aboutsummaryrefslogtreecommitdiff
path: root/fs
diff options
context:
space:
mode:
authorThomas Gleixner <tglx@tglx.tec.linutronix.de>2005-07-13 10:45:00 +0200
committerThomas Gleixner <tglx@mtd.linutronix.de>2005-07-13 10:45:00 +0200
commit1b3035b7fcc72b6b36f2a3634dad832eb2453ce8 (patch)
tree728174d72943cc9b981a5843553551df62eddc41 /fs
parenta98a5d04f400ad112e59cadd739dbabf89417e60 (diff)
parentc32511e2718618f0b53479eb36e07439aa363a74 (diff)
Merge with rsync://fileserver/linux
Diffstat (limited to 'fs')
-rw-r--r--fs/Kconfig13
-rw-r--r--fs/Makefile1
-rw-r--r--fs/attr.c33
-rw-r--r--fs/char_dev.c3
-rw-r--r--fs/compat.c12
-rw-r--r--fs/exec.c12
-rw-r--r--fs/ext2/ext2.h9
-rw-r--r--fs/ext2/super.c24
-rw-r--r--fs/ext3/super.c70
-rw-r--r--fs/file_table.c3
-rw-r--r--fs/inode.c43
-rw-r--r--fs/inotify.c999
-rw-r--r--fs/namei.c30
-rw-r--r--fs/nfsd/vfs.c6
-rw-r--r--fs/open.c3
-rw-r--r--fs/read_write.c15
-rw-r--r--fs/reiserfs/bitmap.c1842
-rw-r--r--fs/reiserfs/dir.c488
-rw-r--r--fs/reiserfs/do_balan.c3236
-rw-r--r--fs/reiserfs/file.c2564
-rw-r--r--fs/reiserfs/fix_node.c4051
-rw-r--r--fs/reiserfs/hashes.c193
-rw-r--r--fs/reiserfs/ibalance.c1844
-rw-r--r--fs/reiserfs/inode.c4915
-rw-r--r--fs/reiserfs/ioctl.c197
-rw-r--r--fs/reiserfs/item_ops.c979
-rw-r--r--fs/reiserfs/journal.c6855
-rw-r--r--fs/reiserfs/lbalance.c2218
-rw-r--r--fs/reiserfs/namei.c2574
-rw-r--r--fs/reiserfs/objectid.c303
-rw-r--r--fs/reiserfs/prints.c1003
-rw-r--r--fs/reiserfs/procfs.c695
-rw-r--r--fs/reiserfs/resize.c207
-rw-r--r--fs/reiserfs/stree.c3369
-rw-r--r--fs/reiserfs/super.c3623
-rw-r--r--fs/reiserfs/tail_conversion.c463
-rw-r--r--fs/reiserfs/xattr.c2173
-rw-r--r--fs/reiserfs/xattr_acl.c641
-rw-r--r--fs/reiserfs/xattr_security.c54
-rw-r--r--fs/reiserfs/xattr_trusted.c70
-rw-r--r--fs/reiserfs/xattr_user.c89
-rw-r--r--fs/sysfs/file.c7
-rw-r--r--fs/xattr.c5
43 files changed, 24413 insertions, 21521 deletions
diff --git a/fs/Kconfig b/fs/Kconfig
index f93fd41b025..5d0c4be43db 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -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
diff --git a/fs/Makefile b/fs/Makefile
index 20edcf28bfd..cf95eb894fd 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -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
diff --git a/fs/attr.c b/fs/attr.c
index c3c76fe7834..b1796fb9e52 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -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;
}
diff --git a/fs/char_dev.c b/fs/char_dev.c
index a69a5d8a406..3b1b1eefdbb 100644
--- a/fs/char_dev.c
+++ b/fs/char_dev.c
@@ -277,8 +277,9 @@ static struct kobject *cdev_get(struct cdev *p)
void cdev_put(struct cdev *p)
{
if (p) {
+ struct module *owner = p->owner;
kobject_put(&p->kobj);
- module_put(p->owner);
+ module_put(owner);
}
}
diff --git a/fs/compat.c b/fs/compat.c
index 728cd836538..6b06b6bae35 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -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;
}
diff --git a/fs/exec.c b/fs/exec.c
index 48871917d36..222ab1c572d 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -642,6 +642,18 @@ static inline int de_thread(struct task_struct *tsk)
count = 2;
if (thread_group_leader(current))
count = 1;
+ else {
+ /*
+ * The SIGALRM timer survives the exec, but needs to point
+ * at us as the new group leader now. We have a race with
+ * a timer firing now getting the old leader, so we need to
+ * synchronize with any firing (by calling del_timer_sync)
+ * before we can safely let the old group leader die.
