Standardized on externally provided config structs in the block devices

I have another branch where I tried exploring inlined config structs
backed by RAM, but this did not work out due to additional RAM and ROM costs.

Changing the bds to follow this was surprisingly annoying, as they had a
lot of shared geometry that was previously in a single shared config
object, and the way that testbd contains either of rambd and filebd made
configuring all three of these a bit complicated.

Ended up settling on a lfs_testbd_cfg that contains optional pointers to
lfs_rambd_cfg and lfs_filebd_cfg. These can be NULL, but only if that
bd goes unused.

6 files changed, 83 insertions, 97 deletions

diff --git a/bd/lfs_filebd.c b/bd/lfs_filebd.c
index c738837..edc0c8b 100644
--- a/bd/lfs_filebd.c
+++ b/bd/lfs_filebd.c
@@ -19,9 +19,7 @@ int lfs_filebd_createcfg(lfs_filebd_t *bd, const char *path,
             (void*)bd, path, (void*)cfg,
             cfg->read_size, cfg->prog_size, cfg->erase_size, cfg->erase_count,
             cfg->erase_value);
-
-    // copy over config
-    bd->cfg = *cfg;
+    bd->cfg = cfg;
 
     // open file
     bd->fd = open(path, O_RDWR | O_CREAT, 0666);
@@ -54,18 +52,18 @@ int lfs_filebd_read(lfs_filebd_t *bd, lfs_block_t block,
             (void*)bd, block, off, buffer, size);
 
     // check if read is valid
-    LFS_ASSERT(off  % bd->cfg.read_size == 0);
-    LFS_ASSERT(size % bd->cfg.read_size == 0);
-    LFS_ASSERT(block < bd->cfg.erase_count);
+    LFS_ASSERT(off  % bd->cfg->read_size == 0);
+    LFS_ASSERT(size % bd->cfg->read_size == 0);
+    LFS_ASSERT(block < bd->cfg->erase_count);
 
     // zero for reproducability (in case file is truncated)
-    if (bd->cfg.erase_value != -1) {
-        memset(buffer, bd->cfg.erase_value, size);
+    if (bd->cfg->erase_value != -1) {
+        memset(buffer, bd->cfg->erase_value, size);
     }
 
     // read
     off_t res1 = lseek(bd->fd,
-            (off_t)block*bd->cfg.erase_size + (off_t)off, SEEK_SET);
+            (off_t)block*bd->cfg->erase_size + (off_t)off, SEEK_SET);
     if (res1 < 0) {
         int err = -errno;
         LFS_FILEBD_TRACE("lfs_filebd_read -> %d", err);
@@ -90,14 +88,14 @@ int lfs_filebd_prog(lfs_filebd_t *bd, lfs_block_t block,
             (void*)bd, block, off, buffer, size);
 
     // check if write is valid
-    LFS_ASSERT(off  % bd->cfg.prog_size == 0);
-    LFS_ASSERT(size % bd->cfg.prog_size == 0);
-    LFS_ASSERT(block < bd->cfg.erase_count);
+    LFS_ASSERT(off  % bd->cfg->prog_size == 0);
+    LFS_ASSERT(size % bd->cfg->prog_size == 0);
+    LFS_ASSERT(block < bd->cfg->erase_count);
 
     // check that data was erased? only needed for testing
-    if (bd->cfg.erase_value != -1) {
+    if (bd->cfg->erase_value != -1) {
         off_t res1 = lseek(bd->fd,
-                (off_t)block*bd->cfg.erase_size + (off_t)off, SEEK_SET);
+                (off_t)block*bd->cfg->erase_size + (off_t)off, SEEK_SET);
         if (res1 < 0) {
             int err = -errno;
             LFS_FILEBD_TRACE("lfs_filebd_prog -> %d", err);
@@ -113,13 +111,13 @@ int lfs_filebd_prog(lfs_filebd_t *bd, lfs_block_t block,
                 return err;
             }
 
