diff options
Diffstat (limited to 'fs/attr.c')
-rw-r--r-- | fs/attr.c | 88 |
1 files changed, 38 insertions, 50 deletions
@@ -14,35 +14,53 @@ #include <linux/fcntl.h> #include <linux/security.h> -/* Taken over from the old code... */ - -/* POSIX UID/GID verification for setting inode attributes. */ +/** + * inode_change_ok - check if attribute changes to an inode are allowed + * @inode: inode to check + * @attr: attributes to change + * + * Check if we are allowed to change the attributes contained in @attr + * in the given inode. This includes the normal unix access permission + * checks, as well as checks for rlimits and others. + * + * Should be called as the first thing in ->setattr implementations, + * possibly after taking additional locks. + */ int inode_change_ok(const struct inode *inode, struct iattr *attr) { - int retval = -EPERM; unsigned int ia_valid = attr->ia_valid; + /* + * First check size constraints. These can't be overriden using + * ATTR_FORCE. + */ + if (ia_valid & ATTR_SIZE) { + int error = inode_newsize_ok(inode, attr->ia_size); + if (error) + return error; + } + /* If force is set do it anyway. */ if (ia_valid & ATTR_FORCE) - goto fine; + return 0; /* Make sure a caller can chown. */ if ((ia_valid & ATTR_UID) && (current_fsuid() != inode->i_uid || attr->ia_uid != inode->i_uid) && !capable(CAP_CHOWN)) - goto error; + return -EPERM; /* Make sure caller can chgrp. */ if ((ia_valid & ATTR_GID) && (current_fsuid() != inode->i_uid || (!in_group_p(attr->ia_gid) && attr->ia_gid != inode->i_gid)) && !capable(CAP_CHOWN)) - goto error; + return -EPERM; /* Make sure a caller can chmod. */ if (ia_valid & ATTR_MODE) { if (!is_owner_or_cap(inode)) - goto error; + return -EPERM; /* Also check the setgid bit! */ if (!in_group_p((ia_valid & ATTR_GID) ? attr->ia_gid : inode->i_gid) && !capable(CAP_FSETID)) @@ -52,12 +70,10 @@ int inode_change_ok(const struct inode *inode, struct iattr *attr) /* Check for setting the inode time. */ if (ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) { if (!is_owner_or_cap(inode)) - goto error; + return -EPERM; } -fine: - retval = 0; -error: - return retval; + + return 0; } EXPORT_SYMBOL(inode_change_ok); @@ -105,21 +121,21 @@ out_big: EXPORT_SYMBOL(inode_newsize_ok); /** - * generic_setattr - copy simple metadata updates into the generic inode + * setattr_copy - copy simple metadata updates into the generic inode * @inode: the inode to be updated * @attr: the new attributes * - * generic_setattr must be called with i_mutex held. + * setattr_copy must be called with i_mutex held. * - * generic_setattr updates the inode's metadata with that specified + * setattr_copy updates the inode's metadata with that specified * in attr. Noticably missing is inode size update, which is more complex - * as it requires pagecache updates. See simple_setsize. + * as it requires pagecache updates. * * The inode is not marked as dirty after this operation. The rationale is * that for "simple" filesystems, the struct inode is the inode storage. * The caller is free to mark the inode dirty afterwards if needed. */ -void generic_setattr(struct inode *inode, const struct iattr *attr) +void setattr_copy(struct inode *inode, const struct iattr *attr) { unsigned int ia_valid = attr->ia_valid; @@ -144,32 +160,7 @@ void generic_setattr(struct inode *inode, const struct iattr *attr) inode->i_mode = mode; } } -EXPORT_SYMBOL(generic_setattr); - -/* - * note this function is deprecated, the new truncate sequence should be - * used instead -- see eg. simple_setsize, generic_setattr. - */ -int inode_setattr(struct inode *inode, const struct iattr *attr) -{ - unsigned int ia_valid = attr->ia_valid; - - if (ia_valid & ATTR_SIZE && - attr->ia_size != i_size_read(inode)) { - int error; - - error = vmtruncate(inode, attr->ia_size); - if (error) - return error; - } - - generic_setattr(inode, attr); - - mark_inode_dirty(inode); - - return 0; -} -EXPORT_SYMBOL(inode_setattr); +EXPORT_SYMBOL(setattr_copy); int notify_change(struct dentry * dentry, struct iattr * attr) { @@ -237,13 +228,10 @@ int notify_change(struct dentry * dentry, struct iattr * attr) if (ia_valid & ATTR_SIZE) down_write(&dentry->d_inode->i_alloc_sem); - if (inode->i_op && inode->i_op->setattr) { + if (inode->i_op->setattr) error = inode->i_op->setattr(dentry, attr); - } else { - error = inode_change_ok(inode, attr); - if (!error) - error = inode_setattr(inode, attr); - } + else + error = simple_setattr(dentry, attr); if (ia_valid & ATTR_SIZE) up_write(&dentry->d_inode->i_alloc_sem); |