VFS: rename do_splice_to/from to vfs_splice_* and export symbols

A stackable file system which uses vm_ops->fault, and does not implement
address_space_operations, cannot use generic_file_splice_read/write, but has
to implement ->splice_read/write itself.  These two helper functions are
very useful to such a module.

Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>

diff --git a/fs/splice.c b/fs/splice.c
index dbbe267211b19751423f8a212d8ff51165f2ecc5..11199639b5af3707de7127e0f5d0b226ea2924cc 100644 (file)
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -917,8 +917,8 @@ EXPORT_SYMBOL(generic_splice_sendpage);
 /*
  * Attempt to initiate a splice from pipe to file.
  */
-static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
-                          loff_t *ppos, size_t len, unsigned int flags)
+long vfs_splice_from(struct pipe_inode_info *pipe, struct file *out,
+                    loff_t *ppos, size_t len, unsigned int flags)
 {
        int ret;
 
@@ -934,13 +934,14 @@ static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
 
        return out->f_op->splice_write(pipe, out, ppos, len, flags);
 }
+EXPORT_SYMBOL_GPL(vfs_splice_from);
 
 /*
  * Attempt to initiate a splice from a file to a pipe.
  */
-static long do_splice_to(struct file *in, loff_t *ppos,
-                        struct pipe_inode_info *pipe, size_t len,
-                        unsigned int flags)
+long vfs_splice_to(struct file *in, loff_t *ppos,
+                  struct pipe_inode_info *pipe, size_t len,
+                  unsigned int flags)
 {
        int ret;
 
@@ -956,6 +957,7 @@ static long do_splice_to(struct file *in, loff_t *ppos,
 
        return in->f_op->splice_read(in, ppos, pipe, len, flags);
 }
+EXPORT_SYMBOL_GPL(vfs_splice_to);
 
 long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
                      size_t len, unsigned int flags)
@@ -1010,7 +1012,7 @@ long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
                 */
                max_read_len = min(len, (size_t)(PIPE_BUFFERS*PAGE_SIZE));
 
-               ret = do_splice_to(in, ppos, pipe, max_read_len, flags);
+               ret = vfs_splice_to(in, ppos, pipe, max_read_len, flags);
                if (unlikely(ret <= 0))
                        goto out_release;
 
@@ -1021,8 +1023,8 @@ long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
                 * must not do the output in nonblocking mode as then we
                 * could get stuck data in the internal pipe:
                 */
-               ret = do_splice_from(pipe, out, &out_off, read_len,
-                                    flags & ~SPLICE_F_NONBLOCK);
+               ret = vfs_splice_from(pipe, out, &out_off, read_len,
+                                     flags & ~SPLICE_F_NONBLOCK);
                if (unlikely(ret <= 0))
                        goto out_release;
 
@@ -1106,7 +1108,7 @@ static long do_splice(struct file *in, loff_t __user *off_in,
                } else
                        off = &out->f_pos;
 
-               ret = do_splice_from(pipe, out, off, len, flags);
+               ret = vfs_splice_from(pipe, out, off, len, flags);
 
                if (off_out && copy_to_user(off_out, off, sizeof(loff_t)))
                        ret = -EFAULT;
@@ -1127,7 +1129,7 @@ static long do_splice(struct file *in, loff_t __user *off_in,
                } else
                        off = &in->f_pos;
 
-               ret = do_splice_to(in, off, pipe, len, flags);
+               ret = vfs_splice_to(in, off, pipe, len, flags);
 
                if (off_in && copy_to_user(off_in, off, sizeof(loff_t)))
                        ret = -EFAULT;

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 6a41f4cab14c9a6efa90c824006497a55a230a19..8f59a4642e673d5c2eba66139e9c38e89317cbef 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1780,6 +1780,11 @@ extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe,
                struct file *out, loff_t *, size_t len, unsigned int flags);
 extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
                size_t len, unsigned int flags);
+extern long vfs_splice_from(struct pipe_inode_info *pipe, struct file *out,
+                           loff_t *ppos, size_t len, unsigned int flags);
+extern long vfs_splice_to(struct file *in, loff_t *ppos,
+                         struct pipe_inode_info *pipe, size_t len,
+                         unsigned int flags);
 
 extern void
 file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping);