Only generate a warning if there is something to report.
Signed-off-by: NMarc Hartmayer <mhartmay@linux.vnet.ibm.com>
Reviewed-by: NBjoern Walk <bwalk@linux.vnet.ibm.com>
Reviewed-by: NBoris Fiuczynski <fiuczy@linux.vnet.ibm.com>

Prefer virDirOpen.

A helper function that does not report any errors.

Just like virDirOpen, but it returns 0 without reporting an error
on ENOENT.

Switch from opendir to virDirOpen everywhere we need to report an error.

A helper that calls opendir and reports an error if it fails.

It skips those directory entries.

All of the callers either skip these explicitly, skip all entries
starting with a dot or match the entry name against stricter patterns.

Introduce a helper that only calls closedir if DIR* is non-NULL
and sets it to NULL afterwards.

s/succcess/success
Signed-off-by: NChen Hanxiao <chenhanxiao@gmail.com>

Move some parts of virStorageFileRemoveLastPathComponent
into a separate function so they can be reused.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Signed-off-by: NNikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>

This an ubuntu/debian packaging convention. At one point it may have
been an actually different binary, but at least as of ubuntu precise
(the oldest supported ubuntu distro, released april 2012) kvm-img is
just a symlink to qemu-img for back compat.

I think it's safe to drop support for it

The implementation is pretty straightforward. Moreover, because
of the nature of things, gethostbyname_r and gethostbyname2_r can
be implemented at the same time too.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

NFS with root-squash is the only reason we need to do setuid/setgid
crazyness in virFileRemove, so limit that behavior to the NFS case.

Break these checks out into their own function, and clearly document
each one. This shouldn't change behavior

VIR_DEBUG and VIR_WARN will automatically add a new line to the message,
having "\n" at the end or at the beginning of the message results in
empty lines.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

We have macros for both positive and negative string matching.
Therefore there is no need to use !STREQ or !STRNEQ. At the same
time as we are dropping this, new syntax-check rule is
introduced to make sure we won't introduce it again.
Signed-off-by: NIshmanpreet Kaur Khera <khera.ishman@gmail.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

After a successful creation of a directory, if some other call results
in returning a failure, let's remove the directory we created to
prevent another round trip or confusion in the caller. In particular, this
function can be called during a storage backend buildVol, so in order
to ensure that caller doesn't need to distinguish between failed create
or some other failure after create, just remove the directory we created.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

After a successful creation of a file, if some other call results
in returning a failure, let's unlink the file we created to prevent
another round trip or confusion in the caller. In particular, this
function can be called during a storage backend buildVol, so in order
to ensure that caller doesn't need to distinguish between failed create
or some other failure after create, just remove the volume we created.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

As it turns out the caller in this case expects a return < 0 for failure
and to get/use "errno" rather than using the negative of returned status.
Again different than the create path.

If someone "deleted" a file from the pool without using virsh vol-delete,
then the unlink/rmdir would return an error (-1) and set errno to ENOENT.
The caller checks errno for ENOENT when determining whether to throw an
error message indicating the failure.  Without the change, the error
message is:

error: Failed to delete vol $vol
error: cannot unlink file '/$pathto/$vol': Success

This patch thus allows the fork path to follow the non-fork path
where unlink/rmdir return -1 and errno.

Unlike create options, if the file to be removed is already in the
pool, then the uid/gid will come from the pool. If it's the same as the
currently running process, then just do the unlink/rmdir directly
rather than going through the fork processing unnecessarily

Rather than inlining the code, use the common API.

Rather than inlining the code, use the common API.

Rather than inlining the code, use the common API

Similar to commit id '35847860', it's possible to attempt to create
a 'netfs' directory in an NFS root-squash environment which will cause
the 'vol-delete' command to fail.  It's also possible error paths from
the 'vol-create' would result in an error to remove a created directory
if the permissions were incorrect (and disallowed root access).

Thus rename the virFileUnlink to be virFileRemove to match the C API
functionality, adjust the code to following using rmdir or unlink
depending on the path type, and then use/call it for the VIR_STORAGE_VOL_DIR

Commit id 'f1f68ca3' added code to remove the directory paths for
auto-generated sockets, but that code could be called before the
paths were created resulting in generating error messages from
virFileDeleteTree indicating that the file doesn't exist.

Rather than "enforce" all callers to make the non-NULL and existence
checks, modify the virFileDeleteTree API to silently ignore NULL on
input and non-existent directory trees.

Commit 35847860 Added the virFileUnlink function, but failed to add
a version for mingw build, causing the following error:

  Cannot export virFileUnlink: symbol not defined
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

In virFileNBDDeviceFindUnused if virFileNBDDeviceIsBusy returns 0,
then both branches jumped to cleanup, so just use ignore_value
since the function returns NULL or some memory and the caller
handles the error.

In an NFS root-squashed environment the 'vol-delete' command will fail to
'unlink' the target volume since it was created under a different uid:gid.

This code continues the concepts introduced in virFileOpenForked and
virDirCreate[NoFork] with respect to running the unlink command under
the uid/gid of the child. Unlike the other two, don't retry on EACCES
(that's why we're here doing this now).

This will only be seen when debugging, but in order to help determine
whether a virFileOpenForceOwnerMode failed during an NFS root-squash
volume/file creation, add an error message from the child.

So far qemu-nbd is run even if the nbd kernel module isn't loaded. This
leads to errors when the user starts his lxc container while libvirt
could easily load the nbd module automatically.

This happens if user requires creation of a directory with specified
UID/GID permissions. To accomplish this, we use fork approach and
set particular UID/GID permissions in child process. However, child
process doesn't have a valid descriptor to a logfile (this is prohibited
explicitly) and since parent process doesn't handle negative exit codes from
child in any way, 'uknown cause' error is returned to the user.

Commit 92d9114e tweaked the way we handle child errors when using fork
approach to set specific permissions (features originally introduced
by 98f6f381). The same logic should be used to create directories with
specified permissions as well.

https://bugzilla.redhat.com/show_bug.cgi?id=1230137

Previous patch of this series proposed a fix to virDirCreate, so that parent
process reports an error if child process failed its task.
However our logic still permits the child to exit with negative errno followed
by a check of the status on the parent side using WEXITSTATUS which, being
POSIX compliant, takes the lower 8 bits of the exit code and returns is to
the caller. However, by taking 8 bits from a negative exit code
(two's complement) the status value we read and append to stream is
'2^8 - abs(original exit code)' which doesn't quite reflect the real cause when
compared to the meaning of errno values.

Only set directory permissions at pool build time, if:

- User explicitly requested a mode via the XML
- The directory needs to be created
- We need to do the crazy NFS root-squash workaround

This allows qemu:///session to call build on an existing directory
like /tmp.

The only two virDirCreate callers already use it

I screwed this up in the previous (post 1.2.16) commits

Currently we try to chown any directory passed to virDirCreate,
even if the user didn't request any explicit owner/group via the
pool/vol XML.

This causes issues with qemu:///session: try to build a pool of
a root owned directory like /tmp, and it fails trying to chown the
directory to the session user. Instead it should just leave things
as they are, unless the user requests changing permissions via
the pool XML.

Similarly this is annoying if creating a storage pool via system
libvirtd of an existing directory in user $HOME, it's now owned
by root.

The virDirCreate function is pretty convoluted, since it needs to
fork off in certain specific cases. Try to document that, to make
it clear where exactly we are changing behavior.