From 0d66a487c120012f33fbcd6af5cbf0a0cad71557 Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Thu, 4 Aug 2011 08:21:30 -0700 Subject: ceph: implement (optional) max read size The 'rsize' mount option limits the maximum size of an individual read(ahead) operation that is sent off to an OSD. This is distinct from 'rasize', which controls the size of the readahead window. Signed-off-by: Sage Weil --- fs/ceph/addr.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c index 5bb39a50f90..5ffee90d9fb 100644 --- a/fs/ceph/addr.c +++ b/fs/ceph/addr.c @@ -268,7 +268,7 @@ static void finish_read(struct ceph_osd_request *req, struct ceph_msg *msg) * start an async read(ahead) operation. return nr_pages we submitted * a read for on success, or negative error code. */ -static int start_read(struct inode *inode, struct list_head *page_list) +static int start_read(struct inode *inode, struct list_head *page_list, int max) { struct ceph_osd_client *osdc = &ceph_inode_to_client(inode)->client->osdc; @@ -292,6 +292,8 @@ static int start_read(struct inode *inode, struct list_head *page_list) break; nr_pages++; next_index++; + if (max && nr_pages == max) + break; } len = nr_pages << PAGE_CACHE_SHIFT; dout("start_read %p nr_pages %d is %lld~%lld\n", inode, nr_pages, @@ -358,11 +360,18 @@ static int ceph_readpages(struct file *file, struct address_space *mapping, struct list_head *page_list, unsigned nr_pages) { struct inode *inode = file->f_dentry->d_inode; + struct ceph_fs_client *fsc = ceph_inode_to_client(inode); int rc = 0; + int max = 0; + + if (fsc->mount_options->rsize >= PAGE_CACHE_SIZE) + max = (fsc->mount_options->rsize + PAGE_CACHE_SIZE - 1) + >> PAGE_SHIFT; - dout("readpages %p file %p nr_pages %d\n", inode, file, nr_pages); + dout("readpages %p file %p nr_pages %d max %d\n", inode, file, nr_pages, + max); while (!list_empty(page_list)) { - rc = start_read(inode, page_list); + rc = start_read(inode, page_list, max); if (rc < 0) goto out; BUG_ON(rc == 0); -- cgit v1.2.3