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path: root/fs/fuse/cuse.c
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2026-08-18cuse: wait for pending RCU callbacks on module exitBaokun Li
Since commit 053fc4f755ad ("fuse: fix UAF in rcu pathwalks"), fuse_conn_put() frees the fuse_conn through call_rcu() rather than synchronously. For cuse, fc->release is cuse_fc_release(), which lives in the cuse module. If the module is removed before the RCU grace period ends, the callback jumps into freed module memory: userspace / module unload | RCU softirq ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ close(/dev/cuse) | cuse_channel_release() | fuse_dev_release() | fuse_conn_put(fch->conn) | call_rcu(delayed_release) ------+---> callback queued | rmmod cuse | cuse_exit() | cuse_channel_destroy() | ... | return | | <module text freed> | | rcu_do_batch() | delayed_release() | fc->release() | -> cuse_fc_release() | ^^^ freed text! The freed module text is unmapped by vfree(), so the jump into the stale callback triggers a page-fault Oops. If the virtual address is subsequently reused, the callback could execute unrelated code (undefined behaviour). Fix this by calling rcu_barrier() in cuse_exit() so that any pending fuse_conn release callback completes before the module is removed. Fixes: 053fc4f755ad ("fuse: fix UAF in rcu pathwalks") Signed-off-by: Baokun Li <libaokun@linux.alibaba.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-07-17fuse: use release/acquire for fch->initializedJoanne Koong
fuse_chan_set_initialized() sets values for the connection state and then sets fch->initialized to true, but lockless readers read fch->initialized and if true, go to read the connection state values, without using any barriers. There are a few instances where this happens (fuse_uring_cmd() before dispatching register / commit-and-fetch cmds, fuse_dev_do_wriite() for handling notify retrieves, etc). To make this as simple as possible, use release/acquire semantics for writing/reading fch->initialized. Add the missing read barriers. This is not marked for stable as these are not realistically reachable on a well-behaved server, and buggy/malicious servers who trigger this path fail benignly rather than crash or deadlock the kernel. Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-06-15fuse: change fud->fc to fud->chanMiklos Szeredi
Store pointer to struct fuse_chan instead of struct fuse_conn in fuse_dev. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-06-15fuse: remove fm arg of args->end callbackMiklos Szeredi
Only used by FUSE_INIT and CUSE_INIT, these can store the relevant pointer in their structs derived from fuse_args. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-06-15fuse: abort related layering cleanupMiklos Szeredi
- rename fuse_abort_conn() to fuse_chan_abort(), pass fuse_chan pointer instead of fuse_conn - pass an abort_with_err argument that tells fuse_dev_(read|write) to return with ECONNABORTED instead of ENODEV - move fc->aborted to fch->abort_with_err - rename fuse_wait_aborted() to fuse_chan_wait_aborted() Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-06-15fuse: move request blocking related members to fuse_chanMiklos Szeredi
Move: - initialized - blocked - blocked_waitq - connected - num_waiting Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-06-15fuse: move fuse_iqueue to fuse_chanMiklos Szeredi
Move the 'fiq' member from fuse_conn to fuse_chan. Move iqueue related structure definitions and function declarations from "fuse_i.h" to "fuse_dev_i.h". Add a fuse_dev_chan_new() helper, that returns a fuse_chan initialized with the fuse_dev_fiq_ops. Add a fuse_chan_release() function, that calls fiq->ops->release(). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-06-15fuse: add struct fuse_chanMiklos Szeredi
The goal is to separate transport layer stuff out from struct fuse_conn, leaving just the filesystem related members. Add a new object referenced from fuse_conn. This patch just implements the allocation and freeing of this object. Following patches will move transport related members from fuse_conn to fuse_chan. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-06-15fuse: fix device node leak in cuse_process_init_reply()Alberto Ruiz