-            LFS_ASSERT(c == bd->cfg.erase_value);
+            LFS_ASSERT(c == bd->cfg->erase_value);
         }
     }
 
     // program data
     off_t res1 = lseek(bd->fd,
-            (off_t)block*bd->cfg.erase_size + (off_t)off, SEEK_SET);
+            (off_t)block*bd->cfg->erase_size + (off_t)off, SEEK_SET);
     if (res1 < 0) {
         int err = -errno;
         LFS_FILEBD_TRACE("lfs_filebd_prog -> %d", err);
@@ -141,19 +139,19 @@ int lfs_filebd_erase(lfs_filebd_t *bd, lfs_block_t block) {
     LFS_FILEBD_TRACE("lfs_filebd_erase(%p, 0x%"PRIx32")", (void*)bd, block);
 
     // check if erase is valid
-    LFS_ASSERT(block < bd->cfg.erase_count);
+    LFS_ASSERT(block < bd->cfg->erase_count);
 
     // erase, only needed for testing
-    if (bd->cfg.erase_value != -1) {
-        off_t res1 = lseek(bd->fd, (off_t)block*bd->cfg.erase_size, SEEK_SET);
+    if (bd->cfg->erase_value != -1) {
+        off_t res1 = lseek(bd->fd, (off_t)block*bd->cfg->erase_size, SEEK_SET);
         if (res1 < 0) {
             int err = -errno;
             LFS_FILEBD_TRACE("lfs_filebd_erase -> %d", err);
             return err;
         }
 
-        for (lfs_off_t i = 0; i < bd->cfg.erase_size; i++) {
-            ssize_t res2 = write(bd->fd, &(uint8_t){bd->cfg.erase_value}, 1);
+        for (lfs_off_t i = 0; i < bd->cfg->erase_size; i++) {
+            ssize_t res2 = write(bd->fd, &(uint8_t){bd->cfg->erase_value}, 1);
             if (res2 < 0) {
                 int err = -errno;
                 LFS_FILEBD_TRACE("lfs_filebd_erase -> %d", err);
diff --git a/bd/lfs_filebd.h b/bd/lfs_filebd.h
index 98e924b..2861a8b 100644
--- a/bd/lfs_filebd.h
+++ b/bd/lfs_filebd.h
@@ -46,7 +46,7 @@ struct lfs_filebd_cfg {
 // filebd state
 typedef struct lfs_filebd {
     int fd;
-    struct lfs_filebd_cfg cfg;
+    const struct lfs_filebd_cfg *cfg;
 } lfs_filebd_t;
 
 
diff --git a/bd/lfs_rambd.c b/bd/lfs_rambd.c
index c9e78ad..3a443f4 100644
--- a/bd/lfs_rambd.c
+++ b/bd/lfs_rambd.c
@@ -15,15 +15,13 @@ int lfs_rambd_createcfg(lfs_rambd_t *bd,
             (void*)bd, (void*)cfg,
             cfg->read_size, cfg->prog_size, cfg->erase_size, cfg->erase_count,
             cfg->erase_value, cfg->buffer);
-
-    // copy over config
-    bd->cfg = *cfg;
+    bd->cfg = cfg;
 
     // allocate buffer?
-    if (bd->cfg.buffer) {
-        bd->buffer = bd->cfg.buffer;
+    if (bd->cfg->buffer) {
+        bd->buffer = bd->cfg->buffer;
     } else {
-        bd->buffer = lfs_malloc(bd->cfg.erase_size * bd->cfg.erase_count);
+        bd->buffer = lfs_malloc(bd->cfg->erase_size * bd->cfg->erase_count);
         if (!bd->buffer) {
             LFS_RAMBD_TRACE("lfs_rambd_createcfg -> %d", LFS_ERR_NOMEM);
             return LFS_ERR_NOMEM;
@@ -31,9 +29,9 @@ int lfs_rambd_createcfg(lfs_rambd_t *bd,
     }
 
