[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, 40 insertions, 66 deletions

diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index c7e14d917215..de3a129698da 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -53,94 +53,70 @@
 int v9fs_file_open(struct inode *inode, struct file *file)
 {
         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
-        struct v9fs_fid *v9fid, *fid;
+        struct v9fs_fid *vfid;
         struct v9fs_fcall *fcall = NULL;
-        int open_mode = 0;
-        unsigned int iounit = 0;
-        int newfid = -1;
-        long result = -1;
+        int omode;
+        int fid = V9FS_NOFID;
+        int err;
 
         dprintk(DEBUG_VFS, "inode: %p file: %p \n", inode, file);
 
-        v9fid = v9fs_fid_get_created(file->f_dentry);
-        if (!v9fid)
-                v9fid = v9fs_fid_lookup(file->f_dentry);
-
-        if (!v9fid) {
+        vfid = v9fs_fid_lookup(file->f_dentry);
+        if (!vfid) {
                 dprintk(DEBUG_ERROR, "Couldn't resolve fid from dentry\n");
                 return -EBADF;
         }
 
-        if (!v9fid->fidcreate) {
-                fid = kmalloc(sizeof(struct v9fs_fid), GFP_KERNEL);
-                if (fid == NULL) {
-                        dprintk(DEBUG_ERROR, "Out of Memory\n");
-                        return -ENOMEM;
-                }
-
-                fid->fidopen = 0;
-                fid->fidcreate = 0;
-                fid->fidclunked = 0;
-                fid->iounit = 0;
-                fid->v9ses = v9ses;
-
-                newfid = v9fs_get_idpool(&v9ses->fidpool);
-                if (newfid < 0) {
+        fid = v9fs_get_idpool(&v9ses->fidpool);
+        if (fid < 0) {
                         eprintk(KERN_WARNING, "newfid fails!\n");
                         return -ENOSPC;
                 }
 
-                result =
-                    v9fs_t_walk(v9ses, v9fid->fid, newfid, NULL, NULL);
-
-                if (result < 0) {
-                        v9fs_put_idpool(newfid, &v9ses->fidpool);
+        err = v9fs_t_walk(v9ses, vfid->fid, fid, NULL, NULL);
+        if (err < 0) {
                         dprintk(DEBUG_ERROR, "rewalk didn't work\n");
-                        return -EBADF;
+                goto put_fid;
+        }
+
+        vfid = kmalloc(sizeof(struct v9fs_fid), GFP_KERNEL);
+        if (vfid == NULL) {
+                dprintk(DEBUG_ERROR, "out of memory\n");
+                goto clunk_fid;
                 }
 
-                fid->fid = newfid;
-                v9fid = fid;
                 /* TODO: do special things for O_EXCL, O_NOFOLLOW, O_SYNC */
                 /* translate open mode appropriately */
-                open_mode = file->f_flags & 0x3;
+        omode = v9fs_uflags2omode(file->f_flags);
+        err = v9fs_t_open(v9ses, fid, omode, &fcall);
+        if (err < 0) {
+                PRINT_FCALL_ERROR("open failed", fcall);
+                goto destroy_vfid;
+        }
 
-                if (file->f_flags & O_EXCL)
-                        open_mode |= V9FS_OEXCL;
+        file->private_data = vfid;
+        vfid->fid = fid;
+        vfid->fidopen = 1;
+        vfid->fidclunked = 0;
+        vfid->iounit = fcall->params.ropen.iounit;
+        vfid->rdir_pos = 0;
+        vfid->rdir_fcall = NULL;
+        vfid->filp = file;
+        kfree(fcall);
 
-                if (v9ses->extended) {
-                        if (file->f_flags & O_TRUNC)
-                                open_mode |= V9FS_OTRUNC;
+        return 0;
 
-                        if (file->f_flags & O_APPEND)
-                                open_mode |= V9FS_OAPPEND;
-                }
+destroy_vfid:
+        v9fs_fid_destroy(vfid);
 
-                result = v9fs_t_open(v9ses, newfid, open_mode, &fcall);
-                if (result < 0) {
-                        PRINT_FCALL_ERROR("open failed", fcall);
-                        kfree(fcall);
-                        return result;
-                }
+clunk_fid:
+        v9fs_t_clunk(v9ses, fid);
 
-                iounit = fcall->params.ropen.iounit;
+put_fid:
+        v9fs_put_idpool(fid, &v9ses->fidpool);
                 kfree(fcall);
-        } else {
-                /* create case */
-                newfid = v9fid->fid;
-                iounit = v9fid->iounit;
-                v9fid->fidcreate = 0;
-        }
-
-        file->private_data = v9fid;
-
-        v9fid->rdir_pos = 0;
-        v9fid->rdir_fcall = NULL;
-        v9fid->fidopen = 1;
-        v9fid->filp = file;
-        v9fid->iounit = iounit;
 
-        return 0;
+        return err;
 }
 
 /**
@@ -289,9 +265,7 @@ v9fs_file_write(struct file *filp, const char __user * data,
                 total += result;
         } while (count);
 
-        if(inode->i_mapping->nrpages)
                 invalidate_inode_pages2(inode->i_mapping);
-
         return total;
 }