limit max bytes that can be read/written per pread/write syscall
limit max bytes that can be read/written per pread/write syscall

Summary:
BlockBasedTable sst file size can grow to a large size when universal
compaction is used. When index block exceeds 2G, pread seems to fail and
return truncated data and causes "trucated block" error. I tried to use
```
  #define _FILE_OFFSET_BITS 64
```
But the problem still persists. Splitting a big write/read into smaller
batches seems to solve the problem.

Test Plan:
successfully compacted a case with resulting sst file at ~90G (2.1G
index block size)

Reviewers: yhchiang, igor, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22569

lgscofield/rocksdb,bbiao/rocksdb,wat-ze-hex/rocksdb,amyvmiwei/rocksdb,amyvmiwei/rocksdb,dkorolev/rocksdb,luckywhu/rocksdb,dkorolev/rocksdb,OverlordQ/rocksdb,hobinyoon/rocksdb,RyanTech/rocksdb,sorphi/rocksdb,vashstorm/rocksdb,hobinyoon/rocksdb,bbiao/rocksdb,facebook/rocksdb,Andymic/rocksdb,kaschaeffer/rocksdb,dkorolev/rocksdb,JohnPJenkins/rocksdb,virtdb/rocksdb,skunkwerks/rocksdb,JackLian/rocksdb,wskplho/rocksdb,sorphi/rocksdb,ylong/rocksdb,alihalabyah/rocksdb,wlqGit/rocksdb,norton/rocksdb,facebook/rocksdb,alihalabyah/rocksdb,JoeWoo/rocksdb,OverlordQ/rocksdb,wenduo/rocksdb,hobinyoon/rocksdb,anagav/rocksdb,JohnPJenkins/rocksdb,alihalabyah/rocksdb,IMCG/RcoksDB,JohnPJenkins/rocksdb,ryneli/rocksdb,skunkwerks/rocksdb,temicai/rocksdb,rDSN-Projects/rocksdb.replicated,hobinyoon/rocksdb,wat-ze-hex/rocksdb,virtdb/rocksdb,JoeWoo/rocksdb,bbiao/rocksdb,amyvmiwei/rocksdb,tizzybec/rocksdb,geraldoandradee/rocksdb,tsheasha/rocksdb,kaschaeffer/rocksdb,zhangpng/rocksdb,kaschaeffer/rocksdb,geraldoandradee/rocksdb,SunguckLee/RocksDB,fengshao0907/rocksdb,vmx/rocksdb,amyvmiwei/rocksdb,makelivedotnet/rocksdb,ylong/rocksdb,JoeWoo/rocksdb,biddyweb/rocksdb,norton/rocksdb,temicai/rocksdb,dkorolev/rocksdb,lgscofield/rocksdb,ryneli/rocksdb,ylong/rocksdb,wskplho/rocksdb,lgscofield/rocksdb,anagav/rocksdb,alihalabyah/rocksdb,biddyweb/rocksdb,tizzybec/rocksdb,wskplho/rocksdb,virtdb/rocksdb,luckywhu/rocksdb,mbarbon/rocksdb,bbiao/rocksdb,facebook/rocksdb,JohnPJenkins/rocksdb,IMCG/RcoksDB,tizzybec/rocksdb,Applied-Duality/rocksdb,makelivedotnet/rocksdb,temicai/rocksdb,anagav/rocksdb,geraldoandradee/rocksdb,wat-ze-hex/rocksdb,skunkwerks/rocksdb,biddyweb/rocksdb,caijieming-baidu/rocksdb,siddhartharay007/rocksdb,wenduo/rocksdb,ylong/rocksdb,JackLian/rocksdb,luckywhu/rocksdb,caijieming-baidu/rocksdb,tsheasha/rocksdb,sorphi/rocksdb,sorphi/rocksdb,skunkwerks/rocksdb,makelivedotnet/rocksdb,geraldoandradee/rocksdb,Andymic/rocksdb,alihalabyah/rocksdb,vashstorm/rocksdb,jalexanderqed/rocksdb,fengshao0907/rocksdb,RyanTech/rocksdb,tizzybec/rocksdb,siddhartharay007/rocksdb,lgscofield/rocksdb,hobinyoon/rocksdb,jalexanderqed/rocksdb,mbarbon/rocksdb,RyanTech/rocksdb,wat-ze-hex/rocksdb,SunguckLee/RocksDB,kaschaeffer/rocksdb,JohnPJenkins/rocksdb,tsheasha/rocksdb,Applied-Duality/rocksdb,vmx/rocksdb,makelivedotnet/rocksdb,ryneli/rocksdb,Applied-Duality/rocksdb,tizzybec/rocksdb,zhangpng/rocksdb,temicai/rocksdb,virtdb/rocksdb,NickCis/rocksdb,Vaisman/rocksdb,sorphi/rocksdb,bbiao/rocksdb,biddyweb/rocksdb,flabby/rocksdb,fengshao0907/rocksdb,Applied-Duality/rocksdb,NickCis/rocksdb,zhangpng/rocksdb,ylong/rocksdb,OverlordQ/rocksdb,JackLian/rocksdb,NickCis/rocksdb,flabby/rocksdb,jalexanderqed/rocksdb,NickCis/rocksdb,siddhartharay007/rocksdb,JoeWoo/rocksdb,SunguckLee