3.5.1 Matrix Server Release Notes

PolyServe Release Notes 25

Operating System and Environment Issues

Defect

Description

455 Parent dentries are not revalidated

During path lookups, the operating system does not revalidate

parent dentries when they are specified as ʺ..ʺ components. The

operating system assumes that the parent dentry associated

with ʺ..ʺ is always valid; however, this is not always the case in a

distributed environment.

For example, server A may have a process that executes cd

/a/b/c. Server B has a process that renames /a/b/c to a/c and

removes directory b. If the process on server A executes cd .., it

will be allowed to change directory into directory b, which no

longer exists. Any operations that attempt to modify the

contents of directory b will fail with the appropriate error.

To get out of directory b, you will need to either execute another

cd .. command or change directory using an absolute pathname.

701 Problem with unmounting filesystems on the same

mountpoint

Linux allows two filesystems to be mounted on the same

mountpoint. The second filesystem to be mounted hides the first

filesystem. If you attempt to unmount the first filesystem, the

second filesystem will be unmounted because the first

filesystem is not visible to the operating system. This problem

can occur with any type of filesystem.

To avoid the problem, do not mount two filesystems on the

same mountpoint, or unmount the second filesystem and then

unmount the first filesystem.