udf: Remove BKL from free space counting functions

udf_count_free_bitmap() does not need BKL because bitmaps are in a fixed
place on disk and so we can count set bits without serialization.
udf_count_free_table() is now protected by s_alloc_mutex instead of BKL
to get a consistent view of free space extents.

Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 2 insertions, 9 deletions

diff --git a/fs/udf/super.c b/fs/udf/super.c
index 4cf6121ab41a..d2ec9f31e843 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -2207,8 +2207,6 @@ static unsigned int udf_count_free_bitmap(struct super_block *sb,
         uint16_t ident;
         struct spaceBitmapDesc *bm;
 
-        lock_kernel();
-
         loc.logicalBlockNum = bitmap->s_extPosition;
         loc.partitionReferenceNum = UDF_SB(sb)->s_partition;
         bh = udf_read_ptagged(sb, &loc, 0, &ident);
@@ -2245,10 +2243,7 @@ static unsigned int udf_count_free_bitmap(struct super_block *sb,
                 }
         }
         brelse(bh);
-
 out:
-        unlock_kernel();
-
         return accum;
 }
 
@@ -2261,8 +2256,7 @@ static unsigned int udf_count_free_table(struct super_block *sb,
         int8_t etype;
         struct extent_position epos;
 
-        lock_kernel();
-
+        mutex_lock(&UDF_SB(sb)->s_alloc_mutex);
         epos.block = UDF_I(table)->i_location;
         epos.offset = sizeof(struct unallocSpaceEntry);
         epos.bh = NULL;
@@ -2271,8 +2265,7 @@ static unsigned int udf_count_free_table(struct super_block *sb,
                 accum += (elen >> table->i_sb->s_blocksize_bits);
 
         brelse(epos.bh);
-
-        unlock_kernel();
+        mutex_unlock(&UDF_SB(sb)->s_alloc_mutex);
 
         return accum;
 }