Commit 0eeca283 authored by Robert Love's avatar Robert Love Committed by Linus Torvalds

[PATCH] inotify

inotify is intended to correct the deficiencies of dnotify, particularly
its inability to scale and its terrible user interface:

        * dnotify requires the opening of one fd per each directory
          that you intend to watch. This quickly results in too many
          open files and pins removable media, preventing unmount.
        * dnotify is directory-based. You only learn about changes to
          directories. Sure, a change to a file in a directory affects
          the directory, but you are then forced to keep a cache of
          stat structures.
        * dnotify's interface to user-space is awful.  Signals?

inotify provides a more usable, simple, powerful solution to file change
notification:

        * inotify's interface is a system call that returns a fd, not SIGIO.
	  You get a single fd, which is select()-able.
        * inotify has an event that says "the filesystem that the item
          you were watching is on was unmounted."
        * inotify can watch directories or files.

Inotify is currently used by Beagle (a desktop search infrastructure),
Gamin (a FAM replacement), and other projects.

See Documentation/filesystems/inotify.txt.
Signed-off-by: default avatarRobert Love <rml@novell.com>
Cc: John McCutchan <ttb@tentacle.dhs.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent bd4c625c
inotify
a powerful yet simple file change notification system
Document started 15 Mar 2005 by Robert Love <rml@novell.com>
(i) User Interface
Inotify is controlled by a set of three sys calls
First step in using inotify is to initialise an inotify instance
int fd = inotify_init ();
Change events are managed by "watches". A watch is an (object,mask) pair where
the object is a file or directory and the mask is a bit mask of one or more
inotify events that the application wishes to receive. See <linux/inotify.h>
for valid events. A watch is referenced by a watch descriptor, or wd.
Watches are added via a path to the file.
Watches on a directory will return events on any files inside of the directory.
Adding a watch is simple,
int wd = inotify_add_watch (fd, path, mask);
You can add a large number of files via something like
for each file to watch {
int wd = inotify_add_watch (fd, file, mask);
}
You can update an existing watch in the same manner, by passing in a new mask.
An existing watch is removed via the INOTIFY_IGNORE ioctl, for example
inotify_rm_watch (fd, wd);
Events are provided in the form of an inotify_event structure that is read(2)
from a inotify instance fd. The filename is of dynamic length and follows the
struct. It is of size len. The filename is padded with null bytes to ensure
proper alignment. This padding is reflected in len.
You can slurp multiple events by passing a large buffer, for example
size_t len = read (fd, buf, BUF_LEN);
Will return as many events as are available and fit in BUF_LEN.
each inotify instance fd is also select()- and poll()-able.
You can find the size of the current event queue via the FIONREAD ioctl.
All watches are destroyed and cleaned up on close.
(ii) Internal Kernel Implementation
Each open inotify instance is associated with an inotify_device structure.
Each watch is associated with an inotify_watch structure. Watches are chained
off of each associated device and each associated inode.
See fs/inotify.c for the locking and lifetime rules.
(iii) Rationale
Q: What is the design decision behind not tying the watch to the open fd of
the watched object?
A: Watches are associated with an open inotify device, not an open file.
This solves the primary problem with dnotify: keeping the file open pins
the file and thus, worse, pins the mount. Dnotify is therefore infeasible
for use on a desktop system with removable media as the media cannot be
unmounted.
Q: What is the design decision behind using an-fd-per-device as opposed to
an fd-per-watch?
A: An fd-per-watch quickly consumes more file descriptors than are allowed,
more fd's than are feasible to manage, and more fd's than are optimally
select()-able. Yes, root can bump the per-process fd limit and yes, users
can use epoll, but requiring both is a silly and extraneous requirement.
A watch consumes less memory than an open file, separating the number
spaces is thus sensible. The current design is what user-space developers
want: Users initialize inotify, once, and add n watches, requiring but one fd
and no twiddling with fd limits. Initializing an inotify instance two
thousand times is silly. If we can implement user-space's preferences
cleanly--and we can, the idr layer makes stuff like this trivial--then we
should.
There are other good arguments. With a single fd, there is a single
item to block on, which is mapped to a single queue of events. The single
fd returns all watch events and also any potential out-of-band data. If
every fd was a separate watch,
- There would be no way to get event ordering. Events on file foo and
file bar would pop poll() on both fd's, but there would be no way to tell
which happened first. A single queue trivially gives you ordering. Such
ordering is crucial to existing applications such as Beagle. Imagine
"mv a b ; mv b a" events without ordering.