     // zero for reproducability?
-    if (bd->cfg.erase_value != -1) {
-        memset(bd->buffer, bd->cfg.erase_value,
-                bd->cfg.erase_size * bd->cfg.erase_count);
+    if (bd->cfg->erase_value != -1) {
+        memset(bd->buffer, bd->cfg->erase_value,
+                bd->cfg->erase_size * bd->cfg->erase_count);
     }
 
     LFS_RAMBD_TRACE("lfs_rambd_createcfg -> %d", 0);
@@ -43,7 +41,7 @@ int lfs_rambd_createcfg(lfs_rambd_t *bd,
 int lfs_rambd_destroy(lfs_rambd_t *bd) {
     LFS_RAMBD_TRACE("lfs_rambd_destroy(%p)", (void*)bd);
     // clean up memory
-    if (!bd->cfg.buffer) {
+    if (!bd->cfg->buffer) {
         lfs_free(bd->buffer);
     }
     LFS_RAMBD_TRACE("lfs_rambd_destroy -> %d", 0);
@@ -57,12 +55,12 @@ int lfs_rambd_read(lfs_rambd_t *bd, lfs_block_t block,
             (void*)bd, block, off, buffer, size);
 
     // check if read is valid
-    LFS_ASSERT(off  % bd->cfg.read_size == 0);
-    LFS_ASSERT(size % bd->cfg.read_size == 0);
-    LFS_ASSERT(block < bd->cfg.erase_count);
+    LFS_ASSERT(off  % bd->cfg->read_size == 0);
+    LFS_ASSERT(size % bd->cfg->read_size == 0);
+    LFS_ASSERT(block < bd->cfg->erase_count);
 
     // read data
-    memcpy(buffer, &bd->buffer[block*bd->cfg.erase_size + off], size);
+    memcpy(buffer, &bd->buffer[block*bd->cfg->erase_size + off], size);
 
     LFS_RAMBD_TRACE("lfs_rambd_read -> %d", 0);
     return 0;
@@ -75,20 +73,20 @@ int lfs_rambd_prog(lfs_rambd_t *bd, lfs_block_t block,
             (void*)bd, block, off, buffer, size);
 
     // check if write is valid
-    LFS_ASSERT(off  % bd->cfg.prog_size == 0);
-    LFS_ASSERT(size % bd->cfg.prog_size == 0);
-    LFS_ASSERT(block < bd->cfg.erase_count);
+    LFS_ASSERT(off  % bd->cfg->prog_size == 0);
+    LFS_ASSERT(size % bd->cfg->prog_size == 0);
+    LFS_ASSERT(block < bd->cfg->erase_count);
 
     // check that data was erased? only needed for testing
-    if (bd->cfg.erase_value != -1) {
+    if (bd->cfg->erase_value != -1) {
         for (lfs_off_t i = 0; i < size; i++) {
-            LFS_ASSERT(bd->buffer[block*bd->cfg.erase_size + off + i] ==
-                    bd->cfg.erase_value);
+            LFS_ASSERT(bd->buffer[block*bd->cfg->erase_size + off + i] ==
+                    bd->cfg->erase_value);
         }
     }
 
     // program data
-    memcpy(&bd->buffer[block*bd->cfg.erase_size + off], buffer, size);
+    memcpy(&bd->buffer[block*bd->cfg->erase_size + off], buffer, size);
 
     LFS_RAMBD_TRACE("lfs_rambd_prog -> %d", 0);
     return 0;
@@ -98,12 +96,12 @@ int lfs_rambd_erase(lfs_rambd_t *bd, lfs_block_t block) {
     LFS_RAMBD_TRACE("lfs_rambd_erase(%p, 0x%"PRIx32")", (void*)bd, block);
 
     // check if erase is valid
-    LFS_ASSERT(block < bd->cfg.erase_count);
+    LFS_ASSERT(block < bd->cfg->erase_count);
 
