Merge branch 'splice-2.6.23' of git://git.kernel.dk/data/git/linux-2.6-block

* 'splice-2.6.23' of git://git.kernel.dk/data/git/linux-2.6-block:
  splice: fix offset mangling with direct splicing (sendfile)
  security: revalidate rw permissions for sys_splice and sys_vmsplice
  relay: fixup kerneldoc comment
  relay: fix bogus cast in subbuf_splice_actor()

2 files changed, 24 insertions, 25 deletions

diff --git a/fs/splice.c b/fs/splice.c
index ed2ce995475c..6c9828651e6f 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -28,6 +28,7 @@
 #include <linux/module.h>
 #include <linux/syscalls.h>
 #include <linux/uio.h>
+#include <linux/security.h>
 
 /*
  * Attempt to steal a page from a pipe buffer. This should perhaps go into
@@ -491,7 +492,7 @@ ssize_t generic_file_splice_read(struct file *in, loff_t *ppos,
 
         ret = 0;
         spliced = 0;
-        while (len) {
+        while (len && !spliced) {
                 ret = __generic_file_splice_read(in, ppos, pipe, len, flags);
 
                 if (ret < 0)
@@ -961,6 +962,10 @@ static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
         if (unlikely(ret < 0))
                 return ret;
 
+        ret = security_file_permission(out, MAY_WRITE);
+        if (unlikely(ret < 0))
+                return ret;
+
         return out->f_op->splice_write(pipe, out, ppos, len, flags);
 }
 
@@ -983,6 +988,10 @@ static long do_splice_to(struct file *in, loff_t *ppos,
         if (unlikely(ret < 0))
                 return ret;
 
+        ret = security_file_permission(in, MAY_READ);
+        if (unlikely(ret < 0))
+                return ret;
+
         return in->f_op->splice_read(in, ppos, pipe, len, flags);
 }
 
@@ -1051,15 +1060,10 @@ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd,
         sd->flags &= ~SPLICE_F_NONBLOCK;
 
         while (len) {
-                size_t read_len, max_read_len;
-
-                /*
-                 * Do at most PIPE_BUFFERS pages worth of transfer:
-                 */
-                max_read_len = min(len, (size_t)(PIPE_BUFFERS*PAGE_SIZE));
+                size_t read_len;
 
-                ret = do_splice_to(in, &sd->pos, pipe, max_read_len, flags);
-                if (unlikely(ret < 0))
+                ret = do_splice_to(in, &sd->pos, pipe, len, flags);
+                if (unlikely(ret <= 0))
                         goto out_release;
 
                 read_len = ret;
@@ -1071,26 +1075,17 @@ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd,
                  * could get stuck data in the internal pipe:
                  */
                 ret = actor(pipe, sd);
-                if (unlikely(ret < 0))
+                if (unlikely(ret <= 0))
                         goto out_release;
 
                 bytes += ret;
                 len -= ret;
 
-                /*
-                 * In nonblocking mode, if we got back a short read then
-                 * that was due to either an IO error or due to the
-                 * pagecache entry not being there. In the IO error case
-                 * the _next_ splice attempt will produce a clean IO error
-                 * return value (not a short read), so in both cases it's
-                 * correct to break out of the loop here:
-                 */
-                if ((flags & SPLICE_F_NONBLOCK) && (read_len < max_read_len))
-                        break;
+                if (ret < read_len)
+                        goto out_release;
         }
 
         pipe->nrbufs = pipe->curbuf = 0;
-
         return bytes;
 
 out_release:
@@ -1152,10 +1147,12 @@ long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
                 .pos            = *ppos,
                 .u.file         = out,
         };
-        size_t ret;
+        long ret;
 
         ret = splice_direct_to_actor(in, &sd, direct_splice_actor);
-        *ppos = sd.pos;
+        if (ret > 0)
+                *ppos += ret;
+
         return ret;
 }
 
diff --git a/kernel/relay.c b/kernel/relay.c
index 3b299fb3855c..a615a8f513fc 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -1061,7 +1061,7 @@ static struct pipe_buf_operations relay_pipe_buf_ops = {
         .get = generic_pipe_buf_get,
 };
 
-/**
+/*
  *      subbuf_splice_actor - splice up to one subbuf's worth of data
  */
 static int subbuf_splice_actor(struct file *in,
@@ -1074,7 +1074,9 @@ static int subbuf_splice_actor(struct file *in,
         unsigned int pidx, poff, total_len, subbuf_pages, ret;
         struct rchan_buf *rbuf = in->private_data;
         unsigned int subbuf_size = rbuf->chan->subbuf_size;
-        size_t read_start = ((size_t)*ppos) % rbuf->chan->alloc_size;
+        uint64_t pos = (uint64_t) *ppos;
+        uint32_t alloc_size = (uint32_t) rbuf->chan->alloc_size;
+        size_t read_start = (size_t) do_div(pos, alloc_size);
         size_t read_subbuf = read_start / subbuf_size;
         size_t padding = rbuf->padding[read_subbuf];
         size_t nonpad_end = read_subbuf * subbuf_size + subbuf_size - padding;