blkdev_get(9) [centos man page]

BLKDEV_GET(9)							   The Linux VFS						     BLKDEV_GET(9)

NAME

       blkdev_get - open a block device

SYNOPSIS

       int blkdev_get(struct block_device * bdev, fmode_t mode, void * holder);

ARGUMENTS

       bdev
	   block_device to open

       mode
	   FMODE_* mask

       holder
	   exclusive holder identifier

DESCRIPTION

       Open bdev with mode. If mode includes FMODE_EXCL, bdev is open with exclusive access. Specifying FMODE_EXCL with NULLholder is invalid.
       Exclusive opens may nest for the same holder.

       On success, the reference count of bdev is unchanged. On failure, bdev is put.

CONTEXT

       Might sleep.

RETURNS

       0 on success, -errno on failure.

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014							     BLKDEV_GET(9)

PROBE::IOBLOCK.REQ(3stap)				  IO Scheduler and block IO Taps				 PROBE::IOBLOCK.REQ(3stap)

NAME

       probe::ioblock.request - Fires whenever making a generic block I/O request.

SYNOPSIS

       ioblock.request

VALUES

       None

DESCRIPTION

       name - name of the probe point devname - block device name ino - i-node number of the mapped file 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 make
       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 hw_segments - number of segments after physical and DMA remapping hardware 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 makes block I/O request

SystemTap Tapset Reference					     June 2014						 PROBE::IOBLOCK.REQ(3stap)