From: Qian Yingjin <qian@ddn.com>
Date: Mon, 26 Oct 2020 02:37:26 +0000 (+0800)
Subject: LU-13745 pcc: fall back normal splice read for detached file
X-Git-Tag: 2.14.0-RC1~50
X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=commitdiff_plain;h=cca45ad8aeaa8e124e9e48361bf7cff89a035f82;ds=sidebyside

LU-13745 pcc: fall back normal splice read for detached file

For the file that was once cached into PCC but detached from PCC
later, it should fall back into the normal I/O path to direct I/Os
to Lustre OSTs for splice read, not just return zero.

Signed-off-by: Qian Yingjin <qian@ddn.com>
Change-Id: Iff3449069a0a12ac56b58618e474749361c31bb7
Reviewed-on: https://review.whamcloud.com/40396
Reviewed-by: James Simmons <jsimmons@infradead.org>
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
---

diff --git a/lustre/llite/pcc.c b/lustre/llite/pcc.c
index cfad000..c51a735 100644
--- a/lustre/llite/pcc.c
+++ b/lustre/llite/pcc.c
@@ -1806,14 +1806,14 @@ ssize_t pcc_file_splice_read(struct file *in_file, loff_t *ppos,
 
 	ENTRY;
 
-	if (!pcc_file) {
+	if (!pcc_file)
 		RETURN(default_file_splice_read(in_file, ppos, pipe,
-		       count, flags));
-	}
+						count, flags));
 
 	pcc_io_init(inode, PIT_SPLICE_READ, &cached);
 	if (!cached)
-		RETURN(0);
+		RETURN(default_file_splice_read(in_file, ppos, pipe,
+						count, flags));
 
 	result = default_file_splice_read(pcc_file, ppos, pipe, count, flags);