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authorAmir Goldstein <amir73il@gmail.com>2011-03-20 21:13:43 -0400
committerTheodore Ts'o <tytso@mit.edu>2011-03-20 21:13:43 -0400
commit93737456d68ddcb86232f669b83da673dd12e351 (patch)
tree564feaa33d36c5e06ad200c5225382ff0afd5249 /include/linux/jbd2.h
parentc2cc7028e41c76e44b6e247c4b495c7523b23c87 (diff)
jbd2: add COW fields to struct jbd2_journal_handle
Add fields needed for the copy-on-write ext4 development work. The h_cowing flag is used by ext4 snapshots code to mark the task in COWING state. The h_XXX_credits fields are used to track buffer credits usage (accounted by COW and non-COW operations). The h_cow_XXX fields are used as per task debugging counters. Merging this commit into mainline will allow users to test ext4 snapshots as a standalone module, without the need to patch and install a development kernel. Signed-off-by: Amir Goldstein <amir73il@users.sf.net> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'include/linux/jbd2.h')
-rw-r--r--include/linux/jbd2.h28
1 files changed, 25 insertions, 3 deletions
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 27e79c27ba08..a32dcaec04e1 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -432,13 +432,35 @@ struct jbd2_journal_handle
int h_err;
/* Flags [no locking] */
- unsigned int h_sync: 1; /* sync-on-close */
- unsigned int h_jdata: 1; /* force data journaling */
- unsigned int h_aborted: 1; /* fatal error on handle */
+ unsigned int h_sync:1; /* sync-on-close */
+ unsigned int h_jdata:1; /* force data journaling */
+ unsigned int h_aborted:1; /* fatal error on handle */
+ unsigned int h_cowing:1; /* COWing block to snapshot */
+
+ /* Number of buffers requested by user:
+ * (before adding the COW credits factor) */
+ unsigned int h_base_credits:14;
+
+ /* Number of buffers the user is allowed to dirty:
+ * (counts only buffers dirtied when !h_cowing) */
+ unsigned int h_user_credits:14;
+
#ifdef CONFIG_DEBUG_LOCK_ALLOC
struct lockdep_map h_lockdep_map;
#endif
+
+#ifdef CONFIG_JBD2_DEBUG
+ /* COW debugging counters: */
+ unsigned int h_cow_moved; /* blocks moved to snapshot */
+ unsigned int h_cow_copied; /* blocks copied to snapshot */
+ unsigned int h_cow_ok_jh; /* blocks already COWed during current
+ transaction */
+ unsigned int h_cow_ok_bitmap; /* blocks not set in COW bitmap */
+ unsigned int h_cow_ok_mapped;/* blocks already mapped in snapshot */
+ unsigned int h_cow_bitmaps; /* COW bitmaps created */
+ unsigned int h_cow_excluded; /* blocks set in exclude bitmap */
+#endif
};