-1 was used everywhere, but -EBADF or -EBADFD started being used in various
places. Let's make things consistent in the new style.
Note that there are two candidates:
EBADF 9 Bad file descriptor
EBADFD 77 File descriptor in bad state
Since we're initializating the fd, we're just assigning a value that means
"no fd yet", so it's just a bad file descriptor, and the first errno fits
better. If instead we had a valid file descriptor that became invalid because
of some operation or state change, the other errno would fit better.
In some places, initialization is dropped if unnecessary.
If the flag is set, we mount /tmp/ in a way that is suitable for generators and
other quick jobs.
Unfortunately I had to move some code from shared/mount-util.c to
basic/mountpoint-util.c. The functions that are moved are very thin wrappers
around mount(2), so this doesn't actually change much in the code split between
libbasic and libshared.
Implications for the host would be weird if a private mount namespace is not
used, so assert on FORK_NEW_MOUNTNS when the flag is used.
This reverts commit 7d4f00c88c.
fstype_can_uid_gid() is about fixating all files to the specified
uid/gid. tmpfs does not qualify. The uid/gid parameter there is simply
about the default uid/gid for the root inode of the tmpfs, it allows
setting uids/gid arbirarily for all inodes after that.
This distinction matters: for file systems this function returns true
for we can use this in place of uidmapped mounts. But for tmpfs this is
not going to work, given inodes on that fs can end up having arbitrary
uid/gid.
See: https://github.com/systemd/systemd/pull/25284#issue-1438427144
As tmpfs(5) says, both uid= and gid= are supported since kernel 2.5.7 and
the mount utility seems to agree:
```
# stat -c "%U:%G" mnt
root:root
# mount -o uid=testuser,gid=testuser -t tmpfs tmpfs mnt
# stat -c "%U:%G" mnt
testuser:testuser
```
However, systemd-mount currently complains:
```
# systemd-mount --owner testuser -t tmpfs tmpfs mnt
File system type tmpfs is not known to support uid=/gid=, refusing.
```
Inspired by: https://github.com/systemd/systemd/pull/24141
Calling fd_is_mountpoint() with AT_EMPTYPATH and an empty filename can
only work if we have new statx() available. If we do not, we can still
make things work for directories, but not for other inodes (since there
we cannot query information about the parent inode to compare things.)
Hence, let's handle and test this explicitly, to support this to the
level this is possible.
Let's define two helpers strdupa_safe() + strndupa_safe() which do the
same as their non-safe counterparts, except that they abort if called
with allocations larger than ALLOCA_MAX.
This should ensure that all our alloca() based allocations are subject
to this limit.
afaics glibc offers three alloca() based APIs: alloca() itself,
strndupa() + strdupa(). With this we have now replacements for all of
them, that take the limit into account.
The second call to name_to_handle_at_loop() didn't check for the specific
errors that can happen when the parent dir is mounted by nfs and instead of
falling back like it's done for the child dir, fd_is_mount_point() failed in
this case.
The various flavours of stat() basically tell us for free if something
is a symlink. If it is, then it's definitely not a mount point. Use
that.
All other inode types can be mount point, just symlinks cannot.
Wherever we read virtual files we better should use
read_full_virtual_file(), to make sure we get a consistent response
given how weird the kernel's handling with partial read on such file
systems is.
So the currentl and only fd_is_mount_point() check is actually entirely
bogus: it passes "/" as filename argument, but that's not actually a
a valid filename, but an absolute path.
fd_is_mount_point() is written in a way tha the fd refers to a directory
and the specified path is a file directly below it that shall be
checked. The test call actually violated that rule, but still expected
success.
Let's fix this, and check for this explicitly, and refuse it.
Let's extend the test and move it to test-mountpoint-util.c where the
rest of the tests for related calls are placed.
Replaces: #18004Fixes: #17950
Similarly to "setup" vs. "set up", "fallback" is a noun, and "fall back"
is the verb. (This is pretty clear when we construct a sentence in the
present continous: "we are falling back" not "we are fallbacking").
The kernel finally has a proper API to determine the mnt_id of a file.
Let's use it.
This adds support for the STATX_MNT_ID field of statx(), added in
kernel 5.8.
chase_symlinks() would return negative on error, and either a non-negative status
or a non-negative fd when CHASE_OPEN was given. This made the interface quite
complicated, because dependning on the flags used, we would get two different
"types" of return object. Coverity was always confused by this, and flagged
every use of chase_symlinks() without CHASE_OPEN as a resource leak (because it
would this that an fd is returned). This patch uses a saparate output parameter,
so there is no confusion.
(I think it is OK to have functions which return either an error or an fd. It's
only returning *either* an fd or a non-fd that is confusing.)
Currently systemd will treat smb3 as local filesystem and cause
can't boot failures. Add smb3 to the list of remote filesystems
to fix this issue.
Signed-off-by: Kenneth D'souza <kdsouza@redhat.com>
This is partially a refactoring, but also makes many more places use
unlocked operations implicitly, i.e. all users of fopen_temporary().
AFAICT, the uses are always for short-lived files which are not shared
externally, and are just used within the same context. Locking is not
necessary.
Zbigniew Jędrzejewski-Szmek
Yu Watanabe
David Tardon
Frantisek Sumsal
Thomas Blume
Lennart Poettering
Luca Boccassi
Iago López Galeiras
Franck Bui
Luca Boccassi
YmrDtnJu
pelzvieh
Jonas Jelten
Kenneth D'souza
Mike Gilbert