On Sat, 20 Jun 2009, Ravish Tayal wrote: > Hello, > > I am debugging Filesystem code for USB mass storage devices. What part of the filesystem code are you debugging? Your questions talk about four separate layers: the filesystem, the block layer, the SCSI layer, and the usb-storage driver. Normally people work on only one layer at a time. Why are you concerned with more than one layer? > I need > help to figure out after generic_make_request how the request is > placed to scsi disk (sd) requeset queue and than how sd qeueuecommand > to usb_storeage thread. (in which context, is it system call context) > > > inside generic_make_request > > 1. q = bdev_get_queue(bio->bi_bdev); [is sd.c register queue this > queue or any other scsi file?] See scsi_alloc_sdev() in scsi_scan.c. That's where the queue is allocated. > 2. ret = q->make_request_fn(q, bio); [which file contain this > make_request_fn for scsi disk driver (generic)] scsi_request_fn() is in scsi_lib.c. You could have found this out by yourself very easily with grep. sd_prep_fn() is in sd.c. > As per my unsderanding flow is like > Fat_writepage ->_block_write_full_page --> blkdev_writepage--> > block_write_full_page-->submit_bh-->generic_make_request ??? (sd ??) > ----> queuecommand > > Please suggest any sorce file, link or document. The most relevant source files are scsi_lib.c and scsi.c. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
