kernel/linux.git/fs/fuse/virtio_fs.c, branch linux-7.1.y

fuse: add refcount to fuse_dev

2026-04-02T18:43:24+00:00

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

fuse: create fuse_dev on /dev/fuse open instead of mount

2026-04-02T18:43:24+00:00

Allocate struct fuse_dev when opening the device. This means that unlike before, ->private_data is always set to a valid pointer. The use of USE_DEV_SYNC_INIT magic pointer for the private_data is now replaced with a simple bool sync_init member. If sync INIT is not set, I/O on the device returns error before mount. Keep this behavior by checking for the ->fc member. If fud->fc is set, the mount has succeeded. Testing this used READ_ONCE(file->private_data) and smp_mb() to try and provide the necessary semantics. Switch this to smp_store_release() and smp_load_acquire(). Setting fud->fc is protected by fuse_mutex, this is unchanged. Will need this later so the /dev/fuse open file reference is not held during FSCONFIG_CMD_CREATE. Signed-off-by: Miklos Szeredi Reviewed-by: "Darrick J. Wong"

virtiofs: add FUSE protocol validation

2026-02-27T14:00:18+00:00

Add virtio_fs_verify_response() to validate that the server properly follows the FUSE protocol by checking: - Response length is at least sizeof(struct fuse_out_header). - oh.len matches the actual response length. - oh.unique matches the request's unique identifier. On validation failure, set error to -EIO and normalize oh.len to prevent underflow in copy_args_from_argbuf(). Addresses the TODO comment in virtio_fs_request_complete(). Signed-off-by: Yuto Ohnuki Reviewed-by: Stefan Hajnoczi Signed-off-by: Miklos Szeredi

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

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

virtio-fs: fix incorrect check for fsvq->kobj

2025-11-05T13:00:16+00:00

In virtio_fs_add_queues_sysfs(), the code incorrectly checks fs->mqs_kobj after calling kobject_create_and_add(). Change the check to fsvq->kobj (fs->mqs_kobj -> fsvq->kobj) to ensure the per-queue kobject is successfully created. Fixes: 87cbdc396a31 ("virtio_fs: add sysfs entries for queue information") Signed-off-by: Alok Tiwari Link: https://patch.msgid.link/20251027104658.1668537-1-alok.a.tiwari@oracle.com Reviewed-by: Stefan Hajnoczi Signed-off-by: Christian Brauner

Merge tag 'fuse-update-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

2025-10-03T19:48:18+00:00

Pull fuse updates from Miklos Szeredi: - Extend copy_file_range interface to be fully 64bit capable (Miklos) - Add selftest for fusectl (Chen Linxuan) - Move fuse docs into a separate directory (Bagas Sanjaya) - Allow fuse to enter freezable state in some cases (Sergey Senozhatsky) - Clean up writeback accounting after removing tmp page copies (Joanne) - Optimize virtiofs request handling (Li RongQing) - Add synchronous FUSE_INIT support (Miklos) - Allow server to request prune of unused inodes (Miklos) - Fix deadlock with AIO/sync release (Darrick) - Add some prep patches for block/iomap support (Darrick) - Misc fixes and cleanups * tag 'fuse-update-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (26 commits) fuse: move CREATE_TRACE_POINTS to a separate file fuse: move the backing file idr and code into a new source file fuse: enable FUSE_SYNCFS for all fuseblk servers fuse: capture the unique id of fuse commands being sent fuse: fix livelock in synchronous file put from fuseblk workers mm: fix lockdep issues in writeback handling fuse: add prune notification fuse: remove redundant calls to fuse_copy_finish() in fuse_notify() fuse: fix possibly missing fuse_copy_finish() call in fuse_notify() fuse: remove FUSE_NOTIFY_CODE_MAX from fuse: remove fuse_readpages_end() null mapping check fuse: fix references to fuse.rst -> fuse/fuse.rst fuse: allow synchronous FUSE_INIT fuse: zero initialize inode private data fuse: remove unused 'inode' parameter in fuse_passthrough_open virtio_fs: fix the hash table using in virtio_fs_enqueue_req() mm: remove BDI_CAP_WRITEBACK_ACCT fuse: use default writeback accounting virtio_fs: Remove redundant spinlock in virtio_fs_request_complete() fuse: remove unneeded offset assignment when filling write pages ...

