diff options
Diffstat (limited to 'fs/dnotify.c')
| -rw-r--r-- | fs/dnotify.c | 191 |
1 files changed, 0 insertions, 191 deletions
diff --git a/fs/dnotify.c b/fs/dnotify.c deleted file mode 100644 index b0aa2cde80bd..000000000000 --- a/fs/dnotify.c +++ /dev/null @@ -1,191 +0,0 @@ -/* - * Directory notifications for Linux. - * - * Copyright (C) 2000,2001,2002 Stephen Rothwell - * - * 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, 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. - */ -#include <linux/fs.h> -#include <linux/module.h> -#include <linux/sched.h> -#include <linux/dnotify.h> -#include <linux/init.h> -#include <linux/spinlock.h> -#include <linux/slab.h> -#include <linux/fdtable.h> - -int dir_notify_enable __read_mostly = 1; - -static struct kmem_cache *dn_cache __read_mostly; - -static void redo_inode_mask(struct inode *inode) -{ - unsigned long new_mask; - struct dnotify_struct *dn; - - new_mask = 0; - for (dn = inode->i_dnotify; dn != NULL; dn = dn->dn_next) - new_mask |= dn->dn_mask & ~DN_MULTISHOT; - inode->i_dnotify_mask = new_mask; -} - -void dnotify_flush(struct file *filp, fl_owner_t id) -{ - struct dnotify_struct *dn; - struct dnotify_struct **prev; - struct inode *inode; - - inode = filp->f_path.dentry->d_inode; - if (!S_ISDIR(inode->i_mode)) - return; - spin_lock(&inode->i_lock); - prev = &inode->i_dnotify; - while ((dn = *prev) != NULL) { - if ((dn->dn_owner == id) && (dn->dn_filp == filp)) { - *prev = dn->dn_next; - redo_inode_mask(inode); - kmem_cache_free(dn_cache, dn); - break; - } - prev = &dn->dn_next; - } - spin_unlock(&inode->i_lock); -} - -int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg) -{ - struct dnotify_struct *dn; - struct dnotify_struct *odn; - struct dnotify_struct **prev; - struct inode *inode; - fl_owner_t id = current->files; - struct file *f; - int error = 0; - - if ((arg & ~DN_MULTISHOT) == 0) { - dnotify_flush(filp, id); - return 0; - } - if (!dir_notify_enable) - return -EINVAL; - inode = filp->f_path.dentry->d_inode; - if (!S_ISDIR(inode->i_mode)) - return -ENOTDIR; - dn = kmem_cache_alloc(dn_cache, GFP_KERNEL); - if (dn == NULL) - return -ENOMEM; - spin_lock(&inode->i_lock); - prev = &inode->i_dnotify; - while ((odn = *prev) != NULL) { - if ((odn->dn_owner == id) && (odn->dn_filp == filp)) { - odn->dn_fd = fd; - odn->dn_mask |= arg; - inode->i_dnotify_mask |= arg & ~DN_MULTISHOT; - goto out_free; - } - prev = &odn->dn_next; - } - - rcu_read_lock(); - f = fcheck(fd); - rcu_read_unlock(); - /* we'd lost the race with close(), sod off silently */ - /* note that inode->i_lock prevents reordering problems - * between accesses to descriptor table and ->i_dnotify */ - if (f != filp) - goto out_free; - - error = __f_setown(filp, task_pid(current), PIDTYPE_PID, 0); - if (error) - goto out_free; - - dn->dn_mask = arg; - dn->dn_fd = fd; - dn->dn_filp = filp; - dn->dn_owner = id; - inode->i_dnotify_mask |= arg & ~DN_MULTISHOT; - dn->dn_next = inode->i_dnotify; - inode->i_dnotify = dn; - spin_unlock(&inode->i_lock); - return 0; - -out_free: - spin_unlock(&inode->i_lock); - kmem_cache_free(dn_cache, dn); - return error; -} - -void __inode_dir_notify(struct inode *inode, unsigned long event) -{ - struct dnotify_struct * dn; - struct dnotify_struct **prev; - struct fown_struct * fown; - int changed = 0; - - spin_lock(&inode->i_lock); - prev = &inode->i_dnotify; - while ((dn = *prev) != NULL) { - if ((dn->dn_mask & event) == 0) { - prev = &dn->dn_next; - continue; - } - fown = &dn->dn_filp->f_owner; - send_sigio(fown, dn->dn_fd, POLL_MSG); - if (dn->dn_mask & DN_MULTISHOT) - prev = &dn->dn_next; - else { - *prev = dn->dn_next; - changed = 1; - kmem_cache_free(dn_cache, dn); - } - } - if (changed) - redo_inode_mask(inode); - spin_unlock(&inode->i_lock); -} - -EXPORT_SYMBOL(__inode_dir_notify); - -/* - * This is hopelessly wrong, but unfixable without API changes. At - * least it doesn't oops the kernel... - * - * To safely access ->d_parent we need to keep d_move away from it. Use the - * dentry's d_lock for this. - */ -void dnotify_parent(struct dentry *dentry, unsigned long event) -{ - struct dentry *parent; - - if (!dir_notify_enable) - return; - - spin_lock(&dentry->d_lock); - parent = dentry->d_parent; - if (parent->d_inode->i_dnotify_mask & event) { - dget(parent); - spin_unlock(&dentry->d_lock); - __inode_dir_notify(parent->d_inode, event); - dput(parent); - } else { - spin_unlock(&dentry->d_lock); - } -} -EXPORT_SYMBOL_GPL(dnotify_parent); - -static int __init dnotify_init(void) -{ - dn_cache = kmem_cache_create("dnotify_cache", - sizeof(struct dnotify_struct), 0, SLAB_PANIC, NULL); - return 0; -} - -module_init(dnotify_init) |