+ */
+ sig->real_timer.data = (unsigned long)current;
+ if (del_timer_sync(&sig->real_timer))
+ add_timer(&sig->real_timer);
+ }
while (atomic_read(&sig->count) > count) {
sig->group_exit_task = current;
sig->notify_count = count;
diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h
index eed521d22cf..e977f8566d1 100644
--- a/fs/ext2/ext2.h
+++ b/fs/ext2/ext2.h
@@ -2,6 +2,15 @@
#include <linux/ext2_fs.h>
/*
+ * ext2 mount options
+ */
+struct ext2_mount_options {
+ unsigned long s_mount_opt;
+ uid_t s_resuid;
+ gid_t s_resgid;
+};
+
+/*
* second extended file system inode data in memory
*/
struct ext2_inode_info {
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index 876e391f287..dcfe331dc4c 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -936,12 +936,23 @@ static int ext2_remount (struct super_block * sb, int * flags, char * data)
struct ext2_sb_info * sbi = EXT2_SB(sb);
struct ext2_super_block * es;
unsigned long old_mount_opt = sbi->s_mount_opt;
+ struct ext2_mount_options old_opts;
+ unsigned long old_sb_flags;
+ int err;
+
+ /* Store the old options */
+ old_sb_flags = sb->s_flags;
+ old_opts.s_mount_opt = sbi->s_mount_opt;
+ old_opts.s_resuid = sbi->s_resuid;
+ old_opts.s_resgid = sbi->s_resgid;
/*
* Allow the "check" option to be passed as a remount option.
*/
- if (!parse_options (data, sbi))
- return -EINVAL;
+ if (!parse_options (data, sbi)) {
+ err = -EINVAL;
+ goto restore_opts;
+ }
sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
@@ -971,7 +982,8 @@ static int ext2_remount (struct super_block * sb, int * flags, char * data)
printk("EXT2-fs: %s: couldn't remount RDWR because of "
"unsupported optional features (%x).\n",
sb->s_id, le32_to_cpu(ret));
- return -EROFS;
+ err = -EROFS;
+ goto restore_opts;
}
/*
* Mounting a RDONLY partition read-write, so reread and
@@ -984,6 +996,12 @@ static int ext2_remount (struct super_block * sb, int * flags, char * data)
}
ext2_sync_super(sb, es);
return 0;
+restore_opts:
+ sbi->s_mount_opt = old_opts.s_mount_opt;
+ sbi->s_resuid = old_opts.s_resuid;
+ sbi->s_resgid = old_opts.s_resgid;
+ sb->s_flags = old_sb_flags;
+ return err;
}
static int ext2_statfs (struct super_block * sb, struct kstatfs * buf)
diff --git a/fs/ext3/super.c b/fs/ext3/super.c
index a6d1779d7de..3c3c6e399fb 100644
--- a/fs/ext3/super.c
+++ b/fs/ext3/super.c
@@ -890,7 +890,10 @@ clear_qf_name:
"quota turned on.\n");
return 0;
}
- kfree(sbi->s_qf_names[qtype]);
+ /*
+ * The space will be released later when all options
+ * are confirmed to be correct
+ */
sbi->s_qf_names[qtype] = NULL;
break;
case Opt_jqfmt_vfsold:
@@ -939,7 +942,7 @@ clear_qf_name:
case Opt_ignore:
break;
case Opt_resize:
- if (!n_blocks_count) {
+ if (!is_remount) {
printk("EXT3-fs: resize option only available "
"for remount\n");
return 0;
@@ -2109,14 +2112,33 @@ static int ext3_remount (struct super_block * sb, int * flags, char * data)
{
struct ext3_super_block * es;
struct ext3_sb_info *sbi = EXT3_SB(sb);
- unsigned long tmp;
