path: root/Documentation/filesystems/vfs.txt
diff options
authorLinus Torvalds <torvalds@linux-foundation.org>2010-12-01 13:35:19 -0500
committerTrond Myklebust <Trond.Myklebust@netapp.com>2010-12-02 09:55:21 -0500
commit6072d13c429373c5d63b69dadbbef40a9b035552 (patch)
treea2bf745efaa4092f2a8d7d9a9b160c2a7a3b303f /Documentation/filesystems/vfs.txt
parent0aded708d125a3ff7e5abaea9c2d9c6d7ebbfdcd (diff)
Call the filesystem back whenever a page is removed from the page cache
NFS needs to be able to release objects that are stored in the page cache once the page itself is no longer visible from the page cache. This patch adds a callback to the address space operations that allows filesystems to perform page cleanups once the page has been removed from the page cache. Original patch by: Linus Torvalds <torvalds@linux-foundation.org> [trondmy: cover the cases of invalidate_inode_pages2() and truncate_inode_pages()] Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'Documentation/filesystems/vfs.txt')
1 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index ed7e5efc06d..3b14a557eca 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -534,6 +534,7 @@ struct address_space_operations {
sector_t (*bmap)(struct address_space *, sector_t);
int (*invalidatepage) (struct page *, unsigned long);
int (*releasepage) (struct page *, int);
+ void (*freepage)(struct page *);
ssize_t (*direct_IO)(int, struct kiocb *, const struct iovec *iov,
loff_t offset, unsigned long nr_segs);
struct page* (*get_xip_page)(struct address_space *, sector_t,
@@ -679,6 +680,12 @@ struct address_space_operations {
need to ensure this. Possibly it can clear the PageUptodate
bit if it cannot free private data yet.
+ freepage: freepage is called once the page is no longer visible in
+ the page cache in order to allow the cleanup of any private
+ data. Since it may be called by the memory reclaimer, it
+ should not assume that the original address_space mapping still
+ exists, and it should not block.
direct_IO: called by the generic read/write routines to perform
direct_IO - that is IO requests which bypass the page cache
and transfer data directly between the storage and the