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@xxxxxxxxx>
Signed-off-by: Josef Bacik <jbacik@xxxxxxxxxxxx>
---
fs/btrfs/compression.c | 12 +++++++++---
1 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 43d1c5a..36eb5f2 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;
@@ -626,8 +627,11 @@ 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;
+ }
}
cb->nr_pages = nr_pages;
@@ -713,8 +717,10 @@ 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[pg_index]);
+ faili--;
+ }
kfree(cb->compressed_pages);
fail1:
--
1.7.7.6
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