From: Jan Kara <jack@xxxxxxx> Subject: fs/dax.c: fix inefficiency in dax_writeback_mapping_range() dax_writeback_mapping_range() fails to update iteration index when searching radix tree for entries needing cache flushing. Thus each pagevec worth of entries is searched starting from the start which is inefficient and prone to livelocks. Update index properly. Link: http://lkml.kernel.org/r/20170619124531.21491-1-jack@xxxxxxx Fixes: 9973c98ecfda3 ("dax: add support for fsync/sync") Signed-off-by: Jan Kara <jack@xxxxxxx> Reviewed-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/dax.c | 1 + 1 file changed, 1 insertion(+) diff -puN fs/dax.c~dax-fix-inefficiency-in-dax_writeback_mapping_range fs/dax.c --- a/fs/dax.c~dax-fix-inefficiency-in-dax_writeback_mapping_range +++ a/fs/dax.c @@ -859,6 +859,7 @@ int dax_writeback_mapping_range(struct a if (ret < 0) goto out; } + start_index = indices[pvec.nr - 1] + 1; } out: put_dax(dax_dev); _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
