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Hello,everyone, I have some questions about Linux
file system and block device.
First, you know for the block device there is a
blk_dev table which is indexed by the major number of the block device. The
register_blkdev() function is used to insert a new entry into this blk_dev
table. How can I access to this table in my kernel module? The reason why I want
to access to this table is I want to access some specific Block Device Driver
Descriptor so that I can access to the request queue of that block device, such
as floppy disk device. This table is a global variable?
Second, whether two kernel modules can communicate
with each other or not? For example, can my own kernel module communicate with
the floppy block device? And how? I want to intercept the read/write operations
to the floppy block device. I mean I want to hook all the read/write operations
to the floppy block device in my kernel module.
Third, I know that the kernel statically allocates
a fixed number of request descriptors to handle all the requests for block
devices. There are NR_REQUEST descriptors (usually 128) stored in the
all_requests array (This is from the book "Understanding the Linux Kernel" by
Daniel P. Bovet&Marco Cesati. P403). How can I access this all_requests
array? I need to access the request descriptor of the floppy disk
device.
Last one, about the ll_rw_block() function.
How can I intercept this function in my kernel module? Can I get the function
pointer of this function in my module?
Any idea will be appreciated.
Michael |
