[PATCH 1/6] block: Add blk_completion
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Date: 2020-10-22 21:22:34
Also in:
linux-fscrypt, linux-fsdevel, lkml
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
This new data structure allows a task to wait for N things to complete. Usually the submitting task will handle cleanup, but if it is killed, the last completer will take care of it. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- block/blk-core.c | 61 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/bio.h | 11 ++++++++ 2 files changed, 72 insertions(+)
diff --git a/block/blk-core.c b/block/blk-core.c
index 10c08ac50697..2892246f2176 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c@@ -1900,6 +1900,67 @@ void blk_io_schedule(void) } EXPORT_SYMBOL_GPL(blk_io_schedule); +void blk_completion_init(struct blk_completion *cmpl, int n) +{ + spin_lock_init(&cmpl->cmpl_lock); + cmpl->cmpl_count = n; + cmpl->cmpl_task = current; + cmpl->cmpl_status = BLK_STS_OK; +} + +int blk_completion_sub(struct blk_completion *cmpl, blk_status_t status, int n) +{ + int ret = 0; + + spin_lock_bh(&cmpl->cmpl_lock); + if (cmpl->cmpl_status == BLK_STS_OK && status != BLK_STS_OK) + cmpl->cmpl_status = status; + cmpl->cmpl_count -= n; + BUG_ON(cmpl->cmpl_count < 0); + if (cmpl->cmpl_count == 0) { + if (cmpl->cmpl_task) + wake_up_process(cmpl->cmpl_task); + else + ret = -EINTR; + } + spin_unlock_bh(&cmpl->cmpl_lock); + if (ret < 0) + kfree(cmpl); + return ret; +} + +int blk_completion_wait_killable(struct blk_completion *cmpl) +{ + int err = 0; + + for (;;) { + set_current_state(TASK_KILLABLE); + spin_lock_bh(&cmpl->cmpl_lock); + if (cmpl->cmpl_count == 0) + break; + spin_unlock_bh(&cmpl->cmpl_lock); + blk_io_schedule(); + if (fatal_signal_pending(current)) { + spin_lock_bh(&cmpl->cmpl_lock); + cmpl->cmpl_task = NULL; + if (cmpl->cmpl_count != 0) { + spin_unlock_bh(&cmpl->cmpl_lock); + cmpl = NULL; + } + err = -ERESTARTSYS; + break; + } + } + set_current_state(TASK_RUNNING); + if (cmpl) { + spin_unlock_bh(&cmpl->cmpl_lock); + err = blk_status_to_errno(cmpl->cmpl_status); + kfree(cmpl); + } + + return err; +} + int __init blk_dev_init(void) { BUILD_BUG_ON(REQ_OP_LAST >= (1 << REQ_OP_BITS));
diff --git a/include/linux/bio.h b/include/linux/bio.h
index f254bc79bb3a..0bde05f5548c 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h@@ -814,4 +814,15 @@ static inline void bio_set_polled(struct bio *bio, struct kiocb *kiocb) bio->bi_opf |= REQ_NOWAIT; } +struct blk_completion { + struct task_struct *cmpl_task; + spinlock_t cmpl_lock; + int cmpl_count; + blk_status_t cmpl_status; +}; + +void blk_completion_init(struct blk_completion *, int n); +int blk_completion_sub(struct blk_completion *, blk_status_t status, int n); +int blk_completion_wait_killable(struct blk_completion *); + #endif /* __LINUX_BIO_H */
--
2.28.0