kernel/linux.git/fs/fuse/file.c, branch v7.1

fuse: fix writeback array overflow when max_pages is one

2026-05-11T12:19:01+00:00

fuse_iomap_writeback_range() appends one folio pointer and one fuse_folio_desc for every dirty range that is merged into the current writeback request. The merge decision checks the byte budget against fc->max_pages and fc->max_write, but it does not check whether the folio and descriptor arrays still have another free slot. This is not sufficient for fuseblk, where the filesystem block size can be smaller than PAGE_SIZE. With writeback cache enabled and max_pages negotiated as one, contiguous sub-page dirty ranges can fit within the byte budget while spanning more than one folio. The next append can then write past the one-slot folios and descs arrays. Split the request when the number of already attached folios has reached fc->max_pages. This keeps the folio/descriptor slot accounting in sync with the send decision. Fixes: ef7e7cbb323f ("fuse: use iomap for writeback") Cc: stable@vger.kernel.org Reviewed-by: Joanne Koong Signed-off-by: Junxi Qian Link: https://patch.msgid.link/20260506122415.205340-1-qjx1298677004@gmail.com Acked-by: Miklos Szeredi Signed-off-by: Christian Brauner

Merge tag 'fuse-update-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

2026-04-16T02:04:21+00:00

Pull fuse update from Miklos Szeredi: - Fix possible hang in virtiofs when cleaning up a DAX inode (Sergio Lopez) - Fix a warning when using large folio as the source of SPLICE_F_MOVE on the fuse device (Bernd) - Fix uninitialized value found by KMSAN (Luis Henriques) - Fix synchronous INIT hang (Miklos) - Fix race between inode initialization and FUSE_NOTIFY_INVAL_INODE (Horst) - Allow fd to be closed after passing fuse device fd to fsconfig(..., "fd", ...) (Miklos) - Support FSCONFIG_SET_FD for "fd" option (Miklos) - Misc fixes and cleanups * tag 'fuse-update-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (21 commits) fuse: support FSCONFIG_SET_FD for "fd" option fuse: clean up device cloning fuse: don't require /dev/fuse fd to be kept open during mount fuse: add refcount to fuse_dev fuse: create fuse_dev on /dev/fuse open instead of mount fuse: check connection state on notification fuse: fuse_dev_ioctl_clone() should wait for device file to be initialized fuse: fix inode initialization race fuse: abort on fatal signal during sync init fuse: fix uninit-value in fuse_dentry_revalidate() fuse: use offset_in_page() for page offset calculations fuse: use DIV_ROUND_UP() for page count calculations fuse: simplify logic in fuse_notify_store() and fuse_retrieve() fuse: validate outarg offset and size in notify store/retrieve fuse: Check for large folio with SPLICE_F_MOVE fuse: quiet down complaints in fuse_conn_limit_write fuse: drop unnecessary argument from fuse_lookup_init() fuse: fix premature writetrhough request for large folio fuse: refactor duplicate queue teardown operation virtiofs: add FUSE protocol validation ...

Merge tag 'vfs-7.1-rc1.integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2026-04-13T17:40:26+00:00

Pull vfs integrity updates from Christian Brauner: "This adds support to generate and verify integrity information (aka T10 PI) in the file system, instead of the automatic below the covers support that is currently used. The implementation is based on refactoring the existing block layer PI code to be reusable for this use case, and then adding relatively small wrappers for the file system use case. These are then used in iomap to implement the semantics, and wired up in XFS with a small amount of glue code. Compared to the baseline this does not change performance for writes, but increases read performance up to 15% for 4k I/O, with the benefit decreasing with larger I/O sizes as even the baseline maxes out the device quickly on my older enterprise SSD" * tag 'vfs-7.1-rc1.integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: xfs: support T10 protection information iomap: support T10 protection information iomap: support ioends for buffered reads iomap: add a bioset pointer to iomap_read_folio_ops ntfs3: remove copy and pasted iomap code iomap: allow file systems to hook into buffered read bio submission iomap: only call into ->submit_read when there is a read_ctx iomap: pass the iomap_iter to ->submit_read iomap: refactor iomap_bio_read_folio_range block: pass a maxlen argument to bio_iov_iter_bounce block: add fs_bio_integrity helpers block: make max_integrity_io_size public block: prepare generation / verification helpers for fs usage block: add a bdev_has_integrity_csum helper block: factor out a bio_integrity_setup_default helper block: factor out a bio_integrity_action helper

