Hi Nitin, I did a simple test to see if b_data points to the actual data of the file/inode. I am using ext2 (non-journaling fs) for my test partition. ... Apr x 1x:50:50 x kernel: vfs_unlink: blkbits[12], blks_per_pg[1], pblock[0], lblock[26] Apr x 1x:50:50 x kernel: vfs_unlink: memset bh->b_data of block [@132130] Apr x 1x:50:50 x kernel: vfs_unlink: memset bh->b_data of block [@132131] Apr x 1x:50:50 x kernel: vfs_unlink: memset bh->b_data of block [@132132] Apr x 1x:50:50 x kernel: vfs_unlink: memset bh->b_data of block [@132133] Apr x 1x:50:50 x kernel: vfs_unlink: memset bh->b_data of block [@132134] Apr x 1x:50:50 x kernel: vfs_unlink: memset bh->b_data of block [@132135] Apr x 1x:50:50 x kernel: vfs_unlink: memset bh->b_data of block [@132136] ... Looks like I managed to get the blocks that belong to this particular inode. But when I try to zero b_data, the data still appears in the hard disk device (verified using hexdump). Any idea why? It's been troubling me for days. Regards, Kathy On Apr 5, 2005 3:26 PM, nitin ahuja <nitin2ahuja@xxxxxxxxxxxxx> wrote: > Hi, > > > > > How do I access/read the content of the files via > using inodes > > or blocks that belong to the inode, at sys_link and > vfs_link layer? > > I used bmap to access the blocks that belongs to the > inodes, but > > getting access to the buffer_head's b_data doesn't > seem to help. > > > > In struct buffer_head, b_data points to memory region of size 4K containing data of the desired block. So you can memcpy it to your buffer. > > Nitin > > -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
