULL, -EINVAL is returned. These bugs are found by a static analysis tool STCheck written by us. Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> Link: https://lore.kernel.org/r/20190724022242.27505-1-baijiaju1990@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kernfs: fix potential null pointer dereferencePeng Wang2019-07-251-2/+1
| | | | | | | | | Get root safely after kn is ensureed to be not null. Signed-off-by: Peng Wang <rocking@whu.edu.cn> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20190708151611.13242-1-rocking@whu.edu.cn Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428Thomas Gleixner2019-06-051-2/+1
| | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): this file is released under the gplv2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 68 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Armijn Hemel <armijn@tjaldur.nl> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531190114.292346262@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'selinux-pr-20190507' of ↵Linus Torvalds2019-05-071-11/+13
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux Pull selinux updates from Paul Moore: "We've got a few SELinux patches for the v5.2 merge window, the highlights are below: - Add LSM hooks, and the SELinux implementation, for proper labeling of kernfs. While we are only including the SELinux implementation here, the rest of the LSM folks have given the hooks a thumbs-up. - Update the SELinux mdp (Make Dummy Policy) script to actually work on a modern system. - Disallow userspace to change the LSM credentials via /proc/self/attr when the task's credentials are already overridden. The change was made in procfs because all the LSM folks agreed this was the Right Thing To Do and duplicating it across each LSM was going to be annoying" * tag 'selinux-pr-20190507' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: proc: prevent changes to overridden credentials selinux: Check address length before reading address family kernfs: fix xattr name handling in LSM helpers MAINTAINERS: update SELinux file patterns selinux: avoid uninitialized variable warning selinux: remove useless assignments LSM: lsm_hooks.h - fix missing colon in docstring selinux: Make selinux_kernfs_init_security static kernfs: initialize security of newly created nodes selinux: implement the kernfs_init_security hook LSM: add new hook for kernfs node initialization kernfs: use simple_xattrs for security attributes selinux: try security xattr after genfs for kernfs filesystems kernfs: do not alloc iattrs in kernfs_xattr_get kernfs: clean up struct kernfs_iattrs scripts/selinux: fix build selinux: use kernel linux/socket.h for genheaders and mdp scripts/selinux: modernize mdp
| * kernfs: initialize security of newly created nodesOndrej Mosnacek2019-03-201-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use the new security_kernfs_init_security() hook to allow LSMs to possibly assign a non-default security context to a newly created kernfs node based on the attributes of the new node and also its parent node. This fixes an issue with cgroupfs under SELinux, where newly created cgroup subdirectories/files would not inherit its parent's context if it had been set explicitly to a non-default value (other than the genfs context specified by the policy). This can be reproduced as follows (on Fedora/RHEL): # mkdir /sys/fs/cgroup/unified/test # # Need permissive to change the label under Fedora policy: # setenforce 0 # chcon -t container_file_t /sys/fs/cgroup/unified/test # ls -lZ /sys/fs/cgroup/unified total 0 -r--r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 cgroup.controllers -rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 cgroup.max.depth -rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 cgroup.max.descendants -rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 cgroup.procs -r--r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 cgroup.stat -rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 cgroup.subtree_control -rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 cgroup.threads drwxr-xr-x. 