Merge branch 'net-2.6.26-isatap-20080403' of git://git.linux-ipv6.org/gitroot/yoshfuj...

[linux-2.6] / fs / nfs / write.c

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 5ac5b27b639a85decb94b5d49c72aeb46361a9ff..bed63416a55b3c51ab539666c4f3f5f5ca8321b0 100644 (file)
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -39,6 +39,7 @@ static struct nfs_page * nfs_update_request(struct nfs_open_context*,
                                            unsigned int, unsigned int);
 static void nfs_pageio_init_write(struct nfs_pageio_descriptor *desc,
                                  struct inode *inode, int ioflags);
+static void nfs_redirty_request(struct nfs_page *req);
 static const struct rpc_call_ops nfs_write_partial_ops;
 static const struct rpc_call_ops nfs_write_full_ops;
 static const struct rpc_call_ops nfs_commit_ops;
@@ -288,7 +289,12 @@ static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio,
                BUG();
        }
        spin_unlock(&inode->i_lock);
-       nfs_pageio_add_request(pgio, req);
+       if (!nfs_pageio_add_request(pgio, req)) {
+               nfs_redirty_request(req);
+               nfs_end_page_writeback(page);
+               nfs_clear_page_tag_locked(req);
+               return pgio->pg_error;
+       }
        return 0;
 }
 
@@ -488,7 +494,7 @@ int nfs_reschedule_unstable_write(struct nfs_page *req)
 /*
  * Wait for a request to complete.
  *
- * Interruptible by signals only if mounted with intr flag.
+ * Interruptible by fatal signals only.
  */
 static int nfs_wait_on_requests_locked(struct inode *inode, pgoff_t idx_start, unsigned int npages)
 {
@@ -665,9 +671,7 @@ zero_page:
         * then we need to zero any uninitalised data. */
        if (req->wb_pgbase == 0 && req->wb_bytes != PAGE_CACHE_SIZE
                        && !PageUptodate(req->wb_page))
-               zero_user_page(req->wb_page, req->wb_bytes,
-                               PAGE_CACHE_SIZE - req->wb_bytes,
-                               KM_USER0);
+               zero_user_segment(req->wb_page, req->wb_bytes, PAGE_CACHE_SIZE);
        return req;
 }
 
@@ -698,6 +702,17 @@ int nfs_flush_incompatible(struct file *file, struct page *page)
        return status;
 }
 
+/*
+ * If the page cache is marked as unsafe or invalid, then we can't rely on
+ * the PageUptodate() flag. In this case, we will need to turn off
+ * write optimisations that depend on the page contents being correct.
+ */
+static int nfs_write_pageuptodate(struct page *page, struct inode *inode)
+{
+       return PageUptodate(page) &&
+               !(NFS_I(inode)->cache_validity & (NFS_INO_REVAL_PAGECACHE|NFS_INO_INVALID_DATA));
+}
+
 /*
  * Update and possibly write a cached page of an NFS file.
  *
@@ -719,10 +734,13 @@ int nfs_updatepage(struct file *file, struct page *page,
                (long long)(page_offset(page) +offset));
 
        /* If we're not using byte range locks, and we know the page
-        * is entirely in cache, it may be more efficient to avoid
-        * fragmenting write requests.
+        * is up to date, it may be more efficient to extend the write
+        * to cover the entire page in order to avoid fragmentation
+        * inefficiencies.
         */
-       if (PageUptodate(page) && inode->i_flock == NULL && !(file->f_mode & O_SYNC)) {
+       if (nfs_write_pageuptodate(page, inode) &&
+                       inode->i_flock == NULL &&
+                       !(file->f_flags & O_SYNC)) {
                count = max(count + offset, nfs_page_length(page));
                offset = 0;
        }