hwmon: (lm85) Convert to a new-style i2c driver

[linux-2.6-omap-h63xx.git] / Documentation / filesystems / porting

diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting
index dac45c92d872b977312372210243ffa318ad08cb..92b888d540a667c17a630e8dc005cd672c726058 100644 (file)
--- a/Documentation/filesystems/porting
+++ b/Documentation/filesystems/porting
@@ -1,6 +1,6 @@
 Changes since 2.5.0:
 
 Changes since 2.5.0:
 

---- 
+---

 [recommended]
 
 New helpers: sb_bread(), sb_getblk(), sb_find_get_block(), set_bh(),
 [recommended]
 
 New helpers: sb_bread(), sb_getblk(), sb_find_get_block(), set_bh(),


@@ -10,7 +10,7 @@ Use them.
 
 (sb_find_get_block() replaces 2.4's get_hash_table())
 
 
 (sb_find_get_block() replaces 2.4's get_hash_table())
 

---- 
+---

 [recommended]
 
 New methods: ->alloc_inode() and ->destroy_inode().
 [recommended]
 
 New methods: ->alloc_inode() and ->destroy_inode().


@@ -28,14 +28,14 @@ Declare
 
 Use FOO_I(inode) instead of &inode->u.foo_inode_i;
 
 
 Use FOO_I(inode) instead of &inode->u.foo_inode_i;
 

-Add foo_alloc_inode() and foo_destory_inode() - the former should allocate
+Add foo_alloc_inode() and foo_destroy_inode() - the former should allocate

 foo_inode_info and return the address of ->vfs_inode, the latter should free
 FOO_I(inode) (see in-tree filesystems for examples).
 
 Make them ->alloc_inode and ->destroy_inode in your super_operations.
 
 foo_inode_info and return the address of ->vfs_inode, the latter should free
 FOO_I(inode) (see in-tree filesystems for examples).
 
 Make them ->alloc_inode and ->destroy_inode in your super_operations.
 

-Keep in mind that now you need explicit initialization of private data -
-typically in ->read_inode() and after getting an inode from new_inode().
+Keep in mind that now you need explicit initialization of private data
+typically between calling iget_locked() and unlocking the inode.

 
 At some point that will become mandatory.
 
 
 At some point that will become mandatory.
 


@@ -173,10 +173,10 @@ should be a non-blocking function that initializes those parts of a
 newly created inode to allow the test function to succeed. 'data' is
 passed as an opaque value to both test and set functions.
 
 newly created inode to allow the test function to succeed. 'data' is
 passed as an opaque value to both test and set functions.
 

-When the inode has been created by iget5_locked(), it will be returned with
-the I_NEW flag set and will still be locked. read_inode has not been
-called so the file system still has to finalize the initialization. Once
-the inode is initialized it must be unlocked by calling unlock_new_inode().
+When the inode has been created by iget5_locked(), it will be returned with the
+I_NEW flag set and will still be locked.  The filesystem then needs to finalize
+the initialization. Once the inode is initialized it must be unlocked by
+calling unlock_new_inode().

 
 The filesystem is responsible for setting (and possibly testing) i_ino
 when appropriate. There is also a simpler iget_locked function that
 
 The filesystem is responsible for setting (and possibly testing) i_ino
 when appropriate. There is also a simpler iget_locked function that


@@ -184,11 +184,19 @@ just takes the superblock and inode number as arguments and does the
 test and set for you.
 
 e.g.
 test and set for you.
 
 e.g.

-       inode = iget_locked(sb, ino);
-       if (inode->i_state & I_NEW) {
-               read_inode_from_disk(inode);
-               unlock_new_inode(inode);
-       }
+       inode = iget_locked(sb, ino);
+       if (inode->i_state & I_NEW) {
+               err = read_inode_from_disk(inode);
+               if (err < 0) {
+                       iget_failed(inode);
+                       return err;
+               }
+               unlock_new_inode(inode);
+       }
+
+Note that if the process of setting up a new inode fails, then iget_failed()
+should be called on the inode to render it dead, and an appropriate error
+should be passed back to the caller.

 
 ---
 [recommended]
 
 ---
 [recommended]