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path: root/fs/tracefs/event_inode.c
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Diffstat (limited to 'fs/tracefs/event_inode.c')
-rw-r--r--fs/tracefs/event_inode.c223
1 files changed, 87 insertions, 136 deletions
diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c
index 0256afdd4acf..5d88c184f0fc 100644
--- a/fs/tracefs/event_inode.c
+++ b/fs/tracefs/event_inode.c
@@ -37,7 +37,6 @@ static DEFINE_MUTEX(eventfs_mutex);
struct eventfs_root_inode {
struct eventfs_inode ei;
- struct inode *parent_inode;
struct dentry *events_dir;
};
@@ -50,8 +49,12 @@ static struct eventfs_root_inode *get_root_inode(struct eventfs_inode *ei)
/* Just try to make something consistent and unique */
static int eventfs_dir_ino(struct eventfs_inode *ei)
{
- if (!ei->ino)
+ if (!ei->ino) {
ei->ino = get_next_ino();
+ /* Must not have the file inode number */
+ if (ei->ino == EVENTFS_FILE_INODE_INO)
+ ei->ino = get_next_ino();
+ }
return ei->ino;
}
@@ -207,7 +210,9 @@ static int eventfs_set_attr(struct mnt_idmap *idmap, struct dentry *dentry,
* determined by the parent directory.
*/
if (dentry->d_inode->i_mode & S_IFDIR) {
- update_attr(&ei->attr, iattr);
+ /* Just use the inode permissions for the events directory */
+ if (!ei->is_events)
+ update_attr(&ei->attr, iattr);
} else {
name = dentry->d_name.name;
@@ -225,70 +230,9 @@ static int eventfs_set_attr(struct mnt_idmap *idmap, struct dentry *dentry,
return ret;
}
-static void update_events_attr(struct eventfs_inode *ei, struct super_block *sb)
-{
- struct eventfs_root_inode *rei;
- struct inode *parent;
-
- rei = get_root_inode(ei);
-
- /* Use the parent inode permissions unless root set its permissions */
- parent = rei->parent_inode;
-
- if (rei->ei.attr.mode & EVENTFS_SAVE_UID)
- ei->attr.uid = rei->ei.attr.uid;
- else
- ei->attr.uid = parent->i_uid;
-
- if (rei->ei.attr.mode & EVENTFS_SAVE_GID)
- ei->attr.gid = rei->ei.attr.gid;
- else
- ei->attr.gid = parent->i_gid;
-}
-
-static void set_top_events_ownership(struct inode *inode)
-{
- struct tracefs_inode *ti = get_tracefs(inode);
- struct eventfs_inode *ei = ti->private;
-
- /* The top events directory doesn't get automatically updated */
- if (!ei || !ei->is_events)
- return;
-
- update_events_attr(ei, inode->i_sb);
-
- if (!(ei->attr.mode & EVENTFS_SAVE_UID))
- inode->i_uid = ei->attr.uid;
-
- if (!(ei->attr.mode & EVENTFS_SAVE_GID))
- inode->i_gid = ei->attr.gid;
-}
-
-static int eventfs_get_attr(struct mnt_idmap *idmap,
- const struct path *path, struct kstat *stat,
- u32 request_mask, unsigned int flags)
-{
- struct dentry *dentry = path->dentry;
- struct inode *inode = d_backing_inode(dentry);
-
- set_top_events_ownership(inode);
-
- generic_fillattr(idmap, request_mask, inode, stat);
- return 0;
-}
-
-static int eventfs_permission(struct mnt_idmap *idmap,
- struct inode *inode, int mask)
-{
- set_top_events_ownership(inode);
- return generic_permission(idmap, inode, mask);
-}
-
static const struct inode_operations eventfs_dir_inode_operations = {
.lookup = eventfs_root_lookup,
.setattr = eventfs_set_attr,
- .getattr = eventfs_get_attr,
- .permission = eventfs_permission,
};
static const struct inode_operations eventfs_file_inode_operations = {
@@ -301,84 +245,109 @@ static const struct file_operations eventfs_file_operations = {
.llseek = generic_file_llseek,
};
-/*
- * On a remount of tracefs, if UID or GID options are set, then
- * the mount point inode permissions should be used.
- * Reset the saved permission flags appropriately.
