NFS: remove nfs_inode radix tree

The radix tree is only being used to compile lists of reqs needing commit.
It is simpler to just put the reqs directly into a list.

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

1 files changed, 67 insertions, 53 deletions

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index fd8a4f07bc0c..a630ad65d64c 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -375,21 +375,14 @@ out_err:
 /*
  * Insert a write request into an inode
  */
-static int nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
+static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
 {
         struct nfs_inode *nfsi = NFS_I(inode);
-        int error;
-
-        error = radix_tree_preload(GFP_NOFS);
-        if (error != 0)
-                goto out;
 
         /* Lock the request! */
         nfs_lock_request_dontget(req);
 
         spin_lock(&inode->i_lock);
-        error = radix_tree_insert(&nfsi->nfs_page_tree, req->wb_index, req);
-        BUG_ON(error);
         if (!nfsi->npages && nfs_have_delegation(inode, FMODE_WRITE))
                 inode->i_version++;
         set_bit(PG_MAPPED, &req->wb_flags);
@@ -398,11 +391,10 @@ static int nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
         nfsi->npages++;
         kref_get(&req->wb_kref);
         spin_unlock(&inode->i_lock);
-        radix_tree_preload_end();
-out:
-        return error;
 }
 
+static struct pnfs_layout_segment *nfs_clear_request_commit(struct nfs_page *req);
+
 /*
  * Remove a write request from an inode
  */
@@ -410,16 +402,18 @@ static void nfs_inode_remove_request(struct nfs_page *req)
 {
         struct inode *inode = req->wb_context->dentry->d_inode;
         struct nfs_inode *nfsi = NFS_I(inode);
+        struct pnfs_layout_segment *lseg;
 
         BUG_ON (!NFS_WBACK_BUSY(req));
 
         spin_lock(&inode->i_lock);
+        lseg = nfs_clear_request_commit(req);
         set_page_private(req->wb_page, 0);
         ClearPagePrivate(req->wb_page);
         clear_bit(PG_MAPPED, &req->wb_flags);
-        radix_tree_delete(&nfsi->nfs_page_tree, req->wb_index);
         nfsi->npages--;
         spin_unlock(&inode->i_lock);
+        put_lseg(lseg);
         nfs_release_request(req);
 }
 
@@ -438,31 +432,38 @@ nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg)
 {
         struct inode *inode = req->wb_context->dentry->d_inode;
         struct nfs_inode *nfsi = NFS_I(inode);
+        struct list_head *clist;
 
+        clist = pnfs_choose_commit_list(req, lseg);
         spin_lock(&inode->i_lock);
         set_bit(PG_CLEAN, &(req)->wb_flags);
-        radix_tree_tag_set(&nfsi->nfs_page_tree,
-                        req->wb_index,
-                        NFS_PAGE_TAG_COMMIT);
+        nfs_list_add_request(req, clist);
         nfsi->ncommit++;
         spin_unlock(&inode->i_lock);
-        pnfs_mark_request_commit(req, lseg);
         inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
         inc_bdi_stat(req->wb_page->mapping->backing_dev_info, BDI_RECLAIMABLE);
         __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
 }
 
-static int
+static void
+nfs_clear_page_commit(struct page *page)
+{
+        dec_zone_page_state(page, NR_UNSTABLE_NFS);
+        dec_bdi_stat(page->mapping->backing_dev_info, BDI_RECLAIMABLE);
+}
+
+static struct pnfs_layout_segment *
 nfs_clear_request_commit(struct nfs_page *req)
 {
-        struct page *page = req->wb_page;
+        struct pnfs_layout_segment *lseg = NULL;
 
         if (test_and_clear_bit(PG_CLEAN, &(req)->wb_flags)) {
-                dec_zone_page_state(page, NR_UNSTABLE_NFS);
-                dec_bdi_stat(page->mapping->backing_dev_info, BDI_RECLAIMABLE);
-                return 1;
+                nfs_clear_page_commit(req->wb_page);
+                lseg = pnfs_clear_request_commit(req);
+                NFS_I(req->wb_context->dentry->d_inode)->ncommit--;
+                list_del(&req->wb_list);
         }
-        return 0;
+        return lseg;
 }
 
 static inline
@@ -494,10 +495,10 @@ nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg)
 {
 }
 
-static inline int
+static inline struct pnfs_layout_segment *
 nfs_clear_request_commit(struct nfs_page *req)
 {
-        return 0;
+        return NULL;
 }
 
 static inline
@@ -518,46 +519,67 @@ int nfs_reschedule_unstable_write(struct nfs_page *req,
 static int
 nfs_need_commit(struct nfs_inode *nfsi)
 {
-        return radix_tree_tagged(&nfsi->nfs_page_tree, NFS_PAGE_TAG_COMMIT);
+        return nfsi->ncommit > 0;
 }
 
