bread problem

bread problem

[Joel Fernandes]

Hi,
I'm trying to read a block from disk by block_nr using __bread before
the block has even been written to disk.
The problem in doing this is the block is cached (junk data) and
future sb_bread's return the buffer head from this cache, and not one
that represent the actual data after this data has been written to
disk.

1. block contains junk
2. bread -> cached junk
3. actual data written to disk through the address space object hosted
by some other inode
4. bread -> still returns bh with junk

Is there any way to force a read from disk while doing the second
bread, or to instruct the kernel that the block that's in the cache
has to be re-read?

Thanks,
Joel