glusterfs.git/xlators/mgmt/glusterd/src/glusterd-snapshot.c, branch v3.7.0alpha0

glusterd/snapshot : While snapshot restore, compute quota checksum.

2015-04-10T08:19:09+00:00

Problem : During snapshot restore we anyways copy the quota conf file
after that we need to compute the checksum for that. If not, there
might be a checksum mismatch during glusterd handshake.

Solution : Compute a checksum file for quota conf file if its
present.

Change-Id: Ic4a6567c6ede9923443abf4ca59380679be88094
BUG: 1202436
Signed-off-by: Sachin Pandit 
Reviewed-on: http://review.gluster.org/9901
Tested-by: Gluster Build System 
Reviewed-by: Avra Sengupta 
Reviewed-by: Krishnan Parthasarathi 
Tested-by: Krishnan Parthasarathi

Snapshot: Remove brick details on snapshot create error

2015-04-09T12:45:08+00:00

Since we are not providing complete details of stopped
bricks on snapshot create error, it is better to remove
the incomplete brick details.

BUG: 1205596
Change-Id: I73386059c0d29a6cbe7f2bb6834d8b8fb393db0a
Signed-off-by: Mohammed Rafi KC 
Reviewed-on: http://review.gluster.org/9999
Reviewed-by: Avra Sengupta 
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

Avoid conflict between contrib/uuid and system uuid

2015-04-04T17:48:35+00:00

glusterfs relies on Linux uuid implementation, which
API is incompatible with most other systems's uuid. As
a result, libglusterfs has to embed contrib/uuid,
which is the Linux implementation, on non Linux systems.
This implementation is incompatible with systtem's
built in, but the symbols have the same names.

Usually this is not a problem because when we link
with -lglusterfs, libc's symbols are trumped. However
there is a problem when a program not linked with
-lglusterfs will dlopen() glusterfs component. In
such a case, libc's uuid implementation is already
loaded in the calling program, and it will be used
instead of libglusterfs's implementation, causing
crashes.

A possible workaround is to use pre-load libglusterfs
in the calling program (using LD_PRELOAD on NetBSD for
instance), but such a mechanism is not portable, nor
is it flexible. A much better approach is to rename
libglusterfs's uuid_* functions to gf_uuid_* to avoid
any possible conflict. This is what this change attempts.

BUG: 1206587
Change-Id: I9ccd3e13afed1c7fc18508e92c7beb0f5d49f31a
Signed-off-by: Emmanuel Dreyfus 
Reviewed-on: http://review.gluster.org/10017
Tested-by: Gluster Build System 
Reviewed-by: Niels de Vos

Xlators : Fixed typos

2015-04-02T10:21:08+00:00

Change-Id: I948f85cb369206ee8ce8b8cd5e48cae9adb971c9
BUG: 1075417
Signed-off-by: Manikandan Selvaganesh 
Reviewed-on: http://review.gluster.org/9529
Reviewed-by: Niels de Vos 
Tested-by: Gluster Build System 
Reviewed-by: Kaleb KEITHLEY 
Reviewed-by: Humble Devassy Chirammal

glusterd: replace glusterd_volinfo_delete calls with glusterd_volinfo_unref

2015-03-30T09:43:36+00:00

volinfo has its own ref counting mechanism. While deleting a 
volinfo object its always wiser to check there is 0 reference
to it and then delete it.

Change-Id: I446bd83432bd94aa19e29c6026367dfc1231786f
BUG: 1183463
Signed-off-by: Atin Mukherjee 
Reviewed-on: http://review.gluster.org/9462
Tested-by: Gluster Build System 
Reviewed-by: Kaushal M

glusterd: Fixing wrong array comparison (Coverity fix)

2015-03-24T18:24:29+00:00

Coverity CID: 1256175

Change-Id: Ib29fc2eaa54a7ce8369918e68bf117d0f04ca94d
BUG: 789278
Signed-off-by: Nandaja Varma 
Reviewed-on: http://review.gluster.org/9679
Reviewed-by: Vijaikumar Mallikarjuna 
Tested-by: Gluster Build System 
Reviewed-by: Humble Devassy Chirammal 
Reviewed-by: Kaleb KEITHLEY 
Reviewed-by: Vijay Bellur

Snapshot/clone: clone of a snapshot that will act as a regular volume

2015-03-18T07:07:55+00:00

snapshot clone will allow us to take a snpahot of a snapshot.
Newly created clone volume will be a regular volume with read/write
permissions.

CLI command
snapshot clone  

Change-Id: Icadb993fa42fff787a330f8f49452da54e9db7de
BUG: 1199894
Signed-off-by: Mohammed Rafi KC 
Reviewed-on: http://review.gluster.org/9750
Tested-by: Gluster Build System 
Reviewed-by: Rajesh Joseph 
Reviewed-by: Vijay Bellur

glusterd: Protect the peer list and peerinfos with RCU.

2015-03-16T09:19:14+00:00

The peer list and the peerinfo objects are now protected using RCU.
Design patterns described in the Paul McKenney's RCU dissertation [1]
(sections 5 and 6) have been used to convert existing non-RCU protected
code to RCU protected code.

Currently, we are only targetting guaranteeing the existence of the
peerinfo objects, ie., we are only looking to protect deletes, not all
updaters. We chose this, as protecting all updates is a much more
complex task.

The steps used to accomplish this are,

1. Remove all long lived direct references to peerinfo objects (apart
from the peerinfo list). This includes references in glusterd_peerctx_t
(RPC), glusterd_friend_sm_event_t (friend state machine) and others.
This way no one has a reference to deleted peerinfo object.

