The patch titled
Subject: mm/filemap.c: rewrite mapping_needs_writeback in less fancy manner
has been added to the -mm tree. Its filename is
mm-filemap-rewrite-mapping_needs_writeback-in-less-fancy-manner.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-filemap-rewrite-mapping_needs_writeback-in-less-fancy-manner.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-filemap-rewrite-mapping_needs_writeback-in-less-fancy-manner.patch
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------------------------------------------------------
From: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>
Subject: mm/filemap.c: rewrite mapping_needs_writeback in less fancy manner
This actually checks that writeback is needed or in progress.
Link: http://lkml.kernel.org/r/156378817069.1087.1302816672037672488.stgit@buzz
Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/filemap.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
--- a/mm/filemap.c~mm-filemap-rewrite-mapping_needs_writeback-in-less-fancy-manner
+++ a/mm/filemap.c
@@ -617,10 +617,13 @@ int filemap_fdatawait_keep_errors(struct
}
EXPORT_SYMBOL(filemap_fdatawait_keep_errors);
+/* Returns true if writeback might be needed or already in progress. */
static bool mapping_needs_writeback(struct address_space *mapping)
{
- return (!dax_mapping(mapping) && mapping->nrpages) ||
- (dax_mapping(mapping) && mapping->nrexceptional);
+ if (dax_mapping(mapping))
+ return mapping->nrexceptional;
+
+ return mapping->nrpages;
}
int filemap_write_and_wait(struct address_space *mapping)
_
Patches currently in -mm which might be from khlebnikov@xxxxxxxxxxxxxx are
mm-filemap-rewrite-mapping_needs_writeback-in-less-fancy-manner.patch
mm-filemap-dont-initiate-writeback-if-mapping-has-no-dirty-pages.patch
