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| author | Amir Goldstein <amir73il@gmail.com> | 2011-03-20 21:13:43 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2011-03-20 21:13:43 -0400 |
| commit | 93737456d68ddcb86232f669b83da673dd12e351 (patch) | |
| tree | 564feaa33d36c5e06ad200c5225382ff0afd5249 /include/linux/jbd2.h | |
| parent | c2cc7028e41c76e44b6e247c4b495c7523b23c87 (diff) | |
| download | lwn-93737456d68ddcb86232f669b83da673dd12e351.tar.gz lwn-93737456d68ddcb86232f669b83da673dd12e351.zip | |
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.h | 28 |
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 }; |