2 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 init.scope drwxr-xr-x. 26 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:21 system.slice drwxr-xr-x. 3 root root system_u:object_r:container_file_t:s0 0 Jan 29 03:15 test drwxr-xr-x. 3 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 user.slice # mkdir /sys/fs/cgroup/unified/test/subdir Actual result: # ls -ldZ /sys/fs/cgroup/unified/test/subdir drwxr-xr-x. 2 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:15 /sys/fs/cgroup/unified/test/subdir Expected result: # ls -ldZ /sys/fs/cgroup/unified/test/subdir drwxr-xr-x. 2 root root unconfined_u:object_r:container_file_t:s0 0 Jan 29 03:15 /sys/fs/cgroup/unified/test/subdir Link: https://github.com/SELinuxProject/selinux-kernel/issues/39 Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
| * kernfs: use simple_xattrs for security attributesOndrej Mosnacek2019-03-201-3/+0
| | | | | | | | | | | | | | | | | | | | | | Replace the special handling of security xattrs with simple_xattrs, as is already done for the trusted xattrs. This simplifies the code and allows LSMs to use more than just a single xattr to do their business. Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> [PM: manual merge fixes] Signed-off-by: Paul Moore <paul@paul-moore.com>
| * kernfs: clean up struct kernfs_iattrsOndrej Mosnacek2019-03-201-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | Right now, kernfs_iattrs embeds the whole struct iattr, even though it doesn't really use half of its fields... This both leads to wasting space and makes the code look awkward. Let's just list the few fields we need directly in struct kernfs_iattrs. Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> [PM: merged a number of chunks manually due to fuzz] Signed-off-by: Paul Moore <paul@paul-moore.com>
* | kernfs: fix barrier usage in __kernfs_new_node()Andrea Parri2019-04-251-3/+2
|/ | | | | | | | | | | smp_mb__before_atomic() can not be applied to atomic_set(). Remove the barrier and rely on RELEASE synchronization. Fixes: ba16b2846a8c6 ("kernfs: add an API to get kernfs node from inode number") Cc: stable@vger.kernel.org Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kernfs: Allocating memory for kernfs_iattrs with kmem_cache.Ayush Mittal2019-02-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Creating a new cache for kernfs_iattrs. Currently, memory is allocated with kzalloc() which always gives aligned memory. On ARM, this is 64 byte aligned. To avoid the wastage of memory in aligning the size requested, a new cache for kernfs_iattrs is created. Size of struct kernfs_iattrs is 80 Bytes. On ARM, it will come in kmalloc-128 slab. and it will come in kmalloc-192 slab if debug info is enabled. Extra bytes taken 48 bytes. Total number of objects created : 4096 Total saving = 48*4096 = 192 KB After creating new slab(When debug info is enabled) : sh-3.2# cat /proc/slabinfo ... kernfs_iattrs_cache 4069 4096 128 32 1 : tunables 0 0 0 : slabdata 128 128 0 ... All testing has been done on ARM target. Signed-off-by: Ayush Mittal <ayush.m@samsung.com> Signed-off-by: Vaneet Narang <v.narang@samsung.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kernfs: allow creating kernfs objects with arbitrary uid/gidDmitry Torokhov2018-07-201-3/+26
| | | | | | | | | | | | | | | | This change allows creating kernfs files and directories with arbitrary uid/gid instead of always using GLOBAL_ROOT_UID/GID by extending kernfs_create_dir_ns() and kernfs_create_file_ns() with uid/gid arguments. The "simple" kernfs_create_file() and kernfs_create_dir() are left alone and always create objects belonging to the global root. When creating symlinks ownership (uid/gid) is taken from the target kernfs object. Co-Developed-by: Tyler Hicks <tyhicks@canonical.