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raspberrypi-kernel
提交 a12e4d30 编写于 作者: L Linus Torvalds
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Merge branch 'writeback' of git://git.kernel.dk/linux-2.6-block 

* 'writeback' of git://git.kernel.dk/linux-2.6-block:
  writeback: check for registered bdi in flusher add and inode dirty
  writeback: add name to backing_dev_info
  writeback: add some debug inode list counters to bdi stats
  writeback: get rid of pdflush completely
  writeback: switch to per-bdi threads for flushing data
  writeback: move dirty inodes from super_block to backing_dev_info
  writeback: get rid of generic_sync_sb_inodes() export
上级 89af571c 500b067c
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Showing with 1285 addition and 778 deletion
block/blk-core.c
浏览文件 @ a12e4d30
......@@ -501,6 +501,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
(VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
q->backing_dev_info.state = 0;
q->backing_dev_info.capabilities = BDI_CAP_MAP_COPY;
q->backing_dev_info.name = "block";
err = bdi_init(&q->backing_dev_info);
if (err) {
......
drivers/block/aoe/aoeblk.c
浏览文件 @ a12e4d30
......@@ -268,6 +268,7 @@ aoeblk_gdalloc(void *vp)
if (!d->blkq)
goto err_mempool;
blk_queue_make_request(d->blkq, aoeblk_make_request);
d->blkq->backing_dev_info.name = "aoe";
if (bdi_init(&d->blkq->backing_dev_info))
goto err_blkq;
spin_lock_irqsave(&d->lock, flags);
......
drivers/char/mem.c
浏览文件 @ a12e4d30
......@@ -822,6 +822,7 @@ static const struct file_operations zero_fops = {
* - permits private mappings, "copies" are taken of the source of zeros
*/
static struct backing_dev_info zero_bdi = {
.name = "char/mem",
.capabilities = BDI_CAP_MAP_COPY,
};
......
drivers/staging/pohmelfs/inode.c
浏览文件 @ a12e4d30
......@@ -1950,14 +1950,7 @@ static int pohmelfs_get_sb(struct file_system_type *fs_type,
*/
static void pohmelfs_kill_super(struct super_block *sb)
{
struct writeback_control wbc = {
.sync_mode = WB_SYNC_ALL,
.range_start = 0,
.range_end = LLONG_MAX,
.nr_to_write = LONG_MAX,
};
generic_sync_sb_inodes(sb, &wbc);
sync_inodes_sb(sb);
kill_anon_super(sb);
}
......
fs/btrfs/disk-io.c
浏览文件 @ a12e4d30
......@@ -1352,6 +1352,7 @@ static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
{
int err;
bdi->name = "btrfs";
bdi->capabilities = BDI_CAP_MAP_COPY;
err = bdi_init(bdi);
if (err)
......
fs/buffer.c
浏览文件 @ a12e4d30
......@@ -281,7 +281,7 @@ static void free_more_memory(void)
struct zone *zone;
int nid;
wakeup_pdflush(1024);
wakeup_flusher_threads(1024);
yield();
for_each_online_node(nid) {
......
fs/char_dev.c
浏览文件 @ a12e4d30
......@@ -31,6 +31,7 @@
* - no readahead or I/O queue unplugging required
*/
struct backing_dev_info directly_mappable_cdev_bdi = {
.name = "char",
.capabilities = (
#ifdef CONFIG_MMU
/* permit private copies of the data to be taken */
......
fs/configfs/inode.c
浏览文件 @ a12e4d30
......@@ -51,6 +51,7 @@ static const struct address_space_operations configfs_aops = {
};
static struct backing_dev_info configfs_backing_dev_info = {
.name = "configfs",
.ra_pages = 0, /* No readahead */
.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
};
......
fs/fs-writeback.c
浏览文件 @ a12e4d30
......@@ -19,171 +19,223 @@
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/kthread.h>
#include <linux/freezer.h>
#include <linux/writeback.h>
#include <linux/blkdev.h>
#include <linux/backing-dev.h>
#include <linux/buffer_head.h>
#include "internal.h"
#define inode_to_bdi(inode) ((inode)->i_mapping->backing_dev_info)
/**
* writeback_acquire - attempt to get exclusive writeback access to a device
* @bdi: the device's backing_dev_info structure
*
* It is a waste of resources to have more than one pdflush thread blocked on
* a single request queue. Exclusion at the request_queue level is obtained
* via a flag in the request_queue's backing_dev_info.state.
*
* Non-request_queue-backed address_spaces will share default_backing_dev_info,
* unless they implement their own. Which is somewhat inefficient, as this
* may prevent concurrent writeback against multiple devices.
/*
* We don't actually have pdflush, but this one is exported though /proc...
*/
static int writeback_acquire(struct backing_dev_info *bdi)
int nr_pdflush_threads;
/*
* Work items for the bdi_writeback threads
*/
struct bdi_work {
struct list_head list;
struct list_head wait_list;
struct rcu_head rcu_head;
unsigned long seen;
atomic_t pending;
struct super_block *sb;
unsigned long nr_pages;
enum writeback_sync_modes sync_mode;
unsigned long state;
};
enum {
WS_USED_B = 0,
WS_ONSTACK_B,
};
#define WS_USED (1 << WS_USED_B)
#define WS_ONSTACK (1 << WS_ONSTACK_B)
static inline bool bdi_work_on_stack(struct bdi_work *work)
{
return !test_and_set_bit(BDI_pdflush, &bdi->state);
return test_bit(WS_ONSTACK_B, &work->state);
}
static inline void bdi_work_init(struct bdi_work *work,
struct writeback_control *wbc)
{
INIT_RCU_HEAD(&work->rcu_head);
work->sb = wbc->sb;
work->nr_pages = wbc->nr_to_write;
work->sync_mode = wbc->sync_mode;
work->state = WS_USED;
}
static inline void bdi_work_init_on_stack(struct bdi_work *work,
struct writeback_control *wbc)
{
bdi_work_init(work, wbc);
work->state |= WS_ONSTACK;
}
/**
* writeback_in_progress - determine whether there is writeback in progress
* @bdi: the device's backing_dev_info structure.
*
* Determine whether there is writeback in progress against a backing device.
* Determine whether there is writeback waiting to be handled against a
* backing device.
*/
int writeback_in_progress(struct backing_dev_info *bdi)
{
return test_bit(BDI_pdflush, &bdi->state);
return !list_empty(&bdi->work_list);
}
/**
* writeback_release - relinquish exclusive writeback access against a device.
* @bdi: the device's backing_dev_info structure
*/
static void writeback_release(struct backing_dev_info *bdi)
static void bdi_work_clear(struct bdi_work *work)
{
BUG_ON(!writeback_in_progress(bdi));
clear_bit(BDI_pdflush, &bdi->state);
clear_bit(WS_USED_B, &work->state);
smp_mb__after_clear_bit();
wake_up_bit(&work->state, WS_USED_B);
}
static noinline void block_dump___mark_inode_dirty(struct inode *inode)
static void bdi_work_free(struct rcu_head *head)
{
if (inode->i_ino || strcmp(inode->i_sb->s_id, "bdev")) {
struct dentry *dentry;
const char *name = "?";
struct bdi_work *work = container_of(head, struct bdi_work, rcu_head);
dentry = d_find_alias(inode);
if (dentry) {
spin_lock(&dentry->d_lock);
name = (const char *) dentry->d_name.name;
}
printk(KERN_DEBUG
"%s(%d): dirtied inode %lu (%s) on %s\n",
current->comm, task_pid_nr(current), inode->i_ino,
name, inode->i_sb->s_id);
if (dentry) {
spin_unlock(&dentry->d_lock);
dput(dentry);
}
}
if (!bdi_work_on_stack(work))
kfree(work);
else
bdi_work_clear(work);
}
/**
* __mark_inode_dirty - internal function
* @inode: inode to mark
* @flags: what kind of dirty (i.e. I_DIRTY_SYNC)
* Mark an inode as dirty. Callers should use mark_inode_dirty or
* mark_inode_dirty_sync.
*
* Put the inode on the super block's dirty list.
*
* CAREFUL! We mark it dirty unconditionally, but move it onto the
* dirty list only if it is hashed or if it refers to a blockdev.
* If it was not hashed, it will never be added to the dirty list
* even if it is later hashed, as it will have been marked dirty already.
*
* In short, make sure you hash any inodes _before_ you start marking
* them dirty.
*
* This function *must* be atomic for the I_DIRTY_PAGES case -
* set_page_dirty() is called under spinlock in several places.
*
* Note that for blockdevs, inode->dirtied_when represents the dirtying time of
* the block-special inode (/dev/hda1) itself. And the ->dirtied_when field of
* the kernel-internal blockdev inode represents the dirtying time of the
* blockdev's pages. This is why for I_DIRTY_PAGES we always use
* page->mapping->host, so the page-dirtying time is recorded in the internal
* blockdev inode.
*/
void __mark_inode_dirty(struct inode *inode, int flags)
static void wb_work_complete(struct bdi_work *work)
{
struct super_block *sb = inode->i_sb;
const enum writeback_sync_modes sync_mode = work->sync_mode;
/*
* Don't do this for I_DIRTY_PAGES - that doesn't actually
* dirty the inode itself
* For allocated work, we can clear the done/seen bit right here.
* For on-stack work, we need to postpone both the clear and free
* to after the RCU grace period, since the stack could be invalidated
* as soon as bdi_work_clear() has done the wakeup.
*/
if (flags & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) {
if (sb->s_op->dirty_inode)
sb->s_op->dirty_inode(inode);
}
if (!bdi_work_on_stack(work))
bdi_work_clear(work);
if (sync_mode == WB_SYNC_NONE || bdi_work_on_stack(work))
call_rcu(&work->rcu_head, bdi_work_free);
}
static void wb_clear_pending(struct bdi_writeback *wb, struct bdi_work *work)
{
/*
* make sure that changes are seen by all cpus before we test i_state
* -- mikulas
* The caller has retrieved the work arguments from this work,
* drop our reference. If this is the last ref, delete and free it
*/
smp_mb();
if (atomic_dec_and_test(&work->pending)) {
struct backing_dev_info *bdi = wb->bdi;
/* avoid the locking if we can */
if ((inode->i_state & flags) == flags)
return;
spin_lock(&bdi->wb_lock);
list_del_rcu(&work->list);
spin_unlock(&bdi->wb_lock);
if (unlikely(block_dump))
block_dump___mark_inode_dirty(inode);
spin_lock(&inode_lock);
if ((inode->i_state & flags) != flags) {
const int was_dirty = inode->i_state & I_DIRTY;
wb_work_complete(work);
}
}
inode->i_state |= flags;
static void bdi_queue_work(struct backing_dev_info *bdi, struct bdi_work *work)
{
if (work) {
work->seen = bdi->wb_mask;
BUG_ON(!work->seen);
atomic_set(&work->pending, bdi->wb_cnt);
BUG_ON(!bdi->wb_cnt);
/*
* If the inode is being synced, just update its dirty state.
* The unlocker will place the inode on the appropriate
* superblock list, based upon its state.
* Make sure stores are seen before it appears on the list
*/
if (inode->i_state & I_SYNC)
goto out;
smp_mb();
/*
* Only add valid (hashed) inodes to the superblock's
* dirty list. Add blockdev inodes as well.
*/
if (!S_ISBLK(inode->i_mode)) {
if (hlist_unhashed(&inode->i_hash))
goto out;
}
if (inode->i_state & (I_FREEING|I_CLEAR))
goto out;
spin_lock(&bdi->wb_lock);
list_add_tail_rcu(&work->list, &bdi->work_list);
spin_unlock(&bdi->wb_lock);
}
/*
* If the default thread isn't there, make sure we add it. When
* it gets created and wakes up, we'll run this work.
