Ocfs2 devel - Dec 2009 - ocfs2: add extent block stealing for ocfs2 v1

Hi, Joel,

The attached patch is the first version about extent stealing. Please 
feel free to correct me about the codes or function name or comments.

thanks,
tiger
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http://oss.oracle.com/pipermail/ocfs2-devel/attachments/20091214/aa26e168/attachment.pl

Hi Tiger,

@@ -731,36 +715,39 @@ int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
 		goto bail;
 	}
 
-	(*ac)->ac_bits_wanted = 1;
-	(*ac)->ac_which = OCFS2_AC_USE_INODE;
-
+	(*ac)->ac_bits_wanted = blocks;
 	(*ac)->ac_group_search = ocfs2_block_group_search;
+	if (type == INODE_ALLOC_SYSTEM_INODE)
+		(*ac)->ac_which = OCFS2_AC_USE_INODE;
+	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
+		(*ac)->ac_which = OCFS2_AC_USE_META;
 
 	/*
 	 * stat(2) can't handle i_ino > 32bits, so we tell the
 	 * lower levels not to allocate us a block group past that
 	 * limit.  The 'inode64' mount option avoids this behavior.
 	 */
-	if (!(osb->s_mount_opt & OCFS2_MOUNT_INODE64))
+	if (type == INODE_ALLOC_SYSTEM_INODE &&
+	    !(osb->s_mount_opt & OCFS2_MOUNT_INODE64))
 		(*ac)->ac_max_block = (u32)~0U;
 
 	/*
-	 * slot is set when we successfully steal inode from other nodes.
-	 * It is reset in 3 places:
+	 * slot is set when we successfully steal inode/extent
+	 * from other nodes. It is reset in 3 places:
 	 * 1. when we flush the truncate log
 	 * 2. when we complete local alloc recovery.
 	 * 3. when we successfully allocate from our own slot.
-	 * After it is set, we will go on stealing inodes until we find the
+	 * After it is set, we will go on stealing resource until we find the
 	 * need to check our slots to see whether there is some space for us.
 	 */
 	if (slot != OCFS2_INVALID_SLOT &&
-	    atomic_read(&osb->s_num_inodes_stolen) <
OCFS2_MAX_INODES_TO_STEAL)
-		goto inode_steal;
+	    ocfs2_could_steal_resource(osb, type))
+		goto resource_steal;
 
-	atomic_set(&osb->s_num_inodes_stolen, 0);
+	ATOMIC_ZERO_RESOURCE_NUMBER(type);
 	alloc_group = osb->osb_inode_alloc_group;
here, you use the alloc_group which is only used in inode alloc and reset it
after the reservation succeed. I am afraid extent alloc shouldn't use and
change it?

 	status = ocfs2_reserve_suballoc_bits(osb, *ac,
-					     INODE_ALLOC_SYSTEM_INODE,
+					     type,
 					     osb->slot_num,
 					     &alloc_group,
 					     ALLOC_NEW_GROUP |


    I am also curious about one thing. Have you written the test script 
for it to see whether it works?
You can take ocfs2-tests/programs/inode_stealing/inode_stealing.sh for 
reference.

Regards,
Tao

Jun Yang wrote:
> Hi, Joel,
>
> The attached patch is the first version about extent stealing. Please 
> feel free to correct me about the codes or function name or comments.
>
> thanks,
> tiger
> ------------------------------------------------------------------------
>
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