Commit Graph

7 Commits

Author SHA1 Message Date
Ryan Moeller fde66e583d FreeBSD: libspl: Add locking around statfs globals
Makes getmntent and getmntany thread-safe for external consumers of
libzfs zpool_disable_datasets, zfs_iter_mounted, libzfs_mnttab_update,
libzfs_mnttab_find.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <freqlabs@FreeBSD.org>
Closes #13484
2022-05-27 09:19:37 -07:00
Ryan Moeller f4def7ec6c FreeBSD: Fix leaked strings in libspl mnttab
The FreeBSD implementations of various libspl functions for getting
mounted device information were found to leak several strings which
were being allocated in statfs2mnttab but never freed.

The Solaris getmntany(3C) and related interfaces are expected to return
strings residing in static buffers that need to be copied rather than
freed by the caller.

Use static thread-local storage to stash the mnttab structure strings
from FreeBSD's statfs info rather than strings allocated on the heap by
strdup(3).

While here, remove some stray commented out lines.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Rich Ercolani <rincebrain@gmail.com>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #12961
2022-02-03 15:28:01 -08:00
Alan Somers 2c3d7283b4 libzfs: On FreeBSD, use MNT_NOWAIT with getfsstat
`getfsstat(2)` is used to retrieve the list of mounted file systems,
which libzfs uses when fetching properties like mountpoint, atime,
setuid, etc.  The `mode` parameter may be `MNT_NOWAIT`, which uses
information in the VFS's cache, or `MNT_WAIT`, which effectively does a
`statfs` on every single mounted file system in order to fetch the most
up-to-date information.  As far as I can tell, the only fields that
libzfs cares about are the filesystem's name, mountpoint, fstypename,
and mount flags.  Those things are always updated on mount and unmount,
so they will always be accurate in the VFS's mount cache except in two
circumstances:

1) When a file system is busy unmounting
2) When a ZFS file system changes the value of a mount-overridable
   property like atime or setuid, but doesn't remount the file system.
   Right now that only happens when the property is changed by an
   unprivileged user who has delegated authority to change the property
   but not to mount the dataset.  But perhaps libzfs could choose to do
   it for other reasons in the future.

Switching to `MNT_NOWAIT` will greatly improve speed with no downside,
as long as we explicitly update the mount cache whenever we change a
mount-overridable property.

For comparison, Illumos gets this information using the native
`getmntany` and `getmntent` functions, which also use cached
information.  The illumos function that would refresh the cache,
`resetmnttab`, is never called by libzfs.

And on GNU/Linux, `getmntany` and `getmntent` don't even communicate
with the kernel directly.  They simply parse the file they are given,
which is usually /etc/mtab or /proc/mounts.  Perhaps the implementation
of /proc/mounts is synchronous, ala MNT_WAIT; I don't know.

Sponsored-by:	Axcient
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by:	Alan Somers <asomers@gmail.com>
Closes: #12091
2021-06-09 13:05:34 -07:00
Ryan Moeller e191b60ddc
FreeBSD: Improve libzfs_error_init messages
It is a common mistake to have failed to autoload the module due to
permission issues when running a ZFS command as a user.  "Operation
not permitted" is an unhelpfully vague error message.

Use a thread-local message buffer to format a nicer error message.
We can infer that loading the kernel module failed if the module is
not loaded.  This can be extended with heuristics for other errors
in the future.

While looking at this stuff, remove an unused thread-local message
buffer found in libspl and remove some inaccurate verbiage from the
comment on libzfs_load_module.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #11033
2020-10-13 09:38:40 -07:00
Ryan Moeller 46b7d53baf libspl: Provide platform-specific zone implementations
FreeBSD has the concept of jails, a precursor to Solaris's zones, which
can be mapped to the required zones interface with relative ease.  The
previous ZFS implementation in FreeBSD did so, and we should continue
to provide an appropriate implementation in OpenZFS as well.

Move lib/libspl/zone.c into platform code and adopt the correct
implementation for FreeBSD.

While here, prune unused code.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <freqlabs@FreeBSD.org>
Closes #10851
2020-08-31 19:43:30 -07:00
Arvind Sankar 60356b1a21 Add include files for prototypes
Include the header with prototypes in the file that provides definitions
as well, to catch any mismatch between prototype and definition.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Closes #10470
2020-06-18 12:21:25 -07:00
Matthew Macy 9f0a21e641
Add FreeBSD support to OpenZFS
Add the FreeBSD platform code to the OpenZFS repository.  As of this
commit the source can be compiled and tested on FreeBSD 11 and 12.
Subsequent commits are now required to compile on FreeBSD and Linux.
Additionally, they must pass the ZFS Test Suite on FreeBSD which is
being run by the CI.  As of this commit 1230 tests pass on FreeBSD
and there are no unexpected failures.

Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #898 
Closes #8987
2020-04-14 11:36:28 -07:00