From 33b091c08ed85e023c21376e6f787355fd46b440 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Almeida?= Date: Fri, 1 Nov 2024 13:42:49 -0300 Subject: [PATCH 1/3] libfs: Fix kernel-doc warning in generic_ci_validate_strict_name MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fix the indentation of the return values from generic_ci_validate_strict_name() to properly render the comment and to address a `make htmldocs` warning: Documentation/filesystems/api-summary:14: include/linux/fs.h:3504: WARNING: Bullet list ends without a blank line; unexpected unindent. Fixes: 0e152beb5aa1 ("libfs: Create the helper function generic_ci_validate_strict_name()") Reported-by: Stephen Rothwell Closes: https://lore.kernel.org/lkml/20241030162435.05425f60@canb.auug.org.au/ Signed-off-by: André Almeida Link: https://lore.kernel.org/r/20241101164251.327884-2-andrealmeid@igalia.com Signed-off-by: Christian Brauner --- include/linux/fs.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/include/linux/fs.h b/include/linux/fs.h index b277369672a1..001d580af862 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3477,12 +3477,12 @@ int generic_ci_d_compare(const struct dentry *dentry, unsigned int len, * @name: name of the new file * * Return: - * * True if the filename is suitable for this directory. It can be - * true if a given name is not suitable for a strict encoding - * directory, but the directory being used isn't strict + * * True: if the filename is suitable for this directory. It can be + * true if a given name is not suitable for a strict encoding + * directory, but the directory being used isn't strict * * False if the filename isn't suitable for this directory. This only - * happens when a directory is casefolded and the filesystem is strict - * about its encoding. + * happens when a directory is casefolded and the filesystem is strict + * about its encoding. */ static inline bool generic_ci_validate_strict_name(struct inode *dir, struct qstr *name) { From 18d2f10f6284f5bb9c03a759044121c71e5b3b4c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Almeida?= Date: Fri, 1 Nov 2024 13:42:50 -0300 Subject: [PATCH 2/3] tmpfs: Fix type for sysfs' casefold attribute MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit DEVICE_STRING_ATTR_RO should be only used by device drivers since it relies on `struct device` to use device_show_string() function. Using this with non device code led to a kCFI violation: > cat /sys/fs/tmpfs/features/casefold [ 70.558496] CFI failure at kobj_attr_show+0x2c/0x4c (target: device_show_string+0x0/0x38; expected type: 0xc527b809) Like the other filesystems, fix this by manually declaring the attribute using kobj_attribute() and writing a proper show() function. Also, leave macros for anyone that need to expand tmpfs sysfs' with more attributes. Fixes: 5132f08bd332 ("tmpfs: Expose filesystem features via sysfs") Reported-by: Nathan Chancellor Closes: https://lore.kernel.org/lkml/20241031051822.GA2947788@thelio-3990X/ Signed-off-by: André Almeida Link: https://lore.kernel.org/r/20241101164251.327884-3-andrealmeid@igalia.com Tested-by: Nathan Chancellor Reviewed-by: Nathan Chancellor Signed-off-by: Christian Brauner --- mm/shmem.c | 29 +++++++++++++++++++++++++++-- 1 file changed, 27 insertions(+), 2 deletions(-) diff --git a/mm/shmem.c b/mm/shmem.c index 0739143d1419..00ff7ef16dc6 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -5548,13 +5548,38 @@ struct page *shmem_read_mapping_page_gfp(struct address_space *mapping, EXPORT_SYMBOL_GPL(shmem_read_mapping_page_gfp); #if defined(CONFIG_SYSFS) && defined(CONFIG_TMPFS) + +#define __INIT_KOBJ_ATTR(_name, _mode, _show, _store) \ +{ \ + .attr = { .name = __stringify(_name), .mode = _mode }, \ + .show = _show, \ + .store = _store, \ +} + +#define TMPFS_ATTR_W(_name, _store) \ + static struct kobj_attribute tmpfs_attr_##_name = \ + __INIT_KOBJ_ATTR(_name, 0200, NULL, _store) + +#define TMPFS_ATTR_RW(_name, _show, _store) \ + static struct kobj_attribute tmpfs_attr_##_name = \ + __INIT_KOBJ_ATTR(_name, 0644, _show, _store) + +#define TMPFS_ATTR_RO(_name, _show) \ + static struct kobj_attribute tmpfs_attr_##_name = \ + __INIT_KOBJ_ATTR(_name, 0444, _show, NULL) + #if IS_ENABLED(CONFIG_UNICODE) -static DEVICE_STRING_ATTR_RO(casefold, 0444, "supported"); +static ssize_t casefold_show(struct kobject *kobj, struct kobj_attribute *a, + char *buf) +{ + return sysfs_emit(buf, "supported\n"); +} +TMPFS_ATTR_RO(casefold, casefold_show); #endif static struct attribute *tmpfs_attributes[] = { #if IS_ENABLED(CONFIG_UNICODE) - &dev_attr_casefold.attr.attr, + &tmpfs_attr_casefold.attr, #endif NULL }; From 65c481f30896750f659345b915b669f78a3c0289 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Almeida?= Date: Fri, 1 Nov 2024 13:42:51 -0300 Subject: [PATCH 3/3] tmpfs: Initialize sysfs during tmpfs init MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Instead of using fs_initcall(), initialize sysfs with the rest of the filesystem. This is the right way to do it because otherwise any error during tmpfs_sysfs_init() would get silently ignored. It's also useful if tmpfs' sysfs ever need to display runtime information. Signed-off-by: André Almeida Link: https://lore.kernel.org/r/20241101164251.327884-4-andrealmeid@igalia.com Signed-off-by: Christian Brauner --- mm/shmem.c | 130 ++++++++++++++++++++++++++++------------------------- 1 file changed, 68 insertions(+), 62 deletions(-) diff --git a/mm/shmem.c b/mm/shmem.c index 00ff7ef16dc6..1389a29a18bf 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -5126,6 +5126,66 @@ static struct file_system_type shmem_fs_type = { .fs_flags = FS_USERNS_MOUNT | FS_ALLOW_IDMAP, }; +#if defined(CONFIG_SYSFS) && defined(CONFIG_TMPFS) + +#define __INIT_KOBJ_ATTR(_name, _mode, _show, _store) \ +{ \ + .attr = { .name = __stringify(_name), .mode = _mode }, \ + .show = _show, \ + .store = _store, \ +} + +#define TMPFS_ATTR_W(_name, _store) \ + static struct kobj_attribute tmpfs_attr_##_name = \ + __INIT_KOBJ_ATTR(_name, 0200, NULL, _store) + +#define TMPFS_ATTR_RW(_name, _show, _store) \ + static struct kobj_attribute tmpfs_attr_##_name = \ + __INIT_KOBJ_ATTR(_name, 0644, _show, _store) + +#define TMPFS_ATTR_RO(_name, _show) \ + static struct kobj_attribute tmpfs_attr_##_name = \ + __INIT_KOBJ_ATTR(_name, 0444, _show, NULL) + +#if IS_ENABLED(CONFIG_UNICODE) +static ssize_t casefold_show(struct kobject *kobj, struct kobj_attribute *a, + char *buf) +{ + return sysfs_emit(buf, "supported\n"); +} +TMPFS_ATTR_RO(casefold, casefold_show); +#endif + +static struct attribute *tmpfs_attributes[] = { +#if IS_ENABLED(CONFIG_UNICODE) + &tmpfs_attr_casefold.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; +} +#endif /* CONFIG_SYSFS && CONFIG_TMPFS */ + void __init shmem_init(void) { int error; @@ -5149,6 +5209,14 @@ void __init shmem_init(void) goto out1; } +#if defined(CONFIG_SYSFS) && defined(CONFIG_TMPFS) + error = tmpfs_sysfs_init(); + if (error) { + pr_err("Could not init tmpfs sysfs\n"); + goto out1; + } +#endif + #ifdef CONFIG_TRANSPARENT_HUGEPAGE if (has_transparent_hugepage() && shmem_huge > SHMEM_HUGE_DENY) SHMEM_SB(shm_mnt->mnt_sb)->huge = shmem_huge; @@ -5546,65 +5614,3 @@ 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) - -#define __INIT_KOBJ_ATTR(_name, _mode, _show, _store) \ -{ \ - .attr = { .name = __stringify(_name), .mode = _mode }, \ - .show = _show, \ - .store = _store, \ -} - -#define TMPFS_ATTR_W(_name, _store) \ - static struct kobj_attribute tmpfs_attr_##_name = \ - __INIT_KOBJ_ATTR(_name, 0200, NULL, _store) - -#define TMPFS_ATTR_RW(_name, _show, _store) \ - static struct kobj_attribute tmpfs_attr_##_name = \ - __INIT_KOBJ_ATTR(_name, 0644, _show, _store) - -#define TMPFS_ATTR_RO(_name, _show) \ - static struct kobj_attribute tmpfs_attr_##_name = \ - __INIT_KOBJ_ATTR(_name, 0444, _show, NULL) - -#if IS_ENABLED(CONFIG_UNICODE) -static ssize_t casefold_show(struct kobject *kobj, struct kobj_attribute *a, - char *buf) -{ - return sysfs_emit(buf, "supported\n"); -} -TMPFS_ATTR_RO(casefold, casefold_show); -#endif - -static struct attribute *tmpfs_attributes[] = { -#if IS_ENABLED(CONFIG_UNICODE) - &tmpfs_attr_casefold.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 */