Add Dhara FTL Support to LittleFS#7184
Add Dhara FTL Support to LittleFS#7184singh-aditya-04 wants to merge 9 commits intoSamsung:masterfrom
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Add support to littlefs VFS layer to choose the driver based on INODE. For MTD driver select the MTD defined functions otherwise use block device.
Register dhara as block driver on top of MTD device. This block device is used to mount littlfs on /mnt.
Dhara documentation shows that in case of successful read 0 should be returned. But current TizeRT code returns numnber of read.
These changes modifies the format_filesystem function to add support for formatting LittleFS over Dhara (MTD-based filesystem) in addition to the existing block device formatting capabilities.
autoformat not working in case mount fails. memory corruption due to wrong assignment for dhara. causing corruption of dhara structure.
in case nand erase encounter bad block, return eagain and continue erasing other blocks. Also fix return for nand_bread
Two changes are done for this to sync the behaviour between Dhara and littleFS 1) We change littlefs_blocksize from fs->geo.erasesize (128 KB) to fs->geo.blocksize(2 KB). 2) As we are reserving some sectors (pages) for dhara inside files os/fs/driver/mtd/dhara/journal.c and os/fs/driver/mtd/dhara/map.c so we are going to give total pages - reserved pages as available blocks to Littlefs. Signed-off-by: Aditya Singh <aditya.s4@samsung.com> Signed-off-by: Aashish Lakhwara <aashish.l@samsung.com>
We have varified dhara itself manages bad block checking so we do not need mtd to manage bad block checking as it increases flash read operations. Signed-off-by: Aditya Singh <aditya.s4@samsung.com> Signed-off-by: Aashish Lakhwara <aashish.l@samsung.com>
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instead of extern, you should define constant of ioctl, and use driver->u.i_bops->ioctl()
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This need to be checked.
fs->geo.erasesize * fs->geo.neraseblocks is same as size of entire of flash (allocated for littlefs) ?
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So erase size of MTD driver will be asigned.
But ftl will use blocksize of erase (Not erase internally). I mean lfs doesn't care flash is nor or nand. so if nand is attached, then blocksize will be used as a erasesize.
If I am right then geometry of ftl (include dhara) need to be updated.
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if my comment is correct (https://github.com/Samsung/TizenRT/pull/7184/changes#r2910443698)
then this can be removed.
os/fs/driver/mtd/dhara.c
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please remove this line
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updated the PR please check
os/fs/driver/mtd/dhara.c
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please put tab to each of code line.
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updated Please check
os/fs/driver/mtd/dhara.c
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what '64' means exactly? can we change constant value to some kind of formula?
(dev->geo->neraseblocks / dev->geo->blocksize I expect)
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64 represents pages in one bock , sure i will change constant value to some kind of formula
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Updated Please Check
os/fs/driver/mtd/dhara.c
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if (page % 16 == 15)
But let's do not use '16' directly.
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Updated please check
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You reused this code from origin code of dhara. and I think this is implemented wrongly.
Because MTD_BREAD can be failed because of other issue, for example SPI.(of course w25n returns ERROR when status is ECC Fail. so I think we should put some TODO Comment here. I think kind of below logic is required
if (ret < 0) {
dhara_insert_metadatacache(dev, mcache);
if (check_ecc_check_logic) {
dhara_set_error(err, DHARA_E_ECC);
}
return ret;
}
A Metadata Cache based on Most Recently Used Metadata Page has been implemented inside file dhara.c that can be useful for faster page reads. Signed-off-by: Aditya Singh <aditya.s4@samsung.com> Signed-off-by: Aashish Lakhwara <aashish.l@samsung.com>w
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coding rule,
if (((p + 1) % page_per_chunk) == 0) {
2 participants
1) Integrates Dhara FTL with LittleFS filesystem
2) Fix autoformat and memory corruption
3) Fix nand erase to continue if bad block
4) Reduces internal fragmentation of Littlefs with dhara
5) Adds metadata cache for improved read speeds