[PATCH v3 09/28] convert vmsplice() to CLASS(fd)

Al Viro
2024-11-02T05:08:29Z

Irregularity here is fdput() not in the same scope as fdget(); we could
just lift it out vmsplice_type() in vmsplice(2), but there's no much
point keeping vmsplice_type() separate after that...

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/splice.c | 33 ++++++++++-----------------------
1 file changed, 10 insertions(+), 23 deletions(-)

diff --git a/fs/splice.c b/fs/splice.c
index 06232d7e505f..29cd39d7f4a0 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -1564,21 +1564,6 @@ static ssize_t vmsplice_to_pipe(struct file *file, struct iov_iter *iter,
return ret;
}

-static int vmsplice_type(struct fd f, int *type)
-{
- if (!fd_file(f))
- return -EBADF;
- if (fd_file(f)->f_mode & FMODE_WRITE) {
- *type = ITER_SOURCE;
- } else if (fd_file(f)->f_mode & FMODE_READ) {
- *type = ITER_DEST;
- } else {
- fdput(f);
- return -EBADF;
- }
- return 0;
-}
-
/*
* Note that vmsplice only really supports true splicing _from_ user memory
* to a pipe, not the other way around. Splicing from user memory is a simple
@@ -1602,21 +1587,25 @@ SYSCALL_DEFINE4(vmsplice, int, fd, const struct iovec __user *, uiov,
struct iovec *iov = iovstack;
struct iov_iter iter;
ssize_t error;
- struct fd f;
int type;

if (unlikely(flags & ~SPLICE_F_ALL))
return -EINVAL;

- f = fdget(fd);
- error = vmsplice_type(f, &type);
- if (error)
- return error;
+ CLASS(fd, f)(fd);
+ if (fd_empty(f))
+ return -EBADF;
+ if (fd_file(f)->f_mode & FMODE_WRITE)
+ type = ITER_SOURCE;
+ else if (fd_file(f)->f_mode & FMODE_READ)
+ type = ITER_DEST;
+ else
+ return -EBADF;

error = import_iovec(type, uiov, nr_segs,
ARRAY_SIZE(iovstack), &iov, &iter);
if (error < 0)
- goto out_fdput;
+ return error;

if (!iov_iter_count(&iter))
error = 0;
@@ -1626,8 +1615,6 @@ SYSCALL_DEFINE4(vmsplice, int, fd, const struct iovec __user *, uiov,
error = vmsplice_to_user(fd_file(f), &iter, flags);

kfree(iov);
-out_fdput:
- fdput(f);
return error;
}

--
2.39.5