linux kernel - Modifying the EXT2 Filesystem -


for project i'm working on, need able modify ext2 filesystem. have done extensive research, not commonly required task, there seems little helpful information available online. unfortunately, due confidentiality, cannot go specifics of working on, can break situation down several key problems grateful assistance on. should note have little experience linux kernel/os development.

i realise not easy problem tackle, , going big challenge seeing small part of project. assistance these problems (or other warnings/advice) appreciated.

if turns out impossible, entire project have rethought, hence why starting @ point.

problem 1: source code implementation

this not first problem, need answer first in order make sure i'm on right track @ all! remember novice, may silly question.

from can tell, ext2 source code contained within kernel source code @ linux/fs/ext2/. if modify source code make changes require, rebuild kernel, take make drive or partition use newly modified filesystem? able reformat drive ext2, using new kernel, , modified filesystem applied due modified source code? or oversimplifying this?

problem 2: extending metadata

a vital part of project requires me extend metadata each file on drive contains. in case, metadata refers details such owner, created timestamp, modified timestamp etc. able add , able update additional metadata field. think best approach modify inode, after looking through source code long time, can't see anywhere obvious start.

problem 3: consequences?

assume am successful in adding , using field on modified filesystem. if file moved drive, unmodified ext2 filesystem, data contained in metadata field lost? files moved between different filesystems time no problem, unsure how handle this. should note not required able access metadata on other system, require data not lost.

bonus question

so far i've been using centos prototype. if there advice whether good/bad/doesn't matter, appreciate it.

edit/update clarify problem

as said previously, confidentiality prevents me discussing end-game is. here basic problem, should explain more of kind of things need able do.

traditional filesystems keep track of 3 main timestamps: created, last accessed, last modified. let's wanted add new type of metadata, called "modify history", stores list of timestamps each , every modification. way can think this, add attribute point datablock, timestamps appended every time write made file/inode.

again, actual problem far more complex, gives better idea of kind of thing need able do.


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