3 files changed, 43 insertions, 38 deletions

diff --git a/fs/compat.c b/fs/compat.c
index 3f3e8f4d43d6..970888aad843 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -1323,7 +1323,7 @@ compat_sys_vmsplice(int fd, const struct compat_iovec __user *iov32,
 {
         unsigned i;
         struct iovec *iov;
-        if (nr_segs >= UIO_MAXIOV)
+        if (nr_segs > UIO_MAXIOV)
                 return -EINVAL;
         iov = compat_alloc_user_space(nr_segs * sizeof(struct iovec));
         for (i = 0; i < nr_segs; i++) {
diff --git a/fs/splice.c b/fs/splice.c
index 7fb04970c72d..a285fd746dc0 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -51,7 +51,7 @@ struct splice_pipe_desc {
  * addition of remove_mapping(). If success is returned, the caller may
  * attempt to reuse this page for another destination.
  */
-static int page_cache_pipe_buf_steal(struct pipe_inode_info *info,
+static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe,
                                      struct pipe_buffer *buf)
 {
         struct page *page = buf->page;
@@ -78,16 +78,18 @@ static int page_cache_pipe_buf_steal(struct pipe_inode_info *info,
                 return 1;
         }
 
+        buf->flags |= PIPE_BUF_FLAG_LRU;
         return 0;
 }
 
-static void page_cache_pipe_buf_release(struct pipe_inode_info *info,
+static void page_cache_pipe_buf_release(struct pipe_inode_info *pipe,
                                         struct pipe_buffer *buf)
 {
         page_cache_release(buf->page);
+        buf->flags &= ~PIPE_BUF_FLAG_LRU;
 }
 
-static int page_cache_pipe_buf_pin(struct pipe_inode_info *info,
+static int page_cache_pipe_buf_pin(struct pipe_inode_info *pipe,
                                    struct pipe_buffer *buf)
 {
         struct page *page = buf->page;
@@ -141,6 +143,7 @@ static int user_page_pipe_buf_steal(struct pipe_inode_info *pipe,
         if (!(buf->flags & PIPE_BUF_FLAG_GIFT))
                 return 1;
 
+        buf->flags |= PIPE_BUF_FLAG_LRU;
         return generic_pipe_buf_steal(pipe, buf);
 }
 
@@ -321,6 +324,8 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
                                               mapping_gfp_mask(mapping));
                         if (unlikely(error)) {
                                 page_cache_release(page);
+                                if (error == -EEXIST)
+                                        continue;
                                 break;
                         }
                         /*
@@ -497,14 +502,14 @@ EXPORT_SYMBOL(generic_file_splice_read);
  * Send 'sd->len' bytes to socket from 'sd->file' at position 'sd->pos'
  * using sendpage(). Return the number of bytes sent.
  */
-static int pipe_to_sendpage(struct pipe_inode_info *info,
+static int pipe_to_sendpage(struct pipe_inode_info *pipe,
                             struct pipe_buffer *buf, struct splice_desc *sd)
 {
         struct file *file = sd->file;
         loff_t pos = sd->pos;
         int ret, more;
 
-        ret = buf->ops->pin(info, buf);
+        ret = buf->ops->pin(pipe, buf);
         if (!ret) {
                 more = (sd->flags & SPLICE_F_MORE) || sd->len < sd->total_len;
 
@@ -535,7 +540,7 @@ static int pipe_to_sendpage(struct pipe_inode_info *info,
  * SPLICE_F_MOVE isn't set, or we cannot move the page, we simply create
  * a new page in the output file page cache and fill/dirty that.
  */
-static int pipe_to_file(struct pipe_inode_info *info, struct pipe_buffer *buf,
+static int pipe_to_file(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
                         struct splice_desc *sd)
 {
         struct file *file = sd->file;
@@ -549,7 +554,7 @@ static int pipe_to_file(struct pipe_inode_info *info, struct pipe_buffer *buf,
         /*
          * make sure the data in this buffer is uptodate
          */
-        ret = buf->ops->pin(info, buf);
+        ret = buf->ops->pin(pipe, buf);
         if (unlikely(ret))
                 return ret;
 
