From 145aa3f4b2b29a145939dbaffef95b2b018979a3 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Fri, 28 Jun 2013 09:52:09 +1000 Subject: [PATCH] documentation: update address_space_operations The documentation for address_space_operations is partially out of date. Signed-off-by: Mel Gorman Signed-off-by: Andrew Morton --- Documentation/filesystems/vfs.txt | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index 22c332ac4a75..49254eb5efd1 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -554,7 +554,6 @@ your filesystem. 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, -- 2.39.5