infrastructure work to add and remove marks on vfsmounts. This should get
every set up except wiring the functions to the syscalls.
Signed-off-by: Eric Paris <eparis@xxxxxxxxxx>
---
fs/notify/fanotify/fanotify_user.c | 185 ++++++++++++++++++++++++++----------
1 files changed, 133 insertions(+), 52 deletions(-)
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 79376ec..f5bf1db 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -300,31 +300,83 @@ out:
return ret;
}
-static int fanotify_remove_mark(struct fsnotify_group *group,
- struct inode *inode,
- __u32 mask)
+static void fanotify_update_object_mask(struct fsnotify_group *group,
+ struct inode *inode,
+ struct vfsmount *mnt,
+ struct fsnotify_mark *fsn_mark,
+ unsigned int flags,
+ __u32 mask)
{
- struct fsnotify_mark *fsn_mark;
- __u32 new_mask;
-
- pr_debug("%s: group=%p inode=%p mask=%x\n", __func__,
- group, inode, mask);
+ __u32 old_mask, new_mask;
- fsn_mark = fsnotify_find_inode_mark(group, inode);
- if (!fsn_mark)
- return -ENOENT;
+ pr_debug("%s: group=%p inode=%p mnt=%p fsn_mark=%p flags=%x mask=%x\n",
+ __func__, group, inode, mnt, fsn_mark, flags, mask);
spin_lock(&fsn_mark->lock);
- fsn_mark->mask &= ~mask;
+ old_mask = fsn_mark->mask;
+ if (flags & FAN_MARK_ADD)
+ fsn_mark->mask |= mask;
+ else if (flags & FAN_MARK_REMOVE)
+ fsn_mark->mask &= ~mask;
+ else
+ BUG();
new_mask = fsn_mark->mask;
spin_unlock(&fsn_mark->lock);
if (!new_mask)
fsnotify_destroy_mark(fsn_mark);
+
+ /* we made changes to a mask, update the group mask and the object mask
+ * so things happen quickly. */
+ if (old_mask != new_mask) {
+ __u32 dropped, do_object, do_group;
+
+ /* more bits in old than in new? */
+ dropped = (old_mask & ~new_mask);
+ /* more bits in this fsn_mark than the group? */
+ do_group = (new_mask & ~group->mask);
+
+ if (inode) {
+ /* more bits in this fsn_mark than the object's mask? */
+ do_object = (new_mask & ~inode->i_fsnotify_mask);
+ /* update the object with this new fsn_mark */
+ if (dropped || do_object)
+ fsnotify_recalc_inode_mask(inode);
+ } else if (mnt) {
+ /* more bits in this fsn_mark than the object's mask? */
+ do_object = (new_mask & ~mnt->mnt_fsnotify_mask);
+ /* update the object with this new fsn_mark */
+ if (dropped || do_object)
+ fsnotify_recalc_vfsmount_mask(mnt);
+ } else {
+ BUG();
+ }
+
+ /* update the group mask with the new mask */
+ if (dropped || do_group)
+ fsnotify_recalc_group_mask(group);
+ }
+}
+
+static int fanotify_remove_mark(struct fsnotify_group *group, struct inode *inode,
+ struct vfsmount *mnt, unsigned int flags, __u32 mask)
+{
+ struct fsnotify_mark *fsn_mark = NULL;
+
+ BUG_ON(inode && mnt);
+ BUG_ON(!inode && !mnt);
+
+ if (inode)
+ fsn_mark = fsnotify_find_inode_mark(group, inode);
+ else if (mnt)
+ fsn_mark = fsnotify_find_vfsmount_mark(group, mnt);
else
- fsnotify_recalc_inode_mask(inode);
+ BUG();
- fsnotify_recalc_group_mask(group);
+ if (!fsn_mark)
+ return -ENOENT;
+
+ fanotify_update_object_mask(group, inode, mnt, fsn_mark, flags, mask);
/* matches the fsnotify_find_inode_mark() */
fsnotify_put_mark(fsn_mark);
@@ -332,22 +384,48 @@ static int fanotify_remove_mark(struct fsnotify_group *group,
return 0;
}
-static int fanotify_add_mark(struct fsnotify_group *group,
- struct inode *inode,
- __u32 mask)
+static struct fsnotify_mark *fanotify_add_vfsmount_mark(struct fsnotify_group *group,
+ struct vfsmount *mnt)
{
struct fsnotify_mark *fsn_mark;
- __u32 old_mask, new_mask;
- int ret;
- pr_debug("%s: group=%p inode=%p mask=%x\n", __func__,
- group, inode, mask);
+ fsn_mark = fsnotify_find_vfsmount_mark(group, mnt);
+ if (!fsn_mark) {
+ struct fsnotify_mark *new_fsn_mark;
+ int ret;
+
+ fsn_mark = ERR_PTR(-ENOMEM);
