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Diffstat (limited to 'fs/notify/inotify/inotify_user.c')
-rw-r--r--fs/notify/inotify/inotify_user.c369
1 files changed, 234 insertions, 135 deletions
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index e46ca68..bf7f6d7 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -46,17 +46,11 @@
/* these are configurable via /proc/sys/fs/inotify/ */
static int inotify_max_user_instances __read_mostly;
static int inotify_max_queued_events __read_mostly;
-int inotify_max_user_watches __read_mostly;
+static int inotify_max_user_watches __read_mostly;
static struct kmem_cache *inotify_inode_mark_cachep __read_mostly;
struct kmem_cache *event_priv_cachep __read_mostly;
-/*
- * When inotify registers a new group it increments this and uses that
- * value as an offset to set the fsnotify group "name" and priority.
- */
-static atomic_t inotify_grp_num;
-
#ifdef CONFIG_SYSCTL
#include <linux/sysctl.h>
@@ -96,11 +90,14 @@ static inline __u32 inotify_arg_to_mask(u32 arg)
{
__u32 mask;
- /* everything should accept their own ignored and cares about children */
- mask = (FS_IN_IGNORED | FS_EVENT_ON_CHILD);
+ /*
+ * everything should accept their own ignored, cares about children,
+ * and should receive events when the inode is unmounted
+ */
+ mask = (FS_IN_IGNORED | FS_EVENT_ON_CHILD | FS_UNMOUNT);
/* mask off the flags used to open the fd */
- mask |= (arg & (IN_ALL_EVENTS | IN_ONESHOT));
+ mask |= (arg & (IN_ALL_EVENTS | IN_ONESHOT | IN_EXCL_UNLINK));
return mask;
}
@@ -144,6 +141,8 @@ static struct fsnotify_event *get_one_event(struct fsnotify_group *group,
event = fsnotify_peek_notify_event(group);
+ pr_debug("%s: group=%p event=%p\n", __func__, group, event);
+
if (event->name_len)
event_size += roundup(event->name_len + 1, event_size);
@@ -173,6 +172,8 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
size_t event_size = sizeof(struct inotify_event);
size_t name_len = 0;
+ pr_debug("%s: group=%p event=%p\n", __func__, group, event);
+
/* we get the inotify watch descriptor from the event private data */
spin_lock(&event->lock);
fsn_priv = fsnotify_remove_priv_from_event(group, event);
@@ -245,6 +246,8 @@ static ssize_t inotify_read(struct file *file, char __user *buf,
kevent = get_one_event(group, count);
mutex_unlock(&group->notification_mutex);
+ pr_debug("%s: group=%p kevent=%p\n", __func__, group, kevent);
+
if (kevent) {
ret = PTR_ERR(kevent);
if (IS_ERR(kevent))
@@ -289,6 +292,8 @@ static int inotify_release(struct inode *ignored, struct file *file)
struct fsnotify_group *group = file->private_data;
struct user_struct *user = group->inotify_data.user;
+ pr_debug("%s: group=%p\n", __func__, group);
+
fsnotify_clear_marks_by_group(group);
/* free this group, matching get was inotify_init->fsnotify_obtain_group */
@@ -312,6 +317,8 @@ static long inotify_ioctl(struct file *file, unsigned int cmd,
group = file->private_data;
p = (void __user *) arg;
+ pr_debug("%s: group=%p cmd=%u\n", __func__, group, cmd);
+
switch (cmd) {
case FIONREAD:
mutex_lock(&group->notification_mutex);
@@ -357,59 +364,159 @@ static int inotify_find_inode(const char __user *dirname, struct path *path, uns
return error;
}
+static int inotify_add_to_idr(struct idr *idr, spinlock_t *idr_lock,
+ int *last_wd,
+ struct inotify_inode_mark *i_mark)
+{
+ int ret;
+
+ do {