*/
if (unlikely(list_empty_careful(&bdi->wb_list)))
wake_up_process(default_backing_dev_info.wb.task);
else {
struct bdi_writeback *wb = &bdi->wb;
/*
* If the inode was already on s_dirty/s_io/s_more_io, don't
* reposition it (that would break s_dirty time-ordering).
* If we failed allocating the bdi work item, wake up the wb
* thread always. As a safety precaution, it'll flush out
* everything
*/
if (!was_dirty) {
inode->dirtied_when = jiffies;
list_move(&inode->i_list, &sb->s_dirty);
}
if (!wb_has_dirty_io(wb)) {
if (work)
wb_clear_pending(wb, work);
} else if (wb->task)
wake_up_process(wb->task);
}
out:
spin_unlock(&inode_lock);
}
EXPORT_SYMBOL(__mark_inode_dirty);
/*
* Used for on-stack allocated work items. The caller needs to wait until
* the wb threads have acked the work before it's safe to continue.
*/
static void bdi_wait_on_work_clear(struct bdi_work *work)
{
wait_on_bit(&work->state, WS_USED_B, bdi_sched_wait,
TASK_UNINTERRUPTIBLE);
}
static int write_inode(struct inode *inode, int sync)
static struct bdi_work *bdi_alloc_work(struct writeback_control *wbc)
{
if (inode->i_sb->s_op->write_inode && !is_bad_inode(inode))
return inode->i_sb->s_op->write_inode(inode, sync);
return 0;
struct bdi_work *work;
work = kmalloc(sizeof(*work), GFP_ATOMIC);
if (work)
bdi_work_init(work, wbc);
return work;
}
void bdi_start_writeback(struct writeback_control *wbc)
{
const bool must_wait = wbc->sync_mode == WB_SYNC_ALL;
struct bdi_work work_stack, *work = NULL;
if (!must_wait)
work = bdi_alloc_work(wbc);
if (!work) {
work = &work_stack;
bdi_work_init_on_stack(work, wbc);
}
bdi_queue_work(wbc->bdi, work);
/*
* If the sync mode is WB_SYNC_ALL, block waiting for the work to
* complete. If not, we only need to wait for the work to be started,
* if we allocated it on-stack. We use the same mechanism, if the
* wait bit is set in the bdi_work struct, then threads will not
* clear pending until after they are done.
*
* Note that work == &work_stack if must_wait is true, so we don't
* need to do call_rcu() here ever, since the completion path will
* have done that for us.
*/
if (must_wait || work == &work_stack) {
bdi_wait_on_work_clear(work);
if (work != &work_stack)
call_rcu(&work->rcu_head, bdi_work_free);
}
}
/*
......@@ -191,31 +243,32 @@ static int write_inode(struct inode *inode, int sync)
* furthest end of its superblock's dirty-inode list.
*
* Before stamping the inode's ->dirtied_when, we check to see whether it is
* already the most-recently-dirtied inode on the s_dirty list. If that is
* already the most-recently-dirtied inode on the b_dirty list. If that is
* the case then the inode must have been redirtied while it was being written
* out and we don't reset its dirtied_when.
*/
static void redirty_tail(struct inode *inode)
{
struct super_block *sb = inode->i_sb;
struct bdi_writeback *wb = &inode_to_bdi(inode)->wb;
if (!list_empty(&sb->s_dirty)) {
struct inode *tail_inode;
if (!list_empty(&wb->b_dirty)) {
struct inode *tail;
tail_inode = list_entry(sb->s_dirty.next, struct inode, i_list);
if (time_before(inode->dirtied_when,
tail_inode->dirtied_when))
tail = list_entry(wb->b_dirty.next, struct inode, i_list);
if (time_before(inode->dirtied_when, tail->dirtied_when))
inode->dirtied_when = jiffies;
}
list_move(&inode->i_list, &sb->s_dirty);
list_move(&inode->i_list, &wb->b_dirty);
}
/*
* requeue inode for re-scanning after sb->s_io list is exhausted.
* requeue inode for re-scanning after bdi->b_io list is exhausted.
*/
static void requeue_io(struct inode *inode)
{
list_move(&inode->i_list, &inode->i_sb->s_more_io);
struct bdi_writeback *wb = &inode_to_bdi(inode)->wb;
list_move(&inode->i_list, &wb->b_more_io);
}
static void inode_sync_complete(struct inode *inode)
......@@ -262,20 +315,18 @@ static void move_expired_inodes(struct list_head *delaying_queue,
/*
* Queue all expired dirty inodes for io, eldest first.
*/
static void queue_io(struct super_block *sb,
unsigned long *older_than_this)
static void queue_io(struct bdi_writeback *wb, unsigned long *older_than_this)
{
list_splice_init(&sb->s_more_io, sb->s_io.prev);
move_expired_inodes(&sb->s_dirty, &sb->s_io, older_than_this);
list_splice_init(&wb->b_more_io, wb->b_io.prev);
move_expired_inodes(&wb->b_dirty, &wb->b_io, older_than_this);
}
int sb_has_dirty_inodes(struct super_block *sb)
static int write_inode(struct inode *inode, int sync)
{
return !list_empty(&sb->s_dirty) ||
!list_empty(&sb->s_io) ||
!list_empty(&sb->s_more_io);
if (inode->i_sb->s_op->write_inode && !is_bad_inode(inode))
return inode->i_sb->s_op->write_inode(inode, sync);
return 0;
}
EXPORT_SYMBOL(sb_has_dirty_inodes);
/*
* Wait for writeback on an inode to complete.
......@@ -322,11 +373,11 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
if (inode->i_state & I_SYNC) {
/*
* If this inode is locked for writeback and we are not doing
* writeback-for-data-integrity, move it to s_more_io so that
* writeback-for-data-integrity, move it to b_more_io so that
* writeback can proceed with the other inodes on s_io.
*
* We'll have another go at writing back this inode when we
* completed a full scan of s_io.
* completed a full scan of b_io.
*/
if (!wait) {
requeue_io(inode);
......@@ -371,11 +422,11 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
/*
* We didn't write back all the pages. nfs_writepages()
* sometimes bales out without doing anything. Redirty
* the inode; Move it from s_io onto s_more_io/s_dirty.
* the inode; Move it from b_io onto b_more_io/b_dirty.
*/
/*
* akpm: if the caller was the kupdate function we put
* this inode at the head of s_dirty so it gets first
* this inode at the head of b_dirty so it gets first
* consideration. Otherwise, move it to the tail, for
* the reasons described there. I'm not really sure
* how much sense this makes. Presumably I had a good
......@@ -385,7 +436,7 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
if (wbc->for_kupdate) {
/*
* For the kupdate function we move the inode
* to s_more_io so it will get more writeout as
* to b_more_io so it will get more writeout as
* soon as the queue becomes uncongested.
*/
inode->i_state |= I_DIRTY_PAGES;
......@@ -434,50 +485,84 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
}
/*
* Write out a superblock's list of dirty inodes. A wait will be performed
* upon no inodes, all inodes or the final one, depending upon sync_mode.
*
* If older_than_this is non-NULL, then only write out inodes which
* had their first dirtying at a time earlier than *older_than_this.
*
* If we're a pdflush thread, then implement pdflush collision avoidance
* against the entire list.
* For WB_SYNC_NONE writeback, the caller does not have the sb pinned
* before calling writeback. So make sure that we do pin it, so it doesn't
* go away while we are writing inodes from it.
*
* If `bdi' is non-zero then we're being asked to writeback a specific queue.
* This function assumes that the blockdev superblock's inodes are backed by
* a variety of queues, so all inodes are searched. For other superblocks,
* assume that all inodes are backed by the same queue.
*
* FIXME: this linear search could get expensive with many fileystems. But
* how to fix? We need to go from an address_space to all inodes which share
* a queue with that address_space. (Easy: have a global "dirty superblocks"
* list).
*
* The inodes to be written are parked on sb->s_io. They are moved back onto
* sb->s_dirty as they are selected for writing. This way, none can be missed
* on the writer throttling path, and we get decent balancing between many
* throttled threads: we don't want them all piling up on inode_sync_wait.
* Returns 0 if the super was successfully pinned (or pinning wasn't needed),
* 1 if we failed.
*/
void generic_sync_sb_inodes(struct super_block *sb,
static int pin_sb_for_writeback(struct writeback_control *wbc,
struct inode *inode)
{
struct super_block *sb = inode->i_sb;
/*
* Caller must already hold the ref for this
*/
if (wbc->sync_mode == WB_SYNC_ALL) {
WARN_ON(!rwsem_is_locked(&sb->s_umount));
return 0;
}
spin_lock(&sb_lock);
sb->s_count++;
if (down_read_trylock(&sb->s_umount)) {
if (sb->s_root) {
spin_unlock(&sb_lock);
return 0;
}
/*
* umounted, drop rwsem again and fall through to failure
*/
up_read(&sb->s_umount);
}
sb->s_count--;
spin_unlock(&sb_lock);
return 1;
}
static void unpin_sb_for_writeback(struct writeback_control *wbc,
struct inode *inode)
{
struct super_block *sb = inode->i_sb;
if (wbc->sync_mode == WB_SYNC_ALL)
return;
up_read(&sb->s_umount);
put_super(sb);
}
static void writeback_inodes_wb(struct bdi_writeback *wb,
struct writeback_control *wbc)
{
struct super_block *sb = wbc->sb;
const int is_blkdev_sb = sb_is_blkdev_sb(sb);
const unsigned long start = jiffies; /* livelock avoidance */
int sync = wbc->sync_mode == WB_SYNC_ALL;
spin_lock(&inode_lock);
if (!wbc->for_kupdate || list_empty(&sb->s_io))
queue_io(sb, wbc->older_than_this);
while (!list_empty(&sb->s_io)) {
struct inode *inode = list_entry(sb->s_io.prev,
if (!wbc->for_kupdate || list_empty(&wb->b_io))
queue_io(wb, wbc->older_than_this);
while (!list_empty(&wb->b_io)) {
struct inode *inode = list_entry(wb->b_io.prev,
struct inode, i_list);
struct address_space *mapping = inode->i_mapping;
struct backing_dev_info *bdi = mapping->backing_dev_info;
long pages_skipped;
if (!bdi_cap_writeback_dirty(bdi)) {
/*
* super block given and doesn't match, skip this inode
*/
if (sb && sb != inode->i_sb) {
redirty_tail(inode);
continue;
}
if (!bdi_cap_writeback_dirty(wb->bdi)) {
redirty_tail(inode);
if (sb_is_blkdev_sb(sb)) {
if (is_blkdev_sb) {
/*
* Dirty memory-backed blockdev: the ramdisk
* driver does this. Skip just this inode
......@@ -497,21 +582,14 @@ void generic_sync_sb_inodes(struct super_block *sb,
continue;
}
if (wbc->nonblocking && bdi_write_congested(bdi)) {
if (wbc->nonblocking && bdi_write_congested(wb->bdi)) {
wbc->encountered_congestion = 1;
if (!sb_is_blkdev_sb(sb))
if (!is_blkdev_sb)
break; /* Skip a congested fs */
requeue_io(inode);
continue; /* Skip a congested blockdev */
}
if (wbc->bdi && bdi != wbc->bdi) {
if (!sb_is_blkdev_sb(sb))
break; /* fs has the wrong queue */
requeue_io(inode);
continue; /* blockdev has wrong queue */
}
/*
* Was this inode dirtied after sync_sb_inodes was called?
