diff options
Diffstat (limited to 'pkg/sentry/fs/ext/utils.go')
| -rw-r--r-- | pkg/sentry/fs/ext/utils.go | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/pkg/sentry/fs/ext/utils.go b/pkg/sentry/fs/ext/utils.go index 861ef9a73..71e46b2c4 100644 --- a/pkg/sentry/fs/ext/utils.go +++ b/pkg/sentry/fs/ext/utils.go @@ -27,6 +27,8 @@ import ( // // All disk reads should use this helper so we avoid reading from stale // previously used offsets. This function forces the offset parameter. +// +// Precondition: Must have mutual exclusion on device fd. func readFromDisk(dev io.ReadSeeker, abOff int64, v interface{}) error { if _, err := dev.Seek(abOff, io.SeekStart); err != nil { return syserror.EIO @@ -42,6 +44,8 @@ func readFromDisk(dev io.ReadSeeker, abOff int64, v interface{}) error { // readSuperBlock reads the SuperBlock from block group 0 in the underlying // device. There are three versions of the superblock. This function identifies // and returns the correct version. +// +// Precondition: Must have mutual exclusion on device fd. func readSuperBlock(dev io.ReadSeeker) (disklayout.SuperBlock, error) { var sb disklayout.SuperBlock = &disklayout.SuperBlockOld{} if err := readFromDisk(dev, disklayout.SbOffset, sb); err != nil { @@ -82,6 +86,8 @@ func blockGroupsCount(sb disklayout.SuperBlock) uint64 { // readBlockGroups reads the block group descriptor table from block group 0 in // the underlying device. +// +// Precondition: Must have mutual exclusion on device fd. func readBlockGroups(dev io.ReadSeeker, sb disklayout.SuperBlock) ([]disklayout.BlockGroup, error) { bgCount := blockGroupsCount(sb) bgdSize := uint64(sb.BgDescSize()) |