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 3.11 November 2013 LL_RW_BLOCK(9)