[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 eda449778fa5..c27f546dd25b 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;
-}