Commit Graph

350 Commits

Author SHA1 Message Date
Al Viro
cb787f4ac0 [tree-wide] finally take no_llseek out
no_llseek had been defined to NULL two years ago, in commit 868941b144
("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>
2024-09-27 08:18:43 -07:00
Linus Torvalds
f7fccaa772 fuse update for 6.12
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Merge tag 'fuse-update-6.12' of 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
  ...
2024-09-24 15:29:42 -07:00
Miklos Szeredi
fcd2d9e1fd fuse: clear FR_PENDING if abort is detected when sending request
The (!fiq->connected) check was moved into the queuing method resulting in
the following:

Fixes: 5de8acb41c ("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>
2024-09-24 10:56:09 +02:00
Linus Torvalds
f8ffbc365f struct fd layout change (and conversion to accessor helpers)
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Merge tag 'pull-stable-struct_fd' of 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.
2024-09-23 09:35:36 -07:00
Alexander Mikhalitsyn
106e4593ed fs/fuse: convert to use invalid_mnt_idmap
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>
2024-09-23 11:10:26 +02:00
Alexander Mikhalitsyn
0c6793823d fs/fuse: introduce and use fuse_simple_idmap_request() helper
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>
2024-09-23 11:07:55 +02:00
Alexander Mikhalitsyn
3988a60d3a fs/fuse: fix null-ptr-deref when checking SB_I_NOIDMAP flag
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: aa16880d9f ("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>
2024-09-23 11:02:25 +02:00
Alexander Mikhalitsyn
10dc721836 fuse: add an idmap argument to fuse_simple_request
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>
2024-09-04 16:48:22 +02:00
Alexander Mikhalitsyn
aa16880d9f fuse: add basic infrastructure to support idmappings
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>
2024-09-04 16:48:22 +02:00
Linus Torvalds
88fac17500 fuse fixes for 6.11-rc7
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Merge tag 'fuse-fixes-6.11-rc7' of 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
2024-09-03 12:32:00 -07:00
Josef Bacik
396b209e40 fuse: add simple request tracepoints
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>
2024-08-29 11:43:13 +02:00
Miklos Szeredi
5de8acb41c fuse: cleanup request queuing towards virtiofs
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>
2024-08-29 11:43:12 +02:00
Miklos Szeredi
76a51ac00c fuse: clear PG_uptodate when using a stolen page
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 413e8f014c ("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: 413e8f014c ("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>
2024-08-28 18:10:29 +02:00
Joanne Koong
97f30876c9 fuse: check aborted connection before adding requests to pending list for 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: 760eac73f9 ("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>
2024-08-28 18:10:29 +02:00
Jann Horn
3c0da3d163 fuse: Initialize beyond-EOF page contents before setting uptodate
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: a1d75f2582 ("fuse: add store request")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-08-18 08:45:39 -07:00
Al Viro
1da91ea87a introduce fd_file(), convert all accessors to it.
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>
2024-08-12 22:00:43 -04:00
Hou Tao
246014876d fuse: clear FR_SENT when re-adding requests into pending list
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: 760eac73f9 ("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>
2024-05-10 11:10:39 +02:00
Hou Tao
42815f8ac5 fuse: set FR_PENDING atomically in fuse_resend()
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: 760eac73f9 ("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>
2024-05-10 11:10:12 +02:00
Zhao Chen
9e7f5296f4 fuse: Use the high bit of request ID for indicating resend requests
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>
2024-03-06 09:56:35 +01:00
Zhao Chen
760eac73f9 fuse: Introduce a new notification type for resend pending requests
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>
2024-03-06 09:56:34 +01:00
Amir Goldstein
44350256ab fuse: implement ioctls to manage backing files
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>
2024-03-05 13:40:36 +01:00
Amir Goldstein
aed918310e fuse: factor out helper for FUSE_DEV_IOC_CLONE
In preparation to adding more fuse dev ioctls.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-02-23 17:36:32 +01:00
Al Viro
4a892c0fe4 fuse_dev_ioctl(): switch to fdget()
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2023-04-20 22:55:35 -04:00
Randy Dunlap
06bbb761c1 fuse: fix all W=1 kernel-doc warnings
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>
2023-01-26 17:10:58 +01:00
Miklos Szeredi
15d937d7ca fuse: add request extension
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>
2023-01-26 17:10:37 +01:00
Linus Torvalds
e2ca6ba6ba MM patches for 6.2-rc1.
- 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 shold 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.
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Merge tag 'mm-stable-2022-12-13' of 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
  ...
2022-12-13 19:29:45 -08:00
Vishal Moola (Oracle)
063aaad792 fuse: convert fuse_try_move_page() to use folios
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>
2022-12-11 18:12:12 -08:00
Vishal Moola (Oracle)
3720dd6dca filemap: convert replace_page_cache_page() to replace_page_cache_folio()
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>
2022-12-11 18:12:12 -08:00
Jann Horn
0618021e34 fuse: Remove user_ns check for FUSE_DEV_IOC_CLONE
Commit 8ed1f0e22f ("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 8cb08329b0
("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>
2022-11-23 09:10:49 +01:00
Miklos Szeredi
4f8d37020e fuse: add "expire only" mode to FUSE_NOTIFY_INVAL_ENTRY
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>
2022-11-23 09:10:49 +01:00
Yu Zhao
ec1c86b25f mm: multi-gen LRU: groundwork
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>
2022-09-26 19:46:09 -07:00
Al Viro
1ef255e257 iov_iter: advancing variants of iov_iter_get_pages{,_alloc}()
Most of the users immediately follow successful iov_iter_get_pages()
with advancing by the amount it had returned.

