LCOV - code coverage report
Current view: top level - lkbce/fs/configfs - inode.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 116 135 85.9 %
Date: 2017-01-25 Functions: 10 11 90.9 %

          Line data    Source code
       1             : /* -*- mode: c; c-basic-offset: 8; -*-
       2             :  * vim: noexpandtab sw=8 ts=8 sts=0:
       3             :  *
       4             :  * inode.c - basic inode and dentry operations.
       5             :  *
       6             :  * This program is free software; you can redistribute it and/or
       7             :  * modify it under the terms of the GNU General Public
       8             :  * License as published by the Free Software Foundation; either
       9             :  * version 2 of the License, or (at your option) any later version.
      10             :  *
      11             :  * This program is distributed in the hope that it will be useful,
      12             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      13             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      14             :  * General Public License for more details.
      15             :  *
      16             :  * You should have received a copy of the GNU General Public
      17             :  * License along with this program; if not, write to the
      18             :  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
      19             :  * Boston, MA 021110-1307, USA.
      20             :  *
      21             :  * Based on sysfs:
      22             :  *      sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
      23             :  *
      24             :  * configfs Copyright (C) 2005 Oracle.  All rights reserved.
      25             :  *
      26             :  * Please see Documentation/filesystems/configfs.txt for more information.
      27             :  */
      28             : 
      29             : #undef DEBUG
      30             : 
      31             : #include <linux/pagemap.h>
      32             : #include <linux/namei.h>
      33             : #include <linux/backing-dev.h>
      34             : #include <linux/capability.h>
      35             : #include <linux/sched.h>
      36             : #include <linux/lockdep.h>
      37             : 
      38             : #include <linux/configfs.h>
      39             : #include "configfs_internal.h"
      40             : 
      41             : #ifdef CONFIG_LOCKDEP
      42             : static struct lock_class_key default_group_class[MAX_LOCK_DEPTH];
      43             : #endif
      44             : 
      45             : extern struct super_block * configfs_sb;
      46             : 
      47           1 : static const struct address_space_operations configfs_aops = {
      48             :         .readpage       = simple_readpage,
      49             :         .write_begin    = simple_write_begin,
      50             :         .write_end      = simple_write_end,
      51             : };
      52             : 
      53           1 : static struct backing_dev_info configfs_backing_dev_info = {
      54             :         .name           = "configfs",
      55             :         .ra_pages       = 0,    /* No readahead */
      56             :         .capabilities   = BDI_CAP_NO_ACCT_AND_WRITEBACK,
      57             : };
      58             : 
      59           1 : static const struct inode_operations configfs_inode_operations ={
      60             :         .setattr        = configfs_setattr,
      61             : };
      62             : 
      63             : int configfs_setattr(struct dentry * dentry, struct iattr * iattr)
      64             : {
      65           2 :         struct inode * inode = dentry->d_inode;
      66           3 :         struct configfs_dirent * sd = dentry->d_fsdata;
      67           1 :         struct iattr * sd_iattr;
      68           2 :         unsigned int ia_valid = iattr->ia_valid;
      69           1 :         int error;
      70           1 : 
      71           3 :         if (!sd)
      72           2 :                 return -EINVAL;
      73           1 : 
      74           2 :         sd_iattr = sd->s_iattr;
      75           1 : 
      76           2 :         error = inode_change_ok(inode, iattr);
      77           2 :         if (error)
      78           1 :                 return error;
      79             : 
      80           1 :         error = inode_setattr(inode, iattr);
      81           2 :         if (error)
      82           1 :                 return error;
      83             : 
      84           2 :         if (!sd_iattr) {
      85             :                 /* setting attributes for the first time, allocate now */
      86           3 :                 sd_iattr = kzalloc(sizeof(struct iattr), GFP_KERNEL);
      87           2 :                 if (!sd_iattr)
      88           1 :                         return -ENOMEM;
      89             :                 /* assign default attributes */
      90           1 :                 sd_iattr->ia_mode = sd->s_mode;
      91           1 :                 sd_iattr->ia_uid = 0;
      92           1 :                 sd_iattr->ia_gid = 0;
      93           5 :                 sd_iattr->ia_atime = sd_iattr->ia_mtime = sd_iattr->ia_ctime = CURRENT_TIME;
      94           1 :                 sd->s_iattr = sd_iattr;
      95             :         }
      96             : 
      97             :         /* attributes were changed atleast once in past */
      98             : 
      99           4 :         if (ia_valid & ATTR_UID)
     100           2 :                 sd_iattr->ia_uid = iattr->ia_uid;
     101           4 :         if (ia_valid & ATTR_GID)
     102           2 :                 sd_iattr->ia_gid = iattr->ia_gid;
     103           4 :         if (ia_valid & ATTR_ATIME)
     104           2 :                 sd_iattr->ia_atime = timespec_trunc(iattr->ia_atime,
     105             :                                                 inode->i_sb->s_time_gran);
     106           4 :         if (ia_valid & ATTR_MTIME)
     107           2 :                 sd_iattr->ia_mtime = timespec_trunc(iattr->ia_mtime,
     108             :                                                 inode->i_sb->s_time_gran);
     109           4 :         if (ia_valid & ATTR_CTIME)
     110           2 :                 sd_iattr->ia_ctime = timespec_trunc(iattr->ia_ctime,
     111             :                                                 inode->i_sb->s_time_gran);
     112           4 :         if (ia_valid & ATTR_MODE) {
     113           2 :                 umode_t mode = iattr->ia_mode;
     114             : 
     115          12 :                 if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
     116           2 :                         mode &= ~S_ISGID;
     117           6 :                 sd_iattr->ia_mode = sd->s_mode = mode;
     118             :         }
     119             : 
     120           2 :         return error;
     121             : }
     122             : 
     123             : static inline void set_default_inode_attr(struct inode * inode, mode_t mode)
     124             : {
     125           8 :         inode->i_mode = mode;
     126          24 :         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
     127           4 : }
     128             : 
     129             : static inline void set_inode_attr(struct inode * inode, struct iattr * iattr)
     130             : {
     131           4 :         inode->i_mode = iattr->ia_mode;
     132           4 :         inode->i_uid = iattr->ia_uid;
     133           4 :         inode->i_gid = iattr->ia_gid;
     134           4 :         inode->i_atime = iattr->ia_atime;
     135           4 :         inode->i_mtime = iattr->ia_mtime;
     136           4 :         inode->i_ctime = iattr->ia_ctime;
     137           4 : }
     138             : 
     139             : struct inode * configfs_new_inode(mode_t mode, struct configfs_dirent * sd)
     140             : {
     141          12 :         struct inode * inode = new_inode(configfs_sb);
     142          12 :         if (inode) {
     143           4 :                 inode->i_mapping->a_ops = &configfs_aops;
     144           4 :                 inode->i_mapping->backing_dev_info = &configfs_backing_dev_info;
     145           4 :                 inode->i_op = &configfs_inode_operations;
     146             : 
     147          12 :                 if (sd->s_iattr) {
     148             :                         /* sysfs_dirent has non-default attributes
     149             :                          * get them for the new inode from persistent copy
     150             :                          * in sysfs_dirent
     151             :                          */
     152           8 :                         set_inode_attr(inode, sd->s_iattr);
     153             :                 } else
     154           8 :                         set_default_inode_attr(inode, mode);
     155             :         }
     156          12 :         return inode;
     157             : }
     158             : 
     159             : #ifdef CONFIG_LOCKDEP
     160             : 
     161             : static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
     162             :                                           struct inode *inode)
     163             : {
     164             :         int depth = sd->s_depth;
     165             : 
     166             :         if (depth > 0) {
     167             :                 if (depth <= ARRAY_SIZE(default_group_class)) {
     168             :                         lockdep_set_class(&inode->i_mutex,
     169             :                                           &default_group_class[depth - 1]);
     170             :                 } else {
     171             :                         /*
     172             :                          * In practice the maximum level of locking depth is
     173             :                          * already reached. Just inform about possible reasons.
