diff options
Diffstat (limited to 'fs/sysfs')
| -rw-r--r-- | fs/sysfs/dir.c | 1 | ||||
| -rw-r--r-- | fs/sysfs/file.c | 28 | ||||
| -rw-r--r-- | fs/sysfs/group.c | 83 | ||||
| -rw-r--r-- | fs/sysfs/symlink.c | 9 | ||||
| -rw-r--r-- | fs/sysfs/sysfs.h | 2 |
5 files changed, 101 insertions, 22 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 4948d9bc405..a1c3a1fab7f 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -20,6 +20,7 @@ #include <linux/idr.h> #include <linux/completion.h> #include <linux/mutex.h> +#include <linux/slab.h> #include "sysfs.h" DEFINE_MUTEX(sysfs_mutex); diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index a271c87c447..dbdfabbfd60 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -12,6 +12,8 @@ #include <linux/module.h> #include <linux/kobject.h> +#include <linux/kallsyms.h> +#include <linux/slab.h> #include <linux/namei.h> #include <linux/poll.h> #include <linux/list.h> @@ -86,7 +88,12 @@ static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer * The code works fine with PAGE_SIZE return but it's likely to * indicate truncated result or overflow in normal use cases. */ - BUG_ON(count >= (ssize_t)PAGE_SIZE); + if (count >= (ssize_t)PAGE_SIZE) { + print_symbol("fill_read_buffer: %s returned bad count\n", + (unsigned long)ops->show); + /* Try to struggle along */ + count = PAGE_SIZE - 1; + } if (count >= 0) { buffer->needs_read_fill = 0; buffer->count = count; @@ -122,7 +129,7 @@ sysfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos) ssize_t retval = 0; mutex_lock(&buffer->mutex); - if (buffer->needs_read_fill) { + if (buffer->needs_read_fill || *ppos == 0) { retval = fill_read_buffer(file->f_path.dentry,buffer); if (retval) goto out; @@ -403,8 +410,7 @@ static int sysfs_release(struct inode *inode, struct file *filp) * return POLLERR|POLLPRI, and select will return the fd whether * it is waiting for read, write, or exceptions. * Once poll/select indicates that the value has changed, you - * need to close and re-open the file, as simply seeking and reading - * again will not get new data, or reset the state of 'poll'. + * need to close and re-open the file, or seek to 0 and read again. * Reminder: this only works for attributes which actively support * it, and it is not possible to test an attribute from userspace * to see if it supports poll (Neither 'poll' nor 'select' return @@ -471,11 +477,10 @@ const struct file_operations sysfs_file_operations = { .poll = sysfs_poll, }; - -int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, - int type) +int sysfs_add_file_mode(struct sysfs_dirent *dir_sd, + const struct attribute *attr, int type, mode_t amode) { - umode_t mode = (attr->mode & S_IALLUGO) | S_IFREG; + umode_t mode = (amode & S_IALLUGO) | S_IFREG; struct sysfs_addrm_cxt acxt; struct sysfs_dirent *sd; int rc; @@ -496,6 +501,13 @@ int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, } +int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, + int type) +{ + return sysfs_add_file_mode(dir_sd, attr, type, attr->mode); +} + + /** * sysfs_create_file - create an attribute file for an object. * @kobj: object we're creating for. diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c index 47790491503..eeba38417b1 100644 --- a/fs/sysfs/group.c +++ b/fs/sysfs/group.c @@ -23,35 +23,50 @@ static void remove_files(struct sysfs_dirent *dir_sd, struct kobject *kobj, int i; for (i = 0, attr = grp->attrs; *attr; i++, attr++) - if (!grp->is_visible || - grp->is_visible(kobj, *attr, i)) - sysfs_hash_and_remove(dir_sd, (*attr)->name); + sysfs_hash_and_remove(dir_sd, (*attr)->name); } static int create_files(struct sysfs_dirent *dir_sd, struct kobject *kobj, - const struct attribute_group *grp) + const struct attribute_group *grp, int update) { struct attribute *const* attr; int error = 0, i; - for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) - if (!grp->is_visible || - grp->is_visible(kobj, *attr, i)) - error |= - sysfs_add_file(dir_sd, *attr, SYSFS_KOBJ_ATTR); + for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) { + mode_t mode = 0; + + /* in update mode, we're changing the permissions or + * visibility. Do this by first removing then + * re-adding (if required) the file */ + if (update) + sysfs_hash_and_remove(dir_sd, (*attr)->name); + if (grp->is_visible) { + mode = grp->is_visible(kobj, *attr, i); + if (!mode) + continue; + } + error = sysfs_add_file_mode(dir_sd, *attr, SYSFS_KOBJ_ATTR, + (*attr)->mode | mode); + if (unlikely(error)) + break; + } if (error) remove_files(dir_sd, kobj, grp); return error; } -int sysfs_create_group(struct kobject * kobj, - const struct attribute_group * grp) +static int internal_create_group(struct kobject *kobj, int update, + const struct attribute_group *grp) { struct sysfs_dirent *sd; int error; - BUG_ON(!kobj || !kobj->sd); + BUG_ON(!kobj || (!update && !kobj->sd)); + + /* Updates may happen before the object has been instantiated */ + if (unlikely(update && !kobj->sd)) + return -EINVAL; if (grp->name) { error = sysfs_create_subdir(kobj, grp->name, &sd); @@ -60,7 +75,7 @@ int sysfs_create_group(struct kobject * kobj, } else sd = kobj->sd; sysfs_get(sd); - error = create_files(sd, kobj, grp); + error = create_files(sd, kobj, grp, update); if (error) { if (grp->name) sysfs_remove_subdir(sd); @@ -69,6 +84,47 @@ int sysfs_create_group(struct kobject * kobj, return error; } +/** + * sysfs_create_group - given a directory kobject, create an attribute group + * @kobj: The kobject to create the group on + * @grp: The attribute group to create + * + * This function creates a group for the first time. It will explicitly + * warn and error if any of the attribute files being created already exist. + * + * Returns 0 on success or error. + */ +int sysfs_create_group(struct kobject *kobj, + const struct attribute_group *grp) +{ + return internal_create_group(kobj, 0, grp); +} + +/** + * sysfs_update_group - given a directory kobject, create an attribute group + * @kobj: The kobject to create the group on + * @grp: The attribute group to create + * + * This function updates an attribute group. Unlike + * sysfs_create_group(), it will explicitly not warn or error if any + * of the attribute files being created already exist. Furthermore, + * if the visibility of the files has changed through the is_visible() + * callback, it will update the permissions and add or remove the + * relevant files. + * + * The primary use for this function is to call it after making a change + * that affects group visibility. + * + * Returns 0 on success or error. + */ +int sysfs_update_group(struct kobject *kobj, + const struct attribute_group *grp) +{ + return internal_create_group(kobj, 1, grp); +} + + + void sysfs_remove_group(struct kobject * kobj, const struct attribute_group * grp) { @@ -95,4 +151,5 @@ void sysfs_remove_group(struct kobject * kobj, EXPORT_SYMBOL_GPL(sysfs_create_group); +EXPORT_SYMBOL_GPL(sysfs_update_group); EXPORT_SYMBOL_GPL(sysfs_remove_group); diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c index 5f66c446615..817f5966edc 100644 --- a/fs/sysfs/symlink.c +++ b/fs/sysfs/symlink.c @@ -87,7 +87,14 @@ int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char void sysfs_remove_link(struct kobject * kobj, const char * name) { - sysfs_hash_and_remove(kobj->sd, name); + struct sysfs_dirent *parent_sd = NULL; + + if (!kobj) + parent_sd = &sysfs_root; + else + parent_sd = kobj->sd; + + sysfs_hash_and_remove(parent_sd, name); } static int sysfs_get_target_path(struct sysfs_dirent *parent_sd, diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index ff17f8da9b4..ce4e15f8aae 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -154,6 +154,8 @@ extern const struct file_operations sysfs_file_operations; int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, int type); +int sysfs_add_file_mode(struct sysfs_dirent *dir_sd, + const struct attribute *attr, int type, mode_t amode); /* * bin.c */ |