From 15e3004a0eb2c4879bc666d0e6a3acd973fb226c Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Fri, 5 Oct 2012 13:39:50 -0400 Subject: [PATCH] Btrfs: cleanup pages properly when ENOMEM in compression MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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: Jérôme Poulin Signed-off-by: Josef Bacik --- fs/btrfs/compression.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 43d1c5a..c6467aa 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -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: -- 2.7.4