Merge branches 'release', 'button-sysfs', 'misc', 'mismatch', 'randconfig' and 'toshi...

[linux-2.6-omap-h63xx.git] / fs / nfs / write.c

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 5ac5b27b639a85decb94b5d49c72aeb46361a9ff..80c61fdb2720c4b05f86ff7c590cd0af566e2b8d 100644 (file)
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -488,7 +488,7 @@ 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 +665,7 @@ 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 +696,17 @@ 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 +728,13 @@ 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;
        }