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2025-01-27fuse: enable fuse-over-io-uringBernd Schubert-0/+3
All required parts are handled now, fuse-io-uring can be enabled. Signed-off-by: Bernd Schubert <bschubert@ddn.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # io_uring Reviewed-by: Luis Henriques <luis@igalia.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2025-01-27fuse: block request allocation until io-uring init is completeBernd Schubert-1/+2
Avoid races and block request allocation until io-uring queues are ready. This is a especially important for background requests, as bg request completion might cause lock order inversion of the typical queue->lock and then fc->bg_lock fuse_request_end spin_lock(&fc->bg_lock); flush_bg_queue fuse_send_one fuse_uring_queue_fuse_req spin_lock(&queue->lock); Signed-off-by: Bernd Schubert <bernd@bsbernd.com> Reviewed-by: Luis Henriques <luis@igalia.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2025-01-27fuse: Allow to queue bg requests through io-uringBernd Schubert-1/+25
This prepares queueing and sending background requests through io-uring. Signed-off-by: Bernd Schubert <bschubert@ddn.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # io_uring Reviewed-by: Luis Henriques <luis@igalia.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2025-01-27fuse: {io-uring} Make fuse_dev_queue_{interrupt,forget} non-staticBernd Schubert-2/+3
These functions are also needed by fuse-over-io-uring. Signed-off-by: Bernd Schubert <bschubert@ddn.com> Reviewed-by: Luis Henriques <luis@igalia.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2025-01-27fuse: {io-uring} Handle teardown of ring entriesBernd Schubert-0/+9
On teardown struct file_operations::uring_cmd requests need to be completed by calling io_uring_cmd_done(). Not completing all ring entries would result in busy io-uring tasks giving warning messages in intervals and unreleased struct file. Additionally the fuse connection and with that the ring can only get released when all io-uring commands are completed. Completion is done with ring entries that are a) in waiting state for new fuse requests - io_uring_cmd_done is needed b) already in userspace - io_uring_cmd_done through teardown is not needed, the request can just get released. If fuse server is still active and commits such a ring entry, fuse_uring_cmd() already checks if the connection is active and then complete the io-uring itself with -ENOTCONN. I.e. special handling is not needed. This scheme is basically represented by the ring entry state FRRS_WAIT and FRRS_USERSPACE. Entries in state: - FRRS_INIT: No action needed, do not contribute to ring->queue_refs yet - All other states: Are currently processed by other tasks, async teardown is needed and it has to wait for the two states above. It could be also solved without an async teardown task, but would require additional if conditions in hot code paths. Also in my personal opinion the code looks cleaner with async teardown. Signed-off-by: Bernd Schubert <bschubert@ddn.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # io_uring Reviewed-by: Luis Henriques <luis@igalia.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2025-01-24fuse: {io-uring} Make hash-list req unique finding functions non-staticBernd Schubert-3/+3
fuse-over-io-uring uses existing functions to find requests based on their unique id - make these functions non-static. Signed-off-by: Bernd Schubert <bschubert@ddn.com> Reviewed-by: Joanne Koong <joannelkoong@gmail.com> Reviewed-by: Luis Henriques <luis@igalia.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2025-01-24fuse: Add fuse-io-uring handling into fuse_copyBernd Schubert-1/+11
Add special fuse-io-uring into the fuse argument copy handler. Signed-off-by: Bernd Schubert <bschubert@ddn.com> Reviewed-by: Joanne Koong <joannelkoong@gmail.com> Reviewed-by: Luis Henriques <luis@igalia.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2025-01-24fuse: Make fuse_copy non staticBernd Schubert-22/+8
