From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mel Gorman Subject: [PATCH 2/2] documentation: Document the is_dirty_writeback aops callback Date: Thu, 30 May 2013 11:05:48 +0100 Message-ID: <1369908348-7943-3-git-send-email-mgorman@suse.de> References: <1369908348-7943-1-git-send-email-mgorman@suse.de> Cc: Jiri Slaby , Valdis Kletnieks , Rik van Riel , Zlatko Calusic , Johannes Weiner , dormando , Michal Hocko , Jan Kara , Dave Chinner , Kamezawa Hiroyuki , Linux-FSDevel , Linux-MM , LKML , Mel Gorman To: Andrew Morton Return-path: In-Reply-To: <1369908348-7943-1-git-send-email-mgorman@suse.de> Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org Subject says it all. Signed-off-by: Mel Gorman --- Documentation/filesystems/vfs.txt | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index a173cb7..6b26c75 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -577,6 +577,7 @@ struct address_space_operations { int (*launder_page) (struct page *); int (*is_partially_uptodate) (struct page *, read_descriptor_t *, unsigned long); + void (*is_dirty_writeback) (struct page *, bool *, bool *); int (*error_remove_page) (struct mapping *mapping, struct page *page); int (*swap_activate)(struct file *); int (*swap_deactivate)(struct file *); @@ -741,6 +742,15 @@ struct address_space_operations { block is up to date then the read can complete without needing the IO to bring the whole page up to date. + is_dirty_writeback: Called by the VM when attempting to reclaim a page. + The VM uses dirty and writeback information to determine if it needs + to stall to allow flushers a chance to complete some IO. Ordinarily + it can use PageDirty and PageWriteback but some filesystems have + more complex state (unstable pages in NFS prevent reclaim) or + do not set those flags due to locking problems (jbd). This callback + allows a filesystem to indicate to the VM if a page should be + treated as dirty or writeback for the purposes of stalling. + error_remove_page: normally set to generic_error_remove_page if truncation is ok for this address space. Used for memory failure handling. Setting this implies you deal with pages going away under you, -- 1.8.1.4 -- 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: email@kvack.org