+ new_fsn_mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
+ if (!new_fsn_mark)
+ goto out;
+
+ fsnotify_init_mark(new_fsn_mark, fanotify_free_mark);
+ ret = fsnotify_add_mark(new_fsn_mark, group, NULL, mnt, 0);
+ if (ret) {
+ fsn_mark = ERR_PTR(ret);
+ fanotify_free_mark(new_fsn_mark);
+ goto out;
+ }
+
+ fsn_mark = new_fsn_mark;
+ }
+out:
+ return fsn_mark;
+}
+
+static struct fsnotify_mark *fanotify_add_inode_mark(struct fsnotify_group *group,
+ struct inode *inode)
+{
+ struct fsnotify_mark *fsn_mark;
+
+ pr_debug("%s: group=%p inode=%p\n", __func__, group, inode);
fsn_mark = fsnotify_find_inode_mark(group, inode);
if (!fsn_mark) {
struct fsnotify_mark *new_fsn_mark;
+ int ret;
- ret = -ENOMEM;
+ fsn_mark = ERR_PTR(-ENOMEM);
new_fsn_mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
if (!new_fsn_mark)
goto out;
@@ -355,57 +433,60 @@ static int fanotify_add_mark(struct fsnotify_group *group,
fsnotify_init_mark(new_fsn_mark, fanotify_free_mark);
ret = fsnotify_add_mark(new_fsn_mark, group, inode, NULL, 0);
if (ret) {
+ fsn_mark = ERR_PTR(ret);
fanotify_free_mark(new_fsn_mark);
goto out;
}
fsn_mark = new_fsn_mark;
}
+out:
+ return fsn_mark;
+}
- ret = 0;
+static int fanotify_add_mark(struct fsnotify_group *group, struct inode *inode,
+ struct vfsmount *mnt, unsigned int flags, __u32 mask)
+{
+ struct fsnotify_mark *fsn_mark;
- spin_lock(&fsn_mark->lock);
- old_mask = fsn_mark->mask;
- fsn_mark->mask |= mask;
- new_mask = fsn_mark->mask;
- spin_unlock(&fsn_mark->lock);
+ pr_debug("%s: group=%p inode=%p mnt=%p flags=%x mask=%x\n",
+ __func__, group, inode, mnt, flags, mask);
- /* we made changes to a mask, update the group mask and the inode mask
- * so things happen quickly. */
- if (old_mask != new_mask) {
- /* more bits in old than in new? */
- int dropped = (old_mask & ~new_mask);
- /* more bits in this mark than the inode's mask? */
- int do_inode = (new_mask & ~inode->i_fsnotify_mask);
- /* more bits in this mark than the group? */
- int do_group = (new_mask & ~group->mask);
+ BUG_ON(inode && mnt);
+ BUG_ON(!inode && !mnt);
- /* update the inode with this new mark */
- if (dropped || do_inode)
- fsnotify_recalc_inode_mask(inode);
+ if (inode)
+ fsn_mark = fanotify_add_inode_mark(group, inode);
+ else if (mnt)
+ fsn_mark = fanotify_add_vfsmount_mark(group, mnt);
+ else
+ BUG();
- /* update the group mask with the new mask */
- if (dropped || do_group)
- fsnotify_recalc_group_mask(group);
- }
+ if (IS_ERR(fsn_mark))
+ goto out;
+
+ fanotify_update_object_mask(group, inode, mnt, fsn_mark, flags, mask);
/* match the init or the find.... */
fsnotify_put_mark(fsn_mark);
out:
- return ret;
+ return PTR_ERR(fsn_mark);
}
static int fanotify_update_mark(struct fsnotify_group *group,
- struct inode *inode, int flags,
- __u32 mask)
+ struct inode *inode, struct vfsmount *mnt,
+ int flags, __u32 mask)
{
- pr_debug("%s: group=%p inode=%p flags=%x mask=%x\n", __func__,
- group, inode, flags, mask);
+ pr_debug("%s: group=%p inode=%p mnt=%p flags=%x mask=%x\n",
+ __func__, group, inode, mnt, flags, mask);
+
+ BUG_ON(inode && mnt);
+ BUG_ON(!inode && !mnt);
if (flags & FAN_MARK_ADD)
- fanotify_add_mark(group, inode, mask);
+ fanotify_add_mark(group, inode, mnt, flags, mask);
else if (flags & FAN_MARK_REMOVE)
- fanotify_remove_mark(group, inode, mask);
+ fanotify_remove_mark(group, inode, mnt, flags, mask);
else
BUG();
@@ -507,7 +588,7 @@ SYSCALL_DEFINE(fanotify_mark)(int fanotify_fd, unsigned int flags,
group = filp->private_data;
/* create/update an inode mark */
- ret = fanotify_update_mark(group, inode, flags, mask);
+ ret = fanotify_update_mark(group, inode, NULL, flags, mask);
path_put(&path);
fput_and_out:
--
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