From fcbb27b0ec6dcbc5a5108cb8fb19eae64593d204 Mon Sep 17 00:00:00 2001 From: Timothy Pearson Date: Wed, 23 Aug 2017 14:45:25 -0500 Subject: Initial import of modified Linux 2.6.28 tree Original upstream URL: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git | branch linux-2.6.28.y --- fs/configfs/inode.c | 269 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 269 insertions(+) create mode 100644 fs/configfs/inode.c (limited to 'fs/configfs/inode.c') diff --git a/fs/configfs/inode.c b/fs/configfs/inode.c new file mode 100644 index 0000000..4803ccc --- /dev/null +++ b/fs/configfs/inode.c @@ -0,0 +1,269 @@ +/* -*- mode: c; c-basic-offset: 8; -*- + * vim: noexpandtab sw=8 ts=8 sts=0: + * + * inode.c - basic inode and dentry operations. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + * + * Based on sysfs: + * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel + * + * configfs Copyright (C) 2005 Oracle. All rights reserved. + * + * Please see Documentation/filesystems/configfs.txt for more information. + */ + +#undef DEBUG + +#include +#include +#include +#include +#include + +#include +#include "configfs_internal.h" + +extern struct super_block * configfs_sb; + +static const struct address_space_operations configfs_aops = { + .readpage = simple_readpage, + .write_begin = simple_write_begin, + .write_end = simple_write_end, +}; + +static struct backing_dev_info configfs_backing_dev_info = { + .ra_pages = 0, /* No readahead */ + .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK, +}; + +static const struct inode_operations configfs_inode_operations ={ + .setattr = configfs_setattr, +}; + +int configfs_setattr(struct dentry * dentry, struct iattr * iattr) +{ + struct inode * inode = dentry->d_inode; + struct configfs_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 = kzalloc(sizeof(struct iattr), GFP_KERNEL); + if (!sd_iattr) + return -ENOMEM; + /* assign default attributes */ + 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 = sd->s_mode = mode; + } + + return error; +} + +static inline void set_default_inode_attr(struct inode * inode, mode_t mode) +{ + inode->i_mode = mode; + inode->i_uid = 0; + inode->i_gid = 0; + inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; +} + +static inline void set_inode_attr(struct inode * inode, struct iattr * iattr) +{ + inode->i_mode = iattr->ia_mode; + inode->i_uid = iattr->ia_uid; + inode->i_gid = iattr->ia_gid; + inode->i_atime = iattr->ia_atime; + inode->i_mtime = iattr->ia_mtime; + inode->i_ctime = iattr->ia_ctime; +} + +struct inode * configfs_new_inode(mode_t mode, struct configfs_dirent * sd) +{ + struct inode * inode = new_inode(configfs_sb); + if (inode) { + inode->i_blocks = 0; + inode->i_mapping->a_ops = &configfs_aops; + inode->i_mapping->backing_dev_info = &configfs_backing_dev_info; + inode->i_op = &configfs_inode_operations; + + if (sd->s_iattr) { + /* sysfs_dirent has non-default attributes + * get them for the new inode from persistent copy + * in sysfs_dirent + */ + set_inode_attr(inode, sd->s_iattr); + } else + set_default_inode_attr(inode, mode); + } + return inode; +} + +int configfs_create(struct dentry * dentry, int mode, int (*init)(struct inode *)) +{ + int error = 0; + struct inode * inode = NULL; + if (dentry) { + if (!dentry->d_inode) { + struct configfs_dirent *sd = dentry->d_fsdata; + if ((inode = configfs_new_inode(mode, sd))) { + if (dentry->d_parent && dentry->d_parent->d_inode) { + struct inode *p_inode = dentry->d_parent->d_inode; + p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME; + } + goto Proceed; + } + else + error = -ENOMEM; + } else + error = -EEXIST; + } else + error = -ENOENT; + goto Done; + + Proceed: + if (init) + error = init(inode); + if (!error) { + d_instantiate(dentry, inode); + if (S_ISDIR(mode) || S_ISLNK(mode)) + dget(dentry); /* pin link and directory dentries in core */ + } else + iput(inode); + Done: + return error; +} + +/* + * Get the name for corresponding element represented by the given configfs_dirent + */ +const unsigned char * configfs_get_name(struct configfs_dirent *sd) +{ + struct configfs_attribute *attr; + + BUG_ON(!sd || !sd->s_element); + + /* These always have a dentry, so use that */ + if (sd->s_type & (CONFIGFS_DIR | CONFIGFS_ITEM_LINK)) + return sd->s_dentry->d_name.name; + + if (sd->s_type & CONFIGFS_ITEM_ATTR) { + attr = sd->s_element; + return attr->ca_name; + } + return NULL; +} + + +/* + * Unhashes the dentry corresponding to given configfs_dirent + * Called with parent inode's i_mutex held. + */ +void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent) +{ + struct dentry * dentry = sd->s_dentry; + + if (dentry) { + spin_lock(&dcache_lock); + spin_lock(&dentry->d_lock); + if (!(d_unhashed(dentry) && dentry->d_inode)) { + dget_locked(dentry); + __d_drop(dentry); + spin_unlock(&dentry->d_lock); + spin_unlock(&dcache_lock); + simple_unlink(parent->d_inode, dentry); + } else { + spin_unlock(&dentry->d_lock); + spin_unlock(&dcache_lock); + } + } +} + +void configfs_hash_and_remove(struct dentry * dir, const char * name) +{ + struct configfs_dirent * sd; + struct configfs_dirent * parent_sd = dir->d_fsdata; + + if (dir->d_inode == NULL) + /* no inode means this hasn't been made visible yet */ + return; + + mutex_lock(&dir->d_inode->i_mutex); + list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { + if (!sd->s_element) + continue; + if (!strcmp(configfs_get_name(sd), name)) { + spin_lock(&configfs_dirent_lock); + list_del_init(&sd->s_sibling); + spin_unlock(&configfs_dirent_lock); + configfs_drop_dentry(sd, dir); + configfs_put(sd); + break; + } + } + mutex_unlock(&dir->d_inode->i_mutex); +} + +int __init configfs_inode_init(void) +{ + return bdi_init(&configfs_backing_dev_info); +} + +void __exit configfs_inode_exit(void) +{ + bdi_destroy(&configfs_backing_dev_info); +} -- cgit v1.1