LU-7340 mdd: changelogs garbage collection

[fs/lustre-release.git] / lustre / obdclass / llog_cat.c

diff --git a/lustre/obdclass/llog_cat.c b/lustre/obdclass/llog_cat.c
index 084edea..1628cc8 100644 (file)
--- a/lustre/obdclass/llog_cat.c
+++ b/lustre/obdclass/llog_cat.c
@@ -997,6 +997,28 @@ __u64 llog_cat_size(const struct lu_env *env, struct llog_handle *cat_llh)
 }
 EXPORT_SYMBOL(llog_cat_size);
 
+/* currently returns the number of "free" entries in catalog,
+ * ie the available entries for a new plain LLOG file creation,
+ * even if catalog has wrapped
+ */
+__u32 llog_cat_free_space(struct llog_handle *cat_llh)
+{
+       /* simulate almost full Catalog */
+       if (OBD_FAIL_CHECK(OBD_FAIL_CAT_FREE_RECORDS))
+               return cfs_fail_val;
+
+       if (cat_llh->lgh_hdr->llh_count == 1)
+               return LLOG_HDR_BITMAP_SIZE(cat_llh->lgh_hdr) - 1;
+
+       if (cat_llh->lgh_last_idx > cat_llh->lgh_hdr->llh_cat_idx)
+               return LLOG_HDR_BITMAP_SIZE(cat_llh->lgh_hdr) - 1 +
+                      cat_llh->lgh_hdr->llh_cat_idx - cat_llh->lgh_last_idx;
+
+       /* catalog is presently wrapped */
+       return cat_llh->lgh_hdr->llh_cat_idx - cat_llh->lgh_last_idx;
+}
+EXPORT_SYMBOL(llog_cat_free_space);
+
 static int llog_cat_reverse_process_cb(const struct lu_env *env,
                                       struct llog_handle *cat_llh,
                                       struct llog_rec_hdr *rec, void *data)