The documentation for address_space_operations is partially out of date.
Signed-off-by: Mel Gorman <mgorman@xxxxxxx>
---
Documentation/filesystems/vfs.txt | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index bc4b06b..a173cb7 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -549,12 +549,11 @@ struct address_space_operations
-------------------------------
This describes how the VFS can manipulate mapping of a file to page cache in
-your filesystem. As of kernel 2.6.22, the following members are defined:
+your filesystem. At the time of writing, the following members are defined:
struct address_space_operations {
int (*writepage)(struct page *page, struct writeback_control *wbc);
int (*readpage)(struct file *, struct page *);
- int (*sync_page)(struct page *);
int (*writepages)(struct address_space *, struct writeback_control *);
int (*set_page_dirty)(struct page *page);
int (*readpages)(struct file *filp, struct address_space *mapping,
@@ -576,6 +575,8 @@ struct address_space_operations {
/* migrate the contents of a page to the specified target */
int (*migratepage) (struct page *, struct page *);
int (*launder_page) (struct page *);
+ int (*is_partially_uptodate) (struct page *, read_descriptor_t *,
+ unsigned long);
int (*error_remove_page) (struct mapping *mapping, struct page *page);
int (*swap_activate)(struct file *);
int (*swap_deactivate)(struct file *);
@@ -607,13 +608,6 @@ struct address_space_operations {
In this case, the page will be relocated, relocked and if
that all succeeds, ->readpage will be called again.
- sync_page: called by the VM to notify the backing store to perform all
- queued I/O operations for a page. I/O operations for other pages
- associated with this address_space object may also be performed.
-
- This function is optional and is called only for pages with
- PG_Writeback set while waiting for the writeback to complete.
-
writepages: called by the VM to write out pages associated with the
address_space object. If wbc->sync_mode is WBC_SYNC_ALL, then
the writeback_control will specify a range of pages that must be
@@ -742,6 +736,11 @@ struct address_space_operations {
prevent redirtying the page, it is kept locked during the whole
operation.
+ is_partially_uptodate: Called by the VM when reading a file through the
+ pagecache when the underlying blocksize != pagesize. If the required
+ block is up to date then the read can complete without needing the IO
+ to bring the whole page up to date.
+
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
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