Commit Graph

61 Commits

Author SHA1 Message Date
Paolo Bonzini
40fc85e796 util: add virFileReadHeaderQuiet wrapper around virFileReadHeaderFD
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
2018-01-04 16:52:03 +01:00
Andrea Bolognani
3e7db8d3e8 Remove backslash alignment attempts
Right-aligning backslashes when defining macros or using complex
commands in Makefiles looks cute, but as soon as any changes is
required to the code you end up with either distractingly broken
alignment or unnecessarily big diffs where most of the changes
are just pushing all backslashes a few characters to one side.

Generated using

  $ git grep -El '[[:blank:]][[:blank:]]\\$' | \
    grep -E '*\.([chx]|am|mk)$$' | \
    while read f; do \
      sed -Ei 's/[[:blank:]]*[[:blank:]]\\$/ \\/g' "$f"; \
    done

Signed-off-by: Andrea Bolognani <abologna@redhat.com>
2017-11-03 13:24:12 +01:00
Erik Skultety
caf26412b6 util: Introduce virFileWaitForExists
Since we have a number of places where we workaround timing issues with
devices, attributes (files in general) not being available at the time
of processing them by calling usleep in a loop for a fixed number of
tries, we could as well have a utility function that would do that.
Therefore we won't have to duplicate this ugly workaround even more.

Signed-off-by: Erik Skultety <eskultet@redhat.com>
2017-10-19 08:54:53 +02:00
Ján Tomko
5463d95969 use virFileAllocate in virStorageFileResize
Introduce a new function virFileAllocate that will call the
non-destructive variants of safezero, essentially reverting
my commit 1390c268
    safezero: fall back to writing zeroes even when resizing
back to the state as of commit 18f0316
    virstoragefile: Have virStorageFileResize use safezero

This means that _ALLOCATE flag will no longer work on platforms
without the allocate syscalls, but it will not overwrite data
either.
2017-09-27 14:40:44 +02:00
Daniel P. Berrange
407a281a8e Revert "Prevent more compiler optimization of mockable functions"
This reverts commit e4b980c853.

When a binary links against a .a archive (as opposed to a shared library),
any symbols which are marked as 'weak' get silently dropped. As a result
when the binary later runs, those 'weak' functions have an address of
0x0 and thus crash when run.

This happened with virtlogd and virtlockd because they don't link to
libvirt.so, but instead just libvirt_util.a and libvirt_rpc.a. The
virRandomBits symbols was weak and so left out of the virtlogd &
virtlockd binaries, despite being required by virHashTable functions.

Various other binaries like libvirt_lxc, libvirt_iohelper, etc also
link directly to .a files instead of libvirt.so, so are potentially
at risk of dropping symbols leading to a later runtime crash.

This is normal linker behaviour because a weak symbol is not treated
as undefined, so nothing forces it to be pulled in from the .a You
have to force the linker to pull in weak symbols using -u$SYMNAME
which is not a practical approach.

This risk is silent bad linkage that affects runtime behaviour is
not acceptable for a fix that was merely trying to fix the test
suite. So stop using __weak__ again.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-07-13 13:07:06 +01:00
Daniel P. Berrange
e4b980c853 Prevent more compiler optimization of mockable functions
Currently all mockable functions are annotated with the 'noinline'
attribute. This is insufficient to guarantee that a function can
be reliably mocked with an LD_PRELOAD. The C language spec allows
the compiler to assume there is only a single implementation of
each function. It can thus do things like propagating constant
return values into the caller at compile time, or creating
multiple specialized copies of the function body each optimized
for a different caller. To prevent these optimizations we must
also set the 'noclone' and 'weak' attributes.

This fixes the test suite when libvirt.so is built with CLang
with optimization enabled.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-07-11 13:57:12 +01:00
Michal Privoznik
b928d140f4 util: Introduce virFileInData
This function takes a FD and determines whether the current
position is in data section or in a hole. In addition to that,
it also determines how much bytes are there remaining till the
current section ends.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-05-18 07:42:13 +02:00
Martin Kletzander
7008e10869 util: Remove virsysfs and instead enhance virFileReadValue* functions
It is no longer needed thanks to the great virfilewrapper.c.  And this
way we don't have to add a new set of functions for each prefixed
path.

