Hello all,
here is a small feature patch. Its intention is to give the user more control
over the files performance/io-cache really caches. If the user knows exactly
which files should be cached and which shouldn't there is currently no way to
tell glusterfs _not_ to cache certain pattern. This patch allows you to
disable caching by setting the priority of a pattern to "0". If you do not
give any priority option it works just like before and caches everything.
Honestly I am not totally sure that disabling caching works the way we did it,
please comment.
--
Regards,
Stephan
--- glusterfs-2.0.6/xlators/performance/io-cache/src/io-cache.c 2009-08-14 01:32:51.000000000 +0200
+++ glusterfs-2.0.6-skraw/xlators/performance/io-cache/src/io-cache.c 2009-09-12 15:00:52.000000000 +0200
@@ -553,9 +553,14 @@
uint32_t priority = 0;
struct ioc_priority *curr = NULL;
- list_for_each_entry (curr, &table->priority_list, list) {
- if (is_match (path, curr->pattern))
- priority = curr->priority;
+ if (list_empty(&table->priority_list)) {
+ priority = 1;
+ }
+ else {
+ list_for_each_entry (curr, &table->priority_list, list) {
+ if (is_match (path, curr->pattern))
+ priority = curr->priority;
+ }
}
return priority;
@@ -581,7 +586,7 @@
ioc_table_t *table = NULL;
ioc_inode_t *ioc_inode = NULL;
inode_t *inode = NULL;
- uint32_t weight = 0;
+ uint32_t weight = 0xffffffff;
const char *path = NULL;
local = frame->local;
@@ -633,6 +638,13 @@
*/
fd_ctx_set (fd, this, 1);
}
+
+ /* weight = 0, we disable caching on it */
+ if (weight == 0) {
+ /* we allow a pattern-matched cache disable this way
+ */
+ fd_ctx_set (fd, this, 1);
+ }
}
FREE (local);
@@ -664,7 +676,7 @@
ioc_local_t *local = NULL;
ioc_table_t *table = NULL;
ioc_inode_t *ioc_inode = NULL;
- uint32_t weight = 0;
+ uint32_t weight = 0xffffffff;
const char *path = NULL;
local = frame->local;
@@ -699,6 +711,12 @@
fd_ctx_set (fd, this, 1);
}
+ /* weight = 0, we disable caching on it */
+ if (weight == 0) {
+ /* we allow a pattern-matched cache disable this way
+ */
+ fd_ctx_set (fd, this, 1);
+ }
}
frame->local = NULL;
