Josef Bacik
2012-Oct-05 20:38 UTC
[PATCH] Btrfs: cleanup pages properly when ENOMEM in compression V2
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>
---
V1->V2: Actually free the page we allocate
-set faili to nrpages-1 in case we fail further down
fs/btrfs/compression.c | 13 ++++++++++---
1 files 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:
--
1.7.7.6
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs"
in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html