While on that, add two functions that weren't there before, string and
scaled integer reading ones.  Also increase the length of the string
being read by one to accompany for the optional newline at the
end (i.e. change INT_STRLEN_BOUND to INT_BUFSIZE_BOUND).

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2017-05-09 13:12:40 +02:00
Daniel P. Berrange
728cacc8ab annotate all mocked functions with noinline
CLang's optimizer is more aggressive at inlining functions than
gcc and so will often inline functions that our tests want to
mock-override. This causes the test to fail in bizarre ways.

We don't want to disable inlining completely, but we must at
least prevent inlining of mocked functions. Fortunately there
is a 'noinline' attribute that lets us control this per function.

A syntax check rule is added that parses tests/*mock.c to extract
the list of functions that are mocked (restricted to names starting
with 'vir' prefix). It then checks that src/*.h header file to
ensure it has a 'ATTRIBUTE_NOINLINE' annotation. This should prevent
use from bit-rotting in future.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-04-19 10:51:51 +01:00
Martin Kletzander
9fdd077de7 virfile: Add helpers for reading simple values
These helpers are doing just a read and covert the value, but they
properly size the read limit, handle additional whitespace characters,
and unify error reporting.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2017-03-27 13:13:29 +02:00
John Ferlan
97e0d3c3c9 util: Rename virFileWaitForDevices
The function is actually in virutil.c, but prototyped in virfile.h.
This patch fixes that by renaming the function to virWaitForDevices,
adding the prototype in virutil.h and libvirt_private.syms, and then
changing the callers to use the new name.

Signed-off-by: John Ferlan <jferlan@redhat.com>
2017-03-15 21:17:47 -04:00
Erik Skultety
875894245a util: Introduce virFileComparePaths
So rather than comparing 2 paths (strings) as they are, which can very
easily lead to unnecessary errors (e.g. in storage driver) that the paths
are not the same when in fact they'd be e.g. just symlinks to the same
location, we should put our best effort into resolving any symlinks and
canonicalizing the path and only then compare the 2 paths for equality.

Signed-off-by: Erik Skultety <eskultet@redhat.com>
2017-02-10 17:01:12 +01:00
Michal Privoznik
6094169b83 util: Introduce virFileReadLink
We will need to traverse the symlinks one step at the time.
Therefore we need to see where a symlink is pointing to.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-02-07 10:40:53 +01:00
Michal Privoznik
41816751a7 util: Introduce virFileMoveMount
This is a simple wrapper over mount(). However, not every system
out there is capable of moving a mount point. Therefore, instead
of having to deal with this fact in all the places of our code we
can have a simple wrapper and deal with this fact at just one
place.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-11 18:06:30 +01:00
Michal Privoznik
654b4d48bc virfile: Introduce ACL helpers
Namely, virFileGetACLs, virFileSetACLs, virFileFreeACLs and
virFileCopyACLs. These functions are going to be required when we
are creating /dev for qemu. We have copy anything that's in
host's /dev exactly as is. Including ACLs.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-12-15 09:25:16 +01:00
Michal Privoznik
1a7c9a5d50 virfile: Introduce virFileSetupDev
This part of code that LXC currently uses will be reused so move
to a generic function.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-12-15 09:25:16 +01:00
Michal Privoznik
b9b664c5a8 util: Introduce virFileRewriteStr
There are couple of places where we have a string and want to
save it to a file. Atomically. In all those places we use
virFileRewrite() but also implement the very same callback which
takes the string and write it into temp file. This makes no
sense. Unify the callbacks and move them to one place.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-12-06 13:33:18 +01:00
Laine Stump
e026563f01 util: new function virFileLength()
This new function just calls fstat() (if provided with a valid fd) or
stat() (if fd is -1) and returns st_size (or -1 if there is an
error). We may decide we want this function to be more complex, and
handle things like block devices - this is a placeholder (that works)
for any more complicated function.
2016-11-30 15:18:57 -05:00
Ján Tomko
7a5df06e10 Introduce virDirOpenQuiet
A helper function that does not report any errors.
2016-06-24 14:20:57 +02:00
Ján Tomko
941ccbc174 Add virDirOpenIfExists
Just like virDirOpen, but it returns 0 without reporting an error
on ENOENT.
2016-06-24 14:20:57 +02:00
Ján Tomko
f0ced7086a Introduce virDirOpen
A helper that calls opendir and reports an error if it fails.
2016-06-24 14:20:57 +02:00
Ján Tomko
a4e6f1eb9c Introduce VIR_DIR_CLOSE
Introduce a helper that only calls closedir if DIR* is non-NULL
and sets it to NULL afterwards.
2016-06-23 21:58:33 +02:00
Michal Privoznik
7fccf12482 virfile: Introduce virFileRemoveLastComponent
Move some parts of virStorageFileRemoveLastPathComponent
into a separate function so they can be reused.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-05-13 14:17:15 +02:00
Nikolay Shirokovskiy
3506ad7f0a util: factor out reading file into preallocated buffer
Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
2016-05-03 08:58:30 -04:00
John Ferlan
1b046a6837 virfile: Rename virFileUnlink to virFileRemove
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
2015-09-21 08:24:16 -04:00
John Ferlan
35847860f6 virfile: Introduce virFileUnlink
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).
2015-09-02 08:59:53 -04:00
Cole Robinson
9ce409561a virfile: virDirCreate: Drop redundant FORCE_PERMS flag
The only two virDirCreate callers already use it
2015-05-19 19:29:39 -04:00
Ján Tomko
1390c26847 safezero: fall back to writing zeroes even when resizing
Remove the resize flag and use the same code path for all callers.
This flag was added by commit 18f0316 to allow virStorageFileResize
use 'safezero' while preserving the behavior.

Explicitly return -2 when a fallback to a different method should
be done, to make the code path more obvious.

Fail immediately when ftruncate fails in the mmap method,
as we did before commit 18f0316.
2015-01-09 13:48:23 +01:00
John Ferlan
18f03166fd virstoragefile: Have virStorageFileResize use safezero
Currently virStorageFileResize() function uses build conditionals to
choose either the posix_fallocate() or syscall(SYS_fallocate) with no
fallback in order to preallocate the space in the newly resized file.

Since the safezero code has a similar set of conditionals modify the
resize and safezero code in order to allow the resize logic to make use
of safezero to unify the look/feel of the code paths.

Add a new boolean (resize) to safezero() to make the optional decision
whether to try syscall(SYS_fallocate) if the posix_fallocate fails because
HAVE_POSIX_FALLOCATE is not defined (eg, return -1 and errno == 0).

Create a local safezero_sys_fallocate in order to handle the resize
code paths that support that.  If not present, the set errno = ENOSYS
in order to allow the caller to handle the failure scenarios.

Signed-off-by: John Ferlan <jferlan@redhat.com>
2014-12-16 13:11:35 -05:00
Michal Privoznik
be0782e199 Introduce virFileFindHugeTLBFS
This should iterate over mount tab and search for hugetlbfs among with
looking for the default value of huge pages.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-07-29 11:25:16 +01:00
Ján Tomko
f638c13ea4 Introduce virFileReadAllQuiet
Just like virFileReadAll, but returns -errno instead
of reporting errors. Useful for ignoring some errors.
2014-07-01 16:32:29 +02:00
Julio Faracco
1b14c449b8 util: use typedefs for enums in "src/util/" directory
In "src/util/" there are many enumeration (enum) declarations.
Sometimes, it's better using a typedef for variable types,
function types and other usages. Other enumeration will be
changed to typedef's in the future.

Signed-off-by: Julio Faracco <jcfaracco@gmail.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2014-05-05 14:30:01 -06:00
Natanael Copa
1ce2f1a434 util: introduce virDirRead wrapper for readdir
Introduce a wrapper for readdir. This helps us make sure that we always
set errno before calling readdir and it will make sure errors are
properly logged.

