[PATCH 02/28] r/o bind mount prepwork: move open_namei()'s vfs_create()

Dave Hansen
2006-08-01T23:53:17Z

The code around vfs_create() in open_namei() is getting a
bit too complex. Right now, there is at least the reference
count on the dentry, and the i_mutex to worry about. Soon,
we'll also have mnt_writecount.

So, break the vfs_create() call out of open_namei(), and
into a helper function. This duplicates the call to
may_open(), but that isn't such a bad thing since the
arguments (acc_mode and flag) were being heavily massaged
anyway.

Later in the series, we'll add the mnt_writecount handling
around this new function call.

Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
---

lxc-dave/fs/namei.c | 30 ++++++++++++++++++++----------
1 files changed, 20 insertions(+), 10 deletions(-)

diff -puN fs/namei.c~B-prepwork-cleanup-open_namei fs/namei.c
--- lxc/fs/namei.c~B-prepwork-cleanup-open_namei 2006-08-01 16:35:13.000000000 -0700
+++ lxc-dave/fs/namei.c 2006-08-01 16:35:14.000000000 -0700
@@ -1587,6 +1587,24 @@ int may_open(struct nameidata *nd, int a
return 0;
}

+static int open_namei_create(struct nameidata *nd, struct path *path,
+ int flag, int mode)
+{
+ int error;
+ struct dentry *dir = nd->dentry;
+
+ if (!IS_POSIXACL(dir->d_inode))
+ mode &= ~current->fs->umask;
+ error = vfs_create(dir->d_inode, path->dentry, mode, nd);
+ mutex_unlock(&dir->d_inode->i_mutex);
+ dput(nd->dentry);
+ nd->dentry = path->dentry;
+ if (error)
+ return error;
+ /* Don't check for write permission, don't truncate */
+ return may_open(nd, 0, flag & ~O_TRUNC);
+}
+
/*
* open_namei()
*
@@ -1668,18 +1686,10 @@ do_last:

/* Negative dentry, just create the file */
if (!path.dentry->d_inode) {
- if (!IS_POSIXACL(dir->d_inode))
- mode &= ~current->fs->umask;
- error = vfs_create(dir->d_inode, path.dentry, mode, nd);
- mutex_unlock(&dir->d_inode->i_mutex);
- dput(nd->dentry);
- nd->dentry = path.dentry;
+ error = open_namei_create(nd, &path, flag, mode);
if (error)
goto exit;
- /* Don't check for write permission, don't truncate */
- acc_mode = 0;
- flag &= ~O_TRUNC;
- goto ok;
+ return 0;
}

/*
_