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-rw-r--r--Documentation/filesystems/vfs.txt22
1 files changed, 13 insertions, 9 deletions
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index a47cc819f37b..f023609fa718 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -3,7 +3,7 @@
3 3
4 Original author: Richard Gooch <rgooch@atnf.csiro.au> 4 Original author: Richard Gooch <rgooch@atnf.csiro.au>
5 5
6 Last updated on October 28, 2005 6 Last updated on June 24, 2007.
7 7
8 Copyright (C) 1999 Richard Gooch 8 Copyright (C) 1999 Richard Gooch
9 Copyright (C) 2005 Pekka Enberg 9 Copyright (C) 2005 Pekka Enberg
@@ -107,7 +107,7 @@ file /proc/filesystems.
107struct file_system_type 107struct file_system_type
108----------------------- 108-----------------------
109 109
110This describes the filesystem. As of kernel 2.6.13, the following 110This describes the filesystem. As of kernel 2.6.22, the following
111members are defined: 111members are defined:
112 112
113struct file_system_type { 113struct file_system_type {
@@ -119,6 +119,8 @@ struct file_system_type {
119 struct module *owner; 119 struct module *owner;
120 struct file_system_type * next; 120 struct file_system_type * next;
121 struct list_head fs_supers; 121 struct list_head fs_supers;
122 struct lock_class_key s_lock_key;
123 struct lock_class_key s_umount_key;
122}; 124};
123 125
124 name: the name of the filesystem type, such as "ext2", "iso9660", 126 name: the name of the filesystem type, such as "ext2", "iso9660",
@@ -137,11 +139,12 @@ struct file_system_type {
137 139
138 next: for internal VFS use: you should initialize this to NULL 140 next: for internal VFS use: you should initialize this to NULL
139 141
142 s_lock_key, s_umount_key: lockdep-specific
143
140The get_sb() method has the following arguments: 144The get_sb() method has the following arguments:
141 145
142 struct super_block *sb: the superblock structure. This is partially 146 struct file_system_type *fs_type: decribes the filesystem, partly initialized
143 initialized by the VFS and the rest must be initialized by the 147 by the specific filesystem code
144 get_sb() method
145 148
146 int flags: mount flags 149 int flags: mount flags
147 150
@@ -150,12 +153,13 @@ The get_sb() method has the following arguments:
150 void *data: arbitrary mount options, usually comes as an ASCII 153 void *data: arbitrary mount options, usually comes as an ASCII
151 string 154 string
152 155
153 int silent: whether or not to be silent on error 156 struct vfsmount *mnt: a vfs-internal representation of a mount point
154 157
155The get_sb() method must determine if the block device specified 158The get_sb() method must determine if the block device specified
156in the superblock contains a filesystem of the type the method 159in the dev_name and fs_type contains a filesystem of the type the method
157supports. On success the method returns the superblock pointer, on 160supports. If it succeeds in opening the named block device, it initializes a
158failure it returns NULL. 161struct super_block descriptor for the filesystem contained by the block device.
162On failure it returns an error.
159 163
160The most interesting member of the superblock structure that the 164The most interesting member of the superblock structure that the
161get_sb() method fills in is the "s_op" field. This is a pointer to 165get_sb() method fills in is the "s_op" field. This is a pointer to