From e9e73bc0270483d10cf4dc19da76b91a9f95e337 Mon Sep 17 00:00:00 2001
From: Max Wash <mbswash@gmail.com>
Date: Tue, 11 Jul 2023 21:28:02 +0100
Subject: [PATCH] dev: removed internal spinlock from bcache

bcaches must now have an explicit external lock to protect them from
concurrent access (i.e. a lock belonging to their parent block device)
---
 dev/block.c           | 11 -----------
 include/socks/block.h | 10 ----------
 2 files changed, 21 deletions(-)

diff --git a/dev/block.c b/dev/block.c
index 62d8074..7f8ae78 100644
--- a/dev/block.c
+++ b/dev/block.c
@@ -91,8 +91,6 @@ kern_status_t block_device_read_blocks(struct device *dev, void *buf, sectors_t
 		return do_read_blocks(blockdev, buf, offset, nr_sectors, sectors_read, flags);
 	}
 
-	bcache_lock(&blockdev->b_cache);
-
 	size_t nr_read = 0;
 
 	kern_status_t status = KERN_OK;
@@ -101,7 +99,6 @@ kern_status_t block_device_read_blocks(struct device *dev, void *buf, sectors_t
 		void *sect_cache_buf;
 		status = get_cached_sector(blockdev, sect, flags, &sect_cache_buf);
 		if (status != KERN_OK) {
-			bcache_unlock(&blockdev->b_cache);
 			*sectors_read = nr_read;
 			return status;
 		}
@@ -111,7 +108,6 @@ kern_status_t block_device_read_blocks(struct device *dev, void *buf, sectors_t
 		nr_read++;
 	}
 
-	bcache_unlock(&blockdev->b_cache);
 	*sectors_read = nr_read;
 	return KERN_OK;
 }
@@ -142,8 +138,6 @@ kern_status_t block_device_read(struct device *dev, void *buf, size_t offset, si
 		return status;
 	}
 
-	bcache_lock(&blockdev->b_cache);
-
 	char *dest = buf;
 
 	sectors_t first_sect = offset / blockdev->b_sector_size;
@@ -156,7 +150,6 @@ kern_status_t block_device_read(struct device *dev, void *buf, size_t offset, si
 		status = get_cached_sector(blockdev, first_sect, flags, &sector_cachebuf);
 
 		if (status != KERN_OK) {
-			bcache_unlock(&blockdev->b_cache);
 			*bytes_read = nr_read;
 			return status;
 		}
@@ -177,7 +170,6 @@ kern_status_t block_device_read(struct device *dev, void *buf, size_t offset, si
 		status = get_cached_sector(blockdev, i, flags, &sector_cachebuf);
 
 		if (status != KERN_OK) {
-			bcache_unlock(&blockdev->b_cache);
 			*bytes_read = nr_read;
 			return status;
 		}
@@ -195,7 +187,6 @@ kern_status_t block_device_read(struct device *dev, void *buf, size_t offset, si
 		status = get_cached_sector(blockdev, last_sect, flags, &sector_cachebuf);
 
 		if (status != KERN_OK) {
-			bcache_unlock(&blockdev->b_cache);
 			*bytes_read = nr_read;
 			return status;
 		}
@@ -207,7 +198,6 @@ kern_status_t block_device_read(struct device *dev, void *buf, size_t offset, si
 		nr_read += in_sect_size;
 	}
 
-	bcache_unlock(&blockdev->b_cache);
 	*bytes_read = nr_read;
 	return KERN_OK;
 }
@@ -284,7 +274,6 @@ kern_status_t bcache_init(struct bcache *cache, unsigned int block_size)
 	memset(cache, 0x0, sizeof *cache);
 	cache->b_sector_size = block_size;
 	cache->b_sectors_per_page = VM_PAGE_SIZE / block_size;
-	cache->b_lock = SPIN_LOCK_INIT;
 
 	return KERN_OK;
 }
diff --git a/include/socks/block.h b/include/socks/block.h
index e24d82d..bd78406 100644
--- a/include/socks/block.h
+++ b/include/socks/block.h
@@ -15,7 +15,6 @@ struct bcache {
 	unsigned int b_sector_size;
 	unsigned int b_sectors_per_page;
 	struct btree b_pagetree;
-	spin_lock_t b_lock;
 };
 
 struct bcache_sector {
@@ -31,15 +30,6 @@ extern void bcache_destroy(struct bcache *cache);
 extern kern_status_t bcache_init(struct bcache *cache, unsigned int block_size);
 extern void bcache_deinit(struct bcache *cache);
 
-static inline void bcache_lock(struct bcache *cache)
-{
-	spin_lock(&cache->b_lock);
-}
-static inline void bcache_unlock(struct bcache *cache)
-{
-	spin_unlock(&cache->b_lock);
-}
-
 extern kern_status_t bcache_get(struct bcache *cache, sectors_t at, bool create, struct bcache_sector *out);
 extern void bcache_mark_present(struct bcache_sector *sect);