ceph: writeback congestion control

[net-next-2.6.git] / fs / ceph / addr.c

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index d0cdceb0b90bfa9b87922492048ee58c5d8ca473..a6850a14038e17c88df3c468048716854d1e34bc 100644 (file)
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -47,6 +47,12 @@
  * accounting is preserved.
  */
 
+#define CONGESTION_ON_THRESH(congestion_kb) (congestion_kb >> (PAGE_SHIFT-10))
+#define CONGESTION_OFF_THRESH(congestion_kb)                           \
+       (CONGESTION_ON_THRESH(congestion_kb) -                          \
+        (CONGESTION_ON_THRESH(congestion_kb) >> 2))
+
+
 
 /*
  * Dirty a page.  Optimistically adjust accounting, on the assumption
@@ -377,6 +383,7 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
 {
        struct inode *inode;
        struct ceph_inode_info *ci;
+       struct ceph_client *client;
        struct ceph_osd_client *osdc;
        loff_t page_off = page->index << PAGE_CACHE_SHIFT;
        int len = PAGE_CACHE_SIZE;
@@ -384,6 +391,7 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
        int err = 0;
        struct ceph_snap_context *snapc;
        u64 snap_size = 0;
+       long writeback_stat;
 
        dout("writepage %p idx %lu\n", page, page->index);
 
@@ -393,7 +401,8 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
        }
        inode = page->mapping->host;
        ci = ceph_inode(inode);
-       osdc = &ceph_inode_to_client(inode)->osdc;
+       client = ceph_inode_to_client(inode);
+       osdc = &client->osdc;
 
        /* verify this is a writeable snap context */
        snapc = (void *)page->private;
@@ -420,6 +429,11 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
        dout("writepage %p page %p index %lu on %llu~%u\n",
             inode, page, page->index, page_off, len);
 
+       writeback_stat = atomic_long_inc_return(&client->writeback_count);
+       if (writeback_stat >
+           CONGESTION_ON_THRESH(client->mount_args->congestion_kb))
+               set_bdi_congested(&client->backing_dev_info, BLK_RW_ASYNC);
+
        set_page_writeback(page);
        err = ceph_osdc_writepages(osdc, ceph_vino(inode),
                                   &ci->i_layout, snapc,
@@ -499,6 +513,8 @@ static void writepages_finish(struct ceph_osd_request *req,
        struct writeback_control *wbc = req->r_wbc;
        __s32 rc = -EIO;
        u64 bytes = 0;
+       struct ceph_client *client = ceph_inode_to_client(inode);
+       long writeback_stat;
 
        /* parse reply */
        replyhead = msg->front.iov_base;
@@ -524,6 +540,13 @@ static void writepages_finish(struct ceph_osd_request *req,
                BUG_ON(!page);
                WARN_ON(!PageUptodate(page));
 
+               writeback_stat =
+                       atomic_long_dec_return(&client->writeback_count);
+               if (writeback_stat <
+                   CONGESTION_OFF_THRESH(client->mount_args->congestion_kb))
+                       clear_bdi_congested(&client->backing_dev_info,
+                                           BLK_RW_ASYNC);
+
                if (i >= wrote) {
                        dout("inode %p skipping page %p\n", inode, page);
                        wbc->pages_skipped++;
@@ -666,6 +689,7 @@ retry:
                u64 offset, len;
                struct ceph_osd_request_head *reqhead;
                struct ceph_osd_op *op;
+               long writeback_stat;
 
                next = 0;
                locked_pages = 0;
@@ -773,6 +797,12 @@ get_more_pages:
                                first = i;
                        dout("%p will write page %p idx %lu\n",
                             inode, page, page->index);
+
+                       writeback_stat = atomic_long_inc_return(&client->writeback_count);
+                       if (writeback_stat > CONGESTION_ON_THRESH(client->mount_args->congestion_kb)) {
+                               set_bdi_congested(&client->backing_dev_info, BLK_RW_ASYNC);
+                       }
+
                        set_page_writeback(page);
                        req->r_pages[locked_pages] = page;
                        locked_pages++;
@@ -998,7 +1028,8 @@ static int ceph_write_end(struct file *file, struct address_space *mapping,
                          struct page *page, void *fsdata)
 {
        struct inode *inode = file->f_dentry->d_inode;
-       struct ceph_mds_client *mdsc = &ceph_inode_to_client(inode)->mdsc;
+       struct ceph_client *client = ceph_inode_to_client(inode);
+       struct ceph_mds_client *mdsc = &client->mdsc;
        unsigned from = pos & (PAGE_CACHE_SIZE - 1);
        int check_cap = 0;