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Commit e1c4b745 authored by Chris Mason's avatar Chris Mason
Browse files

Fix btrfs_get_extent and get_block corner cases, and disable O_DIRECT reads 



The generic O_DIRECT code assumes all the bios have the same bdev,
which isn't true for multi-device btrfs.

Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 409c6118

fs/btrfs/extent_io.c

+1 −0
Original line number Diff line number Diff line
@@ -1694,6 +1694,7 @@ extent_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs, 
	}



	if (bio) {

		bio->bi_size = 0;

		bio->bi_bdev = bdev;

		bio->bi_sector = first_sector;

	}

fs/btrfs/inode.c

+21 −11
Original line number Diff line number Diff line
@@ -494,6 +494,7 @@ int btrfs_readpage_io_failed_hook(struct bio *failed_bio, 
	bio->bi_end_io = failed_bio->bi_end_io;

	bio->bi_sector = failrec->logical >> 9;

	bio->bi_bdev = failed_bio->bi_bdev;

	bio->bi_size = 0;

	bio_add_page(bio, page, failrec->len, start - page_offset(page));

	btrfs_submit_bio_hook(inode, READ, bio, failrec->last_mirror);

	return 0;
@@ -2187,12 +2188,9 @@ struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page, 
	spin_unlock(&em_tree->lock);



	if (em) {

		if (em->start > start) {

			printk("get_extent lookup [%Lu %Lu] em [%Lu %Lu]\n",

			       start, len, em->start, em->len);

			WARN_ON(1);

		}

		if (em->block_start == EXTENT_MAP_INLINE && page)

		if (em->start > start || em->start + em->len <= start)

			free_extent_map(em);

		else if (em->block_start == EXTENT_MAP_INLINE && page)

			free_extent_map(em);

		else

			goto out;
@@ -2340,7 +2338,6 @@ struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page, 
	err = 0;

	spin_lock(&em_tree->lock);

	ret = add_extent_mapping(em_tree, em);



	/* it is possible that someone inserted the extent into the tree

	 * while we had the lock dropped.  It is also possible that

	 * an overlapping map exists in the tree
@@ -2348,6 +2345,11 @@ struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page, 
	if (ret == -EEXIST) {

		struct extent_map *existing;

		existing = lookup_extent_mapping(em_tree, start, len);

		if (existing && (existing->start > start ||

		    existing->start + existing->len <= start)) {

			free_extent_map(existing);

			existing = NULL;

		}

		if (!existing) {

			existing = lookup_extent_mapping(em_tree, em->start,

							 em->len);
@@ -2388,6 +2390,7 @@ struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page, 
	return em;

}



#if 0 /* waiting for O_DIRECT reads */

static int btrfs_get_block(struct inode *inode, sector_t iblock,

			struct buffer_head *bh_result, int create)

{
@@ -2405,22 +2408,24 @@ static int btrfs_get_block(struct inode *inode, sector_t iblock, 
	if (!em || IS_ERR(em))

		goto out;



	if (em->start > start || em->start + em->len <= start)

	if (em->start > start || em->start + em->len <= start) {

	    goto out;

	}



	if (em->block_start == EXTENT_MAP_INLINE) {

		ret = -EINVAL;

		goto out;

	}



	len = em->start + em->len - start;

	len = min_t(u64, len, INT_LIMIT(typeof(bh_result->b_size)));



	if (em->block_start == EXTENT_MAP_HOLE ||

	    em->block_start == EXTENT_MAP_DELALLOC) {

		bh_result->b_size = len;

		goto out;

	}



	len = em->start + em->len - start;

	len = min_t(u64, len, INT_LIMIT(typeof(bh_result->b_size)));



	logical = start - em->start;

	logical = em->block_start + logical;
@@ -2430,6 +2435,7 @@ static int btrfs_get_block(struct inode *inode, sector_t iblock, 
	BUG_ON(ret);

	bh_result->b_blocknr = multi->stripes[0].physical >> inode->i_blkbits;

	bh_result->b_size = min(map_length, len);



	bh_result->b_bdev = multi->stripes[0].dev->bdev;

	set_buffer_mapped(bh_result);

	kfree(multi);
@@ -2437,11 +2443,14 @@ static int btrfs_get_block(struct inode *inode, sector_t iblock, 
	free_extent_map(em);

	return ret;

}

#endif



static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,

			const struct iovec *iov, loff_t offset,

			unsigned long nr_segs)

{

	return -EINVAL;

#if 0

	struct file *file = iocb->ki_filp;

	struct inode *inode = file->f_mapping->host;
@@ -2450,6 +2459,7 @@ static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb, 


	return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,

				  offset, nr_segs, btrfs_get_block, NULL);

#endif

}



static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock)

fs/btrfs/volumes.c

+1 −1
Original line number Diff line number Diff line
@@ -1161,7 +1161,6 @@ int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio, 
	int total_devs = 1;



	length = bio->bi_size;



	map_tree = &root->fs_info->mapping_tree;

	map_length = length;
@@ -1192,6 +1191,7 @@ int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio, 
		}

		bio->bi_sector = multi->stripes[dev_nr].physical >> 9;

		dev = multi->stripes[dev_nr].dev;



		bio->bi_bdev = dev->bdev;

		spin_lock(&dev->io_lock);

		dev->total_ios++;