unsigned long n_blocks_count = 0;
+ unsigned long old_sb_flags;
+ struct ext3_mount_options old_opts;
+ int err;
+#ifdef CONFIG_QUOTA
+ int i;
+#endif
+
+ /* Store the original options */
+ old_sb_flags = sb->s_flags;
+ old_opts.s_mount_opt = sbi->s_mount_opt;
+ old_opts.s_resuid = sbi->s_resuid;
+ old_opts.s_resgid = sbi->s_resgid;
+ old_opts.s_commit_interval = sbi->s_commit_interval;
+#ifdef CONFIG_QUOTA
+ old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
+ for (i = 0; i < MAXQUOTAS; i++)
+ old_opts.s_qf_names[i] = sbi->s_qf_names[i];
+#endif
/*
* Allow the "check" option to be passed as a remount option.
*/
- if (!parse_options(data, sb, &tmp, &n_blocks_count, 1))
- return -EINVAL;
+ if (!parse_options(data, sb, NULL, &n_blocks_count, 1)) {
+ err = -EINVAL;
+ goto restore_opts;
+ }
if (sbi->s_mount_opt & EXT3_MOUNT_ABORT)
ext3_abort(sb, __FUNCTION__, "Abort forced by user");
@@ -2130,8 +2152,10 @@ static int ext3_remount (struct super_block * sb, int * flags, char * data)
if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
n_blocks_count > le32_to_cpu(es->s_blocks_count)) {
- if (sbi->s_mount_opt & EXT3_MOUNT_ABORT)
- return -EROFS;
+ if (sbi->s_mount_opt & EXT3_MOUNT_ABORT) {
+ err = -EROFS;
+ goto restore_opts;
+ }
if (*flags & MS_RDONLY) {
/*
@@ -2158,7 +2182,8 @@ static int ext3_remount (struct super_block * sb, int * flags, char * data)
"remount RDWR because of unsupported "
"optional features (%x).\n",
sb->s_id, le32_to_cpu(ret));
- return -EROFS;
+ err = -EROFS;
+ goto restore_opts;
}
/*
* Mounting a RDONLY partition read-write, so reread
@@ -2168,13 +2193,38 @@ static int ext3_remount (struct super_block * sb, int * flags, char * data)
*/
ext3_clear_journal_err(sb, es);
sbi->s_mount_state = le16_to_cpu(es->s_state);
- if ((ret = ext3_group_extend(sb, es, n_blocks_count)))
- return ret;
+ if ((ret = ext3_group_extend(sb, es, n_blocks_count))) {
+ err = ret;
+ goto restore_opts;
+ }
if (!ext3_setup_super (sb, es, 0))
sb->s_flags &= ~MS_RDONLY;
}
}
+#ifdef CONFIG_QUOTA
+ /* Release old quota file names */
+ for (i = 0; i < MAXQUOTAS; i++)
+ if (old_opts.s_qf_names[i] &&
+ old_opts.s_qf_names[i] != sbi->s_qf_names[i])
+ kfree(old_opts.s_qf_names[i]);
+#endif
return 0;
+restore_opts:
+ sb->s_flags = old_sb_flags;
+ sbi->s_mount_opt = old_opts.s_mount_opt;
+ sbi->s_resuid = old_opts.s_resuid;
+ sbi->s_resgid = old_opts.s_resgid;
+ sbi->s_commit_interval = old_opts.s_commit_interval;
+#ifdef CONFIG_QUOTA
+ sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
+ for (i = 0; i < MAXQUOTAS; i++) {
+ if (sbi->s_qf_names[i] &&
+ old_opts.s_qf_names[i] != sbi->s_qf_names[i])
+ kfree(sbi->s_qf_names[i]);
+ sbi->s_qf_names[i] = old_opts.s_qf_names[i];
+ }
+#endif
+ return err;
}
static int ext3_statfs (struct super_block * sb, struct kstatfs * buf)
diff --git a/fs/file_table.c b/fs/file_table.c
index fa7849fae13..1d3de78e6bc 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -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.
