LU-1030 osc: new IO engine implementation

[fs/lustre-release.git] / lustre / llite / vvp_page.c

diff --git a/lustre/llite/vvp_page.c b/lustre/llite/vvp_page.c
index bc0e2b1..990d59b 100644 (file)
--- a/lustre/llite/vvp_page.c
+++ b/lustre/llite/vvp_page.c
@@ -36,6 +36,7 @@
  * Implementation of cl_page for VVP layer.
  *
  *   Author: Nikita Danilov <nikita.danilov@sun.com>
+ *   Author: Jinshan Xiong <jinshan.xiong@whamcloud.com>
  */
 
 #define DEBUG_SUBSYSTEM S_LLITE
@@ -225,21 +226,15 @@ static int vvp_page_prep_write(const struct lu_env *env,
                                const struct cl_page_slice *slice,
                                struct cl_io *unused)
 {
-        struct cl_page *cp     = slice->cpl_page;
-        cfs_page_t     *vmpage = cl2vm_page(slice);
-        int result;
+       cfs_page_t *vmpage = cl2vm_page(slice);
 
-        if (clear_page_dirty_for_io(vmpage)) {
-                set_page_writeback(vmpage);
-                vvp_write_pending(cl2ccc(slice->cpl_obj), cl2ccc_page(slice));
-                result = 0;
+       LASSERT(PageLocked(vmpage));
+       LASSERT(!PageDirty(vmpage));
 
-                /* only turn on writeback for async write. */
-                if (cp->cp_sync_io == NULL)
-                        unlock_page(vmpage);
-        } else
-                result = -EALREADY;
-        return result;
+       set_page_writeback(vmpage);
+       vvp_write_pending(cl2ccc(slice->cpl_obj), cl2ccc_page(slice));
+
+       return 0;
 }
 
 /**
@@ -342,37 +337,32 @@ static void vvp_page_completion_write(const struct lu_env *env,
  * truncated. Skip it.
  */
 static int vvp_page_make_ready(const struct lu_env *env,
-                               const struct cl_page_slice *slice)
+                              const struct cl_page_slice *slice)
 {
-        cfs_page_t *vmpage = cl2vm_page(slice);
-        struct cl_page *pg = slice->cpl_page;
-        int result;
-
-        result = -EAGAIN;
-        /* we're trying to write, but the page is locked.. come back later */
-        if (!TestSetPageLocked(vmpage)) {
-                if (pg->cp_state == CPS_CACHED) {
-                        /*
-                         * We can cancel IO if page wasn't dirty after all.
-                         */
-                        clear_page_dirty_for_io(vmpage);
-                        /*
-                         * This actually clears the dirty bit in the radix
-                         * tree.
-                         */
-                        set_page_writeback(vmpage);
-                        vvp_write_pending(cl2ccc(slice->cpl_obj),
-                                          cl2ccc_page(slice));
-                        CL_PAGE_HEADER(D_PAGE, env, pg, "readied\n");
-                        result = 0;
-                } else
-                        /*
-                         * Page was concurrently truncated.
-                         */
-                        LASSERT(pg->cp_state == CPS_FREEING);
-                unlock_page(vmpage);
-        }
-        RETURN(result);
+       cfs_page_t *vmpage = cl2vm_page(slice);
+       struct cl_page *pg = slice->cpl_page;
+       int result = 0;
+
+       lock_page(vmpage);
+       if (clear_page_dirty_for_io(vmpage)) {
+               LASSERT(pg->cp_state == CPS_CACHED);
+               /* This actually clears the dirty bit in the radix
+                * tree. */
+               set_page_writeback(vmpage);
+               vvp_write_pending(cl2ccc(slice->cpl_obj),
+                               cl2ccc_page(slice));
+               CL_PAGE_HEADER(D_PAGE, env, pg, "readied\n");
+       } else if (pg->cp_state == CPS_PAGEOUT) {
+               /* is it possible for osc_flush_async_page() to already
+                * make it ready? */
+               result = -EALREADY;
+       } else {
+               CL_PAGE_DEBUG(D_ERROR, env, pg, "Unexpecting page state %d.\n",
+                             pg->cp_state);
+               LBUG();
+       }
+       unlock_page(vmpage);
+       RETURN(result);
 }
 
 static int vvp_page_print(const struct lu_env *env,