- We'd have to maintain n fd's and n internal queues with state,
versus just one. It is a lot messier in the kernel. A single, linear
queue is the data structure that makes sense.
- User-space developers prefer the current API. The Beagle guys, for
example, love it. Trust me, I asked. It is not a surprise: Who'd want
to manage and block on 1000 fd's via select?
- You'd have to manage the fd's, as an example: Call close() when you
received a delete event.
- No way to get out of band data.
- 1024 is still too low. ;-)
When you talk about designing a file change notification system that
scales to 1000s of directories, juggling 1000s of fd's just does not seem
the right interface. It is too heavy.
Q: Why the system call approach?
A: The poor user-space interface is the second biggest problem with dnotify.
Signals are a terrible, terrible interface for file notification. Or for
anything, for that matter. The ideal solution, from all perspectives, is a
file descriptor-based one that allows basic file I/O and poll/select.
Obtaining the fd and managing the watches could have been done either via a
device file or a family of new system calls. We decided to implement a
family of system calls because that is the preffered approach for new kernel
features and it means our user interface requirements.
Additionally, it _is_ possible to more than one instance and
juggle more than one queue and thus more than one associated fd.
......@@ -291,3 +291,6 @@ ENTRY(sys_call_table)
.long sys_keyctl
.long sys_ioprio_set
.long sys_ioprio_get /* 290 */
.long sys_inotify_init
.long sys_inotify_add_watch
.long sys_inotify_rm_watch
......@@ -359,6 +359,19 @@ config ROMFS_FS
If you don't know whether you need it, then you don't need it:
answer N.
config INOTIFY
bool "Inotify file change notification support"
default y
---help---
Say Y here to enable inotify support and the /dev/inotify character
device. Inotify is a file change notification system and a
replacement for dnotify. Inotify fixes numerous shortcomings in
dnotify and introduces several new features. It allows monitoring
of both files and directories via a single open fd. Multiple file
events are supported.
If unsure, say Y.
config QUOTA
bool "Quota support"
help
......
......@@ -12,6 +12,7 @@ obj-y := open.o read_write.o file_table.o buffer.o bio.o super.o \
seq_file.o xattr.o libfs.o fs-writeback.o mpage.o direct-io.o \
ioprio.o
obj-$(CONFIG_INOTIFY) += inotify.o
obj-$(CONFIG_EPOLL) += eventpoll.o
obj-$(CONFIG_COMPAT) += compat.o
......
......@@ -10,7 +10,7 @@
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/smp_lock.h>
#include <linux/dnotify.h>
#include <linux/fsnotify.h>
#include <linux/fcntl.h>
#include <linux/quotaops.h>
#include <linux/security.h>
......@@ -107,31 +107,8 @@ int inode_setattr(struct inode * inode, struct iattr * attr)
out:
return error;
}
EXPORT_SYMBOL(inode_setattr);
int setattr_mask(unsigned int ia_valid)
{
unsigned long dn_mask = 0;
if (ia_valid & ATTR_UID)
dn_mask |= DN_ATTRIB;
if (ia_valid & ATTR_GID)
dn_mask |= DN_ATTRIB;
if (ia_valid & ATTR_SIZE)
dn_mask |= DN_MODIFY;
/* both times implies a utime(s) call */
if ((ia_valid & (ATTR_ATIME|ATTR_MTIME)) == (ATTR_ATIME|ATTR_MTIME))
dn_mask |= DN_ATTRIB;
else if (ia_valid & ATTR_ATIME)
dn_mask |= DN_ACCESS;
else if (ia_valid & ATTR_MTIME)
dn_mask |= DN_MODIFY;
if (ia_valid & ATTR_MODE)
dn_mask |= DN_ATTRIB;
return dn_mask;
}
int notify_change(struct dentry * dentry, struct iattr * attr)
{
struct inode *inode = dentry->d_inode;
......@@ -197,11 +174,9 @@ int notify_change(struct dentry * dentry, struct iattr * attr)
if (ia_valid & ATTR_SIZE)
up_write(&dentry->d_inode->i_alloc_sem);
if (!error) {
unsigned long dn_mask = setattr_mask(ia_valid);
if (dn_mask)
dnotify_parent(dentry, dn_mask);
}
if (!error)
fsnotify_change(dentry, ia_valid);
return error;
}
......
