From 5132f08bd3325602f4de01ccd59537c7f91e1f89 Mon Sep 17 00:00:00 2001 From: André Almeida Date: Mon, 21 Oct 2024 13:37:24 -0300 Subject: tmpfs: Expose filesystem features via sysfs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Expose filesystem features through sysfs, so userspace can query if tmpfs support casefold. This follows the same setup as defined by ext4 and f2fs to expose casefold support to userspace. Signed-off-by: André Almeida Link: https://lore.kernel.org/r/20241021-tonyk-tmpfs-v8-8-f443d5814194@igalia.com Reviewed-by: Gabriel Krisman Bertazi Signed-off-by: Christian Brauner --- mm/shmem.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) (limited to 'mm/shmem.c') diff --git a/mm/shmem.c b/mm/shmem.c index ea01628e4434..0739143d1419 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -5546,3 +5546,40 @@ struct page *shmem_read_mapping_page_gfp(struct address_space *mapping, return page; } EXPORT_SYMBOL_GPL(shmem_read_mapping_page_gfp); + +#if defined(CONFIG_SYSFS) && defined(CONFIG_TMPFS) +#if IS_ENABLED(CONFIG_UNICODE) +static DEVICE_STRING_ATTR_RO(casefold, 0444, "supported"); +#endif + +static struct attribute *tmpfs_attributes[] = { +#if IS_ENABLED(CONFIG_UNICODE) + &dev_attr_casefold.attr.attr, +#endif + NULL +}; + +static const struct attribute_group tmpfs_attribute_group = { + .attrs = tmpfs_attributes, + .name = "features" +}; + +static struct kobject *tmpfs_kobj; + +static int __init tmpfs_sysfs_init(void) +{ + int ret; + + tmpfs_kobj = kobject_create_and_add("tmpfs", fs_kobj); + if (!tmpfs_kobj) + return -ENOMEM; + + ret = sysfs_create_group(tmpfs_kobj, &tmpfs_attribute_group); + if (ret) + kobject_put(tmpfs_kobj); + + return ret; +} + +fs_initcall(tmpfs_sysfs_init); +#endif /* CONFIG_SYSFS && CONFIG_TMPFS */ -- cgit v1.2.3