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-rw-r--r--mm/backing-dev.c117
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;
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.