......@@ -37,7 +37,7 @@
#include <linux/ctype.h>
#include <linux/module.h>
#include <linux/dirent.h>
#include <linux/dnotify.h>
#include <linux/fsnotify.h>
#include <linux/highuid.h>
#include <linux/sunrpc/svc.h>
#include <linux/nfsd/nfsd.h>
......@@ -1307,9 +1307,13 @@ static ssize_t compat_do_readv_writev(int type, struct file *file,
out:
if (iov != iovstack)
kfree(iov);
if ((ret + (type == READ)) > 0)
dnotify_parent(file->f_dentry,
(type == READ) ? DN_ACCESS : DN_MODIFY);
if ((ret + (type == READ)) > 0) {
struct dentry *dentry = file->f_dentry;
if (type == READ)
fsnotify_access(dentry);
else
fsnotify_modify(dentry);
}
return ret;
}
......
......@@ -16,6 +16,7 @@
#include <linux/eventpoll.h>
#include <linux/mount.h>
#include <linux/cdev.h>
#include <linux/fsnotify.h>
/* sysctl tunables... */
struct files_stat_struct files_stat = {
......@@ -126,6 +127,8 @@ void fastcall __fput(struct file *file)
struct inode *inode = dentry->d_inode;
might_sleep();
fsnotify_close(file);
/*
* The function eventpoll_release() should be the first called
* in the file cleanup chain.
......
......@@ -21,6 +21,7 @@
#include <linux/pagemap.h>
#include <linux/cdev.h>
#include <linux/bootmem.h>
#include <linux/inotify.h>
/*
* This is needed for the following functions:
......@@ -202,6 +203,10 @@ void inode_init_once(struct inode *inode)
INIT_LIST_HEAD(&inode->i_data.i_mmap_nonlinear);
spin_lock_init(&inode->i_lock);
i_size_ordered_init(inode);
#ifdef CONFIG_INOTIFY
INIT_LIST_HEAD(&inode->inotify_watches);
sema_init(&inode->inotify_sem, 1);
#endif
}
EXPORT_SYMBOL(inode_init_once);
......@@ -351,6 +356,7 @@ int invalidate_inodes(struct super_block * sb)
down(&iprune_sem);
spin_lock(&inode_lock);
inotify_unmount_inodes(&sb->s_inodes);
busy = invalidate_list(&sb->s_inodes, &throw_away);
spin_unlock(&inode_lock);
......
This diff is collapsed.
......@@ -21,7 +21,7 @@
#include <linux/namei.h>
#include <linux/quotaops.h>
#include <linux/pagemap.h>
#include <linux/dnotify.h>
#include <linux/fsnotify.h>
#include <linux/smp_lock.h>
#include <linux/personality.h>
#include <linux/security.h>
......@@ -1312,7 +1312,7 @@ int vfs_create(struct inode *dir, struct dentry *dentry, int mode,
DQUOT_INIT(dir);
error = dir->i_op->create(dir, dentry, mode, nd);
if (!error) {
inode_dir_notify(dir, DN_CREATE);
fsnotify_create(dir, dentry->d_name.name);
security_inode_post_create(dir, dentry, mode);
}
return error;
......@@ -1637,7 +1637,7 @@ int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
DQUOT_INIT(dir);
error = dir->i_op->mknod(dir, dentry, mode, dev);
if (!error) {
inode_dir_notify(dir, DN_CREATE);
fsnotify_create(dir, dentry->d_name.name);
security_inode_post_mknod(dir, dentry, mode, dev);
}
return error;
......@@ -1710,7 +1710,7 @@ int vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
DQUOT_INIT(dir);
error = dir->i_op->mkdir(dir, dentry, mode);
if (!error) {
inode_dir_notify(dir, DN_CREATE);
fsnotify_mkdir(dir, dentry->d_name.name);
security_inode_post_mkdir(dir,dentry, mode);
}
return error;
......@@ -1801,7 +1801,7 @@ int vfs_rmdir(struct inode *dir, struct dentry *dentry)
}
up(&dentry->d_inode->i_sem);
if (!error) {
inode_dir_notify(dir, DN_DELETE);
fsnotify_rmdir(dentry, dentry->d_inode, dir);
d_delete(dentry);
}
dput(dentry);
......@@ -1874,9 +1874,10 @@ int vfs_unlink(struct inode *dir, struct dentry *dentry)
/* We don't d_delete() NFS sillyrenamed files--they still exist. */
if (!error && !(dentry->d_flags & DCACHE_NFSFS_RENAMED)) {
fsnotify_unlink(dentry, dir);
d_delete(dentry);
inode_dir_notify(dir, DN_DELETE);
}
return error;
}
......@@ -1950,7 +1951,7 @@ int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname, i
DQUOT_INIT(dir);
error = dir->i_op->symlink(dir, dentry, oldname);
