LU-14616 readahead: fix reserving for unaliged read

[fs/lustre-release.git] / lustre / llite / rw.c

diff --git a/lustre/llite/rw.c b/lustre/llite/rw.c
index 126c583..3f16b3e 100644 (file)
--- a/lustre/llite/rw.c
+++ b/lustre/llite/rw.c
@@ -94,6 +94,13 @@ static unsigned long ll_ra_count_get(struct ll_sb_info *sbi,
         * LRU pages, otherwise, it could cause deadlock.
         */
        pages = min(sbi->ll_cache->ccc_lru_max >> 2, pages);
+       /**
+        * if this happen, we reserve more pages than needed,
+        * this will make us leak @ra_cur_pages, because
+        * ll_ra_count_put() acutally freed @pages.
+        */
+       if (WARN_ON_ONCE(pages_min > pages))
+               pages_min = pages;
 
        /*
         * If read-ahead pages left are less than 1M, do not do read-ahead,