From 0ea971801625184a91a6d80ea85e53875caa0bf5 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Thu, 10 May 2007 22:22:51 -0700 Subject: consolidate generic_writepages and mpage_writepages Clean up massive code duplication between mpage_writepages() and generic_writepages(). The new generic function, write_cache_pages() takes a function pointer argument, which will be called for each page to be written. Maybe cifs_writepages() too can use this infrastructure, but I'm not touching that with a ten-foot pole. The upcoming page writeback support in fuse will also want this. Signed-off-by: Miklos Szeredi Acked-by: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page-writeback.c | 59 ++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 40 insertions(+), 19 deletions(-) (limited to 'mm') diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 63cd88840eb..eec1481ba44 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -588,31 +588,27 @@ void __init page_writeback_init(void) } /** - * generic_writepages - walk the list of dirty pages of the given address space and writepage() all of them. + * write_cache_pages - walk the list of dirty pages of the given address space and write all of them. * @mapping: address space structure to write * @wbc: subtract the number of written pages from *@wbc->nr_to_write + * @writepage: function called for each page + * @data: data passed to writepage function * - * 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 a page is already under I/O, write_cache_pages() 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. - * - * Derived from mpage_writepages() - if you fix this you should check that - * also! */ -int generic_writepages(struct address_space *mapping, - struct writeback_control *wbc) +int write_cache_pages(struct address_space *mapping, + struct writeback_control *wbc, writepage_t writepage, + void *data) { struct backing_dev_info *bdi = mapping->backing_dev_info; int ret = 0; int done = 0; - int (*writepage)(struct page *page, struct writeback_control *wbc); struct pagevec pvec; int nr_pages; pgoff_t index; @@ -625,12 +621,6 @@ int generic_writepages(struct address_space *mapping, return 0; } - writepage = mapping->a_ops->writepage; - - /* deal with chardevs and other special file */ - if (!writepage) - return 0; - pagevec_init(&pvec, 0); if (wbc->range_cyclic) { index = mapping->writeback_index; /* Start from prev offset */ @@ -682,8 +672,7 @@ retry: continue; } - ret = (*writepage)(page, wbc); - mapping_set_error(mapping, ret); + ret = (*writepage)(page, wbc, data); if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) unlock_page(page); @@ -710,6 +699,38 @@ retry: mapping->writeback_index = index; return ret; } +EXPORT_SYMBOL(write_cache_pages); + +/* + * Function used by generic_writepages to call the real writepage + * function and set the mapping flags on error + */ +static int __writepage(struct page *page, struct writeback_control *wbc, + void *data) +{ + struct address_space *mapping = data; + int ret = mapping->a_ops->writepage(page, wbc); + mapping_set_error(mapping, ret); + return ret; +} + +/** + * generic_writepages - walk the list of dirty pages of the given address space and writepage() all of them. + * @mapping: address space structure to write + * @wbc: subtract the number of written pages from *@wbc->nr_to_write + * + * This is a library function, which implements the writepages() + * address_space_operation. + */ +int generic_writepages(struct address_space *mapping, + struct writeback_control *wbc) +{ + /* deal with chardevs and other special file */ + if (!mapping->a_ops->writepage) + return 0; + + return write_cache_pages(mapping, wbc, __writepage, mapping); +} EXPORT_SYMBOL(generic_writepages); -- cgit v1.2.3-70-g09d2