NFS cleanup: speed up nfs_scan_commit using radix tree tags

Add a tag for requests that are waiting for a COMMIT

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

2 files changed, 12 insertions, 8 deletions

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 23e9dea20902..ad90cbe76703 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -381,10 +381,10 @@ void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index)
 /**
  * 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
  * @npages: idx_start + npages sets the upper bound to scan.
+ * @tag: tag to scan for
  *
  * Moves elements from one of the inode request lists.
  * If the number of requests is set to 0, the entire address_space
@@ -392,9 +392,9 @@ void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index)
  * 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 nfs_inode *nfsi, struct list_head *head,
+int nfs_scan_list(struct nfs_inode *nfsi,
                 struct list_head *dst, pgoff_t idx_start,
-                unsigned int npages)
+                unsigned int npages, int tag)
 {
         struct nfs_page *pgvec[NFS_SCAN_MAXENTRIES];
         struct nfs_page *req;
@@ -409,9 +409,9 @@ int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *head,
                 idx_end = idx_start + npages - 1;
 
         for (;;) {
-                found = radix_tree_gang_lookup(&nfsi->nfs_page_tree,
+                found = radix_tree_gang_lookup_tag(&nfsi->nfs_page_tree,
                                 (void **)&pgvec[0], idx_start,
-                                NFS_SCAN_MAXENTRIES);
+                                NFS_SCAN_MAXENTRIES, tag);
                 if (found <= 0)
                         break;
                 for (i = 0; i < found; i++) {
@@ -419,10 +419,10 @@ int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *head,
                         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_tag_locked(req)) {
                                 nfs_list_remove_request(req);
+                                radix_tree_tag_clear(&nfsi->nfs_page_tree,
+                                                req->wb_index, tag);
                                 nfs_list_add_request(req, dst);
                                 res++;
                         }
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 754066cc9146..0f779ca12ec3 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -462,6 +462,9 @@ nfs_mark_request_commit(struct nfs_page *req)
         nfs_list_add_request(req, &nfsi->commit);
         nfsi->ncommit++;
         set_bit(PG_NEED_COMMIT, &(req)->wb_flags);
+        radix_tree_tag_set(&nfsi->nfs_page_tree,
+                        req->wb_index,
+                        NFS_PAGE_TAG_COMMIT);
         spin_unlock(&nfsi->req_lock);
         inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
         __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
@@ -575,7 +578,8 @@ nfs_scan_commit(struct inode *inode, struct list_head *dst, pgoff_t idx_start, u
         int res = 0;
 
         if (nfsi->ncommit != 0) {
-                res = nfs_scan_list(nfsi, &nfsi->commit, dst, idx_start, npages);
+                res = nfs_scan_list(nfsi, dst, idx_start, npages,
+                                NFS_PAGE_TAG_COMMIT);
                 nfsi->ncommit -= res;
                 if ((nfsi->ncommit == 0) != list_empty(&nfsi->commit))
                         printk(KERN_ERR "NFS: desynchronized value of nfs_i.ncommit.\n");