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* vfs: change inode times to use struct timespec64Deepa Dinamani2018-06-051-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | struct timespec is not y2038 safe. Transition vfs to use y2038 safe struct timespec64 instead. The change was made with the help of the following cocinelle script. This catches about 80% of the changes. All the header file and logic changes are included in the first 5 rules. The rest are trivial substitutions. I avoid changing any of the function signatures or any other filesystem specific data structures to keep the patch simple for review. The script can be a little shorter by combining different cases. But, this version was sufficient for my usecase. virtual patch @ depends on patch @ identifier now; @@ - struct timespec + struct timespec64 current_time ( ... ) { - struct timespec now = current_kernel_time(); + struct timespec64 now = current_kernel_time64(); ... - return timespec_trunc( + return timespec64_trunc( ... ); } @ depends on patch @ identifier xtime; @@ struct \( iattr \| inode \| kstat \) { ... - struct timespec xtime; + struct timespec64 xtime; ... } @ depends on patch @ identifier t; @@ struct inode_operations { ... int (*update_time) (..., - struct timespec t, + struct timespec64 t, ...); ... } @ depends on patch @ identifier t; identifier fn_update_time =~ "update_time$"; @@ fn_update_time (..., - struct timespec *t, + struct timespec64 *t, ...) { ... } @ depends on patch @ identifier t; @@ lease_get_mtime( ... , - struct timespec *t + struct timespec64 *t ) { ... } @te depends on patch forall@ identifier ts; local idexpression struct inode *inode_node; identifier i_xtime =~ "^i_[acm]time$"; identifier ia_xtime =~ "^ia_[acm]time$"; identifier fn_update_time =~ "update_time$"; identifier fn; expression e, E3; local idexpression struct inode *node1; local idexpression struct inode *node2; local idexpression struct iattr *attr1; local idexpression struct iattr *attr2; local idexpression struct iattr attr; identifier i_xtime1 =~ "^i_[acm]time$"; identifier i_xtime2 =~ "^i_[acm]time$"; identifier ia_xtime1 =~ "^ia_[acm]time$"; identifier ia_xtime2 =~ "^ia_[acm]time$"; @@ ( ( - struct timespec ts; + struct timespec64 ts; | - struct timespec ts = current_time(inode_node); + struct timespec64 ts = current_time(inode_node); ) <+... when != ts ( - timespec_equal(&inode_node->i_xtime, &ts) + timespec64_equal(&inode_node->i_xtime, &ts) | - timespec_equal(&ts, &inode_node->i_xtime) + timespec64_equal(&ts, &inode_node->i_xtime) | - timespec_compare(&inode_node->i_xtime, &ts) + timespec64_compare(&inode_node->i_xtime, &ts) | - timespec_compare(&ts, &inode_node->i_xtime) + timespec64_compare(&ts, &inode_node->i_xtime) | ts = current_time(e) | fn_update_time(..., &ts,...) | inode_node->i_xtime = ts | node1->i_xtime = ts | ts = inode_node->i_xtime | <+... attr1->ia_xtime ...+> = ts | ts = attr1->ia_xtime | ts.tv_sec | ts.tv_nsec | btrfs_set_stack_timespec_sec(..., ts.tv_sec) | btrfs_set_stack_timespec_nsec(..., ts.tv_nsec) | - ts = timespec64_to_timespec( + ts = ... -) | - ts = ktime_to_timespec( + ts = ktime_to_timespec64( ...) | - ts = E3 + ts = timespec_to_timespec64(E3) | - ktime_get_real_ts(&ts) + ktime_get_real_ts64(&ts) | fn(..., - ts + timespec64_to_timespec(ts) ,...) ) ...+> ( <... when != ts - return ts; + return timespec64_to_timespec(ts); ...> ) | - timespec_equal(&node1->i_xtime1, &node2->i_xtime2) + timespec64_equal(&node1->i_xtime2, &node2->i_xtime2) | - timespec_equal(&node1->i_xtime1, &attr2->ia_xtime2) + timespec64_equal(&node1->i_xtime2, &attr2->ia_xtime2) | - timespec_compare(&node1->i_xtime1, &node2->i_xtime2) + timespec64_compare(&node1->i_xtime1, &node2->i_xtime2) | node1->i_xtime1 = - timespec_trunc(attr1->ia_xtime1, + timespec64_trunc(attr1->ia_xtime1, ...) | - attr1->ia_xtime1 = timespec_trunc(attr2->ia_xtime2, + attr1->ia_xtime1 = timespec64_trunc(attr2->ia_xtime2, ...) | - ktime_get_real_ts(&attr1->ia_xtime1) + ktime_get_real_ts64(&attr1->ia_xtime1) | - ktime_get_real_ts(&attr.ia_xtime1) + ktime_get_real_ts64(&attr.ia_xtime1) ) @ depends on patch @ struct inode *node; struct iattr *attr; identifier fn; identifier i_xtime =~ "^i_[acm]time$"; identifier ia_xtime =~ "^ia_[acm]time$"; expression e; @@ ( - fn(node->i_xtime); + fn(timespec64_to_timespec(node->i_xtime)); | fn(..., - node->i_xtime); + timespec64_to_timespec(node->i_xtime)); | - e = fn(attr->ia_xtime); + e = fn(timespec64_to_timespec(attr->ia_xtime)); ) @ depends on patch forall @ struct inode *node; struct iattr *attr; identifier i_xtime =~ "^i_[acm]time$"; identifier ia_xtime =~ "^ia_[acm]time$"; identifier fn; @@ { + struct timespec ts; <+... ( + ts = timespec64_to_timespec(node->i_xtime); fn (..., - &node->i_xtime, + &ts, ...); | + ts = timespec64_to_timespec(attr->ia_xtime); fn (..., - &attr->ia_xtime, + &ts, ...); ) ...