Merge branch 'master' of /home/trondmy/kernel/linux-2.6/ into merge_linus
[linux-2.6.git] / fs / nfs / pagelist.c
index 3fbfc2f..ca4b1d4 100644 (file)
@@ -17,6 +17,7 @@
 #include <linux/nfs_page.h>
 #include <linux/nfs_fs.h>
 #include <linux/nfs_mount.h>
+#include <linux/writeback.h>
 
 #define NFS_PARANOIA 1
 
@@ -268,11 +269,10 @@ nfs_coalesce_requests(struct list_head *head, struct list_head *dst,
 
 #define NFS_SCAN_MAXENTRIES 16
 /**
- * nfs_scan_lock_dirty - Scan the radix tree for dirty requests
- * @nfsi: NFS inode
+ * nfs_scan_dirty - Scan the radix tree for dirty requests
+ * @mapping: pointer to address space
+ * @wbc: writeback_control structure
  * @dst: Destination list
- * @idx_start: lower bound of page->index to scan
- * @npages: idx_start + npages sets the upper bound to scan.
  *
  * Moves elements from one of the inode request lists.
  * If the number of requests is set to 0, the entire address_space
@@ -280,46 +280,63 @@ nfs_coalesce_requests(struct list_head *head, struct list_head *dst,
  * 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_lock_dirty(struct nfs_inode *nfsi, struct list_head *dst,
-             unsigned long idx_start, unsigned int npages)
+long nfs_scan_dirty(struct address_space *mapping,
+                       struct writeback_control *wbc,
+                       struct list_head *dst)
 {
+       struct nfs_inode *nfsi = NFS_I(mapping->host);
        struct nfs_page *pgvec[NFS_SCAN_MAXENTRIES];
        struct nfs_page *req;
-       unsigned long idx_end;
+       pgoff_t idx_start, idx_end;
+       long res = 0;
        int found, i;
-       int res;
 
-       res = 0;
-       if (npages == 0)
-               idx_end = ~0;
-       else
-               idx_end = idx_start + npages - 1;
+       if (nfsi->ndirty == 0)
+               return 0;
+       if (wbc->range_cyclic) {
+               idx_start = 0;
+               idx_end = ULONG_MAX;
+       } else if (wbc->range_end == 0) {
+               idx_start = wbc->range_start >> PAGE_CACHE_SHIFT;
+               idx_end = ULONG_MAX;
+       } else {
+               idx_start = wbc->range_start >> PAGE_CACHE_SHIFT;
+               idx_end = wbc->range_end >> PAGE_CACHE_SHIFT;
+       }
 
        for (;;) {
+               unsigned int toscan = NFS_SCAN_MAXENTRIES;
+
                found = radix_tree_gang_lookup_tag(&nfsi->nfs_page_tree,
-                               (void **)&pgvec[0], idx_start, NFS_SCAN_MAXENTRIES,
+                               (void **)&pgvec[0], idx_start, toscan,
                                NFS_PAGE_TAG_DIRTY);
+
+               /* Did we make progress? */
                if (found <= 0)
                        break;
+
                for (i = 0; i < found; i++) {
                        req = pgvec[i];
-                       if (req->wb_index > idx_end)
+                       if (!wbc->range_cyclic && req->wb_index > idx_end)
                                goto out;
 
+                       /* Try to lock request and mark it for writeback */
+                       if (!nfs_set_page_writeback_locked(req))
+                               goto next;
+                       radix_tree_tag_clear(&nfsi->nfs_page_tree,
+                                       req->wb_index, NFS_PAGE_TAG_DIRTY);
+                       nfsi->ndirty--;
+                       nfs_list_remove_request(req);
+                       nfs_list_add_request(req, dst);
+                       res++;
+                       if (res == LONG_MAX)
+                               goto out;
+next:
                        idx_start = req->wb_index + 1;
-
-                       if (nfs_set_page_writeback_locked(req)) {
-                               radix_tree_tag_clear(&nfsi->nfs_page_tree,
-                                               req->wb_index, NFS_PAGE_TAG_DIRTY);
-                               nfs_list_remove_request(req);
-                               nfs_list_add_request(req, dst);
-                               dec_zone_page_state(req->wb_page, NR_FILE_DIRTY);
-                               res++;
-                       }
                }
        }
 out:
+       WARN_ON ((nfsi->ndirty == 0) != list_empty(&nfsi->dirty));
        return res;
 }