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Diffstat (limited to 'pkg/sentry/fs/ext/filesystem.go')
| -rw-r--r-- | pkg/sentry/fs/ext/filesystem.go | 137 |
1 files changed, 0 insertions, 137 deletions
diff --git a/pkg/sentry/fs/ext/filesystem.go b/pkg/sentry/fs/ext/filesystem.go deleted file mode 100644 index 7150e75a5..000000000 --- a/pkg/sentry/fs/ext/filesystem.go +++ /dev/null @@ -1,137 +0,0 @@ -// Copyright 2019 The gVisor Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// http://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -package ext - -import ( - "io" - "sync" - - "gvisor.dev/gvisor/pkg/sentry/context" - "gvisor.dev/gvisor/pkg/sentry/fs/ext/disklayout" - "gvisor.dev/gvisor/pkg/sentry/vfs" - "gvisor.dev/gvisor/pkg/syserror" -) - -// filesystem implements vfs.FilesystemImpl. -type filesystem struct { - // TODO(b/134676337): Remove when all methods have been implemented. - vfs.FilesystemImpl - - vfsfs vfs.Filesystem - - // mu serializes changes to the Dentry tree and the usage of the read seeker. - mu sync.Mutex - - // dev is the ReadSeeker for the underlying fs device. It is protected by mu. - // - // The ext filesystems aim to maximize locality, i.e. place all the data - // blocks of a file close together. On a spinning disk, locality reduces the - // amount of movement of the head hence speeding up IO operations. On an SSD - // there are no moving parts but locality increases the size of each transer - // request. Hence, having mutual exclusion on the read seeker while reading a - // file *should* help in achieving the intended performance gains. - // - // Note: This synchronization was not coupled with the ReadSeeker itself - // because we want to synchronize across read/seek operations for the - // performance gains mentioned above. Helps enforcing one-file-at-a-time IO. - dev io.ReadSeeker - - // inodeCache maps absolute inode numbers to the corresponding Inode struct. - // Inodes should be removed from this once their reference count hits 0. - // - // Protected by mu because every addition and removal from this corresponds to - // a change in the dentry tree. - inodeCache map[uint32]*inode - - // sb represents the filesystem superblock. Immutable after initialization. - sb disklayout.SuperBlock - - // bgs represents all the block group descriptors for the filesystem. - // Immutable after initialization. - bgs []disklayout.BlockGroup -} - -// Compiles only if filesystem implements vfs.FilesystemImpl. -var _ vfs.FilesystemImpl = (*filesystem)(nil) - -// getOrCreateInode gets the inode corresponding to the inode number passed in. -// It creates a new one with the given inode number if one does not exist. -// -// Preconditions: must be holding fs.mu. -func (fs *filesystem) getOrCreateInode(inodeNum uint32) (*inode, error) { - if in, ok := fs.inodeCache[inodeNum]; ok { - return in, nil - } - - in, err := newInode(fs.dev, fs.sb, fs.bgs, inodeNum) - if err != nil { - return nil, err - } - - fs.inodeCache[inodeNum] = in - return in, nil -} - -// Release implements vfs.FilesystemImpl.Release. -func (fs *filesystem) Release() { -} - -// Sync implements vfs.FilesystemImpl.Sync. -func (fs *filesystem) Sync(ctx context.Context) error { - // This is a readonly filesystem for now. - return nil -} - -// The vfs.FilesystemImpl functions below return EROFS because their respective -// man pages say that EROFS must be returned if the path resolves to a file on -// a read-only filesystem. - -// TODO(b/134676337): Implement path traversal and return EROFS only if the -// path resolves to a Dentry within ext fs. - -// MkdirAt implements vfs.FilesystemImpl.MkdirAt. -func (fs *filesystem) MkdirAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.MkdirOptions) error { - return syserror.EROFS -} - -// MknodAt implements vfs.FilesystemImpl.MknodAt. -func (fs *filesystem) MknodAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.MknodOptions) error { - return syserror.EROFS -} - -// RenameAt implements vfs.FilesystemImpl.RenameAt. -func (fs *filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, vd vfs.VirtualDentry, opts vfs.RenameOptions) error { - return syserror.EROFS -} - -// RmdirAt implements vfs.FilesystemImpl.RmdirAt. -func (fs *filesystem) RmdirAt(ctx context.Context, rp *vfs.ResolvingPath) error { - return syserror.EROFS -} - -// SetStatAt implements vfs.FilesystemImpl.SetStatAt. -func (fs *filesystem) SetStatAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.SetStatOptions) error { - return syserror.EROFS -} - -// SymlinkAt implements vfs.FilesystemImpl.SymlinkAt. -func (fs *filesystem) SymlinkAt(ctx context.Context, rp *vfs.ResolvingPath, target string) error { - return syserror.EROFS -} - -// UnlinkAt implements vfs.FilesystemImpl.UnlinkAt. -func (fs *filesystem) UnlinkAt(ctx context.Context, rp *vfs.ResolvingPath) error { - return syserror.EROFS -} |