fs: split off vfs_getdents function of getdents64 syscall

This splits off the vfs_getdents function from the getdents64 system
call. This allows io_uring to call the vfs_getdents function.

Signed-off-by: Stefan Roesch <shr@fb.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20211221164004.119663-3-shr@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/internal.h b/fs/internal.h
index 7979ff8d168cc205d318b4681549cb49f2307cbe..432ea3ce76ec4abd08a97855aa11e6ed95d3c4b3 100644 (file)
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -194,3 +194,11 @@ long splice_file_to_pipe(struct file *in,
                         struct pipe_inode_info *opipe,
                         loff_t *offset,
                         size_t len, unsigned int flags);
+
+/*
+ * fs/readdir.c
+ */
+struct linux_dirent64;
+
+int vfs_getdents(struct file *file, struct linux_dirent64 __user *dirent,
+                unsigned int count, loff_t *pos);

diff --git a/fs/readdir.c b/fs/readdir.c
index c1e6612e0f475b1f429bd5acdca9145f291d2c10..1b1fade875253f2b5385a6b67cff135409febff5 100644 (file)
--- a/fs/readdir.c
+++ b/fs/readdir.c
@@ -21,6 +21,7 @@
 #include <linux/unistd.h>
 #include <linux/compat.h>
 #include <linux/uaccess.h>
+#include "internal.h"
 
 #include <asm/unaligned.h>
 
@@ -359,22 +360,25 @@ efault:
        return -EFAULT;
 }
 
-SYSCALL_DEFINE3(getdents64, unsigned int, fd,
-               struct linux_dirent64 __user *, dirent, unsigned int, count)
+/**
+ * vfs_getdents - getdents without fdget
+ * @file    : pointer to file struct of directory
+ * @dirent  : pointer to user directory structure
+ * @count   : size of buffer
+ * @pos     : file pos
+ */
+int vfs_getdents(struct file *file, struct linux_dirent64 __user *dirent,
+                unsigned int count, loff_t *pos)
 {
-       struct fd f;
        struct getdents_callback64 buf = {
                .ctx.actor = filldir64,
+               .ctx.pos = *pos,
                .count = count,
                .current_dir = dirent
        };
        int error;
 
-       f = fdget_pos(fd);
-       if (!f.file)
-               return -EBADF;
-
-       error = iterate_dir(f.file, &buf.ctx, &f.file->f_pos);
+       error = iterate_dir(file, &buf.ctx, pos);
        if (error >= 0)
                error = buf.error;
        if (buf.prev_reclen) {
@@ -391,6 +395,22 @@ SYSCALL_DEFINE3(getdents64, unsigned int, fd,
        return error;
 }
 
+SYSCALL_DEFINE3(getdents64, unsigned int, fd,
+               struct linux_dirent64 __user *, dirent, unsigned int, count)
+{
+       struct fd f;
+       int error;
+
+       f = fdget_pos(fd);
+       if (!f.file)
+               return -EBADF;
+
+       error = vfs_getdents(f.file, dirent, count, &f.file->f_pos);
+
+       fdput_pos(f);
+       return error;
+ }
+
 #ifdef CONFIG_COMPAT
 struct compat_old_linux_dirent {
        compat_ulong_t  d_ino;