diff options
Diffstat (limited to 'pkg/sentry/fsimpl/tmpfs/tmpfs.go')
| -rw-r--r-- | pkg/sentry/fsimpl/tmpfs/tmpfs.go | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/pkg/sentry/fsimpl/tmpfs/tmpfs.go b/pkg/sentry/fsimpl/tmpfs/tmpfs.go index 428f62aaa..a7fdf19ca 100644 --- a/pkg/sentry/fsimpl/tmpfs/tmpfs.go +++ b/pkg/sentry/fsimpl/tmpfs/tmpfs.go @@ -201,6 +201,25 @@ func (fs *filesystem) Release(ctx context.Context) { fs.vfsfs.VirtualFilesystem().PutAnonBlockDevMinor(fs.devMinor) } +// immutable +var globalStatfs = linux.Statfs{ + Type: linux.TMPFS_MAGIC, + BlockSize: usermem.PageSize, + FragmentSize: usermem.PageSize, + NameLength: linux.NAME_MAX, + + // tmpfs currently does not support configurable size limits. In Linux, + // such a tmpfs mount will return f_blocks == f_bfree == f_bavail == 0 from + // statfs(2). However, many applications treat this as having a size limit + // of 0. To work around this, claim to have a very large but non-zero size, + // chosen to ensure that BlockSize * Blocks does not overflow int64 (which + // applications may also handle incorrectly). + // TODO(b/29637826): allow configuring a tmpfs size and enforce it. + Blocks: math.MaxInt64 / usermem.PageSize, + BlocksFree: math.MaxInt64 / usermem.PageSize, + BlocksAvailable: math.MaxInt64 / usermem.PageSize, +} + // dentry implements vfs.DentryImpl. type dentry struct { vfsd vfs.Dentry @@ -698,6 +717,11 @@ func (fd *fileDescription) SetStat(ctx context.Context, opts vfs.SetStatOptions) return nil } +// StatFS implements vfs.FileDescriptionImpl.StatFS. +func (fd *fileDescription) StatFS(ctx context.Context) (linux.Statfs, error) { + return globalStatfs, nil +} + // Listxattr implements vfs.FileDescriptionImpl.Listxattr. func (fd *fileDescription) Listxattr(ctx context.Context, size uint64) ([]string, error) { return fd.inode().listxattr(size) |