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path: root/fs/fuse/dev.c
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2024-03-06fuse: Use the high bit of request ID for indicating resend requestsZhao Chen
Some FUSE daemons want to know if the received request is a resend request. The high bit of the fuse request ID is utilized for indicating this, enabling the receiver to perform appropriate handling. The init flag "FUSE_HAS_RESEND" is added to indicate this feature. Signed-off-by: Zhao Chen <winters.zc@antgroup.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-03-06fuse: Introduce a new notification type for resend pending requestsZhao Chen
When a FUSE daemon panics and failover, we aim to minimize the impact on applications by reusing the existing FUSE connection. During this process, another daemon is employed to preserve the FUSE connection's file descriptor. The new started FUSE Daemon will takeover the fd and continue to provide service. However, it is possible for some inflight requests to be lost and never returned. As a result, applications awaiting replies would become stuck forever. To address this, we can resend these pending requests to the new started FUSE daemon. This patch introduces a new notification type "FUSE_NOTIFY_RESEND", which can trigger resending of the pending requests, ensuring they are properly processed again. Signed-off-by: Zhao Chen <winters.zc@antgroup.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-03-05fuse: implement ioctls to manage backing filesAmir Goldstein
FUSE server calls the FUSE_DEV_IOC_BACKING_OPEN ioctl with a backing file descriptor. If the call succeeds, a backing file identifier is returned. A later change will be using this backing file id in a reply to OPEN request with the flag FOPEN_PASSTHROUGH to setup passthrough of file operations on the open FUSE file to the backing file. The FUSE server should call FUSE_DEV_IOC_BACKING_CLOSE ioctl to close the backing file by its id. This can be done at any time, but if an open reply with FOPEN_PASSTHROUGH flag is still in progress, the open may fail if the backing file is closed before the fuse file was opened. Setting up backing files requires a server with CAP_SYS_ADMIN privileges. For the backing file to be successfully setup, the backing file must implement both read_iter and write_iter file operations. The limitation on the level of filesystem stacking allowed for the backing file is enforced before setting up the backing file. Signed-off-by: Alessio Balsini <balsini@android.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-02-23fuse: factor out helper for FUSE_DEV_IOC_CLONEAmir Goldstein
In preparation to adding more fuse dev ioctls. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2023-04-20fuse_dev_ioctl(): switch to fdget()Al Viro
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2023-01-26fuse: fix all W=1 kernel-doc warningsRandy Dunlap
Use correct function name in kernel-doc notation. (1) Don't use "/**" to begin non-kernel-doc comments. (3) Fixes these warnings: fs/fuse/cuse.c:272: warning: expecting prototype for cuse_parse_dev_info(). Prototype was for cuse_parse_devinfo() instead fs/fuse/dev.c:212: warning: expecting prototype for A new request is available, wake fiq(). Prototype was for fuse_dev_wake_and_unlock() instead fs/fuse/dir.c:149: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * Mark the attributes as stale due to an atime change. Avoid the invalidate if fs/fuse/file.c:656: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * In case of short read, the caller sets 'pos' to the position of Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2023-01-26fuse: add request extensionMiklos Szeredi
Will need to add supplementary groups to create messages, so add the general concept of a request extension. A request extension is appended to the end of the main request. It has a header indicating the size and type of the extension. The create security context (fuse_secctx_*) is similar to the generic request extension, so include that as well in a backward compatible manner. Add the total extension length to the request header. The offset of the extension block within the request can be calculated by: inh->len - inh->total_extlen * 8 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2022-12-13Merge tag 'mm-stable-2022-12-13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - More userfaultfs work from Peter Xu - Several convert-to-folios series from Sidhartha Kumar and Huang Ying - Some filemap cleanups from Vishal Moola - David Hildenbrand added the ability to selftest anon memory COW handling - Some cpuset simplifications from Liu Shixin - Addition of vmalloc tracing support by Uladzislau Rezki - Some pagecache folioifications and simplifications from Matthew Wilcox - A pagemap cleanup from Kefeng Wang: we have VM_ACCESS_FLAGS, so use it - Miguel Ojeda contributed some cleanups for our use of the __no_sanitize_thread__ gcc keyword. This series should have been in the non-MM tree, my bad - Naoya Horiguchi improved the interaction between memory poisoning and memory section removal for huge pages - DAMON cleanups and tuneups from SeongJae Park - Tony Luck fixed the handling of COW faults against poisoned pages - Peter Xu utilized the PTE marker code for