Merge branch 'writeback' of git://git.kernel.dk/linux-2.6-block (a3eb51ec) · Commits · 戴 / test

fs/afs/write.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -712,7 +712,6 @@ int afs_writeback_all(struct afs_vnode *vnode)
		.bdi = mapping->backing_dev_info,
		.sync_mode = WB_SYNC_ALL,
		.nr_to_write = LONG_MAX,
		.for_writepages = 1,
		.range_cyclic = 1,
		};
		int ret;

fs/block_dev.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -420,7 +420,6 @@ static void bdev_destroy_inode(struct inode *inode)
		{
		struct bdev_inode *bdi = BDEV_I(inode);

		bdi->bdev.bd_inode_backing_dev_info = NULL;
		kmem_cache_free(bdev_cachep, bdi);
		}

fs/btrfs/disk-io.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -1600,6 +1600,7 @@ struct btrfs_root open_ctree(struct super_block sb,

		sb->s_blocksize = 4096;
		sb->s_blocksize_bits = blksize_bits(4096);
		sb->s_bdi = &fs_info->bdi;

		/*
		* we set the i_size on the btree inode to the max possible int.

fs/btrfs/ordered-data.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -740,7 +740,6 @@ int btrfs_fdatawrite_range(struct address_space *mapping, loff_t start,
		.nr_to_write = mapping->nrpages * 2,
		.range_start = start,
		.range_end = end,
		.for_writepages = 1,
		};
		return btrfs_writepages(mapping, &wbc);
		}

fs/fs-writeback.c

+158 −187

Original line number	Diff line number	Diff line
		@@ -34,22 +34,30 @@
		*/
		int nr_pdflush_threads;

		/*
		* Passed into wb_writeback(), essentially a subset of writeback_control
		*/
		struct wb_writeback_args {
		long nr_pages;
		struct super_block *sb;
		enum writeback_sync_modes sync_mode;
		int for_kupdate;
		int range_cyclic;
		};

		/*
		* Work items for the bdi_writeback threads
		*/
		struct bdi_work {
		struct list_head list;
		struct list_head wait_list;
		struct rcu_head rcu_head;
		struct list_head list; /* pending work list */
		struct rcu_head rcu_head; /* for RCU free/clear of work */

		unsigned long seen;
		atomic_t pending;
		unsigned long seen; /* threads that have seen this work */
		atomic_t pending; /* number of threads still to do work */

		struct super_block *sb;
		unsigned long nr_pages;
		enum writeback_sync_modes sync_mode;
		struct wb_writeback_args args; /* writeback arguments */

		unsigned long state;
		unsigned long state; /* flag bits, see WS_* */
		};

		enum {
		@@ -66,22 +74,13 @@ static inline bool bdi_work_on_stack(struct bdi_work *work)
		}

		static inline void bdi_work_init(struct bdi_work *work,
		struct writeback_control *wbc)
		struct wb_writeback_args *args)
		{
		INIT_RCU_HEAD(&work->rcu_head);
		work->sb = wbc->sb;
		work->nr_pages = wbc->nr_to_write;
		work->sync_mode = wbc->sync_mode;
		work->args = *args;
		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.
		@@ -98,6 +97,11 @@ static void bdi_work_clear(struct bdi_work *work)
		{
		clear_bit(WS_USED_B, &work->state);
		smp_mb__after_clear_bit();
		/*
		* work can have disappeared at this point. bit waitq functions
		* should be able to tolerate this, provided bdi_sched_wait does
		* not dereference it's pointer argument.
		*/
		wake_up_bit(&work->state, WS_USED_B);
		}

		@@ -113,7 +117,8 @@ static void bdi_work_free(struct rcu_head *head)

		static void wb_work_complete(struct bdi_work *work)
		{
		const enum writeback_sync_modes sync_mode = work->sync_mode;
		const enum writeback_sync_modes sync_mode = work->args.sync_mode;
		int onstack = bdi_work_on_stack(work);

