pnfsblock: alloc short extent before submit bio

As discussed earlier, it is better for block client to allocate memory for
tracking extents state before submitting bio. So the patch does it by allocating
a short_extent for every INVALID extent touched by write pagelist and for
every zeroing page we created, saving them in layout header. Then in end_io we
can just use them to create commit list items and avoid memory allocation there.

Signed-off-by: Peng Tao <peng_tao@emc.com>
Signed-off-by: Benny Halevy <bhalevy@tonian.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 58 insertions, 16 deletions

diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
index 9215c6644a3a..48cfac31f64c 100644
--- a/fs/nfs/blocklayout/blocklayout.c
+++ b/fs/nfs/blocklayout/blocklayout.c
@@ -90,8 +90,9 @@ static int is_writable(struct pnfs_block_extent *be, sector_t isect)
  */
 struct parallel_io {
 	struct kref refcnt;
-	void (*pnfs_callback) (void *data);
+	void (*pnfs_callback) (void *data, int num_se);
 	void *data;
+	int bse_count;
 };
 
 static inline struct parallel_io *alloc_parallel(void *data)
@@ -102,6 +103,7 @@ static inline struct parallel_io *alloc_parallel(void *data)
 	if (rv) {
 		rv->data = data;
 		kref_init(&rv->refcnt);
+		rv->bse_count = 0;
 	}
 	return rv;
 }
@@ -116,7 +118,7 @@ static void destroy_parallel(struct kref *kref)
 	struct parallel_io *p = container_of(kref, struct parallel_io, refcnt);
 
 	dprintk("%s enter\n", __func__);
-	p->pnfs_callback(p->data);
+	p->pnfs_callback(p->data, p->bse_count);
 	kfree(p);
 }
 
@@ -216,7 +218,7 @@ static void bl_read_cleanup(struct work_struct *work)
 }
 
 static void
-bl_end_par_io_read(void *data)
+bl_end_par_io_read(void *data, int unused)
 {
 	struct nfs_read_data *rdata = data;
 
@@ -317,6 +319,7 @@ static void mark_extents_written(struct pnfs_block_layout *bl,
 {
 	sector_t isect, end;
 	struct pnfs_block_extent *be;
+	struct pnfs_block_short_extent *se;
 
 	dprintk("%s(%llu, %u)\n", __func__, offset, count);
 	if (count == 0)
@@ -329,8 +332,11 @@ static void mark_extents_written(struct pnfs_block_layout *bl,
 		be = bl_find_get_extent(bl, isect, NULL);
 		BUG_ON(!be); /* FIXME */
 		len = min(end, be->be_f_offset + be->be_length) - isect;
-		if (be->be_state == PNFS_BLOCK_INVALID_DATA)
-			bl_mark_for_commit(be, isect, len); /* What if fails? */
+		if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
+			se = bl_pop_one_short_extent(be->be_inval);
+			BUG_ON(!se);
+			bl_mark_for_commit(be, isect, len, se);
+		}
 		isect += len;
 		bl_put_extent(be);
 	}
@@ -352,7 +358,8 @@ static void bl_end_io_write_zero(struct bio *bio, int err)
 		end_page_writeback(page);
 		page_cache_release(page);
 	} while (bvec >= bio->bi_io_vec);
-	if (!uptodate) {
+
+	if (unlikely(!uptodate)) {
 		if (!wdata->pnfs_error)
 			wdata->pnfs_error = -EIO;
 		pnfs_set_lo_fail(wdata->lseg);
@@ -361,7 +368,6 @@ static void bl_end_io_write_zero(struct bio *bio, int err)
 	put_parallel(par);
 }
 
-/* This is basically copied from mpage_end_io_read */
 static void bl_end_io_write(struct bio *bio, int err)
 {
 	struct parallel_io *par = bio->bi_private;
@@ -387,7 +393,7 @@ static void bl_write_cleanup(struct work_struct *work)
 	dprintk("%s enter\n", __func__);
 	task = container_of(work, struct rpc_task, u.tk_work);
 	wdata = container_of(task, struct nfs_write_data, task);
-	if (!wdata->pnfs_error) {
+	if (likely(!wdata->pnfs_error)) {
 		/* Marks for LAYOUTCOMMIT */
 		mark_extents_written(BLK_LSEG2EXT(wdata->lseg),
 				     wdata->args.offset, wdata->args.count);
@@ -396,10 +402,15 @@ static void bl_write_cleanup(struct work_struct *work)
 }
 
