Bootcache now gets alignment from dm-bootcache
The alignement of various on disk data structures for
the bootcache was hard coded to be page size. Now, it
is communicated via the Header.
BUG=chromium-os:25441
TEST=boot the system with bootcache enabled
Change-Id: I51e526d4ce5b760a5597cc7812dd89a317bb2384
Reviewed-on: https://gerrit.chromium.org/gerrit/33096
Commit-Ready: Paul Taysom <taysom@chromium.org>
Reviewed-by: Paul Taysom <taysom@chromium.org>
Tested-by: Paul Taysom <taysom@chromium.org>
diff --git a/bootcache.c b/bootcache.c
index 5fa9a8f..5abcc95 100644
--- a/bootcache.c
+++ b/bootcache.c
@@ -13,7 +13,9 @@
* the blocks used during boot.
*
* Sizes and offsets are measured in 512 byte sectors.
- * Space is allocated in CHUNK_SIZE chunks.
+ * Space is allocated in chunks. The size of chunks is
+ * derived from alignment restrictions obtained from
+ * the header.
*
* bootcache [-t] <device-name> <raw-partition>
*
@@ -61,11 +63,9 @@
typedef uint64_t u64;
typedef uint32_t u32;
-#define CHUNK_SIZE 4096 /* todo(taysom) should get from bootcache_hdr */
#define SECTOR_SHIFT 9
#define MAX_CHUNKS 128
#define MAX_FILE_NAME 256
-#define SECTORS_PER_CHUNK (CHUNK_SIZE >> SECTOR_SHIFT)
#define MAX_MSG 1024
static struct bootcache_hdr Header;
@@ -83,6 +83,8 @@
static u64 Trace_start;
static u64 Cache_start;
+static u64 Chunk_size;
+static u64 Sectors_per_chunk;
#define fatal(fmt, ...) pr_fatal(__FILE__, __FUNCTION__, __LINE__, \
fmt, ## __VA_ARGS__)
@@ -172,12 +174,12 @@
return rc;
}
-static void *malloc_buf(size_t npages)
+static void *malloc_buf(size_t nchunks)
{
void *buf;
int rc;
- rc = posix_memalign(&buf, CHUNK_SIZE, npages * CHUNK_SIZE);
+ rc = posix_memalign(&buf, Chunk_size, nchunks * Chunk_size);
if (rc) {
fatal("posix_memalign rc=%d", rc);
}
@@ -200,7 +202,7 @@
u64 num_bytes = Trace.num * sizeof(*Trace.tr);
/* Align to page boundary then convert to sectors */
- return ((num_bytes + CHUNK_SIZE - 1) / CHUNK_SIZE) * SECTORS_PER_CHUNK;
+ return ((num_bytes + Chunk_size - 1) / Chunk_size) * Sectors_per_chunk;
}
static void compute_sections(void)
@@ -208,7 +210,7 @@
Header.num_trace_recs = Trace.num;
Header.sectors_meta = num_meta_sectors();
Header.sectors_data = num_sectors_in_cache();
- Trace_start = Header.sector + SECTORS_PER_CHUNK;
+ Trace_start = Header.sector + Sectors_per_chunk;
Cache_start = Trace_start + Header.sectors_meta;
}
@@ -221,7 +223,7 @@
offset = tr.sector << SECTOR_SHIFT;
remainder = tr.count << SECTOR_SHIFT;
- n = MAX_CHUNKS * CHUNK_SIZE;
+ n = MAX_CHUNKS * Chunk_size;
while (remainder) {
if (n > remainder) {
n = remainder;
@@ -289,7 +291,7 @@
*/
static u64 num_bytes(const char *file)
{
- char buf[CHUNK_SIZE];
+ char buf[Chunk_size];
ssize_t rc;
u64 sum = 0;
@@ -356,6 +358,8 @@
if (Header.version != BOOTCACHE_VERSION) {
fatal("Bad version %u != %u", Header.version, BOOTCACHE_VERSION);
}
+ Chunk_size = Header.alignment;
+ Sectors_per_chunk = Chunk_size >> SECTOR_SHIFT;
}
/*
diff --git a/dm-bootcache.h b/dm-bootcache.h
index 536911f..5bb2553 100644
--- a/dm-bootcache.h
+++ b/dm-bootcache.h
@@ -17,7 +17,7 @@
#include <linux/types.h>
enum { BOOTCACHE_MAGIC = 1651470196,
- BOOTCACHE_VERSION = 2,
+ BOOTCACHE_VERSION = 3,
MAX_SIGNATURE = 256
};
@@ -37,6 +37,7 @@
__u32 sectors_data; /* Size of the data area in sectors*/
__u32 max_sectors; /* Max sectors that can to read */
__u32 max_hw_sectors; /* Max hardware sectore that can be read */
+ __u32 alignment; /* Alignement on disk */
char date[12]; /* Date and time dm-bootcache was compiled */
char time[12];
char signature[MAX_SIGNATURE];
