{"id":506,"date":"2015-05-29T15:36:59","date_gmt":"2015-05-29T13:36:59","guid":{"rendered":"http:\/\/queen.run.montefiore.ulg.ac.be\/~barbette\/?p=506"},"modified":"2015-05-29T15:48:35","modified_gmt":"2015-05-29T13:48:35","slug":"a-linux-bug-you-can-now-understand","status":"publish","type":"post","link":"https:\/\/perso.uclouvain.be\/tom.barbette\/a-linux-bug-you-can-now-understand\/","title":{"rendered":"A Linux bug you can now understand"},"content":{"rendered":"

Hi all students from INFO0940, I came accross a bug which may ring multiple bells for you (sorry, it’s in french) :<\/p>\n

http:\/\/www.developpez.com\/actu\/85653\/Linux-decouverte-d-un-bug-sur-le-systeme-de-fichiers-EXT4-qui-pourrait-causer-une-importante-perte-de-donnees\/<\/p>\n

The bug description should remember you some all ghost :
\n\u00ab La variable “sector” dans “raid0_make_request()” n\u2019a pas \u00e9t\u00e9 correctement modifi\u00e9e par l\u2019appel \u00e0 “sector_div()” qui modifie son premier argument \u00e0 la place. Le commit [pr\u00e9c\u00e8dent] restaurait cette variable apr\u00e8s l\u2019appel pour une utilisation ult\u00e9rieure. Malheureusement la restauration a \u00e9t\u00e9 effectu\u00e9e apr\u00e8s que la variable “bio” a \u00e9t\u00e9 avanc\u00e9e \u00bb<\/p>\n

I know multiple people had problems with dividing sectors and using sector_div(). Fortunately, most of you used it correctly ! Maybe you should help them :p I wonder if the bug could happen with any file system as raid0_make_request seems to be related to MD and not to ext4 at all, maybe the article is poorely written and it was just seen with ext4 but is related to all md0 device? <\/p>\n","protected":false},"excerpt":{"rendered":"

Hi all students from INFO0940, I came accross a bug which may ring multiple bells for you (sorry, it’s in french) : http:\/\/www.developpez.com\/actu\/85653\/Linux-decouverte-d-un-bug-sur-le-systeme-de-fichiers-EXT4-qui-pourrait-causer-une-importante-perte-de-donnees\/ The bug description should remember you some all ghost : \u00ab La variable “sector” dans “raid0_make_request()” n\u2019a pas \u00e9t\u00e9 correctement modifi\u00e9e par l\u2019appel \u00e0 “sector_div()” qui modifie son premier argument \u00e0 la … <\/p>\n

Continue reading “A Linux bug you can now understand”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[69],"tags":[],"class_list":["post-506","post","type-post","status-publish","format-standard","hentry","category-os2015"],"yoast_head":"\nA Linux bug you can now understand - Tom Barbette<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/perso.uclouvain.be\/tom.barbette\/a-linux-bug-you-can-now-understand\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"A Linux bug you can now understand - Tom Barbette\" \/>\n<meta property=\"og:description\" content=\"Hi all students from INFO0940, I came accross a bug which may ring multiple bells for you (sorry, it’s in french) : http:\/\/www.developpez.com\/actu\/85653\/Linux-decouverte-d-un-bug-sur-le-systeme-de-fichiers-EXT4-qui-pourrait-causer-une-importante-perte-de-donnees\/ The bug description should remember you some all ghost : \u00ab La variable “sector” dans “raid0_make_request()” n\u2019a pas \u00e9t\u00e9 correctement modifi\u00e9e par l\u2019appel \u00e0 “sector_div()” qui modifie son premier argument \u00e0 la … Continue reading "A Linux bug you can now understand"\" \/>\n<meta property=\"og:url\" content=\"https:\/\/perso.uclouvain.be\/tom.barbette\/a-linux-bug-you-can-now-understand\/\" \/>\n<meta property=\"og:site_name\" content=\"Tom Barbette\" \/>\n<meta property=\"article:published_time\" content=\"2015-05-29T13:36:59+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2015-05-29T13:48:35+00:00\" \/>\n<meta name=\"author\" content=\"Tom Barbette\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:creator\" content=\"@TomBarbette\" \/>\n<meta name=\"twitter:site\" content=\"@TomBarbette\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Tom Barbette\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 minute\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/perso.uclouvain.be\\\/tom.barbette\\\/a-linux-bug-you-can-now-understand\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/perso.uclouvain.be\\\/tom.barbette\\\/a-linux-bug-you-can-now-understand\\\/\"},\"author\":{\"name\":\"Tom Barbette\",\"@id\":\"https:\\\/\\\/perso.uclouvain.be\\\/tom.barbette\\\/#\\\/schema\\\/person\\\/7f791766092e1207bc7a94a65e74f4fd\"},\"headline\":\"A Linux bug you can now understand\",\"datePublished\":\"2015-05-29T13:36:59+00:00\",\"dateModified\":\"2015-05-29T13:48:35+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/perso.uclouvain.be\\\/tom.barbette\\\/a-linux-bug-you-can-now-understand\\\/\"},\"wordCount\":178,\"commentCount\":0,\"publisher\":{\"@id\":\"https:\\\/\\\/perso.uclouvain.be\\\/tom.barbette\\\/#organization\"},\"articleSection\":[\"INFO-0940 Operating Systems \u2013 2014-2015 Specific posts\"],\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/perso.uclouvain.be\\\/tom.barbette\\\/a-linux-bug-you-can-now-understand\\\/\",\"url\":\"https:\\\/\\\/perso.uclouvain.be\\\/tom.barbette\\\/a-linux-bug-you-can-now-understand\\\/\",\"name\":\"A Linux bug you can now understand - 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