* This keeps sync from extra jobs and livelock.
......@@ -519,16 +597,16 @@ void generic_sync_sb_inodes(struct super_block *sb,
if (inode_dirtied_after(inode, start))
break;
/* Is another pdflush already flushing this queue? */
if (current_is_pdflush() && !writeback_acquire(bdi))
break;
if (pin_sb_for_writeback(wbc, inode)) {
requeue_io(inode);
continue;
}
BUG_ON(inode->i_state & (I_FREEING | I_CLEAR));
__iget(inode);
pages_skipped = wbc->pages_skipped;
writeback_single_inode(inode, wbc);
if (current_is_pdflush())
writeback_release(bdi);
unpin_sb_for_writeback(wbc, inode);
if (wbc->pages_skipped != pages_skipped) {
/*
* writeback is not making progress due to locked
......@@ -544,144 +622,571 @@ void generic_sync_sb_inodes(struct super_block *sb,
wbc->more_io = 1;
break;
}
if (!list_empty(&sb->s_more_io))
if (!list_empty(&wb->b_more_io))
wbc->more_io = 1;
}
if (sync) {
struct inode *inode, *old_inode = NULL;
spin_unlock(&inode_lock);
/* Leave any unwritten inodes on b_io */
}
void writeback_inodes_wbc(struct writeback_control *wbc)
{
struct backing_dev_info *bdi = wbc->bdi;
writeback_inodes_wb(&bdi->wb, wbc);
}
/*
* The maximum number of pages to writeout in a single bdi flush/kupdate
* operation. We do this so we don't hold I_SYNC against an inode for
* enormous amounts of time, which would block a userspace task which has
* been forced to throttle against that inode. Also, the code reevaluates
* the dirty each time it has written this many pages.
*/
#define MAX_WRITEBACK_PAGES 1024
static inline bool over_bground_thresh(void)
{
unsigned long background_thresh, dirty_thresh;
get_dirty_limits(&background_thresh, &dirty_thresh, NULL, NULL);
return (global_page_state(NR_FILE_DIRTY) +
global_page_state(NR_UNSTABLE_NFS) >= background_thresh);
}
/*
* Explicit flushing or periodic writeback of "old" data.
*
* Define "old": the first time one of an inode's pages is dirtied, we mark the
* dirtying-time in the inode's address_space. So this periodic writeback code
* just walks the superblock inode list, writing back any inodes which are
* older than a specific point in time.
*
* Try to run once per dirty_writeback_interval. But if a writeback event
* takes longer than a dirty_writeback_interval interval, then leave a
* one-second gap.
*
* older_than_this takes precedence over nr_to_write. So we'll only write back
* all dirty pages if they are all attached to "old" mappings.
*/
static long wb_writeback(struct bdi_writeback *wb, long nr_pages,
struct super_block *sb,
enum writeback_sync_modes sync_mode, int for_kupdate)
{
struct writeback_control wbc = {
.bdi = wb->bdi,
.sb = sb,
.sync_mode = sync_mode,
.older_than_this = NULL,
.for_kupdate = for_kupdate,
.range_cyclic = 1,
};
unsigned long oldest_jif;
long wrote = 0;
if (wbc.for_kupdate) {
wbc.older_than_this = &oldest_jif;
oldest_jif = jiffies -
msecs_to_jiffies(dirty_expire_interval * 10);
}
for (;;) {
/*
* Data integrity sync. Must wait for all pages under writeback,
* because there may have been pages dirtied before our sync
* call, but which had writeout started before we write it out.
* In which case, the inode may not be on the dirty list, but
* we still have to wait for that writeout.
* Don't flush anything for non-integrity writeback where
* no nr_pages was given
*/
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
struct address_space *mapping;
if (!for_kupdate && nr_pages <= 0 && sync_mode == WB_SYNC_NONE)
break;
if (inode->i_state &
(I_FREEING|I_CLEAR|I_WILL_FREE|I_NEW))
continue;
mapping = inode->i_mapping;
if (mapping->nrpages == 0)
/*
* If no specific pages were given and this is just a
* periodic background writeout and we are below the
* background dirty threshold, don't do anything
*/
if (for_kupdate && nr_pages <= 0 && !over_bground_thresh())
break;
wbc.more_io = 0;
wbc.encountered_congestion = 0;
wbc.nr_to_write = MAX_WRITEBACK_PAGES;
wbc.pages_skipped = 0;
writeback_inodes_wb(wb, &wbc);
nr_pages -= MAX_WRITEBACK_PAGES - wbc.nr_to_write;
wrote += MAX_WRITEBACK_PAGES - wbc.nr_to_write;
/*
* If we ran out of stuff to write, bail unless more_io got set
*/
if (wbc.nr_to_write > 0 || wbc.pages_skipped > 0) {
if (wbc.more_io && !wbc.for_kupdate)
continue;
__iget(inode);
spin_unlock(&inode_lock);
break;
}
}
return wrote;
}
/*
* Return the next bdi_work struct that hasn't been processed by this
* wb thread yet
*/
static struct bdi_work *get_next_work_item(struct backing_dev_info *bdi,
struct bdi_writeback *wb)
{
struct bdi_work *work, *ret = NULL;
rcu_read_lock();
list_for_each_entry_rcu(work, &bdi->work_list, list) {
if (!test_and_clear_bit(wb->nr, &work->seen))
continue;
ret = work;
break;
}
rcu_read_unlock();
return ret;
}
static long wb_check_old_data_flush(struct bdi_writeback *wb)
{
unsigned long expired;
long nr_pages;
expired = wb->last_old_flush +
msecs_to_jiffies(dirty_writeback_interval * 10);
if (time_before(jiffies, expired))
return 0;
wb->last_old_flush = jiffies;
nr_pages = global_page_state(NR_FILE_DIRTY) +
global_page_state(NR_UNSTABLE_NFS) +
(inodes_stat.nr_inodes - inodes_stat.nr_unused);
if (nr_pages)
return wb_writeback(wb, nr_pages, NULL, WB_SYNC_NONE, 1);
return 0;
}
/*
* Retrieve work items and do the writeback they describe
*/
long wb_do_writeback(struct bdi_writeback *wb, int force_wait)
{
struct backing_dev_info *bdi = wb->bdi;
struct bdi_work *work;
long nr_pages, wrote = 0;
while ((work = get_next_work_item(bdi, wb)) != NULL) {
enum writeback_sync_modes sync_mode;
nr_pages = work->nr_pages;
/*
* Override sync mode, in case we must wait for completion
*/
if (force_wait)
work->sync_mode = sync_mode = WB_SYNC_ALL;
else
sync_mode = work->sync_mode;
/*
* If this isn't a data integrity operation, just notify
* that we have seen this work and we are now starting it.
*/
if (sync_mode == WB_SYNC_NONE)
wb_clear_pending(wb, work);
wrote += wb_writeback(wb, nr_pages, work->sb, sync_mode, 0);
/*
* This is a data integrity writeback, so only do the
* notification when we have completed the work.
*/
if (sync_mode == WB_SYNC_ALL)
wb_clear_pending(wb, work);
}
/*
* Check for periodic writeback, kupdated() style
*/
wrote += wb_check_old_data_flush(wb);
return wrote;
}
/*
* Handle writeback of dirty data for the device backed by this bdi. Also
* wakes up periodically and does kupdated style flushing.
*/
int bdi_writeback_task(struct bdi_writeback *wb)
{
unsigned long last_active = jiffies;
unsigned long wait_jiffies = -1UL;
long pages_written;
while (!kthread_should_stop()) {
pages_written = wb_do_writeback(wb, 0);
if (pages_written)
last_active = jiffies;
else if (wait_jiffies != -1UL) {
unsigned long max_idle;
/*
* We hold a reference to 'inode' so it couldn't have
* been removed from s_inodes list while we dropped the
* inode_lock. We cannot iput the inode now as we can
* be holding the last reference and we cannot iput it
* under inode_lock. So we keep the reference and iput
* it later.
* Longest period of inactivity that we tolerate. If we
* see dirty data again later, the task will get
* recreated automatically.
*/
iput(old_inode);
old_inode = inode;
max_idle = max(5UL * 60 * HZ, wait_jiffies);
if (time_after(jiffies, max_idle + last_active))
break;
}
filemap_fdatawait(mapping);
wait_jiffies = msecs_to_jiffies(dirty_writeback_interval * 10);
set_current_state(TASK_INTERRUPTIBLE);
schedule_timeout(wait_jiffies);
try_to_freeze();
}
cond_resched();
return 0;
}
/*
* Schedule writeback for all backing devices. Expensive! If this is a data
* integrity operation, writeback will be complete when this returns. If
* we are simply called for WB_SYNC_NONE, then writeback will merely be
* scheduled to run.
*/
static void bdi_writeback_all(struct writeback_control *wbc)
{
const bool must_wait = wbc->sync_mode == WB_SYNC_ALL;
struct backing_dev_info *bdi;
struct bdi_work *work;
LIST_HEAD(list);
restart:
spin_lock(&bdi_lock);
list_for_each_entry(bdi, &bdi_list, bdi_list) {
struct bdi_work *work;
spin_lock(&inode_lock);
if (!bdi_has_dirty_io(bdi))
continue;
/*
* If work allocation fails, do the writes inline. We drop
* the lock and restart the list writeout. This should be OK,
* since this happens rarely and because the writeout should
* eventually make more free memory available.
*/
work = bdi_alloc_work(wbc);
if (!work) {
struct writeback_control __wbc;
/*
* Not a data integrity writeout, just continue
*/
if (!must_wait)
continue;
spin_unlock(&bdi_lock);
__wbc = *wbc;
__wbc.bdi = bdi;
writeback_inodes_wbc(&__wbc);
goto restart;
}
spin_unlock(&inode_lock);
iput(old_inode);
} else
spin_unlock(&inode_lock);
if (must_wait)
list_add_tail(&work->wait_list, &list);
bdi_queue_work(bdi, work);
}
spin_unlock(&bdi_lock);
return; /* Leave any unwritten inodes on s_io */
/*
* If this is for WB_SYNC_ALL, wait for pending work to complete
* before returning.
*/
while (!list_empty(&list)) {
work = list_entry(list.next, struct bdi_work, wait_list);
list_del(&work->wait_list);
bdi_wait_on_work_clear(work);
call_rcu(&work->rcu_head, bdi_work_free);
}
}
EXPORT_SYMBOL_GPL(generic_sync_sb_inodes);
static void sync_sb_inodes(struct super_block *sb,
struct writeback_control *wbc)
/*
* Start writeback of `nr_pages' pages. If `nr_pages' is zero, write back
* the whole world.
*/
void wakeup_flusher_threads(long nr_pages)
{
generic_sync_sb_inodes(sb, wbc);
struct writeback_control wbc = {
.sync_mode = WB_SYNC_NONE,
.older_than_this = NULL,
.range_cyclic = 1,
};
if (nr_pages == 0)
nr_pages = global_page_state(NR_FILE_DIRTY) +
global_page_state(NR_UNSTABLE_NFS);
wbc.nr_to_write = nr_pages;
bdi_writeback_all(&wbc);
}
/*
* Start writeback of dirty pagecache data against all unlocked inodes.
static noinline void block_dump___mark_inode_dirty(struct inode *inode)
{
if (inode->i_ino || strcmp(inode->i_sb->s_id, "bdev")) {
struct dentry *dentry;
const char *name = "?";
dentry = d_find_alias(inode);
if (dentry) {
spin_lock(&dentry->d_lock);
name = (const char *) dentry->d_name.name;
}
printk(KERN_DEBUG
"%s(%d): dirtied inode %lu (%s) on %s\n",
current->comm, task_pid_nr(current), inode->i_ino,
name, inode->i_sb->s_id);
if (dentry) {
spin_unlock(&dentry->d_lock);
dput(dentry);
}
}
}
/**
* __mark_inode_dirty - internal function
* @inode: inode to mark
* @flags: what kind of dirty (i.e. I_DIRTY_SYNC)
* Mark an inode as dirty. Callers should use mark_inode_dirty or
* mark_inode_dirty_sync.
