kernel/linux.git/fs/fuse/Makefile, branch v6.12.80

fuse: add simple request tracepoints

2024-08-29T09:43:13+00:00

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 Reviewed-by: Bernd Schubert Signed-off-by: Miklos Szeredi

fuse: introduce FUSE_PASSTHROUGH capability

2024-02-23T16:36:32+00:00

FUSE_PASSTHROUGH capability to passthrough FUSE operations to backing files will be made available with kernel config CONFIG_FUSE_PASSTHROUGH. When requesting FUSE_PASSTHROUGH, userspace needs to specify the max_stack_depth that is allowed for FUSE on top of backing files. Introduce the flag FOPEN_PASSTHROUGH and backing_id to fuse_open_out argument that can be used when replying to OPEN request, to setup passthrough of io operations on the fuse inode to a backing file. Introduce a refcounted fuse_backing object that will be used to associate an open backing file with a fuse inode. Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi

fuse: introduce inode io modes

2024-02-23T16:36:32+00:00

The fuse inode io mode is determined by the mode of its open files/mmaps and parallel dio opens and expressed in the value of fi->iocachectr: > 0 - caching io: files open in caching mode or mmap on direct_io file < 0 - parallel dio: direct io mode with parallel dio writes enabled == 0 - direct io: no files open in caching mode and no files mmaped Note that iocachectr value of 0 might become positive or negative, while non-parallel dio is getting processed. direct_io mmap uses page cache, so first mmap will mark the file as ff->io_opened and increment fi->iocachectr to enter the caching io mode. If the server opens the file in caching mode while it is already open for parallel dio or vice versa the open fails. This allows executing parallel dio when inode is not in caching mode and no mmaps have been performed on the inode in question. Signed-off-by: Bernd Schubert Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi

fuse: move ioctl to separate source file

2021-04-12T13:04:30+00:00

Next patch will expand ioctl code and fuse/file.c is large enough as it is. Signed-off-by: Miklos Szeredi

virtiofs: add a mount option to enable dax

2020-09-10T09:39:22+00:00

Add a mount option to allow using dax with virtio_fs. Signed-off-by: Vivek Goyal Signed-off-by: Miklos Szeredi

virtio-fs: Change module name to virtiofs.ko

2019-10-14T08:20:33+00:00

We have been calling it virtio_fs and even file name is virtio_fs.c. Module name is virtio_fs.ko but when registering file system user is supposed to specify filesystem type as "virtiofs". Masayoshi Mizuma reported that he specified filesytem type as "virtio_fs" and got this warning on console. ------------[ cut here ]------------ request_module fs-virtio_fs succeeded, but still no fs? WARNING: CPU: 1 PID: 1234 at fs/filesystems.c:274 get_fs_type+0x12c/0x138 Modules linked in: ... virtio_fs fuse virtio_net net_failover ... CPU: 1 PID: 1234 Comm: mount Not tainted 5.4.0-rc1 #1 So looks like kernel could find the module virtio_fs.ko but could not find filesystem type after that. It probably is better to rename module name to virtiofs.ko so that above warning goes away in case user ends up specifying wrong fs name. Reported-by: Masayoshi Mizuma Suggested-by: Stefan Hajnoczi Signed-off-by: Vivek Goyal Tested-by: Masayoshi Mizuma Reviewed-by: Stefan Hajnoczi Signed-off-by: Miklos Szeredi

virtio-fs: add virtiofs filesystem

2019-09-18T18:17:50+00:00

Add a basic file system module for virtio-fs. This does not yet contain shared data support between host and guest or metadata coherency speedups. However it is already significantly faster than virtio-9p. Design Overview =============== With the goal of designing something with better performance and local file system semantics, a bunch of ideas were proposed. - Use fuse protocol (instead of 9p) for communication between guest and host. Guest kernel will be fuse client and a fuse server will run on host to serve the requests. - For data access inside guest, mmap portion of file in QEMU address space and guest accesses this memory using dax. That way guest page cache is bypassed and there is only one copy of data (on host). This will also enable mmap(MAP_SHARED) between guests. - For metadata coherency, there is a shared memory region which contains version number associated with metadata and any guest changing metadata updates version number and other guests refresh metadata on next access. This is yet to be implemented. How virtio-fs differs from existing approaches ============================================== The unique idea behind virtio-fs is to take advantage of the co-location of the virtual machine and hypervisor to avoid communication (vmexits). DAX allows file contents to be accessed without communication with the hypervisor. The shared memory region for metadata avoids communication in the common case where metadata is unchanged. By replacing expensive communication with cheaper shared memory accesses, we expect to achieve better performance than approaches based on network file system protocols. In addition, this also makes it easier to achieve local file system semantics (coherency). These techniques are not applicable to network file system protocols since the communications channel is bypassed by taking advantage of shared memory on a local machine. This is why we decided to build virtio-fs rather than focus on 9P or NFS. Caching Modes ============= Like virtio-9p, different caching modes are supported which determine the coherency level as well. The “cache=FOO” and “writeback” options control the level of coherence between the guest and host filesystems. - cache=none metadata, data and pathname lookup are not cached in guest. They are always fetched from host and any changes are immediately pushed to host. - cache=always metadata, data and pathname lookup are cached in guest and never expire. - cache=auto metadata and pathname lookup cache expires after a configured amount of time (default is 1 second). Data is cached while the file is open (close to open consistency). - writeback/no_writeback These options control the writeback strategy. If writeback is disabled, then normal writes will immediately be synchronized with the host fs. If writeback is enabled, then writes may be cached in the guest until the file is closed or an fsync(2) performed. This option has no effect on mmap-ed writes or writes going through the DAX mechanism. Signed-off-by: Stefan Hajnoczi Signed-off-by: Vivek Goyal Acked-by: Michael S. Tsirkin Signed-off-by: Miklos Szeredi

treewide: Add SPDX license identifier - Makefile/Kconfig

2019-05-21T08:50:46+00:00

Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

fuse: split out readdir.c

2018-09-28T14:43:23+00:00

Directory reading code is about to grow larger, so split it out from dir.c into a new source file. Signed-off-by: Miklos Szeredi

fuse: Add posix ACL support

2016-10-01T05:32:32+00:00

Add a new INIT flag, FUSE_POSIX_ACL, for negotiating ACL support with userspace. When it is set in the INIT response, ACL support will be enabled. ACL support also implies "default_permissions". When ACL support is enabled, the kernel will cache and have responsibility for enforcing ACLs. ACL xattrs will be passed to userspace, which is responsible for updating the ACLs in the filesystem, keeping the file mode in sync, and inheritance of default ACLs when new filesystem nodes are created. Signed-off-by: Seth Forshee Signed-off-by: Miklos Szeredi