Kent Overstreet, mlembi wa BCache SSD block device caching system, yomwe ili gawo la Linux kernel, anafotokoza mwachidule zotsatira za ntchito yopititsa patsogolo mafayilo a Bcachefs m'mawu ake pamsonkhano wa LSFMM 2023 (Linux Storage, Filesystem, Memory Management & BPF Summit). m'gulu lalikulu la Linux kernel ndipo adalankhula za mapulani opititsa patsogolo FS iyi. M'mwezi wa Meyi, zigamba zosinthidwa zokhala ndi kukhazikitsidwa kwa Bcachefs FS zidaperekedwa kuti ziwunikenso ndikuphatikizidwa m'gulu lalikulu la Linux kernel. FS Bcachefs yakhala ikukula kwa zaka pafupifupi 10. Kukonzekera kuwunikanso kukhazikitsidwa kwa ma Bcachefs asanaphatikizidwe pachimake kudalengezedwa kumapeto kwa 2020, ndipo mawonekedwe apano a zigamba amaganiziranso ndemanga ndi zofooka zomwe zidadziwika pakuwunika koyambirira.
Cholinga chachitukuko cha Bcachefs ndikufikira mulingo wa XFS pakuchita, kudalirika komanso kusanja, pomwe tikupereka zina zowonjezera mu Btrfs ndi ZFS, monga kuphatikiza zida zingapo pagawo, masanjidwe osungira masanjidwe angapo, kubwereza (RAID 1/10), caching, transparent data compression (LZ4, gzip ndi ZSTD modes), magawo a boma (snapshots), kutsimikizira umphumphu ndi ma checksums, kukwanitsa kusunga zizindikiro zolakwika za Reed-Solomon (RAID 5/6), kusungidwa kwachinsinsi (ChaCha20 ndi Poly1305 amagwiritsidwa ntchito). Pankhani ya magwiridwe antchito, ma Bcachefs ali patsogolo pa Btrfs ndi mafayilo ena otengera makina a Copy-on-Write, ndipo amawonetsa magwiridwe antchito pafupi ndi Ext4 ndi XFS.
Pazopambana zaposachedwa pakupanga ma Bcachefs, kukhazikika kwa kukhazikitsidwa kwa zithunzithunzi zomwe zilipo polemba zimadziwika. Poyerekeza ndi ma Btrfs, zithunzithunzi mu Bcachefs tsopano ndi zowongoka bwino komanso zopanda mavuto omwe amapezeka mu Btrfs. M'malo mwake, ntchito yazithunzi idayesedwa pokonzekera zosunga zobwezeretsera za MySQL. Ma Bcachefs adachitanso ntchito zambiri kuti apititse patsogolo scalability - mawonekedwe a fayilo achita bwino poyesa mu 100 TB yosungirako, ndipo Bcachefs ikuyembekezeka kukhazikitsidwa mu 1 PB yosungirako posachedwapa. Njira yatsopano ya nocow yawonjezedwa kuti muyimitse makina a "copy-on-write" (nocow). M'nyengo yachilimwe, akukonzekera kubweretsa kukhazikitsidwa kwa ma code okonza zolakwika ndi RAIDZ kuti ikhale yokhazikika, komanso kuthetsa mavuto ogwiritsira ntchito kukumbukira kwambiri pobwezeretsa ndi kuyang'ana machitidwe a mafayilo ndi fsck utility.
Pazokonzekera zam'tsogolo, chikhumbo chogwiritsa ntchito chilankhulo cha dzimbiri pakupanga ma Bcachef chimatchulidwa. Malinga ndi mlembi wa Bcachefs, amakonda kulemba, osati kusokoneza code, ndipo tsopano ndizopenga kulemba kachidindo mu C pamene pali njira yabwinoko. Dzimbiri ili kale mu Bcachefs pakukhazikitsa zina mwazogwiritsa ntchito malo. Komanso, lingaliro likuphwanyidwa kuti pang'onopang'ono lilembenso Bcachefs mu dzimbiri, popeza kugwiritsa ntchito chinenerochi kumapulumutsa nthawi yowonongeka.
Ponena za kusuntha ma Bcachef mumtundu waukulu wa Linux kernel, njira yotengera kulera ikhoza kuchedwa chifukwa cha kukula kwakukulu kwa zosintha (2500 zigamba ndi pafupifupi 90 zikwi mizere ya code), zomwe zimakhala zovuta kuziwona. Kuti mufulumizitse kubwereza, okonza ena apereka lingaliro la kugawa zigambazo kukhala magawo ang'onoang'ono komanso olekanitsidwa bwino. Pakukambilana, anthu ena adawonetsanso za chitukuko cha polojekitiyo ndi womanga m'modzi komanso kuopsa koti code ingasiyidwe ngati china chake chachitika kwa wopanga (ogwira ntchito awiri a Red Hat ali ndi chidwi ndi ntchitoyi, koma ntchito yawo ikadalipobe. kukonza zolakwika zochepa).
Bcachefs amapangidwa pogwiritsa ntchito matekinoloje omwe ayesedwa kale pakupanga chida cha Bcache block, chopangidwa kuti chizitha kupeza ma hard drive ocheperako pama SSD othamanga (ophatikizidwa mu kernel kuyambira kutulutsidwa kwa 3.10). Bcachefs amagwiritsa ntchito makina a Copy-on-Write (COW), momwe kusintha sikumayambitsa kubwereza deta - dziko latsopano limalembedwa ku malo atsopano, pambuyo pake chizindikiro cha boma chikusintha.
Mbali ya Bcachefs ndikuthandizira kugwirizana kwamagulu osiyanasiyana, momwe kusungirako kumapangidwa ndi zigawo zingapo - zoyendetsa zothamanga kwambiri (SSDs) zimagwirizanitsidwa ndi pansi, zomwe zimagwiritsidwa ntchito posungira deta yomwe imagwiritsidwa ntchito kawirikawiri, ndi mawonekedwe apamwamba. ma disks amphamvu kwambiri komanso otsika mtengo omwe amasunga zinthu zomwe sizikufunika kwambiri . Writeback caching angagwiritsidwe ntchito pakati pa zigawo. Ma drive amatha kuwonjezeredwa ndikuchotsedwa pagawo popanda kusokoneza kugwiritsa ntchito fayilo (data imasuntha yokha).
Source: opennet.ru