btrfs: fix uncheck memory allocation in btrfs_submit_compressed_read
btrfs_submit_compressed_read() is lack of memory allocation checks and
corresponding error route.
After this fix, if it comes to "no memory" case, errno will be returned
to userland step by step, and tell users this operation cannot go on.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index f745287..3a932f1 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -562,7 +562,7 @@
u64 em_len;
u64 em_start;
struct extent_map *em;
- int ret;
+ int ret = -ENOMEM;
u32 *sums;
tree = &BTRFS_I(inode)->io_tree;
@@ -577,6 +577,9 @@
compressed_len = em->block_len;
cb = kmalloc(compressed_bio_size(root, compressed_len), GFP_NOFS);
+ if (!cb)
+ goto out;
+
atomic_set(&cb->pending_bios, 0);
cb->errors = 0;
cb->inode = inode;
@@ -597,13 +600,18 @@
nr_pages = (compressed_len + PAGE_CACHE_SIZE - 1) /
PAGE_CACHE_SIZE;
- cb->compressed_pages = kmalloc(sizeof(struct page *) * nr_pages,
+ cb->compressed_pages = kzalloc(sizeof(struct page *) * nr_pages,
GFP_NOFS);
+ if (!cb->compressed_pages)
+ goto fail1;
+
bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
for (page_index = 0; page_index < nr_pages; page_index++) {
cb->compressed_pages[page_index] = alloc_page(GFP_NOFS |
__GFP_HIGHMEM);
+ if (!cb->compressed_pages[page_index])
+ goto fail2;
}
cb->nr_pages = nr_pages;
@@ -614,6 +622,8 @@
cb->len = uncompressed_len;
comp_bio = compressed_bio_alloc(bdev, cur_disk_byte, GFP_NOFS);
+ if (!comp_bio)
+ goto fail2;
comp_bio->bi_private = cb;
comp_bio->bi_end_io = end_compressed_bio_read;
atomic_inc(&cb->pending_bios);
@@ -681,6 +691,17 @@
bio_put(comp_bio);
return 0;
+
+fail2:
+ for (page_index = 0; page_index < nr_pages; page_index++)
+ free_page((unsigned long)cb->compressed_pages[page_index]);
+
+ kfree(cb->compressed_pages);
+fail1:
+ kfree(cb);
+out:
+ free_extent_map(em);
+ return ret;
}
static struct list_head comp_idle_workspace[BTRFS_COMPRESS_TYPES];