/*
- * 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/capability.h>
#include <linux/errno.h>
#include <linux/sched.h>
-#include <asm/semaphore.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 const struct inode_operations sysfs_inode_operations ={
.setattr = sysfs_setattr,
};
-void sysfs_delete_inode(struct inode *inode)
+int __init sysfs_inode_init(void)
{
- /* Free the shadowed directory inode operations */
- if (sysfs_is_shadowed_inode(inode)) {
- kfree(inode->i_op);
- inode->i_op = NULL;
- }
- return generic_delete_inode(inode);
+ return bdi_init(&sysfs_backing_dev_info);
}
int sysfs_setattr(struct dentry * dentry, struct iattr * iattr)
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;
-void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode)
+static int sysfs_count_nlink(struct sysfs_dirent *sd)
{
+ 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;
+}
+
+static void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode)
+{
+ 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;
set_inode_attr(inode, sd->s_iattr);
} else
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);
}
/**
- * sysfs_new_inode - allocate new inode for sysfs_dirent
+ * sysfs_get_inode - get inode for sysfs_dirent
* @sd: sysfs_dirent to allocate inode for
*
- * Allocate inode for @sd and initialize basics.
+ * 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.
*/
-struct inode * sysfs_new_inode(struct sysfs_dirent *sd)
+struct inode * sysfs_get_inode(struct sysfs_dirent *sd)
{
struct inode *inode;
- inode = new_inode(sysfs_sb);
- if (inode)
+ inode = iget_locked(sysfs_sb, sd->s_ino);
+ if (inode && (inode->i_state & I_NEW))
sysfs_init_inode(sd, inode);
return inode;
}
-/**
- * sysfs_instantiate - instantiate dentry
- * @dentry: dentry to be instantiated
- * @inode: inode associated with @sd
- *
- * Instantiate @dentry with @inode.
- *
- * LOCKING:
- * None.
- */
-void sysfs_instantiate(struct dentry *dentry, struct inode *inode)
+int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name)
{
- BUG_ON(!dentry || dentry->d_inode);
-
- 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;
- }
-
- d_instantiate(dentry, inode);
-}
+ struct sysfs_addrm_cxt acxt;
+ struct sysfs_dirent *sd;
-/**
- * sysfs_drop_dentry - drop dentry for the specified sysfs_dirent
- * @sd: target sysfs_dirent
- *
- * Drop dentry for @sd. @sd must have been unlinked from its
- * parent on entry to this function such that it can't be looked
- * up anymore.
- *
- * @sd->s_dentry which is protected with sysfs_lock points to the
- * currently associated dentry but we're not holding a reference
- * to it and racing with dput(). Grab dcache_lock and verify
- * dentry before dropping it. If @sd->s_dentry is NULL or dput()
- * beats us, no need to bother.
- */
-void sysfs_drop_dentry(struct sysfs_dirent *sd)
-{
- struct dentry *dentry = NULL, *parent = NULL;
- struct inode *dir;
- struct timespec curtime;
-
- /* We're not holding a reference to ->s_dentry dentry but the
- * field will stay valid as long as sysfs_lock is held.
- */
- spin_lock(&sysfs_lock);
- spin_lock(&dcache_lock);
-
- if (sd->s_dentry && sd->s_dentry->d_inode) {
- /* get dentry if it's there and dput() didn't kill it yet */
- dentry = dget_locked(sd->s_dentry);
- parent = dentry->d_parent;
- } else if (sd->s_parent->s_dentry->d_inode) {
- /* We need to update the parent even if dentry for the
- * victim itself doesn't exist.
- */
- parent = dget_locked(sd->s_parent->s_dentry);
- }
-
- /* drop */
- if (dentry) {
- spin_lock(&dentry->d_lock);
- __d_drop(dentry);
- spin_unlock(&dentry->d_lock);
- }
-
- spin_unlock(&dcache_lock);
- spin_unlock(&sysfs_lock);
-
- /* nothing to do if the parent isn't in dcache */
- if (!parent)
- return;
-
- /* adjust nlink and update timestamp */
- dir = parent->d_inode;
- mutex_lock(&dir->i_mutex);
-
- curtime = CURRENT_TIME;
+ if (!dir_sd)
+ return -ENOENT;
- dir->i_ctime = dir->i_mtime = curtime;
+ sysfs_addrm_start(&acxt, dir_sd);
- if (dentry) {
- dentry->d_inode->i_ctime = curtime;
- drop_nlink(dentry->d_inode);
- if (sd->s_type & SYSFS_DIR) {
- drop_nlink(dentry->d_inode);
- drop_nlink(dir);
- /* XXX: unpin if directory, this will go away soon */
- dput(dentry);
- }
- }
+ sd = sysfs_find_dirent(dir_sd, name);
+ if (sd)
+ sysfs_remove_one(&acxt, sd);
- mutex_unlock(&dir->i_mutex);
+ sysfs_addrm_finish(&acxt);
- /* bye bye */
- if (dentry)
- dput(dentry);
+ if (sd)
+ return 0;
else
- dput(parent);
-}
-
-int sysfs_hash_and_remove(struct dentry * dir, const char * name)
-{
- struct sysfs_dirent * sd;
- struct sysfs_dirent * parent_sd;
- int found = 0;
-
- if (!dir)
- return -ENOENT;
-
- if (dir->d_inode == NULL)
- /* no inode means this hasn't been made visible yet */
return -ENOENT;
-
- parent_sd = dir->d_fsdata;
- mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
- list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
- if (!sd->s_type)
- continue;
- if (!strcmp(sd->s_name, name)) {
- list_del_init(&sd->s_sibling);
- found = 1;
- break;
- }
- }
- mutex_unlock(&dir->d_inode->i_mutex);
-
- if (!found)
- return -ENOENT;
-
- sysfs_drop_dentry(sd);
- sysfs_deactivate(sd);
- sysfs_put(sd);
-
- return 0;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff