}
#endif
+static int
+hugetlbfs_read_actor(struct page *page, unsigned long offset,
+ char __user *buf, unsigned long count,
+ unsigned long size)
+{
+ char *kaddr;
+ unsigned long left, copied = 0;
+ int i, chunksize;
+
+ if (size > count)
+ size = count;
+
+ /* Find which 4k chunk and offset with in that chunk */
+ i = offset >> PAGE_CACHE_SHIFT;
+ offset = offset & ~PAGE_CACHE_MASK;
+
+ while (size) {
+ chunksize = PAGE_CACHE_SIZE;
+ if (offset)
+ chunksize -= offset;
+ if (chunksize > size)
+ chunksize = size;
+ kaddr = kmap(&page[i]);
+ left = __copy_to_user(buf, kaddr + offset, chunksize);
+ kunmap(&page[i]);
+ if (left) {
+ copied += (chunksize - left);
+ break;
+ }
+ offset = 0;
+ size -= chunksize;
+ buf += chunksize;
+ copied += chunksize;
+ i++;
+ }
+ return copied ? copied : -EFAULT;
+}
+
+/*
+ * Support for read() - Find the page attached to f_mapping and copy out the
+ * data. Its *very* similar to do_generic_mapping_read(), we can't use that
+ * since it has PAGE_CACHE_SIZE assumptions.
+ */
+static ssize_t hugetlbfs_read(struct file *filp, char __user *buf,
+ size_t len, loff_t *ppos)
+{
+ struct address_space *mapping = filp->f_mapping;
+ struct inode *inode = mapping->host;
+ unsigned long index = *ppos >> HPAGE_SHIFT;
+ unsigned long offset = *ppos & ~HPAGE_MASK;
+ unsigned long end_index;
+ loff_t isize;
+ ssize_t retval = 0;
+
+ mutex_lock(&inode->i_mutex);
+
+ /* validate length */
+ if (len == 0)
+ goto out;
+
+ isize = i_size_read(inode);
+ if (!isize)
+ goto out;
+
+ end_index = (isize - 1) >> HPAGE_SHIFT;
+ for (;;) {
+ struct page *page;
+ int nr, ret;
+
+ /* nr is the maximum number of bytes to copy from this page */
+ nr = HPAGE_SIZE;
+ if (index >= end_index) {
+ if (index > end_index)
+ goto out;
+ nr = ((isize - 1) & ~HPAGE_MASK) + 1;
+ if (nr <= offset) {
+ goto out;
+ }
+ }
+ nr = nr - offset;
+
+ /* Find the page */
+ page = find_get_page(mapping, index);
+ if (unlikely(page == NULL)) {
+ /*
+ * We have a HOLE, zero out the user-buffer for the
+ * length of the hole or request.
+ */
+ ret = len < nr ? len : nr;
+ if (clear_user(buf, ret))
+ ret = -EFAULT;
+ } else {
+ /*
+ * We have the page, copy it to user space buffer.
+ */
+ ret = hugetlbfs_read_actor(page, offset, buf, len, nr);
+ }
+ if (ret < 0) {
+ if (retval == 0)
+ retval = ret;
+ if (page)
+ page_cache_release(page);
+ goto out;
+ }
+
+ offset += ret;
+ retval += ret;
+ len -= ret;
+ index += offset >> HPAGE_SHIFT;
+ offset &= ~HPAGE_MASK;
+
+ if (page)
+ page_cache_release(page);
+
+ /* short read or no more work */
+ if ((ret != nr) || (len == 0))
+ break;
+ }
+out:
+ *ppos = ((loff_t)index << HPAGE_SHIFT) + offset;
+ mutex_unlock(&inode->i_mutex);
+ return retval;
+}
+
/*
* Read a page. Again trivial. If it didn't already exist
* in the page cache, it is zero-filled.
return -EINVAL;
}
-static int hugetlbfs_prepare_write(struct file *file,
- struct page *page, unsigned offset, unsigned to)
+static int hugetlbfs_write_begin(struct file *file,
+ struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
{
return -EINVAL;
}
-static int hugetlbfs_commit_write(struct file *file,
- struct page *page, unsigned offset, unsigned to)
+static int hugetlbfs_write_end(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
{
+ BUG();
return -EINVAL;
}
}
}
-/*
- * Expanding truncates are not allowed.
- */
static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
{
pgoff_t pgoff;
struct address_space *mapping = inode->i_mapping;
- if (offset > inode->i_size)
- return -EINVAL;
-
BUG_ON(offset & ~HPAGE_MASK);
pgoff = offset >> PAGE_SHIFT;
- inode->i_size = offset;
+ i_size_write(inode, offset);
spin_lock(&mapping->i_mmap_lock);
if (!prio_tree_empty(&mapping->i_mmap))
hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff);
static const struct address_space_operations hugetlbfs_aops = {
.readpage = hugetlbfs_readpage,
- .prepare_write = hugetlbfs_prepare_write,
- .commit_write = hugetlbfs_commit_write,
+ .write_begin = hugetlbfs_write_begin,
+ .write_end = hugetlbfs_write_end,
.set_page_dirty = hugetlbfs_set_page_dirty,
};
}
const struct file_operations hugetlbfs_file_operations = {
+ .read = hugetlbfs_read,
.mmap = hugetlbfs_file_mmap,
.fsync = simple_sync_file,
.get_unmapped_area = hugetlb_get_unmapped_area,
int error;
struct vfsmount *vfsmount;
+ error = bdi_init(&hugetlbfs_backing_dev_info);
+ if (error)
+ return error;
+
hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache",
sizeof(struct hugetlbfs_inode_info),
0, 0, init_once);
if (hugetlbfs_inode_cachep == NULL)
- return -ENOMEM;
+ goto out2;
error = register_filesystem(&hugetlbfs_fs_type);
if (error)
out:
if (error)
kmem_cache_destroy(hugetlbfs_inode_cachep);
+ out2:
+ bdi_destroy(&hugetlbfs_backing_dev_info);
return error;
}
{
kmem_cache_destroy(hugetlbfs_inode_cachep);
unregister_filesystem(&hugetlbfs_fs_type);
+ bdi_destroy(&hugetlbfs_backing_dev_info);
}
module_init(init_hugetlbfs_fs)
projects / mirror_ubuntu-zesty-kernel.git / blobdiff