PR-1053: Sort out buffer init.

Signed-off-by: Daniel Stodden <daniel.stodden@citrix.com>

diff --git a/drivers/block-lcache.c b/drivers/block-lcache.c
index df0fc843fbe0d120c72b647d986804924cdf50fb..cb85123444383abe1a6b26d0b8f34ef2c8c999dc 100644 (file)
--- a/drivers/block-lcache.c
+++ b/drivers/block-lcache.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (c) 2010, XenSource Inc.
  * All rights reserved.
  *
@@ -50,7 +50,7 @@
 
 #define WARN(_f, _a...) tlog_write(TLOG_WARN, _f, ##_a)
 #define BUG()           td_panic()
-#define BUG_ON(_cond)   if (_cond) { td_panic(); }
+#define BUG_ON(_cond)   if (unlikely(_cond)) { td_panic(); }
 
 #define TD_LCACHE_MAX_REQ               (MAX_REQUESTS*2)
 #define TD_LCACHE_BUFSZ                 (MAX_SEGMENTS_PER_REQ * \
@@ -100,17 +100,59 @@ lcache_free_request(td_lcache_t *cache, td_lcache_req_t *req)
        cache->free[cache->n_free++] = req;
 }
 
+static void
+lcache_destroy_buffers(td_lcache_t *cache)
+{
+       td_lcache_req_t *req;
+
+       do {
+               req = lcache_alloc_request(cache);
+               if (req)
+                       munmap(req->buf, TD_LCACHE_BUFSZ);
+       } while (req);
+}
+
+static int
+lcache_create_buffers(td_lcache_t *cache)
+{
+       int prot, flags, i, err;
+       size_t bufsz;
+
+       prot  = PROT_READ|PROT_WRITE;
+       flags = MAP_ANONYMOUS|MAP_PRIVATE|MAP_LOCKED;
+
+       cache->n_free = 0;
+
+       for (i = 0; i < TD_LCACHE_MAX_REQ; i++) {
+               td_lcache_req_t *req = &cache->reqv[i];
+
+               req->buf = mmap(NULL, TD_LCACHE_BUFSZ, prot, flags, -1, 0);
+               if (req->buf == MAP_FAILED) {
+                       req->buf = NULL;
+                       err = -errno;
+                       goto fail;
+               }
+
+               lcache_free_request(cache, req);
+       }
+
+       return 0;
+
+fail:
+       EPRINTF("Buffer init failure: %d", err);
+       lcache_destroy_buffers(cache);
+       return err;
+}
+
 static int
 lcache_close(td_driver_t *driver)
 {
        td_lcache_t *cache = driver->data;
 
-       DPRINTF("Closing local cache for %s\n", cache->name);
-
-       if (cache->buf)
-               munmap(cache->buf, cache->bufsz);
+       lcache_destroy_buffers(cache);
 
        free(cache->name);
+
        return 0;
 }
 
@@ -122,36 +164,14 @@ lcache_open(td_driver_t *driver, const char *name, td_flag_t flags)
        int prot, _flags;
        size_t lreq_bufsz;
 
-       err   = tapdisk_namedup(&cache->name, (char *)name);
+       err  = tapdisk_namedup(&cache->name, (char *)name);
        if (err)
                goto fail;
 
-       lreq_bufsz   = MAX_SEGMENTS_PER_REQ * sysconf(_SC_PAGE_SIZE);
-       cache->bufsz = TD_LCACHE_MAX_REQ * lreq_bufsz;
-
-       prot   = PROT_READ|PROT_WRITE;
-       _flags = MAP_ANONYMOUS|MAP_PRIVATE;
-       cache->buf = mmap(NULL, cache->bufsz, prot, _flags, -1, 0);
-       if (cache->buf == MAP_FAILED) {
-               cache->buf == NULL;
-               err = -errno;
-               goto fail;
-       }
-
-       err = mlock(cache->buf, cache->bufsz);
-       if (err) {
-               err = -errno;
+       err = lcache_create_buffers(cache);
+       if (err)
                goto fail;
-       }
-
-       cache->n_free = TD_LCACHE_MAX_REQ;
-       for (i = 0; i < TD_LCACHE_MAX_REQ; i++) {
-               td_lcache_req_t *req = &cache->reqv[i];
-               req->buf = cache->buf + i * lreq_bufsz;
-               cache->free[i] = req;
-       }
 
-       DPRINTF("Opening local cache for %s\n", cache->name);
        return 0;
 
 fail: