From 1c205ae18db53ff72985dd79f3baaf2dbaba6db7 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Tue, 5 Jan 2010 12:48:01 +0100 Subject: sysfs: Add sysfs_add/remove_files utility functions Adding/Removing a whole array of attributes is very common. Add a standard utility function to do this with a simple function call, instead of requiring drivers to open code this. Signed-off-by: Andi Kleen Signed-off-by: Greg Kroah-Hartman --- include/linux/sysfs.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'include/linux/sysfs.h') diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index cfa83083a2d..3e852658214 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -94,9 +94,12 @@ int __must_check sysfs_move_dir(struct kobject *kobj, int __must_check sysfs_create_file(struct kobject *kobj, const struct attribute *attr); +int __must_check sysfs_create_files(struct kobject *kobj, + const struct attribute **attr); int __must_check sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode); void sysfs_remove_file(struct kobject *kobj, const struct attribute *attr); +void sysfs_remove_files(struct kobject *kobj, const struct attribute **attr); int __must_check sysfs_create_bin_file(struct kobject *kobj, const struct bin_attribute *attr); @@ -164,6 +167,12 @@ static inline int sysfs_create_file(struct kobject *kobj, return 0; } +static inline int sysfs_create_files(struct kobject *kobj, + const struct attribute **attr) +{ + return 0; +} + static inline int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode) { @@ -175,6 +184,11 @@ static inline void sysfs_remove_file(struct kobject *kobj, { } +static inline void sysfs_remove_files(struct kobject *kobj, + const struct attribute **attr) +{ +} + static inline int sysfs_create_bin_file(struct kobject *kobj, const struct bin_attribute *attr) { -- cgit v1.2.3-70-g09d2 From 6992f5334995af474c2b58d010d08bc597f0f2fe Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Thu, 11 Feb 2010 15:21:53 -0800 Subject: sysfs: Use one lockdep class per sysfs attribute. Acknowledge that the logical sysfs rwsem has one instance per sysfs attribute with different locking depencencies for different attributes. There is a sysfs idiom where writing to one sysfs file causes the addition or removal of other sysfs files. Lumping all of the sysfs attributes together in one lock class causes lockdep to generate lots of false positives. This introduces the requirement that non-static sysfs attributes need to be initialized with sysfs_attr_init or sysfs_bin_attr_init. Strictly speaking this requirement only exists when lockdep is enabled, and when lockdep is enabled we get a bit fat warning if this requirement is not met. Signed-off-by: Eric W. Biederman Acked-by: WANG Cong Cc: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/sysfs.h | 7 +++++-- include/linux/sysfs.h | 18 ++++++++++++++++++ 2 files changed, 23 insertions(+), 2 deletions(-) (limited to 'include/linux/sysfs.h') diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 7db6884f420..37e0e086233 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -92,9 +92,12 @@ static inline unsigned int sysfs_type(struct sysfs_dirent *sd) #ifdef CONFIG_DEBUG_LOCK_ALLOC #define sysfs_dirent_init_lockdep(sd) \ do { \ - static struct lock_class_key __key; \ + struct attribute *attr = sd->s_attr.attr; \ + struct lock_class_key *key = attr->key; \ + if (!key) \ + key = &attr->skey; \ \ - lockdep_init_map(&sd->dep_map, "s_active", &__key, 0); \ + lockdep_init_map(&sd->dep_map, "s_active", key, 0); \ } while(0) #else #define sysfs_dirent_init_lockdep(sd) do {} while(0) diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index 3e852658214..006c359e63c 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -15,6 +15,7 @@ #include #include #include +#include #include struct kobject; @@ -29,8 +30,23 @@ struct attribute { const char *name; struct module *owner; mode_t mode; +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lock_class_key *key; + struct lock_class_key skey; +#endif }; +#ifdef CONFIG_DEBUG_LOCK_ALLOC +#define sysfs_attr_init(attr) \ +do { \ + static struct lock_class_key __key; \ + \ + (attr)->key = &__key; \ +} while(0) +#else +#define sysfs_attr_init(attr) do {} while(0) +#endif + struct attribute_group { const char *name; mode_t (*is_visible)(struct kobject *, @@ -74,6 +90,8 @@ struct bin_attribute { struct vm_area_struct *vma); }; +#define sysfs_bin_attr_init(bin_attr) sysfs_attr_init(&bin_attr->attr) + struct sysfs_ops { ssize_t (*show)(struct kobject *, struct attribute *,char *); ssize_t (*store)(struct kobject *,struct attribute *,const char *, size_t); -- cgit v1.2.3-70-g09d2 From 35960258ed388cdcebdb71df35fd5126978ca325 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 12 Feb 2010 04:35:32 -0800 Subject: sysfs: Document sysfs_attr_init and sysfs_bin_attr_init I have added a new requirement to the external sysfs interface that dynamically allocated sysfs attributes must call sysfs_attr_init if lockdep is enabled. For the time being callying sysfs_attr_init is only mandatory if lockdep is enabled, so we can live with a few unconverted instances until we find them all. As this is part of the public interface of sysfs it is a good idea to document these pseudo functions so someone inspeciting the code can find out what has happened. Signed-off-by: Eric W. Biederman Signed-off-by: Greg Kroah-Hartman --- include/linux/sysfs.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'include/linux/sysfs.h') diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index 006c359e63c..5b8f80f5aca 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -36,6 +36,16 @@ struct attribute { #endif }; +/** + * sysfs_attr_init - initialize a dynamically allocated sysfs attribute + * @attr: struct attribute to initialize + * + * Initialize a dynamically allocated struct attribute so we can + * make lockdep happy. This is a new requirement for attributes + * and initially this is only needed when lockdep is enabled. + * Lockdep gives a nice error when your attribute is added to + * sysfs if you don't have this. + */ #ifdef CONFIG_DEBUG_LOCK_ALLOC #define sysfs_attr_init(attr) \ do { \ @@ -90,6 +100,16 @@ struct bin_attribute { struct vm_area_struct *vma); }; +/** + * sysfs_bin_attr_init - initialize a dynamically allocated bin_attribute + * @attr: struct bin_attribute to initialize + * + * Initialize a dynamically allocated struct bin_attribute so we + * can make lockdep happy. This is a new requirement for + * attributes and initially this is only needed when lockdep is + * enabled. Lockdep gives a nice error when your attribute is + * added to sysfs if you don't have this. + */ #define sysfs_bin_attr_init(bin_attr) sysfs_attr_init(&bin_attr->attr) struct sysfs_ops { -- cgit v1.2.3-70-g09d2 From 7cb32942d91a501b2df944928ccc9e6590ab237b Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 12 Feb 2010 19:22:25 -0800 Subject: sysfs: Implement sysfs_rename_link Because of rename ordering problems we occassionally give false warnings about invalid sysfs operations. So using sysfs_rename create a sysfs_rename_link function that doesn't need strange workarounds. Cc: Benjamin Thery Cc: Daniel Lezcano Acked-by: Serge Hallyn Acked-by: Tejun Heo Signed-off-by: Eric W. Biederman Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/symlink.c | 38 ++++++++++++++++++++++++++++++++++++++ include/linux/sysfs.h | 9 +++++++++ 2 files changed, 47 insertions(+) (limited to 'include/linux/sysfs.h') diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c index c5eff49fa41..1b9a3a1e8a1 100644 --- a/fs/sysfs/symlink.c +++ b/fs/sysfs/symlink.c @@ -123,6 +123,44 @@ void sysfs_remove_link(struct kobject * kobj, const char * name) sysfs_hash_and_remove(parent_sd, name); } +/** + * sysfs_rename_link - rename symlink in object's directory. + * @kobj: object we're acting for. + * @targ: object we're pointing to. + * @old: previous name of the symlink. + * @new: new name of the symlink. + * + * A helper function for the common rename symlink idiom. + */ +int sysfs_rename_link(struct kobject *kobj, struct kobject *targ, + const char *old, const char *new) +{ + struct sysfs_dirent *parent_sd, *sd = NULL; + int result; + + if (!kobj) + parent_sd = &sysfs_root; + else + parent_sd = kobj->sd; + + result = -ENOENT; + sd = sysfs_get_dirent(parent_sd, old); + if (!sd) + goto out; + + result = -EINVAL; + if (sysfs_type(sd) != SYSFS_KOBJ_LINK) + goto out; + if (sd->s_symlink.target_sd->s_dir.kobj != targ) + goto out; + + result = sysfs_rename(sd, parent_sd, new); + +out: + sysfs_put(sd); + return result; +} + static int sysfs_get_target_path(struct sysfs_dirent *parent_sd, struct sysfs_dirent *target_sd, char *path) { diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index 5b8f80f5aca..d77cde6d049 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -151,6 +151,9 @@ int __must_check sysfs_create_link_nowarn(struct kobject *kobj, const char *name); void sysfs_remove_link(struct kobject *kobj, const char *name); +int sysfs_rename_link(struct kobject *kobj, struct kobject *target, + const char *old_name, const char *new_name); + int __must_check sysfs_create_group(struct kobject *kobj, const struct attribute_group *grp); int sysfs_update_group(struct kobject *kobj, @@ -255,6 +258,12 @@ static inline void sysfs_remove_link(struct kobject *kobj, const char *name) { } +static inline int sysfs_rename_link(struct kobject *k, struct kobject *t, + const char *old_name, const char *new_name) +{ + return 0; +} + static inline int sysfs_create_group(struct kobject *kobj, const struct attribute_group *grp) { -- cgit v1.2.3-70-g09d2 From 62e877b893e6350c900d381f353aa62ed48dcc97 Mon Sep 17 00:00:00 2001 From: Stephen Rothwell Date: Mon, 1 Mar 2010 20:38:36 +1100 Subject: sysfs: fix for thinko with sysfs_bin_attr_init() After merging the final tree, today's linux-next build (powerpc allyesconfig) failed like this: drivers/pci/pci-sysfs.c: In function 'pci_create_legacy_files': drivers/pci/pci-sysfs.c:645: error: lvalue required as unary '&' operand drivers/pci/pci-sysfs.c:658: error: lvalue required as unary '&' operand Caused by commit "sysfs: Use sysfs_attr_init and sysfs_bin_attr_init on dynamic attributes" interacting with commit "sysfs: Use one lockdep class per sysfs attribute") both from the driver-core tree. Signed-off-by: Stephen Rothwell Cc: "Eric W. Biederman" Signed-off-by: Greg Kroah-Hartman --- drivers/pci/pci-sysfs.c | 4 ++-- include/linux/sysfs.h | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) (limited to 'include/linux/sysfs.h') diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 9fa183cfb0e..de296452c95 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -642,7 +642,7 @@ void pci_create_legacy_files(struct pci_bus *b) if (!b->legacy_io) goto kzalloc_err; - sysfs_bin_attr_init(&b->legacy_io); + sysfs_bin_attr_init(b->legacy_io); b->legacy_io->attr.name = "legacy_io"; b->legacy_io->size = 0xffff; b->legacy_io->attr.mode = S_IRUSR | S_IWUSR; @@ -655,7 +655,7 @@ void pci_create_legacy_files(struct pci_bus *b) goto legacy_io_err; /* Allocated above after the legacy_io struct */ - sysfs_bin_attr_init(&b->legacy_mem); + sysfs_bin_attr_init(b->legacy_mem); b->legacy_mem = b->legacy_io + 1; b->legacy_mem->attr.name = "legacy_mem"; b->legacy_mem->size = 1024*1024; diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index d77cde6d049..f0496b3d181 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -110,7 +110,7 @@ struct bin_attribute { * enabled. Lockdep gives a nice error when your attribute is * added to sysfs if you don't have this. */ -#define sysfs_bin_attr_init(bin_attr) sysfs_attr_init(&bin_attr->attr) +#define sysfs_bin_attr_init(bin_attr) sysfs_attr_init(&(bin_attr)->attr) struct sysfs_ops { ssize_t (*show)(struct kobject *, struct attribute *,char *); -- cgit v1.2.3-70-g09d2