If device_add() succeeds during CUSE initialization but a subsequent step (cdev_alloc() or cdev_add()) fails, the error path calls put_device() without first calling device_del(). This leaks the devtmpfs entry created by device_add(), leaving a stale /dev/<name> node that persists until reboot. Since the cuse_conn is never linked into cuse_conntbl on the failure path, cuse_channel_release() sees cc->dev == NULL and skips device_unregister(), so no other code path cleans up the node. This has several consequences: - The device name is permanently poisoned: any subsequent attempt to create a CUSE device with the same name hits the stale sysfs entry, device_add() fails, and the new device is aborted. - The collision manifests as ENODEV returned to userspace with no dmesg diagnostic, making it very difficult to debug. - The failure is self-perpetuating: once a name is leaked, all future attempts with that name fail identically. Fix this by introducing an err_dev label that calls device_del() to undo device_add() before falling through to err_unlock. The existing err_unlock path from a device_add() failure correctly skips device_del() since the device was never added. Testing instructions can be found at the lore link below. Link: https://lore.kernel.org/all/20260408-wip-cuse-leak-fix-v1-0-1c028d575e97@redhat.com/ Signed-off-by: Alberto Ruiz <aruiz@redhat.com> Fixes: 151060ac1314 ("CUSE: implement CUSE - Character device in Userspace") Cc: stable@vger.kernel.org Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-04-02fuse: add refcount to fuse_devMiklos Szeredi
This will make it possible to grab the fuse_dev and subsequently release the file that it came from. In the above case, fud->fc will be set to FUSE_DEV_FC_DISCONNECTED to indicate that this is no longer a functional device. When trying to assign an fc to such a disconnected fuse_dev, the fc is set to the disconnected state. Use atomic operations xchg() and cmpxchg() to prevent races. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-02-21Convert 'alloc_obj' family to use the new default GFP_KERNEL argumentLinus Torvalds
This was done entirely with mindless brute force, using git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' | xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/' to convert the new alloc_obj() users that had a simple GFP_KERNEL argument to just drop that argument. Note that due to the extreme simplicity of the scripting, any slightly more complex cases spread over multiple lines would not be triggered: they definitely exist, but this covers the vast bulk of the cases, and the resulting diff is also then easier to check automatically. For the same reason the 'flex' versions will be done as a separate conversion. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org>
2025-09-02fuse: allow synchronous FUSE_INITMiklos Szeredi
FUSE_INIT has always been asynchronous with mount. That means that the server processed this request after the mount syscall returned. This means that FUSE_INIT can't supply the root inode's ID, hence it currently has a hardcoded value. There are other limitations such as not being able to perform getxattr during mount, which is needed by selinux. To remove these limitations allow server to process FUSE_INIT while initializing the in-core super block for the fuse filesystem. This can only be done if the server is prepared to handle this, so add FUSE_DEV_IOC_SYNC_INIT ioctl, which a) lets the server know whether this feature is supported, returning ENOTTY othewrwise. b) lets the kernel know to perform a synchronous initialization The implementation is slightly tricky, since fuse_dev/fuse_conn are set up only during super block creation. This is solved by setting the private data of the fuse device file to a special value ((struct fuse_dev *) 1) and waiting for this to be turned into a proper fuse_dev before commecing with operations on the device file. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-11-05fuse: remove pages for requests and exclusively use foliosJoanne Koong
All fuse requests use folios instead of pages for transferring data. Remove pages from the requests and exclusively use folios. No functional changes. [SzM: rename back folio_descs -> descs, etc.] Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-11-05fuse: convert cuse to use foliosJoanne Koong
Convert cuse requests to use a folio instead of a page. No functional changes. Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-04-15cuse: add kernel-doc comments to cuse_process_init_reply()Yang Li
This commit adds kernel-doc style comments with complete parameter descriptions for the function cuse_process_init_reply. Signed-off-by: Yang Li <yang.lee@linux.alibaba.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-02-25fuse: fix UAF in rcu pathwalksAl Viro
->permission(), ->get_link() and ->inode_get_acl() might dereference ->s_fs_info (and, in case of ->permission(), ->s_fs_info->fc->user_ns as well) when called from rcu pathwalk. Freeing ->s_fs_info->fc is rcu-delayed; we need to make freeing ->s_fs_info and dropping ->user_ns rcu-delayed too. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2023-03-17driver core: class: remove module * from class_create()Greg Kroah-Hartman
The module pointer in class_create() never actually did anything, and it shouldn't have been requred to be set as a parameter even if it did something. So just remove it and fix up all callers of the function in the kernel tree at the same time. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Link: https://lore.kernel.org/r/20230313181843.1207845-4-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
2022-11-23fuse: remove the unneeded result variableye xingchen
