nfs: implement i_op->atomic_open()

Replace NFS4 specific ->lookup implementation with ->atomic_open impelementation
and use the generic nfs_lookup for other lookups.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index f430057..0d8c712 100644 (file)
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -111,11 +111,15 @@ const struct inode_operations nfs3_dir_inode_operations = {
 
 #ifdef CONFIG_NFS_V4
 
-static struct dentry *nfs_atomic_lookup(struct inode *, struct dentry *, struct nameidata *);
-static int nfs_open_create(struct inode *dir, struct dentry *dentry, umode_t mode, struct nameidata *nd);
+static struct file *nfs_atomic_open(struct inode *, struct dentry *,
+                                   struct opendata *, unsigned, umode_t,
+                                   bool *);
+static int nfs4_create(struct inode *dir, struct dentry *dentry,
+                      umode_t mode, struct nameidata *nd);
 const struct inode_operations nfs4_dir_inode_operations = {
-       .create         = nfs_open_create,
-       .lookup         = nfs_atomic_lookup,
+       .create         = nfs4_create,
+       .lookup         = nfs_lookup,
+       .atomic_open    = nfs_atomic_open,
        .link           = nfs_link,
        .unlink         = nfs_unlink,
        .symlink        = nfs_symlink,
@@ -1403,120 +1407,132 @@ static int do_open(struct inode *inode, struct file *filp)
        return 0;
 }
 
-static int nfs_intent_set_file(struct nameidata *nd, struct nfs_open_context *ctx)
+static struct file *nfs_finish_open(struct nfs_open_context *ctx,
+                                   struct dentry *dentry,
+                                   struct opendata *od, unsigned open_flags)
 {
        struct file *filp;
-       int ret = 0;
+       int err;
+
+       if (ctx->dentry != dentry) {
+               dput(ctx->dentry);
+               ctx->dentry = dget(dentry);
+       }
 
        /* If the open_intent is for execute, we have an extra check to make */
        if (ctx->mode & FMODE_EXEC) {
-               ret = nfs_may_open(ctx->dentry->d_inode,
-                               ctx->cred,
-                               nd->intent.open.flags);
-               if (ret < 0)
+               err = nfs_may_open(dentry->d_inode, ctx->cred, open_flags);
+               if (err < 0) {
+                       filp = ERR_PTR(err);
                        goto out;
+               }
        }
-       filp = lookup_instantiate_filp(nd, ctx->dentry, do_open);
-       if (IS_ERR(filp))
-               ret = PTR_ERR(filp);
-       else
+
+       filp = finish_open(od, dentry, do_open);
+       if (!IS_ERR(filp))
                nfs_file_set_open_context(filp, ctx);
+
 out:
        put_nfs_open_context(ctx);
-       return ret;
+       return filp;
 }
 
-static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
+static struct file *nfs_atomic_open(struct inode *dir, struct dentry *dentry,
+                                   struct opendata *od, unsigned open_flags,
+                                   umode_t mode, bool *created)
 {
        struct nfs_open_context *ctx;
-       struct iattr attr;
-       struct dentry *res = NULL;
+       struct dentry *res;
+       struct iattr attr = { .ia_valid = ATTR_OPEN };
        struct inode *inode;
-       int open_flags;
+       struct file *filp;
        int err;
 
-       dfprintk(VFS, "NFS: atomic_lookup(%s/%ld), %s\n",
+       /* Expect a negative dentry */
+       BUG_ON(dentry->d_inode);
+
+       dfprintk(VFS, "NFS: atomic_open(%s/%ld), %s\n",
                        dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
 
-       /* Check that we are indeed trying to open this file */
-       if (!is_atomic_open(nd))
+       /* NFS only supports OPEN on regular files */
+       if ((open_flags & O_DIRECTORY)) {
+               err = -ENOENT;
+               if (!d_unhashed(dentry)) {
+                       /*
+                        * Hashed negative dentry with O_DIRECTORY: dentry was
+                        * revalidated and is fine, no need to perform lookup
+                        * again
+                        */
+                       goto out_err;
+               }
                goto no_open;
-
-       if (dentry->d_name.len > NFS_SERVER(dir)->namelen) {
-               res = ERR_PTR(-ENAMETOOLONG);
-               goto out;
        }
 
