Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notify

* 'for-linus' of git://git.infradead.org/users/eparis/notify: (22 commits)
  Ensure FMODE_NONOTIFY is not set by userspace
  make fanotify_read() restartable across signals
  fsnotify: remove alignment padding from fsnotify_mark on 64 bit builds
  fs/notify/fanotify/fanotify_user.c: fix warnings
  fanotify: Fix FAN_CLOSE comments
  fanotify: do not recalculate the mask if the ignored mask changed
  fanotify: ignore events on directories unless specifically requested
  fsnotify: rename FS_IN_ISDIR to FS_ISDIR
  fanotify: do not send events for irregular files
  fanotify: limit number of listeners per user
  fanotify: allow userspace to override max marks
  fanotify: limit the number of marks in a single fanotify group
  fanotify: allow userspace to override max queue depth
  fsnotify: implement a default maximum queue depth
  fanotify: ignore fanotify ignore marks if open writers
  fanotify: allow userspace to flush all marks
  fsnotify: call fsnotify_parent in perm events
  fsnotify: correctly handle return codes from listeners
  fanotify: use __aligned_u64 in fanotify userspace metadata
  fanotify: implement fanotify listener ordering
  ...

7 files changed, 146 insertions, 33 deletions

diff --git a/fs/notify/Kconfig b/fs/notify/Kconfig
index b388443c3a09..22c629eedd82 100644
--- a/fs/notify/Kconfig
+++ b/fs/notify/Kconfig
@@ -3,4 +3,4 @@ config FSNOTIFY
 
 source "fs/notify/dnotify/Kconfig"
 source "fs/notify/inotify/Kconfig"
-#source "fs/notify/fanotify/Kconfig"
+source "fs/notify/fanotify/Kconfig"
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index 85366c78cc37..b04f88eed09e 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -131,6 +131,7 @@ static int fanotify_handle_event(struct fsnotify_group *group,
         BUILD_BUG_ON(FAN_Q_OVERFLOW != FS_Q_OVERFLOW);
         BUILD_BUG_ON(FAN_OPEN_PERM != FS_OPEN_PERM);
         BUILD_BUG_ON(FAN_ACCESS_PERM != FS_ACCESS_PERM);
+        BUILD_BUG_ON(FAN_ONDIR != FS_ISDIR);
 
         pr_debug("%s: group=%p event=%p\n", __func__, group, event);
 
@@ -160,20 +161,21 @@ static bool fanotify_should_send_event(struct fsnotify_group *group,
                                        __u32 event_mask, void *data, int data_type)
 {
         __u32 marks_mask, marks_ignored_mask;
+        struct path *path = data;
 
         pr_debug("%s: group=%p to_tell=%p inode_mark=%p vfsmnt_mark=%p "
                  "mask=%x data=%p data_type=%d\n", __func__, group, to_tell,
                  inode_mark, vfsmnt_mark, event_mask, data, data_type);
 
-        /* sorry, fanotify only gives a damn about files and dirs */
-        if (!S_ISREG(to_tell->i_mode) &&
-            !S_ISDIR(to_tell->i_mode))
-                return false;
-
         /* if we don't have enough info to send an event to userspace say no */
         if (data_type != FSNOTIFY_EVENT_PATH)
                 return false;
 
+        /* sorry, fanotify only gives a damn about files and dirs */
+        if (!S_ISREG(path->dentry->d_inode->i_mode) &&
+            !S_ISDIR(path->dentry->d_inode->i_mode))
+                return false;
+
         if (inode_mark && vfsmnt_mark) {
                 marks_mask = (vfsmnt_mark->mask | inode_mark->mask);
                 marks_ignored_mask = (vfsmnt_mark->ignored_mask | inode_mark->ignored_mask);
@@ -194,16 +196,29 @@ static bool fanotify_should_send_event(struct fsnotify_group *group,
                 BUG();
         }
 
+        if (S_ISDIR(path->dentry->d_inode->i_mode) &&
+            (marks_ignored_mask & FS_ISDIR))
+                return false;
+
         if (event_mask & marks_mask & ~marks_ignored_mask)
                 return true;
 
         return false;
 }
 
+static void fanotify_free_group_priv(struct fsnotify_group *group)
+{
+        struct user_struct *user;
+
+        user = group->fanotify_data.user;
+        atomic_dec(&user->fanotify_listeners);
+        free_uid(user);
+}
+
 const struct fsnotify_ops fanotify_fsnotify_ops = {
         .handle_event = fanotify_handle_event,
         .should_send_event = fanotify_should_send_event,
-        .free_group_priv = NULL,
+        .free_group_priv = fanotify_free_group_priv,
         .free_event_priv = NULL,
         .freeing_mark = NULL,
 };
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index bbcb98e7fcc6..063224812b7e 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -16,6 +16,10 @@
 
