Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid

[cascardo/linux.git] / Documentation / filesystems / vfs.txt

diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index 9ace359..d619c8d 100644 (file)
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -323,6 +323,35 @@ Whoever sets up the inode is responsible for filling in the "i_op" field. This
 is a pointer to a "struct inode_operations" which describes the methods that
 can be performed on individual inodes.
 
+struct xattr_handlers
+---------------------
+
+On filesystems that support extended attributes (xattrs), the s_xattr
+superblock field points to a NULL-terminated array of xattr handlers.  Extended
+attributes are name:value pairs.
+
+  name: Indicates that the handler matches attributes with the specified name
+       (such as "system.posix_acl_access"); the prefix field must be NULL.
+
+  prefix: Indicates that the handler matches all attributes with the specified
+       name prefix (such as "user."); the name field must be NULL.
+
+  list: Determine if attributes matching this xattr handler should be listed
+       for a particular dentry.  Used by some listxattr implementations like
+       generic_listxattr.
+
+  get: Called by the VFS to get the value of a particular extended attribute.
+       This method is called by the getxattr(2) system call.
+
+  set: Called by the VFS to set the value of a particular extended attribute.
+       When the new value is NULL, called to remove a particular extended
+       attribute.  This method is called by the the setxattr(2) and
+       removexattr(2) system calls.
+
+When none of the xattr handlers of a filesystem match the specified attribute
+name or when a filesystem doesn't support extended attributes, the various
+*xattr(2) system calls return -EOPNOTSUPP.
+
 
 The Inode Object
 ================
@@ -346,8 +375,6 @@ struct inode_operations {
        int (*rmdir) (struct inode *,struct dentry *);
        int (*mknod) (struct inode *,struct dentry *,umode_t,dev_t);
        int (*rename) (struct inode *, struct dentry *,
-                       struct inode *, struct dentry *);
-       int (*rename2) (struct inode *, struct dentry *,
                        struct inode *, struct dentry *, unsigned int);
        int (*readlink) (struct dentry *, char __user *,int);
        const char *(*get_link) (struct dentry *, struct inode *,
@@ -356,10 +383,7 @@ struct inode_operations {
        int (*get_acl)(struct inode *, int);
        int (*setattr) (struct dentry *, struct iattr *);
        int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *);
-       int (*setxattr) (struct dentry *, const char *,const void *,size_t,int);
-       ssize_t (*getxattr) (struct dentry *, const char *, void *, size_t);
        ssize_t (*listxattr) (struct dentry *, char *, size_t);
-       int (*removexattr) (struct dentry *, const char *);
        void (*update_time)(struct inode *, struct timespec *, int);
        int (*atomic_open)(struct inode *, struct dentry *, struct file *,
                        unsigned open_flag, umode_t create_mode, int *opened);
@@ -416,11 +440,8 @@ otherwise noted.
   rename: called by the rename(2) system call to rename the object to
        have the parent and name given by the second inode and dentry.
 
-  rename2: this has an additional flags argument compared to rename.
-       If no flags are supported by the filesystem then this method
-       need not be implemented.  If some flags are supported then the
-       filesystem must return -EINVAL for any unsupported or unknown
-       flags.  Currently the following flags are implemented:
+       The filesystem must return -EINVAL for any unsupported or
+       unknown flags.  Currently the following flags are implemented:
        (1) RENAME_NOREPLACE: this flag indicates that if the target
        of the rename exists the rename should fail with -EEXIST
        instead of replacing the target.  The VFS already checks for
@@ -463,19 +484,8 @@ otherwise noted.
   getattr: called by the VFS to get attributes of a file. This method
        is called by stat(2) and related system calls.
 
-  setxattr: called by the VFS to set an extended attribute for a file.
-       Extended attribute is a name:value pair associated with an
-       inode. This method is called by setxattr(2) system call.
-
-  getxattr: called by the VFS to retrieve the value of an extended
-       attribute name. This method is called by getxattr(2) function
-       call.
-
   listxattr: called by the VFS to list all extended attributes for a
-       given file. This method is called by listxattr(2) system call.
-
-  removexattr: called by the VFS to remove an extended attribute from
-       a file. This method is called by removexattr(2) system call.
+       given file. This method is called by the listxattr(2) system call.
 
   update_time: called by the VFS to update a specific time or the i_version of
        an inode.  If this is not defined the VFS will update the inode itself
@@ -722,7 +732,7 @@ struct address_space_operations {
 
        The second case is when a request has been made to invalidate
         some or all pages in an address_space.  This can happen
-        through the fadvice(POSIX_FADV_DONTNEED) system call or by the
+        through the fadvise(POSIX_FADV_DONTNEED) system call or by the
         filesystem explicitly requesting it as nfs and 9fs do (when
         they believe the cache may be out of date with storage) by
         calling invalidate_inode_pages2().