diff --git a/fs/inode.c b/fs/inode.c
index 6d695037a0a..96364fae084 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -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);
@@ -282,6 +287,13 @@ static void dispose_list(struct list_head *head)
if (inode->i_data.nrpages)
truncate_inode_pages(&inode->i_data, 0);
clear_inode(inode);
+
+ spin_lock(&inode_lock);
+ hlist_del_init(&inode->i_hash);
+ list_del_init(&inode->i_sb_list);
+ spin_unlock(&inode_lock);
+
+ wake_up_inode(inode);
destroy_inode(inode);
nr_disposed++;
}
@@ -317,8 +329,6 @@ static int invalidate_list(struct list_head *head, struct list_head *dispose)
inode = list_entry(tmp, struct inode, i_sb_list);
invalidate_inode_buffers(inode);
if (!atomic_read(&inode->i_count)) {
- hlist_del_init(&inode->i_hash);
- list_del(&inode->i_sb_list);
list_move(&inode->i_list, dispose);
inode->i_state |= I_FREEING;
count++;
@@ -346,6 +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);
@@ -439,8 +450,6 @@ static void prune_icache(int nr_to_scan)
if (!can_unuse(inode))
continue;
}
- hlist_del_init(&inode->i_hash);
- list_del_init(&inode->i_sb_list);
list_move(&inode->i_list, &freeable);
inode->i_state |= I_FREEING;
nr_pruned++;
@@ -1244,29 +1253,21 @@ int inode_wait(void *word)
}
/*
- * If we try to find an inode in the inode hash while it is being deleted, we
- * have to wait until the filesystem completes its deletion before reporting
- * that it isn't found. This is because iget will immediately call
- * ->read_inode, and we want to be sure that evidence of the deletion is found
- * by ->read_inode.
+ * If we try to find an inode in the inode hash while it is being
+ * deleted, we have to wait until the filesystem completes its
+ * deletion before reporting that it isn't found. This function waits
+ * until the deletion _might_ have completed. Callers are responsible
+ * to recheck inode state.
+ *
+ * It doesn't matter if I_LOCK is not set initially, a call to
+ * wake_up_inode() after removing from the hash list will DTRT.
+ *
* This is called with inode_lock held.
*/
static void __wait_on_freeing_inode(struct inode *inode)
{
wait_queue_head_t *wq;
DEFINE_WAIT_BIT(wait, &inode->i_state, __I_LOCK);
-
- /*
- * I_FREEING and I_CLEAR are cleared in process context under
- * inode_lock, so we have to give the tasks who would clear them
- * a chance to run and acquire inode_lock.