Provide inline wrappers doing that, convert trivial open-coded
uses of those.

BTW, iov_iter_get_pages() never returns more than it had been asked
to; such checks in cifs ought to be removed someday...

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08 22:37:22 -04:00
Al Viro
fcb14cb1bd new iov_iter flavour - ITER_UBUF
Equivalent of single-segment iovec.  Initialized by iov_iter_ubuf(),
checked for by iter_is_ubuf(), otherwise behaves like ITER_IOVEC
ones.

We are going to expose the things like ->write_iter() et.al. to those
in subsequent commits.

New predicate (user_backed_iter()) that is true for ITER_IOVEC and
ITER_UBUF; places like direct-IO handling should use that for
checking that pages we modify after getting them from iov_iter_get_pages()
would need to be dirtied.

DO NOT assume that replacing iter_is_iovec() with user_backed_iter()
will solve all problems - there's code that uses iter_is_iovec() to
decide how to poke around in iov_iter guts and for that the predicate
replacement obviously won't suffice.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08 22:37:15 -04:00
NeilBrown
670d21c6e1 fuse: remove reliance on bdi congestion
The bdi congestion tracking in not widely used and will be removed.

Fuse is one of a small number of filesystems that uses it, setting both
the sync (read) and async (write) congestion flags at what it determines
are appropriate times.

The only remaining effect of the sync flag is to cause read-ahead to be
skipped.  The only remaining effect of the async flag is to cause (some)
WB_SYNC_NONE writes to be skipped.

So instead of setting the flags, change:

 - .readahead to stop when it has submitted all non-async pages for
   read.

 - .writepages to do nothing if WB_SYNC_NONE and the flag would be set

 - .writepage to return AOP_WRITEPAGE_ACTIVATE if WB_SYNC_NONE and the
   flag would be set.

The writepages change causes a behavioural change in that pageout() can
now return PAGE_ACTIVATE instead of PAGE_KEEP, so SetPageActive() will be
called on the page which (I think) will further delay the next attempt at
writeout.  This might be a good thing.

Link: https://lkml.kernel.org/r/164549983737.9187.2627117501000365074.stgit@noble.brown
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Anna Schumaker <Anna.Schumaker@Netapp.com>
Cc: Chao Yu <chao@kernel.org>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Lars Ellenberg <lars.ellenberg@linbit.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Paolo Valente <paolo.valente@linaro.org>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22 15:57:00 -07:00
Miklos Szeredi
0c4bcfdecb fuse: fix pipe buffer lifetime for direct_io
In FOPEN_DIRECT_IO mode, fuse_file_write_iter() calls
fuse_direct_write_iter(), which normally calls fuse_direct_io(), which then
imports the write buffer with fuse_get_user_pages(), which uses
iov_iter_get_pages() to grab references to userspace pages instead of
actually copying memory.

On the filesystem device side, these pages can then either be read to
userspace (via fuse_dev_read()), or splice()d over into a pipe using
fuse_dev_splice_read() as pipe buffers with &nosteal_pipe_buf_ops.

This is wrong because after fuse_dev_do_read() unlocks the FUSE request,
the userspace filesystem can mark the request as completed, causing write()
to return. At that point, the userspace filesystem should no longer have
access to the pipe buffer.

Fix by copying pages coming from the user address space to new pipe
buffers.

Reported-by: Jann Horn <jannh@google.com>
Fixes: c3021629a0 ("fuse: support splice() reading from fuse device")
Cc: <stable@vger.kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2022-03-07 16:30:44 +01:00
Miklos Szeredi
473441720c fuse: release pipe buf after last use
Checking buf->flags should be done before the pipe_buf_release() is called
on the pipe buffer, since releasing the buffer might modify the flags.