handling swapin errors - Hugh Dickins reworked compound page mapcount handling, simplifying it and making it more efficient - Removal of the autonuma savedwrite infrastructure from Nadav Amit and David Hildenbrand - zram support for multiple compression streams from Sergey Senozhatsky - David Hildenbrand reworked the GUP code's R/O long-term pinning so that drivers no longer need to use the FOLL_FORCE workaround which didn't work very well anyway - Mel Gorman altered the page allocator so that local IRQs can remnain enabled during per-cpu page allocations - Vishal Moola removed the try_to_release_page() wrapper - Stefan Roesch added some per-BDI sysfs tunables which are used to prevent network block devices from dirtying excessive amounts of pagecache - David Hildenbrand did some cleanup and repair work on KSM COW breaking - Nhat Pham and Johannes Weiner have implemented writeback in zswap's zsmalloc backend - Brian Foster has fixed a longstanding corner-case oddity in file[map]_write_and_wait_range() - sparse-vmemmap changes for MIPS, LoongArch and NIOS2 from Feiyang Chen - Shiyang Ruan has done some work on fsdax, to make its reflink mode work better under xfstests. Better, but still not perfect - Christoph Hellwig has removed the .writepage() method from several filesystems. They only need .writepages() - Yosry Ahmed wrote a series which fixes the memcg reclaim target beancounting - David Hildenbrand has fixed some of our MM selftests for 32-bit machines - Many singleton patches, as usual * tag 'mm-stable-2022-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (313 commits) mm/hugetlb: set head flag before setting compound_order in __prep_compound_gigantic_folio mm: mmu_gather: allow more than one batch of delayed rmaps mm: fix typo in struct pglist_data code comment kmsan: fix memcpy tests mm: add cond_resched() in swapin_walk_pmd_entry() mm: do not show fs mm pc for VM_LOCKONFAULT pages selftests/vm: ksm_functional_tests: fixes for 32bit selftests/vm: cow: fix compile warning on 32bit selftests/vm: madv_populate: fix missing MADV_POPULATE_(READ|WRITE) definitions mm/gup_test: fix PIN_LONGTERM_TEST_READ with highmem mm,thp,rmap: fix races between updates of subpages_mapcount mm: memcg: fix swapcached stat accounting mm: add nodes= arg to memory.reclaim mm: disable top-tier fallback to reclaim on proactive reclaim selftests: cgroup: make sure reclaim target memcg is unprotected selftests: cgroup: refactor proactive reclaim code to reclaim_until() mm: memcg: fix stale protection of reclaim target memcg mm/mmap: properly unaccount memory on mas_preallocate() failure omfs: remove ->writepage jfs: remove ->writepage ...
2022-12-11fuse: convert fuse_try_move_page() to use foliosVishal Moola (Oracle)
Converts the function to try to move folios instead of pages. Also converts fuse_check_page() to fuse_get_folio() since this is its only caller. This change removes 15 calls to compound_head(). Link: https://lkml.kernel.org/r/20221101175326.13265-3-vishal.moola@gmail.com Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Acked-by: Miklos Szeredi <mszeredi@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-12-11filemap: convert replace_page_cache_page() to replace_page_cache_folio()Vishal Moola (Oracle)
Patch series "Removing the lru_cache_add() wrapper". This patchset replaces all calls of lru_cache_add() with the folio equivalent: folio_add_lru(). This is allows us to get rid of the wrapper The series passes xfstests and the userfaultfd selftests. This patch (of 5): Eliminates 7 calls to compound_head(). Link: https://lkml.kernel.org/r/20221101175326.13265-1-vishal.moola@gmail.com Link: https://lkml.kernel.org/r/20221101175326.13265-2-vishal.moola@gmail.com Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-23fuse: Remove user_ns check for FUSE_DEV_IOC_CLONEJann Horn
Commit 8ed1f0e22f49e ("fs/fuse: fix ioctl type confusion") fixed a type confusion bug by adding an ->f_op comparison. Based on some off-list discussion back then, another check was added to compare the f_cred->user_ns. This is not for security reasons, but was based on the idea that a FUSE device FD should be using the UID/GID mappings of its f_cred->user_ns, and those translations are done using fc->user_ns, which matches the f_cred->user_ns of the initial FUSE device FD thanks to the check in fuse_fill_super(). See also commit 8cb08329b0809 ("fuse: Support fuse filesystems outside of init_user_ns"). But FUSE_DEV_IOC_CLONE is, at a higher level, a *cloning* operation that copies an existing context (with a weird API that involves first opening /dev/fuse, then tying the resulting new FUSE device FD to an existing FUSE instance). So if an application is already passing FUSE FDs across userns boundaries and dealing with the resulting ID mapping complications somehow, it doesn't make much sense to block this cloning operation. I've heard that this check is an obstacle for some folks, and I don't see a good reason to keep it, so remove it. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2022-11-23fuse: add "expire only" mode to FUSE_NOTIFY_INVAL_ENTRYMiklos Szeredi
