From 2322392b020badfe49730f1529b9c1a15248c387 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sat, 23 Nov 2013 17:40:02 -0500 Subject: kernfs: implement "trusted.*" xattr support kernfs inherited "security.*" xattr support from sysfs. This patch extends xattr support to "trusted.*" using simple_xattr_*(). As trusted xattrs are restricted to CAP_SYS_ADMIN, simple_xattr_*() which uses kernel memory for storage shouldn't be problematic. Note that the existing "security.*" support doesn't implement get/remove/list and the this patch only implements those ops for "trusted.*". We probably want to extend those ops to include support for "security.*". This patch will allow using kernfs from cgroup which requires "trusted.*" xattr support. Signed-off-by: Tejun Heo Cc: David P. Quigley Signed-off-by: Greg Kroah-Hartman --- fs/kernfs/inode.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 55 insertions(+), 8 deletions(-) (limited to 'fs/kernfs/inode.c') diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c index a1f83825afca..18ad431e8c2a 100644 --- a/fs/kernfs/inode.c +++ b/fs/kernfs/inode.c @@ -35,6 +35,9 @@ static const struct inode_operations sysfs_inode_operations = { .setattr = sysfs_setattr, .getattr = sysfs_getattr, .setxattr = sysfs_setxattr, + .removexattr = sysfs_removexattr, + .getxattr = sysfs_getxattr, + .listxattr = sysfs_listxattr, }; void __init sysfs_inode_init(void) @@ -61,6 +64,8 @@ static struct sysfs_inode_attrs *sysfs_inode_attrs(struct sysfs_dirent *sd) iattrs->ia_gid = GLOBAL_ROOT_GID; iattrs->ia_atime = iattrs->ia_mtime = iattrs->ia_ctime = CURRENT_TIME; + simple_xattrs_init(&sd->s_iattr->xattrs); + return sd->s_iattr; } @@ -162,23 +167,25 @@ int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags) { struct sysfs_dirent *sd = dentry->d_fsdata; + struct sysfs_inode_attrs *attrs; void *secdata; int error; u32 secdata_len = 0; - if (!sd) - return -EINVAL; + attrs = sysfs_inode_attrs(sd); + if (!attrs) + return -ENOMEM; if (!strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN)) { const char *suffix = name + XATTR_SECURITY_PREFIX_LEN; error = security_inode_setsecurity(dentry->d_inode, suffix, value, size, flags); if (error) - goto out; + return error; error = security_inode_getsecctx(dentry->d_inode, &secdata, &secdata_len); if (error) - goto out; + return error; mutex_lock(&sysfs_mutex); error = sysfs_sd_setsecdata(sd, &secdata, &secdata_len); @@ -186,10 +193,50 @@ int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value, if (secdata) security_release_secctx(secdata, secdata_len); - } else - return -EINVAL; -out: - return error; + return error; + } else if (!strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN)) { + return simple_xattr_set(&attrs->xattrs, name, value, size, + flags); + } + + return -EINVAL; +} + +int sysfs_removexattr(struct dentry *dentry, const char *name) +{ + struct sysfs_dirent *sd = dentry->d_fsdata; + struct sysfs_inode_attrs *attrs; + + attrs = sysfs_inode_attrs(sd); + if (!attrs) + return -ENOMEM; + + return simple_xattr_remove(&attrs->xattrs, name); +} + +ssize_t sysfs_getxattr(struct dentry *dentry, const char *name, void *buf, + size_t size) +{ + struct sysfs_dirent *sd = dentry->d_fsdata; + struct sysfs_inode_attrs *attrs; + + attrs = sysfs_inode_attrs(sd); + if (!attrs) + return -ENOMEM; + + return simple_xattr_get(&attrs->xattrs, name, buf, size); +} + +ssize_t sysfs_listxattr(struct dentry *dentry, char *buf, size_t size) +{ + struct sysfs_dirent *sd = dentry->d_fsdata; + struct sysfs_inode_attrs *attrs; + + attrs = sysfs_inode_attrs(sd); + if (!attrs) + return -ENOMEM; + + return simple_xattr_list(&attrs->xattrs, buf, size); } static inline void set_default_inode_attr(struct inode *inode, umode_t mode) -- cgit v1.2.3