linux/Documentation
Stefan Hajnoczi a8f62f50b4 virtiofs: export filesystem tags through sysfs
The virtiofs filesystem is mounted using a "tag" which is exported by
the virtiofs device:

  # mount -t virtiofs <tag> /mnt

The virtiofs driver knows about all the available tags but these are
currently not exported to user space.

People have asked for these tags to be exported to user space. Most
recently Lennart Poettering has asked for it as he wants to scan the
tags and mount virtiofs automatically in certain cases.

https://gitlab.com/virtio-fs/virtiofsd/-/issues/128

This patch exports tags at /sys/fs/virtiofs/<N>/tag where N is the id of
the virtiofs device. The filesystem tag can be obtained by reading this
"tag" file.

There is also a symlink at /sys/fs/virtiofs/<N>/device that points to
the virtiofs device that exports this tag.

This patch converts the existing struct virtio_fs into a full kobject.
It already had a refcount so it's an easy change. The virtio_fs objects
can then be exposed in a kset at /sys/fs/virtiofs/. Note that virtio_fs
objects may live slightly longer than we wish for them to be exposed to
userspace, so kobject_del() is called explicitly when the underlying
virtio_device is removed. The virtio_fs object is freed when all
references are dropped (e.g. active mounts) but disappears as soon as
the virtiofs device is gone.

Originally-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-02-23 09:40:26 +01:00
..
ABI virtiofs: export filesystem tags through sysfs 2024-02-23 09:40:26 +01:00
accel docs/accel: correct links to mailing list archives 2024-01-23 14:45:50 -07:00
accounting
admin-guide docs: admin-guide: remove obsolete advice related to SLAB allocator 2024-01-23 14:52:37 -07:00
arch arm64: Subscribe Microsoft Azure Cobalt 100 to ARM Neoverse N2 errata 2024-02-15 11:47:22 +00:00
block Documentation: block: ioprio: Update schedulers 2024-01-18 08:21:14 -07:00
bpf Another moderately busy cycle for documentation, including: 2024-01-11 19:46:52 -08:00
cdrom
core-api A handful of late-arriving documentation fixes. 2024-01-17 11:49:11 -08:00
cpu-freq
crypto Another moderately busy cycle for documentation, including: 2024-01-11 19:46:52 -08:00
dev-tools Documentation: KUnit: Update the instructions on how to test static functions 2024-01-22 07:59:03 -07:00
devicetree sound fixes for 6.8-rc5 2024-02-16 09:02:19 -08:00
doc-guide docs: Raise the minimum Sphinx requirement to 2.4.4 2023-12-15 08:36:33 -07:00
driver-api pci-v6.8-changes 2024-01-17 16:23:17 -08:00
fault-injection
fb fbdev/intelfb: Remove driver 2024-01-12 12:38:37 +01:00
features riscv: Add support for BATCHED_UNMAP_TLB_FLUSH 2024-01-11 08:01:53 -08:00
filesystems ovl: mark xwhiteouts directory with overlay.opaque='x' 2024-01-23 12:39:48 +02:00
firmware_class
firmware-guide
fpga
gpu amd-drm-next-6.8-2024-01-05: 2024-01-09 09:07:50 +10:00
hid
hwmon hwmon: (lm75) Add AMS AS6200 temperature sensor 2024-01-02 08:44:57 -08:00
i2c Documentation/i2c: fix spelling error in i2c-address-translators 2023-12-27 20:05:44 +01:00
iio
images
infiniband
input
isdn
kbuild docs: kconfig: Fix grammar and formatting 2024-02-15 06:55:47 +09:00
kernel-hacking
leds
litmus-tests
livepatch
locking locking/mutex: Clarify that mutex_unlock(), and most other sleeping locks, can still use the lock object after it's unlocked 2024-01-08 09:55:31 +01:00
maintainer
mhi
misc-devices
mm mm/rmap: rename COMPOUND_MAPPED to ENTIRELY_MAPPED 2023-12-29 11:58:56 -08:00
netlabel
netlink dpll: fix possible deadlock during netlink dump operation 2024-02-08 18:29:21 -08:00
networking net-device: move lstats in net_device_read_txrx 2024-02-12 09:51:26 +00:00
nvdimm
nvme
PCI docs: PCI: Fix typos 2023-12-28 17:37:36 -06:00
pcmcia
peci
power Documentation: PM: Adjust freezing-of-tasks.rst to the freezer changes 2023-12-19 21:14:32 +01:00
process Documentation: Document the Linux Kernel CVE process 2024-02-17 14:46:39 +01:00
RAS
RCU doc: Mention address and data dependencies in rcu_dereference.rst 2023-12-14 01:16:28 +05:30
rust LoongArch changes for v6.8 2024-01-19 13:30:49 -08:00
scheduler sched/fair: Remove SCHED_FEAT(UTIL_EST_FASTUP, true) 2023-12-23 15:59:56 +01:00
scsi
security
sound
sphinx docs: kernel_feat.py: fix build error for missing files 2024-02-08 11:05:35 -07:00
sphinx-static docs: translations: add translations links when they exist 2023-12-19 14:34:59 -07:00
spi
staging rpmsg updates for v6.8 2024-01-17 15:05:27 -08:00
target
tee
timers
tools
trace tracing updates for 6.8: 2024-01-18 14:35:29 -08:00
translations A handful of late-arriving documentation fixes. 2024-01-17 11:49:11 -08:00
usb usb: gadget: ncm: Fix indentations in documentation of NCM section 2024-01-27 16:27:58 -08:00
userspace-api fbdev fixes and cleanups for 6.8-rc1: 2024-01-12 14:38:08 -08:00
virt KVM x86 MMU changes for 6.8: 2024-01-08 08:10:32 -05:00
w1
watchdog
wmi
.gitignore
atomic_bitops.txt
atomic_t.txt
Changes
CodingStyle
conf.py docs: translations: add translations links when they exist 2023-12-19 14:34:59 -07:00
docutils.conf
dontdiff
index.rst
Kconfig
Makefile doc/netlink: Regenerate netlink .rst files if ynl-gen-rst changes 2023-12-18 14:39:44 -08:00
memory-barriers.txt doc: Clarify historical disclaimers in memory-barriers.txt 2023-12-14 01:16:28 +05:30
SubmittingPatches
subsystem-apis.rst