From: NeilBrown <neilb@suse.de>
Date: Fri, 4 Mar 2011 01:47:26 +0000 (+1100)
Subject: roll: handle cluster headers larger than one page.
X-Git-Url: http://git.neil.brown.name/?a=commitdiff_plain;h=64ad960d5ccf4bb38d310c74f463e3e356921311;p=LaFS.git

roll: handle cluster headers larger than one page.

If roll-forward finds cluster headers larger than one page, it now
tries to allocate that much space and if the allocation succeeds the
roll-forward will not succeed, rather than always failing.

Signed-off-by: NeilBrown <neilb@suse.de>
---

diff --git a/io.c b/io.c
index d4380f7..d59238b 100644
--- a/io.c
+++ b/io.c
@@ -91,6 +91,28 @@ lafs_load_page(struct fs *fs, struct page *p, u64 vaddr, int blocks)
 				 p, 0) ? 0 : -EIO;
 }
 
+int
+lafs_load_pages(struct fs *fs, struct page *p, u64 vaddr, int blocks)
+{
+	/* load 1 or more pages which are consecutive in memory
+	 * from 'p'
+	 * FIXME make this async - then wait.
+	 */
+	int blocks_per_page = (PAGE_SIZE >> fs->blocksize_bits);
+	int rv = 0;
+
+	while(blocks && rv == 0) {
+		int b = blocks;
+		if (b > blocks_per_page)
+			b = blocks_per_page;
+		rv = lafs_load_page(fs, p, vaddr, b);
+		blocks -= b;
+		vaddr += blocks_per_page;
+		p++;
+	}
+	return rv;
+}
+
 static void
 bi_async_complete(struct bio *bio, int error)
 {
diff --git a/lafs.h b/lafs.h
index 7af975f..f7f0b7c 100644
--- a/lafs.h
+++ b/lafs.h
@@ -97,6 +97,7 @@ typedef u64 vaddr_t;
 int lafs_sync_page_io(struct block_device *bdev, sector_t sector, int offset,
 		      int size, struct page *page, int rw);
 int lafs_load_page(struct fs *fs, struct page *p, u64 vaddr, int blocks);
+int lafs_load_pages(struct fs *fs, struct page *p, u64 vaddr, int blocks);
 int lafs_load_page_async(struct fs *fs, struct page *p, u64 vaddr, int blocks,
 			 struct async_complete *ac);
 int __must_check lafs_load_block(struct block *b, struct bio *bio);
diff --git a/roll.c b/roll.c
index 2c561db..e558552 100644
--- a/roll.c
+++ b/roll.c
@@ -518,7 +518,7 @@ roll_one(struct fs *fs, u64 *addrp, struct page *p, struct page *pg,
 	int header_blocks;
 
 	/* we "know" buf is big enough */
-	err = lafs_load_page(fs, p, addr, max/blocksize);
+	err = lafs_load_pages(fs, p, addr, max/blocksize);
 	if (err)
 		return err;
 
@@ -628,6 +628,7 @@ static int roll_forward(struct fs *fs)
 	int dev;
 	u32 seg;
 	u32 offset;
+	int order = 0;
 
 	fs->phase = 1;
 	fs->qphase = 0;
@@ -635,7 +636,7 @@ static int roll_forward(struct fs *fs)
 	clear_bit(DelayYouth, &fs->fsstate);
 
 	first = fs->checkpointcluster;
-	p = alloc_page(GFP_KERNEL);
+	p = alloc_pages(GFP_KERNEL, order);
 	if (!p)
 		return -ENOMEM;
 
@@ -643,22 +644,27 @@ static int roll_forward(struct fs *fs)
 
 	max = ((max + blocksize - 1) / blocksize) * blocksize;
 
-	if (!err && max > PAGE_SIZE)
-		err = -EFBIG;
+	if (!err && max > PAGE_SIZE) {
+		__free_pages(p, order);
+		order = get_order(max * blocksize);
+		p = alloc_pages(order, GFP_KERNEL);
+		if (!p)
+			err = -EFBIG;
+	}
 	if (err) {
-		put_page(p);
+		__free_pages(p, order);
 		return err;
 	}
 
 	pg = alloc_page(GFP_KERNEL);
 	if (!pg) {
-		put_page(p);
+		__free_pages(p, order);
 		return -ENOMEM;
 	}
 
 	err = lafs_cluster_init(fs, 0, next, last, seq);
 	if (err) {
-		put_page(p); put_page(pg);
+		__free_pages(p, order); put_page(pg);
 		return err;
 	}
 	lafs_cluster_init(fs, 1, 0, 0, 0);
@@ -692,7 +698,7 @@ static int roll_forward(struct fs *fs)
 				lafs_update_youth(fs, dev, seg);
 		}
 	}
-	put_page(p);
+	__free_pages(p, order);
 	put_page(pg);
 
 	lafs_add_active(fs, next);