 #include <asm/ioctls.h>
 
+#define FANOTIFY_DEFAULT_MAX_EVENTS     16384
+#define FANOTIFY_DEFAULT_MAX_MARKS      8192
+#define FANOTIFY_DEFAULT_MAX_LISTENERS  128
+
 extern const struct fsnotify_ops fanotify_fsnotify_ops;
 
 static struct kmem_cache *fanotify_mark_cache __read_mostly;
@@ -326,7 +330,7 @@ static ssize_t fanotify_read(struct file *file, char __user *buf,
                 ret = -EAGAIN;
                 if (file->f_flags & O_NONBLOCK)
                         break;
-                ret = -EINTR;
+                ret = -ERESTARTSYS;
                 if (signal_pending(current))
                         break;
 
@@ -372,11 +376,10 @@ static ssize_t fanotify_write(struct file *file, const char __user *buf, size_t
 static int fanotify_release(struct inode *ignored, struct file *file)
 {
         struct fsnotify_group *group = file->private_data;
-        struct fanotify_response_event *re, *lre;
-
-        pr_debug("%s: file=%p group=%p\n", __func__, file, group);
 
 #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
+        struct fanotify_response_event *re, *lre;
+
         mutex_lock(&group->fanotify_data.access_mutex);
 
         group->fanotify_data.bypass_perm = true;
@@ -554,18 +557,24 @@ static __u32 fanotify_mark_add_to_mask(struct fsnotify_mark *fsn_mark,
                                        __u32 mask,
                                        unsigned int flags)
 {
-        __u32 oldmask;
+        __u32 oldmask = -1;
 
         spin_lock(&fsn_mark->lock);
         if (!(flags & FAN_MARK_IGNORED_MASK)) {
                 oldmask = fsn_mark->mask;
                 fsnotify_set_mark_mask_locked(fsn_mark, (oldmask | mask));
         } else {
-                oldmask = fsn_mark->ignored_mask;
-                fsnotify_set_mark_ignored_mask_locked(fsn_mark, (oldmask | mask));
+                __u32 tmask = fsn_mark->ignored_mask | mask;
+                fsnotify_set_mark_ignored_mask_locked(fsn_mark, tmask);
                 if (flags & FAN_MARK_IGNORED_SURV_MODIFY)
                         fsn_mark->flags |= FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY;
         }
+
+        if (!(flags & FAN_MARK_ONDIR)) {
+                __u32 tmask = fsn_mark->ignored_mask | FAN_ONDIR;
+                fsnotify_set_mark_ignored_mask_locked(fsn_mark, tmask);
+        }
+
         spin_unlock(&fsn_mark->lock);
 
         return mask & ~oldmask;
@@ -582,6 +591,9 @@ static int fanotify_add_vfsmount_mark(struct fsnotify_group *group,
         if (!fsn_mark) {
                 int ret;
 
+                if (atomic_read(&group->num_marks) > group->fanotify_data.max_marks)
+                        return -ENOSPC;
+
                 fsn_mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
                 if (!fsn_mark)
                         return -ENOMEM;
@@ -610,10 +622,23 @@ static int fanotify_add_inode_mark(struct fsnotify_group *group,
 
         pr_debug("%s: group=%p inode=%p\n", __func__, group, inode);
 
+        /*
+         * If some other task has this inode open for write we should not add
+         * an ignored mark, unless that ignored mark is supposed to survive
+         * modification changes anyway.
+         */
+        if ((flags & FAN_MARK_IGNORED_MASK) &&
+            !(flags & FAN_MARK_IGNORED_SURV_MODIFY) &&
+            (atomic_read(&inode->i_writecount) > 0))
+                return 0;
+
         fsn_mark = fsnotify_find_inode_mark(group, inode);
         if (!fsn_mark) {
                 int ret;
 
+                if (atomic_read(&group->num_marks) > group->fanotify_data.max_marks)
+                        return -ENOSPC;
+
                 fsn_mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
                 if (!fsn_mark)
                         return -ENOMEM;
@@ -637,6 +662,7 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
 {
         struct fsnotify_group *group;
         int f_flags, fd;
+        struct user_struct *user;
 
         pr_debug("%s: flags=%d event_f_flags=%d\n",
                 __func__, flags, event_f_flags);
@@ -647,6 +673,12 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
         if (flags & ~FAN_ALL_INIT_FLAGS)
                 return -EINVAL;
 