Move 'struct fuse_copy_state' and fuse_copy_* functions to fuse_dev_i.h to make it available for fuse-io-uring. 'copy_out_args()' is renamed to 'fuse_copy_out_args'. Signed-off-by: Bernd Schubert <bschubert@ddn.com> Reviewed-by: Joanne Koong <joannelkoong@gmail.com> Reviewed-by: Luis Henriques <luis@igalia.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2025-01-24fuse: make args->in_args[0] to be always the headerBernd Schubert-4/+5
This change sets up FUSE operations to always have headers in args.in_args[0], even for opcodes without an actual header. This step prepares for a clean separation of payload from headers, initially it is used by fuse-over-io-uring. For opcodes without a header, we use a zero-sized struct as a placeholder. This approach: - Keeps things consistent across all FUSE operations - Will help with payload alignment later - Avoids future issues when header sizes change Op codes that already have an op code specific header do not need modification. Op codes that have neither payload nor op code headers are not modified either (FUSE_READLINK and FUSE_DESTROY). FUSE_BATCH_FORGET already has the header in the right place, but is not using fuse_copy_args - as -over-uring is currently not handling forgets it does not matter for now, but header separation will later need special attention for that op code. Correct the struct fuse_args->in_args array max size. Signed-off-by: Bernd Schubert <bschubert@ddn.com> Reviewed-by: Joanne Koong <joannelkoong@gmail.com> Reviewed-by: Luis Henriques <luis@igalia.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2025-01-24fuse: Move request bitsBernd Schubert-4/+0
These are needed by fuse-over-io-uring. Signed-off-by: Bernd Schubert <bschubert@ddn.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Joanne Koong <joannelkoong@gmail.com> Reviewed-by: Luis Henriques <luis@igalia.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2025-01-24fuse: Move fuse_get_dev to header fileBernd Schubert-9/+0
Another preparation patch, as this function will be needed by fuse/dev.c and fuse/dev_uring.c. Signed-off-by: Bernd Schubert <bschubert@ddn.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Joanne Koong <joannelkoong@gmail.com> Reviewed-by: Luis Henriques <luis@igalia.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2025-01-24fuse: rename to fuse_dev_end_requests and make non-staticBernd Schubert-6/+5
This function is needed by fuse_uring.c to clean ring queues, so make it non static. Especially in non-static mode the function name 'end_requests' should be prefixed with fuse_ Signed-off-by: Bernd Schubert <bschubert@ddn.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Joanne Koong <joannelkoong@gmail.com> Reviewed-by: Luis Henriques <luis@igalia.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-11-26Merge tag 'fuse-update-6.13' of ↵Linus Torvalds-27/+39
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse Pull fuse updates from Miklos Szeredi: - Add page -> folio conversions (Joanne Koong, Josef Bacik) - Allow max size of fuse requests to be configurable with a sysctl (Joanne Koong) - Allow FOPEN_DIRECT_IO to take advantage of async code path (yangyun) - Fix large kernel reads (like a module load) in virtio_fs (Hou Tao) - Fix attribute inconsistency in case readdirplus (and plain lookup in corner cases) is racing with inode eviction (Zhang Tianci) - Fix a WARN_ON triggered by virtio_fs (Asahi Lina) * tag 'fuse-update-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (30 commits) virtiofs: dax: remove ->writepages() callback fuse: check attributes staleness on fuse_iget() fuse: remove pages for requests and exclusively use folios fuse: convert direct io to use folios mm/writeback: add folio_mark_dirty_lock() fuse: convert writebacks to use folios fuse: convert retrieves to use folios fuse: convert ioctls to use folios fuse: convert writes (non-writeback) to use folios fuse: convert reads to use folios fuse: convert readdir to use folios fuse: convert readlink to use folios fuse: convert cuse to use folios fuse: add support in virtio for requests using folios fuse: support folios in struct fuse_args_pages and fuse_copy_pages() fuse: convert fuse_notify_store to use folios fuse: convert fuse_retrieve to use folios fuse: use the folio based vmstat helpers fuse: convert fuse_writepage_need_send to take a folio fuse: convert fuse_do_readpage to use folios ...
