From 85bf9a0ee2dd3bf6e506e531f4630fd50ecf1bfe Mon Sep 17 00:00:00 2001 From: Alexander Mikhalitsyn Date: Mon, 13 Mar 2023 14:07:17 +0100 Subject: [PATCH] docs: filesystems: vfs: actualize struct file_system_type description Added descriptions for: - fscontext API ('init_fs_context' method, 'parameters' field) - 'fs_supers' field Cc: Eric Biggers Cc: Miklos Szeredi Cc: Al Viro Cc: Christian Brauner Cc: linux-fsdevel@vger.kernel.org Cc: linux-doc@vger.kernel.org Signed-off-by: Alexander Mikhalitsyn Reviewed-by: Christian Brauner Link: https://lore.kernel.org/r/20230313130718.253708-2-aleksandr.mikhalitsyn@canonical.com Signed-off-by: Jonathan Corbet --- Documentation/filesystems/vfs.rst | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-) diff --git a/Documentation/filesystems/vfs.rst b/Documentation/filesystems/vfs.rst index f3b344f..120c428 100644 --- a/Documentation/filesystems/vfs.rst +++ b/Documentation/filesystems/vfs.rst @@ -107,7 +107,7 @@ file /proc/filesystems. struct file_system_type ----------------------- -This describes the filesystem. As of kernel 2.6.39, the following +This describes the filesystem. The following members are defined: .. code-block:: c @@ -115,14 +115,24 @@ members are defined: struct file_system_type { const char *name; int fs_flags; + int (*init_fs_context)(struct fs_context *); + const struct fs_parameter_spec *parameters; struct dentry *(*mount) (struct file_system_type *, int, - const char *, void *); + const char *, void *); void (*kill_sb) (struct super_block *); struct module *owner; struct file_system_type * next; - struct list_head fs_supers; + struct hlist_head fs_supers; + struct lock_class_key s_lock_key; struct lock_class_key s_umount_key; + struct lock_class_key s_vfs_rename_key; + struct lock_class_key s_writers_key[SB_FREEZE_LEVELS]; + + struct lock_class_key i_lock_key; + struct lock_class_key i_mutex_key; + struct lock_class_key invalidate_lock_key; + struct lock_class_key i_mutex_dir_key; }; ``name`` @@ -132,6 +142,15 @@ members are defined: ``fs_flags`` various flags (i.e. FS_REQUIRES_DEV, FS_NO_DCACHE, etc.) +``init_fs_context`` + Initializes 'struct fs_context' ->ops and ->fs_private fields with + filesystem-specific data. + +``parameters`` + Pointer to the array of filesystem parameters descriptors + 'struct fs_parameter_spec'. + More info in Documentation/filesystems/mount_api.rst. + ``mount`` the method to call when a new instance of this filesystem should be mounted @@ -148,7 +167,11 @@ members are defined: ``next`` for internal VFS use: you should initialize this to NULL - s_lock_key, s_umount_key: lockdep-specific +``fs_supers`` + for internal VFS use: hlist of filesystem instances (superblocks) + + s_lock_key, s_umount_key, s_vfs_rename_key, s_writers_key, + i_lock_key, i_mutex_key, invalidate_lock_key, i_mutex_dir_key: lockdep-specific The mount() method has the following arguments: -- 2.7.4