*
* Note:
* We don't need to grab a reference to superblock here. If it has non-empty
* ->s_dirty it's hadn't been killed yet and kill_super() won't proceed
* past sync_inodes_sb() until the ->s_dirty/s_io/s_more_io lists are all
* empty. Since __sync_single_inode() regains inode_lock before it finally moves
* inode from superblock lists we are OK.
* Put the inode on the super block's dirty list.
*
* CAREFUL! We mark it dirty unconditionally, but move it onto the
* dirty list only if it is hashed or if it refers to a blockdev.
* If it was not hashed, it will never be added to the dirty list
* even if it is later hashed, as it will have been marked dirty already.
*
* If `older_than_this' is non-zero then only flush inodes which have a
* flushtime older than *older_than_this.
* In short, make sure you hash any inodes _before_ you start marking
* them dirty.
*
* If `bdi' is non-zero then we will scan the first inode against each
* superblock until we find the matching ones. One group will be the dirty
* inodes against a filesystem. Then when we hit the dummy blockdev superblock,
* sync_sb_inodes will seekout the blockdev which matches `bdi'. Maybe not
* super-efficient but we're about to do a ton of I/O...
* This function *must* be atomic for the I_DIRTY_PAGES case -
* set_page_dirty() is called under spinlock in several places.
*
* Note that for blockdevs, inode->dirtied_when represents the dirtying time of
* the block-special inode (/dev/hda1) itself. And the ->dirtied_when field of
* the kernel-internal blockdev inode represents the dirtying time of the
* blockdev's pages. This is why for I_DIRTY_PAGES we always use
* page->mapping->host, so the page-dirtying time is recorded in the internal
* blockdev inode.
*/
void
writeback_inodes(struct writeback_control *wbc)
void __mark_inode_dirty(struct inode *inode, int flags)
{
struct super_block *sb;
struct super_block *sb = inode->i_sb;
might_sleep();
spin_lock(&sb_lock);
restart:
list_for_each_entry_reverse(sb, &super_blocks, s_list) {
if (sb_has_dirty_inodes(sb)) {
/* we're making our own get_super here */
sb->s_count++;
spin_unlock(&sb_lock);
/*
* If we can't get the readlock, there's no sense in
* waiting around, most of the time the FS is going to
* be unmounted by the time it is released.
*/
if (down_read_trylock(&sb->s_umount)) {
if (sb->s_root)
sync_sb_inodes(sb, wbc);
up_read(&sb->s_umount);
/*
* Don't do this for I_DIRTY_PAGES - that doesn't actually
* dirty the inode itself
*/
if (flags & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) {
if (sb->s_op->dirty_inode)
sb->s_op->dirty_inode(inode);
}
/*
* make sure that changes are seen by all cpus before we test i_state
* -- mikulas
*/
smp_mb();
/* avoid the locking if we can */
if ((inode->i_state & flags) == flags)
return;
if (unlikely(block_dump))
block_dump___mark_inode_dirty(inode);
spin_lock(&inode_lock);
if ((inode->i_state & flags) != flags) {
const int was_dirty = inode->i_state & I_DIRTY;
inode->i_state |= flags;
/*
* If the inode is being synced, just update its dirty state.
* The unlocker will place the inode on the appropriate
* superblock list, based upon its state.
*/
if (inode->i_state & I_SYNC)
goto out;
/*
* Only add valid (hashed) inodes to the superblock's
* dirty list. Add blockdev inodes as well.
*/
if (!S_ISBLK(inode->i_mode)) {
if (hlist_unhashed(&inode->i_hash))
goto out;
}
if (inode->i_state & (I_FREEING|I_CLEAR))
goto out;
/*
* If the inode was already on b_dirty/b_io/b_more_io, don't
* reposition it (that would break b_dirty time-ordering).
*/
if (!was_dirty) {
struct bdi_writeback *wb = &inode_to_bdi(inode)->wb;
struct backing_dev_info *bdi = wb->bdi;
if (bdi_cap_writeback_dirty(bdi) &&
!test_bit(BDI_registered, &bdi->state)) {
WARN_ON(1);
printk(KERN_ERR "bdi-%s not registered\n",
bdi->name);
}
spin_lock(&sb_lock);
if (__put_super_and_need_restart(sb))
goto restart;
inode->dirtied_when = jiffies;
list_move(&inode->i_list, &wb->b_dirty);
}
if (wbc->nr_to_write <= 0)
break;
}
spin_unlock(&sb_lock);
out:
spin_unlock(&inode_lock);
}
EXPORT_SYMBOL(__mark_inode_dirty);
/*
* writeback and wait upon the filesystem's dirty inodes. The caller will
* do this in two passes - one to write, and one to wait.
* Write out a superblock's list of dirty inodes. A wait will be performed
* upon no inodes, all inodes or the final one, depending upon sync_mode.
*
* If older_than_this is non-NULL, then only write out inodes which
* had their first dirtying at a time earlier than *older_than_this.
*
* A finite limit is set on the number of pages which will be written.
* To prevent infinite livelock of sys_sync().
* If we're a pdlfush thread, then implement pdflush collision avoidance
* against the entire list.
*
* We add in the number of potentially dirty inodes, because each inode write
* can dirty pagecache in the underlying blockdev.
* If `bdi' is non-zero then we're being asked to writeback a specific queue.
* This function assumes that the blockdev superblock's inodes are backed by
* a variety of queues, so all inodes are searched. For other superblocks,
* assume that all inodes are backed by the same queue.
*
* The inodes to be written are parked on bdi->b_io. They are moved back onto
* bdi->b_dirty as they are selected for writing. This way, none can be missed
* on the writer throttling path, and we get decent balancing between many
* throttled threads: we don't want them all piling up on inode_sync_wait.
*/
void sync_inodes_sb(struct super_block *sb, int wait)
static void wait_sb_inodes(struct writeback_control *wbc)
{
struct inode *inode, *old_inode = NULL;
/*
* We need to be protected against the filesystem going from
* r/o to r/w or vice versa.
*/
WARN_ON(!rwsem_is_locked(&wbc->sb->s_umount));
spin_lock(&inode_lock);
/*
* Data integrity sync. Must wait for all pages under writeback,
* because there may have been pages dirtied before our sync
* call, but which had writeout started before we write it out.
* In which case, the inode may not be on the dirty list, but
* we still have to wait for that writeout.
*/
list_for_each_entry(inode, &wbc->sb->s_inodes, i_sb_list) {
struct address_space *mapping;
if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE|I_NEW))
continue;
mapping = inode->i_mapping;
if (mapping->nrpages == 0)
continue;
__iget(inode);
spin_unlock(&inode_lock);
/*
* We hold a reference to 'inode' so it couldn't have
* been removed from s_inodes list while we dropped the
* inode_lock. We cannot iput the inode now as we can
* be holding the last reference and we cannot iput it
* under inode_lock. So we keep the reference and iput
* it later.
*/
iput(old_inode);
old_inode = inode;
filemap_fdatawait(mapping);
cond_resched();
spin_lock(&inode_lock);
}
spin_unlock(&inode_lock);
iput(old_inode);
}
/**
* writeback_inodes_sb - writeback dirty inodes from given super_block
* @sb: the superblock
*
* Start writeback on some inodes on this super_block. No guarantees are made
* on how many (if any) will be written, and this function does not wait
* for IO completion of submitted IO. The number of pages submitted is
* returned.
*/
long writeback_inodes_sb(struct super_block *sb)
{
struct writeback_control wbc = {
.sync_mode = wait ? WB_SYNC_ALL : WB_SYNC_NONE,
.sb = sb,
.sync_mode = WB_SYNC_NONE,
.range_start = 0,
.range_end = LLONG_MAX,
};
unsigned long nr_dirty = global_page_state(NR_FILE_DIRTY);
unsigned long nr_unstable = global_page_state(NR_UNSTABLE_NFS);
long nr_to_write;
if (!wait) {
unsigned long nr_dirty = global_page_state(NR_FILE_DIRTY);
unsigned long nr_unstable = global_page_state(NR_UNSTABLE_NFS);
wbc.nr_to_write = nr_dirty + nr_unstable +
nr_to_write = nr_dirty + nr_unstable +
(inodes_stat.nr_inodes - inodes_stat.nr_unused);
} else
wbc.nr_to_write = LONG_MAX; /* doesn't actually matter */
sync_sb_inodes(sb, &wbc);
wbc.nr_to_write = nr_to_write;
bdi_writeback_all(&wbc);
return nr_to_write - wbc.nr_to_write;
}
EXPORT_SYMBOL(writeback_inodes_sb);
/**
* sync_inodes_sb - sync sb inode pages
* @sb: the superblock
*
* This function writes and waits on any dirty inode belonging to this
* super_block. The number of pages synced is returned.
*/
long sync_inodes_sb(struct super_block *sb)
{
struct writeback_control wbc = {
.sb = sb,
.sync_mode = WB_SYNC_ALL,
.range_start = 0,
.range_end = LLONG_MAX,
};
long nr_to_write = LONG_MAX; /* doesn't actually matter */
wbc.nr_to_write = nr_to_write;
bdi_writeback_all(&wbc);
wait_sb_inodes(&wbc);
return nr_to_write - wbc.nr_to_write;
}
EXPORT_SYMBOL(sync_inodes_sb);
/**
* write_inode_now - write an inode to disk
......
fs/fuse/inode.c
浏览文件 @ a12e4d30
......@@ -801,6 +801,7 @@ static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
{
int err;
fc->bdi.name = "fuse";
fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
fc->bdi.unplug_io_fn = default_unplug_io_fn;
/* fuse does it's own writeback accounting */
......
fs/hugetlbfs/inode.c
浏览文件 @ a12e4d30
......@@ -44,6 +44,7 @@ static const struct inode_operations hugetlbfs_dir_inode_operations;
static const struct inode_operations hugetlbfs_inode_operations;
static struct backing_dev_info hugetlbfs_backing_dev_info = {
.name = "hugetlbfs",
.ra_pages = 0, /* No readahead */
.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
};
......
fs/nfs/client.c
浏览文件 @ a12e4d30
......@@ -879,6 +879,7 @@ static void nfs_server_set_fsinfo(struct nfs_server *server, struct nfs_fsinfo *
server->rsize = NFS_MAX_FILE_IO_SIZE;
server->rpages = (server->rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
server->backing_dev_info.name = "nfs";
server->backing_dev_info.ra_pages = server->rpages * NFS_MAX_READAHEAD;
if (server->wsize > max_rpc_payload)
......
fs/ocfs2/dlm/dlmfs.c
浏览文件 @ a12e4d30
......@@ -325,6 +325,7 @@ static void dlmfs_clear_inode(struct inode *inode)
}
static struct backing_dev_info dlmfs_backing_dev_info = {
.name = "ocfs2-dlmfs",
.ra_pages = 0, /* No readahead */
.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
};
......
fs/ramfs/inode.c
浏览文件 @ a12e4d30
......@@ -46,6 +46,7 @@ static const struct super_operations ramfs_ops;
static const struct inode_operations ramfs_dir_inode_operations;
static struct backing_dev_info ramfs_backing_dev_info = {
.name = "ramfs",
.ra_pages = 0, /* No readahead */
.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK |
BDI_CAP_MAP_DIRECT | BDI_CAP_MAP_COPY |
......
fs/super.c
浏览文件 @ a12e4d30
......@@ -62,9 +62,6 @@ static struct super_block *alloc_super(struct file_system_type *type)
s = NULL;
goto out;
}
INIT_LIST_HEAD(&s->s_dirty);
INIT_LIST_HEAD(&s->s_io);
INIT_LIST_HEAD(&s->s_more_io);
INIT_LIST_HEAD(&s->s_files);
INIT_LIST_HEAD(&s->s_instances);
INIT_HLIST_HEAD(&s->s_anon);
......@@ -171,7 +168,7 @@ int __put_super_and_need_restart(struct super_block *sb)
* Drops a temporary reference, frees superblock if there's no
* references left.
