So if my s_blocksize = PAGE_CACHE_SIZE/2 then s_blocksize_bits will necessarily be (PAGE_CACHE_SHIFT -1) ? How will things get impacted if i still stick to s_blocksize_bits=PAGE_CACHE_SHIFT?Will I get an error or will a block span across 2 pages and hence dismal system performance? - Asim On 4/11/06, Thayumanavar Sachithanantham <thayumker@xxxxxxxxx> wrote: > > On 4/11/06, Asim <asimkadav@xxxxxxxxx> wrote: > > What is blocksize_bits variable in file system drivers ? (in > > superblock filling methods) > > > > The number of bits that make up the filesystem block size. Say if > filesystems block size is 512 bytes(s_blocksize field of struct > super_block), the s_blocksize_bits =9 (since 2^9=512). > > > > > Why is set to PAGE_CACHE_SHIFT ? > > > > Eg. > > > > s_blocksize_bits = PAGE_CACHE_SHIFT > > > > set because since s_blocksize = PAGE_CACHE_SIZE > The maximum file system block size is limited by the page cache size (which > is 4k on x86 systems). > > Thayumanavar S. -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