Add a flag to entry expiration that lets the filesystem expire a dentry without kicking it out from the cache immediately. This makes a difference for overmounted dentries, where plain invalidation would detach all submounts before dropping the dentry from the cache. If only expiry is set on the dentry, then any overmounts are left alone and until ->d_revalidate() is called. Note: ->d_revalidate() is not called for the case of following a submount, so invalidation will only be triggered for the non-overmounted case. The dentry could also be mounted in a different mount instance, in which case any submounts will still be detached. Suggested-by: Jakob Blomer <jblomer@cern.ch> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2022-09-26mm: multi-gen LRU: groundworkYu Zhao
Evictable pages are divided into multiple generations for each lruvec. The youngest generation number is stored in lrugen->max_seq for both anon and file types as they are aged on an equal footing. The oldest generation numbers are stored in lrugen->min_seq[] separately for anon and file types as clean file pages can be evicted regardless of swap constraints. These three variables are monotonically increasing. Generation numbers are truncated into order_base_2(MAX_NR_GENS+1) bits in order to fit into the gen counter in folio->flags. Each truncated generation number is an index to lrugen->lists[]. The sliding window technique is used to track at least MIN_NR_GENS and at most MAX_NR_GENS generations. The gen counter stores a value within [1, MAX_NR_GENS] while a page is on one of lrugen->lists[]. Otherwise it stores 0. There are two conceptually independent procedures: "the aging", which produces young generations, and "the eviction", which consumes old generations. They form a closed-loop system, i.e., "the page reclaim". Both procedures can be invoked from userspace for the purposes of working set estimation and proactive reclaim. These techniques are commonly used to optimize job scheduling (bin packing) in data centers [1][2]. To avoid confusion, the terms "hot" and "cold" will be applied to the multi-gen LRU, as a new convention; the terms "active" and "inactive" will be applied to the active/inactive LRU, as usual. The protection of hot pages and the selection of cold pages are based on page access channels and patterns. There are two access channels: one through page tables and the other through file descriptors. The protection of the former channel is by design stronger because: 1. The uncertainty in determining the access patterns of the former channel is higher due to the approximation of the accessed bit. 2. The cost of evicting the former channel is higher due to the TLB flushes required and the likelihood of encountering the dirty bit. 3. The penalty of underprotecting the former channel is higher because applications usually do not prepare themselves for major page faults like they do for blocked I/O. E.g., GUI applications commonly use dedicated I/O threads to avoid blocking rendering threads. There are also two access patterns: one with temporal locality and the other without. For the reasons listed above, the former channel is assumed to follow the former pattern unless VM_SEQ_READ or VM_RAND_READ is present; the latter channel is assumed to follow the latter pattern unless outlying refaults have been observed [3][4]. The next patch will address the "outlying refaults". Three macros, i.e., LRU_REFS_WIDTH, LRU_REFS_PGOFF and LRU_REFS_MASK, used later are added in this patch to make the entire patchset less diffy. A page is added to the youngest generation on faulting. The aging needs to check the accessed bit at least twice before handing this page over to the eviction. The first check takes care of the accessed bit set on the initial fault; the second check makes sure this page has not been used since then. This protocol, AKA second chance, requires a minimum of two generations, hence MIN_NR_GENS. [1] https://dl.acm.org/doi/10.1145/3297858.3304053 [2] https://dl.acm.org/doi/10.1145/3503222.3507731 [3] https://lwn.net/Articles/495543/ [4] https://lwn.net/Articles/815342/ Link: https://lkml.kernel.org/r/20220918080010.2920238-6-yuzhao@google.com Signed-off-by: Yu Zhao <yuzhao@google.com> Acked-by: Brian Geffon <bgeffon@google.com> Acked-by: Jan Alexander Steffens (heftig) <heftig@archlinux.org> Acked-by: Oleksandr Natalenko <oleksandr@natalenko.name> Acked-by: Steven Barrett <steven@liquorix.net> Acked-by: Suleiman Souhlal <suleiman@google.com> Tested-by: Daniel Byrne <djbyrne@mtu.edu> Tested-by: Donald Carr <d@chaos-reins.com> Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Tested-by: Konstantin Kharlamov <Hi-Angel@yandex.ru> Tested-by: Shuang Zhai <szhai2@cs.rochester.edu> Tested-by: Sofia Trinh <sofia.trinh@edi.works> Tested-by: Vaibhav Jain <vaibhav@linux.ibm.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Barry Song <baohua@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Larabel <Michael@MichaelLarabel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-08iov_iter: advancing variants of iov_iter_get_pages{,_alloc}()Al Viro
Most of the users immediately follow successful iov_iter_get_pages() with advancing by the amount it had returned. Provide inline wrappers doing that, convert trivial open-coded uses of those. BTW, iov_iter_get_pages() never returns more than it had been asked to; such checks in cifs ought to be removed someday... Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08new iov_iter flavour - ITER_UBUFAl Viro
