Greg KH
2005-06-20T23:26:05Z

[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: Maneesh Soni <maneesh@in.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
commit 988d186de5b6966a71a8cc52e6cb4895fd2f7799
tree 428cb6c29cbe2563eb91f9f2a03512b7eafa9449
parent 6fa5c828c7fb6beef7035864bd2b18e7386fbdd5
author Maneesh Soni <maneesh@in.ibm.com> Tue, 31 May 2005 10:39:14 +0530
committer Greg Kroah-Hartman <gregkh@suse.de> Mon, 20 Jun 2005 15:15:37 -0700

fs/sysfs/dir.c | 1 +
fs/sysfs/inode.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++++
fs/sysfs/sysfs.h | 2 ++
include/linux/sysfs.h | 1 +
4 files changed, 69 insertions(+), 0 deletions(-)

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -233,6 +233,7 @@ static struct dentry * sysfs_lookup(stru

struct inode_operations sysfs_dir_inode_operations = {
.lookup = sysfs_lookup,
+ .setattr = sysfs_setattr,
};

static void remove_dir(struct dentry * d)
diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c
--- a/fs/sysfs/inode.c
+++ b/fs/sysfs/inode.c
@@ -26,6 +26,71 @@ static struct backing_dev_info sysfs_bac
.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);
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -17,6 +17,7 @@ extern void sysfs_remove_subdir(struct d

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(
kobject_put(sl->target_kobj);
kfree(sl);
}
+ kfree(sd->s_iattr);
kmem_cache_free(sysfs_dir_cachep, sd);
}

diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
--- a/include/linux/sysfs.h
+++ b/include/linux/sysfs.h
@@ -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