Linux 5.17 commit torvalds/linux@5dfbfe71e enables "the idmapping
infrastructure to support idmapped mounts of filesystems mounted
with an idmapping". Update the OpenZFS accordingly to improve the
idmapped mount support.
This pull request contains the following changes:
- xattr setter functions are fixed to take mnt_ns argument. Without
this, cp -p would fail for an idmapped mount in a user namespace.
- idmap_util is enhanced/fixed for its use in a user ns context.
- One test case added to test idmapped mount in a user ns.
Reviewed-by: Christian Brauner <christian@brauner.io>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Youzhong Yang <yyang@mathworks.com>
Closes#14097
2a068a1394 introduced 2 new defect
reports from Coverity and 1 from Clang's static analyzer.
Coverity complained about a potential resource leak from only calling
`close(fd)` when `fd > 0` because `fd` might be `0`. This is a false
positive, but rather than dismiss it as such, we can change the
comparison to ensure that this never appears again from any static
analyzer. Upon inspection, 6 more instances of this were found in the
file, so those were changed too. Unfortunately, since the file
descriptor has been put into an unsigned variable in `attr.userns_fd`,
we cannot do a non-negative check on it to see if it has not been
allocated, so we instead restructure the error handling to avoid the
need for a check. This also means that errors had not been handled
correctly here, so the static analyzer found a bug (although practically
by accident).
Coverity also complained about a dereference before a NULL check in
`do_idmap_mount()` on `source`. Upon inspection, it appears that the
pointer is never NULL, so we delete the NULL check as cleanup.
Clang's static analyzer complained that the return value of
`write_pid_idmaps()` can be uninitialized if we have no idmaps to write.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Youzhong Yang <yyang@mathworks.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14061
The ifdef used would never work because the CPP is not aware of C
structure definitions. Rather than use an autotools check, we can just
use a nameless structure that we typedef to mount_attr_t. This is a
Linux kernel interface, which means that it is stable and this is fine
to do.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Youzhong Yang <yyang@mathworks.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14057Closes#14058
Adds support for idmapped mounts. Supported as of Linux 5.12 this
functionality allows user and group IDs to be remapped without changing
their state on disk. This can be useful for portable home directories
and a variety of container related use cases.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Youzhong Yang <yyang@mathworks.com>
Closes#12923Closes#13671
