From 35df63c46c8605d00140ec4833d2104e2e9f1acc Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 20 Nov 2009 16:08:50 -0800 Subject: [PATCH] sysfs: Fix locking and factor out sysfs_sd_setattr Cleanly separate the work that is specific to setting the attributes of a sysfs_dirent from what is needed to update the attributes of a vfs inode. Additionally grab the sysfs_mutex to keep any nasties from surprising us when updating the sysfs_dirent. Acked-by: Tejun Heo Signed-off-by: Eric W. Biederman Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/inode.c | 51 +++++++++++++++++++++++++++++------------------- fs/sysfs/sysfs.h | 1 + 2 files changed, 32 insertions(+), 20 deletions(-) diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index 86fb230de432..76e977c300f7 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -65,30 +65,14 @@ static struct sysfs_inode_attrs *sysfs_init_inode_attrs(struct sysfs_dirent *sd) return attrs; } -int sysfs_setattr(struct dentry * dentry, struct iattr * iattr) +int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr * iattr) { - struct inode * inode = dentry->d_inode; - struct sysfs_dirent * sd = dentry->d_fsdata; struct sysfs_inode_attrs *sd_attrs; struct iattr *iattrs; unsigned int ia_valid = iattr->ia_valid; - int error; - - if (!sd) - return -EINVAL; sd_attrs = sd->s_iattr; - error = inode_change_ok(inode, iattr); - if (error) - return error; - - iattr->ia_valid &= ~ATTR_SIZE; /* ignore size changes */ - - error = inode_setattr(inode, iattr); - if (error) - return error; - if (!sd_attrs) { /* setting attributes for the first time, allocate now */ sd_attrs = sysfs_init_inode_attrs(sd); @@ -111,12 +95,39 @@ int sysfs_setattr(struct dentry * dentry, struct iattr * iattr) iattrs->ia_ctime = iattr->ia_ctime; if (ia_valid & ATTR_MODE) { umode_t mode = iattr->ia_mode; - - if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID)) - mode &= ~S_ISGID; iattrs->ia_mode = sd->s_mode = mode; } } + return 0; +} + +int sysfs_setattr(struct dentry *dentry, struct iattr *iattr) +{ + struct inode *inode = dentry->d_inode; + struct sysfs_dirent *sd = dentry->d_fsdata; + int error; + + if (!sd) + return -EINVAL; + + error = inode_change_ok(inode, iattr); + if (error) + return error; + + iattr->ia_valid &= ~ATTR_SIZE; /* ignore size changes */ + if (iattr->ia_valid & ATTR_MODE) { + if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID)) + iattr->ia_mode &= ~S_ISGID; + } + + error = inode_setattr(inode, iattr); + if (error) + return error; + + mutex_lock(&sysfs_mutex); + error = sysfs_sd_setattr(sd, iattr); + mutex_unlock(&sysfs_mutex); + return error; } diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index af4c4e7482ac..a96d9678ae73 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -155,6 +155,7 @@ 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_setattr(struct dentry *dentry, struct iattr *iattr); int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags); -- 2.20.1