linux/fs/fat
Javier Martinez Canillas 019a0c9e37 fat: add a vfat_rename2() and make existing .rename callback a helper
Patch series "fat: add support for the renameat2 RENAME_EXCHANGE flag", v6.

The series adds support for the renameat2 system call RENAME_EXCHANGE flag
(which allows to atomically replace two paths) to the vfat filesystem
code.

There are many use cases for this, but we are particularly interested in
making possible for vfat filesystems to be part of OSTree [0] deployments.

Currently OSTree relies on symbolic links to make the deployment updates
an atomic transactional operation.  But RENAME_EXCHANGE could be used [1]
to achieve a similar level of robustness when using a vfat filesystem.

Patch #1 is just a preparatory patch to introduce the RENAME_EXCHANGE
support, patch #2 moves some code blocks in vfat_rename() to a set of
helper functions, that can be reused by tvfat_rename_exchange() that's
added by patch #3 and finally patch #4 adds some kselftests to test it.


This patch (of 4):

Currently vfat only supports the RENAME_NOREPLACE flag which is handled by
the virtual file system layer but doesn't support the RENAME_EXCHANGE
flag.

Add a vfat_rename2() function to be used as the .rename callback and move
the current vfat_rename() handler to a helper.  This is in preparation for
implementing the RENAME_NOREPLACE flag using a different helper function.

Link: https://lkml.kernel.org/r/20220610075721.1182745-1-javierm@redhat.com
Link: https://lkml.kernel.org/r/20220610075721.1182745-2-javierm@redhat.com
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Christian Kellner <ckellner@redhat.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Chung-Chiang Cheng <cccheng@synology.com>
Cc: Lennart Poettering <lennart@poettering.net>
Cc: Alexander Larsson <alexl@redhat.com>
Cc: Colin Walters <walters@verbum.org>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-06-16 19:58:22 -07:00
..
.kunitconfig fat: Add KUnit tests for checksums and timestamps 2021-08-13 13:13:18 -06:00
cache.c fat: new inline functions to determine the FAT variant (32, 16 or 12) 2019-01-04 13:13:47 -08:00
dir.c fat: use pointer to simple type in put_user() 2022-03-23 19:00:34 -07:00
fat_test.c fat: Add KUnit tests for checksums and timestamps 2021-08-13 13:13:18 -06:00
fat.h fat: remove time truncations in vfat_create/vfat_mkdir 2022-05-19 14:10:31 -07:00
fatent.c fat: add ratelimit to fat*_ent_bread() 2022-04-29 14:38:02 -07:00
file.c Not a lot of material this cycle. Many singleton patches against various 2022-05-27 11:22:03 -07:00
inode.c Not a lot of material this cycle. Many singleton patches against various 2022-05-27 11:22:03 -07:00
Kconfig fat: Add KUnit tests for checksums and timestamps 2021-08-13 13:13:18 -06:00
Makefile fat: Add KUnit tests for checksums and timestamps 2021-08-13 13:13:18 -06:00
misc.c fat: remove time truncations in vfat_create/vfat_mkdir 2022-05-19 14:10:31 -07:00
namei_msdos.c fat: handle idmapped mounts 2021-01-24 14:43:46 +01:00
namei_vfat.c fat: add a vfat_rename2() and make existing .rename callback a helper 2022-06-16 19:58:22 -07:00
nfs.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282 2019-06-05 17:36:37 +02:00