Hello All, Is it possible to mmap on a block device? I am writing my own kernel space filesystem on Linux (academic project). I am writing a user space tool to format the block device (again my own ramdisk driver). It would be much simpler if I could just mmap the block device into my address space. -Kaustubh
yes its fairly possible, go ahead and try it. On Tue, Jun 7, 2011 at 9:57 AM, Kaustubh Ashtekar <ksashtekar@gmail.com> wrote:
Hello All, Is it possible to mmap on a block device? I am writing my own kernel space filesystem on Linux (academic project). I am writing a user space tool to format the block device (again my own ramdisk driver). It would be much simpler if I could just mmap the block device into my address space. -Kaustubh _______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Done. mmap was successful. Is it a good idea to mmap a block device. A block device being much bigger than the available virtual address space, I will have to map it multiple times while working on various parts of the block device. BR, Kaustubh On Tue, Jun 7, 2011 at 11:47 AM, Rajat Sharma <fs.rajat@gmail.com> wrote:
yes its fairly possible, go ahead and try it.
On Tue, Jun 7, 2011 at 9:57 AM, Kaustubh Ashtekar <ksashtekar@gmail.com> wrote:
Hello All, Is it possible to mmap on a block device? I am writing my own kernel space filesystem on Linux (academic project). I am writing a user space tool to format the block device (again my own ramdisk driver). It would be much simpler if I could just mmap the block device into my address space. -Kaustubh _______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Hi Kaustubh, Replying to all this time... On Mon, Jun 6, 2011 at 11:44 PM, Kaustubh Ashtekar <ksashtekar@gmail.com> wrote:
Done. mmap was successful. Is it a good idea to mmap a block device. A block device being much bigger than the available virtual address space, I will have to map it multiple times while working on various parts of the block device.
What it means to mmap any device is quite arbitrary and entirely up to the driver writer. All that mmaping means is to take some memory that the driver allocated in kernel space and make that memory available into user space. The contents of the memory is entirely up to the driver. Maybe you put statistics in there? Maybe you make it map in the data storage your block device is front-ending? It's up to the driver writer to decide what goes there and whether it makes sense or not. -- Dave Hylands Shuswap, BC, Canada http://www.davehylands.com
participants (3)
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Dave Hylands -
Kaustubh Ashtekar -
Rajat Sharma