if (!error) {
inode_dir_notify(dir, DN_CREATE);
fsnotify_create(dir, dentry->d_name.name);
security_inode_post_symlink(dir, dentry, oldname);
}
return error;
......@@ -2023,7 +2024,7 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de
error = dir->i_op->link(old_dentry, dir, new_dentry);
up(&old_dentry->d_inode->i_sem);
if (!error) {
inode_dir_notify(dir, DN_CREATE);
fsnotify_create(dir, new_dentry->d_name.name);
security_inode_post_link(old_dentry, dir, new_dentry);
}
return error;
......@@ -2187,6 +2188,7 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
{
int error;
int is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
const char *old_name;
if (old_dentry->d_inode == new_dentry->d_inode)
return 0;
......@@ -2208,18 +2210,18 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
DQUOT_INIT(old_dir);
DQUOT_INIT(new_dir);
old_name = fsnotify_oldname_init(old_dentry->d_name.name);
if (is_dir)
error = vfs_rename_dir(old_dir,old_dentry,new_dir,new_dentry);
else
error = vfs_rename_other(old_dir,old_dentry,new_dir,new_dentry);
if (!error) {
if (old_dir == new_dir)
inode_dir_notify(old_dir, DN_RENAME);
else {
inode_dir_notify(old_dir, DN_DELETE);
inode_dir_notify(new_dir, DN_CREATE);
}
const char *new_name = old_dentry->d_name.name;
fsnotify_move(old_dir, new_dir, old_name, new_name, is_dir);
}
fsnotify_oldname_free(old_name);
return error;
}
......
......@@ -45,7 +45,7 @@
#endif /* CONFIG_NFSD_V3 */
#include <linux/nfsd/nfsfh.h>
#include <linux/quotaops.h>
#include <linux/dnotify.h>
#include <linux/fsnotify.h>
#include <linux/posix_acl.h>
#include <linux/posix_acl_xattr.h>
#ifdef CONFIG_NFSD_V4
......@@ -860,7 +860,7 @@ nfsd_vfs_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
nfsdstats.io_read += err;
*count = err;
err = 0;
dnotify_parent(file->f_dentry, DN_ACCESS);
fsnotify_access(file->f_dentry);
} else
err = nfserrno(err);
out:
......@@ -916,7 +916,7 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
set_fs(oldfs);
if (err >= 0) {
nfsdstats.io_write += cnt;
dnotify_parent(file->f_dentry, DN_MODIFY);
fsnotify_modify(file->f_dentry);
}
/* clear setuid/setgid flag after write */
......
......@@ -10,7 +10,7 @@
#include <linux/file.h>
#include <linux/smp_lock.h>
#include <linux/quotaops.h>
#include <linux/dnotify.h>
#include <linux/fsnotify.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/tty.h>
......@@ -951,6 +951,7 @@ asmlinkage long sys_open(const char __user * filename, int flags, int mode)
put_unused_fd(fd);
fd = PTR_ERR(f);
} else {
fsnotify_open(f->f_dentry);
fd_install(fd, f);
}
}
......
......@@ -10,7 +10,7 @@
#include <linux/file.h>
#include <linux/uio.h>
#include <linux/smp_lock.h>
#include <linux/dnotify.h>
#include <linux/fsnotify.h>
#include <linux/security.h>
#include <linux/module.h>
#include <linux/syscalls.h>
......@@ -252,7 +252,7 @@ ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
else
ret = do_sync_read(file, buf, count, pos);
if (ret > 0) {
dnotify_parent(file->f_dentry, DN_ACCESS);
fsnotify_access(file->f_dentry);
current->rchar += ret;
}
current->syscr++;
......@@ -303,7 +303,7 @@ ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_
else
ret = do_sync_write(file, buf, count, pos);
if (ret > 0) {
dnotify_parent(file->f_dentry, DN_MODIFY);
fsnotify_modify(file->f_dentry);
current->wchar += ret;
}
current->syscw++;
......@@ -539,9 +539,12 @@ static ssize_t do_readv_writev(int type, struct file *file,
out:
if (iov != iovstack)
kfree(iov);
if ((ret + (type == READ)) > 0)
dnotify_parent(file->f_dentry,
(type == READ) ? DN_ACCESS : DN_MODIFY);
if ((ret + (type == READ)) > 0) {
if (type == READ)
fsnotify_access(file->f_dentry);
else
fsnotify_modify(file->f_dentry);
}
return ret;
Efault:
ret = -EFAULT;
......
......@@ -3,7 +3,7 @@
*/
#include <linux/module.h>
#include <linux/dnotify.h>
#include <linux/fsnotify.h>
#include <linux/kobject.h>
#include <linux/namei.h>
#include <asm/uaccess.h>
......@@ -391,9 +391,6 @@ int sysfs_create_file(struct kobject * kobj, const struct attribute * attr)
* sysfs_update_file - update the modified timestamp on an object attribute.
* @kobj: object we're acting for.
* @attr: attribute descriptor.
*
* Also call dnotify for the dentry, which lots of userspace programs
* use.
*/
int sysfs_update_file(struct kobject * kobj, const struct attribute * attr)
{
......@@ -408,7 +405,7 @@ int sysfs_update_file(struct kobject * kobj, const struct attribute * attr)
if (victim->d_inode &&
(victim->d_parent->d_inode == dir->d_inode)) {
victim->d_inode->i_mtime = CURRENT_TIME;
dnotify_parent(victim, DN_MODIFY);
fsnotify_modify(victim);
/**
* Drop reference from initial sysfs_get_dentry().
......
......@@ -16,6 +16,7 @@
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/module.h>
#include <linux/fsnotify.h>
#include <asm/uaccess.h>
/*
......@@ -57,8 +58,10 @@ setxattr(struct dentry *d, char __user *name, void __user *value,
if (error)
goto out;
error = d->d_inode->i_op->setxattr(d, kname, kvalue, size, flags);
if (!error)
if (!error) {
fsnotify_xattr(d);
security_inode_post_setxattr(d, kname, kvalue, size, flags);
}
out:
up(&d->d_inode->i_sem);
}
......
......@@ -296,8 +296,11 @@
#define __NR_keyctl 288
#define __NR_ioprio_set 289
#define __NR_ioprio_get 290
#define __NR_inotify_init 291
#define __NR_inotify_add_watch 292
#define __NR_inotify_rm_watch 293
#define NR_syscalls 291
#define NR_syscalls 294
/*
* user-visible error numbers are in the range -1 - -128: see
......
......@@ -474,6 +474,11 @@ struct inode {
struct dnotify_struct *i_dnotify; /* for directory notifications */
#endif
#ifdef CONFIG_INOTIFY
struct list_head inotify_watches; /* watches on this inode */
struct semaphore inotify_sem; /* protects the watches list */
#endif
unsigned long i_state;
unsigned long dirtied_when; /* jiffies of first dirtying */
......@@ -1393,7 +1398,6 @@ extern void emergency_remount(void);
extern int do_remount_sb(struct super_block *sb, int flags,
void *data, int force);
extern sector_t bmap(struct inode *, sector_t);
extern int setattr_mask(unsigned int);
extern int notify_change(struct dentry *, struct iattr *);
extern int permission(struct inode *, int, struct nameidata *);
extern int generic_permission(struct inode *, int,
......
#ifndef _LINUX_FS_NOTIFY_H
#define _LINUX_FS_NOTIFY_H
/*
* include/linux/fsnotify.h - generic hooks for filesystem notification, to
* reduce in-source duplication from both dnotify and inotify.
*
* We don't compile any of this away in some complicated menagerie of ifdefs.
* Instead, we rely on the code inside to optimize away as needed.
