vfs: create vfs helper vfs_tmpfile()
Factor out some common vfs bits from do_tmpfile()
to be used by overlayfs for concurrent copy up.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
diff --git a/fs/namei.c b/fs/namei.c
index ad74877..7d87699 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3353,13 +3353,50 @@ static int do_last(struct nameidata *nd,
return error;
}
+struct dentry *vfs_tmpfile(struct dentry *dentry, umode_t mode, int open_flag)
+{
+ static const struct qstr name = QSTR_INIT("/", 1);
+ struct dentry *child = NULL;
+ struct inode *dir = dentry->d_inode;
+ struct inode *inode;
+ int error;
+
+ /* we want directory to be writable */
+ error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
+ if (error)
+ goto out_err;
+ error = -EOPNOTSUPP;
+ if (!dir->i_op->tmpfile)
+ goto out_err;
+ error = -ENOMEM;
+ child = d_alloc(dentry, &name);
+ if (unlikely(!child))
+ goto out_err;
+ error = dir->i_op->tmpfile(dir, child, mode);
+ if (error)
+ goto out_err;
+ error = -ENOENT;
+ inode = child->d_inode;
+ if (unlikely(!inode))
+ goto out_err;
+ if (!(open_flag & O_EXCL)) {
+ spin_lock(&inode->i_lock);
+ inode->i_state |= I_LINKABLE;
+ spin_unlock(&inode->i_lock);
+ }
+ return child;
+
+out_err:
+ dput(child);
+ return ERR_PTR(error);
+}
+EXPORT_SYMBOL(vfs_tmpfile);
+
static int do_tmpfile(struct nameidata *nd, unsigned flags,
const struct open_flags *op,
struct file *file, int *opened)
{
- static const struct qstr name = QSTR_INIT("/", 1);
struct dentry *child;
- struct inode *dir;
struct path path;
int error = path_lookupat(nd, flags | LOOKUP_DIRECTORY, &path);
if (unlikely(error))
@@ -3367,25 +3404,12 @@ static int do_tmpfile(struct nameidata *nd, unsigned flags,
error = mnt_want_write(path.mnt);
if (unlikely(error))
goto out;
- dir = path.dentry->d_inode;
- /* we want directory to be writable */
- error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
- if (error)
+ child = vfs_tmpfile(path.dentry, op->mode, op->open_flag);
+ error = PTR_ERR(child);
+ if (unlikely(IS_ERR(child)))
goto out2;
- if (!dir->i_op->tmpfile) {
- error = -EOPNOTSUPP;
- goto out2;
- }
- child = d_alloc(path.dentry, &name);
- if (unlikely(!child)) {
- error = -ENOMEM;
- goto out2;
- }
dput(path.dentry);
path.dentry = child;
- error = dir->i_op->tmpfile(dir, child, op->mode);
- if (error)
- goto out2;
audit_inode(nd->name, child, 0);
/* Don't check for other permissions, the inode was just created */
error = may_open(&path, 0, op->open_flag);
@@ -3396,14 +3420,8 @@ static int do_tmpfile(struct nameidata *nd, unsigned flags,
if (error)
goto out2;
error = open_check_o_direct(file);
- if (error) {
+ if (error)
fput(file);
- } else if (!(op->open_flag & O_EXCL)) {
- struct inode *inode = file_inode(file);
- spin_lock(&inode->i_lock);
- inode->i_state |= I_LINKABLE;
- spin_unlock(&inode->i_lock);
- }
out2:
mnt_drop_write(path.mnt);
out:
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 2ba0743..4a7f3cc9 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1561,6 +1561,9 @@ extern int vfs_unlink(struct inode *, struct dentry *, struct inode **);
extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *, struct inode **, unsigned int);
extern int vfs_whiteout(struct inode *, struct dentry *);
+extern struct dentry *vfs_tmpfile(struct dentry *dentry, umode_t mode,
+ int open_flag);
+
/*
* VFS file helper functions.
*/
