device - What kernel module function gets called, when I say "cat myfile > /dev/sda" -


i've skimmed through linux kernel module programming guide, can't figure out:

when cat image.iso > /dev/sda, cause write function of file_operations structure executed sda device driver? or file interface not applied block device nodes?

where find function's implementation? (the respective driver within linux code tree)?

fs/block-dev.c defines file operations , address space operations applicable block devices. 

static const struct address_space_operations def_blk_aops = {     .readpage       = blkdev_readpage,     .writepage      = blkdev_writepage,     .write_begin    = blkdev_write_begin,     .write_end      = blkdev_write_end,     .writepages     = generic_writepages,     .releasepage    = blkdev_releasepage,     .direct_io      = blkdev_direct_io,     .is_dirty_writeback = buffer_check_dirty_writeback, };  const struct file_operations def_blk_fops = {     .open           = blkdev_open,     .release        = blkdev_close,     .llseek         = block_llseek,     .read           = do_sync_read,     .write          = do_sync_write,     .aio_read       = blkdev_aio_read,     .aio_write      = blkdev_aio_write,     .mmap           = generic_file_mmap,     .fsync          = blkdev_fsync,     .unlocked_ioctl = block_ioctl, #ifdef config_compat     .compat_ioctl   = compat_blkdev_ioctl, #endif     .splice_read    = generic_file_splice_read,     .splice_write   = generic_file_splice_write, };

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