offset into the bio vector array phys_segments - number of segments in this bio after physical address coalescing is performed.

number of bytes transferred

target block device

bio vector count which represents number of array element (page, offset, length) which makes up this I/O request

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

name of the probe point

beginning sector for the entire bio

binary trace for read/write request

block device name

request queue on which this bio was queued.

total size in bytes

i-node number of the mapped file

operations and flags

points to the start sector of the partition structure of the device

points to the device object which contains the partition (when bio structure represents a partition)