*/
static void put_super(struct super_block *sb)
void put_super(struct super_block *sb)
{
spin_lock(&sb_lock);
__put_super(sb);
......
fs/sync.c
浏览文件 @ a12e4d30
......@@ -19,20 +19,22 @@
SYNC_FILE_RANGE_WAIT_AFTER)
/*
* Do the filesystem syncing work. For simple filesystems sync_inodes_sb(sb, 0)
* just dirties buffers with inodes so we have to submit IO for these buffers
* via __sync_blockdev(). This also speeds up the wait == 1 case since in that
* case write_inode() functions do sync_dirty_buffer() and thus effectively
* write one block at a time.
* Do the filesystem syncing work. For simple filesystems
* writeback_inodes_sb(sb) just dirties buffers with inodes so we have to
* submit IO for these buffers via __sync_blockdev(). This also speeds up the
* wait == 1 case since in that case write_inode() functions do
* sync_dirty_buffer() and thus effectively write one block at a time.
*/
static int __sync_filesystem(struct super_block *sb, int wait)
{
/* Avoid doing twice syncing and cache pruning for quota sync */
if (!wait)
if (!wait) {
writeout_quota_sb(sb, -1);
else
writeback_inodes_sb(sb);
} else {
sync_quota_sb(sb, -1);
sync_inodes_sb(sb, wait);
sync_inodes_sb(sb);
}
if (sb->s_op->sync_fs)
sb->s_op->sync_fs(sb, wait);
return __sync_blockdev(sb->s_bdev, wait);
......@@ -118,7 +120,7 @@ static void sync_filesystems(int wait)
*/
SYSCALL_DEFINE0(sync)
{
wakeup_pdflush(0);
wakeup_flusher_threads(0);
sync_filesystems(0);
sync_filesystems(1);
if (unlikely(laptop_mode))
......
fs/sysfs/inode.c
浏览文件 @ a12e4d30
......@@ -31,6 +31,7 @@ static const struct address_space_operations sysfs_aops = {
};
static struct backing_dev_info sysfs_backing_dev_info = {
.name = "sysfs",
.ra_pages = 0, /* No readahead */
.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
};
......
fs/ubifs/budget.c
浏览文件 @ a12e4d30
......@@ -65,26 +65,14 @@
static int shrink_liability(struct ubifs_info *c, int nr_to_write)
{
int nr_written;
struct writeback_control wbc = {
.sync_mode = WB_SYNC_NONE,
.range_end = LLONG_MAX,
.nr_to_write = nr_to_write,
};
generic_sync_sb_inodes(c->vfs_sb, &wbc);
nr_written = nr_to_write - wbc.nr_to_write;
nr_written = writeback_inodes_sb(c->vfs_sb);
if (!nr_written) {
/*
* Re-try again but wait on pages/inodes which are being
* written-back concurrently (e.g., by pdflush).
*/
memset(&wbc, 0, sizeof(struct writeback_control));
wbc.sync_mode = WB_SYNC_ALL;
wbc.range_end = LLONG_MAX;
wbc.nr_to_write = nr_to_write;
generic_sync_sb_inodes(c->vfs_sb, &wbc);
nr_written = nr_to_write - wbc.nr_to_write;
nr_written = sync_inodes_sb(c->vfs_sb);
}
dbg_budg("%d pages were written back", nr_written);
......
fs/ubifs/super.c
浏览文件 @ a12e4d30
......@@ -438,12 +438,6 @@ static int ubifs_sync_fs(struct super_block *sb, int wait)
{
int i, err;
struct ubifs_info *c = sb->s_fs_info;
struct writeback_control wbc = {
.sync_mode = WB_SYNC_ALL,
.range_start = 0,
.range_end = LLONG_MAX,
.nr_to_write = LONG_MAX,
};
/*
* Zero @wait is just an advisory thing to help the file system shove
......@@ -462,7 +456,7 @@ static int ubifs_sync_fs(struct super_block *sb, int wait)
* the user be able to get more accurate results of 'statfs()' after
* they synchronize the file system.
*/
generic_sync_sb_inodes(sb, &wbc);
sync_inodes_sb(sb);
/*
* Synchronize write buffers, because 'ubifs_run_commit()' does not
......@@ -1971,6 +1965,7 @@ static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
*
* Read-ahead will be disabled because @c->bdi.ra_pages is 0.
*/
c->bdi.name = "ubifs",
c->bdi.capabilities = BDI_CAP_MAP_COPY;
c->bdi.unplug_io_fn = default_unplug_io_fn;
err = bdi_init(&c->bdi);
......
include/linux/backing-dev.h
浏览文件 @ a12e4d30
......@@ -13,6 +13,8 @@
#include <linux/proportions.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/writeback.h>
#include <asm/atomic.h>
struct page;
......@@ -23,9 +25,11 @@ struct dentry;
* Bits in backing_dev_info.state
*/
enum bdi_state {
BDI_pdflush, /* A pdflush thread is working this device */
BDI_pending, /* On its way to being activated */
BDI_wb_alloc, /* Default embedded wb allocated */
BDI_async_congested, /* The async (write) queue is getting full */
BDI_sync_congested, /* The sync queue is getting full */
BDI_registered, /* bdi_register() was done */
BDI_unused, /* Available bits start here */
};
......@@ -39,7 +43,22 @@ enum bdi_stat_item {
#define BDI_STAT_BATCH (8*(1+ilog2(nr_cpu_ids)))
struct bdi_writeback {
struct list_head list; /* hangs off the bdi */
struct backing_dev_info *bdi; /* our parent bdi */
unsigned int nr;
unsigned long last_old_flush; /* last old data flush */
struct task_struct *task; /* writeback task */
struct list_head b_dirty; /* dirty inodes */
struct list_head b_io; /* parked for writeback */
struct list_head b_more_io; /* parked for more writeback */
};
struct backing_dev_info {
struct list_head bdi_list;
unsigned long ra_pages; /* max readahead in PAGE_CACHE_SIZE units */
unsigned long state; /* Always use atomic bitops on this */
unsigned int capabilities; /* Device capabilities */
......@@ -48,6 +67,8 @@ struct backing_dev_info {
void (*unplug_io_fn)(struct backing_dev_info *, struct page *);
void *unplug_io_data;
char *name;
struct percpu_counter bdi_stat[NR_BDI_STAT_ITEMS];
struct prop_local_percpu completions;
......@@ -56,6 +77,14 @@ struct backing_dev_info {
unsigned int min_ratio;
unsigned int max_ratio, max_prop_frac;
struct bdi_writeback wb; /* default writeback info for this bdi */
spinlock_t wb_lock; /* protects update side of wb_list */
struct list_head wb_list; /* the flusher threads hanging off this bdi */
unsigned long wb_mask; /* bitmask of registered tasks */
unsigned int wb_cnt; /* number of registered tasks */
struct list_head work_list;
struct device *dev;
#ifdef CONFIG_DEBUG_FS
......@@ -71,6 +100,19 @@ int bdi_register(struct backing_dev_info *bdi, struct device *parent,
const char *fmt, ...);
int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev);
void bdi_unregister(struct backing_dev_info *bdi);
void bdi_start_writeback(struct writeback_control *wbc);
int bdi_writeback_task(struct bdi_writeback *wb);
int bdi_has_dirty_io(struct backing_dev_info *bdi);
extern spinlock_t bdi_lock;
extern struct list_head bdi_list;
static inline int wb_has_dirty_io(struct bdi_writeback *wb)
{
return !list_empty(&wb->b_dirty) ||
!list_empty(&wb->b_io) ||
!list_empty(&wb->b_more_io);
}
static inline void __add_bdi_stat(struct backing_dev_info *bdi,
enum bdi_stat_item item, s64 amount)
......@@ -261,6 +303,11 @@ static inline bool bdi_cap_swap_backed(struct backing_dev_info *bdi)
return bdi->capabilities & BDI_CAP_SWAP_BACKED;
}
static inline bool bdi_cap_flush_forker(struct backing_dev_info *bdi)
{
return bdi == &default_backing_dev_info;
}
static inline bool mapping_cap_writeback_dirty(struct address_space *mapping)
{
return bdi_cap_writeback_dirty(mapping->backing_dev_info);
......@@ -276,4 +323,10 @@ static inline bool mapping_cap_swap_backed(struct address_space *mapping)
return bdi_cap_swap_backed(mapping->backing_dev_info);
}
static inline int bdi_sched_wait(void *word)
{
schedule();
return 0;
}
#endif /* _LINUX_BACKING_DEV_H */
include/linux/fs.h
浏览文件 @ a12e4d30
......@@ -715,7 +715,7 @@ struct posix_acl;
struct inode {
struct hlist_node i_hash;
struct list_head i_list;
struct list_head i_list; /* backing dev IO list */
struct list_head i_sb_list;
struct list_head i_dentry;
unsigned long i_ino;
......@@ -1336,9 +1336,6 @@ struct super_block {
struct xattr_handler **s_xattr;
struct list_head s_inodes; /* all inodes */
struct list_head s_dirty; /* dirty inodes */
struct list_head s_io; /* parked for writeback */
struct list_head s_more_io; /* parked for more writeback */
struct hlist_head s_anon; /* anonymous dentries for (nfs) exporting */
struct list_head s_files;
/* s_dentry_lru and s_nr_dentry_unused are protected by dcache_lock */
......@@ -1789,6 +1786,7 @@ extern int get_sb_pseudo(struct file_system_type *, char *,
struct vfsmount *mnt);
extern void simple_set_mnt(struct vfsmount *mnt, struct super_block *sb);
int __put_super_and_need_restart(struct super_block *sb);
void put_super(struct super_block *sb);
/* Alas, no aliases. Too much hassle with bringing module.h everywhere */
#define fops_get(fops) \
......@@ -2071,8 +2069,6 @@ static inline void invalidate_remote_inode(struct inode *inode)
extern int invalidate_inode_pages2(struct address_space *mapping);
extern int invalidate_inode_pages2_range(struct address_space *mapping,
pgoff_t start, pgoff_t end);
extern void generic_sync_sb_inodes(struct super_block *sb,
struct writeback_control *wbc);
extern int write_inode_now(struct inode *, int);
extern int filemap_fdatawrite(struct address_space *);
extern int filemap_flush(struct address_space *);
......@@ -2187,7 +2183,6 @@ extern int bdev_read_only(struct block_device *);
extern int set_blocksize(struct block_device *, int);
extern int sb_set_blocksize(struct super_block *, int);
extern int sb_min_blocksize(struct super_block *, int);
extern int sb_has_dirty_inodes(struct super_block *);
extern int generic_file_mmap(struct file *, struct vm_area_struct *);
extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *);
......
include/linux/writeback.h
浏览文件 @ a12e4d30
......@@ -13,17 +13,6 @@ extern spinlock_t inode_lock;
extern struct list_head inode_in_use;
extern struct list_head inode_unused;
/*
* Yes, writeback.h requires sched.h
* No, sched.h is not included from here.