+> } @ depends on patch forall @ struct inode *node; struct iattr *attr; struct kstat *stat; identifier ia_xtime =~ "^ia_[acm]time$"; identifier i_xtime =~ "^i_[acm]time$"; identifier xtime =~ "^[acm]time$"; identifier fn, ret; @@ { + struct timespec ts; <+... ( + ts = timespec64_to_timespec(node->i_xtime); ret = fn (..., - &node->i_xtime, + &ts, ...); | + ts = timespec64_to_timespec(node->i_xtime); ret = fn (..., - &node->i_xtime); + &ts); | + ts = timespec64_to_timespec(attr->ia_xtime); ret = fn (..., - &attr->ia_xtime, + &ts, ...); | + ts = timespec64_to_timespec(attr->ia_xtime); ret = fn (..., - &attr->ia_xtime); + &ts); | + ts = timespec64_to_timespec(stat->xtime); ret = fn (..., - &stat->xtime); + &ts); ) ...+> } @ depends on patch @ struct inode *node; struct inode *node2; identifier i_xtime1 =~ "^i_[acm]time$"; identifier i_xtime2 =~ "^i_[acm]time$"; identifier i_xtime3 =~ "^i_[acm]time$"; struct iattr *attrp; struct iattr *attrp2; struct iattr attr ; identifier ia_xtime1 =~ "^ia_[acm]time$"; identifier ia_xtime2 =~ "^ia_[acm]time$"; struct kstat *stat; struct kstat stat1; struct timespec64 ts; identifier xtime =~ "^[acmb]time$"; expression e; @@ ( ( node->i_xtime2 \| attrp->ia_xtime2 \| attr.ia_xtime2 \) = node->i_xtime1 ; | node->i_xtime2 = \( node2->i_xtime1 \| timespec64_trunc(...) \); | node->i_xtime2 = node->i_xtime1 = node->i_xtime3 = \(ts \| current_time(...) \); | node->i_xtime1 = node->i_xtime3 = \(ts \| current_time(...) \); | stat->xtime = node2->i_xtime1; | stat1.xtime = node2->i_xtime1; | ( node->i_xtime2 \| attrp->ia_xtime2 \) = attrp->ia_xtime1 ; | ( attrp->ia_xtime1 \| attr.ia_xtime1 \) = attrp2->ia_xtime2; | - e = node->i_xtime1; + e = timespec64_to_timespec( node->i_xtime1 ); | - e = attrp->ia_xtime1; + e = timespec64_to_timespec( attrp->ia_xtime1 ); | node->i_xtime1 = current_time(...); | node->i_xtime2 = node->i_xtime1 = node->i_xtime3 = - e; + timespec_to_timespec64(e); | node->i_xtime1 = node->i_xtime3 = - e; + timespec_to_timespec64(e); | - node->i_xtime1 = e; + node->i_xtime1 = timespec_to_timespec64(e); ) Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Cc: <anton@tuxera.com> Cc: <balbi@kernel.org> Cc: <bfields@fieldses.org> Cc: <darrick.wong@oracle.com> Cc: <dhowells@redhat.com> Cc: <dsterba@suse.com> Cc: <dwmw2@infradead.org> Cc: <hch@lst.de> Cc: <hirofumi@mail.parknet.co.jp> Cc: <hubcap@omnibond.com> Cc: <jack@suse.com> Cc: <jaegeuk@kernel.org> Cc: <jaharkes@cs.cmu.edu> Cc: <jslaby@suse.com> Cc: <keescook@chromium.org> Cc: <mark@fasheh.com> Cc: <miklos@szeredi.hu> Cc: <nico@linaro.org> Cc: <reiserfs-devel@vger.kernel.org> Cc: <richard@nod.at> Cc: <sage@redhat.com> Cc: <sfrench@samba.org> Cc: <swhiteho@redhat.com> Cc: <tj@kernel.org> Cc: <trond.myklebust@primarydata.com> Cc: <tytso@mit.edu> Cc: <viro@zeniv.linux.org.uk>
* kernfs: introduce kernfs_node_idShaohua Li2017-07-291-5/+5
| | | | | | | | | | | inode number and generation can identify a kernfs node. We are going to export the identification by exportfs operations, so put ino and generation into a separate structure. It's convenient when later patches use the identification. Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* kernfs: don't set dentry->d_fsdataShaohua Li2017-07-291-16/+9
| | | | | | | | | | | | | | When working on adding exportfs operations in kernfs, I found it's hard to initialize dentry->d_fsdata in the exportfs operations. Looks there is no way to do it without race condition. Look at the kernfs code closely, there is no point to set dentry->d_fsdata. inode->i_private already points to kernfs_node, and we can get inode from a dentry. So this patch just delete the d_fsdata usage. Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* kernfs: add an API to get kernfs node from inode numberShaohua Li2017-07-291-0/+57