+        user = get_current_user();
+        if (atomic_read(&user->fanotify_listeners) > FANOTIFY_DEFAULT_MAX_LISTENERS) {
+                free_uid(user);
+                return -EMFILE;
+        }
+
         f_flags = O_RDWR | FMODE_NONOTIFY;
         if (flags & FAN_CLOEXEC)
                 f_flags |= O_CLOEXEC;
@@ -658,12 +690,47 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
         if (IS_ERR(group))
                 return PTR_ERR(group);
 
+        group->fanotify_data.user = user;
+        atomic_inc(&user->fanotify_listeners);
+
         group->fanotify_data.f_flags = event_f_flags;
 #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
         mutex_init(&group->fanotify_data.access_mutex);
         init_waitqueue_head(&group->fanotify_data.access_waitq);
         INIT_LIST_HEAD(&group->fanotify_data.access_list);
 #endif
+        switch (flags & FAN_ALL_CLASS_BITS) {
+        case FAN_CLASS_NOTIF:
+                group->priority = FS_PRIO_0;
+                break;
+        case FAN_CLASS_CONTENT:
+                group->priority = FS_PRIO_1;
+                break;
+        case FAN_CLASS_PRE_CONTENT:
+                group->priority = FS_PRIO_2;
+                break;
+        default:
+                fd = -EINVAL;
+                goto out_put_group;
+        }
+
+        if (flags & FAN_UNLIMITED_QUEUE) {
+                fd = -EPERM;
+                if (!capable(CAP_SYS_ADMIN))
+                        goto out_put_group;
+                group->max_events = UINT_MAX;
+        } else {
+                group->max_events = FANOTIFY_DEFAULT_MAX_EVENTS;
+        }
+
+        if (flags & FAN_UNLIMITED_MARKS) {
+                fd = -EPERM;
+                if (!capable(CAP_SYS_ADMIN))
+                        goto out_put_group;
+                group->fanotify_data.max_marks = UINT_MAX;
+        } else {
+                group->fanotify_data.max_marks = FANOTIFY_DEFAULT_MAX_MARKS;
+        }
 
         fd = anon_inode_getfd("[fanotify]", &fanotify_fops, group, f_flags);
         if (fd < 0)
@@ -704,6 +771,12 @@ SYSCALL_DEFINE(fanotify_mark)(int fanotify_fd, unsigned int flags,
         default:
                 return -EINVAL;
         }
+
+        if (mask & FAN_ONDIR) {
+                flags |= FAN_MARK_ONDIR;
+                mask &= ~FAN_ONDIR;
+        }
+
 #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
         if (mask & ~(FAN_ALL_EVENTS | FAN_ALL_PERM_EVENTS | FAN_EVENT_ON_CHILD))
 #else
@@ -719,6 +792,16 @@ SYSCALL_DEFINE(fanotify_mark)(int fanotify_fd, unsigned int flags,
         ret = -EINVAL;
         if (unlikely(filp->f_op != &fanotify_fops))
                 goto fput_and_out;
+        group = filp->private_data;
+
+        /*
+         * group->priority == FS_PRIO_0 == FAN_CLASS_NOTIF.  These are not
+         * allowed to set permissions events.
+         */
+        ret = -EINVAL;
+        if (mask & FAN_ALL_PERM_EVENTS &&
+            group->priority == FS_PRIO_0)
+                goto fput_and_out;
 
         ret = fanotify_find_path(dfd, pathname, &path, flags);
         if (ret)
@@ -729,7 +812,6 @@ SYSCALL_DEFINE(fanotify_mark)(int fanotify_fd, unsigned int flags,
                 inode = path.dentry->d_inode;
         else
                 mnt = path.mnt;
-        group = filp->private_data;
 
         /* create/update an inode mark */
         switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE | FAN_MARK_FLUSH)) {
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 4498a208df94..20dc218707ca 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -84,16 +84,17 @@ void __fsnotify_update_child_dentry_flags(struct inode *inode)
 }
 
 /* Notify this dentry's parent about a child's events. */
-void __fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask)
+int __fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask)
 {
         struct dentry *parent;
         struct inode *p_inode;
+        int ret = 0;
 
         if (!dentry)
                 dentry = path->dentry;
 
         if (!(dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED))
-                return;
+                return 0;
 
         parent = dget_parent(dentry);
         p_inode = parent->d_inode;
@@ -106,14 +107,16 @@ void __fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask)
                 mask |= FS_EVENT_ON_CHILD;
 
                 if (path)
-                        fsnotify(p_inode, mask, path, FSNOTIFY_EVENT_PATH,
-                                 dentry->d_name.name, 0);
+                        ret = fsnotify(p_inode, mask, path, FSNOTIFY_EVENT_PATH,
+                                       dentry->d_name.name, 0);
                 else
-                        fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE,
-                                 dentry->d_name.name, 0);
+                        ret = fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE,
+                                       dentry->d_name.name, 0);
         }
 
         dput(parent);
+
+        return ret;
 }
 EXPORT_SYMBOL_GPL(__fsnotify_parent);
 
