Revert "fs/ntfs3: Replace inode_trylock with inode_lock"

This reverts commit 69505fe.

Initially, conditional lock acquisition was removed to fix an xfstest bug
that was observed during internal testing. The deadlock reported by syzbot
is resolved by reintroducing conditional acquisition. The xfstest bug no
longer occurs on kernel version 6.16-rc1 during internal testing. I
assume that changes in other modules may have contributed to this.

Fixes: 69505fe ("fs/ntfs3: Replace inode_trylock with inode_lock")
Reported-by: syzbot+a91fcdbd2698f99db8f4@syzkaller.appspotmail.com
Suggested-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>

Author: aalexandrovich

fs/ntfs3/file.c

@@ -322,7 +322,10 @@ static int ntfs_file_mmap(struct file *file, struct vm_area_struct *vma)
 		}
 
 		if (ni->i_valid < to) {
-			inode_lock(inode);
+			if (!inode_trylock(inode)) {
+				err = -EAGAIN;
+				goto out;
+			}
 			err = ntfs_extend_initialized_size(file, ni,
 							   ni->i_valid, to);
 			inode_unlock(inode);