hfsplus: introduce alloc_mutex

Use a new per-sb alloc_mutex instead of abusing i_mutex of the alloc_file
to protect block allocations.  This gets rid of lockdep nesting warnings
and prepares for extending the scope of alloc_mutex.

Signed-off-by: Christoph Hellwig <hch@tuxera.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/hfsplus/hfsplus_fs.h b/fs/hfsplus/hfsplus_fs.h
index dc856be3c2b0..df0a6312f0f0 100644
--- a/fs/hfsplus/hfsplus_fs.h
+++ b/fs/hfsplus/hfsplus_fs.h
@@ -116,6 +116,9 @@ struct hfsplus_sb_info {
         struct inode *hidden_dir;
         struct nls_table *nls;
 
+        /* synchronize block allocations */
+        struct mutex alloc_mutex;
+
         /* Runtime variables */
         u32 blockoffset;
         u32 sect_count;