*
* (C) Copyright 2005 Robert Love
*/
#ifdef __KERNEL__
#include <linux/dnotify.h>
#include <linux/inotify.h>
/*
* fsnotify_move - file old_name at old_dir was moved to new_name at new_dir
*/
static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
const char *old_name, const char *new_name,
int isdir)
{
u32 cookie = inotify_get_cookie();
if (old_dir == new_dir)
inode_dir_notify(old_dir, DN_RENAME);
else {
inode_dir_notify(old_dir, DN_DELETE);
inode_dir_notify(new_dir, DN_CREATE);
}
if (isdir)
isdir = IN_ISDIR;
inotify_inode_queue_event(old_dir, IN_MOVED_FROM|isdir,cookie,old_name);
inotify_inode_queue_event(new_dir, IN_MOVED_TO|isdir, cookie, new_name);
}
/*
* fsnotify_unlink - file was unlinked
*/
static inline void fsnotify_unlink(struct dentry *dentry, struct inode *dir)
{
struct inode *inode = dentry->d_inode;
inode_dir_notify(dir, DN_DELETE);
inotify_inode_queue_event(dir, IN_DELETE, 0, dentry->d_name.name);
inotify_inode_queue_event(inode, IN_DELETE_SELF, 0, NULL);
inotify_inode_is_dead(inode);
}
/*
* fsnotify_rmdir - directory was removed
*/
static inline void fsnotify_rmdir(struct dentry *dentry, struct inode *inode,
struct inode *dir)
{
inode_dir_notify(dir, DN_DELETE);
inotify_inode_queue_event(dir,IN_DELETE|IN_ISDIR,0,dentry->d_name.name);
inotify_inode_queue_event(inode, IN_DELETE_SELF | IN_ISDIR, 0, NULL);
inotify_inode_is_dead(inode);
}
/*
* fsnotify_create - 'name' was linked in
*/
static inline void fsnotify_create(struct inode *inode, const char *name)
{
inode_dir_notify(inode, DN_CREATE);
inotify_inode_queue_event(inode, IN_CREATE, 0, name);
}
/*
* fsnotify_mkdir - directory 'name' was created
*/
static inline void fsnotify_mkdir(struct inode *inode, const char *name)
{
inode_dir_notify(inode, DN_CREATE);
inotify_inode_queue_event(inode, IN_CREATE | IN_ISDIR, 0, name);
}
/*
* fsnotify_access - file was read
*/
static inline void fsnotify_access(struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
u32 mask = IN_ACCESS;
if (S_ISDIR(inode->i_mode))
mask |= IN_ISDIR;
dnotify_parent(dentry, DN_ACCESS);
inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
inotify_inode_queue_event(inode, mask, 0, NULL);
}
/*
* fsnotify_modify - file was modified
*/
static inline void fsnotify_modify(struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
u32 mask = IN_MODIFY;
if (S_ISDIR(inode->i_mode))
mask |= IN_ISDIR;
dnotify_parent(dentry, DN_MODIFY);
inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
inotify_inode_queue_event(inode, mask, 0, NULL);
}
/*
* fsnotify_open - file was opened
*/
static inline void fsnotify_open(struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
u32 mask = IN_OPEN;
if (S_ISDIR(inode->i_mode))
mask |= IN_ISDIR;
inotify_inode_queue_event(inode, mask, 0, NULL);
inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
}
/*
* fsnotify_close - file was closed
*/
static inline void fsnotify_close(struct file *file)
{
struct dentry *dentry = file->f_dentry;
struct inode *inode = dentry->d_inode;
const char *name = dentry->d_name.name;
mode_t mode = file->f_mode;
u32 mask = (mode & FMODE_WRITE) ? IN_CLOSE_WRITE : IN_CLOSE_NOWRITE;
if (S_ISDIR(inode->i_mode))
mask |= IN_ISDIR;
inotify_dentry_parent_queue_event(dentry, mask, 0, name);
inotify_inode_queue_event(inode, mask, 0, NULL);
}
/*
* fsnotify_xattr - extended attributes were changed
*/
static inline void fsnotify_xattr(struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
u32 mask = IN_ATTRIB;
if (S_ISDIR(inode->i_mode))
mask |= IN_ISDIR;
inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
inotify_inode_queue_event(inode, mask, 0, NULL);
}
/*
* fsnotify_change - notify_change event. file was modified and/or metadata
* was changed.