-       /* Let vfs_create() deal with O_EXCL. Instantiate, but don't hash
-        * the dentry. */
-       if (nd->flags & LOOKUP_EXCL) {
-               d_instantiate(dentry, NULL);
-               goto out;
-       }
-
-       open_flags = nd->intent.open.flags;
-       attr.ia_valid = ATTR_OPEN;
-
-       ctx = create_nfs_open_context(dentry, open_flags);
-       res = ERR_CAST(ctx);
-       if (IS_ERR(ctx))
-               goto out;
+       err = -ENAMETOOLONG;
+       if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
+               goto out_err;
 
-       if (nd->flags & LOOKUP_CREATE) {
-               attr.ia_mode = nd->intent.open.create_mode;
+       if (open_flags & O_CREAT) {
                attr.ia_valid |= ATTR_MODE;
-               attr.ia_mode &= ~current_umask();
-       } else
-               open_flags &= ~(O_EXCL | O_CREAT);
-
+               attr.ia_mode = mode & ~current_umask();
+       }
        if (open_flags & O_TRUNC) {
                attr.ia_valid |= ATTR_SIZE;
                attr.ia_size = 0;
        }
 
-       /* Open the file on the server */
+       ctx = create_nfs_open_context(dentry, open_flags);
+       err = PTR_ERR(ctx);
+       if (IS_ERR(ctx))
+               goto out_err;
+
        nfs_block_sillyrename(dentry->d_parent);
        inode = NFS_PROTO(dir)->open_context(dir, ctx, open_flags, &attr);
+       d_drop(dentry);
        if (IS_ERR(inode)) {
                nfs_unblock_sillyrename(dentry->d_parent);
                put_nfs_open_context(ctx);
-               switch (PTR_ERR(inode)) {
-                       /* Make a negative dentry */
-                       case -ENOENT:
-                               d_add(dentry, NULL);
-                               res = NULL;
-                               goto out;
-                       /* This turned out not to be a regular file */
-                       case -EISDIR:
-                       case -ENOTDIR:
+               err = PTR_ERR(inode);
+               switch (err) {
+               case -ENOENT:
+                       d_add(dentry, NULL);
+                       break;
+               case -EISDIR:
+               case -ENOTDIR:
+                       goto no_open;
+               case -ELOOP:
+                       if (!(open_flags & O_NOFOLLOW))
                                goto no_open;
-                       case -ELOOP:
-                               if (!(nd->intent.open.flags & O_NOFOLLOW))
-                                       goto no_open;
+                       break;
                        /* case -EINVAL: */
-                       default:
-                               res = ERR_CAST(inode);
-                               goto out;
+               default:
+                       break;
                }
+               goto out_err;
        }
        res = d_add_unique(dentry, inode);
-       nfs_unblock_sillyrename(dentry->d_parent);
-       if (res != NULL) {
-               dput(ctx->dentry);
-               ctx->dentry = dget(res);
+       if (res != NULL)
                dentry = res;
-       }
-       err = nfs_intent_set_file(nd, ctx);
-       if (err < 0) {
-               if (res != NULL)
-                       dput(res);
-               return ERR_PTR(err);
-       }
-out:
+
+       nfs_unblock_sillyrename(dentry->d_parent);
        nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
-       return res;
+
+       filp = nfs_finish_open(ctx, dentry, od, open_flags);
+
+       dput(res);
+       return filp;
+
+out_err:
+       return ERR_PTR(err);
+
 no_open:
-       return nfs_lookup(dir, dentry, nd);
+       res = nfs_lookup(dir, dentry, NULL);
+       err = PTR_ERR(res);
+       if (IS_ERR(res))
+               goto out_err;
+
+       finish_no_open(od, res);
+       return NULL;
 }
 
 static int nfs4_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
@@ -1566,8 +1582,8 @@ no_open:
        return nfs_lookup_revalidate(dentry, nd);
 }
 
-static int nfs_open_create(struct inode *dir, struct dentry *dentry,
-               umode_t mode, struct nameidata *nd)
+static int nfs4_create(struct inode *dir, struct dentry *dentry,
+                      umode_t mode, struct nameidata *nd)
 {
        struct nfs_open_context *ctx = NULL;
        struct iattr attr;
@@ -1591,19 +1607,14 @@ static int nfs_open_create(struct inode *dir, struct dentry *dentry,
        error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, ctx);
        if (error != 0)
                goto out_put_ctx;
-       if (nd) {
-               error = nfs_intent_set_file(nd, ctx);
-               if (error < 0)
-                       goto out_err;
-       } else {
-               put_nfs_open_context(ctx);
-       }
+
+       put_nfs_open_context(ctx);
+
        return 0;
 out_put_ctx:
        put_nfs_open_context(ctx);
 out_err_drop:
        d_drop(dentry);
-out_err:
        return error;
 }