From 972f0d3ab1a15cb5d790dd8c53903066084b28f2 Mon Sep 17 00:00:00 2001 From: Yehuda Sadeh Date: Thu, 4 Feb 2010 13:41:41 -0800 Subject: [PATCH] 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 Signed-off-by: Sage Weil --- fs/ceph/file.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) 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 @@ static void zero_page_vector_range(int off, int len, struct page **pages) { 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 @@ static int striped_read(struct inode *inode, 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 @@ more: dout("zero tail\n"); zero_page_vector_range(page_off + read, len - read, pages); + read = len; goto out; } -- 2.7.4