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 fa3c1541151c..b2fe4d7f20eb 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))