     // erase, only needed for testing
-    if (bd->cfg.erase_value != -1) {
-        memset(&bd->buffer[block*bd->cfg.erase_size],
-                bd->cfg.erase_value, bd->cfg.erase_size);
+    if (bd->cfg->erase_value != -1) {
+        memset(&bd->buffer[block*bd->cfg->erase_size],
+                bd->cfg->erase_value, bd->cfg->erase_size);
     }
 
     LFS_RAMBD_TRACE("lfs_rambd_erase -> %d", 0);
diff --git a/bd/lfs_rambd.h b/bd/lfs_rambd.h
index 5627e54..8b3d24b 100644
--- a/bd/lfs_rambd.h
+++ b/bd/lfs_rambd.h
@@ -37,8 +37,9 @@ struct lfs_rambd_cfg {
     // Number of erasable blocks on the device.
     lfs_size_t erase_count;
 
-    // 8-bit erase value to simulate erasing with. -1 indicates no erase
-    // occurs, which is still a valid block device
+    // 8-bit erase value to use for simulating erases. -1 does not simulate
+    // erases, which can speed up testing by avoiding all the extra block-device
+    // operations to store the erase value.
     int32_t erase_value;
 
     // Optional statically allocated buffer for the block device.
@@ -48,7 +49,7 @@ struct lfs_rambd_cfg {
 // rambd state
 typedef struct lfs_rambd {
     uint8_t *buffer;
-    struct lfs_rambd_cfg cfg;
+    const struct lfs_rambd_cfg *cfg;
 } lfs_rambd_t;
 
 
diff --git a/bd/lfs_testbd.c b/bd/lfs_testbd.c
index 5d12a49..6bee3e9 100644
--- a/bd/lfs_testbd.c
+++ b/bd/lfs_testbd.c
@@ -23,17 +23,15 @@ int lfs_testbd_createcfg(lfs_testbd_t *bd, const char *path,
             cfg->erase_value, cfg->erase_cycles,
             cfg->badblock_behavior, cfg->power_cycles,
             cfg->buffer, cfg->wear_buffer);
-
-    // copy over config
-    bd->cfg = *cfg;
+    bd->cfg = cfg;
 
     // setup testing things
     bd->persist = path;
-    bd->power_cycles = bd->cfg.power_cycles;
+    bd->power_cycles = bd->cfg->power_cycles;
 
-    if (bd->cfg.erase_cycles) {
-        if (bd->cfg.wear_buffer) {
-            bd->wear = bd->cfg.wear_buffer;
+    if (bd->cfg->erase_cycles) {
+        if (bd->cfg->wear_buffer) {
+            bd->wear = bd->cfg->wear_buffer;
         } else {
             bd->wear = lfs_malloc(sizeof(lfs_testbd_wear_t)*cfg->erase_count);
             if (!bd->wear) {
@@ -42,29 +40,18 @@ int lfs_testbd_createcfg(lfs_testbd_t *bd, const char *path,
             }
         }
 
-        memset(bd->wear, 0, sizeof(lfs_testbd_wear_t) * bd->cfg.erase_count);
+        memset(bd->wear, 0, sizeof(lfs_testbd_wear_t) * bd->cfg->erase_count);
     }
 
     // create underlying block device
     if (bd->persist) {
         int err = lfs_filebd_createcfg(&bd->impl.filebd, path,
-                &(struct lfs_filebd_cfg){
-                    .read_size=bd->cfg.read_size,
-                    .prog_size=bd->cfg.prog_size,
-                    .erase_size=bd->cfg.erase_size,
-                    .erase_count=bd->cfg.erase_count,
-                    .erase_value=bd->cfg.erase_value});
+                bd->cfg->filebd_cfg);
         LFS_TESTBD_TRACE("lfs_testbd_createcfg -> %d", err);
         return err;
     } else {
         int err = lfs_rambd_createcfg(&bd->impl.rambd,
-                &(struct lfs_rambd_cfg){
-                    .read_size=bd->cfg.read_size,
-                    .prog_size=bd->cfg.prog_size,
-                    .erase_size=bd->cfg.erase_size,
-                    .erase_count=bd->cfg.erase_count,
-                    .erase_value=bd->cfg.erase_value,
-                    .buffer=bd->cfg.buffer});
+                bd->cfg->rambd_cfg);
         LFS_TESTBD_TRACE("lfs_testbd_createcfg -> %d", err);
         return err;
     }
@@ -72,7 +59,7 @@ int lfs_testbd_createcfg(lfs_testbd_t *bd, const char *path,
 