fuse: capture the unique id of fuse commands being sent

2025-09-23T09:32:17+00:00

The fuse_request_{send,end} tracepoints capture the value of req->in.h.unique in the trace output. It would be really nice if we could use this to match a request to its response for debugging and latency analysis, but the call to trace_fuse_request_send occurs before the unique id has been set: fuse_request_send: connection 8388608 req 0 opcode 1 (FUSE_LOOKUP) len 107 fuse_request_end: connection 8388608 req 6 len 16 error -2 (Notice that req moves from 0 to 6) Move the callsites to trace_fuse_request_send to after the unique id has been set by introducing a helper to do that for standard fuse_req requests. FUSE_FORGET requests are not covered by this because they appear to be synthesized into the event stream without a fuse_req object and are never replied to. Requests that are aborted without ever having been submitted to the fuse server retain the behavior that only the fuse_request_end tracepoint shows up in the trace record, and with req==0. Signed-off-by: Darrick J. Wong Signed-off-by: Miklos Szeredi

fuse: virtio_fs: fix page fault for DAX page address

2025-09-05T13:56:30+00:00

The commit ced17ee32a99 ("Revert "virtio: reject shm region if length is zero"") exposes the following DAX page fault bug (this fix the failure that getting shm region alway returns false because of zero length): The commit 21aa65bf82a7 ("mm: remove callers of pfn_t functionality") handles the DAX physical page address incorrectly: the removed macro 'phys_to_pfn_t()' should be replaced with 'PHYS_PFN()'. [ 1.390321] BUG: unable to handle page fault for address: ffffd3fb40000008 [ 1.390875] #PF: supervisor read access in kernel mode [ 1.391257] #PF: error_code(0x0000) - not-present page [ 1.391509] PGD 0 P4D 0 [ 1.391626] Oops: Oops: 0000 [#1] SMP NOPTI [ 1.391806] CPU: 6 UID: 1000 PID: 162 Comm: weston Not tainted 6.17.0-rc3-WSL2-STABLE #2 PREEMPT(none) [ 1.392361] RIP: 0010:dax_to_folio+0x14/0x60 [ 1.392653] Code: 52 c9 c3 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 48 c1 ef 05 48 c1 e7 06 48 03 3d 34 b5 31 01 <48> 8b 57 08 48 89 f8 f6 c2 01 75 2b 66 90 c3 cc cc cc cc f7 c7 ff [ 1.393727] RSP: 0000:ffffaf7d04407aa8 EFLAGS: 00010086 [ 1.394003] RAX: 000000a000000000 RBX: ffffaf7d04407bb0 RCX: 0000000000000000 [ 1.394524] RDX: ffffd17b40000008 RSI: 0000000000000083 RDI: ffffd3fb40000000 [ 1.394967] RBP: 0000000000000011 R08: 000000a000000000 R09: 0000000000000000 [ 1.395400] R10: 0000000000001000 R11: ffffaf7d04407c10 R12: 0000000000000000 [ 1.395806] R13: ffffa020557be9c0 R14: 0000014000000001 R15: 0000725970e94000 [ 1.396268] FS: 000072596d6d2ec0(0000) GS:ffffa0222dc59000(0000) knlGS:0000000000000000 [ 1.396715] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1.397100] CR2: ffffd3fb40000008 CR3: 000000011579c005 CR4: 0000000000372ef0 [ 1.397518] Call Trace: [ 1.397663] [ 1.397900] dax_insert_entry+0x13b/0x390 [ 1.398179] dax_fault_iter+0x2a5/0x6c0 [ 1.398443] dax_iomap_pte_fault+0x193/0x3c0 [ 