*/
static inline int task_is_pdflush(struct task_struct *task)
{
return task->flags & PF_FLUSHER;
}
#define current_is_pdflush() task_is_pdflush(current)
/*
* fs/fs-writeback.c
*/
......@@ -40,6 +29,8 @@ enum writeback_sync_modes {
struct writeback_control {
struct backing_dev_info *bdi; /* If !NULL, only write back this
queue */
struct super_block *sb; /* if !NULL, only write inodes from
this super_block */
enum writeback_sync_modes sync_mode;
unsigned long *older_than_this; /* If !NULL, only write back inodes
older than this */
......@@ -76,9 +67,13 @@ struct writeback_control {
/*
* fs/fs-writeback.c
*/
void writeback_inodes(struct writeback_control *wbc);
struct bdi_writeback;
int inode_wait(void *);
void sync_inodes_sb(struct super_block *, int wait);
long writeback_inodes_sb(struct super_block *);
long sync_inodes_sb(struct super_block *);
void writeback_inodes_wbc(struct writeback_control *wbc);
long wb_do_writeback(struct bdi_writeback *wb, int force_wait);
void wakeup_flusher_threads(long nr_pages);
/* writeback.h requires fs.h; it, too, is not included from here. */
static inline void wait_on_inode(struct inode *inode)
......@@ -98,7 +93,6 @@ static inline void inode_sync_wait(struct inode *inode)
/*
* mm/page-writeback.c
*/
int wakeup_pdflush(long nr_pages);
void laptop_io_completion(void);
void laptop_sync_completion(void);
void throttle_vm_writeout(gfp_t gfp_mask);
......@@ -150,7 +144,6 @@ balance_dirty_pages_ratelimited(struct address_space *mapping)
typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc,
void *data);
int pdflush_operation(void (*fn)(unsigned long), unsigned long arg0);
int generic_writepages(struct address_space *mapping,
struct writeback_control *wbc);
int write_cache_pages(struct address_space *mapping,
......
kernel/cgroup.c
浏览文件 @ a12e4d30
......@@ -600,6 +600,7 @@ static struct inode_operations cgroup_dir_inode_operations;
static struct file_operations proc_cgroupstats_operations;
static struct backing_dev_info cgroup_backing_dev_info = {
.name = "cgroup",
.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
};
......
mm/Makefile
浏览文件 @ a12e4d30
......@@ -8,7 +8,7 @@ mmu-$(CONFIG_MMU) := fremap.o highmem.o madvise.o memory.o mincore.o \
vmalloc.o
obj-y := bootmem.o filemap.o mempool.o oom_kill.o fadvise.o \
maccess.o page_alloc.o page-writeback.o pdflush.o \
maccess.o page_alloc.o page-writeback.o \
readahead.o swap.o truncate.o vmscan.o shmem.o \
prio_tree.o util.o mmzone.o vmstat.o backing-dev.o \
page_isolation.o mm_init.o $(mmu-y)
......
mm/backing-dev.c
浏览文件 @ a12e4d30
#include <linux/wait.h>
#include <linux/backing-dev.h>
#include <linux/kthread.h>
#include <linux/freezer.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/writeback.h>
......@@ -14,6 +17,7 @@ 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,
......@@ -22,6 +26,18 @@ struct backing_dev_info default_backing_dev_info = {
EXPORT_SYMBOL_GPL(default_backing_dev_info);
static struct class *bdi_class;
DEFINE_SPINLOCK(bdi_lock);
LIST_HEAD(bdi_list);
LIST_HEAD(bdi_pending_list);
static struct task_struct *sync_supers_tsk;
static struct timer_list sync_supers_timer;
static int bdi_sync_supers(void *);
static void sync_supers_timer_fn(unsigned long);
static void arm_supers_timer(void);
static void bdi_add_default_flusher_task(struct backing_dev_info *bdi);
#ifdef CONFIG_DEBUG_FS
#include <linux/debugfs.h>
......@@ -37,9 +53,29 @@ static void bdi_debug_init(void)
static int bdi_debug_stats_show(struct seq_file *m, void *v)
{
struct backing_dev_info *bdi = m->private;
struct bdi_writeback *wb;
unsigned long background_thresh;
unsigned long dirty_thresh;
unsigned long bdi_thresh;
unsigned long nr_dirty, nr_io, nr_more_io, nr_wb;
struct inode *inode;
/*
* inode lock is enough here, the bdi->wb_list is protected by
* RCU on the reader side
*/
nr_wb = nr_dirty = nr_io = nr_more_io = 0;
spin_lock(&inode_lock);
list_for_each_entry(wb, &bdi->wb_list, list) {
nr_wb++;
list_for_each_entry(inode, &wb->b_dirty, i_list)
nr_dirty++;
list_for_each_entry(inode, &wb->b_io, i_list)
nr_io++;
list_for_each_entry(inode, &wb->b_more_io, i_list)
nr_more_io++;
}
spin_unlock(&inode_lock);
get_dirty_limits(&background_thresh, &dirty_thresh, &bdi_thresh, bdi);
......@@ -49,12 +85,22 @@ static int bdi_debug_stats_show(struct seq_file *m, void *v)
"BdiReclaimable: %8lu kB\n"
"BdiDirtyThresh: %8lu kB\n"
"DirtyThresh: %8lu kB\n"
"BackgroundThresh: %8lu kB\n",
"BackgroundThresh: %8lu kB\n"
"WriteBack threads:%8lu\n"
"b_dirty: %8lu\n"
"b_io: %8lu\n"
"b_more_io: %8lu\n"
"bdi_list: %8u\n"
"state: %8lx\n"
"wb_mask: %8lx\n"
"wb_list: %8u\n"
"wb_cnt: %8u\n",
(unsigned long) K(bdi_stat(bdi, BDI_WRITEBACK)),
(unsigned long) K(bdi_stat(bdi, BDI_RECLAIMABLE)),
K(bdi_thresh),
K(dirty_thresh),
K(background_thresh));
K(bdi_thresh), K(dirty_thresh),
K(background_thresh), nr_wb, nr_dirty, nr_io, nr_more_io,
!list_empty(&bdi->bdi_list), bdi->state, bdi->wb_mask,
!list_empty(&bdi->wb_list), bdi->wb_cnt);
#undef K
return 0;
......@@ -185,6 +231,13 @@ static int __init default_bdi_init(void)
{
int err;
sync_supers_tsk = kthread_run(bdi_sync_supers, NULL, "sync_supers");
BUG_ON(IS_ERR(sync_supers_tsk));
init_timer(&sync_supers_timer);
setup_timer(&sync_supers_timer, sync_supers_timer_fn, 0);
arm_supers_timer();
err = bdi_init(&default_backing_dev_info);
if (!err)
bdi_register(&default_backing_dev_info, NULL, "default");
......@@ -193,6 +246,248 @@ static int __init default_bdi_init(void)
}
subsys_initcall(default_bdi_init);
static void bdi_wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi)
{
memset(wb, 0, sizeof(*wb));
wb->bdi = bdi;
wb->last_old_flush = jiffies;
INIT_LIST_HEAD(&wb->b_dirty);
INIT_LIST_HEAD(&wb->b_io);
INIT_LIST_HEAD(&wb->b_more_io);
}
static void bdi_task_init(struct backing_dev_info *bdi,
struct bdi_writeback *wb)
{
struct task_struct *tsk = current;
spin_lock(&bdi->wb_lock);
list_add_tail_rcu(&wb->list, &bdi->wb_list);
spin_unlock(&bdi->wb_lock);
tsk->flags |= PF_FLUSHER | PF_SWAPWRITE;
set_freezable();
/*
* Our parent may run at a different priority, just set us to normal
*/
set_user_nice(tsk, 0);
}
static int bdi_start_fn(void *ptr)
{
struct bdi_writeback *wb = ptr;
struct backing_dev_info *bdi = wb->bdi;
int ret;
/*
* Add us to the active bdi_list
*/
spin_lock(&bdi_lock);
list_add(&bdi->bdi_list, &bdi_list);
spin_unlock(&bdi_lock);
bdi_task_init(bdi, wb);
/*
* Clear pending bit and wakeup anybody waiting to tear us down
*/
clear_bit(BDI_pending, &bdi->state);
smp_mb__after_clear_bit();
wake_up_bit(&bdi->state, BDI_pending);
ret = bdi_writeback_task(wb);
/*
* Remove us from the list
*/
spin_lock(&bdi->wb_lock);
list_del_rcu(&wb->list);
spin_unlock(&bdi->wb_lock);
/*
* Flush any work that raced with us exiting. No new work
* will be added, since this bdi isn't discoverable anymore.
*/
if (!list_empty(&bdi->work_list))
wb_do_writeback(wb, 1);
wb->task = NULL;
return ret;
}
int bdi_has_dirty_io(struct backing_dev_info *bdi)
{
return wb_has_dirty_io(&bdi->wb);
}
static void bdi_flush_io(struct backing_dev_info *bdi)
{
struct writeback_control wbc = {
.bdi = bdi,
.sync_mode = WB_SYNC_NONE,
.older_than_this = NULL,
.range_cyclic = 1,
.nr_to_write = 1024,
};
writeback_inodes_wbc(&wbc);
}
/*
* kupdated() used to do this. We cannot do it from the bdi_forker_task()
* or we risk deadlocking on ->s_umount. The longer term solution would be
* to implement sync_supers_bdi() or similar and simply do it from the
* bdi writeback tasks individually.
*/
static int bdi_sync_supers(void *unused)
{
set_user_nice(current, 0);
while (!kthread_should_stop()) {
set_current_state(TASK_INTERRUPTIBLE);
schedule();
/*
* Do this periodically, like kupdated() did before.
*/
sync_supers();
}
return 0;
}
static void arm_supers_timer(void)
{
unsigned long next;
next = msecs_to_jiffies(dirty_writeback_interval * 10) + jiffies;
mod_timer(&sync_supers_timer, round_jiffies_up(next));
}
static void sync_supers_timer_fn(unsigned long unused)
{
wake_up_process(sync_supers_tsk);
arm_supers_timer();
}
static int bdi_forker_task(void *ptr)
{
struct bdi_writeback *me = ptr;
bdi_task_init(me->bdi, me);
for (;;) {
struct backing_dev_info *bdi, *tmp;
struct bdi_writeback *wb;
/*
* Temporary measure, we want to make sure we don't see
* dirty data on the default backing_dev_info
*/
if (wb_has_dirty_io(me) || !list_empty(&me->bdi->work_list))
wb_do_writeback(me, 0);
spin_lock(&bdi_lock);
/*
* Check if any existing bdi's have dirty data without
* a thread registered. If so, set that up.
*/
list_for_each_entry_safe(bdi, tmp, &bdi_list, bdi_list) {
if (bdi->wb.task)
continue;
if (list_empty(&bdi->work_list) &&
!bdi_has_dirty_io(bdi))
continue;
bdi_add_default_flusher_task(bdi);
}
set_current_state(TASK_INTERRUPTIBLE);
if (list_empty(&bdi_pending_list)) {
unsigned long wait;
spin_unlock(&bdi_lock);
wait = msecs_to_jiffies(dirty_writeback_interval * 10);
schedule_timeout(wait);
try_to_freeze();
continue;
}
__set_current_state(TASK_RUNNING);
/*
* This is our real job - check for pending entries in
* bdi_pending_list, and create the tasks that got added
*/
bdi = list_entry(bdi_pending_list.next, struct backing_dev_info,
bdi_list);
list_del_init(&bdi->bdi_list);
spin_unlock(&bdi_lock);
wb = &bdi->wb;
wb->task = kthread_run(bdi_start_fn, wb, "flush-%s",
dev_name(bdi->dev));
/*
* If task creation fails, then readd the bdi to
* the pending list and force writeout of the bdi
* from this forker thread. That will free some memory
* and we can try again.
