ceph: fix reading inline data when i_size > PAGE_SIZE

when inode has inline data but its size > PAGE_SIZE (it was truncated
to larger size), previous direct read code return -EIO. This patch adds
code to return zeros for data whose offset > PAGE_SIZE.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

2 files changed, 26 insertions, 15 deletions

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index c81c0e004588..7d05e37874d4 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -196,17 +196,22 @@ static int readpage_nounlock(struct file *filp, struct page *page)
         u64 len = PAGE_CACHE_SIZE;
 
         if (off >= i_size_read(inode)) {
-                zero_user_segment(page, err, PAGE_CACHE_SIZE);
+                zero_user_segment(page, 0, PAGE_CACHE_SIZE);
                 SetPageUptodate(page);
                 return 0;
         }
 
-        /*
-         * Uptodate inline data should have been added into page cache
-         * while getting Fcr caps.
-         */
-        if (ci->i_inline_version != CEPH_INLINE_NONE)
-                return -EINVAL;
+        if (ci->i_inline_version != CEPH_INLINE_NONE) {
+                /*
+                 * Uptodate inline data should have been added
+                 * into page cache while getting Fcr caps.
+                 */
+                if (off == 0)
+                        return -EINVAL;
+                zero_user_segment(page, 0, PAGE_CACHE_SIZE);
+                SetPageUptodate(page);
+                return 0;
+        }
 
         err = ceph_readpage_from_fscache(inode, page);
         if (err == 0)
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 663da44c06b6..c407abb52b7b 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -879,28 +879,34 @@ again:
 
                 i_size = i_size_read(inode);
                 if (retry_op == READ_INLINE) {
-                        /* does not support inline data > PAGE_SIZE */
-                        if (i_size > PAGE_CACHE_SIZE) {
-                                ret = -EIO;
-                        } else if (iocb->ki_pos < i_size) {
+                        BUG_ON(ret > 0 || read > 0);
+                        if (iocb->ki_pos < i_size &&
+                            iocb->ki_pos < PAGE_CACHE_SIZE) {
                                 loff_t end = min_t(loff_t, i_size,
                                                    iocb->ki_pos + len);
+                                end = min_t(loff_t, end, PAGE_CACHE_SIZE);
                                 if (statret < end)
                                         zero_user_segment(page, statret, end);
                                 ret = copy_page_to_iter(page,
                                                 iocb->ki_pos & ~PAGE_MASK,
                                                 end - iocb->ki_pos, to);
                                 iocb->ki_pos += ret;
-                        } else {
-                                ret = 0;
+                                read += ret;
+                        }
+                        if (iocb->ki_pos < i_size && read < len) {
+                                size_t zlen = min_t(size_t, len - read,
+                                                    i_size - iocb->ki_pos);
+                                ret = iov_iter_zero(zlen, to);
+                                iocb->ki_pos += ret;
+                                read += ret;
                         }
                         __free_pages(page, 0);
-                        return ret;
+                        return read;
                 }
 
                 /* hit EOF or hole? */
                 if (retry_op == CHECK_EOF && iocb->ki_pos < i_size &&
-                        ret < len) {
+                    ret < len) {
                         dout("sync_read hit hole, ppos %lld < size %lld"
                              ", reading more\n", iocb->ki_pos,
                              inode->i_size);