diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/backing-dev.c | 8 | ||||
| -rw-r--r-- | mm/filemap.c | 74 | ||||
| -rw-r--r-- | mm/memory-failure.c | 8 | ||||
| -rw-r--r-- | mm/nommu.c | 4 | ||||
| -rw-r--r-- | mm/page-writeback.c | 10 | ||||
| -rw-r--r-- | mm/page_io.c | 2 | ||||
| -rw-r--r-- | mm/readahead.c | 18 | ||||
| -rw-r--r-- | mm/shmem.c | 1 | ||||
| -rw-r--r-- | mm/swap_state.c | 5 | ||||
| -rw-r--r-- | mm/swapfile.c | 37 | ||||
| -rw-r--r-- | mm/vmscan.c | 2 |
11 files changed, 35 insertions, 134 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 027100d30227..8fe9d3407921 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -14,17 +14,11 @@ static atomic_long_t bdi_seq = ATOMIC_LONG_INIT(0); -void default_unplug_io_fn(struct backing_dev_info *bdi, struct page *page) -{ -} -EXPORT_SYMBOL(default_unplug_io_fn); - struct backing_dev_info default_backing_dev_info = { .name = "default", .ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_CACHE_SIZE, .state = 0, .capabilities = BDI_CAP_MAP_COPY, - .unplug_io_fn = default_unplug_io_fn, }; EXPORT_SYMBOL_GPL(default_backing_dev_info); @@ -604,7 +598,7 @@ static void bdi_prune_sb(struct backing_dev_info *bdi) spin_lock(&sb_lock); list_for_each_entry(sb, &super_blocks, s_list) { if (sb->s_bdi == bdi) - sb->s_bdi = NULL; + sb->s_bdi = &default_backing_dev_info; } spin_unlock(&sb_lock); } diff --git a/mm/filemap.c b/mm/filemap.c index f807afda86f2..04d1992fd86b 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -164,45 +164,15 @@ void delete_from_page_cache(struct page *page) } EXPORT_SYMBOL(delete_from_page_cache); -static int sync_page(void *word) +static int sleep_on_page(void *word) { - struct address_space *mapping; - struct page *page; - - page = container_of((unsigned long *)word, struct page, flags); - - /* - * page_mapping() is being called without PG_locked held. - * Some knowledge of the state and use of the page is used to - * reduce the requirements down to a memory barrier. - * The danger here is of a stale page_mapping() return value - * indicating a struct address_space different from the one it's - * associated with when it is associated with one. - * After smp_mb(), it's either the correct page_mapping() for - * the page, or an old page_mapping() and the page's own - * page_mapping() has gone NULL. - * The ->sync_page() address_space operation must tolerate - * page_mapping() going NULL. By an amazing coincidence, - * this comes about because none of the users of the page - * in the ->sync_page() methods make essential use of the - * page_mapping(), merely passing the page down to the backing - * device's unplug functions when it's non-NULL, which in turn - * ignore it for all cases but swap, where only page_private(page) is - * of interest. When page_mapping() does go NULL, the entire - * call stack gracefully ignores the page and returns. - * -- wli - */ - smp_mb(); - mapping = page_mapping(page); - if (mapping && mapping->a_ops && mapping->a_ops->sync_page) - mapping->a_ops->sync_page(page); io_schedule(); return 0; } -static int sync_page_killable(void *word) +static int sleep_on_page_killable(void *word) { - sync_page(word); + sleep_on_page(word); return fatal_signal_pending(current) ? -EINTR : 0; } @@ -558,12 +528,6 @@ struct page *__page_cache_alloc(gfp_t gfp) EXPORT_SYMBOL(__page_cache_alloc); #endif -static int __sleep_on_page_lock(void *word) -{ - io_schedule(); - return 0; -} - /* * In order to wait for pages to become available there must be * waitqueues associated with pages. By using a hash table of @@ -591,7 +555,7 @@ void wait_on_page_bit(struct page *page, int bit_nr) DEFINE_WAIT_BIT(wait, &page->flags, bit_nr); if (test_bit(bit_nr, &page->flags)) - __wait_on_bit(page_waitqueue(page), &wait, sync_page, + __wait_on_bit(page_waitqueue(page), &wait, sleep_on_page, TASK_UNINTERRUPTIBLE); } EXPORT_SYMBOL(wait_on_page_bit); @@ -655,17 +619,12 @@ EXPORT_SYMBOL(end_page_writeback); /** * __lock_page - get a lock on the page, assuming we need to sleep to get it * @page: the page to lock - * - * Ugly. Running sync_page() in state TASK_UNINTERRUPTIBLE is scary. If some - * random driver's requestfn sets TASK_RUNNING, we could busywait. However - * chances are that on the second loop, the block layer's plug list is empty, - * so sync_page() will then return in state TASK_UNINTERRUPTIBLE. */ void __lock_page(struct page *page) { DEFINE_WAIT_BIT(wait, &page->flags, PG_locked); - __wait_on_bit_lock(page_waitqueue(page), &wait, sync_page, + __wait_on_bit_lock(page_waitqueue(page), &wait, sleep_on_page, TASK_UNINTERRUPTIBLE); } EXPORT_SYMBOL(__lock_page); @@ -675,24 +634,10 @@ int __lock_page_killable(struct page *page) DEFINE_WAIT_BIT(wait, &page->flags, PG_locked); return __wait_on_bit_lock(page_waitqueue(page), &wait, - sync_page_killable, TASK_KILLABLE); + sleep_on_page_killable, TASK_KILLABLE); } EXPORT_SYMBOL_GPL(__lock_page_killable); -/** - * __lock_page_nosync - get a lock on the page, without calling sync_page() - * @page: the page to lock - * - * Variant of lock_page that does not require the caller to hold a reference - * on the page's mapping. - */ -void __lock_page_nosync(struct page *page) -{ - DEFINE_WAIT_BIT(wait, &page->flags, PG_locked); - __wait_on_bit_lock(page_waitqueue(page), &wait, __sleep_on_page_lock, - TASK_UNINTERRUPTIBLE); -} - int __lock_page_or_retry(struct page *page, struct mm_struct *mm, unsigned int flags) { @@ -1407,12 +1352,15 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov, unsigned long seg = 0; size_t count; loff_t *ppos = &iocb->ki_pos; + struct blk_plug plug; count = 0; retval = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE); if (retval) return retval; + blk_start_plug(&plug); + /* coalesce the iovecs and go direct-to-BIO for O_DIRECT */ if (filp->f_flags & O_DIRECT) { loff_t size; @@ -1485,6 +1433,7 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov, break; } out: + blk_finish_plug(&plug); return retval; } EXPORT_SYMBOL(generic_file_aio_read); @@ -2596,11 +2545,13 @@ ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, { struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; + struct blk_plug plug; ssize_t ret; BUG_ON(iocb->ki_pos != pos); mutex_lock(&inode->i_mutex); + blk_start_plug(&plug); ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos); mutex_unlock(&inode->i_mutex); @@ -2611,6 +2562,7 @@ ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, if (err < 0 && ret > 0) ret = err; } + blk_finish_plug(&plug); return ret; } EXPORT_SYMBOL(generic_file_aio_write); diff --git a/mm/memory-failure.c b/mm/memory-failure.c index e0af336530c6..37feb9fec228 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -945,7 +945,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn, collect_procs(ppage, &tokill); if (hpage != ppage) - lock_page_nosync(ppage); + lock_page(ppage); ret = try_to_unmap(ppage, ttu); if (ret != SWAP_SUCCESS) @@ -1038,7 +1038,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags) * Check "just unpoisoned", "filter hit", and * "race with other subpage." */ - lock_page_nosync(hpage); + lock_page(hpage); if (!PageHWPoison(hpage) || (hwpoison_filter(p) && TestClearPageHWPoison(p)) || (p != hpage && TestSetPageHWPoison(hpage))) { @@ -1088,7 +1088,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags) * It's very difficult to mess with pages currently under IO * and in many cases impossible, so we just avoid it here. */ - lock_page_nosync(hpage); + lock_page(hpage); /* * unpoison always clear PG_hwpoison inside page lock @@ -1231,7 +1231,7 @@ int unpoison_memory(unsigned long pfn) return 0; } - lock_page_nosync(page); + lock_page(page); /* * This test is racy because PG_hwpoison is set outside of page lock. * That's acceptable because that won't trigger kernel panic. Instead, diff --git a/mm/nommu.c b/mm/nommu.c index e629143f9440..cb86e7d5e7f5 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -1842,10 +1842,6 @@ int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, } EXPORT_SYMBOL(remap_vmalloc_range); -void swap_unplug_io_fn(struct backing_dev_info *bdi, struct page *page) -{ -} - unsigned long arch_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags) { diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 632b46479c94..31f698862420 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1040,11 +1040,17 @@ static int __writepage(struct page *page, struct writeback_control *wbc, int generic_writepages(struct address_space *mapping, struct writeback_control *wbc) { + struct blk_plug plug; + int ret; + /* deal with chardevs and other special file */ if (!mapping->a_ops->writepage) return 0; - return write_cache_pages(mapping, wbc, __writepage, mapping); + blk_start_plug(&plug); + ret = write_cache_pages(mapping, wbc, __writepage, mapping); + blk_finish_plug(&plug); + return ret; } EXPORT_SYMBOL(generic_writepages); @@ -1251,7 +1257,7 @@ int set_page_dirty_lock(struct page *page) { int ret; - lock_page_nosync(page); + lock_page(page); ret = set_page_dirty(page); unlock_page(page); return ret; diff --git a/mm/page_io.c b/mm/page_io.c index 2dee975bf469..dc76b4d0611e 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -106,7 +106,7 @@ int swap_writepage(struct page *page, struct writeback_control *wbc) goto out; } if (wbc->sync_mode == WB_SYNC_ALL) - rw |= REQ_SYNC | REQ_UNPLUG; + rw |= REQ_SYNC; count_vm_event(PSWPOUT); set_page_writeback(page); unlock_page(page); diff --git a/mm/readahead.c b/mm/readahead.c index 