mpage_writepages (9) - Linux Man Pages
mpage_writepages: walk the list of dirty pages of the given address space & writepage all of them
mpage_writepages - walk the list of dirty pages of the given address space & writepage all of them
int mpage_writepages(struct address_space
*mapping, struct writeback_control *wbc, get_block_t get_block);
- address space structure to write
- subtract the number of written pages from *wbc->nr_to_write
- the filesystem's block mapper function. If this is NULL then use a_ops->writepage. Otherwise, go direct-to-BIO.
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.