*/
if (IS_ERR(wb->task)) {
wb->task = NULL;
/*
* Add this 'bdi' to the back, so we get
* a chance to flush other bdi's to free
* memory.
*/
spin_lock(&bdi_lock);
list_add_tail(&bdi->bdi_list, &bdi_pending_list);
spin_unlock(&bdi_lock);
bdi_flush_io(bdi);
}
}
return 0;
}
/*
* Add the default flusher task that gets created for any bdi
* that has dirty data pending writeout
*/
void static bdi_add_default_flusher_task(struct backing_dev_info *bdi)
{
if (!bdi_cap_writeback_dirty(bdi))
return;
if (WARN_ON(!test_bit(BDI_registered, &bdi->state))) {
printk(KERN_ERR "bdi %p/%s is not registered!\n",
bdi, bdi->name);
return;
}
/*
* Check with the helper whether to proceed adding a task. Will only
* abort if we two or more simultanous calls to
* bdi_add_default_flusher_task() occured, further additions will block
* waiting for previous additions to finish.
*/
if (!test_and_set_bit(BDI_pending, &bdi->state)) {
list_move_tail(&bdi->bdi_list, &bdi_pending_list);
/*
* We are now on the pending list, wake up bdi_forker_task()
* to finish the job and add us back to the active bdi_list
*/
wake_up_process(default_backing_dev_info.wb.task);
}
}
int bdi_register(struct backing_dev_info *bdi, struct device *parent,
const char *fmt, ...)
{
......@@ -211,9 +506,35 @@ int bdi_register(struct backing_dev_info *bdi, struct device *parent,
goto exit;
}
spin_lock(&bdi_lock);
list_add_tail(&bdi->bdi_list, &bdi_list);
spin_unlock(&bdi_lock);
bdi->dev = dev;
bdi_debug_register(bdi, dev_name(dev));
/*
* Just start the forker thread for our default backing_dev_info,
* and add other bdi's to the list. They will get a thread created
* on-demand when they need it.
*/
if (bdi_cap_flush_forker(bdi)) {
struct bdi_writeback *wb = &bdi->wb;
wb->task = kthread_run(bdi_forker_task, wb, "bdi-%s",
dev_name(dev));
if (IS_ERR(wb->task)) {
wb->task = NULL;
ret = -ENOMEM;
spin_lock(&bdi_lock);
list_del(&bdi->bdi_list);
spin_unlock(&bdi_lock);
goto exit;
}
}
bdi_debug_register(bdi, dev_name(dev));
set_bit(BDI_registered, &bdi->state);
exit:
return ret;
}
......@@ -225,9 +546,42 @@ int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev)
}
EXPORT_SYMBOL(bdi_register_dev);
/*
* Remove bdi from the global list and shutdown any threads we have running
*/
static void bdi_wb_shutdown(struct backing_dev_info *bdi)
{
struct bdi_writeback *wb;
if (!bdi_cap_writeback_dirty(bdi))
return;
/*
* If setup is pending, wait for that to complete first
*/
wait_on_bit(&bdi->state, BDI_pending, bdi_sched_wait,
TASK_UNINTERRUPTIBLE);
/*
* Make sure nobody finds us on the bdi_list anymore
*/
spin_lock(&bdi_lock);
list_del(&bdi->bdi_list);
spin_unlock(&bdi_lock);
/*
* Finally, kill the kernel threads. We don't need to be RCU
* safe anymore, since the bdi is gone from visibility.
*/
list_for_each_entry(wb, &bdi->wb_list, list)
kthread_stop(wb->task);
}
void bdi_unregister(struct backing_dev_info *bdi)
{
if (bdi->dev) {
if (!bdi_cap_flush_forker(bdi))
bdi_wb_shutdown(bdi);
bdi_debug_unregister(bdi);
device_unregister(bdi->dev);
bdi->dev = NULL;
......@@ -237,14 +591,25 @@ EXPORT_SYMBOL(bdi_unregister);
int bdi_init(struct backing_dev_info *bdi)
{
int i;
int err;
int i, err;
bdi->dev = NULL;
bdi->min_ratio = 0;
bdi->max_ratio = 100;
bdi->max_prop_frac = PROP_FRAC_BASE;
spin_lock_init(&bdi->wb_lock);
INIT_LIST_HEAD(&bdi->bdi_list);
INIT_LIST_HEAD(&bdi->wb_list);
INIT_LIST_HEAD(&bdi->work_list);
bdi_wb_init(&bdi->wb, bdi);
/*
* Just one thread support for now, hard code mask and count
*/
bdi->wb_mask = 1;
bdi->wb_cnt = 1;
for (i = 0; i < NR_BDI_STAT_ITEMS; i++) {
err = percpu_counter_init(&bdi->bdi_stat[i], 0);
......@@ -269,6 +634,8 @@ void bdi_destroy(struct backing_dev_info *bdi)
{
int i;
WARN_ON(bdi_has_dirty_io(bdi));
bdi_unregister(bdi);
for (i = 0; i < NR_BDI_STAT_ITEMS; i++)
......
mm/page-writeback.c
浏览文件 @ a12e4d30
......@@ -35,15 +35,6 @@
#include <linux/buffer_head.h>
#include <linux/pagevec.h>
/*
* The maximum number of pages to writeout in a single bdflush/kupdate
* operation. We do this so we don't hold I_SYNC against an inode for
* enormous amounts of time, which would block a userspace task which has
* been forced to throttle against that inode. Also, the code reevaluates
* the dirty each time it has written this many pages.
*/
#define MAX_WRITEBACK_PAGES 1024
/*
* After a CPU has dirtied this many pages, balance_dirty_pages_ratelimited
* will look to see if it needs to force writeback or throttling.
......@@ -117,8 +108,6 @@ EXPORT_SYMBOL(laptop_mode);
/* End of sysctl-exported parameters */
static void background_writeout(unsigned long _min_pages);
/*
* Scale the writeback cache size proportional to the relative writeout speeds.
*
......@@ -320,15 +309,13 @@ static void task_dirty_limit(struct task_struct *tsk, unsigned long *pdirty)
/*
*
*/
static DEFINE_SPINLOCK(bdi_lock);
static unsigned int bdi_min_ratio;
int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio)
{
int ret = 0;
unsigned long flags;
spin_lock_irqsave(&bdi_lock, flags);
spin_lock(&bdi_lock);
if (min_ratio > bdi->max_ratio) {
ret = -EINVAL;
} else {
......@@ -340,27 +327,26 @@ int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio)
ret = -EINVAL;
}
}
spin_unlock_irqrestore(&bdi_lock, flags);
spin_unlock(&bdi_lock);
return ret;
}
int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned max_ratio)
{
unsigned long flags;
int ret = 0;
if (max_ratio > 100)
return -EINVAL;
spin_lock_irqsave(&bdi_lock, flags);
spin_lock(&bdi_lock);
if (bdi->min_ratio > max_ratio) {
ret = -EINVAL;
} else {
bdi->max_ratio = max_ratio;
bdi->max_prop_frac = (PROP_FRAC_BASE * max_ratio) / 100;
}
spin_unlock_irqrestore(&bdi_lock, flags);
spin_unlock(&bdi_lock);
return ret;
}
......@@ -546,7 +532,7 @@ static void balance_dirty_pages(struct address_space *mapping)
* up.
*/
if (bdi_nr_reclaimable > bdi_thresh) {
writeback_inodes(&wbc);
writeback_inodes_wbc(&wbc);
pages_written += write_chunk - wbc.nr_to_write;
get_dirty_limits(&background_thresh, &dirty_thresh,
&bdi_thresh, bdi);
......@@ -575,7 +561,7 @@ static void balance_dirty_pages(struct address_space *mapping)
if (pages_written >= write_chunk)
break; /* We've done our duty */
congestion_wait(BLK_RW_ASYNC, HZ/10);
schedule_timeout(1);
}
if (bdi_nr_reclaimable + bdi_nr_writeback < bdi_thresh &&
......@@ -594,10 +580,18 @@ static void balance_dirty_pages(struct address_space *mapping)
* background_thresh, to keep the amount of dirty memory low.
*/
if ((laptop_mode && pages_written) ||
(!laptop_mode && (global_page_state(NR_FILE_DIRTY)
+ global_page_state(NR_UNSTABLE_NFS)
> background_thresh)))
pdflush_operation(background_writeout, 0);
(!laptop_mode && ((nr_writeback = global_page_state(NR_FILE_DIRTY)
+ global_page_state(NR_UNSTABLE_NFS))
> background_thresh))) {
struct writeback_control wbc = {
.bdi = bdi,
.sync_mode = WB_SYNC_NONE,
.nr_to_write = nr_writeback,
};
bdi_start_writeback(&wbc);
}
}
void set_page_dirty_balance(struct page *page, int page_mkwrite)
......@@ -681,124 +675,10 @@ void throttle_vm_writeout(gfp_t gfp_mask)
}
}
/*
* writeback at least _min_pages, and keep writing until the amount of dirty
* memory is less than the background threshold, or until we're all clean.
*/
static void background_writeout(unsigned long _min_pages)
{
long min_pages = _min_pages;
struct writeback_control wbc = {
.bdi = NULL,
.sync_mode = WB_SYNC_NONE,
.older_than_this = NULL,
.nr_to_write = 0,
.nonblocking = 1,
.range_cyclic = 1,
};
for ( ; ; ) {
unsigned long background_thresh;
unsigned long dirty_thresh;
get_dirty_limits(&background_thresh, &dirty_thresh, NULL, NULL);
if (global_page_state(NR_FILE_DIRTY) +
global_page_state(NR_UNSTABLE_NFS) < background_thresh
&& min_pages <= 0)
break;
wbc.more_io = 0;
wbc.encountered_congestion = 0;
wbc.nr_to_write = MAX_WRITEBACK_PAGES;
wbc.pages_skipped = 0;
writeback_inodes(&wbc);
min_pages -= MAX_WRITEBACK_PAGES - wbc.nr_to_write;
if (wbc.nr_to_write > 0 || wbc.pages_skipped > 0) {
/* Wrote less than expected */
if (wbc.encountered_congestion || wbc.more_io)
congestion_wait(BLK_RW_ASYNC, HZ/10);
else
break;
}
}
}
/*
* Start writeback of `nr_pages' pages. If `nr_pages' is zero, write back
* the whole world. Returns 0 if a pdflush thread was dispatched. Returns
* -1 if all pdflush threads were busy.
*/
int wakeup_pdflush(long nr_pages)
{
if (nr_pages == 0)
nr_pages = global_page_state(NR_FILE_DIRTY) +
global_page_state(NR_UNSTABLE_NFS);
return pdflush_operation(background_writeout, nr_pages);
}
static void wb_timer_fn(unsigned long unused);
static void laptop_timer_fn(unsigned long unused);
static DEFINE_TIMER(wb_timer, wb_timer_fn, 0, 0);
static DEFINE_TIMER(laptop_mode_wb_timer, laptop_timer_fn, 0, 0);
/*
* Periodic writeback of "old" data.
*
* Define "old": the first time one of an inode's pages is dirtied, we mark the
* dirtying-time in the inode's address_space. So this periodic writeback code
* just walks the superblock inode list, writing back any inodes which are
* older than a specific point in time.
