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-rw-r--r--fs/tracefs/inode.c278
1 files changed, 126 insertions, 152 deletions
diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
index 0292c6a2be..d65ffad4c3 100644
--- a/fs/tracefs/inode.c
+++ b/fs/tracefs/inode.c
@@ -38,8 +38,6 @@ static struct inode *tracefs_alloc_inode(struct super_block *sb)
if (!ti)
return NULL;
- ti->flags = 0;
-
return &ti->vfs_inode;
}
@@ -91,6 +89,7 @@ static int tracefs_syscall_mkdir(struct mnt_idmap *idmap,
struct inode *inode, struct dentry *dentry,
umode_t mode)
{
+ struct tracefs_inode *ti;
char *name;
int ret;
@@ -99,6 +98,15 @@ static int tracefs_syscall_mkdir(struct mnt_idmap *idmap,
return -ENOMEM;
/*
+ * This is a new directory that does not take the default of
+ * the rootfs. It becomes the default permissions for all the
+ * files and directories underneath it.
+ */
+ ti = get_tracefs(inode);
+ ti->flags |= TRACEFS_INSTANCE_INODE;
+ ti->private = inode;
+
+ /*
* The mkdir call can call the generic functions that create
* the files within the tracefs system. It is up to the individual
* mkdir routine to handle races.
@@ -141,10 +149,76 @@ static int tracefs_syscall_rmdir(struct inode *inode, struct dentry *dentry)
return ret;
}
-static const struct inode_operations tracefs_dir_inode_operations = {
+static void set_tracefs_inode_owner(struct inode *inode)
+{
+ struct tracefs_inode *ti = get_tracefs(inode);
+ struct inode *root_inode = ti->private;
+
+ /*
+ * If this inode has never been referenced, then update
+ * the permissions to the superblock.
+ */
+ if (!(ti->flags & TRACEFS_UID_PERM_SET))
+ inode->i_uid = root_inode->i_uid;
+
+ if (!(ti->flags & TRACEFS_GID_PERM_SET))
+ inode->i_gid = root_inode->i_gid;
+}
+
+static int tracefs_permission(struct mnt_idmap *idmap,
+ struct inode *inode, int mask)
+{
+ set_tracefs_inode_owner(inode);
+ return generic_permission(idmap, inode, mask);
+}
+
+static int tracefs_getattr(struct mnt_idmap *idmap,
+ const struct path *path, struct kstat *stat,
+ u32 request_mask, unsigned int flags)
+{
+ struct inode *inode = d_backing_inode(path->dentry);
+
+ set_tracefs_inode_owner(inode);
+ generic_fillattr(idmap, request_mask, inode, stat);
+ return 0;
+}
+
+static int tracefs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
+ struct iattr *attr)
+{
+ unsigned int ia_valid = attr->ia_valid;
+ struct inode *inode = d_inode(dentry);
+ struct tracefs_inode *ti = get_tracefs(inode);
+
+ if (ia_valid & ATTR_UID)
+ ti->flags |= TRACEFS_UID_PERM_SET;
+
+ if (ia_valid & ATTR_GID)
+ ti->flags |= TRACEFS_GID_PERM_SET;
+
+ return simple_setattr(idmap, dentry, attr);
+}
+
+static const struct inode_operations tracefs_instance_dir_inode_operations = {
.lookup = simple_lookup,
.mkdir = tracefs_syscall_mkdir,
.rmdir = tracefs_syscall_rmdir,
+ .permission = tracefs_permission,
+ .getattr = tracefs_getattr,
+ .setattr = tracefs_setattr,
+};
+
+static const struct inode_operations tracefs_dir_inode_operations = {
+ .lookup = simple_lookup,
+ .permission = tracefs_permission,
+ .getattr = tracefs_getattr,
+ .setattr = tracefs_setattr,
+};
+
+static const struct inode_operations tracefs_file_inode_operations = {
+ .permission = tracefs_permission,
+ .getattr = tracefs_getattr,
+ .setattr = tracefs_setattr,
};
struct inode *tracefs_get_inode(struct super_block *sb)
@@ -152,7 +226,7 @@ struct inode *tracefs_get_inode(struct super_block *sb)
struct inode *inode = new_inode(sb);
if (inode) {
inode->i_ino = get_next_ino();
- inode->i_atime = inode->i_mtime = inode_set_ctime_current(inode);
+ simple_inode_init_ts(inode);
}
return inode;
}
@@ -183,77 +257,6 @@ struct tracefs_fs_info {
struct tracefs_mount_opts mount_opts;
};
-static void change_gid(struct dentry *dentry, kgid_t gid)
-{
- if (!dentry->d_inode)
- return;
- dentry->d_inode->i_gid = gid;
-}
-
-/*
- * Taken from d_walk, but without he need for handling renames.