+ if (unlikely(!idr_pre_get(idr, GFP_KERNEL)))
+ return -ENOMEM;
+
+ spin_lock(idr_lock);
+ ret = idr_get_new_above(idr, i_mark, *last_wd + 1,
+ &i_mark->wd);
+ /* we added the mark to the idr, take a reference */
+ if (!ret) {
+ *last_wd = i_mark->wd;
+ fsnotify_get_mark(&i_mark->fsn_mark);
+ }
+ spin_unlock(idr_lock);
+ } while (ret == -EAGAIN);
+
+ return ret;
+}
+
+static struct inotify_inode_mark *inotify_idr_find_locked(struct fsnotify_group *group,
+ int wd)
+{
+ struct idr *idr = &group->inotify_data.idr;
+ spinlock_t *idr_lock = &group->inotify_data.idr_lock;
+ struct inotify_inode_mark *i_mark;
+
+ assert_spin_locked(idr_lock);
+
+ i_mark = idr_find(idr, wd);
+ if (i_mark) {
+ struct fsnotify_mark *fsn_mark = &i_mark->fsn_mark;
+
+ fsnotify_get_mark(fsn_mark);
+ /* One ref for being in the idr, one ref we just took */
+ BUG_ON(atomic_read(&fsn_mark->refcnt) < 2);
+ }
+
+ return i_mark;
+}
+
+static struct inotify_inode_mark *inotify_idr_find(struct fsnotify_group *group,
+ int wd)
+{
+ struct inotify_inode_mark *i_mark;
+ spinlock_t *idr_lock = &group->inotify_data.idr_lock;
+
+ spin_lock(idr_lock);
+ i_mark = inotify_idr_find_locked(group, wd);
+ spin_unlock(idr_lock);
+
+ return i_mark;
+}
+
+static void do_inotify_remove_from_idr(struct fsnotify_group *group,
+ struct inotify_inode_mark *i_mark)
+{
+ struct idr *idr = &group->inotify_data.idr;
+ spinlock_t *idr_lock = &group->inotify_data.idr_lock;
+ int wd = i_mark->wd;
+
+ assert_spin_locked(idr_lock);
+
+ idr_remove(idr, wd);
+
+ /* removed from the idr, drop that ref */
+ fsnotify_put_mark(&i_mark->fsn_mark);
+}
+
/*
* Remove the mark from the idr (if present) and drop the reference
* on the mark because it was in the idr.
*/
static void inotify_remove_from_idr(struct fsnotify_group *group,
- struct inotify_inode_mark_entry *ientry)
+ struct inotify_inode_mark *i_mark)
{
- struct idr *idr;
- struct fsnotify_mark_entry *entry;
- struct inotify_inode_mark_entry *found_ientry;
+ spinlock_t *idr_lock = &group->inotify_data.idr_lock;
+ struct inotify_inode_mark *found_i_mark = NULL;
int wd;
- spin_lock(&group->inotify_data.idr_lock);
- idr = &group->inotify_data.idr;
- wd = ientry->wd;
+ spin_lock(idr_lock);
+ wd = i_mark->wd;
- if (wd == -1)
+ /*
+ * does this i_mark think it is in the idr? we shouldn't get called
+ * if it wasn't....
+ */
+ if (wd == -1) {
+ WARN_ONCE(1, "%s: i_mark=%p i_mark->wd=%d i_mark->group=%p"
+ " i_mark->inode=%p\n", __func__, i_mark, i_mark->wd,
+ i_mark->fsn_mark.group, i_mark->fsn_mark.i.inode);
goto out;
+ }
- entry = idr_find(&group->inotify_data.idr, wd);
- if (unlikely(!entry))
+ /* Lets look in the idr to see if we find it */
+ found_i_mark = inotify_idr_find_locked(group, wd);
+ if (unlikely(!found_i_mark)) {
+ WARN_ONCE(1, "%s: i_mark=%p i_mark->wd=%d i_mark->group=%p"
+ " i_mark->inode=%p\n", __func__, i_mark, i_mark->wd,
+ i_mark->fsn_mark.group, i_mark->fsn_mark.i.inode);
goto out;
+ }
- found_ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry);
- if (unlikely(found_ientry != ientry)) {
- /* We found an entry in the idr with the right wd, but it's
- * not the entry we were told to remove. eparis seriously
- * fucked up somewhere. */
- WARN_ON(1);
- ientry->wd = -1;
+ /*
+ * We found an mark in the idr at the right wd, but it's
+ * not the mark we were told to remove. eparis seriously
+ * fucked up somewhere.
