diff options
| author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2006-03-20 13:44:04 -0500 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2006-03-20 13:44:04 -0500 |
| commit | cd52ed35535ef443f08bf5cd3331d350272885b8 (patch) | |
| tree | 135c3a80b21ce478816229dc82586b12754eb49f | |
| parent | b92dccf65bab3b6b7deb79ff3321dc256eb0f53b (diff) | |
NFS: Avoid races between writebacks and truncation
Currently, there is no serialisation between NFS asynchronous writebacks
and truncation at the page level due to the fact that nfs_sync_inode()
cannot lock the pages that it is about to write out.
This means that it is possible to be flushing out data (and calling something
like set_page_writeback()) while the page cache is busy evicting the page.
Oops...
Use the hooks provided in try_to_release_page() to ensure that dirty pages
are always written back to storage before we evict them.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
| -rw-r--r-- | fs/nfs/file.c | 13 | ||||
| -rw-r--r-- | fs/nfs/pagelist.c | 10 |
2 files changed, 21 insertions, 2 deletions
diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 7a79fbe9f53..387809f2d18 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -316,6 +316,17 @@ static int nfs_commit_write(struct file *file, struct page *page, unsigned offse return status; } +static int nfs_invalidate_page(struct page *page, unsigned long offset) +{ + /* FIXME: we really should cancel any unstarted writes on this page */ + return 1; +} + +static int nfs_release_page(struct page *page, gfp_t gfp) +{ + return !nfs_wb_page(page->mapping->host, page); +} + struct address_space_operations nfs_file_aops = { .readpage = nfs_readpage, .readpages = nfs_readpages, @@ -324,6 +335,8 @@ struct address_space_operations nfs_file_aops = { .writepages = nfs_writepages, .prepare_write = nfs_prepare_write, .commit_write = nfs_commit_write, + .invalidatepage = nfs_invalidate_page, + .releasepage = nfs_release_page, #ifdef CONFIG_NFS_DIRECTIO .direct_IO = nfs_direct_IO, #endif diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index d53857b148e..d6e076c9dbe 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -85,6 +85,10 @@ nfs_create_request(struct nfs_open_context *ctx, struct inode *inode, atomic_set(&req->wb_complete, 0); req->wb_index = page->index; page_cache_get(page); + BUG_ON(PagePrivate(page)); + BUG_ON(!PageLocked(page)); + BUG_ON(page->mapping->host != inode); + SetPagePrivate(page); req->wb_offset = offset; req->wb_pgbase = offset; req->wb_bytes = count; @@ -147,8 +151,10 @@ void nfs_clear_page_writeback(struct nfs_page *req) */ void nfs_clear_request(struct nfs_page *req) { - if (req->wb_page) { - page_cache_release(req->wb_page); + struct page *page = req->wb_page; + if (page != NULL) { + ClearPagePrivate(page); + page_cache_release(page); req->wb_page = NULL; } } |