| | | | | | | | | | | | | | | Add an API to get kernfs node from inode number. We will need this to implement exportfs operations. This API will be used in blktrace too later, so it should be as fast as possible. To make the API lock free, kernfs node is freed in RCU context. And we depend on kernfs_node count/ino number to filter out stale kernfs nodes. Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* kernfs: implement i_generationShaohua Li2017-07-291-1/+9
| | | | | | | | | | | | | | | | | | | | Set i_generation for kernfs inode. This is required to implement exportfs operations. The generation is 32-bit, so it's possible the generation wraps up and we find stale files. To reduce the posssibility, we don't reuse inode numer immediately. When the inode number allocation wraps, we increase generation number. In this way generation/inode number consist of a 64-bit number which is unlikely duplicated. This does make the idr tree more sparse and waste some memory. Since idr manages 32-bit keys, idr uses a 6-level radix tree, each level covers 6 bits of the key. In a 100k inode kernfs, the worst case will have around 300k radix tree node. Each node is 576bytes, so the tree will use about ~150M memory. Sounds not too bad, if this really is a problem, we should find better data structure. Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* kernfs: use idr instead of ida to manage inode numberShaohua Li2017-07-291-5/+12
| | | | | | | | | | | kernfs uses ida to manage inode number. The problem is we can't get kernfs_node from inode number with ida. Switching to use idr, next patch will add an API to get kernfs_node from inode number. Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* Merge branch 'for-4.11' of ↵Linus Torvalds2017-02-271-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "Several noteworthy changes. - Parav's rdma controller is finally merged. It is very straight forward and can limit the abosolute numbers of common rdma constructs used by different cgroups. - kernel/cgroup.c got too chubby and disorganized. Created kernel/cgroup/ subdirectory and moved all cgroup related files under kernel/ there and reorganized the core code. This hurts for backporting patches but was long overdue. - cgroup v2 process listing reimplemented so that it no longer depends on allocating a buffer large enough to cache the entire result to sort and uniq the output. v2 has always mangled the sort order to ensure that users don't depend on the sorted output, so this shouldn't surprise anybody. This makes the pid listing functions use the same iterators that are used internally, which have to have the same iterating capabilities anyway. - perf cgroup filtering now works automatically on cgroup v2. This patch was posted a long time ago but somehow fell through the cracks. - misc fixes asnd documentation updates" * 'for-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (27 commits) kernfs: fix locking around kernfs_ops->release() callback cgroup: drop the matching uid requirement on migration for cgroup v2 cgroup, perf_event: make perf_event controller work on cgroup2 hierarchy cgroup: misc cleanups cgroup: call subsys->*attach() only for subsystems which are actually affected by migration cgroup: track migration context in cgroup_mgctx cgroup: cosmetic update to cgroup_taskset_add() rdmacg: Fixed uninitialized current resource usage cgroup: Add missing cgroup-v2 PID controller documentation. rdmacg: Added documentation for rdmacg IB/core: added support to use rdma cgroup controller rdmacg: Added rdma cgroup controller cgroup: fix a comment typo cgroup: fix RCU related sparse warnings cgroup: move namespace code to kernel/cgroup/namespace.c cgroup: rename functions for consistency cgroup: move v1 mount functions to kernel/cgroup/cgroup-v1.c cgroup: separate out cgroup1_kf_syscall_ops cgroup: refactor mount path and clearly distinguish v1 and v2 paths cgroup: move cgroup v1 specific code to kernel/cgroup/cgroup-v1.c ...