+ */
+ if (unlikely(found_i_mark != i_mark)) {
+ WARN_ONCE(1, "%s: i_mark=%p i_mark->wd=%d i_mark->group=%p "
+ "mark->inode=%p found_i_mark=%p found_i_mark->wd=%d "
+ "found_i_mark->group=%p found_i_mark->inode=%p\n",
+ __func__, i_mark, i_mark->wd, i_mark->fsn_mark.group,
+ i_mark->fsn_mark.i.inode, found_i_mark, found_i_mark->wd,
+ found_i_mark->fsn_mark.group,
+ found_i_mark->fsn_mark.i.inode);
goto out;
}
- /* One ref for being in the idr, one ref held by the caller */
- BUG_ON(atomic_read(&entry->refcnt) < 2);
-
- idr_remove(idr, wd);
- ientry->wd = -1;
+ /*
+ * One ref for being in the idr
+ * one ref held by the caller trying to kill us
+ * one ref grabbed by inotify_idr_find
+ */
+ if (unlikely(atomic_read(&i_mark->fsn_mark.refcnt) < 3)) {
+ printk(KERN_ERR "%s: i_mark=%p i_mark->wd=%d i_mark->group=%p"
+ " i_mark->inode=%p\n", __func__, i_mark, i_mark->wd,
+ i_mark->fsn_mark.group, i_mark->fsn_mark.i.inode);
+ /* we can't really recover with bad ref cnting.. */
+ BUG();
+ }
- /* removed from the idr, drop that ref */
- fsnotify_put_mark(entry);
+ do_inotify_remove_from_idr(group, i_mark);
out:
- spin_unlock(&group->inotify_data.idr_lock);
+ /* match the ref taken by inotify_idr_find_locked() */
+ if (found_i_mark)
+ fsnotify_put_mark(&found_i_mark->fsn_mark);
+ i_mark->wd = -1;
+ spin_unlock(idr_lock);
}
/*
* Send IN_IGNORED for this wd, remove this wd from the idr.
*/
-void inotify_ignored_and_remove_idr(struct fsnotify_mark_entry *entry,
+void inotify_ignored_and_remove_idr(struct fsnotify_mark *fsn_mark,
struct fsnotify_group *group)
{
- struct inotify_inode_mark_entry *ientry;
- struct fsnotify_event *ignored_event;
+ struct inotify_inode_mark *i_mark;
+ struct fsnotify_event *ignored_event, *notify_event;
struct inotify_event_private_data *event_priv;
struct fsnotify_event_private_data *fsn_event_priv;
int ret;
@@ -420,7 +527,7 @@ void inotify_ignored_and_remove_idr(struct fsnotify_mark_entry *entry,
if (!ignored_event)
return;
- ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry);
+ i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
event_priv = kmem_cache_alloc(event_priv_cachep, GFP_NOFS);
if (unlikely(!event_priv))
@@ -429,37 +536,44 @@ void inotify_ignored_and_remove_idr(struct fsnotify_mark_entry *entry,
fsn_event_priv = &event_priv->fsnotify_event_priv_data;
fsn_event_priv->group = group;
- event_priv->wd = ientry->wd;
-
- ret = fsnotify_add_notify_event(group, ignored_event, fsn_event_priv);
- if (ret)
+ event_priv->wd = i_mark->wd;
+
+ notify_event = fsnotify_add_notify_event(group, ignored_event, fsn_event_priv, NULL);
+ if (notify_event) {
+ if (IS_ERR(notify_event))
+ ret = PTR_ERR(notify_event);
+ else
+ fsnotify_put_event(notify_event);
inotify_free_event_priv(fsn_event_priv);
+ }
skip_send_ignore:
/* matches the reference taken when the event was created */
fsnotify_put_event(ignored_event);
- /* remove this entry from the idr */