+/* i_lock held by caller */
+int
+nfs_scan_commit_list(struct list_head *src, struct list_head *dst, int max)
+{
+        struct nfs_page *req, *tmp;
+        int ret = 0;
+
+        list_for_each_entry_safe(req, tmp, src, wb_list) {
+                if (nfs_lock_request_dontget(req)) {
+                        kref_get(&req->wb_kref);
+                        list_move_tail(&req->wb_list, dst);
+                        clear_bit(PG_CLEAN, &(req)->wb_flags);
+                        ret++;
+                        if (ret == max)
+                                break;
+                }
+        }
+        return ret;
+}
+EXPORT_SYMBOL_GPL(nfs_scan_commit_list);
+
 /*
  * nfs_scan_commit - Scan an inode for commit requests
  * @inode: NFS inode to scan
  * @dst: destination list
- * @idx_start: lower bound of page->index to scan.
- * @npages: idx_start + npages sets the upper bound to scan.
  *
  * Moves requests from the inode's 'commit' request list.
  * The requests are *not* checked to ensure that they form a contiguous set.
  */
 static int
-nfs_scan_commit(struct inode *inode, struct list_head *dst, pgoff_t idx_start, unsigned int npages)
+nfs_scan_commit(struct inode *inode, struct list_head *dst)
 {
         struct nfs_inode *nfsi = NFS_I(inode);
-        int ret;
-
-        if (!nfs_need_commit(nfsi))
-                return 0;
+        int ret = 0;
 
         spin_lock(&inode->i_lock);
-        ret = nfs_scan_list(nfsi, dst, idx_start, npages, NFS_PAGE_TAG_COMMIT);
-        if (ret > 0)
+        if (nfsi->ncommit > 0) {
+                int pnfs_ret;
+
+                ret = nfs_scan_commit_list(&nfsi->commit_list, dst, INT_MAX);
+                pnfs_ret = pnfs_scan_commit_lists(inode, INT_MAX - ret);
+                if (pnfs_ret) {
+                        ret += pnfs_ret;
+                        set_bit(NFS_INO_PNFS_COMMIT, &nfsi->flags);
+                }
                 nfsi->ncommit -= ret;
+        }
         spin_unlock(&inode->i_lock);
-
-        if (nfs_need_commit(NFS_I(inode)))
-                __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
-
         return ret;
 }
+
 #else
 static inline int nfs_need_commit(struct nfs_inode *nfsi)
 {
         return 0;
 }
 
-static inline int nfs_scan_commit(struct inode *inode, struct list_head *dst, pgoff_t idx_start, unsigned int npages)
+static inline int nfs_scan_commit(struct inode *inode, struct list_head *dst)
 {
         return 0;
 }
@@ -579,6 +601,7 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
         unsigned int rqend;
         unsigned int end;
         int error;
+        struct pnfs_layout_segment *lseg = NULL;
 
         if (!PagePrivate(page))
                 return NULL;
@@ -614,12 +637,7 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
                 spin_lock(&inode->i_lock);
         }
 
-        if (nfs_clear_request_commit(req) &&
-            radix_tree_tag_clear(&NFS_I(inode)->nfs_page_tree,
-                                 req->wb_index, NFS_PAGE_TAG_COMMIT) != NULL) {
-                NFS_I(inode)->ncommit--;
-                pnfs_clear_request_commit(req);
-        }
+        lseg = nfs_clear_request_commit(req);
 
         /* Okay, the request matches. Update the region */
         if (offset < req->wb_offset) {
@@ -632,6 +650,7 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
                 req->wb_bytes = rqend - req->wb_offset;
 out_unlock:
         spin_unlock(&inode->i_lock);
+        put_lseg(lseg);
         return req;
 out_flushme:
         spin_unlock(&inode->i_lock);
@@ -653,7 +672,6 @@ static struct nfs_page * nfs_setup_write_request(struct nfs_open_context* ctx,
 {
         struct inode *inode = page->mapping->host;
         struct nfs_page *req;
-        int error;
 
         req = nfs_try_to_update_request(inode, page, offset, bytes);
         if (req != NULL)
@@ -661,11 +679,7 @@ static struct nfs_page * nfs_setup_write_request(struct nfs_open_context* ctx,
         req = nfs_create_request(ctx, inode, page, offset, bytes);
         if (IS_ERR(req))
                 goto out;
-        error = nfs_inode_add_request(inode, req);
-        if (error != 0) {
-                nfs_release_request(req);
-                req = ERR_PTR(error);
-        }
+        nfs_inode_add_request(inode, req);
 out:
         return req;
 }
@@ -1458,7 +1472,7 @@ void nfs_commit_release_pages(struct nfs_write_data *data)
         while (!list_empty(&data->pages)) {
                 req = nfs_list_entry(data->pages.next);
                 nfs_list_remove_request(req);
-                nfs_clear_request_commit(req);
+                nfs_clear_page_commit(req->wb_page);
 
                 dprintk("NFS:       commit (%s/%lld %d@%lld)",
                         req->wb_context->dentry->d_sb->s_id,
@@ -1515,7 +1529,7 @@ int nfs_commit_inode(struct inode *inode, int how)
         res = nfs_commit_set_lock(NFS_I(inode), may_wait);
         if (res <= 0)
                 goto out_mark_dirty;
-        res = nfs_scan_commit(inode, &head, 0, 0);
+        res = nfs_scan_commit(inode, &head);
         if (res) {
                 int error;