diff options
Diffstat (limited to 'mm/backing-dev.c')
-rw-r--r-- | mm/backing-dev.c | 117 |
1 files changed, 33 insertions, 84 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 0ae0df55000b..6dc4580df2af 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -14,19 +14,10 @@ static atomic_long_t bdi_seq = ATOMIC_LONG_INIT(0); -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, -}; -EXPORT_SYMBOL_GPL(default_backing_dev_info); - struct backing_dev_info noop_backing_dev_info = { .name = "noop", .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK, }; -EXPORT_SYMBOL_GPL(noop_backing_dev_info); static struct class *bdi_class; @@ -40,17 +31,6 @@ LIST_HEAD(bdi_list); /* bdi_wq serves all asynchronous writeback tasks */ struct workqueue_struct *bdi_wq; -static void bdi_lock_two(struct bdi_writeback *wb1, struct bdi_writeback *wb2) -{ - if (wb1 < wb2) { - spin_lock(&wb1->list_lock); - spin_lock_nested(&wb2->list_lock, 1); - } else { - spin_lock(&wb2->list_lock); - spin_lock_nested(&wb1->list_lock, 1); - } -} - #ifdef CONFIG_DEBUG_FS #include <linux/debugfs.h> #include <linux/seq_file.h> @@ -69,10 +49,10 @@ static int bdi_debug_stats_show(struct seq_file *m, void *v) unsigned long background_thresh; unsigned long dirty_thresh; unsigned long bdi_thresh; - unsigned long nr_dirty, nr_io, nr_more_io; + unsigned long nr_dirty, nr_io, nr_more_io, nr_dirty_time; struct inode *inode; - nr_dirty = nr_io = nr_more_io = 0; + nr_dirty = nr_io = nr_more_io = nr_dirty_time = 0; spin_lock(&wb->list_lock); list_for_each_entry(inode, &wb->b_dirty, i_wb_list) nr_dirty++; @@ -80,6 +60,9 @@ static int bdi_debug_stats_show(struct seq_file *m, void *v) nr_io++; list_for_each_entry(inode, &wb->b_more_io, i_wb_list) nr_more_io++; + list_for_each_entry(inode, &wb->b_dirty_time, i_wb_list) + if (inode->i_state & I_DIRTY_TIME) + nr_dirty_time++; spin_unlock(&wb->list_lock); global_dirty_limits(&background_thresh, &dirty_thresh); @@ -98,6 +81,7 @@ static int bdi_debug_stats_show(struct seq_file *m, void *v) "b_dirty: %10lu\n" "b_io: %10lu\n" "b_more_io: %10lu\n" + "b_dirty_time: %10lu\n" "bdi_list: %10u\n" "state: %10lx\n", (unsigned long) K(bdi_stat(bdi, BDI_WRITEBACK)), @@ -111,6 +95,7 @@ static int bdi_debug_stats_show(struct seq_file *m, void *v) nr_dirty, nr_io, nr_more_io, + nr_dirty_time, !list_empty(&bdi->bdi_list), bdi->state); #undef K @@ -264,9 +249,6 @@ static int __init default_bdi_init(void) if (!bdi_wq) return -ENOMEM; - err = bdi_init(&default_backing_dev_info); - if (!err) - bdi_register(&default_backing_dev_info, NULL, "default"); err = bdi_init(&noop_backing_dev_info); return err; @@ -355,19 +337,19 @@ EXPORT_SYMBOL(bdi_register_dev); */ static void bdi_wb_shutdown(struct backing_dev_info *bdi) { - if (!bdi_cap_writeback_dirty(bdi)) + /* Make sure nobody queues further work */ + spin_lock_bh(&bdi->wb_lock); + if (!test_and_clear_bit(BDI_registered, &bdi->state)) { + spin_unlock_bh(&bdi->wb_lock); return; + } + spin_unlock_bh(&bdi->wb_lock); /* * Make sure nobody finds us on the bdi_list anymore */ bdi_remove_from_list(bdi); - /* Make sure nobody queues further work */ - spin_lock_bh(&bdi->wb_lock); - clear_bit(BDI_registered, &bdi->state); - spin_unlock_bh(&bdi->wb_lock); - /* * Drain work list and shutdown the delayed_work. At this point, * @bdi->bdi_list is empty telling bdi_Writeback_workfn() that @bdi @@ -375,37 +357,22 @@ static void