 /* Called when last of bios associated with a bl_write_pagelist call finishes */
-static void bl_end_par_io_write(void *data)
+static void bl_end_par_io_write(void *data, int num_se)
 {
 	struct nfs_write_data *wdata = data;
 
+	if (unlikely(wdata->pnfs_error)) {
+		bl_free_short_extents(&BLK_LSEG2EXT(wdata->lseg)->bl_inval,
+					num_se);
+	}
+
 	wdata->task.tk_status = wdata->pnfs_error;
 	wdata->verf.committed = NFS_FILE_SYNC;
 	INIT_WORK(&wdata->task.u.tk_work, bl_write_cleanup);
@@ -552,7 +563,7 @@ bl_write_pagelist(struct nfs_write_data *wdata, int sync)
 	 */
 	par = alloc_parallel(wdata);
 	if (!par)
-		return PNFS_NOT_ATTEMPTED;
+		goto out_mds;
 	par->pnfs_callback = bl_end_par_io_write;
 	/* At this point, have to be more careful with error handling */
 
@@ -560,12 +571,15 @@ bl_write_pagelist(struct nfs_write_data *wdata, int sync)
 	be = bl_find_get_extent(BLK_LSEG2EXT(wdata->lseg), isect, &cow_read);
 	if (!be || !is_writable(be, isect)) {
 		dprintk("%s no matching extents!\n", __func__);
-		wdata->pnfs_error = -EINVAL;
-		goto out;
+		goto out_mds;
 	}
 
 	/* First page inside INVALID extent */
 	if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
+		if (likely(!bl_push_one_short_extent(be->be_inval)))
+			par->bse_count++;
+		else
+			goto out_mds;
 		temp = offset >> PAGE_CACHE_SHIFT;
 		npg_zero = do_div(temp, npg_per_block);
 		isect = (sector_t) (((offset - npg_zero * PAGE_CACHE_SIZE) &
@@ -603,6 +617,19 @@ fill_invalid_ext:
 				wdata->pnfs_error = ret;
 				goto out;
 			}
+			if (likely(!bl_push_one_short_extent(be->be_inval)))
+				par->bse_count++;
+			else {
+				end_page_writeback(page);
+				page_cache_release(page);
+				wdata->pnfs_error = -ENOMEM;
+				goto out;
+			}
+			/* FIXME: This should be done in bi_end_io */
+			mark_extents_written(BLK_LSEG2EXT(wdata->lseg),
+					     page->index << PAGE_CACHE_SHIFT,
+					     PAGE_CACHE_SIZE);
+
 			bio = bl_add_page_to_bio(bio, npg_zero, WRITE,
 						 isect, page, be,
 						 bl_end_io_write_zero, par);
@@ -611,10 +638,6 @@ fill_invalid_ext:
 				bio = NULL;
 				goto out;
 			}
-			/* FIXME: This should be done in bi_end_io */
-			mark_extents_written(BLK_LSEG2EXT(wdata->lseg),
-					     page->index << PAGE_CACHE_SHIFT,
-					     PAGE_CACHE_SIZE);
 next_page:
 			isect += PAGE_CACHE_SECTORS;
 			extent_length -= PAGE_CACHE_SECTORS;
@@ -638,6 +661,15 @@ next_page:
 				wdata->pnfs_error = -EINVAL;
 				goto out;
 			}
+			if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
+				if (likely(!bl_push_one_short_extent(
+								be->be_inval)))
+					par->bse_count++;
+				else {
+					wdata->pnfs_error = -ENOMEM;
+					goto out;
+				}
+			}
 			extent_length = be->be_length -
 			    (isect - be->be_f_offset);
 		}
@@ -685,6 +717,10 @@ out:
 	bl_submit_bio(WRITE, bio);
 	put_parallel(par);
 	return PNFS_ATTEMPTED;
+out_mds:
+	bl_put_extent(be);
+	kfree(par);
+	return PNFS_NOT_ATTEMPTED;
 }
 
 /* FIXME - range ignored */
@@ -711,11 +747,17 @@ static void
 release_inval_marks(struct pnfs_inval_markings *marks)
 {
 	struct pnfs_inval_tracking *pos, *temp;
+	struct pnfs_block_short_extent *se, *stemp;
 
 	list_for_each_entry_safe(pos, temp, &marks->im_tree.mtt_stub, it_link) {
 		list_del(&pos->it_link);
 		kfree(pos);
 	}
+
+	list_for_each_entry_safe(se, stemp, &marks->im_extents, bse_node) {
+		list_del(&se->bse_node);
+		kfree(se);
+	}
 	return;
 }