[lustre-devel] [PATCH 04/27] lustre: llite: improve readpage debug

[James Simmons]

From: Patrick Farrell <pfarrell at whamcloud.com>

LU-16412 (which is a workaround for a kernel bug) added a
debug message in ll_readpage(), but this message is printed
every time rather than only when the kernel bug is hit.

Let's fix this.

Fixes: aaa089da3f ("lustre: llite: check truncated page in ->readpage()")
WC-bug-id: https://jira.whamcloud.com/browse/LU-16805
Lustre-commit: c2f548dacc5fd7285 ("LU-16805 llite: improve readpage debug")
Signed-off-by: Patrick Farrell <pfarrell at whamcloud.com>
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/50892
Reviewed-by: Andreas Dilger <adilger at whamcloud.com>
Reviewed-by: Timothy Day <timday at amazon.com>
Reviewed-by: Oleg Drokin <green at whamcloud.com>
Signed-off-by: James Simmons <jsimmons at infradead.org>
---
 fs/lustre/llite/rw.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/fs/lustre/llite/rw.c b/fs/lustre/llite/rw.c
index 276cad2b6eb7..e258d995c54b 100644
--- a/fs/lustre/llite/rw.c
+++ b/fs/lustre/llite/rw.c
@@ -1981,9 +1981,6 @@ int ll_readpage(struct file *file, struct page *vmpage)
 	}
 
 	if (lcc && lcc->lcc_type != LCC_MMAP) {
-		CDEBUG(D_VFSTRACE, "pgno:%ld, beyond read end_index:%ld\n",
-		       vmpage->index, lcc->lcc_end_index);
-
 		/*
 		 * This handles a kernel bug introduced in kernel 5.12:
 		 * comment: cbd59c48ae2bcadc4a7599c29cf32fd3f9b78251
@@ -2009,6 +2006,10 @@ int ll_readpage(struct file *file, struct page *vmpage)
 		 * mentioned above.
 		 */
 		if (vmpage->index >= lcc->lcc_end_index) {
+			CDEBUG(D_VFSTRACE,
+			       "pgno:%ld, beyond read end_index:%ld\n",
+			       vmpage->index, lcc->lcc_end_index);
+
 			result = cl_io_read_ahead(env, io, vmpage->index, &ra);
 			if (result < 0 || vmpage->index > ra.cra_end_idx) {
 				cl_read_ahead_release(env, &ra);
-- 
2.39.3