2024-11-05fuse: remove pages for requests and exclusively use foliosJoanne Koong-36/+21
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 retrieves to use foliosJoanne Koong-10/+12
Convert retrieve requests to use folios instead of pages. 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>
2024-11-05fuse: support folios in struct fuse_args_pages and fuse_copy_pages()Joanne Koong-8/+32
This adds support in struct fuse_args_pages and fuse_copy_pages() for using folios instead of pages for transferring data. Both folios and pages must be supported right now in struct fuse_args_pages and fuse_copy_pages() until all request types have been converted to use folios. Once all have been converted, then struct fuse_args_pages and fuse_copy_pages() will only support folios. Right now in fuse, all folios are one page (large folios are not yet supported). As such, copying folio->page is sufficient for copying the entire folio in fuse_copy_pages(). 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>
2024-11-03fdget(), more trivial conversionsAl Viro-4/+2
all failure exits prior to fdget() leave the scope, all matching fdput() are immediately followed by leaving the scope. [xfs_ioc_commit_range() chunk moved here as well] Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-10-25fuse: convert fuse_notify_store to use foliosJosef Bacik-11/+12
This function creates pages in an inode and copies data into them, update the function to use a folio instead of a page, and use the appropriate folio helpers. [SzM: use filemap_grab_folio()] [Hau Tao: The third argument of folio_zero_range() should be the length to be zeroed, not the total length. Fix it by using folio_zero_segment() instead in fuse_notify_store()] Reviewed-by: Joanne Koong <joannelkoong@gmail.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-10-25fuse: convert fuse_retrieve to use foliosJosef Bacik-4/+4
We're just looking for pages in a mapping, use a folio and the folio lookup function directly instead of using the page helper. Reviewed-by: Joanne Koong <joannelkoong@gmail.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-09-27[tree-wide] finally take no_llseek outAl Viro-1/+0
no_llseek had been defined to NULL two years ago, in commit 868941b14441 ("fs: remove no_llseek") To quote that commit, At -rc1 we'll need do a mechanical removal of no_llseek - git grep -l -w no_llseek | grep -v porting.rst | while read i; do sed -i '/\<no_llseek\>/d' $i done would do it. Unfortunately, that hadn't been done. Linus, could you do that now, so that we could finally put that thing to rest? All instances are of the form .llseek = no_llseek, so it's obviously safe. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-09-24Merge tag 'fuse-update-6.12' of ↵Linus Torvalds-83/+131
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse Pull fuse updates from Miklos Szeredi: - Add support for idmapped fuse mounts (Alexander Mikhalitsyn) - Add optimization when checking for writeback (yangyun) - Add tracepoints (Josef Bacik) - Clean up writeback code (Joanne Koong) - Clean up request queuing (me) - Misc fixes * tag 'fuse-update-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (32 commits) fuse: use exclusive lock when FUSE_I_CACHE_IO_MODE is set fuse: clear FR_PENDING if abort is detected when sending request fs/fuse: convert to use invalid_mnt_idmap fs/mnt_idmapping: introduce an invalid_mnt_idmap fs/fuse: introduce and use fuse_simple_idmap_request() helper fs/fuse: fix null-ptr-deref when checking SB_I_NOIDMAP flag fuse: allow O_PATH fd for FUSE_DEV_IOC_BACKING_OPEN virtio_fs: allow idmapped mounts fuse: allow idmapped mounts fuse: warn if fuse_access is called when idmapped mounts are allowed fuse: handle idmappings properly in ->write_iter() fuse: support idmapped ->rename op fuse: support idmapped ->set_acl fuse: drop idmap argument from __fuse_get_acl fuse: support idmapped ->setattr op fuse: support idmapped ->permission inode op fuse: support idmapped getattr inode op fuse: support idmap for mkdir/mknod/symlink/create/tmpfile fuse: support idmapped FUSE_EXT_GROUPS fuse: add an idmap argument to fuse_simple_request ...
2024-09-24fuse: clear FR_PENDING if abort is detected when sending requestMiklos Szeredi-0/+1
The (!fiq->connected) check was moved into the queuing method resulting in the following: Fixes: 5de8acb41c86 ("fuse: cleanup request queuing towards virtiofs") Reported-by: Lai, Yi <yi1.lai@linux.intel.com> Closes: https://lore.kernel.org/all/ZvFEAM6JfrBKsOU0@ly-workstation/ Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-09-23Merge tag 'pull-stable-struct_fd' of ↵Linus Torvalds-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull 'struct fd' updates from Al Viro: "Just the 'struct fd' layout change, with conversion to accessor helpers" * tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: add struct fd constructors, get rid of __to_fd() struct fd: representation change introduce fd_file(), convert all accessors to it.