77506a291a2d..2c0cc489e288 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -109,9 +109,12 @@ EXPORT_SYMBOL(read_cache_pages); static int read_pages(struct address_space *mapping, struct file *filp, struct list_head *pages, unsigned nr_pages) { + struct blk_plug plug; unsigned page_idx; int ret; + blk_start_plug(&plug); + if (mapping->a_ops->readpages) { ret = mapping->a_ops->readpages(filp, mapping, pages, nr_pages); /* Clean up the remaining pages */ @@ -129,7 +132,10 @@ static int read_pages(struct address_space *mapping, struct file *filp, page_cache_release(page); } ret = 0; + out: + blk_finish_plug(&plug); + return ret; } @@ -554,17 +560,5 @@ page_cache_async_readahead(struct address_space *mapping, /* do read-ahead */ ondemand_readahead(mapping, ra, filp, true, offset, req_size); - -#ifdef CONFIG_BLOCK - /* - * Normally the current page is !uptodate and lock_page() will be - * immediately called to implicitly unplug the device. However this - * is not always true for RAID conifgurations, where data arrives - * not strictly in their submission order. In this case we need to - * explicitly kick off the IO. - */ - if (PageUptodate(page)) - blk_run_backing_dev(mapping->backing_dev_info, NULL); -#endif } EXPORT_SYMBOL_GPL(page_cache_async_readahead); diff --git a/mm/shmem.c b/mm/shmem.c index 91ce9a1024d7..58da7c150ba6 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -224,7 +224,6 @@ static const struct vm_operations_struct shmem_vm_ops; static struct backing_dev_info shmem_backing_dev_info __read_mostly = { .ra_pages = 0, /* No readahead */ .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK | BDI_CAP_SWAP_BACKED, - .unplug_io_fn = default_unplug_io_fn, }; static LIST_HEAD(shmem_swaplist); diff --git a/mm/swap_state.c b/mm/swap_state.c index 5c8cfabbc9bc..46680461785b 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -24,12 +24,10 @@ /* * swapper_space is a fiction, retained to simplify the path through - * vmscan's shrink_page_list, to make sync_page look nicer, and to allow - * future use of radix_tree tags in the swap cache. + * vmscan's shrink_page_list. */ static const struct address_space_operations swap_aops = { .writepage = swap_writepage, - .sync_page = block_sync_page, .set_page_dirty = __set_page_dirty_nobuffers, .migratepage = migrate_page, }; @@ -37,7 +35,6 @@ static const struct address_space_operations swap_aops = { static struct backing_dev_info swap_backing_dev_info = { .name = "swap", .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK | BDI_CAP_SWAP_BACKED, - .unplug_io_fn = swap_unplug_io_fn, }; struct address_space swapper_space = { diff --git a/mm/swapfile.c b/mm/swapfile.c index 039e61677635..8c6b3ce38f09 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -95,39 +95,6 @@ __try_to_reclaim_swap(struct swap_info_struct *si, unsigned long offset) } /* - * We need this because the bdev->unplug_fn can sleep and we cannot - * hold swap_lock while calling the unplug_fn. And swap_lock - * cannot be turned into a mutex. - */ -static DECLARE_RWSEM(swap_unplug_sem); - -void swap_unplug_io_fn(struct backing_dev_info *unused_bdi, struct page *page) -{ - swp_entry_t entry; - - down_read(&swap_unplug_sem); - entry.val = page_private(page); - if (PageSwapCache(page)) { - struct block_device *bdev = swap_info[swp_type(entry)]->bdev; - struct backing_dev_info *bdi; - - /* - * If the page is removed from swapcache from under us (with a - * racy try_to_unuse/swapoff) we need an additional reference - * count to avoid reading garbage from page_private(page) above. - * If the WARN_ON triggers during a swapoff it maybe the race - * condition and it's harmless. However if it triggers without - * swapoff it signals a problem. - */ - WARN_ON(page_count(page) <= 1); - - bdi = bdev->bd_inode->i_mapping->backing_dev_info; - blk_run_backing_dev(bdi, page); - } - up_read(&swap_unplug_sem); -} - -/* * swapon tell device that all the old swap contents can be discarded, * to allow the swap device to optimize its wear-levelling. */ @@ -1662,10 +1629,6 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile) goto out_dput; } - /* wait for any unplug function to finish */ - down_write(&swap_unplug_sem); - up_write(&swap_unplug_sem); - destroy_swap_extents(p); if (p->flags & SWP_CONTINUED) free_swap_count_continuations(p); diff --git a/mm/vmscan.c b/mm/vmscan.c index 060e4c191403..f73b8657c2d0 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -358,7 +358,7 @@ static int may_write_to_queue(struct backing_dev_info *bdi, static void handle_write_error(struct address_space *mapping, struct page *page, int error) { - lock_page_nosync(page); + lock_page(page); if (page_mapping(page) == mapping) mapping_set_error(mapping, error); unlock_page(page); |