*/
static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid)
{
struct inode *inode = dentry->d_inode;
int dn_mask = 0;
u32 in_mask = 0;
if (ia_valid & ATTR_UID) {
in_mask |= IN_ATTRIB;
dn_mask |= DN_ATTRIB;
}
if (ia_valid & ATTR_GID) {
in_mask |= IN_ATTRIB;
dn_mask |= DN_ATTRIB;
}
if (ia_valid & ATTR_SIZE) {
in_mask |= IN_MODIFY;
dn_mask |= DN_MODIFY;
}
/* both times implies a utime(s) call */
if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME))
{
in_mask |= IN_ATTRIB;
dn_mask |= DN_ATTRIB;
} else if (ia_valid & ATTR_ATIME) {
in_mask |= IN_ACCESS;
dn_mask |= DN_ACCESS;
} else if (ia_valid & ATTR_MTIME) {
in_mask |= IN_MODIFY;
dn_mask |= DN_MODIFY;
}
if (ia_valid & ATTR_MODE) {
in_mask |= IN_ATTRIB;
dn_mask |= DN_ATTRIB;
}
if (dn_mask)
dnotify_parent(dentry, dn_mask);
if (in_mask) {
if (S_ISDIR(inode->i_mode))
in_mask |= IN_ISDIR;
inotify_inode_queue_event(inode, in_mask, 0, NULL);
inotify_dentry_parent_queue_event(dentry, in_mask, 0,
dentry->d_name.name);
}
}
#ifdef CONFIG_INOTIFY /* inotify helpers */
/*
* fsnotify_oldname_init - save off the old filename before we change it
*/
static inline const char *fsnotify_oldname_init(const char *name)
{
return kstrdup(name, GFP_KERNEL);
}
/*
* fsnotify_oldname_free - free the name we got from fsnotify_oldname_init
*/
static inline void fsnotify_oldname_free(const char *old_name)
{
kfree(old_name);
}
#else /* CONFIG_INOTIFY */
static inline const char *fsnotify_oldname_init(const char *name)
{
return NULL;
}
static inline void fsnotify_oldname_free(const char *old_name)
{
}
#endif /* ! CONFIG_INOTIFY */
#endif /* __KERNEL__ */
#endif /* _LINUX_FS_NOTIFY_H */
/*
* Inode based directory notification for Linux
*
* Copyright (C) 2005 John McCutchan
*/
#ifndef _LINUX_INOTIFY_H
#define _LINUX_INOTIFY_H
#include <linux/types.h>
/*
* struct inotify_event - structure read from the inotify device for each event
*
* When you are watching a directory, you will receive the filename for events
* such as IN_CREATE, IN_DELETE, IN_OPEN, IN_CLOSE, ..., relative to the wd.
*/
struct inotify_event {
__s32 wd; /* watch descriptor */
__u32 mask; /* watch mask */
__u32 cookie; /* cookie to synchronize two events */
__u32 len; /* length (including nulls) of name */
char name[0]; /* stub for possible name */
};
/* the following are legal, implemented events that user-space can watch for */
#define IN_ACCESS 0x00000001 /* File was accessed */
#define IN_MODIFY 0x00000002 /* File was modified */
#define IN_ATTRIB 0x00000004 /* Metadata changed */
#define IN_CLOSE_WRITE 0x00000008 /* Writtable file was closed */
#define IN_CLOSE_NOWRITE 0x00000010 /* Unwrittable file closed */
#define IN_OPEN 0x00000020 /* File was opened */
#define IN_MOVED_FROM 0x00000040 /* File was moved from X */
#define IN_MOVED_TO 0x00000080 /* File was moved to Y */
#define IN_CREATE 0x00000100 /* Subfile was created */
#define IN_DELETE 0x00000200 /* Subfile was deleted */
#define IN_DELETE_SELF 0x00000400 /* Self was deleted */
/* the following are legal events. they are sent as needed to any watch */
#define IN_UNMOUNT 0x00002000 /* Backing fs was unmounted */
#define IN_Q_OVERFLOW 0x00004000 /* Event queued overflowed */
#define IN_IGNORED 0x00008000 /* File was ignored */
/* helper events */
#define IN_CLOSE (IN_CLOSE_WRITE | IN_CLOSE_NOWRITE) /* close */
#define IN_MOVE (IN_MOVED_FROM | IN_MOVED_TO) /* moves */
/* special flags */
#define IN_ISDIR 0x40000000 /* event occurred against dir */
#define IN_ONESHOT 0x80000000 /* only send event once */
/*
* All of the events - we build the list by hand so that we can add flags in
* the future and not break backward compatibility. Apps will get only the
* events that they originally wanted. Be sure to add new events here!
*/
#define IN_ALL_EVENTS (IN_ACCESS | IN_MODIFY | IN_ATTRIB | IN_CLOSE_WRITE | \
IN_CLOSE_NOWRITE | IN_OPEN | IN_MOVED_FROM | \
IN_MOVED_TO | IN_DELETE | IN_CREATE | IN_DELETE_SELF)
#ifdef __KERNEL__
#include <linux/dcache.h>
#include <linux/fs.h>
#include <linux/config.h>
#ifdef CONFIG_INOTIFY
extern void inotify_inode_queue_event(struct inode *, __u32, __u32,
const char *);
extern void inotify_dentry_parent_queue_event(struct dentry *, __u32, __u32,
const char *);
extern void inotify_unmount_inodes(struct list_head *);
extern void inotify_inode_is_dead(struct inode *);
extern u32 inotify_get_cookie(void);
#else
static inline void inotify_inode_queue_event(struct inode *inode,
__u32 mask, __u32 cookie,
const char *filename)
{
}
static inline void inotify_dentry_parent_queue_event(struct dentry *dentry,
__u32 mask, __u32 cookie,
const char *filename)
{
}
static inline void inotify_unmount_inodes(struct list_head *list)
{
}
static inline void inotify_inode_is_dead(struct inode *inode)
{
}
static inline u32 inotify_get_cookie(void)
{
return 0;
}
#endif /* CONFIG_INOTIFY */
#endif /* __KERNEL __ */
#endif /* _LINUX_INOTIFY_H */
......@@ -410,6 +410,10 @@ struct user_struct {
atomic_t processes; /* How many processes does this user have? */
atomic_t files; /* How many open files does this user have? */
atomic_t sigpending; /* How many pending signals does this user have? */
#ifdef CONFIG_INOTIFY
atomic_t inotify_watches; /* How many inotify watches does this user have? */
atomic_t inotify_devs; /* How many inotify devs does this user have opened? */
#endif
/* protected by mq_lock */
unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
unsigned long locked_shm; /* How many pages of mlocked shm ? */
......