2024-09-23fs/fuse: convert to use invalid_mnt_idmapAlexander Mikhalitsyn-24/+23
We should convert fs/fuse code to use a newly introduced invalid_mnt_idmap instead of passing a NULL as idmap pointer. Suggested-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-09-23fs/fuse: introduce and use fuse_simple_idmap_request() helperAlexander Mikhalitsyn-3/+3
Let's convert all existing callers properly. No functional changes intended. Suggested-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-09-23fs/fuse: fix null-ptr-deref when checking SB_I_NOIDMAP flagAlexander Mikhalitsyn-2/+2
It was reported [1] that on linux-next/fs-next the following crash is reproducible: [ 42.659136] Oops: general protection fault, probably for non-canonical address 0xdffffc000000000b: 0000 [#1] PREEMPT SMP KASAN NOPTI [ 42.660501] fbcon: Taking over console [ 42.660930] KASAN: null-ptr-deref in range [0x0000000000000058-0x000000000000005f] [ 42.661752] CPU: 1 UID: 0 PID: 1589 Comm: dtprobed Not tainted 6.11.0-rc6+ #1 [ 42.662565] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.6.6 08/22/2023 [ 42.663472] RIP: 0010:fuse_get_req+0x36b/0x990 [fuse] [ 42.664046] Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 8c 05 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 6d 08 48 8d 7d 58 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 4d 05 00 00 f6 45 59 20 0f 85 06 03 00 00 48 83 [ 42.666945] RSP: 0018:ffffc900009a7730 EFLAGS: 00010212 [ 42.668837] RAX: dffffc0000000000 RBX: 1ffff92000134eed RCX: ffffffffc20dec9a [ 42.670122] RDX: 000000000000000b RSI: 0000000000000008 RDI: 0000000000000058 [ 42.672154] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1022110172 [ 42.672160] R10: ffff888110880b97 R11: ffffc900009a737a R12: 0000000000000001 [ 42.672179] R13: ffff888110880b60 R14: ffff888110880b90 R15: ffff888169973840 [ 42.672186] FS: 00007f28cd21d7c0(0000) GS:ffff8883ef280000(0000) knlGS:0000000000000000 [ 42.672191] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 42.[ CR02: ;32m00007f3237366208 CR3: 0 OK 79e001 CR4: 0000000000770ef0 [ 42.672214] PKRU: 55555554 [ 42.672218] Call Trace: [ 42.672223] <TASK> [ 42.672226] ? die_addr+0x41/0xa0 [ 42.672238] ? exc_general_protection+0x14c/0x230 [ 42.672250] ? asm_exc_general_protection+0x26/0x30 [ 42.672260] ? fuse_get_req+0x77a/0x990 [fuse] [ 42.672281] ? fuse_get_req+0x36b/0x990 [fuse] [ 42.672300] ? kasan_unpoison+0x27/0x60 [ 42.672310] ? __pfx_fuse_get_req+0x10/0x10 [fuse] [ 42.672327] ? srso_alias_return_thunk+0x5/0xfbef5 [ 42.672333] ? alloc_pages_mpol_noprof+0x195/0x440 [ 42.672340] ? srso_alias_return_thunk+0x5/0xfbef5 [ 42.672345] ? kasan_unpoison+0x27/0x60 [ 42.672350] ? srso_alias_return_thunk+0x5/0xfbef5 [ 42.672355] ? __kasan_slab_alloc+0x4d/0x90 [ 42.672362] ? srso_alias_return_thunk+0x5/0xfbef5 [ 42.672367] ? __kmalloc_cache_noprof+0x134/0x350 [ 42.672376] fuse_simple_background+0xe7/0x180 [fuse] [ 42.672406] cuse_channel_open+0x540/0x710 [cuse] [ 42.672415] misc_open+0x2a7/0x3a0 [ 42.672424] chrdev_open+0x1ef/0x5f0 [ 42.672432] ? __pfx_chrdev_open+0x10/0x10 [ 42.672439] ? srso_alias_return_thunk+0x5/0xfbef5 [ 42.672443] ? security_file_open+0x3bb/0x720 [ 42.672451] do_dentry_open+0x43d/0x1200 [ 42.672459] ? __pfx_chrdev_open+0x10/0x10 [ 42.672468] vfs_open+0x79/0x340 [ 42.672475] ? srso_alias_return_thunk+0x5/0xfbef5 [ 42.672482] do_open+0x68c/0x11e0 [ 42.672489] ? srso_alias_return_thunk+0x5/0xfbef5 [ 42.672495] ? __pfx_do_open+0x10/0x10 [ 42.672501] ? srso_alias_return_thunk+0x5/0xfbef5 [ 42.672506] ? open_last_lookups+0x2a2/0x1370 [ 42.672515] path_openat+0x24f/0x640 [ 42.672522] ? __pfx_path_openat+0x10/0x10 [ 42.723972] ? stack_depot_save_flags+0x45/0x4b0 [ 42.724787] ? __fput+0x43c/0xa70 [ 42.725100] do_filp_open+0x1b3/0x3e0 [ 42.725710] ? poison_slab_object+0x10d/0x190 [ 42.726145] ? __kasan_slab_free+0x33/0x50 [ 42.726570] ? __pfx_do_filp_open+0x10/0x10 [ 42.726981] ? do_syscall_64+0x64/0x170 [ 42.727418] ? entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 42.728018] ? srso_alias_return_thunk+0x5/0xfbef5 [ 42.728505] ? do_raw_spin_lock+0x131/0x270 [ 42.728922] ? __pfx_do_raw_spin_lock+0x10/0x10 [ 42.729494] ? do_raw_spin_unlock+0x14c/0x1f0 [ 42.729992] ? srso_alias_return_thunk+0x5/0xfbef5 [ 42.730889] ? srso_alias_return_thunk+0x5/0xfbef5 [ 42.732178] ? alloc_fd+0x176/0x5e0 [ 42.732585] do_sys_openat2+0x122/0x160 [ 42.732929] ? __pfx_do_sys_openat2+0x10/0x10 [ 42.733448] ? srso_alias_return_thunk+0x5/0xfbef5 [ 42.734013] ? __pfx_map_id_up+0x10/0x10 [ 42.734482] ? srso_alias_return_thunk+0x5/0xfbef5 [ 42.735529] ? __memcg_slab_free_hook+0x292/0x500 [ 42.736131] __x64_sys_openat+0x123/0x1e0 [ 42.736526] ? __pfx___x64_sys_openat+0x10/0x10 [ 42.737369] ? __x64_sys_close+0x7c/0xd0 [ 42.737717] ? srso_alias_return_thunk+0x5/0xfbef5 [ 42.738192] ? syscall_trace_enter+0x11e/0x1b0 [ 42.738739] do_syscall_64+0x64/0x170 [ 42.739113] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 42.739638] RIP: 0033:0x7f28cd13e87b [ 42.740038] Code: 25 00 00 41 00 3d 00 00 41 00 74 4b 64 8b 04 25 18 00 00 00 85 c0 75 67 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 91 00 00 00 48 8b 54 24 28 64 48 2b 14 25 [ 42.741943] RSP: 002b:00007ffc992546c0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 [ 42.742951] RAX: ffffffffffffffda RBX: 00007f28cd44f1ee RCX: 00007f28cd13e87b [ 42.743660] RDX: 0000000000000002 RSI: 00007f28cd44f2fa RDI: 00000000ffffff9c [ 42.744518] RBP: 00007f28cd44f2fa R08: 0000000000000000 R09: 0000000000000001 [ 42.745211] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 [ 42.745920] R13: 00007f28cd44f2fa R14: 0000000000000000 R15: 0000000000000003 [ 42.746708] </TASK> [ 42.746937] Modules linked in: cuse vfat fat ext4 mbcache jbd2 intel_rapl_msr intel_rapl_common kvm_amd ccp bochs drm_vram_helper kvm drm_ttm_helper ttm pcspkr i2c_piix4 drm_kms_helper i2c_smbus pvpanic_mmio pvpanic joydev sch_fq_codel drm fuse xfs nvme_tcp nvme_fabrics nvme_core sd_mod sg virtio_net net_failover virtio_scsi failover crct10dif_pclmul crc32_pclmul ata_generic pata_acpi ata_piix ghash_clmulni_intel virtio_pci sha512_ssse3 virtio_pci_legacy_dev sha256_ssse3 virtio_pci_modern_dev sha1_ssse3 libata serio_raw dm_multipath btrfs blake2b_generic xor zstd_compress raid6_pq sunrpc dm_mirror dm_region_hash dm_log dm_mod be2iscsi bnx2i cnic uio cxgb4i cxgb4 tls cxgb3i cxgb3 mdio libcxgbi libcxgb qla4xxx iscsi_boot_sysfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi qemu_fw_cfg aesni_intel crypto_simd cryptd [ 42.754333] ---[ end trace 0000000000000000 ]--- [ 42.756899] RIP: 0010:fuse_get_req+0x36b/0x990 [fuse] [ 42.757851] Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 8c 05 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 6d 08 48 8d 7d 58 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 4d 05 00 00 f6 45 59 20 0f 85 06 03 00 00 48 83 [ 42.760334] RSP: 0018:ffffc900009a7730 EFLAGS: 00010212 [ 42.760940] RAX: dffffc0000000000 RBX: 1ffff92000134eed RCX: ffffffffc20dec9a [ 42.761697] RDX: 000000000000000b RSI: 0000000000000008 RDI: 0000000000000058 [ 42.763009] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1022110172 [ 42.763920] R10: ffff888110880b97 R11: ffffc900009a737a R12: 0000000000000001 [ 42.764839] R13: ffff888110880b60 R14: ffff888110880b90 R15: ffff888169973840 [ 42.765716] FS: 00007f28cd21d7c0(0000) GS:ffff8883ef280000(0000) knlGS:0000000000000000 [ 42.766890] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 42.767828] CR2: 00007f3237366208 CR3: 000000012c79e001 CR4: 0000000000770ef0 [ 42.768730] PKRU: 55555554 [ 42.769022] Kernel panic - not syncing: Fatal exception [ 42.770758] Kernel Offset: 0x7200000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 42.771947] ---[ end Kernel panic - not syncing: Fatal exception ]--- It's obviously CUSE related callstack. For CUSE case, we don't have superblock and our checks for SB_I_NOIDMAP flag does not make any sense. Let's handle this case gracefully. Fixes: aa16880d9f13 ("fuse: add basic infrastructure to support idmappings") Link: https://lore.kernel.org/linux-next/87v7z586py.fsf@debian-BULLSEYE-live-builder-AMD64/ [1] Reported-by: Chandan Babu R <chandanbabu@kernel.org> Reported-by: syzbot+20c7e20cc8f5296dca12@syzkaller.appspotmail.com Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-09-04fuse: add an idmap argument to fuse_simple_requestAlexander Mikhalitsyn-2/+4
If idmap == NULL *and* filesystem daemon declared idmapped mounts support, then uid/gid values in a fuse header will be -1. No functional changes intended. Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-09-04fuse: add basic infrastructure to support idmappingsAlexander Mikhalitsyn-12/+38
Add some preparational changes in fuse_get_req/fuse_force_creds to handle idmappings. Miklos suggested [1], [2] to change the meaning of in.h.uid/in.h.gid fields when daemon declares support for idmapped mounts. In a new semantic, we fill uid/gid values in fuse header with a id-mapped caller uid/gid (for requests which create new inodes), for all the rest cases we just send -1 to userspace. No functional changes intended. Link: https://lore.kernel.org/all/CAJfpegsVY97_5mHSc06mSw79FehFWtoXT=hhTUK_E-Yhr7OAuQ@mail.gmail.com/ [1] Link: https://lore.kernel.org/all/CAJfpegtHQsEUuFq1k4ZbTD3E1h-GsrN3PWyv7X8cg6sfU_W2Yw@mail.gmail.com/ [2] Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-09-03Merge tag 'fuse-fixes-6.11-rc7' of ↵Linus Torvalds-4/+10
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse Pull fuse fixes from Miklos Szeredi: - Fix EIO if splice and page stealing are enabled on the fuse device - Disable problematic combination of passthrough and writeback-cache - Other bug fixes found by code review * tag 'fuse-fixes-6.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: disable the combination of passthrough and writeback cache fuse: update stats for pages in dropped aux writeback list fuse: clear PG_uptodate when using a stolen page fuse: fix memory leak in fuse_create_open fuse: check aborted connection before adding requests to pending list for resending fuse: use unsigned type for getxattr/listxattr size truncation
2024-08-29fuse: add simple request tracepointsJosef Bacik-0/+5
I've been timing various fuse operations and it's quite annoying to do with kprobes. Add two tracepoints for sending and ending fuse requests to make it easier to debug and time various operations. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Bernd Schubert <bschubert@ddn.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-08-29fuse: cleanup request queuing towards virtiofsMiklos Szeredi-72/+87
Virtiofs has its own queuing mechanism, but still requests are first queued on fiq->pending to be immediately dequeued and queued onto the virtio queue. The queuing on fiq->pending is unnecessary and might even have some performance impact due to being a contention point. Forget requests are handled similarly. Move the queuing of requests and forgets into the fiq->ops->*. fuse_iqueue_ops are renamed to reflect the new semantics. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Fixed-by: Jingbo Xu <jefflexu@linux.alibaba.com> Reviewed-by: Jingbo Xu <jefflexu@linux.alibaba.com> Tested-by: Peter-Jan Gootzen <pgootzen@nvidia.com> Reviewed-by: Peter-Jan Gootzen <pgootzen@nvidia.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-08-28fuse: clear PG_uptodate when using a stolen pageMiklos Szeredi-4/+1
