/*
- * inode.c - basic inode and dentry operations.
+ * fs/sysfs/inode.c - basic sysfs inode and dentry operations
*
- * sysfs is Copyright (c) 2001-3 Patrick Mochel
+ * Copyright (c) 2001-3 Patrick Mochel
+ * Copyright (c) 2007 SUSE Linux Products GmbH
+ * Copyright (c) 2007 Tejun Heo <teheo@suse.de>
+ *
+ * This file is released under the GPLv2.
*
* Please see Documentation/filesystems/sysfs.txt for more information.
*/
#include <linux/backing-dev.h>
#include <linux/capability.h>
#include <linux/errno.h>
+#include <linux/sched.h>
#include "sysfs.h"
extern struct super_block * sysfs_sb;
static const struct address_space_operations sysfs_aops = {
.readpage = simple_readpage,
- .prepare_write = simple_prepare_write,
- .commit_write = simple_commit_write
+ .write_begin = simple_write_begin,
+ .write_end = simple_write_end,
};
static struct backing_dev_info sysfs_backing_dev_info = {
.ra_pages = 0, /* No readahead */
- .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
+ .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
};
-static struct inode_operations sysfs_inode_operations ={
+static const struct inode_operations sysfs_inode_operations ={
.setattr = sysfs_setattr,
};
+int __init sysfs_inode_init(void)
+{
+ return bdi_init(&sysfs_backing_dev_info);
+}
+
int sysfs_setattr(struct dentry * dentry, struct iattr * iattr)
{
struct inode * inode = dentry->d_inode;
if (error)
return error;
+ iattr->ia_valid &= ~ATTR_SIZE; /* ignore size changes */
+
error = inode_setattr(inode, iattr);
if (error)
return error;
*/
static struct lock_class_key sysfs_inode_imutex_key;
-struct inode * sysfs_new_inode(mode_t mode, struct sysfs_dirent * sd)
+static int sysfs_count_nlink(struct sysfs_dirent *sd)
{
- struct inode * inode = new_inode(sysfs_sb);
- if (inode) {
- inode->i_blocks = 0;
- inode->i_mapping->a_ops = &sysfs_aops;
- inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info;
- inode->i_op = &sysfs_inode_operations;
- lockdep_set_class(&inode->i_mutex, &sysfs_inode_imutex_key);
-
- 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;
+ struct sysfs_dirent *child;
+ int nr = 0;
+
+ for (child = sd->s_dir.children; child; child = child->s_sibling)
+ if (sysfs_type(child) == SYSFS_DIR)
+ nr++;
+
+ return nr + 2;
}
-int sysfs_create(struct dentry * dentry, int mode, int (*init)(struct inode *))
+static void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode)
{
- int error = 0;
- struct inode * inode = NULL;
- if (dentry) {
- if (!dentry->d_inode) {
- struct sysfs_dirent * sd = dentry->d_fsdata;
- if ((inode = sysfs_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))
- dget(dentry); /* pin only directory dentry in core */
+ struct bin_attribute *bin_attr;
+
+ inode->i_blocks = 0;
+ inode->i_mapping->a_ops = &sysfs_aops;
+ inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info;
+ inode->i_op = &sysfs_inode_operations;
+ inode->i_ino = sd->s_ino;
+ lockdep_set_class(&inode->i_mutex, &sysfs_inode_imutex_key);
+
+ 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
- iput(inode);
- Done:
- return error;
+ set_default_inode_attr(inode, sd->s_mode);
+
+
+ /* initialize inode according to type */
+ switch (sysfs_type(sd)) {
+ case SYSFS_DIR:
+ inode->i_op = &sysfs_dir_inode_operations;
+ inode->i_fop = &sysfs_dir_operations;
+ inode->i_nlink = sysfs_count_nlink(sd);
+ break;
+ case SYSFS_KOBJ_ATTR:
+ inode->i_size = PAGE_SIZE;
+ inode->i_fop = &sysfs_file_operations;
+ break;
+ case SYSFS_KOBJ_BIN_ATTR:
+ bin_attr = sd->s_bin_attr.bin_attr;
+ inode->i_size = bin_attr->size;
+ inode->i_fop = &bin_fops;
+ break;
+ case SYSFS_KOBJ_LINK:
+ inode->i_op = &sysfs_symlink_inode_operations;
+ break;
+ default:
+ BUG();
+ }
+
+ unlock_new_inode(inode);
}
-/*
- * Get the name for corresponding element represented by the given sysfs_dirent
+/**
+ * sysfs_get_inode - get inode for sysfs_dirent
+ * @sd: sysfs_dirent to allocate inode for
+ *
+ * Get inode for @sd. If such inode doesn't exist, a new inode
+ * is allocated and basics are initialized. New inode is
+ * returned locked.
+ *
+ * LOCKING:
+ * Kernel thread context (may sleep).
+ *
+ * RETURNS:
+ * Pointer to allocated inode on success, NULL on failure.
*/
-const unsigned char * sysfs_get_name(struct sysfs_dirent *sd)
+struct inode * sysfs_get_inode(struct sysfs_dirent *sd)
{
- struct attribute * attr;
- struct bin_attribute * bin_attr;
- struct sysfs_symlink * sl;
+ struct inode *inode;
- BUG_ON(!sd || !sd->s_element);
+ inode = iget_locked(sysfs_sb, sd->s_ino);
+ if (inode && (inode->i_state & I_NEW))
+ sysfs_init_inode(sd, inode);
- switch (sd->s_type) {
- case SYSFS_DIR:
- /* Always have a dentry so use that */
- return sd->s_dentry->d_name.name;
-
- case SYSFS_KOBJ_ATTR:
- attr = sd->s_element;
- return attr->name;
-
- case SYSFS_KOBJ_BIN_ATTR:
- bin_attr = sd->s_element;
- return bin_attr->attr.name;
-
- case SYSFS_KOBJ_LINK:
- sl = sd->s_element;
- return sl->link_name;
- }
- return NULL;
-}
-
-
-/*
- * Unhashes the dentry corresponding to given sysfs_dirent
- * Called with parent inode's i_mutex held.
- */
-void sysfs_drop_dentry(struct sysfs_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);
- }
- }
+ return inode;
}
-int sysfs_hash_and_remove(struct dentry * dir, const char * name)
+int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name)
{
- struct sysfs_dirent * sd;
- struct sysfs_dirent * parent_sd;
- int found = 0;
+ struct sysfs_addrm_cxt acxt;
+ struct sysfs_dirent *sd;
- if (!dir)
+ if (!dir_sd)
return -ENOENT;
- if (dir->d_inode == NULL)
- /* no inode means this hasn't been made visible yet */
- return -ENOENT;
+ sysfs_addrm_start(&acxt, dir_sd);
- parent_sd = dir->d_fsdata;
- 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(sysfs_get_name(sd), name)) {
- list_del_init(&sd->s_sibling);
- sysfs_drop_dentry(sd, dir);
- sysfs_put(sd);
- found = 1;
- break;
- }
- }
- mutex_unlock(&dir->d_inode->i_mutex);
+ sd = sysfs_find_dirent(dir_sd, name);
+ if (sd)
+ sysfs_remove_one(&acxt, sd);
- return found ? 0 : -ENOENT;
+ sysfs_addrm_finish(&acxt);
+
+ if (sd)
+ return 0;
+ else
+ return -ENOENT;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff