`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
Exporting names this short can easily cause nasty collisions with user code.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#12050
Fixes get_system_hostid() if it was set via the aforementioned sysctl
and simplifies the code a bit. The kernel and user-space must agree,
after all.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#11879
Merge the actual implementations of getexecname() and slightly clean
up the FreeBSD one.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#11879
All users did a freopen() on it. Even some non-users did!
This is point-less ‒ just open the mtab when needed
If I understand Solaris' getextmntent(3C) correctly, the non-user
freopen()s are very likely an odd, twisted vestigial tail of that ‒
but it's got a completely different calling convention and caching
semantics than any platform we support
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#11868
As found by
git grep -E '(open|setmntent|pipe2?)\(' |
grep -vE '((zfs|zpool)_|fd|dl|lzc_re|pidfile_|g_)open\('
FreeBSD's pidfile_open() says nothing about the flags of the files it
opens, but we can't do anything about it anyway; the implementation does
open all files with O_CLOEXEC
Consider this output with zpool.d/media appended with
"pid=$$; (ls -l /proc/$pid/fd > /dev/tty)":
$ /sbin/zpool iostat -vc media
lrwx------ 0 -> /dev/pts/0
l-wx------ 1 -> 'pipe:[3278500]'
l-wx------ 2 -> /dev/null
lrwx------ 3 -> /dev/zfs
lr-x------ 4 -> /proc/31895/mounts
lrwx------ 5 -> /dev/zfs
lr-x------ 10 -> /usr/lib/zfs-linux/zpool.d/media
vs
$ ./zpool iostat -vc vendor,upath,iostat,media
lrwx------ 0 -> /dev/pts/0
l-wx------ 1 -> 'pipe:[3279887]'
l-wx------ 2 -> /dev/null
lr-x------ 10 -> /usr/lib/zfs-linux/zpool.d/media
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#11866
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
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
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
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#898Closes#8987
Factor Linux specific pieces out of libspl.
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes#9336
