diff options
Diffstat (limited to 'include/linux/dlm.h')
| -rw-r--r-- | include/linux/dlm.h | 25 |
1 files changed, 17 insertions, 8 deletions
diff --git a/include/linux/dlm.h b/include/linux/dlm.h index ff951e9f6f20..bacda9898f2b 100644 --- a/include/linux/dlm.h +++ b/include/linux/dlm.h @@ -35,6 +35,9 @@ struct dlm_lockspace_ops { int num_slots, int our_slot, uint32_t generation); }; +/* only relevant for kernel lockspaces, will be removed in future */ +#define DLM_LSFL_SOFTIRQ __DLM_LSFL_RESERVED0 + /* * dlm_new_lockspace * @@ -53,14 +56,13 @@ struct dlm_lockspace_ops { * The dlm should not use a resource directory, but statically assign * resource mastery to nodes based on the name hash that is otherwise * used to select the directory node. Must be the same on all nodes. - * DLM_LSFL_TIMEWARN - * The dlm should emit netlink messages if locks have been waiting - * for a configurable amount of time. (Unused.) - * DLM_LSFL_FS - * The lockspace user is in the kernel (i.e. filesystem). Enables - * direct bast/cast callbacks. * DLM_LSFL_NEWEXCL * dlm_new_lockspace() should return -EEXIST if the lockspace exists. + * DLM_LSFL_SOFTIRQ + * dlm request callbacks (ast, bast) are softirq safe. Flag should be + * preferred by users. Will be default in some future. If set the + * strongest context for ast, bast callback is softirq as it avoids + * an additional context switch. * * lvblen: length of lvb in bytes. Must be multiple of 8. * dlm_new_lockspace() returns an error if this does not match @@ -127,14 +129,21 @@ int dlm_release_lockspace(dlm_lockspace_t *lockspace, int force); * call. * * AST routines should not block (at least not for long), but may make - * any locking calls they please. + * any locking calls they please. If DLM_LSFL_SOFTIRQ for kernel + * users of dlm_new_lockspace() is passed the ast and bast callbacks + * can be processed in softirq context. Also some of the callback + * contexts are in the same context as the DLM lock request API, users + * must not hold locks while calling dlm lock request API and trying + * to acquire this lock in the callback again, this will end in a + * lock recursion. For newer implementation the DLM_LSFL_SOFTIRQ + * should be used. */ int dlm_lock(dlm_lockspace_t *lockspace, int mode, struct dlm_lksb *lksb, uint32_t flags, - void *name, + const void *name, unsigned int namelen, uint32_t parent_lkid, void (*lockast) (void *astarg), |