From 767a8a1be7012ca1445a62b61873f3bfdb719b13 Mon Sep 17 00:00:00 2001 From: Michael Vrable Date: Fri, 19 Mar 2010 15:59:00 -0700 Subject: [PATCH] Make dropping of inodes from cache more resistant to races. --- bluesky/cache.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/bluesky/cache.c b/bluesky/cache.c index 481390f..8d2cda1 100644 --- a/bluesky/cache.c +++ b/bluesky/cache.c @@ -58,15 +58,18 @@ static void flushd_inode(gpointer value, gpointer user_data) drop_caches(inode); /* If the only references are the one we hold and the one in the - * filesystem inum->inode hash table... The check for a refcount - * of 2 shouldn't be necessary so it should be okay if there is a - * race on the check. */ + * filesystem inum->inode hash table... First check the refcount + * without the lock for speed, but if the check looks good verify + * it after taking the filesystem lock. */ if (inode->refcount == 2) { - g_log("bluesky/flushd", G_LOG_LEVEL_DEBUG, - "Trying to drop inode %"PRIu64" from cache", inode->inum); g_mutex_lock(fs->lock); - if (g_hash_table_remove(fs->inodes, &inode->inum)) - bluesky_inode_unref(inode); + if (inode->refcount == 2) { + g_log("bluesky/flushd", G_LOG_LEVEL_DEBUG, + "Trying to drop inode %"PRIu64" from cache", + inode->inum); + if (g_hash_table_remove(fs->inodes, &inode->inum)) + bluesky_inode_unref(inode); + } g_mutex_unlock(fs->lock); } } -- 2.20.1