Fix two issues in ExhaustibleBlockDevice #7058
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| @@ -24,6 +24,10 @@ | |||
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| #include "BlockDevice.h" | |||
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| enum { | |||
| BD_ERROR_ERASE_UNIT_WORN_OUT = -3301, | |||
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I'm confused. Why is this an anonymous enum that only has one entry?
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This is an error code specific to exhaustible block device. Followed the convention dictated by existing block devices, like MBRBlockDevice. My understanding is that these error codes are additions to the ones defined in BlockDevice base class.
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👍 I figured as much, but wanted to be sure.
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I think the error should be removed. Real flash will not identify the error.
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Right. The error will be removed as it also breaks the LittleFS wear level test.
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Removed the "worn out" error addition (and fixed the commit message). |
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@mbed-os-storage please review |
| // TODO possibly something more destructive here | ||
| return 0; | ||
| if (_erase_array[addr / eu_size] == 0) { | ||
| return 0; |
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if the erase expands over several sectors and only one of them was exhausted do you stop in the middle of the erase while and not erase the other sectors? Also, is there no error indication for cycles exhausted?
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Regarding the loop exit: Good point, will fix.
Regarding the error indication: This was originally included in the PR (see the strikethrough text in the description) and then I reverted it. Reason was the fact that flash components don't give you an indication for it (you won't get an error, just read the wrong data). In addition, This broke the LittleFS resilience test.
| return err; | ||
| } | ||
| addr += eu_size; | ||
| size -= eu_size; |
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can size become negative and then the while loop wont exit?
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No, this can't happen. The function checks that the erase is valid (at its start), meaning that the erase size is a multiple of the erase unit size, so the scenario you describe can't happen.
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I saw the assert now, thanks
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Pushed a fix with @offirko 's comment (not returning when reaching a worn sector). |
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/morph build |
Build : SUCCESSBuild number : 2350 Triggering tests/morph test |
Exporter Build : SUCCESSBuild number : 1974 |
Test : SUCCESSBuild number : 2135 |
Description
This PR fixes two issues in the exhaustible block device (block device simulating wearing of flash sectors):
1. Return errors when attempting to erase a worn out erase unit or write to it. Current code simply returns 0, without performing the erase/program action, meaning that the failure will be postponed to the time someone attempts to read these values (if at all).2. Support erasing of more than one erase unit, in one call (as current erase API assumes we only erase one erase unit).
Pull request type