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path: root/fs/fuse/dev.c
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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>
2019-10-31pipe: Use head and tail pointers for the ring, not cursor and lengthDavid Howells
Convert pipes to use head and tail pointers for the buffer ring rather than pointer and length as the latter requires two atomic ops to update (or a combined op) whereas the former only requires one. (1) The head pointer is the point at which production occurs and points to the slot in which the next buffer will be placed. This is equivalent to pipe->curbuf + pipe->nrbufs. The head pointer belongs to the write-side. (2) The tail pointer is the point at which consumption occurs. It points to the next slot to be consumed. This is equivalent to pipe->curbuf. The tail pointer belongs to the read-side. (3) head and tail are allowed to run to UINT_MAX and wrap naturally. They are only masked off when the array is being accessed, e.g.: pipe->bufs[head & mask] This means that it is not necessary to have a dead slot in the ring as head == tail isn't ambiguous. (4) The ring is empty if "head == tail". A helper, pipe_empty(), is provided for this. (5) The occupancy of the ring is "head - tail". A helper, pipe_occupancy(), is provided for this. (6) The number of free slots in the ring is "pipe->ring_size - occupancy". A helper, pipe_space_for_user() is provided to indicate how many slots userspace may use. (7) The ring is full if "head - tail >= pipe->ring_size". A helper, pipe_full(), is provided for this. Signed-off-by: David Howells <dhowells@redhat.com>
2019-10-23compat_ioctl: move more drivers to compat_ptr_ioctlArnd Bergmann
The .ioctl and .compat_ioctl file operations have the same prototype so they can both point to the same function, which works great almost all the time when all the commands are compatible. One exception is the s390 architecture, where a compat pointer is only 31 bit wide, and converting it into a 64-bit pointer requires calling compat_ptr(). Most drivers here will never run in s390, but since we now have a generic helper for it, it's easy enough to use it consistently. I double-checked all these drivers to ensure that all ioctl arguments are used as pointers or are ignored, but are not interpreted as integer values. Acked-by: Jason Gunthorpe <jgg@mellanox.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Acked-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: David Sterba <dsterba@suse.com> Acked-by: Darren Hart (VMware) <dvhart@infradead.org> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org> Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-10-21fuse: don't dereference req->args on finished requestMiklos Szeredi
Move the check for async request after check for the request being already finished and done with. Reported-by: syzbot+ae0bb7aae3de6b4594e2@syzkaller.appspotmail.com Fixes: d49937749fef ("fuse: stop copying args to fuse_req") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-24fuse: Make fuse_args_to_req staticYueHaibing
Fix sparse warning: fs/fuse/dev.c:468:6: warning: symbol 'fuse_args_to_req' was not declared. Should it be static? Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: YueHaibing <yuehaibing@huawei.com> Fixes: 68583165f962 ("fuse: add pages to fuse_args") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-24fuse: unexport fuse_put_requestArnd Bergmann
This function has been made static, which now causes a compile-time warning: WARNING: "fuse_put_request" [vmlinux] is a static EXPORT_SYMBOL_GPL Remove the unneeded export. Fixes: 66abc3599c3c ("fuse: unexport request ops") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-12fuse: separate fuse device allocation and installation in fuse_connVivek Goyal
As of now fuse_dev_alloc() both allocates a fuse device and installs it in fuse_conn list. fuse_dev_alloc() can fail if fuse_device allocation fails. virtio-fs needs to initialize multiple fuse devices (one per virtio queue). It initializes one fuse device as part of call to fuse_fill_super_common() and rest of the devices are allocated and installed after that. But, we can't afford to fail after calling fuse_fill_super_common() as we don't have a way to undo all the actions done by fuse_fill_super_common(). So to avoid failures after the call to fuse_fill_super_common(), pre-allocate all fuse devices early and install them into fuse connection later. This patch provides two separate helpers for fuse device allocation and fuse device installation in fuse_conn. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-12fuse: add fuse_iqueue_ops callbacksStefan Hajnoczi
