kernel/linux.git/drivers/mtd/mtdcore.h, branch v6.18.22

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: 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: Provide fs_context-aware mount_mtd() replacement

2019-09-05T18:34:23+00:00

Provide a function, get_tree_mtd(), to replace mount_mtd(), using an fs_context struct to hold the parameters. Signed-off-by: David Howells cc: David Woodhouse cc: Brian Norris cc: Boris Brezillon cc: Marek Vasut cc: Richard Weinberger cc: linux-mtd@lists.infradead.org Signed-off-by: Al Viro

mtd: Check add_mtd_device() ret code

2019-01-07T13:06:24+00:00

add_mtd_device() can fail. We should always check its return value and gracefully handle the failure case. Fix the call sites where this not done (in mtdpart.c) and add a __must_check attribute to the prototype to avoid this kind of mistakes. Signed-off-by: Boris Brezillon

mtd: move code adding (registering) partitions to the parse_mtd_partitions()

2018-05-07T08:10:47+00:00

This commit slightly simplifies the code. Every parse_mtd_partitions() caller (out of two existing ones) had to add partitions & cleanup parser on its own. This moves that responsibility into the function. That change also allows dropping struct mtd_partitions argument. There is one minor behavior change caused by this cleanup. If parse_mtd_partitions() fails to add partitions (add_mtd_partitions() return an error) then mtd_device_parse_register() will still try to add (register) fallback partitions. It's a real corner case affecting one of uncommon error paths and shouldn't cause any harm. Signed-off-by: Rafał Miłecki Signed-off-by: Boris Brezillon

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

mtd: partitions: support a cleanup callback for parsers

2015-12-09T22:57:44+00:00

If partition parsers need to clean up their resources, we shouldn't assume that all memory will fit in a single kmalloc() that the caller can kfree(). We should allow the parser to provide a proper cleanup routine. Note that this means we need to keep a hold on the parser's module for a bit longer, and release it later with mtd_part_parser_put(). Alongside this, define a default callback that we'll automatically use if the parser doesn't provide one, so we can still retain the old behavior. Signed-off-by: Brian Norris Reviewed-by: Boris Brezillon

mtd: partitions: pass around 'mtd_partitions' wrapper struct

2015-12-09T18:22:09+00:00

For some of the core partitioning code, it helps to keep info about the parsed partition (and who parsed them) together in one place. Signed-off-by: Brian Norris

mtd: partitions: remove kmemdup()

2015-12-09T18:22:06+00:00

The use of kmemdup() complicates the error handling a bit. We don't actually need to allocate new memory, since this reference is treated as const, and it is copied into new memory by the partition registration code anyway. So remove it. Signed-off-by: Brian Norris Reviewed-by: Boris Brezillon