These inodes can never be part of a filesystem tree. They are nameless and
never have a parent.
This allows us to avoid taking a lock in kernfs.InotifyWithParent for such
anonymous inodes.
PiperOrigin-RevId: 538823227
This is consistent with Linux. Some applications recursively add
files to inotify FD. They fail if they run into kernfs files
because inotify_add_watch(2) returns EPERM in that case.
PiperOrigin-RevId: 462642204
Added the following fields in kernfs.InodeAttr:
- blockSize
- atime
- mtime
- ctime
Also resolved all TODOs for #1193.
Fixes#1193
PiperOrigin-RevId: 338714527
Singleton filesystem like devpts and devtmpfs have a single filesystem shared
among all mounts, so they acquire a "self-reference" when initialized that
must be released when the entire virtual filesystem is released at sandbox
exit.
PiperOrigin-RevId: 336828852
This change aims to fix the memory leak issue reported in #3933.
Background:
VFS2 kernfs kept accumulating invalid dentries if those dentries were not
walked on. After substantial consideration of the problem by our team, we
decided to have an LRU cache solution. This change is the first part to that
solution, where we don't cache anything. The LRU cache can be added on top of
this.
What has changed:
- Introduced the concept of an inode tree in kernfs.OrderedChildren.
This is helpful is cases where the lifecycle of an inode is different from
that of a dentry.
- OrderedChildren now deals with initialized inodes instead of initialized
dentries. It now implements Lookup() where it constructs a new dentry
using the inode.
- OrderedChildren holds a ref on all its children inodes. With this change,
now an inode can "outlive" a dentry pointing to it. See comments in
kernfs.OrderedChildren.
- The kernfs dentry tree is solely maintained by kernfs only. Inode
implementations can not modify the dentry tree.
- Dentries that reach ref count 0 are removed from the dentry tree.
- revalidateChildLocked now defer-DecRefs the newly created dentry from
Inode.Lookup(), limiting its life to the current filesystem operation. If
refs are picked on the dentry during the FS op (via an FD or something),
then it will stick around and will be removed when the FD is closed. So there
is essentially _no caching_ for Look()ed up dentries.
- kernfs.DecRef does not have the precondition that fs.mu must be locked.
Fixes#3933
PiperOrigin-RevId: 336768576
As noticed by @ayushr2, the "implements" comments are not
consistent, e.g.
// IterDirents implements kernfs.inodeDynamicLookup.
// Generate implements vfs.DynamicBytesSource.Generate.
This patch improves this by making the comments like this
consistently include the package name (when the interface
and struct are not in the same package) and method name.
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Three updates:
- Mark all vfs2 socket syscalls as supported.
- Use the same dev number and ino number generator for all types of sockets,
unlike in VFS1.
- Do not use host fd for hostinet metadata.
Fixes#1476, #1478, #1484, 1485, #2017.
PiperOrigin-RevId: 309994579
All three follow the same pattern:
1. Refactor VFS1 sockets into socketOpsCommon, so that most of the methods can
be shared with VFS2.
2. Create a FileDescriptionImpl with the corresponding socket operations,
rewriting the few that cannot be shared with VFS1.
3. Set up a VFS2 socket provider that creates a socket by setting up a dentry
in the global Kernel.socketMount and connecting it with a new
FileDescription.
This mostly completes the work for porting sockets to VFS2, and many syscall
tests can be enabled as a result.
There are several networking-related syscall tests that are still not passing:
1. net gofer tests
2. socketpair gofer tests
2. sendfile tests (splice is not implemented in VFS2 yet)
Updates #1478, #1484, #1485
PiperOrigin-RevId: 309457331
The FileDescription implementation for hostfs sockets uses the standard Unix
socket implementation (unix.SocketVFS2), but is also tied to a hostfs dentry.
Updates #1672, #1476
PiperOrigin-RevId: 308716426
This is needed to set up host fds passed through a Unix socket. Note that
the host package depends on kernel, so we cannot set up the hostfs mount
directly in Kernel.Init as we do for sockfs and pipefs.
Also, adjust sockfs to make its setup look more like hostfs's and pipefs's.
PiperOrigin-RevId: 308274053
This change involves several steps:
- Refactor the VFS1 unix socket implementation to share methods between VFS1
and VFS2 where possible. Re-implement the rest.
- Override the default PRead, Read, PWrite, Write, Ioctl, Release methods in
FileDescriptionDefaultImpl.
- Add functions to create and initialize a new Dentry/Inode and FileDescription
for a Unix socket file.
Updates #1476
PiperOrigin-RevId: 304689796
A socket mount where anonymous sockets will reside is added to the
VirtualFilesystem. Socketfs is built on top of kernfs.
Updates #1476, #1478, #1484, #1485.
PiperOrigin-RevId: 304095251
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