From 6072d13c429373c5d63b69dadbbef40a9b035552 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Wed, 1 Dec 2010 13:35:19 -0500 Subject: 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 [trondmy: cover the cases of invalidate_inode_pages2() and truncate_inode_pages()] Signed-off-by: Trond Myklebust --- include/linux/fs.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/fs.h b/include/linux/fs.h index c9e06cc70da..090f0eacde2 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -602,6 +602,7 @@ struct address_space_operations { sector_t (*bmap)(struct address_space *, sector_t); void (*invalidatepage) (struct page *, unsigned long); int (*releasepage) (struct page *, gfp_t); + void (*freepage)(struct page *); ssize_t (*direct_IO)(int, struct kiocb *, const struct iovec *iov, loff_t offset, unsigned long nr_segs); int (*get_xip_mem)(struct address_space *, pgoff_t, int, -- cgit v1.2.3 From 11de3b11e08cac26d59e88efaf4e316701883552 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Wed, 1 Dec 2010 14:17:06 -0500 Subject: NFS: Fix a memory leak in nfs_readdir We need to ensure that the entries in the nfs_cache_array get cleared when the page is removed from the page cache. To do so, we use the freepage address_space operation. Change nfs_readdir_clear_array to use kmap_atomic(), so that the function can be safely called from all contexts. Finally, modify the cache_page_release helper to call nfs_readdir_clear_array directly, when dealing with an anonymous page from 'uncached_readdir'. Signed-off-by: Trond Myklebust --- include/linux/nfs_fs.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h index c66fdb7d699..29d504d5d1c 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -401,6 +401,7 @@ extern const struct inode_operations nfs3_file_inode_operations; #endif /* CONFIG_NFS_V3 */ extern const struct file_operations nfs_file_operations; extern const struct address_space_operations nfs_file_aops; +extern const struct address_space_operations nfs_dir_aops; static inline struct nfs_open_context *nfs_file_open_context(struct file *filp) { -- cgit v1.2.3 From 2df485a774ba59c3f43bfe84107672c1d9b731a0 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 7 Dec 2010 22:39:17 -0500 Subject: nfs: remove extraneous and problematic calls to nfs_clear_request When a nfs_page is freed, nfs_free_request is called which also calls nfs_clear_request to clean out the lock and open contexts and free the pagecache page. However, a couple of places in the nfs code call nfs_clear_request themselves. What happens here if the refcount on the request is still high? We'll be releasing contexts and freeing pointers while the request is possibly still in use. Remove those bare calls to nfs_clear_context. That should only be done when the request is being freed. Note that when doing this, we need to watch out for tests of req->wb_page. Previously, nfs_set_page_tag_locked() and nfs_clear_page_tag_locked() would check the value of req->wb_page to figure out if the page is mapped into the nfsi->nfs_page_tree. We now indicate the page is mapped using the new bit PG_MAPPED in req->wb_flags . Reported-by: Jeff Layton Signed-off-by: Trond Myklebust --- include/linux/nfs_page.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h index f8b60e7f4c4..d55cee73f63 100644 --- a/include/linux/nfs_page.h +++ b/include/linux/nfs_page.h @@ -29,6 +29,7 @@ */ enum { PG_BUSY = 0, + PG_MAPPED, PG_CLEAN, PG_NEED_COMMIT, PG_NEED_RESCHED, -- cgit v1.2.3