- */
-void eventfs_remount(struct tracefs_inode *ti, bool update_uid, bool update_gid)
+static void eventfs_set_attrs(struct eventfs_inode *ei, bool update_uid, kuid_t uid,
+ bool update_gid, kgid_t gid, int level)
{
- struct eventfs_inode *ei = ti->private;
+ struct eventfs_inode *ei_child;
- if (!ei)
+ /* Update events/<system>/<event> */
+ if (WARN_ON_ONCE(level > 3))
return;
- if (update_uid)
+ if (update_uid) {
ei->attr.mode &= ~EVENTFS_SAVE_UID;
+ ei->attr.uid = uid;
+ }
- if (update_gid)
+ if (update_gid) {
ei->attr.mode &= ~EVENTFS_SAVE_GID;
+ ei->attr.gid = gid;
+ }
+
+ list_for_each_entry(ei_child, &ei->children, list) {
+ eventfs_set_attrs(ei_child, update_uid, uid, update_gid, gid, level + 1);
+ }
if (!ei->entry_attrs)
return;
for (int i = 0; i < ei->nr_entries; i++) {
- if (update_uid)
+ if (update_uid) {
ei->entry_attrs[i].mode &= ~EVENTFS_SAVE_UID;
- if (update_gid)
+ ei->entry_attrs[i].uid = uid;
+ }
+ if (update_gid) {
ei->entry_attrs[i].mode &= ~EVENTFS_SAVE_GID;
+ ei->entry_attrs[i].gid = gid;
+ }
}
+
}
-/* Return the evenfs_inode of the "events" directory */
-static struct eventfs_inode *eventfs_find_events(struct dentry *dentry)
+/*
+ * On a remount of tracefs, if UID or GID options are set, then
+ * the mount point inode permissions should be used.
+ * Reset the saved permission flags appropriately.
+ */
+void eventfs_remount(struct tracefs_inode *ti, bool update_uid, bool update_gid)
{
- struct eventfs_inode *ei;
+ struct eventfs_inode *ei = ti->private;
- do {
- // The parent is stable because we do not do renames
- dentry = dentry->d_parent;
- // ... and directories always have d_fsdata
- ei = dentry->d_fsdata;
+ /* Only the events directory does the updates */
+ if (!ei || !ei->is_events || ei->is_freed)
+ return;
- /*
- * If the ei is being freed, the ownership of the children
- * doesn't matter.
- */
- if (ei->is_freed)
- return NULL;
+ eventfs_set_attrs(ei, update_uid, ti->vfs_inode.i_uid,
+ update_gid, ti->vfs_inode.i_gid, 0);
+}
- // Walk upwards until you find the events inode
- } while (!ei->is_events);
+static void update_inode_attr(struct inode *inode, umode_t mode,
+ struct eventfs_attr *attr, struct eventfs_root_inode *rei)
+{
+ if (attr && attr->mode & EVENTFS_SAVE_MODE)
+ inode->i_mode = attr->mode & EVENTFS_MODE_MASK;
+ else
+ inode->i_mode = mode;
- update_events_attr(ei, dentry->d_sb);
+ if (attr && attr->mode & EVENTFS_SAVE_UID)
+ inode->i_uid = attr->uid;
+ else
+ inode->i_uid = rei->ei.attr.uid;
- return ei;
+ if (attr && attr->mode & EVENTFS_SAVE_GID)
+ inode->i_gid = attr->gid;
+ else
+ inode->i_gid = rei->ei.attr.gid;
}
-static void update_inode_attr(struct dentry *dentry, struct inode *inode,
- struct eventfs_attr *attr, umode_t mode)
+static struct inode *eventfs_get_inode(struct dentry *dentry, struct eventfs_attr *attr,
+ umode_t mode, struct eventfs_inode *ei)
{
- struct eventfs_inode *events_ei = eventfs_find_events(dentry);
+ struct eventfs_root_inode *rei;
+ struct eventfs_inode *pei;
+ struct tracefs_inode *ti;
+ struct inode *inode;
- if (!events_ei)
- return;
+ inode = tracefs_get_inode(dentry->d_sb);
+ if (!inode)
+ return NULL;
- inode->i_mode = mode;
- inode->i_uid = events_ei->attr.uid;
- inode->i_gid = events_ei->attr.gid;
+ ti = get_tracefs(inode);
+ ti->private = ei;
+ ti->flags |= TRACEFS_EVENT_INODE;
- if (!attr)
- return;
+ /* Find the top dentry that holds the "events" directory */
+ do {
