btrfs: fix several uncheck memory allocations

To make btrfs more stable, add several missing necessary memory allocation
checks, and when no memory, return proper errno.

We've checked that some of those -ENOMEM errors will be returned to
userspace, and some will be catched by BUG_ON() in the upper callers,
and none will be ignored silently.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

4 files changed, 33 insertions, 0 deletions

diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c
index 6f044447359..3220ad1aafc 100644
--- a/fs/btrfs/export.c
+++ b/fs/btrfs/export.c
@@ -176,6 +176,8 @@ static struct dentry *btrfs_get_parent(struct dentry *child)
         int ret;
 
         path = btrfs_alloc_path();
+        if (!path)
+                return ERR_PTR(-ENOMEM);
 
         if (dir->i_ino == BTRFS_FIRST_FREE_OBJECTID) {
                 key.objectid = root->root_key.objectid;
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index a562a250ae7..d0bc72657cd 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -536,6 +536,8 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans,
         root = root->fs_info->csum_root;
 
         path = btrfs_alloc_path();
+        if (!path)
+                return -ENOMEM;
 
         while (1) {
                 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index f903433f5bd..65b2424a411 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -945,6 +945,10 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
                      PAGE_CACHE_SIZE, PAGE_CACHE_SIZE /
                      (sizeof(struct page *)));
         pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
+        if (!pages) {
+                ret = -ENOMEM;
+                goto out;
+        }
 
         /* generic_write_checks can change our pos */
         start_pos = pos;
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 054744ac571..c25a41d8611 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -338,6 +338,12 @@ static noinline int overwrite_item(struct btrfs_trans_handle *trans,
                 }
                 dst_copy = kmalloc(item_size, GFP_NOFS);
                 src_copy = kmalloc(item_size, GFP_NOFS);
+                if (!dst_copy || !src_copy) {
+                        btrfs_release_path(root, path);
+                        kfree(dst_copy);
+                        kfree(src_copy);
+                        return -ENOMEM;
+                }
 
                 read_extent_buffer(eb, src_copy, src_ptr, item_size);
 
@@ -665,6 +671,9 @@ static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
         btrfs_dir_item_key_to_cpu(leaf, di, &location);
         name_len = btrfs_dir_name_len(leaf, di);
         name = kmalloc(name_len, GFP_NOFS);
+        if (!name)
+                return -ENOMEM;
+
         read_extent_buffer(leaf, name, (unsigned long)(di + 1), name_len);
         btrfs_release_path(root, path);
 
@@ -744,6 +753,9 @@ static noinline int backref_in_log(struct btrfs_root *log,
         int match = 0;
 
         path = btrfs_alloc_path();
+        if (!path)
+                return -ENOMEM;
+
         ret = btrfs_search_slot(NULL, log, key, path, 0, 0);
         if (ret != 0)
                 goto out;
@@ -967,6 +979,8 @@ static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
         key.offset = (u64)-1;
 
         path = btrfs_alloc_path();
+        if (!path)
+                return -ENOMEM;
 
         while (1) {
                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
@@ -1178,6 +1192,9 @@ static noinline int replay_one_name(struct btrfs_trans_handle *trans,
 
         name_len = btrfs_dir_name_len(eb, di);
         name = kmalloc(name_len, GFP_NOFS);
+        if (!name)
+                return -ENOMEM;
+
         log_type = btrfs_dir_type(eb, di);
         read_extent_buffer(eb, name, (unsigned long)(di + 1),
                    name_len);
@@ -1692,6 +1709,8 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
                 root_owner = btrfs_header_owner(parent);
 
                 next = btrfs_find_create_tree_block(root, bytenr, blocksize);
+                if (!next)
+                        return -ENOMEM;
 
                 if (*level == 1) {
                         wc->process_func(root, next, wc, ptr_gen);
@@ -2194,6 +2213,9 @@ int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
 
         log = root->log_root;
         path = btrfs_alloc_path();
+        if (!path)
+                return -ENOMEM;
+
         di = btrfs_lookup_dir_item(trans, log, path, dir->i_ino,
                                    name, name_len, -1);
         if (IS_ERR(di)) {
@@ -2594,6 +2616,9 @@ static noinline int copy_items(struct btrfs_trans_handle *trans,
 
         ins_data = kmalloc(nr * sizeof(struct btrfs_key) +
                            nr * sizeof(u32), GFP_NOFS);
+        if (!ins_data)
+                return -ENOMEM;
+
         ins_sizes = (u32 *)ins_data;
         ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32));