- inotify_remove_from_idr(group, ientry);
+ /* remove this mark from the idr */
+ inotify_remove_from_idr(group, i_mark);
atomic_dec(&group->inotify_data.user->inotify_watches);
}
/* ding dong the mark is dead */
-static void inotify_free_mark(struct fsnotify_mark_entry *entry)
+static void inotify_free_mark(struct fsnotify_mark *fsn_mark)
{
- struct inotify_inode_mark_entry *ientry = (struct inotify_inode_mark_entry *)entry;
+ struct inotify_inode_mark *i_mark;
+
+ i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
- kmem_cache_free(inotify_inode_mark_cachep, ientry);
+ kmem_cache_free(inotify_inode_mark_cachep, i_mark);
}
static int inotify_update_existing_watch(struct fsnotify_group *group,
struct inode *inode,
u32 arg)
{
- struct fsnotify_mark_entry *entry;
- struct inotify_inode_mark_entry *ientry;
+ struct fsnotify_mark *fsn_mark;
+ struct inotify_inode_mark *i_mark;
__u32 old_mask, new_mask;
__u32 mask;
int add = (arg & IN_MASK_ADD);
@@ -467,52 +581,43 @@ static int inotify_update_existing_watch(struct fsnotify_group *group,
/* don't allow invalid bits: we don't want flags set */
mask = inotify_arg_to_mask(arg);
- if (unlikely(!mask))
+ if (unlikely(!(mask & IN_ALL_EVENTS)))
return -EINVAL;
- spin_lock(&inode->i_lock);
- entry = fsnotify_find_mark_entry(group, inode);
- spin_unlock(&inode->i_lock);
- if (!entry)
+ fsn_mark = fsnotify_find_inode_mark(group, inode);
+ if (!fsn_mark)
return -ENOENT;
- ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry);
+ i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
- spin_lock(&entry->lock);
+ spin_lock(&fsn_mark->lock);
- old_mask = entry->mask;
- if (add) {
- entry->mask |= mask;
- new_mask = entry->mask;
- } else {
- entry->mask = mask;
- new_mask = entry->mask;
- }
+ old_mask = fsn_mark->mask;
+ if (add)
+ fsnotify_set_mark_mask_locked(fsn_mark, (fsn_mark->mask | mask));
+ else
+ fsnotify_set_mark_mask_locked(fsn_mark, mask);
+ new_mask = fsn_mark->mask;
- spin_unlock(&entry->lock);
+ spin_unlock(&fsn_mark->lock);
if (old_mask != new_mask) {
/* more bits in old than in new? */
int dropped = (old_mask & ~new_mask);
- /* more bits in this entry than the inode's mask? */
+ /* more bits in this fsn_mark than the inode's mask? */
int do_inode = (new_mask & ~inode->i_fsnotify_mask);
- /* more bits in this entry than the group? */
- int do_group = (new_mask & ~group->mask);
- /* update the inode with this new entry */
+ /* update the inode with this new fsn_mark */
if (dropped || do_inode)
fsnotify_recalc_inode_mask(inode);
- /* update the group mask with the new mask */
- if (dropped || do_group)
- fsnotify_recalc_group_mask(group);
}
/* return the wd */
- ret = ientry->wd;
+ ret = i_mark->wd;
- /* match the get from fsnotify_find_mark_entry() */
- fsnotify_put_mark(entry);
+ /* match the get from fsnotify_find_mark() */
+ fsnotify_put_mark(fsn_mark);
return ret;
}
