diff options
| -rw-r--r-- | include/linux/writeback.h | 9 | ||||
| -rw-r--r-- | mm/page-writeback.c | 10 |
2 files changed, 16 insertions, 3 deletions
diff --git a/include/linux/writeback.h b/include/linux/writeback.h index bd91987c065..e585657e983 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -63,6 +63,15 @@ struct writeback_control { unsigned for_writepages:1; /* This is a writepages() call */ unsigned range_cyclic:1; /* range_start is cyclic */ unsigned more_io:1; /* more io to be dispatched */ + /* + * write_cache_pages() won't update wbc->nr_to_write and + * mapping->writeback_index if no_nrwrite_index_update + * is set. write_cache_pages() may write more than we + * requested and we want to make sure nr_to_write and + * writeback_index are updated in a consistent manner + * so we use a single control to update them + */ + unsigned no_nrwrite_index_update:1; }; /* diff --git a/mm/page-writeback.c b/mm/page-writeback.c index e373f14d26f..b40f6d5f8fe 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -876,6 +876,7 @@ int write_cache_pages(struct address_space *mapping, pgoff_t end; /* Inclusive */ int scanned = 0; int range_whole = 0; + long nr_to_write = wbc->nr_to_write; if (wbc->nonblocking && bdi_write_congested(bdi)) { wbc->encountered_congestion = 1; @@ -939,7 +940,7 @@ retry: unlock_page(page); ret = 0; } - if (ret || (--(wbc->nr_to_write) <= 0)) + if (ret || (--nr_to_write <= 0)) done = 1; if (wbc->nonblocking && bdi_write_congested(bdi)) { wbc->encountered_congestion = 1; @@ -958,8 +959,11 @@ retry: index = 0; goto retry; } - if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) - mapping->writeback_index = index; + if (!wbc->no_nrwrite_index_update) { + if (wbc->range_cyclic || (range_whole && nr_to_write > 0)) + mapping->writeback_index = index; + wbc->nr_to_write = nr_to_write; + } return ret; } |