bdi_wb_shutdown(struct backing_dev_info *bdi) */ mod_delayed_work(bdi_wq, &bdi->wb.dwork, 0); flush_delayed_work(&bdi->wb.dwork); - WARN_ON(!list_empty(&bdi->work_list)); - WARN_ON(delayed_work_pending(&bdi->wb.dwork)); } /* - * This bdi is going away now, make sure that no super_blocks point to it + * Called when the device behind @bdi has been removed or ejected. + * + * We can't really do much here except for reducing the dirty ratio at + * the moment. In the future we should be able to set a flag so that + * the filesystem can handle errors at mark_inode_dirty time instead + * of only at writeback time. */ -static void bdi_prune_sb(struct backing_dev_info *bdi) -{ - struct super_block *sb; - - spin_lock(&sb_lock); - list_for_each_entry(sb, &super_blocks, s_list) { - if (sb->s_bdi == bdi) - sb->s_bdi = &default_backing_dev_info; - } - spin_unlock(&sb_lock); -} - void bdi_unregister(struct backing_dev_info *bdi) { - if (bdi->dev) { - bdi_set_min_ratio(bdi, 0); - trace_writeback_bdi_unregister(bdi); - bdi_prune_sb(bdi); + if (WARN_ON_ONCE(!bdi->dev)) + return; - bdi_wb_shutdown(bdi); - bdi_debug_unregister(bdi); - device_unregister(bdi->dev); - bdi->dev = NULL; - } + bdi_set_min_ratio(bdi, 0); } EXPORT_SYMBOL(bdi_unregister); @@ -418,6 +385,7 @@ static void bdi_wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi) INIT_LIST_HEAD(&wb->b_dirty); INIT_LIST_HEAD(&wb->b_io); INIT_LIST_HEAD(&wb->b_more_io); + INIT_LIST_HEAD(&wb->b_dirty_time); spin_lock_init(&wb->list_lock); INIT_DELAYED_WORK(&wb->dwork, bdi_writeback_workfn); } @@ -474,37 +442,19 @@ void bdi_destroy(struct backing_dev_info *bdi) { int i; - /* - * Splice our entries to the default_backing_dev_info. This - * condition shouldn't happen. @wb must be empty at this point and - * dirty inodes on it might cause other issues. This workaround is - * added by ce5f8e779519 ("writeback: splice dirty inode entries to - * default bdi on bdi_destroy()") without root-causing the issue. - * - * http://lkml.kernel.org/g/1253038617-30204-11-git-send-email-jens.axboe@oracle.com - * http://thread.gmane.org/gmane.linux.file-systems/35341/focus=35350 - * - * We should probably add WARN_ON() to find out whether it still - * happens and track it down if so. - */ - if (bdi_has_dirty_io(bdi)) { - struct bdi_writeback *dst = &default_backing_dev_info.wb; - - bdi_lock_two(&bdi->wb, dst); - list_splice(&bdi->wb.b_dirty, &dst->b_dirty); - list_splice(&bdi->wb.b_io, &dst->b_io); - list_splice(&bdi->wb.b_more_io, &dst->b_more_io); - spin_unlock(&bdi->wb.list_lock); - spin_unlock(&dst->list_lock); - } - - bdi_unregister(bdi); + bdi_wb_shutdown(bdi); + WARN_ON(!list_empty(&bdi->work_list)); WARN_ON(delayed_work_pending(&bdi->wb.dwork)); + if (bdi->dev) { + bdi_debug_unregister(bdi); + device_unregister(bdi->dev); + bdi->dev = NULL; + } + for (i = 0; i < NR_BDI_STAT_ITEMS; i++) percpu_counter_destroy(&bdi->bdi_stat[i]); - fprop_local_destroy_percpu(&bdi->completions); } EXPORT_SYMBOL(bdi_destroy); @@ -513,13 +463,12 @@ EXPORT_SYMBOL(bdi_destroy); * For use from filesystems to quickly init and register a bdi associated * with dirty writeback */ -int bdi_setup_and_register(struct backing_dev_info *bdi, char *name, - unsigned int cap) +int bdi_setup_and_register(struct backing_dev_info *bdi, char *name) { int err; bdi->name = name; - bdi->capabilities = cap; + bdi->capabilities = 0; err = bdi_init(bdi); if (err) return err; |