 int lfs_testbd_destroy(lfs_testbd_t *bd) {
     LFS_TESTBD_TRACE("lfs_testbd_destroy(%p)", (void*)bd);
-    if (bd->cfg.erase_cycles && !bd->cfg.wear_buffer) {
+    if (bd->cfg->erase_cycles && !bd->cfg->wear_buffer) {
         lfs_free(bd->wear);
     }
 
@@ -131,13 +118,13 @@ int lfs_testbd_read(lfs_testbd_t *bd, lfs_block_t block,
             (void*)bd, block, off, buffer, size);
 
     // check if read is valid
-    LFS_ASSERT(off  % bd->cfg.read_size == 0);
-    LFS_ASSERT(size % bd->cfg.read_size == 0);
-    LFS_ASSERT(block < bd->cfg.erase_count);
+    LFS_ASSERT(off  % bd->cfg->read_size == 0);
+    LFS_ASSERT(size % bd->cfg->read_size == 0);
+    LFS_ASSERT(block < bd->cfg->erase_count);
 
     // block bad?
-    if (bd->cfg.erase_cycles && bd->wear[block] >= bd->cfg.erase_cycles &&
-            bd->cfg.badblock_behavior == LFS_TESTBD_BADBLOCK_READERROR) {
+    if (bd->cfg->erase_cycles && bd->wear[block] >= bd->cfg->erase_cycles &&
+            bd->cfg->badblock_behavior == LFS_TESTBD_BADBLOCK_READERROR) {
         LFS_TESTBD_TRACE("lfs_testbd_read -> %d", LFS_ERR_CORRUPT);
         return LFS_ERR_CORRUPT;
     }
@@ -155,19 +142,19 @@ int lfs_testbd_prog(lfs_testbd_t *bd, lfs_block_t block,
             (void*)bd, block, off, buffer, size);
 
     // check if write is valid
-    LFS_ASSERT(off  % bd->cfg.prog_size == 0);
-    LFS_ASSERT(size % bd->cfg.prog_size == 0);
-    LFS_ASSERT(block < bd->cfg.erase_count);
+    LFS_ASSERT(off  % bd->cfg->prog_size == 0);
+    LFS_ASSERT(size % bd->cfg->prog_size == 0);
+    LFS_ASSERT(block < bd->cfg->erase_count);
 
     // block bad?
-    if (bd->cfg.erase_cycles && bd->wear[block] >= bd->cfg.erase_cycles) {
-        if (bd->cfg.badblock_behavior ==
+    if (bd->cfg->erase_cycles && bd->wear[block] >= bd->cfg->erase_cycles) {
+        if (bd->cfg->badblock_behavior ==
                 LFS_TESTBD_BADBLOCK_PROGERROR) {
             LFS_TESTBD_TRACE("lfs_testbd_prog -> %d", LFS_ERR_CORRUPT);
             return LFS_ERR_CORRUPT;
-        } else if (bd->cfg.badblock_behavior ==
+        } else if (bd->cfg->badblock_behavior ==
                 LFS_TESTBD_BADBLOCK_PROGNOOP ||
-                bd->cfg.badblock_behavior ==
+                bd->cfg->badblock_behavior ==
                 LFS_TESTBD_BADBLOCK_ERASENOOP) {
             LFS_TESTBD_TRACE("lfs_testbd_prog -> %d", 0);
             return 0;
@@ -200,16 +187,16 @@ int lfs_testbd_erase(lfs_testbd_t *bd, lfs_block_t block) {
     LFS_TESTBD_TRACE("lfs_testbd_erase(%p, 0x%"PRIx32")", (void*)bd, block);
 