2. Replace the direct references with indirect references, ie., use
peer uuid and peer hostname as indirect references to the peerinfo
object. Any reader or updater now uses the indirect references to get to
the actual peerinfo object, using glusterd_peerinfo_find. Cases where a
peerinfo cannot be found are handled gracefully.

3. The readers get and use the peerinfo object only within a RCU read
critical section. This prevents the object from being deleted/freed when
in actual use.

4. The deletion of a peerinfo object is done in a ordered manner
(glusterd_peerinfo_destroy). The object is first removed from the
peerinfo list using an atomic list remove, but the list head is not
reset to allow existing list readers to complete correctly. We wait for
readers to complete, before resetting the list head. This removes the
object from the list completely. After this no new readers can get a
reference to the object, and it can be freed.

This change was developed on the git branch at [2]. This commit is a
combination of the following commits on the development branch.
  d7999b9 Protect the glusterd_conf_t->peers_list with RCU.
  0da85c4 Synchronize before INITing peerinfo list head after removing
          from list.
  32ec28a Add missing rcu_read_unlock
  8fed0b8 Correctly exit read critical section once peer is found.
  63db857 Free peerctx only on rpc destruction
  56eff26 Cleanup style issues
  e5f38b0 Indirection for events and friend_sm
  3c84ac4 In __glusterd_probe_cbk goto unlock only if peer already
          exists
  141d855 Address review comments on 9695/1
  aaeefed Protection during peer updates
  6eda33d Revert "Synchronize before INITing peerinfo list head after
          removing from list."
  f69db96 Remove unneeded line
  b43d2ec Address review comments on 9695/4
  7781921 Address review comments on 9695/5
  eb6467b Add some missing semi-colons
  328a47f Remove synchronize_rcu from
          glusterd_friend_sm_transition_state
  186e429 Run part of glusterd_friend_remove in critical section
  55c0a2e Fix gluster (peer status/ pool list) with no peers
  93f8dcf Use call_rcu to free peerinfo
  c36178c Introduce composite struct, gd_rcu_head

[1]: http://www.rdrop.com/~paulmck/RCU/RCUdissertation.2004.07.14e1.pdf
[2]: https://github.com/kshlm/glusterfs/tree/urcu

Change-Id: Ic1480e59c86d41d25a6a3d159aa3e11fbb3cbc7b
BUG: 1191030
Signed-off-by: Kaushal M 
Reviewed-on: http://review.gluster.org/9695
Tested-by: Gluster Build System 
Reviewed-by: Atin Mukherjee 
Reviewed-by: Anand Nekkunti 
Reviewed-by: Krishnan Parthasarathi 
Tested-by: Krishnan Parthasarathi

snapshot: append timestamp with snapname

2015-03-10T11:42:00+00:00

Appending GMT time stamp with snapname by default.
If no-timestamp flag is given during snapshot creation,
then time stamp will not append with snapname;

Initial consumer of this feature is Samba's Shadow Copy
feature. This feature allows Windows user to get previous 
revisions of a file. For this feature to work snapshot 
names under .snaps folder (USS) should have timestamp in 
following format appended:
@GMT-YYYY.MM.DD-hh.mm.ss

PS: https://www.samba.org/samba/docs/man/manpages/vfs_shadow_copy2.8.html

This format is configurable by Samba conf file. Due to a 
limitation in Windows directory access the exact format 
cannot be used by USS. Therefore we have modified the file 
format to:
_GMT-YYYY.MM.DD-hh.mm.ss

Snapshot scheduling feature also required to append timestamp 
to the snapshot name therefore timestamp is appended in 
snapshot creation itself instead of doing the changes in 
snapview server.

More info:
https://www.mail-archive.com/gluster-users@gluster.org/msg18895.html

Change-Id: Idac24670948cf4c0fbe916ea6690e49cbc832d07
BUG: 1189473
Signed-off-by: Mohammed Rafi KC 
Reviewed-on: http://review.gluster.org/9597
Tested-by: Gluster Build System 
Reviewed-by: Rajesh Joseph 
Reviewed-by: Krishnan Parthasarathi 
Tested-by: Krishnan Parthasarathi

glusterd: Replace libglusterfs lists with liburcu lists

2015-03-04T07:50:22+00:00

This patch replaces usage of the libglusterfs lists data structures and
API in glusterd with the lists data structures and API from liburcu. The
liburcu data structes and APIs are a drop-in replacement for
libglusterfs lists.

All usages have been changed to keep the code consistent, and free from
confusion.

NOTE: glusterd_conf_t->xprt_list still uses the libglusterfs data
structures and API, as it holds rpc_transport_t objects, which is not a
part of glusterd and is not being changed in this patch.

This change was developed on the git branch at [1]. This commit is a
combination of the following commits on the development branch.
  6dac576 Replace libglusterfs lists with liburcu lists
  a51b5ab Fix compilation issues
  d98a06f Fix merge issues
  a5d918e Remove merge remnant
  1cca113 More style cleanup
  1917be3 Address review comments on 9624/1
  8d10f13 Use cds_lists for glusterd_svc_t
  524ad5d Add rculist header in glusterd-conn-helper.c
  646f294 glusterd: add list_add_order API honouring rcu

[1]: https://github.com/kshlm/glusterfs/tree/urcu

Change-Id: Ic613c5b6e496a677b9d3de15fc042a0492109fb0
BUG: 1191030
Signed-off-by: Kaushal M 
Signed-off-by: Krishnan Parthasarathi 
Reviewed-on: http://review.gluster.org/9624
Tested-by: Gluster Build System 
Reviewed-by: Atin Mukherjee 
Reviewed-by: Gaurav Kumar Garg 
Reviewed-by: Anand Nekkunti