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authorkevin.xu <cming.xu@gmail.com>2020-04-27 21:51:31 +0800
committerGitHub <noreply@github.com>2020-04-27 21:51:31 +0800
commite896ca54db67524afc20b644d43c72185e72dc0e (patch)
tree2a16f3a62a5cafd098f1f028c621f1b655589d69 /pkg/sentry/kernel/fs_context.go
parent1f19624fa127d7d59cabe29593cc80b7fe6c81f8 (diff)
parent3c67754663f424f2ebbc0ff2a4c80e30618d5355 (diff)
Merge pull request #1 from google/master
catch up
Diffstat (limited to 'pkg/sentry/kernel/fs_context.go')
-rw-r--r--pkg/sentry/kernel/fs_context.go122
1 files changed, 108 insertions, 14 deletions
diff --git a/pkg/sentry/kernel/fs_context.go b/pkg/sentry/kernel/fs_context.go
index ded27d668..47f78df9a 100644
--- a/pkg/sentry/kernel/fs_context.go
+++ b/pkg/sentry/kernel/fs_context.go
@@ -16,10 +16,11 @@ package kernel
import (
"fmt"
- "sync"
"gvisor.dev/gvisor/pkg/refs"
"gvisor.dev/gvisor/pkg/sentry/fs"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/sync"
)
// FSContext contains filesystem context.
@@ -37,10 +38,16 @@ type FSContext struct {
// destroyed.
root *fs.Dirent
+ // rootVFS2 is the filesystem root.
+ rootVFS2 vfs.VirtualDentry
+
// cwd is the current working directory. Will be nil iff the FSContext
// has been destroyed.
cwd *fs.Dirent
+ // cwdVFS2 is the current working directory.
+ cwdVFS2 vfs.VirtualDentry
+
// umask is the current file mode creation mask. When a thread using this
// context invokes a syscall that creates a file, bits set in umask are
// removed from the permissions that the file is created with.
@@ -60,6 +67,19 @@ func newFSContext(root, cwd *fs.Dirent, umask uint) *FSContext {
return &f
}
+// NewFSContextVFS2 returns a new filesystem context.
+func NewFSContextVFS2(root, cwd vfs.VirtualDentry, umask uint) *FSContext {
+ root.IncRef()
+ cwd.IncRef()
+ f := FSContext{
+ rootVFS2: root,
+ cwdVFS2: cwd,
+ umask: umask,
+ }
+ f.EnableLeakCheck("kernel.FSContext")
+ return &f
+}
+
// destroy is the destructor for an FSContext.
//
// This will call DecRef on both root and cwd Dirents. If either call to
@@ -75,11 +95,17 @@ func (f *FSContext) destroy() {
f.mu.Lock()
defer f.mu.Unlock()
- f.root.DecRef()
- f.root = nil
-
- f.cwd.DecRef()
- f.cwd = nil
+ if VFS2Enabled {
+ f.rootVFS2.DecRef()
+ f.rootVFS2 = vfs.VirtualDentry{}
+ f.cwdVFS2.DecRef()
+ f.cwdVFS2 = vfs.VirtualDentry{}
+ } else {
+ f.root.DecRef()
+ f.root = nil
+ f.cwd.DecRef()
+ f.cwd = nil
+ }
}
// DecRef implements RefCounter.DecRef with destructor f.destroy.
@@ -93,12 +119,21 @@ func (f *FSContext) DecRef() {
func (f *FSContext) Fork() *FSContext {
f.mu.Lock()
defer f.mu.Unlock()
- f.cwd.IncRef()
- f.root.IncRef()
+
+ if VFS2Enabled {
+ f.cwdVFS2.IncRef()
+ f.rootVFS2.IncRef()
+ } else {
+ f.cwd.IncRef()
+ f.root.IncRef()
+ }
+
return &FSContext{
- cwd: f.cwd,
- root: f.root,
- umask: f.umask,
+ cwd: f.cwd,
+ root: f.root,
+ cwdVFS2: f.cwdVFS2,
+ rootVFS2: f.rootVFS2,
+ umask: f.umask,
}
}
@@ -109,12 +144,23 @@ func (f *FSContext) Fork() *FSContext {
func (f *FSContext) WorkingDirectory() *fs.Dirent {
f.mu.Lock()
defer f.mu.Unlock()
- if f.cwd != nil {
- f.cwd.IncRef()
- }
+
+ f.cwd.IncRef()
return f.cwd
}
+// WorkingDirectoryVFS2 returns the current working directory.
+//
+// This will return nil if called after destroy(), otherwise it will return a
+// Dirent with a reference taken.
+func (f *FSContext) WorkingDirectoryVFS2() vfs.VirtualDentry {
+ f.mu.Lock()
+ defer f.mu.Unlock()
+
+ f.cwdVFS2.IncRef()
+ return f.cwdVFS2
+}
+
// SetWorkingDirectory sets the current working directory.
// This will take an extra reference on the Dirent.
//
@@ -137,6 +183,20 @@ func (f *FSContext) SetWorkingDirectory(d *fs.Dirent) {
old.DecRef()
}
+// SetWorkingDirectoryVFS2 sets the current working directory.
+// This will take an extra reference on the VirtualDentry.
+//
+// This is not a valid call after destroy.
+func (f *FSContext) SetWorkingDirectoryVFS2(d vfs.VirtualDentry) {
+ f.mu.Lock()
+ defer f.mu.Unlock()
+
+ old := f.cwdVFS2
+ f.cwdVFS2 = d
+ d.IncRef()
+ old.DecRef()
+}
+
// RootDirectory returns the current filesystem root.
//
// This will return nil if called after destroy(), otherwise it will return a
@@ -150,6 +210,18 @@ func (f *FSContext) RootDirectory() *fs.Dirent {
return f.root
}
+// RootDirectoryVFS2 returns the current filesystem root.
+//
+// This will return nil if called after destroy(), otherwise it will return a
+// Dirent with a reference taken.
+func (f *FSContext) RootDirectoryVFS2() vfs.VirtualDentry {
+ f.mu.Lock()
+ defer f.mu.Unlock()
+
+ f.rootVFS2.IncRef()
+ return f.rootVFS2
+}
+
// SetRootDirectory sets the root directory.
// This will take an extra reference on the Dirent.
//
@@ -172,6 +244,28 @@ func (f *FSContext) SetRootDirectory(d *fs.Dirent) {
old.DecRef()
}
+// SetRootDirectoryVFS2 sets the root directory. It takes a reference on vd.
+//
+// This is not a valid call after free.
+func (f *FSContext) SetRootDirectoryVFS2(vd vfs.VirtualDentry) {
+ if !vd.Ok() {
+ panic("FSContext.SetRootDirectoryVFS2 called with zero-value VirtualDentry")
+ }
+
+ f.mu.Lock()
+
+ if !f.rootVFS2.Ok() {
+ f.mu.Unlock()
+ panic(fmt.Sprintf("FSContext.SetRootDirectoryVFS2(%v)) called after destroy", vd))
+ }
+
+ old := f.rootVFS2
+ vd.IncRef()
+ f.rootVFS2 = vd
+ f.mu.Unlock()
+ old.DecRef()
+}
+
// Umask returns the current umask.
func (f *FSContext) Umask() uint {
f.mu.Lock()