udf: Replace bkl with the UDF_I(inode)->i_data_sem for protect udf_inode_info struct

Replace bkl with the UDF_I(inode)->i_data_sem rw semaphore in
udf_release_file(), udf_symlink(), udf_symlink_filler(), udf_get_block(),
udf_block_map(), and udf_setattr(). The rule now is that any operation
on regular file's or symlink's extents (or generally allocation information
including goal block) needs to hold i_data_sem.

This work was supported by a hardware donation from the CE Linux Forum.

Signed-off-by: Alessio Igor Bogani <abogani@texware.it>
Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 10 insertions, 9 deletions

diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index fa3c154..b2fe4d7 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -301,10 +301,9 @@ static int udf_get_block(struct inode *inode, sector_t block,
 	err = -EIO;
 	new = 0;
 	bh = NULL;
-
-	lock_kernel();
-
 	iinfo = UDF_I(inode);
+
+	down_write(&iinfo->i_data_sem);
 	if (block == iinfo->i_next_alloc_block + 1) {
 		iinfo->i_next_alloc_block++;
 		iinfo->i_next_alloc_goal++;
@@ -323,7 +322,7 @@ static int udf_get_block(struct inode *inode, sector_t block,
 	map_bh(bh_result, inode->i_sb, phys);
 
 abort:
-	unlock_kernel();
+	up_write(&iinfo->i_data_sem);
 	return err;
 }
 
@@ -1021,16 +1020,16 @@ void udf_truncate(struct inode *inode)
 	if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
 		return;
 
-	lock_kernel();
 	iinfo = UDF_I(inode);
 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
+		down_write(&iinfo->i_data_sem);
 		if (inode->i_sb->s_blocksize <
 				(udf_file_entry_alloc_offset(inode) +
 				 inode->i_size)) {
 			udf_expand_file_adinicb(inode, inode->i_size, &err);
 			if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
 				inode->i_size = iinfo->i_lenAlloc;
-				unlock_kernel();
+				up_write(&iinfo->i_data_sem);
 				return;
 			} else
 				udf_truncate_extents(inode);
@@ -1041,10 +1040,13 @@ void udf_truncate(struct inode *inode)
 				offset - udf_file_entry_alloc_offset(inode));
 			iinfo->i_lenAlloc = inode->i_size;
 		}
+		up_write(&iinfo->i_data_sem);
 	} else {
 		block_truncate_page(inode->i_mapping, inode->i_size,
 				    udf_get_block);
+		down_write(&iinfo->i_data_sem);
 		udf_truncate_extents(inode);
+		up_write(&iinfo->i_data_sem);
 	}
 
 	inode->i_mtime = inode->i_ctime = current_fs_time(inode->i_sb);
@@ -1052,7 +1054,6 @@ void udf_truncate(struct inode *inode)
 		udf_sync_inode(inode);
 	else
 		mark_inode_dirty(inode);
-	unlock_kernel();
 }
 
 static void __udf_read_inode(struct inode *inode)
@@ -2043,7 +2044,7 @@ long udf_block_map(struct inode *inode, sector_t block)
 	struct extent_position epos = {};
 	int ret;
 
-	lock_kernel();
+	down_read(&UDF_I(inode)->i_data_sem);
 
 	if (inode_bmap(inode, block, &epos, &eloc, &elen, &offset) ==
 						(EXT_RECORDED_ALLOCATED >> 30))
@@ -2051,7 +2052,7 @@ long udf_block_map(struct inode *inode, sector_t block)
 	else
 		ret = 0;
 
-	unlock_kernel();
+	up_read(&UDF_I(inode)->i_data_sem);
 	brelse(epos.bh);
 
 	if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_VARCONV))