- */
- if (!(inode->i_state & I_LOCK)) {
- spin_unlock(&inode_lock);
- yield();
- spin_lock(&inode_lock);
- return;
- }
wq = bit_waitqueue(&inode->i_state, __I_LOCK);
prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE);
spin_unlock(&inode_lock);
diff --git a/fs/inotify.c b/fs/inotify.c
new file mode 100644
index 00000000000..e423bfe0c86
--- /dev/null
+++ b/fs/inotify.c
@@ -0,0 +1,999 @@
+/*
+ * fs/inotify.c - inode-based file event notifications
+ *
+ * Authors:
+ * John McCutchan <ttb@tentacle.dhs.org>
+ * Robert Love <rml@novell.com>
+ *
+ * Copyright (C) 2005 John McCutchan
+ *
+ * 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/module.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/idr.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/poll.h>
+#include <linux/device.h>
+#include <linux/miscdevice.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/writeback.h>
+#include <linux/inotify.h>
+
+#include <asm/ioctls.h>
+
+static atomic_t inotify_cookie;
+
+static kmem_cache_t *watch_cachep;
+static kmem_cache_t *event_cachep;
+
+static struct vfsmount *inotify_mnt;
+
+/* These are configurable via /proc/sys/inotify */
+int inotify_max_user_devices;
+int inotify_max_user_watches;
+int inotify_max_queued_events;
+
+/*
+ * Lock ordering:
+ *
+ * dentry->d_lock (used to keep d_move() away from dentry->d_parent)
+ * iprune_sem (synchronize shrink_icache_memory())
+ * inode_lock (protects the super_block->s_inodes list)
+ * inode->inotify_sem (protects inode->inotify_watches and watches->i_list)
+ * inotify_dev->sem (protects inotify_device and watches->d_list)
+ */
+
+/*
+ * Lifetimes of the three main data structures--inotify_device, inode, and
+ * inotify_watch--are managed by reference count.
+ *
+ * inotify_device: Lifetime is from open until release. Additional references
+ * can bump the count via get_inotify_dev() and drop the count via
+ * put_inotify_dev().
+ *
+ * inotify_watch: Lifetime is from create_watch() to destory_watch().
+ * Additional references can bump the count via get_inotify_watch() and drop
+ * the count via put_inotify_watch().
+ *
+ * inode: Pinned so long as the inode is associated with a watch, from
+ * create_watch() to put_inotify_watch().
+ */
+
+/*
+ * struct inotify_device - represents an open instance of an inotify device
+ *
+ * This structure is protected by the semaphore 'sem'.
+ */
+struct inotify_device {
+ wait_queue_head_t wq; /* wait queue for i/o */
+ struct idr idr; /* idr mapping wd -> watch */
+ struct semaphore sem; /* protects this bad boy */
+ struct list_head events; /* list of queued events */
+ struct list_head watches; /* list of watches */
+ atomic_t count; /* reference count */
+ struct user_struct *user; /* user who opened this dev */
+ unsigned int queue_size; /* size of the queue (bytes) */
+ unsigned int event_count; /* number of pending events */
+ unsigned int max_events; /* maximum number of events */
+};
+
+/*
+ * struct inotify_kernel_event - An inotify event, originating from a watch and
+ * queued for user-space. A list of these is attached to each instance of the
+ * device. In read(), this list is walked and all events that can fit in the
+ * buffer are returned.
+ *
+ * Protected by dev->sem of the device in which we are queued.
+ */
+struct inotify_kernel_event {
+ struct inotify_event event; /* the user-space event */
+ struct list_head list; /* entry in inotify_device's list */
+ char *name; /* filename, if any */
+};
+
+/*
+ * struct inotify_watch - represents a watch request on a specific inode
+ *
+ * d_list is protected by dev->sem of the associated watch->dev.
+ * i_list and mask are protected by inode->inotify_sem of the associated inode.
+ * dev, inode, and wd are never written to once the watch is created.
+ */
+struct inotify_watch {
+ struct list_head d_list; /* entry in inotify_device's list */
+ struct list_head i_list; /* entry in inode's list */
+ atomic_t count; /* reference count */
+ struct inotify_device *dev; /* associated device */
+ struct inode *inode; /* associated inode */
+ s32 wd; /* watch descriptor */
+ u32 mask; /* event mask for this watch */
+};
+
+static inline void get_inotify_dev(struct inotify_device *dev)
+{
+ atomic_inc(&dev->count);
+}
+
+static inline void put_inotify_dev(struct inotify_device *dev)
+{
+ if (atomic_dec_and_test(&dev->count)) {
+ atomic_dec(&dev->user->inotify_devs);
+ free_uid(dev->user);
+ kfree(dev);
+ }
+}
+
+static inline void get_inotify_watch(struct inotify_watch *watch)
+{
+ atomic_inc(&watch->count);
+}
+
+/*
+ * put_inotify_watch - decrements the ref count on a given watch. cleans up
+ * the watch and its references if the count reaches zero.
