[PATCH] v9fs: fix atomic create open

In order to assure atomic create+open v9fs stores the open fid produced by
v9fs_vfs_create in the dentry, from where v9fs_file_open retrieves it and
associates it with the open file.

This patch modifies v9fs to use nameidata.intent.open values to do the atomic
create+open.

Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 17 insertions, 56 deletions

diff --git a/fs/9p/fid.c b/fs/9p/fid.c
index eda4497..c27f546 100644
--- a/fs/9p/fid.c
+++ b/fs/9p/fid.c
@@ -40,7 +40,7 @@
  *
  */
 
-static int v9fs_fid_insert(struct v9fs_fid *fid, struct dentry *dentry)
+int v9fs_fid_insert(struct v9fs_fid *fid, struct dentry *dentry)
 {
 	struct list_head *fid_list = (struct list_head *)dentry->d_fsdata;
 	dprintk(DEBUG_9P, "fid %d (%p) dentry %s (%p)\n", fid->fid, fid,
@@ -68,14 +68,11 @@ static int v9fs_fid_insert(struct v9fs_fid *fid, struct dentry *dentry)
  *
  */
 
-struct v9fs_fid *v9fs_fid_create(struct dentry *dentry,
-	struct v9fs_session_info *v9ses, int fid, int create)
+struct v9fs_fid *v9fs_fid_create(struct v9fs_session_info *v9ses, int fid)
 {
 	struct v9fs_fid *new;
 
-	dprintk(DEBUG_9P, "fid create dentry %p, fid %d, create %d\n",
-		dentry, fid, create);
-
+	dprintk(DEBUG_9P, "fid create fid %d\n", fid);
 	new = kmalloc(sizeof(struct v9fs_fid), GFP_KERNEL);
 	if (new == NULL) {
 		dprintk(DEBUG_ERROR, "Out of Memory\n");
@@ -85,19 +82,13 @@ struct v9fs_fid *v9fs_fid_create(struct dentry *dentry,
 	new->fid = fid;
 	new->v9ses = v9ses;
 	new->fidopen = 0;
-	new->fidcreate = create;
 	new->fidclunked = 0;
 	new->iounit = 0;
 	new->rdir_pos = 0;
 	new->rdir_fcall = NULL;
+	INIT_LIST_HEAD(&new->list);
 
-	if (v9fs_fid_insert(new, dentry) == 0)
 		return new;
-	else {
-		dprintk(DEBUG_ERROR, "Problems inserting to dentry\n");
-		kfree(new);
-		return NULL;
-	}
 }
 
 /**
@@ -119,7 +110,7 @@ void v9fs_fid_destroy(struct v9fs_fid *fid)
 static struct v9fs_fid *v9fs_fid_walk_up(struct dentry *dentry)
 {
 	int fidnum, cfidnum, err;
-	struct v9fs_fid *cfid;
+	struct v9fs_fid *cfid, *fid;
 	struct dentry *cde;
 	struct v9fs_session_info *v9ses;
 
@@ -158,7 +149,16 @@ static struct v9fs_fid *v9fs_fid_walk_up(struct dentry *dentry)
 		cde = cde->d_parent;
 	}
 
-	return v9fs_fid_create(dentry, v9ses, fidnum, 0);
+	fid = v9fs_fid_create(v9ses, fidnum);
+	if (fid) {
+		err = v9fs_fid_insert(fid, dentry);
+		if (err < 0) {
+			kfree(fid);
+			goto clunk_fid;
+		}
+	}
+
+	return fid;
 
 clunk_fid:
 	v9fs_t_clunk(v9ses, fidnum);
@@ -179,29 +179,12 @@ clunk_fid:
 struct v9fs_fid *v9fs_fid_lookup(struct dentry *dentry)
 {
 	struct list_head *fid_list = (struct list_head *)dentry->d_fsdata;
-	struct v9fs_fid *current_fid = NULL;
-	struct v9fs_fid *temp = NULL;
 	struct v9fs_fid *return_fid = NULL;
 
 	dprintk(DEBUG_9P, " dentry: %s (%p)\n", dentry->d_iname, dentry);
 
-	if (fid_list) {
-		list_for_each_entry_safe(current_fid, temp, fid_list, list) {
-			if (!current_fid->fidcreate) {
-				return_fid = current_fid;
-				break;
-			}
-		}
-
-		if (!return_fid)
-			return_fid = current_fid;
-	}
-
-	/* we are at the root but didn't match */
-	if ((!return_fid) && (dentry->d_parent == dentry)) {
-		/* TODO: clone attach with new uid */
-		return_fid = current_fid;
-	}
+	if (fid_list)
+		return_fid = list_entry(fid_list->next, struct v9fs_fid, list);
 
 	if (!return_fid) {
 		struct dentry *par = current->fs->pwd->d_parent;
@@ -228,25 +211,3 @@ struct v9fs_fid *v9fs_fid_lookup(struct dentry *dentry)
 
 	return return_fid;
 }
-
-struct v9fs_fid *v9fs_fid_get_created(struct dentry *dentry)
-{
-	struct list_head *fid_list;
-	struct v9fs_fid *fid, *ftmp, *ret;
-
-	dprintk(DEBUG_9P, " dentry: %s (%p)\n", dentry->d_iname, dentry);
-	fid_list = (struct list_head *)dentry->d_fsdata;
-	ret = NULL;
-	if (fid_list) {
-		list_for_each_entry_safe(fid, ftmp, fid_list, list) {
-			if (fid->fidcreate && fid->pid == current->pid) {
-				list_del(&fid->list);
-				ret = fid;
-				break;
-			}
-		}
-	}
-
-	dprintk(DEBUG_9P, "return %p\n", ret);
-	return ret;
-}