1 files changed, 72 insertions, 13 deletions

diff --git a/extent_io.c b/extent_io.c
index 973e918..5093aeb 100644
--- a/extent_io.c
+++ b/extent_io.c
@@ -27,8 +27,11 @@
 #include "kerncompat.h"
 #include "extent_io.h"
 #include "list.h"
+#include "ctree.h"
+#include "volumes.h"
 
-u64 cache_max = 1024 * 1024 * 32;
+u64 cache_soft_max = 1024 * 1024 * 256;
+u64 cache_hard_max = 1 * 1024 * 1024 * 1024;
 
 void extent_io_tree_init(struct extent_io_tree *tree)
 {
@@ -47,7 +50,7 @@ static struct extent_state *alloc_extent_state(void)
 		return NULL;
 	state->refs = 1;
 	state->state = 0;
-	state->private = 0;
+	state->xprivate = 0;
 	return state;
 }
 
@@ -299,9 +302,11 @@ int set_extent_bits(struct extent_io_tree *tree, u64 start,
 	u64 last_start;
 	u64 last_end;
 again:
-	prealloc = alloc_extent_state();
-	if (!prealloc)
-		return -ENOMEM;
+	if (!prealloc) {
+		prealloc = alloc_extent_state();
+		if (!prealloc)
+			return -ENOMEM;
+	}
 
 	/*
 	 * this search will find the extents that end after
@@ -508,7 +513,7 @@ int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
 		ret = -ENOENT;
 		goto out;
 	}
-	state->private = private;
+	state->xprivate = private;
 out:
 	return ret;
 }
@@ -529,7 +534,7 @@ int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
 		ret = -ENOENT;
 		goto out;
 	}
-	*private = state->private;
+	*private = state->xprivate;
 out:
 	return ret;
 }
@@ -540,18 +545,19 @@ static int free_some_buffers(struct extent_io_tree *tree)
 	struct extent_buffer *eb;
 	struct list_head *node, *next;
 
-	if (tree->cache_size < cache_max)
+	if (tree->cache_size < cache_soft_max)
 		return 0;
+
 	list_for_each_safe(node, next, &tree->lru) {
 		eb = list_entry(node, struct extent_buffer, lru);
 		if (eb->refs == 1) {
 			free_extent_buffer(eb);
-			if (tree->cache_size < cache_max)
+			if (tree->cache_size < cache_hard_max)
 				break;
 		} else {
 			list_move_tail(&eb->lru, &tree->lru);
 		}
-		if (nrscan++ > 64)
+		if (nrscan++ > 64 && tree->cache_size < cache_hard_max)
 			break;
 	}
 	return 0;
@@ -661,13 +667,14 @@ struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
 	return eb;
 }
 
-int read_extent_from_disk(struct extent_buffer *eb)
+int read_extent_from_disk(struct extent_buffer *eb,
+			  unsigned long offset, unsigned long len)
 {
 	int ret;
-	ret = pread(eb->fd, eb->data, eb->len, eb->dev_bytenr);
+	ret = pread(eb->fd, eb->data + offset, len, eb->dev_bytenr);
 	if (ret < 0)
 		goto out;
-	if (ret != eb->len) {
+	if (ret != len) {
 		ret = -EIO;
 		goto out;
 	}
@@ -691,6 +698,55 @@ out:
 	return ret;
 }
 
+int read_data_from_disk(struct btrfs_fs_info *info, void *buf, u64 offset,
+			u64 bytes, int mirror)
+{
+	struct btrfs_multi_bio *multi = NULL;
+	struct btrfs_device *device;
+	u64 bytes_left = bytes;
+	u64 read_len;
+	u64 total_read = 0;
+	int ret;
+
+	while (bytes_left) {
+		read_len = bytes_left;
+		ret = btrfs_map_block(&info->mapping_tree, READ, offset,
+				      &read_len, &multi, mirror, NULL);
+		if (ret) {
+			fprintf(stderr, "Couldn't map the block %Lu\n",
+				offset);
+			return -EIO;
+		}
+		device = multi->stripes[0].dev;
+
+		read_len = min(bytes_left, read_len);
+		if (device->fd == 0) {
+			kfree(multi);
+			return -EIO;
+		}
+
+		ret = pread(device->fd, buf + total_read, read_len,
+			    multi->stripes[0].physical);
+		kfree(multi);
+		if (ret < 0) {
+			fprintf(stderr, "Error reading %Lu, %d\n", offset,
+				ret);
+			return ret;
+		}
+		if (ret != read_len) {
+			fprintf(stderr, "Short read for %Lu, read %d, "
+				"read_len %Lu\n", offset, ret, read_len);
+			return -EIO;
+		}
+
+		bytes_left -= read_len;
+		offset += read_len;
+		total_read += read_len;
+	}
+
+	return 0;
+}
+
 int set_extent_buffer_uptodate(struct extent_buffer *eb)
 {
 	eb->flags |= EXTENT_UPTODATE;
@@ -706,6 +762,9 @@ int clear_extent_buffer_uptodate(struct extent_io_tree *tree,
 
 int extent_buffer_uptodate(struct extent_buffer *eb)
 {
+	if (!eb)
+		return 0;
+
 	if (eb->flags & EXTENT_UPTODATE)
 		return 1;
 	return 0;