@@ -566,37 +571,23 @@ static int pipe_to_file(struct pipe_inode_info *info, struct pipe_buffer *buf,
          */
         if ((sd->flags & SPLICE_F_MOVE) && this_len == PAGE_CACHE_SIZE) {
                 /*
-                 * If steal succeeds, buf->page is now pruned from the vm
-                 * side (page cache) and we can reuse it. The page will also
-                 * be locked on successful return.
+                 * If steal succeeds, buf->page is now pruned from the
+                 * pagecache and we can reuse it. The page will also be
+                 * locked on successful return.
                  */
-                if (buf->ops->steal(info, buf))
+                if (buf->ops->steal(pipe, buf))
                         goto find_page;
 
                 page = buf->page;
-                page_cache_get(page);
-
-                /*
-                 * page must be on the LRU for adding to the pagecache.
-                 * Check this without grabbing the zone lock, if it isn't
-                 * the do grab the zone lock, recheck, and add if necessary.
-                 */
-                if (!PageLRU(page)) {
-                        struct zone *zone = page_zone(page);
-
-                        spin_lock_irq(&zone->lru_lock);
-                        if (!PageLRU(page)) {
-                                SetPageLRU(page);
-                                add_page_to_inactive_list(zone, page);
-                        }
-                        spin_unlock_irq(&zone->lru_lock);
-                }
-
                 if (add_to_page_cache(page, mapping, index, gfp_mask)) {
-                        page_cache_release(page);
                         unlock_page(page);
                         goto find_page;
                 }
+
+                page_cache_get(page);
+
+                if (!(buf->flags & PIPE_BUF_FLAG_LRU))
+                        lru_cache_add(page);
         } else {
 find_page:
                 page = find_lock_page(mapping, index);
@@ -647,23 +638,36 @@ find_page:
         }
 
         ret = mapping->a_ops->prepare_write(file, page, offset, offset+this_len);
-        if (ret == AOP_TRUNCATED_PAGE) {
+        if (unlikely(ret)) {
+                loff_t isize = i_size_read(mapping->host);
+
+                if (ret != AOP_TRUNCATED_PAGE)
+                        unlock_page(page);
                 page_cache_release(page);
-                goto find_page;
-        } else if (ret)
+                if (ret == AOP_TRUNCATED_PAGE)
+                        goto find_page;
+
+                /*
+                 * prepare_write() may have instantiated a few blocks
+                 * outside i_size.  Trim these off again.
+                 */
+                if (sd->pos + this_len > isize)
+                        vmtruncate(mapping->host, isize);
+
                 goto out;
+        }
 
         if (buf->page != page) {
                 /*
                  * Careful, ->map() uses KM_USER0!
                  */
-                char *src = buf->ops->map(info, buf, 1);
+                char *src = buf->ops->map(pipe, buf, 1);
                 char *dst = kmap_atomic(page, KM_USER1);
 
                 memcpy(dst + offset, src + buf->offset, this_len);
                 flush_dcache_page(page);
                 kunmap_atomic(dst, KM_USER1);
-                buf->ops->unmap(info, buf, src);
+                buf->ops->unmap(pipe, buf, src);
         }
 
         ret = mapping->a_ops->commit_write(file, page, offset, offset+this_len);
diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h
index ba73108cbf8b..ea4f7cd7bfd8 100644
--- a/include/linux/pipe_fs_i.h
+++ b/include/linux/pipe_fs_i.h
@@ -5,8 +5,9 @@
 
 #define PIPE_BUFFERS (16)
 
-#define PIPE_BUF_FLAG_ATOMIC    0x01    /* was atomically mapped */
-#define PIPE_BUF_FLAG_GIFT      0x02    /* page is a gift */
+#define PIPE_BUF_FLAG_LRU       0x01    /* page is on the LRU */
+#define PIPE_BUF_FLAG_ATOMIC    0x02    /* was atomically mapped */
+#define PIPE_BUF_FLAG_GIFT      0x04    /* page is a gift */
 
 struct pipe_buffer {
         struct page *page;