Equivalent of single-segment iovec. Initialized by iov_iter_ubuf(), checked for by iter_is_ubuf(), otherwise behaves like ITER_IOVEC ones. We are going to expose the things like ->write_iter() et.al. to those in subsequent commits. New predicate (user_backed_iter()) that is true for ITER_IOVEC and ITER_UBUF; places like direct-IO handling should use that for checking that pages we modify after getting them from iov_iter_get_pages() would need to be dirtied. DO NOT assume that replacing iter_is_iovec() with user_backed_iter() will solve all problems - there's code that uses iter_is_iovec() to decide how to poke around in iov_iter guts and for that the predicate replacement obviously won't suffice. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-03-22fuse: remove reliance on bdi congestionNeilBrown
The bdi congestion tracking in not widely used and will be removed. Fuse is one of a small number of filesystems that uses it, setting both the sync (read) and async (write) congestion flags at what it determines are appropriate times. The only remaining effect of the sync flag is to cause read-ahead to be skipped. The only remaining effect of the async flag is to cause (some) WB_SYNC_NONE writes to be skipped. So instead of setting the flags, change: - .readahead to stop when it has submitted all non-async pages for read. - .writepages to do nothing if WB_SYNC_NONE and the flag would be set - .writepage to return AOP_WRITEPAGE_ACTIVATE if WB_SYNC_NONE and the flag would be set. The writepages change causes a behavioural change in that pageout() can now return PAGE_ACTIVATE instead of PAGE_KEEP, so SetPageActive() will be called on the page which (I think) will further delay the next attempt at writeout. This might be a good thing. Link: https://lkml.kernel.org/r/164549983737.9187.2627117501000365074.stgit@noble.brown Signed-off-by: NeilBrown <neilb@suse.de> Cc: Anna Schumaker <Anna.Schumaker@Netapp.com> Cc: Chao Yu <chao@kernel.org> Cc: Darrick J. Wong <djwong@kernel.org> Cc: Ilya Dryomov <idryomov@gmail.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jeff Layton <jlayton@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Lars Ellenberg <lars.ellenberg@linbit.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Paolo Valente <paolo.valente@linaro.org> Cc: Philipp Reisner <philipp.reisner@linbit.com> Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-07fuse: fix pipe buffer lifetime for direct_ioMiklos Szeredi
In FOPEN_DIRECT_IO mode, fuse_file_write_iter() calls fuse_direct_write_iter(), which normally calls fuse_direct_io(), which then imports the write buffer with fuse_get_user_pages(), which uses iov_iter_get_pages() to grab references to userspace pages instead of actually copying memory. On the filesystem device side, these pages can then either be read to userspace (via fuse_dev_read()), or splice()d over into a pipe using fuse_dev_splice_read() as pipe buffers with &nosteal_pipe_buf_ops. This is wrong because after fuse_dev_do_read() unlocks the FUSE request, the userspace filesystem can mark the request as completed, causing write() to return. At that point, the userspace filesystem should no longer have access to the pipe buffer. Fix by copying pages coming from the user address space to new pipe buffers. Reported-by: Jann Horn <jannh@google.com> Fixes: c3021629a0d8 ("fuse: support splice() reading from fuse device") Cc: <stable@vger.kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-11-25fuse: release pipe buf after last useMiklos Szeredi
Checking buf->flags should be done before the pipe_buf_release() is called on the pipe buffer, since releasing the buffer might modify the flags. This is exactly what page_cache_pipe_buf_release() does, and which results in the same VM_BUG_ON_PAGE(PageLRU(page)) that the original patch was trying to fix. Reported-by: Justin Forbes <jmforbes@linuxtx.org> Fixes: 712a951025c0 ("fuse: fix page stealing") Cc: <stable@vger.kernel.org> # v2.6.35 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-11-02fuse: fix page stealingMiklos Szeredi
It is possible to trigger a crash by splicing anon pipe bufs to the fuse device. The reason for this is that anon_pipe_buf_release() will reuse buf->page if the refcount is 1, but that page might have already been stolen and its flags modified (e.g. PG_lru added). This happens in the unlikely case of fuse_dev_splice_write() getting around to calling pipe_buf_release() after a page has been stolen, added to the page cache and removed from the page cache. Fix by calling pipe_buf_release() right after the page was inserted into the page cache. In this case the page has an elevated refcount so any release function will know that the page isn't reusable. Reported-by: Frank Dinoff <fdinoff@google.com> Link: https://lore.kernel.org/r/CAAmZXrsGg2xsP1CK+cbuEMumtrqdvD-NKnWzhNcvn71RV3c1yw@mail.gmail.com/ Fixes: dd3bb14f44a6 ("fuse: support splice() writing to fuse device") Cc: <stable@vger.kernel.org> # v2.6.35 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28fuse: always invalidate attributes after writesMiklos Szeredi