Return the value fuse_dev_release() directly instead of storing it in another redundant variable. Reported-by: Zeal Robot <zealci@zte.com.cn> Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-14cuse: simplify refcountMiklos Szeredi
Put extra reference early in cuse_channel_open(). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-14cuse: prevent cloneMiklos Szeredi
For cloned connections cuse_channel_release() will be called more than once, resulting in use after free. Prevent device cloning for CUSE, which does not make sense at this point, and highly unlikely to be used in real life. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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>
2020-07-16treewide: Remove uninitialized_var() usageKees Cook
Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. In preparation for removing[2] the[3] macro[4], remove all remaining needless uses with the following script: git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \ xargs perl -pi -e \ 's/\buninitialized_var\(([^\)]+)\)/\1/g; s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;' drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid pathological white-space. No outstanding warnings were found building allmodconfig with GCC 9.3.0 for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64, alpha, and m68k. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5 Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs Signed-off-by: Kees Cook <keescook@chromium.org>
2020-02-06fuse: use true,false for bool variablezhengbin
Fixes coccicheck warning: fs/fuse/readdir.c:335:1-19: WARNING: Assignment of 0/1 to bool variable fs/fuse/file.c:1398:2-19: WARNING: Assignment of 0/1 to bool variable fs/fuse/file.c:1400:2-20: WARNING: Assignment of 0/1 to bool variable fs/fuse/cuse.c:454:1-20: WARNING: Assignment of 0/1 to bool variable fs/fuse/cuse.c:455:1-19: WARNING: Assignment of 0/1 to bool variable fs/fuse/inode.c:497:2-17: WARNING: Assignment of 0/1 to bool variable fs/fuse/inode.c:504:2-23: WARNING: Assignment of 0/1 to bool variable fs/fuse/inode.c:511:2-22: WARNING: Assignment of 0/1 to bool variable fs/fuse/inode.c:518:2-23: WARNING: Assignment of 0/1 to bool variable fs/fuse/inode.c:522:2-26: WARNING: Assignment of 0/1 to bool variable fs/fuse/inode.c:526:2-18: WARNING: Assignment of 0/1 to bool variable fs/fuse/inode.c:1000:1-20: WARNING: Assignment of 0/1 to bool variable Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: zhengbin <zhengbin13@huawei.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-24fuse: fix memleak in cuse_channel_openzhengbin
If cuse_send_init fails, need to fuse_conn_put cc->fc. cuse_channel_open->fuse_conn_init->refcount_set(&fc->count, 1) ->fuse_dev_alloc->fuse_conn_get ->fuse_dev_free->fuse_conn_put Fixes: cc080e9e9be1 ("fuse: introduce per-instance fuse_dev structure") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: zhengbin <zhengbin13@huawei.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>
2019-09-10cuse: convert init to simple apiMiklos Szeredi
This is a straightforward conversion. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-02cuse: fix broken releaseMiklos Szeredi
The inode parameter in cuse_release() is likely *not* a fuse inode. It's a small wonder it didn't blow up until now. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428Thomas Gleixner
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>
2019-04-24fuse: convert printk -> pr_*Kirill Smelkov
Functions, like pr_err, are a more modern variant of printing compared to printk. They could be used to denoise sources by using needed level in the print function name, and by automatically inserting per-driver / function / ... print prefix as defined by pr_fmt macro. pr_* are also said to be used in Documentation/process/coding-style.rst and more recent code - for example overlayfs - uses them instead of printk. Convert CUSE and FUSE to use the new pr_* functions. CUSE output stays completely unchanged, while FUSE output is amended a bit for "trying to steal weird page" warning - the second line now comes also with "fuse:" prefix. I hope it is ok. Suggested-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: Kirill Smelkov <kirr@nexedi.com> Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-02-13fuse: clean up abortedMiklos Szeredi
The only caller that needs fc->aborted set is fuse_conn_abort_write(). Setting fc->aborted is now racy (fuse_abort_conn() may already be in progress or finished) but there's no reason to care. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-02-13fuse: Add fuse_inode argument to fuse_prepare_release()Kirill Tkhai
Here is preparation for next patches, which introduce new fi->lock for protection of ff->write_entry linked into fi->write_files. This patch just passes new argument to the function. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-03-20fuse: Support fuse filesystems outside of init_user_nsEric W. Biederman
