Btrfs: fix uncheck memory allocations

To make Btrfs code more robust, several return value checks where memory
allocation can fail are introduced. I use BUG_ON where I don't know how
to handle the error properly, which increases the number of using the
notorious BUG_ON, though.

Signed-off-by: Yoshinori Sano <yoshinori.sano@gmail.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

3 files changed, 12 insertions, 0 deletions

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 4d2110eafe29..992a4b92083e 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -340,6 +340,8 @@ int btrfs_submit_compressed_write(struct inode *inode, u64 start,
 
         WARN_ON(start & ((u64)PAGE_CACHE_SIZE - 1));
         cb = kmalloc(compressed_bio_size(root, compressed_len), GFP_NOFS);
+        if (!cb)
+                return -ENOMEM;
         atomic_set(&cb->pending_bios, 0);
         cb->errors = 0;
         cb->inode = inode;
@@ -354,6 +356,10 @@ int btrfs_submit_compressed_write(struct inode *inode, u64 start,
         bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
 
         bio = compressed_bio_alloc(bdev, first_byte, GFP_NOFS);
+        if(!bio) {
+                kfree(cb);
+                return -ENOMEM;
+        }
         bio->bi_private = cb;
         bio->bi_end_io = end_compressed_bio_write;
         atomic_inc(&cb->pending_bios);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 1efeda3b2f6f..cd0b69f57375 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -6978,6 +6978,10 @@ static noinline int get_new_locations(struct inode *reloc_inode,
                         struct disk_extent *old = exts;
                         max *= 2;
                         exts = kzalloc(sizeof(*exts) * max, GFP_NOFS);
+                        if (!exts) {
+                                ret = -ENOMEM;
+                                goto out;
+                        }
                         memcpy(exts, old, sizeof(*exts) * nr);
                         if (old != *extents)
                                 kfree(old);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 67fd6e9552d3..f739b256967e 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -290,6 +290,7 @@ static noinline int add_async_extent(struct async_cow *cow,
         struct async_extent *async_extent;
 
         async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
+        BUG_ON(!async_extent);
         async_extent->start = start;
         async_extent->ram_size = ram_size;
         async_extent->compressed_size = compressed_size;
@@ -388,6 +389,7 @@ again:
              (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) {
                 WARN_ON(pages);
                 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
+                BUG_ON(!pages);
 
                 if (BTRFS_I(inode)->force_compress)
                         compress_type = BTRFS_I(inode)->force_compress;