NFS: Be more aggressive in using readdirplus for 'ls -l' situations

Try to detect 'ls -l' by having nfs_getattr() look at whether or not
there is an opendir() file descriptor for the parent directory.
If so, then assume that we want to force use of readdirplus in order
to avoid the multiple GETATTR calls over the wire.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index be38b573495a78ddf281629da6e5f85f98eed17b..c8e48c26418bb2a7ed1185b4b6c38de139171736 100644 (file)
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -69,21 +69,28 @@ const struct address_space_operations nfs_dir_aops = {
 
 static struct nfs_open_dir_context *alloc_nfs_open_dir_context(struct inode *dir, struct rpc_cred *cred)
 {
+       struct nfs_inode *nfsi = NFS_I(dir);
        struct nfs_open_dir_context *ctx;
        ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
        if (ctx != NULL) {
                ctx->duped = 0;
-               ctx->attr_gencount = NFS_I(dir)->attr_gencount;
+               ctx->attr_gencount = nfsi->attr_gencount;
                ctx->dir_cookie = 0;
                ctx->dup_cookie = 0;
                ctx->cred = get_rpccred(cred);
+               spin_lock(&dir->i_lock);
+               list_add(&ctx->list, &nfsi->open_files);
+               spin_unlock(&dir->i_lock);
                return ctx;
        }
        return  ERR_PTR(-ENOMEM);
 }
 
-static void put_nfs_open_dir_context(struct nfs_open_dir_context *ctx)
+static void put_nfs_open_dir_context(struct inode *dir, struct nfs_open_dir_context *ctx)
 {
+       spin_lock(&dir->i_lock);
+       list_del(&ctx->list);
+       spin_unlock(&dir->i_lock);
        put_rpccred(ctx->cred);
        kfree(ctx);
 }
@@ -126,7 +133,7 @@ out:
 static int
 nfs_closedir(struct inode *inode, struct file *filp)
 {
-       put_nfs_open_dir_context(filp->private_data);
+       put_nfs_open_dir_context(filp->f_path.dentry->d_inode, filp->private_data);
        return 0;
 }
 
@@ -437,6 +444,22 @@ void nfs_advise_use_readdirplus(struct inode *dir)
        set_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(dir)->flags);
 }
 
+/*
+ * This function is mainly for use by nfs_getattr().
+ *
+ * If this is an 'ls -l', we want to force use of readdirplus.
+ * Do this by checking if there is an active file descriptor
+ * and calling nfs_advise_use_readdirplus, then forcing a
+ * cache flush.
+ */
+void nfs_force_use_readdirplus(struct inode *dir)
+{
+       if (!list_empty(&NFS_I(dir)->open_files)) {
+               nfs_advise_use_readdirplus(dir);
+               nfs_zap_mapping(dir, dir->i_mapping);
+       }
+}
+
 static
 void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry)
 {
@@ -815,6 +838,17 @@ int uncached_readdir(nfs_readdir_descriptor_t *desc)
        goto out;
 }
 
+static bool nfs_dir_mapping_need_revalidate(struct inode *dir)
+{
+       struct nfs_inode *nfsi = NFS_I(dir);
+
+       if (nfs_attribute_cache_expired(dir))
+               return true;
+       if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
+               return true;
+       return false;
+}
+
 /* The file offset position represents the dirent entry number.  A
    last cookie cache takes care of the common case of reading the
    whole directory.
@@ -847,7 +881,7 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx)
        desc->plus = nfs_use_readdirplus(inode, ctx) ? 1 : 0;
 
        nfs_block_sillyrename(dentry);
-       if (ctx->pos == 0 || nfs_attribute_cache_expired(inode))
+       if (ctx->pos == 0 || nfs_dir_mapping_need_revalidate(inode))
                res = nfs_revalidate_mapping(inode, file->f_mapping);
        if (res < 0)
                goto out;

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 360114ae8b829bf705eaf4feda49b8fe484de2c0..9dbef878a2b207e89bf77a366c7ce55702094b1a 100644 (file)
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -588,6 +588,25 @@ void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr)
 }
 EXPORT_SYMBOL_GPL(nfs_setattr_update_inode);
 
+static void nfs_request_parent_use_readdirplus(struct dentry *dentry)
+{
+       struct dentry *parent;
+
+       parent = dget_parent(dentry);
+       nfs_force_use_readdirplus(parent->d_inode);
+       dput(parent);
+}
+
+static bool nfs_need_revalidate_inode(struct inode *inode)
+{
+       if (NFS_I(inode)->cache_validity &
+                       (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_LABEL))
+               return true;
+       if (nfs_attribute_cache_expired(inode))
+               return true;
+       return false;
+}
+
 int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
 {
        struct inode *inode = dentry->d_inode;
@@ -616,10 +635,13 @@ int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
            ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
                need_atime = 0;
 
-       if (need_atime)
-               err = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
-       else
-               err = nfs_revalidate_inode(NFS_SERVER(inode), inode);
+       if (need_atime || nfs_need_revalidate_inode(inode)) {
+               struct nfs_server *server = NFS_SERVER(inode);
+
+               if (server->caps & NFS_CAP_READDIRPLUS)
+                       nfs_request_parent_use_readdirplus(dentry);
+               err = __nfs_revalidate_inode(server, inode);
+       }
        if (!err) {
                generic_fillattr(inode, stat);
                stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
@@ -961,9 +983,7 @@ int nfs_attribute_cache_expired(struct inode *inode)
  */
 int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
 {
-       if (!(NFS_I(inode)->cache_validity &
-                       (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_LABEL))
-                       && !nfs_attribute_cache_expired(inode))
+       if (!nfs_need_revalidate_inode(inode))
                return NFS_STALE(inode) ? -ESTALE : 0;
        return __nfs_revalidate_inode(server, inode);
 }

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index fafdddac8271e4d9e90ea254465fb8b2f7672cbe..7f7c476d0c2c3bca746782e5b4e669ace23ea3a9 100644 (file)
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -300,6 +300,7 @@ extern struct nfs_client *nfs_init_client(struct nfs_client *clp,
                           const char *ip_addr);
 
 /* dir.c */
+extern void nfs_force_use_readdirplus(struct inode *dir);
 extern unsigned long nfs_access_cache_count(struct shrinker *shrink,
                                            struct shrink_control *sc);
 extern unsigned long nfs_access_cache_scan(struct shrinker *shrink,

diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 0ae5807480f466af6fc9de106b29207bc03f9752..f55a90bed0b409923288fc90ca2dbcd2b2d44865 100644 (file)
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -92,6 +92,7 @@ struct nfs_open_context {
 };
 
 struct nfs_open_dir_context {
+       struct list_head list;
        struct rpc_cred *cred;
        unsigned long attr_gencount;
        __u64 dir_cookie;