btrfs: use bool argument in free_root_pointers()

[mirror_ubuntu-bionic-kernel.git] / fs / splice.c

diff --git a/fs/splice.c b/fs/splice.c
index 39e2dc01ac12c31a2d4629ddabdda2984319dd49..ffedf6ebb2341553afa74b83575488d2a7bc6d8c 100644 (file)
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -332,8 +332,8 @@ const struct pipe_buf_operations default_pipe_buf_ops = {
        .get = generic_pipe_buf_get,
 };
 
-static int generic_pipe_buf_nosteal(struct pipe_inode_info *pipe,
-                                   struct pipe_buffer *buf)
+int generic_pipe_buf_nosteal(struct pipe_inode_info *pipe,
+                            struct pipe_buffer *buf)
 {
        return 1;
 }
@@ -837,8 +837,8 @@ 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 do_splice_from(struct pipe_inode_info *pipe, struct file *out,
+                   loff_t *ppos, size_t len, unsigned int flags)
 {
        ssize_t (*splice_write)(struct pipe_inode_info *, struct file *,
                                loff_t *, size_t, unsigned int);
@@ -850,13 +850,14 @@ static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
 
        return splice_write(pipe, out, ppos, len, flags);
 }
+EXPORT_SYMBOL_GPL(do_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 do_splice_to(struct file *in, loff_t *ppos,
+                 struct pipe_inode_info *pipe, size_t len,
+                 unsigned int flags)
 {
        ssize_t (*splice_read)(struct file *, loff_t *,
                               struct pipe_inode_info *, size_t, unsigned int);
@@ -879,6 +880,7 @@ static long do_splice_to(struct file *in, loff_t *ppos,
 
        return splice_read(in, ppos, pipe, len, flags);
 }
+EXPORT_SYMBOL_GPL(do_splice_to);
 
 /**
  * splice_direct_to_actor - splices data directly between two non-pipes
@@ -945,11 +947,17 @@ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd,
        sd->flags &= ~SPLICE_F_NONBLOCK;
        more = sd->flags & SPLICE_F_MORE;
 
+       WARN_ON_ONCE(pipe->nrbufs != 0);
+
        while (len) {
+               unsigned int pipe_pages;
                size_t read_len;
                loff_t pos = sd->pos, prev_pos = pos;
 
-               ret = do_splice_to(in, &pos, pipe, len, flags);
+               /* Don't try to read more the pipe has space for. */
+               pipe_pages = pipe->buffers - pipe->nrbufs;
+               read_len = min(len, (size_t)pipe_pages << PAGE_SHIFT);
+               ret = do_splice_to(in, &pos, pipe, read_len, flags);
                if (unlikely(ret <= 0))
                        goto out_release;
 
@@ -1169,8 +1177,15 @@ static long do_splice(struct file *in, loff_t __user *off_in,
 
                pipe_lock(opipe);
                ret = wait_for_space(opipe, flags);
-               if (!ret)
+               if (!ret) {
+                       unsigned int pipe_pages;
+
+                       /* Don't try to read more the pipe has space for. */
+                       pipe_pages = opipe->buffers - opipe->nrbufs;
+                       len = min(len, (size_t)pipe_pages << PAGE_SHIFT);
+
                        ret = do_splice_to(in, &offset, opipe, len, flags);
+               }
                pipe_unlock(opipe);
                if (ret > 0)
                        wakeup_pipe_readers(opipe);
@@ -1571,7 +1586,11 @@ retry:
                         * Get a reference to this pipe buffer,
                         * so we can copy the contents over.
                         */
-                       pipe_buf_get(ipipe, ibuf);
+                       if (!pipe_buf_get(ipipe, ibuf)) {
+                               if (ret == 0)
+                                       ret = -EFAULT;
+                               break;
+                       }
                        *obuf = *ibuf;
 
                        /*
@@ -1580,6 +1599,8 @@ retry:
                         */
                        obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
 
+                       pipe_buf_mark_unmergeable(obuf);
+
                        obuf->len = len;
                        opipe->nrbufs++;
                        ibuf->offset += obuf->len;
@@ -1643,7 +1664,11 @@ static int link_pipe(struct pipe_inode_info *ipipe,
                 * Get a reference to this pipe buffer,
                 * so we can copy the contents over.
                 */
-               pipe_buf_get(ipipe, ibuf);
+               if (!pipe_buf_get(ipipe, ibuf)) {
+                       if (ret == 0)
+                               ret = -EFAULT;
+                       break;
+               }
 
                obuf = opipe->bufs + nbuf;
                *obuf = *ibuf;
@@ -1654,6 +1679,8 @@ static int link_pipe(struct pipe_inode_info *ipipe,
                 */
                obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
 
+               pipe_buf_mark_unmergeable(obuf);
+
                if (obuf->len > len)
                        obuf->len = len;