kernel/linux.git/drivers/mtd/mtdpart.c, branch linux-7.1.y

mtd: Add driver for concatenating devices

2026-02-25T16:34:20+00:00

Introducing CONFIG_MTD_VIRT_CONCAT to separate the legacy flow from the new approach, where only the concatenated partition is registered as an MTD device, while the individual partitions that form it are not registered independently, as they are typically not required by the user. CONFIG_MTD_VIRT_CONCAT is a boolean configuration option that depends on CONFIG_MTD_PARTITIONED_MASTER. When enabled, it allows flash nodes to be exposed as individual MTD devices along with the other partitions. The solution focuses on fixed-partitions description only as it depends on device boundaries. It supports multiple sets of concatenated devices, each comprising two or more partitions. flash@0 { reg = <0>; partitions { compatible = "fixed-partitions"; part0@0 { part-concat-next = <&flash0_part1>; label = "part0_0"; reg = <0x0 0x800000>; }; flash0_part1: part1@800000 { label = "part0_1"; reg = <800000 0x800000>; }; part2@1000000 { part-concat-next = <&flash1_part0>; label = "part0_2"; reg = <0x800000 0x800000>; }; }; }; flash@1 { reg = <1>; partitions { compatible = "fixed-partitions"; flash1_part0: part1@0 { label = "part1_0"; reg = <0x0 0x800000>; }; part1@800000 { label = "part1_1"; reg = <0x800000 0x800000>; }; }; }; The partitions that gets created are flash@0 part0_0-part0_1-concat flash@1 part1_1 part0_2-part1_0-concat Suggested-by: Bernhard Frauendienst Suggested-by: Miquel Raynal Signed-off-by: Amit Kumar Mahapatra Signed-off-by: Luca Ceresoli Signed-off-by: Miquel Raynal

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

mtd: mtdpart: ignore error -ENOENT from parsers on subpartitions

2025-11-17T10:49:47+00:00

Commit 5c2f7727d437 ("mtd: mtdpart: check for subpartitions parsing result") introduced some kind of regression with parser on subpartitions where if a parser emits an error then the entire parsing process from the upper parser fails and partitions are deleted. Not checking for error in subpartitions was originally intended as special parser can emit error also in the case of the partition not correctly init (for example a wiped partition) or special case where the partition should be skipped due to some ENV variables externally provided (from bootloader for example) One example case is the TRX partition where, in the context of a wiped partition, returns a -ENOENT as the trx_magic is not found in the expected TRX header (as the partition is wiped) To better handle this and still keep some kind of error tracking (for example to catch -ENOMEM errors or -EINVAL errors), permit parser on subpartition to emit -ENOENT error, print a debug log and skip them accordingly. This results in giving better tracking of the status of the parser (instead of returning just 0, dropping any kind of signal that there is something wrong with the parser) and to some degree restore the original logic of the subpartitions parse. (worth to notice that some special partition might have all the special header present for the parser and declare 0 partition in it, this is why it would be wrong to simply return 0 in the case of a special partition that is NOT init for the scanning parser) Cc: stable@vger.kernel.org Fixes: 5c2f7727d437 ("mtd: mtdpart: check for subpartitions parsing result") Signed-off-by: Christian Marangi Signed-off-by: Miquel Raynal

Revert "mtd: core: always create master device"

2025-06-18T09:18:23+00:00

The idea behind this patch was to always let a "master" mtd device available to anchor runtime PM. Historically, there was no mtd device representing the whole storage as soon as partitions were coming into play. The introduction of CONFIG_MTD_PARTITIONED_MASTER allowed to keep this "master" device, but was not enabled by default to avoid breaking existing users (otherwise the mtd device numbering would be totally messed up with an off by 1, at least). The approach of adding an mtd_master class on top of partitioned mtd devices is breaking the mtd core in many creative ways, so better think again this approach and revert the faulty changes for now. This reverts commit 0aa7b390fc40a871267a2328bbbefca8b37ad307. Fixes: 0aa7b390fc40 ("mtd: core: always create master device") Tested-by: Guenter Roeck Acked-by: Guenter Roeck Signed-off-by: Miquel Raynal

mtd: core: always create master device

2025-05-13T07:33:57+00:00

Create master device without partition when CONFIG_MTD_PARTITIONED_MASTER flag is unset. This streamlines device tree and allows to anchor runtime power management on master device in all cases. Signed-off-by: Alexander Usyskin Signed-off-by: Miquel Raynal

mtd: mtdpart: Do not supply NULL to printf()

2025-03-18T16:18:19+00:00

GCC compiler is not happy about NULL being supplied as printf() parameter: drivers/mtd/mtdpart.c:693:34: error: ‘%s’ directive argument is null [-Werror=format-overflow=] Move the code after the parser test for NULL, and drop the ternary completely. The user can deduct this since when it's not NULL two messages will be printed. Signed-off-by: Andy Shevchenko Reviewed-by: Zhihao Cheng Signed-off-by: Miquel Raynal

mtd: mtdpart: check for subpartitions parsing result

2023-10-16T08:50:32+00:00

parse_mtd_partitions() may return an error so it should be checked and optionally passed up Signed-off-by: Rafał Miłecki Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20230927202657.27169-1-zajec5@gmail.com

mtd: use refcount to prevent corruption

2023-07-12T11:30:08+00:00

When underlying device is removed mtd core will crash in case user space is holding open handle. Need to use proper refcounting so device is release only when has no users. Signed-off-by: Tomas Winkler Signed-off-by: Alexander Usyskin Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20230620131905.648089-2-alexander.usyskin@intel.com

mtd: mtdpart: Drop useless LIST_HEAD

2023-06-09T15:27:14+00:00

'tmp_list' is unused, so drop it. Signed-off-by: Christophe JAILLET Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/547248195d87d1240d6126d13eb1364b1a0b634d.1685853690.git.christophe.jaillet@wanadoo.fr