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Commit 15e3004a authored by Josef Bacik's avatar Josef Bacik Committed by Chris Mason
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Btrfs: cleanup pages properly when ENOMEM in compression 



We were freeing non-existent pages which was causing a panic for a user who
was suffering from ENOMEM.  This patch fixes the problem.  Thanks,

Reported-by: default avatarJérôme Poulin <jeromepoulin@gmail.com>
Signed-off-by: default avatarJosef Bacik <jbacik@fusionio.com>
parent 5af3e8cc

fs/btrfs/compression.c

+10 −3
Original line number Diff line number Diff line
@@ -577,6 +577,7 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, 
	u64 em_start;

	struct extent_map *em;

	int ret = -ENOMEM;

	int faili = 0;

	u32 *sums;



	tree = &BTRFS_I(inode)->io_tree;
@@ -626,9 +627,13 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, 
	for (pg_index = 0; pg_index < nr_pages; pg_index++) {

		cb->compressed_pages[pg_index] = alloc_page(GFP_NOFS |

							      __GFP_HIGHMEM);

		if (!cb->compressed_pages[pg_index])

		if (!cb->compressed_pages[pg_index]) {

			faili = pg_index - 1;

			ret = -ENOMEM;

			goto fail2;

		}

	}

	faili = nr_pages - 1;

	cb->nr_pages = nr_pages;



	add_ra_bio_pages(inode, em_start + em_len, cb);
@@ -713,8 +718,10 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, 
	return 0;



fail2:

	for (pg_index = 0; pg_index < nr_pages; pg_index++)

		free_page((unsigned long)cb->compressed_pages[pg_index]);

	while (faili >= 0) {

		__free_page(cb->compressed_pages[faili]);

		faili--;

	}



	kfree(cb->compressed_pages);

fail1: