On Wed, Jan 7, 2009 at 12:17 PM, Sandeep K Sinha <sandeepksinha@xxxxxxxxx> wrote: > Ok, Let me rephrase what rohit is exactly trying to question. > > There is an inode X which has say some N number of data blocks. > Now, through his own kernel module and some changes to the file system, > he wants to create a new inode Y in the FS and physically copy all the > data from the old inode to the new inode. Errr....... I must be missing something...... For this why do you need to copy the data blocks ? if you just copy the old inode to new inode, you have already copied the direct and indirect block pointers right ? That will not take much time, and now if you free the old inode, you have virtually changed the ownership of old blocks to the new inode. The problems i can see with this approach is that if the new inode is not in the same block group as old inode, you have *kind of broken* the ext2's intelligence of allocating the blocks in the same block group. CMIIW . btw this thread is interesting :-) Thanks - Manish. > > And release the old inode and its data blocks and update the dentry > with the new inode number. > PS: The file system remains completely frozen in this time. > > > On Wed, Jan 7, 2009 at 4:02 AM, Om <om.turyx@xxxxxxxxx> wrote: >> Erik Mouw wrote: >>> >>> On Tue, 6 Jan 2009 23:16:14 +0530 "Rohit Sharma" <imreckless@xxxxxxxxx> >>> wrote: >>>> >>>> On Tue, Jan 6, 2009 at 11:09 PM, Manish Katiyar <mkatiyar@xxxxxxxxx> >>>> wrote: >>>>> >>>>> Apart from performance, is there anything else you are worried >>>>> about ? >>>> >>>> Performance is only a bottleneck, >>>> this can be done in user land >>>> but kernel space solution will be more efficient. >>> >>> Hardly more efficient. Your main bottleneck will be IO from/to the >>> device. If you are worried about copying between kernel and userland, >>> you could use the tee(2) and splice(2) system calls. They are relatively >>> new, so your system might not yet have manual pages for them. In that >>> case, see http://linux.die.net/man/2/tee and >>> http://linux.die.net/man/2/splice . >> >> Hm.. that is pretty enlightening... >> Thanks, >> Om. >> >> >> -- >> To unsubscribe from this list: send an email with >> "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx >> Please read the FAQ at http://kernelnewbies.org/FAQ >> >> > > > > -- > Regards, > Sandeep. > > > > > > > "To learn is to change. Education is a process that changes the learner." > > -- > To unsubscribe from this list: send an email with > "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx > Please read the FAQ at http://kernelnewbies.org/FAQ > > -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