+ dentry = dentry->d_parent;
+ /* Directories always have d_fsdata */
+ pei = dentry->d_fsdata;
+ } while (!pei->is_events);
- if (attr->mode & EVENTFS_SAVE_MODE)
- inode->i_mode = attr->mode & EVENTFS_MODE_MASK;
+ rei = get_root_inode(pei);
- if (attr->mode & EVENTFS_SAVE_UID)
- inode->i_uid = attr->uid;
+ update_inode_attr(inode, mode, attr, rei);
- if (attr->mode & EVENTFS_SAVE_GID)
- inode->i_gid = attr->gid;
+ return inode;
}
/**
@@ -401,7 +370,6 @@ static struct dentry *lookup_file(struct eventfs_inode *parent_ei,
void *data,
const struct file_operations *fop)
{
- struct tracefs_inode *ti;
struct inode *inode;
if (!(mode & S_IFMT))
@@ -410,13 +378,11 @@ static struct dentry *lookup_file(struct eventfs_inode *parent_ei,
if (WARN_ON_ONCE(!S_ISREG(mode)))
return ERR_PTR(-EIO);
- inode = tracefs_get_inode(dentry->d_sb);
+ /* Only directories have ti->private set to an ei, not files */
+ inode = eventfs_get_inode(dentry, attr, mode, NULL);
if (unlikely(!inode))
return ERR_PTR(-ENOMEM);
- /* If the user updated the directory's attributes, use them */
- update_inode_attr(dentry, inode, attr, mode);
-
inode->i_op = &eventfs_file_inode_operations;
inode->i_fop = fop;
inode->i_private = data;
@@ -424,9 +390,6 @@ static struct dentry *lookup_file(struct eventfs_inode *parent_ei,
/* All files will have the same inode number */
inode->i_ino = EVENTFS_FILE_INODE_INO;
- ti = get_tracefs(inode);
- ti->flags |= TRACEFS_EVENT_INODE;
-
// Files have their parent's ei as their fsdata
dentry->d_fsdata = get_ei(parent_ei);
@@ -446,28 +409,19 @@ static struct dentry *lookup_file(struct eventfs_inode *parent_ei,
static struct dentry *lookup_dir_entry(struct dentry *dentry,
struct eventfs_inode *pei, struct eventfs_inode *ei)
{
- struct tracefs_inode *ti;
struct inode *inode;
+ umode_t mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
- inode = tracefs_get_inode(dentry->d_sb);
+ inode = eventfs_get_inode(dentry, &ei->attr, mode, ei);
if (unlikely(!inode))
return ERR_PTR(-ENOMEM);
- /* If the user updated the directory's attributes, use them */
- update_inode_attr(dentry, inode, &ei->attr,
- S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO);
-
inode->i_op = &eventfs_dir_inode_operations;
inode->i_fop = &eventfs_file_operations;
/* All directories will have the same inode number */
inode->i_ino = eventfs_dir_ino(ei);
- ti = get_tracefs(inode);
- ti->flags |= TRACEFS_EVENT_INODE;
- /* Only directories have ti->private set to an ei, not files */
- ti->private = ei;
-
dentry->d_fsdata = get_ei(ei);
d_add(dentry, inode);
@@ -828,7 +782,6 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry
// Note: we have a ref to the dentry from tracefs_start_creating()
rei = get_root_inode(ei);
rei->events_dir = dentry;
- rei->parent_inode = d_inode(dentry->d_sb->s_root);
ei->entries = entries;
ei->nr_entries = size;
@@ -838,14 +791,12 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry
uid = d_inode(dentry->d_parent)->i_uid;
gid = d_inode(dentry->d_parent)->i_gid;
- ei->attr.uid = uid;
- ei->attr.gid = gid;
-
/*
- * When the "events" directory is created, it takes on the
- * permissions of its parent. But can be reset on remount.
+ * The ei->attr will be used as the default values for the
+ * files beneath this directory.
*/
- ei->attr.mode |= EVENTFS_SAVE_UID | EVENTFS_SAVE_GID;
+ ei->attr.uid = uid;
+ ei->attr.gid = gid;
INIT_LIST_HEAD(&ei->children);
INIT_LIST_HEAD(&ei->list);