pnfs-obj: Better IO pattern in case of unaligned offset

[linux-2.6-block.git] / fs / nfs / objlayout / objio_osd.c

diff --git a/fs/nfs/objlayout/objio_osd.c b/fs/nfs/objlayout/objio_osd.c
index b47277baebab92930bee6c1fbac445fd8978a6b9..ea6d111b03e9484c23d5ca3f7997f10d893a57ad 100644 (file)
--- a/fs/nfs/objlayout/objio_osd.c
+++ b/fs/nfs/objlayout/objio_osd.c
@@ -454,7 +454,10 @@ int objio_read_pagelist(struct nfs_read_data *rdata)
        objios->ios->done = _read_done;
        dprintk("%s: offset=0x%llx length=0x%x\n", __func__,
                rdata->args.offset, rdata->args.count);
-       return ore_read(objios->ios);
+       ret = ore_read(objios->ios);
+       if (unlikely(ret))
+               objio_free_result(&objios->oir);
+       return ret;
 }
 
 /*
@@ -486,8 +489,16 @@ static struct page *__r4w_get_page(void *priv, u64 offset, bool *uptodate)
        struct nfs_write_data *wdata = objios->oir.rpcdata;
        struct address_space *mapping = wdata->header->inode->i_mapping;
        pgoff_t index = offset / PAGE_SIZE;
-       struct page *page = find_get_page(mapping, index);
+       struct page *page;
+       loff_t i_size = i_size_read(wdata->header->inode);
 
+       if (offset >= i_size) {
+               *uptodate = true;
+               dprintk("%s: g_zero_page index=0x%lx\n", __func__, index);
+               return ZERO_PAGE(0);
+       }
+
+       page = find_get_page(mapping, index);
        if (!page) {
                page = find_or_create_page(mapping, index, GFP_NOFS);
                if (unlikely(!page)) {
@@ -507,8 +518,10 @@ static struct page *__r4w_get_page(void *priv, u64 offset, bool *uptodate)
 
 static void __r4w_put_page(void *priv, struct page *page)
 {
-       dprintk("%s: index=0x%lx\n", __func__, page->index);
-       page_cache_release(page);
+       dprintk("%s: index=0x%lx\n", __func__,
+               (page == ZERO_PAGE(0)) ? -1UL : page->index);
+       if (ZERO_PAGE(0) != page)
+               page_cache_release(page);
        return;
 }
 
@@ -539,8 +552,10 @@ int objio_write_pagelist(struct nfs_write_data *wdata, int how)
        dprintk("%s: offset=0x%llx length=0x%x\n", __func__,
                wdata->args.offset, wdata->args.count);
        ret = ore_write(objios->ios);
-       if (unlikely(ret))
+       if (unlikely(ret)) {
+               objio_free_result(&objios->oir);
                return ret;
+       }
 
        if (objios->sync)
                _write_done(objios->ios, objios);
@@ -555,17 +570,66 @@ static bool objio_pg_test(struct nfs_pageio_descriptor *pgio,
                return false;
 
        return pgio->pg_count + req->wb_bytes <=
-                       OBJIO_LSEG(pgio->pg_lseg)->layout.max_io_length;
+                       (unsigned long)pgio->pg_layout_private;
+}
+
+void objio_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
+{
+       pnfs_generic_pg_init_read(pgio, req);
+       if (unlikely(pgio->pg_lseg == NULL))
+               return; /* Not pNFS */
+
+       pgio->pg_layout_private = (void *)
+                               OBJIO_LSEG(pgio->pg_lseg)->layout.max_io_length;
+}
+
+static bool aligned_on_raid_stripe(u64 offset, struct ore_layout *layout,
+                                  unsigned long *stripe_end)
+{
+       u32 stripe_off;
+       unsigned stripe_size;
+
+       if (layout->raid_algorithm == PNFS_OSD_RAID_0)
+               return true;
+
+       stripe_size = layout->stripe_unit *
+                               (layout->group_width - layout->parity);
+
+       div_u64_rem(offset, stripe_size, &stripe_off);
+       if (!stripe_off)
+               return true;
+
+       *stripe_end = stripe_size - stripe_off;
+       return false;
+}
+
+void objio_init_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
+{
+       unsigned long stripe_end = 0;
+
+       pnfs_generic_pg_init_write(pgio, req);
+       if (unlikely(pgio->pg_lseg == NULL))
+               return; /* Not pNFS */
+
+       if (req->wb_offset ||
+           !aligned_on_raid_stripe(req->wb_index * PAGE_SIZE,
+                              &OBJIO_LSEG(pgio->pg_lseg)->layout,
+                              &stripe_end)) {
+               pgio->pg_layout_private = (void *)stripe_end;
+       } else {
+               pgio->pg_layout_private = (void *)
+                               OBJIO_LSEG(pgio->pg_lseg)->layout.max_io_length;
+       }
 }
 
 static const struct nfs_pageio_ops objio_pg_read_ops = {
-       .pg_init = pnfs_generic_pg_init_read,
+       .pg_init = objio_init_read,
        .pg_test = objio_pg_test,
        .pg_doio = pnfs_generic_pg_readpages,
 };
 
 static const struct nfs_pageio_ops objio_pg_write_ops = {
-       .pg_init = pnfs_generic_pg_init_write,
+       .pg_init = objio_init_write,
        .pg_test = objio_pg_test,
        .pg_doio = pnfs_generic_pg_writepages,
 };