@@ -521,73 +626,51 @@ static int inotify_new_watch(struct fsnotify_group *group,
struct inode *inode,
u32 arg)
{
- struct inotify_inode_mark_entry *tmp_ientry;
+ struct inotify_inode_mark *tmp_i_mark;
__u32 mask;
int ret;
+ struct idr *idr = &group->inotify_data.idr;
+ spinlock_t *idr_lock = &group->inotify_data.idr_lock;
/* don't allow invalid bits: we don't want flags set */
mask = inotify_arg_to_mask(arg);
- if (unlikely(!mask))
+ if (unlikely(!(mask & IN_ALL_EVENTS)))
return -EINVAL;
- tmp_ientry = kmem_cache_alloc(inotify_inode_mark_cachep, GFP_KERNEL);
- if (unlikely(!tmp_ientry))
+ tmp_i_mark = kmem_cache_alloc(inotify_inode_mark_cachep, GFP_KERNEL);
+ if (unlikely(!tmp_i_mark))
return -ENOMEM;
- fsnotify_init_mark(&tmp_ientry->fsn_entry, inotify_free_mark);
- tmp_ientry->fsn_entry.mask = mask;
- tmp_ientry->wd = -1;
+ fsnotify_init_mark(&tmp_i_mark->fsn_mark, inotify_free_mark);
+ tmp_i_mark->fsn_mark.mask = mask;
+ tmp_i_mark->wd = -1;
ret = -ENOSPC;
if (atomic_read(&group->inotify_data.user->inotify_watches) >= inotify_max_user_watches)
goto out_err;
-retry:
- ret = -ENOMEM;
- if (unlikely(!idr_pre_get(&group->inotify_data.idr, GFP_KERNEL)))
- goto out_err;
- /* we are putting the mark on the idr, take a reference */
- fsnotify_get_mark(&tmp_ientry->fsn_entry);
-
- spin_lock(&group->inotify_data.idr_lock);
- ret = idr_get_new_above(&group->inotify_data.idr, &tmp_ientry->fsn_entry,
- group->inotify_data.last_wd+1,
- &tmp_ientry->wd);
- spin_unlock(&group->inotify_data.idr_lock);
- if (ret) {
- /* we didn't get on the idr, drop the idr reference */
- fsnotify_put_mark(&tmp_ientry->fsn_entry);
-
- /* idr was out of memory allocate and try again */
- if (ret == -EAGAIN)
- goto retry;
+ ret = inotify_add_to_idr(idr, idr_lock, &group->inotify_data.last_wd,
+ tmp_i_mark);
+ if (ret)
goto out_err;
- }
/* we are on the idr, now get on the inode */
- ret = fsnotify_add_mark(&tmp_ientry->fsn_entry, group, inode);
+ ret = fsnotify_add_mark(&tmp_i_mark->fsn_mark, group, inode, NULL, 0);
if (ret) {
/* we failed to get on the inode, get off the idr */
- inotify_remove_from_idr(group, tmp_ientry);
+ inotify_remove_from_idr(group, tmp_i_mark);
goto out_err;
}
- /* update the idr hint, who cares about races, it's just a hint */
- group->inotify_data.last_wd = tmp_ientry->wd;
-
/* increment the number of watches the user has */
atomic_inc(&group->inotify_data.user->inotify_watches);
- /* return the watch descriptor for this new entry */
- ret = tmp_ientry->wd;
-
- /* if this mark added a new event update the group mask */
- if (mask & ~group->mask)
- fsnotify_recalc_group_mask(group);
+ /* return the watch descriptor for this new mark */
+ ret = tmp_i_mark->wd;
out_err:
- /* match the ref from fsnotify_init_markentry() */
- fsnotify_put_mark(&tmp_ientry->fsn_entry);
+ /* match the ref from fsnotify_init_mark() */
+ fsnotify_put_mark(&tmp_i_mark->fsn_mark);
return ret;