This is exactly what page_cache_pipe_buf_release() does, and which results
in the same VM_BUG_ON_PAGE(PageLRU(page)) that the original patch was
trying to fix.

Reported-by: Justin Forbes <jmforbes@linuxtx.org>
Fixes: 712a951025 ("fuse: fix page stealing")
Cc: <stable@vger.kernel.org> # v2.6.35
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-11-25 14:05:18 +01:00
Miklos Szeredi
712a951025 fuse: fix page stealing
It is possible to trigger a crash by splicing anon pipe bufs to the fuse
device.

The reason for this is that anon_pipe_buf_release() will reuse buf->page if
the refcount is 1, but that page might have already been stolen and its
flags modified (e.g. PG_lru added).

This happens in the unlikely case of fuse_dev_splice_write() getting around
to calling pipe_buf_release() after a page has been stolen, added to the
page cache and removed from the page cache.

Fix by calling pipe_buf_release() right after the page was inserted into
the page cache.  In this case the page has an elevated refcount so any
release function will know that the page isn't reusable.

Reported-by: Frank Dinoff <fdinoff@google.com>
Link: https://lore.kernel.org/r/CAAmZXrsGg2xsP1CK+cbuEMumtrqdvD-NKnWzhNcvn71RV3c1yw@mail.gmail.com/
Fixes: dd3bb14f44 ("fuse: support splice() writing to fuse device")
Cc: <stable@vger.kernel.org> # v2.6.35
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-11-02 11:10:37 +01:00
Miklos Szeredi
d347739a0e fuse: always invalidate attributes after writes
Extend the fuse_write_update_attr() helper to invalidate cached attributes
after a write.

This has already been done in all cases except in fuse_notify_store(), so
this is mostly a cleanup.

fuse_direct_write_iter() calls fuse_direct_IO() which already calls
fuse_write_update_attr(), so don't repeat that again in the former.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28 09:45:32 +02:00
Miklos Szeredi
27ae449ba2 fuse: rename fuse_write_update_size()
This function already updates the attr_version in fuse_inode, regardless of
whether the size was changed or not.

Rename the helper to fuse_write_update_attr() to reflect the more generic
nature.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28 09:45:32 +02:00
Peng Hao
5fe0fc9f1d fuse: use kmap_local_page()
Due to the introduction of kmap_local_*, the storage of slots used for
short-term mapping has changed from per-CPU to per-thread.  kmap_atomic()
disable preemption, while kmap_local_*() only disable migration.

There is no need to disable preemption in several kamp_atomic places used
in fuse.

Link: https://lwn.net/Articles/836144/
Signed-off-by: Peng Hao <flyingpeng@tencent.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-22 17:03:01 +02:00
Miklos Szeredi
e1e71c1688 fuse: fix use after free in fuse_read_interrupt()
There is a potential race between fuse_read_interrupt() and
fuse_request_end().

TASK1
  in fuse_read_interrupt(): delete req->intr_entry (while holding
  fiq->lock)

TASK2
  in fuse_request_end(): req->intr_entry is empty -> skip fiq->lock
  wake up TASK3

TASK3
  request is freed

TASK1
  in fuse_read_interrupt(): dereference req->in.h.unique ***BAM***


Fix by always grabbing fiq->lock if the request was ever interrupted
(FR_INTERRUPTED set) thereby serializing with concurrent
fuse_read_interrupt() calls.

FR_INTERRUPTED is set before the request is queued on fiq->interrupts.
Dequeing the request is done with list_del_init() but FR_INTERRUPTED is not
cleared in this case.

Reported-by: lijiazi <lijiazi@xiaomi.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-08-04 13:22:58 +02:00
Zheng Yongjun
c4e0cd4e0c virtiofs: Fix spelling mistakes
Fix some spelling mistakes in comments:
refernce  ==> reference
happnes  ==> happens
threhold  ==> threshold
splitted  ==> split
mached  ==> matched

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-22 09:15:36 +02:00
Miklos Szeredi
49221cf86d fuse: reject internal errno
Don't allow userspace to report errors that could be kernel-internal.

Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Fixes: 334f485df8 ("[PATCH] FUSE - device functions")
Cc: <stable@vger.kernel.org> # v2.6.14
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-22 09:15:35 +02:00
Miklos Szeredi
80ef08670d fuse: check connected before queueing on fpq->io
A request could end up on the fpq->io list after fuse_abort_conn() has
reset fpq->connected and aborted requests on that list:

Thread-1			  Thread-2
========			  ========
->fuse_simple_request()           ->shutdown
  ->__fuse_request_send()
    ->queue_request()		->fuse_abort_conn()
->fuse_dev_do_read()                ->acquire(fpq->lock)
  ->wait_for(fpq->lock) 	  ->set err to all req's in fpq->io
				  ->release(fpq->lock)
  ->acquire(fpq->lock)
  ->add req to fpq->io

After the userspace copy is done the request will be ended, but
req->out.h.error will remain uninitialized.  Also the copy might block
despite being already aborted.

Fix both issues by not allowing the request to be queued on the fpq->io
list after fuse_abort_conn() has processed this list.

Reported-by: Pradeep P V K <pragalla@codeaurora.org>
Fixes: fd22d62ed0 ("fuse: no fc->lock for iqueue parts")
Cc: <stable@vger.kernel.org> # v4.2
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-22 09:15:35 +02:00
Miklos Szeredi
b89ecd60d3 fuse: ignore PG_workingset after stealing
Fix the "fuse: trying to steal weird page" warning.

Description from Johannes Weiner:

  "Think of it as similar to PG_active. It's just another usage/heat
   indicator of file and anon pages on the reclaim LRU that, unlike
   PG_active, persists across deactivation and even reclaim (we store it in
   the page cache / swapper cache tree until the page refaults).

   So if fuse accepts pages that can legally have PG_active set,
   PG_workingset is fine too."

Reported-by: Thomas Lindroth <thomas.lindroth@gmail.com>
Fixes: 1899ad18c6 ("mm: workingset: tell cache transitions from workingset thrashing")
Cc: <stable@vger.kernel.org> # v4.20
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-18 21:16:42 +02:00
Alessio Balsini
6076f5f341 fuse: fix matching of FUSE_DEV_IOC_CLONE command
With commit f8425c9396 ("fuse: 32-bit user space ioctl compat for fuse
device") the matching constraints for the FUSE_DEV_IOC_CLONE ioctl command
are relaxed, limited to the testing of command type and number.  As Arnd
noticed, this is wrong as it wouldn't ensure the correctness of the data
size or direction for the received FUSE device ioctl.

Fix by bringing back the comparison of the ioctl received by the FUSE
device to the originally generated FUSE_DEV_IOC_CLONE.

Fixes: f8425c9396 ("fuse: 32-bit user space ioctl compat for fuse device")
Reported-by: Arnd Bergmann <arnd@kernel.org>
Signed-off-by: Alessio Balsini <balsini@android.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-14 10:40:57 +02:00
Alessio Balsini
f8425c9396 fuse: 32-bit user space ioctl compat for fuse device
With a 64-bit kernel build the FUSE device cannot handle ioctl requests
coming from 32-bit user space.  This is due to the ioctl command
translation that generates different command identifiers that thus cannot
be used for direct comparisons without proper manipulation.

Explicitly extract type and number from the ioctl command to enable 32-bit
user space compatibility on 64-bit kernel builds.

Signed-off-by: Alessio Balsini <balsini@android.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-03-16 15:20:16 +01:00
Baolin Wang
1f7ef65774 mm/filemap: remove unused parameter and change to void type for replace_page_cache_page()
Since commit 74d609585d ("page cache: Add and replace pages using the
XArray") was merged, the replace_page_cache_page() can not fail and always
return 0, we can remove the redundant return value and void it.  Moreover
remove the unused gfp_mask.

Link: https://lkml.kernel.org/r/609c30e5274ba15d8b90c872fd0d8ac437a9b2bb.1610071401.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:27 -08:00
Max Reitz
fcee216beb fuse: split fuse_mount off of fuse_conn
We want to allow submounts for the same fuse_conn, but with different
superblocks so that each of the submounts has its own device ID.  To do
so, we need to split all mount-specific information off of fuse_conn
into a new fuse_mount structure, so that multiple mounts can share a
single fuse_conn.

We need to take care only to perform connection-level actions once (i.e.
when the fuse_conn and thus the first fuse_mount are established, or
when the last fuse_mount and thus the fuse_conn are destroyed).  For
example, fuse_sb_destroy() must invoke fuse_send_destroy() until the
last superblock is released.

To do so, we keep track of which fuse_mount is the root mount and
perform all fuse_conn-level actions only when this fuse_mount is
involved.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-18 15:17:41 +02:00
Max Reitz
8f622e9497 fuse: drop fuse_conn parameter where possible
With the last commit, all functions that handle some existing fuse_req
no longer need to be given the associated fuse_conn, because they can
get it from the fuse_req object.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-18 15:17:41 +02:00