- * Nothing can be renamed while walking the list, as tracefs
- * does not support renames. This is only called when mounting
- * or remounting the file system, to set all the files to
- * the given gid.
- */
-static void set_gid(struct dentry *parent, kgid_t gid)
-{
- struct dentry *this_parent;
- struct list_head *next;
-
- this_parent = parent;
- spin_lock(&this_parent->d_lock);
-
- change_gid(this_parent, gid);
-repeat:
- next = this_parent->d_subdirs.next;
-resume:
- while (next != &this_parent->d_subdirs) {
- struct list_head *tmp = next;
- struct dentry *dentry = list_entry(tmp, struct dentry, d_child);
- next = tmp->next;
-
- spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
-
- change_gid(dentry, gid);
-
- if (!list_empty(&dentry->d_subdirs)) {
- spin_unlock(&this_parent->d_lock);
- spin_release(&dentry->d_lock.dep_map, _RET_IP_);
- this_parent = dentry;
- spin_acquire(&this_parent->d_lock.dep_map, 0, 1, _RET_IP_);
- goto repeat;
- }
- spin_unlock(&dentry->d_lock);
- }
- /*
- * All done at this level ... ascend and resume the search.
- */
- rcu_read_lock();
-ascend:
- if (this_parent != parent) {
- struct dentry *child = this_parent;
- this_parent = child->d_parent;
-
- spin_unlock(&child->d_lock);
- spin_lock(&this_parent->d_lock);
-
- /* go into the first sibling still alive */
- do {
- next = child->d_child.next;
- if (next == &this_parent->d_subdirs)
- goto ascend;
- child = list_entry(next, struct dentry, d_child);
- } while (unlikely(child->d_flags & DCACHE_DENTRY_KILLED));
- rcu_read_unlock();
- goto resume;
- }
- rcu_read_unlock();
- spin_unlock(&this_parent->d_lock);
- return;
-}
-
static int tracefs_parse_options(char *data, struct tracefs_mount_opts *opts)
{
substring_t args[MAX_OPT_ARGS];
@@ -326,10 +329,8 @@ static int tracefs_apply_options(struct super_block *sb, bool remount)
if (!remount || opts->opts & BIT(Opt_uid))
inode->i_uid = opts->uid;
- if (!remount || opts->opts & BIT(Opt_gid)) {
- /* Set all the group ids to the mount option */
- set_gid(sb->s_root, opts->gid);
- }
+ if (!remount || opts->opts & BIT(Opt_gid))
+ inode->i_gid = opts->gid;
return 0;
}
@@ -376,21 +377,30 @@ static const struct super_operations tracefs_super_operations = {
.show_options = tracefs_show_options,
};
-static void tracefs_dentry_iput(struct dentry *dentry, struct inode *inode)
+/*
+ * It would be cleaner if eventfs had its own dentry ops.
+ *
+ * Note that d_revalidate is called potentially under RCU,
+ * so it can't take the eventfs mutex etc. It's fine - if
+ * we open a file just as it's marked dead, things will
+ * still work just fine, and just see the old stale case.
+ */
+static void tracefs_d_release(struct dentry *dentry)
{
- struct tracefs_inode *ti;
+ if (dentry->d_fsdata)
+ eventfs_d_release(dentry);
+}
- if (!dentry || !inode)
- return;
+static int tracefs_d_revalidate(struct dentry *dentry, unsigned int flags)
+{
+ struct eventfs_inode *ei = dentry->d_fsdata;
- ti = get_tracefs(inode);
- if (ti && ti->flags & TRACEFS_EVENT_INODE)
- eventfs_set_ef_status_free(ti, dentry);
- iput(inode);
+ return !(ei && ei->is_freed);
}
static const struct dentry_operations tracefs_dentry_operations = {
- .d_iput = tracefs_dentry_iput,
+ .d_revalidate = tracefs_d_revalidate,
+ .d_release = tracefs_d_release,
};
static int trace_fill_super(struct super_block *sb, void *data, int silent)
@@ -494,73 +504,24 @@ struct dentry *tracefs_end_creating(struct dentry *dentry)
return dentry;
}
-/**
- * eventfs_start_creating - start the process of creating a dentry
- * @name: Name of the file created for the dentry
- * @parent: The parent dentry where this dentry will be created
- *
- * This is a simple helper function for the dynamically created eventfs
- * files. When the directory of the eventfs files are accessed, their
- * dentries are created on the fly. This function is used to start that
- * process.
