bio_copy_kern(9) [centos man page]

BIO_COPY_KERN(9)						   The Linux VFS						  BIO_COPY_KERN(9)

NAME

       bio_copy_kern - copy kernel address into bio

SYNOPSIS

       struct bio * bio_copy_kern(struct request_queue * q, void * data, unsigned int len, gfp_t gfp_mask, int reading);

ARGUMENTS

       q
	   the struct request_queue for the bio

       data
	   pointer to buffer to copy

       len
	   length in bytes

       gfp_mask
	   allocation flags for bio and page allocation

       reading
	   data direction is READ

DESCRIPTION

       copy the kernel address into a bio suitable for io to a block device. Returns an error pointer in case of error.

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014							  BIO_COPY_KERN(9)

PROBE::IOBLOCK_TRACE(3stap)				  IO Scheduler and block IO Taps			       PROBE::IOBLOCK_TRACE(3stap)

NAME

       probe::ioblock_trace.bounce - Fires whenever a buffer bounce is needed for at least one page of a block IO request.

SYNOPSIS

       ioblock_trace.bounce

VALUES

       None

DESCRIPTION

       name - name of the probe point q - request queue on which this bio was queued.  devname - device for which a buffer bounce was needed.  ino
       - i-node number of the mapped file bytes_done - number of bytes transferred sector - beginning sector for the entire bio flags - see below
       BIO_UPTODATE 0 ok after I/O completion BIO_RW_BLOCK 1 RW_AHEAD set, and read/write would block BIO_EOF 2 out-out-bounds error BIO_SEG_VALID
       3 nr_hw_seg valid BIO_CLONED 4 doesn't own data BIO_BOUNCED 5 bio is a bounce bio BIO_USER_MAPPED 6 contains user pages BIO_EOPNOTSUPP 7
       not supported rw - binary trace for read/write request vcnt - bio vector count which represents number of array element (page, offset,
       length) which makes up this I/O request idx - offset into the bio vector array phys_segments - number of segments in this bio after
       physical address coalescing is performed.  size - total size in bytes bdev - target block device bdev_contains - points to the device
       object which contains the partition (when bio structure represents a partition) p_start_sect - points to the start sector of the partition
       structure of the device

CONTEXT

       The process creating a block IO request.

SystemTap Tapset Reference					     June 2014					       PROBE::IOBLOCK_TRACE(3stap)