centos man page for mpage_writepages

MPAGE_WRITEPAGES(9)						   The Linux VFS					       MPAGE_WRITEPAGES(9)

NAME
       mpage_writepages - walk the list of dirty pages of the given address space & writepage all of them

SYNOPSIS
       int mpage_writepages(struct address_space * mapping, struct writeback_control * wbc, get_block_t get_block);

ARGUMENTS
       mapping
	   address space structure to write

       wbc
	   subtract the number of written pages from *wbc->nr_to_write

       get_block
	   the filesystem's block mapper function. If this is NULL then use a_ops->writepage. Otherwise, go direct-to-BIO.

DESCRIPTION
       This is a library function, which implements the writepages address_space_operation.

       If a page is already under I/O, generic_writepages skips it, even if it's dirty. This is desirable behaviour for memory-cleaning writeback,
       but it is INCORRECT for data-integrity system calls such as fsync.  fsync and msync need to guarantee that all the data which was dirty at
       the time the call was made get new I/O started against them. If wbc->sync_mode is WB_SYNC_ALL then we were called for data integrity and we
       must wait for existing IO to complete.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014						       MPAGE_WRITEPAGES(9)