		/*
		* For allocated work, we can clear the done/seen bit right here.
		@@ -121,9 +126,9 @@ static void wb_work_complete(struct bdi_work *work)
		* to after the RCU grace period, since the stack could be invalidated
		* as soon as bdi_work_clear() has done the wakeup.
		*/
		if (!bdi_work_on_stack(work))
		if (!onstack)
		bdi_work_clear(work);
		if (sync_mode == WB_SYNC_NONE \|\| bdi_work_on_stack(work))
		if (sync_mode == WB_SYNC_NONE \|\| onstack)
		call_rcu(&work->rcu_head, bdi_work_free);
		}

		@@ -146,21 +151,19 @@ static void wb_clear_pending(struct bdi_writeback wb, struct bdi_work work)

		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);

		/*
		* Make sure stores are seen before it appears on the list
		* list_add_tail_rcu() contains the necessary barriers to
		* make sure the above stores are seen before the item is
		* noticed on the list
		*/
		smp_mb();

		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
		@@ -171,15 +174,7 @@ static void bdi_queue_work(struct backing_dev_info bdi, struct bdi_work work)
		else {
		struct bdi_writeback *wb = &bdi->wb;

		/*
		* If we failed allocating the bdi work item, wake up the wb
		* thread always. As a safety precaution, it'll flush out
		* everything
		*/
		if (!wb_has_dirty_io(wb)) {
		if (work)
		wb_clear_pending(wb, work);
		} else if (wb->task)
		if (wb->task)
		wake_up_process(wb->task);
		}
		}
		@@ -194,48 +189,75 @@ static void bdi_wait_on_work_clear(struct bdi_work *work)
		TASK_UNINTERRUPTIBLE);
		}

		static struct bdi_work bdi_alloc_work(struct writeback_control wbc)
		static void bdi_alloc_queue_work(struct backing_dev_info *bdi,
		struct wb_writeback_args *args)
		{
		struct bdi_work *work;

		/*
		* This is WB_SYNC_NONE writeback, so if allocation fails just
		* wakeup the thread for old dirty data writeback
		*/
		work = kmalloc(sizeof(*work), GFP_ATOMIC);
		if (work)
		bdi_work_init(work, wbc);
		if (work) {
		bdi_work_init(work, args);
		bdi_queue_work(bdi, work);
		} else {
		struct bdi_writeback *wb = &bdi->wb;

		return work;
		if (wb->task)
		wake_up_process(wb->task);
		}
		}

		void bdi_start_writeback(struct writeback_control *wbc)
		/**
		* bdi_sync_writeback - start and wait for writeback
		* @bdi: the backing device to write from
		* @sb: write inodes from this super_block
		*
		* Description:
		* This does WB_SYNC_ALL data integrity writeback and waits for the
		* IO to complete. Callers must hold the sb s_umount semaphore for
		* reading, to avoid having the super disappear before we are done.
		*/
		static void bdi_sync_writeback(struct backing_dev_info *bdi,
		struct super_block *sb)
		{
		const bool must_wait = wbc->sync_mode == WB_SYNC_ALL;
		struct bdi_work work_stack, *work = NULL;
		struct wb_writeback_args args = {
		.sb = sb,
		.sync_mode = WB_SYNC_ALL,
		.nr_pages = LONG_MAX,
		.range_cyclic = 0,
		};
		struct bdi_work work;

		if (!must_wait)
		work = bdi_alloc_work(wbc);
		bdi_work_init(&work, &args);
		work.state \|= WS_ONSTACK;

		if (!work) {
		work = &work_stack;
		bdi_work_init_on_stack(work, wbc);
		bdi_queue_work(bdi, &work);
		bdi_wait_on_work_clear(&work);
		}

		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.
		/**
		* bdi_start_writeback - start writeback
		* @bdi: the backing device to write from
		* @nr_pages: the number of pages to write
		*
		* Description:
		* This does WB_SYNC_NONE opportunistic writeback. The IO is only
		* started when this function returns, we make no guarentees on
		* completion. Caller need not hold sb s_umount semaphore.
		*
		* 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);
		}
		void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages)
		{
		struct wb_writeback_args args = {
		.sync_mode = WB_SYNC_NONE,
		.nr_pages = nr_pages,
		.range_cyclic = 1,
		};