*
* Try to run once per dirty_writeback_interval. But if a writeback event
* takes longer than a dirty_writeback_interval interval, then leave a
* one-second gap.
*
* older_than_this takes precedence over nr_to_write. So we'll only write back
* all dirty pages if they are all attached to "old" mappings.
*/
static void wb_kupdate(unsigned long arg)
{
unsigned long oldest_jif;
unsigned long start_jif;
unsigned long next_jif;
long nr_to_write;
struct writeback_control wbc = {
.bdi = NULL,
.sync_mode = WB_SYNC_NONE,
.older_than_this = &oldest_jif,
.nr_to_write = 0,
.nonblocking = 1,
.for_kupdate = 1,
.range_cyclic = 1,
};
sync_supers();
oldest_jif = jiffies - msecs_to_jiffies(dirty_expire_interval * 10);
start_jif = jiffies;
next_jif = start_jif + msecs_to_jiffies(dirty_writeback_interval * 10);
nr_to_write = global_page_state(NR_FILE_DIRTY) +
global_page_state(NR_UNSTABLE_NFS) +
(inodes_stat.nr_inodes - inodes_stat.nr_unused);
while (nr_to_write > 0) {
wbc.more_io = 0;
wbc.encountered_congestion = 0;
wbc.nr_to_write = MAX_WRITEBACK_PAGES;
writeback_inodes(&wbc);
if (wbc.nr_to_write > 0) {
if (wbc.encountered_congestion || wbc.more_io)
congestion_wait(BLK_RW_ASYNC, HZ/10);
else
break; /* All the old data is written */
}
nr_to_write -= MAX_WRITEBACK_PAGES - wbc.nr_to_write;
}
if (time_before(next_jif, jiffies + HZ))
next_jif = jiffies + HZ;
if (dirty_writeback_interval)
mod_timer(&wb_timer, next_jif);
}
/*
* sysctl handler for /proc/sys/vm/dirty_writeback_centisecs
*/
......@@ -806,28 +686,24 @@ int dirty_writeback_centisecs_handler(ctl_table *table, int write,
struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
{
proc_dointvec(table, write, file, buffer, length, ppos);
if (dirty_writeback_interval)
mod_timer(&wb_timer, jiffies +
msecs_to_jiffies(dirty_writeback_interval * 10));
else
del_timer(&wb_timer);
return 0;
}
static void wb_timer_fn(unsigned long unused)
{
if (pdflush_operation(wb_kupdate, 0) < 0)
mod_timer(&wb_timer, jiffies + HZ); /* delay 1 second */
}
static void laptop_flush(unsigned long unused)
static void do_laptop_sync(struct work_struct *work)
{
sys_sync();
wakeup_flusher_threads(0);
kfree(work);
}
static void laptop_timer_fn(unsigned long unused)
{
pdflush_operation(laptop_flush, 0);
struct work_struct *work;
work = kmalloc(sizeof(*work), GFP_ATOMIC);
if (work) {
INIT_WORK(work, do_laptop_sync);
schedule_work(work);
}
}
/*
......@@ -910,8 +786,6 @@ void __init page_writeback_init(void)
{
int shift;
mod_timer(&wb_timer,
jiffies + msecs_to_jiffies(dirty_writeback_interval * 10));
writeback_set_ratelimit();
register_cpu_notifier(&ratelimit_nb);
......
mm/pdflush.c 已删除 100644 → 0
浏览文件 @ 89af571c
/*
* mm/pdflush.c - worker threads for writing back filesystem data
*
* Copyright (C) 2002, Linus Torvalds.
*
* 09Apr2002 Andrew Morton
* Initial version
* 29Feb2004 kaos@sgi.com
* Move worker thread creation to kthread to avoid chewing
* up stack space with nested calls to kernel_thread.
*/
#include <linux/sched.h>
#include <linux/list.h>
#include <linux/signal.h>
#include <linux/spinlock.h>
#include <linux/gfp.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h> /* Needed by writeback.h */
#include <linux/writeback.h> /* Prototypes pdflush_operation() */
#include <linux/kthread.h>
#include <linux/cpuset.h>
#include <linux/freezer.h>
/*
* Minimum and maximum number of pdflush instances
*/
#define MIN_PDFLUSH_THREADS 2
#define MAX_PDFLUSH_THREADS 8
static void start_one_pdflush_thread(void);
/*
* The pdflush threads are worker threads for writing back dirty data.
* Ideally, we'd like one thread per active disk spindle. But the disk
* topology is very hard to divine at this level. Instead, we take
* care in various places to prevent more than one pdflush thread from
* performing writeback against a single filesystem. pdflush threads
* have the PF_FLUSHER flag set in current->flags to aid in this.
*/
/*
* All the pdflush threads. Protected by pdflush_lock
*/
static LIST_HEAD(pdflush_list);
static DEFINE_SPINLOCK(pdflush_lock);
/*
* The count of currently-running pdflush threads. Protected
* by pdflush_lock.
*
* Readable by sysctl, but not writable. Published to userspace at
* /proc/sys/vm/nr_pdflush_threads.
*/
int nr_pdflush_threads = 0;
/*
* The time at which the pdflush thread pool last went empty
*/
static unsigned long last_empty_jifs;
/*
* The pdflush thread.
*
* Thread pool management algorithm:
*
* - The minimum and maximum number of pdflush instances are bound
* by MIN_PDFLUSH_THREADS and MAX_PDFLUSH_THREADS.
*
* - If there have been no idle pdflush instances for 1 second, create
* a new one.
*
* - If the least-recently-went-to-sleep pdflush thread has been asleep
* for more than one second, terminate a thread.
*/
/*
* A structure for passing work to a pdflush thread. Also for passing
* state information between pdflush threads. Protected by pdflush_lock.
*/
struct pdflush_work {
struct task_struct *who; /* The thread */
void (*fn)(unsigned long); /* A callback function */
unsigned long arg0; /* An argument to the callback */
struct list_head list; /* On pdflush_list, when idle */
unsigned long when_i_went_to_sleep;
};
static int __pdflush(struct pdflush_work *my_work)
{
current->flags |= PF_FLUSHER | PF_SWAPWRITE;
set_freezable();
my_work->fn = NULL;
my_work->who = current;
INIT_LIST_HEAD(&my_work->list);
spin_lock_irq(&pdflush_lock);
for ( ; ; ) {
struct pdflush_work *pdf;
set_current_state(TASK_INTERRUPTIBLE);
list_move(&my_work->list, &pdflush_list);
my_work->when_i_went_to_sleep = jiffies;
spin_unlock_irq(&pdflush_lock);
schedule();
try_to_freeze();
spin_lock_irq(&pdflush_lock);
if (!list_empty(&my_work->list)) {
/*
* Someone woke us up, but without removing our control
* structure from the global list. swsusp will do this
* in try_to_freeze()->refrigerator(). Handle it.
*/
my_work->fn = NULL;
continue;
}
if (my_work->fn == NULL) {
printk("pdflush: bogus wakeup\n");
continue;
}
spin_unlock_irq(&pdflush_lock);
(*my_work->fn)(my_work->arg0);
spin_lock_irq(&pdflush_lock);
/*
* Thread creation: For how long have there been zero
* available threads?
*
* To throttle creation, we reset last_empty_jifs.
*/
if (time_after(jiffies, last_empty_jifs + 1 * HZ)) {
if (list_empty(&pdflush_list)) {
if (nr_pdflush_threads < MAX_PDFLUSH_THREADS) {
last_empty_jifs = jiffies;
nr_pdflush_threads++;
spin_unlock_irq(&pdflush_lock);
start_one_pdflush_thread();
spin_lock_irq(&pdflush_lock);
}
}
}
my_work->fn = NULL;
/*
* Thread destruction: For how long has the sleepiest
* thread slept?
*/
if (list_empty(&pdflush_list))
continue;
if (nr_pdflush_threads <= MIN_PDFLUSH_THREADS)
continue;
pdf = list_entry(pdflush_list.prev, struct pdflush_work, list);
if (time_after(jiffies, pdf->when_i_went_to_sleep + 1 * HZ)) {
/* Limit exit rate */
pdf->when_i_went_to_sleep = jiffies;
break; /* exeunt */
}
}
nr_pdflush_threads--;
spin_unlock_irq(&pdflush_lock);
return 0;
}
/*
* Of course, my_work wants to be just a local in __pdflush(). It is
* separated out in this manner to hopefully prevent the compiler from
* performing unfortunate optimisations against the auto variables. Because
* these are visible to other tasks and CPUs. (No problem has actually
* been observed. This is just paranoia).
*/
static int pdflush(void *dummy)
{
struct pdflush_work my_work;
cpumask_var_t cpus_allowed;
/*
* Since the caller doesn't even check kthread_run() worked, let's not
* freak out too much if this fails.
*/
if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) {
printk(KERN_WARNING "pdflush failed to allocate cpumask\n");
return 0;
}
/*
* pdflush can spend a lot of time doing encryption via dm-crypt. We
* don't want to do that at keventd's priority.
*/
set_user_nice(current, 0);
/*
* Some configs put our parent kthread in a limited cpuset,
* which kthread() overrides, forcing cpus_allowed == cpu_all_mask.
* Our needs are more modest - cut back to our cpusets cpus_allowed.
* This is needed as pdflush's are dynamically created and destroyed.
* The boottime pdflush's are easily placed w/o these 2 lines.
*/
cpuset_cpus_allowed(current, cpus_allowed);
set_cpus_allowed_ptr(current, cpus_allowed);
free_cpumask_var(cpus_allowed);
return __pdflush(&my_work);
}
/*
* Attempt to wake up a pdflush thread, and get it to do some work for you.
* Returns zero if it indeed managed to find a worker thread, and passed your
* payload to it.
*/
int pdflush_operation(void (*fn)(unsigned long), unsigned long arg0)
{
unsigned long flags;
int ret = 0;
BUG_ON(fn == NULL); /* Hard to diagnose if it's deferred */
spin_lock_irqsave(&pdflush_lock, flags);
if (list_empty(&pdflush_list)) {
ret = -1;
} else {
struct pdflush_work *pdf;
pdf = list_entry(pdflush_list.next, struct pdflush_work, list);
list_del_init(&pdf->list);
if (list_empty(&pdflush_list))
last_empty_jifs = jiffies;
pdf->fn = fn;
pdf->arg0 = arg0;
wake_up_process(pdf->who);
}
spin_unlock_irqrestore(&pdflush_lock, flags);
return ret;
}
static void start_one_pdflush_thread(void)
{
struct task_struct *k;
k = kthread_run(pdflush, NULL, "pdflush");
if (unlikely(IS_ERR(k))) {
spin_lock_irq(&pdflush_lock);
nr_pdflush_threads--;
spin_unlock_irq(&pdflush_lock);
}
}
static int __init pdflush_init(void)
{
int i;
/*
* Pre-set nr_pdflush_threads... If we fail to create,
* the count will be decremented.
*/
nr_pdflush_threads = MIN_PDFLUSH_THREADS;
for (i = 0; i < MIN_PDFLUSH_THREADS; i++)
start_one_pdflush_thread();
return 0;
}
module_init(pdflush_init);
mm/swap_state.c
浏览文件 @ a12e4d30
......@@ -34,6 +34,7 @@ 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,
};
......
mm/vmscan.c
浏览文件 @ a12e4d30
......@@ -1720,7 +1720,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
*/
if (total_scanned > sc->swap_cluster_max +
sc->swap_cluster_max / 2) {
wakeup_pdflush(laptop_mode ? 0 : total_scanned);
wakeup_flusher_threads(laptop_mode ? 0 : total_scanned);
sc->may_writepage = 1;
}
......
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