added chunked vmalloc to allow for larger ramdisks

diff --git a/trd/trd.c b/trd/trd.c
index fc260d62599716742d0b9d66c2a6843bc3f3382d..ef8107269d28e03572ebdabf1a85fdf4fc652b5b 100644 (file)
--- a/trd/trd.c
+++ b/trd/trd.c
@@ -20,18 +20,21 @@
 #include <asm/uaccess.h>
 
 #define TRD_BLOCK_SIZE 1024
+#define TRD_CHUNK_SIZE (32*TRD_BLOCK_SIZE)
 #define TRD_SIZE (trd_size<<10)
 
 static int trd_blocksizes[1] = {TRD_BLOCK_SIZE};
-static void *trd_base;
+static void **trd_base;
+static int trd_chunks;
 static unsigned trd_size = 4096;
 
 MODULE_PARM (trd_size, "1i");
 
 static void do_trd_request(request_queue_t * q)
 {
-       u_long start, len;
+       u_long start, ofs, len, len1;
        void *addr;
+       int chunk;
 
        while (1) {
                INIT_REQUEST;
@@ -53,12 +56,24 @@ static void do_trd_request(request_queue_t * q)
                        continue;
                }
 
-               addr = (void *) (((char *)trd_base) + start);
+               while (len) {
+                       chunk = start / TRD_CHUNK_SIZE;
+                       ofs = start % TRD_CHUNK_SIZE;
+                       addr = (void *) (((char *)(trd_base[chunk])) + ofs);
 
-               if (CURRENT->cmd == READ) {
-                       memcpy(CURRENT->buffer, (char *)addr, len);
-               } else {
-                       memcpy((char *)addr, CURRENT->buffer, len);
+                       len1 = len;
+                       if (ofs + len1 > TRD_CHUNK_SIZE) {
+                               len1 = TRD_CHUNK_SIZE - ofs;
+                       }
+
+                       if (CURRENT->cmd == READ) {
+                               memcpy(CURRENT->buffer, (char *)addr, len1);
+                       } else {
+                               memcpy((char *)addr, CURRENT->buffer, len1);
+                       }
+
+                       len -= len1;
+                       start += len1;
                }
            
                end_request(1);
@@ -107,13 +122,19 @@ static struct block_device_operations trd_fops =
 
 static int trd_init(void)
 {
-       trd_base = vmalloc(TRD_SIZE);
+       int i;
+
+       trd_chunks = (TRD_SIZE + (TRD_CHUNK_SIZE-1)) / TRD_CHUNK_SIZE;
+       trd_base = (void **)vmalloc(sizeof(void *)*trd_chunks);
+       if (!trd_base) goto nomem;
+       memset(trd_base, 0, sizeof(void *)*trd_chunks);
 
-       if (!trd_base) {
-               printk(KERN_ERR DEVICE_NAME ": Unable to allocate trd of size %d\n",
-                      TRD_SIZE);
-               return -1;
+       for (i=0;i<trd_chunks-1;i++) {
+               trd_base[i] = vmalloc(TRD_CHUNK_SIZE);
+               if (!trd_base[i]) goto nomem;
        }
+       trd_base[i] = vmalloc(TRD_SIZE - (i-1)*TRD_CHUNK_SIZE);
+       if (!trd_base[i]) goto nomem;
 
        if (register_blkdev(MAJOR_NR, DEVICE_NAME, &trd_fops)) {
                printk(KERN_ERR DEVICE_NAME ": Unable to register_blkdev(%d)\n", MAJOR_NR);
@@ -127,12 +148,32 @@ static int trd_init(void)
        printk(KERN_DEBUG DEVICE_NAME ": trd initialised size=%d\n", TRD_SIZE);
 
        return 0;
+
+nomem:
+       if (trd_base) {
+               for (i=0;i<trd_chunks;i++) {
+                       if (trd_base[i]) vfree(trd_base[i]);
+               }
+               vfree(trd_base);
+               trd_base = NULL;
+       }       
+
+       printk(KERN_ERR DEVICE_NAME ": Unable to allocate trd of size %d\n",
+              TRD_SIZE);
+       return -ENOMEM;
 }
 
 static void __exit trd_cleanup(void)
 {
+       int i;
+
        unregister_blkdev(MAJOR_NR, DEVICE_NAME);
+
+       for (i=0;i<trd_chunks;i++) {
+               vfree(trd_base[i]);
+       }
        vfree(trd_base);
+       trd_base = NULL;
 }
 
 module_init(trd_init);