probe::ioblock_trace.bounce — Fires whenever a buffer bounce is needed for at least one page of a block IO request.
- request queue on which this bio was queued.
- total size in bytes
- bio vector count which represents number of array element (page, offset, length) which makes up this I/O request
- offset into the bio vector array
phys_segments- number of segments in this bio after physical address coalescing is performed.
- target block device
- points to the start sector of the partition structure of the device
- i-node number of the mapped file
- binary trace for read/write request
- name of the probe point
- beginning sector for the entire bio
- points to the device object which contains the partition (when bio structure represents a partition)
- device for which a buffer bounce was needed.
- 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
- number of bytes transferred