X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=mm%2Ftruncate.c;h=cadc15653ddeeaa311c80f794b6a564ae2f36fc8;hb=77f111929d024165e736e919187cff017279bebe;hp=89a5c359b6e821ec00e0fd8e8d189f3d9152e45a;hpb=3e67c0987d7567ad666641164a153dca9a43b11d;p=safe%2Fjmp%2Flinux-2.6 diff --git a/mm/truncate.c b/mm/truncate.c index 89a5c35..cadc156 100644 --- a/mm/truncate.c +++ b/mm/truncate.c @@ -8,10 +8,12 @@ */ #include +#include #include #include #include #include +#include #include #include #include /* grr. try_to_release_page, @@ -46,34 +48,48 @@ void do_invalidatepage(struct page *page, unsigned long offset) static inline void truncate_partial_page(struct page *page, unsigned partial) { - memclear_highpage_flush(page, partial, PAGE_CACHE_SIZE-partial); + zero_user_page(page, partial, PAGE_CACHE_SIZE - partial, KM_USER0); if (PagePrivate(page)) do_invalidatepage(page, partial); } +/* + * This cancels just the dirty bit on the kernel page itself, it + * does NOT actually remove dirty bits on any mmap's that may be + * around. It also leaves the page tagged dirty, so any sync + * activity will still find it on the dirty lists, and in particular, + * clear_page_dirty_for_io() will still look at the dirty bits in + * the VM. + * + * Doing this should *normally* only ever be done when a page + * is truncated, and is not actually mapped anywhere at all. However, + * fs/buffer.c does this when it notices that somebody has cleaned + * out all the buffers on a page without actually doing it through + * the VM. Can you say "ext3 is horribly ugly"? Tought you could. + */ void cancel_dirty_page(struct page *page, unsigned int account_size) { - /* If we're cancelling the page, it had better not be mapped any more */ - if (page_mapped(page)) { - static unsigned int warncount; - - WARN_ON(++warncount < 5); - } - - if (TestClearPageDirty(page) && account_size) { - dec_zone_page_state(page, NR_FILE_DIRTY); - task_io_account_cancelled_write(account_size); + if (TestClearPageDirty(page)) { + struct address_space *mapping = page->mapping; + if (mapping && mapping_cap_account_dirty(mapping)) { + dec_zone_page_state(page, NR_FILE_DIRTY); + dec_bdi_stat(mapping->backing_dev_info, + BDI_RECLAIMABLE); + if (account_size) + task_io_account_cancelled_write(account_size); + } } } +EXPORT_SYMBOL(cancel_dirty_page); /* * If truncate cannot remove the fs-private metadata from the page, the page * becomes anonymous. It will be left on the LRU and may even be mapped into - * user pagetables if we're racing with filemap_nopage(). + * user pagetables if we're racing with filemap_fault(). * * We need to bale out if page->mapping is no longer equal to the original * mapping. This happens a) when the VM reclaimed the page while we waited on - * its lock, b) when a concurrent invalidate_inode_pages got there first and + * its lock, b) when a concurrent invalidate_mapping_pages got there first and * c) when tmpfs swizzles a page between a tmpfs inode and swapper_space. */ static void @@ -87,14 +103,14 @@ truncate_complete_page(struct address_space *mapping, struct page *page) if (PagePrivate(page)) do_invalidatepage(page, 0); + remove_from_page_cache(page); ClearPageUptodate(page); ClearPageMappedToDisk(page); - remove_from_page_cache(page); page_cache_release(page); /* pagecache ref */ } /* - * This is for invalidate_inode_pages(). That function can be called at + * This is for invalidate_mapping_pages(). That function can be called at * any time, and is not supposed to throw away dirty pages. But pages can * be marked dirty at any time too, so use remove_mapping which safely * discards clean, unused pages. @@ -179,6 +195,11 @@ void truncate_inode_pages_range(struct address_space *mapping, unlock_page(page); continue; } + if (page_mapped(page)) { + unmap_mapping_range(mapping, + (loff_t)page_index<index<index > next) next = page->index; next++; @@ -240,21 +266,8 @@ void truncate_inode_pages(struct address_space *mapping, loff_t lstart) } EXPORT_SYMBOL(truncate_inode_pages); -/** - * invalidate_mapping_pages - Invalidate all the unlocked pages of one inode - * @mapping: the address_space which holds the pages to invalidate - * @start: the offset 'from' which to invalidate - * @end: the offset 'to' which to invalidate (inclusive) - * - * This function only removes the unlocked pages, if you want to - * remove all the pages of one inode, you must call truncate_inode_pages. - * - * invalidate_mapping_pages() will not block on IO activity. It will not - * invalidate pages which are dirty, locked, under writeback or mapped into - * pagetables. - */ -unsigned long invalidate_mapping_pages(struct address_space *mapping, - pgoff_t start, pgoff_t end) +unsigned long __invalidate_mapping_pages(struct address_space *mapping, + pgoff_t start, pgoff_t end, bool be_atomic) { struct pagevec pvec; pgoff_t next = start; @@ -295,22 +308,38 @@ unlock: break; } pagevec_release(&pvec); + if (likely(!be_atomic)) + cond_resched(); } return ret; } -unsigned long invalidate_inode_pages(struct address_space *mapping) +/** + * invalidate_mapping_pages - Invalidate all the unlocked pages of one inode + * @mapping: the address_space which holds the pages to invalidate + * @start: the offset 'from' which to invalidate + * @end: the offset 'to' which to invalidate (inclusive) + * + * This function only removes the unlocked pages, if you want to + * remove all the pages of one inode, you must call truncate_inode_pages. + * + * invalidate_mapping_pages() will not block on IO activity. It will not + * invalidate pages which are dirty, locked, under writeback or mapped into + * pagetables. + */ +unsigned long invalidate_mapping_pages(struct address_space *mapping, + pgoff_t start, pgoff_t end) { - return invalidate_mapping_pages(mapping, 0, ~0UL); + return __invalidate_mapping_pages(mapping, start, end, false); } -EXPORT_SYMBOL(invalidate_inode_pages); +EXPORT_SYMBOL(invalidate_mapping_pages); /* * This is like invalidate_complete_page(), except it ignores the page's * refcount. We do this because invalidate_inode_pages2() needs stronger * invalidation guarantees, and cannot afford to leave pages behind because - * shrink_list() has a temp ref on them, or because they're transiently sitting - * in the lru_cache_add() pagevecs. + * shrink_page_list() has a temp ref on them, or because they're transiently + * sitting in the lru_cache_add() pagevecs. */ static int invalidate_complete_page2(struct address_space *mapping, struct page *page) @@ -336,6 +365,15 @@ failed: return 0; } +static int do_launder_page(struct address_space *mapping, struct page *page) +{ + if (!PageDirty(page)) + return 0; + if (page->mapping != mapping || mapping->a_ops->launder_page == NULL) + return 0; + return mapping->a_ops->launder_page(page); +} + /** * invalidate_inode_pages2_range - remove range of pages from an address_space * @mapping: the address_space @@ -359,10 +397,10 @@ int invalidate_inode_pages2_range(struct address_space *mapping, pagevec_init(&pvec, 0); next = start; - while (next <= end && !ret && !wrapped && + while (next <= end && !wrapped && pagevec_lookup(&pvec, mapping, next, min(end - next, (pgoff_t)PAGEVEC_SIZE - 1) + 1)) { - for (i = 0; !ret && i < pagevec_count(&pvec); i++) { + for (i = 0; i < pagevec_count(&pvec); i++) { struct page *page = pvec.pages[i]; pgoff_t page_index; @@ -380,7 +418,7 @@ int invalidate_inode_pages2_range(struct address_space *mapping, break; } wait_on_page_writeback(page); - while (page_mapped(page)) { + if (page_mapped(page)) { if (!did_range_unmap) { /* * Zap the rest of the file in one hit. @@ -400,14 +438,15 @@ int invalidate_inode_pages2_range(struct address_space *mapping, PAGE_CACHE_SIZE, 0); } } - if (!invalidate_complete_page2(mapping, page)) + BUG_ON(page_mapped(page)); + ret = do_launder_page(mapping, page); + if (ret == 0 && !invalidate_complete_page2(mapping, page)) ret = -EIO; unlock_page(page); } pagevec_release(&pvec); cond_resched(); } - WARN_ON_ONCE(ret); return ret; } EXPORT_SYMBOL_GPL(invalidate_inode_pages2_range);