XFS_CLSF_2013

《XFS_CLSF_2013》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。

1、XFSUpdateforCLSF2013OverallStatusCodechanges#gitdiff--stat--minimal-C-Mv3.7..v3.12-rc4--fs/xfs141fileschanged,27598insertions(+),19113deletions(-)RoughlystatisticsofpatchesTotal:about450Improves:120+Bugfixes:100+Newfeatures:140+Misc:...NewFeatures➢UsernamespacesupportforL

2、XC–Initialsupport–EverythinginuserspacetoolswhichneedCAP_SYS_ADMINcapacitycannotbeusedinsideanon-initialuserns.e.g,xfsdump/xfsrestore➢Splitproject/groupquotainodes–I.e,usr/grp/prjquotacanbeenabledatthesametime(v5superblock)NewFeaturesCONFIG_XFS_WARNvsCONFIG_XFS_DEBUG–Mutua

3、lexclusiveforkernelconfigurationProblemsoftheexistingCONFIG_XFS_DEBUG–Introducessignificantoverhead,e.g,changethebehaviourofalgorithms(suchasallocation)toimprovetestcoverage–Evenworse,wouldpanicthemachineonnon-fatalerrorsNewFeaturesCONFIG_XFS_WARN–ConvertsASSERT()checksto

4、WARN_ON(1)–Lessoverhead(generallywithalittlebitCPUoverhead:<1%)–Candetectout-of-boundissuemoreeasier–AdvisabletoapplyinproductionenvironmentNewFeaturesSelf-describingmetadata–CRCCheck(v5SB)–Nonoticeableoverhead(0%~5%)eventwithouthardwareCRCacceleration–Thisisthelargestfeat

5、ureandleadtothebiggestcodechangeinthepastyearSEEK_DATA/SEEK_HOLEforxfs_io(8)support–AnewtestwillbeintroducedtoxfsteststhroughthisfeatureImprovementsTransactionlogspacereservation–Killthehardcodenumber128forextralogstructurespace–Calculatethetransactionreservationspaceatth

6、emounttimeratherthantheoldmodatruntime–Misc:fixtheminimaltransactionlogspaceifthesunitisspecifiedonmountImprovementsIntroduceobjectreadaheadforlogrecovery–Originallythisoperationisperformedasasinglethread,introduceobjectreadaheadcanreducethereadlatencyImprovementsSpeculat

7、ivepreallocationhistory–bufferedwriteinsameAGnearEOF–Fixedvalueviamountoption:allocsize–DynamicspeculativeEOFpreallocation(e.g,4kblocksize)FreespaceMaxpreallocsize-------------------------------------->5%fullextent(8GB)4-5%2GB(8GB>>2)3-4%1GB(8GB>>3)2-3%512MB(8GB>>4)1-2%256M

8、B(8GB>>5)<1%128MB(8GB>>6)Improvements➢Speculativepreallocationinodetracking,cleari