Bump default inline_max up to 1/4 block size

As noted by amgross, the current inline_max default (when littlefs
switches from inline files to CTZ skip-lists) does not match the
theoretical value in DESIGN.md.

The reason for this is 1/8 was chosen as a safer default during
development, due to concerns that 1/4 + mdirs splitting at 1/2 would
lead to poor distribution of large inline files in mdirs.

However, two things have happened since then:

1. Experiments have show "wasted" mdir space is less of a concern than
   initially thought. Extra mdir space contributes to logging, delays
   mdir compaction, and can overall lead to better performance.

2. inline_size was added as a configuration option, so if 1/4 is
   problematic users can always override it.

So bumping this back up to 1/4 may make sense.

README.md

@@ -267,11 +267,7 @@ License Identifiers that are here available: http://spdx.org/licenses/
   to create images of the filesystem on your PC. Check if littlefs will fit
   your needs, create images for a later download to the target memory or
   inspect the content of a binary image of the target memory.
-
-- [littlefs-toy] - A command-line tool for creating and working with littlefs
-  images. Uses syntax similar to tar command for ease of use. Supports working
-  on littlefs images embedded inside another file (firmware image, etc).
-
+  
 - [littlefs2-rust] - A Rust wrapper for littlefs. This project allows you
   to use littlefs in a Rust-friendly API, reaping the benefits of Rust's memory
   safety and other guarantees.
@@ -325,7 +321,6 @@ License Identifiers that are here available: http://spdx.org/licenses/
 [littlefs-js]: https://github.com/geky/littlefs-js
 [littlefs-js-demo]:http://littlefs.geky.net/demo.html
 [littlefs-python]: https://pypi.org/project/littlefs-python/
-[littlefs-toy]: https://github.com/tjko/littlefs-toy
 [littlefs2-rust]: https://crates.io/crates/littlefs2
 [nim-littlefs]: https://github.com/Graveflo/nim-littlefs
 [chamelon]: https://github.com/yomimono/chamelon

lfs.c

@@ -93,7 +93,6 @@ static int lfs_bd_read(lfs_t *lfs,
             // bypass cache?
             diff = lfs_aligndown(diff, lfs->cfg->read_size);
             int err = lfs->cfg->read(lfs->cfg, block, off, data, diff);
-            LFS_ASSERT(err <= 0);
             if (err) {
                 return err;
             }
@@ -740,7 +739,6 @@ static lfs_stag_t lfs_dir_getslice(lfs_t *lfs, const lfs_mdir_t *dir,
         int err = lfs_bd_read(lfs,
                 NULL, &lfs->rcache, sizeof(ntag),
                 dir->pair[0], off, &ntag, sizeof(ntag));
-        LFS_ASSERT(err <= 0);
         if (err) {
             return err;
         }
@@ -769,7 +767,6 @@ static lfs_stag_t lfs_dir_getslice(lfs_t *lfs, const lfs_mdir_t *dir,
             err = lfs_bd_read(lfs,
                     NULL, &lfs->rcache, diff,
                     dir->pair[0], off+sizeof(tag)+goff, gbuffer, diff);
-            LFS_ASSERT(err <= 0);
             if (err) {
                 return err;
             }
@@ -1282,7 +1279,6 @@ static lfs_stag_t lfs_dir_fetchmatch(lfs_t *lfs,
                     if (err == LFS_ERR_CORRUPT) {
                         break;
                     }
-                    return err;
                 }
 
                 lfs_fcrc_fromle32(&fcrc);
@@ -2268,7 +2264,7 @@ static int lfs_dir_relocatingcommit(lfs_t *lfs, lfs_mdir_t *dir,
         }
     }
 
-    if (dir->erased && dir->count < 0xff) {
+    if (dir->erased) {
         // try to commit
         struct lfs_commit commit = {
             .block = dir->pair[0],
@@ -4335,7 +4331,7 @@ static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg) {
     LFS_ASSERT(lfs->cfg->inline_max == (lfs_size_t)-1
             || lfs->cfg->inline_max <= ((lfs->cfg->metadata_max)
                 ? lfs->cfg->metadata_max
-                : lfs->cfg->block_size)/8);
+                : lfs->cfg->block_size)/4);
     lfs->inline_max = lfs->cfg->inline_max;
     if (lfs->inline_max == (lfs_size_t)-1) {
         lfs->inline_max = 0;
@@ -4346,7 +4342,7 @@ static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg) {
                     lfs->attr_max,
                     ((lfs->cfg->metadata_max)
                         ? lfs->cfg->metadata_max
-                        : lfs->cfg->block_size)/8));
+                        : lfs->cfg->block_size)/4));
     }
 
     // setup default state

lfs.h

@@ -277,7 +277,7 @@ struct lfs_config {
     // Optional upper limit on inlined files in bytes. Inlined files live in
     // metadata and decrease storage requirements, but may be limited to
     // improve metadata-related performance. Must be <= cache_size, <=
-    // attr_max, and <= block_size/8. Defaults to the largest possible
+    // attr_max, and <= block_size/4. Defaults to the largest possible
     // inline_max when zero.
     //
     // Set to -1 to disable inlined files.