LL_RW_BLOCK(9) The Linux VFS LL_RW_BLOCK(9)NAMEll_rw_block - level access to block devices (DEPRECATED)
SYNOPSIS
void ll_rw_block(int rw, int nr, struct buffer_head * bhs[]);
ARGUMENTS
rw
whether to READ or WRITE or maybe READA (readahead)
nr
number of struct buffer_heads in the array
bhs[]
array of pointers to struct buffer_head
DESCRIPTIONll_rw_block takes an array of pointers to struct buffer_heads, and
requests an I/O operation on them, either a READ or a WRITE. The third
READA option is described in the documentation for generic_make_request
which ll_rw_block calls.
This function drops any buffer that it cannot get a lock on (with the
BH_Lock state bit), any buffer that appears to be clean when doing a
write request, and any buffer that appears to be up-to-date when doing
read request. Further it marks as clean buffers that are processed for
writing (the buffer cache won´t assume that they are actually clean
until the buffer gets unlocked).
ll_rw_block sets b_end_io to simple completion handler that marks the
buffer up-to-date (if approriate), unlocks the buffer and wakes any
waiters.
All of the buffers must be for the same device, and must also be a
multiple of the current approved size for the device.
COPYRIGHTKernel Hackers Manual 2.6. November 2013 LL_RW_BLOCK(9)
