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authorgVisor bot <gvisor-bot@google.com>2020-09-17 00:16:04 +0000
committergVisor bot <gvisor-bot@google.com>2020-09-17 00:16:04 +0000
commit422a0ed80273a8c08ae28c7b5e754c436fb0d574 (patch)
tree80e08c1124b9011e48ed75dfdd00f72de2f6fdae /pkg/sentry/fsimpl/kernfs
parent5885666c146218d4c845cb6030f657c3e0f75ecd (diff)
parentae59e529791e4763aaa25eee818605f17699fc67 (diff)
Merge release-20200907.0-120-gae59e5297 (automated)
Diffstat (limited to 'pkg/sentry/fsimpl/kernfs')
-rw-r--r--pkg/sentry/fsimpl/kernfs/filesystem.go17
-rw-r--r--pkg/sentry/fsimpl/kernfs/inode_impl_util.go9
-rw-r--r--pkg/sentry/fsimpl/kernfs/kernfs.go41
-rw-r--r--pkg/sentry/fsimpl/kernfs/symlink.go2
4 files changed, 58 insertions, 11 deletions
diff --git a/pkg/sentry/fsimpl/kernfs/filesystem.go b/pkg/sentry/fsimpl/kernfs/filesystem.go
index d7d3e8f48..49f6a0f1d 100644
--- a/pkg/sentry/fsimpl/kernfs/filesystem.go
+++ b/pkg/sentry/fsimpl/kernfs/filesystem.go
@@ -140,7 +140,7 @@ func (fs *Filesystem) revalidateChildLocked(ctx context.Context, vfsObj *vfs.Vir
}
// Reference on childVFSD dropped by a corresponding Valid.
child = childVFSD.Impl().(*Dentry)
- parent.insertChildLocked(name, child)
+ parent.InsertChildLocked(name, child)
}
return child, nil
}
@@ -548,7 +548,7 @@ func (fs *Filesystem) ReadlinkAt(ctx context.Context, rp *vfs.ResolvingPath) (st
if !d.Impl().(*Dentry).isSymlink() {
return "", syserror.EINVAL
}
- return inode.Readlink(ctx)
+ return inode.Readlink(ctx, rp.Mount())
}
// RenameAt implements vfs.FilesystemImpl.RenameAt.
@@ -657,6 +657,10 @@ func (fs *Filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa
func (fs *Filesystem) RmdirAt(ctx context.Context, rp *vfs.ResolvingPath) error {
fs.mu.Lock()
defer fs.mu.Unlock()
+
+ // Store the name before walkExistingLocked as rp will be advanced past the
+ // name in the following call.
+ name := rp.Component()
vfsd, inode, err := fs.walkExistingLocked(ctx, rp)
fs.processDeferredDecRefsLocked(ctx)
if err != nil {
@@ -686,7 +690,8 @@ func (fs *Filesystem) RmdirAt(ctx context.Context, rp *vfs.ResolvingPath) error
if err := virtfs.PrepareDeleteDentry(mntns, vfsd); err != nil {
return err
}
- if err := parentDentry.inode.RmDir(ctx, rp.Component(), vfsd); err != nil {
+
+ if err := parentDentry.inode.RmDir(ctx, name, vfsd); err != nil {
virtfs.AbortDeleteDentry(vfsd)
return err
}
@@ -765,6 +770,10 @@ func (fs *Filesystem) SymlinkAt(ctx context.Context, rp *vfs.ResolvingPath, targ
func (fs *Filesystem) UnlinkAt(ctx context.Context, rp *vfs.ResolvingPath) error {
fs.mu.Lock()
defer fs.mu.Unlock()
+
+ // Store the name before walkExistingLocked as rp will be advanced past the
+ // name in the following call.
+ name := rp.Component()
vfsd, _, err := fs.walkExistingLocked(ctx, rp)
fs.processDeferredDecRefsLocked(ctx)
if err != nil {
@@ -790,7 +799,7 @@ func (fs *Filesystem) UnlinkAt(ctx context.Context, rp *vfs.ResolvingPath) error
if err := virtfs.PrepareDeleteDentry(mntns, vfsd); err != nil {
return err
}
- if err := parentDentry.inode.Unlink(ctx, rp.Component(), vfsd); err != nil {
+ if err := parentDentry.inode.Unlink(ctx, name, vfsd); err != nil {
virtfs.AbortDeleteDentry(vfsd)
return err
}
diff --git a/pkg/sentry/fsimpl/kernfs/inode_impl_util.go b/pkg/sentry/fsimpl/kernfs/inode_impl_util.go
index 74408e322..c2109cf76 100644
--- a/pkg/sentry/fsimpl/kernfs/inode_impl_util.go
+++ b/pkg/sentry/fsimpl/kernfs/inode_impl_util.go
@@ -172,7 +172,7 @@ func (InodeNoDynamicLookup) Valid(ctx context.Context) bool {
type InodeNotSymlink struct{}
// Readlink implements Inode.Readlink.