1.398750] __fuse_dax_fault+0x8b/0x270 [ 1.398997] ? vm_mmap_pgoff+0x161/0x210 [ 1.399175] __do_fault+0x30/0x180 [ 1.399360] do_fault+0xc4/0x550 [ 1.399547] __handle_mm_fault+0x8e3/0xf50 [ 1.399731] ? do_syscall_64+0x72/0x1e0 [ 1.399958] handle_mm_fault+0x192/0x2f0 [ 1.400204] do_user_addr_fault+0x20e/0x700 [ 1.400418] exc_page_fault+0x66/0x150 [ 1.400602] asm_exc_page_fault+0x26/0x30 [ 1.400831] RIP: 0033:0x72596d1bf703 [ 1.401076] Code: 31 f6 45 31 e4 48 8d 15 b3 73 00 00 e8 06 03 00 00 8b 83 68 01 00 00 e9 8e fa ff ff 0f 1f 00 48 8b 44 24 08 4c 89 ee 48 89 df 00 21 43 34 12 e8 72 09 00 00 e9 6a fa ff ff 0f 1f 44 00 00 e8 [ 1.402172] RSP: 002b:00007ffc350f6dc0 EFLAGS: 00010202 [ 1.402488] RAX: 0000725970e94000 RBX: 00005b7c642c2560 RCX: 0000725970d359a7 [ 1.402898] RDX: 0000000000000003 RSI: 00007ffc350f6dc0 RDI: 00005b7c642c2560 [ 1.403284] RBP: 00007ffc350f6e90 R08: 000000000000000d R09: 0000000000000000 [ 1.403634] R10: 00007ffc350f6dd8 R11: 0000000000000246 R12: 0000000000000001 [ 1.404078] R13: 00007ffc350f6dc0 R14: 0000725970e29ce0 R15: 0000000000000003 [ 1.404450] [ 1.404570] Modules linked in: [ 1.404821] CR2: ffffd3fb40000008 [ 1.405029] ---[ end trace 0000000000000000 ]--- [ 1.405323] RIP: 0010:dax_to_folio+0x14/0x60 [ 1.405556] Code: 52 c9 c3 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 48 c1 ef 05 48 c1 e7 06 48 03 3d 34 b5 31 01 <48> 8b 57 08 48 89 f8 f6 c2 01 75 2b 66 90 c3 cc cc cc cc f7 c7 ff [ 1.406639] RSP: 0000:ffffaf7d04407aa8 EFLAGS: 00010086 [ 1.406910] RAX: 000000a000000000 RBX: ffffaf7d04407bb0 RCX: 0000000000000000 [ 1.407379] RDX: ffffd17b40000008 RSI: 0000000000000083 RDI: ffffd3fb40000000 [ 1.407800] RBP: 0000000000000011 R08: 000000a000000000 R09: 0000000000000000 [ 1.408246] R10: 0000000000001000 R11: ffffaf7d04407c10 R12: 0000000000000000 [ 1.408666] R13: ffffa020557be9c0 R14: 0000014000000001 R15: 0000725970e94000 [ 1.409170] FS: 000072596d6d2ec0(0000) GS:ffffa0222dc59000(0000) knlGS:0000000000000000 [ 1.409608] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1.409977] CR2: ffffd3fb40000008 CR3: 000000011579c005 CR4: 0000000000372ef0 [ 1.410437] Kernel panic - not syncing: Fatal exception [ 1.410857] Kernel Offset: 0xc000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) Fixes: 21aa65bf82a7 ("mm: remove callers of pfn_t functionality") Signed-off-by: Haiyue Wang Link: https://lore.kernel.org/20250904120339.972-1-haiyuewa@163.com Acked-by: David Hildenbrand Reviewed-by: Miklos Szeredi Signed-off-by: Christian Brauner

virtio_fs: fix the hash table using in virtio_fs_enqueue_req()

2025-08-27T12:29:43+00:00

The original commit be2ff42c5d6e ("fuse: Use hash table to link processing request") converted fuse_pqueue->processing to a hash table, but virtio_fs_enqueue_req() was not updated to use it correctly. So use fuse_pqueue->processing as a hash table, this make the code more coherent Co-developed-by: Fushuai Wang Signed-off-by: Fushuai Wang Signed-off-by: Li RongQing Reviewed-by: Stefan Hajnoczi Signed-off-by: Miklos Szeredi