NFS: Flesh out nfs_invalidate_page()

In the case of a call to truncate_inode_pages(), we should really try to
cancel any pending writes on the page.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 6315407..106ef0d 100644 (file)
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -303,7 +303,11 @@ static int nfs_commit_write(struct file *file, struct page *page, unsigned offse
 
 static void nfs_invalidate_page(struct page *page, unsigned long offset)
 {
-       /* FIXME: we really should cancel any unstarted writes on this page */
+       struct inode *inode = page->mapping->host;
+
+       /* Cancel any unstarted writes on this page */
+       if (offset == 0)
+               nfs_sync_inode_wait(inode, page->index, 1, FLUSH_INVALIDATE);
 }
 
 static int nfs_release_page(struct page *page, gfp_t gfp)

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 106aca3..656481c 100644 (file)
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -325,6 +325,7 @@ out:
 
 /**
  * nfs_scan_list - Scan a list for matching requests
+ * @nfsi: NFS inode
  * @head: One of the NFS inode request lists
  * @dst: Destination list
  * @idx_start: lower bound of page->index to scan
@@ -336,14 +337,15 @@ out:
  * The requests are *not* checked to ensure that they form a contiguous set.
  * You must be holding the inode's req_lock when calling this function
  */
-int
-nfs_scan_list(struct list_head *head, struct list_head *dst,
-             unsigned long idx_start, unsigned int npages)
+int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *head,
+               struct list_head *dst, unsigned long idx_start,
+               unsigned int npages)
 {
-       struct list_head        *pos, *tmp;
-       struct nfs_page         *req;
-       unsigned long           idx_end;
-       int                     res;
+       struct nfs_page *pgvec[NFS_SCAN_MAXENTRIES];
+       struct nfs_page *req;
+       unsigned long idx_end;
+       int found, i;
+       int res;
 
        res = 0;
        if (npages == 0)
@@ -351,21 +353,28 @@ nfs_scan_list(struct list_head *head, struct list_head *dst,
        else
                idx_end = idx_start + npages - 1;
 
-       list_for_each_safe(pos, tmp, head) {
-
-               req = nfs_list_entry(pos);
-
-               if (req->wb_index < idx_start)
-                       continue;
-               if (req->wb_index > idx_end)
+       for (;;) {
+               found = radix_tree_gang_lookup(&nfsi->nfs_page_tree,
+                               (void **)&pgvec[0], idx_start,
+                               NFS_SCAN_MAXENTRIES);
+               if (found <= 0)
                        break;
+               for (i = 0; i < found; i++) {
+                       req = pgvec[i];
+                       if (req->wb_index > idx_end)
+                               goto out;
+                       idx_start = req->wb_index + 1;
+                       if (req->wb_list_head != head)
+                               continue;
+                       if (nfs_set_page_writeback_locked(req)) {
+                               nfs_list_remove_request(req);
+                               nfs_list_add_request(req, dst);
+                               res++;
+                       }
+               }
 
-               if (!nfs_set_page_writeback_locked(req))
-                       continue;
-               nfs_list_remove_request(req);
-               nfs_list_add_request(req, dst);
-               res++;
        }
+out:
        return res;
 }
 

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index a515ec7..e03abbd 100644 (file)
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -579,6 +579,17 @@ static int nfs_wait_on_requests(struct inode *inode, unsigned long idx_start, un
        return ret;
 }
 
+static void nfs_cancel_requests(struct list_head *head)
+{
+       struct nfs_page *req;
+       while(!list_empty(head)) {
+               req = nfs_list_entry(head->next);
+               nfs_list_remove_request(req);
+               nfs_inode_remove_request(req);
+               nfs_clear_page_writeback(req);
+       }
+}
+
 /*
  * nfs_scan_dirty - Scan an inode for dirty requests
  * @inode: NFS inode to scan
@@ -623,7 +634,7 @@ nfs_scan_commit(struct inode *inode, struct list_head *dst, unsigned long idx_st
        int res = 0;
 
        if (nfsi->ncommit != 0) {
-               res = nfs_scan_list(&nfsi->commit, dst, idx_start, npages);
+               res = nfs_scan_list(nfsi, &nfsi->commit, dst, idx_start, npages);
                nfsi->ncommit -= res;
                if ((nfsi->ncommit == 0) != list_empty(&nfsi->commit))
                        printk(KERN_ERR "NFS: desynchronized value of nfs_i.ncommit.\n");
@@ -1491,15 +1502,25 @@ int nfs_sync_inode_wait(struct inode *inode, unsigned long idx_start,
                pages = nfs_scan_dirty(inode, &head, idx_start, npages);
                if (pages != 0) {
                        spin_unlock(&nfsi->req_lock);
-                       ret = nfs_flush_list(inode, &head, pages, how);
+                       if (how & FLUSH_INVALIDATE)
+                               nfs_cancel_requests(&head);
+                       else
+                               ret = nfs_flush_list(inode, &head, pages, how);
                        spin_lock(&nfsi->req_lock);
                        continue;
                }
                if (nocommit)
                        break;
-               pages = nfs_scan_commit(inode, &head, 0, 0);
+               pages = nfs_scan_commit(inode, &head, idx_start, npages);
                if (pages == 0)
                        break;
+               if (how & FLUSH_INVALIDATE) {
+                       spin_unlock(&nfsi->req_lock);
+                       nfs_cancel_requests(&head);
+                       spin_lock(&nfsi->req_lock);
+                       continue;
+               }
+               pages += nfs_scan_commit(inode, &head, 0, 0);
                spin_unlock(&nfsi->req_lock);
                ret = nfs_commit_list(inode, &head, how);
                spin_lock(&nfsi->req_lock);

diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 1b524b9..fc48135 100644 (file)
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -61,6 +61,7 @@
 #define FLUSH_LOWPRI           8       /* low priority background flush */
 #define FLUSH_HIGHPRI          16      /* high priority memory reclaim flush */
 #define FLUSH_NOCOMMIT         32      /* Don't send the NFSv3/v4 COMMIT */
+#define FLUSH_INVALIDATE       64      /* Invalidate the page cache */
 
 #ifdef __KERNEL__
 

diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h
index 66e2ed6..8cadb0a 100644 (file)
--- a/include/linux/nfs_page.h
+++ b/include/linux/nfs_page.h
@@ -63,8 +63,8 @@ extern        void nfs_release_request(struct nfs_page *req);
 
 extern  int nfs_scan_lock_dirty(struct nfs_inode *nfsi, struct list_head *dst,
                                unsigned long idx_start, unsigned int npages);
-extern int nfs_scan_list(struct list_head *, struct list_head *,
-                         unsigned long, unsigned int);
+extern int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *head, struct list_head *dst,
+                         unsigned long idx_start, unsigned int npages);
 extern int nfs_coalesce_requests(struct list_head *, struct list_head *,
                                  unsigned int);
 extern  int nfs_wait_on_request(struct nfs_page *);