		bdi_alloc_queue_work(bdi, &args);
		}

		/*
		@@ -671,17 +693,16 @@ static inline bool over_bground_thresh(void)
		* 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)
		static long wb_writeback(struct bdi_writeback *wb,
		struct wb_writeback_args *args)
		{
		struct writeback_control wbc = {
		.bdi = wb->bdi,
		.sb = sb,
		.sync_mode = sync_mode,
		.sb = args->sb,
		.sync_mode = args->sync_mode,
		.older_than_this = NULL,
		.for_kupdate = for_kupdate,
		.range_cyclic = 1,
		.for_kupdate = args->for_kupdate,
		.range_cyclic = args->range_cyclic,
		};
		unsigned long oldest_jif;
		long wrote = 0;
		@@ -691,13 +712,18 @@ static long wb_writeback(struct bdi_writeback *wb, long nr_pages,
		oldest_jif = jiffies -
		msecs_to_jiffies(dirty_expire_interval * 10);
		}
		if (!wbc.range_cyclic) {
		wbc.range_start = 0;
		wbc.range_end = LLONG_MAX;
		}

		for (;;) {
		/*
		* Don't flush anything for non-integrity writeback where
		* no nr_pages was given
		*/
		if (!for_kupdate && nr_pages <= 0 && sync_mode == WB_SYNC_NONE)
		if (!args->for_kupdate && args->nr_pages <= 0 &&
		args->sync_mode == WB_SYNC_NONE)
		break;

		/*
		@@ -705,7 +731,8 @@ static long wb_writeback(struct bdi_writeback *wb, long nr_pages,
		* periodic background writeout and we are below the
		* background dirty threshold, don't do anything
		*/
		if (for_kupdate && nr_pages <= 0 && !over_bground_thresh())
		if (args->for_kupdate && args->nr_pages <= 0 &&
		!over_bground_thresh())
		break;

		wbc.more_io = 0;
		@@ -713,7 +740,7 @@ static long wb_writeback(struct bdi_writeback *wb, long nr_pages,
		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;
		args->nr_pages -= MAX_WRITEBACK_PAGES - wbc.nr_to_write;
		wrote += MAX_WRITEBACK_PAGES - wbc.nr_to_write;

		/*
		@@ -731,7 +758,11 @@ static long wb_writeback(struct bdi_writeback *wb, long nr_pages,

		/*
		* Return the next bdi_work struct that hasn't been processed by this
		* wb thread yet
		* wb thread yet. ->seen is initially set for each thread that exists
		* for this device, when a thread first notices a piece of work it
		* clears its bit. Depending on writeback type, the thread will notify
		* completion on either receiving the work (WB_SYNC_NONE) or after
		* it is done (WB_SYNC_ALL).
		*/
		static struct bdi_work get_next_work_item(struct backing_dev_info bdi,
		struct bdi_writeback *wb)
		@@ -741,8 +772,9 @@ static struct bdi_work get_next_work_item(struct backing_dev_info bdi,
		rcu_read_lock();

		list_for_each_entry_rcu(work, &bdi->work_list, list) {
		if (!test_and_clear_bit(wb->nr, &work->seen))
		if (!test_bit(wb->nr, &work->seen))
		continue;
		clear_bit(wb->nr, &work->seen);

		ret = work;
		break;
		@@ -767,8 +799,16 @@ static long wb_check_old_data_flush(struct bdi_writeback *wb)
		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);
		if (nr_pages) {
		struct wb_writeback_args args = {
		.nr_pages = nr_pages,
		.sync_mode = WB_SYNC_NONE,
		.for_kupdate = 1,
		.range_cyclic = 1,
		};

		return wb_writeback(wb, &args);
		}

		return 0;
		}
		@@ -780,35 +820,31 @@ 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;
		long wrote = 0;

		while ((work = get_next_work_item(bdi, wb)) != NULL) {
		enum writeback_sync_modes sync_mode;

		nr_pages = work->nr_pages;
		struct wb_writeback_args args = work->args;

		/*
		* 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;
		work->args.sync_mode = args.sync_mode = WB_SYNC_ALL;

		/*
		* 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)
		if (args.sync_mode == WB_SYNC_NONE)
		wb_clear_pending(wb, work);

		wrote += wb_writeback(wb, nr_pages, work->sb, sync_mode, 0);
		wrote += wb_writeback(wb, &args);

