diff options
| author | Theodore Ts'o <tytso@mit.edu> | 2013-07-13 00:40:35 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-07-21 18:19:02 -0700 |
| commit | 6e514ac663f8d9ad5d533d9beb163b9d3142632f (patch) | |
| tree | 5c83e6fd0bfda77ae8f7fb4c59c2fb92ea6e82cd | |
| parent | 39dfe5bb5f6adba9c4a127695440fa69b2f2f361 (diff) | |
ext4: don't allow ext4_free_blocks() to fail due to ENOMEM
commit e7676a704ee0a1ef71a6b23760b5a8f6896cb1a1 upstream.
The filesystem should not be marked inconsistent if ext4_free_blocks()
is not able to allocate memory. Unfortunately some callers (most
notably ext4_truncate) don't have a way to reflect an error back up to
the VFS. And even if we did, most userspace applications won't deal
with most system calls returning ENOMEM anyway.
Reported-by: Nagachandra P <nagachandra@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/ext4/mballoc.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 19e4518b8945..878484256a6f 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4639,11 +4639,16 @@ do_more: * blocks being freed are metadata. these blocks shouldn't * be used until this transaction is committed */ + retry: new_entry = kmem_cache_alloc(ext4_free_data_cachep, GFP_NOFS); if (!new_entry) { - ext4_mb_unload_buddy(&e4b); - err = -ENOMEM; - goto error_return; + /* + * We use a retry loop because + * ext4_free_blocks() is not allowed to fail. + */ + cond_resched(); + congestion_wait(BLK_RW_ASYNC, HZ/50); + goto retry; } new_entry->efd_start_cluster = bit; new_entry->efd_group = block_group; |