VisionFive2 Linux kernel

StarFive Tech Linux Kernel for VisionFive (JH7110) boards (mirror)

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author: zhangyi (F) <yi.zhang@huawei.com> 2020-02-13 14:38:21 +0800 committer: Theodore Ts'o <tytso@mit.edu> 2020-02-13 12:06:28 -0500 commit: c96dceeabf765d0b1b1f29c3bf50a5c01315b820 parent: 6a66a7ded12baa6ebbb2e3e82f8cb91382814839
Commit Summary:
jbd2: do not clear the BH_Mapped flag when forgetting a metadata buffer
Diffstat:
1 file changed, 20 insertions, 4 deletions
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 6396fe70085b..27373f5792a4 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -985,12 +985,29 @@ restart_loop:
 		 * pagesize and it is attached to the last partial page.
 		 */
 		if (buffer_freed(bh) && !jh->b_next_transaction) {
+			struct address_space *mapping;
+
 			clear_buffer_freed(bh);
 			clear_buffer_jbddirty(bh);
-			clear_buffer_mapped(bh);
-			clear_buffer_new(bh);
-			clear_buffer_req(bh);
-			bh->b_bdev = NULL;
+
+			/*
+			 * Block device buffers need to stay mapped all the
+			 * time, so it is enough to clear buffer_jbddirty and
+			 * buffer_freed bits. For the file mapping buffers (i.e.
+			 * journalled data) we need to unmap buffer and clear
+			 * more bits. We also need to be careful about the check
+			 * because the data page mapping can get cleared under
+			 * out hands, which alse need not to clear more bits
+			 * because the page and buffers will be freed and can
+			 * never be reused once we are done with them.
+			 */
+			mapping = READ_ONCE(bh->b_page->mapping);
+			if (mapping && !sb_is_blkdev_sb(mapping->host->i_sb)) {
+				clear_buffer_mapped(bh);
+				clear_buffer_new(bh);
+				clear_buffer_req(bh);
+				bh->b_bdev = NULL;
+			}
 		}
 
 		if (buffer_jbddirty(bh)) {