[lustre-devel] [PATCH 11/32] lustre: som: disabling xattr cache for LSOM on client

[James Simmons]

From: Qian Yingjin <qian at ddn.com>

To obtain uptodate LSOM data, currently a client needs to set
llite.*.xattr_cache =0 to disable the xattr cache on client
completely. This leads that other kinds of xattr can not be cached
on the client too.
This patch introduces a heavy-weight solution to disable caching
only for LSOM xattr data ("trusted.som") on client.

WC-bug-id: https://jira.whamcloud.com/browse/LU-11695
Lustre-commit: 192902851d73ec246 ("LU-11695 som: disabling xattr cache for LSOM on client")
Signed-off-by: Qian Yingjin <qian at ddn.com>
Reviewed-on: https://review.whamcloud.com/33711
Reviewed-by: Andreas Dilger <adilger at whamcloud.com>
Reviewed-by: Li Xi <lixi at ddn.com>
Reviewed-by: Oleg Drokin <green at whamcloud.com>
Signed-off-by: James Simmons <jsimmons at infradead.org>
---
 fs/lustre/llite/xattr.c       | 3 ++-
 fs/lustre/llite/xattr_cache.c | 4 ++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/lustre/llite/xattr.c b/fs/lustre/llite/xattr.c
index 3a342ad..11310f9 100644
--- a/fs/lustre/llite/xattr.c
+++ b/fs/lustre/llite/xattr.c
@@ -373,7 +373,8 @@ int ll_xattr_list(struct inode *inode, const char *name, int type, void *buffer,
 	}
 
 	if (sbi->ll_xattr_cache_enabled && type != XATTR_ACL_ACCESS_T &&
-	    (type != XATTR_SECURITY_T || strcmp(name, "security.selinux"))) {
+	    (type != XATTR_SECURITY_T || strcmp(name, "security.selinux")) &&
+	    (type != XATTR_TRUSTED_T || strcmp(name, XATTR_NAME_SOM))) {
 		rc = ll_xattr_cache_get(inode, name, buffer, size, valid);
 		if (rc == -EAGAIN)
 			goto getxattr_nocache;
diff --git a/fs/lustre/llite/xattr_cache.c b/fs/lustre/llite/xattr_cache.c
index 723cc39..7e5b807 100644
--- a/fs/lustre/llite/xattr_cache.c
+++ b/fs/lustre/llite/xattr_cache.c
@@ -465,6 +465,10 @@ static int ll_xattr_cache_refill(struct inode *inode)
 			/* Filter out security.selinux, it is cached in slab */
 			CDEBUG(D_CACHE, "not caching security.selinux\n");
 			rc = 0;
+		} else if (!strcmp(xdata, XATTR_NAME_SOM)) {
+			/* Filter out trusted.som, it is not cached on client */
+			CDEBUG(D_CACHE, "not caching trusted.som\n");
+			rc = 0;
 		} else {
 			rc = ll_xattr_cache_add(&lli->lli_xattrs, xdata, xval,
 						*xsizes);
-- 
1.8.3.1