		/*
		* This is a data integrity writeback, so only do the
		* notification when we have completed the work.
		*/
		if (sync_mode == WB_SYNC_ALL)
		if (args.sync_mode == WB_SYNC_ALL)
		wb_clear_pending(wb, work);
		}

		@@ -849,8 +885,7 @@ int bdi_writeback_task(struct bdi_writeback *wb)
		}

		wait_jiffies = msecs_to_jiffies(dirty_writeback_interval * 10);
		set_current_state(TASK_INTERRUPTIBLE);
		schedule_timeout(wait_jiffies);
		schedule_timeout_interruptible(wait_jiffies);
		try_to_freeze();
		}

		@@ -858,67 +893,28 @@ int bdi_writeback_task(struct bdi_writeback *wb)
		}

		/*
		* 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.
		* Schedule writeback for all backing devices. This does WB_SYNC_NONE
		* writeback, for integrity writeback see bdi_sync_writeback().
		*/
		static void bdi_writeback_all(struct writeback_control *wbc)
		static void bdi_writeback_all(struct super_block *sb, long nr_pages)
		{
		const bool must_wait = wbc->sync_mode == WB_SYNC_ALL;
		struct wb_writeback_args args = {
		.sb = sb,
		.nr_pages = nr_pages,
		.sync_mode = WB_SYNC_NONE,
		};
		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;
		rcu_read_lock();

		list_for_each_entry_rcu(bdi, &bdi_list, bdi_list) {
		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;
		}
		if (must_wait)
		list_add_tail(&work->wait_list, &list);

		bdi_queue_work(bdi, work);
		bdi_alloc_queue_work(bdi, &args);
		}

		spin_unlock(&bdi_lock);

		/*
		* 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);
		}
		rcu_read_unlock();
		}

		/*
		@@ -927,17 +923,10 @@ restart:
		*/
		void wakeup_flusher_threads(long nr_pages)
		{
		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);
		bdi_writeback_all(NULL, nr_pages);
		}

		static noinline void block_dump___mark_inode_dirty(struct inode *inode)
		@@ -1084,7 +1073,7 @@ EXPORT_SYMBOL(__mark_inode_dirty);
		* 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.
		*/
		static void wait_sb_inodes(struct writeback_control *wbc)
		static void wait_sb_inodes(struct super_block *sb)
		{
		struct inode inode, old_inode = NULL;

		@@ -1092,7 +1081,7 @@ static void wait_sb_inodes(struct writeback_control *wbc)
		* 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));
		WARN_ON(!rwsem_is_locked(&sb->s_umount));

		spin_lock(&inode_lock);

		@@ -1103,7 +1092,7 @@ static void wait_sb_inodes(struct writeback_control *wbc)
		* 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) {
		list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
		struct address_space *mapping;

		if (inode->i_state & (I_FREEING\|I_CLEAR\|I_WILL_FREE\|I_NEW))
		@@ -1143,14 +1132,8 @@ static void wait_sb_inodes(struct writeback_control *wbc)
		* for IO completion of submitted IO. The number of pages submitted is
		* returned.
		*/
		long writeback_inodes_sb(struct super_block *sb)
		void writeback_inodes_sb(struct super_block *sb)
		{
		struct writeback_control wbc = {
		.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;
		@@ -1158,9 +1141,7 @@ long writeback_inodes_sb(struct super_block *sb)
		nr_to_write = nr_dirty + nr_unstable +
		(inodes_stat.nr_inodes - inodes_stat.nr_unused);

		wbc.nr_to_write = nr_to_write;
		bdi_writeback_all(&wbc);
		return nr_to_write - wbc.nr_to_write;
		bdi_writeback_all(sb, nr_to_write);
		}
		EXPORT_SYMBOL(writeback_inodes_sb);

		@@ -1171,20 +1152,10 @@ EXPORT_SYMBOL(writeback_inodes_sb);
		* 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)
		void 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;
		bdi_sync_writeback(sb->s_bdi, sb);
		wait_sb_inodes(sb);
		}
		EXPORT_SYMBOL(sync_inodes_sb);

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