xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

ocfs2: Negotiate locking protocol versions.

Browse Source 
Currently, when ocfs2 nodes connect via TCP, they advertise their
compatibility level.  If the versions do not match, two nodes cannot speak
to each other and they disconnect. As a result, this provides no forward or
backwards compatibility.

This patch implements a simple protocol negotiation at the dlm level by
introducing a major/minor version number scheme for entities that
communicate.  Specifically, o2dlm has a major/minor version for interaction
with o2dlm on other nodes, and ocfs2 itself has a major/minor version for
interacting with the filesystem on other nodes.

This will allow rolling upgrades of ocfs2 clusters when changes to the
locking or network protocols can be done in a backwards compatible manner.
In those cases, only the minor number is changed and the negotatied protocol
minor is returned from dlm join. In the far less likely event that a
required protocol change makes backwards compatibility impossible, we simply
bump the major number.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
This commit is contained in:
Joel Becker
2008-01-25 17:02:21 -08:00
committed by Mark Fasheh
parent 3e6bdf473f
commit d24fbcda0c
12 changed files with 288 additions and 34 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
fs/ocfs2/dlm/dlmapi.h
View File

@@ -193,7 +193,12 @@ enum dlm_status dlmunlock(struct dlm_ctxt *dlm,
dlm_astunlockfunc_t *unlockast,
void *data);
struct dlm_ctxt * dlm_register_domain(const char *domain, u32 key);
struct dlm_protocol_version {
u8 pv_major;
u8 pv_minor;
};
struct dlm_ctxt * dlm_register_domain(const char *domain, u32 key,
struct dlm_protocol_version *fs_proto);
void dlm_unregister_domain(struct dlm_ctxt *dlm);