+ */
+static inline void put_inotify_watch(struct inotify_watch *watch)
+{
+ if (atomic_dec_and_test(&watch->count)) {
+ put_inotify_dev(watch->dev);
+ iput(watch->inode);
+ kmem_cache_free(watch_cachep, watch);
+ }
+}
+
+/*
+ * kernel_event - create a new kernel event with the given parameters
+ *
+ * This function can sleep.
+ */
+static struct inotify_kernel_event * kernel_event(s32 wd, u32 mask, u32 cookie,
+ const char *name)
+{
+ struct inotify_kernel_event *kevent;
+
+ kevent = kmem_cache_alloc(event_cachep, GFP_KERNEL);
+ if (unlikely(!kevent))
+ return NULL;
+
+ /* we hand this out to user-space, so zero it just in case */
+ memset(&kevent->event, 0, sizeof(struct inotify_event));
+
+ kevent->event.wd = wd;
+ kevent->event.mask = mask;
+ kevent->event.cookie = cookie;
+
+ INIT_LIST_HEAD(&kevent->list);
+
+ if (name) {
+ size_t len, rem, event_size = sizeof(struct inotify_event);
+
+ /*
+ * We need to pad the filename so as to properly align an
+ * array of inotify_event structures. Because the structure is
+ * small and the common case is a small filename, we just round
+ * up to the next multiple of the structure's sizeof. This is
+ * simple and safe for all architectures.
+ */
+ len = strlen(name) + 1;
+ rem = event_size - len;
+ if (len > event_size) {
+ rem = event_size - (len % event_size);
+ if (len % event_size == 0)
+ rem = 0;
+ }
+
+ kevent->name = kmalloc(len + rem, GFP_KERNEL);
+ if (unlikely(!kevent->name)) {
+ kmem_cache_free(event_cachep, kevent);
+ return NULL;
+ }
+ memcpy(kevent->name, name, len);
+ if (rem)
+ memset(kevent->name + len, 0, rem);
+ kevent->event.len = len + rem;
+ } else {
+ kevent->event.len = 0;
+ kevent->name = NULL;
+ }
+
+ return kevent;
+}
+
+/*
+ * inotify_dev_get_event - return the next event in the given dev's queue
+ *
+ * Caller must hold dev->sem.
+ */
+static inline struct inotify_kernel_event *
+inotify_dev_get_event(struct inotify_device *dev)
+{
+ return list_entry(dev->events.next, struct inotify_kernel_event, list);
+}
+
+/*
+ * inotify_dev_queue_event - add a new event to the given device
+ *
+ * Caller must hold dev->sem. Can sleep (calls kernel_event()).
+ */
+static void inotify_dev_queue_event(struct inotify_device *dev,
+ struct inotify_watch *watch, u32 mask,
+ u32 cookie, const char *name)
+{
+ struct inotify_kernel_event *kevent, *last;
+
+ /* coalescing: drop this event if it is a dupe of the previous */
+ last = inotify_dev_get_event(dev);
+ if (last && last->event.mask == mask && last->event.wd == watch->wd &&
+ last->event.cookie == cookie) {
+ const char *lastname = last->name;
+
+ if (!name && !lastname)
+ return;
+ if (name && lastname && !strcmp(lastname, name))
+ return;
+ }
+
+ /* the queue overflowed and we already sent the Q_OVERFLOW event */
+ if (unlikely(dev->event_count > dev->max_events))
+ return;
+
+ /* if the queue overflows, we need to notify user space */
+ if (unlikely(dev->event_count == dev->max_events))
+ kevent = kernel_event(-1, IN_Q_OVERFLOW, cookie, NULL);
+ else
+ kevent = kernel_event(watch->wd, mask, cookie, name);
+
+ if (unlikely(!kevent))
+ return;
+