Originally when a stolen page was inserted into fuse's page cache by fuse_try_move_page(), it would be marked uptodate. Then fuse_readpages_end() would call SetPageUptodate() again on the already uptodate page. Commit 413e8f014c8b ("fuse: Convert fuse_readpages_end() to use folio_end_read()") changed that by replacing the SetPageUptodate() + unlock_page() combination with folio_end_read(), which does mostly the same, except it sets the uptodate flag with an xor operation, which in the above scenario resulted in the uptodate flag being cleared, which in turn resulted in EIO being returned on the read. Fix by clearing PG_uptodate instead of setting it in fuse_try_move_page(), conforming to the expectation of folio_end_read(). Reported-by: Jürg Billeter <j@bitron.ch> Debugged-by: Matthew Wilcox <willy@infradead.org> Fixes: 413e8f014c8b ("fuse: Convert fuse_readpages_end() to use folio_end_read()") Cc: <stable@vger.kernel.org> # v6.10 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-08-28fuse: check aborted connection before adding requests to pending list for ↵Joanne Koong-0/+9
resending There is a race condition where inflight requests will not be aborted if they are in the middle of being re-sent when the connection is aborted. If fuse_resend has already moved all the requests in the fpq->processing lists to its private queue ("to_queue") and then the connection starts and finishes aborting, these requests will be added to the pending queue and remain on it indefinitely. Fixes: 760eac73f9f6 ("fuse: Introduce a new notification type for resend pending requests") Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Jingbo Xu <jefflexu@linux.alibaba.com> Cc: <stable@vger.kernel.org> # v6.9 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-08-18fuse: Initialize beyond-EOF page contents before setting uptodateJann Horn-2/+4
fuse_notify_store(), unlike fuse_do_readpage(), does not enable page zeroing (because it can be used to change partial page contents). So fuse_notify_store() must be more careful to fully initialize page contents (including parts of the page that are beyond end-of-file) before marking the page uptodate. The current code can leave beyond-EOF page contents uninitialized, which makes these uninitialized page contents visible to userspace via mmap(). This is an information leak, but only affects systems which do not enable init-on-alloc (via CONFIG_INIT_ON_ALLOC_DEFAULT_ON=y or the corresponding kernel command line parameter). Link: https://bugs.chromium.org/p/project-zero/issues/detail?id=2574 Cc: stable@kernel.org Fixes: a1d75f258230 ("fuse: add store request") Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-08-12introduce fd_file(), convert all accessors to it.Al Viro-3/+3
For any changes of struct fd representation we need to turn existing accesses to fields into calls of wrappers. Accesses to struct fd::flags are very few (3 in linux/file.h, 1 in net/socket.c, 3 in fs/overlayfs/file.c and 3 more in explicit initializers). Those can be dealt with in the commit converting to new layout; accesses to struct fd::file are too many for that. This commit converts (almost) all of f.file to fd_file(f). It's not entirely mechanical ('file' is used as a member name more than just in struct fd) and it does not even attempt to distinguish the uses in pointer context from those in boolean context; the latter will be eventually turned into a separate helper (fd_empty()). NOTE: mass conversion to fd_empty(), tempting as it might be, is a bad idea; better do that piecewise in commit that convert from fdget...() to CLASS(...). [conflicts in fs/fhandle.c, kernel/bpf/syscall.c, mm/memcontrol.c caught by git; fs/stat.c one got caught by git grep] [fs/xattr.c conflict] Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-05-10fuse: clear FR_SENT when re-adding requests into pending listHou Tao-0/+1
The following warning was reported by lee bruce: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 8264 at fs/fuse/dev.c:300 fuse_request_end+0x685/0x7e0 fs/fuse/dev.c:300 Modules linked in: CPU: 0 PID: 8264 Comm: ab2 Not tainted 6.9.0-rc7 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) RIP: 0010:fuse_request_end+0x685/0x7e0 fs/fuse/dev.c:300 ...... Call Trace: <TASK> fuse_dev_do_read.constprop.0+0xd36/0x1dd0 fs/fuse/dev.c:1334 fuse_dev_read+0x166/0x200 fs/fuse/dev.c:1367 call_read_iter include/linux/fs.h:2104 [inline] new_sync_read fs/read_write.c:395 [inline] vfs_read+0x85b/0xba0 fs/read_write.c:476 ksys_read+0x12f/0x260 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xce/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f ...... </TASK> The warning is due to the FUSE_NOTIFY_RESEND notify sent by the write() syscall in the reproducer program and it happens as follows: (1) calls fuse_dev_read() to read the INIT request The read succeeds. During the read, bit FR_SENT will be set on the request. (2) calls fuse_dev_write() to send an USE_NOTIFY_RESEND notify The resend notify will resend all processing requests, so the INIT request is moved from processing list to pending list again. (3) calls fuse_dev_read() with an invalid output address fuse_dev_read() will try to copy the same INIT request to the output address, but it will fail due to the invalid address, so the INIT request is ended and triggers the warning in fuse_request_end(). Fix it by clearing FR_SENT when re-adding requests into pending list. Acked-by: Miklos Szeredi <mszeredi@redhat.com> Reported-by: xingwei lee <xrivendell7@gmail.com> Reported-by: yue sun <samsun1006219@gmail.com> Closes: https://lore.kernel.org/linux-fsdevel/58f13e47-4765-fce4-daf4-dffcc5ae2330@huaweicloud.com/T/#m091614e5ea2af403b259e7cea6a49e51b9ee07a7 Fixes: 760eac73f9f6 ("fuse: Introduce a new notification type for resend pending requests") Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-05-10fuse: set FR_PENDING atomically in fuse_resend()Hou Tao-1/+1
When fuse_resend() moves the requests from processing lists to pending list, it uses __set_bit() to set FR_PENDING bit in req->flags. Using __set_bit() is not safe, because other functions may update req->flags concurrently (e.g., request_wait_answer() may call set_bit(FR_INTERRUPTED, &flags)). Fix it by using set_bit() instead. Fixes: 760eac73f9f6 ("fuse: Introduce a new notification type for resend pending requests") Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-03-06fuse: Use the high bit of request ID for indicating resend requestsZhao Chen-0/+2
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-0/+56
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-0/+41
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-26/+33
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-20/+21
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-1/+1
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-0/+2
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-27/+28
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)-27/+28
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)-1/+1
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-2/+1
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-2/+2
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-1/+2
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>
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