Add APIs that allow to dynamically register driver backends so that the
list of available drivers does not need to be known during compile time.

This will allow us to modularize the storage driver on runtime.

Create a virscsihost.c and place the functions there. That removes the
last #ifdef __linux__ from virutil.c.

Take the opporunity to also change the function names and in one case
the parameters slightly

Use the new virNodeDeviceGetParentName instead. Modify the callers to
build the node device scsi_host# name string in order to call the new
function so that proper lookup occurs.

Rather than have them mixed in with the virutil apis, create a separate
virvhba.c module and move the vHBA related calls into there. Soon there
will be more added.

Also modify the names of the functions and some arguments to be more
indicative of what is really happening. Adjust the callers respectively.

While I was changing fchosttest, rather than the non-descriptive names
test1...test6, rename them to match what the test is doing.

They are used only in the SCSI backend driver so there's no need to
pollute the headers.

The iSCSI backend driver was using stuff from the SCSI driver without
making sure that it's compiled in. Move the common code into the
storage_util.c since it does not contain any specific code.

The file became a garbage dump for all kinds of utility functions over
time. Move them to a separate file so that the files can become a clean
interface for the storage backends.

https://bugzilla.redhat.com/show_bug.cgi?id=1349696

As it turns out using only the 'parent' to achieve the goal of a
consistent vHBA parent has issues with reboots where the scsi_hostX
parent could change to scsi_hostY causing either failure to create
the vHBA or usage of the wrong HBA for our vHBA.

Thus add the ability to search for the "parent" by the parent wwnn/
wwpn values or just a fabric_name if someone only cares to ensure
usage of the same SAN for the vHBA.

Remove duplicated code - make one simple path through
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Move the check for an already existing vHBA to the top of the function.
No sense in first decoding a provided parent if the next thing we're going
to do is fail if a provided wwnn/wwpn already exists.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Use the ret = -1, goto cleanup, etc. rather than current hodgepodge.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Do not call it with a magic constant matching the length
of the pattern.

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

The directories we iterate over are unlikely to contain any entries
starting with a dot, other than '.' and '..' which is already skipped
by virDirRead.

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

We had both and the only difference was that the latter also included
information about multifunction setting.  The problem with that was that
we couldn't use functions made for only one of the structs (e.g.
parsing).  To consolidate those two structs, use the one in virpci.h,
include that in domain_conf.h and add the multifunction member in it.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

If the pool creation thread happens to detect the luns in
the scsi target, the size parameters will be calculated as
part of the refreshPool called from storagePoolCreate().

This means the virStoragePoolFCRefreshThread (commit id
'512b8747') waiting to run and "refresh" the pool will
essentially double the allocation and capacity values.
A separate refresh would correct the values.

To avoid this, the FCRefreshThread needs to reinitialize
the pool size values prior to calling virStorageBackendSCSIFindLUs
which eventually calls virStorageBackendSCSINewLun and
updates the size values for each volume found.

https://bugzilla.redhat.com/show_bug.cgi?id=1276198

Prior to commit id '98322052' failure to saferead the block device would
cause an error to be logged and the device to be skipped while attempting
to discover/create a stable target path for a new LUN (NPIV).

This was because virStorageBackendSCSIFindLUs ignored errors from
processLU and virStorageBackendSCSINewLun.

Ignoring the failure allowed a multipath device with an "active" and
"ghost" to be present on the host with the "ghost" block device being
ignored. This patch will return a -2 to the caller indicating the desire
to ignore the block device since it cannot be used directly rather than
fail the pool startup.

Similar to the openflags which allow VIR_STORAGE_VOL_OPEN_NOERROR to be
passed to avoid open errors, add a 'readflags' variable so that in the
future read failures could also be ignored.

https://bugzilla.redhat.com/show_bug.cgi?id=1277781

The virStoragePoolFCRefreshThread had passed a pointer to the pool obj
in the virStoragePoolFCRefreshInfoPtr; however, we cannot assume that
the pool exists still since we don't keep the pool lock throughout
the duration of the thread.

Therefore, instead of passing the pool obj pointer, pass the UUID of
the pool and perform a lookup.  If found, then we can perform the
refresh using the locked pool obj pointer; otherwise, we just exit
the thread since the pool is now gone.

Change the field name from 'name' to 'fchost_name' to better id it.

Related to :

https://bugzilla.redhat.com/show_bug.cgi?id=1171933

Rather than ignore the return status from virStorageBackendSCSIFindLUs,
cause a failure to start the pool if a -1 is returned. Issue was noted
during testing of the bz for iscsi that 'scsi' and 'fc' pools don't fail.

https://bugzilla.redhat.com/show_bug.cgi?id=1224233

Currently it's not possible to determine the difference between a
fatal memory allocation or failure to open/read the directory error
with a perhaps less fatal, I didn't find the "block" device in the
directory (which may be a disk entry without a block device).