@@ -252,20 +255,23 @@ int fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is,
 
                 if (inode_group > vfsmount_group) {
                         /* handle inode */
-                        send_to_group(to_tell, NULL, inode_mark, NULL, mask, data,
-                                      data_is, cookie, file_name, &event);
+                        ret = send_to_group(to_tell, NULL, inode_mark, NULL, mask, data,
+                                            data_is, cookie, file_name, &event);
                         /* we didn't use the vfsmount_mark */
                         vfsmount_group = NULL;
                 } else if (vfsmount_group > inode_group) {
-                        send_to_group(to_tell, mnt, NULL, vfsmount_mark, mask, data,
-                                      data_is, cookie, file_name, &event);
+                        ret = send_to_group(to_tell, mnt, NULL, vfsmount_mark, mask, data,
+                                            data_is, cookie, file_name, &event);
                         inode_group = NULL;
                 } else {
-                        send_to_group(to_tell, mnt, inode_mark, vfsmount_mark,
-                                      mask, data, data_is, cookie, file_name,
-                                      &event);
+                        ret = send_to_group(to_tell, mnt, inode_mark, vfsmount_mark,
+                                            mask, data, data_is, cookie, file_name,
+                                            &event);
                 }
 
+                if (ret && (mask & ALL_FSNOTIFY_PERM_EVENTS))
+                        goto out;
+
                 if (inode_group)
                         inode_node = srcu_dereference(inode_node->next,
                                                       &fsnotify_mark_srcu);
@@ -273,7 +279,8 @@ int fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is,
                         vfsmount_node = srcu_dereference(vfsmount_node->next,
                                                          &fsnotify_mark_srcu);
         }
-
+        ret = 0;
+out:
         srcu_read_unlock(&fsnotify_mark_srcu, idx);
         /*
          * fsnotify_create_event() took a reference so the event can't be cleaned
diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c
index 21ed10660b80..4c29fcf557d1 100644
--- a/fs/notify/inode_mark.c
+++ b/fs/notify/inode_mark.c
@@ -177,7 +177,8 @@ void fsnotify_set_inode_mark_mask_locked(struct fsnotify_mark *mark,
  * Attach an initialized mark to a given inode.
  * These marks may be used for the fsnotify backend to determine which
  * event types should be delivered to which group and for which inodes.  These
- * marks are ordered according to the group's location in memory.
+ * marks are ordered according to priority, highest number first, and then by
+ * the group's location in memory.
  */
 int fsnotify_add_inode_mark(struct fsnotify_mark *mark,
                             struct fsnotify_group *group, struct inode *inode,
@@ -211,7 +212,11 @@ int fsnotify_add_inode_mark(struct fsnotify_mark *mark,
                         goto out;
                 }
 
-                if (mark->group < lmark->group)
+                if (mark->group->priority < lmark->group->priority)
+                        continue;
+
+                if ((mark->group->priority == lmark->group->priority) &&
+                    (mark->group < lmark->group))
                         continue;
 
                 hlist_add_before_rcu(&mark->i.i_list, &lmark->i.i_list);
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index 24edc1185d53..444c305a468c 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -862,7 +862,7 @@ static int __init inotify_user_setup(void)
         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_ISDIR != FS_ISDIR);
         BUILD_BUG_ON(IN_ONESHOT != FS_IN_ONESHOT);
 
         BUG_ON(hweight32(ALL_INOTIFY_BITS) != 21);
diff --git a/fs/notify/vfsmount_mark.c b/fs/notify/vfsmount_mark.c
index 56772b578fbd..85eebff6d0d7 100644
--- a/fs/notify/vfsmount_mark.c
+++ b/fs/notify/vfsmount_mark.c
@@ -169,7 +169,11 @@ int fsnotify_add_vfsmount_mark(struct fsnotify_mark *mark,
                         goto out;
                 }
 
-                if (mark->group < lmark->group)
+                if (mark->group->priority < lmark->group->priority)
+                        continue;
+
+                if ((mark->group->priority == lmark->group->priority) &&
+                    (mark->group < lmark->group))
                         continue;
 
                 hlist_add_before_rcu(&mark->m.m_list, &lmark->m.m_list);