From 33a180623b6c35f2727daecb63763955af3af1df Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Tue, 2 Jun 2020 15:34:40 +0200 Subject: dm bufio: introduce forget_buffer_locked Introduce a function forget_buffer_locked that forgets a range of buffers. It is more efficient than calling forget_buffer in a loop. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer --- drivers/md/dm-bufio.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 56 insertions(+), 4 deletions(-) (limited to 'drivers/md/dm-bufio.c') diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c index ff19add97e0b..95f6c544aa01 100644 --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -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; -- cgit v1.2.3