Re: [PATCH 2/3] mm: Only enforce stable page writes if the backing device requires it
From: Jan Kara <jack@suse.cz>
Date: 2012-11-01 13:28:46
Also in:
ceph-devel, linux-cifs, linux-ext4, linux-fsdevel, lkml
On Thu 01-11-12 00:58:21, Darrick J. Wong wrote:
Create a helper function to check if a backing device requires stable page writes and, if so, performs the necessary wait. Then, make it so that all points in the memory manager that handle making pages writable use the helper function. This should provide stable page write support to most filesystems, while eliminating unnecessary waiting for devices that don't require the feature. Signed-off-by: Darrick J. Wong <redacted> --- fs/buffer.c | 2 +- fs/ext4/inode.c | 2 +- include/linux/pagemap.h | 1 + mm/filemap.c | 3 ++- mm/page-writeback.c | 11 +++++++++++ 5 files changed, 16 insertions(+), 3 deletions(-)
..
quoted hunk
diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 830893b..916dae1 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c@@ -2275,3 +2275,14 @@ int mapping_tagged(struct address_space *mapping, int tag) return radix_tree_tagged(&mapping->page_tree, tag); } EXPORT_SYMBOL(mapping_tagged); + +void wait_on_stable_page_write(struct page *page) +{ + struct backing_dev_info *bdi = page->mapping->backing_dev_info; + + if (!bdi_cap_stable_pages_required(bdi)) + return; + + wait_on_page_writeback(page); +} +EXPORT_SYMBOL_GPL(wait_on_stable_page_write);
Just one nit: Maybe "wait_if_stable_write()" would describe the function better? Otherwise the patch looks OK. Honza -- Jan Kara [off-list ref] SUSE Labs, CR -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>