Signed-off-by: Natanael Copa <ncopa@alpinelinux.org>
Signed-off-by: Eric Blake <eblake@redhat.com>
2014-04-28 17:52:45 -06:00
Daniel P. Berrange
63a92e7220 Add helpers for resolving path to resources in build tree
Add virFileFindResource which will try to locate files
in the local build tree if the calling binary (eg libvirtd or
test suite) is being run from the build tree. The corresponding
virFileActivateDirOverride should be called at startup passing
in argv[0]. This will be examined for evidence of libtool magic
binary prefix / sub-directory in order to activate the override.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2014-04-25 11:42:28 +01:00
Eric Blake
91f349d8fd util: new virFileRelLinkPointsTo function
When checking if two filenames point to the same inode (whether
by hardlink or symlink), sometimes one of the names might be
relative.  This convenience function makes it easier to check.

* src/util/virfile.h (virFileRelLinkPointsTo): New prototype.
* src/util/virfile.c (virFileRelLinkPointsTo): New function.
* src/libvirt_private.syms (virfile.h): Export it.
* src/xen/xm_internal.c (xenXMDomainGetAutostart): Use it.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-04-11 20:00:42 -06:00
Eric Blake
5160ab795a util: move detection of shared filesystems
The code in virstoragefile.c is getting more complex as I
consolidate backing chain handling code.  But for the setuid
virt-login-shell, we don't need to crawl backing chains.  It's
easier to audit things for setuid security if there are fewer
files involved, so this patch moves the one function that
virFileOpen() was actually relying on to also live in virfile.c.

* src/util/virstoragefile.c (virStorageFileIsSharedFS)
(virStorageFileIsSharedFSType): Move...
* src/util/virfile.c (virFileIsSharedFS, virFileIsSharedFSType):
...to here, and rename.
(virFileOpenAs): Update caller.
* src/security/security_selinux.c
(virSecuritySELinuxSetFileconHelper)
(virSecuritySELinuxSetSecurityAllLabel)
(virSecuritySELinuxRestoreSecurityImageLabelInt): Likewise.
* src/security/security_dac.c
(virSecurityDACRestoreSecurityImageLabelInt): Likewise.
* src/qemu/qemu_driver.c (qemuOpenFileAs): Likewise.
* src/qemu/qemu_migration.c (qemuMigrationIsSafe): Likewise.
* src/util/virstoragefile.h: Adjust declarations.
* src/util/virfile.h: Likewise.
* src/libvirt_private.syms (virfile.h, virstoragefile.h): Move
symbols as appropriate.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-04-01 10:38:14 -06:00
Nehal J Wani
2250a2b5d2 Add parameter to wait for lock in file locking APIs
Our current pidfile acquire APis (virPidFileAcquire) simply return -1 upon
failure to acquire a lock. This patch adds a parameter 'bool waitForLock'
which instructs the APIs if we want to make it block and wait for the lock
or not.
2014-03-17 10:04:47 -06:00
Daniel P. Berrange
c321bfc5c3 Add virFileMakeParentPath helper function
Add a helper function which takes a file path and ensures
that all directory components leading up to the file exist.
IOW, it strips the filename part of the path and passes
the result to virFileMakePath.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2014-02-18 12:39:06 +00:00
Daniel P. Berrange
d45b833d14 Pull lxcContainerGetSubtree out into shared virfile module
Move the code for lxcContainerGetSubtree into the virfile
module creating 2 new functions

  int virFileGetMountSubtree(const char *mtabpath,
                             const char *prefix,
                             char ***mountsret,
                             size_t *nmountsret);
  int virFileGetMountReverseSubtree(const char *mtabpath,
                                    const char *prefix,
                                    char ***mountsret,
                                    size_t *nmountsret);

Add a new virfiletest.c test case to validate the new code.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-11-28 11:49:01 +00:00
Eric Blake
5327fad4f2 storage: avoid short reads while chasing backing chain
Our backing file chain code was not very robust to an ill-timed
EINTR, which could lead to a short read causing us to randomly
treat metadata differently than usual.  But the existing
virFileReadLimFD forces an error if we don't read the entire
file, even though we only care about the header of the file.
So add a new virFile function that does what we want.