......@@ -61,7 +61,8 @@ enum
CTL_DEV=7, /* Devices */
CTL_BUS=8, /* Busses */
CTL_ABI=9, /* Binary emulation */
CTL_CPU=10 /* CPU stuff (speed scaling, etc) */
CTL_CPU=10, /* CPU stuff (speed scaling, etc) */
CTL_INOTIFY=11 /* Inotify */
};
/* CTL_BUS names: */
......@@ -70,6 +71,14 @@ enum
CTL_BUS_ISA=1 /* ISA */
};
/* CTL_INOTIFY names: */
enum
{
INOTIFY_MAX_USER_DEVICES=1, /* max number of inotify device instances per user */
INOTIFY_MAX_USER_WATCHES=2, /* max number of inotify watches per user */
INOTIFY_MAX_QUEUED_EVENTS=3 /* Max number of queued events per inotify device instance */
};
/* CTL_KERN names: */
enum
{
......
......@@ -80,6 +80,9 @@ cond_syscall(sys_keyctl);
cond_syscall(compat_sys_keyctl);
cond_syscall(compat_sys_socketcall);
cond_syscall(sys_set_zone_reclaim);
cond_syscall(sys_inotify_init);
cond_syscall(sys_inotify_add_watch);
cond_syscall(sys_inotify_rm_watch);
/* arch-specific weak syscall entries */
cond_syscall(sys_pciconfig_read);
......
......@@ -67,6 +67,12 @@ extern int printk_ratelimit_jiffies;
extern int printk_ratelimit_burst;
extern int pid_max_min, pid_max_max;
#ifdef CONFIG_INOTIFY
extern int inotify_max_user_devices;
extern int inotify_max_user_watches;
extern int inotify_max_queued_events;
#endif
#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
int unknown_nmi_panic;
extern int proc_unknown_nmi_panic(ctl_table *, int, struct file *,
......@@ -218,6 +224,7 @@ static ctl_table root_table[] = {
.mode = 0555,
.child = dev_table,
},
{ .ctl_name = 0 }
};
......@@ -959,6 +966,40 @@ static ctl_table fs_table[] = {
.mode = 0644,
.proc_handler = &proc_dointvec,
},
#ifdef CONFIG_INOTIFY
{
.ctl_name = INOTIFY_MAX_USER_DEVICES,
.procname = "max_user_devices",
.data = &inotify_max_user_devices,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec_minmax,
.strategy = &sysctl_intvec,
.extra1 = &zero,
},
{
.ctl_name = INOTIFY_MAX_USER_WATCHES,
.procname = "max_user_watches",
.data = &inotify_max_user_watches,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec_minmax,
.strategy = &sysctl_intvec,
.extra1 = &zero,
},
{
.ctl_name = INOTIFY_MAX_QUEUED_EVENTS,
.procname = "max_queued_events",
.data = &inotify_max_queued_events,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec_minmax,
.strategy = &sysctl_intvec,
.extra1 = &zero
},
#endif
{ .ctl_name = 0 }
};
......@@ -968,7 +1009,7 @@ static ctl_table debug_table[] = {
static ctl_table dev_table[] = {
{ .ctl_name = 0 }
};
};
extern void init_irq_proc (void);
......
......@@ -120,6 +120,10 @@ struct user_struct * alloc_uid(uid_t uid)
atomic_set(&new->processes, 0);
atomic_set(&new->files, 0);
atomic_set(&new->sigpending, 0);
#ifdef CONFIG_INOTIFY
atomic_set(&new->inotify_watches, 0);
atomic_set(&new->inotify_devs, 0);
#endif
new->mq_bytes = 0;
new->locked_shm = 0;
......
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