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: Jérôme Poulin <jeromepoulin@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
This commit is contained in:
Josef Bacik 2012-10-05 13:39:50 -04:00 committed by Chris Mason
parent 5af3e8cce8
commit 15e3004a0e
1 changed files with 10 additions and 3 deletions

View File

@ -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: