NFS: Throttle page dirtying while we're flushing to disk

[pandora-kernel.git] / fs / nfs / write.c

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 9f98458..36fd35e 100644 (file)
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -313,19 +313,34 @@ static int nfs_writepages_callback(struct page *page, struct writeback_control *
 int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
 {
        struct inode *inode = mapping->host;
+       unsigned long *bitlock = &NFS_I(inode)->flags;
        struct nfs_pageio_descriptor pgio;
        int err;
 
+       /* Stop dirtying of new pages while we sync */
+       err = wait_on_bit_lock(bitlock, NFS_INO_FLUSHING,
+                       nfs_wait_bit_killable, TASK_KILLABLE);
+       if (err)
+               goto out_err;
+
        nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES);
 
        nfs_pageio_init_write(&pgio, inode, wb_priority(wbc));
        err = write_cache_pages(mapping, wbc, nfs_writepages_callback, &pgio);
        nfs_pageio_complete(&pgio);
+
+       clear_bit_unlock(NFS_INO_FLUSHING, bitlock);
+       smp_mb__after_clear_bit();
+       wake_up_bit(bitlock, NFS_INO_FLUSHING);
+
        if (err < 0)
-               return err;
-       if (pgio.pg_error < 0)
-               return pgio.pg_error;
+               goto out_err;
+       err = pgio.pg_error;
+       if (err < 0)
+               goto out_err;
        return 0;
+out_err:
+       return err;
 }
 
 /*
@@ -404,7 +419,6 @@ nfs_mark_request_commit(struct nfs_page *req)
        struct nfs_inode *nfsi = NFS_I(inode);
 
        spin_lock(&inode->i_lock);
-       nfsi->ncommit++;
        set_bit(PG_CLEAN, &(req)->wb_flags);
        radix_tree_tag_set(&nfsi->nfs_page_tree,
                        req->wb_index,
@@ -523,6 +537,12 @@ static void nfs_cancel_commit_list(struct list_head *head)
        }
 }
 
+static int
+nfs_need_commit(struct nfs_inode *nfsi)
+{
+       return radix_tree_tagged(&nfsi->nfs_page_tree, NFS_PAGE_TAG_COMMIT);
+}
+
 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
 /*
  * nfs_scan_commit - Scan an inode for commit requests
@@ -538,16 +558,18 @@ static int
 nfs_scan_commit(struct inode *inode, struct list_head *dst, pgoff_t idx_start, unsigned int npages)
 {
        struct nfs_inode *nfsi = NFS_I(inode);
-       int res = 0;
 
-       if (nfsi->ncommit != 0) {
-               res = nfs_scan_list(nfsi, dst, idx_start, npages,
-                               NFS_PAGE_TAG_COMMIT);
-               nfsi->ncommit -= res;
-       }
-       return res;
+       if (!nfs_need_commit(nfsi))
+               return 0;
+
+       return nfs_scan_list(nfsi, dst, idx_start, npages, NFS_PAGE_TAG_COMMIT);
 }
 #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)
 {
        return 0;
@@ -820,7 +842,7 @@ static int nfs_write_rpcsetup(struct nfs_page *req,
        data->args.stable  = NFS_UNSTABLE;
        if (how & FLUSH_STABLE) {
                data->args.stable = NFS_DATA_SYNC;
-               if (!NFS_I(inode)->ncommit)
+               if (!nfs_need_commit(NFS_I(inode)))
                        data->args.stable = NFS_FILE_SYNC;
        }
 
@@ -1425,18 +1447,13 @@ static int nfs_write_mapping(struct address_space *mapping, int how)
 {
        struct writeback_control wbc = {
                .bdi = mapping->backing_dev_info,
-               .sync_mode = WB_SYNC_NONE,
+               .sync_mode = WB_SYNC_ALL,
                .nr_to_write = LONG_MAX,
                .range_start = 0,
                .range_end = LLONG_MAX,
                .for_writepages = 1,
        };
-       int ret;
 
-       ret = __nfs_write_mapping(mapping, &wbc, how);
-       if (ret < 0)
-               return ret;
-       wbc.sync_mode = WB_SYNC_ALL;
        return __nfs_write_mapping(mapping, &wbc, how);
 }