Extend the fuse_write_update_attr() helper to invalidate cached attributes after a write. This has already been done in all cases except in fuse_notify_store(), so this is mostly a cleanup. fuse_direct_write_iter() calls fuse_direct_IO() which already calls fuse_write_update_attr(), so don't repeat that again in the former. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28fuse: rename fuse_write_update_size()Miklos Szeredi
This function already updates the attr_version in fuse_inode, regardless of whether the size was changed or not. Rename the helper to fuse_write_update_attr() to reflect the more generic nature. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-22fuse: use kmap_local_page()Peng Hao
Due to the introduction of kmap_local_*, the storage of slots used for short-term mapping has changed from per-CPU to per-thread. kmap_atomic() disable preemption, while kmap_local_*() only disable migration. There is no need to disable preemption in several kamp_atomic places used in fuse. Link: https://lwn.net/Articles/836144/ Signed-off-by: Peng Hao <flyingpeng@tencent.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-08-04fuse: fix use after free in fuse_read_interrupt()Miklos Szeredi
There is a potential race between fuse_read_interrupt() and fuse_request_end(). TASK1 in fuse_read_interrupt(): delete req->intr_entry (while holding fiq->lock) TASK2 in fuse_request_end(): req->intr_entry is empty -> skip fiq->lock wake up TASK3 TASK3 request is freed TASK1 in fuse_read_interrupt(): dereference req->in.h.unique ***BAM*** Fix by always grabbing fiq->lock if the request was ever interrupted (FR_INTERRUPTED set) thereby serializing with concurrent fuse_read_interrupt() calls. FR_INTERRUPTED is set before the request is queued on fiq->interrupts. Dequeing the request is done with list_del_init() but FR_INTERRUPTED is not cleared in this case. Reported-by: lijiazi <lijiazi@xiaomi.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-22virtiofs: Fix spelling mistakesZheng Yongjun
Fix some spelling mistakes in comments: refernce ==> reference happnes ==> happens threhold ==> threshold splitted ==> split mached ==> matched Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-22fuse: reject internal errnoMiklos Szeredi
Don't allow userspace to report errors that could be kernel-internal. Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com> Fixes: 334f485df85a ("[PATCH] FUSE - device functions") Cc: <stable@vger.kernel.org> # v2.6.14 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-22fuse: check connected before queueing on fpq->ioMiklos Szeredi
A request could end up on the fpq->io list after fuse_abort_conn() has reset fpq->connected and aborted requests on that list: Thread-1 Thread-2 ======== ======== ->fuse_simple_request() ->shutdown ->__fuse_request_send() ->queue_request() ->fuse_abort_conn() ->fuse_dev_do_read() ->acquire(fpq->lock) ->wait_for(fpq->lock) ->set err to all req's in fpq->io ->release(fpq->lock) ->acquire(fpq->lock) ->add req to fpq->io After the userspace copy is done the request will be ended, but req->out.h.error will remain uninitialized. Also the copy might block despite being already aborted. Fix both issues by not allowing the request to be queued on the fpq->io list after fuse_abort_conn() has processed this list. Reported-by: Pradeep P V K <pragalla@codeaurora.org> Fixes: fd22d62ed0c3 ("fuse: no fc->lock for iqueue parts") Cc: <stable@vger.kernel.org> # v4.2 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-18fuse: ignore PG_workingset after stealingMiklos Szeredi
Fix the "fuse: trying to steal weird page" warning. Description from Johannes Weiner: "Think of it as similar to PG_active. It's just another usage/heat indicator of file and anon pages on the reclaim LRU that, unlike PG_active, persists across deactivation and even reclaim (we store it in the page cache / swapper cache tree until the page refaults). So if fuse accepts pages that can legally have PG_active set, PG_workingset is fine too." Reported-by: Thomas Lindroth <thomas.lindroth@gmail.com> Fixes: 1899ad18c607 ("mm: workingset: tell cache transitions from workingset thrashing") Cc: <stable@vger.kernel.org> # v4.20 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-14fuse: fix matching of FUSE_DEV_IOC_CLONE commandAlessio Balsini
With commit f8425c939663 ("fuse: 32-bit user space ioctl compat for fuse device") the matching constraints for the FUSE_DEV_IOC_CLONE ioctl command are relaxed, limited to the testing of command type and number. As Arnd noticed, this is wrong as it wouldn't ensure the correctness of the data size or direction for the received FUSE device ioctl. Fix by bringing back the comparison of the ioctl received by the FUSE device to the originally generated FUSE_DEV_IOC_CLONE. Fixes: f8425c939663 ("fuse: 32-bit user space ioctl compat for fuse device") Reported-by: Arnd Bergmann <arnd@kernel.org> Signed-off-by: Alessio Balsini <balsini@android.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-03-16fuse: 32-bit user space ioctl compat for fuse deviceAlessio Balsini
With a 64-bit kernel build the FUSE device cannot handle ioctl requests coming from 32-bit user space. This is due to the ioctl command translation that generates different command identifiers that thus cannot be used for direct comparisons without proper manipulation. Explicitly extract type and number from the ioctl command to enable 32-bit user space compatibility on 64-bit kernel builds. Signed-off-by: Alessio Balsini <balsini@android.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-02-24mm/filemap: remove unused parameter and change to void type for ↵Baolin Wang
