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Commit e61ab4ae authored by Eric W. Biederman's avatar Eric W. Biederman Committed by Greg Kroah-Hartman
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sysfs: Implement sysfs_getattr & sysfs_permission 



With the implementation of sysfs_getattr and sysfs_permission
sysfs becomes able to lazily propogate inode attribute changes
from the sysfs_dirents to the vfs inodes.   This paves the way
for deleting significant chunks of now unnecessary code.

While doing this we did not reference sysfs_setattr from
sysfs_symlink_inode_operations so I added along with
sysfs_getattr and sysfs_permission.

Acked-by: default avatarTejun Heo <tj@kernel.org>
Acked-by: default avatarSerge Hallyn <serue@us.ibm.com>
Signed-off-by: default avatarEric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent c099aacd

fs/sysfs/dir.c

+2 −0
Original line number Diff line number Diff line
@@ -800,7 +800,9 @@ static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry, 


const struct inode_operations sysfs_dir_inode_operations = {

	.lookup		= sysfs_lookup,

	.permission	= sysfs_permission,

	.setattr	= sysfs_setattr,

	.getattr	= sysfs_getattr,

	.setxattr	= sysfs_setxattr,

};

fs/sysfs/inode.c

+47 −17
Original line number Diff line number Diff line
@@ -37,7 +37,9 @@ static struct backing_dev_info sysfs_backing_dev_info = { 
};



static const struct inode_operations sysfs_inode_operations ={

	.permission	= sysfs_permission,

	.setattr	= sysfs_setattr,

	.getattr	= sysfs_getattr,

	.setxattr	= sysfs_setxattr,

};
@@ -196,7 +198,6 @@ static inline void set_default_inode_attr(struct inode * inode, mode_t mode) 


static inline void set_inode_attr(struct inode * inode, struct iattr * iattr)

{

	inode->i_mode = iattr->ia_mode;

	inode->i_uid = iattr->ia_uid;

	inode->i_gid = iattr->ia_gid;

	inode->i_atime = iattr->ia_atime;
@@ -227,38 +228,56 @@ static int sysfs_count_nlink(struct sysfs_dirent *sd) 
	return nr + 2;

}



static void sysfs_refresh_inode(struct sysfs_dirent *sd, struct inode *inode)

{

	struct sysfs_inode_attrs *iattrs = sd->s_iattr;



	inode->i_mode = sd->s_mode;

	if (iattrs) {

		/* sysfs_dirent has non-default attributes

		 * get them from persistent copy in sysfs_dirent

		 */

		set_inode_attr(inode, &iattrs->ia_iattr);

		security_inode_notifysecctx(inode,

					    iattrs->ia_secdata,

					    iattrs->ia_secdata_len);

	}



	if (sysfs_type(sd) == SYSFS_DIR)

		inode->i_nlink = sysfs_count_nlink(sd);

}



int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)

{

	struct sysfs_dirent *sd = dentry->d_fsdata;

	struct inode *inode = dentry->d_inode;



	mutex_lock(&sysfs_mutex);

	sysfs_refresh_inode(sd, inode);

	mutex_unlock(&sysfs_mutex);



	generic_fillattr(inode, stat);

	return 0;

}



static void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode)

{

	struct bin_attribute *bin_attr;

	struct sysfs_inode_attrs *iattrs;



	inode->i_private = sysfs_get(sd);

	inode->i_mapping->a_ops = &sysfs_aops;

	inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info;

	inode->i_op = &sysfs_inode_operations;

	inode->i_ino = sd->s_ino;

	lockdep_set_class(&inode->i_mutex, &sysfs_inode_imutex_key);



	iattrs = sd->s_iattr;

	if (iattrs) {

		/* sysfs_dirent has non-default attributes

		 * get them for the new inode from persistent copy

		 * in sysfs_dirent

		 */

		set_inode_attr(inode, &iattrs->ia_iattr);

		if (iattrs->ia_secdata)

			security_inode_notifysecctx(inode,

						iattrs->ia_secdata,

						iattrs->ia_secdata_len);

	} else

	set_default_inode_attr(inode, sd->s_mode);

	sysfs_refresh_inode(sd, inode);



	/* initialize inode according to type */

	switch (sysfs_type(sd)) {

	case SYSFS_DIR:

		inode->i_op = &sysfs_dir_inode_operations;

		inode->i_fop = &sysfs_dir_operations;

		inode->i_nlink = sysfs_count_nlink(sd);

		break;

	case SYSFS_KOBJ_ATTR:

		inode->i_size = PAGE_SIZE;
@@ -341,3 +360,14 @@ int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name) 
	else

		return -ENOENT;

}



int sysfs_permission(struct inode *inode, int mask)

{

	struct sysfs_dirent *sd = inode->i_private;



	mutex_lock(&sysfs_mutex);

	sysfs_refresh_inode(sd, inode);

	mutex_unlock(&sysfs_mutex);



	return generic_permission(inode, mask, NULL);

}

fs/sysfs/symlink.c

+3 −0
Original line number Diff line number Diff line
@@ -214,6 +214,9 @@ const struct inode_operations sysfs_symlink_inode_operations = { 
	.readlink	= generic_readlink,

	.follow_link	= sysfs_follow_link,

	.put_link	= sysfs_put_link,

	.setattr	= sysfs_setattr,

	.getattr	= sysfs_getattr,

	.permission	= sysfs_permission,

};

fs/sysfs/sysfs.h

+2 −0
Original line number Diff line number Diff line
@@ -156,7 +156,9 @@ static inline void __sysfs_put(struct sysfs_dirent *sd) 
struct inode *sysfs_get_inode(struct sysfs_dirent *sd);

void sysfs_delete_inode(struct inode *inode);

int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr *iattr);

int sysfs_permission(struct inode *inode, int mask);

int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);

int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat);

int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,

		size_t size, int flags);

int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name);