ceph: fix short synchronous reads
Zeroing of holes was not done correctly: page_off was miscalculated and
zeroing the tail didn't not adjust the 'read' value to include the zeroed
portion.
Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 2d88c80..43bd2f2 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -395,23 +395,22 @@
{
int i = off >> PAGE_CACHE_SHIFT;
+ off &= ~PAGE_CACHE_MASK;
+
dout("zero_page_vector_page %u~%u\n", off, len);
- BUG_ON(len < PAGE_CACHE_SIZE);
/* leading partial page? */
- if (off & ~PAGE_CACHE_MASK) {
+ if (off) {
+ int end = min((int)PAGE_CACHE_SIZE, off + len);
dout("zeroing %d %p head from %d\n", i, pages[i],
- (int)(off & ~PAGE_CACHE_MASK));
- zero_user_segment(pages[i], off & ~PAGE_CACHE_MASK,
- PAGE_CACHE_SIZE);
- off += PAGE_CACHE_SIZE;
- off &= PAGE_CACHE_MASK;
+ (int)off);
+ zero_user_segment(pages[i], off, end);
+ len -= (end - off);
i++;
}
while (len >= PAGE_CACHE_SIZE) {
dout("zeroing %d %p\n", i, pages[i]);
zero_user_segment(pages[i], 0, PAGE_CACHE_SIZE);
- off += PAGE_CACHE_SIZE;
len -= PAGE_CACHE_SIZE;
i++;
}
@@ -437,7 +436,7 @@
struct ceph_client *client = ceph_inode_to_client(inode);
struct ceph_inode_info *ci = ceph_inode(inode);
u64 pos, this_len;
- int page_off = off & ~PAGE_CACHE_SIZE; /* first byte's offset in page */
+ int page_off = off & ~PAGE_CACHE_MASK; /* first byte's offset in page */
int left, pages_left;
int read;
struct page **page_pos;
@@ -493,6 +492,7 @@
dout("zero tail\n");
zero_page_vector_range(page_off + read, len - read,
pages);
+ read = len;
goto out;
}