Fixed read cache amount based on hint and offset

Found by apmorton
Fixed migration test condition for prefix branches
2025-11-01 16:14:13 +01:00 · 2019-05-21 17:21:52 -05:00 · 2019-04-16 18:29:44 -05:00 · 2019-04-16 17:59:28 -05:00 · 2019-04-12 15:21:25 -05:00
2 changed files with 7 additions and 18 deletions
--- a/.travis.yml
+++ b/.travis.yml
@@ -136,6 +136,7 @@ jobs:
      env:
        - STAGE=test
        - NAME=littlefs-migration
+      if: branch !~ -prefix$
      install:
        - sudo apt-get install libfuse-dev
        - git clone --depth 1 https://github.com/geky/littlefs-fuse -b v2-alpha v2
--- a/lfs.c
+++ b/lfs.c
@@ -80,28 +80,16 @@ static int lfs_bd_read(lfs_t *lfs,
            diff = lfs_min(diff, rcache->off-off);
        }

-        if (size >= hint && off % lfs->cfg->read_size == 0 &&
-                size >= lfs->cfg->read_size) {
-            // bypass cache?
-            diff = lfs_aligndown(diff, lfs->cfg->read_size);
-            int err = lfs->cfg->read(lfs->cfg, block, off, data, diff);
-            if (err) {
-                return err;
-            }
-
-            data += diff;
-            off += diff;
-            size -= diff;
-            continue;
-        }
-
        // load to cache, first condition can no longer fail
        LFS_ASSERT(block < lfs->cfg->block_count);
        rcache->block = block;
        rcache->off = lfs_aligndown(off, lfs->cfg->read_size);
-        rcache->size = lfs_min(lfs_alignup(off+hint, lfs->cfg->read_size),
-                lfs_min(lfs->cfg->block_size - rcache->off,
-                    lfs->cfg->cache_size));
+        rcache->size = lfs_min(
+                lfs_min(
+                    lfs_alignup(off+hint, lfs->cfg->read_size),
+                    lfs->cfg->block_size)
+                - rcache->off,
+                lfs->cfg->cache_size);
        int err = lfs->cfg->read(lfs->cfg, rcache->block,
                rcache->off, rcache->buffer, rcache->size);
        if (err) {
Author	SHA1	Message	Date
Christopher Haster	c64bf1a17b	Fixed read cache amount based on hint and offset Found by apmorton	2019-05-21 17:21:52 -05:00
Christopher Haster	f35fb8c148	Fixed migration test condition for prefix branches Both the littlefs-fuse and littlefs-migration test jobs depend on the external littlefs-fuse repo. But unfortunately, the automatic patching to update the external repo with the version under test does not work with the prefix branches. In this case we can just skip these tests, they've already been tested multiple times to get to this point.	2019-04-16 18:29:44 -05:00
Christopher Haster	0a1f706ca2	Merge pull request #160 from FreddieChopin/no-cache-bypass Don't bypass cache in `lfs_cache_prog()` and `lfs_cache_read()`	2019-04-16 17:59:28 -05:00
Freddie Chopin	fdd239fe21	Don't bypass cache in `lfs_cache_prog()` and `lfs_cache_read()` In some cases specific alignment of buffer passed to underlying device is required. For example SDMMC in STM32F7 (when used with DMA) requires the buffers to be aligned to 16 bytes. If you enable data cache in STM32F7, the alignment of buffer passed to any driver which uses DMA should generally be at least 32 bytes. While it is possible to provide sufficiently aligned "read", "prog" and per-file caches to littlefs, the cases where caches are bypassed are hard to control when littlefs is hidden under some additional layers. For example if you couple littlefs with stdio and use it via `FILE`, then littlefs functions will operate on internal `FIlE` buffer, usually allocated dynamically, so in these specific cases - with insufficient alignment (8 bytes on ARM Cortex-M). The easy path was taken - remove all cases of cache bypassing. Fixes #158	2019-04-12 15:21:25 -05:00