Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

[linux.git] / mm / shmem.c

diff --git a/mm/shmem.c b/mm/shmem.c
index 70273f8df5867a33aeea7267e4268a949a35aaaa..8f1a95406bae6a61b20be247b50603cdedc30398 100644 (file)
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1402,13 +1402,25 @@ shmem_write_end(struct file *file, struct address_space *mapping,
        return copied;
 }
 
-static void do_shmem_file_read(struct file *filp, loff_t *ppos, read_descriptor_t *desc, read_actor_t actor)
+static ssize_t shmem_file_aio_read(struct kiocb *iocb,
+               const struct iovec *iov, unsigned long nr_segs, loff_t pos)
 {
-       struct inode *inode = file_inode(filp);
+       struct file *file = iocb->ki_filp;
+       struct inode *inode = file_inode(file);
        struct address_space *mapping = inode->i_mapping;
        pgoff_t index;
        unsigned long offset;
        enum sgp_type sgp = SGP_READ;
+       int error;
+       ssize_t retval;
+       size_t count;
+       loff_t *ppos = &iocb->ki_pos;
+       struct iov_iter iter;
+
+       retval = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE);
+       if (retval)
+               return retval;
+       iov_iter_init(&iter, iov, nr_segs, count, 0);
 
        /*
         * Might this read be for a stacking filesystem?  Then when reading
@@ -1436,10 +1448,10 @@ static void do_shmem_file_read(struct file *filp, loff_t *ppos, read_descriptor_
                                break;
                }
 
-               desc->error = shmem_getpage(inode, index, &page, sgp, NULL);
-               if (desc->error) {
-                       if (desc->error == -EINVAL)
-                               desc->error = 0;
+               error = shmem_getpage(inode, index, &page, sgp, NULL);
+               if (error) {
+                       if (error == -EINVAL)
+                               error = 0;
                        break;
                }
                if (page)
@@ -1483,61 +1495,26 @@ static void do_shmem_file_read(struct file *filp, loff_t *ppos, read_descriptor_
                /*
                 * Ok, we have the page, and it's up-to-date, so
                 * now we can copy it to user space...
-                *
-                * The actor routine returns how many bytes were actually used..
-                * NOTE! This may not be the same as how much of a user buffer
-                * we filled up (we may be padding etc), so we can only update
-                * "pos" here (the actor routine has to update the user buffer
-                * pointers and the remaining count).
                 */
-               ret = actor(desc, page, offset, nr);
+               ret = copy_page_to_iter(page, offset, nr, &iter);
+               retval += ret;
                offset += ret;
                index += offset >> PAGE_CACHE_SHIFT;
                offset &= ~PAGE_CACHE_MASK;
 
                page_cache_release(page);
-               if (ret != nr || !desc->count)
+               if (!iov_iter_count(&iter))
                        break;
-
+               if (ret < nr) {
+                       error = -EFAULT;
+                       break;
+               }
                cond_resched();
        }
 
        *ppos = ((loff_t) index << PAGE_CACHE_SHIFT) + offset;
-       file_accessed(filp);
-}
-
-static ssize_t shmem_file_aio_read(struct kiocb *iocb,
-               const struct iovec *iov, unsigned long nr_segs, loff_t pos)
-{
-       struct file *filp = iocb->ki_filp;
-       ssize_t retval;
-       unsigned long seg;
-       size_t count;
-       loff_t *ppos = &iocb->ki_pos;
-
-       retval = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE);
-       if (retval)
-               return retval;
-
-       for (seg = 0; seg < nr_segs; seg++) {
-               read_descriptor_t desc;
-
-               desc.written = 0;
-               desc.arg.buf = iov[seg].iov_base;
-               desc.count = iov[seg].iov_len;
-               if (desc.count == 0)
-                       continue;
-               desc.error = 0;
-               do_shmem_file_read(filp, ppos, &desc, file_read_actor);
-               retval += desc.written;
-               if (desc.error) {
-                       retval = retval ?: desc.error;
-                       break;
-               }
-               if (desc.count > 0)
-                       break;
-       }
-       return retval;
+       file_accessed(file);
+       return retval ? retval : error;
 }
 
 static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos,
@@ -1576,7 +1553,7 @@ static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos,
        index = *ppos >> PAGE_CACHE_SHIFT;
        loff = *ppos & ~PAGE_CACHE_MASK;
        req_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
-       nr_pages = min(req_pages, pipe->buffers);
+       nr_pages = min(req_pages, spd.nr_pages_max);
 
        spd.nr_pages = find_get_pages_contig(mapping, index,
                                                nr_pages, spd.pages);