lkml.org 
[lkml]   [2013]   [May]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 2/2] documentation: Document the is_dirty_writeback aops callback
Date
Subject says it all.

Signed-off-by: Mel Gorman <mgorman@suse.de>
---
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


\
 
 \ /
  Last update: 2013-05-30 12:41    [W:0.031 / U:0.060 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site