Commit 988d186d authored by Maneesh Soni's avatar Maneesh Soni Committed by Greg Kroah-Hartman
Browse files

[PATCH] sysfs-iattr: add sysfs_setattr 



o This adds ->i_op->setattr VFS method for sysfs inodes. The changed
  attribues are saved in the persistent sysfs_dirent structure as a pointer
  to struct iattr. The struct iattr is allocated only for those sysfs_dirent's
  for which default attributes are getting changed. Thanks to Jon Smirl for
  this suggestion.

Signed-off-by: default avatarManeesh Soni <maneesh@in.ibm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 6fa5c828

fs/sysfs/dir.c

+1 −0
Original line number Diff line number Diff line
@@ -233,6 +233,7 @@ static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry, 


struct inode_operations sysfs_dir_inode_operations = {

	.lookup		= sysfs_lookup,

	.setattr	= sysfs_setattr,

};



static void remove_dir(struct dentry * d)

fs/sysfs/inode.c

+65 −0
Original line number Diff line number Diff line
@@ -26,6 +26,71 @@ static struct backing_dev_info sysfs_backing_dev_info = { 
	.capabilities	= BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,

};



static struct inode_operations sysfs_inode_operations ={

	.setattr	= sysfs_setattr,

};



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

{

	struct inode * inode = dentry->d_inode;

	struct sysfs_dirent * sd = dentry->d_fsdata;

	struct iattr * sd_iattr;

	unsigned int ia_valid = iattr->ia_valid;

	int error;



	if (!sd)

		return -EINVAL;



	sd_iattr = sd->s_iattr;



	error = inode_change_ok(inode, iattr);

	if (error)

		return error;



	error = inode_setattr(inode, iattr);

	if (error)

		return error;



	if (!sd_iattr) {

		/* setting attributes for the first time, allocate now */

		sd_iattr = kmalloc(sizeof(struct iattr), GFP_KERNEL);

		if (!sd_iattr)

			return -ENOMEM;

		/* assign default attributes */

		memset(sd_iattr, 0, sizeof(struct iattr));

		sd_iattr->ia_mode = sd->s_mode;

		sd_iattr->ia_uid = 0;

		sd_iattr->ia_gid = 0;

		sd_iattr->ia_atime = sd_iattr->ia_mtime = sd_iattr->ia_ctime = CURRENT_TIME;

		sd->s_iattr = sd_iattr;

	}



	/* attributes were changed atleast once in past */



	if (ia_valid & ATTR_UID)

		sd_iattr->ia_uid = iattr->ia_uid;

	if (ia_valid & ATTR_GID)

		sd_iattr->ia_gid = iattr->ia_gid;

	if (ia_valid & ATTR_ATIME)

		sd_iattr->ia_atime = timespec_trunc(iattr->ia_atime,

						inode->i_sb->s_time_gran);

	if (ia_valid & ATTR_MTIME)

		sd_iattr->ia_mtime = timespec_trunc(iattr->ia_mtime,

						inode->i_sb->s_time_gran);

	if (ia_valid & ATTR_CTIME)

		sd_iattr->ia_ctime = timespec_trunc(iattr->ia_ctime,

						inode->i_sb->s_time_gran);

	if (ia_valid & ATTR_MODE) {

		umode_t mode = iattr->ia_mode;



		if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))

			mode &= ~S_ISGID;

		sd_iattr->ia_mode = mode;

	}



	return error;

}



struct inode * sysfs_new_inode(mode_t mode)

{

	struct inode * inode = new_inode(sysfs_sb);

fs/sysfs/sysfs.h

+2 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ extern void sysfs_remove_subdir(struct dentry *); 


extern const unsigned char * sysfs_get_name(struct sysfs_dirent *sd);

extern void sysfs_drop_dentry(struct sysfs_dirent *sd, struct dentry *parent);

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



extern struct rw_semaphore sysfs_rename_sem;

extern struct super_block * sysfs_sb;
@@ -75,6 +76,7 @@ static inline void release_sysfs_dirent(struct sysfs_dirent * sd) 
		kobject_put(sl->target_kobj);

		kfree(sl);

	}

	kfree(sd->s_iattr);

	kmem_cache_free(sysfs_dir_cachep, sd);

}

include/linux/sysfs.h

+1 −0
Original line number Diff line number Diff line
@@ -73,6 +73,7 @@ struct sysfs_dirent { 
	int			s_type;

	umode_t			s_mode;

	struct dentry		* s_dentry;

	struct iattr		* s_iattr;

};



#define SYSFS_ROOT		0x0001

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