     // check if erase is valid
-    LFS_ASSERT(block < bd->cfg.erase_count);
+    LFS_ASSERT(block < bd->cfg->erase_count);
 
     // block bad?
-    if (bd->cfg.erase_cycles) {
-        if (bd->wear[block] >= bd->cfg.erase_cycles) {
-            if (bd->cfg.badblock_behavior ==
+    if (bd->cfg->erase_cycles) {
+        if (bd->wear[block] >= bd->cfg->erase_cycles) {
+            if (bd->cfg->badblock_behavior ==
                     LFS_TESTBD_BADBLOCK_ERASEERROR) {
                 LFS_TESTBD_TRACE("lfs_testbd_erase -> %d", LFS_ERR_CORRUPT);
                 return LFS_ERR_CORRUPT;
-            } else if (bd->cfg.badblock_behavior ==
+            } else if (bd->cfg->badblock_behavior ==
                     LFS_TESTBD_BADBLOCK_ERASENOOP) {
                 LFS_TESTBD_TRACE("lfs_testbd_erase -> %d", 0);
                 return 0;
@@ -256,8 +243,8 @@ lfs_testbd_swear_t lfs_testbd_getwear(lfs_testbd_t *bd,
     LFS_TESTBD_TRACE("lfs_testbd_getwear(%p, %"PRIu32")", (void*)bd, block);
 
     // check if block is valid
-    LFS_ASSERT(bd->cfg.erase_cycles);
-    LFS_ASSERT(block < bd->cfg.erase_count);
+    LFS_ASSERT(bd->cfg->erase_cycles);
+    LFS_ASSERT(block < bd->cfg->erase_count);
 
     LFS_TESTBD_TRACE("lfs_testbd_getwear -> %"PRIu32, bd->wear[block]);
     return bd->wear[block];
@@ -268,8 +255,8 @@ int lfs_testbd_setwear(lfs_testbd_t *bd,
     LFS_TESTBD_TRACE("lfs_testbd_setwear(%p, %"PRIu32")", (void*)bd, block);
 
     // check if block is valid
-    LFS_ASSERT(bd->cfg.erase_cycles);
-    LFS_ASSERT(block < bd->cfg.erase_count);
+    LFS_ASSERT(bd->cfg->erase_cycles);
+    LFS_ASSERT(block < bd->cfg->erase_count);
 
     bd->wear[block] = wear;
 
diff --git a/bd/lfs_testbd.h b/bd/lfs_testbd.h
index d75fb0b..23f3945 100644
--- a/bd/lfs_testbd.h
+++ b/bd/lfs_testbd.h
@@ -44,6 +44,11 @@ typedef int32_t  lfs_testbd_swear_t;
 
 // testbd config, this is required for testing
 struct lfs_testbd_cfg {
+    // Block device specific configuration, see the related config structs.
+    // May be NULL if the underlying implementation goes unused.
+    const struct lfs_rambd_cfg *rambd_cfg;
+    const struct lfs_filebd_cfg *filebd_cfg;
+
     // Minimum size of block read. All read operations must be a
     // multiple of this value.
     lfs_size_t read_size;
@@ -74,9 +79,6 @@ struct lfs_testbd_cfg {
     // the program with exit. Simulates power-loss. 0 disables.
     uint32_t power_cycles;
 
-    // Optional buffer for RAM block device.
-    void *buffer;
-
     // Optional buffer for wear
     void *wear_buffer;
 };
@@ -92,7 +94,7 @@ typedef struct lfs_testbd {
     uint32_t power_cycles;
     lfs_testbd_wear_t *wear;
 
-    struct lfs_testbd_cfg cfg;
+    const struct lfs_testbd_cfg *cfg;
 } lfs_testbd_t;