* src/util/virfile.h (virFileReadHeaderFD): New prototype.
* src/util/virfile.c (virFileReadHeaderFD): New function.
* src/libvirt_private.syms (virfile.h): Export it.
* src/util/virstoragefile.c (virStorageFileGetMetadataInternal)
(virStorageFileProbeFormatFromFD): Use it.

Signed-off-by: Eric Blake <eblake@redhat.com>
2013-11-06 17:14:02 -07:00
Daniel P. Berrange
ccacd4fe3b Add virFileIsMountPoint function
Add a function for efficiently checking if a path is a filesystem
mount point.

NB will not work for bind mounts, only true filesystem mounts.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-11-05 15:51:47 +08:00
Daniel P. Berrange
a261996255 Introduce virFilePrintf() as a portable fprintf()
We can't use GNULIB's fprintf-posix due to licensing
incompatibilities. We do already have a portable
formatting via virAsprintf() which we got from GNULIB
though. We can use to create a virFilePrintf() function.

But really gnulib could just provide a 'fprintf'
module, that depended on just its 'asprintf' module.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-05-31 10:51:33 -06:00
Daniel P. Berrange
8aabd597b3 Add a helper API for setting up a NBD device with qemu-nbd
Add a virFileNBDDeviceAssociate method, which given a filename
will setup a NBD device, using qemu-nbd as the server.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-05-13 13:15:19 +01:00
Laine Stump
bfe7721d50 util: move virFile* functions from virutil.c to virfile.c
These all existed before virfile.c was created, and for some reason
weren't moved.

This is mostly straightfoward, although the syntax rule prohibiting
write() had to be changed to have an exception for virfile.c instead
of virutil.c.

This movement pointed out that there is a function called
virBuildPath(), and another almost identical function called
virFileBuildPath(). They really should be a single function, which
I'll take care of as soon as I figure out what the arglist should look
like.
2013-05-10 13:09:30 -04:00
Daniel P. Berrange
035cdaa00b Introduce a virFileDeleteTree method
Introduce a method virFileDeleteTree for recursively deleting
an entire directory tree

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-04-15 17:35:31 +01:00
Michal Privoznik
4ca6f5089f Drop useless virFileWrapperFdCatchError
We are requesting for stderr catching for all cases in
virFileWrapperFdNew(). There is no need to have a separate
function just to report an error, esp. when we can do it in
virFileWrapperFdClose().
2013-02-08 09:11:51 +01:00
Michal Privoznik
34e8f63a32 qemu: Report errors from iohelper
Currently, we use iohelper when saving/restoring a domain.
However, if there's some kind of error (like I/O) it is not
propagated to libvirt. Since it is not qemu who is doing
the actual write() it will not get error. The iohelper does.
Therefore we should check for iohelper errors as it makes
libvirt more user friendly.
2012-10-29 17:04:26 +01:00
Eric Blake
4ecb723b9e maint: fix up copyright notice inconsistencies
https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.

* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/;  If/.  If/
2012-09-20 16:30:55 -06:00
Osier Yang
f9ce7dad60 Desert the FSF address in copyright
Per the FSF address could be changed from time to time, and GNU
recommends the following now: (http://www.gnu.org/licenses/gpl-howto.html)

  You should have received a copy of the GNU General Public License
  along with Foobar.  If not, see <http://www.gnu.org/licenses/>.

This patch removes the explicit FSF address, and uses above instead
(of course, with inserting 'Lesser' before 'General').

Except a bunch of files for security driver, all others are changed
automatically, the copyright for securify files are not complete,
that's why to do it manually:

  src/security/security_selinux.h
  src/security/security_driver.h
  src/security/security_selinux.c
  src/security/security_apparmor.h
  src/security/security_apparmor.c
  src/security/security_driver.c
2012-07-23 10:50:50 +08:00
Daniel P. Berrange
9612e4b2e7 Move loop device setup code into virfile.{c,h}
While it is not currently used elsewhere in libvirt, the code
for finding a free loop device & associating a file with it
is not LXC specific. Move it into the viffile.{c,h} file where
potentially shared code is more commonly kept.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-07-05 10:46:10 +01:00