In order to support mounts from namespaces other than init_user_ns, fuse must translate uids and gids to/from the userns of the process servicing requests on /dev/fuse. This patch does that, with a couple of restrictions on the namespace: - The userns for the fuse connection is fixed to the namespace from which /dev/fuse is opened. - The namespace must be the same as s_user_ns. These restrictions simplify the implementation by avoiding the need to pass around userns references and by allowing fuse to rely on the checks in setattr_prepare for ownership changes. Either restriction could be relaxed in the future if needed. For cuse the userns used is the opener of /dev/cuse. Semantically the cuse support does not appear safe for unprivileged users. Practically the permissions on /dev/cuse only make it accessible to the global root user. If something slips through the cracks in a user namespace the only users who will be able to use the cuse device are those users mapped into the user namespace. Translation in the posix acl is updated to use the uuser namespace of the filesystem. Avoiding cases which might bypass this translation is handled in a following change. This change is stronlgy based on a similar change from Seth Forshee and Dongsu Park. Cc: Seth Forshee <seth.forshee@canonical.com> Cc: Dongsu Park <dongsu@kinvolk.io> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-03-20fuse: return -ECONNABORTED on /dev/fuse read after abortSzymon Lukasz
Currently the userspace has no way of knowing whether the fuse connection ended because of umount or abort via sysfs. It makes it hard for filesystems to free the mountpoint after abort without worrying about removing some new mount. The patch fixes it by returning different errors when userspace reads from /dev/fuse (-ENODEV for umount and -ECONNABORTED for abort). Add a new capability flag FUSE_ABORT_ERROR. If set and the connection is gone because of sysfs abort, reading from the device will return -ECONNABORTED. Signed-off-by: Szymon Lukasz <noh4hss@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-09-12fuse: honor iocb sync flags on writeMiklos Szeredi
If the IOCB_DSYNC flag is set a sync is not being performed by fuse_file_write_iter. Honor IOCB_DSYNC/IOCB_SYNC by setting O_DYSNC/O_SYNC respectively in the flags filed of the write request. We don't need to sync data or metadata, since fuse_perform_write() does write-through and the filesystem is responsible for updating file times. Original patch by Vitaly Zolotusky. Reported-by: Nate Clark <nate@neworld.us> Cc: Vitaly Zolotusky <vitaly@unitc.com>. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-03-14fuse: Add reference counting for fuse_io_privSeth Forshee
The 'reqs' member of fuse_io_priv serves two purposes. First is to track the number of oustanding async requests to the server and to signal that the io request is completed. The second is to be a reference count on the structure to know when it can be freed. For sync io requests these purposes can be at odds. fuse_direct_IO() wants to block until the request is done, and since the signal is sent when 'reqs' reaches 0 it cannot keep a reference to the object. Yet it needs to use the object after the userspace server has completed processing requests. This leads to some handshaking and special casing that it needlessly complicated and responsible for at least one race condition. It's much cleaner and safer to maintain a separate reference count for the object lifecycle and to let 'reqs' just be a count of outstanding requests to the userspace server. Then we can know for sure when it is safe to free the object without any handshaking or special cases. The catch here is that most of the time these objects are stack allocated and should not be freed. Initializing these objects with a single reference that is never released prevents accidental attempts to free the objects. Fixes: 9d5722b7777e ("fuse: handle synchronous iocbs internally") Cc: stable@vger.kernel.org # v4.1+ Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2015-11-10cuse: fix memory leakMiklos Szeredi
The problem is that fuse_dev_alloc() acquires an extra reference to cc.fc, and the original ref count is never dropped. Reported-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Fixes: cc080e9e9be1 ("fuse: introduce per-instance fuse_dev structure") Cc: <stable@vger.kernel.org> # v4.2+
2015-07-01fuse: introduce per-instance fuse_dev structureMiklos Szeredi
Allow fuse device clones to refer to be distinguished. This patch just adds the infrastructure by associating a separate "struct fuse_dev" with each clone. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Reviewed-by: Ashish Samant <ashish.samant@oracle.com>
2015-07-01fuse: duplicate ->connected in iqueueMiklos Szeredi
This will allow checking ->connected just with the input queue lock. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Reviewed-by: Ashish Samant <ashish.samant@oracle.com>
2015-04-11make new_sync_{read,write}() staticAl Viro