/RocksDB,caijieming-baidu/rocksdb,IMCG/RcoksDB,facebook/rocksdb,SunguckLee/RocksDB,JoeWoo/rocksdb,rDSN-Projects/rocksdb.replicated,Vaisman/rocksdb,makelivedotnet/rocksdb,Vaisman/rocksdb,tschottdorf/rocksdb,luckywhu/rocksdb,Vaisman/rocksdb,flabby/rocksdb,geraldoandradee/rocksdb,fengshao0907/rocksdb,biddyweb/rocksdb,wskplho/rocksdb,lgscofield/rocksdb,anagav/rocksdb,tsheasha/rocksdb,dkorolev/rocksdb,caijieming-baidu/rocksdb,RyanTech/rocksdb,Vaisman/rocksdb,jalexanderqed/rocksdb,RyanTech/rocksdb,alihalabyah/rocksdb,facebook/rocksdb,wskplho/rocksdb,lgscofield/rocksdb,skunkwerks/rocksdb,alihalabyah/rocksdb,flabby/rocksdb,ylong/rocksdb,wlqGit/rocksdb,NickCis/rocksdb,skunkwerks/rocksdb,vmx/rocksdb,hobinyoon/rocksdb,temicai/rocksdb,Andymic/rocksdb,Andymic/rocksdb,facebook/rocksdb,sorphi/rocksdb,IMCG/RcoksDB,bbiao/rocksdb,RyanTech/rocksdb,wlqGit/rocksdb,wskplho/rocksdb,norton/rocksdb,virtdb/rocksdb,tsheasha/rocksdb,rDSN-Projects/rocksdb.replicated,tschottdorf/rocksdb,flabby/rocksdb,vmx/rocksdb,Applied-Duality/rocksdb,JackLian/rocksdb,geraldoandradee/rocksdb,zhangpng/rocksdb,biddyweb/rocksdb,vashstorm/rocksdb,amyvmiwei/rocksdb,mbarbon/rocksdb,vmx/rocksdb,fengshao0907/rocksdb,norton/rocksdb,caijieming-baidu/rocksdb,JohnPJenkins/rocksdb,wat-ze-hex/rocksdb,tschottdorf/rocksdb,siddhartharay007/rocksdb,vashstorm/rocksdb,ryneli/rocksdb,ryneli/rocksdb,tsheasha/rocksdb,Andymic/rocksdb,jalexanderqed/rocksdb,virtdb/rocksdb,OverlordQ/rocksdb,Applied-Duality/rocksdb,wenduo/rocksdb,luckywhu/rocksdb,wlqGit/rocksdb,jalexanderqed/rocksdb,ryneli/rocksdb,Vaisman/rocksdb,skunkwerks/rocksdb,dkorolev/rocksdb,kaschaeffer/rocksdb,ylong/rocksdb,rDSN-Projects/rocksdb.replicated,Applied-Duality/rocksdb,vmx/rocksdb,SunguckLee/RocksDB,siddhartharay007/rocksdb,JackLian/rocksdb,JackLian/rocksdb,tschottdorf/rocksdb,zhangpng/rocksdb,wenduo/rocksdb,wat-ze-hex/rocksdb,mbarbon/rocksdb,vashstorm/rocksdb,fengshao0907/rocksdb,facebook/rocksdb,vmx/rocksdb,dkorolev/rocksdb,SunguckLee/RocksDB,jalexanderqed/rocksdb,siddhartharay007/rocksdb,wenduo/rocksdb,amyvmiwei/rocksdb,makelivedotnet/rocksdb,IMCG/RcoksDB,mbarbon/rocksdb,tsheasha/rocksdb,NickCis/rocksdb,wenduo/rocksdb,RyanTech/rocksdb,tschottdorf/rocksdb,biddyweb/rocksdb,fengshao0907/rocksdb,zhangpng/rocksdb,flabby/rocksdb,anagav/rocksdb,hobinyoon/rocksdb,sorphi/rocksdb,IMCG/RcoksDB,mbarbon/rocksdb,rDSN-Projects/rocksdb.replicated,ryneli/rocksdb,flabby/rocksdb,kaschaeffer/rocksdb,caijieming-baidu/rocksdb,norton/rocksdb,IMCG/RcoksDB,Andymic/rocksdb,anagav/rocksdb,JoeWoo/rocksdb,temicai/rocksdb,norton/rocksdb,luckywhu/rocksdb,temicai/rocksdb,virtdb/rocksdb,vashstorm/rocksdb,tschottdorf/rocksdb,rDSN-Projects/rocksdb.replicated,norton/rocksdb,hobinyoon/rocksdb,JoeWoo/rocksdb,wlqGit/rocksdb,wskplho/rocksdb,bbiao/rocksdb,wenduo/rocksdb,caijieming-baidu/rocksdb,facebook/rocksdb,anagav/rocksdb,OverlordQ/rocksdb,bbiao/rocksdb,kaschaeffer/rocksdb,lgscofield/rocksdb,JohnPJenkins/rocksdb,wlqGit/rocksdb,Andymic/rocksdb,vmx/rocksdb,amyvmiwei/rocksdb,wlqGit/rocksdb,wat-ze-hex/rocksdb,OverlordQ/rocksdb,tizzybec/rocksdb,OverlordQ/rocksdb,JackLian/rocksdb,siddhartharay007/rocksdb,vashstorm/rocksdb,geraldoandradee/rocksdb,tizzybec/rocksdb,mbarbon/rocksdb,wenduo/rocksdb,SunguckLee/RocksDB,luckywhu/rocksdb,Vaisman/rocksdb,rDSN-Projects/rocksdb.replicated,SunguckLee/RocksDB,norton/rocksdb,tsheasha/rocksdb,Andymic/rocksdb,zhangpng/rocksdb,NickCis/rocksdb,makelivedotnet/rocksdb,wat-ze-hex/rocksdb