[PATCH 01/12] fd: add a new __anon_inode_getfd helper

Christoph Hellwig
2020-05-08T15:36:43Z

Add a helper that is equivalent to anon_inode_getfd minus the final
fd_install.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/anon_inodes.c | 41 ++++++++++++++++++++++---------------
include/linux/anon_inodes.h | 2 ++
2 files changed, 26 insertions(+), 17 deletions(-)

diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c
index 89714308c25b8..1b2acd2bbaa32 100644
--- a/fs/anon_inodes.c
+++ b/fs/anon_inodes.c
@@ -106,6 +106,26 @@ struct file *anon_inode_getfile(const char *name,
}
EXPORT_SYMBOL_GPL(anon_inode_getfile);

+int __anon_inode_getfd(const char *name, const struct file_operations *fops,
+ void *priv, int flags, struct file **file)
+{
+ int fd;
+
+ fd = get_unused_fd_flags(flags);
+ if (fd < 0)
+ return fd;
+
+ *file = anon_inode_getfile(name, fops, priv, flags);
+ if (IS_ERR(*file))
+ goto err_put_unused_fd;
+ return fd;
+
+err_put_unused_fd:
+ put_unused_fd(fd);
+ return PTR_ERR(*file);
+}
+EXPORT_SYMBOL_GPL(__anon_inode_getfd);
+
/**
* anon_inode_getfd - creates a new file instance by hooking it up to an
* anonymous inode, and a dentry that describe the "class"
@@ -125,26 +145,13 @@ EXPORT_SYMBOL_GPL(anon_inode_getfile);
int anon_inode_getfd(const char *name, const struct file_operations *fops,
void *priv, int flags)
{
- int error, fd;
struct file *file;
+ int fd;

- error = get_unused_fd_flags(flags);
- if (error < 0)
- return error;
- fd = error;
-
- file = anon_inode_getfile(name, fops, priv, flags);
- if (IS_ERR(file)) {
- error = PTR_ERR(file);
- goto err_put_unused_fd;
- }
- fd_install(fd, file);
-
+ fd = __anon_inode_getfd(name, fops, priv, flags, &file);
+ if (fd >= 0)
+ fd_install(fd, file);
return fd;
-
-err_put_unused_fd:
- put_unused_fd(fd);
- return error;
}
EXPORT_SYMBOL_GPL(anon_inode_getfd);

diff --git a/include/linux/anon_inodes.h b/include/linux/anon_inodes.h
index d0d7d96261adf..338449d06b617 100644
--- a/include/linux/anon_inodes.h
+++ b/include/linux/anon_inodes.h
@@ -16,6 +16,8 @@ struct file *anon_inode_getfile(const char *name,
void *priv, int flags);
int anon_inode_getfd(const char *name, const struct file_operations *fops,
void *priv, int flags);
+int __anon_inode_getfd(const char *name, const struct file_operations *fops,
+ void *priv, int flags, struct file **file);

#endif /* _LINUX_ANON_INODES_H */

--
2.26.2