1 files changed, 34 insertions, 6 deletions

diff --git a/fs/pipe.c b/fs/pipe.c
index a932ced92a1..fec5e4ad071 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -13,6 +13,7 @@
 #include <linux/fs.h>
 #include <linux/log2.h>
 #include <linux/mount.h>
+#include <linux/magic.h>
 #include <linux/pipe_fs_i.h>
 #include <linux/uio.h>
 #include <linux/highmem.h>
@@ -230,7 +231,7 @@ void *generic_pipe_buf_map(struct pipe_inode_info *pipe,
 {
         if (atomic) {
                 buf->flags |= PIPE_BUF_FLAG_ATOMIC;
-                return kmap_atomic(buf->page, KM_USER0);
+                return kmap_atomic(buf->page);
         }
 
         return kmap(buf->page);
@@ -251,7 +252,7 @@ void generic_pipe_buf_unmap(struct pipe_inode_info *pipe,
 {
         if (buf->flags & PIPE_BUF_FLAG_ATOMIC) {
                 buf->flags &= ~PIPE_BUF_FLAG_ATOMIC;
-                kunmap_atomic(map_data, KM_USER0);
+                kunmap_atomic(map_data);
         } else
                 kunmap(buf->page);
 }
@@ -345,6 +346,16 @@ static const struct pipe_buf_operations anon_pipe_buf_ops = {
         .get = generic_pipe_buf_get,
 };
 
+static const struct pipe_buf_operations packet_pipe_buf_ops = {
+        .can_merge = 0,
+        .map = generic_pipe_buf_map,
+        .unmap = generic_pipe_buf_unmap,
+        .confirm = generic_pipe_buf_confirm,
+        .release = anon_pipe_buf_release,
+        .steal = generic_pipe_buf_steal,
+        .get = generic_pipe_buf_get,
+};
+
 static ssize_t
 pipe_read(struct kiocb *iocb, const struct iovec *_iov,
            unsigned long nr_segs, loff_t pos)
@@ -406,6 +417,13 @@ redo:
                         ret += chars;
                         buf->offset += chars;
                         buf->len -= chars;
+
+                        /* Was it a packet buffer? Clean up and exit */
+                        if (buf->flags & PIPE_BUF_FLAG_PACKET) {
+                                total_len = chars;
+                                buf->len = 0;
+                        }
+
                         if (!buf->len) {
                                 buf->ops = NULL;
                                 ops->release(pipe, buf);
@@ -458,6 +476,11 @@ redo:
         return ret;
 }
 
+static inline int is_packetized(struct file *file)
+{
+        return (file->f_flags & O_DIRECT) != 0;
+}
+
 static ssize_t
 pipe_write(struct kiocb *iocb, const struct iovec *_iov,
             unsigned long nr_segs, loff_t ppos)
@@ -565,14 +588,14 @@ redo1:
                         iov_fault_in_pages_read(iov, chars);
 redo2:
                         if (atomic)
-                                src = kmap_atomic(page, KM_USER0);
+                                src = kmap_atomic(page);
                         else
                                 src = kmap(page);
 
                         error = pipe_iov_copy_from_user(src, iov, chars,
                                                         atomic);
                         if (atomic)
-                                kunmap_atomic(src, KM_USER0);
+                                kunmap_atomic(src);
                         else
                                 kunmap(page);
 
@@ -592,6 +615,11 @@ redo2:
                         buf->ops = &anon_pipe_buf_ops;
                         buf->offset = 0;
                         buf->len = chars;
+                        buf->flags = 0;
+                        if (is_packetized(filp)) {
+                                buf->ops = &packet_pipe_buf_ops;
+                                buf->flags = PIPE_BUF_FLAG_PACKET;
+                        }
                         pipe->nrbufs = ++bufs;
                         pipe->tmp_page = NULL;
 
@@ -1012,7 +1040,7 @@ struct file *create_write_pipe(int flags)
                 goto err_dentry;
         f->f_mapping = inode->i_mapping;
 
-        f->f_flags = O_WRONLY | (flags & O_NONBLOCK);
+        f->f_flags = O_WRONLY | (flags & (O_NONBLOCK | O_DIRECT));
         f->f_version = 0;
 
         return f;
@@ -1056,7 +1084,7 @@ int do_pipe_flags(int *fd, int flags)
         int error;
         int fdw, fdr;
 
-        if (flags & ~(O_CLOEXEC | O_NONBLOCK))
+        if (flags & ~(O_CLOEXEC | O_NONBLOCK | O_DIRECT))
                 return -EINVAL;
 
         fw = create_write_pipe(flags);