diff options
Diffstat (limited to 'fs/configfs/inode.c')
| -rw-r--r-- | fs/configfs/inode.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/fs/configfs/inode.c b/fs/configfs/inode.c new file mode 100644 index 00000000000..6b274c6d428 --- /dev/null +++ b/fs/configfs/inode.c @@ -0,0 +1,162 @@ +/* -*- 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 <linux/pagemap.h> +#include <linux/namei.h> +#include <linux/backing-dev.h> + +#include <linux/configfs.h> +#include "configfs_internal.h" + +extern struct super_block * configfs_sb; + +static struct address_space_operations configfs_aops = { + .readpage = simple_readpage, + .prepare_write = simple_prepare_write, + .commit_write = simple_commit_write +}; + +static struct backing_dev_info configfs_backing_dev_info = { + .ra_pages = 0, /* No readahead */ + .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK, +}; + +struct inode * configfs_new_inode(mode_t mode) +{ + struct inode * inode = new_inode(configfs_sb); + if (inode) { + inode->i_mode = mode; + inode->i_uid = 0; + inode->i_gid = 0; + inode->i_blksize = PAGE_CACHE_SIZE; + inode->i_blocks = 0; + inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; + inode->i_mapping->a_ops = &configfs_aops; + inode->i_mapping->backing_dev_info = &configfs_backing_dev_info; + } + 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) { + if ((inode = configfs_new_inode(mode))) { + 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 attribute * attr; + + if (!sd || !sd->s_element) + BUG(); + + /* 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->name; + } + return NULL; +} + + +/* + * Unhashes the dentry corresponding to given configfs_dirent + * Called with parent inode's i_sem held. + */ +void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent) +{ + struct dentry * dentry = sd->s_dentry; + + if (dentry) { + spin_lock(&dcache_lock); + if (!(d_unhashed(dentry) && dentry->d_inode)) { + dget_locked(dentry); + __d_drop(dentry); + spin_unlock(&dcache_lock); + simple_unlink(parent->d_inode, dentry); + } else + 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; + + down(&dir->d_inode->i_sem); + list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { + if (!sd->s_element) + continue; + if (!strcmp(configfs_get_name(sd), name)) { + list_del_init(&sd->s_sibling); + configfs_drop_dentry(sd, dir); + configfs_put(sd); + break; + } + } + up(&dir->d_inode->i_sem); +} + + |