The /dev/fuse device uses fiq->waitq and fasync to signal that requests are available. These mechanisms do not apply to virtio-fs. This patch introduces callbacks so alternative behavior can be used. Note that queue_interrupt() changes along these lines: spin_lock(&fiq->waitq.lock); wake_up_locked(&fiq->waitq); + kill_fasync(&fiq->fasync, SIGIO, POLL_IN); spin_unlock(&fiq->waitq.lock); - kill_fasync(&fiq->fasync, SIGIO, POLL_IN); Since queue_request() and queue_forget() also call kill_fasync() inside the spinlock this should be safe. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-12fuse: export fuse_dequeue_forget() functionVivek Goyal
File systems like virtio-fs need to do not have to play directly with forget list data structures. There is a helper function use that instead. Rename dequeue_forget() to fuse_dequeue_forget() and export it so that stacked filesystems can use it. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-12fuse: export fuse_get_unique()Stefan Hajnoczi
virtio-fs will need unique IDs for FORGET requests from outside fs/fuse/dev.c. Make the symbol visible. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-12fuse: export fuse_len_args()Stefan Hajnoczi
virtio-fs will need to query the length of fuse_arg lists. Make the symbol visible. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-12fuse: export fuse_end_request()Stefan Hajnoczi
virtio-fs will need to complete requests from outside fs/fuse/dev.c. Make the symbol visible. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10fuse: stop copying pages to fuse_reqMiklos Szeredi
The page array pointers are also duplicated across fuse_args_pages and fuse_req. Get rid of the fuse_req ones. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10fuse: stop copying args to fuse_reqMiklos Szeredi
No need to duplicate the argument arrays in fuse_req, so just dereference req->args instead of copying to the fuse_req internal ones. This allows further cleanup of the fuse_req structure. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10fuse: simplify request allocationMiklos Szeredi
Page arrays are not allocated together with the request anymore. Get rid of the dead code Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10fuse: unexport request opsMiklos Szeredi
All requests are now sent with one of the fuse_simple_... helpers. Get rid of the old api from the fuse internal header. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10fuse: convert retrieve to simple apiMiklos Szeredi
Rename fuse_request_send_notify_reply() to fuse_simple_notify_reply() and convert to passing fuse_args instead of fuse_req. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10fuse: convert writepages to simple apiMiklos Szeredi
Derive fuse_writepage_args from fuse_io_args. Sending the request is tricky since it was done with fi->lock held, hence we must either use atomic allocation or release the lock. Both are possible so try atomic first and if it fails, release the lock and do the regular allocation with GFP_NOFS and __GFP_NOFAIL. Both flags are necessary for correct operation. Move the page realloc function from dev.c to file.c and convert to using fuse_writepage_args. The last caller of fuse_write_fill() is gone, so get rid of it. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10fuse: add simple background helperMiklos Szeredi
Create a helper named fuse_simple_background() that is similar to fuse_simple_request(). Unlike the latter, it returns immediately and calls the supplied 'end' callback when the reply is received. The supplied 'args' pointer is stored in 'fuse_req' which allows the callback to interpret the output arguments decoded from the reply. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10fuse: convert ioctl to simple apiMiklos Szeredi
fuse_simple_request() is converted to return length of last (instead of single) out arg, since FUSE_IOCTL_OUT has two out args, the second of which is variable length. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10fuse: move page allocMiklos Szeredi
fuse_req_pages_alloc() is moved to file.c, since its internal use by the device code will eventually be removed. Rename to fuse_pages_alloc() to signify that it's not only usable for fuse_req page array. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10fuse: add pages to fuse_argsMiklos Szeredi