     174             :                          */
     175             :                         printk(KERN_INFO "configfs: Too many levels of inodes"
     176             :                                " for the locking correctness validator.\n");
     177             :                         printk(KERN_INFO "Spurious warnings may appear.\n");
     178             :                 }
     179             :         }
     180             : }
     181             : 
     182             : #else /* CONFIG_LOCKDEP */
     183             : 
     184             : static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
     185             :                                           struct inode *inode)
     186           4 : {
     187             : }
     188             : 
     189             : #endif /* CONFIG_LOCKDEP */
     190             : 
     191             : int configfs_create(struct dentry * dentry, int mode, int (*init)(struct inode *))
     192             : {
     193           8 :         int error = 0;
     194           8 :         struct inode * inode = NULL;
     195          12 :         if (dentry) {
     196          16 :                 if (!dentry->d_inode) {
     197          12 :                         struct configfs_dirent *sd = dentry->d_fsdata;
     198          24 :                         if ((inode = configfs_new_inode(mode, sd))) {
     199          24 :                                 if (dentry->d_parent && dentry->d_parent->d_inode) {
     200           4 :                                         struct inode *p_inode = dentry->d_parent->d_inode;
     201          12 :                                         p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME;
     202             :                                 }
     203           8 :                                 configfs_set_inode_lock_class(sd, inode);
     204           4 :                                 goto Proceed;
     205             :                         }
     206             :                         else
     207           4 :                                 error = -ENOMEM;
     208             :                 } else
     209           4 :                         error = -EEXIST;
     210             :         } else
     211           4 :                 error = -ENOENT;
     212           8 :         goto Done;
     213           4 : 
     214             :  Proceed:
     215           8 :         if (init)
     216          19 :                 error = init(inode);
     217          16 :         if (!error) {
     218           8 :                 d_instantiate(dentry, inode);
     219          32 :                 if (S_ISDIR(mode) || S_ISLNK(mode))
     220          24 :                         dget(dentry);  /* pin link and directory dentries in core */
     221             :         } else
     222           8 :                 iput(inode);
     223             :  Done:
     224          20 :         return error;
     225          12 : }
     226             : 
     227             : /*
     228             :  * Get the name for corresponding element represented by the given configfs_dirent
     229             :  */
     230             : const unsigned char * configfs_get_name(struct configfs_dirent *sd)
     231             : {
     232           4 :         struct configfs_attribute *attr;
     233           4 : 
     234          56 :         BUG_ON(!sd || !sd->s_element);
     235             : 
     236             :         /* These always have a dentry, so use that */
     237          16 :         if (sd->s_type & (CONFIGFS_DIR | CONFIGFS_ITEM_LINK))
     238           8 :                 return sd->s_dentry->d_name.name;
     239             : 
     240          16 :         if (sd->s_type & CONFIGFS_ITEM_ATTR) {
     241          16 :                 attr = sd->s_element;
     242          16 :                 return attr->ca_name;
     243             :         }
     244           8 :         return NULL;
     245             : }
     246             : 
     247             : 
     248             : /*
     249             :  * Unhashes the dentry corresponding to given configfs_dirent
     250             :  * Called with parent inode's i_mutex held.
     251             :  */
     252             : void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent)
     253             : {
     254          22 :         struct dentry * dentry = sd->s_dentry;
     255          11 : 
     256          22 :         if (dentry) {
     257          22 :                 spin_lock(&dcache_lock);
     258          22 :                 spin_lock(&dentry->d_lock);
     259          77 :                 if (!(d_unhashed(dentry) && dentry->d_inode)) {
     260          11 :                         dget_locked(dentry);
     261          33 :                         __d_drop(dentry);
     262          22 :                         spin_unlock(&dentry->d_lock);
     263          22 :                         spin_unlock(&dcache_lock);
     264          11 :                         simple_unlink(parent->d_inode, dentry);
     265             :                 } else {
     266          22 :                         spin_unlock(&dentry->d_lock);
     267          22 :                         spin_unlock(&dcache_lock);
     268             :                 }
     269             :         }
     270          33 : }
     271             : 
     272             : void configfs_hash_and_remove(struct dentry * dir, const char * name)
     273             : {
     274           0 :         struct configfs_dirent * sd;
     275           0 :         struct configfs_dirent * parent_sd = dir->d_fsdata;
     276           0 : 
     277           0 :         if (dir->d_inode == NULL)
     278           0 :                 /* no inode means this hasn't been made visible yet */
     279           0 :                 return;
     280             : 
     281           0 :         mutex_lock(&dir->d_inode->i_mutex);
     282           0 :         list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
     283           0 :                 if (!sd->s_element)
     284           0 :                         continue;
     285           0 :                 if (!strcmp(configfs_get_name(sd), name)) {
     286           0 :                         spin_lock(&configfs_dirent_lock);
     287           0 :                         list_del_init(&sd->s_sibling);
     288           0 :                         spin_unlock(&configfs_dirent_lock);
     289           0 :                         configfs_drop_dentry(sd, dir);
     290           0 :                         configfs_put(sd);
     291           0 :                         break;
     292             :                 }
     293             :         }
     294           0 :         mutex_unlock(&dir->d_inode->i_mutex);
     295           0 : }
     296             : 
     297             : int __init configfs_inode_init(void)
     298             : {
     299           3 :         return bdi_init(&configfs_backing_dev_info);
     300             : }
     301             : 
     302             : void __exit configfs_inode_exit(void)
     303             : {
     304           2 :         bdi_destroy(&configfs_backing_dev_info);
     305           2 : }

Generated by: LCOV version 1.10