In the case of the latter, we shouldn't cause failure to continue
searching in the caller (virStorageBackendSCSIFindLUs), rather we
should allow trying reading the next directory entry.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Instead of initializing return value to zero (success) and overwriting
it on every failure just before the control jumps onto 'out' label,
let's initialize to an error value and set to zero only when we are
sure about the success. Just follow the pattern we have in the rest of
the code.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Instead of initializing return value to zero (success) and overwriting
it on every failure just before the control jumps onto 'out' label,
let's initialize to an error value and set to zero only when we are
sure about the success. Just follow the pattern we have in the rest of
the code.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

commit id '1e13eff4' didn't init found when changed from a bool to
an int in virStoragePoolFCRefreshThread and Coverity...

https://bugzilla.redhat.com/show_bug.cgi?id=1171933

Adjust the processLU error returns to be a bit more logical. Currently,
the calling code cannot determine the difference between a non disk/lun
volume and a processed/found disk/lun. It can also not differentiate
between perhaps real/fatal error and one that won't necessarily stop
the code from finding other volumes.

After this patch virStorageBackendSCSIFindLUsInternal will stop processing
as soon as a "fatal" message occurs rather than continuting processing
for no apparent reason. It will also only set the *found value when
at least one of the processLU's was successful.

With the failed return, if the reason for the stop was that the pool
target path did not exist, was /dev, was /dev/, or did not start with
/dev, then iSCSI pool startup and refresh will fail.

Rather than passing/returning a pointer to a boolean to indicate that
perhaps we should try again - adjust the return of the call to return
the count of LU's found during processing, then let the caller decide
what to do with that value.

Use virStorageBackendPoolUseDevPath API to determine whether creation of
stable target path is possible for the volume.

This will differentiate a failed virStorageBackendStablePath which won't
need to be fatal. Thus, we'll add a -2 return value to differentiate that
the failure was a result of either the inability to find the symlink for
the device or failure to open the target path directory

Invert the logical of retval and clean up code paths, especially goto's
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Seems to be a remnant that was never cleaned up from original submit...
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

In order to be able to use 'checkPool' inside functions which do not
have any connection reference, 'conn' attribute needs to be discarded
from the checkPool's signature, since it's not used by any storage backend
anyway.

This reverts commit f1856eb6.

Now that we can update capacity from image metadata,
we don't need to skip the update.

https://bugzilla.redhat.com/show_bug.cgi?id=1159180

Move the API from the backend to storage_conf and rename it to
virStoragePoolGetVhbaSCSIHostParent.  A future patch will need to
use this functionality from storage_conf

https://bugzilla.redhat.com/show_bug.cgi?id=1152382

When libvirt create's the vport (VPORT_CREATE) for the vHBA, there isn't
enough "time" between the creation and the running of the following
backend->refreshPool after a backend->startPool in order to find the LU's.
Population of LU's happens asynchronously when udevEventHandleCallback
discovers the "new" vHBA port.  Creation of the infrastructure by udev
is an iterative process creating and discovering actual storage devices and
adjusting the environment.

Because of the time it takes to discover and set things up, the backend
refreshPool call done after the startPool call will generally fail to
find any devices. This leaves the newly started pool appear empty when
querying via 'vol-list' after startup. The "workaround" has always been
to run pool-refresh after startup (or any time thereafter) in order to
find the LU's. Depending on how quickly run after startup, this too may
not find any LUs in the pool. Eventually though given enough time and
retries it will find something if LU's exist for the vHBA.

This patch adds a thread to be executed after the VPORT_CREATE which will
attempt to find the LU's without requiring the external run of refresh-pool.
It does this by waiting for 5 seconds and searching for the LU's. If any
are found, then the thread completes; otherwise, it will retry once more
in another 5 seconds.  If none are found in that second pass, the thread
gives up.

Things learned while investigating this... No need to try and fill the
pool too quickly or too many times. Over the course of creation, the udev
code may 'add', 'change', and 'delete' the same device. So if the refresh
code runs and finds something, it may display it only to have a subsequent
refresh appear to "lose" the device. The udev processing doesn't seem to
have a way to indicate that it's all done with the creation processing of a
newly found vHBA. Only the Lone Ranger has silver bullets to fix everything.

