dm bufio: introduce forget_buffer_locked (33a18062) · Commits · 戴 / test

drivers/md/dm-bufio.c

+56 −4

Original line number	Diff line number	Diff line
		@@ -262,6 +262,29 @@ static struct dm_buffer __find(struct dm_bufio_client c, sector_t block)
		return NULL;
		}

		static struct dm_buffer __find_next(struct dm_bufio_client c, sector_t block)
		{
		struct rb_node *n = c->buffer_tree.rb_node;
		struct dm_buffer *b;
		struct dm_buffer *best = NULL;

		while (n) {
		b = container_of(n, struct dm_buffer, node);

		if (b->block == block)
		return b;

		if (block <= b->block) {
		n = n->rb_left;
		best = b;
		} else {
		n = n->rb_right;
		}
		}

		return best;
		}

		static void __insert(struct dm_bufio_client c, struct dm_buffer b)
		{
		struct rb_node *new = &c->buffer_tree.rb_node, parent = NULL;
		@@ -1434,6 +1457,14 @@ retry:
		}
		EXPORT_SYMBOL_GPL(dm_bufio_release_move);

		static void forget_buffer_locked(struct dm_buffer *b)
		{
		if (likely(!b->hold_count) && likely(!b->state)) {
		__unlink_buffer(b);
		__free_buffer_wake(b);
		}
		}

		/*
		* Free the given buffer.
		*
		@@ -1447,15 +1478,36 @@ void dm_bufio_forget(struct dm_bufio_client *c, sector_t block)
		dm_bufio_lock(c);

		b = __find(c, block);
		if (b && likely(!b->hold_count) && likely(!b->state)) {
		__unlink_buffer(b);
		__free_buffer_wake(b);
		}
		if (b)
		forget_buffer_locked(b);

		dm_bufio_unlock(c);
		}
		EXPORT_SYMBOL_GPL(dm_bufio_forget);

		void dm_bufio_forget_buffers(struct dm_bufio_client *c, sector_t block, sector_t n_blocks)
		{
		struct dm_buffer *b;
		sector_t end_block = block + n_blocks;

		while (block < end_block) {
		dm_bufio_lock(c);

		b = __find_next(c, block);
		if (b) {
		block = b->block + 1;
		forget_buffer_locked(b);
		}

		dm_bufio_unlock(c);

		if (!b)
		break;
		}

		}
		EXPORT_SYMBOL_GPL(dm_bufio_forget_buffers);

		void dm_bufio_set_minimum_buffers(struct dm_bufio_client *c, unsigned n)
		{
		c->minimum_buffers = n;

include/linux/dm-bufio.h

+7 −0

Original line number	Diff line number	Diff line
		@@ -136,6 +136,13 @@ void dm_bufio_release_move(struct dm_buffer *b, sector_t new_block);
		*/
		void dm_bufio_forget(struct dm_bufio_client *c, sector_t block);

		/*
		* Free the given range of buffers.
		* This is just a hint, if the buffer is in use or dirty, this function
		* does nothing.
		*/
		void dm_bufio_forget_buffers(struct dm_bufio_client *c, sector_t block, sector_t n_blocks);

		/*
		* Set the minimum number of buffers before cleanup happens.
		*/

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