centos man page for ll_rw_block

LL_RW_BLOCK(9)							   The Linux VFS						    LL_RW_BLOCK(9)

NAME
       ll_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

DESCRIPTION
       ll_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.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014							    LL_RW_BLOCK(9)