Fix a problem in the getBlockDevice and processLU where retval initialized
to zero causing some failures to erroneously continue through to the
virStorageBackendSCSINewLun with an attempt to find a path for "/dev/(null)".
This would fail approximately 10 seconds later with debug message:

virStorageBackendSCSINewLun:203 :
     No stable path found for '/dev/(null)' in '/dev/disk/by-path'

The root cause of the issue is for many /sys/bus/scsi/devices/<lun path>
there is no "block*" device found for the vHBA's, where "<lun path>" are
the various paths created for the vHBA, such as "17:0:0:0", "17:0:1:0",
"17:0:2:0", "17:0:3:0", etc.  If the block device isn't found, then the
directory should just be ignored rather than attempting to process it.

The bug was that in getBlockDevice the assumption was "block" would exist
and either getNewStyleBlockDevice or getOldStyleBlockDevice would fill in
@block_device. However, if 'block*' doesn't exist, then the code returned
NULL for block_device *and* a good (zero) retval value.  This caused the
processLU code to attempt the virStorageBackendSCSINewLun which failed
"at some point in time" in the future.

After this change - on test system the refresh-pool didn't have a noticable
pause of about 20 seconds - it completed within a second since no longer
was there an attempt/need to find "/dev/(null)".

Additionally, the virStorageBackendSCSIFindLU's shouldn't be declaring
found unless the processLU actually returns success. This will be
important in the followup patch which relies on whether a LU was found.

Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=1160926

Introduce a 'managed' attribute to allow libvirt to decide whether to
delete a vHBA vport created via external means such as nodedev-create.
The code currently decides whether to delete the vHBA based solely on
whether the parent was provided at creation time. However, that may not
be the desired action, so rather than delete and force someone to create
another vHBA via an additional nodedev-create allow the configuration of
the storage pool to decide the desired action.

During createVport when libvirt does the VPORT_CREATE, set the managed
value to YES if not already set to indicate to the deleteVport code that
it should delete the vHBA when the pool is destroyed.

If libvirtd is restarted all the memory only state was lost, so for a
persistent storage pool, use the virStoragePoolSaveConfig in order to
write out the managed value.

Because we're now saving the current configuration, we need to be sure
to not save the parent in the output XML if it was undefined at start.
Saving the name would cause future starts to always use the same parent
which is not the expected result when not providing a parent. By not
providing a parent, libvirt is expected to find the best available
vHBA port for each subsequent (re)start.

At deleteVport, use the new managed value to decide whether to execute
the VPORT_DELETE.  Since we no longer save the parent in memory or in
XML when provided, if it was not provided, then we have to look it up.

https://bugzilla.redhat.com/show_bug.cgi?id=1160926

Passing a copy of the storage pool adapter to a function just changes the
copy of the fields in the particular function and then when returning to
the caller those changes are discarded.  While not yet biting us in the
storage clean-up case, it did cause an issue for the fchost storage pool
startup case, createVport.  The issue was at startup, if no parent is found
in the XML, the code will search for the 'best available' parent and then
store that in the in memory copy of the adapter.  Of course, in this case
it was a copy, so when returning to the virStorageBackendSCSIStartPool that
change was discarded (or lost) from the pool->def->source.adapter which
meant at shutdown (deleteVport), the code assumed no adapter was passed
and skipped the deletion, leaving the vHBA created by libvirt still defined
requiring an additional stop of a nodedev-destroy to remove.

Adjusted the createVport to take virStoragePoolDefPtr instead of the
adapter copy. Then use the virStoragePoolSourceAdapterPtr when processing.
A future patch will need the 'def' anyway, so this just sets up for that.

https://bugzilla.redhat.com/show_bug.cgi?id=1160565

The existing code assumed that the configuration of a 'parent' attribute
was correct for the createVport path. As it turns out, that may not be
the case which leads errors during the deleteVport path because the
wwnn/wwpn isn't associated with the parent.

With this change the following is reported:

error: Failed to start pool fc_pool_host3
error: XML error: Parent attribute 'scsi_host4' does not match parent 'scsi_host3' determined for the 'scsi_host16' wwnn/wwpn lookup.

for XML as follows:

  <pool type='scsi'>
    <name>fc_pool</name>
    <source>
      <adapter type='fc_host' parent='scsi_host4' wwnn='5001a4aaf3ca174b' wwpn='5001a4a77192b864'/>
    </source>

Where 'nodedev-dumpxml scsi_host16' provides:

  <device>
    <name>scsi_host16</name>
    <path>/sys/devices/pci0000:00/0000:00:04.0/0000:10:00.0/host3/vport-3:0-11/host16</path>
    <parent>scsi_host3</parent>
    <capability type='scsi_host'>
      <host>16</host>
      <unique_id>13</unique_id>
      <capability type='fc_host'>
        <wwnn>5001a4aaf3ca174b</wwnn>
        <wwpn>5001a4a77192b864</wwpn>
...

The patch also adjusts the description of the storage pool to describe the
restrictions.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>