ext4: add read support for inline data
Let readpage and readpages handle the case when we want to read an
inlined file.
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index bec68b3..e4a41d5 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -454,6 +454,67 @@
return error;
}
+static int ext4_read_inline_page(struct inode *inode, struct page *page)
+{
+ void *kaddr;
+ int ret = 0;
+ size_t len;
+ struct ext4_iloc iloc;
+
+ BUG_ON(!PageLocked(page));
+ BUG_ON(!ext4_has_inline_data(inode));
+ BUG_ON(page->index);
+
+ if (!EXT4_I(inode)->i_inline_off) {
+ ext4_warning(inode->i_sb, "inode %lu doesn't have inline data.",
+ inode->i_ino);
+ goto out;
+ }
+
+ ret = ext4_get_inode_loc(inode, &iloc);
+ if (ret)
+ goto out;
+
+ len = min_t(size_t, ext4_get_inline_size(inode), i_size_read(inode));
+ kaddr = kmap_atomic(page);
+ ret = ext4_read_inline_data(inode, kaddr, len, &iloc);
+ flush_dcache_page(page);
+ kunmap_atomic(kaddr);
+ zero_user_segment(page, len, PAGE_CACHE_SIZE);
+ SetPageUptodate(page);
+ brelse(iloc.bh);
+
+out:
+ return ret;
+}
+
+int ext4_readpage_inline(struct inode *inode, struct page *page)
+{
+ int ret = 0;
+
+ down_read(&EXT4_I(inode)->xattr_sem);
+ if (!ext4_has_inline_data(inode)) {
+ up_read(&EXT4_I(inode)->xattr_sem);
+ return -EAGAIN;
+ }
+
+ /*
+ * Current inline data can only exist in the 1st page,
+ * So for all the other pages, just set them uptodate.
+ */
+ if (!page->index)
+ ret = ext4_read_inline_page(inode, page);
+ else if (!PageUptodate(page)) {
+ zero_user_segment(page, 0, PAGE_CACHE_SIZE);
+ SetPageUptodate(page);
+ }
+
+ up_read(&EXT4_I(inode)->xattr_sem);
+
+ unlock_page(page);
+ return ret >= 0 ? 0 : ret;
+}
+
int ext4_destroy_inline_data(handle_t *handle, struct inode *inode)
{
int ret;