- */
-struct dentry *eventfs_start_creating(const char *name, struct dentry *parent)
+/* Find the inode that this will use for default */
+static struct inode *instance_inode(struct dentry *parent, struct inode *inode)
{
- struct dentry *dentry;
- int error;
-
- /* Must always have a parent. */
- if (WARN_ON_ONCE(!parent))
- return ERR_PTR(-EINVAL);
-
- error = simple_pin_fs(&trace_fs_type, &tracefs_mount,
- &tracefs_mount_count);
- if (error)
- return ERR_PTR(error);
+ struct tracefs_inode *ti;
- if (unlikely(IS_DEADDIR(parent->d_inode)))
- dentry = ERR_PTR(-ENOENT);
- else
- dentry = lookup_one_len(name, parent, strlen(name));
+ /* If parent is NULL then use root inode */
+ if (!parent)
+ return d_inode(inode->i_sb->s_root);
- if (!IS_ERR(dentry) && dentry->d_inode) {
- dput(dentry);
- dentry = ERR_PTR(-EEXIST);
+ /* Find the inode that is flagged as an instance or the root inode */
+ while (!IS_ROOT(parent)) {
+ ti = get_tracefs(d_inode(parent));
+ if (ti->flags & TRACEFS_INSTANCE_INODE)
+ break;
+ parent = parent->d_parent;
}
- if (IS_ERR(dentry))
- simple_release_fs(&tracefs_mount, &tracefs_mount_count);
-
- return dentry;
-}
-
-/**
- * eventfs_failed_creating - clean up a failed eventfs dentry creation
- * @dentry: The dentry to clean up
- *
- * If after calling eventfs_start_creating(), a failure is detected, the
- * resources created by eventfs_start_creating() needs to be cleaned up. In
- * that case, this function should be called to perform that clean up.
- */
-struct dentry *eventfs_failed_creating(struct dentry *dentry)
-{
- dput(dentry);
- simple_release_fs(&tracefs_mount, &tracefs_mount_count);
- return NULL;
-}
-
-/**
- * eventfs_end_creating - Finish the process of creating a eventfs dentry
- * @dentry: The dentry that has successfully been created.
- *
- * This function is currently just a place holder to match
- * eventfs_start_creating(). In case any synchronization needs to be added,
- * this function will be used to implement that without having to modify
- * the callers of eventfs_start_creating().
- */
-struct dentry *eventfs_end_creating(struct dentry *dentry)
-{
- return dentry;
+ return d_inode(parent);
}
/**
@@ -593,6 +554,7 @@ struct dentry *tracefs_create_file(const char *name, umode_t mode,
struct dentry *parent, void *data,
const struct file_operations *fops)
{
+ struct tracefs_inode *ti;
struct dentry *dentry;
struct inode *inode;
@@ -611,7 +573,11 @@ struct dentry *tracefs_create_file(const char *name, umode_t mode,
if (unlikely(!inode))
return tracefs_failed_creating(dentry);
+ ti = get_tracefs(inode);
+ ti->private = instance_inode(parent, inode);
+
inode->i_mode = mode;
+ inode->i_op = &tracefs_file_inode_operations;
inode->i_fop = fops ? fops : &tracefs_file_operations;
inode->i_private = data;
inode->i_uid = d_inode(dentry->d_parent)->i_uid;
@@ -624,6 +590,7 @@ struct dentry *tracefs_create_file(const char *name, umode_t mode,
static struct dentry *__create_dir(const char *name, struct dentry *parent,
const struct inode_operations *ops)
{
+ struct tracefs_inode *ti;
struct dentry *dentry = tracefs_start_creating(name, parent);
struct inode *inode;
@@ -641,6 +608,9 @@ static struct dentry *__create_dir(const char *name, struct dentry *parent,
inode->i_uid = d_inode(dentry->d_parent)->i_uid;
inode->i_gid = d_inode(dentry->d_parent)->i_gid;
+ ti = get_tracefs(inode);
+ ti->private = instance_inode(parent, inode);
+
/* directory inodes start off with i_nlink == 2 (for "." entry) */
inc_nlink(inode);
d_instantiate(dentry, inode);
@@ -671,7 +641,7 @@ struct dentry *tracefs_create_dir(const char *name, struct dentry *parent)
if (security_locked_down(LOCKDOWN_TRACEFS))
return NULL;
- return __create_dir(name, parent, &simple_dir_inode_operations);
+ return __create_dir(name, parent, &tracefs_dir_inode_operations);
}
/**
@@ -702,7 +672,7 @@ __init struct dentry *tracefs_create_instance_dir(const char *name,
if (WARN_ON(tracefs_ops.mkdir || tracefs_ops.rmdir))
return NULL;
- dentry = __create_dir(name, parent, &tracefs_dir_inode_operations);
+ dentry = __create_dir(name, parent, &tracefs_instance_dir_inode_operations);
if (!dentry)
return NULL;
@@ -747,7 +717,11 @@ static void init_once(void *foo)
{
struct tracefs_inode *ti = (struct tracefs_inode *) foo;
+ /* inode_init_once() calls memset() on the vfs_inode portion */
inode_init_once(&ti->vfs_inode);
+
+ /* Zero out the rest */
+ memset_after(ti, 0, vfs_inode);
}
static int __init tracefs_init(void)