All places outside of core VFS that checked ->read and ->write for being NULL or called the methods directly are gone now, so NULL {read,write} with non-NULL {read,write}_iter will do the right thing in all cases. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11cuse: switch to iov_iterAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-03-25fs: move struct kiocb to fs.hChristoph Hellwig
struct kiocb now is a generic I/O container, so move it to fs.h. Also do a #include diet for aio.h while we're at it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-12fuse: flush requests on umountMiklos Szeredi
Use fuse_abort_conn() instead of fuse_conn_kill() in fuse_put_super(). This flushes and aborts requests still on any queues. But since we've already reset fc->connected, those requests would not be useful anyway and would be flushed when the fuse device is closed. Next patches will rely on requests being flushed before the superblock is destroyed. Use fuse_abort_conn() in cuse_process_init_reply() too, since it makes no difference there, and we can get rid of fuse_conn_kill(). Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-05-06fuse: pull iov_iter initializations upAl Viro
... to fuse_direct_{read,write}(). ->direct_IO() path uses the iov_iter passed by the caller instead. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-06Merge tag 'modules-next-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module updates from Rusty Russell: "Nothing major: the stricter permissions checking for sysfs broke a staging driver; fix included. Greg KH said he'd take the patch but hadn't as the merge window opened, so it's included here to avoid breaking build" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: staging: fix up speakup kobject mode Use 'E' instead of 'X' for unsigned module taint flag. VERIFY_OCTAL_PERMISSIONS: stricter checking for sysfs perms. kallsyms: fix percpu vars on x86-64 with relocation. kallsyms: generalize address range checking module: LLVMLinux: Remove unused function warning from __param_check macro Fix: module signature vs tracepoints: add new TAINT_UNSIGNED_MODULE module: remove MODULE_GENERIC_TABLE module: allow multiple calls to MODULE_DEVICE_TABLE() per module module: use pr_cont
2014-04-02fuse: Fix O_DIRECT operations vs cached writeback misorderPavel Emelyanov
The problem is: 1. write cached data to a file 2. read directly from the same file (via another fd) The 2nd operation may read stale data, i.e. the one that was in a file before the 1st op. Problem is in how fuse manages writeback. When direct op occurs the core kernel code calls filemap_write_and_wait to flush all the cached ops in flight. But fuse acks the writeback right after the ->writepages callback exits w/o waiting for the real write to happen. Thus the subsequent direct op proceeds while the real writeback is still in flight. This is a problem for backends that reorder operation. Fix this by making the fuse direct IO callback explicitly wait on the in-flight writeback to finish. Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-03-24VERIFY_OCTAL_PERMISSIONS: stricter checking for sysfs perms.Rusty Russell
Summary of http://lkml.org/lkml/2014/3/14/363 : Ted: module_param(queue_depth, int, 444) Joe: 0444! Rusty: User perms >= group perms >= other perms? Joe: CLASS_ATTR, DEVICE_ATTR, SENSOR_ATTR and SENSOR_ATTR_2? Side effect of stricter permissions means removing the unnecessary S_IFREG from several callers. Note that the BUILD_BUG_ON_ZERO((perm) & 2) test was removed: a fair number of drivers fail this test, so that will be the debate for a future patch. Suggested-by: Joe Perches <joe@perches.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> for drivers/pci/slot.c Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-11-13Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "All kinds of stuff this time around; some more notable parts: - RCU'd vfsmounts handling - new primitives for coredump handling - files_lock is gone - Bruce's delegations handling series - exportfs fixes plus misc stuff all over the place" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (101 commits) ecryptfs: ->f_op is never NULL locks: break delegations on any attribute modification locks: break delegations on link locks: break delegations on rename locks: helper functions for delegation breaking locks: break delegations on unlink namei: minor vfs_unlink cleanup locks: implement delegations locks: introduce new FL_DELEG lock flag vfs: take i_mutex on renamed file vfs: rename I_MUTEX_QUOTA now that it's not used for quotas vfs: don't use PARENT/CHILD lock classes for non-directories vfs: pull ext4's double-i_mutex-locking into common code exportfs: fix quadratic behavior in filehandle lookup exportfs: better variable name exportfs: move most of reconnect_path to helper function exportfs: eliminate unused "noprogress" counter exportfs: stop retrying once we race with rename/remove exportfs: clear DISCONNECTED on all parents sooner exportfs: more detailed comment for path_reconnect ...