Commit 15e3004a authored by Josef Bacik's avatar Josef Bacik Committed by Chris Mason

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
...@@ -577,6 +577,7 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, ...@@ -577,6 +577,7 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
u64 em_start; u64 em_start;
struct extent_map *em; struct extent_map *em;
int ret = -ENOMEM; int ret = -ENOMEM;
int faili = 0;
u32 *sums; u32 *sums;
tree = &BTRFS_I(inode)->io_tree; tree = &BTRFS_I(inode)->io_tree;
...@@ -626,9 +627,13 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, ...@@ -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++) { for (pg_index = 0; pg_index < nr_pages; pg_index++) {
cb->compressed_pages[pg_index] = alloc_page(GFP_NOFS | cb->compressed_pages[pg_index] = alloc_page(GFP_NOFS |
__GFP_HIGHMEM); __GFP_HIGHMEM);
if (!cb->compressed_pages[pg_index]) if (!cb->compressed_pages[pg_index]) {
faili = pg_index - 1;
ret = -ENOMEM;
goto fail2; goto fail2;
}
} }
faili = nr_pages - 1;
cb->nr_pages = nr_pages; cb->nr_pages = nr_pages;
add_ra_bio_pages(inode, em_start + em_len, cb); 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, ...@@ -713,8 +718,10 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
return 0; return 0;
fail2: fail2:
for (pg_index = 0; pg_index < nr_pages; pg_index++) while (faili >= 0) {
free_page((unsigned long)cb->compressed_pages[pg_index]); __free_page(cb->compressed_pages[faili]);
faili--;
}
kfree(cb->compressed_pages); kfree(cb->compressed_pages);
fail1: fail1:
......
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