Derive fuse_args_pages from fuse_args. This is used to handle requests which use pages for input or output. The related flags are added to fuse_args. New FR_ALLOC_PAGES flags is added to indicate whether the page arrays in fuse_req need to be freed by fuse_put_request() or not. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10fuse: add nocreds to fuse_argsMiklos Szeredi
In some cases it makes no sense to set pid/uid/gid fields in the request header. Allow fuse_simple_background() to omit these. This is only required in the "force" case, so for now just WARN if set otherwise. Fold fuse_get_req_nofail_nopages() into its only caller. Comment is obsolete anyway. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10fuse: convert fuse_force_forget() to simple apiMiklos Szeredi
Move this function to the readdir.c where its only caller resides. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10fuse: add noreply to fuse_argsMiklos Szeredi
This will be used by fuse_force_forget(). We can expand fuse_request_send() into fuse_simple_request(). The FR_WAITING bit has already been set, no need to check. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10fuse: convert flush to simple apiMiklos Szeredi
Add 'force' to fuse_args and use fuse_get_req_nofail_nopages() to allocate the request in that case. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10fuse: simplify 'nofail' requestMiklos Szeredi
Instead of complex games with a reserved request, just use __GFP_NOFAIL. Both calers (flush, readdir) guarantee that connection was already initialized, so no need to wait for fc->initialized. Also remove unneeded clearing of FR_BACKGROUND flag. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10fuse: flatten 'struct fuse_args'Miklos Szeredi
...to make future expansion simpler. The hiearachical structure is a historical thing that does not serve any practical purpose. The generated code is excatly the same before and after the patch. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10fuse: fix deadlock with aio poll and fuse_iqueue::waitq.lockEric Biggers
When IOCB_CMD_POLL is used on the FUSE device, aio_poll() disables IRQs and takes kioctx::ctx_lock, then fuse_iqueue::waitq.lock. This may have to wait for fuse_iqueue::waitq.lock to be released by one of many places that take it with IRQs enabled. Since the IRQ handler may take kioctx::ctx_lock, lockdep reports that a deadlock is possible. Fix it by protecting the state of struct fuse_iqueue with a separate spinlock, and only accessing fuse_iqueue::waitq using the versions of the waitqueue functions which do IRQ-safe locking internally. Reproducer: #include <fcntl.h> #include <stdio.h> #include <sys/mount.h> #include <sys/stat.h> #include <sys/syscall.h> #include <unistd.h> #include <linux/aio_abi.h> int main() { char opts[128]; int fd = open("/dev/fuse", O_RDWR); aio_context_t ctx = 0; struct iocb cb = { .aio_lio_opcode = IOCB_CMD_POLL, .aio_fildes = fd }; struct iocb *cbp = &cb; sprintf(opts, "fd=%d,rootmode=040000,user_id=0,group_id=0", fd); mkdir("mnt", 0700); mount("foo", "mnt", "fuse", 0, opts); syscall(__NR_io_setup, 1, &ctx); syscall(__NR_io_submit, ctx, 1, &cbp); } Beginning of lockdep output: ===================================================== WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected 5.3.0-rc5 #9 Not tainted ----------------------------------------------------- syz_fuse/135 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: 000000003590ceda (&fiq->waitq){+.+.}, at: spin_lock include/linux/spinlock.h:338 [inline] 000000003590ceda (&fiq->waitq){+.+.}, at: aio_poll fs/aio.c:1751 [inline] 000000003590ceda (&fiq->waitq){+.+.}, at: __io_submit_one.constprop.0+0x203/0x5b0 fs/aio.c:1825 and this task is already holding: 0000000075037284 (&(&ctx->ctx_lock)->rlock){..-.}, at: spin_lock_irq include/linux/spinlock.h:363 [inline] 0000000075037284 (&(&ctx->ctx_lock)->rlock){..-.}, at: aio_poll fs/aio.c:1749 [inline] 0000000075037284 (&(&ctx->ctx_lock)->rlock){..-.}, at: __io_submit_one.constprop.0+0x1f4/0x5b0 fs/aio.c:1825 which would create a new lock dependency: (&(&ctx->ctx_lock)->rlock){..-.} -> (&fiq->waitq){+.+.} but this new dependency connects a SOFTIRQ-irq-safe lock: (&(&ctx->ctx_lock)->rlock){..-.} [...] Reported-by: syzbot+af05535bb79520f95431@syzkaller.appspotmail.com Reported-by: syzbot+d86c4426a01f60feddc7@syzkaller.appspotmail.com Fixes: bfe4037e722e ("aio: implement IOCB_CMD_POLL") Cc: <stable@vger.kernel.org> # v4.19+ Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>