writeback: don't block sync for filesystems with no data integrity guarantees

2026-03-20T13:18:56+00:00

Add a SB_I_NO_DATA_INTEGRITY superblock flag for filesystems that cannot guarantee data persistence on sync (eg fuse). For superblocks with this flag set, sync kicks off writeback of dirty inodes but does not wait for the flusher threads to complete the writeback. This replaces the per-inode AS_NO_DATA_INTEGRITY mapping flag added in commit f9a49aa302a0 ("fs/writeback: skip AS_NO_DATA_INTEGRITY mappings in wait_sb_inodes()"). The flag belongs at the superblock level because data integrity is a filesystem-wide property, not a per-inode one. Having this flag at the superblock level also allows us to skip having to iterate every dirty inode in wait_sb_inodes() only to skip each inode individually. Prior to this commit, mappings with no data integrity guarantees skipped waiting on writeback completion but still waited on the flusher threads to finish initiating the writeback. Waiting on the flusher threads is unnecessary. This commit kicks off writeback but does not wait on the flusher threads. This change properly addresses a recent report [1] for a suspend-to-RAM hang seen on fuse-overlayfs that was caused by waiting on the flusher threads to finish: Workqueue: pm_fs_sync pm_fs_sync_work_fn Call Trace: __schedule+0x457/0x1720 schedule+0x27/0xd0 wb_wait_for_completion+0x97/0xe0 sync_inodes_sb+0xf8/0x2e0 __iterate_supers+0xdc/0x160 ksys_sync+0x43/0xb0 pm_fs_sync_work_fn+0x17/0xa0 process_one_work+0x193/0x350 worker_thread+0x1a1/0x310 kthread+0xfc/0x240 ret_from_fork+0x243/0x280 ret_from_fork_asm+0x1a/0x30 On fuse this is problematic because there are paths that may cause the flusher thread to block (eg if systemd freezes the user session cgroups first, which freezes the fuse daemon, before invoking the kernel suspend. The kernel suspend triggers ->write_node() which on fuse issues a synchronous setattr request, which cannot be processed since the daemon is frozen. Or if the daemon is buggy and cannot properly complete writeback, initiating writeback on a dirty folio already under writeback leads to writeback_get_folio() -> folio_prepare_writeback() -> unconditional wait on writeback to finish, which will cause a hang). This commit restores fuse to its prior behavior before tmp folios were removed, where sync was essentially a no-op. [1] https://lore.kernel.org/linux-fsdevel/CAJnrk1a-asuvfrbKXbEwwDSctvemF+6zfhdnuzO65Pt8HsFSRw@mail.gmail.com/T/#m632c4648e9cafc4239299887109ebd880ac6c5c1 Fixes: 0c58a97f919c ("fuse: remove tmp folio for writebacks and internal rb tree") Reported-by: John Cc: stable@vger.kernel.org Signed-off-by: Joanne Koong Link: https://patch.msgid.link/20260320005145.2483161-2-joannelkoong@gmail.com Reviewed-by: Jan Kara Reviewed-by: David Hildenbrand (Arm) Signed-off-by: Christian Brauner

iomap: pass the iomap_iter to ->submit_read

2026-03-10T09:29:03+00:00

This provides additional context for file systems. Rename the fuse instance to match the method name while we're at it. Signed-off-by: Christoph Hellwig Link: https://patch.msgid.link/20260223132021.292832-10-hch@lst.de Tested-by: Anuj Gupta Reviewed-by: "Darrick J. Wong" Signed-off-by: Christian Brauner

fuse: use DIV_ROUND_UP() for page count calculations

2026-03-03T16:43:33+00:00

Use DIV_ROUND_UP() instead of manually computing round-up division calculations. Reviewed-by: Darrick J. Wong Reviewed-by: Horst Birthelmer Signed-off-by: Joanne Koong Signed-off-by: Miklos Szeredi

fuse: fix premature writetrhough request for large folio

2026-03-03T09:05:39+00:00

When large folio is enabled and the initial folio offset exceeds PAGE_SIZE, e.g. the position resides in the second page of a large folio, after the folio copying the offset (in the page) won't be updated to 0 even though the expected range is successfully copied until the end of the folio. In this case fuse_fill_write_pages() exits prematurelly before the request has reached the max_write/max_pages limit. Fix this by eliminating page offset entirely and use folio offset instead. Fixes: d60a6015e1a2 ("fuse: support large folios for writethrough writes") Reviewed-by: Horst Birthelmer Reviewed-by: Joanne Koong Signed-off-by: Jingbo Xu Signed-off-by: Miklos Szeredi

fuse: mark DAX inode releases as blocking

2026-02-27T14:00:17+00:00

Commit 26e5c67deb2e ("fuse: fix livelock in synchronous file put from fuseblk workers") made fputs on closing files always asynchronous. As cleaning up DAX inodes may require issuing a number of synchronous request for releasing the mappings, completing the release request from the worker thread may lead to it hanging like this: [ 21.386751] Workqueue: events virtio_fs_requests_done_work [ 21.386769] Call trace: [ 21.386770] __switch_to+0xe4/0x140 [ 21.386780] __schedule+0x294/0x72c [ 21.386787] schedule+0x24/0x90 [ 21.386794] request_wait_answer+0x184/0x298 [ 21.386799] __fuse_simple_request+0x1f4/0x320 [ 21.386805] fuse_send_removemapping+0x80/0xa0 [ 21.386810] dmap_removemapping_list+0xac/0xfc [ 21.386814] inode_reclaim_dmap_range.constprop.0+0xd0/0x204 [ 21.386820] fuse_dax_inode_cleanup+0x28/0x5c [ 21.386825] fuse_evict_inode+0x120/0x190 [ 21.386834] evict+0x188/0x320 [ 21.386847] iput_final+0xb0/0x20c [ 21.386854] iput+0xa0/0xbc [ 21.386862] fuse_release_end+0x18/0x2c [ 21.386868] fuse_request_end+0x9c/0x2c0 [ 21.386872] virtio_fs_request_complete+0x150/0x384 [ 21.386879] virtio_fs_requests_done_work+0x18c/0x37c [ 21.386885] process_one_work+0x15c/0x2e8 [ 21.386891] worker_thread+0x278/0x480 [ 21.386898] kthread+0xd0/0xdc [ 21.386902] ret_from_fork+0x10/0x20 Here, the virtio-fs worker_thread is waiting on request_wait_answer() for a reply from the virtio-fs server that is already in the virtqueue but will never be processed since it's that same worker thread the one in charge of consuming the elements from the virtqueue. To address this issue, when relesing a DAX inode mark the operation as potentially blocking. Doing this will ensure these release requests are processed on a different worker thread. Signed-off-by: Sergio Lopez Reviewed-by: Darrick J. Wong 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