08-Dec-16 15:17, John Ferlan пишет:
On 12/08/2016 04:19 AM, Maxim Nestratov wrote:
08-Dec-16 02:22, John Ferlan пишет:
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I see what you mean; however, IMO vstorage should be separate. Maybe there's another opinion out there, but since you're requiring "something" else to be installed in order to get the WITH_VSTORAGE to be set to 1, then a separate file is in order.
Not sure they're comparable, but zfs has its own. Having separated vstorage reduces the chance that some day some incompatible logic is added/altered in the *fs.c (or vice versa). Ok. I will try.
I think you should consider the *_fs.c code to be the "default" of sorts. That is default file/dir structure with netfs added in. The vstorage may just be some file system, but it's not something (yet) on "every" distribution. I did not understand actually, what you mean "be the "default" of sorts." As I have understood - what I need to do is to create backend_vstorage.c with all create/delete/* functionality.
Sorry - I was trying to think of a better way to explain... The 'fs' and 'nfs' pool are default of sorts because one can "ls" (on UNIX/Linux) or "dir" (on Windows) and get a list of files.
"ls" and "dir" are inherent to the OS, while in this case vstorage commands are installed separately. Once you mounted your vstorage cluster to a local filesystem you can also "ls" it. Thus, I can't see much difference from nfs here.
So if it's more like NFS, then how does one ensure that the local userid X is the same as the remote userid X? NFS has a root-squashing concept that results in numerous shall we say "interesting" issues.
Vstorage doesn't have users concept. Authentication is made by a password per node just once. If authentication passes, a key is stored in /etc/vstorage/clusters/CLUSTER_NAME/auth_digest.key Then, permissions are set to a mount point during mounting with -u USER -g GROUP -m MODE options provided to vstorage-mount command.
Check out the virFileOpen*, virDirCreate, and virFileRemove...
Also what about viFileIsShareFSType? And security_selinux.c code for NFS? If you use cscope, just search on NFS.
In the virStorageBackendVzStart, I see:
VSTORAGE_MOUNT -c $pool.source.name $pool.target.path
This call certainly lacks user/group/mode parameters and should be fixed in the next series.
where VSTORAGE_MOUNT is a build (configure.ac) definition that is the "Location or name of vstorage-mount program" which would only be set if the proper package was installed.
In the virStorageBackendVzfindPoolSources, I see:
VSTORAGE discover
which I assume generates some list of remote "services" (for lack of a better term) which can be used as/for pool.source.name in order to be well mounted by the VSTORAGE_MOUNT program.
Compare that to NFS, which uses mount which is included in well every distro I can think of. That's a big difference. Also let's face it, NFS has been the essential de facto goto tool to access remote storage for a long time. Personally, I'd rather see the NFS code split out of the *_fs.c backend, but I don't have the desire/time to do it - so it stays as is.
To sum this up, you still think that copy and paste isn't a problem here and will create more value than do any harm, right? Maxim [snip]