-func (InodeNotSymlink) Readlink(context.Context) (string, error) {
+func (InodeNotSymlink) Readlink(context.Context, *vfs.Mount) (string, error) {
return "", syserror.EINVAL
}
@@ -256,6 +256,13 @@ func (a *InodeAttrs) Stat(context.Context, *vfs.Filesystem, vfs.StatOptions) (li
// SetStat implements Inode.SetStat.
func (a *InodeAttrs) SetStat(ctx context.Context, fs *vfs.Filesystem, creds *auth.Credentials, opts vfs.SetStatOptions) error {
+ return a.SetInodeStat(ctx, fs, creds, opts)
+}
+
+// SetInodeStat sets the corresponding attributes from opts to InodeAttrs.
+// This function can be used by other kernfs-based filesystem implementation to
+// sets the unexported attributes into kernfs.InodeAttrs.
+func (a *InodeAttrs) SetInodeStat(ctx context.Context, fs *vfs.Filesystem, creds *auth.Credentials, opts vfs.SetStatOptions) error {
if opts.Stat.Mask == 0 {
return nil
}
diff --git a/pkg/sentry/fsimpl/kernfs/kernfs.go b/pkg/sentry/fsimpl/kernfs/kernfs.go
index 88fcd54aa..163f26ceb 100644
--- a/pkg/sentry/fsimpl/kernfs/kernfs.go
+++ b/pkg/sentry/fsimpl/kernfs/kernfs.go
@@ -60,6 +60,7 @@ import (
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
"gvisor.dev/gvisor/pkg/sentry/vfs"
"gvisor.dev/gvisor/pkg/sync"
+ "gvisor.dev/gvisor/pkg/syserror"
)
// Filesystem mostly implements vfs.FilesystemImpl for a generic in-memory
@@ -246,15 +247,15 @@ func (d *Dentry) OnZeroWatches(context.Context) {}
// Precondition: d must represent a directory inode.
func (d *Dentry) InsertChild(name string, child *Dentry) {
d.dirMu.Lock()
- d.insertChildLocked(name, child)
+ d.InsertChildLocked(name, child)
d.dirMu.Unlock()
}
-// insertChildLocked is equivalent to InsertChild, with additional
+// InsertChildLocked is equivalent to InsertChild, with additional
// preconditions.
//
// Precondition: d.dirMu must be locked.
-func (d *Dentry) insertChildLocked(name string, child *Dentry) {
+func (d *Dentry) InsertChildLocked(name string, child *Dentry) {
if !d.isDir() {
panic(fmt.Sprintf("InsertChild called on non-directory Dentry: %+v.", d))
}
@@ -267,6 +268,36 @@ func (d *Dentry) insertChildLocked(name string, child *Dentry) {
d.children[name] = child
}
+// RemoveChild removes child from the vfs dentry cache. This does not update the
+// directory inode or modify the inode to be unlinked. So calling this on its own
+// isn't sufficient to remove a child from a directory.
+//
+// Precondition: d must represent a directory inode.
+func (d *Dentry) RemoveChild(name string, child *vfs.Dentry) error {
+ d.dirMu.Lock()
+ defer d.dirMu.Unlock()
+ return d.RemoveChildLocked(name, child)
+}
+
+// RemoveChildLocked is equivalent to RemoveChild, with additional
+// preconditions.
+//
+// Precondition: d.dirMu must be locked.
+func (d *Dentry) RemoveChildLocked(name string, child *vfs.Dentry) error {
+ if !d.isDir() {
+ panic(fmt.Sprintf("RemoveChild called on non-directory Dentry: %+v.", d))
+ }
+ c, ok := d.children[name]
+ if !ok {
+ return syserror.ENOENT
+ }
+ if &c.vfsd != child {
+ panic(fmt.Sprintf("Dentry hashed into inode doesn't match what vfs thinks! Child: %+v, vfs: %+v", c, child))
+ }
+ delete(d.children, name)
+ return nil
+}
+
// Inode returns the dentry's inode.
func (d *Dentry) Inode() Inode {
return d.inode
@@ -425,7 +456,7 @@ type inodeDynamicLookup interface {
Valid(ctx context.Context) bool
// IterDirents is used to iterate over dynamically created entries. It invokes
- // cb on each entry in the directory represented by the FileDescription.
+ // cb on each entry in the directory represented by the Inode.
// 'offset' is the offset for the entire IterDirents call, which may include
// results from the caller (e.g. "." and ".."). 'relOffset' is the offset
// inside the entries returned by this IterDirents invocation. In other words,
@@ -437,7 +468,7 @@ type inodeDynamicLookup interface {
type inodeSymlink interface {
// Readlink returns the target of a symbolic link. If an inode is not a
// symlink, the implementation should return EINVAL.
- Readlink(ctx context.Context) (string, error)
+ Readlink(ctx context.Context, mnt *vfs.Mount) (string, error)
// Getlink returns the target of a symbolic link, as used by path
// resolution:
diff --git a/pkg/sentry/fsimpl/kernfs/symlink.go b/pkg/sentry/fsimpl/kernfs/symlink.go
index 64731a3e4..a9812fcef 100644
--- a/pkg/sentry/fsimpl/kernfs/symlink.go
+++ b/pkg/sentry/fsimpl/kernfs/symlink.go
@@ -52,7 +52,7 @@ func (s *StaticSymlink) Init(creds *auth.Credentials, devMajor uint32, devMinor
}
// Readlink implements Inode.
-func (s *StaticSymlink) Readlink(_ context.Context) (string, error) {
+func (s *StaticSymlink) Readlink(_ context.Context, _ *vfs.Mount) (string, error) {
return s.target, nil
}