| * kernfs: add kernfs_ops->open/release() callbacksTejun Heo2016-12-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | Add ->open/release() methods to kernfs_ops. ->open() is called when the file is opened and ->release() when the file is either released or severed. These callbacks can be used, for example, to manage persistent caching objects over multiple seq_file iterations. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Acked-by: Zefan Li <lizefan@huawei.com>
* | kernfs: handle null pointers while printing node name and pathKonstantin Khlebnikov2017-02-101-0/+10
|/ | | | | | | | | | Null kernfs nodes could be found at cgroups during construction. It seems safer to handle these null pointers right in kernfs in the same way as printf prints "(null)" for null pointer string. Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge branch 'for-4.9' of ↵Linus Torvalds2016-10-141-67/+17
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: - tracepoints for basic cgroup management operations added - kernfs and cgroup path formatting functions updated to behave in the style of strlcpy() - non-critical bug fixes * 'for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: blkcg: Unlock blkcg_pol_mutex only once when cpd == NULL cgroup: fix error handling regressions in proc_cgroup_show() and cgroup_release_agent() cpuset: fix error handling regression in proc_cpuset_show() cgroup: add tracepoints for basic operations cgroup: make cgroup_path() and friends behave in the style of strlcpy() kernfs: remove kernfs_path_len() kernfs: make kernfs_path*() behave in the style of strlcpy() kernfs: add dummy implementation of kernfs_path_from_node()
| * kernfs: remove kernfs_path_len()Tejun Heo2016-08-101-23/+0
| | | | | | | | | | | | | | | | | | It doesn't have any in-kernel user and the same result can be obtained from kernfs_path(@kn, NULL, 0). Remove it. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Serge Hallyn <serge.hallyn@ubuntu.com>
| * kernfs: make kernfs_path*() behave in the style of strlcpy()Tejun Heo2016-08-101-44/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kernfs_path*() functions always return the length of the full path but the path content is undefined if the length is larger than the provided buffer. This makes its behavior different from strlcpy() and requires error handling in all its users even when they don't care about truncation. In addition, the implementation can actully be simplified by making it behave properly in strlcpy() style. * Update kernfs_path_from_node_locked() to always fill up the buffer with path. If the buffer is not large enough, the output is truncated and terminated. * kernfs_path() no longer needs error handling. Make it a simple inline wrapper around kernfs_path_from_node(). * sysfs_warn_dup()'s use of kernfs_path() doesn't need error handling. Updated accordingly. * cgroup_path()'s use of kernfs_path() updated to retain the old behavior. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>
* | Merge branch 'for-linus' of ↵Linus Torvalds2016-10-101-1/+5
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more vfs updates from Al Viro: ">rename2() work from Miklos + current_time() from Deepa" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: Replace current_fs_time() with current_time() fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps fs: Replace CURRENT_TIME with current_time() for inode timestamps fs: proc: Delete inode time initializations in proc_alloc_inode() vfs: Add current_time() api vfs: add note about i_op->rename changes to porting fs: rename "rename2" i_op to "rename" vfs: remove unused i_op->rename fs: make remaining filesystems use .rename2 libfs: support RENAME_NOREPLACE in simple_rename() fs: support RENAME_NOREPLACE for local filesystems ncpfs: fix unused variable warning
| * | fs: rename "rename2" i_op to "rename"Miklos Szeredi2016-09-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | Generated patch: sed -i "s/\.rename2\t/\.rename\t\t/" `git grep -wl rename2` sed -i "s/\brename2\b/rename/g" `git grep -wl rename2` Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * | fs: make remaining filesystems use .rename2Miklos Szeredi2016-09-271-2/+6
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is trivial to do: - add flags argument to foo_rename() - check if flags is zero - assign foo_rename() to .rename2 instead of .rename This doesn't mean it's impossible to support RENAME_NOREPLACE for these filesystems, but it is not trivial, like for local filesystems. RENAME_NOREPLACE must guarantee atomicity (i.e. it shouldn't be possible for a file to be created on one host while it is overwritten by rename on another host). Filesystems converted: 9p, afs, ceph, coda, ecryptfs, kernfs, lustre, ncpfs, nfs, ocfs2, orangefs. After this, we can get rid of the duplicate interfaces for rename. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: David Howells <dhowells@redhat.com> [AFS] Acked-by: Mike Marshall <hubcap@omnibond.com> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ilya Dryomov <idryomov@gmail.com> Cc: Jan Harkes <jaharkes@cs.cmu.edu> Cc: Tyler Hicks <tyhicks@canonical.com> Cc: Oleg Drokin <oleg.drokin@intel.com> Cc: Trond Myklebust <trond.myklebust@primarydata.com> Cc: Mark Fasheh <mfasheh@suse.com>
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