replace_page_cache_page() Since commit 74d609585d8b ("page cache: Add and replace pages using the XArray") was merged, the replace_page_cache_page() can not fail and always return 0, we can remove the redundant return value and void it. Moreover remove the unused gfp_mask. Link: https://lkml.kernel.org/r/609c30e5274ba15d8b90c872fd0d8ac437a9b2bb.1610071401.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-18fuse: split fuse_mount off of fuse_connMax Reitz
We want to allow submounts for the same fuse_conn, but with different superblocks so that each of the submounts has its own device ID. To do so, we need to split all mount-specific information off of fuse_conn into a new fuse_mount structure, so that multiple mounts can share a single fuse_conn. We need to take care only to perform connection-level actions once (i.e. when the fuse_conn and thus the first fuse_mount are established, or when the last fuse_mount and thus the fuse_conn are destroyed). For example, fuse_sb_destroy() must invoke fuse_send_destroy() until the last superblock is released. To do so, we keep track of which fuse_mount is the root mount and perform all fuse_conn-level actions only when this fuse_mount is involved. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-18fuse: drop fuse_conn parameter where possibleMax Reitz
With the last commit, all functions that handle some existing fuse_req no longer need to be given the associated fuse_conn, because they can get it from the fuse_req object. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-18fuse: store fuse_conn in fuse_reqMax Reitz
Every fuse_req belongs to a fuse_conn. Right now, we always know which fuse_conn that is based on the respective device, but we want to allow multiple (sub)mounts per single connection, and then the corresponding filesystem is not going to be so trivial to obtain. Storing a pointer to the associated fuse_conn in every fuse_req will allow us to trivially find any request's superblock (and thus filesystem) even then. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-18fuse: fix page dereference after freeMiklos Szeredi
After unlock_request() pages from the ap->pages[] array may be put (e.g. by aborting the connection) and the pages can be freed. Prevent use after free by grabbing a reference to the page before calling unlock_request(). The original patch was created by Pradeep P V K. Reported-by: Pradeep P V K <ppvk@codeaurora.org> Cc: <stable@vger.kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-06-09Merge tag 'fuse-update-5.8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse Pull fuse updates from Miklos Szeredi: - Fix a rare deadlock in virtiofs - Fix st_blocks in writeback cache mode - Fix wrong checks in splice move causing spurious warnings - Fix a race between a GETATTR request and a FUSE_NOTIFY_INVAL_INODE notification - Use rb-tree instead of linear search for pages currently under writeout by userspace - Fix copy_file_range() inconsistencies * tag 'fuse-update-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: copy_file_range should truncate cache fuse: fix copy_file_range cache issues fuse: optimize writepages search fuse: update attr_version counter on fuse_notify_inval_inode() fuse: don't check refcount after stealing page fuse: fix weird page warning fuse: use dump_page virtiofs: do not use fuse_fill_super_common() for device installation fuse: always allow query of st_dev fuse: always flush dirty data on close(2) fuse: invalidate inode attr in writeback cache mode fuse: Update stale comment in queue_interrupt() fuse: BUG_ON correction in fuse_dev_splice_write() virtiofs: Add mount option and atime behavior to the doc virtiofs: schedule blocking async replies in separate worker
2020-06-03Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge more updates from Andrew Morton: "More mm/ work, plenty more to come Subsystems affected by this patch series: slub, memcg, gup, kasan, pagealloc, hugetlb, vmscan, tools, mempolicy, memblock, hugetlbfs, thp, mmap, kconfig" * akpm: (131 commits) arm64: mm: use ARCH_HAS_DEBUG_WX instead of arch defined x86: mm: use ARCH_HAS_DEBUG_WX instead of arch defined riscv: support DEBUG_WX mm: add DEBUG_WX support drivers/base/memory.c: cache memory blocks in xarray to accelerate lookup mm/thp: rename pmd_mknotpresent() as pmd_mkinvalid() powerpc/mm: drop platform defined pmd_mknotpresent() mm: thp: don't need to drain lru cache when splitting and mlocking THP hugetlbfs: get unmapped area below TASK_UNMAPPED_BASE for hugetlbfs sparc32: register memory occupied by kernel as memblock.memory include/linux/memblock.h: fix minor typo and unclear comment mm, mempolicy: fix up gup usage in lookup_node tools/vm/page_owner_sort.c: filter out unneeded line mm: swap: memcg: fix memcg stats for huge pages mm: swap: fix vmstats for huge pages mm: vmscan: limit the range of LRU type balancing mm: vmscan: reclaim writepage is IO cost mm: vmscan: determine anon/file pressure balance at the reclaim root mm: balance LRU lists based on relative thrashing mm: only count actual rotations as LRU reclaim cost ...
2020-06-03mm: fold and remove lru_cache_add_anon() and lru_cache_add_file()Johannes Weiner
They're the same function, and for the purpose of all callers they are equivalent to lru_cache_add(). [akpm@linux-foundation.org: fix it for local_lock changes] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Rik van Riel <riel@surriel.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Link: http://lkml.kernel.org/r/20200520232525.798933-5-hannes@cmpxchg.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03Merge branch 'work.splice' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull splice updates from Al Viro: "Christoph's assorted splice cleanups" * 'work.splice' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: rename pipe_buf ->steal to ->try_steal fs: make the pipe_buf_operations ->confirm operation optional fs: make the pipe_buf_operations ->steal operation optional trace: remove tracing_pipe_buf_ops pipe: merge anon_pipe_buf*_ops fs: simplify do_splice_from fs: simplify do_splice_to
2020-05-20fs: rename pipe_buf ->steal to ->try_stealChristoph Hellwig
And replace the arcane return value convention with a simple bool where true means success and false means failure. [AV: braino fix folded in] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-05-19fuse: don't check refcount after stealing pageMiklos Szeredi
page_count() is unstable. Unless there has been an RCU grace period between when the page was removed from the page cache and now, a speculative reference may exist from the page cache. Reported-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-05-19fuse: fix weird page warningMiklos Szeredi
When PageWaiters was added, updating this check was missed. Reported-by: Nikolaus Rath <Nikolaus@rath.org> Reported-by: Hugh Dickins <hughd@google.com> Fixes: 62906027091f ("mm: add PageWaiters indicating tasks are waiting for a page bit") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-05-19fuse: use dump_pageMiklos Szeredi
Instead of custom page dumping, use the standard helper. Reported-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-04-20docs: fix broken references to text filesMauro Carvalho Chehab
Several references got broken due to txt to ReST conversion. Several of them can be automatically fixed with: scripts/documentation-file-ref-check --fix Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> # hwtracing/coresight/Kconfig Reviewed-by: Paul E. McKenney <paulmck@kernel.org> # memory-barrier.txt Acked-by: Alex Shi <alex.shi@linux.alibaba.com> # translations/zh_CN Acked-by: Federico Vaga <federico.vaga@vaga.pv.it> # translations/it_IT Acked-by: Marc Zyngier <maz@kernel.org> # kvm/arm64 Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/6f919ddb83a33b5f2a63b6b5f0575737bb2b36aa.1586881715.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-04-20fuse: Update stale comment in queue_interrupt()Kirill Tkhai
Fixes: 04ec5af0776e "fuse: export fuse_end_request()" Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-04-20fuse: BUG_ON correction in fuse_dev_splice_write()Vasily Averin
commit 963545357202 ("fuse: reduce allocation size for splice_write") changed size of bufs array, so BUG_ON which checks the index of the array shold also be fixed. [SzM: turn BUG_ON into WARN_ON] Fixes: 963545357202 ("fuse: reduce allocation size for splice_write") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-02-13fuse: fix stack use after returnMiklos Szeredi
Normal, synchronous requests will have their args allocated on the stack. After the FR_FINISHED bit is set by receiving the reply from the userspace fuse server, the originating task may return and reuse the stack frame, resulting in an Oops if the args structure is dereferenced. Fix by setting a flag in the request itself upon initializing, indicating whether it has an asynchronous ->end() callback. Reported-by: Kyle Sanderson <kyle.leet@gmail.com> Reported-by: Michael Stapelberg <michael+lkml@stapelberg.ch> Fixes: 2b319d1f6f92 ("fuse: don't dereference req->args on finished request") Cc: <stable@vger.kernel.org> # v5.4 Tested-by: Michael Stapelberg <michael+lkml@stapelberg.ch> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-12-06pipe: Fix iteration end check in fuse_dev_splice_write()David Howells
Fix the iteration end check in fuse_dev_splice_write(). The iterator position can only be compared with == or != since wrappage may be involved. Fixes: 8cefc107ca54 ("pipe: Use head and tail pointers for the ring, not cursor and length") Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-01Merge tag 'compat-ioctl-5.5' of ↵Linus Torvalds
git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground Pull removal of most of fs/compat_ioctl.c from Arnd Bergmann: "As part of the cleanup of some remaining y2038 issues, I came to fs/compat_ioctl.c, which still has a couple of commands that need support for time64_t. In completely unrelated work, I spent time on cleaning up parts of this file in the past, moving things out into drivers instead. After Al Viro reviewed an earlier version of this series and did a lot more of that cleanup, I decided to try to completely eliminate the rest of it and move it all into drivers. This series incorporates some of Al's work and many patches of my own, but in the end stops short of actually removing the last part, which is the scsi ioctl handlers. I have patches for those as well, but they need more testing or possibly a rewrite" * tag 'compat-ioctl-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground: (42 commits) scsi: sd: enable compat ioctls for sed-opal pktcdvd: add compat_ioctl handler compat_ioctl: move SG_GET_REQUEST_TABLE handling compat_ioctl: ppp: move simple commands into ppp_generic.c compat_ioctl: handle PPPIOCGIDLE for 64-bit time_t compat_ioctl: move PPPIOCSCOMPRESS to ppp_generic compat_ioctl: unify copy-in of ppp filters tty: handle compat PPP ioctls compat_ioctl: move SIOCOUTQ out of compat_ioctl.c compat_ioctl: handle SIOCOUTQNSD af_unix: add compat_ioctl support compat_ioctl: reimplement SG_IO handling compat_ioctl: move WDIOC handling into wdt drivers fs: compat_ioctl: move FITRIM emulation into file systems gfs2: add compat_ioctl support compat_ioctl: remove unused convert_in_user macro compat_ioctl: remove last RAID handling code compat_ioctl: remove /dev/raw ioctl translation compat_ioctl: remove PCI ioctl translation compat_ioctl: remove joystick ioctl translation ...
2019-11-30Merge tag 'notifications-pipe-prep-20191115' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull pipe rework from David Howells: "This is my set of preparatory patches for building a general notification queue on top of pipes. It makes a number of significant changes: - It removes the nr_exclusive argument from __wake_up_sync_key() as this is always 1. This prepares for the next step: - Adds wake_up_interruptible_sync_poll_locked() so that poll can be woken up from a function that's holding the poll waitqueue spinlock. - Change the pipe buffer ring to be managed in terms of unbounded head and tail indices rather than bounded index and length. This means that reading the pipe only needs to modify one index, not two. - A selection of helper functions are provided to query the state of the pipe buffer, plus a couple to apply updates to the pipe indices. - The pipe ring is allowed to have kernel-reserved slots. This allows many notification messages to be spliced in by the kernel without allowing userspace to pin too many pages if it writes to the same pipe. - Advance the head and tail indices inside the pipe waitqueue lock and use wake_up_interruptible_sync_poll_locked() to poke poll without having to take the lock twice. - Rearrange pipe_write() to preallocate the buffer it is going to write into and then drop the spinlock. This allows kernel notifications to then be added the ring whilst it is filling the buffer it allocated. The read side is stalled because the pipe mutex is still held. - Don't wake up readers on a pipe if there was already data in it when we added more. - Don't wake up writers on a pipe if the ring wasn't full before we removed a buffer" * tag 'notifications-pipe-prep-20191115' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: pipe: Remove sync on wake_ups pipe: Increase the writer-wakeup threshold to reduce context-switch count pipe: Check for ring full inside of the spinlock in pipe_write() pipe: Remove redundant wakeup from pipe_write() pipe: Rearrange sequence in pipe_write() to preallocate slot pipe: Conditionalise wakeup in pipe_read() pipe: Advance tail pointer inside of wait spinlock in pipe_read() pipe: Allow pipes to have kernel-reserved slots pipe: Use head and tail pointers for the ring, not cursor and length Add wake_up_interruptible_sync_poll_locked() Remove the nr_exclusive argument from __wake_up_sync_key() pipe: Reduce #inclusion of pipe_fs_i.h
2019-11-15pipe: Allow pipes to have kernel-reserved slotsDavid Howells
Split pipe->ring_size into two numbers: (1) pipe->ring_size - indicates the hard size of the pipe ring. (2) pipe->max_usage - indicates the maximum number of pipe ring slots that userspace orchestrated events can fill. This allows for a pipe that is both writable by the general kernel notification facility and by userspace, allowing plenty of ring space for notifications to be added whilst preventing userspace from being able to pin too much unswappable kernel space. Signed-off-by: David Howells <dhowells@redhat.com>