diff options
| -rw-r--r-- | fs/dlm/lockspace.c | 3 | ||||
| -rw-r--r-- | include/linux/dlm.h | 17 | ||||
| -rw-r--r-- | include/uapi/linux/dlm.h | 2 |
3 files changed, 21 insertions, 1 deletions
diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c index 8a4351ee9a42..a7ac0fcb4ef3 100644 --- a/fs/dlm/lockspace.c +++ b/fs/dlm/lockspace.c @@ -629,6 +629,9 @@ int dlm_new_user_lockspace(const char *name, const char *cluster, void *ops_arg, int *ops_result, dlm_lockspace_t **lockspace) { + if (flags & DLM_LSFL_SOFTIRQ) + return -EINVAL; + return __dlm_new_lockspace(name, cluster, flags, lvblen, ops, ops_arg, ops_result, lockspace); } diff --git a/include/linux/dlm.h b/include/linux/dlm.h index c58c4f790c04..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 * @@ -55,6 +58,11 @@ struct dlm_lockspace_ops { * used to select the directory node. Must be the same on all nodes. * 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 @@ -121,7 +129,14 @@ 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, diff --git a/include/uapi/linux/dlm.h b/include/uapi/linux/dlm.h index e7e905fb0bb2..4eaf835780b0 100644 --- a/include/uapi/linux/dlm.h +++ b/include/uapi/linux/dlm.h @@ -71,6 +71,8 @@ struct dlm_lksb { /* DLM_LSFL_TIMEWARN is deprecated and reserved. DO NOT USE! */ #define DLM_LSFL_TIMEWARN 0x00000002 #define DLM_LSFL_NEWEXCL 0x00000008 +/* currently reserved due in-kernel use */ +#define __DLM_LSFL_RESERVED0 0x00000010 #endif /* _UAPI__DLM_DOT_H__ */ |