samaio - Pseudo Device Driver for AIO
SUNWqfsr SUNWsamfsr
The pseudo driver, samaio, allows you to attach a QFS file to a
character device, which can then be accessed through that device.
setfa -q attaches a QFS file to samaio. When you open a file
with the -q attribute set,
you use the character device.
Samaio translates access to the character device into I∕O on the
underlying QFS file. This is useful for aio because raw device I∕O is
faster than file system aio.
Samaio is controlled through \fB\∕dev∕samaioctl - this is the only
device exported during attach, and is minor number 0. QFS communicates
with samaio through ioctls on this device. When a file is attached to
samaio, character devices are exported in \fB\∕dev∕rsamaio. These
devices are identified by their minor number. Minor devices are tracked
with state structures handled with ddi_soft_state(9F).
The command ls displays a character device for files
with the -q attribute set,
The command sls displays a regular file with its current length
for files with the -q attribute set,
EACCESPermission denied.
EBUSYThe device was opened exclusively by another thread.
EFAULTThe argument was a bad address.
EINVALInvalid argument.
EIO An I∕O error occurred.
ENOTTYThis indicates that the device does not support the requested ioctl function.
ENXIODuring opening, the device did not exist.
∕dev∕samaioctl Master control device
∕dev∕rsamaio∕n Character device for file n
∕kernel∕drv∕samaio 32-bit driver
∕kernel∕drv∕samaio.conf Driver configuration file. (Should not be altered.)
∕kernel∕drv∕sparcv9∕samaio 64-bit driver
driver.conf(4),
devfsadm(1M),
setfa(1),
sam_setfa (3x)