}
@@ -616,11 +699,8 @@ retry:
static struct fsnotify_group *inotify_new_group(struct user_struct *user, unsigned int max_events)
{
struct fsnotify_group *group;
- unsigned int grp_num;
- /* fsnotify_obtain_group took a reference to group, we put this when we kill the file in the end */
- grp_num = (INOTIFY_GROUP_NUM - atomic_inc_return(&inotify_grp_num));
- group = fsnotify_obtain_group(grp_num, 0, &inotify_fsnotify_ops);
+ group = fsnotify_alloc_group(&inotify_fsnotify_ops);
if (IS_ERR(group))
return group;
@@ -726,7 +806,7 @@ fput_and_out:
SYSCALL_DEFINE2(inotify_rm_watch, int, fd, __s32, wd)
{
struct fsnotify_group *group;
- struct fsnotify_mark_entry *entry;
+ struct inotify_inode_mark *i_mark;
struct file *filp;
int ret = 0, fput_needed;
@@ -735,25 +815,23 @@ SYSCALL_DEFINE2(inotify_rm_watch, int, fd, __s32, wd)
return -EBADF;
/* verify that this is indeed an inotify instance */
- if (unlikely(filp->f_op != &inotify_fops)) {
- ret = -EINVAL;
+ ret = -EINVAL;
+ if (unlikely(filp->f_op != &inotify_fops))
goto out;
- }
group = filp->private_data;
- spin_lock(&group->inotify_data.idr_lock);
- entry = idr_find(&group->inotify_data.idr, wd);
- if (unlikely(!entry)) {
- spin_unlock(&group->inotify_data.idr_lock);
- ret = -EINVAL;
+ ret = -EINVAL;
+ i_mark = inotify_idr_find(group, wd);
+ if (unlikely(!i_mark))
goto out;
- }
- fsnotify_get_mark(entry);
- spin_unlock(&group->inotify_data.idr_lock);
- fsnotify_destroy_mark_by_entry(entry);
- fsnotify_put_mark(entry);
+ ret = 0;
+
+ fsnotify_destroy_mark(&i_mark->fsn_mark);
+
+ /* match ref taken by inotify_idr_find */
+ fsnotify_put_mark(&i_mark->fsn_mark);
out:
fput_light(filp, fput_needed);
@@ -767,7 +845,28 @@ out:
*/
static int __init inotify_user_setup(void)
{
- inotify_inode_mark_cachep = KMEM_CACHE(inotify_inode_mark_entry, SLAB_PANIC);
+ BUILD_BUG_ON(IN_ACCESS != FS_ACCESS);
+ BUILD_BUG_ON(IN_MODIFY != FS_MODIFY);
+ BUILD_BUG_ON(IN_ATTRIB != FS_ATTRIB);
+ BUILD_BUG_ON(IN_CLOSE_WRITE != FS_CLOSE_WRITE);
+ BUILD_BUG_ON(IN_CLOSE_NOWRITE != FS_CLOSE_NOWRITE);
+ BUILD_BUG_ON(IN_OPEN != FS_OPEN);
+ BUILD_BUG_ON(IN_MOVED_FROM != FS_MOVED_FROM);
+ BUILD_BUG_ON(IN_MOVED_TO != FS_MOVED_TO);
+ BUILD_BUG_ON(IN_CREATE != FS_CREATE);
+ BUILD_BUG_ON(IN_DELETE != FS_DELETE);
+ BUILD_BUG_ON(IN_DELETE_SELF != FS_DELETE_SELF);
+ BUILD_BUG_ON(IN_MOVE_SELF != FS_MOVE_SELF);
+ BUILD_BUG_ON(IN_UNMOUNT != FS_UNMOUNT);
+ BUILD_BUG_ON(IN_Q_OVERFLOW != FS_Q_OVERFLOW);
+ BUILD_BUG_ON(IN_IGNORED != FS_IN_IGNORED);
+ BUILD_BUG_ON(IN_EXCL_UNLINK != FS_EXCL_UNLINK);
+ BUILD_BUG_ON(IN_ISDIR != FS_IN_ISDIR);
+ BUILD_BUG_ON(IN_ONESHOT != FS_IN_ONESHOT);
+
+ BUG_ON(hweight32(ALL_INOTIFY_BITS) != 21);
+
+ inotify_inode_mark_cachep = KMEM_CACHE(inotify_inode_mark, SLAB_PANIC);
event_priv_cachep = KMEM_CACHE(inotify_event_private_data, SLAB_PANIC);
inotify_max_queued_events = 16384;
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